AUDIT: Escape comm when logging task info
[linux-2.6/linux-loongson.git] / kernel / auditsc.c
blobb45677eba78fc61f7b8277cc07f6b12ae42fd356
1 /* auditsc.c -- System-call auditing support
2 * Handles all system-call specific auditing features.
4 * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
5 * All Rights Reserved.
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.
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.
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
21 * Written by Rickard E. (Rik) Faith <faith@redhat.com>
23 * Many of the ideas implemented here are from Stephen C. Tweedie,
24 * especially the idea of avoiding a copy by using getname.
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.
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>
44 /* 0 = no checking
45 1 = put_count checking
46 2 = verbose put_count checking
48 #define AUDIT_DEBUG 0
50 /* No syscall auditing will take place unless audit_enabled != 0. */
51 extern int audit_enabled;
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
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
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. */
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).
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;
100 struct audit_aux_data {
101 struct audit_aux_data *next;
102 int type;
105 #define AUDIT_AUX_IPCPERM 0
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;
116 struct audit_aux_data_socketcall {
117 struct audit_aux_data d;
118 int nargs;
119 unsigned long args[0];
122 struct audit_aux_data_sockaddr {
123 struct audit_aux_data d;
124 int len;
125 char a[0];
128 struct audit_aux_data_path {
129 struct audit_aux_data d;
130 struct dentry *dentry;
131 struct vfsmount *mnt;
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 audit_context *previous; /* For nested syscalls */
149 struct audit_aux_data *aux;
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;
156 int arch;
158 #if AUDIT_DEBUG
159 int put_count;
160 int ino_count;
161 #endif
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. */
168 static LIST_HEAD(audit_tsklist);
169 static LIST_HEAD(audit_entlist);
170 static LIST_HEAD(audit_extlist);
172 struct audit_entry {
173 struct list_head list;
174 struct rcu_head rcu;
175 struct audit_rule rule;
178 extern int audit_pid;
180 /* Check to see if two rules are identical. It is called from
181 * audit_del_rule during AUDIT_DEL. */
182 static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b)
184 int i;
186 if (a->flags != b->flags)
187 return 1;
189 if (a->action != b->action)
190 return 1;
192 if (a->field_count != b->field_count)
193 return 1;
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;
201 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
202 if (a->mask[i] != b->mask[i])
203 return 1;
205 return 0;
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. */
211 static inline int audit_add_rule(struct audit_entry *entry,
212 struct list_head *list)
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);
220 return 0;
223 static void audit_free_rule(struct rcu_head *head)
225 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
226 kfree(e);
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. */
232 static inline int audit_del_rule(struct audit_rule *rule,
233 struct list_head *list)
235 struct audit_entry *e;
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;
246 return -EFAULT; /* No matching rule */
249 /* Copy rule from user-space to kernel-space. Called during
250 * AUDIT_ADD. */
251 static int audit_copy_rule(struct audit_rule *d, struct audit_rule *s)
253 int i;
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;
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];
269 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) d->mask[i] = s->mask[i];
270 return 0;
273 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
274 uid_t loginuid)
276 u32 flags;
277 struct audit_entry *entry;
278 int err = 0;
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;
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);
309 audit_log(NULL, AUDIT_CONFIG_CHANGE,
310 "auid=%u added an audit rule\n", loginuid);
311 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);
320 audit_log(NULL, AUDIT_CONFIG_CHANGE,
321 "auid=%u removed an audit rule\n", loginuid);
322 break;
323 default:
324 return -EINVAL;
327 return err;
330 /* Compare a task_struct with an audit_rule. Return 1 on match, 0
331 * otherwise. */
332 static int audit_filter_rules(struct task_struct *tsk,
333 struct audit_rule *rule,
334 struct audit_context *ctx,
335 enum audit_state *state)
337 int i, j;
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;
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;
375 case AUDIT_ARCH:
376 if (ctx)
377 result = (ctx->arch == value);
378 break;
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)
386 result = (ctx->return_valid == AUDITSC_SUCCESS);
387 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;
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;
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;
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;
432 if (rule->fields[i] & AUDIT_NEGATE)
433 result = !result;
434 if (!result)
435 return 0;
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;
442 return 1;
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.
449 static enum audit_state audit_filter_task(struct task_struct *tsk)
451 struct audit_entry *e;
452 enum audit_state state;
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;
461 rcu_read_unlock();
462 return AUDIT_BUILD_CONTEXT;
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
467 * also not high enough that we already know we have to write an audit
468 * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
470 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
471 struct audit_context *ctx,
472 struct list_head *list)
474 struct audit_entry *e;
475 enum audit_state state;
476 int word = AUDIT_WORD(ctx->major);
477 int bit = AUDIT_BIT(ctx->major);
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;
487 rcu_read_unlock();
488 return AUDIT_BUILD_CONTEXT;
491 /* This should be called with task_lock() held. */
492 static inline struct audit_context *audit_get_context(struct task_struct *tsk,
493 int return_valid,
494 int return_code)
496 struct audit_context *context = tsk->audit_context;
498 if (likely(!context))
499 return NULL;
500 context->return_valid = return_valid;
501 context->return_code = return_code;
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;
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;
524 static inline void audit_free_names(struct audit_context *context)
526 int i;
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;
545 #endif
546 #if AUDIT_DEBUG
547 context->put_count = 0;
548 context->ino_count = 0;
549 #endif
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;
557 static inline void audit_free_aux(struct audit_context *context)
559 struct audit_aux_data *aux;
561 while ((aux = context->aux)) {
562 if (aux->type == AUDIT_AVC_PATH) {
563 struct audit_aux_data_path *axi = (void *)aux;
564 dput(axi->dentry);
565 mntput(axi->mnt);
567 context->aux = aux->next;
568 kfree(aux);
572 static inline void audit_zero_context(struct audit_context *context,
573 enum audit_state state)
575 uid_t loginuid = context->loginuid;
577 memset(context, 0, sizeof(*context));
578 context->state = state;
579 context->loginuid = loginuid;
582 static inline struct audit_context *audit_alloc_context(enum audit_state state)
584 struct audit_context *context;
586 if (!(context = kmalloc(sizeof(*context), GFP_KERNEL)))
587 return NULL;
588 audit_zero_context(context, state);
589 return context;
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. */
596 int audit_alloc(struct task_struct *tsk)
598 struct audit_context *context;
599 enum audit_state state;
601 if (likely(!audit_enabled))
602 return 0; /* Return if not auditing. */
604 state = audit_filter_task(tsk);
605 if (likely(state == AUDIT_DISABLED))
606 return 0;
608 if (!(context = audit_alloc_context(state))) {
609 audit_log_lost("out of memory in audit_alloc");
610 return -ENOMEM;
613 /* Preserve login uid */
614 context->loginuid = -1;
615 if (current->audit_context)
616 context->loginuid = current->audit_context->loginuid;
618 tsk->audit_context = context;
619 set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
620 return 0;
623 static inline void audit_free_context(struct audit_context *context)
625 struct audit_context *previous;
626 int count = 0;
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);
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);
646 static void audit_log_task_info(struct audit_buffer *ab)
648 char name[sizeof(current->comm)];
649 struct mm_struct *mm = current->mm;
650 struct vm_area_struct *vma;
652 get_task_comm(name, current);
653 audit_log_format(ab, " comm=");
654 audit_log_untrustedstring(ab, name);
656 if (!mm)
657 return;
659 down_read(&mm->mmap_sem);
660 vma = mm->mmap;
661 while (vma) {
662 if ((vma->vm_flags & VM_EXECUTABLE) &&
663 vma->vm_file) {
664 audit_log_d_path(ab, "exe=",
665 vma->vm_file->f_dentry,
666 vma->vm_file->f_vfsmnt);
667 break;
669 vma = vma->vm_next;
671 up_read(&mm->mmap_sem);
674 static void audit_log_exit(struct audit_context *context)
676 int i;
677 struct audit_buffer *ab;
679 ab = audit_log_start(context, AUDIT_SYSCALL);
680 if (!ab)
681 return; /* audit_panic has been called */
682 audit_log_format(ab, "arch=%x syscall=%d",
683 context->arch, context->major);
684 if (context->personality != PER_LINUX)
685 audit_log_format(ab, " per=%lx", context->personality);
686 if (context->return_valid)
687 audit_log_format(ab, " success=%s exit=%ld",
688 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
689 context->return_code);
690 audit_log_format(ab,
691 " a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
692 " pid=%d auid=%u uid=%u gid=%u"
693 " euid=%u suid=%u fsuid=%u"
694 " egid=%u sgid=%u fsgid=%u",
695 context->argv[0],
696 context->argv[1],
697 context->argv[2],
698 context->argv[3],
699 context->name_count,
700 context->pid,
701 context->loginuid,
702 context->uid,
703 context->gid,
704 context->euid, context->suid, context->fsuid,
705 context->egid, context->sgid, context->fsgid);
706 audit_log_task_info(ab);
707 audit_log_end(ab);
708 while (context->aux) {
709 struct audit_aux_data *aux;
711 aux = context->aux;
713 ab = audit_log_start(context, aux->type);
714 if (!ab)
715 continue; /* audit_panic has been called */
717 switch (aux->type) {
718 case AUDIT_IPC: {
719 struct audit_aux_data_ipcctl *axi = (void *)aux;
720 audit_log_format(ab,
721 " qbytes=%lx iuid=%u igid=%u mode=%x",
722 axi->qbytes, axi->uid, axi->gid, axi->mode);
723 break; }
725 case AUDIT_SOCKETCALL: {
726 int i;
727 struct audit_aux_data_socketcall *axs = (void *)aux;
728 audit_log_format(ab, "nargs=%d", axs->nargs);
729 for (i=0; i<axs->nargs; i++)
730 audit_log_format(ab, " a%d=%lx", i, axs->args[i]);
731 break; }
733 case AUDIT_SOCKADDR: {
734 struct audit_aux_data_sockaddr *axs = (void *)aux;
736 audit_log_format(ab, "saddr=");
737 audit_log_hex(ab, axs->a, axs->len);
738 break; }
740 case AUDIT_AVC_PATH: {
741 struct audit_aux_data_path *axi = (void *)aux;
742 audit_log_d_path(ab, "path=", axi->dentry, axi->mnt);
743 dput(axi->dentry);
744 mntput(axi->mnt);
745 break; }
748 audit_log_end(ab);
750 context->aux = aux->next;
751 kfree(aux);
754 for (i = 0; i < context->name_count; i++) {
755 ab = audit_log_start(context, AUDIT_PATH);
756 if (!ab)
757 continue; /* audit_panic has been called */
758 audit_log_format(ab, "item=%d", i);
759 if (context->names[i].name) {
760 audit_log_format(ab, " name=");
761 audit_log_untrustedstring(ab, context->names[i].name);
763 if (context->names[i].ino != (unsigned long)-1)
764 audit_log_format(ab, " inode=%lu dev=%02x:%02x mode=%#o"
765 " ouid=%u ogid=%u rdev=%02x:%02x",
766 context->names[i].ino,
767 MAJOR(context->names[i].dev),
768 MINOR(context->names[i].dev),
769 context->names[i].mode,
770 context->names[i].uid,
771 context->names[i].gid,
772 MAJOR(context->names[i].rdev),
773 MINOR(context->names[i].rdev));
774 audit_log_end(ab);
778 /* Free a per-task audit context. Called from copy_process and
779 * __put_task_struct. */
780 void audit_free(struct task_struct *tsk)
782 struct audit_context *context;
784 task_lock(tsk);
785 context = audit_get_context(tsk, 0, 0);
786 task_unlock(tsk);
788 if (likely(!context))
789 return;
791 /* Check for system calls that do not go through the exit
792 * function (e.g., exit_group), then free context block. */
793 if (context->in_syscall && context->auditable && context->pid != audit_pid)
794 audit_log_exit(context);
796 audit_free_context(context);
799 /* Fill in audit context at syscall entry. This only happens if the
800 * audit context was created when the task was created and the state or
801 * filters demand the audit context be built. If the state from the
802 * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
803 * then the record will be written at syscall exit time (otherwise, it
804 * will only be written if another part of the kernel requests that it
805 * be written). */
806 void audit_syscall_entry(struct task_struct *tsk, int arch, int major,
807 unsigned long a1, unsigned long a2,
808 unsigned long a3, unsigned long a4)
810 struct audit_context *context = tsk->audit_context;
811 enum audit_state state;
813 BUG_ON(!context);
815 /* This happens only on certain architectures that make system
816 * calls in kernel_thread via the entry.S interface, instead of
817 * with direct calls. (If you are porting to a new
818 * architecture, hitting this condition can indicate that you
819 * got the _exit/_leave calls backward in entry.S.)
821 * i386 no
822 * x86_64 no
823 * ppc64 yes (see arch/ppc64/kernel/misc.S)
825 * This also happens with vm86 emulation in a non-nested manner
826 * (entries without exits), so this case must be caught.
828 if (context->in_syscall) {
829 struct audit_context *newctx;
831 #if defined(__NR_vm86) && defined(__NR_vm86old)
832 /* vm86 mode should only be entered once */
833 if (major == __NR_vm86 || major == __NR_vm86old)
834 return;
835 #endif
836 #if AUDIT_DEBUG
837 printk(KERN_ERR
838 "audit(:%d) pid=%d in syscall=%d;"
839 " entering syscall=%d\n",
840 context->serial, tsk->pid, context->major, major);
841 #endif
842 newctx = audit_alloc_context(context->state);
843 if (newctx) {
844 newctx->previous = context;
845 context = newctx;
846 tsk->audit_context = newctx;
847 } else {
848 /* If we can't alloc a new context, the best we
849 * can do is to leak memory (any pending putname
850 * will be lost). The only other alternative is
851 * to abandon auditing. */
852 audit_zero_context(context, context->state);
855 BUG_ON(context->in_syscall || context->name_count);
857 if (!audit_enabled)
858 return;
860 context->arch = arch;
861 context->major = major;
862 context->argv[0] = a1;
863 context->argv[1] = a2;
864 context->argv[2] = a3;
865 context->argv[3] = a4;
867 state = context->state;
868 if (state == AUDIT_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT)
869 state = audit_filter_syscall(tsk, context, &audit_entlist);
870 if (likely(state == AUDIT_DISABLED))
871 return;
873 context->serial = audit_serial();
874 context->ctime = CURRENT_TIME;
875 context->in_syscall = 1;
876 context->auditable = !!(state == AUDIT_RECORD_CONTEXT);
879 /* Tear down after system call. If the audit context has been marked as
880 * auditable (either because of the AUDIT_RECORD_CONTEXT state from
881 * filtering, or because some other part of the kernel write an audit
882 * message), then write out the syscall information. In call cases,
883 * free the names stored from getname(). */
884 void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code)
886 struct audit_context *context;
888 get_task_struct(tsk);
889 task_lock(tsk);
890 context = audit_get_context(tsk, valid, return_code);
891 task_unlock(tsk);
893 /* Not having a context here is ok, since the parent may have
894 * called __put_task_struct. */
895 if (likely(!context))
896 return;
898 if (context->in_syscall && context->auditable && context->pid != audit_pid)
899 audit_log_exit(context);
901 context->in_syscall = 0;
902 context->auditable = 0;
904 if (context->previous) {
905 struct audit_context *new_context = context->previous;
906 context->previous = NULL;
907 audit_free_context(context);
908 tsk->audit_context = new_context;
909 } else {
910 audit_free_names(context);
911 audit_free_aux(context);
912 audit_zero_context(context, context->state);
913 tsk->audit_context = context;
915 put_task_struct(tsk);
918 /* Add a name to the list. Called from fs/namei.c:getname(). */
919 void audit_getname(const char *name)
921 struct audit_context *context = current->audit_context;
923 if (!context || IS_ERR(name) || !name)
924 return;
926 if (!context->in_syscall) {
927 #if AUDIT_DEBUG == 2
928 printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)\n",
929 __FILE__, __LINE__, context->serial, name);
930 dump_stack();
931 #endif
932 return;
934 BUG_ON(context->name_count >= AUDIT_NAMES);
935 context->names[context->name_count].name = name;
936 context->names[context->name_count].ino = (unsigned long)-1;
937 ++context->name_count;
940 /* Intercept a putname request. Called from
941 * include/linux/fs.h:putname(). If we have stored the name from
942 * getname in the audit context, then we delay the putname until syscall
943 * exit. */
944 void audit_putname(const char *name)
946 struct audit_context *context = current->audit_context;
948 BUG_ON(!context);
949 if (!context->in_syscall) {
950 #if AUDIT_DEBUG == 2
951 printk(KERN_ERR "%s:%d(:%d): __putname(%p)\n",
952 __FILE__, __LINE__, context->serial, name);
953 if (context->name_count) {
954 int i;
955 for (i = 0; i < context->name_count; i++)
956 printk(KERN_ERR "name[%d] = %p = %s\n", i,
957 context->names[i].name,
958 context->names[i].name);
960 #endif
961 __putname(name);
963 #if AUDIT_DEBUG
964 else {
965 ++context->put_count;
966 if (context->put_count > context->name_count) {
967 printk(KERN_ERR "%s:%d(:%d): major=%d"
968 " in_syscall=%d putname(%p) name_count=%d"
969 " put_count=%d\n",
970 __FILE__, __LINE__,
971 context->serial, context->major,
972 context->in_syscall, name, context->name_count,
973 context->put_count);
974 dump_stack();
977 #endif
980 /* Store the inode and device from a lookup. Called from
981 * fs/namei.c:path_lookup(). */
982 void audit_inode(const char *name, const struct inode *inode)
984 int idx;
985 struct audit_context *context = current->audit_context;
987 if (!context->in_syscall)
988 return;
989 if (context->name_count
990 && context->names[context->name_count-1].name
991 && context->names[context->name_count-1].name == name)
992 idx = context->name_count - 1;
993 else if (context->name_count > 1
994 && context->names[context->name_count-2].name
995 && context->names[context->name_count-2].name == name)
996 idx = context->name_count - 2;
997 else {
998 /* FIXME: how much do we care about inodes that have no
999 * associated name? */
1000 if (context->name_count >= AUDIT_NAMES - AUDIT_NAMES_RESERVED)
1001 return;
1002 idx = context->name_count++;
1003 context->names[idx].name = NULL;
1004 #if AUDIT_DEBUG
1005 ++context->ino_count;
1006 #endif
1008 context->names[idx].ino = inode->i_ino;
1009 context->names[idx].dev = inode->i_sb->s_dev;
1010 context->names[idx].mode = inode->i_mode;
1011 context->names[idx].uid = inode->i_uid;
1012 context->names[idx].gid = inode->i_gid;
1013 context->names[idx].rdev = inode->i_rdev;
1016 void auditsc_get_stamp(struct audit_context *ctx,
1017 struct timespec *t, unsigned int *serial)
1019 t->tv_sec = ctx->ctime.tv_sec;
1020 t->tv_nsec = ctx->ctime.tv_nsec;
1021 *serial = ctx->serial;
1022 ctx->auditable = 1;
1025 int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
1027 if (task->audit_context) {
1028 struct audit_buffer *ab;
1030 ab = audit_log_start(NULL, AUDIT_LOGIN);
1031 if (ab) {
1032 audit_log_format(ab, "login pid=%d uid=%u "
1033 "old auid=%u new auid=%u",
1034 task->pid, task->uid,
1035 task->audit_context->loginuid, loginuid);
1036 audit_log_end(ab);
1038 task->audit_context->loginuid = loginuid;
1040 return 0;
1043 uid_t audit_get_loginuid(struct audit_context *ctx)
1045 return ctx ? ctx->loginuid : -1;
1048 int audit_ipc_perms(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
1050 struct audit_aux_data_ipcctl *ax;
1051 struct audit_context *context = current->audit_context;
1053 if (likely(!context))
1054 return 0;
1056 ax = kmalloc(sizeof(*ax), GFP_KERNEL);
1057 if (!ax)
1058 return -ENOMEM;
1060 ax->qbytes = qbytes;
1061 ax->uid = uid;
1062 ax->gid = gid;
1063 ax->mode = mode;
1065 ax->d.type = AUDIT_IPC;
1066 ax->d.next = context->aux;
1067 context->aux = (void *)ax;
1068 return 0;
1071 int audit_socketcall(int nargs, unsigned long *args)
1073 struct audit_aux_data_socketcall *ax;
1074 struct audit_context *context = current->audit_context;
1076 if (likely(!context))
1077 return 0;
1079 ax = kmalloc(sizeof(*ax) + nargs * sizeof(unsigned long), GFP_KERNEL);
1080 if (!ax)
1081 return -ENOMEM;
1083 ax->nargs = nargs;
1084 memcpy(ax->args, args, nargs * sizeof(unsigned long));
1086 ax->d.type = AUDIT_SOCKETCALL;
1087 ax->d.next = context->aux;
1088 context->aux = (void *)ax;
1089 return 0;
1092 int audit_sockaddr(int len, void *a)
1094 struct audit_aux_data_sockaddr *ax;
1095 struct audit_context *context = current->audit_context;
1097 if (likely(!context))
1098 return 0;
1100 ax = kmalloc(sizeof(*ax) + len, GFP_KERNEL);
1101 if (!ax)
1102 return -ENOMEM;
1104 ax->len = len;
1105 memcpy(ax->a, a, len);
1107 ax->d.type = AUDIT_SOCKADDR;
1108 ax->d.next = context->aux;
1109 context->aux = (void *)ax;
1110 return 0;
1113 int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
1115 struct audit_aux_data_path *ax;
1116 struct audit_context *context = current->audit_context;
1118 if (likely(!context))
1119 return 0;
1121 ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
1122 if (!ax)
1123 return -ENOMEM;
1125 ax->dentry = dget(dentry);
1126 ax->mnt = mntget(mnt);
1128 ax->d.type = AUDIT_AVC_PATH;
1129 ax->d.next = context->aux;
1130 context->aux = (void *)ax;
1131 return 0;
1134 void audit_signal_info(int sig, struct task_struct *t)
1136 extern pid_t audit_sig_pid;
1137 extern uid_t audit_sig_uid;
1139 if (unlikely(audit_pid && t->pid == audit_pid)) {
1140 if (sig == SIGTERM || sig == SIGHUP) {
1141 struct audit_context *ctx = current->audit_context;
1142 audit_sig_pid = current->pid;
1143 if (ctx)
1144 audit_sig_uid = ctx->loginuid;
1145 else
1146 audit_sig_uid = current->uid;