xref: /linux/security/selinux/hooks.c (revision 59024954a1e7e26b62680e1f2b5725249a6c09f7)
1 /*
2  *  NSA Security-Enhanced Linux (SELinux) security module
3  *
4  *  This file contains the SELinux hook function implementations.
5  *
6  *  Authors:  Stephen Smalley, <sds@epoch.ncsc.mil>
7  *	      Chris Vance, <cvance@nai.com>
8  *	      Wayne Salamon, <wsalamon@nai.com>
9  *	      James Morris <jmorris@redhat.com>
10  *
11  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12  *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
13  *					   Eric Paris <eparis@redhat.com>
14  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
15  *			    <dgoeddel@trustedcs.com>
16  *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
17  *	Paul Moore <paul@paul-moore.com>
18  *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
19  *		       Yuichi Nakamura <ynakam@hitachisoft.jp>
20  *
21  *	This program is free software; you can redistribute it and/or modify
22  *	it under the terms of the GNU General Public License version 2,
23  *	as published by the Free Software Foundation.
24  */
25 
26 #include <linux/init.h>
27 #include <linux/kd.h>
28 #include <linux/kernel.h>
29 #include <linux/tracehook.h>
30 #include <linux/errno.h>
31 #include <linux/sched.h>
32 #include <linux/lsm_hooks.h>
33 #include <linux/xattr.h>
34 #include <linux/capability.h>
35 #include <linux/unistd.h>
36 #include <linux/mm.h>
37 #include <linux/mman.h>
38 #include <linux/slab.h>
39 #include <linux/pagemap.h>
40 #include <linux/proc_fs.h>
41 #include <linux/swap.h>
42 #include <linux/spinlock.h>
43 #include <linux/syscalls.h>
44 #include <linux/dcache.h>
45 #include <linux/file.h>
46 #include <linux/fdtable.h>
47 #include <linux/namei.h>
48 #include <linux/mount.h>
49 #include <linux/netfilter_ipv4.h>
50 #include <linux/netfilter_ipv6.h>
51 #include <linux/tty.h>
52 #include <net/icmp.h>
53 #include <net/ip.h>		/* for local_port_range[] */
54 #include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
55 #include <net/inet_connection_sock.h>
56 #include <net/net_namespace.h>
57 #include <net/netlabel.h>
58 #include <linux/uaccess.h>
59 #include <asm/ioctls.h>
60 #include <linux/atomic.h>
61 #include <linux/bitops.h>
62 #include <linux/interrupt.h>
63 #include <linux/netdevice.h>	/* for network interface checks */
64 #include <net/netlink.h>
65 #include <linux/tcp.h>
66 #include <linux/udp.h>
67 #include <linux/dccp.h>
68 #include <linux/quota.h>
69 #include <linux/un.h>		/* for Unix socket types */
70 #include <net/af_unix.h>	/* for Unix socket types */
71 #include <linux/parser.h>
72 #include <linux/nfs_mount.h>
73 #include <net/ipv6.h>
74 #include <linux/hugetlb.h>
75 #include <linux/personality.h>
76 #include <linux/audit.h>
77 #include <linux/string.h>
78 #include <linux/selinux.h>
79 #include <linux/mutex.h>
80 #include <linux/posix-timers.h>
81 #include <linux/syslog.h>
82 #include <linux/user_namespace.h>
83 #include <linux/export.h>
84 #include <linux/msg.h>
85 #include <linux/shm.h>
86 
87 #include "avc.h"
88 #include "objsec.h"
89 #include "netif.h"
90 #include "netnode.h"
91 #include "netport.h"
92 #include "xfrm.h"
93 #include "netlabel.h"
94 #include "audit.h"
95 #include "avc_ss.h"
96 
97 /* SECMARK reference count */
98 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
99 
100 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
101 int selinux_enforcing;
102 
103 static int __init enforcing_setup(char *str)
104 {
105 	unsigned long enforcing;
106 	if (!kstrtoul(str, 0, &enforcing))
107 		selinux_enforcing = enforcing ? 1 : 0;
108 	return 1;
109 }
110 __setup("enforcing=", enforcing_setup);
111 #endif
112 
113 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
114 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
115 
116 static int __init selinux_enabled_setup(char *str)
117 {
118 	unsigned long enabled;
119 	if (!kstrtoul(str, 0, &enabled))
120 		selinux_enabled = enabled ? 1 : 0;
121 	return 1;
122 }
123 __setup("selinux=", selinux_enabled_setup);
124 #else
125 int selinux_enabled = 1;
126 #endif
127 
128 static struct kmem_cache *sel_inode_cache;
129 static struct kmem_cache *file_security_cache;
130 
131 /**
132  * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
133  *
134  * Description:
135  * This function checks the SECMARK reference counter to see if any SECMARK
136  * targets are currently configured, if the reference counter is greater than
137  * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
138  * enabled, false (0) if SECMARK is disabled.  If the always_check_network
139  * policy capability is enabled, SECMARK is always considered enabled.
140  *
141  */
142 static int selinux_secmark_enabled(void)
143 {
144 	return (selinux_policycap_alwaysnetwork || atomic_read(&selinux_secmark_refcount));
145 }
146 
147 /**
148  * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled
149  *
150  * Description:
151  * This function checks if NetLabel or labeled IPSEC is enabled.  Returns true
152  * (1) if any are enabled or false (0) if neither are enabled.  If the
153  * always_check_network policy capability is enabled, peer labeling
154  * is always considered enabled.
155  *
156  */
157 static int selinux_peerlbl_enabled(void)
158 {
159 	return (selinux_policycap_alwaysnetwork || netlbl_enabled() || selinux_xfrm_enabled());
160 }
161 
162 static int selinux_netcache_avc_callback(u32 event)
163 {
164 	if (event == AVC_CALLBACK_RESET) {
165 		sel_netif_flush();
166 		sel_netnode_flush();
167 		sel_netport_flush();
168 		synchronize_net();
169 	}
170 	return 0;
171 }
172 
173 /*
174  * initialise the security for the init task
175  */
176 static void cred_init_security(void)
177 {
178 	struct cred *cred = (struct cred *) current->real_cred;
179 	struct task_security_struct *tsec;
180 
181 	tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
182 	if (!tsec)
183 		panic("SELinux:  Failed to initialize initial task.\n");
184 
185 	tsec->osid = tsec->sid = SECINITSID_KERNEL;
186 	cred->security = tsec;
187 }
188 
189 /*
190  * get the security ID of a set of credentials
191  */
192 static inline u32 cred_sid(const struct cred *cred)
193 {
194 	const struct task_security_struct *tsec;
195 
196 	tsec = cred->security;
197 	return tsec->sid;
198 }
199 
200 /*
201  * get the objective security ID of a task
202  */
203 static inline u32 task_sid(const struct task_struct *task)
204 {
205 	u32 sid;
206 
207 	rcu_read_lock();
208 	sid = cred_sid(__task_cred(task));
209 	rcu_read_unlock();
210 	return sid;
211 }
212 
213 /*
214  * get the subjective security ID of the current task
215  */
216 static inline u32 current_sid(void)
217 {
218 	const struct task_security_struct *tsec = current_security();
219 
220 	return tsec->sid;
221 }
222 
223 /* Allocate and free functions for each kind of security blob. */
224 
225 static int inode_alloc_security(struct inode *inode)
226 {
227 	struct inode_security_struct *isec;
228 	u32 sid = current_sid();
229 
230 	isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
231 	if (!isec)
232 		return -ENOMEM;
233 
234 	mutex_init(&isec->lock);
235 	INIT_LIST_HEAD(&isec->list);
236 	isec->inode = inode;
237 	isec->sid = SECINITSID_UNLABELED;
238 	isec->sclass = SECCLASS_FILE;
239 	isec->task_sid = sid;
240 	inode->i_security = isec;
241 
242 	return 0;
243 }
244 
245 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
246 
247 /*
248  * Try reloading inode security labels that have been marked as invalid.  The
249  * @may_sleep parameter indicates when sleeping and thus reloading labels is
250  * allowed; when set to false, returns ERR_PTR(-ECHILD) when the label is
251  * invalid.  The @opt_dentry parameter should be set to a dentry of the inode;
252  * when no dentry is available, set it to NULL instead.
253  */
254 static int __inode_security_revalidate(struct inode *inode,
255 				       struct dentry *opt_dentry,
256 				       bool may_sleep)
257 {
258 	struct inode_security_struct *isec = inode->i_security;
259 
260 	might_sleep_if(may_sleep);
261 
262 	if (ss_initialized && isec->initialized != LABEL_INITIALIZED) {
263 		if (!may_sleep)
264 			return -ECHILD;
265 
266 		/*
267 		 * Try reloading the inode security label.  This will fail if
268 		 * @opt_dentry is NULL and no dentry for this inode can be
269 		 * found; in that case, continue using the old label.
270 		 */
271 		inode_doinit_with_dentry(inode, opt_dentry);
272 	}
273 	return 0;
274 }
275 
276 static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
277 {
278 	return inode->i_security;
279 }
280 
281 static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
282 {
283 	int error;
284 
285 	error = __inode_security_revalidate(inode, NULL, !rcu);
286 	if (error)
287 		return ERR_PTR(error);
288 	return inode->i_security;
289 }
290 
291 /*
292  * Get the security label of an inode.
293  */
294 static struct inode_security_struct *inode_security(struct inode *inode)
295 {
296 	__inode_security_revalidate(inode, NULL, true);
297 	return inode->i_security;
298 }
299 
300 static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
301 {
302 	struct inode *inode = d_backing_inode(dentry);
303 
304 	return inode->i_security;
305 }
306 
307 /*
308  * Get the security label of a dentry's backing inode.
309  */
310 static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
311 {
312 	struct inode *inode = d_backing_inode(dentry);
313 
314 	__inode_security_revalidate(inode, dentry, true);
315 	return inode->i_security;
316 }
317 
318 static void inode_free_rcu(struct rcu_head *head)
319 {
320 	struct inode_security_struct *isec;
321 
322 	isec = container_of(head, struct inode_security_struct, rcu);
323 	kmem_cache_free(sel_inode_cache, isec);
324 }
325 
326 static void inode_free_security(struct inode *inode)
327 {
328 	struct inode_security_struct *isec = inode->i_security;
329 	struct superblock_security_struct *sbsec = inode->i_sb->s_security;
330 
331 	/*
332 	 * As not all inode security structures are in a list, we check for
333 	 * empty list outside of the lock to make sure that we won't waste
334 	 * time taking a lock doing nothing.
335 	 *
336 	 * The list_del_init() function can be safely called more than once.
337 	 * It should not be possible for this function to be called with
338 	 * concurrent list_add(), but for better safety against future changes
339 	 * in the code, we use list_empty_careful() here.
340 	 */
341 	if (!list_empty_careful(&isec->list)) {
342 		spin_lock(&sbsec->isec_lock);
343 		list_del_init(&isec->list);
344 		spin_unlock(&sbsec->isec_lock);
345 	}
346 
347 	/*
348 	 * The inode may still be referenced in a path walk and
349 	 * a call to selinux_inode_permission() can be made
350 	 * after inode_free_security() is called. Ideally, the VFS
351 	 * wouldn't do this, but fixing that is a much harder
352 	 * job. For now, simply free the i_security via RCU, and
353 	 * leave the current inode->i_security pointer intact.
354 	 * The inode will be freed after the RCU grace period too.
355 	 */
356 	call_rcu(&isec->rcu, inode_free_rcu);
357 }
358 
359 static int file_alloc_security(struct file *file)
360 {
361 	struct file_security_struct *fsec;
362 	u32 sid = current_sid();
363 
364 	fsec = kmem_cache_zalloc(file_security_cache, GFP_KERNEL);
365 	if (!fsec)
366 		return -ENOMEM;
367 
368 	fsec->sid = sid;
369 	fsec->fown_sid = sid;
370 	file->f_security = fsec;
371 
372 	return 0;
373 }
374 
375 static void file_free_security(struct file *file)
376 {
377 	struct file_security_struct *fsec = file->f_security;
378 	file->f_security = NULL;
379 	kmem_cache_free(file_security_cache, fsec);
380 }
381 
382 static int superblock_alloc_security(struct super_block *sb)
383 {
384 	struct superblock_security_struct *sbsec;
385 
386 	sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
387 	if (!sbsec)
388 		return -ENOMEM;
389 
390 	mutex_init(&sbsec->lock);
391 	INIT_LIST_HEAD(&sbsec->isec_head);
392 	spin_lock_init(&sbsec->isec_lock);
393 	sbsec->sb = sb;
394 	sbsec->sid = SECINITSID_UNLABELED;
395 	sbsec->def_sid = SECINITSID_FILE;
396 	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
397 	sb->s_security = sbsec;
398 
399 	return 0;
400 }
401 
402 static void superblock_free_security(struct super_block *sb)
403 {
404 	struct superblock_security_struct *sbsec = sb->s_security;
405 	sb->s_security = NULL;
406 	kfree(sbsec);
407 }
408 
409 /* The file system's label must be initialized prior to use. */
410 
411 static const char *labeling_behaviors[7] = {
412 	"uses xattr",
413 	"uses transition SIDs",
414 	"uses task SIDs",
415 	"uses genfs_contexts",
416 	"not configured for labeling",
417 	"uses mountpoint labeling",
418 	"uses native labeling",
419 };
420 
421 static inline int inode_doinit(struct inode *inode)
422 {
423 	return inode_doinit_with_dentry(inode, NULL);
424 }
425 
426 enum {
427 	Opt_error = -1,
428 	Opt_context = 1,
429 	Opt_fscontext = 2,
430 	Opt_defcontext = 3,
431 	Opt_rootcontext = 4,
432 	Opt_labelsupport = 5,
433 	Opt_nextmntopt = 6,
434 };
435 
436 #define NUM_SEL_MNT_OPTS	(Opt_nextmntopt - 1)
437 
438 static const match_table_t tokens = {
439 	{Opt_context, CONTEXT_STR "%s"},
440 	{Opt_fscontext, FSCONTEXT_STR "%s"},
441 	{Opt_defcontext, DEFCONTEXT_STR "%s"},
442 	{Opt_rootcontext, ROOTCONTEXT_STR "%s"},
443 	{Opt_labelsupport, LABELSUPP_STR},
444 	{Opt_error, NULL},
445 };
446 
447 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
448 
449 static int may_context_mount_sb_relabel(u32 sid,
450 			struct superblock_security_struct *sbsec,
451 			const struct cred *cred)
452 {
453 	const struct task_security_struct *tsec = cred->security;
454 	int rc;
455 
456 	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
457 			  FILESYSTEM__RELABELFROM, NULL);
458 	if (rc)
459 		return rc;
460 
461 	rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
462 			  FILESYSTEM__RELABELTO, NULL);
463 	return rc;
464 }
465 
466 static int may_context_mount_inode_relabel(u32 sid,
467 			struct superblock_security_struct *sbsec,
468 			const struct cred *cred)
469 {
470 	const struct task_security_struct *tsec = cred->security;
471 	int rc;
472 	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
473 			  FILESYSTEM__RELABELFROM, NULL);
474 	if (rc)
475 		return rc;
476 
477 	rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
478 			  FILESYSTEM__ASSOCIATE, NULL);
479 	return rc;
480 }
481 
482 static int selinux_is_sblabel_mnt(struct super_block *sb)
483 {
484 	struct superblock_security_struct *sbsec = sb->s_security;
485 
486 	return sbsec->behavior == SECURITY_FS_USE_XATTR ||
487 		sbsec->behavior == SECURITY_FS_USE_TRANS ||
488 		sbsec->behavior == SECURITY_FS_USE_TASK ||
489 		sbsec->behavior == SECURITY_FS_USE_NATIVE ||
490 		/* Special handling. Genfs but also in-core setxattr handler */
491 		!strcmp(sb->s_type->name, "sysfs") ||
492 		!strcmp(sb->s_type->name, "pstore") ||
493 		!strcmp(sb->s_type->name, "debugfs") ||
494 		!strcmp(sb->s_type->name, "rootfs");
495 }
496 
497 static int sb_finish_set_opts(struct super_block *sb)
498 {
499 	struct superblock_security_struct *sbsec = sb->s_security;
500 	struct dentry *root = sb->s_root;
501 	struct inode *root_inode = d_backing_inode(root);
502 	int rc = 0;
503 
504 	if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
505 		/* Make sure that the xattr handler exists and that no
506 		   error other than -ENODATA is returned by getxattr on
507 		   the root directory.  -ENODATA is ok, as this may be
508 		   the first boot of the SELinux kernel before we have
509 		   assigned xattr values to the filesystem. */
510 		if (!root_inode->i_op->getxattr) {
511 			printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
512 			       "xattr support\n", sb->s_id, sb->s_type->name);
513 			rc = -EOPNOTSUPP;
514 			goto out;
515 		}
516 		rc = root_inode->i_op->getxattr(root, root_inode,
517 						XATTR_NAME_SELINUX, NULL, 0);
518 		if (rc < 0 && rc != -ENODATA) {
519 			if (rc == -EOPNOTSUPP)
520 				printk(KERN_WARNING "SELinux: (dev %s, type "
521 				       "%s) has no security xattr handler\n",
522 				       sb->s_id, sb->s_type->name);
523 			else
524 				printk(KERN_WARNING "SELinux: (dev %s, type "
525 				       "%s) getxattr errno %d\n", sb->s_id,
526 				       sb->s_type->name, -rc);
527 			goto out;
528 		}
529 	}
530 
531 	if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
532 		printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
533 		       sb->s_id, sb->s_type->name);
534 
535 	sbsec->flags |= SE_SBINITIALIZED;
536 	if (selinux_is_sblabel_mnt(sb))
537 		sbsec->flags |= SBLABEL_MNT;
538 
539 	/* Initialize the root inode. */
540 	rc = inode_doinit_with_dentry(root_inode, root);
541 
542 	/* Initialize any other inodes associated with the superblock, e.g.
543 	   inodes created prior to initial policy load or inodes created
544 	   during get_sb by a pseudo filesystem that directly
545 	   populates itself. */
546 	spin_lock(&sbsec->isec_lock);
547 next_inode:
548 	if (!list_empty(&sbsec->isec_head)) {
549 		struct inode_security_struct *isec =
550 				list_entry(sbsec->isec_head.next,
551 					   struct inode_security_struct, list);
552 		struct inode *inode = isec->inode;
553 		list_del_init(&isec->list);
554 		spin_unlock(&sbsec->isec_lock);
555 		inode = igrab(inode);
556 		if (inode) {
557 			if (!IS_PRIVATE(inode))
558 				inode_doinit(inode);
559 			iput(inode);
560 		}
561 		spin_lock(&sbsec->isec_lock);
562 		goto next_inode;
563 	}
564 	spin_unlock(&sbsec->isec_lock);
565 out:
566 	return rc;
567 }
568 
569 /*
570  * This function should allow an FS to ask what it's mount security
571  * options were so it can use those later for submounts, displaying
572  * mount options, or whatever.
573  */
574 static int selinux_get_mnt_opts(const struct super_block *sb,
575 				struct security_mnt_opts *opts)
576 {
577 	int rc = 0, i;
578 	struct superblock_security_struct *sbsec = sb->s_security;
579 	char *context = NULL;
580 	u32 len;
581 	char tmp;
582 
583 	security_init_mnt_opts(opts);
584 
585 	if (!(sbsec->flags & SE_SBINITIALIZED))
586 		return -EINVAL;
587 
588 	if (!ss_initialized)
589 		return -EINVAL;
590 
591 	/* make sure we always check enough bits to cover the mask */
592 	BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS));
593 
594 	tmp = sbsec->flags & SE_MNTMASK;
595 	/* count the number of mount options for this sb */
596 	for (i = 0; i < NUM_SEL_MNT_OPTS; i++) {
597 		if (tmp & 0x01)
598 			opts->num_mnt_opts++;
599 		tmp >>= 1;
600 	}
601 	/* Check if the Label support flag is set */
602 	if (sbsec->flags & SBLABEL_MNT)
603 		opts->num_mnt_opts++;
604 
605 	opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
606 	if (!opts->mnt_opts) {
607 		rc = -ENOMEM;
608 		goto out_free;
609 	}
610 
611 	opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
612 	if (!opts->mnt_opts_flags) {
613 		rc = -ENOMEM;
614 		goto out_free;
615 	}
616 
617 	i = 0;
618 	if (sbsec->flags & FSCONTEXT_MNT) {
619 		rc = security_sid_to_context(sbsec->sid, &context, &len);
620 		if (rc)
621 			goto out_free;
622 		opts->mnt_opts[i] = context;
623 		opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
624 	}
625 	if (sbsec->flags & CONTEXT_MNT) {
626 		rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
627 		if (rc)
628 			goto out_free;
629 		opts->mnt_opts[i] = context;
630 		opts->mnt_opts_flags[i++] = CONTEXT_MNT;
631 	}
632 	if (sbsec->flags & DEFCONTEXT_MNT) {
633 		rc = security_sid_to_context(sbsec->def_sid, &context, &len);
634 		if (rc)
635 			goto out_free;
636 		opts->mnt_opts[i] = context;
637 		opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
638 	}
639 	if (sbsec->flags & ROOTCONTEXT_MNT) {
640 		struct dentry *root = sbsec->sb->s_root;
641 		struct inode_security_struct *isec = backing_inode_security(root);
642 
643 		rc = security_sid_to_context(isec->sid, &context, &len);
644 		if (rc)
645 			goto out_free;
646 		opts->mnt_opts[i] = context;
647 		opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
648 	}
649 	if (sbsec->flags & SBLABEL_MNT) {
650 		opts->mnt_opts[i] = NULL;
651 		opts->mnt_opts_flags[i++] = SBLABEL_MNT;
652 	}
653 
654 	BUG_ON(i != opts->num_mnt_opts);
655 
656 	return 0;
657 
658 out_free:
659 	security_free_mnt_opts(opts);
660 	return rc;
661 }
662 
663 static int bad_option(struct superblock_security_struct *sbsec, char flag,
664 		      u32 old_sid, u32 new_sid)
665 {
666 	char mnt_flags = sbsec->flags & SE_MNTMASK;
667 
668 	/* check if the old mount command had the same options */
669 	if (sbsec->flags & SE_SBINITIALIZED)
670 		if (!(sbsec->flags & flag) ||
671 		    (old_sid != new_sid))
672 			return 1;
673 
674 	/* check if we were passed the same options twice,
675 	 * aka someone passed context=a,context=b
676 	 */
677 	if (!(sbsec->flags & SE_SBINITIALIZED))
678 		if (mnt_flags & flag)
679 			return 1;
680 	return 0;
681 }
682 
683 /*
684  * Allow filesystems with binary mount data to explicitly set mount point
685  * labeling information.
686  */
687 static int selinux_set_mnt_opts(struct super_block *sb,
688 				struct security_mnt_opts *opts,
689 				unsigned long kern_flags,
690 				unsigned long *set_kern_flags)
691 {
692 	const struct cred *cred = current_cred();
693 	int rc = 0, i;
694 	struct superblock_security_struct *sbsec = sb->s_security;
695 	const char *name = sb->s_type->name;
696 	struct dentry *root = sbsec->sb->s_root;
697 	struct inode_security_struct *root_isec;
698 	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
699 	u32 defcontext_sid = 0;
700 	char **mount_options = opts->mnt_opts;
701 	int *flags = opts->mnt_opts_flags;
702 	int num_opts = opts->num_mnt_opts;
703 
704 	mutex_lock(&sbsec->lock);
705 
706 	if (!ss_initialized) {
707 		if (!num_opts) {
708 			/* Defer initialization until selinux_complete_init,
709 			   after the initial policy is loaded and the security
710 			   server is ready to handle calls. */
711 			goto out;
712 		}
713 		rc = -EINVAL;
714 		printk(KERN_WARNING "SELinux: Unable to set superblock options "
715 			"before the security server is initialized\n");
716 		goto out;
717 	}
718 	if (kern_flags && !set_kern_flags) {
719 		/* Specifying internal flags without providing a place to
720 		 * place the results is not allowed */
721 		rc = -EINVAL;
722 		goto out;
723 	}
724 
725 	/*
726 	 * Binary mount data FS will come through this function twice.  Once
727 	 * from an explicit call and once from the generic calls from the vfs.
728 	 * Since the generic VFS calls will not contain any security mount data
729 	 * we need to skip the double mount verification.
730 	 *
731 	 * This does open a hole in which we will not notice if the first
732 	 * mount using this sb set explict options and a second mount using
733 	 * this sb does not set any security options.  (The first options
734 	 * will be used for both mounts)
735 	 */
736 	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
737 	    && (num_opts == 0))
738 		goto out;
739 
740 	root_isec = backing_inode_security_novalidate(root);
741 
742 	/*
743 	 * parse the mount options, check if they are valid sids.
744 	 * also check if someone is trying to mount the same sb more
745 	 * than once with different security options.
746 	 */
747 	for (i = 0; i < num_opts; i++) {
748 		u32 sid;
749 
750 		if (flags[i] == SBLABEL_MNT)
751 			continue;
752 		rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL);
753 		if (rc) {
754 			printk(KERN_WARNING "SELinux: security_context_str_to_sid"
755 			       "(%s) failed for (dev %s, type %s) errno=%d\n",
756 			       mount_options[i], sb->s_id, name, rc);
757 			goto out;
758 		}
759 		switch (flags[i]) {
760 		case FSCONTEXT_MNT:
761 			fscontext_sid = sid;
762 
763 			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
764 					fscontext_sid))
765 				goto out_double_mount;
766 
767 			sbsec->flags |= FSCONTEXT_MNT;
768 			break;
769 		case CONTEXT_MNT:
770 			context_sid = sid;
771 
772 			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
773 					context_sid))
774 				goto out_double_mount;
775 
776 			sbsec->flags |= CONTEXT_MNT;
777 			break;
778 		case ROOTCONTEXT_MNT:
779 			rootcontext_sid = sid;
780 
781 			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
782 					rootcontext_sid))
783 				goto out_double_mount;
784 
785 			sbsec->flags |= ROOTCONTEXT_MNT;
786 
787 			break;
788 		case DEFCONTEXT_MNT:
789 			defcontext_sid = sid;
790 
791 			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
792 					defcontext_sid))
793 				goto out_double_mount;
794 
795 			sbsec->flags |= DEFCONTEXT_MNT;
796 
797 			break;
798 		default:
799 			rc = -EINVAL;
800 			goto out;
801 		}
802 	}
803 
804 	if (sbsec->flags & SE_SBINITIALIZED) {
805 		/* previously mounted with options, but not on this attempt? */
806 		if ((sbsec->flags & SE_MNTMASK) && !num_opts)
807 			goto out_double_mount;
808 		rc = 0;
809 		goto out;
810 	}
811 
812 	if (strcmp(sb->s_type->name, "proc") == 0)
813 		sbsec->flags |= SE_SBPROC | SE_SBGENFS;
814 
815 	if (!strcmp(sb->s_type->name, "debugfs") ||
816 	    !strcmp(sb->s_type->name, "sysfs") ||
817 	    !strcmp(sb->s_type->name, "pstore"))
818 		sbsec->flags |= SE_SBGENFS;
819 
820 	if (!sbsec->behavior) {
821 		/*
822 		 * Determine the labeling behavior to use for this
823 		 * filesystem type.
824 		 */
825 		rc = security_fs_use(sb);
826 		if (rc) {
827 			printk(KERN_WARNING
828 				"%s: security_fs_use(%s) returned %d\n",
829 					__func__, sb->s_type->name, rc);
830 			goto out;
831 		}
832 	}
833 
834 	/*
835 	 * If this is a user namespace mount, no contexts are allowed
836 	 * on the command line and security labels must be ignored.
837 	 */
838 	if (sb->s_user_ns != &init_user_ns) {
839 		if (context_sid || fscontext_sid || rootcontext_sid ||
840 		    defcontext_sid) {
841 			rc = -EACCES;
842 			goto out;
843 		}
844 		if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
845 			sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
846 			rc = security_transition_sid(current_sid(), current_sid(),
847 						     SECCLASS_FILE, NULL,
848 						     &sbsec->mntpoint_sid);
849 			if (rc)
850 				goto out;
851 		}
852 		goto out_set_opts;
853 	}
854 
855 	/* sets the context of the superblock for the fs being mounted. */
856 	if (fscontext_sid) {
857 		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
858 		if (rc)
859 			goto out;
860 
861 		sbsec->sid = fscontext_sid;
862 	}
863 
864 	/*
865 	 * Switch to using mount point labeling behavior.
866 	 * sets the label used on all file below the mountpoint, and will set
867 	 * the superblock context if not already set.
868 	 */
869 	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
870 		sbsec->behavior = SECURITY_FS_USE_NATIVE;
871 		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
872 	}
873 
874 	if (context_sid) {
875 		if (!fscontext_sid) {
876 			rc = may_context_mount_sb_relabel(context_sid, sbsec,
877 							  cred);
878 			if (rc)
879 				goto out;
880 			sbsec->sid = context_sid;
881 		} else {
882 			rc = may_context_mount_inode_relabel(context_sid, sbsec,
883 							     cred);
884 			if (rc)
885 				goto out;
886 		}
887 		if (!rootcontext_sid)
888 			rootcontext_sid = context_sid;
889 
890 		sbsec->mntpoint_sid = context_sid;
891 		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
892 	}
893 
894 	if (rootcontext_sid) {
895 		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
896 						     cred);
897 		if (rc)
898 			goto out;
899 
900 		root_isec->sid = rootcontext_sid;
901 		root_isec->initialized = LABEL_INITIALIZED;
902 	}
903 
904 	if (defcontext_sid) {
905 		if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
906 			sbsec->behavior != SECURITY_FS_USE_NATIVE) {
907 			rc = -EINVAL;
908 			printk(KERN_WARNING "SELinux: defcontext option is "
909 			       "invalid for this filesystem type\n");
910 			goto out;
911 		}
912 
913 		if (defcontext_sid != sbsec->def_sid) {
914 			rc = may_context_mount_inode_relabel(defcontext_sid,
915 							     sbsec, cred);
916 			if (rc)
917 				goto out;
918 		}
919 
920 		sbsec->def_sid = defcontext_sid;
921 	}
922 
923 out_set_opts:
924 	rc = sb_finish_set_opts(sb);
925 out:
926 	mutex_unlock(&sbsec->lock);
927 	return rc;
928 out_double_mount:
929 	rc = -EINVAL;
930 	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
931 	       "security settings for (dev %s, type %s)\n", sb->s_id, name);
932 	goto out;
933 }
934 
935 static int selinux_cmp_sb_context(const struct super_block *oldsb,
936 				    const struct super_block *newsb)
937 {
938 	struct superblock_security_struct *old = oldsb->s_security;
939 	struct superblock_security_struct *new = newsb->s_security;
940 	char oldflags = old->flags & SE_MNTMASK;
941 	char newflags = new->flags & SE_MNTMASK;
942 
943 	if (oldflags != newflags)
944 		goto mismatch;
945 	if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
946 		goto mismatch;
947 	if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
948 		goto mismatch;
949 	if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
950 		goto mismatch;
951 	if (oldflags & ROOTCONTEXT_MNT) {
952 		struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
953 		struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
954 		if (oldroot->sid != newroot->sid)
955 			goto mismatch;
956 	}
957 	return 0;
958 mismatch:
959 	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, "
960 			    "different security settings for (dev %s, "
961 			    "type %s)\n", newsb->s_id, newsb->s_type->name);
962 	return -EBUSY;
963 }
964 
965 static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
966 					struct super_block *newsb)
967 {
968 	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
969 	struct superblock_security_struct *newsbsec = newsb->s_security;
970 
971 	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
972 	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
973 	int set_rootcontext =	(oldsbsec->flags & ROOTCONTEXT_MNT);
974 
975 	/*
976 	 * if the parent was able to be mounted it clearly had no special lsm
977 	 * mount options.  thus we can safely deal with this superblock later
978 	 */
979 	if (!ss_initialized)
980 		return 0;
981 
982 	/* how can we clone if the old one wasn't set up?? */
983 	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
984 
985 	/* if fs is reusing a sb, make sure that the contexts match */
986 	if (newsbsec->flags & SE_SBINITIALIZED)
987 		return selinux_cmp_sb_context(oldsb, newsb);
988 
989 	mutex_lock(&newsbsec->lock);
990 
991 	newsbsec->flags = oldsbsec->flags;
992 
993 	newsbsec->sid = oldsbsec->sid;
994 	newsbsec->def_sid = oldsbsec->def_sid;
995 	newsbsec->behavior = oldsbsec->behavior;
996 
997 	if (set_context) {
998 		u32 sid = oldsbsec->mntpoint_sid;
999 
1000 		if (!set_fscontext)
1001 			newsbsec->sid = sid;
1002 		if (!set_rootcontext) {
1003 			struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
1004 			newisec->sid = sid;
1005 		}
1006 		newsbsec->mntpoint_sid = sid;
1007 	}
1008 	if (set_rootcontext) {
1009 		const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
1010 		struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
1011 
1012 		newisec->sid = oldisec->sid;
1013 	}
1014 
1015 	sb_finish_set_opts(newsb);
1016 	mutex_unlock(&newsbsec->lock);
1017 	return 0;
1018 }
1019 
1020 static int selinux_parse_opts_str(char *options,
1021 				  struct security_mnt_opts *opts)
1022 {
1023 	char *p;
1024 	char *context = NULL, *defcontext = NULL;
1025 	char *fscontext = NULL, *rootcontext = NULL;
1026 	int rc, num_mnt_opts = 0;
1027 
1028 	opts->num_mnt_opts = 0;
1029 
1030 	/* Standard string-based options. */
1031 	while ((p = strsep(&options, "|")) != NULL) {
1032 		int token;
1033 		substring_t args[MAX_OPT_ARGS];
1034 
1035 		if (!*p)
1036 			continue;
1037 
1038 		token = match_token(p, tokens, args);
1039 
1040 		switch (token) {
1041 		case Opt_context:
1042 			if (context || defcontext) {
1043 				rc = -EINVAL;
1044 				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
1045 				goto out_err;
1046 			}
1047 			context = match_strdup(&args[0]);
1048 			if (!context) {
1049 				rc = -ENOMEM;
1050 				goto out_err;
1051 			}
1052 			break;
1053 
1054 		case Opt_fscontext:
1055 			if (fscontext) {
1056 				rc = -EINVAL;
1057 				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
1058 				goto out_err;
1059 			}
1060 			fscontext = match_strdup(&args[0]);
1061 			if (!fscontext) {
1062 				rc = -ENOMEM;
1063 				goto out_err;
1064 			}
1065 			break;
1066 
1067 		case Opt_rootcontext:
1068 			if (rootcontext) {
1069 				rc = -EINVAL;
1070 				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
1071 				goto out_err;
1072 			}
1073 			rootcontext = match_strdup(&args[0]);
1074 			if (!rootcontext) {
1075 				rc = -ENOMEM;
1076 				goto out_err;
1077 			}
1078 			break;
1079 
1080 		case Opt_defcontext:
1081 			if (context || defcontext) {
1082 				rc = -EINVAL;
1083 				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
1084 				goto out_err;
1085 			}
1086 			defcontext = match_strdup(&args[0]);
1087 			if (!defcontext) {
1088 				rc = -ENOMEM;
1089 				goto out_err;
1090 			}
1091 			break;
1092 		case Opt_labelsupport:
1093 			break;
1094 		default:
1095 			rc = -EINVAL;
1096 			printk(KERN_WARNING "SELinux:  unknown mount option\n");
1097 			goto out_err;
1098 
1099 		}
1100 	}
1101 
1102 	rc = -ENOMEM;
1103 	opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
1104 	if (!opts->mnt_opts)
1105 		goto out_err;
1106 
1107 	opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
1108 	if (!opts->mnt_opts_flags) {
1109 		kfree(opts->mnt_opts);
1110 		goto out_err;
1111 	}
1112 
1113 	if (fscontext) {
1114 		opts->mnt_opts[num_mnt_opts] = fscontext;
1115 		opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
1116 	}
1117 	if (context) {
1118 		opts->mnt_opts[num_mnt_opts] = context;
1119 		opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
1120 	}
1121 	if (rootcontext) {
1122 		opts->mnt_opts[num_mnt_opts] = rootcontext;
1123 		opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
1124 	}
1125 	if (defcontext) {
1126 		opts->mnt_opts[num_mnt_opts] = defcontext;
1127 		opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
1128 	}
1129 
1130 	opts->num_mnt_opts = num_mnt_opts;
1131 	return 0;
1132 
1133 out_err:
1134 	kfree(context);
1135 	kfree(defcontext);
1136 	kfree(fscontext);
1137 	kfree(rootcontext);
1138 	return rc;
1139 }
1140 /*
1141  * string mount options parsing and call set the sbsec
1142  */
1143 static int superblock_doinit(struct super_block *sb, void *data)
1144 {
1145 	int rc = 0;
1146 	char *options = data;
1147 	struct security_mnt_opts opts;
1148 
1149 	security_init_mnt_opts(&opts);
1150 
1151 	if (!data)
1152 		goto out;
1153 
1154 	BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
1155 
1156 	rc = selinux_parse_opts_str(options, &opts);
1157 	if (rc)
1158 		goto out_err;
1159 
1160 out:
1161 	rc = selinux_set_mnt_opts(sb, &opts, 0, NULL);
1162 
1163 out_err:
1164 	security_free_mnt_opts(&opts);
1165 	return rc;
1166 }
1167 
1168 static void selinux_write_opts(struct seq_file *m,
1169 			       struct security_mnt_opts *opts)
1170 {
1171 	int i;
1172 	char *prefix;
1173 
1174 	for (i = 0; i < opts->num_mnt_opts; i++) {
1175 		char *has_comma;
1176 
1177 		if (opts->mnt_opts[i])
1178 			has_comma = strchr(opts->mnt_opts[i], ',');
1179 		else
1180 			has_comma = NULL;
1181 
1182 		switch (opts->mnt_opts_flags[i]) {
1183 		case CONTEXT_MNT:
1184 			prefix = CONTEXT_STR;
1185 			break;
1186 		case FSCONTEXT_MNT:
1187 			prefix = FSCONTEXT_STR;
1188 			break;
1189 		case ROOTCONTEXT_MNT:
1190 			prefix = ROOTCONTEXT_STR;
1191 			break;
1192 		case DEFCONTEXT_MNT:
1193 			prefix = DEFCONTEXT_STR;
1194 			break;
1195 		case SBLABEL_MNT:
1196 			seq_putc(m, ',');
1197 			seq_puts(m, LABELSUPP_STR);
1198 			continue;
1199 		default:
1200 			BUG();
1201 			return;
1202 		};
1203 		/* we need a comma before each option */
1204 		seq_putc(m, ',');
1205 		seq_puts(m, prefix);
1206 		if (has_comma)
1207 			seq_putc(m, '\"');
1208 		seq_escape(m, opts->mnt_opts[i], "\"\n\\");
1209 		if (has_comma)
1210 			seq_putc(m, '\"');
1211 	}
1212 }
1213 
1214 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1215 {
1216 	struct security_mnt_opts opts;
1217 	int rc;
1218 
1219 	rc = selinux_get_mnt_opts(sb, &opts);
1220 	if (rc) {
1221 		/* before policy load we may get EINVAL, don't show anything */
1222 		if (rc == -EINVAL)
1223 			rc = 0;
1224 		return rc;
1225 	}
1226 
1227 	selinux_write_opts(m, &opts);
1228 
1229 	security_free_mnt_opts(&opts);
1230 
1231 	return rc;
1232 }
1233 
1234 static inline u16 inode_mode_to_security_class(umode_t mode)
1235 {
1236 	switch (mode & S_IFMT) {
1237 	case S_IFSOCK:
1238 		return SECCLASS_SOCK_FILE;
1239 	case S_IFLNK:
1240 		return SECCLASS_LNK_FILE;
1241 	case S_IFREG:
1242 		return SECCLASS_FILE;
1243 	case S_IFBLK:
1244 		return SECCLASS_BLK_FILE;
1245 	case S_IFDIR:
1246 		return SECCLASS_DIR;
1247 	case S_IFCHR:
1248 		return SECCLASS_CHR_FILE;
1249 	case S_IFIFO:
1250 		return SECCLASS_FIFO_FILE;
1251 
1252 	}
1253 
1254 	return SECCLASS_FILE;
1255 }
1256 
1257 static inline int default_protocol_stream(int protocol)
1258 {
1259 	return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1260 }
1261 
1262 static inline int default_protocol_dgram(int protocol)
1263 {
1264 	return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1265 }
1266 
1267 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1268 {
1269 	switch (family) {
1270 	case PF_UNIX:
1271 		switch (type) {
1272 		case SOCK_STREAM:
1273 		case SOCK_SEQPACKET:
1274 			return SECCLASS_UNIX_STREAM_SOCKET;
1275 		case SOCK_DGRAM:
1276 			return SECCLASS_UNIX_DGRAM_SOCKET;
1277 		}
1278 		break;
1279 	case PF_INET:
1280 	case PF_INET6:
1281 		switch (type) {
1282 		case SOCK_STREAM:
1283 			if (default_protocol_stream(protocol))
1284 				return SECCLASS_TCP_SOCKET;
1285 			else
1286 				return SECCLASS_RAWIP_SOCKET;
1287 		case SOCK_DGRAM:
1288 			if (default_protocol_dgram(protocol))
1289 				return SECCLASS_UDP_SOCKET;
1290 			else
1291 				return SECCLASS_RAWIP_SOCKET;
1292 		case SOCK_DCCP:
1293 			return SECCLASS_DCCP_SOCKET;
1294 		default:
1295 			return SECCLASS_RAWIP_SOCKET;
1296 		}
1297 		break;
1298 	case PF_NETLINK:
1299 		switch (protocol) {
1300 		case NETLINK_ROUTE:
1301 			return SECCLASS_NETLINK_ROUTE_SOCKET;
1302 		case NETLINK_SOCK_DIAG:
1303 			return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1304 		case NETLINK_NFLOG:
1305 			return SECCLASS_NETLINK_NFLOG_SOCKET;
1306 		case NETLINK_XFRM:
1307 			return SECCLASS_NETLINK_XFRM_SOCKET;
1308 		case NETLINK_SELINUX:
1309 			return SECCLASS_NETLINK_SELINUX_SOCKET;
1310 		case NETLINK_ISCSI:
1311 			return SECCLASS_NETLINK_ISCSI_SOCKET;
1312 		case NETLINK_AUDIT:
1313 			return SECCLASS_NETLINK_AUDIT_SOCKET;
1314 		case NETLINK_FIB_LOOKUP:
1315 			return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET;
1316 		case NETLINK_CONNECTOR:
1317 			return SECCLASS_NETLINK_CONNECTOR_SOCKET;
1318 		case NETLINK_NETFILTER:
1319 			return SECCLASS_NETLINK_NETFILTER_SOCKET;
1320 		case NETLINK_DNRTMSG:
1321 			return SECCLASS_NETLINK_DNRT_SOCKET;
1322 		case NETLINK_KOBJECT_UEVENT:
1323 			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1324 		case NETLINK_GENERIC:
1325 			return SECCLASS_NETLINK_GENERIC_SOCKET;
1326 		case NETLINK_SCSITRANSPORT:
1327 			return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET;
1328 		case NETLINK_RDMA:
1329 			return SECCLASS_NETLINK_RDMA_SOCKET;
1330 		case NETLINK_CRYPTO:
1331 			return SECCLASS_NETLINK_CRYPTO_SOCKET;
1332 		default:
1333 			return SECCLASS_NETLINK_SOCKET;
1334 		}
1335 	case PF_PACKET:
1336 		return SECCLASS_PACKET_SOCKET;
1337 	case PF_KEY:
1338 		return SECCLASS_KEY_SOCKET;
1339 	case PF_APPLETALK:
1340 		return SECCLASS_APPLETALK_SOCKET;
1341 	}
1342 
1343 	return SECCLASS_SOCKET;
1344 }
1345 
1346 static int selinux_genfs_get_sid(struct dentry *dentry,
1347 				 u16 tclass,
1348 				 u16 flags,
1349 				 u32 *sid)
1350 {
1351 	int rc;
1352 	struct super_block *sb = dentry->d_sb;
1353 	char *buffer, *path;
1354 
1355 	buffer = (char *)__get_free_page(GFP_KERNEL);
1356 	if (!buffer)
1357 		return -ENOMEM;
1358 
1359 	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1360 	if (IS_ERR(path))
1361 		rc = PTR_ERR(path);
1362 	else {
1363 		if (flags & SE_SBPROC) {
1364 			/* each process gets a /proc/PID/ entry. Strip off the
1365 			 * PID part to get a valid selinux labeling.
1366 			 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1367 			while (path[1] >= '0' && path[1] <= '9') {
1368 				path[1] = '/';
1369 				path++;
1370 			}
1371 		}
1372 		rc = security_genfs_sid(sb->s_type->name, path, tclass, sid);
1373 	}
1374 	free_page((unsigned long)buffer);
1375 	return rc;
1376 }
1377 
1378 /* The inode's security attributes must be initialized before first use. */
1379 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1380 {
1381 	struct superblock_security_struct *sbsec = NULL;
1382 	struct inode_security_struct *isec = inode->i_security;
1383 	u32 sid;
1384 	struct dentry *dentry;
1385 #define INITCONTEXTLEN 255
1386 	char *context = NULL;
1387 	unsigned len = 0;
1388 	int rc = 0;
1389 
1390 	if (isec->initialized == LABEL_INITIALIZED)
1391 		goto out;
1392 
1393 	mutex_lock(&isec->lock);
1394 	if (isec->initialized == LABEL_INITIALIZED)
1395 		goto out_unlock;
1396 
1397 	sbsec = inode->i_sb->s_security;
1398 	if (!(sbsec->flags & SE_SBINITIALIZED)) {
1399 		/* Defer initialization until selinux_complete_init,
1400 		   after the initial policy is loaded and the security
1401 		   server is ready to handle calls. */
1402 		spin_lock(&sbsec->isec_lock);
1403 		if (list_empty(&isec->list))
1404 			list_add(&isec->list, &sbsec->isec_head);
1405 		spin_unlock(&sbsec->isec_lock);
1406 		goto out_unlock;
1407 	}
1408 
1409 	switch (sbsec->behavior) {
1410 	case SECURITY_FS_USE_NATIVE:
1411 		break;
1412 	case SECURITY_FS_USE_XATTR:
1413 		if (!inode->i_op->getxattr) {
1414 			isec->sid = sbsec->def_sid;
1415 			break;
1416 		}
1417 
1418 		/* Need a dentry, since the xattr API requires one.
1419 		   Life would be simpler if we could just pass the inode. */
1420 		if (opt_dentry) {
1421 			/* Called from d_instantiate or d_splice_alias. */
1422 			dentry = dget(opt_dentry);
1423 		} else {
1424 			/* Called from selinux_complete_init, try to find a dentry. */
1425 			dentry = d_find_alias(inode);
1426 		}
1427 		if (!dentry) {
1428 			/*
1429 			 * this is can be hit on boot when a file is accessed
1430 			 * before the policy is loaded.  When we load policy we
1431 			 * may find inodes that have no dentry on the
1432 			 * sbsec->isec_head list.  No reason to complain as these
1433 			 * will get fixed up the next time we go through
1434 			 * inode_doinit with a dentry, before these inodes could
1435 			 * be used again by userspace.
1436 			 */
1437 			goto out_unlock;
1438 		}
1439 
1440 		len = INITCONTEXTLEN;
1441 		context = kmalloc(len+1, GFP_NOFS);
1442 		if (!context) {
1443 			rc = -ENOMEM;
1444 			dput(dentry);
1445 			goto out_unlock;
1446 		}
1447 		context[len] = '\0';
1448 		rc = inode->i_op->getxattr(dentry, inode, XATTR_NAME_SELINUX,
1449 					   context, len);
1450 		if (rc == -ERANGE) {
1451 			kfree(context);
1452 
1453 			/* Need a larger buffer.  Query for the right size. */
1454 			rc = inode->i_op->getxattr(dentry, inode, XATTR_NAME_SELINUX,
1455 						   NULL, 0);
1456 			if (rc < 0) {
1457 				dput(dentry);
1458 				goto out_unlock;
1459 			}
1460 			len = rc;
1461 			context = kmalloc(len+1, GFP_NOFS);
1462 			if (!context) {
1463 				rc = -ENOMEM;
1464 				dput(dentry);
1465 				goto out_unlock;
1466 			}
1467 			context[len] = '\0';
1468 			rc = inode->i_op->getxattr(dentry, inode,
1469 						   XATTR_NAME_SELINUX,
1470 						   context, len);
1471 		}
1472 		dput(dentry);
1473 		if (rc < 0) {
1474 			if (rc != -ENODATA) {
1475 				printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1476 				       "%d for dev=%s ino=%ld\n", __func__,
1477 				       -rc, inode->i_sb->s_id, inode->i_ino);
1478 				kfree(context);
1479 				goto out_unlock;
1480 			}
1481 			/* Map ENODATA to the default file SID */
1482 			sid = sbsec->def_sid;
1483 			rc = 0;
1484 		} else {
1485 			rc = security_context_to_sid_default(context, rc, &sid,
1486 							     sbsec->def_sid,
1487 							     GFP_NOFS);
1488 			if (rc) {
1489 				char *dev = inode->i_sb->s_id;
1490 				unsigned long ino = inode->i_ino;
1491 
1492 				if (rc == -EINVAL) {
1493 					if (printk_ratelimit())
1494 						printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
1495 							"context=%s.  This indicates you may need to relabel the inode or the "
1496 							"filesystem in question.\n", ino, dev, context);
1497 				} else {
1498 					printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
1499 					       "returned %d for dev=%s ino=%ld\n",
1500 					       __func__, context, -rc, dev, ino);
1501 				}
1502 				kfree(context);
1503 				/* Leave with the unlabeled SID */
1504 				rc = 0;
1505 				break;
1506 			}
1507 		}
1508 		kfree(context);
1509 		isec->sid = sid;
1510 		break;
1511 	case SECURITY_FS_USE_TASK:
1512 		isec->sid = isec->task_sid;
1513 		break;
1514 	case SECURITY_FS_USE_TRANS:
1515 		/* Default to the fs SID. */
1516 		isec->sid = sbsec->sid;
1517 
1518 		/* Try to obtain a transition SID. */
1519 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
1520 		rc = security_transition_sid(isec->task_sid, sbsec->sid,
1521 					     isec->sclass, NULL, &sid);
1522 		if (rc)
1523 			goto out_unlock;
1524 		isec->sid = sid;
1525 		break;
1526 	case SECURITY_FS_USE_MNTPOINT:
1527 		isec->sid = sbsec->mntpoint_sid;
1528 		break;
1529 	default:
1530 		/* Default to the fs superblock SID. */
1531 		isec->sid = sbsec->sid;
1532 
1533 		if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) {
1534 			/* We must have a dentry to determine the label on
1535 			 * procfs inodes */
1536 			if (opt_dentry)
1537 				/* Called from d_instantiate or
1538 				 * d_splice_alias. */
1539 				dentry = dget(opt_dentry);
1540 			else
1541 				/* Called from selinux_complete_init, try to
1542 				 * find a dentry. */
1543 				dentry = d_find_alias(inode);
1544 			/*
1545 			 * This can be hit on boot when a file is accessed
1546 			 * before the policy is loaded.  When we load policy we
1547 			 * may find inodes that have no dentry on the
1548 			 * sbsec->isec_head list.  No reason to complain as
1549 			 * these will get fixed up the next time we go through
1550 			 * inode_doinit() with a dentry, before these inodes
1551 			 * could be used again by userspace.
1552 			 */
1553 			if (!dentry)
1554 				goto out_unlock;
1555 			isec->sclass = inode_mode_to_security_class(inode->i_mode);
1556 			rc = selinux_genfs_get_sid(dentry, isec->sclass,
1557 						   sbsec->flags, &sid);
1558 			dput(dentry);
1559 			if (rc)
1560 				goto out_unlock;
1561 			isec->sid = sid;
1562 		}
1563 		break;
1564 	}
1565 
1566 	isec->initialized = LABEL_INITIALIZED;
1567 
1568 out_unlock:
1569 	mutex_unlock(&isec->lock);
1570 out:
1571 	if (isec->sclass == SECCLASS_FILE)
1572 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
1573 	return rc;
1574 }
1575 
1576 /* Convert a Linux signal to an access vector. */
1577 static inline u32 signal_to_av(int sig)
1578 {
1579 	u32 perm = 0;
1580 
1581 	switch (sig) {
1582 	case SIGCHLD:
1583 		/* Commonly granted from child to parent. */
1584 		perm = PROCESS__SIGCHLD;
1585 		break;
1586 	case SIGKILL:
1587 		/* Cannot be caught or ignored */
1588 		perm = PROCESS__SIGKILL;
1589 		break;
1590 	case SIGSTOP:
1591 		/* Cannot be caught or ignored */
1592 		perm = PROCESS__SIGSTOP;
1593 		break;
1594 	default:
1595 		/* All other signals. */
1596 		perm = PROCESS__SIGNAL;
1597 		break;
1598 	}
1599 
1600 	return perm;
1601 }
1602 
1603 /*
1604  * Check permission between a pair of credentials
1605  * fork check, ptrace check, etc.
1606  */
1607 static int cred_has_perm(const struct cred *actor,
1608 			 const struct cred *target,
1609 			 u32 perms)
1610 {
1611 	u32 asid = cred_sid(actor), tsid = cred_sid(target);
1612 
1613 	return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1614 }
1615 
1616 /*
1617  * Check permission between a pair of tasks, e.g. signal checks,
1618  * fork check, ptrace check, etc.
1619  * tsk1 is the actor and tsk2 is the target
1620  * - this uses the default subjective creds of tsk1
1621  */
1622 static int task_has_perm(const struct task_struct *tsk1,
1623 			 const struct task_struct *tsk2,
1624 			 u32 perms)
1625 {
1626 	const struct task_security_struct *__tsec1, *__tsec2;
1627 	u32 sid1, sid2;
1628 
1629 	rcu_read_lock();
1630 	__tsec1 = __task_cred(tsk1)->security;	sid1 = __tsec1->sid;
1631 	__tsec2 = __task_cred(tsk2)->security;	sid2 = __tsec2->sid;
1632 	rcu_read_unlock();
1633 	return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1634 }
1635 
1636 /*
1637  * Check permission between current and another task, e.g. signal checks,
1638  * fork check, ptrace check, etc.
1639  * current is the actor and tsk2 is the target
1640  * - this uses current's subjective creds
1641  */
1642 static int current_has_perm(const struct task_struct *tsk,
1643 			    u32 perms)
1644 {
1645 	u32 sid, tsid;
1646 
1647 	sid = current_sid();
1648 	tsid = task_sid(tsk);
1649 	return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1650 }
1651 
1652 #if CAP_LAST_CAP > 63
1653 #error Fix SELinux to handle capabilities > 63.
1654 #endif
1655 
1656 /* Check whether a task is allowed to use a capability. */
1657 static int cred_has_capability(const struct cred *cred,
1658 			       int cap, int audit, bool initns)
1659 {
1660 	struct common_audit_data ad;
1661 	struct av_decision avd;
1662 	u16 sclass;
1663 	u32 sid = cred_sid(cred);
1664 	u32 av = CAP_TO_MASK(cap);
1665 	int rc;
1666 
1667 	ad.type = LSM_AUDIT_DATA_CAP;
1668 	ad.u.cap = cap;
1669 
1670 	switch (CAP_TO_INDEX(cap)) {
1671 	case 0:
1672 		sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1673 		break;
1674 	case 1:
1675 		sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1676 		break;
1677 	default:
1678 		printk(KERN_ERR
1679 		       "SELinux:  out of range capability %d\n", cap);
1680 		BUG();
1681 		return -EINVAL;
1682 	}
1683 
1684 	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1685 	if (audit == SECURITY_CAP_AUDIT) {
1686 		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
1687 		if (rc2)
1688 			return rc2;
1689 	}
1690 	return rc;
1691 }
1692 
1693 /* Check whether a task is allowed to use a system operation. */
1694 static int task_has_system(struct task_struct *tsk,
1695 			   u32 perms)
1696 {
1697 	u32 sid = task_sid(tsk);
1698 
1699 	return avc_has_perm(sid, SECINITSID_KERNEL,
1700 			    SECCLASS_SYSTEM, perms, NULL);
1701 }
1702 
1703 /* Check whether a task has a particular permission to an inode.
1704    The 'adp' parameter is optional and allows other audit
1705    data to be passed (e.g. the dentry). */
1706 static int inode_has_perm(const struct cred *cred,
1707 			  struct inode *inode,
1708 			  u32 perms,
1709 			  struct common_audit_data *adp)
1710 {
1711 	struct inode_security_struct *isec;
1712 	u32 sid;
1713 
1714 	validate_creds(cred);
1715 
1716 	if (unlikely(IS_PRIVATE(inode)))
1717 		return 0;
1718 
1719 	sid = cred_sid(cred);
1720 	isec = inode->i_security;
1721 
1722 	return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1723 }
1724 
1725 /* Same as inode_has_perm, but pass explicit audit data containing
1726    the dentry to help the auditing code to more easily generate the
1727    pathname if needed. */
1728 static inline int dentry_has_perm(const struct cred *cred,
1729 				  struct dentry *dentry,
1730 				  u32 av)
1731 {
1732 	struct inode *inode = d_backing_inode(dentry);
1733 	struct common_audit_data ad;
1734 
1735 	ad.type = LSM_AUDIT_DATA_DENTRY;
1736 	ad.u.dentry = dentry;
1737 	__inode_security_revalidate(inode, dentry, true);
1738 	return inode_has_perm(cred, inode, av, &ad);
1739 }
1740 
1741 /* Same as inode_has_perm, but pass explicit audit data containing
1742    the path to help the auditing code to more easily generate the
1743    pathname if needed. */
1744 static inline int path_has_perm(const struct cred *cred,
1745 				const struct path *path,
1746 				u32 av)
1747 {
1748 	struct inode *inode = d_backing_inode(path->dentry);
1749 	struct common_audit_data ad;
1750 
1751 	ad.type = LSM_AUDIT_DATA_PATH;
1752 	ad.u.path = *path;
1753 	__inode_security_revalidate(inode, path->dentry, true);
1754 	return inode_has_perm(cred, inode, av, &ad);
1755 }
1756 
1757 /* Same as path_has_perm, but uses the inode from the file struct. */
1758 static inline int file_path_has_perm(const struct cred *cred,
1759 				     struct file *file,
1760 				     u32 av)
1761 {
1762 	struct common_audit_data ad;
1763 
1764 	ad.type = LSM_AUDIT_DATA_FILE;
1765 	ad.u.file = file;
1766 	return inode_has_perm(cred, file_inode(file), av, &ad);
1767 }
1768 
1769 /* Check whether a task can use an open file descriptor to
1770    access an inode in a given way.  Check access to the
1771    descriptor itself, and then use dentry_has_perm to
1772    check a particular permission to the file.
1773    Access to the descriptor is implicitly granted if it
1774    has the same SID as the process.  If av is zero, then
1775    access to the file is not checked, e.g. for cases
1776    where only the descriptor is affected like seek. */
1777 static int file_has_perm(const struct cred *cred,
1778 			 struct file *file,
1779 			 u32 av)
1780 {
1781 	struct file_security_struct *fsec = file->f_security;
1782 	struct inode *inode = file_inode(file);
1783 	struct common_audit_data ad;
1784 	u32 sid = cred_sid(cred);
1785 	int rc;
1786 
1787 	ad.type = LSM_AUDIT_DATA_FILE;
1788 	ad.u.file = file;
1789 
1790 	if (sid != fsec->sid) {
1791 		rc = avc_has_perm(sid, fsec->sid,
1792 				  SECCLASS_FD,
1793 				  FD__USE,
1794 				  &ad);
1795 		if (rc)
1796 			goto out;
1797 	}
1798 
1799 	/* av is zero if only checking access to the descriptor. */
1800 	rc = 0;
1801 	if (av)
1802 		rc = inode_has_perm(cred, inode, av, &ad);
1803 
1804 out:
1805 	return rc;
1806 }
1807 
1808 /*
1809  * Determine the label for an inode that might be unioned.
1810  */
1811 static int
1812 selinux_determine_inode_label(const struct task_security_struct *tsec,
1813 				 struct inode *dir,
1814 				 const struct qstr *name, u16 tclass,
1815 				 u32 *_new_isid)
1816 {
1817 	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
1818 
1819 	if ((sbsec->flags & SE_SBINITIALIZED) &&
1820 	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
1821 		*_new_isid = sbsec->mntpoint_sid;
1822 	} else if ((sbsec->flags & SBLABEL_MNT) &&
1823 		   tsec->create_sid) {
1824 		*_new_isid = tsec->create_sid;
1825 	} else {
1826 		const struct inode_security_struct *dsec = inode_security(dir);
1827 		return security_transition_sid(tsec->sid, dsec->sid, tclass,
1828 					       name, _new_isid);
1829 	}
1830 
1831 	return 0;
1832 }
1833 
1834 /* Check whether a task can create a file. */
1835 static int may_create(struct inode *dir,
1836 		      struct dentry *dentry,
1837 		      u16 tclass)
1838 {
1839 	const struct task_security_struct *tsec = current_security();
1840 	struct inode_security_struct *dsec;
1841 	struct superblock_security_struct *sbsec;
1842 	u32 sid, newsid;
1843 	struct common_audit_data ad;
1844 	int rc;
1845 
1846 	dsec = inode_security(dir);
1847 	sbsec = dir->i_sb->s_security;
1848 
1849 	sid = tsec->sid;
1850 
1851 	ad.type = LSM_AUDIT_DATA_DENTRY;
1852 	ad.u.dentry = dentry;
1853 
1854 	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1855 			  DIR__ADD_NAME | DIR__SEARCH,
1856 			  &ad);
1857 	if (rc)
1858 		return rc;
1859 
1860 	rc = selinux_determine_inode_label(current_security(), dir,
1861 					   &dentry->d_name, tclass, &newsid);
1862 	if (rc)
1863 		return rc;
1864 
1865 	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1866 	if (rc)
1867 		return rc;
1868 
1869 	return avc_has_perm(newsid, sbsec->sid,
1870 			    SECCLASS_FILESYSTEM,
1871 			    FILESYSTEM__ASSOCIATE, &ad);
1872 }
1873 
1874 /* Check whether a task can create a key. */
1875 static int may_create_key(u32 ksid,
1876 			  struct task_struct *ctx)
1877 {
1878 	u32 sid = task_sid(ctx);
1879 
1880 	return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1881 }
1882 
1883 #define MAY_LINK	0
1884 #define MAY_UNLINK	1
1885 #define MAY_RMDIR	2
1886 
1887 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1888 static int may_link(struct inode *dir,
1889 		    struct dentry *dentry,
1890 		    int kind)
1891 
1892 {
1893 	struct inode_security_struct *dsec, *isec;
1894 	struct common_audit_data ad;
1895 	u32 sid = current_sid();
1896 	u32 av;
1897 	int rc;
1898 
1899 	dsec = inode_security(dir);
1900 	isec = backing_inode_security(dentry);
1901 
1902 	ad.type = LSM_AUDIT_DATA_DENTRY;
1903 	ad.u.dentry = dentry;
1904 
1905 	av = DIR__SEARCH;
1906 	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1907 	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1908 	if (rc)
1909 		return rc;
1910 
1911 	switch (kind) {
1912 	case MAY_LINK:
1913 		av = FILE__LINK;
1914 		break;
1915 	case MAY_UNLINK:
1916 		av = FILE__UNLINK;
1917 		break;
1918 	case MAY_RMDIR:
1919 		av = DIR__RMDIR;
1920 		break;
1921 	default:
1922 		printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
1923 			__func__, kind);
1924 		return 0;
1925 	}
1926 
1927 	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1928 	return rc;
1929 }
1930 
1931 static inline int may_rename(struct inode *old_dir,
1932 			     struct dentry *old_dentry,
1933 			     struct inode *new_dir,
1934 			     struct dentry *new_dentry)
1935 {
1936 	struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1937 	struct common_audit_data ad;
1938 	u32 sid = current_sid();
1939 	u32 av;
1940 	int old_is_dir, new_is_dir;
1941 	int rc;
1942 
1943 	old_dsec = inode_security(old_dir);
1944 	old_isec = backing_inode_security(old_dentry);
1945 	old_is_dir = d_is_dir(old_dentry);
1946 	new_dsec = inode_security(new_dir);
1947 
1948 	ad.type = LSM_AUDIT_DATA_DENTRY;
1949 
1950 	ad.u.dentry = old_dentry;
1951 	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1952 			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1953 	if (rc)
1954 		return rc;
1955 	rc = avc_has_perm(sid, old_isec->sid,
1956 			  old_isec->sclass, FILE__RENAME, &ad);
1957 	if (rc)
1958 		return rc;
1959 	if (old_is_dir && new_dir != old_dir) {
1960 		rc = avc_has_perm(sid, old_isec->sid,
1961 				  old_isec->sclass, DIR__REPARENT, &ad);
1962 		if (rc)
1963 			return rc;
1964 	}
1965 
1966 	ad.u.dentry = new_dentry;
1967 	av = DIR__ADD_NAME | DIR__SEARCH;
1968 	if (d_is_positive(new_dentry))
1969 		av |= DIR__REMOVE_NAME;
1970 	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1971 	if (rc)
1972 		return rc;
1973 	if (d_is_positive(new_dentry)) {
1974 		new_isec = backing_inode_security(new_dentry);
1975 		new_is_dir = d_is_dir(new_dentry);
1976 		rc = avc_has_perm(sid, new_isec->sid,
1977 				  new_isec->sclass,
1978 				  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1979 		if (rc)
1980 			return rc;
1981 	}
1982 
1983 	return 0;
1984 }
1985 
1986 /* Check whether a task can perform a filesystem operation. */
1987 static int superblock_has_perm(const struct cred *cred,
1988 			       struct super_block *sb,
1989 			       u32 perms,
1990 			       struct common_audit_data *ad)
1991 {
1992 	struct superblock_security_struct *sbsec;
1993 	u32 sid = cred_sid(cred);
1994 
1995 	sbsec = sb->s_security;
1996 	return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1997 }
1998 
1999 /* Convert a Linux mode and permission mask to an access vector. */
2000 static inline u32 file_mask_to_av(int mode, int mask)
2001 {
2002 	u32 av = 0;
2003 
2004 	if (!S_ISDIR(mode)) {
2005 		if (mask & MAY_EXEC)
2006 			av |= FILE__EXECUTE;
2007 		if (mask & MAY_READ)
2008 			av |= FILE__READ;
2009 
2010 		if (mask & MAY_APPEND)
2011 			av |= FILE__APPEND;
2012 		else if (mask & MAY_WRITE)
2013 			av |= FILE__WRITE;
2014 
2015 	} else {
2016 		if (mask & MAY_EXEC)
2017 			av |= DIR__SEARCH;
2018 		if (mask & MAY_WRITE)
2019 			av |= DIR__WRITE;
2020 		if (mask & MAY_READ)
2021 			av |= DIR__READ;
2022 	}
2023 
2024 	return av;
2025 }
2026 
2027 /* Convert a Linux file to an access vector. */
2028 static inline u32 file_to_av(struct file *file)
2029 {
2030 	u32 av = 0;
2031 
2032 	if (file->f_mode & FMODE_READ)
2033 		av |= FILE__READ;
2034 	if (file->f_mode & FMODE_WRITE) {
2035 		if (file->f_flags & O_APPEND)
2036 			av |= FILE__APPEND;
2037 		else
2038 			av |= FILE__WRITE;
2039 	}
2040 	if (!av) {
2041 		/*
2042 		 * Special file opened with flags 3 for ioctl-only use.
2043 		 */
2044 		av = FILE__IOCTL;
2045 	}
2046 
2047 	return av;
2048 }
2049 
2050 /*
2051  * Convert a file to an access vector and include the correct open
2052  * open permission.
2053  */
2054 static inline u32 open_file_to_av(struct file *file)
2055 {
2056 	u32 av = file_to_av(file);
2057 
2058 	if (selinux_policycap_openperm)
2059 		av |= FILE__OPEN;
2060 
2061 	return av;
2062 }
2063 
2064 /* Hook functions begin here. */
2065 
2066 static int selinux_binder_set_context_mgr(struct task_struct *mgr)
2067 {
2068 	u32 mysid = current_sid();
2069 	u32 mgrsid = task_sid(mgr);
2070 
2071 	return avc_has_perm(mysid, mgrsid, SECCLASS_BINDER,
2072 			    BINDER__SET_CONTEXT_MGR, NULL);
2073 }
2074 
2075 static int selinux_binder_transaction(struct task_struct *from,
2076 				      struct task_struct *to)
2077 {
2078 	u32 mysid = current_sid();
2079 	u32 fromsid = task_sid(from);
2080 	u32 tosid = task_sid(to);
2081 	int rc;
2082 
2083 	if (mysid != fromsid) {
2084 		rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER,
2085 				  BINDER__IMPERSONATE, NULL);
2086 		if (rc)
2087 			return rc;
2088 	}
2089 
2090 	return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__CALL,
2091 			    NULL);
2092 }
2093 
2094 static int selinux_binder_transfer_binder(struct task_struct *from,
2095 					  struct task_struct *to)
2096 {
2097 	u32 fromsid = task_sid(from);
2098 	u32 tosid = task_sid(to);
2099 
2100 	return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER,
2101 			    NULL);
2102 }
2103 
2104 static int selinux_binder_transfer_file(struct task_struct *from,
2105 					struct task_struct *to,
2106 					struct file *file)
2107 {
2108 	u32 sid = task_sid(to);
2109 	struct file_security_struct *fsec = file->f_security;
2110 	struct dentry *dentry = file->f_path.dentry;
2111 	struct inode_security_struct *isec;
2112 	struct common_audit_data ad;
2113 	int rc;
2114 
2115 	ad.type = LSM_AUDIT_DATA_PATH;
2116 	ad.u.path = file->f_path;
2117 
2118 	if (sid != fsec->sid) {
2119 		rc = avc_has_perm(sid, fsec->sid,
2120 				  SECCLASS_FD,
2121 				  FD__USE,
2122 				  &ad);
2123 		if (rc)
2124 			return rc;
2125 	}
2126 
2127 	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2128 		return 0;
2129 
2130 	isec = backing_inode_security(dentry);
2131 	return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
2132 			    &ad);
2133 }
2134 
2135 static int selinux_ptrace_access_check(struct task_struct *child,
2136 				     unsigned int mode)
2137 {
2138 	if (mode & PTRACE_MODE_READ) {
2139 		u32 sid = current_sid();
2140 		u32 csid = task_sid(child);
2141 		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
2142 	}
2143 
2144 	return current_has_perm(child, PROCESS__PTRACE);
2145 }
2146 
2147 static int selinux_ptrace_traceme(struct task_struct *parent)
2148 {
2149 	return task_has_perm(parent, current, PROCESS__PTRACE);
2150 }
2151 
2152 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
2153 			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
2154 {
2155 	return current_has_perm(target, PROCESS__GETCAP);
2156 }
2157 
2158 static int selinux_capset(struct cred *new, const struct cred *old,
2159 			  const kernel_cap_t *effective,
2160 			  const kernel_cap_t *inheritable,
2161 			  const kernel_cap_t *permitted)
2162 {
2163 	return cred_has_perm(old, new, PROCESS__SETCAP);
2164 }
2165 
2166 /*
2167  * (This comment used to live with the selinux_task_setuid hook,
2168  * which was removed).
2169  *
2170  * Since setuid only affects the current process, and since the SELinux
2171  * controls are not based on the Linux identity attributes, SELinux does not
2172  * need to control this operation.  However, SELinux does control the use of
2173  * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
2174  */
2175 
2176 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
2177 			   int cap, int audit)
2178 {
2179 	return cred_has_capability(cred, cap, audit, ns == &init_user_ns);
2180 }
2181 
2182 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
2183 {
2184 	const struct cred *cred = current_cred();
2185 	int rc = 0;
2186 
2187 	if (!sb)
2188 		return 0;
2189 
2190 	switch (cmds) {
2191 	case Q_SYNC:
2192 	case Q_QUOTAON:
2193 	case Q_QUOTAOFF:
2194 	case Q_SETINFO:
2195 	case Q_SETQUOTA:
2196 		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2197 		break;
2198 	case Q_GETFMT:
2199 	case Q_GETINFO:
2200 	case Q_GETQUOTA:
2201 		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2202 		break;
2203 	default:
2204 		rc = 0;  /* let the kernel handle invalid cmds */
2205 		break;
2206 	}
2207 	return rc;
2208 }
2209 
2210 static int selinux_quota_on(struct dentry *dentry)
2211 {
2212 	const struct cred *cred = current_cred();
2213 
2214 	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
2215 }
2216 
2217 static int selinux_syslog(int type)
2218 {
2219 	int rc;
2220 
2221 	switch (type) {
2222 	case SYSLOG_ACTION_READ_ALL:	/* Read last kernel messages */
2223 	case SYSLOG_ACTION_SIZE_BUFFER:	/* Return size of the log buffer */
2224 		rc = task_has_system(current, SYSTEM__SYSLOG_READ);
2225 		break;
2226 	case SYSLOG_ACTION_CONSOLE_OFF:	/* Disable logging to console */
2227 	case SYSLOG_ACTION_CONSOLE_ON:	/* Enable logging to console */
2228 	/* Set level of messages printed to console */
2229 	case SYSLOG_ACTION_CONSOLE_LEVEL:
2230 		rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
2231 		break;
2232 	case SYSLOG_ACTION_CLOSE:	/* Close log */
2233 	case SYSLOG_ACTION_OPEN:	/* Open log */
2234 	case SYSLOG_ACTION_READ:	/* Read from log */
2235 	case SYSLOG_ACTION_READ_CLEAR:	/* Read/clear last kernel messages */
2236 	case SYSLOG_ACTION_CLEAR:	/* Clear ring buffer */
2237 	default:
2238 		rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
2239 		break;
2240 	}
2241 	return rc;
2242 }
2243 
2244 /*
2245  * Check that a process has enough memory to allocate a new virtual
2246  * mapping. 0 means there is enough memory for the allocation to
2247  * succeed and -ENOMEM implies there is not.
2248  *
2249  * Do not audit the selinux permission check, as this is applied to all
2250  * processes that allocate mappings.
2251  */
2252 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2253 {
2254 	int rc, cap_sys_admin = 0;
2255 
2256 	rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2257 				 SECURITY_CAP_NOAUDIT, true);
2258 	if (rc == 0)
2259 		cap_sys_admin = 1;
2260 
2261 	return cap_sys_admin;
2262 }
2263 
2264 /* binprm security operations */
2265 
2266 static u32 ptrace_parent_sid(struct task_struct *task)
2267 {
2268 	u32 sid = 0;
2269 	struct task_struct *tracer;
2270 
2271 	rcu_read_lock();
2272 	tracer = ptrace_parent(task);
2273 	if (tracer)
2274 		sid = task_sid(tracer);
2275 	rcu_read_unlock();
2276 
2277 	return sid;
2278 }
2279 
2280 static int check_nnp_nosuid(const struct linux_binprm *bprm,
2281 			    const struct task_security_struct *old_tsec,
2282 			    const struct task_security_struct *new_tsec)
2283 {
2284 	int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2285 	int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2286 	int rc;
2287 
2288 	if (!nnp && !nosuid)
2289 		return 0; /* neither NNP nor nosuid */
2290 
2291 	if (new_tsec->sid == old_tsec->sid)
2292 		return 0; /* No change in credentials */
2293 
2294 	/*
2295 	 * The only transitions we permit under NNP or nosuid
2296 	 * are transitions to bounded SIDs, i.e. SIDs that are
2297 	 * guaranteed to only be allowed a subset of the permissions
2298 	 * of the current SID.
2299 	 */
2300 	rc = security_bounded_transition(old_tsec->sid, new_tsec->sid);
2301 	if (rc) {
2302 		/*
2303 		 * On failure, preserve the errno values for NNP vs nosuid.
2304 		 * NNP:  Operation not permitted for caller.
2305 		 * nosuid:  Permission denied to file.
2306 		 */
2307 		if (nnp)
2308 			return -EPERM;
2309 		else
2310 			return -EACCES;
2311 	}
2312 	return 0;
2313 }
2314 
2315 static int selinux_bprm_set_creds(struct linux_binprm *bprm)
2316 {
2317 	const struct task_security_struct *old_tsec;
2318 	struct task_security_struct *new_tsec;
2319 	struct inode_security_struct *isec;
2320 	struct common_audit_data ad;
2321 	struct inode *inode = file_inode(bprm->file);
2322 	int rc;
2323 
2324 	/* SELinux context only depends on initial program or script and not
2325 	 * the script interpreter */
2326 	if (bprm->cred_prepared)
2327 		return 0;
2328 
2329 	old_tsec = current_security();
2330 	new_tsec = bprm->cred->security;
2331 	isec = inode_security(inode);
2332 
2333 	/* Default to the current task SID. */
2334 	new_tsec->sid = old_tsec->sid;
2335 	new_tsec->osid = old_tsec->sid;
2336 
2337 	/* Reset fs, key, and sock SIDs on execve. */
2338 	new_tsec->create_sid = 0;
2339 	new_tsec->keycreate_sid = 0;
2340 	new_tsec->sockcreate_sid = 0;
2341 
2342 	if (old_tsec->exec_sid) {
2343 		new_tsec->sid = old_tsec->exec_sid;
2344 		/* Reset exec SID on execve. */
2345 		new_tsec->exec_sid = 0;
2346 
2347 		/* Fail on NNP or nosuid if not an allowed transition. */
2348 		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2349 		if (rc)
2350 			return rc;
2351 	} else {
2352 		/* Check for a default transition on this program. */
2353 		rc = security_transition_sid(old_tsec->sid, isec->sid,
2354 					     SECCLASS_PROCESS, NULL,
2355 					     &new_tsec->sid);
2356 		if (rc)
2357 			return rc;
2358 
2359 		/*
2360 		 * Fallback to old SID on NNP or nosuid if not an allowed
2361 		 * transition.
2362 		 */
2363 		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2364 		if (rc)
2365 			new_tsec->sid = old_tsec->sid;
2366 	}
2367 
2368 	ad.type = LSM_AUDIT_DATA_FILE;
2369 	ad.u.file = bprm->file;
2370 
2371 	if (new_tsec->sid == old_tsec->sid) {
2372 		rc = avc_has_perm(old_tsec->sid, isec->sid,
2373 				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2374 		if (rc)
2375 			return rc;
2376 	} else {
2377 		/* Check permissions for the transition. */
2378 		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2379 				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2380 		if (rc)
2381 			return rc;
2382 
2383 		rc = avc_has_perm(new_tsec->sid, isec->sid,
2384 				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2385 		if (rc)
2386 			return rc;
2387 
2388 		/* Check for shared state */
2389 		if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2390 			rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2391 					  SECCLASS_PROCESS, PROCESS__SHARE,
2392 					  NULL);
2393 			if (rc)
2394 				return -EPERM;
2395 		}
2396 
2397 		/* Make sure that anyone attempting to ptrace over a task that
2398 		 * changes its SID has the appropriate permit */
2399 		if (bprm->unsafe &
2400 		    (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2401 			u32 ptsid = ptrace_parent_sid(current);
2402 			if (ptsid != 0) {
2403 				rc = avc_has_perm(ptsid, new_tsec->sid,
2404 						  SECCLASS_PROCESS,
2405 						  PROCESS__PTRACE, NULL);
2406 				if (rc)
2407 					return -EPERM;
2408 			}
2409 		}
2410 
2411 		/* Clear any possibly unsafe personality bits on exec: */
2412 		bprm->per_clear |= PER_CLEAR_ON_SETID;
2413 	}
2414 
2415 	return 0;
2416 }
2417 
2418 static int selinux_bprm_secureexec(struct linux_binprm *bprm)
2419 {
2420 	const struct task_security_struct *tsec = current_security();
2421 	u32 sid, osid;
2422 	int atsecure = 0;
2423 
2424 	sid = tsec->sid;
2425 	osid = tsec->osid;
2426 
2427 	if (osid != sid) {
2428 		/* Enable secure mode for SIDs transitions unless
2429 		   the noatsecure permission is granted between
2430 		   the two SIDs, i.e. ahp returns 0. */
2431 		atsecure = avc_has_perm(osid, sid,
2432 					SECCLASS_PROCESS,
2433 					PROCESS__NOATSECURE, NULL);
2434 	}
2435 
2436 	return !!atsecure;
2437 }
2438 
2439 static int match_file(const void *p, struct file *file, unsigned fd)
2440 {
2441 	return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
2442 }
2443 
2444 /* Derived from fs/exec.c:flush_old_files. */
2445 static inline void flush_unauthorized_files(const struct cred *cred,
2446 					    struct files_struct *files)
2447 {
2448 	struct file *file, *devnull = NULL;
2449 	struct tty_struct *tty;
2450 	int drop_tty = 0;
2451 	unsigned n;
2452 
2453 	tty = get_current_tty();
2454 	if (tty) {
2455 		spin_lock(&tty->files_lock);
2456 		if (!list_empty(&tty->tty_files)) {
2457 			struct tty_file_private *file_priv;
2458 
2459 			/* Revalidate access to controlling tty.
2460 			   Use file_path_has_perm on the tty path directly
2461 			   rather than using file_has_perm, as this particular
2462 			   open file may belong to another process and we are
2463 			   only interested in the inode-based check here. */
2464 			file_priv = list_first_entry(&tty->tty_files,
2465 						struct tty_file_private, list);
2466 			file = file_priv->file;
2467 			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2468 				drop_tty = 1;
2469 		}
2470 		spin_unlock(&tty->files_lock);
2471 		tty_kref_put(tty);
2472 	}
2473 	/* Reset controlling tty. */
2474 	if (drop_tty)
2475 		no_tty();
2476 
2477 	/* Revalidate access to inherited open files. */
2478 	n = iterate_fd(files, 0, match_file, cred);
2479 	if (!n) /* none found? */
2480 		return;
2481 
2482 	devnull = dentry_open(&selinux_null, O_RDWR, cred);
2483 	if (IS_ERR(devnull))
2484 		devnull = NULL;
2485 	/* replace all the matching ones with this */
2486 	do {
2487 		replace_fd(n - 1, devnull, 0);
2488 	} while ((n = iterate_fd(files, n, match_file, cred)) != 0);
2489 	if (devnull)
2490 		fput(devnull);
2491 }
2492 
2493 /*
2494  * Prepare a process for imminent new credential changes due to exec
2495  */
2496 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2497 {
2498 	struct task_security_struct *new_tsec;
2499 	struct rlimit *rlim, *initrlim;
2500 	int rc, i;
2501 
2502 	new_tsec = bprm->cred->security;
2503 	if (new_tsec->sid == new_tsec->osid)
2504 		return;
2505 
2506 	/* Close files for which the new task SID is not authorized. */
2507 	flush_unauthorized_files(bprm->cred, current->files);
2508 
2509 	/* Always clear parent death signal on SID transitions. */
2510 	current->pdeath_signal = 0;
2511 
2512 	/* Check whether the new SID can inherit resource limits from the old
2513 	 * SID.  If not, reset all soft limits to the lower of the current
2514 	 * task's hard limit and the init task's soft limit.
2515 	 *
2516 	 * Note that the setting of hard limits (even to lower them) can be
2517 	 * controlled by the setrlimit check.  The inclusion of the init task's
2518 	 * soft limit into the computation is to avoid resetting soft limits
2519 	 * higher than the default soft limit for cases where the default is
2520 	 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2521 	 */
2522 	rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2523 			  PROCESS__RLIMITINH, NULL);
2524 	if (rc) {
2525 		/* protect against do_prlimit() */
2526 		task_lock(current);
2527 		for (i = 0; i < RLIM_NLIMITS; i++) {
2528 			rlim = current->signal->rlim + i;
2529 			initrlim = init_task.signal->rlim + i;
2530 			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2531 		}
2532 		task_unlock(current);
2533 		update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2534 	}
2535 }
2536 
2537 /*
2538  * Clean up the process immediately after the installation of new credentials
2539  * due to exec
2540  */
2541 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2542 {
2543 	const struct task_security_struct *tsec = current_security();
2544 	struct itimerval itimer;
2545 	u32 osid, sid;
2546 	int rc, i;
2547 
2548 	osid = tsec->osid;
2549 	sid = tsec->sid;
2550 
2551 	if (sid == osid)
2552 		return;
2553 
2554 	/* Check whether the new SID can inherit signal state from the old SID.
2555 	 * If not, clear itimers to avoid subsequent signal generation and
2556 	 * flush and unblock signals.
2557 	 *
2558 	 * This must occur _after_ the task SID has been updated so that any
2559 	 * kill done after the flush will be checked against the new SID.
2560 	 */
2561 	rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2562 	if (rc) {
2563 		memset(&itimer, 0, sizeof itimer);
2564 		for (i = 0; i < 3; i++)
2565 			do_setitimer(i, &itimer, NULL);
2566 		spin_lock_irq(&current->sighand->siglock);
2567 		if (!fatal_signal_pending(current)) {
2568 			flush_sigqueue(&current->pending);
2569 			flush_sigqueue(&current->signal->shared_pending);
2570 			flush_signal_handlers(current, 1);
2571 			sigemptyset(&current->blocked);
2572 			recalc_sigpending();
2573 		}
2574 		spin_unlock_irq(&current->sighand->siglock);
2575 	}
2576 
2577 	/* Wake up the parent if it is waiting so that it can recheck
2578 	 * wait permission to the new task SID. */
2579 	read_lock(&tasklist_lock);
2580 	__wake_up_parent(current, current->real_parent);
2581 	read_unlock(&tasklist_lock);
2582 }
2583 
2584 /* superblock security operations */
2585 
2586 static int selinux_sb_alloc_security(struct super_block *sb)
2587 {
2588 	return superblock_alloc_security(sb);
2589 }
2590 
2591 static void selinux_sb_free_security(struct super_block *sb)
2592 {
2593 	superblock_free_security(sb);
2594 }
2595 
2596 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2597 {
2598 	if (plen > olen)
2599 		return 0;
2600 
2601 	return !memcmp(prefix, option, plen);
2602 }
2603 
2604 static inline int selinux_option(char *option, int len)
2605 {
2606 	return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2607 		match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2608 		match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2609 		match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2610 		match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
2611 }
2612 
2613 static inline void take_option(char **to, char *from, int *first, int len)
2614 {
2615 	if (!*first) {
2616 		**to = ',';
2617 		*to += 1;
2618 	} else
2619 		*first = 0;
2620 	memcpy(*to, from, len);
2621 	*to += len;
2622 }
2623 
2624 static inline void take_selinux_option(char **to, char *from, int *first,
2625 				       int len)
2626 {
2627 	int current_size = 0;
2628 
2629 	if (!*first) {
2630 		**to = '|';
2631 		*to += 1;
2632 	} else
2633 		*first = 0;
2634 
2635 	while (current_size < len) {
2636 		if (*from != '"') {
2637 			**to = *from;
2638 			*to += 1;
2639 		}
2640 		from += 1;
2641 		current_size += 1;
2642 	}
2643 }
2644 
2645 static int selinux_sb_copy_data(char *orig, char *copy)
2646 {
2647 	int fnosec, fsec, rc = 0;
2648 	char *in_save, *in_curr, *in_end;
2649 	char *sec_curr, *nosec_save, *nosec;
2650 	int open_quote = 0;
2651 
2652 	in_curr = orig;
2653 	sec_curr = copy;
2654 
2655 	nosec = (char *)get_zeroed_page(GFP_KERNEL);
2656 	if (!nosec) {
2657 		rc = -ENOMEM;
2658 		goto out;
2659 	}
2660 
2661 	nosec_save = nosec;
2662 	fnosec = fsec = 1;
2663 	in_save = in_end = orig;
2664 
2665 	do {
2666 		if (*in_end == '"')
2667 			open_quote = !open_quote;
2668 		if ((*in_end == ',' && open_quote == 0) ||
2669 				*in_end == '\0') {
2670 			int len = in_end - in_curr;
2671 
2672 			if (selinux_option(in_curr, len))
2673 				take_selinux_option(&sec_curr, in_curr, &fsec, len);
2674 			else
2675 				take_option(&nosec, in_curr, &fnosec, len);
2676 
2677 			in_curr = in_end + 1;
2678 		}
2679 	} while (*in_end++);
2680 
2681 	strcpy(in_save, nosec_save);
2682 	free_page((unsigned long)nosec_save);
2683 out:
2684 	return rc;
2685 }
2686 
2687 static int selinux_sb_remount(struct super_block *sb, void *data)
2688 {
2689 	int rc, i, *flags;
2690 	struct security_mnt_opts opts;
2691 	char *secdata, **mount_options;
2692 	struct superblock_security_struct *sbsec = sb->s_security;
2693 
2694 	if (!(sbsec->flags & SE_SBINITIALIZED))
2695 		return 0;
2696 
2697 	if (!data)
2698 		return 0;
2699 
2700 	if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
2701 		return 0;
2702 
2703 	security_init_mnt_opts(&opts);
2704 	secdata = alloc_secdata();
2705 	if (!secdata)
2706 		return -ENOMEM;
2707 	rc = selinux_sb_copy_data(data, secdata);
2708 	if (rc)
2709 		goto out_free_secdata;
2710 
2711 	rc = selinux_parse_opts_str(secdata, &opts);
2712 	if (rc)
2713 		goto out_free_secdata;
2714 
2715 	mount_options = opts.mnt_opts;
2716 	flags = opts.mnt_opts_flags;
2717 
2718 	for (i = 0; i < opts.num_mnt_opts; i++) {
2719 		u32 sid;
2720 
2721 		if (flags[i] == SBLABEL_MNT)
2722 			continue;
2723 		rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL);
2724 		if (rc) {
2725 			printk(KERN_WARNING "SELinux: security_context_str_to_sid"
2726 			       "(%s) failed for (dev %s, type %s) errno=%d\n",
2727 			       mount_options[i], sb->s_id, sb->s_type->name, rc);
2728 			goto out_free_opts;
2729 		}
2730 		rc = -EINVAL;
2731 		switch (flags[i]) {
2732 		case FSCONTEXT_MNT:
2733 			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
2734 				goto out_bad_option;
2735 			break;
2736 		case CONTEXT_MNT:
2737 			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
2738 				goto out_bad_option;
2739 			break;
2740 		case ROOTCONTEXT_MNT: {
2741 			struct inode_security_struct *root_isec;
2742 			root_isec = backing_inode_security(sb->s_root);
2743 
2744 			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
2745 				goto out_bad_option;
2746 			break;
2747 		}
2748 		case DEFCONTEXT_MNT:
2749 			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
2750 				goto out_bad_option;
2751 			break;
2752 		default:
2753 			goto out_free_opts;
2754 		}
2755 	}
2756 
2757 	rc = 0;
2758 out_free_opts:
2759 	security_free_mnt_opts(&opts);
2760 out_free_secdata:
2761 	free_secdata(secdata);
2762 	return rc;
2763 out_bad_option:
2764 	printk(KERN_WARNING "SELinux: unable to change security options "
2765 	       "during remount (dev %s, type=%s)\n", sb->s_id,
2766 	       sb->s_type->name);
2767 	goto out_free_opts;
2768 }
2769 
2770 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
2771 {
2772 	const struct cred *cred = current_cred();
2773 	struct common_audit_data ad;
2774 	int rc;
2775 
2776 	rc = superblock_doinit(sb, data);
2777 	if (rc)
2778 		return rc;
2779 
2780 	/* Allow all mounts performed by the kernel */
2781 	if (flags & MS_KERNMOUNT)
2782 		return 0;
2783 
2784 	ad.type = LSM_AUDIT_DATA_DENTRY;
2785 	ad.u.dentry = sb->s_root;
2786 	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2787 }
2788 
2789 static int selinux_sb_statfs(struct dentry *dentry)
2790 {
2791 	const struct cred *cred = current_cred();
2792 	struct common_audit_data ad;
2793 
2794 	ad.type = LSM_AUDIT_DATA_DENTRY;
2795 	ad.u.dentry = dentry->d_sb->s_root;
2796 	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2797 }
2798 
2799 static int selinux_mount(const char *dev_name,
2800 			 const struct path *path,
2801 			 const char *type,
2802 			 unsigned long flags,
2803 			 void *data)
2804 {
2805 	const struct cred *cred = current_cred();
2806 
2807 	if (flags & MS_REMOUNT)
2808 		return superblock_has_perm(cred, path->dentry->d_sb,
2809 					   FILESYSTEM__REMOUNT, NULL);
2810 	else
2811 		return path_has_perm(cred, path, FILE__MOUNTON);
2812 }
2813 
2814 static int selinux_umount(struct vfsmount *mnt, int flags)
2815 {
2816 	const struct cred *cred = current_cred();
2817 
2818 	return superblock_has_perm(cred, mnt->mnt_sb,
2819 				   FILESYSTEM__UNMOUNT, NULL);
2820 }
2821 
2822 /* inode security operations */
2823 
2824 static int selinux_inode_alloc_security(struct inode *inode)
2825 {
2826 	return inode_alloc_security(inode);
2827 }
2828 
2829 static void selinux_inode_free_security(struct inode *inode)
2830 {
2831 	inode_free_security(inode);
2832 }
2833 
2834 static int selinux_dentry_init_security(struct dentry *dentry, int mode,
2835 					const struct qstr *name, void **ctx,
2836 					u32 *ctxlen)
2837 {
2838 	u32 newsid;
2839 	int rc;
2840 
2841 	rc = selinux_determine_inode_label(current_security(),
2842 					   d_inode(dentry->d_parent), name,
2843 					   inode_mode_to_security_class(mode),
2844 					   &newsid);
2845 	if (rc)
2846 		return rc;
2847 
2848 	return security_sid_to_context(newsid, (char **)ctx, ctxlen);
2849 }
2850 
2851 static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
2852 					  struct qstr *name,
2853 					  const struct cred *old,
2854 					  struct cred *new)
2855 {
2856 	u32 newsid;
2857 	int rc;
2858 	struct task_security_struct *tsec;
2859 
2860 	rc = selinux_determine_inode_label(old->security,
2861 					   d_inode(dentry->d_parent), name,
2862 					   inode_mode_to_security_class(mode),
2863 					   &newsid);
2864 	if (rc)
2865 		return rc;
2866 
2867 	tsec = new->security;
2868 	tsec->create_sid = newsid;
2869 	return 0;
2870 }
2871 
2872 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2873 				       const struct qstr *qstr,
2874 				       const char **name,
2875 				       void **value, size_t *len)
2876 {
2877 	const struct task_security_struct *tsec = current_security();
2878 	struct superblock_security_struct *sbsec;
2879 	u32 sid, newsid, clen;
2880 	int rc;
2881 	char *context;
2882 
2883 	sbsec = dir->i_sb->s_security;
2884 
2885 	sid = tsec->sid;
2886 	newsid = tsec->create_sid;
2887 
2888 	rc = selinux_determine_inode_label(current_security(),
2889 		dir, qstr,
2890 		inode_mode_to_security_class(inode->i_mode),
2891 		&newsid);
2892 	if (rc)
2893 		return rc;
2894 
2895 	/* Possibly defer initialization to selinux_complete_init. */
2896 	if (sbsec->flags & SE_SBINITIALIZED) {
2897 		struct inode_security_struct *isec = inode->i_security;
2898 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
2899 		isec->sid = newsid;
2900 		isec->initialized = LABEL_INITIALIZED;
2901 	}
2902 
2903 	if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT))
2904 		return -EOPNOTSUPP;
2905 
2906 	if (name)
2907 		*name = XATTR_SELINUX_SUFFIX;
2908 
2909 	if (value && len) {
2910 		rc = security_sid_to_context_force(newsid, &context, &clen);
2911 		if (rc)
2912 			return rc;
2913 		*value = context;
2914 		*len = clen;
2915 	}
2916 
2917 	return 0;
2918 }
2919 
2920 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
2921 {
2922 	return may_create(dir, dentry, SECCLASS_FILE);
2923 }
2924 
2925 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2926 {
2927 	return may_link(dir, old_dentry, MAY_LINK);
2928 }
2929 
2930 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2931 {
2932 	return may_link(dir, dentry, MAY_UNLINK);
2933 }
2934 
2935 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2936 {
2937 	return may_create(dir, dentry, SECCLASS_LNK_FILE);
2938 }
2939 
2940 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
2941 {
2942 	return may_create(dir, dentry, SECCLASS_DIR);
2943 }
2944 
2945 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2946 {
2947 	return may_link(dir, dentry, MAY_RMDIR);
2948 }
2949 
2950 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
2951 {
2952 	return may_create(dir, dentry, inode_mode_to_security_class(mode));
2953 }
2954 
2955 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2956 				struct inode *new_inode, struct dentry *new_dentry)
2957 {
2958 	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2959 }
2960 
2961 static int selinux_inode_readlink(struct dentry *dentry)
2962 {
2963 	const struct cred *cred = current_cred();
2964 
2965 	return dentry_has_perm(cred, dentry, FILE__READ);
2966 }
2967 
2968 static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
2969 				     bool rcu)
2970 {
2971 	const struct cred *cred = current_cred();
2972 	struct common_audit_data ad;
2973 	struct inode_security_struct *isec;
2974 	u32 sid;
2975 
2976 	validate_creds(cred);
2977 
2978 	ad.type = LSM_AUDIT_DATA_DENTRY;
2979 	ad.u.dentry = dentry;
2980 	sid = cred_sid(cred);
2981 	isec = inode_security_rcu(inode, rcu);
2982 	if (IS_ERR(isec))
2983 		return PTR_ERR(isec);
2984 
2985 	return avc_has_perm_flags(sid, isec->sid, isec->sclass, FILE__READ, &ad,
2986 				  rcu ? MAY_NOT_BLOCK : 0);
2987 }
2988 
2989 static noinline int audit_inode_permission(struct inode *inode,
2990 					   u32 perms, u32 audited, u32 denied,
2991 					   int result,
2992 					   unsigned flags)
2993 {
2994 	struct common_audit_data ad;
2995 	struct inode_security_struct *isec = inode->i_security;
2996 	int rc;
2997 
2998 	ad.type = LSM_AUDIT_DATA_INODE;
2999 	ad.u.inode = inode;
3000 
3001 	rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
3002 			    audited, denied, result, &ad, flags);
3003 	if (rc)
3004 		return rc;
3005 	return 0;
3006 }
3007 
3008 static int selinux_inode_permission(struct inode *inode, int mask)
3009 {
3010 	const struct cred *cred = current_cred();
3011 	u32 perms;
3012 	bool from_access;
3013 	unsigned flags = mask & MAY_NOT_BLOCK;
3014 	struct inode_security_struct *isec;
3015 	u32 sid;
3016 	struct av_decision avd;
3017 	int rc, rc2;
3018 	u32 audited, denied;
3019 
3020 	from_access = mask & MAY_ACCESS;
3021 	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
3022 
3023 	/* No permission to check.  Existence test. */
3024 	if (!mask)
3025 		return 0;
3026 
3027 	validate_creds(cred);
3028 
3029 	if (unlikely(IS_PRIVATE(inode)))
3030 		return 0;
3031 
3032 	perms = file_mask_to_av(inode->i_mode, mask);
3033 
3034 	sid = cred_sid(cred);
3035 	isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK);
3036 	if (IS_ERR(isec))
3037 		return PTR_ERR(isec);
3038 
3039 	rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);
3040 	audited = avc_audit_required(perms, &avd, rc,
3041 				     from_access ? FILE__AUDIT_ACCESS : 0,
3042 				     &denied);
3043 	if (likely(!audited))
3044 		return rc;
3045 
3046 	rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags);
3047 	if (rc2)
3048 		return rc2;
3049 	return rc;
3050 }
3051 
3052 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
3053 {
3054 	const struct cred *cred = current_cred();
3055 	unsigned int ia_valid = iattr->ia_valid;
3056 	__u32 av = FILE__WRITE;
3057 
3058 	/* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
3059 	if (ia_valid & ATTR_FORCE) {
3060 		ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
3061 			      ATTR_FORCE);
3062 		if (!ia_valid)
3063 			return 0;
3064 	}
3065 
3066 	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
3067 			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
3068 		return dentry_has_perm(cred, dentry, FILE__SETATTR);
3069 
3070 	if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE)
3071 			&& !(ia_valid & ATTR_FILE))
3072 		av |= FILE__OPEN;
3073 
3074 	return dentry_has_perm(cred, dentry, av);
3075 }
3076 
3077 static int selinux_inode_getattr(const struct path *path)
3078 {
3079 	return path_has_perm(current_cred(), path, FILE__GETATTR);
3080 }
3081 
3082 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
3083 {
3084 	const struct cred *cred = current_cred();
3085 
3086 	if (!strncmp(name, XATTR_SECURITY_PREFIX,
3087 		     sizeof XATTR_SECURITY_PREFIX - 1)) {
3088 		if (!strcmp(name, XATTR_NAME_CAPS)) {
3089 			if (!capable(CAP_SETFCAP))
3090 				return -EPERM;
3091 		} else if (!capable(CAP_SYS_ADMIN)) {
3092 			/* A different attribute in the security namespace.
3093 			   Restrict to administrator. */
3094 			return -EPERM;
3095 		}
3096 	}
3097 
3098 	/* Not an attribute we recognize, so just check the
3099 	   ordinary setattr permission. */
3100 	return dentry_has_perm(cred, dentry, FILE__SETATTR);
3101 }
3102 
3103 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
3104 				  const void *value, size_t size, int flags)
3105 {
3106 	struct inode *inode = d_backing_inode(dentry);
3107 	struct inode_security_struct *isec;
3108 	struct superblock_security_struct *sbsec;
3109 	struct common_audit_data ad;
3110 	u32 newsid, sid = current_sid();
3111 	int rc = 0;
3112 
3113 	if (strcmp(name, XATTR_NAME_SELINUX))
3114 		return selinux_inode_setotherxattr(dentry, name);
3115 
3116 	sbsec = inode->i_sb->s_security;
3117 	if (!(sbsec->flags & SBLABEL_MNT))
3118 		return -EOPNOTSUPP;
3119 
3120 	if (!inode_owner_or_capable(inode))
3121 		return -EPERM;
3122 
3123 	ad.type = LSM_AUDIT_DATA_DENTRY;
3124 	ad.u.dentry = dentry;
3125 
3126 	isec = backing_inode_security(dentry);
3127 	rc = avc_has_perm(sid, isec->sid, isec->sclass,
3128 			  FILE__RELABELFROM, &ad);
3129 	if (rc)
3130 		return rc;
3131 
3132 	rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
3133 	if (rc == -EINVAL) {
3134 		if (!capable(CAP_MAC_ADMIN)) {
3135 			struct audit_buffer *ab;
3136 			size_t audit_size;
3137 			const char *str;
3138 
3139 			/* We strip a nul only if it is at the end, otherwise the
3140 			 * context contains a nul and we should audit that */
3141 			if (value) {
3142 				str = value;
3143 				if (str[size - 1] == '\0')
3144 					audit_size = size - 1;
3145 				else
3146 					audit_size = size;
3147 			} else {
3148 				str = "";
3149 				audit_size = 0;
3150 			}
3151 			ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
3152 			audit_log_format(ab, "op=setxattr invalid_context=");
3153 			audit_log_n_untrustedstring(ab, value, audit_size);
3154 			audit_log_end(ab);
3155 
3156 			return rc;
3157 		}
3158 		rc = security_context_to_sid_force(value, size, &newsid);
3159 	}
3160 	if (rc)
3161 		return rc;
3162 
3163 	rc = avc_has_perm(sid, newsid, isec->sclass,
3164 			  FILE__RELABELTO, &ad);
3165 	if (rc)
3166 		return rc;
3167 
3168 	rc = security_validate_transition(isec->sid, newsid, sid,
3169 					  isec->sclass);
3170 	if (rc)
3171 		return rc;
3172 
3173 	return avc_has_perm(newsid,
3174 			    sbsec->sid,
3175 			    SECCLASS_FILESYSTEM,
3176 			    FILESYSTEM__ASSOCIATE,
3177 			    &ad);
3178 }
3179 
3180 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3181 					const void *value, size_t size,
3182 					int flags)
3183 {
3184 	struct inode *inode = d_backing_inode(dentry);
3185 	struct inode_security_struct *isec;
3186 	u32 newsid;
3187 	int rc;
3188 
3189 	if (strcmp(name, XATTR_NAME_SELINUX)) {
3190 		/* Not an attribute we recognize, so nothing to do. */
3191 		return;
3192 	}
3193 
3194 	rc = security_context_to_sid_force(value, size, &newsid);
3195 	if (rc) {
3196 		printk(KERN_ERR "SELinux:  unable to map context to SID"
3197 		       "for (%s, %lu), rc=%d\n",
3198 		       inode->i_sb->s_id, inode->i_ino, -rc);
3199 		return;
3200 	}
3201 
3202 	isec = backing_inode_security(dentry);
3203 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
3204 	isec->sid = newsid;
3205 	isec->initialized = LABEL_INITIALIZED;
3206 
3207 	return;
3208 }
3209 
3210 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
3211 {
3212 	const struct cred *cred = current_cred();
3213 
3214 	return dentry_has_perm(cred, dentry, FILE__GETATTR);
3215 }
3216 
3217 static int selinux_inode_listxattr(struct dentry *dentry)
3218 {
3219 	const struct cred *cred = current_cred();
3220 
3221 	return dentry_has_perm(cred, dentry, FILE__GETATTR);
3222 }
3223 
3224 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
3225 {
3226 	if (strcmp(name, XATTR_NAME_SELINUX))
3227 		return selinux_inode_setotherxattr(dentry, name);
3228 
3229 	/* No one is allowed to remove a SELinux security label.
3230 	   You can change the label, but all data must be labeled. */
3231 	return -EACCES;
3232 }
3233 
3234 /*
3235  * Copy the inode security context value to the user.
3236  *
3237  * Permission check is handled by selinux_inode_getxattr hook.
3238  */
3239 static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc)
3240 {
3241 	u32 size;
3242 	int error;
3243 	char *context = NULL;
3244 	struct inode_security_struct *isec;
3245 
3246 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
3247 		return -EOPNOTSUPP;
3248 
3249 	/*
3250 	 * If the caller has CAP_MAC_ADMIN, then get the raw context
3251 	 * value even if it is not defined by current policy; otherwise,
3252 	 * use the in-core value under current policy.
3253 	 * Use the non-auditing forms of the permission checks since
3254 	 * getxattr may be called by unprivileged processes commonly
3255 	 * and lack of permission just means that we fall back to the
3256 	 * in-core context value, not a denial.
3257 	 */
3258 	error = cap_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
3259 			    SECURITY_CAP_NOAUDIT);
3260 	if (!error)
3261 		error = cred_has_capability(current_cred(), CAP_MAC_ADMIN,
3262 					    SECURITY_CAP_NOAUDIT, true);
3263 	isec = inode_security(inode);
3264 	if (!error)
3265 		error = security_sid_to_context_force(isec->sid, &context,
3266 						      &size);
3267 	else
3268 		error = security_sid_to_context(isec->sid, &context, &size);
3269 	if (error)
3270 		return error;
3271 	error = size;
3272 	if (alloc) {
3273 		*buffer = context;
3274 		goto out_nofree;
3275 	}
3276 	kfree(context);
3277 out_nofree:
3278 	return error;
3279 }
3280 
3281 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3282 				     const void *value, size_t size, int flags)
3283 {
3284 	struct inode_security_struct *isec = inode_security_novalidate(inode);
3285 	u32 newsid;
3286 	int rc;
3287 
3288 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
3289 		return -EOPNOTSUPP;
3290 
3291 	if (!value || !size)
3292 		return -EACCES;
3293 
3294 	rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
3295 	if (rc)
3296 		return rc;
3297 
3298 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
3299 	isec->sid = newsid;
3300 	isec->initialized = LABEL_INITIALIZED;
3301 	return 0;
3302 }
3303 
3304 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
3305 {
3306 	const int len = sizeof(XATTR_NAME_SELINUX);
3307 	if (buffer && len <= buffer_size)
3308 		memcpy(buffer, XATTR_NAME_SELINUX, len);
3309 	return len;
3310 }
3311 
3312 static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
3313 {
3314 	struct inode_security_struct *isec = inode_security_novalidate(inode);
3315 	*secid = isec->sid;
3316 }
3317 
3318 static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
3319 {
3320 	u32 sid;
3321 	struct task_security_struct *tsec;
3322 	struct cred *new_creds = *new;
3323 
3324 	if (new_creds == NULL) {
3325 		new_creds = prepare_creds();
3326 		if (!new_creds)
3327 			return -ENOMEM;
3328 	}
3329 
3330 	tsec = new_creds->security;
3331 	/* Get label from overlay inode and set it in create_sid */
3332 	selinux_inode_getsecid(d_inode(src), &sid);
3333 	tsec->create_sid = sid;
3334 	*new = new_creds;
3335 	return 0;
3336 }
3337 
3338 static int selinux_inode_copy_up_xattr(const char *name)
3339 {
3340 	/* The copy_up hook above sets the initial context on an inode, but we
3341 	 * don't then want to overwrite it by blindly copying all the lower
3342 	 * xattrs up.  Instead, we have to filter out SELinux-related xattrs.
3343 	 */
3344 	if (strcmp(name, XATTR_NAME_SELINUX) == 0)
3345 		return 1; /* Discard */
3346 	/*
3347 	 * Any other attribute apart from SELINUX is not claimed, supported
3348 	 * by selinux.
3349 	 */
3350 	return -EOPNOTSUPP;
3351 }
3352 
3353 /* file security operations */
3354 
3355 static int selinux_revalidate_file_permission(struct file *file, int mask)
3356 {
3357 	const struct cred *cred = current_cred();
3358 	struct inode *inode = file_inode(file);
3359 
3360 	/* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
3361 	if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
3362 		mask |= MAY_APPEND;
3363 
3364 	return file_has_perm(cred, file,
3365 			     file_mask_to_av(inode->i_mode, mask));
3366 }
3367 
3368 static int selinux_file_permission(struct file *file, int mask)
3369 {
3370 	struct inode *inode = file_inode(file);
3371 	struct file_security_struct *fsec = file->f_security;
3372 	struct inode_security_struct *isec;
3373 	u32 sid = current_sid();
3374 
3375 	if (!mask)
3376 		/* No permission to check.  Existence test. */
3377 		return 0;
3378 
3379 	isec = inode_security(inode);
3380 	if (sid == fsec->sid && fsec->isid == isec->sid &&
3381 	    fsec->pseqno == avc_policy_seqno())
3382 		/* No change since file_open check. */
3383 		return 0;
3384 
3385 	return selinux_revalidate_file_permission(file, mask);
3386 }
3387 
3388 static int selinux_file_alloc_security(struct file *file)
3389 {
3390 	return file_alloc_security(file);
3391 }
3392 
3393 static void selinux_file_free_security(struct file *file)
3394 {
3395 	file_free_security(file);
3396 }
3397 
3398 /*
3399  * Check whether a task has the ioctl permission and cmd
3400  * operation to an inode.
3401  */
3402 static int ioctl_has_perm(const struct cred *cred, struct file *file,
3403 		u32 requested, u16 cmd)
3404 {
3405 	struct common_audit_data ad;
3406 	struct file_security_struct *fsec = file->f_security;
3407 	struct inode *inode = file_inode(file);
3408 	struct inode_security_struct *isec;
3409 	struct lsm_ioctlop_audit ioctl;
3410 	u32 ssid = cred_sid(cred);
3411 	int rc;
3412 	u8 driver = cmd >> 8;
3413 	u8 xperm = cmd & 0xff;
3414 
3415 	ad.type = LSM_AUDIT_DATA_IOCTL_OP;
3416 	ad.u.op = &ioctl;
3417 	ad.u.op->cmd = cmd;
3418 	ad.u.op->path = file->f_path;
3419 
3420 	if (ssid != fsec->sid) {
3421 		rc = avc_has_perm(ssid, fsec->sid,
3422 				SECCLASS_FD,
3423 				FD__USE,
3424 				&ad);
3425 		if (rc)
3426 			goto out;
3427 	}
3428 
3429 	if (unlikely(IS_PRIVATE(inode)))
3430 		return 0;
3431 
3432 	isec = inode_security(inode);
3433 	rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass,
3434 			requested, driver, xperm, &ad);
3435 out:
3436 	return rc;
3437 }
3438 
3439 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3440 			      unsigned long arg)
3441 {
3442 	const struct cred *cred = current_cred();
3443 	int error = 0;
3444 
3445 	switch (cmd) {
3446 	case FIONREAD:
3447 	/* fall through */
3448 	case FIBMAP:
3449 	/* fall through */
3450 	case FIGETBSZ:
3451 	/* fall through */
3452 	case FS_IOC_GETFLAGS:
3453 	/* fall through */
3454 	case FS_IOC_GETVERSION:
3455 		error = file_has_perm(cred, file, FILE__GETATTR);
3456 		break;
3457 
3458 	case FS_IOC_SETFLAGS:
3459 	/* fall through */
3460 	case FS_IOC_SETVERSION:
3461 		error = file_has_perm(cred, file, FILE__SETATTR);
3462 		break;
3463 
3464 	/* sys_ioctl() checks */
3465 	case FIONBIO:
3466 	/* fall through */
3467 	case FIOASYNC:
3468 		error = file_has_perm(cred, file, 0);
3469 		break;
3470 
3471 	case KDSKBENT:
3472 	case KDSKBSENT:
3473 		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3474 					    SECURITY_CAP_AUDIT, true);
3475 		break;
3476 
3477 	/* default case assumes that the command will go
3478 	 * to the file's ioctl() function.
3479 	 */
3480 	default:
3481 		error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3482 	}
3483 	return error;
3484 }
3485 
3486 static int default_noexec;
3487 
3488 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3489 {
3490 	const struct cred *cred = current_cred();
3491 	int rc = 0;
3492 
3493 	if (default_noexec &&
3494 	    (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) ||
3495 				   (!shared && (prot & PROT_WRITE)))) {
3496 		/*
3497 		 * We are making executable an anonymous mapping or a
3498 		 * private file mapping that will also be writable.
3499 		 * This has an additional check.
3500 		 */
3501 		rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
3502 		if (rc)
3503 			goto error;
3504 	}
3505 
3506 	if (file) {
3507 		/* read access is always possible with a mapping */
3508 		u32 av = FILE__READ;
3509 
3510 		/* write access only matters if the mapping is shared */
3511 		if (shared && (prot & PROT_WRITE))
3512 			av |= FILE__WRITE;
3513 
3514 		if (prot & PROT_EXEC)
3515 			av |= FILE__EXECUTE;
3516 
3517 		return file_has_perm(cred, file, av);
3518 	}
3519 
3520 error:
3521 	return rc;
3522 }
3523 
3524 static int selinux_mmap_addr(unsigned long addr)
3525 {
3526 	int rc = 0;
3527 
3528 	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3529 		u32 sid = current_sid();
3530 		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3531 				  MEMPROTECT__MMAP_ZERO, NULL);
3532 	}
3533 
3534 	return rc;
3535 }
3536 
3537 static int selinux_mmap_file(struct file *file, unsigned long reqprot,
3538 			     unsigned long prot, unsigned long flags)
3539 {
3540 	if (selinux_checkreqprot)
3541 		prot = reqprot;
3542 
3543 	return file_map_prot_check(file, prot,
3544 				   (flags & MAP_TYPE) == MAP_SHARED);
3545 }
3546 
3547 static int selinux_file_mprotect(struct vm_area_struct *vma,
3548 				 unsigned long reqprot,
3549 				 unsigned long prot)
3550 {
3551 	const struct cred *cred = current_cred();
3552 
3553 	if (selinux_checkreqprot)
3554 		prot = reqprot;
3555 
3556 	if (default_noexec &&
3557 	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3558 		int rc = 0;
3559 		if (vma->vm_start >= vma->vm_mm->start_brk &&
3560 		    vma->vm_end <= vma->vm_mm->brk) {
3561 			rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3562 		} else if (!vma->vm_file &&
3563 			   ((vma->vm_start <= vma->vm_mm->start_stack &&
3564 			     vma->vm_end >= vma->vm_mm->start_stack) ||
3565 			    vma_is_stack_for_task(vma, current))) {
3566 			rc = current_has_perm(current, PROCESS__EXECSTACK);
3567 		} else if (vma->vm_file && vma->anon_vma) {
3568 			/*
3569 			 * We are making executable a file mapping that has
3570 			 * had some COW done. Since pages might have been
3571 			 * written, check ability to execute the possibly
3572 			 * modified content.  This typically should only
3573 			 * occur for text relocations.
3574 			 */
3575 			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3576 		}
3577 		if (rc)
3578 			return rc;
3579 	}
3580 
3581 	return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3582 }
3583 
3584 static int selinux_file_lock(struct file *file, unsigned int cmd)
3585 {
3586 	const struct cred *cred = current_cred();
3587 
3588 	return file_has_perm(cred, file, FILE__LOCK);
3589 }
3590 
3591 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3592 			      unsigned long arg)
3593 {
3594 	const struct cred *cred = current_cred();
3595 	int err = 0;
3596 
3597 	switch (cmd) {
3598 	case F_SETFL:
3599 		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3600 			err = file_has_perm(cred, file, FILE__WRITE);
3601 			break;
3602 		}
3603 		/* fall through */
3604 	case F_SETOWN:
3605 	case F_SETSIG:
3606 	case F_GETFL:
3607 	case F_GETOWN:
3608 	case F_GETSIG:
3609 	case F_GETOWNER_UIDS:
3610 		/* Just check FD__USE permission */
3611 		err = file_has_perm(cred, file, 0);
3612 		break;
3613 	case F_GETLK:
3614 	case F_SETLK:
3615 	case F_SETLKW:
3616 	case F_OFD_GETLK:
3617 	case F_OFD_SETLK:
3618 	case F_OFD_SETLKW:
3619 #if BITS_PER_LONG == 32
3620 	case F_GETLK64:
3621 	case F_SETLK64:
3622 	case F_SETLKW64:
3623 #endif
3624 		err = file_has_perm(cred, file, FILE__LOCK);
3625 		break;
3626 	}
3627 
3628 	return err;
3629 }
3630 
3631 static void selinux_file_set_fowner(struct file *file)
3632 {
3633 	struct file_security_struct *fsec;
3634 
3635 	fsec = file->f_security;
3636 	fsec->fown_sid = current_sid();
3637 }
3638 
3639 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3640 				       struct fown_struct *fown, int signum)
3641 {
3642 	struct file *file;
3643 	u32 sid = task_sid(tsk);
3644 	u32 perm;
3645 	struct file_security_struct *fsec;
3646 
3647 	/* struct fown_struct is never outside the context of a struct file */
3648 	file = container_of(fown, struct file, f_owner);
3649 
3650 	fsec = file->f_security;
3651 
3652 	if (!signum)
3653 		perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3654 	else
3655 		perm = signal_to_av(signum);
3656 
3657 	return avc_has_perm(fsec->fown_sid, sid,
3658 			    SECCLASS_PROCESS, perm, NULL);
3659 }
3660 
3661 static int selinux_file_receive(struct file *file)
3662 {
3663 	const struct cred *cred = current_cred();
3664 
3665 	return file_has_perm(cred, file, file_to_av(file));
3666 }
3667 
3668 static int selinux_file_open(struct file *file, const struct cred *cred)
3669 {
3670 	struct file_security_struct *fsec;
3671 	struct inode_security_struct *isec;
3672 
3673 	fsec = file->f_security;
3674 	isec = inode_security(file_inode(file));
3675 	/*
3676 	 * Save inode label and policy sequence number
3677 	 * at open-time so that selinux_file_permission
3678 	 * can determine whether revalidation is necessary.
3679 	 * Task label is already saved in the file security
3680 	 * struct as its SID.
3681 	 */
3682 	fsec->isid = isec->sid;
3683 	fsec->pseqno = avc_policy_seqno();
3684 	/*
3685 	 * Since the inode label or policy seqno may have changed
3686 	 * between the selinux_inode_permission check and the saving
3687 	 * of state above, recheck that access is still permitted.
3688 	 * Otherwise, access might never be revalidated against the
3689 	 * new inode label or new policy.
3690 	 * This check is not redundant - do not remove.
3691 	 */
3692 	return file_path_has_perm(cred, file, open_file_to_av(file));
3693 }
3694 
3695 /* task security operations */
3696 
3697 static int selinux_task_create(unsigned long clone_flags)
3698 {
3699 	return current_has_perm(current, PROCESS__FORK);
3700 }
3701 
3702 /*
3703  * allocate the SELinux part of blank credentials
3704  */
3705 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3706 {
3707 	struct task_security_struct *tsec;
3708 
3709 	tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3710 	if (!tsec)
3711 		return -ENOMEM;
3712 
3713 	cred->security = tsec;
3714 	return 0;
3715 }
3716 
3717 /*
3718  * detach and free the LSM part of a set of credentials
3719  */
3720 static void selinux_cred_free(struct cred *cred)
3721 {
3722 	struct task_security_struct *tsec = cred->security;
3723 
3724 	/*
3725 	 * cred->security == NULL if security_cred_alloc_blank() or
3726 	 * security_prepare_creds() returned an error.
3727 	 */
3728 	BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE);
3729 	cred->security = (void *) 0x7UL;
3730 	kfree(tsec);
3731 }
3732 
3733 /*
3734  * prepare a new set of credentials for modification
3735  */
3736 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3737 				gfp_t gfp)
3738 {
3739 	const struct task_security_struct *old_tsec;
3740 	struct task_security_struct *tsec;
3741 
3742 	old_tsec = old->security;
3743 
3744 	tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3745 	if (!tsec)
3746 		return -ENOMEM;
3747 
3748 	new->security = tsec;
3749 	return 0;
3750 }
3751 
3752 /*
3753  * transfer the SELinux data to a blank set of creds
3754  */
3755 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3756 {
3757 	const struct task_security_struct *old_tsec = old->security;
3758 	struct task_security_struct *tsec = new->security;
3759 
3760 	*tsec = *old_tsec;
3761 }
3762 
3763 /*
3764  * set the security data for a kernel service
3765  * - all the creation contexts are set to unlabelled
3766  */
3767 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3768 {
3769 	struct task_security_struct *tsec = new->security;
3770 	u32 sid = current_sid();
3771 	int ret;
3772 
3773 	ret = avc_has_perm(sid, secid,
3774 			   SECCLASS_KERNEL_SERVICE,
3775 			   KERNEL_SERVICE__USE_AS_OVERRIDE,
3776 			   NULL);
3777 	if (ret == 0) {
3778 		tsec->sid = secid;
3779 		tsec->create_sid = 0;
3780 		tsec->keycreate_sid = 0;
3781 		tsec->sockcreate_sid = 0;
3782 	}
3783 	return ret;
3784 }
3785 
3786 /*
3787  * set the file creation context in a security record to the same as the
3788  * objective context of the specified inode
3789  */
3790 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3791 {
3792 	struct inode_security_struct *isec = inode_security(inode);
3793 	struct task_security_struct *tsec = new->security;
3794 	u32 sid = current_sid();
3795 	int ret;
3796 
3797 	ret = avc_has_perm(sid, isec->sid,
3798 			   SECCLASS_KERNEL_SERVICE,
3799 			   KERNEL_SERVICE__CREATE_FILES_AS,
3800 			   NULL);
3801 
3802 	if (ret == 0)
3803 		tsec->create_sid = isec->sid;
3804 	return ret;
3805 }
3806 
3807 static int selinux_kernel_module_request(char *kmod_name)
3808 {
3809 	u32 sid;
3810 	struct common_audit_data ad;
3811 
3812 	sid = task_sid(current);
3813 
3814 	ad.type = LSM_AUDIT_DATA_KMOD;
3815 	ad.u.kmod_name = kmod_name;
3816 
3817 	return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
3818 			    SYSTEM__MODULE_REQUEST, &ad);
3819 }
3820 
3821 static int selinux_kernel_module_from_file(struct file *file)
3822 {
3823 	struct common_audit_data ad;
3824 	struct inode_security_struct *isec;
3825 	struct file_security_struct *fsec;
3826 	u32 sid = current_sid();
3827 	int rc;
3828 
3829 	/* init_module */
3830 	if (file == NULL)
3831 		return avc_has_perm(sid, sid, SECCLASS_SYSTEM,
3832 					SYSTEM__MODULE_LOAD, NULL);
3833 
3834 	/* finit_module */
3835 
3836 	ad.type = LSM_AUDIT_DATA_FILE;
3837 	ad.u.file = file;
3838 
3839 	fsec = file->f_security;
3840 	if (sid != fsec->sid) {
3841 		rc = avc_has_perm(sid, fsec->sid, SECCLASS_FD, FD__USE, &ad);
3842 		if (rc)
3843 			return rc;
3844 	}
3845 
3846 	isec = inode_security(file_inode(file));
3847 	return avc_has_perm(sid, isec->sid, SECCLASS_SYSTEM,
3848 				SYSTEM__MODULE_LOAD, &ad);
3849 }
3850 
3851 static int selinux_kernel_read_file(struct file *file,
3852 				    enum kernel_read_file_id id)
3853 {
3854 	int rc = 0;
3855 
3856 	switch (id) {
3857 	case READING_MODULE:
3858 		rc = selinux_kernel_module_from_file(file);
3859 		break;
3860 	default:
3861 		break;
3862 	}
3863 
3864 	return rc;
3865 }
3866 
3867 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3868 {
3869 	return current_has_perm(p, PROCESS__SETPGID);
3870 }
3871 
3872 static int selinux_task_getpgid(struct task_struct *p)
3873 {
3874 	return current_has_perm(p, PROCESS__GETPGID);
3875 }
3876 
3877 static int selinux_task_getsid(struct task_struct *p)
3878 {
3879 	return current_has_perm(p, PROCESS__GETSESSION);
3880 }
3881 
3882 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3883 {
3884 	*secid = task_sid(p);
3885 }
3886 
3887 static int selinux_task_setnice(struct task_struct *p, int nice)
3888 {
3889 	return current_has_perm(p, PROCESS__SETSCHED);
3890 }
3891 
3892 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3893 {
3894 	return current_has_perm(p, PROCESS__SETSCHED);
3895 }
3896 
3897 static int selinux_task_getioprio(struct task_struct *p)
3898 {
3899 	return current_has_perm(p, PROCESS__GETSCHED);
3900 }
3901 
3902 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
3903 		struct rlimit *new_rlim)
3904 {
3905 	struct rlimit *old_rlim = p->signal->rlim + resource;
3906 
3907 	/* Control the ability to change the hard limit (whether
3908 	   lowering or raising it), so that the hard limit can
3909 	   later be used as a safe reset point for the soft limit
3910 	   upon context transitions.  See selinux_bprm_committing_creds. */
3911 	if (old_rlim->rlim_max != new_rlim->rlim_max)
3912 		return current_has_perm(p, PROCESS__SETRLIMIT);
3913 
3914 	return 0;
3915 }
3916 
3917 static int selinux_task_setscheduler(struct task_struct *p)
3918 {
3919 	return current_has_perm(p, PROCESS__SETSCHED);
3920 }
3921 
3922 static int selinux_task_getscheduler(struct task_struct *p)
3923 {
3924 	return current_has_perm(p, PROCESS__GETSCHED);
3925 }
3926 
3927 static int selinux_task_movememory(struct task_struct *p)
3928 {
3929 	return current_has_perm(p, PROCESS__SETSCHED);
3930 }
3931 
3932 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3933 				int sig, u32 secid)
3934 {
3935 	u32 perm;
3936 	int rc;
3937 
3938 	if (!sig)
3939 		perm = PROCESS__SIGNULL; /* null signal; existence test */
3940 	else
3941 		perm = signal_to_av(sig);
3942 	if (secid)
3943 		rc = avc_has_perm(secid, task_sid(p),
3944 				  SECCLASS_PROCESS, perm, NULL);
3945 	else
3946 		rc = current_has_perm(p, perm);
3947 	return rc;
3948 }
3949 
3950 static int selinux_task_wait(struct task_struct *p)
3951 {
3952 	return task_has_perm(p, current, PROCESS__SIGCHLD);
3953 }
3954 
3955 static void selinux_task_to_inode(struct task_struct *p,
3956 				  struct inode *inode)
3957 {
3958 	struct inode_security_struct *isec = inode->i_security;
3959 	u32 sid = task_sid(p);
3960 
3961 	isec->sid = sid;
3962 	isec->initialized = LABEL_INITIALIZED;
3963 }
3964 
3965 /* Returns error only if unable to parse addresses */
3966 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3967 			struct common_audit_data *ad, u8 *proto)
3968 {
3969 	int offset, ihlen, ret = -EINVAL;
3970 	struct iphdr _iph, *ih;
3971 
3972 	offset = skb_network_offset(skb);
3973 	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3974 	if (ih == NULL)
3975 		goto out;
3976 
3977 	ihlen = ih->ihl * 4;
3978 	if (ihlen < sizeof(_iph))
3979 		goto out;
3980 
3981 	ad->u.net->v4info.saddr = ih->saddr;
3982 	ad->u.net->v4info.daddr = ih->daddr;
3983 	ret = 0;
3984 
3985 	if (proto)
3986 		*proto = ih->protocol;
3987 
3988 	switch (ih->protocol) {
3989 	case IPPROTO_TCP: {
3990 		struct tcphdr _tcph, *th;
3991 
3992 		if (ntohs(ih->frag_off) & IP_OFFSET)
3993 			break;
3994 
3995 		offset += ihlen;
3996 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3997 		if (th == NULL)
3998 			break;
3999 
4000 		ad->u.net->sport = th->source;
4001 		ad->u.net->dport = th->dest;
4002 		break;
4003 	}
4004 
4005 	case IPPROTO_UDP: {
4006 		struct udphdr _udph, *uh;
4007 
4008 		if (ntohs(ih->frag_off) & IP_OFFSET)
4009 			break;
4010 
4011 		offset += ihlen;
4012 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4013 		if (uh == NULL)
4014 			break;
4015 
4016 		ad->u.net->sport = uh->source;
4017 		ad->u.net->dport = uh->dest;
4018 		break;
4019 	}
4020 
4021 	case IPPROTO_DCCP: {
4022 		struct dccp_hdr _dccph, *dh;
4023 
4024 		if (ntohs(ih->frag_off) & IP_OFFSET)
4025 			break;
4026 
4027 		offset += ihlen;
4028 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4029 		if (dh == NULL)
4030 			break;
4031 
4032 		ad->u.net->sport = dh->dccph_sport;
4033 		ad->u.net->dport = dh->dccph_dport;
4034 		break;
4035 	}
4036 
4037 	default:
4038 		break;
4039 	}
4040 out:
4041 	return ret;
4042 }
4043 
4044 #if IS_ENABLED(CONFIG_IPV6)
4045 
4046 /* Returns error only if unable to parse addresses */
4047 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
4048 			struct common_audit_data *ad, u8 *proto)
4049 {
4050 	u8 nexthdr;
4051 	int ret = -EINVAL, offset;
4052 	struct ipv6hdr _ipv6h, *ip6;
4053 	__be16 frag_off;
4054 
4055 	offset = skb_network_offset(skb);
4056 	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
4057 	if (ip6 == NULL)
4058 		goto out;
4059 
4060 	ad->u.net->v6info.saddr = ip6->saddr;
4061 	ad->u.net->v6info.daddr = ip6->daddr;
4062 	ret = 0;
4063 
4064 	nexthdr = ip6->nexthdr;
4065 	offset += sizeof(_ipv6h);
4066 	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
4067 	if (offset < 0)
4068 		goto out;
4069 
4070 	if (proto)
4071 		*proto = nexthdr;
4072 
4073 	switch (nexthdr) {
4074 	case IPPROTO_TCP: {
4075 		struct tcphdr _tcph, *th;
4076 
4077 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4078 		if (th == NULL)
4079 			break;
4080 
4081 		ad->u.net->sport = th->source;
4082 		ad->u.net->dport = th->dest;
4083 		break;
4084 	}
4085 
4086 	case IPPROTO_UDP: {
4087 		struct udphdr _udph, *uh;
4088 
4089 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4090 		if (uh == NULL)
4091 			break;
4092 
4093 		ad->u.net->sport = uh->source;
4094 		ad->u.net->dport = uh->dest;
4095 		break;
4096 	}
4097 
4098 	case IPPROTO_DCCP: {
4099 		struct dccp_hdr _dccph, *dh;
4100 
4101 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4102 		if (dh == NULL)
4103 			break;
4104 
4105 		ad->u.net->sport = dh->dccph_sport;
4106 		ad->u.net->dport = dh->dccph_dport;
4107 		break;
4108 	}
4109 
4110 	/* includes fragments */
4111 	default:
4112 		break;
4113 	}
4114 out:
4115 	return ret;
4116 }
4117 
4118 #endif /* IPV6 */
4119 
4120 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
4121 			     char **_addrp, int src, u8 *proto)
4122 {
4123 	char *addrp;
4124 	int ret;
4125 
4126 	switch (ad->u.net->family) {
4127 	case PF_INET:
4128 		ret = selinux_parse_skb_ipv4(skb, ad, proto);
4129 		if (ret)
4130 			goto parse_error;
4131 		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
4132 				       &ad->u.net->v4info.daddr);
4133 		goto okay;
4134 
4135 #if IS_ENABLED(CONFIG_IPV6)
4136 	case PF_INET6:
4137 		ret = selinux_parse_skb_ipv6(skb, ad, proto);
4138 		if (ret)
4139 			goto parse_error;
4140 		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
4141 				       &ad->u.net->v6info.daddr);
4142 		goto okay;
4143 #endif	/* IPV6 */
4144 	default:
4145 		addrp = NULL;
4146 		goto okay;
4147 	}
4148 
4149 parse_error:
4150 	printk(KERN_WARNING
4151 	       "SELinux: failure in selinux_parse_skb(),"
4152 	       " unable to parse packet\n");
4153 	return ret;
4154 
4155 okay:
4156 	if (_addrp)
4157 		*_addrp = addrp;
4158 	return 0;
4159 }
4160 
4161 /**
4162  * selinux_skb_peerlbl_sid - Determine the peer label of a packet
4163  * @skb: the packet
4164  * @family: protocol family
4165  * @sid: the packet's peer label SID
4166  *
4167  * Description:
4168  * Check the various different forms of network peer labeling and determine
4169  * the peer label/SID for the packet; most of the magic actually occurs in
4170  * the security server function security_net_peersid_cmp().  The function
4171  * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
4172  * or -EACCES if @sid is invalid due to inconsistencies with the different
4173  * peer labels.
4174  *
4175  */
4176 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
4177 {
4178 	int err;
4179 	u32 xfrm_sid;
4180 	u32 nlbl_sid;
4181 	u32 nlbl_type;
4182 
4183 	err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
4184 	if (unlikely(err))
4185 		return -EACCES;
4186 	err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
4187 	if (unlikely(err))
4188 		return -EACCES;
4189 
4190 	err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
4191 	if (unlikely(err)) {
4192 		printk(KERN_WARNING
4193 		       "SELinux: failure in selinux_skb_peerlbl_sid(),"
4194 		       " unable to determine packet's peer label\n");
4195 		return -EACCES;
4196 	}
4197 
4198 	return 0;
4199 }
4200 
4201 /**
4202  * selinux_conn_sid - Determine the child socket label for a connection
4203  * @sk_sid: the parent socket's SID
4204  * @skb_sid: the packet's SID
4205  * @conn_sid: the resulting connection SID
4206  *
4207  * If @skb_sid is valid then the user:role:type information from @sk_sid is
4208  * combined with the MLS information from @skb_sid in order to create
4209  * @conn_sid.  If @skb_sid is not valid then then @conn_sid is simply a copy
4210  * of @sk_sid.  Returns zero on success, negative values on failure.
4211  *
4212  */
4213 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
4214 {
4215 	int err = 0;
4216 
4217 	if (skb_sid != SECSID_NULL)
4218 		err = security_sid_mls_copy(sk_sid, skb_sid, conn_sid);
4219 	else
4220 		*conn_sid = sk_sid;
4221 
4222 	return err;
4223 }
4224 
4225 /* socket security operations */
4226 
4227 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
4228 				 u16 secclass, u32 *socksid)
4229 {
4230 	if (tsec->sockcreate_sid > SECSID_NULL) {
4231 		*socksid = tsec->sockcreate_sid;
4232 		return 0;
4233 	}
4234 
4235 	return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
4236 				       socksid);
4237 }
4238 
4239 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
4240 {
4241 	struct sk_security_struct *sksec = sk->sk_security;
4242 	struct common_audit_data ad;
4243 	struct lsm_network_audit net = {0,};
4244 	u32 tsid = task_sid(task);
4245 
4246 	if (sksec->sid == SECINITSID_KERNEL)
4247 		return 0;
4248 
4249 	ad.type = LSM_AUDIT_DATA_NET;
4250 	ad.u.net = &net;
4251 	ad.u.net->sk = sk;
4252 
4253 	return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
4254 }
4255 
4256 static int selinux_socket_create(int family, int type,
4257 				 int protocol, int kern)
4258 {
4259 	const struct task_security_struct *tsec = current_security();
4260 	u32 newsid;
4261 	u16 secclass;
4262 	int rc;
4263 
4264 	if (kern)
4265 		return 0;
4266 
4267 	secclass = socket_type_to_security_class(family, type, protocol);
4268 	rc = socket_sockcreate_sid(tsec, secclass, &newsid);
4269 	if (rc)
4270 		return rc;
4271 
4272 	return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
4273 }
4274 
4275 static int selinux_socket_post_create(struct socket *sock, int family,
4276 				      int type, int protocol, int kern)
4277 {
4278 	const struct task_security_struct *tsec = current_security();
4279 	struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
4280 	struct sk_security_struct *sksec;
4281 	int err = 0;
4282 
4283 	isec->sclass = socket_type_to_security_class(family, type, protocol);
4284 
4285 	if (kern)
4286 		isec->sid = SECINITSID_KERNEL;
4287 	else {
4288 		err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
4289 		if (err)
4290 			return err;
4291 	}
4292 
4293 	isec->initialized = LABEL_INITIALIZED;
4294 
4295 	if (sock->sk) {
4296 		sksec = sock->sk->sk_security;
4297 		sksec->sid = isec->sid;
4298 		sksec->sclass = isec->sclass;
4299 		err = selinux_netlbl_socket_post_create(sock->sk, family);
4300 	}
4301 
4302 	return err;
4303 }
4304 
4305 /* Range of port numbers used to automatically bind.
4306    Need to determine whether we should perform a name_bind
4307    permission check between the socket and the port number. */
4308 
4309 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
4310 {
4311 	struct sock *sk = sock->sk;
4312 	u16 family;
4313 	int err;
4314 
4315 	err = sock_has_perm(current, sk, SOCKET__BIND);
4316 	if (err)
4317 		goto out;
4318 
4319 	/*
4320 	 * If PF_INET or PF_INET6, check name_bind permission for the port.
4321 	 * Multiple address binding for SCTP is not supported yet: we just
4322 	 * check the first address now.
4323 	 */
4324 	family = sk->sk_family;
4325 	if (family == PF_INET || family == PF_INET6) {
4326 		char *addrp;
4327 		struct sk_security_struct *sksec = sk->sk_security;
4328 		struct common_audit_data ad;
4329 		struct lsm_network_audit net = {0,};
4330 		struct sockaddr_in *addr4 = NULL;
4331 		struct sockaddr_in6 *addr6 = NULL;
4332 		unsigned short snum;
4333 		u32 sid, node_perm;
4334 
4335 		if (family == PF_INET) {
4336 			addr4 = (struct sockaddr_in *)address;
4337 			snum = ntohs(addr4->sin_port);
4338 			addrp = (char *)&addr4->sin_addr.s_addr;
4339 		} else {
4340 			addr6 = (struct sockaddr_in6 *)address;
4341 			snum = ntohs(addr6->sin6_port);
4342 			addrp = (char *)&addr6->sin6_addr.s6_addr;
4343 		}
4344 
4345 		if (snum) {
4346 			int low, high;
4347 
4348 			inet_get_local_port_range(sock_net(sk), &low, &high);
4349 
4350 			if (snum < max(PROT_SOCK, low) || snum > high) {
4351 				err = sel_netport_sid(sk->sk_protocol,
4352 						      snum, &sid);
4353 				if (err)
4354 					goto out;
4355 				ad.type = LSM_AUDIT_DATA_NET;
4356 				ad.u.net = &net;
4357 				ad.u.net->sport = htons(snum);
4358 				ad.u.net->family = family;
4359 				err = avc_has_perm(sksec->sid, sid,
4360 						   sksec->sclass,
4361 						   SOCKET__NAME_BIND, &ad);
4362 				if (err)
4363 					goto out;
4364 			}
4365 		}
4366 
4367 		switch (sksec->sclass) {
4368 		case SECCLASS_TCP_SOCKET:
4369 			node_perm = TCP_SOCKET__NODE_BIND;
4370 			break;
4371 
4372 		case SECCLASS_UDP_SOCKET:
4373 			node_perm = UDP_SOCKET__NODE_BIND;
4374 			break;
4375 
4376 		case SECCLASS_DCCP_SOCKET:
4377 			node_perm = DCCP_SOCKET__NODE_BIND;
4378 			break;
4379 
4380 		default:
4381 			node_perm = RAWIP_SOCKET__NODE_BIND;
4382 			break;
4383 		}
4384 
4385 		err = sel_netnode_sid(addrp, family, &sid);
4386 		if (err)
4387 			goto out;
4388 
4389 		ad.type = LSM_AUDIT_DATA_NET;
4390 		ad.u.net = &net;
4391 		ad.u.net->sport = htons(snum);
4392 		ad.u.net->family = family;
4393 
4394 		if (family == PF_INET)
4395 			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
4396 		else
4397 			ad.u.net->v6info.saddr = addr6->sin6_addr;
4398 
4399 		err = avc_has_perm(sksec->sid, sid,
4400 				   sksec->sclass, node_perm, &ad);
4401 		if (err)
4402 			goto out;
4403 	}
4404 out:
4405 	return err;
4406 }
4407 
4408 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
4409 {
4410 	struct sock *sk = sock->sk;
4411 	struct sk_security_struct *sksec = sk->sk_security;
4412 	int err;
4413 
4414 	err = sock_has_perm(current, sk, SOCKET__CONNECT);
4415 	if (err)
4416 		return err;
4417 
4418 	/*
4419 	 * If a TCP or DCCP socket, check name_connect permission for the port.
4420 	 */
4421 	if (sksec->sclass == SECCLASS_TCP_SOCKET ||
4422 	    sksec->sclass == SECCLASS_DCCP_SOCKET) {
4423 		struct common_audit_data ad;
4424 		struct lsm_network_audit net = {0,};
4425 		struct sockaddr_in *addr4 = NULL;
4426 		struct sockaddr_in6 *addr6 = NULL;
4427 		unsigned short snum;
4428 		u32 sid, perm;
4429 
4430 		if (sk->sk_family == PF_INET) {
4431 			addr4 = (struct sockaddr_in *)address;
4432 			if (addrlen < sizeof(struct sockaddr_in))
4433 				return -EINVAL;
4434 			snum = ntohs(addr4->sin_port);
4435 		} else {
4436 			addr6 = (struct sockaddr_in6 *)address;
4437 			if (addrlen < SIN6_LEN_RFC2133)
4438 				return -EINVAL;
4439 			snum = ntohs(addr6->sin6_port);
4440 		}
4441 
4442 		err = sel_netport_sid(sk->sk_protocol, snum, &sid);
4443 		if (err)
4444 			goto out;
4445 
4446 		perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
4447 		       TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
4448 
4449 		ad.type = LSM_AUDIT_DATA_NET;
4450 		ad.u.net = &net;
4451 		ad.u.net->dport = htons(snum);
4452 		ad.u.net->family = sk->sk_family;
4453 		err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
4454 		if (err)
4455 			goto out;
4456 	}
4457 
4458 	err = selinux_netlbl_socket_connect(sk, address);
4459 
4460 out:
4461 	return err;
4462 }
4463 
4464 static int selinux_socket_listen(struct socket *sock, int backlog)
4465 {
4466 	return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
4467 }
4468 
4469 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
4470 {
4471 	int err;
4472 	struct inode_security_struct *isec;
4473 	struct inode_security_struct *newisec;
4474 
4475 	err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
4476 	if (err)
4477 		return err;
4478 
4479 	newisec = inode_security_novalidate(SOCK_INODE(newsock));
4480 
4481 	isec = inode_security_novalidate(SOCK_INODE(sock));
4482 	newisec->sclass = isec->sclass;
4483 	newisec->sid = isec->sid;
4484 	newisec->initialized = LABEL_INITIALIZED;
4485 
4486 	return 0;
4487 }
4488 
4489 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4490 				  int size)
4491 {
4492 	return sock_has_perm(current, sock->sk, SOCKET__WRITE);
4493 }
4494 
4495 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4496 				  int size, int flags)
4497 {
4498 	return sock_has_perm(current, sock->sk, SOCKET__READ);
4499 }
4500 
4501 static int selinux_socket_getsockname(struct socket *sock)
4502 {
4503 	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4504 }
4505 
4506 static int selinux_socket_getpeername(struct socket *sock)
4507 {
4508 	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4509 }
4510 
4511 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4512 {
4513 	int err;
4514 
4515 	err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
4516 	if (err)
4517 		return err;
4518 
4519 	return selinux_netlbl_socket_setsockopt(sock, level, optname);
4520 }
4521 
4522 static int selinux_socket_getsockopt(struct socket *sock, int level,
4523 				     int optname)
4524 {
4525 	return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
4526 }
4527 
4528 static int selinux_socket_shutdown(struct socket *sock, int how)
4529 {
4530 	return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
4531 }
4532 
4533 static int selinux_socket_unix_stream_connect(struct sock *sock,
4534 					      struct sock *other,
4535 					      struct sock *newsk)
4536 {
4537 	struct sk_security_struct *sksec_sock = sock->sk_security;
4538 	struct sk_security_struct *sksec_other = other->sk_security;
4539 	struct sk_security_struct *sksec_new = newsk->sk_security;
4540 	struct common_audit_data ad;
4541 	struct lsm_network_audit net = {0,};
4542 	int err;
4543 
4544 	ad.type = LSM_AUDIT_DATA_NET;
4545 	ad.u.net = &net;
4546 	ad.u.net->sk = other;
4547 
4548 	err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
4549 			   sksec_other->sclass,
4550 			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
4551 	if (err)
4552 		return err;
4553 
4554 	/* server child socket */
4555 	sksec_new->peer_sid = sksec_sock->sid;
4556 	err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
4557 				    &sksec_new->sid);
4558 	if (err)
4559 		return err;
4560 
4561 	/* connecting socket */
4562 	sksec_sock->peer_sid = sksec_new->sid;
4563 
4564 	return 0;
4565 }
4566 
4567 static int selinux_socket_unix_may_send(struct socket *sock,
4568 					struct socket *other)
4569 {
4570 	struct sk_security_struct *ssec = sock->sk->sk_security;
4571 	struct sk_security_struct *osec = other->sk->sk_security;
4572 	struct common_audit_data ad;
4573 	struct lsm_network_audit net = {0,};
4574 
4575 	ad.type = LSM_AUDIT_DATA_NET;
4576 	ad.u.net = &net;
4577 	ad.u.net->sk = other->sk;
4578 
4579 	return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
4580 			    &ad);
4581 }
4582 
4583 static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
4584 				    char *addrp, u16 family, u32 peer_sid,
4585 				    struct common_audit_data *ad)
4586 {
4587 	int err;
4588 	u32 if_sid;
4589 	u32 node_sid;
4590 
4591 	err = sel_netif_sid(ns, ifindex, &if_sid);
4592 	if (err)
4593 		return err;
4594 	err = avc_has_perm(peer_sid, if_sid,
4595 			   SECCLASS_NETIF, NETIF__INGRESS, ad);
4596 	if (err)
4597 		return err;
4598 
4599 	err = sel_netnode_sid(addrp, family, &node_sid);
4600 	if (err)
4601 		return err;
4602 	return avc_has_perm(peer_sid, node_sid,
4603 			    SECCLASS_NODE, NODE__RECVFROM, ad);
4604 }
4605 
4606 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4607 				       u16 family)
4608 {
4609 	int err = 0;
4610 	struct sk_security_struct *sksec = sk->sk_security;
4611 	u32 sk_sid = sksec->sid;
4612 	struct common_audit_data ad;
4613 	struct lsm_network_audit net = {0,};
4614 	char *addrp;
4615 
4616 	ad.type = LSM_AUDIT_DATA_NET;
4617 	ad.u.net = &net;
4618 	ad.u.net->netif = skb->skb_iif;
4619 	ad.u.net->family = family;
4620 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4621 	if (err)
4622 		return err;
4623 
4624 	if (selinux_secmark_enabled()) {
4625 		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4626 				   PACKET__RECV, &ad);
4627 		if (err)
4628 			return err;
4629 	}
4630 
4631 	err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4632 	if (err)
4633 		return err;
4634 	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4635 
4636 	return err;
4637 }
4638 
4639 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4640 {
4641 	int err;
4642 	struct sk_security_struct *sksec = sk->sk_security;
4643 	u16 family = sk->sk_family;
4644 	u32 sk_sid = sksec->sid;
4645 	struct common_audit_data ad;
4646 	struct lsm_network_audit net = {0,};
4647 	char *addrp;
4648 	u8 secmark_active;
4649 	u8 peerlbl_active;
4650 
4651 	if (family != PF_INET && family != PF_INET6)
4652 		return 0;
4653 
4654 	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
4655 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4656 		family = PF_INET;
4657 
4658 	/* If any sort of compatibility mode is enabled then handoff processing
4659 	 * to the selinux_sock_rcv_skb_compat() function to deal with the
4660 	 * special handling.  We do this in an attempt to keep this function
4661 	 * as fast and as clean as possible. */
4662 	if (!selinux_policycap_netpeer)
4663 		return selinux_sock_rcv_skb_compat(sk, skb, family);
4664 
4665 	secmark_active = selinux_secmark_enabled();
4666 	peerlbl_active = selinux_peerlbl_enabled();
4667 	if (!secmark_active && !peerlbl_active)
4668 		return 0;
4669 
4670 	ad.type = LSM_AUDIT_DATA_NET;
4671 	ad.u.net = &net;
4672 	ad.u.net->netif = skb->skb_iif;
4673 	ad.u.net->family = family;
4674 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4675 	if (err)
4676 		return err;
4677 
4678 	if (peerlbl_active) {
4679 		u32 peer_sid;
4680 
4681 		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4682 		if (err)
4683 			return err;
4684 		err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
4685 					       addrp, family, peer_sid, &ad);
4686 		if (err) {
4687 			selinux_netlbl_err(skb, family, err, 0);
4688 			return err;
4689 		}
4690 		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4691 				   PEER__RECV, &ad);
4692 		if (err) {
4693 			selinux_netlbl_err(skb, family, err, 0);
4694 			return err;
4695 		}
4696 	}
4697 
4698 	if (secmark_active) {
4699 		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4700 				   PACKET__RECV, &ad);
4701 		if (err)
4702 			return err;
4703 	}
4704 
4705 	return err;
4706 }
4707 
4708 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4709 					    int __user *optlen, unsigned len)
4710 {
4711 	int err = 0;
4712 	char *scontext;
4713 	u32 scontext_len;
4714 	struct sk_security_struct *sksec = sock->sk->sk_security;
4715 	u32 peer_sid = SECSID_NULL;
4716 
4717 	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4718 	    sksec->sclass == SECCLASS_TCP_SOCKET)
4719 		peer_sid = sksec->peer_sid;
4720 	if (peer_sid == SECSID_NULL)
4721 		return -ENOPROTOOPT;
4722 
4723 	err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4724 	if (err)
4725 		return err;
4726 
4727 	if (scontext_len > len) {
4728 		err = -ERANGE;
4729 		goto out_len;
4730 	}
4731 
4732 	if (copy_to_user(optval, scontext, scontext_len))
4733 		err = -EFAULT;
4734 
4735 out_len:
4736 	if (put_user(scontext_len, optlen))
4737 		err = -EFAULT;
4738 	kfree(scontext);
4739 	return err;
4740 }
4741 
4742 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4743 {
4744 	u32 peer_secid = SECSID_NULL;
4745 	u16 family;
4746 	struct inode_security_struct *isec;
4747 
4748 	if (skb && skb->protocol == htons(ETH_P_IP))
4749 		family = PF_INET;
4750 	else if (skb && skb->protocol == htons(ETH_P_IPV6))
4751 		family = PF_INET6;
4752 	else if (sock)
4753 		family = sock->sk->sk_family;
4754 	else
4755 		goto out;
4756 
4757 	if (sock && family == PF_UNIX) {
4758 		isec = inode_security_novalidate(SOCK_INODE(sock));
4759 		peer_secid = isec->sid;
4760 	} else if (skb)
4761 		selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4762 
4763 out:
4764 	*secid = peer_secid;
4765 	if (peer_secid == SECSID_NULL)
4766 		return -EINVAL;
4767 	return 0;
4768 }
4769 
4770 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4771 {
4772 	struct sk_security_struct *sksec;
4773 
4774 	sksec = kzalloc(sizeof(*sksec), priority);
4775 	if (!sksec)
4776 		return -ENOMEM;
4777 
4778 	sksec->peer_sid = SECINITSID_UNLABELED;
4779 	sksec->sid = SECINITSID_UNLABELED;
4780 	sksec->sclass = SECCLASS_SOCKET;
4781 	selinux_netlbl_sk_security_reset(sksec);
4782 	sk->sk_security = sksec;
4783 
4784 	return 0;
4785 }
4786 
4787 static void selinux_sk_free_security(struct sock *sk)
4788 {
4789 	struct sk_security_struct *sksec = sk->sk_security;
4790 
4791 	sk->sk_security = NULL;
4792 	selinux_netlbl_sk_security_free(sksec);
4793 	kfree(sksec);
4794 }
4795 
4796 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4797 {
4798 	struct sk_security_struct *sksec = sk->sk_security;
4799 	struct sk_security_struct *newsksec = newsk->sk_security;
4800 
4801 	newsksec->sid = sksec->sid;
4802 	newsksec->peer_sid = sksec->peer_sid;
4803 	newsksec->sclass = sksec->sclass;
4804 
4805 	selinux_netlbl_sk_security_reset(newsksec);
4806 }
4807 
4808 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4809 {
4810 	if (!sk)
4811 		*secid = SECINITSID_ANY_SOCKET;
4812 	else {
4813 		struct sk_security_struct *sksec = sk->sk_security;
4814 
4815 		*secid = sksec->sid;
4816 	}
4817 }
4818 
4819 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4820 {
4821 	struct inode_security_struct *isec =
4822 		inode_security_novalidate(SOCK_INODE(parent));
4823 	struct sk_security_struct *sksec = sk->sk_security;
4824 
4825 	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4826 	    sk->sk_family == PF_UNIX)
4827 		isec->sid = sksec->sid;
4828 	sksec->sclass = isec->sclass;
4829 }
4830 
4831 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4832 				     struct request_sock *req)
4833 {
4834 	struct sk_security_struct *sksec = sk->sk_security;
4835 	int err;
4836 	u16 family = req->rsk_ops->family;
4837 	u32 connsid;
4838 	u32 peersid;
4839 
4840 	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4841 	if (err)
4842 		return err;
4843 	err = selinux_conn_sid(sksec->sid, peersid, &connsid);
4844 	if (err)
4845 		return err;
4846 	req->secid = connsid;
4847 	req->peer_secid = peersid;
4848 
4849 	return selinux_netlbl_inet_conn_request(req, family);
4850 }
4851 
4852 static void selinux_inet_csk_clone(struct sock *newsk,
4853 				   const struct request_sock *req)
4854 {
4855 	struct sk_security_struct *newsksec = newsk->sk_security;
4856 
4857 	newsksec->sid = req->secid;
4858 	newsksec->peer_sid = req->peer_secid;
4859 	/* NOTE: Ideally, we should also get the isec->sid for the
4860 	   new socket in sync, but we don't have the isec available yet.
4861 	   So we will wait until sock_graft to do it, by which
4862 	   time it will have been created and available. */
4863 
4864 	/* We don't need to take any sort of lock here as we are the only
4865 	 * thread with access to newsksec */
4866 	selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4867 }
4868 
4869 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4870 {
4871 	u16 family = sk->sk_family;
4872 	struct sk_security_struct *sksec = sk->sk_security;
4873 
4874 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
4875 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4876 		family = PF_INET;
4877 
4878 	selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4879 }
4880 
4881 static int selinux_secmark_relabel_packet(u32 sid)
4882 {
4883 	const struct task_security_struct *__tsec;
4884 	u32 tsid;
4885 
4886 	__tsec = current_security();
4887 	tsid = __tsec->sid;
4888 
4889 	return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
4890 }
4891 
4892 static void selinux_secmark_refcount_inc(void)
4893 {
4894 	atomic_inc(&selinux_secmark_refcount);
4895 }
4896 
4897 static void selinux_secmark_refcount_dec(void)
4898 {
4899 	atomic_dec(&selinux_secmark_refcount);
4900 }
4901 
4902 static void selinux_req_classify_flow(const struct request_sock *req,
4903 				      struct flowi *fl)
4904 {
4905 	fl->flowi_secid = req->secid;
4906 }
4907 
4908 static int selinux_tun_dev_alloc_security(void **security)
4909 {
4910 	struct tun_security_struct *tunsec;
4911 
4912 	tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL);
4913 	if (!tunsec)
4914 		return -ENOMEM;
4915 	tunsec->sid = current_sid();
4916 
4917 	*security = tunsec;
4918 	return 0;
4919 }
4920 
4921 static void selinux_tun_dev_free_security(void *security)
4922 {
4923 	kfree(security);
4924 }
4925 
4926 static int selinux_tun_dev_create(void)
4927 {
4928 	u32 sid = current_sid();
4929 
4930 	/* we aren't taking into account the "sockcreate" SID since the socket
4931 	 * that is being created here is not a socket in the traditional sense,
4932 	 * instead it is a private sock, accessible only to the kernel, and
4933 	 * representing a wide range of network traffic spanning multiple
4934 	 * connections unlike traditional sockets - check the TUN driver to
4935 	 * get a better understanding of why this socket is special */
4936 
4937 	return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4938 			    NULL);
4939 }
4940 
4941 static int selinux_tun_dev_attach_queue(void *security)
4942 {
4943 	struct tun_security_struct *tunsec = security;
4944 
4945 	return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
4946 			    TUN_SOCKET__ATTACH_QUEUE, NULL);
4947 }
4948 
4949 static int selinux_tun_dev_attach(struct sock *sk, void *security)
4950 {
4951 	struct tun_security_struct *tunsec = security;
4952 	struct sk_security_struct *sksec = sk->sk_security;
4953 
4954 	/* we don't currently perform any NetLabel based labeling here and it
4955 	 * isn't clear that we would want to do so anyway; while we could apply
4956 	 * labeling without the support of the TUN user the resulting labeled
4957 	 * traffic from the other end of the connection would almost certainly
4958 	 * cause confusion to the TUN user that had no idea network labeling
4959 	 * protocols were being used */
4960 
4961 	sksec->sid = tunsec->sid;
4962 	sksec->sclass = SECCLASS_TUN_SOCKET;
4963 
4964 	return 0;
4965 }
4966 
4967 static int selinux_tun_dev_open(void *security)
4968 {
4969 	struct tun_security_struct *tunsec = security;
4970 	u32 sid = current_sid();
4971 	int err;
4972 
4973 	err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
4974 			   TUN_SOCKET__RELABELFROM, NULL);
4975 	if (err)
4976 		return err;
4977 	err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4978 			   TUN_SOCKET__RELABELTO, NULL);
4979 	if (err)
4980 		return err;
4981 	tunsec->sid = sid;
4982 
4983 	return 0;
4984 }
4985 
4986 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4987 {
4988 	int err = 0;
4989 	u32 perm;
4990 	struct nlmsghdr *nlh;
4991 	struct sk_security_struct *sksec = sk->sk_security;
4992 
4993 	if (skb->len < NLMSG_HDRLEN) {
4994 		err = -EINVAL;
4995 		goto out;
4996 	}
4997 	nlh = nlmsg_hdr(skb);
4998 
4999 	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
5000 	if (err) {
5001 		if (err == -EINVAL) {
5002 			pr_warn_ratelimited("SELinux: unrecognized netlink"
5003 			       " message: protocol=%hu nlmsg_type=%hu sclass=%s"
5004 			       " pig=%d comm=%s\n",
5005 			       sk->sk_protocol, nlh->nlmsg_type,
5006 			       secclass_map[sksec->sclass - 1].name,
5007 			       task_pid_nr(current), current->comm);
5008 			if (!selinux_enforcing || security_get_allow_unknown())
5009 				err = 0;
5010 		}
5011 
5012 		/* Ignore */
5013 		if (err == -ENOENT)
5014 			err = 0;
5015 		goto out;
5016 	}
5017 
5018 	err = sock_has_perm(current, sk, perm);
5019 out:
5020 	return err;
5021 }
5022 
5023 #ifdef CONFIG_NETFILTER
5024 
5025 static unsigned int selinux_ip_forward(struct sk_buff *skb,
5026 				       const struct net_device *indev,
5027 				       u16 family)
5028 {
5029 	int err;
5030 	char *addrp;
5031 	u32 peer_sid;
5032 	struct common_audit_data ad;
5033 	struct lsm_network_audit net = {0,};
5034 	u8 secmark_active;
5035 	u8 netlbl_active;
5036 	u8 peerlbl_active;
5037 
5038 	if (!selinux_policycap_netpeer)
5039 		return NF_ACCEPT;
5040 
5041 	secmark_active = selinux_secmark_enabled();
5042 	netlbl_active = netlbl_enabled();
5043 	peerlbl_active = selinux_peerlbl_enabled();
5044 	if (!secmark_active && !peerlbl_active)
5045 		return NF_ACCEPT;
5046 
5047 	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
5048 		return NF_DROP;
5049 
5050 	ad.type = LSM_AUDIT_DATA_NET;
5051 	ad.u.net = &net;
5052 	ad.u.net->netif = indev->ifindex;
5053 	ad.u.net->family = family;
5054 	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
5055 		return NF_DROP;
5056 
5057 	if (peerlbl_active) {
5058 		err = selinux_inet_sys_rcv_skb(dev_net(indev), indev->ifindex,
5059 					       addrp, family, peer_sid, &ad);
5060 		if (err) {
5061 			selinux_netlbl_err(skb, family, err, 1);
5062 			return NF_DROP;
5063 		}
5064 	}
5065 
5066 	if (secmark_active)
5067 		if (avc_has_perm(peer_sid, skb->secmark,
5068 				 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
5069 			return NF_DROP;
5070 
5071 	if (netlbl_active)
5072 		/* we do this in the FORWARD path and not the POST_ROUTING
5073 		 * path because we want to make sure we apply the necessary
5074 		 * labeling before IPsec is applied so we can leverage AH
5075 		 * protection */
5076 		if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
5077 			return NF_DROP;
5078 
5079 	return NF_ACCEPT;
5080 }
5081 
5082 static unsigned int selinux_ipv4_forward(void *priv,
5083 					 struct sk_buff *skb,
5084 					 const struct nf_hook_state *state)
5085 {
5086 	return selinux_ip_forward(skb, state->in, PF_INET);
5087 }
5088 
5089 #if IS_ENABLED(CONFIG_IPV6)
5090 static unsigned int selinux_ipv6_forward(void *priv,
5091 					 struct sk_buff *skb,
5092 					 const struct nf_hook_state *state)
5093 {
5094 	return selinux_ip_forward(skb, state->in, PF_INET6);
5095 }
5096 #endif	/* IPV6 */
5097 
5098 static unsigned int selinux_ip_output(struct sk_buff *skb,
5099 				      u16 family)
5100 {
5101 	struct sock *sk;
5102 	u32 sid;
5103 
5104 	if (!netlbl_enabled())
5105 		return NF_ACCEPT;
5106 
5107 	/* we do this in the LOCAL_OUT path and not the POST_ROUTING path
5108 	 * because we want to make sure we apply the necessary labeling
5109 	 * before IPsec is applied so we can leverage AH protection */
5110 	sk = skb->sk;
5111 	if (sk) {
5112 		struct sk_security_struct *sksec;
5113 
5114 		if (sk_listener(sk))
5115 			/* if the socket is the listening state then this
5116 			 * packet is a SYN-ACK packet which means it needs to
5117 			 * be labeled based on the connection/request_sock and
5118 			 * not the parent socket.  unfortunately, we can't
5119 			 * lookup the request_sock yet as it isn't queued on
5120 			 * the parent socket until after the SYN-ACK is sent.
5121 			 * the "solution" is to simply pass the packet as-is
5122 			 * as any IP option based labeling should be copied
5123 			 * from the initial connection request (in the IP
5124 			 * layer).  it is far from ideal, but until we get a
5125 			 * security label in the packet itself this is the
5126 			 * best we can do. */
5127 			return NF_ACCEPT;
5128 
5129 		/* standard practice, label using the parent socket */
5130 		sksec = sk->sk_security;
5131 		sid = sksec->sid;
5132 	} else
5133 		sid = SECINITSID_KERNEL;
5134 	if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
5135 		return NF_DROP;
5136 
5137 	return NF_ACCEPT;
5138 }
5139 
5140 static unsigned int selinux_ipv4_output(void *priv,
5141 					struct sk_buff *skb,
5142 					const struct nf_hook_state *state)
5143 {
5144 	return selinux_ip_output(skb, PF_INET);
5145 }
5146 
5147 #if IS_ENABLED(CONFIG_IPV6)
5148 static unsigned int selinux_ipv6_output(void *priv,
5149 					struct sk_buff *skb,
5150 					const struct nf_hook_state *state)
5151 {
5152 	return selinux_ip_output(skb, PF_INET6);
5153 }
5154 #endif	/* IPV6 */
5155 
5156 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
5157 						int ifindex,
5158 						u16 family)
5159 {
5160 	struct sock *sk = skb_to_full_sk(skb);
5161 	struct sk_security_struct *sksec;
5162 	struct common_audit_data ad;
5163 	struct lsm_network_audit net = {0,};
5164 	char *addrp;
5165 	u8 proto;
5166 
5167 	if (sk == NULL)
5168 		return NF_ACCEPT;
5169 	sksec = sk->sk_security;
5170 
5171 	ad.type = LSM_AUDIT_DATA_NET;
5172 	ad.u.net = &net;
5173 	ad.u.net->netif = ifindex;
5174 	ad.u.net->family = family;
5175 	if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
5176 		return NF_DROP;
5177 
5178 	if (selinux_secmark_enabled())
5179 		if (avc_has_perm(sksec->sid, skb->secmark,
5180 				 SECCLASS_PACKET, PACKET__SEND, &ad))
5181 			return NF_DROP_ERR(-ECONNREFUSED);
5182 
5183 	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
5184 		return NF_DROP_ERR(-ECONNREFUSED);
5185 
5186 	return NF_ACCEPT;
5187 }
5188 
5189 static unsigned int selinux_ip_postroute(struct sk_buff *skb,
5190 					 const struct net_device *outdev,
5191 					 u16 family)
5192 {
5193 	u32 secmark_perm;
5194 	u32 peer_sid;
5195 	int ifindex = outdev->ifindex;
5196 	struct sock *sk;
5197 	struct common_audit_data ad;
5198 	struct lsm_network_audit net = {0,};
5199 	char *addrp;
5200 	u8 secmark_active;
5201 	u8 peerlbl_active;
5202 
5203 	/* If any sort of compatibility mode is enabled then handoff processing
5204 	 * to the selinux_ip_postroute_compat() function to deal with the
5205 	 * special handling.  We do this in an attempt to keep this function
5206 	 * as fast and as clean as possible. */
5207 	if (!selinux_policycap_netpeer)
5208 		return selinux_ip_postroute_compat(skb, ifindex, family);
5209 
5210 	secmark_active = selinux_secmark_enabled();
5211 	peerlbl_active = selinux_peerlbl_enabled();
5212 	if (!secmark_active && !peerlbl_active)
5213 		return NF_ACCEPT;
5214 
5215 	sk = skb_to_full_sk(skb);
5216 
5217 #ifdef CONFIG_XFRM
5218 	/* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
5219 	 * packet transformation so allow the packet to pass without any checks
5220 	 * since we'll have another chance to perform access control checks
5221 	 * when the packet is on it's final way out.
5222 	 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
5223 	 *       is NULL, in this case go ahead and apply access control.
5224 	 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
5225 	 *       TCP listening state we cannot wait until the XFRM processing
5226 	 *       is done as we will miss out on the SA label if we do;
5227 	 *       unfortunately, this means more work, but it is only once per
5228 	 *       connection. */
5229 	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
5230 	    !(sk && sk_listener(sk)))
5231 		return NF_ACCEPT;
5232 #endif
5233 
5234 	if (sk == NULL) {
5235 		/* Without an associated socket the packet is either coming
5236 		 * from the kernel or it is being forwarded; check the packet
5237 		 * to determine which and if the packet is being forwarded
5238 		 * query the packet directly to determine the security label. */
5239 		if (skb->skb_iif) {
5240 			secmark_perm = PACKET__FORWARD_OUT;
5241 			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5242 				return NF_DROP;
5243 		} else {
5244 			secmark_perm = PACKET__SEND;
5245 			peer_sid = SECINITSID_KERNEL;
5246 		}
5247 	} else if (sk_listener(sk)) {
5248 		/* Locally generated packet but the associated socket is in the
5249 		 * listening state which means this is a SYN-ACK packet.  In
5250 		 * this particular case the correct security label is assigned
5251 		 * to the connection/request_sock but unfortunately we can't
5252 		 * query the request_sock as it isn't queued on the parent
5253 		 * socket until after the SYN-ACK packet is sent; the only
5254 		 * viable choice is to regenerate the label like we do in
5255 		 * selinux_inet_conn_request().  See also selinux_ip_output()
5256 		 * for similar problems. */
5257 		u32 skb_sid;
5258 		struct sk_security_struct *sksec;
5259 
5260 		sksec = sk->sk_security;
5261 		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
5262 			return NF_DROP;
5263 		/* At this point, if the returned skb peerlbl is SECSID_NULL
5264 		 * and the packet has been through at least one XFRM
5265 		 * transformation then we must be dealing with the "final"
5266 		 * form of labeled IPsec packet; since we've already applied
5267 		 * all of our access controls on this packet we can safely
5268 		 * pass the packet. */
5269 		if (skb_sid == SECSID_NULL) {
5270 			switch (family) {
5271 			case PF_INET:
5272 				if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
5273 					return NF_ACCEPT;
5274 				break;
5275 			case PF_INET6:
5276 				if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
5277 					return NF_ACCEPT;
5278 				break;
5279 			default:
5280 				return NF_DROP_ERR(-ECONNREFUSED);
5281 			}
5282 		}
5283 		if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
5284 			return NF_DROP;
5285 		secmark_perm = PACKET__SEND;
5286 	} else {
5287 		/* Locally generated packet, fetch the security label from the
5288 		 * associated socket. */
5289 		struct sk_security_struct *sksec = sk->sk_security;
5290 		peer_sid = sksec->sid;
5291 		secmark_perm = PACKET__SEND;
5292 	}
5293 
5294 	ad.type = LSM_AUDIT_DATA_NET;
5295 	ad.u.net = &net;
5296 	ad.u.net->netif = ifindex;
5297 	ad.u.net->family = family;
5298 	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5299 		return NF_DROP;
5300 
5301 	if (secmark_active)
5302 		if (avc_has_perm(peer_sid, skb->secmark,
5303 				 SECCLASS_PACKET, secmark_perm, &ad))
5304 			return NF_DROP_ERR(-ECONNREFUSED);
5305 
5306 	if (peerlbl_active) {
5307 		u32 if_sid;
5308 		u32 node_sid;
5309 
5310 		if (sel_netif_sid(dev_net(outdev), ifindex, &if_sid))
5311 			return NF_DROP;
5312 		if (avc_has_perm(peer_sid, if_sid,
5313 				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5314 			return NF_DROP_ERR(-ECONNREFUSED);
5315 
5316 		if (sel_netnode_sid(addrp, family, &node_sid))
5317 			return NF_DROP;
5318 		if (avc_has_perm(peer_sid, node_sid,
5319 				 SECCLASS_NODE, NODE__SENDTO, &ad))
5320 			return NF_DROP_ERR(-ECONNREFUSED);
5321 	}
5322 
5323 	return NF_ACCEPT;
5324 }
5325 
5326 static unsigned int selinux_ipv4_postroute(void *priv,
5327 					   struct sk_buff *skb,
5328 					   const struct nf_hook_state *state)
5329 {
5330 	return selinux_ip_postroute(skb, state->out, PF_INET);
5331 }
5332 
5333 #if IS_ENABLED(CONFIG_IPV6)
5334 static unsigned int selinux_ipv6_postroute(void *priv,
5335 					   struct sk_buff *skb,
5336 					   const struct nf_hook_state *state)
5337 {
5338 	return selinux_ip_postroute(skb, state->out, PF_INET6);
5339 }
5340 #endif	/* IPV6 */
5341 
5342 #endif	/* CONFIG_NETFILTER */
5343 
5344 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
5345 {
5346 	return selinux_nlmsg_perm(sk, skb);
5347 }
5348 
5349 static int ipc_alloc_security(struct task_struct *task,
5350 			      struct kern_ipc_perm *perm,
5351 			      u16 sclass)
5352 {
5353 	struct ipc_security_struct *isec;
5354 	u32 sid;
5355 
5356 	isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
5357 	if (!isec)
5358 		return -ENOMEM;
5359 
5360 	sid = task_sid(task);
5361 	isec->sclass = sclass;
5362 	isec->sid = sid;
5363 	perm->security = isec;
5364 
5365 	return 0;
5366 }
5367 
5368 static void ipc_free_security(struct kern_ipc_perm *perm)
5369 {
5370 	struct ipc_security_struct *isec = perm->security;
5371 	perm->security = NULL;
5372 	kfree(isec);
5373 }
5374 
5375 static int msg_msg_alloc_security(struct msg_msg *msg)
5376 {
5377 	struct msg_security_struct *msec;
5378 
5379 	msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
5380 	if (!msec)
5381 		return -ENOMEM;
5382 
5383 	msec->sid = SECINITSID_UNLABELED;
5384 	msg->security = msec;
5385 
5386 	return 0;
5387 }
5388 
5389 static void msg_msg_free_security(struct msg_msg *msg)
5390 {
5391 	struct msg_security_struct *msec = msg->security;
5392 
5393 	msg->security = NULL;
5394 	kfree(msec);
5395 }
5396 
5397 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
5398 			u32 perms)
5399 {
5400 	struct ipc_security_struct *isec;
5401 	struct common_audit_data ad;
5402 	u32 sid = current_sid();
5403 
5404 	isec = ipc_perms->security;
5405 
5406 	ad.type = LSM_AUDIT_DATA_IPC;
5407 	ad.u.ipc_id = ipc_perms->key;
5408 
5409 	return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
5410 }
5411 
5412 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
5413 {
5414 	return msg_msg_alloc_security(msg);
5415 }
5416 
5417 static void selinux_msg_msg_free_security(struct msg_msg *msg)
5418 {
5419 	msg_msg_free_security(msg);
5420 }
5421 
5422 /* message queue security operations */
5423 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
5424 {
5425 	struct ipc_security_struct *isec;
5426 	struct common_audit_data ad;
5427 	u32 sid = current_sid();
5428 	int rc;
5429 
5430 	rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
5431 	if (rc)
5432 		return rc;
5433 
5434 	isec = msq->q_perm.security;
5435 
5436 	ad.type = LSM_AUDIT_DATA_IPC;
5437 	ad.u.ipc_id = msq->q_perm.key;
5438 
5439 	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5440 			  MSGQ__CREATE, &ad);
5441 	if (rc) {
5442 		ipc_free_security(&msq->q_perm);
5443 		return rc;
5444 	}
5445 	return 0;
5446 }
5447 
5448 static void selinux_msg_queue_free_security(struct msg_queue *msq)
5449 {
5450 	ipc_free_security(&msq->q_perm);
5451 }
5452 
5453 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
5454 {
5455 	struct ipc_security_struct *isec;
5456 	struct common_audit_data ad;
5457 	u32 sid = current_sid();
5458 
5459 	isec = msq->q_perm.security;
5460 
5461 	ad.type = LSM_AUDIT_DATA_IPC;
5462 	ad.u.ipc_id = msq->q_perm.key;
5463 
5464 	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5465 			    MSGQ__ASSOCIATE, &ad);
5466 }
5467 
5468 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
5469 {
5470 	int err;
5471 	int perms;
5472 
5473 	switch (cmd) {
5474 	case IPC_INFO:
5475 	case MSG_INFO:
5476 		/* No specific object, just general system-wide information. */
5477 		return task_has_system(current, SYSTEM__IPC_INFO);
5478 	case IPC_STAT:
5479 	case MSG_STAT:
5480 		perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
5481 		break;
5482 	case IPC_SET:
5483 		perms = MSGQ__SETATTR;
5484 		break;
5485 	case IPC_RMID:
5486 		perms = MSGQ__DESTROY;
5487 		break;
5488 	default:
5489 		return 0;
5490 	}
5491 
5492 	err = ipc_has_perm(&msq->q_perm, perms);
5493 	return err;
5494 }
5495 
5496 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
5497 {
5498 	struct ipc_security_struct *isec;
5499 	struct msg_security_struct *msec;
5500 	struct common_audit_data ad;
5501 	u32 sid = current_sid();
5502 	int rc;
5503 
5504 	isec = msq->q_perm.security;
5505 	msec = msg->security;
5506 
5507 	/*
5508 	 * First time through, need to assign label to the message
5509 	 */
5510 	if (msec->sid == SECINITSID_UNLABELED) {
5511 		/*
5512 		 * Compute new sid based on current process and
5513 		 * message queue this message will be stored in
5514 		 */
5515 		rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
5516 					     NULL, &msec->sid);
5517 		if (rc)
5518 			return rc;
5519 	}
5520 
5521 	ad.type = LSM_AUDIT_DATA_IPC;
5522 	ad.u.ipc_id = msq->q_perm.key;
5523 
5524 	/* Can this process write to the queue? */
5525 	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5526 			  MSGQ__WRITE, &ad);
5527 	if (!rc)
5528 		/* Can this process send the message */
5529 		rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
5530 				  MSG__SEND, &ad);
5531 	if (!rc)
5532 		/* Can the message be put in the queue? */
5533 		rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
5534 				  MSGQ__ENQUEUE, &ad);
5535 
5536 	return rc;
5537 }
5538 
5539 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
5540 				    struct task_struct *target,
5541 				    long type, int mode)
5542 {
5543 	struct ipc_security_struct *isec;
5544 	struct msg_security_struct *msec;
5545 	struct common_audit_data ad;
5546 	u32 sid = task_sid(target);
5547 	int rc;
5548 
5549 	isec = msq->q_perm.security;
5550 	msec = msg->security;
5551 
5552 	ad.type = LSM_AUDIT_DATA_IPC;
5553 	ad.u.ipc_id = msq->q_perm.key;
5554 
5555 	rc = avc_has_perm(sid, isec->sid,
5556 			  SECCLASS_MSGQ, MSGQ__READ, &ad);
5557 	if (!rc)
5558 		rc = avc_has_perm(sid, msec->sid,
5559 				  SECCLASS_MSG, MSG__RECEIVE, &ad);
5560 	return rc;
5561 }
5562 
5563 /* Shared Memory security operations */
5564 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
5565 {
5566 	struct ipc_security_struct *isec;
5567 	struct common_audit_data ad;
5568 	u32 sid = current_sid();
5569 	int rc;
5570 
5571 	rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
5572 	if (rc)
5573 		return rc;
5574 
5575 	isec = shp->shm_perm.security;
5576 
5577 	ad.type = LSM_AUDIT_DATA_IPC;
5578 	ad.u.ipc_id = shp->shm_perm.key;
5579 
5580 	rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5581 			  SHM__CREATE, &ad);
5582 	if (rc) {
5583 		ipc_free_security(&shp->shm_perm);
5584 		return rc;
5585 	}
5586 	return 0;
5587 }
5588 
5589 static void selinux_shm_free_security(struct shmid_kernel *shp)
5590 {
5591 	ipc_free_security(&shp->shm_perm);
5592 }
5593 
5594 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
5595 {
5596 	struct ipc_security_struct *isec;
5597 	struct common_audit_data ad;
5598 	u32 sid = current_sid();
5599 
5600 	isec = shp->shm_perm.security;
5601 
5602 	ad.type = LSM_AUDIT_DATA_IPC;
5603 	ad.u.ipc_id = shp->shm_perm.key;
5604 
5605 	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5606 			    SHM__ASSOCIATE, &ad);
5607 }
5608 
5609 /* Note, at this point, shp is locked down */
5610 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
5611 {
5612 	int perms;
5613 	int err;
5614 
5615 	switch (cmd) {
5616 	case IPC_INFO:
5617 	case SHM_INFO:
5618 		/* No specific object, just general system-wide information. */
5619 		return task_has_system(current, SYSTEM__IPC_INFO);
5620 	case IPC_STAT:
5621 	case SHM_STAT:
5622 		perms = SHM__GETATTR | SHM__ASSOCIATE;
5623 		break;
5624 	case IPC_SET:
5625 		perms = SHM__SETATTR;
5626 		break;
5627 	case SHM_LOCK:
5628 	case SHM_UNLOCK:
5629 		perms = SHM__LOCK;
5630 		break;
5631 	case IPC_RMID:
5632 		perms = SHM__DESTROY;
5633 		break;
5634 	default:
5635 		return 0;
5636 	}
5637 
5638 	err = ipc_has_perm(&shp->shm_perm, perms);
5639 	return err;
5640 }
5641 
5642 static int selinux_shm_shmat(struct shmid_kernel *shp,
5643 			     char __user *shmaddr, int shmflg)
5644 {
5645 	u32 perms;
5646 
5647 	if (shmflg & SHM_RDONLY)
5648 		perms = SHM__READ;
5649 	else
5650 		perms = SHM__READ | SHM__WRITE;
5651 
5652 	return ipc_has_perm(&shp->shm_perm, perms);
5653 }
5654 
5655 /* Semaphore security operations */
5656 static int selinux_sem_alloc_security(struct sem_array *sma)
5657 {
5658 	struct ipc_security_struct *isec;
5659 	struct common_audit_data ad;
5660 	u32 sid = current_sid();
5661 	int rc;
5662 
5663 	rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
5664 	if (rc)
5665 		return rc;
5666 
5667 	isec = sma->sem_perm.security;
5668 
5669 	ad.type = LSM_AUDIT_DATA_IPC;
5670 	ad.u.ipc_id = sma->sem_perm.key;
5671 
5672 	rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5673 			  SEM__CREATE, &ad);
5674 	if (rc) {
5675 		ipc_free_security(&sma->sem_perm);
5676 		return rc;
5677 	}
5678 	return 0;
5679 }
5680 
5681 static void selinux_sem_free_security(struct sem_array *sma)
5682 {
5683 	ipc_free_security(&sma->sem_perm);
5684 }
5685 
5686 static int selinux_sem_associate(struct sem_array *sma, int semflg)
5687 {
5688 	struct ipc_security_struct *isec;
5689 	struct common_audit_data ad;
5690 	u32 sid = current_sid();
5691 
5692 	isec = sma->sem_perm.security;
5693 
5694 	ad.type = LSM_AUDIT_DATA_IPC;
5695 	ad.u.ipc_id = sma->sem_perm.key;
5696 
5697 	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5698 			    SEM__ASSOCIATE, &ad);
5699 }
5700 
5701 /* Note, at this point, sma is locked down */
5702 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5703 {
5704 	int err;
5705 	u32 perms;
5706 
5707 	switch (cmd) {
5708 	case IPC_INFO:
5709 	case SEM_INFO:
5710 		/* No specific object, just general system-wide information. */
5711 		return task_has_system(current, SYSTEM__IPC_INFO);
5712 	case GETPID:
5713 	case GETNCNT:
5714 	case GETZCNT:
5715 		perms = SEM__GETATTR;
5716 		break;
5717 	case GETVAL:
5718 	case GETALL:
5719 		perms = SEM__READ;
5720 		break;
5721 	case SETVAL:
5722 	case SETALL:
5723 		perms = SEM__WRITE;
5724 		break;
5725 	case IPC_RMID:
5726 		perms = SEM__DESTROY;
5727 		break;
5728 	case IPC_SET:
5729 		perms = SEM__SETATTR;
5730 		break;
5731 	case IPC_STAT:
5732 	case SEM_STAT:
5733 		perms = SEM__GETATTR | SEM__ASSOCIATE;
5734 		break;
5735 	default:
5736 		return 0;
5737 	}
5738 
5739 	err = ipc_has_perm(&sma->sem_perm, perms);
5740 	return err;
5741 }
5742 
5743 static int selinux_sem_semop(struct sem_array *sma,
5744 			     struct sembuf *sops, unsigned nsops, int alter)
5745 {
5746 	u32 perms;
5747 
5748 	if (alter)
5749 		perms = SEM__READ | SEM__WRITE;
5750 	else
5751 		perms = SEM__READ;
5752 
5753 	return ipc_has_perm(&sma->sem_perm, perms);
5754 }
5755 
5756 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5757 {
5758 	u32 av = 0;
5759 
5760 	av = 0;
5761 	if (flag & S_IRUGO)
5762 		av |= IPC__UNIX_READ;
5763 	if (flag & S_IWUGO)
5764 		av |= IPC__UNIX_WRITE;
5765 
5766 	if (av == 0)
5767 		return 0;
5768 
5769 	return ipc_has_perm(ipcp, av);
5770 }
5771 
5772 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5773 {
5774 	struct ipc_security_struct *isec = ipcp->security;
5775 	*secid = isec->sid;
5776 }
5777 
5778 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5779 {
5780 	if (inode)
5781 		inode_doinit_with_dentry(inode, dentry);
5782 }
5783 
5784 static int selinux_getprocattr(struct task_struct *p,
5785 			       char *name, char **value)
5786 {
5787 	const struct task_security_struct *__tsec;
5788 	u32 sid;
5789 	int error;
5790 	unsigned len;
5791 
5792 	if (current != p) {
5793 		error = current_has_perm(p, PROCESS__GETATTR);
5794 		if (error)
5795 			return error;
5796 	}
5797 
5798 	rcu_read_lock();
5799 	__tsec = __task_cred(p)->security;
5800 
5801 	if (!strcmp(name, "current"))
5802 		sid = __tsec->sid;
5803 	else if (!strcmp(name, "prev"))
5804 		sid = __tsec->osid;
5805 	else if (!strcmp(name, "exec"))
5806 		sid = __tsec->exec_sid;
5807 	else if (!strcmp(name, "fscreate"))
5808 		sid = __tsec->create_sid;
5809 	else if (!strcmp(name, "keycreate"))
5810 		sid = __tsec->keycreate_sid;
5811 	else if (!strcmp(name, "sockcreate"))
5812 		sid = __tsec->sockcreate_sid;
5813 	else
5814 		goto invalid;
5815 	rcu_read_unlock();
5816 
5817 	if (!sid)
5818 		return 0;
5819 
5820 	error = security_sid_to_context(sid, value, &len);
5821 	if (error)
5822 		return error;
5823 	return len;
5824 
5825 invalid:
5826 	rcu_read_unlock();
5827 	return -EINVAL;
5828 }
5829 
5830 static int selinux_setprocattr(struct task_struct *p,
5831 			       char *name, void *value, size_t size)
5832 {
5833 	struct task_security_struct *tsec;
5834 	struct cred *new;
5835 	u32 sid = 0, ptsid;
5836 	int error;
5837 	char *str = value;
5838 
5839 	if (current != p) {
5840 		/* SELinux only allows a process to change its own
5841 		   security attributes. */
5842 		return -EACCES;
5843 	}
5844 
5845 	/*
5846 	 * Basic control over ability to set these attributes at all.
5847 	 * current == p, but we'll pass them separately in case the
5848 	 * above restriction is ever removed.
5849 	 */
5850 	if (!strcmp(name, "exec"))
5851 		error = current_has_perm(p, PROCESS__SETEXEC);
5852 	else if (!strcmp(name, "fscreate"))
5853 		error = current_has_perm(p, PROCESS__SETFSCREATE);
5854 	else if (!strcmp(name, "keycreate"))
5855 		error = current_has_perm(p, PROCESS__SETKEYCREATE);
5856 	else if (!strcmp(name, "sockcreate"))
5857 		error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5858 	else if (!strcmp(name, "current"))
5859 		error = current_has_perm(p, PROCESS__SETCURRENT);
5860 	else
5861 		error = -EINVAL;
5862 	if (error)
5863 		return error;
5864 
5865 	/* Obtain a SID for the context, if one was specified. */
5866 	if (size && str[1] && str[1] != '\n') {
5867 		if (str[size-1] == '\n') {
5868 			str[size-1] = 0;
5869 			size--;
5870 		}
5871 		error = security_context_to_sid(value, size, &sid, GFP_KERNEL);
5872 		if (error == -EINVAL && !strcmp(name, "fscreate")) {
5873 			if (!capable(CAP_MAC_ADMIN)) {
5874 				struct audit_buffer *ab;
5875 				size_t audit_size;
5876 
5877 				/* We strip a nul only if it is at the end, otherwise the
5878 				 * context contains a nul and we should audit that */
5879 				if (str[size - 1] == '\0')
5880 					audit_size = size - 1;
5881 				else
5882 					audit_size = size;
5883 				ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
5884 				audit_log_format(ab, "op=fscreate invalid_context=");
5885 				audit_log_n_untrustedstring(ab, value, audit_size);
5886 				audit_log_end(ab);
5887 
5888 				return error;
5889 			}
5890 			error = security_context_to_sid_force(value, size,
5891 							      &sid);
5892 		}
5893 		if (error)
5894 			return error;
5895 	}
5896 
5897 	new = prepare_creds();
5898 	if (!new)
5899 		return -ENOMEM;
5900 
5901 	/* Permission checking based on the specified context is
5902 	   performed during the actual operation (execve,
5903 	   open/mkdir/...), when we know the full context of the
5904 	   operation.  See selinux_bprm_set_creds for the execve
5905 	   checks and may_create for the file creation checks. The
5906 	   operation will then fail if the context is not permitted. */
5907 	tsec = new->security;
5908 	if (!strcmp(name, "exec")) {
5909 		tsec->exec_sid = sid;
5910 	} else if (!strcmp(name, "fscreate")) {
5911 		tsec->create_sid = sid;
5912 	} else if (!strcmp(name, "keycreate")) {
5913 		error = may_create_key(sid, p);
5914 		if (error)
5915 			goto abort_change;
5916 		tsec->keycreate_sid = sid;
5917 	} else if (!strcmp(name, "sockcreate")) {
5918 		tsec->sockcreate_sid = sid;
5919 	} else if (!strcmp(name, "current")) {
5920 		error = -EINVAL;
5921 		if (sid == 0)
5922 			goto abort_change;
5923 
5924 		/* Only allow single threaded processes to change context */
5925 		error = -EPERM;
5926 		if (!current_is_single_threaded()) {
5927 			error = security_bounded_transition(tsec->sid, sid);
5928 			if (error)
5929 				goto abort_change;
5930 		}
5931 
5932 		/* Check permissions for the transition. */
5933 		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5934 				     PROCESS__DYNTRANSITION, NULL);
5935 		if (error)
5936 			goto abort_change;
5937 
5938 		/* Check for ptracing, and update the task SID if ok.
5939 		   Otherwise, leave SID unchanged and fail. */
5940 		ptsid = ptrace_parent_sid(p);
5941 		if (ptsid != 0) {
5942 			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5943 					     PROCESS__PTRACE, NULL);
5944 			if (error)
5945 				goto abort_change;
5946 		}
5947 
5948 		tsec->sid = sid;
5949 	} else {
5950 		error = -EINVAL;
5951 		goto abort_change;
5952 	}
5953 
5954 	commit_creds(new);
5955 	return size;
5956 
5957 abort_change:
5958 	abort_creds(new);
5959 	return error;
5960 }
5961 
5962 static int selinux_ismaclabel(const char *name)
5963 {
5964 	return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
5965 }
5966 
5967 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5968 {
5969 	return security_sid_to_context(secid, secdata, seclen);
5970 }
5971 
5972 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5973 {
5974 	return security_context_to_sid(secdata, seclen, secid, GFP_KERNEL);
5975 }
5976 
5977 static void selinux_release_secctx(char *secdata, u32 seclen)
5978 {
5979 	kfree(secdata);
5980 }
5981 
5982 static void selinux_inode_invalidate_secctx(struct inode *inode)
5983 {
5984 	struct inode_security_struct *isec = inode->i_security;
5985 
5986 	mutex_lock(&isec->lock);
5987 	isec->initialized = LABEL_INVALID;
5988 	mutex_unlock(&isec->lock);
5989 }
5990 
5991 /*
5992  *	called with inode->i_mutex locked
5993  */
5994 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5995 {
5996 	return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5997 }
5998 
5999 /*
6000  *	called with inode->i_mutex locked
6001  */
6002 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
6003 {
6004 	return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
6005 }
6006 
6007 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
6008 {
6009 	int len = 0;
6010 	len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
6011 						ctx, true);
6012 	if (len < 0)
6013 		return len;
6014 	*ctxlen = len;
6015 	return 0;
6016 }
6017 #ifdef CONFIG_KEYS
6018 
6019 static int selinux_key_alloc(struct key *k, const struct cred *cred,
6020 			     unsigned long flags)
6021 {
6022 	const struct task_security_struct *tsec;
6023 	struct key_security_struct *ksec;
6024 
6025 	ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
6026 	if (!ksec)
6027 		return -ENOMEM;
6028 
6029 	tsec = cred->security;
6030 	if (tsec->keycreate_sid)
6031 		ksec->sid = tsec->keycreate_sid;
6032 	else
6033 		ksec->sid = tsec->sid;
6034 
6035 	k->security = ksec;
6036 	return 0;
6037 }
6038 
6039 static void selinux_key_free(struct key *k)
6040 {
6041 	struct key_security_struct *ksec = k->security;
6042 
6043 	k->security = NULL;
6044 	kfree(ksec);
6045 }
6046 
6047 static int selinux_key_permission(key_ref_t key_ref,
6048 				  const struct cred *cred,
6049 				  unsigned perm)
6050 {
6051 	struct key *key;
6052 	struct key_security_struct *ksec;
6053 	u32 sid;
6054 
6055 	/* if no specific permissions are requested, we skip the
6056 	   permission check. No serious, additional covert channels
6057 	   appear to be created. */
6058 	if (perm == 0)
6059 		return 0;
6060 
6061 	sid = cred_sid(cred);
6062 
6063 	key = key_ref_to_ptr(key_ref);
6064 	ksec = key->security;
6065 
6066 	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
6067 }
6068 
6069 static int selinux_key_getsecurity(struct key *key, char **_buffer)
6070 {
6071 	struct key_security_struct *ksec = key->security;
6072 	char *context = NULL;
6073 	unsigned len;
6074 	int rc;
6075 
6076 	rc = security_sid_to_context(ksec->sid, &context, &len);
6077 	if (!rc)
6078 		rc = len;
6079 	*_buffer = context;
6080 	return rc;
6081 }
6082 
6083 #endif
6084 
6085 static struct security_hook_list selinux_hooks[] = {
6086 	LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
6087 	LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
6088 	LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder),
6089 	LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file),
6090 
6091 	LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check),
6092 	LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme),
6093 	LSM_HOOK_INIT(capget, selinux_capget),
6094 	LSM_HOOK_INIT(capset, selinux_capset),
6095 	LSM_HOOK_INIT(capable, selinux_capable),
6096 	LSM_HOOK_INIT(quotactl, selinux_quotactl),
6097 	LSM_HOOK_INIT(quota_on, selinux_quota_on),
6098 	LSM_HOOK_INIT(syslog, selinux_syslog),
6099 	LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory),
6100 
6101 	LSM_HOOK_INIT(netlink_send, selinux_netlink_send),
6102 
6103 	LSM_HOOK_INIT(bprm_set_creds, selinux_bprm_set_creds),
6104 	LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds),
6105 	LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds),
6106 	LSM_HOOK_INIT(bprm_secureexec, selinux_bprm_secureexec),
6107 
6108 	LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
6109 	LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
6110 	LSM_HOOK_INIT(sb_copy_data, selinux_sb_copy_data),
6111 	LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
6112 	LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
6113 	LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
6114 	LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs),
6115 	LSM_HOOK_INIT(sb_mount, selinux_mount),
6116 	LSM_HOOK_INIT(sb_umount, selinux_umount),
6117 	LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
6118 	LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
6119 	LSM_HOOK_INIT(sb_parse_opts_str, selinux_parse_opts_str),
6120 
6121 	LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
6122 	LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
6123 
6124 	LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security),
6125 	LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security),
6126 	LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security),
6127 	LSM_HOOK_INIT(inode_create, selinux_inode_create),
6128 	LSM_HOOK_INIT(inode_link, selinux_inode_link),
6129 	LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink),
6130 	LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink),
6131 	LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir),
6132 	LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir),
6133 	LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod),
6134 	LSM_HOOK_INIT(inode_rename, selinux_inode_rename),
6135 	LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink),
6136 	LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link),
6137 	LSM_HOOK_INIT(inode_permission, selinux_inode_permission),
6138 	LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr),
6139 	LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr),
6140 	LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr),
6141 	LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr),
6142 	LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr),
6143 	LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr),
6144 	LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr),
6145 	LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity),
6146 	LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
6147 	LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
6148 	LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
6149 	LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
6150 	LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
6151 
6152 	LSM_HOOK_INIT(file_permission, selinux_file_permission),
6153 	LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
6154 	LSM_HOOK_INIT(file_free_security, selinux_file_free_security),
6155 	LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl),
6156 	LSM_HOOK_INIT(mmap_file, selinux_mmap_file),
6157 	LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr),
6158 	LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect),
6159 	LSM_HOOK_INIT(file_lock, selinux_file_lock),
6160 	LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl),
6161 	LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner),
6162 	LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask),
6163 	LSM_HOOK_INIT(file_receive, selinux_file_receive),
6164 
6165 	LSM_HOOK_INIT(file_open, selinux_file_open),
6166 
6167 	LSM_HOOK_INIT(task_create, selinux_task_create),
6168 	LSM_HOOK_INIT(cred_alloc_blank, selinux_cred_alloc_blank),
6169 	LSM_HOOK_INIT(cred_free, selinux_cred_free),
6170 	LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare),
6171 	LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer),
6172 	LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as),
6173 	LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as),
6174 	LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request),
6175 	LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file),
6176 	LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid),
6177 	LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid),
6178 	LSM_HOOK_INIT(task_getsid, selinux_task_getsid),
6179 	LSM_HOOK_INIT(task_getsecid, selinux_task_getsecid),
6180 	LSM_HOOK_INIT(task_setnice, selinux_task_setnice),
6181 	LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio),
6182 	LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio),
6183 	LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit),
6184 	LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler),
6185 	LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler),
6186 	LSM_HOOK_INIT(task_movememory, selinux_task_movememory),
6187 	LSM_HOOK_INIT(task_kill, selinux_task_kill),
6188 	LSM_HOOK_INIT(task_wait, selinux_task_wait),
6189 	LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode),
6190 
6191 	LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
6192 	LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),
6193 
6194 	LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security),
6195 	LSM_HOOK_INIT(msg_msg_free_security, selinux_msg_msg_free_security),
6196 
6197 	LSM_HOOK_INIT(msg_queue_alloc_security,
6198 			selinux_msg_queue_alloc_security),
6199 	LSM_HOOK_INIT(msg_queue_free_security, selinux_msg_queue_free_security),
6200 	LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
6201 	LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
6202 	LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd),
6203 	LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv),
6204 
6205 	LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security),
6206 	LSM_HOOK_INIT(shm_free_security, selinux_shm_free_security),
6207 	LSM_HOOK_INIT(shm_associate, selinux_shm_associate),
6208 	LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl),
6209 	LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat),
6210 
6211 	LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security),
6212 	LSM_HOOK_INIT(sem_free_security, selinux_sem_free_security),
6213 	LSM_HOOK_INIT(sem_associate, selinux_sem_associate),
6214 	LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl),
6215 	LSM_HOOK_INIT(sem_semop, selinux_sem_semop),
6216 
6217 	LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate),
6218 
6219 	LSM_HOOK_INIT(getprocattr, selinux_getprocattr),
6220 	LSM_HOOK_INIT(setprocattr, selinux_setprocattr),
6221 
6222 	LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel),
6223 	LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
6224 	LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
6225 	LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
6226 	LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
6227 	LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
6228 	LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
6229 	LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),
6230 
6231 	LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect),
6232 	LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send),
6233 
6234 	LSM_HOOK_INIT(socket_create, selinux_socket_create),
6235 	LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create),
6236 	LSM_HOOK_INIT(socket_bind, selinux_socket_bind),
6237 	LSM_HOOK_INIT(socket_connect, selinux_socket_connect),
6238 	LSM_HOOK_INIT(socket_listen, selinux_socket_listen),
6239 	LSM_HOOK_INIT(socket_accept, selinux_socket_accept),
6240 	LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg),
6241 	LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg),
6242 	LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname),
6243 	LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername),
6244 	LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt),
6245 	LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt),
6246 	LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown),
6247 	LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb),
6248 	LSM_HOOK_INIT(socket_getpeersec_stream,
6249 			selinux_socket_getpeersec_stream),
6250 	LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram),
6251 	LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security),
6252 	LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security),
6253 	LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
6254 	LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
6255 	LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
6256 	LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
6257 	LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
6258 	LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
6259 	LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet),
6260 	LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc),
6261 	LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec),
6262 	LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow),
6263 	LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security),
6264 	LSM_HOOK_INIT(tun_dev_free_security, selinux_tun_dev_free_security),
6265 	LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create),
6266 	LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue),
6267 	LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach),
6268 	LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
6269 
6270 #ifdef CONFIG_SECURITY_NETWORK_XFRM
6271 	LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc),
6272 	LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone),
6273 	LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free),
6274 	LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete),
6275 	LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc),
6276 	LSM_HOOK_INIT(xfrm_state_alloc_acquire,
6277 			selinux_xfrm_state_alloc_acquire),
6278 	LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free),
6279 	LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete),
6280 	LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup),
6281 	LSM_HOOK_INIT(xfrm_state_pol_flow_match,
6282 			selinux_xfrm_state_pol_flow_match),
6283 	LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session),
6284 #endif
6285 
6286 #ifdef CONFIG_KEYS
6287 	LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
6288 	LSM_HOOK_INIT(key_free, selinux_key_free),
6289 	LSM_HOOK_INIT(key_permission, selinux_key_permission),
6290 	LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
6291 #endif
6292 
6293 #ifdef CONFIG_AUDIT
6294 	LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init),
6295 	LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known),
6296 	LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match),
6297 	LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free),
6298 #endif
6299 };
6300 
6301 static __init int selinux_init(void)
6302 {
6303 	if (!security_module_enable("selinux")) {
6304 		selinux_enabled = 0;
6305 		return 0;
6306 	}
6307 
6308 	if (!selinux_enabled) {
6309 		printk(KERN_INFO "SELinux:  Disabled at boot.\n");
6310 		return 0;
6311 	}
6312 
6313 	printk(KERN_INFO "SELinux:  Initializing.\n");
6314 
6315 	/* Set the security state for the initial task. */
6316 	cred_init_security();
6317 
6318 	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
6319 
6320 	sel_inode_cache = kmem_cache_create("selinux_inode_security",
6321 					    sizeof(struct inode_security_struct),
6322 					    0, SLAB_PANIC, NULL);
6323 	file_security_cache = kmem_cache_create("selinux_file_security",
6324 					    sizeof(struct file_security_struct),
6325 					    0, SLAB_PANIC, NULL);
6326 	avc_init();
6327 
6328 	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks));
6329 
6330 	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
6331 		panic("SELinux: Unable to register AVC netcache callback\n");
6332 
6333 	if (selinux_enforcing)
6334 		printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
6335 	else
6336 		printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
6337 
6338 	return 0;
6339 }
6340 
6341 static void delayed_superblock_init(struct super_block *sb, void *unused)
6342 {
6343 	superblock_doinit(sb, NULL);
6344 }
6345 
6346 void selinux_complete_init(void)
6347 {
6348 	printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
6349 
6350 	/* Set up any superblocks initialized prior to the policy load. */
6351 	printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
6352 	iterate_supers(delayed_superblock_init, NULL);
6353 }
6354 
6355 /* SELinux requires early initialization in order to label
6356    all processes and objects when they are created. */
6357 security_initcall(selinux_init);
6358 
6359 #if defined(CONFIG_NETFILTER)
6360 
6361 static struct nf_hook_ops selinux_nf_ops[] = {
6362 	{
6363 		.hook =		selinux_ipv4_postroute,
6364 		.pf =		NFPROTO_IPV4,
6365 		.hooknum =	NF_INET_POST_ROUTING,
6366 		.priority =	NF_IP_PRI_SELINUX_LAST,
6367 	},
6368 	{
6369 		.hook =		selinux_ipv4_forward,
6370 		.pf =		NFPROTO_IPV4,
6371 		.hooknum =	NF_INET_FORWARD,
6372 		.priority =	NF_IP_PRI_SELINUX_FIRST,
6373 	},
6374 	{
6375 		.hook =		selinux_ipv4_output,
6376 		.pf =		NFPROTO_IPV4,
6377 		.hooknum =	NF_INET_LOCAL_OUT,
6378 		.priority =	NF_IP_PRI_SELINUX_FIRST,
6379 	},
6380 #if IS_ENABLED(CONFIG_IPV6)
6381 	{
6382 		.hook =		selinux_ipv6_postroute,
6383 		.pf =		NFPROTO_IPV6,
6384 		.hooknum =	NF_INET_POST_ROUTING,
6385 		.priority =	NF_IP6_PRI_SELINUX_LAST,
6386 	},
6387 	{
6388 		.hook =		selinux_ipv6_forward,
6389 		.pf =		NFPROTO_IPV6,
6390 		.hooknum =	NF_INET_FORWARD,
6391 		.priority =	NF_IP6_PRI_SELINUX_FIRST,
6392 	},
6393 	{
6394 		.hook =		selinux_ipv6_output,
6395 		.pf =		NFPROTO_IPV6,
6396 		.hooknum =	NF_INET_LOCAL_OUT,
6397 		.priority =	NF_IP6_PRI_SELINUX_FIRST,
6398 	},
6399 #endif	/* IPV6 */
6400 };
6401 
6402 static int __init selinux_nf_ip_init(void)
6403 {
6404 	int err;
6405 
6406 	if (!selinux_enabled)
6407 		return 0;
6408 
6409 	printk(KERN_DEBUG "SELinux:  Registering netfilter hooks\n");
6410 
6411 	err = nf_register_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
6412 	if (err)
6413 		panic("SELinux: nf_register_hooks: error %d\n", err);
6414 
6415 	return 0;
6416 }
6417 
6418 __initcall(selinux_nf_ip_init);
6419 
6420 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
6421 static void selinux_nf_ip_exit(void)
6422 {
6423 	printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
6424 
6425 	nf_unregister_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
6426 }
6427 #endif
6428 
6429 #else /* CONFIG_NETFILTER */
6430 
6431 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
6432 #define selinux_nf_ip_exit()
6433 #endif
6434 
6435 #endif /* CONFIG_NETFILTER */
6436 
6437 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
6438 static int selinux_disabled;
6439 
6440 int selinux_disable(void)
6441 {
6442 	if (ss_initialized) {
6443 		/* Not permitted after initial policy load. */
6444 		return -EINVAL;
6445 	}
6446 
6447 	if (selinux_disabled) {
6448 		/* Only do this once. */
6449 		return -EINVAL;
6450 	}
6451 
6452 	printk(KERN_INFO "SELinux:  Disabled at runtime.\n");
6453 
6454 	selinux_disabled = 1;
6455 	selinux_enabled = 0;
6456 
6457 	security_delete_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks));
6458 
6459 	/* Try to destroy the avc node cache */
6460 	avc_disable();
6461 
6462 	/* Unregister netfilter hooks. */
6463 	selinux_nf_ip_exit();
6464 
6465 	/* Unregister selinuxfs. */
6466 	exit_sel_fs();
6467 
6468 	return 0;
6469 }
6470 #endif
6471