Commit | Line | Data |
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fe7752ba DW |
1 | /* auditfilter.c -- filtering of audit events |
2 | * | |
3 | * Copyright 2003-2004 Red Hat, Inc. | |
4 | * Copyright 2005 Hewlett-Packard Development Company, L.P. | |
5 | * Copyright 2005 IBM Corporation | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
20 | */ | |
21 | ||
22 | #include <linux/kernel.h> | |
23 | #include <linux/audit.h> | |
24 | #include <linux/kthread.h> | |
f368c07d AG |
25 | #include <linux/mutex.h> |
26 | #include <linux/fs.h> | |
27 | #include <linux/namei.h> | |
fe7752ba | 28 | #include <linux/netlink.h> |
f368c07d AG |
29 | #include <linux/sched.h> |
30 | #include <linux/inotify.h> | |
3dc7e315 | 31 | #include <linux/selinux.h> |
fe7752ba DW |
32 | #include "audit.h" |
33 | ||
f368c07d AG |
34 | /* |
35 | * Locking model: | |
36 | * | |
37 | * audit_filter_mutex: | |
38 | * Synchronizes writes and blocking reads of audit's filterlist | |
39 | * data. Rcu is used to traverse the filterlist and access | |
40 | * contents of structs audit_entry, audit_watch and opaque | |
41 | * selinux rules during filtering. If modified, these structures | |
42 | * must be copied and replace their counterparts in the filterlist. | |
43 | * An audit_parent struct is not accessed during filtering, so may | |
44 | * be written directly provided audit_filter_mutex is held. | |
45 | */ | |
46 | ||
47 | /* | |
48 | * Reference counting: | |
49 | * | |
50 | * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED | |
51 | * event. Each audit_watch holds a reference to its associated parent. | |
52 | * | |
53 | * audit_watch: if added to lists, lifetime is from audit_init_watch() to | |
54 | * audit_remove_watch(). Additionally, an audit_watch may exist | |
55 | * temporarily to assist in searching existing filter data. Each | |
56 | * audit_krule holds a reference to its associated watch. | |
57 | */ | |
58 | ||
59 | struct audit_parent { | |
60 | struct list_head ilist; /* entry in inotify registration list */ | |
61 | struct list_head watches; /* associated watches */ | |
62 | struct inotify_watch wdata; /* inotify watch data */ | |
63 | unsigned flags; /* status flags */ | |
64 | }; | |
65 | ||
66 | /* | |
67 | * audit_parent status flags: | |
68 | * | |
69 | * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to | |
70 | * a filesystem event to ensure we're adding audit watches to a valid parent. | |
71 | * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot | |
72 | * receive them while we have nameidata, but must be used for IN_MOVE_SELF which | |
73 | * we can receive while holding nameidata. | |
74 | */ | |
75 | #define AUDIT_PARENT_INVALID 0x001 | |
76 | ||
77 | /* Audit filter lists, defined in <linux/audit.h> */ | |
fe7752ba DW |
78 | struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { |
79 | LIST_HEAD_INIT(audit_filter_list[0]), | |
80 | LIST_HEAD_INIT(audit_filter_list[1]), | |
81 | LIST_HEAD_INIT(audit_filter_list[2]), | |
82 | LIST_HEAD_INIT(audit_filter_list[3]), | |
83 | LIST_HEAD_INIT(audit_filter_list[4]), | |
84 | LIST_HEAD_INIT(audit_filter_list[5]), | |
85 | #if AUDIT_NR_FILTERS != 6 | |
86 | #error Fix audit_filter_list initialiser | |
87 | #endif | |
88 | }; | |
89 | ||
f368c07d AG |
90 | static DEFINE_MUTEX(audit_filter_mutex); |
91 | ||
92 | /* Inotify handle */ | |
93 | extern struct inotify_handle *audit_ih; | |
94 | ||
95 | /* Inotify events we care about. */ | |
96 | #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF | |
97 | ||
98 | void audit_free_parent(struct inotify_watch *i_watch) | |
99 | { | |
100 | struct audit_parent *parent; | |
101 | ||
102 | parent = container_of(i_watch, struct audit_parent, wdata); | |
103 | WARN_ON(!list_empty(&parent->watches)); | |
104 | kfree(parent); | |
105 | } | |
106 | ||
107 | static inline void audit_get_watch(struct audit_watch *watch) | |
108 | { | |
109 | atomic_inc(&watch->count); | |
110 | } | |
111 | ||
112 | static void audit_put_watch(struct audit_watch *watch) | |
113 | { | |
114 | if (atomic_dec_and_test(&watch->count)) { | |
115 | WARN_ON(watch->parent); | |
116 | WARN_ON(!list_empty(&watch->rules)); | |
117 | kfree(watch->path); | |
118 | kfree(watch); | |
119 | } | |
120 | } | |
121 | ||
122 | static void audit_remove_watch(struct audit_watch *watch) | |
123 | { | |
124 | list_del(&watch->wlist); | |
125 | put_inotify_watch(&watch->parent->wdata); | |
126 | watch->parent = NULL; | |
127 | audit_put_watch(watch); /* match initial get */ | |
128 | } | |
129 | ||
93315ed6 | 130 | static inline void audit_free_rule(struct audit_entry *e) |
fe7752ba | 131 | { |
3dc7e315 | 132 | int i; |
f368c07d AG |
133 | |
134 | /* some rules don't have associated watches */ | |
135 | if (e->rule.watch) | |
136 | audit_put_watch(e->rule.watch); | |
3dc7e315 DG |
137 | if (e->rule.fields) |
138 | for (i = 0; i < e->rule.field_count; i++) { | |
139 | struct audit_field *f = &e->rule.fields[i]; | |
140 | kfree(f->se_str); | |
141 | selinux_audit_rule_free(f->se_rule); | |
142 | } | |
93315ed6 AG |
143 | kfree(e->rule.fields); |
144 | kfree(e); | |
145 | } | |
146 | ||
147 | static inline void audit_free_rule_rcu(struct rcu_head *head) | |
148 | { | |
149 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); | |
150 | audit_free_rule(e); | |
151 | } | |
152 | ||
f368c07d AG |
153 | /* Initialize a parent watch entry. */ |
154 | static struct audit_parent *audit_init_parent(struct nameidata *ndp) | |
155 | { | |
156 | struct audit_parent *parent; | |
157 | s32 wd; | |
158 | ||
159 | parent = kzalloc(sizeof(*parent), GFP_KERNEL); | |
160 | if (unlikely(!parent)) | |
161 | return ERR_PTR(-ENOMEM); | |
162 | ||
163 | INIT_LIST_HEAD(&parent->watches); | |
164 | parent->flags = 0; | |
165 | ||
166 | inotify_init_watch(&parent->wdata); | |
167 | /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */ | |
168 | get_inotify_watch(&parent->wdata); | |
169 | wd = inotify_add_watch(audit_ih, &parent->wdata, ndp->dentry->d_inode, | |
170 | AUDIT_IN_WATCH); | |
171 | if (wd < 0) { | |
172 | audit_free_parent(&parent->wdata); | |
173 | return ERR_PTR(wd); | |
174 | } | |
175 | ||
176 | return parent; | |
177 | } | |
178 | ||
179 | /* Initialize a watch entry. */ | |
180 | static struct audit_watch *audit_init_watch(char *path) | |
181 | { | |
182 | struct audit_watch *watch; | |
183 | ||
184 | watch = kzalloc(sizeof(*watch), GFP_KERNEL); | |
185 | if (unlikely(!watch)) | |
186 | return ERR_PTR(-ENOMEM); | |
187 | ||
188 | INIT_LIST_HEAD(&watch->rules); | |
189 | atomic_set(&watch->count, 1); | |
190 | watch->path = path; | |
191 | watch->dev = (dev_t)-1; | |
192 | watch->ino = (unsigned long)-1; | |
193 | ||
194 | return watch; | |
195 | } | |
196 | ||
3dc7e315 DG |
197 | /* Initialize an audit filterlist entry. */ |
198 | static inline struct audit_entry *audit_init_entry(u32 field_count) | |
199 | { | |
200 | struct audit_entry *entry; | |
201 | struct audit_field *fields; | |
202 | ||
203 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); | |
204 | if (unlikely(!entry)) | |
205 | return NULL; | |
206 | ||
207 | fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL); | |
208 | if (unlikely(!fields)) { | |
209 | kfree(entry); | |
210 | return NULL; | |
211 | } | |
212 | entry->rule.fields = fields; | |
213 | ||
214 | return entry; | |
215 | } | |
216 | ||
93315ed6 AG |
217 | /* Unpack a filter field's string representation from user-space |
218 | * buffer. */ | |
3dc7e315 | 219 | static char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
93315ed6 AG |
220 | { |
221 | char *str; | |
222 | ||
223 | if (!*bufp || (len == 0) || (len > *remain)) | |
224 | return ERR_PTR(-EINVAL); | |
225 | ||
226 | /* Of the currently implemented string fields, PATH_MAX | |
227 | * defines the longest valid length. | |
228 | */ | |
229 | if (len > PATH_MAX) | |
230 | return ERR_PTR(-ENAMETOOLONG); | |
231 | ||
232 | str = kmalloc(len + 1, GFP_KERNEL); | |
233 | if (unlikely(!str)) | |
234 | return ERR_PTR(-ENOMEM); | |
235 | ||
236 | memcpy(str, *bufp, len); | |
237 | str[len] = 0; | |
238 | *bufp += len; | |
239 | *remain -= len; | |
240 | ||
241 | return str; | |
242 | } | |
243 | ||
f368c07d AG |
244 | /* Translate an inode field to kernel respresentation. */ |
245 | static inline int audit_to_inode(struct audit_krule *krule, | |
246 | struct audit_field *f) | |
247 | { | |
248 | if (krule->listnr != AUDIT_FILTER_EXIT || | |
249 | krule->watch || krule->inode_f) | |
250 | return -EINVAL; | |
251 | ||
252 | krule->inode_f = f; | |
253 | return 0; | |
254 | } | |
255 | ||
256 | /* Translate a watch string to kernel respresentation. */ | |
257 | static int audit_to_watch(struct audit_krule *krule, char *path, int len, | |
258 | u32 op) | |
259 | { | |
260 | struct audit_watch *watch; | |
261 | ||
262 | if (!audit_ih) | |
263 | return -EOPNOTSUPP; | |
264 | ||
265 | if (path[0] != '/' || path[len-1] == '/' || | |
266 | krule->listnr != AUDIT_FILTER_EXIT || | |
267 | op & ~AUDIT_EQUAL || | |
268 | krule->inode_f || krule->watch) /* 1 inode # per rule, for hash */ | |
269 | return -EINVAL; | |
270 | ||
271 | watch = audit_init_watch(path); | |
272 | if (unlikely(IS_ERR(watch))) | |
273 | return PTR_ERR(watch); | |
274 | ||
275 | audit_get_watch(watch); | |
276 | krule->watch = watch; | |
277 | ||
278 | return 0; | |
279 | } | |
280 | ||
93315ed6 AG |
281 | /* Common user-space to kernel rule translation. */ |
282 | static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) | |
283 | { | |
284 | unsigned listnr; | |
285 | struct audit_entry *entry; | |
93315ed6 AG |
286 | int i, err; |
287 | ||
288 | err = -EINVAL; | |
289 | listnr = rule->flags & ~AUDIT_FILTER_PREPEND; | |
290 | switch(listnr) { | |
291 | default: | |
292 | goto exit_err; | |
293 | case AUDIT_FILTER_USER: | |
294 | case AUDIT_FILTER_TYPE: | |
295 | #ifdef CONFIG_AUDITSYSCALL | |
296 | case AUDIT_FILTER_ENTRY: | |
297 | case AUDIT_FILTER_EXIT: | |
298 | case AUDIT_FILTER_TASK: | |
299 | #endif | |
300 | ; | |
301 | } | |
014149cc AV |
302 | if (unlikely(rule->action == AUDIT_POSSIBLE)) { |
303 | printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n"); | |
304 | goto exit_err; | |
305 | } | |
306 | if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS) | |
93315ed6 AG |
307 | goto exit_err; |
308 | if (rule->field_count > AUDIT_MAX_FIELDS) | |
309 | goto exit_err; | |
310 | ||
311 | err = -ENOMEM; | |
3dc7e315 DG |
312 | entry = audit_init_entry(rule->field_count); |
313 | if (!entry) | |
93315ed6 | 314 | goto exit_err; |
93315ed6 AG |
315 | |
316 | entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; | |
317 | entry->rule.listnr = listnr; | |
318 | entry->rule.action = rule->action; | |
319 | entry->rule.field_count = rule->field_count; | |
93315ed6 AG |
320 | |
321 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
322 | entry->rule.mask[i] = rule->mask[i]; | |
323 | ||
324 | return entry; | |
325 | ||
326 | exit_err: | |
327 | return ERR_PTR(err); | |
328 | } | |
329 | ||
330 | /* Translate struct audit_rule to kernel's rule respresentation. | |
331 | * Exists for backward compatibility with userspace. */ | |
332 | static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) | |
333 | { | |
334 | struct audit_entry *entry; | |
f368c07d | 335 | struct audit_field *f; |
93315ed6 | 336 | int err = 0; |
fe7752ba DW |
337 | int i; |
338 | ||
93315ed6 AG |
339 | entry = audit_to_entry_common(rule); |
340 | if (IS_ERR(entry)) | |
341 | goto exit_nofree; | |
342 | ||
343 | for (i = 0; i < rule->field_count; i++) { | |
344 | struct audit_field *f = &entry->rule.fields[i]; | |
345 | ||
93315ed6 AG |
346 | f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS); |
347 | f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS); | |
348 | f->val = rule->values[i]; | |
349 | ||
f368c07d | 350 | err = -EINVAL; |
f368c07d | 351 | switch(f->type) { |
0a73dccc | 352 | default: |
3dc7e315 | 353 | goto exit_free; |
0a73dccc AV |
354 | case AUDIT_PID: |
355 | case AUDIT_UID: | |
356 | case AUDIT_EUID: | |
357 | case AUDIT_SUID: | |
358 | case AUDIT_FSUID: | |
359 | case AUDIT_GID: | |
360 | case AUDIT_EGID: | |
361 | case AUDIT_SGID: | |
362 | case AUDIT_FSGID: | |
363 | case AUDIT_LOGINUID: | |
364 | case AUDIT_PERS: | |
365 | case AUDIT_ARCH: | |
366 | case AUDIT_MSGTYPE: | |
367 | case AUDIT_DEVMAJOR: | |
368 | case AUDIT_DEVMINOR: | |
369 | case AUDIT_EXIT: | |
370 | case AUDIT_SUCCESS: | |
371 | case AUDIT_ARG0: | |
372 | case AUDIT_ARG1: | |
373 | case AUDIT_ARG2: | |
374 | case AUDIT_ARG3: | |
375 | break; | |
f368c07d AG |
376 | case AUDIT_INODE: |
377 | err = audit_to_inode(&entry->rule, f); | |
378 | if (err) | |
379 | goto exit_free; | |
380 | break; | |
3dc7e315 DG |
381 | } |
382 | ||
93315ed6 | 383 | entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1; |
d9d9ec6e DK |
384 | |
385 | /* Support for legacy operators where | |
386 | * AUDIT_NEGATE bit signifies != and otherwise assumes == */ | |
93315ed6 | 387 | if (f->op & AUDIT_NEGATE) |
d9d9ec6e DK |
388 | f->op = AUDIT_NOT_EQUAL; |
389 | else if (!f->op) | |
390 | f->op = AUDIT_EQUAL; | |
391 | else if (f->op == AUDIT_OPERATORS) { | |
392 | err = -EINVAL; | |
393 | goto exit_free; | |
394 | } | |
fe7752ba | 395 | } |
93315ed6 | 396 | |
f368c07d AG |
397 | f = entry->rule.inode_f; |
398 | if (f) { | |
399 | switch(f->op) { | |
400 | case AUDIT_NOT_EQUAL: | |
401 | entry->rule.inode_f = NULL; | |
402 | case AUDIT_EQUAL: | |
403 | break; | |
404 | default: | |
405 | goto exit_free; | |
406 | } | |
407 | } | |
408 | ||
93315ed6 AG |
409 | exit_nofree: |
410 | return entry; | |
411 | ||
412 | exit_free: | |
413 | audit_free_rule(entry); | |
414 | return ERR_PTR(err); | |
fe7752ba DW |
415 | } |
416 | ||
93315ed6 AG |
417 | /* Translate struct audit_rule_data to kernel's rule respresentation. */ |
418 | static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, | |
419 | size_t datasz) | |
fe7752ba | 420 | { |
93315ed6 AG |
421 | int err = 0; |
422 | struct audit_entry *entry; | |
f368c07d | 423 | struct audit_field *f; |
93315ed6 | 424 | void *bufp; |
3dc7e315 | 425 | size_t remain = datasz - sizeof(struct audit_rule_data); |
fe7752ba | 426 | int i; |
3dc7e315 | 427 | char *str; |
fe7752ba | 428 | |
93315ed6 AG |
429 | entry = audit_to_entry_common((struct audit_rule *)data); |
430 | if (IS_ERR(entry)) | |
431 | goto exit_nofree; | |
fe7752ba | 432 | |
93315ed6 AG |
433 | bufp = data->buf; |
434 | entry->rule.vers_ops = 2; | |
435 | for (i = 0; i < data->field_count; i++) { | |
436 | struct audit_field *f = &entry->rule.fields[i]; | |
437 | ||
438 | err = -EINVAL; | |
439 | if (!(data->fieldflags[i] & AUDIT_OPERATORS) || | |
440 | data->fieldflags[i] & ~AUDIT_OPERATORS) | |
441 | goto exit_free; | |
442 | ||
443 | f->op = data->fieldflags[i] & AUDIT_OPERATORS; | |
444 | f->type = data->fields[i]; | |
3dc7e315 DG |
445 | f->val = data->values[i]; |
446 | f->se_str = NULL; | |
447 | f->se_rule = NULL; | |
93315ed6 | 448 | switch(f->type) { |
0a73dccc AV |
449 | case AUDIT_PID: |
450 | case AUDIT_UID: | |
451 | case AUDIT_EUID: | |
452 | case AUDIT_SUID: | |
453 | case AUDIT_FSUID: | |
454 | case AUDIT_GID: | |
455 | case AUDIT_EGID: | |
456 | case AUDIT_SGID: | |
457 | case AUDIT_FSGID: | |
458 | case AUDIT_LOGINUID: | |
459 | case AUDIT_PERS: | |
460 | case AUDIT_ARCH: | |
461 | case AUDIT_MSGTYPE: | |
462 | case AUDIT_PPID: | |
463 | case AUDIT_DEVMAJOR: | |
464 | case AUDIT_DEVMINOR: | |
465 | case AUDIT_EXIT: | |
466 | case AUDIT_SUCCESS: | |
467 | case AUDIT_ARG0: | |
468 | case AUDIT_ARG1: | |
469 | case AUDIT_ARG2: | |
470 | case AUDIT_ARG3: | |
471 | break; | |
3dc7e315 DG |
472 | case AUDIT_SE_USER: |
473 | case AUDIT_SE_ROLE: | |
474 | case AUDIT_SE_TYPE: | |
475 | case AUDIT_SE_SEN: | |
476 | case AUDIT_SE_CLR: | |
477 | str = audit_unpack_string(&bufp, &remain, f->val); | |
478 | if (IS_ERR(str)) | |
479 | goto exit_free; | |
480 | entry->rule.buflen += f->val; | |
481 | ||
482 | err = selinux_audit_rule_init(f->type, f->op, str, | |
483 | &f->se_rule); | |
484 | /* Keep currently invalid fields around in case they | |
485 | * become valid after a policy reload. */ | |
486 | if (err == -EINVAL) { | |
487 | printk(KERN_WARNING "audit rule for selinux " | |
488 | "\'%s\' is invalid\n", str); | |
489 | err = 0; | |
490 | } | |
491 | if (err) { | |
492 | kfree(str); | |
493 | goto exit_free; | |
494 | } else | |
495 | f->se_str = str; | |
496 | break; | |
f368c07d AG |
497 | case AUDIT_WATCH: |
498 | str = audit_unpack_string(&bufp, &remain, f->val); | |
499 | if (IS_ERR(str)) | |
500 | goto exit_free; | |
501 | entry->rule.buflen += f->val; | |
502 | ||
503 | err = audit_to_watch(&entry->rule, str, f->val, f->op); | |
504 | if (err) { | |
505 | kfree(str); | |
506 | goto exit_free; | |
507 | } | |
508 | break; | |
509 | case AUDIT_INODE: | |
510 | err = audit_to_inode(&entry->rule, f); | |
511 | if (err) | |
512 | goto exit_free; | |
513 | break; | |
0a73dccc AV |
514 | default: |
515 | goto exit_free; | |
f368c07d AG |
516 | } |
517 | } | |
518 | ||
519 | f = entry->rule.inode_f; | |
520 | if (f) { | |
521 | switch(f->op) { | |
522 | case AUDIT_NOT_EQUAL: | |
523 | entry->rule.inode_f = NULL; | |
524 | case AUDIT_EQUAL: | |
525 | break; | |
526 | default: | |
527 | goto exit_free; | |
93315ed6 AG |
528 | } |
529 | } | |
530 | ||
531 | exit_nofree: | |
532 | return entry; | |
533 | ||
534 | exit_free: | |
535 | audit_free_rule(entry); | |
536 | return ERR_PTR(err); | |
537 | } | |
538 | ||
539 | /* Pack a filter field's string representation into data block. */ | |
540 | static inline size_t audit_pack_string(void **bufp, char *str) | |
541 | { | |
542 | size_t len = strlen(str); | |
543 | ||
544 | memcpy(*bufp, str, len); | |
545 | *bufp += len; | |
546 | ||
547 | return len; | |
548 | } | |
549 | ||
550 | /* Translate kernel rule respresentation to struct audit_rule. | |
551 | * Exists for backward compatibility with userspace. */ | |
552 | static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule) | |
553 | { | |
554 | struct audit_rule *rule; | |
555 | int i; | |
556 | ||
557 | rule = kmalloc(sizeof(*rule), GFP_KERNEL); | |
558 | if (unlikely(!rule)) | |
0a3b483e | 559 | return NULL; |
93315ed6 AG |
560 | memset(rule, 0, sizeof(*rule)); |
561 | ||
562 | rule->flags = krule->flags | krule->listnr; | |
563 | rule->action = krule->action; | |
564 | rule->field_count = krule->field_count; | |
565 | for (i = 0; i < rule->field_count; i++) { | |
566 | rule->values[i] = krule->fields[i].val; | |
567 | rule->fields[i] = krule->fields[i].type; | |
568 | ||
569 | if (krule->vers_ops == 1) { | |
570 | if (krule->fields[i].op & AUDIT_NOT_EQUAL) | |
571 | rule->fields[i] |= AUDIT_NEGATE; | |
572 | } else { | |
573 | rule->fields[i] |= krule->fields[i].op; | |
574 | } | |
575 | } | |
576 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i]; | |
577 | ||
578 | return rule; | |
579 | } | |
fe7752ba | 580 | |
93315ed6 AG |
581 | /* Translate kernel rule respresentation to struct audit_rule_data. */ |
582 | static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) | |
583 | { | |
584 | struct audit_rule_data *data; | |
585 | void *bufp; | |
586 | int i; | |
587 | ||
588 | data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); | |
589 | if (unlikely(!data)) | |
0a3b483e | 590 | return NULL; |
93315ed6 AG |
591 | memset(data, 0, sizeof(*data)); |
592 | ||
593 | data->flags = krule->flags | krule->listnr; | |
594 | data->action = krule->action; | |
595 | data->field_count = krule->field_count; | |
596 | bufp = data->buf; | |
597 | for (i = 0; i < data->field_count; i++) { | |
598 | struct audit_field *f = &krule->fields[i]; | |
599 | ||
600 | data->fields[i] = f->type; | |
601 | data->fieldflags[i] = f->op; | |
602 | switch(f->type) { | |
3dc7e315 DG |
603 | case AUDIT_SE_USER: |
604 | case AUDIT_SE_ROLE: | |
605 | case AUDIT_SE_TYPE: | |
606 | case AUDIT_SE_SEN: | |
607 | case AUDIT_SE_CLR: | |
608 | data->buflen += data->values[i] = | |
609 | audit_pack_string(&bufp, f->se_str); | |
610 | break; | |
f368c07d AG |
611 | case AUDIT_WATCH: |
612 | data->buflen += data->values[i] = | |
613 | audit_pack_string(&bufp, krule->watch->path); | |
614 | break; | |
93315ed6 AG |
615 | default: |
616 | data->values[i] = f->val; | |
617 | } | |
618 | } | |
619 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; | |
620 | ||
621 | return data; | |
622 | } | |
623 | ||
624 | /* Compare two rules in kernel format. Considered success if rules | |
625 | * don't match. */ | |
626 | static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) | |
627 | { | |
628 | int i; | |
629 | ||
630 | if (a->flags != b->flags || | |
631 | a->listnr != b->listnr || | |
632 | a->action != b->action || | |
633 | a->field_count != b->field_count) | |
fe7752ba DW |
634 | return 1; |
635 | ||
636 | for (i = 0; i < a->field_count; i++) { | |
93315ed6 AG |
637 | if (a->fields[i].type != b->fields[i].type || |
638 | a->fields[i].op != b->fields[i].op) | |
fe7752ba | 639 | return 1; |
93315ed6 AG |
640 | |
641 | switch(a->fields[i].type) { | |
3dc7e315 DG |
642 | case AUDIT_SE_USER: |
643 | case AUDIT_SE_ROLE: | |
644 | case AUDIT_SE_TYPE: | |
645 | case AUDIT_SE_SEN: | |
646 | case AUDIT_SE_CLR: | |
647 | if (strcmp(a->fields[i].se_str, b->fields[i].se_str)) | |
648 | return 1; | |
649 | break; | |
f368c07d AG |
650 | case AUDIT_WATCH: |
651 | if (strcmp(a->watch->path, b->watch->path)) | |
652 | return 1; | |
653 | break; | |
93315ed6 AG |
654 | default: |
655 | if (a->fields[i].val != b->fields[i].val) | |
656 | return 1; | |
657 | } | |
fe7752ba DW |
658 | } |
659 | ||
660 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
661 | if (a->mask[i] != b->mask[i]) | |
662 | return 1; | |
663 | ||
664 | return 0; | |
665 | } | |
666 | ||
f368c07d AG |
667 | /* Duplicate the given audit watch. The new watch's rules list is initialized |
668 | * to an empty list and wlist is undefined. */ | |
669 | static struct audit_watch *audit_dupe_watch(struct audit_watch *old) | |
670 | { | |
671 | char *path; | |
672 | struct audit_watch *new; | |
673 | ||
674 | path = kstrdup(old->path, GFP_KERNEL); | |
675 | if (unlikely(!path)) | |
676 | return ERR_PTR(-ENOMEM); | |
677 | ||
678 | new = audit_init_watch(path); | |
679 | if (unlikely(IS_ERR(new))) { | |
680 | kfree(path); | |
681 | goto out; | |
682 | } | |
683 | ||
684 | new->dev = old->dev; | |
685 | new->ino = old->ino; | |
686 | get_inotify_watch(&old->parent->wdata); | |
687 | new->parent = old->parent; | |
688 | ||
689 | out: | |
690 | return new; | |
691 | } | |
692 | ||
3dc7e315 DG |
693 | /* Duplicate selinux field information. The se_rule is opaque, so must be |
694 | * re-initialized. */ | |
695 | static inline int audit_dupe_selinux_field(struct audit_field *df, | |
696 | struct audit_field *sf) | |
697 | { | |
698 | int ret = 0; | |
699 | char *se_str; | |
700 | ||
701 | /* our own copy of se_str */ | |
702 | se_str = kstrdup(sf->se_str, GFP_KERNEL); | |
703 | if (unlikely(IS_ERR(se_str))) | |
704 | return -ENOMEM; | |
705 | df->se_str = se_str; | |
706 | ||
707 | /* our own (refreshed) copy of se_rule */ | |
708 | ret = selinux_audit_rule_init(df->type, df->op, df->se_str, | |
709 | &df->se_rule); | |
710 | /* Keep currently invalid fields around in case they | |
711 | * become valid after a policy reload. */ | |
712 | if (ret == -EINVAL) { | |
713 | printk(KERN_WARNING "audit rule for selinux \'%s\' is " | |
714 | "invalid\n", df->se_str); | |
715 | ret = 0; | |
716 | } | |
717 | ||
718 | return ret; | |
719 | } | |
720 | ||
721 | /* Duplicate an audit rule. This will be a deep copy with the exception | |
722 | * of the watch - that pointer is carried over. The selinux specific fields | |
723 | * will be updated in the copy. The point is to be able to replace the old | |
f368c07d AG |
724 | * rule with the new rule in the filterlist, then free the old rule. |
725 | * The rlist element is undefined; list manipulations are handled apart from | |
726 | * the initial copy. */ | |
727 | static struct audit_entry *audit_dupe_rule(struct audit_krule *old, | |
728 | struct audit_watch *watch) | |
3dc7e315 DG |
729 | { |
730 | u32 fcount = old->field_count; | |
731 | struct audit_entry *entry; | |
732 | struct audit_krule *new; | |
733 | int i, err = 0; | |
734 | ||
735 | entry = audit_init_entry(fcount); | |
736 | if (unlikely(!entry)) | |
737 | return ERR_PTR(-ENOMEM); | |
738 | ||
739 | new = &entry->rule; | |
740 | new->vers_ops = old->vers_ops; | |
741 | new->flags = old->flags; | |
742 | new->listnr = old->listnr; | |
743 | new->action = old->action; | |
744 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
745 | new->mask[i] = old->mask[i]; | |
746 | new->buflen = old->buflen; | |
f368c07d AG |
747 | new->inode_f = old->inode_f; |
748 | new->watch = NULL; | |
3dc7e315 DG |
749 | new->field_count = old->field_count; |
750 | memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); | |
751 | ||
752 | /* deep copy this information, updating the se_rule fields, because | |
753 | * the originals will all be freed when the old rule is freed. */ | |
754 | for (i = 0; i < fcount; i++) { | |
755 | switch (new->fields[i].type) { | |
756 | case AUDIT_SE_USER: | |
757 | case AUDIT_SE_ROLE: | |
758 | case AUDIT_SE_TYPE: | |
759 | case AUDIT_SE_SEN: | |
760 | case AUDIT_SE_CLR: | |
761 | err = audit_dupe_selinux_field(&new->fields[i], | |
762 | &old->fields[i]); | |
763 | } | |
764 | if (err) { | |
765 | audit_free_rule(entry); | |
766 | return ERR_PTR(err); | |
767 | } | |
768 | } | |
769 | ||
f368c07d AG |
770 | if (watch) { |
771 | audit_get_watch(watch); | |
772 | new->watch = watch; | |
773 | } | |
774 | ||
3dc7e315 DG |
775 | return entry; |
776 | } | |
777 | ||
f368c07d AG |
778 | /* Update inode info in audit rules based on filesystem event. */ |
779 | static void audit_update_watch(struct audit_parent *parent, | |
780 | const char *dname, dev_t dev, | |
781 | unsigned long ino, unsigned invalidating) | |
782 | { | |
783 | struct audit_watch *owatch, *nwatch, *nextw; | |
784 | struct audit_krule *r, *nextr; | |
785 | struct audit_entry *oentry, *nentry; | |
786 | struct audit_buffer *ab; | |
787 | ||
788 | mutex_lock(&audit_filter_mutex); | |
789 | list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) { | |
9c937dcc | 790 | if (audit_compare_dname_path(dname, owatch->path, NULL)) |
f368c07d AG |
791 | continue; |
792 | ||
793 | /* If the update involves invalidating rules, do the inode-based | |
794 | * filtering now, so we don't omit records. */ | |
795 | if (invalidating && | |
796 | audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT) | |
797 | audit_set_auditable(current->audit_context); | |
798 | ||
799 | nwatch = audit_dupe_watch(owatch); | |
800 | if (unlikely(IS_ERR(nwatch))) { | |
801 | mutex_unlock(&audit_filter_mutex); | |
802 | audit_panic("error updating watch, skipping"); | |
803 | return; | |
804 | } | |
805 | nwatch->dev = dev; | |
806 | nwatch->ino = ino; | |
807 | ||
808 | list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) { | |
809 | ||
810 | oentry = container_of(r, struct audit_entry, rule); | |
811 | list_del(&oentry->rule.rlist); | |
812 | list_del_rcu(&oentry->list); | |
813 | ||
814 | nentry = audit_dupe_rule(&oentry->rule, nwatch); | |
815 | if (unlikely(IS_ERR(nentry))) | |
816 | audit_panic("error updating watch, removing"); | |
817 | else { | |
818 | int h = audit_hash_ino((u32)ino); | |
819 | list_add(&nentry->rule.rlist, &nwatch->rules); | |
820 | list_add_rcu(&nentry->list, &audit_inode_hash[h]); | |
821 | } | |
822 | ||
823 | call_rcu(&oentry->rcu, audit_free_rule_rcu); | |
824 | } | |
825 | ||
826 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); | |
827 | audit_log_format(ab, "audit updated rules specifying watch="); | |
828 | audit_log_untrustedstring(ab, owatch->path); | |
829 | audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino); | |
830 | audit_log_end(ab); | |
831 | ||
832 | audit_remove_watch(owatch); | |
833 | goto add_watch_to_parent; /* event applies to a single watch */ | |
834 | } | |
835 | mutex_unlock(&audit_filter_mutex); | |
836 | return; | |
837 | ||
838 | add_watch_to_parent: | |
839 | list_add(&nwatch->wlist, &parent->watches); | |
840 | mutex_unlock(&audit_filter_mutex); | |
841 | return; | |
842 | } | |
843 | ||
844 | /* Remove all watches & rules associated with a parent that is going away. */ | |
845 | static void audit_remove_parent_watches(struct audit_parent *parent) | |
846 | { | |
847 | struct audit_watch *w, *nextw; | |
848 | struct audit_krule *r, *nextr; | |
849 | struct audit_entry *e; | |
850 | ||
851 | mutex_lock(&audit_filter_mutex); | |
852 | parent->flags |= AUDIT_PARENT_INVALID; | |
853 | list_for_each_entry_safe(w, nextw, &parent->watches, wlist) { | |
854 | list_for_each_entry_safe(r, nextr, &w->rules, rlist) { | |
855 | e = container_of(r, struct audit_entry, rule); | |
856 | list_del(&r->rlist); | |
857 | list_del_rcu(&e->list); | |
858 | call_rcu(&e->rcu, audit_free_rule_rcu); | |
859 | ||
860 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
861 | "audit implicitly removed rule from list=%d\n", | |
862 | AUDIT_FILTER_EXIT); | |
863 | } | |
864 | audit_remove_watch(w); | |
865 | } | |
866 | mutex_unlock(&audit_filter_mutex); | |
867 | } | |
868 | ||
869 | /* Unregister inotify watches for parents on in_list. | |
870 | * Generates an IN_IGNORED event. */ | |
871 | static void audit_inotify_unregister(struct list_head *in_list) | |
872 | { | |
873 | struct audit_parent *p, *n; | |
874 | ||
875 | list_for_each_entry_safe(p, n, in_list, ilist) { | |
876 | list_del(&p->ilist); | |
877 | inotify_rm_watch(audit_ih, &p->wdata); | |
878 | /* the put matching the get in audit_do_del_rule() */ | |
879 | put_inotify_watch(&p->wdata); | |
880 | } | |
881 | } | |
882 | ||
883 | /* Find an existing audit rule. | |
884 | * Caller must hold audit_filter_mutex to prevent stale rule data. */ | |
885 | static struct audit_entry *audit_find_rule(struct audit_entry *entry, | |
886 | struct list_head *list) | |
887 | { | |
888 | struct audit_entry *e, *found = NULL; | |
889 | int h; | |
890 | ||
891 | if (entry->rule.watch) { | |
892 | /* we don't know the inode number, so must walk entire hash */ | |
893 | for (h = 0; h < AUDIT_INODE_BUCKETS; h++) { | |
894 | list = &audit_inode_hash[h]; | |
895 | list_for_each_entry(e, list, list) | |
896 | if (!audit_compare_rule(&entry->rule, &e->rule)) { | |
897 | found = e; | |
898 | goto out; | |
899 | } | |
900 | } | |
901 | goto out; | |
902 | } | |
903 | ||
904 | list_for_each_entry(e, list, list) | |
905 | if (!audit_compare_rule(&entry->rule, &e->rule)) { | |
906 | found = e; | |
907 | goto out; | |
908 | } | |
909 | ||
910 | out: | |
911 | return found; | |
912 | } | |
913 | ||
914 | /* Get path information necessary for adding watches. */ | |
915 | static int audit_get_nd(char *path, struct nameidata **ndp, | |
916 | struct nameidata **ndw) | |
917 | { | |
918 | struct nameidata *ndparent, *ndwatch; | |
919 | int err; | |
920 | ||
921 | ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL); | |
922 | if (unlikely(!ndparent)) | |
923 | return -ENOMEM; | |
924 | ||
925 | ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL); | |
926 | if (unlikely(!ndwatch)) { | |
927 | kfree(ndparent); | |
928 | return -ENOMEM; | |
929 | } | |
930 | ||
931 | err = path_lookup(path, LOOKUP_PARENT, ndparent); | |
932 | if (err) { | |
933 | kfree(ndparent); | |
934 | kfree(ndwatch); | |
935 | return err; | |
936 | } | |
937 | ||
938 | err = path_lookup(path, 0, ndwatch); | |
939 | if (err) { | |
940 | kfree(ndwatch); | |
941 | ndwatch = NULL; | |
942 | } | |
943 | ||
944 | *ndp = ndparent; | |
945 | *ndw = ndwatch; | |
946 | ||
947 | return 0; | |
948 | } | |
949 | ||
950 | /* Release resources used for watch path information. */ | |
951 | static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw) | |
952 | { | |
953 | if (ndp) { | |
954 | path_release(ndp); | |
955 | kfree(ndp); | |
956 | } | |
957 | if (ndw) { | |
958 | path_release(ndw); | |
959 | kfree(ndw); | |
960 | } | |
961 | } | |
962 | ||
963 | /* Associate the given rule with an existing parent inotify_watch. | |
964 | * Caller must hold audit_filter_mutex. */ | |
965 | static void audit_add_to_parent(struct audit_krule *krule, | |
966 | struct audit_parent *parent) | |
967 | { | |
968 | struct audit_watch *w, *watch = krule->watch; | |
969 | int watch_found = 0; | |
970 | ||
971 | list_for_each_entry(w, &parent->watches, wlist) { | |
972 | if (strcmp(watch->path, w->path)) | |
973 | continue; | |
974 | ||
975 | watch_found = 1; | |
976 | ||
977 | /* put krule's and initial refs to temporary watch */ | |
978 | audit_put_watch(watch); | |
979 | audit_put_watch(watch); | |
980 | ||
981 | audit_get_watch(w); | |
982 | krule->watch = watch = w; | |
983 | break; | |
984 | } | |
985 | ||
986 | if (!watch_found) { | |
987 | get_inotify_watch(&parent->wdata); | |
988 | watch->parent = parent; | |
989 | ||
990 | list_add(&watch->wlist, &parent->watches); | |
991 | } | |
992 | list_add(&krule->rlist, &watch->rules); | |
993 | } | |
994 | ||
995 | /* Find a matching watch entry, or add this one. | |
996 | * Caller must hold audit_filter_mutex. */ | |
997 | static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp, | |
998 | struct nameidata *ndw) | |
999 | { | |
1000 | struct audit_watch *watch = krule->watch; | |
1001 | struct inotify_watch *i_watch; | |
1002 | struct audit_parent *parent; | |
1003 | int ret = 0; | |
1004 | ||
1005 | /* update watch filter fields */ | |
1006 | if (ndw) { | |
1007 | watch->dev = ndw->dentry->d_inode->i_sb->s_dev; | |
1008 | watch->ino = ndw->dentry->d_inode->i_ino; | |
1009 | } | |
1010 | ||
1011 | /* The audit_filter_mutex must not be held during inotify calls because | |
1012 | * we hold it during inotify event callback processing. If an existing | |
1013 | * inotify watch is found, inotify_find_watch() grabs a reference before | |
1014 | * returning. | |
1015 | */ | |
1016 | mutex_unlock(&audit_filter_mutex); | |
1017 | ||
1018 | if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) { | |
1019 | parent = audit_init_parent(ndp); | |
1020 | if (IS_ERR(parent)) { | |
1021 | /* caller expects mutex locked */ | |
1022 | mutex_lock(&audit_filter_mutex); | |
1023 | return PTR_ERR(parent); | |
1024 | } | |
1025 | } else | |
1026 | parent = container_of(i_watch, struct audit_parent, wdata); | |
1027 | ||
1028 | mutex_lock(&audit_filter_mutex); | |
1029 | ||
1030 | /* parent was moved before we took audit_filter_mutex */ | |
1031 | if (parent->flags & AUDIT_PARENT_INVALID) | |
1032 | ret = -ENOENT; | |
1033 | else | |
1034 | audit_add_to_parent(krule, parent); | |
1035 | ||
1036 | /* match get in audit_init_parent or inotify_find_watch */ | |
1037 | put_inotify_watch(&parent->wdata); | |
1038 | return ret; | |
1039 | } | |
1040 | ||
1041 | /* Add rule to given filterlist if not a duplicate. */ | |
93315ed6 | 1042 | static inline int audit_add_rule(struct audit_entry *entry, |
f368c07d | 1043 | struct list_head *list) |
fe7752ba | 1044 | { |
93315ed6 | 1045 | struct audit_entry *e; |
f368c07d AG |
1046 | struct audit_field *inode_f = entry->rule.inode_f; |
1047 | struct audit_watch *watch = entry->rule.watch; | |
1048 | struct nameidata *ndp, *ndw; | |
1049 | int h, err, putnd_needed = 0; | |
1050 | ||
1051 | if (inode_f) { | |
1052 | h = audit_hash_ino(inode_f->val); | |
1053 | list = &audit_inode_hash[h]; | |
1054 | } | |
1055 | ||
1056 | mutex_lock(&audit_filter_mutex); | |
1057 | e = audit_find_rule(entry, list); | |
1058 | mutex_unlock(&audit_filter_mutex); | |
1059 | if (e) { | |
1060 | err = -EEXIST; | |
1061 | goto error; | |
1062 | } | |
fe7752ba | 1063 | |
f368c07d AG |
1064 | /* Avoid calling path_lookup under audit_filter_mutex. */ |
1065 | if (watch) { | |
1066 | err = audit_get_nd(watch->path, &ndp, &ndw); | |
1067 | if (err) | |
1068 | goto error; | |
1069 | putnd_needed = 1; | |
1070 | } | |
1071 | ||
1072 | mutex_lock(&audit_filter_mutex); | |
1073 | if (watch) { | |
1074 | /* audit_filter_mutex is dropped and re-taken during this call */ | |
1075 | err = audit_add_watch(&entry->rule, ndp, ndw); | |
1076 | if (err) { | |
1077 | mutex_unlock(&audit_filter_mutex); | |
1078 | goto error; | |
1079 | } | |
1080 | h = audit_hash_ino((u32)watch->ino); | |
1081 | list = &audit_inode_hash[h]; | |
fe7752ba DW |
1082 | } |
1083 | ||
fe7752ba | 1084 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
fe7752ba | 1085 | list_add_rcu(&entry->list, list); |
6a2bceec | 1086 | entry->rule.flags &= ~AUDIT_FILTER_PREPEND; |
fe7752ba DW |
1087 | } else { |
1088 | list_add_tail_rcu(&entry->list, list); | |
1089 | } | |
f368c07d | 1090 | mutex_unlock(&audit_filter_mutex); |
fe7752ba | 1091 | |
f368c07d AG |
1092 | if (putnd_needed) |
1093 | audit_put_nd(ndp, ndw); | |
1094 | ||
1095 | return 0; | |
1096 | ||
1097 | error: | |
1098 | if (putnd_needed) | |
1099 | audit_put_nd(ndp, ndw); | |
1100 | if (watch) | |
1101 | audit_put_watch(watch); /* tmp watch, matches initial get */ | |
1102 | return err; | |
fe7752ba DW |
1103 | } |
1104 | ||
f368c07d | 1105 | /* Remove an existing rule from filterlist. */ |
93315ed6 | 1106 | static inline int audit_del_rule(struct audit_entry *entry, |
fe7752ba DW |
1107 | struct list_head *list) |
1108 | { | |
1109 | struct audit_entry *e; | |
f368c07d AG |
1110 | struct audit_field *inode_f = entry->rule.inode_f; |
1111 | struct audit_watch *watch, *tmp_watch = entry->rule.watch; | |
1112 | LIST_HEAD(inotify_list); | |
1113 | int h, ret = 0; | |
1114 | ||
1115 | if (inode_f) { | |
1116 | h = audit_hash_ino(inode_f->val); | |
1117 | list = &audit_inode_hash[h]; | |
1118 | } | |
fe7752ba | 1119 | |
f368c07d AG |
1120 | mutex_lock(&audit_filter_mutex); |
1121 | e = audit_find_rule(entry, list); | |
1122 | if (!e) { | |
1123 | mutex_unlock(&audit_filter_mutex); | |
1124 | ret = -ENOENT; | |
1125 | goto out; | |
1126 | } | |
1127 | ||
1128 | watch = e->rule.watch; | |
1129 | if (watch) { | |
1130 | struct audit_parent *parent = watch->parent; | |
1131 | ||
1132 | list_del(&e->rule.rlist); | |
1133 | ||
1134 | if (list_empty(&watch->rules)) { | |
1135 | audit_remove_watch(watch); | |
1136 | ||
1137 | if (list_empty(&parent->watches)) { | |
1138 | /* Put parent on the inotify un-registration | |
1139 | * list. Grab a reference before releasing | |
1140 | * audit_filter_mutex, to be released in | |
1141 | * audit_inotify_unregister(). */ | |
1142 | list_add(&parent->ilist, &inotify_list); | |
1143 | get_inotify_watch(&parent->wdata); | |
1144 | } | |
fe7752ba DW |
1145 | } |
1146 | } | |
f368c07d AG |
1147 | |
1148 | list_del_rcu(&e->list); | |
1149 | call_rcu(&e->rcu, audit_free_rule_rcu); | |
1150 | ||
1151 | mutex_unlock(&audit_filter_mutex); | |
1152 | ||
1153 | if (!list_empty(&inotify_list)) | |
1154 | audit_inotify_unregister(&inotify_list); | |
1155 | ||
1156 | out: | |
1157 | if (tmp_watch) | |
1158 | audit_put_watch(tmp_watch); /* match initial get */ | |
1159 | ||
1160 | return ret; | |
fe7752ba DW |
1161 | } |
1162 | ||
93315ed6 AG |
1163 | /* List rules using struct audit_rule. Exists for backward |
1164 | * compatibility with userspace. */ | |
9044e6bc | 1165 | static void audit_list(int pid, int seq, struct sk_buff_head *q) |
fe7752ba | 1166 | { |
9044e6bc | 1167 | struct sk_buff *skb; |
fe7752ba DW |
1168 | struct audit_entry *entry; |
1169 | int i; | |
1170 | ||
f368c07d AG |
1171 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
1172 | * iterator to sync with list writers. */ | |
fe7752ba | 1173 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
93315ed6 AG |
1174 | list_for_each_entry(entry, &audit_filter_list[i], list) { |
1175 | struct audit_rule *rule; | |
1176 | ||
1177 | rule = audit_krule_to_rule(&entry->rule); | |
1178 | if (unlikely(!rule)) | |
1179 | break; | |
9044e6bc | 1180 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1, |
93315ed6 | 1181 | rule, sizeof(*rule)); |
9044e6bc AV |
1182 | if (skb) |
1183 | skb_queue_tail(q, skb); | |
93315ed6 AG |
1184 | kfree(rule); |
1185 | } | |
fe7752ba | 1186 | } |
f368c07d AG |
1187 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) { |
1188 | list_for_each_entry(entry, &audit_inode_hash[i], list) { | |
1189 | struct audit_rule *rule; | |
1190 | ||
1191 | rule = audit_krule_to_rule(&entry->rule); | |
1192 | if (unlikely(!rule)) | |
1193 | break; | |
1194 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1, | |
1195 | rule, sizeof(*rule)); | |
1196 | if (skb) | |
1197 | skb_queue_tail(q, skb); | |
1198 | kfree(rule); | |
1199 | } | |
1200 | } | |
9044e6bc AV |
1201 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); |
1202 | if (skb) | |
1203 | skb_queue_tail(q, skb); | |
fe7752ba DW |
1204 | } |
1205 | ||
93315ed6 | 1206 | /* List rules using struct audit_rule_data. */ |
9044e6bc | 1207 | static void audit_list_rules(int pid, int seq, struct sk_buff_head *q) |
93315ed6 | 1208 | { |
9044e6bc | 1209 | struct sk_buff *skb; |
93315ed6 AG |
1210 | struct audit_entry *e; |
1211 | int i; | |
1212 | ||
f368c07d AG |
1213 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
1214 | * iterator to sync with list writers. */ | |
93315ed6 AG |
1215 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
1216 | list_for_each_entry(e, &audit_filter_list[i], list) { | |
1217 | struct audit_rule_data *data; | |
1218 | ||
1219 | data = audit_krule_to_data(&e->rule); | |
1220 | if (unlikely(!data)) | |
1221 | break; | |
9044e6bc | 1222 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, |
f368c07d AG |
1223 | data, sizeof(*data) + data->buflen); |
1224 | if (skb) | |
1225 | skb_queue_tail(q, skb); | |
1226 | kfree(data); | |
1227 | } | |
1228 | } | |
1229 | for (i=0; i< AUDIT_INODE_BUCKETS; i++) { | |
1230 | list_for_each_entry(e, &audit_inode_hash[i], list) { | |
1231 | struct audit_rule_data *data; | |
1232 | ||
1233 | data = audit_krule_to_data(&e->rule); | |
1234 | if (unlikely(!data)) | |
1235 | break; | |
1236 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, | |
1237 | data, sizeof(*data) + data->buflen); | |
9044e6bc AV |
1238 | if (skb) |
1239 | skb_queue_tail(q, skb); | |
93315ed6 AG |
1240 | kfree(data); |
1241 | } | |
1242 | } | |
9044e6bc AV |
1243 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
1244 | if (skb) | |
1245 | skb_queue_tail(q, skb); | |
93315ed6 AG |
1246 | } |
1247 | ||
fe7752ba DW |
1248 | /** |
1249 | * audit_receive_filter - apply all rules to the specified message type | |
1250 | * @type: audit message type | |
1251 | * @pid: target pid for netlink audit messages | |
1252 | * @uid: target uid for netlink audit messages | |
1253 | * @seq: netlink audit message sequence (serial) number | |
1254 | * @data: payload data | |
93315ed6 | 1255 | * @datasz: size of payload data |
fe7752ba | 1256 | * @loginuid: loginuid of sender |
ce29b682 | 1257 | * @sid: SE Linux Security ID of sender |
fe7752ba DW |
1258 | */ |
1259 | int audit_receive_filter(int type, int pid, int uid, int seq, void *data, | |
ce29b682 | 1260 | size_t datasz, uid_t loginuid, u32 sid) |
fe7752ba DW |
1261 | { |
1262 | struct task_struct *tsk; | |
9044e6bc | 1263 | struct audit_netlink_list *dest; |
93315ed6 AG |
1264 | int err = 0; |
1265 | struct audit_entry *entry; | |
fe7752ba DW |
1266 | |
1267 | switch (type) { | |
1268 | case AUDIT_LIST: | |
93315ed6 | 1269 | case AUDIT_LIST_RULES: |
fe7752ba DW |
1270 | /* We can't just spew out the rules here because we might fill |
1271 | * the available socket buffer space and deadlock waiting for | |
1272 | * auditctl to read from it... which isn't ever going to | |
1273 | * happen if we're actually running in the context of auditctl | |
1274 | * trying to _send_ the stuff */ | |
1275 | ||
9044e6bc | 1276 | dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); |
fe7752ba DW |
1277 | if (!dest) |
1278 | return -ENOMEM; | |
9044e6bc AV |
1279 | dest->pid = pid; |
1280 | skb_queue_head_init(&dest->q); | |
fe7752ba | 1281 | |
f368c07d | 1282 | mutex_lock(&audit_filter_mutex); |
93315ed6 | 1283 | if (type == AUDIT_LIST) |
9044e6bc | 1284 | audit_list(pid, seq, &dest->q); |
93315ed6 | 1285 | else |
9044e6bc | 1286 | audit_list_rules(pid, seq, &dest->q); |
f368c07d | 1287 | mutex_unlock(&audit_filter_mutex); |
9044e6bc AV |
1288 | |
1289 | tsk = kthread_run(audit_send_list, dest, "audit_send_list"); | |
fe7752ba | 1290 | if (IS_ERR(tsk)) { |
9044e6bc | 1291 | skb_queue_purge(&dest->q); |
fe7752ba DW |
1292 | kfree(dest); |
1293 | err = PTR_ERR(tsk); | |
1294 | } | |
1295 | break; | |
1296 | case AUDIT_ADD: | |
93315ed6 AG |
1297 | case AUDIT_ADD_RULE: |
1298 | if (type == AUDIT_ADD) | |
1299 | entry = audit_rule_to_entry(data); | |
1300 | else | |
1301 | entry = audit_data_to_entry(data, datasz); | |
1302 | if (IS_ERR(entry)) | |
1303 | return PTR_ERR(entry); | |
1304 | ||
1305 | err = audit_add_rule(entry, | |
1306 | &audit_filter_list[entry->rule.listnr]); | |
f368c07d | 1307 | |
ce29b682 SG |
1308 | if (sid) { |
1309 | char *ctx = NULL; | |
1310 | u32 len; | |
1311 | if (selinux_ctxid_to_string(sid, &ctx, &len)) { | |
1312 | /* Maybe call audit_panic? */ | |
1313 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
1314 | "auid=%u ssid=%u add rule to list=%d res=%d", | |
1315 | loginuid, sid, entry->rule.listnr, !err); | |
1316 | } else | |
1317 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
1318 | "auid=%u subj=%s add rule to list=%d res=%d", | |
1319 | loginuid, ctx, entry->rule.listnr, !err); | |
1320 | kfree(ctx); | |
1321 | } else | |
1322 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
1323 | "auid=%u add rule to list=%d res=%d", | |
1324 | loginuid, entry->rule.listnr, !err); | |
5d330108 SG |
1325 | |
1326 | if (err) | |
93315ed6 | 1327 | audit_free_rule(entry); |
fe7752ba DW |
1328 | break; |
1329 | case AUDIT_DEL: | |
93315ed6 AG |
1330 | case AUDIT_DEL_RULE: |
1331 | if (type == AUDIT_DEL) | |
1332 | entry = audit_rule_to_entry(data); | |
1333 | else | |
1334 | entry = audit_data_to_entry(data, datasz); | |
1335 | if (IS_ERR(entry)) | |
1336 | return PTR_ERR(entry); | |
1337 | ||
1338 | err = audit_del_rule(entry, | |
1339 | &audit_filter_list[entry->rule.listnr]); | |
ce29b682 SG |
1340 | |
1341 | if (sid) { | |
1342 | char *ctx = NULL; | |
1343 | u32 len; | |
1344 | if (selinux_ctxid_to_string(sid, &ctx, &len)) { | |
1345 | /* Maybe call audit_panic? */ | |
1346 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
1347 | "auid=%u ssid=%u remove rule from list=%d res=%d", | |
1348 | loginuid, sid, entry->rule.listnr, !err); | |
1349 | } else | |
1350 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
1351 | "auid=%u subj=%s remove rule from list=%d res=%d", | |
1352 | loginuid, ctx, entry->rule.listnr, !err); | |
1353 | kfree(ctx); | |
1354 | } else | |
1355 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
1356 | "auid=%u remove rule from list=%d res=%d", | |
1357 | loginuid, entry->rule.listnr, !err); | |
5d330108 | 1358 | |
93315ed6 | 1359 | audit_free_rule(entry); |
fe7752ba DW |
1360 | break; |
1361 | default: | |
1362 | return -EINVAL; | |
1363 | } | |
1364 | ||
1365 | return err; | |
1366 | } | |
1367 | ||
1368 | int audit_comparator(const u32 left, const u32 op, const u32 right) | |
1369 | { | |
1370 | switch (op) { | |
1371 | case AUDIT_EQUAL: | |
1372 | return (left == right); | |
1373 | case AUDIT_NOT_EQUAL: | |
1374 | return (left != right); | |
1375 | case AUDIT_LESS_THAN: | |
1376 | return (left < right); | |
1377 | case AUDIT_LESS_THAN_OR_EQUAL: | |
1378 | return (left <= right); | |
1379 | case AUDIT_GREATER_THAN: | |
1380 | return (left > right); | |
1381 | case AUDIT_GREATER_THAN_OR_EQUAL: | |
1382 | return (left >= right); | |
fe7752ba | 1383 | } |
d9d9ec6e DK |
1384 | BUG(); |
1385 | return 0; | |
fe7752ba DW |
1386 | } |
1387 | ||
f368c07d AG |
1388 | /* Compare given dentry name with last component in given path, |
1389 | * return of 0 indicates a match. */ | |
9c937dcc AG |
1390 | int audit_compare_dname_path(const char *dname, const char *path, |
1391 | int *dirlen) | |
f368c07d AG |
1392 | { |
1393 | int dlen, plen; | |
1394 | const char *p; | |
1395 | ||
1396 | if (!dname || !path) | |
1397 | return 1; | |
1398 | ||
1399 | dlen = strlen(dname); | |
1400 | plen = strlen(path); | |
1401 | if (plen < dlen) | |
1402 | return 1; | |
1403 | ||
1404 | /* disregard trailing slashes */ | |
1405 | p = path + plen - 1; | |
1406 | while ((*p == '/') && (p > path)) | |
1407 | p--; | |
1408 | ||
1409 | /* find last path component */ | |
1410 | p = p - dlen + 1; | |
1411 | if (p < path) | |
1412 | return 1; | |
1413 | else if (p > path) { | |
1414 | if (*--p != '/') | |
1415 | return 1; | |
1416 | else | |
1417 | p++; | |
1418 | } | |
fe7752ba | 1419 | |
9c937dcc AG |
1420 | /* return length of path's directory component */ |
1421 | if (dirlen) | |
1422 | *dirlen = p - path; | |
f368c07d AG |
1423 | return strncmp(p, dname, dlen); |
1424 | } | |
fe7752ba DW |
1425 | |
1426 | static int audit_filter_user_rules(struct netlink_skb_parms *cb, | |
93315ed6 | 1427 | struct audit_krule *rule, |
fe7752ba DW |
1428 | enum audit_state *state) |
1429 | { | |
1430 | int i; | |
1431 | ||
1432 | for (i = 0; i < rule->field_count; i++) { | |
93315ed6 | 1433 | struct audit_field *f = &rule->fields[i]; |
fe7752ba DW |
1434 | int result = 0; |
1435 | ||
93315ed6 | 1436 | switch (f->type) { |
fe7752ba | 1437 | case AUDIT_PID: |
93315ed6 | 1438 | result = audit_comparator(cb->creds.pid, f->op, f->val); |
fe7752ba DW |
1439 | break; |
1440 | case AUDIT_UID: | |
93315ed6 | 1441 | result = audit_comparator(cb->creds.uid, f->op, f->val); |
fe7752ba DW |
1442 | break; |
1443 | case AUDIT_GID: | |
93315ed6 | 1444 | result = audit_comparator(cb->creds.gid, f->op, f->val); |
fe7752ba DW |
1445 | break; |
1446 | case AUDIT_LOGINUID: | |
93315ed6 | 1447 | result = audit_comparator(cb->loginuid, f->op, f->val); |
fe7752ba DW |
1448 | break; |
1449 | } | |
1450 | ||
1451 | if (!result) | |
1452 | return 0; | |
1453 | } | |
1454 | switch (rule->action) { | |
1455 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; | |
fe7752ba DW |
1456 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; |
1457 | } | |
1458 | return 1; | |
1459 | } | |
1460 | ||
1461 | int audit_filter_user(struct netlink_skb_parms *cb, int type) | |
1462 | { | |
1463 | struct audit_entry *e; | |
1464 | enum audit_state state; | |
1465 | int ret = 1; | |
1466 | ||
1467 | rcu_read_lock(); | |
1468 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { | |
1469 | if (audit_filter_user_rules(cb, &e->rule, &state)) { | |
1470 | if (state == AUDIT_DISABLED) | |
1471 | ret = 0; | |
1472 | break; | |
1473 | } | |
1474 | } | |
1475 | rcu_read_unlock(); | |
1476 | ||
1477 | return ret; /* Audit by default */ | |
1478 | } | |
1479 | ||
1480 | int audit_filter_type(int type) | |
1481 | { | |
1482 | struct audit_entry *e; | |
1483 | int result = 0; | |
1484 | ||
1485 | rcu_read_lock(); | |
1486 | if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE])) | |
1487 | goto unlock_and_return; | |
1488 | ||
1489 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], | |
1490 | list) { | |
fe7752ba | 1491 | int i; |
93315ed6 AG |
1492 | for (i = 0; i < e->rule.field_count; i++) { |
1493 | struct audit_field *f = &e->rule.fields[i]; | |
1494 | if (f->type == AUDIT_MSGTYPE) { | |
1495 | result = audit_comparator(type, f->op, f->val); | |
fe7752ba DW |
1496 | if (!result) |
1497 | break; | |
1498 | } | |
1499 | } | |
1500 | if (result) | |
1501 | goto unlock_and_return; | |
1502 | } | |
1503 | unlock_and_return: | |
1504 | rcu_read_unlock(); | |
1505 | return result; | |
1506 | } | |
3dc7e315 DG |
1507 | |
1508 | /* Check to see if the rule contains any selinux fields. Returns 1 if there | |
1509 | are selinux fields specified in the rule, 0 otherwise. */ | |
1510 | static inline int audit_rule_has_selinux(struct audit_krule *rule) | |
1511 | { | |
1512 | int i; | |
1513 | ||
1514 | for (i = 0; i < rule->field_count; i++) { | |
1515 | struct audit_field *f = &rule->fields[i]; | |
1516 | switch (f->type) { | |
1517 | case AUDIT_SE_USER: | |
1518 | case AUDIT_SE_ROLE: | |
1519 | case AUDIT_SE_TYPE: | |
1520 | case AUDIT_SE_SEN: | |
1521 | case AUDIT_SE_CLR: | |
1522 | return 1; | |
1523 | } | |
1524 | } | |
1525 | ||
1526 | return 0; | |
1527 | } | |
1528 | ||
1529 | /* This function will re-initialize the se_rule field of all applicable rules. | |
1530 | * It will traverse the filter lists serarching for rules that contain selinux | |
1531 | * specific filter fields. When such a rule is found, it is copied, the | |
1532 | * selinux field is re-initialized, and the old rule is replaced with the | |
1533 | * updated rule. */ | |
1534 | int selinux_audit_rule_update(void) | |
1535 | { | |
1536 | struct audit_entry *entry, *n, *nentry; | |
f368c07d | 1537 | struct audit_watch *watch; |
3dc7e315 DG |
1538 | int i, err = 0; |
1539 | ||
f368c07d AG |
1540 | /* audit_filter_mutex synchronizes the writers */ |
1541 | mutex_lock(&audit_filter_mutex); | |
3dc7e315 DG |
1542 | |
1543 | for (i = 0; i < AUDIT_NR_FILTERS; i++) { | |
1544 | list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) { | |
1545 | if (!audit_rule_has_selinux(&entry->rule)) | |
1546 | continue; | |
1547 | ||
f368c07d AG |
1548 | watch = entry->rule.watch; |
1549 | nentry = audit_dupe_rule(&entry->rule, watch); | |
3dc7e315 DG |
1550 | if (unlikely(IS_ERR(nentry))) { |
1551 | /* save the first error encountered for the | |
1552 | * return value */ | |
1553 | if (!err) | |
1554 | err = PTR_ERR(nentry); | |
1555 | audit_panic("error updating selinux filters"); | |
f368c07d AG |
1556 | if (watch) |
1557 | list_del(&entry->rule.rlist); | |
3dc7e315 DG |
1558 | list_del_rcu(&entry->list); |
1559 | } else { | |
f368c07d AG |
1560 | if (watch) { |
1561 | list_add(&nentry->rule.rlist, | |
1562 | &watch->rules); | |
1563 | list_del(&entry->rule.rlist); | |
1564 | } | |
3dc7e315 DG |
1565 | list_replace_rcu(&entry->list, &nentry->list); |
1566 | } | |
1567 | call_rcu(&entry->rcu, audit_free_rule_rcu); | |
1568 | } | |
1569 | } | |
1570 | ||
f368c07d | 1571 | mutex_unlock(&audit_filter_mutex); |
3dc7e315 DG |
1572 | |
1573 | return err; | |
1574 | } | |
f368c07d AG |
1575 | |
1576 | /* Update watch data in audit rules based on inotify events. */ | |
1577 | void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask, | |
1578 | u32 cookie, const char *dname, struct inode *inode) | |
1579 | { | |
1580 | struct audit_parent *parent; | |
1581 | ||
1582 | parent = container_of(i_watch, struct audit_parent, wdata); | |
1583 | ||
1584 | if (mask & (IN_CREATE|IN_MOVED_TO) && inode) | |
1585 | audit_update_watch(parent, dname, inode->i_sb->s_dev, | |
1586 | inode->i_ino, 0); | |
1587 | else if (mask & (IN_DELETE|IN_MOVED_FROM)) | |
1588 | audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1); | |
1589 | /* inotify automatically removes the watch and sends IN_IGNORED */ | |
1590 | else if (mask & (IN_DELETE_SELF|IN_UNMOUNT)) | |
1591 | audit_remove_parent_watches(parent); | |
1592 | /* inotify does not remove the watch, so remove it manually */ | |
1593 | else if(mask & IN_MOVE_SELF) { | |
1594 | audit_remove_parent_watches(parent); | |
1595 | inotify_remove_watch_locked(audit_ih, i_watch); | |
1596 | } else if (mask & IN_IGNORED) | |
1597 | put_inotify_watch(i_watch); | |
1598 | } |