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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
46 #include <linux/file.h>
47 #include <linux/init.h>
48 #include <linux/types.h>
49 #include <linux/atomic.h>
51 #include <linux/export.h>
52 #include <linux/slab.h>
53 #include <linux/err.h>
54 #include <linux/kthread.h>
55 #include <linux/kernel.h>
56 #include <linux/syscalls.h>
58 #include <linux/audit.h>
61 #include <net/netlink.h>
62 #include <linux/skbuff.h>
63 #ifdef CONFIG_SECURITY
64 #include <linux/security.h>
66 #include <linux/freezer.h>
67 #include <linux/tty.h>
68 #include <linux/pid_namespace.h>
69 #include <net/netns/generic.h>
73 /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
74 * (Initialization happens after skb_init is called.) */
75 #define AUDIT_DISABLED -1
76 #define AUDIT_UNINITIALIZED 0
77 #define AUDIT_INITIALIZED 1
78 static int audit_initialized;
82 #define AUDIT_LOCKED 2
84 u32 audit_ever_enabled;
86 EXPORT_SYMBOL_GPL(audit_enabled);
88 /* Default state when kernel boots without any parameters. */
89 static u32 audit_default;
91 /* If auditing cannot proceed, audit_failure selects what happens. */
92 static u32 audit_failure = AUDIT_FAIL_PRINTK;
95 * If audit records are to be written to the netlink socket, audit_pid
96 * contains the pid of the auditd process and audit_nlk_portid contains
97 * the portid to use to send netlink messages to that process.
100 static __u32 audit_nlk_portid;
102 /* If audit_rate_limit is non-zero, limit the rate of sending audit records
103 * to that number per second. This prevents DoS attacks, but results in
104 * audit records being dropped. */
105 static u32 audit_rate_limit;
107 /* Number of outstanding audit_buffers allowed.
108 * When set to zero, this means unlimited. */
109 static u32 audit_backlog_limit = 64;
110 #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
111 static u32 audit_backlog_wait_time_master = AUDIT_BACKLOG_WAIT_TIME;
112 static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
113 static u32 audit_backlog_wait_overflow = 0;
115 /* The identity of the user shutting down the audit system. */
116 kuid_t audit_sig_uid = INVALID_UID;
117 pid_t audit_sig_pid = -1;
118 u32 audit_sig_sid = 0;
120 /* Records can be lost in several ways:
121 0) [suppressed in audit_alloc]
122 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
123 2) out of memory in audit_log_move [alloc_skb]
124 3) suppressed due to audit_rate_limit
125 4) suppressed due to audit_backlog_limit
127 static atomic_t audit_lost = ATOMIC_INIT(0);
129 /* The netlink socket. */
130 static struct sock *audit_sock;
131 static int audit_net_id;
133 /* Hash for inode-based rules */
134 struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
136 /* The audit_freelist is a list of pre-allocated audit buffers (if more
137 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
138 * being placed on the freelist). */
139 static DEFINE_SPINLOCK(audit_freelist_lock);
140 static int audit_freelist_count;
141 static LIST_HEAD(audit_freelist);
143 static struct sk_buff_head audit_skb_queue;
144 /* queue of skbs to send to auditd when/if it comes back */
145 static struct sk_buff_head audit_skb_hold_queue;
146 static struct task_struct *kauditd_task;
147 static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
148 static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
150 static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
155 static char *audit_feature_names[2] = {
156 "only_unset_loginuid",
157 "loginuid_immutable",
161 /* Serialize requests from userspace. */
162 DEFINE_MUTEX(audit_cmd_mutex);
164 /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
165 * audit records. Since printk uses a 1024 byte buffer, this buffer
166 * should be at least that large. */
167 #define AUDIT_BUFSIZ 1024
169 /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
170 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
171 #define AUDIT_MAXFREE (2*NR_CPUS)
173 /* The audit_buffer is used when formatting an audit record. The caller
174 * locks briefly to get the record off the freelist or to allocate the
175 * buffer, and locks briefly to send the buffer to the netlink layer or
176 * to place it on a transmit queue. Multiple audit_buffers can be in
177 * use simultaneously. */
178 struct audit_buffer {
179 struct list_head list;
180 struct sk_buff *skb; /* formatted skb ready to send */
181 struct audit_context *ctx; /* NULL or associated context */
191 static void audit_set_portid(struct audit_buffer *ab, __u32 portid)
194 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
195 nlh->nlmsg_pid = portid;
199 void audit_panic(const char *message)
201 switch (audit_failure) {
202 case AUDIT_FAIL_SILENT:
204 case AUDIT_FAIL_PRINTK:
205 if (printk_ratelimit())
206 pr_err("%s\n", message);
208 case AUDIT_FAIL_PANIC:
209 /* test audit_pid since printk is always losey, why bother? */
211 panic("audit: %s\n", message);
216 static inline int audit_rate_check(void)
218 static unsigned long last_check = 0;
219 static int messages = 0;
220 static DEFINE_SPINLOCK(lock);
223 unsigned long elapsed;
226 if (!audit_rate_limit) return 1;
228 spin_lock_irqsave(&lock, flags);
229 if (++messages < audit_rate_limit) {
233 elapsed = now - last_check;
240 spin_unlock_irqrestore(&lock, flags);
246 * audit_log_lost - conditionally log lost audit message event
247 * @message: the message stating reason for lost audit message
249 * Emit at least 1 message per second, even if audit_rate_check is
251 * Always increment the lost messages counter.
253 void audit_log_lost(const char *message)
255 static unsigned long last_msg = 0;
256 static DEFINE_SPINLOCK(lock);
261 atomic_inc(&audit_lost);
263 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
266 spin_lock_irqsave(&lock, flags);
268 if (now - last_msg > HZ) {
272 spin_unlock_irqrestore(&lock, flags);
276 if (printk_ratelimit())
277 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
278 atomic_read(&audit_lost),
280 audit_backlog_limit);
281 audit_panic(message);
285 static int audit_log_config_change(char *function_name, u32 new, u32 old,
288 struct audit_buffer *ab;
291 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
294 audit_log_format(ab, "%s=%u old=%u", function_name, new, old);
295 audit_log_session_info(ab);
296 rc = audit_log_task_context(ab);
298 allow_changes = 0; /* Something weird, deny request */
299 audit_log_format(ab, " res=%d", allow_changes);
304 static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
306 int allow_changes, rc = 0;
307 u32 old = *to_change;
309 /* check if we are locked */
310 if (audit_enabled == AUDIT_LOCKED)
315 if (audit_enabled != AUDIT_OFF) {
316 rc = audit_log_config_change(function_name, new, old, allow_changes);
321 /* If we are allowed, make the change */
322 if (allow_changes == 1)
324 /* Not allowed, update reason */
330 static int audit_set_rate_limit(u32 limit)
332 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
335 static int audit_set_backlog_limit(u32 limit)
337 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
340 static int audit_set_backlog_wait_time(u32 timeout)
342 return audit_do_config_change("audit_backlog_wait_time",
343 &audit_backlog_wait_time_master, timeout);
346 static int audit_set_enabled(u32 state)
349 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
352 rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
354 audit_ever_enabled |= !!state;
359 static int audit_set_failure(u32 state)
361 if (state != AUDIT_FAIL_SILENT
362 && state != AUDIT_FAIL_PRINTK
363 && state != AUDIT_FAIL_PANIC)
366 return audit_do_config_change("audit_failure", &audit_failure, state);
370 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
371 * already have been sent via prink/syslog and so if these messages are dropped
372 * it is not a huge concern since we already passed the audit_log_lost()
373 * notification and stuff. This is just nice to get audit messages during
374 * boot before auditd is running or messages generated while auditd is stopped.
375 * This only holds messages is audit_default is set, aka booting with audit=1
376 * or building your kernel that way.
378 static void audit_hold_skb(struct sk_buff *skb)
381 (!audit_backlog_limit ||
382 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit))
383 skb_queue_tail(&audit_skb_hold_queue, skb);
389 * For one reason or another this nlh isn't getting delivered to the userspace
390 * audit daemon, just send it to printk.
392 static void audit_printk_skb(struct sk_buff *skb)
394 struct nlmsghdr *nlh = nlmsg_hdr(skb);
395 char *data = nlmsg_data(nlh);
397 if (nlh->nlmsg_type != AUDIT_EOE) {
398 if (printk_ratelimit())
399 pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
401 audit_log_lost("printk limit exceeded");
407 static void kauditd_send_skb(struct sk_buff *skb)
410 /* take a reference in case we can't send it and we want to hold it */
412 err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
414 BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
416 pr_err("*NO* daemon at audit_pid=%d\n", audit_pid);
417 audit_log_lost("auditd disappeared");
421 /* we might get lucky and get this in the next auditd */
424 /* drop the extra reference if sent ok */
429 * kauditd_send_multicast_skb - send the skb to multicast userspace listeners
431 * This function doesn't consume an skb as might be expected since it has to
434 static void kauditd_send_multicast_skb(struct sk_buff *skb, gfp_t gfp_mask)
436 struct sk_buff *copy;
437 struct audit_net *aunet = net_generic(&init_net, audit_net_id);
438 struct sock *sock = aunet->nlsk;
440 if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
444 * The seemingly wasteful skb_copy() rather than bumping the refcount
445 * using skb_get() is necessary because non-standard mods are made to
446 * the skb by the original kaudit unicast socket send routine. The
447 * existing auditd daemon assumes this breakage. Fixing this would
448 * require co-ordinating a change in the established protocol between
449 * the kaudit kernel subsystem and the auditd userspace code. There is
450 * no reason for new multicast clients to continue with this
453 copy = skb_copy(skb, gfp_mask);
457 nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, gfp_mask);
461 * flush_hold_queue - empty the hold queue if auditd appears
463 * If auditd just started, drain the queue of messages already
464 * sent to syslog/printk. Remember loss here is ok. We already
465 * called audit_log_lost() if it didn't go out normally. so the
466 * race between the skb_dequeue and the next check for audit_pid
469 * If you ever find kauditd to be too slow we can get a perf win
470 * by doing our own locking and keeping better track if there
471 * are messages in this queue. I don't see the need now, but
472 * in 5 years when I want to play with this again I'll see this
473 * note and still have no friggin idea what i'm thinking today.
475 static void flush_hold_queue(void)
479 if (!audit_default || !audit_pid)
482 skb = skb_dequeue(&audit_skb_hold_queue);
486 while (skb && audit_pid) {
487 kauditd_send_skb(skb);
488 skb = skb_dequeue(&audit_skb_hold_queue);
492 * if auditd just disappeared but we
493 * dequeued an skb we need to drop ref
499 static int kauditd_thread(void *dummy)
502 while (!kthread_should_stop()) {
504 DECLARE_WAITQUEUE(wait, current);
508 skb = skb_dequeue(&audit_skb_queue);
511 if (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit)
512 wake_up(&audit_backlog_wait);
514 kauditd_send_skb(skb);
516 audit_printk_skb(skb);
519 set_current_state(TASK_INTERRUPTIBLE);
520 add_wait_queue(&kauditd_wait, &wait);
522 if (!skb_queue_len(&audit_skb_queue)) {
527 __set_current_state(TASK_RUNNING);
528 remove_wait_queue(&kauditd_wait, &wait);
533 int audit_send_list(void *_dest)
535 struct audit_netlink_list *dest = _dest;
537 struct net *net = dest->net;
538 struct audit_net *aunet = net_generic(net, audit_net_id);
540 /* wait for parent to finish and send an ACK */
541 mutex_lock(&audit_cmd_mutex);
542 mutex_unlock(&audit_cmd_mutex);
544 while ((skb = __skb_dequeue(&dest->q)) != NULL)
545 netlink_unicast(aunet->nlsk, skb, dest->portid, 0);
553 struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done,
554 int multi, const void *payload, int size)
557 struct nlmsghdr *nlh;
559 int flags = multi ? NLM_F_MULTI : 0;
560 int t = done ? NLMSG_DONE : type;
562 skb = nlmsg_new(size, GFP_KERNEL);
566 nlh = nlmsg_put(skb, portid, seq, t, size, flags);
569 data = nlmsg_data(nlh);
570 memcpy(data, payload, size);
578 static int audit_send_reply_thread(void *arg)
580 struct audit_reply *reply = (struct audit_reply *)arg;
581 struct net *net = reply->net;
582 struct audit_net *aunet = net_generic(net, audit_net_id);
584 mutex_lock(&audit_cmd_mutex);
585 mutex_unlock(&audit_cmd_mutex);
587 /* Ignore failure. It'll only happen if the sender goes away,
588 because our timeout is set to infinite. */
589 netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0);
595 * audit_send_reply - send an audit reply message via netlink
596 * @request_skb: skb of request we are replying to (used to target the reply)
597 * @seq: sequence number
598 * @type: audit message type
599 * @done: done (last) flag
600 * @multi: multi-part message flag
601 * @payload: payload data
602 * @size: payload size
604 * Allocates an skb, builds the netlink message, and sends it to the port id.
605 * No failure notifications.
607 static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
608 int multi, const void *payload, int size)
610 u32 portid = NETLINK_CB(request_skb).portid;
611 struct net *net = sock_net(NETLINK_CB(request_skb).sk);
613 struct task_struct *tsk;
614 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
620 skb = audit_make_reply(portid, seq, type, done, multi, payload, size);
624 reply->net = get_net(net);
625 reply->portid = portid;
628 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
637 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
640 static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
644 /* Only support initial user namespace for now. */
646 * We return ECONNREFUSED because it tricks userspace into thinking
647 * that audit was not configured into the kernel. Lots of users
648 * configure their PAM stack (because that's what the distro does)
649 * to reject login if unable to send messages to audit. If we return
650 * ECONNREFUSED the PAM stack thinks the kernel does not have audit
651 * configured in and will let login proceed. If we return EPERM
652 * userspace will reject all logins. This should be removed when we
653 * support non init namespaces!!
655 if (current_user_ns() != &init_user_ns)
656 return -ECONNREFUSED;
665 case AUDIT_GET_FEATURE:
666 case AUDIT_SET_FEATURE:
667 case AUDIT_LIST_RULES:
670 case AUDIT_SIGNAL_INFO:
674 case AUDIT_MAKE_EQUIV:
675 /* Only support auditd and auditctl in initial pid namespace
677 if (task_active_pid_ns(current) != &init_pid_ns)
680 if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
684 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
685 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
686 if (!netlink_capable(skb, CAP_AUDIT_WRITE))
689 default: /* bad msg */
696 static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
699 uid_t uid = from_kuid(&init_user_ns, current_uid());
700 pid_t pid = task_tgid_nr(current);
702 if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
707 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
710 audit_log_format(*ab, "pid=%d uid=%u", pid, uid);
711 audit_log_session_info(*ab);
712 audit_log_task_context(*ab);
717 int is_audit_feature_set(int i)
719 return af.features & AUDIT_FEATURE_TO_MASK(i);
723 static int audit_get_feature(struct sk_buff *skb)
727 seq = nlmsg_hdr(skb)->nlmsg_seq;
729 audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
734 static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
735 u32 old_lock, u32 new_lock, int res)
737 struct audit_buffer *ab;
739 if (audit_enabled == AUDIT_OFF)
742 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE);
743 audit_log_task_info(ab, current);
744 audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
745 audit_feature_names[which], !!old_feature, !!new_feature,
746 !!old_lock, !!new_lock, res);
750 static int audit_set_feature(struct sk_buff *skb)
752 struct audit_features *uaf;
755 BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
756 uaf = nlmsg_data(nlmsg_hdr(skb));
758 /* if there is ever a version 2 we should handle that here */
760 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
761 u32 feature = AUDIT_FEATURE_TO_MASK(i);
762 u32 old_feature, new_feature, old_lock, new_lock;
764 /* if we are not changing this feature, move along */
765 if (!(feature & uaf->mask))
768 old_feature = af.features & feature;
769 new_feature = uaf->features & feature;
770 new_lock = (uaf->lock | af.lock) & feature;
771 old_lock = af.lock & feature;
773 /* are we changing a locked feature? */
774 if (old_lock && (new_feature != old_feature)) {
775 audit_log_feature_change(i, old_feature, new_feature,
776 old_lock, new_lock, 0);
780 /* nothing invalid, do the changes */
781 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
782 u32 feature = AUDIT_FEATURE_TO_MASK(i);
783 u32 old_feature, new_feature, old_lock, new_lock;
785 /* if we are not changing this feature, move along */
786 if (!(feature & uaf->mask))
789 old_feature = af.features & feature;
790 new_feature = uaf->features & feature;
791 old_lock = af.lock & feature;
792 new_lock = (uaf->lock | af.lock) & feature;
794 if (new_feature != old_feature)
795 audit_log_feature_change(i, old_feature, new_feature,
796 old_lock, new_lock, 1);
799 af.features |= feature;
801 af.features &= ~feature;
808 static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
813 struct audit_buffer *ab;
814 u16 msg_type = nlh->nlmsg_type;
815 struct audit_sig_info *sig_data;
819 err = audit_netlink_ok(skb, msg_type);
823 /* As soon as there's any sign of userspace auditd,
824 * start kauditd to talk to it */
826 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
827 if (IS_ERR(kauditd_task)) {
828 err = PTR_ERR(kauditd_task);
833 seq = nlh->nlmsg_seq;
834 data = nlmsg_data(nlh);
838 struct audit_status s;
839 memset(&s, 0, sizeof(s));
840 s.enabled = audit_enabled;
841 s.failure = audit_failure;
843 s.rate_limit = audit_rate_limit;
844 s.backlog_limit = audit_backlog_limit;
845 s.lost = atomic_read(&audit_lost);
846 s.backlog = skb_queue_len(&audit_skb_queue);
847 s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
848 s.backlog_wait_time = audit_backlog_wait_time_master;
849 audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
853 struct audit_status s;
854 memset(&s, 0, sizeof(s));
855 /* guard against past and future API changes */
856 memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
857 if (s.mask & AUDIT_STATUS_ENABLED) {
858 err = audit_set_enabled(s.enabled);
862 if (s.mask & AUDIT_STATUS_FAILURE) {
863 err = audit_set_failure(s.failure);
867 if (s.mask & AUDIT_STATUS_PID) {
870 if ((!new_pid) && (task_tgid_vnr(current) != audit_pid))
872 if (audit_enabled != AUDIT_OFF)
873 audit_log_config_change("audit_pid", new_pid, audit_pid, 1);
875 audit_nlk_portid = NETLINK_CB(skb).portid;
876 audit_sock = skb->sk;
878 if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
879 err = audit_set_rate_limit(s.rate_limit);
883 if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
884 err = audit_set_backlog_limit(s.backlog_limit);
888 if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
889 if (sizeof(s) > (size_t)nlh->nlmsg_len)
891 if (s.backlog_wait_time < 0 ||
892 s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
894 err = audit_set_backlog_wait_time(s.backlog_wait_time);
900 case AUDIT_GET_FEATURE:
901 err = audit_get_feature(skb);
905 case AUDIT_SET_FEATURE:
906 err = audit_set_feature(skb);
911 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
912 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
913 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
916 err = audit_filter_user(msg_type);
917 if (err == 1) { /* match or error */
919 if (msg_type == AUDIT_USER_TTY) {
920 err = tty_audit_push_current();
924 mutex_unlock(&audit_cmd_mutex);
925 audit_log_common_recv_msg(&ab, msg_type);
926 if (msg_type != AUDIT_USER_TTY)
927 audit_log_format(ab, " msg='%.*s'",
928 AUDIT_MESSAGE_TEXT_MAX,
933 audit_log_format(ab, " data=");
934 size = nlmsg_len(nlh);
936 ((unsigned char *)data)[size - 1] == '\0')
938 audit_log_n_untrustedstring(ab, data, size);
940 audit_set_portid(ab, NETLINK_CB(skb).portid);
942 mutex_lock(&audit_cmd_mutex);
947 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
949 if (audit_enabled == AUDIT_LOCKED) {
950 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
951 audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled);
955 err = audit_rule_change(msg_type, NETLINK_CB(skb).portid,
956 seq, data, nlmsg_len(nlh));
958 case AUDIT_LIST_RULES:
959 err = audit_list_rules_send(skb, seq);
963 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
964 audit_log_format(ab, " op=trim res=1");
967 case AUDIT_MAKE_EQUIV: {
970 size_t msglen = nlmsg_len(nlh);
974 if (msglen < 2 * sizeof(u32))
976 memcpy(sizes, bufp, 2 * sizeof(u32));
977 bufp += 2 * sizeof(u32);
978 msglen -= 2 * sizeof(u32);
979 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
984 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
990 /* OK, here comes... */
991 err = audit_tag_tree(old, new);
993 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
995 audit_log_format(ab, " op=make_equiv old=");
996 audit_log_untrustedstring(ab, old);
997 audit_log_format(ab, " new=");
998 audit_log_untrustedstring(ab, new);
999 audit_log_format(ab, " res=%d", !err);
1005 case AUDIT_SIGNAL_INFO:
1007 if (audit_sig_sid) {
1008 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
1012 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
1015 security_release_secctx(ctx, len);
1018 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
1019 sig_data->pid = audit_sig_pid;
1020 if (audit_sig_sid) {
1021 memcpy(sig_data->ctx, ctx, len);
1022 security_release_secctx(ctx, len);
1024 audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
1025 sig_data, sizeof(*sig_data) + len);
1028 case AUDIT_TTY_GET: {
1029 struct audit_tty_status s;
1030 struct task_struct *tsk = current;
1032 spin_lock(&tsk->sighand->siglock);
1033 s.enabled = tsk->signal->audit_tty;
1034 s.log_passwd = tsk->signal->audit_tty_log_passwd;
1035 spin_unlock(&tsk->sighand->siglock);
1037 audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
1040 case AUDIT_TTY_SET: {
1041 struct audit_tty_status s, old;
1042 struct task_struct *tsk = current;
1043 struct audit_buffer *ab;
1045 memset(&s, 0, sizeof(s));
1046 /* guard against past and future API changes */
1047 memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
1048 /* check if new data is valid */
1049 if ((s.enabled != 0 && s.enabled != 1) ||
1050 (s.log_passwd != 0 && s.log_passwd != 1))
1053 spin_lock(&tsk->sighand->siglock);
1054 old.enabled = tsk->signal->audit_tty;
1055 old.log_passwd = tsk->signal->audit_tty_log_passwd;
1057 tsk->signal->audit_tty = s.enabled;
1058 tsk->signal->audit_tty_log_passwd = s.log_passwd;
1060 spin_unlock(&tsk->sighand->siglock);
1062 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1063 audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
1064 " old-log_passwd=%d new-log_passwd=%d res=%d",
1065 old.enabled, s.enabled, old.log_passwd,
1066 s.log_passwd, !err);
1075 return err < 0 ? err : 0;
1079 * Get message from skb. Each message is processed by audit_receive_msg.
1080 * Malformed skbs with wrong length are discarded silently.
1082 static void audit_receive_skb(struct sk_buff *skb)
1084 struct nlmsghdr *nlh;
1086 * len MUST be signed for nlmsg_next to be able to dec it below 0
1087 * if the nlmsg_len was not aligned
1092 nlh = nlmsg_hdr(skb);
1095 while (nlmsg_ok(nlh, len)) {
1096 err = audit_receive_msg(skb, nlh);
1097 /* if err or if this message says it wants a response */
1098 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
1099 netlink_ack(skb, nlh, err);
1101 nlh = nlmsg_next(nlh, &len);
1105 /* Receive messages from netlink socket. */
1106 static void audit_receive(struct sk_buff *skb)
1108 mutex_lock(&audit_cmd_mutex);
1109 audit_receive_skb(skb);
1110 mutex_unlock(&audit_cmd_mutex);
1113 /* Run custom bind function on netlink socket group connect or bind requests. */
1114 static int audit_bind(int group)
1116 if (!capable(CAP_AUDIT_READ))
1122 static int __net_init audit_net_init(struct net *net)
1124 struct netlink_kernel_cfg cfg = {
1125 .input = audit_receive,
1127 .flags = NL_CFG_F_NONROOT_RECV,
1128 .groups = AUDIT_NLGRP_MAX,
1131 struct audit_net *aunet = net_generic(net, audit_net_id);
1133 aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
1134 if (aunet->nlsk == NULL) {
1135 audit_panic("cannot initialize netlink socket in namespace");
1138 aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
1142 static void __net_exit audit_net_exit(struct net *net)
1144 struct audit_net *aunet = net_generic(net, audit_net_id);
1145 struct sock *sock = aunet->nlsk;
1146 if (sock == audit_sock) {
1151 RCU_INIT_POINTER(aunet->nlsk, NULL);
1153 netlink_kernel_release(sock);
1156 static struct pernet_operations audit_net_ops __net_initdata = {
1157 .init = audit_net_init,
1158 .exit = audit_net_exit,
1159 .id = &audit_net_id,
1160 .size = sizeof(struct audit_net),
1163 /* Initialize audit support at boot time. */
1164 static int __init audit_init(void)
1168 if (audit_initialized == AUDIT_DISABLED)
1171 pr_info("initializing netlink subsys (%s)\n",
1172 audit_default ? "enabled" : "disabled");
1173 register_pernet_subsys(&audit_net_ops);
1175 skb_queue_head_init(&audit_skb_queue);
1176 skb_queue_head_init(&audit_skb_hold_queue);
1177 audit_initialized = AUDIT_INITIALIZED;
1178 audit_enabled = audit_default;
1179 audit_ever_enabled |= !!audit_default;
1181 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
1183 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1184 INIT_LIST_HEAD(&audit_inode_hash[i]);
1188 __initcall(audit_init);
1190 /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1191 static int __init audit_enable(char *str)
1193 audit_default = !!simple_strtol(str, NULL, 0);
1195 audit_initialized = AUDIT_DISABLED;
1197 pr_info("%s\n", audit_default ?
1198 "enabled (after initialization)" : "disabled (until reboot)");
1202 __setup("audit=", audit_enable);
1204 /* Process kernel command-line parameter at boot time.
1205 * audit_backlog_limit=<n> */
1206 static int __init audit_backlog_limit_set(char *str)
1208 u32 audit_backlog_limit_arg;
1210 pr_info("audit_backlog_limit: ");
1211 if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
1212 pr_cont("using default of %u, unable to parse %s\n",
1213 audit_backlog_limit, str);
1217 audit_backlog_limit = audit_backlog_limit_arg;
1218 pr_cont("%d\n", audit_backlog_limit);
1222 __setup("audit_backlog_limit=", audit_backlog_limit_set);
1224 static void audit_buffer_free(struct audit_buffer *ab)
1226 unsigned long flags;
1234 spin_lock_irqsave(&audit_freelist_lock, flags);
1235 if (audit_freelist_count > AUDIT_MAXFREE)
1238 audit_freelist_count++;
1239 list_add(&ab->list, &audit_freelist);
1241 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1244 static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
1245 gfp_t gfp_mask, int type)
1247 unsigned long flags;
1248 struct audit_buffer *ab = NULL;
1249 struct nlmsghdr *nlh;
1251 spin_lock_irqsave(&audit_freelist_lock, flags);
1252 if (!list_empty(&audit_freelist)) {
1253 ab = list_entry(audit_freelist.next,
1254 struct audit_buffer, list);
1255 list_del(&ab->list);
1256 --audit_freelist_count;
1258 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1261 ab = kmalloc(sizeof(*ab), gfp_mask);
1267 ab->gfp_mask = gfp_mask;
1269 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1273 nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0);
1283 audit_buffer_free(ab);
1288 * audit_serial - compute a serial number for the audit record
1290 * Compute a serial number for the audit record. Audit records are
1291 * written to user-space as soon as they are generated, so a complete
1292 * audit record may be written in several pieces. The timestamp of the
1293 * record and this serial number are used by the user-space tools to
1294 * determine which pieces belong to the same audit record. The
1295 * (timestamp,serial) tuple is unique for each syscall and is live from
1296 * syscall entry to syscall exit.
1298 * NOTE: Another possibility is to store the formatted records off the
1299 * audit context (for those records that have a context), and emit them
1300 * all at syscall exit. However, this could delay the reporting of
1301 * significant errors until syscall exit (or never, if the system
1304 unsigned int audit_serial(void)
1306 static atomic_t serial = ATOMIC_INIT(0);
1308 return atomic_add_return(1, &serial);
1311 static inline void audit_get_stamp(struct audit_context *ctx,
1312 struct timespec *t, unsigned int *serial)
1314 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1316 *serial = audit_serial();
1321 * Wait for auditd to drain the queue a little
1323 static long wait_for_auditd(long sleep_time)
1325 DECLARE_WAITQUEUE(wait, current);
1326 set_current_state(TASK_UNINTERRUPTIBLE);
1327 add_wait_queue_exclusive(&audit_backlog_wait, &wait);
1329 if (audit_backlog_limit &&
1330 skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
1331 sleep_time = schedule_timeout(sleep_time);
1333 __set_current_state(TASK_RUNNING);
1334 remove_wait_queue(&audit_backlog_wait, &wait);
1340 * audit_log_start - obtain an audit buffer
1341 * @ctx: audit_context (may be NULL)
1342 * @gfp_mask: type of allocation
1343 * @type: audit message type
1345 * Returns audit_buffer pointer on success or NULL on error.
1347 * Obtain an audit buffer. This routine does locking to obtain the
1348 * audit buffer, but then no locking is required for calls to
1349 * audit_log_*format. If the task (ctx) is a task that is currently in a
1350 * syscall, then the syscall is marked as auditable and an audit record
1351 * will be written at syscall exit. If there is no associated task, then
1352 * task context (ctx) should be NULL.
1354 struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1357 struct audit_buffer *ab = NULL;
1359 unsigned int uninitialized_var(serial);
1360 int reserve = 5; /* Allow atomic callers to go up to five
1361 entries over the normal backlog limit */
1362 unsigned long timeout_start = jiffies;
1364 if (audit_initialized != AUDIT_INITIALIZED)
1367 if (unlikely(audit_filter_type(type)))
1370 if (gfp_mask & __GFP_WAIT) {
1371 if (audit_pid && audit_pid == current->pid)
1372 gfp_mask &= ~__GFP_WAIT;
1377 while (audit_backlog_limit
1378 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
1379 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) {
1382 sleep_time = timeout_start + audit_backlog_wait_time - jiffies;
1383 if (sleep_time > 0) {
1384 sleep_time = wait_for_auditd(sleep_time);
1389 if (audit_rate_check() && printk_ratelimit())
1390 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1391 skb_queue_len(&audit_skb_queue),
1392 audit_backlog_limit);
1393 audit_log_lost("backlog limit exceeded");
1394 audit_backlog_wait_time = audit_backlog_wait_overflow;
1395 wake_up(&audit_backlog_wait);
1400 audit_backlog_wait_time = audit_backlog_wait_time_master;
1402 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1404 audit_log_lost("out of memory in audit_log_start");
1408 audit_get_stamp(ab->ctx, &t, &serial);
1410 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1411 t.tv_sec, t.tv_nsec/1000000, serial);
1416 * audit_expand - expand skb in the audit buffer
1418 * @extra: space to add at tail of the skb
1420 * Returns 0 (no space) on failed expansion, or available space if
1423 static inline int audit_expand(struct audit_buffer *ab, int extra)
1425 struct sk_buff *skb = ab->skb;
1426 int oldtail = skb_tailroom(skb);
1427 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1428 int newtail = skb_tailroom(skb);
1431 audit_log_lost("out of memory in audit_expand");
1435 skb->truesize += newtail - oldtail;
1440 * Format an audit message into the audit buffer. If there isn't enough
1441 * room in the audit buffer, more room will be allocated and vsnprint
1442 * will be called a second time. Currently, we assume that a printk
1443 * can't format message larger than 1024 bytes, so we don't either.
1445 static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1449 struct sk_buff *skb;
1457 avail = skb_tailroom(skb);
1459 avail = audit_expand(ab, AUDIT_BUFSIZ);
1463 va_copy(args2, args);
1464 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1466 /* The printk buffer is 1024 bytes long, so if we get
1467 * here and AUDIT_BUFSIZ is at least 1024, then we can
1468 * log everything that printk could have logged. */
1469 avail = audit_expand(ab,
1470 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1473 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1484 * audit_log_format - format a message into the audit buffer.
1486 * @fmt: format string
1487 * @...: optional parameters matching @fmt string
1489 * All the work is done in audit_log_vformat.
1491 void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1497 va_start(args, fmt);
1498 audit_log_vformat(ab, fmt, args);
1503 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1504 * @ab: the audit_buffer
1505 * @buf: buffer to convert to hex
1506 * @len: length of @buf to be converted
1508 * No return value; failure to expand is silently ignored.
1510 * This function will take the passed buf and convert it into a string of
1511 * ascii hex digits. The new string is placed onto the skb.
1513 void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1516 int i, avail, new_len;
1518 struct sk_buff *skb;
1525 avail = skb_tailroom(skb);
1527 if (new_len >= avail) {
1528 /* Round the buffer request up to the next multiple */
1529 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1530 avail = audit_expand(ab, new_len);
1535 ptr = skb_tail_pointer(skb);
1536 for (i = 0; i < len; i++)
1537 ptr = hex_byte_pack_upper(ptr, buf[i]);
1539 skb_put(skb, len << 1); /* new string is twice the old string */
1543 * Format a string of no more than slen characters into the audit buffer,
1544 * enclosed in quote marks.
1546 void audit_log_n_string(struct audit_buffer *ab, const char *string,
1551 struct sk_buff *skb;
1558 avail = skb_tailroom(skb);
1559 new_len = slen + 3; /* enclosing quotes + null terminator */
1560 if (new_len > avail) {
1561 avail = audit_expand(ab, new_len);
1565 ptr = skb_tail_pointer(skb);
1567 memcpy(ptr, string, slen);
1571 skb_put(skb, slen + 2); /* don't include null terminator */
1575 * audit_string_contains_control - does a string need to be logged in hex
1576 * @string: string to be checked
1577 * @len: max length of the string to check
1579 int audit_string_contains_control(const char *string, size_t len)
1581 const unsigned char *p;
1582 for (p = string; p < (const unsigned char *)string + len; p++) {
1583 if (*p == '"' || *p < 0x21 || *p > 0x7e)
1590 * audit_log_n_untrustedstring - log a string that may contain random characters
1592 * @len: length of string (not including trailing null)
1593 * @string: string to be logged
1595 * This code will escape a string that is passed to it if the string
1596 * contains a control character, unprintable character, double quote mark,
1597 * or a space. Unescaped strings will start and end with a double quote mark.
1598 * Strings that are escaped are printed in hex (2 digits per char).
1600 * The caller specifies the number of characters in the string to log, which may
1601 * or may not be the entire string.
1603 void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1606 if (audit_string_contains_control(string, len))
1607 audit_log_n_hex(ab, string, len);
1609 audit_log_n_string(ab, string, len);
1613 * audit_log_untrustedstring - log a string that may contain random characters
1615 * @string: string to be logged
1617 * Same as audit_log_n_untrustedstring(), except that strlen is used to
1618 * determine string length.
1620 void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
1622 audit_log_n_untrustedstring(ab, string, strlen(string));
1625 /* This is a helper-function to print the escaped d_path */
1626 void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
1627 const struct path *path)
1632 audit_log_format(ab, "%s", prefix);
1634 /* We will allow 11 spaces for ' (deleted)' to be appended */
1635 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1637 audit_log_string(ab, "<no_memory>");
1640 p = d_path(path, pathname, PATH_MAX+11);
1641 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1642 /* FIXME: can we save some information here? */
1643 audit_log_string(ab, "<too_long>");
1645 audit_log_untrustedstring(ab, p);
1649 void audit_log_session_info(struct audit_buffer *ab)
1651 unsigned int sessionid = audit_get_sessionid(current);
1652 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1654 audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
1657 void audit_log_key(struct audit_buffer *ab, char *key)
1659 audit_log_format(ab, " key=");
1661 audit_log_untrustedstring(ab, key);
1663 audit_log_format(ab, "(null)");
1666 void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
1670 audit_log_format(ab, " %s=", prefix);
1671 CAP_FOR_EACH_U32(i) {
1672 audit_log_format(ab, "%08x",
1673 cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]);
1677 static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
1679 kernel_cap_t *perm = &name->fcap.permitted;
1680 kernel_cap_t *inh = &name->fcap.inheritable;
1683 if (!cap_isclear(*perm)) {
1684 audit_log_cap(ab, "cap_fp", perm);
1687 if (!cap_isclear(*inh)) {
1688 audit_log_cap(ab, "cap_fi", inh);
1693 audit_log_format(ab, " cap_fe=%d cap_fver=%x",
1694 name->fcap.fE, name->fcap_ver);
1697 static inline int audit_copy_fcaps(struct audit_names *name,
1698 const struct dentry *dentry)
1700 struct cpu_vfs_cap_data caps;
1706 rc = get_vfs_caps_from_disk(dentry, &caps);
1710 name->fcap.permitted = caps.permitted;
1711 name->fcap.inheritable = caps.inheritable;
1712 name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
1713 name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >>
1714 VFS_CAP_REVISION_SHIFT;
1719 /* Copy inode data into an audit_names. */
1720 void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
1721 const struct inode *inode)
1723 name->ino = inode->i_ino;
1724 name->dev = inode->i_sb->s_dev;
1725 name->mode = inode->i_mode;
1726 name->uid = inode->i_uid;
1727 name->gid = inode->i_gid;
1728 name->rdev = inode->i_rdev;
1729 security_inode_getsecid(inode, &name->osid);
1730 audit_copy_fcaps(name, dentry);
1734 * audit_log_name - produce AUDIT_PATH record from struct audit_names
1735 * @context: audit_context for the task
1736 * @n: audit_names structure with reportable details
1737 * @path: optional path to report instead of audit_names->name
1738 * @record_num: record number to report when handling a list of names
1739 * @call_panic: optional pointer to int that will be updated if secid fails
1741 void audit_log_name(struct audit_context *context, struct audit_names *n,
1742 struct path *path, int record_num, int *call_panic)
1744 struct audit_buffer *ab;
1745 ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
1749 audit_log_format(ab, "item=%d", record_num);
1752 audit_log_d_path(ab, " name=", path);
1754 switch (n->name_len) {
1755 case AUDIT_NAME_FULL:
1756 /* log the full path */
1757 audit_log_format(ab, " name=");
1758 audit_log_untrustedstring(ab, n->name->name);
1761 /* name was specified as a relative path and the
1762 * directory component is the cwd */
1763 audit_log_d_path(ab, " name=", &context->pwd);
1766 /* log the name's directory component */
1767 audit_log_format(ab, " name=");
1768 audit_log_n_untrustedstring(ab, n->name->name,
1772 audit_log_format(ab, " name=(null)");
1774 if (n->ino != (unsigned long)-1)
1775 audit_log_format(ab, " inode=%lu"
1776 " dev=%02x:%02x mode=%#ho"
1777 " ouid=%u ogid=%u rdev=%02x:%02x",
1782 from_kuid(&init_user_ns, n->uid),
1783 from_kgid(&init_user_ns, n->gid),
1789 if (security_secid_to_secctx(
1790 n->osid, &ctx, &len)) {
1791 audit_log_format(ab, " osid=%u", n->osid);
1795 audit_log_format(ab, " obj=%s", ctx);
1796 security_release_secctx(ctx, len);
1800 /* log the audit_names record type */
1801 audit_log_format(ab, " nametype=");
1803 case AUDIT_TYPE_NORMAL:
1804 audit_log_format(ab, "NORMAL");
1806 case AUDIT_TYPE_PARENT:
1807 audit_log_format(ab, "PARENT");
1809 case AUDIT_TYPE_CHILD_DELETE:
1810 audit_log_format(ab, "DELETE");
1812 case AUDIT_TYPE_CHILD_CREATE:
1813 audit_log_format(ab, "CREATE");
1816 audit_log_format(ab, "UNKNOWN");
1820 audit_log_fcaps(ab, n);
1824 int audit_log_task_context(struct audit_buffer *ab)
1831 security_task_getsecid(current, &sid);
1835 error = security_secid_to_secctx(sid, &ctx, &len);
1837 if (error != -EINVAL)
1842 audit_log_format(ab, " subj=%s", ctx);
1843 security_release_secctx(ctx, len);
1847 audit_panic("error in audit_log_task_context");
1850 EXPORT_SYMBOL(audit_log_task_context);
1852 void audit_log_d_path_exe(struct audit_buffer *ab,
1853 struct mm_struct *mm)
1855 struct file *exe_file;
1860 exe_file = get_mm_exe_file(mm);
1864 audit_log_d_path(ab, " exe=", &exe_file->f_path);
1868 audit_log_format(ab, " exe=(null)");
1871 void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
1873 const struct cred *cred;
1874 char comm[sizeof(tsk->comm)];
1880 /* tsk == current */
1881 cred = current_cred();
1883 spin_lock_irq(&tsk->sighand->siglock);
1884 if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
1885 tty = tsk->signal->tty->name;
1888 spin_unlock_irq(&tsk->sighand->siglock);
1890 audit_log_format(ab,
1891 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
1892 " euid=%u suid=%u fsuid=%u"
1893 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
1896 from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
1897 from_kuid(&init_user_ns, cred->uid),
1898 from_kgid(&init_user_ns, cred->gid),
1899 from_kuid(&init_user_ns, cred->euid),
1900 from_kuid(&init_user_ns, cred->suid),
1901 from_kuid(&init_user_ns, cred->fsuid),
1902 from_kgid(&init_user_ns, cred->egid),
1903 from_kgid(&init_user_ns, cred->sgid),
1904 from_kgid(&init_user_ns, cred->fsgid),
1905 tty, audit_get_sessionid(tsk));
1907 audit_log_format(ab, " comm=");
1908 audit_log_untrustedstring(ab, get_task_comm(comm, tsk));
1910 audit_log_d_path_exe(ab, tsk->mm);
1911 audit_log_task_context(ab);
1913 EXPORT_SYMBOL(audit_log_task_info);
1916 * audit_log_link_denied - report a link restriction denial
1917 * @operation: specific link opreation
1918 * @link: the path that triggered the restriction
1920 void audit_log_link_denied(const char *operation, struct path *link)
1922 struct audit_buffer *ab;
1923 struct audit_names *name;
1925 name = kzalloc(sizeof(*name), GFP_NOFS);
1929 /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
1930 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1934 audit_log_format(ab, "op=%s", operation);
1935 audit_log_task_info(ab, current);
1936 audit_log_format(ab, " res=0");
1939 /* Generate AUDIT_PATH record with object. */
1940 name->type = AUDIT_TYPE_NORMAL;
1941 audit_copy_inode(name, link->dentry, link->dentry->d_inode);
1942 audit_log_name(current->audit_context, name, link, 0, NULL);
1948 * audit_log_end - end one audit record
1949 * @ab: the audit_buffer
1951 * netlink_unicast() cannot be called inside an irq context because it blocks
1952 * (last arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed
1953 * on a queue and a tasklet is scheduled to remove them from the queue outside
1954 * the irq context. May be called in any context.
1956 void audit_log_end(struct audit_buffer *ab)
1960 if (!audit_rate_check()) {
1961 audit_log_lost("rate limit exceeded");
1963 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
1965 nlh->nlmsg_len = ab->skb->len;
1966 kauditd_send_multicast_skb(ab->skb, ab->gfp_mask);
1969 * The original kaudit unicast socket sends up messages with
1970 * nlmsg_len set to the payload length rather than the entire
1971 * message length. This breaks the standard set by netlink.
1972 * The existing auditd daemon assumes this breakage. Fixing
1973 * this would require co-ordinating a change in the established
1974 * protocol between the kaudit kernel subsystem and the auditd
1977 nlh->nlmsg_len -= NLMSG_HDRLEN;
1980 skb_queue_tail(&audit_skb_queue, ab->skb);
1981 wake_up_interruptible(&kauditd_wait);
1983 audit_printk_skb(ab->skb);
1987 audit_buffer_free(ab);
1991 * audit_log - Log an audit record
1992 * @ctx: audit context
1993 * @gfp_mask: type of allocation
1994 * @type: audit message type
1995 * @fmt: format string to use
1996 * @...: variable parameters matching the format string
1998 * This is a convenience function that calls audit_log_start,
1999 * audit_log_vformat, and audit_log_end. It may be called
2002 void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
2003 const char *fmt, ...)
2005 struct audit_buffer *ab;
2008 ab = audit_log_start(ctx, gfp_mask, type);
2010 va_start(args, fmt);
2011 audit_log_vformat(ab, fmt, args);
2017 #ifdef CONFIG_SECURITY
2019 * audit_log_secctx - Converts and logs SELinux context
2021 * @secid: security number
2023 * This is a helper function that calls security_secid_to_secctx to convert
2024 * secid to secctx and then adds the (converted) SELinux context to the audit
2025 * log by calling audit_log_format, thus also preventing leak of internal secid
2026 * to userspace. If secid cannot be converted audit_panic is called.
2028 void audit_log_secctx(struct audit_buffer *ab, u32 secid)
2033 if (security_secid_to_secctx(secid, &secctx, &len)) {
2034 audit_panic("Cannot convert secid to context");
2036 audit_log_format(ab, " obj=%s", secctx);
2037 security_release_secctx(secctx, len);
2040 EXPORT_SYMBOL(audit_log_secctx);
2043 EXPORT_SYMBOL(audit_log_start);
2044 EXPORT_SYMBOL(audit_log_end);
2045 EXPORT_SYMBOL(audit_log_format);
2046 EXPORT_SYMBOL(audit_log);