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 | 143 | kfree(e->rule.fields); |
5adc8a6a | 144 | kfree(e->rule.filterkey); |
93315ed6 AG |
145 | kfree(e); |
146 | } | |
147 | ||
148 | static inline void audit_free_rule_rcu(struct rcu_head *head) | |
149 | { | |
150 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); | |
151 | audit_free_rule(e); | |
152 | } | |
153 | ||
f368c07d AG |
154 | /* Initialize a parent watch entry. */ |
155 | static struct audit_parent *audit_init_parent(struct nameidata *ndp) | |
156 | { | |
157 | struct audit_parent *parent; | |
158 | s32 wd; | |
159 | ||
160 | parent = kzalloc(sizeof(*parent), GFP_KERNEL); | |
161 | if (unlikely(!parent)) | |
162 | return ERR_PTR(-ENOMEM); | |
163 | ||
164 | INIT_LIST_HEAD(&parent->watches); | |
165 | parent->flags = 0; | |
166 | ||
167 | inotify_init_watch(&parent->wdata); | |
168 | /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */ | |
169 | get_inotify_watch(&parent->wdata); | |
170 | wd = inotify_add_watch(audit_ih, &parent->wdata, ndp->dentry->d_inode, | |
171 | AUDIT_IN_WATCH); | |
172 | if (wd < 0) { | |
173 | audit_free_parent(&parent->wdata); | |
174 | return ERR_PTR(wd); | |
175 | } | |
176 | ||
177 | return parent; | |
178 | } | |
179 | ||
180 | /* Initialize a watch entry. */ | |
181 | static struct audit_watch *audit_init_watch(char *path) | |
182 | { | |
183 | struct audit_watch *watch; | |
184 | ||
185 | watch = kzalloc(sizeof(*watch), GFP_KERNEL); | |
186 | if (unlikely(!watch)) | |
187 | return ERR_PTR(-ENOMEM); | |
188 | ||
189 | INIT_LIST_HEAD(&watch->rules); | |
190 | atomic_set(&watch->count, 1); | |
191 | watch->path = path; | |
192 | watch->dev = (dev_t)-1; | |
193 | watch->ino = (unsigned long)-1; | |
194 | ||
195 | return watch; | |
196 | } | |
197 | ||
3dc7e315 DG |
198 | /* Initialize an audit filterlist entry. */ |
199 | static inline struct audit_entry *audit_init_entry(u32 field_count) | |
200 | { | |
201 | struct audit_entry *entry; | |
202 | struct audit_field *fields; | |
203 | ||
204 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); | |
205 | if (unlikely(!entry)) | |
206 | return NULL; | |
207 | ||
208 | fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL); | |
209 | if (unlikely(!fields)) { | |
210 | kfree(entry); | |
211 | return NULL; | |
212 | } | |
213 | entry->rule.fields = fields; | |
214 | ||
215 | return entry; | |
216 | } | |
217 | ||
93315ed6 AG |
218 | /* Unpack a filter field's string representation from user-space |
219 | * buffer. */ | |
3dc7e315 | 220 | static char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
93315ed6 AG |
221 | { |
222 | char *str; | |
223 | ||
224 | if (!*bufp || (len == 0) || (len > *remain)) | |
225 | return ERR_PTR(-EINVAL); | |
226 | ||
227 | /* Of the currently implemented string fields, PATH_MAX | |
228 | * defines the longest valid length. | |
229 | */ | |
230 | if (len > PATH_MAX) | |
231 | return ERR_PTR(-ENAMETOOLONG); | |
232 | ||
233 | str = kmalloc(len + 1, GFP_KERNEL); | |
234 | if (unlikely(!str)) | |
235 | return ERR_PTR(-ENOMEM); | |
236 | ||
237 | memcpy(str, *bufp, len); | |
238 | str[len] = 0; | |
239 | *bufp += len; | |
240 | *remain -= len; | |
241 | ||
242 | return str; | |
243 | } | |
244 | ||
f368c07d AG |
245 | /* Translate an inode field to kernel respresentation. */ |
246 | static inline int audit_to_inode(struct audit_krule *krule, | |
247 | struct audit_field *f) | |
248 | { | |
249 | if (krule->listnr != AUDIT_FILTER_EXIT || | |
250 | krule->watch || krule->inode_f) | |
251 | return -EINVAL; | |
252 | ||
253 | krule->inode_f = f; | |
254 | return 0; | |
255 | } | |
256 | ||
257 | /* Translate a watch string to kernel respresentation. */ | |
258 | static int audit_to_watch(struct audit_krule *krule, char *path, int len, | |
259 | u32 op) | |
260 | { | |
261 | struct audit_watch *watch; | |
262 | ||
263 | if (!audit_ih) | |
264 | return -EOPNOTSUPP; | |
265 | ||
266 | if (path[0] != '/' || path[len-1] == '/' || | |
267 | krule->listnr != AUDIT_FILTER_EXIT || | |
268 | op & ~AUDIT_EQUAL || | |
269 | krule->inode_f || krule->watch) /* 1 inode # per rule, for hash */ | |
270 | return -EINVAL; | |
271 | ||
272 | watch = audit_init_watch(path); | |
273 | if (unlikely(IS_ERR(watch))) | |
274 | return PTR_ERR(watch); | |
275 | ||
276 | audit_get_watch(watch); | |
277 | krule->watch = watch; | |
278 | ||
279 | return 0; | |
280 | } | |
281 | ||
93315ed6 AG |
282 | /* Common user-space to kernel rule translation. */ |
283 | static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) | |
284 | { | |
285 | unsigned listnr; | |
286 | struct audit_entry *entry; | |
93315ed6 AG |
287 | int i, err; |
288 | ||
289 | err = -EINVAL; | |
290 | listnr = rule->flags & ~AUDIT_FILTER_PREPEND; | |
291 | switch(listnr) { | |
292 | default: | |
293 | goto exit_err; | |
294 | case AUDIT_FILTER_USER: | |
295 | case AUDIT_FILTER_TYPE: | |
296 | #ifdef CONFIG_AUDITSYSCALL | |
297 | case AUDIT_FILTER_ENTRY: | |
298 | case AUDIT_FILTER_EXIT: | |
299 | case AUDIT_FILTER_TASK: | |
300 | #endif | |
301 | ; | |
302 | } | |
014149cc AV |
303 | if (unlikely(rule->action == AUDIT_POSSIBLE)) { |
304 | printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n"); | |
305 | goto exit_err; | |
306 | } | |
307 | if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS) | |
93315ed6 AG |
308 | goto exit_err; |
309 | if (rule->field_count > AUDIT_MAX_FIELDS) | |
310 | goto exit_err; | |
311 | ||
312 | err = -ENOMEM; | |
3dc7e315 DG |
313 | entry = audit_init_entry(rule->field_count); |
314 | if (!entry) | |
93315ed6 | 315 | goto exit_err; |
93315ed6 AG |
316 | |
317 | entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; | |
318 | entry->rule.listnr = listnr; | |
319 | entry->rule.action = rule->action; | |
320 | entry->rule.field_count = rule->field_count; | |
93315ed6 AG |
321 | |
322 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
323 | entry->rule.mask[i] = rule->mask[i]; | |
324 | ||
325 | return entry; | |
326 | ||
327 | exit_err: | |
328 | return ERR_PTR(err); | |
329 | } | |
330 | ||
331 | /* Translate struct audit_rule to kernel's rule respresentation. | |
332 | * Exists for backward compatibility with userspace. */ | |
333 | static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) | |
334 | { | |
335 | struct audit_entry *entry; | |
f368c07d | 336 | struct audit_field *f; |
93315ed6 | 337 | int err = 0; |
fe7752ba DW |
338 | int i; |
339 | ||
93315ed6 AG |
340 | entry = audit_to_entry_common(rule); |
341 | if (IS_ERR(entry)) | |
342 | goto exit_nofree; | |
343 | ||
344 | for (i = 0; i < rule->field_count; i++) { | |
345 | struct audit_field *f = &entry->rule.fields[i]; | |
346 | ||
93315ed6 AG |
347 | f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS); |
348 | f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS); | |
349 | f->val = rule->values[i]; | |
350 | ||
f368c07d | 351 | err = -EINVAL; |
f368c07d | 352 | switch(f->type) { |
0a73dccc | 353 | default: |
3dc7e315 | 354 | goto exit_free; |
0a73dccc AV |
355 | case AUDIT_PID: |
356 | case AUDIT_UID: | |
357 | case AUDIT_EUID: | |
358 | case AUDIT_SUID: | |
359 | case AUDIT_FSUID: | |
360 | case AUDIT_GID: | |
361 | case AUDIT_EGID: | |
362 | case AUDIT_SGID: | |
363 | case AUDIT_FSGID: | |
364 | case AUDIT_LOGINUID: | |
365 | case AUDIT_PERS: | |
366 | case AUDIT_ARCH: | |
367 | case AUDIT_MSGTYPE: | |
368 | case AUDIT_DEVMAJOR: | |
369 | case AUDIT_DEVMINOR: | |
370 | case AUDIT_EXIT: | |
371 | case AUDIT_SUCCESS: | |
372 | case AUDIT_ARG0: | |
373 | case AUDIT_ARG1: | |
374 | case AUDIT_ARG2: | |
375 | case AUDIT_ARG3: | |
376 | break; | |
f368c07d AG |
377 | case AUDIT_INODE: |
378 | err = audit_to_inode(&entry->rule, f); | |
379 | if (err) | |
380 | goto exit_free; | |
381 | break; | |
3dc7e315 DG |
382 | } |
383 | ||
93315ed6 | 384 | entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1; |
d9d9ec6e DK |
385 | |
386 | /* Support for legacy operators where | |
387 | * AUDIT_NEGATE bit signifies != and otherwise assumes == */ | |
93315ed6 | 388 | if (f->op & AUDIT_NEGATE) |
d9d9ec6e DK |
389 | f->op = AUDIT_NOT_EQUAL; |
390 | else if (!f->op) | |
391 | f->op = AUDIT_EQUAL; | |
392 | else if (f->op == AUDIT_OPERATORS) { | |
393 | err = -EINVAL; | |
394 | goto exit_free; | |
395 | } | |
fe7752ba | 396 | } |
93315ed6 | 397 | |
f368c07d AG |
398 | f = entry->rule.inode_f; |
399 | if (f) { | |
400 | switch(f->op) { | |
401 | case AUDIT_NOT_EQUAL: | |
402 | entry->rule.inode_f = NULL; | |
403 | case AUDIT_EQUAL: | |
404 | break; | |
405 | default: | |
406 | goto exit_free; | |
407 | } | |
408 | } | |
409 | ||
93315ed6 AG |
410 | exit_nofree: |
411 | return entry; | |
412 | ||
413 | exit_free: | |
414 | audit_free_rule(entry); | |
415 | return ERR_PTR(err); | |
fe7752ba DW |
416 | } |
417 | ||
93315ed6 AG |
418 | /* Translate struct audit_rule_data to kernel's rule respresentation. */ |
419 | static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, | |
420 | size_t datasz) | |
fe7752ba | 421 | { |
93315ed6 AG |
422 | int err = 0; |
423 | struct audit_entry *entry; | |
f368c07d | 424 | struct audit_field *f; |
93315ed6 | 425 | void *bufp; |
3dc7e315 | 426 | size_t remain = datasz - sizeof(struct audit_rule_data); |
fe7752ba | 427 | int i; |
3dc7e315 | 428 | char *str; |
fe7752ba | 429 | |
93315ed6 AG |
430 | entry = audit_to_entry_common((struct audit_rule *)data); |
431 | if (IS_ERR(entry)) | |
432 | goto exit_nofree; | |
fe7752ba | 433 | |
93315ed6 AG |
434 | bufp = data->buf; |
435 | entry->rule.vers_ops = 2; | |
436 | for (i = 0; i < data->field_count; i++) { | |
437 | struct audit_field *f = &entry->rule.fields[i]; | |
438 | ||
439 | err = -EINVAL; | |
440 | if (!(data->fieldflags[i] & AUDIT_OPERATORS) || | |
441 | data->fieldflags[i] & ~AUDIT_OPERATORS) | |
442 | goto exit_free; | |
443 | ||
444 | f->op = data->fieldflags[i] & AUDIT_OPERATORS; | |
445 | f->type = data->fields[i]; | |
3dc7e315 DG |
446 | f->val = data->values[i]; |
447 | f->se_str = NULL; | |
448 | f->se_rule = NULL; | |
93315ed6 | 449 | switch(f->type) { |
0a73dccc AV |
450 | case AUDIT_PID: |
451 | case AUDIT_UID: | |
452 | case AUDIT_EUID: | |
453 | case AUDIT_SUID: | |
454 | case AUDIT_FSUID: | |
455 | case AUDIT_GID: | |
456 | case AUDIT_EGID: | |
457 | case AUDIT_SGID: | |
458 | case AUDIT_FSGID: | |
459 | case AUDIT_LOGINUID: | |
460 | case AUDIT_PERS: | |
461 | case AUDIT_ARCH: | |
462 | case AUDIT_MSGTYPE: | |
463 | case AUDIT_PPID: | |
464 | case AUDIT_DEVMAJOR: | |
465 | case AUDIT_DEVMINOR: | |
466 | case AUDIT_EXIT: | |
467 | case AUDIT_SUCCESS: | |
468 | case AUDIT_ARG0: | |
469 | case AUDIT_ARG1: | |
470 | case AUDIT_ARG2: | |
471 | case AUDIT_ARG3: | |
472 | break; | |
3dc7e315 DG |
473 | case AUDIT_SE_USER: |
474 | case AUDIT_SE_ROLE: | |
475 | case AUDIT_SE_TYPE: | |
476 | case AUDIT_SE_SEN: | |
477 | case AUDIT_SE_CLR: | |
478 | str = audit_unpack_string(&bufp, &remain, f->val); | |
479 | if (IS_ERR(str)) | |
480 | goto exit_free; | |
481 | entry->rule.buflen += f->val; | |
482 | ||
483 | err = selinux_audit_rule_init(f->type, f->op, str, | |
484 | &f->se_rule); | |
485 | /* Keep currently invalid fields around in case they | |
486 | * become valid after a policy reload. */ | |
487 | if (err == -EINVAL) { | |
488 | printk(KERN_WARNING "audit rule for selinux " | |
489 | "\'%s\' is invalid\n", str); | |
490 | err = 0; | |
491 | } | |
492 | if (err) { | |
493 | kfree(str); | |
494 | goto exit_free; | |
495 | } else | |
496 | f->se_str = str; | |
497 | break; | |
f368c07d AG |
498 | case AUDIT_WATCH: |
499 | str = audit_unpack_string(&bufp, &remain, f->val); | |
500 | if (IS_ERR(str)) | |
501 | goto exit_free; | |
502 | entry->rule.buflen += f->val; | |
503 | ||
504 | err = audit_to_watch(&entry->rule, str, f->val, f->op); | |
505 | if (err) { | |
506 | kfree(str); | |
507 | goto exit_free; | |
508 | } | |
509 | break; | |
510 | case AUDIT_INODE: | |
511 | err = audit_to_inode(&entry->rule, f); | |
512 | if (err) | |
513 | goto exit_free; | |
514 | break; | |
5adc8a6a AG |
515 | case AUDIT_FILTERKEY: |
516 | err = -EINVAL; | |
517 | if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN) | |
518 | goto exit_free; | |
519 | str = audit_unpack_string(&bufp, &remain, f->val); | |
520 | if (IS_ERR(str)) | |
521 | goto exit_free; | |
522 | entry->rule.buflen += f->val; | |
523 | entry->rule.filterkey = str; | |
524 | break; | |
0a73dccc AV |
525 | default: |
526 | goto exit_free; | |
f368c07d AG |
527 | } |
528 | } | |
529 | ||
530 | f = entry->rule.inode_f; | |
531 | if (f) { | |
532 | switch(f->op) { | |
533 | case AUDIT_NOT_EQUAL: | |
534 | entry->rule.inode_f = NULL; | |
535 | case AUDIT_EQUAL: | |
536 | break; | |
537 | default: | |
538 | goto exit_free; | |
93315ed6 AG |
539 | } |
540 | } | |
541 | ||
542 | exit_nofree: | |
543 | return entry; | |
544 | ||
545 | exit_free: | |
546 | audit_free_rule(entry); | |
547 | return ERR_PTR(err); | |
548 | } | |
549 | ||
550 | /* Pack a filter field's string representation into data block. */ | |
551 | static inline size_t audit_pack_string(void **bufp, char *str) | |
552 | { | |
553 | size_t len = strlen(str); | |
554 | ||
555 | memcpy(*bufp, str, len); | |
556 | *bufp += len; | |
557 | ||
558 | return len; | |
559 | } | |
560 | ||
561 | /* Translate kernel rule respresentation to struct audit_rule. | |
562 | * Exists for backward compatibility with userspace. */ | |
563 | static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule) | |
564 | { | |
565 | struct audit_rule *rule; | |
566 | int i; | |
567 | ||
568 | rule = kmalloc(sizeof(*rule), GFP_KERNEL); | |
569 | if (unlikely(!rule)) | |
0a3b483e | 570 | return NULL; |
93315ed6 AG |
571 | memset(rule, 0, sizeof(*rule)); |
572 | ||
573 | rule->flags = krule->flags | krule->listnr; | |
574 | rule->action = krule->action; | |
575 | rule->field_count = krule->field_count; | |
576 | for (i = 0; i < rule->field_count; i++) { | |
577 | rule->values[i] = krule->fields[i].val; | |
578 | rule->fields[i] = krule->fields[i].type; | |
579 | ||
580 | if (krule->vers_ops == 1) { | |
581 | if (krule->fields[i].op & AUDIT_NOT_EQUAL) | |
582 | rule->fields[i] |= AUDIT_NEGATE; | |
583 | } else { | |
584 | rule->fields[i] |= krule->fields[i].op; | |
585 | } | |
586 | } | |
587 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i]; | |
588 | ||
589 | return rule; | |
590 | } | |
fe7752ba | 591 | |
93315ed6 AG |
592 | /* Translate kernel rule respresentation to struct audit_rule_data. */ |
593 | static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) | |
594 | { | |
595 | struct audit_rule_data *data; | |
596 | void *bufp; | |
597 | int i; | |
598 | ||
599 | data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); | |
600 | if (unlikely(!data)) | |
0a3b483e | 601 | return NULL; |
93315ed6 AG |
602 | memset(data, 0, sizeof(*data)); |
603 | ||
604 | data->flags = krule->flags | krule->listnr; | |
605 | data->action = krule->action; | |
606 | data->field_count = krule->field_count; | |
607 | bufp = data->buf; | |
608 | for (i = 0; i < data->field_count; i++) { | |
609 | struct audit_field *f = &krule->fields[i]; | |
610 | ||
611 | data->fields[i] = f->type; | |
612 | data->fieldflags[i] = f->op; | |
613 | switch(f->type) { | |
3dc7e315 DG |
614 | case AUDIT_SE_USER: |
615 | case AUDIT_SE_ROLE: | |
616 | case AUDIT_SE_TYPE: | |
617 | case AUDIT_SE_SEN: | |
618 | case AUDIT_SE_CLR: | |
619 | data->buflen += data->values[i] = | |
620 | audit_pack_string(&bufp, f->se_str); | |
621 | break; | |
f368c07d AG |
622 | case AUDIT_WATCH: |
623 | data->buflen += data->values[i] = | |
624 | audit_pack_string(&bufp, krule->watch->path); | |
625 | break; | |
5adc8a6a AG |
626 | case AUDIT_FILTERKEY: |
627 | data->buflen += data->values[i] = | |
628 | audit_pack_string(&bufp, krule->filterkey); | |
629 | break; | |
93315ed6 AG |
630 | default: |
631 | data->values[i] = f->val; | |
632 | } | |
633 | } | |
634 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; | |
635 | ||
636 | return data; | |
637 | } | |
638 | ||
639 | /* Compare two rules in kernel format. Considered success if rules | |
640 | * don't match. */ | |
641 | static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) | |
642 | { | |
643 | int i; | |
644 | ||
645 | if (a->flags != b->flags || | |
646 | a->listnr != b->listnr || | |
647 | a->action != b->action || | |
648 | a->field_count != b->field_count) | |
fe7752ba DW |
649 | return 1; |
650 | ||
651 | for (i = 0; i < a->field_count; i++) { | |
93315ed6 AG |
652 | if (a->fields[i].type != b->fields[i].type || |
653 | a->fields[i].op != b->fields[i].op) | |
fe7752ba | 654 | return 1; |
93315ed6 AG |
655 | |
656 | switch(a->fields[i].type) { | |
3dc7e315 DG |
657 | case AUDIT_SE_USER: |
658 | case AUDIT_SE_ROLE: | |
659 | case AUDIT_SE_TYPE: | |
660 | case AUDIT_SE_SEN: | |
661 | case AUDIT_SE_CLR: | |
662 | if (strcmp(a->fields[i].se_str, b->fields[i].se_str)) | |
663 | return 1; | |
664 | break; | |
f368c07d AG |
665 | case AUDIT_WATCH: |
666 | if (strcmp(a->watch->path, b->watch->path)) | |
667 | return 1; | |
668 | break; | |
5adc8a6a AG |
669 | case AUDIT_FILTERKEY: |
670 | /* both filterkeys exist based on above type compare */ | |
671 | if (strcmp(a->filterkey, b->filterkey)) | |
672 | return 1; | |
673 | break; | |
93315ed6 AG |
674 | default: |
675 | if (a->fields[i].val != b->fields[i].val) | |
676 | return 1; | |
677 | } | |
fe7752ba DW |
678 | } |
679 | ||
680 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
681 | if (a->mask[i] != b->mask[i]) | |
682 | return 1; | |
683 | ||
684 | return 0; | |
685 | } | |
686 | ||
f368c07d AG |
687 | /* Duplicate the given audit watch. The new watch's rules list is initialized |
688 | * to an empty list and wlist is undefined. */ | |
689 | static struct audit_watch *audit_dupe_watch(struct audit_watch *old) | |
690 | { | |
691 | char *path; | |
692 | struct audit_watch *new; | |
693 | ||
694 | path = kstrdup(old->path, GFP_KERNEL); | |
695 | if (unlikely(!path)) | |
696 | return ERR_PTR(-ENOMEM); | |
697 | ||
698 | new = audit_init_watch(path); | |
699 | if (unlikely(IS_ERR(new))) { | |
700 | kfree(path); | |
701 | goto out; | |
702 | } | |
703 | ||
704 | new->dev = old->dev; | |
705 | new->ino = old->ino; | |
706 | get_inotify_watch(&old->parent->wdata); | |
707 | new->parent = old->parent; | |
708 | ||
709 | out: | |
710 | return new; | |
711 | } | |
712 | ||
3dc7e315 DG |
713 | /* Duplicate selinux field information. The se_rule is opaque, so must be |
714 | * re-initialized. */ | |
715 | static inline int audit_dupe_selinux_field(struct audit_field *df, | |
716 | struct audit_field *sf) | |
717 | { | |
718 | int ret = 0; | |
719 | char *se_str; | |
720 | ||
721 | /* our own copy of se_str */ | |
722 | se_str = kstrdup(sf->se_str, GFP_KERNEL); | |
723 | if (unlikely(IS_ERR(se_str))) | |
724 | return -ENOMEM; | |
725 | df->se_str = se_str; | |
726 | ||
727 | /* our own (refreshed) copy of se_rule */ | |
728 | ret = selinux_audit_rule_init(df->type, df->op, df->se_str, | |
729 | &df->se_rule); | |
730 | /* Keep currently invalid fields around in case they | |
731 | * become valid after a policy reload. */ | |
732 | if (ret == -EINVAL) { | |
733 | printk(KERN_WARNING "audit rule for selinux \'%s\' is " | |
734 | "invalid\n", df->se_str); | |
735 | ret = 0; | |
736 | } | |
737 | ||
738 | return ret; | |
739 | } | |
740 | ||
741 | /* Duplicate an audit rule. This will be a deep copy with the exception | |
742 | * of the watch - that pointer is carried over. The selinux specific fields | |
743 | * will be updated in the copy. The point is to be able to replace the old | |
f368c07d AG |
744 | * rule with the new rule in the filterlist, then free the old rule. |
745 | * The rlist element is undefined; list manipulations are handled apart from | |
746 | * the initial copy. */ | |
747 | static struct audit_entry *audit_dupe_rule(struct audit_krule *old, | |
748 | struct audit_watch *watch) | |
3dc7e315 DG |
749 | { |
750 | u32 fcount = old->field_count; | |
751 | struct audit_entry *entry; | |
752 | struct audit_krule *new; | |
5adc8a6a | 753 | char *fk; |
3dc7e315 DG |
754 | int i, err = 0; |
755 | ||
756 | entry = audit_init_entry(fcount); | |
757 | if (unlikely(!entry)) | |
758 | return ERR_PTR(-ENOMEM); | |
759 | ||
760 | new = &entry->rule; | |
761 | new->vers_ops = old->vers_ops; | |
762 | new->flags = old->flags; | |
763 | new->listnr = old->listnr; | |
764 | new->action = old->action; | |
765 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
766 | new->mask[i] = old->mask[i]; | |
767 | new->buflen = old->buflen; | |
f368c07d AG |
768 | new->inode_f = old->inode_f; |
769 | new->watch = NULL; | |
3dc7e315 DG |
770 | new->field_count = old->field_count; |
771 | memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); | |
772 | ||
773 | /* deep copy this information, updating the se_rule fields, because | |
774 | * the originals will all be freed when the old rule is freed. */ | |
775 | for (i = 0; i < fcount; i++) { | |
776 | switch (new->fields[i].type) { | |
777 | case AUDIT_SE_USER: | |
778 | case AUDIT_SE_ROLE: | |
779 | case AUDIT_SE_TYPE: | |
780 | case AUDIT_SE_SEN: | |
781 | case AUDIT_SE_CLR: | |
782 | err = audit_dupe_selinux_field(&new->fields[i], | |
783 | &old->fields[i]); | |
5adc8a6a AG |
784 | break; |
785 | case AUDIT_FILTERKEY: | |
786 | fk = kstrdup(old->filterkey, GFP_KERNEL); | |
787 | if (unlikely(!fk)) | |
788 | err = -ENOMEM; | |
789 | else | |
790 | new->filterkey = fk; | |
3dc7e315 DG |
791 | } |
792 | if (err) { | |
793 | audit_free_rule(entry); | |
794 | return ERR_PTR(err); | |
795 | } | |
796 | } | |
797 | ||
f368c07d AG |
798 | if (watch) { |
799 | audit_get_watch(watch); | |
800 | new->watch = watch; | |
801 | } | |
802 | ||
3dc7e315 DG |
803 | return entry; |
804 | } | |
805 | ||
f368c07d AG |
806 | /* Update inode info in audit rules based on filesystem event. */ |
807 | static void audit_update_watch(struct audit_parent *parent, | |
808 | const char *dname, dev_t dev, | |
809 | unsigned long ino, unsigned invalidating) | |
810 | { | |
811 | struct audit_watch *owatch, *nwatch, *nextw; | |
812 | struct audit_krule *r, *nextr; | |
813 | struct audit_entry *oentry, *nentry; | |
814 | struct audit_buffer *ab; | |
815 | ||
816 | mutex_lock(&audit_filter_mutex); | |
817 | list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) { | |
9c937dcc | 818 | if (audit_compare_dname_path(dname, owatch->path, NULL)) |
f368c07d AG |
819 | continue; |
820 | ||
821 | /* If the update involves invalidating rules, do the inode-based | |
822 | * filtering now, so we don't omit records. */ | |
823 | if (invalidating && | |
824 | audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT) | |
825 | audit_set_auditable(current->audit_context); | |
826 | ||
827 | nwatch = audit_dupe_watch(owatch); | |
828 | if (unlikely(IS_ERR(nwatch))) { | |
829 | mutex_unlock(&audit_filter_mutex); | |
830 | audit_panic("error updating watch, skipping"); | |
831 | return; | |
832 | } | |
833 | nwatch->dev = dev; | |
834 | nwatch->ino = ino; | |
835 | ||
836 | list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) { | |
837 | ||
838 | oentry = container_of(r, struct audit_entry, rule); | |
839 | list_del(&oentry->rule.rlist); | |
840 | list_del_rcu(&oentry->list); | |
841 | ||
842 | nentry = audit_dupe_rule(&oentry->rule, nwatch); | |
843 | if (unlikely(IS_ERR(nentry))) | |
844 | audit_panic("error updating watch, removing"); | |
845 | else { | |
846 | int h = audit_hash_ino((u32)ino); | |
847 | list_add(&nentry->rule.rlist, &nwatch->rules); | |
848 | list_add_rcu(&nentry->list, &audit_inode_hash[h]); | |
849 | } | |
850 | ||
851 | call_rcu(&oentry->rcu, audit_free_rule_rcu); | |
852 | } | |
853 | ||
854 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); | |
855 | audit_log_format(ab, "audit updated rules specifying watch="); | |
856 | audit_log_untrustedstring(ab, owatch->path); | |
857 | audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino); | |
858 | audit_log_end(ab); | |
859 | ||
860 | audit_remove_watch(owatch); | |
861 | goto add_watch_to_parent; /* event applies to a single watch */ | |
862 | } | |
863 | mutex_unlock(&audit_filter_mutex); | |
864 | return; | |
865 | ||
866 | add_watch_to_parent: | |
867 | list_add(&nwatch->wlist, &parent->watches); | |
868 | mutex_unlock(&audit_filter_mutex); | |
869 | return; | |
870 | } | |
871 | ||
872 | /* Remove all watches & rules associated with a parent that is going away. */ | |
873 | static void audit_remove_parent_watches(struct audit_parent *parent) | |
874 | { | |
875 | struct audit_watch *w, *nextw; | |
876 | struct audit_krule *r, *nextr; | |
877 | struct audit_entry *e; | |
878 | ||
879 | mutex_lock(&audit_filter_mutex); | |
880 | parent->flags |= AUDIT_PARENT_INVALID; | |
881 | list_for_each_entry_safe(w, nextw, &parent->watches, wlist) { | |
882 | list_for_each_entry_safe(r, nextr, &w->rules, rlist) { | |
883 | e = container_of(r, struct audit_entry, rule); | |
884 | list_del(&r->rlist); | |
885 | list_del_rcu(&e->list); | |
886 | call_rcu(&e->rcu, audit_free_rule_rcu); | |
887 | ||
888 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
889 | "audit implicitly removed rule from list=%d\n", | |
890 | AUDIT_FILTER_EXIT); | |
891 | } | |
892 | audit_remove_watch(w); | |
893 | } | |
894 | mutex_unlock(&audit_filter_mutex); | |
895 | } | |
896 | ||
897 | /* Unregister inotify watches for parents on in_list. | |
898 | * Generates an IN_IGNORED event. */ | |
899 | static void audit_inotify_unregister(struct list_head *in_list) | |
900 | { | |
901 | struct audit_parent *p, *n; | |
902 | ||
903 | list_for_each_entry_safe(p, n, in_list, ilist) { | |
904 | list_del(&p->ilist); | |
905 | inotify_rm_watch(audit_ih, &p->wdata); | |
906 | /* the put matching the get in audit_do_del_rule() */ | |
907 | put_inotify_watch(&p->wdata); | |
908 | } | |
909 | } | |
910 | ||
911 | /* Find an existing audit rule. | |
912 | * Caller must hold audit_filter_mutex to prevent stale rule data. */ | |
913 | static struct audit_entry *audit_find_rule(struct audit_entry *entry, | |
914 | struct list_head *list) | |
915 | { | |
916 | struct audit_entry *e, *found = NULL; | |
917 | int h; | |
918 | ||
919 | if (entry->rule.watch) { | |
920 | /* we don't know the inode number, so must walk entire hash */ | |
921 | for (h = 0; h < AUDIT_INODE_BUCKETS; h++) { | |
922 | list = &audit_inode_hash[h]; | |
923 | list_for_each_entry(e, list, list) | |
924 | if (!audit_compare_rule(&entry->rule, &e->rule)) { | |
925 | found = e; | |
926 | goto out; | |
927 | } | |
928 | } | |
929 | goto out; | |
930 | } | |
931 | ||
932 | list_for_each_entry(e, list, list) | |
933 | if (!audit_compare_rule(&entry->rule, &e->rule)) { | |
934 | found = e; | |
935 | goto out; | |
936 | } | |
937 | ||
938 | out: | |
939 | return found; | |
940 | } | |
941 | ||
942 | /* Get path information necessary for adding watches. */ | |
943 | static int audit_get_nd(char *path, struct nameidata **ndp, | |
944 | struct nameidata **ndw) | |
945 | { | |
946 | struct nameidata *ndparent, *ndwatch; | |
947 | int err; | |
948 | ||
949 | ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL); | |
950 | if (unlikely(!ndparent)) | |
951 | return -ENOMEM; | |
952 | ||
953 | ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL); | |
954 | if (unlikely(!ndwatch)) { | |
955 | kfree(ndparent); | |
956 | return -ENOMEM; | |
957 | } | |
958 | ||
959 | err = path_lookup(path, LOOKUP_PARENT, ndparent); | |
960 | if (err) { | |
961 | kfree(ndparent); | |
962 | kfree(ndwatch); | |
963 | return err; | |
964 | } | |
965 | ||
966 | err = path_lookup(path, 0, ndwatch); | |
967 | if (err) { | |
968 | kfree(ndwatch); | |
969 | ndwatch = NULL; | |
970 | } | |
971 | ||
972 | *ndp = ndparent; | |
973 | *ndw = ndwatch; | |
974 | ||
975 | return 0; | |
976 | } | |
977 | ||
978 | /* Release resources used for watch path information. */ | |
979 | static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw) | |
980 | { | |
981 | if (ndp) { | |
982 | path_release(ndp); | |
983 | kfree(ndp); | |
984 | } | |
985 | if (ndw) { | |
986 | path_release(ndw); | |
987 | kfree(ndw); | |
988 | } | |
989 | } | |
990 | ||
991 | /* Associate the given rule with an existing parent inotify_watch. | |
992 | * Caller must hold audit_filter_mutex. */ | |
993 | static void audit_add_to_parent(struct audit_krule *krule, | |
994 | struct audit_parent *parent) | |
995 | { | |
996 | struct audit_watch *w, *watch = krule->watch; | |
997 | int watch_found = 0; | |
998 | ||
999 | list_for_each_entry(w, &parent->watches, wlist) { | |
1000 | if (strcmp(watch->path, w->path)) | |
1001 | continue; | |
1002 | ||
1003 | watch_found = 1; | |
1004 | ||
1005 | /* put krule's and initial refs to temporary watch */ | |
1006 | audit_put_watch(watch); | |
1007 | audit_put_watch(watch); | |
1008 | ||
1009 | audit_get_watch(w); | |
1010 | krule->watch = watch = w; | |
1011 | break; | |
1012 | } | |
1013 | ||
1014 | if (!watch_found) { | |
1015 | get_inotify_watch(&parent->wdata); | |
1016 | watch->parent = parent; | |
1017 | ||
1018 | list_add(&watch->wlist, &parent->watches); | |
1019 | } | |
1020 | list_add(&krule->rlist, &watch->rules); | |
1021 | } | |
1022 | ||
1023 | /* Find a matching watch entry, or add this one. | |
1024 | * Caller must hold audit_filter_mutex. */ | |
1025 | static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp, | |
1026 | struct nameidata *ndw) | |
1027 | { | |
1028 | struct audit_watch *watch = krule->watch; | |
1029 | struct inotify_watch *i_watch; | |
1030 | struct audit_parent *parent; | |
1031 | int ret = 0; | |
1032 | ||
1033 | /* update watch filter fields */ | |
1034 | if (ndw) { | |
1035 | watch->dev = ndw->dentry->d_inode->i_sb->s_dev; | |
1036 | watch->ino = ndw->dentry->d_inode->i_ino; | |
1037 | } | |
1038 | ||
1039 | /* The audit_filter_mutex must not be held during inotify calls because | |
1040 | * we hold it during inotify event callback processing. If an existing | |
1041 | * inotify watch is found, inotify_find_watch() grabs a reference before | |
1042 | * returning. | |
1043 | */ | |
1044 | mutex_unlock(&audit_filter_mutex); | |
1045 | ||
1046 | if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) { | |
1047 | parent = audit_init_parent(ndp); | |
1048 | if (IS_ERR(parent)) { | |
1049 | /* caller expects mutex locked */ | |
1050 | mutex_lock(&audit_filter_mutex); | |
1051 | return PTR_ERR(parent); | |
1052 | } | |
1053 | } else | |
1054 | parent = container_of(i_watch, struct audit_parent, wdata); | |
1055 | ||
1056 | mutex_lock(&audit_filter_mutex); | |
1057 | ||
1058 | /* parent was moved before we took audit_filter_mutex */ | |
1059 | if (parent->flags & AUDIT_PARENT_INVALID) | |
1060 | ret = -ENOENT; | |
1061 | else | |
1062 | audit_add_to_parent(krule, parent); | |
1063 | ||
1064 | /* match get in audit_init_parent or inotify_find_watch */ | |
1065 | put_inotify_watch(&parent->wdata); | |
1066 | return ret; | |
1067 | } | |
1068 | ||
1069 | /* Add rule to given filterlist if not a duplicate. */ | |
93315ed6 | 1070 | static inline int audit_add_rule(struct audit_entry *entry, |
f368c07d | 1071 | struct list_head *list) |
fe7752ba | 1072 | { |
93315ed6 | 1073 | struct audit_entry *e; |
f368c07d AG |
1074 | struct audit_field *inode_f = entry->rule.inode_f; |
1075 | struct audit_watch *watch = entry->rule.watch; | |
1076 | struct nameidata *ndp, *ndw; | |
1077 | int h, err, putnd_needed = 0; | |
1078 | ||
1079 | if (inode_f) { | |
1080 | h = audit_hash_ino(inode_f->val); | |
1081 | list = &audit_inode_hash[h]; | |
1082 | } | |
1083 | ||
1084 | mutex_lock(&audit_filter_mutex); | |
1085 | e = audit_find_rule(entry, list); | |
1086 | mutex_unlock(&audit_filter_mutex); | |
1087 | if (e) { | |
1088 | err = -EEXIST; | |
1089 | goto error; | |
1090 | } | |
fe7752ba | 1091 | |
f368c07d AG |
1092 | /* Avoid calling path_lookup under audit_filter_mutex. */ |
1093 | if (watch) { | |
1094 | err = audit_get_nd(watch->path, &ndp, &ndw); | |
1095 | if (err) | |
1096 | goto error; | |
1097 | putnd_needed = 1; | |
1098 | } | |
1099 | ||
1100 | mutex_lock(&audit_filter_mutex); | |
1101 | if (watch) { | |
1102 | /* audit_filter_mutex is dropped and re-taken during this call */ | |
1103 | err = audit_add_watch(&entry->rule, ndp, ndw); | |
1104 | if (err) { | |
1105 | mutex_unlock(&audit_filter_mutex); | |
1106 | goto error; | |
1107 | } | |
1108 | h = audit_hash_ino((u32)watch->ino); | |
1109 | list = &audit_inode_hash[h]; | |
fe7752ba DW |
1110 | } |
1111 | ||
fe7752ba | 1112 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
fe7752ba | 1113 | list_add_rcu(&entry->list, list); |
6a2bceec | 1114 | entry->rule.flags &= ~AUDIT_FILTER_PREPEND; |
fe7752ba DW |
1115 | } else { |
1116 | list_add_tail_rcu(&entry->list, list); | |
1117 | } | |
f368c07d | 1118 | mutex_unlock(&audit_filter_mutex); |
fe7752ba | 1119 | |
f368c07d AG |
1120 | if (putnd_needed) |
1121 | audit_put_nd(ndp, ndw); | |
1122 | ||
1123 | return 0; | |
1124 | ||
1125 | error: | |
1126 | if (putnd_needed) | |
1127 | audit_put_nd(ndp, ndw); | |
1128 | if (watch) | |
1129 | audit_put_watch(watch); /* tmp watch, matches initial get */ | |
1130 | return err; | |
fe7752ba DW |
1131 | } |
1132 | ||
f368c07d | 1133 | /* Remove an existing rule from filterlist. */ |
93315ed6 | 1134 | static inline int audit_del_rule(struct audit_entry *entry, |
fe7752ba DW |
1135 | struct list_head *list) |
1136 | { | |
1137 | struct audit_entry *e; | |
f368c07d AG |
1138 | struct audit_field *inode_f = entry->rule.inode_f; |
1139 | struct audit_watch *watch, *tmp_watch = entry->rule.watch; | |
1140 | LIST_HEAD(inotify_list); | |
1141 | int h, ret = 0; | |
1142 | ||
1143 | if (inode_f) { | |
1144 | h = audit_hash_ino(inode_f->val); | |
1145 | list = &audit_inode_hash[h]; | |
1146 | } | |
fe7752ba | 1147 | |
f368c07d AG |
1148 | mutex_lock(&audit_filter_mutex); |
1149 | e = audit_find_rule(entry, list); | |
1150 | if (!e) { | |
1151 | mutex_unlock(&audit_filter_mutex); | |
1152 | ret = -ENOENT; | |
1153 | goto out; | |
1154 | } | |
1155 | ||
1156 | watch = e->rule.watch; | |
1157 | if (watch) { | |
1158 | struct audit_parent *parent = watch->parent; | |
1159 | ||
1160 | list_del(&e->rule.rlist); | |
1161 | ||
1162 | if (list_empty(&watch->rules)) { | |
1163 | audit_remove_watch(watch); | |
1164 | ||
1165 | if (list_empty(&parent->watches)) { | |
1166 | /* Put parent on the inotify un-registration | |
1167 | * list. Grab a reference before releasing | |
1168 | * audit_filter_mutex, to be released in | |
1169 | * audit_inotify_unregister(). */ | |
1170 | list_add(&parent->ilist, &inotify_list); | |
1171 | get_inotify_watch(&parent->wdata); | |
1172 | } | |
fe7752ba DW |
1173 | } |
1174 | } | |
f368c07d AG |
1175 | |
1176 | list_del_rcu(&e->list); | |
1177 | call_rcu(&e->rcu, audit_free_rule_rcu); | |
1178 | ||
1179 | mutex_unlock(&audit_filter_mutex); | |
1180 | ||
1181 | if (!list_empty(&inotify_list)) | |
1182 | audit_inotify_unregister(&inotify_list); | |
1183 | ||
1184 | out: | |
1185 | if (tmp_watch) | |
1186 | audit_put_watch(tmp_watch); /* match initial get */ | |
1187 | ||
1188 | return ret; | |
fe7752ba DW |
1189 | } |
1190 | ||
93315ed6 AG |
1191 | /* List rules using struct audit_rule. Exists for backward |
1192 | * compatibility with userspace. */ | |
9044e6bc | 1193 | static void audit_list(int pid, int seq, struct sk_buff_head *q) |
fe7752ba | 1194 | { |
9044e6bc | 1195 | struct sk_buff *skb; |
fe7752ba DW |
1196 | struct audit_entry *entry; |
1197 | int i; | |
1198 | ||
f368c07d AG |
1199 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
1200 | * iterator to sync with list writers. */ | |
fe7752ba | 1201 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
93315ed6 AG |
1202 | list_for_each_entry(entry, &audit_filter_list[i], list) { |
1203 | struct audit_rule *rule; | |
1204 | ||
1205 | rule = audit_krule_to_rule(&entry->rule); | |
1206 | if (unlikely(!rule)) | |
1207 | break; | |
9044e6bc | 1208 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1, |
93315ed6 | 1209 | rule, sizeof(*rule)); |
9044e6bc AV |
1210 | if (skb) |
1211 | skb_queue_tail(q, skb); | |
93315ed6 AG |
1212 | kfree(rule); |
1213 | } | |
fe7752ba | 1214 | } |
f368c07d AG |
1215 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) { |
1216 | list_for_each_entry(entry, &audit_inode_hash[i], list) { | |
1217 | struct audit_rule *rule; | |
1218 | ||
1219 | rule = audit_krule_to_rule(&entry->rule); | |
1220 | if (unlikely(!rule)) | |
1221 | break; | |
1222 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1, | |
1223 | rule, sizeof(*rule)); | |
1224 | if (skb) | |
1225 | skb_queue_tail(q, skb); | |
1226 | kfree(rule); | |
1227 | } | |
1228 | } | |
9044e6bc AV |
1229 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); |
1230 | if (skb) | |
1231 | skb_queue_tail(q, skb); | |
fe7752ba DW |
1232 | } |
1233 | ||
93315ed6 | 1234 | /* List rules using struct audit_rule_data. */ |
9044e6bc | 1235 | static void audit_list_rules(int pid, int seq, struct sk_buff_head *q) |
93315ed6 | 1236 | { |
9044e6bc | 1237 | struct sk_buff *skb; |
93315ed6 AG |
1238 | struct audit_entry *e; |
1239 | int i; | |
1240 | ||
f368c07d AG |
1241 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
1242 | * iterator to sync with list writers. */ | |
93315ed6 AG |
1243 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
1244 | list_for_each_entry(e, &audit_filter_list[i], list) { | |
1245 | struct audit_rule_data *data; | |
1246 | ||
1247 | data = audit_krule_to_data(&e->rule); | |
1248 | if (unlikely(!data)) | |
1249 | break; | |
9044e6bc | 1250 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, |
f368c07d AG |
1251 | data, sizeof(*data) + data->buflen); |
1252 | if (skb) | |
1253 | skb_queue_tail(q, skb); | |
1254 | kfree(data); | |
1255 | } | |
1256 | } | |
1257 | for (i=0; i< AUDIT_INODE_BUCKETS; i++) { | |
1258 | list_for_each_entry(e, &audit_inode_hash[i], list) { | |
1259 | struct audit_rule_data *data; | |
1260 | ||
1261 | data = audit_krule_to_data(&e->rule); | |
1262 | if (unlikely(!data)) | |
1263 | break; | |
1264 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, | |
1265 | data, sizeof(*data) + data->buflen); | |
9044e6bc AV |
1266 | if (skb) |
1267 | skb_queue_tail(q, skb); | |
93315ed6 AG |
1268 | kfree(data); |
1269 | } | |
1270 | } | |
9044e6bc AV |
1271 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
1272 | if (skb) | |
1273 | skb_queue_tail(q, skb); | |
93315ed6 AG |
1274 | } |
1275 | ||
5adc8a6a AG |
1276 | /* Log rule additions and removals */ |
1277 | static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action, | |
1278 | struct audit_krule *rule, int res) | |
1279 | { | |
1280 | struct audit_buffer *ab; | |
1281 | ||
1282 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); | |
1283 | if (!ab) | |
1284 | return; | |
1285 | audit_log_format(ab, "auid=%u", loginuid); | |
1286 | if (sid) { | |
1287 | char *ctx = NULL; | |
1288 | u32 len; | |
1289 | if (selinux_ctxid_to_string(sid, &ctx, &len)) | |
1290 | audit_log_format(ab, " ssid=%u", sid); | |
1291 | else | |
1292 | audit_log_format(ab, " subj=%s", ctx); | |
1293 | kfree(ctx); | |
1294 | } | |
1295 | audit_log_format(ab, " %s rule key=", action); | |
1296 | if (rule->filterkey) | |
1297 | audit_log_untrustedstring(ab, rule->filterkey); | |
1298 | else | |
1299 | audit_log_format(ab, "(null)"); | |
1300 | audit_log_format(ab, " list=%d res=%d", rule->listnr, res); | |
1301 | audit_log_end(ab); | |
1302 | } | |
1303 | ||
fe7752ba DW |
1304 | /** |
1305 | * audit_receive_filter - apply all rules to the specified message type | |
1306 | * @type: audit message type | |
1307 | * @pid: target pid for netlink audit messages | |
1308 | * @uid: target uid for netlink audit messages | |
1309 | * @seq: netlink audit message sequence (serial) number | |
1310 | * @data: payload data | |
93315ed6 | 1311 | * @datasz: size of payload data |
fe7752ba | 1312 | * @loginuid: loginuid of sender |
ce29b682 | 1313 | * @sid: SE Linux Security ID of sender |
fe7752ba DW |
1314 | */ |
1315 | int audit_receive_filter(int type, int pid, int uid, int seq, void *data, | |
ce29b682 | 1316 | size_t datasz, uid_t loginuid, u32 sid) |
fe7752ba DW |
1317 | { |
1318 | struct task_struct *tsk; | |
9044e6bc | 1319 | struct audit_netlink_list *dest; |
93315ed6 AG |
1320 | int err = 0; |
1321 | struct audit_entry *entry; | |
fe7752ba DW |
1322 | |
1323 | switch (type) { | |
1324 | case AUDIT_LIST: | |
93315ed6 | 1325 | case AUDIT_LIST_RULES: |
fe7752ba DW |
1326 | /* We can't just spew out the rules here because we might fill |
1327 | * the available socket buffer space and deadlock waiting for | |
1328 | * auditctl to read from it... which isn't ever going to | |
1329 | * happen if we're actually running in the context of auditctl | |
1330 | * trying to _send_ the stuff */ | |
1331 | ||
9044e6bc | 1332 | dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); |
fe7752ba DW |
1333 | if (!dest) |
1334 | return -ENOMEM; | |
9044e6bc AV |
1335 | dest->pid = pid; |
1336 | skb_queue_head_init(&dest->q); | |
fe7752ba | 1337 | |
f368c07d | 1338 | mutex_lock(&audit_filter_mutex); |
93315ed6 | 1339 | if (type == AUDIT_LIST) |
9044e6bc | 1340 | audit_list(pid, seq, &dest->q); |
93315ed6 | 1341 | else |
9044e6bc | 1342 | audit_list_rules(pid, seq, &dest->q); |
f368c07d | 1343 | mutex_unlock(&audit_filter_mutex); |
9044e6bc AV |
1344 | |
1345 | tsk = kthread_run(audit_send_list, dest, "audit_send_list"); | |
fe7752ba | 1346 | if (IS_ERR(tsk)) { |
9044e6bc | 1347 | skb_queue_purge(&dest->q); |
fe7752ba DW |
1348 | kfree(dest); |
1349 | err = PTR_ERR(tsk); | |
1350 | } | |
1351 | break; | |
1352 | case AUDIT_ADD: | |
93315ed6 AG |
1353 | case AUDIT_ADD_RULE: |
1354 | if (type == AUDIT_ADD) | |
1355 | entry = audit_rule_to_entry(data); | |
1356 | else | |
1357 | entry = audit_data_to_entry(data, datasz); | |
1358 | if (IS_ERR(entry)) | |
1359 | return PTR_ERR(entry); | |
1360 | ||
1361 | err = audit_add_rule(entry, | |
1362 | &audit_filter_list[entry->rule.listnr]); | |
5adc8a6a | 1363 | audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err); |
5d330108 SG |
1364 | |
1365 | if (err) | |
93315ed6 | 1366 | audit_free_rule(entry); |
fe7752ba DW |
1367 | break; |
1368 | case AUDIT_DEL: | |
93315ed6 AG |
1369 | case AUDIT_DEL_RULE: |
1370 | if (type == AUDIT_DEL) | |
1371 | entry = audit_rule_to_entry(data); | |
1372 | else | |
1373 | entry = audit_data_to_entry(data, datasz); | |
1374 | if (IS_ERR(entry)) | |
1375 | return PTR_ERR(entry); | |
1376 | ||
1377 | err = audit_del_rule(entry, | |
1378 | &audit_filter_list[entry->rule.listnr]); | |
5adc8a6a AG |
1379 | audit_log_rule_change(loginuid, sid, "remove", &entry->rule, |
1380 | !err); | |
5d330108 | 1381 | |
93315ed6 | 1382 | audit_free_rule(entry); |
fe7752ba DW |
1383 | break; |
1384 | default: | |
1385 | return -EINVAL; | |
1386 | } | |
1387 | ||
1388 | return err; | |
1389 | } | |
1390 | ||
1391 | int audit_comparator(const u32 left, const u32 op, const u32 right) | |
1392 | { | |
1393 | switch (op) { | |
1394 | case AUDIT_EQUAL: | |
1395 | return (left == right); | |
1396 | case AUDIT_NOT_EQUAL: | |
1397 | return (left != right); | |
1398 | case AUDIT_LESS_THAN: | |
1399 | return (left < right); | |
1400 | case AUDIT_LESS_THAN_OR_EQUAL: | |
1401 | return (left <= right); | |
1402 | case AUDIT_GREATER_THAN: | |
1403 | return (left > right); | |
1404 | case AUDIT_GREATER_THAN_OR_EQUAL: | |
1405 | return (left >= right); | |
fe7752ba | 1406 | } |
d9d9ec6e DK |
1407 | BUG(); |
1408 | return 0; | |
fe7752ba DW |
1409 | } |
1410 | ||
f368c07d AG |
1411 | /* Compare given dentry name with last component in given path, |
1412 | * return of 0 indicates a match. */ | |
9c937dcc AG |
1413 | int audit_compare_dname_path(const char *dname, const char *path, |
1414 | int *dirlen) | |
f368c07d AG |
1415 | { |
1416 | int dlen, plen; | |
1417 | const char *p; | |
1418 | ||
1419 | if (!dname || !path) | |
1420 | return 1; | |
1421 | ||
1422 | dlen = strlen(dname); | |
1423 | plen = strlen(path); | |
1424 | if (plen < dlen) | |
1425 | return 1; | |
1426 | ||
1427 | /* disregard trailing slashes */ | |
1428 | p = path + plen - 1; | |
1429 | while ((*p == '/') && (p > path)) | |
1430 | p--; | |
1431 | ||
1432 | /* find last path component */ | |
1433 | p = p - dlen + 1; | |
1434 | if (p < path) | |
1435 | return 1; | |
1436 | else if (p > path) { | |
1437 | if (*--p != '/') | |
1438 | return 1; | |
1439 | else | |
1440 | p++; | |
1441 | } | |
fe7752ba | 1442 | |
9c937dcc AG |
1443 | /* return length of path's directory component */ |
1444 | if (dirlen) | |
1445 | *dirlen = p - path; | |
f368c07d AG |
1446 | return strncmp(p, dname, dlen); |
1447 | } | |
fe7752ba DW |
1448 | |
1449 | static int audit_filter_user_rules(struct netlink_skb_parms *cb, | |
93315ed6 | 1450 | struct audit_krule *rule, |
fe7752ba DW |
1451 | enum audit_state *state) |
1452 | { | |
1453 | int i; | |
1454 | ||
1455 | for (i = 0; i < rule->field_count; i++) { | |
93315ed6 | 1456 | struct audit_field *f = &rule->fields[i]; |
fe7752ba DW |
1457 | int result = 0; |
1458 | ||
93315ed6 | 1459 | switch (f->type) { |
fe7752ba | 1460 | case AUDIT_PID: |
93315ed6 | 1461 | result = audit_comparator(cb->creds.pid, f->op, f->val); |
fe7752ba DW |
1462 | break; |
1463 | case AUDIT_UID: | |
93315ed6 | 1464 | result = audit_comparator(cb->creds.uid, f->op, f->val); |
fe7752ba DW |
1465 | break; |
1466 | case AUDIT_GID: | |
93315ed6 | 1467 | result = audit_comparator(cb->creds.gid, f->op, f->val); |
fe7752ba DW |
1468 | break; |
1469 | case AUDIT_LOGINUID: | |
93315ed6 | 1470 | result = audit_comparator(cb->loginuid, f->op, f->val); |
fe7752ba DW |
1471 | break; |
1472 | } | |
1473 | ||
1474 | if (!result) | |
1475 | return 0; | |
1476 | } | |
1477 | switch (rule->action) { | |
1478 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; | |
fe7752ba DW |
1479 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; |
1480 | } | |
1481 | return 1; | |
1482 | } | |
1483 | ||
1484 | int audit_filter_user(struct netlink_skb_parms *cb, int type) | |
1485 | { | |
1486 | struct audit_entry *e; | |
1487 | enum audit_state state; | |
1488 | int ret = 1; | |
1489 | ||
1490 | rcu_read_lock(); | |
1491 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { | |
1492 | if (audit_filter_user_rules(cb, &e->rule, &state)) { | |
1493 | if (state == AUDIT_DISABLED) | |
1494 | ret = 0; | |
1495 | break; | |
1496 | } | |
1497 | } | |
1498 | rcu_read_unlock(); | |
1499 | ||
1500 | return ret; /* Audit by default */ | |
1501 | } | |
1502 | ||
1503 | int audit_filter_type(int type) | |
1504 | { | |
1505 | struct audit_entry *e; | |
1506 | int result = 0; | |
1507 | ||
1508 | rcu_read_lock(); | |
1509 | if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE])) | |
1510 | goto unlock_and_return; | |
1511 | ||
1512 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], | |
1513 | list) { | |
fe7752ba | 1514 | int i; |
93315ed6 AG |
1515 | for (i = 0; i < e->rule.field_count; i++) { |
1516 | struct audit_field *f = &e->rule.fields[i]; | |
1517 | if (f->type == AUDIT_MSGTYPE) { | |
1518 | result = audit_comparator(type, f->op, f->val); | |
fe7752ba DW |
1519 | if (!result) |
1520 | break; | |
1521 | } | |
1522 | } | |
1523 | if (result) | |
1524 | goto unlock_and_return; | |
1525 | } | |
1526 | unlock_and_return: | |
1527 | rcu_read_unlock(); | |
1528 | return result; | |
1529 | } | |
3dc7e315 DG |
1530 | |
1531 | /* Check to see if the rule contains any selinux fields. Returns 1 if there | |
1532 | are selinux fields specified in the rule, 0 otherwise. */ | |
1533 | static inline int audit_rule_has_selinux(struct audit_krule *rule) | |
1534 | { | |
1535 | int i; | |
1536 | ||
1537 | for (i = 0; i < rule->field_count; i++) { | |
1538 | struct audit_field *f = &rule->fields[i]; | |
1539 | switch (f->type) { | |
1540 | case AUDIT_SE_USER: | |
1541 | case AUDIT_SE_ROLE: | |
1542 | case AUDIT_SE_TYPE: | |
1543 | case AUDIT_SE_SEN: | |
1544 | case AUDIT_SE_CLR: | |
1545 | return 1; | |
1546 | } | |
1547 | } | |
1548 | ||
1549 | return 0; | |
1550 | } | |
1551 | ||
1552 | /* This function will re-initialize the se_rule field of all applicable rules. | |
1553 | * It will traverse the filter lists serarching for rules that contain selinux | |
1554 | * specific filter fields. When such a rule is found, it is copied, the | |
1555 | * selinux field is re-initialized, and the old rule is replaced with the | |
1556 | * updated rule. */ | |
1557 | int selinux_audit_rule_update(void) | |
1558 | { | |
1559 | struct audit_entry *entry, *n, *nentry; | |
f368c07d | 1560 | struct audit_watch *watch; |
3dc7e315 DG |
1561 | int i, err = 0; |
1562 | ||
f368c07d AG |
1563 | /* audit_filter_mutex synchronizes the writers */ |
1564 | mutex_lock(&audit_filter_mutex); | |
3dc7e315 DG |
1565 | |
1566 | for (i = 0; i < AUDIT_NR_FILTERS; i++) { | |
1567 | list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) { | |
1568 | if (!audit_rule_has_selinux(&entry->rule)) | |
1569 | continue; | |
1570 | ||
f368c07d AG |
1571 | watch = entry->rule.watch; |
1572 | nentry = audit_dupe_rule(&entry->rule, watch); | |
3dc7e315 DG |
1573 | if (unlikely(IS_ERR(nentry))) { |
1574 | /* save the first error encountered for the | |
1575 | * return value */ | |
1576 | if (!err) | |
1577 | err = PTR_ERR(nentry); | |
1578 | audit_panic("error updating selinux filters"); | |
f368c07d AG |
1579 | if (watch) |
1580 | list_del(&entry->rule.rlist); | |
3dc7e315 DG |
1581 | list_del_rcu(&entry->list); |
1582 | } else { | |
f368c07d AG |
1583 | if (watch) { |
1584 | list_add(&nentry->rule.rlist, | |
1585 | &watch->rules); | |
1586 | list_del(&entry->rule.rlist); | |
1587 | } | |
3dc7e315 DG |
1588 | list_replace_rcu(&entry->list, &nentry->list); |
1589 | } | |
1590 | call_rcu(&entry->rcu, audit_free_rule_rcu); | |
1591 | } | |
1592 | } | |
1593 | ||
f368c07d | 1594 | mutex_unlock(&audit_filter_mutex); |
3dc7e315 DG |
1595 | |
1596 | return err; | |
1597 | } | |
f368c07d AG |
1598 | |
1599 | /* Update watch data in audit rules based on inotify events. */ | |
1600 | void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask, | |
1601 | u32 cookie, const char *dname, struct inode *inode) | |
1602 | { | |
1603 | struct audit_parent *parent; | |
1604 | ||
1605 | parent = container_of(i_watch, struct audit_parent, wdata); | |
1606 | ||
1607 | if (mask & (IN_CREATE|IN_MOVED_TO) && inode) | |
1608 | audit_update_watch(parent, dname, inode->i_sb->s_dev, | |
1609 | inode->i_ino, 0); | |
1610 | else if (mask & (IN_DELETE|IN_MOVED_FROM)) | |
1611 | audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1); | |
1612 | /* inotify automatically removes the watch and sends IN_IGNORED */ | |
1613 | else if (mask & (IN_DELETE_SELF|IN_UNMOUNT)) | |
1614 | audit_remove_parent_watches(parent); | |
1615 | /* inotify does not remove the watch, so remove it manually */ | |
1616 | else if(mask & IN_MOVE_SELF) { | |
1617 | audit_remove_parent_watches(parent); | |
1618 | inotify_remove_watch_locked(audit_ih, i_watch); | |
1619 | } else if (mask & IN_IGNORED) | |
1620 | put_inotify_watch(i_watch); | |
1621 | } |