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44#include <linux/init.h>
45#include <asm/types.h>
46#include <asm/atomic.h>
47#include <linux/mm.h>
48#include <linux/module.h>
49#include <linux/err.h>
50#include <linux/kthread.h>
51
52#include <linux/audit.h>
53
54#include <net/sock.h>
55#include <net/netlink.h>
56#include <linux/skbuff.h>
57#include <linux/netlink.h>
58#include <linux/inotify.h>
59#include <linux/freezer.h>
60#include <linux/tty.h>
61
62#include "audit.h"
63
64
65
66#define AUDIT_DISABLED -1
67#define AUDIT_UNINITIALIZED 0
68#define AUDIT_INITIALIZED 1
69static int audit_initialized;
70
71#define AUDIT_OFF 0
72#define AUDIT_ON 1
73#define AUDIT_LOCKED 2
74int audit_enabled;
75int audit_ever_enabled;
76
77
78static int audit_default;
79
80
81static int audit_failure = AUDIT_FAIL_PRINTK;
82
83
84
85
86
87
88int audit_pid;
89static int audit_nlk_pid;
90
91
92
93
94static int audit_rate_limit;
95
96
97static int audit_backlog_limit = 64;
98static int audit_backlog_wait_time = 60 * HZ;
99static int audit_backlog_wait_overflow = 0;
100
101
102uid_t audit_sig_uid = -1;
103pid_t audit_sig_pid = -1;
104u32 audit_sig_sid = 0;
105
106
107
108
109
110
111
112
113static atomic_t audit_lost = ATOMIC_INIT(0);
114
115
116static struct sock *audit_sock;
117
118
119struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
120
121
122
123
124static DEFINE_SPINLOCK(audit_freelist_lock);
125static int audit_freelist_count;
126static LIST_HEAD(audit_freelist);
127
128static struct sk_buff_head audit_skb_queue;
129
130static struct sk_buff_head audit_skb_hold_queue;
131static struct task_struct *kauditd_task;
132static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
133static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
134
135
136DEFINE_MUTEX(audit_cmd_mutex);
137
138
139
140
141#define AUDIT_BUFSIZ 1024
142
143
144
145#define AUDIT_MAXFREE (2*NR_CPUS)
146
147
148
149
150
151
152struct audit_buffer {
153 struct list_head list;
154 struct sk_buff *skb;
155 struct audit_context *ctx;
156 gfp_t gfp_mask;
157};
158
159struct audit_reply {
160 int pid;
161 struct sk_buff *skb;
162};
163
164static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
165{
166 if (ab) {
167 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
168 nlh->nlmsg_pid = pid;
169 }
170}
171
172void audit_panic(const char *message)
173{
174 switch (audit_failure)
175 {
176 case AUDIT_FAIL_SILENT:
177 break;
178 case AUDIT_FAIL_PRINTK:
179 if (printk_ratelimit())
180 printk(KERN_ERR "audit: %s\n", message);
181 break;
182 case AUDIT_FAIL_PANIC:
183
184 if (audit_pid)
185 panic("audit: %s\n", message);
186 break;
187 }
188}
189
190static inline int audit_rate_check(void)
191{
192 static unsigned long last_check = 0;
193 static int messages = 0;
194 static DEFINE_SPINLOCK(lock);
195 unsigned long flags;
196 unsigned long now;
197 unsigned long elapsed;
198 int retval = 0;
199
200 if (!audit_rate_limit) return 1;
201
202 spin_lock_irqsave(&lock, flags);
203 if (++messages < audit_rate_limit) {
204 retval = 1;
205 } else {
206 now = jiffies;
207 elapsed = now - last_check;
208 if (elapsed > HZ) {
209 last_check = now;
210 messages = 0;
211 retval = 1;
212 }
213 }
214 spin_unlock_irqrestore(&lock, flags);
215
216 return retval;
217}
218
219
220
221
222
223
224
225
226
227void audit_log_lost(const char *message)
228{
229 static unsigned long last_msg = 0;
230 static DEFINE_SPINLOCK(lock);
231 unsigned long flags;
232 unsigned long now;
233 int print;
234
235 atomic_inc(&audit_lost);
236
237 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
238
239 if (!print) {
240 spin_lock_irqsave(&lock, flags);
241 now = jiffies;
242 if (now - last_msg > HZ) {
243 print = 1;
244 last_msg = now;
245 }
246 spin_unlock_irqrestore(&lock, flags);
247 }
248
249 if (print) {
250 if (printk_ratelimit())
251 printk(KERN_WARNING
252 "audit: audit_lost=%d audit_rate_limit=%d "
253 "audit_backlog_limit=%d\n",
254 atomic_read(&audit_lost),
255 audit_rate_limit,
256 audit_backlog_limit);
257 audit_panic(message);
258 }
259}
260
261static int audit_log_config_change(char *function_name, int new, int old,
262 uid_t loginuid, u32 sessionid, u32 sid,
263 int allow_changes)
264{
265 struct audit_buffer *ab;
266 int rc = 0;
267
268 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
269 audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
270 old, loginuid, sessionid);
271 if (sid) {
272 char *ctx = NULL;
273 u32 len;
274
275 rc = security_secid_to_secctx(sid, &ctx, &len);
276 if (rc) {
277 audit_log_format(ab, " sid=%u", sid);
278 allow_changes = 0;
279 } else {
280 audit_log_format(ab, " subj=%s", ctx);
281 security_release_secctx(ctx, len);
282 }
283 }
284 audit_log_format(ab, " res=%d", allow_changes);
285 audit_log_end(ab);
286 return rc;
287}
288
289static int audit_do_config_change(char *function_name, int *to_change,
290 int new, uid_t loginuid, u32 sessionid,
291 u32 sid)
292{
293 int allow_changes, rc = 0, old = *to_change;
294
295
296 if (audit_enabled == AUDIT_LOCKED)
297 allow_changes = 0;
298 else
299 allow_changes = 1;
300
301 if (audit_enabled != AUDIT_OFF) {
302 rc = audit_log_config_change(function_name, new, old, loginuid,
303 sessionid, sid, allow_changes);
304 if (rc)
305 allow_changes = 0;
306 }
307
308
309 if (allow_changes == 1)
310 *to_change = new;
311
312 else if (rc == 0)
313 rc = -EPERM;
314 return rc;
315}
316
317static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid,
318 u32 sid)
319{
320 return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
321 limit, loginuid, sessionid, sid);
322}
323
324static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid,
325 u32 sid)
326{
327 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
328 limit, loginuid, sessionid, sid);
329}
330
331static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid)
332{
333 int rc;
334 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
335 return -EINVAL;
336
337 rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
338 loginuid, sessionid, sid);
339
340 if (!rc)
341 audit_ever_enabled |= !!state;
342
343 return rc;
344}
345
346static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid)
347{
348 if (state != AUDIT_FAIL_SILENT
349 && state != AUDIT_FAIL_PRINTK
350 && state != AUDIT_FAIL_PANIC)
351 return -EINVAL;
352
353 return audit_do_config_change("audit_failure", &audit_failure, state,
354 loginuid, sessionid, sid);
355}
356
357
358
359
360
361
362
363
364
365
366static void audit_hold_skb(struct sk_buff *skb)
367{
368 if (audit_default &&
369 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
370 skb_queue_tail(&audit_skb_hold_queue, skb);
371 else
372 kfree_skb(skb);
373}
374
375
376
377
378
379static void audit_printk_skb(struct sk_buff *skb)
380{
381 struct nlmsghdr *nlh = nlmsg_hdr(skb);
382 char *data = NLMSG_DATA(nlh);
383
384 if (nlh->nlmsg_type != AUDIT_EOE) {
385 if (printk_ratelimit())
386 printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data);
387 else
388 audit_log_lost("printk limit exceeded\n");
389 }
390
391 audit_hold_skb(skb);
392}
393
394static void kauditd_send_skb(struct sk_buff *skb)
395{
396 int err;
397
398 skb_get(skb);
399 err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0);
400 if (err < 0) {
401 BUG_ON(err != -ECONNREFUSED);
402 printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
403 audit_log_lost("auditd dissapeared\n");
404 audit_pid = 0;
405
406 audit_hold_skb(skb);
407 } else
408
409 kfree_skb(skb);
410}
411
412static int kauditd_thread(void *dummy)
413{
414 struct sk_buff *skb;
415
416 set_freezable();
417 while (!kthread_should_stop()) {
418
419
420
421
422
423
424
425
426
427
428
429
430
431 if (audit_default && audit_pid) {
432 skb = skb_dequeue(&audit_skb_hold_queue);
433 if (unlikely(skb)) {
434 while (skb && audit_pid) {
435 kauditd_send_skb(skb);
436 skb = skb_dequeue(&audit_skb_hold_queue);
437 }
438 }
439 }
440
441 skb = skb_dequeue(&audit_skb_queue);
442 wake_up(&audit_backlog_wait);
443 if (skb) {
444 if (audit_pid)
445 kauditd_send_skb(skb);
446 else
447 audit_printk_skb(skb);
448 } else {
449 DECLARE_WAITQUEUE(wait, current);
450 set_current_state(TASK_INTERRUPTIBLE);
451 add_wait_queue(&kauditd_wait, &wait);
452
453 if (!skb_queue_len(&audit_skb_queue)) {
454 try_to_freeze();
455 schedule();
456 }
457
458 __set_current_state(TASK_RUNNING);
459 remove_wait_queue(&kauditd_wait, &wait);
460 }
461 }
462 return 0;
463}
464
465static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid)
466{
467 struct task_struct *tsk;
468 int err;
469
470 read_lock(&tasklist_lock);
471 tsk = find_task_by_vpid(pid);
472 err = -ESRCH;
473 if (!tsk)
474 goto out;
475 err = 0;
476
477 spin_lock_irq(&tsk->sighand->siglock);
478 if (!tsk->signal->audit_tty)
479 err = -EPERM;
480 spin_unlock_irq(&tsk->sighand->siglock);
481 if (err)
482 goto out;
483
484 tty_audit_push_task(tsk, loginuid, sessionid);
485out:
486 read_unlock(&tasklist_lock);
487 return err;
488}
489
490int audit_send_list(void *_dest)
491{
492 struct audit_netlink_list *dest = _dest;
493 int pid = dest->pid;
494 struct sk_buff *skb;
495
496
497 mutex_lock(&audit_cmd_mutex);
498 mutex_unlock(&audit_cmd_mutex);
499
500 while ((skb = __skb_dequeue(&dest->q)) != NULL)
501 netlink_unicast(audit_sock, skb, pid, 0);
502
503 kfree(dest);
504
505 return 0;
506}
507
508struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
509 int multi, void *payload, int size)
510{
511 struct sk_buff *skb;
512 struct nlmsghdr *nlh;
513 void *data;
514 int flags = multi ? NLM_F_MULTI : 0;
515 int t = done ? NLMSG_DONE : type;
516
517 skb = nlmsg_new(size, GFP_KERNEL);
518 if (!skb)
519 return NULL;
520
521 nlh = NLMSG_NEW(skb, pid, seq, t, size, flags);
522 data = NLMSG_DATA(nlh);
523 memcpy(data, payload, size);
524 return skb;
525
526nlmsg_failure:
527 if (skb)
528 kfree_skb(skb);
529 return NULL;
530}
531
532static int audit_send_reply_thread(void *arg)
533{
534 struct audit_reply *reply = (struct audit_reply *)arg;
535
536 mutex_lock(&audit_cmd_mutex);
537 mutex_unlock(&audit_cmd_mutex);
538
539
540
541 netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
542 kfree(reply);
543 return 0;
544}
545
546
547
548
549
550
551
552
553
554
555
556
557
558void audit_send_reply(int pid, int seq, int type, int done, int multi,
559 void *payload, int size)
560{
561 struct sk_buff *skb;
562 struct task_struct *tsk;
563 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
564 GFP_KERNEL);
565
566 if (!reply)
567 return;
568
569 skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
570 if (!skb)
571 goto out;
572
573 reply->pid = pid;
574 reply->skb = skb;
575
576 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
577 if (!IS_ERR(tsk))
578 return;
579 kfree_skb(skb);
580out:
581 kfree(reply);
582}
583
584
585
586
587
588static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
589{
590 int err = 0;
591
592 switch (msg_type) {
593 case AUDIT_GET:
594 case AUDIT_LIST:
595 case AUDIT_LIST_RULES:
596 case AUDIT_SET:
597 case AUDIT_ADD:
598 case AUDIT_ADD_RULE:
599 case AUDIT_DEL:
600 case AUDIT_DEL_RULE:
601 case AUDIT_SIGNAL_INFO:
602 case AUDIT_TTY_GET:
603 case AUDIT_TTY_SET:
604 case AUDIT_TRIM:
605 case AUDIT_MAKE_EQUIV:
606 if (security_netlink_recv(skb, CAP_AUDIT_CONTROL))
607 err = -EPERM;
608 break;
609 case AUDIT_USER:
610 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
611 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
612 if (security_netlink_recv(skb, CAP_AUDIT_WRITE))
613 err = -EPERM;
614 break;
615 default:
616 err = -EINVAL;
617 }
618
619 return err;
620}
621
622static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
623 u32 pid, u32 uid, uid_t auid, u32 ses,
624 u32 sid)
625{
626 int rc = 0;
627 char *ctx = NULL;
628 u32 len;
629
630 if (!audit_enabled) {
631 *ab = NULL;
632 return rc;
633 }
634
635 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
636 audit_log_format(*ab, "user pid=%d uid=%u auid=%u ses=%u",
637 pid, uid, auid, ses);
638 if (sid) {
639 rc = security_secid_to_secctx(sid, &ctx, &len);
640 if (rc)
641 audit_log_format(*ab, " ssid=%u", sid);
642 else {
643 audit_log_format(*ab, " subj=%s", ctx);
644 security_release_secctx(ctx, len);
645 }
646 }
647
648 return rc;
649}
650
651static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
652{
653 u32 uid, pid, seq, sid;
654 void *data;
655 struct audit_status *status_get, status_set;
656 int err;
657 struct audit_buffer *ab;
658 u16 msg_type = nlh->nlmsg_type;
659 uid_t loginuid;
660 u32 sessionid;
661 struct audit_sig_info *sig_data;
662 char *ctx = NULL;
663 u32 len;
664
665 err = audit_netlink_ok(skb, msg_type);
666 if (err)
667 return err;
668
669
670
671 if (!kauditd_task)
672 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
673 if (IS_ERR(kauditd_task)) {
674 err = PTR_ERR(kauditd_task);
675 kauditd_task = NULL;
676 return err;
677 }
678
679 pid = NETLINK_CREDS(skb)->pid;
680 uid = NETLINK_CREDS(skb)->uid;
681 loginuid = NETLINK_CB(skb).loginuid;
682 sessionid = NETLINK_CB(skb).sessionid;
683 sid = NETLINK_CB(skb).sid;
684 seq = nlh->nlmsg_seq;
685 data = NLMSG_DATA(nlh);
686
687 switch (msg_type) {
688 case AUDIT_GET:
689 status_set.enabled = audit_enabled;
690 status_set.failure = audit_failure;
691 status_set.pid = audit_pid;
692 status_set.rate_limit = audit_rate_limit;
693 status_set.backlog_limit = audit_backlog_limit;
694 status_set.lost = atomic_read(&audit_lost);
695 status_set.backlog = skb_queue_len(&audit_skb_queue);
696 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0,
697 &status_set, sizeof(status_set));
698 break;
699 case AUDIT_SET:
700 if (nlh->nlmsg_len < sizeof(struct audit_status))
701 return -EINVAL;
702 status_get = (struct audit_status *)data;
703 if (status_get->mask & AUDIT_STATUS_ENABLED) {
704 err = audit_set_enabled(status_get->enabled,
705 loginuid, sessionid, sid);
706 if (err < 0)
707 return err;
708 }
709 if (status_get->mask & AUDIT_STATUS_FAILURE) {
710 err = audit_set_failure(status_get->failure,
711 loginuid, sessionid, sid);
712 if (err < 0)
713 return err;
714 }
715 if (status_get->mask & AUDIT_STATUS_PID) {
716 int new_pid = status_get->pid;
717
718 if (audit_enabled != AUDIT_OFF)
719 audit_log_config_change("audit_pid", new_pid,
720 audit_pid, loginuid,
721 sessionid, sid, 1);
722
723 audit_pid = new_pid;
724 audit_nlk_pid = NETLINK_CB(skb).pid;
725 }
726 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
727 err = audit_set_rate_limit(status_get->rate_limit,
728 loginuid, sessionid, sid);
729 if (err < 0)
730 return err;
731 }
732 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
733 err = audit_set_backlog_limit(status_get->backlog_limit,
734 loginuid, sessionid, sid);
735 break;
736 case AUDIT_USER:
737 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
738 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
739 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
740 return 0;
741
742 err = audit_filter_user(&NETLINK_CB(skb));
743 if (err == 1) {
744 err = 0;
745 if (msg_type == AUDIT_USER_TTY) {
746 err = audit_prepare_user_tty(pid, loginuid,
747 sessionid);
748 if (err)
749 break;
750 }
751 audit_log_common_recv_msg(&ab, msg_type, pid, uid,
752 loginuid, sessionid, sid);
753
754 if (msg_type != AUDIT_USER_TTY)
755 audit_log_format(ab, " msg='%.1024s'",
756 (char *)data);
757 else {
758 int size;
759
760 audit_log_format(ab, " msg=");
761 size = nlmsg_len(nlh);
762 if (size > 0 &&
763 ((unsigned char *)data)[size - 1] == '\0')
764 size--;
765 audit_log_n_untrustedstring(ab, data, size);
766 }
767 audit_set_pid(ab, pid);
768 audit_log_end(ab);
769 }
770 break;
771 case AUDIT_ADD:
772 case AUDIT_DEL:
773 if (nlmsg_len(nlh) < sizeof(struct audit_rule))
774 return -EINVAL;
775 if (audit_enabled == AUDIT_LOCKED) {
776 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
777 uid, loginuid, sessionid, sid);
778
779 audit_log_format(ab, " audit_enabled=%d res=0",
780 audit_enabled);
781 audit_log_end(ab);
782 return -EPERM;
783 }
784
785 case AUDIT_LIST:
786 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
787 uid, seq, data, nlmsg_len(nlh),
788 loginuid, sessionid, sid);
789 break;
790 case AUDIT_ADD_RULE:
791 case AUDIT_DEL_RULE:
792 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
793 return -EINVAL;
794 if (audit_enabled == AUDIT_LOCKED) {
795 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
796 uid, loginuid, sessionid, sid);
797
798 audit_log_format(ab, " audit_enabled=%d res=0",
799 audit_enabled);
800 audit_log_end(ab);
801 return -EPERM;
802 }
803
804 case AUDIT_LIST_RULES:
805 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
806 uid, seq, data, nlmsg_len(nlh),
807 loginuid, sessionid, sid);
808 break;
809 case AUDIT_TRIM:
810 audit_trim_trees();
811
812 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
813 uid, loginuid, sessionid, sid);
814
815 audit_log_format(ab, " op=trim res=1");
816 audit_log_end(ab);
817 break;
818 case AUDIT_MAKE_EQUIV: {
819 void *bufp = data;
820 u32 sizes[2];
821 size_t msglen = nlmsg_len(nlh);
822 char *old, *new;
823
824 err = -EINVAL;
825 if (msglen < 2 * sizeof(u32))
826 break;
827 memcpy(sizes, bufp, 2 * sizeof(u32));
828 bufp += 2 * sizeof(u32);
829 msglen -= 2 * sizeof(u32);
830 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
831 if (IS_ERR(old)) {
832 err = PTR_ERR(old);
833 break;
834 }
835 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
836 if (IS_ERR(new)) {
837 err = PTR_ERR(new);
838 kfree(old);
839 break;
840 }
841
842 err = audit_tag_tree(old, new);
843
844 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
845 uid, loginuid, sessionid, sid);
846
847 audit_log_format(ab, " op=make_equiv old=");
848 audit_log_untrustedstring(ab, old);
849 audit_log_format(ab, " new=");
850 audit_log_untrustedstring(ab, new);
851 audit_log_format(ab, " res=%d", !err);
852 audit_log_end(ab);
853 kfree(old);
854 kfree(new);
855 break;
856 }
857 case AUDIT_SIGNAL_INFO:
858 len = 0;
859 if (audit_sig_sid) {
860 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
861 if (err)
862 return err;
863 }
864 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
865 if (!sig_data) {
866 if (audit_sig_sid)
867 security_release_secctx(ctx, len);
868 return -ENOMEM;
869 }
870 sig_data->uid = audit_sig_uid;
871 sig_data->pid = audit_sig_pid;
872 if (audit_sig_sid) {
873 memcpy(sig_data->ctx, ctx, len);
874 security_release_secctx(ctx, len);
875 }
876 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
877 0, 0, sig_data, sizeof(*sig_data) + len);
878 kfree(sig_data);
879 break;
880 case AUDIT_TTY_GET: {
881 struct audit_tty_status s;
882 struct task_struct *tsk;
883
884 read_lock(&tasklist_lock);
885 tsk = find_task_by_vpid(pid);
886 if (!tsk)
887 err = -ESRCH;
888 else {
889 spin_lock_irq(&tsk->sighand->siglock);
890 s.enabled = tsk->signal->audit_tty != 0;
891 spin_unlock_irq(&tsk->sighand->siglock);
892 }
893 read_unlock(&tasklist_lock);
894 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_TTY_GET, 0, 0,
895 &s, sizeof(s));
896 break;
897 }
898 case AUDIT_TTY_SET: {
899 struct audit_tty_status *s;
900 struct task_struct *tsk;
901
902 if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
903 return -EINVAL;
904 s = data;
905 if (s->enabled != 0 && s->enabled != 1)
906 return -EINVAL;
907 read_lock(&tasklist_lock);
908 tsk = find_task_by_vpid(pid);
909 if (!tsk)
910 err = -ESRCH;
911 else {
912 spin_lock_irq(&tsk->sighand->siglock);
913 tsk->signal->audit_tty = s->enabled != 0;
914 spin_unlock_irq(&tsk->sighand->siglock);
915 }
916 read_unlock(&tasklist_lock);
917 break;
918 }
919 default:
920 err = -EINVAL;
921 break;
922 }
923
924 return err < 0 ? err : 0;
925}
926
927
928
929
930
931static void audit_receive_skb(struct sk_buff *skb)
932{
933 struct nlmsghdr *nlh;
934
935
936
937
938 int len;
939 int err;
940
941 nlh = nlmsg_hdr(skb);
942 len = skb->len;
943
944 while (NLMSG_OK(nlh, len)) {
945 err = audit_receive_msg(skb, nlh);
946
947 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
948 netlink_ack(skb, nlh, err);
949
950 nlh = NLMSG_NEXT(nlh, len);
951 }
952}
953
954
955static void audit_receive(struct sk_buff *skb)
956{
957 mutex_lock(&audit_cmd_mutex);
958 audit_receive_skb(skb);
959 mutex_unlock(&audit_cmd_mutex);
960}
961
962
963static int __init audit_init(void)
964{
965 int i;
966
967 if (audit_initialized == AUDIT_DISABLED)
968 return 0;
969
970 printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
971 audit_default ? "enabled" : "disabled");
972 audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, 0,
973 audit_receive, NULL, THIS_MODULE);
974 if (!audit_sock)
975 audit_panic("cannot initialize netlink socket");
976 else
977 audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
978
979 skb_queue_head_init(&audit_skb_queue);
980 skb_queue_head_init(&audit_skb_hold_queue);
981 audit_initialized = AUDIT_INITIALIZED;
982 audit_enabled = audit_default;
983 audit_ever_enabled |= !!audit_default;
984
985 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
986
987 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
988 INIT_LIST_HEAD(&audit_inode_hash[i]);
989
990 return 0;
991}
992__initcall(audit_init);
993
994
995static int __init audit_enable(char *str)
996{
997 audit_default = !!simple_strtol(str, NULL, 0);
998 if (!audit_default)
999 audit_initialized = AUDIT_DISABLED;
1000
1001 printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
1002
1003 if (audit_initialized == AUDIT_INITIALIZED) {
1004 audit_enabled = audit_default;
1005 audit_ever_enabled |= !!audit_default;
1006 } else if (audit_initialized == AUDIT_UNINITIALIZED) {
1007 printk(" (after initialization)");
1008 } else {
1009 printk(" (until reboot)");
1010 }
1011 printk("\n");
1012
1013 return 1;
1014}
1015
1016__setup("audit=", audit_enable);
1017
1018static void audit_buffer_free(struct audit_buffer *ab)
1019{
1020 unsigned long flags;
1021
1022 if (!ab)
1023 return;
1024
1025 if (ab->skb)
1026 kfree_skb(ab->skb);
1027
1028 spin_lock_irqsave(&audit_freelist_lock, flags);
1029 if (audit_freelist_count > AUDIT_MAXFREE)
1030 kfree(ab);
1031 else {
1032 audit_freelist_count++;
1033 list_add(&ab->list, &audit_freelist);
1034 }
1035 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1036}
1037
1038static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
1039 gfp_t gfp_mask, int type)
1040{
1041 unsigned long flags;
1042 struct audit_buffer *ab = NULL;
1043 struct nlmsghdr *nlh;
1044
1045 spin_lock_irqsave(&audit_freelist_lock, flags);
1046 if (!list_empty(&audit_freelist)) {
1047 ab = list_entry(audit_freelist.next,
1048 struct audit_buffer, list);
1049 list_del(&ab->list);
1050 --audit_freelist_count;
1051 }
1052 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1053
1054 if (!ab) {
1055 ab = kmalloc(sizeof(*ab), gfp_mask);
1056 if (!ab)
1057 goto err;
1058 }
1059
1060 ab->ctx = ctx;
1061 ab->gfp_mask = gfp_mask;
1062
1063 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1064 if (!ab->skb)
1065 goto nlmsg_failure;
1066
1067 nlh = NLMSG_NEW(ab->skb, 0, 0, type, 0, 0);
1068
1069 return ab;
1070
1071nlmsg_failure:
1072 kfree_skb(ab->skb);
1073 ab->skb = NULL;
1074err:
1075 audit_buffer_free(ab);
1076 return NULL;
1077}
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096unsigned int audit_serial(void)
1097{
1098 static DEFINE_SPINLOCK(serial_lock);
1099 static unsigned int serial = 0;
1100
1101 unsigned long flags;
1102 unsigned int ret;
1103
1104 spin_lock_irqsave(&serial_lock, flags);
1105 do {
1106 ret = ++serial;
1107 } while (unlikely(!ret));
1108 spin_unlock_irqrestore(&serial_lock, flags);
1109
1110 return ret;
1111}
1112
1113static inline void audit_get_stamp(struct audit_context *ctx,
1114 struct timespec *t, unsigned int *serial)
1115{
1116 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1117 *t = CURRENT_TIME;
1118 *serial = audit_serial();
1119 }
1120}
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1145 int type)
1146{
1147 struct audit_buffer *ab = NULL;
1148 struct timespec t;
1149 unsigned int uninitialized_var(serial);
1150 int reserve;
1151 unsigned long timeout_start = jiffies;
1152
1153 if (audit_initialized != AUDIT_INITIALIZED)
1154 return NULL;
1155
1156 if (unlikely(audit_filter_type(type)))
1157 return NULL;
1158
1159 if (gfp_mask & __GFP_WAIT)
1160 reserve = 0;
1161 else
1162 reserve = 5;
1163
1164
1165 while (audit_backlog_limit
1166 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
1167 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time
1168 && time_before(jiffies, timeout_start + audit_backlog_wait_time)) {
1169
1170
1171 DECLARE_WAITQUEUE(wait, current);
1172 set_current_state(TASK_INTERRUPTIBLE);
1173 add_wait_queue(&audit_backlog_wait, &wait);
1174
1175 if (audit_backlog_limit &&
1176 skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
1177 schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies);
1178
1179 __set_current_state(TASK_RUNNING);
1180 remove_wait_queue(&audit_backlog_wait, &wait);
1181 continue;
1182 }
1183 if (audit_rate_check() && printk_ratelimit())
1184 printk(KERN_WARNING
1185 "audit: audit_backlog=%d > "
1186 "audit_backlog_limit=%d\n",
1187 skb_queue_len(&audit_skb_queue),
1188 audit_backlog_limit);
1189 audit_log_lost("backlog limit exceeded");
1190 audit_backlog_wait_time = audit_backlog_wait_overflow;
1191 wake_up(&audit_backlog_wait);
1192 return NULL;
1193 }
1194
1195 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1196 if (!ab) {
1197 audit_log_lost("out of memory in audit_log_start");
1198 return NULL;
1199 }
1200
1201 audit_get_stamp(ab->ctx, &t, &serial);
1202
1203 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1204 t.tv_sec, t.tv_nsec/1000000, serial);
1205 return ab;
1206}
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216static inline int audit_expand(struct audit_buffer *ab, int extra)
1217{
1218 struct sk_buff *skb = ab->skb;
1219 int oldtail = skb_tailroom(skb);
1220 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1221 int newtail = skb_tailroom(skb);
1222
1223 if (ret < 0) {
1224 audit_log_lost("out of memory in audit_expand");
1225 return 0;
1226 }
1227
1228 skb->truesize += newtail - oldtail;
1229 return newtail;
1230}
1231
1232
1233
1234
1235
1236
1237
1238static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1239 va_list args)
1240{
1241 int len, avail;
1242 struct sk_buff *skb;
1243 va_list args2;
1244
1245 if (!ab)
1246 return;
1247
1248 BUG_ON(!ab->skb);
1249 skb = ab->skb;
1250 avail = skb_tailroom(skb);
1251 if (avail == 0) {
1252 avail = audit_expand(ab, AUDIT_BUFSIZ);
1253 if (!avail)
1254 goto out;
1255 }
1256 va_copy(args2, args);
1257 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1258 if (len >= avail) {
1259
1260
1261
1262 avail = audit_expand(ab,
1263 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1264 if (!avail)
1265 goto out;
1266 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1267 }
1268 va_end(args2);
1269 if (len > 0)
1270 skb_put(skb, len);
1271out:
1272 return;
1273}
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1284{
1285 va_list args;
1286
1287 if (!ab)
1288 return;
1289 va_start(args, fmt);
1290 audit_log_vformat(ab, fmt, args);
1291 va_end(args);
1292}
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1306 size_t len)
1307{
1308 int i, avail, new_len;
1309 unsigned char *ptr;
1310 struct sk_buff *skb;
1311 static const unsigned char *hex = "0123456789ABCDEF";
1312
1313 if (!ab)
1314 return;
1315
1316 BUG_ON(!ab->skb);
1317 skb = ab->skb;
1318 avail = skb_tailroom(skb);
1319 new_len = len<<1;
1320 if (new_len >= avail) {
1321
1322 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1323 avail = audit_expand(ab, new_len);
1324 if (!avail)
1325 return;
1326 }
1327
1328 ptr = skb_tail_pointer(skb);
1329 for (i=0; i<len; i++) {
1330 *ptr++ = hex[(buf[i] & 0xF0)>>4];
1331 *ptr++ = hex[buf[i] & 0x0F];
1332 }
1333 *ptr = 0;
1334 skb_put(skb, len << 1);
1335}
1336
1337
1338
1339
1340
1341void audit_log_n_string(struct audit_buffer *ab, const char *string,
1342 size_t slen)
1343{
1344 int avail, new_len;
1345 unsigned char *ptr;
1346 struct sk_buff *skb;
1347
1348 if (!ab)
1349 return;
1350
1351 BUG_ON(!ab->skb);
1352 skb = ab->skb;
1353 avail = skb_tailroom(skb);
1354 new_len = slen + 3;
1355 if (new_len > avail) {
1356 avail = audit_expand(ab, new_len);
1357 if (!avail)
1358 return;
1359 }
1360 ptr = skb_tail_pointer(skb);
1361 *ptr++ = '"';
1362 memcpy(ptr, string, slen);
1363 ptr += slen;
1364 *ptr++ = '"';
1365 *ptr = 0;
1366 skb_put(skb, slen + 2);
1367}
1368
1369
1370
1371
1372
1373
1374int audit_string_contains_control(const char *string, size_t len)
1375{
1376 const unsigned char *p;
1377 for (p = string; p < (const unsigned char *)string + len; p++) {
1378 if (*p == '"' || *p < 0x21 || *p > 0x7e)
1379 return 1;
1380 }
1381 return 0;
1382}
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1399 size_t len)
1400{
1401 if (audit_string_contains_control(string, len))
1402 audit_log_n_hex(ab, string, len);
1403 else
1404 audit_log_n_string(ab, string, len);
1405}
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
1416{
1417 audit_log_n_untrustedstring(ab, string, strlen(string));
1418}
1419
1420
1421void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
1422 struct path *path)
1423{
1424 char *p, *pathname;
1425
1426 if (prefix)
1427 audit_log_format(ab, " %s", prefix);
1428
1429
1430 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1431 if (!pathname) {
1432 audit_log_string(ab, "<no_memory>");
1433 return;
1434 }
1435 p = d_path(path, pathname, PATH_MAX+11);
1436 if (IS_ERR(p)) {
1437
1438 audit_log_string(ab, "<too_long>");
1439 } else
1440 audit_log_untrustedstring(ab, p);
1441 kfree(pathname);
1442}
1443
1444void audit_log_key(struct audit_buffer *ab, char *key)
1445{
1446 audit_log_format(ab, " key=");
1447 if (key)
1448 audit_log_untrustedstring(ab, key);
1449 else
1450 audit_log_format(ab, "(null)");
1451}
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462void audit_log_end(struct audit_buffer *ab)
1463{
1464 if (!ab)
1465 return;
1466 if (!audit_rate_check()) {
1467 audit_log_lost("rate limit exceeded");
1468 } else {
1469 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
1470 nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
1471
1472 if (audit_pid) {
1473 skb_queue_tail(&audit_skb_queue, ab->skb);
1474 wake_up_interruptible(&kauditd_wait);
1475 } else {
1476 audit_printk_skb(ab->skb);
1477 }
1478 ab->skb = NULL;
1479 }
1480 audit_buffer_free(ab);
1481}
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
1496 const char *fmt, ...)
1497{
1498 struct audit_buffer *ab;
1499 va_list args;
1500
1501 ab = audit_log_start(ctx, gfp_mask, type);
1502 if (ab) {
1503 va_start(args, fmt);
1504 audit_log_vformat(ab, fmt, args);
1505 va_end(args);
1506 audit_log_end(ab);
1507 }
1508}
1509
1510EXPORT_SYMBOL(audit_log_start);
1511EXPORT_SYMBOL(audit_log_end);
1512EXPORT_SYMBOL(audit_log_format);
1513EXPORT_SYMBOL(audit_log);
1514