xref: /linux/security/selinux/hooks.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
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/security.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/net_namespace.h>
56 #include <net/netlabel.h>
57 #include <linux/uaccess.h>
58 #include <asm/ioctls.h>
59 #include <linux/atomic.h>
60 #include <linux/bitops.h>
61 #include <linux/interrupt.h>
62 #include <linux/netdevice.h>	/* for network interface checks */
63 #include <linux/netlink.h>
64 #include <linux/tcp.h>
65 #include <linux/udp.h>
66 #include <linux/dccp.h>
67 #include <linux/quota.h>
68 #include <linux/un.h>		/* for Unix socket types */
69 #include <net/af_unix.h>	/* for Unix socket types */
70 #include <linux/parser.h>
71 #include <linux/nfs_mount.h>
72 #include <net/ipv6.h>
73 #include <linux/hugetlb.h>
74 #include <linux/personality.h>
75 #include <linux/audit.h>
76 #include <linux/string.h>
77 #include <linux/selinux.h>
78 #include <linux/mutex.h>
79 #include <linux/posix-timers.h>
80 #include <linux/syslog.h>
81 #include <linux/user_namespace.h>
82 #include <linux/export.h>
83 #include <linux/msg.h>
84 #include <linux/shm.h>
85 
86 #include "avc.h"
87 #include "objsec.h"
88 #include "netif.h"
89 #include "netnode.h"
90 #include "netport.h"
91 #include "xfrm.h"
92 #include "netlabel.h"
93 #include "audit.h"
94 #include "avc_ss.h"
95 
96 #define NUM_SEL_MNT_OPTS 5
97 
98 extern struct security_operations *security_ops;
99 
100 /* SECMARK reference count */
101 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
102 
103 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
104 int selinux_enforcing;
105 
106 static int __init enforcing_setup(char *str)
107 {
108 	unsigned long enforcing;
109 	if (!strict_strtoul(str, 0, &enforcing))
110 		selinux_enforcing = enforcing ? 1 : 0;
111 	return 1;
112 }
113 __setup("enforcing=", enforcing_setup);
114 #endif
115 
116 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
117 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
118 
119 static int __init selinux_enabled_setup(char *str)
120 {
121 	unsigned long enabled;
122 	if (!strict_strtoul(str, 0, &enabled))
123 		selinux_enabled = enabled ? 1 : 0;
124 	return 1;
125 }
126 __setup("selinux=", selinux_enabled_setup);
127 #else
128 int selinux_enabled = 1;
129 #endif
130 
131 static struct kmem_cache *sel_inode_cache;
132 
133 /**
134  * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
135  *
136  * Description:
137  * This function checks the SECMARK reference counter to see if any SECMARK
138  * targets are currently configured, if the reference counter is greater than
139  * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
140  * enabled, false (0) if SECMARK is disabled.
141  *
142  */
143 static int selinux_secmark_enabled(void)
144 {
145 	return (atomic_read(&selinux_secmark_refcount) > 0);
146 }
147 
148 /*
149  * initialise the security for the init task
150  */
151 static void cred_init_security(void)
152 {
153 	struct cred *cred = (struct cred *) current->real_cred;
154 	struct task_security_struct *tsec;
155 
156 	tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
157 	if (!tsec)
158 		panic("SELinux:  Failed to initialize initial task.\n");
159 
160 	tsec->osid = tsec->sid = SECINITSID_KERNEL;
161 	cred->security = tsec;
162 }
163 
164 /*
165  * get the security ID of a set of credentials
166  */
167 static inline u32 cred_sid(const struct cred *cred)
168 {
169 	const struct task_security_struct *tsec;
170 
171 	tsec = cred->security;
172 	return tsec->sid;
173 }
174 
175 /*
176  * get the objective security ID of a task
177  */
178 static inline u32 task_sid(const struct task_struct *task)
179 {
180 	u32 sid;
181 
182 	rcu_read_lock();
183 	sid = cred_sid(__task_cred(task));
184 	rcu_read_unlock();
185 	return sid;
186 }
187 
188 /*
189  * get the subjective security ID of the current task
190  */
191 static inline u32 current_sid(void)
192 {
193 	const struct task_security_struct *tsec = current_security();
194 
195 	return tsec->sid;
196 }
197 
198 /* Allocate and free functions for each kind of security blob. */
199 
200 static int inode_alloc_security(struct inode *inode)
201 {
202 	struct inode_security_struct *isec;
203 	u32 sid = current_sid();
204 
205 	isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
206 	if (!isec)
207 		return -ENOMEM;
208 
209 	mutex_init(&isec->lock);
210 	INIT_LIST_HEAD(&isec->list);
211 	isec->inode = inode;
212 	isec->sid = SECINITSID_UNLABELED;
213 	isec->sclass = SECCLASS_FILE;
214 	isec->task_sid = sid;
215 	inode->i_security = isec;
216 
217 	return 0;
218 }
219 
220 static void inode_free_security(struct inode *inode)
221 {
222 	struct inode_security_struct *isec = inode->i_security;
223 	struct superblock_security_struct *sbsec = inode->i_sb->s_security;
224 
225 	spin_lock(&sbsec->isec_lock);
226 	if (!list_empty(&isec->list))
227 		list_del_init(&isec->list);
228 	spin_unlock(&sbsec->isec_lock);
229 
230 	inode->i_security = NULL;
231 	kmem_cache_free(sel_inode_cache, isec);
232 }
233 
234 static int file_alloc_security(struct file *file)
235 {
236 	struct file_security_struct *fsec;
237 	u32 sid = current_sid();
238 
239 	fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
240 	if (!fsec)
241 		return -ENOMEM;
242 
243 	fsec->sid = sid;
244 	fsec->fown_sid = sid;
245 	file->f_security = fsec;
246 
247 	return 0;
248 }
249 
250 static void file_free_security(struct file *file)
251 {
252 	struct file_security_struct *fsec = file->f_security;
253 	file->f_security = NULL;
254 	kfree(fsec);
255 }
256 
257 static int superblock_alloc_security(struct super_block *sb)
258 {
259 	struct superblock_security_struct *sbsec;
260 
261 	sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
262 	if (!sbsec)
263 		return -ENOMEM;
264 
265 	mutex_init(&sbsec->lock);
266 	INIT_LIST_HEAD(&sbsec->isec_head);
267 	spin_lock_init(&sbsec->isec_lock);
268 	sbsec->sb = sb;
269 	sbsec->sid = SECINITSID_UNLABELED;
270 	sbsec->def_sid = SECINITSID_FILE;
271 	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
272 	sb->s_security = sbsec;
273 
274 	return 0;
275 }
276 
277 static void superblock_free_security(struct super_block *sb)
278 {
279 	struct superblock_security_struct *sbsec = sb->s_security;
280 	sb->s_security = NULL;
281 	kfree(sbsec);
282 }
283 
284 /* The file system's label must be initialized prior to use. */
285 
286 static const char *labeling_behaviors[6] = {
287 	"uses xattr",
288 	"uses transition SIDs",
289 	"uses task SIDs",
290 	"uses genfs_contexts",
291 	"not configured for labeling",
292 	"uses mountpoint labeling",
293 };
294 
295 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
296 
297 static inline int inode_doinit(struct inode *inode)
298 {
299 	return inode_doinit_with_dentry(inode, NULL);
300 }
301 
302 enum {
303 	Opt_error = -1,
304 	Opt_context = 1,
305 	Opt_fscontext = 2,
306 	Opt_defcontext = 3,
307 	Opt_rootcontext = 4,
308 	Opt_labelsupport = 5,
309 };
310 
311 static const match_table_t tokens = {
312 	{Opt_context, CONTEXT_STR "%s"},
313 	{Opt_fscontext, FSCONTEXT_STR "%s"},
314 	{Opt_defcontext, DEFCONTEXT_STR "%s"},
315 	{Opt_rootcontext, ROOTCONTEXT_STR "%s"},
316 	{Opt_labelsupport, LABELSUPP_STR},
317 	{Opt_error, NULL},
318 };
319 
320 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
321 
322 static int may_context_mount_sb_relabel(u32 sid,
323 			struct superblock_security_struct *sbsec,
324 			const struct cred *cred)
325 {
326 	const struct task_security_struct *tsec = cred->security;
327 	int rc;
328 
329 	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
330 			  FILESYSTEM__RELABELFROM, NULL);
331 	if (rc)
332 		return rc;
333 
334 	rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
335 			  FILESYSTEM__RELABELTO, NULL);
336 	return rc;
337 }
338 
339 static int may_context_mount_inode_relabel(u32 sid,
340 			struct superblock_security_struct *sbsec,
341 			const struct cred *cred)
342 {
343 	const struct task_security_struct *tsec = cred->security;
344 	int rc;
345 	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
346 			  FILESYSTEM__RELABELFROM, NULL);
347 	if (rc)
348 		return rc;
349 
350 	rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
351 			  FILESYSTEM__ASSOCIATE, NULL);
352 	return rc;
353 }
354 
355 static int sb_finish_set_opts(struct super_block *sb)
356 {
357 	struct superblock_security_struct *sbsec = sb->s_security;
358 	struct dentry *root = sb->s_root;
359 	struct inode *root_inode = root->d_inode;
360 	int rc = 0;
361 
362 	if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
363 		/* Make sure that the xattr handler exists and that no
364 		   error other than -ENODATA is returned by getxattr on
365 		   the root directory.  -ENODATA is ok, as this may be
366 		   the first boot of the SELinux kernel before we have
367 		   assigned xattr values to the filesystem. */
368 		if (!root_inode->i_op->getxattr) {
369 			printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
370 			       "xattr support\n", sb->s_id, sb->s_type->name);
371 			rc = -EOPNOTSUPP;
372 			goto out;
373 		}
374 		rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
375 		if (rc < 0 && rc != -ENODATA) {
376 			if (rc == -EOPNOTSUPP)
377 				printk(KERN_WARNING "SELinux: (dev %s, type "
378 				       "%s) has no security xattr handler\n",
379 				       sb->s_id, sb->s_type->name);
380 			else
381 				printk(KERN_WARNING "SELinux: (dev %s, type "
382 				       "%s) getxattr errno %d\n", sb->s_id,
383 				       sb->s_type->name, -rc);
384 			goto out;
385 		}
386 	}
387 
388 	sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
389 
390 	if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
391 		printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
392 		       sb->s_id, sb->s_type->name);
393 	else
394 		printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
395 		       sb->s_id, sb->s_type->name,
396 		       labeling_behaviors[sbsec->behavior-1]);
397 
398 	if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
399 	    sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
400 	    sbsec->behavior == SECURITY_FS_USE_NONE ||
401 	    sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
402 		sbsec->flags &= ~SE_SBLABELSUPP;
403 
404 	/* Special handling for sysfs. Is genfs but also has setxattr handler*/
405 	if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
406 		sbsec->flags |= SE_SBLABELSUPP;
407 
408 	/* Initialize the root inode. */
409 	rc = inode_doinit_with_dentry(root_inode, root);
410 
411 	/* Initialize any other inodes associated with the superblock, e.g.
412 	   inodes created prior to initial policy load or inodes created
413 	   during get_sb by a pseudo filesystem that directly
414 	   populates itself. */
415 	spin_lock(&sbsec->isec_lock);
416 next_inode:
417 	if (!list_empty(&sbsec->isec_head)) {
418 		struct inode_security_struct *isec =
419 				list_entry(sbsec->isec_head.next,
420 					   struct inode_security_struct, list);
421 		struct inode *inode = isec->inode;
422 		spin_unlock(&sbsec->isec_lock);
423 		inode = igrab(inode);
424 		if (inode) {
425 			if (!IS_PRIVATE(inode))
426 				inode_doinit(inode);
427 			iput(inode);
428 		}
429 		spin_lock(&sbsec->isec_lock);
430 		list_del_init(&isec->list);
431 		goto next_inode;
432 	}
433 	spin_unlock(&sbsec->isec_lock);
434 out:
435 	return rc;
436 }
437 
438 /*
439  * This function should allow an FS to ask what it's mount security
440  * options were so it can use those later for submounts, displaying
441  * mount options, or whatever.
442  */
443 static int selinux_get_mnt_opts(const struct super_block *sb,
444 				struct security_mnt_opts *opts)
445 {
446 	int rc = 0, i;
447 	struct superblock_security_struct *sbsec = sb->s_security;
448 	char *context = NULL;
449 	u32 len;
450 	char tmp;
451 
452 	security_init_mnt_opts(opts);
453 
454 	if (!(sbsec->flags & SE_SBINITIALIZED))
455 		return -EINVAL;
456 
457 	if (!ss_initialized)
458 		return -EINVAL;
459 
460 	tmp = sbsec->flags & SE_MNTMASK;
461 	/* count the number of mount options for this sb */
462 	for (i = 0; i < 8; i++) {
463 		if (tmp & 0x01)
464 			opts->num_mnt_opts++;
465 		tmp >>= 1;
466 	}
467 	/* Check if the Label support flag is set */
468 	if (sbsec->flags & SE_SBLABELSUPP)
469 		opts->num_mnt_opts++;
470 
471 	opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
472 	if (!opts->mnt_opts) {
473 		rc = -ENOMEM;
474 		goto out_free;
475 	}
476 
477 	opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
478 	if (!opts->mnt_opts_flags) {
479 		rc = -ENOMEM;
480 		goto out_free;
481 	}
482 
483 	i = 0;
484 	if (sbsec->flags & FSCONTEXT_MNT) {
485 		rc = security_sid_to_context(sbsec->sid, &context, &len);
486 		if (rc)
487 			goto out_free;
488 		opts->mnt_opts[i] = context;
489 		opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
490 	}
491 	if (sbsec->flags & CONTEXT_MNT) {
492 		rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
493 		if (rc)
494 			goto out_free;
495 		opts->mnt_opts[i] = context;
496 		opts->mnt_opts_flags[i++] = CONTEXT_MNT;
497 	}
498 	if (sbsec->flags & DEFCONTEXT_MNT) {
499 		rc = security_sid_to_context(sbsec->def_sid, &context, &len);
500 		if (rc)
501 			goto out_free;
502 		opts->mnt_opts[i] = context;
503 		opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
504 	}
505 	if (sbsec->flags & ROOTCONTEXT_MNT) {
506 		struct inode *root = sbsec->sb->s_root->d_inode;
507 		struct inode_security_struct *isec = root->i_security;
508 
509 		rc = security_sid_to_context(isec->sid, &context, &len);
510 		if (rc)
511 			goto out_free;
512 		opts->mnt_opts[i] = context;
513 		opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
514 	}
515 	if (sbsec->flags & SE_SBLABELSUPP) {
516 		opts->mnt_opts[i] = NULL;
517 		opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
518 	}
519 
520 	BUG_ON(i != opts->num_mnt_opts);
521 
522 	return 0;
523 
524 out_free:
525 	security_free_mnt_opts(opts);
526 	return rc;
527 }
528 
529 static int bad_option(struct superblock_security_struct *sbsec, char flag,
530 		      u32 old_sid, u32 new_sid)
531 {
532 	char mnt_flags = sbsec->flags & SE_MNTMASK;
533 
534 	/* check if the old mount command had the same options */
535 	if (sbsec->flags & SE_SBINITIALIZED)
536 		if (!(sbsec->flags & flag) ||
537 		    (old_sid != new_sid))
538 			return 1;
539 
540 	/* check if we were passed the same options twice,
541 	 * aka someone passed context=a,context=b
542 	 */
543 	if (!(sbsec->flags & SE_SBINITIALIZED))
544 		if (mnt_flags & flag)
545 			return 1;
546 	return 0;
547 }
548 
549 /*
550  * Allow filesystems with binary mount data to explicitly set mount point
551  * labeling information.
552  */
553 static int selinux_set_mnt_opts(struct super_block *sb,
554 				struct security_mnt_opts *opts)
555 {
556 	const struct cred *cred = current_cred();
557 	int rc = 0, i;
558 	struct superblock_security_struct *sbsec = sb->s_security;
559 	const char *name = sb->s_type->name;
560 	struct inode *inode = sbsec->sb->s_root->d_inode;
561 	struct inode_security_struct *root_isec = inode->i_security;
562 	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
563 	u32 defcontext_sid = 0;
564 	char **mount_options = opts->mnt_opts;
565 	int *flags = opts->mnt_opts_flags;
566 	int num_opts = opts->num_mnt_opts;
567 
568 	mutex_lock(&sbsec->lock);
569 
570 	if (!ss_initialized) {
571 		if (!num_opts) {
572 			/* Defer initialization until selinux_complete_init,
573 			   after the initial policy is loaded and the security
574 			   server is ready to handle calls. */
575 			goto out;
576 		}
577 		rc = -EINVAL;
578 		printk(KERN_WARNING "SELinux: Unable to set superblock options "
579 			"before the security server is initialized\n");
580 		goto out;
581 	}
582 
583 	/*
584 	 * Binary mount data FS will come through this function twice.  Once
585 	 * from an explicit call and once from the generic calls from the vfs.
586 	 * Since the generic VFS calls will not contain any security mount data
587 	 * we need to skip the double mount verification.
588 	 *
589 	 * This does open a hole in which we will not notice if the first
590 	 * mount using this sb set explict options and a second mount using
591 	 * this sb does not set any security options.  (The first options
592 	 * will be used for both mounts)
593 	 */
594 	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
595 	    && (num_opts == 0))
596 		goto out;
597 
598 	/*
599 	 * parse the mount options, check if they are valid sids.
600 	 * also check if someone is trying to mount the same sb more
601 	 * than once with different security options.
602 	 */
603 	for (i = 0; i < num_opts; i++) {
604 		u32 sid;
605 
606 		if (flags[i] == SE_SBLABELSUPP)
607 			continue;
608 		rc = security_context_to_sid(mount_options[i],
609 					     strlen(mount_options[i]), &sid);
610 		if (rc) {
611 			printk(KERN_WARNING "SELinux: security_context_to_sid"
612 			       "(%s) failed for (dev %s, type %s) errno=%d\n",
613 			       mount_options[i], sb->s_id, name, rc);
614 			goto out;
615 		}
616 		switch (flags[i]) {
617 		case FSCONTEXT_MNT:
618 			fscontext_sid = sid;
619 
620 			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
621 					fscontext_sid))
622 				goto out_double_mount;
623 
624 			sbsec->flags |= FSCONTEXT_MNT;
625 			break;
626 		case CONTEXT_MNT:
627 			context_sid = sid;
628 
629 			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
630 					context_sid))
631 				goto out_double_mount;
632 
633 			sbsec->flags |= CONTEXT_MNT;
634 			break;
635 		case ROOTCONTEXT_MNT:
636 			rootcontext_sid = sid;
637 
638 			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
639 					rootcontext_sid))
640 				goto out_double_mount;
641 
642 			sbsec->flags |= ROOTCONTEXT_MNT;
643 
644 			break;
645 		case DEFCONTEXT_MNT:
646 			defcontext_sid = sid;
647 
648 			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
649 					defcontext_sid))
650 				goto out_double_mount;
651 
652 			sbsec->flags |= DEFCONTEXT_MNT;
653 
654 			break;
655 		default:
656 			rc = -EINVAL;
657 			goto out;
658 		}
659 	}
660 
661 	if (sbsec->flags & SE_SBINITIALIZED) {
662 		/* previously mounted with options, but not on this attempt? */
663 		if ((sbsec->flags & SE_MNTMASK) && !num_opts)
664 			goto out_double_mount;
665 		rc = 0;
666 		goto out;
667 	}
668 
669 	if (strcmp(sb->s_type->name, "proc") == 0)
670 		sbsec->flags |= SE_SBPROC;
671 
672 	/* Determine the labeling behavior to use for this filesystem type. */
673 	rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
674 	if (rc) {
675 		printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
676 		       __func__, sb->s_type->name, rc);
677 		goto out;
678 	}
679 
680 	/* sets the context of the superblock for the fs being mounted. */
681 	if (fscontext_sid) {
682 		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
683 		if (rc)
684 			goto out;
685 
686 		sbsec->sid = fscontext_sid;
687 	}
688 
689 	/*
690 	 * Switch to using mount point labeling behavior.
691 	 * sets the label used on all file below the mountpoint, and will set
692 	 * the superblock context if not already set.
693 	 */
694 	if (context_sid) {
695 		if (!fscontext_sid) {
696 			rc = may_context_mount_sb_relabel(context_sid, sbsec,
697 							  cred);
698 			if (rc)
699 				goto out;
700 			sbsec->sid = context_sid;
701 		} else {
702 			rc = may_context_mount_inode_relabel(context_sid, sbsec,
703 							     cred);
704 			if (rc)
705 				goto out;
706 		}
707 		if (!rootcontext_sid)
708 			rootcontext_sid = context_sid;
709 
710 		sbsec->mntpoint_sid = context_sid;
711 		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
712 	}
713 
714 	if (rootcontext_sid) {
715 		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
716 						     cred);
717 		if (rc)
718 			goto out;
719 
720 		root_isec->sid = rootcontext_sid;
721 		root_isec->initialized = 1;
722 	}
723 
724 	if (defcontext_sid) {
725 		if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
726 			rc = -EINVAL;
727 			printk(KERN_WARNING "SELinux: defcontext option is "
728 			       "invalid for this filesystem type\n");
729 			goto out;
730 		}
731 
732 		if (defcontext_sid != sbsec->def_sid) {
733 			rc = may_context_mount_inode_relabel(defcontext_sid,
734 							     sbsec, cred);
735 			if (rc)
736 				goto out;
737 		}
738 
739 		sbsec->def_sid = defcontext_sid;
740 	}
741 
742 	rc = sb_finish_set_opts(sb);
743 out:
744 	mutex_unlock(&sbsec->lock);
745 	return rc;
746 out_double_mount:
747 	rc = -EINVAL;
748 	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
749 	       "security settings for (dev %s, type %s)\n", sb->s_id, name);
750 	goto out;
751 }
752 
753 static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
754 					struct super_block *newsb)
755 {
756 	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
757 	struct superblock_security_struct *newsbsec = newsb->s_security;
758 
759 	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
760 	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
761 	int set_rootcontext =	(oldsbsec->flags & ROOTCONTEXT_MNT);
762 
763 	/*
764 	 * if the parent was able to be mounted it clearly had no special lsm
765 	 * mount options.  thus we can safely deal with this superblock later
766 	 */
767 	if (!ss_initialized)
768 		return;
769 
770 	/* how can we clone if the old one wasn't set up?? */
771 	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
772 
773 	/* if fs is reusing a sb, just let its options stand... */
774 	if (newsbsec->flags & SE_SBINITIALIZED)
775 		return;
776 
777 	mutex_lock(&newsbsec->lock);
778 
779 	newsbsec->flags = oldsbsec->flags;
780 
781 	newsbsec->sid = oldsbsec->sid;
782 	newsbsec->def_sid = oldsbsec->def_sid;
783 	newsbsec->behavior = oldsbsec->behavior;
784 
785 	if (set_context) {
786 		u32 sid = oldsbsec->mntpoint_sid;
787 
788 		if (!set_fscontext)
789 			newsbsec->sid = sid;
790 		if (!set_rootcontext) {
791 			struct inode *newinode = newsb->s_root->d_inode;
792 			struct inode_security_struct *newisec = newinode->i_security;
793 			newisec->sid = sid;
794 		}
795 		newsbsec->mntpoint_sid = sid;
796 	}
797 	if (set_rootcontext) {
798 		const struct inode *oldinode = oldsb->s_root->d_inode;
799 		const struct inode_security_struct *oldisec = oldinode->i_security;
800 		struct inode *newinode = newsb->s_root->d_inode;
801 		struct inode_security_struct *newisec = newinode->i_security;
802 
803 		newisec->sid = oldisec->sid;
804 	}
805 
806 	sb_finish_set_opts(newsb);
807 	mutex_unlock(&newsbsec->lock);
808 }
809 
810 static int selinux_parse_opts_str(char *options,
811 				  struct security_mnt_opts *opts)
812 {
813 	char *p;
814 	char *context = NULL, *defcontext = NULL;
815 	char *fscontext = NULL, *rootcontext = NULL;
816 	int rc, num_mnt_opts = 0;
817 
818 	opts->num_mnt_opts = 0;
819 
820 	/* Standard string-based options. */
821 	while ((p = strsep(&options, "|")) != NULL) {
822 		int token;
823 		substring_t args[MAX_OPT_ARGS];
824 
825 		if (!*p)
826 			continue;
827 
828 		token = match_token(p, tokens, args);
829 
830 		switch (token) {
831 		case Opt_context:
832 			if (context || defcontext) {
833 				rc = -EINVAL;
834 				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
835 				goto out_err;
836 			}
837 			context = match_strdup(&args[0]);
838 			if (!context) {
839 				rc = -ENOMEM;
840 				goto out_err;
841 			}
842 			break;
843 
844 		case Opt_fscontext:
845 			if (fscontext) {
846 				rc = -EINVAL;
847 				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
848 				goto out_err;
849 			}
850 			fscontext = match_strdup(&args[0]);
851 			if (!fscontext) {
852 				rc = -ENOMEM;
853 				goto out_err;
854 			}
855 			break;
856 
857 		case Opt_rootcontext:
858 			if (rootcontext) {
859 				rc = -EINVAL;
860 				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
861 				goto out_err;
862 			}
863 			rootcontext = match_strdup(&args[0]);
864 			if (!rootcontext) {
865 				rc = -ENOMEM;
866 				goto out_err;
867 			}
868 			break;
869 
870 		case Opt_defcontext:
871 			if (context || defcontext) {
872 				rc = -EINVAL;
873 				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
874 				goto out_err;
875 			}
876 			defcontext = match_strdup(&args[0]);
877 			if (!defcontext) {
878 				rc = -ENOMEM;
879 				goto out_err;
880 			}
881 			break;
882 		case Opt_labelsupport:
883 			break;
884 		default:
885 			rc = -EINVAL;
886 			printk(KERN_WARNING "SELinux:  unknown mount option\n");
887 			goto out_err;
888 
889 		}
890 	}
891 
892 	rc = -ENOMEM;
893 	opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
894 	if (!opts->mnt_opts)
895 		goto out_err;
896 
897 	opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
898 	if (!opts->mnt_opts_flags) {
899 		kfree(opts->mnt_opts);
900 		goto out_err;
901 	}
902 
903 	if (fscontext) {
904 		opts->mnt_opts[num_mnt_opts] = fscontext;
905 		opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
906 	}
907 	if (context) {
908 		opts->mnt_opts[num_mnt_opts] = context;
909 		opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
910 	}
911 	if (rootcontext) {
912 		opts->mnt_opts[num_mnt_opts] = rootcontext;
913 		opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
914 	}
915 	if (defcontext) {
916 		opts->mnt_opts[num_mnt_opts] = defcontext;
917 		opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
918 	}
919 
920 	opts->num_mnt_opts = num_mnt_opts;
921 	return 0;
922 
923 out_err:
924 	kfree(context);
925 	kfree(defcontext);
926 	kfree(fscontext);
927 	kfree(rootcontext);
928 	return rc;
929 }
930 /*
931  * string mount options parsing and call set the sbsec
932  */
933 static int superblock_doinit(struct super_block *sb, void *data)
934 {
935 	int rc = 0;
936 	char *options = data;
937 	struct security_mnt_opts opts;
938 
939 	security_init_mnt_opts(&opts);
940 
941 	if (!data)
942 		goto out;
943 
944 	BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
945 
946 	rc = selinux_parse_opts_str(options, &opts);
947 	if (rc)
948 		goto out_err;
949 
950 out:
951 	rc = selinux_set_mnt_opts(sb, &opts);
952 
953 out_err:
954 	security_free_mnt_opts(&opts);
955 	return rc;
956 }
957 
958 static void selinux_write_opts(struct seq_file *m,
959 			       struct security_mnt_opts *opts)
960 {
961 	int i;
962 	char *prefix;
963 
964 	for (i = 0; i < opts->num_mnt_opts; i++) {
965 		char *has_comma;
966 
967 		if (opts->mnt_opts[i])
968 			has_comma = strchr(opts->mnt_opts[i], ',');
969 		else
970 			has_comma = NULL;
971 
972 		switch (opts->mnt_opts_flags[i]) {
973 		case CONTEXT_MNT:
974 			prefix = CONTEXT_STR;
975 			break;
976 		case FSCONTEXT_MNT:
977 			prefix = FSCONTEXT_STR;
978 			break;
979 		case ROOTCONTEXT_MNT:
980 			prefix = ROOTCONTEXT_STR;
981 			break;
982 		case DEFCONTEXT_MNT:
983 			prefix = DEFCONTEXT_STR;
984 			break;
985 		case SE_SBLABELSUPP:
986 			seq_putc(m, ',');
987 			seq_puts(m, LABELSUPP_STR);
988 			continue;
989 		default:
990 			BUG();
991 			return;
992 		};
993 		/* we need a comma before each option */
994 		seq_putc(m, ',');
995 		seq_puts(m, prefix);
996 		if (has_comma)
997 			seq_putc(m, '\"');
998 		seq_puts(m, opts->mnt_opts[i]);
999 		if (has_comma)
1000 			seq_putc(m, '\"');
1001 	}
1002 }
1003 
1004 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1005 {
1006 	struct security_mnt_opts opts;
1007 	int rc;
1008 
1009 	rc = selinux_get_mnt_opts(sb, &opts);
1010 	if (rc) {
1011 		/* before policy load we may get EINVAL, don't show anything */
1012 		if (rc == -EINVAL)
1013 			rc = 0;
1014 		return rc;
1015 	}
1016 
1017 	selinux_write_opts(m, &opts);
1018 
1019 	security_free_mnt_opts(&opts);
1020 
1021 	return rc;
1022 }
1023 
1024 static inline u16 inode_mode_to_security_class(umode_t mode)
1025 {
1026 	switch (mode & S_IFMT) {
1027 	case S_IFSOCK:
1028 		return SECCLASS_SOCK_FILE;
1029 	case S_IFLNK:
1030 		return SECCLASS_LNK_FILE;
1031 	case S_IFREG:
1032 		return SECCLASS_FILE;
1033 	case S_IFBLK:
1034 		return SECCLASS_BLK_FILE;
1035 	case S_IFDIR:
1036 		return SECCLASS_DIR;
1037 	case S_IFCHR:
1038 		return SECCLASS_CHR_FILE;
1039 	case S_IFIFO:
1040 		return SECCLASS_FIFO_FILE;
1041 
1042 	}
1043 
1044 	return SECCLASS_FILE;
1045 }
1046 
1047 static inline int default_protocol_stream(int protocol)
1048 {
1049 	return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1050 }
1051 
1052 static inline int default_protocol_dgram(int protocol)
1053 {
1054 	return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1055 }
1056 
1057 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1058 {
1059 	switch (family) {
1060 	case PF_UNIX:
1061 		switch (type) {
1062 		case SOCK_STREAM:
1063 		case SOCK_SEQPACKET:
1064 			return SECCLASS_UNIX_STREAM_SOCKET;
1065 		case SOCK_DGRAM:
1066 			return SECCLASS_UNIX_DGRAM_SOCKET;
1067 		}
1068 		break;
1069 	case PF_INET:
1070 	case PF_INET6:
1071 		switch (type) {
1072 		case SOCK_STREAM:
1073 			if (default_protocol_stream(protocol))
1074 				return SECCLASS_TCP_SOCKET;
1075 			else
1076 				return SECCLASS_RAWIP_SOCKET;
1077 		case SOCK_DGRAM:
1078 			if (default_protocol_dgram(protocol))
1079 				return SECCLASS_UDP_SOCKET;
1080 			else
1081 				return SECCLASS_RAWIP_SOCKET;
1082 		case SOCK_DCCP:
1083 			return SECCLASS_DCCP_SOCKET;
1084 		default:
1085 			return SECCLASS_RAWIP_SOCKET;
1086 		}
1087 		break;
1088 	case PF_NETLINK:
1089 		switch (protocol) {
1090 		case NETLINK_ROUTE:
1091 			return SECCLASS_NETLINK_ROUTE_SOCKET;
1092 		case NETLINK_FIREWALL:
1093 			return SECCLASS_NETLINK_FIREWALL_SOCKET;
1094 		case NETLINK_SOCK_DIAG:
1095 			return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1096 		case NETLINK_NFLOG:
1097 			return SECCLASS_NETLINK_NFLOG_SOCKET;
1098 		case NETLINK_XFRM:
1099 			return SECCLASS_NETLINK_XFRM_SOCKET;
1100 		case NETLINK_SELINUX:
1101 			return SECCLASS_NETLINK_SELINUX_SOCKET;
1102 		case NETLINK_AUDIT:
1103 			return SECCLASS_NETLINK_AUDIT_SOCKET;
1104 		case NETLINK_IP6_FW:
1105 			return SECCLASS_NETLINK_IP6FW_SOCKET;
1106 		case NETLINK_DNRTMSG:
1107 			return SECCLASS_NETLINK_DNRT_SOCKET;
1108 		case NETLINK_KOBJECT_UEVENT:
1109 			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1110 		default:
1111 			return SECCLASS_NETLINK_SOCKET;
1112 		}
1113 	case PF_PACKET:
1114 		return SECCLASS_PACKET_SOCKET;
1115 	case PF_KEY:
1116 		return SECCLASS_KEY_SOCKET;
1117 	case PF_APPLETALK:
1118 		return SECCLASS_APPLETALK_SOCKET;
1119 	}
1120 
1121 	return SECCLASS_SOCKET;
1122 }
1123 
1124 #ifdef CONFIG_PROC_FS
1125 static int selinux_proc_get_sid(struct dentry *dentry,
1126 				u16 tclass,
1127 				u32 *sid)
1128 {
1129 	int rc;
1130 	char *buffer, *path;
1131 
1132 	buffer = (char *)__get_free_page(GFP_KERNEL);
1133 	if (!buffer)
1134 		return -ENOMEM;
1135 
1136 	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1137 	if (IS_ERR(path))
1138 		rc = PTR_ERR(path);
1139 	else {
1140 		/* each process gets a /proc/PID/ entry. Strip off the
1141 		 * PID part to get a valid selinux labeling.
1142 		 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1143 		while (path[1] >= '0' && path[1] <= '9') {
1144 			path[1] = '/';
1145 			path++;
1146 		}
1147 		rc = security_genfs_sid("proc", path, tclass, sid);
1148 	}
1149 	free_page((unsigned long)buffer);
1150 	return rc;
1151 }
1152 #else
1153 static int selinux_proc_get_sid(struct dentry *dentry,
1154 				u16 tclass,
1155 				u32 *sid)
1156 {
1157 	return -EINVAL;
1158 }
1159 #endif
1160 
1161 /* The inode's security attributes must be initialized before first use. */
1162 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1163 {
1164 	struct superblock_security_struct *sbsec = NULL;
1165 	struct inode_security_struct *isec = inode->i_security;
1166 	u32 sid;
1167 	struct dentry *dentry;
1168 #define INITCONTEXTLEN 255
1169 	char *context = NULL;
1170 	unsigned len = 0;
1171 	int rc = 0;
1172 
1173 	if (isec->initialized)
1174 		goto out;
1175 
1176 	mutex_lock(&isec->lock);
1177 	if (isec->initialized)
1178 		goto out_unlock;
1179 
1180 	sbsec = inode->i_sb->s_security;
1181 	if (!(sbsec->flags & SE_SBINITIALIZED)) {
1182 		/* Defer initialization until selinux_complete_init,
1183 		   after the initial policy is loaded and the security
1184 		   server is ready to handle calls. */
1185 		spin_lock(&sbsec->isec_lock);
1186 		if (list_empty(&isec->list))
1187 			list_add(&isec->list, &sbsec->isec_head);
1188 		spin_unlock(&sbsec->isec_lock);
1189 		goto out_unlock;
1190 	}
1191 
1192 	switch (sbsec->behavior) {
1193 	case SECURITY_FS_USE_XATTR:
1194 		if (!inode->i_op->getxattr) {
1195 			isec->sid = sbsec->def_sid;
1196 			break;
1197 		}
1198 
1199 		/* Need a dentry, since the xattr API requires one.
1200 		   Life would be simpler if we could just pass the inode. */
1201 		if (opt_dentry) {
1202 			/* Called from d_instantiate or d_splice_alias. */
1203 			dentry = dget(opt_dentry);
1204 		} else {
1205 			/* Called from selinux_complete_init, try to find a dentry. */
1206 			dentry = d_find_alias(inode);
1207 		}
1208 		if (!dentry) {
1209 			/*
1210 			 * this is can be hit on boot when a file is accessed
1211 			 * before the policy is loaded.  When we load policy we
1212 			 * may find inodes that have no dentry on the
1213 			 * sbsec->isec_head list.  No reason to complain as these
1214 			 * will get fixed up the next time we go through
1215 			 * inode_doinit with a dentry, before these inodes could
1216 			 * be used again by userspace.
1217 			 */
1218 			goto out_unlock;
1219 		}
1220 
1221 		len = INITCONTEXTLEN;
1222 		context = kmalloc(len+1, GFP_NOFS);
1223 		if (!context) {
1224 			rc = -ENOMEM;
1225 			dput(dentry);
1226 			goto out_unlock;
1227 		}
1228 		context[len] = '\0';
1229 		rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1230 					   context, len);
1231 		if (rc == -ERANGE) {
1232 			kfree(context);
1233 
1234 			/* Need a larger buffer.  Query for the right size. */
1235 			rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1236 						   NULL, 0);
1237 			if (rc < 0) {
1238 				dput(dentry);
1239 				goto out_unlock;
1240 			}
1241 			len = rc;
1242 			context = kmalloc(len+1, GFP_NOFS);
1243 			if (!context) {
1244 				rc = -ENOMEM;
1245 				dput(dentry);
1246 				goto out_unlock;
1247 			}
1248 			context[len] = '\0';
1249 			rc = inode->i_op->getxattr(dentry,
1250 						   XATTR_NAME_SELINUX,
1251 						   context, len);
1252 		}
1253 		dput(dentry);
1254 		if (rc < 0) {
1255 			if (rc != -ENODATA) {
1256 				printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1257 				       "%d for dev=%s ino=%ld\n", __func__,
1258 				       -rc, inode->i_sb->s_id, inode->i_ino);
1259 				kfree(context);
1260 				goto out_unlock;
1261 			}
1262 			/* Map ENODATA to the default file SID */
1263 			sid = sbsec->def_sid;
1264 			rc = 0;
1265 		} else {
1266 			rc = security_context_to_sid_default(context, rc, &sid,
1267 							     sbsec->def_sid,
1268 							     GFP_NOFS);
1269 			if (rc) {
1270 				char *dev = inode->i_sb->s_id;
1271 				unsigned long ino = inode->i_ino;
1272 
1273 				if (rc == -EINVAL) {
1274 					if (printk_ratelimit())
1275 						printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
1276 							"context=%s.  This indicates you may need to relabel the inode or the "
1277 							"filesystem in question.\n", ino, dev, context);
1278 				} else {
1279 					printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
1280 					       "returned %d for dev=%s ino=%ld\n",
1281 					       __func__, context, -rc, dev, ino);
1282 				}
1283 				kfree(context);
1284 				/* Leave with the unlabeled SID */
1285 				rc = 0;
1286 				break;
1287 			}
1288 		}
1289 		kfree(context);
1290 		isec->sid = sid;
1291 		break;
1292 	case SECURITY_FS_USE_TASK:
1293 		isec->sid = isec->task_sid;
1294 		break;
1295 	case SECURITY_FS_USE_TRANS:
1296 		/* Default to the fs SID. */
1297 		isec->sid = sbsec->sid;
1298 
1299 		/* Try to obtain a transition SID. */
1300 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
1301 		rc = security_transition_sid(isec->task_sid, sbsec->sid,
1302 					     isec->sclass, NULL, &sid);
1303 		if (rc)
1304 			goto out_unlock;
1305 		isec->sid = sid;
1306 		break;
1307 	case SECURITY_FS_USE_MNTPOINT:
1308 		isec->sid = sbsec->mntpoint_sid;
1309 		break;
1310 	default:
1311 		/* Default to the fs superblock SID. */
1312 		isec->sid = sbsec->sid;
1313 
1314 		if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
1315 			if (opt_dentry) {
1316 				isec->sclass = inode_mode_to_security_class(inode->i_mode);
1317 				rc = selinux_proc_get_sid(opt_dentry,
1318 							  isec->sclass,
1319 							  &sid);
1320 				if (rc)
1321 					goto out_unlock;
1322 				isec->sid = sid;
1323 			}
1324 		}
1325 		break;
1326 	}
1327 
1328 	isec->initialized = 1;
1329 
1330 out_unlock:
1331 	mutex_unlock(&isec->lock);
1332 out:
1333 	if (isec->sclass == SECCLASS_FILE)
1334 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
1335 	return rc;
1336 }
1337 
1338 /* Convert a Linux signal to an access vector. */
1339 static inline u32 signal_to_av(int sig)
1340 {
1341 	u32 perm = 0;
1342 
1343 	switch (sig) {
1344 	case SIGCHLD:
1345 		/* Commonly granted from child to parent. */
1346 		perm = PROCESS__SIGCHLD;
1347 		break;
1348 	case SIGKILL:
1349 		/* Cannot be caught or ignored */
1350 		perm = PROCESS__SIGKILL;
1351 		break;
1352 	case SIGSTOP:
1353 		/* Cannot be caught or ignored */
1354 		perm = PROCESS__SIGSTOP;
1355 		break;
1356 	default:
1357 		/* All other signals. */
1358 		perm = PROCESS__SIGNAL;
1359 		break;
1360 	}
1361 
1362 	return perm;
1363 }
1364 
1365 /*
1366  * Check permission between a pair of credentials
1367  * fork check, ptrace check, etc.
1368  */
1369 static int cred_has_perm(const struct cred *actor,
1370 			 const struct cred *target,
1371 			 u32 perms)
1372 {
1373 	u32 asid = cred_sid(actor), tsid = cred_sid(target);
1374 
1375 	return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1376 }
1377 
1378 /*
1379  * Check permission between a pair of tasks, e.g. signal checks,
1380  * fork check, ptrace check, etc.
1381  * tsk1 is the actor and tsk2 is the target
1382  * - this uses the default subjective creds of tsk1
1383  */
1384 static int task_has_perm(const struct task_struct *tsk1,
1385 			 const struct task_struct *tsk2,
1386 			 u32 perms)
1387 {
1388 	const struct task_security_struct *__tsec1, *__tsec2;
1389 	u32 sid1, sid2;
1390 
1391 	rcu_read_lock();
1392 	__tsec1 = __task_cred(tsk1)->security;	sid1 = __tsec1->sid;
1393 	__tsec2 = __task_cred(tsk2)->security;	sid2 = __tsec2->sid;
1394 	rcu_read_unlock();
1395 	return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1396 }
1397 
1398 /*
1399  * Check permission between current and another task, e.g. signal checks,
1400  * fork check, ptrace check, etc.
1401  * current is the actor and tsk2 is the target
1402  * - this uses current's subjective creds
1403  */
1404 static int current_has_perm(const struct task_struct *tsk,
1405 			    u32 perms)
1406 {
1407 	u32 sid, tsid;
1408 
1409 	sid = current_sid();
1410 	tsid = task_sid(tsk);
1411 	return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1412 }
1413 
1414 #if CAP_LAST_CAP > 63
1415 #error Fix SELinux to handle capabilities > 63.
1416 #endif
1417 
1418 /* Check whether a task is allowed to use a capability. */
1419 static int cred_has_capability(const struct cred *cred,
1420 			       int cap, int audit)
1421 {
1422 	struct common_audit_data ad;
1423 	struct av_decision avd;
1424 	u16 sclass;
1425 	u32 sid = cred_sid(cred);
1426 	u32 av = CAP_TO_MASK(cap);
1427 	int rc;
1428 
1429 	ad.type = LSM_AUDIT_DATA_CAP;
1430 	ad.u.cap = cap;
1431 
1432 	switch (CAP_TO_INDEX(cap)) {
1433 	case 0:
1434 		sclass = SECCLASS_CAPABILITY;
1435 		break;
1436 	case 1:
1437 		sclass = SECCLASS_CAPABILITY2;
1438 		break;
1439 	default:
1440 		printk(KERN_ERR
1441 		       "SELinux:  out of range capability %d\n", cap);
1442 		BUG();
1443 		return -EINVAL;
1444 	}
1445 
1446 	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1447 	if (audit == SECURITY_CAP_AUDIT) {
1448 		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
1449 		if (rc2)
1450 			return rc2;
1451 	}
1452 	return rc;
1453 }
1454 
1455 /* Check whether a task is allowed to use a system operation. */
1456 static int task_has_system(struct task_struct *tsk,
1457 			   u32 perms)
1458 {
1459 	u32 sid = task_sid(tsk);
1460 
1461 	return avc_has_perm(sid, SECINITSID_KERNEL,
1462 			    SECCLASS_SYSTEM, perms, NULL);
1463 }
1464 
1465 /* Check whether a task has a particular permission to an inode.
1466    The 'adp' parameter is optional and allows other audit
1467    data to be passed (e.g. the dentry). */
1468 static int inode_has_perm(const struct cred *cred,
1469 			  struct inode *inode,
1470 			  u32 perms,
1471 			  struct common_audit_data *adp,
1472 			  unsigned flags)
1473 {
1474 	struct inode_security_struct *isec;
1475 	u32 sid;
1476 
1477 	validate_creds(cred);
1478 
1479 	if (unlikely(IS_PRIVATE(inode)))
1480 		return 0;
1481 
1482 	sid = cred_sid(cred);
1483 	isec = inode->i_security;
1484 
1485 	return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags);
1486 }
1487 
1488 /* Same as inode_has_perm, but pass explicit audit data containing
1489    the dentry to help the auditing code to more easily generate the
1490    pathname if needed. */
1491 static inline int dentry_has_perm(const struct cred *cred,
1492 				  struct dentry *dentry,
1493 				  u32 av)
1494 {
1495 	struct inode *inode = dentry->d_inode;
1496 	struct common_audit_data ad;
1497 
1498 	ad.type = LSM_AUDIT_DATA_DENTRY;
1499 	ad.u.dentry = dentry;
1500 	return inode_has_perm(cred, inode, av, &ad, 0);
1501 }
1502 
1503 /* Same as inode_has_perm, but pass explicit audit data containing
1504    the path to help the auditing code to more easily generate the
1505    pathname if needed. */
1506 static inline int path_has_perm(const struct cred *cred,
1507 				struct path *path,
1508 				u32 av)
1509 {
1510 	struct inode *inode = path->dentry->d_inode;
1511 	struct common_audit_data ad;
1512 
1513 	ad.type = LSM_AUDIT_DATA_PATH;
1514 	ad.u.path = *path;
1515 	return inode_has_perm(cred, inode, av, &ad, 0);
1516 }
1517 
1518 /* Check whether a task can use an open file descriptor to
1519    access an inode in a given way.  Check access to the
1520    descriptor itself, and then use dentry_has_perm to
1521    check a particular permission to the file.
1522    Access to the descriptor is implicitly granted if it
1523    has the same SID as the process.  If av is zero, then
1524    access to the file is not checked, e.g. for cases
1525    where only the descriptor is affected like seek. */
1526 static int file_has_perm(const struct cred *cred,
1527 			 struct file *file,
1528 			 u32 av)
1529 {
1530 	struct file_security_struct *fsec = file->f_security;
1531 	struct inode *inode = file->f_path.dentry->d_inode;
1532 	struct common_audit_data ad;
1533 	u32 sid = cred_sid(cred);
1534 	int rc;
1535 
1536 	ad.type = LSM_AUDIT_DATA_PATH;
1537 	ad.u.path = file->f_path;
1538 
1539 	if (sid != fsec->sid) {
1540 		rc = avc_has_perm(sid, fsec->sid,
1541 				  SECCLASS_FD,
1542 				  FD__USE,
1543 				  &ad);
1544 		if (rc)
1545 			goto out;
1546 	}
1547 
1548 	/* av is zero if only checking access to the descriptor. */
1549 	rc = 0;
1550 	if (av)
1551 		rc = inode_has_perm(cred, inode, av, &ad, 0);
1552 
1553 out:
1554 	return rc;
1555 }
1556 
1557 /* Check whether a task can create a file. */
1558 static int may_create(struct inode *dir,
1559 		      struct dentry *dentry,
1560 		      u16 tclass)
1561 {
1562 	const struct task_security_struct *tsec = current_security();
1563 	struct inode_security_struct *dsec;
1564 	struct superblock_security_struct *sbsec;
1565 	u32 sid, newsid;
1566 	struct common_audit_data ad;
1567 	int rc;
1568 
1569 	dsec = dir->i_security;
1570 	sbsec = dir->i_sb->s_security;
1571 
1572 	sid = tsec->sid;
1573 	newsid = tsec->create_sid;
1574 
1575 	ad.type = LSM_AUDIT_DATA_DENTRY;
1576 	ad.u.dentry = dentry;
1577 
1578 	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1579 			  DIR__ADD_NAME | DIR__SEARCH,
1580 			  &ad);
1581 	if (rc)
1582 		return rc;
1583 
1584 	if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
1585 		rc = security_transition_sid(sid, dsec->sid, tclass,
1586 					     &dentry->d_name, &newsid);
1587 		if (rc)
1588 			return rc;
1589 	}
1590 
1591 	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1592 	if (rc)
1593 		return rc;
1594 
1595 	return avc_has_perm(newsid, sbsec->sid,
1596 			    SECCLASS_FILESYSTEM,
1597 			    FILESYSTEM__ASSOCIATE, &ad);
1598 }
1599 
1600 /* Check whether a task can create a key. */
1601 static int may_create_key(u32 ksid,
1602 			  struct task_struct *ctx)
1603 {
1604 	u32 sid = task_sid(ctx);
1605 
1606 	return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1607 }
1608 
1609 #define MAY_LINK	0
1610 #define MAY_UNLINK	1
1611 #define MAY_RMDIR	2
1612 
1613 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1614 static int may_link(struct inode *dir,
1615 		    struct dentry *dentry,
1616 		    int kind)
1617 
1618 {
1619 	struct inode_security_struct *dsec, *isec;
1620 	struct common_audit_data ad;
1621 	u32 sid = current_sid();
1622 	u32 av;
1623 	int rc;
1624 
1625 	dsec = dir->i_security;
1626 	isec = dentry->d_inode->i_security;
1627 
1628 	ad.type = LSM_AUDIT_DATA_DENTRY;
1629 	ad.u.dentry = dentry;
1630 
1631 	av = DIR__SEARCH;
1632 	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1633 	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1634 	if (rc)
1635 		return rc;
1636 
1637 	switch (kind) {
1638 	case MAY_LINK:
1639 		av = FILE__LINK;
1640 		break;
1641 	case MAY_UNLINK:
1642 		av = FILE__UNLINK;
1643 		break;
1644 	case MAY_RMDIR:
1645 		av = DIR__RMDIR;
1646 		break;
1647 	default:
1648 		printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
1649 			__func__, kind);
1650 		return 0;
1651 	}
1652 
1653 	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1654 	return rc;
1655 }
1656 
1657 static inline int may_rename(struct inode *old_dir,
1658 			     struct dentry *old_dentry,
1659 			     struct inode *new_dir,
1660 			     struct dentry *new_dentry)
1661 {
1662 	struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1663 	struct common_audit_data ad;
1664 	u32 sid = current_sid();
1665 	u32 av;
1666 	int old_is_dir, new_is_dir;
1667 	int rc;
1668 
1669 	old_dsec = old_dir->i_security;
1670 	old_isec = old_dentry->d_inode->i_security;
1671 	old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1672 	new_dsec = new_dir->i_security;
1673 
1674 	ad.type = LSM_AUDIT_DATA_DENTRY;
1675 
1676 	ad.u.dentry = old_dentry;
1677 	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1678 			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1679 	if (rc)
1680 		return rc;
1681 	rc = avc_has_perm(sid, old_isec->sid,
1682 			  old_isec->sclass, FILE__RENAME, &ad);
1683 	if (rc)
1684 		return rc;
1685 	if (old_is_dir && new_dir != old_dir) {
1686 		rc = avc_has_perm(sid, old_isec->sid,
1687 				  old_isec->sclass, DIR__REPARENT, &ad);
1688 		if (rc)
1689 			return rc;
1690 	}
1691 
1692 	ad.u.dentry = new_dentry;
1693 	av = DIR__ADD_NAME | DIR__SEARCH;
1694 	if (new_dentry->d_inode)
1695 		av |= DIR__REMOVE_NAME;
1696 	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1697 	if (rc)
1698 		return rc;
1699 	if (new_dentry->d_inode) {
1700 		new_isec = new_dentry->d_inode->i_security;
1701 		new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1702 		rc = avc_has_perm(sid, new_isec->sid,
1703 				  new_isec->sclass,
1704 				  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1705 		if (rc)
1706 			return rc;
1707 	}
1708 
1709 	return 0;
1710 }
1711 
1712 /* Check whether a task can perform a filesystem operation. */
1713 static int superblock_has_perm(const struct cred *cred,
1714 			       struct super_block *sb,
1715 			       u32 perms,
1716 			       struct common_audit_data *ad)
1717 {
1718 	struct superblock_security_struct *sbsec;
1719 	u32 sid = cred_sid(cred);
1720 
1721 	sbsec = sb->s_security;
1722 	return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1723 }
1724 
1725 /* Convert a Linux mode and permission mask to an access vector. */
1726 static inline u32 file_mask_to_av(int mode, int mask)
1727 {
1728 	u32 av = 0;
1729 
1730 	if (!S_ISDIR(mode)) {
1731 		if (mask & MAY_EXEC)
1732 			av |= FILE__EXECUTE;
1733 		if (mask & MAY_READ)
1734 			av |= FILE__READ;
1735 
1736 		if (mask & MAY_APPEND)
1737 			av |= FILE__APPEND;
1738 		else if (mask & MAY_WRITE)
1739 			av |= FILE__WRITE;
1740 
1741 	} else {
1742 		if (mask & MAY_EXEC)
1743 			av |= DIR__SEARCH;
1744 		if (mask & MAY_WRITE)
1745 			av |= DIR__WRITE;
1746 		if (mask & MAY_READ)
1747 			av |= DIR__READ;
1748 	}
1749 
1750 	return av;
1751 }
1752 
1753 /* Convert a Linux file to an access vector. */
1754 static inline u32 file_to_av(struct file *file)
1755 {
1756 	u32 av = 0;
1757 
1758 	if (file->f_mode & FMODE_READ)
1759 		av |= FILE__READ;
1760 	if (file->f_mode & FMODE_WRITE) {
1761 		if (file->f_flags & O_APPEND)
1762 			av |= FILE__APPEND;
1763 		else
1764 			av |= FILE__WRITE;
1765 	}
1766 	if (!av) {
1767 		/*
1768 		 * Special file opened with flags 3 for ioctl-only use.
1769 		 */
1770 		av = FILE__IOCTL;
1771 	}
1772 
1773 	return av;
1774 }
1775 
1776 /*
1777  * Convert a file to an access vector and include the correct open
1778  * open permission.
1779  */
1780 static inline u32 open_file_to_av(struct file *file)
1781 {
1782 	u32 av = file_to_av(file);
1783 
1784 	if (selinux_policycap_openperm)
1785 		av |= FILE__OPEN;
1786 
1787 	return av;
1788 }
1789 
1790 /* Hook functions begin here. */
1791 
1792 static int selinux_ptrace_access_check(struct task_struct *child,
1793 				     unsigned int mode)
1794 {
1795 	int rc;
1796 
1797 	rc = cap_ptrace_access_check(child, mode);
1798 	if (rc)
1799 		return rc;
1800 
1801 	if (mode & PTRACE_MODE_READ) {
1802 		u32 sid = current_sid();
1803 		u32 csid = task_sid(child);
1804 		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
1805 	}
1806 
1807 	return current_has_perm(child, PROCESS__PTRACE);
1808 }
1809 
1810 static int selinux_ptrace_traceme(struct task_struct *parent)
1811 {
1812 	int rc;
1813 
1814 	rc = cap_ptrace_traceme(parent);
1815 	if (rc)
1816 		return rc;
1817 
1818 	return task_has_perm(parent, current, PROCESS__PTRACE);
1819 }
1820 
1821 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1822 			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
1823 {
1824 	int error;
1825 
1826 	error = current_has_perm(target, PROCESS__GETCAP);
1827 	if (error)
1828 		return error;
1829 
1830 	return cap_capget(target, effective, inheritable, permitted);
1831 }
1832 
1833 static int selinux_capset(struct cred *new, const struct cred *old,
1834 			  const kernel_cap_t *effective,
1835 			  const kernel_cap_t *inheritable,
1836 			  const kernel_cap_t *permitted)
1837 {
1838 	int error;
1839 
1840 	error = cap_capset(new, old,
1841 				      effective, inheritable, permitted);
1842 	if (error)
1843 		return error;
1844 
1845 	return cred_has_perm(old, new, PROCESS__SETCAP);
1846 }
1847 
1848 /*
1849  * (This comment used to live with the selinux_task_setuid hook,
1850  * which was removed).
1851  *
1852  * Since setuid only affects the current process, and since the SELinux
1853  * controls are not based on the Linux identity attributes, SELinux does not
1854  * need to control this operation.  However, SELinux does control the use of
1855  * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
1856  */
1857 
1858 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
1859 			   int cap, int audit)
1860 {
1861 	int rc;
1862 
1863 	rc = cap_capable(cred, ns, cap, audit);
1864 	if (rc)
1865 		return rc;
1866 
1867 	return cred_has_capability(cred, cap, audit);
1868 }
1869 
1870 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1871 {
1872 	const struct cred *cred = current_cred();
1873 	int rc = 0;
1874 
1875 	if (!sb)
1876 		return 0;
1877 
1878 	switch (cmds) {
1879 	case Q_SYNC:
1880 	case Q_QUOTAON:
1881 	case Q_QUOTAOFF:
1882 	case Q_SETINFO:
1883 	case Q_SETQUOTA:
1884 		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
1885 		break;
1886 	case Q_GETFMT:
1887 	case Q_GETINFO:
1888 	case Q_GETQUOTA:
1889 		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
1890 		break;
1891 	default:
1892 		rc = 0;  /* let the kernel handle invalid cmds */
1893 		break;
1894 	}
1895 	return rc;
1896 }
1897 
1898 static int selinux_quota_on(struct dentry *dentry)
1899 {
1900 	const struct cred *cred = current_cred();
1901 
1902 	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
1903 }
1904 
1905 static int selinux_syslog(int type)
1906 {
1907 	int rc;
1908 
1909 	switch (type) {
1910 	case SYSLOG_ACTION_READ_ALL:	/* Read last kernel messages */
1911 	case SYSLOG_ACTION_SIZE_BUFFER:	/* Return size of the log buffer */
1912 		rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1913 		break;
1914 	case SYSLOG_ACTION_CONSOLE_OFF:	/* Disable logging to console */
1915 	case SYSLOG_ACTION_CONSOLE_ON:	/* Enable logging to console */
1916 	/* Set level of messages printed to console */
1917 	case SYSLOG_ACTION_CONSOLE_LEVEL:
1918 		rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1919 		break;
1920 	case SYSLOG_ACTION_CLOSE:	/* Close log */
1921 	case SYSLOG_ACTION_OPEN:	/* Open log */
1922 	case SYSLOG_ACTION_READ:	/* Read from log */
1923 	case SYSLOG_ACTION_READ_CLEAR:	/* Read/clear last kernel messages */
1924 	case SYSLOG_ACTION_CLEAR:	/* Clear ring buffer */
1925 	default:
1926 		rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1927 		break;
1928 	}
1929 	return rc;
1930 }
1931 
1932 /*
1933  * Check that a process has enough memory to allocate a new virtual
1934  * mapping. 0 means there is enough memory for the allocation to
1935  * succeed and -ENOMEM implies there is not.
1936  *
1937  * Do not audit the selinux permission check, as this is applied to all
1938  * processes that allocate mappings.
1939  */
1940 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
1941 {
1942 	int rc, cap_sys_admin = 0;
1943 
1944 	rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
1945 			     SECURITY_CAP_NOAUDIT);
1946 	if (rc == 0)
1947 		cap_sys_admin = 1;
1948 
1949 	return __vm_enough_memory(mm, pages, cap_sys_admin);
1950 }
1951 
1952 /* binprm security operations */
1953 
1954 static int selinux_bprm_set_creds(struct linux_binprm *bprm)
1955 {
1956 	const struct task_security_struct *old_tsec;
1957 	struct task_security_struct *new_tsec;
1958 	struct inode_security_struct *isec;
1959 	struct common_audit_data ad;
1960 	struct inode *inode = bprm->file->f_path.dentry->d_inode;
1961 	int rc;
1962 
1963 	rc = cap_bprm_set_creds(bprm);
1964 	if (rc)
1965 		return rc;
1966 
1967 	/* SELinux context only depends on initial program or script and not
1968 	 * the script interpreter */
1969 	if (bprm->cred_prepared)
1970 		return 0;
1971 
1972 	old_tsec = current_security();
1973 	new_tsec = bprm->cred->security;
1974 	isec = inode->i_security;
1975 
1976 	/* Default to the current task SID. */
1977 	new_tsec->sid = old_tsec->sid;
1978 	new_tsec->osid = old_tsec->sid;
1979 
1980 	/* Reset fs, key, and sock SIDs on execve. */
1981 	new_tsec->create_sid = 0;
1982 	new_tsec->keycreate_sid = 0;
1983 	new_tsec->sockcreate_sid = 0;
1984 
1985 	if (old_tsec->exec_sid) {
1986 		new_tsec->sid = old_tsec->exec_sid;
1987 		/* Reset exec SID on execve. */
1988 		new_tsec->exec_sid = 0;
1989 
1990 		/*
1991 		 * Minimize confusion: if no_new_privs and a transition is
1992 		 * explicitly requested, then fail the exec.
1993 		 */
1994 		if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)
1995 			return -EPERM;
1996 	} else {
1997 		/* Check for a default transition on this program. */
1998 		rc = security_transition_sid(old_tsec->sid, isec->sid,
1999 					     SECCLASS_PROCESS, NULL,
2000 					     &new_tsec->sid);
2001 		if (rc)
2002 			return rc;
2003 	}
2004 
2005 	ad.type = LSM_AUDIT_DATA_PATH;
2006 	ad.u.path = bprm->file->f_path;
2007 
2008 	if ((bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) ||
2009 	    (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS))
2010 		new_tsec->sid = old_tsec->sid;
2011 
2012 	if (new_tsec->sid == old_tsec->sid) {
2013 		rc = avc_has_perm(old_tsec->sid, isec->sid,
2014 				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2015 		if (rc)
2016 			return rc;
2017 	} else {
2018 		/* Check permissions for the transition. */
2019 		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2020 				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2021 		if (rc)
2022 			return rc;
2023 
2024 		rc = avc_has_perm(new_tsec->sid, isec->sid,
2025 				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2026 		if (rc)
2027 			return rc;
2028 
2029 		/* Check for shared state */
2030 		if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2031 			rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2032 					  SECCLASS_PROCESS, PROCESS__SHARE,
2033 					  NULL);
2034 			if (rc)
2035 				return -EPERM;
2036 		}
2037 
2038 		/* Make sure that anyone attempting to ptrace over a task that
2039 		 * changes its SID has the appropriate permit */
2040 		if (bprm->unsafe &
2041 		    (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2042 			struct task_struct *tracer;
2043 			struct task_security_struct *sec;
2044 			u32 ptsid = 0;
2045 
2046 			rcu_read_lock();
2047 			tracer = ptrace_parent(current);
2048 			if (likely(tracer != NULL)) {
2049 				sec = __task_cred(tracer)->security;
2050 				ptsid = sec->sid;
2051 			}
2052 			rcu_read_unlock();
2053 
2054 			if (ptsid != 0) {
2055 				rc = avc_has_perm(ptsid, new_tsec->sid,
2056 						  SECCLASS_PROCESS,
2057 						  PROCESS__PTRACE, NULL);
2058 				if (rc)
2059 					return -EPERM;
2060 			}
2061 		}
2062 
2063 		/* Clear any possibly unsafe personality bits on exec: */
2064 		bprm->per_clear |= PER_CLEAR_ON_SETID;
2065 	}
2066 
2067 	return 0;
2068 }
2069 
2070 static int selinux_bprm_secureexec(struct linux_binprm *bprm)
2071 {
2072 	const struct task_security_struct *tsec = current_security();
2073 	u32 sid, osid;
2074 	int atsecure = 0;
2075 
2076 	sid = tsec->sid;
2077 	osid = tsec->osid;
2078 
2079 	if (osid != sid) {
2080 		/* Enable secure mode for SIDs transitions unless
2081 		   the noatsecure permission is granted between
2082 		   the two SIDs, i.e. ahp returns 0. */
2083 		atsecure = avc_has_perm(osid, sid,
2084 					SECCLASS_PROCESS,
2085 					PROCESS__NOATSECURE, NULL);
2086 	}
2087 
2088 	return (atsecure || cap_bprm_secureexec(bprm));
2089 }
2090 
2091 /* Derived from fs/exec.c:flush_old_files. */
2092 static inline void flush_unauthorized_files(const struct cred *cred,
2093 					    struct files_struct *files)
2094 {
2095 	struct file *file, *devnull = NULL;
2096 	struct tty_struct *tty;
2097 	struct fdtable *fdt;
2098 	long j = -1;
2099 	int drop_tty = 0;
2100 
2101 	tty = get_current_tty();
2102 	if (tty) {
2103 		spin_lock(&tty_files_lock);
2104 		if (!list_empty(&tty->tty_files)) {
2105 			struct tty_file_private *file_priv;
2106 
2107 			/* Revalidate access to controlling tty.
2108 			   Use path_has_perm on the tty path directly rather
2109 			   than using file_has_perm, as this particular open
2110 			   file may belong to another process and we are only
2111 			   interested in the inode-based check here. */
2112 			file_priv = list_first_entry(&tty->tty_files,
2113 						struct tty_file_private, list);
2114 			file = file_priv->file;
2115 			if (path_has_perm(cred, &file->f_path, FILE__READ | FILE__WRITE))
2116 				drop_tty = 1;
2117 		}
2118 		spin_unlock(&tty_files_lock);
2119 		tty_kref_put(tty);
2120 	}
2121 	/* Reset controlling tty. */
2122 	if (drop_tty)
2123 		no_tty();
2124 
2125 	/* Revalidate access to inherited open files. */
2126 	spin_lock(&files->file_lock);
2127 	for (;;) {
2128 		unsigned long set, i;
2129 		int fd;
2130 
2131 		j++;
2132 		i = j * __NFDBITS;
2133 		fdt = files_fdtable(files);
2134 		if (i >= fdt->max_fds)
2135 			break;
2136 		set = fdt->open_fds[j];
2137 		if (!set)
2138 			continue;
2139 		spin_unlock(&files->file_lock);
2140 		for ( ; set ; i++, set >>= 1) {
2141 			if (set & 1) {
2142 				file = fget(i);
2143 				if (!file)
2144 					continue;
2145 				if (file_has_perm(cred,
2146 						  file,
2147 						  file_to_av(file))) {
2148 					sys_close(i);
2149 					fd = get_unused_fd();
2150 					if (fd != i) {
2151 						if (fd >= 0)
2152 							put_unused_fd(fd);
2153 						fput(file);
2154 						continue;
2155 					}
2156 					if (devnull) {
2157 						get_file(devnull);
2158 					} else {
2159 						devnull = dentry_open(
2160 							dget(selinux_null),
2161 							mntget(selinuxfs_mount),
2162 							O_RDWR, cred);
2163 						if (IS_ERR(devnull)) {
2164 							devnull = NULL;
2165 							put_unused_fd(fd);
2166 							fput(file);
2167 							continue;
2168 						}
2169 					}
2170 					fd_install(fd, devnull);
2171 				}
2172 				fput(file);
2173 			}
2174 		}
2175 		spin_lock(&files->file_lock);
2176 
2177 	}
2178 	spin_unlock(&files->file_lock);
2179 }
2180 
2181 /*
2182  * Prepare a process for imminent new credential changes due to exec
2183  */
2184 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2185 {
2186 	struct task_security_struct *new_tsec;
2187 	struct rlimit *rlim, *initrlim;
2188 	int rc, i;
2189 
2190 	new_tsec = bprm->cred->security;
2191 	if (new_tsec->sid == new_tsec->osid)
2192 		return;
2193 
2194 	/* Close files for which the new task SID is not authorized. */
2195 	flush_unauthorized_files(bprm->cred, current->files);
2196 
2197 	/* Always clear parent death signal on SID transitions. */
2198 	current->pdeath_signal = 0;
2199 
2200 	/* Check whether the new SID can inherit resource limits from the old
2201 	 * SID.  If not, reset all soft limits to the lower of the current
2202 	 * task's hard limit and the init task's soft limit.
2203 	 *
2204 	 * Note that the setting of hard limits (even to lower them) can be
2205 	 * controlled by the setrlimit check.  The inclusion of the init task's
2206 	 * soft limit into the computation is to avoid resetting soft limits
2207 	 * higher than the default soft limit for cases where the default is
2208 	 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2209 	 */
2210 	rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2211 			  PROCESS__RLIMITINH, NULL);
2212 	if (rc) {
2213 		/* protect against do_prlimit() */
2214 		task_lock(current);
2215 		for (i = 0; i < RLIM_NLIMITS; i++) {
2216 			rlim = current->signal->rlim + i;
2217 			initrlim = init_task.signal->rlim + i;
2218 			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2219 		}
2220 		task_unlock(current);
2221 		update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2222 	}
2223 }
2224 
2225 /*
2226  * Clean up the process immediately after the installation of new credentials
2227  * due to exec
2228  */
2229 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2230 {
2231 	const struct task_security_struct *tsec = current_security();
2232 	struct itimerval itimer;
2233 	u32 osid, sid;
2234 	int rc, i;
2235 
2236 	osid = tsec->osid;
2237 	sid = tsec->sid;
2238 
2239 	if (sid == osid)
2240 		return;
2241 
2242 	/* Check whether the new SID can inherit signal state from the old SID.
2243 	 * If not, clear itimers to avoid subsequent signal generation and
2244 	 * flush and unblock signals.
2245 	 *
2246 	 * This must occur _after_ the task SID has been updated so that any
2247 	 * kill done after the flush will be checked against the new SID.
2248 	 */
2249 	rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2250 	if (rc) {
2251 		memset(&itimer, 0, sizeof itimer);
2252 		for (i = 0; i < 3; i++)
2253 			do_setitimer(i, &itimer, NULL);
2254 		spin_lock_irq(&current->sighand->siglock);
2255 		if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
2256 			__flush_signals(current);
2257 			flush_signal_handlers(current, 1);
2258 			sigemptyset(&current->blocked);
2259 		}
2260 		spin_unlock_irq(&current->sighand->siglock);
2261 	}
2262 
2263 	/* Wake up the parent if it is waiting so that it can recheck
2264 	 * wait permission to the new task SID. */
2265 	read_lock(&tasklist_lock);
2266 	__wake_up_parent(current, current->real_parent);
2267 	read_unlock(&tasklist_lock);
2268 }
2269 
2270 /* superblock security operations */
2271 
2272 static int selinux_sb_alloc_security(struct super_block *sb)
2273 {
2274 	return superblock_alloc_security(sb);
2275 }
2276 
2277 static void selinux_sb_free_security(struct super_block *sb)
2278 {
2279 	superblock_free_security(sb);
2280 }
2281 
2282 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2283 {
2284 	if (plen > olen)
2285 		return 0;
2286 
2287 	return !memcmp(prefix, option, plen);
2288 }
2289 
2290 static inline int selinux_option(char *option, int len)
2291 {
2292 	return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2293 		match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2294 		match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2295 		match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2296 		match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
2297 }
2298 
2299 static inline void take_option(char **to, char *from, int *first, int len)
2300 {
2301 	if (!*first) {
2302 		**to = ',';
2303 		*to += 1;
2304 	} else
2305 		*first = 0;
2306 	memcpy(*to, from, len);
2307 	*to += len;
2308 }
2309 
2310 static inline void take_selinux_option(char **to, char *from, int *first,
2311 				       int len)
2312 {
2313 	int current_size = 0;
2314 
2315 	if (!*first) {
2316 		**to = '|';
2317 		*to += 1;
2318 	} else
2319 		*first = 0;
2320 
2321 	while (current_size < len) {
2322 		if (*from != '"') {
2323 			**to = *from;
2324 			*to += 1;
2325 		}
2326 		from += 1;
2327 		current_size += 1;
2328 	}
2329 }
2330 
2331 static int selinux_sb_copy_data(char *orig, char *copy)
2332 {
2333 	int fnosec, fsec, rc = 0;
2334 	char *in_save, *in_curr, *in_end;
2335 	char *sec_curr, *nosec_save, *nosec;
2336 	int open_quote = 0;
2337 
2338 	in_curr = orig;
2339 	sec_curr = copy;
2340 
2341 	nosec = (char *)get_zeroed_page(GFP_KERNEL);
2342 	if (!nosec) {
2343 		rc = -ENOMEM;
2344 		goto out;
2345 	}
2346 
2347 	nosec_save = nosec;
2348 	fnosec = fsec = 1;
2349 	in_save = in_end = orig;
2350 
2351 	do {
2352 		if (*in_end == '"')
2353 			open_quote = !open_quote;
2354 		if ((*in_end == ',' && open_quote == 0) ||
2355 				*in_end == '\0') {
2356 			int len = in_end - in_curr;
2357 
2358 			if (selinux_option(in_curr, len))
2359 				take_selinux_option(&sec_curr, in_curr, &fsec, len);
2360 			else
2361 				take_option(&nosec, in_curr, &fnosec, len);
2362 
2363 			in_curr = in_end + 1;
2364 		}
2365 	} while (*in_end++);
2366 
2367 	strcpy(in_save, nosec_save);
2368 	free_page((unsigned long)nosec_save);
2369 out:
2370 	return rc;
2371 }
2372 
2373 static int selinux_sb_remount(struct super_block *sb, void *data)
2374 {
2375 	int rc, i, *flags;
2376 	struct security_mnt_opts opts;
2377 	char *secdata, **mount_options;
2378 	struct superblock_security_struct *sbsec = sb->s_security;
2379 
2380 	if (!(sbsec->flags & SE_SBINITIALIZED))
2381 		return 0;
2382 
2383 	if (!data)
2384 		return 0;
2385 
2386 	if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
2387 		return 0;
2388 
2389 	security_init_mnt_opts(&opts);
2390 	secdata = alloc_secdata();
2391 	if (!secdata)
2392 		return -ENOMEM;
2393 	rc = selinux_sb_copy_data(data, secdata);
2394 	if (rc)
2395 		goto out_free_secdata;
2396 
2397 	rc = selinux_parse_opts_str(secdata, &opts);
2398 	if (rc)
2399 		goto out_free_secdata;
2400 
2401 	mount_options = opts.mnt_opts;
2402 	flags = opts.mnt_opts_flags;
2403 
2404 	for (i = 0; i < opts.num_mnt_opts; i++) {
2405 		u32 sid;
2406 		size_t len;
2407 
2408 		if (flags[i] == SE_SBLABELSUPP)
2409 			continue;
2410 		len = strlen(mount_options[i]);
2411 		rc = security_context_to_sid(mount_options[i], len, &sid);
2412 		if (rc) {
2413 			printk(KERN_WARNING "SELinux: security_context_to_sid"
2414 			       "(%s) failed for (dev %s, type %s) errno=%d\n",
2415 			       mount_options[i], sb->s_id, sb->s_type->name, rc);
2416 			goto out_free_opts;
2417 		}
2418 		rc = -EINVAL;
2419 		switch (flags[i]) {
2420 		case FSCONTEXT_MNT:
2421 			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
2422 				goto out_bad_option;
2423 			break;
2424 		case CONTEXT_MNT:
2425 			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
2426 				goto out_bad_option;
2427 			break;
2428 		case ROOTCONTEXT_MNT: {
2429 			struct inode_security_struct *root_isec;
2430 			root_isec = sb->s_root->d_inode->i_security;
2431 
2432 			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
2433 				goto out_bad_option;
2434 			break;
2435 		}
2436 		case DEFCONTEXT_MNT:
2437 			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
2438 				goto out_bad_option;
2439 			break;
2440 		default:
2441 			goto out_free_opts;
2442 		}
2443 	}
2444 
2445 	rc = 0;
2446 out_free_opts:
2447 	security_free_mnt_opts(&opts);
2448 out_free_secdata:
2449 	free_secdata(secdata);
2450 	return rc;
2451 out_bad_option:
2452 	printk(KERN_WARNING "SELinux: unable to change security options "
2453 	       "during remount (dev %s, type=%s)\n", sb->s_id,
2454 	       sb->s_type->name);
2455 	goto out_free_opts;
2456 }
2457 
2458 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
2459 {
2460 	const struct cred *cred = current_cred();
2461 	struct common_audit_data ad;
2462 	int rc;
2463 
2464 	rc = superblock_doinit(sb, data);
2465 	if (rc)
2466 		return rc;
2467 
2468 	/* Allow all mounts performed by the kernel */
2469 	if (flags & MS_KERNMOUNT)
2470 		return 0;
2471 
2472 	ad.type = LSM_AUDIT_DATA_DENTRY;
2473 	ad.u.dentry = sb->s_root;
2474 	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2475 }
2476 
2477 static int selinux_sb_statfs(struct dentry *dentry)
2478 {
2479 	const struct cred *cred = current_cred();
2480 	struct common_audit_data ad;
2481 
2482 	ad.type = LSM_AUDIT_DATA_DENTRY;
2483 	ad.u.dentry = dentry->d_sb->s_root;
2484 	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2485 }
2486 
2487 static int selinux_mount(char *dev_name,
2488 			 struct path *path,
2489 			 char *type,
2490 			 unsigned long flags,
2491 			 void *data)
2492 {
2493 	const struct cred *cred = current_cred();
2494 
2495 	if (flags & MS_REMOUNT)
2496 		return superblock_has_perm(cred, path->dentry->d_sb,
2497 					   FILESYSTEM__REMOUNT, NULL);
2498 	else
2499 		return path_has_perm(cred, path, FILE__MOUNTON);
2500 }
2501 
2502 static int selinux_umount(struct vfsmount *mnt, int flags)
2503 {
2504 	const struct cred *cred = current_cred();
2505 
2506 	return superblock_has_perm(cred, mnt->mnt_sb,
2507 				   FILESYSTEM__UNMOUNT, NULL);
2508 }
2509 
2510 /* inode security operations */
2511 
2512 static int selinux_inode_alloc_security(struct inode *inode)
2513 {
2514 	return inode_alloc_security(inode);
2515 }
2516 
2517 static void selinux_inode_free_security(struct inode *inode)
2518 {
2519 	inode_free_security(inode);
2520 }
2521 
2522 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2523 				       const struct qstr *qstr, char **name,
2524 				       void **value, size_t *len)
2525 {
2526 	const struct task_security_struct *tsec = current_security();
2527 	struct inode_security_struct *dsec;
2528 	struct superblock_security_struct *sbsec;
2529 	u32 sid, newsid, clen;
2530 	int rc;
2531 	char *namep = NULL, *context;
2532 
2533 	dsec = dir->i_security;
2534 	sbsec = dir->i_sb->s_security;
2535 
2536 	sid = tsec->sid;
2537 	newsid = tsec->create_sid;
2538 
2539 	if ((sbsec->flags & SE_SBINITIALIZED) &&
2540 	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
2541 		newsid = sbsec->mntpoint_sid;
2542 	else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
2543 		rc = security_transition_sid(sid, dsec->sid,
2544 					     inode_mode_to_security_class(inode->i_mode),
2545 					     qstr, &newsid);
2546 		if (rc) {
2547 			printk(KERN_WARNING "%s:  "
2548 			       "security_transition_sid failed, rc=%d (dev=%s "
2549 			       "ino=%ld)\n",
2550 			       __func__,
2551 			       -rc, inode->i_sb->s_id, inode->i_ino);
2552 			return rc;
2553 		}
2554 	}
2555 
2556 	/* Possibly defer initialization to selinux_complete_init. */
2557 	if (sbsec->flags & SE_SBINITIALIZED) {
2558 		struct inode_security_struct *isec = inode->i_security;
2559 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
2560 		isec->sid = newsid;
2561 		isec->initialized = 1;
2562 	}
2563 
2564 	if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
2565 		return -EOPNOTSUPP;
2566 
2567 	if (name) {
2568 		namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
2569 		if (!namep)
2570 			return -ENOMEM;
2571 		*name = namep;
2572 	}
2573 
2574 	if (value && len) {
2575 		rc = security_sid_to_context_force(newsid, &context, &clen);
2576 		if (rc) {
2577 			kfree(namep);
2578 			return rc;
2579 		}
2580 		*value = context;
2581 		*len = clen;
2582 	}
2583 
2584 	return 0;
2585 }
2586 
2587 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
2588 {
2589 	return may_create(dir, dentry, SECCLASS_FILE);
2590 }
2591 
2592 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2593 {
2594 	return may_link(dir, old_dentry, MAY_LINK);
2595 }
2596 
2597 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2598 {
2599 	return may_link(dir, dentry, MAY_UNLINK);
2600 }
2601 
2602 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2603 {
2604 	return may_create(dir, dentry, SECCLASS_LNK_FILE);
2605 }
2606 
2607 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
2608 {
2609 	return may_create(dir, dentry, SECCLASS_DIR);
2610 }
2611 
2612 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2613 {
2614 	return may_link(dir, dentry, MAY_RMDIR);
2615 }
2616 
2617 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
2618 {
2619 	return may_create(dir, dentry, inode_mode_to_security_class(mode));
2620 }
2621 
2622 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2623 				struct inode *new_inode, struct dentry *new_dentry)
2624 {
2625 	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2626 }
2627 
2628 static int selinux_inode_readlink(struct dentry *dentry)
2629 {
2630 	const struct cred *cred = current_cred();
2631 
2632 	return dentry_has_perm(cred, dentry, FILE__READ);
2633 }
2634 
2635 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2636 {
2637 	const struct cred *cred = current_cred();
2638 
2639 	return dentry_has_perm(cred, dentry, FILE__READ);
2640 }
2641 
2642 static noinline int audit_inode_permission(struct inode *inode,
2643 					   u32 perms, u32 audited, u32 denied,
2644 					   unsigned flags)
2645 {
2646 	struct common_audit_data ad;
2647 	struct inode_security_struct *isec = inode->i_security;
2648 	int rc;
2649 
2650 	ad.type = LSM_AUDIT_DATA_INODE;
2651 	ad.u.inode = inode;
2652 
2653 	rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
2654 			    audited, denied, &ad, flags);
2655 	if (rc)
2656 		return rc;
2657 	return 0;
2658 }
2659 
2660 static int selinux_inode_permission(struct inode *inode, int mask)
2661 {
2662 	const struct cred *cred = current_cred();
2663 	u32 perms;
2664 	bool from_access;
2665 	unsigned flags = mask & MAY_NOT_BLOCK;
2666 	struct inode_security_struct *isec;
2667 	u32 sid;
2668 	struct av_decision avd;
2669 	int rc, rc2;
2670 	u32 audited, denied;
2671 
2672 	from_access = mask & MAY_ACCESS;
2673 	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
2674 
2675 	/* No permission to check.  Existence test. */
2676 	if (!mask)
2677 		return 0;
2678 
2679 	validate_creds(cred);
2680 
2681 	if (unlikely(IS_PRIVATE(inode)))
2682 		return 0;
2683 
2684 	perms = file_mask_to_av(inode->i_mode, mask);
2685 
2686 	sid = cred_sid(cred);
2687 	isec = inode->i_security;
2688 
2689 	rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);
2690 	audited = avc_audit_required(perms, &avd, rc,
2691 				     from_access ? FILE__AUDIT_ACCESS : 0,
2692 				     &denied);
2693 	if (likely(!audited))
2694 		return rc;
2695 
2696 	rc2 = audit_inode_permission(inode, perms, audited, denied, flags);
2697 	if (rc2)
2698 		return rc2;
2699 	return rc;
2700 }
2701 
2702 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2703 {
2704 	const struct cred *cred = current_cred();
2705 	unsigned int ia_valid = iattr->ia_valid;
2706 	__u32 av = FILE__WRITE;
2707 
2708 	/* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2709 	if (ia_valid & ATTR_FORCE) {
2710 		ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2711 			      ATTR_FORCE);
2712 		if (!ia_valid)
2713 			return 0;
2714 	}
2715 
2716 	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2717 			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2718 		return dentry_has_perm(cred, dentry, FILE__SETATTR);
2719 
2720 	if (ia_valid & ATTR_SIZE)
2721 		av |= FILE__OPEN;
2722 
2723 	return dentry_has_perm(cred, dentry, av);
2724 }
2725 
2726 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2727 {
2728 	const struct cred *cred = current_cred();
2729 	struct path path;
2730 
2731 	path.dentry = dentry;
2732 	path.mnt = mnt;
2733 
2734 	return path_has_perm(cred, &path, FILE__GETATTR);
2735 }
2736 
2737 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2738 {
2739 	const struct cred *cred = current_cred();
2740 
2741 	if (!strncmp(name, XATTR_SECURITY_PREFIX,
2742 		     sizeof XATTR_SECURITY_PREFIX - 1)) {
2743 		if (!strcmp(name, XATTR_NAME_CAPS)) {
2744 			if (!capable(CAP_SETFCAP))
2745 				return -EPERM;
2746 		} else if (!capable(CAP_SYS_ADMIN)) {
2747 			/* A different attribute in the security namespace.
2748 			   Restrict to administrator. */
2749 			return -EPERM;
2750 		}
2751 	}
2752 
2753 	/* Not an attribute we recognize, so just check the
2754 	   ordinary setattr permission. */
2755 	return dentry_has_perm(cred, dentry, FILE__SETATTR);
2756 }
2757 
2758 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2759 				  const void *value, size_t size, int flags)
2760 {
2761 	struct inode *inode = dentry->d_inode;
2762 	struct inode_security_struct *isec = inode->i_security;
2763 	struct superblock_security_struct *sbsec;
2764 	struct common_audit_data ad;
2765 	u32 newsid, sid = current_sid();
2766 	int rc = 0;
2767 
2768 	if (strcmp(name, XATTR_NAME_SELINUX))
2769 		return selinux_inode_setotherxattr(dentry, name);
2770 
2771 	sbsec = inode->i_sb->s_security;
2772 	if (!(sbsec->flags & SE_SBLABELSUPP))
2773 		return -EOPNOTSUPP;
2774 
2775 	if (!inode_owner_or_capable(inode))
2776 		return -EPERM;
2777 
2778 	ad.type = LSM_AUDIT_DATA_DENTRY;
2779 	ad.u.dentry = dentry;
2780 
2781 	rc = avc_has_perm(sid, isec->sid, isec->sclass,
2782 			  FILE__RELABELFROM, &ad);
2783 	if (rc)
2784 		return rc;
2785 
2786 	rc = security_context_to_sid(value, size, &newsid);
2787 	if (rc == -EINVAL) {
2788 		if (!capable(CAP_MAC_ADMIN)) {
2789 			struct audit_buffer *ab;
2790 			size_t audit_size;
2791 			const char *str;
2792 
2793 			/* We strip a nul only if it is at the end, otherwise the
2794 			 * context contains a nul and we should audit that */
2795 			str = value;
2796 			if (str[size - 1] == '\0')
2797 				audit_size = size - 1;
2798 			else
2799 				audit_size = size;
2800 			ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
2801 			audit_log_format(ab, "op=setxattr invalid_context=");
2802 			audit_log_n_untrustedstring(ab, value, audit_size);
2803 			audit_log_end(ab);
2804 
2805 			return rc;
2806 		}
2807 		rc = security_context_to_sid_force(value, size, &newsid);
2808 	}
2809 	if (rc)
2810 		return rc;
2811 
2812 	rc = avc_has_perm(sid, newsid, isec->sclass,
2813 			  FILE__RELABELTO, &ad);
2814 	if (rc)
2815 		return rc;
2816 
2817 	rc = security_validate_transition(isec->sid, newsid, sid,
2818 					  isec->sclass);
2819 	if (rc)
2820 		return rc;
2821 
2822 	return avc_has_perm(newsid,
2823 			    sbsec->sid,
2824 			    SECCLASS_FILESYSTEM,
2825 			    FILESYSTEM__ASSOCIATE,
2826 			    &ad);
2827 }
2828 
2829 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2830 					const void *value, size_t size,
2831 					int flags)
2832 {
2833 	struct inode *inode = dentry->d_inode;
2834 	struct inode_security_struct *isec = inode->i_security;
2835 	u32 newsid;
2836 	int rc;
2837 
2838 	if (strcmp(name, XATTR_NAME_SELINUX)) {
2839 		/* Not an attribute we recognize, so nothing to do. */
2840 		return;
2841 	}
2842 
2843 	rc = security_context_to_sid_force(value, size, &newsid);
2844 	if (rc) {
2845 		printk(KERN_ERR "SELinux:  unable to map context to SID"
2846 		       "for (%s, %lu), rc=%d\n",
2847 		       inode->i_sb->s_id, inode->i_ino, -rc);
2848 		return;
2849 	}
2850 
2851 	isec->sid = newsid;
2852 	return;
2853 }
2854 
2855 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
2856 {
2857 	const struct cred *cred = current_cred();
2858 
2859 	return dentry_has_perm(cred, dentry, FILE__GETATTR);
2860 }
2861 
2862 static int selinux_inode_listxattr(struct dentry *dentry)
2863 {
2864 	const struct cred *cred = current_cred();
2865 
2866 	return dentry_has_perm(cred, dentry, FILE__GETATTR);
2867 }
2868 
2869 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
2870 {
2871 	if (strcmp(name, XATTR_NAME_SELINUX))
2872 		return selinux_inode_setotherxattr(dentry, name);
2873 
2874 	/* No one is allowed to remove a SELinux security label.
2875 	   You can change the label, but all data must be labeled. */
2876 	return -EACCES;
2877 }
2878 
2879 /*
2880  * Copy the inode security context value to the user.
2881  *
2882  * Permission check is handled by selinux_inode_getxattr hook.
2883  */
2884 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
2885 {
2886 	u32 size;
2887 	int error;
2888 	char *context = NULL;
2889 	struct inode_security_struct *isec = inode->i_security;
2890 
2891 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
2892 		return -EOPNOTSUPP;
2893 
2894 	/*
2895 	 * If the caller has CAP_MAC_ADMIN, then get the raw context
2896 	 * value even if it is not defined by current policy; otherwise,
2897 	 * use the in-core value under current policy.
2898 	 * Use the non-auditing forms of the permission checks since
2899 	 * getxattr may be called by unprivileged processes commonly
2900 	 * and lack of permission just means that we fall back to the
2901 	 * in-core context value, not a denial.
2902 	 */
2903 	error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
2904 				SECURITY_CAP_NOAUDIT);
2905 	if (!error)
2906 		error = security_sid_to_context_force(isec->sid, &context,
2907 						      &size);
2908 	else
2909 		error = security_sid_to_context(isec->sid, &context, &size);
2910 	if (error)
2911 		return error;
2912 	error = size;
2913 	if (alloc) {
2914 		*buffer = context;
2915 		goto out_nofree;
2916 	}
2917 	kfree(context);
2918 out_nofree:
2919 	return error;
2920 }
2921 
2922 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2923 				     const void *value, size_t size, int flags)
2924 {
2925 	struct inode_security_struct *isec = inode->i_security;
2926 	u32 newsid;
2927 	int rc;
2928 
2929 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
2930 		return -EOPNOTSUPP;
2931 
2932 	if (!value || !size)
2933 		return -EACCES;
2934 
2935 	rc = security_context_to_sid((void *)value, size, &newsid);
2936 	if (rc)
2937 		return rc;
2938 
2939 	isec->sid = newsid;
2940 	isec->initialized = 1;
2941 	return 0;
2942 }
2943 
2944 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2945 {
2946 	const int len = sizeof(XATTR_NAME_SELINUX);
2947 	if (buffer && len <= buffer_size)
2948 		memcpy(buffer, XATTR_NAME_SELINUX, len);
2949 	return len;
2950 }
2951 
2952 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2953 {
2954 	struct inode_security_struct *isec = inode->i_security;
2955 	*secid = isec->sid;
2956 }
2957 
2958 /* file security operations */
2959 
2960 static int selinux_revalidate_file_permission(struct file *file, int mask)
2961 {
2962 	const struct cred *cred = current_cred();
2963 	struct inode *inode = file->f_path.dentry->d_inode;
2964 
2965 	/* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2966 	if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2967 		mask |= MAY_APPEND;
2968 
2969 	return file_has_perm(cred, file,
2970 			     file_mask_to_av(inode->i_mode, mask));
2971 }
2972 
2973 static int selinux_file_permission(struct file *file, int mask)
2974 {
2975 	struct inode *inode = file->f_path.dentry->d_inode;
2976 	struct file_security_struct *fsec = file->f_security;
2977 	struct inode_security_struct *isec = inode->i_security;
2978 	u32 sid = current_sid();
2979 
2980 	if (!mask)
2981 		/* No permission to check.  Existence test. */
2982 		return 0;
2983 
2984 	if (sid == fsec->sid && fsec->isid == isec->sid &&
2985 	    fsec->pseqno == avc_policy_seqno())
2986 		/* No change since file_open check. */
2987 		return 0;
2988 
2989 	return selinux_revalidate_file_permission(file, mask);
2990 }
2991 
2992 static int selinux_file_alloc_security(struct file *file)
2993 {
2994 	return file_alloc_security(file);
2995 }
2996 
2997 static void selinux_file_free_security(struct file *file)
2998 {
2999 	file_free_security(file);
3000 }
3001 
3002 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3003 			      unsigned long arg)
3004 {
3005 	const struct cred *cred = current_cred();
3006 	int error = 0;
3007 
3008 	switch (cmd) {
3009 	case FIONREAD:
3010 	/* fall through */
3011 	case FIBMAP:
3012 	/* fall through */
3013 	case FIGETBSZ:
3014 	/* fall through */
3015 	case FS_IOC_GETFLAGS:
3016 	/* fall through */
3017 	case FS_IOC_GETVERSION:
3018 		error = file_has_perm(cred, file, FILE__GETATTR);
3019 		break;
3020 
3021 	case FS_IOC_SETFLAGS:
3022 	/* fall through */
3023 	case FS_IOC_SETVERSION:
3024 		error = file_has_perm(cred, file, FILE__SETATTR);
3025 		break;
3026 
3027 	/* sys_ioctl() checks */
3028 	case FIONBIO:
3029 	/* fall through */
3030 	case FIOASYNC:
3031 		error = file_has_perm(cred, file, 0);
3032 		break;
3033 
3034 	case KDSKBENT:
3035 	case KDSKBSENT:
3036 		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3037 					    SECURITY_CAP_AUDIT);
3038 		break;
3039 
3040 	/* default case assumes that the command will go
3041 	 * to the file's ioctl() function.
3042 	 */
3043 	default:
3044 		error = file_has_perm(cred, file, FILE__IOCTL);
3045 	}
3046 	return error;
3047 }
3048 
3049 static int default_noexec;
3050 
3051 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3052 {
3053 	const struct cred *cred = current_cred();
3054 	int rc = 0;
3055 
3056 	if (default_noexec &&
3057 	    (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
3058 		/*
3059 		 * We are making executable an anonymous mapping or a
3060 		 * private file mapping that will also be writable.
3061 		 * This has an additional check.
3062 		 */
3063 		rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
3064 		if (rc)
3065 			goto error;
3066 	}
3067 
3068 	if (file) {
3069 		/* read access is always possible with a mapping */
3070 		u32 av = FILE__READ;
3071 
3072 		/* write access only matters if the mapping is shared */
3073 		if (shared && (prot & PROT_WRITE))
3074 			av |= FILE__WRITE;
3075 
3076 		if (prot & PROT_EXEC)
3077 			av |= FILE__EXECUTE;
3078 
3079 		return file_has_perm(cred, file, av);
3080 	}
3081 
3082 error:
3083 	return rc;
3084 }
3085 
3086 static int selinux_mmap_addr(unsigned long addr)
3087 {
3088 	int rc = 0;
3089 	u32 sid = current_sid();
3090 
3091 	/*
3092 	 * notice that we are intentionally putting the SELinux check before
3093 	 * the secondary cap_file_mmap check.  This is such a likely attempt
3094 	 * at bad behaviour/exploit that we always want to get the AVC, even
3095 	 * if DAC would have also denied the operation.
3096 	 */
3097 	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3098 		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3099 				  MEMPROTECT__MMAP_ZERO, NULL);
3100 		if (rc)
3101 			return rc;
3102 	}
3103 
3104 	/* do DAC check on address space usage */
3105 	return cap_mmap_addr(addr);
3106 }
3107 
3108 static int selinux_mmap_file(struct file *file, unsigned long reqprot,
3109 			     unsigned long prot, unsigned long flags)
3110 {
3111 	if (selinux_checkreqprot)
3112 		prot = reqprot;
3113 
3114 	return file_map_prot_check(file, prot,
3115 				   (flags & MAP_TYPE) == MAP_SHARED);
3116 }
3117 
3118 static int selinux_file_mprotect(struct vm_area_struct *vma,
3119 				 unsigned long reqprot,
3120 				 unsigned long prot)
3121 {
3122 	const struct cred *cred = current_cred();
3123 
3124 	if (selinux_checkreqprot)
3125 		prot = reqprot;
3126 
3127 	if (default_noexec &&
3128 	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3129 		int rc = 0;
3130 		if (vma->vm_start >= vma->vm_mm->start_brk &&
3131 		    vma->vm_end <= vma->vm_mm->brk) {
3132 			rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3133 		} else if (!vma->vm_file &&
3134 			   vma->vm_start <= vma->vm_mm->start_stack &&
3135 			   vma->vm_end >= vma->vm_mm->start_stack) {
3136 			rc = current_has_perm(current, PROCESS__EXECSTACK);
3137 		} else if (vma->vm_file && vma->anon_vma) {
3138 			/*
3139 			 * We are making executable a file mapping that has
3140 			 * had some COW done. Since pages might have been
3141 			 * written, check ability to execute the possibly
3142 			 * modified content.  This typically should only
3143 			 * occur for text relocations.
3144 			 */
3145 			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3146 		}
3147 		if (rc)
3148 			return rc;
3149 	}
3150 
3151 	return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3152 }
3153 
3154 static int selinux_file_lock(struct file *file, unsigned int cmd)
3155 {
3156 	const struct cred *cred = current_cred();
3157 
3158 	return file_has_perm(cred, file, FILE__LOCK);
3159 }
3160 
3161 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3162 			      unsigned long arg)
3163 {
3164 	const struct cred *cred = current_cred();
3165 	int err = 0;
3166 
3167 	switch (cmd) {
3168 	case F_SETFL:
3169 		if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3170 			err = -EINVAL;
3171 			break;
3172 		}
3173 
3174 		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3175 			err = file_has_perm(cred, file, FILE__WRITE);
3176 			break;
3177 		}
3178 		/* fall through */
3179 	case F_SETOWN:
3180 	case F_SETSIG:
3181 	case F_GETFL:
3182 	case F_GETOWN:
3183 	case F_GETSIG:
3184 		/* Just check FD__USE permission */
3185 		err = file_has_perm(cred, file, 0);
3186 		break;
3187 	case F_GETLK:
3188 	case F_SETLK:
3189 	case F_SETLKW:
3190 #if BITS_PER_LONG == 32
3191 	case F_GETLK64:
3192 	case F_SETLK64:
3193 	case F_SETLKW64:
3194 #endif
3195 		if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3196 			err = -EINVAL;
3197 			break;
3198 		}
3199 		err = file_has_perm(cred, file, FILE__LOCK);
3200 		break;
3201 	}
3202 
3203 	return err;
3204 }
3205 
3206 static int selinux_file_set_fowner(struct file *file)
3207 {
3208 	struct file_security_struct *fsec;
3209 
3210 	fsec = file->f_security;
3211 	fsec->fown_sid = current_sid();
3212 
3213 	return 0;
3214 }
3215 
3216 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3217 				       struct fown_struct *fown, int signum)
3218 {
3219 	struct file *file;
3220 	u32 sid = task_sid(tsk);
3221 	u32 perm;
3222 	struct file_security_struct *fsec;
3223 
3224 	/* struct fown_struct is never outside the context of a struct file */
3225 	file = container_of(fown, struct file, f_owner);
3226 
3227 	fsec = file->f_security;
3228 
3229 	if (!signum)
3230 		perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3231 	else
3232 		perm = signal_to_av(signum);
3233 
3234 	return avc_has_perm(fsec->fown_sid, sid,
3235 			    SECCLASS_PROCESS, perm, NULL);
3236 }
3237 
3238 static int selinux_file_receive(struct file *file)
3239 {
3240 	const struct cred *cred = current_cred();
3241 
3242 	return file_has_perm(cred, file, file_to_av(file));
3243 }
3244 
3245 static int selinux_file_open(struct file *file, const struct cred *cred)
3246 {
3247 	struct file_security_struct *fsec;
3248 	struct inode_security_struct *isec;
3249 
3250 	fsec = file->f_security;
3251 	isec = file->f_path.dentry->d_inode->i_security;
3252 	/*
3253 	 * Save inode label and policy sequence number
3254 	 * at open-time so that selinux_file_permission
3255 	 * can determine whether revalidation is necessary.
3256 	 * Task label is already saved in the file security
3257 	 * struct as its SID.
3258 	 */
3259 	fsec->isid = isec->sid;
3260 	fsec->pseqno = avc_policy_seqno();
3261 	/*
3262 	 * Since the inode label or policy seqno may have changed
3263 	 * between the selinux_inode_permission check and the saving
3264 	 * of state above, recheck that access is still permitted.
3265 	 * Otherwise, access might never be revalidated against the
3266 	 * new inode label or new policy.
3267 	 * This check is not redundant - do not remove.
3268 	 */
3269 	return path_has_perm(cred, &file->f_path, open_file_to_av(file));
3270 }
3271 
3272 /* task security operations */
3273 
3274 static int selinux_task_create(unsigned long clone_flags)
3275 {
3276 	return current_has_perm(current, PROCESS__FORK);
3277 }
3278 
3279 /*
3280  * allocate the SELinux part of blank credentials
3281  */
3282 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3283 {
3284 	struct task_security_struct *tsec;
3285 
3286 	tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3287 	if (!tsec)
3288 		return -ENOMEM;
3289 
3290 	cred->security = tsec;
3291 	return 0;
3292 }
3293 
3294 /*
3295  * detach and free the LSM part of a set of credentials
3296  */
3297 static void selinux_cred_free(struct cred *cred)
3298 {
3299 	struct task_security_struct *tsec = cred->security;
3300 
3301 	/*
3302 	 * cred->security == NULL if security_cred_alloc_blank() or
3303 	 * security_prepare_creds() returned an error.
3304 	 */
3305 	BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE);
3306 	cred->security = (void *) 0x7UL;
3307 	kfree(tsec);
3308 }
3309 
3310 /*
3311  * prepare a new set of credentials for modification
3312  */
3313 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3314 				gfp_t gfp)
3315 {
3316 	const struct task_security_struct *old_tsec;
3317 	struct task_security_struct *tsec;
3318 
3319 	old_tsec = old->security;
3320 
3321 	tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3322 	if (!tsec)
3323 		return -ENOMEM;
3324 
3325 	new->security = tsec;
3326 	return 0;
3327 }
3328 
3329 /*
3330  * transfer the SELinux data to a blank set of creds
3331  */
3332 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3333 {
3334 	const struct task_security_struct *old_tsec = old->security;
3335 	struct task_security_struct *tsec = new->security;
3336 
3337 	*tsec = *old_tsec;
3338 }
3339 
3340 /*
3341  * set the security data for a kernel service
3342  * - all the creation contexts are set to unlabelled
3343  */
3344 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3345 {
3346 	struct task_security_struct *tsec = new->security;
3347 	u32 sid = current_sid();
3348 	int ret;
3349 
3350 	ret = avc_has_perm(sid, secid,
3351 			   SECCLASS_KERNEL_SERVICE,
3352 			   KERNEL_SERVICE__USE_AS_OVERRIDE,
3353 			   NULL);
3354 	if (ret == 0) {
3355 		tsec->sid = secid;
3356 		tsec->create_sid = 0;
3357 		tsec->keycreate_sid = 0;
3358 		tsec->sockcreate_sid = 0;
3359 	}
3360 	return ret;
3361 }
3362 
3363 /*
3364  * set the file creation context in a security record to the same as the
3365  * objective context of the specified inode
3366  */
3367 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3368 {
3369 	struct inode_security_struct *isec = inode->i_security;
3370 	struct task_security_struct *tsec = new->security;
3371 	u32 sid = current_sid();
3372 	int ret;
3373 
3374 	ret = avc_has_perm(sid, isec->sid,
3375 			   SECCLASS_KERNEL_SERVICE,
3376 			   KERNEL_SERVICE__CREATE_FILES_AS,
3377 			   NULL);
3378 
3379 	if (ret == 0)
3380 		tsec->create_sid = isec->sid;
3381 	return ret;
3382 }
3383 
3384 static int selinux_kernel_module_request(char *kmod_name)
3385 {
3386 	u32 sid;
3387 	struct common_audit_data ad;
3388 
3389 	sid = task_sid(current);
3390 
3391 	ad.type = LSM_AUDIT_DATA_KMOD;
3392 	ad.u.kmod_name = kmod_name;
3393 
3394 	return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
3395 			    SYSTEM__MODULE_REQUEST, &ad);
3396 }
3397 
3398 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3399 {
3400 	return current_has_perm(p, PROCESS__SETPGID);
3401 }
3402 
3403 static int selinux_task_getpgid(struct task_struct *p)
3404 {
3405 	return current_has_perm(p, PROCESS__GETPGID);
3406 }
3407 
3408 static int selinux_task_getsid(struct task_struct *p)
3409 {
3410 	return current_has_perm(p, PROCESS__GETSESSION);
3411 }
3412 
3413 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3414 {
3415 	*secid = task_sid(p);
3416 }
3417 
3418 static int selinux_task_setnice(struct task_struct *p, int nice)
3419 {
3420 	int rc;
3421 
3422 	rc = cap_task_setnice(p, nice);
3423 	if (rc)
3424 		return rc;
3425 
3426 	return current_has_perm(p, PROCESS__SETSCHED);
3427 }
3428 
3429 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3430 {
3431 	int rc;
3432 
3433 	rc = cap_task_setioprio(p, ioprio);
3434 	if (rc)
3435 		return rc;
3436 
3437 	return current_has_perm(p, PROCESS__SETSCHED);
3438 }
3439 
3440 static int selinux_task_getioprio(struct task_struct *p)
3441 {
3442 	return current_has_perm(p, PROCESS__GETSCHED);
3443 }
3444 
3445 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
3446 		struct rlimit *new_rlim)
3447 {
3448 	struct rlimit *old_rlim = p->signal->rlim + resource;
3449 
3450 	/* Control the ability to change the hard limit (whether
3451 	   lowering or raising it), so that the hard limit can
3452 	   later be used as a safe reset point for the soft limit
3453 	   upon context transitions.  See selinux_bprm_committing_creds. */
3454 	if (old_rlim->rlim_max != new_rlim->rlim_max)
3455 		return current_has_perm(p, PROCESS__SETRLIMIT);
3456 
3457 	return 0;
3458 }
3459 
3460 static int selinux_task_setscheduler(struct task_struct *p)
3461 {
3462 	int rc;
3463 
3464 	rc = cap_task_setscheduler(p);
3465 	if (rc)
3466 		return rc;
3467 
3468 	return current_has_perm(p, PROCESS__SETSCHED);
3469 }
3470 
3471 static int selinux_task_getscheduler(struct task_struct *p)
3472 {
3473 	return current_has_perm(p, PROCESS__GETSCHED);
3474 }
3475 
3476 static int selinux_task_movememory(struct task_struct *p)
3477 {
3478 	return current_has_perm(p, PROCESS__SETSCHED);
3479 }
3480 
3481 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3482 				int sig, u32 secid)
3483 {
3484 	u32 perm;
3485 	int rc;
3486 
3487 	if (!sig)
3488 		perm = PROCESS__SIGNULL; /* null signal; existence test */
3489 	else
3490 		perm = signal_to_av(sig);
3491 	if (secid)
3492 		rc = avc_has_perm(secid, task_sid(p),
3493 				  SECCLASS_PROCESS, perm, NULL);
3494 	else
3495 		rc = current_has_perm(p, perm);
3496 	return rc;
3497 }
3498 
3499 static int selinux_task_wait(struct task_struct *p)
3500 {
3501 	return task_has_perm(p, current, PROCESS__SIGCHLD);
3502 }
3503 
3504 static void selinux_task_to_inode(struct task_struct *p,
3505 				  struct inode *inode)
3506 {
3507 	struct inode_security_struct *isec = inode->i_security;
3508 	u32 sid = task_sid(p);
3509 
3510 	isec->sid = sid;
3511 	isec->initialized = 1;
3512 }
3513 
3514 /* Returns error only if unable to parse addresses */
3515 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3516 			struct common_audit_data *ad, u8 *proto)
3517 {
3518 	int offset, ihlen, ret = -EINVAL;
3519 	struct iphdr _iph, *ih;
3520 
3521 	offset = skb_network_offset(skb);
3522 	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3523 	if (ih == NULL)
3524 		goto out;
3525 
3526 	ihlen = ih->ihl * 4;
3527 	if (ihlen < sizeof(_iph))
3528 		goto out;
3529 
3530 	ad->u.net->v4info.saddr = ih->saddr;
3531 	ad->u.net->v4info.daddr = ih->daddr;
3532 	ret = 0;
3533 
3534 	if (proto)
3535 		*proto = ih->protocol;
3536 
3537 	switch (ih->protocol) {
3538 	case IPPROTO_TCP: {
3539 		struct tcphdr _tcph, *th;
3540 
3541 		if (ntohs(ih->frag_off) & IP_OFFSET)
3542 			break;
3543 
3544 		offset += ihlen;
3545 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3546 		if (th == NULL)
3547 			break;
3548 
3549 		ad->u.net->sport = th->source;
3550 		ad->u.net->dport = th->dest;
3551 		break;
3552 	}
3553 
3554 	case IPPROTO_UDP: {
3555 		struct udphdr _udph, *uh;
3556 
3557 		if (ntohs(ih->frag_off) & IP_OFFSET)
3558 			break;
3559 
3560 		offset += ihlen;
3561 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3562 		if (uh == NULL)
3563 			break;
3564 
3565 		ad->u.net->sport = uh->source;
3566 		ad->u.net->dport = uh->dest;
3567 		break;
3568 	}
3569 
3570 	case IPPROTO_DCCP: {
3571 		struct dccp_hdr _dccph, *dh;
3572 
3573 		if (ntohs(ih->frag_off) & IP_OFFSET)
3574 			break;
3575 
3576 		offset += ihlen;
3577 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3578 		if (dh == NULL)
3579 			break;
3580 
3581 		ad->u.net->sport = dh->dccph_sport;
3582 		ad->u.net->dport = dh->dccph_dport;
3583 		break;
3584 	}
3585 
3586 	default:
3587 		break;
3588 	}
3589 out:
3590 	return ret;
3591 }
3592 
3593 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3594 
3595 /* Returns error only if unable to parse addresses */
3596 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3597 			struct common_audit_data *ad, u8 *proto)
3598 {
3599 	u8 nexthdr;
3600 	int ret = -EINVAL, offset;
3601 	struct ipv6hdr _ipv6h, *ip6;
3602 	__be16 frag_off;
3603 
3604 	offset = skb_network_offset(skb);
3605 	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3606 	if (ip6 == NULL)
3607 		goto out;
3608 
3609 	ad->u.net->v6info.saddr = ip6->saddr;
3610 	ad->u.net->v6info.daddr = ip6->daddr;
3611 	ret = 0;
3612 
3613 	nexthdr = ip6->nexthdr;
3614 	offset += sizeof(_ipv6h);
3615 	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
3616 	if (offset < 0)
3617 		goto out;
3618 
3619 	if (proto)
3620 		*proto = nexthdr;
3621 
3622 	switch (nexthdr) {
3623 	case IPPROTO_TCP: {
3624 		struct tcphdr _tcph, *th;
3625 
3626 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3627 		if (th == NULL)
3628 			break;
3629 
3630 		ad->u.net->sport = th->source;
3631 		ad->u.net->dport = th->dest;
3632 		break;
3633 	}
3634 
3635 	case IPPROTO_UDP: {
3636 		struct udphdr _udph, *uh;
3637 
3638 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3639 		if (uh == NULL)
3640 			break;
3641 
3642 		ad->u.net->sport = uh->source;
3643 		ad->u.net->dport = uh->dest;
3644 		break;
3645 	}
3646 
3647 	case IPPROTO_DCCP: {
3648 		struct dccp_hdr _dccph, *dh;
3649 
3650 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3651 		if (dh == NULL)
3652 			break;
3653 
3654 		ad->u.net->sport = dh->dccph_sport;
3655 		ad->u.net->dport = dh->dccph_dport;
3656 		break;
3657 	}
3658 
3659 	/* includes fragments */
3660 	default:
3661 		break;
3662 	}
3663 out:
3664 	return ret;
3665 }
3666 
3667 #endif /* IPV6 */
3668 
3669 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3670 			     char **_addrp, int src, u8 *proto)
3671 {
3672 	char *addrp;
3673 	int ret;
3674 
3675 	switch (ad->u.net->family) {
3676 	case PF_INET:
3677 		ret = selinux_parse_skb_ipv4(skb, ad, proto);
3678 		if (ret)
3679 			goto parse_error;
3680 		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
3681 				       &ad->u.net->v4info.daddr);
3682 		goto okay;
3683 
3684 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3685 	case PF_INET6:
3686 		ret = selinux_parse_skb_ipv6(skb, ad, proto);
3687 		if (ret)
3688 			goto parse_error;
3689 		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
3690 				       &ad->u.net->v6info.daddr);
3691 		goto okay;
3692 #endif	/* IPV6 */
3693 	default:
3694 		addrp = NULL;
3695 		goto okay;
3696 	}
3697 
3698 parse_error:
3699 	printk(KERN_WARNING
3700 	       "SELinux: failure in selinux_parse_skb(),"
3701 	       " unable to parse packet\n");
3702 	return ret;
3703 
3704 okay:
3705 	if (_addrp)
3706 		*_addrp = addrp;
3707 	return 0;
3708 }
3709 
3710 /**
3711  * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3712  * @skb: the packet
3713  * @family: protocol family
3714  * @sid: the packet's peer label SID
3715  *
3716  * Description:
3717  * Check the various different forms of network peer labeling and determine
3718  * the peer label/SID for the packet; most of the magic actually occurs in
3719  * the security server function security_net_peersid_cmp().  The function
3720  * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
3721  * or -EACCES if @sid is invalid due to inconsistencies with the different
3722  * peer labels.
3723  *
3724  */
3725 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3726 {
3727 	int err;
3728 	u32 xfrm_sid;
3729 	u32 nlbl_sid;
3730 	u32 nlbl_type;
3731 
3732 	selinux_skb_xfrm_sid(skb, &xfrm_sid);
3733 	selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3734 
3735 	err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
3736 	if (unlikely(err)) {
3737 		printk(KERN_WARNING
3738 		       "SELinux: failure in selinux_skb_peerlbl_sid(),"
3739 		       " unable to determine packet's peer label\n");
3740 		return -EACCES;
3741 	}
3742 
3743 	return 0;
3744 }
3745 
3746 /* socket security operations */
3747 
3748 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
3749 				 u16 secclass, u32 *socksid)
3750 {
3751 	if (tsec->sockcreate_sid > SECSID_NULL) {
3752 		*socksid = tsec->sockcreate_sid;
3753 		return 0;
3754 	}
3755 
3756 	return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
3757 				       socksid);
3758 }
3759 
3760 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
3761 {
3762 	struct sk_security_struct *sksec = sk->sk_security;
3763 	struct common_audit_data ad;
3764 	struct lsm_network_audit net = {0,};
3765 	u32 tsid = task_sid(task);
3766 
3767 	if (sksec->sid == SECINITSID_KERNEL)
3768 		return 0;
3769 
3770 	ad.type = LSM_AUDIT_DATA_NET;
3771 	ad.u.net = &net;
3772 	ad.u.net->sk = sk;
3773 
3774 	return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
3775 }
3776 
3777 static int selinux_socket_create(int family, int type,
3778 				 int protocol, int kern)
3779 {
3780 	const struct task_security_struct *tsec = current_security();
3781 	u32 newsid;
3782 	u16 secclass;
3783 	int rc;
3784 
3785 	if (kern)
3786 		return 0;
3787 
3788 	secclass = socket_type_to_security_class(family, type, protocol);
3789 	rc = socket_sockcreate_sid(tsec, secclass, &newsid);
3790 	if (rc)
3791 		return rc;
3792 
3793 	return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
3794 }
3795 
3796 static int selinux_socket_post_create(struct socket *sock, int family,
3797 				      int type, int protocol, int kern)
3798 {
3799 	const struct task_security_struct *tsec = current_security();
3800 	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
3801 	struct sk_security_struct *sksec;
3802 	int err = 0;
3803 
3804 	isec->sclass = socket_type_to_security_class(family, type, protocol);
3805 
3806 	if (kern)
3807 		isec->sid = SECINITSID_KERNEL;
3808 	else {
3809 		err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
3810 		if (err)
3811 			return err;
3812 	}
3813 
3814 	isec->initialized = 1;
3815 
3816 	if (sock->sk) {
3817 		sksec = sock->sk->sk_security;
3818 		sksec->sid = isec->sid;
3819 		sksec->sclass = isec->sclass;
3820 		err = selinux_netlbl_socket_post_create(sock->sk, family);
3821 	}
3822 
3823 	return err;
3824 }
3825 
3826 /* Range of port numbers used to automatically bind.
3827    Need to determine whether we should perform a name_bind
3828    permission check between the socket and the port number. */
3829 
3830 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
3831 {
3832 	struct sock *sk = sock->sk;
3833 	u16 family;
3834 	int err;
3835 
3836 	err = sock_has_perm(current, sk, SOCKET__BIND);
3837 	if (err)
3838 		goto out;
3839 
3840 	/*
3841 	 * If PF_INET or PF_INET6, check name_bind permission for the port.
3842 	 * Multiple address binding for SCTP is not supported yet: we just
3843 	 * check the first address now.
3844 	 */
3845 	family = sk->sk_family;
3846 	if (family == PF_INET || family == PF_INET6) {
3847 		char *addrp;
3848 		struct sk_security_struct *sksec = sk->sk_security;
3849 		struct common_audit_data ad;
3850 		struct lsm_network_audit net = {0,};
3851 		struct sockaddr_in *addr4 = NULL;
3852 		struct sockaddr_in6 *addr6 = NULL;
3853 		unsigned short snum;
3854 		u32 sid, node_perm;
3855 
3856 		if (family == PF_INET) {
3857 			addr4 = (struct sockaddr_in *)address;
3858 			snum = ntohs(addr4->sin_port);
3859 			addrp = (char *)&addr4->sin_addr.s_addr;
3860 		} else {
3861 			addr6 = (struct sockaddr_in6 *)address;
3862 			snum = ntohs(addr6->sin6_port);
3863 			addrp = (char *)&addr6->sin6_addr.s6_addr;
3864 		}
3865 
3866 		if (snum) {
3867 			int low, high;
3868 
3869 			inet_get_local_port_range(&low, &high);
3870 
3871 			if (snum < max(PROT_SOCK, low) || snum > high) {
3872 				err = sel_netport_sid(sk->sk_protocol,
3873 						      snum, &sid);
3874 				if (err)
3875 					goto out;
3876 				ad.type = LSM_AUDIT_DATA_NET;
3877 				ad.u.net = &net;
3878 				ad.u.net->sport = htons(snum);
3879 				ad.u.net->family = family;
3880 				err = avc_has_perm(sksec->sid, sid,
3881 						   sksec->sclass,
3882 						   SOCKET__NAME_BIND, &ad);
3883 				if (err)
3884 					goto out;
3885 			}
3886 		}
3887 
3888 		switch (sksec->sclass) {
3889 		case SECCLASS_TCP_SOCKET:
3890 			node_perm = TCP_SOCKET__NODE_BIND;
3891 			break;
3892 
3893 		case SECCLASS_UDP_SOCKET:
3894 			node_perm = UDP_SOCKET__NODE_BIND;
3895 			break;
3896 
3897 		case SECCLASS_DCCP_SOCKET:
3898 			node_perm = DCCP_SOCKET__NODE_BIND;
3899 			break;
3900 
3901 		default:
3902 			node_perm = RAWIP_SOCKET__NODE_BIND;
3903 			break;
3904 		}
3905 
3906 		err = sel_netnode_sid(addrp, family, &sid);
3907 		if (err)
3908 			goto out;
3909 
3910 		ad.type = LSM_AUDIT_DATA_NET;
3911 		ad.u.net = &net;
3912 		ad.u.net->sport = htons(snum);
3913 		ad.u.net->family = family;
3914 
3915 		if (family == PF_INET)
3916 			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
3917 		else
3918 			ad.u.net->v6info.saddr = addr6->sin6_addr;
3919 
3920 		err = avc_has_perm(sksec->sid, sid,
3921 				   sksec->sclass, node_perm, &ad);
3922 		if (err)
3923 			goto out;
3924 	}
3925 out:
3926 	return err;
3927 }
3928 
3929 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
3930 {
3931 	struct sock *sk = sock->sk;
3932 	struct sk_security_struct *sksec = sk->sk_security;
3933 	int err;
3934 
3935 	err = sock_has_perm(current, sk, SOCKET__CONNECT);
3936 	if (err)
3937 		return err;
3938 
3939 	/*
3940 	 * If a TCP or DCCP socket, check name_connect permission for the port.
3941 	 */
3942 	if (sksec->sclass == SECCLASS_TCP_SOCKET ||
3943 	    sksec->sclass == SECCLASS_DCCP_SOCKET) {
3944 		struct common_audit_data ad;
3945 		struct lsm_network_audit net = {0,};
3946 		struct sockaddr_in *addr4 = NULL;
3947 		struct sockaddr_in6 *addr6 = NULL;
3948 		unsigned short snum;
3949 		u32 sid, perm;
3950 
3951 		if (sk->sk_family == PF_INET) {
3952 			addr4 = (struct sockaddr_in *)address;
3953 			if (addrlen < sizeof(struct sockaddr_in))
3954 				return -EINVAL;
3955 			snum = ntohs(addr4->sin_port);
3956 		} else {
3957 			addr6 = (struct sockaddr_in6 *)address;
3958 			if (addrlen < SIN6_LEN_RFC2133)
3959 				return -EINVAL;
3960 			snum = ntohs(addr6->sin6_port);
3961 		}
3962 
3963 		err = sel_netport_sid(sk->sk_protocol, snum, &sid);
3964 		if (err)
3965 			goto out;
3966 
3967 		perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
3968 		       TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
3969 
3970 		ad.type = LSM_AUDIT_DATA_NET;
3971 		ad.u.net = &net;
3972 		ad.u.net->dport = htons(snum);
3973 		ad.u.net->family = sk->sk_family;
3974 		err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
3975 		if (err)
3976 			goto out;
3977 	}
3978 
3979 	err = selinux_netlbl_socket_connect(sk, address);
3980 
3981 out:
3982 	return err;
3983 }
3984 
3985 static int selinux_socket_listen(struct socket *sock, int backlog)
3986 {
3987 	return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
3988 }
3989 
3990 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
3991 {
3992 	int err;
3993 	struct inode_security_struct *isec;
3994 	struct inode_security_struct *newisec;
3995 
3996 	err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
3997 	if (err)
3998 		return err;
3999 
4000 	newisec = SOCK_INODE(newsock)->i_security;
4001 
4002 	isec = SOCK_INODE(sock)->i_security;
4003 	newisec->sclass = isec->sclass;
4004 	newisec->sid = isec->sid;
4005 	newisec->initialized = 1;
4006 
4007 	return 0;
4008 }
4009 
4010 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4011 				  int size)
4012 {
4013 	return sock_has_perm(current, sock->sk, SOCKET__WRITE);
4014 }
4015 
4016 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4017 				  int size, int flags)
4018 {
4019 	return sock_has_perm(current, sock->sk, SOCKET__READ);
4020 }
4021 
4022 static int selinux_socket_getsockname(struct socket *sock)
4023 {
4024 	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4025 }
4026 
4027 static int selinux_socket_getpeername(struct socket *sock)
4028 {
4029 	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4030 }
4031 
4032 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4033 {
4034 	int err;
4035 
4036 	err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
4037 	if (err)
4038 		return err;
4039 
4040 	return selinux_netlbl_socket_setsockopt(sock, level, optname);
4041 }
4042 
4043 static int selinux_socket_getsockopt(struct socket *sock, int level,
4044 				     int optname)
4045 {
4046 	return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
4047 }
4048 
4049 static int selinux_socket_shutdown(struct socket *sock, int how)
4050 {
4051 	return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
4052 }
4053 
4054 static int selinux_socket_unix_stream_connect(struct sock *sock,
4055 					      struct sock *other,
4056 					      struct sock *newsk)
4057 {
4058 	struct sk_security_struct *sksec_sock = sock->sk_security;
4059 	struct sk_security_struct *sksec_other = other->sk_security;
4060 	struct sk_security_struct *sksec_new = newsk->sk_security;
4061 	struct common_audit_data ad;
4062 	struct lsm_network_audit net = {0,};
4063 	int err;
4064 
4065 	ad.type = LSM_AUDIT_DATA_NET;
4066 	ad.u.net = &net;
4067 	ad.u.net->sk = other;
4068 
4069 	err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
4070 			   sksec_other->sclass,
4071 			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
4072 	if (err)
4073 		return err;
4074 
4075 	/* server child socket */
4076 	sksec_new->peer_sid = sksec_sock->sid;
4077 	err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
4078 				    &sksec_new->sid);
4079 	if (err)
4080 		return err;
4081 
4082 	/* connecting socket */
4083 	sksec_sock->peer_sid = sksec_new->sid;
4084 
4085 	return 0;
4086 }
4087 
4088 static int selinux_socket_unix_may_send(struct socket *sock,
4089 					struct socket *other)
4090 {
4091 	struct sk_security_struct *ssec = sock->sk->sk_security;
4092 	struct sk_security_struct *osec = other->sk->sk_security;
4093 	struct common_audit_data ad;
4094 	struct lsm_network_audit net = {0,};
4095 
4096 	ad.type = LSM_AUDIT_DATA_NET;
4097 	ad.u.net = &net;
4098 	ad.u.net->sk = other->sk;
4099 
4100 	return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
4101 			    &ad);
4102 }
4103 
4104 static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
4105 				    u32 peer_sid,
4106 				    struct common_audit_data *ad)
4107 {
4108 	int err;
4109 	u32 if_sid;
4110 	u32 node_sid;
4111 
4112 	err = sel_netif_sid(ifindex, &if_sid);
4113 	if (err)
4114 		return err;
4115 	err = avc_has_perm(peer_sid, if_sid,
4116 			   SECCLASS_NETIF, NETIF__INGRESS, ad);
4117 	if (err)
4118 		return err;
4119 
4120 	err = sel_netnode_sid(addrp, family, &node_sid);
4121 	if (err)
4122 		return err;
4123 	return avc_has_perm(peer_sid, node_sid,
4124 			    SECCLASS_NODE, NODE__RECVFROM, ad);
4125 }
4126 
4127 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4128 				       u16 family)
4129 {
4130 	int err = 0;
4131 	struct sk_security_struct *sksec = sk->sk_security;
4132 	u32 sk_sid = sksec->sid;
4133 	struct common_audit_data ad;
4134 	struct lsm_network_audit net = {0,};
4135 	char *addrp;
4136 
4137 	ad.type = LSM_AUDIT_DATA_NET;
4138 	ad.u.net = &net;
4139 	ad.u.net->netif = skb->skb_iif;
4140 	ad.u.net->family = family;
4141 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4142 	if (err)
4143 		return err;
4144 
4145 	if (selinux_secmark_enabled()) {
4146 		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4147 				   PACKET__RECV, &ad);
4148 		if (err)
4149 			return err;
4150 	}
4151 
4152 	err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4153 	if (err)
4154 		return err;
4155 	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4156 
4157 	return err;
4158 }
4159 
4160 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4161 {
4162 	int err;
4163 	struct sk_security_struct *sksec = sk->sk_security;
4164 	u16 family = sk->sk_family;
4165 	u32 sk_sid = sksec->sid;
4166 	struct common_audit_data ad;
4167 	struct lsm_network_audit net = {0,};
4168 	char *addrp;
4169 	u8 secmark_active;
4170 	u8 peerlbl_active;
4171 
4172 	if (family != PF_INET && family != PF_INET6)
4173 		return 0;
4174 
4175 	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
4176 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4177 		family = PF_INET;
4178 
4179 	/* If any sort of compatibility mode is enabled then handoff processing
4180 	 * to the selinux_sock_rcv_skb_compat() function to deal with the
4181 	 * special handling.  We do this in an attempt to keep this function
4182 	 * as fast and as clean as possible. */
4183 	if (!selinux_policycap_netpeer)
4184 		return selinux_sock_rcv_skb_compat(sk, skb, family);
4185 
4186 	secmark_active = selinux_secmark_enabled();
4187 	peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4188 	if (!secmark_active && !peerlbl_active)
4189 		return 0;
4190 
4191 	ad.type = LSM_AUDIT_DATA_NET;
4192 	ad.u.net = &net;
4193 	ad.u.net->netif = skb->skb_iif;
4194 	ad.u.net->family = family;
4195 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4196 	if (err)
4197 		return err;
4198 
4199 	if (peerlbl_active) {
4200 		u32 peer_sid;
4201 
4202 		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4203 		if (err)
4204 			return err;
4205 		err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
4206 					       peer_sid, &ad);
4207 		if (err) {
4208 			selinux_netlbl_err(skb, err, 0);
4209 			return err;
4210 		}
4211 		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4212 				   PEER__RECV, &ad);
4213 		if (err)
4214 			selinux_netlbl_err(skb, err, 0);
4215 	}
4216 
4217 	if (secmark_active) {
4218 		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4219 				   PACKET__RECV, &ad);
4220 		if (err)
4221 			return err;
4222 	}
4223 
4224 	return err;
4225 }
4226 
4227 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4228 					    int __user *optlen, unsigned len)
4229 {
4230 	int err = 0;
4231 	char *scontext;
4232 	u32 scontext_len;
4233 	struct sk_security_struct *sksec = sock->sk->sk_security;
4234 	u32 peer_sid = SECSID_NULL;
4235 
4236 	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4237 	    sksec->sclass == SECCLASS_TCP_SOCKET)
4238 		peer_sid = sksec->peer_sid;
4239 	if (peer_sid == SECSID_NULL)
4240 		return -ENOPROTOOPT;
4241 
4242 	err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4243 	if (err)
4244 		return err;
4245 
4246 	if (scontext_len > len) {
4247 		err = -ERANGE;
4248 		goto out_len;
4249 	}
4250 
4251 	if (copy_to_user(optval, scontext, scontext_len))
4252 		err = -EFAULT;
4253 
4254 out_len:
4255 	if (put_user(scontext_len, optlen))
4256 		err = -EFAULT;
4257 	kfree(scontext);
4258 	return err;
4259 }
4260 
4261 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4262 {
4263 	u32 peer_secid = SECSID_NULL;
4264 	u16 family;
4265 
4266 	if (skb && skb->protocol == htons(ETH_P_IP))
4267 		family = PF_INET;
4268 	else if (skb && skb->protocol == htons(ETH_P_IPV6))
4269 		family = PF_INET6;
4270 	else if (sock)
4271 		family = sock->sk->sk_family;
4272 	else
4273 		goto out;
4274 
4275 	if (sock && family == PF_UNIX)
4276 		selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4277 	else if (skb)
4278 		selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4279 
4280 out:
4281 	*secid = peer_secid;
4282 	if (peer_secid == SECSID_NULL)
4283 		return -EINVAL;
4284 	return 0;
4285 }
4286 
4287 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4288 {
4289 	struct sk_security_struct *sksec;
4290 
4291 	sksec = kzalloc(sizeof(*sksec), priority);
4292 	if (!sksec)
4293 		return -ENOMEM;
4294 
4295 	sksec->peer_sid = SECINITSID_UNLABELED;
4296 	sksec->sid = SECINITSID_UNLABELED;
4297 	selinux_netlbl_sk_security_reset(sksec);
4298 	sk->sk_security = sksec;
4299 
4300 	return 0;
4301 }
4302 
4303 static void selinux_sk_free_security(struct sock *sk)
4304 {
4305 	struct sk_security_struct *sksec = sk->sk_security;
4306 
4307 	sk->sk_security = NULL;
4308 	selinux_netlbl_sk_security_free(sksec);
4309 	kfree(sksec);
4310 }
4311 
4312 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4313 {
4314 	struct sk_security_struct *sksec = sk->sk_security;
4315 	struct sk_security_struct *newsksec = newsk->sk_security;
4316 
4317 	newsksec->sid = sksec->sid;
4318 	newsksec->peer_sid = sksec->peer_sid;
4319 	newsksec->sclass = sksec->sclass;
4320 
4321 	selinux_netlbl_sk_security_reset(newsksec);
4322 }
4323 
4324 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4325 {
4326 	if (!sk)
4327 		*secid = SECINITSID_ANY_SOCKET;
4328 	else {
4329 		struct sk_security_struct *sksec = sk->sk_security;
4330 
4331 		*secid = sksec->sid;
4332 	}
4333 }
4334 
4335 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4336 {
4337 	struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
4338 	struct sk_security_struct *sksec = sk->sk_security;
4339 
4340 	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4341 	    sk->sk_family == PF_UNIX)
4342 		isec->sid = sksec->sid;
4343 	sksec->sclass = isec->sclass;
4344 }
4345 
4346 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4347 				     struct request_sock *req)
4348 {
4349 	struct sk_security_struct *sksec = sk->sk_security;
4350 	int err;
4351 	u16 family = sk->sk_family;
4352 	u32 newsid;
4353 	u32 peersid;
4354 
4355 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
4356 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4357 		family = PF_INET;
4358 
4359 	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4360 	if (err)
4361 		return err;
4362 	if (peersid == SECSID_NULL) {
4363 		req->secid = sksec->sid;
4364 		req->peer_secid = SECSID_NULL;
4365 	} else {
4366 		err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
4367 		if (err)
4368 			return err;
4369 		req->secid = newsid;
4370 		req->peer_secid = peersid;
4371 	}
4372 
4373 	return selinux_netlbl_inet_conn_request(req, family);
4374 }
4375 
4376 static void selinux_inet_csk_clone(struct sock *newsk,
4377 				   const struct request_sock *req)
4378 {
4379 	struct sk_security_struct *newsksec = newsk->sk_security;
4380 
4381 	newsksec->sid = req->secid;
4382 	newsksec->peer_sid = req->peer_secid;
4383 	/* NOTE: Ideally, we should also get the isec->sid for the
4384 	   new socket in sync, but we don't have the isec available yet.
4385 	   So we will wait until sock_graft to do it, by which
4386 	   time it will have been created and available. */
4387 
4388 	/* We don't need to take any sort of lock here as we are the only
4389 	 * thread with access to newsksec */
4390 	selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4391 }
4392 
4393 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4394 {
4395 	u16 family = sk->sk_family;
4396 	struct sk_security_struct *sksec = sk->sk_security;
4397 
4398 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
4399 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4400 		family = PF_INET;
4401 
4402 	selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4403 }
4404 
4405 static int selinux_secmark_relabel_packet(u32 sid)
4406 {
4407 	const struct task_security_struct *__tsec;
4408 	u32 tsid;
4409 
4410 	__tsec = current_security();
4411 	tsid = __tsec->sid;
4412 
4413 	return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
4414 }
4415 
4416 static void selinux_secmark_refcount_inc(void)
4417 {
4418 	atomic_inc(&selinux_secmark_refcount);
4419 }
4420 
4421 static void selinux_secmark_refcount_dec(void)
4422 {
4423 	atomic_dec(&selinux_secmark_refcount);
4424 }
4425 
4426 static void selinux_req_classify_flow(const struct request_sock *req,
4427 				      struct flowi *fl)
4428 {
4429 	fl->flowi_secid = req->secid;
4430 }
4431 
4432 static int selinux_tun_dev_create(void)
4433 {
4434 	u32 sid = current_sid();
4435 
4436 	/* we aren't taking into account the "sockcreate" SID since the socket
4437 	 * that is being created here is not a socket in the traditional sense,
4438 	 * instead it is a private sock, accessible only to the kernel, and
4439 	 * representing a wide range of network traffic spanning multiple
4440 	 * connections unlike traditional sockets - check the TUN driver to
4441 	 * get a better understanding of why this socket is special */
4442 
4443 	return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4444 			    NULL);
4445 }
4446 
4447 static void selinux_tun_dev_post_create(struct sock *sk)
4448 {
4449 	struct sk_security_struct *sksec = sk->sk_security;
4450 
4451 	/* we don't currently perform any NetLabel based labeling here and it
4452 	 * isn't clear that we would want to do so anyway; while we could apply
4453 	 * labeling without the support of the TUN user the resulting labeled
4454 	 * traffic from the other end of the connection would almost certainly
4455 	 * cause confusion to the TUN user that had no idea network labeling
4456 	 * protocols were being used */
4457 
4458 	/* see the comments in selinux_tun_dev_create() about why we don't use
4459 	 * the sockcreate SID here */
4460 
4461 	sksec->sid = current_sid();
4462 	sksec->sclass = SECCLASS_TUN_SOCKET;
4463 }
4464 
4465 static int selinux_tun_dev_attach(struct sock *sk)
4466 {
4467 	struct sk_security_struct *sksec = sk->sk_security;
4468 	u32 sid = current_sid();
4469 	int err;
4470 
4471 	err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET,
4472 			   TUN_SOCKET__RELABELFROM, NULL);
4473 	if (err)
4474 		return err;
4475 	err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4476 			   TUN_SOCKET__RELABELTO, NULL);
4477 	if (err)
4478 		return err;
4479 
4480 	sksec->sid = sid;
4481 
4482 	return 0;
4483 }
4484 
4485 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4486 {
4487 	int err = 0;
4488 	u32 perm;
4489 	struct nlmsghdr *nlh;
4490 	struct sk_security_struct *sksec = sk->sk_security;
4491 
4492 	if (skb->len < NLMSG_SPACE(0)) {
4493 		err = -EINVAL;
4494 		goto out;
4495 	}
4496 	nlh = nlmsg_hdr(skb);
4497 
4498 	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
4499 	if (err) {
4500 		if (err == -EINVAL) {
4501 			audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
4502 				  "SELinux:  unrecognized netlink message"
4503 				  " type=%hu for sclass=%hu\n",
4504 				  nlh->nlmsg_type, sksec->sclass);
4505 			if (!selinux_enforcing || security_get_allow_unknown())
4506 				err = 0;
4507 		}
4508 
4509 		/* Ignore */
4510 		if (err == -ENOENT)
4511 			err = 0;
4512 		goto out;
4513 	}
4514 
4515 	err = sock_has_perm(current, sk, perm);
4516 out:
4517 	return err;
4518 }
4519 
4520 #ifdef CONFIG_NETFILTER
4521 
4522 static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
4523 				       u16 family)
4524 {
4525 	int err;
4526 	char *addrp;
4527 	u32 peer_sid;
4528 	struct common_audit_data ad;
4529 	struct lsm_network_audit net = {0,};
4530 	u8 secmark_active;
4531 	u8 netlbl_active;
4532 	u8 peerlbl_active;
4533 
4534 	if (!selinux_policycap_netpeer)
4535 		return NF_ACCEPT;
4536 
4537 	secmark_active = selinux_secmark_enabled();
4538 	netlbl_active = netlbl_enabled();
4539 	peerlbl_active = netlbl_active || selinux_xfrm_enabled();
4540 	if (!secmark_active && !peerlbl_active)
4541 		return NF_ACCEPT;
4542 
4543 	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
4544 		return NF_DROP;
4545 
4546 	ad.type = LSM_AUDIT_DATA_NET;
4547 	ad.u.net = &net;
4548 	ad.u.net->netif = ifindex;
4549 	ad.u.net->family = family;
4550 	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
4551 		return NF_DROP;
4552 
4553 	if (peerlbl_active) {
4554 		err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
4555 					       peer_sid, &ad);
4556 		if (err) {
4557 			selinux_netlbl_err(skb, err, 1);
4558 			return NF_DROP;
4559 		}
4560 	}
4561 
4562 	if (secmark_active)
4563 		if (avc_has_perm(peer_sid, skb->secmark,
4564 				 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
4565 			return NF_DROP;
4566 
4567 	if (netlbl_active)
4568 		/* we do this in the FORWARD path and not the POST_ROUTING
4569 		 * path because we want to make sure we apply the necessary
4570 		 * labeling before IPsec is applied so we can leverage AH
4571 		 * protection */
4572 		if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
4573 			return NF_DROP;
4574 
4575 	return NF_ACCEPT;
4576 }
4577 
4578 static unsigned int selinux_ipv4_forward(unsigned int hooknum,
4579 					 struct sk_buff *skb,
4580 					 const struct net_device *in,
4581 					 const struct net_device *out,
4582 					 int (*okfn)(struct sk_buff *))
4583 {
4584 	return selinux_ip_forward(skb, in->ifindex, PF_INET);
4585 }
4586 
4587 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4588 static unsigned int selinux_ipv6_forward(unsigned int hooknum,
4589 					 struct sk_buff *skb,
4590 					 const struct net_device *in,
4591 					 const struct net_device *out,
4592 					 int (*okfn)(struct sk_buff *))
4593 {
4594 	return selinux_ip_forward(skb, in->ifindex, PF_INET6);
4595 }
4596 #endif	/* IPV6 */
4597 
4598 static unsigned int selinux_ip_output(struct sk_buff *skb,
4599 				      u16 family)
4600 {
4601 	u32 sid;
4602 
4603 	if (!netlbl_enabled())
4604 		return NF_ACCEPT;
4605 
4606 	/* we do this in the LOCAL_OUT path and not the POST_ROUTING path
4607 	 * because we want to make sure we apply the necessary labeling
4608 	 * before IPsec is applied so we can leverage AH protection */
4609 	if (skb->sk) {
4610 		struct sk_security_struct *sksec = skb->sk->sk_security;
4611 		sid = sksec->sid;
4612 	} else
4613 		sid = SECINITSID_KERNEL;
4614 	if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
4615 		return NF_DROP;
4616 
4617 	return NF_ACCEPT;
4618 }
4619 
4620 static unsigned int selinux_ipv4_output(unsigned int hooknum,
4621 					struct sk_buff *skb,
4622 					const struct net_device *in,
4623 					const struct net_device *out,
4624 					int (*okfn)(struct sk_buff *))
4625 {
4626 	return selinux_ip_output(skb, PF_INET);
4627 }
4628 
4629 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
4630 						int ifindex,
4631 						u16 family)
4632 {
4633 	struct sock *sk = skb->sk;
4634 	struct sk_security_struct *sksec;
4635 	struct common_audit_data ad;
4636 	struct lsm_network_audit net = {0,};
4637 	char *addrp;
4638 	u8 proto;
4639 
4640 	if (sk == NULL)
4641 		return NF_ACCEPT;
4642 	sksec = sk->sk_security;
4643 
4644 	ad.type = LSM_AUDIT_DATA_NET;
4645 	ad.u.net = &net;
4646 	ad.u.net->netif = ifindex;
4647 	ad.u.net->family = family;
4648 	if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
4649 		return NF_DROP;
4650 
4651 	if (selinux_secmark_enabled())
4652 		if (avc_has_perm(sksec->sid, skb->secmark,
4653 				 SECCLASS_PACKET, PACKET__SEND, &ad))
4654 			return NF_DROP_ERR(-ECONNREFUSED);
4655 
4656 	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
4657 		return NF_DROP_ERR(-ECONNREFUSED);
4658 
4659 	return NF_ACCEPT;
4660 }
4661 
4662 static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
4663 					 u16 family)
4664 {
4665 	u32 secmark_perm;
4666 	u32 peer_sid;
4667 	struct sock *sk;
4668 	struct common_audit_data ad;
4669 	struct lsm_network_audit net = {0,};
4670 	char *addrp;
4671 	u8 secmark_active;
4672 	u8 peerlbl_active;
4673 
4674 	/* If any sort of compatibility mode is enabled then handoff processing
4675 	 * to the selinux_ip_postroute_compat() function to deal with the
4676 	 * special handling.  We do this in an attempt to keep this function
4677 	 * as fast and as clean as possible. */
4678 	if (!selinux_policycap_netpeer)
4679 		return selinux_ip_postroute_compat(skb, ifindex, family);
4680 #ifdef CONFIG_XFRM
4681 	/* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
4682 	 * packet transformation so allow the packet to pass without any checks
4683 	 * since we'll have another chance to perform access control checks
4684 	 * when the packet is on it's final way out.
4685 	 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
4686 	 *       is NULL, in this case go ahead and apply access control. */
4687 	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
4688 		return NF_ACCEPT;
4689 #endif
4690 	secmark_active = selinux_secmark_enabled();
4691 	peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4692 	if (!secmark_active && !peerlbl_active)
4693 		return NF_ACCEPT;
4694 
4695 	/* if the packet is being forwarded then get the peer label from the
4696 	 * packet itself; otherwise check to see if it is from a local
4697 	 * application or the kernel, if from an application get the peer label
4698 	 * from the sending socket, otherwise use the kernel's sid */
4699 	sk = skb->sk;
4700 	if (sk == NULL) {
4701 		if (skb->skb_iif) {
4702 			secmark_perm = PACKET__FORWARD_OUT;
4703 			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4704 				return NF_DROP;
4705 		} else {
4706 			secmark_perm = PACKET__SEND;
4707 			peer_sid = SECINITSID_KERNEL;
4708 		}
4709 	} else {
4710 		struct sk_security_struct *sksec = sk->sk_security;
4711 		peer_sid = sksec->sid;
4712 		secmark_perm = PACKET__SEND;
4713 	}
4714 
4715 	ad.type = LSM_AUDIT_DATA_NET;
4716 	ad.u.net = &net;
4717 	ad.u.net->netif = ifindex;
4718 	ad.u.net->family = family;
4719 	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4720 		return NF_DROP;
4721 
4722 	if (secmark_active)
4723 		if (avc_has_perm(peer_sid, skb->secmark,
4724 				 SECCLASS_PACKET, secmark_perm, &ad))
4725 			return NF_DROP_ERR(-ECONNREFUSED);
4726 
4727 	if (peerlbl_active) {
4728 		u32 if_sid;
4729 		u32 node_sid;
4730 
4731 		if (sel_netif_sid(ifindex, &if_sid))
4732 			return NF_DROP;
4733 		if (avc_has_perm(peer_sid, if_sid,
4734 				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
4735 			return NF_DROP_ERR(-ECONNREFUSED);
4736 
4737 		if (sel_netnode_sid(addrp, family, &node_sid))
4738 			return NF_DROP;
4739 		if (avc_has_perm(peer_sid, node_sid,
4740 				 SECCLASS_NODE, NODE__SENDTO, &ad))
4741 			return NF_DROP_ERR(-ECONNREFUSED);
4742 	}
4743 
4744 	return NF_ACCEPT;
4745 }
4746 
4747 static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
4748 					   struct sk_buff *skb,
4749 					   const struct net_device *in,
4750 					   const struct net_device *out,
4751 					   int (*okfn)(struct sk_buff *))
4752 {
4753 	return selinux_ip_postroute(skb, out->ifindex, PF_INET);
4754 }
4755 
4756 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4757 static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
4758 					   struct sk_buff *skb,
4759 					   const struct net_device *in,
4760 					   const struct net_device *out,
4761 					   int (*okfn)(struct sk_buff *))
4762 {
4763 	return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
4764 }
4765 #endif	/* IPV6 */
4766 
4767 #endif	/* CONFIG_NETFILTER */
4768 
4769 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
4770 {
4771 	int err;
4772 
4773 	err = cap_netlink_send(sk, skb);
4774 	if (err)
4775 		return err;
4776 
4777 	return selinux_nlmsg_perm(sk, skb);
4778 }
4779 
4780 static int ipc_alloc_security(struct task_struct *task,
4781 			      struct kern_ipc_perm *perm,
4782 			      u16 sclass)
4783 {
4784 	struct ipc_security_struct *isec;
4785 	u32 sid;
4786 
4787 	isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
4788 	if (!isec)
4789 		return -ENOMEM;
4790 
4791 	sid = task_sid(task);
4792 	isec->sclass = sclass;
4793 	isec->sid = sid;
4794 	perm->security = isec;
4795 
4796 	return 0;
4797 }
4798 
4799 static void ipc_free_security(struct kern_ipc_perm *perm)
4800 {
4801 	struct ipc_security_struct *isec = perm->security;
4802 	perm->security = NULL;
4803 	kfree(isec);
4804 }
4805 
4806 static int msg_msg_alloc_security(struct msg_msg *msg)
4807 {
4808 	struct msg_security_struct *msec;
4809 
4810 	msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
4811 	if (!msec)
4812 		return -ENOMEM;
4813 
4814 	msec->sid = SECINITSID_UNLABELED;
4815 	msg->security = msec;
4816 
4817 	return 0;
4818 }
4819 
4820 static void msg_msg_free_security(struct msg_msg *msg)
4821 {
4822 	struct msg_security_struct *msec = msg->security;
4823 
4824 	msg->security = NULL;
4825 	kfree(msec);
4826 }
4827 
4828 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
4829 			u32 perms)
4830 {
4831 	struct ipc_security_struct *isec;
4832 	struct common_audit_data ad;
4833 	u32 sid = current_sid();
4834 
4835 	isec = ipc_perms->security;
4836 
4837 	ad.type = LSM_AUDIT_DATA_IPC;
4838 	ad.u.ipc_id = ipc_perms->key;
4839 
4840 	return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
4841 }
4842 
4843 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
4844 {
4845 	return msg_msg_alloc_security(msg);
4846 }
4847 
4848 static void selinux_msg_msg_free_security(struct msg_msg *msg)
4849 {
4850 	msg_msg_free_security(msg);
4851 }
4852 
4853 /* message queue security operations */
4854 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
4855 {
4856 	struct ipc_security_struct *isec;
4857 	struct common_audit_data ad;
4858 	u32 sid = current_sid();
4859 	int rc;
4860 
4861 	rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
4862 	if (rc)
4863 		return rc;
4864 
4865 	isec = msq->q_perm.security;
4866 
4867 	ad.type = LSM_AUDIT_DATA_IPC;
4868 	ad.u.ipc_id = msq->q_perm.key;
4869 
4870 	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4871 			  MSGQ__CREATE, &ad);
4872 	if (rc) {
4873 		ipc_free_security(&msq->q_perm);
4874 		return rc;
4875 	}
4876 	return 0;
4877 }
4878 
4879 static void selinux_msg_queue_free_security(struct msg_queue *msq)
4880 {
4881 	ipc_free_security(&msq->q_perm);
4882 }
4883 
4884 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
4885 {
4886 	struct ipc_security_struct *isec;
4887 	struct common_audit_data ad;
4888 	u32 sid = current_sid();
4889 
4890 	isec = msq->q_perm.security;
4891 
4892 	ad.type = LSM_AUDIT_DATA_IPC;
4893 	ad.u.ipc_id = msq->q_perm.key;
4894 
4895 	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4896 			    MSGQ__ASSOCIATE, &ad);
4897 }
4898 
4899 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
4900 {
4901 	int err;
4902 	int perms;
4903 
4904 	switch (cmd) {
4905 	case IPC_INFO:
4906 	case MSG_INFO:
4907 		/* No specific object, just general system-wide information. */
4908 		return task_has_system(current, SYSTEM__IPC_INFO);
4909 	case IPC_STAT:
4910 	case MSG_STAT:
4911 		perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
4912 		break;
4913 	case IPC_SET:
4914 		perms = MSGQ__SETATTR;
4915 		break;
4916 	case IPC_RMID:
4917 		perms = MSGQ__DESTROY;
4918 		break;
4919 	default:
4920 		return 0;
4921 	}
4922 
4923 	err = ipc_has_perm(&msq->q_perm, perms);
4924 	return err;
4925 }
4926 
4927 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
4928 {
4929 	struct ipc_security_struct *isec;
4930 	struct msg_security_struct *msec;
4931 	struct common_audit_data ad;
4932 	u32 sid = current_sid();
4933 	int rc;
4934 
4935 	isec = msq->q_perm.security;
4936 	msec = msg->security;
4937 
4938 	/*
4939 	 * First time through, need to assign label to the message
4940 	 */
4941 	if (msec->sid == SECINITSID_UNLABELED) {
4942 		/*
4943 		 * Compute new sid based on current process and
4944 		 * message queue this message will be stored in
4945 		 */
4946 		rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
4947 					     NULL, &msec->sid);
4948 		if (rc)
4949 			return rc;
4950 	}
4951 
4952 	ad.type = LSM_AUDIT_DATA_IPC;
4953 	ad.u.ipc_id = msq->q_perm.key;
4954 
4955 	/* Can this process write to the queue? */
4956 	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4957 			  MSGQ__WRITE, &ad);
4958 	if (!rc)
4959 		/* Can this process send the message */
4960 		rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
4961 				  MSG__SEND, &ad);
4962 	if (!rc)
4963 		/* Can the message be put in the queue? */
4964 		rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
4965 				  MSGQ__ENQUEUE, &ad);
4966 
4967 	return rc;
4968 }
4969 
4970 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
4971 				    struct task_struct *target,
4972 				    long type, int mode)
4973 {
4974 	struct ipc_security_struct *isec;
4975 	struct msg_security_struct *msec;
4976 	struct common_audit_data ad;
4977 	u32 sid = task_sid(target);
4978 	int rc;
4979 
4980 	isec = msq->q_perm.security;
4981 	msec = msg->security;
4982 
4983 	ad.type = LSM_AUDIT_DATA_IPC;
4984 	ad.u.ipc_id = msq->q_perm.key;
4985 
4986 	rc = avc_has_perm(sid, isec->sid,
4987 			  SECCLASS_MSGQ, MSGQ__READ, &ad);
4988 	if (!rc)
4989 		rc = avc_has_perm(sid, msec->sid,
4990 				  SECCLASS_MSG, MSG__RECEIVE, &ad);
4991 	return rc;
4992 }
4993 
4994 /* Shared Memory security operations */
4995 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
4996 {
4997 	struct ipc_security_struct *isec;
4998 	struct common_audit_data ad;
4999 	u32 sid = current_sid();
5000 	int rc;
5001 
5002 	rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
5003 	if (rc)
5004 		return rc;
5005 
5006 	isec = shp->shm_perm.security;
5007 
5008 	ad.type = LSM_AUDIT_DATA_IPC;
5009 	ad.u.ipc_id = shp->shm_perm.key;
5010 
5011 	rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5012 			  SHM__CREATE, &ad);
5013 	if (rc) {
5014 		ipc_free_security(&shp->shm_perm);
5015 		return rc;
5016 	}
5017 	return 0;
5018 }
5019 
5020 static void selinux_shm_free_security(struct shmid_kernel *shp)
5021 {
5022 	ipc_free_security(&shp->shm_perm);
5023 }
5024 
5025 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
5026 {
5027 	struct ipc_security_struct *isec;
5028 	struct common_audit_data ad;
5029 	u32 sid = current_sid();
5030 
5031 	isec = shp->shm_perm.security;
5032 
5033 	ad.type = LSM_AUDIT_DATA_IPC;
5034 	ad.u.ipc_id = shp->shm_perm.key;
5035 
5036 	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5037 			    SHM__ASSOCIATE, &ad);
5038 }
5039 
5040 /* Note, at this point, shp is locked down */
5041 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
5042 {
5043 	int perms;
5044 	int err;
5045 
5046 	switch (cmd) {
5047 	case IPC_INFO:
5048 	case SHM_INFO:
5049 		/* No specific object, just general system-wide information. */
5050 		return task_has_system(current, SYSTEM__IPC_INFO);
5051 	case IPC_STAT:
5052 	case SHM_STAT:
5053 		perms = SHM__GETATTR | SHM__ASSOCIATE;
5054 		break;
5055 	case IPC_SET:
5056 		perms = SHM__SETATTR;
5057 		break;
5058 	case SHM_LOCK:
5059 	case SHM_UNLOCK:
5060 		perms = SHM__LOCK;
5061 		break;
5062 	case IPC_RMID:
5063 		perms = SHM__DESTROY;
5064 		break;
5065 	default:
5066 		return 0;
5067 	}
5068 
5069 	err = ipc_has_perm(&shp->shm_perm, perms);
5070 	return err;
5071 }
5072 
5073 static int selinux_shm_shmat(struct shmid_kernel *shp,
5074 			     char __user *shmaddr, int shmflg)
5075 {
5076 	u32 perms;
5077 
5078 	if (shmflg & SHM_RDONLY)
5079 		perms = SHM__READ;
5080 	else
5081 		perms = SHM__READ | SHM__WRITE;
5082 
5083 	return ipc_has_perm(&shp->shm_perm, perms);
5084 }
5085 
5086 /* Semaphore security operations */
5087 static int selinux_sem_alloc_security(struct sem_array *sma)
5088 {
5089 	struct ipc_security_struct *isec;
5090 	struct common_audit_data ad;
5091 	u32 sid = current_sid();
5092 	int rc;
5093 
5094 	rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
5095 	if (rc)
5096 		return rc;
5097 
5098 	isec = sma->sem_perm.security;
5099 
5100 	ad.type = LSM_AUDIT_DATA_IPC;
5101 	ad.u.ipc_id = sma->sem_perm.key;
5102 
5103 	rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5104 			  SEM__CREATE, &ad);
5105 	if (rc) {
5106 		ipc_free_security(&sma->sem_perm);
5107 		return rc;
5108 	}
5109 	return 0;
5110 }
5111 
5112 static void selinux_sem_free_security(struct sem_array *sma)
5113 {
5114 	ipc_free_security(&sma->sem_perm);
5115 }
5116 
5117 static int selinux_sem_associate(struct sem_array *sma, int semflg)
5118 {
5119 	struct ipc_security_struct *isec;
5120 	struct common_audit_data ad;
5121 	u32 sid = current_sid();
5122 
5123 	isec = sma->sem_perm.security;
5124 
5125 	ad.type = LSM_AUDIT_DATA_IPC;
5126 	ad.u.ipc_id = sma->sem_perm.key;
5127 
5128 	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5129 			    SEM__ASSOCIATE, &ad);
5130 }
5131 
5132 /* Note, at this point, sma is locked down */
5133 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5134 {
5135 	int err;
5136 	u32 perms;
5137 
5138 	switch (cmd) {
5139 	case IPC_INFO:
5140 	case SEM_INFO:
5141 		/* No specific object, just general system-wide information. */
5142 		return task_has_system(current, SYSTEM__IPC_INFO);
5143 	case GETPID:
5144 	case GETNCNT:
5145 	case GETZCNT:
5146 		perms = SEM__GETATTR;
5147 		break;
5148 	case GETVAL:
5149 	case GETALL:
5150 		perms = SEM__READ;
5151 		break;
5152 	case SETVAL:
5153 	case SETALL:
5154 		perms = SEM__WRITE;
5155 		break;
5156 	case IPC_RMID:
5157 		perms = SEM__DESTROY;
5158 		break;
5159 	case IPC_SET:
5160 		perms = SEM__SETATTR;
5161 		break;
5162 	case IPC_STAT:
5163 	case SEM_STAT:
5164 		perms = SEM__GETATTR | SEM__ASSOCIATE;
5165 		break;
5166 	default:
5167 		return 0;
5168 	}
5169 
5170 	err = ipc_has_perm(&sma->sem_perm, perms);
5171 	return err;
5172 }
5173 
5174 static int selinux_sem_semop(struct sem_array *sma,
5175 			     struct sembuf *sops, unsigned nsops, int alter)
5176 {
5177 	u32 perms;
5178 
5179 	if (alter)
5180 		perms = SEM__READ | SEM__WRITE;
5181 	else
5182 		perms = SEM__READ;
5183 
5184 	return ipc_has_perm(&sma->sem_perm, perms);
5185 }
5186 
5187 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5188 {
5189 	u32 av = 0;
5190 
5191 	av = 0;
5192 	if (flag & S_IRUGO)
5193 		av |= IPC__UNIX_READ;
5194 	if (flag & S_IWUGO)
5195 		av |= IPC__UNIX_WRITE;
5196 
5197 	if (av == 0)
5198 		return 0;
5199 
5200 	return ipc_has_perm(ipcp, av);
5201 }
5202 
5203 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5204 {
5205 	struct ipc_security_struct *isec = ipcp->security;
5206 	*secid = isec->sid;
5207 }
5208 
5209 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5210 {
5211 	if (inode)
5212 		inode_doinit_with_dentry(inode, dentry);
5213 }
5214 
5215 static int selinux_getprocattr(struct task_struct *p,
5216 			       char *name, char **value)
5217 {
5218 	const struct task_security_struct *__tsec;
5219 	u32 sid;
5220 	int error;
5221 	unsigned len;
5222 
5223 	if (current != p) {
5224 		error = current_has_perm(p, PROCESS__GETATTR);
5225 		if (error)
5226 			return error;
5227 	}
5228 
5229 	rcu_read_lock();
5230 	__tsec = __task_cred(p)->security;
5231 
5232 	if (!strcmp(name, "current"))
5233 		sid = __tsec->sid;
5234 	else if (!strcmp(name, "prev"))
5235 		sid = __tsec->osid;
5236 	else if (!strcmp(name, "exec"))
5237 		sid = __tsec->exec_sid;
5238 	else if (!strcmp(name, "fscreate"))
5239 		sid = __tsec->create_sid;
5240 	else if (!strcmp(name, "keycreate"))
5241 		sid = __tsec->keycreate_sid;
5242 	else if (!strcmp(name, "sockcreate"))
5243 		sid = __tsec->sockcreate_sid;
5244 	else
5245 		goto invalid;
5246 	rcu_read_unlock();
5247 
5248 	if (!sid)
5249 		return 0;
5250 
5251 	error = security_sid_to_context(sid, value, &len);
5252 	if (error)
5253 		return error;
5254 	return len;
5255 
5256 invalid:
5257 	rcu_read_unlock();
5258 	return -EINVAL;
5259 }
5260 
5261 static int selinux_setprocattr(struct task_struct *p,
5262 			       char *name, void *value, size_t size)
5263 {
5264 	struct task_security_struct *tsec;
5265 	struct task_struct *tracer;
5266 	struct cred *new;
5267 	u32 sid = 0, ptsid;
5268 	int error;
5269 	char *str = value;
5270 
5271 	if (current != p) {
5272 		/* SELinux only allows a process to change its own
5273 		   security attributes. */
5274 		return -EACCES;
5275 	}
5276 
5277 	/*
5278 	 * Basic control over ability to set these attributes at all.
5279 	 * current == p, but we'll pass them separately in case the
5280 	 * above restriction is ever removed.
5281 	 */
5282 	if (!strcmp(name, "exec"))
5283 		error = current_has_perm(p, PROCESS__SETEXEC);
5284 	else if (!strcmp(name, "fscreate"))
5285 		error = current_has_perm(p, PROCESS__SETFSCREATE);
5286 	else if (!strcmp(name, "keycreate"))
5287 		error = current_has_perm(p, PROCESS__SETKEYCREATE);
5288 	else if (!strcmp(name, "sockcreate"))
5289 		error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5290 	else if (!strcmp(name, "current"))
5291 		error = current_has_perm(p, PROCESS__SETCURRENT);
5292 	else
5293 		error = -EINVAL;
5294 	if (error)
5295 		return error;
5296 
5297 	/* Obtain a SID for the context, if one was specified. */
5298 	if (size && str[1] && str[1] != '\n') {
5299 		if (str[size-1] == '\n') {
5300 			str[size-1] = 0;
5301 			size--;
5302 		}
5303 		error = security_context_to_sid(value, size, &sid);
5304 		if (error == -EINVAL && !strcmp(name, "fscreate")) {
5305 			if (!capable(CAP_MAC_ADMIN)) {
5306 				struct audit_buffer *ab;
5307 				size_t audit_size;
5308 
5309 				/* We strip a nul only if it is at the end, otherwise the
5310 				 * context contains a nul and we should audit that */
5311 				if (str[size - 1] == '\0')
5312 					audit_size = size - 1;
5313 				else
5314 					audit_size = size;
5315 				ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
5316 				audit_log_format(ab, "op=fscreate invalid_context=");
5317 				audit_log_n_untrustedstring(ab, value, audit_size);
5318 				audit_log_end(ab);
5319 
5320 				return error;
5321 			}
5322 			error = security_context_to_sid_force(value, size,
5323 							      &sid);
5324 		}
5325 		if (error)
5326 			return error;
5327 	}
5328 
5329 	new = prepare_creds();
5330 	if (!new)
5331 		return -ENOMEM;
5332 
5333 	/* Permission checking based on the specified context is
5334 	   performed during the actual operation (execve,
5335 	   open/mkdir/...), when we know the full context of the
5336 	   operation.  See selinux_bprm_set_creds for the execve
5337 	   checks and may_create for the file creation checks. The
5338 	   operation will then fail if the context is not permitted. */
5339 	tsec = new->security;
5340 	if (!strcmp(name, "exec")) {
5341 		tsec->exec_sid = sid;
5342 	} else if (!strcmp(name, "fscreate")) {
5343 		tsec->create_sid = sid;
5344 	} else if (!strcmp(name, "keycreate")) {
5345 		error = may_create_key(sid, p);
5346 		if (error)
5347 			goto abort_change;
5348 		tsec->keycreate_sid = sid;
5349 	} else if (!strcmp(name, "sockcreate")) {
5350 		tsec->sockcreate_sid = sid;
5351 	} else if (!strcmp(name, "current")) {
5352 		error = -EINVAL;
5353 		if (sid == 0)
5354 			goto abort_change;
5355 
5356 		/* Only allow single threaded processes to change context */
5357 		error = -EPERM;
5358 		if (!current_is_single_threaded()) {
5359 			error = security_bounded_transition(tsec->sid, sid);
5360 			if (error)
5361 				goto abort_change;
5362 		}
5363 
5364 		/* Check permissions for the transition. */
5365 		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5366 				     PROCESS__DYNTRANSITION, NULL);
5367 		if (error)
5368 			goto abort_change;
5369 
5370 		/* Check for ptracing, and update the task SID if ok.
5371 		   Otherwise, leave SID unchanged and fail. */
5372 		ptsid = 0;
5373 		task_lock(p);
5374 		tracer = ptrace_parent(p);
5375 		if (tracer)
5376 			ptsid = task_sid(tracer);
5377 		task_unlock(p);
5378 
5379 		if (tracer) {
5380 			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5381 					     PROCESS__PTRACE, NULL);
5382 			if (error)
5383 				goto abort_change;
5384 		}
5385 
5386 		tsec->sid = sid;
5387 	} else {
5388 		error = -EINVAL;
5389 		goto abort_change;
5390 	}
5391 
5392 	commit_creds(new);
5393 	return size;
5394 
5395 abort_change:
5396 	abort_creds(new);
5397 	return error;
5398 }
5399 
5400 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5401 {
5402 	return security_sid_to_context(secid, secdata, seclen);
5403 }
5404 
5405 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5406 {
5407 	return security_context_to_sid(secdata, seclen, secid);
5408 }
5409 
5410 static void selinux_release_secctx(char *secdata, u32 seclen)
5411 {
5412 	kfree(secdata);
5413 }
5414 
5415 /*
5416  *	called with inode->i_mutex locked
5417  */
5418 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5419 {
5420 	return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5421 }
5422 
5423 /*
5424  *	called with inode->i_mutex locked
5425  */
5426 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
5427 {
5428 	return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
5429 }
5430 
5431 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
5432 {
5433 	int len = 0;
5434 	len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
5435 						ctx, true);
5436 	if (len < 0)
5437 		return len;
5438 	*ctxlen = len;
5439 	return 0;
5440 }
5441 #ifdef CONFIG_KEYS
5442 
5443 static int selinux_key_alloc(struct key *k, const struct cred *cred,
5444 			     unsigned long flags)
5445 {
5446 	const struct task_security_struct *tsec;
5447 	struct key_security_struct *ksec;
5448 
5449 	ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
5450 	if (!ksec)
5451 		return -ENOMEM;
5452 
5453 	tsec = cred->security;
5454 	if (tsec->keycreate_sid)
5455 		ksec->sid = tsec->keycreate_sid;
5456 	else
5457 		ksec->sid = tsec->sid;
5458 
5459 	k->security = ksec;
5460 	return 0;
5461 }
5462 
5463 static void selinux_key_free(struct key *k)
5464 {
5465 	struct key_security_struct *ksec = k->security;
5466 
5467 	k->security = NULL;
5468 	kfree(ksec);
5469 }
5470 
5471 static int selinux_key_permission(key_ref_t key_ref,
5472 				  const struct cred *cred,
5473 				  key_perm_t perm)
5474 {
5475 	struct key *key;
5476 	struct key_security_struct *ksec;
5477 	u32 sid;
5478 
5479 	/* if no specific permissions are requested, we skip the
5480 	   permission check. No serious, additional covert channels
5481 	   appear to be created. */
5482 	if (perm == 0)
5483 		return 0;
5484 
5485 	sid = cred_sid(cred);
5486 
5487 	key = key_ref_to_ptr(key_ref);
5488 	ksec = key->security;
5489 
5490 	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5491 }
5492 
5493 static int selinux_key_getsecurity(struct key *key, char **_buffer)
5494 {
5495 	struct key_security_struct *ksec = key->security;
5496 	char *context = NULL;
5497 	unsigned len;
5498 	int rc;
5499 
5500 	rc = security_sid_to_context(ksec->sid, &context, &len);
5501 	if (!rc)
5502 		rc = len;
5503 	*_buffer = context;
5504 	return rc;
5505 }
5506 
5507 #endif
5508 
5509 static struct security_operations selinux_ops = {
5510 	.name =				"selinux",
5511 
5512 	.ptrace_access_check =		selinux_ptrace_access_check,
5513 	.ptrace_traceme =		selinux_ptrace_traceme,
5514 	.capget =			selinux_capget,
5515 	.capset =			selinux_capset,
5516 	.capable =			selinux_capable,
5517 	.quotactl =			selinux_quotactl,
5518 	.quota_on =			selinux_quota_on,
5519 	.syslog =			selinux_syslog,
5520 	.vm_enough_memory =		selinux_vm_enough_memory,
5521 
5522 	.netlink_send =			selinux_netlink_send,
5523 
5524 	.bprm_set_creds =		selinux_bprm_set_creds,
5525 	.bprm_committing_creds =	selinux_bprm_committing_creds,
5526 	.bprm_committed_creds =		selinux_bprm_committed_creds,
5527 	.bprm_secureexec =		selinux_bprm_secureexec,
5528 
5529 	.sb_alloc_security =		selinux_sb_alloc_security,
5530 	.sb_free_security =		selinux_sb_free_security,
5531 	.sb_copy_data =			selinux_sb_copy_data,
5532 	.sb_remount =			selinux_sb_remount,
5533 	.sb_kern_mount =		selinux_sb_kern_mount,
5534 	.sb_show_options =		selinux_sb_show_options,
5535 	.sb_statfs =			selinux_sb_statfs,
5536 	.sb_mount =			selinux_mount,
5537 	.sb_umount =			selinux_umount,
5538 	.sb_set_mnt_opts =		selinux_set_mnt_opts,
5539 	.sb_clone_mnt_opts =		selinux_sb_clone_mnt_opts,
5540 	.sb_parse_opts_str = 		selinux_parse_opts_str,
5541 
5542 
5543 	.inode_alloc_security =		selinux_inode_alloc_security,
5544 	.inode_free_security =		selinux_inode_free_security,
5545 	.inode_init_security =		selinux_inode_init_security,
5546 	.inode_create =			selinux_inode_create,
5547 	.inode_link =			selinux_inode_link,
5548 	.inode_unlink =			selinux_inode_unlink,
5549 	.inode_symlink =		selinux_inode_symlink,
5550 	.inode_mkdir =			selinux_inode_mkdir,
5551 	.inode_rmdir =			selinux_inode_rmdir,
5552 	.inode_mknod =			selinux_inode_mknod,
5553 	.inode_rename =			selinux_inode_rename,
5554 	.inode_readlink =		selinux_inode_readlink,
5555 	.inode_follow_link =		selinux_inode_follow_link,
5556 	.inode_permission =		selinux_inode_permission,
5557 	.inode_setattr =		selinux_inode_setattr,
5558 	.inode_getattr =		selinux_inode_getattr,
5559 	.inode_setxattr =		selinux_inode_setxattr,
5560 	.inode_post_setxattr =		selinux_inode_post_setxattr,
5561 	.inode_getxattr =		selinux_inode_getxattr,
5562 	.inode_listxattr =		selinux_inode_listxattr,
5563 	.inode_removexattr =		selinux_inode_removexattr,
5564 	.inode_getsecurity =		selinux_inode_getsecurity,
5565 	.inode_setsecurity =		selinux_inode_setsecurity,
5566 	.inode_listsecurity =		selinux_inode_listsecurity,
5567 	.inode_getsecid =		selinux_inode_getsecid,
5568 
5569 	.file_permission =		selinux_file_permission,
5570 	.file_alloc_security =		selinux_file_alloc_security,
5571 	.file_free_security =		selinux_file_free_security,
5572 	.file_ioctl =			selinux_file_ioctl,
5573 	.mmap_file =			selinux_mmap_file,
5574 	.mmap_addr =			selinux_mmap_addr,
5575 	.file_mprotect =		selinux_file_mprotect,
5576 	.file_lock =			selinux_file_lock,
5577 	.file_fcntl =			selinux_file_fcntl,
5578 	.file_set_fowner =		selinux_file_set_fowner,
5579 	.file_send_sigiotask =		selinux_file_send_sigiotask,
5580 	.file_receive =			selinux_file_receive,
5581 
5582 	.file_open =			selinux_file_open,
5583 
5584 	.task_create =			selinux_task_create,
5585 	.cred_alloc_blank =		selinux_cred_alloc_blank,
5586 	.cred_free =			selinux_cred_free,
5587 	.cred_prepare =			selinux_cred_prepare,
5588 	.cred_transfer =		selinux_cred_transfer,
5589 	.kernel_act_as =		selinux_kernel_act_as,
5590 	.kernel_create_files_as =	selinux_kernel_create_files_as,
5591 	.kernel_module_request =	selinux_kernel_module_request,
5592 	.task_setpgid =			selinux_task_setpgid,
5593 	.task_getpgid =			selinux_task_getpgid,
5594 	.task_getsid =			selinux_task_getsid,
5595 	.task_getsecid =		selinux_task_getsecid,
5596 	.task_setnice =			selinux_task_setnice,
5597 	.task_setioprio =		selinux_task_setioprio,
5598 	.task_getioprio =		selinux_task_getioprio,
5599 	.task_setrlimit =		selinux_task_setrlimit,
5600 	.task_setscheduler =		selinux_task_setscheduler,
5601 	.task_getscheduler =		selinux_task_getscheduler,
5602 	.task_movememory =		selinux_task_movememory,
5603 	.task_kill =			selinux_task_kill,
5604 	.task_wait =			selinux_task_wait,
5605 	.task_to_inode =		selinux_task_to_inode,
5606 
5607 	.ipc_permission =		selinux_ipc_permission,
5608 	.ipc_getsecid =			selinux_ipc_getsecid,
5609 
5610 	.msg_msg_alloc_security =	selinux_msg_msg_alloc_security,
5611 	.msg_msg_free_security =	selinux_msg_msg_free_security,
5612 
5613 	.msg_queue_alloc_security =	selinux_msg_queue_alloc_security,
5614 	.msg_queue_free_security =	selinux_msg_queue_free_security,
5615 	.msg_queue_associate =		selinux_msg_queue_associate,
5616 	.msg_queue_msgctl =		selinux_msg_queue_msgctl,
5617 	.msg_queue_msgsnd =		selinux_msg_queue_msgsnd,
5618 	.msg_queue_msgrcv =		selinux_msg_queue_msgrcv,
5619 
5620 	.shm_alloc_security =		selinux_shm_alloc_security,
5621 	.shm_free_security =		selinux_shm_free_security,
5622 	.shm_associate =		selinux_shm_associate,
5623 	.shm_shmctl =			selinux_shm_shmctl,
5624 	.shm_shmat =			selinux_shm_shmat,
5625 
5626 	.sem_alloc_security =		selinux_sem_alloc_security,
5627 	.sem_free_security =		selinux_sem_free_security,
5628 	.sem_associate =		selinux_sem_associate,
5629 	.sem_semctl =			selinux_sem_semctl,
5630 	.sem_semop =			selinux_sem_semop,
5631 
5632 	.d_instantiate =		selinux_d_instantiate,
5633 
5634 	.getprocattr =			selinux_getprocattr,
5635 	.setprocattr =			selinux_setprocattr,
5636 
5637 	.secid_to_secctx =		selinux_secid_to_secctx,
5638 	.secctx_to_secid =		selinux_secctx_to_secid,
5639 	.release_secctx =		selinux_release_secctx,
5640 	.inode_notifysecctx =		selinux_inode_notifysecctx,
5641 	.inode_setsecctx =		selinux_inode_setsecctx,
5642 	.inode_getsecctx =		selinux_inode_getsecctx,
5643 
5644 	.unix_stream_connect =		selinux_socket_unix_stream_connect,
5645 	.unix_may_send =		selinux_socket_unix_may_send,
5646 
5647 	.socket_create =		selinux_socket_create,
5648 	.socket_post_create =		selinux_socket_post_create,
5649 	.socket_bind =			selinux_socket_bind,
5650 	.socket_connect =		selinux_socket_connect,
5651 	.socket_listen =		selinux_socket_listen,
5652 	.socket_accept =		selinux_socket_accept,
5653 	.socket_sendmsg =		selinux_socket_sendmsg,
5654 	.socket_recvmsg =		selinux_socket_recvmsg,
5655 	.socket_getsockname =		selinux_socket_getsockname,
5656 	.socket_getpeername =		selinux_socket_getpeername,
5657 	.socket_getsockopt =		selinux_socket_getsockopt,
5658 	.socket_setsockopt =		selinux_socket_setsockopt,
5659 	.socket_shutdown =		selinux_socket_shutdown,
5660 	.socket_sock_rcv_skb =		selinux_socket_sock_rcv_skb,
5661 	.socket_getpeersec_stream =	selinux_socket_getpeersec_stream,
5662 	.socket_getpeersec_dgram =	selinux_socket_getpeersec_dgram,
5663 	.sk_alloc_security =		selinux_sk_alloc_security,
5664 	.sk_free_security =		selinux_sk_free_security,
5665 	.sk_clone_security =		selinux_sk_clone_security,
5666 	.sk_getsecid =			selinux_sk_getsecid,
5667 	.sock_graft =			selinux_sock_graft,
5668 	.inet_conn_request =		selinux_inet_conn_request,
5669 	.inet_csk_clone =		selinux_inet_csk_clone,
5670 	.inet_conn_established =	selinux_inet_conn_established,
5671 	.secmark_relabel_packet =	selinux_secmark_relabel_packet,
5672 	.secmark_refcount_inc =		selinux_secmark_refcount_inc,
5673 	.secmark_refcount_dec =		selinux_secmark_refcount_dec,
5674 	.req_classify_flow =		selinux_req_classify_flow,
5675 	.tun_dev_create =		selinux_tun_dev_create,
5676 	.tun_dev_post_create = 		selinux_tun_dev_post_create,
5677 	.tun_dev_attach =		selinux_tun_dev_attach,
5678 
5679 #ifdef CONFIG_SECURITY_NETWORK_XFRM
5680 	.xfrm_policy_alloc_security =	selinux_xfrm_policy_alloc,
5681 	.xfrm_policy_clone_security =	selinux_xfrm_policy_clone,
5682 	.xfrm_policy_free_security =	selinux_xfrm_policy_free,
5683 	.xfrm_policy_delete_security =	selinux_xfrm_policy_delete,
5684 	.xfrm_state_alloc_security =	selinux_xfrm_state_alloc,
5685 	.xfrm_state_free_security =	selinux_xfrm_state_free,
5686 	.xfrm_state_delete_security =	selinux_xfrm_state_delete,
5687 	.xfrm_policy_lookup =		selinux_xfrm_policy_lookup,
5688 	.xfrm_state_pol_flow_match =	selinux_xfrm_state_pol_flow_match,
5689 	.xfrm_decode_session =		selinux_xfrm_decode_session,
5690 #endif
5691 
5692 #ifdef CONFIG_KEYS
5693 	.key_alloc =			selinux_key_alloc,
5694 	.key_free =			selinux_key_free,
5695 	.key_permission =		selinux_key_permission,
5696 	.key_getsecurity =		selinux_key_getsecurity,
5697 #endif
5698 
5699 #ifdef CONFIG_AUDIT
5700 	.audit_rule_init =		selinux_audit_rule_init,
5701 	.audit_rule_known =		selinux_audit_rule_known,
5702 	.audit_rule_match =		selinux_audit_rule_match,
5703 	.audit_rule_free =		selinux_audit_rule_free,
5704 #endif
5705 };
5706 
5707 static __init int selinux_init(void)
5708 {
5709 	if (!security_module_enable(&selinux_ops)) {
5710 		selinux_enabled = 0;
5711 		return 0;
5712 	}
5713 
5714 	if (!selinux_enabled) {
5715 		printk(KERN_INFO "SELinux:  Disabled at boot.\n");
5716 		return 0;
5717 	}
5718 
5719 	printk(KERN_INFO "SELinux:  Initializing.\n");
5720 
5721 	/* Set the security state for the initial task. */
5722 	cred_init_security();
5723 
5724 	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
5725 
5726 	sel_inode_cache = kmem_cache_create("selinux_inode_security",
5727 					    sizeof(struct inode_security_struct),
5728 					    0, SLAB_PANIC, NULL);
5729 	avc_init();
5730 
5731 	if (register_security(&selinux_ops))
5732 		panic("SELinux: Unable to register with kernel.\n");
5733 
5734 	if (selinux_enforcing)
5735 		printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
5736 	else
5737 		printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
5738 
5739 	return 0;
5740 }
5741 
5742 static void delayed_superblock_init(struct super_block *sb, void *unused)
5743 {
5744 	superblock_doinit(sb, NULL);
5745 }
5746 
5747 void selinux_complete_init(void)
5748 {
5749 	printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
5750 
5751 	/* Set up any superblocks initialized prior to the policy load. */
5752 	printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
5753 	iterate_supers(delayed_superblock_init, NULL);
5754 }
5755 
5756 /* SELinux requires early initialization in order to label
5757    all processes and objects when they are created. */
5758 security_initcall(selinux_init);
5759 
5760 #if defined(CONFIG_NETFILTER)
5761 
5762 static struct nf_hook_ops selinux_ipv4_ops[] = {
5763 	{
5764 		.hook =		selinux_ipv4_postroute,
5765 		.owner =	THIS_MODULE,
5766 		.pf =		PF_INET,
5767 		.hooknum =	NF_INET_POST_ROUTING,
5768 		.priority =	NF_IP_PRI_SELINUX_LAST,
5769 	},
5770 	{
5771 		.hook =		selinux_ipv4_forward,
5772 		.owner =	THIS_MODULE,
5773 		.pf =		PF_INET,
5774 		.hooknum =	NF_INET_FORWARD,
5775 		.priority =	NF_IP_PRI_SELINUX_FIRST,
5776 	},
5777 	{
5778 		.hook =		selinux_ipv4_output,
5779 		.owner =	THIS_MODULE,
5780 		.pf =		PF_INET,
5781 		.hooknum =	NF_INET_LOCAL_OUT,
5782 		.priority =	NF_IP_PRI_SELINUX_FIRST,
5783 	}
5784 };
5785 
5786 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5787 
5788 static struct nf_hook_ops selinux_ipv6_ops[] = {
5789 	{
5790 		.hook =		selinux_ipv6_postroute,
5791 		.owner =	THIS_MODULE,
5792 		.pf =		PF_INET6,
5793 		.hooknum =	NF_INET_POST_ROUTING,
5794 		.priority =	NF_IP6_PRI_SELINUX_LAST,
5795 	},
5796 	{
5797 		.hook =		selinux_ipv6_forward,
5798 		.owner =	THIS_MODULE,
5799 		.pf =		PF_INET6,
5800 		.hooknum =	NF_INET_FORWARD,
5801 		.priority =	NF_IP6_PRI_SELINUX_FIRST,
5802 	}
5803 };
5804 
5805 #endif	/* IPV6 */
5806 
5807 static int __init selinux_nf_ip_init(void)
5808 {
5809 	int err = 0;
5810 
5811 	if (!selinux_enabled)
5812 		goto out;
5813 
5814 	printk(KERN_DEBUG "SELinux:  Registering netfilter hooks\n");
5815 
5816 	err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5817 	if (err)
5818 		panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
5819 
5820 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5821 	err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5822 	if (err)
5823 		panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
5824 #endif	/* IPV6 */
5825 
5826 out:
5827 	return err;
5828 }
5829 
5830 __initcall(selinux_nf_ip_init);
5831 
5832 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5833 static void selinux_nf_ip_exit(void)
5834 {
5835 	printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
5836 
5837 	nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5838 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5839 	nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5840 #endif	/* IPV6 */
5841 }
5842 #endif
5843 
5844 #else /* CONFIG_NETFILTER */
5845 
5846 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5847 #define selinux_nf_ip_exit()
5848 #endif
5849 
5850 #endif /* CONFIG_NETFILTER */
5851 
5852 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5853 static int selinux_disabled;
5854 
5855 int selinux_disable(void)
5856 {
5857 	if (ss_initialized) {
5858 		/* Not permitted after initial policy load. */
5859 		return -EINVAL;
5860 	}
5861 
5862 	if (selinux_disabled) {
5863 		/* Only do this once. */
5864 		return -EINVAL;
5865 	}
5866 
5867 	printk(KERN_INFO "SELinux:  Disabled at runtime.\n");
5868 
5869 	selinux_disabled = 1;
5870 	selinux_enabled = 0;
5871 
5872 	reset_security_ops();
5873 
5874 	/* Try to destroy the avc node cache */
5875 	avc_disable();
5876 
5877 	/* Unregister netfilter hooks. */
5878 	selinux_nf_ip_exit();
5879 
5880 	/* Unregister selinuxfs. */
5881 	exit_sel_fs();
5882 
5883 	return 0;
5884 }
5885 #endif
5886