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Merge branch 'devicetree/for-x86' of git://git.secretlab.ca/git/linux-2.6 into x86...
[deliverable/linux.git] / security / selinux / hooks.c
1 /*
2 * NSA Security-Enhanced Linux (SELinux) security module
3 *
4 * This file contains the SELinux hook function implementations.
5 *
6 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
7 * Chris Vance, <cvance@nai.com>
8 * Wayne Salamon, <wsalamon@nai.com>
9 * James Morris <jmorris@redhat.com>
10 *
11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12 * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
13 * Eric Paris <eparis@redhat.com>
14 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
15 * <dgoeddel@trustedcs.com>
16 * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
17 * Paul Moore <paul.moore@hp.com>
18 * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
19 * Yuichi Nakamura <ynakam@hitachisoft.jp>
20 *
21 * This program is free software; you can redistribute it and/or modify
22 * it under the terms of the GNU General Public License version 2,
23 * as published by the Free Software Foundation.
24 */
25
26 #include <linux/init.h>
27 #include <linux/kernel.h>
28 #include <linux/tracehook.h>
29 #include <linux/errno.h>
30 #include <linux/sched.h>
31 #include <linux/security.h>
32 #include <linux/xattr.h>
33 #include <linux/capability.h>
34 #include <linux/unistd.h>
35 #include <linux/mm.h>
36 #include <linux/mman.h>
37 #include <linux/slab.h>
38 #include <linux/pagemap.h>
39 #include <linux/swap.h>
40 #include <linux/spinlock.h>
41 #include <linux/syscalls.h>
42 #include <linux/file.h>
43 #include <linux/fdtable.h>
44 #include <linux/namei.h>
45 #include <linux/mount.h>
46 #include <linux/proc_fs.h>
47 #include <linux/netfilter_ipv4.h>
48 #include <linux/netfilter_ipv6.h>
49 #include <linux/tty.h>
50 #include <net/icmp.h>
51 #include <net/ip.h> /* for local_port_range[] */
52 #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
53 #include <net/net_namespace.h>
54 #include <net/netlabel.h>
55 #include <linux/uaccess.h>
56 #include <asm/ioctls.h>
57 #include <asm/atomic.h>
58 #include <linux/bitops.h>
59 #include <linux/interrupt.h>
60 #include <linux/netdevice.h> /* for network interface checks */
61 #include <linux/netlink.h>
62 #include <linux/tcp.h>
63 #include <linux/udp.h>
64 #include <linux/dccp.h>
65 #include <linux/quota.h>
66 #include <linux/un.h> /* for Unix socket types */
67 #include <net/af_unix.h> /* for Unix socket types */
68 #include <linux/parser.h>
69 #include <linux/nfs_mount.h>
70 #include <net/ipv6.h>
71 #include <linux/hugetlb.h>
72 #include <linux/personality.h>
73 #include <linux/sysctl.h>
74 #include <linux/audit.h>
75 #include <linux/string.h>
76 #include <linux/selinux.h>
77 #include <linux/mutex.h>
78 #include <linux/posix-timers.h>
79 #include <linux/syslog.h>
80
81 #include "avc.h"
82 #include "objsec.h"
83 #include "netif.h"
84 #include "netnode.h"
85 #include "netport.h"
86 #include "xfrm.h"
87 #include "netlabel.h"
88 #include "audit.h"
89
90 #define 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 ((sbsec->flags & SE_SBINITIALIZED) &&
2529 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
2530 newsid = sbsec->mntpoint_sid;
2531 else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
2532 rc = security_transition_sid(sid, dsec->sid,
2533 inode_mode_to_security_class(inode->i_mode),
2534 &newsid);
2535 if (rc) {
2536 printk(KERN_WARNING "%s: "
2537 "security_transition_sid failed, rc=%d (dev=%s "
2538 "ino=%ld)\n",
2539 __func__,
2540 -rc, inode->i_sb->s_id, inode->i_ino);
2541 return rc;
2542 }
2543 }
2544
2545 /* Possibly defer initialization to selinux_complete_init. */
2546 if (sbsec->flags & SE_SBINITIALIZED) {
2547 struct inode_security_struct *isec = inode->i_security;
2548 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2549 isec->sid = newsid;
2550 isec->initialized = 1;
2551 }
2552
2553 if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
2554 return -EOPNOTSUPP;
2555
2556 if (name) {
2557 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
2558 if (!namep)
2559 return -ENOMEM;
2560 *name = namep;
2561 }
2562
2563 if (value && len) {
2564 rc = security_sid_to_context_force(newsid, &context, &clen);
2565 if (rc) {
2566 kfree(namep);
2567 return rc;
2568 }
2569 *value = context;
2570 *len = clen;
2571 }
2572
2573 return 0;
2574 }
2575
2576 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2577 {
2578 return may_create(dir, dentry, SECCLASS_FILE);
2579 }
2580
2581 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2582 {
2583 return may_link(dir, old_dentry, MAY_LINK);
2584 }
2585
2586 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2587 {
2588 return may_link(dir, dentry, MAY_UNLINK);
2589 }
2590
2591 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2592 {
2593 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2594 }
2595
2596 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2597 {
2598 return may_create(dir, dentry, SECCLASS_DIR);
2599 }
2600
2601 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2602 {
2603 return may_link(dir, dentry, MAY_RMDIR);
2604 }
2605
2606 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2607 {
2608 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2609 }
2610
2611 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2612 struct inode *new_inode, struct dentry *new_dentry)
2613 {
2614 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2615 }
2616
2617 static int selinux_inode_readlink(struct dentry *dentry)
2618 {
2619 const struct cred *cred = current_cred();
2620
2621 return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2622 }
2623
2624 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2625 {
2626 const struct cred *cred = current_cred();
2627
2628 return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2629 }
2630
2631 static int selinux_inode_permission(struct inode *inode, int mask)
2632 {
2633 const struct cred *cred = current_cred();
2634 struct common_audit_data ad;
2635 u32 perms;
2636 bool from_access;
2637
2638 from_access = mask & MAY_ACCESS;
2639 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
2640
2641 /* No permission to check. Existence test. */
2642 if (!mask)
2643 return 0;
2644
2645 COMMON_AUDIT_DATA_INIT(&ad, FS);
2646 ad.u.fs.inode = inode;
2647
2648 if (from_access)
2649 ad.selinux_audit_data.auditdeny |= FILE__AUDIT_ACCESS;
2650
2651 perms = file_mask_to_av(inode->i_mode, mask);
2652
2653 return inode_has_perm(cred, inode, perms, &ad);
2654 }
2655
2656 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2657 {
2658 const struct cred *cred = current_cred();
2659 unsigned int ia_valid = iattr->ia_valid;
2660
2661 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2662 if (ia_valid & ATTR_FORCE) {
2663 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2664 ATTR_FORCE);
2665 if (!ia_valid)
2666 return 0;
2667 }
2668
2669 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2670 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2671 return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2672
2673 return dentry_has_perm(cred, NULL, dentry, FILE__WRITE);
2674 }
2675
2676 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2677 {
2678 const struct cred *cred = current_cred();
2679
2680 return dentry_has_perm(cred, mnt, dentry, FILE__GETATTR);
2681 }
2682
2683 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2684 {
2685 const struct cred *cred = current_cred();
2686
2687 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2688 sizeof XATTR_SECURITY_PREFIX - 1)) {
2689 if (!strcmp(name, XATTR_NAME_CAPS)) {
2690 if (!capable(CAP_SETFCAP))
2691 return -EPERM;
2692 } else if (!capable(CAP_SYS_ADMIN)) {
2693 /* A different attribute in the security namespace.
2694 Restrict to administrator. */
2695 return -EPERM;
2696 }
2697 }
2698
2699 /* Not an attribute we recognize, so just check the
2700 ordinary setattr permission. */
2701 return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2702 }
2703
2704 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2705 const void *value, size_t size, int flags)
2706 {
2707 struct inode *inode = dentry->d_inode;
2708 struct inode_security_struct *isec = inode->i_security;
2709 struct superblock_security_struct *sbsec;
2710 struct common_audit_data ad;
2711 u32 newsid, sid = current_sid();
2712 int rc = 0;
2713
2714 if (strcmp(name, XATTR_NAME_SELINUX))
2715 return selinux_inode_setotherxattr(dentry, name);
2716
2717 sbsec = inode->i_sb->s_security;
2718 if (!(sbsec->flags & SE_SBLABELSUPP))
2719 return -EOPNOTSUPP;
2720
2721 if (!is_owner_or_cap(inode))
2722 return -EPERM;
2723
2724 COMMON_AUDIT_DATA_INIT(&ad, FS);
2725 ad.u.fs.path.dentry = dentry;
2726
2727 rc = avc_has_perm(sid, isec->sid, isec->sclass,
2728 FILE__RELABELFROM, &ad);
2729 if (rc)
2730 return rc;
2731
2732 rc = security_context_to_sid(value, size, &newsid);
2733 if (rc == -EINVAL) {
2734 if (!capable(CAP_MAC_ADMIN))
2735 return rc;
2736 rc = security_context_to_sid_force(value, size, &newsid);
2737 }
2738 if (rc)
2739 return rc;
2740
2741 rc = avc_has_perm(sid, newsid, isec->sclass,
2742 FILE__RELABELTO, &ad);
2743 if (rc)
2744 return rc;
2745
2746 rc = security_validate_transition(isec->sid, newsid, sid,
2747 isec->sclass);
2748 if (rc)
2749 return rc;
2750
2751 return avc_has_perm(newsid,
2752 sbsec->sid,
2753 SECCLASS_FILESYSTEM,
2754 FILESYSTEM__ASSOCIATE,
2755 &ad);
2756 }
2757
2758 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2759 const void *value, size_t size,
2760 int flags)
2761 {
2762 struct inode *inode = dentry->d_inode;
2763 struct inode_security_struct *isec = inode->i_security;
2764 u32 newsid;
2765 int rc;
2766
2767 if (strcmp(name, XATTR_NAME_SELINUX)) {
2768 /* Not an attribute we recognize, so nothing to do. */
2769 return;
2770 }
2771
2772 rc = security_context_to_sid_force(value, size, &newsid);
2773 if (rc) {
2774 printk(KERN_ERR "SELinux: unable to map context to SID"
2775 "for (%s, %lu), rc=%d\n",
2776 inode->i_sb->s_id, inode->i_ino, -rc);
2777 return;
2778 }
2779
2780 isec->sid = newsid;
2781 return;
2782 }
2783
2784 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
2785 {
2786 const struct cred *cred = current_cred();
2787
2788 return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2789 }
2790
2791 static int selinux_inode_listxattr(struct dentry *dentry)
2792 {
2793 const struct cred *cred = current_cred();
2794
2795 return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2796 }
2797
2798 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
2799 {
2800 if (strcmp(name, XATTR_NAME_SELINUX))
2801 return selinux_inode_setotherxattr(dentry, name);
2802
2803 /* No one is allowed to remove a SELinux security label.
2804 You can change the label, but all data must be labeled. */
2805 return -EACCES;
2806 }
2807
2808 /*
2809 * Copy the inode security context value to the user.
2810 *
2811 * Permission check is handled by selinux_inode_getxattr hook.
2812 */
2813 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
2814 {
2815 u32 size;
2816 int error;
2817 char *context = NULL;
2818 struct inode_security_struct *isec = inode->i_security;
2819
2820 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2821 return -EOPNOTSUPP;
2822
2823 /*
2824 * If the caller has CAP_MAC_ADMIN, then get the raw context
2825 * value even if it is not defined by current policy; otherwise,
2826 * use the in-core value under current policy.
2827 * Use the non-auditing forms of the permission checks since
2828 * getxattr may be called by unprivileged processes commonly
2829 * and lack of permission just means that we fall back to the
2830 * in-core context value, not a denial.
2831 */
2832 error = selinux_capable(current, current_cred(), CAP_MAC_ADMIN,
2833 SECURITY_CAP_NOAUDIT);
2834 if (!error)
2835 error = security_sid_to_context_force(isec->sid, &context,
2836 &size);
2837 else
2838 error = security_sid_to_context(isec->sid, &context, &size);
2839 if (error)
2840 return error;
2841 error = size;
2842 if (alloc) {
2843 *buffer = context;
2844 goto out_nofree;
2845 }
2846 kfree(context);
2847 out_nofree:
2848 return error;
2849 }
2850
2851 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2852 const void *value, size_t size, int flags)
2853 {
2854 struct inode_security_struct *isec = inode->i_security;
2855 u32 newsid;
2856 int rc;
2857
2858 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2859 return -EOPNOTSUPP;
2860
2861 if (!value || !size)
2862 return -EACCES;
2863
2864 rc = security_context_to_sid((void *)value, size, &newsid);
2865 if (rc)
2866 return rc;
2867
2868 isec->sid = newsid;
2869 isec->initialized = 1;
2870 return 0;
2871 }
2872
2873 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2874 {
2875 const int len = sizeof(XATTR_NAME_SELINUX);
2876 if (buffer && len <= buffer_size)
2877 memcpy(buffer, XATTR_NAME_SELINUX, len);
2878 return len;
2879 }
2880
2881 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2882 {
2883 struct inode_security_struct *isec = inode->i_security;
2884 *secid = isec->sid;
2885 }
2886
2887 /* file security operations */
2888
2889 static int selinux_revalidate_file_permission(struct file *file, int mask)
2890 {
2891 const struct cred *cred = current_cred();
2892 struct inode *inode = file->f_path.dentry->d_inode;
2893
2894 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2895 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2896 mask |= MAY_APPEND;
2897
2898 return file_has_perm(cred, file,
2899 file_mask_to_av(inode->i_mode, mask));
2900 }
2901
2902 static int selinux_file_permission(struct file *file, int mask)
2903 {
2904 struct inode *inode = file->f_path.dentry->d_inode;
2905 struct file_security_struct *fsec = file->f_security;
2906 struct inode_security_struct *isec = inode->i_security;
2907 u32 sid = current_sid();
2908
2909 if (!mask)
2910 /* No permission to check. Existence test. */
2911 return 0;
2912
2913 if (sid == fsec->sid && fsec->isid == isec->sid &&
2914 fsec->pseqno == avc_policy_seqno())
2915 /* No change since dentry_open check. */
2916 return 0;
2917
2918 return selinux_revalidate_file_permission(file, mask);
2919 }
2920
2921 static int selinux_file_alloc_security(struct file *file)
2922 {
2923 return file_alloc_security(file);
2924 }
2925
2926 static void selinux_file_free_security(struct file *file)
2927 {
2928 file_free_security(file);
2929 }
2930
2931 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2932 unsigned long arg)
2933 {
2934 const struct cred *cred = current_cred();
2935 u32 av = 0;
2936
2937 if (_IOC_DIR(cmd) & _IOC_WRITE)
2938 av |= FILE__WRITE;
2939 if (_IOC_DIR(cmd) & _IOC_READ)
2940 av |= FILE__READ;
2941 if (!av)
2942 av = FILE__IOCTL;
2943
2944 return file_has_perm(cred, file, av);
2945 }
2946
2947 static int default_noexec;
2948
2949 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2950 {
2951 const struct cred *cred = current_cred();
2952 int rc = 0;
2953
2954 if (default_noexec &&
2955 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2956 /*
2957 * We are making executable an anonymous mapping or a
2958 * private file mapping that will also be writable.
2959 * This has an additional check.
2960 */
2961 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
2962 if (rc)
2963 goto error;
2964 }
2965
2966 if (file) {
2967 /* read access is always possible with a mapping */
2968 u32 av = FILE__READ;
2969
2970 /* write access only matters if the mapping is shared */
2971 if (shared && (prot & PROT_WRITE))
2972 av |= FILE__WRITE;
2973
2974 if (prot & PROT_EXEC)
2975 av |= FILE__EXECUTE;
2976
2977 return file_has_perm(cred, file, av);
2978 }
2979
2980 error:
2981 return rc;
2982 }
2983
2984 static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2985 unsigned long prot, unsigned long flags,
2986 unsigned long addr, unsigned long addr_only)
2987 {
2988 int rc = 0;
2989 u32 sid = current_sid();
2990
2991 /*
2992 * notice that we are intentionally putting the SELinux check before
2993 * the secondary cap_file_mmap check. This is such a likely attempt
2994 * at bad behaviour/exploit that we always want to get the AVC, even
2995 * if DAC would have also denied the operation.
2996 */
2997 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
2998 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
2999 MEMPROTECT__MMAP_ZERO, NULL);
3000 if (rc)
3001 return rc;
3002 }
3003
3004 /* do DAC check on address space usage */
3005 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
3006 if (rc || addr_only)
3007 return rc;
3008
3009 if (selinux_checkreqprot)
3010 prot = reqprot;
3011
3012 return file_map_prot_check(file, prot,
3013 (flags & MAP_TYPE) == MAP_SHARED);
3014 }
3015
3016 static int selinux_file_mprotect(struct vm_area_struct *vma,
3017 unsigned long reqprot,
3018 unsigned long prot)
3019 {
3020 const struct cred *cred = current_cred();
3021
3022 if (selinux_checkreqprot)
3023 prot = reqprot;
3024
3025 if (default_noexec &&
3026 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3027 int rc = 0;
3028 if (vma->vm_start >= vma->vm_mm->start_brk &&
3029 vma->vm_end <= vma->vm_mm->brk) {
3030 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3031 } else if (!vma->vm_file &&
3032 vma->vm_start <= vma->vm_mm->start_stack &&
3033 vma->vm_end >= vma->vm_mm->start_stack) {
3034 rc = current_has_perm(current, PROCESS__EXECSTACK);
3035 } else if (vma->vm_file && vma->anon_vma) {
3036 /*
3037 * We are making executable a file mapping that has
3038 * had some COW done. Since pages might have been
3039 * written, check ability to execute the possibly
3040 * modified content. This typically should only
3041 * occur for text relocations.
3042 */
3043 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3044 }
3045 if (rc)
3046 return rc;
3047 }
3048
3049 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3050 }
3051
3052 static int selinux_file_lock(struct file *file, unsigned int cmd)
3053 {
3054 const struct cred *cred = current_cred();
3055
3056 return file_has_perm(cred, file, FILE__LOCK);
3057 }
3058
3059 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3060 unsigned long arg)
3061 {
3062 const struct cred *cred = current_cred();
3063 int err = 0;
3064
3065 switch (cmd) {
3066 case F_SETFL:
3067 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3068 err = -EINVAL;
3069 break;
3070 }
3071
3072 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3073 err = file_has_perm(cred, file, FILE__WRITE);
3074 break;
3075 }
3076 /* fall through */
3077 case F_SETOWN:
3078 case F_SETSIG:
3079 case F_GETFL:
3080 case F_GETOWN:
3081 case F_GETSIG:
3082 /* Just check FD__USE permission */
3083 err = file_has_perm(cred, file, 0);
3084 break;
3085 case F_GETLK:
3086 case F_SETLK:
3087 case F_SETLKW:
3088 #if BITS_PER_LONG == 32
3089 case F_GETLK64:
3090 case F_SETLK64:
3091 case F_SETLKW64:
3092 #endif
3093 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3094 err = -EINVAL;
3095 break;
3096 }
3097 err = file_has_perm(cred, file, FILE__LOCK);
3098 break;
3099 }
3100
3101 return err;
3102 }
3103
3104 static int selinux_file_set_fowner(struct file *file)
3105 {
3106 struct file_security_struct *fsec;
3107
3108 fsec = file->f_security;
3109 fsec->fown_sid = current_sid();
3110
3111 return 0;
3112 }
3113
3114 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3115 struct fown_struct *fown, int signum)
3116 {
3117 struct file *file;
3118 u32 sid = task_sid(tsk);
3119 u32 perm;
3120 struct file_security_struct *fsec;
3121
3122 /* struct fown_struct is never outside the context of a struct file */
3123 file = container_of(fown, struct file, f_owner);
3124
3125 fsec = file->f_security;
3126
3127 if (!signum)
3128 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3129 else
3130 perm = signal_to_av(signum);
3131
3132 return avc_has_perm(fsec->fown_sid, sid,
3133 SECCLASS_PROCESS, perm, NULL);
3134 }
3135
3136 static int selinux_file_receive(struct file *file)
3137 {
3138 const struct cred *cred = current_cred();
3139
3140 return file_has_perm(cred, file, file_to_av(file));
3141 }
3142
3143 static int selinux_dentry_open(struct file *file, const struct cred *cred)
3144 {
3145 struct file_security_struct *fsec;
3146 struct inode *inode;
3147 struct inode_security_struct *isec;
3148
3149 inode = file->f_path.dentry->d_inode;
3150 fsec = file->f_security;
3151 isec = inode->i_security;
3152 /*
3153 * Save inode label and policy sequence number
3154 * at open-time so that selinux_file_permission
3155 * can determine whether revalidation is necessary.
3156 * Task label is already saved in the file security
3157 * struct as its SID.
3158 */
3159 fsec->isid = isec->sid;
3160 fsec->pseqno = avc_policy_seqno();
3161 /*
3162 * Since the inode label or policy seqno may have changed
3163 * between the selinux_inode_permission check and the saving
3164 * of state above, recheck that access is still permitted.
3165 * Otherwise, access might never be revalidated against the
3166 * new inode label or new policy.
3167 * This check is not redundant - do not remove.
3168 */
3169 return inode_has_perm(cred, inode, open_file_to_av(file), NULL);
3170 }
3171
3172 /* task security operations */
3173
3174 static int selinux_task_create(unsigned long clone_flags)
3175 {
3176 return current_has_perm(current, PROCESS__FORK);
3177 }
3178
3179 /*
3180 * allocate the SELinux part of blank credentials
3181 */
3182 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3183 {
3184 struct task_security_struct *tsec;
3185
3186 tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3187 if (!tsec)
3188 return -ENOMEM;
3189
3190 cred->security = tsec;
3191 return 0;
3192 }
3193
3194 /*
3195 * detach and free the LSM part of a set of credentials
3196 */
3197 static void selinux_cred_free(struct cred *cred)
3198 {
3199 struct task_security_struct *tsec = cred->security;
3200
3201 BUG_ON((unsigned long) cred->security < PAGE_SIZE);
3202 cred->security = (void *) 0x7UL;
3203 kfree(tsec);
3204 }
3205
3206 /*
3207 * prepare a new set of credentials for modification
3208 */
3209 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3210 gfp_t gfp)
3211 {
3212 const struct task_security_struct *old_tsec;
3213 struct task_security_struct *tsec;
3214
3215 old_tsec = old->security;
3216
3217 tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3218 if (!tsec)
3219 return -ENOMEM;
3220
3221 new->security = tsec;
3222 return 0;
3223 }
3224
3225 /*
3226 * transfer the SELinux data to a blank set of creds
3227 */
3228 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3229 {
3230 const struct task_security_struct *old_tsec = old->security;
3231 struct task_security_struct *tsec = new->security;
3232
3233 *tsec = *old_tsec;
3234 }
3235
3236 /*
3237 * set the security data for a kernel service
3238 * - all the creation contexts are set to unlabelled
3239 */
3240 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3241 {
3242 struct task_security_struct *tsec = new->security;
3243 u32 sid = current_sid();
3244 int ret;
3245
3246 ret = avc_has_perm(sid, secid,
3247 SECCLASS_KERNEL_SERVICE,
3248 KERNEL_SERVICE__USE_AS_OVERRIDE,
3249 NULL);
3250 if (ret == 0) {
3251 tsec->sid = secid;
3252 tsec->create_sid = 0;
3253 tsec->keycreate_sid = 0;
3254 tsec->sockcreate_sid = 0;
3255 }
3256 return ret;
3257 }
3258
3259 /*
3260 * set the file creation context in a security record to the same as the
3261 * objective context of the specified inode
3262 */
3263 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3264 {
3265 struct inode_security_struct *isec = inode->i_security;
3266 struct task_security_struct *tsec = new->security;
3267 u32 sid = current_sid();
3268 int ret;
3269
3270 ret = avc_has_perm(sid, isec->sid,
3271 SECCLASS_KERNEL_SERVICE,
3272 KERNEL_SERVICE__CREATE_FILES_AS,
3273 NULL);
3274
3275 if (ret == 0)
3276 tsec->create_sid = isec->sid;
3277 return ret;
3278 }
3279
3280 static int selinux_kernel_module_request(char *kmod_name)
3281 {
3282 u32 sid;
3283 struct common_audit_data ad;
3284
3285 sid = task_sid(current);
3286
3287 COMMON_AUDIT_DATA_INIT(&ad, KMOD);
3288 ad.u.kmod_name = kmod_name;
3289
3290 return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
3291 SYSTEM__MODULE_REQUEST, &ad);
3292 }
3293
3294 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3295 {
3296 return current_has_perm(p, PROCESS__SETPGID);
3297 }
3298
3299 static int selinux_task_getpgid(struct task_struct *p)
3300 {
3301 return current_has_perm(p, PROCESS__GETPGID);
3302 }
3303
3304 static int selinux_task_getsid(struct task_struct *p)
3305 {
3306 return current_has_perm(p, PROCESS__GETSESSION);
3307 }
3308
3309 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3310 {
3311 *secid = task_sid(p);
3312 }
3313
3314 static int selinux_task_setnice(struct task_struct *p, int nice)
3315 {
3316 int rc;
3317
3318 rc = cap_task_setnice(p, nice);
3319 if (rc)
3320 return rc;
3321
3322 return current_has_perm(p, PROCESS__SETSCHED);
3323 }
3324
3325 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3326 {
3327 int rc;
3328
3329 rc = cap_task_setioprio(p, ioprio);
3330 if (rc)
3331 return rc;
3332
3333 return current_has_perm(p, PROCESS__SETSCHED);
3334 }
3335
3336 static int selinux_task_getioprio(struct task_struct *p)
3337 {
3338 return current_has_perm(p, PROCESS__GETSCHED);
3339 }
3340
3341 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
3342 struct rlimit *new_rlim)
3343 {
3344 struct rlimit *old_rlim = p->signal->rlim + resource;
3345
3346 /* Control the ability to change the hard limit (whether
3347 lowering or raising it), so that the hard limit can
3348 later be used as a safe reset point for the soft limit
3349 upon context transitions. See selinux_bprm_committing_creds. */
3350 if (old_rlim->rlim_max != new_rlim->rlim_max)
3351 return current_has_perm(p, PROCESS__SETRLIMIT);
3352
3353 return 0;
3354 }
3355
3356 static int selinux_task_setscheduler(struct task_struct *p)
3357 {
3358 int rc;
3359
3360 rc = cap_task_setscheduler(p);
3361 if (rc)
3362 return rc;
3363
3364 return current_has_perm(p, PROCESS__SETSCHED);
3365 }
3366
3367 static int selinux_task_getscheduler(struct task_struct *p)
3368 {
3369 return current_has_perm(p, PROCESS__GETSCHED);
3370 }
3371
3372 static int selinux_task_movememory(struct task_struct *p)
3373 {
3374 return current_has_perm(p, PROCESS__SETSCHED);
3375 }
3376
3377 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3378 int sig, u32 secid)
3379 {
3380 u32 perm;
3381 int rc;
3382
3383 if (!sig)
3384 perm = PROCESS__SIGNULL; /* null signal; existence test */
3385 else
3386 perm = signal_to_av(sig);
3387 if (secid)
3388 rc = avc_has_perm(secid, task_sid(p),
3389 SECCLASS_PROCESS, perm, NULL);
3390 else
3391 rc = current_has_perm(p, perm);
3392 return rc;
3393 }
3394
3395 static int selinux_task_wait(struct task_struct *p)
3396 {
3397 return task_has_perm(p, current, PROCESS__SIGCHLD);
3398 }
3399
3400 static void selinux_task_to_inode(struct task_struct *p,
3401 struct inode *inode)
3402 {
3403 struct inode_security_struct *isec = inode->i_security;
3404 u32 sid = task_sid(p);
3405
3406 isec->sid = sid;
3407 isec->initialized = 1;
3408 }
3409
3410 /* Returns error only if unable to parse addresses */
3411 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3412 struct common_audit_data *ad, u8 *proto)
3413 {
3414 int offset, ihlen, ret = -EINVAL;
3415 struct iphdr _iph, *ih;
3416
3417 offset = skb_network_offset(skb);
3418 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3419 if (ih == NULL)
3420 goto out;
3421
3422 ihlen = ih->ihl * 4;
3423 if (ihlen < sizeof(_iph))
3424 goto out;
3425
3426 ad->u.net.v4info.saddr = ih->saddr;
3427 ad->u.net.v4info.daddr = ih->daddr;
3428 ret = 0;
3429
3430 if (proto)
3431 *proto = ih->protocol;
3432
3433 switch (ih->protocol) {
3434 case IPPROTO_TCP: {
3435 struct tcphdr _tcph, *th;
3436
3437 if (ntohs(ih->frag_off) & IP_OFFSET)
3438 break;
3439
3440 offset += ihlen;
3441 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3442 if (th == NULL)
3443 break;
3444
3445 ad->u.net.sport = th->source;
3446 ad->u.net.dport = th->dest;
3447 break;
3448 }
3449
3450 case IPPROTO_UDP: {
3451 struct udphdr _udph, *uh;
3452
3453 if (ntohs(ih->frag_off) & IP_OFFSET)
3454 break;
3455
3456 offset += ihlen;
3457 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3458 if (uh == NULL)
3459 break;
3460
3461 ad->u.net.sport = uh->source;
3462 ad->u.net.dport = uh->dest;
3463 break;
3464 }
3465
3466 case IPPROTO_DCCP: {
3467 struct dccp_hdr _dccph, *dh;
3468
3469 if (ntohs(ih->frag_off) & IP_OFFSET)
3470 break;
3471
3472 offset += ihlen;
3473 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3474 if (dh == NULL)
3475 break;
3476
3477 ad->u.net.sport = dh->dccph_sport;
3478 ad->u.net.dport = dh->dccph_dport;
3479 break;
3480 }
3481
3482 default:
3483 break;
3484 }
3485 out:
3486 return ret;
3487 }
3488
3489 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3490
3491 /* Returns error only if unable to parse addresses */
3492 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3493 struct common_audit_data *ad, u8 *proto)
3494 {
3495 u8 nexthdr;
3496 int ret = -EINVAL, offset;
3497 struct ipv6hdr _ipv6h, *ip6;
3498
3499 offset = skb_network_offset(skb);
3500 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3501 if (ip6 == NULL)
3502 goto out;
3503
3504 ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr);
3505 ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr);
3506 ret = 0;
3507
3508 nexthdr = ip6->nexthdr;
3509 offset += sizeof(_ipv6h);
3510 offset = ipv6_skip_exthdr(skb, offset, &nexthdr);
3511 if (offset < 0)
3512 goto out;
3513
3514 if (proto)
3515 *proto = nexthdr;
3516
3517 switch (nexthdr) {
3518 case IPPROTO_TCP: {
3519 struct tcphdr _tcph, *th;
3520
3521 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3522 if (th == NULL)
3523 break;
3524
3525 ad->u.net.sport = th->source;
3526 ad->u.net.dport = th->dest;
3527 break;
3528 }
3529
3530 case IPPROTO_UDP: {
3531 struct udphdr _udph, *uh;
3532
3533 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3534 if (uh == NULL)
3535 break;
3536
3537 ad->u.net.sport = uh->source;
3538 ad->u.net.dport = uh->dest;
3539 break;
3540 }
3541
3542 case IPPROTO_DCCP: {
3543 struct dccp_hdr _dccph, *dh;
3544
3545 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3546 if (dh == NULL)
3547 break;
3548
3549 ad->u.net.sport = dh->dccph_sport;
3550 ad->u.net.dport = dh->dccph_dport;
3551 break;
3552 }
3553
3554 /* includes fragments */
3555 default:
3556 break;
3557 }
3558 out:
3559 return ret;
3560 }
3561
3562 #endif /* IPV6 */
3563
3564 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3565 char **_addrp, int src, u8 *proto)
3566 {
3567 char *addrp;
3568 int ret;
3569
3570 switch (ad->u.net.family) {
3571 case PF_INET:
3572 ret = selinux_parse_skb_ipv4(skb, ad, proto);
3573 if (ret)
3574 goto parse_error;
3575 addrp = (char *)(src ? &ad->u.net.v4info.saddr :
3576 &ad->u.net.v4info.daddr);
3577 goto okay;
3578
3579 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3580 case PF_INET6:
3581 ret = selinux_parse_skb_ipv6(skb, ad, proto);
3582 if (ret)
3583 goto parse_error;
3584 addrp = (char *)(src ? &ad->u.net.v6info.saddr :
3585 &ad->u.net.v6info.daddr);
3586 goto okay;
3587 #endif /* IPV6 */
3588 default:
3589 addrp = NULL;
3590 goto okay;
3591 }
3592
3593 parse_error:
3594 printk(KERN_WARNING
3595 "SELinux: failure in selinux_parse_skb(),"
3596 " unable to parse packet\n");
3597 return ret;
3598
3599 okay:
3600 if (_addrp)
3601 *_addrp = addrp;
3602 return 0;
3603 }
3604
3605 /**
3606 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3607 * @skb: the packet
3608 * @family: protocol family
3609 * @sid: the packet's peer label SID
3610 *
3611 * Description:
3612 * Check the various different forms of network peer labeling and determine
3613 * the peer label/SID for the packet; most of the magic actually occurs in
3614 * the security server function security_net_peersid_cmp(). The function
3615 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
3616 * or -EACCES if @sid is invalid due to inconsistencies with the different
3617 * peer labels.
3618 *
3619 */
3620 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3621 {
3622 int err;
3623 u32 xfrm_sid;
3624 u32 nlbl_sid;
3625 u32 nlbl_type;
3626
3627 selinux_skb_xfrm_sid(skb, &xfrm_sid);
3628 selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3629
3630 err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
3631 if (unlikely(err)) {
3632 printk(KERN_WARNING
3633 "SELinux: failure in selinux_skb_peerlbl_sid(),"
3634 " unable to determine packet's peer label\n");
3635 return -EACCES;
3636 }
3637
3638 return 0;
3639 }
3640
3641 /* socket security operations */
3642
3643 static u32 socket_sockcreate_sid(const struct task_security_struct *tsec)
3644 {
3645 return tsec->sockcreate_sid ? : tsec->sid;
3646 }
3647
3648 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
3649 {
3650 struct sk_security_struct *sksec = sk->sk_security;
3651 struct common_audit_data ad;
3652 u32 tsid = task_sid(task);
3653
3654 if (sksec->sid == SECINITSID_KERNEL)
3655 return 0;
3656
3657 COMMON_AUDIT_DATA_INIT(&ad, NET);
3658 ad.u.net.sk = sk;
3659
3660 return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
3661 }
3662
3663 static int selinux_socket_create(int family, int type,
3664 int protocol, int kern)
3665 {
3666 const struct task_security_struct *tsec = current_security();
3667 u32 newsid;
3668 u16 secclass;
3669
3670 if (kern)
3671 return 0;
3672
3673 newsid = socket_sockcreate_sid(tsec);
3674 secclass = socket_type_to_security_class(family, type, protocol);
3675 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
3676 }
3677
3678 static int selinux_socket_post_create(struct socket *sock, int family,
3679 int type, int protocol, int kern)
3680 {
3681 const struct task_security_struct *tsec = current_security();
3682 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
3683 struct sk_security_struct *sksec;
3684 int err = 0;
3685
3686 if (kern)
3687 isec->sid = SECINITSID_KERNEL;
3688 else
3689 isec->sid = socket_sockcreate_sid(tsec);
3690
3691 isec->sclass = socket_type_to_security_class(family, type, protocol);
3692 isec->initialized = 1;
3693
3694 if (sock->sk) {
3695 sksec = sock->sk->sk_security;
3696 sksec->sid = isec->sid;
3697 sksec->sclass = isec->sclass;
3698 err = selinux_netlbl_socket_post_create(sock->sk, family);
3699 }
3700
3701 return err;
3702 }
3703
3704 /* Range of port numbers used to automatically bind.
3705 Need to determine whether we should perform a name_bind
3706 permission check between the socket and the port number. */
3707
3708 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
3709 {
3710 struct sock *sk = sock->sk;
3711 u16 family;
3712 int err;
3713
3714 err = sock_has_perm(current, sk, SOCKET__BIND);
3715 if (err)
3716 goto out;
3717
3718 /*
3719 * If PF_INET or PF_INET6, check name_bind permission for the port.
3720 * Multiple address binding for SCTP is not supported yet: we just
3721 * check the first address now.
3722 */
3723 family = sk->sk_family;
3724 if (family == PF_INET || family == PF_INET6) {
3725 char *addrp;
3726 struct sk_security_struct *sksec = sk->sk_security;
3727 struct common_audit_data ad;
3728 struct sockaddr_in *addr4 = NULL;
3729 struct sockaddr_in6 *addr6 = NULL;
3730 unsigned short snum;
3731 u32 sid, node_perm;
3732
3733 if (family == PF_INET) {
3734 addr4 = (struct sockaddr_in *)address;
3735 snum = ntohs(addr4->sin_port);
3736 addrp = (char *)&addr4->sin_addr.s_addr;
3737 } else {
3738 addr6 = (struct sockaddr_in6 *)address;
3739 snum = ntohs(addr6->sin6_port);
3740 addrp = (char *)&addr6->sin6_addr.s6_addr;
3741 }
3742
3743 if (snum) {
3744 int low, high;
3745
3746 inet_get_local_port_range(&low, &high);
3747
3748 if (snum < max(PROT_SOCK, low) || snum > high) {
3749 err = sel_netport_sid(sk->sk_protocol,
3750 snum, &sid);
3751 if (err)
3752 goto out;
3753 COMMON_AUDIT_DATA_INIT(&ad, NET);
3754 ad.u.net.sport = htons(snum);
3755 ad.u.net.family = family;
3756 err = avc_has_perm(sksec->sid, sid,
3757 sksec->sclass,
3758 SOCKET__NAME_BIND, &ad);
3759 if (err)
3760 goto out;
3761 }
3762 }
3763
3764 switch (sksec->sclass) {
3765 case SECCLASS_TCP_SOCKET:
3766 node_perm = TCP_SOCKET__NODE_BIND;
3767 break;
3768
3769 case SECCLASS_UDP_SOCKET:
3770 node_perm = UDP_SOCKET__NODE_BIND;
3771 break;
3772
3773 case SECCLASS_DCCP_SOCKET:
3774 node_perm = DCCP_SOCKET__NODE_BIND;
3775 break;
3776
3777 default:
3778 node_perm = RAWIP_SOCKET__NODE_BIND;
3779 break;
3780 }
3781
3782 err = sel_netnode_sid(addrp, family, &sid);
3783 if (err)
3784 goto out;
3785
3786 COMMON_AUDIT_DATA_INIT(&ad, NET);
3787 ad.u.net.sport = htons(snum);
3788 ad.u.net.family = family;
3789
3790 if (family == PF_INET)
3791 ad.u.net.v4info.saddr = addr4->sin_addr.s_addr;
3792 else
3793 ipv6_addr_copy(&ad.u.net.v6info.saddr, &addr6->sin6_addr);
3794
3795 err = avc_has_perm(sksec->sid, sid,
3796 sksec->sclass, node_perm, &ad);
3797 if (err)
3798 goto out;
3799 }
3800 out:
3801 return err;
3802 }
3803
3804 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
3805 {
3806 struct sock *sk = sock->sk;
3807 struct sk_security_struct *sksec = sk->sk_security;
3808 int err;
3809
3810 err = sock_has_perm(current, sk, SOCKET__CONNECT);
3811 if (err)
3812 return err;
3813
3814 /*
3815 * If a TCP or DCCP socket, check name_connect permission for the port.
3816 */
3817 if (sksec->sclass == SECCLASS_TCP_SOCKET ||
3818 sksec->sclass == SECCLASS_DCCP_SOCKET) {
3819 struct common_audit_data ad;
3820 struct sockaddr_in *addr4 = NULL;
3821 struct sockaddr_in6 *addr6 = NULL;
3822 unsigned short snum;
3823 u32 sid, perm;
3824
3825 if (sk->sk_family == PF_INET) {
3826 addr4 = (struct sockaddr_in *)address;
3827 if (addrlen < sizeof(struct sockaddr_in))
3828 return -EINVAL;
3829 snum = ntohs(addr4->sin_port);
3830 } else {
3831 addr6 = (struct sockaddr_in6 *)address;
3832 if (addrlen < SIN6_LEN_RFC2133)
3833 return -EINVAL;
3834 snum = ntohs(addr6->sin6_port);
3835 }
3836
3837 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
3838 if (err)
3839 goto out;
3840
3841 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
3842 TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
3843
3844 COMMON_AUDIT_DATA_INIT(&ad, NET);
3845 ad.u.net.dport = htons(snum);
3846 ad.u.net.family = sk->sk_family;
3847 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
3848 if (err)
3849 goto out;
3850 }
3851
3852 err = selinux_netlbl_socket_connect(sk, address);
3853
3854 out:
3855 return err;
3856 }
3857
3858 static int selinux_socket_listen(struct socket *sock, int backlog)
3859 {
3860 return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
3861 }
3862
3863 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
3864 {
3865 int err;
3866 struct inode_security_struct *isec;
3867 struct inode_security_struct *newisec;
3868
3869 err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
3870 if (err)
3871 return err;
3872
3873 newisec = SOCK_INODE(newsock)->i_security;
3874
3875 isec = SOCK_INODE(sock)->i_security;
3876 newisec->sclass = isec->sclass;
3877 newisec->sid = isec->sid;
3878 newisec->initialized = 1;
3879
3880 return 0;
3881 }
3882
3883 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3884 int size)
3885 {
3886 return sock_has_perm(current, sock->sk, SOCKET__WRITE);
3887 }
3888
3889 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
3890 int size, int flags)
3891 {
3892 return sock_has_perm(current, sock->sk, SOCKET__READ);
3893 }
3894
3895 static int selinux_socket_getsockname(struct socket *sock)
3896 {
3897 return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
3898 }
3899
3900 static int selinux_socket_getpeername(struct socket *sock)
3901 {
3902 return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
3903 }
3904
3905 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
3906 {
3907 int err;
3908
3909 err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
3910 if (err)
3911 return err;
3912
3913 return selinux_netlbl_socket_setsockopt(sock, level, optname);
3914 }
3915
3916 static int selinux_socket_getsockopt(struct socket *sock, int level,
3917 int optname)
3918 {
3919 return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
3920 }
3921
3922 static int selinux_socket_shutdown(struct socket *sock, int how)
3923 {
3924 return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
3925 }
3926
3927 static int selinux_socket_unix_stream_connect(struct sock *sock,
3928 struct sock *other,
3929 struct sock *newsk)
3930 {
3931 struct sk_security_struct *sksec_sock = sock->sk_security;
3932 struct sk_security_struct *sksec_other = other->sk_security;
3933 struct sk_security_struct *sksec_new = newsk->sk_security;
3934 struct common_audit_data ad;
3935 int err;
3936
3937 COMMON_AUDIT_DATA_INIT(&ad, NET);
3938 ad.u.net.sk = other;
3939
3940 err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
3941 sksec_other->sclass,
3942 UNIX_STREAM_SOCKET__CONNECTTO, &ad);
3943 if (err)
3944 return err;
3945
3946 /* server child socket */
3947 sksec_new->peer_sid = sksec_sock->sid;
3948 err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
3949 &sksec_new->sid);
3950 if (err)
3951 return err;
3952
3953 /* connecting socket */
3954 sksec_sock->peer_sid = sksec_new->sid;
3955
3956 return 0;
3957 }
3958
3959 static int selinux_socket_unix_may_send(struct socket *sock,
3960 struct socket *other)
3961 {
3962 struct sk_security_struct *ssec = sock->sk->sk_security;
3963 struct sk_security_struct *osec = other->sk->sk_security;
3964 struct common_audit_data ad;
3965
3966 COMMON_AUDIT_DATA_INIT(&ad, NET);
3967 ad.u.net.sk = other->sk;
3968
3969 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
3970 &ad);
3971 }
3972
3973 static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
3974 u32 peer_sid,
3975 struct common_audit_data *ad)
3976 {
3977 int err;
3978 u32 if_sid;
3979 u32 node_sid;
3980
3981 err = sel_netif_sid(ifindex, &if_sid);
3982 if (err)
3983 return err;
3984 err = avc_has_perm(peer_sid, if_sid,
3985 SECCLASS_NETIF, NETIF__INGRESS, ad);
3986 if (err)
3987 return err;
3988
3989 err = sel_netnode_sid(addrp, family, &node_sid);
3990 if (err)
3991 return err;
3992 return avc_has_perm(peer_sid, node_sid,
3993 SECCLASS_NODE, NODE__RECVFROM, ad);
3994 }
3995
3996 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
3997 u16 family)
3998 {
3999 int err = 0;
4000 struct sk_security_struct *sksec = sk->sk_security;
4001 u32 peer_sid;
4002 u32 sk_sid = sksec->sid;
4003 struct common_audit_data ad;
4004 char *addrp;
4005
4006 COMMON_AUDIT_DATA_INIT(&ad, NET);
4007 ad.u.net.netif = skb->skb_iif;
4008 ad.u.net.family = family;
4009 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4010 if (err)
4011 return err;
4012
4013 if (selinux_secmark_enabled()) {
4014 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4015 PACKET__RECV, &ad);
4016 if (err)
4017 return err;
4018 }
4019
4020 if (selinux_policycap_netpeer) {
4021 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4022 if (err)
4023 return err;
4024 err = avc_has_perm(sk_sid, peer_sid,
4025 SECCLASS_PEER, PEER__RECV, &ad);
4026 if (err)
4027 selinux_netlbl_err(skb, err, 0);
4028 } else {
4029 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4030 if (err)
4031 return err;
4032 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4033 }
4034
4035 return err;
4036 }
4037
4038 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4039 {
4040 int err;
4041 struct sk_security_struct *sksec = sk->sk_security;
4042 u16 family = sk->sk_family;
4043 u32 sk_sid = sksec->sid;
4044 struct common_audit_data ad;
4045 char *addrp;
4046 u8 secmark_active;
4047 u8 peerlbl_active;
4048
4049 if (family != PF_INET && family != PF_INET6)
4050 return 0;
4051
4052 /* Handle mapped IPv4 packets arriving via IPv6 sockets */
4053 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4054 family = PF_INET;
4055
4056 /* If any sort of compatibility mode is enabled then handoff processing
4057 * to the selinux_sock_rcv_skb_compat() function to deal with the
4058 * special handling. We do this in an attempt to keep this function
4059 * as fast and as clean as possible. */
4060 if (!selinux_policycap_netpeer)
4061 return selinux_sock_rcv_skb_compat(sk, skb, family);
4062
4063 secmark_active = selinux_secmark_enabled();
4064 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4065 if (!secmark_active && !peerlbl_active)
4066 return 0;
4067
4068 COMMON_AUDIT_DATA_INIT(&ad, NET);
4069 ad.u.net.netif = skb->skb_iif;
4070 ad.u.net.family = family;
4071 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4072 if (err)
4073 return err;
4074
4075 if (peerlbl_active) {
4076 u32 peer_sid;
4077
4078 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4079 if (err)
4080 return err;
4081 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
4082 peer_sid, &ad);
4083 if (err) {
4084 selinux_netlbl_err(skb, err, 0);
4085 return err;
4086 }
4087 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4088 PEER__RECV, &ad);
4089 if (err)
4090 selinux_netlbl_err(skb, err, 0);
4091 }
4092
4093 if (secmark_active) {
4094 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4095 PACKET__RECV, &ad);
4096 if (err)
4097 return err;
4098 }
4099
4100 return err;
4101 }
4102
4103 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4104 int __user *optlen, unsigned len)
4105 {
4106 int err = 0;
4107 char *scontext;
4108 u32 scontext_len;
4109 struct sk_security_struct *sksec = sock->sk->sk_security;
4110 u32 peer_sid = SECSID_NULL;
4111
4112 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4113 sksec->sclass == SECCLASS_TCP_SOCKET)
4114 peer_sid = sksec->peer_sid;
4115 if (peer_sid == SECSID_NULL)
4116 return -ENOPROTOOPT;
4117
4118 err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4119 if (err)
4120 return err;
4121
4122 if (scontext_len > len) {
4123 err = -ERANGE;
4124 goto out_len;
4125 }
4126
4127 if (copy_to_user(optval, scontext, scontext_len))
4128 err = -EFAULT;
4129
4130 out_len:
4131 if (put_user(scontext_len, optlen))
4132 err = -EFAULT;
4133 kfree(scontext);
4134 return err;
4135 }
4136
4137 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4138 {
4139 u32 peer_secid = SECSID_NULL;
4140 u16 family;
4141
4142 if (skb && skb->protocol == htons(ETH_P_IP))
4143 family = PF_INET;
4144 else if (skb && skb->protocol == htons(ETH_P_IPV6))
4145 family = PF_INET6;
4146 else if (sock)
4147 family = sock->sk->sk_family;
4148 else
4149 goto out;
4150
4151 if (sock && family == PF_UNIX)
4152 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4153 else if (skb)
4154 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4155
4156 out:
4157 *secid = peer_secid;
4158 if (peer_secid == SECSID_NULL)
4159 return -EINVAL;
4160 return 0;
4161 }
4162
4163 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4164 {
4165 struct sk_security_struct *sksec;
4166
4167 sksec = kzalloc(sizeof(*sksec), priority);
4168 if (!sksec)
4169 return -ENOMEM;
4170
4171 sksec->peer_sid = SECINITSID_UNLABELED;
4172 sksec->sid = SECINITSID_UNLABELED;
4173 selinux_netlbl_sk_security_reset(sksec);
4174 sk->sk_security = sksec;
4175
4176 return 0;
4177 }
4178
4179 static void selinux_sk_free_security(struct sock *sk)
4180 {
4181 struct sk_security_struct *sksec = sk->sk_security;
4182
4183 sk->sk_security = NULL;
4184 selinux_netlbl_sk_security_free(sksec);
4185 kfree(sksec);
4186 }
4187
4188 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4189 {
4190 struct sk_security_struct *sksec = sk->sk_security;
4191 struct sk_security_struct *newsksec = newsk->sk_security;
4192
4193 newsksec->sid = sksec->sid;
4194 newsksec->peer_sid = sksec->peer_sid;
4195 newsksec->sclass = sksec->sclass;
4196
4197 selinux_netlbl_sk_security_reset(newsksec);
4198 }
4199
4200 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4201 {
4202 if (!sk)
4203 *secid = SECINITSID_ANY_SOCKET;
4204 else {
4205 struct sk_security_struct *sksec = sk->sk_security;
4206
4207 *secid = sksec->sid;
4208 }
4209 }
4210
4211 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4212 {
4213 struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
4214 struct sk_security_struct *sksec = sk->sk_security;
4215
4216 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4217 sk->sk_family == PF_UNIX)
4218 isec->sid = sksec->sid;
4219 sksec->sclass = isec->sclass;
4220 }
4221
4222 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4223 struct request_sock *req)
4224 {
4225 struct sk_security_struct *sksec = sk->sk_security;
4226 int err;
4227 u16 family = sk->sk_family;
4228 u32 newsid;
4229 u32 peersid;
4230
4231 /* handle mapped IPv4 packets arriving via IPv6 sockets */
4232 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4233 family = PF_INET;
4234
4235 err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4236 if (err)
4237 return err;
4238 if (peersid == SECSID_NULL) {
4239 req->secid = sksec->sid;
4240 req->peer_secid = SECSID_NULL;
4241 } else {
4242 err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
4243 if (err)
4244 return err;
4245 req->secid = newsid;
4246 req->peer_secid = peersid;
4247 }
4248
4249 return selinux_netlbl_inet_conn_request(req, family);
4250 }
4251
4252 static void selinux_inet_csk_clone(struct sock *newsk,
4253 const struct request_sock *req)
4254 {
4255 struct sk_security_struct *newsksec = newsk->sk_security;
4256
4257 newsksec->sid = req->secid;
4258 newsksec->peer_sid = req->peer_secid;
4259 /* NOTE: Ideally, we should also get the isec->sid for the
4260 new socket in sync, but we don't have the isec available yet.
4261 So we will wait until sock_graft to do it, by which
4262 time it will have been created and available. */
4263
4264 /* We don't need to take any sort of lock here as we are the only
4265 * thread with access to newsksec */
4266 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4267 }
4268
4269 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4270 {
4271 u16 family = sk->sk_family;
4272 struct sk_security_struct *sksec = sk->sk_security;
4273
4274 /* handle mapped IPv4 packets arriving via IPv6 sockets */
4275 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4276 family = PF_INET;
4277
4278 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4279 }
4280
4281 static int selinux_secmark_relabel_packet(u32 sid)
4282 {
4283 const struct task_security_struct *__tsec;
4284 u32 tsid;
4285
4286 __tsec = current_security();
4287 tsid = __tsec->sid;
4288
4289 return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
4290 }
4291
4292 static void selinux_secmark_refcount_inc(void)
4293 {
4294 atomic_inc(&selinux_secmark_refcount);
4295 }
4296
4297 static void selinux_secmark_refcount_dec(void)
4298 {
4299 atomic_dec(&selinux_secmark_refcount);
4300 }
4301
4302 static void selinux_req_classify_flow(const struct request_sock *req,
4303 struct flowi *fl)
4304 {
4305 fl->secid = req->secid;
4306 }
4307
4308 static int selinux_tun_dev_create(void)
4309 {
4310 u32 sid = current_sid();
4311
4312 /* we aren't taking into account the "sockcreate" SID since the socket
4313 * that is being created here is not a socket in the traditional sense,
4314 * instead it is a private sock, accessible only to the kernel, and
4315 * representing a wide range of network traffic spanning multiple
4316 * connections unlike traditional sockets - check the TUN driver to
4317 * get a better understanding of why this socket is special */
4318
4319 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4320 NULL);
4321 }
4322
4323 static void selinux_tun_dev_post_create(struct sock *sk)
4324 {
4325 struct sk_security_struct *sksec = sk->sk_security;
4326
4327 /* we don't currently perform any NetLabel based labeling here and it
4328 * isn't clear that we would want to do so anyway; while we could apply
4329 * labeling without the support of the TUN user the resulting labeled
4330 * traffic from the other end of the connection would almost certainly
4331 * cause confusion to the TUN user that had no idea network labeling
4332 * protocols were being used */
4333
4334 /* see the comments in selinux_tun_dev_create() about why we don't use
4335 * the sockcreate SID here */
4336
4337 sksec->sid = current_sid();
4338 sksec->sclass = SECCLASS_TUN_SOCKET;
4339 }
4340
4341 static int selinux_tun_dev_attach(struct sock *sk)
4342 {
4343 struct sk_security_struct *sksec = sk->sk_security;
4344 u32 sid = current_sid();
4345 int err;
4346
4347 err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET,
4348 TUN_SOCKET__RELABELFROM, NULL);
4349 if (err)
4350 return err;
4351 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4352 TUN_SOCKET__RELABELTO, NULL);
4353 if (err)
4354 return err;
4355
4356 sksec->sid = sid;
4357
4358 return 0;
4359 }
4360
4361 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4362 {
4363 int err = 0;
4364 u32 perm;
4365 struct nlmsghdr *nlh;
4366 struct sk_security_struct *sksec = sk->sk_security;
4367
4368 if (skb->len < NLMSG_SPACE(0)) {
4369 err = -EINVAL;
4370 goto out;
4371 }
4372 nlh = nlmsg_hdr(skb);
4373
4374 err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
4375 if (err) {
4376 if (err == -EINVAL) {
4377 audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
4378 "SELinux: unrecognized netlink message"
4379 " type=%hu for sclass=%hu\n",
4380 nlh->nlmsg_type, sksec->sclass);
4381 if (!selinux_enforcing || security_get_allow_unknown())
4382 err = 0;
4383 }
4384
4385 /* Ignore */
4386 if (err == -ENOENT)
4387 err = 0;
4388 goto out;
4389 }
4390
4391 err = sock_has_perm(current, sk, perm);
4392 out:
4393 return err;
4394 }
4395
4396 #ifdef CONFIG_NETFILTER
4397
4398 static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
4399 u16 family)
4400 {
4401 int err;
4402 char *addrp;
4403 u32 peer_sid;
4404 struct common_audit_data ad;
4405 u8 secmark_active;
4406 u8 netlbl_active;
4407 u8 peerlbl_active;
4408
4409 if (!selinux_policycap_netpeer)
4410 return NF_ACCEPT;
4411
4412 secmark_active = selinux_secmark_enabled();
4413 netlbl_active = netlbl_enabled();
4414 peerlbl_active = netlbl_active || selinux_xfrm_enabled();
4415 if (!secmark_active && !peerlbl_active)
4416 return NF_ACCEPT;
4417
4418 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
4419 return NF_DROP;
4420
4421 COMMON_AUDIT_DATA_INIT(&ad, NET);
4422 ad.u.net.netif = ifindex;
4423 ad.u.net.family = family;
4424 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
4425 return NF_DROP;
4426
4427 if (peerlbl_active) {
4428 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
4429 peer_sid, &ad);
4430 if (err) {
4431 selinux_netlbl_err(skb, err, 1);
4432 return NF_DROP;
4433 }
4434 }
4435
4436 if (secmark_active)
4437 if (avc_has_perm(peer_sid, skb->secmark,
4438 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
4439 return NF_DROP;
4440
4441 if (netlbl_active)
4442 /* we do this in the FORWARD path and not the POST_ROUTING
4443 * path because we want to make sure we apply the necessary
4444 * labeling before IPsec is applied so we can leverage AH
4445 * protection */
4446 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
4447 return NF_DROP;
4448
4449 return NF_ACCEPT;
4450 }
4451
4452 static unsigned int selinux_ipv4_forward(unsigned int hooknum,
4453 struct sk_buff *skb,
4454 const struct net_device *in,
4455 const struct net_device *out,
4456 int (*okfn)(struct sk_buff *))
4457 {
4458 return selinux_ip_forward(skb, in->ifindex, PF_INET);
4459 }
4460
4461 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4462 static unsigned int selinux_ipv6_forward(unsigned int hooknum,
4463 struct sk_buff *skb,
4464 const struct net_device *in,
4465 const struct net_device *out,
4466 int (*okfn)(struct sk_buff *))
4467 {
4468 return selinux_ip_forward(skb, in->ifindex, PF_INET6);
4469 }
4470 #endif /* IPV6 */
4471
4472 static unsigned int selinux_ip_output(struct sk_buff *skb,
4473 u16 family)
4474 {
4475 u32 sid;
4476
4477 if (!netlbl_enabled())
4478 return NF_ACCEPT;
4479
4480 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
4481 * because we want to make sure we apply the necessary labeling
4482 * before IPsec is applied so we can leverage AH protection */
4483 if (skb->sk) {
4484 struct sk_security_struct *sksec = skb->sk->sk_security;
4485 sid = sksec->sid;
4486 } else
4487 sid = SECINITSID_KERNEL;
4488 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
4489 return NF_DROP;
4490
4491 return NF_ACCEPT;
4492 }
4493
4494 static unsigned int selinux_ipv4_output(unsigned int hooknum,
4495 struct sk_buff *skb,
4496 const struct net_device *in,
4497 const struct net_device *out,
4498 int (*okfn)(struct sk_buff *))
4499 {
4500 return selinux_ip_output(skb, PF_INET);
4501 }
4502
4503 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
4504 int ifindex,
4505 u16 family)
4506 {
4507 struct sock *sk = skb->sk;
4508 struct sk_security_struct *sksec;
4509 struct common_audit_data ad;
4510 char *addrp;
4511 u8 proto;
4512
4513 if (sk == NULL)
4514 return NF_ACCEPT;
4515 sksec = sk->sk_security;
4516
4517 COMMON_AUDIT_DATA_INIT(&ad, NET);
4518 ad.u.net.netif = ifindex;
4519 ad.u.net.family = family;
4520 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
4521 return NF_DROP;
4522
4523 if (selinux_secmark_enabled())
4524 if (avc_has_perm(sksec->sid, skb->secmark,
4525 SECCLASS_PACKET, PACKET__SEND, &ad))
4526 return NF_DROP_ERR(-ECONNREFUSED);
4527
4528 if (selinux_policycap_netpeer)
4529 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
4530 return NF_DROP_ERR(-ECONNREFUSED);
4531
4532 return NF_ACCEPT;
4533 }
4534
4535 static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
4536 u16 family)
4537 {
4538 u32 secmark_perm;
4539 u32 peer_sid;
4540 struct sock *sk;
4541 struct common_audit_data ad;
4542 char *addrp;
4543 u8 secmark_active;
4544 u8 peerlbl_active;
4545
4546 /* If any sort of compatibility mode is enabled then handoff processing
4547 * to the selinux_ip_postroute_compat() function to deal with the
4548 * special handling. We do this in an attempt to keep this function
4549 * as fast and as clean as possible. */
4550 if (!selinux_policycap_netpeer)
4551 return selinux_ip_postroute_compat(skb, ifindex, family);
4552 #ifdef CONFIG_XFRM
4553 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
4554 * packet transformation so allow the packet to pass without any checks
4555 * since we'll have another chance to perform access control checks
4556 * when the packet is on it's final way out.
4557 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
4558 * is NULL, in this case go ahead and apply access control. */
4559 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
4560 return NF_ACCEPT;
4561 #endif
4562 secmark_active = selinux_secmark_enabled();
4563 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4564 if (!secmark_active && !peerlbl_active)
4565 return NF_ACCEPT;
4566
4567 /* if the packet is being forwarded then get the peer label from the
4568 * packet itself; otherwise check to see if it is from a local
4569 * application or the kernel, if from an application get the peer label
4570 * from the sending socket, otherwise use the kernel's sid */
4571 sk = skb->sk;
4572 if (sk == NULL) {
4573 switch (family) {
4574 case PF_INET:
4575 if (IPCB(skb)->flags & IPSKB_FORWARDED)
4576 secmark_perm = PACKET__FORWARD_OUT;
4577 else
4578 secmark_perm = PACKET__SEND;
4579 break;
4580 case PF_INET6:
4581 if (IP6CB(skb)->flags & IP6SKB_FORWARDED)
4582 secmark_perm = PACKET__FORWARD_OUT;
4583 else
4584 secmark_perm = PACKET__SEND;
4585 break;
4586 default:
4587 return NF_DROP_ERR(-ECONNREFUSED);
4588 }
4589 if (secmark_perm == PACKET__FORWARD_OUT) {
4590 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4591 return NF_DROP;
4592 } else
4593 peer_sid = SECINITSID_KERNEL;
4594 } else {
4595 struct sk_security_struct *sksec = sk->sk_security;
4596 peer_sid = sksec->sid;
4597 secmark_perm = PACKET__SEND;
4598 }
4599
4600 COMMON_AUDIT_DATA_INIT(&ad, NET);
4601 ad.u.net.netif = ifindex;
4602 ad.u.net.family = family;
4603 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4604 return NF_DROP;
4605
4606 if (secmark_active)
4607 if (avc_has_perm(peer_sid, skb->secmark,
4608 SECCLASS_PACKET, secmark_perm, &ad))
4609 return NF_DROP_ERR(-ECONNREFUSED);
4610
4611 if (peerlbl_active) {
4612 u32 if_sid;
4613 u32 node_sid;
4614
4615 if (sel_netif_sid(ifindex, &if_sid))
4616 return NF_DROP;
4617 if (avc_has_perm(peer_sid, if_sid,
4618 SECCLASS_NETIF, NETIF__EGRESS, &ad))
4619 return NF_DROP_ERR(-ECONNREFUSED);
4620
4621 if (sel_netnode_sid(addrp, family, &node_sid))
4622 return NF_DROP;
4623 if (avc_has_perm(peer_sid, node_sid,
4624 SECCLASS_NODE, NODE__SENDTO, &ad))
4625 return NF_DROP_ERR(-ECONNREFUSED);
4626 }
4627
4628 return NF_ACCEPT;
4629 }
4630
4631 static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
4632 struct sk_buff *skb,
4633 const struct net_device *in,
4634 const struct net_device *out,
4635 int (*okfn)(struct sk_buff *))
4636 {
4637 return selinux_ip_postroute(skb, out->ifindex, PF_INET);
4638 }
4639
4640 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4641 static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
4642 struct sk_buff *skb,
4643 const struct net_device *in,
4644 const struct net_device *out,
4645 int (*okfn)(struct sk_buff *))
4646 {
4647 return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
4648 }
4649 #endif /* IPV6 */
4650
4651 #endif /* CONFIG_NETFILTER */
4652
4653 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
4654 {
4655 int err;
4656
4657 err = cap_netlink_send(sk, skb);
4658 if (err)
4659 return err;
4660
4661 return selinux_nlmsg_perm(sk, skb);
4662 }
4663
4664 static int selinux_netlink_recv(struct sk_buff *skb, int capability)
4665 {
4666 int err;
4667 struct common_audit_data ad;
4668
4669 err = cap_netlink_recv(skb, capability);
4670 if (err)
4671 return err;
4672
4673 COMMON_AUDIT_DATA_INIT(&ad, CAP);
4674 ad.u.cap = capability;
4675
4676 return avc_has_perm(NETLINK_CB(skb).sid, NETLINK_CB(skb).sid,
4677 SECCLASS_CAPABILITY, CAP_TO_MASK(capability), &ad);
4678 }
4679
4680 static int ipc_alloc_security(struct task_struct *task,
4681 struct kern_ipc_perm *perm,
4682 u16 sclass)
4683 {
4684 struct ipc_security_struct *isec;
4685 u32 sid;
4686
4687 isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
4688 if (!isec)
4689 return -ENOMEM;
4690
4691 sid = task_sid(task);
4692 isec->sclass = sclass;
4693 isec->sid = sid;
4694 perm->security = isec;
4695
4696 return 0;
4697 }
4698
4699 static void ipc_free_security(struct kern_ipc_perm *perm)
4700 {
4701 struct ipc_security_struct *isec = perm->security;
4702 perm->security = NULL;
4703 kfree(isec);
4704 }
4705
4706 static int msg_msg_alloc_security(struct msg_msg *msg)
4707 {
4708 struct msg_security_struct *msec;
4709
4710 msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
4711 if (!msec)
4712 return -ENOMEM;
4713
4714 msec->sid = SECINITSID_UNLABELED;
4715 msg->security = msec;
4716
4717 return 0;
4718 }
4719
4720 static void msg_msg_free_security(struct msg_msg *msg)
4721 {
4722 struct msg_security_struct *msec = msg->security;
4723
4724 msg->security = NULL;
4725 kfree(msec);
4726 }
4727
4728 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
4729 u32 perms)
4730 {
4731 struct ipc_security_struct *isec;
4732 struct common_audit_data ad;
4733 u32 sid = current_sid();
4734
4735 isec = ipc_perms->security;
4736
4737 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4738 ad.u.ipc_id = ipc_perms->key;
4739
4740 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
4741 }
4742
4743 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
4744 {
4745 return msg_msg_alloc_security(msg);
4746 }
4747
4748 static void selinux_msg_msg_free_security(struct msg_msg *msg)
4749 {
4750 msg_msg_free_security(msg);
4751 }
4752
4753 /* message queue security operations */
4754 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
4755 {
4756 struct ipc_security_struct *isec;
4757 struct common_audit_data ad;
4758 u32 sid = current_sid();
4759 int rc;
4760
4761 rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
4762 if (rc)
4763 return rc;
4764
4765 isec = msq->q_perm.security;
4766
4767 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4768 ad.u.ipc_id = msq->q_perm.key;
4769
4770 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4771 MSGQ__CREATE, &ad);
4772 if (rc) {
4773 ipc_free_security(&msq->q_perm);
4774 return rc;
4775 }
4776 return 0;
4777 }
4778
4779 static void selinux_msg_queue_free_security(struct msg_queue *msq)
4780 {
4781 ipc_free_security(&msq->q_perm);
4782 }
4783
4784 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
4785 {
4786 struct ipc_security_struct *isec;
4787 struct common_audit_data ad;
4788 u32 sid = current_sid();
4789
4790 isec = msq->q_perm.security;
4791
4792 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4793 ad.u.ipc_id = msq->q_perm.key;
4794
4795 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4796 MSGQ__ASSOCIATE, &ad);
4797 }
4798
4799 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
4800 {
4801 int err;
4802 int perms;
4803
4804 switch (cmd) {
4805 case IPC_INFO:
4806 case MSG_INFO:
4807 /* No specific object, just general system-wide information. */
4808 return task_has_system(current, SYSTEM__IPC_INFO);
4809 case IPC_STAT:
4810 case MSG_STAT:
4811 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
4812 break;
4813 case IPC_SET:
4814 perms = MSGQ__SETATTR;
4815 break;
4816 case IPC_RMID:
4817 perms = MSGQ__DESTROY;
4818 break;
4819 default:
4820 return 0;
4821 }
4822
4823 err = ipc_has_perm(&msq->q_perm, perms);
4824 return err;
4825 }
4826
4827 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
4828 {
4829 struct ipc_security_struct *isec;
4830 struct msg_security_struct *msec;
4831 struct common_audit_data ad;
4832 u32 sid = current_sid();
4833 int rc;
4834
4835 isec = msq->q_perm.security;
4836 msec = msg->security;
4837
4838 /*
4839 * First time through, need to assign label to the message
4840 */
4841 if (msec->sid == SECINITSID_UNLABELED) {
4842 /*
4843 * Compute new sid based on current process and
4844 * message queue this message will be stored in
4845 */
4846 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
4847 &msec->sid);
4848 if (rc)
4849 return rc;
4850 }
4851
4852 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4853 ad.u.ipc_id = msq->q_perm.key;
4854
4855 /* Can this process write to the queue? */
4856 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4857 MSGQ__WRITE, &ad);
4858 if (!rc)
4859 /* Can this process send the message */
4860 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
4861 MSG__SEND, &ad);
4862 if (!rc)
4863 /* Can the message be put in the queue? */
4864 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
4865 MSGQ__ENQUEUE, &ad);
4866
4867 return rc;
4868 }
4869
4870 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
4871 struct task_struct *target,
4872 long type, int mode)
4873 {
4874 struct ipc_security_struct *isec;
4875 struct msg_security_struct *msec;
4876 struct common_audit_data ad;
4877 u32 sid = task_sid(target);
4878 int rc;
4879
4880 isec = msq->q_perm.security;
4881 msec = msg->security;
4882
4883 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4884 ad.u.ipc_id = msq->q_perm.key;
4885
4886 rc = avc_has_perm(sid, isec->sid,
4887 SECCLASS_MSGQ, MSGQ__READ, &ad);
4888 if (!rc)
4889 rc = avc_has_perm(sid, msec->sid,
4890 SECCLASS_MSG, MSG__RECEIVE, &ad);
4891 return rc;
4892 }
4893
4894 /* Shared Memory security operations */
4895 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
4896 {
4897 struct ipc_security_struct *isec;
4898 struct common_audit_data ad;
4899 u32 sid = current_sid();
4900 int rc;
4901
4902 rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
4903 if (rc)
4904 return rc;
4905
4906 isec = shp->shm_perm.security;
4907
4908 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4909 ad.u.ipc_id = shp->shm_perm.key;
4910
4911 rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
4912 SHM__CREATE, &ad);
4913 if (rc) {
4914 ipc_free_security(&shp->shm_perm);
4915 return rc;
4916 }
4917 return 0;
4918 }
4919
4920 static void selinux_shm_free_security(struct shmid_kernel *shp)
4921 {
4922 ipc_free_security(&shp->shm_perm);
4923 }
4924
4925 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
4926 {
4927 struct ipc_security_struct *isec;
4928 struct common_audit_data ad;
4929 u32 sid = current_sid();
4930
4931 isec = shp->shm_perm.security;
4932
4933 COMMON_AUDIT_DATA_INIT(&ad, IPC);
4934 ad.u.ipc_id = shp->shm_perm.key;
4935
4936 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
4937 SHM__ASSOCIATE, &ad);
4938 }
4939
4940 /* Note, at this point, shp is locked down */
4941 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
4942 {
4943 int perms;
4944 int err;
4945
4946 switch (cmd) {
4947 case IPC_INFO:
4948 case SHM_INFO:
4949 /* No specific object, just general system-wide information. */
4950 return task_has_system(current, SYSTEM__IPC_INFO);
4951 case IPC_STAT:
4952 case SHM_STAT:
4953 perms = SHM__GETATTR | SHM__ASSOCIATE;
4954 break;
4955 case IPC_SET:
4956 perms = SHM__SETATTR;
4957 break;
4958 case SHM_LOCK:
4959 case SHM_UNLOCK:
4960 perms = SHM__LOCK;
4961 break;
4962 case IPC_RMID:
4963 perms = SHM__DESTROY;
4964 break;
4965 default:
4966 return 0;
4967 }
4968
4969 err = ipc_has_perm(&shp->shm_perm, perms);
4970 return err;
4971 }
4972
4973 static int selinux_shm_shmat(struct shmid_kernel *shp,
4974 char __user *shmaddr, int shmflg)
4975 {
4976 u32 perms;
4977
4978 if (shmflg & SHM_RDONLY)
4979 perms = SHM__READ;
4980 else
4981 perms = SHM__READ | SHM__WRITE;
4982
4983 return ipc_has_perm(&shp->shm_perm, perms);
4984 }
4985
4986 /* Semaphore security operations */
4987 static int selinux_sem_alloc_security(struct sem_array *sma)
4988 {
4989 struct ipc_security_struct *isec;
4990 struct common_audit_data ad;
4991 u32 sid = current_sid();
4992 int rc;
4993
4994 rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
4995 if (rc)
4996 return rc;
4997
4998 isec = sma->sem_perm.security;
4999
5000 COMMON_AUDIT_DATA_INIT(&ad, IPC);
5001 ad.u.ipc_id = sma->sem_perm.key;
5002
5003 rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5004 SEM__CREATE, &ad);
5005 if (rc) {
5006 ipc_free_security(&sma->sem_perm);
5007 return rc;
5008 }
5009 return 0;
5010 }
5011
5012 static void selinux_sem_free_security(struct sem_array *sma)
5013 {
5014 ipc_free_security(&sma->sem_perm);
5015 }
5016
5017 static int selinux_sem_associate(struct sem_array *sma, int semflg)
5018 {
5019 struct ipc_security_struct *isec;
5020 struct common_audit_data ad;
5021 u32 sid = current_sid();
5022
5023 isec = sma->sem_perm.security;
5024
5025 COMMON_AUDIT_DATA_INIT(&ad, IPC);
5026 ad.u.ipc_id = sma->sem_perm.key;
5027
5028 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5029 SEM__ASSOCIATE, &ad);
5030 }
5031
5032 /* Note, at this point, sma is locked down */
5033 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5034 {
5035 int err;
5036 u32 perms;
5037
5038 switch (cmd) {
5039 case IPC_INFO:
5040 case SEM_INFO:
5041 /* No specific object, just general system-wide information. */
5042 return task_has_system(current, SYSTEM__IPC_INFO);
5043 case GETPID:
5044 case GETNCNT:
5045 case GETZCNT:
5046 perms = SEM__GETATTR;
5047 break;
5048 case GETVAL:
5049 case GETALL:
5050 perms = SEM__READ;
5051 break;
5052 case SETVAL:
5053 case SETALL:
5054 perms = SEM__WRITE;
5055 break;
5056 case IPC_RMID:
5057 perms = SEM__DESTROY;
5058 break;
5059 case IPC_SET:
5060 perms = SEM__SETATTR;
5061 break;
5062 case IPC_STAT:
5063 case SEM_STAT:
5064 perms = SEM__GETATTR | SEM__ASSOCIATE;
5065 break;
5066 default:
5067 return 0;
5068 }
5069
5070 err = ipc_has_perm(&sma->sem_perm, perms);
5071 return err;
5072 }
5073
5074 static int selinux_sem_semop(struct sem_array *sma,
5075 struct sembuf *sops, unsigned nsops, int alter)
5076 {
5077 u32 perms;
5078
5079 if (alter)
5080 perms = SEM__READ | SEM__WRITE;
5081 else
5082 perms = SEM__READ;
5083
5084 return ipc_has_perm(&sma->sem_perm, perms);
5085 }
5086
5087 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5088 {
5089 u32 av = 0;
5090
5091 av = 0;
5092 if (flag & S_IRUGO)
5093 av |= IPC__UNIX_READ;
5094 if (flag & S_IWUGO)
5095 av |= IPC__UNIX_WRITE;
5096
5097 if (av == 0)
5098 return 0;
5099
5100 return ipc_has_perm(ipcp, av);
5101 }
5102
5103 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5104 {
5105 struct ipc_security_struct *isec = ipcp->security;
5106 *secid = isec->sid;
5107 }
5108
5109 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5110 {
5111 if (inode)
5112 inode_doinit_with_dentry(inode, dentry);
5113 }
5114
5115 static int selinux_getprocattr(struct task_struct *p,
5116 char *name, char **value)
5117 {
5118 const struct task_security_struct *__tsec;
5119 u32 sid;
5120 int error;
5121 unsigned len;
5122
5123 if (current != p) {
5124 error = current_has_perm(p, PROCESS__GETATTR);
5125 if (error)
5126 return error;
5127 }
5128
5129 rcu_read_lock();
5130 __tsec = __task_cred(p)->security;
5131
5132 if (!strcmp(name, "current"))
5133 sid = __tsec->sid;
5134 else if (!strcmp(name, "prev"))
5135 sid = __tsec->osid;
5136 else if (!strcmp(name, "exec"))
5137 sid = __tsec->exec_sid;
5138 else if (!strcmp(name, "fscreate"))
5139 sid = __tsec->create_sid;
5140 else if (!strcmp(name, "keycreate"))
5141 sid = __tsec->keycreate_sid;
5142 else if (!strcmp(name, "sockcreate"))
5143 sid = __tsec->sockcreate_sid;
5144 else
5145 goto invalid;
5146 rcu_read_unlock();
5147
5148 if (!sid)
5149 return 0;
5150
5151 error = security_sid_to_context(sid, value, &len);
5152 if (error)
5153 return error;
5154 return len;
5155
5156 invalid:
5157 rcu_read_unlock();
5158 return -EINVAL;
5159 }
5160
5161 static int selinux_setprocattr(struct task_struct *p,
5162 char *name, void *value, size_t size)
5163 {
5164 struct task_security_struct *tsec;
5165 struct task_struct *tracer;
5166 struct cred *new;
5167 u32 sid = 0, ptsid;
5168 int error;
5169 char *str = value;
5170
5171 if (current != p) {
5172 /* SELinux only allows a process to change its own
5173 security attributes. */
5174 return -EACCES;
5175 }
5176
5177 /*
5178 * Basic control over ability to set these attributes at all.
5179 * current == p, but we'll pass them separately in case the
5180 * above restriction is ever removed.
5181 */
5182 if (!strcmp(name, "exec"))
5183 error = current_has_perm(p, PROCESS__SETEXEC);
5184 else if (!strcmp(name, "fscreate"))
5185 error = current_has_perm(p, PROCESS__SETFSCREATE);
5186 else if (!strcmp(name, "keycreate"))
5187 error = current_has_perm(p, PROCESS__SETKEYCREATE);
5188 else if (!strcmp(name, "sockcreate"))
5189 error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5190 else if (!strcmp(name, "current"))
5191 error = current_has_perm(p, PROCESS__SETCURRENT);
5192 else
5193 error = -EINVAL;
5194 if (error)
5195 return error;
5196
5197 /* Obtain a SID for the context, if one was specified. */
5198 if (size && str[1] && str[1] != '\n') {
5199 if (str[size-1] == '\n') {
5200 str[size-1] = 0;
5201 size--;
5202 }
5203 error = security_context_to_sid(value, size, &sid);
5204 if (error == -EINVAL && !strcmp(name, "fscreate")) {
5205 if (!capable(CAP_MAC_ADMIN))
5206 return error;
5207 error = security_context_to_sid_force(value, size,
5208 &sid);
5209 }
5210 if (error)
5211 return error;
5212 }
5213
5214 new = prepare_creds();
5215 if (!new)
5216 return -ENOMEM;
5217
5218 /* Permission checking based on the specified context is
5219 performed during the actual operation (execve,
5220 open/mkdir/...), when we know the full context of the
5221 operation. See selinux_bprm_set_creds for the execve
5222 checks and may_create for the file creation checks. The
5223 operation will then fail if the context is not permitted. */
5224 tsec = new->security;
5225 if (!strcmp(name, "exec")) {
5226 tsec->exec_sid = sid;
5227 } else if (!strcmp(name, "fscreate")) {
5228 tsec->create_sid = sid;
5229 } else if (!strcmp(name, "keycreate")) {
5230 error = may_create_key(sid, p);
5231 if (error)
5232 goto abort_change;
5233 tsec->keycreate_sid = sid;
5234 } else if (!strcmp(name, "sockcreate")) {
5235 tsec->sockcreate_sid = sid;
5236 } else if (!strcmp(name, "current")) {
5237 error = -EINVAL;
5238 if (sid == 0)
5239 goto abort_change;
5240
5241 /* Only allow single threaded processes to change context */
5242 error = -EPERM;
5243 if (!current_is_single_threaded()) {
5244 error = security_bounded_transition(tsec->sid, sid);
5245 if (error)
5246 goto abort_change;
5247 }
5248
5249 /* Check permissions for the transition. */
5250 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5251 PROCESS__DYNTRANSITION, NULL);
5252 if (error)
5253 goto abort_change;
5254
5255 /* Check for ptracing, and update the task SID if ok.
5256 Otherwise, leave SID unchanged and fail. */
5257 ptsid = 0;
5258 task_lock(p);
5259 tracer = tracehook_tracer_task(p);
5260 if (tracer)
5261 ptsid = task_sid(tracer);
5262 task_unlock(p);
5263
5264 if (tracer) {
5265 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5266 PROCESS__PTRACE, NULL);
5267 if (error)
5268 goto abort_change;
5269 }
5270
5271 tsec->sid = sid;
5272 } else {
5273 error = -EINVAL;
5274 goto abort_change;
5275 }
5276
5277 commit_creds(new);
5278 return size;
5279
5280 abort_change:
5281 abort_creds(new);
5282 return error;
5283 }
5284
5285 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5286 {
5287 return security_sid_to_context(secid, secdata, seclen);
5288 }
5289
5290 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5291 {
5292 return security_context_to_sid(secdata, seclen, secid);
5293 }
5294
5295 static void selinux_release_secctx(char *secdata, u32 seclen)
5296 {
5297 kfree(secdata);
5298 }
5299
5300 /*
5301 * called with inode->i_mutex locked
5302 */
5303 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5304 {
5305 return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5306 }
5307
5308 /*
5309 * called with inode->i_mutex locked
5310 */
5311 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
5312 {
5313 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
5314 }
5315
5316 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
5317 {
5318 int len = 0;
5319 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
5320 ctx, true);
5321 if (len < 0)
5322 return len;
5323 *ctxlen = len;
5324 return 0;
5325 }
5326 #ifdef CONFIG_KEYS
5327
5328 static int selinux_key_alloc(struct key *k, const struct cred *cred,
5329 unsigned long flags)
5330 {
5331 const struct task_security_struct *tsec;
5332 struct key_security_struct *ksec;
5333
5334 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
5335 if (!ksec)
5336 return -ENOMEM;
5337
5338 tsec = cred->security;
5339 if (tsec->keycreate_sid)
5340 ksec->sid = tsec->keycreate_sid;
5341 else
5342 ksec->sid = tsec->sid;
5343
5344 k->security = ksec;
5345 return 0;
5346 }
5347
5348 static void selinux_key_free(struct key *k)
5349 {
5350 struct key_security_struct *ksec = k->security;
5351
5352 k->security = NULL;
5353 kfree(ksec);
5354 }
5355
5356 static int selinux_key_permission(key_ref_t key_ref,
5357 const struct cred *cred,
5358 key_perm_t perm)
5359 {
5360 struct key *key;
5361 struct key_security_struct *ksec;
5362 u32 sid;
5363
5364 /* if no specific permissions are requested, we skip the
5365 permission check. No serious, additional covert channels
5366 appear to be created. */
5367 if (perm == 0)
5368 return 0;
5369
5370 sid = cred_sid(cred);
5371
5372 key = key_ref_to_ptr(key_ref);
5373 ksec = key->security;
5374
5375 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5376 }
5377
5378 static int selinux_key_getsecurity(struct key *key, char **_buffer)
5379 {
5380 struct key_security_struct *ksec = key->security;
5381 char *context = NULL;
5382 unsigned len;
5383 int rc;
5384
5385 rc = security_sid_to_context(ksec->sid, &context, &len);
5386 if (!rc)
5387 rc = len;
5388 *_buffer = context;
5389 return rc;
5390 }
5391
5392 #endif
5393
5394 static struct security_operations selinux_ops = {
5395 .name = "selinux",
5396
5397 .ptrace_access_check = selinux_ptrace_access_check,
5398 .ptrace_traceme = selinux_ptrace_traceme,
5399 .capget = selinux_capget,
5400 .capset = selinux_capset,
5401 .sysctl = selinux_sysctl,
5402 .capable = selinux_capable,
5403 .quotactl = selinux_quotactl,
5404 .quota_on = selinux_quota_on,
5405 .syslog = selinux_syslog,
5406 .vm_enough_memory = selinux_vm_enough_memory,
5407
5408 .netlink_send = selinux_netlink_send,
5409 .netlink_recv = selinux_netlink_recv,
5410
5411 .bprm_set_creds = selinux_bprm_set_creds,
5412 .bprm_committing_creds = selinux_bprm_committing_creds,
5413 .bprm_committed_creds = selinux_bprm_committed_creds,
5414 .bprm_secureexec = selinux_bprm_secureexec,
5415
5416 .sb_alloc_security = selinux_sb_alloc_security,
5417 .sb_free_security = selinux_sb_free_security,
5418 .sb_copy_data = selinux_sb_copy_data,
5419 .sb_kern_mount = selinux_sb_kern_mount,
5420 .sb_show_options = selinux_sb_show_options,
5421 .sb_statfs = selinux_sb_statfs,
5422 .sb_mount = selinux_mount,
5423 .sb_umount = selinux_umount,
5424 .sb_set_mnt_opts = selinux_set_mnt_opts,
5425 .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts,
5426 .sb_parse_opts_str = selinux_parse_opts_str,
5427
5428
5429 .inode_alloc_security = selinux_inode_alloc_security,
5430 .inode_free_security = selinux_inode_free_security,
5431 .inode_init_security = selinux_inode_init_security,
5432 .inode_create = selinux_inode_create,
5433 .inode_link = selinux_inode_link,
5434 .inode_unlink = selinux_inode_unlink,
5435 .inode_symlink = selinux_inode_symlink,
5436 .inode_mkdir = selinux_inode_mkdir,
5437 .inode_rmdir = selinux_inode_rmdir,
5438 .inode_mknod = selinux_inode_mknod,
5439 .inode_rename = selinux_inode_rename,
5440 .inode_readlink = selinux_inode_readlink,
5441 .inode_follow_link = selinux_inode_follow_link,
5442 .inode_permission = selinux_inode_permission,
5443 .inode_setattr = selinux_inode_setattr,
5444 .inode_getattr = selinux_inode_getattr,
5445 .inode_setxattr = selinux_inode_setxattr,
5446 .inode_post_setxattr = selinux_inode_post_setxattr,
5447 .inode_getxattr = selinux_inode_getxattr,
5448 .inode_listxattr = selinux_inode_listxattr,
5449 .inode_removexattr = selinux_inode_removexattr,
5450 .inode_getsecurity = selinux_inode_getsecurity,
5451 .inode_setsecurity = selinux_inode_setsecurity,
5452 .inode_listsecurity = selinux_inode_listsecurity,
5453 .inode_getsecid = selinux_inode_getsecid,
5454
5455 .file_permission = selinux_file_permission,
5456 .file_alloc_security = selinux_file_alloc_security,
5457 .file_free_security = selinux_file_free_security,
5458 .file_ioctl = selinux_file_ioctl,
5459 .file_mmap = selinux_file_mmap,
5460 .file_mprotect = selinux_file_mprotect,
5461 .file_lock = selinux_file_lock,
5462 .file_fcntl = selinux_file_fcntl,
5463 .file_set_fowner = selinux_file_set_fowner,
5464 .file_send_sigiotask = selinux_file_send_sigiotask,
5465 .file_receive = selinux_file_receive,
5466
5467 .dentry_open = selinux_dentry_open,
5468
5469 .task_create = selinux_task_create,
5470 .cred_alloc_blank = selinux_cred_alloc_blank,
5471 .cred_free = selinux_cred_free,
5472 .cred_prepare = selinux_cred_prepare,
5473 .cred_transfer = selinux_cred_transfer,
5474 .kernel_act_as = selinux_kernel_act_as,
5475 .kernel_create_files_as = selinux_kernel_create_files_as,
5476 .kernel_module_request = selinux_kernel_module_request,
5477 .task_setpgid = selinux_task_setpgid,
5478 .task_getpgid = selinux_task_getpgid,
5479 .task_getsid = selinux_task_getsid,
5480 .task_getsecid = selinux_task_getsecid,
5481 .task_setnice = selinux_task_setnice,
5482 .task_setioprio = selinux_task_setioprio,
5483 .task_getioprio = selinux_task_getioprio,
5484 .task_setrlimit = selinux_task_setrlimit,
5485 .task_setscheduler = selinux_task_setscheduler,
5486 .task_getscheduler = selinux_task_getscheduler,
5487 .task_movememory = selinux_task_movememory,
5488 .task_kill = selinux_task_kill,
5489 .task_wait = selinux_task_wait,
5490 .task_to_inode = selinux_task_to_inode,
5491
5492 .ipc_permission = selinux_ipc_permission,
5493 .ipc_getsecid = selinux_ipc_getsecid,
5494
5495 .msg_msg_alloc_security = selinux_msg_msg_alloc_security,
5496 .msg_msg_free_security = selinux_msg_msg_free_security,
5497
5498 .msg_queue_alloc_security = selinux_msg_queue_alloc_security,
5499 .msg_queue_free_security = selinux_msg_queue_free_security,
5500 .msg_queue_associate = selinux_msg_queue_associate,
5501 .msg_queue_msgctl = selinux_msg_queue_msgctl,
5502 .msg_queue_msgsnd = selinux_msg_queue_msgsnd,
5503 .msg_queue_msgrcv = selinux_msg_queue_msgrcv,
5504
5505 .shm_alloc_security = selinux_shm_alloc_security,
5506 .shm_free_security = selinux_shm_free_security,
5507 .shm_associate = selinux_shm_associate,
5508 .shm_shmctl = selinux_shm_shmctl,
5509 .shm_shmat = selinux_shm_shmat,
5510
5511 .sem_alloc_security = selinux_sem_alloc_security,
5512 .sem_free_security = selinux_sem_free_security,
5513 .sem_associate = selinux_sem_associate,
5514 .sem_semctl = selinux_sem_semctl,
5515 .sem_semop = selinux_sem_semop,
5516
5517 .d_instantiate = selinux_d_instantiate,
5518
5519 .getprocattr = selinux_getprocattr,
5520 .setprocattr = selinux_setprocattr,
5521
5522 .secid_to_secctx = selinux_secid_to_secctx,
5523 .secctx_to_secid = selinux_secctx_to_secid,
5524 .release_secctx = selinux_release_secctx,
5525 .inode_notifysecctx = selinux_inode_notifysecctx,
5526 .inode_setsecctx = selinux_inode_setsecctx,
5527 .inode_getsecctx = selinux_inode_getsecctx,
5528
5529 .unix_stream_connect = selinux_socket_unix_stream_connect,
5530 .unix_may_send = selinux_socket_unix_may_send,
5531
5532 .socket_create = selinux_socket_create,
5533 .socket_post_create = selinux_socket_post_create,
5534 .socket_bind = selinux_socket_bind,
5535 .socket_connect = selinux_socket_connect,
5536 .socket_listen = selinux_socket_listen,
5537 .socket_accept = selinux_socket_accept,
5538 .socket_sendmsg = selinux_socket_sendmsg,
5539 .socket_recvmsg = selinux_socket_recvmsg,
5540 .socket_getsockname = selinux_socket_getsockname,
5541 .socket_getpeername = selinux_socket_getpeername,
5542 .socket_getsockopt = selinux_socket_getsockopt,
5543 .socket_setsockopt = selinux_socket_setsockopt,
5544 .socket_shutdown = selinux_socket_shutdown,
5545 .socket_sock_rcv_skb = selinux_socket_sock_rcv_skb,
5546 .socket_getpeersec_stream = selinux_socket_getpeersec_stream,
5547 .socket_getpeersec_dgram = selinux_socket_getpeersec_dgram,
5548 .sk_alloc_security = selinux_sk_alloc_security,
5549 .sk_free_security = selinux_sk_free_security,
5550 .sk_clone_security = selinux_sk_clone_security,
5551 .sk_getsecid = selinux_sk_getsecid,
5552 .sock_graft = selinux_sock_graft,
5553 .inet_conn_request = selinux_inet_conn_request,
5554 .inet_csk_clone = selinux_inet_csk_clone,
5555 .inet_conn_established = selinux_inet_conn_established,
5556 .secmark_relabel_packet = selinux_secmark_relabel_packet,
5557 .secmark_refcount_inc = selinux_secmark_refcount_inc,
5558 .secmark_refcount_dec = selinux_secmark_refcount_dec,
5559 .req_classify_flow = selinux_req_classify_flow,
5560 .tun_dev_create = selinux_tun_dev_create,
5561 .tun_dev_post_create = selinux_tun_dev_post_create,
5562 .tun_dev_attach = selinux_tun_dev_attach,
5563
5564 #ifdef CONFIG_SECURITY_NETWORK_XFRM
5565 .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc,
5566 .xfrm_policy_clone_security = selinux_xfrm_policy_clone,
5567 .xfrm_policy_free_security = selinux_xfrm_policy_free,
5568 .xfrm_policy_delete_security = selinux_xfrm_policy_delete,
5569 .xfrm_state_alloc_security = selinux_xfrm_state_alloc,
5570 .xfrm_state_free_security = selinux_xfrm_state_free,
5571 .xfrm_state_delete_security = selinux_xfrm_state_delete,
5572 .xfrm_policy_lookup = selinux_xfrm_policy_lookup,
5573 .xfrm_state_pol_flow_match = selinux_xfrm_state_pol_flow_match,
5574 .xfrm_decode_session = selinux_xfrm_decode_session,
5575 #endif
5576
5577 #ifdef CONFIG_KEYS
5578 .key_alloc = selinux_key_alloc,
5579 .key_free = selinux_key_free,
5580 .key_permission = selinux_key_permission,
5581 .key_getsecurity = selinux_key_getsecurity,
5582 #endif
5583
5584 #ifdef CONFIG_AUDIT
5585 .audit_rule_init = selinux_audit_rule_init,
5586 .audit_rule_known = selinux_audit_rule_known,
5587 .audit_rule_match = selinux_audit_rule_match,
5588 .audit_rule_free = selinux_audit_rule_free,
5589 #endif
5590 };
5591
5592 static __init int selinux_init(void)
5593 {
5594 if (!security_module_enable(&selinux_ops)) {
5595 selinux_enabled = 0;
5596 return 0;
5597 }
5598
5599 if (!selinux_enabled) {
5600 printk(KERN_INFO "SELinux: Disabled at boot.\n");
5601 return 0;
5602 }
5603
5604 printk(KERN_INFO "SELinux: Initializing.\n");
5605
5606 /* Set the security state for the initial task. */
5607 cred_init_security();
5608
5609 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
5610
5611 sel_inode_cache = kmem_cache_create("selinux_inode_security",
5612 sizeof(struct inode_security_struct),
5613 0, SLAB_PANIC, NULL);
5614 avc_init();
5615
5616 if (register_security(&selinux_ops))
5617 panic("SELinux: Unable to register with kernel.\n");
5618
5619 if (selinux_enforcing)
5620 printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n");
5621 else
5622 printk(KERN_DEBUG "SELinux: Starting in permissive mode\n");
5623
5624 return 0;
5625 }
5626
5627 static void delayed_superblock_init(struct super_block *sb, void *unused)
5628 {
5629 superblock_doinit(sb, NULL);
5630 }
5631
5632 void selinux_complete_init(void)
5633 {
5634 printk(KERN_DEBUG "SELinux: Completing initialization.\n");
5635
5636 /* Set up any superblocks initialized prior to the policy load. */
5637 printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n");
5638 iterate_supers(delayed_superblock_init, NULL);
5639 }
5640
5641 /* SELinux requires early initialization in order to label
5642 all processes and objects when they are created. */
5643 security_initcall(selinux_init);
5644
5645 #if defined(CONFIG_NETFILTER)
5646
5647 static struct nf_hook_ops selinux_ipv4_ops[] = {
5648 {
5649 .hook = selinux_ipv4_postroute,
5650 .owner = THIS_MODULE,
5651 .pf = PF_INET,
5652 .hooknum = NF_INET_POST_ROUTING,
5653 .priority = NF_IP_PRI_SELINUX_LAST,
5654 },
5655 {
5656 .hook = selinux_ipv4_forward,
5657 .owner = THIS_MODULE,
5658 .pf = PF_INET,
5659 .hooknum = NF_INET_FORWARD,
5660 .priority = NF_IP_PRI_SELINUX_FIRST,
5661 },
5662 {
5663 .hook = selinux_ipv4_output,
5664 .owner = THIS_MODULE,
5665 .pf = PF_INET,
5666 .hooknum = NF_INET_LOCAL_OUT,
5667 .priority = NF_IP_PRI_SELINUX_FIRST,
5668 }
5669 };
5670
5671 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5672
5673 static struct nf_hook_ops selinux_ipv6_ops[] = {
5674 {
5675 .hook = selinux_ipv6_postroute,
5676 .owner = THIS_MODULE,
5677 .pf = PF_INET6,
5678 .hooknum = NF_INET_POST_ROUTING,
5679 .priority = NF_IP6_PRI_SELINUX_LAST,
5680 },
5681 {
5682 .hook = selinux_ipv6_forward,
5683 .owner = THIS_MODULE,
5684 .pf = PF_INET6,
5685 .hooknum = NF_INET_FORWARD,
5686 .priority = NF_IP6_PRI_SELINUX_FIRST,
5687 }
5688 };
5689
5690 #endif /* IPV6 */
5691
5692 static int __init selinux_nf_ip_init(void)
5693 {
5694 int err = 0;
5695
5696 if (!selinux_enabled)
5697 goto out;
5698
5699 printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n");
5700
5701 err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5702 if (err)
5703 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
5704
5705 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5706 err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5707 if (err)
5708 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
5709 #endif /* IPV6 */
5710
5711 out:
5712 return err;
5713 }
5714
5715 __initcall(selinux_nf_ip_init);
5716
5717 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5718 static void selinux_nf_ip_exit(void)
5719 {
5720 printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n");
5721
5722 nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5723 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5724 nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5725 #endif /* IPV6 */
5726 }
5727 #endif
5728
5729 #else /* CONFIG_NETFILTER */
5730
5731 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5732 #define selinux_nf_ip_exit()
5733 #endif
5734
5735 #endif /* CONFIG_NETFILTER */
5736
5737 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5738 static int selinux_disabled;
5739
5740 int selinux_disable(void)
5741 {
5742 extern void exit_sel_fs(void);
5743
5744 if (ss_initialized) {
5745 /* Not permitted after initial policy load. */
5746 return -EINVAL;
5747 }
5748
5749 if (selinux_disabled) {
5750 /* Only do this once. */
5751 return -EINVAL;
5752 }
5753
5754 printk(KERN_INFO "SELinux: Disabled at runtime.\n");
5755
5756 selinux_disabled = 1;
5757 selinux_enabled = 0;
5758
5759 reset_security_ops();
5760
5761 /* Try to destroy the avc node cache */
5762 avc_disable();
5763
5764 /* Unregister netfilter hooks. */
5765 selinux_nf_ip_exit();
5766
5767 /* Unregister selinuxfs. */
5768 exit_sel_fs();
5769
5770 return 0;
5771 }
5772 #endif
Linux kernel - Deliverables
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