Commit | Line | Data |
---|---|---|
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" | |
76 | ||
77 | #define XATTR_SELINUX_SUFFIX "selinux" | |
78 | #define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX | |
79 | ||
80 | extern unsigned int policydb_loaded_version; | |
81 | extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm); | |
82 | ||
83 | #ifdef CONFIG_SECURITY_SELINUX_DEVELOP | |
84 | int selinux_enforcing = 0; | |
85 | ||
86 | static int __init enforcing_setup(char *str) | |
87 | { | |
88 | selinux_enforcing = simple_strtol(str,NULL,0); | |
89 | return 1; | |
90 | } | |
91 | __setup("enforcing=", enforcing_setup); | |
92 | #endif | |
93 | ||
94 | #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM | |
95 | int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE; | |
96 | ||
97 | static int __init selinux_enabled_setup(char *str) | |
98 | { | |
99 | selinux_enabled = simple_strtol(str, NULL, 0); | |
100 | return 1; | |
101 | } | |
102 | __setup("selinux=", selinux_enabled_setup); | |
103 | #endif | |
104 | ||
105 | /* Original (dummy) security module. */ | |
106 | static struct security_operations *original_ops = NULL; | |
107 | ||
108 | /* Minimal support for a secondary security module, | |
109 | just to allow the use of the dummy or capability modules. | |
110 | The owlsm module can alternatively be used as a secondary | |
111 | module as long as CONFIG_OWLSM_FD is not enabled. */ | |
112 | static struct security_operations *secondary_ops = NULL; | |
113 | ||
114 | /* Lists of inode and superblock security structures initialized | |
115 | before the policy was loaded. */ | |
116 | static LIST_HEAD(superblock_security_head); | |
117 | static DEFINE_SPINLOCK(sb_security_lock); | |
118 | ||
119 | /* Allocate and free functions for each kind of security blob. */ | |
120 | ||
121 | static int task_alloc_security(struct task_struct *task) | |
122 | { | |
123 | struct task_security_struct *tsec; | |
124 | ||
125 | tsec = kmalloc(sizeof(struct task_security_struct), GFP_KERNEL); | |
126 | if (!tsec) | |
127 | return -ENOMEM; | |
128 | ||
129 | memset(tsec, 0, sizeof(struct task_security_struct)); | |
130 | tsec->magic = SELINUX_MAGIC; | |
131 | tsec->task = task; | |
132 | tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED; | |
133 | task->security = tsec; | |
134 | ||
135 | return 0; | |
136 | } | |
137 | ||
138 | static void task_free_security(struct task_struct *task) | |
139 | { | |
140 | struct task_security_struct *tsec = task->security; | |
141 | ||
142 | if (!tsec || tsec->magic != SELINUX_MAGIC) | |
143 | return; | |
144 | ||
145 | task->security = NULL; | |
146 | kfree(tsec); | |
147 | } | |
148 | ||
149 | static int inode_alloc_security(struct inode *inode) | |
150 | { | |
151 | struct task_security_struct *tsec = current->security; | |
152 | struct inode_security_struct *isec; | |
153 | ||
154 | isec = kmalloc(sizeof(struct inode_security_struct), GFP_KERNEL); | |
155 | if (!isec) | |
156 | return -ENOMEM; | |
157 | ||
158 | memset(isec, 0, sizeof(struct inode_security_struct)); | |
159 | init_MUTEX(&isec->sem); | |
160 | INIT_LIST_HEAD(&isec->list); | |
161 | isec->magic = SELINUX_MAGIC; | |
162 | isec->inode = inode; | |
163 | isec->sid = SECINITSID_UNLABELED; | |
164 | isec->sclass = SECCLASS_FILE; | |
165 | if (tsec && tsec->magic == SELINUX_MAGIC) | |
166 | isec->task_sid = tsec->sid; | |
167 | else | |
168 | isec->task_sid = SECINITSID_UNLABELED; | |
169 | inode->i_security = isec; | |
170 | ||
171 | return 0; | |
172 | } | |
173 | ||
174 | static void inode_free_security(struct inode *inode) | |
175 | { | |
176 | struct inode_security_struct *isec = inode->i_security; | |
177 | struct superblock_security_struct *sbsec = inode->i_sb->s_security; | |
178 | ||
179 | if (!isec || isec->magic != SELINUX_MAGIC) | |
180 | return; | |
181 | ||
182 | spin_lock(&sbsec->isec_lock); | |
183 | if (!list_empty(&isec->list)) | |
184 | list_del_init(&isec->list); | |
185 | spin_unlock(&sbsec->isec_lock); | |
186 | ||
187 | inode->i_security = NULL; | |
188 | kfree(isec); | |
189 | } | |
190 | ||
191 | static int file_alloc_security(struct file *file) | |
192 | { | |
193 | struct task_security_struct *tsec = current->security; | |
194 | struct file_security_struct *fsec; | |
195 | ||
196 | fsec = kmalloc(sizeof(struct file_security_struct), GFP_ATOMIC); | |
197 | if (!fsec) | |
198 | return -ENOMEM; | |
199 | ||
200 | memset(fsec, 0, sizeof(struct file_security_struct)); | |
201 | fsec->magic = SELINUX_MAGIC; | |
202 | fsec->file = file; | |
203 | if (tsec && tsec->magic == SELINUX_MAGIC) { | |
204 | fsec->sid = tsec->sid; | |
205 | fsec->fown_sid = tsec->sid; | |
206 | } else { | |
207 | fsec->sid = SECINITSID_UNLABELED; | |
208 | fsec->fown_sid = SECINITSID_UNLABELED; | |
209 | } | |
210 | file->f_security = fsec; | |
211 | ||
212 | return 0; | |
213 | } | |
214 | ||
215 | static void file_free_security(struct file *file) | |
216 | { | |
217 | struct file_security_struct *fsec = file->f_security; | |
218 | ||
219 | if (!fsec || fsec->magic != SELINUX_MAGIC) | |
220 | return; | |
221 | ||
222 | file->f_security = NULL; | |
223 | kfree(fsec); | |
224 | } | |
225 | ||
226 | static int superblock_alloc_security(struct super_block *sb) | |
227 | { | |
228 | struct superblock_security_struct *sbsec; | |
229 | ||
230 | sbsec = kmalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); | |
231 | if (!sbsec) | |
232 | return -ENOMEM; | |
233 | ||
234 | memset(sbsec, 0, sizeof(struct superblock_security_struct)); | |
235 | init_MUTEX(&sbsec->sem); | |
236 | INIT_LIST_HEAD(&sbsec->list); | |
237 | INIT_LIST_HEAD(&sbsec->isec_head); | |
238 | spin_lock_init(&sbsec->isec_lock); | |
239 | sbsec->magic = SELINUX_MAGIC; | |
240 | sbsec->sb = sb; | |
241 | sbsec->sid = SECINITSID_UNLABELED; | |
242 | sbsec->def_sid = SECINITSID_FILE; | |
243 | sb->s_security = sbsec; | |
244 | ||
245 | return 0; | |
246 | } | |
247 | ||
248 | static void superblock_free_security(struct super_block *sb) | |
249 | { | |
250 | struct superblock_security_struct *sbsec = sb->s_security; | |
251 | ||
252 | if (!sbsec || sbsec->magic != SELINUX_MAGIC) | |
253 | return; | |
254 | ||
255 | spin_lock(&sb_security_lock); | |
256 | if (!list_empty(&sbsec->list)) | |
257 | list_del_init(&sbsec->list); | |
258 | spin_unlock(&sb_security_lock); | |
259 | ||
260 | sb->s_security = NULL; | |
261 | kfree(sbsec); | |
262 | } | |
263 | ||
264 | #ifdef CONFIG_SECURITY_NETWORK | |
265 | static int sk_alloc_security(struct sock *sk, int family, int priority) | |
266 | { | |
267 | struct sk_security_struct *ssec; | |
268 | ||
269 | if (family != PF_UNIX) | |
270 | return 0; | |
271 | ||
272 | ssec = kmalloc(sizeof(*ssec), priority); | |
273 | if (!ssec) | |
274 | return -ENOMEM; | |
275 | ||
276 | memset(ssec, 0, sizeof(*ssec)); | |
277 | ssec->magic = SELINUX_MAGIC; | |
278 | ssec->sk = sk; | |
279 | ssec->peer_sid = SECINITSID_UNLABELED; | |
280 | sk->sk_security = ssec; | |
281 | ||
282 | return 0; | |
283 | } | |
284 | ||
285 | static void sk_free_security(struct sock *sk) | |
286 | { | |
287 | struct sk_security_struct *ssec = sk->sk_security; | |
288 | ||
289 | if (sk->sk_family != PF_UNIX || ssec->magic != SELINUX_MAGIC) | |
290 | return; | |
291 | ||
292 | sk->sk_security = NULL; | |
293 | kfree(ssec); | |
294 | } | |
295 | #endif /* CONFIG_SECURITY_NETWORK */ | |
296 | ||
297 | /* The security server must be initialized before | |
298 | any labeling or access decisions can be provided. */ | |
299 | extern int ss_initialized; | |
300 | ||
301 | /* The file system's label must be initialized prior to use. */ | |
302 | ||
303 | static char *labeling_behaviors[6] = { | |
304 | "uses xattr", | |
305 | "uses transition SIDs", | |
306 | "uses task SIDs", | |
307 | "uses genfs_contexts", | |
308 | "not configured for labeling", | |
309 | "uses mountpoint labeling", | |
310 | }; | |
311 | ||
312 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); | |
313 | ||
314 | static inline int inode_doinit(struct inode *inode) | |
315 | { | |
316 | return inode_doinit_with_dentry(inode, NULL); | |
317 | } | |
318 | ||
319 | enum { | |
320 | Opt_context = 1, | |
321 | Opt_fscontext = 2, | |
322 | Opt_defcontext = 4, | |
323 | }; | |
324 | ||
325 | static match_table_t tokens = { | |
326 | {Opt_context, "context=%s"}, | |
327 | {Opt_fscontext, "fscontext=%s"}, | |
328 | {Opt_defcontext, "defcontext=%s"}, | |
329 | }; | |
330 | ||
331 | #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" | |
332 | ||
333 | static int try_context_mount(struct super_block *sb, void *data) | |
334 | { | |
335 | char *context = NULL, *defcontext = NULL; | |
336 | const char *name; | |
337 | u32 sid; | |
338 | int alloc = 0, rc = 0, seen = 0; | |
339 | struct task_security_struct *tsec = current->security; | |
340 | struct superblock_security_struct *sbsec = sb->s_security; | |
341 | ||
342 | if (!data) | |
343 | goto out; | |
344 | ||
345 | name = sb->s_type->name; | |
346 | ||
347 | if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) { | |
348 | ||
349 | /* NFS we understand. */ | |
350 | if (!strcmp(name, "nfs")) { | |
351 | struct nfs_mount_data *d = data; | |
352 | ||
353 | if (d->version < NFS_MOUNT_VERSION) | |
354 | goto out; | |
355 | ||
356 | if (d->context[0]) { | |
357 | context = d->context; | |
358 | seen |= Opt_context; | |
359 | } | |
360 | } else | |
361 | goto out; | |
362 | ||
363 | } else { | |
364 | /* Standard string-based options. */ | |
365 | char *p, *options = data; | |
366 | ||
367 | while ((p = strsep(&options, ",")) != NULL) { | |
368 | int token; | |
369 | substring_t args[MAX_OPT_ARGS]; | |
370 | ||
371 | if (!*p) | |
372 | continue; | |
373 | ||
374 | token = match_token(p, tokens, args); | |
375 | ||
376 | switch (token) { | |
377 | case Opt_context: | |
378 | if (seen) { | |
379 | rc = -EINVAL; | |
380 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
381 | goto out_free; | |
382 | } | |
383 | context = match_strdup(&args[0]); | |
384 | if (!context) { | |
385 | rc = -ENOMEM; | |
386 | goto out_free; | |
387 | } | |
388 | if (!alloc) | |
389 | alloc = 1; | |
390 | seen |= Opt_context; | |
391 | break; | |
392 | ||
393 | case Opt_fscontext: | |
394 | if (seen & (Opt_context|Opt_fscontext)) { | |
395 | rc = -EINVAL; | |
396 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
397 | goto out_free; | |
398 | } | |
399 | context = match_strdup(&args[0]); | |
400 | if (!context) { | |
401 | rc = -ENOMEM; | |
402 | goto out_free; | |
403 | } | |
404 | if (!alloc) | |
405 | alloc = 1; | |
406 | seen |= Opt_fscontext; | |
407 | break; | |
408 | ||
409 | case Opt_defcontext: | |
410 | if (sbsec->behavior != SECURITY_FS_USE_XATTR) { | |
411 | rc = -EINVAL; | |
412 | printk(KERN_WARNING "SELinux: " | |
413 | "defcontext option is invalid " | |
414 | "for this filesystem type\n"); | |
415 | goto out_free; | |
416 | } | |
417 | if (seen & (Opt_context|Opt_defcontext)) { | |
418 | rc = -EINVAL; | |
419 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
420 | goto out_free; | |
421 | } | |
422 | defcontext = match_strdup(&args[0]); | |
423 | if (!defcontext) { | |
424 | rc = -ENOMEM; | |
425 | goto out_free; | |
426 | } | |
427 | if (!alloc) | |
428 | alloc = 1; | |
429 | seen |= Opt_defcontext; | |
430 | break; | |
431 | ||
432 | default: | |
433 | rc = -EINVAL; | |
434 | printk(KERN_WARNING "SELinux: unknown mount " | |
435 | "option\n"); | |
436 | goto out_free; | |
437 | ||
438 | } | |
439 | } | |
440 | } | |
441 | ||
442 | if (!seen) | |
443 | goto out; | |
444 | ||
445 | if (context) { | |
446 | rc = security_context_to_sid(context, strlen(context), &sid); | |
447 | if (rc) { | |
448 | printk(KERN_WARNING "SELinux: security_context_to_sid" | |
449 | "(%s) failed for (dev %s, type %s) errno=%d\n", | |
450 | context, sb->s_id, name, rc); | |
451 | goto out_free; | |
452 | } | |
453 | ||
454 | rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
455 | FILESYSTEM__RELABELFROM, NULL); | |
456 | if (rc) | |
457 | goto out_free; | |
458 | ||
459 | rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM, | |
460 | FILESYSTEM__RELABELTO, NULL); | |
461 | if (rc) | |
462 | goto out_free; | |
463 | ||
464 | sbsec->sid = sid; | |
465 | ||
466 | if (seen & Opt_context) | |
467 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; | |
468 | } | |
469 | ||
470 | if (defcontext) { | |
471 | rc = security_context_to_sid(defcontext, strlen(defcontext), &sid); | |
472 | if (rc) { | |
473 | printk(KERN_WARNING "SELinux: security_context_to_sid" | |
474 | "(%s) failed for (dev %s, type %s) errno=%d\n", | |
475 | defcontext, sb->s_id, name, rc); | |
476 | goto out_free; | |
477 | } | |
478 | ||
479 | if (sid == sbsec->def_sid) | |
480 | goto out_free; | |
481 | ||
482 | rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
483 | FILESYSTEM__RELABELFROM, NULL); | |
484 | if (rc) | |
485 | goto out_free; | |
486 | ||
487 | rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
488 | FILESYSTEM__ASSOCIATE, NULL); | |
489 | if (rc) | |
490 | goto out_free; | |
491 | ||
492 | sbsec->def_sid = sid; | |
493 | } | |
494 | ||
495 | out_free: | |
496 | if (alloc) { | |
497 | kfree(context); | |
498 | kfree(defcontext); | |
499 | } | |
500 | out: | |
501 | return rc; | |
502 | } | |
503 | ||
504 | static int superblock_doinit(struct super_block *sb, void *data) | |
505 | { | |
506 | struct superblock_security_struct *sbsec = sb->s_security; | |
507 | struct dentry *root = sb->s_root; | |
508 | struct inode *inode = root->d_inode; | |
509 | int rc = 0; | |
510 | ||
511 | down(&sbsec->sem); | |
512 | if (sbsec->initialized) | |
513 | goto out; | |
514 | ||
515 | if (!ss_initialized) { | |
516 | /* Defer initialization until selinux_complete_init, | |
517 | after the initial policy is loaded and the security | |
518 | server is ready to handle calls. */ | |
519 | spin_lock(&sb_security_lock); | |
520 | if (list_empty(&sbsec->list)) | |
521 | list_add(&sbsec->list, &superblock_security_head); | |
522 | spin_unlock(&sb_security_lock); | |
523 | goto out; | |
524 | } | |
525 | ||
526 | /* Determine the labeling behavior to use for this filesystem type. */ | |
527 | rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid); | |
528 | if (rc) { | |
529 | printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n", | |
530 | __FUNCTION__, sb->s_type->name, rc); | |
531 | goto out; | |
532 | } | |
533 | ||
534 | rc = try_context_mount(sb, data); | |
535 | if (rc) | |
536 | goto out; | |
537 | ||
538 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { | |
539 | /* Make sure that the xattr handler exists and that no | |
540 | error other than -ENODATA is returned by getxattr on | |
541 | the root directory. -ENODATA is ok, as this may be | |
542 | the first boot of the SELinux kernel before we have | |
543 | assigned xattr values to the filesystem. */ | |
544 | if (!inode->i_op->getxattr) { | |
545 | printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " | |
546 | "xattr support\n", sb->s_id, sb->s_type->name); | |
547 | rc = -EOPNOTSUPP; | |
548 | goto out; | |
549 | } | |
550 | rc = inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0); | |
551 | if (rc < 0 && rc != -ENODATA) { | |
552 | if (rc == -EOPNOTSUPP) | |
553 | printk(KERN_WARNING "SELinux: (dev %s, type " | |
554 | "%s) has no security xattr handler\n", | |
555 | sb->s_id, sb->s_type->name); | |
556 | else | |
557 | printk(KERN_WARNING "SELinux: (dev %s, type " | |
558 | "%s) getxattr errno %d\n", sb->s_id, | |
559 | sb->s_type->name, -rc); | |
560 | goto out; | |
561 | } | |
562 | } | |
563 | ||
564 | if (strcmp(sb->s_type->name, "proc") == 0) | |
565 | sbsec->proc = 1; | |
566 | ||
567 | sbsec->initialized = 1; | |
568 | ||
569 | if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) { | |
570 | printk(KERN_INFO "SELinux: initialized (dev %s, type %s), unknown behavior\n", | |
571 | sb->s_id, sb->s_type->name); | |
572 | } | |
573 | else { | |
574 | printk(KERN_INFO "SELinux: initialized (dev %s, type %s), %s\n", | |
575 | sb->s_id, sb->s_type->name, | |
576 | labeling_behaviors[sbsec->behavior-1]); | |
577 | } | |
578 | ||
579 | /* Initialize the root inode. */ | |
580 | rc = inode_doinit_with_dentry(sb->s_root->d_inode, sb->s_root); | |
581 | ||
582 | /* Initialize any other inodes associated with the superblock, e.g. | |
583 | inodes created prior to initial policy load or inodes created | |
584 | during get_sb by a pseudo filesystem that directly | |
585 | populates itself. */ | |
586 | spin_lock(&sbsec->isec_lock); | |
587 | next_inode: | |
588 | if (!list_empty(&sbsec->isec_head)) { | |
589 | struct inode_security_struct *isec = | |
590 | list_entry(sbsec->isec_head.next, | |
591 | struct inode_security_struct, list); | |
592 | struct inode *inode = isec->inode; | |
593 | spin_unlock(&sbsec->isec_lock); | |
594 | inode = igrab(inode); | |
595 | if (inode) { | |
596 | if (!IS_PRIVATE (inode)) | |
597 | inode_doinit(inode); | |
598 | iput(inode); | |
599 | } | |
600 | spin_lock(&sbsec->isec_lock); | |
601 | list_del_init(&isec->list); | |
602 | goto next_inode; | |
603 | } | |
604 | spin_unlock(&sbsec->isec_lock); | |
605 | out: | |
606 | up(&sbsec->sem); | |
607 | return rc; | |
608 | } | |
609 | ||
610 | static inline u16 inode_mode_to_security_class(umode_t mode) | |
611 | { | |
612 | switch (mode & S_IFMT) { | |
613 | case S_IFSOCK: | |
614 | return SECCLASS_SOCK_FILE; | |
615 | case S_IFLNK: | |
616 | return SECCLASS_LNK_FILE; | |
617 | case S_IFREG: | |
618 | return SECCLASS_FILE; | |
619 | case S_IFBLK: | |
620 | return SECCLASS_BLK_FILE; | |
621 | case S_IFDIR: | |
622 | return SECCLASS_DIR; | |
623 | case S_IFCHR: | |
624 | return SECCLASS_CHR_FILE; | |
625 | case S_IFIFO: | |
626 | return SECCLASS_FIFO_FILE; | |
627 | ||
628 | } | |
629 | ||
630 | return SECCLASS_FILE; | |
631 | } | |
632 | ||
633 | static inline u16 socket_type_to_security_class(int family, int type, int protocol) | |
634 | { | |
635 | switch (family) { | |
636 | case PF_UNIX: | |
637 | switch (type) { | |
638 | case SOCK_STREAM: | |
639 | case SOCK_SEQPACKET: | |
640 | return SECCLASS_UNIX_STREAM_SOCKET; | |
641 | case SOCK_DGRAM: | |
642 | return SECCLASS_UNIX_DGRAM_SOCKET; | |
643 | } | |
644 | break; | |
645 | case PF_INET: | |
646 | case PF_INET6: | |
647 | switch (type) { | |
648 | case SOCK_STREAM: | |
649 | return SECCLASS_TCP_SOCKET; | |
650 | case SOCK_DGRAM: | |
651 | return SECCLASS_UDP_SOCKET; | |
652 | case SOCK_RAW: | |
653 | return SECCLASS_RAWIP_SOCKET; | |
654 | } | |
655 | break; | |
656 | case PF_NETLINK: | |
657 | switch (protocol) { | |
658 | case NETLINK_ROUTE: | |
659 | return SECCLASS_NETLINK_ROUTE_SOCKET; | |
660 | case NETLINK_FIREWALL: | |
661 | return SECCLASS_NETLINK_FIREWALL_SOCKET; | |
662 | case NETLINK_TCPDIAG: | |
663 | return SECCLASS_NETLINK_TCPDIAG_SOCKET; | |
664 | case NETLINK_NFLOG: | |
665 | return SECCLASS_NETLINK_NFLOG_SOCKET; | |
666 | case NETLINK_XFRM: | |
667 | return SECCLASS_NETLINK_XFRM_SOCKET; | |
668 | case NETLINK_SELINUX: | |
669 | return SECCLASS_NETLINK_SELINUX_SOCKET; | |
670 | case NETLINK_AUDIT: | |
671 | return SECCLASS_NETLINK_AUDIT_SOCKET; | |
672 | case NETLINK_IP6_FW: | |
673 | return SECCLASS_NETLINK_IP6FW_SOCKET; | |
674 | case NETLINK_DNRTMSG: | |
675 | return SECCLASS_NETLINK_DNRT_SOCKET; | |
0c9b7942 JM |
676 | case NETLINK_KOBJECT_UEVENT: |
677 | return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; | |
1da177e4 LT |
678 | default: |
679 | return SECCLASS_NETLINK_SOCKET; | |
680 | } | |
681 | case PF_PACKET: | |
682 | return SECCLASS_PACKET_SOCKET; | |
683 | case PF_KEY: | |
684 | return SECCLASS_KEY_SOCKET; | |
685 | } | |
686 | ||
687 | return SECCLASS_SOCKET; | |
688 | } | |
689 | ||
690 | #ifdef CONFIG_PROC_FS | |
691 | static int selinux_proc_get_sid(struct proc_dir_entry *de, | |
692 | u16 tclass, | |
693 | u32 *sid) | |
694 | { | |
695 | int buflen, rc; | |
696 | char *buffer, *path, *end; | |
697 | ||
698 | buffer = (char*)__get_free_page(GFP_KERNEL); | |
699 | if (!buffer) | |
700 | return -ENOMEM; | |
701 | ||
702 | buflen = PAGE_SIZE; | |
703 | end = buffer+buflen; | |
704 | *--end = '\0'; | |
705 | buflen--; | |
706 | path = end-1; | |
707 | *path = '/'; | |
708 | while (de && de != de->parent) { | |
709 | buflen -= de->namelen + 1; | |
710 | if (buflen < 0) | |
711 | break; | |
712 | end -= de->namelen; | |
713 | memcpy(end, de->name, de->namelen); | |
714 | *--end = '/'; | |
715 | path = end; | |
716 | de = de->parent; | |
717 | } | |
718 | rc = security_genfs_sid("proc", path, tclass, sid); | |
719 | free_page((unsigned long)buffer); | |
720 | return rc; | |
721 | } | |
722 | #else | |
723 | static int selinux_proc_get_sid(struct proc_dir_entry *de, | |
724 | u16 tclass, | |
725 | u32 *sid) | |
726 | { | |
727 | return -EINVAL; | |
728 | } | |
729 | #endif | |
730 | ||
731 | /* The inode's security attributes must be initialized before first use. */ | |
732 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) | |
733 | { | |
734 | struct superblock_security_struct *sbsec = NULL; | |
735 | struct inode_security_struct *isec = inode->i_security; | |
736 | u32 sid; | |
737 | struct dentry *dentry; | |
738 | #define INITCONTEXTLEN 255 | |
739 | char *context = NULL; | |
740 | unsigned len = 0; | |
741 | int rc = 0; | |
742 | int hold_sem = 0; | |
743 | ||
744 | if (isec->initialized) | |
745 | goto out; | |
746 | ||
747 | down(&isec->sem); | |
748 | hold_sem = 1; | |
749 | if (isec->initialized) | |
750 | goto out; | |
751 | ||
752 | sbsec = inode->i_sb->s_security; | |
753 | if (!sbsec->initialized) { | |
754 | /* Defer initialization until selinux_complete_init, | |
755 | after the initial policy is loaded and the security | |
756 | server is ready to handle calls. */ | |
757 | spin_lock(&sbsec->isec_lock); | |
758 | if (list_empty(&isec->list)) | |
759 | list_add(&isec->list, &sbsec->isec_head); | |
760 | spin_unlock(&sbsec->isec_lock); | |
761 | goto out; | |
762 | } | |
763 | ||
764 | switch (sbsec->behavior) { | |
765 | case SECURITY_FS_USE_XATTR: | |
766 | if (!inode->i_op->getxattr) { | |
767 | isec->sid = sbsec->def_sid; | |
768 | break; | |
769 | } | |
770 | ||
771 | /* Need a dentry, since the xattr API requires one. | |
772 | Life would be simpler if we could just pass the inode. */ | |
773 | if (opt_dentry) { | |
774 | /* Called from d_instantiate or d_splice_alias. */ | |
775 | dentry = dget(opt_dentry); | |
776 | } else { | |
777 | /* Called from selinux_complete_init, try to find a dentry. */ | |
778 | dentry = d_find_alias(inode); | |
779 | } | |
780 | if (!dentry) { | |
781 | printk(KERN_WARNING "%s: no dentry for dev=%s " | |
782 | "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id, | |
783 | inode->i_ino); | |
784 | goto out; | |
785 | } | |
786 | ||
787 | len = INITCONTEXTLEN; | |
788 | context = kmalloc(len, GFP_KERNEL); | |
789 | if (!context) { | |
790 | rc = -ENOMEM; | |
791 | dput(dentry); | |
792 | goto out; | |
793 | } | |
794 | rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, | |
795 | context, len); | |
796 | if (rc == -ERANGE) { | |
797 | /* Need a larger buffer. Query for the right size. */ | |
798 | rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, | |
799 | NULL, 0); | |
800 | if (rc < 0) { | |
801 | dput(dentry); | |
802 | goto out; | |
803 | } | |
804 | kfree(context); | |
805 | len = rc; | |
806 | context = kmalloc(len, GFP_KERNEL); | |
807 | if (!context) { | |
808 | rc = -ENOMEM; | |
809 | dput(dentry); | |
810 | goto out; | |
811 | } | |
812 | rc = inode->i_op->getxattr(dentry, | |
813 | XATTR_NAME_SELINUX, | |
814 | context, len); | |
815 | } | |
816 | dput(dentry); | |
817 | if (rc < 0) { | |
818 | if (rc != -ENODATA) { | |
819 | printk(KERN_WARNING "%s: getxattr returned " | |
820 | "%d for dev=%s ino=%ld\n", __FUNCTION__, | |
821 | -rc, inode->i_sb->s_id, inode->i_ino); | |
822 | kfree(context); | |
823 | goto out; | |
824 | } | |
825 | /* Map ENODATA to the default file SID */ | |
826 | sid = sbsec->def_sid; | |
827 | rc = 0; | |
828 | } else { | |
f5c1d5b2 JM |
829 | rc = security_context_to_sid_default(context, rc, &sid, |
830 | sbsec->def_sid); | |
1da177e4 LT |
831 | if (rc) { |
832 | printk(KERN_WARNING "%s: context_to_sid(%s) " | |
833 | "returned %d for dev=%s ino=%ld\n", | |
834 | __FUNCTION__, context, -rc, | |
835 | inode->i_sb->s_id, inode->i_ino); | |
836 | kfree(context); | |
837 | /* Leave with the unlabeled SID */ | |
838 | rc = 0; | |
839 | break; | |
840 | } | |
841 | } | |
842 | kfree(context); | |
843 | isec->sid = sid; | |
844 | break; | |
845 | case SECURITY_FS_USE_TASK: | |
846 | isec->sid = isec->task_sid; | |
847 | break; | |
848 | case SECURITY_FS_USE_TRANS: | |
849 | /* Default to the fs SID. */ | |
850 | isec->sid = sbsec->sid; | |
851 | ||
852 | /* Try to obtain a transition SID. */ | |
853 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
854 | rc = security_transition_sid(isec->task_sid, | |
855 | sbsec->sid, | |
856 | isec->sclass, | |
857 | &sid); | |
858 | if (rc) | |
859 | goto out; | |
860 | isec->sid = sid; | |
861 | break; | |
862 | default: | |
863 | /* Default to the fs SID. */ | |
864 | isec->sid = sbsec->sid; | |
865 | ||
866 | if (sbsec->proc) { | |
867 | struct proc_inode *proci = PROC_I(inode); | |
868 | if (proci->pde) { | |
869 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
870 | rc = selinux_proc_get_sid(proci->pde, | |
871 | isec->sclass, | |
872 | &sid); | |
873 | if (rc) | |
874 | goto out; | |
875 | isec->sid = sid; | |
876 | } | |
877 | } | |
878 | break; | |
879 | } | |
880 | ||
881 | isec->initialized = 1; | |
882 | ||
883 | out: | |
884 | if (isec->sclass == SECCLASS_FILE) | |
885 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
886 | ||
887 | if (hold_sem) | |
888 | up(&isec->sem); | |
889 | return rc; | |
890 | } | |
891 | ||
892 | /* Convert a Linux signal to an access vector. */ | |
893 | static inline u32 signal_to_av(int sig) | |
894 | { | |
895 | u32 perm = 0; | |
896 | ||
897 | switch (sig) { | |
898 | case SIGCHLD: | |
899 | /* Commonly granted from child to parent. */ | |
900 | perm = PROCESS__SIGCHLD; | |
901 | break; | |
902 | case SIGKILL: | |
903 | /* Cannot be caught or ignored */ | |
904 | perm = PROCESS__SIGKILL; | |
905 | break; | |
906 | case SIGSTOP: | |
907 | /* Cannot be caught or ignored */ | |
908 | perm = PROCESS__SIGSTOP; | |
909 | break; | |
910 | default: | |
911 | /* All other signals. */ | |
912 | perm = PROCESS__SIGNAL; | |
913 | break; | |
914 | } | |
915 | ||
916 | return perm; | |
917 | } | |
918 | ||
919 | /* Check permission betweeen a pair of tasks, e.g. signal checks, | |
920 | fork check, ptrace check, etc. */ | |
921 | static int task_has_perm(struct task_struct *tsk1, | |
922 | struct task_struct *tsk2, | |
923 | u32 perms) | |
924 | { | |
925 | struct task_security_struct *tsec1, *tsec2; | |
926 | ||
927 | tsec1 = tsk1->security; | |
928 | tsec2 = tsk2->security; | |
929 | return avc_has_perm(tsec1->sid, tsec2->sid, | |
930 | SECCLASS_PROCESS, perms, NULL); | |
931 | } | |
932 | ||
933 | /* Check whether a task is allowed to use a capability. */ | |
934 | static int task_has_capability(struct task_struct *tsk, | |
935 | int cap) | |
936 | { | |
937 | struct task_security_struct *tsec; | |
938 | struct avc_audit_data ad; | |
939 | ||
940 | tsec = tsk->security; | |
941 | ||
942 | AVC_AUDIT_DATA_INIT(&ad,CAP); | |
943 | ad.tsk = tsk; | |
944 | ad.u.cap = cap; | |
945 | ||
946 | return avc_has_perm(tsec->sid, tsec->sid, | |
947 | SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad); | |
948 | } | |
949 | ||
950 | /* Check whether a task is allowed to use a system operation. */ | |
951 | static int task_has_system(struct task_struct *tsk, | |
952 | u32 perms) | |
953 | { | |
954 | struct task_security_struct *tsec; | |
955 | ||
956 | tsec = tsk->security; | |
957 | ||
958 | return avc_has_perm(tsec->sid, SECINITSID_KERNEL, | |
959 | SECCLASS_SYSTEM, perms, NULL); | |
960 | } | |
961 | ||
962 | /* Check whether a task has a particular permission to an inode. | |
963 | The 'adp' parameter is optional and allows other audit | |
964 | data to be passed (e.g. the dentry). */ | |
965 | static int inode_has_perm(struct task_struct *tsk, | |
966 | struct inode *inode, | |
967 | u32 perms, | |
968 | struct avc_audit_data *adp) | |
969 | { | |
970 | struct task_security_struct *tsec; | |
971 | struct inode_security_struct *isec; | |
972 | struct avc_audit_data ad; | |
973 | ||
974 | tsec = tsk->security; | |
975 | isec = inode->i_security; | |
976 | ||
977 | if (!adp) { | |
978 | adp = &ad; | |
979 | AVC_AUDIT_DATA_INIT(&ad, FS); | |
980 | ad.u.fs.inode = inode; | |
981 | } | |
982 | ||
983 | return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp); | |
984 | } | |
985 | ||
986 | /* Same as inode_has_perm, but pass explicit audit data containing | |
987 | the dentry to help the auditing code to more easily generate the | |
988 | pathname if needed. */ | |
989 | static inline int dentry_has_perm(struct task_struct *tsk, | |
990 | struct vfsmount *mnt, | |
991 | struct dentry *dentry, | |
992 | u32 av) | |
993 | { | |
994 | struct inode *inode = dentry->d_inode; | |
995 | struct avc_audit_data ad; | |
996 | AVC_AUDIT_DATA_INIT(&ad,FS); | |
997 | ad.u.fs.mnt = mnt; | |
998 | ad.u.fs.dentry = dentry; | |
999 | return inode_has_perm(tsk, inode, av, &ad); | |
1000 | } | |
1001 | ||
1002 | /* Check whether a task can use an open file descriptor to | |
1003 | access an inode in a given way. Check access to the | |
1004 | descriptor itself, and then use dentry_has_perm to | |
1005 | check a particular permission to the file. | |
1006 | Access to the descriptor is implicitly granted if it | |
1007 | has the same SID as the process. If av is zero, then | |
1008 | access to the file is not checked, e.g. for cases | |
1009 | where only the descriptor is affected like seek. */ | |
1010 | static inline int file_has_perm(struct task_struct *tsk, | |
1011 | struct file *file, | |
1012 | u32 av) | |
1013 | { | |
1014 | struct task_security_struct *tsec = tsk->security; | |
1015 | struct file_security_struct *fsec = file->f_security; | |
1016 | struct vfsmount *mnt = file->f_vfsmnt; | |
1017 | struct dentry *dentry = file->f_dentry; | |
1018 | struct inode *inode = dentry->d_inode; | |
1019 | struct avc_audit_data ad; | |
1020 | int rc; | |
1021 | ||
1022 | AVC_AUDIT_DATA_INIT(&ad, FS); | |
1023 | ad.u.fs.mnt = mnt; | |
1024 | ad.u.fs.dentry = dentry; | |
1025 | ||
1026 | if (tsec->sid != fsec->sid) { | |
1027 | rc = avc_has_perm(tsec->sid, fsec->sid, | |
1028 | SECCLASS_FD, | |
1029 | FD__USE, | |
1030 | &ad); | |
1031 | if (rc) | |
1032 | return rc; | |
1033 | } | |
1034 | ||
1035 | /* av is zero if only checking access to the descriptor. */ | |
1036 | if (av) | |
1037 | return inode_has_perm(tsk, inode, av, &ad); | |
1038 | ||
1039 | return 0; | |
1040 | } | |
1041 | ||
1042 | /* Check whether a task can create a file. */ | |
1043 | static int may_create(struct inode *dir, | |
1044 | struct dentry *dentry, | |
1045 | u16 tclass) | |
1046 | { | |
1047 | struct task_security_struct *tsec; | |
1048 | struct inode_security_struct *dsec; | |
1049 | struct superblock_security_struct *sbsec; | |
1050 | u32 newsid; | |
1051 | struct avc_audit_data ad; | |
1052 | int rc; | |
1053 | ||
1054 | tsec = current->security; | |
1055 | dsec = dir->i_security; | |
1056 | sbsec = dir->i_sb->s_security; | |
1057 | ||
1058 | AVC_AUDIT_DATA_INIT(&ad, FS); | |
1059 | ad.u.fs.dentry = dentry; | |
1060 | ||
1061 | rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, | |
1062 | DIR__ADD_NAME | DIR__SEARCH, | |
1063 | &ad); | |
1064 | if (rc) | |
1065 | return rc; | |
1066 | ||
1067 | if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { | |
1068 | newsid = tsec->create_sid; | |
1069 | } else { | |
1070 | rc = security_transition_sid(tsec->sid, dsec->sid, tclass, | |
1071 | &newsid); | |
1072 | if (rc) | |
1073 | return rc; | |
1074 | } | |
1075 | ||
1076 | rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad); | |
1077 | if (rc) | |
1078 | return rc; | |
1079 | ||
1080 | return avc_has_perm(newsid, sbsec->sid, | |
1081 | SECCLASS_FILESYSTEM, | |
1082 | FILESYSTEM__ASSOCIATE, &ad); | |
1083 | } | |
1084 | ||
1085 | #define MAY_LINK 0 | |
1086 | #define MAY_UNLINK 1 | |
1087 | #define MAY_RMDIR 2 | |
1088 | ||
1089 | /* Check whether a task can link, unlink, or rmdir a file/directory. */ | |
1090 | static int may_link(struct inode *dir, | |
1091 | struct dentry *dentry, | |
1092 | int kind) | |
1093 | ||
1094 | { | |
1095 | struct task_security_struct *tsec; | |
1096 | struct inode_security_struct *dsec, *isec; | |
1097 | struct avc_audit_data ad; | |
1098 | u32 av; | |
1099 | int rc; | |
1100 | ||
1101 | tsec = current->security; | |
1102 | dsec = dir->i_security; | |
1103 | isec = dentry->d_inode->i_security; | |
1104 | ||
1105 | AVC_AUDIT_DATA_INIT(&ad, FS); | |
1106 | ad.u.fs.dentry = dentry; | |
1107 | ||
1108 | av = DIR__SEARCH; | |
1109 | av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); | |
1110 | rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad); | |
1111 | if (rc) | |
1112 | return rc; | |
1113 | ||
1114 | switch (kind) { | |
1115 | case MAY_LINK: | |
1116 | av = FILE__LINK; | |
1117 | break; | |
1118 | case MAY_UNLINK: | |
1119 | av = FILE__UNLINK; | |
1120 | break; | |
1121 | case MAY_RMDIR: | |
1122 | av = DIR__RMDIR; | |
1123 | break; | |
1124 | default: | |
1125 | printk(KERN_WARNING "may_link: unrecognized kind %d\n", kind); | |
1126 | return 0; | |
1127 | } | |
1128 | ||
1129 | rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad); | |
1130 | return rc; | |
1131 | } | |
1132 | ||
1133 | static inline int may_rename(struct inode *old_dir, | |
1134 | struct dentry *old_dentry, | |
1135 | struct inode *new_dir, | |
1136 | struct dentry *new_dentry) | |
1137 | { | |
1138 | struct task_security_struct *tsec; | |
1139 | struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; | |
1140 | struct avc_audit_data ad; | |
1141 | u32 av; | |
1142 | int old_is_dir, new_is_dir; | |
1143 | int rc; | |
1144 | ||
1145 | tsec = current->security; | |
1146 | old_dsec = old_dir->i_security; | |
1147 | old_isec = old_dentry->d_inode->i_security; | |
1148 | old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode); | |
1149 | new_dsec = new_dir->i_security; | |
1150 | ||
1151 | AVC_AUDIT_DATA_INIT(&ad, FS); | |
1152 | ||
1153 | ad.u.fs.dentry = old_dentry; | |
1154 | rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR, | |
1155 | DIR__REMOVE_NAME | DIR__SEARCH, &ad); | |
1156 | if (rc) | |
1157 | return rc; | |
1158 | rc = avc_has_perm(tsec->sid, old_isec->sid, | |
1159 | old_isec->sclass, FILE__RENAME, &ad); | |
1160 | if (rc) | |
1161 | return rc; | |
1162 | if (old_is_dir && new_dir != old_dir) { | |
1163 | rc = avc_has_perm(tsec->sid, old_isec->sid, | |
1164 | old_isec->sclass, DIR__REPARENT, &ad); | |
1165 | if (rc) | |
1166 | return rc; | |
1167 | } | |
1168 | ||
1169 | ad.u.fs.dentry = new_dentry; | |
1170 | av = DIR__ADD_NAME | DIR__SEARCH; | |
1171 | if (new_dentry->d_inode) | |
1172 | av |= DIR__REMOVE_NAME; | |
1173 | rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad); | |
1174 | if (rc) | |
1175 | return rc; | |
1176 | if (new_dentry->d_inode) { | |
1177 | new_isec = new_dentry->d_inode->i_security; | |
1178 | new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode); | |
1179 | rc = avc_has_perm(tsec->sid, new_isec->sid, | |
1180 | new_isec->sclass, | |
1181 | (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); | |
1182 | if (rc) | |
1183 | return rc; | |
1184 | } | |
1185 | ||
1186 | return 0; | |
1187 | } | |
1188 | ||
1189 | /* Check whether a task can perform a filesystem operation. */ | |
1190 | static int superblock_has_perm(struct task_struct *tsk, | |
1191 | struct super_block *sb, | |
1192 | u32 perms, | |
1193 | struct avc_audit_data *ad) | |
1194 | { | |
1195 | struct task_security_struct *tsec; | |
1196 | struct superblock_security_struct *sbsec; | |
1197 | ||
1198 | tsec = tsk->security; | |
1199 | sbsec = sb->s_security; | |
1200 | return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
1201 | perms, ad); | |
1202 | } | |
1203 | ||
1204 | /* Convert a Linux mode and permission mask to an access vector. */ | |
1205 | static inline u32 file_mask_to_av(int mode, int mask) | |
1206 | { | |
1207 | u32 av = 0; | |
1208 | ||
1209 | if ((mode & S_IFMT) != S_IFDIR) { | |
1210 | if (mask & MAY_EXEC) | |
1211 | av |= FILE__EXECUTE; | |
1212 | if (mask & MAY_READ) | |
1213 | av |= FILE__READ; | |
1214 | ||
1215 | if (mask & MAY_APPEND) | |
1216 | av |= FILE__APPEND; | |
1217 | else if (mask & MAY_WRITE) | |
1218 | av |= FILE__WRITE; | |
1219 | ||
1220 | } else { | |
1221 | if (mask & MAY_EXEC) | |
1222 | av |= DIR__SEARCH; | |
1223 | if (mask & MAY_WRITE) | |
1224 | av |= DIR__WRITE; | |
1225 | if (mask & MAY_READ) | |
1226 | av |= DIR__READ; | |
1227 | } | |
1228 | ||
1229 | return av; | |
1230 | } | |
1231 | ||
1232 | /* Convert a Linux file to an access vector. */ | |
1233 | static inline u32 file_to_av(struct file *file) | |
1234 | { | |
1235 | u32 av = 0; | |
1236 | ||
1237 | if (file->f_mode & FMODE_READ) | |
1238 | av |= FILE__READ; | |
1239 | if (file->f_mode & FMODE_WRITE) { | |
1240 | if (file->f_flags & O_APPEND) | |
1241 | av |= FILE__APPEND; | |
1242 | else | |
1243 | av |= FILE__WRITE; | |
1244 | } | |
1245 | ||
1246 | return av; | |
1247 | } | |
1248 | ||
1249 | /* Set an inode's SID to a specified value. */ | |
1250 | static int inode_security_set_sid(struct inode *inode, u32 sid) | |
1251 | { | |
1252 | struct inode_security_struct *isec = inode->i_security; | |
1253 | struct superblock_security_struct *sbsec = inode->i_sb->s_security; | |
1254 | ||
1255 | if (!sbsec->initialized) { | |
1256 | /* Defer initialization to selinux_complete_init. */ | |
1257 | return 0; | |
1258 | } | |
1259 | ||
1260 | down(&isec->sem); | |
1261 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
1262 | isec->sid = sid; | |
1263 | isec->initialized = 1; | |
1264 | up(&isec->sem); | |
1265 | return 0; | |
1266 | } | |
1267 | ||
1268 | /* Set the security attributes on a newly created file. */ | |
1269 | static int post_create(struct inode *dir, | |
1270 | struct dentry *dentry) | |
1271 | { | |
1272 | ||
1273 | struct task_security_struct *tsec; | |
1274 | struct inode *inode; | |
1275 | struct inode_security_struct *dsec; | |
1276 | struct superblock_security_struct *sbsec; | |
1277 | u32 newsid; | |
1278 | char *context; | |
1279 | unsigned int len; | |
1280 | int rc; | |
1281 | ||
1282 | tsec = current->security; | |
1283 | dsec = dir->i_security; | |
1284 | sbsec = dir->i_sb->s_security; | |
1285 | ||
1286 | inode = dentry->d_inode; | |
1287 | if (!inode) { | |
1288 | /* Some file system types (e.g. NFS) may not instantiate | |
1289 | a dentry for all create operations (e.g. symlink), | |
1290 | so we have to check to see if the inode is non-NULL. */ | |
1291 | printk(KERN_WARNING "post_create: no inode, dir (dev=%s, " | |
1292 | "ino=%ld)\n", dir->i_sb->s_id, dir->i_ino); | |
1293 | return 0; | |
1294 | } | |
1295 | ||
1296 | if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { | |
1297 | newsid = tsec->create_sid; | |
1298 | } else { | |
1299 | rc = security_transition_sid(tsec->sid, dsec->sid, | |
1300 | inode_mode_to_security_class(inode->i_mode), | |
1301 | &newsid); | |
1302 | if (rc) { | |
1303 | printk(KERN_WARNING "post_create: " | |
1304 | "security_transition_sid failed, rc=%d (dev=%s " | |
1305 | "ino=%ld)\n", | |
1306 | -rc, inode->i_sb->s_id, inode->i_ino); | |
1307 | return rc; | |
1308 | } | |
1309 | } | |
1310 | ||
1311 | rc = inode_security_set_sid(inode, newsid); | |
1312 | if (rc) { | |
1313 | printk(KERN_WARNING "post_create: inode_security_set_sid " | |
1314 | "failed, rc=%d (dev=%s ino=%ld)\n", | |
1315 | -rc, inode->i_sb->s_id, inode->i_ino); | |
1316 | return rc; | |
1317 | } | |
1318 | ||
1319 | if (sbsec->behavior == SECURITY_FS_USE_XATTR && | |
1320 | inode->i_op->setxattr) { | |
1321 | /* Use extended attributes. */ | |
1322 | rc = security_sid_to_context(newsid, &context, &len); | |
1323 | if (rc) { | |
1324 | printk(KERN_WARNING "post_create: sid_to_context " | |
1325 | "failed, rc=%d (dev=%s ino=%ld)\n", | |
1326 | -rc, inode->i_sb->s_id, inode->i_ino); | |
1327 | return rc; | |
1328 | } | |
1329 | down(&inode->i_sem); | |
1330 | rc = inode->i_op->setxattr(dentry, | |
1331 | XATTR_NAME_SELINUX, | |
1332 | context, len, 0); | |
1333 | up(&inode->i_sem); | |
1334 | kfree(context); | |
1335 | if (rc < 0) { | |
1336 | printk(KERN_WARNING "post_create: setxattr failed, " | |
1337 | "rc=%d (dev=%s ino=%ld)\n", | |
1338 | -rc, inode->i_sb->s_id, inode->i_ino); | |
1339 | return rc; | |
1340 | } | |
1341 | } | |
1342 | ||
1343 | return 0; | |
1344 | } | |
1345 | ||
1346 | ||
1347 | /* Hook functions begin here. */ | |
1348 | ||
1349 | static int selinux_ptrace(struct task_struct *parent, struct task_struct *child) | |
1350 | { | |
1351 | struct task_security_struct *psec = parent->security; | |
1352 | struct task_security_struct *csec = child->security; | |
1353 | int rc; | |
1354 | ||
1355 | rc = secondary_ops->ptrace(parent,child); | |
1356 | if (rc) | |
1357 | return rc; | |
1358 | ||
1359 | rc = task_has_perm(parent, child, PROCESS__PTRACE); | |
1360 | /* Save the SID of the tracing process for later use in apply_creds. */ | |
1361 | if (!rc) | |
1362 | csec->ptrace_sid = psec->sid; | |
1363 | return rc; | |
1364 | } | |
1365 | ||
1366 | static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, | |
1367 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
1368 | { | |
1369 | int error; | |
1370 | ||
1371 | error = task_has_perm(current, target, PROCESS__GETCAP); | |
1372 | if (error) | |
1373 | return error; | |
1374 | ||
1375 | return secondary_ops->capget(target, effective, inheritable, permitted); | |
1376 | } | |
1377 | ||
1378 | static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective, | |
1379 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
1380 | { | |
1381 | int error; | |
1382 | ||
1383 | error = secondary_ops->capset_check(target, effective, inheritable, permitted); | |
1384 | if (error) | |
1385 | return error; | |
1386 | ||
1387 | return task_has_perm(current, target, PROCESS__SETCAP); | |
1388 | } | |
1389 | ||
1390 | static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective, | |
1391 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
1392 | { | |
1393 | secondary_ops->capset_set(target, effective, inheritable, permitted); | |
1394 | } | |
1395 | ||
1396 | static int selinux_capable(struct task_struct *tsk, int cap) | |
1397 | { | |
1398 | int rc; | |
1399 | ||
1400 | rc = secondary_ops->capable(tsk, cap); | |
1401 | if (rc) | |
1402 | return rc; | |
1403 | ||
1404 | return task_has_capability(tsk,cap); | |
1405 | } | |
1406 | ||
1407 | static int selinux_sysctl(ctl_table *table, int op) | |
1408 | { | |
1409 | int error = 0; | |
1410 | u32 av; | |
1411 | struct task_security_struct *tsec; | |
1412 | u32 tsid; | |
1413 | int rc; | |
1414 | ||
1415 | rc = secondary_ops->sysctl(table, op); | |
1416 | if (rc) | |
1417 | return rc; | |
1418 | ||
1419 | tsec = current->security; | |
1420 | ||
1421 | rc = selinux_proc_get_sid(table->de, (op == 001) ? | |
1422 | SECCLASS_DIR : SECCLASS_FILE, &tsid); | |
1423 | if (rc) { | |
1424 | /* Default to the well-defined sysctl SID. */ | |
1425 | tsid = SECINITSID_SYSCTL; | |
1426 | } | |
1427 | ||
1428 | /* The op values are "defined" in sysctl.c, thereby creating | |
1429 | * a bad coupling between this module and sysctl.c */ | |
1430 | if(op == 001) { | |
1431 | error = avc_has_perm(tsec->sid, tsid, | |
1432 | SECCLASS_DIR, DIR__SEARCH, NULL); | |
1433 | } else { | |
1434 | av = 0; | |
1435 | if (op & 004) | |
1436 | av |= FILE__READ; | |
1437 | if (op & 002) | |
1438 | av |= FILE__WRITE; | |
1439 | if (av) | |
1440 | error = avc_has_perm(tsec->sid, tsid, | |
1441 | SECCLASS_FILE, av, NULL); | |
1442 | } | |
1443 | ||
1444 | return error; | |
1445 | } | |
1446 | ||
1447 | static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) | |
1448 | { | |
1449 | int rc = 0; | |
1450 | ||
1451 | if (!sb) | |
1452 | return 0; | |
1453 | ||
1454 | switch (cmds) { | |
1455 | case Q_SYNC: | |
1456 | case Q_QUOTAON: | |
1457 | case Q_QUOTAOFF: | |
1458 | case Q_SETINFO: | |
1459 | case Q_SETQUOTA: | |
1460 | rc = superblock_has_perm(current, | |
1461 | sb, | |
1462 | FILESYSTEM__QUOTAMOD, NULL); | |
1463 | break; | |
1464 | case Q_GETFMT: | |
1465 | case Q_GETINFO: | |
1466 | case Q_GETQUOTA: | |
1467 | rc = superblock_has_perm(current, | |
1468 | sb, | |
1469 | FILESYSTEM__QUOTAGET, NULL); | |
1470 | break; | |
1471 | default: | |
1472 | rc = 0; /* let the kernel handle invalid cmds */ | |
1473 | break; | |
1474 | } | |
1475 | return rc; | |
1476 | } | |
1477 | ||
1478 | static int selinux_quota_on(struct dentry *dentry) | |
1479 | { | |
1480 | return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON); | |
1481 | } | |
1482 | ||
1483 | static int selinux_syslog(int type) | |
1484 | { | |
1485 | int rc; | |
1486 | ||
1487 | rc = secondary_ops->syslog(type); | |
1488 | if (rc) | |
1489 | return rc; | |
1490 | ||
1491 | switch (type) { | |
1492 | case 3: /* Read last kernel messages */ | |
1493 | case 10: /* Return size of the log buffer */ | |
1494 | rc = task_has_system(current, SYSTEM__SYSLOG_READ); | |
1495 | break; | |
1496 | case 6: /* Disable logging to console */ | |
1497 | case 7: /* Enable logging to console */ | |
1498 | case 8: /* Set level of messages printed to console */ | |
1499 | rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE); | |
1500 | break; | |
1501 | case 0: /* Close log */ | |
1502 | case 1: /* Open log */ | |
1503 | case 2: /* Read from log */ | |
1504 | case 4: /* Read/clear last kernel messages */ | |
1505 | case 5: /* Clear ring buffer */ | |
1506 | default: | |
1507 | rc = task_has_system(current, SYSTEM__SYSLOG_MOD); | |
1508 | break; | |
1509 | } | |
1510 | return rc; | |
1511 | } | |
1512 | ||
1513 | /* | |
1514 | * Check that a process has enough memory to allocate a new virtual | |
1515 | * mapping. 0 means there is enough memory for the allocation to | |
1516 | * succeed and -ENOMEM implies there is not. | |
1517 | * | |
1518 | * Note that secondary_ops->capable and task_has_perm_noaudit return 0 | |
1519 | * if the capability is granted, but __vm_enough_memory requires 1 if | |
1520 | * the capability is granted. | |
1521 | * | |
1522 | * Do not audit the selinux permission check, as this is applied to all | |
1523 | * processes that allocate mappings. | |
1524 | */ | |
1525 | static int selinux_vm_enough_memory(long pages) | |
1526 | { | |
1527 | int rc, cap_sys_admin = 0; | |
1528 | struct task_security_struct *tsec = current->security; | |
1529 | ||
1530 | rc = secondary_ops->capable(current, CAP_SYS_ADMIN); | |
1531 | if (rc == 0) | |
1532 | rc = avc_has_perm_noaudit(tsec->sid, tsec->sid, | |
1533 | SECCLASS_CAPABILITY, | |
1534 | CAP_TO_MASK(CAP_SYS_ADMIN), | |
1535 | NULL); | |
1536 | ||
1537 | if (rc == 0) | |
1538 | cap_sys_admin = 1; | |
1539 | ||
1540 | return __vm_enough_memory(pages, cap_sys_admin); | |
1541 | } | |
1542 | ||
1543 | /* binprm security operations */ | |
1544 | ||
1545 | static int selinux_bprm_alloc_security(struct linux_binprm *bprm) | |
1546 | { | |
1547 | struct bprm_security_struct *bsec; | |
1548 | ||
1549 | bsec = kmalloc(sizeof(struct bprm_security_struct), GFP_KERNEL); | |
1550 | if (!bsec) | |
1551 | return -ENOMEM; | |
1552 | ||
1553 | memset(bsec, 0, sizeof *bsec); | |
1554 | bsec->magic = SELINUX_MAGIC; | |
1555 | bsec->bprm = bprm; | |
1556 | bsec->sid = SECINITSID_UNLABELED; | |
1557 | bsec->set = 0; | |
1558 | ||
1559 | bprm->security = bsec; | |
1560 | return 0; | |
1561 | } | |
1562 | ||
1563 | static int selinux_bprm_set_security(struct linux_binprm *bprm) | |
1564 | { | |
1565 | struct task_security_struct *tsec; | |
1566 | struct inode *inode = bprm->file->f_dentry->d_inode; | |
1567 | struct inode_security_struct *isec; | |
1568 | struct bprm_security_struct *bsec; | |
1569 | u32 newsid; | |
1570 | struct avc_audit_data ad; | |
1571 | int rc; | |
1572 | ||
1573 | rc = secondary_ops->bprm_set_security(bprm); | |
1574 | if (rc) | |
1575 | return rc; | |
1576 | ||
1577 | bsec = bprm->security; | |
1578 | ||
1579 | if (bsec->set) | |
1580 | return 0; | |
1581 | ||
1582 | tsec = current->security; | |
1583 | isec = inode->i_security; | |
1584 | ||
1585 | /* Default to the current task SID. */ | |
1586 | bsec->sid = tsec->sid; | |
1587 | ||
1588 | /* Reset create SID on execve. */ | |
1589 | tsec->create_sid = 0; | |
1590 | ||
1591 | if (tsec->exec_sid) { | |
1592 | newsid = tsec->exec_sid; | |
1593 | /* Reset exec SID on execve. */ | |
1594 | tsec->exec_sid = 0; | |
1595 | } else { | |
1596 | /* Check for a default transition on this program. */ | |
1597 | rc = security_transition_sid(tsec->sid, isec->sid, | |
1598 | SECCLASS_PROCESS, &newsid); | |
1599 | if (rc) | |
1600 | return rc; | |
1601 | } | |
1602 | ||
1603 | AVC_AUDIT_DATA_INIT(&ad, FS); | |
1604 | ad.u.fs.mnt = bprm->file->f_vfsmnt; | |
1605 | ad.u.fs.dentry = bprm->file->f_dentry; | |
1606 | ||
1607 | if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) | |
1608 | newsid = tsec->sid; | |
1609 | ||
1610 | if (tsec->sid == newsid) { | |
1611 | rc = avc_has_perm(tsec->sid, isec->sid, | |
1612 | SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); | |
1613 | if (rc) | |
1614 | return rc; | |
1615 | } else { | |
1616 | /* Check permissions for the transition. */ | |
1617 | rc = avc_has_perm(tsec->sid, newsid, | |
1618 | SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); | |
1619 | if (rc) | |
1620 | return rc; | |
1621 | ||
1622 | rc = avc_has_perm(newsid, isec->sid, | |
1623 | SECCLASS_FILE, FILE__ENTRYPOINT, &ad); | |
1624 | if (rc) | |
1625 | return rc; | |
1626 | ||
1627 | /* Clear any possibly unsafe personality bits on exec: */ | |
1628 | current->personality &= ~PER_CLEAR_ON_SETID; | |
1629 | ||
1630 | /* Set the security field to the new SID. */ | |
1631 | bsec->sid = newsid; | |
1632 | } | |
1633 | ||
1634 | bsec->set = 1; | |
1635 | return 0; | |
1636 | } | |
1637 | ||
1638 | static int selinux_bprm_check_security (struct linux_binprm *bprm) | |
1639 | { | |
1640 | return secondary_ops->bprm_check_security(bprm); | |
1641 | } | |
1642 | ||
1643 | ||
1644 | static int selinux_bprm_secureexec (struct linux_binprm *bprm) | |
1645 | { | |
1646 | struct task_security_struct *tsec = current->security; | |
1647 | int atsecure = 0; | |
1648 | ||
1649 | if (tsec->osid != tsec->sid) { | |
1650 | /* Enable secure mode for SIDs transitions unless | |
1651 | the noatsecure permission is granted between | |
1652 | the two SIDs, i.e. ahp returns 0. */ | |
1653 | atsecure = avc_has_perm(tsec->osid, tsec->sid, | |
1654 | SECCLASS_PROCESS, | |
1655 | PROCESS__NOATSECURE, NULL); | |
1656 | } | |
1657 | ||
1658 | return (atsecure || secondary_ops->bprm_secureexec(bprm)); | |
1659 | } | |
1660 | ||
1661 | static void selinux_bprm_free_security(struct linux_binprm *bprm) | |
1662 | { | |
9a5f04bf | 1663 | kfree(bprm->security); |
1da177e4 | 1664 | bprm->security = NULL; |
1da177e4 LT |
1665 | } |
1666 | ||
1667 | extern struct vfsmount *selinuxfs_mount; | |
1668 | extern struct dentry *selinux_null; | |
1669 | ||
1670 | /* Derived from fs/exec.c:flush_old_files. */ | |
1671 | static inline void flush_unauthorized_files(struct files_struct * files) | |
1672 | { | |
1673 | struct avc_audit_data ad; | |
1674 | struct file *file, *devnull = NULL; | |
1675 | struct tty_struct *tty = current->signal->tty; | |
1676 | long j = -1; | |
1677 | ||
1678 | if (tty) { | |
1679 | file_list_lock(); | |
1680 | file = list_entry(tty->tty_files.next, typeof(*file), f_list); | |
1681 | if (file) { | |
1682 | /* Revalidate access to controlling tty. | |
1683 | Use inode_has_perm on the tty inode directly rather | |
1684 | than using file_has_perm, as this particular open | |
1685 | file may belong to another process and we are only | |
1686 | interested in the inode-based check here. */ | |
1687 | struct inode *inode = file->f_dentry->d_inode; | |
1688 | if (inode_has_perm(current, inode, | |
1689 | FILE__READ | FILE__WRITE, NULL)) { | |
1690 | /* Reset controlling tty. */ | |
1691 | current->signal->tty = NULL; | |
1692 | current->signal->tty_old_pgrp = 0; | |
1693 | } | |
1694 | } | |
1695 | file_list_unlock(); | |
1696 | } | |
1697 | ||
1698 | /* Revalidate access to inherited open files. */ | |
1699 | ||
1700 | AVC_AUDIT_DATA_INIT(&ad,FS); | |
1701 | ||
1702 | spin_lock(&files->file_lock); | |
1703 | for (;;) { | |
1704 | unsigned long set, i; | |
1705 | int fd; | |
1706 | ||
1707 | j++; | |
1708 | i = j * __NFDBITS; | |
1709 | if (i >= files->max_fds || i >= files->max_fdset) | |
1710 | break; | |
1711 | set = files->open_fds->fds_bits[j]; | |
1712 | if (!set) | |
1713 | continue; | |
1714 | spin_unlock(&files->file_lock); | |
1715 | for ( ; set ; i++,set >>= 1) { | |
1716 | if (set & 1) { | |
1717 | file = fget(i); | |
1718 | if (!file) | |
1719 | continue; | |
1720 | if (file_has_perm(current, | |
1721 | file, | |
1722 | file_to_av(file))) { | |
1723 | sys_close(i); | |
1724 | fd = get_unused_fd(); | |
1725 | if (fd != i) { | |
1726 | if (fd >= 0) | |
1727 | put_unused_fd(fd); | |
1728 | fput(file); | |
1729 | continue; | |
1730 | } | |
1731 | if (devnull) { | |
1732 | atomic_inc(&devnull->f_count); | |
1733 | } else { | |
1734 | devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR); | |
1735 | if (!devnull) { | |
1736 | put_unused_fd(fd); | |
1737 | fput(file); | |
1738 | continue; | |
1739 | } | |
1740 | } | |
1741 | fd_install(fd, devnull); | |
1742 | } | |
1743 | fput(file); | |
1744 | } | |
1745 | } | |
1746 | spin_lock(&files->file_lock); | |
1747 | ||
1748 | } | |
1749 | spin_unlock(&files->file_lock); | |
1750 | } | |
1751 | ||
1752 | static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) | |
1753 | { | |
1754 | struct task_security_struct *tsec; | |
1755 | struct bprm_security_struct *bsec; | |
1756 | u32 sid; | |
1757 | int rc; | |
1758 | ||
1759 | secondary_ops->bprm_apply_creds(bprm, unsafe); | |
1760 | ||
1761 | tsec = current->security; | |
1762 | ||
1763 | bsec = bprm->security; | |
1764 | sid = bsec->sid; | |
1765 | ||
1766 | tsec->osid = tsec->sid; | |
1767 | bsec->unsafe = 0; | |
1768 | if (tsec->sid != sid) { | |
1769 | /* Check for shared state. If not ok, leave SID | |
1770 | unchanged and kill. */ | |
1771 | if (unsafe & LSM_UNSAFE_SHARE) { | |
1772 | rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS, | |
1773 | PROCESS__SHARE, NULL); | |
1774 | if (rc) { | |
1775 | bsec->unsafe = 1; | |
1776 | return; | |
1777 | } | |
1778 | } | |
1779 | ||
1780 | /* Check for ptracing, and update the task SID if ok. | |
1781 | Otherwise, leave SID unchanged and kill. */ | |
1782 | if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { | |
1783 | rc = avc_has_perm(tsec->ptrace_sid, sid, | |
1784 | SECCLASS_PROCESS, PROCESS__PTRACE, | |
1785 | NULL); | |
1786 | if (rc) { | |
1787 | bsec->unsafe = 1; | |
1788 | return; | |
1789 | } | |
1790 | } | |
1791 | tsec->sid = sid; | |
1792 | } | |
1793 | } | |
1794 | ||
1795 | /* | |
1796 | * called after apply_creds without the task lock held | |
1797 | */ | |
1798 | static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm) | |
1799 | { | |
1800 | struct task_security_struct *tsec; | |
1801 | struct rlimit *rlim, *initrlim; | |
1802 | struct itimerval itimer; | |
1803 | struct bprm_security_struct *bsec; | |
1804 | int rc, i; | |
1805 | ||
1806 | tsec = current->security; | |
1807 | bsec = bprm->security; | |
1808 | ||
1809 | if (bsec->unsafe) { | |
1810 | force_sig_specific(SIGKILL, current); | |
1811 | return; | |
1812 | } | |
1813 | if (tsec->osid == tsec->sid) | |
1814 | return; | |
1815 | ||
1816 | /* Close files for which the new task SID is not authorized. */ | |
1817 | flush_unauthorized_files(current->files); | |
1818 | ||
1819 | /* Check whether the new SID can inherit signal state | |
1820 | from the old SID. If not, clear itimers to avoid | |
1821 | subsequent signal generation and flush and unblock | |
1822 | signals. This must occur _after_ the task SID has | |
1823 | been updated so that any kill done after the flush | |
1824 | will be checked against the new SID. */ | |
1825 | rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS, | |
1826 | PROCESS__SIGINH, NULL); | |
1827 | if (rc) { | |
1828 | memset(&itimer, 0, sizeof itimer); | |
1829 | for (i = 0; i < 3; i++) | |
1830 | do_setitimer(i, &itimer, NULL); | |
1831 | flush_signals(current); | |
1832 | spin_lock_irq(¤t->sighand->siglock); | |
1833 | flush_signal_handlers(current, 1); | |
1834 | sigemptyset(¤t->blocked); | |
1835 | recalc_sigpending(); | |
1836 | spin_unlock_irq(¤t->sighand->siglock); | |
1837 | } | |
1838 | ||
1839 | /* Check whether the new SID can inherit resource limits | |
1840 | from the old SID. If not, reset all soft limits to | |
1841 | the lower of the current task's hard limit and the init | |
1842 | task's soft limit. Note that the setting of hard limits | |
1843 | (even to lower them) can be controlled by the setrlimit | |
1844 | check. The inclusion of the init task's soft limit into | |
1845 | the computation is to avoid resetting soft limits higher | |
1846 | than the default soft limit for cases where the default | |
1847 | is lower than the hard limit, e.g. RLIMIT_CORE or | |
1848 | RLIMIT_STACK.*/ | |
1849 | rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS, | |
1850 | PROCESS__RLIMITINH, NULL); | |
1851 | if (rc) { | |
1852 | for (i = 0; i < RLIM_NLIMITS; i++) { | |
1853 | rlim = current->signal->rlim + i; | |
1854 | initrlim = init_task.signal->rlim+i; | |
1855 | rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur); | |
1856 | } | |
1857 | if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) { | |
1858 | /* | |
1859 | * This will cause RLIMIT_CPU calculations | |
1860 | * to be refigured. | |
1861 | */ | |
1862 | current->it_prof_expires = jiffies_to_cputime(1); | |
1863 | } | |
1864 | } | |
1865 | ||
1866 | /* Wake up the parent if it is waiting so that it can | |
1867 | recheck wait permission to the new task SID. */ | |
1868 | wake_up_interruptible(¤t->parent->signal->wait_chldexit); | |
1869 | } | |
1870 | ||
1871 | /* superblock security operations */ | |
1872 | ||
1873 | static int selinux_sb_alloc_security(struct super_block *sb) | |
1874 | { | |
1875 | return superblock_alloc_security(sb); | |
1876 | } | |
1877 | ||
1878 | static void selinux_sb_free_security(struct super_block *sb) | |
1879 | { | |
1880 | superblock_free_security(sb); | |
1881 | } | |
1882 | ||
1883 | static inline int match_prefix(char *prefix, int plen, char *option, int olen) | |
1884 | { | |
1885 | if (plen > olen) | |
1886 | return 0; | |
1887 | ||
1888 | return !memcmp(prefix, option, plen); | |
1889 | } | |
1890 | ||
1891 | static inline int selinux_option(char *option, int len) | |
1892 | { | |
1893 | return (match_prefix("context=", sizeof("context=")-1, option, len) || | |
1894 | match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) || | |
1895 | match_prefix("defcontext=", sizeof("defcontext=")-1, option, len)); | |
1896 | } | |
1897 | ||
1898 | static inline void take_option(char **to, char *from, int *first, int len) | |
1899 | { | |
1900 | if (!*first) { | |
1901 | **to = ','; | |
1902 | *to += 1; | |
1903 | } | |
1904 | else | |
1905 | *first = 0; | |
1906 | memcpy(*to, from, len); | |
1907 | *to += len; | |
1908 | } | |
1909 | ||
1910 | static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy) | |
1911 | { | |
1912 | int fnosec, fsec, rc = 0; | |
1913 | char *in_save, *in_curr, *in_end; | |
1914 | char *sec_curr, *nosec_save, *nosec; | |
1915 | ||
1916 | in_curr = orig; | |
1917 | sec_curr = copy; | |
1918 | ||
1919 | /* Binary mount data: just copy */ | |
1920 | if (type->fs_flags & FS_BINARY_MOUNTDATA) { | |
1921 | copy_page(sec_curr, in_curr); | |
1922 | goto out; | |
1923 | } | |
1924 | ||
1925 | nosec = (char *)get_zeroed_page(GFP_KERNEL); | |
1926 | if (!nosec) { | |
1927 | rc = -ENOMEM; | |
1928 | goto out; | |
1929 | } | |
1930 | ||
1931 | nosec_save = nosec; | |
1932 | fnosec = fsec = 1; | |
1933 | in_save = in_end = orig; | |
1934 | ||
1935 | do { | |
1936 | if (*in_end == ',' || *in_end == '\0') { | |
1937 | int len = in_end - in_curr; | |
1938 | ||
1939 | if (selinux_option(in_curr, len)) | |
1940 | take_option(&sec_curr, in_curr, &fsec, len); | |
1941 | else | |
1942 | take_option(&nosec, in_curr, &fnosec, len); | |
1943 | ||
1944 | in_curr = in_end + 1; | |
1945 | } | |
1946 | } while (*in_end++); | |
1947 | ||
6931dfc9 | 1948 | strcpy(in_save, nosec_save); |
da3caa20 | 1949 | free_page((unsigned long)nosec_save); |
1da177e4 LT |
1950 | out: |
1951 | return rc; | |
1952 | } | |
1953 | ||
1954 | static int selinux_sb_kern_mount(struct super_block *sb, void *data) | |
1955 | { | |
1956 | struct avc_audit_data ad; | |
1957 | int rc; | |
1958 | ||
1959 | rc = superblock_doinit(sb, data); | |
1960 | if (rc) | |
1961 | return rc; | |
1962 | ||
1963 | AVC_AUDIT_DATA_INIT(&ad,FS); | |
1964 | ad.u.fs.dentry = sb->s_root; | |
1965 | return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad); | |
1966 | } | |
1967 | ||
1968 | static int selinux_sb_statfs(struct super_block *sb) | |
1969 | { | |
1970 | struct avc_audit_data ad; | |
1971 | ||
1972 | AVC_AUDIT_DATA_INIT(&ad,FS); | |
1973 | ad.u.fs.dentry = sb->s_root; | |
1974 | return superblock_has_perm(current, sb, FILESYSTEM__GETATTR, &ad); | |
1975 | } | |
1976 | ||
1977 | static int selinux_mount(char * dev_name, | |
1978 | struct nameidata *nd, | |
1979 | char * type, | |
1980 | unsigned long flags, | |
1981 | void * data) | |
1982 | { | |
1983 | int rc; | |
1984 | ||
1985 | rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data); | |
1986 | if (rc) | |
1987 | return rc; | |
1988 | ||
1989 | if (flags & MS_REMOUNT) | |
1990 | return superblock_has_perm(current, nd->mnt->mnt_sb, | |
1991 | FILESYSTEM__REMOUNT, NULL); | |
1992 | else | |
1993 | return dentry_has_perm(current, nd->mnt, nd->dentry, | |
1994 | FILE__MOUNTON); | |
1995 | } | |
1996 | ||
1997 | static int selinux_umount(struct vfsmount *mnt, int flags) | |
1998 | { | |
1999 | int rc; | |
2000 | ||
2001 | rc = secondary_ops->sb_umount(mnt, flags); | |
2002 | if (rc) | |
2003 | return rc; | |
2004 | ||
2005 | return superblock_has_perm(current,mnt->mnt_sb, | |
2006 | FILESYSTEM__UNMOUNT,NULL); | |
2007 | } | |
2008 | ||
2009 | /* inode security operations */ | |
2010 | ||
2011 | static int selinux_inode_alloc_security(struct inode *inode) | |
2012 | { | |
2013 | return inode_alloc_security(inode); | |
2014 | } | |
2015 | ||
2016 | static void selinux_inode_free_security(struct inode *inode) | |
2017 | { | |
2018 | inode_free_security(inode); | |
2019 | } | |
2020 | ||
2021 | static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask) | |
2022 | { | |
2023 | return may_create(dir, dentry, SECCLASS_FILE); | |
2024 | } | |
2025 | ||
2026 | static void selinux_inode_post_create(struct inode *dir, struct dentry *dentry, int mask) | |
2027 | { | |
2028 | post_create(dir, dentry); | |
2029 | } | |
2030 | ||
2031 | static 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 | ||
2041 | static void selinux_inode_post_link(struct dentry *old_dentry, struct inode *inode, struct dentry *new_dentry) | |
2042 | { | |
2043 | return; | |
2044 | } | |
2045 | ||
2046 | static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) | |
2047 | { | |
2048 | int rc; | |
2049 | ||
2050 | rc = secondary_ops->inode_unlink(dir, dentry); | |
2051 | if (rc) | |
2052 | return rc; | |
2053 | return may_link(dir, dentry, MAY_UNLINK); | |
2054 | } | |
2055 | ||
2056 | static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) | |
2057 | { | |
2058 | return may_create(dir, dentry, SECCLASS_LNK_FILE); | |
2059 | } | |
2060 | ||
2061 | static void selinux_inode_post_symlink(struct inode *dir, struct dentry *dentry, const char *name) | |
2062 | { | |
2063 | post_create(dir, dentry); | |
2064 | } | |
2065 | ||
2066 | static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask) | |
2067 | { | |
2068 | return may_create(dir, dentry, SECCLASS_DIR); | |
2069 | } | |
2070 | ||
2071 | static void selinux_inode_post_mkdir(struct inode *dir, struct dentry *dentry, int mask) | |
2072 | { | |
2073 | post_create(dir, dentry); | |
2074 | } | |
2075 | ||
2076 | static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) | |
2077 | { | |
2078 | return may_link(dir, dentry, MAY_RMDIR); | |
2079 | } | |
2080 | ||
2081 | static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
2082 | { | |
2083 | int rc; | |
2084 | ||
2085 | rc = secondary_ops->inode_mknod(dir, dentry, mode, dev); | |
2086 | if (rc) | |
2087 | return rc; | |
2088 | ||
2089 | return may_create(dir, dentry, inode_mode_to_security_class(mode)); | |
2090 | } | |
2091 | ||
2092 | static void selinux_inode_post_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
2093 | { | |
2094 | post_create(dir, dentry); | |
2095 | } | |
2096 | ||
2097 | static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, | |
2098 | struct inode *new_inode, struct dentry *new_dentry) | |
2099 | { | |
2100 | return may_rename(old_inode, old_dentry, new_inode, new_dentry); | |
2101 | } | |
2102 | ||
2103 | static void selinux_inode_post_rename(struct inode *old_inode, struct dentry *old_dentry, | |
2104 | struct inode *new_inode, struct dentry *new_dentry) | |
2105 | { | |
2106 | return; | |
2107 | } | |
2108 | ||
2109 | static int selinux_inode_readlink(struct dentry *dentry) | |
2110 | { | |
2111 | return dentry_has_perm(current, NULL, dentry, FILE__READ); | |
2112 | } | |
2113 | ||
2114 | static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata) | |
2115 | { | |
2116 | int rc; | |
2117 | ||
2118 | rc = secondary_ops->inode_follow_link(dentry,nameidata); | |
2119 | if (rc) | |
2120 | return rc; | |
2121 | return dentry_has_perm(current, NULL, dentry, FILE__READ); | |
2122 | } | |
2123 | ||
2124 | static int selinux_inode_permission(struct inode *inode, int mask, | |
2125 | struct nameidata *nd) | |
2126 | { | |
2127 | int rc; | |
2128 | ||
2129 | rc = secondary_ops->inode_permission(inode, mask, nd); | |
2130 | if (rc) | |
2131 | return rc; | |
2132 | ||
2133 | if (!mask) { | |
2134 | /* No permission to check. Existence test. */ | |
2135 | return 0; | |
2136 | } | |
2137 | ||
2138 | return inode_has_perm(current, inode, | |
2139 | file_mask_to_av(inode->i_mode, mask), NULL); | |
2140 | } | |
2141 | ||
2142 | static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) | |
2143 | { | |
2144 | int rc; | |
2145 | ||
2146 | rc = secondary_ops->inode_setattr(dentry, iattr); | |
2147 | if (rc) | |
2148 | return rc; | |
2149 | ||
2150 | if (iattr->ia_valid & ATTR_FORCE) | |
2151 | return 0; | |
2152 | ||
2153 | if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | | |
2154 | ATTR_ATIME_SET | ATTR_MTIME_SET)) | |
2155 | return dentry_has_perm(current, NULL, dentry, FILE__SETATTR); | |
2156 | ||
2157 | return dentry_has_perm(current, NULL, dentry, FILE__WRITE); | |
2158 | } | |
2159 | ||
2160 | static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) | |
2161 | { | |
2162 | return dentry_has_perm(current, mnt, dentry, FILE__GETATTR); | |
2163 | } | |
2164 | ||
2165 | static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags) | |
2166 | { | |
2167 | struct task_security_struct *tsec = current->security; | |
2168 | struct inode *inode = dentry->d_inode; | |
2169 | struct inode_security_struct *isec = inode->i_security; | |
2170 | struct superblock_security_struct *sbsec; | |
2171 | struct avc_audit_data ad; | |
2172 | u32 newsid; | |
2173 | int rc = 0; | |
2174 | ||
2175 | if (strcmp(name, XATTR_NAME_SELINUX)) { | |
2176 | if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
2177 | sizeof XATTR_SECURITY_PREFIX - 1) && | |
2178 | !capable(CAP_SYS_ADMIN)) { | |
2179 | /* A different attribute in the security namespace. | |
2180 | Restrict to administrator. */ | |
2181 | return -EPERM; | |
2182 | } | |
2183 | ||
2184 | /* Not an attribute we recognize, so just check the | |
2185 | ordinary setattr permission. */ | |
2186 | return dentry_has_perm(current, NULL, dentry, FILE__SETATTR); | |
2187 | } | |
2188 | ||
2189 | sbsec = inode->i_sb->s_security; | |
2190 | if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT) | |
2191 | return -EOPNOTSUPP; | |
2192 | ||
2193 | if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) | |
2194 | return -EPERM; | |
2195 | ||
2196 | AVC_AUDIT_DATA_INIT(&ad,FS); | |
2197 | ad.u.fs.dentry = dentry; | |
2198 | ||
2199 | rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, | |
2200 | FILE__RELABELFROM, &ad); | |
2201 | if (rc) | |
2202 | return rc; | |
2203 | ||
2204 | rc = security_context_to_sid(value, size, &newsid); | |
2205 | if (rc) | |
2206 | return rc; | |
2207 | ||
2208 | rc = avc_has_perm(tsec->sid, newsid, isec->sclass, | |
2209 | FILE__RELABELTO, &ad); | |
2210 | if (rc) | |
2211 | return rc; | |
2212 | ||
2213 | rc = security_validate_transition(isec->sid, newsid, tsec->sid, | |
2214 | isec->sclass); | |
2215 | if (rc) | |
2216 | return rc; | |
2217 | ||
2218 | return avc_has_perm(newsid, | |
2219 | sbsec->sid, | |
2220 | SECCLASS_FILESYSTEM, | |
2221 | FILESYSTEM__ASSOCIATE, | |
2222 | &ad); | |
2223 | } | |
2224 | ||
2225 | static void selinux_inode_post_setxattr(struct dentry *dentry, char *name, | |
2226 | void *value, size_t size, int flags) | |
2227 | { | |
2228 | struct inode *inode = dentry->d_inode; | |
2229 | struct inode_security_struct *isec = inode->i_security; | |
2230 | u32 newsid; | |
2231 | int rc; | |
2232 | ||
2233 | if (strcmp(name, XATTR_NAME_SELINUX)) { | |
2234 | /* Not an attribute we recognize, so nothing to do. */ | |
2235 | return; | |
2236 | } | |
2237 | ||
2238 | rc = security_context_to_sid(value, size, &newsid); | |
2239 | if (rc) { | |
2240 | printk(KERN_WARNING "%s: unable to obtain SID for context " | |
2241 | "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc); | |
2242 | return; | |
2243 | } | |
2244 | ||
2245 | isec->sid = newsid; | |
2246 | return; | |
2247 | } | |
2248 | ||
2249 | static int selinux_inode_getxattr (struct dentry *dentry, char *name) | |
2250 | { | |
2251 | struct inode *inode = dentry->d_inode; | |
2252 | struct superblock_security_struct *sbsec = inode->i_sb->s_security; | |
2253 | ||
2254 | if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT) | |
2255 | return -EOPNOTSUPP; | |
2256 | ||
2257 | return dentry_has_perm(current, NULL, dentry, FILE__GETATTR); | |
2258 | } | |
2259 | ||
2260 | static int selinux_inode_listxattr (struct dentry *dentry) | |
2261 | { | |
2262 | return dentry_has_perm(current, NULL, dentry, FILE__GETATTR); | |
2263 | } | |
2264 | ||
2265 | static int selinux_inode_removexattr (struct dentry *dentry, char *name) | |
2266 | { | |
2267 | if (strcmp(name, XATTR_NAME_SELINUX)) { | |
2268 | if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
2269 | sizeof XATTR_SECURITY_PREFIX - 1) && | |
2270 | !capable(CAP_SYS_ADMIN)) { | |
2271 | /* A different attribute in the security namespace. | |
2272 | Restrict to administrator. */ | |
2273 | return -EPERM; | |
2274 | } | |
2275 | ||
2276 | /* Not an attribute we recognize, so just check the | |
2277 | ordinary setattr permission. Might want a separate | |
2278 | permission for removexattr. */ | |
2279 | return dentry_has_perm(current, NULL, dentry, FILE__SETATTR); | |
2280 | } | |
2281 | ||
2282 | /* No one is allowed to remove a SELinux security label. | |
2283 | You can change the label, but all data must be labeled. */ | |
2284 | return -EACCES; | |
2285 | } | |
2286 | ||
2287 | static int selinux_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size) | |
2288 | { | |
2289 | struct inode_security_struct *isec = inode->i_security; | |
2290 | char *context; | |
2291 | unsigned len; | |
2292 | int rc; | |
2293 | ||
2294 | /* Permission check handled by selinux_inode_getxattr hook.*/ | |
2295 | ||
2296 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) | |
2297 | return -EOPNOTSUPP; | |
2298 | ||
2299 | rc = security_sid_to_context(isec->sid, &context, &len); | |
2300 | if (rc) | |
2301 | return rc; | |
2302 | ||
2303 | if (!buffer || !size) { | |
2304 | kfree(context); | |
2305 | return len; | |
2306 | } | |
2307 | if (size < len) { | |
2308 | kfree(context); | |
2309 | return -ERANGE; | |
2310 | } | |
2311 | memcpy(buffer, context, len); | |
2312 | kfree(context); | |
2313 | return len; | |
2314 | } | |
2315 | ||
2316 | static int selinux_inode_setsecurity(struct inode *inode, const char *name, | |
2317 | const void *value, size_t size, int flags) | |
2318 | { | |
2319 | struct inode_security_struct *isec = inode->i_security; | |
2320 | u32 newsid; | |
2321 | int rc; | |
2322 | ||
2323 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) | |
2324 | return -EOPNOTSUPP; | |
2325 | ||
2326 | if (!value || !size) | |
2327 | return -EACCES; | |
2328 | ||
2329 | rc = security_context_to_sid((void*)value, size, &newsid); | |
2330 | if (rc) | |
2331 | return rc; | |
2332 | ||
2333 | isec->sid = newsid; | |
2334 | return 0; | |
2335 | } | |
2336 | ||
2337 | static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) | |
2338 | { | |
2339 | const int len = sizeof(XATTR_NAME_SELINUX); | |
2340 | if (buffer && len <= buffer_size) | |
2341 | memcpy(buffer, XATTR_NAME_SELINUX, len); | |
2342 | return len; | |
2343 | } | |
2344 | ||
2345 | /* file security operations */ | |
2346 | ||
2347 | static int selinux_file_permission(struct file *file, int mask) | |
2348 | { | |
2349 | struct inode *inode = file->f_dentry->d_inode; | |
2350 | ||
2351 | if (!mask) { | |
2352 | /* No permission to check. Existence test. */ | |
2353 | return 0; | |
2354 | } | |
2355 | ||
2356 | /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ | |
2357 | if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) | |
2358 | mask |= MAY_APPEND; | |
2359 | ||
2360 | return file_has_perm(current, file, | |
2361 | file_mask_to_av(inode->i_mode, mask)); | |
2362 | } | |
2363 | ||
2364 | static int selinux_file_alloc_security(struct file *file) | |
2365 | { | |
2366 | return file_alloc_security(file); | |
2367 | } | |
2368 | ||
2369 | static void selinux_file_free_security(struct file *file) | |
2370 | { | |
2371 | file_free_security(file); | |
2372 | } | |
2373 | ||
2374 | static int selinux_file_ioctl(struct file *file, unsigned int cmd, | |
2375 | unsigned long arg) | |
2376 | { | |
2377 | int error = 0; | |
2378 | ||
2379 | switch (cmd) { | |
2380 | case FIONREAD: | |
2381 | /* fall through */ | |
2382 | case FIBMAP: | |
2383 | /* fall through */ | |
2384 | case FIGETBSZ: | |
2385 | /* fall through */ | |
2386 | case EXT2_IOC_GETFLAGS: | |
2387 | /* fall through */ | |
2388 | case EXT2_IOC_GETVERSION: | |
2389 | error = file_has_perm(current, file, FILE__GETATTR); | |
2390 | break; | |
2391 | ||
2392 | case EXT2_IOC_SETFLAGS: | |
2393 | /* fall through */ | |
2394 | case EXT2_IOC_SETVERSION: | |
2395 | error = file_has_perm(current, file, FILE__SETATTR); | |
2396 | break; | |
2397 | ||
2398 | /* sys_ioctl() checks */ | |
2399 | case FIONBIO: | |
2400 | /* fall through */ | |
2401 | case FIOASYNC: | |
2402 | error = file_has_perm(current, file, 0); | |
2403 | break; | |
2404 | ||
2405 | case KDSKBENT: | |
2406 | case KDSKBSENT: | |
2407 | error = task_has_capability(current,CAP_SYS_TTY_CONFIG); | |
2408 | break; | |
2409 | ||
2410 | /* default case assumes that the command will go | |
2411 | * to the file's ioctl() function. | |
2412 | */ | |
2413 | default: | |
2414 | error = file_has_perm(current, file, FILE__IOCTL); | |
2415 | ||
2416 | } | |
2417 | return error; | |
2418 | } | |
2419 | ||
2420 | static int file_map_prot_check(struct file *file, unsigned long prot, int shared) | |
2421 | { | |
2422 | #ifndef CONFIG_PPC32 | |
2423 | if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) { | |
2424 | /* | |
2425 | * We are making executable an anonymous mapping or a | |
2426 | * private file mapping that will also be writable. | |
2427 | * This has an additional check. | |
2428 | */ | |
2429 | int rc = task_has_perm(current, current, PROCESS__EXECMEM); | |
2430 | if (rc) | |
2431 | return rc; | |
2432 | } | |
2433 | #endif | |
2434 | ||
2435 | if (file) { | |
2436 | /* read access is always possible with a mapping */ | |
2437 | u32 av = FILE__READ; | |
2438 | ||
2439 | /* write access only matters if the mapping is shared */ | |
2440 | if (shared && (prot & PROT_WRITE)) | |
2441 | av |= FILE__WRITE; | |
2442 | ||
2443 | if (prot & PROT_EXEC) | |
2444 | av |= FILE__EXECUTE; | |
2445 | ||
2446 | return file_has_perm(current, file, av); | |
2447 | } | |
2448 | return 0; | |
2449 | } | |
2450 | ||
2451 | static int selinux_file_mmap(struct file *file, unsigned long reqprot, | |
2452 | unsigned long prot, unsigned long flags) | |
2453 | { | |
2454 | int rc; | |
2455 | ||
2456 | rc = secondary_ops->file_mmap(file, reqprot, prot, flags); | |
2457 | if (rc) | |
2458 | return rc; | |
2459 | ||
2460 | if (selinux_checkreqprot) | |
2461 | prot = reqprot; | |
2462 | ||
2463 | return file_map_prot_check(file, prot, | |
2464 | (flags & MAP_TYPE) == MAP_SHARED); | |
2465 | } | |
2466 | ||
2467 | static int selinux_file_mprotect(struct vm_area_struct *vma, | |
2468 | unsigned long reqprot, | |
2469 | unsigned long prot) | |
2470 | { | |
2471 | int rc; | |
2472 | ||
2473 | rc = secondary_ops->file_mprotect(vma, reqprot, prot); | |
2474 | if (rc) | |
2475 | return rc; | |
2476 | ||
2477 | if (selinux_checkreqprot) | |
2478 | prot = reqprot; | |
2479 | ||
2480 | #ifndef CONFIG_PPC32 |