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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[mirror_ubuntu-bionic-kernel.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 NUM_SEL_MNT_OPTS 5
91
92 extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
93 extern struct security_operations *security_ops;
94
95 /* SECMARK reference count */
96 atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
97
98 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
99 int selinux_enforcing;
100
101 static int __init enforcing_setup(char *str)
102 {
103 unsigned long enforcing;
104 if (!strict_strtoul(str, 0, &enforcing))
105 selinux_enforcing = enforcing ? 1 : 0;
106 return 1;
107 }
108 __setup("enforcing=", enforcing_setup);
109 #endif
110
111 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
112 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
113
114 static int __init selinux_enabled_setup(char *str)
115 {
116 unsigned long enabled;
117 if (!strict_strtoul(str, 0, &enabled))
118 selinux_enabled = enabled ? 1 : 0;
119 return 1;
120 }
121 __setup("selinux=", selinux_enabled_setup);
122 #else
123 int selinux_enabled = 1;
124 #endif
125
126 static struct kmem_cache *sel_inode_cache;
127
128 /**
129 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
130 *
131 * Description:
132 * This function checks the SECMARK reference counter to see if any SECMARK
133 * targets are currently configured, if the reference counter is greater than
134 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is
135 * enabled, false (0) if SECMARK is disabled.
136 *
137 */
138 static int selinux_secmark_enabled(void)
139 {
140 return (atomic_read(&selinux_secmark_refcount) > 0);
141 }
142
143 /*
144 * initialise the security for the init task
145 */
146 static void cred_init_security(void)
147 {
148 struct cred *cred = (struct cred *) current->real_cred;
149 struct task_security_struct *tsec;
150
151 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
152 if (!tsec)
153 panic("SELinux: Failed to initialize initial task.\n");
154
155 tsec->osid = tsec->sid = SECINITSID_KERNEL;
156 cred->security = tsec;
157 }
158
159 /*
160 * get the security ID of a set of credentials
161 */
162 static inline u32 cred_sid(const struct cred *cred)
163 {
164 const struct task_security_struct *tsec;
165
166 tsec = cred->security;
167 return tsec->sid;
168 }
169
170 /*
171 * get the objective security ID of a task
172 */
173 static inline u32 task_sid(const struct task_struct *task)
174 {
175 u32 sid;
176
177 rcu_read_lock();
178 sid = cred_sid(__task_cred(task));
179 rcu_read_unlock();
180 return sid;
181 }
182
183 /*
184 * get the subjective security ID of the current task
185 */
186 static inline u32 current_sid(void)
187 {
188 const struct task_security_struct *tsec = current_security();
189
190 return tsec->sid;
191 }
192
193 /* Allocate and free functions for each kind of security blob. */
194
195 static int inode_alloc_security(struct inode *inode)
196 {
197 struct inode_security_struct *isec;
198 u32 sid = current_sid();
199
200 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
201 if (!isec)
202 return -ENOMEM;
203
204 mutex_init(&isec->lock);
205 INIT_LIST_HEAD(&isec->list);
206 isec->inode = inode;
207 isec->sid = SECINITSID_UNLABELED;
208 isec->sclass = SECCLASS_FILE;
209 isec->task_sid = sid;
210 inode->i_security = isec;
211
212 return 0;
213 }
214
215 static void inode_free_security(struct inode *inode)
216 {
217 struct inode_security_struct *isec = inode->i_security;
218 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
219
220 spin_lock(&sbsec->isec_lock);
221 if (!list_empty(&isec->list))
222 list_del_init(&isec->list);
223 spin_unlock(&sbsec->isec_lock);
224
225 inode->i_security = NULL;
226 kmem_cache_free(sel_inode_cache, isec);
227 }
228
229 static int file_alloc_security(struct file *file)
230 {
231 struct file_security_struct *fsec;
232 u32 sid = current_sid();
233
234 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
235 if (!fsec)
236 return -ENOMEM;
237
238 fsec->sid = sid;
239 fsec->fown_sid = sid;
240 file->f_security = fsec;
241
242 return 0;
243 }
244
245 static void file_free_security(struct file *file)
246 {
247 struct file_security_struct *fsec = file->f_security;
248 file->f_security = NULL;
249 kfree(fsec);
250 }
251
252 static int superblock_alloc_security(struct super_block *sb)
253 {
254 struct superblock_security_struct *sbsec;
255
256 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
257 if (!sbsec)
258 return -ENOMEM;
259
260 mutex_init(&sbsec->lock);
261 INIT_LIST_HEAD(&sbsec->isec_head);
262 spin_lock_init(&sbsec->isec_lock);
263 sbsec->sb = sb;
264 sbsec->sid = SECINITSID_UNLABELED;
265 sbsec->def_sid = SECINITSID_FILE;
266 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
267 sb->s_security = sbsec;
268
269 return 0;
270 }
271
272 static void superblock_free_security(struct super_block *sb)
273 {
274 struct superblock_security_struct *sbsec = sb->s_security;
275 sb->s_security = NULL;
276 kfree(sbsec);
277 }
278
279 /* The security server must be initialized before
280 any labeling or access decisions can be provided. */
281 extern int ss_initialized;
282
283 /* The file system's label must be initialized prior to use. */
284
285 static const char *labeling_behaviors[6] = {
286 "uses xattr",
287 "uses transition SIDs",
288 "uses task SIDs",
289 "uses genfs_contexts",
290 "not configured for labeling",
291 "uses mountpoint labeling",
292 };
293
294 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
295
296 static inline int inode_doinit(struct inode *inode)
297 {
298 return inode_doinit_with_dentry(inode, NULL);
299 }
300
301 enum {
302 Opt_error = -1,
303 Opt_context = 1,
304 Opt_fscontext = 2,
305 Opt_defcontext = 3,
306 Opt_rootcontext = 4,
307 Opt_labelsupport = 5,
308 };
309
310 static const match_table_t tokens = {
311 {Opt_context, CONTEXT_STR "%s"},
312 {Opt_fscontext, FSCONTEXT_STR "%s"},
313 {Opt_defcontext, DEFCONTEXT_STR "%s"},
314 {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
315 {Opt_labelsupport, LABELSUPP_STR},
316 {Opt_error, NULL},
317 };
318
319 #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
320
321 static int may_context_mount_sb_relabel(u32 sid,
322 struct superblock_security_struct *sbsec,
323 const struct cred *cred)
324 {
325 const struct task_security_struct *tsec = cred->security;
326 int rc;
327
328 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
329 FILESYSTEM__RELABELFROM, NULL);
330 if (rc)
331 return rc;
332
333 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
334 FILESYSTEM__RELABELTO, NULL);
335 return rc;
336 }
337
338 static int may_context_mount_inode_relabel(u32 sid,
339 struct superblock_security_struct *sbsec,
340 const struct cred *cred)
341 {
342 const struct task_security_struct *tsec = cred->security;
343 int rc;
344 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
345 FILESYSTEM__RELABELFROM, NULL);
346 if (rc)
347 return rc;
348
349 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
350 FILESYSTEM__ASSOCIATE, NULL);
351 return rc;
352 }
353
354 static int sb_finish_set_opts(struct super_block *sb)
355 {
356 struct superblock_security_struct *sbsec = sb->s_security;
357 struct dentry *root = sb->s_root;
358 struct inode *root_inode = root->d_inode;
359 int rc = 0;
360
361 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
362 /* Make sure that the xattr handler exists and that no
363 error other than -ENODATA is returned by getxattr on
364 the root directory. -ENODATA is ok, as this may be
365 the first boot of the SELinux kernel before we have
366 assigned xattr values to the filesystem. */
367 if (!root_inode->i_op->getxattr) {
368 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
369 "xattr support\n", sb->s_id, sb->s_type->name);
370 rc = -EOPNOTSUPP;
371 goto out;
372 }
373 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
374 if (rc < 0 && rc != -ENODATA) {
375 if (rc == -EOPNOTSUPP)
376 printk(KERN_WARNING "SELinux: (dev %s, type "
377 "%s) has no security xattr handler\n",
378 sb->s_id, sb->s_type->name);
379 else
380 printk(KERN_WARNING "SELinux: (dev %s, type "
381 "%s) getxattr errno %d\n", sb->s_id,
382 sb->s_type->name, -rc);
383 goto out;
384 }
385 }
386
387 sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
388
389 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
390 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
391 sb->s_id, sb->s_type->name);
392 else
393 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
394 sb->s_id, sb->s_type->name,
395 labeling_behaviors[sbsec->behavior-1]);
396
397 if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
398 sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
399 sbsec->behavior == SECURITY_FS_USE_NONE ||
400 sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
401 sbsec->flags &= ~SE_SBLABELSUPP;
402
403 /* Special handling for sysfs. Is genfs but also has setxattr handler*/
404 if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
405 sbsec->flags |= SE_SBLABELSUPP;
406
407 /* Initialize the root inode. */
408 rc = inode_doinit_with_dentry(root_inode, root);
409
410 /* Initialize any other inodes associated with the superblock, e.g.
411 inodes created prior to initial policy load or inodes created
412 during get_sb by a pseudo filesystem that directly
413 populates itself. */
414 spin_lock(&sbsec->isec_lock);
415 next_inode:
416 if (!list_empty(&sbsec->isec_head)) {
417 struct inode_security_struct *isec =
418 list_entry(sbsec->isec_head.next,
419 struct inode_security_struct, list);
420 struct inode *inode = isec->inode;
421 spin_unlock(&sbsec->isec_lock);
422 inode = igrab(inode);
423 if (inode) {
424 if (!IS_PRIVATE(inode))
425 inode_doinit(inode);
426 iput(inode);
427 }
428 spin_lock(&sbsec->isec_lock);
429 list_del_init(&isec->list);
430 goto next_inode;
431 }
432 spin_unlock(&sbsec->isec_lock);
433 out:
434 return rc;
435 }
436
437 /*
438 * This function should allow an FS to ask what it's mount security
439 * options were so it can use those later for submounts, displaying
440 * mount options, or whatever.
441 */
442 static int selinux_get_mnt_opts(const struct super_block *sb,
443 struct security_mnt_opts *opts)
444 {
445 int rc = 0, i;
446 struct superblock_security_struct *sbsec = sb->s_security;
447 char *context = NULL;
448 u32 len;
449 char tmp;
450
451 security_init_mnt_opts(opts);
452
453 if (!(sbsec->flags & SE_SBINITIALIZED))
454 return -EINVAL;
455
456 if (!ss_initialized)
457 return -EINVAL;
458
459 tmp = sbsec->flags & SE_MNTMASK;
460 /* count the number of mount options for this sb */
461 for (i = 0; i < 8; i++) {
462 if (tmp & 0x01)
463 opts->num_mnt_opts++;
464 tmp >>= 1;
465 }
466 /* Check if the Label support flag is set */
467 if (sbsec->flags & SE_SBLABELSUPP)
468 opts->num_mnt_opts++;
469
470 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
471 if (!opts->mnt_opts) {
472 rc = -ENOMEM;
473 goto out_free;
474 }
475
476 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
477 if (!opts->mnt_opts_flags) {
478 rc = -ENOMEM;
479 goto out_free;
480 }
481
482 i = 0;
483 if (sbsec->flags & FSCONTEXT_MNT) {
484 rc = security_sid_to_context(sbsec->sid, &context, &len);
485 if (rc)
486 goto out_free;
487 opts->mnt_opts[i] = context;
488 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
489 }
490 if (sbsec->flags & CONTEXT_MNT) {
491 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
492 if (rc)
493 goto out_free;
494 opts->mnt_opts[i] = context;
495 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
496 }
497 if (sbsec->flags & DEFCONTEXT_MNT) {
498 rc = security_sid_to_context(sbsec->def_sid, &context, &len);
499 if (rc)
500 goto out_free;
501 opts->mnt_opts[i] = context;
502 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
503 }
504 if (sbsec->flags & ROOTCONTEXT_MNT) {
505 struct inode *root = sbsec->sb->s_root->d_inode;
506 struct inode_security_struct *isec = root->i_security;
507
508 rc = security_sid_to_context(isec->sid, &context, &len);
509 if (rc)
510 goto out_free;
511 opts->mnt_opts[i] = context;
512 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
513 }
514 if (sbsec->flags & SE_SBLABELSUPP) {
515 opts->mnt_opts[i] = NULL;
516 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
517 }
518
519 BUG_ON(i != opts->num_mnt_opts);
520
521 return 0;
522
523 out_free:
524 security_free_mnt_opts(opts);
525 return rc;
526 }
527
528 static int bad_option(struct superblock_security_struct *sbsec, char flag,
529 u32 old_sid, u32 new_sid)
530 {
531 char mnt_flags = sbsec->flags & SE_MNTMASK;
532
533 /* check if the old mount command had the same options */
534 if (sbsec->flags & SE_SBINITIALIZED)
535 if (!(sbsec->flags & flag) ||
536 (old_sid != new_sid))
537 return 1;
538
539 /* check if we were passed the same options twice,
540 * aka someone passed context=a,context=b
541 */
542 if (!(sbsec->flags & SE_SBINITIALIZED))
543 if (mnt_flags & flag)
544 return 1;
545 return 0;
546 }
547
548 /*
549 * Allow filesystems with binary mount data to explicitly set mount point
550 * labeling information.
551 */
552 static int selinux_set_mnt_opts(struct super_block *sb,
553 struct security_mnt_opts *opts)
554 {
555 const struct cred *cred = current_cred();
556 int rc = 0, i;
557 struct superblock_security_struct *sbsec = sb->s_security;
558 const char *name = sb->s_type->name;
559 struct inode *inode = sbsec->sb->s_root->d_inode;
560 struct inode_security_struct *root_isec = inode->i_security;
561 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
562 u32 defcontext_sid = 0;
563 char **mount_options = opts->mnt_opts;
564 int *flags = opts->mnt_opts_flags;
565 int num_opts = opts->num_mnt_opts;
566
567 mutex_lock(&sbsec->lock);
568
569 if (!ss_initialized) {
570 if (!num_opts) {
571 /* Defer initialization until selinux_complete_init,
572 after the initial policy is loaded and the security
573 server is ready to handle calls. */
574 goto out;
575 }
576 rc = -EINVAL;
577 printk(KERN_WARNING "SELinux: Unable to set superblock options "
578 "before the security server is initialized\n");
579 goto out;
580 }
581
582 /*
583 * Binary mount data FS will come through this function twice. Once
584 * from an explicit call and once from the generic calls from the vfs.
585 * Since the generic VFS calls will not contain any security mount data
586 * we need to skip the double mount verification.
587 *
588 * This does open a hole in which we will not notice if the first
589 * mount using this sb set explict options and a second mount using
590 * this sb does not set any security options. (The first options
591 * will be used for both mounts)
592 */
593 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
594 && (num_opts == 0))
595 goto out;
596
597 /*
598 * parse the mount options, check if they are valid sids.
599 * also check if someone is trying to mount the same sb more
600 * than once with different security options.
601 */
602 for (i = 0; i < num_opts; i++) {
603 u32 sid;
604
605 if (flags[i] == SE_SBLABELSUPP)
606 continue;
607 rc = security_context_to_sid(mount_options[i],
608 strlen(mount_options[i]), &sid);
609 if (rc) {
610 printk(KERN_WARNING "SELinux: security_context_to_sid"
611 "(%s) failed for (dev %s, type %s) errno=%d\n",
612 mount_options[i], sb->s_id, name, rc);
613 goto out;
614 }
615 switch (flags[i]) {
616 case FSCONTEXT_MNT:
617 fscontext_sid = sid;
618
619 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
620 fscontext_sid))
621 goto out_double_mount;
622
623 sbsec->flags |= FSCONTEXT_MNT;
624 break;
625 case CONTEXT_MNT:
626 context_sid = sid;
627
628 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
629 context_sid))
630 goto out_double_mount;
631
632 sbsec->flags |= CONTEXT_MNT;
633 break;
634 case ROOTCONTEXT_MNT:
635 rootcontext_sid = sid;
636
637 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
638 rootcontext_sid))
639 goto out_double_mount;
640
641 sbsec->flags |= ROOTCONTEXT_MNT;
642
643 break;
644 case DEFCONTEXT_MNT:
645 defcontext_sid = sid;
646
647 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
648 defcontext_sid))
649 goto out_double_mount;
650
651 sbsec->flags |= DEFCONTEXT_MNT;
652
653 break;
654 default:
655 rc = -EINVAL;
656 goto out;
657 }
658 }
659
660 if (sbsec->flags & SE_SBINITIALIZED) {
661 /* previously mounted with options, but not on this attempt? */
662 if ((sbsec->flags & SE_MNTMASK) && !num_opts)
663 goto out_double_mount;
664 rc = 0;
665 goto out;
666 }
667
668 if (strcmp(sb->s_type->name, "proc") == 0)
669 sbsec->flags |= SE_SBPROC;
670
671 /* Determine the labeling behavior to use for this filesystem type. */
672 rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
673 if (rc) {
674 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
675 __func__, sb->s_type->name, rc);
676 goto out;
677 }
678
679 /* sets the context of the superblock for the fs being mounted. */
680 if (fscontext_sid) {
681 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
682 if (rc)
683 goto out;
684
685 sbsec->sid = fscontext_sid;
686 }
687
688 /*
689 * Switch to using mount point labeling behavior.
690 * sets the label used on all file below the mountpoint, and will set
691 * the superblock context if not already set.
692 */
693 if (context_sid) {
694 if (!fscontext_sid) {
695 rc = may_context_mount_sb_relabel(context_sid, sbsec,
696 cred);
697 if (rc)
698 goto out;
699 sbsec->sid = context_sid;
700 } else {
701 rc = may_context_mount_inode_relabel(context_sid, sbsec,
702 cred);
703 if (rc)
704 goto out;
705 }
706 if (!rootcontext_sid)
707 rootcontext_sid = context_sid;
708
709 sbsec->mntpoint_sid = context_sid;
710 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
711 }
712
713 if (rootcontext_sid) {
714 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
715 cred);
716 if (rc)
717 goto out;
718
719 root_isec->sid = rootcontext_sid;
720 root_isec->initialized = 1;
721 }
722
723 if (defcontext_sid) {
724 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
725 rc = -EINVAL;
726 printk(KERN_WARNING "SELinux: defcontext option is "
727 "invalid for this filesystem type\n");
728 goto out;
729 }
730
731 if (defcontext_sid != sbsec->def_sid) {
732 rc = may_context_mount_inode_relabel(defcontext_sid,
733 sbsec, cred);
734 if (rc)
735 goto out;
736 }
737
738 sbsec->def_sid = defcontext_sid;
739 }
740
741 rc = sb_finish_set_opts(sb);
742 out:
743 mutex_unlock(&sbsec->lock);
744 return rc;
745 out_double_mount:
746 rc = -EINVAL;
747 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different "
748 "security settings for (dev %s, type %s)\n", sb->s_id, name);
749 goto out;
750 }
751
752 static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
753 struct super_block *newsb)
754 {
755 const struct superblock_security_struct *oldsbsec = oldsb->s_security;
756 struct superblock_security_struct *newsbsec = newsb->s_security;
757
758 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
759 int set_context = (oldsbsec->flags & CONTEXT_MNT);
760 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
761
762 /*
763 * if the parent was able to be mounted it clearly had no special lsm
764 * mount options. thus we can safely deal with this superblock later
765 */
766 if (!ss_initialized)
767 return;
768
769 /* how can we clone if the old one wasn't set up?? */
770 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
771
772 /* if fs is reusing a sb, just let its options stand... */
773 if (newsbsec->flags & SE_SBINITIALIZED)
774 return;
775
776 mutex_lock(&newsbsec->lock);
777
778 newsbsec->flags = oldsbsec->flags;
779
780 newsbsec->sid = oldsbsec->sid;
781 newsbsec->def_sid = oldsbsec->def_sid;
782 newsbsec->behavior = oldsbsec->behavior;
783
784 if (set_context) {
785 u32 sid = oldsbsec->mntpoint_sid;
786
787 if (!set_fscontext)
788 newsbsec->sid = sid;
789 if (!set_rootcontext) {
790 struct inode *newinode = newsb->s_root->d_inode;
791 struct inode_security_struct *newisec = newinode->i_security;
792 newisec->sid = sid;
793 }
794 newsbsec->mntpoint_sid = sid;
795 }
796 if (set_rootcontext) {
797 const struct inode *oldinode = oldsb->s_root->d_inode;
798 const struct inode_security_struct *oldisec = oldinode->i_security;
799 struct inode *newinode = newsb->s_root->d_inode;
800 struct inode_security_struct *newisec = newinode->i_security;
801
802 newisec->sid = oldisec->sid;
803 }
804
805 sb_finish_set_opts(newsb);
806 mutex_unlock(&newsbsec->lock);
807 }
808
809 static int selinux_parse_opts_str(char *options,
810 struct security_mnt_opts *opts)
811 {
812 char *p;
813 char *context = NULL, *defcontext = NULL;
814 char *fscontext = NULL, *rootcontext = NULL;
815 int rc, num_mnt_opts = 0;
816
817 opts->num_mnt_opts = 0;
818
819 /* Standard string-based options. */
820 while ((p = strsep(&options, "|")) != NULL) {
821 int token;
822 substring_t args[MAX_OPT_ARGS];
823
824 if (!*p)
825 continue;
826
827 token = match_token(p, tokens, args);
828
829 switch (token) {
830 case Opt_context:
831 if (context || defcontext) {
832 rc = -EINVAL;
833 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
834 goto out_err;
835 }
836 context = match_strdup(&args[0]);
837 if (!context) {
838 rc = -ENOMEM;
839 goto out_err;
840 }
841 break;
842
843 case Opt_fscontext:
844 if (fscontext) {
845 rc = -EINVAL;
846 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
847 goto out_err;
848 }
849 fscontext = match_strdup(&args[0]);
850 if (!fscontext) {
851 rc = -ENOMEM;
852 goto out_err;
853 }
854 break;
855
856 case Opt_rootcontext:
857 if (rootcontext) {
858 rc = -EINVAL;
859 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
860 goto out_err;
861 }
862 rootcontext = match_strdup(&args[0]);
863 if (!rootcontext) {
864 rc = -ENOMEM;
865 goto out_err;
866 }
867 break;
868
869 case Opt_defcontext:
870 if (context || defcontext) {
871 rc = -EINVAL;
872 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
873 goto out_err;
874 }
875 defcontext = match_strdup(&args[0]);
876 if (!defcontext) {
877 rc = -ENOMEM;
878 goto out_err;
879 }
880 break;
881 case Opt_labelsupport:
882 break;
883 default:
884 rc = -EINVAL;
885 printk(KERN_WARNING "SELinux: unknown mount option\n");
886 goto out_err;
887
888 }
889 }
890
891 rc = -ENOMEM;
892 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
893 if (!opts->mnt_opts)
894 goto out_err;
895
896 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
897 if (!opts->mnt_opts_flags) {
898 kfree(opts->mnt_opts);
899 goto out_err;
900 }
901
902 if (fscontext) {
903 opts->mnt_opts[num_mnt_opts] = fscontext;
904 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
905 }
906 if (context) {
907 opts->mnt_opts[num_mnt_opts] = context;
908 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
909 }
910 if (rootcontext) {
911 opts->mnt_opts[num_mnt_opts] = rootcontext;
912 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
913 }
914 if (defcontext) {
915 opts->mnt_opts[num_mnt_opts] = defcontext;
916 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
917 }
918
919 opts->num_mnt_opts = num_mnt_opts;
920 return 0;
921
922 out_err:
923 kfree(context);
924 kfree(defcontext);
925 kfree(fscontext);
926 kfree(rootcontext);
927 return rc;
928 }
929 /*
930 * string mount options parsing and call set the sbsec
931 */
932 static int superblock_doinit(struct super_block *sb, void *data)
933 {
934 int rc = 0;
935 char *options = data;
936 struct security_mnt_opts opts;
937
938 security_init_mnt_opts(&opts);
939
940 if (!data)
941 goto out;
942
943 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
944
945 rc = selinux_parse_opts_str(options, &opts);
946 if (rc)
947 goto out_err;
948
949 out:
950 rc = selinux_set_mnt_opts(sb, &opts);
951
952 out_err:
953 security_free_mnt_opts(&opts);
954 return rc;
955 }
956
957 static void selinux_write_opts(struct seq_file *m,
958 struct security_mnt_opts *opts)
959 {
960 int i;
961 char *prefix;
962
963 for (i = 0; i < opts->num_mnt_opts; i++) {
964 char *has_comma;
965
966 if (opts->mnt_opts[i])
967 has_comma = strchr(opts->mnt_opts[i], ',');
968 else
969 has_comma = NULL;
970
971 switch (opts->mnt_opts_flags[i]) {
972 case CONTEXT_MNT:
973 prefix = CONTEXT_STR;
974 break;
975 case FSCONTEXT_MNT:
976 prefix = FSCONTEXT_STR;
977 break;
978 case ROOTCONTEXT_MNT:
979 prefix = ROOTCONTEXT_STR;
980 break;
981 case DEFCONTEXT_MNT:
982 prefix = DEFCONTEXT_STR;
983 break;
984 case SE_SBLABELSUPP:
985 seq_putc(m, ',');
986 seq_puts(m, LABELSUPP_STR);
987 continue;
988 default:
989 BUG();
990 };
991 /* we need a comma before each option */
992 seq_putc(m, ',');
993 seq_puts(m, prefix);
994 if (has_comma)
995 seq_putc(m, '\"');
996 seq_puts(m, opts->mnt_opts[i]);
997 if (has_comma)
998 seq_putc(m, '\"');
999 }
1000 }
1001
1002 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1003 {
1004 struct security_mnt_opts opts;
1005 int rc;
1006
1007 rc = selinux_get_mnt_opts(sb, &opts);
1008 if (rc) {
1009 /* before policy load we may get EINVAL, don't show anything */
1010 if (rc == -EINVAL)
1011 rc = 0;
1012 return rc;
1013 }
1014
1015 selinux_write_opts(m, &opts);
1016
1017 security_free_mnt_opts(&opts);
1018
1019 return rc;
1020 }
1021
1022 static inline u16 inode_mode_to_security_class(umode_t mode)
1023 {
1024 switch (mode & S_IFMT) {
1025 case S_IFSOCK:
1026 return SECCLASS_SOCK_FILE;
1027 case S_IFLNK:
1028 return SECCLASS_LNK_FILE;
1029 case S_IFREG:
1030 return SECCLASS_FILE;
1031 case S_IFBLK:
1032 return SECCLASS_BLK_FILE;
1033 case S_IFDIR:
1034 return SECCLASS_DIR;
1035 case S_IFCHR:
1036 return SECCLASS_CHR_FILE;
1037 case S_IFIFO:
1038 return SECCLASS_FIFO_FILE;
1039
1040 }
1041
1042 return SECCLASS_FILE;
1043 }
1044
1045 static inline int default_protocol_stream(int protocol)
1046 {
1047 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1048 }
1049
1050 static inline int default_protocol_dgram(int protocol)
1051 {
1052 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1053 }
1054
1055 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1056 {
1057 switch (family) {
1058 case PF_UNIX:
1059 switch (type) {
1060 case SOCK_STREAM:
1061 case SOCK_SEQPACKET:
1062 return SECCLASS_UNIX_STREAM_SOCKET;
1063 case SOCK_DGRAM:
1064 return SECCLASS_UNIX_DGRAM_SOCKET;
1065 }
1066 break;
1067 case PF_INET:
1068 case PF_INET6:
1069 switch (type) {
1070 case SOCK_STREAM:
1071 if (default_protocol_stream(protocol))
1072 return SECCLASS_TCP_SOCKET;
1073 else
1074 return SECCLASS_RAWIP_SOCKET;
1075 case SOCK_DGRAM:
1076 if (default_protocol_dgram(protocol))
1077 return SECCLASS_UDP_SOCKET;
1078 else
1079 return SECCLASS_RAWIP_SOCKET;
1080 case SOCK_DCCP:
1081 return SECCLASS_DCCP_SOCKET;
1082 default:
1083 return SECCLASS_RAWIP_SOCKET;
1084 }
1085 break;
1086 case PF_NETLINK:
1087 switch (protocol) {
1088 case NETLINK_ROUTE:
1089 return SECCLASS_NETLINK_ROUTE_SOCKET;
1090 case NETLINK_FIREWALL:
1091 return SECCLASS_NETLINK_FIREWALL_SOCKET;
1092 case NETLINK_INET_DIAG:
1093 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1094 case NETLINK_NFLOG:
1095 return SECCLASS_NETLINK_NFLOG_SOCKET;
1096 case NETLINK_XFRM:
1097 return SECCLASS_NETLINK_XFRM_SOCKET;
1098 case NETLINK_SELINUX:
1099 return SECCLASS_NETLINK_SELINUX_SOCKET;
1100 case NETLINK_AUDIT:
1101 return SECCLASS_NETLINK_AUDIT_SOCKET;
1102 case NETLINK_IP6_FW:
1103 return SECCLASS_NETLINK_IP6FW_SOCKET;
1104 case NETLINK_DNRTMSG:
1105 return SECCLASS_NETLINK_DNRT_SOCKET;
1106 case NETLINK_KOBJECT_UEVENT:
1107 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1108 default:
1109 return SECCLASS_NETLINK_SOCKET;
1110 }
1111 case PF_PACKET:
1112 return SECCLASS_PACKET_SOCKET;
1113 case PF_KEY:
1114 return SECCLASS_KEY_SOCKET;
1115 case PF_APPLETALK:
1116 return SECCLASS_APPLETALK_SOCKET;
1117 }
1118
1119 return SECCLASS_SOCKET;
1120 }
1121
1122 #ifdef CONFIG_PROC_FS
1123 static int selinux_proc_get_sid(struct proc_dir_entry *de,
1124 u16 tclass,
1125 u32 *sid)
1126 {
1127 int buflen, rc;
1128 char *buffer, *path, *end;
1129
1130 buffer = (char *)__get_free_page(GFP_KERNEL);
1131 if (!buffer)
1132 return -ENOMEM;
1133
1134 buflen = PAGE_SIZE;
1135 end = buffer+buflen;
1136 *--end = '\0';
1137 buflen--;
1138 path = end-1;
1139 *path = '/';
1140 while (de && de != de->parent) {
1141 buflen -= de->namelen + 1;
1142 if (buflen < 0)
1143 break;
1144 end -= de->namelen;
1145 memcpy(end, de->name, de->namelen);
1146 *--end = '/';
1147 path = end;
1148 de = de->parent;
1149 }
1150 rc = security_genfs_sid("proc", path, tclass, sid);
1151 free_page((unsigned long)buffer);
1152 return rc;
1153 }
1154 #else
1155 static int selinux_proc_get_sid(struct proc_dir_entry *de,
1156 u16 tclass,
1157 u32 *sid)
1158 {
1159 return -EINVAL;
1160 }
1161 #endif
1162
1163 /* The inode's security attributes must be initialized before first use. */
1164 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1165 {
1166 struct superblock_security_struct *sbsec = NULL;
1167 struct inode_security_struct *isec = inode->i_security;
1168 u32 sid;
1169 struct dentry *dentry;
1170 #define INITCONTEXTLEN 255
1171 char *context = NULL;
1172 unsigned len = 0;
1173 int rc = 0;
1174
1175 if (isec->initialized)
1176 goto out;
1177
1178 mutex_lock(&isec->lock);
1179 if (isec->initialized)
1180 goto out_unlock;
1181
1182 sbsec = inode->i_sb->s_security;
1183 if (!(sbsec->flags & SE_SBINITIALIZED)) {
1184 /* Defer initialization until selinux_complete_init,
1185 after the initial policy is loaded and the security
1186 server is ready to handle calls. */
1187 spin_lock(&sbsec->isec_lock);
1188 if (list_empty(&isec->list))
1189 list_add(&isec->list, &sbsec->isec_head);
1190 spin_unlock(&sbsec->isec_lock);
1191 goto out_unlock;
1192 }
1193
1194 switch (sbsec->behavior) {
1195 case SECURITY_FS_USE_XATTR:
1196 if (!inode->i_op->getxattr) {
1197 isec->sid = sbsec->def_sid;
1198 break;
1199 }
1200
1201 /* Need a dentry, since the xattr API requires one.
1202 Life would be simpler if we could just pass the inode. */
1203 if (opt_dentry) {
1204 /* Called from d_instantiate or d_splice_alias. */
1205 dentry = dget(opt_dentry);
1206 } else {
1207 /* Called from selinux_complete_init, try to find a dentry. */
1208 dentry = d_find_alias(inode);
1209 }
1210 if (!dentry) {
1211 /*
1212 * this is can be hit on boot when a file is accessed
1213 * before the policy is loaded. When we load policy we
1214 * may find inodes that have no dentry on the
1215 * sbsec->isec_head list. No reason to complain as these
1216 * will get fixed up the next time we go through
1217 * inode_doinit with a dentry, before these inodes could
1218 * be used again by userspace.
1219 */
1220 goto out_unlock;
1221 }
1222
1223 len = INITCONTEXTLEN;
1224 context = kmalloc(len+1, GFP_NOFS);
1225 if (!context) {
1226 rc = -ENOMEM;
1227 dput(dentry);
1228 goto out_unlock;
1229 }
1230 context[len] = '\0';
1231 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1232 context, len);
1233 if (rc == -ERANGE) {
1234 kfree(context);
1235
1236 /* Need a larger buffer. Query for the right size. */
1237 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1238 NULL, 0);
1239 if (rc < 0) {
1240 dput(dentry);
1241 goto out_unlock;
1242 }
1243 len = rc;
1244 context = kmalloc(len+1, GFP_NOFS);
1245 if (!context) {
1246 rc = -ENOMEM;
1247 dput(dentry);
1248 goto out_unlock;
1249 }
1250 context[len] = '\0';
1251 rc = inode->i_op->getxattr(dentry,
1252 XATTR_NAME_SELINUX,
1253 context, len);
1254 }
1255 dput(dentry);
1256 if (rc < 0) {
1257 if (rc != -ENODATA) {
1258 printk(KERN_WARNING "SELinux: %s: getxattr returned "
1259 "%d for dev=%s ino=%ld\n", __func__,
1260 -rc, inode->i_sb->s_id, inode->i_ino);
1261 kfree(context);
1262 goto out_unlock;
1263 }
1264 /* Map ENODATA to the default file SID */
1265 sid = sbsec->def_sid;
1266 rc = 0;
1267 } else {
1268 rc = security_context_to_sid_default(context, rc, &sid,
1269 sbsec->def_sid,
1270 GFP_NOFS);
1271 if (rc) {
1272 char *dev = inode->i_sb->s_id;
1273 unsigned long ino = inode->i_ino;
1274
1275 if (rc == -EINVAL) {
1276 if (printk_ratelimit())
1277 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
1278 "context=%s. This indicates you may need to relabel the inode or the "
1279 "filesystem in question.\n", ino, dev, context);
1280 } else {
1281 printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) "
1282 "returned %d for dev=%s ino=%ld\n",
1283 __func__, context, -rc, dev, ino);
1284 }
1285 kfree(context);
1286 /* Leave with the unlabeled SID */
1287 rc = 0;
1288 break;
1289 }
1290 }
1291 kfree(context);
1292 isec->sid = sid;
1293 break;
1294 case SECURITY_FS_USE_TASK:
1295 isec->sid = isec->task_sid;
1296 break;
1297 case SECURITY_FS_USE_TRANS:
1298 /* Default to the fs SID. */
1299 isec->sid = sbsec->sid;
1300
1301 /* Try to obtain a transition SID. */
1302 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1303 rc = security_transition_sid(isec->task_sid,
1304 sbsec->sid,
1305 isec->sclass,
1306 &sid);
1307 if (rc)
1308 goto out_unlock;
1309 isec->sid = sid;
1310 break;
1311 case SECURITY_FS_USE_MNTPOINT:
1312 isec->sid = sbsec->mntpoint_sid;
1313 break;
1314 default:
1315 /* Default to the fs superblock SID. */
1316 isec->sid = sbsec->sid;
1317
1318 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
1319 struct proc_inode *proci = PROC_I(inode);
1320 if (proci->pde) {
1321 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1322 rc = selinux_proc_get_sid(proci->pde,
1323 isec->sclass,
1324 &sid);
1325 if (rc)
1326 goto out_unlock;
1327 isec->sid = sid;
1328 }
1329 }
1330 break;
1331 }
1332
1333 isec->initialized = 1;
1334
1335 out_unlock:
1336 mutex_unlock(&isec->lock);
1337 out:
1338 if (isec->sclass == SECCLASS_FILE)
1339 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1340 return rc;
1341 }
1342
1343 /* Convert a Linux signal to an access vector. */
1344 static inline u32 signal_to_av(int sig)
1345 {
1346 u32 perm = 0;
1347
1348 switch (sig) {
1349 case SIGCHLD:
1350 /* Commonly granted from child to parent. */
1351 perm = PROCESS__SIGCHLD;
1352 break;
1353 case SIGKILL:
1354 /* Cannot be caught or ignored */
1355 perm = PROCESS__SIGKILL;
1356 break;
1357 case SIGSTOP:
1358 /* Cannot be caught or ignored */
1359 perm = PROCESS__SIGSTOP;
1360 break;
1361 default:
1362 /* All other signals. */
1363 perm = PROCESS__SIGNAL;
1364 break;
1365 }
1366
1367 return perm;
1368 }
1369
1370 /*
1371 * Check permission between a pair of credentials
1372 * fork check, ptrace check, etc.
1373 */
1374 static int cred_has_perm(const struct cred *actor,
1375 const struct cred *target,
1376 u32 perms)
1377 {
1378 u32 asid = cred_sid(actor), tsid = cred_sid(target);
1379
1380 return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1381 }
1382
1383 /*
1384 * Check permission between a pair of tasks, e.g. signal checks,
1385 * fork check, ptrace check, etc.
1386 * tsk1 is the actor and tsk2 is the target
1387 * - this uses the default subjective creds of tsk1
1388 */
1389 static int task_has_perm(const struct task_struct *tsk1,
1390 const struct task_struct *tsk2,
1391 u32 perms)
1392 {
1393 const struct task_security_struct *__tsec1, *__tsec2;
1394 u32 sid1, sid2;
1395
1396 rcu_read_lock();
1397 __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid;
1398 __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid;
1399 rcu_read_unlock();
1400 return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1401 }
1402
1403 /*
1404 * Check permission between current and another task, e.g. signal checks,
1405 * fork check, ptrace check, etc.
1406 * current is the actor and tsk2 is the target
1407 * - this uses current's subjective creds
1408 */
1409 static int current_has_perm(const struct task_struct *tsk,
1410 u32 perms)
1411 {
1412 u32 sid, tsid;
1413
1414 sid = current_sid();
1415 tsid = task_sid(tsk);
1416 return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1417 }
1418
1419 #if CAP_LAST_CAP > 63
1420 #error Fix SELinux to handle capabilities > 63.
1421 #endif
1422
1423 /* Check whether a task is allowed to use a capability. */
1424 static int task_has_capability(struct task_struct *tsk,
1425 const struct cred *cred,
1426 int cap, int audit)
1427 {
1428 struct common_audit_data ad;
1429 struct av_decision avd;
1430 u16 sclass;
1431 u32 sid = cred_sid(cred);
1432 u32 av = CAP_TO_MASK(cap);
1433 int rc;
1434
1435 COMMON_AUDIT_DATA_INIT(&ad, CAP);
1436 ad.tsk = tsk;
1437 ad.u.cap = cap;
1438
1439 switch (CAP_TO_INDEX(cap)) {
1440 case 0:
1441 sclass = SECCLASS_CAPABILITY;
1442 break;
1443 case 1:
1444 sclass = SECCLASS_CAPABILITY2;
1445 break;
1446 default:
1447 printk(KERN_ERR
1448 "SELinux: out of range capability %d\n", cap);
1449 BUG();
1450 }
1451
1452 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1453 if (audit == SECURITY_CAP_AUDIT)
1454 avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1455 return rc;
1456 }
1457
1458 /* Check whether a task is allowed to use a system operation. */
1459 static int task_has_system(struct task_struct *tsk,
1460 u32 perms)
1461 {
1462 u32 sid = task_sid(tsk);
1463
1464 return avc_has_perm(sid, SECINITSID_KERNEL,
1465 SECCLASS_SYSTEM, perms, NULL);
1466 }
1467
1468 /* Check whether a task has a particular permission to an inode.
1469 The 'adp' parameter is optional and allows other audit
1470 data to be passed (e.g. the dentry). */
1471 static int inode_has_perm(const struct cred *cred,
1472 struct inode *inode,
1473 u32 perms,
1474 struct common_audit_data *adp)
1475 {
1476 struct inode_security_struct *isec;
1477 struct common_audit_data ad;
1478 u32 sid;
1479
1480 validate_creds(cred);
1481
1482 if (unlikely(IS_PRIVATE(inode)))
1483 return 0;
1484
1485 sid = cred_sid(cred);
1486 isec = inode->i_security;
1487
1488 if (!adp) {
1489 adp = &ad;
1490 COMMON_AUDIT_DATA_INIT(&ad, FS);
1491 ad.u.fs.inode = inode;
1492 }
1493
1494 return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1495 }
1496
1497 /* Same as inode_has_perm, but pass explicit audit data containing
1498 the dentry to help the auditing code to more easily generate the
1499 pathname if needed. */
1500 static inline int dentry_has_perm(const struct cred *cred,
1501 struct vfsmount *mnt,
1502 struct dentry *dentry,
1503 u32 av)
1504 {
1505 struct inode *inode = dentry->d_inode;
1506 struct common_audit_data ad;
1507
1508 COMMON_AUDIT_DATA_INIT(&ad, FS);
1509 ad.u.fs.path.mnt = mnt;
1510 ad.u.fs.path.dentry = dentry;
1511 return inode_has_perm(cred, inode, av, &ad);
1512 }
1513
1514 /* Check whether a task can use an open file descriptor to
1515 access an inode in a given way. Check access to the
1516 descriptor itself, and then use dentry_has_perm to
1517 check a particular permission to the file.
1518 Access to the descriptor is implicitly granted if it
1519 has the same SID as the process. If av is zero, then
1520 access to the file is not checked, e.g. for cases
1521 where only the descriptor is affected like seek. */
1522 static int file_has_perm(const struct cred *cred,
1523 struct file *file,
1524 u32 av)
1525 {
1526 struct file_security_struct *fsec = file->f_security;
1527 struct inode *inode = file->f_path.dentry->d_inode;
1528 struct common_audit_data ad;
1529 u32 sid = cred_sid(cred);
1530 int rc;
1531
1532 COMMON_AUDIT_DATA_INIT(&ad, FS);
1533 ad.u.fs.path = file->f_path;
1534
1535 if (sid != fsec->sid) {
1536 rc = avc_has_perm(sid, fsec->sid,
1537 SECCLASS_FD,
1538 FD__USE,
1539 &ad);
1540 if (rc)
1541 goto out;
1542 }
1543
1544 /* av is zero if only checking access to the descriptor. */
1545 rc = 0;
1546 if (av)
1547 rc = inode_has_perm(cred, inode, av, &ad);
1548
1549 out:
1550 return rc;
1551 }
1552
1553 /* Check whether a task can create a file. */
1554 static int may_create(struct inode *dir,
1555 struct dentry *dentry,
1556 u16 tclass)
1557 {
1558 const struct task_security_struct *tsec = current_security();
1559 struct inode_security_struct *dsec;
1560 struct superblock_security_struct *sbsec;
1561 u32 sid, newsid;
1562 struct common_audit_data ad;
1563 int rc;
1564
1565 dsec = dir->i_security;
1566 sbsec = dir->i_sb->s_security;
1567
1568 sid = tsec->sid;
1569 newsid = tsec->create_sid;
1570
1571 COMMON_AUDIT_DATA_INIT(&ad, FS);
1572 ad.u.fs.path.dentry = dentry;
1573
1574 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1575 DIR__ADD_NAME | DIR__SEARCH,
1576 &ad);
1577 if (rc)
1578 return rc;
1579
1580 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
1581 rc = security_transition_sid(sid, dsec->sid, tclass, &newsid);
1582 if (rc)
1583 return rc;
1584 }
1585
1586 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1587 if (rc)
1588 return rc;
1589
1590 return avc_has_perm(newsid, sbsec->sid,
1591 SECCLASS_FILESYSTEM,
1592 FILESYSTEM__ASSOCIATE, &ad);
1593 }
1594
1595 /* Check whether a task can create a key. */
1596 static int may_create_key(u32 ksid,
1597 struct task_struct *ctx)
1598 {
1599 u32 sid = task_sid(ctx);
1600
1601 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1602 }
1603
1604 #define MAY_LINK 0
1605 #define MAY_UNLINK 1
1606 #define MAY_RMDIR 2
1607
1608 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1609 static int may_link(struct inode *dir,
1610 struct dentry *dentry,
1611 int kind)
1612
1613 {
1614 struct inode_security_struct *dsec, *isec;
1615 struct common_audit_data ad;
1616 u32 sid = current_sid();
1617 u32 av;
1618 int rc;
1619
1620 dsec = dir->i_security;
1621 isec = dentry->d_inode->i_security;
1622
1623 COMMON_AUDIT_DATA_INIT(&ad, FS);
1624 ad.u.fs.path.dentry = dentry;
1625
1626 av = DIR__SEARCH;
1627 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1628 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1629 if (rc)
1630 return rc;
1631
1632 switch (kind) {
1633 case MAY_LINK:
1634 av = FILE__LINK;
1635 break;
1636 case MAY_UNLINK:
1637 av = FILE__UNLINK;
1638 break;
1639 case MAY_RMDIR:
1640 av = DIR__RMDIR;
1641 break;
1642 default:
1643 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n",
1644 __func__, kind);
1645 return 0;
1646 }
1647
1648 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1649 return rc;
1650 }
1651
1652 static inline int may_rename(struct inode *old_dir,
1653 struct dentry *old_dentry,
1654 struct inode *new_dir,
1655 struct dentry *new_dentry)
1656 {
1657 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1658 struct common_audit_data ad;
1659 u32 sid = current_sid();
1660 u32 av;
1661 int old_is_dir, new_is_dir;
1662 int rc;
1663
1664 old_dsec = old_dir->i_security;
1665 old_isec = old_dentry->d_inode->i_security;
1666 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1667 new_dsec = new_dir->i_security;
1668
1669 COMMON_AUDIT_DATA_INIT(&ad, FS);
1670
1671 ad.u.fs.path.dentry = old_dentry;
1672 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1673 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1674 if (rc)
1675 return rc;
1676 rc = avc_has_perm(sid, old_isec->sid,
1677 old_isec->sclass, FILE__RENAME, &ad);
1678 if (rc)
1679 return rc;
1680 if (old_is_dir && new_dir != old_dir) {
1681 rc = avc_has_perm(sid, old_isec->sid,
1682 old_isec->sclass, DIR__REPARENT, &ad);
1683 if (rc)
1684 return rc;
1685 }
1686
1687 ad.u.fs.path.dentry = new_dentry;
1688 av = DIR__ADD_NAME | DIR__SEARCH;
1689 if (new_dentry->d_inode)
1690 av |= DIR__REMOVE_NAME;
1691 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1692 if (rc)
1693 return rc;
1694 if (new_dentry->d_inode) {
1695 new_isec = new_dentry->d_inode->i_security;
1696 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1697 rc = avc_has_perm(sid, new_isec->sid,
1698 new_isec->sclass,
1699 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1700 if (rc)
1701 return rc;
1702 }
1703
1704 return 0;
1705 }
1706
1707 /* Check whether a task can perform a filesystem operation. */
1708 static int superblock_has_perm(const struct cred *cred,
1709 struct super_block *sb,
1710 u32 perms,
1711 struct common_audit_data *ad)
1712 {
1713 struct superblock_security_struct *sbsec;
1714 u32 sid = cred_sid(cred);
1715
1716 sbsec = sb->s_security;
1717 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1718 }
1719
1720 /* Convert a Linux mode and permission mask to an access vector. */
1721 static inline u32 file_mask_to_av(int mode, int mask)
1722 {
1723 u32 av = 0;
1724
1725 if ((mode & S_IFMT) != S_IFDIR) {
1726 if (mask & MAY_EXEC)
1727 av |= FILE__EXECUTE;
1728 if (mask & MAY_READ)
1729 av |= FILE__READ;
1730
1731 if (mask & MAY_APPEND)
1732 av |= FILE__APPEND;
1733 else if (mask & MAY_WRITE)
1734 av |= FILE__WRITE;
1735
1736 } else {
1737 if (mask & MAY_EXEC)
1738 av |= DIR__SEARCH;
1739 if (mask & MAY_WRITE)
1740 av |= DIR__WRITE;
1741 if (mask & MAY_READ)
1742 av |= DIR__READ;
1743 }
1744
1745 return av;
1746 }
1747
1748 /* Convert a Linux file to an access vector. */
1749 static inline u32 file_to_av(struct file *file)
1750 {
1751 u32 av = 0;
1752
1753 if (file->f_mode & FMODE_READ)
1754 av |= FILE__READ;
1755 if (file->f_mode & FMODE_WRITE) {
1756 if (file->f_flags & O_APPEND)
1757 av |= FILE__APPEND;
1758 else
1759 av |= FILE__WRITE;
1760 }
1761 if (!av) {
1762 /*
1763 * Special file opened with flags 3 for ioctl-only use.
1764 */
1765 av = FILE__IOCTL;
1766 }
1767
1768 return av;
1769 }
1770
1771 /*
1772 * Convert a file to an access vector and include the correct open
1773 * open permission.
1774 */
1775 static inline u32 open_file_to_av(struct file *file)
1776 {
1777 u32 av = file_to_av(file);
1778
1779 if (selinux_policycap_openperm)
1780 av |= FILE__OPEN;
1781
1782 return av;
1783 }
1784
1785 /* Hook functions begin here. */
1786
1787 static int selinux_ptrace_access_check(struct task_struct *child,
1788 unsigned int mode)
1789 {
1790 int rc;
1791
1792 rc = cap_ptrace_access_check(child, mode);
1793 if (rc)
1794 return rc;
1795
1796 if (mode == PTRACE_MODE_READ) {
1797 u32 sid = current_sid();
1798 u32 csid = task_sid(child);
1799 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
1800 }
1801
1802 return current_has_perm(child, PROCESS__PTRACE);
1803 }
1804
1805 static int selinux_ptrace_traceme(struct task_struct *parent)
1806 {
1807 int rc;
1808
1809 rc = cap_ptrace_traceme(parent);
1810 if (rc)
1811 return rc;
1812
1813 return task_has_perm(parent, current, PROCESS__PTRACE);
1814 }
1815
1816 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1817 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1818 {
1819 int error;
1820
1821 error = current_has_perm(target, PROCESS__GETCAP);
1822 if (error)
1823 return error;
1824
1825 return cap_capget(target, effective, inheritable, permitted);
1826 }
1827
1828 static int selinux_capset(struct cred *new, const struct cred *old,
1829 const kernel_cap_t *effective,
1830 const kernel_cap_t *inheritable,
1831 const kernel_cap_t *permitted)
1832 {
1833 int error;
1834
1835 error = cap_capset(new, old,
1836 effective, inheritable, permitted);
1837 if (error)
1838 return error;
1839
1840 return cred_has_perm(old, new, PROCESS__SETCAP);
1841 }
1842
1843 /*
1844 * (This comment used to live with the selinux_task_setuid hook,
1845 * which was removed).
1846 *
1847 * Since setuid only affects the current process, and since the SELinux
1848 * controls are not based on the Linux identity attributes, SELinux does not
1849 * need to control this operation. However, SELinux does control the use of
1850 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
1851 */
1852
1853 static int selinux_capable(struct task_struct *tsk, const struct cred *cred,
1854 int cap, int audit)
1855 {
1856 int rc;
1857
1858 rc = cap_capable(tsk, cred, cap, audit);
1859 if (rc)
1860 return rc;
1861
1862 return task_has_capability(tsk, cred, cap, audit);
1863 }
1864
1865 static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid)
1866 {
1867 int buflen, rc;
1868 char *buffer, *path, *end;
1869
1870 rc = -ENOMEM;
1871 buffer = (char *)__get_free_page(GFP_KERNEL);
1872 if (!buffer)
1873 goto out;
1874
1875 buflen = PAGE_SIZE;
1876 end = buffer+buflen;
1877 *--end = '\0';
1878 buflen--;
1879 path = end-1;
1880 *path = '/';
1881 while (table) {
1882 const char *name = table->procname;
1883 size_t namelen = strlen(name);
1884 buflen -= namelen + 1;
1885 if (buflen < 0)
1886 goto out_free;
1887 end -= namelen;
1888 memcpy(end, name, namelen);
1889 *--end = '/';
1890 path = end;
1891 table = table->parent;
1892 }
1893 buflen -= 4;
1894 if (buflen < 0)
1895 goto out_free;
1896 end -= 4;
1897 memcpy(end, "/sys", 4);
1898 path = end;
1899 rc = security_genfs_sid("proc", path, tclass, sid);
1900 out_free:
1901 free_page((unsigned long)buffer);
1902 out:
1903 return rc;
1904 }
1905
1906 static int selinux_sysctl(ctl_table *table, int op)
1907 {
1908 int error = 0;
1909 u32 av;
1910 u32 tsid, sid;
1911 int rc;
1912
1913 sid = current_sid();
1914
1915 rc = selinux_sysctl_get_sid(table, (op == 0001) ?
1916 SECCLASS_DIR : SECCLASS_FILE, &tsid);
1917 if (rc) {
1918 /* Default to the well-defined sysctl SID. */
1919 tsid = SECINITSID_SYSCTL;
1920 }
1921
1922 /* The op values are "defined" in sysctl.c, thereby creating
1923 * a bad coupling between this module and sysctl.c */
1924 if (op == 001) {
1925 error = avc_has_perm(sid, tsid,
1926 SECCLASS_DIR, DIR__SEARCH, NULL);
1927 } else {
1928 av = 0;
1929 if (op & 004)
1930 av |= FILE__READ;
1931 if (op & 002)
1932 av |= FILE__WRITE;
1933 if (av)
1934 error = avc_has_perm(sid, tsid,
1935 SECCLASS_FILE, av, NULL);
1936 }
1937
1938 return error;
1939 }
1940
1941 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1942 {
1943 const struct cred *cred = current_cred();
1944 int rc = 0;
1945
1946 if (!sb)
1947 return 0;
1948
1949 switch (cmds) {
1950 case Q_SYNC:
1951 case Q_QUOTAON:
1952 case Q_QUOTAOFF:
1953 case Q_SETINFO:
1954 case Q_SETQUOTA:
1955 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
1956 break;
1957 case Q_GETFMT:
1958 case Q_GETINFO:
1959 case Q_GETQUOTA:
1960 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
1961 break;
1962 default:
1963 rc = 0; /* let the kernel handle invalid cmds */
1964 break;
1965 }
1966 return rc;
1967 }
1968
1969 static int selinux_quota_on(struct dentry *dentry)
1970 {
1971 const struct cred *cred = current_cred();
1972
1973 return dentry_has_perm(cred, NULL, dentry, FILE__QUOTAON);
1974 }
1975
1976 static int selinux_syslog(int type)
1977 {
1978 int rc;
1979
1980 switch (type) {
1981 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
1982 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
1983 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1984 break;
1985 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
1986 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */
1987 /* Set level of messages printed to console */
1988 case SYSLOG_ACTION_CONSOLE_LEVEL:
1989 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1990 break;
1991 case SYSLOG_ACTION_CLOSE: /* Close log */
1992 case SYSLOG_ACTION_OPEN: /* Open log */
1993 case SYSLOG_ACTION_READ: /* Read from log */
1994 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */
1995 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */
1996 default:
1997 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1998 break;
1999 }
2000 return rc;
2001 }
2002
2003 /*
2004 * Check that a process has enough memory to allocate a new virtual
2005 * mapping. 0 means there is enough memory for the allocation to
2006 * succeed and -ENOMEM implies there is not.
2007 *
2008 * Do not audit the selinux permission check, as this is applied to all
2009 * processes that allocate mappings.
2010 */
2011 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2012 {
2013 int rc, cap_sys_admin = 0;
2014
2015 rc = selinux_capable(current, current_cred(), CAP_SYS_ADMIN,
2016 SECURITY_CAP_NOAUDIT);
2017 if (rc == 0)
2018 cap_sys_admin = 1;
2019
2020 return __vm_enough_memory(mm, pages, cap_sys_admin);
2021 }
2022
2023 /* binprm security operations */
2024
2025 static int selinux_bprm_set_creds(struct linux_binprm *bprm)
2026 {
2027 const struct task_security_struct *old_tsec;
2028 struct task_security_struct *new_tsec;
2029 struct inode_security_struct *isec;
2030 struct common_audit_data ad;
2031 struct inode *inode = bprm->file->f_path.dentry->d_inode;
2032 int rc;
2033
2034 rc = cap_bprm_set_creds(bprm);
2035 if (rc)
2036 return rc;
2037
2038 /* SELinux context only depends on initial program or script and not
2039 * the script interpreter */
2040 if (bprm->cred_prepared)
2041 return 0;
2042
2043 old_tsec = current_security();
2044 new_tsec = bprm->cred->security;
2045 isec = inode->i_security;
2046
2047 /* Default to the current task SID. */
2048 new_tsec->sid = old_tsec->sid;
2049 new_tsec->osid = old_tsec->sid;
2050
2051 /* Reset fs, key, and sock SIDs on execve. */
2052 new_tsec->create_sid = 0;
2053 new_tsec->keycreate_sid = 0;
2054 new_tsec->sockcreate_sid = 0;
2055
2056 if (old_tsec->exec_sid) {
2057 new_tsec->sid = old_tsec->exec_sid;
2058 /* Reset exec SID on execve. */
2059 new_tsec->exec_sid = 0;
2060 } else {
2061 /* Check for a default transition on this program. */
2062 rc = security_transition_sid(old_tsec->sid, isec->sid,
2063 SECCLASS_PROCESS, &new_tsec->sid);
2064 if (rc)
2065 return rc;
2066 }
2067
2068 COMMON_AUDIT_DATA_INIT(&ad, FS);
2069 ad.u.fs.path = bprm->file->f_path;
2070
2071 if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
2072 new_tsec->sid = old_tsec->sid;
2073
2074 if (new_tsec->sid == old_tsec->sid) {
2075 rc = avc_has_perm(old_tsec->sid, isec->sid,
2076 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2077 if (rc)
2078 return rc;
2079 } else {
2080 /* Check permissions for the transition. */
2081 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2082 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2083 if (rc)
2084 return rc;
2085
2086 rc = avc_has_perm(new_tsec->sid, isec->sid,
2087 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2088 if (rc)
2089 return rc;
2090
2091 /* Check for shared state */
2092 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2093 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2094 SECCLASS_PROCESS, PROCESS__SHARE,
2095 NULL);
2096 if (rc)
2097 return -EPERM;
2098 }
2099
2100 /* Make sure that anyone attempting to ptrace over a task that
2101 * changes its SID has the appropriate permit */
2102 if (bprm->unsafe &
2103 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2104 struct task_struct *tracer;
2105 struct task_security_struct *sec;
2106 u32 ptsid = 0;
2107
2108 rcu_read_lock();
2109 tracer = tracehook_tracer_task(current);
2110 if (likely(tracer != NULL)) {
2111 sec = __task_cred(tracer)->security;
2112 ptsid = sec->sid;
2113 }
2114 rcu_read_unlock();
2115
2116 if (ptsid != 0) {
2117 rc = avc_has_perm(ptsid, new_tsec->sid,
2118 SECCLASS_PROCESS,
2119 PROCESS__PTRACE, NULL);
2120 if (rc)
2121 return -EPERM;
2122 }
2123 }
2124
2125 /* Clear any possibly unsafe personality bits on exec: */
2126 bprm->per_clear |= PER_CLEAR_ON_SETID;
2127 }
2128
2129 return 0;
2130 }
2131
2132 static int selinux_bprm_secureexec(struct linux_binprm *bprm)
2133 {
2134 const struct task_security_struct *tsec = current_security();
2135 u32 sid, osid;
2136 int atsecure = 0;
2137
2138 sid = tsec->sid;
2139 osid = tsec->osid;
2140
2141 if (osid != sid) {
2142 /* Enable secure mode for SIDs transitions unless
2143 the noatsecure permission is granted between
2144 the two SIDs, i.e. ahp returns 0. */
2145 atsecure = avc_has_perm(osid, sid,
2146 SECCLASS_PROCESS,
2147 PROCESS__NOATSECURE, NULL);
2148 }
2149
2150 return (atsecure || cap_bprm_secureexec(bprm));
2151 }
2152
2153 extern struct vfsmount *selinuxfs_mount;
2154 extern struct dentry *selinux_null;
2155
2156 /* Derived from fs/exec.c:flush_old_files. */
2157 static inline void flush_unauthorized_files(const struct cred *cred,
2158 struct files_struct *files)
2159 {
2160 struct common_audit_data ad;
2161 struct file *file, *devnull = NULL;
2162 struct tty_struct *tty;
2163 struct fdtable *fdt;
2164 long j = -1;
2165 int drop_tty = 0;
2166
2167 tty = get_current_tty();
2168 if (tty) {
2169 spin_lock(&tty_files_lock);
2170 if (!list_empty(&tty->tty_files)) {
2171 struct tty_file_private *file_priv;
2172 struct inode *inode;
2173
2174 /* Revalidate access to controlling tty.
2175 Use inode_has_perm on the tty inode directly rather
2176 than using file_has_perm, as this particular open
2177 file may belong to another process and we are only
2178 interested in the inode-based check here. */
2179 file_priv = list_first_entry(&tty->tty_files,
2180 struct tty_file_private, list);
2181 file = file_priv->file;
2182 inode = file->f_path.dentry->d_inode;
2183 if (inode_has_perm(cred, inode,
2184 FILE__READ | FILE__WRITE, NULL)) {
2185 drop_tty = 1;
2186 }
2187 }
2188 spin_unlock(&tty_files_lock);
2189 tty_kref_put(tty);
2190 }
2191 /* Reset controlling tty. */
2192 if (drop_tty)
2193 no_tty();
2194
2195 /* Revalidate access to inherited open files. */
2196
2197 COMMON_AUDIT_DATA_INIT(&ad, FS);
2198
2199 spin_lock(&files->file_lock);
2200 for (;;) {
2201 unsigned long set, i;
2202 int fd;
2203
2204 j++;
2205 i = j * __NFDBITS;
2206 fdt = files_fdtable(files);
2207 if (i >= fdt->max_fds)
2208 break;
2209 set = fdt->open_fds->fds_bits[j];
2210 if (!set)
2211 continue;
2212 spin_unlock(&files->file_lock);
2213 for ( ; set ; i++, set >>= 1) {
2214 if (set & 1) {
2215 file = fget(i);
2216 if (!file)
2217 continue;
2218 if (file_has_perm(cred,
2219 file,
2220 file_to_av(file))) {
2221 sys_close(i);
2222 fd = get_unused_fd();
2223 if (fd != i) {
2224 if (fd >= 0)
2225 put_unused_fd(fd);
2226 fput(file);
2227 continue;
2228 }
2229 if (devnull) {
2230 get_file(devnull);
2231 } else {
2232 devnull = dentry_open(
2233 dget(selinux_null),
2234 mntget(selinuxfs_mount),
2235 O_RDWR, cred);
2236 if (IS_ERR(devnull)) {
2237 devnull = NULL;
2238 put_unused_fd(fd);
2239 fput(file);
2240 continue;
2241 }
2242 }
2243 fd_install(fd, devnull);
2244 }
2245 fput(file);
2246 }
2247 }
2248 spin_lock(&files->file_lock);
2249
2250 }
2251 spin_unlock(&files->file_lock);
2252 }
2253
2254 /*
2255 * Prepare a process for imminent new credential changes due to exec
2256 */
2257 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2258 {
2259 struct task_security_struct *new_tsec;
2260 struct rlimit *rlim, *initrlim;
2261 int rc, i;
2262
2263 new_tsec = bprm->cred->security;
2264 if (new_tsec->sid == new_tsec->osid)
2265 return;
2266
2267 /* Close files for which the new task SID is not authorized. */
2268 flush_unauthorized_files(bprm->cred, current->files);
2269
2270 /* Always clear parent death signal on SID transitions. */
2271 current->pdeath_signal = 0;
2272
2273 /* Check whether the new SID can inherit resource limits from the old
2274 * SID. If not, reset all soft limits to the lower of the current
2275 * task's hard limit and the init task's soft limit.
2276 *
2277 * Note that the setting of hard limits (even to lower them) can be
2278 * controlled by the setrlimit check. The inclusion of the init task's
2279 * soft limit into the computation is to avoid resetting soft limits
2280 * higher than the default soft limit for cases where the default is
2281 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2282 */
2283 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2284 PROCESS__RLIMITINH, NULL);
2285 if (rc) {
2286 /* protect against do_prlimit() */
2287 task_lock(current);
2288 for (i = 0; i < RLIM_NLIMITS; i++) {
2289 rlim = current->signal->rlim + i;
2290 initrlim = init_task.signal->rlim + i;
2291 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2292 }
2293 task_unlock(current);
2294 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2295 }
2296 }
2297
2298 /*
2299 * Clean up the process immediately after the installation of new credentials
2300 * due to exec
2301 */
2302 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2303 {
2304 const struct task_security_struct *tsec = current_security();
2305 struct itimerval itimer;
2306 u32 osid, sid;
2307 int rc, i;
2308
2309 osid = tsec->osid;
2310 sid = tsec->sid;
2311
2312 if (sid == osid)
2313 return;
2314
2315 /* Check whether the new SID can inherit signal state from the old SID.
2316 * If not, clear itimers to avoid subsequent signal generation and
2317 * flush and unblock signals.
2318 *
2319 * This must occur _after_ the task SID has been updated so that any
2320 * kill done after the flush will be checked against the new SID.
2321 */
2322 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2323 if (rc) {
2324 memset(&itimer, 0, sizeof itimer);
2325 for (i = 0; i < 3; i++)
2326 do_setitimer(i, &itimer, NULL);
2327 spin_lock_irq(&current->sighand->siglock);
2328 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
2329 __flush_signals(current);
2330 flush_signal_handlers(current, 1);
2331 sigemptyset(&current->blocked);
2332 }
2333 spin_unlock_irq(&current->sighand->siglock);
2334 }
2335
2336 /* Wake up the parent if it is waiting so that it can recheck
2337 * wait permission to the new task SID. */
2338 read_lock(&tasklist_lock);
2339 __wake_up_parent(current, current->real_parent);
2340 read_unlock(&tasklist_lock);
2341 }
2342
2343 /* superblock security operations */
2344
2345 static int selinux_sb_alloc_security(struct super_block *sb)
2346 {
2347 return superblock_alloc_security(sb);
2348 }
2349
2350 static void selinux_sb_free_security(struct super_block *sb)
2351 {
2352 superblock_free_security(sb);
2353 }
2354
2355 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2356 {
2357 if (plen > olen)
2358 return 0;
2359
2360 return !memcmp(prefix, option, plen);
2361 }
2362
2363 static inline int selinux_option(char *option, int len)
2364 {
2365 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2366 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2367 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2368 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2369 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
2370 }
2371
2372 static inline void take_option(char **to, char *from, int *first, int len)
2373 {
2374 if (!*first) {
2375 **to = ',';
2376 *to += 1;
2377 } else
2378 *first = 0;
2379 memcpy(*to, from, len);
2380 *to += len;
2381 }
2382
2383 static inline void take_selinux_option(char **to, char *from, int *first,
2384 int len)
2385 {
2386 int current_size = 0;
2387
2388 if (!*first) {
2389 **to = '|';
2390 *to += 1;
2391 } else
2392 *first = 0;
2393
2394 while (current_size < len) {
2395 if (*from != '"') {
2396 **to = *from;
2397 *to += 1;
2398 }
2399 from += 1;
2400 current_size += 1;
2401 }
2402 }
2403
2404 static int selinux_sb_copy_data(char *orig, char *copy)
2405 {
2406 int fnosec, fsec, rc = 0;
2407 char *in_save, *in_curr, *in_end;
2408 char *sec_curr, *nosec_save, *nosec;
2409 int open_quote = 0;
2410
2411 in_curr = orig;
2412 sec_curr = copy;
2413
2414 nosec = (char *)get_zeroed_page(GFP_KERNEL);
2415 if (!nosec) {
2416 rc = -ENOMEM;
2417 goto out;
2418 }
2419
2420 nosec_save = nosec;
2421 fnosec = fsec = 1;
2422 in_save = in_end = orig;
2423
2424 do {
2425 if (*in_end == '"')
2426 open_quote = !open_quote;
2427 if ((*in_end == ',' && open_quote == 0) ||
2428 *in_end == '\0') {
2429 int len = in_end - in_curr;
2430
2431 if (selinux_option(in_curr, len))
2432 take_selinux_option(&sec_curr, in_curr, &fsec, len);
2433 else
2434 take_option(&nosec, in_curr, &fnosec, len);
2435
2436 in_curr = in_end + 1;
2437 }
2438 } while (*in_end++);
2439
2440 strcpy(in_save, nosec_save);
2441 free_page((unsigned long)nosec_save);
2442 out:
2443 return rc;
2444 }
2445
2446 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
2447 {
2448 const struct cred *cred = current_cred();
2449 struct common_audit_data ad;
2450 int rc;
2451
2452 rc = superblock_doinit(sb, data);
2453 if (rc)
2454 return rc;
2455
2456 /* Allow all mounts performed by the kernel */
2457 if (flags & MS_KERNMOUNT)
2458 return 0;
2459
2460 COMMON_AUDIT_DATA_INIT(&ad, FS);
2461 ad.u.fs.path.dentry = sb->s_root;
2462 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2463 }
2464
2465 static int selinux_sb_statfs(struct dentry *dentry)
2466 {
2467 const struct cred *cred = current_cred();
2468 struct common_audit_data ad;
2469
2470 COMMON_AUDIT_DATA_INIT(&ad, FS);
2471 ad.u.fs.path.dentry = dentry->d_sb->s_root;
2472 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2473 }
2474
2475 static int selinux_mount(char *dev_name,
2476 struct path *path,
2477 char *type,
2478 unsigned long flags,
2479 void *data)
2480 {
2481 const struct cred *cred = current_cred();
2482
2483 if (flags & MS_REMOUNT)
2484 return superblock_has_perm(cred, path->mnt->mnt_sb,
2485 FILESYSTEM__REMOUNT, NULL);
2486 else
2487 return dentry_has_perm(cred, path->mnt, path->dentry,
2488 FILE__MOUNTON);
2489 }
2490
2491 static int selinux_umount(struct vfsmount *mnt, int flags)
2492 {
2493 const struct cred *cred = current_cred();
2494
2495 return superblock_has_perm(cred, mnt->mnt_sb,
2496 FILESYSTEM__UNMOUNT, NULL);
2497 }
2498
2499 /* inode security operations */
2500
2501 static int selinux_inode_alloc_security(struct inode *inode)
2502 {
2503 return inode_alloc_security(inode);
2504 }
2505
2506 static void selinux_inode_free_security(struct inode *inode)
2507 {
2508 inode_free_security(inode);
2509 }
2510
2511 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2512 char **name, void **value,
2513 size_t *len)
2514 {
2515 const struct task_security_struct *tsec = current_security();
2516 struct inode_security_struct *dsec;
2517 struct superblock_security_struct *sbsec;
2518 u32 sid, newsid, clen;
2519 int rc;
2520 char *namep = NULL, *context;
2521
2522 dsec = dir->i_security;
2523 sbsec = dir->i_sb->s_security;
2524
2525 sid = tsec->sid;
2526 newsid = tsec->create_sid;
2527
2528 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
2529 rc = security_transition_sid(sid, dsec->sid,
2530 inode_mode_to_security_class(inode->i_mode),
2531 &newsid);
2532 if (rc) {
2533 printk(KERN_WARNING "%s: "
2534 "security_transition_sid failed, rc=%d (dev=%s "
2535 "ino=%ld)\n",
2536 __func__,
2537 -rc, inode->i_sb->s_id, inode->i_ino);
2538 return rc;
2539 }
2540 }
2541
2542 /* Possibly defer initialization to selinux_complete_init. */
2543 if (sbsec->flags & SE_SBINITIALIZED) {
2544 struct inode_security_struct *isec = inode->i_security;
2545 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2546 isec->sid = newsid;
2547 isec->initialized = 1;
2548 }
2549
2550 if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
2551 return -EOPNOTSUPP;
2552
2553 if (name) {
2554 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
2555 if (!namep)
2556 return -ENOMEM;
2557 *name = namep;
2558 }
2559
2560 if (value && len) {
2561 rc = security_sid_to_context_force(newsid, &context, &clen);
2562 if (rc) {
2563 kfree(namep);
2564 return rc;
2565 }
2566 *value = context;
2567 *len = clen;
2568 }
2569
2570 return 0;
2571 }
2572
2573 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2574 {
2575 return may_create(dir, dentry, SECCLASS_FILE);
2576 }
2577
2578 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2579 {
2580 return may_link(dir, old_dentry, MAY_LINK);
2581 }
2582
2583 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2584 {
2585 return may_link(dir, dentry, MAY_UNLINK);
2586 }
2587
2588 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2589 {
2590 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2591 }
2592
2593 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2594 {
2595 return may_create(dir, dentry, SECCLASS_DIR);
2596 }
2597
2598 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2599 {
2600 return may_link(dir, dentry, MAY_RMDIR);
2601 }
2602
2603 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2604 {
2605 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2606 }
2607
2608 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2609 struct inode *new_inode, struct dentry *new_dentry)
2610 {
2611 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2612 }
2613
2614 static int selinux_inode_readlink(struct dentry *dentry)
2615 {
2616 const struct cred *cred = current_cred();
2617
2618 return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2619 }
2620
2621 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2622 {
2623 const struct cred *cred = current_cred();
2624
2625 return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2626 }
2627
2628 static int selinux_inode_permission(struct inode *inode, int mask)
2629 {
2630 const struct cred *cred = current_cred();
2631 struct common_audit_data ad;
2632 u32 perms;
2633 bool from_access;
2634
2635 from_access = mask & MAY_ACCESS;
2636 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
2637
2638 /* No permission to check. Existence test. */
2639 if (!mask)
2640 return 0;
2641
2642 COMMON_AUDIT_DATA_INIT(&ad, FS);
2643 ad.u.fs.inode = inode;
2644
2645 if (from_access)
2646 ad.selinux_audit_data.auditdeny |= FILE__AUDIT_ACCESS;
2647
2648 perms = file_mask_to_av(inode->i_mode, mask);
2649
2650 return inode_has_perm(cred, inode, perms, &ad);
2651 }
2652
2653 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2654 {
2655 const struct cred *cred = current_cred();
2656 unsigned int ia_valid = iattr->ia_valid;
2657
2658 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2659 if (ia_valid & ATTR_FORCE) {
2660 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2661 ATTR_FORCE);
2662 if (!ia_valid)
2663 return 0;
2664 }
2665
2666 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2667 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2668 return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2669
2670 return dentry_has_perm(cred, NULL, dentry, FILE__WRITE);
2671 }
2672
2673 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2674 {
2675 const struct cred *cred = current_cred();
2676
2677 return dentry_has_perm(cred, mnt, dentry, FILE__GETATTR);
2678 }
2679
2680 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2681 {
2682 const struct cred *cred = current_cred();
2683
2684 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2685 sizeof XATTR_SECURITY_PREFIX - 1)) {
2686 if (!strcmp(name, XATTR_NAME_CAPS)) {
2687 if (!capable(CAP_SETFCAP))
2688 return -EPERM;
2689 } else if (!capable(CAP_SYS_ADMIN)) {
2690 /* A different attribute in the security namespace.
2691 Restrict to administrator. */
2692 return -EPERM;
2693 }
2694 }
2695
2696 /* Not an attribute we recognize, so just check the
2697 ordinary setattr permission. */
2698 return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2699 }
2700
2701 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2702 const void *value, size_t size, int flags)
2703 {
2704 struct inode *inode = dentry->d_inode;
2705 struct inode_security_struct *isec = inode->i_security;
2706 struct superblock_security_struct *sbsec;
2707 struct common_audit_data ad;
2708 u32 newsid, sid = current_sid();
2709 int rc = 0;
2710
2711 if (strcmp(name, XATTR_NAME_SELINUX))
2712 return selinux_inode_setotherxattr(dentry, name);
2713
2714 sbsec = inode->i_sb->s_security;
2715 if (!(sbsec->flags & SE_SBLABELSUPP))
2716 return -EOPNOTSUPP;
2717
2718 if (!is_owner_or_cap(inode))
2719 return -EPERM;
2720
2721 COMMON_AUDIT_DATA_INIT(&ad, FS);
2722 ad.u.fs.path.dentry = dentry;
2723
2724 rc = avc_has_perm(sid, isec->sid, isec->sclass,
2725 FILE__RELABELFROM, &ad);
2726 if (rc)
2727 return rc;
2728
2729 rc = security_context_to_sid(value, size, &newsid);
2730 if (rc == -EINVAL) {
2731 if (!capable(CAP_MAC_ADMIN))
2732 return rc;
2733 rc = security_context_to_sid_force(value, size, &newsid);
2734 }
2735 if (rc)
2736 return rc;
2737
2738 rc = avc_has_perm(sid, newsid, isec->sclass,
2739 FILE__RELABELTO, &ad);
2740 if (rc)
2741 return rc;
2742
2743 rc = security_validate_transition(isec->sid, newsid, sid,
2744 isec->sclass);
2745 if (rc)
2746 return rc;
2747
2748 return avc_has_perm(newsid,
2749 sbsec->sid,
2750 SECCLASS_FILESYSTEM,
2751 FILESYSTEM__ASSOCIATE,
2752 &ad);
2753 }
2754
2755 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2756 const void *value, size_t size,
2757 int flags)
2758 {
2759 struct inode *inode = dentry->d_inode;
2760 struct inode_security_struct *isec = inode->i_security;
2761 u32 newsid;
2762 int rc;
2763
2764 if (strcmp(name, XATTR_NAME_SELINUX)) {
2765 /* Not an attribute we recognize, so nothing to do. */
2766 return;
2767 }
2768
2769 rc = security_context_to_sid_force(value, size, &newsid);
2770 if (rc) {
2771 printk(KERN_ERR "SELinux: unable to map context to SID"
2772 "for (%s, %lu), rc=%d\n",
2773 inode->i_sb->s_id, inode->i_ino, -rc);
2774 return;
2775 }
2776
2777 isec->sid = newsid;
2778 return;
2779 }
2780
2781 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
2782 {
2783 const struct cred *cred = current_cred();
2784
2785 return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2786 }
2787
2788 static int selinux_inode_listxattr(struct dentry *dentry)
2789 {
2790 const struct cred *cred = current_cred();
2791
2792 return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2793 }
2794
2795 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
2796 {
2797 if (strcmp(name, XATTR_NAME_SELINUX))
2798 return selinux_inode_setotherxattr(dentry, name);
2799
2800 /* No one is allowed to remove a SELinux security label.
2801 You can change the label, but all data must be labeled. */
2802 return -EACCES;
2803 }
2804
2805 /*
2806 * Copy the inode security context value to the user.
2807 *
2808 * Permission check is handled by selinux_inode_getxattr hook.
2809 */
2810 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
2811 {
2812 u32 size;
2813 int error;
2814 char *context = NULL;
2815 struct inode_security_struct *isec = inode->i_security;
2816
2817 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2818 return -EOPNOTSUPP;
2819
2820 /*
2821 * If the caller has CAP_MAC_ADMIN, then get the raw context
2822 * value even if it is not defined by current policy; otherwise,
2823 * use the in-core value under current policy.
2824 * Use the non-auditing forms of the permission checks since
2825 * getxattr may be called by unprivileged processes commonly
2826 * and lack of permission just means that we fall back to the
2827 * in-core context value, not a denial.
2828 */
2829 error = selinux_capable(current, current_cred(), CAP_MAC_ADMIN,
2830 SECURITY_CAP_NOAUDIT);
2831 if (!error)
2832 error = security_sid_to_context_force(isec->sid, &context,
2833 &size);
2834 else
2835 error = security_sid_to_context(isec->sid, &context, &size);
2836 if (error)
2837 return error;
2838 error = size;
2839 if (alloc) {
2840 *buffer = context;
2841 goto out_nofree;
2842 }
2843 kfree(context);
2844 out_nofree:
2845 return error;
2846 }
2847
2848 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2849 const void *value, size_t size, int flags)
2850 {
2851 struct inode_security_struct *isec = inode->i_security;
2852 u32 newsid;
2853 int rc;
2854
2855 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2856 return -EOPNOTSUPP;
2857
2858 if (!value || !size)
2859 return -EACCES;
2860
2861 rc = security_context_to_sid((void *)value, size, &newsid);
2862 if (rc)
2863 return rc;
2864
2865 isec->sid = newsid;
2866 isec->initialized = 1;
2867 return 0;
2868 }
2869
2870 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2871 {
2872 const int len = sizeof(XATTR_NAME_SELINUX);
2873 if (buffer && len <= buffer_size)
2874 memcpy(buffer, XATTR_NAME_SELINUX, len);
2875 return len;
2876 }
2877
2878 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2879 {
2880 struct inode_security_struct *isec = inode->i_security;
2881 *secid = isec->sid;
2882 }
2883
2884 /* file security operations */
2885
2886 static int selinux_revalidate_file_permission(struct file *file, int mask)
2887 {
2888 const struct cred *cred = current_cred();
2889 struct inode *inode = file->f_path.dentry->d_inode;
2890
2891 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2892 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2893 mask |= MAY_APPEND;
2894
2895 return file_has_perm(cred, file,
2896 file_mask_to_av(inode->i_mode, mask));
2897 }
2898
2899 static int selinux_file_permission(struct file *file, int mask)
2900 {
2901 struct inode *inode = file->f_path.dentry->d_inode;
2902 struct file_security_struct *fsec = file->f_security;
2903 struct inode_security_struct *isec = inode->i_security;
2904 u32 sid = current_sid();
2905
2906 if (!mask)
2907 /* No permission to check. Existence test. */
2908 return 0;
2909
2910 if (sid == fsec->sid && fsec->isid == isec->sid &&
2911 fsec->pseqno == avc_policy_seqno())
2912 /* No change since dentry_open check. */
2913 return 0;
2914
2915 return selinux_revalidate_file_permission(file, mask);
2916 }
2917
2918 static int selinux_file_alloc_security(struct file *file)
2919 {
2920 return file_alloc_security(file);
2921 }
2922
2923 static void selinux_file_free_security(struct file *file)
2924 {
2925 file_free_security(file);
2926 }
2927
2928 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2929 unsigned long arg)
2930 {
2931 const struct cred *cred = current_cred();
2932 u32 av = 0;
2933
2934 if (_IOC_DIR(cmd) & _IOC_WRITE)
2935 av |= FILE__WRITE;
2936 if (_IOC_DIR(cmd) & _IOC_READ)
2937 av |= FILE__READ;
2938 if (!av)
2939 av = FILE__IOCTL;
2940
2941 return file_has_perm(cred, file, av);
2942 }
2943
2944 static int default_noexec;
2945
2946 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2947 {
2948 const struct cred *cred = current_cred();
2949 int rc = 0;
2950
2951 if (default_noexec &&
2952 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2953 /*
2954 * We are making executable an anonymous mapping or a
2955 * private file mapping that will also be writable.
2956 * This has an additional check.
2957 */
2958 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
2959 if (rc)
2960 goto error;
2961 }
2962
2963 if (file) {
2964 /* read access is always possible with a mapping */
2965 u32 av = FILE__READ;
2966
2967 /* write access only matters if the mapping is shared */
2968 if (shared && (prot & PROT_WRITE))
2969 av |= FILE__WRITE;
2970
2971 if (prot & PROT_EXEC)
2972 av |= FILE__EXECUTE;
2973
2974 return file_has_perm(cred, file, av);
2975 }
2976
2977 error:
2978 return rc;
2979 }
2980
2981 static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2982 unsigned long prot, unsigned long flags,
2983 unsigned long addr, unsigned long addr_only)
2984 {
2985 int rc = 0;
2986 u32 sid = current_sid();
2987
2988 /*
2989 * notice that we are intentionally putting the SELinux check before
2990 * the secondary cap_file_mmap check. This is such a likely attempt
2991 * at bad behaviour/exploit that we always want to get the AVC, even
2992 * if DAC would have also denied the operation.
2993 */
2994 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
2995 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
2996 MEMPROTECT__MMAP_ZERO, NULL);
2997 if (rc)
2998 return rc;
2999 }
3000
3001 /* do DAC check on address space usage */
3002 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
3003 if (rc || addr_only)
3004 return rc;
3005
3006 if (selinux_checkreqprot)
3007 prot = reqprot;
3008
3009 return file_map_prot_check(file, prot,
3010 (flags & MAP_TYPE) == MAP_SHARED);
3011 }
3012
3013 static int selinux_file_mprotect(struct vm_area_struct *vma,
3014 unsigned long reqprot,
3015 unsigned long prot)
3016 {
3017 const struct cred *cred = current_cred();
3018
3019 if (selinux_checkreqprot)
3020 prot = reqprot;
3021
3022 if (default_noexec &&
3023 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3024 int rc = 0;
3025 if (vma->vm_start >= vma->vm_mm->start_brk &&
3026 vma->vm_end <= vma->vm_mm->brk) {
3027 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3028 } else if (!vma->vm_file &&
3029 vma->vm_start <= vma->vm_mm->start_stack &&
3030 vma->vm_end >= vma->vm_mm->start_stack) {
3031 rc = current_has_perm(current, PROCESS__EXECSTACK);
3032 } else if (vma->vm_file && vma->anon_vma) {
3033 /*
3034 * We are making executable a file mapping that has
3035 * had some COW done. Since pages might have been
3036 * written, check ability to execute the possibly
3037 * modified content. This typically should only
3038 * occur for text relocations.
3039 */
3040 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3041 }
3042 if (rc)
3043 return rc;
3044 }
3045
3046 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3047 }
3048
3049 static int selinux_file_lock(struct file *file, unsigned int cmd)
3050 {
3051 const struct cred *cred = current_cred();
3052
3053 return file_has_perm(cred, file, FILE__LOCK);
3054 }
3055
3056 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3057 unsigned long arg)
3058 {
3059 const struct cred *cred = current_cred();
3060 int err = 0;
3061
3062 switch (cmd) {
3063 case F_SETFL:
3064 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3065 err = -EINVAL;
3066 break;
3067 }
3068
3069 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3070 err = file_has_perm(cred, file, FILE__WRITE);
3071 break;
3072 }
3073 /* fall through */
3074 case F_SETOWN:
3075 case F_SETSIG:
3076 case F_GETFL:
3077 case F_GETOWN:
3078 case F_GETSIG:
3079 /* Just check FD__USE permission */
3080 err = file_has_perm(cred, file, 0);
3081 break;
3082 case F_GETLK:
3083 case F_SETLK:
3084 case F_SETLKW:
3085 #if BITS_PER_LONG == 32
3086 case F_GETLK64:
3087 case F_SETLK64:
3088 case F_SETLKW64:
3089 #endif
3090 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3091 err = -EINVAL;
3092 break;
3093 }
3094 err = file_has_perm(cred, file, FILE__LOCK);
3095 break;
3096 }
3097
3098 return err;
3099 }
3100
3101 static int selinux_file_set_fowner(struct file *file)
3102 {
3103 struct file_security_struct *fsec;
3104
3105 fsec = file->f_security;
3106 fsec->fown_sid = current_sid();
3107
3108 return 0;
3109 }
3110
3111 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3112 struct fown_struct *fown, int signum)
3113 {
3114 struct file *file;
3115 u32 sid = task_sid(tsk);
3116 u32 perm;
3117 struct file_security_struct *fsec;
3118
3119 /* struct fown_struct is never outside the context of a struct file */
3120 file = container_of(fown, struct file, f_owner);
3121
3122 fsec = file->f_security;
3123
3124 if (!signum)
3125 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3126 else
3127 perm = signal_to_av(signum);
3128
3129 return avc_has_perm(fsec->fown_sid, sid,
3130 SECCLASS_PROCESS, perm, NULL);
3131 }
3132
3133 static int selinux_file_receive(struct file *file)
3134 {
3135 const struct cred *cred = current_cred();
3136
3137 return file_has_perm(cred, file, file_to_av(file));
3138 }
3139
3140 static int selinux_dentry_open(struct file *file, const struct cred *cred)
3141 {
3142 struct file_security_struct *fsec;
3143 struct inode *inode;
3144 struct inode_security_struct *isec;
3145
3146 inode = file->f_path.dentry->d_inode;
3147 fsec = file->f_security;
3148 isec = inode->i_security;
3149 /*
3150 * Save inode label and policy sequence number
3151 * at open-time so that selinux_file_permission
3152 * can determine whether revalidation is necessary.
3153 * Task label is already saved in the file security
3154 * struct as its SID.
3155 */
3156 fsec->isid = isec->sid;
3157 fsec->pseqno = avc_policy_seqno();
3158 /*
3159 * Since the inode label or policy seqno may have changed
3160 * between the selinux_inode_permission check and the saving
3161 * of state above, recheck that access is still permitted.
3162 * Otherwise, access might never be revalidated against the
3163 * new inode label or new policy.
3164 * This check is not redundant - do not remove.
3165 */
3166 return inode_has_perm(cred, inode, open_file_to_av(file), NULL);
3167 }
3168
3169 /* task security operations */
3170
3171 static int selinux_task_create(unsigned long clone_flags)
3172 {
3173 return current_has_perm(current, PROCESS__FORK);
3174 }
3175
3176 /*
3177 * allocate the SELinux part of blank credentials
3178 */
3179 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3180 {
3181 struct task_security_struct *tsec;
3182
3183 tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3184 if (!tsec)
3185 return -ENOMEM;
3186
3187 cred->security = tsec;
3188 return 0;
3189 }
3190
3191 /*
3192 * detach and free the LSM part of a set of credentials
3193 */
3194 static void selinux_cred_free(struct cred *cred)
3195 {
3196 struct task_security_struct *tsec = cred->security;
3197
3198 BUG_ON((unsigned long) cred->security < PAGE_SIZE);
3199 cred->security = (void *) 0x7UL;
3200 kfree(tsec);
3201 }
3202
3203 /*
3204 * prepare a new set of credentials for modification
3205 */
3206 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3207 gfp_t gfp)
3208 {
3209 const struct task_security_struct *old_tsec;
3210 struct task_security_struct *tsec;
3211
3212 old_tsec = old->security;
3213
3214 tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3215 if (!tsec)
3216 return -ENOMEM;
3217
3218 new->security = tsec;
3219 return 0;
3220 }
3221
3222 /*
3223 * transfer the SELinux data to a blank set of creds
3224 */
3225 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3226 {
3227 const struct task_security_struct *old_tsec = old->security;
3228 struct task_security_struct *tsec = new->security;
3229
3230 *tsec = *old_tsec;
3231 }
3232
3233 /*
3234 * set the security data for a kernel service
3235 * - all the creation contexts are set to unlabelled
3236 */
3237 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3238 {
3239 struct task_security_struct *tsec = new->security;
3240 u32 sid = current_sid();
3241 int ret;
3242
3243 ret = avc_has_perm(sid, secid,
3244 SECCLASS_KERNEL_SERVICE,
3245 KERNEL_SERVICE__USE_AS_OVERRIDE,
3246 NULL);
3247 if (ret == 0) {
3248 tsec->sid = secid;
3249 tsec->create_sid = 0;
3250 tsec->keycreate_sid = 0;
3251 tsec->sockcreate_sid = 0;
3252 }
3253 return ret;
3254 }
3255
3256 /*
3257 * set the file creation context in a security record to the same as the
3258 * objective context of the specified inode
3259 */
3260 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3261 {
3262 struct inode_security_struct *isec = inode->i_security;
3263 struct task_security_struct *tsec = new->security;
3264 u32 sid = current_sid();
3265 int ret;
3266
3267 ret = avc_has_perm(sid, isec->sid,
3268 SECCLASS_KERNEL_SERVICE,
3269 KERNEL_SERVICE__CREATE_FILES_AS,
3270 NULL);
3271
3272 if (ret == 0)
3273 tsec->create_sid = isec->sid;
3274 return ret;
3275 }
3276
3277 static int selinux_kernel_module_request(char *kmod_name)
3278 {
3279 u32 sid;
3280 struct common_audit_data ad;
3281
3282 sid = task_sid(current);
3283
3284 COMMON_AUDIT_DATA_INIT(&ad, KMOD);
3285 ad.u.kmod_name = kmod_name;
3286
3287 return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
3288 SYSTEM__MODULE_REQUEST, &ad);
3289 }
3290
3291 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3292 {
3293 return current_has_perm(p, PROCESS__SETPGID);
3294 }
3295
3296 static int selinux_task_getpgid(struct task_struct *p)
3297 {
3298 return current_has_perm(p, PROCESS__GETPGID);
3299 }
3300
3301 static int selinux_task_getsid(struct task_struct *p)
3302 {
3303 return current_has_perm(p, PROCESS__GETSESSION);
3304 }
3305
3306 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3307 {
3308 *secid = task_sid(p);
3309 }
3310
3311 static int selinux_task_setnice(struct task_struct *p, int nice)
3312 {
3313 int rc;
3314
3315 rc = cap_task_setnice(p, nice);
3316 if (rc)
3317 return rc;
3318
3319 return current_has_perm(p, PROCESS__SETSCHED);
3320 }
3321
3322 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3323 {
3324 int rc;
3325
3326 rc = cap_task_setioprio(p, ioprio);
3327 if (rc)
3328 return rc;
3329
3330 return current_has_perm(p, PROCESS__SETSCHED);
3331 }
3332
3333 static int selinux_task_getioprio(struct task_struct *p)
3334 {
3335 return current_has_perm(p, PROCESS__GETSCHED);
3336 }
3337
3338 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
3339 struct rlimit *new_rlim)
3340 {
3341 struct rlimit *old_rlim = p->signal->rlim + resource;
3342
3343 /* Control the ability to change the hard limit (whether
3344 lowering or raising it), so that the hard limit can
3345 later be used as a safe reset point for the soft limit
3346 upon context transitions. See selinux_bprm_committing_creds. */
3347 if (old_rlim->rlim_max != new_rlim->rlim_max)
3348 return current_has_perm(p, PROCESS__SETRLIMIT);
3349
3350 return 0;
3351 }
3352
3353 static int selinux_task_setscheduler(struct task_struct *p)
3354 {
3355 int rc;
3356
3357 rc = cap_task_setscheduler(p);
3358 if (rc)
3359 return rc;
3360
3361 return current_has_perm(p, PROCESS__SETSCHED);
3362 }
3363
3364 static int selinux_task_getscheduler(struct task_struct *p)
3365 {
3366 return current_has_perm(p, PROCESS__GETSCHED);
3367 }
3368
3369 static int selinux_task_movememory(struct task_struct *p)
3370 {
3371 return current_has_perm(p, PROCESS__SETSCHED);
3372 }
3373
3374 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3375 int sig, u32 secid)
3376 {
3377 u32 perm;
3378 int rc;
3379
3380 if (!sig)
3381 perm = PROCESS__SIGNULL; /* null signal; existence test */
3382 else
3383 perm = signal_to_av(sig);
3384 if (secid)
3385 rc = avc_has_perm(secid, task_sid(p),
3386 SECCLASS_PROCESS, perm, NULL);
3387 else
3388 rc = current_has_perm(p, perm);
3389 return rc;
3390 }
3391
3392 static int selinux_task_wait(struct task_struct *p)
3393 {
3394 return task_has_perm(p, current, PROCESS__SIGCHLD);
3395 }
3396
3397 static void selinux_task_to_inode(struct task_struct *p,
3398 struct inode *inode)
3399 {
3400 struct inode_security_struct *isec = inode->i_security;
3401 u32 sid = task_sid(p);
3402
3403 isec->sid = sid;
3404 isec->initialized = 1;
3405 }
3406
3407 /* Returns error only if unable to parse addresses */
3408 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3409 struct common_audit_data *ad, u8 *proto)
3410 {
3411 int offset, ihlen, ret = -EINVAL;
3412 struct iphdr _iph, *ih;
3413
3414 offset = skb_network_offset(skb);
3415 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3416 if (ih == NULL)
3417 goto out;
3418
3419 ihlen = ih->ihl * 4;
3420 if (ihlen < sizeof(_iph))
3421 goto out;
3422
3423 ad->u.net.v4info.saddr = ih->saddr;
3424 ad->u.net.v4info.daddr = ih->daddr;
3425 ret = 0;
3426
3427 if (proto)
3428 *proto = ih->protocol;
3429
3430 switch (ih->protocol) {
3431 case IPPROTO_TCP: {
3432 struct tcphdr _tcph, *th;
3433
3434 if (ntohs(ih->frag_off) & IP_OFFSET)
3435 break;
3436
3437 offset += ihlen;
3438 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3439 if (th == NULL)
3440 break;
3441
3442 ad->u.net.sport = th->source;
3443 ad->u.net.dport = th->dest;
3444 break;
3445 }
3446
3447 case IPPROTO_UDP: {
3448 struct udphdr _udph, *uh;
3449
3450 if (ntohs(ih->frag_off) & IP_OFFSET)
3451 break;
3452
3453 offset += ihlen;
3454 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3455 if (uh == NULL)
3456 break;
3457
3458 ad->u.net.sport = uh->source;
3459 ad->u.net.dport = uh->dest;
3460 break;
3461 }
3462
3463 case IPPROTO_DCCP: {
3464 struct dccp_hdr _dccph, *dh;
3465
3466 if (ntohs(ih->frag_off) & IP_OFFSET)
3467 break;
3468
3469 offset += ihlen;
3470 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3471 if (dh == NULL)
3472 break;
3473
3474 ad->u.net.sport = dh->dccph_sport;
3475 ad->u.net.dport = dh->dccph_dport;
3476 break;
3477 }
3478
3479 default:
3480 break;
3481 }
3482 out:
3483 return ret;
3484 }
3485
3486 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3487
3488 /* Returns error only if unable to parse addresses */
3489 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3490 struct common_audit_data *ad, u8 *proto)
3491 {
3492 u8 nexthdr;
3493 int ret = -EINVAL, offset;
3494 struct ipv6hdr _ipv6h, *ip6;
3495
3496 offset = skb_network_offset(skb);
3497 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3498 if (ip6 == NULL)
3499 goto out;
3500
3501 ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr);
3502 ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr);
3503 ret = 0;
3504
3505 nexthdr = ip6->nexthdr;
3506 offset += sizeof(_ipv6h);
3507 offset = ipv6_skip_exthdr(skb, offset, &nexthdr);
3508 if (offset < 0)
3509 goto out;
3510
3511 if (proto)
3512 *proto = nexthdr;
3513
3514 switch (nexthdr) {
3515 case IPPROTO_TCP: {
3516 struct tcphdr _tcph, *th;
3517
3518 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3519 if (th == NULL)
3520 break;
3521
3522 ad->u.net.sport = th->source;
3523 ad->u.net.dport = th->dest;
3524 break;
3525 }
3526
3527 case IPPROTO_UDP: {
3528 struct udphdr _udph, *uh;
3529
3530 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3531 if (uh == NULL)
3532 break;
3533
3534 ad->u.net.sport = uh->source;
3535 ad->u.net.dport = uh->dest;
3536 break;
3537 }
3538
3539 case IPPROTO_DCCP: {
3540 struct dccp_hdr _dccph, *dh;
3541
3542 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3543 if (dh == NULL)
3544 break;
3545
3546 ad->u.net.sport = dh->dccph_sport;
3547 ad->u.net.dport = dh->dccph_dport;
3548 break;
3549 }
3550
3551 /* includes fragments */
3552 default:
3553 break;
3554 }
3555 out:
3556 return ret;
3557 }
3558
3559 #endif /* IPV6 */
3560
3561 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3562 char **_addrp, int src, u8 *proto)
3563 {
3564 char *addrp;
3565 int ret;
3566
3567 switch (ad->u.net.family) {
3568 case PF_INET:
3569 ret = selinux_parse_skb_ipv4(skb, ad, proto);
3570 if (ret)
3571 goto parse_error;
3572 addrp = (char *)(src ? &ad->u.net.v4info.saddr :
3573 &ad->u.net.v4info.daddr);
3574 goto okay;
3575
3576 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3577 case PF_INET6:
3578 ret = selinux_parse_skb_ipv6(skb, ad, proto);
3579 if (ret)
3580 goto parse_error;
3581 addrp = (char *)(src ? &ad->u.net.v6info.saddr :
3582 &ad->u.net.v6info.daddr);
3583 goto okay;
3584 #endif /* IPV6 */
3585 default:
3586 addrp = NULL;
3587 goto okay;
3588 }
3589
3590 parse_error:
3591 printk(KERN_WARNING
3592 "SELinux: failure in selinux_parse_skb(),"
3593 " unable to parse packet\n");
3594 return ret;
3595
3596 okay:
3597 if (_addrp)
3598 *_addrp = addrp;
3599 return 0;
3600 }
3601
3602 /**
3603 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3604 * @skb: the packet
3605 * @family: protocol family
3606 * @sid: the packet's peer label SID
3607 *
3608 * Description:
3609 * Check the various different forms of network peer labeling and determine
3610 * the peer label/SID for the packet; most of the magic actually occurs in
3611 * the security server function security_net_peersid_cmp(). The function
3612 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
3613 * or -EACCES if @sid is invalid due to inconsistencies with the different
3614 * peer labels.
3615 *
3616 */
3617 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3618 {
3619 int err;
3620 u32 xfrm_sid;
3621 u32 nlbl_sid;
3622 u32 nlbl_type;
3623
3624 selinux_skb_xfrm_sid(skb, &xfrm_sid);
3625 selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3626
3627 err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
3628 if (unlikely(err)) {
3629 printk(KERN_WARNING
3630 "SELinux: failure in selinux_skb_peerlbl_sid(),"
3631 " unable to determine packet's peer label\n");
3632 return -EACCES;
3633 }
3634
3635 return 0;
3636 }
3637
3638 /* socket security operations */
3639
3640 static u32 socket_sockcreate_sid(const struct task_security_struct *tsec)
3641 {
3642 return tsec->sockcreate_sid ? : tsec->sid;
3643 }
3644
3645 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
3646 {
3647 struct sk_security_struct *sksec = sk->sk_security;
3648 struct common_audit_data ad;
3649 u32 tsid = task_sid(task);
3650
3651 if (sksec->sid == SECINITSID_KERNEL)
3652 return 0;
3653
3654 COMMON_AUDIT_DATA_INIT(&ad, NET);
3655 ad.u.net.sk = sk;
3656
3657 return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
3658 }
3659
3660 static int selinux_socket_create(int family, int type,
3661 int protocol, int kern)
3662 {
3663 const struct task_security_struct *tsec = current_security();
3664 u32 newsid;
3665 u16 secclass;
3666
3667 if (kern)
3668 return 0;
3669
3670 newsid = socket_sockcreate_sid(tsec);
3671 secclass = socket_type_to_security_class(family, type, protocol);
3672 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
3673 }
3674
3675 static int selinux_socket_post_create(struct socket *sock, int family,
3676 int type, int protocol, int kern)
3677 {
3678 const struct task_security_struct *tsec = current_security();
3679 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
3680 struct sk_security_struct *sksec;
3681 int err = 0;
3682
3683 if (kern)
3684 isec->sid = SECINITSID_KERNEL;
3685 else
3686 isec->sid = socket_sockcreate_sid(tsec);
3687
3688 isec->sclass = socket_type_to_security_class(family, type, protocol);
3689 isec->initialized = 1;
3690
3691 if (sock->sk) {
3692 sksec = sock->sk->sk_security;
3693 sksec->sid = isec->sid;
3694 sksec->sclass = isec->sclass;
3695 err = selinux_netlbl_socket_post_create(sock->sk, family);
3696 }
3697
3698 return err;
3699 }
3700
3701 /* Range of port numbers used to automatically bind.
3702 Need to determine whether we should perform a name_bind
3703 permission check between the socket and the port number. */
3704
3705 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
3706 {
3707 struct sock *sk = sock->sk;
3708 u16 family;
3709 int err;
3710
3711 err = sock_has_perm(current, sk, SOCKET__BIND);
3712 if (err)
3713 goto out;
3714
3715 /*
3716 * If PF_INET or PF_INET6, check name_bind permission for the port.
3717 * Multiple address binding for SCTP is not supported yet: we just
3718 * check the first address now.
3719 */
3720 family = sk->sk_family;
3721 if (family == PF_INET || family == PF_INET6) {
3722 char *addrp;
3723 struct sk_security_struct *sksec = sk->sk_security;
3724 struct common_audit_data ad;
3725 struct sockaddr_in *addr4 = NULL;
3726 struct sockaddr_in6 *addr6 = NULL;
3727 unsigned short snum;
3728 u32 sid, node_perm;
3729
3730 if (family == PF_INET) {
3731 addr4 = (struct sockaddr_in *)address;
3732 snum = ntohs(addr4->sin_port);
3733 addrp = (char *)&addr4->sin_addr.s_addr;
3734 } else {
3735 addr6 = (struct sockaddr_in6 *)address;
3736 snum = ntohs(addr6->sin6_port);
3737 addrp = (char *)&addr6->sin6_addr.s6_addr;
3738 }
3739
3740 if (snum) {
3741 int low, high;
3742
3743 inet_get_local_port_range(&low, &high);
3744
3745 if (snum < max(PROT_SOCK, low) || snum > high) {
3746 err = sel_netport_sid(sk->sk_protocol,
3747 snum, &sid);
3748 if (err)
3749 goto out;
3750 COMMON_AUDIT_DATA_INIT(&ad, NET);
3751 ad.u.net.sport = htons(snum);
3752 ad.u.net.family = family;
3753 err = avc_has_perm(sksec->sid, sid,
3754 sksec->sclass,
3755 SOCKET__NAME_BIND, &ad);
3756 if (err)
3757 goto out;
3758 }
3759 }
3760
3761 switch (sksec->sclass) {
3762 case SECCLASS_TCP_SOCKET:
3763 node_perm = TCP_SOCKET__NODE_BIND;
3764 break;
3765
3766 case SECCLASS_UDP_SOCKET:
3767 node_perm = UDP_SOCKET__NODE_BIND;
3768 break;
3769
3770 case SECCLASS_DCCP_SOCKET:
3771 node_perm = DCCP_SOCKET__NODE_BIND;
3772 break;
3773
3774 default:
3775 node_perm = RAWIP_SOCKET__NODE_BIND;
3776 break;
3777 }
3778
3779 err = sel_netnode_sid(addrp, family, &sid);
3780 if (err)
3781 goto out;
3782
3783 COMMON_AUDIT_DATA_INIT(&ad, NET);
3784 ad.u.net.sport = htons(snum);
3785 ad.u.net.family = family;
3786
3787 if (family == PF_INET)
3788 ad.u.net.v4info.saddr = addr4->sin_addr.s_addr;
3789 else
3790 ipv6_addr_copy(&ad.u.net.v6info.saddr, &addr6->sin6_addr);
3791
3792 err = avc_has_perm(sksec->sid, sid,
3793 sksec->sclass, node_perm, &ad);
3794 if (err)
3795 goto out;
3796 }
3797 out:
3798 return err;
3799 }
3800
3801 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
3802 {
3803 struct sock *sk = sock->sk;
3804 struct sk_security_struct *sksec = sk->sk_security;
3805 int err;
3806
3807 err = sock_has_perm(current, sk, SOCKET__CONNECT);
3808 if (err)
3809 return err;
3810
3811 /*
3812 * If a TCP or DCCP socket, check name_connect permission for the port.
3813 */
3814 if (sksec->sclass == SECCLASS_TCP_SOCKET ||
3815 sksec->sclass == SECCLASS_DCCP_SOCKET) {
3816 struct common_audit_data ad;
3817 struct sockaddr_in *addr4 = NULL;
3818 struct sockaddr_in6 *addr6 = NULL;
3819 unsigned short snum;
3820 u32 sid, perm;
3821
3822 if (sk->sk_family == PF_INET) {
3823 addr4 = (struct sockaddr_in *)address;
3824 if (addrlen < sizeof(struct sockaddr_in))
3825 return -EINVAL;
3826 snum = ntohs(addr4->sin_port);
3827 } else {
3828 addr6 = (struct sockaddr_in6 *)address;
3829 if (addrlen < SIN6_LEN_RFC2133)
3830 return -EINVAL;
3831 snum = ntohs(addr6->sin6_port);
3832 }
3833
3834 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
3835 if (err)
3836 goto out;
3837
3838 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
3839 TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
3840
3841 COMMON_AUDIT_DATA_INIT(&ad, NET);
3842 ad.u.net.dport = htons(snum);
3843 ad.u.net.family = sk->sk_family;
3844 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
3845 if (err)
3846 goto out;
3847 }
3848
3849 err = selinux_netlbl_socket_connect(sk, address);
3850
3851 out:
3852 return err;
3853 }
3854
3855 static int selinux_socket_listen(struct socket *sock, int backlog)
3856 {
3857 return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
3858 }
3859
3860 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
3861 {
3862 int err;
3863 struct inode_security_struct *isec;
3864 struct inode_security_struct *newisec;
3865
3866 err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
3867 if (err)
3868 return err;
3869
3870 newisec = SOCK_INODE(newsock)->i_security;
3871
3872 isec = SOCK_INODE(sock)->i_security;
3873 newisec->sclass = isec->sclass;
3874 newisec->sid = isec->sid;
3875 newisec->initialized = 1;
3876
3877 return 0;
3878 }
3879
3880 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3881 int size)
3882 {
3883 return sock_has_perm(current, sock->sk, SOCKET__WRITE);
3884 }
3885
3886 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
3887 int size, int flags)
3888 {
3889 return sock_has_perm(current, sock->sk, SOCKET__READ);
3890 }
3891
3892 static int selinux_socket_getsockname(struct socket *sock)
3893 {
3894 return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
3895 }
3896
3897 static int selinux_socket_getpeername(struct socket *sock)
3898 {
3899 return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
3900 }
3901
3902 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
3903 {
3904 int err;
3905
3906 err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
3907 if (err)
3908 return err;
3909
3910 return selinux_netlbl_socket_setsockopt(sock, level, optname);
3911 }
3912
3913 static int selinux_socket_getsockopt(struct socket *sock, int level,
3914 int optname)
3915 {
3916 return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
3917 }
3918
3919 static int selinux_socket_shutdown(struct socket *sock, int how)
3920 {
3921 return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
3922 }
3923
3924 static int selinux_socket_unix_stream_connect(struct socket *sock,
3925 struct socket *other,
3926 struct sock *newsk)
3927 {
3928 struct sk_security_struct *sksec_sock = sock->sk->sk_security;
3929 struct sk_security_struct *sksec_other = other->sk->sk_security;
3930 struct sk_security_struct *sksec_new = newsk->sk_security;
3931 struct common_audit_data ad;
3932 int err;
3933
3934 COMMON_AUDIT_DATA_INIT(&ad, NET);
3935 ad.u.net.sk = other->sk;
3936
3937 err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
3938 sksec_other->sclass,
3939 UNIX_STREAM_SOCKET__CONNECTTO, &ad);
3940 if (err)
3941 return err;
3942
3943 /* server child socket */
3944 sksec_new->peer_sid = sksec_sock->sid;
3945 err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
3946 &sksec_new->sid);
3947 if (err)
3948 return err;
3949
3950 /* connecting socket */
3951 sksec_sock->peer_sid = sksec_new->sid;
3952
3953 return 0;
3954 }
3955
3956 static int selinux_socket_unix_may_send(struct socket *sock,
3957 struct socket *other)
3958 {
3959 struct sk_security_struct *ssec = sock->sk->sk_security;
3960 struct sk_security_struct *osec = other->sk->sk_security;
3961 struct common_audit_data ad;
3962
3963 COMMON_AUDIT_DATA_INIT(&ad, NET);
3964 ad.u.net.sk = other->sk;
3965
3966 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
3967 &ad);
3968 }
3969
3970 static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
3971 u32 peer_sid,
3972 struct common_audit_data *ad)
3973 {
3974 int err;
3975 u32 if_sid;
3976 u32 node_sid;
3977
3978 err = sel_netif_sid(ifindex, &if_sid);
3979 if (err)
3980 return err;
3981 err = avc_has_perm(peer_sid, if_sid,
3982 SECCLASS_NETIF, NETIF__INGRESS, ad);
3983 if (err)
3984 return err;
3985
3986 err = sel_netnode_sid(addrp, family, &node_sid);
3987 if (err)
3988 return err;
3989 return avc_has_perm(peer_sid, node_sid,
3990 SECCLASS_NODE, NODE__RECVFROM, ad);
3991 }
3992
3993 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
3994 u16 family)
3995 {
3996 int err = 0;
3997 struct sk_security_struct *sksec = sk->sk_security;
3998 u32 peer_sid;
3999 u32 sk_sid = sksec->sid;
4000 struct common_audit_data ad;
4001 char *addrp;
4002
4003 COMMON_AUDIT_DATA_INIT(&ad, NET);
4004 ad.u.net.netif = skb->skb_iif;
4005 ad.u.net.family = family;
4006 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4007 if (err)
4008 return err;
4009
4010 if (selinux_secmark_enabled()) {
4011 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4012 PACKET__RECV, &ad);
4013 if (err)
4014 return err;
4015 }
4016
4017 if (selinux_policycap_netpeer) {
4018 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4019 if (err)
4020 return err;
4021 err = avc_has_perm(sk_sid, peer_sid,
4022 SECCLASS_PEER, PEER__RECV, &ad);
4023 if (err)
4024 selinux_netlbl_err(skb, err, 0);
4025 } else {
4026 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4027 if (err)
4028 return err;
4029 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4030 }
4031
4032 return err;
4033 }
4034
4035 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4036 {
4037 int err;
4038 struct sk_security_struct *sksec = sk->sk_security;
4039 u16 family = sk->sk_family;
4040 u32 sk_sid = sksec->sid;
4041 struct common_audit_data ad;
4042 char *addrp;
4043 u8 secmark_active;
4044 u8 peerlbl_active;
4045
4046 if (family != PF_INET && family != PF_INET6)
4047 return 0;
4048
4049 /* Handle mapped IPv4 packets arriving via IPv6 sockets */
4050 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4051 family = PF_INET;
4052
4053 /* If any sort of compatibility mode is enabled then handoff processing
4054 * to the selinux_sock_rcv_skb_compat() function to deal with the
4055 * special handling. We do this in an attempt to keep this function
4056 * as fast and as clean as possible. */
4057 if (!selinux_policycap_netpeer)
4058 return selinux_sock_rcv_skb_compat(sk, skb, family);
4059
4060 secmark_active = selinux_secmark_enabled();
4061 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4062 if (!secmark_active && !peerlbl_active)
4063 return 0;
4064
4065 COMMON_AUDIT_DATA_INIT(&ad, NET);
4066 ad.u.net.netif = skb->skb_iif;
4067 ad.u.net.family = family;
4068 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4069 if (err)
4070 return err;
4071
4072 if (peerlbl_active) {
4073 u32 peer_sid;
4074
4075 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4076 if (err)
4077 return err;
4078 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
4079 peer_sid, &ad);
4080 if (err) {
4081 selinux_netlbl_err(skb, err, 0);
4082 return err;
4083 }
4084 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4085 PEER__RECV, &ad);
4086 if (err)
4087 selinux_netlbl_err(skb, err, 0);
4088 }
4089
4090 if (secmark_active) {
4091 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4092 PACKET__RECV, &ad);
4093 if (err)
4094 return err;
4095 }
4096
4097 return err;
4098 }
4099
4100 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4101 int __user *optlen, unsigned len)
4102 {
4103 int err = 0;
4104 char *scontext;
4105 u32 scontext_len;
4106 struct sk_security_struct *sksec = sock->sk->sk_security;
4107 u32 peer_sid = SECSID_NULL;
4108
4109 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4110 sksec->sclass == SECCLASS_TCP_SOCKET)
4111 peer_sid = sksec->peer_sid;
4112 if (peer_sid == SECSID_NULL)
4113 return -ENOPROTOOPT;
4114
4115 err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4116 if (err)
4117 return err;
4118
4119 if (scontext_len > len) {
4120 err = -ERANGE;
4121 goto out_len;
4122 }
4123
4124 if (copy_to_user(optval, scontext, scontext_len))
4125 err = -EFAULT;
4126
4127 out_len:
4128 if (put_user(scontext_len, optlen))
4129 err = -EFAULT;
4130 kfree(scontext);
4131 return err;
4132 }
4133
4134 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4135 {
4136 u32 peer_secid = SECSID_NULL;
4137 u16 family;
4138
4139 if (skb && skb->protocol == htons(ETH_P_IP))
4140 family = PF_INET;
4141 else if (skb && skb->protocol == htons(ETH_P_IPV6))
4142 family = PF_INET6;
4143 else if (sock)
4144 family = sock->sk->sk_family;
4145 else
4146 goto out;
4147
4148 if (sock && family == PF_UNIX)
4149 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4150 else if (skb)
4151 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4152
4153 out:
4154 *secid = peer_secid;
4155 if (peer_secid == SECSID_NULL)
4156 return -EINVAL;
4157 return 0;
4158 }
4159
4160 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4161 {
4162 struct sk_security_struct *sksec;
4163
4164 sksec = kzalloc(sizeof(*sksec), priority);
4165 if (!sksec)
4166 return -ENOMEM;
4167
4168 sksec->peer_sid = SECINITSID_UNLABELED;
4169 sksec->sid = SECINITSID_UNLABELED;
4170 selinux_netlbl_sk_security_reset(sksec);
4171 sk->sk_security = sksec;
4172
4173 return 0;
4174 }
4175
4176 static void selinux_sk_free_security(struct sock *sk)
4177 {
4178 struct sk_security_struct *sksec = sk->sk_security;
4179
4180 sk->sk_security = NULL;
4181 selinux_netlbl_sk_security_free(sksec);
4182 kfree(sksec);
4183 }
4184
4185 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4186 {
4187 struct sk_security_struct *sksec = sk->sk_security;
4188 struct sk_security_struct *newsksec = newsk->sk_security;
4189
4190 newsksec->sid = sksec->sid;
4191 newsksec->peer_sid = sksec->peer_sid;
4192 newsksec->sclass = sksec->sclass;
4193
4194 selinux_netlbl_sk_security_reset(newsksec);
4195 }
4196
4197 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4198 {
4199 if (!sk)
4200 *secid = SECINITSID_ANY_SOCKET;
4201 else {
4202 struct sk_security_struct *sksec = sk->sk_security;
4203
4204 *secid = sksec->sid;
4205 }
4206 }
4207
4208 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4209 {
4210 struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
4211 struct sk_security_struct *sksec = sk->sk_security;
4212
4213 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4214 sk->sk_family == PF_UNIX)
4215 isec->sid = sksec->sid;
4216 sksec->sclass = isec->sclass;
4217 }
4218
4219 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4220 struct request_sock *req)
4221 {
4222 struct sk_security_struct *sksec = sk->sk_security;
4223 int err;
4224 u16 family = sk->sk_family;
4225 u32 newsid;
4226 u32 peersid;
4227
4228 /* handle mapped IPv4 packets arriving via IPv6 sockets */
4229 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4230 family = PF_INET;
4231
4232 err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4233 if (err)
4234 return err;
4235 if (peersid == SECSID_NULL) {
4236 req->secid = sksec->sid;
4237 req->peer_secid = SECSID_NULL;
4238 } else {
4239 err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
4240 if (err)
4241 return err;
4242 req->secid = newsid;
4243 req->peer_secid = peersid;
4244 }
4245
4246 return selinux_netlbl_inet_conn_request(req, family);
4247 }
4248
4249 static void selinux_inet_csk_clone(struct sock *newsk,
4250 const struct request_sock *req)
4251 {
4252 struct sk_security_struct *newsksec = newsk->sk_security;
4253
4254 newsksec->sid = req->secid;
4255 newsksec->peer_sid = req->peer_secid;
4256 /* NOTE: Ideally, we should also get the isec->sid for the
4257 new socket in sync, but we don't have the isec available yet.
4258 So we will wait until sock_graft to do it, by which
4259 time it will have been created and available. */
4260
4261 /* We don't need to take any sort of lock here as we are the only
4262 * thread with access to newsksec */
4263 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4264 }
4265
4266 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4267 {
4268 u16 family = sk->sk_family;
4269 struct sk_security_struct *sksec = sk->sk_security;
4270
4271 /* handle mapped IPv4 packets arriving via IPv6 sockets */
4272 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4273 family = PF_INET;
4274
4275 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4276 }
4277
4278 static int selinux_secmark_relabel_packet(u32 sid)
4279 {
4280 const struct task_security_struct *__tsec;
4281 u32 tsid;
4282
4283 __tsec = current_security();
4284 tsid = __tsec->sid;
4285
4286 return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
4287 }
4288
4289 static void selinux_secmark_refcount_inc(void)
4290 {
4291 atomic_inc(&selinux_secmark_refcount);
4292 }
4293
4294 static void selinux_secmark_refcount_dec(void)
4295 {
4296 atomic_dec(&selinux_secmark_refcount);
4297 }
4298
4299 static void selinux_req_classify_flow(const struct request_sock *req,
4300 struct flowi *fl)
4301 {
4302 fl->secid = req->secid;
4303 }
4304
4305 static int selinux_tun_dev_create(void)
4306 {
4307 u32 sid = current_sid();
4308
4309 /* we aren't taking into account the "sockcreate" SID since the socket
4310 * that is being created here is not a socket in the traditional sense,
4311 * instead it is a private sock, accessible only to the kernel, and
4312 * representing a wide range of network traffic spanning multiple
4313 * connections unlike traditional sockets - check the TUN driver to
4314 * get a better understanding of why this socket is special */
4315
4316 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4317 NULL);
4318 }
4319
4320 static void selinux_tun_dev_post_create(struct sock *sk)
4321 {
4322 struct sk_security_struct *sksec = sk->sk_security;
4323
4324 /* we don't currently perform any NetLabel based labeling here and it
4325 * isn't clear that we would want to do so anyway; while we could apply
4326 * labeling without the support of the TUN user the resulting labeled
4327 * traffic from the other end of the connection would almost certainly
4328 * cause confusion to the TUN user that had no idea network labeling
4329 * protocols were being used */
4330
4331 /* see the comments in selinux_tun_dev_create() about why we don't use
4332 * the sockcreate SID here */
4333
4334 sksec->sid = current_sid();
4335 sksec->sclass = SECCLASS_TUN_SOCKET;
4336 }
4337
4338 static int selinux_tun_dev_attach(struct sock *sk)
4339 {
4340 struct sk_security_struct *sksec = sk->sk_security;
4341 u32 sid = current_sid();
4342 int err;
4343
4344 err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET,
4345 TUN_SOCKET__RELABELFROM, NULL);
4346 if (err)
4347 return err;
4348 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4349 TUN_SOCKET__RELABELTO, NULL);
4350 if (err)
4351 return err;
4352
4353 sksec->sid = sid;
4354
4355 return 0;
4356 }
4357
4358 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4359 {
4360 int err = 0;
4361 u32 perm;
4362 struct nlmsghdr *nlh;
4363 struct sk_security_struct *sksec = sk->sk_security;
4364
4365 if (skb->len < NLMSG_SPACE(0)) {
4366 err = -EINVAL;
4367 goto out;
4368 }
4369 nlh = nlmsg_hdr(skb);
4370
4371 err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
4372 if (err) {
4373 if (err == -EINVAL) {
4374 audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
4375 "SELinux: unrecognized netlink message"
4376 " type=%hu for sclass=%hu\n",
4377 nlh->nlmsg_type, sksec->sclass);
4378 if (!selinux_enforcing || security_get_allow_unknown())
4379 err = 0;
4380 }
4381
4382 /* Ignore */
4383 if (err == -ENOENT)
4384 err = 0;
4385 goto out;
4386 }
4387
4388 err = sock_has_perm(current, sk, perm);
4389 out:
4390 return err;
4391 }
4392
4393 #ifdef CONFIG_NETFILTER
4394
4395 static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
4396 u16 family)
4397 {
4398 int err;
4399 char *addrp;
4400 u32 peer_sid;
4401 struct common_audit_data ad;
4402 u8 secmark_active;
4403 u8 netlbl_active;
4404 u8 peerlbl_active;
4405
4406 if (!selinux_policycap_netpeer)
4407 return NF_ACCEPT;
4408
4409 secmark_active = selinux_secmark_enabled();
4410 netlbl_active = netlbl_enabled();
4411 peerlbl_active = netlbl_active || selinux_xfrm_enabled();
4412 if (!secmark_active && !peerlbl_active)
4413 return NF_ACCEPT;
4414
4415 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
4416 return NF_DROP;
4417
4418 COMMON_AUDIT_DATA_INIT(&ad, NET);
4419 ad.u.net.netif = ifindex;
4420 ad.u.net.family = family;
4421 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
4422 return NF_DROP;
4423
4424 if (peerlbl_active) {
4425 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
4426 peer_sid, &ad);
4427 if (err) {
4428 selinux_netlbl_err(skb, err, 1);
4429 return NF_DROP;
4430 }
4431 }
4432
4433 if (secmark_active)
4434 if (avc_has_perm(peer_sid, skb->secmark,
4435 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
4436 return NF_DROP;
4437
4438 if (netlbl_active)
4439 /* we do this in the FORWARD path and not the POST_ROUTING
4440 * path because we want to make sure we apply the necessary
4441 * labeling before IPsec is applied so we can leverage AH
4442 * protection */
4443 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
4444 return NF_DROP;
4445
4446 return NF_ACCEPT;
4447 }
4448
4449 static unsigned int selinux_ipv4_forward(unsigned int hooknum,
4450 struct sk_buff *skb,
4451 const struct net_device *in,
4452 const struct net_device *out,
4453 int (*okfn)(struct sk_buff *))
4454 {
4455 return selinux_ip_forward(skb, in->ifindex, PF_INET);
4456 }
4457
4458 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4459 static unsigned int selinux_ipv6_forward(unsigned int hooknum,
4460 struct sk_buff *skb,
4461 const struct net_device *in,
4462 const struct net_device *out,
4463 int (*okfn)(struct sk_buff *))
4464 {
4465 return selinux_ip_forward(skb, in->ifindex, PF_INET6);
4466 }
4467 #endif /* IPV6 */
4468
4469 static unsigned int selinux_ip_output(struct sk_buff *skb,
4470 u16 family)
4471 {
4472 u32 sid;
4473
4474 if (!netlbl_enabled())
4475 return NF_ACCEPT;
4476
4477 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
4478 * because we want to make sure we apply the necessary labeling
4479 * before IPsec is applied so we can leverage AH protection */
4480 if (skb->sk) {
4481 struct sk_security_struct *sksec = skb->sk->sk_security;
4482 sid = sksec->sid;
4483 } else
4484 sid = SECINITSID_KERNEL;
4485 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
4486 return NF_DROP;
4487
4488 return NF_ACCEPT;
4489 }
4490
4491 static unsigned int selinux_ipv4_output(unsigned int hooknum,
4492 struct sk_buff *skb,
4493 const struct net_device *in,
4494 const struct net_device *out,
4495 int (*okfn)(struct sk_buff *))
4496 {
4497 return selinux_ip_output(skb, PF_INET);
4498 }
4499
4500 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
4501 int ifindex,
4502 u16 family)
4503 {
4504 struct sock *sk = skb->sk;
4505 struct sk_security_struct *sksec;
4506 struct common_audit_data ad;
4507 char *addrp;
4508 u8 proto;
4509
4510 if (sk == NULL)
4511 return NF_ACCEPT;
4512 sksec = sk->sk_security;
4513
4514 COMMON_AUDIT_DATA_INIT(&ad, NET);
4515 ad.u.net.netif = ifindex;
4516 ad.u.net.family = family;
4517 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
4518 return NF_DROP;
4519
4520 if (selinux_secmark_enabled())
4521 if (avc_has_perm(sksec->sid, skb->secmark,
4522 SECCLASS_PACKET, PACKET__SEND, &ad))
4523 return NF_DROP_ERR(-ECONNREFUSED);
4524
4525 if (selinux_policycap_netpeer)
4526 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
4527 return NF_DROP_ERR(-ECONNREFUSED);
4528
4529 return NF_ACCEPT;
4530 }
4531
4532 static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
4533 u16 family)
4534 {
4535 u32 secmark_perm;
4536 u32 peer_sid;
4537 struct sock *sk;
4538 struct common_audit_data ad;
4539 char *addrp;
4540 u8 secmark_active;
4541 u8 peerlbl_active;
4542
4543 /* If any sort of compatibility mode is enabled then handoff processing
4544 * to the selinux_ip_postroute_compat() function to deal with the
4545 * special handling. We do this in an attempt to keep this function
4546 * as fast and as clean as possible. */
4547 if (!selinux_policycap_netpeer)
4548 return selinux_ip_postroute_compat(skb, ifindex, family);
4549 #ifdef CONFIG_XFRM
4550 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
4551 * packet transformation so allow the packet to pass without any checks
4552 * since we'll have another chance to perform access control checks
4553 * when the packet is on it's final way out.
4554 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
4555 * is NULL, in this case go ahead and apply access control. */
4556 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
4557 return NF_ACCEPT;
4558 #endif
4559 secmark_active = selinux_secmark_enabled();
4560 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4561 if (!secmark_active && !peerlbl_active)
4562 return NF_ACCEPT;
4563
4564 /* if the packet is being forwarded then get the peer label from the
4565 * packet itself; otherwise check to see if it is from a local
4566 * application or the kernel, if from an application get the peer label
4567 * from the sending socket, otherwise use the kernel's sid */
4568 sk = skb->sk;
4569 if (sk == NULL) {
4570 switch (family) {
4571 case PF_INET:
4572 if (IPCB(skb)->flags & IPSKB_FORWARDED)
4573 secmark_perm = PACKET__FORWARD_OUT;
4574 else
4575 secmark_perm = PACKET__SEND;
4576 break;
4577 case PF_INET6:
4578 if (IP6CB(skb)->flags & IP6SKB_FORWARDED)
4579 secmark_perm = PACKET__FORWARD_OUT;
4580 else
4581 secmark_perm = PACKET__SEND;
4582 break;
4583 default:
4584 return NF_DROP_ERR(-ECONNREFUSED);
4585 }
4586 if (secmark_perm == PACKET__FORWARD_OUT) {
4587 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4588 return NF_DROP;
4589 } else
4590 peer_sid = SECINITSID_KERNEL;
4591 } else {
4592 struct sk_security_struct *sksec = sk->sk_security;
4593 peer_sid = sksec->sid;
4594 secmark_perm = PACKET__SEND;
4595 }
4596
4597 COMMON_AUDIT_DATA_INIT(&ad, NET);
4598 ad.u.net.netif = ifindex;
4599 ad.u.net.family = family;
4600 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4601 return NF_DROP;
4602
4603 if (secmark_active)
4604 if (avc_has_perm(peer_sid, skb->secmark,
4605 SECCLASS_PACKET, secmark_perm, &ad))
4606 return NF_DROP_ERR(-ECONNREFUSED);
4607
4608 if (peerlbl_active) {
4609 u32 if_sid;
4610 u32 node_sid;
4611
4612 if (sel_netif_sid(ifindex, &if_sid))
4613 return NF_DROP;
4614 if (avc_has_perm(peer_sid, if_sid,
4615 SECCLASS_NETIF, NETIF__EGRESS, &ad))
4616 return NF_DROP_ERR(-ECONNREFUSED);
4617
4618 if (sel_netnode_sid(addrp, family, &node_sid))
4619 return NF_DROP;
4620 if (avc_has_perm(peer_sid, node_sid,
4621 SECCLASS_NODE, NODE__SENDTO, &ad))
4622 return NF_DROP_ERR(-ECONNREFUSED);
4623 }
4624
4625 return NF_ACCEPT;
4626 }
4627
4628 static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
4629 struct sk_buff *skb,
4630 const struct net_device *in,
4631 const struct net_device *out,
4632 int (*okfn)(struct sk_buff *))
4633 {
4634 return selinux_ip_postroute(skb, out->ifindex, PF_INET);
4635 }
4636
4637 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4638 static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
4639 struct sk_buff *skb,
4640 const struct net_device *in,
4641 const struct net_device *out,
4642 int (*okfn)(struct sk_buff *))
4643 {
4644 return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
4645 }
4646 #endif /* IPV6 */
4647
4648 #endif /* CONFIG_NETFILTER */
4649
4650 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
4651 {
4652 int err;
4653
4654 err = cap_netlink_send(sk, skb);
4655 if (err)
4656 return err;
4657
4658 return selinux_nlmsg_perm(sk, skb);
4659 }
4660
4661 static int selinux_netlink_recv(struct sk_buff *skb, int capability)
4662 {
4663 int err;
4664 struct common_audit_data ad;
4665
4666 err = cap_netlink_recv(skb, capability);
4667 if (err)
4668 return err;
4669
4670 COMMON_AUDIT_DATA_INIT(&ad, CAP);
4671 ad.u.cap = capability;
4672
4673 return avc_has_perm(NETLINK_CB(skb).sid, NETLINK_CB(skb).sid,
4674 SECCLASS_CAPABILITY, CAP_TO_MASK(capability), &ad);
4675 }
4676
4677 static int ipc_alloc_security(struct task_struct *task,
4678 struct kern_ipc_perm *perm,
4679 u16 sclass)
4680 {
4681 struct ipc_security_struct *isec;
4682 u32 sid;
4683
4684 isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
4685 if (!isec)
4686 return -ENOMEM;
4687
4688 sid = task_sid(task);
4689 isec->sclass = sclass;
4690 isec->sid = sid;
4691 perm->security = isec;
4692
4693 return 0;
4694 }
4695
4696 static void ipc_free_security(struct kern_ipc_perm *perm)
4697 {
4698 struct ipc_security_struct *isec = perm->security;
4699 perm->security = NULL;
4700 kfree(isec);
4701 }
4702
4703 static int msg_msg_alloc_security(struct msg_msg *msg)
4704 {
4705 struct msg_security_struct *msec;
4706
4707 msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
4708 if (!msec)
4709 return -ENOMEM;
4710
4711 msec->sid = SECINITSID_UNLABELED;
4712 msg->security = msec;
4713
4714 return 0;
4715 }
4716
4717 static void msg_msg_free_security(struct msg_msg *msg)
4718 {
4719 struct msg_security_struct *msec = msg->security;
4720
4721 msg->security = NULL;
4722 kfree(msec);
4723 }
4724
4725 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
4726 u32 perms)
4727 {
4728 struct ipc_security_struct *isec;
4729 struct common_audit_data ad;
4730 u32 sid = current_sid();
4731
4732 isec = ipc_perms->security;
4733
4734 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4735 ad.u.ipc_id = ipc_perms->key;
4736
4737 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
4738 }
4739
4740 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
4741 {
4742 return msg_msg_alloc_security(msg);
4743 }
4744
4745 static void selinux_msg_msg_free_security(struct msg_msg *msg)
4746 {
4747 msg_msg_free_security(msg);
4748 }
4749
4750 /* message queue security operations */
4751 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
4752 {
4753 struct ipc_security_struct *isec;
4754 struct common_audit_data ad;
4755 u32 sid = current_sid();
4756 int rc;
4757
4758 rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
4759 if (rc)
4760 return rc;
4761
4762 isec = msq->q_perm.security;
4763
4764 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4765 ad.u.ipc_id = msq->q_perm.key;
4766
4767 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4768 MSGQ__CREATE, &ad);
4769 if (rc) {
4770 ipc_free_security(&msq->q_perm);
4771 return rc;
4772 }
4773 return 0;
4774 }
4775
4776 static void selinux_msg_queue_free_security(struct msg_queue *msq)
4777 {
4778 ipc_free_security(&msq->q_perm);
4779 }
4780
4781 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
4782 {
4783 struct ipc_security_struct *isec;
4784 struct common_audit_data ad;
4785 u32 sid = current_sid();
4786
4787 isec = msq->q_perm.security;
4788
4789 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4790 ad.u.ipc_id = msq->q_perm.key;
4791
4792 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4793 MSGQ__ASSOCIATE, &ad);
4794 }
4795
4796 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
4797 {
4798 int err;
4799 int perms;
4800
4801 switch (cmd) {
4802 case IPC_INFO:
4803 case MSG_INFO:
4804 /* No specific object, just general system-wide information. */
4805 return task_has_system(current, SYSTEM__IPC_INFO);
4806 case IPC_STAT:
4807 case MSG_STAT:
4808 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
4809 break;
4810 case IPC_SET:
4811 perms = MSGQ__SETATTR;
4812 break;
4813 case IPC_RMID:
4814 perms = MSGQ__DESTROY;
4815 break;
4816 default:
4817 return 0;
4818 }
4819
4820 err = ipc_has_perm(&msq->q_perm, perms);
4821 return err;
4822 }
4823
4824 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
4825 {
4826 struct ipc_security_struct *isec;
4827 struct msg_security_struct *msec;
4828 struct common_audit_data ad;
4829 u32 sid = current_sid();
4830 int rc;
4831
4832 isec = msq->q_perm.security;
4833 msec = msg->security;
4834
4835 /*
4836 * First time through, need to assign label to the message
4837 */
4838 if (msec->sid == SECINITSID_UNLABELED) {
4839 /*
4840 * Compute new sid based on current process and
4841 * message queue this message will be stored in
4842 */
4843 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
4844 &msec->sid);
4845 if (rc)
4846 return rc;
4847 }
4848
4849 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4850 ad.u.ipc_id = msq->q_perm.key;
4851
4852 /* Can this process write to the queue? */
4853 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4854 MSGQ__WRITE, &ad);
4855 if (!rc)
4856 /* Can this process send the message */
4857 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
4858 MSG__SEND, &ad);
4859 if (!rc)
4860 /* Can the message be put in the queue? */
4861 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
4862 MSGQ__ENQUEUE, &ad);
4863
4864 return rc;
4865 }
4866
4867 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
4868 struct task_struct *target,
4869 long type, int mode)
4870 {
4871 struct ipc_security_struct *isec;
4872 struct msg_security_struct *msec;
4873 struct common_audit_data ad;
4874 u32 sid = task_sid(target);
4875 int rc;
4876
4877 isec = msq->q_perm.security;
4878 msec = msg->security;
4879
4880 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4881 ad.u.ipc_id = msq->q_perm.key;
4882
4883 rc = avc_has_perm(sid, isec->sid,
4884 SECCLASS_MSGQ, MSGQ__READ, &ad);
4885 if (!rc)
4886 rc = avc_has_perm(sid, msec->sid,
4887 SECCLASS_MSG, MSG__RECEIVE, &ad);
4888 return rc;
4889 }
4890
4891 /* Shared Memory security operations */
4892 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
4893 {
4894 struct ipc_security_struct *isec;
4895 struct common_audit_data ad;
4896 u32 sid = current_sid();
4897 int rc;
4898
4899 rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
4900 if (rc)
4901 return rc;
4902
4903 isec = shp->shm_perm.security;
4904
4905 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4906 ad.u.ipc_id = shp->shm_perm.key;
4907
4908 rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
4909 SHM__CREATE, &ad);
4910 if (rc) {
4911 ipc_free_security(&shp->shm_perm);
4912 return rc;
4913 }
4914 return 0;
4915 }
4916
4917 static void selinux_shm_free_security(struct shmid_kernel *shp)
4918 {
4919 ipc_free_security(&shp->shm_perm);
4920 }
4921
4922 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
4923 {
4924 struct ipc_security_struct *isec;
4925 struct common_audit_data ad;
4926 u32 sid = current_sid();
4927
4928 isec = shp->shm_perm.security;
4929
4930 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4931 ad.u.ipc_id = shp->shm_perm.key;
4932
4933 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
4934 SHM__ASSOCIATE, &ad);
4935 }
4936
4937 /* Note, at this point, shp is locked down */
4938 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
4939 {
4940 int perms;
4941 int err;
4942
4943 switch (cmd) {
4944 case IPC_INFO:
4945 case SHM_INFO:
4946 /* No specific object, just general system-wide information. */
4947 return task_has_system(current, SYSTEM__IPC_INFO);
4948 case IPC_STAT:
4949 case SHM_STAT:
4950 perms = SHM__GETATTR | SHM__ASSOCIATE;
4951 break;
4952 case IPC_SET:
4953 perms = SHM__SETATTR;
4954 break;
4955 case SHM_LOCK:
4956 case SHM_UNLOCK:
4957 perms = SHM__LOCK;
4958 break;
4959 case IPC_RMID:
4960 perms = SHM__DESTROY;
4961 break;
4962 default:
4963 return 0;
4964 }
4965
4966 err = ipc_has_perm(&shp->shm_perm, perms);
4967 return err;
4968 }
4969
4970 static int selinux_shm_shmat(struct shmid_kernel *shp,
4971 char __user *shmaddr, int shmflg)
4972 {
4973 u32 perms;
4974
4975 if (shmflg & SHM_RDONLY)
4976 perms = SHM__READ;
4977 else
4978 perms = SHM__READ | SHM__WRITE;
4979
4980 return ipc_has_perm(&shp->shm_perm, perms);
4981 }
4982
4983 /* Semaphore security operations */
4984 static int selinux_sem_alloc_security(struct sem_array *sma)
4985 {
4986 struct ipc_security_struct *isec;
4987 struct common_audit_data ad;
4988 u32 sid = current_sid();
4989 int rc;
4990
4991 rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
4992 if (rc)
4993 return rc;
4994
4995 isec = sma->sem_perm.security;
4996
4997 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4998 ad.u.ipc_id = sma->sem_perm.key;
4999
5000 rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5001 SEM__CREATE, &ad);
5002 if (rc) {
5003 ipc_free_security(&sma->sem_perm);
5004 return rc;
5005 }
5006 return 0;
5007 }
5008
5009 static void selinux_sem_free_security(struct sem_array *sma)
5010 {
5011 ipc_free_security(&sma->sem_perm);
5012 }
5013
5014 static int selinux_sem_associate(struct sem_array *sma, int semflg)
5015 {
5016 struct ipc_security_struct *isec;
5017 struct common_audit_data ad;
5018 u32 sid = current_sid();
5019
5020 isec = sma->sem_perm.security;
5021
5022 COMMON_AUDIT_DATA_INIT(&ad, IPC);
5023 ad.u.ipc_id = sma->sem_perm.key;
5024
5025 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5026 SEM__ASSOCIATE, &ad);
5027 }
5028
5029 /* Note, at this point, sma is locked down */
5030 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5031 {
5032 int err;
5033 u32 perms;
5034
5035 switch (cmd) {
5036 case IPC_INFO:
5037 case SEM_INFO:
5038 /* No specific object, just general system-wide information. */
5039 return task_has_system(current, SYSTEM__IPC_INFO);
5040 case GETPID:
5041 case GETNCNT:
5042 case GETZCNT:
5043 perms = SEM__GETATTR;
5044 break;
5045 case GETVAL:
5046 case GETALL:
5047 perms = SEM__READ;
5048 break;
5049 case SETVAL:
5050 case SETALL:
5051 perms = SEM__WRITE;
5052 break;
5053 case IPC_RMID:
5054 perms = SEM__DESTROY;
5055 break;
5056 case IPC_SET:
5057 perms = SEM__SETATTR;
5058 break;
5059 case IPC_STAT:
5060 case SEM_STAT:
5061 perms = SEM__GETATTR | SEM__ASSOCIATE;
5062 break;
5063 default:
5064 return 0;
5065 }
5066
5067 err = ipc_has_perm(&sma->sem_perm, perms);
5068 return err;
5069 }
5070
5071 static int selinux_sem_semop(struct sem_array *sma,
5072 struct sembuf *sops, unsigned nsops, int alter)
5073 {
5074 u32 perms;
5075
5076 if (alter)
5077 perms = SEM__READ | SEM__WRITE;
5078 else
5079 perms = SEM__READ;
5080
5081 return ipc_has_perm(&sma->sem_perm, perms);
5082 }
5083
5084 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5085 {
5086 u32 av = 0;
5087
5088 av = 0;
5089 if (flag & S_IRUGO)
5090 av |= IPC__UNIX_READ;
5091 if (flag & S_IWUGO)
5092 av |= IPC__UNIX_WRITE;
5093
5094 if (av == 0)
5095 return 0;
5096
5097 return ipc_has_perm(ipcp, av);
5098 }
5099
5100 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5101 {
5102 struct ipc_security_struct *isec = ipcp->security;
5103 *secid = isec->sid;
5104 }
5105
5106 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5107 {
5108 if (inode)
5109 inode_doinit_with_dentry(inode, dentry);
5110 }
5111
5112 static int selinux_getprocattr(struct task_struct *p,
5113 char *name, char **value)
5114 {
5115 const struct task_security_struct *__tsec;
5116 u32 sid;
5117 int error;
5118 unsigned len;
5119
5120 if (current != p) {
5121 error = current_has_perm(p, PROCESS__GETATTR);
5122 if (error)
5123 return error;
5124 }
5125
5126 rcu_read_lock();
5127 __tsec = __task_cred(p)->security;
5128
5129 if (!strcmp(name, "current"))
5130 sid = __tsec->sid;
5131 else if (!strcmp(name, "prev"))
5132 sid = __tsec->osid;
5133 else if (!strcmp(name, "exec"))
5134 sid = __tsec->exec_sid;
5135 else if (!strcmp(name, "fscreate"))
5136 sid = __tsec->create_sid;
5137 else if (!strcmp(name, "keycreate"))
5138 sid = __tsec->keycreate_sid;
5139 else if (!strcmp(name, "sockcreate"))
5140 sid = __tsec->sockcreate_sid;
5141 else
5142 goto invalid;
5143 rcu_read_unlock();
5144
5145 if (!sid)
5146 return 0;
5147
5148 error = security_sid_to_context(sid, value, &len);
5149 if (error)
5150 return error;
5151 return len;
5152
5153 invalid:
5154 rcu_read_unlock();
5155 return -EINVAL;
5156 }
5157
5158 static int selinux_setprocattr(struct task_struct *p,
5159 char *name, void *value, size_t size)
5160 {
5161 struct task_security_struct *tsec;
5162 struct task_struct *tracer;
5163 struct cred *new;
5164 u32 sid = 0, ptsid;
5165 int error;
5166 char *str = value;
5167
5168 if (current != p) {
5169 /* SELinux only allows a process to change its own
5170 security attributes. */
5171 return -EACCES;
5172 }
5173
5174 /*
5175 * Basic control over ability to set these attributes at all.
5176 * current == p, but we'll pass them separately in case the
5177 * above restriction is ever removed.
5178 */
5179 if (!strcmp(name, "exec"))
5180 error = current_has_perm(p, PROCESS__SETEXEC);
5181 else if (!strcmp(name, "fscreate"))
5182 error = current_has_perm(p, PROCESS__SETFSCREATE);
5183 else if (!strcmp(name, "keycreate"))
5184 error = current_has_perm(p, PROCESS__SETKEYCREATE);
5185 else if (!strcmp(name, "sockcreate"))
5186 error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5187 else if (!strcmp(name, "current"))
5188 error = current_has_perm(p, PROCESS__SETCURRENT);
5189 else
5190 error = -EINVAL;
5191 if (error)
5192 return error;
5193
5194 /* Obtain a SID for the context, if one was specified. */
5195 if (size && str[1] && str[1] != '\n') {
5196 if (str[size-1] == '\n') {
5197 str[size-1] = 0;
5198 size--;
5199 }
5200 error = security_context_to_sid(value, size, &sid);
5201 if (error == -EINVAL && !strcmp(name, "fscreate")) {
5202 if (!capable(CAP_MAC_ADMIN))
5203 return error;
5204 error = security_context_to_sid_force(value, size,
5205 &sid);
5206 }
5207 if (error)
5208 return error;
5209 }
5210
5211 new = prepare_creds();
5212 if (!new)
5213 return -ENOMEM;
5214
5215 /* Permission checking based on the specified context is
5216 performed during the actual operation (execve,
5217 open/mkdir/...), when we know the full context of the
5218 operation. See selinux_bprm_set_creds for the execve
5219 checks and may_create for the file creation checks. The
5220 operation will then fail if the context is not permitted. */
5221 tsec = new->security;
5222 if (!strcmp(name, "exec")) {
5223 tsec->exec_sid = sid;
5224 } else if (!strcmp(name, "fscreate")) {
5225 tsec->create_sid = sid;
5226 } else if (!strcmp(name, "keycreate")) {
5227 error = may_create_key(sid, p);
5228 if (error)
5229 goto abort_change;
5230 tsec->keycreate_sid = sid;
5231 } else if (!strcmp(name, "sockcreate")) {
5232 tsec->sockcreate_sid = sid;
5233 } else if (!strcmp(name, "current")) {
5234 error = -EINVAL;
5235 if (sid == 0)
5236 goto abort_change;
5237
5238 /* Only allow single threaded processes to change context */
5239 error = -EPERM;
5240 if (!current_is_single_threaded()) {
5241 error = security_bounded_transition(tsec->sid, sid);
5242 if (error)
5243 goto abort_change;
5244 }
5245
5246 /* Check permissions for the transition. */
5247 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5248 PROCESS__DYNTRANSITION, NULL);
5249 if (error)
5250 goto abort_change;
5251
5252 /* Check for ptracing, and update the task SID if ok.
5253 Otherwise, leave SID unchanged and fail. */
5254 ptsid = 0;
5255 task_lock(p);
5256 tracer = tracehook_tracer_task(p);
5257 if (tracer)
5258 ptsid = task_sid(tracer);
5259 task_unlock(p);
5260
5261 if (tracer) {
5262 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5263 PROCESS__PTRACE, NULL);
5264 if (error)
5265 goto abort_change;
5266 }
5267
5268 tsec->sid = sid;
5269 } else {
5270 error = -EINVAL;
5271 goto abort_change;
5272 }
5273
5274 commit_creds(new);
5275 return size;
5276
5277 abort_change:
5278 abort_creds(new);
5279 return error;
5280 }
5281
5282 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5283 {
5284 return security_sid_to_context(secid, secdata, seclen);
5285 }
5286
5287 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5288 {
5289 return security_context_to_sid(secdata, seclen, secid);
5290 }
5291
5292 static void selinux_release_secctx(char *secdata, u32 seclen)
5293 {
5294 kfree(secdata);
5295 }
5296
5297 /*
5298 * called with inode->i_mutex locked
5299 */
5300 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5301 {
5302 return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5303 }
5304
5305 /*
5306 * called with inode->i_mutex locked
5307 */
5308 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
5309 {
5310 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
5311 }
5312
5313 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
5314 {
5315 int len = 0;
5316 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
5317 ctx, true);
5318 if (len < 0)
5319 return len;
5320 *ctxlen = len;
5321 return 0;
5322 }
5323 #ifdef CONFIG_KEYS
5324
5325 static int selinux_key_alloc(struct key *k, const struct cred *cred,
5326 unsigned long flags)
5327 {
5328 const struct task_security_struct *tsec;
5329 struct key_security_struct *ksec;
5330
5331 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
5332 if (!ksec)
5333 return -ENOMEM;
5334
5335 tsec = cred->security;
5336 if (tsec->keycreate_sid)
5337 ksec->sid = tsec->keycreate_sid;
5338 else
5339 ksec->sid = tsec->sid;
5340
5341 k->security = ksec;
5342 return 0;
5343 }
5344
5345 static void selinux_key_free(struct key *k)
5346 {
5347 struct key_security_struct *ksec = k->security;
5348
5349 k->security = NULL;
5350 kfree(ksec);
5351 }
5352
5353 static int selinux_key_permission(key_ref_t key_ref,
5354 const struct cred *cred,
5355 key_perm_t perm)
5356 {
5357 struct key *key;
5358 struct key_security_struct *ksec;
5359 u32 sid;
5360
5361 /* if no specific permissions are requested, we skip the
5362 permission check. No serious, additional covert channels
5363 appear to be created. */
5364 if (perm == 0)
5365 return 0;
5366
5367 sid = cred_sid(cred);
5368
5369 key = key_ref_to_ptr(key_ref);
5370 ksec = key->security;
5371
5372 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5373 }
5374
5375 static int selinux_key_getsecurity(struct key *key, char **_buffer)
5376 {
5377 struct key_security_struct *ksec = key->security;
5378 char *context = NULL;
5379 unsigned len;
5380 int rc;
5381
5382 rc = security_sid_to_context(ksec->sid, &context, &len);
5383 if (!rc)
5384 rc = len;
5385 *_buffer = context;
5386 return rc;
5387 }
5388
5389 #endif
5390
5391 static struct security_operations selinux_ops = {
5392 .name = "selinux",
5393
5394 .ptrace_access_check = selinux_ptrace_access_check,
5395 .ptrace_traceme = selinux_ptrace_traceme,
5396 .capget = selinux_capget,
5397 .capset = selinux_capset,
5398 .sysctl = selinux_sysctl,
5399 .capable = selinux_capable,
5400 .quotactl = selinux_quotactl,
5401 .quota_on = selinux_quota_on,
5402 .syslog = selinux_syslog,
5403 .vm_enough_memory = selinux_vm_enough_memory,
5404
5405 .netlink_send = selinux_netlink_send,
5406 .netlink_recv = selinux_netlink_recv,
5407
5408 .bprm_set_creds = selinux_bprm_set_creds,
5409 .bprm_committing_creds = selinux_bprm_committing_creds,
5410 .bprm_committed_creds = selinux_bprm_committed_creds,
5411 .bprm_secureexec = selinux_bprm_secureexec,
5412
5413 .sb_alloc_security = selinux_sb_alloc_security,
5414 .sb_free_security = selinux_sb_free_security,
5415 .sb_copy_data = selinux_sb_copy_data,
5416 .sb_kern_mount = selinux_sb_kern_mount,
5417 .sb_show_options = selinux_sb_show_options,
5418 .sb_statfs = selinux_sb_statfs,
5419 .sb_mount = selinux_mount,
5420 .sb_umount = selinux_umount,
5421 .sb_set_mnt_opts = selinux_set_mnt_opts,
5422 .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts,
5423 .sb_parse_opts_str = selinux_parse_opts_str,
5424
5425
5426 .inode_alloc_security = selinux_inode_alloc_security,
5427 .inode_free_security = selinux_inode_free_security,
5428 .inode_init_security = selinux_inode_init_security,
5429 .inode_create = selinux_inode_create,
5430 .inode_link = selinux_inode_link,
5431 .inode_unlink = selinux_inode_unlink,
5432 .inode_symlink = selinux_inode_symlink,
5433 .inode_mkdir = selinux_inode_mkdir,
5434 .inode_rmdir = selinux_inode_rmdir,
5435 .inode_mknod = selinux_inode_mknod,
5436 .inode_rename = selinux_inode_rename,
5437 .inode_readlink = selinux_inode_readlink,
5438 .inode_follow_link = selinux_inode_follow_link,
5439 .inode_permission = selinux_inode_permission,
5440 .inode_setattr = selinux_inode_setattr,
5441 .inode_getattr = selinux_inode_getattr,
5442 .inode_setxattr = selinux_inode_setxattr,
5443 .inode_post_setxattr = selinux_inode_post_setxattr,
5444 .inode_getxattr = selinux_inode_getxattr,
5445 .inode_listxattr = selinux_inode_listxattr,
5446 .inode_removexattr = selinux_inode_removexattr,
5447 .inode_getsecurity = selinux_inode_getsecurity,
5448 .inode_setsecurity = selinux_inode_setsecurity,
5449 .inode_listsecurity = selinux_inode_listsecurity,
5450 .inode_getsecid = selinux_inode_getsecid,
5451
5452 .file_permission = selinux_file_permission,
5453 .file_alloc_security = selinux_file_alloc_security,
5454 .file_free_security = selinux_file_free_security,
5455 .file_ioctl = selinux_file_ioctl,
5456 .file_mmap = selinux_file_mmap,
5457 .file_mprotect = selinux_file_mprotect,
5458 .file_lock = selinux_file_lock,
5459 .file_fcntl = selinux_file_fcntl,
5460 .file_set_fowner = selinux_file_set_fowner,
5461 .file_send_sigiotask = selinux_file_send_sigiotask,
5462 .file_receive = selinux_file_receive,
5463
5464 .dentry_open = selinux_dentry_open,
5465
5466 .task_create = selinux_task_create,
5467 .cred_alloc_blank = selinux_cred_alloc_blank,
5468 .cred_free = selinux_cred_free,
5469 .cred_prepare = selinux_cred_prepare,
5470 .cred_transfer = selinux_cred_transfer,
5471 .kernel_act_as = selinux_kernel_act_as,
5472 .kernel_create_files_as = selinux_kernel_create_files_as,
5473 .kernel_module_request = selinux_kernel_module_request,
5474 .task_setpgid = selinux_task_setpgid,
5475 .task_getpgid = selinux_task_getpgid,
5476 .task_getsid = selinux_task_getsid,
5477 .task_getsecid = selinux_task_getsecid,
5478 .task_setnice = selinux_task_setnice,
5479 .task_setioprio = selinux_task_setioprio,
5480 .task_getioprio = selinux_task_getioprio,
5481 .task_setrlimit = selinux_task_setrlimit,
5482 .task_setscheduler = selinux_task_setscheduler,
5483 .task_getscheduler = selinux_task_getscheduler,
5484 .task_movememory = selinux_task_movememory,
5485 .task_kill = selinux_task_kill,
5486 .task_wait = selinux_task_wait,
5487 .task_to_inode = selinux_task_to_inode,
5488
5489 .ipc_permission = selinux_ipc_permission,
5490 .ipc_getsecid = selinux_ipc_getsecid,
5491
5492 .msg_msg_alloc_security = selinux_msg_msg_alloc_security,
5493 .msg_msg_free_security = selinux_msg_msg_free_security,
5494
5495 .msg_queue_alloc_security = selinux_msg_queue_alloc_security,
5496 .msg_queue_free_security = selinux_msg_queue_free_security,
5497 .msg_queue_associate = selinux_msg_queue_associate,
5498 .msg_queue_msgctl = selinux_msg_queue_msgctl,
5499 .msg_queue_msgsnd = selinux_msg_queue_msgsnd,
5500 .msg_queue_msgrcv = selinux_msg_queue_msgrcv,
5501
5502 .shm_alloc_security = selinux_shm_alloc_security,
5503 .shm_free_security = selinux_shm_free_security,
5504 .shm_associate = selinux_shm_associate,
5505 .shm_shmctl = selinux_shm_shmctl,
5506 .shm_shmat = selinux_shm_shmat,
5507
5508 .sem_alloc_security = selinux_sem_alloc_security,
5509 .sem_free_security = selinux_sem_free_security,
5510 .sem_associate = selinux_sem_associate,
5511 .sem_semctl = selinux_sem_semctl,
5512 .sem_semop = selinux_sem_semop,
5513
5514 .d_instantiate = selinux_d_instantiate,
5515
5516 .getprocattr = selinux_getprocattr,
5517 .setprocattr = selinux_setprocattr,
5518
5519 .secid_to_secctx = selinux_secid_to_secctx,
5520 .secctx_to_secid = selinux_secctx_to_secid,
5521 .release_secctx = selinux_release_secctx,
5522 .inode_notifysecctx = selinux_inode_notifysecctx,
5523 .inode_setsecctx = selinux_inode_setsecctx,
5524 .inode_getsecctx = selinux_inode_getsecctx,
5525
5526 .unix_stream_connect = selinux_socket_unix_stream_connect,
5527 .unix_may_send = selinux_socket_unix_may_send,
5528
5529 .socket_create = selinux_socket_create,
5530 .socket_post_create = selinux_socket_post_create,
5531 .socket_bind = selinux_socket_bind,
5532 .socket_connect = selinux_socket_connect,
5533 .socket_listen = selinux_socket_listen,
5534 .socket_accept = selinux_socket_accept,
5535 .socket_sendmsg = selinux_socket_sendmsg,
5536 .socket_recvmsg = selinux_socket_recvmsg,
5537 .socket_getsockname = selinux_socket_getsockname,
5538 .socket_getpeername = selinux_socket_getpeername,
5539 .socket_getsockopt = selinux_socket_getsockopt,
5540 .socket_setsockopt = selinux_socket_setsockopt,
5541 .socket_shutdown = selinux_socket_shutdown,
5542 .socket_sock_rcv_skb = selinux_socket_sock_rcv_skb,
5543 .socket_getpeersec_stream = selinux_socket_getpeersec_stream,
5544 .socket_getpeersec_dgram = selinux_socket_getpeersec_dgram,
5545 .sk_alloc_security = selinux_sk_alloc_security,
5546 .sk_free_security = selinux_sk_free_security,
5547 .sk_clone_security = selinux_sk_clone_security,
5548 .sk_getsecid = selinux_sk_getsecid,
5549 .sock_graft = selinux_sock_graft,
5550 .inet_conn_request = selinux_inet_conn_request,
5551 .inet_csk_clone = selinux_inet_csk_clone,
5552 .inet_conn_established = selinux_inet_conn_established,
5553 .secmark_relabel_packet = selinux_secmark_relabel_packet,
5554 .secmark_refcount_inc = selinux_secmark_refcount_inc,
5555 .secmark_refcount_dec = selinux_secmark_refcount_dec,
5556 .req_classify_flow = selinux_req_classify_flow,
5557 .tun_dev_create = selinux_tun_dev_create,
5558 .tun_dev_post_create = selinux_tun_dev_post_create,
5559 .tun_dev_attach = selinux_tun_dev_attach,
5560
5561 #ifdef CONFIG_SECURITY_NETWORK_XFRM
5562 .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc,
5563 .xfrm_policy_clone_security = selinux_xfrm_policy_clone,
5564 .xfrm_policy_free_security = selinux_xfrm_policy_free,
5565 .xfrm_policy_delete_security = selinux_xfrm_policy_delete,
5566 .xfrm_state_alloc_security = selinux_xfrm_state_alloc,
5567 .xfrm_state_free_security = selinux_xfrm_state_free,
5568 .xfrm_state_delete_security = selinux_xfrm_state_delete,
5569 .xfrm_policy_lookup = selinux_xfrm_policy_lookup,
5570 .xfrm_state_pol_flow_match = selinux_xfrm_state_pol_flow_match,
5571 .xfrm_decode_session = selinux_xfrm_decode_session,
5572 #endif
5573
5574 #ifdef CONFIG_KEYS
5575 .key_alloc = selinux_key_alloc,
5576 .key_free = selinux_key_free,
5577 .key_permission = selinux_key_permission,
5578 .key_getsecurity = selinux_key_getsecurity,
5579 #endif
5580
5581 #ifdef CONFIG_AUDIT
5582 .audit_rule_init = selinux_audit_rule_init,
5583 .audit_rule_known = selinux_audit_rule_known,
5584 .audit_rule_match = selinux_audit_rule_match,
5585 .audit_rule_free = selinux_audit_rule_free,
5586 #endif
5587 };
5588
5589 static __init int selinux_init(void)
5590 {
5591 if (!security_module_enable(&selinux_ops)) {
5592 selinux_enabled = 0;
5593 return 0;
5594 }
5595
5596 if (!selinux_enabled) {
5597 printk(KERN_INFO "SELinux: Disabled at boot.\n");
5598 return 0;
5599 }
5600
5601 printk(KERN_INFO "SELinux: Initializing.\n");
5602
5603 /* Set the security state for the initial task. */
5604 cred_init_security();
5605
5606 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
5607
5608 sel_inode_cache = kmem_cache_create("selinux_inode_security",
5609 sizeof(struct inode_security_struct),
5610 0, SLAB_PANIC, NULL);
5611 avc_init();
5612
5613 if (register_security(&selinux_ops))
5614 panic("SELinux: Unable to register with kernel.\n");
5615
5616 if (selinux_enforcing)
5617 printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n");
5618 else
5619 printk(KERN_DEBUG "SELinux: Starting in permissive mode\n");
5620
5621 return 0;
5622 }
5623
5624 static void delayed_superblock_init(struct super_block *sb, void *unused)
5625 {
5626 superblock_doinit(sb, NULL);
5627 }
5628
5629 void selinux_complete_init(void)
5630 {
5631 printk(KERN_DEBUG "SELinux: Completing initialization.\n");
5632
5633 /* Set up any superblocks initialized prior to the policy load. */
5634 printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n");
5635 iterate_supers(delayed_superblock_init, NULL);
5636 }
5637
5638 /* SELinux requires early initialization in order to label
5639 all processes and objects when they are created. */
5640 security_initcall(selinux_init);
5641
5642 #if defined(CONFIG_NETFILTER)
5643
5644 static struct nf_hook_ops selinux_ipv4_ops[] = {
5645 {
5646 .hook = selinux_ipv4_postroute,
5647 .owner = THIS_MODULE,
5648 .pf = PF_INET,
5649 .hooknum = NF_INET_POST_ROUTING,
5650 .priority = NF_IP_PRI_SELINUX_LAST,
5651 },
5652 {
5653 .hook = selinux_ipv4_forward,
5654 .owner = THIS_MODULE,
5655 .pf = PF_INET,
5656 .hooknum = NF_INET_FORWARD,
5657 .priority = NF_IP_PRI_SELINUX_FIRST,
5658 },
5659 {
5660 .hook = selinux_ipv4_output,
5661 .owner = THIS_MODULE,
5662 .pf = PF_INET,
5663 .hooknum = NF_INET_LOCAL_OUT,
5664 .priority = NF_IP_PRI_SELINUX_FIRST,
5665 }
5666 };
5667
5668 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5669
5670 static struct nf_hook_ops selinux_ipv6_ops[] = {
5671 {
5672 .hook = selinux_ipv6_postroute,
5673 .owner = THIS_MODULE,
5674 .pf = PF_INET6,
5675 .hooknum = NF_INET_POST_ROUTING,
5676 .priority = NF_IP6_PRI_SELINUX_LAST,
5677 },
5678 {
5679 .hook = selinux_ipv6_forward,
5680 .owner = THIS_MODULE,
5681 .pf = PF_INET6,
5682 .hooknum = NF_INET_FORWARD,
5683 .priority = NF_IP6_PRI_SELINUX_FIRST,
5684 }
5685 };
5686
5687 #endif /* IPV6 */
5688
5689 static int __init selinux_nf_ip_init(void)
5690 {
5691 int err = 0;
5692
5693 if (!selinux_enabled)
5694 goto out;
5695
5696 printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n");
5697
5698 err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5699 if (err)
5700 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
5701
5702 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5703 err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5704 if (err)
5705 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
5706 #endif /* IPV6 */
5707
5708 out:
5709 return err;
5710 }
5711
5712 __initcall(selinux_nf_ip_init);
5713
5714 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5715 static void selinux_nf_ip_exit(void)
5716 {
5717 printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n");
5718
5719 nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5720 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5721 nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5722 #endif /* IPV6 */
5723 }
5724 #endif
5725
5726 #else /* CONFIG_NETFILTER */
5727
5728 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5729 #define selinux_nf_ip_exit()
5730 #endif
5731
5732 #endif /* CONFIG_NETFILTER */
5733
5734 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5735 static int selinux_disabled;
5736
5737 int selinux_disable(void)
5738 {
5739 extern void exit_sel_fs(void);
5740
5741 if (ss_initialized) {
5742 /* Not permitted after initial policy load. */
5743 return -EINVAL;
5744 }
5745
5746 if (selinux_disabled) {
5747 /* Only do this once. */
5748 return -EINVAL;
5749 }
5750
5751 printk(KERN_INFO "SELinux: Disabled at runtime.\n");
5752
5753 selinux_disabled = 1;
5754 selinux_enabled = 0;
5755
5756 reset_security_ops();
5757
5758 /* Try to destroy the avc node cache */
5759 avc_disable();
5760
5761 /* Unregister netfilter hooks. */
5762 selinux_nf_ip_exit();
5763
5764 /* Unregister selinuxfs. */
5765 exit_sel_fs();
5766
5767 return 0;
5768 }
5769 #endif
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