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 | 29 | #include <linux/sched.h> |
5a0e3ad6 | 30 | #include <linux/slab.h> |
2a862b32 | 31 | #include <linux/security.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 | |
d7a96f3a | 41 | * LSM rules during filtering. If modified, these structures |
f368c07d AG |
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 | ||
f368c07d | 47 | /* Audit filter lists, defined in <linux/audit.h> */ |
fe7752ba DW |
48 | struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { |
49 | LIST_HEAD_INIT(audit_filter_list[0]), | |
50 | LIST_HEAD_INIT(audit_filter_list[1]), | |
51 | LIST_HEAD_INIT(audit_filter_list[2]), | |
52 | LIST_HEAD_INIT(audit_filter_list[3]), | |
53 | LIST_HEAD_INIT(audit_filter_list[4]), | |
54 | LIST_HEAD_INIT(audit_filter_list[5]), | |
55 | #if AUDIT_NR_FILTERS != 6 | |
56 | #error Fix audit_filter_list initialiser | |
57 | #endif | |
58 | }; | |
e45aa212 AV |
59 | static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = { |
60 | LIST_HEAD_INIT(audit_rules_list[0]), | |
61 | LIST_HEAD_INIT(audit_rules_list[1]), | |
62 | LIST_HEAD_INIT(audit_rules_list[2]), | |
63 | LIST_HEAD_INIT(audit_rules_list[3]), | |
64 | LIST_HEAD_INIT(audit_rules_list[4]), | |
65 | LIST_HEAD_INIT(audit_rules_list[5]), | |
66 | }; | |
fe7752ba | 67 | |
74c3cbe3 | 68 | DEFINE_MUTEX(audit_filter_mutex); |
f368c07d | 69 | |
93315ed6 | 70 | static inline void audit_free_rule(struct audit_entry *e) |
fe7752ba | 71 | { |
3dc7e315 | 72 | int i; |
c28bb7da | 73 | struct audit_krule *erule = &e->rule; |
ae7b8f41 | 74 | |
f368c07d | 75 | /* some rules don't have associated watches */ |
c28bb7da ZX |
76 | if (erule->watch) |
77 | audit_put_watch(erule->watch); | |
78 | if (erule->fields) | |
79 | for (i = 0; i < erule->field_count; i++) { | |
80 | struct audit_field *f = &erule->fields[i]; | |
04305e4a AD |
81 | kfree(f->lsm_str); |
82 | security_audit_rule_free(f->lsm_rule); | |
3dc7e315 | 83 | } |
c28bb7da ZX |
84 | kfree(erule->fields); |
85 | kfree(erule->filterkey); | |
93315ed6 AG |
86 | kfree(e); |
87 | } | |
88 | ||
74c3cbe3 | 89 | void audit_free_rule_rcu(struct rcu_head *head) |
93315ed6 AG |
90 | { |
91 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); | |
92 | audit_free_rule(e); | |
93 | } | |
94 | ||
3dc7e315 DG |
95 | /* Initialize an audit filterlist entry. */ |
96 | static inline struct audit_entry *audit_init_entry(u32 field_count) | |
97 | { | |
98 | struct audit_entry *entry; | |
99 | struct audit_field *fields; | |
100 | ||
101 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); | |
102 | if (unlikely(!entry)) | |
103 | return NULL; | |
104 | ||
105 | fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL); | |
106 | if (unlikely(!fields)) { | |
107 | kfree(entry); | |
108 | return NULL; | |
109 | } | |
110 | entry->rule.fields = fields; | |
111 | ||
112 | return entry; | |
113 | } | |
114 | ||
93315ed6 AG |
115 | /* Unpack a filter field's string representation from user-space |
116 | * buffer. */ | |
74c3cbe3 | 117 | char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
93315ed6 AG |
118 | { |
119 | char *str; | |
120 | ||
121 | if (!*bufp || (len == 0) || (len > *remain)) | |
122 | return ERR_PTR(-EINVAL); | |
123 | ||
124 | /* Of the currently implemented string fields, PATH_MAX | |
125 | * defines the longest valid length. | |
126 | */ | |
127 | if (len > PATH_MAX) | |
128 | return ERR_PTR(-ENAMETOOLONG); | |
129 | ||
130 | str = kmalloc(len + 1, GFP_KERNEL); | |
131 | if (unlikely(!str)) | |
132 | return ERR_PTR(-ENOMEM); | |
133 | ||
134 | memcpy(str, *bufp, len); | |
135 | str[len] = 0; | |
136 | *bufp += len; | |
137 | *remain -= len; | |
138 | ||
139 | return str; | |
140 | } | |
141 | ||
f368c07d AG |
142 | /* Translate an inode field to kernel respresentation. */ |
143 | static inline int audit_to_inode(struct audit_krule *krule, | |
144 | struct audit_field *f) | |
145 | { | |
146 | if (krule->listnr != AUDIT_FILTER_EXIT || | |
5af75d8d AV |
147 | krule->watch || krule->inode_f || krule->tree || |
148 | (f->op != Audit_equal && f->op != Audit_not_equal)) | |
f368c07d AG |
149 | return -EINVAL; |
150 | ||
151 | krule->inode_f = f; | |
152 | return 0; | |
153 | } | |
154 | ||
b915543b AV |
155 | static __u32 *classes[AUDIT_SYSCALL_CLASSES]; |
156 | ||
157 | int __init audit_register_class(int class, unsigned *list) | |
158 | { | |
159 | __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL); | |
160 | if (!p) | |
161 | return -ENOMEM; | |
162 | while (*list != ~0U) { | |
163 | unsigned n = *list++; | |
164 | if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) { | |
165 | kfree(p); | |
166 | return -EINVAL; | |
167 | } | |
168 | p[AUDIT_WORD(n)] |= AUDIT_BIT(n); | |
169 | } | |
170 | if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) { | |
171 | kfree(p); | |
172 | return -EINVAL; | |
173 | } | |
174 | classes[class] = p; | |
175 | return 0; | |
176 | } | |
177 | ||
55669bfa AV |
178 | int audit_match_class(int class, unsigned syscall) |
179 | { | |
c926e4f4 | 180 | if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32)) |
55669bfa AV |
181 | return 0; |
182 | if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class])) | |
183 | return 0; | |
184 | return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall); | |
185 | } | |
186 | ||
327b9eeb | 187 | #ifdef CONFIG_AUDITSYSCALL |
e54dc243 AG |
188 | static inline int audit_match_class_bits(int class, u32 *mask) |
189 | { | |
190 | int i; | |
191 | ||
192 | if (classes[class]) { | |
193 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
194 | if (mask[i] & classes[class][i]) | |
195 | return 0; | |
196 | } | |
197 | return 1; | |
198 | } | |
199 | ||
200 | static int audit_match_signal(struct audit_entry *entry) | |
201 | { | |
202 | struct audit_field *arch = entry->rule.arch_f; | |
203 | ||
204 | if (!arch) { | |
205 | /* When arch is unspecified, we must check both masks on biarch | |
206 | * as syscall number alone is ambiguous. */ | |
207 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, | |
208 | entry->rule.mask) && | |
209 | audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, | |
210 | entry->rule.mask)); | |
211 | } | |
212 | ||
213 | switch(audit_classify_arch(arch->val)) { | |
214 | case 0: /* native */ | |
215 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, | |
216 | entry->rule.mask)); | |
217 | case 1: /* 32bit on biarch */ | |
218 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, | |
219 | entry->rule.mask)); | |
220 | default: | |
221 | return 1; | |
222 | } | |
223 | } | |
327b9eeb | 224 | #endif |
e54dc243 | 225 | |
93315ed6 AG |
226 | /* Common user-space to kernel rule translation. */ |
227 | static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) | |
228 | { | |
229 | unsigned listnr; | |
230 | struct audit_entry *entry; | |
93315ed6 AG |
231 | int i, err; |
232 | ||
233 | err = -EINVAL; | |
234 | listnr = rule->flags & ~AUDIT_FILTER_PREPEND; | |
235 | switch(listnr) { | |
236 | default: | |
237 | goto exit_err; | |
93315ed6 AG |
238 | #ifdef CONFIG_AUDITSYSCALL |
239 | case AUDIT_FILTER_ENTRY: | |
7ff68e53 EP |
240 | if (rule->action == AUDIT_ALWAYS) |
241 | goto exit_err; | |
93315ed6 AG |
242 | case AUDIT_FILTER_EXIT: |
243 | case AUDIT_FILTER_TASK: | |
244 | #endif | |
7ff68e53 EP |
245 | case AUDIT_FILTER_USER: |
246 | case AUDIT_FILTER_TYPE: | |
93315ed6 AG |
247 | ; |
248 | } | |
014149cc AV |
249 | if (unlikely(rule->action == AUDIT_POSSIBLE)) { |
250 | printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n"); | |
251 | goto exit_err; | |
252 | } | |
253 | if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS) | |
93315ed6 AG |
254 | goto exit_err; |
255 | if (rule->field_count > AUDIT_MAX_FIELDS) | |
256 | goto exit_err; | |
257 | ||
258 | err = -ENOMEM; | |
3dc7e315 DG |
259 | entry = audit_init_entry(rule->field_count); |
260 | if (!entry) | |
93315ed6 | 261 | goto exit_err; |
93315ed6 AG |
262 | |
263 | entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; | |
264 | entry->rule.listnr = listnr; | |
265 | entry->rule.action = rule->action; | |
266 | entry->rule.field_count = rule->field_count; | |
93315ed6 AG |
267 | |
268 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
269 | entry->rule.mask[i] = rule->mask[i]; | |
270 | ||
b915543b AV |
271 | for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) { |
272 | int bit = AUDIT_BITMASK_SIZE * 32 - i - 1; | |
273 | __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)]; | |
274 | __u32 *class; | |
275 | ||
276 | if (!(*p & AUDIT_BIT(bit))) | |
277 | continue; | |
278 | *p &= ~AUDIT_BIT(bit); | |
279 | class = classes[i]; | |
280 | if (class) { | |
281 | int j; | |
282 | for (j = 0; j < AUDIT_BITMASK_SIZE; j++) | |
283 | entry->rule.mask[j] |= class[j]; | |
284 | } | |
285 | } | |
286 | ||
93315ed6 AG |
287 | return entry; |
288 | ||
289 | exit_err: | |
290 | return ERR_PTR(err); | |
291 | } | |
292 | ||
5af75d8d AV |
293 | static u32 audit_ops[] = |
294 | { | |
295 | [Audit_equal] = AUDIT_EQUAL, | |
296 | [Audit_not_equal] = AUDIT_NOT_EQUAL, | |
297 | [Audit_bitmask] = AUDIT_BIT_MASK, | |
298 | [Audit_bittest] = AUDIT_BIT_TEST, | |
299 | [Audit_lt] = AUDIT_LESS_THAN, | |
300 | [Audit_gt] = AUDIT_GREATER_THAN, | |
301 | [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL, | |
302 | [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL, | |
303 | }; | |
304 | ||
305 | static u32 audit_to_op(u32 op) | |
306 | { | |
307 | u32 n; | |
308 | for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++) | |
309 | ; | |
310 | return n; | |
311 | } | |
312 | ||
ab61d38e | 313 | /* check if an audit field is valid */ |
62062cf8 EP |
314 | static int audit_field_valid(struct audit_entry *entry, struct audit_field *f) |
315 | { | |
316 | switch(f->type) { | |
317 | case AUDIT_MSGTYPE: | |
318 | if (entry->rule.listnr != AUDIT_FILTER_TYPE && | |
319 | entry->rule.listnr != AUDIT_FILTER_USER) | |
320 | return -EINVAL; | |
321 | break; | |
322 | }; | |
ab61d38e EP |
323 | |
324 | switch(f->type) { | |
325 | default: | |
326 | return -EINVAL; | |
327 | case AUDIT_UID: | |
328 | case AUDIT_EUID: | |
329 | case AUDIT_SUID: | |
330 | case AUDIT_FSUID: | |
331 | case AUDIT_LOGINUID: | |
332 | case AUDIT_OBJ_UID: | |
333 | case AUDIT_GID: | |
334 | case AUDIT_EGID: | |
335 | case AUDIT_SGID: | |
336 | case AUDIT_FSGID: | |
337 | case AUDIT_OBJ_GID: | |
338 | case AUDIT_PID: | |
339 | case AUDIT_PERS: | |
340 | case AUDIT_MSGTYPE: | |
341 | case AUDIT_PPID: | |
342 | case AUDIT_DEVMAJOR: | |
343 | case AUDIT_DEVMINOR: | |
344 | case AUDIT_EXIT: | |
345 | case AUDIT_SUCCESS: | |
346 | /* bit ops are only useful on syscall args */ | |
347 | if (f->op == Audit_bitmask || f->op == Audit_bittest) | |
348 | return -EINVAL; | |
349 | break; | |
350 | case AUDIT_ARG0: | |
351 | case AUDIT_ARG1: | |
352 | case AUDIT_ARG2: | |
353 | case AUDIT_ARG3: | |
354 | case AUDIT_SUBJ_USER: | |
355 | case AUDIT_SUBJ_ROLE: | |
356 | case AUDIT_SUBJ_TYPE: | |
357 | case AUDIT_SUBJ_SEN: | |
358 | case AUDIT_SUBJ_CLR: | |
359 | case AUDIT_OBJ_USER: | |
360 | case AUDIT_OBJ_ROLE: | |
361 | case AUDIT_OBJ_TYPE: | |
362 | case AUDIT_OBJ_LEV_LOW: | |
363 | case AUDIT_OBJ_LEV_HIGH: | |
364 | case AUDIT_WATCH: | |
365 | case AUDIT_DIR: | |
366 | case AUDIT_FILTERKEY: | |
367 | break; | |
368 | /* arch is only allowed to be = or != */ | |
369 | case AUDIT_ARCH: | |
370 | if (f->op != Audit_not_equal && f->op != Audit_equal) | |
371 | return -EINVAL; | |
372 | break; | |
373 | case AUDIT_PERM: | |
374 | if (f->val & ~15) | |
375 | return -EINVAL; | |
376 | break; | |
377 | case AUDIT_FILETYPE: | |
378 | if (f->val & ~S_IFMT) | |
379 | return -EINVAL; | |
380 | break; | |
381 | case AUDIT_FIELD_COMPARE: | |
382 | if (f->val > AUDIT_MAX_FIELD_COMPARE) | |
383 | return -EINVAL; | |
384 | break; | |
385 | }; | |
62062cf8 EP |
386 | return 0; |
387 | } | |
5af75d8d | 388 | |
93315ed6 AG |
389 | /* Translate struct audit_rule_data to kernel's rule respresentation. */ |
390 | static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, | |
391 | size_t datasz) | |
fe7752ba | 392 | { |
93315ed6 AG |
393 | int err = 0; |
394 | struct audit_entry *entry; | |
395 | void *bufp; | |
3dc7e315 | 396 | size_t remain = datasz - sizeof(struct audit_rule_data); |
fe7752ba | 397 | int i; |
3dc7e315 | 398 | char *str; |
fe7752ba | 399 | |
93315ed6 AG |
400 | entry = audit_to_entry_common((struct audit_rule *)data); |
401 | if (IS_ERR(entry)) | |
402 | goto exit_nofree; | |
fe7752ba | 403 | |
93315ed6 AG |
404 | bufp = data->buf; |
405 | entry->rule.vers_ops = 2; | |
406 | for (i = 0; i < data->field_count; i++) { | |
407 | struct audit_field *f = &entry->rule.fields[i]; | |
408 | ||
409 | err = -EINVAL; | |
5af75d8d AV |
410 | |
411 | f->op = audit_to_op(data->fieldflags[i]); | |
412 | if (f->op == Audit_bad) | |
93315ed6 AG |
413 | goto exit_free; |
414 | ||
93315ed6 | 415 | f->type = data->fields[i]; |
3dc7e315 | 416 | f->val = data->values[i]; |
ca57ec0f EB |
417 | f->uid = INVALID_UID; |
418 | f->gid = INVALID_GID; | |
04305e4a AD |
419 | f->lsm_str = NULL; |
420 | f->lsm_rule = NULL; | |
62062cf8 EP |
421 | |
422 | err = audit_field_valid(entry, f); | |
423 | if (err) | |
424 | goto exit_free; | |
425 | ||
426 | err = -EINVAL; | |
ab61d38e | 427 | switch (f->type) { |
0a73dccc AV |
428 | case AUDIT_UID: |
429 | case AUDIT_EUID: | |
430 | case AUDIT_SUID: | |
431 | case AUDIT_FSUID: | |
ca57ec0f EB |
432 | case AUDIT_LOGINUID: |
433 | case AUDIT_OBJ_UID: | |
ca57ec0f EB |
434 | f->uid = make_kuid(current_user_ns(), f->val); |
435 | if (!uid_valid(f->uid)) | |
436 | goto exit_free; | |
437 | break; | |
0a73dccc AV |
438 | case AUDIT_GID: |
439 | case AUDIT_EGID: | |
440 | case AUDIT_SGID: | |
441 | case AUDIT_FSGID: | |
ca57ec0f | 442 | case AUDIT_OBJ_GID: |
ca57ec0f EB |
443 | f->gid = make_kgid(current_user_ns(), f->val); |
444 | if (!gid_valid(f->gid)) | |
445 | goto exit_free; | |
446 | break; | |
e54dc243 AG |
447 | case AUDIT_ARCH: |
448 | entry->rule.arch_f = f; | |
449 | break; | |
3a6b9f85 DG |
450 | case AUDIT_SUBJ_USER: |
451 | case AUDIT_SUBJ_ROLE: | |
452 | case AUDIT_SUBJ_TYPE: | |
453 | case AUDIT_SUBJ_SEN: | |
454 | case AUDIT_SUBJ_CLR: | |
6e5a2d1d DG |
455 | case AUDIT_OBJ_USER: |
456 | case AUDIT_OBJ_ROLE: | |
457 | case AUDIT_OBJ_TYPE: | |
458 | case AUDIT_OBJ_LEV_LOW: | |
459 | case AUDIT_OBJ_LEV_HIGH: | |
3dc7e315 DG |
460 | str = audit_unpack_string(&bufp, &remain, f->val); |
461 | if (IS_ERR(str)) | |
462 | goto exit_free; | |
463 | entry->rule.buflen += f->val; | |
464 | ||
d7a96f3a | 465 | err = security_audit_rule_init(f->type, f->op, str, |
04305e4a | 466 | (void **)&f->lsm_rule); |
3dc7e315 DG |
467 | /* Keep currently invalid fields around in case they |
468 | * become valid after a policy reload. */ | |
469 | if (err == -EINVAL) { | |
d7a96f3a | 470 | printk(KERN_WARNING "audit rule for LSM " |
3dc7e315 DG |
471 | "\'%s\' is invalid\n", str); |
472 | err = 0; | |
473 | } | |
474 | if (err) { | |
475 | kfree(str); | |
476 | goto exit_free; | |
477 | } else | |
04305e4a | 478 | f->lsm_str = str; |
3dc7e315 | 479 | break; |
f368c07d AG |
480 | case AUDIT_WATCH: |
481 | str = audit_unpack_string(&bufp, &remain, f->val); | |
482 | if (IS_ERR(str)) | |
483 | goto exit_free; | |
484 | entry->rule.buflen += f->val; | |
485 | ||
486 | err = audit_to_watch(&entry->rule, str, f->val, f->op); | |
487 | if (err) { | |
488 | kfree(str); | |
489 | goto exit_free; | |
490 | } | |
491 | break; | |
74c3cbe3 AV |
492 | case AUDIT_DIR: |
493 | str = audit_unpack_string(&bufp, &remain, f->val); | |
494 | if (IS_ERR(str)) | |
495 | goto exit_free; | |
496 | entry->rule.buflen += f->val; | |
497 | ||
498 | err = audit_make_tree(&entry->rule, str, f->op); | |
499 | kfree(str); | |
500 | if (err) | |
501 | goto exit_free; | |
502 | break; | |
f368c07d AG |
503 | case AUDIT_INODE: |
504 | err = audit_to_inode(&entry->rule, f); | |
505 | if (err) | |
506 | goto exit_free; | |
507 | break; | |
5adc8a6a | 508 | case AUDIT_FILTERKEY: |
5adc8a6a AG |
509 | if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN) |
510 | goto exit_free; | |
511 | str = audit_unpack_string(&bufp, &remain, f->val); | |
512 | if (IS_ERR(str)) | |
513 | goto exit_free; | |
514 | entry->rule.buflen += f->val; | |
515 | entry->rule.filterkey = str; | |
516 | break; | |
f368c07d AG |
517 | } |
518 | } | |
519 | ||
5af75d8d AV |
520 | if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) |
521 | entry->rule.inode_f = NULL; | |
93315ed6 AG |
522 | |
523 | exit_nofree: | |
524 | return entry; | |
525 | ||
526 | exit_free: | |
527 | audit_free_rule(entry); | |
528 | return ERR_PTR(err); | |
529 | } | |
530 | ||
531 | /* Pack a filter field's string representation into data block. */ | |
74c3cbe3 | 532 | static inline size_t audit_pack_string(void **bufp, const char *str) |
93315ed6 AG |
533 | { |
534 | size_t len = strlen(str); | |
535 | ||
536 | memcpy(*bufp, str, len); | |
537 | *bufp += len; | |
538 | ||
539 | return len; | |
540 | } | |
541 | ||
93315ed6 AG |
542 | /* Translate kernel rule respresentation to struct audit_rule_data. */ |
543 | static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) | |
544 | { | |
545 | struct audit_rule_data *data; | |
546 | void *bufp; | |
547 | int i; | |
548 | ||
549 | data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); | |
550 | if (unlikely(!data)) | |
0a3b483e | 551 | return NULL; |
93315ed6 AG |
552 | memset(data, 0, sizeof(*data)); |
553 | ||
554 | data->flags = krule->flags | krule->listnr; | |
555 | data->action = krule->action; | |
556 | data->field_count = krule->field_count; | |
557 | bufp = data->buf; | |
558 | for (i = 0; i < data->field_count; i++) { | |
559 | struct audit_field *f = &krule->fields[i]; | |
560 | ||
561 | data->fields[i] = f->type; | |
5af75d8d | 562 | data->fieldflags[i] = audit_ops[f->op]; |
93315ed6 | 563 | switch(f->type) { |
3a6b9f85 DG |
564 | case AUDIT_SUBJ_USER: |
565 | case AUDIT_SUBJ_ROLE: | |
566 | case AUDIT_SUBJ_TYPE: | |
567 | case AUDIT_SUBJ_SEN: | |
568 | case AUDIT_SUBJ_CLR: | |
6e5a2d1d DG |
569 | case AUDIT_OBJ_USER: |
570 | case AUDIT_OBJ_ROLE: | |
571 | case AUDIT_OBJ_TYPE: | |
572 | case AUDIT_OBJ_LEV_LOW: | |
573 | case AUDIT_OBJ_LEV_HIGH: | |
3dc7e315 | 574 | data->buflen += data->values[i] = |
04305e4a | 575 | audit_pack_string(&bufp, f->lsm_str); |
3dc7e315 | 576 | break; |
f368c07d AG |
577 | case AUDIT_WATCH: |
578 | data->buflen += data->values[i] = | |
cfcad62c EP |
579 | audit_pack_string(&bufp, |
580 | audit_watch_path(krule->watch)); | |
f368c07d | 581 | break; |
74c3cbe3 AV |
582 | case AUDIT_DIR: |
583 | data->buflen += data->values[i] = | |
584 | audit_pack_string(&bufp, | |
585 | audit_tree_path(krule->tree)); | |
586 | break; | |
5adc8a6a AG |
587 | case AUDIT_FILTERKEY: |
588 | data->buflen += data->values[i] = | |
589 | audit_pack_string(&bufp, krule->filterkey); | |
590 | break; | |
93315ed6 AG |
591 | default: |
592 | data->values[i] = f->val; | |
593 | } | |
594 | } | |
595 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; | |
596 | ||
597 | return data; | |
598 | } | |
599 | ||
600 | /* Compare two rules in kernel format. Considered success if rules | |
601 | * don't match. */ | |
602 | static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) | |
603 | { | |
604 | int i; | |
605 | ||
606 | if (a->flags != b->flags || | |
607 | a->listnr != b->listnr || | |
608 | a->action != b->action || | |
609 | a->field_count != b->field_count) | |
fe7752ba DW |
610 | return 1; |
611 | ||
612 | for (i = 0; i < a->field_count; i++) { | |
93315ed6 AG |
613 | if (a->fields[i].type != b->fields[i].type || |
614 | a->fields[i].op != b->fields[i].op) | |
fe7752ba | 615 | return 1; |
93315ed6 AG |
616 | |
617 | switch(a->fields[i].type) { | |
3a6b9f85 DG |
618 | case AUDIT_SUBJ_USER: |
619 | case AUDIT_SUBJ_ROLE: | |
620 | case AUDIT_SUBJ_TYPE: | |
621 | case AUDIT_SUBJ_SEN: | |
622 | case AUDIT_SUBJ_CLR: | |
6e5a2d1d DG |
623 | case AUDIT_OBJ_USER: |
624 | case AUDIT_OBJ_ROLE: | |
625 | case AUDIT_OBJ_TYPE: | |
626 | case AUDIT_OBJ_LEV_LOW: | |
627 | case AUDIT_OBJ_LEV_HIGH: | |
04305e4a | 628 | if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str)) |
3dc7e315 DG |
629 | return 1; |
630 | break; | |
f368c07d | 631 | case AUDIT_WATCH: |
cfcad62c EP |
632 | if (strcmp(audit_watch_path(a->watch), |
633 | audit_watch_path(b->watch))) | |
f368c07d AG |
634 | return 1; |
635 | break; | |
74c3cbe3 AV |
636 | case AUDIT_DIR: |
637 | if (strcmp(audit_tree_path(a->tree), | |
638 | audit_tree_path(b->tree))) | |
639 | return 1; | |
640 | break; | |
5adc8a6a AG |
641 | case AUDIT_FILTERKEY: |
642 | /* both filterkeys exist based on above type compare */ | |
643 | if (strcmp(a->filterkey, b->filterkey)) | |
644 | return 1; | |
645 | break; | |
ca57ec0f EB |
646 | case AUDIT_UID: |
647 | case AUDIT_EUID: | |
648 | case AUDIT_SUID: | |
649 | case AUDIT_FSUID: | |
650 | case AUDIT_LOGINUID: | |
651 | case AUDIT_OBJ_UID: | |
652 | if (!uid_eq(a->fields[i].uid, b->fields[i].uid)) | |
653 | return 1; | |
654 | break; | |
655 | case AUDIT_GID: | |
656 | case AUDIT_EGID: | |
657 | case AUDIT_SGID: | |
658 | case AUDIT_FSGID: | |
659 | case AUDIT_OBJ_GID: | |
660 | if (!gid_eq(a->fields[i].gid, b->fields[i].gid)) | |
661 | return 1; | |
662 | break; | |
93315ed6 AG |
663 | default: |
664 | if (a->fields[i].val != b->fields[i].val) | |
665 | return 1; | |
666 | } | |
fe7752ba DW |
667 | } |
668 | ||
669 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
670 | if (a->mask[i] != b->mask[i]) | |
671 | return 1; | |
672 | ||
673 | return 0; | |
674 | } | |
675 | ||
04305e4a | 676 | /* Duplicate LSM field information. The lsm_rule is opaque, so must be |
3dc7e315 | 677 | * re-initialized. */ |
d7a96f3a | 678 | static inline int audit_dupe_lsm_field(struct audit_field *df, |
3dc7e315 DG |
679 | struct audit_field *sf) |
680 | { | |
681 | int ret = 0; | |
04305e4a | 682 | char *lsm_str; |
3dc7e315 | 683 | |
04305e4a AD |
684 | /* our own copy of lsm_str */ |
685 | lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL); | |
686 | if (unlikely(!lsm_str)) | |
3e1fbd12 | 687 | return -ENOMEM; |
04305e4a | 688 | df->lsm_str = lsm_str; |
3dc7e315 | 689 | |
04305e4a AD |
690 | /* our own (refreshed) copy of lsm_rule */ |
691 | ret = security_audit_rule_init(df->type, df->op, df->lsm_str, | |
692 | (void **)&df->lsm_rule); | |
3dc7e315 DG |
693 | /* Keep currently invalid fields around in case they |
694 | * become valid after a policy reload. */ | |
695 | if (ret == -EINVAL) { | |
d7a96f3a | 696 | printk(KERN_WARNING "audit rule for LSM \'%s\' is " |
04305e4a | 697 | "invalid\n", df->lsm_str); |
3dc7e315 DG |
698 | ret = 0; |
699 | } | |
700 | ||
701 | return ret; | |
702 | } | |
703 | ||
704 | /* Duplicate an audit rule. This will be a deep copy with the exception | |
d7a96f3a | 705 | * of the watch - that pointer is carried over. The LSM specific fields |
3dc7e315 | 706 | * will be updated in the copy. The point is to be able to replace the old |
f368c07d AG |
707 | * rule with the new rule in the filterlist, then free the old rule. |
708 | * The rlist element is undefined; list manipulations are handled apart from | |
709 | * the initial copy. */ | |
ae7b8f41 | 710 | struct audit_entry *audit_dupe_rule(struct audit_krule *old) |
3dc7e315 DG |
711 | { |
712 | u32 fcount = old->field_count; | |
713 | struct audit_entry *entry; | |
714 | struct audit_krule *new; | |
5adc8a6a | 715 | char *fk; |
3dc7e315 DG |
716 | int i, err = 0; |
717 | ||
718 | entry = audit_init_entry(fcount); | |
719 | if (unlikely(!entry)) | |
720 | return ERR_PTR(-ENOMEM); | |
721 | ||
722 | new = &entry->rule; | |
723 | new->vers_ops = old->vers_ops; | |
724 | new->flags = old->flags; | |
725 | new->listnr = old->listnr; | |
726 | new->action = old->action; | |
727 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
728 | new->mask[i] = old->mask[i]; | |
0590b933 | 729 | new->prio = old->prio; |
3dc7e315 | 730 | new->buflen = old->buflen; |
f368c07d | 731 | new->inode_f = old->inode_f; |
3dc7e315 | 732 | new->field_count = old->field_count; |
ae7b8f41 | 733 | |
74c3cbe3 AV |
734 | /* |
735 | * note that we are OK with not refcounting here; audit_match_tree() | |
736 | * never dereferences tree and we can't get false positives there | |
737 | * since we'd have to have rule gone from the list *and* removed | |
738 | * before the chunks found by lookup had been allocated, i.e. before | |
739 | * the beginning of list scan. | |
740 | */ | |
741 | new->tree = old->tree; | |
3dc7e315 DG |
742 | memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); |
743 | ||
04305e4a | 744 | /* deep copy this information, updating the lsm_rule fields, because |
3dc7e315 DG |
745 | * the originals will all be freed when the old rule is freed. */ |
746 | for (i = 0; i < fcount; i++) { | |
747 | switch (new->fields[i].type) { | |
3a6b9f85 DG |
748 | case AUDIT_SUBJ_USER: |
749 | case AUDIT_SUBJ_ROLE: | |
750 | case AUDIT_SUBJ_TYPE: | |
751 | case AUDIT_SUBJ_SEN: | |
752 | case AUDIT_SUBJ_CLR: | |
6e5a2d1d DG |
753 | case AUDIT_OBJ_USER: |
754 | case AUDIT_OBJ_ROLE: | |
755 | case AUDIT_OBJ_TYPE: | |
756 | case AUDIT_OBJ_LEV_LOW: | |
757 | case AUDIT_OBJ_LEV_HIGH: | |
d7a96f3a | 758 | err = audit_dupe_lsm_field(&new->fields[i], |
3dc7e315 | 759 | &old->fields[i]); |
5adc8a6a AG |
760 | break; |
761 | case AUDIT_FILTERKEY: | |
762 | fk = kstrdup(old->filterkey, GFP_KERNEL); | |
763 | if (unlikely(!fk)) | |
764 | err = -ENOMEM; | |
765 | else | |
766 | new->filterkey = fk; | |
3dc7e315 DG |
767 | } |
768 | if (err) { | |
769 | audit_free_rule(entry); | |
770 | return ERR_PTR(err); | |
771 | } | |
772 | } | |
773 | ||
ae7b8f41 EP |
774 | if (old->watch) { |
775 | audit_get_watch(old->watch); | |
776 | new->watch = old->watch; | |
f368c07d AG |
777 | } |
778 | ||
3dc7e315 DG |
779 | return entry; |
780 | } | |
781 | ||
f368c07d AG |
782 | /* Find an existing audit rule. |
783 | * Caller must hold audit_filter_mutex to prevent stale rule data. */ | |
784 | static struct audit_entry *audit_find_rule(struct audit_entry *entry, | |
36c4f1b1 | 785 | struct list_head **p) |
f368c07d AG |
786 | { |
787 | struct audit_entry *e, *found = NULL; | |
36c4f1b1 | 788 | struct list_head *list; |
f368c07d AG |
789 | int h; |
790 | ||
36c4f1b1 AV |
791 | if (entry->rule.inode_f) { |
792 | h = audit_hash_ino(entry->rule.inode_f->val); | |
793 | *p = list = &audit_inode_hash[h]; | |
794 | } else if (entry->rule.watch) { | |
f368c07d AG |
795 | /* we don't know the inode number, so must walk entire hash */ |
796 | for (h = 0; h < AUDIT_INODE_BUCKETS; h++) { | |
797 | list = &audit_inode_hash[h]; | |
798 | list_for_each_entry(e, list, list) | |
799 | if (!audit_compare_rule(&entry->rule, &e->rule)) { | |
800 | found = e; | |
801 | goto out; | |
802 | } | |
803 | } | |
804 | goto out; | |
36c4f1b1 AV |
805 | } else { |
806 | *p = list = &audit_filter_list[entry->rule.listnr]; | |
f368c07d AG |
807 | } |
808 | ||
809 | list_for_each_entry(e, list, list) | |
810 | if (!audit_compare_rule(&entry->rule, &e->rule)) { | |
811 | found = e; | |
812 | goto out; | |
813 | } | |
814 | ||
815 | out: | |
816 | return found; | |
817 | } | |
818 | ||
0590b933 AV |
819 | static u64 prio_low = ~0ULL/2; |
820 | static u64 prio_high = ~0ULL/2 - 1; | |
821 | ||
f368c07d | 822 | /* Add rule to given filterlist if not a duplicate. */ |
36c4f1b1 | 823 | static inline int audit_add_rule(struct audit_entry *entry) |
fe7752ba | 824 | { |
93315ed6 | 825 | struct audit_entry *e; |
f368c07d | 826 | struct audit_watch *watch = entry->rule.watch; |
74c3cbe3 | 827 | struct audit_tree *tree = entry->rule.tree; |
36c4f1b1 | 828 | struct list_head *list; |
ae7b8f41 | 829 | int err; |
471a5c7c AV |
830 | #ifdef CONFIG_AUDITSYSCALL |
831 | int dont_count = 0; | |
832 | ||
833 | /* If either of these, don't count towards total */ | |
834 | if (entry->rule.listnr == AUDIT_FILTER_USER || | |
835 | entry->rule.listnr == AUDIT_FILTER_TYPE) | |
836 | dont_count = 1; | |
837 | #endif | |
f368c07d | 838 | |
f368c07d | 839 | mutex_lock(&audit_filter_mutex); |
36c4f1b1 | 840 | e = audit_find_rule(entry, &list); |
f368c07d | 841 | if (e) { |
35fe4d0b | 842 | mutex_unlock(&audit_filter_mutex); |
f368c07d | 843 | err = -EEXIST; |
74c3cbe3 AV |
844 | /* normally audit_add_tree_rule() will free it on failure */ |
845 | if (tree) | |
846 | audit_put_tree(tree); | |
f368c07d AG |
847 | goto error; |
848 | } | |
fe7752ba | 849 | |
f368c07d AG |
850 | if (watch) { |
851 | /* audit_filter_mutex is dropped and re-taken during this call */ | |
ae7b8f41 | 852 | err = audit_add_watch(&entry->rule, &list); |
f368c07d AG |
853 | if (err) { |
854 | mutex_unlock(&audit_filter_mutex); | |
855 | goto error; | |
856 | } | |
fe7752ba | 857 | } |
74c3cbe3 AV |
858 | if (tree) { |
859 | err = audit_add_tree_rule(&entry->rule); | |
860 | if (err) { | |
861 | mutex_unlock(&audit_filter_mutex); | |
862 | goto error; | |
863 | } | |
864 | } | |
fe7752ba | 865 | |
0590b933 AV |
866 | entry->rule.prio = ~0ULL; |
867 | if (entry->rule.listnr == AUDIT_FILTER_EXIT) { | |
868 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) | |
869 | entry->rule.prio = ++prio_high; | |
870 | else | |
871 | entry->rule.prio = --prio_low; | |
872 | } | |
873 | ||
fe7752ba | 874 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
e45aa212 AV |
875 | list_add(&entry->rule.list, |
876 | &audit_rules_list[entry->rule.listnr]); | |
fe7752ba | 877 | list_add_rcu(&entry->list, list); |
6a2bceec | 878 | entry->rule.flags &= ~AUDIT_FILTER_PREPEND; |
fe7752ba | 879 | } else { |
e45aa212 AV |
880 | list_add_tail(&entry->rule.list, |
881 | &audit_rules_list[entry->rule.listnr]); | |
fe7752ba DW |
882 | list_add_tail_rcu(&entry->list, list); |
883 | } | |
471a5c7c AV |
884 | #ifdef CONFIG_AUDITSYSCALL |
885 | if (!dont_count) | |
886 | audit_n_rules++; | |
e54dc243 AG |
887 | |
888 | if (!audit_match_signal(entry)) | |
889 | audit_signals++; | |
471a5c7c | 890 | #endif |
f368c07d | 891 | mutex_unlock(&audit_filter_mutex); |
fe7752ba | 892 | |
f368c07d AG |
893 | return 0; |
894 | ||
895 | error: | |
f368c07d AG |
896 | if (watch) |
897 | audit_put_watch(watch); /* tmp watch, matches initial get */ | |
898 | return err; | |
fe7752ba DW |
899 | } |
900 | ||
f368c07d | 901 | /* Remove an existing rule from filterlist. */ |
36c4f1b1 | 902 | static inline int audit_del_rule(struct audit_entry *entry) |
fe7752ba DW |
903 | { |
904 | struct audit_entry *e; | |
cfcad62c | 905 | struct audit_watch *watch = entry->rule.watch; |
74c3cbe3 | 906 | struct audit_tree *tree = entry->rule.tree; |
36c4f1b1 | 907 | struct list_head *list; |
36c4f1b1 | 908 | int ret = 0; |
471a5c7c AV |
909 | #ifdef CONFIG_AUDITSYSCALL |
910 | int dont_count = 0; | |
911 | ||
912 | /* If either of these, don't count towards total */ | |
913 | if (entry->rule.listnr == AUDIT_FILTER_USER || | |
914 | entry->rule.listnr == AUDIT_FILTER_TYPE) | |
915 | dont_count = 1; | |
916 | #endif | |
f368c07d | 917 | |
f368c07d | 918 | mutex_lock(&audit_filter_mutex); |
36c4f1b1 | 919 | e = audit_find_rule(entry, &list); |
f368c07d AG |
920 | if (!e) { |
921 | mutex_unlock(&audit_filter_mutex); | |
922 | ret = -ENOENT; | |
923 | goto out; | |
924 | } | |
925 | ||
cfcad62c | 926 | if (e->rule.watch) |
a05fb6cc | 927 | audit_remove_watch_rule(&e->rule); |
f368c07d | 928 | |
74c3cbe3 AV |
929 | if (e->rule.tree) |
930 | audit_remove_tree_rule(&e->rule); | |
931 | ||
f368c07d | 932 | list_del_rcu(&e->list); |
e45aa212 | 933 | list_del(&e->rule.list); |
f368c07d AG |
934 | call_rcu(&e->rcu, audit_free_rule_rcu); |
935 | ||
471a5c7c AV |
936 | #ifdef CONFIG_AUDITSYSCALL |
937 | if (!dont_count) | |
938 | audit_n_rules--; | |
e54dc243 AG |
939 | |
940 | if (!audit_match_signal(entry)) | |
941 | audit_signals--; | |
471a5c7c | 942 | #endif |
f368c07d AG |
943 | mutex_unlock(&audit_filter_mutex); |
944 | ||
f368c07d | 945 | out: |
cfcad62c EP |
946 | if (watch) |
947 | audit_put_watch(watch); /* match initial get */ | |
74c3cbe3 AV |
948 | if (tree) |
949 | audit_put_tree(tree); /* that's the temporary one */ | |
f368c07d AG |
950 | |
951 | return ret; | |
fe7752ba DW |
952 | } |
953 | ||
93315ed6 | 954 | /* List rules using struct audit_rule_data. */ |
9044e6bc | 955 | static void audit_list_rules(int pid, int seq, struct sk_buff_head *q) |
93315ed6 | 956 | { |
9044e6bc | 957 | struct sk_buff *skb; |
e45aa212 | 958 | struct audit_krule *r; |
93315ed6 AG |
959 | int i; |
960 | ||
f368c07d AG |
961 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
962 | * iterator to sync with list writers. */ | |
93315ed6 | 963 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
e45aa212 | 964 | list_for_each_entry(r, &audit_rules_list[i], list) { |
f368c07d AG |
965 | struct audit_rule_data *data; |
966 | ||
e45aa212 | 967 | data = audit_krule_to_data(r); |
f368c07d AG |
968 | if (unlikely(!data)) |
969 | break; | |
970 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, | |
971 | data, sizeof(*data) + data->buflen); | |
9044e6bc AV |
972 | if (skb) |
973 | skb_queue_tail(q, skb); | |
93315ed6 AG |
974 | kfree(data); |
975 | } | |
976 | } | |
9044e6bc AV |
977 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
978 | if (skb) | |
979 | skb_queue_tail(q, skb); | |
93315ed6 AG |
980 | } |
981 | ||
5adc8a6a | 982 | /* Log rule additions and removals */ |
dc9eb698 | 983 | static void audit_log_rule_change(char *action, struct audit_krule *rule, int res) |
5adc8a6a AG |
984 | { |
985 | struct audit_buffer *ab; | |
dc9eb698 EP |
986 | uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(current)); |
987 | u32 sessionid = audit_get_sessionid(current); | |
988 | u32 sid; | |
5adc8a6a | 989 | |
1a6b9f23 EP |
990 | if (!audit_enabled) |
991 | return; | |
992 | ||
5adc8a6a AG |
993 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
994 | if (!ab) | |
995 | return; | |
dc9eb698 EP |
996 | audit_log_format(ab, "auid=%u ses=%u" ,loginuid, sessionid); |
997 | security_task_getsecid(current, &sid); | |
5adc8a6a AG |
998 | if (sid) { |
999 | char *ctx = NULL; | |
1000 | u32 len; | |
2a862b32 | 1001 | if (security_secid_to_secctx(sid, &ctx, &len)) |
5adc8a6a | 1002 | audit_log_format(ab, " ssid=%u", sid); |
2a862b32 | 1003 | else { |
5adc8a6a | 1004 | audit_log_format(ab, " subj=%s", ctx); |
2a862b32 AD |
1005 | security_release_secctx(ctx, len); |
1006 | } | |
5adc8a6a | 1007 | } |
9d960985 EP |
1008 | audit_log_format(ab, " op="); |
1009 | audit_log_string(ab, action); | |
1010 | audit_log_key(ab, rule->filterkey); | |
5adc8a6a AG |
1011 | audit_log_format(ab, " list=%d res=%d", rule->listnr, res); |
1012 | audit_log_end(ab); | |
1013 | } | |
1014 | ||
fe7752ba DW |
1015 | /** |
1016 | * audit_receive_filter - apply all rules to the specified message type | |
1017 | * @type: audit message type | |
1018 | * @pid: target pid for netlink audit messages | |
fe7752ba DW |
1019 | * @seq: netlink audit message sequence (serial) number |
1020 | * @data: payload data | |
93315ed6 | 1021 | * @datasz: size of payload data |
fe7752ba | 1022 | * @loginuid: loginuid of sender |
9f0aecdd | 1023 | * @sessionid: sessionid for netlink audit message |
ce29b682 | 1024 | * @sid: SE Linux Security ID of sender |
fe7752ba | 1025 | */ |
dc9eb698 | 1026 | int audit_receive_filter(int type, int pid, int seq, void *data, size_t datasz) |
fe7752ba DW |
1027 | { |
1028 | struct task_struct *tsk; | |
9044e6bc | 1029 | struct audit_netlink_list *dest; |
93315ed6 AG |
1030 | int err = 0; |
1031 | struct audit_entry *entry; | |
fe7752ba DW |
1032 | |
1033 | switch (type) { | |
93315ed6 | 1034 | case AUDIT_LIST_RULES: |
fe7752ba DW |
1035 | /* We can't just spew out the rules here because we might fill |
1036 | * the available socket buffer space and deadlock waiting for | |
1037 | * auditctl to read from it... which isn't ever going to | |
1038 | * happen if we're actually running in the context of auditctl | |
1039 | * trying to _send_ the stuff */ | |
9ce34218 | 1040 | |
9044e6bc | 1041 | dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); |
fe7752ba DW |
1042 | if (!dest) |
1043 | return -ENOMEM; | |
9044e6bc AV |
1044 | dest->pid = pid; |
1045 | skb_queue_head_init(&dest->q); | |
fe7752ba | 1046 | |
f368c07d | 1047 | mutex_lock(&audit_filter_mutex); |
18900909 | 1048 | audit_list_rules(pid, seq, &dest->q); |
f368c07d | 1049 | mutex_unlock(&audit_filter_mutex); |
9044e6bc AV |
1050 | |
1051 | tsk = kthread_run(audit_send_list, dest, "audit_send_list"); | |
fe7752ba | 1052 | if (IS_ERR(tsk)) { |
9044e6bc | 1053 | skb_queue_purge(&dest->q); |
fe7752ba DW |
1054 | kfree(dest); |
1055 | err = PTR_ERR(tsk); | |
1056 | } | |
1057 | break; | |
93315ed6 | 1058 | case AUDIT_ADD_RULE: |
18900909 | 1059 | entry = audit_data_to_entry(data, datasz); |
93315ed6 AG |
1060 | if (IS_ERR(entry)) |
1061 | return PTR_ERR(entry); | |
1062 | ||
36c4f1b1 | 1063 | err = audit_add_rule(entry); |
dc9eb698 | 1064 | audit_log_rule_change("add rule", &entry->rule, !err); |
5d330108 | 1065 | if (err) |
93315ed6 | 1066 | audit_free_rule(entry); |
fe7752ba | 1067 | break; |
93315ed6 | 1068 | case AUDIT_DEL_RULE: |
18900909 | 1069 | entry = audit_data_to_entry(data, datasz); |
93315ed6 AG |
1070 | if (IS_ERR(entry)) |
1071 | return PTR_ERR(entry); | |
1072 | ||
36c4f1b1 | 1073 | err = audit_del_rule(entry); |
dc9eb698 | 1074 | audit_log_rule_change("remove rule", &entry->rule, !err); |
93315ed6 | 1075 | audit_free_rule(entry); |
fe7752ba DW |
1076 | break; |
1077 | default: | |
1078 | return -EINVAL; | |
1079 | } | |
1080 | ||
1081 | return err; | |
1082 | } | |
1083 | ||
5af75d8d | 1084 | int audit_comparator(u32 left, u32 op, u32 right) |
fe7752ba DW |
1085 | { |
1086 | switch (op) { | |
5af75d8d | 1087 | case Audit_equal: |
fe7752ba | 1088 | return (left == right); |
5af75d8d | 1089 | case Audit_not_equal: |
fe7752ba | 1090 | return (left != right); |
5af75d8d | 1091 | case Audit_lt: |
fe7752ba | 1092 | return (left < right); |
5af75d8d | 1093 | case Audit_le: |
fe7752ba | 1094 | return (left <= right); |
5af75d8d | 1095 | case Audit_gt: |
fe7752ba | 1096 | return (left > right); |
5af75d8d | 1097 | case Audit_ge: |
fe7752ba | 1098 | return (left >= right); |
5af75d8d | 1099 | case Audit_bitmask: |
74f2345b | 1100 | return (left & right); |
5af75d8d | 1101 | case Audit_bittest: |
74f2345b | 1102 | return ((left & right) == right); |
5af75d8d AV |
1103 | default: |
1104 | BUG(); | |
1105 | return 0; | |
fe7752ba DW |
1106 | } |
1107 | } | |
1108 | ||
ca57ec0f EB |
1109 | int audit_uid_comparator(kuid_t left, u32 op, kuid_t right) |
1110 | { | |
1111 | switch (op) { | |
1112 | case Audit_equal: | |
1113 | return uid_eq(left, right); | |
1114 | case Audit_not_equal: | |
1115 | return !uid_eq(left, right); | |
1116 | case Audit_lt: | |
1117 | return uid_lt(left, right); | |
1118 | case Audit_le: | |
1119 | return uid_lte(left, right); | |
1120 | case Audit_gt: | |
1121 | return uid_gt(left, right); | |
1122 | case Audit_ge: | |
1123 | return uid_gte(left, right); | |
1124 | case Audit_bitmask: | |
1125 | case Audit_bittest: | |
1126 | default: | |
1127 | BUG(); | |
1128 | return 0; | |
1129 | } | |
1130 | } | |
1131 | ||
1132 | int audit_gid_comparator(kgid_t left, u32 op, kgid_t right) | |
1133 | { | |
1134 | switch (op) { | |
1135 | case Audit_equal: | |
1136 | return gid_eq(left, right); | |
1137 | case Audit_not_equal: | |
1138 | return !gid_eq(left, right); | |
1139 | case Audit_lt: | |
1140 | return gid_lt(left, right); | |
1141 | case Audit_le: | |
1142 | return gid_lte(left, right); | |
1143 | case Audit_gt: | |
1144 | return gid_gt(left, right); | |
1145 | case Audit_ge: | |
1146 | return gid_gte(left, right); | |
1147 | case Audit_bitmask: | |
1148 | case Audit_bittest: | |
1149 | default: | |
1150 | BUG(); | |
1151 | return 0; | |
1152 | } | |
1153 | } | |
1154 | ||
bfcec708 JL |
1155 | /** |
1156 | * parent_len - find the length of the parent portion of a pathname | |
1157 | * @path: pathname of which to determine length | |
1158 | */ | |
1159 | int parent_len(const char *path) | |
1160 | { | |
1161 | int plen; | |
1162 | const char *p; | |
1163 | ||
1164 | plen = strlen(path); | |
1165 | ||
1166 | if (plen == 0) | |
1167 | return plen; | |
1168 | ||
1169 | /* disregard trailing slashes */ | |
1170 | p = path + plen - 1; | |
1171 | while ((*p == '/') && (p > path)) | |
1172 | p--; | |
1173 | ||
1174 | /* walk backward until we find the next slash or hit beginning */ | |
1175 | while ((*p != '/') && (p > path)) | |
1176 | p--; | |
1177 | ||
1178 | /* did we find a slash? Then increment to include it in path */ | |
1179 | if (*p == '/') | |
1180 | p++; | |
1181 | ||
1182 | return p - path; | |
1183 | } | |
1184 | ||
e3d6b07b JL |
1185 | /** |
1186 | * audit_compare_dname_path - compare given dentry name with last component in | |
1187 | * given path. Return of 0 indicates a match. | |
1188 | * @dname: dentry name that we're comparing | |
1189 | * @path: full pathname that we're comparing | |
1190 | * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL | |
1191 | * here indicates that we must compute this value. | |
1192 | */ | |
1193 | int audit_compare_dname_path(const char *dname, const char *path, int parentlen) | |
f368c07d | 1194 | { |
e3d6b07b | 1195 | int dlen, pathlen; |
f368c07d AG |
1196 | const char *p; |
1197 | ||
f368c07d | 1198 | dlen = strlen(dname); |
29e9a346 EP |
1199 | pathlen = strlen(path); |
1200 | if (pathlen < dlen) | |
f368c07d AG |
1201 | return 1; |
1202 | ||
e3d6b07b | 1203 | parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen; |
29e9a346 | 1204 | if (pathlen - parentlen != dlen) |
f368c07d | 1205 | return 1; |
29e9a346 EP |
1206 | |
1207 | p = path + parentlen; | |
fe7752ba | 1208 | |
f368c07d AG |
1209 | return strncmp(p, dname, dlen); |
1210 | } | |
fe7752ba | 1211 | |
62062cf8 | 1212 | static int audit_filter_user_rules(struct audit_krule *rule, int type, |
fe7752ba DW |
1213 | enum audit_state *state) |
1214 | { | |
1215 | int i; | |
1216 | ||
1217 | for (i = 0; i < rule->field_count; i++) { | |
93315ed6 | 1218 | struct audit_field *f = &rule->fields[i]; |
fe7752ba | 1219 | int result = 0; |
c53fa1ed | 1220 | u32 sid; |
fe7752ba | 1221 | |
93315ed6 | 1222 | switch (f->type) { |
fe7752ba | 1223 | case AUDIT_PID: |
02276bda | 1224 | result = audit_comparator(task_pid_vnr(current), f->op, f->val); |
fe7752ba DW |
1225 | break; |
1226 | case AUDIT_UID: | |
ca57ec0f | 1227 | result = audit_uid_comparator(current_uid(), f->op, f->uid); |
fe7752ba DW |
1228 | break; |
1229 | case AUDIT_GID: | |
ca57ec0f | 1230 | result = audit_gid_comparator(current_gid(), f->op, f->gid); |
fe7752ba DW |
1231 | break; |
1232 | case AUDIT_LOGINUID: | |
ca57ec0f EB |
1233 | result = audit_uid_comparator(audit_get_loginuid(current), |
1234 | f->op, f->uid); | |
fe7752ba | 1235 | break; |
62062cf8 EP |
1236 | case AUDIT_MSGTYPE: |
1237 | result = audit_comparator(type, f->op, f->val); | |
1238 | break; | |
d29be158 MT |
1239 | case AUDIT_SUBJ_USER: |
1240 | case AUDIT_SUBJ_ROLE: | |
1241 | case AUDIT_SUBJ_TYPE: | |
1242 | case AUDIT_SUBJ_SEN: | |
1243 | case AUDIT_SUBJ_CLR: | |
c53fa1ed PM |
1244 | if (f->lsm_rule) { |
1245 | security_task_getsecid(current, &sid); | |
1246 | result = security_audit_rule_match(sid, | |
d29be158 MT |
1247 | f->type, |
1248 | f->op, | |
1249 | f->lsm_rule, | |
1250 | NULL); | |
c53fa1ed | 1251 | } |
d29be158 | 1252 | break; |
fe7752ba DW |
1253 | } |
1254 | ||
1255 | if (!result) | |
1256 | return 0; | |
1257 | } | |
1258 | switch (rule->action) { | |
1259 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; | |
fe7752ba DW |
1260 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; |
1261 | } | |
1262 | return 1; | |
1263 | } | |
1264 | ||
62062cf8 | 1265 | int audit_filter_user(int type) |
fe7752ba | 1266 | { |
11f57ced | 1267 | enum audit_state state = AUDIT_DISABLED; |
fe7752ba | 1268 | struct audit_entry *e; |
fe7752ba DW |
1269 | int ret = 1; |
1270 | ||
1271 | rcu_read_lock(); | |
1272 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { | |
62062cf8 | 1273 | if (audit_filter_user_rules(&e->rule, type, &state)) { |
fe7752ba DW |
1274 | if (state == AUDIT_DISABLED) |
1275 | ret = 0; | |
1276 | break; | |
1277 | } | |
1278 | } | |
1279 | rcu_read_unlock(); | |
1280 | ||
1281 | return ret; /* Audit by default */ | |
1282 | } | |
1283 | ||
1284 | int audit_filter_type(int type) | |
1285 | { | |
1286 | struct audit_entry *e; | |
1287 | int result = 0; | |
9ce34218 | 1288 | |
fe7752ba DW |
1289 | rcu_read_lock(); |
1290 | if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE])) | |
1291 | goto unlock_and_return; | |
1292 | ||
1293 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], | |
1294 | list) { | |
fe7752ba | 1295 | int i; |
93315ed6 AG |
1296 | for (i = 0; i < e->rule.field_count; i++) { |
1297 | struct audit_field *f = &e->rule.fields[i]; | |
1298 | if (f->type == AUDIT_MSGTYPE) { | |
1299 | result = audit_comparator(type, f->op, f->val); | |
fe7752ba DW |
1300 | if (!result) |
1301 | break; | |
1302 | } | |
1303 | } | |
1304 | if (result) | |
1305 | goto unlock_and_return; | |
1306 | } | |
1307 | unlock_and_return: | |
1308 | rcu_read_unlock(); | |
1309 | return result; | |
1310 | } | |
3dc7e315 | 1311 | |
e45aa212 | 1312 | static int update_lsm_rule(struct audit_krule *r) |
1a9d0797 | 1313 | { |
e45aa212 | 1314 | struct audit_entry *entry = container_of(r, struct audit_entry, rule); |
1a9d0797 | 1315 | struct audit_entry *nentry; |
1a9d0797 AV |
1316 | int err = 0; |
1317 | ||
e45aa212 | 1318 | if (!security_audit_rule_known(r)) |
1a9d0797 AV |
1319 | return 0; |
1320 | ||
ae7b8f41 | 1321 | nentry = audit_dupe_rule(r); |
1a9d0797 AV |
1322 | if (IS_ERR(nentry)) { |
1323 | /* save the first error encountered for the | |
1324 | * return value */ | |
1325 | err = PTR_ERR(nentry); | |
1326 | audit_panic("error updating LSM filters"); | |
ae7b8f41 | 1327 | if (r->watch) |
e45aa212 | 1328 | list_del(&r->rlist); |
1a9d0797 | 1329 | list_del_rcu(&entry->list); |
e45aa212 | 1330 | list_del(&r->list); |
1a9d0797 | 1331 | } else { |
ae7b8f41 | 1332 | if (r->watch || r->tree) |
e45aa212 | 1333 | list_replace_init(&r->rlist, &nentry->rule.rlist); |
1a9d0797 | 1334 | list_replace_rcu(&entry->list, &nentry->list); |
e45aa212 | 1335 | list_replace(&r->list, &nentry->rule.list); |
1a9d0797 AV |
1336 | } |
1337 | call_rcu(&entry->rcu, audit_free_rule_rcu); | |
1338 | ||
1339 | return err; | |
1340 | } | |
1341 | ||
04305e4a | 1342 | /* This function will re-initialize the lsm_rule field of all applicable rules. |
d7a96f3a | 1343 | * It will traverse the filter lists serarching for rules that contain LSM |
3dc7e315 | 1344 | * specific filter fields. When such a rule is found, it is copied, the |
d7a96f3a | 1345 | * LSM field is re-initialized, and the old rule is replaced with the |
3dc7e315 | 1346 | * updated rule. */ |
d7a96f3a | 1347 | int audit_update_lsm_rules(void) |
3dc7e315 | 1348 | { |
e45aa212 | 1349 | struct audit_krule *r, *n; |
3dc7e315 DG |
1350 | int i, err = 0; |
1351 | ||
f368c07d AG |
1352 | /* audit_filter_mutex synchronizes the writers */ |
1353 | mutex_lock(&audit_filter_mutex); | |
3dc7e315 DG |
1354 | |
1355 | for (i = 0; i < AUDIT_NR_FILTERS; i++) { | |
e45aa212 AV |
1356 | list_for_each_entry_safe(r, n, &audit_rules_list[i], list) { |
1357 | int res = update_lsm_rule(r); | |
1a9d0797 AV |
1358 | if (!err) |
1359 | err = res; | |
3dc7e315 DG |
1360 | } |
1361 | } | |
f368c07d | 1362 | mutex_unlock(&audit_filter_mutex); |
3dc7e315 DG |
1363 | |
1364 | return err; | |
1365 | } |