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[PATCH] au1100fb: convert to C99 inits.
[linux-2.6/mini2440.git] / kernel / auditsc.c
blobe75f84e1a1a00d697718f603655810d8a51e7548
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 #include <linux/mount.h>
38 #include <linux/socket.h>
39 #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. */
51 extern 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. */
65 enum 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. */
90 struct 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
100 struct audit_aux_data {
101 struct audit_aux_data *next;
102 int type;
103 };
104
105 #define AUDIT_AUX_IPCPERM 0
106
107 struct 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
116 struct audit_aux_data_socketcall {
117 struct audit_aux_data d;
118 int nargs;
119 unsigned long args[0];
120 };
121
122 struct audit_aux_data_sockaddr {
123 struct audit_aux_data d;
124 int len;
125 char a[0];
126 };
127
128 struct audit_aux_data_path {
129 struct audit_aux_data d;
130 struct dentry *dentry;
131 struct vfsmount *mnt;
132 };
133
134 /* The per-task audit context. */
135 struct 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 */
144 long return_code;/* syscall return code */
145 int auditable; /* 1 if record should be written */
146 int name_count;
147 struct audit_names names[AUDIT_NAMES];
148 struct dentry * pwd;
149 struct vfsmount * pwdmnt;
150 struct audit_context *previous; /* For nested syscalls */
151 struct audit_aux_data *aux;
152
153 /* Save things to print about task_struct */
154 pid_t pid;
155 uid_t uid, euid, suid, fsuid;
156 gid_t gid, egid, sgid, fsgid;
157 unsigned long personality;
158 int arch;
159
160 #if AUDIT_DEBUG
161 int put_count;
162 int ino_count;
163 #endif
164 };
165
166 /* Public API */
167 /* There are three lists of rules -- one to search at task creation
168 * time, one to search at syscall entry time, and another to search at
169 * syscall exit time. */
170 static LIST_HEAD(audit_tsklist);
171 static LIST_HEAD(audit_entlist);
172 static LIST_HEAD(audit_extlist);
173
174 struct audit_entry {
175 struct list_head list;
176 struct rcu_head rcu;
177 struct audit_rule rule;
178 };
179
180 extern int audit_pid;
181
182 /* Check to see if two rules are identical. It is called from
183 * audit_del_rule during AUDIT_DEL. */
184 static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b)
185 {
186 int i;
187
188 if (a->flags != b->flags)
189 return 1;
190
191 if (a->action != b->action)
192 return 1;
193
194 if (a->field_count != b->field_count)
195 return 1;
196
197 for (i = 0; i < a->field_count; i++) {
198 if (a->fields[i] != b->fields[i]
199 || a->values[i] != b->values[i])
200 return 1;
201 }
202
203 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
204 if (a->mask[i] != b->mask[i])
205 return 1;
206
207 return 0;
208 }
209
210 /* Note that audit_add_rule and audit_del_rule are called via
211 * audit_receive() in audit.c, and are protected by
212 * audit_netlink_sem. */
213 static inline int audit_add_rule(struct audit_entry *entry,
214 struct list_head *list)
215 {
216 if (entry->rule.flags & AUDIT_PREPEND) {
217 entry->rule.flags &= ~AUDIT_PREPEND;
218 list_add_rcu(&entry->list, list);
219 } else {
220 list_add_tail_rcu(&entry->list, list);
221 }
222 return 0;
223 }
224
225 static void audit_free_rule(struct rcu_head *head)
226 {
227 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
228 kfree(e);
229 }
230
231 /* Note that audit_add_rule and audit_del_rule are called via
232 * audit_receive() in audit.c, and are protected by
233 * audit_netlink_sem. */
234 static inline int audit_del_rule(struct audit_rule *rule,
235 struct list_head *list)
236 {
237 struct audit_entry *e;
238
239 /* Do not use the _rcu iterator here, since this is the only
240 * deletion routine. */
241 list_for_each_entry(e, list, list) {
242 if (!audit_compare_rule(rule, &e->rule)) {
243 list_del_rcu(&e->list);
244 call_rcu(&e->rcu, audit_free_rule);
245 return 0;
246 }
247 }
248 return -EFAULT; /* No matching rule */
249 }
250
251 /* Copy rule from user-space to kernel-space. Called during
252 * AUDIT_ADD. */
253 static int audit_copy_rule(struct audit_rule *d, struct audit_rule *s)
254 {
255 int i;
256
257 if (s->action != AUDIT_NEVER
258 && s->action != AUDIT_POSSIBLE
259 && s->action != AUDIT_ALWAYS)
260 return -1;
261 if (s->field_count < 0 || s->field_count > AUDIT_MAX_FIELDS)
262 return -1;
263
264 d->flags = s->flags;
265 d->action = s->action;
266 d->field_count = s->field_count;
267 for (i = 0; i < d->field_count; i++) {
268 d->fields[i] = s->fields[i];
269 d->values[i] = s->values[i];
270 }
271 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) d->mask[i] = s->mask[i];
272 return 0;
273 }
274
275 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
276 uid_t loginuid)
277 {
278 u32 flags;
279 struct audit_entry *entry;
280 int err = 0;
281
282 switch (type) {
283 case AUDIT_LIST:
284 /* The *_rcu iterators not needed here because we are
285 always called with audit_netlink_sem held. */
286 list_for_each_entry(entry, &audit_tsklist, list)
287 audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
288 &entry->rule, sizeof(entry->rule));
289 list_for_each_entry(entry, &audit_entlist, list)
290 audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
291 &entry->rule, sizeof(entry->rule));
292 list_for_each_entry(entry, &audit_extlist, list)
293 audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
294 &entry->rule, sizeof(entry->rule));
295 audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
296 break;
297 case AUDIT_ADD:
298 if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL)))
299 return -ENOMEM;
300 if (audit_copy_rule(&entry->rule, data)) {
301 kfree(entry);
302 return -EINVAL;
303 }
304 flags = entry->rule.flags;
305 if (!err && (flags & AUDIT_PER_TASK))
306 err = audit_add_rule(entry, &audit_tsklist);
307 if (!err && (flags & AUDIT_AT_ENTRY))
308 err = audit_add_rule(entry, &audit_entlist);
309 if (!err && (flags & AUDIT_AT_EXIT))
310 err = audit_add_rule(entry, &audit_extlist);
311 audit_log(NULL, AUDIT_CONFIG_CHANGE,
312 "auid=%u added an audit rule\n", loginuid);
313 break;
314 case AUDIT_DEL:
315 flags =((struct audit_rule *)data)->flags;
316 if (!err && (flags & AUDIT_PER_TASK))
317 err = audit_del_rule(data, &audit_tsklist);
318 if (!err && (flags & AUDIT_AT_ENTRY))
319 err = audit_del_rule(data, &audit_entlist);
320 if (!err && (flags & AUDIT_AT_EXIT))
321 err = audit_del_rule(data, &audit_extlist);
322 audit_log(NULL, AUDIT_CONFIG_CHANGE,
323 "auid=%u removed an audit rule\n", loginuid);
324 break;
325 default:
326 return -EINVAL;
327 }
328
329 return err;
330 }
331
332 /* Compare a task_struct with an audit_rule. Return 1 on match, 0
333 * otherwise. */
334 static int audit_filter_rules(struct task_struct *tsk,
335 struct audit_rule *rule,
336 struct audit_context *ctx,
337 enum audit_state *state)
338 {
339 int i, j;
340
341 for (i = 0; i < rule->field_count; i++) {
342 u32 field = rule->fields[i] & ~AUDIT_NEGATE;
343 u32 value = rule->values[i];
344 int result = 0;
345
346 switch (field) {
347 case AUDIT_PID:
348 result = (tsk->pid == value);
349 break;
350 case AUDIT_UID:
351 result = (tsk->uid == value);
352 break;
353 case AUDIT_EUID:
354 result = (tsk->euid == value);
355 break;
356 case AUDIT_SUID:
357 result = (tsk->suid == value);
358 break;
359 case AUDIT_FSUID:
360 result = (tsk->fsuid == value);
361 break;
362 case AUDIT_GID:
363 result = (tsk->gid == value);
364 break;
365 case AUDIT_EGID:
366 result = (tsk->egid == value);
367 break;
368 case AUDIT_SGID:
369 result = (tsk->sgid == value);
370 break;
371 case AUDIT_FSGID:
372 result = (tsk->fsgid == value);
373 break;
374 case AUDIT_PERS:
375 result = (tsk->personality == value);
376 break;
377 case AUDIT_ARCH:
378 if (ctx)
379 result = (ctx->arch == value);
380 break;
381
382 case AUDIT_EXIT:
383 if (ctx && ctx->return_valid)
384 result = (ctx->return_code == value);
385 break;
386 case AUDIT_SUCCESS:
387 if (ctx && ctx->return_valid)
388 result = (ctx->return_valid == AUDITSC_SUCCESS);
389 break;
390 case AUDIT_DEVMAJOR:
391 if (ctx) {
392 for (j = 0; j < ctx->name_count; j++) {
393 if (MAJOR(ctx->names[j].dev)==value) {
394 ++result;
395 break;
396 }
397 }
398 }
399 break;
400 case AUDIT_DEVMINOR:
401 if (ctx) {
402 for (j = 0; j < ctx->name_count; j++) {
403 if (MINOR(ctx->names[j].dev)==value) {
404 ++result;
405 break;
406 }
407 }
408 }
409 break;
410 case AUDIT_INODE:
411 if (ctx) {
412 for (j = 0; j < ctx->name_count; j++) {
413 if (ctx->names[j].ino == value) {
414 ++result;
415 break;
416 }
417 }
418 }
419 break;
420 case AUDIT_LOGINUID:
421 result = 0;
422 if (ctx)
423 result = (ctx->loginuid == value);
424 break;
425 case AUDIT_ARG0:
426 case AUDIT_ARG1:
427 case AUDIT_ARG2:
428 case AUDIT_ARG3:
429 if (ctx)
430 result = (ctx->argv[field-AUDIT_ARG0]==value);
431 break;
432 }
433
434 if (rule->fields[i] & AUDIT_NEGATE)
435 result = !result;
436 if (!result)
437 return 0;
438 }
439 switch (rule->action) {
440 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
441 case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break;
442 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
443 }
444 return 1;
445 }
446
447 /* At process creation time, we can determine if system-call auditing is
448 * completely disabled for this task. Since we only have the task
449 * structure at this point, we can only check uid and gid.
450 */
451 static enum audit_state audit_filter_task(struct task_struct *tsk)
452 {
453 struct audit_entry *e;
454 enum audit_state state;
455
456 rcu_read_lock();
457 list_for_each_entry_rcu(e, &audit_tsklist, list) {
458 if (audit_filter_rules(tsk, &e->rule, NULL, &state)) {
459 rcu_read_unlock();
460 return state;
461 }
462 }
463 rcu_read_unlock();
464 return AUDIT_BUILD_CONTEXT;
465 }
466
467 /* At syscall entry and exit time, this filter is called if the
468 * audit_state is not low enough that auditing cannot take place, but is
469 * also not high enough that we already know we have to write an audit
470 * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
471 */
472 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
473 struct audit_context *ctx,
474 struct list_head *list)
475 {
476 struct audit_entry *e;
477 enum audit_state state;
478 int word = AUDIT_WORD(ctx->major);
479 int bit = AUDIT_BIT(ctx->major);
480
481 rcu_read_lock();
482 list_for_each_entry_rcu(e, list, list) {
483 if ((e->rule.mask[word] & bit) == bit
484 && audit_filter_rules(tsk, &e->rule, ctx, &state)) {
485 rcu_read_unlock();
486 return state;
487 }
488 }
489 rcu_read_unlock();
490 return AUDIT_BUILD_CONTEXT;
491 }
492
493 /* This should be called with task_lock() held. */
494 static inline struct audit_context *audit_get_context(struct task_struct *tsk,
495 int return_valid,
496 int return_code)
497 {
498 struct audit_context *context = tsk->audit_context;
499
500 if (likely(!context))
501 return NULL;
502 context->return_valid = return_valid;
503 context->return_code = return_code;
504
505 if (context->in_syscall && !context->auditable) {
506 enum audit_state state;
507 state = audit_filter_syscall(tsk, context, &audit_extlist);
508 if (state == AUDIT_RECORD_CONTEXT)
509 context->auditable = 1;
510 }
511
512 context->pid = tsk->pid;
513 context->uid = tsk->uid;
514 context->gid = tsk->gid;
515 context->euid = tsk->euid;
516 context->suid = tsk->suid;
517 context->fsuid = tsk->fsuid;
518 context->egid = tsk->egid;
519 context->sgid = tsk->sgid;
520 context->fsgid = tsk->fsgid;
521 context->personality = tsk->personality;
522 tsk->audit_context = NULL;
523 return context;
524 }
525
526 static inline void audit_free_names(struct audit_context *context)
527 {
528 int i;
529
530 #if AUDIT_DEBUG == 2
531 if (context->auditable
532 ||context->put_count + context->ino_count != context->name_count) {
533 printk(KERN_ERR "audit.c:%d(:%d): major=%d in_syscall=%d"
534 " name_count=%d put_count=%d"
535 " ino_count=%d [NOT freeing]\n",
536 __LINE__,
537 context->serial, context->major, context->in_syscall,
538 context->name_count, context->put_count,
539 context->ino_count);
540 for (i = 0; i < context->name_count; i++)
541 printk(KERN_ERR "names[%d] = %p = %s\n", i,
542 context->names[i].name,
543 context->names[i].name);
544 dump_stack();
545 return;
546 }
547 #endif
548 #if AUDIT_DEBUG
549 context->put_count = 0;
550 context->ino_count = 0;
551 #endif
552
553 for (i = 0; i < context->name_count; i++)
554 if (context->names[i].name)
555 __putname(context->names[i].name);
556 context->name_count = 0;
557 if (context->pwd)
558 dput(context->pwd);
559 if (context->pwdmnt)
560 mntput(context->pwdmnt);
561 context->pwd = NULL;
562 context->pwdmnt = NULL;
563 }
564
565 static inline void audit_free_aux(struct audit_context *context)
566 {
567 struct audit_aux_data *aux;
568
569 while ((aux = context->aux)) {
570 if (aux->type == AUDIT_AVC_PATH) {
571 struct audit_aux_data_path *axi = (void *)aux;
572 dput(axi->dentry);
573 mntput(axi->mnt);
574 }
575 context->aux = aux->next;
576 kfree(aux);
577 }
578 }
579
580 static inline void audit_zero_context(struct audit_context *context,
581 enum audit_state state)
582 {
583 uid_t loginuid = context->loginuid;
584
585 memset(context, 0, sizeof(*context));
586 context->state = state;
587 context->loginuid = loginuid;
588 }
589
590 static inline struct audit_context *audit_alloc_context(enum audit_state state)
591 {
592 struct audit_context *context;
593
594 if (!(context = kmalloc(sizeof(*context), GFP_KERNEL)))
595 return NULL;
596 audit_zero_context(context, state);
597 return context;
598 }
599
600 /* Filter on the task information and allocate a per-task audit context
601 * if necessary. Doing so turns on system call auditing for the
602 * specified task. This is called from copy_process, so no lock is
603 * needed. */
604 int audit_alloc(struct task_struct *tsk)
605 {
606 struct audit_context *context;
607 enum audit_state state;
608
609 if (likely(!audit_enabled))
610 return 0; /* Return if not auditing. */
611
612 state = audit_filter_task(tsk);
613 if (likely(state == AUDIT_DISABLED))
614 return 0;
615
616 if (!(context = audit_alloc_context(state))) {
617 audit_log_lost("out of memory in audit_alloc");
618 return -ENOMEM;
619 }
620
621 /* Preserve login uid */
622 context->loginuid = -1;
623 if (current->audit_context)
624 context->loginuid = current->audit_context->loginuid;
625
626 tsk->audit_context = context;
627 set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
628 return 0;
629 }
630
631 static inline void audit_free_context(struct audit_context *context)
632 {
633 struct audit_context *previous;
634 int count = 0;
635
636 do {
637 previous = context->previous;
638 if (previous || (count && count < 10)) {
639 ++count;
640 printk(KERN_ERR "audit(:%d): major=%d name_count=%d:"
641 " freeing multiple contexts (%d)\n",
642 context->serial, context->major,
643 context->name_count, count);
644 }
645 audit_free_names(context);
646 audit_free_aux(context);
647 kfree(context);
648 context = previous;
649 } while (context);
650 if (count >= 10)
651 printk(KERN_ERR "audit: freed %d contexts\n", count);
652 }
653
654 static void audit_log_task_info(struct audit_buffer *ab)
655 {
656 char name[sizeof(current->comm)];
657 struct mm_struct *mm = current->mm;
658 struct vm_area_struct *vma;
659
660 get_task_comm(name, current);
661 audit_log_format(ab, " comm=");
662 audit_log_untrustedstring(ab, name);
663
664 if (!mm)
665 return;
666
667 down_read(&mm->mmap_sem);
668 vma = mm->mmap;
669 while (vma) {
670 if ((vma->vm_flags & VM_EXECUTABLE) &&
671 vma->vm_file) {
672 audit_log_d_path(ab, "exe=",
673 vma->vm_file->f_dentry,
674 vma->vm_file->f_vfsmnt);
675 break;
676 }
677 vma = vma->vm_next;
678 }
679 up_read(&mm->mmap_sem);
680 }
681
682 static void audit_log_exit(struct audit_context *context)
683 {
684 int i;
685 struct audit_buffer *ab;
686 struct audit_aux_data *aux;
687
688 ab = audit_log_start(context, AUDIT_SYSCALL);
689 if (!ab)
690 return; /* audit_panic has been called */
691 audit_log_format(ab, "arch=%x syscall=%d",
692 context->arch, context->major);
693 if (context->personality != PER_LINUX)
694 audit_log_format(ab, " per=%lx", context->personality);
695 if (context->return_valid)
696 audit_log_format(ab, " success=%s exit=%ld",
697 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
698 context->return_code);
699 audit_log_format(ab,
700 " a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
701 " pid=%d auid=%u uid=%u gid=%u"
702 " euid=%u suid=%u fsuid=%u"
703 " egid=%u sgid=%u fsgid=%u",
704 context->argv[0],
705 context->argv[1],
706 context->argv[2],
707 context->argv[3],
708 context->name_count,
709 context->pid,
710 context->loginuid,
711 context->uid,
712 context->gid,
713 context->euid, context->suid, context->fsuid,
714 context->egid, context->sgid, context->fsgid);
715 audit_log_task_info(ab);
716 audit_log_end(ab);
717
718 for (aux = context->aux; aux; aux = aux->next) {
719
720 ab = audit_log_start(context, aux->type);
721 if (!ab)
722 continue; /* audit_panic has been called */
723
724 switch (aux->type) {
725 case AUDIT_IPC: {
726 struct audit_aux_data_ipcctl *axi = (void *)aux;
727 audit_log_format(ab,
728 " qbytes=%lx iuid=%u igid=%u mode=%x",
729 axi->qbytes, axi->uid, axi->gid, axi->mode);
730 break; }
731
732 case AUDIT_SOCKETCALL: {
733 int i;
734 struct audit_aux_data_socketcall *axs = (void *)aux;
735 audit_log_format(ab, "nargs=%d", axs->nargs);
736 for (i=0; i<axs->nargs; i++)
737 audit_log_format(ab, " a%d=%lx", i, axs->args[i]);
738 break; }
739
740 case AUDIT_SOCKADDR: {
741 struct audit_aux_data_sockaddr *axs = (void *)aux;
742
743 audit_log_format(ab, "saddr=");
744 audit_log_hex(ab, axs->a, axs->len);
745 break; }
746
747 case AUDIT_AVC_PATH: {
748 struct audit_aux_data_path *axi = (void *)aux;
749 audit_log_d_path(ab, "path=", axi->dentry, axi->mnt);
750 break; }
751
752 }
753 audit_log_end(ab);
754 }
755
756 if (context->pwd && context->pwdmnt) {
757 ab = audit_log_start(context, AUDIT_CWD);
758 if (ab) {
759 audit_log_d_path(ab, "cwd=", context->pwd, context->pwdmnt);
760 audit_log_end(ab);
761 }
762 }
763 for (i = 0; i < context->name_count; i++) {
764 ab = audit_log_start(context, AUDIT_PATH);
765 if (!ab)
766 continue; /* audit_panic has been called */
767
768 audit_log_format(ab, "item=%d", i);
769 if (context->names[i].name) {
770 audit_log_format(ab, " name=");
771 audit_log_untrustedstring(ab, context->names[i].name);
772 }
773 if (context->names[i].ino != (unsigned long)-1)
774 audit_log_format(ab, " inode=%lu dev=%02x:%02x mode=%#o"
775 " ouid=%u ogid=%u rdev=%02x:%02x",
776 context->names[i].ino,
777 MAJOR(context->names[i].dev),
778 MINOR(context->names[i].dev),
779 context->names[i].mode,
780 context->names[i].uid,
781 context->names[i].gid,
782 MAJOR(context->names[i].rdev),
783 MINOR(context->names[i].rdev));
784 audit_log_end(ab);
785 }
786 }
787
788 /* Free a per-task audit context. Called from copy_process and
789 * __put_task_struct. */
790 void audit_free(struct task_struct *tsk)
791 {
792 struct audit_context *context;
793
794 task_lock(tsk);
795 context = audit_get_context(tsk, 0, 0);
796 task_unlock(tsk);
797
798 if (likely(!context))
799 return;
800
801 /* Check for system calls that do not go through the exit
802 * function (e.g., exit_group), then free context block. */
803 if (context->in_syscall && context->auditable && context->pid != audit_pid)
804 audit_log_exit(context);
805
806 audit_free_context(context);
807 }
808
809 /* Fill in audit context at syscall entry. This only happens if the
810 * audit context was created when the task was created and the state or
811 * filters demand the audit context be built. If the state from the
812 * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
813 * then the record will be written at syscall exit time (otherwise, it
814 * will only be written if another part of the kernel requests that it
815 * be written). */
816 void audit_syscall_entry(struct task_struct *tsk, int arch, int major,
817 unsigned long a1, unsigned long a2,
818 unsigned long a3, unsigned long a4)
819 {
820 struct audit_context *context = tsk->audit_context;
821 enum audit_state state;
822
823 BUG_ON(!context);
824
825 /* This happens only on certain architectures that make system
826 * calls in kernel_thread via the entry.S interface, instead of
827 * with direct calls. (If you are porting to a new
828 * architecture, hitting this condition can indicate that you
829 * got the _exit/_leave calls backward in entry.S.)
830 *
831 * i386 no
832 * x86_64 no
833 * ppc64 yes (see arch/ppc64/kernel/misc.S)
834 *
835 * This also happens with vm86 emulation in a non-nested manner
836 * (entries without exits), so this case must be caught.
837 */
838 if (context->in_syscall) {
839 struct audit_context *newctx;
840
841 #if defined(__NR_vm86) && defined(__NR_vm86old)
842 /* vm86 mode should only be entered once */
843 if (major == __NR_vm86 || major == __NR_vm86old)
844 return;
845 #endif
846 #if AUDIT_DEBUG
847 printk(KERN_ERR
848 "audit(:%d) pid=%d in syscall=%d;"
849 " entering syscall=%d\n",
850 context->serial, tsk->pid, context->major, major);
851 #endif
852 newctx = audit_alloc_context(context->state);
853 if (newctx) {
854 newctx->previous = context;
855 context = newctx;
856 tsk->audit_context = newctx;
857 } else {
858 /* If we can't alloc a new context, the best we
859 * can do is to leak memory (any pending putname
860 * will be lost). The only other alternative is
861 * to abandon auditing. */
862 audit_zero_context(context, context->state);
863 }
864 }
865 BUG_ON(context->in_syscall || context->name_count);
866
867 if (!audit_enabled)
868 return;
869
870 context->arch = arch;
871 context->major = major;
872 context->argv[0] = a1;
873 context->argv[1] = a2;
874 context->argv[2] = a3;
875 context->argv[3] = a4;
876
877 state = context->state;
878 if (state == AUDIT_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT)
879 state = audit_filter_syscall(tsk, context, &audit_entlist);
880 if (likely(state == AUDIT_DISABLED))
881 return;
882
883 context->serial = audit_serial();
884 context->ctime = CURRENT_TIME;
885 context->in_syscall = 1;
886 context->auditable = !!(state == AUDIT_RECORD_CONTEXT);
887 }
888
889 /* Tear down after system call. If the audit context has been marked as
890 * auditable (either because of the AUDIT_RECORD_CONTEXT state from
891 * filtering, or because some other part of the kernel write an audit
892 * message), then write out the syscall information. In call cases,
893 * free the names stored from getname(). */
894 void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code)
895 {
896 struct audit_context *context;
897
898 get_task_struct(tsk);
899 task_lock(tsk);
900 context = audit_get_context(tsk, valid, return_code);
901 task_unlock(tsk);
902
903 /* Not having a context here is ok, since the parent may have
904 * called __put_task_struct. */
905 if (likely(!context))
906 return;
907
908 if (context->in_syscall && context->auditable && context->pid != audit_pid)
909 audit_log_exit(context);
910
911 context->in_syscall = 0;
912 context->auditable = 0;
913
914 if (context->previous) {
915 struct audit_context *new_context = context->previous;
916 context->previous = NULL;
917 audit_free_context(context);
918 tsk->audit_context = new_context;
919 } else {
920 audit_free_names(context);
921 audit_free_aux(context);
922 audit_zero_context(context, context->state);
923 tsk->audit_context = context;
924 }
925 put_task_struct(tsk);
926 }
927
928 /* Add a name to the list. Called from fs/namei.c:getname(). */
929 void audit_getname(const char *name)
930 {
931 struct audit_context *context = current->audit_context;
932
933 if (!context || IS_ERR(name) || !name)
934 return;
935
936 if (!context->in_syscall) {
937 #if AUDIT_DEBUG == 2
938 printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)\n",
939 __FILE__, __LINE__, context->serial, name);
940 dump_stack();
941 #endif
942 return;
943 }
944 BUG_ON(context->name_count >= AUDIT_NAMES);
945 context->names[context->name_count].name = name;
946 context->names[context->name_count].ino = (unsigned long)-1;
947 ++context->name_count;
948 if (!context->pwd) {
949 read_lock(&current->fs->lock);
950 context->pwd = dget(current->fs->pwd);
951 context->pwdmnt = mntget(current->fs->pwdmnt);
952 read_unlock(&current->fs->lock);
953 }
954
955 }
956
957 /* Intercept a putname request. Called from
958 * include/linux/fs.h:putname(). If we have stored the name from
959 * getname in the audit context, then we delay the putname until syscall
960 * exit. */
961 void audit_putname(const char *name)
962 {
963 struct audit_context *context = current->audit_context;
964
965 BUG_ON(!context);
966 if (!context->in_syscall) {
967 #if AUDIT_DEBUG == 2
968 printk(KERN_ERR "%s:%d(:%d): __putname(%p)\n",
969 __FILE__, __LINE__, context->serial, name);
970 if (context->name_count) {
971 int i;
972 for (i = 0; i < context->name_count; i++)
973 printk(KERN_ERR "name[%d] = %p = %s\n", i,
974 context->names[i].name,
975 context->names[i].name);
976 }
977 #endif
978 __putname(name);
979 }
980 #if AUDIT_DEBUG
981 else {
982 ++context->put_count;
983 if (context->put_count > context->name_count) {
984 printk(KERN_ERR "%s:%d(:%d): major=%d"
985 " in_syscall=%d putname(%p) name_count=%d"
986 " put_count=%d\n",
987 __FILE__, __LINE__,
988 context->serial, context->major,
989 context->in_syscall, name, context->name_count,
990 context->put_count);
991 dump_stack();
992 }
993 }
994 #endif
995 }
996
997 /* Store the inode and device from a lookup. Called from
998 * fs/namei.c:path_lookup(). */
999 void audit_inode(const char *name, const struct inode *inode)
1000 {
1001 int idx;
1002 struct audit_context *context = current->audit_context;
1003
1004 if (!context->in_syscall)
1005 return;
1006 if (context->name_count
1007 && context->names[context->name_count-1].name
1008 && context->names[context->name_count-1].name == name)
1009 idx = context->name_count - 1;
1010 else if (context->name_count > 1
1011 && context->names[context->name_count-2].name
1012 && context->names[context->name_count-2].name == name)
1013 idx = context->name_count - 2;
1014 else {
1015 /* FIXME: how much do we care about inodes that have no
1016 * associated name? */
1017 if (context->name_count >= AUDIT_NAMES - AUDIT_NAMES_RESERVED)
1018 return;
1019 idx = context->name_count++;
1020 context->names[idx].name = NULL;
1021 #if AUDIT_DEBUG
1022 ++context->ino_count;
1023 #endif
1024 }
1025 context->names[idx].ino = inode->i_ino;
1026 context->names[idx].dev = inode->i_sb->s_dev;
1027 context->names[idx].mode = inode->i_mode;
1028 context->names[idx].uid = inode->i_uid;
1029 context->names[idx].gid = inode->i_gid;
1030 context->names[idx].rdev = inode->i_rdev;
1031 }
1032
1033 void auditsc_get_stamp(struct audit_context *ctx,
1034 struct timespec *t, unsigned int *serial)
1035 {
1036 t->tv_sec = ctx->ctime.tv_sec;
1037 t->tv_nsec = ctx->ctime.tv_nsec;
1038 *serial = ctx->serial;
1039 ctx->auditable = 1;
1040 }
1041
1042 int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
1043 {
1044 if (task->audit_context) {
1045 struct audit_buffer *ab;
1046
1047 ab = audit_log_start(NULL, AUDIT_LOGIN);
1048 if (ab) {
1049 audit_log_format(ab, "login pid=%d uid=%u "
1050 "old auid=%u new auid=%u",
1051 task->pid, task->uid,
1052 task->audit_context->loginuid, loginuid);
1053 audit_log_end(ab);
1054 }
1055 task->audit_context->loginuid = loginuid;
1056 }
1057 return 0;
1058 }
1059
1060 uid_t audit_get_loginuid(struct audit_context *ctx)
1061 {
1062 return ctx ? ctx->loginuid : -1;
1063 }
1064
1065 int audit_ipc_perms(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
1066 {
1067 struct audit_aux_data_ipcctl *ax;
1068 struct audit_context *context = current->audit_context;
1069
1070 if (likely(!context))
1071 return 0;
1072
1073 ax = kmalloc(sizeof(*ax), GFP_KERNEL);
1074 if (!ax)
1075 return -ENOMEM;
1076
1077 ax->qbytes = qbytes;
1078 ax->uid = uid;
1079 ax->gid = gid;
1080 ax->mode = mode;
1081
1082 ax->d.type = AUDIT_IPC;
1083 ax->d.next = context->aux;
1084 context->aux = (void *)ax;
1085 return 0;
1086 }
1087
1088 int audit_socketcall(int nargs, unsigned long *args)
1089 {
1090 struct audit_aux_data_socketcall *ax;
1091 struct audit_context *context = current->audit_context;
1092
1093 if (likely(!context))
1094 return 0;
1095
1096 ax = kmalloc(sizeof(*ax) + nargs * sizeof(unsigned long), GFP_KERNEL);
1097 if (!ax)
1098 return -ENOMEM;
1099
1100 ax->nargs = nargs;
1101 memcpy(ax->args, args, nargs * sizeof(unsigned long));
1102
1103 ax->d.type = AUDIT_SOCKETCALL;
1104 ax->d.next = context->aux;
1105 context->aux = (void *)ax;
1106 return 0;
1107 }
1108
1109 int audit_sockaddr(int len, void *a)
1110 {
1111 struct audit_aux_data_sockaddr *ax;
1112 struct audit_context *context = current->audit_context;
1113
1114 if (likely(!context))
1115 return 0;
1116
1117 ax = kmalloc(sizeof(*ax) + len, GFP_KERNEL);
1118 if (!ax)
1119 return -ENOMEM;
1120
1121 ax->len = len;
1122 memcpy(ax->a, a, len);
1123
1124 ax->d.type = AUDIT_SOCKADDR;
1125 ax->d.next = context->aux;
1126 context->aux = (void *)ax;
1127 return 0;
1128 }
1129
1130 int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
1131 {
1132 struct audit_aux_data_path *ax;
1133 struct audit_context *context = current->audit_context;
1134
1135 if (likely(!context))
1136 return 0;
1137
1138 ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1139 if (!ax)
1140 return -ENOMEM;
1141
1142 ax->dentry = dget(dentry);
1143 ax->mnt = mntget(mnt);
1144
1145 ax->d.type = AUDIT_AVC_PATH;
1146 ax->d.next = context->aux;
1147 context->aux = (void *)ax;
1148 return 0;
1149 }
1150
1151 void audit_signal_info(int sig, struct task_struct *t)
1152 {
1153 extern pid_t audit_sig_pid;
1154 extern uid_t audit_sig_uid;
1155
1156 if (unlikely(audit_pid && t->pid == audit_pid)) {
1157 if (sig == SIGTERM || sig == SIGHUP) {
1158 struct audit_context *ctx = current->audit_context;
1159 audit_sig_pid = current->pid;
1160 if (ctx)
1161 audit_sig_uid = ctx->loginuid;
1162 else
1163 audit_sig_uid = current->uid;
1164 }
1165 }
1166 }
1167
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