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SELinux: implement the new sb_remount LSM hook
[deliverable/linux.git] / security / selinux / hooks.c
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.moore@hp.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/ext2_fs.h>
32 #include <linux/sched.h>
33 #include <linux/security.h>
34 #include <linux/xattr.h>
35 #include <linux/capability.h>
36 #include <linux/unistd.h>
37 #include <linux/mm.h>
38 #include <linux/mman.h>
39 #include <linux/slab.h>
40 #include <linux/pagemap.h>
41 #include <linux/proc_fs.h>
42 #include <linux/swap.h>
43 #include <linux/spinlock.h>
44 #include <linux/syscalls.h>
45 #include <linux/dcache.h>
46 #include <linux/file.h>
47 #include <linux/fdtable.h>
48 #include <linux/namei.h>
49 #include <linux/mount.h>
50 #include <linux/netfilter_ipv4.h>
51 #include <linux/netfilter_ipv6.h>
52 #include <linux/tty.h>
53 #include <net/icmp.h>
54 #include <net/ip.h> /* for local_port_range[] */
55 #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
56 #include <net/net_namespace.h>
57 #include <net/netlabel.h>
58 #include <linux/uaccess.h>
59 #include <asm/ioctls.h>
60 #include <asm/atomic.h>
61 #include <linux/bitops.h>
62 #include <linux/interrupt.h>
63 #include <linux/netdevice.h> /* for network interface checks */
64 #include <linux/netlink.h>
65 #include <linux/tcp.h>
66 #include <linux/udp.h>
67 #include <linux/dccp.h>
68 #include <linux/quota.h>
69 #include <linux/un.h> /* for Unix socket types */
70 #include <net/af_unix.h> /* for Unix socket types */
71 #include <linux/parser.h>
72 #include <linux/nfs_mount.h>
73 #include <net/ipv6.h>
74 #include <linux/hugetlb.h>
75 #include <linux/personality.h>
76 #include <linux/audit.h>
77 #include <linux/string.h>
78 #include <linux/selinux.h>
79 #include <linux/mutex.h>
80 #include <linux/posix-timers.h>
81 #include <linux/syslog.h>
82
83 #include "avc.h"
84 #include "objsec.h"
85 #include "netif.h"
86 #include "netnode.h"
87 #include "netport.h"
88 #include "xfrm.h"
89 #include "netlabel.h"
90 #include "audit.h"
91
92 #define NUM_SEL_MNT_OPTS 5
93
94 extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
95 extern struct security_operations *security_ops;
96
97 /* SECMARK reference count */
98 atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
99
100 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
101 int selinux_enforcing;
102
103 static int __init enforcing_setup(char *str)
104 {
105 unsigned long enforcing;
106 if (!strict_strtoul(str, 0, &enforcing))
107 selinux_enforcing = enforcing ? 1 : 0;
108 return 1;
109 }
110 __setup("enforcing=", enforcing_setup);
111 #endif
112
113 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
114 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
115
116 static int __init selinux_enabled_setup(char *str)
117 {
118 unsigned long enabled;
119 if (!strict_strtoul(str, 0, &enabled))
120 selinux_enabled = enabled ? 1 : 0;
121 return 1;
122 }
123 __setup("selinux=", selinux_enabled_setup);
124 #else
125 int selinux_enabled = 1;
126 #endif
127
128 static struct kmem_cache *sel_inode_cache;
129
130 /**
131 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
132 *
133 * Description:
134 * This function checks the SECMARK reference counter to see if any SECMARK
135 * targets are currently configured, if the reference counter is greater than
136 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is
137 * enabled, false (0) if SECMARK is disabled.
138 *
139 */
140 static int selinux_secmark_enabled(void)
141 {
142 return (atomic_read(&selinux_secmark_refcount) > 0);
143 }
144
145 /*
146 * initialise the security for the init task
147 */
148 static void cred_init_security(void)
149 {
150 struct cred *cred = (struct cred *) current->real_cred;
151 struct task_security_struct *tsec;
152
153 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
154 if (!tsec)
155 panic("SELinux: Failed to initialize initial task.\n");
156
157 tsec->osid = tsec->sid = SECINITSID_KERNEL;
158 cred->security = tsec;
159 }
160
161 /*
162 * get the security ID of a set of credentials
163 */
164 static inline u32 cred_sid(const struct cred *cred)
165 {
166 const struct task_security_struct *tsec;
167
168 tsec = cred->security;
169 return tsec->sid;
170 }
171
172 /*
173 * get the objective security ID of a task
174 */
175 static inline u32 task_sid(const struct task_struct *task)
176 {
177 u32 sid;
178
179 rcu_read_lock();
180 sid = cred_sid(__task_cred(task));
181 rcu_read_unlock();
182 return sid;
183 }
184
185 /*
186 * get the subjective security ID of the current task
187 */
188 static inline u32 current_sid(void)
189 {
190 const struct task_security_struct *tsec = current_security();
191
192 return tsec->sid;
193 }
194
195 /* Allocate and free functions for each kind of security blob. */
196
197 static int inode_alloc_security(struct inode *inode)
198 {
199 struct inode_security_struct *isec;
200 u32 sid = current_sid();
201
202 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
203 if (!isec)
204 return -ENOMEM;
205
206 mutex_init(&isec->lock);
207 INIT_LIST_HEAD(&isec->list);
208 isec->inode = inode;
209 isec->sid = SECINITSID_UNLABELED;
210 isec->sclass = SECCLASS_FILE;
211 isec->task_sid = sid;
212 inode->i_security = isec;
213
214 return 0;
215 }
216
217 static void inode_free_security(struct inode *inode)
218 {
219 struct inode_security_struct *isec = inode->i_security;
220 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
221
222 spin_lock(&sbsec->isec_lock);
223 if (!list_empty(&isec->list))
224 list_del_init(&isec->list);
225 spin_unlock(&sbsec->isec_lock);
226
227 inode->i_security = NULL;
228 kmem_cache_free(sel_inode_cache, isec);
229 }
230
231 static int file_alloc_security(struct file *file)
232 {
233 struct file_security_struct *fsec;
234 u32 sid = current_sid();
235
236 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
237 if (!fsec)
238 return -ENOMEM;
239
240 fsec->sid = sid;
241 fsec->fown_sid = sid;
242 file->f_security = fsec;
243
244 return 0;
245 }
246
247 static void file_free_security(struct file *file)
248 {
249 struct file_security_struct *fsec = file->f_security;
250 file->f_security = NULL;
251 kfree(fsec);
252 }
253
254 static int superblock_alloc_security(struct super_block *sb)
255 {
256 struct superblock_security_struct *sbsec;
257
258 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
259 if (!sbsec)
260 return -ENOMEM;
261
262 mutex_init(&sbsec->lock);
263 INIT_LIST_HEAD(&sbsec->isec_head);
264 spin_lock_init(&sbsec->isec_lock);
265 sbsec->sb = sb;
266 sbsec->sid = SECINITSID_UNLABELED;
267 sbsec->def_sid = SECINITSID_FILE;
268 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
269 sb->s_security = sbsec;
270
271 return 0;
272 }
273
274 static void superblock_free_security(struct super_block *sb)
275 {
276 struct superblock_security_struct *sbsec = sb->s_security;
277 sb->s_security = NULL;
278 kfree(sbsec);
279 }
280
281 /* The security server must be initialized before
282 any labeling or access decisions can be provided. */
283 extern int ss_initialized;
284
285 /* The file system's label must be initialized prior to use. */
286
287 static const char *labeling_behaviors[6] = {
288 "uses xattr",
289 "uses transition SIDs",
290 "uses task SIDs",
291 "uses genfs_contexts",
292 "not configured for labeling",
293 "uses mountpoint labeling",
294 };
295
296 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
297
298 static inline int inode_doinit(struct inode *inode)
299 {
300 return inode_doinit_with_dentry(inode, NULL);
301 }
302
303 enum {
304 Opt_error = -1,
305 Opt_context = 1,
306 Opt_fscontext = 2,
307 Opt_defcontext = 3,
308 Opt_rootcontext = 4,
309 Opt_labelsupport = 5,
310 };
311
312 static const match_table_t tokens = {
313 {Opt_context, CONTEXT_STR "%s"},
314 {Opt_fscontext, FSCONTEXT_STR "%s"},
315 {Opt_defcontext, DEFCONTEXT_STR "%s"},
316 {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
317 {Opt_labelsupport, LABELSUPP_STR},
318 {Opt_error, NULL},
319 };
320
321 #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
322
323 static int may_context_mount_sb_relabel(u32 sid,
324 struct superblock_security_struct *sbsec,
325 const struct cred *cred)
326 {
327 const struct task_security_struct *tsec = cred->security;
328 int rc;
329
330 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
331 FILESYSTEM__RELABELFROM, NULL);
332 if (rc)
333 return rc;
334
335 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
336 FILESYSTEM__RELABELTO, NULL);
337 return rc;
338 }
339
340 static int may_context_mount_inode_relabel(u32 sid,
341 struct superblock_security_struct *sbsec,
342 const struct cred *cred)
343 {
344 const struct task_security_struct *tsec = cred->security;
345 int rc;
346 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
347 FILESYSTEM__RELABELFROM, NULL);
348 if (rc)
349 return rc;
350
351 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
352 FILESYSTEM__ASSOCIATE, NULL);
353 return rc;
354 }
355
356 static int sb_finish_set_opts(struct super_block *sb)
357 {
358 struct superblock_security_struct *sbsec = sb->s_security;
359 struct dentry *root = sb->s_root;
360 struct inode *root_inode = root->d_inode;
361 int rc = 0;
362
363 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
364 /* Make sure that the xattr handler exists and that no
365 error other than -ENODATA is returned by getxattr on
366 the root directory. -ENODATA is ok, as this may be
367 the first boot of the SELinux kernel before we have
368 assigned xattr values to the filesystem. */
369 if (!root_inode->i_op->getxattr) {
370 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
371 "xattr support\n", sb->s_id, sb->s_type->name);
372 rc = -EOPNOTSUPP;
373 goto out;
374 }
375 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
376 if (rc < 0 && rc != -ENODATA) {
377 if (rc == -EOPNOTSUPP)
378 printk(KERN_WARNING "SELinux: (dev %s, type "
379 "%s) has no security xattr handler\n",
380 sb->s_id, sb->s_type->name);
381 else
382 printk(KERN_WARNING "SELinux: (dev %s, type "
383 "%s) getxattr errno %d\n", sb->s_id,
384 sb->s_type->name, -rc);
385 goto out;
386 }
387 }
388
389 sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
390
391 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
392 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
393 sb->s_id, sb->s_type->name);
394 else
395 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
396 sb->s_id, sb->s_type->name,
397 labeling_behaviors[sbsec->behavior-1]);
398
399 if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
400 sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
401 sbsec->behavior == SECURITY_FS_USE_NONE ||
402 sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
403 sbsec->flags &= ~SE_SBLABELSUPP;
404
405 /* Special handling for sysfs. Is genfs but also has setxattr handler*/
406 if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
407 sbsec->flags |= SE_SBLABELSUPP;
408
409 /* Initialize the root inode. */
410 rc = inode_doinit_with_dentry(root_inode, root);
411
412 /* Initialize any other inodes associated with the superblock, e.g.
413 inodes created prior to initial policy load or inodes created
414 during get_sb by a pseudo filesystem that directly
415 populates itself. */
416 spin_lock(&sbsec->isec_lock);
417 next_inode:
418 if (!list_empty(&sbsec->isec_head)) {
419 struct inode_security_struct *isec =
420 list_entry(sbsec->isec_head.next,
421 struct inode_security_struct, list);
422 struct inode *inode = isec->inode;
423 spin_unlock(&sbsec->isec_lock);
424 inode = igrab(inode);
425 if (inode) {
426 if (!IS_PRIVATE(inode))
427 inode_doinit(inode);
428 iput(inode);
429 }
430 spin_lock(&sbsec->isec_lock);
431 list_del_init(&isec->list);
432 goto next_inode;
433 }
434 spin_unlock(&sbsec->isec_lock);
435 out:
436 return rc;
437 }
438
439 /*
440 * This function should allow an FS to ask what it's mount security
441 * options were so it can use those later for submounts, displaying
442 * mount options, or whatever.
443 */
444 static int selinux_get_mnt_opts(const struct super_block *sb,
445 struct security_mnt_opts *opts)
446 {
447 int rc = 0, i;
448 struct superblock_security_struct *sbsec = sb->s_security;
449 char *context = NULL;
450 u32 len;
451 char tmp;
452
453 security_init_mnt_opts(opts);
454
455 if (!(sbsec->flags & SE_SBINITIALIZED))
456 return -EINVAL;
457
458 if (!ss_initialized)
459 return -EINVAL;
460
461 tmp = sbsec->flags & SE_MNTMASK;
462 /* count the number of mount options for this sb */
463 for (i = 0; i < 8; i++) {
464 if (tmp & 0x01)
465 opts->num_mnt_opts++;
466 tmp >>= 1;
467 }
468 /* Check if the Label support flag is set */
469 if (sbsec->flags & SE_SBLABELSUPP)
470 opts->num_mnt_opts++;
471
472 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
473 if (!opts->mnt_opts) {
474 rc = -ENOMEM;
475 goto out_free;
476 }
477
478 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
479 if (!opts->mnt_opts_flags) {
480 rc = -ENOMEM;
481 goto out_free;
482 }
483
484 i = 0;
485 if (sbsec->flags & FSCONTEXT_MNT) {
486 rc = security_sid_to_context(sbsec->sid, &context, &len);
487 if (rc)
488 goto out_free;
489 opts->mnt_opts[i] = context;
490 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
491 }
492 if (sbsec->flags & CONTEXT_MNT) {
493 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
494 if (rc)
495 goto out_free;
496 opts->mnt_opts[i] = context;
497 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
498 }
499 if (sbsec->flags & DEFCONTEXT_MNT) {
500 rc = security_sid_to_context(sbsec->def_sid, &context, &len);
501 if (rc)
502 goto out_free;
503 opts->mnt_opts[i] = context;
504 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
505 }
506 if (sbsec->flags & ROOTCONTEXT_MNT) {
507 struct inode *root = sbsec->sb->s_root->d_inode;
508 struct inode_security_struct *isec = root->i_security;
509
510 rc = security_sid_to_context(isec->sid, &context, &len);
511 if (rc)
512 goto out_free;
513 opts->mnt_opts[i] = context;
514 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
515 }
516 if (sbsec->flags & SE_SBLABELSUPP) {
517 opts->mnt_opts[i] = NULL;
518 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
519 }
520
521 BUG_ON(i != opts->num_mnt_opts);
522
523 return 0;
524
525 out_free:
526 security_free_mnt_opts(opts);
527 return rc;
528 }
529
530 static int bad_option(struct superblock_security_struct *sbsec, char flag,
531 u32 old_sid, u32 new_sid)
532 {
533 char mnt_flags = sbsec->flags & SE_MNTMASK;
534
535 /* check if the old mount command had the same options */
536 if (sbsec->flags & SE_SBINITIALIZED)
537 if (!(sbsec->flags & flag) ||
538 (old_sid != new_sid))
539 return 1;
540
541 /* check if we were passed the same options twice,
542 * aka someone passed context=a,context=b
543 */
544 if (!(sbsec->flags & SE_SBINITIALIZED))
545 if (mnt_flags & flag)
546 return 1;
547 return 0;
548 }
549
550 /*
551 * Allow filesystems with binary mount data to explicitly set mount point
552 * labeling information.
553 */
554 static int selinux_set_mnt_opts(struct super_block *sb,
555 struct security_mnt_opts *opts)
556 {
557 const struct cred *cred = current_cred();
558 int rc = 0, i;
559 struct superblock_security_struct *sbsec = sb->s_security;
560 const char *name = sb->s_type->name;
561 struct inode *inode = sbsec->sb->s_root->d_inode;
562 struct inode_security_struct *root_isec = inode->i_security;
563 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
564 u32 defcontext_sid = 0;
565 char **mount_options = opts->mnt_opts;
566 int *flags = opts->mnt_opts_flags;
567 int num_opts = opts->num_mnt_opts;
568
569 mutex_lock(&sbsec->lock);
570
571 if (!ss_initialized) {
572 if (!num_opts) {
573 /* Defer initialization until selinux_complete_init,
574 after the initial policy is loaded and the security
575 server is ready to handle calls. */
576 goto out;
577 }
578 rc = -EINVAL;
579 printk(KERN_WARNING "SELinux: Unable to set superblock options "
580 "before the security server is initialized\n");
581 goto out;
582 }
583
584 /*
585 * Binary mount data FS will come through this function twice. Once
586 * from an explicit call and once from the generic calls from the vfs.
587 * Since the generic VFS calls will not contain any security mount data
588 * we need to skip the double mount verification.
589 *
590 * This does open a hole in which we will not notice if the first
591 * mount using this sb set explict options and a second mount using
592 * this sb does not set any security options. (The first options
593 * will be used for both mounts)
594 */
595 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
596 && (num_opts == 0))
597 goto out;
598
599 /*
600 * parse the mount options, check if they are valid sids.
601 * also check if someone is trying to mount the same sb more
602 * than once with different security options.
603 */
604 for (i = 0; i < num_opts; i++) {
605 u32 sid;
606
607 if (flags[i] == SE_SBLABELSUPP)
608 continue;
609 rc = security_context_to_sid(mount_options[i],
610 strlen(mount_options[i]), &sid);
611 if (rc) {
612 printk(KERN_WARNING "SELinux: security_context_to_sid"
613 "(%s) failed for (dev %s, type %s) errno=%d\n",
614 mount_options[i], sb->s_id, name, rc);
615 goto out;
616 }
617 switch (flags[i]) {
618 case FSCONTEXT_MNT:
619 fscontext_sid = sid;
620
621 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
622 fscontext_sid))
623 goto out_double_mount;
624
625 sbsec->flags |= FSCONTEXT_MNT;
626 break;
627 case CONTEXT_MNT:
628 context_sid = sid;
629
630 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
631 context_sid))
632 goto out_double_mount;
633
634 sbsec->flags |= CONTEXT_MNT;
635 break;
636 case ROOTCONTEXT_MNT:
637 rootcontext_sid = sid;
638
639 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
640 rootcontext_sid))
641 goto out_double_mount;
642
643 sbsec->flags |= ROOTCONTEXT_MNT;
644
645 break;
646 case DEFCONTEXT_MNT:
647 defcontext_sid = sid;
648
649 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
650 defcontext_sid))
651 goto out_double_mount;
652
653 sbsec->flags |= DEFCONTEXT_MNT;
654
655 break;
656 default:
657 rc = -EINVAL;
658 goto out;
659 }
660 }
661
662 if (sbsec->flags & SE_SBINITIALIZED) {
663 /* previously mounted with options, but not on this attempt? */
664 if ((sbsec->flags & SE_MNTMASK) && !num_opts)
665 goto out_double_mount;
666 rc = 0;
667 goto out;
668 }
669
670 if (strcmp(sb->s_type->name, "proc") == 0)
671 sbsec->flags |= SE_SBPROC;
672
673 /* Determine the labeling behavior to use for this filesystem type. */
674 rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
675 if (rc) {
676 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
677 __func__, sb->s_type->name, rc);
678 goto out;
679 }
680
681 /* sets the context of the superblock for the fs being mounted. */
682 if (fscontext_sid) {
683 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
684 if (rc)
685 goto out;
686
687 sbsec->sid = fscontext_sid;
688 }
689
690 /*
691 * Switch to using mount point labeling behavior.
692 * sets the label used on all file below the mountpoint, and will set
693 * the superblock context if not already set.
694 */
695 if (context_sid) {
696 if (!fscontext_sid) {
697 rc = may_context_mount_sb_relabel(context_sid, sbsec,
698 cred);
699 if (rc)
700 goto out;
701 sbsec->sid = context_sid;
702 } else {
703 rc = may_context_mount_inode_relabel(context_sid, sbsec,
704 cred);
705 if (rc)
706 goto out;
707 }
708 if (!rootcontext_sid)
709 rootcontext_sid = context_sid;
710
711 sbsec->mntpoint_sid = context_sid;
712 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
713 }
714
715 if (rootcontext_sid) {
716 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
717 cred);
718 if (rc)
719 goto out;
720
721 root_isec->sid = rootcontext_sid;
722 root_isec->initialized = 1;
723 }
724
725 if (defcontext_sid) {
726 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
727 rc = -EINVAL;
728 printk(KERN_WARNING "SELinux: defcontext option is "
729 "invalid for this filesystem type\n");
730 goto out;
731 }
732
733 if (defcontext_sid != sbsec->def_sid) {
734 rc = may_context_mount_inode_relabel(defcontext_sid,
735 sbsec, cred);
736 if (rc)
737 goto out;
738 }
739
740 sbsec->def_sid = defcontext_sid;
741 }
742
743 rc = sb_finish_set_opts(sb);
744 out:
745 mutex_unlock(&sbsec->lock);
746 return rc;
747 out_double_mount:
748 rc = -EINVAL;
749 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different "
750 "security settings for (dev %s, type %s)\n", sb->s_id, name);
751 goto out;
752 }
753
754 static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
755 struct super_block *newsb)
756 {
757 const struct superblock_security_struct *oldsbsec = oldsb->s_security;
758 struct superblock_security_struct *newsbsec = newsb->s_security;
759
760 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
761 int set_context = (oldsbsec->flags & CONTEXT_MNT);
762 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
763
764 /*
765 * if the parent was able to be mounted it clearly had no special lsm
766 * mount options. thus we can safely deal with this superblock later
767 */
768 if (!ss_initialized)
769 return;
770
771 /* how can we clone if the old one wasn't set up?? */
772 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
773
774 /* if fs is reusing a sb, just let its options stand... */
775 if (newsbsec->flags & SE_SBINITIALIZED)
776 return;
777
778 mutex_lock(&newsbsec->lock);
779
780 newsbsec->flags = oldsbsec->flags;
781
782 newsbsec->sid = oldsbsec->sid;
783 newsbsec->def_sid = oldsbsec->def_sid;
784 newsbsec->behavior = oldsbsec->behavior;
785
786 if (set_context) {
787 u32 sid = oldsbsec->mntpoint_sid;
788
789 if (!set_fscontext)
790 newsbsec->sid = sid;
791 if (!set_rootcontext) {
792 struct inode *newinode = newsb->s_root->d_inode;
793 struct inode_security_struct *newisec = newinode->i_security;
794 newisec->sid = sid;
795 }
796 newsbsec->mntpoint_sid = sid;
797 }
798 if (set_rootcontext) {
799 const struct inode *oldinode = oldsb->s_root->d_inode;
800 const struct inode_security_struct *oldisec = oldinode->i_security;
801 struct inode *newinode = newsb->s_root->d_inode;
802 struct inode_security_struct *newisec = newinode->i_security;
803
804 newisec->sid = oldisec->sid;
805 }
806
807 sb_finish_set_opts(newsb);
808 mutex_unlock(&newsbsec->lock);
809 }
810
811 static int selinux_parse_opts_str(char *options,
812 struct security_mnt_opts *opts)
813 {
814 char *p;
815 char *context = NULL, *defcontext = NULL;
816 char *fscontext = NULL, *rootcontext = NULL;
817 int rc, num_mnt_opts = 0;
818
819 opts->num_mnt_opts = 0;
820
821 /* Standard string-based options. */
822 while ((p = strsep(&options, "|")) != NULL) {
823 int token;
824 substring_t args[MAX_OPT_ARGS];
825
826 if (!*p)
827 continue;
828
829 token = match_token(p, tokens, args);
830
831 switch (token) {
832 case Opt_context:
833 if (context || defcontext) {
834 rc = -EINVAL;
835 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
836 goto out_err;
837 }
838 context = match_strdup(&args[0]);
839 if (!context) {
840 rc = -ENOMEM;
841 goto out_err;
842 }
843 break;
844
845 case Opt_fscontext:
846 if (fscontext) {
847 rc = -EINVAL;
848 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
849 goto out_err;
850 }
851 fscontext = match_strdup(&args[0]);
852 if (!fscontext) {
853 rc = -ENOMEM;
854 goto out_err;
855 }
856 break;
857
858 case Opt_rootcontext:
859 if (rootcontext) {
860 rc = -EINVAL;
861 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
862 goto out_err;
863 }
864 rootcontext = match_strdup(&args[0]);
865 if (!rootcontext) {
866 rc = -ENOMEM;
867 goto out_err;
868 }
869 break;
870
871 case Opt_defcontext:
872 if (context || defcontext) {
873 rc = -EINVAL;
874 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
875 goto out_err;
876 }
877 defcontext = match_strdup(&args[0]);
878 if (!defcontext) {
879 rc = -ENOMEM;
880 goto out_err;
881 }
882 break;
883 case Opt_labelsupport:
884 break;
885 default:
886 rc = -EINVAL;
887 printk(KERN_WARNING "SELinux: unknown mount option\n");
888 goto out_err;
889
890 }
891 }
892
893 rc = -ENOMEM;
894 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
895 if (!opts->mnt_opts)
896 goto out_err;
897
898 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
899 if (!opts->mnt_opts_flags) {
900 kfree(opts->mnt_opts);
901 goto out_err;
902 }
903
904 if (fscontext) {
905 opts->mnt_opts[num_mnt_opts] = fscontext;
906 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
907 }
908 if (context) {
909 opts->mnt_opts[num_mnt_opts] = context;
910 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
911 }
912 if (rootcontext) {
913 opts->mnt_opts[num_mnt_opts] = rootcontext;
914 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
915 }
916 if (defcontext) {
917 opts->mnt_opts[num_mnt_opts] = defcontext;
918 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
919 }
920
921 opts->num_mnt_opts = num_mnt_opts;
922 return 0;
923
924 out_err:
925 kfree(context);
926 kfree(defcontext);
927 kfree(fscontext);
928 kfree(rootcontext);
929 return rc;
930 }
931 /*
932 * string mount options parsing and call set the sbsec
933 */
934 static int superblock_doinit(struct super_block *sb, void *data)
935 {
936 int rc = 0;
937 char *options = data;
938 struct security_mnt_opts opts;
939
940 security_init_mnt_opts(&opts);
941
942 if (!data)
943 goto out;
944
945 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
946
947 rc = selinux_parse_opts_str(options, &opts);
948 if (rc)
949 goto out_err;
950
951 out:
952 rc = selinux_set_mnt_opts(sb, &opts);
953
954 out_err:
955 security_free_mnt_opts(&opts);
956 return rc;
957 }
958
959 static void selinux_write_opts(struct seq_file *m,
960 struct security_mnt_opts *opts)
961 {
962 int i;
963 char *prefix;
964
965 for (i = 0; i < opts->num_mnt_opts; i++) {
966 char *has_comma;
967
968 if (opts->mnt_opts[i])
969 has_comma = strchr(opts->mnt_opts[i], ',');
970 else
971 has_comma = NULL;
972
973 switch (opts->mnt_opts_flags[i]) {
974 case CONTEXT_MNT:
975 prefix = CONTEXT_STR;
976 break;
977 case FSCONTEXT_MNT:
978 prefix = FSCONTEXT_STR;
979 break;
980 case ROOTCONTEXT_MNT:
981 prefix = ROOTCONTEXT_STR;
982 break;
983 case DEFCONTEXT_MNT:
984 prefix = DEFCONTEXT_STR;
985 break;
986 case SE_SBLABELSUPP:
987 seq_putc(m, ',');
988 seq_puts(m, LABELSUPP_STR);
989 continue;
990 default:
991 BUG();
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_INET_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 task_has_capability(struct task_struct *tsk,
1420 const struct cred *cred,
1421 int cap, int audit)
1422 {
1423 struct common_audit_data ad;
1424 struct av_decision avd;
1425 u16 sclass;
1426 u32 sid = cred_sid(cred);
1427 u32 av = CAP_TO_MASK(cap);
1428 int rc;
1429
1430 COMMON_AUDIT_DATA_INIT(&ad, CAP);
1431 ad.tsk = tsk;
1432 ad.u.cap = cap;
1433
1434 switch (CAP_TO_INDEX(cap)) {
1435 case 0:
1436 sclass = SECCLASS_CAPABILITY;
1437 break;
1438 case 1:
1439 sclass = SECCLASS_CAPABILITY2;
1440 break;
1441 default:
1442 printk(KERN_ERR
1443 "SELinux: out of range capability %d\n", cap);
1444 BUG();
1445 }
1446
1447 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1448 if (audit == SECURITY_CAP_AUDIT)
1449 avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1450 return rc;
1451 }
1452
1453 /* Check whether a task is allowed to use a system operation. */
1454 static int task_has_system(struct task_struct *tsk,
1455 u32 perms)
1456 {
1457 u32 sid = task_sid(tsk);
1458
1459 return avc_has_perm(sid, SECINITSID_KERNEL,
1460 SECCLASS_SYSTEM, perms, NULL);
1461 }
1462
1463 /* Check whether a task has a particular permission to an inode.
1464 The 'adp' parameter is optional and allows other audit
1465 data to be passed (e.g. the dentry). */
1466 static int inode_has_perm(const struct cred *cred,
1467 struct inode *inode,
1468 u32 perms,
1469 struct common_audit_data *adp)
1470 {
1471 struct inode_security_struct *isec;
1472 struct common_audit_data ad;
1473 u32 sid;
1474
1475 validate_creds(cred);
1476
1477 if (unlikely(IS_PRIVATE(inode)))
1478 return 0;
1479
1480 sid = cred_sid(cred);
1481 isec = inode->i_security;
1482
1483 if (!adp) {
1484 adp = &ad;
1485 COMMON_AUDIT_DATA_INIT(&ad, FS);
1486 ad.u.fs.inode = inode;
1487 }
1488
1489 return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1490 }
1491
1492 /* Same as inode_has_perm, but pass explicit audit data containing
1493 the dentry to help the auditing code to more easily generate the
1494 pathname if needed. */
1495 static inline int dentry_has_perm(const struct cred *cred,
1496 struct vfsmount *mnt,
1497 struct dentry *dentry,
1498 u32 av)
1499 {
1500 struct inode *inode = dentry->d_inode;
1501 struct common_audit_data ad;
1502
1503 COMMON_AUDIT_DATA_INIT(&ad, FS);
1504 ad.u.fs.path.mnt = mnt;
1505 ad.u.fs.path.dentry = dentry;
1506 return inode_has_perm(cred, inode, av, &ad);
1507 }
1508
1509 /* Check whether a task can use an open file descriptor to
1510 access an inode in a given way. Check access to the
1511 descriptor itself, and then use dentry_has_perm to
1512 check a particular permission to the file.
1513 Access to the descriptor is implicitly granted if it
1514 has the same SID as the process. If av is zero, then
1515 access to the file is not checked, e.g. for cases
1516 where only the descriptor is affected like seek. */
1517 static int file_has_perm(const struct cred *cred,
1518 struct file *file,
1519 u32 av)
1520 {
1521 struct file_security_struct *fsec = file->f_security;
1522 struct inode *inode = file->f_path.dentry->d_inode;
1523 struct common_audit_data ad;
1524 u32 sid = cred_sid(cred);
1525 int rc;
1526
1527 COMMON_AUDIT_DATA_INIT(&ad, FS);
1528 ad.u.fs.path = file->f_path;
1529
1530 if (sid != fsec->sid) {
1531 rc = avc_has_perm(sid, fsec->sid,
1532 SECCLASS_FD,
1533 FD__USE,
1534 &ad);
1535 if (rc)
1536 goto out;
1537 }
1538
1539 /* av is zero if only checking access to the descriptor. */
1540 rc = 0;
1541 if (av)
1542 rc = inode_has_perm(cred, inode, av, &ad);
1543
1544 out:
1545 return rc;
1546 }
1547
1548 /* Check whether a task can create a file. */
1549 static int may_create(struct inode *dir,
1550 struct dentry *dentry,
1551 u16 tclass)
1552 {
1553 const struct task_security_struct *tsec = current_security();
1554 struct inode_security_struct *dsec;
1555 struct superblock_security_struct *sbsec;
1556 u32 sid, newsid;
1557 struct common_audit_data ad;
1558 int rc;
1559
1560 dsec = dir->i_security;
1561 sbsec = dir->i_sb->s_security;
1562
1563 sid = tsec->sid;
1564 newsid = tsec->create_sid;
1565
1566 COMMON_AUDIT_DATA_INIT(&ad, FS);
1567 ad.u.fs.path.dentry = dentry;
1568
1569 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1570 DIR__ADD_NAME | DIR__SEARCH,
1571 &ad);
1572 if (rc)
1573 return rc;
1574
1575 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
1576 rc = security_transition_sid(sid, dsec->sid, tclass, NULL, &newsid);
1577 if (rc)
1578 return rc;
1579 }
1580
1581 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1582 if (rc)
1583 return rc;
1584
1585 return avc_has_perm(newsid, sbsec->sid,
1586 SECCLASS_FILESYSTEM,
1587 FILESYSTEM__ASSOCIATE, &ad);
1588 }
1589
1590 /* Check whether a task can create a key. */
1591 static int may_create_key(u32 ksid,
1592 struct task_struct *ctx)
1593 {
1594 u32 sid = task_sid(ctx);
1595
1596 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1597 }
1598
1599 #define MAY_LINK 0
1600 #define MAY_UNLINK 1
1601 #define MAY_RMDIR 2
1602
1603 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1604 static int may_link(struct inode *dir,
1605 struct dentry *dentry,
1606 int kind)
1607
1608 {
1609 struct inode_security_struct *dsec, *isec;
1610 struct common_audit_data ad;
1611 u32 sid = current_sid();
1612 u32 av;
1613 int rc;
1614
1615 dsec = dir->i_security;
1616 isec = dentry->d_inode->i_security;
1617
1618 COMMON_AUDIT_DATA_INIT(&ad, FS);
1619 ad.u.fs.path.dentry = dentry;
1620
1621 av = DIR__SEARCH;
1622 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1623 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1624 if (rc)
1625 return rc;
1626
1627 switch (kind) {
1628 case MAY_LINK:
1629 av = FILE__LINK;
1630 break;
1631 case MAY_UNLINK:
1632 av = FILE__UNLINK;
1633 break;
1634 case MAY_RMDIR:
1635 av = DIR__RMDIR;
1636 break;
1637 default:
1638 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n",
1639 __func__, kind);
1640 return 0;
1641 }
1642
1643 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1644 return rc;
1645 }
1646
1647 static inline int may_rename(struct inode *old_dir,
1648 struct dentry *old_dentry,
1649 struct inode *new_dir,
1650 struct dentry *new_dentry)
1651 {
1652 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1653 struct common_audit_data ad;
1654 u32 sid = current_sid();
1655 u32 av;
1656 int old_is_dir, new_is_dir;
1657 int rc;
1658
1659 old_dsec = old_dir->i_security;
1660 old_isec = old_dentry->d_inode->i_security;
1661 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1662 new_dsec = new_dir->i_security;
1663
1664 COMMON_AUDIT_DATA_INIT(&ad, FS);
1665
1666 ad.u.fs.path.dentry = old_dentry;
1667 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1668 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1669 if (rc)
1670 return rc;
1671 rc = avc_has_perm(sid, old_isec->sid,
1672 old_isec->sclass, FILE__RENAME, &ad);
1673 if (rc)
1674 return rc;
1675 if (old_is_dir && new_dir != old_dir) {
1676 rc = avc_has_perm(sid, old_isec->sid,
1677 old_isec->sclass, DIR__REPARENT, &ad);
1678 if (rc)
1679 return rc;
1680 }
1681
1682 ad.u.fs.path.dentry = new_dentry;
1683 av = DIR__ADD_NAME | DIR__SEARCH;
1684 if (new_dentry->d_inode)
1685 av |= DIR__REMOVE_NAME;
1686 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1687 if (rc)
1688 return rc;
1689 if (new_dentry->d_inode) {
1690 new_isec = new_dentry->d_inode->i_security;
1691 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1692 rc = avc_has_perm(sid, new_isec->sid,
1693 new_isec->sclass,
1694 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1695 if (rc)
1696 return rc;
1697 }
1698
1699 return 0;
1700 }
1701
1702 /* Check whether a task can perform a filesystem operation. */
1703 static int superblock_has_perm(const struct cred *cred,
1704 struct super_block *sb,
1705 u32 perms,
1706 struct common_audit_data *ad)
1707 {
1708 struct superblock_security_struct *sbsec;
1709 u32 sid = cred_sid(cred);
1710
1711 sbsec = sb->s_security;
1712 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1713 }
1714
1715 /* Convert a Linux mode and permission mask to an access vector. */
1716 static inline u32 file_mask_to_av(int mode, int mask)
1717 {
1718 u32 av = 0;
1719
1720 if ((mode & S_IFMT) != S_IFDIR) {
1721 if (mask & MAY_EXEC)
1722 av |= FILE__EXECUTE;
1723 if (mask & MAY_READ)
1724 av |= FILE__READ;
1725
1726 if (mask & MAY_APPEND)
1727 av |= FILE__APPEND;
1728 else if (mask & MAY_WRITE)
1729 av |= FILE__WRITE;
1730
1731 } else {
1732 if (mask & MAY_EXEC)
1733 av |= DIR__SEARCH;
1734 if (mask & MAY_WRITE)
1735 av |= DIR__WRITE;
1736 if (mask & MAY_READ)
1737 av |= DIR__READ;
1738 }
1739
1740 return av;
1741 }
1742
1743 /* Convert a Linux file to an access vector. */
1744 static inline u32 file_to_av(struct file *file)
1745 {
1746 u32 av = 0;
1747
1748 if (file->f_mode & FMODE_READ)
1749 av |= FILE__READ;
1750 if (file->f_mode & FMODE_WRITE) {
1751 if (file->f_flags & O_APPEND)
1752 av |= FILE__APPEND;
1753 else
1754 av |= FILE__WRITE;
1755 }
1756 if (!av) {
1757 /*
1758 * Special file opened with flags 3 for ioctl-only use.
1759 */
1760 av = FILE__IOCTL;
1761 }
1762
1763 return av;
1764 }
1765
1766 /*
1767 * Convert a file to an access vector and include the correct open
1768 * open permission.
1769 */
1770 static inline u32 open_file_to_av(struct file *file)
1771 {
1772 u32 av = file_to_av(file);
1773
1774 if (selinux_policycap_openperm)
1775 av |= FILE__OPEN;
1776
1777 return av;
1778 }
1779
1780 /* Hook functions begin here. */
1781
1782 static int selinux_ptrace_access_check(struct task_struct *child,
1783 unsigned int mode)
1784 {
1785 int rc;
1786
1787 rc = cap_ptrace_access_check(child, mode);
1788 if (rc)
1789 return rc;
1790
1791 if (mode == PTRACE_MODE_READ) {
1792 u32 sid = current_sid();
1793 u32 csid = task_sid(child);
1794 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
1795 }
1796
1797 return current_has_perm(child, PROCESS__PTRACE);
1798 }
1799
1800 static int selinux_ptrace_traceme(struct task_struct *parent)
1801 {
1802 int rc;
1803
1804 rc = cap_ptrace_traceme(parent);
1805 if (rc)
1806 return rc;
1807
1808 return task_has_perm(parent, current, PROCESS__PTRACE);
1809 }
1810
1811 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1812 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1813 {
1814 int error;
1815
1816 error = current_has_perm(target, PROCESS__GETCAP);
1817 if (error)
1818 return error;
1819
1820 return cap_capget(target, effective, inheritable, permitted);
1821 }
1822
1823 static int selinux_capset(struct cred *new, const struct cred *old,
1824 const kernel_cap_t *effective,
1825 const kernel_cap_t *inheritable,
1826 const kernel_cap_t *permitted)
1827 {
1828 int error;
1829
1830 error = cap_capset(new, old,
1831 effective, inheritable, permitted);
1832 if (error)
1833 return error;
1834
1835 return cred_has_perm(old, new, PROCESS__SETCAP);
1836 }
1837
1838 /*
1839 * (This comment used to live with the selinux_task_setuid hook,
1840 * which was removed).
1841 *
1842 * Since setuid only affects the current process, and since the SELinux
1843 * controls are not based on the Linux identity attributes, SELinux does not
1844 * need to control this operation. However, SELinux does control the use of
1845 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
1846 */
1847
1848 static int selinux_capable(struct task_struct *tsk, const struct cred *cred,
1849 int cap, int audit)
1850 {
1851 int rc;
1852
1853 rc = cap_capable(tsk, cred, cap, audit);
1854 if (rc)
1855 return rc;
1856
1857 return task_has_capability(tsk, cred, cap, audit);
1858 }
1859
1860 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1861 {
1862 const struct cred *cred = current_cred();
1863 int rc = 0;
1864
1865 if (!sb)
1866 return 0;
1867
1868 switch (cmds) {
1869 case Q_SYNC:
1870 case Q_QUOTAON:
1871 case Q_QUOTAOFF:
1872 case Q_SETINFO:
1873 case Q_SETQUOTA:
1874 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
1875 break;
1876 case Q_GETFMT:
1877 case Q_GETINFO:
1878 case Q_GETQUOTA:
1879 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
1880 break;
1881 default:
1882 rc = 0; /* let the kernel handle invalid cmds */
1883 break;
1884 }
1885 return rc;
1886 }
1887
1888 static int selinux_quota_on(struct dentry *dentry)
1889 {
1890 const struct cred *cred = current_cred();
1891
1892 return dentry_has_perm(cred, NULL, dentry, FILE__QUOTAON);
1893 }
1894
1895 static int selinux_syslog(int type)
1896 {
1897 int rc;
1898
1899 switch (type) {
1900 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
1901 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
1902 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1903 break;
1904 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
1905 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */
1906 /* Set level of messages printed to console */
1907 case SYSLOG_ACTION_CONSOLE_LEVEL:
1908 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1909 break;
1910 case SYSLOG_ACTION_CLOSE: /* Close log */
1911 case SYSLOG_ACTION_OPEN: /* Open log */
1912 case SYSLOG_ACTION_READ: /* Read from log */
1913 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */
1914 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */
1915 default:
1916 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1917 break;
1918 }
1919 return rc;
1920 }
1921
1922 /*
1923 * Check that a process has enough memory to allocate a new virtual
1924 * mapping. 0 means there is enough memory for the allocation to
1925 * succeed and -ENOMEM implies there is not.
1926 *
1927 * Do not audit the selinux permission check, as this is applied to all
1928 * processes that allocate mappings.
1929 */
1930 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
1931 {
1932 int rc, cap_sys_admin = 0;
1933
1934 rc = selinux_capable(current, current_cred(), CAP_SYS_ADMIN,
1935 SECURITY_CAP_NOAUDIT);
1936 if (rc == 0)
1937 cap_sys_admin = 1;
1938
1939 return __vm_enough_memory(mm, pages, cap_sys_admin);
1940 }
1941
1942 /* binprm security operations */
1943
1944 static int selinux_bprm_set_creds(struct linux_binprm *bprm)
1945 {
1946 const struct task_security_struct *old_tsec;
1947 struct task_security_struct *new_tsec;
1948 struct inode_security_struct *isec;
1949 struct common_audit_data ad;
1950 struct inode *inode = bprm->file->f_path.dentry->d_inode;
1951 int rc;
1952
1953 rc = cap_bprm_set_creds(bprm);
1954 if (rc)
1955 return rc;
1956
1957 /* SELinux context only depends on initial program or script and not
1958 * the script interpreter */
1959 if (bprm->cred_prepared)
1960 return 0;
1961
1962 old_tsec = current_security();
1963 new_tsec = bprm->cred->security;
1964 isec = inode->i_security;
1965
1966 /* Default to the current task SID. */
1967 new_tsec->sid = old_tsec->sid;
1968 new_tsec->osid = old_tsec->sid;
1969
1970 /* Reset fs, key, and sock SIDs on execve. */
1971 new_tsec->create_sid = 0;
1972 new_tsec->keycreate_sid = 0;
1973 new_tsec->sockcreate_sid = 0;
1974
1975 if (old_tsec->exec_sid) {
1976 new_tsec->sid = old_tsec->exec_sid;
1977 /* Reset exec SID on execve. */
1978 new_tsec->exec_sid = 0;
1979 } else {
1980 /* Check for a default transition on this program. */
1981 rc = security_transition_sid(old_tsec->sid, isec->sid,
1982 SECCLASS_PROCESS, NULL,
1983 &new_tsec->sid);
1984 if (rc)
1985 return rc;
1986 }
1987
1988 COMMON_AUDIT_DATA_INIT(&ad, FS);
1989 ad.u.fs.path = bprm->file->f_path;
1990
1991 if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
1992 new_tsec->sid = old_tsec->sid;
1993
1994 if (new_tsec->sid == old_tsec->sid) {
1995 rc = avc_has_perm(old_tsec->sid, isec->sid,
1996 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1997 if (rc)
1998 return rc;
1999 } else {
2000 /* Check permissions for the transition. */
2001 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2002 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2003 if (rc)
2004 return rc;
2005
2006 rc = avc_has_perm(new_tsec->sid, isec->sid,
2007 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2008 if (rc)
2009 return rc;
2010
2011 /* Check for shared state */
2012 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2013 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2014 SECCLASS_PROCESS, PROCESS__SHARE,
2015 NULL);
2016 if (rc)
2017 return -EPERM;
2018 }
2019
2020 /* Make sure that anyone attempting to ptrace over a task that
2021 * changes its SID has the appropriate permit */
2022 if (bprm->unsafe &
2023 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2024 struct task_struct *tracer;
2025 struct task_security_struct *sec;
2026 u32 ptsid = 0;
2027
2028 rcu_read_lock();
2029 tracer = tracehook_tracer_task(current);
2030 if (likely(tracer != NULL)) {
2031 sec = __task_cred(tracer)->security;
2032 ptsid = sec->sid;
2033 }
2034 rcu_read_unlock();
2035
2036 if (ptsid != 0) {
2037 rc = avc_has_perm(ptsid, new_tsec->sid,
2038 SECCLASS_PROCESS,
2039 PROCESS__PTRACE, NULL);
2040 if (rc)
2041 return -EPERM;
2042 }
2043 }
2044
2045 /* Clear any possibly unsafe personality bits on exec: */
2046 bprm->per_clear |= PER_CLEAR_ON_SETID;
2047 }
2048
2049 return 0;
2050 }
2051
2052 static int selinux_bprm_secureexec(struct linux_binprm *bprm)
2053 {
2054 const struct task_security_struct *tsec = current_security();
2055 u32 sid, osid;
2056 int atsecure = 0;
2057
2058 sid = tsec->sid;
2059 osid = tsec->osid;
2060
2061 if (osid != sid) {
2062 /* Enable secure mode for SIDs transitions unless
2063 the noatsecure permission is granted between
2064 the two SIDs, i.e. ahp returns 0. */
2065 atsecure = avc_has_perm(osid, sid,
2066 SECCLASS_PROCESS,
2067 PROCESS__NOATSECURE, NULL);
2068 }
2069
2070 return (atsecure || cap_bprm_secureexec(bprm));
2071 }
2072
2073 extern struct vfsmount *selinuxfs_mount;
2074 extern struct dentry *selinux_null;
2075
2076 /* Derived from fs/exec.c:flush_old_files. */
2077 static inline void flush_unauthorized_files(const struct cred *cred,
2078 struct files_struct *files)
2079 {
2080 struct common_audit_data ad;
2081 struct file *file, *devnull = NULL;
2082 struct tty_struct *tty;
2083 struct fdtable *fdt;
2084 long j = -1;
2085 int drop_tty = 0;
2086
2087 tty = get_current_tty();
2088 if (tty) {
2089 spin_lock(&tty_files_lock);
2090 if (!list_empty(&tty->tty_files)) {
2091 struct tty_file_private *file_priv;
2092 struct inode *inode;
2093
2094 /* Revalidate access to controlling tty.
2095 Use inode_has_perm on the tty inode directly rather
2096 than using file_has_perm, as this particular open
2097 file may belong to another process and we are only
2098 interested in the inode-based check here. */
2099 file_priv = list_first_entry(&tty->tty_files,
2100 struct tty_file_private, list);
2101 file = file_priv->file;
2102 inode = file->f_path.dentry->d_inode;
2103 if (inode_has_perm(cred, inode,
2104 FILE__READ | FILE__WRITE, NULL)) {
2105 drop_tty = 1;
2106 }
2107 }
2108 spin_unlock(&tty_files_lock);
2109 tty_kref_put(tty);
2110 }
2111 /* Reset controlling tty. */
2112 if (drop_tty)
2113 no_tty();
2114
2115 /* Revalidate access to inherited open files. */
2116
2117 COMMON_AUDIT_DATA_INIT(&ad, FS);
2118
2119 spin_lock(&files->file_lock);
2120 for (;;) {
2121 unsigned long set, i;
2122 int fd;
2123
2124 j++;
2125 i = j * __NFDBITS;
2126 fdt = files_fdtable(files);
2127 if (i >= fdt->max_fds)
2128 break;
2129 set = fdt->open_fds->fds_bits[j];
2130 if (!set)
2131 continue;
2132 spin_unlock(&files->file_lock);
2133 for ( ; set ; i++, set >>= 1) {
2134 if (set & 1) {
2135 file = fget(i);
2136 if (!file)
2137 continue;
2138 if (file_has_perm(cred,
2139 file,
2140 file_to_av(file))) {
2141 sys_close(i);
2142 fd = get_unused_fd();
2143 if (fd != i) {
2144 if (fd >= 0)
2145 put_unused_fd(fd);
2146 fput(file);
2147 continue;
2148 }
2149 if (devnull) {
2150 get_file(devnull);
2151 } else {
2152 devnull = dentry_open(
2153 dget(selinux_null),
2154 mntget(selinuxfs_mount),
2155 O_RDWR, cred);
2156 if (IS_ERR(devnull)) {
2157 devnull = NULL;
2158 put_unused_fd(fd);
2159 fput(file);
2160 continue;
2161 }
2162 }
2163 fd_install(fd, devnull);
2164 }
2165 fput(file);
2166 }
2167 }
2168 spin_lock(&files->file_lock);
2169
2170 }
2171 spin_unlock(&files->file_lock);
2172 }
2173
2174 /*
2175 * Prepare a process for imminent new credential changes due to exec
2176 */
2177 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2178 {
2179 struct task_security_struct *new_tsec;
2180 struct rlimit *rlim, *initrlim;
2181 int rc, i;
2182
2183 new_tsec = bprm->cred->security;
2184 if (new_tsec->sid == new_tsec->osid)
2185 return;
2186
2187 /* Close files for which the new task SID is not authorized. */
2188 flush_unauthorized_files(bprm->cred, current->files);
2189
2190 /* Always clear parent death signal on SID transitions. */
2191 current->pdeath_signal = 0;
2192
2193 /* Check whether the new SID can inherit resource limits from the old
2194 * SID. If not, reset all soft limits to the lower of the current
2195 * task's hard limit and the init task's soft limit.
2196 *
2197 * Note that the setting of hard limits (even to lower them) can be
2198 * controlled by the setrlimit check. The inclusion of the init task's
2199 * soft limit into the computation is to avoid resetting soft limits
2200 * higher than the default soft limit for cases where the default is
2201 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2202 */
2203 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2204 PROCESS__RLIMITINH, NULL);
2205 if (rc) {
2206 /* protect against do_prlimit() */
2207 task_lock(current);
2208 for (i = 0; i < RLIM_NLIMITS; i++) {
2209 rlim = current->signal->rlim + i;
2210 initrlim = init_task.signal->rlim + i;
2211 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2212 }
2213 task_unlock(current);
2214 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2215 }
2216 }
2217
2218 /*
2219 * Clean up the process immediately after the installation of new credentials
2220 * due to exec
2221 */
2222 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2223 {
2224 const struct task_security_struct *tsec = current_security();
2225 struct itimerval itimer;
2226 u32 osid, sid;
2227 int rc, i;
2228
2229 osid = tsec->osid;
2230 sid = tsec->sid;
2231
2232 if (sid == osid)
2233 return;
2234
2235 /* Check whether the new SID can inherit signal state from the old SID.
2236 * If not, clear itimers to avoid subsequent signal generation and
2237 * flush and unblock signals.
2238 *
2239 * This must occur _after_ the task SID has been updated so that any
2240 * kill done after the flush will be checked against the new SID.
2241 */
2242 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2243 if (rc) {
2244 memset(&itimer, 0, sizeof itimer);
2245 for (i = 0; i < 3; i++)
2246 do_setitimer(i, &itimer, NULL);
2247 spin_lock_irq(&current->sighand->siglock);
2248 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
2249 __flush_signals(current);
2250 flush_signal_handlers(current, 1);
2251 sigemptyset(&current->blocked);
2252 }
2253 spin_unlock_irq(&current->sighand->siglock);
2254 }
2255
2256 /* Wake up the parent if it is waiting so that it can recheck
2257 * wait permission to the new task SID. */
2258 read_lock(&tasklist_lock);
2259 __wake_up_parent(current, current->real_parent);
2260 read_unlock(&tasklist_lock);
2261 }
2262
2263 /* superblock security operations */
2264
2265 static int selinux_sb_alloc_security(struct super_block *sb)
2266 {
2267 return superblock_alloc_security(sb);
2268 }
2269
2270 static void selinux_sb_free_security(struct super_block *sb)
2271 {
2272 superblock_free_security(sb);
2273 }
2274
2275 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2276 {
2277 if (plen > olen)
2278 return 0;
2279
2280 return !memcmp(prefix, option, plen);
2281 }
2282
2283 static inline int selinux_option(char *option, int len)
2284 {
2285 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2286 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2287 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2288 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2289 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
2290 }
2291
2292 static inline void take_option(char **to, char *from, int *first, int len)
2293 {
2294 if (!*first) {
2295 **to = ',';
2296 *to += 1;
2297 } else
2298 *first = 0;
2299 memcpy(*to, from, len);
2300 *to += len;
2301 }
2302
2303 static inline void take_selinux_option(char **to, char *from, int *first,
2304 int len)
2305 {
2306 int current_size = 0;
2307
2308 if (!*first) {
2309 **to = '|';
2310 *to += 1;
2311 } else
2312 *first = 0;
2313
2314 while (current_size < len) {
2315 if (*from != '"') {
2316 **to = *from;
2317 *to += 1;
2318 }
2319 from += 1;
2320 current_size += 1;
2321 }
2322 }
2323
2324 static int selinux_sb_copy_data(char *orig, char *copy)
2325 {
2326 int fnosec, fsec, rc = 0;
2327 char *in_save, *in_curr, *in_end;
2328 char *sec_curr, *nosec_save, *nosec;
2329 int open_quote = 0;
2330
2331 in_curr = orig;
2332 sec_curr = copy;
2333
2334 nosec = (char *)get_zeroed_page(GFP_KERNEL);
2335 if (!nosec) {
2336 rc = -ENOMEM;
2337 goto out;
2338 }
2339
2340 nosec_save = nosec;
2341 fnosec = fsec = 1;
2342 in_save = in_end = orig;
2343
2344 do {
2345 if (*in_end == '"')
2346 open_quote = !open_quote;
2347 if ((*in_end == ',' && open_quote == 0) ||
2348 *in_end == '\0') {
2349 int len = in_end - in_curr;
2350
2351 if (selinux_option(in_curr, len))
2352 take_selinux_option(&sec_curr, in_curr, &fsec, len);
2353 else
2354 take_option(&nosec, in_curr, &fnosec, len);
2355
2356 in_curr = in_end + 1;
2357 }
2358 } while (*in_end++);
2359
2360 strcpy(in_save, nosec_save);
2361 free_page((unsigned long)nosec_save);
2362 out:
2363 return rc;
2364 }
2365
2366 static int selinux_sb_remount(struct super_block *sb, void *data)
2367 {
2368 int rc, i, *flags;
2369 struct security_mnt_opts opts;
2370 char *secdata, **mount_options;
2371 struct superblock_security_struct *sbsec = sb->s_security;
2372
2373 if (!(sbsec->flags & SE_SBINITIALIZED))
2374 return 0;
2375
2376 if (!data)
2377 return 0;
2378
2379 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
2380 return 0;
2381
2382 security_init_mnt_opts(&opts);
2383 secdata = alloc_secdata();
2384 if (!secdata)
2385 return -ENOMEM;
2386 rc = selinux_sb_copy_data(data, secdata);
2387 if (rc)
2388 goto out_free_secdata;
2389
2390 rc = selinux_parse_opts_str(secdata, &opts);
2391 if (rc)
2392 goto out_free_secdata;
2393
2394 mount_options = opts.mnt_opts;
2395 flags = opts.mnt_opts_flags;
2396
2397 for (i = 0; i < opts.num_mnt_opts; i++) {
2398 u32 sid;
2399 size_t len;
2400
2401 if (flags[i] == SE_SBLABELSUPP)
2402 continue;
2403 len = strlen(mount_options[i]);
2404 rc = security_context_to_sid(mount_options[i], len, &sid);
2405 if (rc) {
2406 printk(KERN_WARNING "SELinux: security_context_to_sid"
2407 "(%s) failed for (dev %s, type %s) errno=%d\n",
2408 mount_options[i], sb->s_id, sb->s_type->name, rc);
2409 goto out_free_opts;
2410 }
2411 rc = -EINVAL;
2412 switch (flags[i]) {
2413 case FSCONTEXT_MNT:
2414 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
2415 goto out_bad_option;
2416 break;
2417 case CONTEXT_MNT:
2418 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
2419 goto out_bad_option;
2420 break;
2421 case ROOTCONTEXT_MNT: {
2422 struct inode_security_struct *root_isec;
2423 root_isec = sb->s_root->d_inode->i_security;
2424
2425 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
2426 goto out_bad_option;
2427 break;
2428 }
2429 case DEFCONTEXT_MNT:
2430 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
2431 goto out_bad_option;
2432 break;
2433 default:
2434 goto out_free_opts;
2435 }
2436 }
2437
2438 rc = 0;
2439 out_free_opts:
2440 security_free_mnt_opts(&opts);
2441 out_free_secdata:
2442 free_secdata(secdata);
2443 return rc;
2444 out_bad_option:
2445 printk(KERN_WARNING "SELinux: unable to change security options "
2446 "during remount (dev %s, type=%s)\n", sb->s_id,
2447 sb->s_type->name);
2448 goto out_free_opts;
2449 }
2450
2451 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
2452 {
2453 const struct cred *cred = current_cred();
2454 struct common_audit_data ad;
2455 int rc;
2456
2457 rc = superblock_doinit(sb, data);
2458 if (rc)
2459 return rc;
2460
2461 /* Allow all mounts performed by the kernel */
2462 if (flags & MS_KERNMOUNT)
2463 return 0;
2464
2465 COMMON_AUDIT_DATA_INIT(&ad, FS);
2466 ad.u.fs.path.dentry = sb->s_root;
2467 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2468 }
2469
2470 static int selinux_sb_statfs(struct dentry *dentry)
2471 {
2472 const struct cred *cred = current_cred();
2473 struct common_audit_data ad;
2474
2475 COMMON_AUDIT_DATA_INIT(&ad, FS);
2476 ad.u.fs.path.dentry = dentry->d_sb->s_root;
2477 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2478 }
2479
2480 static int selinux_mount(char *dev_name,
2481 struct path *path,
2482 char *type,
2483 unsigned long flags,
2484 void *data)
2485 {
2486 const struct cred *cred = current_cred();
2487
2488 if (flags & MS_REMOUNT)
2489 return superblock_has_perm(cred, path->mnt->mnt_sb,
2490 FILESYSTEM__REMOUNT, NULL);
2491 else
2492 return dentry_has_perm(cred, path->mnt, path->dentry,
2493 FILE__MOUNTON);
2494 }
2495
2496 static int selinux_umount(struct vfsmount *mnt, int flags)
2497 {
2498 const struct cred *cred = current_cred();
2499
2500 return superblock_has_perm(cred, mnt->mnt_sb,
2501 FILESYSTEM__UNMOUNT, NULL);
2502 }
2503
2504 /* inode security operations */
2505
2506 static int selinux_inode_alloc_security(struct inode *inode)
2507 {
2508 return inode_alloc_security(inode);
2509 }
2510
2511 static void selinux_inode_free_security(struct inode *inode)
2512 {
2513 inode_free_security(inode);
2514 }
2515
2516 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2517 const struct qstr *qstr, char **name,
2518 void **value, size_t *len)
2519 {
2520 const struct task_security_struct *tsec = current_security();
2521 struct inode_security_struct *dsec;
2522 struct superblock_security_struct *sbsec;
2523 u32 sid, newsid, clen;
2524 int rc;
2525 char *namep = NULL, *context;
2526
2527 dsec = dir->i_security;
2528 sbsec = dir->i_sb->s_security;
2529
2530 sid = tsec->sid;
2531 newsid = tsec->create_sid;
2532
2533 if ((sbsec->flags & SE_SBINITIALIZED) &&
2534 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
2535 newsid = sbsec->mntpoint_sid;
2536 else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
2537 rc = security_transition_sid(sid, dsec->sid,
2538 inode_mode_to_security_class(inode->i_mode),
2539 qstr, &newsid);
2540 if (rc) {
2541 printk(KERN_WARNING "%s: "
2542 "security_transition_sid failed, rc=%d (dev=%s "
2543 "ino=%ld)\n",
2544 __func__,
2545 -rc, inode->i_sb->s_id, inode->i_ino);
2546 return rc;
2547 }
2548 }
2549
2550 /* Possibly defer initialization to selinux_complete_init. */
2551 if (sbsec->flags & SE_SBINITIALIZED) {
2552 struct inode_security_struct *isec = inode->i_security;
2553 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2554 isec->sid = newsid;
2555 isec->initialized = 1;
2556 }
2557
2558 if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
2559 return -EOPNOTSUPP;
2560
2561 if (name) {
2562 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
2563 if (!namep)
2564 return -ENOMEM;
2565 *name = namep;
2566 }
2567
2568 if (value && len) {
2569 rc = security_sid_to_context_force(newsid, &context, &clen);
2570 if (rc) {
2571 kfree(namep);
2572 return rc;
2573 }
2574 *value = context;
2575 *len = clen;
2576 }
2577
2578 return 0;
2579 }
2580
2581 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2582 {
2583 return may_create(dir, dentry, SECCLASS_FILE);
2584 }
2585
2586 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2587 {
2588 return may_link(dir, old_dentry, MAY_LINK);
2589 }
2590
2591 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2592 {
2593 return may_link(dir, dentry, MAY_UNLINK);
2594 }
2595
2596 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2597 {
2598 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2599 }
2600
2601 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2602 {
2603 return may_create(dir, dentry, SECCLASS_DIR);
2604 }
2605
2606 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2607 {
2608 return may_link(dir, dentry, MAY_RMDIR);
2609 }
2610
2611 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2612 {
2613 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2614 }
2615
2616 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2617 struct inode *new_inode, struct dentry *new_dentry)
2618 {
2619 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2620 }
2621
2622 static int selinux_inode_readlink(struct dentry *dentry)
2623 {
2624 const struct cred *cred = current_cred();
2625
2626 return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2627 }
2628
2629 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2630 {
2631 const struct cred *cred = current_cred();
2632
2633 return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2634 }
2635
2636 static int selinux_inode_permission(struct inode *inode, int mask)
2637 {
2638 const struct cred *cred = current_cred();
2639 struct common_audit_data ad;
2640 u32 perms;
2641 bool from_access;
2642
2643 from_access = mask & MAY_ACCESS;
2644 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
2645
2646 /* No permission to check. Existence test. */
2647 if (!mask)
2648 return 0;
2649
2650 COMMON_AUDIT_DATA_INIT(&ad, FS);
2651 ad.u.fs.inode = inode;
2652
2653 if (from_access)
2654 ad.selinux_audit_data.auditdeny |= FILE__AUDIT_ACCESS;
2655
2656 perms = file_mask_to_av(inode->i_mode, mask);
2657
2658 return inode_has_perm(cred, inode, perms, &ad);
2659 }
2660
2661 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2662 {
2663 const struct cred *cred = current_cred();
2664 unsigned int ia_valid = iattr->ia_valid;
2665
2666 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2667 if (ia_valid & ATTR_FORCE) {
2668 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2669 ATTR_FORCE);
2670 if (!ia_valid)
2671 return 0;
2672 }
2673
2674 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2675 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2676 return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2677
2678 return dentry_has_perm(cred, NULL, dentry, FILE__WRITE);
2679 }
2680
2681 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2682 {
2683 const struct cred *cred = current_cred();
2684
2685 return dentry_has_perm(cred, mnt, dentry, FILE__GETATTR);
2686 }
2687
2688 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2689 {
2690 const struct cred *cred = current_cred();
2691
2692 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2693 sizeof XATTR_SECURITY_PREFIX - 1)) {
2694 if (!strcmp(name, XATTR_NAME_CAPS)) {
2695 if (!capable(CAP_SETFCAP))
2696 return -EPERM;
2697 } else if (!capable(CAP_SYS_ADMIN)) {
2698 /* A different attribute in the security namespace.
2699 Restrict to administrator. */
2700 return -EPERM;
2701 }
2702 }
2703
2704 /* Not an attribute we recognize, so just check the
2705 ordinary setattr permission. */
2706 return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2707 }
2708
2709 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2710 const void *value, size_t size, int flags)
2711 {
2712 struct inode *inode = dentry->d_inode;
2713 struct inode_security_struct *isec = inode->i_security;
2714 struct superblock_security_struct *sbsec;
2715 struct common_audit_data ad;
2716 u32 newsid, sid = current_sid();
2717 int rc = 0;
2718
2719 if (strcmp(name, XATTR_NAME_SELINUX))
2720 return selinux_inode_setotherxattr(dentry, name);
2721
2722 sbsec = inode->i_sb->s_security;
2723 if (!(sbsec->flags & SE_SBLABELSUPP))
2724 return -EOPNOTSUPP;
2725
2726 if (!is_owner_or_cap(inode))
2727 return -EPERM;
2728
2729 COMMON_AUDIT_DATA_INIT(&ad, FS);
2730 ad.u.fs.path.dentry = dentry;
2731
2732 rc = avc_has_perm(sid, isec->sid, isec->sclass,
2733 FILE__RELABELFROM, &ad);
2734 if (rc)
2735 return rc;
2736
2737 rc = security_context_to_sid(value, size, &newsid);
2738 if (rc == -EINVAL) {
2739 if (!capable(CAP_MAC_ADMIN))
2740 return rc;
2741 rc = security_context_to_sid_force(value, size, &newsid);
2742 }
2743 if (rc)
2744 return rc;
2745
2746 rc = avc_has_perm(sid, newsid, isec->sclass,
2747 FILE__RELABELTO, &ad);
2748 if (rc)
2749 return rc;
2750
2751 rc = security_validate_transition(isec->sid, newsid, sid,
2752 isec->sclass);
2753 if (rc)
2754 return rc;
2755
2756 return avc_has_perm(newsid,
2757 sbsec->sid,
2758 SECCLASS_FILESYSTEM,
2759 FILESYSTEM__ASSOCIATE,
2760 &ad);
2761 }
2762
2763 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2764 const void *value, size_t size,
2765 int flags)
2766 {
2767 struct inode *inode = dentry->d_inode;
2768 struct inode_security_struct *isec = inode->i_security;
2769 u32 newsid;
2770 int rc;
2771
2772 if (strcmp(name, XATTR_NAME_SELINUX)) {
2773 /* Not an attribute we recognize, so nothing to do. */
2774 return;
2775 }
2776
2777 rc = security_context_to_sid_force(value, size, &newsid);
2778 if (rc) {
2779 printk(KERN_ERR "SELinux: unable to map context to SID"
2780 "for (%s, %lu), rc=%d\n",
2781 inode->i_sb->s_id, inode->i_ino, -rc);
2782 return;
2783 }
2784
2785 isec->sid = newsid;
2786 return;
2787 }
2788
2789 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
2790 {
2791 const struct cred *cred = current_cred();
2792
2793 return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2794 }
2795
2796 static int selinux_inode_listxattr(struct dentry *dentry)
2797 {
2798 const struct cred *cred = current_cred();
2799
2800 return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2801 }
2802
2803 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
2804 {
2805 if (strcmp(name, XATTR_NAME_SELINUX))
2806 return selinux_inode_setotherxattr(dentry, name);
2807
2808 /* No one is allowed to remove a SELinux security label.
2809 You can change the label, but all data must be labeled. */
2810 return -EACCES;
2811 }
2812
2813 /*
2814 * Copy the inode security context value to the user.
2815 *
2816 * Permission check is handled by selinux_inode_getxattr hook.
2817 */
2818 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
2819 {
2820 u32 size;
2821 int error;
2822 char *context = NULL;
2823 struct inode_security_struct *isec = inode->i_security;
2824
2825 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2826 return -EOPNOTSUPP;
2827
2828 /*
2829 * If the caller has CAP_MAC_ADMIN, then get the raw context
2830 * value even if it is not defined by current policy; otherwise,
2831 * use the in-core value under current policy.
2832 * Use the non-auditing forms of the permission checks since
2833 * getxattr may be called by unprivileged processes commonly
2834 * and lack of permission just means that we fall back to the
2835 * in-core context value, not a denial.
2836 */
2837 error = selinux_capable(current, current_cred(), CAP_MAC_ADMIN,
2838 SECURITY_CAP_NOAUDIT);
2839 if (!error)
2840 error = security_sid_to_context_force(isec->sid, &context,
2841 &size);
2842 else
2843 error = security_sid_to_context(isec->sid, &context, &size);
2844 if (error)
2845 return error;
2846 error = size;
2847 if (alloc) {
2848 *buffer = context;
2849 goto out_nofree;
2850 }
2851 kfree(context);
2852 out_nofree:
2853 return error;
2854 }
2855
2856 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2857 const void *value, size_t size, int flags)
2858 {
2859 struct inode_security_struct *isec = inode->i_security;
2860 u32 newsid;
2861 int rc;
2862
2863 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2864 return -EOPNOTSUPP;
2865
2866 if (!value || !size)
2867 return -EACCES;
2868
2869 rc = security_context_to_sid((void *)value, size, &newsid);
2870 if (rc)
2871 return rc;
2872
2873 isec->sid = newsid;
2874 isec->initialized = 1;
2875 return 0;
2876 }
2877
2878 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2879 {
2880 const int len = sizeof(XATTR_NAME_SELINUX);
2881 if (buffer && len <= buffer_size)
2882 memcpy(buffer, XATTR_NAME_SELINUX, len);
2883 return len;
2884 }
2885
2886 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2887 {
2888 struct inode_security_struct *isec = inode->i_security;
2889 *secid = isec->sid;
2890 }
2891
2892 /* file security operations */
2893
2894 static int selinux_revalidate_file_permission(struct file *file, int mask)
2895 {
2896 const struct cred *cred = current_cred();
2897 struct inode *inode = file->f_path.dentry->d_inode;
2898
2899 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2900 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2901 mask |= MAY_APPEND;
2902
2903 return file_has_perm(cred, file,
2904 file_mask_to_av(inode->i_mode, mask));
2905 }
2906
2907 static int selinux_file_permission(struct file *file, int mask)
2908 {
2909 struct inode *inode = file->f_path.dentry->d_inode;
2910 struct file_security_struct *fsec = file->f_security;
2911 struct inode_security_struct *isec = inode->i_security;
2912 u32 sid = current_sid();
2913
2914 if (!mask)
2915 /* No permission to check. Existence test. */
2916 return 0;
2917
2918 if (sid == fsec->sid && fsec->isid == isec->sid &&
2919 fsec->pseqno == avc_policy_seqno())
2920 /* No change since dentry_open check. */
2921 return 0;
2922
2923 return selinux_revalidate_file_permission(file, mask);
2924 }
2925
2926 static int selinux_file_alloc_security(struct file *file)
2927 {
2928 return file_alloc_security(file);
2929 }
2930
2931 static void selinux_file_free_security(struct file *file)
2932 {
2933 file_free_security(file);
2934 }
2935
2936 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2937 unsigned long arg)
2938 {
2939 const struct cred *cred = current_cred();
2940 int error = 0;
2941
2942 switch (cmd) {
2943 case FIONREAD:
2944 /* fall through */
2945 case FIBMAP:
2946 /* fall through */
2947 case FIGETBSZ:
2948 /* fall through */
2949 case EXT2_IOC_GETFLAGS:
2950 /* fall through */
2951 case EXT2_IOC_GETVERSION:
2952 error = file_has_perm(cred, file, FILE__GETATTR);
2953 break;
2954
2955 case EXT2_IOC_SETFLAGS:
2956 /* fall through */
2957 case EXT2_IOC_SETVERSION:
2958 error = file_has_perm(cred, file, FILE__SETATTR);
2959 break;
2960
2961 /* sys_ioctl() checks */
2962 case FIONBIO:
2963 /* fall through */
2964 case FIOASYNC:
2965 error = file_has_perm(cred, file, 0);
2966 break;
2967
2968 case KDSKBENT:
2969 case KDSKBSENT:
2970 error = task_has_capability(current, cred, CAP_SYS_TTY_CONFIG,
2971 SECURITY_CAP_AUDIT);
2972 break;
2973
2974 /* default case assumes that the command will go
2975 * to the file's ioctl() function.
2976 */
2977 default:
2978 error = file_has_perm(cred, file, FILE__IOCTL);
2979 }
2980 return error;
2981 }
2982
2983 static int default_noexec;
2984
2985 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2986 {
2987 const struct cred *cred = current_cred();
2988 int rc = 0;
2989
2990 if (default_noexec &&
2991 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2992 /*
2993 * We are making executable an anonymous mapping or a
2994 * private file mapping that will also be writable.
2995 * This has an additional check.
2996 */
2997 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
2998 if (rc)
2999 goto error;
3000 }
3001
3002 if (file) {
3003 /* read access is always possible with a mapping */
3004 u32 av = FILE__READ;
3005
3006 /* write access only matters if the mapping is shared */
3007 if (shared && (prot & PROT_WRITE))
3008 av |= FILE__WRITE;
3009
3010 if (prot & PROT_EXEC)
3011 av |= FILE__EXECUTE;
3012
3013 return file_has_perm(cred, file, av);
3014 }
3015
3016 error:
3017 return rc;
3018 }
3019
3020 static int selinux_file_mmap(struct file *file, unsigned long reqprot,
3021 unsigned long prot, unsigned long flags,
3022 unsigned long addr, unsigned long addr_only)
3023 {
3024 int rc = 0;
3025 u32 sid = current_sid();
3026
3027 /*
3028 * notice that we are intentionally putting the SELinux check before
3029 * the secondary cap_file_mmap check. This is such a likely attempt
3030 * at bad behaviour/exploit that we always want to get the AVC, even
3031 * if DAC would have also denied the operation.
3032 */
3033 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3034 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3035 MEMPROTECT__MMAP_ZERO, NULL);
3036 if (rc)
3037 return rc;
3038 }
3039
3040 /* do DAC check on address space usage */
3041 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
3042 if (rc || addr_only)
3043 return rc;
3044
3045 if (selinux_checkreqprot)
3046 prot = reqprot;
3047
3048 return file_map_prot_check(file, prot,
3049 (flags & MAP_TYPE) == MAP_SHARED);
3050 }
3051
3052 static int selinux_file_mprotect(struct vm_area_struct *vma,
3053 unsigned long reqprot,
3054 unsigned long prot)
3055 {
3056 const struct cred *cred = current_cred();
3057
3058 if (selinux_checkreqprot)
3059 prot = reqprot;
3060
3061 if (default_noexec &&
3062 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3063 int rc = 0;
3064 if (vma->vm_start >= vma->vm_mm->start_brk &&
3065 vma->vm_end <= vma->vm_mm->brk) {
3066 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3067 } else if (!vma->vm_file &&
3068 vma->vm_start <= vma->vm_mm->start_stack &&
3069 vma->vm_end >= vma->vm_mm->start_stack) {
3070 rc = current_has_perm(current, PROCESS__EXECSTACK);
3071 } else if (vma->vm_file && vma->anon_vma) {
3072 /*
3073 * We are making executable a file mapping that has
3074 * had some COW done. Since pages might have been
3075 * written, check ability to execute the possibly
3076 * modified content. This typically should only
3077 * occur for text relocations.
3078 */
3079 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3080 }
3081 if (rc)
3082 return rc;
3083 }
3084
3085 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3086 }
3087
3088 static int selinux_file_lock(struct file *file, unsigned int cmd)
3089 {
3090 const struct cred *cred = current_cred();
3091
3092 return file_has_perm(cred, file, FILE__LOCK);
3093 }
3094
3095 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3096 unsigned long arg)
3097 {
3098 const struct cred *cred = current_cred();
3099 int err = 0;
3100
3101 switch (cmd) {
3102 case F_SETFL:
3103 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3104 err = -EINVAL;
3105 break;
3106 }
3107
3108 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3109 err = file_has_perm(cred, file, FILE__WRITE);
3110 break;
3111 }
3112 /* fall through */
3113 case F_SETOWN:
3114 case F_SETSIG:
3115 case F_GETFL:
3116 case F_GETOWN:
3117 case F_GETSIG:
3118 /* Just check FD__USE permission */
3119 err = file_has_perm(cred, file, 0);
3120 break;
3121 case F_GETLK:
3122 case F_SETLK:
3123 case F_SETLKW:
3124 #if BITS_PER_LONG == 32
3125 case F_GETLK64:
3126 case F_SETLK64:
3127 case F_SETLKW64:
3128 #endif
3129 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3130 err = -EINVAL;
3131 break;
3132 }
3133 err = file_has_perm(cred, file, FILE__LOCK);
3134 break;
3135 }
3136
3137 return err;
3138 }
3139
3140 static int selinux_file_set_fowner(struct file *file)
3141 {
3142 struct file_security_struct *fsec;
3143
3144 fsec = file->f_security;
3145 fsec->fown_sid = current_sid();
3146
3147 return 0;
3148 }
3149
3150 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3151 struct fown_struct *fown, int signum)
3152 {
3153 struct file *file;
3154 u32 sid = task_sid(tsk);
3155 u32 perm;
3156 struct file_security_struct *fsec;
3157
3158 /* struct fown_struct is never outside the context of a struct file */
3159 file = container_of(fown, struct file, f_owner);
3160
3161 fsec = file->f_security;
3162
3163 if (!signum)
3164 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3165 else
3166 perm = signal_to_av(signum);
3167
3168 return avc_has_perm(fsec->fown_sid, sid,
3169 SECCLASS_PROCESS, perm, NULL);
3170 }
3171
3172 static int selinux_file_receive(struct file *file)
3173 {
3174 const struct cred *cred = current_cred();
3175
3176 return file_has_perm(cred, file, file_to_av(file));
3177 }
3178
3179 static int selinux_dentry_open(struct file *file, const struct cred *cred)
3180 {
3181 struct file_security_struct *fsec;
3182 struct inode *inode;
3183 struct inode_security_struct *isec;
3184
3185 inode = file->f_path.dentry->d_inode;
3186 fsec = file->f_security;
3187 isec = inode->i_security;
3188 /*
3189 * Save inode label and policy sequence number
3190 * at open-time so that selinux_file_permission
3191 * can determine whether revalidation is necessary.
3192 * Task label is already saved in the file security
3193 * struct as its SID.
3194 */
3195 fsec->isid = isec->sid;
3196 fsec->pseqno = avc_policy_seqno();
3197 /*
3198 * Since the inode label or policy seqno may have changed
3199 * between the selinux_inode_permission check and the saving
3200 * of state above, recheck that access is still permitted.
3201 * Otherwise, access might never be revalidated against the
3202 * new inode label or new policy.
3203 * This check is not redundant - do not remove.
3204 */
3205 return inode_has_perm(cred, inode, open_file_to_av(file), NULL);
3206 }
3207
3208 /* task security operations */
3209
3210 static int selinux_task_create(unsigned long clone_flags)
3211 {
3212 return current_has_perm(current, PROCESS__FORK);
3213 }
3214
3215 /*
3216 * allocate the SELinux part of blank credentials
3217 */
3218 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3219 {
3220 struct task_security_struct *tsec;
3221
3222 tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3223 if (!tsec)
3224 return -ENOMEM;
3225
3226 cred->security = tsec;
3227 return 0;
3228 }
3229
3230 /*
3231 * detach and free the LSM part of a set of credentials
3232 */
3233 static void selinux_cred_free(struct cred *cred)
3234 {
3235 struct task_security_struct *tsec = cred->security;
3236
3237 BUG_ON((unsigned long) cred->security < PAGE_SIZE);
3238 cred->security = (void *) 0x7UL;
3239 kfree(tsec);
3240 }
3241
3242 /*
3243 * prepare a new set of credentials for modification
3244 */
3245 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3246 gfp_t gfp)
3247 {
3248 const struct task_security_struct *old_tsec;
3249 struct task_security_struct *tsec;
3250
3251 old_tsec = old->security;
3252
3253 tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3254 if (!tsec)
3255 return -ENOMEM;
3256
3257 new->security = tsec;
3258 return 0;
3259 }
3260
3261 /*
3262 * transfer the SELinux data to a blank set of creds
3263 */
3264 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3265 {
3266 const struct task_security_struct *old_tsec = old->security;
3267 struct task_security_struct *tsec = new->security;
3268
3269 *tsec = *old_tsec;
3270 }
3271
3272 /*
3273 * set the security data for a kernel service
3274 * - all the creation contexts are set to unlabelled
3275 */
3276 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3277 {
3278 struct task_security_struct *tsec = new->security;
3279 u32 sid = current_sid();
3280 int ret;
3281
3282 ret = avc_has_perm(sid, secid,
3283 SECCLASS_KERNEL_SERVICE,
3284 KERNEL_SERVICE__USE_AS_OVERRIDE,
3285 NULL);
3286 if (ret == 0) {
3287 tsec->sid = secid;
3288 tsec->create_sid = 0;
3289 tsec->keycreate_sid = 0;
3290 tsec->sockcreate_sid = 0;
3291 }
3292 return ret;
3293 }
3294
3295 /*
3296 * set the file creation context in a security record to the same as the
3297 * objective context of the specified inode
3298 */
3299 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3300 {
3301 struct inode_security_struct *isec = inode->i_security;
3302 struct task_security_struct *tsec = new->security;
3303 u32 sid = current_sid();
3304 int ret;
3305
3306 ret = avc_has_perm(sid, isec->sid,
3307 SECCLASS_KERNEL_SERVICE,
3308 KERNEL_SERVICE__CREATE_FILES_AS,
3309 NULL);
3310
3311 if (ret == 0)
3312 tsec->create_sid = isec->sid;
3313 return ret;
3314 }
3315
3316 static int selinux_kernel_module_request(char *kmod_name)
3317 {
3318 u32 sid;
3319 struct common_audit_data ad;
3320
3321 sid = task_sid(current);
3322
3323 COMMON_AUDIT_DATA_INIT(&ad, KMOD);
3324 ad.u.kmod_name = kmod_name;
3325
3326 return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
3327 SYSTEM__MODULE_REQUEST, &ad);
3328 }
3329
3330 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3331 {
3332 return current_has_perm(p, PROCESS__SETPGID);
3333 }
3334
3335 static int selinux_task_getpgid(struct task_struct *p)
3336 {
3337 return current_has_perm(p, PROCESS__GETPGID);
3338 }
3339
3340 static int selinux_task_getsid(struct task_struct *p)
3341 {
3342 return current_has_perm(p, PROCESS__GETSESSION);
3343 }
3344
3345 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3346 {
3347 *secid = task_sid(p);
3348 }
3349
3350 static int selinux_task_setnice(struct task_struct *p, int nice)
3351 {
3352 int rc;
3353
3354 rc = cap_task_setnice(p, nice);
3355 if (rc)
3356 return rc;
3357
3358 return current_has_perm(p, PROCESS__SETSCHED);
3359 }
3360
3361 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3362 {
3363 int rc;
3364
3365 rc = cap_task_setioprio(p, ioprio);
3366 if (rc)
3367 return rc;
3368
3369 return current_has_perm(p, PROCESS__SETSCHED);
3370 }
3371
3372 static int selinux_task_getioprio(struct task_struct *p)
3373 {
3374 return current_has_perm(p, PROCESS__GETSCHED);
3375 }
3376
3377 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
3378 struct rlimit *new_rlim)
3379 {
3380 struct rlimit *old_rlim = p->signal->rlim + resource;
3381
3382 /* Control the ability to change the hard limit (whether
3383 lowering or raising it), so that the hard limit can
3384 later be used as a safe reset point for the soft limit
3385 upon context transitions. See selinux_bprm_committing_creds. */
3386 if (old_rlim->rlim_max != new_rlim->rlim_max)
3387 return current_has_perm(p, PROCESS__SETRLIMIT);
3388
3389 return 0;
3390 }
3391
3392 static int selinux_task_setscheduler(struct task_struct *p)
3393 {
3394 int rc;
3395
3396 rc = cap_task_setscheduler(p);
3397 if (rc)
3398 return rc;
3399
3400 return current_has_perm(p, PROCESS__SETSCHED);
3401 }
3402
3403 static int selinux_task_getscheduler(struct task_struct *p)
3404 {
3405 return current_has_perm(p, PROCESS__GETSCHED);
3406 }
3407
3408 static int selinux_task_movememory(struct task_struct *p)
3409 {
3410 return current_has_perm(p, PROCESS__SETSCHED);
3411 }
3412
3413 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3414 int sig, u32 secid)
3415 {
3416 u32 perm;
3417 int rc;
3418
3419 if (!sig)
3420 perm = PROCESS__SIGNULL; /* null signal; existence test */
3421 else
3422 perm = signal_to_av(sig);
3423 if (secid)
3424 rc = avc_has_perm(secid, task_sid(p),
3425 SECCLASS_PROCESS, perm, NULL);
3426 else
3427 rc = current_has_perm(p, perm);
3428 return rc;
3429 }
3430
3431 static int selinux_task_wait(struct task_struct *p)
3432 {
3433 return task_has_perm(p, current, PROCESS__SIGCHLD);
3434 }
3435
3436 static void selinux_task_to_inode(struct task_struct *p,
3437 struct inode *inode)
3438 {
3439 struct inode_security_struct *isec = inode->i_security;
3440 u32 sid = task_sid(p);
3441
3442 isec->sid = sid;
3443 isec->initialized = 1;
3444 }
3445
3446 /* Returns error only if unable to parse addresses */
3447 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3448 struct common_audit_data *ad, u8 *proto)
3449 {
3450 int offset, ihlen, ret = -EINVAL;
3451 struct iphdr _iph, *ih;
3452
3453 offset = skb_network_offset(skb);
3454 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3455 if (ih == NULL)
3456 goto out;
3457
3458 ihlen = ih->ihl * 4;
3459 if (ihlen < sizeof(_iph))
3460 goto out;
3461
3462 ad->u.net.v4info.saddr = ih->saddr;
3463 ad->u.net.v4info.daddr = ih->daddr;
3464 ret = 0;
3465
3466 if (proto)
3467 *proto = ih->protocol;
3468
3469 switch (ih->protocol) {
3470 case IPPROTO_TCP: {
3471 struct tcphdr _tcph, *th;
3472
3473 if (ntohs(ih->frag_off) & IP_OFFSET)
3474 break;
3475
3476 offset += ihlen;
3477 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3478 if (th == NULL)
3479 break;
3480
3481 ad->u.net.sport = th->source;
3482 ad->u.net.dport = th->dest;
3483 break;
3484 }
3485
3486 case IPPROTO_UDP: {
3487 struct udphdr _udph, *uh;
3488
3489 if (ntohs(ih->frag_off) & IP_OFFSET)
3490 break;
3491
3492 offset += ihlen;
3493 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3494 if (uh == NULL)
3495 break;
3496
3497 ad->u.net.sport = uh->source;
3498 ad->u.net.dport = uh->dest;
3499 break;
3500 }
3501
3502 case IPPROTO_DCCP: {
3503 struct dccp_hdr _dccph, *dh;
3504
3505 if (ntohs(ih->frag_off) & IP_OFFSET)
3506 break;
3507
3508 offset += ihlen;
3509 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3510 if (dh == NULL)
3511 break;
3512
3513 ad->u.net.sport = dh->dccph_sport;
3514 ad->u.net.dport = dh->dccph_dport;
3515 break;
3516 }
3517
3518 default:
3519 break;
3520 }
3521 out:
3522 return ret;
3523 }
3524
3525 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3526
3527 /* Returns error only if unable to parse addresses */
3528 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3529 struct common_audit_data *ad, u8 *proto)
3530 {
3531 u8 nexthdr;
3532 int ret = -EINVAL, offset;
3533 struct ipv6hdr _ipv6h, *ip6;
3534
3535 offset = skb_network_offset(skb);
3536 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3537 if (ip6 == NULL)
3538 goto out;
3539
3540 ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr);
3541 ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr);
3542 ret = 0;
3543
3544 nexthdr = ip6->nexthdr;
3545 offset += sizeof(_ipv6h);
3546 offset = ipv6_skip_exthdr(skb, offset, &nexthdr);
3547 if (offset < 0)
3548 goto out;
3549
3550 if (proto)
3551 *proto = nexthdr;
3552
3553 switch (nexthdr) {
3554 case IPPROTO_TCP: {
3555 struct tcphdr _tcph, *th;
3556
3557 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3558 if (th == NULL)
3559 break;
3560
3561 ad->u.net.sport = th->source;
3562 ad->u.net.dport = th->dest;
3563 break;
3564 }
3565
3566 case IPPROTO_UDP: {
3567 struct udphdr _udph, *uh;
3568
3569 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3570 if (uh == NULL)
3571 break;
3572
3573 ad->u.net.sport = uh->source;
3574 ad->u.net.dport = uh->dest;
3575 break;
3576 }
3577
3578 case IPPROTO_DCCP: {
3579 struct dccp_hdr _dccph, *dh;
3580
3581 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3582 if (dh == NULL)
3583 break;
3584
3585 ad->u.net.sport = dh->dccph_sport;
3586 ad->u.net.dport = dh->dccph_dport;
3587 break;
3588 }
3589
3590 /* includes fragments */
3591 default:
3592 break;
3593 }
3594 out:
3595 return ret;
3596 }
3597
3598 #endif /* IPV6 */
3599
3600 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3601 char **_addrp, int src, u8 *proto)
3602 {
3603 char *addrp;
3604 int ret;
3605
3606 switch (ad->u.net.family) {
3607 case PF_INET:
3608 ret = selinux_parse_skb_ipv4(skb, ad, proto);
3609 if (ret)
3610 goto parse_error;
3611 addrp = (char *)(src ? &ad->u.net.v4info.saddr :
3612 &ad->u.net.v4info.daddr);
3613 goto okay;
3614
3615 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3616 case PF_INET6:
3617 ret = selinux_parse_skb_ipv6(skb, ad, proto);
3618 if (ret)
3619 goto parse_error;
3620 addrp = (char *)(src ? &ad->u.net.v6info.saddr :
3621 &ad->u.net.v6info.daddr);
3622 goto okay;
3623 #endif /* IPV6 */
3624 default:
3625 addrp = NULL;
3626 goto okay;
3627 }
3628
3629 parse_error:
3630 printk(KERN_WARNING
3631 "SELinux: failure in selinux_parse_skb(),"
3632 " unable to parse packet\n");
3633 return ret;
3634
3635 okay:
3636 if (_addrp)
3637 *_addrp = addrp;
3638 return 0;
3639 }
3640
3641 /**
3642 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3643 * @skb: the packet
3644 * @family: protocol family
3645 * @sid: the packet's peer label SID
3646 *
3647 * Description:
3648 * Check the various different forms of network peer labeling and determine
3649 * the peer label/SID for the packet; most of the magic actually occurs in
3650 * the security server function security_net_peersid_cmp(). The function
3651 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
3652 * or -EACCES if @sid is invalid due to inconsistencies with the different
3653 * peer labels.
3654 *
3655 */
3656 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3657 {
3658 int err;
3659 u32 xfrm_sid;
3660 u32 nlbl_sid;
3661 u32 nlbl_type;
3662
3663 selinux_skb_xfrm_sid(skb, &xfrm_sid);
3664 selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3665
3666 err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
3667 if (unlikely(err)) {
3668 printk(KERN_WARNING
3669 "SELinux: failure in selinux_skb_peerlbl_sid(),"
3670 " unable to determine packet's peer label\n");
3671 return -EACCES;
3672 }
3673
3674 return 0;
3675 }
3676
3677 /* socket security operations */
3678
3679 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
3680 u16 secclass, u32 *socksid)
3681 {
3682 if (tsec->sockcreate_sid > SECSID_NULL) {
3683 *socksid = tsec->sockcreate_sid;
3684 return 0;
3685 }
3686
3687 return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
3688 socksid);
3689 }
3690
3691 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
3692 {
3693 struct sk_security_struct *sksec = sk->sk_security;
3694 struct common_audit_data ad;
3695 u32 tsid = task_sid(task);
3696
3697 if (sksec->sid == SECINITSID_KERNEL)
3698 return 0;
3699
3700 COMMON_AUDIT_DATA_INIT(&ad, NET);
3701 ad.u.net.sk = sk;
3702
3703 return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
3704 }
3705
3706 static int selinux_socket_create(int family, int type,
3707 int protocol, int kern)
3708 {
3709 const struct task_security_struct *tsec = current_security();
3710 u32 newsid;
3711 u16 secclass;
3712 int rc;
3713
3714 if (kern)
3715 return 0;
3716
3717 secclass = socket_type_to_security_class(family, type, protocol);
3718 rc = socket_sockcreate_sid(tsec, secclass, &newsid);
3719 if (rc)
3720 return rc;
3721
3722 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
3723 }
3724
3725 static int selinux_socket_post_create(struct socket *sock, int family,
3726 int type, int protocol, int kern)
3727 {
3728 const struct task_security_struct *tsec = current_security();
3729 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
3730 struct sk_security_struct *sksec;
3731 int err = 0;
3732
3733 isec->sclass = socket_type_to_security_class(family, type, protocol);
3734
3735 if (kern)
3736 isec->sid = SECINITSID_KERNEL;
3737 else {
3738 err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
3739 if (err)
3740 return err;
3741 }
3742
3743 isec->initialized = 1;
3744
3745 if (sock->sk) {
3746 sksec = sock->sk->sk_security;
3747 sksec->sid = isec->sid;
3748 sksec->sclass = isec->sclass;
3749 err = selinux_netlbl_socket_post_create(sock->sk, family);
3750 }
3751
3752 return err;
3753 }
3754
3755 /* Range of port numbers used to automatically bind.
3756 Need to determine whether we should perform a name_bind
3757 permission check between the socket and the port number. */
3758
3759 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
3760 {
3761 struct sock *sk = sock->sk;
3762 u16 family;
3763 int err;
3764
3765 err = sock_has_perm(current, sk, SOCKET__BIND);
3766 if (err)
3767 goto out;
3768
3769 /*
3770 * If PF_INET or PF_INET6, check name_bind permission for the port.
3771 * Multiple address binding for SCTP is not supported yet: we just
3772 * check the first address now.
3773 */
3774 family = sk->sk_family;
3775 if (family == PF_INET || family == PF_INET6) {
3776 char *addrp;
3777 struct sk_security_struct *sksec = sk->sk_security;
3778 struct common_audit_data ad;
3779 struct sockaddr_in *addr4 = NULL;
3780 struct sockaddr_in6 *addr6 = NULL;
3781 unsigned short snum;
3782 u32 sid, node_perm;
3783
3784 if (family == PF_INET) {
3785 addr4 = (struct sockaddr_in *)address;
3786 snum = ntohs(addr4->sin_port);
3787 addrp = (char *)&addr4->sin_addr.s_addr;
3788 } else {
3789 addr6 = (struct sockaddr_in6 *)address;
3790 snum = ntohs(addr6->sin6_port);
3791 addrp = (char *)&addr6->sin6_addr.s6_addr;
3792 }
3793
3794 if (snum) {
3795 int low, high;
3796
3797 inet_get_local_port_range(&low, &high);
3798
3799 if (snum < max(PROT_SOCK, low) || snum > high) {
3800 err = sel_netport_sid(sk->sk_protocol,
3801 snum, &sid);
3802 if (err)
3803 goto out;
3804 COMMON_AUDIT_DATA_INIT(&ad, NET);
3805 ad.u.net.sport = htons(snum);
3806 ad.u.net.family = family;
3807 err = avc_has_perm(sksec->sid, sid,
3808 sksec->sclass,
3809 SOCKET__NAME_BIND, &ad);
3810 if (err)
3811 goto out;
3812 }
3813 }
3814
3815 switch (sksec->sclass) {
3816 case SECCLASS_TCP_SOCKET:
3817 node_perm = TCP_SOCKET__NODE_BIND;
3818 break;
3819
3820 case SECCLASS_UDP_SOCKET:
3821 node_perm = UDP_SOCKET__NODE_BIND;
3822 break;
3823
3824 case SECCLASS_DCCP_SOCKET:
3825 node_perm = DCCP_SOCKET__NODE_BIND;
3826 break;
3827
3828 default:
3829 node_perm = RAWIP_SOCKET__NODE_BIND;
3830 break;
3831 }
3832
3833 err = sel_netnode_sid(addrp, family, &sid);
3834 if (err)
3835 goto out;
3836
3837 COMMON_AUDIT_DATA_INIT(&ad, NET);
3838 ad.u.net.sport = htons(snum);
3839 ad.u.net.family = family;
3840
3841 if (family == PF_INET)
3842 ad.u.net.v4info.saddr = addr4->sin_addr.s_addr;
3843 else
3844 ipv6_addr_copy(&ad.u.net.v6info.saddr, &addr6->sin6_addr);
3845
3846 err = avc_has_perm(sksec->sid, sid,
3847 sksec->sclass, node_perm, &ad);
3848 if (err)
3849 goto out;
3850 }
3851 out:
3852 return err;
3853 }
3854
3855 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
3856 {
3857 struct sock *sk = sock->sk;
3858 struct sk_security_struct *sksec = sk->sk_security;
3859 int err;
3860
3861 err = sock_has_perm(current, sk, SOCKET__CONNECT);
3862 if (err)
3863 return err;
3864
3865 /*
3866 * If a TCP or DCCP socket, check name_connect permission for the port.
3867 */
3868 if (sksec->sclass == SECCLASS_TCP_SOCKET ||
3869 sksec->sclass == SECCLASS_DCCP_SOCKET) {
3870 struct common_audit_data ad;
3871 struct sockaddr_in *addr4 = NULL;
3872 struct sockaddr_in6 *addr6 = NULL;
3873 unsigned short snum;
3874 u32 sid, perm;
3875
3876 if (sk->sk_family == PF_INET) {
3877 addr4 = (struct sockaddr_in *)address;
3878 if (addrlen < sizeof(struct sockaddr_in))
3879 return -EINVAL;
3880 snum = ntohs(addr4->sin_port);
3881 } else {
3882 addr6 = (struct sockaddr_in6 *)address;
3883 if (addrlen < SIN6_LEN_RFC2133)
3884 return -EINVAL;
3885 snum = ntohs(addr6->sin6_port);
3886 }
3887
3888 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
3889 if (err)
3890 goto out;
3891
3892 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
3893 TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
3894
3895 COMMON_AUDIT_DATA_INIT(&ad, NET);
3896 ad.u.net.dport = htons(snum);
3897 ad.u.net.family = sk->sk_family;
3898 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
3899 if (err)
3900 goto out;
3901 }
3902
3903 err = selinux_netlbl_socket_connect(sk, address);
3904
3905 out:
3906 return err;
3907 }
3908
3909 static int selinux_socket_listen(struct socket *sock, int backlog)
3910 {
3911 return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
3912 }
3913
3914 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
3915 {
3916 int err;
3917 struct inode_security_struct *isec;
3918 struct inode_security_struct *newisec;
3919
3920 err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
3921 if (err)
3922 return err;
3923
3924 newisec = SOCK_INODE(newsock)->i_security;
3925
3926 isec = SOCK_INODE(sock)->i_security;
3927 newisec->sclass = isec->sclass;
3928 newisec->sid = isec->sid;
3929 newisec->initialized = 1;
3930
3931 return 0;
3932 }
3933
3934 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3935 int size)
3936 {
3937 return sock_has_perm(current, sock->sk, SOCKET__WRITE);
3938 }
3939
3940 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
3941 int size, int flags)
3942 {
3943 return sock_has_perm(current, sock->sk, SOCKET__READ);
3944 }
3945
3946 static int selinux_socket_getsockname(struct socket *sock)
3947 {
3948 return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
3949 }
3950
3951 static int selinux_socket_getpeername(struct socket *sock)
3952 {
3953 return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
3954 }
3955
3956 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
3957 {
3958 int err;
3959
3960 err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
3961 if (err)
3962 return err;
3963
3964 return selinux_netlbl_socket_setsockopt(sock, level, optname);
3965 }
3966
3967 static int selinux_socket_getsockopt(struct socket *sock, int level,
3968 int optname)
3969 {
3970 return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
3971 }
3972
3973 static int selinux_socket_shutdown(struct socket *sock, int how)
3974 {
3975 return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
3976 }
3977
3978 static int selinux_socket_unix_stream_connect(struct sock *sock,
3979 struct sock *other,
3980 struct sock *newsk)
3981 {
3982 struct sk_security_struct *sksec_sock = sock->sk_security;
3983 struct sk_security_struct *sksec_other = other->sk_security;
3984 struct sk_security_struct *sksec_new = newsk->sk_security;
3985 struct common_audit_data ad;
3986 int err;
3987
3988 COMMON_AUDIT_DATA_INIT(&ad, NET);
3989 ad.u.net.sk = other;
3990
3991 err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
3992 sksec_other->sclass,
3993 UNIX_STREAM_SOCKET__CONNECTTO, &ad);
3994 if (err)
3995 return err;
3996
3997 /* server child socket */
3998 sksec_new->peer_sid = sksec_sock->sid;
3999 err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
4000 &sksec_new->sid);
4001 if (err)
4002 return err;
4003
4004 /* connecting socket */
4005 sksec_sock->peer_sid = sksec_new->sid;
4006
4007 return 0;
4008 }
4009
4010 static int selinux_socket_unix_may_send(struct socket *sock,
4011 struct socket *other)
4012 {
4013 struct sk_security_struct *ssec = sock->sk->sk_security;
4014 struct sk_security_struct *osec = other->sk->sk_security;
4015 struct common_audit_data ad;
4016
4017 COMMON_AUDIT_DATA_INIT(&ad, NET);
4018 ad.u.net.sk = other->sk;
4019
4020 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
4021 &ad);
4022 }
4023
4024 static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
4025 u32 peer_sid,
4026 struct common_audit_data *ad)
4027 {
4028 int err;
4029 u32 if_sid;
4030 u32 node_sid;
4031
4032 err = sel_netif_sid(ifindex, &if_sid);
4033 if (err)
4034 return err;
4035 err = avc_has_perm(peer_sid, if_sid,
4036 SECCLASS_NETIF, NETIF__INGRESS, ad);
4037 if (err)
4038 return err;
4039
4040 err = sel_netnode_sid(addrp, family, &node_sid);
4041 if (err)
4042 return err;
4043 return avc_has_perm(peer_sid, node_sid,
4044 SECCLASS_NODE, NODE__RECVFROM, ad);
4045 }
4046
4047 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4048 u16 family)
4049 {
4050 int err = 0;
4051 struct sk_security_struct *sksec = sk->sk_security;
4052 u32 sk_sid = sksec->sid;
4053 struct common_audit_data ad;
4054 char *addrp;
4055
4056 COMMON_AUDIT_DATA_INIT(&ad, NET);
4057 ad.u.net.netif = skb->skb_iif;
4058 ad.u.net.family = family;
4059 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4060 if (err)
4061 return err;
4062
4063 if (selinux_secmark_enabled()) {
4064 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4065 PACKET__RECV, &ad);
4066 if (err)
4067 return err;
4068 }
4069
4070 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4071 if (err)
4072 return err;
4073 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4074
4075 return err;
4076 }
4077
4078 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4079 {
4080 int err;
4081 struct sk_security_struct *sksec = sk->sk_security;
4082 u16 family = sk->sk_family;
4083 u32 sk_sid = sksec->sid;
4084 struct common_audit_data ad;
4085 char *addrp;
4086 u8 secmark_active;
4087 u8 peerlbl_active;
4088
4089 if (family != PF_INET && family != PF_INET6)
4090 return 0;
4091
4092 /* Handle mapped IPv4 packets arriving via IPv6 sockets */
4093 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4094 family = PF_INET;
4095
4096 /* If any sort of compatibility mode is enabled then handoff processing
4097 * to the selinux_sock_rcv_skb_compat() function to deal with the
4098 * special handling. We do this in an attempt to keep this function
4099 * as fast and as clean as possible. */
4100 if (!selinux_policycap_netpeer)
4101 return selinux_sock_rcv_skb_compat(sk, skb, family);
4102
4103 secmark_active = selinux_secmark_enabled();
4104 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4105 if (!secmark_active && !peerlbl_active)
4106 return 0;
4107
4108 COMMON_AUDIT_DATA_INIT(&ad, NET);
4109 ad.u.net.netif = skb->skb_iif;
4110 ad.u.net.family = family;
4111 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4112 if (err)
4113 return err;
4114
4115 if (peerlbl_active) {
4116 u32 peer_sid;
4117
4118 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4119 if (err)
4120 return err;
4121 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
4122 peer_sid, &ad);
4123 if (err) {
4124 selinux_netlbl_err(skb, err, 0);
4125 return err;
4126 }
4127 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4128 PEER__RECV, &ad);
4129 if (err)
4130 selinux_netlbl_err(skb, err, 0);
4131 }
4132
4133 if (secmark_active) {
4134 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4135 PACKET__RECV, &ad);
4136 if (err)
4137 return err;
4138 }
4139
4140 return err;
4141 }
4142
4143 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4144 int __user *optlen, unsigned len)
4145 {
4146 int err = 0;
4147 char *scontext;
4148 u32 scontext_len;
4149 struct sk_security_struct *sksec = sock->sk->sk_security;
4150 u32 peer_sid = SECSID_NULL;
4151
4152 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4153 sksec->sclass == SECCLASS_TCP_SOCKET)
4154 peer_sid = sksec->peer_sid;
4155 if (peer_sid == SECSID_NULL)
4156 return -ENOPROTOOPT;
4157
4158 err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4159 if (err)
4160 return err;
4161
4162 if (scontext_len > len) {
4163 err = -ERANGE;
4164 goto out_len;
4165 }
4166
4167 if (copy_to_user(optval, scontext, scontext_len))
4168 err = -EFAULT;
4169
4170 out_len:
4171 if (put_user(scontext_len, optlen))
4172 err = -EFAULT;
4173 kfree(scontext);
4174 return err;
4175 }
4176
4177 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4178 {
4179 u32 peer_secid = SECSID_NULL;
4180 u16 family;
4181
4182 if (skb && skb->protocol == htons(ETH_P_IP))
4183 family = PF_INET;
4184 else if (skb && skb->protocol == htons(ETH_P_IPV6))
4185 family = PF_INET6;
4186 else if (sock)
4187 family = sock->sk->sk_family;
4188 else
4189 goto out;
4190
4191 if (sock && family == PF_UNIX)
4192 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4193 else if (skb)
4194 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4195
4196 out:
4197 *secid = peer_secid;
4198 if (peer_secid == SECSID_NULL)
4199 return -EINVAL;
4200 return 0;
4201 }
4202
4203 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4204 {
4205 struct sk_security_struct *sksec;
4206
4207 sksec = kzalloc(sizeof(*sksec), priority);
4208 if (!sksec)
4209 return -ENOMEM;
4210
4211 sksec->peer_sid = SECINITSID_UNLABELED;
4212 sksec->sid = SECINITSID_UNLABELED;
4213 selinux_netlbl_sk_security_reset(sksec);
4214 sk->sk_security = sksec;
4215
4216 return 0;
4217 }
4218
4219 static void selinux_sk_free_security(struct sock *sk)
4220 {
4221 struct sk_security_struct *sksec = sk->sk_security;
4222
4223 sk->sk_security = NULL;
4224 selinux_netlbl_sk_security_free(sksec);
4225 kfree(sksec);
4226 }
4227
4228 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4229 {
4230 struct sk_security_struct *sksec = sk->sk_security;
4231 struct sk_security_struct *newsksec = newsk->sk_security;
4232
4233 newsksec->sid = sksec->sid;
4234 newsksec->peer_sid = sksec->peer_sid;
4235 newsksec->sclass = sksec->sclass;
4236
4237 selinux_netlbl_sk_security_reset(newsksec);
4238 }
4239
4240 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4241 {
4242 if (!sk)
4243 *secid = SECINITSID_ANY_SOCKET;
4244 else {
4245 struct sk_security_struct *sksec = sk->sk_security;
4246
4247 *secid = sksec->sid;
4248 }
4249 }
4250
4251 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4252 {
4253 struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
4254 struct sk_security_struct *sksec = sk->sk_security;
4255
4256 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4257 sk->sk_family == PF_UNIX)
4258 isec->sid = sksec->sid;
4259 sksec->sclass = isec->sclass;
4260 }
4261
4262 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4263 struct request_sock *req)
4264 {
4265 struct sk_security_struct *sksec = sk->sk_security;
4266 int err;
4267 u16 family = sk->sk_family;
4268 u32 newsid;
4269 u32 peersid;
4270
4271 /* handle mapped IPv4 packets arriving via IPv6 sockets */
4272 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4273 family = PF_INET;
4274
4275 err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4276 if (err)
4277 return err;
4278 if (peersid == SECSID_NULL) {
4279 req->secid = sksec->sid;
4280 req->peer_secid = SECSID_NULL;
4281 } else {
4282 err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
4283 if (err)
4284 return err;
4285 req->secid = newsid;
4286 req->peer_secid = peersid;
4287 }
4288
4289 return selinux_netlbl_inet_conn_request(req, family);
4290 }
4291
4292 static void selinux_inet_csk_clone(struct sock *newsk,
4293 const struct request_sock *req)
4294 {
4295 struct sk_security_struct *newsksec = newsk->sk_security;
4296
4297 newsksec->sid = req->secid;
4298 newsksec->peer_sid = req->peer_secid;
4299 /* NOTE: Ideally, we should also get the isec->sid for the
4300 new socket in sync, but we don't have the isec available yet.
4301 So we will wait until sock_graft to do it, by which
4302 time it will have been created and available. */
4303
4304 /* We don't need to take any sort of lock here as we are the only
4305 * thread with access to newsksec */
4306 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4307 }
4308
4309 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4310 {
4311 u16 family = sk->sk_family;
4312 struct sk_security_struct *sksec = sk->sk_security;
4313
4314 /* handle mapped IPv4 packets arriving via IPv6 sockets */
4315 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4316 family = PF_INET;
4317
4318 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4319 }
4320
4321 static int selinux_secmark_relabel_packet(u32 sid)
4322 {
4323 const struct task_security_struct *__tsec;
4324 u32 tsid;
4325
4326 __tsec = current_security();
4327 tsid = __tsec->sid;
4328
4329 return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
4330 }
4331
4332 static void selinux_secmark_refcount_inc(void)
4333 {
4334 atomic_inc(&selinux_secmark_refcount);
4335 }
4336
4337 static void selinux_secmark_refcount_dec(void)
4338 {
4339 atomic_dec(&selinux_secmark_refcount);
4340 }
4341
4342 static void selinux_req_classify_flow(const struct request_sock *req,
4343 struct flowi *fl)
4344 {
4345 fl->secid = req->secid;
4346 }
4347
4348 static int selinux_tun_dev_create(void)
4349 {
4350 u32 sid = current_sid();
4351
4352 /* we aren't taking into account the "sockcreate" SID since the socket
4353 * that is being created here is not a socket in the traditional sense,
4354 * instead it is a private sock, accessible only to the kernel, and
4355 * representing a wide range of network traffic spanning multiple
4356 * connections unlike traditional sockets - check the TUN driver to
4357 * get a better understanding of why this socket is special */
4358
4359 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4360 NULL);
4361 }
4362
4363 static void selinux_tun_dev_post_create(struct sock *sk)
4364 {
4365 struct sk_security_struct *sksec = sk->sk_security;
4366
4367 /* we don't currently perform any NetLabel based labeling here and it
4368 * isn't clear that we would want to do so anyway; while we could apply
4369 * labeling without the support of the TUN user the resulting labeled
4370 * traffic from the other end of the connection would almost certainly
4371 * cause confusion to the TUN user that had no idea network labeling
4372 * protocols were being used */
4373
4374 /* see the comments in selinux_tun_dev_create() about why we don't use
4375 * the sockcreate SID here */
4376
4377 sksec->sid = current_sid();
4378 sksec->sclass = SECCLASS_TUN_SOCKET;
4379 }
4380
4381 static int selinux_tun_dev_attach(struct sock *sk)
4382 {
4383 struct sk_security_struct *sksec = sk->sk_security;
4384 u32 sid = current_sid();
4385 int err;
4386
4387 err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET,
4388 TUN_SOCKET__RELABELFROM, NULL);
4389 if (err)
4390 return err;
4391 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4392 TUN_SOCKET__RELABELTO, NULL);
4393 if (err)
4394 return err;
4395
4396 sksec->sid = sid;
4397
4398 return 0;
4399 }
4400
4401 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4402 {
4403 int err = 0;
4404 u32 perm;
4405 struct nlmsghdr *nlh;
4406 struct sk_security_struct *sksec = sk->sk_security;
4407
4408 if (skb->len < NLMSG_SPACE(0)) {
4409 err = -EINVAL;
4410 goto out;
4411 }
4412 nlh = nlmsg_hdr(skb);
4413
4414 err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
4415 if (err) {
4416 if (err == -EINVAL) {
4417 audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
4418 "SELinux: unrecognized netlink message"
4419 " type=%hu for sclass=%hu\n",
4420 nlh->nlmsg_type, sksec->sclass);
4421 if (!selinux_enforcing || security_get_allow_unknown())
4422 err = 0;
4423 }
4424
4425 /* Ignore */
4426 if (err == -ENOENT)
4427 err = 0;
4428 goto out;
4429 }
4430
4431 err = sock_has_perm(current, sk, perm);
4432 out:
4433 return err;
4434 }
4435
4436 #ifdef CONFIG_NETFILTER
4437
4438 static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
4439 u16 family)
4440 {
4441 int err;
4442 char *addrp;
4443 u32 peer_sid;
4444 struct common_audit_data ad;
4445 u8 secmark_active;
4446 u8 netlbl_active;
4447 u8 peerlbl_active;
4448
4449 if (!selinux_policycap_netpeer)
4450 return NF_ACCEPT;
4451
4452 secmark_active = selinux_secmark_enabled();
4453 netlbl_active = netlbl_enabled();
4454 peerlbl_active = netlbl_active || selinux_xfrm_enabled();
4455 if (!secmark_active && !peerlbl_active)
4456 return NF_ACCEPT;
4457
4458 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
4459 return NF_DROP;
4460
4461 COMMON_AUDIT_DATA_INIT(&ad, NET);
4462 ad.u.net.netif = ifindex;
4463 ad.u.net.family = family;
4464 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
4465 return NF_DROP;
4466
4467 if (peerlbl_active) {
4468 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
4469 peer_sid, &ad);
4470 if (err) {
4471 selinux_netlbl_err(skb, err, 1);
4472 return NF_DROP;
4473 }
4474 }
4475
4476 if (secmark_active)
4477 if (avc_has_perm(peer_sid, skb->secmark,
4478 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
4479 return NF_DROP;
4480
4481 if (netlbl_active)
4482 /* we do this in the FORWARD path and not the POST_ROUTING
4483 * path because we want to make sure we apply the necessary
4484 * labeling before IPsec is applied so we can leverage AH
4485 * protection */
4486 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
4487 return NF_DROP;
4488
4489 return NF_ACCEPT;
4490 }
4491
4492 static unsigned int selinux_ipv4_forward(unsigned int hooknum,
4493 struct sk_buff *skb,
4494 const struct net_device *in,
4495 const struct net_device *out,
4496 int (*okfn)(struct sk_buff *))
4497 {
4498 return selinux_ip_forward(skb, in->ifindex, PF_INET);
4499 }
4500
4501 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4502 static unsigned int selinux_ipv6_forward(unsigned int hooknum,
4503 struct sk_buff *skb,
4504 const struct net_device *in,
4505 const struct net_device *out,
4506 int (*okfn)(struct sk_buff *))
4507 {
4508 return selinux_ip_forward(skb, in->ifindex, PF_INET6);
4509 }
4510 #endif /* IPV6 */
4511
4512 static unsigned int selinux_ip_output(struct sk_buff *skb,
4513 u16 family)
4514 {
4515 u32 sid;
4516
4517 if (!netlbl_enabled())
4518 return NF_ACCEPT;
4519
4520 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
4521 * because we want to make sure we apply the necessary labeling
4522 * before IPsec is applied so we can leverage AH protection */
4523 if (skb->sk) {
4524 struct sk_security_struct *sksec = skb->sk->sk_security;
4525 sid = sksec->sid;
4526 } else
4527 sid = SECINITSID_KERNEL;
4528 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
4529 return NF_DROP;
4530
4531 return NF_ACCEPT;
4532 }
4533
4534 static unsigned int selinux_ipv4_output(unsigned int hooknum,
4535 struct sk_buff *skb,
4536 const struct net_device *in,
4537 const struct net_device *out,
4538 int (*okfn)(struct sk_buff *))
4539 {
4540 return selinux_ip_output(skb, PF_INET);
4541 }
4542
4543 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
4544 int ifindex,
4545 u16 family)
4546 {
4547 struct sock *sk = skb->sk;
4548 struct sk_security_struct *sksec;
4549 struct common_audit_data ad;
4550 char *addrp;
4551 u8 proto;
4552
4553 if (sk == NULL)
4554 return NF_ACCEPT;
4555 sksec = sk->sk_security;
4556
4557 COMMON_AUDIT_DATA_INIT(&ad, NET);
4558 ad.u.net.netif = ifindex;
4559 ad.u.net.family = family;
4560 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
4561 return NF_DROP;
4562
4563 if (selinux_secmark_enabled())
4564 if (avc_has_perm(sksec->sid, skb->secmark,
4565 SECCLASS_PACKET, PACKET__SEND, &ad))
4566 return NF_DROP_ERR(-ECONNREFUSED);
4567
4568 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
4569 return NF_DROP_ERR(-ECONNREFUSED);
4570
4571 return NF_ACCEPT;
4572 }
4573
4574 static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
4575 u16 family)
4576 {
4577 u32 secmark_perm;
4578 u32 peer_sid;
4579 struct sock *sk;
4580 struct common_audit_data ad;
4581 char *addrp;
4582 u8 secmark_active;
4583 u8 peerlbl_active;
4584
4585 /* If any sort of compatibility mode is enabled then handoff processing
4586 * to the selinux_ip_postroute_compat() function to deal with the
4587 * special handling. We do this in an attempt to keep this function
4588 * as fast and as clean as possible. */
4589 if (!selinux_policycap_netpeer)
4590 return selinux_ip_postroute_compat(skb, ifindex, family);
4591 #ifdef CONFIG_XFRM
4592 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
4593 * packet transformation so allow the packet to pass without any checks
4594 * since we'll have another chance to perform access control checks
4595 * when the packet is on it's final way out.
4596 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
4597 * is NULL, in this case go ahead and apply access control. */
4598 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
4599 return NF_ACCEPT;
4600 #endif
4601 secmark_active = selinux_secmark_enabled();
4602 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4603 if (!secmark_active && !peerlbl_active)
4604 return NF_ACCEPT;
4605
4606 /* if the packet is being forwarded then get the peer label from the
4607 * packet itself; otherwise check to see if it is from a local
4608 * application or the kernel, if from an application get the peer label
4609 * from the sending socket, otherwise use the kernel's sid */
4610 sk = skb->sk;
4611 if (sk == NULL) {
4612 if (skb->skb_iif) {
4613 secmark_perm = PACKET__FORWARD_OUT;
4614 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4615 return NF_DROP;
4616 } else {
4617 secmark_perm = PACKET__SEND;
4618 peer_sid = SECINITSID_KERNEL;
4619 }
4620 } else {
4621 struct sk_security_struct *sksec = sk->sk_security;
4622 peer_sid = sksec->sid;
4623 secmark_perm = PACKET__SEND;
4624 }
4625
4626 COMMON_AUDIT_DATA_INIT(&ad, NET);
4627 ad.u.net.netif = ifindex;
4628 ad.u.net.family = family;
4629 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4630 return NF_DROP;
4631
4632 if (secmark_active)
4633 if (avc_has_perm(peer_sid, skb->secmark,
4634 SECCLASS_PACKET, secmark_perm, &ad))
4635 return NF_DROP_ERR(-ECONNREFUSED);
4636
4637 if (peerlbl_active) {
4638 u32 if_sid;
4639 u32 node_sid;
4640
4641 if (sel_netif_sid(ifindex, &if_sid))
4642 return NF_DROP;
4643 if (avc_has_perm(peer_sid, if_sid,
4644 SECCLASS_NETIF, NETIF__EGRESS, &ad))
4645 return NF_DROP_ERR(-ECONNREFUSED);
4646
4647 if (sel_netnode_sid(addrp, family, &node_sid))
4648 return NF_DROP;
4649 if (avc_has_perm(peer_sid, node_sid,
4650 SECCLASS_NODE, NODE__SENDTO, &ad))
4651 return NF_DROP_ERR(-ECONNREFUSED);
4652 }
4653
4654 return NF_ACCEPT;
4655 }
4656
4657 static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
4658 struct sk_buff *skb,
4659 const struct net_device *in,
4660 const struct net_device *out,
4661 int (*okfn)(struct sk_buff *))
4662 {
4663 return selinux_ip_postroute(skb, out->ifindex, PF_INET);
4664 }
4665
4666 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4667 static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
4668 struct sk_buff *skb,
4669 const struct net_device *in,
4670 const struct net_device *out,
4671 int (*okfn)(struct sk_buff *))
4672 {
4673 return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
4674 }
4675 #endif /* IPV6 */
4676
4677 #endif /* CONFIG_NETFILTER */
4678
4679 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
4680 {
4681 int err;
4682
4683 err = cap_netlink_send(sk, skb);
4684 if (err)
4685 return err;
4686
4687 return selinux_nlmsg_perm(sk, skb);
4688 }
4689
4690 static int selinux_netlink_recv(struct sk_buff *skb, int capability)
4691 {
4692 int err;
4693 struct common_audit_data ad;
4694
4695 err = cap_netlink_recv(skb, capability);
4696 if (err)
4697 return err;
4698
4699 COMMON_AUDIT_DATA_INIT(&ad, CAP);
4700 ad.u.cap = capability;
4701
4702 return avc_has_perm(NETLINK_CB(skb).sid, NETLINK_CB(skb).sid,
4703 SECCLASS_CAPABILITY, CAP_TO_MASK(capability), &ad);
4704 }
4705
4706 static int ipc_alloc_security(struct task_struct *task,
4707 struct kern_ipc_perm *perm,
4708 u16 sclass)
4709 {
4710 struct ipc_security_struct *isec;
4711 u32 sid;
4712
4713 isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
4714 if (!isec)
4715 return -ENOMEM;
4716
4717 sid = task_sid(task);
4718 isec->sclass = sclass;
4719 isec->sid = sid;
4720 perm->security = isec;
4721
4722 return 0;
4723 }
4724
4725 static void ipc_free_security(struct kern_ipc_perm *perm)
4726 {
4727 struct ipc_security_struct *isec = perm->security;
4728 perm->security = NULL;
4729 kfree(isec);
4730 }
4731
4732 static int msg_msg_alloc_security(struct msg_msg *msg)
4733 {
4734 struct msg_security_struct *msec;
4735
4736 msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
4737 if (!msec)
4738 return -ENOMEM;
4739
4740 msec->sid = SECINITSID_UNLABELED;
4741 msg->security = msec;
4742
4743 return 0;
4744 }
4745
4746 static void msg_msg_free_security(struct msg_msg *msg)
4747 {
4748 struct msg_security_struct *msec = msg->security;
4749
4750 msg->security = NULL;
4751 kfree(msec);
4752 }
4753
4754 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
4755 u32 perms)
4756 {
4757 struct ipc_security_struct *isec;
4758 struct common_audit_data ad;
4759 u32 sid = current_sid();
4760
4761 isec = ipc_perms->security;
4762
4763 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4764 ad.u.ipc_id = ipc_perms->key;
4765
4766 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
4767 }
4768
4769 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
4770 {
4771 return msg_msg_alloc_security(msg);
4772 }
4773
4774 static void selinux_msg_msg_free_security(struct msg_msg *msg)
4775 {
4776 msg_msg_free_security(msg);
4777 }
4778
4779 /* message queue security operations */
4780 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
4781 {
4782 struct ipc_security_struct *isec;
4783 struct common_audit_data ad;
4784 u32 sid = current_sid();
4785 int rc;
4786
4787 rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
4788 if (rc)
4789 return rc;
4790
4791 isec = msq->q_perm.security;
4792
4793 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4794 ad.u.ipc_id = msq->q_perm.key;
4795
4796 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4797 MSGQ__CREATE, &ad);
4798 if (rc) {
4799 ipc_free_security(&msq->q_perm);
4800 return rc;
4801 }
4802 return 0;
4803 }
4804
4805 static void selinux_msg_queue_free_security(struct msg_queue *msq)
4806 {
4807 ipc_free_security(&msq->q_perm);
4808 }
4809
4810 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
4811 {
4812 struct ipc_security_struct *isec;
4813 struct common_audit_data ad;
4814 u32 sid = current_sid();
4815
4816 isec = msq->q_perm.security;
4817
4818 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4819 ad.u.ipc_id = msq->q_perm.key;
4820
4821 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4822 MSGQ__ASSOCIATE, &ad);
4823 }
4824
4825 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
4826 {
4827 int err;
4828 int perms;
4829
4830 switch (cmd) {
4831 case IPC_INFO:
4832 case MSG_INFO:
4833 /* No specific object, just general system-wide information. */
4834 return task_has_system(current, SYSTEM__IPC_INFO);
4835 case IPC_STAT:
4836 case MSG_STAT:
4837 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
4838 break;
4839 case IPC_SET:
4840 perms = MSGQ__SETATTR;
4841 break;
4842 case IPC_RMID:
4843 perms = MSGQ__DESTROY;
4844 break;
4845 default:
4846 return 0;
4847 }
4848
4849 err = ipc_has_perm(&msq->q_perm, perms);
4850 return err;
4851 }
4852
4853 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
4854 {
4855 struct ipc_security_struct *isec;
4856 struct msg_security_struct *msec;
4857 struct common_audit_data ad;
4858 u32 sid = current_sid();
4859 int rc;
4860
4861 isec = msq->q_perm.security;
4862 msec = msg->security;
4863
4864 /*
4865 * First time through, need to assign label to the message
4866 */
4867 if (msec->sid == SECINITSID_UNLABELED) {
4868 /*
4869 * Compute new sid based on current process and
4870 * message queue this message will be stored in
4871 */
4872 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
4873 NULL, &msec->sid);
4874 if (rc)
4875 return rc;
4876 }
4877
4878 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4879 ad.u.ipc_id = msq->q_perm.key;
4880
4881 /* Can this process write to the queue? */
4882 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4883 MSGQ__WRITE, &ad);
4884 if (!rc)
4885 /* Can this process send the message */
4886 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
4887 MSG__SEND, &ad);
4888 if (!rc)
4889 /* Can the message be put in the queue? */
4890 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
4891 MSGQ__ENQUEUE, &ad);
4892
4893 return rc;
4894 }
4895
4896 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
4897 struct task_struct *target,
4898 long type, int mode)
4899 {
4900 struct ipc_security_struct *isec;
4901 struct msg_security_struct *msec;
4902 struct common_audit_data ad;
4903 u32 sid = task_sid(target);
4904 int rc;
4905
4906 isec = msq->q_perm.security;
4907 msec = msg->security;
4908
4909 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4910 ad.u.ipc_id = msq->q_perm.key;
4911
4912 rc = avc_has_perm(sid, isec->sid,
4913 SECCLASS_MSGQ, MSGQ__READ, &ad);
4914 if (!rc)
4915 rc = avc_has_perm(sid, msec->sid,
4916 SECCLASS_MSG, MSG__RECEIVE, &ad);
4917 return rc;
4918 }
4919
4920 /* Shared Memory security operations */
4921 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
4922 {
4923 struct ipc_security_struct *isec;
4924 struct common_audit_data ad;
4925 u32 sid = current_sid();
4926 int rc;
4927
4928 rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
4929 if (rc)
4930 return rc;
4931
4932 isec = shp->shm_perm.security;
4933
4934 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4935 ad.u.ipc_id = shp->shm_perm.key;
4936
4937 rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
4938 SHM__CREATE, &ad);
4939 if (rc) {
4940 ipc_free_security(&shp->shm_perm);
4941 return rc;
4942 }
4943 return 0;
4944 }
4945
4946 static void selinux_shm_free_security(struct shmid_kernel *shp)
4947 {
4948 ipc_free_security(&shp->shm_perm);
4949 }
4950
4951 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
4952 {
4953 struct ipc_security_struct *isec;
4954 struct common_audit_data ad;
4955 u32 sid = current_sid();
4956
4957 isec = shp->shm_perm.security;
4958
4959 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4960 ad.u.ipc_id = shp->shm_perm.key;
4961
4962 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
4963 SHM__ASSOCIATE, &ad);
4964 }
4965
4966 /* Note, at this point, shp is locked down */
4967 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
4968 {
4969 int perms;
4970 int err;
4971
4972 switch (cmd) {
4973 case IPC_INFO:
4974 case SHM_INFO:
4975 /* No specific object, just general system-wide information. */
4976 return task_has_system(current, SYSTEM__IPC_INFO);
4977 case IPC_STAT:
4978 case SHM_STAT:
4979 perms = SHM__GETATTR | SHM__ASSOCIATE;
4980 break;
4981 case IPC_SET:
4982 perms = SHM__SETATTR;
4983 break;
4984 case SHM_LOCK:
4985 case SHM_UNLOCK:
4986 perms = SHM__LOCK;
4987 break;
4988 case IPC_RMID:
4989 perms = SHM__DESTROY;
4990 break;
4991 default:
4992 return 0;
4993 }
4994
4995 err = ipc_has_perm(&shp->shm_perm, perms);
4996 return err;
4997 }
4998
4999 static int selinux_shm_shmat(struct shmid_kernel *shp,
5000 char __user *shmaddr, int shmflg)
5001 {
5002 u32 perms;
5003
5004 if (shmflg & SHM_RDONLY)
5005 perms = SHM__READ;
5006 else
5007 perms = SHM__READ | SHM__WRITE;
5008
5009 return ipc_has_perm(&shp->shm_perm, perms);
5010 }
5011
5012 /* Semaphore security operations */
5013 static int selinux_sem_alloc_security(struct sem_array *sma)
5014 {
5015 struct ipc_security_struct *isec;
5016 struct common_audit_data ad;
5017 u32 sid = current_sid();
5018 int rc;
5019
5020 rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
5021 if (rc)
5022 return rc;
5023
5024 isec = sma->sem_perm.security;
5025
5026 COMMON_AUDIT_DATA_INIT(&ad, IPC);
5027 ad.u.ipc_id = sma->sem_perm.key;
5028
5029 rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5030 SEM__CREATE, &ad);
5031 if (rc) {
5032 ipc_free_security(&sma->sem_perm);
5033 return rc;
5034 }
5035 return 0;
5036 }
5037
5038 static void selinux_sem_free_security(struct sem_array *sma)
5039 {
5040 ipc_free_security(&sma->sem_perm);
5041 }
5042
5043 static int selinux_sem_associate(struct sem_array *sma, int semflg)
5044 {
5045 struct ipc_security_struct *isec;
5046 struct common_audit_data ad;
5047 u32 sid = current_sid();
5048
5049 isec = sma->sem_perm.security;
5050
5051 COMMON_AUDIT_DATA_INIT(&ad, IPC);
5052 ad.u.ipc_id = sma->sem_perm.key;
5053
5054 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5055 SEM__ASSOCIATE, &ad);
5056 }
5057
5058 /* Note, at this point, sma is locked down */
5059 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5060 {
5061 int err;
5062 u32 perms;
5063
5064 switch (cmd) {
5065 case IPC_INFO:
5066 case SEM_INFO:
5067 /* No specific object, just general system-wide information. */
5068 return task_has_system(current, SYSTEM__IPC_INFO);
5069 case GETPID:
5070 case GETNCNT:
5071 case GETZCNT:
5072 perms = SEM__GETATTR;
5073 break;
5074 case GETVAL:
5075 case GETALL:
5076 perms = SEM__READ;
5077 break;
5078 case SETVAL:
5079 case SETALL:
5080 perms = SEM__WRITE;
5081 break;
5082 case IPC_RMID:
5083 perms = SEM__DESTROY;
5084 break;
5085 case IPC_SET:
5086 perms = SEM__SETATTR;
5087 break;
5088 case IPC_STAT:
5089 case SEM_STAT:
5090 perms = SEM__GETATTR | SEM__ASSOCIATE;
5091 break;
5092 default:
5093 return 0;
5094 }
5095
5096 err = ipc_has_perm(&sma->sem_perm, perms);
5097 return err;
5098 }
5099
5100 static int selinux_sem_semop(struct sem_array *sma,
5101 struct sembuf *sops, unsigned nsops, int alter)
5102 {
5103 u32 perms;
5104
5105 if (alter)
5106 perms = SEM__READ | SEM__WRITE;
5107 else
5108 perms = SEM__READ;
5109
5110 return ipc_has_perm(&sma->sem_perm, perms);
5111 }
5112
5113 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5114 {
5115 u32 av = 0;
5116
5117 av = 0;
5118 if (flag & S_IRUGO)
5119 av |= IPC__UNIX_READ;
5120 if (flag & S_IWUGO)
5121 av |= IPC__UNIX_WRITE;
5122
5123 if (av == 0)
5124 return 0;
5125
5126 return ipc_has_perm(ipcp, av);
5127 }
5128
5129 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5130 {
5131 struct ipc_security_struct *isec = ipcp->security;
5132 *secid = isec->sid;
5133 }
5134
5135 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5136 {
5137 if (inode)
5138 inode_doinit_with_dentry(inode, dentry);
5139 }
5140
5141 static int selinux_getprocattr(struct task_struct *p,
5142 char *name, char **value)
5143 {
5144 const struct task_security_struct *__tsec;
5145 u32 sid;
5146 int error;
5147 unsigned len;
5148
5149 if (current != p) {
5150 error = current_has_perm(p, PROCESS__GETATTR);
5151 if (error)
5152 return error;
5153 }
5154
5155 rcu_read_lock();
5156 __tsec = __task_cred(p)->security;
5157
5158 if (!strcmp(name, "current"))
5159 sid = __tsec->sid;
5160 else if (!strcmp(name, "prev"))
5161 sid = __tsec->osid;
5162 else if (!strcmp(name, "exec"))
5163 sid = __tsec->exec_sid;
5164 else if (!strcmp(name, "fscreate"))
5165 sid = __tsec->create_sid;
5166 else if (!strcmp(name, "keycreate"))
5167 sid = __tsec->keycreate_sid;
5168 else if (!strcmp(name, "sockcreate"))
5169 sid = __tsec->sockcreate_sid;
5170 else
5171 goto invalid;
5172 rcu_read_unlock();
5173
5174 if (!sid)
5175 return 0;
5176
5177 error = security_sid_to_context(sid, value, &len);
5178 if (error)
5179 return error;
5180 return len;
5181
5182 invalid:
5183 rcu_read_unlock();
5184 return -EINVAL;
5185 }
5186
5187 static int selinux_setprocattr(struct task_struct *p,
5188 char *name, void *value, size_t size)
5189 {
5190 struct task_security_struct *tsec;
5191 struct task_struct *tracer;
5192 struct cred *new;
5193 u32 sid = 0, ptsid;
5194 int error;
5195 char *str = value;
5196
5197 if (current != p) {
5198 /* SELinux only allows a process to change its own
5199 security attributes. */
5200 return -EACCES;
5201 }
5202
5203 /*
5204 * Basic control over ability to set these attributes at all.
5205 * current == p, but we'll pass them separately in case the
5206 * above restriction is ever removed.
5207 */
5208 if (!strcmp(name, "exec"))
5209 error = current_has_perm(p, PROCESS__SETEXEC);
5210 else if (!strcmp(name, "fscreate"))
5211 error = current_has_perm(p, PROCESS__SETFSCREATE);
5212 else if (!strcmp(name, "keycreate"))
5213 error = current_has_perm(p, PROCESS__SETKEYCREATE);
5214 else if (!strcmp(name, "sockcreate"))
5215 error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5216 else if (!strcmp(name, "current"))
5217 error = current_has_perm(p, PROCESS__SETCURRENT);
5218 else
5219 error = -EINVAL;
5220 if (error)
5221 return error;
5222
5223 /* Obtain a SID for the context, if one was specified. */
5224 if (size && str[1] && str[1] != '\n') {
5225 if (str[size-1] == '\n') {
5226 str[size-1] = 0;
5227 size--;
5228 }
5229 error = security_context_to_sid(value, size, &sid);
5230 if (error == -EINVAL && !strcmp(name, "fscreate")) {
5231 if (!capable(CAP_MAC_ADMIN))
5232 return error;
5233 error = security_context_to_sid_force(value, size,
5234 &sid);
5235 }
5236 if (error)
5237 return error;
5238 }
5239
5240 new = prepare_creds();
5241 if (!new)
5242 return -ENOMEM;
5243
5244 /* Permission checking based on the specified context is
5245 performed during the actual operation (execve,
5246 open/mkdir/...), when we know the full context of the
5247 operation. See selinux_bprm_set_creds for the execve
5248 checks and may_create for the file creation checks. The
5249 operation will then fail if the context is not permitted. */
5250 tsec = new->security;
5251 if (!strcmp(name, "exec")) {
5252 tsec->exec_sid = sid;
5253 } else if (!strcmp(name, "fscreate")) {
5254 tsec->create_sid = sid;
5255 } else if (!strcmp(name, "keycreate")) {
5256 error = may_create_key(sid, p);
5257 if (error)
5258 goto abort_change;
5259 tsec->keycreate_sid = sid;
5260 } else if (!strcmp(name, "sockcreate")) {
5261 tsec->sockcreate_sid = sid;
5262 } else if (!strcmp(name, "current")) {
5263 error = -EINVAL;
5264 if (sid == 0)
5265 goto abort_change;
5266
5267 /* Only allow single threaded processes to change context */
5268 error = -EPERM;
5269 if (!current_is_single_threaded()) {
5270 error = security_bounded_transition(tsec->sid, sid);
5271 if (error)
5272 goto abort_change;
5273 }
5274
5275 /* Check permissions for the transition. */
5276 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5277 PROCESS__DYNTRANSITION, NULL);
5278 if (error)
5279 goto abort_change;
5280
5281 /* Check for ptracing, and update the task SID if ok.
5282 Otherwise, leave SID unchanged and fail. */
5283 ptsid = 0;
5284 task_lock(p);
5285 tracer = tracehook_tracer_task(p);
5286 if (tracer)
5287 ptsid = task_sid(tracer);
5288 task_unlock(p);
5289
5290 if (tracer) {
5291 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5292 PROCESS__PTRACE, NULL);
5293 if (error)
5294 goto abort_change;
5295 }
5296
5297 tsec->sid = sid;
5298 } else {
5299 error = -EINVAL;
5300 goto abort_change;
5301 }
5302
5303 commit_creds(new);
5304 return size;
5305
5306 abort_change:
5307 abort_creds(new);
5308 return error;
5309 }
5310
5311 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5312 {
5313 return security_sid_to_context(secid, secdata, seclen);
5314 }
5315
5316 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5317 {
5318 return security_context_to_sid(secdata, seclen, secid);
5319 }
5320
5321 static void selinux_release_secctx(char *secdata, u32 seclen)
5322 {
5323 kfree(secdata);
5324 }
5325
5326 /*
5327 * called with inode->i_mutex locked
5328 */
5329 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5330 {
5331 return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5332 }
5333
5334 /*
5335 * called with inode->i_mutex locked
5336 */
5337 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
5338 {
5339 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
5340 }
5341
5342 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
5343 {
5344 int len = 0;
5345 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
5346 ctx, true);
5347 if (len < 0)
5348 return len;
5349 *ctxlen = len;
5350 return 0;
5351 }
5352 #ifdef CONFIG_KEYS
5353
5354 static int selinux_key_alloc(struct key *k, const struct cred *cred,
5355 unsigned long flags)
5356 {
5357 const struct task_security_struct *tsec;
5358 struct key_security_struct *ksec;
5359
5360 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
5361 if (!ksec)
5362 return -ENOMEM;
5363
5364 tsec = cred->security;
5365 if (tsec->keycreate_sid)
5366 ksec->sid = tsec->keycreate_sid;
5367 else
5368 ksec->sid = tsec->sid;
5369
5370 k->security = ksec;
5371 return 0;
5372 }
5373
5374 static void selinux_key_free(struct key *k)
5375 {
5376 struct key_security_struct *ksec = k->security;
5377
5378 k->security = NULL;
5379 kfree(ksec);
5380 }
5381
5382 static int selinux_key_permission(key_ref_t key_ref,
5383 const struct cred *cred,
5384 key_perm_t perm)
5385 {
5386 struct key *key;
5387 struct key_security_struct *ksec;
5388 u32 sid;
5389
5390 /* if no specific permissions are requested, we skip the
5391 permission check. No serious, additional covert channels
5392 appear to be created. */
5393 if (perm == 0)
5394 return 0;
5395
5396 sid = cred_sid(cred);
5397
5398 key = key_ref_to_ptr(key_ref);
5399 ksec = key->security;
5400
5401 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5402 }
5403
5404 static int selinux_key_getsecurity(struct key *key, char **_buffer)
5405 {
5406 struct key_security_struct *ksec = key->security;
5407 char *context = NULL;
5408 unsigned len;
5409 int rc;
5410
5411 rc = security_sid_to_context(ksec->sid, &context, &len);
5412 if (!rc)
5413 rc = len;
5414 *_buffer = context;
5415 return rc;
5416 }
5417
5418 #endif
5419
5420 static struct security_operations selinux_ops = {
5421 .name = "selinux",
5422
5423 .ptrace_access_check = selinux_ptrace_access_check,
5424 .ptrace_traceme = selinux_ptrace_traceme,
5425 .capget = selinux_capget,
5426 .capset = selinux_capset,
5427 .capable = selinux_capable,
5428 .quotactl = selinux_quotactl,
5429 .quota_on = selinux_quota_on,
5430 .syslog = selinux_syslog,
5431 .vm_enough_memory = selinux_vm_enough_memory,
5432
5433 .netlink_send = selinux_netlink_send,
5434 .netlink_recv = selinux_netlink_recv,
5435
5436 .bprm_set_creds = selinux_bprm_set_creds,
5437 .bprm_committing_creds = selinux_bprm_committing_creds,
5438 .bprm_committed_creds = selinux_bprm_committed_creds,
5439 .bprm_secureexec = selinux_bprm_secureexec,
5440
5441 .sb_alloc_security = selinux_sb_alloc_security,
5442 .sb_free_security = selinux_sb_free_security,
5443 .sb_copy_data = selinux_sb_copy_data,
5444 .sb_remount = selinux_sb_remount,
5445 .sb_kern_mount = selinux_sb_kern_mount,
5446 .sb_show_options = selinux_sb_show_options,
5447 .sb_statfs = selinux_sb_statfs,
5448 .sb_mount = selinux_mount,
5449 .sb_umount = selinux_umount,
5450 .sb_set_mnt_opts = selinux_set_mnt_opts,
5451 .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts,
5452 .sb_parse_opts_str = selinux_parse_opts_str,
5453
5454
5455 .inode_alloc_security = selinux_inode_alloc_security,
5456 .inode_free_security = selinux_inode_free_security,
5457 .inode_init_security = selinux_inode_init_security,
5458 .inode_create = selinux_inode_create,
5459 .inode_link = selinux_inode_link,
5460 .inode_unlink = selinux_inode_unlink,
5461 .inode_symlink = selinux_inode_symlink,
5462 .inode_mkdir = selinux_inode_mkdir,
5463 .inode_rmdir = selinux_inode_rmdir,
5464 .inode_mknod = selinux_inode_mknod,
5465 .inode_rename = selinux_inode_rename,
5466 .inode_readlink = selinux_inode_readlink,
5467 .inode_follow_link = selinux_inode_follow_link,
5468 .inode_permission = selinux_inode_permission,
5469 .inode_setattr = selinux_inode_setattr,
5470 .inode_getattr = selinux_inode_getattr,
5471 .inode_setxattr = selinux_inode_setxattr,
5472 .inode_post_setxattr = selinux_inode_post_setxattr,
5473 .inode_getxattr = selinux_inode_getxattr,
5474 .inode_listxattr = selinux_inode_listxattr,
5475 .inode_removexattr = selinux_inode_removexattr,
5476 .inode_getsecurity = selinux_inode_getsecurity,
5477 .inode_setsecurity = selinux_inode_setsecurity,
5478 .inode_listsecurity = selinux_inode_listsecurity,
5479 .inode_getsecid = selinux_inode_getsecid,
5480
5481 .file_permission = selinux_file_permission,
5482 .file_alloc_security = selinux_file_alloc_security,
5483 .file_free_security = selinux_file_free_security,
5484 .file_ioctl = selinux_file_ioctl,
5485 .file_mmap = selinux_file_mmap,
5486 .file_mprotect = selinux_file_mprotect,
5487 .file_lock = selinux_file_lock,
5488 .file_fcntl = selinux_file_fcntl,
5489 .file_set_fowner = selinux_file_set_fowner,
5490 .file_send_sigiotask = selinux_file_send_sigiotask,
5491 .file_receive = selinux_file_receive,
5492
5493 .dentry_open = selinux_dentry_open,
5494
5495 .task_create = selinux_task_create,
5496 .cred_alloc_blank = selinux_cred_alloc_blank,
5497 .cred_free = selinux_cred_free,
5498 .cred_prepare = selinux_cred_prepare,
5499 .cred_transfer = selinux_cred_transfer,
5500 .kernel_act_as = selinux_kernel_act_as,
5501 .kernel_create_files_as = selinux_kernel_create_files_as,
5502 .kernel_module_request = selinux_kernel_module_request,
5503 .task_setpgid = selinux_task_setpgid,
5504 .task_getpgid = selinux_task_getpgid,
5505 .task_getsid = selinux_task_getsid,
5506 .task_getsecid = selinux_task_getsecid,
5507 .task_setnice = selinux_task_setnice,
5508 .task_setioprio = selinux_task_setioprio,
5509 .task_getioprio = selinux_task_getioprio,
5510 .task_setrlimit = selinux_task_setrlimit,
5511 .task_setscheduler = selinux_task_setscheduler,
5512 .task_getscheduler = selinux_task_getscheduler,
5513 .task_movememory = selinux_task_movememory,
5514 .task_kill = selinux_task_kill,
5515 .task_wait = selinux_task_wait,
5516 .task_to_inode = selinux_task_to_inode,
5517
5518 .ipc_permission = selinux_ipc_permission,
5519 .ipc_getsecid = selinux_ipc_getsecid,
5520
5521 .msg_msg_alloc_security = selinux_msg_msg_alloc_security,
5522 .msg_msg_free_security = selinux_msg_msg_free_security,
5523
5524 .msg_queue_alloc_security = selinux_msg_queue_alloc_security,
5525 .msg_queue_free_security = selinux_msg_queue_free_security,
5526 .msg_queue_associate = selinux_msg_queue_associate,
5527 .msg_queue_msgctl = selinux_msg_queue_msgctl,
5528 .msg_queue_msgsnd = selinux_msg_queue_msgsnd,
5529 .msg_queue_msgrcv = selinux_msg_queue_msgrcv,
5530
5531 .shm_alloc_security = selinux_shm_alloc_security,
5532 .shm_free_security = selinux_shm_free_security,
5533 .shm_associate = selinux_shm_associate,
5534 .shm_shmctl = selinux_shm_shmctl,
5535 .shm_shmat = selinux_shm_shmat,
5536
5537 .sem_alloc_security = selinux_sem_alloc_security,
5538 .sem_free_security = selinux_sem_free_security,
5539 .sem_associate = selinux_sem_associate,
5540 .sem_semctl = selinux_sem_semctl,
5541 .sem_semop = selinux_sem_semop,
5542
5543 .d_instantiate = selinux_d_instantiate,
5544
5545 .getprocattr = selinux_getprocattr,
5546 .setprocattr = selinux_setprocattr,
5547
5548 .secid_to_secctx = selinux_secid_to_secctx,
5549 .secctx_to_secid = selinux_secctx_to_secid,
5550 .release_secctx = selinux_release_secctx,
5551 .inode_notifysecctx = selinux_inode_notifysecctx,
5552 .inode_setsecctx = selinux_inode_setsecctx,
5553 .inode_getsecctx = selinux_inode_getsecctx,
5554
5555 .unix_stream_connect = selinux_socket_unix_stream_connect,
5556 .unix_may_send = selinux_socket_unix_may_send,
5557
5558 .socket_create = selinux_socket_create,
5559 .socket_post_create = selinux_socket_post_create,
5560 .socket_bind = selinux_socket_bind,
5561 .socket_connect = selinux_socket_connect,
5562 .socket_listen = selinux_socket_listen,
5563 .socket_accept = selinux_socket_accept,
5564 .socket_sendmsg = selinux_socket_sendmsg,
5565 .socket_recvmsg = selinux_socket_recvmsg,
5566 .socket_getsockname = selinux_socket_getsockname,
5567 .socket_getpeername = selinux_socket_getpeername,
5568 .socket_getsockopt = selinux_socket_getsockopt,
5569 .socket_setsockopt = selinux_socket_setsockopt,
5570 .socket_shutdown = selinux_socket_shutdown,
5571 .socket_sock_rcv_skb = selinux_socket_sock_rcv_skb,
5572 .socket_getpeersec_stream = selinux_socket_getpeersec_stream,
5573 .socket_getpeersec_dgram = selinux_socket_getpeersec_dgram,
5574 .sk_alloc_security = selinux_sk_alloc_security,
5575 .sk_free_security = selinux_sk_free_security,
5576 .sk_clone_security = selinux_sk_clone_security,
5577 .sk_getsecid = selinux_sk_getsecid,
5578 .sock_graft = selinux_sock_graft,
5579 .inet_conn_request = selinux_inet_conn_request,
5580 .inet_csk_clone = selinux_inet_csk_clone,
5581 .inet_conn_established = selinux_inet_conn_established,
5582 .secmark_relabel_packet = selinux_secmark_relabel_packet,
5583 .secmark_refcount_inc = selinux_secmark_refcount_inc,
5584 .secmark_refcount_dec = selinux_secmark_refcount_dec,
5585 .req_classify_flow = selinux_req_classify_flow,
5586 .tun_dev_create = selinux_tun_dev_create,
5587 .tun_dev_post_create = selinux_tun_dev_post_create,
5588 .tun_dev_attach = selinux_tun_dev_attach,
5589
5590 #ifdef CONFIG_SECURITY_NETWORK_XFRM
5591 .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc,
5592 .xfrm_policy_clone_security = selinux_xfrm_policy_clone,
5593 .xfrm_policy_free_security = selinux_xfrm_policy_free,
5594 .xfrm_policy_delete_security = selinux_xfrm_policy_delete,
5595 .xfrm_state_alloc_security = selinux_xfrm_state_alloc,
5596 .xfrm_state_free_security = selinux_xfrm_state_free,
5597 .xfrm_state_delete_security = selinux_xfrm_state_delete,
5598 .xfrm_policy_lookup = selinux_xfrm_policy_lookup,
5599 .xfrm_state_pol_flow_match = selinux_xfrm_state_pol_flow_match,
5600 .xfrm_decode_session = selinux_xfrm_decode_session,
5601 #endif
5602
5603 #ifdef CONFIG_KEYS
5604 .key_alloc = selinux_key_alloc,
5605 .key_free = selinux_key_free,
5606 .key_permission = selinux_key_permission,
5607 .key_getsecurity = selinux_key_getsecurity,
5608 #endif
5609
5610 #ifdef CONFIG_AUDIT
5611 .audit_rule_init = selinux_audit_rule_init,
5612 .audit_rule_known = selinux_audit_rule_known,
5613 .audit_rule_match = selinux_audit_rule_match,
5614 .audit_rule_free = selinux_audit_rule_free,
5615 #endif
5616 };
5617
5618 static __init int selinux_init(void)
5619 {
5620 if (!security_module_enable(&selinux_ops)) {
5621 selinux_enabled = 0;
5622 return 0;
5623 }
5624
5625 if (!selinux_enabled) {
5626 printk(KERN_INFO "SELinux: Disabled at boot.\n");
5627 return 0;
5628 }
5629
5630 printk(KERN_INFO "SELinux: Initializing.\n");
5631
5632 /* Set the security state for the initial task. */
5633 cred_init_security();
5634
5635 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
5636
5637 sel_inode_cache = kmem_cache_create("selinux_inode_security",
5638 sizeof(struct inode_security_struct),
5639 0, SLAB_PANIC, NULL);
5640 avc_init();
5641
5642 if (register_security(&selinux_ops))
5643 panic("SELinux: Unable to register with kernel.\n");
5644
5645 if (selinux_enforcing)
5646 printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n");
5647 else
5648 printk(KERN_DEBUG "SELinux: Starting in permissive mode\n");
5649
5650 return 0;
5651 }
5652
5653 static void delayed_superblock_init(struct super_block *sb, void *unused)
5654 {
5655 superblock_doinit(sb, NULL);
5656 }
5657
5658 void selinux_complete_init(void)
5659 {
5660 printk(KERN_DEBUG "SELinux: Completing initialization.\n");
5661
5662 /* Set up any superblocks initialized prior to the policy load. */
5663 printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n");
5664 iterate_supers(delayed_superblock_init, NULL);
5665 }
5666
5667 /* SELinux requires early initialization in order to label
5668 all processes and objects when they are created. */
5669 security_initcall(selinux_init);
5670
5671 #if defined(CONFIG_NETFILTER)
5672
5673 static struct nf_hook_ops selinux_ipv4_ops[] = {
5674 {
5675 .hook = selinux_ipv4_postroute,
5676 .owner = THIS_MODULE,
5677 .pf = PF_INET,
5678 .hooknum = NF_INET_POST_ROUTING,
5679 .priority = NF_IP_PRI_SELINUX_LAST,
5680 },
5681 {
5682 .hook = selinux_ipv4_forward,
5683 .owner = THIS_MODULE,
5684 .pf = PF_INET,
5685 .hooknum = NF_INET_FORWARD,
5686 .priority = NF_IP_PRI_SELINUX_FIRST,
5687 },
5688 {
5689 .hook = selinux_ipv4_output,
5690 .owner = THIS_MODULE,
5691 .pf = PF_INET,
5692 .hooknum = NF_INET_LOCAL_OUT,
5693 .priority = NF_IP_PRI_SELINUX_FIRST,
5694 }
5695 };
5696
5697 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5698
5699 static struct nf_hook_ops selinux_ipv6_ops[] = {
5700 {
5701 .hook = selinux_ipv6_postroute,
5702 .owner = THIS_MODULE,
5703 .pf = PF_INET6,
5704 .hooknum = NF_INET_POST_ROUTING,
5705 .priority = NF_IP6_PRI_SELINUX_LAST,
5706 },
5707 {
5708 .hook = selinux_ipv6_forward,
5709 .owner = THIS_MODULE,
5710 .pf = PF_INET6,
5711 .hooknum = NF_INET_FORWARD,
5712 .priority = NF_IP6_PRI_SELINUX_FIRST,
5713 }
5714 };
5715
5716 #endif /* IPV6 */
5717
5718 static int __init selinux_nf_ip_init(void)
5719 {
5720 int err = 0;
5721
5722 if (!selinux_enabled)
5723 goto out;
5724
5725 printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n");
5726
5727 err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5728 if (err)
5729 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
5730
5731 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5732 err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5733 if (err)
5734 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
5735 #endif /* IPV6 */
5736
5737 out:
5738 return err;
5739 }
5740
5741 __initcall(selinux_nf_ip_init);
5742
5743 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5744 static void selinux_nf_ip_exit(void)
5745 {
5746 printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n");
5747
5748 nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5749 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5750 nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5751 #endif /* IPV6 */
5752 }
5753 #endif
5754
5755 #else /* CONFIG_NETFILTER */
5756
5757 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5758 #define selinux_nf_ip_exit()
5759 #endif
5760
5761 #endif /* CONFIG_NETFILTER */
5762
5763 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5764 static int selinux_disabled;
5765
5766 int selinux_disable(void)
5767 {
5768 extern void exit_sel_fs(void);
5769
5770 if (ss_initialized) {
5771 /* Not permitted after initial policy load. */
5772 return -EINVAL;
5773 }
5774
5775 if (selinux_disabled) {
5776 /* Only do this once. */
5777 return -EINVAL;
5778 }
5779
5780 printk(KERN_INFO "SELinux: Disabled at runtime.\n");
5781
5782 selinux_disabled = 1;
5783 selinux_enabled = 0;
5784
5785 reset_security_ops();
5786
5787 /* Try to destroy the avc node cache */
5788 avc_disable();
5789
5790 /* Unregister netfilter hooks. */
5791 selinux_nf_ip_exit();
5792
5793 /* Unregister selinuxfs. */
5794 exit_sel_fs();
5795
5796 return 0;
5797 }
5798 #endif
Linux kernel - Deliverables
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