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/init.h>
47 #include <linux/types.h>
48 #include <linux/atomic.h>
50 #include <linux/export.h>
51 #include <linux/slab.h>
52 #include <linux/err.h>
53 #include <linux/kthread.h>
54 #include <linux/kernel.h>
55 #include <linux/syscalls.h>
57 #include <linux/audit.h>
60 #include <net/netlink.h>
61 #include <linux/skbuff.h>
62 #ifdef CONFIG_SECURITY
63 #include <linux/security.h>
65 #include <linux/freezer.h>
66 #include <linux/tty.h>
67 #include <linux/pid_namespace.h>
68 #include <net/netns/generic.h>
72 /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
73 * (Initialization happens after skb_init is called.) */
74 #define AUDIT_DISABLED -1
75 #define AUDIT_UNINITIALIZED 0
76 #define AUDIT_INITIALIZED 1
77 static int audit_initialized;
81 #define AUDIT_LOCKED 2
83 u32 audit_ever_enabled;
85 EXPORT_SYMBOL_GPL(audit_enabled);
87 /* Default state when kernel boots without any parameters. */
88 static u32 audit_default;
90 /* If auditing cannot proceed, audit_failure selects what happens. */
91 static u32 audit_failure = AUDIT_FAIL_PRINTK;
94 * If audit records are to be written to the netlink socket, audit_pid
95 * contains the pid of the auditd process and audit_nlk_portid contains
96 * the portid to use to send netlink messages to that process.
99 static __u32 audit_nlk_portid;
101 /* If audit_rate_limit is non-zero, limit the rate of sending audit records
102 * to that number per second. This prevents DoS attacks, but results in
103 * audit records being dropped. */
104 static u32 audit_rate_limit;
106 /* Number of outstanding audit_buffers allowed.
107 * When set to zero, this means unlimited. */
108 static u32 audit_backlog_limit = 64;
109 #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
110 static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
111 static u32 audit_backlog_wait_overflow = 0;
113 /* The identity of the user shutting down the audit system. */
114 kuid_t audit_sig_uid = INVALID_UID;
115 pid_t audit_sig_pid = -1;
116 u32 audit_sig_sid = 0;
118 /* Records can be lost in several ways:
119 0) [suppressed in audit_alloc]
120 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
121 2) out of memory in audit_log_move [alloc_skb]
122 3) suppressed due to audit_rate_limit
123 4) suppressed due to audit_backlog_limit
125 static atomic_t audit_lost = ATOMIC_INIT(0);
127 /* The netlink socket. */
128 static struct sock *audit_sock;
129 static int audit_net_id;
131 /* Hash for inode-based rules */
132 struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
134 /* The audit_freelist is a list of pre-allocated audit buffers (if more
135 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
136 * being placed on the freelist). */
137 static DEFINE_SPINLOCK(audit_freelist_lock);
138 static int audit_freelist_count;
139 static LIST_HEAD(audit_freelist);
141 static struct sk_buff_head audit_skb_queue;
142 /* queue of skbs to send to auditd when/if it comes back */
143 static struct sk_buff_head audit_skb_hold_queue;
144 static struct task_struct *kauditd_task;
145 static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
146 static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
148 static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
153 static char *audit_feature_names[2] = {
154 "only_unset_loginuid",
155 "loginuid_immutable",
159 /* Serialize requests from userspace. */
160 DEFINE_MUTEX(audit_cmd_mutex);
162 /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
163 * audit records. Since printk uses a 1024 byte buffer, this buffer
164 * should be at least that large. */
165 #define AUDIT_BUFSIZ 1024
167 /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
168 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
169 #define AUDIT_MAXFREE (2*NR_CPUS)
171 /* The audit_buffer is used when formatting an audit record. The caller
172 * locks briefly to get the record off the freelist or to allocate the
173 * buffer, and locks briefly to send the buffer to the netlink layer or
174 * to place it on a transmit queue. Multiple audit_buffers can be in
175 * use simultaneously. */
176 struct audit_buffer {
177 struct list_head list;
178 struct sk_buff *skb; /* formatted skb ready to send */
179 struct audit_context *ctx; /* NULL or associated context */
189 static void audit_set_portid(struct audit_buffer *ab, __u32 portid)
192 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
193 nlh->nlmsg_pid = portid;
197 void audit_panic(const char *message)
199 switch (audit_failure) {
200 case AUDIT_FAIL_SILENT:
202 case AUDIT_FAIL_PRINTK:
203 if (printk_ratelimit())
204 pr_err("%s\n", message);
206 case AUDIT_FAIL_PANIC:
207 /* test audit_pid since printk is always losey, why bother? */
209 panic("audit: %s\n", message);
214 static inline int audit_rate_check(void)
216 static unsigned long last_check = 0;
217 static int messages = 0;
218 static DEFINE_SPINLOCK(lock);
221 unsigned long elapsed;
224 if (!audit_rate_limit) return 1;
226 spin_lock_irqsave(&lock, flags);
227 if (++messages < audit_rate_limit) {
231 elapsed = now - last_check;
238 spin_unlock_irqrestore(&lock, flags);
244 * audit_log_lost - conditionally log lost audit message event
245 * @message: the message stating reason for lost audit message
247 * Emit at least 1 message per second, even if audit_rate_check is
249 * Always increment the lost messages counter.
251 void audit_log_lost(const char *message)
253 static unsigned long last_msg = 0;
254 static DEFINE_SPINLOCK(lock);
259 atomic_inc(&audit_lost);
261 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
264 spin_lock_irqsave(&lock, flags);
266 if (now - last_msg > HZ) {
270 spin_unlock_irqrestore(&lock, flags);
274 if (printk_ratelimit())
275 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
276 atomic_read(&audit_lost),
278 audit_backlog_limit);
279 audit_panic(message);
283 static int audit_log_config_change(char *function_name, u32 new, u32 old,
286 struct audit_buffer *ab;
289 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
292 audit_log_format(ab, "%s=%u old=%u", function_name, new, old);
293 audit_log_session_info(ab);
294 rc = audit_log_task_context(ab);
296 allow_changes = 0; /* Something weird, deny request */
297 audit_log_format(ab, " res=%d", allow_changes);
302 static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
304 int allow_changes, rc = 0;
305 u32 old = *to_change;
307 /* check if we are locked */
308 if (audit_enabled == AUDIT_LOCKED)
313 if (audit_enabled != AUDIT_OFF) {
314 rc = audit_log_config_change(function_name, new, old, allow_changes);
319 /* If we are allowed, make the change */
320 if (allow_changes == 1)
322 /* Not allowed, update reason */
328 static int audit_set_rate_limit(u32 limit)
330 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
333 static int audit_set_backlog_limit(u32 limit)
335 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
338 static int audit_set_backlog_wait_time(u32 timeout)
340 return audit_do_config_change("audit_backlog_wait_time",
341 &audit_backlog_wait_time, timeout);
344 static int audit_set_enabled(u32 state)
347 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
350 rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
352 audit_ever_enabled |= !!state;
357 static int audit_set_failure(u32 state)
359 if (state != AUDIT_FAIL_SILENT
360 && state != AUDIT_FAIL_PRINTK
361 && state != AUDIT_FAIL_PANIC)
364 return audit_do_config_change("audit_failure", &audit_failure, state);
368 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
369 * already have been sent via prink/syslog and so if these messages are dropped
370 * it is not a huge concern since we already passed the audit_log_lost()
371 * notification and stuff. This is just nice to get audit messages during
372 * boot before auditd is running or messages generated while auditd is stopped.
373 * This only holds messages is audit_default is set, aka booting with audit=1
374 * or building your kernel that way.
376 static void audit_hold_skb(struct sk_buff *skb)
379 (!audit_backlog_limit ||
380 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit))
381 skb_queue_tail(&audit_skb_hold_queue, skb);
387 * For one reason or another this nlh isn't getting delivered to the userspace
388 * audit daemon, just send it to printk.
390 static void audit_printk_skb(struct sk_buff *skb)
392 struct nlmsghdr *nlh = nlmsg_hdr(skb);
393 char *data = nlmsg_data(nlh);
395 if (nlh->nlmsg_type != AUDIT_EOE) {
396 if (printk_ratelimit())
397 pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
399 audit_log_lost("printk limit exceeded");
405 static void kauditd_send_skb(struct sk_buff *skb)
408 /* take a reference in case we can't send it and we want to hold it */
410 err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
412 BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
414 pr_err("*NO* daemon at audit_pid=%d\n", audit_pid);
415 audit_log_lost("auditd disappeared");
419 /* we might get lucky and get this in the next auditd */
422 /* drop the extra reference if sent ok */
427 * kauditd_send_multicast_skb - send the skb to multicast userspace listeners
429 * This function doesn't consume an skb as might be expected since it has to
432 static void kauditd_send_multicast_skb(struct sk_buff *skb)
434 struct sk_buff *copy;
435 struct audit_net *aunet = net_generic(&init_net, audit_net_id);
436 struct sock *sock = aunet->nlsk;
438 if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
442 * The seemingly wasteful skb_copy() rather than bumping the refcount
443 * using skb_get() is necessary because non-standard mods are made to
444 * the skb by the original kaudit unicast socket send routine. The
445 * existing auditd daemon assumes this breakage. Fixing this would
446 * require co-ordinating a change in the established protocol between
447 * the kaudit kernel subsystem and the auditd userspace code. There is
448 * no reason for new multicast clients to continue with this
451 copy = skb_copy(skb, GFP_KERNEL);
455 nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL);
459 * flush_hold_queue - empty the hold queue if auditd appears
461 * If auditd just started, drain the queue of messages already
462 * sent to syslog/printk. Remember loss here is ok. We already
463 * called audit_log_lost() if it didn't go out normally. so the
464 * race between the skb_dequeue and the next check for audit_pid
467 * If you ever find kauditd to be too slow we can get a perf win
468 * by doing our own locking and keeping better track if there
469 * are messages in this queue. I don't see the need now, but
470 * in 5 years when I want to play with this again I'll see this
471 * note and still have no friggin idea what i'm thinking today.
473 static void flush_hold_queue(void)
477 if (!audit_default || !audit_pid)
480 skb = skb_dequeue(&audit_skb_hold_queue);
484 while (skb && audit_pid) {
485 kauditd_send_skb(skb);
486 skb = skb_dequeue(&audit_skb_hold_queue);
490 * if auditd just disappeared but we
491 * dequeued an skb we need to drop ref
497 static int kauditd_thread(void *dummy)
500 while (!kthread_should_stop()) {
505 skb = skb_dequeue(&audit_skb_queue);
508 if (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit)
509 wake_up(&audit_backlog_wait);
511 kauditd_send_skb(skb);
513 audit_printk_skb(skb);
517 wait_event_freezable(kauditd_wait, skb_queue_len(&audit_skb_queue));
522 int audit_send_list(void *_dest)
524 struct audit_netlink_list *dest = _dest;
526 struct net *net = dest->net;
527 struct audit_net *aunet = net_generic(net, audit_net_id);
529 /* wait for parent to finish and send an ACK */
530 mutex_lock(&audit_cmd_mutex);
531 mutex_unlock(&audit_cmd_mutex);
533 while ((skb = __skb_dequeue(&dest->q)) != NULL)
534 netlink_unicast(aunet->nlsk, skb, dest->portid, 0);
542 struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done,
543 int multi, const void *payload, int size)
546 struct nlmsghdr *nlh;
548 int flags = multi ? NLM_F_MULTI : 0;
549 int t = done ? NLMSG_DONE : type;
551 skb = nlmsg_new(size, GFP_KERNEL);
555 nlh = nlmsg_put(skb, portid, seq, t, size, flags);
558 data = nlmsg_data(nlh);
559 memcpy(data, payload, size);
567 static int audit_send_reply_thread(void *arg)
569 struct audit_reply *reply = (struct audit_reply *)arg;
570 struct net *net = reply->net;
571 struct audit_net *aunet = net_generic(net, audit_net_id);
573 mutex_lock(&audit_cmd_mutex);
574 mutex_unlock(&audit_cmd_mutex);
576 /* Ignore failure. It'll only happen if the sender goes away,
577 because our timeout is set to infinite. */
578 netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0);
584 * audit_send_reply - send an audit reply message via netlink
585 * @request_skb: skb of request we are replying to (used to target the reply)
586 * @seq: sequence number
587 * @type: audit message type
588 * @done: done (last) flag
589 * @multi: multi-part message flag
590 * @payload: payload data
591 * @size: payload size
593 * Allocates an skb, builds the netlink message, and sends it to the port id.
594 * No failure notifications.
596 static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
597 int multi, const void *payload, int size)
599 u32 portid = NETLINK_CB(request_skb).portid;
600 struct net *net = sock_net(NETLINK_CB(request_skb).sk);
602 struct task_struct *tsk;
603 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
609 skb = audit_make_reply(portid, seq, type, done, multi, payload, size);
613 reply->net = get_net(net);
614 reply->portid = portid;
617 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
626 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
629 static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
633 /* Only support initial user namespace for now. */
635 * We return ECONNREFUSED because it tricks userspace into thinking
636 * that audit was not configured into the kernel. Lots of users
637 * configure their PAM stack (because that's what the distro does)
638 * to reject login if unable to send messages to audit. If we return
639 * ECONNREFUSED the PAM stack thinks the kernel does not have audit
640 * configured in and will let login proceed. If we return EPERM
641 * userspace will reject all logins. This should be removed when we
642 * support non init namespaces!!
644 if (current_user_ns() != &init_user_ns)
645 return -ECONNREFUSED;
654 case AUDIT_GET_FEATURE:
655 case AUDIT_SET_FEATURE:
656 case AUDIT_LIST_RULES:
659 case AUDIT_SIGNAL_INFO:
663 case AUDIT_MAKE_EQUIV:
664 /* Only support auditd and auditctl in initial pid namespace
666 if ((task_active_pid_ns(current) != &init_pid_ns))
669 if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
673 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
674 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
675 if (!netlink_capable(skb, CAP_AUDIT_WRITE))
678 default: /* bad msg */
685 static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
688 uid_t uid = from_kuid(&init_user_ns, current_uid());
689 pid_t pid = task_tgid_nr(current);
691 if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
696 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
699 audit_log_format(*ab, "pid=%d uid=%u", pid, uid);
700 audit_log_session_info(*ab);
701 audit_log_task_context(*ab);
706 int is_audit_feature_set(int i)
708 return af.features & AUDIT_FEATURE_TO_MASK(i);
712 static int audit_get_feature(struct sk_buff *skb)
716 seq = nlmsg_hdr(skb)->nlmsg_seq;
718 audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
723 static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
724 u32 old_lock, u32 new_lock, int res)
726 struct audit_buffer *ab;
728 if (audit_enabled == AUDIT_OFF)
731 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE);
732 audit_log_task_info(ab, current);
733 audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
734 audit_feature_names[which], !!old_feature, !!new_feature,
735 !!old_lock, !!new_lock, res);
739 static int audit_set_feature(struct sk_buff *skb)
741 struct audit_features *uaf;
744 BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
745 uaf = nlmsg_data(nlmsg_hdr(skb));
747 /* if there is ever a version 2 we should handle that here */
749 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
750 u32 feature = AUDIT_FEATURE_TO_MASK(i);
751 u32 old_feature, new_feature, old_lock, new_lock;
753 /* if we are not changing this feature, move along */
754 if (!(feature & uaf->mask))
757 old_feature = af.features & feature;
758 new_feature = uaf->features & feature;
759 new_lock = (uaf->lock | af.lock) & feature;
760 old_lock = af.lock & feature;
762 /* are we changing a locked feature? */
763 if (old_lock && (new_feature != old_feature)) {
764 audit_log_feature_change(i, old_feature, new_feature,
765 old_lock, new_lock, 0);
769 /* nothing invalid, do the changes */
770 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
771 u32 feature = AUDIT_FEATURE_TO_MASK(i);
772 u32 old_feature, new_feature, old_lock, new_lock;
774 /* if we are not changing this feature, move along */
775 if (!(feature & uaf->mask))
778 old_feature = af.features & feature;
779 new_feature = uaf->features & feature;
780 old_lock = af.lock & feature;
781 new_lock = (uaf->lock | af.lock) & feature;
783 if (new_feature != old_feature)
784 audit_log_feature_change(i, old_feature, new_feature,
785 old_lock, new_lock, 1);
788 af.features |= feature;
790 af.features &= ~feature;
797 static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
802 struct audit_buffer *ab;
803 u16 msg_type = nlh->nlmsg_type;
804 struct audit_sig_info *sig_data;
808 err = audit_netlink_ok(skb, msg_type);
812 /* As soon as there's any sign of userspace auditd,
813 * start kauditd to talk to it */
815 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
816 if (IS_ERR(kauditd_task)) {
817 err = PTR_ERR(kauditd_task);
822 seq = nlh->nlmsg_seq;
823 data = nlmsg_data(nlh);
827 struct audit_status s;
828 memset(&s, 0, sizeof(s));
829 s.enabled = audit_enabled;
830 s.failure = audit_failure;
832 s.rate_limit = audit_rate_limit;
833 s.backlog_limit = audit_backlog_limit;
834 s.lost = atomic_read(&audit_lost);
835 s.backlog = skb_queue_len(&audit_skb_queue);
836 s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
837 s.backlog_wait_time = audit_backlog_wait_time;
838 audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
842 struct audit_status s;
843 memset(&s, 0, sizeof(s));
844 /* guard against past and future API changes */
845 memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
846 if (s.mask & AUDIT_STATUS_ENABLED) {
847 err = audit_set_enabled(s.enabled);
851 if (s.mask & AUDIT_STATUS_FAILURE) {
852 err = audit_set_failure(s.failure);
856 if (s.mask & AUDIT_STATUS_PID) {
859 if ((!new_pid) && (task_tgid_vnr(current) != audit_pid))
861 if (audit_enabled != AUDIT_OFF)
862 audit_log_config_change("audit_pid", new_pid, audit_pid, 1);
864 audit_nlk_portid = NETLINK_CB(skb).portid;
865 audit_sock = skb->sk;
867 if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
868 err = audit_set_rate_limit(s.rate_limit);
872 if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
873 err = audit_set_backlog_limit(s.backlog_limit);
877 if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
878 if (sizeof(s) > (size_t)nlh->nlmsg_len)
880 if (s.backlog_wait_time < 0 ||
881 s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
883 err = audit_set_backlog_wait_time(s.backlog_wait_time);
889 case AUDIT_GET_FEATURE:
890 err = audit_get_feature(skb);
894 case AUDIT_SET_FEATURE:
895 err = audit_set_feature(skb);
900 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
901 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
902 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
905 err = audit_filter_user(msg_type);
906 if (err == 1) { /* match or error */
908 if (msg_type == AUDIT_USER_TTY) {
909 err = tty_audit_push_current();
913 mutex_unlock(&audit_cmd_mutex);
914 audit_log_common_recv_msg(&ab, msg_type);
915 if (msg_type != AUDIT_USER_TTY)
916 audit_log_format(ab, " msg='%.*s'",
917 AUDIT_MESSAGE_TEXT_MAX,
922 audit_log_format(ab, " data=");
923 size = nlmsg_len(nlh);
925 ((unsigned char *)data)[size - 1] == '\0')
927 audit_log_n_untrustedstring(ab, data, size);
929 audit_set_portid(ab, NETLINK_CB(skb).portid);
931 mutex_lock(&audit_cmd_mutex);
936 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
938 if (audit_enabled == AUDIT_LOCKED) {
939 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
940 audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled);
944 err = audit_rule_change(msg_type, NETLINK_CB(skb).portid,
945 seq, data, nlmsg_len(nlh));
947 case AUDIT_LIST_RULES:
948 err = audit_list_rules_send(skb, seq);
952 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
953 audit_log_format(ab, " op=trim res=1");
956 case AUDIT_MAKE_EQUIV: {
959 size_t msglen = nlmsg_len(nlh);
963 if (msglen < 2 * sizeof(u32))
965 memcpy(sizes, bufp, 2 * sizeof(u32));
966 bufp += 2 * sizeof(u32);
967 msglen -= 2 * sizeof(u32);
968 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
973 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
979 /* OK, here comes... */
980 err = audit_tag_tree(old, new);
982 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
984 audit_log_format(ab, " op=make_equiv old=");
985 audit_log_untrustedstring(ab, old);
986 audit_log_format(ab, " new=");
987 audit_log_untrustedstring(ab, new);
988 audit_log_format(ab, " res=%d", !err);
994 case AUDIT_SIGNAL_INFO:
997 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
1001 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
1004 security_release_secctx(ctx, len);
1007 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
1008 sig_data->pid = audit_sig_pid;
1009 if (audit_sig_sid) {
1010 memcpy(sig_data->ctx, ctx, len);
1011 security_release_secctx(ctx, len);
1013 audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
1014 sig_data, sizeof(*sig_data) + len);
1017 case AUDIT_TTY_GET: {
1018 struct audit_tty_status s;
1019 struct task_struct *tsk = current;
1021 spin_lock(&tsk->sighand->siglock);
1022 s.enabled = tsk->signal->audit_tty;
1023 s.log_passwd = tsk->signal->audit_tty_log_passwd;
1024 spin_unlock(&tsk->sighand->siglock);
1026 audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
1029 case AUDIT_TTY_SET: {
1030 struct audit_tty_status s, old;
1031 struct task_struct *tsk = current;
1032 struct audit_buffer *ab;
1034 memset(&s, 0, sizeof(s));
1035 /* guard against past and future API changes */
1036 memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
1037 /* check if new data is valid */
1038 if ((s.enabled != 0 && s.enabled != 1) ||
1039 (s.log_passwd != 0 && s.log_passwd != 1))
1042 spin_lock(&tsk->sighand->siglock);
1043 old.enabled = tsk->signal->audit_tty;
1044 old.log_passwd = tsk->signal->audit_tty_log_passwd;
1046 tsk->signal->audit_tty = s.enabled;
1047 tsk->signal->audit_tty_log_passwd = s.log_passwd;
1049 spin_unlock(&tsk->sighand->siglock);
1051 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1052 audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
1053 " old-log_passwd=%d new-log_passwd=%d res=%d",
1054 old.enabled, s.enabled, old.log_passwd,
1055 s.log_passwd, !err);
1064 return err < 0 ? err : 0;
1068 * Get message from skb. Each message is processed by audit_receive_msg.
1069 * Malformed skbs with wrong length are discarded silently.
1071 static void audit_receive_skb(struct sk_buff *skb)
1073 struct nlmsghdr *nlh;
1075 * len MUST be signed for nlmsg_next to be able to dec it below 0
1076 * if the nlmsg_len was not aligned
1081 nlh = nlmsg_hdr(skb);
1084 while (nlmsg_ok(nlh, len)) {
1085 err = audit_receive_msg(skb, nlh);
1086 /* if err or if this message says it wants a response */
1087 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
1088 netlink_ack(skb, nlh, err);
1090 nlh = nlmsg_next(nlh, &len);
1094 /* Receive messages from netlink socket. */
1095 static void audit_receive(struct sk_buff *skb)
1097 mutex_lock(&audit_cmd_mutex);
1098 audit_receive_skb(skb);
1099 mutex_unlock(&audit_cmd_mutex);
1102 /* Run custom bind function on netlink socket group connect or bind requests. */
1103 static int audit_bind(int group)
1105 if (!capable(CAP_AUDIT_READ))
1111 static int __net_init audit_net_init(struct net *net)
1113 struct netlink_kernel_cfg cfg = {
1114 .input = audit_receive,
1116 .flags = NL_CFG_F_NONROOT_RECV,
1117 .groups = AUDIT_NLGRP_MAX,
1120 struct audit_net *aunet = net_generic(net, audit_net_id);
1122 aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
1123 if (aunet->nlsk == NULL) {
1124 audit_panic("cannot initialize netlink socket in namespace");
1127 aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
1131 static void __net_exit audit_net_exit(struct net *net)
1133 struct audit_net *aunet = net_generic(net, audit_net_id);
1134 struct sock *sock = aunet->nlsk;
1135 if (sock == audit_sock) {
1140 RCU_INIT_POINTER(aunet->nlsk, NULL);
1142 netlink_kernel_release(sock);
1145 static struct pernet_operations audit_net_ops __net_initdata = {
1146 .init = audit_net_init,
1147 .exit = audit_net_exit,
1148 .id = &audit_net_id,
1149 .size = sizeof(struct audit_net),
1152 /* Initialize audit support at boot time. */
1153 static int __init audit_init(void)
1157 if (audit_initialized == AUDIT_DISABLED)
1160 pr_info("initializing netlink subsys (%s)\n",
1161 audit_default ? "enabled" : "disabled");
1162 register_pernet_subsys(&audit_net_ops);
1164 skb_queue_head_init(&audit_skb_queue);
1165 skb_queue_head_init(&audit_skb_hold_queue);
1166 audit_initialized = AUDIT_INITIALIZED;
1167 audit_enabled = audit_default;
1168 audit_ever_enabled |= !!audit_default;
1170 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
1172 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1173 INIT_LIST_HEAD(&audit_inode_hash[i]);
1177 __initcall(audit_init);
1179 /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1180 static int __init audit_enable(char *str)
1182 audit_default = !!simple_strtol(str, NULL, 0);
1184 audit_initialized = AUDIT_DISABLED;
1186 pr_info("%s\n", audit_default ?
1187 "enabled (after initialization)" : "disabled (until reboot)");
1191 __setup("audit=", audit_enable);
1193 /* Process kernel command-line parameter at boot time.
1194 * audit_backlog_limit=<n> */
1195 static int __init audit_backlog_limit_set(char *str)
1197 u32 audit_backlog_limit_arg;
1199 pr_info("audit_backlog_limit: ");
1200 if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
1201 pr_cont("using default of %u, unable to parse %s\n",
1202 audit_backlog_limit, str);
1206 audit_backlog_limit = audit_backlog_limit_arg;
1207 pr_cont("%d\n", audit_backlog_limit);
1211 __setup("audit_backlog_limit=", audit_backlog_limit_set);
1213 static void audit_buffer_free(struct audit_buffer *ab)
1215 unsigned long flags;
1223 spin_lock_irqsave(&audit_freelist_lock, flags);
1224 if (audit_freelist_count > AUDIT_MAXFREE)
1227 audit_freelist_count++;
1228 list_add(&ab->list, &audit_freelist);
1230 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1233 static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
1234 gfp_t gfp_mask, int type)
1236 unsigned long flags;
1237 struct audit_buffer *ab = NULL;
1238 struct nlmsghdr *nlh;
1240 spin_lock_irqsave(&audit_freelist_lock, flags);
1241 if (!list_empty(&audit_freelist)) {
1242 ab = list_entry(audit_freelist.next,
1243 struct audit_buffer, list);
1244 list_del(&ab->list);
1245 --audit_freelist_count;
1247 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1250 ab = kmalloc(sizeof(*ab), gfp_mask);
1256 ab->gfp_mask = gfp_mask;
1258 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1262 nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0);
1272 audit_buffer_free(ab);
1277 * audit_serial - compute a serial number for the audit record
1279 * Compute a serial number for the audit record. Audit records are
1280 * written to user-space as soon as they are generated, so a complete
1281 * audit record may be written in several pieces. The timestamp of the
1282 * record and this serial number are used by the user-space tools to
1283 * determine which pieces belong to the same audit record. The
1284 * (timestamp,serial) tuple is unique for each syscall and is live from
1285 * syscall entry to syscall exit.
1287 * NOTE: Another possibility is to store the formatted records off the
1288 * audit context (for those records that have a context), and emit them
1289 * all at syscall exit. However, this could delay the reporting of
1290 * significant errors until syscall exit (or never, if the system
1293 unsigned int audit_serial(void)
1295 static atomic_t serial = ATOMIC_INIT(0);
1297 return atomic_add_return(1, &serial);
1300 static inline void audit_get_stamp(struct audit_context *ctx,
1301 struct timespec *t, unsigned int *serial)
1303 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1305 *serial = audit_serial();
1310 * Wait for auditd to drain the queue a little
1312 static long wait_for_auditd(long sleep_time)
1314 DECLARE_WAITQUEUE(wait, current);
1315 set_current_state(TASK_UNINTERRUPTIBLE);
1316 add_wait_queue_exclusive(&audit_backlog_wait, &wait);
1318 if (audit_backlog_limit &&
1319 skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
1320 sleep_time = schedule_timeout(sleep_time);
1322 __set_current_state(TASK_RUNNING);
1323 remove_wait_queue(&audit_backlog_wait, &wait);
1329 * audit_log_start - obtain an audit buffer
1330 * @ctx: audit_context (may be NULL)
1331 * @gfp_mask: type of allocation
1332 * @type: audit message type
1334 * Returns audit_buffer pointer on success or NULL on error.
1336 * Obtain an audit buffer. This routine does locking to obtain the
1337 * audit buffer, but then no locking is required for calls to
1338 * audit_log_*format. If the task (ctx) is a task that is currently in a
1339 * syscall, then the syscall is marked as auditable and an audit record
1340 * will be written at syscall exit. If there is no associated task, then
1341 * task context (ctx) should be NULL.
1343 struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1346 struct audit_buffer *ab = NULL;
1348 unsigned int uninitialized_var(serial);
1349 int reserve = 5; /* Allow atomic callers to go up to five
1350 entries over the normal backlog limit */
1351 unsigned long timeout_start = jiffies;
1353 if (audit_initialized != AUDIT_INITIALIZED)
1356 if (unlikely(audit_filter_type(type)))
1359 if (gfp_mask & __GFP_WAIT) {
1360 if (audit_pid && audit_pid == current->pid)
1361 gfp_mask &= ~__GFP_WAIT;
1366 while (audit_backlog_limit
1367 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
1368 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) {
1371 sleep_time = timeout_start + audit_backlog_wait_time - jiffies;
1372 if (sleep_time > 0) {
1373 sleep_time = wait_for_auditd(sleep_time);
1378 if (audit_rate_check() && printk_ratelimit())
1379 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1380 skb_queue_len(&audit_skb_queue),
1381 audit_backlog_limit);
1382 audit_log_lost("backlog limit exceeded");
1383 audit_backlog_wait_time = audit_backlog_wait_overflow;
1384 wake_up(&audit_backlog_wait);
1388 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
1390 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1392 audit_log_lost("out of memory in audit_log_start");
1396 audit_get_stamp(ab->ctx, &t, &serial);
1398 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1399 t.tv_sec, t.tv_nsec/1000000, serial);
1404 * audit_expand - expand skb in the audit buffer
1406 * @extra: space to add at tail of the skb
1408 * Returns 0 (no space) on failed expansion, or available space if
1411 static inline int audit_expand(struct audit_buffer *ab, int extra)
1413 struct sk_buff *skb = ab->skb;
1414 int oldtail = skb_tailroom(skb);
1415 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1416 int newtail = skb_tailroom(skb);
1419 audit_log_lost("out of memory in audit_expand");
1423 skb->truesize += newtail - oldtail;
1428 * Format an audit message into the audit buffer. If there isn't enough
1429 * room in the audit buffer, more room will be allocated and vsnprint
1430 * will be called a second time. Currently, we assume that a printk
1431 * can't format message larger than 1024 bytes, so we don't either.
1433 static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1437 struct sk_buff *skb;
1445 avail = skb_tailroom(skb);
1447 avail = audit_expand(ab, AUDIT_BUFSIZ);
1451 va_copy(args2, args);
1452 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1454 /* The printk buffer is 1024 bytes long, so if we get
1455 * here and AUDIT_BUFSIZ is at least 1024, then we can
1456 * log everything that printk could have logged. */
1457 avail = audit_expand(ab,
1458 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1461 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1472 * audit_log_format - format a message into the audit buffer.
1474 * @fmt: format string
1475 * @...: optional parameters matching @fmt string
1477 * All the work is done in audit_log_vformat.
1479 void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1485 va_start(args, fmt);
1486 audit_log_vformat(ab, fmt, args);
1491 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1492 * @ab: the audit_buffer
1493 * @buf: buffer to convert to hex
1494 * @len: length of @buf to be converted
1496 * No return value; failure to expand is silently ignored.
1498 * This function will take the passed buf and convert it into a string of
1499 * ascii hex digits. The new string is placed onto the skb.
1501 void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1504 int i, avail, new_len;
1506 struct sk_buff *skb;
1513 avail = skb_tailroom(skb);
1515 if (new_len >= avail) {
1516 /* Round the buffer request up to the next multiple */
1517 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1518 avail = audit_expand(ab, new_len);
1523 ptr = skb_tail_pointer(skb);
1524 for (i = 0; i < len; i++)
1525 ptr = hex_byte_pack_upper(ptr, buf[i]);
1527 skb_put(skb, len << 1); /* new string is twice the old string */
1531 * Format a string of no more than slen characters into the audit buffer,
1532 * enclosed in quote marks.
1534 void audit_log_n_string(struct audit_buffer *ab, const char *string,
1539 struct sk_buff *skb;
1546 avail = skb_tailroom(skb);
1547 new_len = slen + 3; /* enclosing quotes + null terminator */
1548 if (new_len > avail) {
1549 avail = audit_expand(ab, new_len);
1553 ptr = skb_tail_pointer(skb);
1555 memcpy(ptr, string, slen);
1559 skb_put(skb, slen + 2); /* don't include null terminator */
1563 * audit_string_contains_control - does a string need to be logged in hex
1564 * @string: string to be checked
1565 * @len: max length of the string to check
1567 int audit_string_contains_control(const char *string, size_t len)
1569 const unsigned char *p;
1570 for (p = string; p < (const unsigned char *)string + len; p++) {
1571 if (*p == '"' || *p < 0x21 || *p > 0x7e)
1578 * audit_log_n_untrustedstring - log a string that may contain random characters
1580 * @len: length of string (not including trailing null)
1581 * @string: string to be logged
1583 * This code will escape a string that is passed to it if the string
1584 * contains a control character, unprintable character, double quote mark,
1585 * or a space. Unescaped strings will start and end with a double quote mark.
1586 * Strings that are escaped are printed in hex (2 digits per char).
1588 * The caller specifies the number of characters in the string to log, which may
1589 * or may not be the entire string.
1591 void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1594 if (audit_string_contains_control(string, len))
1595 audit_log_n_hex(ab, string, len);
1597 audit_log_n_string(ab, string, len);
1601 * audit_log_untrustedstring - log a string that may contain random characters
1603 * @string: string to be logged
1605 * Same as audit_log_n_untrustedstring(), except that strlen is used to
1606 * determine string length.
1608 void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
1610 audit_log_n_untrustedstring(ab, string, strlen(string));
1613 /* This is a helper-function to print the escaped d_path */
1614 void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
1615 const struct path *path)
1620 audit_log_format(ab, "%s", prefix);
1622 /* We will allow 11 spaces for ' (deleted)' to be appended */
1623 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1625 audit_log_string(ab, "<no_memory>");
1628 p = d_path(path, pathname, PATH_MAX+11);
1629 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1630 /* FIXME: can we save some information here? */
1631 audit_log_string(ab, "<too_long>");
1633 audit_log_untrustedstring(ab, p);
1637 void audit_log_session_info(struct audit_buffer *ab)
1639 unsigned int sessionid = audit_get_sessionid(current);
1640 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1642 audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
1645 void audit_log_key(struct audit_buffer *ab, char *key)
1647 audit_log_format(ab, " key=");
1649 audit_log_untrustedstring(ab, key);
1651 audit_log_format(ab, "(null)");
1654 void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
1658 audit_log_format(ab, " %s=", prefix);
1659 CAP_FOR_EACH_U32(i) {
1660 audit_log_format(ab, "%08x",
1661 cap->cap[CAP_LAST_U32 - i]);
1665 static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
1667 kernel_cap_t *perm = &name->fcap.permitted;
1668 kernel_cap_t *inh = &name->fcap.inheritable;
1671 if (!cap_isclear(*perm)) {
1672 audit_log_cap(ab, "cap_fp", perm);
1675 if (!cap_isclear(*inh)) {
1676 audit_log_cap(ab, "cap_fi", inh);
1681 audit_log_format(ab, " cap_fe=%d cap_fver=%x",
1682 name->fcap.fE, name->fcap_ver);
1685 static inline int audit_copy_fcaps(struct audit_names *name,
1686 const struct dentry *dentry)
1688 struct cpu_vfs_cap_data caps;
1694 rc = get_vfs_caps_from_disk(dentry, &caps);
1698 name->fcap.permitted = caps.permitted;
1699 name->fcap.inheritable = caps.inheritable;
1700 name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
1701 name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >>
1702 VFS_CAP_REVISION_SHIFT;
1707 /* Copy inode data into an audit_names. */
1708 void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
1709 const struct inode *inode)
1711 name->ino = inode->i_ino;
1712 name->dev = inode->i_sb->s_dev;
1713 name->mode = inode->i_mode;
1714 name->uid = inode->i_uid;
1715 name->gid = inode->i_gid;
1716 name->rdev = inode->i_rdev;
1717 security_inode_getsecid(inode, &name->osid);
1718 audit_copy_fcaps(name, dentry);
1722 * audit_log_name - produce AUDIT_PATH record from struct audit_names
1723 * @context: audit_context for the task
1724 * @n: audit_names structure with reportable details
1725 * @path: optional path to report instead of audit_names->name
1726 * @record_num: record number to report when handling a list of names
1727 * @call_panic: optional pointer to int that will be updated if secid fails
1729 void audit_log_name(struct audit_context *context, struct audit_names *n,
1730 struct path *path, int record_num, int *call_panic)
1732 struct audit_buffer *ab;
1733 ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
1737 audit_log_format(ab, "item=%d", record_num);
1740 audit_log_d_path(ab, " name=", path);
1742 switch (n->name_len) {
1743 case AUDIT_NAME_FULL:
1744 /* log the full path */
1745 audit_log_format(ab, " name=");
1746 audit_log_untrustedstring(ab, n->name->name);
1749 /* name was specified as a relative path and the
1750 * directory component is the cwd */
1751 audit_log_d_path(ab, " name=", &context->pwd);
1754 /* log the name's directory component */
1755 audit_log_format(ab, " name=");
1756 audit_log_n_untrustedstring(ab, n->name->name,
1760 audit_log_format(ab, " name=(null)");
1762 if (n->ino != (unsigned long)-1) {
1763 audit_log_format(ab, " inode=%lu"
1764 " dev=%02x:%02x mode=%#ho"
1765 " ouid=%u ogid=%u rdev=%02x:%02x",
1770 from_kuid(&init_user_ns, n->uid),
1771 from_kgid(&init_user_ns, n->gid),
1778 if (security_secid_to_secctx(
1779 n->osid, &ctx, &len)) {
1780 audit_log_format(ab, " osid=%u", n->osid);
1784 audit_log_format(ab, " obj=%s", ctx);
1785 security_release_secctx(ctx, len);
1789 /* log the audit_names record type */
1790 audit_log_format(ab, " nametype=");
1792 case AUDIT_TYPE_NORMAL:
1793 audit_log_format(ab, "NORMAL");
1795 case AUDIT_TYPE_PARENT:
1796 audit_log_format(ab, "PARENT");
1798 case AUDIT_TYPE_CHILD_DELETE:
1799 audit_log_format(ab, "DELETE");
1801 case AUDIT_TYPE_CHILD_CREATE:
1802 audit_log_format(ab, "CREATE");
1805 audit_log_format(ab, "UNKNOWN");
1809 audit_log_fcaps(ab, n);
1813 int audit_log_task_context(struct audit_buffer *ab)
1820 security_task_getsecid(current, &sid);
1824 error = security_secid_to_secctx(sid, &ctx, &len);
1826 if (error != -EINVAL)
1831 audit_log_format(ab, " subj=%s", ctx);
1832 security_release_secctx(ctx, len);
1836 audit_panic("error in audit_log_task_context");
1839 EXPORT_SYMBOL(audit_log_task_context);
1841 void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
1843 const struct cred *cred;
1844 char comm[sizeof(tsk->comm)];
1845 struct mm_struct *mm = tsk->mm;
1851 /* tsk == current */
1852 cred = current_cred();
1854 spin_lock_irq(&tsk->sighand->siglock);
1855 if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
1856 tty = tsk->signal->tty->name;
1859 spin_unlock_irq(&tsk->sighand->siglock);
1861 audit_log_format(ab,
1862 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
1863 " euid=%u suid=%u fsuid=%u"
1864 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
1867 from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
1868 from_kuid(&init_user_ns, cred->uid),
1869 from_kgid(&init_user_ns, cred->gid),
1870 from_kuid(&init_user_ns, cred->euid),
1871 from_kuid(&init_user_ns, cred->suid),
1872 from_kuid(&init_user_ns, cred->fsuid),
1873 from_kgid(&init_user_ns, cred->egid),
1874 from_kgid(&init_user_ns, cred->sgid),
1875 from_kgid(&init_user_ns, cred->fsgid),
1876 tty, audit_get_sessionid(tsk));
1878 audit_log_format(ab, " comm=");
1879 audit_log_untrustedstring(ab, get_task_comm(comm, tsk));
1882 down_read(&mm->mmap_sem);
1884 audit_log_d_path(ab, " exe=", &mm->exe_file->f_path);
1885 up_read(&mm->mmap_sem);
1887 audit_log_format(ab, " exe=(null)");
1888 audit_log_task_context(ab);
1890 EXPORT_SYMBOL(audit_log_task_info);
1893 * audit_log_link_denied - report a link restriction denial
1894 * @operation: specific link opreation
1895 * @link: the path that triggered the restriction
1897 void audit_log_link_denied(const char *operation, struct path *link)
1899 struct audit_buffer *ab;
1900 struct audit_names *name;
1902 name = kzalloc(sizeof(*name), GFP_NOFS);
1906 /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
1907 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1911 audit_log_format(ab, "op=%s", operation);
1912 audit_log_task_info(ab, current);
1913 audit_log_format(ab, " res=0");
1916 /* Generate AUDIT_PATH record with object. */
1917 name->type = AUDIT_TYPE_NORMAL;
1918 audit_copy_inode(name, link->dentry, link->dentry->d_inode);
1919 audit_log_name(current->audit_context, name, link, 0, NULL);
1925 * audit_log_end - end one audit record
1926 * @ab: the audit_buffer
1928 * netlink_unicast() cannot be called inside an irq context because it blocks
1929 * (last arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed
1930 * on a queue and a tasklet is scheduled to remove them from the queue outside
1931 * the irq context. May be called in any context.
1933 void audit_log_end(struct audit_buffer *ab)
1937 if (!audit_rate_check()) {
1938 audit_log_lost("rate limit exceeded");
1940 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
1942 nlh->nlmsg_len = ab->skb->len;
1943 kauditd_send_multicast_skb(ab->skb);
1946 * The original kaudit unicast socket sends up messages with
1947 * nlmsg_len set to the payload length rather than the entire
1948 * message length. This breaks the standard set by netlink.
1949 * The existing auditd daemon assumes this breakage. Fixing
1950 * this would require co-ordinating a change in the established
1951 * protocol between the kaudit kernel subsystem and the auditd
1954 nlh->nlmsg_len -= NLMSG_HDRLEN;
1957 skb_queue_tail(&audit_skb_queue, ab->skb);
1958 wake_up_interruptible(&kauditd_wait);
1960 audit_printk_skb(ab->skb);
1964 audit_buffer_free(ab);
1968 * audit_log - Log an audit record
1969 * @ctx: audit context
1970 * @gfp_mask: type of allocation
1971 * @type: audit message type
1972 * @fmt: format string to use
1973 * @...: variable parameters matching the format string
1975 * This is a convenience function that calls audit_log_start,
1976 * audit_log_vformat, and audit_log_end. It may be called
1979 void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
1980 const char *fmt, ...)
1982 struct audit_buffer *ab;
1985 ab = audit_log_start(ctx, gfp_mask, type);
1987 va_start(args, fmt);
1988 audit_log_vformat(ab, fmt, args);
1994 #ifdef CONFIG_SECURITY
1996 * audit_log_secctx - Converts and logs SELinux context
1998 * @secid: security number
2000 * This is a helper function that calls security_secid_to_secctx to convert
2001 * secid to secctx and then adds the (converted) SELinux context to the audit
2002 * log by calling audit_log_format, thus also preventing leak of internal secid
2003 * to userspace. If secid cannot be converted audit_panic is called.
2005 void audit_log_secctx(struct audit_buffer *ab, u32 secid)
2010 if (security_secid_to_secctx(secid, &secctx, &len)) {
2011 audit_panic("Cannot convert secid to context");
2013 audit_log_format(ab, " obj=%s", secctx);
2014 security_release_secctx(secctx, len);
2017 EXPORT_SYMBOL(audit_log_secctx);
2020 EXPORT_SYMBOL(audit_log_start);
2021 EXPORT_SYMBOL(audit_log_end);
2022 EXPORT_SYMBOL(audit_log_format);
2023 EXPORT_SYMBOL(audit_log);