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[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@paul-moore.com>
18 * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
19 * Yuichi Nakamura <ynakam@hitachisoft.jp>
20 *
21 * This program is free software; you can redistribute it and/or modify
22 * it under the terms of the GNU General Public License version 2,
23 * as published by the Free Software Foundation.
24 */
25
26 #include <linux/init.h>
27 #include <linux/kd.h>
28 #include <linux/kernel.h>
29 #include <linux/tracehook.h>
30 #include <linux/errno.h>
31 #include <linux/sched.h>
32 #include <linux/security.h>
33 #include <linux/xattr.h>
34 #include <linux/capability.h>
35 #include <linux/unistd.h>
36 #include <linux/mm.h>
37 #include <linux/mman.h>
38 #include <linux/slab.h>
39 #include <linux/pagemap.h>
40 #include <linux/proc_fs.h>
41 #include <linux/swap.h>
42 #include <linux/spinlock.h>
43 #include <linux/syscalls.h>
44 #include <linux/dcache.h>
45 #include <linux/file.h>
46 #include <linux/fdtable.h>
47 #include <linux/namei.h>
48 #include <linux/mount.h>
49 #include <linux/netfilter_ipv4.h>
50 #include <linux/netfilter_ipv6.h>
51 #include <linux/tty.h>
52 #include <net/icmp.h>
53 #include <net/ip.h> /* for local_port_range[] */
54 #include <net/sock.h>
55 #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
56 #include <net/inet_connection_sock.h>
57 #include <net/net_namespace.h>
58 #include <net/netlabel.h>
59 #include <linux/uaccess.h>
60 #include <asm/ioctls.h>
61 #include <linux/atomic.h>
62 #include <linux/bitops.h>
63 #include <linux/interrupt.h>
64 #include <linux/netdevice.h> /* for network interface checks */
65 #include <net/netlink.h>
66 #include <linux/tcp.h>
67 #include <linux/udp.h>
68 #include <linux/dccp.h>
69 #include <linux/quota.h>
70 #include <linux/un.h> /* for Unix socket types */
71 #include <net/af_unix.h> /* for Unix socket types */
72 #include <linux/parser.h>
73 #include <linux/nfs_mount.h>
74 #include <net/ipv6.h>
75 #include <linux/hugetlb.h>
76 #include <linux/personality.h>
77 #include <linux/audit.h>
78 #include <linux/string.h>
79 #include <linux/selinux.h>
80 #include <linux/mutex.h>
81 #include <linux/posix-timers.h>
82 #include <linux/syslog.h>
83 #include <linux/user_namespace.h>
84 #include <linux/export.h>
85 #include <linux/msg.h>
86 #include <linux/shm.h>
87
88 #include "avc.h"
89 #include "objsec.h"
90 #include "netif.h"
91 #include "netnode.h"
92 #include "netport.h"
93 #include "xfrm.h"
94 #include "netlabel.h"
95 #include "audit.h"
96 #include "avc_ss.h"
97
98 /* SECMARK reference count */
99 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
100
101 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
102 int selinux_enforcing;
103
104 static int __init enforcing_setup(char *str)
105 {
106 unsigned long enforcing;
107 if (!kstrtoul(str, 0, &enforcing))
108 selinux_enforcing = enforcing ? 1 : 0;
109 return 1;
110 }
111 __setup("enforcing=", enforcing_setup);
112 #endif
113
114 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
115 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
116
117 static int __init selinux_enabled_setup(char *str)
118 {
119 unsigned long enabled;
120 if (!kstrtoul(str, 0, &enabled))
121 selinux_enabled = enabled ? 1 : 0;
122 return 1;
123 }
124 __setup("selinux=", selinux_enabled_setup);
125 #else
126 int selinux_enabled = 1;
127 #endif
128
129 static struct kmem_cache *sel_inode_cache;
130
131 /**
132 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
133 *
134 * Description:
135 * This function checks the SECMARK reference counter to see if any SECMARK
136 * targets are currently configured, if the reference counter is greater than
137 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is
138 * enabled, false (0) if SECMARK is disabled. If the always_check_network
139 * policy capability is enabled, SECMARK is always considered enabled.
140 *
141 */
142 static int selinux_secmark_enabled(void)
143 {
144 return (selinux_policycap_alwaysnetwork || atomic_read(&selinux_secmark_refcount));
145 }
146
147 /**
148 * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled
149 *
150 * Description:
151 * This function checks if NetLabel or labeled IPSEC is enabled. Returns true
152 * (1) if any are enabled or false (0) if neither are enabled. If the
153 * always_check_network policy capability is enabled, peer labeling
154 * is always considered enabled.
155 *
156 */
157 static int selinux_peerlbl_enabled(void)
158 {
159 return (selinux_policycap_alwaysnetwork || netlbl_enabled() || selinux_xfrm_enabled());
160 }
161
162 static int selinux_netcache_avc_callback(u32 event)
163 {
164 if (event == AVC_CALLBACK_RESET) {
165 sel_netif_flush();
166 sel_netnode_flush();
167 sel_netport_flush();
168 synchronize_net();
169 }
170 return 0;
171 }
172
173 /*
174 * initialise the security for the init task
175 */
176 static void cred_init_security(void)
177 {
178 struct cred *cred = (struct cred *) current->real_cred;
179 struct task_security_struct *tsec;
180
181 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
182 if (!tsec)
183 panic("SELinux: Failed to initialize initial task.\n");
184
185 tsec->osid = tsec->sid = SECINITSID_KERNEL;
186 cred->security = tsec;
187 }
188
189 /*
190 * get the security ID of a set of credentials
191 */
192 static inline u32 cred_sid(const struct cred *cred)
193 {
194 const struct task_security_struct *tsec;
195
196 tsec = cred->security;
197 return tsec->sid;
198 }
199
200 /*
201 * get the objective security ID of a task
202 */
203 static inline u32 task_sid(const struct task_struct *task)
204 {
205 u32 sid;
206
207 rcu_read_lock();
208 sid = cred_sid(__task_cred(task));
209 rcu_read_unlock();
210 return sid;
211 }
212
213 /*
214 * get the subjective security ID of the current task
215 */
216 static inline u32 current_sid(void)
217 {
218 const struct task_security_struct *tsec = current_security();
219
220 return tsec->sid;
221 }
222
223 /* Allocate and free functions for each kind of security blob. */
224
225 static int inode_alloc_security(struct inode *inode)
226 {
227 struct inode_security_struct *isec;
228 u32 sid = current_sid();
229
230 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
231 if (!isec)
232 return -ENOMEM;
233
234 mutex_init(&isec->lock);
235 INIT_LIST_HEAD(&isec->list);
236 isec->inode = inode;
237 isec->sid = SECINITSID_UNLABELED;
238 isec->sclass = SECCLASS_FILE;
239 isec->task_sid = sid;
240 inode->i_security = isec;
241
242 return 0;
243 }
244
245 static void inode_free_rcu(struct rcu_head *head)
246 {
247 struct inode_security_struct *isec;
248
249 isec = container_of(head, struct inode_security_struct, rcu);
250 kmem_cache_free(sel_inode_cache, isec);
251 }
252
253 static void inode_free_security(struct inode *inode)
254 {
255 struct inode_security_struct *isec = inode->i_security;
256 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
257
258 spin_lock(&sbsec->isec_lock);
259 if (!list_empty(&isec->list))
260 list_del_init(&isec->list);
261 spin_unlock(&sbsec->isec_lock);
262
263 /*
264 * The inode may still be referenced in a path walk and
265 * a call to selinux_inode_permission() can be made
266 * after inode_free_security() is called. Ideally, the VFS
267 * wouldn't do this, but fixing that is a much harder
268 * job. For now, simply free the i_security via RCU, and
269 * leave the current inode->i_security pointer intact.
270 * The inode will be freed after the RCU grace period too.
271 */
272 call_rcu(&isec->rcu, inode_free_rcu);
273 }
274
275 static int file_alloc_security(struct file *file)
276 {
277 struct file_security_struct *fsec;
278 u32 sid = current_sid();
279
280 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
281 if (!fsec)
282 return -ENOMEM;
283
284 fsec->sid = sid;
285 fsec->fown_sid = sid;
286 file->f_security = fsec;
287
288 return 0;
289 }
290
291 static void file_free_security(struct file *file)
292 {
293 struct file_security_struct *fsec = file->f_security;
294 file->f_security = NULL;
295 kfree(fsec);
296 }
297
298 static int superblock_alloc_security(struct super_block *sb)
299 {
300 struct superblock_security_struct *sbsec;
301
302 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
303 if (!sbsec)
304 return -ENOMEM;
305
306 mutex_init(&sbsec->lock);
307 INIT_LIST_HEAD(&sbsec->isec_head);
308 spin_lock_init(&sbsec->isec_lock);
309 sbsec->sb = sb;
310 sbsec->sid = SECINITSID_UNLABELED;
311 sbsec->def_sid = SECINITSID_FILE;
312 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
313 sb->s_security = sbsec;
314
315 return 0;
316 }
317
318 static void superblock_free_security(struct super_block *sb)
319 {
320 struct superblock_security_struct *sbsec = sb->s_security;
321 sb->s_security = NULL;
322 kfree(sbsec);
323 }
324
325 /* The file system's label must be initialized prior to use. */
326
327 static const char *labeling_behaviors[7] = {
328 "uses xattr",
329 "uses transition SIDs",
330 "uses task SIDs",
331 "uses genfs_contexts",
332 "not configured for labeling",
333 "uses mountpoint labeling",
334 "uses native labeling",
335 };
336
337 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
338
339 static inline int inode_doinit(struct inode *inode)
340 {
341 return inode_doinit_with_dentry(inode, NULL);
342 }
343
344 enum {
345 Opt_error = -1,
346 Opt_context = 1,
347 Opt_fscontext = 2,
348 Opt_defcontext = 3,
349 Opt_rootcontext = 4,
350 Opt_labelsupport = 5,
351 Opt_nextmntopt = 6,
352 };
353
354 #define NUM_SEL_MNT_OPTS (Opt_nextmntopt - 1)
355
356 static const match_table_t tokens = {
357 {Opt_context, CONTEXT_STR "%s"},
358 {Opt_fscontext, FSCONTEXT_STR "%s"},
359 {Opt_defcontext, DEFCONTEXT_STR "%s"},
360 {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
361 {Opt_labelsupport, LABELSUPP_STR},
362 {Opt_error, NULL},
363 };
364
365 #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
366
367 static int may_context_mount_sb_relabel(u32 sid,
368 struct superblock_security_struct *sbsec,
369 const struct cred *cred)
370 {
371 const struct task_security_struct *tsec = cred->security;
372 int rc;
373
374 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
375 FILESYSTEM__RELABELFROM, NULL);
376 if (rc)
377 return rc;
378
379 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
380 FILESYSTEM__RELABELTO, NULL);
381 return rc;
382 }
383
384 static int may_context_mount_inode_relabel(u32 sid,
385 struct superblock_security_struct *sbsec,
386 const struct cred *cred)
387 {
388 const struct task_security_struct *tsec = cred->security;
389 int rc;
390 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
391 FILESYSTEM__RELABELFROM, NULL);
392 if (rc)
393 return rc;
394
395 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
396 FILESYSTEM__ASSOCIATE, NULL);
397 return rc;
398 }
399
400 static int selinux_is_sblabel_mnt(struct super_block *sb)
401 {
402 struct superblock_security_struct *sbsec = sb->s_security;
403
404 return sbsec->behavior == SECURITY_FS_USE_XATTR ||
405 sbsec->behavior == SECURITY_FS_USE_TRANS ||
406 sbsec->behavior == SECURITY_FS_USE_TASK ||
407 /* Special handling. Genfs but also in-core setxattr handler */
408 !strcmp(sb->s_type->name, "sysfs") ||
409 !strcmp(sb->s_type->name, "pstore") ||
410 !strcmp(sb->s_type->name, "debugfs") ||
411 !strcmp(sb->s_type->name, "rootfs");
412 }
413
414 static int sb_finish_set_opts(struct super_block *sb)
415 {
416 struct superblock_security_struct *sbsec = sb->s_security;
417 struct dentry *root = sb->s_root;
418 struct inode *root_inode = root->d_inode;
419 int rc = 0;
420
421 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
422 /* Make sure that the xattr handler exists and that no
423 error other than -ENODATA is returned by getxattr on
424 the root directory. -ENODATA is ok, as this may be
425 the first boot of the SELinux kernel before we have
426 assigned xattr values to the filesystem. */
427 if (!root_inode->i_op->getxattr) {
428 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
429 "xattr support\n", sb->s_id, sb->s_type->name);
430 rc = -EOPNOTSUPP;
431 goto out;
432 }
433 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
434 if (rc < 0 && rc != -ENODATA) {
435 if (rc == -EOPNOTSUPP)
436 printk(KERN_WARNING "SELinux: (dev %s, type "
437 "%s) has no security xattr handler\n",
438 sb->s_id, sb->s_type->name);
439 else
440 printk(KERN_WARNING "SELinux: (dev %s, type "
441 "%s) getxattr errno %d\n", sb->s_id,
442 sb->s_type->name, -rc);
443 goto out;
444 }
445 }
446
447 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
448 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
449 sb->s_id, sb->s_type->name);
450
451 sbsec->flags |= SE_SBINITIALIZED;
452 if (selinux_is_sblabel_mnt(sb))
453 sbsec->flags |= SBLABEL_MNT;
454
455 /* Initialize the root inode. */
456 rc = inode_doinit_with_dentry(root_inode, root);
457
458 /* Initialize any other inodes associated with the superblock, e.g.
459 inodes created prior to initial policy load or inodes created
460 during get_sb by a pseudo filesystem that directly
461 populates itself. */
462 spin_lock(&sbsec->isec_lock);
463 next_inode:
464 if (!list_empty(&sbsec->isec_head)) {
465 struct inode_security_struct *isec =
466 list_entry(sbsec->isec_head.next,
467 struct inode_security_struct, list);
468 struct inode *inode = isec->inode;
469 list_del_init(&isec->list);
470 spin_unlock(&sbsec->isec_lock);
471 inode = igrab(inode);
472 if (inode) {
473 if (!IS_PRIVATE(inode))
474 inode_doinit(inode);
475 iput(inode);
476 }
477 spin_lock(&sbsec->isec_lock);
478 goto next_inode;
479 }
480 spin_unlock(&sbsec->isec_lock);
481 out:
482 return rc;
483 }
484
485 /*
486 * This function should allow an FS to ask what it's mount security
487 * options were so it can use those later for submounts, displaying
488 * mount options, or whatever.
489 */
490 static int selinux_get_mnt_opts(const struct super_block *sb,
491 struct security_mnt_opts *opts)
492 {
493 int rc = 0, i;
494 struct superblock_security_struct *sbsec = sb->s_security;
495 char *context = NULL;
496 u32 len;
497 char tmp;
498
499 security_init_mnt_opts(opts);
500
501 if (!(sbsec->flags & SE_SBINITIALIZED))
502 return -EINVAL;
503
504 if (!ss_initialized)
505 return -EINVAL;
506
507 /* make sure we always check enough bits to cover the mask */
508 BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS));
509
510 tmp = sbsec->flags & SE_MNTMASK;
511 /* count the number of mount options for this sb */
512 for (i = 0; i < NUM_SEL_MNT_OPTS; i++) {
513 if (tmp & 0x01)
514 opts->num_mnt_opts++;
515 tmp >>= 1;
516 }
517 /* Check if the Label support flag is set */
518 if (sbsec->flags & SBLABEL_MNT)
519 opts->num_mnt_opts++;
520
521 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
522 if (!opts->mnt_opts) {
523 rc = -ENOMEM;
524 goto out_free;
525 }
526
527 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
528 if (!opts->mnt_opts_flags) {
529 rc = -ENOMEM;
530 goto out_free;
531 }
532
533 i = 0;
534 if (sbsec->flags & FSCONTEXT_MNT) {
535 rc = security_sid_to_context(sbsec->sid, &context, &len);
536 if (rc)
537 goto out_free;
538 opts->mnt_opts[i] = context;
539 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
540 }
541 if (sbsec->flags & CONTEXT_MNT) {
542 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
543 if (rc)
544 goto out_free;
545 opts->mnt_opts[i] = context;
546 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
547 }
548 if (sbsec->flags & DEFCONTEXT_MNT) {
549 rc = security_sid_to_context(sbsec->def_sid, &context, &len);
550 if (rc)
551 goto out_free;
552 opts->mnt_opts[i] = context;
553 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
554 }
555 if (sbsec->flags & ROOTCONTEXT_MNT) {
556 struct inode *root = sbsec->sb->s_root->d_inode;
557 struct inode_security_struct *isec = root->i_security;
558
559 rc = security_sid_to_context(isec->sid, &context, &len);
560 if (rc)
561 goto out_free;
562 opts->mnt_opts[i] = context;
563 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
564 }
565 if (sbsec->flags & SBLABEL_MNT) {
566 opts->mnt_opts[i] = NULL;
567 opts->mnt_opts_flags[i++] = SBLABEL_MNT;
568 }
569
570 BUG_ON(i != opts->num_mnt_opts);
571
572 return 0;
573
574 out_free:
575 security_free_mnt_opts(opts);
576 return rc;
577 }
578
579 static int bad_option(struct superblock_security_struct *sbsec, char flag,
580 u32 old_sid, u32 new_sid)
581 {
582 char mnt_flags = sbsec->flags & SE_MNTMASK;
583
584 /* check if the old mount command had the same options */
585 if (sbsec->flags & SE_SBINITIALIZED)
586 if (!(sbsec->flags & flag) ||
587 (old_sid != new_sid))
588 return 1;
589
590 /* check if we were passed the same options twice,
591 * aka someone passed context=a,context=b
592 */
593 if (!(sbsec->flags & SE_SBINITIALIZED))
594 if (mnt_flags & flag)
595 return 1;
596 return 0;
597 }
598
599 /*
600 * Allow filesystems with binary mount data to explicitly set mount point
601 * labeling information.
602 */
603 static int selinux_set_mnt_opts(struct super_block *sb,
604 struct security_mnt_opts *opts,
605 unsigned long kern_flags,
606 unsigned long *set_kern_flags)
607 {
608 const struct cred *cred = current_cred();
609 int rc = 0, i;
610 struct superblock_security_struct *sbsec = sb->s_security;
611 const char *name = sb->s_type->name;
612 struct inode *inode = sbsec->sb->s_root->d_inode;
613 struct inode_security_struct *root_isec = inode->i_security;
614 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
615 u32 defcontext_sid = 0;
616 char **mount_options = opts->mnt_opts;
617 int *flags = opts->mnt_opts_flags;
618 int num_opts = opts->num_mnt_opts;
619
620 mutex_lock(&sbsec->lock);
621
622 if (!ss_initialized) {
623 if (!num_opts) {
624 /* Defer initialization until selinux_complete_init,
625 after the initial policy is loaded and the security
626 server is ready to handle calls. */
627 goto out;
628 }
629 rc = -EINVAL;
630 printk(KERN_WARNING "SELinux: Unable to set superblock options "
631 "before the security server is initialized\n");
632 goto out;
633 }
634 if (kern_flags && !set_kern_flags) {
635 /* Specifying internal flags without providing a place to
636 * place the results is not allowed */
637 rc = -EINVAL;
638 goto out;
639 }
640
641 /*
642 * Binary mount data FS will come through this function twice. Once
643 * from an explicit call and once from the generic calls from the vfs.
644 * Since the generic VFS calls will not contain any security mount data
645 * we need to skip the double mount verification.
646 *
647 * This does open a hole in which we will not notice if the first
648 * mount using this sb set explict options and a second mount using
649 * this sb does not set any security options. (The first options
650 * will be used for both mounts)
651 */
652 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
653 && (num_opts == 0))
654 goto out;
655
656 /*
657 * parse the mount options, check if they are valid sids.
658 * also check if someone is trying to mount the same sb more
659 * than once with different security options.
660 */
661 for (i = 0; i < num_opts; i++) {
662 u32 sid;
663
664 if (flags[i] == SBLABEL_MNT)
665 continue;
666 rc = security_context_to_sid(mount_options[i],
667 strlen(mount_options[i]), &sid, GFP_KERNEL);
668 if (rc) {
669 printk(KERN_WARNING "SELinux: security_context_to_sid"
670 "(%s) failed for (dev %s, type %s) errno=%d\n",
671 mount_options[i], sb->s_id, name, rc);
672 goto out;
673 }
674 switch (flags[i]) {
675 case FSCONTEXT_MNT:
676 fscontext_sid = sid;
677
678 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
679 fscontext_sid))
680 goto out_double_mount;
681
682 sbsec->flags |= FSCONTEXT_MNT;
683 break;
684 case CONTEXT_MNT:
685 context_sid = sid;
686
687 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
688 context_sid))
689 goto out_double_mount;
690
691 sbsec->flags |= CONTEXT_MNT;
692 break;
693 case ROOTCONTEXT_MNT:
694 rootcontext_sid = sid;
695
696 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
697 rootcontext_sid))
698 goto out_double_mount;
699
700 sbsec->flags |= ROOTCONTEXT_MNT;
701
702 break;
703 case DEFCONTEXT_MNT:
704 defcontext_sid = sid;
705
706 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
707 defcontext_sid))
708 goto out_double_mount;
709
710 sbsec->flags |= DEFCONTEXT_MNT;
711
712 break;
713 default:
714 rc = -EINVAL;
715 goto out;
716 }
717 }
718
719 if (sbsec->flags & SE_SBINITIALIZED) {
720 /* previously mounted with options, but not on this attempt? */
721 if ((sbsec->flags & SE_MNTMASK) && !num_opts)
722 goto out_double_mount;
723 rc = 0;
724 goto out;
725 }
726
727 if (strcmp(sb->s_type->name, "proc") == 0)
728 sbsec->flags |= SE_SBPROC;
729
730 if (!sbsec->behavior) {
731 /*
732 * Determine the labeling behavior to use for this
733 * filesystem type.
734 */
735 rc = security_fs_use(sb);
736 if (rc) {
737 printk(KERN_WARNING
738 "%s: security_fs_use(%s) returned %d\n",
739 __func__, sb->s_type->name, rc);
740 goto out;
741 }
742 }
743 /* sets the context of the superblock for the fs being mounted. */
744 if (fscontext_sid) {
745 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
746 if (rc)
747 goto out;
748
749 sbsec->sid = fscontext_sid;
750 }
751
752 /*
753 * Switch to using mount point labeling behavior.
754 * sets the label used on all file below the mountpoint, and will set
755 * the superblock context if not already set.
756 */
757 if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
758 sbsec->behavior = SECURITY_FS_USE_NATIVE;
759 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
760 }
761
762 if (context_sid) {
763 if (!fscontext_sid) {
764 rc = may_context_mount_sb_relabel(context_sid, sbsec,
765 cred);
766 if (rc)
767 goto out;
768 sbsec->sid = context_sid;
769 } else {
770 rc = may_context_mount_inode_relabel(context_sid, sbsec,
771 cred);
772 if (rc)
773 goto out;
774 }
775 if (!rootcontext_sid)
776 rootcontext_sid = context_sid;
777
778 sbsec->mntpoint_sid = context_sid;
779 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
780 }
781
782 if (rootcontext_sid) {
783 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
784 cred);
785 if (rc)
786 goto out;
787
788 root_isec->sid = rootcontext_sid;
789 root_isec->initialized = 1;
790 }
791
792 if (defcontext_sid) {
793 if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
794 sbsec->behavior != SECURITY_FS_USE_NATIVE) {
795 rc = -EINVAL;
796 printk(KERN_WARNING "SELinux: defcontext option is "
797 "invalid for this filesystem type\n");
798 goto out;
799 }
800
801 if (defcontext_sid != sbsec->def_sid) {
802 rc = may_context_mount_inode_relabel(defcontext_sid,
803 sbsec, cred);
804 if (rc)
805 goto out;
806 }
807
808 sbsec->def_sid = defcontext_sid;
809 }
810
811 rc = sb_finish_set_opts(sb);
812 out:
813 mutex_unlock(&sbsec->lock);
814 return rc;
815 out_double_mount:
816 rc = -EINVAL;
817 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different "
818 "security settings for (dev %s, type %s)\n", sb->s_id, name);
819 goto out;
820 }
821
822 static int selinux_cmp_sb_context(const struct super_block *oldsb,
823 const struct super_block *newsb)
824 {
825 struct superblock_security_struct *old = oldsb->s_security;
826 struct superblock_security_struct *new = newsb->s_security;
827 char oldflags = old->flags & SE_MNTMASK;
828 char newflags = new->flags & SE_MNTMASK;
829
830 if (oldflags != newflags)
831 goto mismatch;
832 if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
833 goto mismatch;
834 if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
835 goto mismatch;
836 if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
837 goto mismatch;
838 if (oldflags & ROOTCONTEXT_MNT) {
839 struct inode_security_struct *oldroot = oldsb->s_root->d_inode->i_security;
840 struct inode_security_struct *newroot = newsb->s_root->d_inode->i_security;
841 if (oldroot->sid != newroot->sid)
842 goto mismatch;
843 }
844 return 0;
845 mismatch:
846 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, "
847 "different security settings for (dev %s, "
848 "type %s)\n", newsb->s_id, newsb->s_type->name);
849 return -EBUSY;
850 }
851
852 static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
853 struct super_block *newsb)
854 {
855 const struct superblock_security_struct *oldsbsec = oldsb->s_security;
856 struct superblock_security_struct *newsbsec = newsb->s_security;
857
858 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT);
859 int set_context = (oldsbsec->flags & CONTEXT_MNT);
860 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT);
861
862 /*
863 * if the parent was able to be mounted it clearly had no special lsm
864 * mount options. thus we can safely deal with this superblock later
865 */
866 if (!ss_initialized)
867 return 0;
868
869 /* how can we clone if the old one wasn't set up?? */
870 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
871
872 /* if fs is reusing a sb, make sure that the contexts match */
873 if (newsbsec->flags & SE_SBINITIALIZED)
874 return selinux_cmp_sb_context(oldsb, newsb);
875
876 mutex_lock(&newsbsec->lock);
877
878 newsbsec->flags = oldsbsec->flags;
879
880 newsbsec->sid = oldsbsec->sid;
881 newsbsec->def_sid = oldsbsec->def_sid;
882 newsbsec->behavior = oldsbsec->behavior;
883
884 if (set_context) {
885 u32 sid = oldsbsec->mntpoint_sid;
886
887 if (!set_fscontext)
888 newsbsec->sid = sid;
889 if (!set_rootcontext) {
890 struct inode *newinode = newsb->s_root->d_inode;
891 struct inode_security_struct *newisec = newinode->i_security;
892 newisec->sid = sid;
893 }
894 newsbsec->mntpoint_sid = sid;
895 }
896 if (set_rootcontext) {
897 const struct inode *oldinode = oldsb->s_root->d_inode;
898 const struct inode_security_struct *oldisec = oldinode->i_security;
899 struct inode *newinode = newsb->s_root->d_inode;
900 struct inode_security_struct *newisec = newinode->i_security;
901
902 newisec->sid = oldisec->sid;
903 }
904
905 sb_finish_set_opts(newsb);
906 mutex_unlock(&newsbsec->lock);
907 return 0;
908 }
909
910 static int selinux_parse_opts_str(char *options,
911 struct security_mnt_opts *opts)
912 {
913 char *p;
914 char *context = NULL, *defcontext = NULL;
915 char *fscontext = NULL, *rootcontext = NULL;
916 int rc, num_mnt_opts = 0;
917
918 opts->num_mnt_opts = 0;
919
920 /* Standard string-based options. */
921 while ((p = strsep(&options, "|")) != NULL) {
922 int token;
923 substring_t args[MAX_OPT_ARGS];
924
925 if (!*p)
926 continue;
927
928 token = match_token(p, tokens, args);
929
930 switch (token) {
931 case Opt_context:
932 if (context || defcontext) {
933 rc = -EINVAL;
934 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
935 goto out_err;
936 }
937 context = match_strdup(&args[0]);
938 if (!context) {
939 rc = -ENOMEM;
940 goto out_err;
941 }
942 break;
943
944 case Opt_fscontext:
945 if (fscontext) {
946 rc = -EINVAL;
947 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
948 goto out_err;
949 }
950 fscontext = match_strdup(&args[0]);
951 if (!fscontext) {
952 rc = -ENOMEM;
953 goto out_err;
954 }
955 break;
956
957 case Opt_rootcontext:
958 if (rootcontext) {
959 rc = -EINVAL;
960 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
961 goto out_err;
962 }
963 rootcontext = match_strdup(&args[0]);
964 if (!rootcontext) {
965 rc = -ENOMEM;
966 goto out_err;
967 }
968 break;
969
970 case Opt_defcontext:
971 if (context || defcontext) {
972 rc = -EINVAL;
973 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
974 goto out_err;
975 }
976 defcontext = match_strdup(&args[0]);
977 if (!defcontext) {
978 rc = -ENOMEM;
979 goto out_err;
980 }
981 break;
982 case Opt_labelsupport:
983 break;
984 default:
985 rc = -EINVAL;
986 printk(KERN_WARNING "SELinux: unknown mount option\n");
987 goto out_err;
988
989 }
990 }
991
992 rc = -ENOMEM;
993 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
994 if (!opts->mnt_opts)
995 goto out_err;
996
997 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
998 if (!opts->mnt_opts_flags) {
999 kfree(opts->mnt_opts);
1000 goto out_err;
1001 }
1002
1003 if (fscontext) {
1004 opts->mnt_opts[num_mnt_opts] = fscontext;
1005 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
1006 }
1007 if (context) {
1008 opts->mnt_opts[num_mnt_opts] = context;
1009 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
1010 }
1011 if (rootcontext) {
1012 opts->mnt_opts[num_mnt_opts] = rootcontext;
1013 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
1014 }
1015 if (defcontext) {
1016 opts->mnt_opts[num_mnt_opts] = defcontext;
1017 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
1018 }
1019
1020 opts->num_mnt_opts = num_mnt_opts;
1021 return 0;
1022
1023 out_err:
1024 kfree(context);
1025 kfree(defcontext);
1026 kfree(fscontext);
1027 kfree(rootcontext);
1028 return rc;
1029 }
1030 /*
1031 * string mount options parsing and call set the sbsec
1032 */
1033 static int superblock_doinit(struct super_block *sb, void *data)
1034 {
1035 int rc = 0;
1036 char *options = data;
1037 struct security_mnt_opts opts;
1038
1039 security_init_mnt_opts(&opts);
1040
1041 if (!data)
1042 goto out;
1043
1044 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
1045
1046 rc = selinux_parse_opts_str(options, &opts);
1047 if (rc)
1048 goto out_err;
1049
1050 out:
1051 rc = selinux_set_mnt_opts(sb, &opts, 0, NULL);
1052
1053 out_err:
1054 security_free_mnt_opts(&opts);
1055 return rc;
1056 }
1057
1058 static void selinux_write_opts(struct seq_file *m,
1059 struct security_mnt_opts *opts)
1060 {
1061 int i;
1062 char *prefix;
1063
1064 for (i = 0; i < opts->num_mnt_opts; i++) {
1065 char *has_comma;
1066
1067 if (opts->mnt_opts[i])
1068 has_comma = strchr(opts->mnt_opts[i], ',');
1069 else
1070 has_comma = NULL;
1071
1072 switch (opts->mnt_opts_flags[i]) {
1073 case CONTEXT_MNT:
1074 prefix = CONTEXT_STR;
1075 break;
1076 case FSCONTEXT_MNT:
1077 prefix = FSCONTEXT_STR;
1078 break;
1079 case ROOTCONTEXT_MNT:
1080 prefix = ROOTCONTEXT_STR;
1081 break;
1082 case DEFCONTEXT_MNT:
1083 prefix = DEFCONTEXT_STR;
1084 break;
1085 case SBLABEL_MNT:
1086 seq_putc(m, ',');
1087 seq_puts(m, LABELSUPP_STR);
1088 continue;
1089 default:
1090 BUG();
1091 return;
1092 };
1093 /* we need a comma before each option */
1094 seq_putc(m, ',');
1095 seq_puts(m, prefix);
1096 if (has_comma)
1097 seq_putc(m, '\"');
1098 seq_puts(m, opts->mnt_opts[i]);
1099 if (has_comma)
1100 seq_putc(m, '\"');
1101 }
1102 }
1103
1104 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1105 {
1106 struct security_mnt_opts opts;
1107 int rc;
1108
1109 rc = selinux_get_mnt_opts(sb, &opts);
1110 if (rc) {
1111 /* before policy load we may get EINVAL, don't show anything */
1112 if (rc == -EINVAL)
1113 rc = 0;
1114 return rc;
1115 }
1116
1117 selinux_write_opts(m, &opts);
1118
1119 security_free_mnt_opts(&opts);
1120
1121 return rc;
1122 }
1123
1124 static inline u16 inode_mode_to_security_class(umode_t mode)
1125 {
1126 switch (mode & S_IFMT) {
1127 case S_IFSOCK:
1128 return SECCLASS_SOCK_FILE;
1129 case S_IFLNK:
1130 return SECCLASS_LNK_FILE;
1131 case S_IFREG:
1132 return SECCLASS_FILE;
1133 case S_IFBLK:
1134 return SECCLASS_BLK_FILE;
1135 case S_IFDIR:
1136 return SECCLASS_DIR;
1137 case S_IFCHR:
1138 return SECCLASS_CHR_FILE;
1139 case S_IFIFO:
1140 return SECCLASS_FIFO_FILE;
1141
1142 }
1143
1144 return SECCLASS_FILE;
1145 }
1146
1147 static inline int default_protocol_stream(int protocol)
1148 {
1149 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1150 }
1151
1152 static inline int default_protocol_dgram(int protocol)
1153 {
1154 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1155 }
1156
1157 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1158 {
1159 switch (family) {
1160 case PF_UNIX:
1161 switch (type) {
1162 case SOCK_STREAM:
1163 case SOCK_SEQPACKET:
1164 return SECCLASS_UNIX_STREAM_SOCKET;
1165 case SOCK_DGRAM:
1166 return SECCLASS_UNIX_DGRAM_SOCKET;
1167 }
1168 break;
1169 case PF_INET:
1170 case PF_INET6:
1171 switch (type) {
1172 case SOCK_STREAM:
1173 if (default_protocol_stream(protocol))
1174 return SECCLASS_TCP_SOCKET;
1175 else
1176 return SECCLASS_RAWIP_SOCKET;
1177 case SOCK_DGRAM:
1178 if (default_protocol_dgram(protocol))
1179 return SECCLASS_UDP_SOCKET;
1180 else
1181 return SECCLASS_RAWIP_SOCKET;
1182 case SOCK_DCCP:
1183 return SECCLASS_DCCP_SOCKET;
1184 default:
1185 return SECCLASS_RAWIP_SOCKET;
1186 }
1187 break;
1188 case PF_NETLINK:
1189 switch (protocol) {
1190 case NETLINK_ROUTE:
1191 return SECCLASS_NETLINK_ROUTE_SOCKET;
1192 case NETLINK_FIREWALL:
1193 return SECCLASS_NETLINK_FIREWALL_SOCKET;
1194 case NETLINK_SOCK_DIAG:
1195 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1196 case NETLINK_NFLOG:
1197 return SECCLASS_NETLINK_NFLOG_SOCKET;
1198 case NETLINK_XFRM:
1199 return SECCLASS_NETLINK_XFRM_SOCKET;
1200 case NETLINK_SELINUX:
1201 return SECCLASS_NETLINK_SELINUX_SOCKET;
1202 case NETLINK_AUDIT:
1203 return SECCLASS_NETLINK_AUDIT_SOCKET;
1204 case NETLINK_IP6_FW:
1205 return SECCLASS_NETLINK_IP6FW_SOCKET;
1206 case NETLINK_DNRTMSG:
1207 return SECCLASS_NETLINK_DNRT_SOCKET;
1208 case NETLINK_KOBJECT_UEVENT:
1209 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1210 default:
1211 return SECCLASS_NETLINK_SOCKET;
1212 }
1213 case PF_PACKET:
1214 return SECCLASS_PACKET_SOCKET;
1215 case PF_KEY:
1216 return SECCLASS_KEY_SOCKET;
1217 case PF_APPLETALK:
1218 return SECCLASS_APPLETALK_SOCKET;
1219 }
1220
1221 return SECCLASS_SOCKET;
1222 }
1223
1224 #ifdef CONFIG_PROC_FS
1225 static int selinux_proc_get_sid(struct dentry *dentry,
1226 u16 tclass,
1227 u32 *sid)
1228 {
1229 int rc;
1230 char *buffer, *path;
1231
1232 buffer = (char *)__get_free_page(GFP_KERNEL);
1233 if (!buffer)
1234 return -ENOMEM;
1235
1236 path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1237 if (IS_ERR(path))
1238 rc = PTR_ERR(path);
1239 else {
1240 /* each process gets a /proc/PID/ entry. Strip off the
1241 * PID part to get a valid selinux labeling.
1242 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1243 while (path[1] >= '0' && path[1] <= '9') {
1244 path[1] = '/';
1245 path++;
1246 }
1247 rc = security_genfs_sid("proc", path, tclass, sid);
1248 }
1249 free_page((unsigned long)buffer);
1250 return rc;
1251 }
1252 #else
1253 static int selinux_proc_get_sid(struct dentry *dentry,
1254 u16 tclass,
1255 u32 *sid)
1256 {
1257 return -EINVAL;
1258 }
1259 #endif
1260
1261 /* The inode's security attributes must be initialized before first use. */
1262 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1263 {
1264 struct superblock_security_struct *sbsec = NULL;
1265 struct inode_security_struct *isec = inode->i_security;
1266 u32 sid;
1267 struct dentry *dentry;
1268 #define INITCONTEXTLEN 255
1269 char *context = NULL;
1270 unsigned len = 0;
1271 int rc = 0;
1272
1273 if (isec->initialized)
1274 goto out;
1275
1276 mutex_lock(&isec->lock);
1277 if (isec->initialized)
1278 goto out_unlock;
1279
1280 sbsec = inode->i_sb->s_security;
1281 if (!(sbsec->flags & SE_SBINITIALIZED)) {
1282 /* Defer initialization until selinux_complete_init,
1283 after the initial policy is loaded and the security
1284 server is ready to handle calls. */
1285 spin_lock(&sbsec->isec_lock);
1286 if (list_empty(&isec->list))
1287 list_add(&isec->list, &sbsec->isec_head);
1288 spin_unlock(&sbsec->isec_lock);
1289 goto out_unlock;
1290 }
1291
1292 switch (sbsec->behavior) {
1293 case SECURITY_FS_USE_NATIVE:
1294 break;
1295 case SECURITY_FS_USE_XATTR:
1296 if (!inode->i_op->getxattr) {
1297 isec->sid = sbsec->def_sid;
1298 break;
1299 }
1300
1301 /* Need a dentry, since the xattr API requires one.
1302 Life would be simpler if we could just pass the inode. */
1303 if (opt_dentry) {
1304 /* Called from d_instantiate or d_splice_alias. */
1305 dentry = dget(opt_dentry);
1306 } else {
1307 /* Called from selinux_complete_init, try to find a dentry. */
1308 dentry = d_find_alias(inode);
1309 }
1310 if (!dentry) {
1311 /*
1312 * this is can be hit on boot when a file is accessed
1313 * before the policy is loaded. When we load policy we
1314 * may find inodes that have no dentry on the
1315 * sbsec->isec_head list. No reason to complain as these
1316 * will get fixed up the next time we go through
1317 * inode_doinit with a dentry, before these inodes could
1318 * be used again by userspace.
1319 */
1320 goto out_unlock;
1321 }
1322
1323 len = INITCONTEXTLEN;
1324 context = kmalloc(len+1, GFP_NOFS);
1325 if (!context) {
1326 rc = -ENOMEM;
1327 dput(dentry);
1328 goto out_unlock;
1329 }
1330 context[len] = '\0';
1331 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1332 context, len);
1333 if (rc == -ERANGE) {
1334 kfree(context);
1335
1336 /* Need a larger buffer. Query for the right size. */
1337 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1338 NULL, 0);
1339 if (rc < 0) {
1340 dput(dentry);
1341 goto out_unlock;
1342 }
1343 len = rc;
1344 context = kmalloc(len+1, GFP_NOFS);
1345 if (!context) {
1346 rc = -ENOMEM;
1347 dput(dentry);
1348 goto out_unlock;
1349 }
1350 context[len] = '\0';
1351 rc = inode->i_op->getxattr(dentry,
1352 XATTR_NAME_SELINUX,
1353 context, len);
1354 }
1355 dput(dentry);
1356 if (rc < 0) {
1357 if (rc != -ENODATA) {
1358 printk(KERN_WARNING "SELinux: %s: getxattr returned "
1359 "%d for dev=%s ino=%ld\n", __func__,
1360 -rc, inode->i_sb->s_id, inode->i_ino);
1361 kfree(context);
1362 goto out_unlock;
1363 }
1364 /* Map ENODATA to the default file SID */
1365 sid = sbsec->def_sid;
1366 rc = 0;
1367 } else {
1368 rc = security_context_to_sid_default(context, rc, &sid,
1369 sbsec->def_sid,
1370 GFP_NOFS);
1371 if (rc) {
1372 char *dev = inode->i_sb->s_id;
1373 unsigned long ino = inode->i_ino;
1374
1375 if (rc == -EINVAL) {
1376 if (printk_ratelimit())
1377 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
1378 "context=%s. This indicates you may need to relabel the inode or the "
1379 "filesystem in question.\n", ino, dev, context);
1380 } else {
1381 printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) "
1382 "returned %d for dev=%s ino=%ld\n",
1383 __func__, context, -rc, dev, ino);
1384 }
1385 kfree(context);
1386 /* Leave with the unlabeled SID */
1387 rc = 0;
1388 break;
1389 }
1390 }
1391 kfree(context);
1392 isec->sid = sid;
1393 break;
1394 case SECURITY_FS_USE_TASK:
1395 isec->sid = isec->task_sid;
1396 break;
1397 case SECURITY_FS_USE_TRANS:
1398 /* Default to the fs SID. */
1399 isec->sid = sbsec->sid;
1400
1401 /* Try to obtain a transition SID. */
1402 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1403 rc = security_transition_sid(isec->task_sid, sbsec->sid,
1404 isec->sclass, NULL, &sid);
1405 if (rc)
1406 goto out_unlock;
1407 isec->sid = sid;
1408 break;
1409 case SECURITY_FS_USE_MNTPOINT:
1410 isec->sid = sbsec->mntpoint_sid;
1411 break;
1412 default:
1413 /* Default to the fs superblock SID. */
1414 isec->sid = sbsec->sid;
1415
1416 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
1417 /* We must have a dentry to determine the label on
1418 * procfs inodes */
1419 if (opt_dentry)
1420 /* Called from d_instantiate or
1421 * d_splice_alias. */
1422 dentry = dget(opt_dentry);
1423 else
1424 /* Called from selinux_complete_init, try to
1425 * find a dentry. */
1426 dentry = d_find_alias(inode);
1427 /*
1428 * This can be hit on boot when a file is accessed
1429 * before the policy is loaded. When we load policy we
1430 * may find inodes that have no dentry on the
1431 * sbsec->isec_head list. No reason to complain as
1432 * these will get fixed up the next time we go through
1433 * inode_doinit() with a dentry, before these inodes
1434 * could be used again by userspace.
1435 */
1436 if (!dentry)
1437 goto out_unlock;
1438 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1439 rc = selinux_proc_get_sid(dentry, isec->sclass, &sid);
1440 dput(dentry);
1441 if (rc)
1442 goto out_unlock;
1443 isec->sid = sid;
1444 }
1445 break;
1446 }
1447
1448 isec->initialized = 1;
1449
1450 out_unlock:
1451 mutex_unlock(&isec->lock);
1452 out:
1453 if (isec->sclass == SECCLASS_FILE)
1454 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1455 return rc;
1456 }
1457
1458 /* Convert a Linux signal to an access vector. */
1459 static inline u32 signal_to_av(int sig)
1460 {
1461 u32 perm = 0;
1462
1463 switch (sig) {
1464 case SIGCHLD:
1465 /* Commonly granted from child to parent. */
1466 perm = PROCESS__SIGCHLD;
1467 break;
1468 case SIGKILL:
1469 /* Cannot be caught or ignored */
1470 perm = PROCESS__SIGKILL;
1471 break;
1472 case SIGSTOP:
1473 /* Cannot be caught or ignored */
1474 perm = PROCESS__SIGSTOP;
1475 break;
1476 default:
1477 /* All other signals. */
1478 perm = PROCESS__SIGNAL;
1479 break;
1480 }
1481
1482 return perm;
1483 }
1484
1485 /*
1486 * Check permission between a pair of credentials
1487 * fork check, ptrace check, etc.
1488 */
1489 static int cred_has_perm(const struct cred *actor,
1490 const struct cred *target,
1491 u32 perms)
1492 {
1493 u32 asid = cred_sid(actor), tsid = cred_sid(target);
1494
1495 return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1496 }
1497
1498 /*
1499 * Check permission between a pair of tasks, e.g. signal checks,
1500 * fork check, ptrace check, etc.
1501 * tsk1 is the actor and tsk2 is the target
1502 * - this uses the default subjective creds of tsk1
1503 */
1504 static int task_has_perm(const struct task_struct *tsk1,
1505 const struct task_struct *tsk2,
1506 u32 perms)
1507 {
1508 const struct task_security_struct *__tsec1, *__tsec2;
1509 u32 sid1, sid2;
1510
1511 rcu_read_lock();
1512 __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid;
1513 __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid;
1514 rcu_read_unlock();
1515 return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1516 }
1517
1518 /*
1519 * Check permission between current and another task, e.g. signal checks,
1520 * fork check, ptrace check, etc.
1521 * current is the actor and tsk2 is the target
1522 * - this uses current's subjective creds
1523 */
1524 static int current_has_perm(const struct task_struct *tsk,
1525 u32 perms)
1526 {
1527 u32 sid, tsid;
1528
1529 sid = current_sid();
1530 tsid = task_sid(tsk);
1531 return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1532 }
1533
1534 #if CAP_LAST_CAP > 63
1535 #error Fix SELinux to handle capabilities > 63.
1536 #endif
1537
1538 /* Check whether a task is allowed to use a capability. */
1539 static int cred_has_capability(const struct cred *cred,
1540 int cap, int audit)
1541 {
1542 struct common_audit_data ad;
1543 struct av_decision avd;
1544 u16 sclass;
1545 u32 sid = cred_sid(cred);
1546 u32 av = CAP_TO_MASK(cap);
1547 int rc;
1548
1549 ad.type = LSM_AUDIT_DATA_CAP;
1550 ad.u.cap = cap;
1551
1552 switch (CAP_TO_INDEX(cap)) {
1553 case 0:
1554 sclass = SECCLASS_CAPABILITY;
1555 break;
1556 case 1:
1557 sclass = SECCLASS_CAPABILITY2;
1558 break;
1559 default:
1560 printk(KERN_ERR
1561 "SELinux: out of range capability %d\n", cap);
1562 BUG();
1563 return -EINVAL;
1564 }
1565
1566 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1567 if (audit == SECURITY_CAP_AUDIT) {
1568 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1569 if (rc2)
1570 return rc2;
1571 }
1572 return rc;
1573 }
1574
1575 /* Check whether a task is allowed to use a system operation. */
1576 static int task_has_system(struct task_struct *tsk,
1577 u32 perms)
1578 {
1579 u32 sid = task_sid(tsk);
1580
1581 return avc_has_perm(sid, SECINITSID_KERNEL,
1582 SECCLASS_SYSTEM, perms, NULL);
1583 }
1584
1585 /* Check whether a task has a particular permission to an inode.
1586 The 'adp' parameter is optional and allows other audit
1587 data to be passed (e.g. the dentry). */
1588 static int inode_has_perm(const struct cred *cred,
1589 struct inode *inode,
1590 u32 perms,
1591 struct common_audit_data *adp)
1592 {
1593 struct inode_security_struct *isec;
1594 u32 sid;
1595
1596 validate_creds(cred);
1597
1598 if (unlikely(IS_PRIVATE(inode)))
1599 return 0;
1600
1601 sid = cred_sid(cred);
1602 isec = inode->i_security;
1603
1604 return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1605 }
1606
1607 /* Same as inode_has_perm, but pass explicit audit data containing
1608 the dentry to help the auditing code to more easily generate the
1609 pathname if needed. */
1610 static inline int dentry_has_perm(const struct cred *cred,
1611 struct dentry *dentry,
1612 u32 av)
1613 {
1614 struct inode *inode = dentry->d_inode;
1615 struct common_audit_data ad;
1616
1617 ad.type = LSM_AUDIT_DATA_DENTRY;
1618 ad.u.dentry = dentry;
1619 return inode_has_perm(cred, inode, av, &ad);
1620 }
1621
1622 /* Same as inode_has_perm, but pass explicit audit data containing
1623 the path to help the auditing code to more easily generate the
1624 pathname if needed. */
1625 static inline int path_has_perm(const struct cred *cred,
1626 const struct path *path,
1627 u32 av)
1628 {
1629 struct inode *inode = path->dentry->d_inode;
1630 struct common_audit_data ad;
1631
1632 ad.type = LSM_AUDIT_DATA_PATH;
1633 ad.u.path = *path;
1634 return inode_has_perm(cred, inode, av, &ad);
1635 }
1636
1637 /* Same as path_has_perm, but uses the inode from the file struct. */
1638 static inline int file_path_has_perm(const struct cred *cred,
1639 struct file *file,
1640 u32 av)
1641 {
1642 struct common_audit_data ad;
1643
1644 ad.type = LSM_AUDIT_DATA_PATH;
1645 ad.u.path = file->f_path;
1646 return inode_has_perm(cred, file_inode(file), av, &ad);
1647 }
1648
1649 /* Check whether a task can use an open file descriptor to
1650 access an inode in a given way. Check access to the
1651 descriptor itself, and then use dentry_has_perm to
1652 check a particular permission to the file.
1653 Access to the descriptor is implicitly granted if it
1654 has the same SID as the process. If av is zero, then
1655 access to the file is not checked, e.g. for cases
1656 where only the descriptor is affected like seek. */
1657 static int file_has_perm(const struct cred *cred,
1658 struct file *file,
1659 u32 av)
1660 {
1661 struct file_security_struct *fsec = file->f_security;
1662 struct inode *inode = file_inode(file);
1663 struct common_audit_data ad;
1664 u32 sid = cred_sid(cred);
1665 int rc;
1666
1667 ad.type = LSM_AUDIT_DATA_PATH;
1668 ad.u.path = file->f_path;
1669
1670 if (sid != fsec->sid) {
1671 rc = avc_has_perm(sid, fsec->sid,
1672 SECCLASS_FD,
1673 FD__USE,
1674 &ad);
1675 if (rc)
1676 goto out;
1677 }
1678
1679 /* av is zero if only checking access to the descriptor. */
1680 rc = 0;
1681 if (av)
1682 rc = inode_has_perm(cred, inode, av, &ad);
1683
1684 out:
1685 return rc;
1686 }
1687
1688 /* Check whether a task can create a file. */
1689 static int may_create(struct inode *dir,
1690 struct dentry *dentry,
1691 u16 tclass)
1692 {
1693 const struct task_security_struct *tsec = current_security();
1694 struct inode_security_struct *dsec;
1695 struct superblock_security_struct *sbsec;
1696 u32 sid, newsid;
1697 struct common_audit_data ad;
1698 int rc;
1699
1700 dsec = dir->i_security;
1701 sbsec = dir->i_sb->s_security;
1702
1703 sid = tsec->sid;
1704 newsid = tsec->create_sid;
1705
1706 ad.type = LSM_AUDIT_DATA_DENTRY;
1707 ad.u.dentry = dentry;
1708
1709 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1710 DIR__ADD_NAME | DIR__SEARCH,
1711 &ad);
1712 if (rc)
1713 return rc;
1714
1715 if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
1716 rc = security_transition_sid(sid, dsec->sid, tclass,
1717 &dentry->d_name, &newsid);
1718 if (rc)
1719 return rc;
1720 }
1721
1722 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1723 if (rc)
1724 return rc;
1725
1726 return avc_has_perm(newsid, sbsec->sid,
1727 SECCLASS_FILESYSTEM,
1728 FILESYSTEM__ASSOCIATE, &ad);
1729 }
1730
1731 /* Check whether a task can create a key. */
1732 static int may_create_key(u32 ksid,
1733 struct task_struct *ctx)
1734 {
1735 u32 sid = task_sid(ctx);
1736
1737 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1738 }
1739
1740 #define MAY_LINK 0
1741 #define MAY_UNLINK 1
1742 #define MAY_RMDIR 2
1743
1744 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1745 static int may_link(struct inode *dir,
1746 struct dentry *dentry,
1747 int kind)
1748
1749 {
1750 struct inode_security_struct *dsec, *isec;
1751 struct common_audit_data ad;
1752 u32 sid = current_sid();
1753 u32 av;
1754 int rc;
1755
1756 dsec = dir->i_security;
1757 isec = dentry->d_inode->i_security;
1758
1759 ad.type = LSM_AUDIT_DATA_DENTRY;
1760 ad.u.dentry = dentry;
1761
1762 av = DIR__SEARCH;
1763 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1764 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1765 if (rc)
1766 return rc;
1767
1768 switch (kind) {
1769 case MAY_LINK:
1770 av = FILE__LINK;
1771 break;
1772 case MAY_UNLINK:
1773 av = FILE__UNLINK;
1774 break;
1775 case MAY_RMDIR:
1776 av = DIR__RMDIR;
1777 break;
1778 default:
1779 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n",
1780 __func__, kind);
1781 return 0;
1782 }
1783
1784 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1785 return rc;
1786 }
1787
1788 static inline int may_rename(struct inode *old_dir,
1789 struct dentry *old_dentry,
1790 struct inode *new_dir,
1791 struct dentry *new_dentry)
1792 {
1793 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1794 struct common_audit_data ad;
1795 u32 sid = current_sid();
1796 u32 av;
1797 int old_is_dir, new_is_dir;
1798 int rc;
1799
1800 old_dsec = old_dir->i_security;
1801 old_isec = old_dentry->d_inode->i_security;
1802 old_is_dir = d_is_dir(old_dentry);
1803 new_dsec = new_dir->i_security;
1804
1805 ad.type = LSM_AUDIT_DATA_DENTRY;
1806
1807 ad.u.dentry = old_dentry;
1808 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1809 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1810 if (rc)
1811 return rc;
1812 rc = avc_has_perm(sid, old_isec->sid,
1813 old_isec->sclass, FILE__RENAME, &ad);
1814 if (rc)
1815 return rc;
1816 if (old_is_dir && new_dir != old_dir) {
1817 rc = avc_has_perm(sid, old_isec->sid,
1818 old_isec->sclass, DIR__REPARENT, &ad);
1819 if (rc)
1820 return rc;
1821 }
1822
1823 ad.u.dentry = new_dentry;
1824 av = DIR__ADD_NAME | DIR__SEARCH;
1825 if (d_is_positive(new_dentry))
1826 av |= DIR__REMOVE_NAME;
1827 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1828 if (rc)
1829 return rc;
1830 if (d_is_positive(new_dentry)) {
1831 new_isec = new_dentry->d_inode->i_security;
1832 new_is_dir = d_is_dir(new_dentry);
1833 rc = avc_has_perm(sid, new_isec->sid,
1834 new_isec->sclass,
1835 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1836 if (rc)
1837 return rc;
1838 }
1839
1840 return 0;
1841 }
1842
1843 /* Check whether a task can perform a filesystem operation. */
1844 static int superblock_has_perm(const struct cred *cred,
1845 struct super_block *sb,
1846 u32 perms,
1847 struct common_audit_data *ad)
1848 {
1849 struct superblock_security_struct *sbsec;
1850 u32 sid = cred_sid(cred);
1851
1852 sbsec = sb->s_security;
1853 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1854 }
1855
1856 /* Convert a Linux mode and permission mask to an access vector. */
1857 static inline u32 file_mask_to_av(int mode, int mask)
1858 {
1859 u32 av = 0;
1860
1861 if (!S_ISDIR(mode)) {
1862 if (mask & MAY_EXEC)
1863 av |= FILE__EXECUTE;
1864 if (mask & MAY_READ)
1865 av |= FILE__READ;
1866
1867 if (mask & MAY_APPEND)
1868 av |= FILE__APPEND;
1869 else if (mask & MAY_WRITE)
1870 av |= FILE__WRITE;
1871
1872 } else {
1873 if (mask & MAY_EXEC)
1874 av |= DIR__SEARCH;
1875 if (mask & MAY_WRITE)
1876 av |= DIR__WRITE;
1877 if (mask & MAY_READ)
1878 av |= DIR__READ;
1879 }
1880
1881 return av;
1882 }
1883
1884 /* Convert a Linux file to an access vector. */
1885 static inline u32 file_to_av(struct file *file)
1886 {
1887 u32 av = 0;
1888
1889 if (file->f_mode & FMODE_READ)
1890 av |= FILE__READ;
1891 if (file->f_mode & FMODE_WRITE) {
1892 if (file->f_flags & O_APPEND)
1893 av |= FILE__APPEND;
1894 else
1895 av |= FILE__WRITE;
1896 }
1897 if (!av) {
1898 /*
1899 * Special file opened with flags 3 for ioctl-only use.
1900 */
1901 av = FILE__IOCTL;
1902 }
1903
1904 return av;
1905 }
1906
1907 /*
1908 * Convert a file to an access vector and include the correct open
1909 * open permission.
1910 */
1911 static inline u32 open_file_to_av(struct file *file)
1912 {
1913 u32 av = file_to_av(file);
1914
1915 if (selinux_policycap_openperm)
1916 av |= FILE__OPEN;
1917
1918 return av;
1919 }
1920
1921 /* Hook functions begin here. */
1922
1923 static int selinux_binder_set_context_mgr(struct task_struct *mgr)
1924 {
1925 u32 mysid = current_sid();
1926 u32 mgrsid = task_sid(mgr);
1927
1928 return avc_has_perm(mysid, mgrsid, SECCLASS_BINDER,
1929 BINDER__SET_CONTEXT_MGR, NULL);
1930 }
1931
1932 static int selinux_binder_transaction(struct task_struct *from,
1933 struct task_struct *to)
1934 {
1935 u32 mysid = current_sid();
1936 u32 fromsid = task_sid(from);
1937 u32 tosid = task_sid(to);
1938 int rc;
1939
1940 if (mysid != fromsid) {
1941 rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER,
1942 BINDER__IMPERSONATE, NULL);
1943 if (rc)
1944 return rc;
1945 }
1946
1947 return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__CALL,
1948 NULL);
1949 }
1950
1951 static int selinux_binder_transfer_binder(struct task_struct *from,
1952 struct task_struct *to)
1953 {
1954 u32 fromsid = task_sid(from);
1955 u32 tosid = task_sid(to);
1956
1957 return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER,
1958 NULL);
1959 }
1960
1961 static int selinux_binder_transfer_file(struct task_struct *from,
1962 struct task_struct *to,
1963 struct file *file)
1964 {
1965 u32 sid = task_sid(to);
1966 struct file_security_struct *fsec = file->f_security;
1967 struct inode *inode = file->f_path.dentry->d_inode;
1968 struct inode_security_struct *isec = inode->i_security;
1969 struct common_audit_data ad;
1970 int rc;
1971
1972 ad.type = LSM_AUDIT_DATA_PATH;
1973 ad.u.path = file->f_path;
1974
1975 if (sid != fsec->sid) {
1976 rc = avc_has_perm(sid, fsec->sid,
1977 SECCLASS_FD,
1978 FD__USE,
1979 &ad);
1980 if (rc)
1981 return rc;
1982 }
1983
1984 if (unlikely(IS_PRIVATE(inode)))
1985 return 0;
1986
1987 return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
1988 &ad);
1989 }
1990
1991 static int selinux_ptrace_access_check(struct task_struct *child,
1992 unsigned int mode)
1993 {
1994 int rc;
1995
1996 rc = cap_ptrace_access_check(child, mode);
1997 if (rc)
1998 return rc;
1999
2000 if (mode & PTRACE_MODE_READ) {
2001 u32 sid = current_sid();
2002 u32 csid = task_sid(child);
2003 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
2004 }
2005
2006 return current_has_perm(child, PROCESS__PTRACE);
2007 }
2008
2009 static int selinux_ptrace_traceme(struct task_struct *parent)
2010 {
2011 int rc;
2012
2013 rc = cap_ptrace_traceme(parent);
2014 if (rc)
2015 return rc;
2016
2017 return task_has_perm(parent, current, PROCESS__PTRACE);
2018 }
2019
2020 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
2021 kernel_cap_t *inheritable, kernel_cap_t *permitted)
2022 {
2023 int error;
2024
2025 error = current_has_perm(target, PROCESS__GETCAP);
2026 if (error)
2027 return error;
2028
2029 return cap_capget(target, effective, inheritable, permitted);
2030 }
2031
2032 static int selinux_capset(struct cred *new, const struct cred *old,
2033 const kernel_cap_t *effective,
2034 const kernel_cap_t *inheritable,
2035 const kernel_cap_t *permitted)
2036 {
2037 int error;
2038
2039 error = cap_capset(new, old,
2040 effective, inheritable, permitted);
2041 if (error)
2042 return error;
2043
2044 return cred_has_perm(old, new, PROCESS__SETCAP);
2045 }
2046
2047 /*
2048 * (This comment used to live with the selinux_task_setuid hook,
2049 * which was removed).
2050 *
2051 * Since setuid only affects the current process, and since the SELinux
2052 * controls are not based on the Linux identity attributes, SELinux does not
2053 * need to control this operation. However, SELinux does control the use of
2054 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
2055 */
2056
2057 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
2058 int cap, int audit)
2059 {
2060 int rc;
2061
2062 rc = cap_capable(cred, ns, cap, audit);
2063 if (rc)
2064 return rc;
2065
2066 return cred_has_capability(cred, cap, audit);
2067 }
2068
2069 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
2070 {
2071 const struct cred *cred = current_cred();
2072 int rc = 0;
2073
2074 if (!sb)
2075 return 0;
2076
2077 switch (cmds) {
2078 case Q_SYNC:
2079 case Q_QUOTAON:
2080 case Q_QUOTAOFF:
2081 case Q_SETINFO:
2082 case Q_SETQUOTA:
2083 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2084 break;
2085 case Q_GETFMT:
2086 case Q_GETINFO:
2087 case Q_GETQUOTA:
2088 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2089 break;
2090 default:
2091 rc = 0; /* let the kernel handle invalid cmds */
2092 break;
2093 }
2094 return rc;
2095 }
2096
2097 static int selinux_quota_on(struct dentry *dentry)
2098 {
2099 const struct cred *cred = current_cred();
2100
2101 return dentry_has_perm(cred, dentry, FILE__QUOTAON);
2102 }
2103
2104 static int selinux_syslog(int type)
2105 {
2106 int rc;
2107
2108 switch (type) {
2109 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
2110 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
2111 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
2112 break;
2113 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
2114 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */
2115 /* Set level of messages printed to console */
2116 case SYSLOG_ACTION_CONSOLE_LEVEL:
2117 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
2118 break;
2119 case SYSLOG_ACTION_CLOSE: /* Close log */
2120 case SYSLOG_ACTION_OPEN: /* Open log */
2121 case SYSLOG_ACTION_READ: /* Read from log */
2122 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */
2123 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */
2124 default:
2125 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
2126 break;
2127 }
2128 return rc;
2129 }
2130
2131 /*
2132 * Check that a process has enough memory to allocate a new virtual
2133 * mapping. 0 means there is enough memory for the allocation to
2134 * succeed and -ENOMEM implies there is not.
2135 *
2136 * Do not audit the selinux permission check, as this is applied to all
2137 * processes that allocate mappings.
2138 */
2139 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2140 {
2141 int rc, cap_sys_admin = 0;
2142
2143 rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
2144 SECURITY_CAP_NOAUDIT);
2145 if (rc == 0)
2146 cap_sys_admin = 1;
2147
2148 return __vm_enough_memory(mm, pages, cap_sys_admin);
2149 }
2150
2151 /* binprm security operations */
2152
2153 static int check_nnp_nosuid(const struct linux_binprm *bprm,
2154 const struct task_security_struct *old_tsec,
2155 const struct task_security_struct *new_tsec)
2156 {
2157 int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2158 int nosuid = (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID);
2159 int rc;
2160
2161 if (!nnp && !nosuid)
2162 return 0; /* neither NNP nor nosuid */
2163
2164 if (new_tsec->sid == old_tsec->sid)
2165 return 0; /* No change in credentials */
2166
2167 /*
2168 * The only transitions we permit under NNP or nosuid
2169 * are transitions to bounded SIDs, i.e. SIDs that are
2170 * guaranteed to only be allowed a subset of the permissions
2171 * of the current SID.
2172 */
2173 rc = security_bounded_transition(old_tsec->sid, new_tsec->sid);
2174 if (rc) {
2175 /*
2176 * On failure, preserve the errno values for NNP vs nosuid.
2177 * NNP: Operation not permitted for caller.
2178 * nosuid: Permission denied to file.
2179 */
2180 if (nnp)
2181 return -EPERM;
2182 else
2183 return -EACCES;
2184 }
2185 return 0;
2186 }
2187
2188 static int selinux_bprm_set_creds(struct linux_binprm *bprm)
2189 {
2190 const struct task_security_struct *old_tsec;
2191 struct task_security_struct *new_tsec;
2192 struct inode_security_struct *isec;
2193 struct common_audit_data ad;
2194 struct inode *inode = file_inode(bprm->file);
2195 int rc;
2196
2197 rc = cap_bprm_set_creds(bprm);
2198 if (rc)
2199 return rc;
2200
2201 /* SELinux context only depends on initial program or script and not
2202 * the script interpreter */
2203 if (bprm->cred_prepared)
2204 return 0;
2205
2206 old_tsec = current_security();
2207 new_tsec = bprm->cred->security;
2208 isec = inode->i_security;
2209
2210 /* Default to the current task SID. */
2211 new_tsec->sid = old_tsec->sid;
2212 new_tsec->osid = old_tsec->sid;
2213
2214 /* Reset fs, key, and sock SIDs on execve. */
2215 new_tsec->create_sid = 0;
2216 new_tsec->keycreate_sid = 0;
2217 new_tsec->sockcreate_sid = 0;
2218
2219 if (old_tsec->exec_sid) {
2220 new_tsec->sid = old_tsec->exec_sid;
2221 /* Reset exec SID on execve. */
2222 new_tsec->exec_sid = 0;
2223
2224 /* Fail on NNP or nosuid if not an allowed transition. */
2225 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2226 if (rc)
2227 return rc;
2228 } else {
2229 /* Check for a default transition on this program. */
2230 rc = security_transition_sid(old_tsec->sid, isec->sid,
2231 SECCLASS_PROCESS, NULL,
2232 &new_tsec->sid);
2233 if (rc)
2234 return rc;
2235
2236 /*
2237 * Fallback to old SID on NNP or nosuid if not an allowed
2238 * transition.
2239 */
2240 rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2241 if (rc)
2242 new_tsec->sid = old_tsec->sid;
2243 }
2244
2245 ad.type = LSM_AUDIT_DATA_PATH;
2246 ad.u.path = bprm->file->f_path;
2247
2248 if (new_tsec->sid == old_tsec->sid) {
2249 rc = avc_has_perm(old_tsec->sid, isec->sid,
2250 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2251 if (rc)
2252 return rc;
2253 } else {
2254 /* Check permissions for the transition. */
2255 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2256 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2257 if (rc)
2258 return rc;
2259
2260 rc = avc_has_perm(new_tsec->sid, isec->sid,
2261 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2262 if (rc)
2263 return rc;
2264
2265 /* Check for shared state */
2266 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2267 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2268 SECCLASS_PROCESS, PROCESS__SHARE,
2269 NULL);
2270 if (rc)
2271 return -EPERM;
2272 }
2273
2274 /* Make sure that anyone attempting to ptrace over a task that
2275 * changes its SID has the appropriate permit */
2276 if (bprm->unsafe &
2277 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2278 struct task_struct *tracer;
2279 struct task_security_struct *sec;
2280 u32 ptsid = 0;
2281
2282 rcu_read_lock();
2283 tracer = ptrace_parent(current);
2284 if (likely(tracer != NULL)) {
2285 sec = __task_cred(tracer)->security;
2286 ptsid = sec->sid;
2287 }
2288 rcu_read_unlock();
2289
2290 if (ptsid != 0) {
2291 rc = avc_has_perm(ptsid, new_tsec->sid,
2292 SECCLASS_PROCESS,
2293 PROCESS__PTRACE, NULL);
2294 if (rc)
2295 return -EPERM;
2296 }
2297 }
2298
2299 /* Clear any possibly unsafe personality bits on exec: */
2300 bprm->per_clear |= PER_CLEAR_ON_SETID;
2301 }
2302
2303 return 0;
2304 }
2305
2306 static int selinux_bprm_secureexec(struct linux_binprm *bprm)
2307 {
2308 const struct task_security_struct *tsec = current_security();
2309 u32 sid, osid;
2310 int atsecure = 0;
2311
2312 sid = tsec->sid;
2313 osid = tsec->osid;
2314
2315 if (osid != sid) {
2316 /* Enable secure mode for SIDs transitions unless
2317 the noatsecure permission is granted between
2318 the two SIDs, i.e. ahp returns 0. */
2319 atsecure = avc_has_perm(osid, sid,
2320 SECCLASS_PROCESS,
2321 PROCESS__NOATSECURE, NULL);
2322 }
2323
2324 return (atsecure || cap_bprm_secureexec(bprm));
2325 }
2326
2327 static int match_file(const void *p, struct file *file, unsigned fd)
2328 {
2329 return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
2330 }
2331
2332 /* Derived from fs/exec.c:flush_old_files. */
2333 static inline void flush_unauthorized_files(const struct cred *cred,
2334 struct files_struct *files)
2335 {
2336 struct file *file, *devnull = NULL;
2337 struct tty_struct *tty;
2338 int drop_tty = 0;
2339 unsigned n;
2340
2341 tty = get_current_tty();
2342 if (tty) {
2343 spin_lock(&tty_files_lock);
2344 if (!list_empty(&tty->tty_files)) {
2345 struct tty_file_private *file_priv;
2346
2347 /* Revalidate access to controlling tty.
2348 Use file_path_has_perm on the tty path directly
2349 rather than using file_has_perm, as this particular
2350 open file may belong to another process and we are
2351 only interested in the inode-based check here. */
2352 file_priv = list_first_entry(&tty->tty_files,
2353 struct tty_file_private, list);
2354 file = file_priv->file;
2355 if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2356 drop_tty = 1;
2357 }
2358 spin_unlock(&tty_files_lock);
2359 tty_kref_put(tty);
2360 }
2361 /* Reset controlling tty. */
2362 if (drop_tty)
2363 no_tty();
2364
2365 /* Revalidate access to inherited open files. */
2366 n = iterate_fd(files, 0, match_file, cred);
2367 if (!n) /* none found? */
2368 return;
2369
2370 devnull = dentry_open(&selinux_null, O_RDWR, cred);
2371 if (IS_ERR(devnull))
2372 devnull = NULL;
2373 /* replace all the matching ones with this */
2374 do {
2375 replace_fd(n - 1, devnull, 0);
2376 } while ((n = iterate_fd(files, n, match_file, cred)) != 0);
2377 if (devnull)
2378 fput(devnull);
2379 }
2380
2381 /*
2382 * Prepare a process for imminent new credential changes due to exec
2383 */
2384 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2385 {
2386 struct task_security_struct *new_tsec;
2387 struct rlimit *rlim, *initrlim;
2388 int rc, i;
2389
2390 new_tsec = bprm->cred->security;
2391 if (new_tsec->sid == new_tsec->osid)
2392 return;
2393
2394 /* Close files for which the new task SID is not authorized. */
2395 flush_unauthorized_files(bprm->cred, current->files);
2396
2397 /* Always clear parent death signal on SID transitions. */
2398 current->pdeath_signal = 0;
2399
2400 /* Check whether the new SID can inherit resource limits from the old
2401 * SID. If not, reset all soft limits to the lower of the current
2402 * task's hard limit and the init task's soft limit.
2403 *
2404 * Note that the setting of hard limits (even to lower them) can be
2405 * controlled by the setrlimit check. The inclusion of the init task's
2406 * soft limit into the computation is to avoid resetting soft limits
2407 * higher than the default soft limit for cases where the default is
2408 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2409 */
2410 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2411 PROCESS__RLIMITINH, NULL);
2412 if (rc) {
2413 /* protect against do_prlimit() */
2414 task_lock(current);
2415 for (i = 0; i < RLIM_NLIMITS; i++) {
2416 rlim = current->signal->rlim + i;
2417 initrlim = init_task.signal->rlim + i;
2418 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2419 }
2420 task_unlock(current);
2421 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2422 }
2423 }
2424
2425 /*
2426 * Clean up the process immediately after the installation of new credentials
2427 * due to exec
2428 */
2429 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2430 {
2431 const struct task_security_struct *tsec = current_security();
2432 struct itimerval itimer;
2433 u32 osid, sid;
2434 int rc, i;
2435
2436 osid = tsec->osid;
2437 sid = tsec->sid;
2438
2439 if (sid == osid)
2440 return;
2441
2442 /* Check whether the new SID can inherit signal state from the old SID.
2443 * If not, clear itimers to avoid subsequent signal generation and
2444 * flush and unblock signals.
2445 *
2446 * This must occur _after_ the task SID has been updated so that any
2447 * kill done after the flush will be checked against the new SID.
2448 */
2449 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2450 if (rc) {
2451 memset(&itimer, 0, sizeof itimer);
2452 for (i = 0; i < 3; i++)
2453 do_setitimer(i, &itimer, NULL);
2454 spin_lock_irq(&current->sighand->siglock);
2455 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
2456 __flush_signals(current);
2457 flush_signal_handlers(current, 1);
2458 sigemptyset(&current->blocked);
2459 }
2460 spin_unlock_irq(&current->sighand->siglock);
2461 }
2462
2463 /* Wake up the parent if it is waiting so that it can recheck
2464 * wait permission to the new task SID. */
2465 read_lock(&tasklist_lock);
2466 __wake_up_parent(current, current->real_parent);
2467 read_unlock(&tasklist_lock);
2468 }
2469
2470 /* superblock security operations */
2471
2472 static int selinux_sb_alloc_security(struct super_block *sb)
2473 {
2474 return superblock_alloc_security(sb);
2475 }
2476
2477 static void selinux_sb_free_security(struct super_block *sb)
2478 {
2479 superblock_free_security(sb);
2480 }
2481
2482 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2483 {
2484 if (plen > olen)
2485 return 0;
2486
2487 return !memcmp(prefix, option, plen);
2488 }
2489
2490 static inline int selinux_option(char *option, int len)
2491 {
2492 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2493 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2494 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2495 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2496 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
2497 }
2498
2499 static inline void take_option(char **to, char *from, int *first, int len)
2500 {
2501 if (!*first) {
2502 **to = ',';
2503 *to += 1;
2504 } else
2505 *first = 0;
2506 memcpy(*to, from, len);
2507 *to += len;
2508 }
2509
2510 static inline void take_selinux_option(char **to, char *from, int *first,
2511 int len)
2512 {
2513 int current_size = 0;
2514
2515 if (!*first) {
2516 **to = '|';
2517 *to += 1;
2518 } else
2519 *first = 0;
2520
2521 while (current_size < len) {
2522 if (*from != '"') {
2523 **to = *from;
2524 *to += 1;
2525 }
2526 from += 1;
2527 current_size += 1;
2528 }
2529 }
2530
2531 static int selinux_sb_copy_data(char *orig, char *copy)
2532 {
2533 int fnosec, fsec, rc = 0;
2534 char *in_save, *in_curr, *in_end;
2535 char *sec_curr, *nosec_save, *nosec;
2536 int open_quote = 0;
2537
2538 in_curr = orig;
2539 sec_curr = copy;
2540
2541 nosec = (char *)get_zeroed_page(GFP_KERNEL);
2542 if (!nosec) {
2543 rc = -ENOMEM;
2544 goto out;
2545 }
2546
2547 nosec_save = nosec;
2548 fnosec = fsec = 1;
2549 in_save = in_end = orig;
2550
2551 do {
2552 if (*in_end == '"')
2553 open_quote = !open_quote;
2554 if ((*in_end == ',' && open_quote == 0) ||
2555 *in_end == '\0') {
2556 int len = in_end - in_curr;
2557
2558 if (selinux_option(in_curr, len))
2559 take_selinux_option(&sec_curr, in_curr, &fsec, len);
2560 else
2561 take_option(&nosec, in_curr, &fnosec, len);
2562
2563 in_curr = in_end + 1;
2564 }
2565 } while (*in_end++);
2566
2567 strcpy(in_save, nosec_save);
2568 free_page((unsigned long)nosec_save);
2569 out:
2570 return rc;
2571 }
2572
2573 static int selinux_sb_remount(struct super_block *sb, void *data)
2574 {
2575 int rc, i, *flags;
2576 struct security_mnt_opts opts;
2577 char *secdata, **mount_options;
2578 struct superblock_security_struct *sbsec = sb->s_security;
2579
2580 if (!(sbsec->flags & SE_SBINITIALIZED))
2581 return 0;
2582
2583 if (!data)
2584 return 0;
2585
2586 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
2587 return 0;
2588
2589 security_init_mnt_opts(&opts);
2590 secdata = alloc_secdata();
2591 if (!secdata)
2592 return -ENOMEM;
2593 rc = selinux_sb_copy_data(data, secdata);
2594 if (rc)
2595 goto out_free_secdata;
2596
2597 rc = selinux_parse_opts_str(secdata, &opts);
2598 if (rc)
2599 goto out_free_secdata;
2600
2601 mount_options = opts.mnt_opts;
2602 flags = opts.mnt_opts_flags;
2603
2604 for (i = 0; i < opts.num_mnt_opts; i++) {
2605 u32 sid;
2606 size_t len;
2607
2608 if (flags[i] == SBLABEL_MNT)
2609 continue;
2610 len = strlen(mount_options[i]);
2611 rc = security_context_to_sid(mount_options[i], len, &sid,
2612 GFP_KERNEL);
2613 if (rc) {
2614 printk(KERN_WARNING "SELinux: security_context_to_sid"
2615 "(%s) failed for (dev %s, type %s) errno=%d\n",
2616 mount_options[i], sb->s_id, sb->s_type->name, rc);
2617 goto out_free_opts;
2618 }
2619 rc = -EINVAL;
2620 switch (flags[i]) {
2621 case FSCONTEXT_MNT:
2622 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
2623 goto out_bad_option;
2624 break;
2625 case CONTEXT_MNT:
2626 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
2627 goto out_bad_option;
2628 break;
2629 case ROOTCONTEXT_MNT: {
2630 struct inode_security_struct *root_isec;
2631 root_isec = sb->s_root->d_inode->i_security;
2632
2633 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
2634 goto out_bad_option;
2635 break;
2636 }
2637 case DEFCONTEXT_MNT:
2638 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
2639 goto out_bad_option;
2640 break;
2641 default:
2642 goto out_free_opts;
2643 }
2644 }
2645
2646 rc = 0;
2647 out_free_opts:
2648 security_free_mnt_opts(&opts);
2649 out_free_secdata:
2650 free_secdata(secdata);
2651 return rc;
2652 out_bad_option:
2653 printk(KERN_WARNING "SELinux: unable to change security options "
2654 "during remount (dev %s, type=%s)\n", sb->s_id,
2655 sb->s_type->name);
2656 goto out_free_opts;
2657 }
2658
2659 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
2660 {
2661 const struct cred *cred = current_cred();
2662 struct common_audit_data ad;
2663 int rc;
2664
2665 rc = superblock_doinit(sb, data);
2666 if (rc)
2667 return rc;
2668
2669 /* Allow all mounts performed by the kernel */
2670 if (flags & MS_KERNMOUNT)
2671 return 0;
2672
2673 ad.type = LSM_AUDIT_DATA_DENTRY;
2674 ad.u.dentry = sb->s_root;
2675 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2676 }
2677
2678 static int selinux_sb_statfs(struct dentry *dentry)
2679 {
2680 const struct cred *cred = current_cred();
2681 struct common_audit_data ad;
2682
2683 ad.type = LSM_AUDIT_DATA_DENTRY;
2684 ad.u.dentry = dentry->d_sb->s_root;
2685 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2686 }
2687
2688 static int selinux_mount(const char *dev_name,
2689 struct path *path,
2690 const char *type,
2691 unsigned long flags,
2692 void *data)
2693 {
2694 const struct cred *cred = current_cred();
2695
2696 if (flags & MS_REMOUNT)
2697 return superblock_has_perm(cred, path->dentry->d_sb,
2698 FILESYSTEM__REMOUNT, NULL);
2699 else
2700 return path_has_perm(cred, path, FILE__MOUNTON);
2701 }
2702
2703 static int selinux_umount(struct vfsmount *mnt, int flags)
2704 {
2705 const struct cred *cred = current_cred();
2706
2707 return superblock_has_perm(cred, mnt->mnt_sb,
2708 FILESYSTEM__UNMOUNT, NULL);
2709 }
2710
2711 /* inode security operations */
2712
2713 static int selinux_inode_alloc_security(struct inode *inode)
2714 {
2715 return inode_alloc_security(inode);
2716 }
2717
2718 static void selinux_inode_free_security(struct inode *inode)
2719 {
2720 inode_free_security(inode);
2721 }
2722
2723 static int selinux_dentry_init_security(struct dentry *dentry, int mode,
2724 struct qstr *name, void **ctx,
2725 u32 *ctxlen)
2726 {
2727 const struct cred *cred = current_cred();
2728 struct task_security_struct *tsec;
2729 struct inode_security_struct *dsec;
2730 struct superblock_security_struct *sbsec;
2731 struct inode *dir = dentry->d_parent->d_inode;
2732 u32 newsid;
2733 int rc;
2734
2735 tsec = cred->security;
2736 dsec = dir->i_security;
2737 sbsec = dir->i_sb->s_security;
2738
2739 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
2740 newsid = tsec->create_sid;
2741 } else {
2742 rc = security_transition_sid(tsec->sid, dsec->sid,
2743 inode_mode_to_security_class(mode),
2744 name,
2745 &newsid);
2746 if (rc) {
2747 printk(KERN_WARNING
2748 "%s: security_transition_sid failed, rc=%d\n",
2749 __func__, -rc);
2750 return rc;
2751 }
2752 }
2753
2754 return security_sid_to_context(newsid, (char **)ctx, ctxlen);
2755 }
2756
2757 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2758 const struct qstr *qstr,
2759 const char **name,
2760 void **value, size_t *len)
2761 {
2762 const struct task_security_struct *tsec = current_security();
2763 struct inode_security_struct *dsec;
2764 struct superblock_security_struct *sbsec;
2765 u32 sid, newsid, clen;
2766 int rc;
2767 char *context;
2768
2769 dsec = dir->i_security;
2770 sbsec = dir->i_sb->s_security;
2771
2772 sid = tsec->sid;
2773 newsid = tsec->create_sid;
2774
2775 if ((sbsec->flags & SE_SBINITIALIZED) &&
2776 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
2777 newsid = sbsec->mntpoint_sid;
2778 else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
2779 rc = security_transition_sid(sid, dsec->sid,
2780 inode_mode_to_security_class(inode->i_mode),
2781 qstr, &newsid);
2782 if (rc) {
2783 printk(KERN_WARNING "%s: "
2784 "security_transition_sid failed, rc=%d (dev=%s "
2785 "ino=%ld)\n",
2786 __func__,
2787 -rc, inode->i_sb->s_id, inode->i_ino);
2788 return rc;
2789 }
2790 }
2791
2792 /* Possibly defer initialization to selinux_complete_init. */
2793 if (sbsec->flags & SE_SBINITIALIZED) {
2794 struct inode_security_struct *isec = inode->i_security;
2795 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2796 isec->sid = newsid;
2797 isec->initialized = 1;
2798 }
2799
2800 if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT))
2801 return -EOPNOTSUPP;
2802
2803 if (name)
2804 *name = XATTR_SELINUX_SUFFIX;
2805
2806 if (value && len) {
2807 rc = security_sid_to_context_force(newsid, &context, &clen);
2808 if (rc)
2809 return rc;
2810 *value = context;
2811 *len = clen;
2812 }
2813
2814 return 0;
2815 }
2816
2817 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
2818 {
2819 return may_create(dir, dentry, SECCLASS_FILE);
2820 }
2821
2822 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2823 {
2824 return may_link(dir, old_dentry, MAY_LINK);
2825 }
2826
2827 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2828 {
2829 return may_link(dir, dentry, MAY_UNLINK);
2830 }
2831
2832 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2833 {
2834 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2835 }
2836
2837 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
2838 {
2839 return may_create(dir, dentry, SECCLASS_DIR);
2840 }
2841
2842 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2843 {
2844 return may_link(dir, dentry, MAY_RMDIR);
2845 }
2846
2847 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
2848 {
2849 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2850 }
2851
2852 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2853 struct inode *new_inode, struct dentry *new_dentry)
2854 {
2855 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2856 }
2857
2858 static int selinux_inode_readlink(struct dentry *dentry)
2859 {
2860 const struct cred *cred = current_cred();
2861
2862 return dentry_has_perm(cred, dentry, FILE__READ);
2863 }
2864
2865 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2866 {
2867 const struct cred *cred = current_cred();
2868
2869 return dentry_has_perm(cred, dentry, FILE__READ);
2870 }
2871
2872 static noinline int audit_inode_permission(struct inode *inode,
2873 u32 perms, u32 audited, u32 denied,
2874 int result,
2875 unsigned flags)
2876 {
2877 struct common_audit_data ad;
2878 struct inode_security_struct *isec = inode->i_security;
2879 int rc;
2880
2881 ad.type = LSM_AUDIT_DATA_INODE;
2882 ad.u.inode = inode;
2883
2884 rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
2885 audited, denied, result, &ad, flags);
2886 if (rc)
2887 return rc;
2888 return 0;
2889 }
2890
2891 static int selinux_inode_permission(struct inode *inode, int mask)
2892 {
2893 const struct cred *cred = current_cred();
2894 u32 perms;
2895 bool from_access;
2896 unsigned flags = mask & MAY_NOT_BLOCK;
2897 struct inode_security_struct *isec;
2898 u32 sid;
2899 struct av_decision avd;
2900 int rc, rc2;
2901 u32 audited, denied;
2902
2903 from_access = mask & MAY_ACCESS;
2904 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
2905
2906 /* No permission to check. Existence test. */
2907 if (!mask)
2908 return 0;
2909
2910 validate_creds(cred);
2911
2912 if (unlikely(IS_PRIVATE(inode)))
2913 return 0;
2914
2915 perms = file_mask_to_av(inode->i_mode, mask);
2916
2917 sid = cred_sid(cred);
2918 isec = inode->i_security;
2919
2920 rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);
2921 audited = avc_audit_required(perms, &avd, rc,
2922 from_access ? FILE__AUDIT_ACCESS : 0,
2923 &denied);
2924 if (likely(!audited))
2925 return rc;
2926
2927 rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags);
2928 if (rc2)
2929 return rc2;
2930 return rc;
2931 }
2932
2933 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2934 {
2935 const struct cred *cred = current_cred();
2936 unsigned int ia_valid = iattr->ia_valid;
2937 __u32 av = FILE__WRITE;
2938
2939 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2940 if (ia_valid & ATTR_FORCE) {
2941 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2942 ATTR_FORCE);
2943 if (!ia_valid)
2944 return 0;
2945 }
2946
2947 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2948 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2949 return dentry_has_perm(cred, dentry, FILE__SETATTR);
2950
2951 if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE))
2952 av |= FILE__OPEN;
2953
2954 return dentry_has_perm(cred, dentry, av);
2955 }
2956
2957 static int selinux_inode_getattr(const struct path *path)
2958 {
2959 return path_has_perm(current_cred(), path, FILE__GETATTR);
2960 }
2961
2962 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2963 {
2964 const struct cred *cred = current_cred();
2965
2966 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2967 sizeof XATTR_SECURITY_PREFIX - 1)) {
2968 if (!strcmp(name, XATTR_NAME_CAPS)) {
2969 if (!capable(CAP_SETFCAP))
2970 return -EPERM;
2971 } else if (!capable(CAP_SYS_ADMIN)) {
2972 /* A different attribute in the security namespace.
2973 Restrict to administrator. */
2974 return -EPERM;
2975 }
2976 }
2977
2978 /* Not an attribute we recognize, so just check the
2979 ordinary setattr permission. */
2980 return dentry_has_perm(cred, dentry, FILE__SETATTR);
2981 }
2982
2983 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2984 const void *value, size_t size, int flags)
2985 {
2986 struct inode *inode = dentry->d_inode;
2987 struct inode_security_struct *isec = inode->i_security;
2988 struct superblock_security_struct *sbsec;
2989 struct common_audit_data ad;
2990 u32 newsid, sid = current_sid();
2991 int rc = 0;
2992
2993 if (strcmp(name, XATTR_NAME_SELINUX))
2994 return selinux_inode_setotherxattr(dentry, name);
2995
2996 sbsec = inode->i_sb->s_security;
2997 if (!(sbsec->flags & SBLABEL_MNT))
2998 return -EOPNOTSUPP;
2999
3000 if (!inode_owner_or_capable(inode))
3001 return -EPERM;
3002
3003 ad.type = LSM_AUDIT_DATA_DENTRY;
3004 ad.u.dentry = dentry;
3005
3006 rc = avc_has_perm(sid, isec->sid, isec->sclass,
3007 FILE__RELABELFROM, &ad);
3008 if (rc)
3009 return rc;
3010
3011 rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
3012 if (rc == -EINVAL) {
3013 if (!capable(CAP_MAC_ADMIN)) {
3014 struct audit_buffer *ab;
3015 size_t audit_size;
3016 const char *str;
3017
3018 /* We strip a nul only if it is at the end, otherwise the
3019 * context contains a nul and we should audit that */
3020 if (value) {
3021 str = value;
3022 if (str[size - 1] == '\0')
3023 audit_size = size - 1;
3024 else
3025 audit_size = size;
3026 } else {
3027 str = "";
3028 audit_size = 0;
3029 }
3030 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
3031 audit_log_format(ab, "op=setxattr invalid_context=");
3032 audit_log_n_untrustedstring(ab, value, audit_size);
3033 audit_log_end(ab);
3034
3035 return rc;
3036 }
3037 rc = security_context_to_sid_force(value, size, &newsid);
3038 }
3039 if (rc)
3040 return rc;
3041
3042 rc = avc_has_perm(sid, newsid, isec->sclass,
3043 FILE__RELABELTO, &ad);
3044 if (rc)
3045 return rc;
3046
3047 rc = security_validate_transition(isec->sid, newsid, sid,
3048 isec->sclass);
3049 if (rc)
3050 return rc;
3051
3052 return avc_has_perm(newsid,
3053 sbsec->sid,
3054 SECCLASS_FILESYSTEM,
3055 FILESYSTEM__ASSOCIATE,
3056 &ad);
3057 }
3058
3059 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3060 const void *value, size_t size,
3061 int flags)
3062 {
3063 struct inode *inode = dentry->d_inode;
3064 struct inode_security_struct *isec = inode->i_security;
3065 u32 newsid;
3066 int rc;
3067
3068 if (strcmp(name, XATTR_NAME_SELINUX)) {
3069 /* Not an attribute we recognize, so nothing to do. */
3070 return;
3071 }
3072
3073 rc = security_context_to_sid_force(value, size, &newsid);
3074 if (rc) {
3075 printk(KERN_ERR "SELinux: unable to map context to SID"
3076 "for (%s, %lu), rc=%d\n",
3077 inode->i_sb->s_id, inode->i_ino, -rc);
3078 return;
3079 }
3080
3081 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3082 isec->sid = newsid;
3083 isec->initialized = 1;
3084
3085 return;
3086 }
3087
3088 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
3089 {
3090 const struct cred *cred = current_cred();
3091
3092 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3093 }
3094
3095 static int selinux_inode_listxattr(struct dentry *dentry)
3096 {
3097 const struct cred *cred = current_cred();
3098
3099 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3100 }
3101
3102 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
3103 {
3104 if (strcmp(name, XATTR_NAME_SELINUX))
3105 return selinux_inode_setotherxattr(dentry, name);
3106
3107 /* No one is allowed to remove a SELinux security label.
3108 You can change the label, but all data must be labeled. */
3109 return -EACCES;
3110 }
3111
3112 /*
3113 * Copy the inode security context value to the user.
3114 *
3115 * Permission check is handled by selinux_inode_getxattr hook.
3116 */
3117 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
3118 {
3119 u32 size;
3120 int error;
3121 char *context = NULL;
3122 struct inode_security_struct *isec = inode->i_security;
3123
3124 if (strcmp(name, XATTR_SELINUX_SUFFIX))
3125 return -EOPNOTSUPP;
3126
3127 /*
3128 * If the caller has CAP_MAC_ADMIN, then get the raw context
3129 * value even if it is not defined by current policy; otherwise,
3130 * use the in-core value under current policy.
3131 * Use the non-auditing forms of the permission checks since
3132 * getxattr may be called by unprivileged processes commonly
3133 * and lack of permission just means that we fall back to the
3134 * in-core context value, not a denial.
3135 */
3136 error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
3137 SECURITY_CAP_NOAUDIT);
3138 if (!error)
3139 error = security_sid_to_context_force(isec->sid, &context,
3140 &size);
3141 else
3142 error = security_sid_to_context(isec->sid, &context, &size);
3143 if (error)
3144 return error;
3145 error = size;
3146 if (alloc) {
3147 *buffer = context;
3148 goto out_nofree;
3149 }
3150 kfree(context);
3151 out_nofree:
3152 return error;
3153 }
3154
3155 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3156 const void *value, size_t size, int flags)
3157 {
3158 struct inode_security_struct *isec = inode->i_security;
3159 u32 newsid;
3160 int rc;
3161
3162 if (strcmp(name, XATTR_SELINUX_SUFFIX))
3163 return -EOPNOTSUPP;
3164
3165 if (!value || !size)
3166 return -EACCES;
3167
3168 rc = security_context_to_sid((void *)value, size, &newsid, GFP_KERNEL);
3169 if (rc)
3170 return rc;
3171
3172 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3173 isec->sid = newsid;
3174 isec->initialized = 1;
3175 return 0;
3176 }
3177
3178 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
3179 {
3180 const int len = sizeof(XATTR_NAME_SELINUX);
3181 if (buffer && len <= buffer_size)
3182 memcpy(buffer, XATTR_NAME_SELINUX, len);
3183 return len;
3184 }
3185
3186 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
3187 {
3188 struct inode_security_struct *isec = inode->i_security;
3189 *secid = isec->sid;
3190 }
3191
3192 /* file security operations */
3193
3194 static int selinux_revalidate_file_permission(struct file *file, int mask)
3195 {
3196 const struct cred *cred = current_cred();
3197 struct inode *inode = file_inode(file);
3198
3199 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
3200 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
3201 mask |= MAY_APPEND;
3202
3203 return file_has_perm(cred, file,
3204 file_mask_to_av(inode->i_mode, mask));
3205 }
3206
3207 static int selinux_file_permission(struct file *file, int mask)
3208 {
3209 struct inode *inode = file_inode(file);
3210 struct file_security_struct *fsec = file->f_security;
3211 struct inode_security_struct *isec = inode->i_security;
3212 u32 sid = current_sid();
3213
3214 if (!mask)
3215 /* No permission to check. Existence test. */
3216 return 0;
3217
3218 if (sid == fsec->sid && fsec->isid == isec->sid &&
3219 fsec->pseqno == avc_policy_seqno())
3220 /* No change since file_open check. */
3221 return 0;
3222
3223 return selinux_revalidate_file_permission(file, mask);
3224 }
3225
3226 static int selinux_file_alloc_security(struct file *file)
3227 {
3228 return file_alloc_security(file);
3229 }
3230
3231 static void selinux_file_free_security(struct file *file)
3232 {
3233 file_free_security(file);
3234 }
3235
3236 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3237 unsigned long arg)
3238 {
3239 const struct cred *cred = current_cred();
3240 int error = 0;
3241
3242 switch (cmd) {
3243 case FIONREAD:
3244 /* fall through */
3245 case FIBMAP:
3246 /* fall through */
3247 case FIGETBSZ:
3248 /* fall through */
3249 case FS_IOC_GETFLAGS:
3250 /* fall through */
3251 case FS_IOC_GETVERSION:
3252 error = file_has_perm(cred, file, FILE__GETATTR);
3253 break;
3254
3255 case FS_IOC_SETFLAGS:
3256 /* fall through */
3257 case FS_IOC_SETVERSION:
3258 error = file_has_perm(cred, file, FILE__SETATTR);
3259 break;
3260
3261 /* sys_ioctl() checks */
3262 case FIONBIO:
3263 /* fall through */
3264 case FIOASYNC:
3265 error = file_has_perm(cred, file, 0);
3266 break;
3267
3268 case KDSKBENT:
3269 case KDSKBSENT:
3270 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3271 SECURITY_CAP_AUDIT);
3272 break;
3273
3274 /* default case assumes that the command will go
3275 * to the file's ioctl() function.
3276 */
3277 default:
3278 error = file_has_perm(cred, file, FILE__IOCTL);
3279 }
3280 return error;
3281 }
3282
3283 static int default_noexec;
3284
3285 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3286 {
3287 const struct cred *cred = current_cred();
3288 int rc = 0;
3289
3290 if (default_noexec &&
3291 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
3292 /*
3293 * We are making executable an anonymous mapping or a
3294 * private file mapping that will also be writable.
3295 * This has an additional check.
3296 */
3297 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
3298 if (rc)
3299 goto error;
3300 }
3301
3302 if (file) {
3303 /* read access is always possible with a mapping */
3304 u32 av = FILE__READ;
3305
3306 /* write access only matters if the mapping is shared */
3307 if (shared && (prot & PROT_WRITE))
3308 av |= FILE__WRITE;
3309
3310 if (prot & PROT_EXEC)
3311 av |= FILE__EXECUTE;
3312
3313 return file_has_perm(cred, file, av);
3314 }
3315
3316 error:
3317 return rc;
3318 }
3319
3320 static int selinux_mmap_addr(unsigned long addr)
3321 {
3322 int rc;
3323
3324 /* do DAC check on address space usage */
3325 rc = cap_mmap_addr(addr);
3326 if (rc)
3327 return rc;
3328
3329 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3330 u32 sid = current_sid();
3331 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3332 MEMPROTECT__MMAP_ZERO, NULL);
3333 }
3334
3335 return rc;
3336 }
3337
3338 static int selinux_mmap_file(struct file *file, unsigned long reqprot,
3339 unsigned long prot, unsigned long flags)
3340 {
3341 if (selinux_checkreqprot)
3342 prot = reqprot;
3343
3344 return file_map_prot_check(file, prot,
3345 (flags & MAP_TYPE) == MAP_SHARED);
3346 }
3347
3348 static int selinux_file_mprotect(struct vm_area_struct *vma,
3349 unsigned long reqprot,
3350 unsigned long prot)
3351 {
3352 const struct cred *cred = current_cred();
3353
3354 if (selinux_checkreqprot)
3355 prot = reqprot;
3356
3357 if (default_noexec &&
3358 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3359 int rc = 0;
3360 if (vma->vm_start >= vma->vm_mm->start_brk &&
3361 vma->vm_end <= vma->vm_mm->brk) {
3362 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3363 } else if (!vma->vm_file &&
3364 vma->vm_start <= vma->vm_mm->start_stack &&
3365 vma->vm_end >= vma->vm_mm->start_stack) {
3366 rc = current_has_perm(current, PROCESS__EXECSTACK);
3367 } else if (vma->vm_file && vma->anon_vma) {
3368 /*
3369 * We are making executable a file mapping that has
3370 * had some COW done. Since pages might have been
3371 * written, check ability to execute the possibly
3372 * modified content. This typically should only
3373 * occur for text relocations.
3374 */
3375 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3376 }
3377 if (rc)
3378 return rc;
3379 }
3380
3381 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3382 }
3383
3384 static int selinux_file_lock(struct file *file, unsigned int cmd)
3385 {
3386 const struct cred *cred = current_cred();
3387
3388 return file_has_perm(cred, file, FILE__LOCK);
3389 }
3390
3391 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3392 unsigned long arg)
3393 {
3394 const struct cred *cred = current_cred();
3395 int err = 0;
3396
3397 switch (cmd) {
3398 case F_SETFL:
3399 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3400 err = file_has_perm(cred, file, FILE__WRITE);
3401 break;
3402 }
3403 /* fall through */
3404 case F_SETOWN:
3405 case F_SETSIG:
3406 case F_GETFL:
3407 case F_GETOWN:
3408 case F_GETSIG:
3409 case F_GETOWNER_UIDS:
3410 /* Just check FD__USE permission */
3411 err = file_has_perm(cred, file, 0);
3412 break;
3413 case F_GETLK:
3414 case F_SETLK:
3415 case F_SETLKW:
3416 case F_OFD_GETLK:
3417 case F_OFD_SETLK:
3418 case F_OFD_SETLKW:
3419 #if BITS_PER_LONG == 32
3420 case F_GETLK64:
3421 case F_SETLK64:
3422 case F_SETLKW64:
3423 #endif
3424 err = file_has_perm(cred, file, FILE__LOCK);
3425 break;
3426 }
3427
3428 return err;
3429 }
3430
3431 static void selinux_file_set_fowner(struct file *file)
3432 {
3433 struct file_security_struct *fsec;
3434
3435 fsec = file->f_security;
3436 fsec->fown_sid = current_sid();
3437 }
3438
3439 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3440 struct fown_struct *fown, int signum)
3441 {
3442 struct file *file;
3443 u32 sid = task_sid(tsk);
3444 u32 perm;
3445 struct file_security_struct *fsec;
3446
3447 /* struct fown_struct is never outside the context of a struct file */
3448 file = container_of(fown, struct file, f_owner);
3449
3450 fsec = file->f_security;
3451
3452 if (!signum)
3453 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3454 else
3455 perm = signal_to_av(signum);
3456
3457 return avc_has_perm(fsec->fown_sid, sid,
3458 SECCLASS_PROCESS, perm, NULL);
3459 }
3460
3461 static int selinux_file_receive(struct file *file)
3462 {
3463 const struct cred *cred = current_cred();
3464
3465 return file_has_perm(cred, file, file_to_av(file));
3466 }
3467
3468 static int selinux_file_open(struct file *file, const struct cred *cred)
3469 {
3470 struct file_security_struct *fsec;
3471 struct inode_security_struct *isec;
3472
3473 fsec = file->f_security;
3474 isec = file_inode(file)->i_security;
3475 /*
3476 * Save inode label and policy sequence number
3477 * at open-time so that selinux_file_permission
3478 * can determine whether revalidation is necessary.
3479 * Task label is already saved in the file security
3480 * struct as its SID.
3481 */
3482 fsec->isid = isec->sid;
3483 fsec->pseqno = avc_policy_seqno();
3484 /*
3485 * Since the inode label or policy seqno may have changed
3486 * between the selinux_inode_permission check and the saving
3487 * of state above, recheck that access is still permitted.
3488 * Otherwise, access might never be revalidated against the
3489 * new inode label or new policy.
3490 * This check is not redundant - do not remove.
3491 */
3492 return file_path_has_perm(cred, file, open_file_to_av(file));
3493 }
3494
3495 /* task security operations */
3496
3497 static int selinux_task_create(unsigned long clone_flags)
3498 {
3499 return current_has_perm(current, PROCESS__FORK);
3500 }
3501
3502 /*
3503 * allocate the SELinux part of blank credentials
3504 */
3505 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3506 {
3507 struct task_security_struct *tsec;
3508
3509 tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3510 if (!tsec)
3511 return -ENOMEM;
3512
3513 cred->security = tsec;
3514 return 0;
3515 }
3516
3517 /*
3518 * detach and free the LSM part of a set of credentials
3519 */
3520 static void selinux_cred_free(struct cred *cred)
3521 {
3522 struct task_security_struct *tsec = cred->security;
3523
3524 /*
3525 * cred->security == NULL if security_cred_alloc_blank() or
3526 * security_prepare_creds() returned an error.
3527 */
3528 BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE);
3529 cred->security = (void *) 0x7UL;
3530 kfree(tsec);
3531 }
3532
3533 /*
3534 * prepare a new set of credentials for modification
3535 */
3536 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3537 gfp_t gfp)
3538 {
3539 const struct task_security_struct *old_tsec;
3540 struct task_security_struct *tsec;
3541
3542 old_tsec = old->security;
3543
3544 tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3545 if (!tsec)
3546 return -ENOMEM;
3547
3548 new->security = tsec;
3549 return 0;
3550 }
3551
3552 /*
3553 * transfer the SELinux data to a blank set of creds
3554 */
3555 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3556 {
3557 const struct task_security_struct *old_tsec = old->security;
3558 struct task_security_struct *tsec = new->security;
3559
3560 *tsec = *old_tsec;
3561 }
3562
3563 /*
3564 * set the security data for a kernel service
3565 * - all the creation contexts are set to unlabelled
3566 */
3567 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3568 {
3569 struct task_security_struct *tsec = new->security;
3570 u32 sid = current_sid();
3571 int ret;
3572
3573 ret = avc_has_perm(sid, secid,
3574 SECCLASS_KERNEL_SERVICE,
3575 KERNEL_SERVICE__USE_AS_OVERRIDE,
3576 NULL);
3577 if (ret == 0) {
3578 tsec->sid = secid;
3579 tsec->create_sid = 0;
3580 tsec->keycreate_sid = 0;
3581 tsec->sockcreate_sid = 0;
3582 }
3583 return ret;
3584 }
3585
3586 /*
3587 * set the file creation context in a security record to the same as the
3588 * objective context of the specified inode
3589 */
3590 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3591 {
3592 struct inode_security_struct *isec = inode->i_security;
3593 struct task_security_struct *tsec = new->security;
3594 u32 sid = current_sid();
3595 int ret;
3596
3597 ret = avc_has_perm(sid, isec->sid,
3598 SECCLASS_KERNEL_SERVICE,
3599 KERNEL_SERVICE__CREATE_FILES_AS,
3600 NULL);
3601
3602 if (ret == 0)
3603 tsec->create_sid = isec->sid;
3604 return ret;
3605 }
3606
3607 static int selinux_kernel_module_request(char *kmod_name)
3608 {
3609 u32 sid;
3610 struct common_audit_data ad;
3611
3612 sid = task_sid(current);
3613
3614 ad.type = LSM_AUDIT_DATA_KMOD;
3615 ad.u.kmod_name = kmod_name;
3616
3617 return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
3618 SYSTEM__MODULE_REQUEST, &ad);
3619 }
3620
3621 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3622 {
3623 return current_has_perm(p, PROCESS__SETPGID);
3624 }
3625
3626 static int selinux_task_getpgid(struct task_struct *p)
3627 {
3628 return current_has_perm(p, PROCESS__GETPGID);
3629 }
3630
3631 static int selinux_task_getsid(struct task_struct *p)
3632 {
3633 return current_has_perm(p, PROCESS__GETSESSION);
3634 }
3635
3636 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3637 {
3638 *secid = task_sid(p);
3639 }
3640
3641 static int selinux_task_setnice(struct task_struct *p, int nice)
3642 {
3643 int rc;
3644
3645 rc = cap_task_setnice(p, nice);
3646 if (rc)
3647 return rc;
3648
3649 return current_has_perm(p, PROCESS__SETSCHED);
3650 }
3651
3652 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3653 {
3654 int rc;
3655
3656 rc = cap_task_setioprio(p, ioprio);
3657 if (rc)
3658 return rc;
3659
3660 return current_has_perm(p, PROCESS__SETSCHED);
3661 }
3662
3663 static int selinux_task_getioprio(struct task_struct *p)
3664 {
3665 return current_has_perm(p, PROCESS__GETSCHED);
3666 }
3667
3668 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
3669 struct rlimit *new_rlim)
3670 {
3671 struct rlimit *old_rlim = p->signal->rlim + resource;
3672
3673 /* Control the ability to change the hard limit (whether
3674 lowering or raising it), so that the hard limit can
3675 later be used as a safe reset point for the soft limit
3676 upon context transitions. See selinux_bprm_committing_creds. */
3677 if (old_rlim->rlim_max != new_rlim->rlim_max)
3678 return current_has_perm(p, PROCESS__SETRLIMIT);
3679
3680 return 0;
3681 }
3682
3683 static int selinux_task_setscheduler(struct task_struct *p)
3684 {
3685 int rc;
3686
3687 rc = cap_task_setscheduler(p);
3688 if (rc)
3689 return rc;
3690
3691 return current_has_perm(p, PROCESS__SETSCHED);
3692 }
3693
3694 static int selinux_task_getscheduler(struct task_struct *p)
3695 {
3696 return current_has_perm(p, PROCESS__GETSCHED);
3697 }
3698
3699 static int selinux_task_movememory(struct task_struct *p)
3700 {
3701 return current_has_perm(p, PROCESS__SETSCHED);
3702 }
3703
3704 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3705 int sig, u32 secid)
3706 {
3707 u32 perm;
3708 int rc;
3709
3710 if (!sig)
3711 perm = PROCESS__SIGNULL; /* null signal; existence test */
3712 else
3713 perm = signal_to_av(sig);
3714 if (secid)
3715 rc = avc_has_perm(secid, task_sid(p),
3716 SECCLASS_PROCESS, perm, NULL);
3717 else
3718 rc = current_has_perm(p, perm);
3719 return rc;
3720 }
3721
3722 static int selinux_task_wait(struct task_struct *p)
3723 {
3724 return task_has_perm(p, current, PROCESS__SIGCHLD);
3725 }
3726
3727 static void selinux_task_to_inode(struct task_struct *p,
3728 struct inode *inode)
3729 {
3730 struct inode_security_struct *isec = inode->i_security;
3731 u32 sid = task_sid(p);
3732
3733 isec->sid = sid;
3734 isec->initialized = 1;
3735 }
3736
3737 /* Returns error only if unable to parse addresses */
3738 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3739 struct common_audit_data *ad, u8 *proto)
3740 {
3741 int offset, ihlen, ret = -EINVAL;
3742 struct iphdr _iph, *ih;
3743
3744 offset = skb_network_offset(skb);
3745 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3746 if (ih == NULL)
3747 goto out;
3748
3749 ihlen = ih->ihl * 4;
3750 if (ihlen < sizeof(_iph))
3751 goto out;
3752
3753 ad->u.net->v4info.saddr = ih->saddr;
3754 ad->u.net->v4info.daddr = ih->daddr;
3755 ret = 0;
3756
3757 if (proto)
3758 *proto = ih->protocol;
3759
3760 switch (ih->protocol) {
3761 case IPPROTO_TCP: {
3762 struct tcphdr _tcph, *th;
3763
3764 if (ntohs(ih->frag_off) & IP_OFFSET)
3765 break;
3766
3767 offset += ihlen;
3768 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3769 if (th == NULL)
3770 break;
3771
3772 ad->u.net->sport = th->source;
3773 ad->u.net->dport = th->dest;
3774 break;
3775 }
3776
3777 case IPPROTO_UDP: {
3778 struct udphdr _udph, *uh;
3779
3780 if (ntohs(ih->frag_off) & IP_OFFSET)
3781 break;
3782
3783 offset += ihlen;
3784 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3785 if (uh == NULL)
3786 break;
3787
3788 ad->u.net->sport = uh->source;
3789 ad->u.net->dport = uh->dest;
3790 break;
3791 }
3792
3793 case IPPROTO_DCCP: {
3794 struct dccp_hdr _dccph, *dh;
3795
3796 if (ntohs(ih->frag_off) & IP_OFFSET)
3797 break;
3798
3799 offset += ihlen;
3800 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3801 if (dh == NULL)
3802 break;
3803
3804 ad->u.net->sport = dh->dccph_sport;
3805 ad->u.net->dport = dh->dccph_dport;
3806 break;
3807 }
3808
3809 default:
3810 break;
3811 }
3812 out:
3813 return ret;
3814 }
3815
3816 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3817
3818 /* Returns error only if unable to parse addresses */
3819 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3820 struct common_audit_data *ad, u8 *proto)
3821 {
3822 u8 nexthdr;
3823 int ret = -EINVAL, offset;
3824 struct ipv6hdr _ipv6h, *ip6;
3825 __be16 frag_off;
3826
3827 offset = skb_network_offset(skb);
3828 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3829 if (ip6 == NULL)
3830 goto out;
3831
3832 ad->u.net->v6info.saddr = ip6->saddr;
3833 ad->u.net->v6info.daddr = ip6->daddr;
3834 ret = 0;
3835
3836 nexthdr = ip6->nexthdr;
3837 offset += sizeof(_ipv6h);
3838 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
3839 if (offset < 0)
3840 goto out;
3841
3842 if (proto)
3843 *proto = nexthdr;
3844
3845 switch (nexthdr) {
3846 case IPPROTO_TCP: {
3847 struct tcphdr _tcph, *th;
3848
3849 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3850 if (th == NULL)
3851 break;
3852
3853 ad->u.net->sport = th->source;
3854 ad->u.net->dport = th->dest;
3855 break;
3856 }
3857
3858 case IPPROTO_UDP: {
3859 struct udphdr _udph, *uh;
3860
3861 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3862 if (uh == NULL)
3863 break;
3864
3865 ad->u.net->sport = uh->source;
3866 ad->u.net->dport = uh->dest;
3867 break;
3868 }
3869
3870 case IPPROTO_DCCP: {
3871 struct dccp_hdr _dccph, *dh;
3872
3873 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3874 if (dh == NULL)
3875 break;
3876
3877 ad->u.net->sport = dh->dccph_sport;
3878 ad->u.net->dport = dh->dccph_dport;
3879 break;
3880 }
3881
3882 /* includes fragments */
3883 default:
3884 break;
3885 }
3886 out:
3887 return ret;
3888 }
3889
3890 #endif /* IPV6 */
3891
3892 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3893 char **_addrp, int src, u8 *proto)
3894 {
3895 char *addrp;
3896 int ret;
3897
3898 switch (ad->u.net->family) {
3899 case PF_INET:
3900 ret = selinux_parse_skb_ipv4(skb, ad, proto);
3901 if (ret)
3902 goto parse_error;
3903 addrp = (char *)(src ? &ad->u.net->v4info.saddr :
3904 &ad->u.net->v4info.daddr);
3905 goto okay;
3906
3907 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3908 case PF_INET6:
3909 ret = selinux_parse_skb_ipv6(skb, ad, proto);
3910 if (ret)
3911 goto parse_error;
3912 addrp = (char *)(src ? &ad->u.net->v6info.saddr :
3913 &ad->u.net->v6info.daddr);
3914 goto okay;
3915 #endif /* IPV6 */
3916 default:
3917 addrp = NULL;
3918 goto okay;
3919 }
3920
3921 parse_error:
3922 printk(KERN_WARNING
3923 "SELinux: failure in selinux_parse_skb(),"
3924 " unable to parse packet\n");
3925 return ret;
3926
3927 okay:
3928 if (_addrp)
3929 *_addrp = addrp;
3930 return 0;
3931 }
3932
3933 /**
3934 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3935 * @skb: the packet
3936 * @family: protocol family
3937 * @sid: the packet's peer label SID
3938 *
3939 * Description:
3940 * Check the various different forms of network peer labeling and determine
3941 * the peer label/SID for the packet; most of the magic actually occurs in
3942 * the security server function security_net_peersid_cmp(). The function
3943 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
3944 * or -EACCES if @sid is invalid due to inconsistencies with the different
3945 * peer labels.
3946 *
3947 */
3948 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3949 {
3950 int err;
3951 u32 xfrm_sid;
3952 u32 nlbl_sid;
3953 u32 nlbl_type;
3954
3955 err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
3956 if (unlikely(err))
3957 return -EACCES;
3958 err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3959 if (unlikely(err))
3960 return -EACCES;
3961
3962 err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
3963 if (unlikely(err)) {
3964 printk(KERN_WARNING
3965 "SELinux: failure in selinux_skb_peerlbl_sid(),"
3966 " unable to determine packet's peer label\n");
3967 return -EACCES;
3968 }
3969
3970 return 0;
3971 }
3972
3973 /**
3974 * selinux_conn_sid - Determine the child socket label for a connection
3975 * @sk_sid: the parent socket's SID
3976 * @skb_sid: the packet's SID
3977 * @conn_sid: the resulting connection SID
3978 *
3979 * If @skb_sid is valid then the user:role:type information from @sk_sid is
3980 * combined with the MLS information from @skb_sid in order to create
3981 * @conn_sid. If @skb_sid is not valid then then @conn_sid is simply a copy
3982 * of @sk_sid. Returns zero on success, negative values on failure.
3983 *
3984 */
3985 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
3986 {
3987 int err = 0;
3988
3989 if (skb_sid != SECSID_NULL)
3990 err = security_sid_mls_copy(sk_sid, skb_sid, conn_sid);
3991 else
3992 *conn_sid = sk_sid;
3993
3994 return err;
3995 }
3996
3997 /* socket security operations */
3998
3999 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
4000 u16 secclass, u32 *socksid)
4001 {
4002 if (tsec->sockcreate_sid > SECSID_NULL) {
4003 *socksid = tsec->sockcreate_sid;
4004 return 0;
4005 }
4006
4007 return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
4008 socksid);
4009 }
4010
4011 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
4012 {
4013 struct sk_security_struct *sksec = sk->sk_security;
4014 struct common_audit_data ad;
4015 struct lsm_network_audit net = {0,};
4016 u32 tsid = task_sid(task);
4017
4018 if (sksec->sid == SECINITSID_KERNEL)
4019 return 0;
4020
4021 ad.type = LSM_AUDIT_DATA_NET;
4022 ad.u.net = &net;
4023 ad.u.net->sk = sk;
4024
4025 return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
4026 }
4027
4028 static int selinux_socket_create(int family, int type,
4029 int protocol, int kern)
4030 {
4031 const struct task_security_struct *tsec = current_security();
4032 u32 newsid;
4033 u16 secclass;
4034 int rc;
4035
4036 if (kern)
4037 return 0;
4038
4039 secclass = socket_type_to_security_class(family, type, protocol);
4040 rc = socket_sockcreate_sid(tsec, secclass, &newsid);
4041 if (rc)
4042 return rc;
4043
4044 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
4045 }
4046
4047 static int selinux_socket_post_create(struct socket *sock, int family,
4048 int type, int protocol, int kern)
4049 {
4050 const struct task_security_struct *tsec = current_security();
4051 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
4052 struct sk_security_struct *sksec;
4053 int err = 0;
4054
4055 isec->sclass = socket_type_to_security_class(family, type, protocol);
4056
4057 if (kern)
4058 isec->sid = SECINITSID_KERNEL;
4059 else {
4060 err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
4061 if (err)
4062 return err;
4063 }
4064
4065 isec->initialized = 1;
4066
4067 if (sock->sk) {
4068 sksec = sock->sk->sk_security;
4069 sksec->sid = isec->sid;
4070 sksec->sclass = isec->sclass;
4071 err = selinux_netlbl_socket_post_create(sock->sk, family);
4072 }
4073
4074 return err;
4075 }
4076
4077 /* Range of port numbers used to automatically bind.
4078 Need to determine whether we should perform a name_bind
4079 permission check between the socket and the port number. */
4080
4081 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
4082 {
4083 struct sock *sk = sock->sk;
4084 u16 family;
4085 int err;
4086
4087 err = sock_has_perm(current, sk, SOCKET__BIND);
4088 if (err)
4089 goto out;
4090
4091 /*
4092 * If PF_INET or PF_INET6, check name_bind permission for the port.
4093 * Multiple address binding for SCTP is not supported yet: we just
4094 * check the first address now.
4095 */
4096 family = sk->sk_family;
4097 if (family == PF_INET || family == PF_INET6) {
4098 char *addrp;
4099 struct sk_security_struct *sksec = sk->sk_security;
4100 struct common_audit_data ad;
4101 struct lsm_network_audit net = {0,};
4102 struct sockaddr_in *addr4 = NULL;
4103 struct sockaddr_in6 *addr6 = NULL;
4104 unsigned short snum;
4105 u32 sid, node_perm;
4106
4107 if (family == PF_INET) {
4108 addr4 = (struct sockaddr_in *)address;
4109 snum = ntohs(addr4->sin_port);
4110 addrp = (char *)&addr4->sin_addr.s_addr;
4111 } else {
4112 addr6 = (struct sockaddr_in6 *)address;
4113 snum = ntohs(addr6->sin6_port);
4114 addrp = (char *)&addr6->sin6_addr.s6_addr;
4115 }
4116
4117 if (snum) {
4118 int low, high;
4119
4120 inet_get_local_port_range(sock_net(sk), &low, &high);
4121
4122 if (snum < max(PROT_SOCK, low) || snum > high) {
4123 err = sel_netport_sid(sk->sk_protocol,
4124 snum, &sid);
4125 if (err)
4126 goto out;
4127 ad.type = LSM_AUDIT_DATA_NET;
4128 ad.u.net = &net;
4129 ad.u.net->sport = htons(snum);
4130 ad.u.net->family = family;
4131 err = avc_has_perm(sksec->sid, sid,
4132 sksec->sclass,
4133 SOCKET__NAME_BIND, &ad);
4134 if (err)
4135 goto out;
4136 }
4137 }
4138
4139 switch (sksec->sclass) {
4140 case SECCLASS_TCP_SOCKET:
4141 node_perm = TCP_SOCKET__NODE_BIND;
4142 break;
4143
4144 case SECCLASS_UDP_SOCKET:
4145 node_perm = UDP_SOCKET__NODE_BIND;
4146 break;
4147
4148 case SECCLASS_DCCP_SOCKET:
4149 node_perm = DCCP_SOCKET__NODE_BIND;
4150 break;
4151
4152 default:
4153 node_perm = RAWIP_SOCKET__NODE_BIND;
4154 break;
4155 }
4156
4157 err = sel_netnode_sid(addrp, family, &sid);
4158 if (err)
4159 goto out;
4160
4161 ad.type = LSM_AUDIT_DATA_NET;
4162 ad.u.net = &net;
4163 ad.u.net->sport = htons(snum);
4164 ad.u.net->family = family;
4165
4166 if (family == PF_INET)
4167 ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
4168 else
4169 ad.u.net->v6info.saddr = addr6->sin6_addr;
4170
4171 err = avc_has_perm(sksec->sid, sid,
4172 sksec->sclass, node_perm, &ad);
4173 if (err)
4174 goto out;
4175 }
4176 out:
4177 return err;
4178 }
4179
4180 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
4181 {
4182 struct sock *sk = sock->sk;
4183 struct sk_security_struct *sksec = sk->sk_security;
4184 int err;
4185
4186 err = sock_has_perm(current, sk, SOCKET__CONNECT);
4187 if (err)
4188 return err;
4189
4190 /*
4191 * If a TCP or DCCP socket, check name_connect permission for the port.
4192 */
4193 if (sksec->sclass == SECCLASS_TCP_SOCKET ||
4194 sksec->sclass == SECCLASS_DCCP_SOCKET) {
4195 struct common_audit_data ad;
4196 struct lsm_network_audit net = {0,};
4197 struct sockaddr_in *addr4 = NULL;
4198 struct sockaddr_in6 *addr6 = NULL;
4199 unsigned short snum;
4200 u32 sid, perm;
4201
4202 if (sk->sk_family == PF_INET) {
4203 addr4 = (struct sockaddr_in *)address;
4204 if (addrlen < sizeof(struct sockaddr_in))
4205 return -EINVAL;
4206 snum = ntohs(addr4->sin_port);
4207 } else {
4208 addr6 = (struct sockaddr_in6 *)address;
4209 if (addrlen < SIN6_LEN_RFC2133)
4210 return -EINVAL;
4211 snum = ntohs(addr6->sin6_port);
4212 }
4213
4214 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
4215 if (err)
4216 goto out;
4217
4218 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
4219 TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
4220
4221 ad.type = LSM_AUDIT_DATA_NET;
4222 ad.u.net = &net;
4223 ad.u.net->dport = htons(snum);
4224 ad.u.net->family = sk->sk_family;
4225 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
4226 if (err)
4227 goto out;
4228 }
4229
4230 err = selinux_netlbl_socket_connect(sk, address);
4231
4232 out:
4233 return err;
4234 }
4235
4236 static int selinux_socket_listen(struct socket *sock, int backlog)
4237 {
4238 return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
4239 }
4240
4241 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
4242 {
4243 int err;
4244 struct inode_security_struct *isec;
4245 struct inode_security_struct *newisec;
4246
4247 err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
4248 if (err)
4249 return err;
4250
4251 newisec = SOCK_INODE(newsock)->i_security;
4252
4253 isec = SOCK_INODE(sock)->i_security;
4254 newisec->sclass = isec->sclass;
4255 newisec->sid = isec->sid;
4256 newisec->initialized = 1;
4257
4258 return 0;
4259 }
4260
4261 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4262 int size)
4263 {
4264 return sock_has_perm(current, sock->sk, SOCKET__WRITE);
4265 }
4266
4267 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4268 int size, int flags)
4269 {
4270 return sock_has_perm(current, sock->sk, SOCKET__READ);
4271 }
4272
4273 static int selinux_socket_getsockname(struct socket *sock)
4274 {
4275 return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4276 }
4277
4278 static int selinux_socket_getpeername(struct socket *sock)
4279 {
4280 return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4281 }
4282
4283 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4284 {
4285 int err;
4286
4287 err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
4288 if (err)
4289 return err;
4290
4291 return selinux_netlbl_socket_setsockopt(sock, level, optname);
4292 }
4293
4294 static int selinux_socket_getsockopt(struct socket *sock, int level,
4295 int optname)
4296 {
4297 return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
4298 }
4299
4300 static int selinux_socket_shutdown(struct socket *sock, int how)
4301 {
4302 return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
4303 }
4304
4305 static int selinux_socket_unix_stream_connect(struct sock *sock,
4306 struct sock *other,
4307 struct sock *newsk)
4308 {
4309 struct sk_security_struct *sksec_sock = sock->sk_security;
4310 struct sk_security_struct *sksec_other = other->sk_security;
4311 struct sk_security_struct *sksec_new = newsk->sk_security;
4312 struct common_audit_data ad;
4313 struct lsm_network_audit net = {0,};
4314 int err;
4315
4316 ad.type = LSM_AUDIT_DATA_NET;
4317 ad.u.net = &net;
4318 ad.u.net->sk = other;
4319
4320 err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
4321 sksec_other->sclass,
4322 UNIX_STREAM_SOCKET__CONNECTTO, &ad);
4323 if (err)
4324 return err;
4325
4326 /* server child socket */
4327 sksec_new->peer_sid = sksec_sock->sid;
4328 err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
4329 &sksec_new->sid);
4330 if (err)
4331 return err;
4332
4333 /* connecting socket */
4334 sksec_sock->peer_sid = sksec_new->sid;
4335
4336 return 0;
4337 }
4338
4339 static int selinux_socket_unix_may_send(struct socket *sock,
4340 struct socket *other)
4341 {
4342 struct sk_security_struct *ssec = sock->sk->sk_security;
4343 struct sk_security_struct *osec = other->sk->sk_security;
4344 struct common_audit_data ad;
4345 struct lsm_network_audit net = {0,};
4346
4347 ad.type = LSM_AUDIT_DATA_NET;
4348 ad.u.net = &net;
4349 ad.u.net->sk = other->sk;
4350
4351 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
4352 &ad);
4353 }
4354
4355 static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
4356 char *addrp, u16 family, u32 peer_sid,
4357 struct common_audit_data *ad)
4358 {
4359 int err;
4360 u32 if_sid;
4361 u32 node_sid;
4362
4363 err = sel_netif_sid(ns, ifindex, &if_sid);
4364 if (err)
4365 return err;
4366 err = avc_has_perm(peer_sid, if_sid,
4367 SECCLASS_NETIF, NETIF__INGRESS, ad);
4368 if (err)
4369 return err;
4370
4371 err = sel_netnode_sid(addrp, family, &node_sid);
4372 if (err)
4373 return err;
4374 return avc_has_perm(peer_sid, node_sid,
4375 SECCLASS_NODE, NODE__RECVFROM, ad);
4376 }
4377
4378 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4379 u16 family)
4380 {
4381 int err = 0;
4382 struct sk_security_struct *sksec = sk->sk_security;
4383 u32 sk_sid = sksec->sid;
4384 struct common_audit_data ad;
4385 struct lsm_network_audit net = {0,};
4386 char *addrp;
4387
4388 ad.type = LSM_AUDIT_DATA_NET;
4389 ad.u.net = &net;
4390 ad.u.net->netif = skb->skb_iif;
4391 ad.u.net->family = family;
4392 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4393 if (err)
4394 return err;
4395
4396 if (selinux_secmark_enabled()) {
4397 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4398 PACKET__RECV, &ad);
4399 if (err)
4400 return err;
4401 }
4402
4403 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4404 if (err)
4405 return err;
4406 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4407
4408 return err;
4409 }
4410
4411 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4412 {
4413 int err;
4414 struct sk_security_struct *sksec = sk->sk_security;
4415 u16 family = sk->sk_family;
4416 u32 sk_sid = sksec->sid;
4417 struct common_audit_data ad;
4418 struct lsm_network_audit net = {0,};
4419 char *addrp;
4420 u8 secmark_active;
4421 u8 peerlbl_active;
4422
4423 if (family != PF_INET && family != PF_INET6)
4424 return 0;
4425
4426 /* Handle mapped IPv4 packets arriving via IPv6 sockets */
4427 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4428 family = PF_INET;
4429
4430 /* If any sort of compatibility mode is enabled then handoff processing
4431 * to the selinux_sock_rcv_skb_compat() function to deal with the
4432 * special handling. We do this in an attempt to keep this function
4433 * as fast and as clean as possible. */
4434 if (!selinux_policycap_netpeer)
4435 return selinux_sock_rcv_skb_compat(sk, skb, family);
4436
4437 secmark_active = selinux_secmark_enabled();
4438 peerlbl_active = selinux_peerlbl_enabled();
4439 if (!secmark_active && !peerlbl_active)
4440 return 0;
4441
4442 ad.type = LSM_AUDIT_DATA_NET;
4443 ad.u.net = &net;
4444 ad.u.net->netif = skb->skb_iif;
4445 ad.u.net->family = family;
4446 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4447 if (err)
4448 return err;
4449
4450 if (peerlbl_active) {
4451 u32 peer_sid;
4452
4453 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4454 if (err)
4455 return err;
4456 err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
4457 addrp, family, peer_sid, &ad);
4458 if (err) {
4459 selinux_netlbl_err(skb, err, 0);
4460 return err;
4461 }
4462 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4463 PEER__RECV, &ad);
4464 if (err) {
4465 selinux_netlbl_err(skb, err, 0);
4466 return err;
4467 }
4468 }
4469
4470 if (secmark_active) {
4471 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4472 PACKET__RECV, &ad);
4473 if (err)
4474 return err;
4475 }
4476
4477 return err;
4478 }
4479
4480 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4481 int __user *optlen, unsigned len)
4482 {
4483 int err = 0;
4484 char *scontext;
4485 u32 scontext_len;
4486 struct sk_security_struct *sksec = sock->sk->sk_security;
4487 u32 peer_sid = SECSID_NULL;
4488
4489 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4490 sksec->sclass == SECCLASS_TCP_SOCKET)
4491 peer_sid = sksec->peer_sid;
4492 if (peer_sid == SECSID_NULL)
4493 return -ENOPROTOOPT;
4494
4495 err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4496 if (err)
4497 return err;
4498
4499 if (scontext_len > len) {
4500 err = -ERANGE;
4501 goto out_len;
4502 }
4503
4504 if (copy_to_user(optval, scontext, scontext_len))
4505 err = -EFAULT;
4506
4507 out_len:
4508 if (put_user(scontext_len, optlen))
4509 err = -EFAULT;
4510 kfree(scontext);
4511 return err;
4512 }
4513
4514 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4515 {
4516 u32 peer_secid = SECSID_NULL;
4517 u16 family;
4518
4519 if (skb && skb->protocol == htons(ETH_P_IP))
4520 family = PF_INET;
4521 else if (skb && skb->protocol == htons(ETH_P_IPV6))
4522 family = PF_INET6;
4523 else if (sock)
4524 family = sock->sk->sk_family;
4525 else
4526 goto out;
4527
4528 if (sock && family == PF_UNIX)
4529 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4530 else if (skb)
4531 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4532
4533 out:
4534 *secid = peer_secid;
4535 if (peer_secid == SECSID_NULL)
4536 return -EINVAL;
4537 return 0;
4538 }
4539
4540 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4541 {
4542 struct sk_security_struct *sksec;
4543
4544 sksec = kzalloc(sizeof(*sksec), priority);
4545 if (!sksec)
4546 return -ENOMEM;
4547
4548 sksec->peer_sid = SECINITSID_UNLABELED;
4549 sksec->sid = SECINITSID_UNLABELED;
4550 selinux_netlbl_sk_security_reset(sksec);
4551 sk->sk_security = sksec;
4552
4553 return 0;
4554 }
4555
4556 static void selinux_sk_free_security(struct sock *sk)
4557 {
4558 struct sk_security_struct *sksec = sk->sk_security;
4559
4560 sk->sk_security = NULL;
4561 selinux_netlbl_sk_security_free(sksec);
4562 kfree(sksec);
4563 }
4564
4565 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4566 {
4567 struct sk_security_struct *sksec = sk->sk_security;
4568 struct sk_security_struct *newsksec = newsk->sk_security;
4569
4570 newsksec->sid = sksec->sid;
4571 newsksec->peer_sid = sksec->peer_sid;
4572 newsksec->sclass = sksec->sclass;
4573
4574 selinux_netlbl_sk_security_reset(newsksec);
4575 }
4576
4577 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4578 {
4579 if (!sk)
4580 *secid = SECINITSID_ANY_SOCKET;
4581 else {
4582 struct sk_security_struct *sksec = sk->sk_security;
4583
4584 *secid = sksec->sid;
4585 }
4586 }
4587
4588 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4589 {
4590 struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
4591 struct sk_security_struct *sksec = sk->sk_security;
4592
4593 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4594 sk->sk_family == PF_UNIX)
4595 isec->sid = sksec->sid;
4596 sksec->sclass = isec->sclass;
4597 }
4598
4599 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4600 struct request_sock *req)
4601 {
4602 struct sk_security_struct *sksec = sk->sk_security;
4603 int err;
4604 u16 family = req->rsk_ops->family;
4605 u32 connsid;
4606 u32 peersid;
4607
4608 err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4609 if (err)
4610 return err;
4611 err = selinux_conn_sid(sksec->sid, peersid, &connsid);
4612 if (err)
4613 return err;
4614 req->secid = connsid;
4615 req->peer_secid = peersid;
4616
4617 return selinux_netlbl_inet_conn_request(req, family);
4618 }
4619
4620 static void selinux_inet_csk_clone(struct sock *newsk,
4621 const struct request_sock *req)
4622 {
4623 struct sk_security_struct *newsksec = newsk->sk_security;
4624
4625 newsksec->sid = req->secid;
4626 newsksec->peer_sid = req->peer_secid;
4627 /* NOTE: Ideally, we should also get the isec->sid for the
4628 new socket in sync, but we don't have the isec available yet.
4629 So we will wait until sock_graft to do it, by which
4630 time it will have been created and available. */
4631
4632 /* We don't need to take any sort of lock here as we are the only
4633 * thread with access to newsksec */
4634 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4635 }
4636
4637 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4638 {
4639 u16 family = sk->sk_family;
4640 struct sk_security_struct *sksec = sk->sk_security;
4641
4642 /* handle mapped IPv4 packets arriving via IPv6 sockets */
4643 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4644 family = PF_INET;
4645
4646 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4647 }
4648
4649 static void selinux_skb_owned_by(struct sk_buff *skb, struct sock *sk)
4650 {
4651 skb_set_owner_w(skb, sk);
4652 }
4653
4654 static int selinux_secmark_relabel_packet(u32 sid)
4655 {
4656 const struct task_security_struct *__tsec;
4657 u32 tsid;
4658
4659 __tsec = current_security();
4660 tsid = __tsec->sid;
4661
4662 return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
4663 }
4664
4665 static void selinux_secmark_refcount_inc(void)
4666 {
4667 atomic_inc(&selinux_secmark_refcount);
4668 }
4669
4670 static void selinux_secmark_refcount_dec(void)
4671 {
4672 atomic_dec(&selinux_secmark_refcount);
4673 }
4674
4675 static void selinux_req_classify_flow(const struct request_sock *req,
4676 struct flowi *fl)
4677 {
4678 fl->flowi_secid = req->secid;
4679 }
4680
4681 static int selinux_tun_dev_alloc_security(void **security)
4682 {
4683 struct tun_security_struct *tunsec;
4684
4685 tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL);
4686 if (!tunsec)
4687 return -ENOMEM;
4688 tunsec->sid = current_sid();
4689
4690 *security = tunsec;
4691 return 0;
4692 }
4693
4694 static void selinux_tun_dev_free_security(void *security)
4695 {
4696 kfree(security);
4697 }
4698
4699 static int selinux_tun_dev_create(void)
4700 {
4701 u32 sid = current_sid();
4702
4703 /* we aren't taking into account the "sockcreate" SID since the socket
4704 * that is being created here is not a socket in the traditional sense,
4705 * instead it is a private sock, accessible only to the kernel, and
4706 * representing a wide range of network traffic spanning multiple
4707 * connections unlike traditional sockets - check the TUN driver to
4708 * get a better understanding of why this socket is special */
4709
4710 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4711 NULL);
4712 }
4713
4714 static int selinux_tun_dev_attach_queue(void *security)
4715 {
4716 struct tun_security_struct *tunsec = security;
4717
4718 return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
4719 TUN_SOCKET__ATTACH_QUEUE, NULL);
4720 }
4721
4722 static int selinux_tun_dev_attach(struct sock *sk, void *security)
4723 {
4724 struct tun_security_struct *tunsec = security;
4725 struct sk_security_struct *sksec = sk->sk_security;
4726
4727 /* we don't currently perform any NetLabel based labeling here and it
4728 * isn't clear that we would want to do so anyway; while we could apply
4729 * labeling without the support of the TUN user the resulting labeled
4730 * traffic from the other end of the connection would almost certainly
4731 * cause confusion to the TUN user that had no idea network labeling
4732 * protocols were being used */
4733
4734 sksec->sid = tunsec->sid;
4735 sksec->sclass = SECCLASS_TUN_SOCKET;
4736
4737 return 0;
4738 }
4739
4740 static int selinux_tun_dev_open(void *security)
4741 {
4742 struct tun_security_struct *tunsec = security;
4743 u32 sid = current_sid();
4744 int err;
4745
4746 err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
4747 TUN_SOCKET__RELABELFROM, NULL);
4748 if (err)
4749 return err;
4750 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4751 TUN_SOCKET__RELABELTO, NULL);
4752 if (err)
4753 return err;
4754 tunsec->sid = sid;
4755
4756 return 0;
4757 }
4758
4759 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4760 {
4761 int err = 0;
4762 u32 perm;
4763 struct nlmsghdr *nlh;
4764 struct sk_security_struct *sksec = sk->sk_security;
4765
4766 if (skb->len < NLMSG_HDRLEN) {
4767 err = -EINVAL;
4768 goto out;
4769 }
4770 nlh = nlmsg_hdr(skb);
4771
4772 err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
4773 if (err) {
4774 if (err == -EINVAL) {
4775 printk(KERN_WARNING
4776 "SELinux: unrecognized netlink message:"
4777 " protocol=%hu nlmsg_type=%hu sclass=%hu\n",
4778 sk->sk_protocol, nlh->nlmsg_type, sksec->sclass);
4779 if (!selinux_enforcing || security_get_allow_unknown())
4780 err = 0;
4781 }
4782
4783 /* Ignore */
4784 if (err == -ENOENT)
4785 err = 0;
4786 goto out;
4787 }
4788
4789 err = sock_has_perm(current, sk, perm);
4790 out:
4791 return err;
4792 }
4793
4794 #ifdef CONFIG_NETFILTER
4795
4796 static unsigned int selinux_ip_forward(struct sk_buff *skb,
4797 const struct net_device *indev,
4798 u16 family)
4799 {
4800 int err;
4801 char *addrp;
4802 u32 peer_sid;
4803 struct common_audit_data ad;
4804 struct lsm_network_audit net = {0,};
4805 u8 secmark_active;
4806 u8 netlbl_active;
4807 u8 peerlbl_active;
4808
4809 if (!selinux_policycap_netpeer)
4810 return NF_ACCEPT;
4811
4812 secmark_active = selinux_secmark_enabled();
4813 netlbl_active = netlbl_enabled();
4814 peerlbl_active = selinux_peerlbl_enabled();
4815 if (!secmark_active && !peerlbl_active)
4816 return NF_ACCEPT;
4817
4818 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
4819 return NF_DROP;
4820
4821 ad.type = LSM_AUDIT_DATA_NET;
4822 ad.u.net = &net;
4823 ad.u.net->netif = indev->ifindex;
4824 ad.u.net->family = family;
4825 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
4826 return NF_DROP;
4827
4828 if (peerlbl_active) {
4829 err = selinux_inet_sys_rcv_skb(dev_net(indev), indev->ifindex,
4830 addrp, family, peer_sid, &ad);
4831 if (err) {
4832 selinux_netlbl_err(skb, err, 1);
4833 return NF_DROP;
4834 }
4835 }
4836
4837 if (secmark_active)
4838 if (avc_has_perm(peer_sid, skb->secmark,
4839 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
4840 return NF_DROP;
4841
4842 if (netlbl_active)
4843 /* we do this in the FORWARD path and not the POST_ROUTING
4844 * path because we want to make sure we apply the necessary
4845 * labeling before IPsec is applied so we can leverage AH
4846 * protection */
4847 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
4848 return NF_DROP;
4849
4850 return NF_ACCEPT;
4851 }
4852
4853 static unsigned int selinux_ipv4_forward(const struct nf_hook_ops *ops,
4854 struct sk_buff *skb,
4855 const struct net_device *in,
4856 const struct net_device *out,
4857 int (*okfn)(struct sk_buff *))
4858 {
4859 return selinux_ip_forward(skb, in, PF_INET);
4860 }
4861
4862 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4863 static unsigned int selinux_ipv6_forward(const struct nf_hook_ops *ops,
4864 struct sk_buff *skb,
4865 const struct net_device *in,
4866 const struct net_device *out,
4867 int (*okfn)(struct sk_buff *))
4868 {
4869 return selinux_ip_forward(skb, in, PF_INET6);
4870 }
4871 #endif /* IPV6 */
4872
4873 static unsigned int selinux_ip_output(struct sk_buff *skb,
4874 u16 family)
4875 {
4876 struct sock *sk;
4877 u32 sid;
4878
4879 if (!netlbl_enabled())
4880 return NF_ACCEPT;
4881
4882 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
4883 * because we want to make sure we apply the necessary labeling
4884 * before IPsec is applied so we can leverage AH protection */
4885 sk = skb->sk;
4886 if (sk) {
4887 struct sk_security_struct *sksec;
4888
4889 if (sk->sk_state == TCP_LISTEN)
4890 /* if the socket is the listening state then this
4891 * packet is a SYN-ACK packet which means it needs to
4892 * be labeled based on the connection/request_sock and
4893 * not the parent socket. unfortunately, we can't
4894 * lookup the request_sock yet as it isn't queued on
4895 * the parent socket until after the SYN-ACK is sent.
4896 * the "solution" is to simply pass the packet as-is
4897 * as any IP option based labeling should be copied
4898 * from the initial connection request (in the IP
4899 * layer). it is far from ideal, but until we get a
4900 * security label in the packet itself this is the
4901 * best we can do. */
4902 return NF_ACCEPT;
4903
4904 /* standard practice, label using the parent socket */
4905 sksec = sk->sk_security;
4906 sid = sksec->sid;
4907 } else
4908 sid = SECINITSID_KERNEL;
4909 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
4910 return NF_DROP;
4911
4912 return NF_ACCEPT;
4913 }
4914
4915 static unsigned int selinux_ipv4_output(const struct nf_hook_ops *ops,
4916 struct sk_buff *skb,
4917 const struct net_device *in,
4918 const struct net_device *out,
4919 int (*okfn)(struct sk_buff *))
4920 {
4921 return selinux_ip_output(skb, PF_INET);
4922 }
4923
4924 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
4925 int ifindex,
4926 u16 family)
4927 {
4928 struct sock *sk = skb->sk;
4929 struct sk_security_struct *sksec;
4930 struct common_audit_data ad;
4931 struct lsm_network_audit net = {0,};
4932 char *addrp;
4933 u8 proto;
4934
4935 if (sk == NULL)
4936 return NF_ACCEPT;
4937 sksec = sk->sk_security;
4938
4939 ad.type = LSM_AUDIT_DATA_NET;
4940 ad.u.net = &net;
4941 ad.u.net->netif = ifindex;
4942 ad.u.net->family = family;
4943 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
4944 return NF_DROP;
4945
4946 if (selinux_secmark_enabled())
4947 if (avc_has_perm(sksec->sid, skb->secmark,
4948 SECCLASS_PACKET, PACKET__SEND, &ad))
4949 return NF_DROP_ERR(-ECONNREFUSED);
4950
4951 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
4952 return NF_DROP_ERR(-ECONNREFUSED);
4953
4954 return NF_ACCEPT;
4955 }
4956
4957 static unsigned int selinux_ip_postroute(struct sk_buff *skb,
4958 const struct net_device *outdev,
4959 u16 family)
4960 {
4961 u32 secmark_perm;
4962 u32 peer_sid;
4963 int ifindex = outdev->ifindex;
4964 struct sock *sk;
4965 struct common_audit_data ad;
4966 struct lsm_network_audit net = {0,};
4967 char *addrp;
4968 u8 secmark_active;
4969 u8 peerlbl_active;
4970
4971 /* If any sort of compatibility mode is enabled then handoff processing
4972 * to the selinux_ip_postroute_compat() function to deal with the
4973 * special handling. We do this in an attempt to keep this function
4974 * as fast and as clean as possible. */
4975 if (!selinux_policycap_netpeer)
4976 return selinux_ip_postroute_compat(skb, ifindex, family);
4977
4978 secmark_active = selinux_secmark_enabled();
4979 peerlbl_active = selinux_peerlbl_enabled();
4980 if (!secmark_active && !peerlbl_active)
4981 return NF_ACCEPT;
4982
4983 sk = skb->sk;
4984
4985 #ifdef CONFIG_XFRM
4986 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
4987 * packet transformation so allow the packet to pass without any checks
4988 * since we'll have another chance to perform access control checks
4989 * when the packet is on it's final way out.
4990 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
4991 * is NULL, in this case go ahead and apply access control.
4992 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
4993 * TCP listening state we cannot wait until the XFRM processing
4994 * is done as we will miss out on the SA label if we do;
4995 * unfortunately, this means more work, but it is only once per
4996 * connection. */
4997 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
4998 !(sk != NULL && sk->sk_state == TCP_LISTEN))
4999 return NF_ACCEPT;
5000 #endif
5001
5002 if (sk == NULL) {
5003 /* Without an associated socket the packet is either coming
5004 * from the kernel or it is being forwarded; check the packet
5005 * to determine which and if the packet is being forwarded
5006 * query the packet directly to determine the security label. */
5007 if (skb->skb_iif) {
5008 secmark_perm = PACKET__FORWARD_OUT;
5009 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5010 return NF_DROP;
5011 } else {
5012 secmark_perm = PACKET__SEND;
5013 peer_sid = SECINITSID_KERNEL;
5014 }
5015 } else if (sk->sk_state == TCP_LISTEN) {
5016 /* Locally generated packet but the associated socket is in the
5017 * listening state which means this is a SYN-ACK packet. In
5018 * this particular case the correct security label is assigned
5019 * to the connection/request_sock but unfortunately we can't
5020 * query the request_sock as it isn't queued on the parent
5021 * socket until after the SYN-ACK packet is sent; the only
5022 * viable choice is to regenerate the label like we do in
5023 * selinux_inet_conn_request(). See also selinux_ip_output()
5024 * for similar problems. */
5025 u32 skb_sid;
5026 struct sk_security_struct *sksec = sk->sk_security;
5027 if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
5028 return NF_DROP;
5029 /* At this point, if the returned skb peerlbl is SECSID_NULL
5030 * and the packet has been through at least one XFRM
5031 * transformation then we must be dealing with the "final"
5032 * form of labeled IPsec packet; since we've already applied
5033 * all of our access controls on this packet we can safely
5034 * pass the packet. */
5035 if (skb_sid == SECSID_NULL) {
5036 switch (family) {
5037 case PF_INET:
5038 if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
5039 return NF_ACCEPT;
5040 break;
5041 case PF_INET6:
5042 if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
5043 return NF_ACCEPT;
5044 break;
5045 default:
5046 return NF_DROP_ERR(-ECONNREFUSED);
5047 }
5048 }
5049 if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
5050 return NF_DROP;
5051 secmark_perm = PACKET__SEND;
5052 } else {
5053 /* Locally generated packet, fetch the security label from the
5054 * associated socket. */
5055 struct sk_security_struct *sksec = sk->sk_security;
5056 peer_sid = sksec->sid;
5057 secmark_perm = PACKET__SEND;
5058 }
5059
5060 ad.type = LSM_AUDIT_DATA_NET;
5061 ad.u.net = &net;
5062 ad.u.net->netif = ifindex;
5063 ad.u.net->family = family;
5064 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5065 return NF_DROP;
5066
5067 if (secmark_active)
5068 if (avc_has_perm(peer_sid, skb->secmark,
5069 SECCLASS_PACKET, secmark_perm, &ad))
5070 return NF_DROP_ERR(-ECONNREFUSED);
5071
5072 if (peerlbl_active) {
5073 u32 if_sid;
5074 u32 node_sid;
5075
5076 if (sel_netif_sid(dev_net(outdev), ifindex, &if_sid))
5077 return NF_DROP;
5078 if (avc_has_perm(peer_sid, if_sid,
5079 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5080 return NF_DROP_ERR(-ECONNREFUSED);
5081
5082 if (sel_netnode_sid(addrp, family, &node_sid))
5083 return NF_DROP;
5084 if (avc_has_perm(peer_sid, node_sid,
5085 SECCLASS_NODE, NODE__SENDTO, &ad))
5086 return NF_DROP_ERR(-ECONNREFUSED);
5087 }
5088
5089 return NF_ACCEPT;
5090 }
5091
5092 static unsigned int selinux_ipv4_postroute(const struct nf_hook_ops *ops,
5093 struct sk_buff *skb,
5094 const struct net_device *in,
5095 const struct net_device *out,
5096 int (*okfn)(struct sk_buff *))
5097 {
5098 return selinux_ip_postroute(skb, out, PF_INET);
5099 }
5100
5101 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5102 static unsigned int selinux_ipv6_postroute(const struct nf_hook_ops *ops,
5103 struct sk_buff *skb,
5104 const struct net_device *in,
5105 const struct net_device *out,
5106 int (*okfn)(struct sk_buff *))
5107 {
5108 return selinux_ip_postroute(skb, out, PF_INET6);
5109 }
5110 #endif /* IPV6 */
5111
5112 #endif /* CONFIG_NETFILTER */
5113
5114 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
5115 {
5116 int err;
5117
5118 err = cap_netlink_send(sk, skb);
5119 if (err)
5120 return err;
5121
5122 return selinux_nlmsg_perm(sk, skb);
5123 }
5124
5125 static int ipc_alloc_security(struct task_struct *task,
5126 struct kern_ipc_perm *perm,
5127 u16 sclass)
5128 {
5129 struct ipc_security_struct *isec;
5130 u32 sid;
5131
5132 isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
5133 if (!isec)
5134 return -ENOMEM;
5135
5136 sid = task_sid(task);
5137 isec->sclass = sclass;
5138 isec->sid = sid;
5139 perm->security = isec;
5140
5141 return 0;
5142 }
5143
5144 static void ipc_free_security(struct kern_ipc_perm *perm)
5145 {
5146 struct ipc_security_struct *isec = perm->security;
5147 perm->security = NULL;
5148 kfree(isec);
5149 }
5150
5151 static int msg_msg_alloc_security(struct msg_msg *msg)
5152 {
5153 struct msg_security_struct *msec;
5154
5155 msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
5156 if (!msec)
5157 return -ENOMEM;
5158
5159 msec->sid = SECINITSID_UNLABELED;
5160 msg->security = msec;
5161
5162 return 0;
5163 }
5164
5165 static void msg_msg_free_security(struct msg_msg *msg)
5166 {
5167 struct msg_security_struct *msec = msg->security;
5168
5169 msg->security = NULL;
5170 kfree(msec);
5171 }
5172
5173 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
5174 u32 perms)
5175 {
5176 struct ipc_security_struct *isec;
5177 struct common_audit_data ad;
5178 u32 sid = current_sid();
5179
5180 isec = ipc_perms->security;
5181
5182 ad.type = LSM_AUDIT_DATA_IPC;
5183 ad.u.ipc_id = ipc_perms->key;
5184
5185 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
5186 }
5187
5188 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
5189 {
5190 return msg_msg_alloc_security(msg);
5191 }
5192
5193 static void selinux_msg_msg_free_security(struct msg_msg *msg)
5194 {
5195 msg_msg_free_security(msg);
5196 }
5197
5198 /* message queue security operations */
5199 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
5200 {
5201 struct ipc_security_struct *isec;
5202 struct common_audit_data ad;
5203 u32 sid = current_sid();
5204 int rc;
5205
5206 rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
5207 if (rc)
5208 return rc;
5209
5210 isec = msq->q_perm.security;
5211
5212 ad.type = LSM_AUDIT_DATA_IPC;
5213 ad.u.ipc_id = msq->q_perm.key;
5214
5215 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5216 MSGQ__CREATE, &ad);
5217 if (rc) {
5218 ipc_free_security(&msq->q_perm);
5219 return rc;
5220 }
5221 return 0;
5222 }
5223
5224 static void selinux_msg_queue_free_security(struct msg_queue *msq)
5225 {
5226 ipc_free_security(&msq->q_perm);
5227 }
5228
5229 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
5230 {
5231 struct ipc_security_struct *isec;
5232 struct common_audit_data ad;
5233 u32 sid = current_sid();
5234
5235 isec = msq->q_perm.security;
5236
5237 ad.type = LSM_AUDIT_DATA_IPC;
5238 ad.u.ipc_id = msq->q_perm.key;
5239
5240 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5241 MSGQ__ASSOCIATE, &ad);
5242 }
5243
5244 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
5245 {
5246 int err;
5247 int perms;
5248
5249 switch (cmd) {
5250 case IPC_INFO:
5251 case MSG_INFO:
5252 /* No specific object, just general system-wide information. */
5253 return task_has_system(current, SYSTEM__IPC_INFO);
5254 case IPC_STAT:
5255 case MSG_STAT:
5256 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
5257 break;
5258 case IPC_SET:
5259 perms = MSGQ__SETATTR;
5260 break;
5261 case IPC_RMID:
5262 perms = MSGQ__DESTROY;
5263 break;
5264 default:
5265 return 0;
5266 }
5267
5268 err = ipc_has_perm(&msq->q_perm, perms);
5269 return err;
5270 }
5271
5272 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
5273 {
5274 struct ipc_security_struct *isec;
5275 struct msg_security_struct *msec;
5276 struct common_audit_data ad;
5277 u32 sid = current_sid();
5278 int rc;
5279
5280 isec = msq->q_perm.security;
5281 msec = msg->security;
5282
5283 /*
5284 * First time through, need to assign label to the message
5285 */
5286 if (msec->sid == SECINITSID_UNLABELED) {
5287 /*
5288 * Compute new sid based on current process and
5289 * message queue this message will be stored in
5290 */
5291 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
5292 NULL, &msec->sid);
5293 if (rc)
5294 return rc;
5295 }
5296
5297 ad.type = LSM_AUDIT_DATA_IPC;
5298 ad.u.ipc_id = msq->q_perm.key;
5299
5300 /* Can this process write to the queue? */
5301 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5302 MSGQ__WRITE, &ad);
5303 if (!rc)
5304 /* Can this process send the message */
5305 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
5306 MSG__SEND, &ad);
5307 if (!rc)
5308 /* Can the message be put in the queue? */
5309 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
5310 MSGQ__ENQUEUE, &ad);
5311
5312 return rc;
5313 }
5314
5315 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
5316 struct task_struct *target,
5317 long type, int mode)
5318 {
5319 struct ipc_security_struct *isec;
5320 struct msg_security_struct *msec;
5321 struct common_audit_data ad;
5322 u32 sid = task_sid(target);
5323 int rc;
5324
5325 isec = msq->q_perm.security;
5326 msec = msg->security;
5327
5328 ad.type = LSM_AUDIT_DATA_IPC;
5329 ad.u.ipc_id = msq->q_perm.key;
5330
5331 rc = avc_has_perm(sid, isec->sid,
5332 SECCLASS_MSGQ, MSGQ__READ, &ad);
5333 if (!rc)
5334 rc = avc_has_perm(sid, msec->sid,
5335 SECCLASS_MSG, MSG__RECEIVE, &ad);
5336 return rc;
5337 }
5338
5339 /* Shared Memory security operations */
5340 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
5341 {
5342 struct ipc_security_struct *isec;
5343 struct common_audit_data ad;
5344 u32 sid = current_sid();
5345 int rc;
5346
5347 rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
5348 if (rc)
5349 return rc;
5350
5351 isec = shp->shm_perm.security;
5352
5353 ad.type = LSM_AUDIT_DATA_IPC;
5354 ad.u.ipc_id = shp->shm_perm.key;
5355
5356 rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5357 SHM__CREATE, &ad);
5358 if (rc) {
5359 ipc_free_security(&shp->shm_perm);
5360 return rc;
5361 }
5362 return 0;
5363 }
5364
5365 static void selinux_shm_free_security(struct shmid_kernel *shp)
5366 {
5367 ipc_free_security(&shp->shm_perm);
5368 }
5369
5370 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
5371 {
5372 struct ipc_security_struct *isec;
5373 struct common_audit_data ad;
5374 u32 sid = current_sid();
5375
5376 isec = shp->shm_perm.security;
5377
5378 ad.type = LSM_AUDIT_DATA_IPC;
5379 ad.u.ipc_id = shp->shm_perm.key;
5380
5381 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5382 SHM__ASSOCIATE, &ad);
5383 }
5384
5385 /* Note, at this point, shp is locked down */
5386 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
5387 {
5388 int perms;
5389 int err;
5390
5391 switch (cmd) {
5392 case IPC_INFO:
5393 case SHM_INFO:
5394 /* No specific object, just general system-wide information. */
5395 return task_has_system(current, SYSTEM__IPC_INFO);
5396 case IPC_STAT:
5397 case SHM_STAT:
5398 perms = SHM__GETATTR | SHM__ASSOCIATE;
5399 break;
5400 case IPC_SET:
5401 perms = SHM__SETATTR;
5402 break;
5403 case SHM_LOCK:
5404 case SHM_UNLOCK:
5405 perms = SHM__LOCK;
5406 break;
5407 case IPC_RMID:
5408 perms = SHM__DESTROY;
5409 break;
5410 default:
5411 return 0;
5412 }
5413
5414 err = ipc_has_perm(&shp->shm_perm, perms);
5415 return err;
5416 }
5417
5418 static int selinux_shm_shmat(struct shmid_kernel *shp,
5419 char __user *shmaddr, int shmflg)
5420 {
5421 u32 perms;
5422
5423 if (shmflg & SHM_RDONLY)
5424 perms = SHM__READ;
5425 else
5426 perms = SHM__READ | SHM__WRITE;
5427
5428 return ipc_has_perm(&shp->shm_perm, perms);
5429 }
5430
5431 /* Semaphore security operations */
5432 static int selinux_sem_alloc_security(struct sem_array *sma)
5433 {
5434 struct ipc_security_struct *isec;
5435 struct common_audit_data ad;
5436 u32 sid = current_sid();
5437 int rc;
5438
5439 rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
5440 if (rc)
5441 return rc;
5442
5443 isec = sma->sem_perm.security;
5444
5445 ad.type = LSM_AUDIT_DATA_IPC;
5446 ad.u.ipc_id = sma->sem_perm.key;
5447
5448 rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5449 SEM__CREATE, &ad);
5450 if (rc) {
5451 ipc_free_security(&sma->sem_perm);
5452 return rc;
5453 }
5454 return 0;
5455 }
5456
5457 static void selinux_sem_free_security(struct sem_array *sma)
5458 {
5459 ipc_free_security(&sma->sem_perm);
5460 }
5461
5462 static int selinux_sem_associate(struct sem_array *sma, int semflg)
5463 {
5464 struct ipc_security_struct *isec;
5465 struct common_audit_data ad;
5466 u32 sid = current_sid();
5467
5468 isec = sma->sem_perm.security;
5469
5470 ad.type = LSM_AUDIT_DATA_IPC;
5471 ad.u.ipc_id = sma->sem_perm.key;
5472
5473 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5474 SEM__ASSOCIATE, &ad);
5475 }
5476
5477 /* Note, at this point, sma is locked down */
5478 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5479 {
5480 int err;
5481 u32 perms;
5482
5483 switch (cmd) {
5484 case IPC_INFO:
5485 case SEM_INFO:
5486 /* No specific object, just general system-wide information. */
5487 return task_has_system(current, SYSTEM__IPC_INFO);
5488 case GETPID:
5489 case GETNCNT:
5490 case GETZCNT:
5491 perms = SEM__GETATTR;
5492 break;
5493 case GETVAL:
5494 case GETALL:
5495 perms = SEM__READ;
5496 break;
5497 case SETVAL:
5498 case SETALL:
5499 perms = SEM__WRITE;
5500 break;
5501 case IPC_RMID:
5502 perms = SEM__DESTROY;
5503 break;
5504 case IPC_SET:
5505 perms = SEM__SETATTR;
5506 break;
5507 case IPC_STAT:
5508 case SEM_STAT:
5509 perms = SEM__GETATTR | SEM__ASSOCIATE;
5510 break;
5511 default:
5512 return 0;
5513 }
5514
5515 err = ipc_has_perm(&sma->sem_perm, perms);
5516 return err;
5517 }
5518
5519 static int selinux_sem_semop(struct sem_array *sma,
5520 struct sembuf *sops, unsigned nsops, int alter)
5521 {
5522 u32 perms;
5523
5524 if (alter)
5525 perms = SEM__READ | SEM__WRITE;
5526 else
5527 perms = SEM__READ;
5528
5529 return ipc_has_perm(&sma->sem_perm, perms);
5530 }
5531
5532 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5533 {
5534 u32 av = 0;
5535
5536 av = 0;
5537 if (flag & S_IRUGO)
5538 av |= IPC__UNIX_READ;
5539 if (flag & S_IWUGO)
5540 av |= IPC__UNIX_WRITE;
5541
5542 if (av == 0)
5543 return 0;
5544
5545 return ipc_has_perm(ipcp, av);
5546 }
5547
5548 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5549 {
5550 struct ipc_security_struct *isec = ipcp->security;
5551 *secid = isec->sid;
5552 }
5553
5554 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5555 {
5556 if (inode)
5557 inode_doinit_with_dentry(inode, dentry);
5558 }
5559
5560 static int selinux_getprocattr(struct task_struct *p,
5561 char *name, char **value)
5562 {
5563 const struct task_security_struct *__tsec;
5564 u32 sid;
5565 int error;
5566 unsigned len;
5567
5568 if (current != p) {
5569 error = current_has_perm(p, PROCESS__GETATTR);
5570 if (error)
5571 return error;
5572 }
5573
5574 rcu_read_lock();
5575 __tsec = __task_cred(p)->security;
5576
5577 if (!strcmp(name, "current"))
5578 sid = __tsec->sid;
5579 else if (!strcmp(name, "prev"))
5580 sid = __tsec->osid;
5581 else if (!strcmp(name, "exec"))
5582 sid = __tsec->exec_sid;
5583 else if (!strcmp(name, "fscreate"))
5584 sid = __tsec->create_sid;
5585 else if (!strcmp(name, "keycreate"))
5586 sid = __tsec->keycreate_sid;
5587 else if (!strcmp(name, "sockcreate"))
5588 sid = __tsec->sockcreate_sid;
5589 else
5590 goto invalid;
5591 rcu_read_unlock();
5592
5593 if (!sid)
5594 return 0;
5595
5596 error = security_sid_to_context(sid, value, &len);
5597 if (error)
5598 return error;
5599 return len;
5600
5601 invalid:
5602 rcu_read_unlock();
5603 return -EINVAL;
5604 }
5605
5606 static int selinux_setprocattr(struct task_struct *p,
5607 char *name, void *value, size_t size)
5608 {
5609 struct task_security_struct *tsec;
5610 struct task_struct *tracer;
5611 struct cred *new;
5612 u32 sid = 0, ptsid;
5613 int error;
5614 char *str = value;
5615
5616 if (current != p) {
5617 /* SELinux only allows a process to change its own
5618 security attributes. */
5619 return -EACCES;
5620 }
5621
5622 /*
5623 * Basic control over ability to set these attributes at all.
5624 * current == p, but we'll pass them separately in case the
5625 * above restriction is ever removed.
5626 */
5627 if (!strcmp(name, "exec"))
5628 error = current_has_perm(p, PROCESS__SETEXEC);
5629 else if (!strcmp(name, "fscreate"))
5630 error = current_has_perm(p, PROCESS__SETFSCREATE);
5631 else if (!strcmp(name, "keycreate"))
5632 error = current_has_perm(p, PROCESS__SETKEYCREATE);
5633 else if (!strcmp(name, "sockcreate"))
5634 error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5635 else if (!strcmp(name, "current"))
5636 error = current_has_perm(p, PROCESS__SETCURRENT);
5637 else
5638 error = -EINVAL;
5639 if (error)
5640 return error;
5641
5642 /* Obtain a SID for the context, if one was specified. */
5643 if (size && str[1] && str[1] != '\n') {
5644 if (str[size-1] == '\n') {
5645 str[size-1] = 0;
5646 size--;
5647 }
5648 error = security_context_to_sid(value, size, &sid, GFP_KERNEL);
5649 if (error == -EINVAL && !strcmp(name, "fscreate")) {
5650 if (!capable(CAP_MAC_ADMIN)) {
5651 struct audit_buffer *ab;
5652 size_t audit_size;
5653
5654 /* We strip a nul only if it is at the end, otherwise the
5655 * context contains a nul and we should audit that */
5656 if (str[size - 1] == '\0')
5657 audit_size = size - 1;
5658 else
5659 audit_size = size;
5660 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
5661 audit_log_format(ab, "op=fscreate invalid_context=");
5662 audit_log_n_untrustedstring(ab, value, audit_size);
5663 audit_log_end(ab);
5664
5665 return error;
5666 }
5667 error = security_context_to_sid_force(value, size,
5668 &sid);
5669 }
5670 if (error)
5671 return error;
5672 }
5673
5674 new = prepare_creds();
5675 if (!new)
5676 return -ENOMEM;
5677
5678 /* Permission checking based on the specified context is
5679 performed during the actual operation (execve,
5680 open/mkdir/...), when we know the full context of the
5681 operation. See selinux_bprm_set_creds for the execve
5682 checks and may_create for the file creation checks. The
5683 operation will then fail if the context is not permitted. */
5684 tsec = new->security;
5685 if (!strcmp(name, "exec")) {
5686 tsec->exec_sid = sid;
5687 } else if (!strcmp(name, "fscreate")) {
5688 tsec->create_sid = sid;
5689 } else if (!strcmp(name, "keycreate")) {
5690 error = may_create_key(sid, p);
5691 if (error)
5692 goto abort_change;
5693 tsec->keycreate_sid = sid;
5694 } else if (!strcmp(name, "sockcreate")) {
5695 tsec->sockcreate_sid = sid;
5696 } else if (!strcmp(name, "current")) {
5697 error = -EINVAL;
5698 if (sid == 0)
5699 goto abort_change;
5700
5701 /* Only allow single threaded processes to change context */
5702 error = -EPERM;
5703 if (!current_is_single_threaded()) {
5704 error = security_bounded_transition(tsec->sid, sid);
5705 if (error)
5706 goto abort_change;
5707 }
5708
5709 /* Check permissions for the transition. */
5710 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5711 PROCESS__DYNTRANSITION, NULL);
5712 if (error)
5713 goto abort_change;
5714
5715 /* Check for ptracing, and update the task SID if ok.
5716 Otherwise, leave SID unchanged and fail. */
5717 ptsid = 0;
5718 rcu_read_lock();
5719 tracer = ptrace_parent(p);
5720 if (tracer)
5721 ptsid = task_sid(tracer);
5722 rcu_read_unlock();
5723
5724 if (tracer) {
5725 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5726 PROCESS__PTRACE, NULL);
5727 if (error)
5728 goto abort_change;
5729 }
5730
5731 tsec->sid = sid;
5732 } else {
5733 error = -EINVAL;
5734 goto abort_change;
5735 }
5736
5737 commit_creds(new);
5738 return size;
5739
5740 abort_change:
5741 abort_creds(new);
5742 return error;
5743 }
5744
5745 static int selinux_ismaclabel(const char *name)
5746 {
5747 return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
5748 }
5749
5750 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5751 {
5752 return security_sid_to_context(secid, secdata, seclen);
5753 }
5754
5755 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5756 {
5757 return security_context_to_sid(secdata, seclen, secid, GFP_KERNEL);
5758 }
5759
5760 static void selinux_release_secctx(char *secdata, u32 seclen)
5761 {
5762 kfree(secdata);
5763 }
5764
5765 /*
5766 * called with inode->i_mutex locked
5767 */
5768 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5769 {
5770 return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5771 }
5772
5773 /*
5774 * called with inode->i_mutex locked
5775 */
5776 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
5777 {
5778 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
5779 }
5780
5781 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
5782 {
5783 int len = 0;
5784 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
5785 ctx, true);
5786 if (len < 0)
5787 return len;
5788 *ctxlen = len;
5789 return 0;
5790 }
5791 #ifdef CONFIG_KEYS
5792
5793 static int selinux_key_alloc(struct key *k, const struct cred *cred,
5794 unsigned long flags)
5795 {
5796 const struct task_security_struct *tsec;
5797 struct key_security_struct *ksec;
5798
5799 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
5800 if (!ksec)
5801 return -ENOMEM;
5802
5803 tsec = cred->security;
5804 if (tsec->keycreate_sid)
5805 ksec->sid = tsec->keycreate_sid;
5806 else
5807 ksec->sid = tsec->sid;
5808
5809 k->security = ksec;
5810 return 0;
5811 }
5812
5813 static void selinux_key_free(struct key *k)
5814 {
5815 struct key_security_struct *ksec = k->security;
5816
5817 k->security = NULL;
5818 kfree(ksec);
5819 }
5820
5821 static int selinux_key_permission(key_ref_t key_ref,
5822 const struct cred *cred,
5823 unsigned perm)
5824 {
5825 struct key *key;
5826 struct key_security_struct *ksec;
5827 u32 sid;
5828
5829 /* if no specific permissions are requested, we skip the
5830 permission check. No serious, additional covert channels
5831 appear to be created. */
5832 if (perm == 0)
5833 return 0;
5834
5835 sid = cred_sid(cred);
5836
5837 key = key_ref_to_ptr(key_ref);
5838 ksec = key->security;
5839
5840 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5841 }
5842
5843 static int selinux_key_getsecurity(struct key *key, char **_buffer)
5844 {
5845 struct key_security_struct *ksec = key->security;
5846 char *context = NULL;
5847 unsigned len;
5848 int rc;
5849
5850 rc = security_sid_to_context(ksec->sid, &context, &len);
5851 if (!rc)
5852 rc = len;
5853 *_buffer = context;
5854 return rc;
5855 }
5856
5857 #endif
5858
5859 static struct security_operations selinux_ops = {
5860 .name = "selinux",
5861
5862 .binder_set_context_mgr = selinux_binder_set_context_mgr,
5863 .binder_transaction = selinux_binder_transaction,
5864 .binder_transfer_binder = selinux_binder_transfer_binder,
5865 .binder_transfer_file = selinux_binder_transfer_file,
5866
5867 .ptrace_access_check = selinux_ptrace_access_check,
5868 .ptrace_traceme = selinux_ptrace_traceme,
5869 .capget = selinux_capget,
5870 .capset = selinux_capset,
5871 .capable = selinux_capable,
5872 .quotactl = selinux_quotactl,
5873 .quota_on = selinux_quota_on,
5874 .syslog = selinux_syslog,
5875 .vm_enough_memory = selinux_vm_enough_memory,
5876
5877 .netlink_send = selinux_netlink_send,
5878
5879 .bprm_set_creds = selinux_bprm_set_creds,
5880 .bprm_committing_creds = selinux_bprm_committing_creds,
5881 .bprm_committed_creds = selinux_bprm_committed_creds,
5882 .bprm_secureexec = selinux_bprm_secureexec,
5883
5884 .sb_alloc_security = selinux_sb_alloc_security,
5885 .sb_free_security = selinux_sb_free_security,
5886 .sb_copy_data = selinux_sb_copy_data,
5887 .sb_remount = selinux_sb_remount,
5888 .sb_kern_mount = selinux_sb_kern_mount,
5889 .sb_show_options = selinux_sb_show_options,
5890 .sb_statfs = selinux_sb_statfs,
5891 .sb_mount = selinux_mount,
5892 .sb_umount = selinux_umount,
5893 .sb_set_mnt_opts = selinux_set_mnt_opts,
5894 .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts,
5895 .sb_parse_opts_str = selinux_parse_opts_str,
5896
5897 .dentry_init_security = selinux_dentry_init_security,
5898
5899 .inode_alloc_security = selinux_inode_alloc_security,
5900 .inode_free_security = selinux_inode_free_security,
5901 .inode_init_security = selinux_inode_init_security,
5902 .inode_create = selinux_inode_create,
5903 .inode_link = selinux_inode_link,
5904 .inode_unlink = selinux_inode_unlink,
5905 .inode_symlink = selinux_inode_symlink,
5906 .inode_mkdir = selinux_inode_mkdir,
5907 .inode_rmdir = selinux_inode_rmdir,
5908 .inode_mknod = selinux_inode_mknod,
5909 .inode_rename = selinux_inode_rename,
5910 .inode_readlink = selinux_inode_readlink,
5911 .inode_follow_link = selinux_inode_follow_link,
5912 .inode_permission = selinux_inode_permission,
5913 .inode_setattr = selinux_inode_setattr,
5914 .inode_getattr = selinux_inode_getattr,
5915 .inode_setxattr = selinux_inode_setxattr,
5916 .inode_post_setxattr = selinux_inode_post_setxattr,
5917 .inode_getxattr = selinux_inode_getxattr,
5918 .inode_listxattr = selinux_inode_listxattr,
5919 .inode_removexattr = selinux_inode_removexattr,
5920 .inode_getsecurity = selinux_inode_getsecurity,
5921 .inode_setsecurity = selinux_inode_setsecurity,
5922 .inode_listsecurity = selinux_inode_listsecurity,
5923 .inode_getsecid = selinux_inode_getsecid,
5924
5925 .file_permission = selinux_file_permission,
5926 .file_alloc_security = selinux_file_alloc_security,
5927 .file_free_security = selinux_file_free_security,
5928 .file_ioctl = selinux_file_ioctl,
5929 .mmap_file = selinux_mmap_file,
5930 .mmap_addr = selinux_mmap_addr,
5931 .file_mprotect = selinux_file_mprotect,
5932 .file_lock = selinux_file_lock,
5933 .file_fcntl = selinux_file_fcntl,
5934 .file_set_fowner = selinux_file_set_fowner,
5935 .file_send_sigiotask = selinux_file_send_sigiotask,
5936 .file_receive = selinux_file_receive,
5937
5938 .file_open = selinux_file_open,
5939
5940 .task_create = selinux_task_create,
5941 .cred_alloc_blank = selinux_cred_alloc_blank,
5942 .cred_free = selinux_cred_free,
5943 .cred_prepare = selinux_cred_prepare,
5944 .cred_transfer = selinux_cred_transfer,
5945 .kernel_act_as = selinux_kernel_act_as,
5946 .kernel_create_files_as = selinux_kernel_create_files_as,
5947 .kernel_module_request = selinux_kernel_module_request,
5948 .task_setpgid = selinux_task_setpgid,
5949 .task_getpgid = selinux_task_getpgid,
5950 .task_getsid = selinux_task_getsid,
5951 .task_getsecid = selinux_task_getsecid,
5952 .task_setnice = selinux_task_setnice,
5953 .task_setioprio = selinux_task_setioprio,
5954 .task_getioprio = selinux_task_getioprio,
5955 .task_setrlimit = selinux_task_setrlimit,
5956 .task_setscheduler = selinux_task_setscheduler,
5957 .task_getscheduler = selinux_task_getscheduler,
5958 .task_movememory = selinux_task_movememory,
5959 .task_kill = selinux_task_kill,
5960 .task_wait = selinux_task_wait,
5961 .task_to_inode = selinux_task_to_inode,
5962
5963 .ipc_permission = selinux_ipc_permission,
5964 .ipc_getsecid = selinux_ipc_getsecid,
5965
5966 .msg_msg_alloc_security = selinux_msg_msg_alloc_security,
5967 .msg_msg_free_security = selinux_msg_msg_free_security,
5968
5969 .msg_queue_alloc_security = selinux_msg_queue_alloc_security,
5970 .msg_queue_free_security = selinux_msg_queue_free_security,
5971 .msg_queue_associate = selinux_msg_queue_associate,
5972 .msg_queue_msgctl = selinux_msg_queue_msgctl,
5973 .msg_queue_msgsnd = selinux_msg_queue_msgsnd,
5974 .msg_queue_msgrcv = selinux_msg_queue_msgrcv,
5975
5976 .shm_alloc_security = selinux_shm_alloc_security,
5977 .shm_free_security = selinux_shm_free_security,
5978 .shm_associate = selinux_shm_associate,
5979 .shm_shmctl = selinux_shm_shmctl,
5980 .shm_shmat = selinux_shm_shmat,
5981
5982 .sem_alloc_security = selinux_sem_alloc_security,
5983 .sem_free_security = selinux_sem_free_security,
5984 .sem_associate = selinux_sem_associate,
5985 .sem_semctl = selinux_sem_semctl,
5986 .sem_semop = selinux_sem_semop,
5987
5988 .d_instantiate = selinux_d_instantiate,
5989
5990 .getprocattr = selinux_getprocattr,
5991 .setprocattr = selinux_setprocattr,
5992
5993 .ismaclabel = selinux_ismaclabel,
5994 .secid_to_secctx = selinux_secid_to_secctx,
5995 .secctx_to_secid = selinux_secctx_to_secid,
5996 .release_secctx = selinux_release_secctx,
5997 .inode_notifysecctx = selinux_inode_notifysecctx,
5998 .inode_setsecctx = selinux_inode_setsecctx,
5999 .inode_getsecctx = selinux_inode_getsecctx,
6000
6001 .unix_stream_connect = selinux_socket_unix_stream_connect,
6002 .unix_may_send = selinux_socket_unix_may_send,
6003
6004 .socket_create = selinux_socket_create,
6005 .socket_post_create = selinux_socket_post_create,
6006 .socket_bind = selinux_socket_bind,
6007 .socket_connect = selinux_socket_connect,
6008 .socket_listen = selinux_socket_listen,
6009 .socket_accept = selinux_socket_accept,
6010 .socket_sendmsg = selinux_socket_sendmsg,
6011 .socket_recvmsg = selinux_socket_recvmsg,
6012 .socket_getsockname = selinux_socket_getsockname,
6013 .socket_getpeername = selinux_socket_getpeername,
6014 .socket_getsockopt = selinux_socket_getsockopt,
6015 .socket_setsockopt = selinux_socket_setsockopt,
6016 .socket_shutdown = selinux_socket_shutdown,
6017 .socket_sock_rcv_skb = selinux_socket_sock_rcv_skb,
6018 .socket_getpeersec_stream = selinux_socket_getpeersec_stream,
6019 .socket_getpeersec_dgram = selinux_socket_getpeersec_dgram,
6020 .sk_alloc_security = selinux_sk_alloc_security,
6021 .sk_free_security = selinux_sk_free_security,
6022 .sk_clone_security = selinux_sk_clone_security,
6023 .sk_getsecid = selinux_sk_getsecid,
6024 .sock_graft = selinux_sock_graft,
6025 .inet_conn_request = selinux_inet_conn_request,
6026 .inet_csk_clone = selinux_inet_csk_clone,
6027 .inet_conn_established = selinux_inet_conn_established,
6028 .secmark_relabel_packet = selinux_secmark_relabel_packet,
6029 .secmark_refcount_inc = selinux_secmark_refcount_inc,
6030 .secmark_refcount_dec = selinux_secmark_refcount_dec,
6031 .req_classify_flow = selinux_req_classify_flow,
6032 .tun_dev_alloc_security = selinux_tun_dev_alloc_security,
6033 .tun_dev_free_security = selinux_tun_dev_free_security,
6034 .tun_dev_create = selinux_tun_dev_create,
6035 .tun_dev_attach_queue = selinux_tun_dev_attach_queue,
6036 .tun_dev_attach = selinux_tun_dev_attach,
6037 .tun_dev_open = selinux_tun_dev_open,
6038 .skb_owned_by = selinux_skb_owned_by,
6039
6040 #ifdef CONFIG_SECURITY_NETWORK_XFRM
6041 .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc,
6042 .xfrm_policy_clone_security = selinux_xfrm_policy_clone,
6043 .xfrm_policy_free_security = selinux_xfrm_policy_free,
6044 .xfrm_policy_delete_security = selinux_xfrm_policy_delete,
6045 .xfrm_state_alloc = selinux_xfrm_state_alloc,
6046 .xfrm_state_alloc_acquire = selinux_xfrm_state_alloc_acquire,
6047 .xfrm_state_free_security = selinux_xfrm_state_free,
6048 .xfrm_state_delete_security = selinux_xfrm_state_delete,
6049 .xfrm_policy_lookup = selinux_xfrm_policy_lookup,
6050 .xfrm_state_pol_flow_match = selinux_xfrm_state_pol_flow_match,
6051 .xfrm_decode_session = selinux_xfrm_decode_session,
6052 #endif
6053
6054 #ifdef CONFIG_KEYS
6055 .key_alloc = selinux_key_alloc,
6056 .key_free = selinux_key_free,
6057 .key_permission = selinux_key_permission,
6058 .key_getsecurity = selinux_key_getsecurity,
6059 #endif
6060
6061 #ifdef CONFIG_AUDIT
6062 .audit_rule_init = selinux_audit_rule_init,
6063 .audit_rule_known = selinux_audit_rule_known,
6064 .audit_rule_match = selinux_audit_rule_match,
6065 .audit_rule_free = selinux_audit_rule_free,
6066 #endif
6067 };
6068
6069 static __init int selinux_init(void)
6070 {
6071 if (!security_module_enable(&selinux_ops)) {
6072 selinux_enabled = 0;
6073 return 0;
6074 }
6075
6076 if (!selinux_enabled) {
6077 printk(KERN_INFO "SELinux: Disabled at boot.\n");
6078 return 0;
6079 }
6080
6081 printk(KERN_INFO "SELinux: Initializing.\n");
6082
6083 /* Set the security state for the initial task. */
6084 cred_init_security();
6085
6086 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
6087
6088 sel_inode_cache = kmem_cache_create("selinux_inode_security",
6089 sizeof(struct inode_security_struct),
6090 0, SLAB_PANIC, NULL);
6091 avc_init();
6092
6093 if (register_security(&selinux_ops))
6094 panic("SELinux: Unable to register with kernel.\n");
6095
6096 if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
6097 panic("SELinux: Unable to register AVC netcache callback\n");
6098
6099 if (selinux_enforcing)
6100 printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n");
6101 else
6102 printk(KERN_DEBUG "SELinux: Starting in permissive mode\n");
6103
6104 return 0;
6105 }
6106
6107 static void delayed_superblock_init(struct super_block *sb, void *unused)
6108 {
6109 superblock_doinit(sb, NULL);
6110 }
6111
6112 void selinux_complete_init(void)
6113 {
6114 printk(KERN_DEBUG "SELinux: Completing initialization.\n");
6115
6116 /* Set up any superblocks initialized prior to the policy load. */
6117 printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n");
6118 iterate_supers(delayed_superblock_init, NULL);
6119 }
6120
6121 /* SELinux requires early initialization in order to label
6122 all processes and objects when they are created. */
6123 security_initcall(selinux_init);
6124
6125 #if defined(CONFIG_NETFILTER)
6126
6127 static struct nf_hook_ops selinux_nf_ops[] = {
6128 {
6129 .hook = selinux_ipv4_postroute,
6130 .owner = THIS_MODULE,
6131 .pf = NFPROTO_IPV4,
6132 .hooknum = NF_INET_POST_ROUTING,
6133 .priority = NF_IP_PRI_SELINUX_LAST,
6134 },
6135 {
6136 .hook = selinux_ipv4_forward,
6137 .owner = THIS_MODULE,
6138 .pf = NFPROTO_IPV4,
6139 .hooknum = NF_INET_FORWARD,
6140 .priority = NF_IP_PRI_SELINUX_FIRST,
6141 },
6142 {
6143 .hook = selinux_ipv4_output,
6144 .owner = THIS_MODULE,
6145 .pf = NFPROTO_IPV4,
6146 .hooknum = NF_INET_LOCAL_OUT,
6147 .priority = NF_IP_PRI_SELINUX_FIRST,
6148 },
6149 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
6150 {
6151 .hook = selinux_ipv6_postroute,
6152 .owner = THIS_MODULE,
6153 .pf = NFPROTO_IPV6,
6154 .hooknum = NF_INET_POST_ROUTING,
6155 .priority = NF_IP6_PRI_SELINUX_LAST,
6156 },
6157 {
6158 .hook = selinux_ipv6_forward,
6159 .owner = THIS_MODULE,
6160 .pf = NFPROTO_IPV6,
6161 .hooknum = NF_INET_FORWARD,
6162 .priority = NF_IP6_PRI_SELINUX_FIRST,
6163 },
6164 #endif /* IPV6 */
6165 };
6166
6167 static int __init selinux_nf_ip_init(void)
6168 {
6169 int err;
6170
6171 if (!selinux_enabled)
6172 return 0;
6173
6174 printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n");
6175
6176 err = nf_register_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
6177 if (err)
6178 panic("SELinux: nf_register_hooks: error %d\n", err);
6179
6180 return 0;
6181 }
6182
6183 __initcall(selinux_nf_ip_init);
6184
6185 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
6186 static void selinux_nf_ip_exit(void)
6187 {
6188 printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n");
6189
6190 nf_unregister_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
6191 }
6192 #endif
6193
6194 #else /* CONFIG_NETFILTER */
6195
6196 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
6197 #define selinux_nf_ip_exit()
6198 #endif
6199
6200 #endif /* CONFIG_NETFILTER */
6201
6202 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
6203 static int selinux_disabled;
6204
6205 int selinux_disable(void)
6206 {
6207 if (ss_initialized) {
6208 /* Not permitted after initial policy load. */
6209 return -EINVAL;
6210 }
6211
6212 if (selinux_disabled) {
6213 /* Only do this once. */
6214 return -EINVAL;
6215 }
6216
6217 printk(KERN_INFO "SELinux: Disabled at runtime.\n");
6218
6219 selinux_disabled = 1;
6220 selinux_enabled = 0;
6221
6222 reset_security_ops();
6223
6224 /* Try to destroy the avc node cache */
6225 avc_disable();
6226
6227 /* Unregister netfilter hooks. */
6228 selinux_nf_ip_exit();
6229
6230 /* Unregister selinuxfs. */
6231 exit_sel_fs();
6232
6233 return 0;
6234 }
6235 #endif
Linux kernel - Deliverables
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