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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
549static void kauditd_rehold_skb(struct sk_buff *skb)
550{
551
552 skb_queue_head(&audit_hold_queue, skb);
553}
554
555
556
557
558
559
560
561
562
563
564
565
566
567static void kauditd_hold_skb(struct sk_buff *skb)
568{
569
570
571 kauditd_printk_skb(skb);
572
573
574 if (!audit_default) {
575 kfree_skb(skb);
576 return;
577 }
578
579
580 if (!audit_backlog_limit ||
581 skb_queue_len(&audit_hold_queue) < audit_backlog_limit) {
582 skb_queue_tail(&audit_hold_queue, skb);
583 return;
584 }
585
586
587 audit_log_lost("kauditd hold queue overflow");
588 kfree_skb(skb);
589}
590
591
592
593
594
595
596
597
598
599
600static void kauditd_retry_skb(struct sk_buff *skb)
601{
602
603
604
605 skb_queue_tail(&audit_retry_queue, skb);
606}
607
608
609
610
611
612
613
614
615
616
617
618
619static void auditd_reset(const struct auditd_connection *ac)
620{
621 unsigned long flags;
622 struct sk_buff *skb;
623 struct auditd_connection *ac_old;
624
625
626 spin_lock_irqsave(&auditd_conn_lock, flags);
627 ac_old = rcu_dereference_protected(auditd_conn,
628 lockdep_is_held(&auditd_conn_lock));
629 if (ac && ac != ac_old) {
630
631 spin_unlock_irqrestore(&auditd_conn_lock, flags);
632 return;
633 }
634 rcu_assign_pointer(auditd_conn, NULL);
635 spin_unlock_irqrestore(&auditd_conn_lock, flags);
636
637 if (ac_old)
638 call_rcu(&ac_old->rcu, auditd_conn_free);
639
640
641
642 while ((skb = skb_dequeue(&audit_retry_queue)))
643 kauditd_hold_skb(skb);
644}
645
646
647
648
649
650
651
652
653
654
655
656
657static int auditd_send_unicast_skb(struct sk_buff *skb)
658{
659 int rc;
660 u32 portid;
661 struct net *net;
662 struct sock *sk;
663 struct auditd_connection *ac;
664
665
666
667
668
669
670
671
672 rcu_read_lock();
673 ac = rcu_dereference(auditd_conn);
674 if (!ac) {
675 rcu_read_unlock();
676 kfree_skb(skb);
677 rc = -ECONNREFUSED;
678 goto err;
679 }
680 net = get_net(ac->net);
681 sk = audit_get_sk(net);
682 portid = ac->portid;
683 rcu_read_unlock();
684
685 rc = netlink_unicast(sk, skb, portid, 0);
686 put_net(net);
687 if (rc < 0)
688 goto err;
689
690 return rc;
691
692err:
693 if (ac && rc == -ECONNREFUSED)
694 auditd_reset(ac);
695 return rc;
696}
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713static int kauditd_send_queue(struct sock *sk, u32 portid,
714 struct sk_buff_head *queue,
715 unsigned int retry_limit,
716 void (*skb_hook)(struct sk_buff *skb),
717 void (*err_hook)(struct sk_buff *skb))
718{
719 int rc = 0;
720 struct sk_buff *skb;
721 static unsigned int failed = 0;
722
723
724
725
726 while ((skb = skb_dequeue(queue))) {
727
728 if (skb_hook)
729 (*skb_hook)(skb);
730
731
732 if (!sk) {
733 if (err_hook)
734 (*err_hook)(skb);
735 continue;
736 }
737
738
739 skb_get(skb);
740 rc = netlink_unicast(sk, skb, portid, 0);
741 if (rc < 0) {
742
743 if (++failed >= retry_limit ||
744 rc == -ECONNREFUSED || rc == -EPERM) {
745
746 sk = NULL;
747 if (err_hook)
748 (*err_hook)(skb);
749 if (!skb_hook)
750 goto out;
751
752 continue;
753 } else
754
755 skb_queue_head(queue, skb);
756 } else {
757
758 consume_skb(skb);
759 failed = 0;
760 }
761 }
762
763out:
764 return (rc >= 0 ? 0 : rc);
765}
766
767
768
769
770
771
772
773
774
775
776static void kauditd_send_multicast_skb(struct sk_buff *skb)
777{
778 struct sk_buff *copy;
779 struct sock *sock = audit_get_sk(&init_net);
780 struct nlmsghdr *nlh;
781
782
783
784
785 if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
786 return;
787
788
789
790
791
792
793
794
795
796
797
798 copy = skb_copy(skb, GFP_KERNEL);
799 if (!copy)
800 return;
801 nlh = nlmsg_hdr(copy);
802 nlh->nlmsg_len = skb->len;
803
804 nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL);
805}
806
807
808
809
810
811static int kauditd_thread(void *dummy)
812{
813 int rc;
814 u32 portid = 0;
815 struct net *net = NULL;
816 struct sock *sk = NULL;
817 struct auditd_connection *ac;
818
819#define UNICAST_RETRIES 5
820
821 set_freezable();
822 while (!kthread_should_stop()) {
823
824 rcu_read_lock();
825 ac = rcu_dereference(auditd_conn);
826 if (!ac) {
827 rcu_read_unlock();
828 goto main_queue;
829 }
830 net = get_net(ac->net);
831 sk = audit_get_sk(net);
832 portid = ac->portid;
833 rcu_read_unlock();
834
835
836 rc = kauditd_send_queue(sk, portid,
837 &audit_hold_queue, UNICAST_RETRIES,
838 NULL, kauditd_rehold_skb);
839 if (rc < 0) {
840 sk = NULL;
841 auditd_reset(ac);
842 goto main_queue;
843 }
844
845
846 rc = kauditd_send_queue(sk, portid,
847 &audit_retry_queue, UNICAST_RETRIES,
848 NULL, kauditd_hold_skb);
849 if (rc < 0) {
850 sk = NULL;
851 auditd_reset(ac);
852 goto main_queue;
853 }
854
855main_queue:
856
857
858
859
860 rc = kauditd_send_queue(sk, portid, &audit_queue, 1,
861 kauditd_send_multicast_skb,
862 (sk ?
863 kauditd_retry_skb : kauditd_hold_skb));
864 if (ac && rc < 0)
865 auditd_reset(ac);
866 sk = NULL;
867
868
869 if (net) {
870 put_net(net);
871 net = NULL;
872 }
873
874
875 wake_up(&audit_backlog_wait);
876
877
878
879
880
881 wait_event_freezable(kauditd_wait,
882 (skb_queue_len(&audit_queue) ? 1 : 0));
883 }
884
885 return 0;
886}
887
888int audit_send_list_thread(void *_dest)
889{
890 struct audit_netlink_list *dest = _dest;
891 struct sk_buff *skb;
892 struct sock *sk = audit_get_sk(dest->net);
893
894
895 audit_ctl_lock();
896 audit_ctl_unlock();
897
898 while ((skb = __skb_dequeue(&dest->q)) != NULL)
899 netlink_unicast(sk, skb, dest->portid, 0);
900
901 put_net(dest->net);
902 kfree(dest);
903
904 return 0;
905}
906
907struct sk_buff *audit_make_reply(int seq, int type, int done,
908 int multi, const void *payload, int size)
909{
910 struct sk_buff *skb;
911 struct nlmsghdr *nlh;
912 void *data;
913 int flags = multi ? NLM_F_MULTI : 0;
914 int t = done ? NLMSG_DONE : type;
915
916 skb = nlmsg_new(size, GFP_KERNEL);
917 if (!skb)
918 return NULL;
919
920 nlh = nlmsg_put(skb, 0, seq, t, size, flags);
921 if (!nlh)
922 goto out_kfree_skb;
923 data = nlmsg_data(nlh);
924 memcpy(data, payload, size);
925 return skb;
926
927out_kfree_skb:
928 kfree_skb(skb);
929 return NULL;
930}
931
932static void audit_free_reply(struct audit_reply *reply)
933{
934 if (!reply)
935 return;
936
937 kfree_skb(reply->skb);
938 if (reply->net)
939 put_net(reply->net);
940 kfree(reply);
941}
942
943static int audit_send_reply_thread(void *arg)
944{
945 struct audit_reply *reply = (struct audit_reply *)arg;
946
947 audit_ctl_lock();
948 audit_ctl_unlock();
949
950
951
952 netlink_unicast(audit_get_sk(reply->net), reply->skb, reply->portid, 0);
953 reply->skb = NULL;
954 audit_free_reply(reply);
955 return 0;
956}
957
958
959
960
961
962
963
964
965
966
967
968
969
970static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
971 int multi, const void *payload, int size)
972{
973 struct task_struct *tsk;
974 struct audit_reply *reply;
975
976 reply = kzalloc(sizeof(*reply), GFP_KERNEL);
977 if (!reply)
978 return;
979
980 reply->skb = audit_make_reply(seq, type, done, multi, payload, size);
981 if (!reply->skb)
982 goto err;
983 reply->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
984 reply->portid = NETLINK_CB(request_skb).portid;
985
986 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
987 if (IS_ERR(tsk))
988 goto err;
989
990 return;
991
992err:
993 audit_free_reply(reply);
994}
995
996
997
998
999
1000static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
1001{
1002 int err = 0;
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015 if (current_user_ns() != &init_user_ns)
1016 return -ECONNREFUSED;
1017
1018 switch (msg_type) {
1019 case AUDIT_LIST:
1020 case AUDIT_ADD:
1021 case AUDIT_DEL:
1022 return -EOPNOTSUPP;
1023 case AUDIT_GET:
1024 case AUDIT_SET:
1025 case AUDIT_GET_FEATURE:
1026 case AUDIT_SET_FEATURE:
1027 case AUDIT_LIST_RULES:
1028 case AUDIT_ADD_RULE:
1029 case AUDIT_DEL_RULE:
1030 case AUDIT_SIGNAL_INFO:
1031 case AUDIT_TTY_GET:
1032 case AUDIT_TTY_SET:
1033 case AUDIT_TRIM:
1034 case AUDIT_MAKE_EQUIV:
1035
1036
1037 if (task_active_pid_ns(current) != &init_pid_ns)
1038 return -EPERM;
1039
1040 if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
1041 err = -EPERM;
1042 break;
1043 case AUDIT_USER:
1044 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
1045 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
1046 if (!netlink_capable(skb, CAP_AUDIT_WRITE))
1047 err = -EPERM;
1048 break;
1049 default:
1050 err = -EINVAL;
1051 }
1052
1053 return err;
1054}
1055
1056static void audit_log_common_recv_msg(struct audit_context *context,
1057 struct audit_buffer **ab, u16 msg_type)
1058{
1059 uid_t uid = from_kuid(&init_user_ns, current_uid());
1060 pid_t pid = task_tgid_nr(current);
1061
1062 if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
1063 *ab = NULL;
1064 return;
1065 }
1066
1067 *ab = audit_log_start(context, GFP_KERNEL, msg_type);
1068 if (unlikely(!*ab))
1069 return;
1070 audit_log_format(*ab, "pid=%d uid=%u ", pid, uid);
1071 audit_log_session_info(*ab);
1072 audit_log_task_context(*ab);
1073}
1074
1075static inline void audit_log_user_recv_msg(struct audit_buffer **ab,
1076 u16 msg_type)
1077{
1078 audit_log_common_recv_msg(NULL, ab, msg_type);
1079}
1080
1081int is_audit_feature_set(int i)
1082{
1083 return af.features & AUDIT_FEATURE_TO_MASK(i);
1084}
1085
1086
1087static int audit_get_feature(struct sk_buff *skb)
1088{
1089 u32 seq;
1090
1091 seq = nlmsg_hdr(skb)->nlmsg_seq;
1092
1093 audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
1094
1095 return 0;
1096}
1097
1098static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
1099 u32 old_lock, u32 new_lock, int res)
1100{
1101 struct audit_buffer *ab;
1102
1103 if (audit_enabled == AUDIT_OFF)
1104 return;
1105
1106 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_FEATURE_CHANGE);
1107 if (!ab)
1108 return;
1109 audit_log_task_info(ab);
1110 audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
1111 audit_feature_names[which], !!old_feature, !!new_feature,
1112 !!old_lock, !!new_lock, res);
1113 audit_log_end(ab);
1114}
1115
1116static int audit_set_feature(struct audit_features *uaf)
1117{
1118 int i;
1119
1120 BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
1121
1122
1123
1124 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1125 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1126 u32 old_feature, new_feature, old_lock, new_lock;
1127
1128
1129 if (!(feature & uaf->mask))
1130 continue;
1131
1132 old_feature = af.features & feature;
1133 new_feature = uaf->features & feature;
1134 new_lock = (uaf->lock | af.lock) & feature;
1135 old_lock = af.lock & feature;
1136
1137
1138 if (old_lock && (new_feature != old_feature)) {
1139 audit_log_feature_change(i, old_feature, new_feature,
1140 old_lock, new_lock, 0);
1141 return -EPERM;
1142 }
1143 }
1144
1145 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1146 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1147 u32 old_feature, new_feature, old_lock, new_lock;
1148
1149
1150 if (!(feature & uaf->mask))
1151 continue;
1152
1153 old_feature = af.features & feature;
1154 new_feature = uaf->features & feature;
1155 old_lock = af.lock & feature;
1156 new_lock = (uaf->lock | af.lock) & feature;
1157
1158 if (new_feature != old_feature)
1159 audit_log_feature_change(i, old_feature, new_feature,
1160 old_lock, new_lock, 1);
1161
1162 if (new_feature)
1163 af.features |= feature;
1164 else
1165 af.features &= ~feature;
1166 af.lock |= new_lock;
1167 }
1168
1169 return 0;
1170}
1171
1172static int audit_replace(struct pid *pid)
1173{
1174 pid_t pvnr;
1175 struct sk_buff *skb;
1176
1177 pvnr = pid_vnr(pid);
1178 skb = audit_make_reply(0, AUDIT_REPLACE, 0, 0, &pvnr, sizeof(pvnr));
1179 if (!skb)
1180 return -ENOMEM;
1181 return auditd_send_unicast_skb(skb);
1182}
1183
1184static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1185{
1186 u32 seq;
1187 void *data;
1188 int data_len;
1189 int err;
1190 struct audit_buffer *ab;
1191 u16 msg_type = nlh->nlmsg_type;
1192 struct audit_sig_info *sig_data;
1193 char *ctx = NULL;
1194 u32 len;
1195
1196 err = audit_netlink_ok(skb, msg_type);
1197 if (err)
1198 return err;
1199
1200 seq = nlh->nlmsg_seq;
1201 data = nlmsg_data(nlh);
1202 data_len = nlmsg_len(nlh);
1203
1204 switch (msg_type) {
1205 case AUDIT_GET: {
1206 struct audit_status s;
1207 memset(&s, 0, sizeof(s));
1208 s.enabled = audit_enabled;
1209 s.failure = audit_failure;
1210
1211
1212 s.pid = auditd_pid_vnr();
1213 s.rate_limit = audit_rate_limit;
1214 s.backlog_limit = audit_backlog_limit;
1215 s.lost = atomic_read(&audit_lost);
1216 s.backlog = skb_queue_len(&audit_queue);
1217 s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
1218 s.backlog_wait_time = audit_backlog_wait_time;
1219 s.backlog_wait_time_actual = atomic_read(&audit_backlog_wait_time_actual);
1220 audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
1221 break;
1222 }
1223 case AUDIT_SET: {
1224 struct audit_status s;
1225 memset(&s, 0, sizeof(s));
1226
1227 memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
1228 if (s.mask & AUDIT_STATUS_ENABLED) {
1229 err = audit_set_enabled(s.enabled);
1230 if (err < 0)
1231 return err;
1232 }
1233 if (s.mask & AUDIT_STATUS_FAILURE) {
1234 err = audit_set_failure(s.failure);
1235 if (err < 0)
1236 return err;
1237 }
1238 if (s.mask & AUDIT_STATUS_PID) {
1239
1240
1241
1242
1243
1244
1245 pid_t new_pid = s.pid;
1246 pid_t auditd_pid;
1247 struct pid *req_pid = task_tgid(current);
1248
1249
1250
1251 if (new_pid && (new_pid != pid_vnr(req_pid)))
1252 return -EINVAL;
1253
1254
1255 audit_replace(req_pid);
1256
1257 auditd_pid = auditd_pid_vnr();
1258 if (auditd_pid) {
1259
1260 if (new_pid) {
1261 audit_log_config_change("audit_pid",
1262 new_pid, auditd_pid, 0);
1263 return -EEXIST;
1264 }
1265
1266 if (pid_vnr(req_pid) != auditd_pid) {
1267 audit_log_config_change("audit_pid",
1268 new_pid, auditd_pid, 0);
1269 return -EACCES;
1270 }
1271 }
1272
1273 if (new_pid) {
1274
1275 err = auditd_set(req_pid,
1276 NETLINK_CB(skb).portid,
1277 sock_net(NETLINK_CB(skb).sk));
1278 if (audit_enabled != AUDIT_OFF)
1279 audit_log_config_change("audit_pid",
1280 new_pid,
1281 auditd_pid,
1282 err ? 0 : 1);
1283 if (err)
1284 return err;
1285
1286
1287 wake_up_interruptible(&kauditd_wait);
1288 } else {
1289 if (audit_enabled != AUDIT_OFF)
1290 audit_log_config_change("audit_pid",
1291 new_pid,
1292 auditd_pid, 1);
1293
1294
1295 auditd_reset(NULL);
1296 }
1297 }
1298 if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
1299 err = audit_set_rate_limit(s.rate_limit);
1300 if (err < 0)
1301 return err;
1302 }
1303 if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
1304 err = audit_set_backlog_limit(s.backlog_limit);
1305 if (err < 0)
1306 return err;
1307 }
1308 if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
1309 if (sizeof(s) > (size_t)nlh->nlmsg_len)
1310 return -EINVAL;
1311 if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
1312 return -EINVAL;
1313 err = audit_set_backlog_wait_time(s.backlog_wait_time);
1314 if (err < 0)
1315 return err;
1316 }
1317 if (s.mask == AUDIT_STATUS_LOST) {
1318 u32 lost = atomic_xchg(&audit_lost, 0);
1319
1320 audit_log_config_change("lost", 0, lost, 1);
1321 return lost;
1322 }
1323 if (s.mask == AUDIT_STATUS_BACKLOG_WAIT_TIME_ACTUAL) {
1324 u32 actual = atomic_xchg(&audit_backlog_wait_time_actual, 0);
1325
1326 audit_log_config_change("backlog_wait_time_actual", 0, actual, 1);
1327 return actual;
1328 }
1329 break;
1330 }
1331 case AUDIT_GET_FEATURE:
1332 err = audit_get_feature(skb);
1333 if (err)
1334 return err;
1335 break;
1336 case AUDIT_SET_FEATURE:
1337 if (data_len < sizeof(struct audit_features))
1338 return -EINVAL;
1339 err = audit_set_feature(data);
1340 if (err)
1341 return err;
1342 break;
1343 case AUDIT_USER:
1344 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
1345 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
1346 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
1347 return 0;
1348
1349 if (data_len < 2)
1350 return -EINVAL;
1351
1352 err = audit_filter(msg_type, AUDIT_FILTER_USER);
1353 if (err == 1) {
1354 char *str = data;
1355
1356 err = 0;
1357 if (msg_type == AUDIT_USER_TTY) {
1358 err = tty_audit_push();
1359 if (err)
1360 break;
1361 }
1362 audit_log_user_recv_msg(&ab, msg_type);
1363 if (msg_type != AUDIT_USER_TTY) {
1364
1365 str[data_len - 1] = '\0';
1366 audit_log_format(ab, " msg='%.*s'",
1367 AUDIT_MESSAGE_TEXT_MAX,
1368 str);
1369 } else {
1370 audit_log_format(ab, " data=");
1371 if (data_len > 0 && str[data_len - 1] == '\0')
1372 data_len--;
1373 audit_log_n_untrustedstring(ab, str, data_len);
1374 }
1375 audit_log_end(ab);
1376 }
1377 break;
1378 case AUDIT_ADD_RULE:
1379 case AUDIT_DEL_RULE:
1380 if (data_len < sizeof(struct audit_rule_data))
1381 return -EINVAL;
1382 if (audit_enabled == AUDIT_LOCKED) {
1383 audit_log_common_recv_msg(audit_context(), &ab,
1384 AUDIT_CONFIG_CHANGE);
1385 audit_log_format(ab, " op=%s audit_enabled=%d res=0",
1386 msg_type == AUDIT_ADD_RULE ?
1387 "add_rule" : "remove_rule",
1388 audit_enabled);
1389 audit_log_end(ab);
1390 return -EPERM;
1391 }
1392 err = audit_rule_change(msg_type, seq, data, data_len);
1393 break;
1394 case AUDIT_LIST_RULES:
1395 err = audit_list_rules_send(skb, seq);
1396 break;
1397 case AUDIT_TRIM:
1398 audit_trim_trees();
1399 audit_log_common_recv_msg(audit_context(), &ab,
1400 AUDIT_CONFIG_CHANGE);
1401 audit_log_format(ab, " op=trim res=1");
1402 audit_log_end(ab);
1403 break;
1404 case AUDIT_MAKE_EQUIV: {
1405 void *bufp = data;
1406 u32 sizes[2];
1407 size_t msglen = data_len;
1408 char *old, *new;
1409
1410 err = -EINVAL;
1411 if (msglen < 2 * sizeof(u32))
1412 break;
1413 memcpy(sizes, bufp, 2 * sizeof(u32));
1414 bufp += 2 * sizeof(u32);
1415 msglen -= 2 * sizeof(u32);
1416 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
1417 if (IS_ERR(old)) {
1418 err = PTR_ERR(old);
1419 break;
1420 }
1421 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
1422 if (IS_ERR(new)) {
1423 err = PTR_ERR(new);
1424 kfree(old);
1425 break;
1426 }
1427
1428 err = audit_tag_tree(old, new);
1429
1430 audit_log_common_recv_msg(audit_context(), &ab,
1431 AUDIT_CONFIG_CHANGE);
1432 audit_log_format(ab, " op=make_equiv old=");
1433 audit_log_untrustedstring(ab, old);
1434 audit_log_format(ab, " new=");
1435 audit_log_untrustedstring(ab, new);
1436 audit_log_format(ab, " res=%d", !err);
1437 audit_log_end(ab);
1438 kfree(old);
1439 kfree(new);
1440 break;
1441 }
1442 case AUDIT_SIGNAL_INFO:
1443 len = 0;
1444 if (audit_sig_sid) {
1445 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
1446 if (err)
1447 return err;
1448 }
1449 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
1450 if (!sig_data) {
1451 if (audit_sig_sid)
1452 security_release_secctx(ctx, len);
1453 return -ENOMEM;
1454 }
1455 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
1456 sig_data->pid = audit_sig_pid;
1457 if (audit_sig_sid) {
1458 memcpy(sig_data->ctx, ctx, len);
1459 security_release_secctx(ctx, len);
1460 }
1461 audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
1462 sig_data, sizeof(*sig_data) + len);
1463 kfree(sig_data);
1464 break;
1465 case AUDIT_TTY_GET: {
1466 struct audit_tty_status s;
1467 unsigned int t;
1468
1469 t = READ_ONCE(current->signal->audit_tty);
1470 s.enabled = t & AUDIT_TTY_ENABLE;
1471 s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
1472
1473 audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
1474 break;
1475 }
1476 case AUDIT_TTY_SET: {
1477 struct audit_tty_status s, old;
1478 struct audit_buffer *ab;
1479 unsigned int t;
1480
1481 memset(&s, 0, sizeof(s));
1482
1483 memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
1484
1485 if ((s.enabled != 0 && s.enabled != 1) ||
1486 (s.log_passwd != 0 && s.log_passwd != 1))
1487 err = -EINVAL;
1488
1489 if (err)
1490 t = READ_ONCE(current->signal->audit_tty);
1491 else {
1492 t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
1493 t = xchg(¤t->signal->audit_tty, t);
1494 }
1495 old.enabled = t & AUDIT_TTY_ENABLE;
1496 old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
1497
1498 audit_log_common_recv_msg(audit_context(), &ab,
1499 AUDIT_CONFIG_CHANGE);
1500 audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
1501 " old-log_passwd=%d new-log_passwd=%d res=%d",
1502 old.enabled, s.enabled, old.log_passwd,
1503 s.log_passwd, !err);
1504 audit_log_end(ab);
1505 break;
1506 }
1507 default:
1508 err = -EINVAL;
1509 break;
1510 }
1511
1512 return err < 0 ? err : 0;
1513}
1514
1515
1516
1517
1518
1519
1520
1521
1522static void audit_receive(struct sk_buff *skb)
1523{
1524 struct nlmsghdr *nlh;
1525
1526
1527
1528
1529 int len;
1530 int err;
1531
1532 nlh = nlmsg_hdr(skb);
1533 len = skb->len;
1534
1535 audit_ctl_lock();
1536 while (nlmsg_ok(nlh, len)) {
1537 err = audit_receive_msg(skb, nlh);
1538
1539 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
1540 netlink_ack(skb, nlh, err, NULL);
1541
1542 nlh = nlmsg_next(nlh, &len);
1543 }
1544 audit_ctl_unlock();
1545}
1546
1547
1548static void audit_log_multicast(int group, const char *op, int err)
1549{
1550 const struct cred *cred;
1551 struct tty_struct *tty;
1552 char comm[sizeof(current->comm)];
1553 struct audit_buffer *ab;
1554
1555 if (!audit_enabled)
1556 return;
1557
1558 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
1559 if (!ab)
1560 return;
1561
1562 cred = current_cred();
1563 tty = audit_get_tty();
1564 audit_log_format(ab, "pid=%u uid=%u auid=%u tty=%s ses=%u",
1565 task_pid_nr(current),
1566 from_kuid(&init_user_ns, cred->uid),
1567 from_kuid(&init_user_ns, audit_get_loginuid(current)),
1568 tty ? tty_name(tty) : "(none)",
1569 audit_get_sessionid(current));
1570 audit_put_tty(tty);
1571 audit_log_task_context(ab);
1572 audit_log_format(ab, " comm=");
1573 audit_log_untrustedstring(ab, get_task_comm(comm, current));
1574 audit_log_d_path_exe(ab, current->mm);
1575 audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
1576 audit_log_end(ab);
1577}
1578
1579
1580static int audit_multicast_bind(struct net *net, int group)
1581{
1582 int err = 0;
1583
1584 if (!capable(CAP_AUDIT_READ))
1585 err = -EPERM;
1586 audit_log_multicast(group, "connect", err);
1587 return err;
1588}
1589
1590static void audit_multicast_unbind(struct net *net, int group)
1591{
1592 audit_log_multicast(group, "disconnect", 0);
1593}
1594
1595static int __net_init audit_net_init(struct net *net)
1596{
1597 struct netlink_kernel_cfg cfg = {
1598 .input = audit_receive,
1599 .bind = audit_multicast_bind,
1600 .unbind = audit_multicast_unbind,
1601 .flags = NL_CFG_F_NONROOT_RECV,
1602 .groups = AUDIT_NLGRP_MAX,
1603 };
1604
1605 struct audit_net *aunet = net_generic(net, audit_net_id);
1606
1607 aunet->sk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
1608 if (aunet->sk == NULL) {
1609 audit_panic("cannot initialize netlink socket in namespace");
1610 return -ENOMEM;
1611 }
1612 aunet->sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
1613
1614 return 0;
1615}
1616
1617static void __net_exit audit_net_exit(struct net *net)
1618{
1619 struct audit_net *aunet = net_generic(net, audit_net_id);
1620
1621
1622
1623
1624
1625
1626
1627 netlink_kernel_release(aunet->sk);
1628}
1629
1630static struct pernet_operations audit_net_ops __net_initdata = {
1631 .init = audit_net_init,
1632 .exit = audit_net_exit,
1633 .id = &audit_net_id,
1634 .size = sizeof(struct audit_net),
1635};
1636
1637
1638static int __init audit_init(void)
1639{
1640 int i;
1641
1642 if (audit_initialized == AUDIT_DISABLED)
1643 return 0;
1644
1645 audit_buffer_cache = kmem_cache_create("audit_buffer",
1646 sizeof(struct audit_buffer),
1647 0, SLAB_PANIC, NULL);
1648
1649 skb_queue_head_init(&audit_queue);
1650 skb_queue_head_init(&audit_retry_queue);
1651 skb_queue_head_init(&audit_hold_queue);
1652
1653 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1654 INIT_LIST_HEAD(&audit_inode_hash[i]);
1655
1656 mutex_init(&audit_cmd_mutex.lock);
1657 audit_cmd_mutex.owner = NULL;
1658
1659 pr_info("initializing netlink subsys (%s)\n",
1660 audit_default ? "enabled" : "disabled");
1661 register_pernet_subsys(&audit_net_ops);
1662
1663 audit_initialized = AUDIT_INITIALIZED;
1664
1665 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
1666 if (IS_ERR(kauditd_task)) {
1667 int err = PTR_ERR(kauditd_task);
1668 panic("audit: failed to start the kauditd thread (%d)\n", err);
1669 }
1670
1671 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL,
1672 "state=initialized audit_enabled=%u res=1",
1673 audit_enabled);
1674
1675 return 0;
1676}
1677postcore_initcall(audit_init);
1678
1679
1680
1681
1682
1683static int __init audit_enable(char *str)
1684{
1685 if (!strcasecmp(str, "off") || !strcmp(str, "0"))
1686 audit_default = AUDIT_OFF;
1687 else if (!strcasecmp(str, "on") || !strcmp(str, "1"))
1688 audit_default = AUDIT_ON;
1689 else {
1690 pr_err("audit: invalid 'audit' parameter value (%s)\n", str);
1691 audit_default = AUDIT_ON;
1692 }
1693
1694 if (audit_default == AUDIT_OFF)
1695 audit_initialized = AUDIT_DISABLED;
1696 if (audit_set_enabled(audit_default))
1697 pr_err("audit: error setting audit state (%d)\n",
1698 audit_default);
1699
1700 pr_info("%s\n", audit_default ?
1701 "enabled (after initialization)" : "disabled (until reboot)");
1702
1703 return 1;
1704}
1705__setup("audit=", audit_enable);
1706
1707
1708
1709static int __init audit_backlog_limit_set(char *str)
1710{
1711 u32 audit_backlog_limit_arg;
1712
1713 pr_info("audit_backlog_limit: ");
1714 if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
1715 pr_cont("using default of %u, unable to parse %s\n",
1716 audit_backlog_limit, str);
1717 return 1;
1718 }
1719
1720 audit_backlog_limit = audit_backlog_limit_arg;
1721 pr_cont("%d\n", audit_backlog_limit);
1722
1723 return 1;
1724}
1725__setup("audit_backlog_limit=", audit_backlog_limit_set);
1726
1727static void audit_buffer_free(struct audit_buffer *ab)
1728{
1729 if (!ab)
1730 return;
1731
1732 kfree_skb(ab->skb);
1733 kmem_cache_free(audit_buffer_cache, ab);
1734}
1735
1736static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx,
1737 gfp_t gfp_mask, int type)
1738{
1739 struct audit_buffer *ab;
1740
1741 ab = kmem_cache_alloc(audit_buffer_cache, gfp_mask);
1742 if (!ab)
1743 return NULL;
1744
1745 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1746 if (!ab->skb)
1747 goto err;
1748 if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0))
1749 goto err;
1750
1751 ab->ctx = ctx;
1752 ab->gfp_mask = gfp_mask;
1753
1754 return ab;
1755
1756err:
1757 audit_buffer_free(ab);
1758 return NULL;
1759}
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778unsigned int audit_serial(void)
1779{
1780 static atomic_t serial = ATOMIC_INIT(0);
1781
1782 return atomic_inc_return(&serial);
1783}
1784
1785static inline void audit_get_stamp(struct audit_context *ctx,
1786 struct timespec64 *t, unsigned int *serial)
1787{
1788 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1789 ktime_get_coarse_real_ts64(t);
1790 *serial = audit_serial();
1791 }
1792}
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1810 int type)
1811{
1812 struct audit_buffer *ab;
1813 struct timespec64 t;
1814 unsigned int serial;
1815
1816 if (audit_initialized != AUDIT_INITIALIZED)
1817 return NULL;
1818
1819 if (unlikely(!audit_filter(type, AUDIT_FILTER_EXCLUDE)))
1820 return NULL;
1821
1822
1823
1824
1825
1826
1827
1828
1829 if (!(auditd_test_task(current) || audit_ctl_owner_current())) {
1830 long stime = audit_backlog_wait_time;
1831
1832 while (audit_backlog_limit &&
1833 (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
1834
1835 wake_up_interruptible(&kauditd_wait);
1836
1837
1838
1839 if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) {
1840 long rtime = stime;
1841
1842 DECLARE_WAITQUEUE(wait, current);
1843
1844 add_wait_queue_exclusive(&audit_backlog_wait,
1845 &wait);
1846 set_current_state(TASK_UNINTERRUPTIBLE);
1847 stime = schedule_timeout(rtime);
1848 atomic_add(rtime - stime, &audit_backlog_wait_time_actual);
1849 remove_wait_queue(&audit_backlog_wait, &wait);
1850 } else {
1851 if (audit_rate_check() && printk_ratelimit())
1852 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1853 skb_queue_len(&audit_queue),
1854 audit_backlog_limit);
1855 audit_log_lost("backlog limit exceeded");
1856 return NULL;
1857 }
1858 }
1859 }
1860
1861 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1862 if (!ab) {
1863 audit_log_lost("out of memory in audit_log_start");
1864 return NULL;
1865 }
1866
1867 audit_get_stamp(ab->ctx, &t, &serial);
1868
1869 if (ctx)
1870 ctx->dummy = 0;
1871 audit_log_format(ab, "audit(%llu.%03lu:%u): ",
1872 (unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial);
1873
1874 return ab;
1875}
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885static inline int audit_expand(struct audit_buffer *ab, int extra)
1886{
1887 struct sk_buff *skb = ab->skb;
1888 int oldtail = skb_tailroom(skb);
1889 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1890 int newtail = skb_tailroom(skb);
1891
1892 if (ret < 0) {
1893 audit_log_lost("out of memory in audit_expand");
1894 return 0;
1895 }
1896
1897 skb->truesize += newtail - oldtail;
1898 return newtail;
1899}
1900
1901
1902
1903
1904
1905
1906
1907static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1908 va_list args)
1909{
1910 int len, avail;
1911 struct sk_buff *skb;
1912 va_list args2;
1913
1914 if (!ab)
1915 return;
1916
1917 BUG_ON(!ab->skb);
1918 skb = ab->skb;
1919 avail = skb_tailroom(skb);
1920 if (avail == 0) {
1921 avail = audit_expand(ab, AUDIT_BUFSIZ);
1922 if (!avail)
1923 goto out;
1924 }
1925 va_copy(args2, args);
1926 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1927 if (len >= avail) {
1928
1929
1930
1931 avail = audit_expand(ab,
1932 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1933 if (!avail)
1934 goto out_va_end;
1935 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1936 }
1937 if (len > 0)
1938 skb_put(skb, len);
1939out_va_end:
1940 va_end(args2);
1941out:
1942 return;
1943}
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1954{
1955 va_list args;
1956
1957 if (!ab)
1958 return;
1959 va_start(args, fmt);
1960 audit_log_vformat(ab, fmt, args);
1961 va_end(args);
1962}
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1976 size_t len)
1977{
1978 int i, avail, new_len;
1979 unsigned char *ptr;
1980 struct sk_buff *skb;
1981
1982 if (!ab)
1983 return;
1984
1985 BUG_ON(!ab->skb);
1986 skb = ab->skb;
1987 avail = skb_tailroom(skb);
1988 new_len = len<<1;
1989 if (new_len >= avail) {
1990
1991 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1992 avail = audit_expand(ab, new_len);
1993 if (!avail)
1994 return;
1995 }
1996
1997 ptr = skb_tail_pointer(skb);
1998 for (i = 0; i < len; i++)
1999 ptr = hex_byte_pack_upper(ptr, buf[i]);
2000 *ptr = 0;
2001 skb_put(skb, len << 1);
2002}
2003
2004
2005
2006
2007
2008void audit_log_n_string(struct audit_buffer *ab, const char *string,
2009 size_t slen)
2010{
2011 int avail, new_len;
2012 unsigned char *ptr;
2013 struct sk_buff *skb;
2014
2015 if (!ab)
2016 return;
2017
2018 BUG_ON(!ab->skb);
2019 skb = ab->skb;
2020 avail = skb_tailroom(skb);
2021 new_len = slen + 3;
2022 if (new_len > avail) {
2023 avail = audit_expand(ab, new_len);
2024 if (!avail)
2025 return;
2026 }
2027 ptr = skb_tail_pointer(skb);
2028 *ptr++ = '"';
2029 memcpy(ptr, string, slen);
2030 ptr += slen;
2031 *ptr++ = '"';
2032 *ptr = 0;
2033 skb_put(skb, slen + 2);
2034}
2035
2036
2037
2038
2039
2040
2041bool audit_string_contains_control(const char *string, size_t len)
2042{
2043 const unsigned char *p;
2044 for (p = string; p < (const unsigned char *)string + len; p++) {
2045 if (*p == '"' || *p < 0x21 || *p > 0x7e)
2046 return true;
2047 }
2048 return false;
2049}
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
2066 size_t len)
2067{
2068 if (audit_string_contains_control(string, len))
2069 audit_log_n_hex(ab, string, len);
2070 else
2071 audit_log_n_string(ab, string, len);
2072}
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
2083{
2084 audit_log_n_untrustedstring(ab, string, strlen(string));
2085}
2086
2087
2088void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
2089 const struct path *path)
2090{
2091 char *p, *pathname;
2092
2093 if (prefix)
2094 audit_log_format(ab, "%s", prefix);
2095
2096
2097 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
2098 if (!pathname) {
2099 audit_log_format(ab, "\"<no_memory>\"");
2100 return;
2101 }
2102 p = d_path(path, pathname, PATH_MAX+11);
2103 if (IS_ERR(p)) {
2104
2105 audit_log_format(ab, "\"<too_long>\"");
2106 } else
2107 audit_log_untrustedstring(ab, p);
2108 kfree(pathname);
2109}
2110
2111void audit_log_session_info(struct audit_buffer *ab)
2112{
2113 unsigned int sessionid = audit_get_sessionid(current);
2114 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
2115
2116 audit_log_format(ab, "auid=%u ses=%u", auid, sessionid);
2117}
2118
2119void audit_log_key(struct audit_buffer *ab, char *key)
2120{
2121 audit_log_format(ab, " key=");
2122 if (key)
2123 audit_log_untrustedstring(ab, key);
2124 else
2125 audit_log_format(ab, "(null)");
2126}
2127
2128int audit_log_task_context(struct audit_buffer *ab)
2129{
2130 char *ctx = NULL;
2131 unsigned len;
2132 int error;
2133 u32 sid;
2134
2135 security_task_getsecid_subj(current, &sid);
2136 if (!sid)
2137 return 0;
2138
2139 error = security_secid_to_secctx(sid, &ctx, &len);
2140 if (error) {
2141 if (error != -EINVAL)
2142 goto error_path;
2143 return 0;
2144 }
2145
2146 audit_log_format(ab, " subj=%s", ctx);
2147 security_release_secctx(ctx, len);
2148 return 0;
2149
2150error_path:
2151 audit_panic("error in audit_log_task_context");
2152 return error;
2153}
2154EXPORT_SYMBOL(audit_log_task_context);
2155
2156void audit_log_d_path_exe(struct audit_buffer *ab,
2157 struct mm_struct *mm)
2158{
2159 struct file *exe_file;
2160
2161 if (!mm)
2162 goto out_null;
2163
2164 exe_file = get_mm_exe_file(mm);
2165 if (!exe_file)
2166 goto out_null;
2167
2168 audit_log_d_path(ab, " exe=", &exe_file->f_path);
2169 fput(exe_file);
2170 return;
2171out_null:
2172 audit_log_format(ab, " exe=(null)");
2173}
2174
2175struct tty_struct *audit_get_tty(void)
2176{
2177 struct tty_struct *tty = NULL;
2178 unsigned long flags;
2179
2180 spin_lock_irqsave(¤t->sighand->siglock, flags);
2181 if (current->signal)
2182 tty = tty_kref_get(current->signal->tty);
2183 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
2184 return tty;
2185}
2186
2187void audit_put_tty(struct tty_struct *tty)
2188{
2189 tty_kref_put(tty);
2190}
2191
2192void audit_log_task_info(struct audit_buffer *ab)
2193{
2194 const struct cred *cred;
2195 char comm[sizeof(current->comm)];
2196 struct tty_struct *tty;
2197
2198 if (!ab)
2199 return;
2200
2201 cred = current_cred();
2202 tty = audit_get_tty();
2203 audit_log_format(ab,
2204 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
2205 " euid=%u suid=%u fsuid=%u"
2206 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
2207 task_ppid_nr(current),
2208 task_tgid_nr(current),
2209 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2210 from_kuid(&init_user_ns, cred->uid),
2211 from_kgid(&init_user_ns, cred->gid),
2212 from_kuid(&init_user_ns, cred->euid),
2213 from_kuid(&init_user_ns, cred->suid),
2214 from_kuid(&init_user_ns, cred->fsuid),
2215 from_kgid(&init_user_ns, cred->egid),
2216 from_kgid(&init_user_ns, cred->sgid),
2217 from_kgid(&init_user_ns, cred->fsgid),
2218 tty ? tty_name(tty) : "(none)",
2219 audit_get_sessionid(current));
2220 audit_put_tty(tty);
2221 audit_log_format(ab, " comm=");
2222 audit_log_untrustedstring(ab, get_task_comm(comm, current));
2223 audit_log_d_path_exe(ab, current->mm);
2224 audit_log_task_context(ab);
2225}
2226EXPORT_SYMBOL(audit_log_task_info);
2227
2228
2229
2230
2231
2232
2233void audit_log_path_denied(int type, const char *operation)
2234{
2235 struct audit_buffer *ab;
2236
2237 if (!audit_enabled || audit_dummy_context())
2238 return;
2239
2240
2241 ab = audit_log_start(audit_context(), GFP_KERNEL, type);
2242 if (!ab)
2243 return;
2244 audit_log_format(ab, "op=%s", operation);
2245 audit_log_task_info(ab);
2246 audit_log_format(ab, " res=0");
2247 audit_log_end(ab);
2248}
2249
2250
2251static atomic_t session_id = ATOMIC_INIT(0);
2252
2253static int audit_set_loginuid_perm(kuid_t loginuid)
2254{
2255
2256 if (!audit_loginuid_set(current))
2257 return 0;
2258
2259 if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
2260 return -EPERM;
2261
2262 if (!capable(CAP_AUDIT_CONTROL))
2263 return -EPERM;
2264
2265 if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID)
2266 && uid_valid(loginuid))
2267 return -EPERM;
2268 return 0;
2269}
2270
2271static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
2272 unsigned int oldsessionid,
2273 unsigned int sessionid, int rc)
2274{
2275 struct audit_buffer *ab;
2276 uid_t uid, oldloginuid, loginuid;
2277 struct tty_struct *tty;
2278
2279 if (!audit_enabled)
2280 return;
2281
2282 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_LOGIN);
2283 if (!ab)
2284 return;
2285
2286 uid = from_kuid(&init_user_ns, task_uid(current));
2287 oldloginuid = from_kuid(&init_user_ns, koldloginuid);
2288 loginuid = from_kuid(&init_user_ns, kloginuid);
2289 tty = audit_get_tty();
2290
2291 audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
2292 audit_log_task_context(ab);
2293 audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
2294 oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
2295 oldsessionid, sessionid, !rc);
2296 audit_put_tty(tty);
2297 audit_log_end(ab);
2298}
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308int audit_set_loginuid(kuid_t loginuid)
2309{
2310 unsigned int oldsessionid, sessionid = AUDIT_SID_UNSET;
2311 kuid_t oldloginuid;
2312 int rc;
2313
2314 oldloginuid = audit_get_loginuid(current);
2315 oldsessionid = audit_get_sessionid(current);
2316
2317 rc = audit_set_loginuid_perm(loginuid);
2318 if (rc)
2319 goto out;
2320
2321
2322 if (uid_valid(loginuid)) {
2323 sessionid = (unsigned int)atomic_inc_return(&session_id);
2324 if (unlikely(sessionid == AUDIT_SID_UNSET))
2325 sessionid = (unsigned int)atomic_inc_return(&session_id);
2326 }
2327
2328 current->sessionid = sessionid;
2329 current->loginuid = loginuid;
2330out:
2331 audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
2332 return rc;
2333}
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343int audit_signal_info(int sig, struct task_struct *t)
2344{
2345 kuid_t uid = current_uid(), auid;
2346
2347 if (auditd_test_task(t) &&
2348 (sig == SIGTERM || sig == SIGHUP ||
2349 sig == SIGUSR1 || sig == SIGUSR2)) {
2350 audit_sig_pid = task_tgid_nr(current);
2351 auid = audit_get_loginuid(current);
2352 if (uid_valid(auid))
2353 audit_sig_uid = auid;
2354 else
2355 audit_sig_uid = uid;
2356 security_task_getsecid_subj(current, &audit_sig_sid);
2357 }
2358
2359 return audit_signal_info_syscall(t);
2360}
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371void audit_log_end(struct audit_buffer *ab)
2372{
2373 struct sk_buff *skb;
2374 struct nlmsghdr *nlh;
2375
2376 if (!ab)
2377 return;
2378
2379 if (audit_rate_check()) {
2380 skb = ab->skb;
2381 ab->skb = NULL;
2382
2383
2384
2385 nlh = nlmsg_hdr(skb);
2386 nlh->nlmsg_len = skb->len - NLMSG_HDRLEN;
2387
2388
2389 skb_queue_tail(&audit_queue, skb);
2390 wake_up_interruptible(&kauditd_wait);
2391 } else
2392 audit_log_lost("rate limit exceeded");
2393
2394 audit_buffer_free(ab);
2395}
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
2410 const char *fmt, ...)
2411{
2412 struct audit_buffer *ab;
2413 va_list args;
2414
2415 ab = audit_log_start(ctx, gfp_mask, type);
2416 if (ab) {
2417 va_start(args, fmt);
2418 audit_log_vformat(ab, fmt, args);
2419 va_end(args);
2420 audit_log_end(ab);
2421 }
2422}
2423
2424EXPORT_SYMBOL(audit_log_start);
2425EXPORT_SYMBOL(audit_log_end);
2426EXPORT_SYMBOL(audit_log_format);
2427EXPORT_SYMBOL(audit_log);
2428