Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/kernel/auditsc.c
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Wed Mar 4 10:48:58 2009 UTC (15 years, 6 months ago) by niro
Original Path: alx-src/trunk/kernel26-alx/linux/kernel/auditsc.c
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Wed Mar 4 10:48:58 2009 UTC (15 years, 6 months ago) by niro
Original Path: alx-src/trunk/kernel26-alx/linux/kernel/auditsc.c
File MIME type: text/plain
File size: 29252 byte(s)
import linux sources based on 2.6.12-alx-r9: -using linux-2.6.12.6 -using 2.6.12-ck6 patch set -using fbsplash-0.9.2-r3 -using vesafb-tng-0.9-rc7 -using squashfs-2.2 -added cddvd-cmdfilter-drop.patch as ck dropped it -added via-epia-dri (cle266) patch -added zd1211-svn-32 wlan driver (http://zd1211.ath.cx/download/) -added debian patches to zd1211 for wep256 etc
1 | /* auditsc.c -- System-call auditing support |
2 | * Handles all system-call specific auditing features. |
3 | * |
4 | * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina. |
5 | * All Rights Reserved. |
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 | * Written by Rickard E. (Rik) Faith <faith@redhat.com> |
22 | * |
23 | * Many of the ideas implemented here are from Stephen C. Tweedie, |
24 | * especially the idea of avoiding a copy by using getname. |
25 | * |
26 | * The method for actual interception of syscall entry and exit (not in |
27 | * this file -- see entry.S) is based on a GPL'd patch written by |
28 | * okir@suse.de and Copyright 2003 SuSE Linux AG. |
29 | * |
30 | */ |
31 | |
32 | #include <linux/init.h> |
33 | #include <asm/atomic.h> |
34 | #include <asm/types.h> |
35 | #include <linux/mm.h> |
36 | #include <linux/module.h> |
37 | |
38 | #include <linux/audit.h> |
39 | #include <linux/personality.h> |
40 | #include <linux/time.h> |
41 | #include <asm/unistd.h> |
42 | |
43 | /* 0 = no checking |
44 | 1 = put_count checking |
45 | 2 = verbose put_count checking |
46 | */ |
47 | #define AUDIT_DEBUG 0 |
48 | |
49 | /* No syscall auditing will take place unless audit_enabled != 0. */ |
50 | extern int audit_enabled; |
51 | |
52 | /* AUDIT_NAMES is the number of slots we reserve in the audit_context |
53 | * for saving names from getname(). */ |
54 | #define AUDIT_NAMES 20 |
55 | |
56 | /* AUDIT_NAMES_RESERVED is the number of slots we reserve in the |
57 | * audit_context from being used for nameless inodes from |
58 | * path_lookup. */ |
59 | #define AUDIT_NAMES_RESERVED 7 |
60 | |
61 | /* At task start time, the audit_state is set in the audit_context using |
62 | a per-task filter. At syscall entry, the audit_state is augmented by |
63 | the syscall filter. */ |
64 | enum audit_state { |
65 | AUDIT_DISABLED, /* Do not create per-task audit_context. |
66 | * No syscall-specific audit records can |
67 | * be generated. */ |
68 | AUDIT_SETUP_CONTEXT, /* Create the per-task audit_context, |
69 | * but don't necessarily fill it in at |
70 | * syscall entry time (i.e., filter |
71 | * instead). */ |
72 | AUDIT_BUILD_CONTEXT, /* Create the per-task audit_context, |
73 | * and always fill it in at syscall |
74 | * entry time. This makes a full |
75 | * syscall record available if some |
76 | * other part of the kernel decides it |
77 | * should be recorded. */ |
78 | AUDIT_RECORD_CONTEXT /* Create the per-task audit_context, |
79 | * always fill it in at syscall entry |
80 | * time, and always write out the audit |
81 | * record at syscall exit time. */ |
82 | }; |
83 | |
84 | /* When fs/namei.c:getname() is called, we store the pointer in name and |
85 | * we don't let putname() free it (instead we free all of the saved |
86 | * pointers at syscall exit time). |
87 | * |
88 | * Further, in fs/namei.c:path_lookup() we store the inode and device. */ |
89 | struct audit_names { |
90 | const char *name; |
91 | unsigned long ino; |
92 | dev_t dev; |
93 | umode_t mode; |
94 | uid_t uid; |
95 | gid_t gid; |
96 | dev_t rdev; |
97 | }; |
98 | |
99 | struct audit_aux_data { |
100 | struct audit_aux_data *next; |
101 | int type; |
102 | }; |
103 | |
104 | #define AUDIT_AUX_IPCPERM 0 |
105 | |
106 | struct audit_aux_data_ipcctl { |
107 | struct audit_aux_data d; |
108 | struct ipc_perm p; |
109 | unsigned long qbytes; |
110 | uid_t uid; |
111 | gid_t gid; |
112 | mode_t mode; |
113 | }; |
114 | |
115 | |
116 | /* The per-task audit context. */ |
117 | struct audit_context { |
118 | int in_syscall; /* 1 if task is in a syscall */ |
119 | enum audit_state state; |
120 | unsigned int serial; /* serial number for record */ |
121 | struct timespec ctime; /* time of syscall entry */ |
122 | uid_t loginuid; /* login uid (identity) */ |
123 | int major; /* syscall number */ |
124 | unsigned long argv[4]; /* syscall arguments */ |
125 | int return_valid; /* return code is valid */ |
126 | long return_code;/* syscall return code */ |
127 | int auditable; /* 1 if record should be written */ |
128 | int name_count; |
129 | struct audit_names names[AUDIT_NAMES]; |
130 | struct audit_context *previous; /* For nested syscalls */ |
131 | struct audit_aux_data *aux; |
132 | |
133 | /* Save things to print about task_struct */ |
134 | pid_t pid; |
135 | uid_t uid, euid, suid, fsuid; |
136 | gid_t gid, egid, sgid, fsgid; |
137 | unsigned long personality; |
138 | int arch; |
139 | |
140 | #if AUDIT_DEBUG |
141 | int put_count; |
142 | int ino_count; |
143 | #endif |
144 | }; |
145 | |
146 | /* Public API */ |
147 | /* There are three lists of rules -- one to search at task creation |
148 | * time, one to search at syscall entry time, and another to search at |
149 | * syscall exit time. */ |
150 | static LIST_HEAD(audit_tsklist); |
151 | static LIST_HEAD(audit_entlist); |
152 | static LIST_HEAD(audit_extlist); |
153 | |
154 | struct audit_entry { |
155 | struct list_head list; |
156 | struct rcu_head rcu; |
157 | struct audit_rule rule; |
158 | }; |
159 | |
160 | /* Check to see if two rules are identical. It is called from |
161 | * audit_del_rule during AUDIT_DEL. */ |
162 | static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b) |
163 | { |
164 | int i; |
165 | |
166 | if (a->flags != b->flags) |
167 | return 1; |
168 | |
169 | if (a->action != b->action) |
170 | return 1; |
171 | |
172 | if (a->field_count != b->field_count) |
173 | return 1; |
174 | |
175 | for (i = 0; i < a->field_count; i++) { |
176 | if (a->fields[i] != b->fields[i] |
177 | || a->values[i] != b->values[i]) |
178 | return 1; |
179 | } |
180 | |
181 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
182 | if (a->mask[i] != b->mask[i]) |
183 | return 1; |
184 | |
185 | return 0; |
186 | } |
187 | |
188 | /* Note that audit_add_rule and audit_del_rule are called via |
189 | * audit_receive() in audit.c, and are protected by |
190 | * audit_netlink_sem. */ |
191 | static inline int audit_add_rule(struct audit_entry *entry, |
192 | struct list_head *list) |
193 | { |
194 | if (entry->rule.flags & AUDIT_PREPEND) { |
195 | entry->rule.flags &= ~AUDIT_PREPEND; |
196 | list_add_rcu(&entry->list, list); |
197 | } else { |
198 | list_add_tail_rcu(&entry->list, list); |
199 | } |
200 | return 0; |
201 | } |
202 | |
203 | static void audit_free_rule(struct rcu_head *head) |
204 | { |
205 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); |
206 | kfree(e); |
207 | } |
208 | |
209 | /* Note that audit_add_rule and audit_del_rule are called via |
210 | * audit_receive() in audit.c, and are protected by |
211 | * audit_netlink_sem. */ |
212 | static inline int audit_del_rule(struct audit_rule *rule, |
213 | struct list_head *list) |
214 | { |
215 | struct audit_entry *e; |
216 | |
217 | /* Do not use the _rcu iterator here, since this is the only |
218 | * deletion routine. */ |
219 | list_for_each_entry(e, list, list) { |
220 | if (!audit_compare_rule(rule, &e->rule)) { |
221 | list_del_rcu(&e->list); |
222 | call_rcu(&e->rcu, audit_free_rule); |
223 | return 0; |
224 | } |
225 | } |
226 | return -EFAULT; /* No matching rule */ |
227 | } |
228 | |
229 | #ifdef CONFIG_NET |
230 | /* Copy rule from user-space to kernel-space. Called during |
231 | * AUDIT_ADD. */ |
232 | static int audit_copy_rule(struct audit_rule *d, struct audit_rule *s) |
233 | { |
234 | int i; |
235 | |
236 | if (s->action != AUDIT_NEVER |
237 | && s->action != AUDIT_POSSIBLE |
238 | && s->action != AUDIT_ALWAYS) |
239 | return -1; |
240 | if (s->field_count < 0 || s->field_count > AUDIT_MAX_FIELDS) |
241 | return -1; |
242 | |
243 | d->flags = s->flags; |
244 | d->action = s->action; |
245 | d->field_count = s->field_count; |
246 | for (i = 0; i < d->field_count; i++) { |
247 | d->fields[i] = s->fields[i]; |
248 | d->values[i] = s->values[i]; |
249 | } |
250 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) d->mask[i] = s->mask[i]; |
251 | return 0; |
252 | } |
253 | |
254 | int audit_receive_filter(int type, int pid, int uid, int seq, void *data, |
255 | uid_t loginuid) |
256 | { |
257 | u32 flags; |
258 | struct audit_entry *entry; |
259 | int err = 0; |
260 | |
261 | switch (type) { |
262 | case AUDIT_LIST: |
263 | /* The *_rcu iterators not needed here because we are |
264 | always called with audit_netlink_sem held. */ |
265 | list_for_each_entry(entry, &audit_tsklist, list) |
266 | audit_send_reply(pid, seq, AUDIT_LIST, 0, 1, |
267 | &entry->rule, sizeof(entry->rule)); |
268 | list_for_each_entry(entry, &audit_entlist, list) |
269 | audit_send_reply(pid, seq, AUDIT_LIST, 0, 1, |
270 | &entry->rule, sizeof(entry->rule)); |
271 | list_for_each_entry(entry, &audit_extlist, list) |
272 | audit_send_reply(pid, seq, AUDIT_LIST, 0, 1, |
273 | &entry->rule, sizeof(entry->rule)); |
274 | audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); |
275 | break; |
276 | case AUDIT_ADD: |
277 | if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL))) |
278 | return -ENOMEM; |
279 | if (audit_copy_rule(&entry->rule, data)) { |
280 | kfree(entry); |
281 | return -EINVAL; |
282 | } |
283 | flags = entry->rule.flags; |
284 | if (!err && (flags & AUDIT_PER_TASK)) |
285 | err = audit_add_rule(entry, &audit_tsklist); |
286 | if (!err && (flags & AUDIT_AT_ENTRY)) |
287 | err = audit_add_rule(entry, &audit_entlist); |
288 | if (!err && (flags & AUDIT_AT_EXIT)) |
289 | err = audit_add_rule(entry, &audit_extlist); |
290 | audit_log(NULL, "auid %u added an audit rule\n", loginuid); |
291 | break; |
292 | case AUDIT_DEL: |
293 | flags =((struct audit_rule *)data)->flags; |
294 | if (!err && (flags & AUDIT_PER_TASK)) |
295 | err = audit_del_rule(data, &audit_tsklist); |
296 | if (!err && (flags & AUDIT_AT_ENTRY)) |
297 | err = audit_del_rule(data, &audit_entlist); |
298 | if (!err && (flags & AUDIT_AT_EXIT)) |
299 | err = audit_del_rule(data, &audit_extlist); |
300 | audit_log(NULL, "auid %u removed an audit rule\n", loginuid); |
301 | break; |
302 | default: |
303 | return -EINVAL; |
304 | } |
305 | |
306 | return err; |
307 | } |
308 | #endif |
309 | |
310 | /* Compare a task_struct with an audit_rule. Return 1 on match, 0 |
311 | * otherwise. */ |
312 | static int audit_filter_rules(struct task_struct *tsk, |
313 | struct audit_rule *rule, |
314 | struct audit_context *ctx, |
315 | enum audit_state *state) |
316 | { |
317 | int i, j; |
318 | |
319 | for (i = 0; i < rule->field_count; i++) { |
320 | u32 field = rule->fields[i] & ~AUDIT_NEGATE; |
321 | u32 value = rule->values[i]; |
322 | int result = 0; |
323 | |
324 | switch (field) { |
325 | case AUDIT_PID: |
326 | result = (tsk->pid == value); |
327 | break; |
328 | case AUDIT_UID: |
329 | result = (tsk->uid == value); |
330 | break; |
331 | case AUDIT_EUID: |
332 | result = (tsk->euid == value); |
333 | break; |
334 | case AUDIT_SUID: |
335 | result = (tsk->suid == value); |
336 | break; |
337 | case AUDIT_FSUID: |
338 | result = (tsk->fsuid == value); |
339 | break; |
340 | case AUDIT_GID: |
341 | result = (tsk->gid == value); |
342 | break; |
343 | case AUDIT_EGID: |
344 | result = (tsk->egid == value); |
345 | break; |
346 | case AUDIT_SGID: |
347 | result = (tsk->sgid == value); |
348 | break; |
349 | case AUDIT_FSGID: |
350 | result = (tsk->fsgid == value); |
351 | break; |
352 | case AUDIT_PERS: |
353 | result = (tsk->personality == value); |
354 | break; |
355 | case AUDIT_ARCH: |
356 | if (ctx) |
357 | result = (ctx->arch == value); |
358 | break; |
359 | |
360 | case AUDIT_EXIT: |
361 | if (ctx && ctx->return_valid) |
362 | result = (ctx->return_code == value); |
363 | break; |
364 | case AUDIT_SUCCESS: |
365 | if (ctx && ctx->return_valid) |
366 | result = (ctx->return_valid == AUDITSC_SUCCESS); |
367 | break; |
368 | case AUDIT_DEVMAJOR: |
369 | if (ctx) { |
370 | for (j = 0; j < ctx->name_count; j++) { |
371 | if (MAJOR(ctx->names[j].dev)==value) { |
372 | ++result; |
373 | break; |
374 | } |
375 | } |
376 | } |
377 | break; |
378 | case AUDIT_DEVMINOR: |
379 | if (ctx) { |
380 | for (j = 0; j < ctx->name_count; j++) { |
381 | if (MINOR(ctx->names[j].dev)==value) { |
382 | ++result; |
383 | break; |
384 | } |
385 | } |
386 | } |
387 | break; |
388 | case AUDIT_INODE: |
389 | if (ctx) { |
390 | for (j = 0; j < ctx->name_count; j++) { |
391 | if (ctx->names[j].ino == value) { |
392 | ++result; |
393 | break; |
394 | } |
395 | } |
396 | } |
397 | break; |
398 | case AUDIT_LOGINUID: |
399 | result = 0; |
400 | if (ctx) |
401 | result = (ctx->loginuid == value); |
402 | break; |
403 | case AUDIT_ARG0: |
404 | case AUDIT_ARG1: |
405 | case AUDIT_ARG2: |
406 | case AUDIT_ARG3: |
407 | if (ctx) |
408 | result = (ctx->argv[field-AUDIT_ARG0]==value); |
409 | break; |
410 | } |
411 | |
412 | if (rule->fields[i] & AUDIT_NEGATE) |
413 | result = !result; |
414 | if (!result) |
415 | return 0; |
416 | } |
417 | switch (rule->action) { |
418 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; |
419 | case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break; |
420 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; |
421 | } |
422 | return 1; |
423 | } |
424 | |
425 | /* At process creation time, we can determine if system-call auditing is |
426 | * completely disabled for this task. Since we only have the task |
427 | * structure at this point, we can only check uid and gid. |
428 | */ |
429 | static enum audit_state audit_filter_task(struct task_struct *tsk) |
430 | { |
431 | struct audit_entry *e; |
432 | enum audit_state state; |
433 | |
434 | rcu_read_lock(); |
435 | list_for_each_entry_rcu(e, &audit_tsklist, list) { |
436 | if (audit_filter_rules(tsk, &e->rule, NULL, &state)) { |
437 | rcu_read_unlock(); |
438 | return state; |
439 | } |
440 | } |
441 | rcu_read_unlock(); |
442 | return AUDIT_BUILD_CONTEXT; |
443 | } |
444 | |
445 | /* At syscall entry and exit time, this filter is called if the |
446 | * audit_state is not low enough that auditing cannot take place, but is |
447 | * also not high enough that we already know we have to write and audit |
448 | * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT). |
449 | */ |
450 | static enum audit_state audit_filter_syscall(struct task_struct *tsk, |
451 | struct audit_context *ctx, |
452 | struct list_head *list) |
453 | { |
454 | struct audit_entry *e; |
455 | enum audit_state state; |
456 | int word = AUDIT_WORD(ctx->major); |
457 | int bit = AUDIT_BIT(ctx->major); |
458 | |
459 | rcu_read_lock(); |
460 | list_for_each_entry_rcu(e, list, list) { |
461 | if ((e->rule.mask[word] & bit) == bit |
462 | && audit_filter_rules(tsk, &e->rule, ctx, &state)) { |
463 | rcu_read_unlock(); |
464 | return state; |
465 | } |
466 | } |
467 | rcu_read_unlock(); |
468 | return AUDIT_BUILD_CONTEXT; |
469 | } |
470 | |
471 | /* This should be called with task_lock() held. */ |
472 | static inline struct audit_context *audit_get_context(struct task_struct *tsk, |
473 | int return_valid, |
474 | int return_code) |
475 | { |
476 | struct audit_context *context = tsk->audit_context; |
477 | |
478 | if (likely(!context)) |
479 | return NULL; |
480 | context->return_valid = return_valid; |
481 | context->return_code = return_code; |
482 | |
483 | if (context->in_syscall && !context->auditable) { |
484 | enum audit_state state; |
485 | state = audit_filter_syscall(tsk, context, &audit_extlist); |
486 | if (state == AUDIT_RECORD_CONTEXT) |
487 | context->auditable = 1; |
488 | } |
489 | |
490 | context->pid = tsk->pid; |
491 | context->uid = tsk->uid; |
492 | context->gid = tsk->gid; |
493 | context->euid = tsk->euid; |
494 | context->suid = tsk->suid; |
495 | context->fsuid = tsk->fsuid; |
496 | context->egid = tsk->egid; |
497 | context->sgid = tsk->sgid; |
498 | context->fsgid = tsk->fsgid; |
499 | context->personality = tsk->personality; |
500 | tsk->audit_context = NULL; |
501 | return context; |
502 | } |
503 | |
504 | static inline void audit_free_names(struct audit_context *context) |
505 | { |
506 | int i; |
507 | |
508 | #if AUDIT_DEBUG == 2 |
509 | if (context->auditable |
510 | ||context->put_count + context->ino_count != context->name_count) { |
511 | printk(KERN_ERR "audit.c:%d(:%d): major=%d in_syscall=%d" |
512 | " name_count=%d put_count=%d" |
513 | " ino_count=%d [NOT freeing]\n", |
514 | __LINE__, |
515 | context->serial, context->major, context->in_syscall, |
516 | context->name_count, context->put_count, |
517 | context->ino_count); |
518 | for (i = 0; i < context->name_count; i++) |
519 | printk(KERN_ERR "names[%d] = %p = %s\n", i, |
520 | context->names[i].name, |
521 | context->names[i].name); |
522 | dump_stack(); |
523 | return; |
524 | } |
525 | #endif |
526 | #if AUDIT_DEBUG |
527 | context->put_count = 0; |
528 | context->ino_count = 0; |
529 | #endif |
530 | |
531 | for (i = 0; i < context->name_count; i++) |
532 | if (context->names[i].name) |
533 | __putname(context->names[i].name); |
534 | context->name_count = 0; |
535 | } |
536 | |
537 | static inline void audit_free_aux(struct audit_context *context) |
538 | { |
539 | struct audit_aux_data *aux; |
540 | |
541 | while ((aux = context->aux)) { |
542 | context->aux = aux->next; |
543 | kfree(aux); |
544 | } |
545 | } |
546 | |
547 | static inline void audit_zero_context(struct audit_context *context, |
548 | enum audit_state state) |
549 | { |
550 | uid_t loginuid = context->loginuid; |
551 | |
552 | memset(context, 0, sizeof(*context)); |
553 | context->state = state; |
554 | context->loginuid = loginuid; |
555 | } |
556 | |
557 | static inline struct audit_context *audit_alloc_context(enum audit_state state) |
558 | { |
559 | struct audit_context *context; |
560 | |
561 | if (!(context = kmalloc(sizeof(*context), GFP_KERNEL))) |
562 | return NULL; |
563 | audit_zero_context(context, state); |
564 | return context; |
565 | } |
566 | |
567 | /* Filter on the task information and allocate a per-task audit context |
568 | * if necessary. Doing so turns on system call auditing for the |
569 | * specified task. This is called from copy_process, so no lock is |
570 | * needed. */ |
571 | int audit_alloc(struct task_struct *tsk) |
572 | { |
573 | struct audit_context *context; |
574 | enum audit_state state; |
575 | |
576 | if (likely(!audit_enabled)) |
577 | return 0; /* Return if not auditing. */ |
578 | |
579 | state = audit_filter_task(tsk); |
580 | if (likely(state == AUDIT_DISABLED)) |
581 | return 0; |
582 | |
583 | if (!(context = audit_alloc_context(state))) { |
584 | audit_log_lost("out of memory in audit_alloc"); |
585 | return -ENOMEM; |
586 | } |
587 | |
588 | /* Preserve login uid */ |
589 | context->loginuid = -1; |
590 | if (current->audit_context) |
591 | context->loginuid = current->audit_context->loginuid; |
592 | |
593 | tsk->audit_context = context; |
594 | set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT); |
595 | return 0; |
596 | } |
597 | |
598 | static inline void audit_free_context(struct audit_context *context) |
599 | { |
600 | struct audit_context *previous; |
601 | int count = 0; |
602 | |
603 | do { |
604 | previous = context->previous; |
605 | if (previous || (count && count < 10)) { |
606 | ++count; |
607 | printk(KERN_ERR "audit(:%d): major=%d name_count=%d:" |
608 | " freeing multiple contexts (%d)\n", |
609 | context->serial, context->major, |
610 | context->name_count, count); |
611 | } |
612 | audit_free_names(context); |
613 | audit_free_aux(context); |
614 | kfree(context); |
615 | context = previous; |
616 | } while (context); |
617 | if (count >= 10) |
618 | printk(KERN_ERR "audit: freed %d contexts\n", count); |
619 | } |
620 | |
621 | static void audit_log_task_info(struct audit_buffer *ab) |
622 | { |
623 | char name[sizeof(current->comm)]; |
624 | struct mm_struct *mm = current->mm; |
625 | struct vm_area_struct *vma; |
626 | |
627 | get_task_comm(name, current); |
628 | audit_log_format(ab, " comm=%s", name); |
629 | |
630 | if (!mm) |
631 | return; |
632 | |
633 | down_read(&mm->mmap_sem); |
634 | vma = mm->mmap; |
635 | while (vma) { |
636 | if ((vma->vm_flags & VM_EXECUTABLE) && |
637 | vma->vm_file) { |
638 | audit_log_d_path(ab, "exe=", |
639 | vma->vm_file->f_dentry, |
640 | vma->vm_file->f_vfsmnt); |
641 | break; |
642 | } |
643 | vma = vma->vm_next; |
644 | } |
645 | up_read(&mm->mmap_sem); |
646 | } |
647 | |
648 | static void audit_log_exit(struct audit_context *context) |
649 | { |
650 | int i; |
651 | struct audit_buffer *ab; |
652 | |
653 | ab = audit_log_start(context); |
654 | if (!ab) |
655 | return; /* audit_panic has been called */ |
656 | audit_log_format(ab, "syscall=%d", context->major); |
657 | if (context->personality != PER_LINUX) |
658 | audit_log_format(ab, " per=%lx", context->personality); |
659 | audit_log_format(ab, " arch=%x", context->arch); |
660 | if (context->return_valid) |
661 | audit_log_format(ab, " success=%s exit=%ld", |
662 | (context->return_valid==AUDITSC_SUCCESS)?"yes":"no", |
663 | context->return_code); |
664 | audit_log_format(ab, |
665 | " a0=%lx a1=%lx a2=%lx a3=%lx items=%d" |
666 | " pid=%d loginuid=%d uid=%d gid=%d" |
667 | " euid=%d suid=%d fsuid=%d" |
668 | " egid=%d sgid=%d fsgid=%d", |
669 | context->argv[0], |
670 | context->argv[1], |
671 | context->argv[2], |
672 | context->argv[3], |
673 | context->name_count, |
674 | context->pid, |
675 | context->loginuid, |
676 | context->uid, |
677 | context->gid, |
678 | context->euid, context->suid, context->fsuid, |
679 | context->egid, context->sgid, context->fsgid); |
680 | audit_log_task_info(ab); |
681 | audit_log_end(ab); |
682 | while (context->aux) { |
683 | struct audit_aux_data *aux; |
684 | |
685 | ab = audit_log_start(context); |
686 | if (!ab) |
687 | continue; /* audit_panic has been called */ |
688 | |
689 | aux = context->aux; |
690 | context->aux = aux->next; |
691 | |
692 | audit_log_format(ab, "auxitem=%d", aux->type); |
693 | switch (aux->type) { |
694 | case AUDIT_AUX_IPCPERM: { |
695 | struct audit_aux_data_ipcctl *axi = (void *)aux; |
696 | audit_log_format(ab, |
697 | " qbytes=%lx uid=%d gid=%d mode=%x", |
698 | axi->qbytes, axi->uid, axi->gid, axi->mode); |
699 | } |
700 | } |
701 | audit_log_end(ab); |
702 | kfree(aux); |
703 | } |
704 | |
705 | for (i = 0; i < context->name_count; i++) { |
706 | ab = audit_log_start(context); |
707 | if (!ab) |
708 | continue; /* audit_panic has been called */ |
709 | audit_log_format(ab, "item=%d", i); |
710 | if (context->names[i].name) { |
711 | audit_log_format(ab, " name="); |
712 | audit_log_untrustedstring(ab, context->names[i].name); |
713 | } |
714 | if (context->names[i].ino != (unsigned long)-1) |
715 | audit_log_format(ab, " inode=%lu dev=%02x:%02x mode=%#o" |
716 | " uid=%d gid=%d rdev=%02x:%02x", |
717 | context->names[i].ino, |
718 | MAJOR(context->names[i].dev), |
719 | MINOR(context->names[i].dev), |
720 | context->names[i].mode, |
721 | context->names[i].uid, |
722 | context->names[i].gid, |
723 | MAJOR(context->names[i].rdev), |
724 | MINOR(context->names[i].rdev)); |
725 | audit_log_end(ab); |
726 | } |
727 | } |
728 | |
729 | /* Free a per-task audit context. Called from copy_process and |
730 | * __put_task_struct. */ |
731 | void audit_free(struct task_struct *tsk) |
732 | { |
733 | struct audit_context *context; |
734 | |
735 | task_lock(tsk); |
736 | context = audit_get_context(tsk, 0, 0); |
737 | task_unlock(tsk); |
738 | |
739 | if (likely(!context)) |
740 | return; |
741 | |
742 | /* Check for system calls that do not go through the exit |
743 | * function (e.g., exit_group), then free context block. */ |
744 | if (context->in_syscall && context->auditable) |
745 | audit_log_exit(context); |
746 | |
747 | audit_free_context(context); |
748 | } |
749 | |
750 | /* Compute a serial number for the audit record. Audit records are |
751 | * written to user-space as soon as they are generated, so a complete |
752 | * audit record may be written in several pieces. The timestamp of the |
753 | * record and this serial number are used by the user-space daemon to |
754 | * determine which pieces belong to the same audit record. The |
755 | * (timestamp,serial) tuple is unique for each syscall and is live from |
756 | * syscall entry to syscall exit. |
757 | * |
758 | * Atomic values are only guaranteed to be 24-bit, so we count down. |
759 | * |
760 | * NOTE: Another possibility is to store the formatted records off the |
761 | * audit context (for those records that have a context), and emit them |
762 | * all at syscall exit. However, this could delay the reporting of |
763 | * significant errors until syscall exit (or never, if the system |
764 | * halts). */ |
765 | static inline unsigned int audit_serial(void) |
766 | { |
767 | static atomic_t serial = ATOMIC_INIT(0xffffff); |
768 | unsigned int a, b; |
769 | |
770 | do { |
771 | a = atomic_read(&serial); |
772 | if (atomic_dec_and_test(&serial)) |
773 | atomic_set(&serial, 0xffffff); |
774 | b = atomic_read(&serial); |
775 | } while (b != a - 1); |
776 | |
777 | return 0xffffff - b; |
778 | } |
779 | |
780 | /* Fill in audit context at syscall entry. This only happens if the |
781 | * audit context was created when the task was created and the state or |
782 | * filters demand the audit context be built. If the state from the |
783 | * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT, |
784 | * then the record will be written at syscall exit time (otherwise, it |
785 | * will only be written if another part of the kernel requests that it |
786 | * be written). */ |
787 | void audit_syscall_entry(struct task_struct *tsk, int arch, int major, |
788 | unsigned long a1, unsigned long a2, |
789 | unsigned long a3, unsigned long a4) |
790 | { |
791 | struct audit_context *context = tsk->audit_context; |
792 | enum audit_state state; |
793 | |
794 | BUG_ON(!context); |
795 | |
796 | /* This happens only on certain architectures that make system |
797 | * calls in kernel_thread via the entry.S interface, instead of |
798 | * with direct calls. (If you are porting to a new |
799 | * architecture, hitting this condition can indicate that you |
800 | * got the _exit/_leave calls backward in entry.S.) |
801 | * |
802 | * i386 no |
803 | * x86_64 no |
804 | * ppc64 yes (see arch/ppc64/kernel/misc.S) |
805 | * |
806 | * This also happens with vm86 emulation in a non-nested manner |
807 | * (entries without exits), so this case must be caught. |
808 | */ |
809 | if (context->in_syscall) { |
810 | struct audit_context *newctx; |
811 | |
812 | #if defined(__NR_vm86) && defined(__NR_vm86old) |
813 | /* vm86 mode should only be entered once */ |
814 | if (major == __NR_vm86 || major == __NR_vm86old) |
815 | return; |
816 | #endif |
817 | #if AUDIT_DEBUG |
818 | printk(KERN_ERR |
819 | "audit(:%d) pid=%d in syscall=%d;" |
820 | " entering syscall=%d\n", |
821 | context->serial, tsk->pid, context->major, major); |
822 | #endif |
823 | newctx = audit_alloc_context(context->state); |
824 | if (newctx) { |
825 | newctx->previous = context; |
826 | context = newctx; |
827 | tsk->audit_context = newctx; |
828 | } else { |
829 | /* If we can't alloc a new context, the best we |
830 | * can do is to leak memory (any pending putname |
831 | * will be lost). The only other alternative is |
832 | * to abandon auditing. */ |
833 | audit_zero_context(context, context->state); |
834 | } |
835 | } |
836 | BUG_ON(context->in_syscall || context->name_count); |
837 | |
838 | if (!audit_enabled) |
839 | return; |
840 | |
841 | context->arch = arch; |
842 | context->major = major; |
843 | context->argv[0] = a1; |
844 | context->argv[1] = a2; |
845 | context->argv[2] = a3; |
846 | context->argv[3] = a4; |
847 | |
848 | state = context->state; |
849 | if (state == AUDIT_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT) |
850 | state = audit_filter_syscall(tsk, context, &audit_entlist); |
851 | if (likely(state == AUDIT_DISABLED)) |
852 | return; |
853 | |
854 | context->serial = audit_serial(); |
855 | context->ctime = CURRENT_TIME; |
856 | context->in_syscall = 1; |
857 | context->auditable = !!(state == AUDIT_RECORD_CONTEXT); |
858 | } |
859 | |
860 | /* Tear down after system call. If the audit context has been marked as |
861 | * auditable (either because of the AUDIT_RECORD_CONTEXT state from |
862 | * filtering, or because some other part of the kernel write an audit |
863 | * message), then write out the syscall information. In call cases, |
864 | * free the names stored from getname(). */ |
865 | void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code) |
866 | { |
867 | struct audit_context *context; |
868 | |
869 | get_task_struct(tsk); |
870 | task_lock(tsk); |
871 | context = audit_get_context(tsk, valid, return_code); |
872 | task_unlock(tsk); |
873 | |
874 | /* Not having a context here is ok, since the parent may have |
875 | * called __put_task_struct. */ |
876 | if (likely(!context)) |
877 | return; |
878 | |
879 | if (context->in_syscall && context->auditable) |
880 | audit_log_exit(context); |
881 | |
882 | context->in_syscall = 0; |
883 | context->auditable = 0; |
884 | |
885 | if (context->previous) { |
886 | struct audit_context *new_context = context->previous; |
887 | context->previous = NULL; |
888 | audit_free_context(context); |
889 | tsk->audit_context = new_context; |
890 | } else { |
891 | audit_free_names(context); |
892 | audit_free_aux(context); |
893 | audit_zero_context(context, context->state); |
894 | tsk->audit_context = context; |
895 | } |
896 | put_task_struct(tsk); |
897 | } |
898 | |
899 | /* Add a name to the list. Called from fs/namei.c:getname(). */ |
900 | void audit_getname(const char *name) |
901 | { |
902 | struct audit_context *context = current->audit_context; |
903 | |
904 | if (!context || IS_ERR(name) || !name) |
905 | return; |
906 | |
907 | if (!context->in_syscall) { |
908 | #if AUDIT_DEBUG == 2 |
909 | printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)\n", |
910 | __FILE__, __LINE__, context->serial, name); |
911 | dump_stack(); |
912 | #endif |
913 | return; |
914 | } |
915 | BUG_ON(context->name_count >= AUDIT_NAMES); |
916 | context->names[context->name_count].name = name; |
917 | context->names[context->name_count].ino = (unsigned long)-1; |
918 | ++context->name_count; |
919 | } |
920 | |
921 | /* Intercept a putname request. Called from |
922 | * include/linux/fs.h:putname(). If we have stored the name from |
923 | * getname in the audit context, then we delay the putname until syscall |
924 | * exit. */ |
925 | void audit_putname(const char *name) |
926 | { |
927 | struct audit_context *context = current->audit_context; |
928 | |
929 | BUG_ON(!context); |
930 | if (!context->in_syscall) { |
931 | #if AUDIT_DEBUG == 2 |
932 | printk(KERN_ERR "%s:%d(:%d): __putname(%p)\n", |
933 | __FILE__, __LINE__, context->serial, name); |
934 | if (context->name_count) { |
935 | int i; |
936 | for (i = 0; i < context->name_count; i++) |
937 | printk(KERN_ERR "name[%d] = %p = %s\n", i, |
938 | context->names[i].name, |
939 | context->names[i].name); |
940 | } |
941 | #endif |
942 | __putname(name); |
943 | } |
944 | #if AUDIT_DEBUG |
945 | else { |
946 | ++context->put_count; |
947 | if (context->put_count > context->name_count) { |
948 | printk(KERN_ERR "%s:%d(:%d): major=%d" |
949 | " in_syscall=%d putname(%p) name_count=%d" |
950 | " put_count=%d\n", |
951 | __FILE__, __LINE__, |
952 | context->serial, context->major, |
953 | context->in_syscall, name, context->name_count, |
954 | context->put_count); |
955 | dump_stack(); |
956 | } |
957 | } |
958 | #endif |
959 | } |
960 | |
961 | /* Store the inode and device from a lookup. Called from |
962 | * fs/namei.c:path_lookup(). */ |
963 | void audit_inode(const char *name, const struct inode *inode) |
964 | { |
965 | int idx; |
966 | struct audit_context *context = current->audit_context; |
967 | |
968 | if (!context->in_syscall) |
969 | return; |
970 | if (context->name_count |
971 | && context->names[context->name_count-1].name |
972 | && context->names[context->name_count-1].name == name) |
973 | idx = context->name_count - 1; |
974 | else if (context->name_count > 1 |
975 | && context->names[context->name_count-2].name |
976 | && context->names[context->name_count-2].name == name) |
977 | idx = context->name_count - 2; |
978 | else { |
979 | /* FIXME: how much do we care about inodes that have no |
980 | * associated name? */ |
981 | if (context->name_count >= AUDIT_NAMES - AUDIT_NAMES_RESERVED) |
982 | return; |
983 | idx = context->name_count++; |
984 | context->names[idx].name = NULL; |
985 | #if AUDIT_DEBUG |
986 | ++context->ino_count; |
987 | #endif |
988 | } |
989 | context->names[idx].ino = inode->i_ino; |
990 | context->names[idx].dev = inode->i_sb->s_dev; |
991 | context->names[idx].mode = inode->i_mode; |
992 | context->names[idx].uid = inode->i_uid; |
993 | context->names[idx].gid = inode->i_gid; |
994 | context->names[idx].rdev = inode->i_rdev; |
995 | } |
996 | |
997 | void audit_get_stamp(struct audit_context *ctx, |
998 | struct timespec *t, unsigned int *serial) |
999 | { |
1000 | if (ctx) { |
1001 | t->tv_sec = ctx->ctime.tv_sec; |
1002 | t->tv_nsec = ctx->ctime.tv_nsec; |
1003 | *serial = ctx->serial; |
1004 | ctx->auditable = 1; |
1005 | } else { |
1006 | *t = CURRENT_TIME; |
1007 | *serial = 0; |
1008 | } |
1009 | } |
1010 | |
1011 | extern int audit_set_type(struct audit_buffer *ab, int type); |
1012 | |
1013 | int audit_set_loginuid(struct task_struct *task, uid_t loginuid) |
1014 | { |
1015 | if (task->audit_context) { |
1016 | struct audit_buffer *ab; |
1017 | |
1018 | ab = audit_log_start(NULL); |
1019 | if (ab) { |
1020 | audit_log_format(ab, "login pid=%d uid=%u " |
1021 | "old loginuid=%u new loginuid=%u", |
1022 | task->pid, task->uid, |
1023 | task->audit_context->loginuid, loginuid); |
1024 | audit_set_type(ab, AUDIT_LOGIN); |
1025 | audit_log_end(ab); |
1026 | } |
1027 | task->audit_context->loginuid = loginuid; |
1028 | } |
1029 | return 0; |
1030 | } |
1031 | |
1032 | uid_t audit_get_loginuid(struct audit_context *ctx) |
1033 | { |
1034 | return ctx ? ctx->loginuid : -1; |
1035 | } |
1036 | |
1037 | int audit_ipc_perms(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode) |
1038 | { |
1039 | struct audit_aux_data_ipcctl *ax; |
1040 | struct audit_context *context = current->audit_context; |
1041 | |
1042 | if (likely(!context)) |
1043 | return 0; |
1044 | |
1045 | ax = kmalloc(sizeof(*ax), GFP_KERNEL); |
1046 | if (!ax) |
1047 | return -ENOMEM; |
1048 | |
1049 | ax->qbytes = qbytes; |
1050 | ax->uid = uid; |
1051 | ax->gid = gid; |
1052 | ax->mode = mode; |
1053 | |
1054 | ax->d.type = AUDIT_AUX_IPCPERM; |
1055 | ax->d.next = context->aux; |
1056 | context->aux = (void *)ax; |
1057 | return 0; |
1058 | } |