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85c87212005-04-29 16:23:29 +01001/* auditsc.c -- System-call auditing support
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * 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>
Stephen Smalley01116102005-05-21 00:15:52 +010037#include <linux/mount.h>
David Woodhouse3ec3b2f2005-05-17 12:08:48 +010038#include <linux/socket.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#include <linux/audit.h>
40#include <linux/personality.h>
41#include <linux/time.h>
42#include <asm/unistd.h>
43
44/* 0 = no checking
45 1 = put_count checking
46 2 = verbose put_count checking
47*/
48#define AUDIT_DEBUG 0
49
50/* No syscall auditing will take place unless audit_enabled != 0. */
51extern int audit_enabled;
52
53/* AUDIT_NAMES is the number of slots we reserve in the audit_context
54 * for saving names from getname(). */
55#define AUDIT_NAMES 20
56
57/* AUDIT_NAMES_RESERVED is the number of slots we reserve in the
58 * audit_context from being used for nameless inodes from
59 * path_lookup. */
60#define AUDIT_NAMES_RESERVED 7
61
62/* At task start time, the audit_state is set in the audit_context using
63 a per-task filter. At syscall entry, the audit_state is augmented by
64 the syscall filter. */
65enum audit_state {
66 AUDIT_DISABLED, /* Do not create per-task audit_context.
67 * No syscall-specific audit records can
68 * be generated. */
69 AUDIT_SETUP_CONTEXT, /* Create the per-task audit_context,
70 * but don't necessarily fill it in at
71 * syscall entry time (i.e., filter
72 * instead). */
73 AUDIT_BUILD_CONTEXT, /* Create the per-task audit_context,
74 * and always fill it in at syscall
75 * entry time. This makes a full
76 * syscall record available if some
77 * other part of the kernel decides it
78 * should be recorded. */
79 AUDIT_RECORD_CONTEXT /* Create the per-task audit_context,
80 * always fill it in at syscall entry
81 * time, and always write out the audit
82 * record at syscall exit time. */
83};
84
85/* When fs/namei.c:getname() is called, we store the pointer in name and
86 * we don't let putname() free it (instead we free all of the saved
87 * pointers at syscall exit time).
88 *
89 * Further, in fs/namei.c:path_lookup() we store the inode and device. */
90struct audit_names {
91 const char *name;
92 unsigned long ino;
93 dev_t dev;
94 umode_t mode;
95 uid_t uid;
96 gid_t gid;
97 dev_t rdev;
98};
99
100struct audit_aux_data {
101 struct audit_aux_data *next;
102 int type;
103};
104
105#define AUDIT_AUX_IPCPERM 0
106
107struct audit_aux_data_ipcctl {
108 struct audit_aux_data d;
109 struct ipc_perm p;
110 unsigned long qbytes;
111 uid_t uid;
112 gid_t gid;
113 mode_t mode;
114};
115
David Woodhouse3ec3b2f2005-05-17 12:08:48 +0100116struct audit_aux_data_socketcall {
117 struct audit_aux_data d;
118 int nargs;
119 unsigned long args[0];
120};
121
122struct audit_aux_data_sockaddr {
123 struct audit_aux_data d;
124 int len;
125 char a[0];
126};
127
Stephen Smalley01116102005-05-21 00:15:52 +0100128struct audit_aux_data_path {
129 struct audit_aux_data d;
130 struct dentry *dentry;
131 struct vfsmount *mnt;
132};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
134/* The per-task audit context. */
135struct audit_context {
136 int in_syscall; /* 1 if task is in a syscall */
137 enum audit_state state;
138 unsigned int serial; /* serial number for record */
139 struct timespec ctime; /* time of syscall entry */
140 uid_t loginuid; /* login uid (identity) */
141 int major; /* syscall number */
142 unsigned long argv[4]; /* syscall arguments */
143 int return_valid; /* return code is valid */
2fd6f582005-04-29 16:08:28 +0100144 long return_code;/* syscall return code */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 int auditable; /* 1 if record should be written */
146 int name_count;
147 struct audit_names names[AUDIT_NAMES];
148 struct audit_context *previous; /* For nested syscalls */
149 struct audit_aux_data *aux;
150
151 /* Save things to print about task_struct */
152 pid_t pid;
153 uid_t uid, euid, suid, fsuid;
154 gid_t gid, egid, sgid, fsgid;
155 unsigned long personality;
2fd6f582005-04-29 16:08:28 +0100156 int arch;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
158#if AUDIT_DEBUG
159 int put_count;
160 int ino_count;
161#endif
162};
163
164 /* Public API */
165/* There are three lists of rules -- one to search at task creation
166 * time, one to search at syscall entry time, and another to search at
167 * syscall exit time. */
168static LIST_HEAD(audit_tsklist);
169static LIST_HEAD(audit_entlist);
170static LIST_HEAD(audit_extlist);
171
172struct audit_entry {
173 struct list_head list;
174 struct rcu_head rcu;
175 struct audit_rule rule;
176};
177
David Woodhouse7ca00262005-05-19 11:23:13 +0100178extern int audit_pid;
179
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180/* Check to see if two rules are identical. It is called from
181 * audit_del_rule during AUDIT_DEL. */
182static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b)
183{
184 int i;
185
186 if (a->flags != b->flags)
187 return 1;
188
189 if (a->action != b->action)
190 return 1;
191
192 if (a->field_count != b->field_count)
193 return 1;
194
195 for (i = 0; i < a->field_count; i++) {
196 if (a->fields[i] != b->fields[i]
197 || a->values[i] != b->values[i])
198 return 1;
199 }
200
201 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
202 if (a->mask[i] != b->mask[i])
203 return 1;
204
205 return 0;
206}
207
208/* Note that audit_add_rule and audit_del_rule are called via
209 * audit_receive() in audit.c, and are protected by
210 * audit_netlink_sem. */
211static inline int audit_add_rule(struct audit_entry *entry,
212 struct list_head *list)
213{
214 if (entry->rule.flags & AUDIT_PREPEND) {
215 entry->rule.flags &= ~AUDIT_PREPEND;
216 list_add_rcu(&entry->list, list);
217 } else {
218 list_add_tail_rcu(&entry->list, list);
219 }
220 return 0;
221}
222
223static void audit_free_rule(struct rcu_head *head)
224{
225 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
226 kfree(e);
227}
228
229/* Note that audit_add_rule and audit_del_rule are called via
230 * audit_receive() in audit.c, and are protected by
231 * audit_netlink_sem. */
232static inline int audit_del_rule(struct audit_rule *rule,
233 struct list_head *list)
234{
235 struct audit_entry *e;
236
237 /* Do not use the _rcu iterator here, since this is the only
238 * deletion routine. */
239 list_for_each_entry(e, list, list) {
240 if (!audit_compare_rule(rule, &e->rule)) {
241 list_del_rcu(&e->list);
242 call_rcu(&e->rcu, audit_free_rule);
243 return 0;
244 }
245 }
246 return -EFAULT; /* No matching rule */
247}
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249/* Copy rule from user-space to kernel-space. Called during
250 * AUDIT_ADD. */
251static int audit_copy_rule(struct audit_rule *d, struct audit_rule *s)
252{
253 int i;
254
255 if (s->action != AUDIT_NEVER
256 && s->action != AUDIT_POSSIBLE
257 && s->action != AUDIT_ALWAYS)
258 return -1;
259 if (s->field_count < 0 || s->field_count > AUDIT_MAX_FIELDS)
260 return -1;
261
262 d->flags = s->flags;
263 d->action = s->action;
264 d->field_count = s->field_count;
265 for (i = 0; i < d->field_count; i++) {
266 d->fields[i] = s->fields[i];
267 d->values[i] = s->values[i];
268 }
269 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) d->mask[i] = s->mask[i];
270 return 0;
271}
272
Serge Hallync94c2572005-04-29 16:27:17 +0100273int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
274 uid_t loginuid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275{
276 u32 flags;
277 struct audit_entry *entry;
278 int err = 0;
279
280 switch (type) {
281 case AUDIT_LIST:
282 /* The *_rcu iterators not needed here because we are
283 always called with audit_netlink_sem held. */
284 list_for_each_entry(entry, &audit_tsklist, list)
285 audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
286 &entry->rule, sizeof(entry->rule));
287 list_for_each_entry(entry, &audit_entlist, list)
288 audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
289 &entry->rule, sizeof(entry->rule));
290 list_for_each_entry(entry, &audit_extlist, list)
291 audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
292 &entry->rule, sizeof(entry->rule));
293 audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
294 break;
295 case AUDIT_ADD:
296 if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL)))
297 return -ENOMEM;
298 if (audit_copy_rule(&entry->rule, data)) {
299 kfree(entry);
300 return -EINVAL;
301 }
302 flags = entry->rule.flags;
303 if (!err && (flags & AUDIT_PER_TASK))
304 err = audit_add_rule(entry, &audit_tsklist);
305 if (!err && (flags & AUDIT_AT_ENTRY))
306 err = audit_add_rule(entry, &audit_entlist);
307 if (!err && (flags & AUDIT_AT_EXIT))
308 err = audit_add_rule(entry, &audit_extlist);
Steve Grubbc0404992005-05-13 18:17:42 +0100309 audit_log(NULL, AUDIT_CONFIG_CHANGE,
310 "auid %u added an audit rule\n", loginuid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 break;
312 case AUDIT_DEL:
313 flags =((struct audit_rule *)data)->flags;
314 if (!err && (flags & AUDIT_PER_TASK))
315 err = audit_del_rule(data, &audit_tsklist);
316 if (!err && (flags & AUDIT_AT_ENTRY))
317 err = audit_del_rule(data, &audit_entlist);
318 if (!err && (flags & AUDIT_AT_EXIT))
319 err = audit_del_rule(data, &audit_extlist);
Steve Grubbc0404992005-05-13 18:17:42 +0100320 audit_log(NULL, AUDIT_CONFIG_CHANGE,
321 "auid %u removed an audit rule\n", loginuid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 break;
323 default:
324 return -EINVAL;
325 }
326
327 return err;
328}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
330/* Compare a task_struct with an audit_rule. Return 1 on match, 0
331 * otherwise. */
332static int audit_filter_rules(struct task_struct *tsk,
333 struct audit_rule *rule,
334 struct audit_context *ctx,
335 enum audit_state *state)
336{
337 int i, j;
338
339 for (i = 0; i < rule->field_count; i++) {
340 u32 field = rule->fields[i] & ~AUDIT_NEGATE;
341 u32 value = rule->values[i];
342 int result = 0;
343
344 switch (field) {
345 case AUDIT_PID:
346 result = (tsk->pid == value);
347 break;
348 case AUDIT_UID:
349 result = (tsk->uid == value);
350 break;
351 case AUDIT_EUID:
352 result = (tsk->euid == value);
353 break;
354 case AUDIT_SUID:
355 result = (tsk->suid == value);
356 break;
357 case AUDIT_FSUID:
358 result = (tsk->fsuid == value);
359 break;
360 case AUDIT_GID:
361 result = (tsk->gid == value);
362 break;
363 case AUDIT_EGID:
364 result = (tsk->egid == value);
365 break;
366 case AUDIT_SGID:
367 result = (tsk->sgid == value);
368 break;
369 case AUDIT_FSGID:
370 result = (tsk->fsgid == value);
371 break;
372 case AUDIT_PERS:
373 result = (tsk->personality == value);
374 break;
2fd6f582005-04-29 16:08:28 +0100375 case AUDIT_ARCH:
376 if (ctx)
377 result = (ctx->arch == value);
378 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379
380 case AUDIT_EXIT:
381 if (ctx && ctx->return_valid)
382 result = (ctx->return_code == value);
383 break;
384 case AUDIT_SUCCESS:
385 if (ctx && ctx->return_valid)
2fd6f582005-04-29 16:08:28 +0100386 result = (ctx->return_valid == AUDITSC_SUCCESS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 break;
388 case AUDIT_DEVMAJOR:
389 if (ctx) {
390 for (j = 0; j < ctx->name_count; j++) {
391 if (MAJOR(ctx->names[j].dev)==value) {
392 ++result;
393 break;
394 }
395 }
396 }
397 break;
398 case AUDIT_DEVMINOR:
399 if (ctx) {
400 for (j = 0; j < ctx->name_count; j++) {
401 if (MINOR(ctx->names[j].dev)==value) {
402 ++result;
403 break;
404 }
405 }
406 }
407 break;
408 case AUDIT_INODE:
409 if (ctx) {
410 for (j = 0; j < ctx->name_count; j++) {
411 if (ctx->names[j].ino == value) {
412 ++result;
413 break;
414 }
415 }
416 }
417 break;
418 case AUDIT_LOGINUID:
419 result = 0;
420 if (ctx)
421 result = (ctx->loginuid == value);
422 break;
423 case AUDIT_ARG0:
424 case AUDIT_ARG1:
425 case AUDIT_ARG2:
426 case AUDIT_ARG3:
427 if (ctx)
428 result = (ctx->argv[field-AUDIT_ARG0]==value);
429 break;
430 }
431
432 if (rule->fields[i] & AUDIT_NEGATE)
433 result = !result;
434 if (!result)
435 return 0;
436 }
437 switch (rule->action) {
438 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
439 case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break;
440 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
441 }
442 return 1;
443}
444
445/* At process creation time, we can determine if system-call auditing is
446 * completely disabled for this task. Since we only have the task
447 * structure at this point, we can only check uid and gid.
448 */
449static enum audit_state audit_filter_task(struct task_struct *tsk)
450{
451 struct audit_entry *e;
452 enum audit_state state;
453
454 rcu_read_lock();
455 list_for_each_entry_rcu(e, &audit_tsklist, list) {
456 if (audit_filter_rules(tsk, &e->rule, NULL, &state)) {
457 rcu_read_unlock();
458 return state;
459 }
460 }
461 rcu_read_unlock();
462 return AUDIT_BUILD_CONTEXT;
463}
464
465/* At syscall entry and exit time, this filter is called if the
466 * audit_state is not low enough that auditing cannot take place, but is
Steve Grubb23f32d12005-05-13 18:35:15 +0100467 * also not high enough that we already know we have to write an audit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
469 */
470static enum audit_state audit_filter_syscall(struct task_struct *tsk,
471 struct audit_context *ctx,
472 struct list_head *list)
473{
474 struct audit_entry *e;
475 enum audit_state state;
476 int word = AUDIT_WORD(ctx->major);
477 int bit = AUDIT_BIT(ctx->major);
478
479 rcu_read_lock();
480 list_for_each_entry_rcu(e, list, list) {
481 if ((e->rule.mask[word] & bit) == bit
482 && audit_filter_rules(tsk, &e->rule, ctx, &state)) {
483 rcu_read_unlock();
484 return state;
485 }
486 }
487 rcu_read_unlock();
488 return AUDIT_BUILD_CONTEXT;
489}
490
491/* This should be called with task_lock() held. */
492static inline struct audit_context *audit_get_context(struct task_struct *tsk,
493 int return_valid,
494 int return_code)
495{
496 struct audit_context *context = tsk->audit_context;
497
498 if (likely(!context))
499 return NULL;
500 context->return_valid = return_valid;
501 context->return_code = return_code;
502
503 if (context->in_syscall && !context->auditable) {
504 enum audit_state state;
505 state = audit_filter_syscall(tsk, context, &audit_extlist);
506 if (state == AUDIT_RECORD_CONTEXT)
507 context->auditable = 1;
508 }
509
510 context->pid = tsk->pid;
511 context->uid = tsk->uid;
512 context->gid = tsk->gid;
513 context->euid = tsk->euid;
514 context->suid = tsk->suid;
515 context->fsuid = tsk->fsuid;
516 context->egid = tsk->egid;
517 context->sgid = tsk->sgid;
518 context->fsgid = tsk->fsgid;
519 context->personality = tsk->personality;
520 tsk->audit_context = NULL;
521 return context;
522}
523
524static inline void audit_free_names(struct audit_context *context)
525{
526 int i;
527
528#if AUDIT_DEBUG == 2
529 if (context->auditable
530 ||context->put_count + context->ino_count != context->name_count) {
531 printk(KERN_ERR "audit.c:%d(:%d): major=%d in_syscall=%d"
532 " name_count=%d put_count=%d"
533 " ino_count=%d [NOT freeing]\n",
534 __LINE__,
535 context->serial, context->major, context->in_syscall,
536 context->name_count, context->put_count,
537 context->ino_count);
538 for (i = 0; i < context->name_count; i++)
539 printk(KERN_ERR "names[%d] = %p = %s\n", i,
540 context->names[i].name,
541 context->names[i].name);
542 dump_stack();
543 return;
544 }
545#endif
546#if AUDIT_DEBUG
547 context->put_count = 0;
548 context->ino_count = 0;
549#endif
550
551 for (i = 0; i < context->name_count; i++)
552 if (context->names[i].name)
553 __putname(context->names[i].name);
554 context->name_count = 0;
555}
556
557static inline void audit_free_aux(struct audit_context *context)
558{
559 struct audit_aux_data *aux;
560
561 while ((aux = context->aux)) {
Stephen Smalley01116102005-05-21 00:15:52 +0100562 if (aux->type == AUDIT_AVC_PATH) {
563 struct audit_aux_data_path *axi = (void *)aux;
564 dput(axi->dentry);
565 mntput(axi->mnt);
566 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 context->aux = aux->next;
568 kfree(aux);
569 }
570}
571
572static inline void audit_zero_context(struct audit_context *context,
573 enum audit_state state)
574{
575 uid_t loginuid = context->loginuid;
576
577 memset(context, 0, sizeof(*context));
578 context->state = state;
579 context->loginuid = loginuid;
580}
581
582static inline struct audit_context *audit_alloc_context(enum audit_state state)
583{
584 struct audit_context *context;
585
586 if (!(context = kmalloc(sizeof(*context), GFP_KERNEL)))
587 return NULL;
588 audit_zero_context(context, state);
589 return context;
590}
591
592/* Filter on the task information and allocate a per-task audit context
593 * if necessary. Doing so turns on system call auditing for the
594 * specified task. This is called from copy_process, so no lock is
595 * needed. */
596int audit_alloc(struct task_struct *tsk)
597{
598 struct audit_context *context;
599 enum audit_state state;
600
601 if (likely(!audit_enabled))
602 return 0; /* Return if not auditing. */
603
604 state = audit_filter_task(tsk);
605 if (likely(state == AUDIT_DISABLED))
606 return 0;
607
608 if (!(context = audit_alloc_context(state))) {
609 audit_log_lost("out of memory in audit_alloc");
610 return -ENOMEM;
611 }
612
613 /* Preserve login uid */
614 context->loginuid = -1;
615 if (current->audit_context)
616 context->loginuid = current->audit_context->loginuid;
617
618 tsk->audit_context = context;
619 set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
620 return 0;
621}
622
623static inline void audit_free_context(struct audit_context *context)
624{
625 struct audit_context *previous;
626 int count = 0;
627
628 do {
629 previous = context->previous;
630 if (previous || (count && count < 10)) {
631 ++count;
632 printk(KERN_ERR "audit(:%d): major=%d name_count=%d:"
633 " freeing multiple contexts (%d)\n",
634 context->serial, context->major,
635 context->name_count, count);
636 }
637 audit_free_names(context);
638 audit_free_aux(context);
639 kfree(context);
640 context = previous;
641 } while (context);
642 if (count >= 10)
643 printk(KERN_ERR "audit: freed %d contexts\n", count);
644}
645
Stephen Smalley219f0812005-04-18 10:47:35 -0700646static void audit_log_task_info(struct audit_buffer *ab)
647{
648 char name[sizeof(current->comm)];
649 struct mm_struct *mm = current->mm;
650 struct vm_area_struct *vma;
651
652 get_task_comm(name, current);
653 audit_log_format(ab, " comm=%s", name);
654
655 if (!mm)
656 return;
657
658 down_read(&mm->mmap_sem);
659 vma = mm->mmap;
660 while (vma) {
661 if ((vma->vm_flags & VM_EXECUTABLE) &&
662 vma->vm_file) {
663 audit_log_d_path(ab, "exe=",
664 vma->vm_file->f_dentry,
665 vma->vm_file->f_vfsmnt);
666 break;
667 }
668 vma = vma->vm_next;
669 }
670 up_read(&mm->mmap_sem);
671}
672
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673static void audit_log_exit(struct audit_context *context)
674{
675 int i;
676 struct audit_buffer *ab;
677
Steve Grubbc0404992005-05-13 18:17:42 +0100678 ab = audit_log_start(context, AUDIT_SYSCALL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 if (!ab)
680 return; /* audit_panic has been called */
681 audit_log_format(ab, "syscall=%d", context->major);
682 if (context->personality != PER_LINUX)
683 audit_log_format(ab, " per=%lx", context->personality);
2fd6f582005-04-29 16:08:28 +0100684 audit_log_format(ab, " arch=%x", context->arch);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 if (context->return_valid)
2fd6f582005-04-29 16:08:28 +0100686 audit_log_format(ab, " success=%s exit=%ld",
687 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
688 context->return_code);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 audit_log_format(ab,
690 " a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
Steve Grubb326e9c82005-05-21 00:22:31 +0100691 " pid=%d auid=%u uid=%u gid=%u"
692 " euid=%u suid=%u fsuid=%u"
693 " egid=%u sgid=%u fsgid=%u",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 context->argv[0],
695 context->argv[1],
696 context->argv[2],
697 context->argv[3],
698 context->name_count,
699 context->pid,
700 context->loginuid,
701 context->uid,
702 context->gid,
703 context->euid, context->suid, context->fsuid,
704 context->egid, context->sgid, context->fsgid);
Stephen Smalley219f0812005-04-18 10:47:35 -0700705 audit_log_task_info(ab);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 audit_log_end(ab);
707 while (context->aux) {
708 struct audit_aux_data *aux;
709
Steve Grubbc0404992005-05-13 18:17:42 +0100710 aux = context->aux;
711
712 ab = audit_log_start(context, aux->type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 if (!ab)
714 continue; /* audit_panic has been called */
715
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 switch (aux->type) {
Steve Grubbc0404992005-05-13 18:17:42 +0100717 case AUDIT_IPC: {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 struct audit_aux_data_ipcctl *axi = (void *)aux;
719 audit_log_format(ab,
Steve Grubb326e9c82005-05-21 00:22:31 +0100720 " qbytes=%lx iuid=%u igid=%u mode=%x",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 axi->qbytes, axi->uid, axi->gid, axi->mode);
David Woodhouse3ec3b2f2005-05-17 12:08:48 +0100722 break; }
723
724 case AUDIT_SOCKETCALL: {
725 int i;
726 struct audit_aux_data_socketcall *axs = (void *)aux;
727 audit_log_format(ab, "nargs=%d", axs->nargs);
728 for (i=0; i<axs->nargs; i++)
729 audit_log_format(ab, " a%d=%lx", i, axs->args[i]);
730 break; }
731
732 case AUDIT_SOCKADDR: {
733 struct audit_aux_data_sockaddr *axs = (void *)aux;
734
735 audit_log_format(ab, "saddr=");
736 audit_log_hex(ab, axs->a, axs->len);
737 break; }
Stephen Smalley01116102005-05-21 00:15:52 +0100738
739 case AUDIT_AVC_PATH: {
740 struct audit_aux_data_path *axi = (void *)aux;
741 audit_log_d_path(ab, "path=", axi->dentry, axi->mnt);
742 dput(axi->dentry);
743 mntput(axi->mnt);
744 break; }
745
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 }
747 audit_log_end(ab);
Steve Grubbc0404992005-05-13 18:17:42 +0100748
749 context->aux = aux->next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 kfree(aux);
751 }
752
753 for (i = 0; i < context->name_count; i++) {
Steve Grubbc0404992005-05-13 18:17:42 +0100754 ab = audit_log_start(context, AUDIT_PATH);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 if (!ab)
756 continue; /* audit_panic has been called */
757 audit_log_format(ab, "item=%d", i);
83c7d092005-04-29 15:54:44 +0100758 if (context->names[i].name) {
759 audit_log_format(ab, " name=");
760 audit_log_untrustedstring(ab, context->names[i].name);
761 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 if (context->names[i].ino != (unsigned long)-1)
763 audit_log_format(ab, " inode=%lu dev=%02x:%02x mode=%#o"
Steve Grubb326e9c82005-05-21 00:22:31 +0100764 " ouid=%u ogid=%u rdev=%02x:%02x",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 context->names[i].ino,
766 MAJOR(context->names[i].dev),
767 MINOR(context->names[i].dev),
768 context->names[i].mode,
769 context->names[i].uid,
770 context->names[i].gid,
771 MAJOR(context->names[i].rdev),
772 MINOR(context->names[i].rdev));
773 audit_log_end(ab);
774 }
775}
776
777/* Free a per-task audit context. Called from copy_process and
778 * __put_task_struct. */
779void audit_free(struct task_struct *tsk)
780{
781 struct audit_context *context;
782
783 task_lock(tsk);
784 context = audit_get_context(tsk, 0, 0);
785 task_unlock(tsk);
786
787 if (likely(!context))
788 return;
789
790 /* Check for system calls that do not go through the exit
791 * function (e.g., exit_group), then free context block. */
David Woodhouse7ca00262005-05-19 11:23:13 +0100792 if (context->in_syscall && context->auditable && context->pid != audit_pid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 audit_log_exit(context);
794
795 audit_free_context(context);
796}
797
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798/* Fill in audit context at syscall entry. This only happens if the
799 * audit context was created when the task was created and the state or
800 * filters demand the audit context be built. If the state from the
801 * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
802 * then the record will be written at syscall exit time (otherwise, it
803 * will only be written if another part of the kernel requests that it
804 * be written). */
2fd6f582005-04-29 16:08:28 +0100805void audit_syscall_entry(struct task_struct *tsk, int arch, int major,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 unsigned long a1, unsigned long a2,
807 unsigned long a3, unsigned long a4)
808{
809 struct audit_context *context = tsk->audit_context;
810 enum audit_state state;
811
812 BUG_ON(!context);
813
814 /* This happens only on certain architectures that make system
815 * calls in kernel_thread via the entry.S interface, instead of
816 * with direct calls. (If you are porting to a new
817 * architecture, hitting this condition can indicate that you
818 * got the _exit/_leave calls backward in entry.S.)
819 *
820 * i386 no
821 * x86_64 no
822 * ppc64 yes (see arch/ppc64/kernel/misc.S)
823 *
824 * This also happens with vm86 emulation in a non-nested manner
825 * (entries without exits), so this case must be caught.
826 */
827 if (context->in_syscall) {
828 struct audit_context *newctx;
829
830#if defined(__NR_vm86) && defined(__NR_vm86old)
831 /* vm86 mode should only be entered once */
832 if (major == __NR_vm86 || major == __NR_vm86old)
833 return;
834#endif
835#if AUDIT_DEBUG
836 printk(KERN_ERR
837 "audit(:%d) pid=%d in syscall=%d;"
838 " entering syscall=%d\n",
839 context->serial, tsk->pid, context->major, major);
840#endif
841 newctx = audit_alloc_context(context->state);
842 if (newctx) {
843 newctx->previous = context;
844 context = newctx;
845 tsk->audit_context = newctx;
846 } else {
847 /* If we can't alloc a new context, the best we
848 * can do is to leak memory (any pending putname
849 * will be lost). The only other alternative is
850 * to abandon auditing. */
851 audit_zero_context(context, context->state);
852 }
853 }
854 BUG_ON(context->in_syscall || context->name_count);
855
856 if (!audit_enabled)
857 return;
858
2fd6f582005-04-29 16:08:28 +0100859 context->arch = arch;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 context->major = major;
861 context->argv[0] = a1;
862 context->argv[1] = a2;
863 context->argv[2] = a3;
864 context->argv[3] = a4;
865
866 state = context->state;
867 if (state == AUDIT_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT)
868 state = audit_filter_syscall(tsk, context, &audit_entlist);
869 if (likely(state == AUDIT_DISABLED))
870 return;
871
872 context->serial = audit_serial();
873 context->ctime = CURRENT_TIME;
874 context->in_syscall = 1;
875 context->auditable = !!(state == AUDIT_RECORD_CONTEXT);
876}
877
878/* Tear down after system call. If the audit context has been marked as
879 * auditable (either because of the AUDIT_RECORD_CONTEXT state from
880 * filtering, or because some other part of the kernel write an audit
881 * message), then write out the syscall information. In call cases,
882 * free the names stored from getname(). */
2fd6f582005-04-29 16:08:28 +0100883void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884{
885 struct audit_context *context;
886
887 get_task_struct(tsk);
888 task_lock(tsk);
2fd6f582005-04-29 16:08:28 +0100889 context = audit_get_context(tsk, valid, return_code);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 task_unlock(tsk);
891
892 /* Not having a context here is ok, since the parent may have
893 * called __put_task_struct. */
894 if (likely(!context))
895 return;
896
David Woodhouse7ca00262005-05-19 11:23:13 +0100897 if (context->in_syscall && context->auditable && context->pid != audit_pid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 audit_log_exit(context);
899
900 context->in_syscall = 0;
901 context->auditable = 0;
2fd6f582005-04-29 16:08:28 +0100902
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 if (context->previous) {
904 struct audit_context *new_context = context->previous;
905 context->previous = NULL;
906 audit_free_context(context);
907 tsk->audit_context = new_context;
908 } else {
909 audit_free_names(context);
910 audit_free_aux(context);
911 audit_zero_context(context, context->state);
912 tsk->audit_context = context;
913 }
914 put_task_struct(tsk);
915}
916
917/* Add a name to the list. Called from fs/namei.c:getname(). */
918void audit_getname(const char *name)
919{
920 struct audit_context *context = current->audit_context;
921
922 if (!context || IS_ERR(name) || !name)
923 return;
924
925 if (!context->in_syscall) {
926#if AUDIT_DEBUG == 2
927 printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)\n",
928 __FILE__, __LINE__, context->serial, name);
929 dump_stack();
930#endif
931 return;
932 }
933 BUG_ON(context->name_count >= AUDIT_NAMES);
934 context->names[context->name_count].name = name;
935 context->names[context->name_count].ino = (unsigned long)-1;
936 ++context->name_count;
937}
938
939/* Intercept a putname request. Called from
940 * include/linux/fs.h:putname(). If we have stored the name from
941 * getname in the audit context, then we delay the putname until syscall
942 * exit. */
943void audit_putname(const char *name)
944{
945 struct audit_context *context = current->audit_context;
946
947 BUG_ON(!context);
948 if (!context->in_syscall) {
949#if AUDIT_DEBUG == 2
950 printk(KERN_ERR "%s:%d(:%d): __putname(%p)\n",
951 __FILE__, __LINE__, context->serial, name);
952 if (context->name_count) {
953 int i;
954 for (i = 0; i < context->name_count; i++)
955 printk(KERN_ERR "name[%d] = %p = %s\n", i,
956 context->names[i].name,
957 context->names[i].name);
958 }
959#endif
960 __putname(name);
961 }
962#if AUDIT_DEBUG
963 else {
964 ++context->put_count;
965 if (context->put_count > context->name_count) {
966 printk(KERN_ERR "%s:%d(:%d): major=%d"
967 " in_syscall=%d putname(%p) name_count=%d"
968 " put_count=%d\n",
969 __FILE__, __LINE__,
970 context->serial, context->major,
971 context->in_syscall, name, context->name_count,
972 context->put_count);
973 dump_stack();
974 }
975 }
976#endif
977}
978
979/* Store the inode and device from a lookup. Called from
980 * fs/namei.c:path_lookup(). */
981void audit_inode(const char *name, const struct inode *inode)
982{
983 int idx;
984 struct audit_context *context = current->audit_context;
985
986 if (!context->in_syscall)
987 return;
988 if (context->name_count
989 && context->names[context->name_count-1].name
990 && context->names[context->name_count-1].name == name)
991 idx = context->name_count - 1;
992 else if (context->name_count > 1
993 && context->names[context->name_count-2].name
994 && context->names[context->name_count-2].name == name)
995 idx = context->name_count - 2;
996 else {
997 /* FIXME: how much do we care about inodes that have no
998 * associated name? */
999 if (context->name_count >= AUDIT_NAMES - AUDIT_NAMES_RESERVED)
1000 return;
1001 idx = context->name_count++;
1002 context->names[idx].name = NULL;
1003#if AUDIT_DEBUG
1004 ++context->ino_count;
1005#endif
1006 }
1007 context->names[idx].ino = inode->i_ino;
1008 context->names[idx].dev = inode->i_sb->s_dev;
1009 context->names[idx].mode = inode->i_mode;
1010 context->names[idx].uid = inode->i_uid;
1011 context->names[idx].gid = inode->i_gid;
1012 context->names[idx].rdev = inode->i_rdev;
1013}
1014
David Woodhousebfb44962005-05-21 21:08:09 +01001015void auditsc_get_stamp(struct audit_context *ctx,
1016 struct timespec *t, unsigned int *serial)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017{
David Woodhousebfb44962005-05-21 21:08:09 +01001018 t->tv_sec = ctx->ctime.tv_sec;
1019 t->tv_nsec = ctx->ctime.tv_nsec;
1020 *serial = ctx->serial;
1021 ctx->auditable = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022}
1023
Steve Grubb456be6c2005-04-29 17:30:07 +01001024int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025{
Steve Grubb456be6c2005-04-29 17:30:07 +01001026 if (task->audit_context) {
Steve Grubbc0404992005-05-13 18:17:42 +01001027 struct audit_buffer *ab;
1028
1029 ab = audit_log_start(NULL, AUDIT_LOGIN);
1030 if (ab) {
1031 audit_log_format(ab, "login pid=%d uid=%u "
Steve Grubb326e9c82005-05-21 00:22:31 +01001032 "old auid=%u new auid=%u",
Steve Grubbc0404992005-05-13 18:17:42 +01001033 task->pid, task->uid,
1034 task->audit_context->loginuid, loginuid);
1035 audit_log_end(ab);
1036 }
Steve Grubb456be6c2005-04-29 17:30:07 +01001037 task->audit_context->loginuid = loginuid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 }
1039 return 0;
1040}
1041
1042uid_t audit_get_loginuid(struct audit_context *ctx)
1043{
1044 return ctx ? ctx->loginuid : -1;
1045}
1046
1047int audit_ipc_perms(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
1048{
1049 struct audit_aux_data_ipcctl *ax;
1050 struct audit_context *context = current->audit_context;
1051
1052 if (likely(!context))
1053 return 0;
1054
1055 ax = kmalloc(sizeof(*ax), GFP_KERNEL);
1056 if (!ax)
1057 return -ENOMEM;
1058
1059 ax->qbytes = qbytes;
1060 ax->uid = uid;
1061 ax->gid = gid;
1062 ax->mode = mode;
1063
Steve Grubbc0404992005-05-13 18:17:42 +01001064 ax->d.type = AUDIT_IPC;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065 ax->d.next = context->aux;
1066 context->aux = (void *)ax;
1067 return 0;
1068}
Steve Grubbc2f0c7c2005-05-06 12:38:39 +01001069
David Woodhouse3ec3b2f2005-05-17 12:08:48 +01001070int audit_socketcall(int nargs, unsigned long *args)
1071{
1072 struct audit_aux_data_socketcall *ax;
1073 struct audit_context *context = current->audit_context;
1074
1075 if (likely(!context))
1076 return 0;
1077
1078 ax = kmalloc(sizeof(*ax) + nargs * sizeof(unsigned long), GFP_KERNEL);
1079 if (!ax)
1080 return -ENOMEM;
1081
1082 ax->nargs = nargs;
1083 memcpy(ax->args, args, nargs * sizeof(unsigned long));
1084
1085 ax->d.type = AUDIT_SOCKETCALL;
1086 ax->d.next = context->aux;
1087 context->aux = (void *)ax;
1088 return 0;
1089}
1090
1091int audit_sockaddr(int len, void *a)
1092{
1093 struct audit_aux_data_sockaddr *ax;
1094 struct audit_context *context = current->audit_context;
1095
1096 if (likely(!context))
1097 return 0;
1098
1099 ax = kmalloc(sizeof(*ax) + len, GFP_KERNEL);
1100 if (!ax)
1101 return -ENOMEM;
1102
1103 ax->len = len;
1104 memcpy(ax->a, a, len);
1105
1106 ax->d.type = AUDIT_SOCKADDR;
1107 ax->d.next = context->aux;
1108 context->aux = (void *)ax;
1109 return 0;
1110}
1111
Stephen Smalley01116102005-05-21 00:15:52 +01001112int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
1113{
1114 struct audit_aux_data_path *ax;
1115 struct audit_context *context = current->audit_context;
1116
1117 if (likely(!context))
1118 return 0;
1119
1120 ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1121 if (!ax)
1122 return -ENOMEM;
1123
1124 ax->dentry = dget(dentry);
1125 ax->mnt = mntget(mnt);
1126
1127 ax->d.type = AUDIT_AVC_PATH;
1128 ax->d.next = context->aux;
1129 context->aux = (void *)ax;
1130 return 0;
1131}
1132
Steve Grubbc2f0c7c2005-05-06 12:38:39 +01001133void audit_signal_info(int sig, struct task_struct *t)
1134{
1135 extern pid_t audit_sig_pid;
1136 extern uid_t audit_sig_uid;
Steve Grubbc2f0c7c2005-05-06 12:38:39 +01001137
1138 if (unlikely(audit_pid && t->pid == audit_pid)) {
1139 if (sig == SIGTERM || sig == SIGHUP) {
1140 struct audit_context *ctx = current->audit_context;
1141 audit_sig_pid = current->pid;
1142 if (ctx)
1143 audit_sig_uid = ctx->loginuid;
1144 else
1145 audit_sig_uid = current->uid;
1146 }
1147 }
1148}
1149