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.
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
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
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>
48 #include <linux/export.h>
49 #include <linux/slab.h>
50 #include <linux/err.h>
51 #include <linux/kthread.h>
52 #include <linux/kernel.h>
53 #include <linux/syscalls.h>
55 #include <linux/audit.h>
58 #include <net/netlink.h>
59 #include <linux/skbuff.h>
60 #ifdef CONFIG_SECURITY
61 #include <linux/security.h>
63 #include <linux/freezer.h>
64 #include <linux/tty.h>
65 #include <linux/pid_namespace.h>
66 #include <net/netns/generic.h>
70 /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
71 * (Initialization happens after skb_init is called.) */
72 #define AUDIT_DISABLED -1
73 #define AUDIT_UNINITIALIZED 0
74 #define AUDIT_INITIALIZED 1
75 static int audit_initialized;
79 #define AUDIT_LOCKED 2
81 int audit_ever_enabled;
83 EXPORT_SYMBOL_GPL(audit_enabled);
85 /* Default state when kernel boots without any parameters. */
86 static int audit_default;
88 /* If auditing cannot proceed, audit_failure selects what happens. */
89 static int audit_failure = AUDIT_FAIL_PRINTK;
92 * If audit records are to be written to the netlink socket, audit_pid
93 * contains the pid of the auditd process and audit_nlk_portid contains
94 * the portid to use to send netlink messages to that process.
97 static __u32 audit_nlk_portid;
99 /* If audit_rate_limit is non-zero, limit the rate of sending audit records
100 * to that number per second. This prevents DoS attacks, but results in
101 * audit records being dropped. */
102 static int audit_rate_limit;
104 /* Number of outstanding audit_buffers allowed. */
105 static int audit_backlog_limit = 64;
106 static int audit_backlog_wait_time = 60 * HZ;
107 static int audit_backlog_wait_overflow = 0;
109 /* The identity of the user shutting down the audit system. */
110 kuid_t audit_sig_uid = INVALID_UID;
111 pid_t audit_sig_pid = -1;
112 u32 audit_sig_sid = 0;
114 /* Records can be lost in several ways:
115 0) [suppressed in audit_alloc]
116 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
117 2) out of memory in audit_log_move [alloc_skb]
118 3) suppressed due to audit_rate_limit
119 4) suppressed due to audit_backlog_limit
121 static atomic_t audit_lost = ATOMIC_INIT(0);
123 /* The netlink socket. */
124 static struct sock *audit_sock;
127 /* Hash for inode-based rules */
128 struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
130 /* The audit_freelist is a list of pre-allocated audit buffers (if more
131 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
132 * being placed on the freelist). */
133 static DEFINE_SPINLOCK(audit_freelist_lock);
134 static int audit_freelist_count;
135 static LIST_HEAD(audit_freelist);
137 static struct sk_buff_head audit_skb_queue;
138 /* queue of skbs to send to auditd when/if it comes back */
139 static struct sk_buff_head audit_skb_hold_queue;
140 static struct task_struct *kauditd_task;
141 static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
142 static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
144 static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
149 static char *audit_feature_names[2] = {
150 "only_unset_loginuid",
151 "loginuid_immutable",
155 /* Serialize requests from userspace. */
156 DEFINE_MUTEX(audit_cmd_mutex);
158 /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
159 * audit records. Since printk uses a 1024 byte buffer, this buffer
160 * should be at least that large. */
161 #define AUDIT_BUFSIZ 1024
163 /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
164 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
165 #define AUDIT_MAXFREE (2*NR_CPUS)
167 /* The audit_buffer is used when formatting an audit record. The caller
168 * locks briefly to get the record off the freelist or to allocate the
169 * buffer, and locks briefly to send the buffer to the netlink layer or
170 * to place it on a transmit queue. Multiple audit_buffers can be in
171 * use simultaneously. */
172 struct audit_buffer {
173 struct list_head list;
174 struct sk_buff *skb; /* formatted skb ready to send */
175 struct audit_context *ctx; /* NULL or associated context */
185 static void audit_set_portid(struct audit_buffer *ab, __u32 portid)
188 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
189 nlh->nlmsg_pid = portid;
193 void audit_panic(const char *message)
195 switch (audit_failure)
197 case AUDIT_FAIL_SILENT:
199 case AUDIT_FAIL_PRINTK:
200 if (printk_ratelimit())
201 printk(KERN_ERR "audit: %s\n", message);
203 case AUDIT_FAIL_PANIC:
204 /* test audit_pid since printk is always losey, why bother? */
206 panic("audit: %s\n", message);
211 static inline int audit_rate_check(void)
213 static unsigned long last_check = 0;
214 static int messages = 0;
215 static DEFINE_SPINLOCK(lock);
218 unsigned long elapsed;
221 if (!audit_rate_limit) return 1;
223 spin_lock_irqsave(&lock, flags);
224 if (++messages < audit_rate_limit) {
228 elapsed = now - last_check;
235 spin_unlock_irqrestore(&lock, flags);
241 * audit_log_lost - conditionally log lost audit message event
242 * @message: the message stating reason for lost audit message
244 * Emit at least 1 message per second, even if audit_rate_check is
246 * Always increment the lost messages counter.
248 void audit_log_lost(const char *message)
250 static unsigned long last_msg = 0;
251 static DEFINE_SPINLOCK(lock);
256 atomic_inc(&audit_lost);
258 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
261 spin_lock_irqsave(&lock, flags);
263 if (now - last_msg > HZ) {
267 spin_unlock_irqrestore(&lock, flags);
271 if (printk_ratelimit())
273 "audit: audit_lost=%d audit_rate_limit=%d "
274 "audit_backlog_limit=%d\n",
275 atomic_read(&audit_lost),
277 audit_backlog_limit);
278 audit_panic(message);
282 static int audit_log_config_change(char *function_name, int new, int old,
285 struct audit_buffer *ab;
288 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
291 audit_log_format(ab, "%s=%d old=%d", function_name, new, old);
292 audit_log_session_info(ab);
293 rc = audit_log_task_context(ab);
295 allow_changes = 0; /* Something weird, deny request */
296 audit_log_format(ab, " res=%d", allow_changes);
301 static int audit_do_config_change(char *function_name, int *to_change, int new)
303 int allow_changes, rc = 0, old = *to_change;
305 /* check if we are locked */
306 if (audit_enabled == AUDIT_LOCKED)
311 if (audit_enabled != AUDIT_OFF) {
312 rc = audit_log_config_change(function_name, new, old, allow_changes);
317 /* If we are allowed, make the change */
318 if (allow_changes == 1)
320 /* Not allowed, update reason */
326 static int audit_set_rate_limit(int limit)
328 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
331 static int audit_set_backlog_limit(int limit)
333 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
336 static int audit_set_enabled(int state)
339 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
342 rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
344 audit_ever_enabled |= !!state;
349 static int audit_set_failure(int state)
351 if (state != AUDIT_FAIL_SILENT
352 && state != AUDIT_FAIL_PRINTK
353 && state != AUDIT_FAIL_PANIC)
356 return audit_do_config_change("audit_failure", &audit_failure, state);
360 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
361 * already have been sent via prink/syslog and so if these messages are dropped
362 * it is not a huge concern since we already passed the audit_log_lost()
363 * notification and stuff. This is just nice to get audit messages during
364 * boot before auditd is running or messages generated while auditd is stopped.
365 * This only holds messages is audit_default is set, aka booting with audit=1
366 * or building your kernel that way.
368 static void audit_hold_skb(struct sk_buff *skb)
371 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
372 skb_queue_tail(&audit_skb_hold_queue, skb);
378 * For one reason or another this nlh isn't getting delivered to the userspace
379 * audit daemon, just send it to printk.
381 static void audit_printk_skb(struct sk_buff *skb)
383 struct nlmsghdr *nlh = nlmsg_hdr(skb);
384 char *data = nlmsg_data(nlh);
386 if (nlh->nlmsg_type != AUDIT_EOE) {
387 if (printk_ratelimit())
388 printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data);
390 audit_log_lost("printk limit exceeded\n");
396 static void kauditd_send_skb(struct sk_buff *skb)
399 /* take a reference in case we can't send it and we want to hold it */
401 err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
403 BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
404 printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
405 audit_log_lost("auditd disappeared\n");
408 /* we might get lucky and get this in the next auditd */
411 /* drop the extra reference if sent ok */
416 * flush_hold_queue - empty the hold queue if auditd appears
418 * If auditd just started, drain the queue of messages already
419 * sent to syslog/printk. Remember loss here is ok. We already
420 * called audit_log_lost() if it didn't go out normally. so the
421 * race between the skb_dequeue and the next check for audit_pid
424 * If you ever find kauditd to be too slow we can get a perf win
425 * by doing our own locking and keeping better track if there
426 * are messages in this queue. I don't see the need now, but
427 * in 5 years when I want to play with this again I'll see this
428 * note and still have no friggin idea what i'm thinking today.
430 static void flush_hold_queue(void)
434 if (!audit_default || !audit_pid)
437 skb = skb_dequeue(&audit_skb_hold_queue);
441 while (skb && audit_pid) {
442 kauditd_send_skb(skb);
443 skb = skb_dequeue(&audit_skb_hold_queue);
447 * if auditd just disappeared but we
448 * dequeued an skb we need to drop ref
454 static int kauditd_thread(void *dummy)
457 while (!kthread_should_stop()) {
459 DECLARE_WAITQUEUE(wait, current);
463 skb = skb_dequeue(&audit_skb_queue);
464 wake_up(&audit_backlog_wait);
467 kauditd_send_skb(skb);
469 audit_printk_skb(skb);
472 set_current_state(TASK_INTERRUPTIBLE);
473 add_wait_queue(&kauditd_wait, &wait);
475 if (!skb_queue_len(&audit_skb_queue)) {
480 __set_current_state(TASK_RUNNING);
481 remove_wait_queue(&kauditd_wait, &wait);
486 int audit_send_list(void *_dest)
488 struct audit_netlink_list *dest = _dest;
490 struct net *net = get_net_ns_by_pid(dest->pid);
491 struct audit_net *aunet = net_generic(net, audit_net_id);
493 /* wait for parent to finish and send an ACK */
494 mutex_lock(&audit_cmd_mutex);
495 mutex_unlock(&audit_cmd_mutex);
497 while ((skb = __skb_dequeue(&dest->q)) != NULL)
498 netlink_unicast(aunet->nlsk, skb, dest->portid, 0);
505 struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done,
506 int multi, const void *payload, int size)
509 struct nlmsghdr *nlh;
511 int flags = multi ? NLM_F_MULTI : 0;
512 int t = done ? NLMSG_DONE : type;
514 skb = nlmsg_new(size, GFP_KERNEL);
518 nlh = nlmsg_put(skb, portid, seq, t, size, flags);
521 data = nlmsg_data(nlh);
522 memcpy(data, payload, size);
530 static int audit_send_reply_thread(void *arg)
532 struct audit_reply *reply = (struct audit_reply *)arg;
533 struct net *net = get_net_ns_by_pid(reply->pid);
534 struct audit_net *aunet = net_generic(net, audit_net_id);
536 mutex_lock(&audit_cmd_mutex);
537 mutex_unlock(&audit_cmd_mutex);
539 /* Ignore failure. It'll only happen if the sender goes away,
540 because our timeout is set to infinite. */
541 netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0);
546 * audit_send_reply - send an audit reply message via netlink
547 * @portid: netlink port to which to send reply
548 * @seq: sequence number
549 * @type: audit message type
550 * @done: done (last) flag
551 * @multi: multi-part message flag
552 * @payload: payload data
553 * @size: payload size
555 * Allocates an skb, builds the netlink message, and sends it to the port id.
556 * No failure notifications.
558 static void audit_send_reply(__u32 portid, int seq, int type, int done,
559 int multi, const void *payload, int size)
562 struct task_struct *tsk;
563 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
569 skb = audit_make_reply(portid, seq, type, done, multi, payload, size);
573 reply->portid = portid;
574 reply->pid = task_pid_vnr(current);
577 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
586 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
589 static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
593 /* Only support the initial namespaces for now. */
594 if ((current_user_ns() != &init_user_ns) ||
595 (task_active_pid_ns(current) != &init_pid_ns))
605 case AUDIT_GET_FEATURE:
606 case AUDIT_SET_FEATURE:
607 case AUDIT_LIST_RULES:
610 case AUDIT_SIGNAL_INFO:
614 case AUDIT_MAKE_EQUIV:
615 if (!capable(CAP_AUDIT_CONTROL))
619 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
620 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
621 if (!capable(CAP_AUDIT_WRITE))
624 default: /* bad msg */
631 static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
634 uid_t uid = from_kuid(&init_user_ns, current_uid());
636 if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
641 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
644 audit_log_format(*ab, "pid=%d uid=%u", task_tgid_vnr(current), uid);
645 audit_log_session_info(*ab);
646 audit_log_task_context(*ab);
651 int is_audit_feature_set(int i)
653 return af.features & AUDIT_FEATURE_TO_MASK(i);
657 static int audit_get_feature(struct sk_buff *skb)
661 seq = nlmsg_hdr(skb)->nlmsg_seq;
663 audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0,
669 static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
670 u32 old_lock, u32 new_lock, int res)
672 struct audit_buffer *ab;
674 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE);
675 audit_log_format(ab, "feature=%s new=%d old=%d old_lock=%d new_lock=%d res=%d",
676 audit_feature_names[which], !!old_feature, !!new_feature,
677 !!old_lock, !!new_lock, res);
681 static int audit_set_feature(struct sk_buff *skb)
683 struct audit_features *uaf;
686 BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > sizeof(audit_feature_names)/sizeof(audit_feature_names[0]));
687 uaf = nlmsg_data(nlmsg_hdr(skb));
689 /* if there is ever a version 2 we should handle that here */
691 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
692 u32 feature = AUDIT_FEATURE_TO_MASK(i);
693 u32 old_feature, new_feature, old_lock, new_lock;
695 /* if we are not changing this feature, move along */
696 if (!(feature & uaf->mask))
699 old_feature = af.features & feature;
700 new_feature = uaf->features & feature;
701 new_lock = (uaf->lock | af.lock) & feature;
702 old_lock = af.lock & feature;
704 /* are we changing a locked feature? */
705 if ((af.lock & feature) && (new_feature != old_feature)) {
706 audit_log_feature_change(i, old_feature, new_feature,
707 old_lock, new_lock, 0);
711 /* nothing invalid, do the changes */
712 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
713 u32 feature = AUDIT_FEATURE_TO_MASK(i);
714 u32 old_feature, new_feature, old_lock, new_lock;
716 /* if we are not changing this feature, move along */
717 if (!(feature & uaf->mask))
720 old_feature = af.features & feature;
721 new_feature = uaf->features & feature;
722 old_lock = af.lock & feature;
723 new_lock = (uaf->lock | af.lock) & feature;
725 if (new_feature != old_feature)
726 audit_log_feature_change(i, old_feature, new_feature,
727 old_lock, new_lock, 1);
730 af.features |= feature;
732 af.features &= ~feature;
739 static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
743 struct audit_status *status_get, status_set;
745 struct audit_buffer *ab;
746 u16 msg_type = nlh->nlmsg_type;
747 struct audit_sig_info *sig_data;
751 err = audit_netlink_ok(skb, msg_type);
755 /* As soon as there's any sign of userspace auditd,
756 * start kauditd to talk to it */
758 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
759 if (IS_ERR(kauditd_task)) {
760 err = PTR_ERR(kauditd_task);
765 seq = nlh->nlmsg_seq;
766 data = nlmsg_data(nlh);
770 memset(&status_set, 0, sizeof(status_set));
771 status_set.enabled = audit_enabled;
772 status_set.failure = audit_failure;
773 status_set.pid = audit_pid;
774 status_set.rate_limit = audit_rate_limit;
775 status_set.backlog_limit = audit_backlog_limit;
776 status_set.lost = atomic_read(&audit_lost);
777 status_set.backlog = skb_queue_len(&audit_skb_queue);
778 audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0,
779 &status_set, sizeof(status_set));
782 if (nlmsg_len(nlh) < sizeof(struct audit_status))
784 status_get = (struct audit_status *)data;
785 if (status_get->mask & AUDIT_STATUS_ENABLED) {
786 err = audit_set_enabled(status_get->enabled);
790 if (status_get->mask & AUDIT_STATUS_FAILURE) {
791 err = audit_set_failure(status_get->failure);
795 if (status_get->mask & AUDIT_STATUS_PID) {
796 int new_pid = status_get->pid;
798 if (audit_enabled != AUDIT_OFF)
799 audit_log_config_change("audit_pid", new_pid, audit_pid, 1);
801 audit_nlk_portid = NETLINK_CB(skb).portid;
802 audit_sock = NETLINK_CB(skb).sk;
804 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
805 err = audit_set_rate_limit(status_get->rate_limit);
809 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
810 err = audit_set_backlog_limit(status_get->backlog_limit);
812 case AUDIT_GET_FEATURE:
813 err = audit_get_feature(skb);
817 case AUDIT_SET_FEATURE:
818 err = audit_set_feature(skb);
823 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
824 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
825 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
828 err = audit_filter_user(msg_type);
831 if (msg_type == AUDIT_USER_TTY) {
832 err = tty_audit_push_current();
836 audit_log_common_recv_msg(&ab, msg_type);
837 if (msg_type != AUDIT_USER_TTY)
838 audit_log_format(ab, " msg='%.*s'",
839 AUDIT_MESSAGE_TEXT_MAX,
844 audit_log_format(ab, " data=");
845 size = nlmsg_len(nlh);
847 ((unsigned char *)data)[size - 1] == '\0')
849 audit_log_n_untrustedstring(ab, data, size);
851 audit_set_portid(ab, NETLINK_CB(skb).portid);
857 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
859 if (audit_enabled == AUDIT_LOCKED) {
860 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
861 audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled);
866 case AUDIT_LIST_RULES:
867 err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid,
868 seq, data, nlmsg_len(nlh));
872 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
873 audit_log_format(ab, " op=trim res=1");
876 case AUDIT_MAKE_EQUIV: {
879 size_t msglen = nlmsg_len(nlh);
883 if (msglen < 2 * sizeof(u32))
885 memcpy(sizes, bufp, 2 * sizeof(u32));
886 bufp += 2 * sizeof(u32);
887 msglen -= 2 * sizeof(u32);
888 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
893 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
899 /* OK, here comes... */
900 err = audit_tag_tree(old, new);
902 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
904 audit_log_format(ab, " op=make_equiv old=");
905 audit_log_untrustedstring(ab, old);
906 audit_log_format(ab, " new=");
907 audit_log_untrustedstring(ab, new);
908 audit_log_format(ab, " res=%d", !err);
914 case AUDIT_SIGNAL_INFO:
917 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
921 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
924 security_release_secctx(ctx, len);
927 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
928 sig_data->pid = audit_sig_pid;
930 memcpy(sig_data->ctx, ctx, len);
931 security_release_secctx(ctx, len);
933 audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO,
934 0, 0, sig_data, sizeof(*sig_data) + len);
937 case AUDIT_TTY_GET: {
938 struct audit_tty_status s;
939 struct task_struct *tsk = current;
941 spin_lock(&tsk->sighand->siglock);
942 s.enabled = tsk->signal->audit_tty;
943 s.log_passwd = tsk->signal->audit_tty_log_passwd;
944 spin_unlock(&tsk->sighand->siglock);
946 audit_send_reply(NETLINK_CB(skb).portid, seq,
947 AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
950 case AUDIT_TTY_SET: {
951 struct audit_tty_status s;
952 struct task_struct *tsk = current;
954 memset(&s, 0, sizeof(s));
955 /* guard against past and future API changes */
956 memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
957 if ((s.enabled != 0 && s.enabled != 1) ||
958 (s.log_passwd != 0 && s.log_passwd != 1))
961 spin_lock(&tsk->sighand->siglock);
962 tsk->signal->audit_tty = s.enabled;
963 tsk->signal->audit_tty_log_passwd = s.log_passwd;
964 spin_unlock(&tsk->sighand->siglock);
972 return err < 0 ? err : 0;
976 * Get message from skb. Each message is processed by audit_receive_msg.
977 * Malformed skbs with wrong length are discarded silently.
979 static void audit_receive_skb(struct sk_buff *skb)
981 struct nlmsghdr *nlh;
983 * len MUST be signed for nlmsg_next to be able to dec it below 0
984 * if the nlmsg_len was not aligned
989 nlh = nlmsg_hdr(skb);
992 while (nlmsg_ok(nlh, len)) {
993 err = audit_receive_msg(skb, nlh);
994 /* if err or if this message says it wants a response */
995 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
996 netlink_ack(skb, nlh, err);
998 nlh = nlmsg_next(nlh, &len);
1002 /* Receive messages from netlink socket. */
1003 static void audit_receive(struct sk_buff *skb)
1005 mutex_lock(&audit_cmd_mutex);
1006 audit_receive_skb(skb);
1007 mutex_unlock(&audit_cmd_mutex);
1010 static int __net_init audit_net_init(struct net *net)
1012 struct netlink_kernel_cfg cfg = {
1013 .input = audit_receive,
1016 struct audit_net *aunet = net_generic(net, audit_net_id);
1018 pr_info("audit: initializing netlink socket in namespace\n");
1020 aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
1021 if (aunet->nlsk == NULL)
1024 audit_panic("cannot initialize netlink socket in namespace");
1026 aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
1030 static void __net_exit audit_net_exit(struct net *net)
1032 struct audit_net *aunet = net_generic(net, audit_net_id);
1033 struct sock *sock = aunet->nlsk;
1034 if (sock == audit_sock) {
1039 rcu_assign_pointer(aunet->nlsk, NULL);
1041 netlink_kernel_release(sock);
1044 static struct pernet_operations __net_initdata audit_net_ops = {
1045 .init = audit_net_init,
1046 .exit = audit_net_exit,
1047 .id = &audit_net_id,
1048 .size = sizeof(struct audit_net),
1051 /* Initialize audit support at boot time. */
1052 static int __init audit_init(void)
1056 if (audit_initialized == AUDIT_DISABLED)
1059 pr_info("audit: initializing netlink subsys (%s)\n",
1060 audit_default ? "enabled" : "disabled");
1061 register_pernet_subsys(&audit_net_ops);
1063 skb_queue_head_init(&audit_skb_queue);
1064 skb_queue_head_init(&audit_skb_hold_queue);
1065 audit_initialized = AUDIT_INITIALIZED;
1066 audit_enabled = audit_default;
1067 audit_ever_enabled |= !!audit_default;
1069 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
1071 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1072 INIT_LIST_HEAD(&audit_inode_hash[i]);
1076 __initcall(audit_init);
1078 /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1079 static int __init audit_enable(char *str)
1081 audit_default = !!simple_strtol(str, NULL, 0);
1083 audit_initialized = AUDIT_DISABLED;
1085 printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
1087 if (audit_initialized == AUDIT_INITIALIZED) {
1088 audit_enabled = audit_default;
1089 audit_ever_enabled |= !!audit_default;
1090 } else if (audit_initialized == AUDIT_UNINITIALIZED) {
1091 printk(" (after initialization)");
1093 printk(" (until reboot)");
1100 __setup("audit=", audit_enable);
1102 static void audit_buffer_free(struct audit_buffer *ab)
1104 unsigned long flags;
1112 spin_lock_irqsave(&audit_freelist_lock, flags);
1113 if (audit_freelist_count > AUDIT_MAXFREE)
1116 audit_freelist_count++;
1117 list_add(&ab->list, &audit_freelist);
1119 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1122 static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
1123 gfp_t gfp_mask, int type)
1125 unsigned long flags;
1126 struct audit_buffer *ab = NULL;
1127 struct nlmsghdr *nlh;
1129 spin_lock_irqsave(&audit_freelist_lock, flags);
1130 if (!list_empty(&audit_freelist)) {
1131 ab = list_entry(audit_freelist.next,
1132 struct audit_buffer, list);
1133 list_del(&ab->list);
1134 --audit_freelist_count;
1136 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1139 ab = kmalloc(sizeof(*ab), gfp_mask);
1145 ab->gfp_mask = gfp_mask;
1147 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1151 nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0);
1161 audit_buffer_free(ab);
1166 * audit_serial - compute a serial number for the audit record
1168 * Compute a serial number for the audit record. Audit records are
1169 * written to user-space as soon as they are generated, so a complete
1170 * audit record may be written in several pieces. The timestamp of the
1171 * record and this serial number are used by the user-space tools to
1172 * determine which pieces belong to the same audit record. The
1173 * (timestamp,serial) tuple is unique for each syscall and is live from
1174 * syscall entry to syscall exit.
1176 * NOTE: Another possibility is to store the formatted records off the
1177 * audit context (for those records that have a context), and emit them
1178 * all at syscall exit. However, this could delay the reporting of
1179 * significant errors until syscall exit (or never, if the system
1182 unsigned int audit_serial(void)
1184 static DEFINE_SPINLOCK(serial_lock);
1185 static unsigned int serial = 0;
1187 unsigned long flags;
1190 spin_lock_irqsave(&serial_lock, flags);
1193 } while (unlikely(!ret));
1194 spin_unlock_irqrestore(&serial_lock, flags);
1199 static inline void audit_get_stamp(struct audit_context *ctx,
1200 struct timespec *t, unsigned int *serial)
1202 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1204 *serial = audit_serial();
1209 * Wait for auditd to drain the queue a little
1211 static void wait_for_auditd(unsigned long sleep_time)
1213 DECLARE_WAITQUEUE(wait, current);
1214 set_current_state(TASK_UNINTERRUPTIBLE);
1215 add_wait_queue(&audit_backlog_wait, &wait);
1217 if (audit_backlog_limit &&
1218 skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
1219 schedule_timeout(sleep_time);
1221 __set_current_state(TASK_RUNNING);
1222 remove_wait_queue(&audit_backlog_wait, &wait);
1226 * audit_log_start - obtain an audit buffer
1227 * @ctx: audit_context (may be NULL)
1228 * @gfp_mask: type of allocation
1229 * @type: audit message type
1231 * Returns audit_buffer pointer on success or NULL on error.
1233 * Obtain an audit buffer. This routine does locking to obtain the
1234 * audit buffer, but then no locking is required for calls to
1235 * audit_log_*format. If the task (ctx) is a task that is currently in a
1236 * syscall, then the syscall is marked as auditable and an audit record
1237 * will be written at syscall exit. If there is no associated task, then
1238 * task context (ctx) should be NULL.
1240 struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1243 struct audit_buffer *ab = NULL;
1245 unsigned int uninitialized_var(serial);
1247 unsigned long timeout_start = jiffies;
1249 if (audit_initialized != AUDIT_INITIALIZED)
1252 if (unlikely(audit_filter_type(type)))
1255 if (gfp_mask & __GFP_WAIT)
1258 reserve = 5; /* Allow atomic callers to go up to five
1259 entries over the normal backlog limit */
1261 while (audit_backlog_limit
1262 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
1263 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) {
1264 unsigned long sleep_time;
1266 sleep_time = timeout_start + audit_backlog_wait_time -
1268 if ((long)sleep_time > 0) {
1269 wait_for_auditd(sleep_time);
1273 if (audit_rate_check() && printk_ratelimit())
1275 "audit: audit_backlog=%d > "
1276 "audit_backlog_limit=%d\n",
1277 skb_queue_len(&audit_skb_queue),
1278 audit_backlog_limit);
1279 audit_log_lost("backlog limit exceeded");
1280 audit_backlog_wait_time = audit_backlog_wait_overflow;
1281 wake_up(&audit_backlog_wait);
1285 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1287 audit_log_lost("out of memory in audit_log_start");
1291 audit_get_stamp(ab->ctx, &t, &serial);
1293 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1294 t.tv_sec, t.tv_nsec/1000000, serial);
1299 * audit_expand - expand skb in the audit buffer
1301 * @extra: space to add at tail of the skb
1303 * Returns 0 (no space) on failed expansion, or available space if
1306 static inline int audit_expand(struct audit_buffer *ab, int extra)
1308 struct sk_buff *skb = ab->skb;
1309 int oldtail = skb_tailroom(skb);
1310 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1311 int newtail = skb_tailroom(skb);
1314 audit_log_lost("out of memory in audit_expand");
1318 skb->truesize += newtail - oldtail;
1323 * Format an audit message into the audit buffer. If there isn't enough
1324 * room in the audit buffer, more room will be allocated and vsnprint
1325 * will be called a second time. Currently, we assume that a printk
1326 * can't format message larger than 1024 bytes, so we don't either.
1328 static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1332 struct sk_buff *skb;
1340 avail = skb_tailroom(skb);
1342 avail = audit_expand(ab, AUDIT_BUFSIZ);
1346 va_copy(args2, args);
1347 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1349 /* The printk buffer is 1024 bytes long, so if we get
1350 * here and AUDIT_BUFSIZ is at least 1024, then we can
1351 * log everything that printk could have logged. */
1352 avail = audit_expand(ab,
1353 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1356 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1367 * audit_log_format - format a message into the audit buffer.
1369 * @fmt: format string
1370 * @...: optional parameters matching @fmt string
1372 * All the work is done in audit_log_vformat.
1374 void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1380 va_start(args, fmt);
1381 audit_log_vformat(ab, fmt, args);
1386 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1387 * @ab: the audit_buffer
1388 * @buf: buffer to convert to hex
1389 * @len: length of @buf to be converted
1391 * No return value; failure to expand is silently ignored.
1393 * This function will take the passed buf and convert it into a string of
1394 * ascii hex digits. The new string is placed onto the skb.
1396 void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1399 int i, avail, new_len;
1401 struct sk_buff *skb;
1402 static const unsigned char *hex = "0123456789ABCDEF";
1409 avail = skb_tailroom(skb);
1411 if (new_len >= avail) {
1412 /* Round the buffer request up to the next multiple */
1413 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1414 avail = audit_expand(ab, new_len);
1419 ptr = skb_tail_pointer(skb);
1420 for (i=0; i<len; i++) {
1421 *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
1422 *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */
1425 skb_put(skb, len << 1); /* new string is twice the old string */
1429 * Format a string of no more than slen characters into the audit buffer,
1430 * enclosed in quote marks.
1432 void audit_log_n_string(struct audit_buffer *ab, const char *string,
1437 struct sk_buff *skb;
1444 avail = skb_tailroom(skb);
1445 new_len = slen + 3; /* enclosing quotes + null terminator */
1446 if (new_len > avail) {
1447 avail = audit_expand(ab, new_len);
1451 ptr = skb_tail_pointer(skb);
1453 memcpy(ptr, string, slen);
1457 skb_put(skb, slen + 2); /* don't include null terminator */
1461 * audit_string_contains_control - does a string need to be logged in hex
1462 * @string: string to be checked
1463 * @len: max length of the string to check
1465 int audit_string_contains_control(const char *string, size_t len)
1467 const unsigned char *p;
1468 for (p = string; p < (const unsigned char *)string + len; p++) {
1469 if (*p == '"' || *p < 0x21 || *p > 0x7e)
1476 * audit_log_n_untrustedstring - log a string that may contain random characters
1478 * @len: length of string (not including trailing null)
1479 * @string: string to be logged
1481 * This code will escape a string that is passed to it if the string
1482 * contains a control character, unprintable character, double quote mark,
1483 * or a space. Unescaped strings will start and end with a double quote mark.
1484 * Strings that are escaped are printed in hex (2 digits per char).
1486 * The caller specifies the number of characters in the string to log, which may
1487 * or may not be the entire string.
1489 void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1492 if (audit_string_contains_control(string, len))
1493 audit_log_n_hex(ab, string, len);
1495 audit_log_n_string(ab, string, len);
1499 * audit_log_untrustedstring - log a string that may contain random characters
1501 * @string: string to be logged
1503 * Same as audit_log_n_untrustedstring(), except that strlen is used to
1504 * determine string length.
1506 void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
1508 audit_log_n_untrustedstring(ab, string, strlen(string));
1511 /* This is a helper-function to print the escaped d_path */
1512 void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
1513 const struct path *path)
1518 audit_log_format(ab, "%s", prefix);
1520 /* We will allow 11 spaces for ' (deleted)' to be appended */
1521 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1523 audit_log_string(ab, "<no_memory>");
1526 p = d_path(path, pathname, PATH_MAX+11);
1527 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1528 /* FIXME: can we save some information here? */
1529 audit_log_string(ab, "<too_long>");
1531 audit_log_untrustedstring(ab, p);
1535 void audit_log_session_info(struct audit_buffer *ab)
1537 u32 sessionid = audit_get_sessionid(current);
1538 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1540 audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
1543 void audit_log_key(struct audit_buffer *ab, char *key)
1545 audit_log_format(ab, " key=");
1547 audit_log_untrustedstring(ab, key);
1549 audit_log_format(ab, "(null)");
1552 void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
1556 audit_log_format(ab, " %s=", prefix);
1557 CAP_FOR_EACH_U32(i) {
1558 audit_log_format(ab, "%08x",
1559 cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]);
1563 void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
1565 kernel_cap_t *perm = &name->fcap.permitted;
1566 kernel_cap_t *inh = &name->fcap.inheritable;
1569 if (!cap_isclear(*perm)) {
1570 audit_log_cap(ab, "cap_fp", perm);
1573 if (!cap_isclear(*inh)) {
1574 audit_log_cap(ab, "cap_fi", inh);
1579 audit_log_format(ab, " cap_fe=%d cap_fver=%x",
1580 name->fcap.fE, name->fcap_ver);
1583 static inline int audit_copy_fcaps(struct audit_names *name,
1584 const struct dentry *dentry)
1586 struct cpu_vfs_cap_data caps;
1592 rc = get_vfs_caps_from_disk(dentry, &caps);
1596 name->fcap.permitted = caps.permitted;
1597 name->fcap.inheritable = caps.inheritable;
1598 name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
1599 name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >>
1600 VFS_CAP_REVISION_SHIFT;
1605 /* Copy inode data into an audit_names. */
1606 void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
1607 const struct inode *inode)
1609 name->ino = inode->i_ino;
1610 name->dev = inode->i_sb->s_dev;
1611 name->mode = inode->i_mode;
1612 name->uid = inode->i_uid;
1613 name->gid = inode->i_gid;
1614 name->rdev = inode->i_rdev;
1615 security_inode_getsecid(inode, &name->osid);
1616 audit_copy_fcaps(name, dentry);
1620 * audit_log_name - produce AUDIT_PATH record from struct audit_names
1621 * @context: audit_context for the task
1622 * @n: audit_names structure with reportable details
1623 * @path: optional path to report instead of audit_names->name
1624 * @record_num: record number to report when handling a list of names
1625 * @call_panic: optional pointer to int that will be updated if secid fails
1627 void audit_log_name(struct audit_context *context, struct audit_names *n,
1628 struct path *path, int record_num, int *call_panic)
1630 struct audit_buffer *ab;
1631 ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
1635 audit_log_format(ab, "item=%d", record_num);
1638 audit_log_d_path(ab, " name=", path);
1640 switch (n->name_len) {
1641 case AUDIT_NAME_FULL:
1642 /* log the full path */
1643 audit_log_format(ab, " name=");
1644 audit_log_untrustedstring(ab, n->name->name);
1647 /* name was specified as a relative path and the
1648 * directory component is the cwd */
1649 audit_log_d_path(ab, " name=", &context->pwd);
1652 /* log the name's directory component */
1653 audit_log_format(ab, " name=");
1654 audit_log_n_untrustedstring(ab, n->name->name,
1658 audit_log_format(ab, " name=(null)");
1660 if (n->ino != (unsigned long)-1) {
1661 audit_log_format(ab, " inode=%lu"
1662 " dev=%02x:%02x mode=%#ho"
1663 " ouid=%u ogid=%u rdev=%02x:%02x",
1668 from_kuid(&init_user_ns, n->uid),
1669 from_kgid(&init_user_ns, n->gid),
1676 if (security_secid_to_secctx(
1677 n->osid, &ctx, &len)) {
1678 audit_log_format(ab, " osid=%u", n->osid);
1682 audit_log_format(ab, " obj=%s", ctx);
1683 security_release_secctx(ctx, len);
1687 /* log the audit_names record type */
1688 audit_log_format(ab, " nametype=");
1690 case AUDIT_TYPE_NORMAL:
1691 audit_log_format(ab, "NORMAL");
1693 case AUDIT_TYPE_PARENT:
1694 audit_log_format(ab, "PARENT");
1696 case AUDIT_TYPE_CHILD_DELETE:
1697 audit_log_format(ab, "DELETE");
1699 case AUDIT_TYPE_CHILD_CREATE:
1700 audit_log_format(ab, "CREATE");
1703 audit_log_format(ab, "UNKNOWN");
1707 audit_log_fcaps(ab, n);
1711 int audit_log_task_context(struct audit_buffer *ab)
1718 security_task_getsecid(current, &sid);
1722 error = security_secid_to_secctx(sid, &ctx, &len);
1724 if (error != -EINVAL)
1729 audit_log_format(ab, " subj=%s", ctx);
1730 security_release_secctx(ctx, len);
1734 audit_panic("error in audit_log_task_context");
1737 EXPORT_SYMBOL(audit_log_task_context);
1739 void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
1741 const struct cred *cred;
1742 char name[sizeof(tsk->comm)];
1743 struct mm_struct *mm = tsk->mm;
1749 /* tsk == current */
1750 cred = current_cred();
1752 spin_lock_irq(&tsk->sighand->siglock);
1753 if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
1754 tty = tsk->signal->tty->name;
1757 spin_unlock_irq(&tsk->sighand->siglock);
1759 audit_log_format(ab,
1760 " ppid=%ld pid=%d auid=%u uid=%u gid=%u"
1761 " euid=%u suid=%u fsuid=%u"
1762 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
1765 from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
1766 from_kuid(&init_user_ns, cred->uid),
1767 from_kgid(&init_user_ns, cred->gid),
1768 from_kuid(&init_user_ns, cred->euid),
1769 from_kuid(&init_user_ns, cred->suid),
1770 from_kuid(&init_user_ns, cred->fsuid),
1771 from_kgid(&init_user_ns, cred->egid),
1772 from_kgid(&init_user_ns, cred->sgid),
1773 from_kgid(&init_user_ns, cred->fsgid),
1774 tty, audit_get_sessionid(tsk));
1776 get_task_comm(name, tsk);
1777 audit_log_format(ab, " comm=");
1778 audit_log_untrustedstring(ab, name);
1781 down_read(&mm->mmap_sem);
1783 audit_log_d_path(ab, " exe=", &mm->exe_file->f_path);
1784 up_read(&mm->mmap_sem);
1786 audit_log_task_context(ab);
1788 EXPORT_SYMBOL(audit_log_task_info);
1791 * audit_log_link_denied - report a link restriction denial
1792 * @operation: specific link opreation
1793 * @link: the path that triggered the restriction
1795 void audit_log_link_denied(const char *operation, struct path *link)
1797 struct audit_buffer *ab;
1798 struct audit_names *name;
1800 name = kzalloc(sizeof(*name), GFP_NOFS);
1804 /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
1805 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1809 audit_log_format(ab, "op=%s", operation);
1810 audit_log_task_info(ab, current);
1811 audit_log_format(ab, " res=0");
1814 /* Generate AUDIT_PATH record with object. */
1815 name->type = AUDIT_TYPE_NORMAL;
1816 audit_copy_inode(name, link->dentry, link->dentry->d_inode);
1817 audit_log_name(current->audit_context, name, link, 0, NULL);
1823 * audit_log_end - end one audit record
1824 * @ab: the audit_buffer
1826 * The netlink_* functions cannot be called inside an irq context, so
1827 * the audit buffer is placed on a queue and a tasklet is scheduled to
1828 * remove them from the queue outside the irq context. May be called in
1831 void audit_log_end(struct audit_buffer *ab)
1835 if (!audit_rate_check()) {
1836 audit_log_lost("rate limit exceeded");
1838 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
1839 nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN;
1842 skb_queue_tail(&audit_skb_queue, ab->skb);
1843 wake_up_interruptible(&kauditd_wait);
1845 audit_printk_skb(ab->skb);
1849 audit_buffer_free(ab);
1853 * audit_log - Log an audit record
1854 * @ctx: audit context
1855 * @gfp_mask: type of allocation
1856 * @type: audit message type
1857 * @fmt: format string to use
1858 * @...: variable parameters matching the format string
1860 * This is a convenience function that calls audit_log_start,
1861 * audit_log_vformat, and audit_log_end. It may be called
1864 void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
1865 const char *fmt, ...)
1867 struct audit_buffer *ab;
1870 ab = audit_log_start(ctx, gfp_mask, type);
1872 va_start(args, fmt);
1873 audit_log_vformat(ab, fmt, args);
1879 #ifdef CONFIG_SECURITY
1881 * audit_log_secctx - Converts and logs SELinux context
1883 * @secid: security number
1885 * This is a helper function that calls security_secid_to_secctx to convert
1886 * secid to secctx and then adds the (converted) SELinux context to the audit
1887 * log by calling audit_log_format, thus also preventing leak of internal secid
1888 * to userspace. If secid cannot be converted audit_panic is called.
1890 void audit_log_secctx(struct audit_buffer *ab, u32 secid)
1895 if (security_secid_to_secctx(secid, &secctx, &len)) {
1896 audit_panic("Cannot convert secid to context");
1898 audit_log_format(ab, " obj=%s", secctx);
1899 security_release_secctx(secctx, len);
1902 EXPORT_SYMBOL(audit_log_secctx);
1905 EXPORT_SYMBOL(audit_log_start);
1906 EXPORT_SYMBOL(audit_log_end);
1907 EXPORT_SYMBOL(audit_log_format);
1908 EXPORT_SYMBOL(audit_log);