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Merge branch 'for-4.1/sensor-hub' into for-linus
[mirror_ubuntu-artful-kernel.git] / security / selinux / hooks.c
1 /*
2 * NSA Security-Enhanced Linux (SELinux) security module
3 *
4 * This file contains the SELinux hook function implementations.
5 *
6 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
7 * Chris Vance, <cvance@nai.com>
8 * Wayne Salamon, <wsalamon@nai.com>
9 * James Morris <jmorris@redhat.com>
10 *
11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12 * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
13 * Eric Paris <eparis@redhat.com>
14 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
15 * <dgoeddel@trustedcs.com>
16 * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
17 * Paul Moore <paul@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 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(struct vfsmount *mnt, struct dentry *dentry)
2958 {
2959 const struct cred *cred = current_cred();
2960 struct path path;
2961
2962 path.dentry = dentry;
2963 path.mnt = mnt;
2964
2965 return path_has_perm(cred, &path, FILE__GETATTR);
2966 }
2967
2968 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2969 {
2970 const struct cred *cred = current_cred();
2971
2972 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2973 sizeof XATTR_SECURITY_PREFIX - 1)) {
2974 if (!strcmp(name, XATTR_NAME_CAPS)) {
2975 if (!capable(CAP_SETFCAP))
2976 return -EPERM;
2977 } else if (!capable(CAP_SYS_ADMIN)) {
2978 /* A different attribute in the security namespace.
2979 Restrict to administrator. */
2980 return -EPERM;
2981 }
2982 }
2983
2984 /* Not an attribute we recognize, so just check the
2985 ordinary setattr permission. */
2986 return dentry_has_perm(cred, dentry, FILE__SETATTR);
2987 }
2988
2989 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2990 const void *value, size_t size, int flags)
2991 {
2992 struct inode *inode = dentry->d_inode;
2993 struct inode_security_struct *isec = inode->i_security;
2994 struct superblock_security_struct *sbsec;
2995 struct common_audit_data ad;
2996 u32 newsid, sid = current_sid();
2997 int rc = 0;
2998
2999 if (strcmp(name, XATTR_NAME_SELINUX))
3000 return selinux_inode_setotherxattr(dentry, name);
3001
3002 sbsec = inode->i_sb->s_security;
3003 if (!(sbsec->flags & SBLABEL_MNT))
3004 return -EOPNOTSUPP;
3005
3006 if (!inode_owner_or_capable(inode))
3007 return -EPERM;
3008
3009 ad.type = LSM_AUDIT_DATA_DENTRY;
3010 ad.u.dentry = dentry;
3011
3012 rc = avc_has_perm(sid, isec->sid, isec->sclass,
3013 FILE__RELABELFROM, &ad);
3014 if (rc)
3015 return rc;
3016
3017 rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
3018 if (rc == -EINVAL) {
3019 if (!capable(CAP_MAC_ADMIN)) {
3020 struct audit_buffer *ab;
3021 size_t audit_size;
3022 const char *str;
3023
3024 /* We strip a nul only if it is at the end, otherwise the
3025 * context contains a nul and we should audit that */
3026 if (value) {
3027 str = value;
3028 if (str[size - 1] == '\0')
3029 audit_size = size - 1;
3030 else
3031 audit_size = size;
3032 } else {
3033 str = "";
3034 audit_size = 0;
3035 }
3036 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
3037 audit_log_format(ab, "op=setxattr invalid_context=");
3038 audit_log_n_untrustedstring(ab, value, audit_size);
3039 audit_log_end(ab);
3040
3041 return rc;
3042 }
3043 rc = security_context_to_sid_force(value, size, &newsid);
3044 }
3045 if (rc)
3046 return rc;
3047
3048 rc = avc_has_perm(sid, newsid, isec->sclass,
3049 FILE__RELABELTO, &ad);
3050 if (rc)
3051 return rc;
3052
3053 rc = security_validate_transition(isec->sid, newsid, sid,
3054 isec->sclass);
3055 if (rc)
3056 return rc;
3057
3058 return avc_has_perm(newsid,
3059 sbsec->sid,
3060 SECCLASS_FILESYSTEM,
3061 FILESYSTEM__ASSOCIATE,
3062 &ad);
3063 }
3064
3065 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3066 const void *value, size_t size,
3067 int flags)
3068 {
3069 struct inode *inode = dentry->d_inode;
3070 struct inode_security_struct *isec = inode->i_security;
3071 u32 newsid;
3072 int rc;
3073
3074 if (strcmp(name, XATTR_NAME_SELINUX)) {
3075 /* Not an attribute we recognize, so nothing to do. */
3076 return;
3077 }
3078
3079 rc = security_context_to_sid_force(value, size, &newsid);
3080 if (rc) {
3081 printk(KERN_ERR "SELinux: unable to map context to SID"
3082 "for (%s, %lu), rc=%d\n",
3083 inode->i_sb->s_id, inode->i_ino, -rc);
3084 return;
3085 }
3086
3087 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3088 isec->sid = newsid;
3089 isec->initialized = 1;
3090
3091 return;
3092 }
3093
3094 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
3095 {
3096 const struct cred *cred = current_cred();
3097
3098 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3099 }
3100
3101 static int selinux_inode_listxattr(struct dentry *dentry)
3102 {
3103 const struct cred *cred = current_cred();
3104
3105 return dentry_has_perm(cred, dentry, FILE__GETATTR);
3106 }
3107
3108 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
3109 {
3110 if (strcmp(name, XATTR_NAME_SELINUX))
3111 return selinux_inode_setotherxattr(dentry, name);
3112
3113 /* No one is allowed to remove a SELinux security label.
3114 You can change the label, but all data must be labeled. */
3115 return -EACCES;
3116 }
3117
3118 /*
3119 * Copy the inode security context value to the user.
3120 *
3121 * Permission check is handled by selinux_inode_getxattr hook.
3122 */
3123 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
3124 {
3125 u32 size;
3126 int error;
3127 char *context = NULL;
3128 struct inode_security_struct *isec = inode->i_security;
3129
3130 if (strcmp(name, XATTR_SELINUX_SUFFIX))
3131 return -EOPNOTSUPP;
3132
3133 /*
3134 * If the caller has CAP_MAC_ADMIN, then get the raw context
3135 * value even if it is not defined by current policy; otherwise,
3136 * use the in-core value under current policy.
3137 * Use the non-auditing forms of the permission checks since
3138 * getxattr may be called by unprivileged processes commonly
3139 * and lack of permission just means that we fall back to the
3140 * in-core context value, not a denial.
3141 */
3142 error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
3143 SECURITY_CAP_NOAUDIT);
3144 if (!error)
3145 error = security_sid_to_context_force(isec->sid, &context,
3146 &size);
3147 else
3148 error = security_sid_to_context(isec->sid, &context, &size);
3149 if (error)
3150 return error;
3151 error = size;
3152 if (alloc) {
3153 *buffer = context;
3154 goto out_nofree;
3155 }
3156 kfree(context);
3157 out_nofree:
3158 return error;
3159 }
3160
3161 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3162 const void *value, size_t size, int flags)
3163 {
3164 struct inode_security_struct *isec = inode->i_security;
3165 u32 newsid;
3166 int rc;
3167
3168 if (strcmp(name, XATTR_SELINUX_SUFFIX))
3169 return -EOPNOTSUPP;
3170
3171 if (!value || !size)
3172 return -EACCES;
3173
3174 rc = security_context_to_sid((void *)value, size, &newsid, GFP_KERNEL);
3175 if (rc)
3176 return rc;
3177
3178 isec->sclass = inode_mode_to_security_class(inode->i_mode);
3179 isec->sid = newsid;
3180 isec->initialized = 1;
3181 return 0;
3182 }
3183
3184 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
3185 {
3186 const int len = sizeof(XATTR_NAME_SELINUX);
3187 if (buffer && len <= buffer_size)
3188 memcpy(buffer, XATTR_NAME_SELINUX, len);
3189 return len;
3190 }
3191
3192 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
3193 {
3194 struct inode_security_struct *isec = inode->i_security;
3195 *secid = isec->sid;
3196 }
3197
3198 /* file security operations */
3199
3200 static int selinux_revalidate_file_permission(struct file *file, int mask)
3201 {
3202 const struct cred *cred = current_cred();
3203 struct inode *inode = file_inode(file);
3204
3205 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
3206 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
3207 mask |= MAY_APPEND;
3208
3209 return file_has_perm(cred, file,
3210 file_mask_to_av(inode->i_mode, mask));
3211 }
3212
3213 static int selinux_file_permission(struct file *file, int mask)
3214 {
3215 struct inode *inode = file_inode(file);
3216 struct file_security_struct *fsec = file->f_security;
3217 struct inode_security_struct *isec = inode->i_security;
3218 u32 sid = current_sid();
3219
3220 if (!mask)
3221 /* No permission to check. Existence test. */
3222 return 0;
3223
3224 if (sid == fsec->sid && fsec->isid == isec->sid &&
3225 fsec->pseqno == avc_policy_seqno())
3226 /* No change since file_open check. */
3227 return 0;
3228
3229 return selinux_revalidate_file_permission(file, mask);
3230 }
3231
3232 static int selinux_file_alloc_security(struct file *file)
3233 {
3234 return file_alloc_security(file);
3235 }
3236
3237 static void selinux_file_free_security(struct file *file)
3238 {
3239 file_free_security(file);
3240 }
3241
3242 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3243 unsigned long arg)
3244 {
3245 const struct cred *cred = current_cred();
3246 int error = 0;
3247
3248 switch (cmd) {
3249 case FIONREAD:
3250 /* fall through */
3251 case FIBMAP:
3252 /* fall through */
3253 case FIGETBSZ:
3254 /* fall through */
3255 case FS_IOC_GETFLAGS:
3256 /* fall through */
3257 case FS_IOC_GETVERSION:
3258 error = file_has_perm(cred, file, FILE__GETATTR);
3259 break;
3260
3261 case FS_IOC_SETFLAGS:
3262 /* fall through */
3263 case FS_IOC_SETVERSION:
3264 error = file_has_perm(cred, file, FILE__SETATTR);
3265 break;
3266
3267 /* sys_ioctl() checks */
3268 case FIONBIO:
3269 /* fall through */
3270 case FIOASYNC:
3271 error = file_has_perm(cred, file, 0);
3272 break;
3273
3274 case KDSKBENT:
3275 case KDSKBSENT:
3276 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3277 SECURITY_CAP_AUDIT);
3278 break;
3279
3280 /* default case assumes that the command will go
3281 * to the file's ioctl() function.
3282 */
3283 default:
3284 error = file_has_perm(cred, file, FILE__IOCTL);
3285 }
3286 return error;
3287 }
3288
3289 static int default_noexec;
3290
3291 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3292 {
3293 const struct cred *cred = current_cred();
3294 int rc = 0;
3295
3296 if (default_noexec &&
3297 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
3298 /*
3299 * We are making executable an anonymous mapping or a
3300 * private file mapping that will also be writable.
3301 * This has an additional check.
3302 */
3303 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
3304 if (rc)
3305 goto error;
3306 }
3307
3308 if (file) {
3309 /* read access is always possible with a mapping */
3310 u32 av = FILE__READ;
3311
3312 /* write access only matters if the mapping is shared */
3313 if (shared && (prot & PROT_WRITE))
3314 av |= FILE__WRITE;
3315
3316 if (prot & PROT_EXEC)
3317 av |= FILE__EXECUTE;
3318
3319 return file_has_perm(cred, file, av);
3320 }
3321
3322 error:
3323 return rc;
3324 }
3325
3326 static int selinux_mmap_addr(unsigned long addr)
3327 {
3328 int rc;
3329
3330 /* do DAC check on address space usage */
3331 rc = cap_mmap_addr(addr);
3332 if (rc)
3333 return rc;
3334
3335 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3336 u32 sid = current_sid();
3337 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3338 MEMPROTECT__MMAP_ZERO, NULL);
3339 }
3340
3341 return rc;
3342 }
3343
3344 static int selinux_mmap_file(struct file *file, unsigned long reqprot,
3345 unsigned long prot, unsigned long flags)
3346 {
3347 if (selinux_checkreqprot)
3348 prot = reqprot;
3349
3350 return file_map_prot_check(file, prot,
3351 (flags & MAP_TYPE) == MAP_SHARED);
3352 }
3353
3354 static int selinux_file_mprotect(struct vm_area_struct *vma,
3355 unsigned long reqprot,
3356 unsigned long prot)
3357 {
3358 const struct cred *cred = current_cred();
3359
3360 if (selinux_checkreqprot)
3361 prot = reqprot;
3362
3363 if (default_noexec &&
3364 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3365 int rc = 0;
3366 if (vma->vm_start >= vma->vm_mm->start_brk &&
3367 vma->vm_end <= vma->vm_mm->brk) {
3368 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3369 } else if (!vma->vm_file &&
3370 vma->vm_start <= vma->vm_mm->start_stack &&
3371 vma->vm_end >= vma->vm_mm->start_stack) {
3372 rc = current_has_perm(current, PROCESS__EXECSTACK);
3373 } else if (vma->vm_file && vma->anon_vma) {
3374 /*
3375 * We are making executable a file mapping that has
3376 * had some COW done. Since pages might have been
3377 * written, check ability to execute the possibly
3378 * modified content. This typically should only
3379 * occur for text relocations.
3380 */
3381 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3382 }
3383 if (rc)
3384 return rc;
3385 }
3386
3387 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3388 }
3389
3390 static int selinux_file_lock(struct file *file, unsigned int cmd)
3391 {
3392 const struct cred *cred = current_cred();
3393
3394 return file_has_perm(cred, file, FILE__LOCK);
3395 }
3396
3397 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3398 unsigned long arg)
3399 {
3400 const struct cred *cred = current_cred();
3401 int err = 0;
3402
3403 switch (cmd) {
3404 case F_SETFL:
3405 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3406 err = file_has_perm(cred, file, FILE__WRITE);
3407 break;
3408 }
3409 /* fall through */
3410 case F_SETOWN:
3411 case F_SETSIG:
3412 case F_GETFL:
3413 case F_GETOWN:
3414 case F_GETSIG:
3415 case F_GETOWNER_UIDS:
3416 /* Just check FD__USE permission */
3417 err = file_has_perm(cred, file, 0);
3418 break;
3419 case F_GETLK:
3420 case F_SETLK:
3421 case F_SETLKW:
3422 case F_OFD_GETLK:
3423 case F_OFD_SETLK:
3424 case F_OFD_SETLKW:
3425 #if BITS_PER_LONG == 32
3426 case F_GETLK64:
3427 case F_SETLK64:
3428 case F_SETLKW64:
3429 #endif
3430 err = file_has_perm(cred, file, FILE__LOCK);
3431 break;
3432 }
3433
3434 return err;
3435 }
3436
3437 static void selinux_file_set_fowner(struct file *file)
3438 {
3439 struct file_security_struct *fsec;
3440
3441 fsec = file->f_security;
3442 fsec->fown_sid = current_sid();
3443 }
3444
3445 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3446 struct fown_struct *fown, int signum)
3447 {
3448 struct file *file;
3449 u32 sid = task_sid(tsk);
3450 u32 perm;
3451 struct file_security_struct *fsec;
3452
3453 /* struct fown_struct is never outside the context of a struct file */
3454 file = container_of(fown, struct file, f_owner);
3455
3456 fsec = file->f_security;
3457
3458 if (!signum)
3459 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3460 else
3461 perm = signal_to_av(signum);
3462
3463 return avc_has_perm(fsec->fown_sid, sid,
3464 SECCLASS_PROCESS, perm, NULL);
3465 }
3466
3467 static int selinux_file_receive(struct file *file)
3468 {
3469 const struct cred *cred = current_cred();
3470
3471 return file_has_perm(cred, file, file_to_av(file));
3472 }
3473
3474 static int selinux_file_open(struct file *file, const struct cred *cred)
3475 {
3476 struct file_security_struct *fsec;
3477 struct inode_security_struct *isec;
3478
3479 fsec = file->f_security;
3480 isec = file_inode(file)->i_security;
3481 /*
3482 * Save inode label and policy sequence number
3483 * at open-time so that selinux_file_permission
3484 * can determine whether revalidation is necessary.
3485 * Task label is already saved in the file security
3486 * struct as its SID.
3487 */
3488 fsec->isid = isec->sid;
3489 fsec->pseqno = avc_policy_seqno();
3490 /*
3491 * Since the inode label or policy seqno may have changed
3492 * between the selinux_inode_permission check and the saving
3493 * of state above, recheck that access is still permitted.
3494 * Otherwise, access might never be revalidated against the
3495 * new inode label or new policy.
3496 * This check is not redundant - do not remove.
3497 */
3498 return file_path_has_perm(cred, file, open_file_to_av(file));
3499 }
3500
3501 /* task security operations */
3502
3503 static int selinux_task_create(unsigned long clone_flags)
3504 {
3505 return current_has_perm(current, PROCESS__FORK);
3506 }
3507
3508 /*
3509 * allocate the SELinux part of blank credentials
3510 */
3511 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3512 {
3513 struct task_security_struct *tsec;
3514
3515 tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3516 if (!tsec)
3517 return -ENOMEM;
3518
3519 cred->security = tsec;
3520 return 0;
3521 }
3522
3523 /*
3524 * detach and free the LSM part of a set of credentials
3525 */
3526 static void selinux_cred_free(struct cred *cred)
3527 {
3528 struct task_security_struct *tsec = cred->security;
3529
3530 /*
3531 * cred->security == NULL if security_cred_alloc_blank() or
3532 * security_prepare_creds() returned an error.
3533 */
3534 BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE);
3535 cred->security = (void *) 0x7UL;
3536 kfree(tsec);
3537 }
3538
3539 /*
3540 * prepare a new set of credentials for modification
3541 */
3542 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3543 gfp_t gfp)
3544 {
3545 const struct task_security_struct *old_tsec;
3546 struct task_security_struct *tsec;
3547
3548 old_tsec = old->security;
3549
3550 tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3551 if (!tsec)
3552 return -ENOMEM;
3553
3554 new->security = tsec;
3555 return 0;
3556 }
3557
3558 /*
3559 * transfer the SELinux data to a blank set of creds
3560 */
3561 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3562 {
3563 const struct task_security_struct *old_tsec = old->security;
3564 struct task_security_struct *tsec = new->security;
3565
3566 *tsec = *old_tsec;
3567 }
3568
3569 /*
3570 * set the security data for a kernel service
3571 * - all the creation contexts are set to unlabelled
3572 */
3573 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3574 {
3575 struct task_security_struct *tsec = new->security;
3576 u32 sid = current_sid();
3577 int ret;
3578
3579 ret = avc_has_perm(sid, secid,
3580 SECCLASS_KERNEL_SERVICE,
3581 KERNEL_SERVICE__USE_AS_OVERRIDE,
3582 NULL);
3583 if (ret == 0) {
3584 tsec->sid = secid;
3585 tsec->create_sid = 0;
3586 tsec->keycreate_sid = 0;
3587 tsec->sockcreate_sid = 0;
3588 }
3589 return ret;
3590 }
3591
3592 /*
3593 * set the file creation context in a security record to the same as the
3594 * objective context of the specified inode
3595 */
3596 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3597 {
3598 struct inode_security_struct *isec = inode->i_security;
3599 struct task_security_struct *tsec = new->security;
3600 u32 sid = current_sid();
3601 int ret;
3602
3603 ret = avc_has_perm(sid, isec->sid,
3604 SECCLASS_KERNEL_SERVICE,
3605 KERNEL_SERVICE__CREATE_FILES_AS,
3606 NULL);
3607
3608 if (ret == 0)
3609 tsec->create_sid = isec->sid;
3610 return ret;
3611 }
3612
3613 static int selinux_kernel_module_request(char *kmod_name)
3614 {
3615 u32 sid;
3616 struct common_audit_data ad;
3617
3618 sid = task_sid(current);
3619
3620 ad.type = LSM_AUDIT_DATA_KMOD;
3621 ad.u.kmod_name = kmod_name;
3622
3623 return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
3624 SYSTEM__MODULE_REQUEST, &ad);
3625 }
3626
3627 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3628 {
3629 return current_has_perm(p, PROCESS__SETPGID);
3630 }
3631
3632 static int selinux_task_getpgid(struct task_struct *p)
3633 {
3634 return current_has_perm(p, PROCESS__GETPGID);
3635 }
3636
3637 static int selinux_task_getsid(struct task_struct *p)
3638 {
3639 return current_has_perm(p, PROCESS__GETSESSION);
3640 }
3641
3642 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3643 {
3644 *secid = task_sid(p);
3645 }
3646
3647 static int selinux_task_setnice(struct task_struct *p, int nice)
3648 {
3649 int rc;
3650
3651 rc = cap_task_setnice(p, nice);
3652 if (rc)
3653 return rc;
3654
3655 return current_has_perm(p, PROCESS__SETSCHED);
3656 }
3657
3658 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3659 {
3660 int rc;
3661
3662 rc = cap_task_setioprio(p, ioprio);
3663 if (rc)
3664 return rc;
3665
3666 return current_has_perm(p, PROCESS__SETSCHED);
3667 }
3668
3669 static int selinux_task_getioprio(struct task_struct *p)
3670 {
3671 return current_has_perm(p, PROCESS__GETSCHED);
3672 }
3673
3674 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
3675 struct rlimit *new_rlim)
3676 {
3677 struct rlimit *old_rlim = p->signal->rlim + resource;
3678
3679 /* Control the ability to change the hard limit (whether
3680 lowering or raising it), so that the hard limit can
3681 later be used as a safe reset point for the soft limit
3682 upon context transitions. See selinux_bprm_committing_creds. */
3683 if (old_rlim->rlim_max != new_rlim->rlim_max)
3684 return current_has_perm(p, PROCESS__SETRLIMIT);
3685
3686 return 0;
3687 }
3688
3689 static int selinux_task_setscheduler(struct task_struct *p)
3690 {
3691 int rc;
3692
3693 rc = cap_task_setscheduler(p);
3694 if (rc)
3695 return rc;
3696
3697 return current_has_perm(p, PROCESS__SETSCHED);
3698 }
3699
3700 static int selinux_task_getscheduler(struct task_struct *p)
3701 {
3702 return current_has_perm(p, PROCESS__GETSCHED);
3703 }
3704
3705 static int selinux_task_movememory(struct task_struct *p)
3706 {
3707 return current_has_perm(p, PROCESS__SETSCHED);
3708 }
3709
3710 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3711 int sig, u32 secid)
3712 {
3713 u32 perm;
3714 int rc;
3715
3716 if (!sig)
3717 perm = PROCESS__SIGNULL; /* null signal; existence test */
3718 else
3719 perm = signal_to_av(sig);
3720 if (secid)
3721 rc = avc_has_perm(secid, task_sid(p),
3722 SECCLASS_PROCESS, perm, NULL);
3723 else
3724 rc = current_has_perm(p, perm);
3725 return rc;
3726 }
3727
3728 static int selinux_task_wait(struct task_struct *p)
3729 {
3730 return task_has_perm(p, current, PROCESS__SIGCHLD);
3731 }
3732
3733 static void selinux_task_to_inode(struct task_struct *p,
3734 struct inode *inode)
3735 {
3736 struct inode_security_struct *isec = inode->i_security;
3737 u32 sid = task_sid(p);
3738
3739 isec->sid = sid;
3740 isec->initialized = 1;
3741 }
3742
3743 /* Returns error only if unable to parse addresses */
3744 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3745 struct common_audit_data *ad, u8 *proto)
3746 {
3747 int offset, ihlen, ret = -EINVAL;
3748 struct iphdr _iph, *ih;
3749
3750 offset = skb_network_offset(skb);
3751 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3752 if (ih == NULL)
3753 goto out;
3754
3755 ihlen = ih->ihl * 4;
3756 if (ihlen < sizeof(_iph))
3757 goto out;
3758
3759 ad->u.net->v4info.saddr = ih->saddr;
3760 ad->u.net->v4info.daddr = ih->daddr;
3761 ret = 0;
3762
3763 if (proto)
3764 *proto = ih->protocol;
3765
3766 switch (ih->protocol) {
3767 case IPPROTO_TCP: {
3768 struct tcphdr _tcph, *th;
3769
3770 if (ntohs(ih->frag_off) & IP_OFFSET)
3771 break;
3772
3773 offset += ihlen;
3774 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3775 if (th == NULL)
3776 break;
3777
3778 ad->u.net->sport = th->source;
3779 ad->u.net->dport = th->dest;
3780 break;
3781 }
3782
3783 case IPPROTO_UDP: {
3784 struct udphdr _udph, *uh;
3785
3786 if (ntohs(ih->frag_off) & IP_OFFSET)
3787 break;
3788
3789 offset += ihlen;
3790 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3791 if (uh == NULL)
3792 break;
3793
3794 ad->u.net->sport = uh->source;
3795 ad->u.net->dport = uh->dest;
3796 break;
3797 }
3798
3799 case IPPROTO_DCCP: {
3800 struct dccp_hdr _dccph, *dh;
3801
3802 if (ntohs(ih->frag_off) & IP_OFFSET)
3803 break;
3804
3805 offset += ihlen;
3806 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3807 if (dh == NULL)
3808 break;
3809
3810 ad->u.net->sport = dh->dccph_sport;
3811 ad->u.net->dport = dh->dccph_dport;
3812 break;
3813 }
3814
3815 default:
3816 break;
3817 }
3818 out:
3819 return ret;
3820 }
3821
3822 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3823
3824 /* Returns error only if unable to parse addresses */
3825 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3826 struct common_audit_data *ad, u8 *proto)
3827 {
3828 u8 nexthdr;
3829 int ret = -EINVAL, offset;
3830 struct ipv6hdr _ipv6h, *ip6;
3831 __be16 frag_off;
3832
3833 offset = skb_network_offset(skb);
3834 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3835 if (ip6 == NULL)
3836 goto out;
3837
3838 ad->u.net->v6info.saddr = ip6->saddr;
3839 ad->u.net->v6info.daddr = ip6->daddr;
3840 ret = 0;
3841
3842 nexthdr = ip6->nexthdr;
3843 offset += sizeof(_ipv6h);
3844 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
3845 if (offset < 0)
3846 goto out;
3847
3848 if (proto)
3849 *proto = nexthdr;
3850
3851 switch (nexthdr) {
3852 case IPPROTO_TCP: {
3853 struct tcphdr _tcph, *th;
3854
3855 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3856 if (th == NULL)
3857 break;
3858
3859 ad->u.net->sport = th->source;
3860 ad->u.net->dport = th->dest;
3861 break;
3862 }
3863
3864 case IPPROTO_UDP: {
3865 struct udphdr _udph, *uh;
3866
3867 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3868 if (uh == NULL)
3869 break;
3870
3871 ad->u.net->sport = uh->source;
3872 ad->u.net->dport = uh->dest;
3873 break;
3874 }
3875
3876 case IPPROTO_DCCP: {
3877 struct dccp_hdr _dccph, *dh;
3878
3879 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3880 if (dh == NULL)
3881 break;
3882
3883 ad->u.net->sport = dh->dccph_sport;
3884 ad->u.net->dport = dh->dccph_dport;
3885 break;
3886 }
3887
3888 /* includes fragments */
3889 default:
3890 break;
3891 }
3892 out:
3893 return ret;
3894 }
3895
3896 #endif /* IPV6 */
3897
3898 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3899 char **_addrp, int src, u8 *proto)
3900 {
3901 char *addrp;
3902 int ret;
3903
3904 switch (ad->u.net->family) {
3905 case PF_INET:
3906 ret = selinux_parse_skb_ipv4(skb, ad, proto);
3907 if (ret)
3908 goto parse_error;
3909 addrp = (char *)(src ? &ad->u.net->v4info.saddr :
3910 &ad->u.net->v4info.daddr);
3911 goto okay;
3912
3913 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3914 case PF_INET6:
3915 ret = selinux_parse_skb_ipv6(skb, ad, proto);
3916 if (ret)
3917 goto parse_error;
3918 addrp = (char *)(src ? &ad->u.net->v6info.saddr :
3919 &ad->u.net->v6info.daddr);
3920 goto okay;
3921 #endif /* IPV6 */
3922 default:
3923 addrp = NULL;
3924 goto okay;
3925 }
3926
3927 parse_error:
3928 printk(KERN_WARNING
3929 "SELinux: failure in selinux_parse_skb(),"
3930 " unable to parse packet\n");
3931 return ret;
3932
3933 okay:
3934 if (_addrp)
3935 *_addrp = addrp;
3936 return 0;
3937 }
3938
3939 /**
3940 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3941 * @skb: the packet
3942 * @family: protocol family
3943 * @sid: the packet's peer label SID
3944 *
3945 * Description:
3946 * Check the various different forms of network peer labeling and determine
3947 * the peer label/SID for the packet; most of the magic actually occurs in
3948 * the security server function security_net_peersid_cmp(). The function
3949 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
3950 * or -EACCES if @sid is invalid due to inconsistencies with the different
3951 * peer labels.
3952 *
3953 */
3954 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3955 {
3956 int err;
3957 u32 xfrm_sid;
3958 u32 nlbl_sid;
3959 u32 nlbl_type;
3960
3961 err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
3962 if (unlikely(err))
3963 return -EACCES;
3964 err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3965 if (unlikely(err))
3966 return -EACCES;
3967
3968 err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
3969 if (unlikely(err)) {
3970 printk(KERN_WARNING
3971 "SELinux: failure in selinux_skb_peerlbl_sid(),"
3972 " unable to determine packet's peer label\n");
3973 return -EACCES;
3974 }
3975
3976 return 0;
3977 }
3978
3979 /**
3980 * selinux_conn_sid - Determine the child socket label for a connection
3981 * @sk_sid: the parent socket's SID
3982 * @skb_sid: the packet's SID
3983 * @conn_sid: the resulting connection SID
3984 *
3985 * If @skb_sid is valid then the user:role:type information from @sk_sid is
3986 * combined with the MLS information from @skb_sid in order to create
3987 * @conn_sid. If @skb_sid is not valid then then @conn_sid is simply a copy
3988 * of @sk_sid. Returns zero on success, negative values on failure.
3989 *
3990 */
3991 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
3992 {
3993 int err = 0;
3994
3995 if (skb_sid != SECSID_NULL)
3996 err = security_sid_mls_copy(sk_sid, skb_sid, conn_sid);
3997 else
3998 *conn_sid = sk_sid;
3999
4000 return err;
4001 }
4002
4003 /* socket security operations */
4004
4005 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
4006 u16 secclass, u32 *socksid)
4007 {
4008 if (tsec->sockcreate_sid > SECSID_NULL) {
4009 *socksid = tsec->sockcreate_sid;
4010 return 0;
4011 }
4012
4013 return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
4014 socksid);
4015 }
4016
4017 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
4018 {
4019 struct sk_security_struct *sksec = sk->sk_security;
4020 struct common_audit_data ad;
4021 struct lsm_network_audit net = {0,};
4022 u32 tsid = task_sid(task);
4023
4024 if (sksec->sid == SECINITSID_KERNEL)
4025 return 0;
4026
4027 ad.type = LSM_AUDIT_DATA_NET;
4028 ad.u.net = &net;
4029 ad.u.net->sk = sk;
4030
4031 return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
4032 }
4033
4034 static int selinux_socket_create(int family, int type,
4035 int protocol, int kern)
4036 {
4037 const struct task_security_struct *tsec = current_security();
4038 u32 newsid;
4039 u16 secclass;
4040 int rc;
4041
4042 if (kern)
4043 return 0;
4044
4045 secclass = socket_type_to_security_class(family, type, protocol);
4046 rc = socket_sockcreate_sid(tsec, secclass, &newsid);
4047 if (rc)
4048 return rc;
4049
4050 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
4051 }
4052
4053 static int selinux_socket_post_create(struct socket *sock, int family,
4054 int type, int protocol, int kern)
4055 {
4056 const struct task_security_struct *tsec = current_security();
4057 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
4058 struct sk_security_struct *sksec;
4059 int err = 0;
4060
4061 isec->sclass = socket_type_to_security_class(family, type, protocol);
4062
4063 if (kern)
4064 isec->sid = SECINITSID_KERNEL;
4065 else {
4066 err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
4067 if (err)
4068 return err;
4069 }
4070
4071 isec->initialized = 1;
4072
4073 if (sock->sk) {
4074 sksec = sock->sk->sk_security;
4075 sksec->sid = isec->sid;
4076 sksec->sclass = isec->sclass;
4077 err = selinux_netlbl_socket_post_create(sock->sk, family);
4078 }
4079
4080 return err;
4081 }
4082
4083 /* Range of port numbers used to automatically bind.
4084 Need to determine whether we should perform a name_bind
4085 permission check between the socket and the port number. */
4086
4087 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
4088 {
4089 struct sock *sk = sock->sk;
4090 u16 family;
4091 int err;
4092
4093 err = sock_has_perm(current, sk, SOCKET__BIND);
4094 if (err)
4095 goto out;
4096
4097 /*
4098 * If PF_INET or PF_INET6, check name_bind permission for the port.
4099 * Multiple address binding for SCTP is not supported yet: we just
4100 * check the first address now.
4101 */
4102 family = sk->sk_family;
4103 if (family == PF_INET || family == PF_INET6) {
4104 char *addrp;
4105 struct sk_security_struct *sksec = sk->sk_security;
4106 struct common_audit_data ad;
4107 struct lsm_network_audit net = {0,};
4108 struct sockaddr_in *addr4 = NULL;
4109 struct sockaddr_in6 *addr6 = NULL;
4110 unsigned short snum;
4111 u32 sid, node_perm;
4112
4113 if (family == PF_INET) {
4114 addr4 = (struct sockaddr_in *)address;
4115 snum = ntohs(addr4->sin_port);
4116 addrp = (char *)&addr4->sin_addr.s_addr;
4117 } else {
4118 addr6 = (struct sockaddr_in6 *)address;
4119 snum = ntohs(addr6->sin6_port);
4120 addrp = (char *)&addr6->sin6_addr.s6_addr;
4121 }
4122
4123 if (snum) {
4124 int low, high;
4125
4126 inet_get_local_port_range(sock_net(sk), &low, &high);
4127
4128 if (snum < max(PROT_SOCK, low) || snum > high) {
4129 err = sel_netport_sid(sk->sk_protocol,
4130 snum, &sid);
4131 if (err)
4132 goto out;
4133 ad.type = LSM_AUDIT_DATA_NET;
4134 ad.u.net = &net;
4135 ad.u.net->sport = htons(snum);
4136 ad.u.net->family = family;
4137 err = avc_has_perm(sksec->sid, sid,
4138 sksec->sclass,
4139 SOCKET__NAME_BIND, &ad);
4140 if (err)
4141 goto out;
4142 }
4143 }
4144
4145 switch (sksec->sclass) {
4146 case SECCLASS_TCP_SOCKET:
4147 node_perm = TCP_SOCKET__NODE_BIND;
4148 break;
4149
4150 case SECCLASS_UDP_SOCKET:
4151 node_perm = UDP_SOCKET__NODE_BIND;
4152 break;
4153
4154 case SECCLASS_DCCP_SOCKET:
4155 node_perm = DCCP_SOCKET__NODE_BIND;
4156 break;
4157
4158 default:
4159 node_perm = RAWIP_SOCKET__NODE_BIND;
4160 break;
4161 }
4162
4163 err = sel_netnode_sid(addrp, family, &sid);
4164 if (err)
4165 goto out;
4166
4167 ad.type = LSM_AUDIT_DATA_NET;
4168 ad.u.net = &net;
4169 ad.u.net->sport = htons(snum);
4170 ad.u.net->family = family;
4171
4172 if (family == PF_INET)
4173 ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
4174 else
4175 ad.u.net->v6info.saddr = addr6->sin6_addr;
4176
4177 err = avc_has_perm(sksec->sid, sid,
4178 sksec->sclass, node_perm, &ad);
4179 if (err)
4180 goto out;
4181 }
4182 out:
4183 return err;
4184 }
4185
4186 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
4187 {
4188 struct sock *sk = sock->sk;
4189 struct sk_security_struct *sksec = sk->sk_security;
4190 int err;
4191
4192 err = sock_has_perm(current, sk, SOCKET__CONNECT);
4193 if (err)
4194 return err;
4195
4196 /*
4197 * If a TCP or DCCP socket, check name_connect permission for the port.
4198 */
4199 if (sksec->sclass == SECCLASS_TCP_SOCKET ||
4200 sksec->sclass == SECCLASS_DCCP_SOCKET) {
4201 struct common_audit_data ad;
4202 struct lsm_network_audit net = {0,};
4203 struct sockaddr_in *addr4 = NULL;
4204 struct sockaddr_in6 *addr6 = NULL;
4205 unsigned short snum;
4206 u32 sid, perm;
4207
4208 if (sk->sk_family == PF_INET) {
4209 addr4 = (struct sockaddr_in *)address;
4210 if (addrlen < sizeof(struct sockaddr_in))
4211 return -EINVAL;
4212 snum = ntohs(addr4->sin_port);
4213 } else {
4214 addr6 = (struct sockaddr_in6 *)address;
4215 if (addrlen < SIN6_LEN_RFC2133)
4216 return -EINVAL;
4217 snum = ntohs(addr6->sin6_port);
4218 }
4219
4220 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
4221 if (err)
4222 goto out;
4223
4224 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
4225 TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
4226
4227 ad.type = LSM_AUDIT_DATA_NET;
4228 ad.u.net = &net;
4229 ad.u.net->dport = htons(snum);
4230 ad.u.net->family = sk->sk_family;
4231 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
4232 if (err)
4233 goto out;
4234 }
4235
4236 err = selinux_netlbl_socket_connect(sk, address);
4237
4238 out:
4239 return err;
4240 }
4241
4242 static int selinux_socket_listen(struct socket *sock, int backlog)
4243 {
4244 return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
4245 }
4246
4247 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
4248 {
4249 int err;
4250 struct inode_security_struct *isec;
4251 struct inode_security_struct *newisec;
4252
4253 err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
4254 if (err)
4255 return err;
4256
4257 newisec = SOCK_INODE(newsock)->i_security;
4258
4259 isec = SOCK_INODE(sock)->i_security;
4260 newisec->sclass = isec->sclass;
4261 newisec->sid = isec->sid;
4262 newisec->initialized = 1;
4263
4264 return 0;
4265 }
4266
4267 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4268 int size)
4269 {
4270 return sock_has_perm(current, sock->sk, SOCKET__WRITE);
4271 }
4272
4273 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4274 int size, int flags)
4275 {
4276 return sock_has_perm(current, sock->sk, SOCKET__READ);
4277 }
4278
4279 static int selinux_socket_getsockname(struct socket *sock)
4280 {
4281 return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4282 }
4283
4284 static int selinux_socket_getpeername(struct socket *sock)
4285 {
4286 return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4287 }
4288
4289 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4290 {
4291 int err;
4292
4293 err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
4294 if (err)
4295 return err;
4296
4297 return selinux_netlbl_socket_setsockopt(sock, level, optname);
4298 }
4299
4300 static int selinux_socket_getsockopt(struct socket *sock, int level,
4301 int optname)
4302 {
4303 return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
4304 }
4305
4306 static int selinux_socket_shutdown(struct socket *sock, int how)
4307 {
4308 return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
4309 }
4310
4311 static int selinux_socket_unix_stream_connect(struct sock *sock,
4312 struct sock *other,
4313 struct sock *newsk)
4314 {
4315 struct sk_security_struct *sksec_sock = sock->sk_security;
4316 struct sk_security_struct *sksec_other = other->sk_security;
4317 struct sk_security_struct *sksec_new = newsk->sk_security;
4318 struct common_audit_data ad;
4319 struct lsm_network_audit net = {0,};
4320 int err;
4321
4322 ad.type = LSM_AUDIT_DATA_NET;
4323 ad.u.net = &net;
4324 ad.u.net->sk = other;
4325
4326 err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
4327 sksec_other->sclass,
4328 UNIX_STREAM_SOCKET__CONNECTTO, &ad);
4329 if (err)
4330 return err;
4331
4332 /* server child socket */
4333 sksec_new->peer_sid = sksec_sock->sid;
4334 err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
4335 &sksec_new->sid);
4336 if (err)
4337 return err;
4338
4339 /* connecting socket */
4340 sksec_sock->peer_sid = sksec_new->sid;
4341
4342 return 0;
4343 }
4344
4345 static int selinux_socket_unix_may_send(struct socket *sock,
4346 struct socket *other)
4347 {
4348 struct sk_security_struct *ssec = sock->sk->sk_security;
4349 struct sk_security_struct *osec = other->sk->sk_security;
4350 struct common_audit_data ad;
4351 struct lsm_network_audit net = {0,};
4352
4353 ad.type = LSM_AUDIT_DATA_NET;
4354 ad.u.net = &net;
4355 ad.u.net->sk = other->sk;
4356
4357 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
4358 &ad);
4359 }
4360
4361 static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
4362 char *addrp, u16 family, u32 peer_sid,
4363 struct common_audit_data *ad)
4364 {
4365 int err;
4366 u32 if_sid;
4367 u32 node_sid;
4368
4369 err = sel_netif_sid(ns, ifindex, &if_sid);
4370 if (err)
4371 return err;
4372 err = avc_has_perm(peer_sid, if_sid,
4373 SECCLASS_NETIF, NETIF__INGRESS, ad);
4374 if (err)
4375 return err;
4376
4377 err = sel_netnode_sid(addrp, family, &node_sid);
4378 if (err)
4379 return err;
4380 return avc_has_perm(peer_sid, node_sid,
4381 SECCLASS_NODE, NODE__RECVFROM, ad);
4382 }
4383
4384 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4385 u16 family)
4386 {
4387 int err = 0;
4388 struct sk_security_struct *sksec = sk->sk_security;
4389 u32 sk_sid = sksec->sid;
4390 struct common_audit_data ad;
4391 struct lsm_network_audit net = {0,};
4392 char *addrp;
4393
4394 ad.type = LSM_AUDIT_DATA_NET;
4395 ad.u.net = &net;
4396 ad.u.net->netif = skb->skb_iif;
4397 ad.u.net->family = family;
4398 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4399 if (err)
4400 return err;
4401
4402 if (selinux_secmark_enabled()) {
4403 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4404 PACKET__RECV, &ad);
4405 if (err)
4406 return err;
4407 }
4408
4409 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4410 if (err)
4411 return err;
4412 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4413
4414 return err;
4415 }
4416
4417 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4418 {
4419 int err;
4420 struct sk_security_struct *sksec = sk->sk_security;
4421 u16 family = sk->sk_family;
4422 u32 sk_sid = sksec->sid;
4423 struct common_audit_data ad;
4424 struct lsm_network_audit net = {0,};
4425 char *addrp;
4426 u8 secmark_active;
4427 u8 peerlbl_active;
4428
4429 if (family != PF_INET && family != PF_INET6)
4430 return 0;
4431
4432 /* Handle mapped IPv4 packets arriving via IPv6 sockets */
4433 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4434 family = PF_INET;
4435
4436 /* If any sort of compatibility mode is enabled then handoff processing
4437 * to the selinux_sock_rcv_skb_compat() function to deal with the
4438 * special handling. We do this in an attempt to keep this function
4439 * as fast and as clean as possible. */
4440 if (!selinux_policycap_netpeer)
4441 return selinux_sock_rcv_skb_compat(sk, skb, family);
4442
4443 secmark_active = selinux_secmark_enabled();
4444 peerlbl_active = selinux_peerlbl_enabled();
4445 if (!secmark_active && !peerlbl_active)
4446 return 0;
4447
4448 ad.type = LSM_AUDIT_DATA_NET;
4449 ad.u.net = &net;
4450 ad.u.net->netif = skb->skb_iif;
4451 ad.u.net->family = family;
4452 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4453 if (err)
4454 return err;
4455
4456 if (peerlbl_active) {
4457 u32 peer_sid;
4458
4459 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4460 if (err)
4461 return err;
4462 err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
4463 addrp, family, peer_sid, &ad);
4464 if (err) {
4465 selinux_netlbl_err(skb, err, 0);
4466 return err;
4467 }
4468 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4469 PEER__RECV, &ad);
4470 if (err) {
4471 selinux_netlbl_err(skb, err, 0);
4472 return err;
4473 }
4474 }
4475
4476 if (secmark_active) {
4477 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4478 PACKET__RECV, &ad);
4479 if (err)
4480 return err;
4481 }
4482
4483 return err;
4484 }
4485
4486 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4487 int __user *optlen, unsigned len)
4488 {
4489 int err = 0;
4490 char *scontext;
4491 u32 scontext_len;
4492 struct sk_security_struct *sksec = sock->sk->sk_security;
4493 u32 peer_sid = SECSID_NULL;
4494
4495 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4496 sksec->sclass == SECCLASS_TCP_SOCKET)
4497 peer_sid = sksec->peer_sid;
4498 if (peer_sid == SECSID_NULL)
4499 return -ENOPROTOOPT;
4500
4501 err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4502 if (err)
4503 return err;
4504
4505 if (scontext_len > len) {
4506 err = -ERANGE;
4507 goto out_len;
4508 }
4509
4510 if (copy_to_user(optval, scontext, scontext_len))
4511 err = -EFAULT;
4512
4513 out_len:
4514 if (put_user(scontext_len, optlen))
4515 err = -EFAULT;
4516 kfree(scontext);
4517 return err;
4518 }
4519
4520 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4521 {
4522 u32 peer_secid = SECSID_NULL;
4523 u16 family;
4524
4525 if (skb && skb->protocol == htons(ETH_P_IP))
4526 family = PF_INET;
4527 else if (skb && skb->protocol == htons(ETH_P_IPV6))
4528 family = PF_INET6;
4529 else if (sock)
4530 family = sock->sk->sk_family;
4531 else
4532 goto out;
4533
4534 if (sock && family == PF_UNIX)
4535 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4536 else if (skb)
4537 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4538
4539 out:
4540 *secid = peer_secid;
4541 if (peer_secid == SECSID_NULL)
4542 return -EINVAL;
4543 return 0;
4544 }
4545
4546 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4547 {
4548 struct sk_security_struct *sksec;
4549
4550 sksec = kzalloc(sizeof(*sksec), priority);
4551 if (!sksec)
4552 return -ENOMEM;
4553
4554 sksec->peer_sid = SECINITSID_UNLABELED;
4555 sksec->sid = SECINITSID_UNLABELED;
4556 selinux_netlbl_sk_security_reset(sksec);
4557 sk->sk_security = sksec;
4558
4559 return 0;
4560 }
4561
4562 static void selinux_sk_free_security(struct sock *sk)
4563 {
4564 struct sk_security_struct *sksec = sk->sk_security;
4565
4566 sk->sk_security = NULL;
4567 selinux_netlbl_sk_security_free(sksec);
4568 kfree(sksec);
4569 }
4570
4571 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4572 {
4573 struct sk_security_struct *sksec = sk->sk_security;
4574 struct sk_security_struct *newsksec = newsk->sk_security;
4575
4576 newsksec->sid = sksec->sid;
4577 newsksec->peer_sid = sksec->peer_sid;
4578 newsksec->sclass = sksec->sclass;
4579
4580 selinux_netlbl_sk_security_reset(newsksec);
4581 }
4582
4583 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4584 {
4585 if (!sk)
4586 *secid = SECINITSID_ANY_SOCKET;
4587 else {
4588 struct sk_security_struct *sksec = sk->sk_security;
4589
4590 *secid = sksec->sid;
4591 }
4592 }
4593
4594 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4595 {
4596 struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
4597 struct sk_security_struct *sksec = sk->sk_security;
4598
4599 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4600 sk->sk_family == PF_UNIX)
4601 isec->sid = sksec->sid;
4602 sksec->sclass = isec->sclass;
4603 }
4604
4605 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4606 struct request_sock *req)
4607 {
4608 struct sk_security_struct *sksec = sk->sk_security;
4609 int err;
4610 u16 family = req->rsk_ops->family;
4611 u32 connsid;
4612 u32 peersid;
4613
4614 err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4615 if (err)
4616 return err;
4617 err = selinux_conn_sid(sksec->sid, peersid, &connsid);
4618 if (err)
4619 return err;
4620 req->secid = connsid;
4621 req->peer_secid = peersid;
4622
4623 return selinux_netlbl_inet_conn_request(req, family);
4624 }
4625
4626 static void selinux_inet_csk_clone(struct sock *newsk,
4627 const struct request_sock *req)
4628 {
4629 struct sk_security_struct *newsksec = newsk->sk_security;
4630
4631 newsksec->sid = req->secid;
4632 newsksec->peer_sid = req->peer_secid;
4633 /* NOTE: Ideally, we should also get the isec->sid for the
4634 new socket in sync, but we don't have the isec available yet.
4635 So we will wait until sock_graft to do it, by which
4636 time it will have been created and available. */
4637
4638 /* We don't need to take any sort of lock here as we are the only
4639 * thread with access to newsksec */
4640 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4641 }
4642
4643 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4644 {
4645 u16 family = sk->sk_family;
4646 struct sk_security_struct *sksec = sk->sk_security;
4647
4648 /* handle mapped IPv4 packets arriving via IPv6 sockets */
4649 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4650 family = PF_INET;
4651
4652 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4653 }
4654
4655 static void selinux_skb_owned_by(struct sk_buff *skb, struct sock *sk)
4656 {
4657 skb_set_owner_w(skb, sk);
4658 }
4659
4660 static int selinux_secmark_relabel_packet(u32 sid)
4661 {
4662 const struct task_security_struct *__tsec;
4663 u32 tsid;
4664
4665 __tsec = current_security();
4666 tsid = __tsec->sid;
4667
4668 return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
4669 }
4670
4671 static void selinux_secmark_refcount_inc(void)
4672 {
4673 atomic_inc(&selinux_secmark_refcount);
4674 }
4675
4676 static void selinux_secmark_refcount_dec(void)
4677 {
4678 atomic_dec(&selinux_secmark_refcount);
4679 }
4680
4681 static void selinux_req_classify_flow(const struct request_sock *req,
4682 struct flowi *fl)
4683 {
4684 fl->flowi_secid = req->secid;
4685 }
4686
4687 static int selinux_tun_dev_alloc_security(void **security)
4688 {
4689 struct tun_security_struct *tunsec;
4690
4691 tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL);
4692 if (!tunsec)
4693 return -ENOMEM;
4694 tunsec->sid = current_sid();
4695
4696 *security = tunsec;
4697 return 0;
4698 }
4699
4700 static void selinux_tun_dev_free_security(void *security)
4701 {
4702 kfree(security);
4703 }
4704
4705 static int selinux_tun_dev_create(void)
4706 {
4707 u32 sid = current_sid();
4708
4709 /* we aren't taking into account the "sockcreate" SID since the socket
4710 * that is being created here is not a socket in the traditional sense,
4711 * instead it is a private sock, accessible only to the kernel, and
4712 * representing a wide range of network traffic spanning multiple
4713 * connections unlike traditional sockets - check the TUN driver to
4714 * get a better understanding of why this socket is special */
4715
4716 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4717 NULL);
4718 }
4719
4720 static int selinux_tun_dev_attach_queue(void *security)
4721 {
4722 struct tun_security_struct *tunsec = security;
4723
4724 return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
4725 TUN_SOCKET__ATTACH_QUEUE, NULL);
4726 }
4727
4728 static int selinux_tun_dev_attach(struct sock *sk, void *security)
4729 {
4730 struct tun_security_struct *tunsec = security;
4731 struct sk_security_struct *sksec = sk->sk_security;
4732
4733 /* we don't currently perform any NetLabel based labeling here and it
4734 * isn't clear that we would want to do so anyway; while we could apply
4735 * labeling without the support of the TUN user the resulting labeled
4736 * traffic from the other end of the connection would almost certainly
4737 * cause confusion to the TUN user that had no idea network labeling
4738 * protocols were being used */
4739
4740 sksec->sid = tunsec->sid;
4741 sksec->sclass = SECCLASS_TUN_SOCKET;
4742
4743 return 0;
4744 }
4745
4746 static int selinux_tun_dev_open(void *security)
4747 {
4748 struct tun_security_struct *tunsec = security;
4749 u32 sid = current_sid();
4750 int err;
4751
4752 err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
4753 TUN_SOCKET__RELABELFROM, NULL);
4754 if (err)
4755 return err;
4756 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4757 TUN_SOCKET__RELABELTO, NULL);
4758 if (err)
4759 return err;
4760 tunsec->sid = sid;
4761
4762 return 0;
4763 }
4764
4765 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4766 {
4767 int err = 0;
4768 u32 perm;
4769 struct nlmsghdr *nlh;
4770 struct sk_security_struct *sksec = sk->sk_security;
4771
4772 if (skb->len < NLMSG_HDRLEN) {
4773 err = -EINVAL;
4774 goto out;
4775 }
4776 nlh = nlmsg_hdr(skb);
4777
4778 err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
4779 if (err) {
4780 if (err == -EINVAL) {
4781 printk(KERN_WARNING
4782 "SELinux: unrecognized netlink message:"
4783 " protocol=%hu nlmsg_type=%hu sclass=%hu\n",
4784 sk->sk_protocol, nlh->nlmsg_type, sksec->sclass);
4785 if (!selinux_enforcing || security_get_allow_unknown())
4786 err = 0;
4787 }
4788
4789 /* Ignore */
4790 if (err == -ENOENT)
4791 err = 0;
4792 goto out;
4793 }
4794
4795 err = sock_has_perm(current, sk, perm);
4796 out:
4797 return err;
4798 }
4799
4800 #ifdef CONFIG_NETFILTER
4801
4802 static unsigned int selinux_ip_forward(struct sk_buff *skb,
4803 const struct net_device *indev,
4804 u16 family)
4805 {
4806 int err;
4807 char *addrp;
4808 u32 peer_sid;
4809 struct common_audit_data ad;
4810 struct lsm_network_audit net = {0,};
4811 u8 secmark_active;
4812 u8 netlbl_active;
4813 u8 peerlbl_active;
4814
4815 if (!selinux_policycap_netpeer)
4816 return NF_ACCEPT;
4817
4818 secmark_active = selinux_secmark_enabled();
4819 netlbl_active = netlbl_enabled();
4820 peerlbl_active = selinux_peerlbl_enabled();
4821 if (!secmark_active && !peerlbl_active)
4822 return NF_ACCEPT;
4823
4824 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
4825 return NF_DROP;
4826
4827 ad.type = LSM_AUDIT_DATA_NET;
4828 ad.u.net = &net;
4829 ad.u.net->netif = indev->ifindex;
4830 ad.u.net->family = family;
4831 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
4832 return NF_DROP;
4833
4834 if (peerlbl_active) {
4835 err = selinux_inet_sys_rcv_skb(dev_net(indev), indev->ifindex,
4836 addrp, family, peer_sid, &ad);
4837 if (err) {
4838 selinux_netlbl_err(skb, err, 1);
4839 return NF_DROP;
4840 }
4841 }
4842
4843 if (secmark_active)
4844 if (avc_has_perm(peer_sid, skb->secmark,
4845 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
4846 return NF_DROP;
4847
4848 if (netlbl_active)
4849 /* we do this in the FORWARD path and not the POST_ROUTING
4850 * path because we want to make sure we apply the necessary
4851 * labeling before IPsec is applied so we can leverage AH
4852 * protection */
4853 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
4854 return NF_DROP;
4855
4856 return NF_ACCEPT;
4857 }
4858
4859 static unsigned int selinux_ipv4_forward(const struct nf_hook_ops *ops,
4860 struct sk_buff *skb,
4861 const struct net_device *in,
4862 const struct net_device *out,
4863 int (*okfn)(struct sk_buff *))
4864 {
4865 return selinux_ip_forward(skb, in, PF_INET);
4866 }
4867
4868 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4869 static unsigned int selinux_ipv6_forward(const struct nf_hook_ops *ops,
4870 struct sk_buff *skb,
4871 const struct net_device *in,
4872 const struct net_device *out,
4873 int (*okfn)(struct sk_buff *))
4874 {
4875 return selinux_ip_forward(skb, in, PF_INET6);
4876 }
4877 #endif /* IPV6 */
4878
4879 static unsigned int selinux_ip_output(struct sk_buff *skb,
4880 u16 family)
4881 {
4882 struct sock *sk;
4883 u32 sid;
4884
4885 if (!netlbl_enabled())
4886 return NF_ACCEPT;
4887
4888 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
4889 * because we want to make sure we apply the necessary labeling
4890 * before IPsec is applied so we can leverage AH protection */
4891 sk = skb->sk;
4892 if (sk) {
4893 struct sk_security_struct *sksec;
4894
4895 if (sk->sk_state == TCP_LISTEN)
4896 /* if the socket is the listening state then this
4897 * packet is a SYN-ACK packet which means it needs to
4898 * be labeled based on the connection/request_sock and
4899 * not the parent socket. unfortunately, we can't
4900 * lookup the request_sock yet as it isn't queued on
4901 * the parent socket until after the SYN-ACK is sent.
4902 * the "solution" is to simply pass the packet as-is
4903 * as any IP option based labeling should be copied
4904 * from the initial connection request (in the IP
4905 * layer). it is far from ideal, but until we get a
4906 * security label in the packet itself this is the
4907 * best we can do. */
4908 return NF_ACCEPT;
4909
4910 /* standard practice, label using the parent socket */
4911 sksec = sk->sk_security;
4912 sid = sksec->sid;
4913 } else
4914 sid = SECINITSID_KERNEL;
4915 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
4916 return NF_DROP;
4917
4918 return NF_ACCEPT;
4919 }
4920
4921 static unsigned int selinux_ipv4_output(const struct nf_hook_ops *ops,
4922 struct sk_buff *skb,
4923 const struct net_device *in,
4924 const struct net_device *out,
4925 int (*okfn)(struct sk_buff *))
4926 {
4927 return selinux_ip_output(skb, PF_INET);
4928 }
4929
4930 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
4931 int ifindex,
4932 u16 family)
4933 {
4934 struct sock *sk = skb->sk;
4935 struct sk_security_struct *sksec;
4936 struct common_audit_data ad;
4937 struct lsm_network_audit net = {0,};
4938 char *addrp;
4939 u8 proto;
4940
4941 if (sk == NULL)
4942 return NF_ACCEPT;
4943 sksec = sk->sk_security;
4944
4945 ad.type = LSM_AUDIT_DATA_NET;
4946 ad.u.net = &net;
4947 ad.u.net->netif = ifindex;
4948 ad.u.net->family = family;
4949 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
4950 return NF_DROP;
4951
4952 if (selinux_secmark_enabled())
4953 if (avc_has_perm(sksec->sid, skb->secmark,
4954 SECCLASS_PACKET, PACKET__SEND, &ad))
4955 return NF_DROP_ERR(-ECONNREFUSED);
4956
4957 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
4958 return NF_DROP_ERR(-ECONNREFUSED);
4959
4960 return NF_ACCEPT;
4961 }
4962
4963 static unsigned int selinux_ip_postroute(struct sk_buff *skb,
4964 const struct net_device *outdev,
4965 u16 family)
4966 {
4967 u32 secmark_perm;
4968 u32 peer_sid;
4969 int ifindex = outdev->ifindex;
4970 struct sock *sk;
4971 struct common_audit_data ad;
4972 struct lsm_network_audit net = {0,};
4973 char *addrp;
4974 u8 secmark_active;
4975 u8 peerlbl_active;
4976
4977 /* If any sort of compatibility mode is enabled then handoff processing
4978 * to the selinux_ip_postroute_compat() function to deal with the
4979 * special handling. We do this in an attempt to keep this function
4980 * as fast and as clean as possible. */
4981 if (!selinux_policycap_netpeer)
4982 return selinux_ip_postroute_compat(skb, ifindex, family);
4983
4984 secmark_active = selinux_secmark_enabled();
4985 peerlbl_active = selinux_peerlbl_enabled();
4986 if (!secmark_active && !peerlbl_active)
4987 return NF_ACCEPT;
4988
4989 sk = skb->sk;
4990
4991 #ifdef CONFIG_XFRM
4992 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
4993 * packet transformation so allow the packet to pass without any checks
4994 * since we'll have another chance to perform access control checks
4995 * when the packet is on it's final way out.
4996 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
4997 * is NULL, in this case go ahead and apply access control.
4998 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
4999 * TCP listening state we cannot wait until the XFRM processing
5000 * is done as we will miss out on the SA label if we do;
5001 * unfortunately, this means more work, but it is only once per
5002 * connection. */
5003 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
5004 !(sk != NULL && sk->sk_state == TCP_LISTEN))
5005 return NF_ACCEPT;
5006 #endif
5007
5008 if (sk == NULL) {
5009 /* Without an associated socket the packet is either coming
5010 * from the kernel or it is being forwarded; check the packet
5011 * to determine which and if the packet is being forwarded
5012 * query the packet directly to determine the security label. */
5013 if (skb->skb_iif) {
5014 secmark_perm = PACKET__FORWARD_OUT;
5015 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5016 return NF_DROP;
5017 } else {
5018 secmark_perm = PACKET__SEND;
5019 peer_sid = SECINITSID_KERNEL;
5020 }
5021 } else if (sk->sk_state == TCP_LISTEN) {
5022 /* Locally generated packet but the associated socket is in the
5023 * listening state which means this is a SYN-ACK packet. In
5024 * this particular case the correct security label is assigned
5025 * to the connection/request_sock but unfortunately we can't
5026 * query the request_sock as it isn't queued on the parent
5027 * socket until after the SYN-ACK packet is sent; the only
5028 * viable choice is to regenerate the label like we do in
5029 * selinux_inet_conn_request(). See also selinux_ip_output()
5030 * for similar problems. */
5031 u32 skb_sid;
5032 struct sk_security_struct *sksec = sk->sk_security;
5033 if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
5034 return NF_DROP;
5035 /* At this point, if the returned skb peerlbl is SECSID_NULL
5036 * and the packet has been through at least one XFRM
5037 * transformation then we must be dealing with the "final"
5038 * form of labeled IPsec packet; since we've already applied
5039 * all of our access controls on this packet we can safely
5040 * pass the packet. */
5041 if (skb_sid == SECSID_NULL) {
5042 switch (family) {
5043 case PF_INET:
5044 if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
5045 return NF_ACCEPT;
5046 break;
5047 case PF_INET6:
5048 if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
5049 return NF_ACCEPT;
5050 break;
5051 default:
5052 return NF_DROP_ERR(-ECONNREFUSED);
5053 }
5054 }
5055 if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
5056 return NF_DROP;
5057 secmark_perm = PACKET__SEND;
5058 } else {
5059 /* Locally generated packet, fetch the security label from the
5060 * associated socket. */
5061 struct sk_security_struct *sksec = sk->sk_security;
5062 peer_sid = sksec->sid;
5063 secmark_perm = PACKET__SEND;
5064 }
5065
5066 ad.type = LSM_AUDIT_DATA_NET;
5067 ad.u.net = &net;
5068 ad.u.net->netif = ifindex;
5069 ad.u.net->family = family;
5070 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5071 return NF_DROP;
5072
5073 if (secmark_active)
5074 if (avc_has_perm(peer_sid, skb->secmark,
5075 SECCLASS_PACKET, secmark_perm, &ad))
5076 return NF_DROP_ERR(-ECONNREFUSED);
5077
5078 if (peerlbl_active) {
5079 u32 if_sid;
5080 u32 node_sid;
5081
5082 if (sel_netif_sid(dev_net(outdev), ifindex, &if_sid))
5083 return NF_DROP;
5084 if (avc_has_perm(peer_sid, if_sid,
5085 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5086 return NF_DROP_ERR(-ECONNREFUSED);
5087
5088 if (sel_netnode_sid(addrp, family, &node_sid))
5089 return NF_DROP;
5090 if (avc_has_perm(peer_sid, node_sid,
5091 SECCLASS_NODE, NODE__SENDTO, &ad))
5092 return NF_DROP_ERR(-ECONNREFUSED);
5093 }
5094
5095 return NF_ACCEPT;
5096 }
5097
5098 static unsigned int selinux_ipv4_postroute(const struct nf_hook_ops *ops,
5099 struct sk_buff *skb,
5100 const struct net_device *in,
5101 const struct net_device *out,
5102 int (*okfn)(struct sk_buff *))
5103 {
5104 return selinux_ip_postroute(skb, out, PF_INET);
5105 }
5106
5107 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5108 static unsigned int selinux_ipv6_postroute(const struct nf_hook_ops *ops,
5109 struct sk_buff *skb,
5110 const struct net_device *in,
5111 const struct net_device *out,
5112 int (*okfn)(struct sk_buff *))
5113 {
5114 return selinux_ip_postroute(skb, out, PF_INET6);
5115 }
5116 #endif /* IPV6 */
5117
5118 #endif /* CONFIG_NETFILTER */
5119
5120 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
5121 {
5122 int err;
5123
5124 err = cap_netlink_send(sk, skb);
5125 if (err)
5126 return err;
5127
5128 return selinux_nlmsg_perm(sk, skb);
5129 }
5130
5131 static int ipc_alloc_security(struct task_struct *task,
5132 struct kern_ipc_perm *perm,
5133 u16 sclass)
5134 {
5135 struct ipc_security_struct *isec;
5136 u32 sid;
5137
5138 isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
5139 if (!isec)
5140 return -ENOMEM;
5141
5142 sid = task_sid(task);
5143 isec->sclass = sclass;
5144 isec->sid = sid;
5145 perm->security = isec;
5146
5147 return 0;
5148 }
5149
5150 static void ipc_free_security(struct kern_ipc_perm *perm)
5151 {
5152 struct ipc_security_struct *isec = perm->security;
5153 perm->security = NULL;
5154 kfree(isec);
5155 }
5156
5157 static int msg_msg_alloc_security(struct msg_msg *msg)
5158 {
5159 struct msg_security_struct *msec;
5160
5161 msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
5162 if (!msec)
5163 return -ENOMEM;
5164
5165 msec->sid = SECINITSID_UNLABELED;
5166 msg->security = msec;
5167
5168 return 0;
5169 }
5170
5171 static void msg_msg_free_security(struct msg_msg *msg)
5172 {
5173 struct msg_security_struct *msec = msg->security;
5174
5175 msg->security = NULL;
5176 kfree(msec);
5177 }
5178
5179 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
5180 u32 perms)
5181 {
5182 struct ipc_security_struct *isec;
5183 struct common_audit_data ad;
5184 u32 sid = current_sid();
5185
5186 isec = ipc_perms->security;
5187
5188 ad.type = LSM_AUDIT_DATA_IPC;
5189 ad.u.ipc_id = ipc_perms->key;
5190
5191 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
5192 }
5193
5194 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
5195 {
5196 return msg_msg_alloc_security(msg);
5197 }
5198
5199 static void selinux_msg_msg_free_security(struct msg_msg *msg)
5200 {
5201 msg_msg_free_security(msg);
5202 }
5203
5204 /* message queue security operations */
5205 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
5206 {
5207 struct ipc_security_struct *isec;
5208 struct common_audit_data ad;
5209 u32 sid = current_sid();
5210 int rc;
5211
5212 rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
5213 if (rc)
5214 return rc;
5215
5216 isec = msq->q_perm.security;
5217
5218 ad.type = LSM_AUDIT_DATA_IPC;
5219 ad.u.ipc_id = msq->q_perm.key;
5220
5221 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5222 MSGQ__CREATE, &ad);
5223 if (rc) {
5224 ipc_free_security(&msq->q_perm);
5225 return rc;
5226 }
5227 return 0;
5228 }
5229
5230 static void selinux_msg_queue_free_security(struct msg_queue *msq)
5231 {
5232 ipc_free_security(&msq->q_perm);
5233 }
5234
5235 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
5236 {
5237 struct ipc_security_struct *isec;
5238 struct common_audit_data ad;
5239 u32 sid = current_sid();
5240
5241 isec = msq->q_perm.security;
5242
5243 ad.type = LSM_AUDIT_DATA_IPC;
5244 ad.u.ipc_id = msq->q_perm.key;
5245
5246 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5247 MSGQ__ASSOCIATE, &ad);
5248 }
5249
5250 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
5251 {
5252 int err;
5253 int perms;
5254
5255 switch (cmd) {
5256 case IPC_INFO:
5257 case MSG_INFO:
5258 /* No specific object, just general system-wide information. */
5259 return task_has_system(current, SYSTEM__IPC_INFO);
5260 case IPC_STAT:
5261 case MSG_STAT:
5262 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
5263 break;
5264 case IPC_SET:
5265 perms = MSGQ__SETATTR;
5266 break;
5267 case IPC_RMID:
5268 perms = MSGQ__DESTROY;
5269 break;
5270 default:
5271 return 0;
5272 }
5273
5274 err = ipc_has_perm(&msq->q_perm, perms);
5275 return err;
5276 }
5277
5278 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
5279 {
5280 struct ipc_security_struct *isec;
5281 struct msg_security_struct *msec;
5282 struct common_audit_data ad;
5283 u32 sid = current_sid();
5284 int rc;
5285
5286 isec = msq->q_perm.security;
5287 msec = msg->security;
5288
5289 /*
5290 * First time through, need to assign label to the message
5291 */
5292 if (msec->sid == SECINITSID_UNLABELED) {
5293 /*
5294 * Compute new sid based on current process and
5295 * message queue this message will be stored in
5296 */
5297 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
5298 NULL, &msec->sid);
5299 if (rc)
5300 return rc;
5301 }
5302
5303 ad.type = LSM_AUDIT_DATA_IPC;
5304 ad.u.ipc_id = msq->q_perm.key;
5305
5306 /* Can this process write to the queue? */
5307 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5308 MSGQ__WRITE, &ad);
5309 if (!rc)
5310 /* Can this process send the message */
5311 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
5312 MSG__SEND, &ad);
5313 if (!rc)
5314 /* Can the message be put in the queue? */
5315 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
5316 MSGQ__ENQUEUE, &ad);
5317
5318 return rc;
5319 }
5320
5321 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
5322 struct task_struct *target,
5323 long type, int mode)
5324 {
5325 struct ipc_security_struct *isec;
5326 struct msg_security_struct *msec;
5327 struct common_audit_data ad;
5328 u32 sid = task_sid(target);
5329 int rc;
5330
5331 isec = msq->q_perm.security;
5332 msec = msg->security;
5333
5334 ad.type = LSM_AUDIT_DATA_IPC;
5335 ad.u.ipc_id = msq->q_perm.key;
5336
5337 rc = avc_has_perm(sid, isec->sid,
5338 SECCLASS_MSGQ, MSGQ__READ, &ad);
5339 if (!rc)
5340 rc = avc_has_perm(sid, msec->sid,
5341 SECCLASS_MSG, MSG__RECEIVE, &ad);
5342 return rc;
5343 }
5344
5345 /* Shared Memory security operations */
5346 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
5347 {
5348 struct ipc_security_struct *isec;
5349 struct common_audit_data ad;
5350 u32 sid = current_sid();
5351 int rc;
5352
5353 rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
5354 if (rc)
5355 return rc;
5356
5357 isec = shp->shm_perm.security;
5358
5359 ad.type = LSM_AUDIT_DATA_IPC;
5360 ad.u.ipc_id = shp->shm_perm.key;
5361
5362 rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5363 SHM__CREATE, &ad);
5364 if (rc) {
5365 ipc_free_security(&shp->shm_perm);
5366 return rc;
5367 }
5368 return 0;
5369 }
5370
5371 static void selinux_shm_free_security(struct shmid_kernel *shp)
5372 {
5373 ipc_free_security(&shp->shm_perm);
5374 }
5375
5376 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
5377 {
5378 struct ipc_security_struct *isec;
5379 struct common_audit_data ad;
5380 u32 sid = current_sid();
5381
5382 isec = shp->shm_perm.security;
5383
5384 ad.type = LSM_AUDIT_DATA_IPC;
5385 ad.u.ipc_id = shp->shm_perm.key;
5386
5387 return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5388 SHM__ASSOCIATE, &ad);
5389 }
5390
5391 /* Note, at this point, shp is locked down */
5392 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
5393 {
5394 int perms;
5395 int err;
5396
5397 switch (cmd) {
5398 case IPC_INFO:
5399 case SHM_INFO:
5400 /* No specific object, just general system-wide information. */
5401 return task_has_system(current, SYSTEM__IPC_INFO);
5402 case IPC_STAT:
5403 case SHM_STAT:
5404 perms = SHM__GETATTR | SHM__ASSOCIATE;
5405 break;
5406 case IPC_SET:
5407 perms = SHM__SETATTR;
5408 break;
5409 case SHM_LOCK:
5410 case SHM_UNLOCK:
5411 perms = SHM__LOCK;
5412 break;
5413 case IPC_RMID:
5414 perms = SHM__DESTROY;
5415 break;
5416 default:
5417 return 0;
5418 }
5419
5420 err = ipc_has_perm(&shp->shm_perm, perms);
5421 return err;
5422 }
5423
5424 static int selinux_shm_shmat(struct shmid_kernel *shp,
5425 char __user *shmaddr, int shmflg)
5426 {
5427 u32 perms;
5428
5429 if (shmflg & SHM_RDONLY)
5430 perms = SHM__READ;
5431 else
5432 perms = SHM__READ | SHM__WRITE;
5433
5434 return ipc_has_perm(&shp->shm_perm, perms);
5435 }
5436
5437 /* Semaphore security operations */
5438 static int selinux_sem_alloc_security(struct sem_array *sma)
5439 {
5440 struct ipc_security_struct *isec;
5441 struct common_audit_data ad;
5442 u32 sid = current_sid();
5443 int rc;
5444
5445 rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
5446 if (rc)
5447 return rc;
5448
5449 isec = sma->sem_perm.security;
5450
5451 ad.type = LSM_AUDIT_DATA_IPC;
5452 ad.u.ipc_id = sma->sem_perm.key;
5453
5454 rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5455 SEM__CREATE, &ad);
5456 if (rc) {
5457 ipc_free_security(&sma->sem_perm);
5458 return rc;
5459 }
5460 return 0;
5461 }
5462
5463 static void selinux_sem_free_security(struct sem_array *sma)
5464 {
5465 ipc_free_security(&sma->sem_perm);
5466 }
5467
5468 static int selinux_sem_associate(struct sem_array *sma, int semflg)
5469 {
5470 struct ipc_security_struct *isec;
5471 struct common_audit_data ad;
5472 u32 sid = current_sid();
5473
5474 isec = sma->sem_perm.security;
5475
5476 ad.type = LSM_AUDIT_DATA_IPC;
5477 ad.u.ipc_id = sma->sem_perm.key;
5478
5479 return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5480 SEM__ASSOCIATE, &ad);
5481 }
5482
5483 /* Note, at this point, sma is locked down */
5484 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5485 {
5486 int err;
5487 u32 perms;
5488
5489 switch (cmd) {
5490 case IPC_INFO:
5491 case SEM_INFO:
5492 /* No specific object, just general system-wide information. */
5493 return task_has_system(current, SYSTEM__IPC_INFO);
5494 case GETPID:
5495 case GETNCNT:
5496 case GETZCNT:
5497 perms = SEM__GETATTR;
5498 break;
5499 case GETVAL:
5500 case GETALL:
5501 perms = SEM__READ;
5502 break;
5503 case SETVAL:
5504 case SETALL:
5505 perms = SEM__WRITE;
5506 break;
5507 case IPC_RMID:
5508 perms = SEM__DESTROY;
5509 break;
5510 case IPC_SET:
5511 perms = SEM__SETATTR;
5512 break;
5513 case IPC_STAT:
5514 case SEM_STAT:
5515 perms = SEM__GETATTR | SEM__ASSOCIATE;
5516 break;
5517 default:
5518 return 0;
5519 }
5520
5521 err = ipc_has_perm(&sma->sem_perm, perms);
5522 return err;
5523 }
5524
5525 static int selinux_sem_semop(struct sem_array *sma,
5526 struct sembuf *sops, unsigned nsops, int alter)
5527 {
5528 u32 perms;
5529
5530 if (alter)
5531 perms = SEM__READ | SEM__WRITE;
5532 else
5533 perms = SEM__READ;
5534
5535 return ipc_has_perm(&sma->sem_perm, perms);
5536 }
5537
5538 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5539 {
5540 u32 av = 0;
5541
5542 av = 0;
5543 if (flag & S_IRUGO)
5544 av |= IPC__UNIX_READ;
5545 if (flag & S_IWUGO)
5546 av |= IPC__UNIX_WRITE;
5547
5548 if (av == 0)
5549 return 0;
5550
5551 return ipc_has_perm(ipcp, av);
5552 }
5553
5554 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5555 {
5556 struct ipc_security_struct *isec = ipcp->security;
5557 *secid = isec->sid;
5558 }
5559
5560 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5561 {
5562 if (inode)
5563 inode_doinit_with_dentry(inode, dentry);
5564 }
5565
5566 static int selinux_getprocattr(struct task_struct *p,
5567 char *name, char **value)
5568 {
5569 const struct task_security_struct *__tsec;
5570 u32 sid;
5571 int error;
5572 unsigned len;
5573
5574 if (current != p) {
5575 error = current_has_perm(p, PROCESS__GETATTR);
5576 if (error)
5577 return error;
5578 }
5579
5580 rcu_read_lock();
5581 __tsec = __task_cred(p)->security;
5582
5583 if (!strcmp(name, "current"))
5584 sid = __tsec->sid;
5585 else if (!strcmp(name, "prev"))
5586 sid = __tsec->osid;
5587 else if (!strcmp(name, "exec"))
5588 sid = __tsec->exec_sid;
5589 else if (!strcmp(name, "fscreate"))
5590 sid = __tsec->create_sid;
5591 else if (!strcmp(name, "keycreate"))
5592 sid = __tsec->keycreate_sid;
5593 else if (!strcmp(name, "sockcreate"))
5594 sid = __tsec->sockcreate_sid;
5595 else
5596 goto invalid;
5597 rcu_read_unlock();
5598
5599 if (!sid)
5600 return 0;
5601
5602 error = security_sid_to_context(sid, value, &len);
5603 if (error)
5604 return error;
5605 return len;
5606
5607 invalid:
5608 rcu_read_unlock();
5609 return -EINVAL;
5610 }
5611
5612 static int selinux_setprocattr(struct task_struct *p,
5613 char *name, void *value, size_t size)
5614 {
5615 struct task_security_struct *tsec;
5616 struct task_struct *tracer;
5617 struct cred *new;
5618 u32 sid = 0, ptsid;
5619 int error;
5620 char *str = value;
5621
5622 if (current != p) {
5623 /* SELinux only allows a process to change its own
5624 security attributes. */
5625 return -EACCES;
5626 }
5627
5628 /*
5629 * Basic control over ability to set these attributes at all.
5630 * current == p, but we'll pass them separately in case the
5631 * above restriction is ever removed.
5632 */
5633 if (!strcmp(name, "exec"))
5634 error = current_has_perm(p, PROCESS__SETEXEC);
5635 else if (!strcmp(name, "fscreate"))
5636 error = current_has_perm(p, PROCESS__SETFSCREATE);
5637 else if (!strcmp(name, "keycreate"))
5638 error = current_has_perm(p, PROCESS__SETKEYCREATE);
5639 else if (!strcmp(name, "sockcreate"))
5640 error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5641 else if (!strcmp(name, "current"))
5642 error = current_has_perm(p, PROCESS__SETCURRENT);
5643 else
5644 error = -EINVAL;
5645 if (error)
5646 return error;
5647
5648 /* Obtain a SID for the context, if one was specified. */
5649 if (size && str[1] && str[1] != '\n') {
5650 if (str[size-1] == '\n') {
5651 str[size-1] = 0;
5652 size--;
5653 }
5654 error = security_context_to_sid(value, size, &sid, GFP_KERNEL);
5655 if (error == -EINVAL && !strcmp(name, "fscreate")) {
5656 if (!capable(CAP_MAC_ADMIN)) {
5657 struct audit_buffer *ab;
5658 size_t audit_size;
5659
5660 /* We strip a nul only if it is at the end, otherwise the
5661 * context contains a nul and we should audit that */
5662 if (str[size - 1] == '\0')
5663 audit_size = size - 1;
5664 else
5665 audit_size = size;
5666 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
5667 audit_log_format(ab, "op=fscreate invalid_context=");
5668 audit_log_n_untrustedstring(ab, value, audit_size);
5669 audit_log_end(ab);
5670
5671 return error;
5672 }
5673 error = security_context_to_sid_force(value, size,
5674 &sid);
5675 }
5676 if (error)
5677 return error;
5678 }
5679
5680 new = prepare_creds();
5681 if (!new)
5682 return -ENOMEM;
5683
5684 /* Permission checking based on the specified context is
5685 performed during the actual operation (execve,
5686 open/mkdir/...), when we know the full context of the
5687 operation. See selinux_bprm_set_creds for the execve
5688 checks and may_create for the file creation checks. The
5689 operation will then fail if the context is not permitted. */
5690 tsec = new->security;
5691 if (!strcmp(name, "exec")) {
5692 tsec->exec_sid = sid;
5693 } else if (!strcmp(name, "fscreate")) {
5694 tsec->create_sid = sid;
5695 } else if (!strcmp(name, "keycreate")) {
5696 error = may_create_key(sid, p);
5697 if (error)
5698 goto abort_change;
5699 tsec->keycreate_sid = sid;
5700 } else if (!strcmp(name, "sockcreate")) {
5701 tsec->sockcreate_sid = sid;
5702 } else if (!strcmp(name, "current")) {
5703 error = -EINVAL;
5704 if (sid == 0)
5705 goto abort_change;
5706
5707 /* Only allow single threaded processes to change context */
5708 error = -EPERM;
5709 if (!current_is_single_threaded()) {
5710 error = security_bounded_transition(tsec->sid, sid);
5711 if (error)
5712 goto abort_change;
5713 }
5714
5715 /* Check permissions for the transition. */
5716 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5717 PROCESS__DYNTRANSITION, NULL);
5718 if (error)
5719 goto abort_change;
5720
5721 /* Check for ptracing, and update the task SID if ok.
5722 Otherwise, leave SID unchanged and fail. */
5723 ptsid = 0;
5724 rcu_read_lock();
5725 tracer = ptrace_parent(p);
5726 if (tracer)
5727 ptsid = task_sid(tracer);
5728 rcu_read_unlock();
5729
5730 if (tracer) {
5731 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5732 PROCESS__PTRACE, NULL);
5733 if (error)
5734 goto abort_change;
5735 }
5736
5737 tsec->sid = sid;
5738 } else {
5739 error = -EINVAL;
5740 goto abort_change;
5741 }
5742
5743 commit_creds(new);
5744 return size;
5745
5746 abort_change:
5747 abort_creds(new);
5748 return error;
5749 }
5750
5751 static int selinux_ismaclabel(const char *name)
5752 {
5753 return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
5754 }
5755
5756 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5757 {
5758 return security_sid_to_context(secid, secdata, seclen);
5759 }
5760
5761 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5762 {
5763 return security_context_to_sid(secdata, seclen, secid, GFP_KERNEL);
5764 }
5765
5766 static void selinux_release_secctx(char *secdata, u32 seclen)
5767 {
5768 kfree(secdata);
5769 }
5770
5771 /*
5772 * called with inode->i_mutex locked
5773 */
5774 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5775 {
5776 return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5777 }
5778
5779 /*
5780 * called with inode->i_mutex locked
5781 */
5782 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
5783 {
5784 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
5785 }
5786
5787 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
5788 {
5789 int len = 0;
5790 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
5791 ctx, true);
5792 if (len < 0)
5793 return len;
5794 *ctxlen = len;
5795 return 0;
5796 }
5797 #ifdef CONFIG_KEYS
5798
5799 static int selinux_key_alloc(struct key *k, const struct cred *cred,
5800 unsigned long flags)
5801 {
5802 const struct task_security_struct *tsec;
5803 struct key_security_struct *ksec;
5804
5805 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
5806 if (!ksec)
5807 return -ENOMEM;
5808
5809 tsec = cred->security;
5810 if (tsec->keycreate_sid)
5811 ksec->sid = tsec->keycreate_sid;
5812 else
5813 ksec->sid = tsec->sid;
5814
5815 k->security = ksec;
5816 return 0;
5817 }
5818
5819 static void selinux_key_free(struct key *k)
5820 {
5821 struct key_security_struct *ksec = k->security;
5822
5823 k->security = NULL;
5824 kfree(ksec);
5825 }
5826
5827 static int selinux_key_permission(key_ref_t key_ref,
5828 const struct cred *cred,
5829 unsigned perm)
5830 {
5831 struct key *key;
5832 struct key_security_struct *ksec;
5833 u32 sid;
5834
5835 /* if no specific permissions are requested, we skip the
5836 permission check. No serious, additional covert channels
5837 appear to be created. */
5838 if (perm == 0)
5839 return 0;
5840
5841 sid = cred_sid(cred);
5842
5843 key = key_ref_to_ptr(key_ref);
5844 ksec = key->security;
5845
5846 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5847 }
5848
5849 static int selinux_key_getsecurity(struct key *key, char **_buffer)
5850 {
5851 struct key_security_struct *ksec = key->security;
5852 char *context = NULL;
5853 unsigned len;
5854 int rc;
5855
5856 rc = security_sid_to_context(ksec->sid, &context, &len);
5857 if (!rc)
5858 rc = len;
5859 *_buffer = context;
5860 return rc;
5861 }
5862
5863 #endif
5864
5865 static struct security_operations selinux_ops = {
5866 .name = "selinux",
5867
5868 .binder_set_context_mgr = selinux_binder_set_context_mgr,
5869 .binder_transaction = selinux_binder_transaction,
5870 .binder_transfer_binder = selinux_binder_transfer_binder,
5871 .binder_transfer_file = selinux_binder_transfer_file,
5872
5873 .ptrace_access_check = selinux_ptrace_access_check,
5874 .ptrace_traceme = selinux_ptrace_traceme,
5875 .capget = selinux_capget,
5876 .capset = selinux_capset,
5877 .capable = selinux_capable,
5878 .quotactl = selinux_quotactl,
5879 .quota_on = selinux_quota_on,
5880 .syslog = selinux_syslog,
5881 .vm_enough_memory = selinux_vm_enough_memory,
5882
5883 .netlink_send = selinux_netlink_send,
5884
5885 .bprm_set_creds = selinux_bprm_set_creds,
5886 .bprm_committing_creds = selinux_bprm_committing_creds,
5887 .bprm_committed_creds = selinux_bprm_committed_creds,
5888 .bprm_secureexec = selinux_bprm_secureexec,
5889
5890 .sb_alloc_security = selinux_sb_alloc_security,
5891 .sb_free_security = selinux_sb_free_security,
5892 .sb_copy_data = selinux_sb_copy_data,
5893 .sb_remount = selinux_sb_remount,
5894 .sb_kern_mount = selinux_sb_kern_mount,
5895 .sb_show_options = selinux_sb_show_options,
5896 .sb_statfs = selinux_sb_statfs,
5897 .sb_mount = selinux_mount,
5898 .sb_umount = selinux_umount,
5899 .sb_set_mnt_opts = selinux_set_mnt_opts,
5900 .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts,
5901 .sb_parse_opts_str = selinux_parse_opts_str,
5902
5903 .dentry_init_security = selinux_dentry_init_security,
5904
5905 .inode_alloc_security = selinux_inode_alloc_security,
5906 .inode_free_security = selinux_inode_free_security,
5907 .inode_init_security = selinux_inode_init_security,
5908 .inode_create = selinux_inode_create,
5909 .inode_link = selinux_inode_link,
5910 .inode_unlink = selinux_inode_unlink,
5911 .inode_symlink = selinux_inode_symlink,
5912 .inode_mkdir = selinux_inode_mkdir,
5913 .inode_rmdir = selinux_inode_rmdir,
5914 .inode_mknod = selinux_inode_mknod,
5915 .inode_rename = selinux_inode_rename,
5916 .inode_readlink = selinux_inode_readlink,
5917 .inode_follow_link = selinux_inode_follow_link,
5918 .inode_permission = selinux_inode_permission,
5919 .inode_setattr = selinux_inode_setattr,
5920 .inode_getattr = selinux_inode_getattr,
5921 .inode_setxattr = selinux_inode_setxattr,
5922 .inode_post_setxattr = selinux_inode_post_setxattr,
5923 .inode_getxattr = selinux_inode_getxattr,
5924 .inode_listxattr = selinux_inode_listxattr,
5925 .inode_removexattr = selinux_inode_removexattr,
5926 .inode_getsecurity = selinux_inode_getsecurity,
5927 .inode_setsecurity = selinux_inode_setsecurity,
5928 .inode_listsecurity = selinux_inode_listsecurity,
5929 .inode_getsecid = selinux_inode_getsecid,
5930
5931 .file_permission = selinux_file_permission,
5932 .file_alloc_security = selinux_file_alloc_security,
5933 .file_free_security = selinux_file_free_security,
5934 .file_ioctl = selinux_file_ioctl,
5935 .mmap_file = selinux_mmap_file,
5936 .mmap_addr = selinux_mmap_addr,
5937 .file_mprotect = selinux_file_mprotect,
5938 .file_lock = selinux_file_lock,
5939 .file_fcntl = selinux_file_fcntl,
5940 .file_set_fowner = selinux_file_set_fowner,
5941 .file_send_sigiotask = selinux_file_send_sigiotask,
5942 .file_receive = selinux_file_receive,
5943
5944 .file_open = selinux_file_open,
5945
5946 .task_create = selinux_task_create,
5947 .cred_alloc_blank = selinux_cred_alloc_blank,
5948 .cred_free = selinux_cred_free,
5949 .cred_prepare = selinux_cred_prepare,
5950 .cred_transfer = selinux_cred_transfer,
5951 .kernel_act_as = selinux_kernel_act_as,
5952 .kernel_create_files_as = selinux_kernel_create_files_as,
5953 .kernel_module_request = selinux_kernel_module_request,
5954 .task_setpgid = selinux_task_setpgid,
5955 .task_getpgid = selinux_task_getpgid,
5956 .task_getsid = selinux_task_getsid,
5957 .task_getsecid = selinux_task_getsecid,
5958 .task_setnice = selinux_task_setnice,
5959 .task_setioprio = selinux_task_setioprio,
5960 .task_getioprio = selinux_task_getioprio,
5961 .task_setrlimit = selinux_task_setrlimit,
5962 .task_setscheduler = selinux_task_setscheduler,
5963 .task_getscheduler = selinux_task_getscheduler,
5964 .task_movememory = selinux_task_movememory,
5965 .task_kill = selinux_task_kill,
5966 .task_wait = selinux_task_wait,
5967 .task_to_inode = selinux_task_to_inode,
5968
5969 .ipc_permission = selinux_ipc_permission,
5970 .ipc_getsecid = selinux_ipc_getsecid,
5971
5972 .msg_msg_alloc_security = selinux_msg_msg_alloc_security,
5973 .msg_msg_free_security = selinux_msg_msg_free_security,
5974
5975 .msg_queue_alloc_security = selinux_msg_queue_alloc_security,
5976 .msg_queue_free_security = selinux_msg_queue_free_security,
5977 .msg_queue_associate = selinux_msg_queue_associate,
5978 .msg_queue_msgctl = selinux_msg_queue_msgctl,
5979 .msg_queue_msgsnd = selinux_msg_queue_msgsnd,
5980 .msg_queue_msgrcv = selinux_msg_queue_msgrcv,
5981
5982 .shm_alloc_security = selinux_shm_alloc_security,
5983 .shm_free_security = selinux_shm_free_security,
5984 .shm_associate = selinux_shm_associate,
5985 .shm_shmctl = selinux_shm_shmctl,
5986 .shm_shmat = selinux_shm_shmat,
5987
5988 .sem_alloc_security = selinux_sem_alloc_security,
5989 .sem_free_security = selinux_sem_free_security,
5990 .sem_associate = selinux_sem_associate,
5991 .sem_semctl = selinux_sem_semctl,
5992 .sem_semop = selinux_sem_semop,
5993
5994 .d_instantiate = selinux_d_instantiate,
5995
5996 .getprocattr = selinux_getprocattr,
5997 .setprocattr = selinux_setprocattr,
5998
5999 .ismaclabel = selinux_ismaclabel,
6000 .secid_to_secctx = selinux_secid_to_secctx,
6001 .secctx_to_secid = selinux_secctx_to_secid,
6002 .release_secctx = selinux_release_secctx,
6003 .inode_notifysecctx = selinux_inode_notifysecctx,
6004 .inode_setsecctx = selinux_inode_setsecctx,
6005 .inode_getsecctx = selinux_inode_getsecctx,
6006
6007 .unix_stream_connect = selinux_socket_unix_stream_connect,
6008 .unix_may_send = selinux_socket_unix_may_send,
6009
6010 .socket_create = selinux_socket_create,
6011 .socket_post_create = selinux_socket_post_create,
6012 .socket_bind = selinux_socket_bind,
6013 .socket_connect = selinux_socket_connect,
6014 .socket_listen = selinux_socket_listen,
6015 .socket_accept = selinux_socket_accept,
6016 .socket_sendmsg = selinux_socket_sendmsg,
6017 .socket_recvmsg = selinux_socket_recvmsg,
6018 .socket_getsockname = selinux_socket_getsockname,
6019 .socket_getpeername = selinux_socket_getpeername,
6020 .socket_getsockopt = selinux_socket_getsockopt,
6021 .socket_setsockopt = selinux_socket_setsockopt,
6022 .socket_shutdown = selinux_socket_shutdown,
6023 .socket_sock_rcv_skb = selinux_socket_sock_rcv_skb,
6024 .socket_getpeersec_stream = selinux_socket_getpeersec_stream,
6025 .socket_getpeersec_dgram = selinux_socket_getpeersec_dgram,
6026 .sk_alloc_security = selinux_sk_alloc_security,
6027 .sk_free_security = selinux_sk_free_security,
6028 .sk_clone_security = selinux_sk_clone_security,
6029 .sk_getsecid = selinux_sk_getsecid,
6030 .sock_graft = selinux_sock_graft,
6031 .inet_conn_request = selinux_inet_conn_request,
6032 .inet_csk_clone = selinux_inet_csk_clone,
6033 .inet_conn_established = selinux_inet_conn_established,
6034 .secmark_relabel_packet = selinux_secmark_relabel_packet,
6035 .secmark_refcount_inc = selinux_secmark_refcount_inc,
6036 .secmark_refcount_dec = selinux_secmark_refcount_dec,
6037 .req_classify_flow = selinux_req_classify_flow,
6038 .tun_dev_alloc_security = selinux_tun_dev_alloc_security,
6039 .tun_dev_free_security = selinux_tun_dev_free_security,
6040 .tun_dev_create = selinux_tun_dev_create,
6041 .tun_dev_attach_queue = selinux_tun_dev_attach_queue,
6042 .tun_dev_attach = selinux_tun_dev_attach,
6043 .tun_dev_open = selinux_tun_dev_open,
6044 .skb_owned_by = selinux_skb_owned_by,
6045
6046 #ifdef CONFIG_SECURITY_NETWORK_XFRM
6047 .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc,
6048 .xfrm_policy_clone_security = selinux_xfrm_policy_clone,
6049 .xfrm_policy_free_security = selinux_xfrm_policy_free,
6050 .xfrm_policy_delete_security = selinux_xfrm_policy_delete,
6051 .xfrm_state_alloc = selinux_xfrm_state_alloc,
6052 .xfrm_state_alloc_acquire = selinux_xfrm_state_alloc_acquire,
6053 .xfrm_state_free_security = selinux_xfrm_state_free,
6054 .xfrm_state_delete_security = selinux_xfrm_state_delete,
6055 .xfrm_policy_lookup = selinux_xfrm_policy_lookup,
6056 .xfrm_state_pol_flow_match = selinux_xfrm_state_pol_flow_match,
6057 .xfrm_decode_session = selinux_xfrm_decode_session,
6058 #endif
6059
6060 #ifdef CONFIG_KEYS
6061 .key_alloc = selinux_key_alloc,
6062 .key_free = selinux_key_free,
6063 .key_permission = selinux_key_permission,
6064 .key_getsecurity = selinux_key_getsecurity,
6065 #endif
6066
6067 #ifdef CONFIG_AUDIT
6068 .audit_rule_init = selinux_audit_rule_init,
6069 .audit_rule_known = selinux_audit_rule_known,
6070 .audit_rule_match = selinux_audit_rule_match,
6071 .audit_rule_free = selinux_audit_rule_free,
6072 #endif
6073 };
6074
6075 static __init int selinux_init(void)
6076 {
6077 if (!security_module_enable(&selinux_ops)) {
6078 selinux_enabled = 0;
6079 return 0;
6080 }
6081
6082 if (!selinux_enabled) {
6083 printk(KERN_INFO "SELinux: Disabled at boot.\n");
6084 return 0;
6085 }
6086
6087 printk(KERN_INFO "SELinux: Initializing.\n");
6088
6089 /* Set the security state for the initial task. */
6090 cred_init_security();
6091
6092 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
6093
6094 sel_inode_cache = kmem_cache_create("selinux_inode_security",
6095 sizeof(struct inode_security_struct),
6096 0, SLAB_PANIC, NULL);
6097 avc_init();
6098
6099 if (register_security(&selinux_ops))
6100 panic("SELinux: Unable to register with kernel.\n");
6101
6102 if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
6103 panic("SELinux: Unable to register AVC netcache callback\n");
6104
6105 if (selinux_enforcing)
6106 printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n");
6107 else
6108 printk(KERN_DEBUG "SELinux: Starting in permissive mode\n");
6109
6110 return 0;
6111 }
6112
6113 static void delayed_superblock_init(struct super_block *sb, void *unused)
6114 {
6115 superblock_doinit(sb, NULL);
6116 }
6117
6118 void selinux_complete_init(void)
6119 {
6120 printk(KERN_DEBUG "SELinux: Completing initialization.\n");
6121
6122 /* Set up any superblocks initialized prior to the policy load. */
6123 printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n");
6124 iterate_supers(delayed_superblock_init, NULL);
6125 }
6126
6127 /* SELinux requires early initialization in order to label
6128 all processes and objects when they are created. */
6129 security_initcall(selinux_init);
6130
6131 #if defined(CONFIG_NETFILTER)
6132
6133 static struct nf_hook_ops selinux_nf_ops[] = {
6134 {
6135 .hook = selinux_ipv4_postroute,
6136 .owner = THIS_MODULE,
6137 .pf = NFPROTO_IPV4,
6138 .hooknum = NF_INET_POST_ROUTING,
6139 .priority = NF_IP_PRI_SELINUX_LAST,
6140 },
6141 {
6142 .hook = selinux_ipv4_forward,
6143 .owner = THIS_MODULE,
6144 .pf = NFPROTO_IPV4,
6145 .hooknum = NF_INET_FORWARD,
6146 .priority = NF_IP_PRI_SELINUX_FIRST,
6147 },
6148 {
6149 .hook = selinux_ipv4_output,
6150 .owner = THIS_MODULE,
6151 .pf = NFPROTO_IPV4,
6152 .hooknum = NF_INET_LOCAL_OUT,
6153 .priority = NF_IP_PRI_SELINUX_FIRST,
6154 },
6155 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
6156 {
6157 .hook = selinux_ipv6_postroute,
6158 .owner = THIS_MODULE,
6159 .pf = NFPROTO_IPV6,
6160 .hooknum = NF_INET_POST_ROUTING,
6161 .priority = NF_IP6_PRI_SELINUX_LAST,
6162 },
6163 {
6164 .hook = selinux_ipv6_forward,
6165 .owner = THIS_MODULE,
6166 .pf = NFPROTO_IPV6,
6167 .hooknum = NF_INET_FORWARD,
6168 .priority = NF_IP6_PRI_SELINUX_FIRST,
6169 },
6170 #endif /* IPV6 */
6171 };
6172
6173 static int __init selinux_nf_ip_init(void)
6174 {
6175 int err;
6176
6177 if (!selinux_enabled)
6178 return 0;
6179
6180 printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n");
6181
6182 err = nf_register_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
6183 if (err)
6184 panic("SELinux: nf_register_hooks: error %d\n", err);
6185
6186 return 0;
6187 }
6188
6189 __initcall(selinux_nf_ip_init);
6190
6191 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
6192 static void selinux_nf_ip_exit(void)
6193 {
6194 printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n");
6195
6196 nf_unregister_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
6197 }
6198 #endif
6199
6200 #else /* CONFIG_NETFILTER */
6201
6202 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
6203 #define selinux_nf_ip_exit()
6204 #endif
6205
6206 #endif /* CONFIG_NETFILTER */
6207
6208 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
6209 static int selinux_disabled;
6210
6211 int selinux_disable(void)
6212 {
6213 if (ss_initialized) {
6214 /* Not permitted after initial policy load. */
6215 return -EINVAL;
6216 }
6217
6218 if (selinux_disabled) {
6219 /* Only do this once. */
6220 return -EINVAL;
6221 }
6222
6223 printk(KERN_INFO "SELinux: Disabled at runtime.\n");
6224
6225 selinux_disabled = 1;
6226 selinux_enabled = 0;
6227
6228 reset_security_ops();
6229
6230 /* Try to destroy the avc node cache */
6231 avc_disable();
6232
6233 /* Unregister netfilter hooks. */
6234 selinux_nf_ip_exit();
6235
6236 /* Unregister selinuxfs. */
6237 exit_sel_fs();
6238
6239 return 0;
6240 }
6241 #endif
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