1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Security-Enhanced Linux (SELinux) security module
4 *
5 * This file contains the SELinux hook function implementations.
6 *
7 * Authors: Stephen Smalley, <stephen.smalley.work@gmail.com>
8 * Chris Vance, <cvance@nai.com>
9 * Wayne Salamon, <wsalamon@nai.com>
10 * James Morris <jmorris@redhat.com>
11 *
12 * Copyright (C) 2001,2002 Networks Associates Technology, Inc.
13 * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
14 * Eric Paris <eparis@redhat.com>
15 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
16 * <dgoeddel@trustedcs.com>
17 * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
18 * Paul Moore <paul@paul-moore.com>
19 * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
20 * Yuichi Nakamura <ynakam@hitachisoft.jp>
21 * Copyright (C) 2016 Mellanox Technologies
22 */
23
24 #include <linux/init.h>
25 #include <linux/kd.h>
26 #include <linux/kernel.h>
27 #include <linux/kernel_read_file.h>
28 #include <linux/errno.h>
29 #include <linux/sched/signal.h>
30 #include <linux/sched/task.h>
31 #include <linux/lsm_hooks.h>
32 #include <linux/xattr.h>
33 #include <linux/capability.h>
34 #include <linux/unistd.h>
35 #include <linux/mm.h>
36 #include <linux/mman.h>
37 #include <linux/slab.h>
38 #include <linux/pagemap.h>
39 #include <linux/proc_fs.h>
40 #include <linux/swap.h>
41 #include <linux/spinlock.h>
42 #include <linux/syscalls.h>
43 #include <linux/dcache.h>
44 #include <linux/file.h>
45 #include <linux/fdtable.h>
46 #include <linux/namei.h>
47 #include <linux/mount.h>
48 #include <linux/fs_context.h>
49 #include <linux/fs_parser.h>
50 #include <linux/netfilter_ipv4.h>
51 #include <linux/netfilter_ipv6.h>
52 #include <linux/tty.h>
53 #include <net/icmp.h>
54 #include <net/ip.h> /* for local_port_range[] */
55 #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
56 #include <net/inet_connection_sock.h>
57 #include <net/net_namespace.h>
58 #include <net/netlabel.h>
59 #include <linux/uaccess.h>
60 #include <asm/ioctls.h>
61 #include <linux/atomic.h>
62 #include <linux/bitops.h>
63 #include <linux/interrupt.h>
64 #include <linux/netdevice.h> /* for network interface checks */
65 #include <net/netlink.h>
66 #include <linux/tcp.h>
67 #include <linux/udp.h>
68 #include <linux/dccp.h>
69 #include <linux/sctp.h>
70 #include <net/sctp/structs.h>
71 #include <linux/quota.h>
72 #include <linux/un.h> /* for Unix socket types */
73 #include <net/af_unix.h> /* for Unix socket types */
74 #include <linux/parser.h>
75 #include <linux/nfs_mount.h>
76 #include <net/ipv6.h>
77 #include <linux/hugetlb.h>
78 #include <linux/personality.h>
79 #include <linux/audit.h>
80 #include <linux/string.h>
81 #include <linux/mutex.h>
82 #include <linux/posix-timers.h>
83 #include <linux/syslog.h>
84 #include <linux/user_namespace.h>
85 #include <linux/export.h>
86 #include <linux/msg.h>
87 #include <linux/shm.h>
88 #include <uapi/linux/shm.h>
89 #include <linux/bpf.h>
90 #include <linux/kernfs.h>
91 #include <linux/stringhash.h> /* for hashlen_string() */
92 #include <uapi/linux/mount.h>
93 #include <linux/fsnotify.h>
94 #include <linux/fanotify.h>
95 #include <linux/io_uring/cmd.h>
96 #include <uapi/linux/lsm.h>
97
98 #include "avc.h"
99 #include "objsec.h"
100 #include "netif.h"
101 #include "netnode.h"
102 #include "netport.h"
103 #include "ibpkey.h"
104 #include "xfrm.h"
105 #include "netlabel.h"
106 #include "audit.h"
107 #include "avc_ss.h"
108
109 #define SELINUX_INODE_INIT_XATTRS 1
110
111 struct selinux_state selinux_state;
112
113 /* SECMARK reference count */
114 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
115
116 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
117 static int selinux_enforcing_boot __initdata;
118
enforcing_setup(char * str)119 static int __init enforcing_setup(char *str)
120 {
121 unsigned long enforcing;
122 if (!kstrtoul(str, 0, &enforcing))
123 selinux_enforcing_boot = enforcing ? 1 : 0;
124 return 1;
125 }
126 __setup("enforcing=", enforcing_setup);
127 #else
128 #define selinux_enforcing_boot 1
129 #endif
130
131 int selinux_enabled_boot __initdata = 1;
132 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
selinux_enabled_setup(char * str)133 static int __init selinux_enabled_setup(char *str)
134 {
135 unsigned long enabled;
136 if (!kstrtoul(str, 0, &enabled))
137 selinux_enabled_boot = enabled ? 1 : 0;
138 return 1;
139 }
140 __setup("selinux=", selinux_enabled_setup);
141 #endif
142
checkreqprot_setup(char * str)143 static int __init checkreqprot_setup(char *str)
144 {
145 unsigned long checkreqprot;
146
147 if (!kstrtoul(str, 0, &checkreqprot)) {
148 if (checkreqprot)
149 pr_err("SELinux: checkreqprot set to 1 via kernel parameter. This is no longer supported.\n");
150 }
151 return 1;
152 }
153 __setup("checkreqprot=", checkreqprot_setup);
154
155 /**
156 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
157 *
158 * Description:
159 * This function checks the SECMARK reference counter to see if any SECMARK
160 * targets are currently configured, if the reference counter is greater than
161 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is
162 * enabled, false (0) if SECMARK is disabled. If the always_check_network
163 * policy capability is enabled, SECMARK is always considered enabled.
164 *
165 */
selinux_secmark_enabled(void)166 static int selinux_secmark_enabled(void)
167 {
168 return (selinux_policycap_alwaysnetwork() ||
169 atomic_read(&selinux_secmark_refcount));
170 }
171
172 /**
173 * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled
174 *
175 * Description:
176 * This function checks if NetLabel or labeled IPSEC is enabled. Returns true
177 * (1) if any are enabled or false (0) if neither are enabled. If the
178 * always_check_network policy capability is enabled, peer labeling
179 * is always considered enabled.
180 *
181 */
selinux_peerlbl_enabled(void)182 static int selinux_peerlbl_enabled(void)
183 {
184 return (selinux_policycap_alwaysnetwork() ||
185 netlbl_enabled() || selinux_xfrm_enabled());
186 }
187
selinux_netcache_avc_callback(u32 event)188 static int selinux_netcache_avc_callback(u32 event)
189 {
190 if (event == AVC_CALLBACK_RESET) {
191 sel_netif_flush();
192 sel_netnode_flush();
193 sel_netport_flush();
194 synchronize_net();
195 }
196 return 0;
197 }
198
selinux_lsm_notifier_avc_callback(u32 event)199 static int selinux_lsm_notifier_avc_callback(u32 event)
200 {
201 if (event == AVC_CALLBACK_RESET) {
202 sel_ib_pkey_flush();
203 call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL);
204 }
205
206 return 0;
207 }
208
209 /*
210 * initialise the security for the init task
211 */
cred_init_security(void)212 static void cred_init_security(void)
213 {
214 struct task_security_struct *tsec;
215
216 tsec = selinux_cred(unrcu_pointer(current->real_cred));
217 tsec->osid = tsec->sid = SECINITSID_KERNEL;
218 }
219
220 /*
221 * get the security ID of a set of credentials
222 */
cred_sid(const struct cred * cred)223 static inline u32 cred_sid(const struct cred *cred)
224 {
225 const struct task_security_struct *tsec;
226
227 tsec = selinux_cred(cred);
228 return tsec->sid;
229 }
230
__ad_net_init(struct common_audit_data * ad,struct lsm_network_audit * net,int ifindex,struct sock * sk,u16 family)231 static void __ad_net_init(struct common_audit_data *ad,
232 struct lsm_network_audit *net,
233 int ifindex, struct sock *sk, u16 family)
234 {
235 ad->type = LSM_AUDIT_DATA_NET;
236 ad->u.net = net;
237 net->netif = ifindex;
238 net->sk = sk;
239 net->family = family;
240 }
241
ad_net_init_from_sk(struct common_audit_data * ad,struct lsm_network_audit * net,struct sock * sk)242 static void ad_net_init_from_sk(struct common_audit_data *ad,
243 struct lsm_network_audit *net,
244 struct sock *sk)
245 {
246 __ad_net_init(ad, net, 0, sk, 0);
247 }
248
ad_net_init_from_iif(struct common_audit_data * ad,struct lsm_network_audit * net,int ifindex,u16 family)249 static void ad_net_init_from_iif(struct common_audit_data *ad,
250 struct lsm_network_audit *net,
251 int ifindex, u16 family)
252 {
253 __ad_net_init(ad, net, ifindex, NULL, family);
254 }
255
256 /*
257 * get the objective security ID of a task
258 */
task_sid_obj(const struct task_struct * task)259 static inline u32 task_sid_obj(const struct task_struct *task)
260 {
261 u32 sid;
262
263 rcu_read_lock();
264 sid = cred_sid(__task_cred(task));
265 rcu_read_unlock();
266 return sid;
267 }
268
269 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
270
271 /*
272 * Try reloading inode security labels that have been marked as invalid. The
273 * @may_sleep parameter indicates when sleeping and thus reloading labels is
274 * allowed; when set to false, returns -ECHILD when the label is
275 * invalid. The @dentry parameter should be set to a dentry of the inode.
276 */
__inode_security_revalidate(struct inode * inode,struct dentry * dentry,bool may_sleep)277 static int __inode_security_revalidate(struct inode *inode,
278 struct dentry *dentry,
279 bool may_sleep)
280 {
281 struct inode_security_struct *isec = selinux_inode(inode);
282
283 might_sleep_if(may_sleep);
284
285 /*
286 * The check of isec->initialized below is racy but
287 * inode_doinit_with_dentry() will recheck with
288 * isec->lock held.
289 */
290 if (selinux_initialized() &&
291 data_race(isec->initialized != LABEL_INITIALIZED)) {
292 if (!may_sleep)
293 return -ECHILD;
294
295 /*
296 * Try reloading the inode security label. This will fail if
297 * @opt_dentry is NULL and no dentry for this inode can be
298 * found; in that case, continue using the old label.
299 */
300 inode_doinit_with_dentry(inode, dentry);
301 }
302 return 0;
303 }
304
inode_security_novalidate(struct inode * inode)305 static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
306 {
307 return selinux_inode(inode);
308 }
309
inode_security_rcu(struct inode * inode,bool rcu)310 static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
311 {
312 int error;
313
314 error = __inode_security_revalidate(inode, NULL, !rcu);
315 if (error)
316 return ERR_PTR(error);
317 return selinux_inode(inode);
318 }
319
320 /*
321 * Get the security label of an inode.
322 */
inode_security(struct inode * inode)323 static struct inode_security_struct *inode_security(struct inode *inode)
324 {
325 __inode_security_revalidate(inode, NULL, true);
326 return selinux_inode(inode);
327 }
328
backing_inode_security_novalidate(struct dentry * dentry)329 static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
330 {
331 struct inode *inode = d_backing_inode(dentry);
332
333 return selinux_inode(inode);
334 }
335
336 /*
337 * Get the security label of a dentry's backing inode.
338 */
backing_inode_security(struct dentry * dentry)339 static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
340 {
341 struct inode *inode = d_backing_inode(dentry);
342
343 __inode_security_revalidate(inode, dentry, true);
344 return selinux_inode(inode);
345 }
346
inode_free_security(struct inode * inode)347 static void inode_free_security(struct inode *inode)
348 {
349 struct inode_security_struct *isec = selinux_inode(inode);
350 struct superblock_security_struct *sbsec;
351
352 if (!isec)
353 return;
354 sbsec = selinux_superblock(inode->i_sb);
355 /*
356 * As not all inode security structures are in a list, we check for
357 * empty list outside of the lock to make sure that we won't waste
358 * time taking a lock doing nothing.
359 *
360 * The list_del_init() function can be safely called more than once.
361 * It should not be possible for this function to be called with
362 * concurrent list_add(), but for better safety against future changes
363 * in the code, we use list_empty_careful() here.
364 */
365 if (!list_empty_careful(&isec->list)) {
366 spin_lock(&sbsec->isec_lock);
367 list_del_init(&isec->list);
368 spin_unlock(&sbsec->isec_lock);
369 }
370 }
371
372 struct selinux_mnt_opts {
373 u32 fscontext_sid;
374 u32 context_sid;
375 u32 rootcontext_sid;
376 u32 defcontext_sid;
377 };
378
selinux_free_mnt_opts(void * mnt_opts)379 static void selinux_free_mnt_opts(void *mnt_opts)
380 {
381 kfree(mnt_opts);
382 }
383
384 enum {
385 Opt_error = -1,
386 Opt_context = 0,
387 Opt_defcontext = 1,
388 Opt_fscontext = 2,
389 Opt_rootcontext = 3,
390 Opt_seclabel = 4,
391 };
392
393 #define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg}
394 static const struct {
395 const char *name;
396 int len;
397 int opt;
398 bool has_arg;
399 } tokens[] = {
400 A(context, true),
401 A(fscontext, true),
402 A(defcontext, true),
403 A(rootcontext, true),
404 A(seclabel, false),
405 };
406 #undef A
407
match_opt_prefix(char * s,int l,char ** arg)408 static int match_opt_prefix(char *s, int l, char **arg)
409 {
410 int i;
411
412 for (i = 0; i < ARRAY_SIZE(tokens); i++) {
413 size_t len = tokens[i].len;
414 if (len > l || memcmp(s, tokens[i].name, len))
415 continue;
416 if (tokens[i].has_arg) {
417 if (len == l || s[len] != '=')
418 continue;
419 *arg = s + len + 1;
420 } else if (len != l)
421 continue;
422 return tokens[i].opt;
423 }
424 return Opt_error;
425 }
426
427 #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
428
may_context_mount_sb_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)429 static int may_context_mount_sb_relabel(u32 sid,
430 struct superblock_security_struct *sbsec,
431 const struct cred *cred)
432 {
433 const struct task_security_struct *tsec = selinux_cred(cred);
434 int rc;
435
436 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
437 FILESYSTEM__RELABELFROM, NULL);
438 if (rc)
439 return rc;
440
441 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
442 FILESYSTEM__RELABELTO, NULL);
443 return rc;
444 }
445
may_context_mount_inode_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)446 static int may_context_mount_inode_relabel(u32 sid,
447 struct superblock_security_struct *sbsec,
448 const struct cred *cred)
449 {
450 const struct task_security_struct *tsec = selinux_cred(cred);
451 int rc;
452 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
453 FILESYSTEM__RELABELFROM, NULL);
454 if (rc)
455 return rc;
456
457 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
458 FILESYSTEM__ASSOCIATE, NULL);
459 return rc;
460 }
461
selinux_is_genfs_special_handling(struct super_block * sb)462 static int selinux_is_genfs_special_handling(struct super_block *sb)
463 {
464 /* Special handling. Genfs but also in-core setxattr handler */
465 return !strcmp(sb->s_type->name, "sysfs") ||
466 !strcmp(sb->s_type->name, "pstore") ||
467 !strcmp(sb->s_type->name, "debugfs") ||
468 !strcmp(sb->s_type->name, "tracefs") ||
469 !strcmp(sb->s_type->name, "rootfs") ||
470 (selinux_policycap_cgroupseclabel() &&
471 (!strcmp(sb->s_type->name, "cgroup") ||
472 !strcmp(sb->s_type->name, "cgroup2")));
473 }
474
selinux_is_sblabel_mnt(struct super_block * sb)475 static int selinux_is_sblabel_mnt(struct super_block *sb)
476 {
477 struct superblock_security_struct *sbsec = selinux_superblock(sb);
478
479 /*
480 * IMPORTANT: Double-check logic in this function when adding a new
481 * SECURITY_FS_USE_* definition!
482 */
483 BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7);
484
485 switch (sbsec->behavior) {
486 case SECURITY_FS_USE_XATTR:
487 case SECURITY_FS_USE_TRANS:
488 case SECURITY_FS_USE_TASK:
489 case SECURITY_FS_USE_NATIVE:
490 return 1;
491
492 case SECURITY_FS_USE_GENFS:
493 return selinux_is_genfs_special_handling(sb);
494
495 /* Never allow relabeling on context mounts */
496 case SECURITY_FS_USE_MNTPOINT:
497 case SECURITY_FS_USE_NONE:
498 default:
499 return 0;
500 }
501 }
502
sb_check_xattr_support(struct super_block * sb)503 static int sb_check_xattr_support(struct super_block *sb)
504 {
505 struct superblock_security_struct *sbsec = selinux_superblock(sb);
506 struct dentry *root = sb->s_root;
507 struct inode *root_inode = d_backing_inode(root);
508 u32 sid;
509 int rc;
510
511 /*
512 * Make sure that the xattr handler exists and that no
513 * error other than -ENODATA is returned by getxattr on
514 * the root directory. -ENODATA is ok, as this may be
515 * the first boot of the SELinux kernel before we have
516 * assigned xattr values to the filesystem.
517 */
518 if (!(root_inode->i_opflags & IOP_XATTR)) {
519 pr_warn("SELinux: (dev %s, type %s) has no xattr support\n",
520 sb->s_id, sb->s_type->name);
521 goto fallback;
522 }
523
524 rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0);
525 if (rc < 0 && rc != -ENODATA) {
526 if (rc == -EOPNOTSUPP) {
527 pr_warn("SELinux: (dev %s, type %s) has no security xattr handler\n",
528 sb->s_id, sb->s_type->name);
529 goto fallback;
530 } else {
531 pr_warn("SELinux: (dev %s, type %s) getxattr errno %d\n",
532 sb->s_id, sb->s_type->name, -rc);
533 return rc;
534 }
535 }
536 return 0;
537
538 fallback:
539 /* No xattr support - try to fallback to genfs if possible. */
540 rc = security_genfs_sid(sb->s_type->name, "/",
541 SECCLASS_DIR, &sid);
542 if (rc)
543 return -EOPNOTSUPP;
544
545 pr_warn("SELinux: (dev %s, type %s) falling back to genfs\n",
546 sb->s_id, sb->s_type->name);
547 sbsec->behavior = SECURITY_FS_USE_GENFS;
548 sbsec->sid = sid;
549 return 0;
550 }
551
sb_finish_set_opts(struct super_block * sb)552 static int sb_finish_set_opts(struct super_block *sb)
553 {
554 struct superblock_security_struct *sbsec = selinux_superblock(sb);
555 struct dentry *root = sb->s_root;
556 struct inode *root_inode = d_backing_inode(root);
557 int rc = 0;
558
559 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
560 rc = sb_check_xattr_support(sb);
561 if (rc)
562 return rc;
563 }
564
565 sbsec->flags |= SE_SBINITIALIZED;
566
567 /*
568 * Explicitly set or clear SBLABEL_MNT. It's not sufficient to simply
569 * leave the flag untouched because sb_clone_mnt_opts might be handing
570 * us a superblock that needs the flag to be cleared.
571 */
572 if (selinux_is_sblabel_mnt(sb))
573 sbsec->flags |= SBLABEL_MNT;
574 else
575 sbsec->flags &= ~SBLABEL_MNT;
576
577 /* Initialize the root inode. */
578 rc = inode_doinit_with_dentry(root_inode, root);
579
580 /* Initialize any other inodes associated with the superblock, e.g.
581 inodes created prior to initial policy load or inodes created
582 during get_sb by a pseudo filesystem that directly
583 populates itself. */
584 spin_lock(&sbsec->isec_lock);
585 while (!list_empty(&sbsec->isec_head)) {
586 struct inode_security_struct *isec =
587 list_first_entry(&sbsec->isec_head,
588 struct inode_security_struct, list);
589 struct inode *inode = isec->inode;
590 list_del_init(&isec->list);
591 spin_unlock(&sbsec->isec_lock);
592 inode = igrab(inode);
593 if (inode) {
594 if (!IS_PRIVATE(inode))
595 inode_doinit_with_dentry(inode, NULL);
596 iput(inode);
597 }
598 spin_lock(&sbsec->isec_lock);
599 }
600 spin_unlock(&sbsec->isec_lock);
601 return rc;
602 }
603
bad_option(struct superblock_security_struct * sbsec,char flag,u32 old_sid,u32 new_sid)604 static int bad_option(struct superblock_security_struct *sbsec, char flag,
605 u32 old_sid, u32 new_sid)
606 {
607 char mnt_flags = sbsec->flags & SE_MNTMASK;
608
609 /* check if the old mount command had the same options */
610 if (sbsec->flags & SE_SBINITIALIZED)
611 if (!(sbsec->flags & flag) ||
612 (old_sid != new_sid))
613 return 1;
614
615 /* check if we were passed the same options twice,
616 * aka someone passed context=a,context=b
617 */
618 if (!(sbsec->flags & SE_SBINITIALIZED))
619 if (mnt_flags & flag)
620 return 1;
621 return 0;
622 }
623
624 /*
625 * Allow filesystems with binary mount data to explicitly set mount point
626 * labeling information.
627 */
selinux_set_mnt_opts(struct super_block * sb,void * mnt_opts,unsigned long kern_flags,unsigned long * set_kern_flags)628 static int selinux_set_mnt_opts(struct super_block *sb,
629 void *mnt_opts,
630 unsigned long kern_flags,
631 unsigned long *set_kern_flags)
632 {
633 const struct cred *cred = current_cred();
634 struct superblock_security_struct *sbsec = selinux_superblock(sb);
635 struct dentry *root = sb->s_root;
636 struct selinux_mnt_opts *opts = mnt_opts;
637 struct inode_security_struct *root_isec;
638 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
639 u32 defcontext_sid = 0;
640 int rc = 0;
641
642 /*
643 * Specifying internal flags without providing a place to
644 * place the results is not allowed
645 */
646 if (kern_flags && !set_kern_flags)
647 return -EINVAL;
648
649 mutex_lock(&sbsec->lock);
650
651 if (!selinux_initialized()) {
652 if (!opts) {
653 /* Defer initialization until selinux_complete_init,
654 after the initial policy is loaded and the security
655 server is ready to handle calls. */
656 if (kern_flags & SECURITY_LSM_NATIVE_LABELS) {
657 sbsec->flags |= SE_SBNATIVE;
658 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
659 }
660 goto out;
661 }
662 rc = -EINVAL;
663 pr_warn("SELinux: Unable to set superblock options "
664 "before the security server is initialized\n");
665 goto out;
666 }
667
668 /*
669 * Binary mount data FS will come through this function twice. Once
670 * from an explicit call and once from the generic calls from the vfs.
671 * Since the generic VFS calls will not contain any security mount data
672 * we need to skip the double mount verification.
673 *
674 * This does open a hole in which we will not notice if the first
675 * mount using this sb set explicit options and a second mount using
676 * this sb does not set any security options. (The first options
677 * will be used for both mounts)
678 */
679 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
680 && !opts)
681 goto out;
682
683 root_isec = backing_inode_security_novalidate(root);
684
685 /*
686 * parse the mount options, check if they are valid sids.
687 * also check if someone is trying to mount the same sb more
688 * than once with different security options.
689 */
690 if (opts) {
691 if (opts->fscontext_sid) {
692 fscontext_sid = opts->fscontext_sid;
693 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
694 fscontext_sid))
695 goto out_double_mount;
696 sbsec->flags |= FSCONTEXT_MNT;
697 }
698 if (opts->context_sid) {
699 context_sid = opts->context_sid;
700 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
701 context_sid))
702 goto out_double_mount;
703 sbsec->flags |= CONTEXT_MNT;
704 }
705 if (opts->rootcontext_sid) {
706 rootcontext_sid = opts->rootcontext_sid;
707 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
708 rootcontext_sid))
709 goto out_double_mount;
710 sbsec->flags |= ROOTCONTEXT_MNT;
711 }
712 if (opts->defcontext_sid) {
713 defcontext_sid = opts->defcontext_sid;
714 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
715 defcontext_sid))
716 goto out_double_mount;
717 sbsec->flags |= DEFCONTEXT_MNT;
718 }
719 }
720
721 if (sbsec->flags & SE_SBINITIALIZED) {
722 /* previously mounted with options, but not on this attempt? */
723 if ((sbsec->flags & SE_MNTMASK) && !opts)
724 goto out_double_mount;
725 rc = 0;
726 goto out;
727 }
728
729 if (strcmp(sb->s_type->name, "proc") == 0)
730 sbsec->flags |= SE_SBPROC | SE_SBGENFS;
731
732 if (!strcmp(sb->s_type->name, "debugfs") ||
733 !strcmp(sb->s_type->name, "tracefs") ||
734 !strcmp(sb->s_type->name, "binder") ||
735 !strcmp(sb->s_type->name, "bpf") ||
736 !strcmp(sb->s_type->name, "pstore") ||
737 !strcmp(sb->s_type->name, "securityfs"))
738 sbsec->flags |= SE_SBGENFS;
739
740 if (!strcmp(sb->s_type->name, "sysfs") ||
741 !strcmp(sb->s_type->name, "cgroup") ||
742 !strcmp(sb->s_type->name, "cgroup2"))
743 sbsec->flags |= SE_SBGENFS | SE_SBGENFS_XATTR;
744
745 if (!sbsec->behavior) {
746 /*
747 * Determine the labeling behavior to use for this
748 * filesystem type.
749 */
750 rc = security_fs_use(sb);
751 if (rc) {
752 pr_warn("%s: security_fs_use(%s) returned %d\n",
753 __func__, sb->s_type->name, rc);
754 goto out;
755 }
756 }
757
758 /*
759 * If this is a user namespace mount and the filesystem type is not
760 * explicitly whitelisted, then no contexts are allowed on the command
761 * line and security labels must be ignored.
762 */
763 if (sb->s_user_ns != &init_user_ns &&
764 strcmp(sb->s_type->name, "tmpfs") &&
765 strcmp(sb->s_type->name, "ramfs") &&
766 strcmp(sb->s_type->name, "devpts") &&
767 strcmp(sb->s_type->name, "overlay")) {
768 if (context_sid || fscontext_sid || rootcontext_sid ||
769 defcontext_sid) {
770 rc = -EACCES;
771 goto out;
772 }
773 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
774 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
775 rc = security_transition_sid(current_sid(),
776 current_sid(),
777 SECCLASS_FILE, NULL,
778 &sbsec->mntpoint_sid);
779 if (rc)
780 goto out;
781 }
782 goto out_set_opts;
783 }
784
785 /* sets the context of the superblock for the fs being mounted. */
786 if (fscontext_sid) {
787 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
788 if (rc)
789 goto out;
790
791 sbsec->sid = fscontext_sid;
792 }
793
794 /*
795 * Switch to using mount point labeling behavior.
796 * sets the label used on all file below the mountpoint, and will set
797 * the superblock context if not already set.
798 */
799 if (sbsec->flags & SE_SBNATIVE) {
800 /*
801 * This means we are initializing a superblock that has been
802 * mounted before the SELinux was initialized and the
803 * filesystem requested native labeling. We had already
804 * returned SECURITY_LSM_NATIVE_LABELS in *set_kern_flags
805 * in the original mount attempt, so now we just need to set
806 * the SECURITY_FS_USE_NATIVE behavior.
807 */
808 sbsec->behavior = SECURITY_FS_USE_NATIVE;
809 } else if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
810 sbsec->behavior = SECURITY_FS_USE_NATIVE;
811 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
812 }
813
814 if (context_sid) {
815 if (!fscontext_sid) {
816 rc = may_context_mount_sb_relabel(context_sid, sbsec,
817 cred);
818 if (rc)
819 goto out;
820 sbsec->sid = context_sid;
821 } else {
822 rc = may_context_mount_inode_relabel(context_sid, sbsec,
823 cred);
824 if (rc)
825 goto out;
826 }
827 if (!rootcontext_sid)
828 rootcontext_sid = context_sid;
829
830 sbsec->mntpoint_sid = context_sid;
831 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
832 }
833
834 if (rootcontext_sid) {
835 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
836 cred);
837 if (rc)
838 goto out;
839
840 root_isec->sid = rootcontext_sid;
841 root_isec->initialized = LABEL_INITIALIZED;
842 }
843
844 if (defcontext_sid) {
845 if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
846 sbsec->behavior != SECURITY_FS_USE_NATIVE) {
847 rc = -EINVAL;
848 pr_warn("SELinux: defcontext option is "
849 "invalid for this filesystem type\n");
850 goto out;
851 }
852
853 if (defcontext_sid != sbsec->def_sid) {
854 rc = may_context_mount_inode_relabel(defcontext_sid,
855 sbsec, cred);
856 if (rc)
857 goto out;
858 }
859
860 sbsec->def_sid = defcontext_sid;
861 }
862
863 out_set_opts:
864 rc = sb_finish_set_opts(sb);
865 out:
866 mutex_unlock(&sbsec->lock);
867 return rc;
868 out_double_mount:
869 rc = -EINVAL;
870 pr_warn("SELinux: mount invalid. Same superblock, different "
871 "security settings for (dev %s, type %s)\n", sb->s_id,
872 sb->s_type->name);
873 goto out;
874 }
875
selinux_cmp_sb_context(const struct super_block * oldsb,const struct super_block * newsb)876 static int selinux_cmp_sb_context(const struct super_block *oldsb,
877 const struct super_block *newsb)
878 {
879 struct superblock_security_struct *old = selinux_superblock(oldsb);
880 struct superblock_security_struct *new = selinux_superblock(newsb);
881 char oldflags = old->flags & SE_MNTMASK;
882 char newflags = new->flags & SE_MNTMASK;
883
884 if (oldflags != newflags)
885 goto mismatch;
886 if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
887 goto mismatch;
888 if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
889 goto mismatch;
890 if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
891 goto mismatch;
892 if (oldflags & ROOTCONTEXT_MNT) {
893 struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
894 struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
895 if (oldroot->sid != newroot->sid)
896 goto mismatch;
897 }
898 return 0;
899 mismatch:
900 pr_warn("SELinux: mount invalid. Same superblock, "
901 "different security settings for (dev %s, "
902 "type %s)\n", newsb->s_id, newsb->s_type->name);
903 return -EBUSY;
904 }
905
selinux_sb_clone_mnt_opts(const struct super_block * oldsb,struct super_block * newsb,unsigned long kern_flags,unsigned long * set_kern_flags)906 static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
907 struct super_block *newsb,
908 unsigned long kern_flags,
909 unsigned long *set_kern_flags)
910 {
911 int rc = 0;
912 const struct superblock_security_struct *oldsbsec =
913 selinux_superblock(oldsb);
914 struct superblock_security_struct *newsbsec = selinux_superblock(newsb);
915
916 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
917 int set_context = (oldsbsec->flags & CONTEXT_MNT);
918 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
919
920 /*
921 * Specifying internal flags without providing a place to
922 * place the results is not allowed.
923 */
924 if (kern_flags && !set_kern_flags)
925 return -EINVAL;
926
927 mutex_lock(&newsbsec->lock);
928
929 /*
930 * if the parent was able to be mounted it clearly had no special lsm
931 * mount options. thus we can safely deal with this superblock later
932 */
933 if (!selinux_initialized()) {
934 if (kern_flags & SECURITY_LSM_NATIVE_LABELS) {
935 newsbsec->flags |= SE_SBNATIVE;
936 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
937 }
938 goto out;
939 }
940
941 /* how can we clone if the old one wasn't set up?? */
942 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
943
944 /* if fs is reusing a sb, make sure that the contexts match */
945 if (newsbsec->flags & SE_SBINITIALIZED) {
946 mutex_unlock(&newsbsec->lock);
947 if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context)
948 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
949 return selinux_cmp_sb_context(oldsb, newsb);
950 }
951
952 newsbsec->flags = oldsbsec->flags;
953
954 newsbsec->sid = oldsbsec->sid;
955 newsbsec->def_sid = oldsbsec->def_sid;
956 newsbsec->behavior = oldsbsec->behavior;
957
958 if (newsbsec->behavior == SECURITY_FS_USE_NATIVE &&
959 !(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) {
960 rc = security_fs_use(newsb);
961 if (rc)
962 goto out;
963 }
964
965 if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) {
966 newsbsec->behavior = SECURITY_FS_USE_NATIVE;
967 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
968 }
969
970 if (set_context) {
971 u32 sid = oldsbsec->mntpoint_sid;
972
973 if (!set_fscontext)
974 newsbsec->sid = sid;
975 if (!set_rootcontext) {
976 struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
977 newisec->sid = sid;
978 }
979 newsbsec->mntpoint_sid = sid;
980 }
981 if (set_rootcontext) {
982 const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
983 struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
984
985 newisec->sid = oldisec->sid;
986 }
987
988 sb_finish_set_opts(newsb);
989 out:
990 mutex_unlock(&newsbsec->lock);
991 return rc;
992 }
993
994 /*
995 * NOTE: the caller is responsible for freeing the memory even if on error.
996 */
selinux_add_opt(int token,const char * s,void ** mnt_opts)997 static int selinux_add_opt(int token, const char *s, void **mnt_opts)
998 {
999 struct selinux_mnt_opts *opts = *mnt_opts;
1000 u32 *dst_sid;
1001 int rc;
1002
1003 if (token == Opt_seclabel)
1004 /* eaten and completely ignored */
1005 return 0;
1006 if (!s)
1007 return -EINVAL;
1008
1009 if (!selinux_initialized()) {
1010 pr_warn("SELinux: Unable to set superblock options before the security server is initialized\n");
1011 return -EINVAL;
1012 }
1013
1014 if (!opts) {
1015 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1016 if (!opts)
1017 return -ENOMEM;
1018 *mnt_opts = opts;
1019 }
1020
1021 switch (token) {
1022 case Opt_context:
1023 if (opts->context_sid || opts->defcontext_sid)
1024 goto err;
1025 dst_sid = &opts->context_sid;
1026 break;
1027 case Opt_fscontext:
1028 if (opts->fscontext_sid)
1029 goto err;
1030 dst_sid = &opts->fscontext_sid;
1031 break;
1032 case Opt_rootcontext:
1033 if (opts->rootcontext_sid)
1034 goto err;
1035 dst_sid = &opts->rootcontext_sid;
1036 break;
1037 case Opt_defcontext:
1038 if (opts->context_sid || opts->defcontext_sid)
1039 goto err;
1040 dst_sid = &opts->defcontext_sid;
1041 break;
1042 default:
1043 WARN_ON(1);
1044 return -EINVAL;
1045 }
1046 rc = security_context_str_to_sid(s, dst_sid, GFP_KERNEL);
1047 if (rc)
1048 pr_warn("SELinux: security_context_str_to_sid (%s) failed with errno=%d\n",
1049 s, rc);
1050 return rc;
1051
1052 err:
1053 pr_warn(SEL_MOUNT_FAIL_MSG);
1054 return -EINVAL;
1055 }
1056
show_sid(struct seq_file * m,u32 sid)1057 static int show_sid(struct seq_file *m, u32 sid)
1058 {
1059 char *context = NULL;
1060 u32 len;
1061 int rc;
1062
1063 rc = security_sid_to_context(sid, &context, &len);
1064 if (!rc) {
1065 bool has_comma = strchr(context, ',');
1066
1067 seq_putc(m, '=');
1068 if (has_comma)
1069 seq_putc(m, '\"');
1070 seq_escape(m, context, "\"\n\\");
1071 if (has_comma)
1072 seq_putc(m, '\"');
1073 }
1074 kfree(context);
1075 return rc;
1076 }
1077
selinux_sb_show_options(struct seq_file * m,struct super_block * sb)1078 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1079 {
1080 struct superblock_security_struct *sbsec = selinux_superblock(sb);
1081 int rc;
1082
1083 if (!(sbsec->flags & SE_SBINITIALIZED))
1084 return 0;
1085
1086 if (!selinux_initialized())
1087 return 0;
1088
1089 if (sbsec->flags & FSCONTEXT_MNT) {
1090 seq_putc(m, ',');
1091 seq_puts(m, FSCONTEXT_STR);
1092 rc = show_sid(m, sbsec->sid);
1093 if (rc)
1094 return rc;
1095 }
1096 if (sbsec->flags & CONTEXT_MNT) {
1097 seq_putc(m, ',');
1098 seq_puts(m, CONTEXT_STR);
1099 rc = show_sid(m, sbsec->mntpoint_sid);
1100 if (rc)
1101 return rc;
1102 }
1103 if (sbsec->flags & DEFCONTEXT_MNT) {
1104 seq_putc(m, ',');
1105 seq_puts(m, DEFCONTEXT_STR);
1106 rc = show_sid(m, sbsec->def_sid);
1107 if (rc)
1108 return rc;
1109 }
1110 if (sbsec->flags & ROOTCONTEXT_MNT) {
1111 struct dentry *root = sb->s_root;
1112 struct inode_security_struct *isec = backing_inode_security(root);
1113 seq_putc(m, ',');
1114 seq_puts(m, ROOTCONTEXT_STR);
1115 rc = show_sid(m, isec->sid);
1116 if (rc)
1117 return rc;
1118 }
1119 if (sbsec->flags & SBLABEL_MNT) {
1120 seq_putc(m, ',');
1121 seq_puts(m, SECLABEL_STR);
1122 }
1123 return 0;
1124 }
1125
inode_mode_to_security_class(umode_t mode)1126 static inline u16 inode_mode_to_security_class(umode_t mode)
1127 {
1128 switch (mode & S_IFMT) {
1129 case S_IFSOCK:
1130 return SECCLASS_SOCK_FILE;
1131 case S_IFLNK:
1132 return SECCLASS_LNK_FILE;
1133 case S_IFREG:
1134 return SECCLASS_FILE;
1135 case S_IFBLK:
1136 return SECCLASS_BLK_FILE;
1137 case S_IFDIR:
1138 return SECCLASS_DIR;
1139 case S_IFCHR:
1140 return SECCLASS_CHR_FILE;
1141 case S_IFIFO:
1142 return SECCLASS_FIFO_FILE;
1143
1144 }
1145
1146 return SECCLASS_FILE;
1147 }
1148
default_protocol_stream(int protocol)1149 static inline int default_protocol_stream(int protocol)
1150 {
1151 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP ||
1152 protocol == IPPROTO_MPTCP);
1153 }
1154
default_protocol_dgram(int protocol)1155 static inline int default_protocol_dgram(int protocol)
1156 {
1157 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1158 }
1159
socket_type_to_security_class(int family,int type,int protocol)1160 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1161 {
1162 bool extsockclass = selinux_policycap_extsockclass();
1163
1164 switch (family) {
1165 case PF_UNIX:
1166 switch (type) {
1167 case SOCK_STREAM:
1168 case SOCK_SEQPACKET:
1169 return SECCLASS_UNIX_STREAM_SOCKET;
1170 case SOCK_DGRAM:
1171 case SOCK_RAW:
1172 return SECCLASS_UNIX_DGRAM_SOCKET;
1173 }
1174 break;
1175 case PF_INET:
1176 case PF_INET6:
1177 switch (type) {
1178 case SOCK_STREAM:
1179 case SOCK_SEQPACKET:
1180 if (default_protocol_stream(protocol))
1181 return SECCLASS_TCP_SOCKET;
1182 else if (extsockclass && protocol == IPPROTO_SCTP)
1183 return SECCLASS_SCTP_SOCKET;
1184 else
1185 return SECCLASS_RAWIP_SOCKET;
1186 case SOCK_DGRAM:
1187 if (default_protocol_dgram(protocol))
1188 return SECCLASS_UDP_SOCKET;
1189 else if (extsockclass && (protocol == IPPROTO_ICMP ||
1190 protocol == IPPROTO_ICMPV6))
1191 return SECCLASS_ICMP_SOCKET;
1192 else
1193 return SECCLASS_RAWIP_SOCKET;
1194 case SOCK_DCCP:
1195 return SECCLASS_DCCP_SOCKET;
1196 default:
1197 return SECCLASS_RAWIP_SOCKET;
1198 }
1199 break;
1200 case PF_NETLINK:
1201 switch (protocol) {
1202 case NETLINK_ROUTE:
1203 return SECCLASS_NETLINK_ROUTE_SOCKET;
1204 case NETLINK_SOCK_DIAG:
1205 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1206 case NETLINK_NFLOG:
1207 return SECCLASS_NETLINK_NFLOG_SOCKET;
1208 case NETLINK_XFRM:
1209 return SECCLASS_NETLINK_XFRM_SOCKET;
1210 case NETLINK_SELINUX:
1211 return SECCLASS_NETLINK_SELINUX_SOCKET;
1212 case NETLINK_ISCSI:
1213 return SECCLASS_NETLINK_ISCSI_SOCKET;
1214 case NETLINK_AUDIT:
1215 return SECCLASS_NETLINK_AUDIT_SOCKET;
1216 case NETLINK_FIB_LOOKUP:
1217 return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET;
1218 case NETLINK_CONNECTOR:
1219 return SECCLASS_NETLINK_CONNECTOR_SOCKET;
1220 case NETLINK_NETFILTER:
1221 return SECCLASS_NETLINK_NETFILTER_SOCKET;
1222 case NETLINK_DNRTMSG:
1223 return SECCLASS_NETLINK_DNRT_SOCKET;
1224 case NETLINK_KOBJECT_UEVENT:
1225 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1226 case NETLINK_GENERIC:
1227 return SECCLASS_NETLINK_GENERIC_SOCKET;
1228 case NETLINK_SCSITRANSPORT:
1229 return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET;
1230 case NETLINK_RDMA:
1231 return SECCLASS_NETLINK_RDMA_SOCKET;
1232 case NETLINK_CRYPTO:
1233 return SECCLASS_NETLINK_CRYPTO_SOCKET;
1234 default:
1235 return SECCLASS_NETLINK_SOCKET;
1236 }
1237 case PF_PACKET:
1238 return SECCLASS_PACKET_SOCKET;
1239 case PF_KEY:
1240 return SECCLASS_KEY_SOCKET;
1241 case PF_APPLETALK:
1242 return SECCLASS_APPLETALK_SOCKET;
1243 }
1244
1245 if (extsockclass) {
1246 switch (family) {
1247 case PF_AX25:
1248 return SECCLASS_AX25_SOCKET;
1249 case PF_IPX:
1250 return SECCLASS_IPX_SOCKET;
1251 case PF_NETROM:
1252 return SECCLASS_NETROM_SOCKET;
1253 case PF_ATMPVC:
1254 return SECCLASS_ATMPVC_SOCKET;
1255 case PF_X25:
1256 return SECCLASS_X25_SOCKET;
1257 case PF_ROSE:
1258 return SECCLASS_ROSE_SOCKET;
1259 case PF_DECnet:
1260 return SECCLASS_DECNET_SOCKET;
1261 case PF_ATMSVC:
1262 return SECCLASS_ATMSVC_SOCKET;
1263 case PF_RDS:
1264 return SECCLASS_RDS_SOCKET;
1265 case PF_IRDA:
1266 return SECCLASS_IRDA_SOCKET;
1267 case PF_PPPOX:
1268 return SECCLASS_PPPOX_SOCKET;
1269 case PF_LLC:
1270 return SECCLASS_LLC_SOCKET;
1271 case PF_CAN:
1272 return SECCLASS_CAN_SOCKET;
1273 case PF_TIPC:
1274 return SECCLASS_TIPC_SOCKET;
1275 case PF_BLUETOOTH:
1276 return SECCLASS_BLUETOOTH_SOCKET;
1277 case PF_IUCV:
1278 return SECCLASS_IUCV_SOCKET;
1279 case PF_RXRPC:
1280 return SECCLASS_RXRPC_SOCKET;
1281 case PF_ISDN:
1282 return SECCLASS_ISDN_SOCKET;
1283 case PF_PHONET:
1284 return SECCLASS_PHONET_SOCKET;
1285 case PF_IEEE802154:
1286 return SECCLASS_IEEE802154_SOCKET;
1287 case PF_CAIF:
1288 return SECCLASS_CAIF_SOCKET;
1289 case PF_ALG:
1290 return SECCLASS_ALG_SOCKET;
1291 case PF_NFC:
1292 return SECCLASS_NFC_SOCKET;
1293 case PF_VSOCK:
1294 return SECCLASS_VSOCK_SOCKET;
1295 case PF_KCM:
1296 return SECCLASS_KCM_SOCKET;
1297 case PF_QIPCRTR:
1298 return SECCLASS_QIPCRTR_SOCKET;
1299 case PF_SMC:
1300 return SECCLASS_SMC_SOCKET;
1301 case PF_XDP:
1302 return SECCLASS_XDP_SOCKET;
1303 case PF_MCTP:
1304 return SECCLASS_MCTP_SOCKET;
1305 #if PF_MAX > 46
1306 #error New address family defined, please update this function.
1307 #endif
1308 }
1309 }
1310
1311 return SECCLASS_SOCKET;
1312 }
1313
selinux_genfs_get_sid(struct dentry * dentry,u16 tclass,u16 flags,u32 * sid)1314 static int selinux_genfs_get_sid(struct dentry *dentry,
1315 u16 tclass,
1316 u16 flags,
1317 u32 *sid)
1318 {
1319 int rc;
1320 struct super_block *sb = dentry->d_sb;
1321 char *buffer, *path;
1322
1323 buffer = (char *)__get_free_page(GFP_KERNEL);
1324 if (!buffer)
1325 return -ENOMEM;
1326
1327 path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1328 if (IS_ERR(path))
1329 rc = PTR_ERR(path);
1330 else {
1331 if (flags & SE_SBPROC) {
1332 /* each process gets a /proc/PID/ entry. Strip off the
1333 * PID part to get a valid selinux labeling.
1334 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1335 while (path[1] >= '0' && path[1] <= '9') {
1336 path[1] = '/';
1337 path++;
1338 }
1339 }
1340 rc = security_genfs_sid(sb->s_type->name,
1341 path, tclass, sid);
1342 if (rc == -ENOENT) {
1343 /* No match in policy, mark as unlabeled. */
1344 *sid = SECINITSID_UNLABELED;
1345 rc = 0;
1346 }
1347 }
1348 free_page((unsigned long)buffer);
1349 return rc;
1350 }
1351
inode_doinit_use_xattr(struct inode * inode,struct dentry * dentry,u32 def_sid,u32 * sid)1352 static int inode_doinit_use_xattr(struct inode *inode, struct dentry *dentry,
1353 u32 def_sid, u32 *sid)
1354 {
1355 #define INITCONTEXTLEN 255
1356 char *context;
1357 unsigned int len;
1358 int rc;
1359
1360 len = INITCONTEXTLEN;
1361 context = kmalloc(len + 1, GFP_NOFS);
1362 if (!context)
1363 return -ENOMEM;
1364
1365 context[len] = '\0';
1366 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
1367 if (rc == -ERANGE) {
1368 kfree(context);
1369
1370 /* Need a larger buffer. Query for the right size. */
1371 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
1372 if (rc < 0)
1373 return rc;
1374
1375 len = rc;
1376 context = kmalloc(len + 1, GFP_NOFS);
1377 if (!context)
1378 return -ENOMEM;
1379
1380 context[len] = '\0';
1381 rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX,
1382 context, len);
1383 }
1384 if (rc < 0) {
1385 kfree(context);
1386 if (rc != -ENODATA) {
1387 pr_warn("SELinux: %s: getxattr returned %d for dev=%s ino=%ld\n",
1388 __func__, -rc, inode->i_sb->s_id, inode->i_ino);
1389 return rc;
1390 }
1391 *sid = def_sid;
1392 return 0;
1393 }
1394
1395 rc = security_context_to_sid_default(context, rc, sid,
1396 def_sid, GFP_NOFS);
1397 if (rc) {
1398 char *dev = inode->i_sb->s_id;
1399 unsigned long ino = inode->i_ino;
1400
1401 if (rc == -EINVAL) {
1402 pr_notice_ratelimited("SELinux: inode=%lu on dev=%s was found to have an invalid context=%s. This indicates you may need to relabel the inode or the filesystem in question.\n",
1403 ino, dev, context);
1404 } else {
1405 pr_warn("SELinux: %s: context_to_sid(%s) returned %d for dev=%s ino=%ld\n",
1406 __func__, context, -rc, dev, ino);
1407 }
1408 }
1409 kfree(context);
1410 return 0;
1411 }
1412
1413 /* The inode's security attributes must be initialized before first use. */
inode_doinit_with_dentry(struct inode * inode,struct dentry * opt_dentry)1414 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1415 {
1416 struct superblock_security_struct *sbsec = NULL;
1417 struct inode_security_struct *isec = selinux_inode(inode);
1418 u32 task_sid, sid = 0;
1419 u16 sclass;
1420 struct dentry *dentry;
1421 int rc = 0;
1422
1423 if (isec->initialized == LABEL_INITIALIZED)
1424 return 0;
1425
1426 spin_lock(&isec->lock);
1427 if (isec->initialized == LABEL_INITIALIZED)
1428 goto out_unlock;
1429
1430 if (isec->sclass == SECCLASS_FILE)
1431 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1432
1433 sbsec = selinux_superblock(inode->i_sb);
1434 if (!(sbsec->flags & SE_SBINITIALIZED)) {
1435 /* Defer initialization until selinux_complete_init,
1436 after the initial policy is loaded and the security
1437 server is ready to handle calls. */
1438 spin_lock(&sbsec->isec_lock);
1439 if (list_empty(&isec->list))
1440 list_add(&isec->list, &sbsec->isec_head);
1441 spin_unlock(&sbsec->isec_lock);
1442 goto out_unlock;
1443 }
1444
1445 sclass = isec->sclass;
1446 task_sid = isec->task_sid;
1447 sid = isec->sid;
1448 isec->initialized = LABEL_PENDING;
1449 spin_unlock(&isec->lock);
1450
1451 switch (sbsec->behavior) {
1452 /*
1453 * In case of SECURITY_FS_USE_NATIVE we need to re-fetch the labels
1454 * via xattr when called from delayed_superblock_init().
1455 */
1456 case SECURITY_FS_USE_NATIVE:
1457 case SECURITY_FS_USE_XATTR:
1458 if (!(inode->i_opflags & IOP_XATTR)) {
1459 sid = sbsec->def_sid;
1460 break;
1461 }
1462 /* Need a dentry, since the xattr API requires one.
1463 Life would be simpler if we could just pass the inode. */
1464 if (opt_dentry) {
1465 /* Called from d_instantiate or d_splice_alias. */
1466 dentry = dget(opt_dentry);
1467 } else {
1468 /*
1469 * Called from selinux_complete_init, try to find a dentry.
1470 * Some filesystems really want a connected one, so try
1471 * that first. We could split SECURITY_FS_USE_XATTR in
1472 * two, depending upon that...
1473 */
1474 dentry = d_find_alias(inode);
1475 if (!dentry)
1476 dentry = d_find_any_alias(inode);
1477 }
1478 if (!dentry) {
1479 /*
1480 * this is can be hit on boot when a file is accessed
1481 * before the policy is loaded. When we load policy we
1482 * may find inodes that have no dentry on the
1483 * sbsec->isec_head list. No reason to complain as these
1484 * will get fixed up the next time we go through
1485 * inode_doinit with a dentry, before these inodes could
1486 * be used again by userspace.
1487 */
1488 goto out_invalid;
1489 }
1490
1491 rc = inode_doinit_use_xattr(inode, dentry, sbsec->def_sid,
1492 &sid);
1493 dput(dentry);
1494 if (rc)
1495 goto out;
1496 break;
1497 case SECURITY_FS_USE_TASK:
1498 sid = task_sid;
1499 break;
1500 case SECURITY_FS_USE_TRANS:
1501 /* Default to the fs SID. */
1502 sid = sbsec->sid;
1503
1504 /* Try to obtain a transition SID. */
1505 rc = security_transition_sid(task_sid, sid,
1506 sclass, NULL, &sid);
1507 if (rc)
1508 goto out;
1509 break;
1510 case SECURITY_FS_USE_MNTPOINT:
1511 sid = sbsec->mntpoint_sid;
1512 break;
1513 default:
1514 /* Default to the fs superblock SID. */
1515 sid = sbsec->sid;
1516
1517 if ((sbsec->flags & SE_SBGENFS) &&
1518 (!S_ISLNK(inode->i_mode) ||
1519 selinux_policycap_genfs_seclabel_symlinks())) {
1520 /* We must have a dentry to determine the label on
1521 * procfs inodes */
1522 if (opt_dentry) {
1523 /* Called from d_instantiate or
1524 * d_splice_alias. */
1525 dentry = dget(opt_dentry);
1526 } else {
1527 /* Called from selinux_complete_init, try to
1528 * find a dentry. Some filesystems really want
1529 * a connected one, so try that first.
1530 */
1531 dentry = d_find_alias(inode);
1532 if (!dentry)
1533 dentry = d_find_any_alias(inode);
1534 }
1535 /*
1536 * This can be hit on boot when a file is accessed
1537 * before the policy is loaded. When we load policy we
1538 * may find inodes that have no dentry on the
1539 * sbsec->isec_head list. No reason to complain as
1540 * these will get fixed up the next time we go through
1541 * inode_doinit() with a dentry, before these inodes
1542 * could be used again by userspace.
1543 */
1544 if (!dentry)
1545 goto out_invalid;
1546 rc = selinux_genfs_get_sid(dentry, sclass,
1547 sbsec->flags, &sid);
1548 if (rc) {
1549 dput(dentry);
1550 goto out;
1551 }
1552
1553 if ((sbsec->flags & SE_SBGENFS_XATTR) &&
1554 (inode->i_opflags & IOP_XATTR)) {
1555 rc = inode_doinit_use_xattr(inode, dentry,
1556 sid, &sid);
1557 if (rc) {
1558 dput(dentry);
1559 goto out;
1560 }
1561 }
1562 dput(dentry);
1563 }
1564 break;
1565 }
1566
1567 out:
1568 spin_lock(&isec->lock);
1569 if (isec->initialized == LABEL_PENDING) {
1570 if (rc) {
1571 isec->initialized = LABEL_INVALID;
1572 goto out_unlock;
1573 }
1574 isec->initialized = LABEL_INITIALIZED;
1575 isec->sid = sid;
1576 }
1577
1578 out_unlock:
1579 spin_unlock(&isec->lock);
1580 return rc;
1581
1582 out_invalid:
1583 spin_lock(&isec->lock);
1584 if (isec->initialized == LABEL_PENDING) {
1585 isec->initialized = LABEL_INVALID;
1586 isec->sid = sid;
1587 }
1588 spin_unlock(&isec->lock);
1589 return 0;
1590 }
1591
1592 /* Convert a Linux signal to an access vector. */
signal_to_av(int sig)1593 static inline u32 signal_to_av(int sig)
1594 {
1595 u32 perm = 0;
1596
1597 switch (sig) {
1598 case SIGCHLD:
1599 /* Commonly granted from child to parent. */
1600 perm = PROCESS__SIGCHLD;
1601 break;
1602 case SIGKILL:
1603 /* Cannot be caught or ignored */
1604 perm = PROCESS__SIGKILL;
1605 break;
1606 case SIGSTOP:
1607 /* Cannot be caught or ignored */
1608 perm = PROCESS__SIGSTOP;
1609 break;
1610 default:
1611 /* All other signals. */
1612 perm = PROCESS__SIGNAL;
1613 break;
1614 }
1615
1616 return perm;
1617 }
1618
1619 #if CAP_LAST_CAP > 63
1620 #error Fix SELinux to handle capabilities > 63.
1621 #endif
1622
1623 /* Check whether a task is allowed to use a capability. */
cred_has_capability(const struct cred * cred,int cap,unsigned int opts,bool initns)1624 static int cred_has_capability(const struct cred *cred,
1625 int cap, unsigned int opts, bool initns)
1626 {
1627 struct common_audit_data ad;
1628 struct av_decision avd;
1629 u16 sclass;
1630 u32 sid = cred_sid(cred);
1631 u32 av = CAP_TO_MASK(cap);
1632 int rc;
1633
1634 ad.type = LSM_AUDIT_DATA_CAP;
1635 ad.u.cap = cap;
1636
1637 switch (CAP_TO_INDEX(cap)) {
1638 case 0:
1639 sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1640 break;
1641 case 1:
1642 sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1643 break;
1644 default:
1645 pr_err("SELinux: out of range capability %d\n", cap);
1646 BUG();
1647 return -EINVAL;
1648 }
1649
1650 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1651 if (!(opts & CAP_OPT_NOAUDIT)) {
1652 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1653 if (rc2)
1654 return rc2;
1655 }
1656 return rc;
1657 }
1658
1659 /* Check whether a task has a particular permission to an inode.
1660 The 'adp' parameter is optional and allows other audit
1661 data to be passed (e.g. the dentry). */
inode_has_perm(const struct cred * cred,struct inode * inode,u32 perms,struct common_audit_data * adp)1662 static int inode_has_perm(const struct cred *cred,
1663 struct inode *inode,
1664 u32 perms,
1665 struct common_audit_data *adp)
1666 {
1667 struct inode_security_struct *isec;
1668 u32 sid;
1669
1670 if (unlikely(IS_PRIVATE(inode)))
1671 return 0;
1672
1673 sid = cred_sid(cred);
1674 isec = selinux_inode(inode);
1675
1676 return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1677 }
1678
1679 /* Same as inode_has_perm, but pass explicit audit data containing
1680 the dentry to help the auditing code to more easily generate the
1681 pathname if needed. */
dentry_has_perm(const struct cred * cred,struct dentry * dentry,u32 av)1682 static inline int dentry_has_perm(const struct cred *cred,
1683 struct dentry *dentry,
1684 u32 av)
1685 {
1686 struct inode *inode = d_backing_inode(dentry);
1687 struct common_audit_data ad;
1688
1689 ad.type = LSM_AUDIT_DATA_DENTRY;
1690 ad.u.dentry = dentry;
1691 __inode_security_revalidate(inode, dentry, true);
1692 return inode_has_perm(cred, inode, av, &ad);
1693 }
1694
1695 /* Same as inode_has_perm, but pass explicit audit data containing
1696 the path to help the auditing code to more easily generate the
1697 pathname if needed. */
path_has_perm(const struct cred * cred,const struct path * path,u32 av)1698 static inline int path_has_perm(const struct cred *cred,
1699 const struct path *path,
1700 u32 av)
1701 {
1702 struct inode *inode = d_backing_inode(path->dentry);
1703 struct common_audit_data ad;
1704
1705 ad.type = LSM_AUDIT_DATA_PATH;
1706 ad.u.path = *path;
1707 __inode_security_revalidate(inode, path->dentry, true);
1708 return inode_has_perm(cred, inode, av, &ad);
1709 }
1710
1711 /* Same as path_has_perm, but uses the inode from the file struct. */
file_path_has_perm(const struct cred * cred,struct file * file,u32 av)1712 static inline int file_path_has_perm(const struct cred *cred,
1713 struct file *file,
1714 u32 av)
1715 {
1716 struct common_audit_data ad;
1717
1718 ad.type = LSM_AUDIT_DATA_FILE;
1719 ad.u.file = file;
1720 return inode_has_perm(cred, file_inode(file), av, &ad);
1721 }
1722
1723 #ifdef CONFIG_BPF_SYSCALL
1724 static int bpf_fd_pass(const struct file *file, u32 sid);
1725 #endif
1726
1727 /* Check whether a task can use an open file descriptor to
1728 access an inode in a given way. Check access to the
1729 descriptor itself, and then use dentry_has_perm to
1730 check a particular permission to the file.
1731 Access to the descriptor is implicitly granted if it
1732 has the same SID as the process. If av is zero, then
1733 access to the file is not checked, e.g. for cases
1734 where only the descriptor is affected like seek. */
file_has_perm(const struct cred * cred,struct file * file,u32 av)1735 static int file_has_perm(const struct cred *cred,
1736 struct file *file,
1737 u32 av)
1738 {
1739 struct file_security_struct *fsec = selinux_file(file);
1740 struct inode *inode = file_inode(file);
1741 struct common_audit_data ad;
1742 u32 sid = cred_sid(cred);
1743 int rc;
1744
1745 ad.type = LSM_AUDIT_DATA_FILE;
1746 ad.u.file = file;
1747
1748 if (sid != fsec->sid) {
1749 rc = avc_has_perm(sid, fsec->sid,
1750 SECCLASS_FD,
1751 FD__USE,
1752 &ad);
1753 if (rc)
1754 goto out;
1755 }
1756
1757 #ifdef CONFIG_BPF_SYSCALL
1758 rc = bpf_fd_pass(file, cred_sid(cred));
1759 if (rc)
1760 return rc;
1761 #endif
1762
1763 /* av is zero if only checking access to the descriptor. */
1764 rc = 0;
1765 if (av)
1766 rc = inode_has_perm(cred, inode, av, &ad);
1767
1768 out:
1769 return rc;
1770 }
1771
1772 /*
1773 * Determine the label for an inode that might be unioned.
1774 */
1775 static int
selinux_determine_inode_label(const struct task_security_struct * tsec,struct inode * dir,const struct qstr * name,u16 tclass,u32 * _new_isid)1776 selinux_determine_inode_label(const struct task_security_struct *tsec,
1777 struct inode *dir,
1778 const struct qstr *name, u16 tclass,
1779 u32 *_new_isid)
1780 {
1781 const struct superblock_security_struct *sbsec =
1782 selinux_superblock(dir->i_sb);
1783
1784 if ((sbsec->flags & SE_SBINITIALIZED) &&
1785 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
1786 *_new_isid = sbsec->mntpoint_sid;
1787 } else if ((sbsec->flags & SBLABEL_MNT) &&
1788 tsec->create_sid) {
1789 *_new_isid = tsec->create_sid;
1790 } else {
1791 const struct inode_security_struct *dsec = inode_security(dir);
1792 return security_transition_sid(tsec->sid,
1793 dsec->sid, tclass,
1794 name, _new_isid);
1795 }
1796
1797 return 0;
1798 }
1799
1800 /* Check whether a task can create a file. */
may_create(struct inode * dir,struct dentry * dentry,u16 tclass)1801 static int may_create(struct inode *dir,
1802 struct dentry *dentry,
1803 u16 tclass)
1804 {
1805 const struct task_security_struct *tsec = selinux_cred(current_cred());
1806 struct inode_security_struct *dsec;
1807 struct superblock_security_struct *sbsec;
1808 u32 sid, newsid;
1809 struct common_audit_data ad;
1810 int rc;
1811
1812 dsec = inode_security(dir);
1813 sbsec = selinux_superblock(dir->i_sb);
1814
1815 sid = tsec->sid;
1816
1817 ad.type = LSM_AUDIT_DATA_DENTRY;
1818 ad.u.dentry = dentry;
1819
1820 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1821 DIR__ADD_NAME | DIR__SEARCH,
1822 &ad);
1823 if (rc)
1824 return rc;
1825
1826 rc = selinux_determine_inode_label(tsec, dir, &dentry->d_name, tclass,
1827 &newsid);
1828 if (rc)
1829 return rc;
1830
1831 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1832 if (rc)
1833 return rc;
1834
1835 return avc_has_perm(newsid, sbsec->sid,
1836 SECCLASS_FILESYSTEM,
1837 FILESYSTEM__ASSOCIATE, &ad);
1838 }
1839
1840 #define MAY_LINK 0
1841 #define MAY_UNLINK 1
1842 #define MAY_RMDIR 2
1843
1844 /* Check whether a task can link, unlink, or rmdir a file/directory. */
may_link(struct inode * dir,struct dentry * dentry,int kind)1845 static int may_link(struct inode *dir,
1846 struct dentry *dentry,
1847 int kind)
1848
1849 {
1850 struct inode_security_struct *dsec, *isec;
1851 struct common_audit_data ad;
1852 u32 sid = current_sid();
1853 u32 av;
1854 int rc;
1855
1856 dsec = inode_security(dir);
1857 isec = backing_inode_security(dentry);
1858
1859 ad.type = LSM_AUDIT_DATA_DENTRY;
1860 ad.u.dentry = dentry;
1861
1862 av = DIR__SEARCH;
1863 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1864 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1865 if (rc)
1866 return rc;
1867
1868 switch (kind) {
1869 case MAY_LINK:
1870 av = FILE__LINK;
1871 break;
1872 case MAY_UNLINK:
1873 av = FILE__UNLINK;
1874 break;
1875 case MAY_RMDIR:
1876 av = DIR__RMDIR;
1877 break;
1878 default:
1879 pr_warn("SELinux: %s: unrecognized kind %d\n",
1880 __func__, kind);
1881 return 0;
1882 }
1883
1884 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1885 return rc;
1886 }
1887
may_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)1888 static inline int may_rename(struct inode *old_dir,
1889 struct dentry *old_dentry,
1890 struct inode *new_dir,
1891 struct dentry *new_dentry)
1892 {
1893 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1894 struct common_audit_data ad;
1895 u32 sid = current_sid();
1896 u32 av;
1897 int old_is_dir, new_is_dir;
1898 int rc;
1899
1900 old_dsec = inode_security(old_dir);
1901 old_isec = backing_inode_security(old_dentry);
1902 old_is_dir = d_is_dir(old_dentry);
1903 new_dsec = inode_security(new_dir);
1904
1905 ad.type = LSM_AUDIT_DATA_DENTRY;
1906
1907 ad.u.dentry = old_dentry;
1908 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1909 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1910 if (rc)
1911 return rc;
1912 rc = avc_has_perm(sid, old_isec->sid,
1913 old_isec->sclass, FILE__RENAME, &ad);
1914 if (rc)
1915 return rc;
1916 if (old_is_dir && new_dir != old_dir) {
1917 rc = avc_has_perm(sid, old_isec->sid,
1918 old_isec->sclass, DIR__REPARENT, &ad);
1919 if (rc)
1920 return rc;
1921 }
1922
1923 ad.u.dentry = new_dentry;
1924 av = DIR__ADD_NAME | DIR__SEARCH;
1925 if (d_is_positive(new_dentry))
1926 av |= DIR__REMOVE_NAME;
1927 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1928 if (rc)
1929 return rc;
1930 if (d_is_positive(new_dentry)) {
1931 new_isec = backing_inode_security(new_dentry);
1932 new_is_dir = d_is_dir(new_dentry);
1933 rc = avc_has_perm(sid, new_isec->sid,
1934 new_isec->sclass,
1935 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1936 if (rc)
1937 return rc;
1938 }
1939
1940 return 0;
1941 }
1942
1943 /* Check whether a task can perform a filesystem operation. */
superblock_has_perm(const struct cred * cred,const struct super_block * sb,u32 perms,struct common_audit_data * ad)1944 static int superblock_has_perm(const struct cred *cred,
1945 const struct super_block *sb,
1946 u32 perms,
1947 struct common_audit_data *ad)
1948 {
1949 struct superblock_security_struct *sbsec;
1950 u32 sid = cred_sid(cred);
1951
1952 sbsec = selinux_superblock(sb);
1953 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1954 }
1955
1956 /* Convert a Linux mode and permission mask to an access vector. */
file_mask_to_av(int mode,int mask)1957 static inline u32 file_mask_to_av(int mode, int mask)
1958 {
1959 u32 av = 0;
1960
1961 if (!S_ISDIR(mode)) {
1962 if (mask & MAY_EXEC)
1963 av |= FILE__EXECUTE;
1964 if (mask & MAY_READ)
1965 av |= FILE__READ;
1966
1967 if (mask & MAY_APPEND)
1968 av |= FILE__APPEND;
1969 else if (mask & MAY_WRITE)
1970 av |= FILE__WRITE;
1971
1972 } else {
1973 if (mask & MAY_EXEC)
1974 av |= DIR__SEARCH;
1975 if (mask & MAY_WRITE)
1976 av |= DIR__WRITE;
1977 if (mask & MAY_READ)
1978 av |= DIR__READ;
1979 }
1980
1981 return av;
1982 }
1983
1984 /* Convert a Linux file to an access vector. */
file_to_av(const struct file * file)1985 static inline u32 file_to_av(const struct file *file)
1986 {
1987 u32 av = 0;
1988
1989 if (file->f_mode & FMODE_READ)
1990 av |= FILE__READ;
1991 if (file->f_mode & FMODE_WRITE) {
1992 if (file->f_flags & O_APPEND)
1993 av |= FILE__APPEND;
1994 else
1995 av |= FILE__WRITE;
1996 }
1997 if (!av) {
1998 /*
1999 * Special file opened with flags 3 for ioctl-only use.
2000 */
2001 av = FILE__IOCTL;
2002 }
2003
2004 return av;
2005 }
2006
2007 /*
2008 * Convert a file to an access vector and include the correct
2009 * open permission.
2010 */
open_file_to_av(struct file * file)2011 static inline u32 open_file_to_av(struct file *file)
2012 {
2013 u32 av = file_to_av(file);
2014 struct inode *inode = file_inode(file);
2015
2016 if (selinux_policycap_openperm() &&
2017 inode->i_sb->s_magic != SOCKFS_MAGIC)
2018 av |= FILE__OPEN;
2019
2020 return av;
2021 }
2022
2023 /* Hook functions begin here. */
2024
selinux_binder_set_context_mgr(const struct cred * mgr)2025 static int selinux_binder_set_context_mgr(const struct cred *mgr)
2026 {
2027 return avc_has_perm(current_sid(), cred_sid(mgr), SECCLASS_BINDER,
2028 BINDER__SET_CONTEXT_MGR, NULL);
2029 }
2030
selinux_binder_transaction(const struct cred * from,const struct cred * to)2031 static int selinux_binder_transaction(const struct cred *from,
2032 const struct cred *to)
2033 {
2034 u32 mysid = current_sid();
2035 u32 fromsid = cred_sid(from);
2036 u32 tosid = cred_sid(to);
2037 int rc;
2038
2039 if (mysid != fromsid) {
2040 rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER,
2041 BINDER__IMPERSONATE, NULL);
2042 if (rc)
2043 return rc;
2044 }
2045
2046 return avc_has_perm(fromsid, tosid,
2047 SECCLASS_BINDER, BINDER__CALL, NULL);
2048 }
2049
selinux_binder_transfer_binder(const struct cred * from,const struct cred * to)2050 static int selinux_binder_transfer_binder(const struct cred *from,
2051 const struct cred *to)
2052 {
2053 return avc_has_perm(cred_sid(from), cred_sid(to),
2054 SECCLASS_BINDER, BINDER__TRANSFER,
2055 NULL);
2056 }
2057
selinux_binder_transfer_file(const struct cred * from,const struct cred * to,const struct file * file)2058 static int selinux_binder_transfer_file(const struct cred *from,
2059 const struct cred *to,
2060 const struct file *file)
2061 {
2062 u32 sid = cred_sid(to);
2063 struct file_security_struct *fsec = selinux_file(file);
2064 struct dentry *dentry = file->f_path.dentry;
2065 struct inode_security_struct *isec;
2066 struct common_audit_data ad;
2067 int rc;
2068
2069 ad.type = LSM_AUDIT_DATA_PATH;
2070 ad.u.path = file->f_path;
2071
2072 if (sid != fsec->sid) {
2073 rc = avc_has_perm(sid, fsec->sid,
2074 SECCLASS_FD,
2075 FD__USE,
2076 &ad);
2077 if (rc)
2078 return rc;
2079 }
2080
2081 #ifdef CONFIG_BPF_SYSCALL
2082 rc = bpf_fd_pass(file, sid);
2083 if (rc)
2084 return rc;
2085 #endif
2086
2087 if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2088 return 0;
2089
2090 isec = backing_inode_security(dentry);
2091 return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
2092 &ad);
2093 }
2094
selinux_ptrace_access_check(struct task_struct * child,unsigned int mode)2095 static int selinux_ptrace_access_check(struct task_struct *child,
2096 unsigned int mode)
2097 {
2098 u32 sid = current_sid();
2099 u32 csid = task_sid_obj(child);
2100
2101 if (mode & PTRACE_MODE_READ)
2102 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ,
2103 NULL);
2104
2105 return avc_has_perm(sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE,
2106 NULL);
2107 }
2108
selinux_ptrace_traceme(struct task_struct * parent)2109 static int selinux_ptrace_traceme(struct task_struct *parent)
2110 {
2111 return avc_has_perm(task_sid_obj(parent), task_sid_obj(current),
2112 SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
2113 }
2114
selinux_capget(const struct task_struct * target,kernel_cap_t * effective,kernel_cap_t * inheritable,kernel_cap_t * permitted)2115 static int selinux_capget(const struct task_struct *target, kernel_cap_t *effective,
2116 kernel_cap_t *inheritable, kernel_cap_t *permitted)
2117 {
2118 return avc_has_perm(current_sid(), task_sid_obj(target),
2119 SECCLASS_PROCESS, PROCESS__GETCAP, NULL);
2120 }
2121
selinux_capset(struct cred * new,const struct cred * old,const kernel_cap_t * effective,const kernel_cap_t * inheritable,const kernel_cap_t * permitted)2122 static int selinux_capset(struct cred *new, const struct cred *old,
2123 const kernel_cap_t *effective,
2124 const kernel_cap_t *inheritable,
2125 const kernel_cap_t *permitted)
2126 {
2127 return avc_has_perm(cred_sid(old), cred_sid(new), SECCLASS_PROCESS,
2128 PROCESS__SETCAP, NULL);
2129 }
2130
2131 /*
2132 * (This comment used to live with the selinux_task_setuid hook,
2133 * which was removed).
2134 *
2135 * Since setuid only affects the current process, and since the SELinux
2136 * controls are not based on the Linux identity attributes, SELinux does not
2137 * need to control this operation. However, SELinux does control the use of
2138 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
2139 */
2140
selinux_capable(const struct cred * cred,struct user_namespace * ns,int cap,unsigned int opts)2141 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
2142 int cap, unsigned int opts)
2143 {
2144 return cred_has_capability(cred, cap, opts, ns == &init_user_ns);
2145 }
2146
selinux_quotactl(int cmds,int type,int id,const struct super_block * sb)2147 static int selinux_quotactl(int cmds, int type, int id, const struct super_block *sb)
2148 {
2149 const struct cred *cred = current_cred();
2150 int rc = 0;
2151
2152 if (!sb)
2153 return 0;
2154
2155 switch (cmds) {
2156 case Q_SYNC:
2157 case Q_QUOTAON:
2158 case Q_QUOTAOFF:
2159 case Q_SETINFO:
2160 case Q_SETQUOTA:
2161 case Q_XQUOTAOFF:
2162 case Q_XQUOTAON:
2163 case Q_XSETQLIM:
2164 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2165 break;
2166 case Q_GETFMT:
2167 case Q_GETINFO:
2168 case Q_GETQUOTA:
2169 case Q_XGETQUOTA:
2170 case Q_XGETQSTAT:
2171 case Q_XGETQSTATV:
2172 case Q_XGETNEXTQUOTA:
2173 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2174 break;
2175 default:
2176 rc = 0; /* let the kernel handle invalid cmds */
2177 break;
2178 }
2179 return rc;
2180 }
2181
selinux_quota_on(struct dentry * dentry)2182 static int selinux_quota_on(struct dentry *dentry)
2183 {
2184 const struct cred *cred = current_cred();
2185
2186 return dentry_has_perm(cred, dentry, FILE__QUOTAON);
2187 }
2188
selinux_syslog(int type)2189 static int selinux_syslog(int type)
2190 {
2191 switch (type) {
2192 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
2193 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
2194 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2195 SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL);
2196 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
2197 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */
2198 /* Set level of messages printed to console */
2199 case SYSLOG_ACTION_CONSOLE_LEVEL:
2200 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2201 SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE,
2202 NULL);
2203 }
2204 /* All other syslog types */
2205 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2206 SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL);
2207 }
2208
2209 /*
2210 * Check permission for allocating a new virtual mapping. Returns
2211 * 0 if permission is granted, negative error code if not.
2212 *
2213 * Do not audit the selinux permission check, as this is applied to all
2214 * processes that allocate mappings.
2215 */
selinux_vm_enough_memory(struct mm_struct * mm,long pages)2216 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2217 {
2218 return cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2219 CAP_OPT_NOAUDIT, true);
2220 }
2221
2222 /* binprm security operations */
2223
ptrace_parent_sid(void)2224 static u32 ptrace_parent_sid(void)
2225 {
2226 u32 sid = 0;
2227 struct task_struct *tracer;
2228
2229 rcu_read_lock();
2230 tracer = ptrace_parent(current);
2231 if (tracer)
2232 sid = task_sid_obj(tracer);
2233 rcu_read_unlock();
2234
2235 return sid;
2236 }
2237
check_nnp_nosuid(const struct linux_binprm * bprm,const struct task_security_struct * old_tsec,const struct task_security_struct * new_tsec)2238 static int check_nnp_nosuid(const struct linux_binprm *bprm,
2239 const struct task_security_struct *old_tsec,
2240 const struct task_security_struct *new_tsec)
2241 {
2242 int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2243 int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2244 int rc;
2245 u32 av;
2246
2247 if (!nnp && !nosuid)
2248 return 0; /* neither NNP nor nosuid */
2249
2250 if (new_tsec->sid == old_tsec->sid)
2251 return 0; /* No change in credentials */
2252
2253 /*
2254 * If the policy enables the nnp_nosuid_transition policy capability,
2255 * then we permit transitions under NNP or nosuid if the
2256 * policy allows the corresponding permission between
2257 * the old and new contexts.
2258 */
2259 if (selinux_policycap_nnp_nosuid_transition()) {
2260 av = 0;
2261 if (nnp)
2262 av |= PROCESS2__NNP_TRANSITION;
2263 if (nosuid)
2264 av |= PROCESS2__NOSUID_TRANSITION;
2265 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2266 SECCLASS_PROCESS2, av, NULL);
2267 if (!rc)
2268 return 0;
2269 }
2270
2271 /*
2272 * We also permit NNP or nosuid transitions to bounded SIDs,
2273 * i.e. SIDs that are guaranteed to only be allowed a subset
2274 * of the permissions of the current SID.
2275 */
2276 rc = security_bounded_transition(old_tsec->sid,
2277 new_tsec->sid);
2278 if (!rc)
2279 return 0;
2280
2281 /*
2282 * On failure, preserve the errno values for NNP vs nosuid.
2283 * NNP: Operation not permitted for caller.
2284 * nosuid: Permission denied to file.
2285 */
2286 if (nnp)
2287 return -EPERM;
2288 return -EACCES;
2289 }
2290
selinux_bprm_creds_for_exec(struct linux_binprm * bprm)2291 static int selinux_bprm_creds_for_exec(struct linux_binprm *bprm)
2292 {
2293 const struct task_security_struct *old_tsec;
2294 struct task_security_struct *new_tsec;
2295 struct inode_security_struct *isec;
2296 struct common_audit_data ad;
2297 struct inode *inode = file_inode(bprm->file);
2298 int rc;
2299
2300 /* SELinux context only depends on initial program or script and not
2301 * the script interpreter */
2302
2303 old_tsec = selinux_cred(current_cred());
2304 new_tsec = selinux_cred(bprm->cred);
2305 isec = inode_security(inode);
2306
2307 /* Default to the current task SID. */
2308 new_tsec->sid = old_tsec->sid;
2309 new_tsec->osid = old_tsec->sid;
2310
2311 /* Reset fs, key, and sock SIDs on execve. */
2312 new_tsec->create_sid = 0;
2313 new_tsec->keycreate_sid = 0;
2314 new_tsec->sockcreate_sid = 0;
2315
2316 /*
2317 * Before policy is loaded, label any task outside kernel space
2318 * as SECINITSID_INIT, so that any userspace tasks surviving from
2319 * early boot end up with a label different from SECINITSID_KERNEL
2320 * (if the policy chooses to set SECINITSID_INIT != SECINITSID_KERNEL).
2321 */
2322 if (!selinux_initialized()) {
2323 new_tsec->sid = SECINITSID_INIT;
2324 /* also clear the exec_sid just in case */
2325 new_tsec->exec_sid = 0;
2326 return 0;
2327 }
2328
2329 if (old_tsec->exec_sid) {
2330 new_tsec->sid = old_tsec->exec_sid;
2331 /* Reset exec SID on execve. */
2332 new_tsec->exec_sid = 0;
2333
2334 /* Fail on NNP or nosuid if not an allowed transition. */
2335 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2336 if (rc)
2337 return rc;
2338 } else {
2339 /* Check for a default transition on this program. */
2340 rc = security_transition_sid(old_tsec->sid,
2341 isec->sid, SECCLASS_PROCESS, NULL,
2342 &new_tsec->sid);
2343 if (rc)
2344 return rc;
2345
2346 /*
2347 * Fallback to old SID on NNP or nosuid if not an allowed
2348 * transition.
2349 */
2350 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2351 if (rc)
2352 new_tsec->sid = old_tsec->sid;
2353 }
2354
2355 ad.type = LSM_AUDIT_DATA_FILE;
2356 ad.u.file = bprm->file;
2357
2358 if (new_tsec->sid == old_tsec->sid) {
2359 rc = avc_has_perm(old_tsec->sid, isec->sid,
2360 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2361 if (rc)
2362 return rc;
2363 } else {
2364 /* Check permissions for the transition. */
2365 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2366 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2367 if (rc)
2368 return rc;
2369
2370 rc = avc_has_perm(new_tsec->sid, isec->sid,
2371 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2372 if (rc)
2373 return rc;
2374
2375 /* Check for shared state */
2376 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2377 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2378 SECCLASS_PROCESS, PROCESS__SHARE,
2379 NULL);
2380 if (rc)
2381 return -EPERM;
2382 }
2383
2384 /* Make sure that anyone attempting to ptrace over a task that
2385 * changes its SID has the appropriate permit */
2386 if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
2387 u32 ptsid = ptrace_parent_sid();
2388 if (ptsid != 0) {
2389 rc = avc_has_perm(ptsid, new_tsec->sid,
2390 SECCLASS_PROCESS,
2391 PROCESS__PTRACE, NULL);
2392 if (rc)
2393 return -EPERM;
2394 }
2395 }
2396
2397 /* Clear any possibly unsafe personality bits on exec: */
2398 bprm->per_clear |= PER_CLEAR_ON_SETID;
2399
2400 /* Enable secure mode for SIDs transitions unless
2401 the noatsecure permission is granted between
2402 the two SIDs, i.e. ahp returns 0. */
2403 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2404 SECCLASS_PROCESS, PROCESS__NOATSECURE,
2405 NULL);
2406 bprm->secureexec |= !!rc;
2407 }
2408
2409 return 0;
2410 }
2411
match_file(const void * p,struct file * file,unsigned fd)2412 static int match_file(const void *p, struct file *file, unsigned fd)
2413 {
2414 return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
2415 }
2416
2417 /* Derived from fs/exec.c:flush_old_files. */
flush_unauthorized_files(const struct cred * cred,struct files_struct * files)2418 static inline void flush_unauthorized_files(const struct cred *cred,
2419 struct files_struct *files)
2420 {
2421 struct file *file, *devnull = NULL;
2422 struct tty_struct *tty;
2423 int drop_tty = 0;
2424 unsigned n;
2425
2426 tty = get_current_tty();
2427 if (tty) {
2428 spin_lock(&tty->files_lock);
2429 if (!list_empty(&tty->tty_files)) {
2430 struct tty_file_private *file_priv;
2431
2432 /* Revalidate access to controlling tty.
2433 Use file_path_has_perm on the tty path directly
2434 rather than using file_has_perm, as this particular
2435 open file may belong to another process and we are
2436 only interested in the inode-based check here. */
2437 file_priv = list_first_entry(&tty->tty_files,
2438 struct tty_file_private, list);
2439 file = file_priv->file;
2440 if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2441 drop_tty = 1;
2442 }
2443 spin_unlock(&tty->files_lock);
2444 tty_kref_put(tty);
2445 }
2446 /* Reset controlling tty. */
2447 if (drop_tty)
2448 no_tty();
2449
2450 /* Revalidate access to inherited open files. */
2451 n = iterate_fd(files, 0, match_file, cred);
2452 if (!n) /* none found? */
2453 return;
2454
2455 devnull = dentry_open(&selinux_null, O_RDWR, cred);
2456 if (IS_ERR(devnull))
2457 devnull = NULL;
2458 /* replace all the matching ones with this */
2459 do {
2460 replace_fd(n - 1, devnull, 0);
2461 } while ((n = iterate_fd(files, n, match_file, cred)) != 0);
2462 if (devnull)
2463 fput(devnull);
2464 }
2465
2466 /*
2467 * Prepare a process for imminent new credential changes due to exec
2468 */
selinux_bprm_committing_creds(const struct linux_binprm * bprm)2469 static void selinux_bprm_committing_creds(const struct linux_binprm *bprm)
2470 {
2471 struct task_security_struct *new_tsec;
2472 struct rlimit *rlim, *initrlim;
2473 int rc, i;
2474
2475 new_tsec = selinux_cred(bprm->cred);
2476 if (new_tsec->sid == new_tsec->osid)
2477 return;
2478
2479 /* Close files for which the new task SID is not authorized. */
2480 flush_unauthorized_files(bprm->cred, current->files);
2481
2482 /* Always clear parent death signal on SID transitions. */
2483 current->pdeath_signal = 0;
2484
2485 /* Check whether the new SID can inherit resource limits from the old
2486 * SID. If not, reset all soft limits to the lower of the current
2487 * task's hard limit and the init task's soft limit.
2488 *
2489 * Note that the setting of hard limits (even to lower them) can be
2490 * controlled by the setrlimit check. The inclusion of the init task's
2491 * soft limit into the computation is to avoid resetting soft limits
2492 * higher than the default soft limit for cases where the default is
2493 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2494 */
2495 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2496 PROCESS__RLIMITINH, NULL);
2497 if (rc) {
2498 /* protect against do_prlimit() */
2499 task_lock(current);
2500 for (i = 0; i < RLIM_NLIMITS; i++) {
2501 rlim = current->signal->rlim + i;
2502 initrlim = init_task.signal->rlim + i;
2503 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2504 }
2505 task_unlock(current);
2506 if (IS_ENABLED(CONFIG_POSIX_TIMERS))
2507 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2508 }
2509 }
2510
2511 /*
2512 * Clean up the process immediately after the installation of new credentials
2513 * due to exec
2514 */
selinux_bprm_committed_creds(const struct linux_binprm * bprm)2515 static void selinux_bprm_committed_creds(const struct linux_binprm *bprm)
2516 {
2517 const struct task_security_struct *tsec = selinux_cred(current_cred());
2518 u32 osid, sid;
2519 int rc;
2520
2521 osid = tsec->osid;
2522 sid = tsec->sid;
2523
2524 if (sid == osid)
2525 return;
2526
2527 /* Check whether the new SID can inherit signal state from the old SID.
2528 * If not, clear itimers to avoid subsequent signal generation and
2529 * flush and unblock signals.
2530 *
2531 * This must occur _after_ the task SID has been updated so that any
2532 * kill done after the flush will be checked against the new SID.
2533 */
2534 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2535 if (rc) {
2536 clear_itimer();
2537
2538 spin_lock_irq(&unrcu_pointer(current->sighand)->siglock);
2539 if (!fatal_signal_pending(current)) {
2540 flush_sigqueue(¤t->pending);
2541 flush_sigqueue(¤t->signal->shared_pending);
2542 flush_signal_handlers(current, 1);
2543 sigemptyset(¤t->blocked);
2544 recalc_sigpending();
2545 }
2546 spin_unlock_irq(&unrcu_pointer(current->sighand)->siglock);
2547 }
2548
2549 /* Wake up the parent if it is waiting so that it can recheck
2550 * wait permission to the new task SID. */
2551 read_lock(&tasklist_lock);
2552 __wake_up_parent(current, unrcu_pointer(current->real_parent));
2553 read_unlock(&tasklist_lock);
2554 }
2555
2556 /* superblock security operations */
2557
selinux_sb_alloc_security(struct super_block * sb)2558 static int selinux_sb_alloc_security(struct super_block *sb)
2559 {
2560 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2561
2562 mutex_init(&sbsec->lock);
2563 INIT_LIST_HEAD(&sbsec->isec_head);
2564 spin_lock_init(&sbsec->isec_lock);
2565 sbsec->sid = SECINITSID_UNLABELED;
2566 sbsec->def_sid = SECINITSID_FILE;
2567 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
2568
2569 return 0;
2570 }
2571
opt_len(const char * s)2572 static inline int opt_len(const char *s)
2573 {
2574 bool open_quote = false;
2575 int len;
2576 char c;
2577
2578 for (len = 0; (c = s[len]) != '\0'; len++) {
2579 if (c == '"')
2580 open_quote = !open_quote;
2581 if (c == ',' && !open_quote)
2582 break;
2583 }
2584 return len;
2585 }
2586
selinux_sb_eat_lsm_opts(char * options,void ** mnt_opts)2587 static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
2588 {
2589 char *from = options;
2590 char *to = options;
2591 bool first = true;
2592 int rc;
2593
2594 while (1) {
2595 int len = opt_len(from);
2596 int token;
2597 char *arg = NULL;
2598
2599 token = match_opt_prefix(from, len, &arg);
2600
2601 if (token != Opt_error) {
2602 char *p, *q;
2603
2604 /* strip quotes */
2605 if (arg) {
2606 for (p = q = arg; p < from + len; p++) {
2607 char c = *p;
2608 if (c != '"')
2609 *q++ = c;
2610 }
2611 arg = kmemdup_nul(arg, q - arg, GFP_KERNEL);
2612 if (!arg) {
2613 rc = -ENOMEM;
2614 goto free_opt;
2615 }
2616 }
2617 rc = selinux_add_opt(token, arg, mnt_opts);
2618 kfree(arg);
2619 arg = NULL;
2620 if (unlikely(rc)) {
2621 goto free_opt;
2622 }
2623 } else {
2624 if (!first) { // copy with preceding comma
2625 from--;
2626 len++;
2627 }
2628 if (to != from)
2629 memmove(to, from, len);
2630 to += len;
2631 first = false;
2632 }
2633 if (!from[len])
2634 break;
2635 from += len + 1;
2636 }
2637 *to = '\0';
2638 return 0;
2639
2640 free_opt:
2641 if (*mnt_opts) {
2642 selinux_free_mnt_opts(*mnt_opts);
2643 *mnt_opts = NULL;
2644 }
2645 return rc;
2646 }
2647
selinux_sb_mnt_opts_compat(struct super_block * sb,void * mnt_opts)2648 static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
2649 {
2650 struct selinux_mnt_opts *opts = mnt_opts;
2651 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2652
2653 /*
2654 * Superblock not initialized (i.e. no options) - reject if any
2655 * options specified, otherwise accept.
2656 */
2657 if (!(sbsec->flags & SE_SBINITIALIZED))
2658 return opts ? 1 : 0;
2659
2660 /*
2661 * Superblock initialized and no options specified - reject if
2662 * superblock has any options set, otherwise accept.
2663 */
2664 if (!opts)
2665 return (sbsec->flags & SE_MNTMASK) ? 1 : 0;
2666
2667 if (opts->fscontext_sid) {
2668 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2669 opts->fscontext_sid))
2670 return 1;
2671 }
2672 if (opts->context_sid) {
2673 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2674 opts->context_sid))
2675 return 1;
2676 }
2677 if (opts->rootcontext_sid) {
2678 struct inode_security_struct *root_isec;
2679
2680 root_isec = backing_inode_security(sb->s_root);
2681 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2682 opts->rootcontext_sid))
2683 return 1;
2684 }
2685 if (opts->defcontext_sid) {
2686 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2687 opts->defcontext_sid))
2688 return 1;
2689 }
2690 return 0;
2691 }
2692
selinux_sb_remount(struct super_block * sb,void * mnt_opts)2693 static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
2694 {
2695 struct selinux_mnt_opts *opts = mnt_opts;
2696 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2697
2698 if (!(sbsec->flags & SE_SBINITIALIZED))
2699 return 0;
2700
2701 if (!opts)
2702 return 0;
2703
2704 if (opts->fscontext_sid) {
2705 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2706 opts->fscontext_sid))
2707 goto out_bad_option;
2708 }
2709 if (opts->context_sid) {
2710 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2711 opts->context_sid))
2712 goto out_bad_option;
2713 }
2714 if (opts->rootcontext_sid) {
2715 struct inode_security_struct *root_isec;
2716 root_isec = backing_inode_security(sb->s_root);
2717 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2718 opts->rootcontext_sid))
2719 goto out_bad_option;
2720 }
2721 if (opts->defcontext_sid) {
2722 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2723 opts->defcontext_sid))
2724 goto out_bad_option;
2725 }
2726 return 0;
2727
2728 out_bad_option:
2729 pr_warn("SELinux: unable to change security options "
2730 "during remount (dev %s, type=%s)\n", sb->s_id,
2731 sb->s_type->name);
2732 return -EINVAL;
2733 }
2734
selinux_sb_kern_mount(const struct super_block * sb)2735 static int selinux_sb_kern_mount(const struct super_block *sb)
2736 {
2737 const struct cred *cred = current_cred();
2738 struct common_audit_data ad;
2739
2740 ad.type = LSM_AUDIT_DATA_DENTRY;
2741 ad.u.dentry = sb->s_root;
2742 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2743 }
2744
selinux_sb_statfs(struct dentry * dentry)2745 static int selinux_sb_statfs(struct dentry *dentry)
2746 {
2747 const struct cred *cred = current_cred();
2748 struct common_audit_data ad;
2749
2750 ad.type = LSM_AUDIT_DATA_DENTRY;
2751 ad.u.dentry = dentry->d_sb->s_root;
2752 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2753 }
2754
selinux_mount(const char * dev_name,const struct path * path,const char * type,unsigned long flags,void * data)2755 static int selinux_mount(const char *dev_name,
2756 const struct path *path,
2757 const char *type,
2758 unsigned long flags,
2759 void *data)
2760 {
2761 const struct cred *cred = current_cred();
2762
2763 if (flags & MS_REMOUNT)
2764 return superblock_has_perm(cred, path->dentry->d_sb,
2765 FILESYSTEM__REMOUNT, NULL);
2766 else
2767 return path_has_perm(cred, path, FILE__MOUNTON);
2768 }
2769
selinux_move_mount(const struct path * from_path,const struct path * to_path)2770 static int selinux_move_mount(const struct path *from_path,
2771 const struct path *to_path)
2772 {
2773 const struct cred *cred = current_cred();
2774
2775 return path_has_perm(cred, to_path, FILE__MOUNTON);
2776 }
2777
selinux_umount(struct vfsmount * mnt,int flags)2778 static int selinux_umount(struct vfsmount *mnt, int flags)
2779 {
2780 const struct cred *cred = current_cred();
2781
2782 return superblock_has_perm(cred, mnt->mnt_sb,
2783 FILESYSTEM__UNMOUNT, NULL);
2784 }
2785
selinux_fs_context_submount(struct fs_context * fc,struct super_block * reference)2786 static int selinux_fs_context_submount(struct fs_context *fc,
2787 struct super_block *reference)
2788 {
2789 const struct superblock_security_struct *sbsec = selinux_superblock(reference);
2790 struct selinux_mnt_opts *opts;
2791
2792 /*
2793 * Ensure that fc->security remains NULL when no options are set
2794 * as expected by selinux_set_mnt_opts().
2795 */
2796 if (!(sbsec->flags & (FSCONTEXT_MNT|CONTEXT_MNT|DEFCONTEXT_MNT)))
2797 return 0;
2798
2799 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
2800 if (!opts)
2801 return -ENOMEM;
2802
2803 if (sbsec->flags & FSCONTEXT_MNT)
2804 opts->fscontext_sid = sbsec->sid;
2805 if (sbsec->flags & CONTEXT_MNT)
2806 opts->context_sid = sbsec->mntpoint_sid;
2807 if (sbsec->flags & DEFCONTEXT_MNT)
2808 opts->defcontext_sid = sbsec->def_sid;
2809 fc->security = opts;
2810 return 0;
2811 }
2812
selinux_fs_context_dup(struct fs_context * fc,struct fs_context * src_fc)2813 static int selinux_fs_context_dup(struct fs_context *fc,
2814 struct fs_context *src_fc)
2815 {
2816 const struct selinux_mnt_opts *src = src_fc->security;
2817
2818 if (!src)
2819 return 0;
2820
2821 fc->security = kmemdup(src, sizeof(*src), GFP_KERNEL);
2822 return fc->security ? 0 : -ENOMEM;
2823 }
2824
2825 static const struct fs_parameter_spec selinux_fs_parameters[] = {
2826 fsparam_string(CONTEXT_STR, Opt_context),
2827 fsparam_string(DEFCONTEXT_STR, Opt_defcontext),
2828 fsparam_string(FSCONTEXT_STR, Opt_fscontext),
2829 fsparam_string(ROOTCONTEXT_STR, Opt_rootcontext),
2830 fsparam_flag (SECLABEL_STR, Opt_seclabel),
2831 {}
2832 };
2833
selinux_fs_context_parse_param(struct fs_context * fc,struct fs_parameter * param)2834 static int selinux_fs_context_parse_param(struct fs_context *fc,
2835 struct fs_parameter *param)
2836 {
2837 struct fs_parse_result result;
2838 int opt;
2839
2840 opt = fs_parse(fc, selinux_fs_parameters, param, &result);
2841 if (opt < 0)
2842 return opt;
2843
2844 return selinux_add_opt(opt, param->string, &fc->security);
2845 }
2846
2847 /* inode security operations */
2848
selinux_inode_alloc_security(struct inode * inode)2849 static int selinux_inode_alloc_security(struct inode *inode)
2850 {
2851 struct inode_security_struct *isec = selinux_inode(inode);
2852 u32 sid = current_sid();
2853
2854 spin_lock_init(&isec->lock);
2855 INIT_LIST_HEAD(&isec->list);
2856 isec->inode = inode;
2857 isec->sid = SECINITSID_UNLABELED;
2858 isec->sclass = SECCLASS_FILE;
2859 isec->task_sid = sid;
2860 isec->initialized = LABEL_INVALID;
2861
2862 return 0;
2863 }
2864
selinux_inode_free_security(struct inode * inode)2865 static void selinux_inode_free_security(struct inode *inode)
2866 {
2867 inode_free_security(inode);
2868 }
2869
selinux_dentry_init_security(struct dentry * dentry,int mode,const struct qstr * name,const char ** xattr_name,void ** ctx,u32 * ctxlen)2870 static int selinux_dentry_init_security(struct dentry *dentry, int mode,
2871 const struct qstr *name,
2872 const char **xattr_name, void **ctx,
2873 u32 *ctxlen)
2874 {
2875 u32 newsid;
2876 int rc;
2877
2878 rc = selinux_determine_inode_label(selinux_cred(current_cred()),
2879 d_inode(dentry->d_parent), name,
2880 inode_mode_to_security_class(mode),
2881 &newsid);
2882 if (rc)
2883 return rc;
2884
2885 if (xattr_name)
2886 *xattr_name = XATTR_NAME_SELINUX;
2887
2888 return security_sid_to_context(newsid, (char **)ctx,
2889 ctxlen);
2890 }
2891
selinux_dentry_create_files_as(struct dentry * dentry,int mode,struct qstr * name,const struct cred * old,struct cred * new)2892 static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
2893 struct qstr *name,
2894 const struct cred *old,
2895 struct cred *new)
2896 {
2897 u32 newsid;
2898 int rc;
2899 struct task_security_struct *tsec;
2900
2901 rc = selinux_determine_inode_label(selinux_cred(old),
2902 d_inode(dentry->d_parent), name,
2903 inode_mode_to_security_class(mode),
2904 &newsid);
2905 if (rc)
2906 return rc;
2907
2908 tsec = selinux_cred(new);
2909 tsec->create_sid = newsid;
2910 return 0;
2911 }
2912
selinux_inode_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr,struct xattr * xattrs,int * xattr_count)2913 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2914 const struct qstr *qstr,
2915 struct xattr *xattrs, int *xattr_count)
2916 {
2917 const struct task_security_struct *tsec = selinux_cred(current_cred());
2918 struct superblock_security_struct *sbsec;
2919 struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count);
2920 u32 newsid, clen;
2921 u16 newsclass;
2922 int rc;
2923 char *context;
2924
2925 sbsec = selinux_superblock(dir->i_sb);
2926
2927 newsid = tsec->create_sid;
2928 newsclass = inode_mode_to_security_class(inode->i_mode);
2929 rc = selinux_determine_inode_label(tsec, dir, qstr, newsclass, &newsid);
2930 if (rc)
2931 return rc;
2932
2933 /* Possibly defer initialization to selinux_complete_init. */
2934 if (sbsec->flags & SE_SBINITIALIZED) {
2935 struct inode_security_struct *isec = selinux_inode(inode);
2936 isec->sclass = newsclass;
2937 isec->sid = newsid;
2938 isec->initialized = LABEL_INITIALIZED;
2939 }
2940
2941 if (!selinux_initialized() ||
2942 !(sbsec->flags & SBLABEL_MNT))
2943 return -EOPNOTSUPP;
2944
2945 if (xattr) {
2946 rc = security_sid_to_context_force(newsid,
2947 &context, &clen);
2948 if (rc)
2949 return rc;
2950 xattr->value = context;
2951 xattr->value_len = clen;
2952 xattr->name = XATTR_SELINUX_SUFFIX;
2953 }
2954
2955 return 0;
2956 }
2957
selinux_inode_init_security_anon(struct inode * inode,const struct qstr * name,const struct inode * context_inode)2958 static int selinux_inode_init_security_anon(struct inode *inode,
2959 const struct qstr *name,
2960 const struct inode *context_inode)
2961 {
2962 u32 sid = current_sid();
2963 struct common_audit_data ad;
2964 struct inode_security_struct *isec;
2965 int rc;
2966
2967 if (unlikely(!selinux_initialized()))
2968 return 0;
2969
2970 isec = selinux_inode(inode);
2971
2972 /*
2973 * We only get here once per ephemeral inode. The inode has
2974 * been initialized via inode_alloc_security but is otherwise
2975 * untouched.
2976 */
2977
2978 if (context_inode) {
2979 struct inode_security_struct *context_isec =
2980 selinux_inode(context_inode);
2981 if (context_isec->initialized != LABEL_INITIALIZED) {
2982 pr_err("SELinux: context_inode is not initialized\n");
2983 return -EACCES;
2984 }
2985
2986 isec->sclass = context_isec->sclass;
2987 isec->sid = context_isec->sid;
2988 } else {
2989 isec->sclass = SECCLASS_ANON_INODE;
2990 rc = security_transition_sid(
2991 sid, sid,
2992 isec->sclass, name, &isec->sid);
2993 if (rc)
2994 return rc;
2995 }
2996
2997 isec->initialized = LABEL_INITIALIZED;
2998 /*
2999 * Now that we've initialized security, check whether we're
3000 * allowed to actually create this type of anonymous inode.
3001 */
3002
3003 ad.type = LSM_AUDIT_DATA_ANONINODE;
3004 ad.u.anonclass = name ? (const char *)name->name : "?";
3005
3006 return avc_has_perm(sid,
3007 isec->sid,
3008 isec->sclass,
3009 FILE__CREATE,
3010 &ad);
3011 }
3012
selinux_inode_create(struct inode * dir,struct dentry * dentry,umode_t mode)3013 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
3014 {
3015 return may_create(dir, dentry, SECCLASS_FILE);
3016 }
3017
selinux_inode_link(struct dentry * old_dentry,struct inode * dir,struct dentry * new_dentry)3018 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
3019 {
3020 return may_link(dir, old_dentry, MAY_LINK);
3021 }
3022
selinux_inode_unlink(struct inode * dir,struct dentry * dentry)3023 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
3024 {
3025 return may_link(dir, dentry, MAY_UNLINK);
3026 }
3027
selinux_inode_symlink(struct inode * dir,struct dentry * dentry,const char * name)3028 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
3029 {
3030 return may_create(dir, dentry, SECCLASS_LNK_FILE);
3031 }
3032
selinux_inode_mkdir(struct inode * dir,struct dentry * dentry,umode_t mask)3033 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
3034 {
3035 return may_create(dir, dentry, SECCLASS_DIR);
3036 }
3037
selinux_inode_rmdir(struct inode * dir,struct dentry * dentry)3038 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
3039 {
3040 return may_link(dir, dentry, MAY_RMDIR);
3041 }
3042
selinux_inode_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t dev)3043 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
3044 {
3045 return may_create(dir, dentry, inode_mode_to_security_class(mode));
3046 }
3047
selinux_inode_rename(struct inode * old_inode,struct dentry * old_dentry,struct inode * new_inode,struct dentry * new_dentry)3048 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
3049 struct inode *new_inode, struct dentry *new_dentry)
3050 {
3051 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
3052 }
3053
selinux_inode_readlink(struct dentry * dentry)3054 static int selinux_inode_readlink(struct dentry *dentry)
3055 {
3056 const struct cred *cred = current_cred();
3057
3058 return dentry_has_perm(cred, dentry, FILE__READ);
3059 }
3060
selinux_inode_follow_link(struct dentry * dentry,struct inode * inode,bool rcu)3061 static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
3062 bool rcu)
3063 {
3064 struct common_audit_data ad;
3065 struct inode_security_struct *isec;
3066 u32 sid = current_sid();
3067
3068 ad.type = LSM_AUDIT_DATA_DENTRY;
3069 ad.u.dentry = dentry;
3070 isec = inode_security_rcu(inode, rcu);
3071 if (IS_ERR(isec))
3072 return PTR_ERR(isec);
3073
3074 return avc_has_perm(sid, isec->sid, isec->sclass, FILE__READ, &ad);
3075 }
3076
audit_inode_permission(struct inode * inode,u32 perms,u32 audited,u32 denied,int result)3077 static noinline int audit_inode_permission(struct inode *inode,
3078 u32 perms, u32 audited, u32 denied,
3079 int result)
3080 {
3081 struct common_audit_data ad;
3082 struct inode_security_struct *isec = selinux_inode(inode);
3083
3084 ad.type = LSM_AUDIT_DATA_INODE;
3085 ad.u.inode = inode;
3086
3087 return slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
3088 audited, denied, result, &ad);
3089 }
3090
selinux_inode_permission(struct inode * inode,int mask)3091 static int selinux_inode_permission(struct inode *inode, int mask)
3092 {
3093 u32 perms;
3094 bool from_access;
3095 bool no_block = mask & MAY_NOT_BLOCK;
3096 struct inode_security_struct *isec;
3097 u32 sid = current_sid();
3098 struct av_decision avd;
3099 int rc, rc2;
3100 u32 audited, denied;
3101
3102 from_access = mask & MAY_ACCESS;
3103 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
3104
3105 /* No permission to check. Existence test. */
3106 if (!mask)
3107 return 0;
3108
3109 if (unlikely(IS_PRIVATE(inode)))
3110 return 0;
3111
3112 perms = file_mask_to_av(inode->i_mode, mask);
3113
3114 isec = inode_security_rcu(inode, no_block);
3115 if (IS_ERR(isec))
3116 return PTR_ERR(isec);
3117
3118 rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0,
3119 &avd);
3120 audited = avc_audit_required(perms, &avd, rc,
3121 from_access ? FILE__AUDIT_ACCESS : 0,
3122 &denied);
3123 if (likely(!audited))
3124 return rc;
3125
3126 rc2 = audit_inode_permission(inode, perms, audited, denied, rc);
3127 if (rc2)
3128 return rc2;
3129 return rc;
3130 }
3131
selinux_inode_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)3132 static int selinux_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
3133 struct iattr *iattr)
3134 {
3135 const struct cred *cred = current_cred();
3136 struct inode *inode = d_backing_inode(dentry);
3137 unsigned int ia_valid = iattr->ia_valid;
3138 __u32 av = FILE__WRITE;
3139
3140 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
3141 if (ia_valid & ATTR_FORCE) {
3142 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
3143 ATTR_FORCE);
3144 if (!ia_valid)
3145 return 0;
3146 }
3147
3148 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
3149 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
3150 return dentry_has_perm(cred, dentry, FILE__SETATTR);
3151
3152 if (selinux_policycap_openperm() &&
3153 inode->i_sb->s_magic != SOCKFS_MAGIC &&
3154 (ia_valid & ATTR_SIZE) &&
3155 !(ia_valid & ATTR_FILE))
3156 av |= FILE__OPEN;
3157
3158 return dentry_has_perm(cred, dentry, av);
3159 }
3160
selinux_inode_getattr(const struct path * path)3161 static int selinux_inode_getattr(const struct path *path)
3162 {
3163 return path_has_perm(current_cred(), path, FILE__GETATTR);
3164 }
3165
has_cap_mac_admin(bool audit)3166 static bool has_cap_mac_admin(bool audit)
3167 {
3168 const struct cred *cred = current_cred();
3169 unsigned int opts = audit ? CAP_OPT_NONE : CAP_OPT_NOAUDIT;
3170
3171 if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, opts))
3172 return false;
3173 if (cred_has_capability(cred, CAP_MAC_ADMIN, opts, true))
3174 return false;
3175 return true;
3176 }
3177
3178 /**
3179 * selinux_inode_xattr_skipcap - Skip the xattr capability checks?
3180 * @name: name of the xattr
3181 *
3182 * Returns 1 to indicate that SELinux "owns" the access control rights to xattrs
3183 * named @name; the LSM layer should avoid enforcing any traditional
3184 * capability based access controls on this xattr. Returns 0 to indicate that
3185 * SELinux does not "own" the access control rights to xattrs named @name and is
3186 * deferring to the LSM layer for further access controls, including capability
3187 * based controls.
3188 */
selinux_inode_xattr_skipcap(const char * name)3189 static int selinux_inode_xattr_skipcap(const char *name)
3190 {
3191 /* require capability check if not a selinux xattr */
3192 return !strcmp(name, XATTR_NAME_SELINUX);
3193 }
3194
selinux_inode_setxattr(struct mnt_idmap * idmap,struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3195 static int selinux_inode_setxattr(struct mnt_idmap *idmap,
3196 struct dentry *dentry, const char *name,
3197 const void *value, size_t size, int flags)
3198 {
3199 struct inode *inode = d_backing_inode(dentry);
3200 struct inode_security_struct *isec;
3201 struct superblock_security_struct *sbsec;
3202 struct common_audit_data ad;
3203 u32 newsid, sid = current_sid();
3204 int rc = 0;
3205
3206 /* if not a selinux xattr, only check the ordinary setattr perm */
3207 if (strcmp(name, XATTR_NAME_SELINUX))
3208 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3209
3210 if (!selinux_initialized())
3211 return (inode_owner_or_capable(idmap, inode) ? 0 : -EPERM);
3212
3213 sbsec = selinux_superblock(inode->i_sb);
3214 if (!(sbsec->flags & SBLABEL_MNT))
3215 return -EOPNOTSUPP;
3216
3217 if (!inode_owner_or_capable(idmap, inode))
3218 return -EPERM;
3219
3220 ad.type = LSM_AUDIT_DATA_DENTRY;
3221 ad.u.dentry = dentry;
3222
3223 isec = backing_inode_security(dentry);
3224 rc = avc_has_perm(sid, isec->sid, isec->sclass,
3225 FILE__RELABELFROM, &ad);
3226 if (rc)
3227 return rc;
3228
3229 rc = security_context_to_sid(value, size, &newsid,
3230 GFP_KERNEL);
3231 if (rc == -EINVAL) {
3232 if (!has_cap_mac_admin(true)) {
3233 struct audit_buffer *ab;
3234 size_t audit_size;
3235
3236 /* We strip a nul only if it is at the end, otherwise the
3237 * context contains a nul and we should audit that */
3238 if (value) {
3239 const char *str = value;
3240
3241 if (str[size - 1] == '\0')
3242 audit_size = size - 1;
3243 else
3244 audit_size = size;
3245 } else {
3246 audit_size = 0;
3247 }
3248 ab = audit_log_start(audit_context(),
3249 GFP_ATOMIC, AUDIT_SELINUX_ERR);
3250 if (!ab)
3251 return rc;
3252 audit_log_format(ab, "op=setxattr invalid_context=");
3253 audit_log_n_untrustedstring(ab, value, audit_size);
3254 audit_log_end(ab);
3255
3256 return rc;
3257 }
3258 rc = security_context_to_sid_force(value,
3259 size, &newsid);
3260 }
3261 if (rc)
3262 return rc;
3263
3264 rc = avc_has_perm(sid, newsid, isec->sclass,
3265 FILE__RELABELTO, &ad);
3266 if (rc)
3267 return rc;
3268
3269 rc = security_validate_transition(isec->sid, newsid,
3270 sid, isec->sclass);
3271 if (rc)
3272 return rc;
3273
3274 return avc_has_perm(newsid,
3275 sbsec->sid,
3276 SECCLASS_FILESYSTEM,
3277 FILESYSTEM__ASSOCIATE,
3278 &ad);
3279 }
3280
selinux_inode_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name,struct posix_acl * kacl)3281 static int selinux_inode_set_acl(struct mnt_idmap *idmap,
3282 struct dentry *dentry, const char *acl_name,
3283 struct posix_acl *kacl)
3284 {
3285 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3286 }
3287
selinux_inode_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)3288 static int selinux_inode_get_acl(struct mnt_idmap *idmap,
3289 struct dentry *dentry, const char *acl_name)
3290 {
3291 return dentry_has_perm(current_cred(), dentry, FILE__GETATTR);
3292 }
3293
selinux_inode_remove_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)3294 static int selinux_inode_remove_acl(struct mnt_idmap *idmap,
3295 struct dentry *dentry, const char *acl_name)
3296 {
3297 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3298 }
3299
selinux_inode_post_setxattr(struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3300 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3301 const void *value, size_t size,
3302 int flags)
3303 {
3304 struct inode *inode = d_backing_inode(dentry);
3305 struct inode_security_struct *isec;
3306 u32 newsid;
3307 int rc;
3308
3309 if (strcmp(name, XATTR_NAME_SELINUX)) {
3310 /* Not an attribute we recognize, so nothing to do. */
3311 return;
3312 }
3313
3314 if (!selinux_initialized()) {
3315 /* If we haven't even been initialized, then we can't validate
3316 * against a policy, so leave the label as invalid. It may
3317 * resolve to a valid label on the next revalidation try if
3318 * we've since initialized.
3319 */
3320 return;
3321 }
3322
3323 rc = security_context_to_sid_force(value, size,
3324 &newsid);
3325 if (rc) {
3326 pr_err("SELinux: unable to map context to SID"
3327 "for (%s, %lu), rc=%d\n",
3328 inode->i_sb->s_id, inode->i_ino, -rc);
3329 return;
3330 }
3331
3332 isec = backing_inode_security(dentry);
3333 spin_lock(&isec->lock);
3334 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3335 isec->sid = newsid;
3336 isec->initialized = LABEL_INITIALIZED;
3337 spin_unlock(&isec->lock);
3338 }
3339
selinux_inode_getxattr(struct dentry * dentry,const char * name)3340 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
3341 {
3342 const struct cred *cred = current_cred();
3343
3344 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3345 }
3346
selinux_inode_listxattr(struct dentry * dentry)3347 static int selinux_inode_listxattr(struct dentry *dentry)
3348 {
3349 const struct cred *cred = current_cred();
3350
3351 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3352 }
3353
selinux_inode_removexattr(struct mnt_idmap * idmap,struct dentry * dentry,const char * name)3354 static int selinux_inode_removexattr(struct mnt_idmap *idmap,
3355 struct dentry *dentry, const char *name)
3356 {
3357 /* if not a selinux xattr, only check the ordinary setattr perm */
3358 if (strcmp(name, XATTR_NAME_SELINUX))
3359 return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3360
3361 if (!selinux_initialized())
3362 return 0;
3363
3364 /* No one is allowed to remove a SELinux security label.
3365 You can change the label, but all data must be labeled. */
3366 return -EACCES;
3367 }
3368
selinux_path_notify(const struct path * path,u64 mask,unsigned int obj_type)3369 static int selinux_path_notify(const struct path *path, u64 mask,
3370 unsigned int obj_type)
3371 {
3372 int ret;
3373 u32 perm;
3374
3375 struct common_audit_data ad;
3376
3377 ad.type = LSM_AUDIT_DATA_PATH;
3378 ad.u.path = *path;
3379
3380 /*
3381 * Set permission needed based on the type of mark being set.
3382 * Performs an additional check for sb watches.
3383 */
3384 switch (obj_type) {
3385 case FSNOTIFY_OBJ_TYPE_VFSMOUNT:
3386 perm = FILE__WATCH_MOUNT;
3387 break;
3388 case FSNOTIFY_OBJ_TYPE_SB:
3389 perm = FILE__WATCH_SB;
3390 ret = superblock_has_perm(current_cred(), path->dentry->d_sb,
3391 FILESYSTEM__WATCH, &ad);
3392 if (ret)
3393 return ret;
3394 break;
3395 case FSNOTIFY_OBJ_TYPE_INODE:
3396 perm = FILE__WATCH;
3397 break;
3398 default:
3399 return -EINVAL;
3400 }
3401
3402 /* blocking watches require the file:watch_with_perm permission */
3403 if (mask & (ALL_FSNOTIFY_PERM_EVENTS))
3404 perm |= FILE__WATCH_WITH_PERM;
3405
3406 /* watches on read-like events need the file:watch_reads permission */
3407 if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_CLOSE_NOWRITE))
3408 perm |= FILE__WATCH_READS;
3409
3410 return path_has_perm(current_cred(), path, perm);
3411 }
3412
3413 /*
3414 * Copy the inode security context value to the user.
3415 *
3416 * Permission check is handled by selinux_inode_getxattr hook.
3417 */
selinux_inode_getsecurity(struct mnt_idmap * idmap,struct inode * inode,const char * name,void ** buffer,bool alloc)3418 static int selinux_inode_getsecurity(struct mnt_idmap *idmap,
3419 struct inode *inode, const char *name,
3420 void **buffer, bool alloc)
3421 {
3422 u32 size;
3423 int error;
3424 char *context = NULL;
3425 struct inode_security_struct *isec;
3426
3427 /*
3428 * If we're not initialized yet, then we can't validate contexts, so
3429 * just let vfs_getxattr fall back to using the on-disk xattr.
3430 */
3431 if (!selinux_initialized() ||
3432 strcmp(name, XATTR_SELINUX_SUFFIX))
3433 return -EOPNOTSUPP;
3434
3435 /*
3436 * If the caller has CAP_MAC_ADMIN, then get the raw context
3437 * value even if it is not defined by current policy; otherwise,
3438 * use the in-core value under current policy.
3439 * Use the non-auditing forms of the permission checks since
3440 * getxattr may be called by unprivileged processes commonly
3441 * and lack of permission just means that we fall back to the
3442 * in-core context value, not a denial.
3443 */
3444 isec = inode_security(inode);
3445 if (has_cap_mac_admin(false))
3446 error = security_sid_to_context_force(isec->sid, &context,
3447 &size);
3448 else
3449 error = security_sid_to_context(isec->sid,
3450 &context, &size);
3451 if (error)
3452 return error;
3453 error = size;
3454 if (alloc) {
3455 *buffer = context;
3456 goto out_nofree;
3457 }
3458 kfree(context);
3459 out_nofree:
3460 return error;
3461 }
3462
selinux_inode_setsecurity(struct inode * inode,const char * name,const void * value,size_t size,int flags)3463 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3464 const void *value, size_t size, int flags)
3465 {
3466 struct inode_security_struct *isec = inode_security_novalidate(inode);
3467 struct superblock_security_struct *sbsec;
3468 u32 newsid;
3469 int rc;
3470
3471 if (strcmp(name, XATTR_SELINUX_SUFFIX))
3472 return -EOPNOTSUPP;
3473
3474 sbsec = selinux_superblock(inode->i_sb);
3475 if (!(sbsec->flags & SBLABEL_MNT))
3476 return -EOPNOTSUPP;
3477
3478 if (!value || !size)
3479 return -EACCES;
3480
3481 rc = security_context_to_sid(value, size, &newsid,
3482 GFP_KERNEL);
3483 if (rc)
3484 return rc;
3485
3486 spin_lock(&isec->lock);
3487 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3488 isec->sid = newsid;
3489 isec->initialized = LABEL_INITIALIZED;
3490 spin_unlock(&isec->lock);
3491 return 0;
3492 }
3493
selinux_inode_listsecurity(struct inode * inode,char * buffer,size_t buffer_size)3494 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
3495 {
3496 const int len = sizeof(XATTR_NAME_SELINUX);
3497
3498 if (!selinux_initialized())
3499 return 0;
3500
3501 if (buffer && len <= buffer_size)
3502 memcpy(buffer, XATTR_NAME_SELINUX, len);
3503 return len;
3504 }
3505
selinux_inode_getsecid(struct inode * inode,u32 * secid)3506 static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
3507 {
3508 struct inode_security_struct *isec = inode_security_novalidate(inode);
3509 *secid = isec->sid;
3510 }
3511
selinux_inode_copy_up(struct dentry * src,struct cred ** new)3512 static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
3513 {
3514 u32 sid;
3515 struct task_security_struct *tsec;
3516 struct cred *new_creds = *new;
3517
3518 if (new_creds == NULL) {
3519 new_creds = prepare_creds();
3520 if (!new_creds)
3521 return -ENOMEM;
3522 }
3523
3524 tsec = selinux_cred(new_creds);
3525 /* Get label from overlay inode and set it in create_sid */
3526 selinux_inode_getsecid(d_inode(src), &sid);
3527 tsec->create_sid = sid;
3528 *new = new_creds;
3529 return 0;
3530 }
3531
selinux_inode_copy_up_xattr(struct dentry * dentry,const char * name)3532 static int selinux_inode_copy_up_xattr(struct dentry *dentry, const char *name)
3533 {
3534 /* The copy_up hook above sets the initial context on an inode, but we
3535 * don't then want to overwrite it by blindly copying all the lower
3536 * xattrs up. Instead, filter out SELinux-related xattrs following
3537 * policy load.
3538 */
3539 if (selinux_initialized() && !strcmp(name, XATTR_NAME_SELINUX))
3540 return -ECANCELED; /* Discard */
3541 /*
3542 * Any other attribute apart from SELINUX is not claimed, supported
3543 * by selinux.
3544 */
3545 return -EOPNOTSUPP;
3546 }
3547
3548 /* kernfs node operations */
3549
selinux_kernfs_init_security(struct kernfs_node * kn_dir,struct kernfs_node * kn)3550 static int selinux_kernfs_init_security(struct kernfs_node *kn_dir,
3551 struct kernfs_node *kn)
3552 {
3553 const struct task_security_struct *tsec = selinux_cred(current_cred());
3554 u32 parent_sid, newsid, clen;
3555 int rc;
3556 char *context;
3557
3558 rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, NULL, 0);
3559 if (rc == -ENODATA)
3560 return 0;
3561 else if (rc < 0)
3562 return rc;
3563
3564 clen = (u32)rc;
3565 context = kmalloc(clen, GFP_KERNEL);
3566 if (!context)
3567 return -ENOMEM;
3568
3569 rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, context, clen);
3570 if (rc < 0) {
3571 kfree(context);
3572 return rc;
3573 }
3574
3575 rc = security_context_to_sid(context, clen, &parent_sid,
3576 GFP_KERNEL);
3577 kfree(context);
3578 if (rc)
3579 return rc;
3580
3581 if (tsec->create_sid) {
3582 newsid = tsec->create_sid;
3583 } else {
3584 u16 secclass = inode_mode_to_security_class(kn->mode);
3585 struct qstr q;
3586
3587 q.name = kn->name;
3588 q.hash_len = hashlen_string(kn_dir, kn->name);
3589
3590 rc = security_transition_sid(tsec->sid,
3591 parent_sid, secclass, &q,
3592 &newsid);
3593 if (rc)
3594 return rc;
3595 }
3596
3597 rc = security_sid_to_context_force(newsid,
3598 &context, &clen);
3599 if (rc)
3600 return rc;
3601
3602 rc = kernfs_xattr_set(kn, XATTR_NAME_SELINUX, context, clen,
3603 XATTR_CREATE);
3604 kfree(context);
3605 return rc;
3606 }
3607
3608
3609 /* file security operations */
3610
selinux_revalidate_file_permission(struct file * file,int mask)3611 static int selinux_revalidate_file_permission(struct file *file, int mask)
3612 {
3613 const struct cred *cred = current_cred();
3614 struct inode *inode = file_inode(file);
3615
3616 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
3617 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
3618 mask |= MAY_APPEND;
3619
3620 return file_has_perm(cred, file,
3621 file_mask_to_av(inode->i_mode, mask));
3622 }
3623
selinux_file_permission(struct file * file,int mask)3624 static int selinux_file_permission(struct file *file, int mask)
3625 {
3626 struct inode *inode = file_inode(file);
3627 struct file_security_struct *fsec = selinux_file(file);
3628 struct inode_security_struct *isec;
3629 u32 sid = current_sid();
3630
3631 if (!mask)
3632 /* No permission to check. Existence test. */
3633 return 0;
3634
3635 isec = inode_security(inode);
3636 if (sid == fsec->sid && fsec->isid == isec->sid &&
3637 fsec->pseqno == avc_policy_seqno())
3638 /* No change since file_open check. */
3639 return 0;
3640
3641 return selinux_revalidate_file_permission(file, mask);
3642 }
3643
selinux_file_alloc_security(struct file * file)3644 static int selinux_file_alloc_security(struct file *file)
3645 {
3646 struct file_security_struct *fsec = selinux_file(file);
3647 u32 sid = current_sid();
3648
3649 fsec->sid = sid;
3650 fsec->fown_sid = sid;
3651
3652 return 0;
3653 }
3654
3655 /*
3656 * Check whether a task has the ioctl permission and cmd
3657 * operation to an inode.
3658 */
ioctl_has_perm(const struct cred * cred,struct file * file,u32 requested,u16 cmd)3659 static int ioctl_has_perm(const struct cred *cred, struct file *file,
3660 u32 requested, u16 cmd)
3661 {
3662 struct common_audit_data ad;
3663 struct file_security_struct *fsec = selinux_file(file);
3664 struct inode *inode = file_inode(file);
3665 struct inode_security_struct *isec;
3666 struct lsm_ioctlop_audit ioctl;
3667 u32 ssid = cred_sid(cred);
3668 int rc;
3669 u8 driver = cmd >> 8;
3670 u8 xperm = cmd & 0xff;
3671
3672 ad.type = LSM_AUDIT_DATA_IOCTL_OP;
3673 ad.u.op = &ioctl;
3674 ad.u.op->cmd = cmd;
3675 ad.u.op->path = file->f_path;
3676
3677 if (ssid != fsec->sid) {
3678 rc = avc_has_perm(ssid, fsec->sid,
3679 SECCLASS_FD,
3680 FD__USE,
3681 &ad);
3682 if (rc)
3683 goto out;
3684 }
3685
3686 if (unlikely(IS_PRIVATE(inode)))
3687 return 0;
3688
3689 isec = inode_security(inode);
3690 rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass,
3691 requested, driver, xperm, &ad);
3692 out:
3693 return rc;
3694 }
3695
selinux_file_ioctl(struct file * file,unsigned int cmd,unsigned long arg)3696 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3697 unsigned long arg)
3698 {
3699 const struct cred *cred = current_cred();
3700 int error = 0;
3701
3702 switch (cmd) {
3703 case FIONREAD:
3704 case FIBMAP:
3705 case FIGETBSZ:
3706 case FS_IOC_GETFLAGS:
3707 case FS_IOC_GETVERSION:
3708 error = file_has_perm(cred, file, FILE__GETATTR);
3709 break;
3710
3711 case FS_IOC_SETFLAGS:
3712 case FS_IOC_SETVERSION:
3713 error = file_has_perm(cred, file, FILE__SETATTR);
3714 break;
3715
3716 /* sys_ioctl() checks */
3717 case FIONBIO:
3718 case FIOASYNC:
3719 error = file_has_perm(cred, file, 0);
3720 break;
3721
3722 case KDSKBENT:
3723 case KDSKBSENT:
3724 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3725 CAP_OPT_NONE, true);
3726 break;
3727
3728 case FIOCLEX:
3729 case FIONCLEX:
3730 if (!selinux_policycap_ioctl_skip_cloexec())
3731 error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3732 break;
3733
3734 /* default case assumes that the command will go
3735 * to the file's ioctl() function.
3736 */
3737 default:
3738 error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3739 }
3740 return error;
3741 }
3742
selinux_file_ioctl_compat(struct file * file,unsigned int cmd,unsigned long arg)3743 static int selinux_file_ioctl_compat(struct file *file, unsigned int cmd,
3744 unsigned long arg)
3745 {
3746 /*
3747 * If we are in a 64-bit kernel running 32-bit userspace, we need to
3748 * make sure we don't compare 32-bit flags to 64-bit flags.
3749 */
3750 switch (cmd) {
3751 case FS_IOC32_GETFLAGS:
3752 cmd = FS_IOC_GETFLAGS;
3753 break;
3754 case FS_IOC32_SETFLAGS:
3755 cmd = FS_IOC_SETFLAGS;
3756 break;
3757 case FS_IOC32_GETVERSION:
3758 cmd = FS_IOC_GETVERSION;
3759 break;
3760 case FS_IOC32_SETVERSION:
3761 cmd = FS_IOC_SETVERSION;
3762 break;
3763 default:
3764 break;
3765 }
3766
3767 return selinux_file_ioctl(file, cmd, arg);
3768 }
3769
3770 static int default_noexec __ro_after_init;
3771
file_map_prot_check(struct file * file,unsigned long prot,int shared)3772 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3773 {
3774 const struct cred *cred = current_cred();
3775 u32 sid = cred_sid(cred);
3776 int rc = 0;
3777
3778 if (default_noexec &&
3779 (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) ||
3780 (!shared && (prot & PROT_WRITE)))) {
3781 /*
3782 * We are making executable an anonymous mapping or a
3783 * private file mapping that will also be writable.
3784 * This has an additional check.
3785 */
3786 rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3787 PROCESS__EXECMEM, NULL);
3788 if (rc)
3789 goto error;
3790 }
3791
3792 if (file) {
3793 /* read access is always possible with a mapping */
3794 u32 av = FILE__READ;
3795
3796 /* write access only matters if the mapping is shared */
3797 if (shared && (prot & PROT_WRITE))
3798 av |= FILE__WRITE;
3799
3800 if (prot & PROT_EXEC)
3801 av |= FILE__EXECUTE;
3802
3803 return file_has_perm(cred, file, av);
3804 }
3805
3806 error:
3807 return rc;
3808 }
3809
selinux_mmap_addr(unsigned long addr)3810 static int selinux_mmap_addr(unsigned long addr)
3811 {
3812 int rc = 0;
3813
3814 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3815 u32 sid = current_sid();
3816 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3817 MEMPROTECT__MMAP_ZERO, NULL);
3818 }
3819
3820 return rc;
3821 }
3822
selinux_mmap_file(struct file * file,unsigned long reqprot __always_unused,unsigned long prot,unsigned long flags)3823 static int selinux_mmap_file(struct file *file,
3824 unsigned long reqprot __always_unused,
3825 unsigned long prot, unsigned long flags)
3826 {
3827 struct common_audit_data ad;
3828 int rc;
3829
3830 if (file) {
3831 ad.type = LSM_AUDIT_DATA_FILE;
3832 ad.u.file = file;
3833 rc = inode_has_perm(current_cred(), file_inode(file),
3834 FILE__MAP, &ad);
3835 if (rc)
3836 return rc;
3837 }
3838
3839 return file_map_prot_check(file, prot,
3840 (flags & MAP_TYPE) == MAP_SHARED);
3841 }
3842
selinux_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot __always_unused,unsigned long prot)3843 static int selinux_file_mprotect(struct vm_area_struct *vma,
3844 unsigned long reqprot __always_unused,
3845 unsigned long prot)
3846 {
3847 const struct cred *cred = current_cred();
3848 u32 sid = cred_sid(cred);
3849
3850 if (default_noexec &&
3851 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3852 int rc = 0;
3853 /*
3854 * We don't use the vma_is_initial_heap() helper as it has
3855 * a history of problems and is currently broken on systems
3856 * where there is no heap, e.g. brk == start_brk. Before
3857 * replacing the conditional below with vma_is_initial_heap(),
3858 * or something similar, please ensure that the logic is the
3859 * same as what we have below or you have tested every possible
3860 * corner case you can think to test.
3861 */
3862 if (vma->vm_start >= vma->vm_mm->start_brk &&
3863 vma->vm_end <= vma->vm_mm->brk) {
3864 rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3865 PROCESS__EXECHEAP, NULL);
3866 } else if (!vma->vm_file && (vma_is_initial_stack(vma) ||
3867 vma_is_stack_for_current(vma))) {
3868 rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3869 PROCESS__EXECSTACK, NULL);
3870 } else if (vma->vm_file && vma->anon_vma) {
3871 /*
3872 * We are making executable a file mapping that has
3873 * had some COW done. Since pages might have been
3874 * written, check ability to execute the possibly
3875 * modified content. This typically should only
3876 * occur for text relocations.
3877 */
3878 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3879 }
3880 if (rc)
3881 return rc;
3882 }
3883
3884 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3885 }
3886
selinux_file_lock(struct file * file,unsigned int cmd)3887 static int selinux_file_lock(struct file *file, unsigned int cmd)
3888 {
3889 const struct cred *cred = current_cred();
3890
3891 return file_has_perm(cred, file, FILE__LOCK);
3892 }
3893
selinux_file_fcntl(struct file * file,unsigned int cmd,unsigned long arg)3894 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3895 unsigned long arg)
3896 {
3897 const struct cred *cred = current_cred();
3898 int err = 0;
3899
3900 switch (cmd) {
3901 case F_SETFL:
3902 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3903 err = file_has_perm(cred, file, FILE__WRITE);
3904 break;
3905 }
3906 fallthrough;
3907 case F_SETOWN:
3908 case F_SETSIG:
3909 case F_GETFL:
3910 case F_GETOWN:
3911 case F_GETSIG:
3912 case F_GETOWNER_UIDS:
3913 /* Just check FD__USE permission */
3914 err = file_has_perm(cred, file, 0);
3915 break;
3916 case F_GETLK:
3917 case F_SETLK:
3918 case F_SETLKW:
3919 case F_OFD_GETLK:
3920 case F_OFD_SETLK:
3921 case F_OFD_SETLKW:
3922 #if BITS_PER_LONG == 32
3923 case F_GETLK64:
3924 case F_SETLK64:
3925 case F_SETLKW64:
3926 #endif
3927 err = file_has_perm(cred, file, FILE__LOCK);
3928 break;
3929 }
3930
3931 return err;
3932 }
3933
selinux_file_set_fowner(struct file * file)3934 static void selinux_file_set_fowner(struct file *file)
3935 {
3936 struct file_security_struct *fsec;
3937
3938 fsec = selinux_file(file);
3939 fsec->fown_sid = current_sid();
3940 }
3941
selinux_file_send_sigiotask(struct task_struct * tsk,struct fown_struct * fown,int signum)3942 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3943 struct fown_struct *fown, int signum)
3944 {
3945 struct file *file;
3946 u32 sid = task_sid_obj(tsk);
3947 u32 perm;
3948 struct file_security_struct *fsec;
3949
3950 /* struct fown_struct is never outside the context of a struct file */
3951 file = fown->file;
3952
3953 fsec = selinux_file(file);
3954
3955 if (!signum)
3956 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3957 else
3958 perm = signal_to_av(signum);
3959
3960 return avc_has_perm(fsec->fown_sid, sid,
3961 SECCLASS_PROCESS, perm, NULL);
3962 }
3963
selinux_file_receive(struct file * file)3964 static int selinux_file_receive(struct file *file)
3965 {
3966 const struct cred *cred = current_cred();
3967
3968 return file_has_perm(cred, file, file_to_av(file));
3969 }
3970
selinux_file_open(struct file * file)3971 static int selinux_file_open(struct file *file)
3972 {
3973 struct file_security_struct *fsec;
3974 struct inode_security_struct *isec;
3975
3976 fsec = selinux_file(file);
3977 isec = inode_security(file_inode(file));
3978 /*
3979 * Save inode label and policy sequence number
3980 * at open-time so that selinux_file_permission
3981 * can determine whether revalidation is necessary.
3982 * Task label is already saved in the file security
3983 * struct as its SID.
3984 */
3985 fsec->isid = isec->sid;
3986 fsec->pseqno = avc_policy_seqno();
3987 /*
3988 * Since the inode label or policy seqno may have changed
3989 * between the selinux_inode_permission check and the saving
3990 * of state above, recheck that access is still permitted.
3991 * Otherwise, access might never be revalidated against the
3992 * new inode label or new policy.
3993 * This check is not redundant - do not remove.
3994 */
3995 return file_path_has_perm(file->f_cred, file, open_file_to_av(file));
3996 }
3997
3998 /* task security operations */
3999
selinux_task_alloc(struct task_struct * task,unsigned long clone_flags)4000 static int selinux_task_alloc(struct task_struct *task,
4001 unsigned long clone_flags)
4002 {
4003 u32 sid = current_sid();
4004
4005 return avc_has_perm(sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL);
4006 }
4007
4008 /*
4009 * prepare a new set of credentials for modification
4010 */
selinux_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)4011 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
4012 gfp_t gfp)
4013 {
4014 const struct task_security_struct *old_tsec = selinux_cred(old);
4015 struct task_security_struct *tsec = selinux_cred(new);
4016
4017 *tsec = *old_tsec;
4018 return 0;
4019 }
4020
4021 /*
4022 * transfer the SELinux data to a blank set of creds
4023 */
selinux_cred_transfer(struct cred * new,const struct cred * old)4024 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
4025 {
4026 const struct task_security_struct *old_tsec = selinux_cred(old);
4027 struct task_security_struct *tsec = selinux_cred(new);
4028
4029 *tsec = *old_tsec;
4030 }
4031
selinux_cred_getsecid(const struct cred * c,u32 * secid)4032 static void selinux_cred_getsecid(const struct cred *c, u32 *secid)
4033 {
4034 *secid = cred_sid(c);
4035 }
4036
4037 /*
4038 * set the security data for a kernel service
4039 * - all the creation contexts are set to unlabelled
4040 */
selinux_kernel_act_as(struct cred * new,u32 secid)4041 static int selinux_kernel_act_as(struct cred *new, u32 secid)
4042 {
4043 struct task_security_struct *tsec = selinux_cred(new);
4044 u32 sid = current_sid();
4045 int ret;
4046
4047 ret = avc_has_perm(sid, secid,
4048 SECCLASS_KERNEL_SERVICE,
4049 KERNEL_SERVICE__USE_AS_OVERRIDE,
4050 NULL);
4051 if (ret == 0) {
4052 tsec->sid = secid;
4053 tsec->create_sid = 0;
4054 tsec->keycreate_sid = 0;
4055 tsec->sockcreate_sid = 0;
4056 }
4057 return ret;
4058 }
4059
4060 /*
4061 * set the file creation context in a security record to the same as the
4062 * objective context of the specified inode
4063 */
selinux_kernel_create_files_as(struct cred * new,struct inode * inode)4064 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
4065 {
4066 struct inode_security_struct *isec = inode_security(inode);
4067 struct task_security_struct *tsec = selinux_cred(new);
4068 u32 sid = current_sid();
4069 int ret;
4070
4071 ret = avc_has_perm(sid, isec->sid,
4072 SECCLASS_KERNEL_SERVICE,
4073 KERNEL_SERVICE__CREATE_FILES_AS,
4074 NULL);
4075
4076 if (ret == 0)
4077 tsec->create_sid = isec->sid;
4078 return ret;
4079 }
4080
selinux_kernel_module_request(char * kmod_name)4081 static int selinux_kernel_module_request(char *kmod_name)
4082 {
4083 struct common_audit_data ad;
4084
4085 ad.type = LSM_AUDIT_DATA_KMOD;
4086 ad.u.kmod_name = kmod_name;
4087
4088 return avc_has_perm(current_sid(), SECINITSID_KERNEL, SECCLASS_SYSTEM,
4089 SYSTEM__MODULE_REQUEST, &ad);
4090 }
4091
selinux_kernel_module_from_file(struct file * file)4092 static int selinux_kernel_module_from_file(struct file *file)
4093 {
4094 struct common_audit_data ad;
4095 struct inode_security_struct *isec;
4096 struct file_security_struct *fsec;
4097 u32 sid = current_sid();
4098 int rc;
4099
4100 /* init_module */
4101 if (file == NULL)
4102 return avc_has_perm(sid, sid, SECCLASS_SYSTEM,
4103 SYSTEM__MODULE_LOAD, NULL);
4104
4105 /* finit_module */
4106
4107 ad.type = LSM_AUDIT_DATA_FILE;
4108 ad.u.file = file;
4109
4110 fsec = selinux_file(file);
4111 if (sid != fsec->sid) {
4112 rc = avc_has_perm(sid, fsec->sid, SECCLASS_FD, FD__USE, &ad);
4113 if (rc)
4114 return rc;
4115 }
4116
4117 isec = inode_security(file_inode(file));
4118 return avc_has_perm(sid, isec->sid, SECCLASS_SYSTEM,
4119 SYSTEM__MODULE_LOAD, &ad);
4120 }
4121
selinux_kernel_read_file(struct file * file,enum kernel_read_file_id id,bool contents)4122 static int selinux_kernel_read_file(struct file *file,
4123 enum kernel_read_file_id id,
4124 bool contents)
4125 {
4126 int rc = 0;
4127
4128 switch (id) {
4129 case READING_MODULE:
4130 rc = selinux_kernel_module_from_file(contents ? file : NULL);
4131 break;
4132 default:
4133 break;
4134 }
4135
4136 return rc;
4137 }
4138
selinux_kernel_load_data(enum kernel_load_data_id id,bool contents)4139 static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents)
4140 {
4141 int rc = 0;
4142
4143 switch (id) {
4144 case LOADING_MODULE:
4145 rc = selinux_kernel_module_from_file(NULL);
4146 break;
4147 default:
4148 break;
4149 }
4150
4151 return rc;
4152 }
4153
selinux_task_setpgid(struct task_struct * p,pid_t pgid)4154 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
4155 {
4156 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4157 PROCESS__SETPGID, NULL);
4158 }
4159
selinux_task_getpgid(struct task_struct * p)4160 static int selinux_task_getpgid(struct task_struct *p)
4161 {
4162 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4163 PROCESS__GETPGID, NULL);
4164 }
4165
selinux_task_getsid(struct task_struct * p)4166 static int selinux_task_getsid(struct task_struct *p)
4167 {
4168 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4169 PROCESS__GETSESSION, NULL);
4170 }
4171
selinux_current_getsecid_subj(u32 * secid)4172 static void selinux_current_getsecid_subj(u32 *secid)
4173 {
4174 *secid = current_sid();
4175 }
4176
selinux_task_getsecid_obj(struct task_struct * p,u32 * secid)4177 static void selinux_task_getsecid_obj(struct task_struct *p, u32 *secid)
4178 {
4179 *secid = task_sid_obj(p);
4180 }
4181
selinux_task_setnice(struct task_struct * p,int nice)4182 static int selinux_task_setnice(struct task_struct *p, int nice)
4183 {
4184 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4185 PROCESS__SETSCHED, NULL);
4186 }
4187
selinux_task_setioprio(struct task_struct * p,int ioprio)4188 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
4189 {
4190 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4191 PROCESS__SETSCHED, NULL);
4192 }
4193
selinux_task_getioprio(struct task_struct * p)4194 static int selinux_task_getioprio(struct task_struct *p)
4195 {
4196 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4197 PROCESS__GETSCHED, NULL);
4198 }
4199
selinux_task_prlimit(const struct cred * cred,const struct cred * tcred,unsigned int flags)4200 static int selinux_task_prlimit(const struct cred *cred, const struct cred *tcred,
4201 unsigned int flags)
4202 {
4203 u32 av = 0;
4204
4205 if (!flags)
4206 return 0;
4207 if (flags & LSM_PRLIMIT_WRITE)
4208 av |= PROCESS__SETRLIMIT;
4209 if (flags & LSM_PRLIMIT_READ)
4210 av |= PROCESS__GETRLIMIT;
4211 return avc_has_perm(cred_sid(cred), cred_sid(tcred),
4212 SECCLASS_PROCESS, av, NULL);
4213 }
4214
selinux_task_setrlimit(struct task_struct * p,unsigned int resource,struct rlimit * new_rlim)4215 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
4216 struct rlimit *new_rlim)
4217 {
4218 struct rlimit *old_rlim = p->signal->rlim + resource;
4219
4220 /* Control the ability to change the hard limit (whether
4221 lowering or raising it), so that the hard limit can
4222 later be used as a safe reset point for the soft limit
4223 upon context transitions. See selinux_bprm_committing_creds. */
4224 if (old_rlim->rlim_max != new_rlim->rlim_max)
4225 return avc_has_perm(current_sid(), task_sid_obj(p),
4226 SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL);
4227
4228 return 0;
4229 }
4230
selinux_task_setscheduler(struct task_struct * p)4231 static int selinux_task_setscheduler(struct task_struct *p)
4232 {
4233 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4234 PROCESS__SETSCHED, NULL);
4235 }
4236
selinux_task_getscheduler(struct task_struct * p)4237 static int selinux_task_getscheduler(struct task_struct *p)
4238 {
4239 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4240 PROCESS__GETSCHED, NULL);
4241 }
4242
selinux_task_movememory(struct task_struct * p)4243 static int selinux_task_movememory(struct task_struct *p)
4244 {
4245 return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4246 PROCESS__SETSCHED, NULL);
4247 }
4248
selinux_task_kill(struct task_struct * p,struct kernel_siginfo * info,int sig,const struct cred * cred)4249 static int selinux_task_kill(struct task_struct *p, struct kernel_siginfo *info,
4250 int sig, const struct cred *cred)
4251 {
4252 u32 secid;
4253 u32 perm;
4254
4255 if (!sig)
4256 perm = PROCESS__SIGNULL; /* null signal; existence test */
4257 else
4258 perm = signal_to_av(sig);
4259 if (!cred)
4260 secid = current_sid();
4261 else
4262 secid = cred_sid(cred);
4263 return avc_has_perm(secid, task_sid_obj(p), SECCLASS_PROCESS, perm, NULL);
4264 }
4265
selinux_task_to_inode(struct task_struct * p,struct inode * inode)4266 static void selinux_task_to_inode(struct task_struct *p,
4267 struct inode *inode)
4268 {
4269 struct inode_security_struct *isec = selinux_inode(inode);
4270 u32 sid = task_sid_obj(p);
4271
4272 spin_lock(&isec->lock);
4273 isec->sclass = inode_mode_to_security_class(inode->i_mode);
4274 isec->sid = sid;
4275 isec->initialized = LABEL_INITIALIZED;
4276 spin_unlock(&isec->lock);
4277 }
4278
selinux_userns_create(const struct cred * cred)4279 static int selinux_userns_create(const struct cred *cred)
4280 {
4281 u32 sid = current_sid();
4282
4283 return avc_has_perm(sid, sid, SECCLASS_USER_NAMESPACE,
4284 USER_NAMESPACE__CREATE, NULL);
4285 }
4286
4287 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv4(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4288 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
4289 struct common_audit_data *ad, u8 *proto)
4290 {
4291 int offset, ihlen, ret = -EINVAL;
4292 struct iphdr _iph, *ih;
4293
4294 offset = skb_network_offset(skb);
4295 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
4296 if (ih == NULL)
4297 goto out;
4298
4299 ihlen = ih->ihl * 4;
4300 if (ihlen < sizeof(_iph))
4301 goto out;
4302
4303 ad->u.net->v4info.saddr = ih->saddr;
4304 ad->u.net->v4info.daddr = ih->daddr;
4305 ret = 0;
4306
4307 if (proto)
4308 *proto = ih->protocol;
4309
4310 switch (ih->protocol) {
4311 case IPPROTO_TCP: {
4312 struct tcphdr _tcph, *th;
4313
4314 if (ntohs(ih->frag_off) & IP_OFFSET)
4315 break;
4316
4317 offset += ihlen;
4318 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4319 if (th == NULL)
4320 break;
4321
4322 ad->u.net->sport = th->source;
4323 ad->u.net->dport = th->dest;
4324 break;
4325 }
4326
4327 case IPPROTO_UDP: {
4328 struct udphdr _udph, *uh;
4329
4330 if (ntohs(ih->frag_off) & IP_OFFSET)
4331 break;
4332
4333 offset += ihlen;
4334 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4335 if (uh == NULL)
4336 break;
4337
4338 ad->u.net->sport = uh->source;
4339 ad->u.net->dport = uh->dest;
4340 break;
4341 }
4342
4343 case IPPROTO_DCCP: {
4344 struct dccp_hdr _dccph, *dh;
4345
4346 if (ntohs(ih->frag_off) & IP_OFFSET)
4347 break;
4348
4349 offset += ihlen;
4350 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4351 if (dh == NULL)
4352 break;
4353
4354 ad->u.net->sport = dh->dccph_sport;
4355 ad->u.net->dport = dh->dccph_dport;
4356 break;
4357 }
4358
4359 #if IS_ENABLED(CONFIG_IP_SCTP)
4360 case IPPROTO_SCTP: {
4361 struct sctphdr _sctph, *sh;
4362
4363 if (ntohs(ih->frag_off) & IP_OFFSET)
4364 break;
4365
4366 offset += ihlen;
4367 sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4368 if (sh == NULL)
4369 break;
4370
4371 ad->u.net->sport = sh->source;
4372 ad->u.net->dport = sh->dest;
4373 break;
4374 }
4375 #endif
4376 default:
4377 break;
4378 }
4379 out:
4380 return ret;
4381 }
4382
4383 #if IS_ENABLED(CONFIG_IPV6)
4384
4385 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv6(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4386 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
4387 struct common_audit_data *ad, u8 *proto)
4388 {
4389 u8 nexthdr;
4390 int ret = -EINVAL, offset;
4391 struct ipv6hdr _ipv6h, *ip6;
4392 __be16 frag_off;
4393
4394 offset = skb_network_offset(skb);
4395 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
4396 if (ip6 == NULL)
4397 goto out;
4398
4399 ad->u.net->v6info.saddr = ip6->saddr;
4400 ad->u.net->v6info.daddr = ip6->daddr;
4401 ret = 0;
4402
4403 nexthdr = ip6->nexthdr;
4404 offset += sizeof(_ipv6h);
4405 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
4406 if (offset < 0)
4407 goto out;
4408
4409 if (proto)
4410 *proto = nexthdr;
4411
4412 switch (nexthdr) {
4413 case IPPROTO_TCP: {
4414 struct tcphdr _tcph, *th;
4415
4416 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4417 if (th == NULL)
4418 break;
4419
4420 ad->u.net->sport = th->source;
4421 ad->u.net->dport = th->dest;
4422 break;
4423 }
4424
4425 case IPPROTO_UDP: {
4426 struct udphdr _udph, *uh;
4427
4428 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4429 if (uh == NULL)
4430 break;
4431
4432 ad->u.net->sport = uh->source;
4433 ad->u.net->dport = uh->dest;
4434 break;
4435 }
4436
4437 case IPPROTO_DCCP: {
4438 struct dccp_hdr _dccph, *dh;
4439
4440 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4441 if (dh == NULL)
4442 break;
4443
4444 ad->u.net->sport = dh->dccph_sport;
4445 ad->u.net->dport = dh->dccph_dport;
4446 break;
4447 }
4448
4449 #if IS_ENABLED(CONFIG_IP_SCTP)
4450 case IPPROTO_SCTP: {
4451 struct sctphdr _sctph, *sh;
4452
4453 sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4454 if (sh == NULL)
4455 break;
4456
4457 ad->u.net->sport = sh->source;
4458 ad->u.net->dport = sh->dest;
4459 break;
4460 }
4461 #endif
4462 /* includes fragments */
4463 default:
4464 break;
4465 }
4466 out:
4467 return ret;
4468 }
4469
4470 #endif /* IPV6 */
4471
selinux_parse_skb(struct sk_buff * skb,struct common_audit_data * ad,char ** _addrp,int src,u8 * proto)4472 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
4473 char **_addrp, int src, u8 *proto)
4474 {
4475 char *addrp;
4476 int ret;
4477
4478 switch (ad->u.net->family) {
4479 case PF_INET:
4480 ret = selinux_parse_skb_ipv4(skb, ad, proto);
4481 if (ret)
4482 goto parse_error;
4483 addrp = (char *)(src ? &ad->u.net->v4info.saddr :
4484 &ad->u.net->v4info.daddr);
4485 goto okay;
4486
4487 #if IS_ENABLED(CONFIG_IPV6)
4488 case PF_INET6:
4489 ret = selinux_parse_skb_ipv6(skb, ad, proto);
4490 if (ret)
4491 goto parse_error;
4492 addrp = (char *)(src ? &ad->u.net->v6info.saddr :
4493 &ad->u.net->v6info.daddr);
4494 goto okay;
4495 #endif /* IPV6 */
4496 default:
4497 addrp = NULL;
4498 goto okay;
4499 }
4500
4501 parse_error:
4502 pr_warn(
4503 "SELinux: failure in selinux_parse_skb(),"
4504 " unable to parse packet\n");
4505 return ret;
4506
4507 okay:
4508 if (_addrp)
4509 *_addrp = addrp;
4510 return 0;
4511 }
4512
4513 /**
4514 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
4515 * @skb: the packet
4516 * @family: protocol family
4517 * @sid: the packet's peer label SID
4518 *
4519 * Description:
4520 * Check the various different forms of network peer labeling and determine
4521 * the peer label/SID for the packet; most of the magic actually occurs in
4522 * the security server function security_net_peersid_cmp(). The function
4523 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
4524 * or -EACCES if @sid is invalid due to inconsistencies with the different
4525 * peer labels.
4526 *
4527 */
selinux_skb_peerlbl_sid(struct sk_buff * skb,u16 family,u32 * sid)4528 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
4529 {
4530 int err;
4531 u32 xfrm_sid;
4532 u32 nlbl_sid;
4533 u32 nlbl_type;
4534
4535 err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
4536 if (unlikely(err))
4537 return -EACCES;
4538 err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
4539 if (unlikely(err))
4540 return -EACCES;
4541
4542 err = security_net_peersid_resolve(nlbl_sid,
4543 nlbl_type, xfrm_sid, sid);
4544 if (unlikely(err)) {
4545 pr_warn(
4546 "SELinux: failure in selinux_skb_peerlbl_sid(),"
4547 " unable to determine packet's peer label\n");
4548 return -EACCES;
4549 }
4550
4551 return 0;
4552 }
4553
4554 /**
4555 * selinux_conn_sid - Determine the child socket label for a connection
4556 * @sk_sid: the parent socket's SID
4557 * @skb_sid: the packet's SID
4558 * @conn_sid: the resulting connection SID
4559 *
4560 * If @skb_sid is valid then the user:role:type information from @sk_sid is
4561 * combined with the MLS information from @skb_sid in order to create
4562 * @conn_sid. If @skb_sid is not valid then @conn_sid is simply a copy
4563 * of @sk_sid. Returns zero on success, negative values on failure.
4564 *
4565 */
selinux_conn_sid(u32 sk_sid,u32 skb_sid,u32 * conn_sid)4566 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
4567 {
4568 int err = 0;
4569
4570 if (skb_sid != SECSID_NULL)
4571 err = security_sid_mls_copy(sk_sid, skb_sid,
4572 conn_sid);
4573 else
4574 *conn_sid = sk_sid;
4575
4576 return err;
4577 }
4578
4579 /* socket security operations */
4580
socket_sockcreate_sid(const struct task_security_struct * tsec,u16 secclass,u32 * socksid)4581 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
4582 u16 secclass, u32 *socksid)
4583 {
4584 if (tsec->sockcreate_sid > SECSID_NULL) {
4585 *socksid = tsec->sockcreate_sid;
4586 return 0;
4587 }
4588
4589 return security_transition_sid(tsec->sid, tsec->sid,
4590 secclass, NULL, socksid);
4591 }
4592
sock_has_perm(struct sock * sk,u32 perms)4593 static int sock_has_perm(struct sock *sk, u32 perms)
4594 {
4595 struct sk_security_struct *sksec = selinux_sock(sk);
4596 struct common_audit_data ad;
4597 struct lsm_network_audit net;
4598
4599 if (sksec->sid == SECINITSID_KERNEL)
4600 return 0;
4601
4602 /*
4603 * Before POLICYDB_CAP_USERSPACE_INITIAL_CONTEXT, sockets that
4604 * inherited the kernel context from early boot used to be skipped
4605 * here, so preserve that behavior unless the capability is set.
4606 *
4607 * By setting the capability the policy signals that it is ready
4608 * for this quirk to be fixed. Note that sockets created by a kernel
4609 * thread or a usermode helper executed without a transition will
4610 * still be skipped in this check regardless of the policycap
4611 * setting.
4612 */
4613 if (!selinux_policycap_userspace_initial_context() &&
4614 sksec->sid == SECINITSID_INIT)
4615 return 0;
4616
4617 ad_net_init_from_sk(&ad, &net, sk);
4618
4619 return avc_has_perm(current_sid(), sksec->sid, sksec->sclass, perms,
4620 &ad);
4621 }
4622
selinux_socket_create(int family,int type,int protocol,int kern)4623 static int selinux_socket_create(int family, int type,
4624 int protocol, int kern)
4625 {
4626 const struct task_security_struct *tsec = selinux_cred(current_cred());
4627 u32 newsid;
4628 u16 secclass;
4629 int rc;
4630
4631 if (kern)
4632 return 0;
4633
4634 secclass = socket_type_to_security_class(family, type, protocol);
4635 rc = socket_sockcreate_sid(tsec, secclass, &newsid);
4636 if (rc)
4637 return rc;
4638
4639 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
4640 }
4641
selinux_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)4642 static int selinux_socket_post_create(struct socket *sock, int family,
4643 int type, int protocol, int kern)
4644 {
4645 const struct task_security_struct *tsec = selinux_cred(current_cred());
4646 struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
4647 struct sk_security_struct *sksec;
4648 u16 sclass = socket_type_to_security_class(family, type, protocol);
4649 u32 sid = SECINITSID_KERNEL;
4650 int err = 0;
4651
4652 if (!kern) {
4653 err = socket_sockcreate_sid(tsec, sclass, &sid);
4654 if (err)
4655 return err;
4656 }
4657
4658 isec->sclass = sclass;
4659 isec->sid = sid;
4660 isec->initialized = LABEL_INITIALIZED;
4661
4662 if (sock->sk) {
4663 sksec = selinux_sock(sock->sk);
4664 sksec->sclass = sclass;
4665 sksec->sid = sid;
4666 /* Allows detection of the first association on this socket */
4667 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4668 sksec->sctp_assoc_state = SCTP_ASSOC_UNSET;
4669
4670 err = selinux_netlbl_socket_post_create(sock->sk, family);
4671 }
4672
4673 return err;
4674 }
4675
selinux_socket_socketpair(struct socket * socka,struct socket * sockb)4676 static int selinux_socket_socketpair(struct socket *socka,
4677 struct socket *sockb)
4678 {
4679 struct sk_security_struct *sksec_a = selinux_sock(socka->sk);
4680 struct sk_security_struct *sksec_b = selinux_sock(sockb->sk);
4681
4682 sksec_a->peer_sid = sksec_b->sid;
4683 sksec_b->peer_sid = sksec_a->sid;
4684
4685 return 0;
4686 }
4687
4688 /* Range of port numbers used to automatically bind.
4689 Need to determine whether we should perform a name_bind
4690 permission check between the socket and the port number. */
4691
selinux_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)4692 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
4693 {
4694 struct sock *sk = sock->sk;
4695 struct sk_security_struct *sksec = selinux_sock(sk);
4696 u16 family;
4697 int err;
4698
4699 err = sock_has_perm(sk, SOCKET__BIND);
4700 if (err)
4701 goto out;
4702
4703 /* If PF_INET or PF_INET6, check name_bind permission for the port. */
4704 family = sk->sk_family;
4705 if (family == PF_INET || family == PF_INET6) {
4706 char *addrp;
4707 struct common_audit_data ad;
4708 struct lsm_network_audit net = {0,};
4709 struct sockaddr_in *addr4 = NULL;
4710 struct sockaddr_in6 *addr6 = NULL;
4711 u16 family_sa;
4712 unsigned short snum;
4713 u32 sid, node_perm;
4714
4715 /*
4716 * sctp_bindx(3) calls via selinux_sctp_bind_connect()
4717 * that validates multiple binding addresses. Because of this
4718 * need to check address->sa_family as it is possible to have
4719 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4720 */
4721 if (addrlen < offsetofend(struct sockaddr, sa_family))
4722 return -EINVAL;
4723 family_sa = address->sa_family;
4724 switch (family_sa) {
4725 case AF_UNSPEC:
4726 case AF_INET:
4727 if (addrlen < sizeof(struct sockaddr_in))
4728 return -EINVAL;
4729 addr4 = (struct sockaddr_in *)address;
4730 if (family_sa == AF_UNSPEC) {
4731 if (family == PF_INET6) {
4732 /* Length check from inet6_bind_sk() */
4733 if (addrlen < SIN6_LEN_RFC2133)
4734 return -EINVAL;
4735 /* Family check from __inet6_bind() */
4736 goto err_af;
4737 }
4738 /* see __inet_bind(), we only want to allow
4739 * AF_UNSPEC if the address is INADDR_ANY
4740 */
4741 if (addr4->sin_addr.s_addr != htonl(INADDR_ANY))
4742 goto err_af;
4743 family_sa = AF_INET;
4744 }
4745 snum = ntohs(addr4->sin_port);
4746 addrp = (char *)&addr4->sin_addr.s_addr;
4747 break;
4748 case AF_INET6:
4749 if (addrlen < SIN6_LEN_RFC2133)
4750 return -EINVAL;
4751 addr6 = (struct sockaddr_in6 *)address;
4752 snum = ntohs(addr6->sin6_port);
4753 addrp = (char *)&addr6->sin6_addr.s6_addr;
4754 break;
4755 default:
4756 goto err_af;
4757 }
4758
4759 ad.type = LSM_AUDIT_DATA_NET;
4760 ad.u.net = &net;
4761 ad.u.net->sport = htons(snum);
4762 ad.u.net->family = family_sa;
4763
4764 if (snum) {
4765 int low, high;
4766
4767 inet_get_local_port_range(sock_net(sk), &low, &high);
4768
4769 if (inet_port_requires_bind_service(sock_net(sk), snum) ||
4770 snum < low || snum > high) {
4771 err = sel_netport_sid(sk->sk_protocol,
4772 snum, &sid);
4773 if (err)
4774 goto out;
4775 err = avc_has_perm(sksec->sid, sid,
4776 sksec->sclass,
4777 SOCKET__NAME_BIND, &ad);
4778 if (err)
4779 goto out;
4780 }
4781 }
4782
4783 switch (sksec->sclass) {
4784 case SECCLASS_TCP_SOCKET:
4785 node_perm = TCP_SOCKET__NODE_BIND;
4786 break;
4787
4788 case SECCLASS_UDP_SOCKET:
4789 node_perm = UDP_SOCKET__NODE_BIND;
4790 break;
4791
4792 case SECCLASS_DCCP_SOCKET:
4793 node_perm = DCCP_SOCKET__NODE_BIND;
4794 break;
4795
4796 case SECCLASS_SCTP_SOCKET:
4797 node_perm = SCTP_SOCKET__NODE_BIND;
4798 break;
4799
4800 default:
4801 node_perm = RAWIP_SOCKET__NODE_BIND;
4802 break;
4803 }
4804
4805 err = sel_netnode_sid(addrp, family_sa, &sid);
4806 if (err)
4807 goto out;
4808
4809 if (family_sa == AF_INET)
4810 ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
4811 else
4812 ad.u.net->v6info.saddr = addr6->sin6_addr;
4813
4814 err = avc_has_perm(sksec->sid, sid,
4815 sksec->sclass, node_perm, &ad);
4816 if (err)
4817 goto out;
4818 }
4819 out:
4820 return err;
4821 err_af:
4822 /* Note that SCTP services expect -EINVAL, others -EAFNOSUPPORT. */
4823 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4824 return -EINVAL;
4825 return -EAFNOSUPPORT;
4826 }
4827
4828 /* This supports connect(2) and SCTP connect services such as sctp_connectx(3)
4829 * and sctp_sendmsg(3) as described in Documentation/security/SCTP.rst
4830 */
selinux_socket_connect_helper(struct socket * sock,struct sockaddr * address,int addrlen)4831 static int selinux_socket_connect_helper(struct socket *sock,
4832 struct sockaddr *address, int addrlen)
4833 {
4834 struct sock *sk = sock->sk;
4835 struct sk_security_struct *sksec = selinux_sock(sk);
4836 int err;
4837
4838 err = sock_has_perm(sk, SOCKET__CONNECT);
4839 if (err)
4840 return err;
4841 if (addrlen < offsetofend(struct sockaddr, sa_family))
4842 return -EINVAL;
4843
4844 /* connect(AF_UNSPEC) has special handling, as it is a documented
4845 * way to disconnect the socket
4846 */
4847 if (address->sa_family == AF_UNSPEC)
4848 return 0;
4849
4850 /*
4851 * If a TCP, DCCP or SCTP socket, check name_connect permission
4852 * for the port.
4853 */
4854 if (sksec->sclass == SECCLASS_TCP_SOCKET ||
4855 sksec->sclass == SECCLASS_DCCP_SOCKET ||
4856 sksec->sclass == SECCLASS_SCTP_SOCKET) {
4857 struct common_audit_data ad;
4858 struct lsm_network_audit net = {0,};
4859 struct sockaddr_in *addr4 = NULL;
4860 struct sockaddr_in6 *addr6 = NULL;
4861 unsigned short snum;
4862 u32 sid, perm;
4863
4864 /* sctp_connectx(3) calls via selinux_sctp_bind_connect()
4865 * that validates multiple connect addresses. Because of this
4866 * need to check address->sa_family as it is possible to have
4867 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4868 */
4869 switch (address->sa_family) {
4870 case AF_INET:
4871 addr4 = (struct sockaddr_in *)address;
4872 if (addrlen < sizeof(struct sockaddr_in))
4873 return -EINVAL;
4874 snum = ntohs(addr4->sin_port);
4875 break;
4876 case AF_INET6:
4877 addr6 = (struct sockaddr_in6 *)address;
4878 if (addrlen < SIN6_LEN_RFC2133)
4879 return -EINVAL;
4880 snum = ntohs(addr6->sin6_port);
4881 break;
4882 default:
4883 /* Note that SCTP services expect -EINVAL, whereas
4884 * others expect -EAFNOSUPPORT.
4885 */
4886 if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4887 return -EINVAL;
4888 else
4889 return -EAFNOSUPPORT;
4890 }
4891
4892 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
4893 if (err)
4894 return err;
4895
4896 switch (sksec->sclass) {
4897 case SECCLASS_TCP_SOCKET:
4898 perm = TCP_SOCKET__NAME_CONNECT;
4899 break;
4900 case SECCLASS_DCCP_SOCKET:
4901 perm = DCCP_SOCKET__NAME_CONNECT;
4902 break;
4903 case SECCLASS_SCTP_SOCKET:
4904 perm = SCTP_SOCKET__NAME_CONNECT;
4905 break;
4906 }
4907
4908 ad.type = LSM_AUDIT_DATA_NET;
4909 ad.u.net = &net;
4910 ad.u.net->dport = htons(snum);
4911 ad.u.net->family = address->sa_family;
4912 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
4913 if (err)
4914 return err;
4915 }
4916
4917 return 0;
4918 }
4919
4920 /* Supports connect(2), see comments in selinux_socket_connect_helper() */
selinux_socket_connect(struct socket * sock,struct sockaddr * address,int addrlen)4921 static int selinux_socket_connect(struct socket *sock,
4922 struct sockaddr *address, int addrlen)
4923 {
4924 int err;
4925 struct sock *sk = sock->sk;
4926
4927 err = selinux_socket_connect_helper(sock, address, addrlen);
4928 if (err)
4929 return err;
4930
4931 return selinux_netlbl_socket_connect(sk, address);
4932 }
4933
selinux_socket_listen(struct socket * sock,int backlog)4934 static int selinux_socket_listen(struct socket *sock, int backlog)
4935 {
4936 return sock_has_perm(sock->sk, SOCKET__LISTEN);
4937 }
4938
selinux_socket_accept(struct socket * sock,struct socket * newsock)4939 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
4940 {
4941 int err;
4942 struct inode_security_struct *isec;
4943 struct inode_security_struct *newisec;
4944 u16 sclass;
4945 u32 sid;
4946
4947 err = sock_has_perm(sock->sk, SOCKET__ACCEPT);
4948 if (err)
4949 return err;
4950
4951 isec = inode_security_novalidate(SOCK_INODE(sock));
4952 spin_lock(&isec->lock);
4953 sclass = isec->sclass;
4954 sid = isec->sid;
4955 spin_unlock(&isec->lock);
4956
4957 newisec = inode_security_novalidate(SOCK_INODE(newsock));
4958 newisec->sclass = sclass;
4959 newisec->sid = sid;
4960 newisec->initialized = LABEL_INITIALIZED;
4961
4962 return 0;
4963 }
4964
selinux_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)4965 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4966 int size)
4967 {
4968 return sock_has_perm(sock->sk, SOCKET__WRITE);
4969 }
4970
selinux_socket_recvmsg(struct socket * sock,struct msghdr * msg,int size,int flags)4971 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4972 int size, int flags)
4973 {
4974 return sock_has_perm(sock->sk, SOCKET__READ);
4975 }
4976
selinux_socket_getsockname(struct socket * sock)4977 static int selinux_socket_getsockname(struct socket *sock)
4978 {
4979 return sock_has_perm(sock->sk, SOCKET__GETATTR);
4980 }
4981
selinux_socket_getpeername(struct socket * sock)4982 static int selinux_socket_getpeername(struct socket *sock)
4983 {
4984 return sock_has_perm(sock->sk, SOCKET__GETATTR);
4985 }
4986
selinux_socket_setsockopt(struct socket * sock,int level,int optname)4987 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4988 {
4989 int err;
4990
4991 err = sock_has_perm(sock->sk, SOCKET__SETOPT);
4992 if (err)
4993 return err;
4994
4995 return selinux_netlbl_socket_setsockopt(sock, level, optname);
4996 }
4997
selinux_socket_getsockopt(struct socket * sock,int level,int optname)4998 static int selinux_socket_getsockopt(struct socket *sock, int level,
4999 int optname)
5000 {
5001 return sock_has_perm(sock->sk, SOCKET__GETOPT);
5002 }
5003
selinux_socket_shutdown(struct socket * sock,int how)5004 static int selinux_socket_shutdown(struct socket *sock, int how)
5005 {
5006 return sock_has_perm(sock->sk, SOCKET__SHUTDOWN);
5007 }
5008
selinux_socket_unix_stream_connect(struct sock * sock,struct sock * other,struct sock * newsk)5009 static int selinux_socket_unix_stream_connect(struct sock *sock,
5010 struct sock *other,
5011 struct sock *newsk)
5012 {
5013 struct sk_security_struct *sksec_sock = selinux_sock(sock);
5014 struct sk_security_struct *sksec_other = selinux_sock(other);
5015 struct sk_security_struct *sksec_new = selinux_sock(newsk);
5016 struct common_audit_data ad;
5017 struct lsm_network_audit net;
5018 int err;
5019
5020 ad_net_init_from_sk(&ad, &net, other);
5021
5022 err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
5023 sksec_other->sclass,
5024 UNIX_STREAM_SOCKET__CONNECTTO, &ad);
5025 if (err)
5026 return err;
5027
5028 /* server child socket */
5029 sksec_new->peer_sid = sksec_sock->sid;
5030 err = security_sid_mls_copy(sksec_other->sid,
5031 sksec_sock->sid, &sksec_new->sid);
5032 if (err)
5033 return err;
5034
5035 /* connecting socket */
5036 sksec_sock->peer_sid = sksec_new->sid;
5037
5038 return 0;
5039 }
5040
selinux_socket_unix_may_send(struct socket * sock,struct socket * other)5041 static int selinux_socket_unix_may_send(struct socket *sock,
5042 struct socket *other)
5043 {
5044 struct sk_security_struct *ssec = selinux_sock(sock->sk);
5045 struct sk_security_struct *osec = selinux_sock(other->sk);
5046 struct common_audit_data ad;
5047 struct lsm_network_audit net;
5048
5049 ad_net_init_from_sk(&ad, &net, other->sk);
5050
5051 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
5052 &ad);
5053 }
5054
selinux_inet_sys_rcv_skb(struct net * ns,int ifindex,char * addrp,u16 family,u32 peer_sid,struct common_audit_data * ad)5055 static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
5056 char *addrp, u16 family, u32 peer_sid,
5057 struct common_audit_data *ad)
5058 {
5059 int err;
5060 u32 if_sid;
5061 u32 node_sid;
5062
5063 err = sel_netif_sid(ns, ifindex, &if_sid);
5064 if (err)
5065 return err;
5066 err = avc_has_perm(peer_sid, if_sid,
5067 SECCLASS_NETIF, NETIF__INGRESS, ad);
5068 if (err)
5069 return err;
5070
5071 err = sel_netnode_sid(addrp, family, &node_sid);
5072 if (err)
5073 return err;
5074 return avc_has_perm(peer_sid, node_sid,
5075 SECCLASS_NODE, NODE__RECVFROM, ad);
5076 }
5077
selinux_sock_rcv_skb_compat(struct sock * sk,struct sk_buff * skb,u16 family)5078 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
5079 u16 family)
5080 {
5081 int err = 0;
5082 struct sk_security_struct *sksec = selinux_sock(sk);
5083 u32 sk_sid = sksec->sid;
5084 struct common_audit_data ad;
5085 struct lsm_network_audit net;
5086 char *addrp;
5087
5088 ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
5089 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5090 if (err)
5091 return err;
5092
5093 if (selinux_secmark_enabled()) {
5094 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
5095 PACKET__RECV, &ad);
5096 if (err)
5097 return err;
5098 }
5099
5100 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
5101 if (err)
5102 return err;
5103 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
5104
5105 return err;
5106 }
5107
selinux_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)5108 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
5109 {
5110 int err, peerlbl_active, secmark_active;
5111 struct sk_security_struct *sksec = selinux_sock(sk);
5112 u16 family = sk->sk_family;
5113 u32 sk_sid = sksec->sid;
5114 struct common_audit_data ad;
5115 struct lsm_network_audit net;
5116 char *addrp;
5117
5118 if (family != PF_INET && family != PF_INET6)
5119 return 0;
5120
5121 /* Handle mapped IPv4 packets arriving via IPv6 sockets */
5122 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5123 family = PF_INET;
5124
5125 /* If any sort of compatibility mode is enabled then handoff processing
5126 * to the selinux_sock_rcv_skb_compat() function to deal with the
5127 * special handling. We do this in an attempt to keep this function
5128 * as fast and as clean as possible. */
5129 if (!selinux_policycap_netpeer())
5130 return selinux_sock_rcv_skb_compat(sk, skb, family);
5131
5132 secmark_active = selinux_secmark_enabled();
5133 peerlbl_active = selinux_peerlbl_enabled();
5134 if (!secmark_active && !peerlbl_active)
5135 return 0;
5136
5137 ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
5138 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5139 if (err)
5140 return err;
5141
5142 if (peerlbl_active) {
5143 u32 peer_sid;
5144
5145 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
5146 if (err)
5147 return err;
5148 err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
5149 addrp, family, peer_sid, &ad);
5150 if (err) {
5151 selinux_netlbl_err(skb, family, err, 0);
5152 return err;
5153 }
5154 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
5155 PEER__RECV, &ad);
5156 if (err) {
5157 selinux_netlbl_err(skb, family, err, 0);
5158 return err;
5159 }
5160 }
5161
5162 if (secmark_active) {
5163 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
5164 PACKET__RECV, &ad);
5165 if (err)
5166 return err;
5167 }
5168
5169 return err;
5170 }
5171
selinux_socket_getpeersec_stream(struct socket * sock,sockptr_t optval,sockptr_t optlen,unsigned int len)5172 static int selinux_socket_getpeersec_stream(struct socket *sock,
5173 sockptr_t optval, sockptr_t optlen,
5174 unsigned int len)
5175 {
5176 int err = 0;
5177 char *scontext = NULL;
5178 u32 scontext_len;
5179 struct sk_security_struct *sksec = selinux_sock(sock->sk);
5180 u32 peer_sid = SECSID_NULL;
5181
5182 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
5183 sksec->sclass == SECCLASS_TCP_SOCKET ||
5184 sksec->sclass == SECCLASS_SCTP_SOCKET)
5185 peer_sid = sksec->peer_sid;
5186 if (peer_sid == SECSID_NULL)
5187 return -ENOPROTOOPT;
5188
5189 err = security_sid_to_context(peer_sid, &scontext,
5190 &scontext_len);
5191 if (err)
5192 return err;
5193 if (scontext_len > len) {
5194 err = -ERANGE;
5195 goto out_len;
5196 }
5197
5198 if (copy_to_sockptr(optval, scontext, scontext_len))
5199 err = -EFAULT;
5200 out_len:
5201 if (copy_to_sockptr(optlen, &scontext_len, sizeof(scontext_len)))
5202 err = -EFAULT;
5203 kfree(scontext);
5204 return err;
5205 }
5206
selinux_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)5207 static int selinux_socket_getpeersec_dgram(struct socket *sock,
5208 struct sk_buff *skb, u32 *secid)
5209 {
5210 u32 peer_secid = SECSID_NULL;
5211 u16 family;
5212
5213 if (skb && skb->protocol == htons(ETH_P_IP))
5214 family = PF_INET;
5215 else if (skb && skb->protocol == htons(ETH_P_IPV6))
5216 family = PF_INET6;
5217 else if (sock)
5218 family = sock->sk->sk_family;
5219 else {
5220 *secid = SECSID_NULL;
5221 return -EINVAL;
5222 }
5223
5224 if (sock && family == PF_UNIX) {
5225 struct inode_security_struct *isec;
5226 isec = inode_security_novalidate(SOCK_INODE(sock));
5227 peer_secid = isec->sid;
5228 } else if (skb)
5229 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
5230
5231 *secid = peer_secid;
5232 if (peer_secid == SECSID_NULL)
5233 return -ENOPROTOOPT;
5234 return 0;
5235 }
5236
selinux_sk_alloc_security(struct sock * sk,int family,gfp_t priority)5237 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
5238 {
5239 struct sk_security_struct *sksec = selinux_sock(sk);
5240
5241 sksec->peer_sid = SECINITSID_UNLABELED;
5242 sksec->sid = SECINITSID_UNLABELED;
5243 sksec->sclass = SECCLASS_SOCKET;
5244 selinux_netlbl_sk_security_reset(sksec);
5245
5246 return 0;
5247 }
5248
selinux_sk_free_security(struct sock * sk)5249 static void selinux_sk_free_security(struct sock *sk)
5250 {
5251 struct sk_security_struct *sksec = selinux_sock(sk);
5252
5253 selinux_netlbl_sk_security_free(sksec);
5254 }
5255
selinux_sk_clone_security(const struct sock * sk,struct sock * newsk)5256 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
5257 {
5258 struct sk_security_struct *sksec = selinux_sock(sk);
5259 struct sk_security_struct *newsksec = selinux_sock(newsk);
5260
5261 newsksec->sid = sksec->sid;
5262 newsksec->peer_sid = sksec->peer_sid;
5263 newsksec->sclass = sksec->sclass;
5264
5265 selinux_netlbl_sk_security_reset(newsksec);
5266 }
5267
selinux_sk_getsecid(const struct sock * sk,u32 * secid)5268 static void selinux_sk_getsecid(const struct sock *sk, u32 *secid)
5269 {
5270 if (!sk)
5271 *secid = SECINITSID_ANY_SOCKET;
5272 else {
5273 const struct sk_security_struct *sksec = selinux_sock(sk);
5274
5275 *secid = sksec->sid;
5276 }
5277 }
5278
selinux_sock_graft(struct sock * sk,struct socket * parent)5279 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
5280 {
5281 struct inode_security_struct *isec =
5282 inode_security_novalidate(SOCK_INODE(parent));
5283 struct sk_security_struct *sksec = selinux_sock(sk);
5284
5285 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
5286 sk->sk_family == PF_UNIX)
5287 isec->sid = sksec->sid;
5288 sksec->sclass = isec->sclass;
5289 }
5290
5291 /*
5292 * Determines peer_secid for the asoc and updates socket's peer label
5293 * if it's the first association on the socket.
5294 */
selinux_sctp_process_new_assoc(struct sctp_association * asoc,struct sk_buff * skb)5295 static int selinux_sctp_process_new_assoc(struct sctp_association *asoc,
5296 struct sk_buff *skb)
5297 {
5298 struct sock *sk = asoc->base.sk;
5299 u16 family = sk->sk_family;
5300 struct sk_security_struct *sksec = selinux_sock(sk);
5301 struct common_audit_data ad;
5302 struct lsm_network_audit net;
5303 int err;
5304
5305 /* handle mapped IPv4 packets arriving via IPv6 sockets */
5306 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5307 family = PF_INET;
5308
5309 if (selinux_peerlbl_enabled()) {
5310 asoc->peer_secid = SECSID_NULL;
5311
5312 /* This will return peer_sid = SECSID_NULL if there are
5313 * no peer labels, see security_net_peersid_resolve().
5314 */
5315 err = selinux_skb_peerlbl_sid(skb, family, &asoc->peer_secid);
5316 if (err)
5317 return err;
5318
5319 if (asoc->peer_secid == SECSID_NULL)
5320 asoc->peer_secid = SECINITSID_UNLABELED;
5321 } else {
5322 asoc->peer_secid = SECINITSID_UNLABELED;
5323 }
5324
5325 if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) {
5326 sksec->sctp_assoc_state = SCTP_ASSOC_SET;
5327
5328 /* Here as first association on socket. As the peer SID
5329 * was allowed by peer recv (and the netif/node checks),
5330 * then it is approved by policy and used as the primary
5331 * peer SID for getpeercon(3).
5332 */
5333 sksec->peer_sid = asoc->peer_secid;
5334 } else if (sksec->peer_sid != asoc->peer_secid) {
5335 /* Other association peer SIDs are checked to enforce
5336 * consistency among the peer SIDs.
5337 */
5338 ad_net_init_from_sk(&ad, &net, asoc->base.sk);
5339 err = avc_has_perm(sksec->peer_sid, asoc->peer_secid,
5340 sksec->sclass, SCTP_SOCKET__ASSOCIATION,
5341 &ad);
5342 if (err)
5343 return err;
5344 }
5345 return 0;
5346 }
5347
5348 /* Called whenever SCTP receives an INIT or COOKIE ECHO chunk. This
5349 * happens on an incoming connect(2), sctp_connectx(3) or
5350 * sctp_sendmsg(3) (with no association already present).
5351 */
selinux_sctp_assoc_request(struct sctp_association * asoc,struct sk_buff * skb)5352 static int selinux_sctp_assoc_request(struct sctp_association *asoc,
5353 struct sk_buff *skb)
5354 {
5355 struct sk_security_struct *sksec = selinux_sock(asoc->base.sk);
5356 u32 conn_sid;
5357 int err;
5358
5359 if (!selinux_policycap_extsockclass())
5360 return 0;
5361
5362 err = selinux_sctp_process_new_assoc(asoc, skb);
5363 if (err)
5364 return err;
5365
5366 /* Compute the MLS component for the connection and store
5367 * the information in asoc. This will be used by SCTP TCP type
5368 * sockets and peeled off connections as they cause a new
5369 * socket to be generated. selinux_sctp_sk_clone() will then
5370 * plug this into the new socket.
5371 */
5372 err = selinux_conn_sid(sksec->sid, asoc->peer_secid, &conn_sid);
5373 if (err)
5374 return err;
5375
5376 asoc->secid = conn_sid;
5377
5378 /* Set any NetLabel labels including CIPSO/CALIPSO options. */
5379 return selinux_netlbl_sctp_assoc_request(asoc, skb);
5380 }
5381
5382 /* Called when SCTP receives a COOKIE ACK chunk as the final
5383 * response to an association request (initited by us).
5384 */
selinux_sctp_assoc_established(struct sctp_association * asoc,struct sk_buff * skb)5385 static int selinux_sctp_assoc_established(struct sctp_association *asoc,
5386 struct sk_buff *skb)
5387 {
5388 struct sk_security_struct *sksec = selinux_sock(asoc->base.sk);
5389
5390 if (!selinux_policycap_extsockclass())
5391 return 0;
5392
5393 /* Inherit secid from the parent socket - this will be picked up
5394 * by selinux_sctp_sk_clone() if the association gets peeled off
5395 * into a new socket.
5396 */
5397 asoc->secid = sksec->sid;
5398
5399 return selinux_sctp_process_new_assoc(asoc, skb);
5400 }
5401
5402 /* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
5403 * based on their @optname.
5404 */
selinux_sctp_bind_connect(struct sock * sk,int optname,struct sockaddr * address,int addrlen)5405 static int selinux_sctp_bind_connect(struct sock *sk, int optname,
5406 struct sockaddr *address,
5407 int addrlen)
5408 {
5409 int len, err = 0, walk_size = 0;
5410 void *addr_buf;
5411 struct sockaddr *addr;
5412 struct socket *sock;
5413
5414 if (!selinux_policycap_extsockclass())
5415 return 0;
5416
5417 /* Process one or more addresses that may be IPv4 or IPv6 */
5418 sock = sk->sk_socket;
5419 addr_buf = address;
5420
5421 while (walk_size < addrlen) {
5422 if (walk_size + sizeof(sa_family_t) > addrlen)
5423 return -EINVAL;
5424
5425 addr = addr_buf;
5426 switch (addr->sa_family) {
5427 case AF_UNSPEC:
5428 case AF_INET:
5429 len = sizeof(struct sockaddr_in);
5430 break;
5431 case AF_INET6:
5432 len = sizeof(struct sockaddr_in6);
5433 break;
5434 default:
5435 return -EINVAL;
5436 }
5437
5438 if (walk_size + len > addrlen)
5439 return -EINVAL;
5440
5441 err = -EINVAL;
5442 switch (optname) {
5443 /* Bind checks */
5444 case SCTP_PRIMARY_ADDR:
5445 case SCTP_SET_PEER_PRIMARY_ADDR:
5446 case SCTP_SOCKOPT_BINDX_ADD:
5447 err = selinux_socket_bind(sock, addr, len);
5448 break;
5449 /* Connect checks */
5450 case SCTP_SOCKOPT_CONNECTX:
5451 case SCTP_PARAM_SET_PRIMARY:
5452 case SCTP_PARAM_ADD_IP:
5453 case SCTP_SENDMSG_CONNECT:
5454 err = selinux_socket_connect_helper(sock, addr, len);
5455 if (err)
5456 return err;
5457
5458 /* As selinux_sctp_bind_connect() is called by the
5459 * SCTP protocol layer, the socket is already locked,
5460 * therefore selinux_netlbl_socket_connect_locked()
5461 * is called here. The situations handled are:
5462 * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2),
5463 * whenever a new IP address is added or when a new
5464 * primary address is selected.
5465 * Note that an SCTP connect(2) call happens before
5466 * the SCTP protocol layer and is handled via
5467 * selinux_socket_connect().
5468 */
5469 err = selinux_netlbl_socket_connect_locked(sk, addr);
5470 break;
5471 }
5472
5473 if (err)
5474 return err;
5475
5476 addr_buf += len;
5477 walk_size += len;
5478 }
5479
5480 return 0;
5481 }
5482
5483 /* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */
selinux_sctp_sk_clone(struct sctp_association * asoc,struct sock * sk,struct sock * newsk)5484 static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk,
5485 struct sock *newsk)
5486 {
5487 struct sk_security_struct *sksec = selinux_sock(sk);
5488 struct sk_security_struct *newsksec = selinux_sock(newsk);
5489
5490 /* If policy does not support SECCLASS_SCTP_SOCKET then call
5491 * the non-sctp clone version.
5492 */
5493 if (!selinux_policycap_extsockclass())
5494 return selinux_sk_clone_security(sk, newsk);
5495
5496 newsksec->sid = asoc->secid;
5497 newsksec->peer_sid = asoc->peer_secid;
5498 newsksec->sclass = sksec->sclass;
5499 selinux_netlbl_sctp_sk_clone(sk, newsk);
5500 }
5501
selinux_mptcp_add_subflow(struct sock * sk,struct sock * ssk)5502 static int selinux_mptcp_add_subflow(struct sock *sk, struct sock *ssk)
5503 {
5504 struct sk_security_struct *ssksec = selinux_sock(ssk);
5505 struct sk_security_struct *sksec = selinux_sock(sk);
5506
5507 ssksec->sclass = sksec->sclass;
5508 ssksec->sid = sksec->sid;
5509
5510 /* replace the existing subflow label deleting the existing one
5511 * and re-recreating a new label using the updated context
5512 */
5513 selinux_netlbl_sk_security_free(ssksec);
5514 return selinux_netlbl_socket_post_create(ssk, ssk->sk_family);
5515 }
5516
selinux_inet_conn_request(const struct sock * sk,struct sk_buff * skb,struct request_sock * req)5517 static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
5518 struct request_sock *req)
5519 {
5520 struct sk_security_struct *sksec = selinux_sock(sk);
5521 int err;
5522 u16 family = req->rsk_ops->family;
5523 u32 connsid;
5524 u32 peersid;
5525
5526 err = selinux_skb_peerlbl_sid(skb, family, &peersid);
5527 if (err)
5528 return err;
5529 err = selinux_conn_sid(sksec->sid, peersid, &connsid);
5530 if (err)
5531 return err;
5532 req->secid = connsid;
5533 req->peer_secid = peersid;
5534
5535 return selinux_netlbl_inet_conn_request(req, family);
5536 }
5537
selinux_inet_csk_clone(struct sock * newsk,const struct request_sock * req)5538 static void selinux_inet_csk_clone(struct sock *newsk,
5539 const struct request_sock *req)
5540 {
5541 struct sk_security_struct *newsksec = selinux_sock(newsk);
5542
5543 newsksec->sid = req->secid;
5544 newsksec->peer_sid = req->peer_secid;
5545 /* NOTE: Ideally, we should also get the isec->sid for the
5546 new socket in sync, but we don't have the isec available yet.
5547 So we will wait until sock_graft to do it, by which
5548 time it will have been created and available. */
5549
5550 /* We don't need to take any sort of lock here as we are the only
5551 * thread with access to newsksec */
5552 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
5553 }
5554
selinux_inet_conn_established(struct sock * sk,struct sk_buff * skb)5555 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
5556 {
5557 u16 family = sk->sk_family;
5558 struct sk_security_struct *sksec = selinux_sock(sk);
5559
5560 /* handle mapped IPv4 packets arriving via IPv6 sockets */
5561 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5562 family = PF_INET;
5563
5564 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
5565 }
5566
selinux_secmark_relabel_packet(u32 sid)5567 static int selinux_secmark_relabel_packet(u32 sid)
5568 {
5569 return avc_has_perm(current_sid(), sid, SECCLASS_PACKET, PACKET__RELABELTO,
5570 NULL);
5571 }
5572
selinux_secmark_refcount_inc(void)5573 static void selinux_secmark_refcount_inc(void)
5574 {
5575 atomic_inc(&selinux_secmark_refcount);
5576 }
5577
selinux_secmark_refcount_dec(void)5578 static void selinux_secmark_refcount_dec(void)
5579 {
5580 atomic_dec(&selinux_secmark_refcount);
5581 }
5582
selinux_req_classify_flow(const struct request_sock * req,struct flowi_common * flic)5583 static void selinux_req_classify_flow(const struct request_sock *req,
5584 struct flowi_common *flic)
5585 {
5586 flic->flowic_secid = req->secid;
5587 }
5588
selinux_tun_dev_alloc_security(void * security)5589 static int selinux_tun_dev_alloc_security(void *security)
5590 {
5591 struct tun_security_struct *tunsec = selinux_tun_dev(security);
5592
5593 tunsec->sid = current_sid();
5594 return 0;
5595 }
5596
selinux_tun_dev_create(void)5597 static int selinux_tun_dev_create(void)
5598 {
5599 u32 sid = current_sid();
5600
5601 /* we aren't taking into account the "sockcreate" SID since the socket
5602 * that is being created here is not a socket in the traditional sense,
5603 * instead it is a private sock, accessible only to the kernel, and
5604 * representing a wide range of network traffic spanning multiple
5605 * connections unlike traditional sockets - check the TUN driver to
5606 * get a better understanding of why this socket is special */
5607
5608 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
5609 NULL);
5610 }
5611
selinux_tun_dev_attach_queue(void * security)5612 static int selinux_tun_dev_attach_queue(void *security)
5613 {
5614 struct tun_security_struct *tunsec = selinux_tun_dev(security);
5615
5616 return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
5617 TUN_SOCKET__ATTACH_QUEUE, NULL);
5618 }
5619
selinux_tun_dev_attach(struct sock * sk,void * security)5620 static int selinux_tun_dev_attach(struct sock *sk, void *security)
5621 {
5622 struct tun_security_struct *tunsec = selinux_tun_dev(security);
5623 struct sk_security_struct *sksec = selinux_sock(sk);
5624
5625 /* we don't currently perform any NetLabel based labeling here and it
5626 * isn't clear that we would want to do so anyway; while we could apply
5627 * labeling without the support of the TUN user the resulting labeled
5628 * traffic from the other end of the connection would almost certainly
5629 * cause confusion to the TUN user that had no idea network labeling
5630 * protocols were being used */
5631
5632 sksec->sid = tunsec->sid;
5633 sksec->sclass = SECCLASS_TUN_SOCKET;
5634
5635 return 0;
5636 }
5637
selinux_tun_dev_open(void * security)5638 static int selinux_tun_dev_open(void *security)
5639 {
5640 struct tun_security_struct *tunsec = selinux_tun_dev(security);
5641 u32 sid = current_sid();
5642 int err;
5643
5644 err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
5645 TUN_SOCKET__RELABELFROM, NULL);
5646 if (err)
5647 return err;
5648 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
5649 TUN_SOCKET__RELABELTO, NULL);
5650 if (err)
5651 return err;
5652 tunsec->sid = sid;
5653
5654 return 0;
5655 }
5656
5657 #ifdef CONFIG_NETFILTER
5658
selinux_ip_forward(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5659 static unsigned int selinux_ip_forward(void *priv, struct sk_buff *skb,
5660 const struct nf_hook_state *state)
5661 {
5662 int ifindex;
5663 u16 family;
5664 char *addrp;
5665 u32 peer_sid;
5666 struct common_audit_data ad;
5667 struct lsm_network_audit net;
5668 int secmark_active, peerlbl_active;
5669
5670 if (!selinux_policycap_netpeer())
5671 return NF_ACCEPT;
5672
5673 secmark_active = selinux_secmark_enabled();
5674 peerlbl_active = selinux_peerlbl_enabled();
5675 if (!secmark_active && !peerlbl_active)
5676 return NF_ACCEPT;
5677
5678 family = state->pf;
5679 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
5680 return NF_DROP;
5681
5682 ifindex = state->in->ifindex;
5683 ad_net_init_from_iif(&ad, &net, ifindex, family);
5684 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
5685 return NF_DROP;
5686
5687 if (peerlbl_active) {
5688 int err;
5689
5690 err = selinux_inet_sys_rcv_skb(state->net, ifindex,
5691 addrp, family, peer_sid, &ad);
5692 if (err) {
5693 selinux_netlbl_err(skb, family, err, 1);
5694 return NF_DROP;
5695 }
5696 }
5697
5698 if (secmark_active)
5699 if (avc_has_perm(peer_sid, skb->secmark,
5700 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
5701 return NF_DROP;
5702
5703 if (netlbl_enabled())
5704 /* we do this in the FORWARD path and not the POST_ROUTING
5705 * path because we want to make sure we apply the necessary
5706 * labeling before IPsec is applied so we can leverage AH
5707 * protection */
5708 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
5709 return NF_DROP;
5710
5711 return NF_ACCEPT;
5712 }
5713
selinux_ip_output(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5714 static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb,
5715 const struct nf_hook_state *state)
5716 {
5717 struct sock *sk;
5718 u32 sid;
5719
5720 if (!netlbl_enabled())
5721 return NF_ACCEPT;
5722
5723 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
5724 * because we want to make sure we apply the necessary labeling
5725 * before IPsec is applied so we can leverage AH protection */
5726 sk = skb->sk;
5727 if (sk) {
5728 struct sk_security_struct *sksec;
5729
5730 if (sk_listener(sk))
5731 /* if the socket is the listening state then this
5732 * packet is a SYN-ACK packet which means it needs to
5733 * be labeled based on the connection/request_sock and
5734 * not the parent socket. unfortunately, we can't
5735 * lookup the request_sock yet as it isn't queued on
5736 * the parent socket until after the SYN-ACK is sent.
5737 * the "solution" is to simply pass the packet as-is
5738 * as any IP option based labeling should be copied
5739 * from the initial connection request (in the IP
5740 * layer). it is far from ideal, but until we get a
5741 * security label in the packet itself this is the
5742 * best we can do. */
5743 return NF_ACCEPT;
5744
5745 /* standard practice, label using the parent socket */
5746 sksec = selinux_sock(sk);
5747 sid = sksec->sid;
5748 } else
5749 sid = SECINITSID_KERNEL;
5750 if (selinux_netlbl_skbuff_setsid(skb, state->pf, sid) != 0)
5751 return NF_DROP;
5752
5753 return NF_ACCEPT;
5754 }
5755
5756
selinux_ip_postroute_compat(struct sk_buff * skb,const struct nf_hook_state * state)5757 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
5758 const struct nf_hook_state *state)
5759 {
5760 struct sock *sk;
5761 struct sk_security_struct *sksec;
5762 struct common_audit_data ad;
5763 struct lsm_network_audit net;
5764 u8 proto = 0;
5765
5766 sk = skb_to_full_sk(skb);
5767 if (sk == NULL)
5768 return NF_ACCEPT;
5769 sksec = selinux_sock(sk);
5770
5771 ad_net_init_from_iif(&ad, &net, state->out->ifindex, state->pf);
5772 if (selinux_parse_skb(skb, &ad, NULL, 0, &proto))
5773 return NF_DROP;
5774
5775 if (selinux_secmark_enabled())
5776 if (avc_has_perm(sksec->sid, skb->secmark,
5777 SECCLASS_PACKET, PACKET__SEND, &ad))
5778 return NF_DROP_ERR(-ECONNREFUSED);
5779
5780 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
5781 return NF_DROP_ERR(-ECONNREFUSED);
5782
5783 return NF_ACCEPT;
5784 }
5785
selinux_ip_postroute(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5786 static unsigned int selinux_ip_postroute(void *priv,
5787 struct sk_buff *skb,
5788 const struct nf_hook_state *state)
5789 {
5790 u16 family;
5791 u32 secmark_perm;
5792 u32 peer_sid;
5793 int ifindex;
5794 struct sock *sk;
5795 struct common_audit_data ad;
5796 struct lsm_network_audit net;
5797 char *addrp;
5798 int secmark_active, peerlbl_active;
5799
5800 /* If any sort of compatibility mode is enabled then handoff processing
5801 * to the selinux_ip_postroute_compat() function to deal with the
5802 * special handling. We do this in an attempt to keep this function
5803 * as fast and as clean as possible. */
5804 if (!selinux_policycap_netpeer())
5805 return selinux_ip_postroute_compat(skb, state);
5806
5807 secmark_active = selinux_secmark_enabled();
5808 peerlbl_active = selinux_peerlbl_enabled();
5809 if (!secmark_active && !peerlbl_active)
5810 return NF_ACCEPT;
5811
5812 sk = skb_to_full_sk(skb);
5813
5814 #ifdef CONFIG_XFRM
5815 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
5816 * packet transformation so allow the packet to pass without any checks
5817 * since we'll have another chance to perform access control checks
5818 * when the packet is on it's final way out.
5819 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
5820 * is NULL, in this case go ahead and apply access control.
5821 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
5822 * TCP listening state we cannot wait until the XFRM processing
5823 * is done as we will miss out on the SA label if we do;
5824 * unfortunately, this means more work, but it is only once per
5825 * connection. */
5826 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
5827 !(sk && sk_listener(sk)))
5828 return NF_ACCEPT;
5829 #endif
5830
5831 family = state->pf;
5832 if (sk == NULL) {
5833 /* Without an associated socket the packet is either coming
5834 * from the kernel or it is being forwarded; check the packet
5835 * to determine which and if the packet is being forwarded
5836 * query the packet directly to determine the security label. */
5837 if (skb->skb_iif) {
5838 secmark_perm = PACKET__FORWARD_OUT;
5839 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5840 return NF_DROP;
5841 } else {
5842 secmark_perm = PACKET__SEND;
5843 peer_sid = SECINITSID_KERNEL;
5844 }
5845 } else if (sk_listener(sk)) {
5846 /* Locally generated packet but the associated socket is in the
5847 * listening state which means this is a SYN-ACK packet. In
5848 * this particular case the correct security label is assigned
5849 * to the connection/request_sock but unfortunately we can't
5850 * query the request_sock as it isn't queued on the parent
5851 * socket until after the SYN-ACK packet is sent; the only
5852 * viable choice is to regenerate the label like we do in
5853 * selinux_inet_conn_request(). See also selinux_ip_output()
5854 * for similar problems. */
5855 u32 skb_sid;
5856 struct sk_security_struct *sksec;
5857
5858 sksec = selinux_sock(sk);
5859 if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
5860 return NF_DROP;
5861 /* At this point, if the returned skb peerlbl is SECSID_NULL
5862 * and the packet has been through at least one XFRM
5863 * transformation then we must be dealing with the "final"
5864 * form of labeled IPsec packet; since we've already applied
5865 * all of our access controls on this packet we can safely
5866 * pass the packet. */
5867 if (skb_sid == SECSID_NULL) {
5868 switch (family) {
5869 case PF_INET:
5870 if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
5871 return NF_ACCEPT;
5872 break;
5873 case PF_INET6:
5874 if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
5875 return NF_ACCEPT;
5876 break;
5877 default:
5878 return NF_DROP_ERR(-ECONNREFUSED);
5879 }
5880 }
5881 if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
5882 return NF_DROP;
5883 secmark_perm = PACKET__SEND;
5884 } else {
5885 /* Locally generated packet, fetch the security label from the
5886 * associated socket. */
5887 struct sk_security_struct *sksec = selinux_sock(sk);
5888 peer_sid = sksec->sid;
5889 secmark_perm = PACKET__SEND;
5890 }
5891
5892 ifindex = state->out->ifindex;
5893 ad_net_init_from_iif(&ad, &net, ifindex, family);
5894 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5895 return NF_DROP;
5896
5897 if (secmark_active)
5898 if (avc_has_perm(peer_sid, skb->secmark,
5899 SECCLASS_PACKET, secmark_perm, &ad))
5900 return NF_DROP_ERR(-ECONNREFUSED);
5901
5902 if (peerlbl_active) {
5903 u32 if_sid;
5904 u32 node_sid;
5905
5906 if (sel_netif_sid(state->net, ifindex, &if_sid))
5907 return NF_DROP;
5908 if (avc_has_perm(peer_sid, if_sid,
5909 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5910 return NF_DROP_ERR(-ECONNREFUSED);
5911
5912 if (sel_netnode_sid(addrp, family, &node_sid))
5913 return NF_DROP;
5914 if (avc_has_perm(peer_sid, node_sid,
5915 SECCLASS_NODE, NODE__SENDTO, &ad))
5916 return NF_DROP_ERR(-ECONNREFUSED);
5917 }
5918
5919 return NF_ACCEPT;
5920 }
5921 #endif /* CONFIG_NETFILTER */
5922
selinux_netlink_send(struct sock * sk,struct sk_buff * skb)5923 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
5924 {
5925 int rc = 0;
5926 unsigned int msg_len;
5927 unsigned int data_len = skb->len;
5928 unsigned char *data = skb->data;
5929 struct nlmsghdr *nlh;
5930 struct sk_security_struct *sksec = selinux_sock(sk);
5931 u16 sclass = sksec->sclass;
5932 u32 perm;
5933
5934 while (data_len >= nlmsg_total_size(0)) {
5935 nlh = (struct nlmsghdr *)data;
5936
5937 /* NOTE: the nlmsg_len field isn't reliably set by some netlink
5938 * users which means we can't reject skb's with bogus
5939 * length fields; our solution is to follow what
5940 * netlink_rcv_skb() does and simply skip processing at
5941 * messages with length fields that are clearly junk
5942 */
5943 if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len)
5944 return 0;
5945
5946 rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm);
5947 if (rc == 0) {
5948 rc = sock_has_perm(sk, perm);
5949 if (rc)
5950 return rc;
5951 } else if (rc == -EINVAL) {
5952 /* -EINVAL is a missing msg/perm mapping */
5953 pr_warn_ratelimited("SELinux: unrecognized netlink"
5954 " message: protocol=%hu nlmsg_type=%hu sclass=%s"
5955 " pid=%d comm=%s\n",
5956 sk->sk_protocol, nlh->nlmsg_type,
5957 secclass_map[sclass - 1].name,
5958 task_pid_nr(current), current->comm);
5959 if (enforcing_enabled() &&
5960 !security_get_allow_unknown())
5961 return rc;
5962 rc = 0;
5963 } else if (rc == -ENOENT) {
5964 /* -ENOENT is a missing socket/class mapping, ignore */
5965 rc = 0;
5966 } else {
5967 return rc;
5968 }
5969
5970 /* move to the next message after applying netlink padding */
5971 msg_len = NLMSG_ALIGN(nlh->nlmsg_len);
5972 if (msg_len >= data_len)
5973 return 0;
5974 data_len -= msg_len;
5975 data += msg_len;
5976 }
5977
5978 return rc;
5979 }
5980
ipc_init_security(struct ipc_security_struct * isec,u16 sclass)5981 static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass)
5982 {
5983 isec->sclass = sclass;
5984 isec->sid = current_sid();
5985 }
5986
ipc_has_perm(struct kern_ipc_perm * ipc_perms,u32 perms)5987 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
5988 u32 perms)
5989 {
5990 struct ipc_security_struct *isec;
5991 struct common_audit_data ad;
5992 u32 sid = current_sid();
5993
5994 isec = selinux_ipc(ipc_perms);
5995
5996 ad.type = LSM_AUDIT_DATA_IPC;
5997 ad.u.ipc_id = ipc_perms->key;
5998
5999 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
6000 }
6001
selinux_msg_msg_alloc_security(struct msg_msg * msg)6002 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
6003 {
6004 struct msg_security_struct *msec;
6005
6006 msec = selinux_msg_msg(msg);
6007 msec->sid = SECINITSID_UNLABELED;
6008
6009 return 0;
6010 }
6011
6012 /* message queue security operations */
selinux_msg_queue_alloc_security(struct kern_ipc_perm * msq)6013 static int selinux_msg_queue_alloc_security(struct kern_ipc_perm *msq)
6014 {
6015 struct ipc_security_struct *isec;
6016 struct common_audit_data ad;
6017 u32 sid = current_sid();
6018
6019 isec = selinux_ipc(msq);
6020 ipc_init_security(isec, SECCLASS_MSGQ);
6021
6022 ad.type = LSM_AUDIT_DATA_IPC;
6023 ad.u.ipc_id = msq->key;
6024
6025 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6026 MSGQ__CREATE, &ad);
6027 }
6028
selinux_msg_queue_associate(struct kern_ipc_perm * msq,int msqflg)6029 static int selinux_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg)
6030 {
6031 struct ipc_security_struct *isec;
6032 struct common_audit_data ad;
6033 u32 sid = current_sid();
6034
6035 isec = selinux_ipc(msq);
6036
6037 ad.type = LSM_AUDIT_DATA_IPC;
6038 ad.u.ipc_id = msq->key;
6039
6040 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6041 MSGQ__ASSOCIATE, &ad);
6042 }
6043
selinux_msg_queue_msgctl(struct kern_ipc_perm * msq,int cmd)6044 static int selinux_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd)
6045 {
6046 u32 perms;
6047
6048 switch (cmd) {
6049 case IPC_INFO:
6050 case MSG_INFO:
6051 /* No specific object, just general system-wide information. */
6052 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6053 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6054 case IPC_STAT:
6055 case MSG_STAT:
6056 case MSG_STAT_ANY:
6057 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
6058 break;
6059 case IPC_SET:
6060 perms = MSGQ__SETATTR;
6061 break;
6062 case IPC_RMID:
6063 perms = MSGQ__DESTROY;
6064 break;
6065 default:
6066 return 0;
6067 }
6068
6069 return ipc_has_perm(msq, perms);
6070 }
6071
selinux_msg_queue_msgsnd(struct kern_ipc_perm * msq,struct msg_msg * msg,int msqflg)6072 static int selinux_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg, int msqflg)
6073 {
6074 struct ipc_security_struct *isec;
6075 struct msg_security_struct *msec;
6076 struct common_audit_data ad;
6077 u32 sid = current_sid();
6078 int rc;
6079
6080 isec = selinux_ipc(msq);
6081 msec = selinux_msg_msg(msg);
6082
6083 /*
6084 * First time through, need to assign label to the message
6085 */
6086 if (msec->sid == SECINITSID_UNLABELED) {
6087 /*
6088 * Compute new sid based on current process and
6089 * message queue this message will be stored in
6090 */
6091 rc = security_transition_sid(sid, isec->sid,
6092 SECCLASS_MSG, NULL, &msec->sid);
6093 if (rc)
6094 return rc;
6095 }
6096
6097 ad.type = LSM_AUDIT_DATA_IPC;
6098 ad.u.ipc_id = msq->key;
6099
6100 /* Can this process write to the queue? */
6101 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6102 MSGQ__WRITE, &ad);
6103 if (!rc)
6104 /* Can this process send the message */
6105 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
6106 MSG__SEND, &ad);
6107 if (!rc)
6108 /* Can the message be put in the queue? */
6109 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
6110 MSGQ__ENQUEUE, &ad);
6111
6112 return rc;
6113 }
6114
selinux_msg_queue_msgrcv(struct kern_ipc_perm * msq,struct msg_msg * msg,struct task_struct * target,long type,int mode)6115 static int selinux_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg,
6116 struct task_struct *target,
6117 long type, int mode)
6118 {
6119 struct ipc_security_struct *isec;
6120 struct msg_security_struct *msec;
6121 struct common_audit_data ad;
6122 u32 sid = task_sid_obj(target);
6123 int rc;
6124
6125 isec = selinux_ipc(msq);
6126 msec = selinux_msg_msg(msg);
6127
6128 ad.type = LSM_AUDIT_DATA_IPC;
6129 ad.u.ipc_id = msq->key;
6130
6131 rc = avc_has_perm(sid, isec->sid,
6132 SECCLASS_MSGQ, MSGQ__READ, &ad);
6133 if (!rc)
6134 rc = avc_has_perm(sid, msec->sid,
6135 SECCLASS_MSG, MSG__RECEIVE, &ad);
6136 return rc;
6137 }
6138
6139 /* Shared Memory security operations */
selinux_shm_alloc_security(struct kern_ipc_perm * shp)6140 static int selinux_shm_alloc_security(struct kern_ipc_perm *shp)
6141 {
6142 struct ipc_security_struct *isec;
6143 struct common_audit_data ad;
6144 u32 sid = current_sid();
6145
6146 isec = selinux_ipc(shp);
6147 ipc_init_security(isec, SECCLASS_SHM);
6148
6149 ad.type = LSM_AUDIT_DATA_IPC;
6150 ad.u.ipc_id = shp->key;
6151
6152 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
6153 SHM__CREATE, &ad);
6154 }
6155
selinux_shm_associate(struct kern_ipc_perm * shp,int shmflg)6156 static int selinux_shm_associate(struct kern_ipc_perm *shp, int shmflg)
6157 {
6158 struct ipc_security_struct *isec;
6159 struct common_audit_data ad;
6160 u32 sid = current_sid();
6161
6162 isec = selinux_ipc(shp);
6163
6164 ad.type = LSM_AUDIT_DATA_IPC;
6165 ad.u.ipc_id = shp->key;
6166
6167 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
6168 SHM__ASSOCIATE, &ad);
6169 }
6170
6171 /* Note, at this point, shp is locked down */
selinux_shm_shmctl(struct kern_ipc_perm * shp,int cmd)6172 static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd)
6173 {
6174 u32 perms;
6175
6176 switch (cmd) {
6177 case IPC_INFO:
6178 case SHM_INFO:
6179 /* No specific object, just general system-wide information. */
6180 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6181 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6182 case IPC_STAT:
6183 case SHM_STAT:
6184 case SHM_STAT_ANY:
6185 perms = SHM__GETATTR | SHM__ASSOCIATE;
6186 break;
6187 case IPC_SET:
6188 perms = SHM__SETATTR;
6189 break;
6190 case SHM_LOCK:
6191 case SHM_UNLOCK:
6192 perms = SHM__LOCK;
6193 break;
6194 case IPC_RMID:
6195 perms = SHM__DESTROY;
6196 break;
6197 default:
6198 return 0;
6199 }
6200
6201 return ipc_has_perm(shp, perms);
6202 }
6203
selinux_shm_shmat(struct kern_ipc_perm * shp,char __user * shmaddr,int shmflg)6204 static int selinux_shm_shmat(struct kern_ipc_perm *shp,
6205 char __user *shmaddr, int shmflg)
6206 {
6207 u32 perms;
6208
6209 if (shmflg & SHM_RDONLY)
6210 perms = SHM__READ;
6211 else
6212 perms = SHM__READ | SHM__WRITE;
6213
6214 return ipc_has_perm(shp, perms);
6215 }
6216
6217 /* Semaphore security operations */
selinux_sem_alloc_security(struct kern_ipc_perm * sma)6218 static int selinux_sem_alloc_security(struct kern_ipc_perm *sma)
6219 {
6220 struct ipc_security_struct *isec;
6221 struct common_audit_data ad;
6222 u32 sid = current_sid();
6223
6224 isec = selinux_ipc(sma);
6225 ipc_init_security(isec, SECCLASS_SEM);
6226
6227 ad.type = LSM_AUDIT_DATA_IPC;
6228 ad.u.ipc_id = sma->key;
6229
6230 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
6231 SEM__CREATE, &ad);
6232 }
6233
selinux_sem_associate(struct kern_ipc_perm * sma,int semflg)6234 static int selinux_sem_associate(struct kern_ipc_perm *sma, int semflg)
6235 {
6236 struct ipc_security_struct *isec;
6237 struct common_audit_data ad;
6238 u32 sid = current_sid();
6239
6240 isec = selinux_ipc(sma);
6241
6242 ad.type = LSM_AUDIT_DATA_IPC;
6243 ad.u.ipc_id = sma->key;
6244
6245 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
6246 SEM__ASSOCIATE, &ad);
6247 }
6248
6249 /* Note, at this point, sma is locked down */
selinux_sem_semctl(struct kern_ipc_perm * sma,int cmd)6250 static int selinux_sem_semctl(struct kern_ipc_perm *sma, int cmd)
6251 {
6252 int err;
6253 u32 perms;
6254
6255 switch (cmd) {
6256 case IPC_INFO:
6257 case SEM_INFO:
6258 /* No specific object, just general system-wide information. */
6259 return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6260 SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6261 case GETPID:
6262 case GETNCNT:
6263 case GETZCNT:
6264 perms = SEM__GETATTR;
6265 break;
6266 case GETVAL:
6267 case GETALL:
6268 perms = SEM__READ;
6269 break;
6270 case SETVAL:
6271 case SETALL:
6272 perms = SEM__WRITE;
6273 break;
6274 case IPC_RMID:
6275 perms = SEM__DESTROY;
6276 break;
6277 case IPC_SET:
6278 perms = SEM__SETATTR;
6279 break;
6280 case IPC_STAT:
6281 case SEM_STAT:
6282 case SEM_STAT_ANY:
6283 perms = SEM__GETATTR | SEM__ASSOCIATE;
6284 break;
6285 default:
6286 return 0;
6287 }
6288
6289 err = ipc_has_perm(sma, perms);
6290 return err;
6291 }
6292
selinux_sem_semop(struct kern_ipc_perm * sma,struct sembuf * sops,unsigned nsops,int alter)6293 static int selinux_sem_semop(struct kern_ipc_perm *sma,
6294 struct sembuf *sops, unsigned nsops, int alter)
6295 {
6296 u32 perms;
6297
6298 if (alter)
6299 perms = SEM__READ | SEM__WRITE;
6300 else
6301 perms = SEM__READ;
6302
6303 return ipc_has_perm(sma, perms);
6304 }
6305
selinux_ipc_permission(struct kern_ipc_perm * ipcp,short flag)6306 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
6307 {
6308 u32 av = 0;
6309
6310 av = 0;
6311 if (flag & S_IRUGO)
6312 av |= IPC__UNIX_READ;
6313 if (flag & S_IWUGO)
6314 av |= IPC__UNIX_WRITE;
6315
6316 if (av == 0)
6317 return 0;
6318
6319 return ipc_has_perm(ipcp, av);
6320 }
6321
selinux_ipc_getsecid(struct kern_ipc_perm * ipcp,u32 * secid)6322 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
6323 {
6324 struct ipc_security_struct *isec = selinux_ipc(ipcp);
6325 *secid = isec->sid;
6326 }
6327
selinux_d_instantiate(struct dentry * dentry,struct inode * inode)6328 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
6329 {
6330 if (inode)
6331 inode_doinit_with_dentry(inode, dentry);
6332 }
6333
selinux_lsm_getattr(unsigned int attr,struct task_struct * p,char ** value)6334 static int selinux_lsm_getattr(unsigned int attr, struct task_struct *p,
6335 char **value)
6336 {
6337 const struct task_security_struct *tsec;
6338 int error;
6339 u32 sid;
6340 u32 len;
6341
6342 rcu_read_lock();
6343 tsec = selinux_cred(__task_cred(p));
6344 if (p != current) {
6345 error = avc_has_perm(current_sid(), tsec->sid,
6346 SECCLASS_PROCESS, PROCESS__GETATTR, NULL);
6347 if (error)
6348 goto err_unlock;
6349 }
6350 switch (attr) {
6351 case LSM_ATTR_CURRENT:
6352 sid = tsec->sid;
6353 break;
6354 case LSM_ATTR_PREV:
6355 sid = tsec->osid;
6356 break;
6357 case LSM_ATTR_EXEC:
6358 sid = tsec->exec_sid;
6359 break;
6360 case LSM_ATTR_FSCREATE:
6361 sid = tsec->create_sid;
6362 break;
6363 case LSM_ATTR_KEYCREATE:
6364 sid = tsec->keycreate_sid;
6365 break;
6366 case LSM_ATTR_SOCKCREATE:
6367 sid = tsec->sockcreate_sid;
6368 break;
6369 default:
6370 error = -EOPNOTSUPP;
6371 goto err_unlock;
6372 }
6373 rcu_read_unlock();
6374
6375 if (sid == SECSID_NULL) {
6376 *value = NULL;
6377 return 0;
6378 }
6379
6380 error = security_sid_to_context(sid, value, &len);
6381 if (error)
6382 return error;
6383 return len;
6384
6385 err_unlock:
6386 rcu_read_unlock();
6387 return error;
6388 }
6389
selinux_lsm_setattr(u64 attr,void * value,size_t size)6390 static int selinux_lsm_setattr(u64 attr, void *value, size_t size)
6391 {
6392 struct task_security_struct *tsec;
6393 struct cred *new;
6394 u32 mysid = current_sid(), sid = 0, ptsid;
6395 int error;
6396 char *str = value;
6397
6398 /*
6399 * Basic control over ability to set these attributes at all.
6400 */
6401 switch (attr) {
6402 case LSM_ATTR_EXEC:
6403 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6404 PROCESS__SETEXEC, NULL);
6405 break;
6406 case LSM_ATTR_FSCREATE:
6407 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6408 PROCESS__SETFSCREATE, NULL);
6409 break;
6410 case LSM_ATTR_KEYCREATE:
6411 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6412 PROCESS__SETKEYCREATE, NULL);
6413 break;
6414 case LSM_ATTR_SOCKCREATE:
6415 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6416 PROCESS__SETSOCKCREATE, NULL);
6417 break;
6418 case LSM_ATTR_CURRENT:
6419 error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6420 PROCESS__SETCURRENT, NULL);
6421 break;
6422 default:
6423 error = -EOPNOTSUPP;
6424 break;
6425 }
6426 if (error)
6427 return error;
6428
6429 /* Obtain a SID for the context, if one was specified. */
6430 if (size && str[0] && str[0] != '\n') {
6431 if (str[size-1] == '\n') {
6432 str[size-1] = 0;
6433 size--;
6434 }
6435 error = security_context_to_sid(value, size,
6436 &sid, GFP_KERNEL);
6437 if (error == -EINVAL && attr == LSM_ATTR_FSCREATE) {
6438 if (!has_cap_mac_admin(true)) {
6439 struct audit_buffer *ab;
6440 size_t audit_size;
6441
6442 /* We strip a nul only if it is at the end,
6443 * otherwise the context contains a nul and
6444 * we should audit that */
6445 if (str[size - 1] == '\0')
6446 audit_size = size - 1;
6447 else
6448 audit_size = size;
6449 ab = audit_log_start(audit_context(),
6450 GFP_ATOMIC,
6451 AUDIT_SELINUX_ERR);
6452 if (!ab)
6453 return error;
6454 audit_log_format(ab, "op=fscreate invalid_context=");
6455 audit_log_n_untrustedstring(ab, value,
6456 audit_size);
6457 audit_log_end(ab);
6458
6459 return error;
6460 }
6461 error = security_context_to_sid_force(value, size,
6462 &sid);
6463 }
6464 if (error)
6465 return error;
6466 }
6467
6468 new = prepare_creds();
6469 if (!new)
6470 return -ENOMEM;
6471
6472 /* Permission checking based on the specified context is
6473 performed during the actual operation (execve,
6474 open/mkdir/...), when we know the full context of the
6475 operation. See selinux_bprm_creds_for_exec for the execve
6476 checks and may_create for the file creation checks. The
6477 operation will then fail if the context is not permitted. */
6478 tsec = selinux_cred(new);
6479 if (attr == LSM_ATTR_EXEC) {
6480 tsec->exec_sid = sid;
6481 } else if (attr == LSM_ATTR_FSCREATE) {
6482 tsec->create_sid = sid;
6483 } else if (attr == LSM_ATTR_KEYCREATE) {
6484 if (sid) {
6485 error = avc_has_perm(mysid, sid,
6486 SECCLASS_KEY, KEY__CREATE, NULL);
6487 if (error)
6488 goto abort_change;
6489 }
6490 tsec->keycreate_sid = sid;
6491 } else if (attr == LSM_ATTR_SOCKCREATE) {
6492 tsec->sockcreate_sid = sid;
6493 } else if (attr == LSM_ATTR_CURRENT) {
6494 error = -EINVAL;
6495 if (sid == 0)
6496 goto abort_change;
6497
6498 if (!current_is_single_threaded()) {
6499 error = security_bounded_transition(tsec->sid, sid);
6500 if (error)
6501 goto abort_change;
6502 }
6503
6504 /* Check permissions for the transition. */
6505 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
6506 PROCESS__DYNTRANSITION, NULL);
6507 if (error)
6508 goto abort_change;
6509
6510 /* Check for ptracing, and update the task SID if ok.
6511 Otherwise, leave SID unchanged and fail. */
6512 ptsid = ptrace_parent_sid();
6513 if (ptsid != 0) {
6514 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
6515 PROCESS__PTRACE, NULL);
6516 if (error)
6517 goto abort_change;
6518 }
6519
6520 tsec->sid = sid;
6521 } else {
6522 error = -EINVAL;
6523 goto abort_change;
6524 }
6525
6526 commit_creds(new);
6527 return size;
6528
6529 abort_change:
6530 abort_creds(new);
6531 return error;
6532 }
6533
6534 /**
6535 * selinux_getselfattr - Get SELinux current task attributes
6536 * @attr: the requested attribute
6537 * @ctx: buffer to receive the result
6538 * @size: buffer size (input), buffer size used (output)
6539 * @flags: unused
6540 *
6541 * Fill the passed user space @ctx with the details of the requested
6542 * attribute.
6543 *
6544 * Returns the number of attributes on success, an error code otherwise.
6545 * There will only ever be one attribute.
6546 */
selinux_getselfattr(unsigned int attr,struct lsm_ctx __user * ctx,u32 * size,u32 flags)6547 static int selinux_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
6548 u32 *size, u32 flags)
6549 {
6550 int rc;
6551 char *val = NULL;
6552 int val_len;
6553
6554 val_len = selinux_lsm_getattr(attr, current, &val);
6555 if (val_len < 0)
6556 return val_len;
6557 rc = lsm_fill_user_ctx(ctx, size, val, val_len, LSM_ID_SELINUX, 0);
6558 kfree(val);
6559 return (!rc ? 1 : rc);
6560 }
6561
selinux_setselfattr(unsigned int attr,struct lsm_ctx * ctx,u32 size,u32 flags)6562 static int selinux_setselfattr(unsigned int attr, struct lsm_ctx *ctx,
6563 u32 size, u32 flags)
6564 {
6565 int rc;
6566
6567 rc = selinux_lsm_setattr(attr, ctx->ctx, ctx->ctx_len);
6568 if (rc > 0)
6569 return 0;
6570 return rc;
6571 }
6572
selinux_getprocattr(struct task_struct * p,const char * name,char ** value)6573 static int selinux_getprocattr(struct task_struct *p,
6574 const char *name, char **value)
6575 {
6576 unsigned int attr = lsm_name_to_attr(name);
6577 int rc;
6578
6579 if (attr) {
6580 rc = selinux_lsm_getattr(attr, p, value);
6581 if (rc != -EOPNOTSUPP)
6582 return rc;
6583 }
6584
6585 return -EINVAL;
6586 }
6587
selinux_setprocattr(const char * name,void * value,size_t size)6588 static int selinux_setprocattr(const char *name, void *value, size_t size)
6589 {
6590 int attr = lsm_name_to_attr(name);
6591
6592 if (attr)
6593 return selinux_lsm_setattr(attr, value, size);
6594 return -EINVAL;
6595 }
6596
selinux_ismaclabel(const char * name)6597 static int selinux_ismaclabel(const char *name)
6598 {
6599 return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
6600 }
6601
selinux_secid_to_secctx(u32 secid,char ** secdata,u32 * seclen)6602 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
6603 {
6604 return security_sid_to_context(secid,
6605 secdata, seclen);
6606 }
6607
selinux_secctx_to_secid(const char * secdata,u32 seclen,u32 * secid)6608 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
6609 {
6610 return security_context_to_sid(secdata, seclen,
6611 secid, GFP_KERNEL);
6612 }
6613
selinux_release_secctx(char * secdata,u32 seclen)6614 static void selinux_release_secctx(char *secdata, u32 seclen)
6615 {
6616 kfree(secdata);
6617 }
6618
selinux_inode_invalidate_secctx(struct inode * inode)6619 static void selinux_inode_invalidate_secctx(struct inode *inode)
6620 {
6621 struct inode_security_struct *isec = selinux_inode(inode);
6622
6623 spin_lock(&isec->lock);
6624 isec->initialized = LABEL_INVALID;
6625 spin_unlock(&isec->lock);
6626 }
6627
6628 /*
6629 * called with inode->i_mutex locked
6630 */
selinux_inode_notifysecctx(struct inode * inode,void * ctx,u32 ctxlen)6631 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
6632 {
6633 int rc = selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX,
6634 ctx, ctxlen, 0);
6635 /* Do not return error when suppressing label (SBLABEL_MNT not set). */
6636 return rc == -EOPNOTSUPP ? 0 : rc;
6637 }
6638
6639 /*
6640 * called with inode->i_mutex locked
6641 */
selinux_inode_setsecctx(struct dentry * dentry,void * ctx,u32 ctxlen)6642 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
6643 {
6644 return __vfs_setxattr_locked(&nop_mnt_idmap, dentry, XATTR_NAME_SELINUX,
6645 ctx, ctxlen, 0, NULL);
6646 }
6647
selinux_inode_getsecctx(struct inode * inode,void ** ctx,u32 * ctxlen)6648 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
6649 {
6650 int len = 0;
6651 len = selinux_inode_getsecurity(&nop_mnt_idmap, inode,
6652 XATTR_SELINUX_SUFFIX, ctx, true);
6653 if (len < 0)
6654 return len;
6655 *ctxlen = len;
6656 return 0;
6657 }
6658 #ifdef CONFIG_KEYS
6659
selinux_key_alloc(struct key * k,const struct cred * cred,unsigned long flags)6660 static int selinux_key_alloc(struct key *k, const struct cred *cred,
6661 unsigned long flags)
6662 {
6663 const struct task_security_struct *tsec;
6664 struct key_security_struct *ksec = selinux_key(k);
6665
6666 tsec = selinux_cred(cred);
6667 if (tsec->keycreate_sid)
6668 ksec->sid = tsec->keycreate_sid;
6669 else
6670 ksec->sid = tsec->sid;
6671
6672 return 0;
6673 }
6674
selinux_key_permission(key_ref_t key_ref,const struct cred * cred,enum key_need_perm need_perm)6675 static int selinux_key_permission(key_ref_t key_ref,
6676 const struct cred *cred,
6677 enum key_need_perm need_perm)
6678 {
6679 struct key *key;
6680 struct key_security_struct *ksec;
6681 u32 perm, sid;
6682
6683 switch (need_perm) {
6684 case KEY_NEED_VIEW:
6685 perm = KEY__VIEW;
6686 break;
6687 case KEY_NEED_READ:
6688 perm = KEY__READ;
6689 break;
6690 case KEY_NEED_WRITE:
6691 perm = KEY__WRITE;
6692 break;
6693 case KEY_NEED_SEARCH:
6694 perm = KEY__SEARCH;
6695 break;
6696 case KEY_NEED_LINK:
6697 perm = KEY__LINK;
6698 break;
6699 case KEY_NEED_SETATTR:
6700 perm = KEY__SETATTR;
6701 break;
6702 case KEY_NEED_UNLINK:
6703 case KEY_SYSADMIN_OVERRIDE:
6704 case KEY_AUTHTOKEN_OVERRIDE:
6705 case KEY_DEFER_PERM_CHECK:
6706 return 0;
6707 default:
6708 WARN_ON(1);
6709 return -EPERM;
6710
6711 }
6712
6713 sid = cred_sid(cred);
6714 key = key_ref_to_ptr(key_ref);
6715 ksec = selinux_key(key);
6716
6717 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
6718 }
6719
selinux_key_getsecurity(struct key * key,char ** _buffer)6720 static int selinux_key_getsecurity(struct key *key, char **_buffer)
6721 {
6722 struct key_security_struct *ksec = selinux_key(key);
6723 char *context = NULL;
6724 unsigned len;
6725 int rc;
6726
6727 rc = security_sid_to_context(ksec->sid,
6728 &context, &len);
6729 if (!rc)
6730 rc = len;
6731 *_buffer = context;
6732 return rc;
6733 }
6734
6735 #ifdef CONFIG_KEY_NOTIFICATIONS
selinux_watch_key(struct key * key)6736 static int selinux_watch_key(struct key *key)
6737 {
6738 struct key_security_struct *ksec = selinux_key(key);
6739 u32 sid = current_sid();
6740
6741 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, KEY__VIEW, NULL);
6742 }
6743 #endif
6744 #endif
6745
6746 #ifdef CONFIG_SECURITY_INFINIBAND
selinux_ib_pkey_access(void * ib_sec,u64 subnet_prefix,u16 pkey_val)6747 static int selinux_ib_pkey_access(void *ib_sec, u64 subnet_prefix, u16 pkey_val)
6748 {
6749 struct common_audit_data ad;
6750 int err;
6751 u32 sid = 0;
6752 struct ib_security_struct *sec = ib_sec;
6753 struct lsm_ibpkey_audit ibpkey;
6754
6755 err = sel_ib_pkey_sid(subnet_prefix, pkey_val, &sid);
6756 if (err)
6757 return err;
6758
6759 ad.type = LSM_AUDIT_DATA_IBPKEY;
6760 ibpkey.subnet_prefix = subnet_prefix;
6761 ibpkey.pkey = pkey_val;
6762 ad.u.ibpkey = &ibpkey;
6763 return avc_has_perm(sec->sid, sid,
6764 SECCLASS_INFINIBAND_PKEY,
6765 INFINIBAND_PKEY__ACCESS, &ad);
6766 }
6767
selinux_ib_endport_manage_subnet(void * ib_sec,const char * dev_name,u8 port_num)6768 static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name,
6769 u8 port_num)
6770 {
6771 struct common_audit_data ad;
6772 int err;
6773 u32 sid = 0;
6774 struct ib_security_struct *sec = ib_sec;
6775 struct lsm_ibendport_audit ibendport;
6776
6777 err = security_ib_endport_sid(dev_name, port_num,
6778 &sid);
6779
6780 if (err)
6781 return err;
6782
6783 ad.type = LSM_AUDIT_DATA_IBENDPORT;
6784 ibendport.dev_name = dev_name;
6785 ibendport.port = port_num;
6786 ad.u.ibendport = &ibendport;
6787 return avc_has_perm(sec->sid, sid,
6788 SECCLASS_INFINIBAND_ENDPORT,
6789 INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad);
6790 }
6791
selinux_ib_alloc_security(void * ib_sec)6792 static int selinux_ib_alloc_security(void *ib_sec)
6793 {
6794 struct ib_security_struct *sec = selinux_ib(ib_sec);
6795
6796 sec->sid = current_sid();
6797 return 0;
6798 }
6799 #endif
6800
6801 #ifdef CONFIG_BPF_SYSCALL
selinux_bpf(int cmd,union bpf_attr * attr,unsigned int size)6802 static int selinux_bpf(int cmd, union bpf_attr *attr,
6803 unsigned int size)
6804 {
6805 u32 sid = current_sid();
6806 int ret;
6807
6808 switch (cmd) {
6809 case BPF_MAP_CREATE:
6810 ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__MAP_CREATE,
6811 NULL);
6812 break;
6813 case BPF_PROG_LOAD:
6814 ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__PROG_LOAD,
6815 NULL);
6816 break;
6817 default:
6818 ret = 0;
6819 break;
6820 }
6821
6822 return ret;
6823 }
6824
bpf_map_fmode_to_av(fmode_t fmode)6825 static u32 bpf_map_fmode_to_av(fmode_t fmode)
6826 {
6827 u32 av = 0;
6828
6829 if (fmode & FMODE_READ)
6830 av |= BPF__MAP_READ;
6831 if (fmode & FMODE_WRITE)
6832 av |= BPF__MAP_WRITE;
6833 return av;
6834 }
6835
6836 /* This function will check the file pass through unix socket or binder to see
6837 * if it is a bpf related object. And apply corresponding checks on the bpf
6838 * object based on the type. The bpf maps and programs, not like other files and
6839 * socket, are using a shared anonymous inode inside the kernel as their inode.
6840 * So checking that inode cannot identify if the process have privilege to
6841 * access the bpf object and that's why we have to add this additional check in
6842 * selinux_file_receive and selinux_binder_transfer_files.
6843 */
bpf_fd_pass(const struct file * file,u32 sid)6844 static int bpf_fd_pass(const struct file *file, u32 sid)
6845 {
6846 struct bpf_security_struct *bpfsec;
6847 struct bpf_prog *prog;
6848 struct bpf_map *map;
6849 int ret;
6850
6851 if (file->f_op == &bpf_map_fops) {
6852 map = file->private_data;
6853 bpfsec = map->security;
6854 ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6855 bpf_map_fmode_to_av(file->f_mode), NULL);
6856 if (ret)
6857 return ret;
6858 } else if (file->f_op == &bpf_prog_fops) {
6859 prog = file->private_data;
6860 bpfsec = prog->aux->security;
6861 ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6862 BPF__PROG_RUN, NULL);
6863 if (ret)
6864 return ret;
6865 }
6866 return 0;
6867 }
6868
selinux_bpf_map(struct bpf_map * map,fmode_t fmode)6869 static int selinux_bpf_map(struct bpf_map *map, fmode_t fmode)
6870 {
6871 u32 sid = current_sid();
6872 struct bpf_security_struct *bpfsec;
6873
6874 bpfsec = map->security;
6875 return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6876 bpf_map_fmode_to_av(fmode), NULL);
6877 }
6878
selinux_bpf_prog(struct bpf_prog * prog)6879 static int selinux_bpf_prog(struct bpf_prog *prog)
6880 {
6881 u32 sid = current_sid();
6882 struct bpf_security_struct *bpfsec;
6883
6884 bpfsec = prog->aux->security;
6885 return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6886 BPF__PROG_RUN, NULL);
6887 }
6888
selinux_bpf_map_create(struct bpf_map * map,union bpf_attr * attr,struct bpf_token * token)6889 static int selinux_bpf_map_create(struct bpf_map *map, union bpf_attr *attr,
6890 struct bpf_token *token)
6891 {
6892 struct bpf_security_struct *bpfsec;
6893
6894 bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6895 if (!bpfsec)
6896 return -ENOMEM;
6897
6898 bpfsec->sid = current_sid();
6899 map->security = bpfsec;
6900
6901 return 0;
6902 }
6903
selinux_bpf_map_free(struct bpf_map * map)6904 static void selinux_bpf_map_free(struct bpf_map *map)
6905 {
6906 struct bpf_security_struct *bpfsec = map->security;
6907
6908 map->security = NULL;
6909 kfree(bpfsec);
6910 }
6911
selinux_bpf_prog_load(struct bpf_prog * prog,union bpf_attr * attr,struct bpf_token * token)6912 static int selinux_bpf_prog_load(struct bpf_prog *prog, union bpf_attr *attr,
6913 struct bpf_token *token)
6914 {
6915 struct bpf_security_struct *bpfsec;
6916
6917 bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6918 if (!bpfsec)
6919 return -ENOMEM;
6920
6921 bpfsec->sid = current_sid();
6922 prog->aux->security = bpfsec;
6923
6924 return 0;
6925 }
6926
selinux_bpf_prog_free(struct bpf_prog * prog)6927 static void selinux_bpf_prog_free(struct bpf_prog *prog)
6928 {
6929 struct bpf_security_struct *bpfsec = prog->aux->security;
6930
6931 prog->aux->security = NULL;
6932 kfree(bpfsec);
6933 }
6934
selinux_bpf_token_create(struct bpf_token * token,union bpf_attr * attr,const struct path * path)6935 static int selinux_bpf_token_create(struct bpf_token *token, union bpf_attr *attr,
6936 const struct path *path)
6937 {
6938 struct bpf_security_struct *bpfsec;
6939
6940 bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6941 if (!bpfsec)
6942 return -ENOMEM;
6943
6944 bpfsec->sid = current_sid();
6945 token->security = bpfsec;
6946
6947 return 0;
6948 }
6949
selinux_bpf_token_free(struct bpf_token * token)6950 static void selinux_bpf_token_free(struct bpf_token *token)
6951 {
6952 struct bpf_security_struct *bpfsec = token->security;
6953
6954 token->security = NULL;
6955 kfree(bpfsec);
6956 }
6957 #endif
6958
6959 struct lsm_blob_sizes selinux_blob_sizes __ro_after_init = {
6960 .lbs_cred = sizeof(struct task_security_struct),
6961 .lbs_file = sizeof(struct file_security_struct),
6962 .lbs_inode = sizeof(struct inode_security_struct),
6963 .lbs_ipc = sizeof(struct ipc_security_struct),
6964 .lbs_key = sizeof(struct key_security_struct),
6965 .lbs_msg_msg = sizeof(struct msg_security_struct),
6966 #ifdef CONFIG_PERF_EVENTS
6967 .lbs_perf_event = sizeof(struct perf_event_security_struct),
6968 #endif
6969 .lbs_sock = sizeof(struct sk_security_struct),
6970 .lbs_superblock = sizeof(struct superblock_security_struct),
6971 .lbs_xattr_count = SELINUX_INODE_INIT_XATTRS,
6972 .lbs_tun_dev = sizeof(struct tun_security_struct),
6973 .lbs_ib = sizeof(struct ib_security_struct),
6974 };
6975
6976 #ifdef CONFIG_PERF_EVENTS
selinux_perf_event_open(struct perf_event_attr * attr,int type)6977 static int selinux_perf_event_open(struct perf_event_attr *attr, int type)
6978 {
6979 u32 requested, sid = current_sid();
6980
6981 if (type == PERF_SECURITY_OPEN)
6982 requested = PERF_EVENT__OPEN;
6983 else if (type == PERF_SECURITY_CPU)
6984 requested = PERF_EVENT__CPU;
6985 else if (type == PERF_SECURITY_KERNEL)
6986 requested = PERF_EVENT__KERNEL;
6987 else if (type == PERF_SECURITY_TRACEPOINT)
6988 requested = PERF_EVENT__TRACEPOINT;
6989 else
6990 return -EINVAL;
6991
6992 return avc_has_perm(sid, sid, SECCLASS_PERF_EVENT,
6993 requested, NULL);
6994 }
6995
selinux_perf_event_alloc(struct perf_event * event)6996 static int selinux_perf_event_alloc(struct perf_event *event)
6997 {
6998 struct perf_event_security_struct *perfsec;
6999
7000 perfsec = selinux_perf_event(event->security);
7001 perfsec->sid = current_sid();
7002
7003 return 0;
7004 }
7005
selinux_perf_event_read(struct perf_event * event)7006 static int selinux_perf_event_read(struct perf_event *event)
7007 {
7008 struct perf_event_security_struct *perfsec = event->security;
7009 u32 sid = current_sid();
7010
7011 return avc_has_perm(sid, perfsec->sid,
7012 SECCLASS_PERF_EVENT, PERF_EVENT__READ, NULL);
7013 }
7014
selinux_perf_event_write(struct perf_event * event)7015 static int selinux_perf_event_write(struct perf_event *event)
7016 {
7017 struct perf_event_security_struct *perfsec = event->security;
7018 u32 sid = current_sid();
7019
7020 return avc_has_perm(sid, perfsec->sid,
7021 SECCLASS_PERF_EVENT, PERF_EVENT__WRITE, NULL);
7022 }
7023 #endif
7024
7025 #ifdef CONFIG_IO_URING
7026 /**
7027 * selinux_uring_override_creds - check the requested cred override
7028 * @new: the target creds
7029 *
7030 * Check to see if the current task is allowed to override it's credentials
7031 * to service an io_uring operation.
7032 */
selinux_uring_override_creds(const struct cred * new)7033 static int selinux_uring_override_creds(const struct cred *new)
7034 {
7035 return avc_has_perm(current_sid(), cred_sid(new),
7036 SECCLASS_IO_URING, IO_URING__OVERRIDE_CREDS, NULL);
7037 }
7038
7039 /**
7040 * selinux_uring_sqpoll - check if a io_uring polling thread can be created
7041 *
7042 * Check to see if the current task is allowed to create a new io_uring
7043 * kernel polling thread.
7044 */
selinux_uring_sqpoll(void)7045 static int selinux_uring_sqpoll(void)
7046 {
7047 u32 sid = current_sid();
7048
7049 return avc_has_perm(sid, sid,
7050 SECCLASS_IO_URING, IO_URING__SQPOLL, NULL);
7051 }
7052
7053 /**
7054 * selinux_uring_cmd - check if IORING_OP_URING_CMD is allowed
7055 * @ioucmd: the io_uring command structure
7056 *
7057 * Check to see if the current domain is allowed to execute an
7058 * IORING_OP_URING_CMD against the device/file specified in @ioucmd.
7059 *
7060 */
selinux_uring_cmd(struct io_uring_cmd * ioucmd)7061 static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)
7062 {
7063 struct file *file = ioucmd->file;
7064 struct inode *inode = file_inode(file);
7065 struct inode_security_struct *isec = selinux_inode(inode);
7066 struct common_audit_data ad;
7067
7068 ad.type = LSM_AUDIT_DATA_FILE;
7069 ad.u.file = file;
7070
7071 return avc_has_perm(current_sid(), isec->sid,
7072 SECCLASS_IO_URING, IO_URING__CMD, &ad);
7073 }
7074 #endif /* CONFIG_IO_URING */
7075
7076 static const struct lsm_id selinux_lsmid = {
7077 .name = "selinux",
7078 .id = LSM_ID_SELINUX,
7079 };
7080
7081 /*
7082 * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order:
7083 * 1. any hooks that don't belong to (2.) or (3.) below,
7084 * 2. hooks that both access structures allocated by other hooks, and allocate
7085 * structures that can be later accessed by other hooks (mostly "cloning"
7086 * hooks),
7087 * 3. hooks that only allocate structures that can be later accessed by other
7088 * hooks ("allocating" hooks).
7089 *
7090 * Please follow block comment delimiters in the list to keep this order.
7091 */
7092 static struct security_hook_list selinux_hooks[] __ro_after_init = {
7093 LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
7094 LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
7095 LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder),
7096 LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file),
7097
7098 LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check),
7099 LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme),
7100 LSM_HOOK_INIT(capget, selinux_capget),
7101 LSM_HOOK_INIT(capset, selinux_capset),
7102 LSM_HOOK_INIT(capable, selinux_capable),
7103 LSM_HOOK_INIT(quotactl, selinux_quotactl),
7104 LSM_HOOK_INIT(quota_on, selinux_quota_on),
7105 LSM_HOOK_INIT(syslog, selinux_syslog),
7106 LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory),
7107
7108 LSM_HOOK_INIT(netlink_send, selinux_netlink_send),
7109
7110 LSM_HOOK_INIT(bprm_creds_for_exec, selinux_bprm_creds_for_exec),
7111 LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds),
7112 LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds),
7113
7114 LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
7115 LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat),
7116 LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
7117 LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
7118 LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
7119 LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs),
7120 LSM_HOOK_INIT(sb_mount, selinux_mount),
7121 LSM_HOOK_INIT(sb_umount, selinux_umount),
7122 LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
7123 LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
7124
7125 LSM_HOOK_INIT(move_mount, selinux_move_mount),
7126
7127 LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
7128 LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
7129
7130 LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security),
7131 LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security),
7132 LSM_HOOK_INIT(inode_init_security_anon, selinux_inode_init_security_anon),
7133 LSM_HOOK_INIT(inode_create, selinux_inode_create),
7134 LSM_HOOK_INIT(inode_link, selinux_inode_link),
7135 LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink),
7136 LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink),
7137 LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir),
7138 LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir),
7139 LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod),
7140 LSM_HOOK_INIT(inode_rename, selinux_inode_rename),
7141 LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink),
7142 LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link),
7143 LSM_HOOK_INIT(inode_permission, selinux_inode_permission),
7144 LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr),
7145 LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr),
7146 LSM_HOOK_INIT(inode_xattr_skipcap, selinux_inode_xattr_skipcap),
7147 LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr),
7148 LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr),
7149 LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr),
7150 LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr),
7151 LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr),
7152 LSM_HOOK_INIT(inode_set_acl, selinux_inode_set_acl),
7153 LSM_HOOK_INIT(inode_get_acl, selinux_inode_get_acl),
7154 LSM_HOOK_INIT(inode_remove_acl, selinux_inode_remove_acl),
7155 LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity),
7156 LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
7157 LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
7158 LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
7159 LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
7160 LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
7161 LSM_HOOK_INIT(path_notify, selinux_path_notify),
7162
7163 LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security),
7164
7165 LSM_HOOK_INIT(file_permission, selinux_file_permission),
7166 LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
7167 LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl),
7168 LSM_HOOK_INIT(file_ioctl_compat, selinux_file_ioctl_compat),
7169 LSM_HOOK_INIT(mmap_file, selinux_mmap_file),
7170 LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr),
7171 LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect),
7172 LSM_HOOK_INIT(file_lock, selinux_file_lock),
7173 LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl),
7174 LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner),
7175 LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask),
7176 LSM_HOOK_INIT(file_receive, selinux_file_receive),
7177
7178 LSM_HOOK_INIT(file_open, selinux_file_open),
7179
7180 LSM_HOOK_INIT(task_alloc, selinux_task_alloc),
7181 LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare),
7182 LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer),
7183 LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid),
7184 LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as),
7185 LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as),
7186 LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request),
7187 LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data),
7188 LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file),
7189 LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid),
7190 LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid),
7191 LSM_HOOK_INIT(task_getsid, selinux_task_getsid),
7192 LSM_HOOK_INIT(current_getsecid_subj, selinux_current_getsecid_subj),
7193 LSM_HOOK_INIT(task_getsecid_obj, selinux_task_getsecid_obj),
7194 LSM_HOOK_INIT(task_setnice, selinux_task_setnice),
7195 LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio),
7196 LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio),
7197 LSM_HOOK_INIT(task_prlimit, selinux_task_prlimit),
7198 LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit),
7199 LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler),
7200 LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler),
7201 LSM_HOOK_INIT(task_movememory, selinux_task_movememory),
7202 LSM_HOOK_INIT(task_kill, selinux_task_kill),
7203 LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode),
7204 LSM_HOOK_INIT(userns_create, selinux_userns_create),
7205
7206 LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
7207 LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),
7208
7209 LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
7210 LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
7211 LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd),
7212 LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv),
7213
7214 LSM_HOOK_INIT(shm_associate, selinux_shm_associate),
7215 LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl),
7216 LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat),
7217
7218 LSM_HOOK_INIT(sem_associate, selinux_sem_associate),
7219 LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl),
7220 LSM_HOOK_INIT(sem_semop, selinux_sem_semop),
7221
7222 LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate),
7223
7224 LSM_HOOK_INIT(getselfattr, selinux_getselfattr),
7225 LSM_HOOK_INIT(setselfattr, selinux_setselfattr),
7226 LSM_HOOK_INIT(getprocattr, selinux_getprocattr),
7227 LSM_HOOK_INIT(setprocattr, selinux_setprocattr),
7228
7229 LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel),
7230 LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
7231 LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
7232 LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
7233 LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
7234 LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
7235
7236 LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect),
7237 LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send),
7238
7239 LSM_HOOK_INIT(socket_create, selinux_socket_create),
7240 LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create),
7241 LSM_HOOK_INIT(socket_socketpair, selinux_socket_socketpair),
7242 LSM_HOOK_INIT(socket_bind, selinux_socket_bind),
7243 LSM_HOOK_INIT(socket_connect, selinux_socket_connect),
7244 LSM_HOOK_INIT(socket_listen, selinux_socket_listen),
7245 LSM_HOOK_INIT(socket_accept, selinux_socket_accept),
7246 LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg),
7247 LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg),
7248 LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname),
7249 LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername),
7250 LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt),
7251 LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt),
7252 LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown),
7253 LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb),
7254 LSM_HOOK_INIT(socket_getpeersec_stream,
7255 selinux_socket_getpeersec_stream),
7256 LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram),
7257 LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security),
7258 LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
7259 LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
7260 LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
7261 LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request),
7262 LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone),
7263 LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect),
7264 LSM_HOOK_INIT(sctp_assoc_established, selinux_sctp_assoc_established),
7265 LSM_HOOK_INIT(mptcp_add_subflow, selinux_mptcp_add_subflow),
7266 LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
7267 LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
7268 LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
7269 LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet),
7270 LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc),
7271 LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec),
7272 LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow),
7273 LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create),
7274 LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue),
7275 LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach),
7276 LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
7277 #ifdef CONFIG_SECURITY_INFINIBAND
7278 LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
7279 LSM_HOOK_INIT(ib_endport_manage_subnet,
7280 selinux_ib_endport_manage_subnet),
7281 #endif
7282 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7283 LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free),
7284 LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete),
7285 LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free),
7286 LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete),
7287 LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup),
7288 LSM_HOOK_INIT(xfrm_state_pol_flow_match,
7289 selinux_xfrm_state_pol_flow_match),
7290 LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session),
7291 #endif
7292
7293 #ifdef CONFIG_KEYS
7294 LSM_HOOK_INIT(key_permission, selinux_key_permission),
7295 LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
7296 #ifdef CONFIG_KEY_NOTIFICATIONS
7297 LSM_HOOK_INIT(watch_key, selinux_watch_key),
7298 #endif
7299 #endif
7300
7301 #ifdef CONFIG_AUDIT
7302 LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known),
7303 LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match),
7304 LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free),
7305 #endif
7306
7307 #ifdef CONFIG_BPF_SYSCALL
7308 LSM_HOOK_INIT(bpf, selinux_bpf),
7309 LSM_HOOK_INIT(bpf_map, selinux_bpf_map),
7310 LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog),
7311 LSM_HOOK_INIT(bpf_map_free, selinux_bpf_map_free),
7312 LSM_HOOK_INIT(bpf_prog_free, selinux_bpf_prog_free),
7313 LSM_HOOK_INIT(bpf_token_free, selinux_bpf_token_free),
7314 #endif
7315
7316 #ifdef CONFIG_PERF_EVENTS
7317 LSM_HOOK_INIT(perf_event_open, selinux_perf_event_open),
7318 LSM_HOOK_INIT(perf_event_read, selinux_perf_event_read),
7319 LSM_HOOK_INIT(perf_event_write, selinux_perf_event_write),
7320 #endif
7321
7322 #ifdef CONFIG_IO_URING
7323 LSM_HOOK_INIT(uring_override_creds, selinux_uring_override_creds),
7324 LSM_HOOK_INIT(uring_sqpoll, selinux_uring_sqpoll),
7325 LSM_HOOK_INIT(uring_cmd, selinux_uring_cmd),
7326 #endif
7327
7328 /*
7329 * PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE
7330 */
7331 LSM_HOOK_INIT(fs_context_submount, selinux_fs_context_submount),
7332 LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup),
7333 LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
7334 LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
7335 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7336 LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone),
7337 #endif
7338
7339 /*
7340 * PUT "ALLOCATING" HOOKS HERE
7341 */
7342 LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security),
7343 LSM_HOOK_INIT(msg_queue_alloc_security,
7344 selinux_msg_queue_alloc_security),
7345 LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security),
7346 LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
7347 LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security),
7348 LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security),
7349 LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
7350 LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),
7351 LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security),
7352 LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security),
7353 #ifdef CONFIG_SECURITY_INFINIBAND
7354 LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security),
7355 #endif
7356 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7357 LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc),
7358 LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc),
7359 LSM_HOOK_INIT(xfrm_state_alloc_acquire,
7360 selinux_xfrm_state_alloc_acquire),
7361 #endif
7362 #ifdef CONFIG_KEYS
7363 LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
7364 #endif
7365 #ifdef CONFIG_AUDIT
7366 LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init),
7367 #endif
7368 #ifdef CONFIG_BPF_SYSCALL
7369 LSM_HOOK_INIT(bpf_map_create, selinux_bpf_map_create),
7370 LSM_HOOK_INIT(bpf_prog_load, selinux_bpf_prog_load),
7371 LSM_HOOK_INIT(bpf_token_create, selinux_bpf_token_create),
7372 #endif
7373 #ifdef CONFIG_PERF_EVENTS
7374 LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc),
7375 #endif
7376 };
7377
selinux_init(void)7378 static __init int selinux_init(void)
7379 {
7380 pr_info("SELinux: Initializing.\n");
7381
7382 memset(&selinux_state, 0, sizeof(selinux_state));
7383 enforcing_set(selinux_enforcing_boot);
7384 selinux_avc_init();
7385 mutex_init(&selinux_state.status_lock);
7386 mutex_init(&selinux_state.policy_mutex);
7387
7388 /* Set the security state for the initial task. */
7389 cred_init_security();
7390
7391 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
7392 if (!default_noexec)
7393 pr_notice("SELinux: virtual memory is executable by default\n");
7394
7395 avc_init();
7396
7397 avtab_cache_init();
7398
7399 ebitmap_cache_init();
7400
7401 hashtab_cache_init();
7402
7403 security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks),
7404 &selinux_lsmid);
7405
7406 if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
7407 panic("SELinux: Unable to register AVC netcache callback\n");
7408
7409 if (avc_add_callback(selinux_lsm_notifier_avc_callback, AVC_CALLBACK_RESET))
7410 panic("SELinux: Unable to register AVC LSM notifier callback\n");
7411
7412 if (selinux_enforcing_boot)
7413 pr_debug("SELinux: Starting in enforcing mode\n");
7414 else
7415 pr_debug("SELinux: Starting in permissive mode\n");
7416
7417 fs_validate_description("selinux", selinux_fs_parameters);
7418
7419 return 0;
7420 }
7421
delayed_superblock_init(struct super_block * sb,void * unused)7422 static void delayed_superblock_init(struct super_block *sb, void *unused)
7423 {
7424 selinux_set_mnt_opts(sb, NULL, 0, NULL);
7425 }
7426
selinux_complete_init(void)7427 void selinux_complete_init(void)
7428 {
7429 pr_debug("SELinux: Completing initialization.\n");
7430
7431 /* Set up any superblocks initialized prior to the policy load. */
7432 pr_debug("SELinux: Setting up existing superblocks.\n");
7433 iterate_supers(delayed_superblock_init, NULL);
7434 }
7435
7436 /* SELinux requires early initialization in order to label
7437 all processes and objects when they are created. */
7438 DEFINE_LSM(selinux) = {
7439 .name = "selinux",
7440 .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
7441 .enabled = &selinux_enabled_boot,
7442 .blobs = &selinux_blob_sizes,
7443 .init = selinux_init,
7444 };
7445
7446 #if defined(CONFIG_NETFILTER)
7447 static const struct nf_hook_ops selinux_nf_ops[] = {
7448 {
7449 .hook = selinux_ip_postroute,
7450 .pf = NFPROTO_IPV4,
7451 .hooknum = NF_INET_POST_ROUTING,
7452 .priority = NF_IP_PRI_SELINUX_LAST,
7453 },
7454 {
7455 .hook = selinux_ip_forward,
7456 .pf = NFPROTO_IPV4,
7457 .hooknum = NF_INET_FORWARD,
7458 .priority = NF_IP_PRI_SELINUX_FIRST,
7459 },
7460 {
7461 .hook = selinux_ip_output,
7462 .pf = NFPROTO_IPV4,
7463 .hooknum = NF_INET_LOCAL_OUT,
7464 .priority = NF_IP_PRI_SELINUX_FIRST,
7465 },
7466 #if IS_ENABLED(CONFIG_IPV6)
7467 {
7468 .hook = selinux_ip_postroute,
7469 .pf = NFPROTO_IPV6,
7470 .hooknum = NF_INET_POST_ROUTING,
7471 .priority = NF_IP6_PRI_SELINUX_LAST,
7472 },
7473 {
7474 .hook = selinux_ip_forward,
7475 .pf = NFPROTO_IPV6,
7476 .hooknum = NF_INET_FORWARD,
7477 .priority = NF_IP6_PRI_SELINUX_FIRST,
7478 },
7479 {
7480 .hook = selinux_ip_output,
7481 .pf = NFPROTO_IPV6,
7482 .hooknum = NF_INET_LOCAL_OUT,
7483 .priority = NF_IP6_PRI_SELINUX_FIRST,
7484 },
7485 #endif /* IPV6 */
7486 };
7487
selinux_nf_register(struct net * net)7488 static int __net_init selinux_nf_register(struct net *net)
7489 {
7490 return nf_register_net_hooks(net, selinux_nf_ops,
7491 ARRAY_SIZE(selinux_nf_ops));
7492 }
7493
selinux_nf_unregister(struct net * net)7494 static void __net_exit selinux_nf_unregister(struct net *net)
7495 {
7496 nf_unregister_net_hooks(net, selinux_nf_ops,
7497 ARRAY_SIZE(selinux_nf_ops));
7498 }
7499
7500 static struct pernet_operations selinux_net_ops = {
7501 .init = selinux_nf_register,
7502 .exit = selinux_nf_unregister,
7503 };
7504
selinux_nf_ip_init(void)7505 static int __init selinux_nf_ip_init(void)
7506 {
7507 int err;
7508
7509 if (!selinux_enabled_boot)
7510 return 0;
7511
7512 pr_debug("SELinux: Registering netfilter hooks\n");
7513
7514 err = register_pernet_subsys(&selinux_net_ops);
7515 if (err)
7516 panic("SELinux: register_pernet_subsys: error %d\n", err);
7517
7518 return 0;
7519 }
7520 __initcall(selinux_nf_ip_init);
7521 #endif /* CONFIG_NETFILTER */
7522