1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34#include <linux/file.h>
35#include <linux/init.h>
36#include <linux/types.h>
37#include <linux/atomic.h>
38#include <linux/mm.h>
39#include <linux/export.h>
40#include <linux/slab.h>
41#include <linux/err.h>
42#include <linux/kthread.h>
43#include <linux/kernel.h>
44#include <linux/syscalls.h>
45#include <linux/spinlock.h>
46#include <linux/rcupdate.h>
47#include <linux/mutex.h>
48#include <linux/gfp.h>
49#include <linux/pid.h>
50
51#include <linux/audit.h>
52
53#include <net/sock.h>
54#include <net/netlink.h>
55#include <linux/skbuff.h>
56#ifdef CONFIG_SECURITY
57#include <linux/security.h>
58#endif
59#include <linux/freezer.h>
60#include <linux/pid_namespace.h>
61#include <net/netns/generic.h>
62
63#include "audit.h"
64
65
66
67#define AUDIT_DISABLED -1
68#define AUDIT_UNINITIALIZED 0
69#define AUDIT_INITIALIZED 1
70static int audit_initialized = AUDIT_UNINITIALIZED;
71
72u32 audit_enabled = AUDIT_OFF;
73bool audit_ever_enabled = !!AUDIT_OFF;
74
75EXPORT_SYMBOL_GPL(audit_enabled);
76
77
78static u32 audit_default = AUDIT_OFF;
79
80
81static u32 audit_failure = AUDIT_FAIL_PRINTK;
82
83
84static unsigned int audit_net_id;
85
86
87
88
89
90struct audit_net {
91 struct sock *sk;
92};
93
94
95
96
97
98
99
100
101
102
103
104
105struct auditd_connection {
106 struct pid *pid;
107 u32 portid;
108 struct net *net;
109 struct rcu_head rcu;
110};
111static struct auditd_connection __rcu *auditd_conn;
112static DEFINE_SPINLOCK(auditd_conn_lock);
113
114
115
116
117static u32 audit_rate_limit;
118
119
120
121static u32 audit_backlog_limit = 64;
122#define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
123static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
124
125
126static kuid_t audit_sig_uid = INVALID_UID;
127static pid_t audit_sig_pid = -1;
128static u32 audit_sig_sid;
129
130
131
132
133
134
135
136
137static atomic_t audit_lost = ATOMIC_INIT(0);
138
139
140
141
142static atomic_t audit_backlog_wait_time_actual = ATOMIC_INIT(0);
143
144
145struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
146
147static struct kmem_cache *audit_buffer_cache;
148
149
150static struct sk_buff_head audit_queue;
151
152static struct sk_buff_head audit_retry_queue;
153
154static struct sk_buff_head audit_hold_queue;
155
156
157static struct task_struct *kauditd_task;
158static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
159
160
161static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
162
163static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
164 .mask = -1,
165 .features = 0,
166 .lock = 0,};
167
168static char *audit_feature_names[2] = {
169 "only_unset_loginuid",
170 "loginuid_immutable",
171};
172
173
174
175
176
177
178
179
180
181
182
183
184static struct audit_ctl_mutex {
185 struct mutex lock;
186 void *owner;
187} audit_cmd_mutex;
188
189
190
191
192#define AUDIT_BUFSIZ 1024
193
194
195
196
197
198
199struct audit_buffer {
200 struct sk_buff *skb;
201 struct audit_context *ctx;
202 gfp_t gfp_mask;
203};
204
205struct audit_reply {
206 __u32 portid;
207 struct net *net;
208 struct sk_buff *skb;
209};
210
211
212
213
214
215
216
217
218int auditd_test_task(struct task_struct *task)
219{
220 int rc;
221 struct auditd_connection *ac;
222
223 rcu_read_lock();
224 ac = rcu_dereference(auditd_conn);
225 rc = (ac && ac->pid == task_tgid(task) ? 1 : 0);
226 rcu_read_unlock();
227
228 return rc;
229}
230
231
232
233
234void audit_ctl_lock(void)
235{
236 mutex_lock(&audit_cmd_mutex.lock);
237 audit_cmd_mutex.owner = current;
238}
239
240
241
242
243void audit_ctl_unlock(void)
244{
245 audit_cmd_mutex.owner = NULL;
246 mutex_unlock(&audit_cmd_mutex.lock);
247}
248
249
250
251
252
253
254
255
256static bool audit_ctl_owner_current(void)
257{
258 return (current == audit_cmd_mutex.owner);
259}
260
261
262
263
264
265
266
267static pid_t auditd_pid_vnr(void)
268{
269 pid_t pid;
270 const struct auditd_connection *ac;
271
272 rcu_read_lock();
273 ac = rcu_dereference(auditd_conn);
274 if (!ac || !ac->pid)
275 pid = 0;
276 else
277 pid = pid_vnr(ac->pid);
278 rcu_read_unlock();
279
280 return pid;
281}
282
283
284
285
286
287
288
289
290
291static struct sock *audit_get_sk(const struct net *net)
292{
293 struct audit_net *aunet;
294
295 if (!net)
296 return NULL;
297
298 aunet = net_generic(net, audit_net_id);
299 return aunet->sk;
300}
301
302void audit_panic(const char *message)
303{
304 switch (audit_failure) {
305 case AUDIT_FAIL_SILENT:
306 break;
307 case AUDIT_FAIL_PRINTK:
308 if (printk_ratelimit())
309 pr_err("%s\n", message);
310 break;
311 case AUDIT_FAIL_PANIC:
312 panic("audit: %s\n", message);
313 break;
314 }
315}
316
317static inline int audit_rate_check(void)
318{
319 static unsigned long last_check = 0;
320 static int messages = 0;
321 static DEFINE_SPINLOCK(lock);
322 unsigned long flags;
323 unsigned long now;
324 unsigned long elapsed;
325 int retval = 0;
326
327 if (!audit_rate_limit) return 1;
328
329 spin_lock_irqsave(&lock, flags);
330 if (++messages < audit_rate_limit) {
331 retval = 1;
332 } else {
333 now = jiffies;
334 elapsed = now - last_check;
335 if (elapsed > HZ) {
336 last_check = now;
337 messages = 0;
338 retval = 1;
339 }
340 }
341 spin_unlock_irqrestore(&lock, flags);
342
343 return retval;
344}
345
346
347
348
349
350
351
352
353
354void audit_log_lost(const char *message)
355{
356 static unsigned long last_msg = 0;
357 static DEFINE_SPINLOCK(lock);
358 unsigned long flags;
359 unsigned long now;
360 int print;
361
362 atomic_inc(&audit_lost);
363
364 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
365
366 if (!print) {
367 spin_lock_irqsave(&lock, flags);
368 now = jiffies;
369 if (now - last_msg > HZ) {
370 print = 1;
371 last_msg = now;
372 }
373 spin_unlock_irqrestore(&lock, flags);
374 }
375
376 if (print) {
377 if (printk_ratelimit())
378 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
379 atomic_read(&audit_lost),
380 audit_rate_limit,
381 audit_backlog_limit);
382 audit_panic(message);
383 }
384}
385
386static int audit_log_config_change(char *function_name, u32 new, u32 old,
387 int allow_changes)
388{
389 struct audit_buffer *ab;
390 int rc = 0;
391
392 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
393 if (unlikely(!ab))
394 return rc;
395 audit_log_format(ab, "op=set %s=%u old=%u ", function_name, new, old);
396 audit_log_session_info(ab);
397 rc = audit_log_task_context(ab);
398 if (rc)
399 allow_changes = 0;
400 audit_log_format(ab, " res=%d", allow_changes);
401 audit_log_end(ab);
402 return rc;
403}
404
405static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
406{
407 int allow_changes, rc = 0;
408 u32 old = *to_change;
409
410
411 if (audit_enabled == AUDIT_LOCKED)
412 allow_changes = 0;
413 else
414 allow_changes = 1;
415
416 if (audit_enabled != AUDIT_OFF) {
417 rc = audit_log_config_change(function_name, new, old, allow_changes);
418 if (rc)
419 allow_changes = 0;
420 }
421
422
423 if (allow_changes == 1)
424 *to_change = new;
425
426 else if (rc == 0)
427 rc = -EPERM;
428 return rc;
429}
430
431static int audit_set_rate_limit(u32 limit)
432{
433 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
434}
435
436static int audit_set_backlog_limit(u32 limit)
437{
438 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
439}
440
441static int audit_set_backlog_wait_time(u32 timeout)
442{
443 return audit_do_config_change("audit_backlog_wait_time",
444 &audit_backlog_wait_time, timeout);
445}
446
447static int audit_set_enabled(u32 state)
448{
449 int rc;
450 if (state > AUDIT_LOCKED)
451 return -EINVAL;
452
453 rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
454 if (!rc)
455 audit_ever_enabled |= !!state;
456
457 return rc;
458}
459
460static int audit_set_failure(u32 state)
461{
462 if (state != AUDIT_FAIL_SILENT
463 && state != AUDIT_FAIL_PRINTK
464 && state != AUDIT_FAIL_PANIC)
465 return -EINVAL;
466
467 return audit_do_config_change("audit_failure", &audit_failure, state);
468}
469
470
471
472
473
474
475
476
477
478static void auditd_conn_free(struct rcu_head *rcu)
479{
480 struct auditd_connection *ac;
481
482 ac = container_of(rcu, struct auditd_connection, rcu);
483 put_pid(ac->pid);
484 put_net(ac->net);
485 kfree(ac);
486}
487
488
489
490
491
492
493
494
495
496
497
498static int auditd_set(struct pid *pid, u32 portid, struct net *net)
499{
500 unsigned long flags;
501 struct auditd_connection *ac_old, *ac_new;
502
503 if (!pid || !net)
504 return -EINVAL;
505
506 ac_new = kzalloc(sizeof(*ac_new), GFP_KERNEL);
507 if (!ac_new)
508 return -ENOMEM;
509 ac_new->pid = get_pid(pid);
510 ac_new->portid = portid;
511 ac_new->net = get_net(net);
512
513 spin_lock_irqsave(&auditd_conn_lock, flags);
514 ac_old = rcu_dereference_protected(auditd_conn,
515 lockdep_is_held(&auditd_conn_lock));
516 rcu_assign_pointer(auditd_conn, ac_new);
517 spin_unlock_irqrestore(&auditd_conn_lock, flags);
518
519 if (ac_old)
520 call_rcu(&ac_old->rcu, auditd_conn_free);
521
522 return 0;
523}
524
525
526
527
528
529
530
531
532static void kauditd_printk_skb(struct sk_buff *skb)
533{
534 struct nlmsghdr *nlh = nlmsg_hdr(skb);
535 char *data = nlmsg_data(nlh);
536
537 if (nlh->nlmsg_type != AUDIT_EOE && printk_ratelimit())
538 pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
539}
540
541
542
543
544
545
546
547
548
549
550static void kauditd_rehold_skb(struct sk_buff *skb, __always_unused int error)
551{
552
553 skb_queue_tail(&audit_hold_queue, skb);
554}
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569static void kauditd_hold_skb(struct sk_buff *skb, int error)
570{
571
572
573 kauditd_printk_skb(skb);
574
575
576 if (!audit_default)
577 goto drop;
578
579
580
581
582
583 if (error == -EAGAIN) {
584 if (!audit_backlog_limit ||
585 skb_queue_len(&audit_retry_queue) < audit_backlog_limit) {
586 skb_queue_tail(&audit_retry_queue, skb);
587 return;
588 }
589 audit_log_lost("kauditd retry queue overflow");
590 goto drop;
591 }
592
593
594 if (!audit_backlog_limit ||
595 skb_queue_len(&audit_hold_queue) < audit_backlog_limit) {
596 skb_queue_tail(&audit_hold_queue, skb);
597 return;
598 }
599
600
601 audit_log_lost("kauditd hold queue overflow");
602drop:
603 kfree_skb(skb);
604}
605
606
607
608
609
610
611
612
613
614
615
616static void kauditd_retry_skb(struct sk_buff *skb, __always_unused int error)
617{
618 if (!audit_backlog_limit ||
619 skb_queue_len(&audit_retry_queue) < audit_backlog_limit) {
620 skb_queue_tail(&audit_retry_queue, skb);
621 return;
622 }
623
624
625 kauditd_printk_skb(skb);
626 audit_log_lost("kauditd retry queue overflow");
627 kfree_skb(skb);
628}
629
630
631
632
633
634
635
636
637
638
639
640
641static void auditd_reset(const struct auditd_connection *ac)
642{
643 unsigned long flags;
644 struct sk_buff *skb;
645 struct auditd_connection *ac_old;
646
647
648 spin_lock_irqsave(&auditd_conn_lock, flags);
649 ac_old = rcu_dereference_protected(auditd_conn,
650 lockdep_is_held(&auditd_conn_lock));
651 if (ac && ac != ac_old) {
652
653 spin_unlock_irqrestore(&auditd_conn_lock, flags);
654 return;
655 }
656 rcu_assign_pointer(auditd_conn, NULL);
657 spin_unlock_irqrestore(&auditd_conn_lock, flags);
658
659 if (ac_old)
660 call_rcu(&ac_old->rcu, auditd_conn_free);
661
662
663
664 while ((skb = skb_dequeue(&audit_retry_queue)))
665 kauditd_hold_skb(skb, -ECONNREFUSED);
666}
667
668
669
670
671
672
673
674
675
676
677
678
679static int auditd_send_unicast_skb(struct sk_buff *skb)
680{
681 int rc;
682 u32 portid;
683 struct net *net;
684 struct sock *sk;
685 struct auditd_connection *ac;
686
687
688
689
690
691
692
693
694 rcu_read_lock();
695 ac = rcu_dereference(auditd_conn);
696 if (!ac) {
697 rcu_read_unlock();
698 kfree_skb(skb);
699 rc = -ECONNREFUSED;
700 goto err;
701 }
702 net = get_net(ac->net);
703 sk = audit_get_sk(net);
704 portid = ac->portid;
705 rcu_read_unlock();
706
707 rc = netlink_unicast(sk, skb, portid, 0);
708 put_net(net);
709 if (rc < 0)
710 goto err;
711
712 return rc;
713
714err:
715 if (ac && rc == -ECONNREFUSED)
716 auditd_reset(ac);
717 return rc;
718}
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735static int kauditd_send_queue(struct sock *sk, u32 portid,
736 struct sk_buff_head *queue,
737 unsigned int retry_limit,
738 void (*skb_hook)(struct sk_buff *skb),
739 void (*err_hook)(struct sk_buff *skb, int error))
740{
741 int rc = 0;
742 struct sk_buff *skb = NULL;
743 struct sk_buff *skb_tail;
744 unsigned int failed = 0;
745
746
747
748
749 skb_tail = skb_peek_tail(queue);
750 while ((skb != skb_tail) && (skb = skb_dequeue(queue))) {
751
752 if (skb_hook)
753 (*skb_hook)(skb);
754
755
756 if (!sk) {
757 if (err_hook)
758 (*err_hook)(skb, -ECONNREFUSED);
759 continue;
760 }
761
762retry:
763
764 skb_get(skb);
765 rc = netlink_unicast(sk, skb, portid, 0);
766 if (rc < 0) {
767
768 if (++failed >= retry_limit ||
769 rc == -ECONNREFUSED || rc == -EPERM) {
770 sk = NULL;
771 if (err_hook)
772 (*err_hook)(skb, rc);
773 if (rc == -EAGAIN)
774 rc = 0;
775
776 continue;
777 } else
778 goto retry;
779 } else {
780
781 consume_skb(skb);
782 failed = 0;
783 }
784 }
785
786 return (rc >= 0 ? 0 : rc);
787}
788
789
790
791
792
793
794
795
796
797
798static void kauditd_send_multicast_skb(struct sk_buff *skb)
799{
800 struct sk_buff *copy;
801 struct sock *sock = audit_get_sk(&init_net);
802 struct nlmsghdr *nlh;
803
804
805
806
807 if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
808 return;
809
810
811
812
813
814
815
816
817
818
819
820 copy = skb_copy(skb, GFP_KERNEL);
821 if (!copy)
822 return;
823 nlh = nlmsg_hdr(copy);
824 nlh->nlmsg_len = skb->len;
825
826 nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL);
827}
828
829
830
831
832
833static int kauditd_thread(void *dummy)
834{
835 int rc;
836 u32 portid = 0;
837 struct net *net = NULL;
838 struct sock *sk = NULL;
839 struct auditd_connection *ac;
840
841#define UNICAST_RETRIES 5
842
843 set_freezable();
844 while (!kthread_should_stop()) {
845
846 rcu_read_lock();
847 ac = rcu_dereference(auditd_conn);
848 if (!ac) {
849 rcu_read_unlock();
850 goto main_queue;
851 }
852 net = get_net(ac->net);
853 sk = audit_get_sk(net);
854 portid = ac->portid;
855 rcu_read_unlock();
856
857
858 rc = kauditd_send_queue(sk, portid,
859 &audit_hold_queue, UNICAST_RETRIES,
860 NULL, kauditd_rehold_skb);
861 if (rc < 0) {
862 sk = NULL;
863 auditd_reset(ac);
864 goto main_queue;
865 }
866
867
868 rc = kauditd_send_queue(sk, portid,
869 &audit_retry_queue, UNICAST_RETRIES,
870 NULL, kauditd_hold_skb);
871 if (rc < 0) {
872 sk = NULL;
873 auditd_reset(ac);
874 goto main_queue;
875 }
876
877main_queue:
878
879
880
881
882 rc = kauditd_send_queue(sk, portid, &audit_queue, 1,
883 kauditd_send_multicast_skb,
884 (sk ?
885 kauditd_retry_skb : kauditd_hold_skb));
886 if (ac && rc < 0)
887 auditd_reset(ac);
888 sk = NULL;
889
890
891 if (net) {
892 put_net(net);
893 net = NULL;
894 }
895
896
897 wake_up(&audit_backlog_wait);
898
899
900
901
902
903 wait_event_freezable(kauditd_wait,
904 (skb_queue_len(&audit_queue) ? 1 : 0));
905 }
906
907 return 0;
908}
909
910int audit_send_list_thread(void *_dest)
911{
912 struct audit_netlink_list *dest = _dest;
913 struct sk_buff *skb;
914 struct sock *sk = audit_get_sk(dest->net);
915
916
917 audit_ctl_lock();
918 audit_ctl_unlock();
919
920 while ((skb = __skb_dequeue(&dest->q)) != NULL)
921 netlink_unicast(sk, skb, dest->portid, 0);
922
923 put_net(dest->net);
924 kfree(dest);
925
926 return 0;
927}
928
929struct sk_buff *audit_make_reply(int seq, int type, int done,
930 int multi, const void *payload, int size)
931{
932 struct sk_buff *skb;
933 struct nlmsghdr *nlh;
934 void *data;
935 int flags = multi ? NLM_F_MULTI : 0;
936 int t = done ? NLMSG_DONE : type;
937
938 skb = nlmsg_new(size, GFP_KERNEL);
939 if (!skb)
940 return NULL;
941
942 nlh = nlmsg_put(skb, 0, seq, t, size, flags);
943 if (!nlh)
944 goto out_kfree_skb;
945 data = nlmsg_data(nlh);
946 memcpy(data, payload, size);
947 return skb;
948
949out_kfree_skb:
950 kfree_skb(skb);
951 return NULL;
952}
953
954static void audit_free_reply(struct audit_reply *reply)
955{
956 if (!reply)
957 return;
958
959 kfree_skb(reply->skb);
960 if (reply->net)
961 put_net(reply->net);
962 kfree(reply);
963}
964
965static int audit_send_reply_thread(void *arg)
966{
967 struct audit_reply *reply = (struct audit_reply *)arg;
968
969 audit_ctl_lock();
970 audit_ctl_unlock();
971
972
973
974 netlink_unicast(audit_get_sk(reply->net), reply->skb, reply->portid, 0);
975 reply->skb = NULL;
976 audit_free_reply(reply);
977 return 0;
978}
979
980
981
982
983
984
985
986
987
988
989
990
991
992static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
993 int multi, const void *payload, int size)
994{
995 struct task_struct *tsk;
996 struct audit_reply *reply;
997
998 reply = kzalloc(sizeof(*reply), GFP_KERNEL);
999 if (!reply)
1000 return;
1001
1002 reply->skb = audit_make_reply(seq, type, done, multi, payload, size);
1003 if (!reply->skb)
1004 goto err;
1005 reply->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
1006 reply->portid = NETLINK_CB(request_skb).portid;
1007
1008 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
1009 if (IS_ERR(tsk))
1010 goto err;
1011
1012 return;
1013
1014err:
1015 audit_free_reply(reply);
1016}
1017
1018
1019
1020
1021
1022static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
1023{
1024 int err = 0;
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037 if (current_user_ns() != &init_user_ns)
1038 return -ECONNREFUSED;
1039
1040 switch (msg_type) {
1041 case AUDIT_LIST:
1042 case AUDIT_ADD:
1043 case AUDIT_DEL:
1044 return -EOPNOTSUPP;
1045 case AUDIT_GET:
1046 case AUDIT_SET:
1047 case AUDIT_GET_FEATURE:
1048 case AUDIT_SET_FEATURE:
1049 case AUDIT_LIST_RULES:
1050 case AUDIT_ADD_RULE:
1051 case AUDIT_DEL_RULE:
1052 case AUDIT_SIGNAL_INFO:
1053 case AUDIT_TTY_GET:
1054 case AUDIT_TTY_SET:
1055 case AUDIT_TRIM:
1056 case AUDIT_MAKE_EQUIV:
1057
1058
1059 if (task_active_pid_ns(current) != &init_pid_ns)
1060 return -EPERM;
1061
1062 if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
1063 err = -EPERM;
1064 break;
1065 case AUDIT_USER:
1066 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
1067 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
1068 if (!netlink_capable(skb, CAP_AUDIT_WRITE))
1069 err = -EPERM;
1070 break;
1071 default:
1072 err = -EINVAL;
1073 }
1074
1075 return err;
1076}
1077
1078static void audit_log_common_recv_msg(struct audit_context *context,
1079 struct audit_buffer **ab, u16 msg_type)
1080{
1081 uid_t uid = from_kuid(&init_user_ns, current_uid());
1082 pid_t pid = task_tgid_nr(current);
1083
1084 if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
1085 *ab = NULL;
1086 return;
1087 }
1088
1089 *ab = audit_log_start(context, GFP_KERNEL, msg_type);
1090 if (unlikely(!*ab))
1091 return;
1092 audit_log_format(*ab, "pid=%d uid=%u ", pid, uid);
1093 audit_log_session_info(*ab);
1094 audit_log_task_context(*ab);
1095}
1096
1097static inline void audit_log_user_recv_msg(struct audit_buffer **ab,
1098 u16 msg_type)
1099{
1100 audit_log_common_recv_msg(NULL, ab, msg_type);
1101}
1102
1103int is_audit_feature_set(int i)
1104{
1105 return af.features & AUDIT_FEATURE_TO_MASK(i);
1106}
1107
1108
1109static int audit_get_feature(struct sk_buff *skb)
1110{
1111 u32 seq;
1112
1113 seq = nlmsg_hdr(skb)->nlmsg_seq;
1114
1115 audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
1116
1117 return 0;
1118}
1119
1120static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
1121 u32 old_lock, u32 new_lock, int res)
1122{
1123 struct audit_buffer *ab;
1124
1125 if (audit_enabled == AUDIT_OFF)
1126 return;
1127
1128 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_FEATURE_CHANGE);
1129 if (!ab)
1130 return;
1131 audit_log_task_info(ab);
1132 audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
1133 audit_feature_names[which], !!old_feature, !!new_feature,
1134 !!old_lock, !!new_lock, res);
1135 audit_log_end(ab);
1136}
1137
1138static int audit_set_feature(struct audit_features *uaf)
1139{
1140 int i;
1141
1142 BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
1143
1144
1145
1146 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1147 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1148 u32 old_feature, new_feature, old_lock, new_lock;
1149
1150
1151 if (!(feature & uaf->mask))
1152 continue;
1153
1154 old_feature = af.features & feature;
1155 new_feature = uaf->features & feature;
1156 new_lock = (uaf->lock | af.lock) & feature;
1157 old_lock = af.lock & feature;
1158
1159
1160 if (old_lock && (new_feature != old_feature)) {
1161 audit_log_feature_change(i, old_feature, new_feature,
1162 old_lock, new_lock, 0);
1163 return -EPERM;
1164 }
1165 }
1166
1167 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1168 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1169 u32 old_feature, new_feature, old_lock, new_lock;
1170
1171
1172 if (!(feature & uaf->mask))
1173 continue;
1174
1175 old_feature = af.features & feature;
1176 new_feature = uaf->features & feature;
1177 old_lock = af.lock & feature;
1178 new_lock = (uaf->lock | af.lock) & feature;
1179
1180 if (new_feature != old_feature)
1181 audit_log_feature_change(i, old_feature, new_feature,
1182 old_lock, new_lock, 1);
1183
1184 if (new_feature)
1185 af.features |= feature;
1186 else
1187 af.features &= ~feature;
1188 af.lock |= new_lock;
1189 }
1190
1191 return 0;
1192}
1193
1194static int audit_replace(struct pid *pid)
1195{
1196 pid_t pvnr;
1197 struct sk_buff *skb;
1198
1199 pvnr = pid_vnr(pid);
1200 skb = audit_make_reply(0, AUDIT_REPLACE, 0, 0, &pvnr, sizeof(pvnr));
1201 if (!skb)
1202 return -ENOMEM;
1203 return auditd_send_unicast_skb(skb);
1204}
1205
1206static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1207{
1208 u32 seq;
1209 void *data;
1210 int data_len;
1211 int err;
1212 struct audit_buffer *ab;
1213 u16 msg_type = nlh->nlmsg_type;
1214 struct audit_sig_info *sig_data;
1215 char *ctx = NULL;
1216 u32 len;
1217
1218 err = audit_netlink_ok(skb, msg_type);
1219 if (err)
1220 return err;
1221
1222 seq = nlh->nlmsg_seq;
1223 data = nlmsg_data(nlh);
1224 data_len = nlmsg_len(nlh);
1225
1226 switch (msg_type) {
1227 case AUDIT_GET: {
1228 struct audit_status s;
1229 memset(&s, 0, sizeof(s));
1230 s.enabled = audit_enabled;
1231 s.failure = audit_failure;
1232
1233
1234 s.pid = auditd_pid_vnr();
1235 s.rate_limit = audit_rate_limit;
1236 s.backlog_limit = audit_backlog_limit;
1237 s.lost = atomic_read(&audit_lost);
1238 s.backlog = skb_queue_len(&audit_queue);
1239 s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
1240 s.backlog_wait_time = audit_backlog_wait_time;
1241 s.backlog_wait_time_actual = atomic_read(&audit_backlog_wait_time_actual);
1242 audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
1243 break;
1244 }
1245 case AUDIT_SET: {
1246 struct audit_status s;
1247 memset(&s, 0, sizeof(s));
1248
1249 memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
1250 if (s.mask & AUDIT_STATUS_ENABLED) {
1251 err = audit_set_enabled(s.enabled);
1252 if (err < 0)
1253 return err;
1254 }
1255 if (s.mask & AUDIT_STATUS_FAILURE) {
1256 err = audit_set_failure(s.failure);
1257 if (err < 0)
1258 return err;
1259 }
1260 if (s.mask & AUDIT_STATUS_PID) {
1261
1262
1263
1264
1265
1266
1267 pid_t new_pid = s.pid;
1268 pid_t auditd_pid;
1269 struct pid *req_pid = task_tgid(current);
1270
1271
1272
1273 if (new_pid && (new_pid != pid_vnr(req_pid)))
1274 return -EINVAL;
1275
1276
1277 audit_replace(req_pid);
1278
1279 auditd_pid = auditd_pid_vnr();
1280 if (auditd_pid) {
1281
1282 if (new_pid) {
1283 audit_log_config_change("audit_pid",
1284 new_pid, auditd_pid, 0);
1285 return -EEXIST;
1286 }
1287
1288 if (pid_vnr(req_pid) != auditd_pid) {
1289 audit_log_config_change("audit_pid",
1290 new_pid, auditd_pid, 0);
1291 return -EACCES;
1292 }
1293 }
1294
1295 if (new_pid) {
1296
1297 err = auditd_set(req_pid,
1298 NETLINK_CB(skb).portid,
1299 sock_net(NETLINK_CB(skb).sk));
1300 if (audit_enabled != AUDIT_OFF)
1301 audit_log_config_change("audit_pid",
1302 new_pid,
1303 auditd_pid,
1304 err ? 0 : 1);
1305 if (err)
1306 return err;
1307
1308
1309 wake_up_interruptible(&kauditd_wait);
1310 } else {
1311 if (audit_enabled != AUDIT_OFF)
1312 audit_log_config_change("audit_pid",
1313 new_pid,
1314 auditd_pid, 1);
1315
1316
1317 auditd_reset(NULL);
1318 }
1319 }
1320 if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
1321 err = audit_set_rate_limit(s.rate_limit);
1322 if (err < 0)
1323 return err;
1324 }
1325 if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
1326 err = audit_set_backlog_limit(s.backlog_limit);
1327 if (err < 0)
1328 return err;
1329 }
1330 if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
1331 if (sizeof(s) > (size_t)nlh->nlmsg_len)
1332 return -EINVAL;
1333 if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
1334 return -EINVAL;
1335 err = audit_set_backlog_wait_time(s.backlog_wait_time);
1336 if (err < 0)
1337 return err;
1338 }
1339 if (s.mask == AUDIT_STATUS_LOST) {
1340 u32 lost = atomic_xchg(&audit_lost, 0);
1341
1342 audit_log_config_change("lost", 0, lost, 1);
1343 return lost;
1344 }
1345 if (s.mask == AUDIT_STATUS_BACKLOG_WAIT_TIME_ACTUAL) {
1346 u32 actual = atomic_xchg(&audit_backlog_wait_time_actual, 0);
1347
1348 audit_log_config_change("backlog_wait_time_actual", 0, actual, 1);
1349 return actual;
1350 }
1351 break;
1352 }
1353 case AUDIT_GET_FEATURE:
1354 err = audit_get_feature(skb);
1355 if (err)
1356 return err;
1357 break;
1358 case AUDIT_SET_FEATURE:
1359 if (data_len < sizeof(struct audit_features))
1360 return -EINVAL;
1361 err = audit_set_feature(data);
1362 if (err)
1363 return err;
1364 break;
1365 case AUDIT_USER:
1366 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
1367 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
1368 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
1369 return 0;
1370
1371 if (data_len < 2)
1372 return -EINVAL;
1373
1374 err = audit_filter(msg_type, AUDIT_FILTER_USER);
1375 if (err == 1) {
1376 char *str = data;
1377
1378 err = 0;
1379 if (msg_type == AUDIT_USER_TTY) {
1380 err = tty_audit_push();
1381 if (err)
1382 break;
1383 }
1384 audit_log_user_recv_msg(&ab, msg_type);
1385 if (msg_type != AUDIT_USER_TTY) {
1386
1387 str[data_len - 1] = '\0';
1388 audit_log_format(ab, " msg='%.*s'",
1389 AUDIT_MESSAGE_TEXT_MAX,
1390 str);
1391 } else {
1392 audit_log_format(ab, " data=");
1393 if (data_len > 0 && str[data_len - 1] == '\0')
1394 data_len--;
1395 audit_log_n_untrustedstring(ab, str, data_len);
1396 }
1397 audit_log_end(ab);
1398 }
1399 break;
1400 case AUDIT_ADD_RULE:
1401 case AUDIT_DEL_RULE:
1402 if (data_len < sizeof(struct audit_rule_data))
1403 return -EINVAL;
1404 if (audit_enabled == AUDIT_LOCKED) {
1405 audit_log_common_recv_msg(audit_context(), &ab,
1406 AUDIT_CONFIG_CHANGE);
1407 audit_log_format(ab, " op=%s audit_enabled=%d res=0",
1408 msg_type == AUDIT_ADD_RULE ?
1409 "add_rule" : "remove_rule",
1410 audit_enabled);
1411 audit_log_end(ab);
1412 return -EPERM;
1413 }
1414 err = audit_rule_change(msg_type, seq, data, data_len);
1415 break;
1416 case AUDIT_LIST_RULES:
1417 err = audit_list_rules_send(skb, seq);
1418 break;
1419 case AUDIT_TRIM:
1420 audit_trim_trees();
1421 audit_log_common_recv_msg(audit_context(), &ab,
1422 AUDIT_CONFIG_CHANGE);
1423 audit_log_format(ab, " op=trim res=1");
1424 audit_log_end(ab);
1425 break;
1426 case AUDIT_MAKE_EQUIV: {
1427 void *bufp = data;
1428 u32 sizes[2];
1429 size_t msglen = data_len;
1430 char *old, *new;
1431
1432 err = -EINVAL;
1433 if (msglen < 2 * sizeof(u32))
1434 break;
1435 memcpy(sizes, bufp, 2 * sizeof(u32));
1436 bufp += 2 * sizeof(u32);
1437 msglen -= 2 * sizeof(u32);
1438 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
1439 if (IS_ERR(old)) {
1440 err = PTR_ERR(old);
1441 break;
1442 }
1443 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
1444 if (IS_ERR(new)) {
1445 err = PTR_ERR(new);
1446 kfree(old);
1447 break;
1448 }
1449
1450 err = audit_tag_tree(old, new);
1451
1452 audit_log_common_recv_msg(audit_context(), &ab,
1453 AUDIT_CONFIG_CHANGE);
1454 audit_log_format(ab, " op=make_equiv old=");
1455 audit_log_untrustedstring(ab, old);
1456 audit_log_format(ab, " new=");
1457 audit_log_untrustedstring(ab, new);
1458 audit_log_format(ab, " res=%d", !err);
1459 audit_log_end(ab);
1460 kfree(old);
1461 kfree(new);
1462 break;
1463 }
1464 case AUDIT_SIGNAL_INFO:
1465 len = 0;
1466 if (audit_sig_sid) {
1467 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
1468 if (err)
1469 return err;
1470 }
1471 sig_data = kmalloc(struct_size(sig_data, ctx, len), GFP_KERNEL);
1472 if (!sig_data) {
1473 if (audit_sig_sid)
1474 security_release_secctx(ctx, len);
1475 return -ENOMEM;
1476 }
1477 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
1478 sig_data->pid = audit_sig_pid;
1479 if (audit_sig_sid) {
1480 memcpy(sig_data->ctx, ctx, len);
1481 security_release_secctx(ctx, len);
1482 }
1483 audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
1484 sig_data, struct_size(sig_data, ctx, len));
1485 kfree(sig_data);
1486 break;
1487 case AUDIT_TTY_GET: {
1488 struct audit_tty_status s;
1489 unsigned int t;
1490
1491 t = READ_ONCE(current->signal->audit_tty);
1492 s.enabled = t & AUDIT_TTY_ENABLE;
1493 s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
1494
1495 audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
1496 break;
1497 }
1498 case AUDIT_TTY_SET: {
1499 struct audit_tty_status s, old;
1500 struct audit_buffer *ab;
1501 unsigned int t;
1502
1503 memset(&s, 0, sizeof(s));
1504
1505 memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
1506
1507 if ((s.enabled != 0 && s.enabled != 1) ||
1508 (s.log_passwd != 0 && s.log_passwd != 1))
1509 err = -EINVAL;
1510
1511 if (err)
1512 t = READ_ONCE(current->signal->audit_tty);
1513 else {
1514 t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
1515 t = xchg(¤t->signal->audit_tty, t);
1516 }
1517 old.enabled = t & AUDIT_TTY_ENABLE;
1518 old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
1519
1520 audit_log_common_recv_msg(audit_context(), &ab,
1521 AUDIT_CONFIG_CHANGE);
1522 audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
1523 " old-log_passwd=%d new-log_passwd=%d res=%d",
1524 old.enabled, s.enabled, old.log_passwd,
1525 s.log_passwd, !err);
1526 audit_log_end(ab);
1527 break;
1528 }
1529 default:
1530 err = -EINVAL;
1531 break;
1532 }
1533
1534 return err < 0 ? err : 0;
1535}
1536
1537
1538
1539
1540
1541
1542
1543
1544static void audit_receive(struct sk_buff *skb)
1545{
1546 struct nlmsghdr *nlh;
1547
1548
1549
1550
1551 int len;
1552 int err;
1553
1554 nlh = nlmsg_hdr(skb);
1555 len = skb->len;
1556
1557 audit_ctl_lock();
1558 while (nlmsg_ok(nlh, len)) {
1559 err = audit_receive_msg(skb, nlh);
1560
1561 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
1562 netlink_ack(skb, nlh, err, NULL);
1563
1564 nlh = nlmsg_next(nlh, &len);
1565 }
1566 audit_ctl_unlock();
1567
1568
1569 if (audit_backlog_limit &&
1570 (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
1571 DECLARE_WAITQUEUE(wait, current);
1572
1573
1574 wake_up_interruptible(&kauditd_wait);
1575
1576 add_wait_queue_exclusive(&audit_backlog_wait, &wait);
1577 set_current_state(TASK_UNINTERRUPTIBLE);
1578 schedule_timeout(audit_backlog_wait_time);
1579 remove_wait_queue(&audit_backlog_wait, &wait);
1580 }
1581}
1582
1583
1584static void audit_log_multicast(int group, const char *op, int err)
1585{
1586 const struct cred *cred;
1587 struct tty_struct *tty;
1588 char comm[sizeof(current->comm)];
1589 struct audit_buffer *ab;
1590
1591 if (!audit_enabled)
1592 return;
1593
1594 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
1595 if (!ab)
1596 return;
1597
1598 cred = current_cred();
1599 tty = audit_get_tty();
1600 audit_log_format(ab, "pid=%u uid=%u auid=%u tty=%s ses=%u",
1601 task_pid_nr(current),
1602 from_kuid(&init_user_ns, cred->uid),
1603 from_kuid(&init_user_ns, audit_get_loginuid(current)),
1604 tty ? tty_name(tty) : "(none)",
1605 audit_get_sessionid(current));
1606 audit_put_tty(tty);
1607 audit_log_task_context(ab);
1608 audit_log_format(ab, " comm=");
1609 audit_log_untrustedstring(ab, get_task_comm(comm, current));
1610 audit_log_d_path_exe(ab, current->mm);
1611 audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
1612 audit_log_end(ab);
1613}
1614
1615
1616static int audit_multicast_bind(struct net *net, int group)
1617{
1618 int err = 0;
1619
1620 if (!capable(CAP_AUDIT_READ))
1621 err = -EPERM;
1622 audit_log_multicast(group, "connect", err);
1623 return err;
1624}
1625
1626static void audit_multicast_unbind(struct net *net, int group)
1627{
1628 audit_log_multicast(group, "disconnect", 0);
1629}
1630
1631static int __net_init audit_net_init(struct net *net)
1632{
1633 struct netlink_kernel_cfg cfg = {
1634 .input = audit_receive,
1635 .bind = audit_multicast_bind,
1636 .unbind = audit_multicast_unbind,
1637 .flags = NL_CFG_F_NONROOT_RECV,
1638 .groups = AUDIT_NLGRP_MAX,
1639 };
1640
1641 struct audit_net *aunet = net_generic(net, audit_net_id);
1642
1643 aunet->sk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
1644 if (aunet->sk == NULL) {
1645 audit_panic("cannot initialize netlink socket in namespace");
1646 return -ENOMEM;
1647 }
1648
1649 aunet->sk->sk_sndtimeo = HZ / 10;
1650
1651 return 0;
1652}
1653
1654static void __net_exit audit_net_exit(struct net *net)
1655{
1656 struct audit_net *aunet = net_generic(net, audit_net_id);
1657
1658
1659
1660
1661
1662
1663
1664 netlink_kernel_release(aunet->sk);
1665}
1666
1667static struct pernet_operations audit_net_ops __net_initdata = {
1668 .init = audit_net_init,
1669 .exit = audit_net_exit,
1670 .id = &audit_net_id,
1671 .size = sizeof(struct audit_net),
1672};
1673
1674
1675static int __init audit_init(void)
1676{
1677 int i;
1678
1679 if (audit_initialized == AUDIT_DISABLED)
1680 return 0;
1681
1682 audit_buffer_cache = kmem_cache_create("audit_buffer",
1683 sizeof(struct audit_buffer),
1684 0, SLAB_PANIC, NULL);
1685
1686 skb_queue_head_init(&audit_queue);
1687 skb_queue_head_init(&audit_retry_queue);
1688 skb_queue_head_init(&audit_hold_queue);
1689
1690 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1691 INIT_LIST_HEAD(&audit_inode_hash[i]);
1692
1693 mutex_init(&audit_cmd_mutex.lock);
1694 audit_cmd_mutex.owner = NULL;
1695
1696 pr_info("initializing netlink subsys (%s)\n",
1697 audit_default ? "enabled" : "disabled");
1698 register_pernet_subsys(&audit_net_ops);
1699
1700 audit_initialized = AUDIT_INITIALIZED;
1701
1702 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
1703 if (IS_ERR(kauditd_task)) {
1704 int err = PTR_ERR(kauditd_task);
1705 panic("audit: failed to start the kauditd thread (%d)\n", err);
1706 }
1707
1708 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL,
1709 "state=initialized audit_enabled=%u res=1",
1710 audit_enabled);
1711
1712 return 0;
1713}
1714postcore_initcall(audit_init);
1715
1716
1717
1718
1719
1720static int __init audit_enable(char *str)
1721{
1722 if (!strcasecmp(str, "off") || !strcmp(str, "0"))
1723 audit_default = AUDIT_OFF;
1724 else if (!strcasecmp(str, "on") || !strcmp(str, "1"))
1725 audit_default = AUDIT_ON;
1726 else {
1727 pr_err("audit: invalid 'audit' parameter value (%s)\n", str);
1728 audit_default = AUDIT_ON;
1729 }
1730
1731 if (audit_default == AUDIT_OFF)
1732 audit_initialized = AUDIT_DISABLED;
1733 if (audit_set_enabled(audit_default))
1734 pr_err("audit: error setting audit state (%d)\n",
1735 audit_default);
1736
1737 pr_info("%s\n", audit_default ?
1738 "enabled (after initialization)" : "disabled (until reboot)");
1739
1740 return 1;
1741}
1742__setup("audit=", audit_enable);
1743
1744
1745
1746static int __init audit_backlog_limit_set(char *str)
1747{
1748 u32 audit_backlog_limit_arg;
1749
1750 pr_info("audit_backlog_limit: ");
1751 if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
1752 pr_cont("using default of %u, unable to parse %s\n",
1753 audit_backlog_limit, str);
1754 return 1;
1755 }
1756
1757 audit_backlog_limit = audit_backlog_limit_arg;
1758 pr_cont("%d\n", audit_backlog_limit);
1759
1760 return 1;
1761}
1762__setup("audit_backlog_limit=", audit_backlog_limit_set);
1763
1764static void audit_buffer_free(struct audit_buffer *ab)
1765{
1766 if (!ab)
1767 return;
1768
1769 kfree_skb(ab->skb);
1770 kmem_cache_free(audit_buffer_cache, ab);
1771}
1772
1773static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx,
1774 gfp_t gfp_mask, int type)
1775{
1776 struct audit_buffer *ab;
1777
1778 ab = kmem_cache_alloc(audit_buffer_cache, gfp_mask);
1779 if (!ab)
1780 return NULL;
1781
1782 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1783 if (!ab->skb)
1784 goto err;
1785 if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0))
1786 goto err;
1787
1788 ab->ctx = ctx;
1789 ab->gfp_mask = gfp_mask;
1790
1791 return ab;
1792
1793err:
1794 audit_buffer_free(ab);
1795 return NULL;
1796}
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815unsigned int audit_serial(void)
1816{
1817 static atomic_t serial = ATOMIC_INIT(0);
1818
1819 return atomic_inc_return(&serial);
1820}
1821
1822static inline void audit_get_stamp(struct audit_context *ctx,
1823 struct timespec64 *t, unsigned int *serial)
1824{
1825 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1826 ktime_get_coarse_real_ts64(t);
1827 *serial = audit_serial();
1828 }
1829}
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1847 int type)
1848{
1849 struct audit_buffer *ab;
1850 struct timespec64 t;
1851 unsigned int serial;
1852
1853 if (audit_initialized != AUDIT_INITIALIZED)
1854 return NULL;
1855
1856 if (unlikely(!audit_filter(type, AUDIT_FILTER_EXCLUDE)))
1857 return NULL;
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868 if (!(auditd_test_task(current) || audit_ctl_owner_current())) {
1869 long stime = audit_backlog_wait_time;
1870
1871 while (audit_backlog_limit &&
1872 (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
1873
1874 wake_up_interruptible(&kauditd_wait);
1875
1876
1877
1878 if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) {
1879 long rtime = stime;
1880
1881 DECLARE_WAITQUEUE(wait, current);
1882
1883 add_wait_queue_exclusive(&audit_backlog_wait,
1884 &wait);
1885 set_current_state(TASK_UNINTERRUPTIBLE);
1886 stime = schedule_timeout(rtime);
1887 atomic_add(rtime - stime, &audit_backlog_wait_time_actual);
1888 remove_wait_queue(&audit_backlog_wait, &wait);
1889 } else {
1890 if (audit_rate_check() && printk_ratelimit())
1891 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1892 skb_queue_len(&audit_queue),
1893 audit_backlog_limit);
1894 audit_log_lost("backlog limit exceeded");
1895 return NULL;
1896 }
1897 }
1898 }
1899
1900 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1901 if (!ab) {
1902 audit_log_lost("out of memory in audit_log_start");
1903 return NULL;
1904 }
1905
1906 audit_get_stamp(ab->ctx, &t, &serial);
1907
1908 if (ctx)
1909 ctx->dummy = 0;
1910 audit_log_format(ab, "audit(%llu.%03lu:%u): ",
1911 (unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial);
1912
1913 return ab;
1914}
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924static inline int audit_expand(struct audit_buffer *ab, int extra)
1925{
1926 struct sk_buff *skb = ab->skb;
1927 int oldtail = skb_tailroom(skb);
1928 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1929 int newtail = skb_tailroom(skb);
1930
1931 if (ret < 0) {
1932 audit_log_lost("out of memory in audit_expand");
1933 return 0;
1934 }
1935
1936 skb->truesize += newtail - oldtail;
1937 return newtail;
1938}
1939
1940
1941
1942
1943
1944
1945
1946static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1947 va_list args)
1948{
1949 int len, avail;
1950 struct sk_buff *skb;
1951 va_list args2;
1952
1953 if (!ab)
1954 return;
1955
1956 BUG_ON(!ab->skb);
1957 skb = ab->skb;
1958 avail = skb_tailroom(skb);
1959 if (avail == 0) {
1960 avail = audit_expand(ab, AUDIT_BUFSIZ);
1961 if (!avail)
1962 goto out;
1963 }
1964 va_copy(args2, args);
1965 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1966 if (len >= avail) {
1967
1968
1969
1970 avail = audit_expand(ab,
1971 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1972 if (!avail)
1973 goto out_va_end;
1974 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1975 }
1976 if (len > 0)
1977 skb_put(skb, len);
1978out_va_end:
1979 va_end(args2);
1980out:
1981 return;
1982}
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1993{
1994 va_list args;
1995
1996 if (!ab)
1997 return;
1998 va_start(args, fmt);
1999 audit_log_vformat(ab, fmt, args);
2000 va_end(args);
2001}
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
2015 size_t len)
2016{
2017 int i, avail, new_len;
2018 unsigned char *ptr;
2019 struct sk_buff *skb;
2020
2021 if (!ab)
2022 return;
2023
2024 BUG_ON(!ab->skb);
2025 skb = ab->skb;
2026 avail = skb_tailroom(skb);
2027 new_len = len<<1;
2028 if (new_len >= avail) {
2029
2030 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
2031 avail = audit_expand(ab, new_len);
2032 if (!avail)
2033 return;
2034 }
2035
2036 ptr = skb_tail_pointer(skb);
2037 for (i = 0; i < len; i++)
2038 ptr = hex_byte_pack_upper(ptr, buf[i]);
2039 *ptr = 0;
2040 skb_put(skb, len << 1);
2041}
2042
2043
2044
2045
2046
2047void audit_log_n_string(struct audit_buffer *ab, const char *string,
2048 size_t slen)
2049{
2050 int avail, new_len;
2051 unsigned char *ptr;
2052 struct sk_buff *skb;
2053
2054 if (!ab)
2055 return;
2056
2057 BUG_ON(!ab->skb);
2058 skb = ab->skb;
2059 avail = skb_tailroom(skb);
2060 new_len = slen + 3;
2061 if (new_len > avail) {
2062 avail = audit_expand(ab, new_len);
2063 if (!avail)
2064 return;
2065 }
2066 ptr = skb_tail_pointer(skb);
2067 *ptr++ = '"';
2068 memcpy(ptr, string, slen);
2069 ptr += slen;
2070 *ptr++ = '"';
2071 *ptr = 0;
2072 skb_put(skb, slen + 2);
2073}
2074
2075
2076
2077
2078
2079
2080bool audit_string_contains_control(const char *string, size_t len)
2081{
2082 const unsigned char *p;
2083 for (p = string; p < (const unsigned char *)string + len; p++) {
2084 if (*p == '"' || *p < 0x21 || *p > 0x7e)
2085 return true;
2086 }
2087 return false;
2088}
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
2105 size_t len)
2106{
2107 if (audit_string_contains_control(string, len))
2108 audit_log_n_hex(ab, string, len);
2109 else
2110 audit_log_n_string(ab, string, len);
2111}
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
2122{
2123 audit_log_n_untrustedstring(ab, string, strlen(string));
2124}
2125
2126
2127void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
2128 const struct path *path)
2129{
2130 char *p, *pathname;
2131
2132 if (prefix)
2133 audit_log_format(ab, "%s", prefix);
2134
2135
2136 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
2137 if (!pathname) {
2138 audit_log_format(ab, "\"<no_memory>\"");
2139 return;
2140 }
2141 p = d_path(path, pathname, PATH_MAX+11);
2142 if (IS_ERR(p)) {
2143
2144 audit_log_format(ab, "\"<too_long>\"");
2145 } else
2146 audit_log_untrustedstring(ab, p);
2147 kfree(pathname);
2148}
2149
2150void audit_log_session_info(struct audit_buffer *ab)
2151{
2152 unsigned int sessionid = audit_get_sessionid(current);
2153 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
2154
2155 audit_log_format(ab, "auid=%u ses=%u", auid, sessionid);
2156}
2157
2158void audit_log_key(struct audit_buffer *ab, char *key)
2159{
2160 audit_log_format(ab, " key=");
2161 if (key)
2162 audit_log_untrustedstring(ab, key);
2163 else
2164 audit_log_format(ab, "(null)");
2165}
2166
2167int audit_log_task_context(struct audit_buffer *ab)
2168{
2169 char *ctx = NULL;
2170 unsigned len;
2171 int error;
2172 u32 sid;
2173
2174 security_current_getsecid_subj(&sid);
2175 if (!sid)
2176 return 0;
2177
2178 error = security_secid_to_secctx(sid, &ctx, &len);
2179 if (error) {
2180 if (error != -EINVAL)
2181 goto error_path;
2182 return 0;
2183 }
2184
2185 audit_log_format(ab, " subj=%s", ctx);
2186 security_release_secctx(ctx, len);
2187 return 0;
2188
2189error_path:
2190 audit_panic("error in audit_log_task_context");
2191 return error;
2192}
2193EXPORT_SYMBOL(audit_log_task_context);
2194
2195void audit_log_d_path_exe(struct audit_buffer *ab,
2196 struct mm_struct *mm)
2197{
2198 struct file *exe_file;
2199
2200 if (!mm)
2201 goto out_null;
2202
2203 exe_file = get_mm_exe_file(mm);
2204 if (!exe_file)
2205 goto out_null;
2206
2207 audit_log_d_path(ab, " exe=", &exe_file->f_path);
2208 fput(exe_file);
2209 return;
2210out_null:
2211 audit_log_format(ab, " exe=(null)");
2212}
2213
2214struct tty_struct *audit_get_tty(void)
2215{
2216 struct tty_struct *tty = NULL;
2217 unsigned long flags;
2218
2219 spin_lock_irqsave(¤t->sighand->siglock, flags);
2220 if (current->signal)
2221 tty = tty_kref_get(current->signal->tty);
2222 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
2223 return tty;
2224}
2225
2226void audit_put_tty(struct tty_struct *tty)
2227{
2228 tty_kref_put(tty);
2229}
2230
2231void audit_log_task_info(struct audit_buffer *ab)
2232{
2233 const struct cred *cred;
2234 char comm[sizeof(current->comm)];
2235 struct tty_struct *tty;
2236
2237 if (!ab)
2238 return;
2239
2240 cred = current_cred();
2241 tty = audit_get_tty();
2242 audit_log_format(ab,
2243 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
2244 " euid=%u suid=%u fsuid=%u"
2245 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
2246 task_ppid_nr(current),
2247 task_tgid_nr(current),
2248 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2249 from_kuid(&init_user_ns, cred->uid),
2250 from_kgid(&init_user_ns, cred->gid),
2251 from_kuid(&init_user_ns, cred->euid),
2252 from_kuid(&init_user_ns, cred->suid),
2253 from_kuid(&init_user_ns, cred->fsuid),
2254 from_kgid(&init_user_ns, cred->egid),
2255 from_kgid(&init_user_ns, cred->sgid),
2256 from_kgid(&init_user_ns, cred->fsgid),
2257 tty ? tty_name(tty) : "(none)",
2258 audit_get_sessionid(current));
2259 audit_put_tty(tty);
2260 audit_log_format(ab, " comm=");
2261 audit_log_untrustedstring(ab, get_task_comm(comm, current));
2262 audit_log_d_path_exe(ab, current->mm);
2263 audit_log_task_context(ab);
2264}
2265EXPORT_SYMBOL(audit_log_task_info);
2266
2267
2268
2269
2270
2271
2272void audit_log_path_denied(int type, const char *operation)
2273{
2274 struct audit_buffer *ab;
2275
2276 if (!audit_enabled || audit_dummy_context())
2277 return;
2278
2279
2280 ab = audit_log_start(audit_context(), GFP_KERNEL, type);
2281 if (!ab)
2282 return;
2283 audit_log_format(ab, "op=%s", operation);
2284 audit_log_task_info(ab);
2285 audit_log_format(ab, " res=0");
2286 audit_log_end(ab);
2287}
2288
2289
2290static atomic_t session_id = ATOMIC_INIT(0);
2291
2292static int audit_set_loginuid_perm(kuid_t loginuid)
2293{
2294
2295 if (!audit_loginuid_set(current))
2296 return 0;
2297
2298 if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
2299 return -EPERM;
2300
2301 if (!capable(CAP_AUDIT_CONTROL))
2302 return -EPERM;
2303
2304 if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID)
2305 && uid_valid(loginuid))
2306 return -EPERM;
2307 return 0;
2308}
2309
2310static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
2311 unsigned int oldsessionid,
2312 unsigned int sessionid, int rc)
2313{
2314 struct audit_buffer *ab;
2315 uid_t uid, oldloginuid, loginuid;
2316 struct tty_struct *tty;
2317
2318 if (!audit_enabled)
2319 return;
2320
2321 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_LOGIN);
2322 if (!ab)
2323 return;
2324
2325 uid = from_kuid(&init_user_ns, task_uid(current));
2326 oldloginuid = from_kuid(&init_user_ns, koldloginuid);
2327 loginuid = from_kuid(&init_user_ns, kloginuid);
2328 tty = audit_get_tty();
2329
2330 audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
2331 audit_log_task_context(ab);
2332 audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
2333 oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
2334 oldsessionid, sessionid, !rc);
2335 audit_put_tty(tty);
2336 audit_log_end(ab);
2337}
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347int audit_set_loginuid(kuid_t loginuid)
2348{
2349 unsigned int oldsessionid, sessionid = AUDIT_SID_UNSET;
2350 kuid_t oldloginuid;
2351 int rc;
2352
2353 oldloginuid = audit_get_loginuid(current);
2354 oldsessionid = audit_get_sessionid(current);
2355
2356 rc = audit_set_loginuid_perm(loginuid);
2357 if (rc)
2358 goto out;
2359
2360
2361 if (uid_valid(loginuid)) {
2362 sessionid = (unsigned int)atomic_inc_return(&session_id);
2363 if (unlikely(sessionid == AUDIT_SID_UNSET))
2364 sessionid = (unsigned int)atomic_inc_return(&session_id);
2365 }
2366
2367 current->sessionid = sessionid;
2368 current->loginuid = loginuid;
2369out:
2370 audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
2371 return rc;
2372}
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382int audit_signal_info(int sig, struct task_struct *t)
2383{
2384 kuid_t uid = current_uid(), auid;
2385
2386 if (auditd_test_task(t) &&
2387 (sig == SIGTERM || sig == SIGHUP ||
2388 sig == SIGUSR1 || sig == SIGUSR2)) {
2389 audit_sig_pid = task_tgid_nr(current);
2390 auid = audit_get_loginuid(current);
2391 if (uid_valid(auid))
2392 audit_sig_uid = auid;
2393 else
2394 audit_sig_uid = uid;
2395 security_current_getsecid_subj(&audit_sig_sid);
2396 }
2397
2398 return audit_signal_info_syscall(t);
2399}
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410void audit_log_end(struct audit_buffer *ab)
2411{
2412 struct sk_buff *skb;
2413 struct nlmsghdr *nlh;
2414
2415 if (!ab)
2416 return;
2417
2418 if (audit_rate_check()) {
2419 skb = ab->skb;
2420 ab->skb = NULL;
2421
2422
2423
2424 nlh = nlmsg_hdr(skb);
2425 nlh->nlmsg_len = skb->len - NLMSG_HDRLEN;
2426
2427
2428 skb_queue_tail(&audit_queue, skb);
2429 wake_up_interruptible(&kauditd_wait);
2430 } else
2431 audit_log_lost("rate limit exceeded");
2432
2433 audit_buffer_free(ab);
2434}
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
2449 const char *fmt, ...)
2450{
2451 struct audit_buffer *ab;
2452 va_list args;
2453
2454 ab = audit_log_start(ctx, gfp_mask, type);
2455 if (ab) {
2456 va_start(args, fmt);
2457 audit_log_vformat(ab, fmt, args);
2458 va_end(args);
2459 audit_log_end(ab);
2460 }
2461}
2462
2463EXPORT_SYMBOL(audit_log_start);
2464EXPORT_SYMBOL(audit_log_end);
2465EXPORT_SYMBOL(audit_log_format);
2466EXPORT_SYMBOL(audit_log);
2467