audit: catch possible NULL audit buffers
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / audit.c
bloba219998aecc1861591f44b6be9ba1280cb3d3772
1 /* audit.c -- Auditing support
2 * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
3 * System-call specific features have moved to auditsc.c
5 * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
6 * All Rights Reserved.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * Written by Rickard E. (Rik) Faith <faith@redhat.com>
24 * Goals: 1) Integrate fully with Security Modules.
25 * 2) Minimal run-time overhead:
26 * a) Minimal when syscall auditing is disabled (audit_enable=0).
27 * b) Small when syscall auditing is enabled and no audit record
28 * is generated (defer as much work as possible to record
29 * generation time):
30 * i) context is allocated,
31 * ii) names from getname are stored without a copy, and
32 * iii) inode information stored from path_lookup.
33 * 3) Ability to disable syscall auditing at boot time (audit=0).
34 * 4) Usable by other parts of the kernel (if audit_log* is called,
35 * then a syscall record will be generated automatically for the
36 * current syscall).
37 * 5) Netlink interface to user-space.
38 * 6) Support low-overhead kernel-based filtering to minimize the
39 * information that must be passed to user-space.
41 * Example user-space utilities: http://people.redhat.com/sgrubb/audit/
44 #include <linux/init.h>
45 #include <asm/types.h>
46 #include <linux/atomic.h>
47 #include <linux/mm.h>
48 #include <linux/export.h>
49 #include <linux/slab.h>
50 #include <linux/err.h>
51 #include <linux/kthread.h>
53 #include <linux/audit.h>
55 #include <net/sock.h>
56 #include <net/netlink.h>
57 #include <linux/skbuff.h>
58 #ifdef CONFIG_SECURITY
59 #include <linux/security.h>
60 #endif
61 #include <linux/netlink.h>
62 #include <linux/freezer.h>
63 #include <linux/tty.h>
64 #include <linux/pid_namespace.h>
66 #include "audit.h"
68 /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
69 * (Initialization happens after skb_init is called.) */
70 #define AUDIT_DISABLED -1
71 #define AUDIT_UNINITIALIZED 0
72 #define AUDIT_INITIALIZED 1
73 static int audit_initialized;
75 #define AUDIT_OFF 0
76 #define AUDIT_ON 1
77 #define AUDIT_LOCKED 2
78 int audit_enabled;
79 int audit_ever_enabled;
81 EXPORT_SYMBOL_GPL(audit_enabled);
83 /* Default state when kernel boots without any parameters. */
84 static int audit_default;
86 /* If auditing cannot proceed, audit_failure selects what happens. */
87 static int audit_failure = AUDIT_FAIL_PRINTK;
90 * If audit records are to be written to the netlink socket, audit_pid
91 * contains the pid of the auditd process and audit_nlk_portid contains
92 * the portid to use to send netlink messages to that process.
94 int audit_pid;
95 static int audit_nlk_portid;
97 /* If audit_rate_limit is non-zero, limit the rate of sending audit records
98 * to that number per second. This prevents DoS attacks, but results in
99 * audit records being dropped. */
100 static int audit_rate_limit;
102 /* Number of outstanding audit_buffers allowed. */
103 static int audit_backlog_limit = 64;
104 static int audit_backlog_wait_time = 60 * HZ;
105 static int audit_backlog_wait_overflow = 0;
107 /* The identity of the user shutting down the audit system. */
108 kuid_t audit_sig_uid = INVALID_UID;
109 pid_t audit_sig_pid = -1;
110 u32 audit_sig_sid = 0;
112 /* Records can be lost in several ways:
113 0) [suppressed in audit_alloc]
114 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
115 2) out of memory in audit_log_move [alloc_skb]
116 3) suppressed due to audit_rate_limit
117 4) suppressed due to audit_backlog_limit
119 static atomic_t audit_lost = ATOMIC_INIT(0);
121 /* The netlink socket. */
122 static struct sock *audit_sock;
124 /* Hash for inode-based rules */
125 struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
127 /* The audit_freelist is a list of pre-allocated audit buffers (if more
128 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
129 * being placed on the freelist). */
130 static DEFINE_SPINLOCK(audit_freelist_lock);
131 static int audit_freelist_count;
132 static LIST_HEAD(audit_freelist);
134 static struct sk_buff_head audit_skb_queue;
135 /* queue of skbs to send to auditd when/if it comes back */
136 static struct sk_buff_head audit_skb_hold_queue;
137 static struct task_struct *kauditd_task;
138 static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
139 static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
141 /* Serialize requests from userspace. */
142 DEFINE_MUTEX(audit_cmd_mutex);
144 /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
145 * audit records. Since printk uses a 1024 byte buffer, this buffer
146 * should be at least that large. */
147 #define AUDIT_BUFSIZ 1024
149 /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
150 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
151 #define AUDIT_MAXFREE (2*NR_CPUS)
153 /* The audit_buffer is used when formatting an audit record. The caller
154 * locks briefly to get the record off the freelist or to allocate the
155 * buffer, and locks briefly to send the buffer to the netlink layer or
156 * to place it on a transmit queue. Multiple audit_buffers can be in
157 * use simultaneously. */
158 struct audit_buffer {
159 struct list_head list;
160 struct sk_buff *skb; /* formatted skb ready to send */
161 struct audit_context *ctx; /* NULL or associated context */
162 gfp_t gfp_mask;
165 struct audit_reply {
166 int pid;
167 struct sk_buff *skb;
170 static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
172 if (ab) {
173 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
174 nlh->nlmsg_pid = pid;
178 void audit_panic(const char *message)
180 switch (audit_failure)
182 case AUDIT_FAIL_SILENT:
183 break;
184 case AUDIT_FAIL_PRINTK:
185 if (printk_ratelimit())
186 printk(KERN_ERR "audit: %s\n", message);
187 break;
188 case AUDIT_FAIL_PANIC:
189 /* test audit_pid since printk is always losey, why bother? */
190 if (audit_pid)
191 panic("audit: %s\n", message);
192 break;
196 static inline int audit_rate_check(void)
198 static unsigned long last_check = 0;
199 static int messages = 0;
200 static DEFINE_SPINLOCK(lock);
201 unsigned long flags;
202 unsigned long now;
203 unsigned long elapsed;
204 int retval = 0;
206 if (!audit_rate_limit) return 1;
208 spin_lock_irqsave(&lock, flags);
209 if (++messages < audit_rate_limit) {
210 retval = 1;
211 } else {
212 now = jiffies;
213 elapsed = now - last_check;
214 if (elapsed > HZ) {
215 last_check = now;
216 messages = 0;
217 retval = 1;
220 spin_unlock_irqrestore(&lock, flags);
222 return retval;
226 * audit_log_lost - conditionally log lost audit message event
227 * @message: the message stating reason for lost audit message
229 * Emit at least 1 message per second, even if audit_rate_check is
230 * throttling.
231 * Always increment the lost messages counter.
233 void audit_log_lost(const char *message)
235 static unsigned long last_msg = 0;
236 static DEFINE_SPINLOCK(lock);
237 unsigned long flags;
238 unsigned long now;
239 int print;
241 atomic_inc(&audit_lost);
243 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
245 if (!print) {
246 spin_lock_irqsave(&lock, flags);
247 now = jiffies;
248 if (now - last_msg > HZ) {
249 print = 1;
250 last_msg = now;
252 spin_unlock_irqrestore(&lock, flags);
255 if (print) {
256 if (printk_ratelimit())
257 printk(KERN_WARNING
258 "audit: audit_lost=%d audit_rate_limit=%d "
259 "audit_backlog_limit=%d\n",
260 atomic_read(&audit_lost),
261 audit_rate_limit,
262 audit_backlog_limit);
263 audit_panic(message);
267 static int audit_log_config_change(char *function_name, int new, int old,
268 kuid_t loginuid, u32 sessionid, u32 sid,
269 int allow_changes)
271 struct audit_buffer *ab;
272 int rc = 0;
274 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
275 if (unlikely(!ab))
276 return rc;
277 audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
278 old, from_kuid(&init_user_ns, loginuid), sessionid);
279 if (sid) {
280 char *ctx = NULL;
281 u32 len;
283 rc = security_secid_to_secctx(sid, &ctx, &len);
284 if (rc) {
285 audit_log_format(ab, " sid=%u", sid);
286 allow_changes = 0; /* Something weird, deny request */
287 } else {
288 audit_log_format(ab, " subj=%s", ctx);
289 security_release_secctx(ctx, len);
292 audit_log_format(ab, " res=%d", allow_changes);
293 audit_log_end(ab);
294 return rc;
297 static int audit_do_config_change(char *function_name, int *to_change,
298 int new, kuid_t loginuid, u32 sessionid,
299 u32 sid)
301 int allow_changes, rc = 0, old = *to_change;
303 /* check if we are locked */
304 if (audit_enabled == AUDIT_LOCKED)
305 allow_changes = 0;
306 else
307 allow_changes = 1;
309 if (audit_enabled != AUDIT_OFF) {
310 rc = audit_log_config_change(function_name, new, old, loginuid,
311 sessionid, sid, allow_changes);
312 if (rc)
313 allow_changes = 0;
316 /* If we are allowed, make the change */
317 if (allow_changes == 1)
318 *to_change = new;
319 /* Not allowed, update reason */
320 else if (rc == 0)
321 rc = -EPERM;
322 return rc;
325 static int audit_set_rate_limit(int limit, kuid_t loginuid, u32 sessionid,
326 u32 sid)
328 return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
329 limit, loginuid, sessionid, sid);
332 static int audit_set_backlog_limit(int limit, kuid_t loginuid, u32 sessionid,
333 u32 sid)
335 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
336 limit, loginuid, sessionid, sid);
339 static int audit_set_enabled(int state, kuid_t loginuid, u32 sessionid, u32 sid)
341 int rc;
342 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
343 return -EINVAL;
345 rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
346 loginuid, sessionid, sid);
348 if (!rc)
349 audit_ever_enabled |= !!state;
351 return rc;
354 static int audit_set_failure(int state, kuid_t loginuid, u32 sessionid, u32 sid)
356 if (state != AUDIT_FAIL_SILENT
357 && state != AUDIT_FAIL_PRINTK
358 && state != AUDIT_FAIL_PANIC)
359 return -EINVAL;
361 return audit_do_config_change("audit_failure", &audit_failure, state,
362 loginuid, sessionid, sid);
366 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
367 * already have been sent via prink/syslog and so if these messages are dropped
368 * it is not a huge concern since we already passed the audit_log_lost()
369 * notification and stuff. This is just nice to get audit messages during
370 * boot before auditd is running or messages generated while auditd is stopped.
371 * This only holds messages is audit_default is set, aka booting with audit=1
372 * or building your kernel that way.
374 static void audit_hold_skb(struct sk_buff *skb)
376 if (audit_default &&
377 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
378 skb_queue_tail(&audit_skb_hold_queue, skb);
379 else
380 kfree_skb(skb);
384 * For one reason or another this nlh isn't getting delivered to the userspace
385 * audit daemon, just send it to printk.
387 static void audit_printk_skb(struct sk_buff *skb)
389 struct nlmsghdr *nlh = nlmsg_hdr(skb);
390 char *data = nlmsg_data(nlh);
392 if (nlh->nlmsg_type != AUDIT_EOE) {
393 if (printk_ratelimit())
394 printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data);
395 else
396 audit_log_lost("printk limit exceeded\n");
399 audit_hold_skb(skb);
402 static void kauditd_send_skb(struct sk_buff *skb)
404 int err;
405 /* take a reference in case we can't send it and we want to hold it */
406 skb_get(skb);
407 err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
408 if (err < 0) {
409 BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
410 printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
411 audit_log_lost("auditd disappeared\n");
412 audit_pid = 0;
413 /* we might get lucky and get this in the next auditd */
414 audit_hold_skb(skb);
415 } else
416 /* drop the extra reference if sent ok */
417 consume_skb(skb);
420 static int kauditd_thread(void *dummy)
422 struct sk_buff *skb;
424 set_freezable();
425 while (!kthread_should_stop()) {
427 * if auditd just started drain the queue of messages already
428 * sent to syslog/printk. remember loss here is ok. we already
429 * called audit_log_lost() if it didn't go out normally. so the
430 * race between the skb_dequeue and the next check for audit_pid
431 * doesn't matter.
433 * if you ever find kauditd to be too slow we can get a perf win
434 * by doing our own locking and keeping better track if there
435 * are messages in this queue. I don't see the need now, but
436 * in 5 years when I want to play with this again I'll see this
437 * note and still have no friggin idea what i'm thinking today.
439 if (audit_default && audit_pid) {
440 skb = skb_dequeue(&audit_skb_hold_queue);
441 if (unlikely(skb)) {
442 while (skb && audit_pid) {
443 kauditd_send_skb(skb);
444 skb = skb_dequeue(&audit_skb_hold_queue);
449 skb = skb_dequeue(&audit_skb_queue);
450 wake_up(&audit_backlog_wait);
451 if (skb) {
452 if (audit_pid)
453 kauditd_send_skb(skb);
454 else
455 audit_printk_skb(skb);
456 } else {
457 DECLARE_WAITQUEUE(wait, current);
458 set_current_state(TASK_INTERRUPTIBLE);
459 add_wait_queue(&kauditd_wait, &wait);
461 if (!skb_queue_len(&audit_skb_queue)) {
462 try_to_freeze();
463 schedule();
466 __set_current_state(TASK_RUNNING);
467 remove_wait_queue(&kauditd_wait, &wait);
470 return 0;
473 int audit_send_list(void *_dest)
475 struct audit_netlink_list *dest = _dest;
476 int pid = dest->pid;
477 struct sk_buff *skb;
479 /* wait for parent to finish and send an ACK */
480 mutex_lock(&audit_cmd_mutex);
481 mutex_unlock(&audit_cmd_mutex);
483 while ((skb = __skb_dequeue(&dest->q)) != NULL)
484 netlink_unicast(audit_sock, skb, pid, 0);
486 kfree(dest);
488 return 0;
491 struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
492 int multi, const void *payload, int size)
494 struct sk_buff *skb;
495 struct nlmsghdr *nlh;
496 void *data;
497 int flags = multi ? NLM_F_MULTI : 0;
498 int t = done ? NLMSG_DONE : type;
500 skb = nlmsg_new(size, GFP_KERNEL);
501 if (!skb)
502 return NULL;
504 nlh = nlmsg_put(skb, pid, seq, t, size, flags);
505 if (!nlh)
506 goto out_kfree_skb;
507 data = nlmsg_data(nlh);
508 memcpy(data, payload, size);
509 return skb;
511 out_kfree_skb:
512 kfree_skb(skb);
513 return NULL;
516 static int audit_send_reply_thread(void *arg)
518 struct audit_reply *reply = (struct audit_reply *)arg;
520 mutex_lock(&audit_cmd_mutex);
521 mutex_unlock(&audit_cmd_mutex);
523 /* Ignore failure. It'll only happen if the sender goes away,
524 because our timeout is set to infinite. */
525 netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
526 kfree(reply);
527 return 0;
530 * audit_send_reply - send an audit reply message via netlink
531 * @pid: process id to send reply to
532 * @seq: sequence number
533 * @type: audit message type
534 * @done: done (last) flag
535 * @multi: multi-part message flag
536 * @payload: payload data
537 * @size: payload size
539 * Allocates an skb, builds the netlink message, and sends it to the pid.
540 * No failure notifications.
542 static void audit_send_reply(int pid, int seq, int type, int done, int multi,
543 const void *payload, int size)
545 struct sk_buff *skb;
546 struct task_struct *tsk;
547 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
548 GFP_KERNEL);
550 if (!reply)
551 return;
553 skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
554 if (!skb)
555 goto out;
557 reply->pid = pid;
558 reply->skb = skb;
560 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
561 if (!IS_ERR(tsk))
562 return;
563 kfree_skb(skb);
564 out:
565 kfree(reply);
569 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
570 * control messages.
572 static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
574 int err = 0;
576 /* Only support the initial namespaces for now. */
577 if ((current_user_ns() != &init_user_ns) ||
578 (task_active_pid_ns(current) != &init_pid_ns))
579 return -EPERM;
581 switch (msg_type) {
582 case AUDIT_GET:
583 case AUDIT_LIST:
584 case AUDIT_LIST_RULES:
585 case AUDIT_SET:
586 case AUDIT_ADD:
587 case AUDIT_ADD_RULE:
588 case AUDIT_DEL:
589 case AUDIT_DEL_RULE:
590 case AUDIT_SIGNAL_INFO:
591 case AUDIT_TTY_GET:
592 case AUDIT_TTY_SET:
593 case AUDIT_TRIM:
594 case AUDIT_MAKE_EQUIV:
595 if (!capable(CAP_AUDIT_CONTROL))
596 err = -EPERM;
597 break;
598 case AUDIT_USER:
599 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
600 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
601 if (!capable(CAP_AUDIT_WRITE))
602 err = -EPERM;
603 break;
604 default: /* bad msg */
605 err = -EINVAL;
608 return err;
611 static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
612 kuid_t auid, u32 ses, u32 sid)
614 int rc = 0;
615 char *ctx = NULL;
616 u32 len;
618 if (!audit_enabled) {
619 *ab = NULL;
620 return rc;
623 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
624 if (unlikely(!*ab))
625 return rc;
626 audit_log_format(*ab, "pid=%d uid=%u auid=%u ses=%u",
627 task_tgid_vnr(current),
628 from_kuid(&init_user_ns, current_uid()),
629 from_kuid(&init_user_ns, auid), ses);
630 if (sid) {
631 rc = security_secid_to_secctx(sid, &ctx, &len);
632 if (rc)
633 audit_log_format(*ab, " ssid=%u", sid);
634 else {
635 audit_log_format(*ab, " subj=%s", ctx);
636 security_release_secctx(ctx, len);
640 return rc;
643 static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
645 u32 seq, sid;
646 void *data;
647 struct audit_status *status_get, status_set;
648 int err;
649 struct audit_buffer *ab;
650 u16 msg_type = nlh->nlmsg_type;
651 kuid_t loginuid; /* loginuid of sender */
652 u32 sessionid;
653 struct audit_sig_info *sig_data;
654 char *ctx = NULL;
655 u32 len;
657 err = audit_netlink_ok(skb, msg_type);
658 if (err)
659 return err;
661 /* As soon as there's any sign of userspace auditd,
662 * start kauditd to talk to it */
663 if (!kauditd_task)
664 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
665 if (IS_ERR(kauditd_task)) {
666 err = PTR_ERR(kauditd_task);
667 kauditd_task = NULL;
668 return err;
671 loginuid = audit_get_loginuid(current);
672 sessionid = audit_get_sessionid(current);
673 security_task_getsecid(current, &sid);
674 seq = nlh->nlmsg_seq;
675 data = nlmsg_data(nlh);
677 switch (msg_type) {
678 case AUDIT_GET:
679 status_set.enabled = audit_enabled;
680 status_set.failure = audit_failure;
681 status_set.pid = audit_pid;
682 status_set.rate_limit = audit_rate_limit;
683 status_set.backlog_limit = audit_backlog_limit;
684 status_set.lost = atomic_read(&audit_lost);
685 status_set.backlog = skb_queue_len(&audit_skb_queue);
686 audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0,
687 &status_set, sizeof(status_set));
688 break;
689 case AUDIT_SET:
690 if (nlh->nlmsg_len < sizeof(struct audit_status))
691 return -EINVAL;
692 status_get = (struct audit_status *)data;
693 if (status_get->mask & AUDIT_STATUS_ENABLED) {
694 err = audit_set_enabled(status_get->enabled,
695 loginuid, sessionid, sid);
696 if (err < 0)
697 return err;
699 if (status_get->mask & AUDIT_STATUS_FAILURE) {
700 err = audit_set_failure(status_get->failure,
701 loginuid, sessionid, sid);
702 if (err < 0)
703 return err;
705 if (status_get->mask & AUDIT_STATUS_PID) {
706 int new_pid = status_get->pid;
708 if (audit_enabled != AUDIT_OFF)
709 audit_log_config_change("audit_pid", new_pid,
710 audit_pid, loginuid,
711 sessionid, sid, 1);
713 audit_pid = new_pid;
714 audit_nlk_portid = NETLINK_CB(skb).portid;
716 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
717 err = audit_set_rate_limit(status_get->rate_limit,
718 loginuid, sessionid, sid);
719 if (err < 0)
720 return err;
722 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
723 err = audit_set_backlog_limit(status_get->backlog_limit,
724 loginuid, sessionid, sid);
725 break;
726 case AUDIT_USER:
727 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
728 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
729 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
730 return 0;
732 err = audit_filter_user();
733 if (err == 1) {
734 err = 0;
735 if (msg_type == AUDIT_USER_TTY) {
736 err = tty_audit_push_task(current, loginuid,
737 sessionid);
738 if (err)
739 break;
741 audit_log_common_recv_msg(&ab, msg_type,
742 loginuid, sessionid, sid);
744 if (msg_type != AUDIT_USER_TTY)
745 audit_log_format(ab, " msg='%.1024s'",
746 (char *)data);
747 else {
748 int size;
750 audit_log_format(ab, " msg=");
751 size = nlmsg_len(nlh);
752 if (size > 0 &&
753 ((unsigned char *)data)[size - 1] == '\0')
754 size--;
755 audit_log_n_untrustedstring(ab, data, size);
757 audit_set_pid(ab, NETLINK_CB(skb).portid);
758 audit_log_end(ab);
760 break;
761 case AUDIT_ADD:
762 case AUDIT_DEL:
763 if (nlmsg_len(nlh) < sizeof(struct audit_rule))
764 return -EINVAL;
765 if (audit_enabled == AUDIT_LOCKED) {
766 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE,
767 loginuid, sessionid, sid);
769 audit_log_format(ab, " audit_enabled=%d res=0",
770 audit_enabled);
771 audit_log_end(ab);
772 return -EPERM;
774 /* fallthrough */
775 case AUDIT_LIST:
776 err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid,
777 seq, data, nlmsg_len(nlh),
778 loginuid, sessionid, sid);
779 break;
780 case AUDIT_ADD_RULE:
781 case AUDIT_DEL_RULE:
782 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
783 return -EINVAL;
784 if (audit_enabled == AUDIT_LOCKED) {
785 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE,
786 loginuid, sessionid, sid);
788 audit_log_format(ab, " audit_enabled=%d res=0",
789 audit_enabled);
790 audit_log_end(ab);
791 return -EPERM;
793 /* fallthrough */
794 case AUDIT_LIST_RULES:
795 err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid,
796 seq, data, nlmsg_len(nlh),
797 loginuid, sessionid, sid);
798 break;
799 case AUDIT_TRIM:
800 audit_trim_trees();
802 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE,
803 loginuid, sessionid, sid);
805 audit_log_format(ab, " op=trim res=1");
806 audit_log_end(ab);
807 break;
808 case AUDIT_MAKE_EQUIV: {
809 void *bufp = data;
810 u32 sizes[2];
811 size_t msglen = nlmsg_len(nlh);
812 char *old, *new;
814 err = -EINVAL;
815 if (msglen < 2 * sizeof(u32))
816 break;
817 memcpy(sizes, bufp, 2 * sizeof(u32));
818 bufp += 2 * sizeof(u32);
819 msglen -= 2 * sizeof(u32);
820 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
821 if (IS_ERR(old)) {
822 err = PTR_ERR(old);
823 break;
825 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
826 if (IS_ERR(new)) {
827 err = PTR_ERR(new);
828 kfree(old);
829 break;
831 /* OK, here comes... */
832 err = audit_tag_tree(old, new);
834 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE,
835 loginuid, sessionid, sid);
837 audit_log_format(ab, " op=make_equiv old=");
838 audit_log_untrustedstring(ab, old);
839 audit_log_format(ab, " new=");
840 audit_log_untrustedstring(ab, new);
841 audit_log_format(ab, " res=%d", !err);
842 audit_log_end(ab);
843 kfree(old);
844 kfree(new);
845 break;
847 case AUDIT_SIGNAL_INFO:
848 len = 0;
849 if (audit_sig_sid) {
850 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
851 if (err)
852 return err;
854 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
855 if (!sig_data) {
856 if (audit_sig_sid)
857 security_release_secctx(ctx, len);
858 return -ENOMEM;
860 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
861 sig_data->pid = audit_sig_pid;
862 if (audit_sig_sid) {
863 memcpy(sig_data->ctx, ctx, len);
864 security_release_secctx(ctx, len);
866 audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO,
867 0, 0, sig_data, sizeof(*sig_data) + len);
868 kfree(sig_data);
869 break;
870 case AUDIT_TTY_GET: {
871 struct audit_tty_status s;
872 struct task_struct *tsk = current;
874 spin_lock_irq(&tsk->sighand->siglock);
875 s.enabled = tsk->signal->audit_tty != 0;
876 spin_unlock_irq(&tsk->sighand->siglock);
878 audit_send_reply(NETLINK_CB(skb).portid, seq,
879 AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
880 break;
882 case AUDIT_TTY_SET: {
883 struct audit_tty_status *s;
884 struct task_struct *tsk = current;
886 if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
887 return -EINVAL;
888 s = data;
889 if (s->enabled != 0 && s->enabled != 1)
890 return -EINVAL;
892 spin_lock_irq(&tsk->sighand->siglock);
893 tsk->signal->audit_tty = s->enabled != 0;
894 spin_unlock_irq(&tsk->sighand->siglock);
895 break;
897 default:
898 err = -EINVAL;
899 break;
902 return err < 0 ? err : 0;
906 * Get message from skb. Each message is processed by audit_receive_msg.
907 * Malformed skbs with wrong length are discarded silently.
909 static void audit_receive_skb(struct sk_buff *skb)
911 struct nlmsghdr *nlh;
913 * len MUST be signed for NLMSG_NEXT to be able to dec it below 0
914 * if the nlmsg_len was not aligned
916 int len;
917 int err;
919 nlh = nlmsg_hdr(skb);
920 len = skb->len;
922 while (NLMSG_OK(nlh, len)) {
923 err = audit_receive_msg(skb, nlh);
924 /* if err or if this message says it wants a response */
925 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
926 netlink_ack(skb, nlh, err);
928 nlh = NLMSG_NEXT(nlh, len);
932 /* Receive messages from netlink socket. */
933 static void audit_receive(struct sk_buff *skb)
935 mutex_lock(&audit_cmd_mutex);
936 audit_receive_skb(skb);
937 mutex_unlock(&audit_cmd_mutex);
940 /* Initialize audit support at boot time. */
941 static int __init audit_init(void)
943 int i;
944 struct netlink_kernel_cfg cfg = {
945 .input = audit_receive,
948 if (audit_initialized == AUDIT_DISABLED)
949 return 0;
951 printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
952 audit_default ? "enabled" : "disabled");
953 audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, &cfg);
954 if (!audit_sock)
955 audit_panic("cannot initialize netlink socket");
956 else
957 audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
959 skb_queue_head_init(&audit_skb_queue);
960 skb_queue_head_init(&audit_skb_hold_queue);
961 audit_initialized = AUDIT_INITIALIZED;
962 audit_enabled = audit_default;
963 audit_ever_enabled |= !!audit_default;
965 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
967 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
968 INIT_LIST_HEAD(&audit_inode_hash[i]);
970 return 0;
972 __initcall(audit_init);
974 /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
975 static int __init audit_enable(char *str)
977 audit_default = !!simple_strtol(str, NULL, 0);
978 if (!audit_default)
979 audit_initialized = AUDIT_DISABLED;
981 printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
983 if (audit_initialized == AUDIT_INITIALIZED) {
984 audit_enabled = audit_default;
985 audit_ever_enabled |= !!audit_default;
986 } else if (audit_initialized == AUDIT_UNINITIALIZED) {
987 printk(" (after initialization)");
988 } else {
989 printk(" (until reboot)");
991 printk("\n");
993 return 1;
996 __setup("audit=", audit_enable);
998 static void audit_buffer_free(struct audit_buffer *ab)
1000 unsigned long flags;
1002 if (!ab)
1003 return;
1005 if (ab->skb)
1006 kfree_skb(ab->skb);
1008 spin_lock_irqsave(&audit_freelist_lock, flags);
1009 if (audit_freelist_count > AUDIT_MAXFREE)
1010 kfree(ab);
1011 else {
1012 audit_freelist_count++;
1013 list_add(&ab->list, &audit_freelist);
1015 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1018 static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
1019 gfp_t gfp_mask, int type)
1021 unsigned long flags;
1022 struct audit_buffer *ab = NULL;
1023 struct nlmsghdr *nlh;
1025 spin_lock_irqsave(&audit_freelist_lock, flags);
1026 if (!list_empty(&audit_freelist)) {
1027 ab = list_entry(audit_freelist.next,
1028 struct audit_buffer, list);
1029 list_del(&ab->list);
1030 --audit_freelist_count;
1032 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1034 if (!ab) {
1035 ab = kmalloc(sizeof(*ab), gfp_mask);
1036 if (!ab)
1037 goto err;
1040 ab->ctx = ctx;
1041 ab->gfp_mask = gfp_mask;
1043 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1044 if (!ab->skb)
1045 goto err;
1047 nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0);
1048 if (!nlh)
1049 goto out_kfree_skb;
1051 return ab;
1053 out_kfree_skb:
1054 kfree_skb(ab->skb);
1055 ab->skb = NULL;
1056 err:
1057 audit_buffer_free(ab);
1058 return NULL;
1062 * audit_serial - compute a serial number for the audit record
1064 * Compute a serial number for the audit record. Audit records are
1065 * written to user-space as soon as they are generated, so a complete
1066 * audit record may be written in several pieces. The timestamp of the
1067 * record and this serial number are used by the user-space tools to
1068 * determine which pieces belong to the same audit record. The
1069 * (timestamp,serial) tuple is unique for each syscall and is live from
1070 * syscall entry to syscall exit.
1072 * NOTE: Another possibility is to store the formatted records off the
1073 * audit context (for those records that have a context), and emit them
1074 * all at syscall exit. However, this could delay the reporting of
1075 * significant errors until syscall exit (or never, if the system
1076 * halts).
1078 unsigned int audit_serial(void)
1080 static DEFINE_SPINLOCK(serial_lock);
1081 static unsigned int serial = 0;
1083 unsigned long flags;
1084 unsigned int ret;
1086 spin_lock_irqsave(&serial_lock, flags);
1087 do {
1088 ret = ++serial;
1089 } while (unlikely(!ret));
1090 spin_unlock_irqrestore(&serial_lock, flags);
1092 return ret;
1095 static inline void audit_get_stamp(struct audit_context *ctx,
1096 struct timespec *t, unsigned int *serial)
1098 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1099 *t = CURRENT_TIME;
1100 *serial = audit_serial();
1104 /* Obtain an audit buffer. This routine does locking to obtain the
1105 * audit buffer, but then no locking is required for calls to
1106 * audit_log_*format. If the tsk is a task that is currently in a
1107 * syscall, then the syscall is marked as auditable and an audit record
1108 * will be written at syscall exit. If there is no associated task, tsk
1109 * should be NULL. */
1112 * audit_log_start - obtain an audit buffer
1113 * @ctx: audit_context (may be NULL)
1114 * @gfp_mask: type of allocation
1115 * @type: audit message type
1117 * Returns audit_buffer pointer on success or NULL on error.
1119 * Obtain an audit buffer. This routine does locking to obtain the
1120 * audit buffer, but then no locking is required for calls to
1121 * audit_log_*format. If the task (ctx) is a task that is currently in a
1122 * syscall, then the syscall is marked as auditable and an audit record
1123 * will be written at syscall exit. If there is no associated task, then
1124 * task context (ctx) should be NULL.
1126 struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1127 int type)
1129 struct audit_buffer *ab = NULL;
1130 struct timespec t;
1131 unsigned int uninitialized_var(serial);
1132 int reserve;
1133 unsigned long timeout_start = jiffies;
1135 if (audit_initialized != AUDIT_INITIALIZED)
1136 return NULL;
1138 if (unlikely(audit_filter_type(type)))
1139 return NULL;
1141 if (gfp_mask & __GFP_WAIT)
1142 reserve = 0;
1143 else
1144 reserve = 5; /* Allow atomic callers to go up to five
1145 entries over the normal backlog limit */
1147 while (audit_backlog_limit
1148 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
1149 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time
1150 && time_before(jiffies, timeout_start + audit_backlog_wait_time)) {
1152 /* Wait for auditd to drain the queue a little */
1153 DECLARE_WAITQUEUE(wait, current);
1154 set_current_state(TASK_INTERRUPTIBLE);
1155 add_wait_queue(&audit_backlog_wait, &wait);
1157 if (audit_backlog_limit &&
1158 skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
1159 schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies);
1161 __set_current_state(TASK_RUNNING);
1162 remove_wait_queue(&audit_backlog_wait, &wait);
1163 continue;
1165 if (audit_rate_check() && printk_ratelimit())
1166 printk(KERN_WARNING
1167 "audit: audit_backlog=%d > "
1168 "audit_backlog_limit=%d\n",
1169 skb_queue_len(&audit_skb_queue),
1170 audit_backlog_limit);
1171 audit_log_lost("backlog limit exceeded");
1172 audit_backlog_wait_time = audit_backlog_wait_overflow;
1173 wake_up(&audit_backlog_wait);
1174 return NULL;
1177 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1178 if (!ab) {
1179 audit_log_lost("out of memory in audit_log_start");
1180 return NULL;
1183 audit_get_stamp(ab->ctx, &t, &serial);
1185 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1186 t.tv_sec, t.tv_nsec/1000000, serial);
1187 return ab;
1191 * audit_expand - expand skb in the audit buffer
1192 * @ab: audit_buffer
1193 * @extra: space to add at tail of the skb
1195 * Returns 0 (no space) on failed expansion, or available space if
1196 * successful.
1198 static inline int audit_expand(struct audit_buffer *ab, int extra)
1200 struct sk_buff *skb = ab->skb;
1201 int oldtail = skb_tailroom(skb);
1202 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1203 int newtail = skb_tailroom(skb);
1205 if (ret < 0) {
1206 audit_log_lost("out of memory in audit_expand");
1207 return 0;
1210 skb->truesize += newtail - oldtail;
1211 return newtail;
1215 * Format an audit message into the audit buffer. If there isn't enough
1216 * room in the audit buffer, more room will be allocated and vsnprint
1217 * will be called a second time. Currently, we assume that a printk
1218 * can't format message larger than 1024 bytes, so we don't either.
1220 static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1221 va_list args)
1223 int len, avail;
1224 struct sk_buff *skb;
1225 va_list args2;
1227 if (!ab)
1228 return;
1230 BUG_ON(!ab->skb);
1231 skb = ab->skb;
1232 avail = skb_tailroom(skb);
1233 if (avail == 0) {
1234 avail = audit_expand(ab, AUDIT_BUFSIZ);
1235 if (!avail)
1236 goto out;
1238 va_copy(args2, args);
1239 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1240 if (len >= avail) {
1241 /* The printk buffer is 1024 bytes long, so if we get
1242 * here and AUDIT_BUFSIZ is at least 1024, then we can
1243 * log everything that printk could have logged. */
1244 avail = audit_expand(ab,
1245 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1246 if (!avail)
1247 goto out_va_end;
1248 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1250 if (len > 0)
1251 skb_put(skb, len);
1252 out_va_end:
1253 va_end(args2);
1254 out:
1255 return;
1259 * audit_log_format - format a message into the audit buffer.
1260 * @ab: audit_buffer
1261 * @fmt: format string
1262 * @...: optional parameters matching @fmt string
1264 * All the work is done in audit_log_vformat.
1266 void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1268 va_list args;
1270 if (!ab)
1271 return;
1272 va_start(args, fmt);
1273 audit_log_vformat(ab, fmt, args);
1274 va_end(args);
1278 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1279 * @ab: the audit_buffer
1280 * @buf: buffer to convert to hex
1281 * @len: length of @buf to be converted
1283 * No return value; failure to expand is silently ignored.
1285 * This function will take the passed buf and convert it into a string of
1286 * ascii hex digits. The new string is placed onto the skb.
1288 void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1289 size_t len)
1291 int i, avail, new_len;
1292 unsigned char *ptr;
1293 struct sk_buff *skb;
1294 static const unsigned char *hex = "0123456789ABCDEF";
1296 if (!ab)
1297 return;
1299 BUG_ON(!ab->skb);
1300 skb = ab->skb;
1301 avail = skb_tailroom(skb);
1302 new_len = len<<1;
1303 if (new_len >= avail) {
1304 /* Round the buffer request up to the next multiple */
1305 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1306 avail = audit_expand(ab, new_len);
1307 if (!avail)
1308 return;
1311 ptr = skb_tail_pointer(skb);
1312 for (i=0; i<len; i++) {
1313 *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
1314 *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */
1316 *ptr = 0;
1317 skb_put(skb, len << 1); /* new string is twice the old string */
1321 * Format a string of no more than slen characters into the audit buffer,
1322 * enclosed in quote marks.
1324 void audit_log_n_string(struct audit_buffer *ab, const char *string,
1325 size_t slen)
1327 int avail, new_len;
1328 unsigned char *ptr;
1329 struct sk_buff *skb;
1331 if (!ab)
1332 return;
1334 BUG_ON(!ab->skb);
1335 skb = ab->skb;
1336 avail = skb_tailroom(skb);
1337 new_len = slen + 3; /* enclosing quotes + null terminator */
1338 if (new_len > avail) {
1339 avail = audit_expand(ab, new_len);
1340 if (!avail)
1341 return;
1343 ptr = skb_tail_pointer(skb);
1344 *ptr++ = '"';
1345 memcpy(ptr, string, slen);
1346 ptr += slen;
1347 *ptr++ = '"';
1348 *ptr = 0;
1349 skb_put(skb, slen + 2); /* don't include null terminator */
1353 * audit_string_contains_control - does a string need to be logged in hex
1354 * @string: string to be checked
1355 * @len: max length of the string to check
1357 int audit_string_contains_control(const char *string, size_t len)
1359 const unsigned char *p;
1360 for (p = string; p < (const unsigned char *)string + len; p++) {
1361 if (*p == '"' || *p < 0x21 || *p > 0x7e)
1362 return 1;
1364 return 0;
1368 * audit_log_n_untrustedstring - log a string that may contain random characters
1369 * @ab: audit_buffer
1370 * @len: length of string (not including trailing null)
1371 * @string: string to be logged
1373 * This code will escape a string that is passed to it if the string
1374 * contains a control character, unprintable character, double quote mark,
1375 * or a space. Unescaped strings will start and end with a double quote mark.
1376 * Strings that are escaped are printed in hex (2 digits per char).
1378 * The caller specifies the number of characters in the string to log, which may
1379 * or may not be the entire string.
1381 void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1382 size_t len)
1384 if (audit_string_contains_control(string, len))
1385 audit_log_n_hex(ab, string, len);
1386 else
1387 audit_log_n_string(ab, string, len);
1391 * audit_log_untrustedstring - log a string that may contain random characters
1392 * @ab: audit_buffer
1393 * @string: string to be logged
1395 * Same as audit_log_n_untrustedstring(), except that strlen is used to
1396 * determine string length.
1398 void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
1400 audit_log_n_untrustedstring(ab, string, strlen(string));
1403 /* This is a helper-function to print the escaped d_path */
1404 void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
1405 const struct path *path)
1407 char *p, *pathname;
1409 if (prefix)
1410 audit_log_format(ab, "%s", prefix);
1412 /* We will allow 11 spaces for ' (deleted)' to be appended */
1413 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1414 if (!pathname) {
1415 audit_log_string(ab, "<no_memory>");
1416 return;
1418 p = d_path(path, pathname, PATH_MAX+11);
1419 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1420 /* FIXME: can we save some information here? */
1421 audit_log_string(ab, "<too_long>");
1422 } else
1423 audit_log_untrustedstring(ab, p);
1424 kfree(pathname);
1427 void audit_log_key(struct audit_buffer *ab, char *key)
1429 audit_log_format(ab, " key=");
1430 if (key)
1431 audit_log_untrustedstring(ab, key);
1432 else
1433 audit_log_format(ab, "(null)");
1437 * audit_log_link_denied - report a link restriction denial
1438 * @operation: specific link opreation
1439 * @link: the path that triggered the restriction
1441 void audit_log_link_denied(const char *operation, struct path *link)
1443 struct audit_buffer *ab;
1445 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1446 AUDIT_ANOM_LINK);
1447 if (!ab)
1448 return;
1449 audit_log_format(ab, "op=%s action=denied", operation);
1450 audit_log_format(ab, " pid=%d comm=", current->pid);
1451 audit_log_untrustedstring(ab, current->comm);
1452 audit_log_d_path(ab, " path=", link);
1453 audit_log_format(ab, " dev=");
1454 audit_log_untrustedstring(ab, link->dentry->d_inode->i_sb->s_id);
1455 audit_log_format(ab, " ino=%lu", link->dentry->d_inode->i_ino);
1456 audit_log_end(ab);
1460 * audit_log_end - end one audit record
1461 * @ab: the audit_buffer
1463 * The netlink_* functions cannot be called inside an irq context, so
1464 * the audit buffer is placed on a queue and a tasklet is scheduled to
1465 * remove them from the queue outside the irq context. May be called in
1466 * any context.
1468 void audit_log_end(struct audit_buffer *ab)
1470 if (!ab)
1471 return;
1472 if (!audit_rate_check()) {
1473 audit_log_lost("rate limit exceeded");
1474 } else {
1475 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
1476 nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
1478 if (audit_pid) {
1479 skb_queue_tail(&audit_skb_queue, ab->skb);
1480 wake_up_interruptible(&kauditd_wait);
1481 } else {
1482 audit_printk_skb(ab->skb);
1484 ab->skb = NULL;
1486 audit_buffer_free(ab);
1490 * audit_log - Log an audit record
1491 * @ctx: audit context
1492 * @gfp_mask: type of allocation
1493 * @type: audit message type
1494 * @fmt: format string to use
1495 * @...: variable parameters matching the format string
1497 * This is a convenience function that calls audit_log_start,
1498 * audit_log_vformat, and audit_log_end. It may be called
1499 * in any context.
1501 void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
1502 const char *fmt, ...)
1504 struct audit_buffer *ab;
1505 va_list args;
1507 ab = audit_log_start(ctx, gfp_mask, type);
1508 if (ab) {
1509 va_start(args, fmt);
1510 audit_log_vformat(ab, fmt, args);
1511 va_end(args);
1512 audit_log_end(ab);
1516 #ifdef CONFIG_SECURITY
1518 * audit_log_secctx - Converts and logs SELinux context
1519 * @ab: audit_buffer
1520 * @secid: security number
1522 * This is a helper function that calls security_secid_to_secctx to convert
1523 * secid to secctx and then adds the (converted) SELinux context to the audit
1524 * log by calling audit_log_format, thus also preventing leak of internal secid
1525 * to userspace. If secid cannot be converted audit_panic is called.
1527 void audit_log_secctx(struct audit_buffer *ab, u32 secid)
1529 u32 len;
1530 char *secctx;
1532 if (security_secid_to_secctx(secid, &secctx, &len)) {
1533 audit_panic("Cannot convert secid to context");
1534 } else {
1535 audit_log_format(ab, " obj=%s", secctx);
1536 security_release_secctx(secctx, len);
1539 EXPORT_SYMBOL(audit_log_secctx);
1540 #endif
1542 EXPORT_SYMBOL(audit_log_start);
1543 EXPORT_SYMBOL(audit_log_end);
1544 EXPORT_SYMBOL(audit_log_format);
1545 EXPORT_SYMBOL(audit_log);