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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 | ||
f952d10f RGB |
22 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
23 | ||
fe7752ba DW |
24 | #include <linux/kernel.h> |
25 | #include <linux/audit.h> | |
26 | #include <linux/kthread.h> | |
f368c07d AG |
27 | #include <linux/mutex.h> |
28 | #include <linux/fs.h> | |
29 | #include <linux/namei.h> | |
fe7752ba | 30 | #include <linux/netlink.h> |
f368c07d | 31 | #include <linux/sched.h> |
5a0e3ad6 | 32 | #include <linux/slab.h> |
2a862b32 | 33 | #include <linux/security.h> |
48095d99 | 34 | #include <net/net_namespace.h> |
6f285b19 | 35 | #include <net/sock.h> |
fe7752ba DW |
36 | #include "audit.h" |
37 | ||
f368c07d AG |
38 | /* |
39 | * Locking model: | |
40 | * | |
41 | * audit_filter_mutex: | |
42 | * Synchronizes writes and blocking reads of audit's filterlist | |
43 | * data. Rcu is used to traverse the filterlist and access | |
44 | * contents of structs audit_entry, audit_watch and opaque | |
d7a96f3a | 45 | * LSM rules during filtering. If modified, these structures |
f368c07d AG |
46 | * must be copied and replace their counterparts in the filterlist. |
47 | * An audit_parent struct is not accessed during filtering, so may | |
48 | * be written directly provided audit_filter_mutex is held. | |
49 | */ | |
50 | ||
f368c07d | 51 | /* Audit filter lists, defined in <linux/audit.h> */ |
fe7752ba DW |
52 | struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { |
53 | LIST_HEAD_INIT(audit_filter_list[0]), | |
54 | LIST_HEAD_INIT(audit_filter_list[1]), | |
55 | LIST_HEAD_INIT(audit_filter_list[2]), | |
56 | LIST_HEAD_INIT(audit_filter_list[3]), | |
57 | LIST_HEAD_INIT(audit_filter_list[4]), | |
58 | LIST_HEAD_INIT(audit_filter_list[5]), | |
59 | #if AUDIT_NR_FILTERS != 6 | |
60 | #error Fix audit_filter_list initialiser | |
61 | #endif | |
62 | }; | |
e45aa212 AV |
63 | static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = { |
64 | LIST_HEAD_INIT(audit_rules_list[0]), | |
65 | LIST_HEAD_INIT(audit_rules_list[1]), | |
66 | LIST_HEAD_INIT(audit_rules_list[2]), | |
67 | LIST_HEAD_INIT(audit_rules_list[3]), | |
68 | LIST_HEAD_INIT(audit_rules_list[4]), | |
69 | LIST_HEAD_INIT(audit_rules_list[5]), | |
70 | }; | |
fe7752ba | 71 | |
74c3cbe3 | 72 | DEFINE_MUTEX(audit_filter_mutex); |
f368c07d | 73 | |
219ca394 RGB |
74 | static void audit_free_lsm_field(struct audit_field *f) |
75 | { | |
76 | switch (f->type) { | |
77 | case AUDIT_SUBJ_USER: | |
78 | case AUDIT_SUBJ_ROLE: | |
79 | case AUDIT_SUBJ_TYPE: | |
80 | case AUDIT_SUBJ_SEN: | |
81 | case AUDIT_SUBJ_CLR: | |
82 | case AUDIT_OBJ_USER: | |
83 | case AUDIT_OBJ_ROLE: | |
84 | case AUDIT_OBJ_TYPE: | |
85 | case AUDIT_OBJ_LEV_LOW: | |
86 | case AUDIT_OBJ_LEV_HIGH: | |
87 | kfree(f->lsm_str); | |
88 | security_audit_rule_free(f->lsm_rule); | |
89 | } | |
90 | } | |
91 | ||
93315ed6 | 92 | static inline void audit_free_rule(struct audit_entry *e) |
fe7752ba | 93 | { |
3dc7e315 | 94 | int i; |
c28bb7da | 95 | struct audit_krule *erule = &e->rule; |
ae7b8f41 | 96 | |
f368c07d | 97 | /* some rules don't have associated watches */ |
c28bb7da ZX |
98 | if (erule->watch) |
99 | audit_put_watch(erule->watch); | |
100 | if (erule->fields) | |
219ca394 RGB |
101 | for (i = 0; i < erule->field_count; i++) |
102 | audit_free_lsm_field(&erule->fields[i]); | |
c28bb7da ZX |
103 | kfree(erule->fields); |
104 | kfree(erule->filterkey); | |
93315ed6 AG |
105 | kfree(e); |
106 | } | |
107 | ||
74c3cbe3 | 108 | void audit_free_rule_rcu(struct rcu_head *head) |
93315ed6 AG |
109 | { |
110 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); | |
111 | audit_free_rule(e); | |
112 | } | |
113 | ||
3dc7e315 DG |
114 | /* Initialize an audit filterlist entry. */ |
115 | static inline struct audit_entry *audit_init_entry(u32 field_count) | |
116 | { | |
117 | struct audit_entry *entry; | |
118 | struct audit_field *fields; | |
119 | ||
120 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); | |
121 | if (unlikely(!entry)) | |
122 | return NULL; | |
123 | ||
124 | fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL); | |
125 | if (unlikely(!fields)) { | |
126 | kfree(entry); | |
127 | return NULL; | |
128 | } | |
129 | entry->rule.fields = fields; | |
130 | ||
131 | return entry; | |
132 | } | |
133 | ||
93315ed6 AG |
134 | /* Unpack a filter field's string representation from user-space |
135 | * buffer. */ | |
74c3cbe3 | 136 | char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
93315ed6 AG |
137 | { |
138 | char *str; | |
139 | ||
140 | if (!*bufp || (len == 0) || (len > *remain)) | |
141 | return ERR_PTR(-EINVAL); | |
142 | ||
143 | /* Of the currently implemented string fields, PATH_MAX | |
144 | * defines the longest valid length. | |
145 | */ | |
146 | if (len > PATH_MAX) | |
147 | return ERR_PTR(-ENAMETOOLONG); | |
148 | ||
149 | str = kmalloc(len + 1, GFP_KERNEL); | |
150 | if (unlikely(!str)) | |
151 | return ERR_PTR(-ENOMEM); | |
152 | ||
153 | memcpy(str, *bufp, len); | |
154 | str[len] = 0; | |
155 | *bufp += len; | |
156 | *remain -= len; | |
157 | ||
158 | return str; | |
159 | } | |
160 | ||
f368c07d AG |
161 | /* Translate an inode field to kernel respresentation. */ |
162 | static inline int audit_to_inode(struct audit_krule *krule, | |
163 | struct audit_field *f) | |
164 | { | |
165 | if (krule->listnr != AUDIT_FILTER_EXIT || | |
3639f170 | 166 | krule->inode_f || krule->watch || krule->tree || |
5af75d8d | 167 | (f->op != Audit_equal && f->op != Audit_not_equal)) |
f368c07d AG |
168 | return -EINVAL; |
169 | ||
170 | krule->inode_f = f; | |
171 | return 0; | |
172 | } | |
173 | ||
b915543b AV |
174 | static __u32 *classes[AUDIT_SYSCALL_CLASSES]; |
175 | ||
176 | int __init audit_register_class(int class, unsigned *list) | |
177 | { | |
178 | __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL); | |
179 | if (!p) | |
180 | return -ENOMEM; | |
181 | while (*list != ~0U) { | |
182 | unsigned n = *list++; | |
183 | if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) { | |
184 | kfree(p); | |
185 | return -EINVAL; | |
186 | } | |
187 | p[AUDIT_WORD(n)] |= AUDIT_BIT(n); | |
188 | } | |
189 | if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) { | |
190 | kfree(p); | |
191 | return -EINVAL; | |
192 | } | |
193 | classes[class] = p; | |
194 | return 0; | |
195 | } | |
196 | ||
55669bfa AV |
197 | int audit_match_class(int class, unsigned syscall) |
198 | { | |
c926e4f4 | 199 | if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32)) |
55669bfa AV |
200 | return 0; |
201 | if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class])) | |
202 | return 0; | |
203 | return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall); | |
204 | } | |
205 | ||
327b9eeb | 206 | #ifdef CONFIG_AUDITSYSCALL |
e54dc243 AG |
207 | static inline int audit_match_class_bits(int class, u32 *mask) |
208 | { | |
209 | int i; | |
210 | ||
211 | if (classes[class]) { | |
212 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
213 | if (mask[i] & classes[class][i]) | |
214 | return 0; | |
215 | } | |
216 | return 1; | |
217 | } | |
218 | ||
219 | static int audit_match_signal(struct audit_entry *entry) | |
220 | { | |
221 | struct audit_field *arch = entry->rule.arch_f; | |
222 | ||
223 | if (!arch) { | |
224 | /* When arch is unspecified, we must check both masks on biarch | |
225 | * as syscall number alone is ambiguous. */ | |
226 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, | |
227 | entry->rule.mask) && | |
228 | audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, | |
229 | entry->rule.mask)); | |
230 | } | |
231 | ||
232 | switch(audit_classify_arch(arch->val)) { | |
233 | case 0: /* native */ | |
234 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, | |
235 | entry->rule.mask)); | |
236 | case 1: /* 32bit on biarch */ | |
237 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, | |
238 | entry->rule.mask)); | |
239 | default: | |
240 | return 1; | |
241 | } | |
242 | } | |
327b9eeb | 243 | #endif |
e54dc243 | 244 | |
93315ed6 | 245 | /* Common user-space to kernel rule translation. */ |
56c4911a | 246 | static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule) |
93315ed6 AG |
247 | { |
248 | unsigned listnr; | |
249 | struct audit_entry *entry; | |
93315ed6 AG |
250 | int i, err; |
251 | ||
252 | err = -EINVAL; | |
253 | listnr = rule->flags & ~AUDIT_FILTER_PREPEND; | |
254 | switch(listnr) { | |
255 | default: | |
256 | goto exit_err; | |
93315ed6 AG |
257 | #ifdef CONFIG_AUDITSYSCALL |
258 | case AUDIT_FILTER_ENTRY: | |
7ff68e53 EP |
259 | if (rule->action == AUDIT_ALWAYS) |
260 | goto exit_err; | |
93315ed6 AG |
261 | case AUDIT_FILTER_EXIT: |
262 | case AUDIT_FILTER_TASK: | |
263 | #endif | |
7ff68e53 EP |
264 | case AUDIT_FILTER_USER: |
265 | case AUDIT_FILTER_TYPE: | |
93315ed6 AG |
266 | ; |
267 | } | |
014149cc | 268 | if (unlikely(rule->action == AUDIT_POSSIBLE)) { |
f952d10f | 269 | pr_err("AUDIT_POSSIBLE is deprecated\n"); |
014149cc AV |
270 | goto exit_err; |
271 | } | |
272 | if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS) | |
93315ed6 AG |
273 | goto exit_err; |
274 | if (rule->field_count > AUDIT_MAX_FIELDS) | |
275 | goto exit_err; | |
276 | ||
277 | err = -ENOMEM; | |
3dc7e315 DG |
278 | entry = audit_init_entry(rule->field_count); |
279 | if (!entry) | |
93315ed6 | 280 | goto exit_err; |
93315ed6 AG |
281 | |
282 | entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; | |
283 | entry->rule.listnr = listnr; | |
284 | entry->rule.action = rule->action; | |
285 | entry->rule.field_count = rule->field_count; | |
93315ed6 AG |
286 | |
287 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
288 | entry->rule.mask[i] = rule->mask[i]; | |
289 | ||
b915543b AV |
290 | for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) { |
291 | int bit = AUDIT_BITMASK_SIZE * 32 - i - 1; | |
292 | __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)]; | |
293 | __u32 *class; | |
294 | ||
295 | if (!(*p & AUDIT_BIT(bit))) | |
296 | continue; | |
297 | *p &= ~AUDIT_BIT(bit); | |
298 | class = classes[i]; | |
299 | if (class) { | |
300 | int j; | |
301 | for (j = 0; j < AUDIT_BITMASK_SIZE; j++) | |
302 | entry->rule.mask[j] |= class[j]; | |
303 | } | |
304 | } | |
305 | ||
93315ed6 AG |
306 | return entry; |
307 | ||
308 | exit_err: | |
309 | return ERR_PTR(err); | |
310 | } | |
311 | ||
5af75d8d AV |
312 | static u32 audit_ops[] = |
313 | { | |
314 | [Audit_equal] = AUDIT_EQUAL, | |
315 | [Audit_not_equal] = AUDIT_NOT_EQUAL, | |
316 | [Audit_bitmask] = AUDIT_BIT_MASK, | |
317 | [Audit_bittest] = AUDIT_BIT_TEST, | |
318 | [Audit_lt] = AUDIT_LESS_THAN, | |
319 | [Audit_gt] = AUDIT_GREATER_THAN, | |
320 | [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL, | |
321 | [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL, | |
322 | }; | |
323 | ||
324 | static u32 audit_to_op(u32 op) | |
325 | { | |
326 | u32 n; | |
327 | for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++) | |
328 | ; | |
329 | return n; | |
330 | } | |
331 | ||
ab61d38e | 332 | /* check if an audit field is valid */ |
62062cf8 | 333 | static int audit_field_valid(struct audit_entry *entry, struct audit_field *f) |
93315ed6 | 334 | { |
62062cf8 EP |
335 | switch(f->type) { |
336 | case AUDIT_MSGTYPE: | |
337 | if (entry->rule.listnr != AUDIT_FILTER_TYPE && | |
338 | entry->rule.listnr != AUDIT_FILTER_USER) | |
339 | return -EINVAL; | |
340 | break; | |
341 | }; | |
93315ed6 | 342 | |
ab61d38e EP |
343 | switch(f->type) { |
344 | default: | |
345 | return -EINVAL; | |
346 | case AUDIT_UID: | |
347 | case AUDIT_EUID: | |
348 | case AUDIT_SUID: | |
349 | case AUDIT_FSUID: | |
350 | case AUDIT_LOGINUID: | |
351 | case AUDIT_OBJ_UID: | |
352 | case AUDIT_GID: | |
353 | case AUDIT_EGID: | |
354 | case AUDIT_SGID: | |
355 | case AUDIT_FSGID: | |
356 | case AUDIT_OBJ_GID: | |
357 | case AUDIT_PID: | |
358 | case AUDIT_PERS: | |
359 | case AUDIT_MSGTYPE: | |
360 | case AUDIT_PPID: | |
361 | case AUDIT_DEVMAJOR: | |
362 | case AUDIT_DEVMINOR: | |
363 | case AUDIT_EXIT: | |
364 | case AUDIT_SUCCESS: | |
78122037 | 365 | case AUDIT_INODE: |
ab61d38e EP |
366 | /* bit ops are only useful on syscall args */ |
367 | if (f->op == Audit_bitmask || f->op == Audit_bittest) | |
368 | return -EINVAL; | |
369 | break; | |
370 | case AUDIT_ARG0: | |
371 | case AUDIT_ARG1: | |
372 | case AUDIT_ARG2: | |
373 | case AUDIT_ARG3: | |
374 | case AUDIT_SUBJ_USER: | |
375 | case AUDIT_SUBJ_ROLE: | |
376 | case AUDIT_SUBJ_TYPE: | |
377 | case AUDIT_SUBJ_SEN: | |
378 | case AUDIT_SUBJ_CLR: | |
379 | case AUDIT_OBJ_USER: | |
380 | case AUDIT_OBJ_ROLE: | |
381 | case AUDIT_OBJ_TYPE: | |
382 | case AUDIT_OBJ_LEV_LOW: | |
383 | case AUDIT_OBJ_LEV_HIGH: | |
384 | case AUDIT_WATCH: | |
385 | case AUDIT_DIR: | |
386 | case AUDIT_FILTERKEY: | |
387 | break; | |
780a7654 EB |
388 | case AUDIT_LOGINUID_SET: |
389 | if ((f->val != 0) && (f->val != 1)) | |
390 | return -EINVAL; | |
391 | /* FALL THROUGH */ | |
ab61d38e EP |
392 | case AUDIT_ARCH: |
393 | if (f->op != Audit_not_equal && f->op != Audit_equal) | |
394 | return -EINVAL; | |
395 | break; | |
396 | case AUDIT_PERM: | |
397 | if (f->val & ~15) | |
398 | return -EINVAL; | |
399 | break; | |
400 | case AUDIT_FILETYPE: | |
401 | if (f->val & ~S_IFMT) | |
402 | return -EINVAL; | |
403 | break; | |
404 | case AUDIT_FIELD_COMPARE: | |
405 | if (f->val > AUDIT_MAX_FIELD_COMPARE) | |
406 | return -EINVAL; | |
407 | break; | |
408 | }; | |
62062cf8 | 409 | return 0; |
fe7752ba DW |
410 | } |
411 | ||
93315ed6 AG |
412 | /* Translate struct audit_rule_data to kernel's rule respresentation. */ |
413 | static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, | |
414 | size_t datasz) | |
fe7752ba | 415 | { |
93315ed6 AG |
416 | int err = 0; |
417 | struct audit_entry *entry; | |
418 | void *bufp; | |
3dc7e315 | 419 | size_t remain = datasz - sizeof(struct audit_rule_data); |
fe7752ba | 420 | int i; |
3dc7e315 | 421 | char *str; |
fe7752ba | 422 | |
56c4911a | 423 | entry = audit_to_entry_common(data); |
93315ed6 AG |
424 | if (IS_ERR(entry)) |
425 | goto exit_nofree; | |
fe7752ba | 426 | |
93315ed6 AG |
427 | bufp = data->buf; |
428 | entry->rule.vers_ops = 2; | |
429 | for (i = 0; i < data->field_count; i++) { | |
430 | struct audit_field *f = &entry->rule.fields[i]; | |
431 | ||
432 | err = -EINVAL; | |
5af75d8d AV |
433 | |
434 | f->op = audit_to_op(data->fieldflags[i]); | |
435 | if (f->op == Audit_bad) | |
93315ed6 AG |
436 | goto exit_free; |
437 | ||
93315ed6 | 438 | f->type = data->fields[i]; |
3dc7e315 | 439 | f->val = data->values[i]; |
62062cf8 | 440 | |
780a7654 | 441 | /* Support legacy tests for a valid loginuid */ |
42f74461 | 442 | if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) { |
780a7654 EB |
443 | f->type = AUDIT_LOGINUID_SET; |
444 | f->val = 0; | |
445 | } | |
446 | ||
62062cf8 EP |
447 | err = audit_field_valid(entry, f); |
448 | if (err) | |
449 | goto exit_free; | |
450 | ||
451 | err = -EINVAL; | |
ab61d38e | 452 | switch (f->type) { |
780a7654 | 453 | case AUDIT_LOGINUID: |
0a73dccc AV |
454 | case AUDIT_UID: |
455 | case AUDIT_EUID: | |
456 | case AUDIT_SUID: | |
457 | case AUDIT_FSUID: | |
ca57ec0f | 458 | case AUDIT_OBJ_UID: |
ca57ec0f EB |
459 | f->uid = make_kuid(current_user_ns(), f->val); |
460 | if (!uid_valid(f->uid)) | |
461 | goto exit_free; | |
462 | break; | |
0a73dccc AV |
463 | case AUDIT_GID: |
464 | case AUDIT_EGID: | |
465 | case AUDIT_SGID: | |
466 | case AUDIT_FSGID: | |
ca57ec0f | 467 | case AUDIT_OBJ_GID: |
ca57ec0f EB |
468 | f->gid = make_kgid(current_user_ns(), f->val); |
469 | if (!gid_valid(f->gid)) | |
470 | goto exit_free; | |
471 | break; | |
e54dc243 AG |
472 | case AUDIT_ARCH: |
473 | entry->rule.arch_f = f; | |
474 | break; | |
3a6b9f85 DG |
475 | case AUDIT_SUBJ_USER: |
476 | case AUDIT_SUBJ_ROLE: | |
477 | case AUDIT_SUBJ_TYPE: | |
478 | case AUDIT_SUBJ_SEN: | |
479 | case AUDIT_SUBJ_CLR: | |
6e5a2d1d DG |
480 | case AUDIT_OBJ_USER: |
481 | case AUDIT_OBJ_ROLE: | |
482 | case AUDIT_OBJ_TYPE: | |
483 | case AUDIT_OBJ_LEV_LOW: | |
484 | case AUDIT_OBJ_LEV_HIGH: | |
3dc7e315 DG |
485 | str = audit_unpack_string(&bufp, &remain, f->val); |
486 | if (IS_ERR(str)) | |
487 | goto exit_free; | |
488 | entry->rule.buflen += f->val; | |
489 | ||
d7a96f3a | 490 | err = security_audit_rule_init(f->type, f->op, str, |
04305e4a | 491 | (void **)&f->lsm_rule); |
3dc7e315 DG |
492 | /* Keep currently invalid fields around in case they |
493 | * become valid after a policy reload. */ | |
494 | if (err == -EINVAL) { | |
f952d10f RGB |
495 | pr_warn("audit rule for LSM \'%s\' is invalid\n", |
496 | str); | |
3dc7e315 DG |
497 | err = 0; |
498 | } | |
499 | if (err) { | |
500 | kfree(str); | |
501 | goto exit_free; | |
502 | } else | |
04305e4a | 503 | f->lsm_str = str; |
3dc7e315 | 504 | break; |
f368c07d AG |
505 | case AUDIT_WATCH: |
506 | str = audit_unpack_string(&bufp, &remain, f->val); | |
507 | if (IS_ERR(str)) | |
508 | goto exit_free; | |
509 | entry->rule.buflen += f->val; | |
510 | ||
511 | err = audit_to_watch(&entry->rule, str, f->val, f->op); | |
512 | if (err) { | |
513 | kfree(str); | |
514 | goto exit_free; | |
515 | } | |
516 | break; | |
74c3cbe3 AV |
517 | case AUDIT_DIR: |
518 | str = audit_unpack_string(&bufp, &remain, f->val); | |
519 | if (IS_ERR(str)) | |
520 | goto exit_free; | |
521 | entry->rule.buflen += f->val; | |
522 | ||
523 | err = audit_make_tree(&entry->rule, str, f->op); | |
524 | kfree(str); | |
525 | if (err) | |
526 | goto exit_free; | |
527 | break; | |
f368c07d AG |
528 | case AUDIT_INODE: |
529 | err = audit_to_inode(&entry->rule, f); | |
530 | if (err) | |
531 | goto exit_free; | |
532 | break; | |
5adc8a6a | 533 | case AUDIT_FILTERKEY: |
5adc8a6a AG |
534 | if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN) |
535 | goto exit_free; | |
536 | str = audit_unpack_string(&bufp, &remain, f->val); | |
537 | if (IS_ERR(str)) | |
538 | goto exit_free; | |
539 | entry->rule.buflen += f->val; | |
540 | entry->rule.filterkey = str; | |
541 | break; | |
f368c07d AG |
542 | } |
543 | } | |
544 | ||
5af75d8d AV |
545 | if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) |
546 | entry->rule.inode_f = NULL; | |
93315ed6 AG |
547 | |
548 | exit_nofree: | |
549 | return entry; | |
550 | ||
551 | exit_free: | |
373e0f34 CG |
552 | if (entry->rule.watch) |
553 | audit_put_watch(entry->rule.watch); /* matches initial get */ | |
554 | if (entry->rule.tree) | |
555 | audit_put_tree(entry->rule.tree); /* that's the temporary one */ | |
93315ed6 AG |
556 | audit_free_rule(entry); |
557 | return ERR_PTR(err); | |
558 | } | |
559 | ||
560 | /* Pack a filter field's string representation into data block. */ | |
74c3cbe3 | 561 | static inline size_t audit_pack_string(void **bufp, const char *str) |
93315ed6 AG |
562 | { |
563 | size_t len = strlen(str); | |
564 | ||
565 | memcpy(*bufp, str, len); | |
566 | *bufp += len; | |
567 | ||
568 | return len; | |
569 | } | |
570 | ||
93315ed6 AG |
571 | /* Translate kernel rule respresentation to struct audit_rule_data. */ |
572 | static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) | |
573 | { | |
574 | struct audit_rule_data *data; | |
575 | void *bufp; | |
576 | int i; | |
577 | ||
578 | data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); | |
579 | if (unlikely(!data)) | |
0a3b483e | 580 | return NULL; |
93315ed6 AG |
581 | memset(data, 0, sizeof(*data)); |
582 | ||
583 | data->flags = krule->flags | krule->listnr; | |
584 | data->action = krule->action; | |
585 | data->field_count = krule->field_count; | |
586 | bufp = data->buf; | |
587 | for (i = 0; i < data->field_count; i++) { | |
588 | struct audit_field *f = &krule->fields[i]; | |
589 | ||
590 | data->fields[i] = f->type; | |
5af75d8d | 591 | data->fieldflags[i] = audit_ops[f->op]; |
93315ed6 | 592 | switch(f->type) { |
3a6b9f85 DG |
593 | case AUDIT_SUBJ_USER: |
594 | case AUDIT_SUBJ_ROLE: | |
595 | case AUDIT_SUBJ_TYPE: | |
596 | case AUDIT_SUBJ_SEN: | |
597 | case AUDIT_SUBJ_CLR: | |
6e5a2d1d DG |
598 | case AUDIT_OBJ_USER: |
599 | case AUDIT_OBJ_ROLE: | |
600 | case AUDIT_OBJ_TYPE: | |
601 | case AUDIT_OBJ_LEV_LOW: | |
602 | case AUDIT_OBJ_LEV_HIGH: | |
3dc7e315 | 603 | data->buflen += data->values[i] = |
04305e4a | 604 | audit_pack_string(&bufp, f->lsm_str); |
3dc7e315 | 605 | break; |
f368c07d AG |
606 | case AUDIT_WATCH: |
607 | data->buflen += data->values[i] = | |
cfcad62c EP |
608 | audit_pack_string(&bufp, |
609 | audit_watch_path(krule->watch)); | |
f368c07d | 610 | break; |
74c3cbe3 AV |
611 | case AUDIT_DIR: |
612 | data->buflen += data->values[i] = | |
613 | audit_pack_string(&bufp, | |
614 | audit_tree_path(krule->tree)); | |
615 | break; | |
5adc8a6a AG |
616 | case AUDIT_FILTERKEY: |
617 | data->buflen += data->values[i] = | |
618 | audit_pack_string(&bufp, krule->filterkey); | |
619 | break; | |
93315ed6 AG |
620 | default: |
621 | data->values[i] = f->val; | |
622 | } | |
623 | } | |
624 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; | |
625 | ||
626 | return data; | |
627 | } | |
628 | ||
629 | /* Compare two rules in kernel format. Considered success if rules | |
630 | * don't match. */ | |
631 | static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) | |
632 | { | |
633 | int i; | |
634 | ||
635 | if (a->flags != b->flags || | |
636 | a->listnr != b->listnr || | |
637 | a->action != b->action || | |
638 | a->field_count != b->field_count) | |
fe7752ba DW |
639 | return 1; |
640 | ||
641 | for (i = 0; i < a->field_count; i++) { | |
93315ed6 AG |
642 | if (a->fields[i].type != b->fields[i].type || |
643 | a->fields[i].op != b->fields[i].op) | |
fe7752ba | 644 | return 1; |
93315ed6 AG |
645 | |
646 | switch(a->fields[i].type) { | |
3a6b9f85 DG |
647 | case AUDIT_SUBJ_USER: |
648 | case AUDIT_SUBJ_ROLE: | |
649 | case AUDIT_SUBJ_TYPE: | |
650 | case AUDIT_SUBJ_SEN: | |
651 | case AUDIT_SUBJ_CLR: | |
6e5a2d1d DG |
652 | case AUDIT_OBJ_USER: |
653 | case AUDIT_OBJ_ROLE: | |
654 | case AUDIT_OBJ_TYPE: | |
655 | case AUDIT_OBJ_LEV_LOW: | |
656 | case AUDIT_OBJ_LEV_HIGH: | |
04305e4a | 657 | if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str)) |
3dc7e315 DG |
658 | return 1; |
659 | break; | |
f368c07d | 660 | case AUDIT_WATCH: |
cfcad62c EP |
661 | if (strcmp(audit_watch_path(a->watch), |
662 | audit_watch_path(b->watch))) | |
f368c07d AG |
663 | return 1; |
664 | break; | |
74c3cbe3 AV |
665 | case AUDIT_DIR: |
666 | if (strcmp(audit_tree_path(a->tree), | |
667 | audit_tree_path(b->tree))) | |
668 | return 1; | |
669 | break; | |
5adc8a6a AG |
670 | case AUDIT_FILTERKEY: |
671 | /* both filterkeys exist based on above type compare */ | |
672 | if (strcmp(a->filterkey, b->filterkey)) | |
673 | return 1; | |
674 | break; | |
ca57ec0f EB |
675 | case AUDIT_UID: |
676 | case AUDIT_EUID: | |
677 | case AUDIT_SUID: | |
678 | case AUDIT_FSUID: | |
679 | case AUDIT_LOGINUID: | |
680 | case AUDIT_OBJ_UID: | |
681 | if (!uid_eq(a->fields[i].uid, b->fields[i].uid)) | |
682 | return 1; | |
683 | break; | |
684 | case AUDIT_GID: | |
685 | case AUDIT_EGID: | |
686 | case AUDIT_SGID: | |
687 | case AUDIT_FSGID: | |
688 | case AUDIT_OBJ_GID: | |
689 | if (!gid_eq(a->fields[i].gid, b->fields[i].gid)) | |
690 | return 1; | |
691 | break; | |
93315ed6 AG |
692 | default: |
693 | if (a->fields[i].val != b->fields[i].val) | |
694 | return 1; | |
695 | } | |
fe7752ba DW |
696 | } |
697 | ||
698 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
699 | if (a->mask[i] != b->mask[i]) | |
700 | return 1; | |
701 | ||
702 | return 0; | |
703 | } | |
704 | ||
04305e4a | 705 | /* Duplicate LSM field information. The lsm_rule is opaque, so must be |
3dc7e315 | 706 | * re-initialized. */ |
d7a96f3a | 707 | static inline int audit_dupe_lsm_field(struct audit_field *df, |
3dc7e315 DG |
708 | struct audit_field *sf) |
709 | { | |
710 | int ret = 0; | |
04305e4a | 711 | char *lsm_str; |
3dc7e315 | 712 | |
04305e4a AD |
713 | /* our own copy of lsm_str */ |
714 | lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL); | |
715 | if (unlikely(!lsm_str)) | |
3e1fbd12 | 716 | return -ENOMEM; |
04305e4a | 717 | df->lsm_str = lsm_str; |
3dc7e315 | 718 | |
04305e4a AD |
719 | /* our own (refreshed) copy of lsm_rule */ |
720 | ret = security_audit_rule_init(df->type, df->op, df->lsm_str, | |
721 | (void **)&df->lsm_rule); | |
3dc7e315 DG |
722 | /* Keep currently invalid fields around in case they |
723 | * become valid after a policy reload. */ | |
724 | if (ret == -EINVAL) { | |
f952d10f RGB |
725 | pr_warn("audit rule for LSM \'%s\' is invalid\n", |
726 | df->lsm_str); | |
3dc7e315 DG |
727 | ret = 0; |
728 | } | |
729 | ||
730 | return ret; | |
731 | } | |
732 | ||
733 | /* Duplicate an audit rule. This will be a deep copy with the exception | |
d7a96f3a | 734 | * of the watch - that pointer is carried over. The LSM specific fields |
3dc7e315 | 735 | * will be updated in the copy. The point is to be able to replace the old |
f368c07d AG |
736 | * rule with the new rule in the filterlist, then free the old rule. |
737 | * The rlist element is undefined; list manipulations are handled apart from | |
738 | * the initial copy. */ | |
ae7b8f41 | 739 | struct audit_entry *audit_dupe_rule(struct audit_krule *old) |
3dc7e315 DG |
740 | { |
741 | u32 fcount = old->field_count; | |
742 | struct audit_entry *entry; | |
743 | struct audit_krule *new; | |
5adc8a6a | 744 | char *fk; |
3dc7e315 DG |
745 | int i, err = 0; |
746 | ||
747 | entry = audit_init_entry(fcount); | |
748 | if (unlikely(!entry)) | |
749 | return ERR_PTR(-ENOMEM); | |
750 | ||
751 | new = &entry->rule; | |
752 | new->vers_ops = old->vers_ops; | |
753 | new->flags = old->flags; | |
754 | new->listnr = old->listnr; | |
755 | new->action = old->action; | |
756 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
757 | new->mask[i] = old->mask[i]; | |
0590b933 | 758 | new->prio = old->prio; |
3dc7e315 | 759 | new->buflen = old->buflen; |
f368c07d | 760 | new->inode_f = old->inode_f; |
3dc7e315 | 761 | new->field_count = old->field_count; |
ae7b8f41 | 762 | |
74c3cbe3 AV |
763 | /* |
764 | * note that we are OK with not refcounting here; audit_match_tree() | |
765 | * never dereferences tree and we can't get false positives there | |
766 | * since we'd have to have rule gone from the list *and* removed | |
767 | * before the chunks found by lookup had been allocated, i.e. before | |
768 | * the beginning of list scan. | |
769 | */ | |
770 | new->tree = old->tree; | |
3dc7e315 DG |
771 | memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); |
772 | ||
04305e4a | 773 | /* deep copy this information, updating the lsm_rule fields, because |
3dc7e315 DG |
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) { | |
3a6b9f85 DG |
777 | case AUDIT_SUBJ_USER: |
778 | case AUDIT_SUBJ_ROLE: | |
779 | case AUDIT_SUBJ_TYPE: | |
780 | case AUDIT_SUBJ_SEN: | |
781 | case AUDIT_SUBJ_CLR: | |
6e5a2d1d DG |
782 | case AUDIT_OBJ_USER: |
783 | case AUDIT_OBJ_ROLE: | |
784 | case AUDIT_OBJ_TYPE: | |
785 | case AUDIT_OBJ_LEV_LOW: | |
786 | case AUDIT_OBJ_LEV_HIGH: | |
d7a96f3a | 787 | err = audit_dupe_lsm_field(&new->fields[i], |
3dc7e315 | 788 | &old->fields[i]); |
5adc8a6a AG |
789 | break; |
790 | case AUDIT_FILTERKEY: | |
791 | fk = kstrdup(old->filterkey, GFP_KERNEL); | |
792 | if (unlikely(!fk)) | |
793 | err = -ENOMEM; | |
794 | else | |
795 | new->filterkey = fk; | |
3dc7e315 DG |
796 | } |
797 | if (err) { | |
798 | audit_free_rule(entry); | |
799 | return ERR_PTR(err); | |
800 | } | |
801 | } | |
802 | ||
ae7b8f41 EP |
803 | if (old->watch) { |
804 | audit_get_watch(old->watch); | |
805 | new->watch = old->watch; | |
f368c07d AG |
806 | } |
807 | ||
3dc7e315 DG |
808 | return entry; |
809 | } | |
810 | ||
f368c07d AG |
811 | /* Find an existing audit rule. |
812 | * Caller must hold audit_filter_mutex to prevent stale rule data. */ | |
813 | static struct audit_entry *audit_find_rule(struct audit_entry *entry, | |
36c4f1b1 | 814 | struct list_head **p) |
f368c07d AG |
815 | { |
816 | struct audit_entry *e, *found = NULL; | |
36c4f1b1 | 817 | struct list_head *list; |
f368c07d AG |
818 | int h; |
819 | ||
36c4f1b1 AV |
820 | if (entry->rule.inode_f) { |
821 | h = audit_hash_ino(entry->rule.inode_f->val); | |
822 | *p = list = &audit_inode_hash[h]; | |
823 | } else if (entry->rule.watch) { | |
f368c07d AG |
824 | /* we don't know the inode number, so must walk entire hash */ |
825 | for (h = 0; h < AUDIT_INODE_BUCKETS; h++) { | |
826 | list = &audit_inode_hash[h]; | |
827 | list_for_each_entry(e, list, list) | |
828 | if (!audit_compare_rule(&entry->rule, &e->rule)) { | |
829 | found = e; | |
830 | goto out; | |
831 | } | |
832 | } | |
833 | goto out; | |
36c4f1b1 AV |
834 | } else { |
835 | *p = list = &audit_filter_list[entry->rule.listnr]; | |
f368c07d AG |
836 | } |
837 | ||
838 | list_for_each_entry(e, list, list) | |
839 | if (!audit_compare_rule(&entry->rule, &e->rule)) { | |
840 | found = e; | |
841 | goto out; | |
842 | } | |
843 | ||
844 | out: | |
845 | return found; | |
846 | } | |
847 | ||
0590b933 AV |
848 | static u64 prio_low = ~0ULL/2; |
849 | static u64 prio_high = ~0ULL/2 - 1; | |
850 | ||
f368c07d | 851 | /* Add rule to given filterlist if not a duplicate. */ |
36c4f1b1 | 852 | static inline int audit_add_rule(struct audit_entry *entry) |
fe7752ba | 853 | { |
93315ed6 | 854 | struct audit_entry *e; |
f368c07d | 855 | struct audit_watch *watch = entry->rule.watch; |
74c3cbe3 | 856 | struct audit_tree *tree = entry->rule.tree; |
36c4f1b1 | 857 | struct list_head *list; |
ae7b8f41 | 858 | int err; |
471a5c7c AV |
859 | #ifdef CONFIG_AUDITSYSCALL |
860 | int dont_count = 0; | |
861 | ||
862 | /* If either of these, don't count towards total */ | |
863 | if (entry->rule.listnr == AUDIT_FILTER_USER || | |
864 | entry->rule.listnr == AUDIT_FILTER_TYPE) | |
865 | dont_count = 1; | |
866 | #endif | |
f368c07d | 867 | |
f368c07d | 868 | mutex_lock(&audit_filter_mutex); |
36c4f1b1 | 869 | e = audit_find_rule(entry, &list); |
f368c07d | 870 | if (e) { |
35fe4d0b | 871 | mutex_unlock(&audit_filter_mutex); |
f368c07d | 872 | err = -EEXIST; |
74c3cbe3 AV |
873 | /* normally audit_add_tree_rule() will free it on failure */ |
874 | if (tree) | |
875 | audit_put_tree(tree); | |
f368c07d AG |
876 | goto error; |
877 | } | |
fe7752ba | 878 | |
f368c07d AG |
879 | if (watch) { |
880 | /* audit_filter_mutex is dropped and re-taken during this call */ | |
ae7b8f41 | 881 | err = audit_add_watch(&entry->rule, &list); |
f368c07d AG |
882 | if (err) { |
883 | mutex_unlock(&audit_filter_mutex); | |
2f992ee8 CG |
884 | /* |
885 | * normally audit_add_tree_rule() will free it | |
886 | * on failure | |
887 | */ | |
888 | if (tree) | |
889 | audit_put_tree(tree); | |
f368c07d AG |
890 | goto error; |
891 | } | |
fe7752ba | 892 | } |
74c3cbe3 AV |
893 | if (tree) { |
894 | err = audit_add_tree_rule(&entry->rule); | |
895 | if (err) { | |
896 | mutex_unlock(&audit_filter_mutex); | |
897 | goto error; | |
898 | } | |
899 | } | |
fe7752ba | 900 | |
0590b933 AV |
901 | entry->rule.prio = ~0ULL; |
902 | if (entry->rule.listnr == AUDIT_FILTER_EXIT) { | |
903 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) | |
904 | entry->rule.prio = ++prio_high; | |
905 | else | |
906 | entry->rule.prio = --prio_low; | |
907 | } | |
908 | ||
fe7752ba | 909 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
e45aa212 AV |
910 | list_add(&entry->rule.list, |
911 | &audit_rules_list[entry->rule.listnr]); | |
fe7752ba | 912 | list_add_rcu(&entry->list, list); |
6a2bceec | 913 | entry->rule.flags &= ~AUDIT_FILTER_PREPEND; |
fe7752ba | 914 | } else { |
e45aa212 AV |
915 | list_add_tail(&entry->rule.list, |
916 | &audit_rules_list[entry->rule.listnr]); | |
fe7752ba DW |
917 | list_add_tail_rcu(&entry->list, list); |
918 | } | |
471a5c7c AV |
919 | #ifdef CONFIG_AUDITSYSCALL |
920 | if (!dont_count) | |
921 | audit_n_rules++; | |
e54dc243 AG |
922 | |
923 | if (!audit_match_signal(entry)) | |
924 | audit_signals++; | |
471a5c7c | 925 | #endif |
f368c07d | 926 | mutex_unlock(&audit_filter_mutex); |
fe7752ba | 927 | |
f368c07d AG |
928 | return 0; |
929 | ||
930 | error: | |
f368c07d AG |
931 | if (watch) |
932 | audit_put_watch(watch); /* tmp watch, matches initial get */ | |
933 | return err; | |
fe7752ba DW |
934 | } |
935 | ||
f368c07d | 936 | /* Remove an existing rule from filterlist. */ |
36c4f1b1 | 937 | static inline int audit_del_rule(struct audit_entry *entry) |
fe7752ba DW |
938 | { |
939 | struct audit_entry *e; | |
cfcad62c | 940 | struct audit_watch *watch = entry->rule.watch; |
74c3cbe3 | 941 | struct audit_tree *tree = entry->rule.tree; |
36c4f1b1 | 942 | struct list_head *list; |
36c4f1b1 | 943 | int ret = 0; |
471a5c7c AV |
944 | #ifdef CONFIG_AUDITSYSCALL |
945 | int dont_count = 0; | |
946 | ||
947 | /* If either of these, don't count towards total */ | |
948 | if (entry->rule.listnr == AUDIT_FILTER_USER || | |
949 | entry->rule.listnr == AUDIT_FILTER_TYPE) | |
950 | dont_count = 1; | |
951 | #endif | |
f368c07d | 952 | |
f368c07d | 953 | mutex_lock(&audit_filter_mutex); |
36c4f1b1 | 954 | e = audit_find_rule(entry, &list); |
f368c07d AG |
955 | if (!e) { |
956 | mutex_unlock(&audit_filter_mutex); | |
957 | ret = -ENOENT; | |
958 | goto out; | |
959 | } | |
960 | ||
cfcad62c | 961 | if (e->rule.watch) |
a05fb6cc | 962 | audit_remove_watch_rule(&e->rule); |
f368c07d | 963 | |
74c3cbe3 AV |
964 | if (e->rule.tree) |
965 | audit_remove_tree_rule(&e->rule); | |
966 | ||
f368c07d | 967 | list_del_rcu(&e->list); |
e45aa212 | 968 | list_del(&e->rule.list); |
f368c07d AG |
969 | call_rcu(&e->rcu, audit_free_rule_rcu); |
970 | ||
471a5c7c AV |
971 | #ifdef CONFIG_AUDITSYSCALL |
972 | if (!dont_count) | |
973 | audit_n_rules--; | |
e54dc243 AG |
974 | |
975 | if (!audit_match_signal(entry)) | |
976 | audit_signals--; | |
471a5c7c | 977 | #endif |
f368c07d AG |
978 | mutex_unlock(&audit_filter_mutex); |
979 | ||
f368c07d | 980 | out: |
cfcad62c EP |
981 | if (watch) |
982 | audit_put_watch(watch); /* match initial get */ | |
74c3cbe3 AV |
983 | if (tree) |
984 | audit_put_tree(tree); /* that's the temporary one */ | |
f368c07d AG |
985 | |
986 | return ret; | |
fe7752ba DW |
987 | } |
988 | ||
93315ed6 | 989 | /* List rules using struct audit_rule_data. */ |
f9441639 | 990 | static void audit_list_rules(__u32 portid, int seq, struct sk_buff_head *q) |
93315ed6 | 991 | { |
9044e6bc | 992 | struct sk_buff *skb; |
e45aa212 | 993 | struct audit_krule *r; |
93315ed6 AG |
994 | int i; |
995 | ||
f368c07d AG |
996 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
997 | * iterator to sync with list writers. */ | |
93315ed6 | 998 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
e45aa212 | 999 | list_for_each_entry(r, &audit_rules_list[i], list) { |
f368c07d AG |
1000 | struct audit_rule_data *data; |
1001 | ||
e45aa212 | 1002 | data = audit_krule_to_data(r); |
f368c07d AG |
1003 | if (unlikely(!data)) |
1004 | break; | |
f9441639 RGB |
1005 | skb = audit_make_reply(portid, seq, AUDIT_LIST_RULES, |
1006 | 0, 1, data, | |
1007 | sizeof(*data) + data->buflen); | |
9044e6bc AV |
1008 | if (skb) |
1009 | skb_queue_tail(q, skb); | |
93315ed6 AG |
1010 | kfree(data); |
1011 | } | |
1012 | } | |
f9441639 | 1013 | skb = audit_make_reply(portid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
9044e6bc AV |
1014 | if (skb) |
1015 | skb_queue_tail(q, skb); | |
93315ed6 AG |
1016 | } |
1017 | ||
5adc8a6a | 1018 | /* Log rule additions and removals */ |
dc9eb698 | 1019 | static void audit_log_rule_change(char *action, struct audit_krule *rule, int res) |
5adc8a6a AG |
1020 | { |
1021 | struct audit_buffer *ab; | |
dc9eb698 | 1022 | uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(current)); |
4440e854 | 1023 | unsigned int sessionid = audit_get_sessionid(current); |
5adc8a6a | 1024 | |
1a6b9f23 EP |
1025 | if (!audit_enabled) |
1026 | return; | |
1027 | ||
5adc8a6a AG |
1028 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
1029 | if (!ab) | |
1030 | return; | |
dc9eb698 | 1031 | audit_log_format(ab, "auid=%u ses=%u" ,loginuid, sessionid); |
b122c376 | 1032 | audit_log_task_context(ab); |
9d960985 EP |
1033 | audit_log_format(ab, " op="); |
1034 | audit_log_string(ab, action); | |
1035 | audit_log_key(ab, rule->filterkey); | |
5adc8a6a AG |
1036 | audit_log_format(ab, " list=%d res=%d", rule->listnr, res); |
1037 | audit_log_end(ab); | |
1038 | } | |
1039 | ||
fe7752ba | 1040 | /** |
ce0d9f04 | 1041 | * audit_rule_change - apply all rules to the specified message type |
fe7752ba | 1042 | * @type: audit message type |
f9441639 | 1043 | * @portid: target port id for netlink audit messages |
fe7752ba DW |
1044 | * @seq: netlink audit message sequence (serial) number |
1045 | * @data: payload data | |
93315ed6 | 1046 | * @datasz: size of payload data |
fe7752ba | 1047 | */ |
ce0d9f04 RGB |
1048 | int audit_rule_change(int type, __u32 portid, int seq, void *data, |
1049 | size_t datasz) | |
fe7752ba | 1050 | { |
93315ed6 AG |
1051 | int err = 0; |
1052 | struct audit_entry *entry; | |
fe7752ba | 1053 | |
e85322d2 RGB |
1054 | entry = audit_data_to_entry(data, datasz); |
1055 | if (IS_ERR(entry)) | |
1056 | return PTR_ERR(entry); | |
1057 | ||
fe7752ba | 1058 | switch (type) { |
93315ed6 | 1059 | case AUDIT_ADD_RULE: |
36c4f1b1 | 1060 | err = audit_add_rule(entry); |
e7df61f4 | 1061 | audit_log_rule_change("add_rule", &entry->rule, !err); |
fe7752ba | 1062 | break; |
93315ed6 | 1063 | case AUDIT_DEL_RULE: |
36c4f1b1 | 1064 | err = audit_del_rule(entry); |
e7df61f4 | 1065 | audit_log_rule_change("remove_rule", &entry->rule, !err); |
fe7752ba DW |
1066 | break; |
1067 | default: | |
739c9503 EP |
1068 | err = -EINVAL; |
1069 | WARN_ON(1); | |
fe7752ba DW |
1070 | } |
1071 | ||
e85322d2 RGB |
1072 | if (err || type == AUDIT_DEL_RULE) |
1073 | audit_free_rule(entry); | |
1074 | ||
fe7752ba DW |
1075 | return err; |
1076 | } | |
1077 | ||
ce0d9f04 RGB |
1078 | /** |
1079 | * audit_list_rules_send - list the audit rules | |
d211f177 | 1080 | * @request_skb: skb of request we are replying to (used to target the reply) |
ce0d9f04 RGB |
1081 | * @seq: netlink audit message sequence (serial) number |
1082 | */ | |
6f285b19 | 1083 | int audit_list_rules_send(struct sk_buff *request_skb, int seq) |
ce0d9f04 | 1084 | { |
6f285b19 EB |
1085 | u32 portid = NETLINK_CB(request_skb).portid; |
1086 | struct net *net = sock_net(NETLINK_CB(request_skb).sk); | |
ce0d9f04 RGB |
1087 | struct task_struct *tsk; |
1088 | struct audit_netlink_list *dest; | |
1089 | int err = 0; | |
1090 | ||
1091 | /* We can't just spew out the rules here because we might fill | |
1092 | * the available socket buffer space and deadlock waiting for | |
1093 | * auditctl to read from it... which isn't ever going to | |
1094 | * happen if we're actually running in the context of auditctl | |
1095 | * trying to _send_ the stuff */ | |
1096 | ||
1097 | dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); | |
1098 | if (!dest) | |
1099 | return -ENOMEM; | |
6f285b19 | 1100 | dest->net = get_net(net); |
ce0d9f04 | 1101 | dest->portid = portid; |
ce0d9f04 RGB |
1102 | skb_queue_head_init(&dest->q); |
1103 | ||
1104 | mutex_lock(&audit_filter_mutex); | |
1105 | audit_list_rules(portid, seq, &dest->q); | |
1106 | mutex_unlock(&audit_filter_mutex); | |
1107 | ||
1108 | tsk = kthread_run(audit_send_list, dest, "audit_send_list"); | |
1109 | if (IS_ERR(tsk)) { | |
1110 | skb_queue_purge(&dest->q); | |
1111 | kfree(dest); | |
1112 | err = PTR_ERR(tsk); | |
1113 | } | |
1114 | ||
1115 | return err; | |
1116 | } | |
1117 | ||
5af75d8d | 1118 | int audit_comparator(u32 left, u32 op, u32 right) |
fe7752ba DW |
1119 | { |
1120 | switch (op) { | |
5af75d8d | 1121 | case Audit_equal: |
fe7752ba | 1122 | return (left == right); |
5af75d8d | 1123 | case Audit_not_equal: |
fe7752ba | 1124 | return (left != right); |
5af75d8d | 1125 | case Audit_lt: |
fe7752ba | 1126 | return (left < right); |
5af75d8d | 1127 | case Audit_le: |
fe7752ba | 1128 | return (left <= right); |
5af75d8d | 1129 | case Audit_gt: |
fe7752ba | 1130 | return (left > right); |
5af75d8d | 1131 | case Audit_ge: |
fe7752ba | 1132 | return (left >= right); |
5af75d8d | 1133 | case Audit_bitmask: |
74f2345b | 1134 | return (left & right); |
5af75d8d | 1135 | case Audit_bittest: |
74f2345b | 1136 | return ((left & right) == right); |
5af75d8d AV |
1137 | default: |
1138 | BUG(); | |
1139 | return 0; | |
fe7752ba DW |
1140 | } |
1141 | } | |
1142 | ||
ca57ec0f EB |
1143 | int audit_uid_comparator(kuid_t left, u32 op, kuid_t right) |
1144 | { | |
1145 | switch (op) { | |
1146 | case Audit_equal: | |
1147 | return uid_eq(left, right); | |
1148 | case Audit_not_equal: | |
1149 | return !uid_eq(left, right); | |
1150 | case Audit_lt: | |
1151 | return uid_lt(left, right); | |
1152 | case Audit_le: | |
1153 | return uid_lte(left, right); | |
1154 | case Audit_gt: | |
1155 | return uid_gt(left, right); | |
1156 | case Audit_ge: | |
1157 | return uid_gte(left, right); | |
1158 | case Audit_bitmask: | |
1159 | case Audit_bittest: | |
1160 | default: | |
1161 | BUG(); | |
1162 | return 0; | |
1163 | } | |
1164 | } | |
1165 | ||
1166 | int audit_gid_comparator(kgid_t left, u32 op, kgid_t right) | |
1167 | { | |
1168 | switch (op) { | |
1169 | case Audit_equal: | |
1170 | return gid_eq(left, right); | |
1171 | case Audit_not_equal: | |
1172 | return !gid_eq(left, right); | |
1173 | case Audit_lt: | |
1174 | return gid_lt(left, right); | |
1175 | case Audit_le: | |
1176 | return gid_lte(left, right); | |
1177 | case Audit_gt: | |
1178 | return gid_gt(left, right); | |
1179 | case Audit_ge: | |
1180 | return gid_gte(left, right); | |
1181 | case Audit_bitmask: | |
1182 | case Audit_bittest: | |
1183 | default: | |
1184 | BUG(); | |
1185 | return 0; | |
1186 | } | |
1187 | } | |
1188 | ||
bfcec708 JL |
1189 | /** |
1190 | * parent_len - find the length of the parent portion of a pathname | |
1191 | * @path: pathname of which to determine length | |
1192 | */ | |
1193 | int parent_len(const char *path) | |
1194 | { | |
1195 | int plen; | |
1196 | const char *p; | |
1197 | ||
1198 | plen = strlen(path); | |
1199 | ||
1200 | if (plen == 0) | |
1201 | return plen; | |
1202 | ||
1203 | /* disregard trailing slashes */ | |
1204 | p = path + plen - 1; | |
1205 | while ((*p == '/') && (p > path)) | |
1206 | p--; | |
1207 | ||
1208 | /* walk backward until we find the next slash or hit beginning */ | |
1209 | while ((*p != '/') && (p > path)) | |
1210 | p--; | |
1211 | ||
1212 | /* did we find a slash? Then increment to include it in path */ | |
1213 | if (*p == '/') | |
1214 | p++; | |
1215 | ||
1216 | return p - path; | |
1217 | } | |
1218 | ||
e3d6b07b JL |
1219 | /** |
1220 | * audit_compare_dname_path - compare given dentry name with last component in | |
1221 | * given path. Return of 0 indicates a match. | |
1222 | * @dname: dentry name that we're comparing | |
1223 | * @path: full pathname that we're comparing | |
1224 | * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL | |
1225 | * here indicates that we must compute this value. | |
1226 | */ | |
1227 | int audit_compare_dname_path(const char *dname, const char *path, int parentlen) | |
f368c07d | 1228 | { |
e3d6b07b | 1229 | int dlen, pathlen; |
f368c07d AG |
1230 | const char *p; |
1231 | ||
f368c07d | 1232 | dlen = strlen(dname); |
29e9a346 EP |
1233 | pathlen = strlen(path); |
1234 | if (pathlen < dlen) | |
f368c07d AG |
1235 | return 1; |
1236 | ||
e3d6b07b | 1237 | parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen; |
29e9a346 | 1238 | if (pathlen - parentlen != dlen) |
f368c07d | 1239 | return 1; |
29e9a346 EP |
1240 | |
1241 | p = path + parentlen; | |
fe7752ba | 1242 | |
f368c07d AG |
1243 | return strncmp(p, dname, dlen); |
1244 | } | |
fe7752ba | 1245 | |
62062cf8 | 1246 | static int audit_filter_user_rules(struct audit_krule *rule, int type, |
fe7752ba DW |
1247 | enum audit_state *state) |
1248 | { | |
1249 | int i; | |
1250 | ||
1251 | for (i = 0; i < rule->field_count; i++) { | |
93315ed6 | 1252 | struct audit_field *f = &rule->fields[i]; |
f1dc4867 | 1253 | pid_t pid; |
fe7752ba | 1254 | int result = 0; |
c53fa1ed | 1255 | u32 sid; |
fe7752ba | 1256 | |
93315ed6 | 1257 | switch (f->type) { |
fe7752ba | 1258 | case AUDIT_PID: |
f1dc4867 RGB |
1259 | pid = task_pid_nr(current); |
1260 | result = audit_comparator(pid, f->op, f->val); | |
fe7752ba DW |
1261 | break; |
1262 | case AUDIT_UID: | |
ca57ec0f | 1263 | result = audit_uid_comparator(current_uid(), f->op, f->uid); |
fe7752ba DW |
1264 | break; |
1265 | case AUDIT_GID: | |
ca57ec0f | 1266 | result = audit_gid_comparator(current_gid(), f->op, f->gid); |
fe7752ba DW |
1267 | break; |
1268 | case AUDIT_LOGINUID: | |
ca57ec0f EB |
1269 | result = audit_uid_comparator(audit_get_loginuid(current), |
1270 | f->op, f->uid); | |
fe7752ba | 1271 | break; |
780a7654 EB |
1272 | case AUDIT_LOGINUID_SET: |
1273 | result = audit_comparator(audit_loginuid_set(current), | |
1274 | f->op, f->val); | |
1275 | break; | |
62062cf8 EP |
1276 | case AUDIT_MSGTYPE: |
1277 | result = audit_comparator(type, f->op, f->val); | |
1278 | break; | |
d29be158 MT |
1279 | case AUDIT_SUBJ_USER: |
1280 | case AUDIT_SUBJ_ROLE: | |
1281 | case AUDIT_SUBJ_TYPE: | |
1282 | case AUDIT_SUBJ_SEN: | |
1283 | case AUDIT_SUBJ_CLR: | |
c53fa1ed PM |
1284 | if (f->lsm_rule) { |
1285 | security_task_getsecid(current, &sid); | |
1286 | result = security_audit_rule_match(sid, | |
d29be158 MT |
1287 | f->type, |
1288 | f->op, | |
1289 | f->lsm_rule, | |
1290 | NULL); | |
c53fa1ed | 1291 | } |
d29be158 | 1292 | break; |
fe7752ba DW |
1293 | } |
1294 | ||
1295 | if (!result) | |
1296 | return 0; | |
1297 | } | |
1298 | switch (rule->action) { | |
1299 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; | |
fe7752ba DW |
1300 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; |
1301 | } | |
1302 | return 1; | |
1303 | } | |
1304 | ||
62062cf8 | 1305 | int audit_filter_user(int type) |
fe7752ba | 1306 | { |
11f57ced | 1307 | enum audit_state state = AUDIT_DISABLED; |
fe7752ba | 1308 | struct audit_entry *e; |
724e4fcc RGB |
1309 | int rc, ret; |
1310 | ||
1311 | ret = 1; /* Audit by default */ | |
fe7752ba DW |
1312 | |
1313 | rcu_read_lock(); | |
1314 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { | |
724e4fcc RGB |
1315 | rc = audit_filter_user_rules(&e->rule, type, &state); |
1316 | if (rc) { | |
1317 | if (rc > 0 && state == AUDIT_DISABLED) | |
fe7752ba DW |
1318 | ret = 0; |
1319 | break; | |
1320 | } | |
1321 | } | |
1322 | rcu_read_unlock(); | |
1323 | ||
724e4fcc | 1324 | return ret; |
fe7752ba DW |
1325 | } |
1326 | ||
1327 | int audit_filter_type(int type) | |
1328 | { | |
1329 | struct audit_entry *e; | |
1330 | int result = 0; | |
9ce34218 | 1331 | |
fe7752ba DW |
1332 | rcu_read_lock(); |
1333 | if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE])) | |
1334 | goto unlock_and_return; | |
1335 | ||
1336 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], | |
1337 | list) { | |
fe7752ba | 1338 | int i; |
93315ed6 AG |
1339 | for (i = 0; i < e->rule.field_count; i++) { |
1340 | struct audit_field *f = &e->rule.fields[i]; | |
1341 | if (f->type == AUDIT_MSGTYPE) { | |
1342 | result = audit_comparator(type, f->op, f->val); | |
fe7752ba DW |
1343 | if (!result) |
1344 | break; | |
1345 | } | |
1346 | } | |
1347 | if (result) | |
1348 | goto unlock_and_return; | |
1349 | } | |
1350 | unlock_and_return: | |
1351 | rcu_read_unlock(); | |
1352 | return result; | |
1353 | } | |
3dc7e315 | 1354 | |
e45aa212 | 1355 | static int update_lsm_rule(struct audit_krule *r) |
1a9d0797 | 1356 | { |
e45aa212 | 1357 | struct audit_entry *entry = container_of(r, struct audit_entry, rule); |
1a9d0797 | 1358 | struct audit_entry *nentry; |
1a9d0797 AV |
1359 | int err = 0; |
1360 | ||
e45aa212 | 1361 | if (!security_audit_rule_known(r)) |
1a9d0797 AV |
1362 | return 0; |
1363 | ||
ae7b8f41 | 1364 | nentry = audit_dupe_rule(r); |
1a9d0797 AV |
1365 | if (IS_ERR(nentry)) { |
1366 | /* save the first error encountered for the | |
1367 | * return value */ | |
1368 | err = PTR_ERR(nentry); | |
1369 | audit_panic("error updating LSM filters"); | |
ae7b8f41 | 1370 | if (r->watch) |
e45aa212 | 1371 | list_del(&r->rlist); |
1a9d0797 | 1372 | list_del_rcu(&entry->list); |
e45aa212 | 1373 | list_del(&r->list); |
1a9d0797 | 1374 | } else { |
ae7b8f41 | 1375 | if (r->watch || r->tree) |
e45aa212 | 1376 | list_replace_init(&r->rlist, &nentry->rule.rlist); |
1a9d0797 | 1377 | list_replace_rcu(&entry->list, &nentry->list); |
e45aa212 | 1378 | list_replace(&r->list, &nentry->rule.list); |
1a9d0797 AV |
1379 | } |
1380 | call_rcu(&entry->rcu, audit_free_rule_rcu); | |
1381 | ||
1382 | return err; | |
1383 | } | |
1384 | ||
04305e4a | 1385 | /* This function will re-initialize the lsm_rule field of all applicable rules. |
d7a96f3a | 1386 | * It will traverse the filter lists serarching for rules that contain LSM |
3dc7e315 | 1387 | * specific filter fields. When such a rule is found, it is copied, the |
d7a96f3a | 1388 | * LSM field is re-initialized, and the old rule is replaced with the |
3dc7e315 | 1389 | * updated rule. */ |
d7a96f3a | 1390 | int audit_update_lsm_rules(void) |
3dc7e315 | 1391 | { |
e45aa212 | 1392 | struct audit_krule *r, *n; |
3dc7e315 DG |
1393 | int i, err = 0; |
1394 | ||
f368c07d AG |
1395 | /* audit_filter_mutex synchronizes the writers */ |
1396 | mutex_lock(&audit_filter_mutex); | |
3dc7e315 DG |
1397 | |
1398 | for (i = 0; i < AUDIT_NR_FILTERS; i++) { | |
e45aa212 AV |
1399 | list_for_each_entry_safe(r, n, &audit_rules_list[i], list) { |
1400 | int res = update_lsm_rule(r); | |
1a9d0797 AV |
1401 | if (!err) |
1402 | err = res; | |
3dc7e315 DG |
1403 | } |
1404 | } | |
f368c07d | 1405 | mutex_unlock(&audit_filter_mutex); |
3dc7e315 DG |
1406 | |
1407 | return err; | |
1408 | } |