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selinux: Set the peer label correctly on connected UNIX domain sockets
[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/kernel.h>
28 #include <linux/tracehook.h>
29 #include <linux/errno.h>
30 #include <linux/sched.h>
31 #include <linux/security.h>
32 #include <linux/xattr.h>
33 #include <linux/capability.h>
34 #include <linux/unistd.h>
35 #include <linux/mm.h>
36 #include <linux/mman.h>
37 #include <linux/slab.h>
38 #include <linux/pagemap.h>
39 #include <linux/swap.h>
40 #include <linux/spinlock.h>
41 #include <linux/syscalls.h>
42 #include <linux/file.h>
43 #include <linux/fdtable.h>
44 #include <linux/namei.h>
45 #include <linux/mount.h>
46 #include <linux/proc_fs.h>
47 #include <linux/netfilter_ipv4.h>
48 #include <linux/netfilter_ipv6.h>
49 #include <linux/tty.h>
50 #include <net/icmp.h>
51 #include <net/ip.h> /* for local_port_range[] */
52 #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
53 #include <net/net_namespace.h>
54 #include <net/netlabel.h>
55 #include <linux/uaccess.h>
56 #include <asm/ioctls.h>
57 #include <asm/atomic.h>
58 #include <linux/bitops.h>
59 #include <linux/interrupt.h>
60 #include <linux/netdevice.h> /* for network interface checks */
61 #include <linux/netlink.h>
62 #include <linux/tcp.h>
63 #include <linux/udp.h>
64 #include <linux/dccp.h>
65 #include <linux/quota.h>
66 #include <linux/un.h> /* for Unix socket types */
67 #include <net/af_unix.h> /* for Unix socket types */
68 #include <linux/parser.h>
69 #include <linux/nfs_mount.h>
70 #include <net/ipv6.h>
71 #include <linux/hugetlb.h>
72 #include <linux/personality.h>
73 #include <linux/sysctl.h>
74 #include <linux/audit.h>
75 #include <linux/string.h>
76 #include <linux/selinux.h>
77 #include <linux/mutex.h>
78 #include <linux/posix-timers.h>
79 #include <linux/syslog.h>
80
81 #include "avc.h"
82 #include "objsec.h"
83 #include "netif.h"
84 #include "netnode.h"
85 #include "netport.h"
86 #include "xfrm.h"
87 #include "netlabel.h"
88 #include "audit.h"
89
90 #define XATTR_SELINUX_SUFFIX "selinux"
91 #define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
92
93 #define NUM_SEL_MNT_OPTS 5
94
95 extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
96 extern struct security_operations *security_ops;
97
98 /* SECMARK reference count */
99 atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
100
101 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
102 int selinux_enforcing;
103
104 static int __init enforcing_setup(char *str)
105 {
106 unsigned long enforcing;
107 if (!strict_strtoul(str, 0, &enforcing))
108 selinux_enforcing = enforcing ? 1 : 0;
109 return 1;
110 }
111 __setup("enforcing=", enforcing_setup);
112 #endif
113
114 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
115 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
116
117 static int __init selinux_enabled_setup(char *str)
118 {
119 unsigned long enabled;
120 if (!strict_strtoul(str, 0, &enabled))
121 selinux_enabled = enabled ? 1 : 0;
122 return 1;
123 }
124 __setup("selinux=", selinux_enabled_setup);
125 #else
126 int selinux_enabled = 1;
127 #endif
128
129 static struct kmem_cache *sel_inode_cache;
130
131 /**
132 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
133 *
134 * Description:
135 * This function checks the SECMARK reference counter to see if any SECMARK
136 * targets are currently configured, if the reference counter is greater than
137 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is
138 * enabled, false (0) if SECMARK is disabled.
139 *
140 */
141 static int selinux_secmark_enabled(void)
142 {
143 return (atomic_read(&selinux_secmark_refcount) > 0);
144 }
145
146 /*
147 * initialise the security for the init task
148 */
149 static void cred_init_security(void)
150 {
151 struct cred *cred = (struct cred *) current->real_cred;
152 struct task_security_struct *tsec;
153
154 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
155 if (!tsec)
156 panic("SELinux: Failed to initialize initial task.\n");
157
158 tsec->osid = tsec->sid = SECINITSID_KERNEL;
159 cred->security = tsec;
160 }
161
162 /*
163 * get the security ID of a set of credentials
164 */
165 static inline u32 cred_sid(const struct cred *cred)
166 {
167 const struct task_security_struct *tsec;
168
169 tsec = cred->security;
170 return tsec->sid;
171 }
172
173 /*
174 * get the objective security ID of a task
175 */
176 static inline u32 task_sid(const struct task_struct *task)
177 {
178 u32 sid;
179
180 rcu_read_lock();
181 sid = cred_sid(__task_cred(task));
182 rcu_read_unlock();
183 return sid;
184 }
185
186 /*
187 * get the subjective security ID of the current task
188 */
189 static inline u32 current_sid(void)
190 {
191 const struct task_security_struct *tsec = current_cred()->security;
192
193 return tsec->sid;
194 }
195
196 /* Allocate and free functions for each kind of security blob. */
197
198 static int inode_alloc_security(struct inode *inode)
199 {
200 struct inode_security_struct *isec;
201 u32 sid = current_sid();
202
203 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
204 if (!isec)
205 return -ENOMEM;
206
207 mutex_init(&isec->lock);
208 INIT_LIST_HEAD(&isec->list);
209 isec->inode = inode;
210 isec->sid = SECINITSID_UNLABELED;
211 isec->sclass = SECCLASS_FILE;
212 isec->task_sid = sid;
213 inode->i_security = isec;
214
215 return 0;
216 }
217
218 static void inode_free_security(struct inode *inode)
219 {
220 struct inode_security_struct *isec = inode->i_security;
221 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
222
223 spin_lock(&sbsec->isec_lock);
224 if (!list_empty(&isec->list))
225 list_del_init(&isec->list);
226 spin_unlock(&sbsec->isec_lock);
227
228 inode->i_security = NULL;
229 kmem_cache_free(sel_inode_cache, isec);
230 }
231
232 static int file_alloc_security(struct file *file)
233 {
234 struct file_security_struct *fsec;
235 u32 sid = current_sid();
236
237 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
238 if (!fsec)
239 return -ENOMEM;
240
241 fsec->sid = sid;
242 fsec->fown_sid = sid;
243 file->f_security = fsec;
244
245 return 0;
246 }
247
248 static void file_free_security(struct file *file)
249 {
250 struct file_security_struct *fsec = file->f_security;
251 file->f_security = NULL;
252 kfree(fsec);
253 }
254
255 static int superblock_alloc_security(struct super_block *sb)
256 {
257 struct superblock_security_struct *sbsec;
258
259 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
260 if (!sbsec)
261 return -ENOMEM;
262
263 mutex_init(&sbsec->lock);
264 INIT_LIST_HEAD(&sbsec->isec_head);
265 spin_lock_init(&sbsec->isec_lock);
266 sbsec->sb = sb;
267 sbsec->sid = SECINITSID_UNLABELED;
268 sbsec->def_sid = SECINITSID_FILE;
269 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
270 sb->s_security = sbsec;
271
272 return 0;
273 }
274
275 static void superblock_free_security(struct super_block *sb)
276 {
277 struct superblock_security_struct *sbsec = sb->s_security;
278 sb->s_security = NULL;
279 kfree(sbsec);
280 }
281
282 static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
283 {
284 struct sk_security_struct *sksec;
285
286 sksec = kzalloc(sizeof(*sksec), priority);
287 if (!sksec)
288 return -ENOMEM;
289
290 sksec->peer_sid = SECINITSID_UNLABELED;
291 sksec->sid = SECINITSID_UNLABELED;
292 sk->sk_security = sksec;
293
294 selinux_netlbl_sk_security_reset(sksec);
295
296 return 0;
297 }
298
299 static void sk_free_security(struct sock *sk)
300 {
301 struct sk_security_struct *sksec = sk->sk_security;
302
303 sk->sk_security = NULL;
304 selinux_netlbl_sk_security_free(sksec);
305 kfree(sksec);
306 }
307
308 /* The security server must be initialized before
309 any labeling or access decisions can be provided. */
310 extern int ss_initialized;
311
312 /* The file system's label must be initialized prior to use. */
313
314 static const char *labeling_behaviors[6] = {
315 "uses xattr",
316 "uses transition SIDs",
317 "uses task SIDs",
318 "uses genfs_contexts",
319 "not configured for labeling",
320 "uses mountpoint labeling",
321 };
322
323 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
324
325 static inline int inode_doinit(struct inode *inode)
326 {
327 return inode_doinit_with_dentry(inode, NULL);
328 }
329
330 enum {
331 Opt_error = -1,
332 Opt_context = 1,
333 Opt_fscontext = 2,
334 Opt_defcontext = 3,
335 Opt_rootcontext = 4,
336 Opt_labelsupport = 5,
337 };
338
339 static const match_table_t tokens = {
340 {Opt_context, CONTEXT_STR "%s"},
341 {Opt_fscontext, FSCONTEXT_STR "%s"},
342 {Opt_defcontext, DEFCONTEXT_STR "%s"},
343 {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
344 {Opt_labelsupport, LABELSUPP_STR},
345 {Opt_error, NULL},
346 };
347
348 #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
349
350 static int may_context_mount_sb_relabel(u32 sid,
351 struct superblock_security_struct *sbsec,
352 const struct cred *cred)
353 {
354 const struct task_security_struct *tsec = cred->security;
355 int rc;
356
357 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
358 FILESYSTEM__RELABELFROM, NULL);
359 if (rc)
360 return rc;
361
362 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
363 FILESYSTEM__RELABELTO, NULL);
364 return rc;
365 }
366
367 static int may_context_mount_inode_relabel(u32 sid,
368 struct superblock_security_struct *sbsec,
369 const struct cred *cred)
370 {
371 const struct task_security_struct *tsec = cred->security;
372 int rc;
373 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
374 FILESYSTEM__RELABELFROM, NULL);
375 if (rc)
376 return rc;
377
378 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
379 FILESYSTEM__ASSOCIATE, NULL);
380 return rc;
381 }
382
383 static int sb_finish_set_opts(struct super_block *sb)
384 {
385 struct superblock_security_struct *sbsec = sb->s_security;
386 struct dentry *root = sb->s_root;
387 struct inode *root_inode = root->d_inode;
388 int rc = 0;
389
390 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
391 /* Make sure that the xattr handler exists and that no
392 error other than -ENODATA is returned by getxattr on
393 the root directory. -ENODATA is ok, as this may be
394 the first boot of the SELinux kernel before we have
395 assigned xattr values to the filesystem. */
396 if (!root_inode->i_op->getxattr) {
397 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
398 "xattr support\n", sb->s_id, sb->s_type->name);
399 rc = -EOPNOTSUPP;
400 goto out;
401 }
402 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
403 if (rc < 0 && rc != -ENODATA) {
404 if (rc == -EOPNOTSUPP)
405 printk(KERN_WARNING "SELinux: (dev %s, type "
406 "%s) has no security xattr handler\n",
407 sb->s_id, sb->s_type->name);
408 else
409 printk(KERN_WARNING "SELinux: (dev %s, type "
410 "%s) getxattr errno %d\n", sb->s_id,
411 sb->s_type->name, -rc);
412 goto out;
413 }
414 }
415
416 sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
417
418 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
419 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
420 sb->s_id, sb->s_type->name);
421 else
422 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
423 sb->s_id, sb->s_type->name,
424 labeling_behaviors[sbsec->behavior-1]);
425
426 if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
427 sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
428 sbsec->behavior == SECURITY_FS_USE_NONE ||
429 sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
430 sbsec->flags &= ~SE_SBLABELSUPP;
431
432 /* Special handling for sysfs. Is genfs but also has setxattr handler*/
433 if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
434 sbsec->flags |= SE_SBLABELSUPP;
435
436 /* Initialize the root inode. */
437 rc = inode_doinit_with_dentry(root_inode, root);
438
439 /* Initialize any other inodes associated with the superblock, e.g.
440 inodes created prior to initial policy load or inodes created
441 during get_sb by a pseudo filesystem that directly
442 populates itself. */
443 spin_lock(&sbsec->isec_lock);
444 next_inode:
445 if (!list_empty(&sbsec->isec_head)) {
446 struct inode_security_struct *isec =
447 list_entry(sbsec->isec_head.next,
448 struct inode_security_struct, list);
449 struct inode *inode = isec->inode;
450 spin_unlock(&sbsec->isec_lock);
451 inode = igrab(inode);
452 if (inode) {
453 if (!IS_PRIVATE(inode))
454 inode_doinit(inode);
455 iput(inode);
456 }
457 spin_lock(&sbsec->isec_lock);
458 list_del_init(&isec->list);
459 goto next_inode;
460 }
461 spin_unlock(&sbsec->isec_lock);
462 out:
463 return rc;
464 }
465
466 /*
467 * This function should allow an FS to ask what it's mount security
468 * options were so it can use those later for submounts, displaying
469 * mount options, or whatever.
470 */
471 static int selinux_get_mnt_opts(const struct super_block *sb,
472 struct security_mnt_opts *opts)
473 {
474 int rc = 0, i;
475 struct superblock_security_struct *sbsec = sb->s_security;
476 char *context = NULL;
477 u32 len;
478 char tmp;
479
480 security_init_mnt_opts(opts);
481
482 if (!(sbsec->flags & SE_SBINITIALIZED))
483 return -EINVAL;
484
485 if (!ss_initialized)
486 return -EINVAL;
487
488 tmp = sbsec->flags & SE_MNTMASK;
489 /* count the number of mount options for this sb */
490 for (i = 0; i < 8; i++) {
491 if (tmp & 0x01)
492 opts->num_mnt_opts++;
493 tmp >>= 1;
494 }
495 /* Check if the Label support flag is set */
496 if (sbsec->flags & SE_SBLABELSUPP)
497 opts->num_mnt_opts++;
498
499 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
500 if (!opts->mnt_opts) {
501 rc = -ENOMEM;
502 goto out_free;
503 }
504
505 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
506 if (!opts->mnt_opts_flags) {
507 rc = -ENOMEM;
508 goto out_free;
509 }
510
511 i = 0;
512 if (sbsec->flags & FSCONTEXT_MNT) {
513 rc = security_sid_to_context(sbsec->sid, &context, &len);
514 if (rc)
515 goto out_free;
516 opts->mnt_opts[i] = context;
517 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
518 }
519 if (sbsec->flags & CONTEXT_MNT) {
520 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
521 if (rc)
522 goto out_free;
523 opts->mnt_opts[i] = context;
524 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
525 }
526 if (sbsec->flags & DEFCONTEXT_MNT) {
527 rc = security_sid_to_context(sbsec->def_sid, &context, &len);
528 if (rc)
529 goto out_free;
530 opts->mnt_opts[i] = context;
531 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
532 }
533 if (sbsec->flags & ROOTCONTEXT_MNT) {
534 struct inode *root = sbsec->sb->s_root->d_inode;
535 struct inode_security_struct *isec = root->i_security;
536
537 rc = security_sid_to_context(isec->sid, &context, &len);
538 if (rc)
539 goto out_free;
540 opts->mnt_opts[i] = context;
541 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
542 }
543 if (sbsec->flags & SE_SBLABELSUPP) {
544 opts->mnt_opts[i] = NULL;
545 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
546 }
547
548 BUG_ON(i != opts->num_mnt_opts);
549
550 return 0;
551
552 out_free:
553 security_free_mnt_opts(opts);
554 return rc;
555 }
556
557 static int bad_option(struct superblock_security_struct *sbsec, char flag,
558 u32 old_sid, u32 new_sid)
559 {
560 char mnt_flags = sbsec->flags & SE_MNTMASK;
561
562 /* check if the old mount command had the same options */
563 if (sbsec->flags & SE_SBINITIALIZED)
564 if (!(sbsec->flags & flag) ||
565 (old_sid != new_sid))
566 return 1;
567
568 /* check if we were passed the same options twice,
569 * aka someone passed context=a,context=b
570 */
571 if (!(sbsec->flags & SE_SBINITIALIZED))
572 if (mnt_flags & flag)
573 return 1;
574 return 0;
575 }
576
577 /*
578 * Allow filesystems with binary mount data to explicitly set mount point
579 * labeling information.
580 */
581 static int selinux_set_mnt_opts(struct super_block *sb,
582 struct security_mnt_opts *opts)
583 {
584 const struct cred *cred = current_cred();
585 int rc = 0, i;
586 struct superblock_security_struct *sbsec = sb->s_security;
587 const char *name = sb->s_type->name;
588 struct inode *inode = sbsec->sb->s_root->d_inode;
589 struct inode_security_struct *root_isec = inode->i_security;
590 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
591 u32 defcontext_sid = 0;
592 char **mount_options = opts->mnt_opts;
593 int *flags = opts->mnt_opts_flags;
594 int num_opts = opts->num_mnt_opts;
595
596 mutex_lock(&sbsec->lock);
597
598 if (!ss_initialized) {
599 if (!num_opts) {
600 /* Defer initialization until selinux_complete_init,
601 after the initial policy is loaded and the security
602 server is ready to handle calls. */
603 goto out;
604 }
605 rc = -EINVAL;
606 printk(KERN_WARNING "SELinux: Unable to set superblock options "
607 "before the security server is initialized\n");
608 goto out;
609 }
610
611 /*
612 * Binary mount data FS will come through this function twice. Once
613 * from an explicit call and once from the generic calls from the vfs.
614 * Since the generic VFS calls will not contain any security mount data
615 * we need to skip the double mount verification.
616 *
617 * This does open a hole in which we will not notice if the first
618 * mount using this sb set explict options and a second mount using
619 * this sb does not set any security options. (The first options
620 * will be used for both mounts)
621 */
622 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
623 && (num_opts == 0))
624 goto out;
625
626 /*
627 * parse the mount options, check if they are valid sids.
628 * also check if someone is trying to mount the same sb more
629 * than once with different security options.
630 */
631 for (i = 0; i < num_opts; i++) {
632 u32 sid;
633
634 if (flags[i] == SE_SBLABELSUPP)
635 continue;
636 rc = security_context_to_sid(mount_options[i],
637 strlen(mount_options[i]), &sid);
638 if (rc) {
639 printk(KERN_WARNING "SELinux: security_context_to_sid"
640 "(%s) failed for (dev %s, type %s) errno=%d\n",
641 mount_options[i], sb->s_id, name, rc);
642 goto out;
643 }
644 switch (flags[i]) {
645 case FSCONTEXT_MNT:
646 fscontext_sid = sid;
647
648 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
649 fscontext_sid))
650 goto out_double_mount;
651
652 sbsec->flags |= FSCONTEXT_MNT;
653 break;
654 case CONTEXT_MNT:
655 context_sid = sid;
656
657 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
658 context_sid))
659 goto out_double_mount;
660
661 sbsec->flags |= CONTEXT_MNT;
662 break;
663 case ROOTCONTEXT_MNT:
664 rootcontext_sid = sid;
665
666 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
667 rootcontext_sid))
668 goto out_double_mount;
669
670 sbsec->flags |= ROOTCONTEXT_MNT;
671
672 break;
673 case DEFCONTEXT_MNT:
674 defcontext_sid = sid;
675
676 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
677 defcontext_sid))
678 goto out_double_mount;
679
680 sbsec->flags |= DEFCONTEXT_MNT;
681
682 break;
683 default:
684 rc = -EINVAL;
685 goto out;
686 }
687 }
688
689 if (sbsec->flags & SE_SBINITIALIZED) {
690 /* previously mounted with options, but not on this attempt? */
691 if ((sbsec->flags & SE_MNTMASK) && !num_opts)
692 goto out_double_mount;
693 rc = 0;
694 goto out;
695 }
696
697 if (strcmp(sb->s_type->name, "proc") == 0)
698 sbsec->flags |= SE_SBPROC;
699
700 /* Determine the labeling behavior to use for this filesystem type. */
701 rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
702 if (rc) {
703 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
704 __func__, sb->s_type->name, rc);
705 goto out;
706 }
707
708 /* sets the context of the superblock for the fs being mounted. */
709 if (fscontext_sid) {
710 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
711 if (rc)
712 goto out;
713
714 sbsec->sid = fscontext_sid;
715 }
716
717 /*
718 * Switch to using mount point labeling behavior.
719 * sets the label used on all file below the mountpoint, and will set
720 * the superblock context if not already set.
721 */
722 if (context_sid) {
723 if (!fscontext_sid) {
724 rc = may_context_mount_sb_relabel(context_sid, sbsec,
725 cred);
726 if (rc)
727 goto out;
728 sbsec->sid = context_sid;
729 } else {
730 rc = may_context_mount_inode_relabel(context_sid, sbsec,
731 cred);
732 if (rc)
733 goto out;
734 }
735 if (!rootcontext_sid)
736 rootcontext_sid = context_sid;
737
738 sbsec->mntpoint_sid = context_sid;
739 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
740 }
741
742 if (rootcontext_sid) {
743 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
744 cred);
745 if (rc)
746 goto out;
747
748 root_isec->sid = rootcontext_sid;
749 root_isec->initialized = 1;
750 }
751
752 if (defcontext_sid) {
753 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
754 rc = -EINVAL;
755 printk(KERN_WARNING "SELinux: defcontext option is "
756 "invalid for this filesystem type\n");
757 goto out;
758 }
759
760 if (defcontext_sid != sbsec->def_sid) {
761 rc = may_context_mount_inode_relabel(defcontext_sid,
762 sbsec, cred);
763 if (rc)
764 goto out;
765 }
766
767 sbsec->def_sid = defcontext_sid;
768 }
769
770 rc = sb_finish_set_opts(sb);
771 out:
772 mutex_unlock(&sbsec->lock);
773 return rc;
774 out_double_mount:
775 rc = -EINVAL;
776 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different "
777 "security settings for (dev %s, type %s)\n", sb->s_id, name);
778 goto out;
779 }
780
781 static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
782 struct super_block *newsb)
783 {
784 const struct superblock_security_struct *oldsbsec = oldsb->s_security;
785 struct superblock_security_struct *newsbsec = newsb->s_security;
786
787 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
788 int set_context = (oldsbsec->flags & CONTEXT_MNT);
789 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
790
791 /*
792 * if the parent was able to be mounted it clearly had no special lsm
793 * mount options. thus we can safely deal with this superblock later
794 */
795 if (!ss_initialized)
796 return;
797
798 /* how can we clone if the old one wasn't set up?? */
799 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
800
801 /* if fs is reusing a sb, just let its options stand... */
802 if (newsbsec->flags & SE_SBINITIALIZED)
803 return;
804
805 mutex_lock(&newsbsec->lock);
806
807 newsbsec->flags = oldsbsec->flags;
808
809 newsbsec->sid = oldsbsec->sid;
810 newsbsec->def_sid = oldsbsec->def_sid;
811 newsbsec->behavior = oldsbsec->behavior;
812
813 if (set_context) {
814 u32 sid = oldsbsec->mntpoint_sid;
815
816 if (!set_fscontext)
817 newsbsec->sid = sid;
818 if (!set_rootcontext) {
819 struct inode *newinode = newsb->s_root->d_inode;
820 struct inode_security_struct *newisec = newinode->i_security;
821 newisec->sid = sid;
822 }
823 newsbsec->mntpoint_sid = sid;
824 }
825 if (set_rootcontext) {
826 const struct inode *oldinode = oldsb->s_root->d_inode;
827 const struct inode_security_struct *oldisec = oldinode->i_security;
828 struct inode *newinode = newsb->s_root->d_inode;
829 struct inode_security_struct *newisec = newinode->i_security;
830
831 newisec->sid = oldisec->sid;
832 }
833
834 sb_finish_set_opts(newsb);
835 mutex_unlock(&newsbsec->lock);
836 }
837
838 static int selinux_parse_opts_str(char *options,
839 struct security_mnt_opts *opts)
840 {
841 char *p;
842 char *context = NULL, *defcontext = NULL;
843 char *fscontext = NULL, *rootcontext = NULL;
844 int rc, num_mnt_opts = 0;
845
846 opts->num_mnt_opts = 0;
847
848 /* Standard string-based options. */
849 while ((p = strsep(&options, "|")) != NULL) {
850 int token;
851 substring_t args[MAX_OPT_ARGS];
852
853 if (!*p)
854 continue;
855
856 token = match_token(p, tokens, args);
857
858 switch (token) {
859 case Opt_context:
860 if (context || defcontext) {
861 rc = -EINVAL;
862 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
863 goto out_err;
864 }
865 context = match_strdup(&args[0]);
866 if (!context) {
867 rc = -ENOMEM;
868 goto out_err;
869 }
870 break;
871
872 case Opt_fscontext:
873 if (fscontext) {
874 rc = -EINVAL;
875 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
876 goto out_err;
877 }
878 fscontext = match_strdup(&args[0]);
879 if (!fscontext) {
880 rc = -ENOMEM;
881 goto out_err;
882 }
883 break;
884
885 case Opt_rootcontext:
886 if (rootcontext) {
887 rc = -EINVAL;
888 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
889 goto out_err;
890 }
891 rootcontext = match_strdup(&args[0]);
892 if (!rootcontext) {
893 rc = -ENOMEM;
894 goto out_err;
895 }
896 break;
897
898 case Opt_defcontext:
899 if (context || defcontext) {
900 rc = -EINVAL;
901 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
902 goto out_err;
903 }
904 defcontext = match_strdup(&args[0]);
905 if (!defcontext) {
906 rc = -ENOMEM;
907 goto out_err;
908 }
909 break;
910 case Opt_labelsupport:
911 break;
912 default:
913 rc = -EINVAL;
914 printk(KERN_WARNING "SELinux: unknown mount option\n");
915 goto out_err;
916
917 }
918 }
919
920 rc = -ENOMEM;
921 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
922 if (!opts->mnt_opts)
923 goto out_err;
924
925 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
926 if (!opts->mnt_opts_flags) {
927 kfree(opts->mnt_opts);
928 goto out_err;
929 }
930
931 if (fscontext) {
932 opts->mnt_opts[num_mnt_opts] = fscontext;
933 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
934 }
935 if (context) {
936 opts->mnt_opts[num_mnt_opts] = context;
937 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
938 }
939 if (rootcontext) {
940 opts->mnt_opts[num_mnt_opts] = rootcontext;
941 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
942 }
943 if (defcontext) {
944 opts->mnt_opts[num_mnt_opts] = defcontext;
945 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
946 }
947
948 opts->num_mnt_opts = num_mnt_opts;
949 return 0;
950
951 out_err:
952 kfree(context);
953 kfree(defcontext);
954 kfree(fscontext);
955 kfree(rootcontext);
956 return rc;
957 }
958 /*
959 * string mount options parsing and call set the sbsec
960 */
961 static int superblock_doinit(struct super_block *sb, void *data)
962 {
963 int rc = 0;
964 char *options = data;
965 struct security_mnt_opts opts;
966
967 security_init_mnt_opts(&opts);
968
969 if (!data)
970 goto out;
971
972 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
973
974 rc = selinux_parse_opts_str(options, &opts);
975 if (rc)
976 goto out_err;
977
978 out:
979 rc = selinux_set_mnt_opts(sb, &opts);
980
981 out_err:
982 security_free_mnt_opts(&opts);
983 return rc;
984 }
985
986 static void selinux_write_opts(struct seq_file *m,
987 struct security_mnt_opts *opts)
988 {
989 int i;
990 char *prefix;
991
992 for (i = 0; i < opts->num_mnt_opts; i++) {
993 char *has_comma;
994
995 if (opts->mnt_opts[i])
996 has_comma = strchr(opts->mnt_opts[i], ',');
997 else
998 has_comma = NULL;
999
1000 switch (opts->mnt_opts_flags[i]) {
1001 case CONTEXT_MNT:
1002 prefix = CONTEXT_STR;
1003 break;
1004 case FSCONTEXT_MNT:
1005 prefix = FSCONTEXT_STR;
1006 break;
1007 case ROOTCONTEXT_MNT:
1008 prefix = ROOTCONTEXT_STR;
1009 break;
1010 case DEFCONTEXT_MNT:
1011 prefix = DEFCONTEXT_STR;
1012 break;
1013 case SE_SBLABELSUPP:
1014 seq_putc(m, ',');
1015 seq_puts(m, LABELSUPP_STR);
1016 continue;
1017 default:
1018 BUG();
1019 };
1020 /* we need a comma before each option */
1021 seq_putc(m, ',');
1022 seq_puts(m, prefix);
1023 if (has_comma)
1024 seq_putc(m, '\"');
1025 seq_puts(m, opts->mnt_opts[i]);
1026 if (has_comma)
1027 seq_putc(m, '\"');
1028 }
1029 }
1030
1031 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1032 {
1033 struct security_mnt_opts opts;
1034 int rc;
1035
1036 rc = selinux_get_mnt_opts(sb, &opts);
1037 if (rc) {
1038 /* before policy load we may get EINVAL, don't show anything */
1039 if (rc == -EINVAL)
1040 rc = 0;
1041 return rc;
1042 }
1043
1044 selinux_write_opts(m, &opts);
1045
1046 security_free_mnt_opts(&opts);
1047
1048 return rc;
1049 }
1050
1051 static inline u16 inode_mode_to_security_class(umode_t mode)
1052 {
1053 switch (mode & S_IFMT) {
1054 case S_IFSOCK:
1055 return SECCLASS_SOCK_FILE;
1056 case S_IFLNK:
1057 return SECCLASS_LNK_FILE;
1058 case S_IFREG:
1059 return SECCLASS_FILE;
1060 case S_IFBLK:
1061 return SECCLASS_BLK_FILE;
1062 case S_IFDIR:
1063 return SECCLASS_DIR;
1064 case S_IFCHR:
1065 return SECCLASS_CHR_FILE;
1066 case S_IFIFO:
1067 return SECCLASS_FIFO_FILE;
1068
1069 }
1070
1071 return SECCLASS_FILE;
1072 }
1073
1074 static inline int default_protocol_stream(int protocol)
1075 {
1076 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1077 }
1078
1079 static inline int default_protocol_dgram(int protocol)
1080 {
1081 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1082 }
1083
1084 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1085 {
1086 switch (family) {
1087 case PF_UNIX:
1088 switch (type) {
1089 case SOCK_STREAM:
1090 case SOCK_SEQPACKET:
1091 return SECCLASS_UNIX_STREAM_SOCKET;
1092 case SOCK_DGRAM:
1093 return SECCLASS_UNIX_DGRAM_SOCKET;
1094 }
1095 break;
1096 case PF_INET:
1097 case PF_INET6:
1098 switch (type) {
1099 case SOCK_STREAM:
1100 if (default_protocol_stream(protocol))
1101 return SECCLASS_TCP_SOCKET;
1102 else
1103 return SECCLASS_RAWIP_SOCKET;
1104 case SOCK_DGRAM:
1105 if (default_protocol_dgram(protocol))
1106 return SECCLASS_UDP_SOCKET;
1107 else
1108 return SECCLASS_RAWIP_SOCKET;
1109 case SOCK_DCCP:
1110 return SECCLASS_DCCP_SOCKET;
1111 default:
1112 return SECCLASS_RAWIP_SOCKET;
1113 }
1114 break;
1115 case PF_NETLINK:
1116 switch (protocol) {
1117 case NETLINK_ROUTE:
1118 return SECCLASS_NETLINK_ROUTE_SOCKET;
1119 case NETLINK_FIREWALL:
1120 return SECCLASS_NETLINK_FIREWALL_SOCKET;
1121 case NETLINK_INET_DIAG:
1122 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1123 case NETLINK_NFLOG:
1124 return SECCLASS_NETLINK_NFLOG_SOCKET;
1125 case NETLINK_XFRM:
1126 return SECCLASS_NETLINK_XFRM_SOCKET;
1127 case NETLINK_SELINUX:
1128 return SECCLASS_NETLINK_SELINUX_SOCKET;
1129 case NETLINK_AUDIT:
1130 return SECCLASS_NETLINK_AUDIT_SOCKET;
1131 case NETLINK_IP6_FW:
1132 return SECCLASS_NETLINK_IP6FW_SOCKET;
1133 case NETLINK_DNRTMSG:
1134 return SECCLASS_NETLINK_DNRT_SOCKET;
1135 case NETLINK_KOBJECT_UEVENT:
1136 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1137 default:
1138 return SECCLASS_NETLINK_SOCKET;
1139 }
1140 case PF_PACKET:
1141 return SECCLASS_PACKET_SOCKET;
1142 case PF_KEY:
1143 return SECCLASS_KEY_SOCKET;
1144 case PF_APPLETALK:
1145 return SECCLASS_APPLETALK_SOCKET;
1146 }
1147
1148 return SECCLASS_SOCKET;
1149 }
1150
1151 #ifdef CONFIG_PROC_FS
1152 static int selinux_proc_get_sid(struct proc_dir_entry *de,
1153 u16 tclass,
1154 u32 *sid)
1155 {
1156 int buflen, rc;
1157 char *buffer, *path, *end;
1158
1159 buffer = (char *)__get_free_page(GFP_KERNEL);
1160 if (!buffer)
1161 return -ENOMEM;
1162
1163 buflen = PAGE_SIZE;
1164 end = buffer+buflen;
1165 *--end = '\0';
1166 buflen--;
1167 path = end-1;
1168 *path = '/';
1169 while (de && de != de->parent) {
1170 buflen -= de->namelen + 1;
1171 if (buflen < 0)
1172 break;
1173 end -= de->namelen;
1174 memcpy(end, de->name, de->namelen);
1175 *--end = '/';
1176 path = end;
1177 de = de->parent;
1178 }
1179 rc = security_genfs_sid("proc", path, tclass, sid);
1180 free_page((unsigned long)buffer);
1181 return rc;
1182 }
1183 #else
1184 static int selinux_proc_get_sid(struct proc_dir_entry *de,
1185 u16 tclass,
1186 u32 *sid)
1187 {
1188 return -EINVAL;
1189 }
1190 #endif
1191
1192 /* The inode's security attributes must be initialized before first use. */
1193 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1194 {
1195 struct superblock_security_struct *sbsec = NULL;
1196 struct inode_security_struct *isec = inode->i_security;
1197 u32 sid;
1198 struct dentry *dentry;
1199 #define INITCONTEXTLEN 255
1200 char *context = NULL;
1201 unsigned len = 0;
1202 int rc = 0;
1203
1204 if (isec->initialized)
1205 goto out;
1206
1207 mutex_lock(&isec->lock);
1208 if (isec->initialized)
1209 goto out_unlock;
1210
1211 sbsec = inode->i_sb->s_security;
1212 if (!(sbsec->flags & SE_SBINITIALIZED)) {
1213 /* Defer initialization until selinux_complete_init,
1214 after the initial policy is loaded and the security
1215 server is ready to handle calls. */
1216 spin_lock(&sbsec->isec_lock);
1217 if (list_empty(&isec->list))
1218 list_add(&isec->list, &sbsec->isec_head);
1219 spin_unlock(&sbsec->isec_lock);
1220 goto out_unlock;
1221 }
1222
1223 switch (sbsec->behavior) {
1224 case SECURITY_FS_USE_XATTR:
1225 if (!inode->i_op->getxattr) {
1226 isec->sid = sbsec->def_sid;
1227 break;
1228 }
1229
1230 /* Need a dentry, since the xattr API requires one.
1231 Life would be simpler if we could just pass the inode. */
1232 if (opt_dentry) {
1233 /* Called from d_instantiate or d_splice_alias. */
1234 dentry = dget(opt_dentry);
1235 } else {
1236 /* Called from selinux_complete_init, try to find a dentry. */
1237 dentry = d_find_alias(inode);
1238 }
1239 if (!dentry) {
1240 /*
1241 * this is can be hit on boot when a file is accessed
1242 * before the policy is loaded. When we load policy we
1243 * may find inodes that have no dentry on the
1244 * sbsec->isec_head list. No reason to complain as these
1245 * will get fixed up the next time we go through
1246 * inode_doinit with a dentry, before these inodes could
1247 * be used again by userspace.
1248 */
1249 goto out_unlock;
1250 }
1251
1252 len = INITCONTEXTLEN;
1253 context = kmalloc(len+1, GFP_NOFS);
1254 if (!context) {
1255 rc = -ENOMEM;
1256 dput(dentry);
1257 goto out_unlock;
1258 }
1259 context[len] = '\0';
1260 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1261 context, len);
1262 if (rc == -ERANGE) {
1263 kfree(context);
1264
1265 /* Need a larger buffer. Query for the right size. */
1266 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1267 NULL, 0);
1268 if (rc < 0) {
1269 dput(dentry);
1270 goto out_unlock;
1271 }
1272 len = rc;
1273 context = kmalloc(len+1, GFP_NOFS);
1274 if (!context) {
1275 rc = -ENOMEM;
1276 dput(dentry);
1277 goto out_unlock;
1278 }
1279 context[len] = '\0';
1280 rc = inode->i_op->getxattr(dentry,
1281 XATTR_NAME_SELINUX,
1282 context, len);
1283 }
1284 dput(dentry);
1285 if (rc < 0) {
1286 if (rc != -ENODATA) {
1287 printk(KERN_WARNING "SELinux: %s: getxattr returned "
1288 "%d for dev=%s ino=%ld\n", __func__,
1289 -rc, inode->i_sb->s_id, inode->i_ino);
1290 kfree(context);
1291 goto out_unlock;
1292 }
1293 /* Map ENODATA to the default file SID */
1294 sid = sbsec->def_sid;
1295 rc = 0;
1296 } else {
1297 rc = security_context_to_sid_default(context, rc, &sid,
1298 sbsec->def_sid,
1299 GFP_NOFS);
1300 if (rc) {
1301 char *dev = inode->i_sb->s_id;
1302 unsigned long ino = inode->i_ino;
1303
1304 if (rc == -EINVAL) {
1305 if (printk_ratelimit())
1306 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
1307 "context=%s. This indicates you may need to relabel the inode or the "
1308 "filesystem in question.\n", ino, dev, context);
1309 } else {
1310 printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) "
1311 "returned %d for dev=%s ino=%ld\n",
1312 __func__, context, -rc, dev, ino);
1313 }
1314 kfree(context);
1315 /* Leave with the unlabeled SID */
1316 rc = 0;
1317 break;
1318 }
1319 }
1320 kfree(context);
1321 isec->sid = sid;
1322 break;
1323 case SECURITY_FS_USE_TASK:
1324 isec->sid = isec->task_sid;
1325 break;
1326 case SECURITY_FS_USE_TRANS:
1327 /* Default to the fs SID. */
1328 isec->sid = sbsec->sid;
1329
1330 /* Try to obtain a transition SID. */
1331 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1332 rc = security_transition_sid(isec->task_sid,
1333 sbsec->sid,
1334 isec->sclass,
1335 &sid);
1336 if (rc)
1337 goto out_unlock;
1338 isec->sid = sid;
1339 break;
1340 case SECURITY_FS_USE_MNTPOINT:
1341 isec->sid = sbsec->mntpoint_sid;
1342 break;
1343 default:
1344 /* Default to the fs superblock SID. */
1345 isec->sid = sbsec->sid;
1346
1347 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
1348 struct proc_inode *proci = PROC_I(inode);
1349 if (proci->pde) {
1350 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1351 rc = selinux_proc_get_sid(proci->pde,
1352 isec->sclass,
1353 &sid);
1354 if (rc)
1355 goto out_unlock;
1356 isec->sid = sid;
1357 }
1358 }
1359 break;
1360 }
1361
1362 isec->initialized = 1;
1363
1364 out_unlock:
1365 mutex_unlock(&isec->lock);
1366 out:
1367 if (isec->sclass == SECCLASS_FILE)
1368 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1369 return rc;
1370 }
1371
1372 /* Convert a Linux signal to an access vector. */
1373 static inline u32 signal_to_av(int sig)
1374 {
1375 u32 perm = 0;
1376
1377 switch (sig) {
1378 case SIGCHLD:
1379 /* Commonly granted from child to parent. */
1380 perm = PROCESS__SIGCHLD;
1381 break;
1382 case SIGKILL:
1383 /* Cannot be caught or ignored */
1384 perm = PROCESS__SIGKILL;
1385 break;
1386 case SIGSTOP:
1387 /* Cannot be caught or ignored */
1388 perm = PROCESS__SIGSTOP;
1389 break;
1390 default:
1391 /* All other signals. */
1392 perm = PROCESS__SIGNAL;
1393 break;
1394 }
1395
1396 return perm;
1397 }
1398
1399 /*
1400 * Check permission between a pair of credentials
1401 * fork check, ptrace check, etc.
1402 */
1403 static int cred_has_perm(const struct cred *actor,
1404 const struct cred *target,
1405 u32 perms)
1406 {
1407 u32 asid = cred_sid(actor), tsid = cred_sid(target);
1408
1409 return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1410 }
1411
1412 /*
1413 * Check permission between a pair of tasks, e.g. signal checks,
1414 * fork check, ptrace check, etc.
1415 * tsk1 is the actor and tsk2 is the target
1416 * - this uses the default subjective creds of tsk1
1417 */
1418 static int task_has_perm(const struct task_struct *tsk1,
1419 const struct task_struct *tsk2,
1420 u32 perms)
1421 {
1422 const struct task_security_struct *__tsec1, *__tsec2;
1423 u32 sid1, sid2;
1424
1425 rcu_read_lock();
1426 __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid;
1427 __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid;
1428 rcu_read_unlock();
1429 return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1430 }
1431
1432 /*
1433 * Check permission between current and another task, e.g. signal checks,
1434 * fork check, ptrace check, etc.
1435 * current is the actor and tsk2 is the target
1436 * - this uses current's subjective creds
1437 */
1438 static int current_has_perm(const struct task_struct *tsk,
1439 u32 perms)
1440 {
1441 u32 sid, tsid;
1442
1443 sid = current_sid();
1444 tsid = task_sid(tsk);
1445 return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1446 }
1447
1448 #if CAP_LAST_CAP > 63
1449 #error Fix SELinux to handle capabilities > 63.
1450 #endif
1451
1452 /* Check whether a task is allowed to use a capability. */
1453 static int task_has_capability(struct task_struct *tsk,
1454 const struct cred *cred,
1455 int cap, int audit)
1456 {
1457 struct common_audit_data ad;
1458 struct av_decision avd;
1459 u16 sclass;
1460 u32 sid = cred_sid(cred);
1461 u32 av = CAP_TO_MASK(cap);
1462 int rc;
1463
1464 COMMON_AUDIT_DATA_INIT(&ad, CAP);
1465 ad.tsk = tsk;
1466 ad.u.cap = cap;
1467
1468 switch (CAP_TO_INDEX(cap)) {
1469 case 0:
1470 sclass = SECCLASS_CAPABILITY;
1471 break;
1472 case 1:
1473 sclass = SECCLASS_CAPABILITY2;
1474 break;
1475 default:
1476 printk(KERN_ERR
1477 "SELinux: out of range capability %d\n", cap);
1478 BUG();
1479 }
1480
1481 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1482 if (audit == SECURITY_CAP_AUDIT)
1483 avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1484 return rc;
1485 }
1486
1487 /* Check whether a task is allowed to use a system operation. */
1488 static int task_has_system(struct task_struct *tsk,
1489 u32 perms)
1490 {
1491 u32 sid = task_sid(tsk);
1492
1493 return avc_has_perm(sid, SECINITSID_KERNEL,
1494 SECCLASS_SYSTEM, perms, NULL);
1495 }
1496
1497 /* Check whether a task has a particular permission to an inode.
1498 The 'adp' parameter is optional and allows other audit
1499 data to be passed (e.g. the dentry). */
1500 static int inode_has_perm(const struct cred *cred,
1501 struct inode *inode,
1502 u32 perms,
1503 struct common_audit_data *adp)
1504 {
1505 struct inode_security_struct *isec;
1506 struct common_audit_data ad;
1507 u32 sid;
1508
1509 validate_creds(cred);
1510
1511 if (unlikely(IS_PRIVATE(inode)))
1512 return 0;
1513
1514 sid = cred_sid(cred);
1515 isec = inode->i_security;
1516
1517 if (!adp) {
1518 adp = &ad;
1519 COMMON_AUDIT_DATA_INIT(&ad, FS);
1520 ad.u.fs.inode = inode;
1521 }
1522
1523 return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1524 }
1525
1526 /* Same as inode_has_perm, but pass explicit audit data containing
1527 the dentry to help the auditing code to more easily generate the
1528 pathname if needed. */
1529 static inline int dentry_has_perm(const struct cred *cred,
1530 struct vfsmount *mnt,
1531 struct dentry *dentry,
1532 u32 av)
1533 {
1534 struct inode *inode = dentry->d_inode;
1535 struct common_audit_data ad;
1536
1537 COMMON_AUDIT_DATA_INIT(&ad, FS);
1538 ad.u.fs.path.mnt = mnt;
1539 ad.u.fs.path.dentry = dentry;
1540 return inode_has_perm(cred, inode, av, &ad);
1541 }
1542
1543 /* Check whether a task can use an open file descriptor to
1544 access an inode in a given way. Check access to the
1545 descriptor itself, and then use dentry_has_perm to
1546 check a particular permission to the file.
1547 Access to the descriptor is implicitly granted if it
1548 has the same SID as the process. If av is zero, then
1549 access to the file is not checked, e.g. for cases
1550 where only the descriptor is affected like seek. */
1551 static int file_has_perm(const struct cred *cred,
1552 struct file *file,
1553 u32 av)
1554 {
1555 struct file_security_struct *fsec = file->f_security;
1556 struct inode *inode = file->f_path.dentry->d_inode;
1557 struct common_audit_data ad;
1558 u32 sid = cred_sid(cred);
1559 int rc;
1560
1561 COMMON_AUDIT_DATA_INIT(&ad, FS);
1562 ad.u.fs.path = file->f_path;
1563
1564 if (sid != fsec->sid) {
1565 rc = avc_has_perm(sid, fsec->sid,
1566 SECCLASS_FD,
1567 FD__USE,
1568 &ad);
1569 if (rc)
1570 goto out;
1571 }
1572
1573 /* av is zero if only checking access to the descriptor. */
1574 rc = 0;
1575 if (av)
1576 rc = inode_has_perm(cred, inode, av, &ad);
1577
1578 out:
1579 return rc;
1580 }
1581
1582 /* Check whether a task can create a file. */
1583 static int may_create(struct inode *dir,
1584 struct dentry *dentry,
1585 u16 tclass)
1586 {
1587 const struct cred *cred = current_cred();
1588 const struct task_security_struct *tsec = cred->security;
1589 struct inode_security_struct *dsec;
1590 struct superblock_security_struct *sbsec;
1591 u32 sid, newsid;
1592 struct common_audit_data ad;
1593 int rc;
1594
1595 dsec = dir->i_security;
1596 sbsec = dir->i_sb->s_security;
1597
1598 sid = tsec->sid;
1599 newsid = tsec->create_sid;
1600
1601 COMMON_AUDIT_DATA_INIT(&ad, FS);
1602 ad.u.fs.path.dentry = dentry;
1603
1604 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1605 DIR__ADD_NAME | DIR__SEARCH,
1606 &ad);
1607 if (rc)
1608 return rc;
1609
1610 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
1611 rc = security_transition_sid(sid, dsec->sid, tclass, &newsid);
1612 if (rc)
1613 return rc;
1614 }
1615
1616 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1617 if (rc)
1618 return rc;
1619
1620 return avc_has_perm(newsid, sbsec->sid,
1621 SECCLASS_FILESYSTEM,
1622 FILESYSTEM__ASSOCIATE, &ad);
1623 }
1624
1625 /* Check whether a task can create a key. */
1626 static int may_create_key(u32 ksid,
1627 struct task_struct *ctx)
1628 {
1629 u32 sid = task_sid(ctx);
1630
1631 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1632 }
1633
1634 #define MAY_LINK 0
1635 #define MAY_UNLINK 1
1636 #define MAY_RMDIR 2
1637
1638 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1639 static int may_link(struct inode *dir,
1640 struct dentry *dentry,
1641 int kind)
1642
1643 {
1644 struct inode_security_struct *dsec, *isec;
1645 struct common_audit_data ad;
1646 u32 sid = current_sid();
1647 u32 av;
1648 int rc;
1649
1650 dsec = dir->i_security;
1651 isec = dentry->d_inode->i_security;
1652
1653 COMMON_AUDIT_DATA_INIT(&ad, FS);
1654 ad.u.fs.path.dentry = dentry;
1655
1656 av = DIR__SEARCH;
1657 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1658 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1659 if (rc)
1660 return rc;
1661
1662 switch (kind) {
1663 case MAY_LINK:
1664 av = FILE__LINK;
1665 break;
1666 case MAY_UNLINK:
1667 av = FILE__UNLINK;
1668 break;
1669 case MAY_RMDIR:
1670 av = DIR__RMDIR;
1671 break;
1672 default:
1673 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n",
1674 __func__, kind);
1675 return 0;
1676 }
1677
1678 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1679 return rc;
1680 }
1681
1682 static inline int may_rename(struct inode *old_dir,
1683 struct dentry *old_dentry,
1684 struct inode *new_dir,
1685 struct dentry *new_dentry)
1686 {
1687 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1688 struct common_audit_data ad;
1689 u32 sid = current_sid();
1690 u32 av;
1691 int old_is_dir, new_is_dir;
1692 int rc;
1693
1694 old_dsec = old_dir->i_security;
1695 old_isec = old_dentry->d_inode->i_security;
1696 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1697 new_dsec = new_dir->i_security;
1698
1699 COMMON_AUDIT_DATA_INIT(&ad, FS);
1700
1701 ad.u.fs.path.dentry = old_dentry;
1702 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1703 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1704 if (rc)
1705 return rc;
1706 rc = avc_has_perm(sid, old_isec->sid,
1707 old_isec->sclass, FILE__RENAME, &ad);
1708 if (rc)
1709 return rc;
1710 if (old_is_dir && new_dir != old_dir) {
1711 rc = avc_has_perm(sid, old_isec->sid,
1712 old_isec->sclass, DIR__REPARENT, &ad);
1713 if (rc)
1714 return rc;
1715 }
1716
1717 ad.u.fs.path.dentry = new_dentry;
1718 av = DIR__ADD_NAME | DIR__SEARCH;
1719 if (new_dentry->d_inode)
1720 av |= DIR__REMOVE_NAME;
1721 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1722 if (rc)
1723 return rc;
1724 if (new_dentry->d_inode) {
1725 new_isec = new_dentry->d_inode->i_security;
1726 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1727 rc = avc_has_perm(sid, new_isec->sid,
1728 new_isec->sclass,
1729 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1730 if (rc)
1731 return rc;
1732 }
1733
1734 return 0;
1735 }
1736
1737 /* Check whether a task can perform a filesystem operation. */
1738 static int superblock_has_perm(const struct cred *cred,
1739 struct super_block *sb,
1740 u32 perms,
1741 struct common_audit_data *ad)
1742 {
1743 struct superblock_security_struct *sbsec;
1744 u32 sid = cred_sid(cred);
1745
1746 sbsec = sb->s_security;
1747 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1748 }
1749
1750 /* Convert a Linux mode and permission mask to an access vector. */
1751 static inline u32 file_mask_to_av(int mode, int mask)
1752 {
1753 u32 av = 0;
1754
1755 if ((mode & S_IFMT) != S_IFDIR) {
1756 if (mask & MAY_EXEC)
1757 av |= FILE__EXECUTE;
1758 if (mask & MAY_READ)
1759 av |= FILE__READ;
1760
1761 if (mask & MAY_APPEND)
1762 av |= FILE__APPEND;
1763 else if (mask & MAY_WRITE)
1764 av |= FILE__WRITE;
1765
1766 } else {
1767 if (mask & MAY_EXEC)
1768 av |= DIR__SEARCH;
1769 if (mask & MAY_WRITE)
1770 av |= DIR__WRITE;
1771 if (mask & MAY_READ)
1772 av |= DIR__READ;
1773 }
1774
1775 return av;
1776 }
1777
1778 /* Convert a Linux file to an access vector. */
1779 static inline u32 file_to_av(struct file *file)
1780 {
1781 u32 av = 0;
1782
1783 if (file->f_mode & FMODE_READ)
1784 av |= FILE__READ;
1785 if (file->f_mode & FMODE_WRITE) {
1786 if (file->f_flags & O_APPEND)
1787 av |= FILE__APPEND;
1788 else
1789 av |= FILE__WRITE;
1790 }
1791 if (!av) {
1792 /*
1793 * Special file opened with flags 3 for ioctl-only use.
1794 */
1795 av = FILE__IOCTL;
1796 }
1797
1798 return av;
1799 }
1800
1801 /*
1802 * Convert a file to an access vector and include the correct open
1803 * open permission.
1804 */
1805 static inline u32 open_file_to_av(struct file *file)
1806 {
1807 u32 av = file_to_av(file);
1808
1809 if (selinux_policycap_openperm) {
1810 mode_t mode = file->f_path.dentry->d_inode->i_mode;
1811 /*
1812 * lnk files and socks do not really have an 'open'
1813 */
1814 if (S_ISREG(mode))
1815 av |= FILE__OPEN;
1816 else if (S_ISCHR(mode))
1817 av |= CHR_FILE__OPEN;
1818 else if (S_ISBLK(mode))
1819 av |= BLK_FILE__OPEN;
1820 else if (S_ISFIFO(mode))
1821 av |= FIFO_FILE__OPEN;
1822 else if (S_ISDIR(mode))
1823 av |= DIR__OPEN;
1824 else if (S_ISSOCK(mode))
1825 av |= SOCK_FILE__OPEN;
1826 else
1827 printk(KERN_ERR "SELinux: WARNING: inside %s with "
1828 "unknown mode:%o\n", __func__, mode);
1829 }
1830 return av;
1831 }
1832
1833 /* Hook functions begin here. */
1834
1835 static int selinux_ptrace_access_check(struct task_struct *child,
1836 unsigned int mode)
1837 {
1838 int rc;
1839
1840 rc = cap_ptrace_access_check(child, mode);
1841 if (rc)
1842 return rc;
1843
1844 if (mode == PTRACE_MODE_READ) {
1845 u32 sid = current_sid();
1846 u32 csid = task_sid(child);
1847 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
1848 }
1849
1850 return current_has_perm(child, PROCESS__PTRACE);
1851 }
1852
1853 static int selinux_ptrace_traceme(struct task_struct *parent)
1854 {
1855 int rc;
1856
1857 rc = cap_ptrace_traceme(parent);
1858 if (rc)
1859 return rc;
1860
1861 return task_has_perm(parent, current, PROCESS__PTRACE);
1862 }
1863
1864 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1865 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1866 {
1867 int error;
1868
1869 error = current_has_perm(target, PROCESS__GETCAP);
1870 if (error)
1871 return error;
1872
1873 return cap_capget(target, effective, inheritable, permitted);
1874 }
1875
1876 static int selinux_capset(struct cred *new, const struct cred *old,
1877 const kernel_cap_t *effective,
1878 const kernel_cap_t *inheritable,
1879 const kernel_cap_t *permitted)
1880 {
1881 int error;
1882
1883 error = cap_capset(new, old,
1884 effective, inheritable, permitted);
1885 if (error)
1886 return error;
1887
1888 return cred_has_perm(old, new, PROCESS__SETCAP);
1889 }
1890
1891 /*
1892 * (This comment used to live with the selinux_task_setuid hook,
1893 * which was removed).
1894 *
1895 * Since setuid only affects the current process, and since the SELinux
1896 * controls are not based on the Linux identity attributes, SELinux does not
1897 * need to control this operation. However, SELinux does control the use of
1898 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
1899 */
1900
1901 static int selinux_capable(struct task_struct *tsk, const struct cred *cred,
1902 int cap, int audit)
1903 {
1904 int rc;
1905
1906 rc = cap_capable(tsk, cred, cap, audit);
1907 if (rc)
1908 return rc;
1909
1910 return task_has_capability(tsk, cred, cap, audit);
1911 }
1912
1913 static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid)
1914 {
1915 int buflen, rc;
1916 char *buffer, *path, *end;
1917
1918 rc = -ENOMEM;
1919 buffer = (char *)__get_free_page(GFP_KERNEL);
1920 if (!buffer)
1921 goto out;
1922
1923 buflen = PAGE_SIZE;
1924 end = buffer+buflen;
1925 *--end = '\0';
1926 buflen--;
1927 path = end-1;
1928 *path = '/';
1929 while (table) {
1930 const char *name = table->procname;
1931 size_t namelen = strlen(name);
1932 buflen -= namelen + 1;
1933 if (buflen < 0)
1934 goto out_free;
1935 end -= namelen;
1936 memcpy(end, name, namelen);
1937 *--end = '/';
1938 path = end;
1939 table = table->parent;
1940 }
1941 buflen -= 4;
1942 if (buflen < 0)
1943 goto out_free;
1944 end -= 4;
1945 memcpy(end, "/sys", 4);
1946 path = end;
1947 rc = security_genfs_sid("proc", path, tclass, sid);
1948 out_free:
1949 free_page((unsigned long)buffer);
1950 out:
1951 return rc;
1952 }
1953
1954 static int selinux_sysctl(ctl_table *table, int op)
1955 {
1956 int error = 0;
1957 u32 av;
1958 u32 tsid, sid;
1959 int rc;
1960
1961 sid = current_sid();
1962
1963 rc = selinux_sysctl_get_sid(table, (op == 0001) ?
1964 SECCLASS_DIR : SECCLASS_FILE, &tsid);
1965 if (rc) {
1966 /* Default to the well-defined sysctl SID. */
1967 tsid = SECINITSID_SYSCTL;
1968 }
1969
1970 /* The op values are "defined" in sysctl.c, thereby creating
1971 * a bad coupling between this module and sysctl.c */
1972 if (op == 001) {
1973 error = avc_has_perm(sid, tsid,
1974 SECCLASS_DIR, DIR__SEARCH, NULL);
1975 } else {
1976 av = 0;
1977 if (op & 004)
1978 av |= FILE__READ;
1979 if (op & 002)
1980 av |= FILE__WRITE;
1981 if (av)
1982 error = avc_has_perm(sid, tsid,
1983 SECCLASS_FILE, av, NULL);
1984 }
1985
1986 return error;
1987 }
1988
1989 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1990 {
1991 const struct cred *cred = current_cred();
1992 int rc = 0;
1993
1994 if (!sb)
1995 return 0;
1996
1997 switch (cmds) {
1998 case Q_SYNC:
1999 case Q_QUOTAON:
2000 case Q_QUOTAOFF:
2001 case Q_SETINFO:
2002 case Q_SETQUOTA:
2003 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2004 break;
2005 case Q_GETFMT:
2006 case Q_GETINFO:
2007 case Q_GETQUOTA:
2008 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2009 break;
2010 default:
2011 rc = 0; /* let the kernel handle invalid cmds */
2012 break;
2013 }
2014 return rc;
2015 }
2016
2017 static int selinux_quota_on(struct dentry *dentry)
2018 {
2019 const struct cred *cred = current_cred();
2020
2021 return dentry_has_perm(cred, NULL, dentry, FILE__QUOTAON);
2022 }
2023
2024 static int selinux_syslog(int type, bool from_file)
2025 {
2026 int rc;
2027
2028 rc = cap_syslog(type, from_file);
2029 if (rc)
2030 return rc;
2031
2032 switch (type) {
2033 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
2034 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
2035 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
2036 break;
2037 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
2038 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */
2039 /* Set level of messages printed to console */
2040 case SYSLOG_ACTION_CONSOLE_LEVEL:
2041 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
2042 break;
2043 case SYSLOG_ACTION_CLOSE: /* Close log */
2044 case SYSLOG_ACTION_OPEN: /* Open log */
2045 case SYSLOG_ACTION_READ: /* Read from log */
2046 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */
2047 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */
2048 default:
2049 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
2050 break;
2051 }
2052 return rc;
2053 }
2054
2055 /*
2056 * Check that a process has enough memory to allocate a new virtual
2057 * mapping. 0 means there is enough memory for the allocation to
2058 * succeed and -ENOMEM implies there is not.
2059 *
2060 * Do not audit the selinux permission check, as this is applied to all
2061 * processes that allocate mappings.
2062 */
2063 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2064 {
2065 int rc, cap_sys_admin = 0;
2066
2067 rc = selinux_capable(current, current_cred(), CAP_SYS_ADMIN,
2068 SECURITY_CAP_NOAUDIT);
2069 if (rc == 0)
2070 cap_sys_admin = 1;
2071
2072 return __vm_enough_memory(mm, pages, cap_sys_admin);
2073 }
2074
2075 /* binprm security operations */
2076
2077 static int selinux_bprm_set_creds(struct linux_binprm *bprm)
2078 {
2079 const struct task_security_struct *old_tsec;
2080 struct task_security_struct *new_tsec;
2081 struct inode_security_struct *isec;
2082 struct common_audit_data ad;
2083 struct inode *inode = bprm->file->f_path.dentry->d_inode;
2084 int rc;
2085
2086 rc = cap_bprm_set_creds(bprm);
2087 if (rc)
2088 return rc;
2089
2090 /* SELinux context only depends on initial program or script and not
2091 * the script interpreter */
2092 if (bprm->cred_prepared)
2093 return 0;
2094
2095 old_tsec = current_security();
2096 new_tsec = bprm->cred->security;
2097 isec = inode->i_security;
2098
2099 /* Default to the current task SID. */
2100 new_tsec->sid = old_tsec->sid;
2101 new_tsec->osid = old_tsec->sid;
2102
2103 /* Reset fs, key, and sock SIDs on execve. */
2104 new_tsec->create_sid = 0;
2105 new_tsec->keycreate_sid = 0;
2106 new_tsec->sockcreate_sid = 0;
2107
2108 if (old_tsec->exec_sid) {
2109 new_tsec->sid = old_tsec->exec_sid;
2110 /* Reset exec SID on execve. */
2111 new_tsec->exec_sid = 0;
2112 } else {
2113 /* Check for a default transition on this program. */
2114 rc = security_transition_sid(old_tsec->sid, isec->sid,
2115 SECCLASS_PROCESS, &new_tsec->sid);
2116 if (rc)
2117 return rc;
2118 }
2119
2120 COMMON_AUDIT_DATA_INIT(&ad, FS);
2121 ad.u.fs.path = bprm->file->f_path;
2122
2123 if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
2124 new_tsec->sid = old_tsec->sid;
2125
2126 if (new_tsec->sid == old_tsec->sid) {
2127 rc = avc_has_perm(old_tsec->sid, isec->sid,
2128 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2129 if (rc)
2130 return rc;
2131 } else {
2132 /* Check permissions for the transition. */
2133 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2134 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2135 if (rc)
2136 return rc;
2137
2138 rc = avc_has_perm(new_tsec->sid, isec->sid,
2139 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2140 if (rc)
2141 return rc;
2142
2143 /* Check for shared state */
2144 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2145 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2146 SECCLASS_PROCESS, PROCESS__SHARE,
2147 NULL);
2148 if (rc)
2149 return -EPERM;
2150 }
2151
2152 /* Make sure that anyone attempting to ptrace over a task that
2153 * changes its SID has the appropriate permit */
2154 if (bprm->unsafe &
2155 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2156 struct task_struct *tracer;
2157 struct task_security_struct *sec;
2158 u32 ptsid = 0;
2159
2160 rcu_read_lock();
2161 tracer = tracehook_tracer_task(current);
2162 if (likely(tracer != NULL)) {
2163 sec = __task_cred(tracer)->security;
2164 ptsid = sec->sid;
2165 }
2166 rcu_read_unlock();
2167
2168 if (ptsid != 0) {
2169 rc = avc_has_perm(ptsid, new_tsec->sid,
2170 SECCLASS_PROCESS,
2171 PROCESS__PTRACE, NULL);
2172 if (rc)
2173 return -EPERM;
2174 }
2175 }
2176
2177 /* Clear any possibly unsafe personality bits on exec: */
2178 bprm->per_clear |= PER_CLEAR_ON_SETID;
2179 }
2180
2181 return 0;
2182 }
2183
2184 static int selinux_bprm_secureexec(struct linux_binprm *bprm)
2185 {
2186 const struct cred *cred = current_cred();
2187 const struct task_security_struct *tsec = cred->security;
2188 u32 sid, osid;
2189 int atsecure = 0;
2190
2191 sid = tsec->sid;
2192 osid = tsec->osid;
2193
2194 if (osid != sid) {
2195 /* Enable secure mode for SIDs transitions unless
2196 the noatsecure permission is granted between
2197 the two SIDs, i.e. ahp returns 0. */
2198 atsecure = avc_has_perm(osid, sid,
2199 SECCLASS_PROCESS,
2200 PROCESS__NOATSECURE, NULL);
2201 }
2202
2203 return (atsecure || cap_bprm_secureexec(bprm));
2204 }
2205
2206 extern struct vfsmount *selinuxfs_mount;
2207 extern struct dentry *selinux_null;
2208
2209 /* Derived from fs/exec.c:flush_old_files. */
2210 static inline void flush_unauthorized_files(const struct cred *cred,
2211 struct files_struct *files)
2212 {
2213 struct common_audit_data ad;
2214 struct file *file, *devnull = NULL;
2215 struct tty_struct *tty;
2216 struct fdtable *fdt;
2217 long j = -1;
2218 int drop_tty = 0;
2219
2220 tty = get_current_tty();
2221 if (tty) {
2222 file_list_lock();
2223 if (!list_empty(&tty->tty_files)) {
2224 struct inode *inode;
2225
2226 /* Revalidate access to controlling tty.
2227 Use inode_has_perm on the tty inode directly rather
2228 than using file_has_perm, as this particular open
2229 file may belong to another process and we are only
2230 interested in the inode-based check here. */
2231 file = list_first_entry(&tty->tty_files, struct file, f_u.fu_list);
2232 inode = file->f_path.dentry->d_inode;
2233 if (inode_has_perm(cred, inode,
2234 FILE__READ | FILE__WRITE, NULL)) {
2235 drop_tty = 1;
2236 }
2237 }
2238 file_list_unlock();
2239 tty_kref_put(tty);
2240 }
2241 /* Reset controlling tty. */
2242 if (drop_tty)
2243 no_tty();
2244
2245 /* Revalidate access to inherited open files. */
2246
2247 COMMON_AUDIT_DATA_INIT(&ad, FS);
2248
2249 spin_lock(&files->file_lock);
2250 for (;;) {
2251 unsigned long set, i;
2252 int fd;
2253
2254 j++;
2255 i = j * __NFDBITS;
2256 fdt = files_fdtable(files);
2257 if (i >= fdt->max_fds)
2258 break;
2259 set = fdt->open_fds->fds_bits[j];
2260 if (!set)
2261 continue;
2262 spin_unlock(&files->file_lock);
2263 for ( ; set ; i++, set >>= 1) {
2264 if (set & 1) {
2265 file = fget(i);
2266 if (!file)
2267 continue;
2268 if (file_has_perm(cred,
2269 file,
2270 file_to_av(file))) {
2271 sys_close(i);
2272 fd = get_unused_fd();
2273 if (fd != i) {
2274 if (fd >= 0)
2275 put_unused_fd(fd);
2276 fput(file);
2277 continue;
2278 }
2279 if (devnull) {
2280 get_file(devnull);
2281 } else {
2282 devnull = dentry_open(
2283 dget(selinux_null),
2284 mntget(selinuxfs_mount),
2285 O_RDWR, cred);
2286 if (IS_ERR(devnull)) {
2287 devnull = NULL;
2288 put_unused_fd(fd);
2289 fput(file);
2290 continue;
2291 }
2292 }
2293 fd_install(fd, devnull);
2294 }
2295 fput(file);
2296 }
2297 }
2298 spin_lock(&files->file_lock);
2299
2300 }
2301 spin_unlock(&files->file_lock);
2302 }
2303
2304 /*
2305 * Prepare a process for imminent new credential changes due to exec
2306 */
2307 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2308 {
2309 struct task_security_struct *new_tsec;
2310 struct rlimit *rlim, *initrlim;
2311 int rc, i;
2312
2313 new_tsec = bprm->cred->security;
2314 if (new_tsec->sid == new_tsec->osid)
2315 return;
2316
2317 /* Close files for which the new task SID is not authorized. */
2318 flush_unauthorized_files(bprm->cred, current->files);
2319
2320 /* Always clear parent death signal on SID transitions. */
2321 current->pdeath_signal = 0;
2322
2323 /* Check whether the new SID can inherit resource limits from the old
2324 * SID. If not, reset all soft limits to the lower of the current
2325 * task's hard limit and the init task's soft limit.
2326 *
2327 * Note that the setting of hard limits (even to lower them) can be
2328 * controlled by the setrlimit check. The inclusion of the init task's
2329 * soft limit into the computation is to avoid resetting soft limits
2330 * higher than the default soft limit for cases where the default is
2331 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2332 */
2333 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2334 PROCESS__RLIMITINH, NULL);
2335 if (rc) {
2336 for (i = 0; i < RLIM_NLIMITS; i++) {
2337 rlim = current->signal->rlim + i;
2338 initrlim = init_task.signal->rlim + i;
2339 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2340 }
2341 update_rlimit_cpu(current->signal->rlim[RLIMIT_CPU].rlim_cur);
2342 }
2343 }
2344
2345 /*
2346 * Clean up the process immediately after the installation of new credentials
2347 * due to exec
2348 */
2349 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2350 {
2351 const struct task_security_struct *tsec = current_security();
2352 struct itimerval itimer;
2353 u32 osid, sid;
2354 int rc, i;
2355
2356 osid = tsec->osid;
2357 sid = tsec->sid;
2358
2359 if (sid == osid)
2360 return;
2361
2362 /* Check whether the new SID can inherit signal state from the old SID.
2363 * If not, clear itimers to avoid subsequent signal generation and
2364 * flush and unblock signals.
2365 *
2366 * This must occur _after_ the task SID has been updated so that any
2367 * kill done after the flush will be checked against the new SID.
2368 */
2369 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2370 if (rc) {
2371 memset(&itimer, 0, sizeof itimer);
2372 for (i = 0; i < 3; i++)
2373 do_setitimer(i, &itimer, NULL);
2374 spin_lock_irq(&current->sighand->siglock);
2375 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
2376 __flush_signals(current);
2377 flush_signal_handlers(current, 1);
2378 sigemptyset(&current->blocked);
2379 }
2380 spin_unlock_irq(&current->sighand->siglock);
2381 }
2382
2383 /* Wake up the parent if it is waiting so that it can recheck
2384 * wait permission to the new task SID. */
2385 read_lock(&tasklist_lock);
2386 __wake_up_parent(current, current->real_parent);
2387 read_unlock(&tasklist_lock);
2388 }
2389
2390 /* superblock security operations */
2391
2392 static int selinux_sb_alloc_security(struct super_block *sb)
2393 {
2394 return superblock_alloc_security(sb);
2395 }
2396
2397 static void selinux_sb_free_security(struct super_block *sb)
2398 {
2399 superblock_free_security(sb);
2400 }
2401
2402 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2403 {
2404 if (plen > olen)
2405 return 0;
2406
2407 return !memcmp(prefix, option, plen);
2408 }
2409
2410 static inline int selinux_option(char *option, int len)
2411 {
2412 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2413 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2414 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2415 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2416 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
2417 }
2418
2419 static inline void take_option(char **to, char *from, int *first, int len)
2420 {
2421 if (!*first) {
2422 **to = ',';
2423 *to += 1;
2424 } else
2425 *first = 0;
2426 memcpy(*to, from, len);
2427 *to += len;
2428 }
2429
2430 static inline void take_selinux_option(char **to, char *from, int *first,
2431 int len)
2432 {
2433 int current_size = 0;
2434
2435 if (!*first) {
2436 **to = '|';
2437 *to += 1;
2438 } else
2439 *first = 0;
2440
2441 while (current_size < len) {
2442 if (*from != '"') {
2443 **to = *from;
2444 *to += 1;
2445 }
2446 from += 1;
2447 current_size += 1;
2448 }
2449 }
2450
2451 static int selinux_sb_copy_data(char *orig, char *copy)
2452 {
2453 int fnosec, fsec, rc = 0;
2454 char *in_save, *in_curr, *in_end;
2455 char *sec_curr, *nosec_save, *nosec;
2456 int open_quote = 0;
2457
2458 in_curr = orig;
2459 sec_curr = copy;
2460
2461 nosec = (char *)get_zeroed_page(GFP_KERNEL);
2462 if (!nosec) {
2463 rc = -ENOMEM;
2464 goto out;
2465 }
2466
2467 nosec_save = nosec;
2468 fnosec = fsec = 1;
2469 in_save = in_end = orig;
2470
2471 do {
2472 if (*in_end == '"')
2473 open_quote = !open_quote;
2474 if ((*in_end == ',' && open_quote == 0) ||
2475 *in_end == '\0') {
2476 int len = in_end - in_curr;
2477
2478 if (selinux_option(in_curr, len))
2479 take_selinux_option(&sec_curr, in_curr, &fsec, len);
2480 else
2481 take_option(&nosec, in_curr, &fnosec, len);
2482
2483 in_curr = in_end + 1;
2484 }
2485 } while (*in_end++);
2486
2487 strcpy(in_save, nosec_save);
2488 free_page((unsigned long)nosec_save);
2489 out:
2490 return rc;
2491 }
2492
2493 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
2494 {
2495 const struct cred *cred = current_cred();
2496 struct common_audit_data ad;
2497 int rc;
2498
2499 rc = superblock_doinit(sb, data);
2500 if (rc)
2501 return rc;
2502
2503 /* Allow all mounts performed by the kernel */
2504 if (flags & MS_KERNMOUNT)
2505 return 0;
2506
2507 COMMON_AUDIT_DATA_INIT(&ad, FS);
2508 ad.u.fs.path.dentry = sb->s_root;
2509 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2510 }
2511
2512 static int selinux_sb_statfs(struct dentry *dentry)
2513 {
2514 const struct cred *cred = current_cred();
2515 struct common_audit_data ad;
2516
2517 COMMON_AUDIT_DATA_INIT(&ad, FS);
2518 ad.u.fs.path.dentry = dentry->d_sb->s_root;
2519 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2520 }
2521
2522 static int selinux_mount(char *dev_name,
2523 struct path *path,
2524 char *type,
2525 unsigned long flags,
2526 void *data)
2527 {
2528 const struct cred *cred = current_cred();
2529
2530 if (flags & MS_REMOUNT)
2531 return superblock_has_perm(cred, path->mnt->mnt_sb,
2532 FILESYSTEM__REMOUNT, NULL);
2533 else
2534 return dentry_has_perm(cred, path->mnt, path->dentry,
2535 FILE__MOUNTON);
2536 }
2537
2538 static int selinux_umount(struct vfsmount *mnt, int flags)
2539 {
2540 const struct cred *cred = current_cred();
2541
2542 return superblock_has_perm(cred, mnt->mnt_sb,
2543 FILESYSTEM__UNMOUNT, NULL);
2544 }
2545
2546 /* inode security operations */
2547
2548 static int selinux_inode_alloc_security(struct inode *inode)
2549 {
2550 return inode_alloc_security(inode);
2551 }
2552
2553 static void selinux_inode_free_security(struct inode *inode)
2554 {
2555 inode_free_security(inode);
2556 }
2557
2558 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2559 char **name, void **value,
2560 size_t *len)
2561 {
2562 const struct cred *cred = current_cred();
2563 const struct task_security_struct *tsec = cred->security;
2564 struct inode_security_struct *dsec;
2565 struct superblock_security_struct *sbsec;
2566 u32 sid, newsid, clen;
2567 int rc;
2568 char *namep = NULL, *context;
2569
2570 dsec = dir->i_security;
2571 sbsec = dir->i_sb->s_security;
2572
2573 sid = tsec->sid;
2574 newsid = tsec->create_sid;
2575
2576 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
2577 rc = security_transition_sid(sid, dsec->sid,
2578 inode_mode_to_security_class(inode->i_mode),
2579 &newsid);
2580 if (rc) {
2581 printk(KERN_WARNING "%s: "
2582 "security_transition_sid failed, rc=%d (dev=%s "
2583 "ino=%ld)\n",
2584 __func__,
2585 -rc, inode->i_sb->s_id, inode->i_ino);
2586 return rc;
2587 }
2588 }
2589
2590 /* Possibly defer initialization to selinux_complete_init. */
2591 if (sbsec->flags & SE_SBINITIALIZED) {
2592 struct inode_security_struct *isec = inode->i_security;
2593 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2594 isec->sid = newsid;
2595 isec->initialized = 1;
2596 }
2597
2598 if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
2599 return -EOPNOTSUPP;
2600
2601 if (name) {
2602 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
2603 if (!namep)
2604 return -ENOMEM;
2605 *name = namep;
2606 }
2607
2608 if (value && len) {
2609 rc = security_sid_to_context_force(newsid, &context, &clen);
2610 if (rc) {
2611 kfree(namep);
2612 return rc;
2613 }
2614 *value = context;
2615 *len = clen;
2616 }
2617
2618 return 0;
2619 }
2620
2621 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2622 {
2623 return may_create(dir, dentry, SECCLASS_FILE);
2624 }
2625
2626 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2627 {
2628 return may_link(dir, old_dentry, MAY_LINK);
2629 }
2630
2631 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2632 {
2633 return may_link(dir, dentry, MAY_UNLINK);
2634 }
2635
2636 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2637 {
2638 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2639 }
2640
2641 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2642 {
2643 return may_create(dir, dentry, SECCLASS_DIR);
2644 }
2645
2646 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2647 {
2648 return may_link(dir, dentry, MAY_RMDIR);
2649 }
2650
2651 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2652 {
2653 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2654 }
2655
2656 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2657 struct inode *new_inode, struct dentry *new_dentry)
2658 {
2659 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2660 }
2661
2662 static int selinux_inode_readlink(struct dentry *dentry)
2663 {
2664 const struct cred *cred = current_cred();
2665
2666 return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2667 }
2668
2669 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2670 {
2671 const struct cred *cred = current_cred();
2672
2673 return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2674 }
2675
2676 static int selinux_inode_permission(struct inode *inode, int mask)
2677 {
2678 const struct cred *cred = current_cred();
2679
2680 if (!mask) {
2681 /* No permission to check. Existence test. */
2682 return 0;
2683 }
2684
2685 return inode_has_perm(cred, inode,
2686 file_mask_to_av(inode->i_mode, mask), NULL);
2687 }
2688
2689 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2690 {
2691 const struct cred *cred = current_cred();
2692 unsigned int ia_valid = iattr->ia_valid;
2693
2694 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2695 if (ia_valid & ATTR_FORCE) {
2696 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2697 ATTR_FORCE);
2698 if (!ia_valid)
2699 return 0;
2700 }
2701
2702 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2703 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2704 return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2705
2706 return dentry_has_perm(cred, NULL, dentry, FILE__WRITE);
2707 }
2708
2709 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2710 {
2711 const struct cred *cred = current_cred();
2712
2713 return dentry_has_perm(cred, mnt, dentry, FILE__GETATTR);
2714 }
2715
2716 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2717 {
2718 const struct cred *cred = current_cred();
2719
2720 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2721 sizeof XATTR_SECURITY_PREFIX - 1)) {
2722 if (!strcmp(name, XATTR_NAME_CAPS)) {
2723 if (!capable(CAP_SETFCAP))
2724 return -EPERM;
2725 } else if (!capable(CAP_SYS_ADMIN)) {
2726 /* A different attribute in the security namespace.
2727 Restrict to administrator. */
2728 return -EPERM;
2729 }
2730 }
2731
2732 /* Not an attribute we recognize, so just check the
2733 ordinary setattr permission. */
2734 return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2735 }
2736
2737 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2738 const void *value, size_t size, int flags)
2739 {
2740 struct inode *inode = dentry->d_inode;
2741 struct inode_security_struct *isec = inode->i_security;
2742 struct superblock_security_struct *sbsec;
2743 struct common_audit_data ad;
2744 u32 newsid, sid = current_sid();
2745 int rc = 0;
2746
2747 if (strcmp(name, XATTR_NAME_SELINUX))
2748 return selinux_inode_setotherxattr(dentry, name);
2749
2750 sbsec = inode->i_sb->s_security;
2751 if (!(sbsec->flags & SE_SBLABELSUPP))
2752 return -EOPNOTSUPP;
2753
2754 if (!is_owner_or_cap(inode))
2755 return -EPERM;
2756
2757 COMMON_AUDIT_DATA_INIT(&ad, FS);
2758 ad.u.fs.path.dentry = dentry;
2759
2760 rc = avc_has_perm(sid, isec->sid, isec->sclass,
2761 FILE__RELABELFROM, &ad);
2762 if (rc)
2763 return rc;
2764
2765 rc = security_context_to_sid(value, size, &newsid);
2766 if (rc == -EINVAL) {
2767 if (!capable(CAP_MAC_ADMIN))
2768 return rc;
2769 rc = security_context_to_sid_force(value, size, &newsid);
2770 }
2771 if (rc)
2772 return rc;
2773
2774 rc = avc_has_perm(sid, newsid, isec->sclass,
2775 FILE__RELABELTO, &ad);
2776 if (rc)
2777 return rc;
2778
2779 rc = security_validate_transition(isec->sid, newsid, sid,
2780 isec->sclass);
2781 if (rc)
2782 return rc;
2783
2784 return avc_has_perm(newsid,
2785 sbsec->sid,
2786 SECCLASS_FILESYSTEM,
2787 FILESYSTEM__ASSOCIATE,
2788 &ad);
2789 }
2790
2791 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2792 const void *value, size_t size,
2793 int flags)
2794 {
2795 struct inode *inode = dentry->d_inode;
2796 struct inode_security_struct *isec = inode->i_security;
2797 u32 newsid;
2798 int rc;
2799
2800 if (strcmp(name, XATTR_NAME_SELINUX)) {
2801 /* Not an attribute we recognize, so nothing to do. */
2802 return;
2803 }
2804
2805 rc = security_context_to_sid_force(value, size, &newsid);
2806 if (rc) {
2807 printk(KERN_ERR "SELinux: unable to map context to SID"
2808 "for (%s, %lu), rc=%d\n",
2809 inode->i_sb->s_id, inode->i_ino, -rc);
2810 return;
2811 }
2812
2813 isec->sid = newsid;
2814 return;
2815 }
2816
2817 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
2818 {
2819 const struct cred *cred = current_cred();
2820
2821 return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2822 }
2823
2824 static int selinux_inode_listxattr(struct dentry *dentry)
2825 {
2826 const struct cred *cred = current_cred();
2827
2828 return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2829 }
2830
2831 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
2832 {
2833 if (strcmp(name, XATTR_NAME_SELINUX))
2834 return selinux_inode_setotherxattr(dentry, name);
2835
2836 /* No one is allowed to remove a SELinux security label.
2837 You can change the label, but all data must be labeled. */
2838 return -EACCES;
2839 }
2840
2841 /*
2842 * Copy the inode security context value to the user.
2843 *
2844 * Permission check is handled by selinux_inode_getxattr hook.
2845 */
2846 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
2847 {
2848 u32 size;
2849 int error;
2850 char *context = NULL;
2851 struct inode_security_struct *isec = inode->i_security;
2852
2853 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2854 return -EOPNOTSUPP;
2855
2856 /*
2857 * If the caller has CAP_MAC_ADMIN, then get the raw context
2858 * value even if it is not defined by current policy; otherwise,
2859 * use the in-core value under current policy.
2860 * Use the non-auditing forms of the permission checks since
2861 * getxattr may be called by unprivileged processes commonly
2862 * and lack of permission just means that we fall back to the
2863 * in-core context value, not a denial.
2864 */
2865 error = selinux_capable(current, current_cred(), CAP_MAC_ADMIN,
2866 SECURITY_CAP_NOAUDIT);
2867 if (!error)
2868 error = security_sid_to_context_force(isec->sid, &context,
2869 &size);
2870 else
2871 error = security_sid_to_context(isec->sid, &context, &size);
2872 if (error)
2873 return error;
2874 error = size;
2875 if (alloc) {
2876 *buffer = context;
2877 goto out_nofree;
2878 }
2879 kfree(context);
2880 out_nofree:
2881 return error;
2882 }
2883
2884 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2885 const void *value, size_t size, int flags)
2886 {
2887 struct inode_security_struct *isec = inode->i_security;
2888 u32 newsid;
2889 int rc;
2890
2891 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2892 return -EOPNOTSUPP;
2893
2894 if (!value || !size)
2895 return -EACCES;
2896
2897 rc = security_context_to_sid((void *)value, size, &newsid);
2898 if (rc)
2899 return rc;
2900
2901 isec->sid = newsid;
2902 isec->initialized = 1;
2903 return 0;
2904 }
2905
2906 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2907 {
2908 const int len = sizeof(XATTR_NAME_SELINUX);
2909 if (buffer && len <= buffer_size)
2910 memcpy(buffer, XATTR_NAME_SELINUX, len);
2911 return len;
2912 }
2913
2914 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2915 {
2916 struct inode_security_struct *isec = inode->i_security;
2917 *secid = isec->sid;
2918 }
2919
2920 /* file security operations */
2921
2922 static int selinux_revalidate_file_permission(struct file *file, int mask)
2923 {
2924 const struct cred *cred = current_cred();
2925 struct inode *inode = file->f_path.dentry->d_inode;
2926
2927 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2928 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2929 mask |= MAY_APPEND;
2930
2931 return file_has_perm(cred, file,
2932 file_mask_to_av(inode->i_mode, mask));
2933 }
2934
2935 static int selinux_file_permission(struct file *file, int mask)
2936 {
2937 struct inode *inode = file->f_path.dentry->d_inode;
2938 struct file_security_struct *fsec = file->f_security;
2939 struct inode_security_struct *isec = inode->i_security;
2940 u32 sid = current_sid();
2941
2942 if (!mask)
2943 /* No permission to check. Existence test. */
2944 return 0;
2945
2946 if (sid == fsec->sid && fsec->isid == isec->sid &&
2947 fsec->pseqno == avc_policy_seqno())
2948 /* No change since dentry_open check. */
2949 return 0;
2950
2951 return selinux_revalidate_file_permission(file, mask);
2952 }
2953
2954 static int selinux_file_alloc_security(struct file *file)
2955 {
2956 return file_alloc_security(file);
2957 }
2958
2959 static void selinux_file_free_security(struct file *file)
2960 {
2961 file_free_security(file);
2962 }
2963
2964 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2965 unsigned long arg)
2966 {
2967 const struct cred *cred = current_cred();
2968 u32 av = 0;
2969
2970 if (_IOC_DIR(cmd) & _IOC_WRITE)
2971 av |= FILE__WRITE;
2972 if (_IOC_DIR(cmd) & _IOC_READ)
2973 av |= FILE__READ;
2974 if (!av)
2975 av = FILE__IOCTL;
2976
2977 return file_has_perm(cred, file, av);
2978 }
2979
2980 static int default_noexec;
2981
2982 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2983 {
2984 const struct cred *cred = current_cred();
2985 int rc = 0;
2986
2987 if (default_noexec &&
2988 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2989 /*
2990 * We are making executable an anonymous mapping or a
2991 * private file mapping that will also be writable.
2992 * This has an additional check.
2993 */
2994 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
2995 if (rc)
2996 goto error;
2997 }
2998
2999 if (file) {
3000 /* read access is always possible with a mapping */
3001 u32 av = FILE__READ;
3002
3003 /* write access only matters if the mapping is shared */
3004 if (shared && (prot & PROT_WRITE))
3005 av |= FILE__WRITE;
3006
3007 if (prot & PROT_EXEC)
3008 av |= FILE__EXECUTE;
3009
3010 return file_has_perm(cred, file, av);
3011 }
3012
3013 error:
3014 return rc;
3015 }
3016
3017 static int selinux_file_mmap(struct file *file, unsigned long reqprot,
3018 unsigned long prot, unsigned long flags,
3019 unsigned long addr, unsigned long addr_only)
3020 {
3021 int rc = 0;
3022 u32 sid = current_sid();
3023
3024 /*
3025 * notice that we are intentionally putting the SELinux check before
3026 * the secondary cap_file_mmap check. This is such a likely attempt
3027 * at bad behaviour/exploit that we always want to get the AVC, even
3028 * if DAC would have also denied the operation.
3029 */
3030 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3031 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3032 MEMPROTECT__MMAP_ZERO, NULL);
3033 if (rc)
3034 return rc;
3035 }
3036
3037 /* do DAC check on address space usage */
3038 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
3039 if (rc || addr_only)
3040 return rc;
3041
3042 if (selinux_checkreqprot)
3043 prot = reqprot;
3044
3045 return file_map_prot_check(file, prot,
3046 (flags & MAP_TYPE) == MAP_SHARED);
3047 }
3048
3049 static int selinux_file_mprotect(struct vm_area_struct *vma,
3050 unsigned long reqprot,
3051 unsigned long prot)
3052 {
3053 const struct cred *cred = current_cred();
3054
3055 if (selinux_checkreqprot)
3056 prot = reqprot;
3057
3058 if (default_noexec &&
3059 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3060 int rc = 0;
3061 if (vma->vm_start >= vma->vm_mm->start_brk &&
3062 vma->vm_end <= vma->vm_mm->brk) {
3063 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3064 } else if (!vma->vm_file &&
3065 vma->vm_start <= vma->vm_mm->start_stack &&
3066 vma->vm_end >= vma->vm_mm->start_stack) {
3067 rc = current_has_perm(current, PROCESS__EXECSTACK);
3068 } else if (vma->vm_file && vma->anon_vma) {
3069 /*
3070 * We are making executable a file mapping that has
3071 * had some COW done. Since pages might have been
3072 * written, check ability to execute the possibly
3073 * modified content. This typically should only
3074 * occur for text relocations.
3075 */
3076 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3077 }
3078 if (rc)
3079 return rc;
3080 }
3081
3082 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3083 }
3084
3085 static int selinux_file_lock(struct file *file, unsigned int cmd)
3086 {
3087 const struct cred *cred = current_cred();
3088
3089 return file_has_perm(cred, file, FILE__LOCK);
3090 }
3091
3092 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3093 unsigned long arg)
3094 {
3095 const struct cred *cred = current_cred();
3096 int err = 0;
3097
3098 switch (cmd) {
3099 case F_SETFL:
3100 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3101 err = -EINVAL;
3102 break;
3103 }
3104
3105 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3106 err = file_has_perm(cred, file, FILE__WRITE);
3107 break;
3108 }
3109 /* fall through */
3110 case F_SETOWN:
3111 case F_SETSIG:
3112 case F_GETFL:
3113 case F_GETOWN:
3114 case F_GETSIG:
3115 /* Just check FD__USE permission */
3116 err = file_has_perm(cred, file, 0);
3117 break;
3118 case F_GETLK:
3119 case F_SETLK:
3120 case F_SETLKW:
3121 #if BITS_PER_LONG == 32
3122 case F_GETLK64:
3123 case F_SETLK64:
3124 case F_SETLKW64:
3125 #endif
3126 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3127 err = -EINVAL;
3128 break;
3129 }
3130 err = file_has_perm(cred, file, FILE__LOCK);
3131 break;
3132 }
3133
3134 return err;
3135 }
3136
3137 static int selinux_file_set_fowner(struct file *file)
3138 {
3139 struct file_security_struct *fsec;
3140
3141 fsec = file->f_security;
3142 fsec->fown_sid = current_sid();
3143
3144 return 0;
3145 }
3146
3147 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3148 struct fown_struct *fown, int signum)
3149 {
3150 struct file *file;
3151 u32 sid = task_sid(tsk);
3152 u32 perm;
3153 struct file_security_struct *fsec;
3154
3155 /* struct fown_struct is never outside the context of a struct file */
3156 file = container_of(fown, struct file, f_owner);
3157
3158 fsec = file->f_security;
3159
3160 if (!signum)
3161 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3162 else
3163 perm = signal_to_av(signum);
3164
3165 return avc_has_perm(fsec->fown_sid, sid,
3166 SECCLASS_PROCESS, perm, NULL);
3167 }
3168
3169 static int selinux_file_receive(struct file *file)
3170 {
3171 const struct cred *cred = current_cred();
3172
3173 return file_has_perm(cred, file, file_to_av(file));
3174 }
3175
3176 static int selinux_dentry_open(struct file *file, const struct cred *cred)
3177 {
3178 struct file_security_struct *fsec;
3179 struct inode *inode;
3180 struct inode_security_struct *isec;
3181
3182 inode = file->f_path.dentry->d_inode;
3183 fsec = file->f_security;
3184 isec = inode->i_security;
3185 /*
3186 * Save inode label and policy sequence number
3187 * at open-time so that selinux_file_permission
3188 * can determine whether revalidation is necessary.
3189 * Task label is already saved in the file security
3190 * struct as its SID.
3191 */
3192 fsec->isid = isec->sid;
3193 fsec->pseqno = avc_policy_seqno();
3194 /*
3195 * Since the inode label or policy seqno may have changed
3196 * between the selinux_inode_permission check and the saving
3197 * of state above, recheck that access is still permitted.
3198 * Otherwise, access might never be revalidated against the
3199 * new inode label or new policy.
3200 * This check is not redundant - do not remove.
3201 */
3202 return inode_has_perm(cred, inode, open_file_to_av(file), NULL);
3203 }
3204
3205 /* task security operations */
3206
3207 static int selinux_task_create(unsigned long clone_flags)
3208 {
3209 return current_has_perm(current, PROCESS__FORK);
3210 }
3211
3212 /*
3213 * allocate the SELinux part of blank credentials
3214 */
3215 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3216 {
3217 struct task_security_struct *tsec;
3218
3219 tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3220 if (!tsec)
3221 return -ENOMEM;
3222
3223 cred->security = tsec;
3224 return 0;
3225 }
3226
3227 /*
3228 * detach and free the LSM part of a set of credentials
3229 */
3230 static void selinux_cred_free(struct cred *cred)
3231 {
3232 struct task_security_struct *tsec = cred->security;
3233
3234 BUG_ON((unsigned long) cred->security < PAGE_SIZE);
3235 cred->security = (void *) 0x7UL;
3236 kfree(tsec);
3237 }
3238
3239 /*
3240 * prepare a new set of credentials for modification
3241 */
3242 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3243 gfp_t gfp)
3244 {
3245 const struct task_security_struct *old_tsec;
3246 struct task_security_struct *tsec;
3247
3248 old_tsec = old->security;
3249
3250 tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3251 if (!tsec)
3252 return -ENOMEM;
3253
3254 new->security = tsec;
3255 return 0;
3256 }
3257
3258 /*
3259 * transfer the SELinux data to a blank set of creds
3260 */
3261 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3262 {
3263 const struct task_security_struct *old_tsec = old->security;
3264 struct task_security_struct *tsec = new->security;
3265
3266 *tsec = *old_tsec;
3267 }
3268
3269 /*
3270 * set the security data for a kernel service
3271 * - all the creation contexts are set to unlabelled
3272 */
3273 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3274 {
3275 struct task_security_struct *tsec = new->security;
3276 u32 sid = current_sid();
3277 int ret;
3278
3279 ret = avc_has_perm(sid, secid,
3280 SECCLASS_KERNEL_SERVICE,
3281 KERNEL_SERVICE__USE_AS_OVERRIDE,
3282 NULL);
3283 if (ret == 0) {
3284 tsec->sid = secid;
3285 tsec->create_sid = 0;
3286 tsec->keycreate_sid = 0;
3287 tsec->sockcreate_sid = 0;
3288 }
3289 return ret;
3290 }
3291
3292 /*
3293 * set the file creation context in a security record to the same as the
3294 * objective context of the specified inode
3295 */
3296 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3297 {
3298 struct inode_security_struct *isec = inode->i_security;
3299 struct task_security_struct *tsec = new->security;
3300 u32 sid = current_sid();
3301 int ret;
3302
3303 ret = avc_has_perm(sid, isec->sid,
3304 SECCLASS_KERNEL_SERVICE,
3305 KERNEL_SERVICE__CREATE_FILES_AS,
3306 NULL);
3307
3308 if (ret == 0)
3309 tsec->create_sid = isec->sid;
3310 return ret;
3311 }
3312
3313 static int selinux_kernel_module_request(char *kmod_name)
3314 {
3315 u32 sid;
3316 struct common_audit_data ad;
3317
3318 sid = task_sid(current);
3319
3320 COMMON_AUDIT_DATA_INIT(&ad, KMOD);
3321 ad.u.kmod_name = kmod_name;
3322
3323 return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
3324 SYSTEM__MODULE_REQUEST, &ad);
3325 }
3326
3327 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3328 {
3329 return current_has_perm(p, PROCESS__SETPGID);
3330 }
3331
3332 static int selinux_task_getpgid(struct task_struct *p)
3333 {
3334 return current_has_perm(p, PROCESS__GETPGID);
3335 }
3336
3337 static int selinux_task_getsid(struct task_struct *p)
3338 {
3339 return current_has_perm(p, PROCESS__GETSESSION);
3340 }
3341
3342 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3343 {
3344 *secid = task_sid(p);
3345 }
3346
3347 static int selinux_task_setnice(struct task_struct *p, int nice)
3348 {
3349 int rc;
3350
3351 rc = cap_task_setnice(p, nice);
3352 if (rc)
3353 return rc;
3354
3355 return current_has_perm(p, PROCESS__SETSCHED);
3356 }
3357
3358 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3359 {
3360 int rc;
3361
3362 rc = cap_task_setioprio(p, ioprio);
3363 if (rc)
3364 return rc;
3365
3366 return current_has_perm(p, PROCESS__SETSCHED);
3367 }
3368
3369 static int selinux_task_getioprio(struct task_struct *p)
3370 {
3371 return current_has_perm(p, PROCESS__GETSCHED);
3372 }
3373
3374 static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
3375 {
3376 struct rlimit *old_rlim = current->signal->rlim + resource;
3377
3378 /* Control the ability to change the hard limit (whether
3379 lowering or raising it), so that the hard limit can
3380 later be used as a safe reset point for the soft limit
3381 upon context transitions. See selinux_bprm_committing_creds. */
3382 if (old_rlim->rlim_max != new_rlim->rlim_max)
3383 return current_has_perm(current, PROCESS__SETRLIMIT);
3384
3385 return 0;
3386 }
3387
3388 static int selinux_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp)
3389 {
3390 int rc;
3391
3392 rc = cap_task_setscheduler(p, policy, lp);
3393 if (rc)
3394 return rc;
3395
3396 return current_has_perm(p, PROCESS__SETSCHED);
3397 }
3398
3399 static int selinux_task_getscheduler(struct task_struct *p)
3400 {
3401 return current_has_perm(p, PROCESS__GETSCHED);
3402 }
3403
3404 static int selinux_task_movememory(struct task_struct *p)
3405 {
3406 return current_has_perm(p, PROCESS__SETSCHED);
3407 }
3408
3409 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3410 int sig, u32 secid)
3411 {
3412 u32 perm;
3413 int rc;
3414
3415 if (!sig)
3416 perm = PROCESS__SIGNULL; /* null signal; existence test */
3417 else
3418 perm = signal_to_av(sig);
3419 if (secid)
3420 rc = avc_has_perm(secid, task_sid(p),
3421 SECCLASS_PROCESS, perm, NULL);
3422 else
3423 rc = current_has_perm(p, perm);
3424 return rc;
3425 }
3426
3427 static int selinux_task_wait(struct task_struct *p)
3428 {
3429 return task_has_perm(p, current, PROCESS__SIGCHLD);
3430 }
3431
3432 static void selinux_task_to_inode(struct task_struct *p,
3433 struct inode *inode)
3434 {
3435 struct inode_security_struct *isec = inode->i_security;
3436 u32 sid = task_sid(p);
3437
3438 isec->sid = sid;
3439 isec->initialized = 1;
3440 }
3441
3442 /* Returns error only if unable to parse addresses */
3443 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3444 struct common_audit_data *ad, u8 *proto)
3445 {
3446 int offset, ihlen, ret = -EINVAL;
3447 struct iphdr _iph, *ih;
3448
3449 offset = skb_network_offset(skb);
3450 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3451 if (ih == NULL)
3452 goto out;
3453
3454 ihlen = ih->ihl * 4;
3455 if (ihlen < sizeof(_iph))
3456 goto out;
3457
3458 ad->u.net.v4info.saddr = ih->saddr;
3459 ad->u.net.v4info.daddr = ih->daddr;
3460 ret = 0;
3461
3462 if (proto)
3463 *proto = ih->protocol;
3464
3465 switch (ih->protocol) {
3466 case IPPROTO_TCP: {
3467 struct tcphdr _tcph, *th;
3468
3469 if (ntohs(ih->frag_off) & IP_OFFSET)
3470 break;
3471
3472 offset += ihlen;
3473 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3474 if (th == NULL)
3475 break;
3476
3477 ad->u.net.sport = th->source;
3478 ad->u.net.dport = th->dest;
3479 break;
3480 }
3481
3482 case IPPROTO_UDP: {
3483 struct udphdr _udph, *uh;
3484
3485 if (ntohs(ih->frag_off) & IP_OFFSET)
3486 break;
3487
3488 offset += ihlen;
3489 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3490 if (uh == NULL)
3491 break;
3492
3493 ad->u.net.sport = uh->source;
3494 ad->u.net.dport = uh->dest;
3495 break;
3496 }
3497
3498 case IPPROTO_DCCP: {
3499 struct dccp_hdr _dccph, *dh;
3500
3501 if (ntohs(ih->frag_off) & IP_OFFSET)
3502 break;
3503
3504 offset += ihlen;
3505 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3506 if (dh == NULL)
3507 break;
3508
3509 ad->u.net.sport = dh->dccph_sport;
3510 ad->u.net.dport = dh->dccph_dport;
3511 break;
3512 }
3513
3514 default:
3515 break;
3516 }
3517 out:
3518 return ret;
3519 }
3520
3521 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3522
3523 /* Returns error only if unable to parse addresses */
3524 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3525 struct common_audit_data *ad, u8 *proto)
3526 {
3527 u8 nexthdr;
3528 int ret = -EINVAL, offset;
3529 struct ipv6hdr _ipv6h, *ip6;
3530
3531 offset = skb_network_offset(skb);
3532 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3533 if (ip6 == NULL)
3534 goto out;
3535
3536 ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr);
3537 ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr);
3538 ret = 0;
3539
3540 nexthdr = ip6->nexthdr;
3541 offset += sizeof(_ipv6h);
3542 offset = ipv6_skip_exthdr(skb, offset, &nexthdr);
3543 if (offset < 0)
3544 goto out;
3545
3546 if (proto)
3547 *proto = nexthdr;
3548
3549 switch (nexthdr) {
3550 case IPPROTO_TCP: {
3551 struct tcphdr _tcph, *th;
3552
3553 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3554 if (th == NULL)
3555 break;
3556
3557 ad->u.net.sport = th->source;
3558 ad->u.net.dport = th->dest;
3559 break;
3560 }
3561
3562 case IPPROTO_UDP: {
3563 struct udphdr _udph, *uh;
3564
3565 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3566 if (uh == NULL)
3567 break;
3568
3569 ad->u.net.sport = uh->source;
3570 ad->u.net.dport = uh->dest;
3571 break;
3572 }
3573
3574 case IPPROTO_DCCP: {
3575 struct dccp_hdr _dccph, *dh;
3576
3577 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3578 if (dh == NULL)
3579 break;
3580
3581 ad->u.net.sport = dh->dccph_sport;
3582 ad->u.net.dport = dh->dccph_dport;
3583 break;
3584 }
3585
3586 /* includes fragments */
3587 default:
3588 break;
3589 }
3590 out:
3591 return ret;
3592 }
3593
3594 #endif /* IPV6 */
3595
3596 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3597 char **_addrp, int src, u8 *proto)
3598 {
3599 char *addrp;
3600 int ret;
3601
3602 switch (ad->u.net.family) {
3603 case PF_INET:
3604 ret = selinux_parse_skb_ipv4(skb, ad, proto);
3605 if (ret)
3606 goto parse_error;
3607 addrp = (char *)(src ? &ad->u.net.v4info.saddr :
3608 &ad->u.net.v4info.daddr);
3609 goto okay;
3610
3611 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3612 case PF_INET6:
3613 ret = selinux_parse_skb_ipv6(skb, ad, proto);
3614 if (ret)
3615 goto parse_error;
3616 addrp = (char *)(src ? &ad->u.net.v6info.saddr :
3617 &ad->u.net.v6info.daddr);
3618 goto okay;
3619 #endif /* IPV6 */
3620 default:
3621 addrp = NULL;
3622 goto okay;
3623 }
3624
3625 parse_error:
3626 printk(KERN_WARNING
3627 "SELinux: failure in selinux_parse_skb(),"
3628 " unable to parse packet\n");
3629 return ret;
3630
3631 okay:
3632 if (_addrp)
3633 *_addrp = addrp;
3634 return 0;
3635 }
3636
3637 /**
3638 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3639 * @skb: the packet
3640 * @family: protocol family
3641 * @sid: the packet's peer label SID
3642 *
3643 * Description:
3644 * Check the various different forms of network peer labeling and determine
3645 * the peer label/SID for the packet; most of the magic actually occurs in
3646 * the security server function security_net_peersid_cmp(). The function
3647 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
3648 * or -EACCES if @sid is invalid due to inconsistencies with the different
3649 * peer labels.
3650 *
3651 */
3652 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3653 {
3654 int err;
3655 u32 xfrm_sid;
3656 u32 nlbl_sid;
3657 u32 nlbl_type;
3658
3659 selinux_skb_xfrm_sid(skb, &xfrm_sid);
3660 selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3661
3662 err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
3663 if (unlikely(err)) {
3664 printk(KERN_WARNING
3665 "SELinux: failure in selinux_skb_peerlbl_sid(),"
3666 " unable to determine packet's peer label\n");
3667 return -EACCES;
3668 }
3669
3670 return 0;
3671 }
3672
3673 /* socket security operations */
3674 static int socket_has_perm(struct task_struct *task, struct socket *sock,
3675 u32 perms)
3676 {
3677 struct inode_security_struct *isec;
3678 struct common_audit_data ad;
3679 u32 sid;
3680 int err = 0;
3681
3682 isec = SOCK_INODE(sock)->i_security;
3683
3684 if (isec->sid == SECINITSID_KERNEL)
3685 goto out;
3686 sid = task_sid(task);
3687
3688 COMMON_AUDIT_DATA_INIT(&ad, NET);
3689 ad.u.net.sk = sock->sk;
3690 err = avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
3691
3692 out:
3693 return err;
3694 }
3695
3696 static int selinux_socket_create(int family, int type,
3697 int protocol, int kern)
3698 {
3699 const struct cred *cred = current_cred();
3700 const struct task_security_struct *tsec = cred->security;
3701 u32 sid, newsid;
3702 u16 secclass;
3703 int err = 0;
3704
3705 if (kern)
3706 goto out;
3707
3708 sid = tsec->sid;
3709 newsid = tsec->sockcreate_sid ?: sid;
3710
3711 secclass = socket_type_to_security_class(family, type, protocol);
3712 err = avc_has_perm(sid, newsid, secclass, SOCKET__CREATE, NULL);
3713
3714 out:
3715 return err;
3716 }
3717
3718 static int selinux_socket_post_create(struct socket *sock, int family,
3719 int type, int protocol, int kern)
3720 {
3721 const struct cred *cred = current_cred();
3722 const struct task_security_struct *tsec = cred->security;
3723 struct inode_security_struct *isec;
3724 struct sk_security_struct *sksec;
3725 u32 sid, newsid;
3726 int err = 0;
3727
3728 sid = tsec->sid;
3729 newsid = tsec->sockcreate_sid;
3730
3731 isec = SOCK_INODE(sock)->i_security;
3732
3733 if (kern)
3734 isec->sid = SECINITSID_KERNEL;
3735 else if (newsid)
3736 isec->sid = newsid;
3737 else
3738 isec->sid = sid;
3739
3740 isec->sclass = socket_type_to_security_class(family, type, protocol);
3741 isec->initialized = 1;
3742
3743 if (sock->sk) {
3744 sksec = sock->sk->sk_security;
3745 sksec->sid = isec->sid;
3746 sksec->sclass = isec->sclass;
3747 err = selinux_netlbl_socket_post_create(sock->sk, family);
3748 }
3749
3750 return err;
3751 }
3752
3753 /* Range of port numbers used to automatically bind.
3754 Need to determine whether we should perform a name_bind
3755 permission check between the socket and the port number. */
3756
3757 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
3758 {
3759 u16 family;
3760 int err;
3761
3762 err = socket_has_perm(current, sock, SOCKET__BIND);
3763 if (err)
3764 goto out;
3765
3766 /*
3767 * If PF_INET or PF_INET6, check name_bind permission for the port.
3768 * Multiple address binding for SCTP is not supported yet: we just
3769 * check the first address now.
3770 */
3771 family = sock->sk->sk_family;
3772 if (family == PF_INET || family == PF_INET6) {
3773 char *addrp;
3774 struct inode_security_struct *isec;
3775 struct common_audit_data ad;
3776 struct sockaddr_in *addr4 = NULL;
3777 struct sockaddr_in6 *addr6 = NULL;
3778 unsigned short snum;
3779 struct sock *sk = sock->sk;
3780 u32 sid, node_perm;
3781
3782 isec = SOCK_INODE(sock)->i_security;
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(isec->sid, sid,
3808 isec->sclass,
3809 SOCKET__NAME_BIND, &ad);
3810 if (err)
3811 goto out;
3812 }
3813 }
3814
3815 switch (isec->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(isec->sid, sid,
3847 isec->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 inode_security_struct *isec;
3859 int err;
3860
3861 err = socket_has_perm(current, sock, 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 isec = SOCK_INODE(sock)->i_security;
3869 if (isec->sclass == SECCLASS_TCP_SOCKET ||
3870 isec->sclass == SECCLASS_DCCP_SOCKET) {
3871 struct common_audit_data ad;
3872 struct sockaddr_in *addr4 = NULL;
3873 struct sockaddr_in6 *addr6 = NULL;
3874 unsigned short snum;
3875 u32 sid, perm;
3876
3877 if (sk->sk_family == PF_INET) {
3878 addr4 = (struct sockaddr_in *)address;
3879 if (addrlen < sizeof(struct sockaddr_in))
3880 return -EINVAL;
3881 snum = ntohs(addr4->sin_port);
3882 } else {
3883 addr6 = (struct sockaddr_in6 *)address;
3884 if (addrlen < SIN6_LEN_RFC2133)
3885 return -EINVAL;
3886 snum = ntohs(addr6->sin6_port);
3887 }
3888
3889 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
3890 if (err)
3891 goto out;
3892
3893 perm = (isec->sclass == SECCLASS_TCP_SOCKET) ?
3894 TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
3895
3896 COMMON_AUDIT_DATA_INIT(&ad, NET);
3897 ad.u.net.dport = htons(snum);
3898 ad.u.net.family = sk->sk_family;
3899 err = avc_has_perm(isec->sid, sid, isec->sclass, perm, &ad);
3900 if (err)
3901 goto out;
3902 }
3903
3904 err = selinux_netlbl_socket_connect(sk, address);
3905
3906 out:
3907 return err;
3908 }
3909
3910 static int selinux_socket_listen(struct socket *sock, int backlog)
3911 {
3912 return socket_has_perm(current, sock, SOCKET__LISTEN);
3913 }
3914
3915 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
3916 {
3917 int err;
3918 struct inode_security_struct *isec;
3919 struct inode_security_struct *newisec;
3920
3921 err = socket_has_perm(current, sock, SOCKET__ACCEPT);
3922 if (err)
3923 return err;
3924
3925 newisec = SOCK_INODE(newsock)->i_security;
3926
3927 isec = SOCK_INODE(sock)->i_security;
3928 newisec->sclass = isec->sclass;
3929 newisec->sid = isec->sid;
3930 newisec->initialized = 1;
3931
3932 return 0;
3933 }
3934
3935 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3936 int size)
3937 {
3938 return socket_has_perm(current, sock, SOCKET__WRITE);
3939 }
3940
3941 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
3942 int size, int flags)
3943 {
3944 return socket_has_perm(current, sock, SOCKET__READ);
3945 }
3946
3947 static int selinux_socket_getsockname(struct socket *sock)
3948 {
3949 return socket_has_perm(current, sock, SOCKET__GETATTR);
3950 }
3951
3952 static int selinux_socket_getpeername(struct socket *sock)
3953 {
3954 return socket_has_perm(current, sock, SOCKET__GETATTR);
3955 }
3956
3957 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
3958 {
3959 int err;
3960
3961 err = socket_has_perm(current, sock, SOCKET__SETOPT);
3962 if (err)
3963 return err;
3964
3965 return selinux_netlbl_socket_setsockopt(sock, level, optname);
3966 }
3967
3968 static int selinux_socket_getsockopt(struct socket *sock, int level,
3969 int optname)
3970 {
3971 return socket_has_perm(current, sock, SOCKET__GETOPT);
3972 }
3973
3974 static int selinux_socket_shutdown(struct socket *sock, int how)
3975 {
3976 return socket_has_perm(current, sock, SOCKET__SHUTDOWN);
3977 }
3978
3979 static int selinux_socket_unix_stream_connect(struct socket *sock,
3980 struct socket *other,
3981 struct sock *newsk)
3982 {
3983 struct sk_security_struct *sksec_sock = sock->sk->sk_security;
3984 struct sk_security_struct *sksec_other = other->sk->sk_security;
3985 struct sk_security_struct *sksec_new = newsk->sk_security;
3986 struct common_audit_data ad;
3987 int err;
3988
3989 COMMON_AUDIT_DATA_INIT(&ad, NET);
3990 ad.u.net.sk = other->sk;
3991
3992 err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
3993 sksec_other->sclass,
3994 UNIX_STREAM_SOCKET__CONNECTTO, &ad);
3995 if (err)
3996 return err;
3997
3998 /* server child socket */
3999 sksec_new->peer_sid = sksec_sock->sid;
4000 err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
4001 &sksec_new->sid);
4002 if (err)
4003 return err;
4004
4005 /* connecting socket */
4006 sksec_sock->peer_sid = sksec_new->sid;
4007
4008 return 0;
4009 }
4010
4011 static int selinux_socket_unix_may_send(struct socket *sock,
4012 struct socket *other)
4013 {
4014 struct inode_security_struct *isec;
4015 struct inode_security_struct *other_isec;
4016 struct common_audit_data ad;
4017 int err;
4018
4019 isec = SOCK_INODE(sock)->i_security;
4020 other_isec = SOCK_INODE(other)->i_security;
4021
4022 COMMON_AUDIT_DATA_INIT(&ad, NET);
4023 ad.u.net.sk = other->sk;
4024
4025 err = avc_has_perm(isec->sid, other_isec->sid,
4026 isec->sclass, SOCKET__SENDTO, &ad);
4027 if (err)
4028 return err;
4029
4030 return 0;
4031 }
4032
4033 static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
4034 u32 peer_sid,
4035 struct common_audit_data *ad)
4036 {
4037 int err;
4038 u32 if_sid;
4039 u32 node_sid;
4040
4041 err = sel_netif_sid(ifindex, &if_sid);
4042 if (err)
4043 return err;
4044 err = avc_has_perm(peer_sid, if_sid,
4045 SECCLASS_NETIF, NETIF__INGRESS, ad);
4046 if (err)
4047 return err;
4048
4049 err = sel_netnode_sid(addrp, family, &node_sid);
4050 if (err)
4051 return err;
4052 return avc_has_perm(peer_sid, node_sid,
4053 SECCLASS_NODE, NODE__RECVFROM, ad);
4054 }
4055
4056 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4057 u16 family)
4058 {
4059 int err = 0;
4060 struct sk_security_struct *sksec = sk->sk_security;
4061 u32 peer_sid;
4062 u32 sk_sid = sksec->sid;
4063 struct common_audit_data ad;
4064 char *addrp;
4065
4066 COMMON_AUDIT_DATA_INIT(&ad, NET);
4067 ad.u.net.netif = skb->skb_iif;
4068 ad.u.net.family = family;
4069 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4070 if (err)
4071 return err;
4072
4073 if (selinux_secmark_enabled()) {
4074 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4075 PACKET__RECV, &ad);
4076 if (err)
4077 return err;
4078 }
4079
4080 if (selinux_policycap_netpeer) {
4081 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4082 if (err)
4083 return err;
4084 err = avc_has_perm(sk_sid, peer_sid,
4085 SECCLASS_PEER, PEER__RECV, &ad);
4086 if (err)
4087 selinux_netlbl_err(skb, err, 0);
4088 } else {
4089 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4090 if (err)
4091 return err;
4092 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4093 }
4094
4095 return err;
4096 }
4097
4098 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4099 {
4100 int err;
4101 struct sk_security_struct *sksec = sk->sk_security;
4102 u16 family = sk->sk_family;
4103 u32 sk_sid = sksec->sid;
4104 struct common_audit_data ad;
4105 char *addrp;
4106 u8 secmark_active;
4107 u8 peerlbl_active;
4108
4109 if (family != PF_INET && family != PF_INET6)
4110 return 0;
4111
4112 /* Handle mapped IPv4 packets arriving via IPv6 sockets */
4113 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4114 family = PF_INET;
4115
4116 /* If any sort of compatibility mode is enabled then handoff processing
4117 * to the selinux_sock_rcv_skb_compat() function to deal with the
4118 * special handling. We do this in an attempt to keep this function
4119 * as fast and as clean as possible. */
4120 if (!selinux_policycap_netpeer)
4121 return selinux_sock_rcv_skb_compat(sk, skb, family);
4122
4123 secmark_active = selinux_secmark_enabled();
4124 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4125 if (!secmark_active && !peerlbl_active)
4126 return 0;
4127
4128 COMMON_AUDIT_DATA_INIT(&ad, NET);
4129 ad.u.net.netif = skb->skb_iif;
4130 ad.u.net.family = family;
4131 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4132 if (err)
4133 return err;
4134
4135 if (peerlbl_active) {
4136 u32 peer_sid;
4137
4138 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4139 if (err)
4140 return err;
4141 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
4142 peer_sid, &ad);
4143 if (err) {
4144 selinux_netlbl_err(skb, err, 0);
4145 return err;
4146 }
4147 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4148 PEER__RECV, &ad);
4149 if (err)
4150 selinux_netlbl_err(skb, err, 0);
4151 }
4152
4153 if (secmark_active) {
4154 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4155 PACKET__RECV, &ad);
4156 if (err)
4157 return err;
4158 }
4159
4160 return err;
4161 }
4162
4163 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4164 int __user *optlen, unsigned len)
4165 {
4166 int err = 0;
4167 char *scontext;
4168 u32 scontext_len;
4169 struct sk_security_struct *sksec;
4170 struct inode_security_struct *isec;
4171 u32 peer_sid = SECSID_NULL;
4172
4173 isec = SOCK_INODE(sock)->i_security;
4174
4175 if (isec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4176 isec->sclass == SECCLASS_TCP_SOCKET) {
4177 sksec = sock->sk->sk_security;
4178 peer_sid = sksec->peer_sid;
4179 }
4180 if (peer_sid == SECSID_NULL) {
4181 err = -ENOPROTOOPT;
4182 goto out;
4183 }
4184
4185 err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4186
4187 if (err)
4188 goto out;
4189
4190 if (scontext_len > len) {
4191 err = -ERANGE;
4192 goto out_len;
4193 }
4194
4195 if (copy_to_user(optval, scontext, scontext_len))
4196 err = -EFAULT;
4197
4198 out_len:
4199 if (put_user(scontext_len, optlen))
4200 err = -EFAULT;
4201
4202 kfree(scontext);
4203 out:
4204 return err;
4205 }
4206
4207 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4208 {
4209 u32 peer_secid = SECSID_NULL;
4210 u16 family;
4211
4212 if (skb && skb->protocol == htons(ETH_P_IP))
4213 family = PF_INET;
4214 else if (skb && skb->protocol == htons(ETH_P_IPV6))
4215 family = PF_INET6;
4216 else if (sock)
4217 family = sock->sk->sk_family;
4218 else
4219 goto out;
4220
4221 if (sock && family == PF_UNIX)
4222 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4223 else if (skb)
4224 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4225
4226 out:
4227 *secid = peer_secid;
4228 if (peer_secid == SECSID_NULL)
4229 return -EINVAL;
4230 return 0;
4231 }
4232
4233 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4234 {
4235 return sk_alloc_security(sk, family, priority);
4236 }
4237
4238 static void selinux_sk_free_security(struct sock *sk)
4239 {
4240 sk_free_security(sk);
4241 }
4242
4243 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4244 {
4245 struct sk_security_struct *sksec = sk->sk_security;
4246 struct sk_security_struct *newsksec = newsk->sk_security;
4247
4248 newsksec->sid = sksec->sid;
4249 newsksec->peer_sid = sksec->peer_sid;
4250 newsksec->sclass = sksec->sclass;
4251
4252 selinux_netlbl_sk_security_reset(newsksec);
4253 }
4254
4255 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4256 {
4257 if (!sk)
4258 *secid = SECINITSID_ANY_SOCKET;
4259 else {
4260 struct sk_security_struct *sksec = sk->sk_security;
4261
4262 *secid = sksec->sid;
4263 }
4264 }
4265
4266 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4267 {
4268 struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
4269 struct sk_security_struct *sksec = sk->sk_security;
4270
4271 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4272 sk->sk_family == PF_UNIX)
4273 isec->sid = sksec->sid;
4274 sksec->sclass = isec->sclass;
4275 }
4276
4277 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4278 struct request_sock *req)
4279 {
4280 struct sk_security_struct *sksec = sk->sk_security;
4281 int err;
4282 u16 family = sk->sk_family;
4283 u32 newsid;
4284 u32 peersid;
4285
4286 /* handle mapped IPv4 packets arriving via IPv6 sockets */
4287 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4288 family = PF_INET;
4289
4290 err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4291 if (err)
4292 return err;
4293 if (peersid == SECSID_NULL) {
4294 req->secid = sksec->sid;
4295 req->peer_secid = SECSID_NULL;
4296 } else {
4297 err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
4298 if (err)
4299 return err;
4300 req->secid = newsid;
4301 req->peer_secid = peersid;
4302 }
4303
4304 return selinux_netlbl_inet_conn_request(req, family);
4305 }
4306
4307 static void selinux_inet_csk_clone(struct sock *newsk,
4308 const struct request_sock *req)
4309 {
4310 struct sk_security_struct *newsksec = newsk->sk_security;
4311
4312 newsksec->sid = req->secid;
4313 newsksec->peer_sid = req->peer_secid;
4314 /* NOTE: Ideally, we should also get the isec->sid for the
4315 new socket in sync, but we don't have the isec available yet.
4316 So we will wait until sock_graft to do it, by which
4317 time it will have been created and available. */
4318
4319 /* We don't need to take any sort of lock here as we are the only
4320 * thread with access to newsksec */
4321 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4322 }
4323
4324 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4325 {
4326 u16 family = sk->sk_family;
4327 struct sk_security_struct *sksec = sk->sk_security;
4328
4329 /* handle mapped IPv4 packets arriving via IPv6 sockets */
4330 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4331 family = PF_INET;
4332
4333 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4334 }
4335
4336 static void selinux_req_classify_flow(const struct request_sock *req,
4337 struct flowi *fl)
4338 {
4339 fl->secid = req->secid;
4340 }
4341
4342 static int selinux_tun_dev_create(void)
4343 {
4344 u32 sid = current_sid();
4345
4346 /* we aren't taking into account the "sockcreate" SID since the socket
4347 * that is being created here is not a socket in the traditional sense,
4348 * instead it is a private sock, accessible only to the kernel, and
4349 * representing a wide range of network traffic spanning multiple
4350 * connections unlike traditional sockets - check the TUN driver to
4351 * get a better understanding of why this socket is special */
4352
4353 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4354 NULL);
4355 }
4356
4357 static void selinux_tun_dev_post_create(struct sock *sk)
4358 {
4359 struct sk_security_struct *sksec = sk->sk_security;
4360
4361 /* we don't currently perform any NetLabel based labeling here and it
4362 * isn't clear that we would want to do so anyway; while we could apply
4363 * labeling without the support of the TUN user the resulting labeled
4364 * traffic from the other end of the connection would almost certainly
4365 * cause confusion to the TUN user that had no idea network labeling
4366 * protocols were being used */
4367
4368 /* see the comments in selinux_tun_dev_create() about why we don't use
4369 * the sockcreate SID here */
4370
4371 sksec->sid = current_sid();
4372 sksec->sclass = SECCLASS_TUN_SOCKET;
4373 }
4374
4375 static int selinux_tun_dev_attach(struct sock *sk)
4376 {
4377 struct sk_security_struct *sksec = sk->sk_security;
4378 u32 sid = current_sid();
4379 int err;
4380
4381 err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET,
4382 TUN_SOCKET__RELABELFROM, NULL);
4383 if (err)
4384 return err;
4385 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4386 TUN_SOCKET__RELABELTO, NULL);
4387 if (err)
4388 return err;
4389
4390 sksec->sid = sid;
4391
4392 return 0;
4393 }
4394
4395 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4396 {
4397 int err = 0;
4398 u32 perm;
4399 struct nlmsghdr *nlh;
4400 struct socket *sock = sk->sk_socket;
4401 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
4402
4403 if (skb->len < NLMSG_SPACE(0)) {
4404 err = -EINVAL;
4405 goto out;
4406 }
4407 nlh = nlmsg_hdr(skb);
4408
4409 err = selinux_nlmsg_lookup(isec->sclass, nlh->nlmsg_type, &perm);
4410 if (err) {
4411 if (err == -EINVAL) {
4412 audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
4413 "SELinux: unrecognized netlink message"
4414 " type=%hu for sclass=%hu\n",
4415 nlh->nlmsg_type, isec->sclass);
4416 if (!selinux_enforcing || security_get_allow_unknown())
4417 err = 0;
4418 }
4419
4420 /* Ignore */
4421 if (err == -ENOENT)
4422 err = 0;
4423 goto out;
4424 }
4425
4426 err = socket_has_perm(current, sock, perm);
4427 out:
4428 return err;
4429 }
4430
4431 #ifdef CONFIG_NETFILTER
4432
4433 static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
4434 u16 family)
4435 {
4436 int err;
4437 char *addrp;
4438 u32 peer_sid;
4439 struct common_audit_data ad;
4440 u8 secmark_active;
4441 u8 netlbl_active;
4442 u8 peerlbl_active;
4443
4444 if (!selinux_policycap_netpeer)
4445 return NF_ACCEPT;
4446
4447 secmark_active = selinux_secmark_enabled();
4448 netlbl_active = netlbl_enabled();
4449 peerlbl_active = netlbl_active || selinux_xfrm_enabled();
4450 if (!secmark_active && !peerlbl_active)
4451 return NF_ACCEPT;
4452
4453 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
4454 return NF_DROP;
4455
4456 COMMON_AUDIT_DATA_INIT(&ad, NET);
4457 ad.u.net.netif = ifindex;
4458 ad.u.net.family = family;
4459 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
4460 return NF_DROP;
4461
4462 if (peerlbl_active) {
4463 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
4464 peer_sid, &ad);
4465 if (err) {
4466 selinux_netlbl_err(skb, err, 1);
4467 return NF_DROP;
4468 }
4469 }
4470
4471 if (secmark_active)
4472 if (avc_has_perm(peer_sid, skb->secmark,
4473 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
4474 return NF_DROP;
4475
4476 if (netlbl_active)
4477 /* we do this in the FORWARD path and not the POST_ROUTING
4478 * path because we want to make sure we apply the necessary
4479 * labeling before IPsec is applied so we can leverage AH
4480 * protection */
4481 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
4482 return NF_DROP;
4483
4484 return NF_ACCEPT;
4485 }
4486
4487 static unsigned int selinux_ipv4_forward(unsigned int hooknum,
4488 struct sk_buff *skb,
4489 const struct net_device *in,
4490 const struct net_device *out,
4491 int (*okfn)(struct sk_buff *))
4492 {
4493 return selinux_ip_forward(skb, in->ifindex, PF_INET);
4494 }
4495
4496 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4497 static unsigned int selinux_ipv6_forward(unsigned int hooknum,
4498 struct sk_buff *skb,
4499 const struct net_device *in,
4500 const struct net_device *out,
4501 int (*okfn)(struct sk_buff *))
4502 {
4503 return selinux_ip_forward(skb, in->ifindex, PF_INET6);
4504 }
4505 #endif /* IPV6 */
4506
4507 static unsigned int selinux_ip_output(struct sk_buff *skb,
4508 u16 family)
4509 {
4510 u32 sid;
4511
4512 if (!netlbl_enabled())
4513 return NF_ACCEPT;
4514
4515 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
4516 * because we want to make sure we apply the necessary labeling
4517 * before IPsec is applied so we can leverage AH protection */
4518 if (skb->sk) {
4519 struct sk_security_struct *sksec = skb->sk->sk_security;
4520 sid = sksec->sid;
4521 } else
4522 sid = SECINITSID_KERNEL;
4523 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
4524 return NF_DROP;
4525
4526 return NF_ACCEPT;
4527 }
4528
4529 static unsigned int selinux_ipv4_output(unsigned int hooknum,
4530 struct sk_buff *skb,
4531 const struct net_device *in,
4532 const struct net_device *out,
4533 int (*okfn)(struct sk_buff *))
4534 {
4535 return selinux_ip_output(skb, PF_INET);
4536 }
4537
4538 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
4539 int ifindex,
4540 u16 family)
4541 {
4542 struct sock *sk = skb->sk;
4543 struct sk_security_struct *sksec;
4544 struct common_audit_data ad;
4545 char *addrp;
4546 u8 proto;
4547
4548 if (sk == NULL)
4549 return NF_ACCEPT;
4550 sksec = sk->sk_security;
4551
4552 COMMON_AUDIT_DATA_INIT(&ad, NET);
4553 ad.u.net.netif = ifindex;
4554 ad.u.net.family = family;
4555 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
4556 return NF_DROP;
4557
4558 if (selinux_secmark_enabled())
4559 if (avc_has_perm(sksec->sid, skb->secmark,
4560 SECCLASS_PACKET, PACKET__SEND, &ad))
4561 return NF_DROP;
4562
4563 if (selinux_policycap_netpeer)
4564 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
4565 return NF_DROP;
4566
4567 return NF_ACCEPT;
4568 }
4569
4570 static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
4571 u16 family)
4572 {
4573 u32 secmark_perm;
4574 u32 peer_sid;
4575 struct sock *sk;
4576 struct common_audit_data ad;
4577 char *addrp;
4578 u8 secmark_active;
4579 u8 peerlbl_active;
4580
4581 /* If any sort of compatibility mode is enabled then handoff processing
4582 * to the selinux_ip_postroute_compat() function to deal with the
4583 * special handling. We do this in an attempt to keep this function
4584 * as fast and as clean as possible. */
4585 if (!selinux_policycap_netpeer)
4586 return selinux_ip_postroute_compat(skb, ifindex, family);
4587 #ifdef CONFIG_XFRM
4588 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
4589 * packet transformation so allow the packet to pass without any checks
4590 * since we'll have another chance to perform access control checks
4591 * when the packet is on it's final way out.
4592 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
4593 * is NULL, in this case go ahead and apply access control. */
4594 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
4595 return NF_ACCEPT;
4596 #endif
4597 secmark_active = selinux_secmark_enabled();
4598 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4599 if (!secmark_active && !peerlbl_active)
4600 return NF_ACCEPT;
4601
4602 /* if the packet is being forwarded then get the peer label from the
4603 * packet itself; otherwise check to see if it is from a local
4604 * application or the kernel, if from an application get the peer label
4605 * from the sending socket, otherwise use the kernel's sid */
4606 sk = skb->sk;
4607 if (sk == NULL) {
4608 switch (family) {
4609 case PF_INET:
4610 if (IPCB(skb)->flags & IPSKB_FORWARDED)
4611 secmark_perm = PACKET__FORWARD_OUT;
4612 else
4613 secmark_perm = PACKET__SEND;
4614 break;
4615 case PF_INET6:
4616 if (IP6CB(skb)->flags & IP6SKB_FORWARDED)
4617 secmark_perm = PACKET__FORWARD_OUT;
4618 else
4619 secmark_perm = PACKET__SEND;
4620 break;
4621 default:
4622 return NF_DROP;
4623 }
4624 if (secmark_perm == PACKET__FORWARD_OUT) {
4625 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4626 return NF_DROP;
4627 } else
4628 peer_sid = SECINITSID_KERNEL;
4629 } else {
4630 struct sk_security_struct *sksec = sk->sk_security;
4631 peer_sid = sksec->sid;
4632 secmark_perm = PACKET__SEND;
4633 }
4634
4635 COMMON_AUDIT_DATA_INIT(&ad, NET);
4636 ad.u.net.netif = ifindex;
4637 ad.u.net.family = family;
4638 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4639 return NF_DROP;
4640
4641 if (secmark_active)
4642 if (avc_has_perm(peer_sid, skb->secmark,
4643 SECCLASS_PACKET, secmark_perm, &ad))
4644 return NF_DROP;
4645
4646 if (peerlbl_active) {
4647 u32 if_sid;
4648 u32 node_sid;
4649
4650 if (sel_netif_sid(ifindex, &if_sid))
4651 return NF_DROP;
4652 if (avc_has_perm(peer_sid, if_sid,
4653 SECCLASS_NETIF, NETIF__EGRESS, &ad))
4654 return NF_DROP;
4655
4656 if (sel_netnode_sid(addrp, family, &node_sid))
4657 return NF_DROP;
4658 if (avc_has_perm(peer_sid, node_sid,
4659 SECCLASS_NODE, NODE__SENDTO, &ad))
4660 return NF_DROP;
4661 }
4662
4663 return NF_ACCEPT;
4664 }
4665
4666 static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
4667 struct sk_buff *skb,
4668 const struct net_device *in,
4669 const struct net_device *out,
4670 int (*okfn)(struct sk_buff *))
4671 {
4672 return selinux_ip_postroute(skb, out->ifindex, PF_INET);
4673 }
4674
4675 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4676 static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
4677 struct sk_buff *skb,
4678 const struct net_device *in,
4679 const struct net_device *out,
4680 int (*okfn)(struct sk_buff *))
4681 {
4682 return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
4683 }
4684 #endif /* IPV6 */
4685
4686 #endif /* CONFIG_NETFILTER */
4687
4688 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
4689 {
4690 int err;
4691
4692 err = cap_netlink_send(sk, skb);
4693 if (err)
4694 return err;
4695
4696 return selinux_nlmsg_perm(sk, skb);
4697 }
4698
4699 static int selinux_netlink_recv(struct sk_buff *skb, int capability)
4700 {
4701 int err;
4702 struct common_audit_data ad;
4703
4704 err = cap_netlink_recv(skb, capability);
4705 if (err)
4706 return err;
4707
4708 COMMON_AUDIT_DATA_INIT(&ad, CAP);
4709 ad.u.cap = capability;
4710
4711 return avc_has_perm(NETLINK_CB(skb).sid, NETLINK_CB(skb).sid,
4712 SECCLASS_CAPABILITY, CAP_TO_MASK(capability), &ad);
4713 }
4714
4715 static int ipc_alloc_security(struct task_struct *task,
4716 struct kern_ipc_perm *perm,
4717 u16 sclass)
4718 {
4719 struct ipc_security_struct *isec;
4720 u32 sid;
4721
4722 isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
4723 if (!isec)
4724 return -ENOMEM;
4725
4726 sid = task_sid(task);
4727 isec->sclass = sclass;
4728 isec->sid = sid;
4729 perm->security = isec;
4730
4731 return 0;
4732 }
4733
4734 static void ipc_free_security(struct kern_ipc_perm *perm)
4735 {
4736 struct ipc_security_struct *isec = perm->security;
4737 perm->security = NULL;
4738 kfree(isec);
4739 }
4740
4741 static int msg_msg_alloc_security(struct msg_msg *msg)
4742 {
4743 struct msg_security_struct *msec;
4744
4745 msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
4746 if (!msec)
4747 return -ENOMEM;
4748
4749 msec->sid = SECINITSID_UNLABELED;
4750 msg->security = msec;
4751
4752 return 0;
4753 }
4754
4755 static void msg_msg_free_security(struct msg_msg *msg)
4756 {
4757 struct msg_security_struct *msec = msg->security;
4758
4759 msg->security = NULL;
4760 kfree(msec);
4761 }
4762
4763 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
4764 u32 perms)
4765 {
4766 struct ipc_security_struct *isec;
4767 struct common_audit_data ad;
4768 u32 sid = current_sid();
4769
4770 isec = ipc_perms->security;
4771
4772 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4773 ad.u.ipc_id = ipc_perms->key;
4774
4775 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
4776 }
4777
4778 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
4779 {
4780 return msg_msg_alloc_security(msg);
4781 }
4782
4783 static void selinux_msg_msg_free_security(struct msg_msg *msg)
4784 {
4785 msg_msg_free_security(msg);
4786 }
4787
4788 /* message queue security operations */
4789 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
4790 {
4791 struct ipc_security_struct *isec;
4792 struct common_audit_data ad;
4793 u32 sid = current_sid();
4794 int rc;
4795
4796 rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
4797 if (rc)
4798 return rc;
4799
4800 isec = msq->q_perm.security;
4801
4802 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4803 ad.u.ipc_id = msq->q_perm.key;
4804
4805 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4806 MSGQ__CREATE, &ad);
4807 if (rc) {
4808 ipc_free_security(&msq->q_perm);
4809 return rc;
4810 }
4811 return 0;
4812 }
4813
4814 static void selinux_msg_queue_free_security(struct msg_queue *msq)
4815 {
4816 ipc_free_security(&msq->q_perm);
4817 }
4818
4819 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
4820 {
4821 struct ipc_security_struct *isec;
4822 struct common_audit_data ad;
4823 u32 sid = current_sid();
4824
4825 isec = msq->q_perm.security;
4826
4827 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4828 ad.u.ipc_id = msq->q_perm.key;
4829
4830 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4831 MSGQ__ASSOCIATE, &ad);
4832 }
4833
4834 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
4835 {
4836 int err;
4837 int perms;
4838
4839 switch (cmd) {
4840 case IPC_INFO:
4841 case MSG_INFO:
4842 /* No specific object, just general system-wide information. */
4843 return task_has_system(current, SYSTEM__IPC_INFO);
4844 case IPC_STAT:
4845 case MSG_STAT:
4846 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
4847 break;
4848 case IPC_SET:
4849 perms = MSGQ__SETATTR;
4850 break;
4851 case IPC_RMID:
4852 perms = MSGQ__DESTROY;
4853 break;
4854 default:
4855 return 0;
4856 }
4857
4858 err = ipc_has_perm(&msq->q_perm, perms);
4859 return err;
4860 }
4861
4862 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
4863 {
4864 struct ipc_security_struct *isec;
4865 struct msg_security_struct *msec;
4866 struct common_audit_data ad;
4867 u32 sid = current_sid();
4868 int rc;
4869
4870 isec = msq->q_perm.security;
4871 msec = msg->security;
4872
4873 /*
4874 * First time through, need to assign label to the message
4875 */
4876 if (msec->sid == SECINITSID_UNLABELED) {
4877 /*
4878 * Compute new sid based on current process and
4879 * message queue this message will be stored in
4880 */
4881 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
4882 &msec->sid);
4883 if (rc)
4884 return rc;
4885 }
4886
4887 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4888 ad.u.ipc_id = msq->q_perm.key;
4889
4890 /* Can this process write to the queue? */
4891 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4892 MSGQ__WRITE, &ad);
4893 if (!rc)
4894 /* Can this process send the message */
4895 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
4896 MSG__SEND, &ad);
4897 if (!rc)
4898 /* Can the message be put in the queue? */
4899 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
4900 MSGQ__ENQUEUE, &ad);
4901
4902 return rc;
4903 }
4904
4905 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
4906 struct task_struct *target,
4907 long type, int mode)
4908 {
4909 struct ipc_security_struct *isec;
4910 struct msg_security_struct *msec;
4911 struct common_audit_data ad;
4912 u32 sid = task_sid(target);
4913 int rc;
4914
4915 isec = msq->q_perm.security;
4916 msec = msg->security;
4917
4918 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4919 ad.u.ipc_id = msq->q_perm.key;
4920
4921 rc = avc_has_perm(sid, isec->sid,
4922 SECCLASS_MSGQ, MSGQ__READ, &ad);
4923 if (!rc)
4924 rc = avc_has_perm(sid, msec->sid,
4925 SECCLASS_MSG, MSG__RECEIVE, &ad);
4926 return rc;
4927 }
4928
4929 /* Shared Memory security operations */
4930 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
4931 {
4932 struct ipc_security_struct *isec;
4933 struct common_audit_data ad;
4934 u32 sid = current_sid();
4935 int rc;
4936
4937 rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
4938 if (rc)
4939 return rc;
4940
4941 isec = shp->shm_perm.security;
4942
4943 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4944 ad.u.ipc_id = shp->shm_perm.key;
4945
4946 rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
4947 SHM__CREATE, &ad);
4948 if (rc) {
4949 ipc_free_security(&shp->shm_perm);
4950 return rc;
4951 }
4952 return 0;
4953 }
4954
4955 static void selinux_shm_free_security(struct shmid_kernel *shp)
4956 {
4957 ipc_free_security(&shp->shm_perm);
4958 }
4959
4960 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
4961 {
4962 struct ipc_security_struct *isec;
4963 struct common_audit_data ad;
4964 u32 sid = current_sid();
4965
4966 isec = shp->shm_perm.security;
4967
4968 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4969 ad.u.ipc_id = shp->shm_perm.key;
4970
4971 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
4972 SHM__ASSOCIATE, &ad);
4973 }
4974
4975 /* Note, at this point, shp is locked down */
4976 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
4977 {
4978 int perms;
4979 int err;
4980
4981 switch (cmd) {
4982 case IPC_INFO:
4983 case SHM_INFO:
4984 /* No specific object, just general system-wide information. */
4985 return task_has_system(current, SYSTEM__IPC_INFO);
4986 case IPC_STAT:
4987 case SHM_STAT:
4988 perms = SHM__GETATTR | SHM__ASSOCIATE;
4989 break;
4990 case IPC_SET:
4991 perms = SHM__SETATTR;
4992 break;
4993 case SHM_LOCK:
4994 case SHM_UNLOCK:
4995 perms = SHM__LOCK;
4996 break;
4997 case IPC_RMID:
4998 perms = SHM__DESTROY;
4999 break;
5000 default:
5001 return 0;
5002 }
5003
5004 err = ipc_has_perm(&shp->shm_perm, perms);
5005 return err;
5006 }
5007
5008 static int selinux_shm_shmat(struct shmid_kernel *shp,
5009 char __user *shmaddr, int shmflg)
5010 {
5011 u32 perms;
5012
5013 if (shmflg & SHM_RDONLY)
5014 perms = SHM__READ;
5015 else
5016 perms = SHM__READ | SHM__WRITE;
5017
5018 return ipc_has_perm(&shp->shm_perm, perms);
5019 }
5020
5021 /* Semaphore security operations */
5022 static int selinux_sem_alloc_security(struct sem_array *sma)
5023 {
5024 struct ipc_security_struct *isec;
5025 struct common_audit_data ad;
5026 u32 sid = current_sid();
5027 int rc;
5028
5029 rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
5030 if (rc)
5031 return rc;
5032
5033 isec = sma->sem_perm.security;
5034
5035 COMMON_AUDIT_DATA_INIT(&ad, IPC);
5036 ad.u.ipc_id = sma->sem_perm.key;
5037
5038 rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5039 SEM__CREATE, &ad);
5040 if (rc) {
5041 ipc_free_security(&sma->sem_perm);
5042 return rc;
5043 }
5044 return 0;
5045 }
5046
5047 static void selinux_sem_free_security(struct sem_array *sma)
5048 {
5049 ipc_free_security(&sma->sem_perm);
5050 }
5051
5052 static int selinux_sem_associate(struct sem_array *sma, int semflg)
5053 {
5054 struct ipc_security_struct *isec;
5055 struct common_audit_data ad;
5056 u32 sid = current_sid();
5057
5058 isec = sma->sem_perm.security;
5059
5060 COMMON_AUDIT_DATA_INIT(&ad, IPC);
5061 ad.u.ipc_id = sma->sem_perm.key;
5062
5063 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5064 SEM__ASSOCIATE, &ad);
5065 }
5066
5067 /* Note, at this point, sma is locked down */
5068 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5069 {
5070 int err;
5071 u32 perms;
5072
5073 switch (cmd) {
5074 case IPC_INFO:
5075 case SEM_INFO:
5076 /* No specific object, just general system-wide information. */
5077 return task_has_system(current, SYSTEM__IPC_INFO);
5078 case GETPID:
5079 case GETNCNT:
5080 case GETZCNT:
5081 perms = SEM__GETATTR;
5082 break;
5083 case GETVAL:
5084 case GETALL:
5085 perms = SEM__READ;
5086 break;
5087 case SETVAL:
5088 case SETALL:
5089 perms = SEM__WRITE;
5090 break;
5091 case IPC_RMID:
5092 perms = SEM__DESTROY;
5093 break;
5094 case IPC_SET:
5095 perms = SEM__SETATTR;
5096 break;
5097 case IPC_STAT:
5098 case SEM_STAT:
5099 perms = SEM__GETATTR | SEM__ASSOCIATE;
5100 break;
5101 default:
5102 return 0;
5103 }
5104
5105 err = ipc_has_perm(&sma->sem_perm, perms);
5106 return err;
5107 }
5108
5109 static int selinux_sem_semop(struct sem_array *sma,
5110 struct sembuf *sops, unsigned nsops, int alter)
5111 {
5112 u32 perms;
5113
5114 if (alter)
5115 perms = SEM__READ | SEM__WRITE;
5116 else
5117 perms = SEM__READ;
5118
5119 return ipc_has_perm(&sma->sem_perm, perms);
5120 }
5121
5122 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5123 {
5124 u32 av = 0;
5125
5126 av = 0;
5127 if (flag & S_IRUGO)
5128 av |= IPC__UNIX_READ;
5129 if (flag & S_IWUGO)
5130 av |= IPC__UNIX_WRITE;
5131
5132 if (av == 0)
5133 return 0;
5134
5135 return ipc_has_perm(ipcp, av);
5136 }
5137
5138 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5139 {
5140 struct ipc_security_struct *isec = ipcp->security;
5141 *secid = isec->sid;
5142 }
5143
5144 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5145 {
5146 if (inode)
5147 inode_doinit_with_dentry(inode, dentry);
5148 }
5149
5150 static int selinux_getprocattr(struct task_struct *p,
5151 char *name, char **value)
5152 {
5153 const struct task_security_struct *__tsec;
5154 u32 sid;
5155 int error;
5156 unsigned len;
5157
5158 if (current != p) {
5159 error = current_has_perm(p, PROCESS__GETATTR);
5160 if (error)
5161 return error;
5162 }
5163
5164 rcu_read_lock();
5165 __tsec = __task_cred(p)->security;
5166
5167 if (!strcmp(name, "current"))
5168 sid = __tsec->sid;
5169 else if (!strcmp(name, "prev"))
5170 sid = __tsec->osid;
5171 else if (!strcmp(name, "exec"))
5172 sid = __tsec->exec_sid;
5173 else if (!strcmp(name, "fscreate"))
5174 sid = __tsec->create_sid;
5175 else if (!strcmp(name, "keycreate"))
5176 sid = __tsec->keycreate_sid;
5177 else if (!strcmp(name, "sockcreate"))
5178 sid = __tsec->sockcreate_sid;
5179 else
5180 goto invalid;
5181 rcu_read_unlock();
5182
5183 if (!sid)
5184 return 0;
5185
5186 error = security_sid_to_context(sid, value, &len);
5187 if (error)
5188 return error;
5189 return len;
5190
5191 invalid:
5192 rcu_read_unlock();
5193 return -EINVAL;
5194 }
5195
5196 static int selinux_setprocattr(struct task_struct *p,
5197 char *name, void *value, size_t size)
5198 {
5199 struct task_security_struct *tsec;
5200 struct task_struct *tracer;
5201 struct cred *new;
5202 u32 sid = 0, ptsid;
5203 int error;
5204 char *str = value;
5205
5206 if (current != p) {
5207 /* SELinux only allows a process to change its own
5208 security attributes. */
5209 return -EACCES;
5210 }
5211
5212 /*
5213 * Basic control over ability to set these attributes at all.
5214 * current == p, but we'll pass them separately in case the
5215 * above restriction is ever removed.
5216 */
5217 if (!strcmp(name, "exec"))
5218 error = current_has_perm(p, PROCESS__SETEXEC);
5219 else if (!strcmp(name, "fscreate"))
5220 error = current_has_perm(p, PROCESS__SETFSCREATE);
5221 else if (!strcmp(name, "keycreate"))
5222 error = current_has_perm(p, PROCESS__SETKEYCREATE);
5223 else if (!strcmp(name, "sockcreate"))
5224 error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5225 else if (!strcmp(name, "current"))
5226 error = current_has_perm(p, PROCESS__SETCURRENT);
5227 else
5228 error = -EINVAL;
5229 if (error)
5230 return error;
5231
5232 /* Obtain a SID for the context, if one was specified. */
5233 if (size && str[1] && str[1] != '\n') {
5234 if (str[size-1] == '\n') {
5235 str[size-1] = 0;
5236 size--;
5237 }
5238 error = security_context_to_sid(value, size, &sid);
5239 if (error == -EINVAL && !strcmp(name, "fscreate")) {
5240 if (!capable(CAP_MAC_ADMIN))
5241 return error;
5242 error = security_context_to_sid_force(value, size,
5243 &sid);
5244 }
5245 if (error)
5246 return error;
5247 }
5248
5249 new = prepare_creds();
5250 if (!new)
5251 return -ENOMEM;
5252
5253 /* Permission checking based on the specified context is
5254 performed during the actual operation (execve,
5255 open/mkdir/...), when we know the full context of the
5256 operation. See selinux_bprm_set_creds for the execve
5257 checks and may_create for the file creation checks. The
5258 operation will then fail if the context is not permitted. */
5259 tsec = new->security;
5260 if (!strcmp(name, "exec")) {
5261 tsec->exec_sid = sid;
5262 } else if (!strcmp(name, "fscreate")) {
5263 tsec->create_sid = sid;
5264 } else if (!strcmp(name, "keycreate")) {
5265 error = may_create_key(sid, p);
5266 if (error)
5267 goto abort_change;
5268 tsec->keycreate_sid = sid;
5269 } else if (!strcmp(name, "sockcreate")) {
5270 tsec->sockcreate_sid = sid;
5271 } else if (!strcmp(name, "current")) {
5272 error = -EINVAL;
5273 if (sid == 0)
5274 goto abort_change;
5275
5276 /* Only allow single threaded processes to change context */
5277 error = -EPERM;
5278 if (!current_is_single_threaded()) {
5279 error = security_bounded_transition(tsec->sid, sid);
5280 if (error)
5281 goto abort_change;
5282 }
5283
5284 /* Check permissions for the transition. */
5285 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5286 PROCESS__DYNTRANSITION, NULL);
5287 if (error)
5288 goto abort_change;
5289
5290 /* Check for ptracing, and update the task SID if ok.
5291 Otherwise, leave SID unchanged and fail. */
5292 ptsid = 0;
5293 task_lock(p);
5294 tracer = tracehook_tracer_task(p);
5295 if (tracer)
5296 ptsid = task_sid(tracer);
5297 task_unlock(p);
5298
5299 if (tracer) {
5300 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5301 PROCESS__PTRACE, NULL);
5302 if (error)
5303 goto abort_change;
5304 }
5305
5306 tsec->sid = sid;
5307 } else {
5308 error = -EINVAL;
5309 goto abort_change;
5310 }
5311
5312 commit_creds(new);
5313 return size;
5314
5315 abort_change:
5316 abort_creds(new);
5317 return error;
5318 }
5319
5320 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5321 {
5322 return security_sid_to_context(secid, secdata, seclen);
5323 }
5324
5325 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5326 {
5327 return security_context_to_sid(secdata, seclen, secid);
5328 }
5329
5330 static void selinux_release_secctx(char *secdata, u32 seclen)
5331 {
5332 kfree(secdata);
5333 }
5334
5335 /*
5336 * called with inode->i_mutex locked
5337 */
5338 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5339 {
5340 return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5341 }
5342
5343 /*
5344 * called with inode->i_mutex locked
5345 */
5346 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
5347 {
5348 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
5349 }
5350
5351 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
5352 {
5353 int len = 0;
5354 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
5355 ctx, true);
5356 if (len < 0)
5357 return len;
5358 *ctxlen = len;
5359 return 0;
5360 }
5361 #ifdef CONFIG_KEYS
5362
5363 static int selinux_key_alloc(struct key *k, const struct cred *cred,
5364 unsigned long flags)
5365 {
5366 const struct task_security_struct *tsec;
5367 struct key_security_struct *ksec;
5368
5369 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
5370 if (!ksec)
5371 return -ENOMEM;
5372
5373 tsec = cred->security;
5374 if (tsec->keycreate_sid)
5375 ksec->sid = tsec->keycreate_sid;
5376 else
5377 ksec->sid = tsec->sid;
5378
5379 k->security = ksec;
5380 return 0;
5381 }
5382
5383 static void selinux_key_free(struct key *k)
5384 {
5385 struct key_security_struct *ksec = k->security;
5386
5387 k->security = NULL;
5388 kfree(ksec);
5389 }
5390
5391 static int selinux_key_permission(key_ref_t key_ref,
5392 const struct cred *cred,
5393 key_perm_t perm)
5394 {
5395 struct key *key;
5396 struct key_security_struct *ksec;
5397 u32 sid;
5398
5399 /* if no specific permissions are requested, we skip the
5400 permission check. No serious, additional covert channels
5401 appear to be created. */
5402 if (perm == 0)
5403 return 0;
5404
5405 sid = cred_sid(cred);
5406
5407 key = key_ref_to_ptr(key_ref);
5408 ksec = key->security;
5409
5410 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5411 }
5412
5413 static int selinux_key_getsecurity(struct key *key, char **_buffer)
5414 {
5415 struct key_security_struct *ksec = key->security;
5416 char *context = NULL;
5417 unsigned len;
5418 int rc;
5419
5420 rc = security_sid_to_context(ksec->sid, &context, &len);
5421 if (!rc)
5422 rc = len;
5423 *_buffer = context;
5424 return rc;
5425 }
5426
5427 #endif
5428
5429 static struct security_operations selinux_ops = {
5430 .name = "selinux",
5431
5432 .ptrace_access_check = selinux_ptrace_access_check,
5433 .ptrace_traceme = selinux_ptrace_traceme,
5434 .capget = selinux_capget,
5435 .capset = selinux_capset,
5436 .sysctl = selinux_sysctl,
5437 .capable = selinux_capable,
5438 .quotactl = selinux_quotactl,
5439 .quota_on = selinux_quota_on,
5440 .syslog = selinux_syslog,
5441 .vm_enough_memory = selinux_vm_enough_memory,
5442
5443 .netlink_send = selinux_netlink_send,
5444 .netlink_recv = selinux_netlink_recv,
5445
5446 .bprm_set_creds = selinux_bprm_set_creds,
5447 .bprm_committing_creds = selinux_bprm_committing_creds,
5448 .bprm_committed_creds = selinux_bprm_committed_creds,
5449 .bprm_secureexec = selinux_bprm_secureexec,
5450
5451 .sb_alloc_security = selinux_sb_alloc_security,
5452 .sb_free_security = selinux_sb_free_security,
5453 .sb_copy_data = selinux_sb_copy_data,
5454 .sb_kern_mount = selinux_sb_kern_mount,
5455 .sb_show_options = selinux_sb_show_options,
5456 .sb_statfs = selinux_sb_statfs,
5457 .sb_mount = selinux_mount,
5458 .sb_umount = selinux_umount,
5459 .sb_set_mnt_opts = selinux_set_mnt_opts,
5460 .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts,
5461 .sb_parse_opts_str = selinux_parse_opts_str,
5462
5463
5464 .inode_alloc_security = selinux_inode_alloc_security,
5465 .inode_free_security = selinux_inode_free_security,
5466 .inode_init_security = selinux_inode_init_security,
5467 .inode_create = selinux_inode_create,
5468 .inode_link = selinux_inode_link,
5469 .inode_unlink = selinux_inode_unlink,
5470 .inode_symlink = selinux_inode_symlink,
5471 .inode_mkdir = selinux_inode_mkdir,
5472 .inode_rmdir = selinux_inode_rmdir,
5473 .inode_mknod = selinux_inode_mknod,
5474 .inode_rename = selinux_inode_rename,
5475 .inode_readlink = selinux_inode_readlink,
5476 .inode_follow_link = selinux_inode_follow_link,
5477 .inode_permission = selinux_inode_permission,
5478 .inode_setattr = selinux_inode_setattr,
5479 .inode_getattr = selinux_inode_getattr,
5480 .inode_setxattr = selinux_inode_setxattr,
5481 .inode_post_setxattr = selinux_inode_post_setxattr,
5482 .inode_getxattr = selinux_inode_getxattr,
5483 .inode_listxattr = selinux_inode_listxattr,
5484 .inode_removexattr = selinux_inode_removexattr,
5485 .inode_getsecurity = selinux_inode_getsecurity,
5486 .inode_setsecurity = selinux_inode_setsecurity,
5487 .inode_listsecurity = selinux_inode_listsecurity,
5488 .inode_getsecid = selinux_inode_getsecid,
5489
5490 .file_permission = selinux_file_permission,
5491 .file_alloc_security = selinux_file_alloc_security,
5492 .file_free_security = selinux_file_free_security,
5493 .file_ioctl = selinux_file_ioctl,
5494 .file_mmap = selinux_file_mmap,
5495 .file_mprotect = selinux_file_mprotect,
5496 .file_lock = selinux_file_lock,
5497 .file_fcntl = selinux_file_fcntl,
5498 .file_set_fowner = selinux_file_set_fowner,
5499 .file_send_sigiotask = selinux_file_send_sigiotask,
5500 .file_receive = selinux_file_receive,
5501
5502 .dentry_open = selinux_dentry_open,
5503
5504 .task_create = selinux_task_create,
5505 .cred_alloc_blank = selinux_cred_alloc_blank,
5506 .cred_free = selinux_cred_free,
5507 .cred_prepare = selinux_cred_prepare,
5508 .cred_transfer = selinux_cred_transfer,
5509 .kernel_act_as = selinux_kernel_act_as,
5510 .kernel_create_files_as = selinux_kernel_create_files_as,
5511 .kernel_module_request = selinux_kernel_module_request,
5512 .task_setpgid = selinux_task_setpgid,
5513 .task_getpgid = selinux_task_getpgid,
5514 .task_getsid = selinux_task_getsid,
5515 .task_getsecid = selinux_task_getsecid,
5516 .task_setnice = selinux_task_setnice,
5517 .task_setioprio = selinux_task_setioprio,
5518 .task_getioprio = selinux_task_getioprio,
5519 .task_setrlimit = selinux_task_setrlimit,
5520 .task_setscheduler = selinux_task_setscheduler,
5521 .task_getscheduler = selinux_task_getscheduler,
5522 .task_movememory = selinux_task_movememory,
5523 .task_kill = selinux_task_kill,
5524 .task_wait = selinux_task_wait,
5525 .task_to_inode = selinux_task_to_inode,
5526
5527 .ipc_permission = selinux_ipc_permission,
5528 .ipc_getsecid = selinux_ipc_getsecid,
5529
5530 .msg_msg_alloc_security = selinux_msg_msg_alloc_security,
5531 .msg_msg_free_security = selinux_msg_msg_free_security,
5532
5533 .msg_queue_alloc_security = selinux_msg_queue_alloc_security,
5534 .msg_queue_free_security = selinux_msg_queue_free_security,
5535 .msg_queue_associate = selinux_msg_queue_associate,
5536 .msg_queue_msgctl = selinux_msg_queue_msgctl,
5537 .msg_queue_msgsnd = selinux_msg_queue_msgsnd,
5538 .msg_queue_msgrcv = selinux_msg_queue_msgrcv,
5539
5540 .shm_alloc_security = selinux_shm_alloc_security,
5541 .shm_free_security = selinux_shm_free_security,
5542 .shm_associate = selinux_shm_associate,
5543 .shm_shmctl = selinux_shm_shmctl,
5544 .shm_shmat = selinux_shm_shmat,
5545
5546 .sem_alloc_security = selinux_sem_alloc_security,
5547 .sem_free_security = selinux_sem_free_security,
5548 .sem_associate = selinux_sem_associate,
5549 .sem_semctl = selinux_sem_semctl,
5550 .sem_semop = selinux_sem_semop,
5551
5552 .d_instantiate = selinux_d_instantiate,
5553
5554 .getprocattr = selinux_getprocattr,
5555 .setprocattr = selinux_setprocattr,
5556
5557 .secid_to_secctx = selinux_secid_to_secctx,
5558 .secctx_to_secid = selinux_secctx_to_secid,
5559 .release_secctx = selinux_release_secctx,
5560 .inode_notifysecctx = selinux_inode_notifysecctx,
5561 .inode_setsecctx = selinux_inode_setsecctx,
5562 .inode_getsecctx = selinux_inode_getsecctx,
5563
5564 .unix_stream_connect = selinux_socket_unix_stream_connect,
5565 .unix_may_send = selinux_socket_unix_may_send,
5566
5567 .socket_create = selinux_socket_create,
5568 .socket_post_create = selinux_socket_post_create,
5569 .socket_bind = selinux_socket_bind,
5570 .socket_connect = selinux_socket_connect,
5571 .socket_listen = selinux_socket_listen,
5572 .socket_accept = selinux_socket_accept,
5573 .socket_sendmsg = selinux_socket_sendmsg,
5574 .socket_recvmsg = selinux_socket_recvmsg,
5575 .socket_getsockname = selinux_socket_getsockname,
5576 .socket_getpeername = selinux_socket_getpeername,
5577 .socket_getsockopt = selinux_socket_getsockopt,
5578 .socket_setsockopt = selinux_socket_setsockopt,
5579 .socket_shutdown = selinux_socket_shutdown,
5580 .socket_sock_rcv_skb = selinux_socket_sock_rcv_skb,
5581 .socket_getpeersec_stream = selinux_socket_getpeersec_stream,
5582 .socket_getpeersec_dgram = selinux_socket_getpeersec_dgram,
5583 .sk_alloc_security = selinux_sk_alloc_security,
5584 .sk_free_security = selinux_sk_free_security,
5585 .sk_clone_security = selinux_sk_clone_security,
5586 .sk_getsecid = selinux_sk_getsecid,
5587 .sock_graft = selinux_sock_graft,
5588 .inet_conn_request = selinux_inet_conn_request,
5589 .inet_csk_clone = selinux_inet_csk_clone,
5590 .inet_conn_established = selinux_inet_conn_established,
5591 .req_classify_flow = selinux_req_classify_flow,
5592 .tun_dev_create = selinux_tun_dev_create,
5593 .tun_dev_post_create = selinux_tun_dev_post_create,
5594 .tun_dev_attach = selinux_tun_dev_attach,
5595
5596 #ifdef CONFIG_SECURITY_NETWORK_XFRM
5597 .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc,
5598 .xfrm_policy_clone_security = selinux_xfrm_policy_clone,
5599 .xfrm_policy_free_security = selinux_xfrm_policy_free,
5600 .xfrm_policy_delete_security = selinux_xfrm_policy_delete,
5601 .xfrm_state_alloc_security = selinux_xfrm_state_alloc,
5602 .xfrm_state_free_security = selinux_xfrm_state_free,
5603 .xfrm_state_delete_security = selinux_xfrm_state_delete,
5604 .xfrm_policy_lookup = selinux_xfrm_policy_lookup,
5605 .xfrm_state_pol_flow_match = selinux_xfrm_state_pol_flow_match,
5606 .xfrm_decode_session = selinux_xfrm_decode_session,
5607 #endif
5608
5609 #ifdef CONFIG_KEYS
5610 .key_alloc = selinux_key_alloc,
5611 .key_free = selinux_key_free,
5612 .key_permission = selinux_key_permission,
5613 .key_getsecurity = selinux_key_getsecurity,
5614 #endif
5615
5616 #ifdef CONFIG_AUDIT
5617 .audit_rule_init = selinux_audit_rule_init,
5618 .audit_rule_known = selinux_audit_rule_known,
5619 .audit_rule_match = selinux_audit_rule_match,
5620 .audit_rule_free = selinux_audit_rule_free,
5621 #endif
5622 };
5623
5624 static __init int selinux_init(void)
5625 {
5626 if (!security_module_enable(&selinux_ops)) {
5627 selinux_enabled = 0;
5628 return 0;
5629 }
5630
5631 if (!selinux_enabled) {
5632 printk(KERN_INFO "SELinux: Disabled at boot.\n");
5633 return 0;
5634 }
5635
5636 printk(KERN_INFO "SELinux: Initializing.\n");
5637
5638 /* Set the security state for the initial task. */
5639 cred_init_security();
5640
5641 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
5642
5643 sel_inode_cache = kmem_cache_create("selinux_inode_security",
5644 sizeof(struct inode_security_struct),
5645 0, SLAB_PANIC, NULL);
5646 avc_init();
5647
5648 if (register_security(&selinux_ops))
5649 panic("SELinux: Unable to register with kernel.\n");
5650
5651 if (selinux_enforcing)
5652 printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n");
5653 else
5654 printk(KERN_DEBUG "SELinux: Starting in permissive mode\n");
5655
5656 return 0;
5657 }
5658
5659 static void delayed_superblock_init(struct super_block *sb, void *unused)
5660 {
5661 superblock_doinit(sb, NULL);
5662 }
5663
5664 void selinux_complete_init(void)
5665 {
5666 printk(KERN_DEBUG "SELinux: Completing initialization.\n");
5667
5668 /* Set up any superblocks initialized prior to the policy load. */
5669 printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n");
5670 iterate_supers(delayed_superblock_init, NULL);
5671 }
5672
5673 /* SELinux requires early initialization in order to label
5674 all processes and objects when they are created. */
5675 security_initcall(selinux_init);
5676
5677 #if defined(CONFIG_NETFILTER)
5678
5679 static struct nf_hook_ops selinux_ipv4_ops[] = {
5680 {
5681 .hook = selinux_ipv4_postroute,
5682 .owner = THIS_MODULE,
5683 .pf = PF_INET,
5684 .hooknum = NF_INET_POST_ROUTING,
5685 .priority = NF_IP_PRI_SELINUX_LAST,
5686 },
5687 {
5688 .hook = selinux_ipv4_forward,
5689 .owner = THIS_MODULE,
5690 .pf = PF_INET,
5691 .hooknum = NF_INET_FORWARD,
5692 .priority = NF_IP_PRI_SELINUX_FIRST,
5693 },
5694 {
5695 .hook = selinux_ipv4_output,
5696 .owner = THIS_MODULE,
5697 .pf = PF_INET,
5698 .hooknum = NF_INET_LOCAL_OUT,
5699 .priority = NF_IP_PRI_SELINUX_FIRST,
5700 }
5701 };
5702
5703 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5704
5705 static struct nf_hook_ops selinux_ipv6_ops[] = {
5706 {
5707 .hook = selinux_ipv6_postroute,
5708 .owner = THIS_MODULE,
5709 .pf = PF_INET6,
5710 .hooknum = NF_INET_POST_ROUTING,
5711 .priority = NF_IP6_PRI_SELINUX_LAST,
5712 },
5713 {
5714 .hook = selinux_ipv6_forward,
5715 .owner = THIS_MODULE,
5716 .pf = PF_INET6,
5717 .hooknum = NF_INET_FORWARD,
5718 .priority = NF_IP6_PRI_SELINUX_FIRST,
5719 }
5720 };
5721
5722 #endif /* IPV6 */
5723
5724 static int __init selinux_nf_ip_init(void)
5725 {
5726 int err = 0;
5727
5728 if (!selinux_enabled)
5729 goto out;
5730
5731 printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n");
5732
5733 err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5734 if (err)
5735 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
5736
5737 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5738 err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5739 if (err)
5740 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
5741 #endif /* IPV6 */
5742
5743 out:
5744 return err;
5745 }
5746
5747 __initcall(selinux_nf_ip_init);
5748
5749 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5750 static void selinux_nf_ip_exit(void)
5751 {
5752 printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n");
5753
5754 nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5755 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5756 nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5757 #endif /* IPV6 */
5758 }
5759 #endif
5760
5761 #else /* CONFIG_NETFILTER */
5762
5763 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5764 #define selinux_nf_ip_exit()
5765 #endif
5766
5767 #endif /* CONFIG_NETFILTER */
5768
5769 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5770 static int selinux_disabled;
5771
5772 int selinux_disable(void)
5773 {
5774 extern void exit_sel_fs(void);
5775
5776 if (ss_initialized) {
5777 /* Not permitted after initial policy load. */
5778 return -EINVAL;
5779 }
5780
5781 if (selinux_disabled) {
5782 /* Only do this once. */
5783 return -EINVAL;
5784 }
5785
5786 printk(KERN_INFO "SELinux: Disabled at runtime.\n");
5787
5788 selinux_disabled = 1;
5789 selinux_enabled = 0;
5790
5791 reset_security_ops();
5792
5793 /* Try to destroy the avc node cache */
5794 avc_disable();
5795
5796 /* Unregister netfilter hooks. */
5797 selinux_nf_ip_exit();
5798
5799 /* Unregister selinuxfs. */
5800 exit_sel_fs();
5801
5802 return 0;
5803 }
5804 #endif
Linux kernel - Deliverables
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