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[PATCH] small kernel/sched.c cleanup
[linux.git] / security / selinux / hooks.c
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1da177e4
LT		 1/*
2 * NSA Security-Enhanced Linux (SELinux) security module
3 *
4 * This file contains the SELinux hook function implementations.
5 *
6 * Authors: Stephen Smalley, <[email protected]>
7 * Chris Vance, <[email protected]>
8 * Wayne Salamon, <[email protected]>
9 * James Morris <[email protected]>
10 *
11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12 * Copyright (C) 2003 Red Hat, Inc., James Morris <[email protected]>
13 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
14 * <[email protected]>
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License version 2,
18 * as published by the Free Software Foundation.
19 */
20
1da177e4
LT		 21#include <linux/module.h>
22#include <linux/init.h>
23#include <linux/kernel.h>
24#include <linux/ptrace.h>
25#include <linux/errno.h>
26#include <linux/sched.h>
27#include <linux/security.h>
28#include <linux/xattr.h>
29#include <linux/capability.h>
30#include <linux/unistd.h>
31#include <linux/mm.h>
32#include <linux/mman.h>
33#include <linux/slab.h>
34#include <linux/pagemap.h>
35#include <linux/swap.h>
36#include <linux/smp_lock.h>
37#include <linux/spinlock.h>
38#include <linux/syscalls.h>
39#include <linux/file.h>
40#include <linux/namei.h>
41#include <linux/mount.h>
42#include <linux/ext2_fs.h>
43#include <linux/proc_fs.h>
44#include <linux/kd.h>
45#include <linux/netfilter_ipv4.h>
46#include <linux/netfilter_ipv6.h>
47#include <linux/tty.h>
48#include <net/icmp.h>
49#include <net/ip.h> /* for sysctl_local_port_range[] */
50#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
51#include <asm/uaccess.h>
52#include <asm/semaphore.h>
53#include <asm/ioctls.h>
54#include <linux/bitops.h>
55#include <linux/interrupt.h>
56#include <linux/netdevice.h> /* for network interface checks */
57#include <linux/netlink.h>
58#include <linux/tcp.h>
59#include <linux/udp.h>
60#include <linux/quota.h>
61#include <linux/un.h> /* for Unix socket types */
62#include <net/af_unix.h> /* for Unix socket types */
63#include <linux/parser.h>
64#include <linux/nfs_mount.h>
65#include <net/ipv6.h>
66#include <linux/hugetlb.h>
67#include <linux/personality.h>
68#include <linux/sysctl.h>
69#include <linux/audit.h>
6931dfc9 70#include <linux/string.h>
877ce7c1 71#include <linux/selinux.h>
1da177e4
LT		 72
73#include "avc.h"
74#include "objsec.h"
75#include "netif.h"
d28d1e08 76#include "xfrm.h"
1da177e4
LT		 77
78#define XATTR_SELINUX_SUFFIX "selinux"
79#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
80
81extern unsigned int policydb_loaded_version;
82extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
4e5ab4cb 83extern int selinux_compat_net;
1da177e4
LT		 84
85#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
86int selinux_enforcing = 0;
87
88static int __init enforcing_setup(char *str)
89{
90 selinux_enforcing = simple_strtol(str,NULL,0);
91 return 1;
92}
93__setup("enforcing=", enforcing_setup);
94#endif
95
96#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
97int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
98
99static int __init selinux_enabled_setup(char *str)
100{
101 selinux_enabled = simple_strtol(str, NULL, 0);
102 return 1;
103}
104__setup("selinux=", selinux_enabled_setup);
30d55280
SS		 105#else
106int selinux_enabled = 1;
1da177e4
LT		 107#endif
108
109/* Original (dummy) security module. */
110static struct security_operations *original_ops = NULL;
111
112/* Minimal support for a secondary security module,
113 just to allow the use of the dummy or capability modules.
114 The owlsm module can alternatively be used as a secondary
115 module as long as CONFIG_OWLSM_FD is not enabled. */
116static struct security_operations *secondary_ops = NULL;
117
118/* Lists of inode and superblock security structures initialized
119 before the policy was loaded. */
120static LIST_HEAD(superblock_security_head);
121static DEFINE_SPINLOCK(sb_security_lock);
122
7cae7e26
JM		 123static kmem_cache_t *sel_inode_cache;
124
8c8570fb
DK		 125/* Return security context for a given sid or just the context
126 length if the buffer is null or length is 0 */
127static int selinux_getsecurity(u32 sid, void *buffer, size_t size)
128{
129 char *context;
130 unsigned len;
131 int rc;
132
133 rc = security_sid_to_context(sid, &context, &len);
134 if (rc)
135 return rc;
136
137 if (!buffer || !size)
138 goto getsecurity_exit;
139
140 if (size < len) {
141 len = -ERANGE;
142 goto getsecurity_exit;
143 }
144 memcpy(buffer, context, len);
145
146getsecurity_exit:
147 kfree(context);
148 return len;
149}
150
1da177e4
LT		 151/* Allocate and free functions for each kind of security blob. */
152
153static int task_alloc_security(struct task_struct *task)
154{
155 struct task_security_struct *tsec;
156
89d155ef 157 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
1da177e4
LT		 158 if (!tsec)
159 return -ENOMEM;
160
1da177e4
LT		 161 tsec->task = task;
162 tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED;
163 task->security = tsec;
164
165 return 0;
166}
167
168static void task_free_security(struct task_struct *task)
169{
170 struct task_security_struct *tsec = task->security;
1da177e4
LT		 171 task->security = NULL;
172 kfree(tsec);
173}
174
175static int inode_alloc_security(struct inode *inode)
176{
177 struct task_security_struct *tsec = current->security;
178 struct inode_security_struct *isec;
179
7cae7e26 180 isec = kmem_cache_alloc(sel_inode_cache, SLAB_KERNEL);
1da177e4
LT		 181 if (!isec)
182 return -ENOMEM;
183
7cae7e26 184 memset(isec, 0, sizeof(*isec));
1da177e4
LT		 185 init_MUTEX(&isec->sem);
186 INIT_LIST_HEAD(&isec->list);
1da177e4
LT		 187 isec->inode = inode;
188 isec->sid = SECINITSID_UNLABELED;
189 isec->sclass = SECCLASS_FILE;
9ac49d22 190 isec->task_sid = tsec->sid;
1da177e4
LT		 191 inode->i_security = isec;
192
193 return 0;
194}
195
196static void inode_free_security(struct inode *inode)
197{
198 struct inode_security_struct *isec = inode->i_security;
199 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
200
1da177e4
LT		 201 spin_lock(&sbsec->isec_lock);
202 if (!list_empty(&isec->list))
203 list_del_init(&isec->list);
204 spin_unlock(&sbsec->isec_lock);
205
206 inode->i_security = NULL;
7cae7e26 207 kmem_cache_free(sel_inode_cache, isec);
1da177e4
LT		 208}
209
210static int file_alloc_security(struct file *file)
211{
212 struct task_security_struct *tsec = current->security;
213 struct file_security_struct *fsec;
214
26d2a4be 215 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
1da177e4
LT		 216 if (!fsec)
217 return -ENOMEM;
218
1da177e4 219 fsec->file = file;
9ac49d22
SS		 220 fsec->sid = tsec->sid;
221 fsec->fown_sid = tsec->sid;
1da177e4
LT		 222 file->f_security = fsec;
223
224 return 0;
225}
226
227static void file_free_security(struct file *file)
228{
229 struct file_security_struct *fsec = file->f_security;
1da177e4
LT		 230 file->f_security = NULL;
231 kfree(fsec);
232}
233
234static int superblock_alloc_security(struct super_block *sb)
235{
236 struct superblock_security_struct *sbsec;
237
89d155ef 238 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
1da177e4
LT		 239 if (!sbsec)
240 return -ENOMEM;
241
1da177e4
LT		 242 init_MUTEX(&sbsec->sem);
243 INIT_LIST_HEAD(&sbsec->list);
244 INIT_LIST_HEAD(&sbsec->isec_head);
245 spin_lock_init(&sbsec->isec_lock);
1da177e4
LT		 246 sbsec->sb = sb;
247 sbsec->sid = SECINITSID_UNLABELED;
248 sbsec->def_sid = SECINITSID_FILE;
249 sb->s_security = sbsec;
250
251 return 0;
252}
253
254static void superblock_free_security(struct super_block *sb)
255{
256 struct superblock_security_struct *sbsec = sb->s_security;
257
1da177e4
LT		 258 spin_lock(&sb_security_lock);
259 if (!list_empty(&sbsec->list))
260 list_del_init(&sbsec->list);
261 spin_unlock(&sb_security_lock);
262
263 sb->s_security = NULL;
264 kfree(sbsec);
265}
266
7d877f3b 267static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
1da177e4
LT		 268{
269 struct sk_security_struct *ssec;
270
271 if (family != PF_UNIX)
272 return 0;
273
89d155ef 274 ssec = kzalloc(sizeof(*ssec), priority);
1da177e4
LT		 275 if (!ssec)
276 return -ENOMEM;
277
1da177e4
LT		 278 ssec->sk = sk;
279 ssec->peer_sid = SECINITSID_UNLABELED;
280 sk->sk_security = ssec;
281
282 return 0;
283}
284
285static void sk_free_security(struct sock *sk)
286{
287 struct sk_security_struct *ssec = sk->sk_security;
288
9ac49d22 289 if (sk->sk_family != PF_UNIX)
1da177e4
LT		 290 return;
291
292 sk->sk_security = NULL;
293 kfree(ssec);
294}
1da177e4
LT		 295
296/* The security server must be initialized before
297 any labeling or access decisions can be provided. */
298extern int ss_initialized;
299
300/* The file system's label must be initialized prior to use. */
301
302static char *labeling_behaviors[6] = {
303 "uses xattr",
304 "uses transition SIDs",
305 "uses task SIDs",
306 "uses genfs_contexts",
307 "not configured for labeling",
308 "uses mountpoint labeling",
309};
310
311static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
312
313static inline int inode_doinit(struct inode *inode)
314{
315 return inode_doinit_with_dentry(inode, NULL);
316}
317
318enum {
319 Opt_context = 1,
320 Opt_fscontext = 2,
321 Opt_defcontext = 4,
322};
323
324static match_table_t tokens = {
325 {Opt_context, "context=%s"},
326 {Opt_fscontext, "fscontext=%s"},
327 {Opt_defcontext, "defcontext=%s"},
328};
329
330#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
331
332static int try_context_mount(struct super_block *sb, void *data)
333{
334 char *context = NULL, *defcontext = NULL;
335 const char *name;
336 u32 sid;
337 int alloc = 0, rc = 0, seen = 0;
338 struct task_security_struct *tsec = current->security;
339 struct superblock_security_struct *sbsec = sb->s_security;
340
341 if (!data)
342 goto out;
343
344 name = sb->s_type->name;
345
346 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) {
347
348 /* NFS we understand. */
349 if (!strcmp(name, "nfs")) {
350 struct nfs_mount_data *d = data;
351
352 if (d->version < NFS_MOUNT_VERSION)
353 goto out;
354
355 if (d->context[0]) {
356 context = d->context;
357 seen |= Opt_context;
358 }
359 } else
360 goto out;
361
362 } else {
363 /* Standard string-based options. */
364 char *p, *options = data;
365
366 while ((p = strsep(&options, ",")) != NULL) {
367 int token;
368 substring_t args[MAX_OPT_ARGS];
369
370 if (!*p)
371 continue;
372
373 token = match_token(p, tokens, args);
374
375 switch (token) {
376 case Opt_context:
377 if (seen) {
378 rc = -EINVAL;
379 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
380 goto out_free;
381 }
382 context = match_strdup(&args[0]);
383 if (!context) {
384 rc = -ENOMEM;
385 goto out_free;
386 }
387 if (!alloc)
388 alloc = 1;
389 seen |= Opt_context;
390 break;
391
392 case Opt_fscontext:
393 if (seen & (Opt_context|Opt_fscontext)) {
394 rc = -EINVAL;
395 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
396 goto out_free;
397 }
398 context = match_strdup(&args[0]);
399 if (!context) {
400 rc = -ENOMEM;
401 goto out_free;
402 }
403 if (!alloc)
404 alloc = 1;
405 seen |= Opt_fscontext;
406 break;
407
408 case Opt_defcontext:
409 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
410 rc = -EINVAL;
411 printk(KERN_WARNING "SELinux: "
412 "defcontext option is invalid "
413 "for this filesystem type\n");
414 goto out_free;
415 }
416 if (seen & (Opt_context|Opt_defcontext)) {
417 rc = -EINVAL;
418 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
419 goto out_free;
420 }
421 defcontext = match_strdup(&args[0]);
422 if (!defcontext) {
423 rc = -ENOMEM;
424 goto out_free;
425 }
426 if (!alloc)
427 alloc = 1;
428 seen |= Opt_defcontext;
429 break;
430
431 default:
432 rc = -EINVAL;
433 printk(KERN_WARNING "SELinux: unknown mount "
434 "option\n");
435 goto out_free;
436
437 }
438 }
439 }
440
441 if (!seen)
442 goto out;
443
444 if (context) {
445 rc = security_context_to_sid(context, strlen(context), &sid);
446 if (rc) {
447 printk(KERN_WARNING "SELinux: security_context_to_sid"
448 "(%s) failed for (dev %s, type %s) errno=%d\n",
449 context, sb->s_id, name, rc);
450 goto out_free;
451 }
452
453 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
454 FILESYSTEM__RELABELFROM, NULL);
455 if (rc)
456 goto out_free;
457
458 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
459 FILESYSTEM__RELABELTO, NULL);
460 if (rc)
461 goto out_free;
462
463 sbsec->sid = sid;
464
465 if (seen & Opt_context)
466 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
467 }
468
469 if (defcontext) {
470 rc = security_context_to_sid(defcontext, strlen(defcontext), &sid);
471 if (rc) {
472 printk(KERN_WARNING "SELinux: security_context_to_sid"
473 "(%s) failed for (dev %s, type %s) errno=%d\n",
474 defcontext, sb->s_id, name, rc);
475 goto out_free;
476 }
477
478 if (sid == sbsec->def_sid)
479 goto out_free;
480
481 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
482 FILESYSTEM__RELABELFROM, NULL);
483 if (rc)
484 goto out_free;
485
486 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
487 FILESYSTEM__ASSOCIATE, NULL);
488 if (rc)
489 goto out_free;
490
491 sbsec->def_sid = sid;
492 }
493
494out_free:
495 if (alloc) {
496 kfree(context);
497 kfree(defcontext);
498 }
499out:
500 return rc;
501}
502
503static int superblock_doinit(struct super_block *sb, void *data)
504{
505 struct superblock_security_struct *sbsec = sb->s_security;
506 struct dentry *root = sb->s_root;
507 struct inode *inode = root->d_inode;
508 int rc = 0;
509
510 down(&sbsec->sem);
511 if (sbsec->initialized)
512 goto out;
513
514 if (!ss_initialized) {
515 /* Defer initialization until selinux_complete_init,
516 after the initial policy is loaded and the security
517 server is ready to handle calls. */
518 spin_lock(&sb_security_lock);
519 if (list_empty(&sbsec->list))
520 list_add(&sbsec->list, &superblock_security_head);
521 spin_unlock(&sb_security_lock);
522 goto out;
523 }
524
525 /* Determine the labeling behavior to use for this filesystem type. */
526 rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid);
527 if (rc) {
528 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
529 __FUNCTION__, sb->s_type->name, rc);
530 goto out;
531 }
532
533 rc = try_context_mount(sb, data);
534 if (rc)
535 goto out;
536
537 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
538 /* Make sure that the xattr handler exists and that no
539 error other than -ENODATA is returned by getxattr on
540 the root directory. -ENODATA is ok, as this may be
541 the first boot of the SELinux kernel before we have
542 assigned xattr values to the filesystem. */
543 if (!inode->i_op->getxattr) {
544 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
545 "xattr support\n", sb->s_id, sb->s_type->name);
546 rc = -EOPNOTSUPP;
547 goto out;
548 }
549 rc = inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
550 if (rc < 0 && rc != -ENODATA) {
551 if (rc == -EOPNOTSUPP)
552 printk(KERN_WARNING "SELinux: (dev %s, type "
553 "%s) has no security xattr handler\n",
554 sb->s_id, sb->s_type->name);
555 else
556 printk(KERN_WARNING "SELinux: (dev %s, type "
557 "%s) getxattr errno %d\n", sb->s_id,
558 sb->s_type->name, -rc);
559 goto out;
560 }
561 }
562
563 if (strcmp(sb->s_type->name, "proc") == 0)
564 sbsec->proc = 1;
565
566 sbsec->initialized = 1;
567
568 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) {
569 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), unknown behavior\n",
570 sb->s_id, sb->s_type->name);
571 }
572 else {
573 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), %s\n",
574 sb->s_id, sb->s_type->name,
575 labeling_behaviors[sbsec->behavior-1]);
576 }
577
578 /* Initialize the root inode. */
579 rc = inode_doinit_with_dentry(sb->s_root->d_inode, sb->s_root);
580
581 /* Initialize any other inodes associated with the superblock, e.g.
582 inodes created prior to initial policy load or inodes created
583 during get_sb by a pseudo filesystem that directly
584 populates itself. */
585 spin_lock(&sbsec->isec_lock);
586next_inode:
587 if (!list_empty(&sbsec->isec_head)) {
588 struct inode_security_struct *isec =
589 list_entry(sbsec->isec_head.next,
590 struct inode_security_struct, list);
591 struct inode *inode = isec->inode;
592 spin_unlock(&sbsec->isec_lock);
593 inode = igrab(inode);
594 if (inode) {
595 if (!IS_PRIVATE (inode))
596 inode_doinit(inode);
597 iput(inode);
598 }
599 spin_lock(&sbsec->isec_lock);
600 list_del_init(&isec->list);
601 goto next_inode;
602 }
603 spin_unlock(&sbsec->isec_lock);
604out:
605 up(&sbsec->sem);
606 return rc;
607}
608
609static inline u16 inode_mode_to_security_class(umode_t mode)
610{
611 switch (mode & S_IFMT) {
612 case S_IFSOCK:
613 return SECCLASS_SOCK_FILE;
614 case S_IFLNK:
615 return SECCLASS_LNK_FILE;
616 case S_IFREG:
617 return SECCLASS_FILE;
618 case S_IFBLK:
619 return SECCLASS_BLK_FILE;
620 case S_IFDIR:
621 return SECCLASS_DIR;
622 case S_IFCHR:
623 return SECCLASS_CHR_FILE;
624 case S_IFIFO:
625 return SECCLASS_FIFO_FILE;
626
627 }
628
629 return SECCLASS_FILE;
630}
631
13402580
JM		 632static inline int default_protocol_stream(int protocol)
633{
634 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
635}
636
637static inline int default_protocol_dgram(int protocol)
638{
639 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
640}
641
1da177e4
LT		 642static inline u16 socket_type_to_security_class(int family, int type, int protocol)
643{
644 switch (family) {
645 case PF_UNIX:
646 switch (type) {
647 case SOCK_STREAM:
648 case SOCK_SEQPACKET:
649 return SECCLASS_UNIX_STREAM_SOCKET;
650 case SOCK_DGRAM:
651 return SECCLASS_UNIX_DGRAM_SOCKET;
652 }
653 break;
654 case PF_INET:
655 case PF_INET6:
656 switch (type) {
657 case SOCK_STREAM:
13402580
JM		 658 if (default_protocol_stream(protocol))
659 return SECCLASS_TCP_SOCKET;
660 else
661 return SECCLASS_RAWIP_SOCKET;
1da177e4 662 case SOCK_DGRAM:
13402580
JM		 663 if (default_protocol_dgram(protocol))
664 return SECCLASS_UDP_SOCKET;
665 else
666 return SECCLASS_RAWIP_SOCKET;
667 default:
1da177e4
LT		 668 return SECCLASS_RAWIP_SOCKET;
669 }
670 break;
671 case PF_NETLINK:
672 switch (protocol) {
673 case NETLINK_ROUTE:
674 return SECCLASS_NETLINK_ROUTE_SOCKET;
675 case NETLINK_FIREWALL:
676 return SECCLASS_NETLINK_FIREWALL_SOCKET;
216efaaa 677 case NETLINK_INET_DIAG:
1da177e4
LT		 678 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
679 case NETLINK_NFLOG:
680 return SECCLASS_NETLINK_NFLOG_SOCKET;
681 case NETLINK_XFRM:
682 return SECCLASS_NETLINK_XFRM_SOCKET;
683 case NETLINK_SELINUX:
684 return SECCLASS_NETLINK_SELINUX_SOCKET;
685 case NETLINK_AUDIT:
686 return SECCLASS_NETLINK_AUDIT_SOCKET;
687 case NETLINK_IP6_FW:
688 return SECCLASS_NETLINK_IP6FW_SOCKET;
689 case NETLINK_DNRTMSG:
690 return SECCLASS_NETLINK_DNRT_SOCKET;
0c9b7942
JM		 691 case NETLINK_KOBJECT_UEVENT:
692 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1da177e4
LT		 693 default:
694 return SECCLASS_NETLINK_SOCKET;
695 }
696 case PF_PACKET:
697 return SECCLASS_PACKET_SOCKET;
698 case PF_KEY:
699 return SECCLASS_KEY_SOCKET;
3e3ff15e
CP		 700 case PF_APPLETALK:
701 return SECCLASS_APPLETALK_SOCKET;
1da177e4
LT		 702 }
703
704 return SECCLASS_SOCKET;
705}
706
707#ifdef CONFIG_PROC_FS
708static int selinux_proc_get_sid(struct proc_dir_entry *de,
709 u16 tclass,
710 u32 *sid)
711{
712 int buflen, rc;
713 char *buffer, *path, *end;
714
715 buffer = (char*)__get_free_page(GFP_KERNEL);
716 if (!buffer)
717 return -ENOMEM;
718
719 buflen = PAGE_SIZE;
720 end = buffer+buflen;
721 *--end = '\0';
722 buflen--;
723 path = end-1;
724 *path = '/';
725 while (de && de != de->parent) {
726 buflen -= de->namelen + 1;
727 if (buflen < 0)
728 break;
729 end -= de->namelen;
730 memcpy(end, de->name, de->namelen);
731 *--end = '/';
732 path = end;
733 de = de->parent;
734 }
735 rc = security_genfs_sid("proc", path, tclass, sid);
736 free_page((unsigned long)buffer);
737 return rc;
738}
739#else
740static int selinux_proc_get_sid(struct proc_dir_entry *de,
741 u16 tclass,
742 u32 *sid)
743{
744 return -EINVAL;
745}
746#endif
747
748/* The inode's security attributes must be initialized before first use. */
749static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
750{
751 struct superblock_security_struct *sbsec = NULL;
752 struct inode_security_struct *isec = inode->i_security;
753 u32 sid;
754 struct dentry *dentry;
755#define INITCONTEXTLEN 255
756 char *context = NULL;
757 unsigned len = 0;
758 int rc = 0;
759 int hold_sem = 0;
760
761 if (isec->initialized)
762 goto out;
763
764 down(&isec->sem);
765 hold_sem = 1;
766 if (isec->initialized)
767 goto out;
768
769 sbsec = inode->i_sb->s_security;
770 if (!sbsec->initialized) {
771 /* Defer initialization until selinux_complete_init,
772 after the initial policy is loaded and the security
773 server is ready to handle calls. */
774 spin_lock(&sbsec->isec_lock);
775 if (list_empty(&isec->list))
776 list_add(&isec->list, &sbsec->isec_head);
777 spin_unlock(&sbsec->isec_lock);
778 goto out;
779 }
780
781 switch (sbsec->behavior) {
782 case SECURITY_FS_USE_XATTR:
783 if (!inode->i_op->getxattr) {
784 isec->sid = sbsec->def_sid;
785 break;
786 }
787
788 /* Need a dentry, since the xattr API requires one.
789 Life would be simpler if we could just pass the inode. */
790 if (opt_dentry) {
791 /* Called from d_instantiate or d_splice_alias. */
792 dentry = dget(opt_dentry);
793 } else {
794 /* Called from selinux_complete_init, try to find a dentry. */
795 dentry = d_find_alias(inode);
796 }
797 if (!dentry) {
798 printk(KERN_WARNING "%s: no dentry for dev=%s "
799 "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id,
800 inode->i_ino);
801 goto out;
802 }
803
804 len = INITCONTEXTLEN;
805 context = kmalloc(len, GFP_KERNEL);
806 if (!context) {
807 rc = -ENOMEM;
808 dput(dentry);
809 goto out;
810 }
811 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
812 context, len);
813 if (rc == -ERANGE) {
814 /* Need a larger buffer. Query for the right size. */
815 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
816 NULL, 0);
817 if (rc < 0) {
818 dput(dentry);
819 goto out;
820 }
821 kfree(context);
822 len = rc;
823 context = kmalloc(len, GFP_KERNEL);
824 if (!context) {
825 rc = -ENOMEM;
826 dput(dentry);
827 goto out;
828 }
829 rc = inode->i_op->getxattr(dentry,
830 XATTR_NAME_SELINUX,
831 context, len);
832 }
833 dput(dentry);
834 if (rc < 0) {
835 if (rc != -ENODATA) {
836 printk(KERN_WARNING "%s: getxattr returned "
837 "%d for dev=%s ino=%ld\n", __FUNCTION__,
838 -rc, inode->i_sb->s_id, inode->i_ino);
839 kfree(context);
840 goto out;
841 }
842 /* Map ENODATA to the default file SID */
843 sid = sbsec->def_sid;
844 rc = 0;
845 } else {
f5c1d5b2
JM		 846 rc = security_context_to_sid_default(context, rc, &sid,
847 sbsec->def_sid);
1da177e4
LT		 848 if (rc) {
849 printk(KERN_WARNING "%s: context_to_sid(%s) "
850 "returned %d for dev=%s ino=%ld\n",
851 __FUNCTION__, context, -rc,
852 inode->i_sb->s_id, inode->i_ino);
853 kfree(context);
854 /* Leave with the unlabeled SID */
855 rc = 0;
856 break;
857 }
858 }
859 kfree(context);
860 isec->sid = sid;
861 break;
862 case SECURITY_FS_USE_TASK:
863 isec->sid = isec->task_sid;
864 break;
865 case SECURITY_FS_USE_TRANS:
866 /* Default to the fs SID. */
867 isec->sid = sbsec->sid;
868
869 /* Try to obtain a transition SID. */
870 isec->sclass = inode_mode_to_security_class(inode->i_mode);
871 rc = security_transition_sid(isec->task_sid,
872 sbsec->sid,
873 isec->sclass,
874 &sid);
875 if (rc)
876 goto out;
877 isec->sid = sid;
878 break;
879 default:
880 /* Default to the fs SID. */
881 isec->sid = sbsec->sid;
882
883 if (sbsec->proc) {
884 struct proc_inode *proci = PROC_I(inode);
885 if (proci->pde) {
886 isec->sclass = inode_mode_to_security_class(inode->i_mode);
887 rc = selinux_proc_get_sid(proci->pde,
888 isec->sclass,
889 &sid);
890 if (rc)
891 goto out;
892 isec->sid = sid;
893 }
894 }
895 break;
896 }
897
898 isec->initialized = 1;
899
900out:
901 if (isec->sclass == SECCLASS_FILE)
902 isec->sclass = inode_mode_to_security_class(inode->i_mode);
903
904 if (hold_sem)
905 up(&isec->sem);
906 return rc;
907}
908
909/* Convert a Linux signal to an access vector. */
910static inline u32 signal_to_av(int sig)
911{
912 u32 perm = 0;
913
914 switch (sig) {
915 case SIGCHLD:
916 /* Commonly granted from child to parent. */
917 perm = PROCESS__SIGCHLD;
918 break;
919 case SIGKILL:
920 /* Cannot be caught or ignored */
921 perm = PROCESS__SIGKILL;
922 break;
923 case SIGSTOP:
924 /* Cannot be caught or ignored */
925 perm = PROCESS__SIGSTOP;
926 break;
927 default:
928 /* All other signals. */
929 perm = PROCESS__SIGNAL;
930 break;
931 }
932
933 return perm;
934}
935
936/* Check permission betweeen a pair of tasks, e.g. signal checks,
937 fork check, ptrace check, etc. */
938static int task_has_perm(struct task_struct *tsk1,
939 struct task_struct *tsk2,
940 u32 perms)
941{
942 struct task_security_struct *tsec1, *tsec2;
943
944 tsec1 = tsk1->security;
945 tsec2 = tsk2->security;
946 return avc_has_perm(tsec1->sid, tsec2->sid,
947 SECCLASS_PROCESS, perms, NULL);
948}
949
950/* Check whether a task is allowed to use a capability. */
951static int task_has_capability(struct task_struct *tsk,
952 int cap)
953{
954 struct task_security_struct *tsec;
955 struct avc_audit_data ad;
956
957 tsec = tsk->security;
958
959 AVC_AUDIT_DATA_INIT(&ad,CAP);
960 ad.tsk = tsk;
961 ad.u.cap = cap;
962
963 return avc_has_perm(tsec->sid, tsec->sid,
964 SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad);
965}
966
967/* Check whether a task is allowed to use a system operation. */
968static int task_has_system(struct task_struct *tsk,
969 u32 perms)
970{
971 struct task_security_struct *tsec;
972
973 tsec = tsk->security;
974
975 return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
976 SECCLASS_SYSTEM, perms, NULL);
977}
978
979/* Check whether a task has a particular permission to an inode.
980 The 'adp' parameter is optional and allows other audit
981 data to be passed (e.g. the dentry). */
982static int inode_has_perm(struct task_struct *tsk,
983 struct inode *inode,
984 u32 perms,
985 struct avc_audit_data *adp)
986{
987 struct task_security_struct *tsec;
988 struct inode_security_struct *isec;
989 struct avc_audit_data ad;
990
991 tsec = tsk->security;
992 isec = inode->i_security;
993
994 if (!adp) {
995 adp = &ad;
996 AVC_AUDIT_DATA_INIT(&ad, FS);
997 ad.u.fs.inode = inode;
998 }
999
1000 return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
1001}
1002
1003/* Same as inode_has_perm, but pass explicit audit data containing
1004 the dentry to help the auditing code to more easily generate the
1005 pathname if needed. */
1006static inline int dentry_has_perm(struct task_struct *tsk,
1007 struct vfsmount *mnt,
1008 struct dentry *dentry,
1009 u32 av)
1010{
1011 struct inode *inode = dentry->d_inode;
1012 struct avc_audit_data ad;
1013 AVC_AUDIT_DATA_INIT(&ad,FS);
1014 ad.u.fs.mnt = mnt;
1015 ad.u.fs.dentry = dentry;
1016 return inode_has_perm(tsk, inode, av, &ad);
1017}
1018
1019/* Check whether a task can use an open file descriptor to
1020 access an inode in a given way. Check access to the
1021 descriptor itself, and then use dentry_has_perm to
1022 check a particular permission to the file.
1023 Access to the descriptor is implicitly granted if it
1024 has the same SID as the process. If av is zero, then
1025 access to the file is not checked, e.g. for cases
1026 where only the descriptor is affected like seek. */
858119e1 1027static int file_has_perm(struct task_struct *tsk,
1da177e4
LT		 1028 struct file *file,
1029 u32 av)
1030{
1031 struct task_security_struct *tsec = tsk->security;
1032 struct file_security_struct *fsec = file->f_security;
1033 struct vfsmount *mnt = file->f_vfsmnt;
1034 struct dentry *dentry = file->f_dentry;
1035 struct inode *inode = dentry->d_inode;
1036 struct avc_audit_data ad;
1037 int rc;
1038
1039 AVC_AUDIT_DATA_INIT(&ad, FS);
1040 ad.u.fs.mnt = mnt;
1041 ad.u.fs.dentry = dentry;
1042
1043 if (tsec->sid != fsec->sid) {
1044 rc = avc_has_perm(tsec->sid, fsec->sid,
1045 SECCLASS_FD,
1046 FD__USE,
1047 &ad);
1048 if (rc)
1049 return rc;
1050 }
1051
1052 /* av is zero if only checking access to the descriptor. */
1053 if (av)
1054 return inode_has_perm(tsk, inode, av, &ad);
1055
1056 return 0;
1057}
1058
1059/* Check whether a task can create a file. */
1060static int may_create(struct inode *dir,
1061 struct dentry *dentry,
1062 u16 tclass)
1063{
1064 struct task_security_struct *tsec;
1065 struct inode_security_struct *dsec;
1066 struct superblock_security_struct *sbsec;
1067 u32 newsid;
1068 struct avc_audit_data ad;
1069 int rc;
1070
1071 tsec = current->security;
1072 dsec = dir->i_security;
1073 sbsec = dir->i_sb->s_security;
1074
1075 AVC_AUDIT_DATA_INIT(&ad, FS);
1076 ad.u.fs.dentry = dentry;
1077
1078 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
1079 DIR__ADD_NAME | DIR__SEARCH,
1080 &ad);
1081 if (rc)
1082 return rc;
1083
1084 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1085 newsid = tsec->create_sid;
1086 } else {
1087 rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
1088 &newsid);
1089 if (rc)
1090 return rc;
1091 }
1092
1093 rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
1094 if (rc)
1095 return rc;
1096
1097 return avc_has_perm(newsid, sbsec->sid,
1098 SECCLASS_FILESYSTEM,
1099 FILESYSTEM__ASSOCIATE, &ad);
1100}
1101
4eb582cf
ML		 1102/* Check whether a task can create a key. */
1103static int may_create_key(u32 ksid,
1104 struct task_struct *ctx)
1105{
1106 struct task_security_struct *tsec;
1107
1108 tsec = ctx->security;
1109
1110 return avc_has_perm(tsec->sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1111}
1112
1da177e4
LT		 1113#define MAY_LINK 0
1114#define MAY_UNLINK 1
1115#define MAY_RMDIR 2
1116
1117/* Check whether a task can link, unlink, or rmdir a file/directory. */
1118static int may_link(struct inode *dir,
1119 struct dentry *dentry,
1120 int kind)
1121
1122{
1123 struct task_security_struct *tsec;
1124 struct inode_security_struct *dsec, *isec;
1125 struct avc_audit_data ad;
1126 u32 av;
1127 int rc;
1128
1129 tsec = current->security;
1130 dsec = dir->i_security;
1131 isec = dentry->d_inode->i_security;
1132
1133 AVC_AUDIT_DATA_INIT(&ad, FS);
1134 ad.u.fs.dentry = dentry;
1135
1136 av = DIR__SEARCH;
1137 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1138 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
1139 if (rc)
1140 return rc;
1141
1142 switch (kind) {
1143 case MAY_LINK:
1144 av = FILE__LINK;
1145 break;
1146 case MAY_UNLINK:
1147 av = FILE__UNLINK;
1148 break;
1149 case MAY_RMDIR:
1150 av = DIR__RMDIR;
1151 break;
1152 default:
1153 printk(KERN_WARNING "may_link: unrecognized kind %d\n", kind);
1154 return 0;
1155 }
1156
1157 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
1158 return rc;
1159}
1160
1161static inline int may_rename(struct inode *old_dir,
1162 struct dentry *old_dentry,
1163 struct inode *new_dir,
1164 struct dentry *new_dentry)
1165{
1166 struct task_security_struct *tsec;
1167 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1168 struct avc_audit_data ad;
1169 u32 av;
1170 int old_is_dir, new_is_dir;
1171 int rc;
1172
1173 tsec = current->security;
1174 old_dsec = old_dir->i_security;
1175 old_isec = old_dentry->d_inode->i_security;
1176 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1177 new_dsec = new_dir->i_security;
1178
1179 AVC_AUDIT_DATA_INIT(&ad, FS);
1180
1181 ad.u.fs.dentry = old_dentry;
1182 rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
1183 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1184 if (rc)
1185 return rc;
1186 rc = avc_has_perm(tsec->sid, old_isec->sid,
1187 old_isec->sclass, FILE__RENAME, &ad);
1188 if (rc)
1189 return rc;
1190 if (old_is_dir && new_dir != old_dir) {
1191 rc = avc_has_perm(tsec->sid, old_isec->sid,
1192 old_isec->sclass, DIR__REPARENT, &ad);
1193 if (rc)
1194 return rc;
1195 }
1196
1197 ad.u.fs.dentry = new_dentry;
1198 av = DIR__ADD_NAME | DIR__SEARCH;
1199 if (new_dentry->d_inode)
1200 av |= DIR__REMOVE_NAME;
1201 rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1202 if (rc)
1203 return rc;
1204 if (new_dentry->d_inode) {
1205 new_isec = new_dentry->d_inode->i_security;
1206 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1207 rc = avc_has_perm(tsec->sid, new_isec->sid,
1208 new_isec->sclass,
1209 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1210 if (rc)
1211 return rc;
1212 }
1213
1214 return 0;
1215}
1216
1217/* Check whether a task can perform a filesystem operation. */
1218static int superblock_has_perm(struct task_struct *tsk,
1219 struct super_block *sb,
1220 u32 perms,
1221 struct avc_audit_data *ad)
1222{
1223 struct task_security_struct *tsec;
1224 struct superblock_security_struct *sbsec;
1225
1226 tsec = tsk->security;
1227 sbsec = sb->s_security;
1228 return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
1229 perms, ad);
1230}
1231
1232/* Convert a Linux mode and permission mask to an access vector. */
1233static inline u32 file_mask_to_av(int mode, int mask)
1234{
1235 u32 av = 0;
1236
1237 if ((mode & S_IFMT) != S_IFDIR) {
1238 if (mask & MAY_EXEC)
1239 av |= FILE__EXECUTE;
1240 if (mask & MAY_READ)
1241 av |= FILE__READ;
1242
1243 if (mask & MAY_APPEND)
1244 av |= FILE__APPEND;
1245 else if (mask & MAY_WRITE)
1246 av |= FILE__WRITE;
1247
1248 } else {
1249 if (mask & MAY_EXEC)
1250 av |= DIR__SEARCH;
1251 if (mask & MAY_WRITE)
1252 av |= DIR__WRITE;
1253 if (mask & MAY_READ)
1254 av |= DIR__READ;
1255 }
1256
1257 return av;
1258}
1259
1260/* Convert a Linux file to an access vector. */
1261static inline u32 file_to_av(struct file *file)
1262{
1263 u32 av = 0;
1264
1265 if (file->f_mode & FMODE_READ)
1266 av |= FILE__READ;
1267 if (file->f_mode & FMODE_WRITE) {
1268 if (file->f_flags & O_APPEND)
1269 av |= FILE__APPEND;
1270 else
1271 av |= FILE__WRITE;
1272 }
1273
1274 return av;
1275}
1276
1277/* Set an inode's SID to a specified value. */
1278static int inode_security_set_sid(struct inode *inode, u32 sid)
1279{
1280 struct inode_security_struct *isec = inode->i_security;
1281 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
1282
1283 if (!sbsec->initialized) {
1284 /* Defer initialization to selinux_complete_init. */
1285 return 0;
1286 }
1287
1288 down(&isec->sem);
1289 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1290 isec->sid = sid;
1291 isec->initialized = 1;
1292 up(&isec->sem);
1293 return 0;
1294}
1295
1da177e4
LT		 1296/* Hook functions begin here. */
1297
1298static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
1299{
1300 struct task_security_struct *psec = parent->security;
1301 struct task_security_struct *csec = child->security;
1302 int rc;
1303
1304 rc = secondary_ops->ptrace(parent,child);
1305 if (rc)
1306 return rc;
1307
1308 rc = task_has_perm(parent, child, PROCESS__PTRACE);
1309 /* Save the SID of the tracing process for later use in apply_creds. */
341c2d80 1310 if (!(child->ptrace & PT_PTRACED) && !rc)
1da177e4
LT		 1311 csec->ptrace_sid = psec->sid;
1312 return rc;
1313}
1314
1315static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1316 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1317{
1318 int error;
1319
1320 error = task_has_perm(current, target, PROCESS__GETCAP);
1321 if (error)
1322 return error;
1323
1324 return secondary_ops->capget(target, effective, inheritable, permitted);
1325}
1326
1327static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective,
1328 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1329{
1330 int error;
1331
1332 error = secondary_ops->capset_check(target, effective, inheritable, permitted);
1333 if (error)
1334 return error;
1335
1336 return task_has_perm(current, target, PROCESS__SETCAP);
1337}
1338
1339static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
1340 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1341{
1342 secondary_ops->capset_set(target, effective, inheritable, permitted);
1343}
1344
1345static int selinux_capable(struct task_struct *tsk, int cap)
1346{
1347 int rc;
1348
1349 rc = secondary_ops->capable(tsk, cap);
1350 if (rc)
1351 return rc;
1352
1353 return task_has_capability(tsk,cap);
1354}
1355
1356static int selinux_sysctl(ctl_table *table, int op)
1357{
1358 int error = 0;
1359 u32 av;
1360 struct task_security_struct *tsec;
1361 u32 tsid;
1362 int rc;
1363
1364 rc = secondary_ops->sysctl(table, op);
1365 if (rc)
1366 return rc;
1367
1368 tsec = current->security;
1369
1370 rc = selinux_proc_get_sid(table->de, (op == 001) ?
1371 SECCLASS_DIR : SECCLASS_FILE, &tsid);
1372 if (rc) {
1373 /* Default to the well-defined sysctl SID. */
1374 tsid = SECINITSID_SYSCTL;
1375 }
1376
1377 /* The op values are "defined" in sysctl.c, thereby creating
1378 * a bad coupling between this module and sysctl.c */
1379 if(op == 001) {
1380 error = avc_has_perm(tsec->sid, tsid,
1381 SECCLASS_DIR, DIR__SEARCH, NULL);
1382 } else {
1383 av = 0;
1384 if (op & 004)
1385 av |= FILE__READ;
1386 if (op & 002)
1387 av |= FILE__WRITE;
1388 if (av)
1389 error = avc_has_perm(tsec->sid, tsid,
1390 SECCLASS_FILE, av, NULL);
1391 }
1392
1393 return error;
1394}
1395
1396static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1397{
1398 int rc = 0;
1399
1400 if (!sb)
1401 return 0;
1402
1403 switch (cmds) {
1404 case Q_SYNC:
1405 case Q_QUOTAON:
1406 case Q_QUOTAOFF:
1407 case Q_SETINFO:
1408 case Q_SETQUOTA:
1409 rc = superblock_has_perm(current,
1410 sb,
1411 FILESYSTEM__QUOTAMOD, NULL);
1412 break;
1413 case Q_GETFMT:
1414 case Q_GETINFO:
1415 case Q_GETQUOTA:
1416 rc = superblock_has_perm(current,
1417 sb,
1418 FILESYSTEM__QUOTAGET, NULL);
1419 break;
1420 default:
1421 rc = 0; /* let the kernel handle invalid cmds */
1422 break;
1423 }
1424 return rc;
1425}
1426
1427static int selinux_quota_on(struct dentry *dentry)
1428{
1429 return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1430}
1431
1432static int selinux_syslog(int type)
1433{
1434 int rc;
1435
1436 rc = secondary_ops->syslog(type);
1437 if (rc)
1438 return rc;
1439
1440 switch (type) {
1441 case 3: /* Read last kernel messages */
1442 case 10: /* Return size of the log buffer */
1443 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1444 break;
1445 case 6: /* Disable logging to console */
1446 case 7: /* Enable logging to console */
1447 case 8: /* Set level of messages printed to console */
1448 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1449 break;
1450 case 0: /* Close log */
1451 case 1: /* Open log */
1452 case 2: /* Read from log */
1453 case 4: /* Read/clear last kernel messages */
1454 case 5: /* Clear ring buffer */
1455 default:
1456 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1457 break;
1458 }
1459 return rc;
1460}
1461
1462/*
1463 * Check that a process has enough memory to allocate a new virtual
1464 * mapping. 0 means there is enough memory for the allocation to
1465 * succeed and -ENOMEM implies there is not.
1466 *
1467 * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1468 * if the capability is granted, but __vm_enough_memory requires 1 if
1469 * the capability is granted.
1470 *
1471 * Do not audit the selinux permission check, as this is applied to all
1472 * processes that allocate mappings.
1473 */
1474static int selinux_vm_enough_memory(long pages)
1475{
1476 int rc, cap_sys_admin = 0;
1477 struct task_security_struct *tsec = current->security;
1478
1479 rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
1480 if (rc == 0)
1481 rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1482 SECCLASS_CAPABILITY,
1483 CAP_TO_MASK(CAP_SYS_ADMIN),
1484 NULL);
1485
1486 if (rc == 0)
1487 cap_sys_admin = 1;
1488
1489 return __vm_enough_memory(pages, cap_sys_admin);
1490}
1491
1492/* binprm security operations */
1493
1494static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1495{
1496 struct bprm_security_struct *bsec;
1497
89d155ef 1498 bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1da177e4
LT		 1499 if (!bsec)
1500 return -ENOMEM;
1501
1da177e4
LT		 1502 bsec->bprm = bprm;
1503 bsec->sid = SECINITSID_UNLABELED;
1504 bsec->set = 0;
1505
1506 bprm->security = bsec;
1507 return 0;
1508}
1509
1510static int selinux_bprm_set_security(struct linux_binprm *bprm)
1511{
1512 struct task_security_struct *tsec;
1513 struct inode *inode = bprm->file->f_dentry->d_inode;
1514 struct inode_security_struct *isec;
1515 struct bprm_security_struct *bsec;
1516 u32 newsid;
1517 struct avc_audit_data ad;
1518 int rc;
1519
1520 rc = secondary_ops->bprm_set_security(bprm);
1521 if (rc)
1522 return rc;
1523
1524 bsec = bprm->security;
1525
1526 if (bsec->set)
1527 return 0;
1528
1529 tsec = current->security;
1530 isec = inode->i_security;
1531
1532 /* Default to the current task SID. */
1533 bsec->sid = tsec->sid;
1534
28eba5bf 1535 /* Reset fs, key, and sock SIDs on execve. */
1da177e4 1536 tsec->create_sid = 0;
28eba5bf 1537 tsec->keycreate_sid = 0;
42c3e03e 1538 tsec->sockcreate_sid = 0;
1da177e4
LT		 1539
1540 if (tsec->exec_sid) {
1541 newsid = tsec->exec_sid;
1542 /* Reset exec SID on execve. */
1543 tsec->exec_sid = 0;
1544 } else {
1545 /* Check for a default transition on this program. */
1546 rc = security_transition_sid(tsec->sid, isec->sid,
1547 SECCLASS_PROCESS, &newsid);
1548 if (rc)
1549 return rc;
1550 }
1551
1552 AVC_AUDIT_DATA_INIT(&ad, FS);
1553 ad.u.fs.mnt = bprm->file->f_vfsmnt;
1554 ad.u.fs.dentry = bprm->file->f_dentry;
1555
1556 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
1557 newsid = tsec->sid;
1558
1559 if (tsec->sid == newsid) {
1560 rc = avc_has_perm(tsec->sid, isec->sid,
1561 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1562 if (rc)
1563 return rc;
1564 } else {
1565 /* Check permissions for the transition. */
1566 rc = avc_has_perm(tsec->sid, newsid,
1567 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1568 if (rc)
1569 return rc;
1570
1571 rc = avc_has_perm(newsid, isec->sid,
1572 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1573 if (rc)
1574 return rc;
1575
1576 /* Clear any possibly unsafe personality bits on exec: */
1577 current->personality &= ~PER_CLEAR_ON_SETID;
1578
1579 /* Set the security field to the new SID. */
1580 bsec->sid = newsid;
1581 }
1582
1583 bsec->set = 1;
1584 return 0;
1585}
1586
1587static int selinux_bprm_check_security (struct linux_binprm *bprm)
1588{
1589 return secondary_ops->bprm_check_security(bprm);
1590}
1591
1592
1593static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1594{
1595 struct task_security_struct *tsec = current->security;
1596 int atsecure = 0;
1597
1598 if (tsec->osid != tsec->sid) {
1599 /* Enable secure mode for SIDs transitions unless
1600 the noatsecure permission is granted between
1601 the two SIDs, i.e. ahp returns 0. */
1602 atsecure = avc_has_perm(tsec->osid, tsec->sid,
1603 SECCLASS_PROCESS,
1604 PROCESS__NOATSECURE, NULL);
1605 }
1606
1607 return (atsecure || secondary_ops->bprm_secureexec(bprm));
1608}
1609
1610static void selinux_bprm_free_security(struct linux_binprm *bprm)
1611{
9a5f04bf 1612 kfree(bprm->security);
1da177e4 1613 bprm->security = NULL;
1da177e4
LT		 1614}
1615
1616extern struct vfsmount *selinuxfs_mount;
1617extern struct dentry *selinux_null;
1618
1619/* Derived from fs/exec.c:flush_old_files. */
1620static inline void flush_unauthorized_files(struct files_struct * files)
1621{
1622 struct avc_audit_data ad;
1623 struct file *file, *devnull = NULL;
1624 struct tty_struct *tty = current->signal->tty;
badf1662 1625 struct fdtable *fdt;
1da177e4
LT		 1626 long j = -1;
1627
1628 if (tty) {
1629 file_list_lock();
2f512016 1630 file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
1da177e4
LT		 1631 if (file) {
1632 /* Revalidate access to controlling tty.
1633 Use inode_has_perm on the tty inode directly rather
1634 than using file_has_perm, as this particular open
1635 file may belong to another process and we are only
1636 interested in the inode-based check here. */
1637 struct inode *inode = file->f_dentry->d_inode;
1638 if (inode_has_perm(current, inode,
1639 FILE__READ | FILE__WRITE, NULL)) {
1640 /* Reset controlling tty. */
1641 current->signal->tty = NULL;
1642 current->signal->tty_old_pgrp = 0;
1643 }
1644 }
1645 file_list_unlock();
1646 }
1647
1648 /* Revalidate access to inherited open files. */
1649
1650 AVC_AUDIT_DATA_INIT(&ad,FS);
1651
1652 spin_lock(&files->file_lock);
1653 for (;;) {
1654 unsigned long set, i;
1655 int fd;
1656
1657 j++;
1658 i = j * __NFDBITS;
badf1662
DS		 1659 fdt = files_fdtable(files);
1660 if (i >= fdt->max_fds || i >= fdt->max_fdset)
1da177e4 1661 break;
badf1662 1662 set = fdt->open_fds->fds_bits[j];
1da177e4
LT		 1663 if (!set)
1664 continue;
1665 spin_unlock(&files->file_lock);
1666 for ( ; set ; i++,set >>= 1) {
1667 if (set & 1) {
1668 file = fget(i);
1669 if (!file)
1670 continue;
1671 if (file_has_perm(current,
1672 file,
1673 file_to_av(file))) {
1674 sys_close(i);
1675 fd = get_unused_fd();
1676 if (fd != i) {
1677 if (fd >= 0)
1678 put_unused_fd(fd);
1679 fput(file);
1680 continue;
1681 }
1682 if (devnull) {
095975da 1683 get_file(devnull);
1da177e4
LT		 1684 } else {
1685 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1686 if (!devnull) {
1687 put_unused_fd(fd);
1688 fput(file);
1689 continue;
1690 }
1691 }
1692 fd_install(fd, devnull);
1693 }
1694 fput(file);
1695 }
1696 }
1697 spin_lock(&files->file_lock);
1698
1699 }
1700 spin_unlock(&files->file_lock);
1701}
1702
1703static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1704{
1705 struct task_security_struct *tsec;
1706 struct bprm_security_struct *bsec;
1707 u32 sid;
1708 int rc;
1709
1710 secondary_ops->bprm_apply_creds(bprm, unsafe);
1711
1712 tsec = current->security;
1713
1714 bsec = bprm->security;
1715 sid = bsec->sid;
1716
1717 tsec->osid = tsec->sid;
1718 bsec->unsafe = 0;
1719 if (tsec->sid != sid) {
1720 /* Check for shared state. If not ok, leave SID
1721 unchanged and kill. */
1722 if (unsafe & LSM_UNSAFE_SHARE) {
1723 rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1724 PROCESS__SHARE, NULL);
1725 if (rc) {
1726 bsec->unsafe = 1;
1727 return;
1728 }
1729 }
1730
1731 /* Check for ptracing, and update the task SID if ok.
1732 Otherwise, leave SID unchanged and kill. */
1733 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1734 rc = avc_has_perm(tsec->ptrace_sid, sid,
1735 SECCLASS_PROCESS, PROCESS__PTRACE,
1736 NULL);
1737 if (rc) {
1738 bsec->unsafe = 1;
1739 return;
1740 }
1741 }
1742 tsec->sid = sid;
1743 }
1744}
1745
1746/*
1747 * called after apply_creds without the task lock held
1748 */
1749static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1750{
1751 struct task_security_struct *tsec;
1752 struct rlimit *rlim, *initrlim;
1753 struct itimerval itimer;
1754 struct bprm_security_struct *bsec;
1755 int rc, i;
1756
1757 tsec = current->security;
1758 bsec = bprm->security;
1759
1760 if (bsec->unsafe) {
1761 force_sig_specific(SIGKILL, current);
1762 return;
1763 }
1764 if (tsec->osid == tsec->sid)
1765 return;
1766
1767 /* Close files for which the new task SID is not authorized. */
1768 flush_unauthorized_files(current->files);
1769
1770 /* Check whether the new SID can inherit signal state
1771 from the old SID. If not, clear itimers to avoid
1772 subsequent signal generation and flush and unblock
1773 signals. This must occur _after_ the task SID has
1774 been updated so that any kill done after the flush
1775 will be checked against the new SID. */
1776 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1777 PROCESS__SIGINH, NULL);
1778 if (rc) {
1779 memset(&itimer, 0, sizeof itimer);
1780 for (i = 0; i < 3; i++)
1781 do_setitimer(i, &itimer, NULL);
1782 flush_signals(current);
1783 spin_lock_irq(&current->sighand->siglock);
1784 flush_signal_handlers(current, 1);
1785 sigemptyset(&current->blocked);
1786 recalc_sigpending();
1787 spin_unlock_irq(&current->sighand->siglock);
1788 }
1789
1790 /* Check whether the new SID can inherit resource limits
1791 from the old SID. If not, reset all soft limits to
1792 the lower of the current task's hard limit and the init
1793 task's soft limit. Note that the setting of hard limits
1794 (even to lower them) can be controlled by the setrlimit
1795 check. The inclusion of the init task's soft limit into
1796 the computation is to avoid resetting soft limits higher
1797 than the default soft limit for cases where the default
1798 is lower than the hard limit, e.g. RLIMIT_CORE or
1799 RLIMIT_STACK.*/
1800 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1801 PROCESS__RLIMITINH, NULL);
1802 if (rc) {
1803 for (i = 0; i < RLIM_NLIMITS; i++) {
1804 rlim = current->signal->rlim + i;
1805 initrlim = init_task.signal->rlim+i;
1806 rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1807 }
1808 if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1809 /*
1810 * This will cause RLIMIT_CPU calculations
1811 * to be refigured.
1812 */
1813 current->it_prof_expires = jiffies_to_cputime(1);
1814 }
1815 }
1816
1817 /* Wake up the parent if it is waiting so that it can
1818 recheck wait permission to the new task SID. */
1819 wake_up_interruptible(&current->parent->signal->wait_chldexit);
1820}
1821
1822/* superblock security operations */
1823
1824static int selinux_sb_alloc_security(struct super_block *sb)
1825{
1826 return superblock_alloc_security(sb);
1827}
1828
1829static void selinux_sb_free_security(struct super_block *sb)
1830{
1831 superblock_free_security(sb);
1832}
1833
1834static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1835{
1836 if (plen > olen)
1837 return 0;
1838
1839 return !memcmp(prefix, option, plen);
1840}
1841
1842static inline int selinux_option(char *option, int len)
1843{
1844 return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1845 match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
1846 match_prefix("defcontext=", sizeof("defcontext=")-1, option, len));
1847}
1848
1849static inline void take_option(char **to, char *from, int *first, int len)
1850{
1851 if (!*first) {
1852 **to = ',';
1853 *to += 1;
1854 }
1855 else
1856 *first = 0;
1857 memcpy(*to, from, len);
1858 *to += len;
1859}
1860
1861static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1862{
1863 int fnosec, fsec, rc = 0;
1864 char *in_save, *in_curr, *in_end;
1865 char *sec_curr, *nosec_save, *nosec;
1866
1867 in_curr = orig;
1868 sec_curr = copy;
1869
1870 /* Binary mount data: just copy */
1871 if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1872 copy_page(sec_curr, in_curr);
1873 goto out;
1874 }
1875
1876 nosec = (char *)get_zeroed_page(GFP_KERNEL);
1877 if (!nosec) {
1878 rc = -ENOMEM;
1879 goto out;
1880 }
1881
1882 nosec_save = nosec;
1883 fnosec = fsec = 1;
1884 in_save = in_end = orig;
1885
1886 do {
1887 if (*in_end == ',' || *in_end == '\0') {
1888 int len = in_end - in_curr;
1889
1890 if (selinux_option(in_curr, len))
1891 take_option(&sec_curr, in_curr, &fsec, len);
1892 else
1893 take_option(&nosec, in_curr, &fnosec, len);
1894
1895 in_curr = in_end + 1;
1896 }
1897 } while (*in_end++);
1898
6931dfc9 1899 strcpy(in_save, nosec_save);
da3caa20 1900 free_page((unsigned long)nosec_save);
1da177e4
LT		 1901out:
1902 return rc;
1903}
1904
1905static int selinux_sb_kern_mount(struct super_block *sb, void *data)
1906{
1907 struct avc_audit_data ad;
1908 int rc;
1909
1910 rc = superblock_doinit(sb, data);
1911 if (rc)
1912 return rc;
1913
1914 AVC_AUDIT_DATA_INIT(&ad,FS);
1915 ad.u.fs.dentry = sb->s_root;
1916 return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
1917}
1918
726c3342 1919static int selinux_sb_statfs(struct dentry *dentry)
1da177e4
LT		 1920{
1921 struct avc_audit_data ad;
1922
1923 AVC_AUDIT_DATA_INIT(&ad,FS);
726c3342
DH		 1924 ad.u.fs.dentry = dentry->d_sb->s_root;
1925 return superblock_has_perm(current, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
1da177e4
LT		 1926}
1927
1928static int selinux_mount(char * dev_name,
1929 struct nameidata *nd,
1930 char * type,
1931 unsigned long flags,
1932 void * data)
1933{
1934 int rc;
1935
1936 rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
1937 if (rc)
1938 return rc;
1939
1940 if (flags & MS_REMOUNT)
1941 return superblock_has_perm(current, nd->mnt->mnt_sb,
1942 FILESYSTEM__REMOUNT, NULL);
1943 else
1944 return dentry_has_perm(current, nd->mnt, nd->dentry,
1945 FILE__MOUNTON);
1946}
1947
1948static int selinux_umount(struct vfsmount *mnt, int flags)
1949{
1950 int rc;
1951
1952 rc = secondary_ops->sb_umount(mnt, flags);
1953 if (rc)
1954 return rc;
1955
1956 return superblock_has_perm(current,mnt->mnt_sb,
1957 FILESYSTEM__UNMOUNT,NULL);
1958}
1959
1960/* inode security operations */
1961
1962static int selinux_inode_alloc_security(struct inode *inode)
1963{
1964 return inode_alloc_security(inode);
1965}
1966
1967static void selinux_inode_free_security(struct inode *inode)
1968{
1969 inode_free_security(inode);
1970}
1971
5e41ff9e
SS		 1972static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
1973 char **name, void **value,
1974 size_t *len)
1975{
1976 struct task_security_struct *tsec;
1977 struct inode_security_struct *dsec;
1978 struct superblock_security_struct *sbsec;
570bc1c2 1979 u32 newsid, clen;
5e41ff9e 1980 int rc;
570bc1c2 1981 char *namep = NULL, *context;
5e41ff9e
SS		 1982
1983 tsec = current->security;
1984 dsec = dir->i_security;
1985 sbsec = dir->i_sb->s_security;
5e41ff9e
SS		 1986
1987 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1988 newsid = tsec->create_sid;
1989 } else {
1990 rc = security_transition_sid(tsec->sid, dsec->sid,
1991 inode_mode_to_security_class(inode->i_mode),
1992 &newsid);
1993 if (rc) {
1994 printk(KERN_WARNING "%s: "
1995 "security_transition_sid failed, rc=%d (dev=%s "
1996 "ino=%ld)\n",
1997 __FUNCTION__,
1998 -rc, inode->i_sb->s_id, inode->i_ino);
1999 return rc;
2000 }
2001 }
2002
2003 inode_security_set_sid(inode, newsid);
2004
8aad3875 2005 if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
25a74f3b
SS		 2006 return -EOPNOTSUPP;
2007
570bc1c2
SS		 2008 if (name) {
2009 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
2010 if (!namep)
2011 return -ENOMEM;
2012 *name = namep;
2013 }
5e41ff9e 2014
570bc1c2
SS		 2015 if (value && len) {
2016 rc = security_sid_to_context(newsid, &context, &clen);
2017 if (rc) {
2018 kfree(namep);
2019 return rc;
2020 }
2021 *value = context;
2022 *len = clen;
5e41ff9e 2023 }
5e41ff9e 2024
5e41ff9e
SS		 2025 return 0;
2026}
2027
1da177e4
LT		 2028static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2029{
2030 return may_create(dir, dentry, SECCLASS_FILE);
2031}
2032
1da177e4
LT		 2033static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2034{
2035 int rc;
2036
2037 rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2038 if (rc)
2039 return rc;
2040 return may_link(dir, old_dentry, MAY_LINK);
2041}
2042
1da177e4
LT		 2043static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2044{
2045 int rc;
2046
2047 rc = secondary_ops->inode_unlink(dir, dentry);
2048 if (rc)
2049 return rc;
2050 return may_link(dir, dentry, MAY_UNLINK);
2051}
2052
2053static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2054{
2055 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2056}
2057
1da177e4
LT		 2058static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2059{
2060 return may_create(dir, dentry, SECCLASS_DIR);
2061}
2062
1da177e4
LT		 2063static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2064{
2065 return may_link(dir, dentry, MAY_RMDIR);
2066}
2067
2068static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2069{
2070 int rc;
2071
2072 rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2073 if (rc)
2074 return rc;
2075
2076 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2077}
2078
1da177e4
LT		 2079static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2080 struct inode *new_inode, struct dentry *new_dentry)
2081{
2082 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2083}
2084
1da177e4
LT		 2085static int selinux_inode_readlink(struct dentry *dentry)
2086{
2087 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2088}
2089
2090static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2091{
2092 int rc;
2093
2094 rc = secondary_ops->inode_follow_link(dentry,nameidata);
2095 if (rc)
2096 return rc;
2097 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2098}
2099
2100static int selinux_inode_permission(struct inode *inode, int mask,
2101 struct nameidata *nd)
2102{
2103 int rc;
2104
2105 rc = secondary_ops->inode_permission(inode, mask, nd);
2106 if (rc)
2107 return rc;
2108
2109 if (!mask) {
2110 /* No permission to check. Existence test. */
2111 return 0;
2112 }
2113
2114 return inode_has_perm(current, inode,
2115 file_mask_to_av(inode->i_mode, mask), NULL);
2116}
2117
2118static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2119{
2120 int rc;
2121
2122 rc = secondary_ops->inode_setattr(dentry, iattr);
2123 if (rc)
2124 return rc;
2125
2126 if (iattr->ia_valid & ATTR_FORCE)
2127 return 0;
2128
2129 if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2130 ATTR_ATIME_SET | ATTR_MTIME_SET))
2131 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2132
2133 return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2134}
2135
2136static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2137{
2138 return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2139}
2140
2141static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2142{
2143 struct task_security_struct *tsec = current->security;
2144 struct inode *inode = dentry->d_inode;
2145 struct inode_security_struct *isec = inode->i_security;
2146 struct superblock_security_struct *sbsec;
2147 struct avc_audit_data ad;
2148 u32 newsid;
2149 int rc = 0;
2150
2151 if (strcmp(name, XATTR_NAME_SELINUX)) {
2152 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2153 sizeof XATTR_SECURITY_PREFIX - 1) &&
2154 !capable(CAP_SYS_ADMIN)) {
2155 /* A different attribute in the security namespace.
2156 Restrict to administrator. */
2157 return -EPERM;
2158 }
2159
2160 /* Not an attribute we recognize, so just check the
2161 ordinary setattr permission. */
2162 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2163 }
2164
2165 sbsec = inode->i_sb->s_security;
2166 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2167 return -EOPNOTSUPP;
2168
2169 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2170 return -EPERM;
2171
2172 AVC_AUDIT_DATA_INIT(&ad,FS);
2173 ad.u.fs.dentry = dentry;
2174
2175 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2176 FILE__RELABELFROM, &ad);
2177 if (rc)
2178 return rc;
2179
2180 rc = security_context_to_sid(value, size, &newsid);
2181 if (rc)
2182 return rc;
2183
2184 rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2185 FILE__RELABELTO, &ad);
2186 if (rc)
2187 return rc;
2188
2189 rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2190 isec->sclass);
2191 if (rc)
2192 return rc;
2193
2194 return avc_has_perm(newsid,
2195 sbsec->sid,
2196 SECCLASS_FILESYSTEM,
2197 FILESYSTEM__ASSOCIATE,
2198 &ad);
2199}
2200
2201static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2202 void *value, size_t size, int flags)
2203{
2204 struct inode *inode = dentry->d_inode;
2205 struct inode_security_struct *isec = inode->i_security;
2206 u32 newsid;
2207 int rc;
2208
2209 if (strcmp(name, XATTR_NAME_SELINUX)) {
2210 /* Not an attribute we recognize, so nothing to do. */
2211 return;
2212 }
2213
2214 rc = security_context_to_sid(value, size, &newsid);
2215 if (rc) {
2216 printk(KERN_WARNING "%s: unable to obtain SID for context "
2217 "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2218 return;
2219 }
2220
2221 isec->sid = newsid;
2222 return;
2223}
2224
2225static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2226{
1da177e4
LT		 2227 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2228}
2229
2230static int selinux_inode_listxattr (struct dentry *dentry)
2231{
2232 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2233}
2234
2235static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2236{
2237 if (strcmp(name, XATTR_NAME_SELINUX)) {
2238 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2239 sizeof XATTR_SECURITY_PREFIX - 1) &&
2240 !capable(CAP_SYS_ADMIN)) {
2241 /* A different attribute in the security namespace.
2242 Restrict to administrator. */
2243 return -EPERM;
2244 }
2245
2246 /* Not an attribute we recognize, so just check the
2247 ordinary setattr permission. Might want a separate
2248 permission for removexattr. */
2249 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2250 }
2251
2252 /* No one is allowed to remove a SELinux security label.
2253 You can change the label, but all data must be labeled. */
2254 return -EACCES;
2255}
2256
8c8570fb
DK		 2257static const char *selinux_inode_xattr_getsuffix(void)
2258{
2259 return XATTR_SELINUX_SUFFIX;
2260}
2261
d381d8a9
JM		 2262/*
2263 * Copy the in-core inode security context value to the user. If the
2264 * getxattr() prior to this succeeded, check to see if we need to
2265 * canonicalize the value to be finally returned to the user.
2266 *
2267 * Permission check is handled by selinux_inode_getxattr hook.
2268 */
7306a0b9 2269static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
1da177e4
LT		 2270{
2271 struct inode_security_struct *isec = inode->i_security;
d381d8a9 2272
8c8570fb
DK		 2273 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2274 return -EOPNOTSUPP;
d381d8a9 2275
8c8570fb 2276 return selinux_getsecurity(isec->sid, buffer, size);
1da177e4
LT		 2277}
2278
2279static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2280 const void *value, size_t size, int flags)
2281{
2282 struct inode_security_struct *isec = inode->i_security;
2283 u32 newsid;
2284 int rc;
2285
2286 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2287 return -EOPNOTSUPP;
2288
2289 if (!value || !size)
2290 return -EACCES;
2291
2292 rc = security_context_to_sid((void*)value, size, &newsid);
2293 if (rc)
2294 return rc;
2295
2296 isec->sid = newsid;
2297 return 0;
2298}
2299
2300static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2301{
2302 const int len = sizeof(XATTR_NAME_SELINUX);
2303 if (buffer && len <= buffer_size)
2304 memcpy(buffer, XATTR_NAME_SELINUX, len);
2305 return len;
2306}
2307
2308/* file security operations */
2309
2310static int selinux_file_permission(struct file *file, int mask)
2311{
2312 struct inode *inode = file->f_dentry->d_inode;
2313
2314 if (!mask) {
2315 /* No permission to check. Existence test. */
2316 return 0;
2317 }
2318
2319 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2320 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2321 mask |= MAY_APPEND;
2322
2323 return file_has_perm(current, file,
2324 file_mask_to_av(inode->i_mode, mask));
2325}
2326
2327static int selinux_file_alloc_security(struct file *file)
2328{
2329 return file_alloc_security(file);
2330}
2331
2332static void selinux_file_free_security(struct file *file)
2333{
2334 file_free_security(file);
2335}
2336
2337static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2338 unsigned long arg)
2339{
2340 int error = 0;
2341
2342 switch (cmd) {
2343 case FIONREAD:
2344 /* fall through */
2345 case FIBMAP:
2346 /* fall through */
2347 case FIGETBSZ:
2348 /* fall through */
2349 case EXT2_IOC_GETFLAGS:
2350 /* fall through */
2351 case EXT2_IOC_GETVERSION:
2352 error = file_has_perm(current, file, FILE__GETATTR);
2353 break;
2354
2355 case EXT2_IOC_SETFLAGS:
2356 /* fall through */
2357 case EXT2_IOC_SETVERSION:
2358 error = file_has_perm(current, file, FILE__SETATTR);
2359 break;
2360
2361 /* sys_ioctl() checks */
2362 case FIONBIO:
2363 /* fall through */
2364 case FIOASYNC:
2365 error = file_has_perm(current, file, 0);
2366 break;
2367
2368 case KDSKBENT:
2369 case KDSKBSENT:
2370 error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2371 break;
2372
2373 /* default case assumes that the command will go
2374 * to the file's ioctl() function.
2375 */
2376 default:
2377 error = file_has_perm(current, file, FILE__IOCTL);
2378
2379 }
2380 return error;
2381}
2382
2383static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2384{
2385#ifndef CONFIG_PPC32
2386 if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2387 /*
2388 * We are making executable an anonymous mapping or a
2389 * private file mapping that will also be writable.
2390 * This has an additional check.
2391 */
2392 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2393 if (rc)
2394 return rc;
2395 }
2396#endif
2397
2398 if (file) {
2399 /* read access is always possible with a mapping */
2400 u32 av = FILE__READ;
2401
2402 /* write access only matters if the mapping is shared */
2403 if (shared && (prot & PROT_WRITE))
2404 av |= FILE__WRITE;
2405
2406 if (prot & PROT_EXEC)
2407 av |= FILE__EXECUTE;
2408
2409 return file_has_perm(current, file, av);
2410 }
2411 return 0;
2412}
2413
2414static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2415 unsigned long prot, unsigned long flags)
2416{
2417 int rc;
2418
2419 rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2420 if (rc)
2421 return rc;
2422
2423 if (selinux_checkreqprot)
2424 prot = reqprot;
2425
2426 return file_map_prot_check(file, prot,
2427 (flags & MAP_TYPE) == MAP_SHARED);
2428}
2429
2430static int selinux_file_mprotect(struct vm_area_struct *vma,
2431 unsigned long reqprot,
2432 unsigned long prot)
2433{
2434 int rc;
2435
2436 rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2437 if (rc)
2438 return rc;
2439
2440 if (selinux_checkreqprot)
2441 prot = reqprot;
2442
2443#ifndef CONFIG_PPC32
db4c9641
SS		 2444 if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
2445 rc = 0;
2446 if (vma->vm_start >= vma->vm_mm->start_brk &&
2447 vma->vm_end <= vma->vm_mm->brk) {
2448 rc = task_has_perm(current, current,
2449 PROCESS__EXECHEAP);
2450 } else if (!vma->vm_file &&
2451 vma->vm_start <= vma->vm_mm->start_stack &&
2452 vma->vm_end >= vma->vm_mm->start_stack) {
2453 rc = task_has_perm(current, current, PROCESS__EXECSTACK);
2454 } else if (vma->vm_file && vma->anon_vma) {
2455 /*
2456 * We are making executable a file mapping that has
2457 * had some COW done. Since pages might have been
2458 * written, check ability to execute the possibly
2459 * modified content. This typically should only
2460 * occur for text relocations.
2461 */
2462 rc = file_has_perm(current, vma->vm_file,
2463 FILE__EXECMOD);
2464 }