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[PATCH] cleanup next_tid()
[deliverable/linux.git] / security / selinux / hooks.c
CommitLineData
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, <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 Red Hat, Inc., James Morris <jmorris@redhat.com>
13 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
14 * <dgoeddel@trustedcs.com>
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
21#include <linux/config.h>
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/ptrace.h>
26#include <linux/errno.h>
27#include <linux/sched.h>
28#include <linux/security.h>
29#include <linux/xattr.h>
30#include <linux/capability.h>
31#include <linux/unistd.h>
32#include <linux/mm.h>
33#include <linux/mman.h>
34#include <linux/slab.h>
35#include <linux/pagemap.h>
36#include <linux/swap.h>
37#include <linux/smp_lock.h>
38#include <linux/spinlock.h>
39#include <linux/syscalls.h>
40#include <linux/file.h>
41#include <linux/namei.h>
42#include <linux/mount.h>
43#include <linux/ext2_fs.h>
44#include <linux/proc_fs.h>
45#include <linux/kd.h>
46#include <linux/netfilter_ipv4.h>
47#include <linux/netfilter_ipv6.h>
48#include <linux/tty.h>
49#include <net/icmp.h>
50#include <net/ip.h> /* for sysctl_local_port_range[] */
51#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
52#include <asm/uaccess.h>
53#include <asm/semaphore.h>
54#include <asm/ioctls.h>
55#include <linux/bitops.h>
56#include <linux/interrupt.h>
57#include <linux/netdevice.h> /* for network interface checks */
58#include <linux/netlink.h>
59#include <linux/tcp.h>
60#include <linux/udp.h>
61#include <linux/quota.h>
62#include <linux/un.h> /* for Unix socket types */
63#include <net/af_unix.h> /* for Unix socket types */
64#include <linux/parser.h>
65#include <linux/nfs_mount.h>
66#include <net/ipv6.h>
67#include <linux/hugetlb.h>
68#include <linux/personality.h>
69#include <linux/sysctl.h>
70#include <linux/audit.h>
6931dfc9 71#include <linux/string.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
1535 /* Reset create SID on execve. */
1536 tsec->create_sid = 0;
1537
1538 if (tsec->exec_sid) {
1539 newsid = tsec->exec_sid;
1540 /* Reset exec SID on execve. */
1541 tsec->exec_sid = 0;
1542 } else {
1543 /* Check for a default transition on this program. */
1544 rc = security_transition_sid(tsec->sid, isec->sid,
1545 SECCLASS_PROCESS, &newsid);
1546 if (rc)
1547 return rc;
1548 }
1549
1550 AVC_AUDIT_DATA_INIT(&ad, FS);
1551 ad.u.fs.mnt = bprm->file->f_vfsmnt;
1552 ad.u.fs.dentry = bprm->file->f_dentry;
1553
1554 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
1555 newsid = tsec->sid;
1556
1557 if (tsec->sid == newsid) {
1558 rc = avc_has_perm(tsec->sid, isec->sid,
1559 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1560 if (rc)
1561 return rc;
1562 } else {
1563 /* Check permissions for the transition. */
1564 rc = avc_has_perm(tsec->sid, newsid,
1565 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1566 if (rc)
1567 return rc;
1568
1569 rc = avc_has_perm(newsid, isec->sid,
1570 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1571 if (rc)
1572 return rc;
1573
1574 /* Clear any possibly unsafe personality bits on exec: */
1575 current->personality &= ~PER_CLEAR_ON_SETID;
1576
1577 /* Set the security field to the new SID. */
1578 bsec->sid = newsid;
1579 }
1580
1581 bsec->set = 1;
1582 return 0;
1583}
1584
1585static int selinux_bprm_check_security (struct linux_binprm *bprm)
1586{
1587 return secondary_ops->bprm_check_security(bprm);
1588}
1589
1590
1591static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1592{
1593 struct task_security_struct *tsec = current->security;
1594 int atsecure = 0;
1595
1596 if (tsec->osid != tsec->sid) {
1597 /* Enable secure mode for SIDs transitions unless
1598 the noatsecure permission is granted between
1599 the two SIDs, i.e. ahp returns 0. */
1600 atsecure = avc_has_perm(tsec->osid, tsec->sid,
1601 SECCLASS_PROCESS,
1602 PROCESS__NOATSECURE, NULL);
1603 }
1604
1605 return (atsecure || secondary_ops->bprm_secureexec(bprm));
1606}
1607
1608static void selinux_bprm_free_security(struct linux_binprm *bprm)
1609{
9a5f04bf 1610 kfree(bprm->security);
1da177e4 1611 bprm->security = NULL;
1da177e4
LT		 1612}
1613
1614extern struct vfsmount *selinuxfs_mount;
1615extern struct dentry *selinux_null;
1616
1617/* Derived from fs/exec.c:flush_old_files. */
1618static inline void flush_unauthorized_files(struct files_struct * files)
1619{
1620 struct avc_audit_data ad;
1621 struct file *file, *devnull = NULL;
1622 struct tty_struct *tty = current->signal->tty;
badf1662 1623 struct fdtable *fdt;
1da177e4
LT		 1624 long j = -1;
1625
1626 if (tty) {
1627 file_list_lock();
2f512016 1628 file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
1da177e4
LT		 1629 if (file) {
1630 /* Revalidate access to controlling tty.
1631 Use inode_has_perm on the tty inode directly rather
1632 than using file_has_perm, as this particular open
1633 file may belong to another process and we are only
1634 interested in the inode-based check here. */
1635 struct inode *inode = file->f_dentry->d_inode;
1636 if (inode_has_perm(current, inode,
1637 FILE__READ | FILE__WRITE, NULL)) {
1638 /* Reset controlling tty. */
1639 current->signal->tty = NULL;
1640 current->signal->tty_old_pgrp = 0;
1641 }
1642 }
1643 file_list_unlock();
1644 }
1645
1646 /* Revalidate access to inherited open files. */
1647
1648 AVC_AUDIT_DATA_INIT(&ad,FS);
1649
1650 spin_lock(&files->file_lock);
1651 for (;;) {
1652 unsigned long set, i;
1653 int fd;
1654
1655 j++;
1656 i = j * __NFDBITS;
badf1662
DS		 1657 fdt = files_fdtable(files);
1658 if (i >= fdt->max_fds || i >= fdt->max_fdset)
1da177e4 1659 break;
badf1662 1660 set = fdt->open_fds->fds_bits[j];
1da177e4
LT		 1661 if (!set)
1662 continue;
1663 spin_unlock(&files->file_lock);
1664 for ( ; set ; i++,set >>= 1) {
1665 if (set & 1) {
1666 file = fget(i);
1667 if (!file)
1668 continue;
1669 if (file_has_perm(current,
1670 file,
1671 file_to_av(file))) {
1672 sys_close(i);
1673 fd = get_unused_fd();
1674 if (fd != i) {
1675 if (fd >= 0)
1676 put_unused_fd(fd);
1677 fput(file);
1678 continue;
1679 }
1680 if (devnull) {
095975da 1681 get_file(devnull);
1da177e4
LT		 1682 } else {
1683 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1684 if (!devnull) {
1685 put_unused_fd(fd);
1686 fput(file);
1687 continue;
1688 }
1689 }
1690 fd_install(fd, devnull);
1691 }
1692 fput(file);
1693 }
1694 }
1695 spin_lock(&files->file_lock);
1696
1697 }
1698 spin_unlock(&files->file_lock);
1699}
1700
1701static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1702{
1703 struct task_security_struct *tsec;
1704 struct bprm_security_struct *bsec;
1705 u32 sid;
1706 int rc;
1707
1708 secondary_ops->bprm_apply_creds(bprm, unsafe);
1709
1710 tsec = current->security;
1711
1712 bsec = bprm->security;
1713 sid = bsec->sid;
1714
1715 tsec->osid = tsec->sid;
1716 bsec->unsafe = 0;
1717 if (tsec->sid != sid) {
1718 /* Check for shared state. If not ok, leave SID
1719 unchanged and kill. */
1720 if (unsafe & LSM_UNSAFE_SHARE) {
1721 rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1722 PROCESS__SHARE, NULL);
1723 if (rc) {
1724 bsec->unsafe = 1;
1725 return;
1726 }
1727 }
1728
1729 /* Check for ptracing, and update the task SID if ok.
1730 Otherwise, leave SID unchanged and kill. */
1731 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1732 rc = avc_has_perm(tsec->ptrace_sid, sid,
1733 SECCLASS_PROCESS, PROCESS__PTRACE,
1734 NULL);
1735 if (rc) {
1736 bsec->unsafe = 1;
1737 return;
1738 }
1739 }
1740 tsec->sid = sid;
1741 }
1742}
1743
1744/*
1745 * called after apply_creds without the task lock held
1746 */
1747static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1748{
1749 struct task_security_struct *tsec;
1750 struct rlimit *rlim, *initrlim;
1751 struct itimerval itimer;
1752 struct bprm_security_struct *bsec;
1753 int rc, i;
1754
1755 tsec = current->security;
1756 bsec = bprm->security;
1757
1758 if (bsec->unsafe) {
1759 force_sig_specific(SIGKILL, current);
1760 return;
1761 }
1762 if (tsec->osid == tsec->sid)
1763 return;
1764
1765 /* Close files for which the new task SID is not authorized. */
1766 flush_unauthorized_files(current->files);
1767
1768 /* Check whether the new SID can inherit signal state
1769 from the old SID. If not, clear itimers to avoid
1770 subsequent signal generation and flush and unblock
1771 signals. This must occur _after_ the task SID has
1772 been updated so that any kill done after the flush
1773 will be checked against the new SID. */
1774 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1775 PROCESS__SIGINH, NULL);
1776 if (rc) {
1777 memset(&itimer, 0, sizeof itimer);
1778 for (i = 0; i < 3; i++)
1779 do_setitimer(i, &itimer, NULL);
1780 flush_signals(current);
1781 spin_lock_irq(&current->sighand->siglock);
1782 flush_signal_handlers(current, 1);
1783 sigemptyset(&current->blocked);
1784 recalc_sigpending();
1785 spin_unlock_irq(&current->sighand->siglock);
1786 }
1787
1788 /* Check whether the new SID can inherit resource limits
1789 from the old SID. If not, reset all soft limits to
1790 the lower of the current task's hard limit and the init
1791 task's soft limit. Note that the setting of hard limits
1792 (even to lower them) can be controlled by the setrlimit
1793 check. The inclusion of the init task's soft limit into
1794 the computation is to avoid resetting soft limits higher
1795 than the default soft limit for cases where the default
1796 is lower than the hard limit, e.g. RLIMIT_CORE or
1797 RLIMIT_STACK.*/
1798 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1799 PROCESS__RLIMITINH, NULL);
1800 if (rc) {
1801 for (i = 0; i < RLIM_NLIMITS; i++) {
1802 rlim = current->signal->rlim + i;
1803 initrlim = init_task.signal->rlim+i;
1804 rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1805 }
1806 if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1807 /*
1808 * This will cause RLIMIT_CPU calculations
1809 * to be refigured.
1810 */
1811 current->it_prof_expires = jiffies_to_cputime(1);
1812 }
1813 }
1814
1815 /* Wake up the parent if it is waiting so that it can
1816 recheck wait permission to the new task SID. */
1817 wake_up_interruptible(&current->parent->signal->wait_chldexit);
1818}
1819
1820/* superblock security operations */
1821
1822static int selinux_sb_alloc_security(struct super_block *sb)
1823{
1824 return superblock_alloc_security(sb);
1825}
1826
1827static void selinux_sb_free_security(struct super_block *sb)
1828{
1829 superblock_free_security(sb);
1830}
1831
1832static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1833{
1834 if (plen > olen)
1835 return 0;
1836
1837 return !memcmp(prefix, option, plen);
1838}
1839
1840static inline int selinux_option(char *option, int len)
1841{
1842 return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1843 match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
1844 match_prefix("defcontext=", sizeof("defcontext=")-1, option, len));
1845}
1846
1847static inline void take_option(char **to, char *from, int *first, int len)
1848{
1849 if (!*first) {
1850 **to = ',';
1851 *to += 1;
1852 }
1853 else
1854 *first = 0;
1855 memcpy(*to, from, len);
1856 *to += len;
1857}
1858
1859static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1860{
1861 int fnosec, fsec, rc = 0;
1862 char *in_save, *in_curr, *in_end;
1863 char *sec_curr, *nosec_save, *nosec;
1864
1865 in_curr = orig;
1866 sec_curr = copy;
1867
1868 /* Binary mount data: just copy */
1869 if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1870 copy_page(sec_curr, in_curr);
1871 goto out;
1872 }
1873
1874 nosec = (char *)get_zeroed_page(GFP_KERNEL);
1875 if (!nosec) {
1876 rc = -ENOMEM;
1877 goto out;
1878 }
1879
1880 nosec_save = nosec;
1881 fnosec = fsec = 1;
1882 in_save = in_end = orig;
1883
1884 do {
1885 if (*in_end == ',' || *in_end == '\0') {
1886 int len = in_end - in_curr;
1887
1888 if (selinux_option(in_curr, len))
1889 take_option(&sec_curr, in_curr, &fsec, len);
1890 else
1891 take_option(&nosec, in_curr, &fnosec, len);
1892
1893 in_curr = in_end + 1;
1894 }
1895 } while (*in_end++);
1896
6931dfc9 1897 strcpy(in_save, nosec_save);
da3caa20 1898 free_page((unsigned long)nosec_save);
1da177e4
LT		 1899out:
1900 return rc;
1901}
1902
1903static int selinux_sb_kern_mount(struct super_block *sb, void *data)
1904{
1905 struct avc_audit_data ad;
1906 int rc;
1907
1908 rc = superblock_doinit(sb, data);
1909 if (rc)
1910 return rc;
1911
1912 AVC_AUDIT_DATA_INIT(&ad,FS);
1913 ad.u.fs.dentry = sb->s_root;
1914 return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
1915}
1916
726c3342 1917static int selinux_sb_statfs(struct dentry *dentry)
1da177e4
LT		 1918{
1919 struct avc_audit_data ad;
1920
1921 AVC_AUDIT_DATA_INIT(&ad,FS);
726c3342
DH		 1922 ad.u.fs.dentry = dentry->d_sb->s_root;
1923 return superblock_has_perm(current, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
1da177e4
LT		 1924}
1925
1926static int selinux_mount(char * dev_name,
1927 struct nameidata *nd,
1928 char * type,
1929 unsigned long flags,
1930 void * data)
1931{
1932 int rc;
1933
1934 rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
1935 if (rc)
1936 return rc;
1937
1938 if (flags & MS_REMOUNT)
1939 return superblock_has_perm(current, nd->mnt->mnt_sb,
1940 FILESYSTEM__REMOUNT, NULL);
1941 else
1942 return dentry_has_perm(current, nd->mnt, nd->dentry,
1943 FILE__MOUNTON);
1944}
1945
1946static int selinux_umount(struct vfsmount *mnt, int flags)
1947{
1948 int rc;
1949
1950 rc = secondary_ops->sb_umount(mnt, flags);
1951 if (rc)
1952 return rc;
1953
1954 return superblock_has_perm(current,mnt->mnt_sb,
1955 FILESYSTEM__UNMOUNT,NULL);
1956}
1957
1958/* inode security operations */
1959
1960static int selinux_inode_alloc_security(struct inode *inode)
1961{
1962 return inode_alloc_security(inode);
1963}
1964
1965static void selinux_inode_free_security(struct inode *inode)
1966{
1967 inode_free_security(inode);
1968}
1969
5e41ff9e
SS		 1970static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
1971 char **name, void **value,
1972 size_t *len)
1973{
1974 struct task_security_struct *tsec;
1975 struct inode_security_struct *dsec;
1976 struct superblock_security_struct *sbsec;
570bc1c2 1977 u32 newsid, clen;
5e41ff9e 1978 int rc;
570bc1c2 1979 char *namep = NULL, *context;
5e41ff9e
SS		 1980
1981 tsec = current->security;
1982 dsec = dir->i_security;
1983 sbsec = dir->i_sb->s_security;
5e41ff9e
SS		 1984
1985 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1986 newsid = tsec->create_sid;
1987 } else {
1988 rc = security_transition_sid(tsec->sid, dsec->sid,
1989 inode_mode_to_security_class(inode->i_mode),
1990 &newsid);
1991 if (rc) {
1992 printk(KERN_WARNING "%s: "
1993 "security_transition_sid failed, rc=%d (dev=%s "
1994 "ino=%ld)\n",
1995 __FUNCTION__,
1996 -rc, inode->i_sb->s_id, inode->i_ino);
1997 return rc;
1998 }
1999 }
2000
2001 inode_security_set_sid(inode, newsid);
2002
8aad3875 2003 if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
25a74f3b
SS		 2004 return -EOPNOTSUPP;
2005
570bc1c2
SS		 2006 if (name) {
2007 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
2008 if (!namep)
2009 return -ENOMEM;
2010 *name = namep;
2011 }
5e41ff9e 2012
570bc1c2
SS		 2013 if (value && len) {
2014 rc = security_sid_to_context(newsid, &context, &clen);
2015 if (rc) {
2016 kfree(namep);
2017 return rc;
2018 }
2019 *value = context;
2020 *len = clen;
5e41ff9e 2021 }
5e41ff9e 2022
5e41ff9e
SS		 2023 return 0;
2024}
2025
1da177e4
LT		 2026static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2027{
2028 return may_create(dir, dentry, SECCLASS_FILE);
2029}
2030
1da177e4
LT		 2031static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2032{
2033 int rc;
2034
2035 rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2036 if (rc)
2037 return rc;
2038 return may_link(dir, old_dentry, MAY_LINK);
2039}
2040
1da177e4
LT		 2041static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2042{
2043 int rc;
2044
2045 rc = secondary_ops->inode_unlink(dir, dentry);
2046 if (rc)
2047 return rc;
2048 return may_link(dir, dentry, MAY_UNLINK);
2049}
2050
2051static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2052{
2053 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2054}
2055
1da177e4
LT		 2056static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2057{
2058 return may_create(dir, dentry, SECCLASS_DIR);
2059}
2060
1da177e4
LT		 2061static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2062{
2063 return may_link(dir, dentry, MAY_RMDIR);
2064}
2065
2066static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2067{
2068 int rc;
2069
2070 rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2071 if (rc)
2072 return rc;
2073
2074 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2075}
2076
1da177e4
LT		 2077static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2078 struct inode *new_inode, struct dentry *new_dentry)
2079{
2080 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2081}
2082
1da177e4
LT		 2083static int selinux_inode_readlink(struct dentry *dentry)
2084{
2085 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2086}
2087
2088static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2089{
2090 int rc;
2091
2092 rc = secondary_ops->inode_follow_link(dentry,nameidata);
2093 if (rc)
2094 return rc;
2095 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2096}
2097
2098static int selinux_inode_permission(struct inode *inode, int mask,
2099 struct nameidata *nd)
2100{
2101 int rc;
2102
2103 rc = secondary_ops->inode_permission(inode, mask, nd);
2104 if (rc)
2105 return rc;
2106
2107 if (!mask) {
2108 /* No permission to check. Existence test. */
2109 return 0;
2110 }
2111
2112 return inode_has_perm(current, inode,
2113 file_mask_to_av(inode->i_mode, mask), NULL);
2114}
2115
2116static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2117{
2118 int rc;
2119
2120 rc = secondary_ops->inode_setattr(dentry, iattr);
2121 if (rc)
2122 return rc;
2123
2124 if (iattr->ia_valid & ATTR_FORCE)
2125 return 0;
2126
2127 if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2128 ATTR_ATIME_SET | ATTR_MTIME_SET))
2129 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2130
2131 return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2132}
2133
2134static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2135{
2136 return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2137}
2138
2139static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2140{
2141 struct task_security_struct *tsec = current->security;
2142 struct inode *inode = dentry->d_inode;
2143 struct inode_security_struct *isec = inode->i_security;
2144 struct superblock_security_struct *sbsec;
2145 struct avc_audit_data ad;
2146 u32 newsid;
2147 int rc = 0;
2148
2149 if (strcmp(name, XATTR_NAME_SELINUX)) {
2150 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2151 sizeof XATTR_SECURITY_PREFIX - 1) &&
2152 !capable(CAP_SYS_ADMIN)) {
2153 /* A different attribute in the security namespace.
2154 Restrict to administrator. */
2155 return -EPERM;
2156 }
2157
2158 /* Not an attribute we recognize, so just check the
2159 ordinary setattr permission. */
2160 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2161 }
2162
2163 sbsec = inode->i_sb->s_security;
2164 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2165 return -EOPNOTSUPP;
2166
2167 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2168 return -EPERM;
2169
2170 AVC_AUDIT_DATA_INIT(&ad,FS);
2171 ad.u.fs.dentry = dentry;
2172
2173 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2174 FILE__RELABELFROM, &ad);
2175 if (rc)
2176 return rc;
2177
2178 rc = security_context_to_sid(value, size, &newsid);
2179 if (rc)
2180 return rc;
2181
2182 rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2183 FILE__RELABELTO, &ad);
2184 if (rc)
2185 return rc;
2186
2187 rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2188 isec->sclass);
2189 if (rc)
2190 return rc;
2191
2192 return avc_has_perm(newsid,
2193 sbsec->sid,
2194 SECCLASS_FILESYSTEM,
2195 FILESYSTEM__ASSOCIATE,
2196 &ad);
2197}
2198
2199static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2200 void *value, size_t size, int flags)
2201{
2202 struct inode *inode = dentry->d_inode;
2203 struct inode_security_struct *isec = inode->i_security;
2204 u32 newsid;
2205 int rc;
2206
2207 if (strcmp(name, XATTR_NAME_SELINUX)) {
2208 /* Not an attribute we recognize, so nothing to do. */
2209 return;
2210 }
2211
2212 rc = security_context_to_sid(value, size, &newsid);
2213 if (rc) {
2214 printk(KERN_WARNING "%s: unable to obtain SID for context "
2215 "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2216 return;
2217 }
2218
2219 isec->sid = newsid;
2220 return;
2221}
2222
2223static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2224{
1da177e4
LT		 2225 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2226}
2227
2228static int selinux_inode_listxattr (struct dentry *dentry)
2229{
2230 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2231}
2232
2233static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2234{
2235 if (strcmp(name, XATTR_NAME_SELINUX)) {
2236 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2237 sizeof XATTR_SECURITY_PREFIX - 1) &&
2238 !capable(CAP_SYS_ADMIN)) {
2239 /* A different attribute in the security namespace.
2240 Restrict to administrator. */
2241 return -EPERM;
2242 }
2243
2244 /* Not an attribute we recognize, so just check the
2245 ordinary setattr permission. Might want a separate
2246 permission for removexattr. */
2247 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2248 }
2249
2250 /* No one is allowed to remove a SELinux security label.
2251 You can change the label, but all data must be labeled. */
2252 return -EACCES;
2253}
2254
8c8570fb
DK		 2255static const char *selinux_inode_xattr_getsuffix(void)
2256{
2257 return XATTR_SELINUX_SUFFIX;
2258}
2259
d381d8a9
JM		 2260/*
2261 * Copy the in-core inode security context value to the user. If the
2262 * getxattr() prior to this succeeded, check to see if we need to
2263 * canonicalize the value to be finally returned to the user.
2264 *
2265 * Permission check is handled by selinux_inode_getxattr hook.
2266 */
7306a0b9 2267static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
1da177e4
LT		 2268{
2269 struct inode_security_struct *isec = inode->i_security;
d381d8a9 2270
8c8570fb
DK		 2271 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2272 return -EOPNOTSUPP;
d381d8a9 2273
8c8570fb 2274 return selinux_getsecurity(isec->sid, buffer, size);
1da177e4
LT		 2275}
2276
2277static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2278 const void *value, size_t size, int flags)
2279{
2280 struct inode_security_struct *isec = inode->i_security;
2281 u32 newsid;
2282 int rc;
2283
2284 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2285 return -EOPNOTSUPP;
2286
2287 if (!value || !size)
2288 return -EACCES;
2289
2290 rc = security_context_to_sid((void*)value, size, &newsid);
2291 if (rc)
2292 return rc;
2293
2294 isec->sid = newsid;
2295 return 0;
2296}
2297
2298static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2299{
2300 const int len = sizeof(XATTR_NAME_SELINUX);
2301 if (buffer && len <= buffer_size)
2302 memcpy(buffer, XATTR_NAME_SELINUX, len);
2303 return len;
2304}
2305
2306/* file security operations */
2307
2308static int selinux_file_permission(struct file *file, int mask)
2309{
2310 struct inode *inode = file->f_dentry->d_inode;
2311
2312 if (!mask) {
2313 /* No permission to check. Existence test. */
2314 return 0;
2315 }
2316
2317 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2318 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2319 mask |= MAY_APPEND;
2320
2321 return file_has_perm(current, file,
2322 file_mask_to_av(inode->i_mode, mask));
2323}
2324
2325static int selinux_file_alloc_security(struct file *file)
2326{
2327 return file_alloc_security(file);
2328}
2329
2330static void selinux_file_free_security(struct file *file)
2331{
2332 file_free_security(file);
2333}
2334
2335static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2336 unsigned long arg)
2337{
2338 int error = 0;
2339
2340 switch (cmd) {
2341 case FIONREAD:
2342 /* fall through */
2343 case FIBMAP:
2344 /* fall through */
2345 case FIGETBSZ:
2346 /* fall through */
2347 case EXT2_IOC_GETFLAGS:
2348 /* fall through */
2349 case EXT2_IOC_GETVERSION:
2350 error = file_has_perm(current, file, FILE__GETATTR);
2351 break;
2352
2353 case EXT2_IOC_SETFLAGS:
2354 /* fall through */
2355 case EXT2_IOC_SETVERSION:
2356 error = file_has_perm(current, file, FILE__SETATTR);
2357 break;
2358
2359 /* sys_ioctl() checks */
2360 case FIONBIO:
2361 /* fall through */
2362 case FIOASYNC:
2363 error = file_has_perm(current, file, 0);
2364 break;
2365
2366 case KDSKBENT:
2367 case KDSKBSENT:
2368 error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2369 break;
2370
2371 /* default case assumes that the command will go
2372 * to the file's ioctl() function.
2373 */
2374 default:
2375 error = file_has_perm(current, file, FILE__IOCTL);
2376
2377 }
2378 return error;
2379}
2380
2381static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2382{
2383#ifndef CONFIG_PPC32
2384 if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2385 /*
2386 * We are making executable an anonymous mapping or a
2387 * private file mapping that will also be writable.
2388 * This has an additional check.
2389 */
2390 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2391 if (rc)
2392 return rc;
2393 }
2394#endif
2395
2396 if (file) {
2397 /* read access is always possible with a mapping */
2398 u32 av = FILE__READ;
2399
2400 /* write access only matters if the mapping is shared */
2401 if (shared && (prot & PROT_WRITE))
2402 av |= FILE__WRITE;
2403
2404 if (prot & PROT_EXEC)
2405 av |= FILE__EXECUTE;
2406
2407 return file_has_perm(current, file, av);
2408 }
2409 return 0;
2410}
2411
2412static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2413 unsigned long prot, unsigned long flags)
2414{
2415 int rc;
2416
2417 rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2418 if (rc)
2419 return rc;
2420
2421 if (selinux_checkreqprot)
2422 prot = reqprot;
2423
2424 return file_map_prot_check(file, prot,
2425 (flags & MAP_TYPE) == MAP_SHARED);
2426}
2427
2428static int selinux_file_mprotect(struct vm_area_struct *vma,
2429 unsigned long reqprot,
2430 unsigned long prot)
2431{
2432 int rc;
2433
2434 rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2435 if (rc)
2436 return rc;
2437
2438 if (selinux_checkreqprot)
2439 prot = reqprot;
2440
2441#ifndef CONFIG_PPC32
db4c9641
SS		 2442 if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
2443 rc = 0;
2444 if (vma->vm_start >= vma->vm_mm->start_brk &&
2445 vma->vm_end <= vma->vm_mm->brk) {
2446 rc = task_has_perm(current, current,
2447 PROCESS__EXECHEAP);
2448 } else if (!vma->vm_file &&
2449 vma->vm_start <= vma->vm_mm->start_stack &&
2450 vma->vm_end >= vma->vm_mm->start_stack) {
2451 rc = task_has_perm(current, current, PROCESS__EXECSTACK);
2452 } else if (vma->vm_file && vma->anon_vma) {
2453 /*
2454 * We are making executable a file mapping that has
2455 * had some COW done. Since pages might have been
2456 * written, check ability to execute the possibly
2457 * modified content. This typically should only
2458 * occur for text relocations.
2459 */
2460 rc = file_has_perm(current, vma->vm_file,
2461 FILE__EXECMOD);
2462 }