Line data Source code
1 : /* audit.c -- Auditing support
2 : * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
3 : * System-call specific features have moved to auditsc.c
4 : *
5 : * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
6 : * All Rights Reserved.
7 : *
8 : * This program is free software; you can redistribute it and/or modify
9 : * it under the terms of the GNU General Public License as published by
10 : * the Free Software Foundation; either version 2 of the License, or
11 : * (at your option) any later version.
12 : *
13 : * This program is distributed in the hope that it will be useful,
14 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 : * GNU General Public License for more details.
17 : *
18 : * You should have received a copy of the GNU General Public License
19 : * along with this program; if not, write to the Free Software
20 : * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 : *
22 : * Written by Rickard E. (Rik) Faith <faith@redhat.com>
23 : *
24 : * Goals: 1) Integrate fully with Security Modules.
25 : * 2) Minimal run-time overhead:
26 : * a) Minimal when syscall auditing is disabled (audit_enable=0).
27 : * b) Small when syscall auditing is enabled and no audit record
28 : * is generated (defer as much work as possible to record
29 : * generation time):
30 : * i) context is allocated,
31 : * ii) names from getname are stored without a copy, and
32 : * iii) inode information stored from path_lookup.
33 : * 3) Ability to disable syscall auditing at boot time (audit=0).
34 : * 4) Usable by other parts of the kernel (if audit_log* is called,
35 : * then a syscall record will be generated automatically for the
36 : * current syscall).
37 : * 5) Netlink interface to user-space.
38 : * 6) Support low-overhead kernel-based filtering to minimize the
39 : * information that must be passed to user-space.
40 : *
41 : * Example user-space utilities: http://people.redhat.com/sgrubb/audit/
42 : */
43 :
44 : #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
45 :
46 : #include <linux/init.h>
47 : #include <linux/types.h>
48 : #include <linux/atomic.h>
49 : #include <linux/mm.h>
50 : #include <linux/export.h>
51 : #include <linux/slab.h>
52 : #include <linux/err.h>
53 : #include <linux/kthread.h>
54 : #include <linux/kernel.h>
55 : #include <linux/syscalls.h>
56 :
57 : #include <linux/audit.h>
58 :
59 : #include <net/sock.h>
60 : #include <net/netlink.h>
61 : #include <linux/skbuff.h>
62 : #ifdef CONFIG_SECURITY
63 : #include <linux/security.h>
64 : #endif
65 : #include <linux/freezer.h>
66 : #include <linux/tty.h>
67 : #include <linux/pid_namespace.h>
68 : #include <net/netns/generic.h>
69 :
70 : #include "audit.h"
71 :
72 : /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
73 : * (Initialization happens after skb_init is called.) */
74 : #define AUDIT_DISABLED -1
75 : #define AUDIT_UNINITIALIZED 0
76 : #define AUDIT_INITIALIZED 1
77 : static int audit_initialized;
78 :
79 : #define AUDIT_OFF 0
80 : #define AUDIT_ON 1
81 : #define AUDIT_LOCKED 2
82 : u32 audit_enabled;
83 : u32 audit_ever_enabled;
84 :
85 : EXPORT_SYMBOL_GPL(audit_enabled);
86 :
87 : /* Default state when kernel boots without any parameters. */
88 : static u32 audit_default;
89 :
90 : /* If auditing cannot proceed, audit_failure selects what happens. */
91 : static u32 audit_failure = AUDIT_FAIL_PRINTK;
92 :
93 : /*
94 : * If audit records are to be written to the netlink socket, audit_pid
95 : * contains the pid of the auditd process and audit_nlk_portid contains
96 : * the portid to use to send netlink messages to that process.
97 : */
98 : int audit_pid;
99 : static __u32 audit_nlk_portid;
100 :
101 : /* If audit_rate_limit is non-zero, limit the rate of sending audit records
102 : * to that number per second. This prevents DoS attacks, but results in
103 : * audit records being dropped. */
104 : static u32 audit_rate_limit;
105 :
106 : /* Number of outstanding audit_buffers allowed.
107 : * When set to zero, this means unlimited. */
108 : static u32 audit_backlog_limit = 64;
109 : #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
110 : static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
111 : static u32 audit_backlog_wait_overflow = 0;
112 :
113 : /* The identity of the user shutting down the audit system. */
114 : kuid_t audit_sig_uid = INVALID_UID;
115 : pid_t audit_sig_pid = -1;
116 : u32 audit_sig_sid = 0;
117 :
118 : /* Records can be lost in several ways:
119 : 0) [suppressed in audit_alloc]
120 : 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
121 : 2) out of memory in audit_log_move [alloc_skb]
122 : 3) suppressed due to audit_rate_limit
123 : 4) suppressed due to audit_backlog_limit
124 : */
125 : static atomic_t audit_lost = ATOMIC_INIT(0);
126 :
127 : /* The netlink socket. */
128 : static struct sock *audit_sock;
129 : static int audit_net_id;
130 :
131 : /* Hash for inode-based rules */
132 : struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
133 :
134 : /* The audit_freelist is a list of pre-allocated audit buffers (if more
135 : * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
136 : * being placed on the freelist). */
137 : static DEFINE_SPINLOCK(audit_freelist_lock);
138 : static int audit_freelist_count;
139 : static LIST_HEAD(audit_freelist);
140 :
141 : static struct sk_buff_head audit_skb_queue;
142 : /* queue of skbs to send to auditd when/if it comes back */
143 : static struct sk_buff_head audit_skb_hold_queue;
144 : static struct task_struct *kauditd_task;
145 : static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
146 : static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
147 :
148 : static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
149 : .mask = -1,
150 : .features = 0,
151 : .lock = 0,};
152 :
153 : static char *audit_feature_names[2] = {
154 : "only_unset_loginuid",
155 : "loginuid_immutable",
156 : };
157 :
158 :
159 : /* Serialize requests from userspace. */
160 : DEFINE_MUTEX(audit_cmd_mutex);
161 :
162 : /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
163 : * audit records. Since printk uses a 1024 byte buffer, this buffer
164 : * should be at least that large. */
165 : #define AUDIT_BUFSIZ 1024
166 :
167 : /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
168 : * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
169 : #define AUDIT_MAXFREE (2*NR_CPUS)
170 :
171 : /* The audit_buffer is used when formatting an audit record. The caller
172 : * locks briefly to get the record off the freelist or to allocate the
173 : * buffer, and locks briefly to send the buffer to the netlink layer or
174 : * to place it on a transmit queue. Multiple audit_buffers can be in
175 : * use simultaneously. */
176 : struct audit_buffer {
177 : struct list_head list;
178 : struct sk_buff *skb; /* formatted skb ready to send */
179 : struct audit_context *ctx; /* NULL or associated context */
180 : gfp_t gfp_mask;
181 : };
182 :
183 : struct audit_reply {
184 : __u32 portid;
185 : struct net *net;
186 : struct sk_buff *skb;
187 : };
188 :
189 : static void audit_set_portid(struct audit_buffer *ab, __u32 portid)
190 : {
191 0 : if (ab) {
192 0 : struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
193 0 : nlh->nlmsg_pid = portid;
194 : }
195 : }
196 :
197 0 : void audit_panic(const char *message)
198 : {
199 0 : switch (audit_failure) {
200 : case AUDIT_FAIL_SILENT:
201 : break;
202 : case AUDIT_FAIL_PRINTK:
203 0 : if (printk_ratelimit())
204 0 : pr_err("%s\n", message);
205 : break;
206 : case AUDIT_FAIL_PANIC:
207 : /* test audit_pid since printk is always losey, why bother? */
208 0 : if (audit_pid)
209 0 : panic("audit: %s\n", message);
210 : break;
211 : }
212 0 : }
213 :
214 : static inline int audit_rate_check(void)
215 : {
216 : static unsigned long last_check = 0;
217 : static int messages = 0;
218 : static DEFINE_SPINLOCK(lock);
219 : unsigned long flags;
220 : unsigned long now;
221 : unsigned long elapsed;
222 : int retval = 0;
223 :
224 1 : if (!audit_rate_limit) return 1;
225 :
226 0 : spin_lock_irqsave(&lock, flags);
227 0 : if (++messages < audit_rate_limit) {
228 : retval = 1;
229 : } else {
230 0 : now = jiffies;
231 0 : elapsed = now - last_check;
232 0 : if (elapsed > HZ) {
233 0 : last_check = now;
234 0 : messages = 0;
235 : retval = 1;
236 : }
237 : }
238 : spin_unlock_irqrestore(&lock, flags);
239 :
240 : return retval;
241 : }
242 :
243 : /**
244 : * audit_log_lost - conditionally log lost audit message event
245 : * @message: the message stating reason for lost audit message
246 : *
247 : * Emit at least 1 message per second, even if audit_rate_check is
248 : * throttling.
249 : * Always increment the lost messages counter.
250 : */
251 0 : void audit_log_lost(const char *message)
252 : {
253 : static unsigned long last_msg = 0;
254 : static DEFINE_SPINLOCK(lock);
255 : unsigned long flags;
256 : unsigned long now;
257 : int print;
258 :
259 : atomic_inc(&audit_lost);
260 :
261 0 : print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
262 :
263 0 : if (!print) {
264 0 : spin_lock_irqsave(&lock, flags);
265 0 : now = jiffies;
266 0 : if (now - last_msg > HZ) {
267 : print = 1;
268 0 : last_msg = now;
269 : }
270 : spin_unlock_irqrestore(&lock, flags);
271 : }
272 :
273 0 : if (print) {
274 0 : if (printk_ratelimit())
275 0 : pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
276 : atomic_read(&audit_lost),
277 : audit_rate_limit,
278 : audit_backlog_limit);
279 0 : audit_panic(message);
280 : }
281 0 : }
282 :
283 0 : static int audit_log_config_change(char *function_name, u32 new, u32 old,
284 : int allow_changes)
285 : {
286 : struct audit_buffer *ab;
287 : int rc = 0;
288 :
289 0 : ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
290 0 : if (unlikely(!ab))
291 : return rc;
292 0 : audit_log_format(ab, "%s=%u old=%u", function_name, new, old);
293 : audit_log_session_info(ab);
294 : rc = audit_log_task_context(ab);
295 : if (rc)
296 : allow_changes = 0; /* Something weird, deny request */
297 0 : audit_log_format(ab, " res=%d", allow_changes);
298 0 : audit_log_end(ab);
299 0 : return rc;
300 : }
301 :
302 0 : static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
303 : {
304 : int allow_changes, rc = 0;
305 0 : u32 old = *to_change;
306 :
307 : /* check if we are locked */
308 0 : if (audit_enabled == AUDIT_LOCKED)
309 : allow_changes = 0;
310 : else
311 : allow_changes = 1;
312 :
313 0 : if (audit_enabled != AUDIT_OFF) {
314 0 : rc = audit_log_config_change(function_name, new, old, allow_changes);
315 0 : if (rc)
316 : allow_changes = 0;
317 : }
318 :
319 : /* If we are allowed, make the change */
320 0 : if (allow_changes == 1)
321 0 : *to_change = new;
322 : /* Not allowed, update reason */
323 0 : else if (rc == 0)
324 : rc = -EPERM;
325 0 : return rc;
326 : }
327 :
328 : static int audit_set_rate_limit(u32 limit)
329 : {
330 0 : return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
331 : }
332 :
333 : static int audit_set_backlog_limit(u32 limit)
334 : {
335 0 : return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
336 : }
337 :
338 : static int audit_set_backlog_wait_time(u32 timeout)
339 : {
340 0 : return audit_do_config_change("audit_backlog_wait_time",
341 : &audit_backlog_wait_time, timeout);
342 : }
343 :
344 0 : static int audit_set_enabled(u32 state)
345 : {
346 : int rc;
347 0 : if (state < AUDIT_OFF || state > AUDIT_LOCKED)
348 : return -EINVAL;
349 :
350 0 : rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
351 0 : if (!rc)
352 0 : audit_ever_enabled |= !!state;
353 :
354 0 : return rc;
355 : }
356 :
357 : static int audit_set_failure(u32 state)
358 : {
359 0 : if (state != AUDIT_FAIL_SILENT
360 : && state != AUDIT_FAIL_PRINTK
361 : && state != AUDIT_FAIL_PANIC)
362 : return -EINVAL;
363 :
364 0 : return audit_do_config_change("audit_failure", &audit_failure, state);
365 : }
366 :
367 : /*
368 : * Queue skbs to be sent to auditd when/if it comes back. These skbs should
369 : * already have been sent via prink/syslog and so if these messages are dropped
370 : * it is not a huge concern since we already passed the audit_log_lost()
371 : * notification and stuff. This is just nice to get audit messages during
372 : * boot before auditd is running or messages generated while auditd is stopped.
373 : * This only holds messages is audit_default is set, aka booting with audit=1
374 : * or building your kernel that way.
375 : */
376 1 : static void audit_hold_skb(struct sk_buff *skb)
377 : {
378 1 : if (audit_default &&
379 0 : (!audit_backlog_limit ||
380 0 : skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit))
381 0 : skb_queue_tail(&audit_skb_hold_queue, skb);
382 : else
383 1 : kfree_skb(skb);
384 1 : }
385 :
386 : /*
387 : * For one reason or another this nlh isn't getting delivered to the userspace
388 : * audit daemon, just send it to printk.
389 : */
390 1 : static void audit_printk_skb(struct sk_buff *skb)
391 : {
392 : struct nlmsghdr *nlh = nlmsg_hdr(skb);
393 1 : char *data = nlmsg_data(nlh);
394 :
395 1 : if (nlh->nlmsg_type != AUDIT_EOE) {
396 1 : if (printk_ratelimit())
397 1 : pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
398 : else
399 0 : audit_log_lost("printk limit exceeded");
400 : }
401 :
402 1 : audit_hold_skb(skb);
403 1 : }
404 :
405 0 : static void kauditd_send_skb(struct sk_buff *skb)
406 : {
407 : int err;
408 : /* take a reference in case we can't send it and we want to hold it */
409 : skb_get(skb);
410 0 : err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
411 0 : if (err < 0) {
412 : BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
413 0 : if (audit_pid) {
414 0 : pr_err("*NO* daemon at audit_pid=%d\n", audit_pid);
415 0 : audit_log_lost("auditd disappeared");
416 0 : audit_pid = 0;
417 0 : audit_sock = NULL;
418 : }
419 : /* we might get lucky and get this in the next auditd */
420 0 : audit_hold_skb(skb);
421 : } else
422 : /* drop the extra reference if sent ok */
423 0 : consume_skb(skb);
424 0 : }
425 :
426 : /*
427 : * kauditd_send_multicast_skb - send the skb to multicast userspace listeners
428 : *
429 : * This function doesn't consume an skb as might be expected since it has to
430 : * copy it anyways.
431 : */
432 1 : static void kauditd_send_multicast_skb(struct sk_buff *skb, gfp_t gfp_mask)
433 : {
434 : struct sk_buff *copy;
435 1 : struct audit_net *aunet = net_generic(&init_net, audit_net_id);
436 1 : struct sock *sock = aunet->nlsk;
437 :
438 1 : if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
439 : return;
440 :
441 : /*
442 : * The seemingly wasteful skb_copy() rather than bumping the refcount
443 : * using skb_get() is necessary because non-standard mods are made to
444 : * the skb by the original kaudit unicast socket send routine. The
445 : * existing auditd daemon assumes this breakage. Fixing this would
446 : * require co-ordinating a change in the established protocol between
447 : * the kaudit kernel subsystem and the auditd userspace code. There is
448 : * no reason for new multicast clients to continue with this
449 : * non-compliance.
450 : */
451 0 : copy = skb_copy(skb, gfp_mask);
452 0 : if (!copy)
453 : return;
454 :
455 : nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, gfp_mask);
456 : }
457 :
458 : /*
459 : * flush_hold_queue - empty the hold queue if auditd appears
460 : *
461 : * If auditd just started, drain the queue of messages already
462 : * sent to syslog/printk. Remember loss here is ok. We already
463 : * called audit_log_lost() if it didn't go out normally. so the
464 : * race between the skb_dequeue and the next check for audit_pid
465 : * doesn't matter.
466 : *
467 : * If you ever find kauditd to be too slow we can get a perf win
468 : * by doing our own locking and keeping better track if there
469 : * are messages in this queue. I don't see the need now, but
470 : * in 5 years when I want to play with this again I'll see this
471 : * note and still have no friggin idea what i'm thinking today.
472 : */
473 0 : static void flush_hold_queue(void)
474 : {
475 : struct sk_buff *skb;
476 :
477 0 : if (!audit_default || !audit_pid)
478 : return;
479 :
480 0 : skb = skb_dequeue(&audit_skb_hold_queue);
481 0 : if (likely(!skb))
482 : return;
483 :
484 0 : while (skb && audit_pid) {
485 0 : kauditd_send_skb(skb);
486 0 : skb = skb_dequeue(&audit_skb_hold_queue);
487 : }
488 :
489 : /*
490 : * if auditd just disappeared but we
491 : * dequeued an skb we need to drop ref
492 : */
493 0 : if (skb)
494 0 : consume_skb(skb);
495 : }
496 :
497 0 : static int kauditd_thread(void *dummy)
498 : {
499 0 : set_freezable();
500 0 : while (!kthread_should_stop()) {
501 : struct sk_buff *skb;
502 :
503 0 : flush_hold_queue();
504 :
505 0 : skb = skb_dequeue(&audit_skb_queue);
506 :
507 0 : if (skb) {
508 0 : if (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit)
509 0 : wake_up(&audit_backlog_wait);
510 0 : if (audit_pid)
511 0 : kauditd_send_skb(skb);
512 : else
513 0 : audit_printk_skb(skb);
514 0 : continue;
515 : }
516 :
517 0 : wait_event_freezable(kauditd_wait, skb_queue_len(&audit_skb_queue));
518 : }
519 0 : return 0;
520 : }
521 :
522 0 : int audit_send_list(void *_dest)
523 : {
524 : struct audit_netlink_list *dest = _dest;
525 : struct sk_buff *skb;
526 0 : struct net *net = dest->net;
527 0 : struct audit_net *aunet = net_generic(net, audit_net_id);
528 :
529 : /* wait for parent to finish and send an ACK */
530 0 : mutex_lock(&audit_cmd_mutex);
531 0 : mutex_unlock(&audit_cmd_mutex);
532 :
533 0 : while ((skb = __skb_dequeue(&dest->q)) != NULL)
534 0 : netlink_unicast(aunet->nlsk, skb, dest->portid, 0);
535 :
536 : put_net(net);
537 0 : kfree(dest);
538 :
539 0 : return 0;
540 : }
541 :
542 0 : struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done,
543 : int multi, const void *payload, int size)
544 : {
545 : struct sk_buff *skb;
546 : struct nlmsghdr *nlh;
547 : void *data;
548 0 : int flags = multi ? NLM_F_MULTI : 0;
549 0 : int t = done ? NLMSG_DONE : type;
550 :
551 : skb = nlmsg_new(size, GFP_KERNEL);
552 0 : if (!skb)
553 : return NULL;
554 :
555 0 : nlh = nlmsg_put(skb, portid, seq, t, size, flags);
556 0 : if (!nlh)
557 : goto out_kfree_skb;
558 0 : data = nlmsg_data(nlh);
559 0 : memcpy(data, payload, size);
560 0 : return skb;
561 :
562 : out_kfree_skb:
563 0 : kfree_skb(skb);
564 0 : return NULL;
565 : }
566 :
567 0 : static int audit_send_reply_thread(void *arg)
568 : {
569 : struct audit_reply *reply = (struct audit_reply *)arg;
570 0 : struct net *net = reply->net;
571 0 : struct audit_net *aunet = net_generic(net, audit_net_id);
572 :
573 0 : mutex_lock(&audit_cmd_mutex);
574 0 : mutex_unlock(&audit_cmd_mutex);
575 :
576 : /* Ignore failure. It'll only happen if the sender goes away,
577 : because our timeout is set to infinite. */
578 0 : netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0);
579 : put_net(net);
580 0 : kfree(reply);
581 0 : return 0;
582 : }
583 : /**
584 : * audit_send_reply - send an audit reply message via netlink
585 : * @request_skb: skb of request we are replying to (used to target the reply)
586 : * @seq: sequence number
587 : * @type: audit message type
588 : * @done: done (last) flag
589 : * @multi: multi-part message flag
590 : * @payload: payload data
591 : * @size: payload size
592 : *
593 : * Allocates an skb, builds the netlink message, and sends it to the port id.
594 : * No failure notifications.
595 : */
596 0 : static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
597 : int multi, const void *payload, int size)
598 : {
599 0 : u32 portid = NETLINK_CB(request_skb).portid;
600 0 : struct net *net = sock_net(NETLINK_CB(request_skb).sk);
601 : struct sk_buff *skb;
602 : struct task_struct *tsk;
603 : struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
604 : GFP_KERNEL);
605 :
606 0 : if (!reply)
607 : return;
608 :
609 0 : skb = audit_make_reply(portid, seq, type, done, multi, payload, size);
610 0 : if (!skb)
611 : goto out;
612 :
613 0 : reply->net = get_net(net);
614 0 : reply->portid = portid;
615 0 : reply->skb = skb;
616 :
617 0 : tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
618 0 : if (!IS_ERR(tsk))
619 : return;
620 0 : kfree_skb(skb);
621 : out:
622 0 : kfree(reply);
623 : }
624 :
625 : /*
626 : * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
627 : * control messages.
628 : */
629 0 : static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
630 : {
631 : int err = 0;
632 :
633 : /* Only support initial user namespace for now. */
634 : /*
635 : * We return ECONNREFUSED because it tricks userspace into thinking
636 : * that audit was not configured into the kernel. Lots of users
637 : * configure their PAM stack (because that's what the distro does)
638 : * to reject login if unable to send messages to audit. If we return
639 : * ECONNREFUSED the PAM stack thinks the kernel does not have audit
640 : * configured in and will let login proceed. If we return EPERM
641 : * userspace will reject all logins. This should be removed when we
642 : * support non init namespaces!!
643 : */
644 : if (current_user_ns() != &init_user_ns)
645 : return -ECONNREFUSED;
646 :
647 0 : switch (msg_type) {
648 : case AUDIT_LIST:
649 : case AUDIT_ADD:
650 : case AUDIT_DEL:
651 : return -EOPNOTSUPP;
652 : case AUDIT_GET:
653 : case AUDIT_SET:
654 : case AUDIT_GET_FEATURE:
655 : case AUDIT_SET_FEATURE:
656 : case AUDIT_LIST_RULES:
657 : case AUDIT_ADD_RULE:
658 : case AUDIT_DEL_RULE:
659 : case AUDIT_SIGNAL_INFO:
660 : case AUDIT_TTY_GET:
661 : case AUDIT_TTY_SET:
662 : case AUDIT_TRIM:
663 : case AUDIT_MAKE_EQUIV:
664 : /* Only support auditd and auditctl in initial pid namespace
665 : * for now. */
666 0 : if ((task_active_pid_ns(current) != &init_pid_ns))
667 : return -EPERM;
668 :
669 0 : if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
670 : err = -EPERM;
671 : break;
672 : case AUDIT_USER:
673 : case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
674 : case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
675 0 : if (!netlink_capable(skb, CAP_AUDIT_WRITE))
676 : err = -EPERM;
677 : break;
678 : default: /* bad msg */
679 : err = -EINVAL;
680 : }
681 :
682 0 : return err;
683 : }
684 :
685 0 : static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
686 : {
687 : int rc = 0;
688 0 : uid_t uid = from_kuid(&init_user_ns, current_uid());
689 : pid_t pid = task_tgid_nr(current);
690 :
691 0 : if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
692 0 : *ab = NULL;
693 0 : return rc;
694 : }
695 :
696 0 : *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
697 0 : if (unlikely(!*ab))
698 : return rc;
699 0 : audit_log_format(*ab, "pid=%d uid=%u", pid, uid);
700 0 : audit_log_session_info(*ab);
701 : audit_log_task_context(*ab);
702 :
703 0 : return rc;
704 : }
705 :
706 0 : int is_audit_feature_set(int i)
707 : {
708 0 : return af.features & AUDIT_FEATURE_TO_MASK(i);
709 : }
710 :
711 :
712 0 : static int audit_get_feature(struct sk_buff *skb)
713 : {
714 : u32 seq;
715 :
716 0 : seq = nlmsg_hdr(skb)->nlmsg_seq;
717 :
718 0 : audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
719 :
720 0 : return 0;
721 : }
722 :
723 0 : static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
724 : u32 old_lock, u32 new_lock, int res)
725 : {
726 : struct audit_buffer *ab;
727 :
728 0 : if (audit_enabled == AUDIT_OFF)
729 0 : return;
730 :
731 0 : ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE);
732 0 : audit_log_task_info(ab, current);
733 0 : audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
734 : audit_feature_names[which], !!old_feature, !!new_feature,
735 : !!old_lock, !!new_lock, res);
736 0 : audit_log_end(ab);
737 : }
738 :
739 0 : static int audit_set_feature(struct sk_buff *skb)
740 : {
741 : struct audit_features *uaf;
742 : int i;
743 :
744 : BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
745 : uaf = nlmsg_data(nlmsg_hdr(skb));
746 :
747 : /* if there is ever a version 2 we should handle that here */
748 :
749 0 : for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
750 0 : u32 feature = AUDIT_FEATURE_TO_MASK(i);
751 : u32 old_feature, new_feature, old_lock, new_lock;
752 :
753 : /* if we are not changing this feature, move along */
754 0 : if (!(feature & uaf->mask))
755 0 : continue;
756 :
757 0 : old_feature = af.features & feature;
758 0 : new_feature = uaf->features & feature;
759 0 : new_lock = (uaf->lock | af.lock) & feature;
760 0 : old_lock = af.lock & feature;
761 :
762 : /* are we changing a locked feature? */
763 0 : if (old_lock && (new_feature != old_feature)) {
764 0 : audit_log_feature_change(i, old_feature, new_feature,
765 : old_lock, new_lock, 0);
766 0 : return -EPERM;
767 : }
768 : }
769 : /* nothing invalid, do the changes */
770 0 : for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
771 0 : u32 feature = AUDIT_FEATURE_TO_MASK(i);
772 : u32 old_feature, new_feature, old_lock, new_lock;
773 :
774 : /* if we are not changing this feature, move along */
775 0 : if (!(feature & uaf->mask))
776 0 : continue;
777 :
778 0 : old_feature = af.features & feature;
779 0 : new_feature = uaf->features & feature;
780 0 : old_lock = af.lock & feature;
781 0 : new_lock = (uaf->lock | af.lock) & feature;
782 :
783 0 : if (new_feature != old_feature)
784 0 : audit_log_feature_change(i, old_feature, new_feature,
785 : old_lock, new_lock, 1);
786 :
787 0 : if (new_feature)
788 0 : af.features |= feature;
789 : else
790 0 : af.features &= ~feature;
791 0 : af.lock |= new_lock;
792 : }
793 :
794 : return 0;
795 : }
796 :
797 0 : static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
798 : {
799 : u32 seq;
800 : void *data;
801 : int err;
802 : struct audit_buffer *ab;
803 0 : u16 msg_type = nlh->nlmsg_type;
804 : struct audit_sig_info *sig_data;
805 : char *ctx = NULL;
806 : u32 len;
807 :
808 0 : err = audit_netlink_ok(skb, msg_type);
809 0 : if (err)
810 : return err;
811 :
812 : /* As soon as there's any sign of userspace auditd,
813 : * start kauditd to talk to it */
814 0 : if (!kauditd_task) {
815 0 : kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
816 0 : if (IS_ERR(kauditd_task)) {
817 : err = PTR_ERR(kauditd_task);
818 0 : kauditd_task = NULL;
819 0 : return err;
820 : }
821 : }
822 0 : seq = nlh->nlmsg_seq;
823 0 : data = nlmsg_data(nlh);
824 :
825 0 : switch (msg_type) {
826 : case AUDIT_GET: {
827 : struct audit_status s;
828 0 : memset(&s, 0, sizeof(s));
829 0 : s.enabled = audit_enabled;
830 0 : s.failure = audit_failure;
831 0 : s.pid = audit_pid;
832 0 : s.rate_limit = audit_rate_limit;
833 0 : s.backlog_limit = audit_backlog_limit;
834 0 : s.lost = atomic_read(&audit_lost);
835 0 : s.backlog = skb_queue_len(&audit_skb_queue);
836 0 : s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
837 0 : s.backlog_wait_time = audit_backlog_wait_time;
838 0 : audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
839 : break;
840 : }
841 : case AUDIT_SET: {
842 : struct audit_status s;
843 0 : memset(&s, 0, sizeof(s));
844 : /* guard against past and future API changes */
845 0 : memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
846 0 : if (s.mask & AUDIT_STATUS_ENABLED) {
847 0 : err = audit_set_enabled(s.enabled);
848 0 : if (err < 0)
849 0 : return err;
850 : }
851 0 : if (s.mask & AUDIT_STATUS_FAILURE) {
852 0 : err = audit_set_failure(s.failure);
853 0 : if (err < 0)
854 : return err;
855 : }
856 0 : if (s.mask & AUDIT_STATUS_PID) {
857 0 : int new_pid = s.pid;
858 :
859 0 : if ((!new_pid) && (task_tgid_vnr(current) != audit_pid))
860 : return -EACCES;
861 0 : if (audit_enabled != AUDIT_OFF)
862 0 : audit_log_config_change("audit_pid", new_pid, audit_pid, 1);
863 0 : audit_pid = new_pid;
864 0 : audit_nlk_portid = NETLINK_CB(skb).portid;
865 0 : audit_sock = skb->sk;
866 : }
867 0 : if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
868 0 : err = audit_set_rate_limit(s.rate_limit);
869 0 : if (err < 0)
870 : return err;
871 : }
872 0 : if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
873 0 : err = audit_set_backlog_limit(s.backlog_limit);
874 0 : if (err < 0)
875 : return err;
876 : }
877 0 : if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
878 0 : if (sizeof(s) > (size_t)nlh->nlmsg_len)
879 : return -EINVAL;
880 0 : if (s.backlog_wait_time < 0 ||
881 0 : s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
882 : return -EINVAL;
883 : err = audit_set_backlog_wait_time(s.backlog_wait_time);
884 0 : if (err < 0)
885 : return err;
886 : }
887 0 : break;
888 : }
889 : case AUDIT_GET_FEATURE:
890 0 : err = audit_get_feature(skb);
891 0 : if (err)
892 : return err;
893 : break;
894 : case AUDIT_SET_FEATURE:
895 0 : err = audit_set_feature(skb);
896 0 : if (err)
897 : return err;
898 : break;
899 : case AUDIT_USER:
900 : case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
901 : case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
902 0 : if (!audit_enabled && msg_type != AUDIT_USER_AVC)
903 : return 0;
904 :
905 0 : err = audit_filter_user(msg_type);
906 0 : if (err == 1) { /* match or error */
907 : err = 0;
908 0 : if (msg_type == AUDIT_USER_TTY) {
909 0 : err = tty_audit_push_current();
910 0 : if (err)
911 : break;
912 : }
913 0 : mutex_unlock(&audit_cmd_mutex);
914 0 : audit_log_common_recv_msg(&ab, msg_type);
915 0 : if (msg_type != AUDIT_USER_TTY)
916 0 : audit_log_format(ab, " msg='%.*s'",
917 : AUDIT_MESSAGE_TEXT_MAX,
918 : (char *)data);
919 : else {
920 : int size;
921 :
922 0 : audit_log_format(ab, " data=");
923 : size = nlmsg_len(nlh);
924 0 : if (size > 0 &&
925 0 : ((unsigned char *)data)[size - 1] == '\0')
926 0 : size--;
927 0 : audit_log_n_untrustedstring(ab, data, size);
928 : }
929 0 : audit_set_portid(ab, NETLINK_CB(skb).portid);
930 0 : audit_log_end(ab);
931 0 : mutex_lock(&audit_cmd_mutex);
932 : }
933 : break;
934 : case AUDIT_ADD_RULE:
935 : case AUDIT_DEL_RULE:
936 0 : if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
937 : return -EINVAL;
938 0 : if (audit_enabled == AUDIT_LOCKED) {
939 0 : audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
940 0 : audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled);
941 0 : audit_log_end(ab);
942 0 : return -EPERM;
943 : }
944 0 : err = audit_rule_change(msg_type, NETLINK_CB(skb).portid,
945 : seq, data, nlmsg_len(nlh));
946 0 : break;
947 : case AUDIT_LIST_RULES:
948 0 : err = audit_list_rules_send(skb, seq);
949 0 : break;
950 : case AUDIT_TRIM:
951 : audit_trim_trees();
952 0 : audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
953 0 : audit_log_format(ab, " op=trim res=1");
954 0 : audit_log_end(ab);
955 0 : break;
956 : case AUDIT_MAKE_EQUIV: {
957 0 : void *bufp = data;
958 : u32 sizes[2];
959 0 : size_t msglen = nlmsg_len(nlh);
960 : char *old, *new;
961 :
962 : err = -EINVAL;
963 0 : if (msglen < 2 * sizeof(u32))
964 : break;
965 0 : memcpy(sizes, bufp, 2 * sizeof(u32));
966 0 : bufp += 2 * sizeof(u32);
967 0 : msglen -= 2 * sizeof(u32);
968 0 : old = audit_unpack_string(&bufp, &msglen, sizes[0]);
969 0 : if (IS_ERR(old)) {
970 : err = PTR_ERR(old);
971 0 : break;
972 : }
973 0 : new = audit_unpack_string(&bufp, &msglen, sizes[1]);
974 0 : if (IS_ERR(new)) {
975 : err = PTR_ERR(new);
976 0 : kfree(old);
977 0 : break;
978 : }
979 : /* OK, here comes... */
980 : err = audit_tag_tree(old, new);
981 :
982 0 : audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
983 :
984 0 : audit_log_format(ab, " op=make_equiv old=");
985 0 : audit_log_untrustedstring(ab, old);
986 0 : audit_log_format(ab, " new=");
987 0 : audit_log_untrustedstring(ab, new);
988 0 : audit_log_format(ab, " res=%d", !err);
989 0 : audit_log_end(ab);
990 0 : kfree(old);
991 0 : kfree(new);
992 0 : break;
993 : }
994 : case AUDIT_SIGNAL_INFO:
995 : len = 0;
996 0 : if (audit_sig_sid) {
997 : err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
998 : if (err)
999 : return err;
1000 : }
1001 : sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
1002 0 : if (!sig_data) {
1003 : if (audit_sig_sid)
1004 : security_release_secctx(ctx, len);
1005 : return -ENOMEM;
1006 : }
1007 0 : sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
1008 0 : sig_data->pid = audit_sig_pid;
1009 : if (audit_sig_sid) {
1010 : memcpy(sig_data->ctx, ctx, len);
1011 : security_release_secctx(ctx, len);
1012 : }
1013 0 : audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
1014 : sig_data, sizeof(*sig_data) + len);
1015 0 : kfree(sig_data);
1016 0 : break;
1017 : case AUDIT_TTY_GET: {
1018 : struct audit_tty_status s;
1019 0 : struct task_struct *tsk = current;
1020 :
1021 : spin_lock(&tsk->sighand->siglock);
1022 0 : s.enabled = tsk->signal->audit_tty;
1023 0 : s.log_passwd = tsk->signal->audit_tty_log_passwd;
1024 : spin_unlock(&tsk->sighand->siglock);
1025 :
1026 0 : audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
1027 : break;
1028 : }
1029 : case AUDIT_TTY_SET: {
1030 : struct audit_tty_status s, old;
1031 0 : struct task_struct *tsk = current;
1032 : struct audit_buffer *ab;
1033 :
1034 0 : memset(&s, 0, sizeof(s));
1035 : /* guard against past and future API changes */
1036 0 : memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
1037 : /* check if new data is valid */
1038 0 : if ((s.enabled != 0 && s.enabled != 1) ||
1039 0 : (s.log_passwd != 0 && s.log_passwd != 1))
1040 : err = -EINVAL;
1041 :
1042 : spin_lock(&tsk->sighand->siglock);
1043 0 : old.enabled = tsk->signal->audit_tty;
1044 0 : old.log_passwd = tsk->signal->audit_tty_log_passwd;
1045 0 : if (!err) {
1046 0 : tsk->signal->audit_tty = s.enabled;
1047 0 : tsk->signal->audit_tty_log_passwd = s.log_passwd;
1048 : }
1049 : spin_unlock(&tsk->sighand->siglock);
1050 :
1051 0 : audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1052 0 : audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
1053 : " old-log_passwd=%d new-log_passwd=%d res=%d",
1054 : old.enabled, s.enabled, old.log_passwd,
1055 : s.log_passwd, !err);
1056 0 : audit_log_end(ab);
1057 : break;
1058 : }
1059 : default:
1060 : err = -EINVAL;
1061 : break;
1062 : }
1063 :
1064 0 : return err < 0 ? err : 0;
1065 : }
1066 :
1067 : /*
1068 : * Get message from skb. Each message is processed by audit_receive_msg.
1069 : * Malformed skbs with wrong length are discarded silently.
1070 : */
1071 0 : static void audit_receive_skb(struct sk_buff *skb)
1072 : {
1073 : struct nlmsghdr *nlh;
1074 : /*
1075 : * len MUST be signed for nlmsg_next to be able to dec it below 0
1076 : * if the nlmsg_len was not aligned
1077 : */
1078 : int len;
1079 : int err;
1080 :
1081 : nlh = nlmsg_hdr(skb);
1082 0 : len = skb->len;
1083 :
1084 0 : while (nlmsg_ok(nlh, len)) {
1085 0 : err = audit_receive_msg(skb, nlh);
1086 : /* if err or if this message says it wants a response */
1087 0 : if (err || (nlh->nlmsg_flags & NLM_F_ACK))
1088 0 : netlink_ack(skb, nlh, err);
1089 :
1090 : nlh = nlmsg_next(nlh, &len);
1091 : }
1092 0 : }
1093 :
1094 : /* Receive messages from netlink socket. */
1095 0 : static void audit_receive(struct sk_buff *skb)
1096 : {
1097 0 : mutex_lock(&audit_cmd_mutex);
1098 0 : audit_receive_skb(skb);
1099 0 : mutex_unlock(&audit_cmd_mutex);
1100 0 : }
1101 :
1102 : /* Run custom bind function on netlink socket group connect or bind requests. */
1103 0 : static int audit_bind(struct net *net, int group)
1104 : {
1105 0 : if (!capable(CAP_AUDIT_READ))
1106 : return -EPERM;
1107 :
1108 0 : return 0;
1109 : }
1110 :
1111 1 : static int __net_init audit_net_init(struct net *net)
1112 : {
1113 1 : struct netlink_kernel_cfg cfg = {
1114 : .input = audit_receive,
1115 : .bind = audit_bind,
1116 : .flags = NL_CFG_F_NONROOT_RECV,
1117 : .groups = AUDIT_NLGRP_MAX,
1118 : };
1119 :
1120 1 : struct audit_net *aunet = net_generic(net, audit_net_id);
1121 :
1122 1 : aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
1123 1 : if (aunet->nlsk == NULL) {
1124 0 : audit_panic("cannot initialize netlink socket in namespace");
1125 0 : return -ENOMEM;
1126 : }
1127 1 : aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
1128 1 : return 0;
1129 : }
1130 :
1131 0 : static void __net_exit audit_net_exit(struct net *net)
1132 : {
1133 0 : struct audit_net *aunet = net_generic(net, audit_net_id);
1134 0 : struct sock *sock = aunet->nlsk;
1135 0 : if (sock == audit_sock) {
1136 0 : audit_pid = 0;
1137 0 : audit_sock = NULL;
1138 : }
1139 :
1140 0 : RCU_INIT_POINTER(aunet->nlsk, NULL);
1141 0 : synchronize_net();
1142 0 : netlink_kernel_release(sock);
1143 0 : }
1144 :
1145 : static struct pernet_operations audit_net_ops __net_initdata = {
1146 : .init = audit_net_init,
1147 : .exit = audit_net_exit,
1148 : .id = &audit_net_id,
1149 : .size = sizeof(struct audit_net),
1150 : };
1151 :
1152 : /* Initialize audit support at boot time. */
1153 1 : static int __init audit_init(void)
1154 : {
1155 : int i;
1156 :
1157 1 : if (audit_initialized == AUDIT_DISABLED)
1158 : return 0;
1159 :
1160 1 : pr_info("initializing netlink subsys (%s)\n",
1161 : audit_default ? "enabled" : "disabled");
1162 1 : register_pernet_subsys(&audit_net_ops);
1163 :
1164 : skb_queue_head_init(&audit_skb_queue);
1165 : skb_queue_head_init(&audit_skb_hold_queue);
1166 1 : audit_initialized = AUDIT_INITIALIZED;
1167 1 : audit_enabled = audit_default;
1168 1 : audit_ever_enabled |= !!audit_default;
1169 :
1170 1 : audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
1171 :
1172 33 : for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1173 32 : INIT_LIST_HEAD(&audit_inode_hash[i]);
1174 :
1175 : return 0;
1176 : }
1177 : __initcall(audit_init);
1178 :
1179 : /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1180 0 : static int __init audit_enable(char *str)
1181 : {
1182 0 : audit_default = !!simple_strtol(str, NULL, 0);
1183 0 : if (!audit_default)
1184 0 : audit_initialized = AUDIT_DISABLED;
1185 :
1186 0 : pr_info("%s\n", audit_default ?
1187 : "enabled (after initialization)" : "disabled (until reboot)");
1188 :
1189 0 : return 1;
1190 : }
1191 : __setup("audit=", audit_enable);
1192 :
1193 : /* Process kernel command-line parameter at boot time.
1194 : * audit_backlog_limit=<n> */
1195 0 : static int __init audit_backlog_limit_set(char *str)
1196 : {
1197 : u32 audit_backlog_limit_arg;
1198 :
1199 0 : pr_info("audit_backlog_limit: ");
1200 0 : if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
1201 0 : pr_cont("using default of %u, unable to parse %s\n",
1202 : audit_backlog_limit, str);
1203 0 : return 1;
1204 : }
1205 :
1206 0 : audit_backlog_limit = audit_backlog_limit_arg;
1207 0 : pr_cont("%d\n", audit_backlog_limit);
1208 :
1209 0 : return 1;
1210 : }
1211 : __setup("audit_backlog_limit=", audit_backlog_limit_set);
1212 :
1213 1 : static void audit_buffer_free(struct audit_buffer *ab)
1214 : {
1215 : unsigned long flags;
1216 :
1217 1 : if (!ab)
1218 1 : return;
1219 :
1220 1 : if (ab->skb)
1221 0 : kfree_skb(ab->skb);
1222 :
1223 1 : spin_lock_irqsave(&audit_freelist_lock, flags);
1224 1 : if (audit_freelist_count > AUDIT_MAXFREE)
1225 0 : kfree(ab);
1226 : else {
1227 1 : audit_freelist_count++;
1228 1 : list_add(&ab->list, &audit_freelist);
1229 : }
1230 : spin_unlock_irqrestore(&audit_freelist_lock, flags);
1231 : }
1232 :
1233 1 : static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
1234 : gfp_t gfp_mask, int type)
1235 : {
1236 : unsigned long flags;
1237 : struct audit_buffer *ab = NULL;
1238 : struct nlmsghdr *nlh;
1239 :
1240 1 : spin_lock_irqsave(&audit_freelist_lock, flags);
1241 1 : if (!list_empty(&audit_freelist)) {
1242 : ab = list_entry(audit_freelist.next,
1243 : struct audit_buffer, list);
1244 : list_del(&ab->list);
1245 0 : --audit_freelist_count;
1246 : }
1247 : spin_unlock_irqrestore(&audit_freelist_lock, flags);
1248 :
1249 1 : if (!ab) {
1250 : ab = kmalloc(sizeof(*ab), gfp_mask);
1251 1 : if (!ab)
1252 : goto err;
1253 : }
1254 :
1255 1 : ab->ctx = ctx;
1256 1 : ab->gfp_mask = gfp_mask;
1257 :
1258 1 : ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1259 1 : if (!ab->skb)
1260 : goto err;
1261 :
1262 : nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0);
1263 1 : if (!nlh)
1264 : goto out_kfree_skb;
1265 :
1266 : return ab;
1267 :
1268 : out_kfree_skb:
1269 0 : kfree_skb(ab->skb);
1270 0 : ab->skb = NULL;
1271 : err:
1272 0 : audit_buffer_free(ab);
1273 0 : return NULL;
1274 : }
1275 :
1276 : /**
1277 : * audit_serial - compute a serial number for the audit record
1278 : *
1279 : * Compute a serial number for the audit record. Audit records are
1280 : * written to user-space as soon as they are generated, so a complete
1281 : * audit record may be written in several pieces. The timestamp of the
1282 : * record and this serial number are used by the user-space tools to
1283 : * determine which pieces belong to the same audit record. The
1284 : * (timestamp,serial) tuple is unique for each syscall and is live from
1285 : * syscall entry to syscall exit.
1286 : *
1287 : * NOTE: Another possibility is to store the formatted records off the
1288 : * audit context (for those records that have a context), and emit them
1289 : * all at syscall exit. However, this could delay the reporting of
1290 : * significant errors until syscall exit (or never, if the system
1291 : * halts).
1292 : */
1293 1 : unsigned int audit_serial(void)
1294 : {
1295 : static atomic_t serial = ATOMIC_INIT(0);
1296 :
1297 1 : return atomic_add_return(1, &serial);
1298 : }
1299 :
1300 : static inline void audit_get_stamp(struct audit_context *ctx,
1301 : struct timespec *t, unsigned int *serial)
1302 : {
1303 : if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1304 1 : *t = CURRENT_TIME;
1305 1 : *serial = audit_serial();
1306 : }
1307 : }
1308 :
1309 : /*
1310 : * Wait for auditd to drain the queue a little
1311 : */
1312 0 : static long wait_for_auditd(long sleep_time)
1313 : {
1314 0 : DECLARE_WAITQUEUE(wait, current);
1315 0 : set_current_state(TASK_UNINTERRUPTIBLE);
1316 0 : add_wait_queue_exclusive(&audit_backlog_wait, &wait);
1317 :
1318 0 : if (audit_backlog_limit &&
1319 0 : skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
1320 0 : sleep_time = schedule_timeout(sleep_time);
1321 :
1322 0 : __set_current_state(TASK_RUNNING);
1323 0 : remove_wait_queue(&audit_backlog_wait, &wait);
1324 :
1325 0 : return sleep_time;
1326 : }
1327 :
1328 : /**
1329 : * audit_log_start - obtain an audit buffer
1330 : * @ctx: audit_context (may be NULL)
1331 : * @gfp_mask: type of allocation
1332 : * @type: audit message type
1333 : *
1334 : * Returns audit_buffer pointer on success or NULL on error.
1335 : *
1336 : * Obtain an audit buffer. This routine does locking to obtain the
1337 : * audit buffer, but then no locking is required for calls to
1338 : * audit_log_*format. If the task (ctx) is a task that is currently in a
1339 : * syscall, then the syscall is marked as auditable and an audit record
1340 : * will be written at syscall exit. If there is no associated task, then
1341 : * task context (ctx) should be NULL.
1342 : */
1343 1 : struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1344 : int type)
1345 : {
1346 : struct audit_buffer *ab = NULL;
1347 : struct timespec t;
1348 : unsigned int uninitialized_var(serial);
1349 : int reserve = 5; /* Allow atomic callers to go up to five
1350 : entries over the normal backlog limit */
1351 1 : unsigned long timeout_start = jiffies;
1352 :
1353 1 : if (audit_initialized != AUDIT_INITIALIZED)
1354 : return NULL;
1355 :
1356 1 : if (unlikely(audit_filter_type(type)))
1357 : return NULL;
1358 :
1359 1 : if (gfp_mask & __GFP_WAIT) {
1360 1 : if (audit_pid && audit_pid == current->pid)
1361 0 : gfp_mask &= ~__GFP_WAIT;
1362 : else
1363 : reserve = 0;
1364 : }
1365 :
1366 1 : while (audit_backlog_limit
1367 1 : && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
1368 0 : if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) {
1369 : long sleep_time;
1370 :
1371 0 : sleep_time = timeout_start + audit_backlog_wait_time - jiffies;
1372 0 : if (sleep_time > 0) {
1373 0 : sleep_time = wait_for_auditd(sleep_time);
1374 0 : if (sleep_time > 0)
1375 0 : continue;
1376 : }
1377 : }
1378 0 : if (audit_rate_check() && printk_ratelimit())
1379 0 : pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1380 : skb_queue_len(&audit_skb_queue),
1381 : audit_backlog_limit);
1382 0 : audit_log_lost("backlog limit exceeded");
1383 0 : audit_backlog_wait_time = audit_backlog_wait_overflow;
1384 0 : wake_up(&audit_backlog_wait);
1385 0 : return NULL;
1386 : }
1387 :
1388 1 : audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
1389 :
1390 1 : ab = audit_buffer_alloc(ctx, gfp_mask, type);
1391 1 : if (!ab) {
1392 0 : audit_log_lost("out of memory in audit_log_start");
1393 0 : return NULL;
1394 : }
1395 :
1396 : audit_get_stamp(ab->ctx, &t, &serial);
1397 :
1398 2 : audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1399 1 : t.tv_sec, t.tv_nsec/1000000, serial);
1400 1 : return ab;
1401 : }
1402 :
1403 : /**
1404 : * audit_expand - expand skb in the audit buffer
1405 : * @ab: audit_buffer
1406 : * @extra: space to add at tail of the skb
1407 : *
1408 : * Returns 0 (no space) on failed expansion, or available space if
1409 : * successful.
1410 : */
1411 : static inline int audit_expand(struct audit_buffer *ab, int extra)
1412 : {
1413 : struct sk_buff *skb = ab->skb;
1414 : int oldtail = skb_tailroom(skb);
1415 0 : int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1416 : int newtail = skb_tailroom(skb);
1417 :
1418 0 : if (ret < 0) {
1419 0 : audit_log_lost("out of memory in audit_expand");
1420 : return 0;
1421 : }
1422 :
1423 0 : skb->truesize += newtail - oldtail;
1424 : return newtail;
1425 : }
1426 :
1427 : /*
1428 : * Format an audit message into the audit buffer. If there isn't enough
1429 : * room in the audit buffer, more room will be allocated and vsnprint
1430 : * will be called a second time. Currently, we assume that a printk
1431 : * can't format message larger than 1024 bytes, so we don't either.
1432 : */
1433 2 : static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1434 : va_list args)
1435 : {
1436 : int len, avail;
1437 2 : struct sk_buff *skb;
1438 : va_list args2;
1439 :
1440 2 : if (!ab)
1441 : return;
1442 :
1443 : BUG_ON(!ab->skb);
1444 2 : skb = ab->skb;
1445 : avail = skb_tailroom(skb);
1446 2 : if (avail == 0) {
1447 : avail = audit_expand(ab, AUDIT_BUFSIZ);
1448 0 : if (!avail)
1449 : goto out;
1450 : }
1451 2 : va_copy(args2, args);
1452 2 : len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1453 2 : if (len >= avail) {
1454 : /* The printk buffer is 1024 bytes long, so if we get
1455 : * here and AUDIT_BUFSIZ is at least 1024, then we can
1456 : * log everything that printk could have logged. */
1457 0 : avail = audit_expand(ab,
1458 0 : max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1459 0 : if (!avail)
1460 : goto out_va_end;
1461 0 : len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1462 : }
1463 2 : if (len > 0)
1464 2 : skb_put(skb, len);
1465 : out_va_end:
1466 2 : va_end(args2);
1467 : out:
1468 : return;
1469 : }
1470 :
1471 : /**
1472 : * audit_log_format - format a message into the audit buffer.
1473 : * @ab: audit_buffer
1474 : * @fmt: format string
1475 : * @...: optional parameters matching @fmt string
1476 : *
1477 : * All the work is done in audit_log_vformat.
1478 : */
1479 1 : void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1480 : {
1481 : va_list args;
1482 :
1483 1 : if (!ab)
1484 0 : return;
1485 1 : va_start(args, fmt);
1486 1 : audit_log_vformat(ab, fmt, args);
1487 1 : va_end(args);
1488 : }
1489 :
1490 : /**
1491 : * audit_log_hex - convert a buffer to hex and append it to the audit skb
1492 : * @ab: the audit_buffer
1493 : * @buf: buffer to convert to hex
1494 : * @len: length of @buf to be converted
1495 : *
1496 : * No return value; failure to expand is silently ignored.
1497 : *
1498 : * This function will take the passed buf and convert it into a string of
1499 : * ascii hex digits. The new string is placed onto the skb.
1500 : */
1501 0 : void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1502 : size_t len)
1503 : {
1504 : int i, avail, new_len;
1505 : unsigned char *ptr;
1506 0 : struct sk_buff *skb;
1507 :
1508 0 : if (!ab)
1509 : return;
1510 :
1511 : BUG_ON(!ab->skb);
1512 0 : skb = ab->skb;
1513 : avail = skb_tailroom(skb);
1514 0 : new_len = len<<1;
1515 0 : if (new_len >= avail) {
1516 : /* Round the buffer request up to the next multiple */
1517 0 : new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1518 : avail = audit_expand(ab, new_len);
1519 0 : if (!avail)
1520 : return;
1521 : }
1522 :
1523 : ptr = skb_tail_pointer(skb);
1524 0 : for (i = 0; i < len; i++)
1525 0 : ptr = hex_byte_pack_upper(ptr, buf[i]);
1526 0 : *ptr = 0;
1527 0 : skb_put(skb, len << 1); /* new string is twice the old string */
1528 : }
1529 :
1530 : /*
1531 : * Format a string of no more than slen characters into the audit buffer,
1532 : * enclosed in quote marks.
1533 : */
1534 0 : void audit_log_n_string(struct audit_buffer *ab, const char *string,
1535 : size_t slen)
1536 : {
1537 : int avail, new_len;
1538 : unsigned char *ptr;
1539 0 : struct sk_buff *skb;
1540 :
1541 0 : if (!ab)
1542 : return;
1543 :
1544 : BUG_ON(!ab->skb);
1545 0 : skb = ab->skb;
1546 : avail = skb_tailroom(skb);
1547 0 : new_len = slen + 3; /* enclosing quotes + null terminator */
1548 0 : if (new_len > avail) {
1549 : avail = audit_expand(ab, new_len);
1550 0 : if (!avail)
1551 : return;
1552 : }
1553 : ptr = skb_tail_pointer(skb);
1554 0 : *ptr++ = '"';
1555 0 : memcpy(ptr, string, slen);
1556 0 : ptr += slen;
1557 0 : *ptr++ = '"';
1558 0 : *ptr = 0;
1559 0 : skb_put(skb, slen + 2); /* don't include null terminator */
1560 : }
1561 :
1562 : /**
1563 : * audit_string_contains_control - does a string need to be logged in hex
1564 : * @string: string to be checked
1565 : * @len: max length of the string to check
1566 : */
1567 0 : int audit_string_contains_control(const char *string, size_t len)
1568 : {
1569 : const unsigned char *p;
1570 0 : for (p = string; p < (const unsigned char *)string + len; p++) {
1571 0 : if (*p == '"' || *p < 0x21 || *p > 0x7e)
1572 : return 1;
1573 : }
1574 : return 0;
1575 : }
1576 :
1577 : /**
1578 : * audit_log_n_untrustedstring - log a string that may contain random characters
1579 : * @ab: audit_buffer
1580 : * @len: length of string (not including trailing null)
1581 : * @string: string to be logged
1582 : *
1583 : * This code will escape a string that is passed to it if the string
1584 : * contains a control character, unprintable character, double quote mark,
1585 : * or a space. Unescaped strings will start and end with a double quote mark.
1586 : * Strings that are escaped are printed in hex (2 digits per char).
1587 : *
1588 : * The caller specifies the number of characters in the string to log, which may
1589 : * or may not be the entire string.
1590 : */
1591 0 : void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1592 : size_t len)
1593 : {
1594 0 : if (audit_string_contains_control(string, len))
1595 0 : audit_log_n_hex(ab, string, len);
1596 : else
1597 0 : audit_log_n_string(ab, string, len);
1598 0 : }
1599 :
1600 : /**
1601 : * audit_log_untrustedstring - log a string that may contain random characters
1602 : * @ab: audit_buffer
1603 : * @string: string to be logged
1604 : *
1605 : * Same as audit_log_n_untrustedstring(), except that strlen is used to
1606 : * determine string length.
1607 : */
1608 0 : void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
1609 : {
1610 0 : audit_log_n_untrustedstring(ab, string, strlen(string));
1611 0 : }
1612 :
1613 : /* This is a helper-function to print the escaped d_path */
1614 0 : void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
1615 : const struct path *path)
1616 : {
1617 : char *p, *pathname;
1618 :
1619 0 : if (prefix)
1620 0 : audit_log_format(ab, "%s", prefix);
1621 :
1622 : /* We will allow 11 spaces for ' (deleted)' to be appended */
1623 0 : pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1624 0 : if (!pathname) {
1625 : audit_log_string(ab, "<no_memory>");
1626 0 : return;
1627 : }
1628 0 : p = d_path(path, pathname, PATH_MAX+11);
1629 0 : if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1630 : /* FIXME: can we save some information here? */
1631 : audit_log_string(ab, "<too_long>");
1632 : } else
1633 0 : audit_log_untrustedstring(ab, p);
1634 0 : kfree(pathname);
1635 : }
1636 :
1637 0 : void audit_log_session_info(struct audit_buffer *ab)
1638 : {
1639 : unsigned int sessionid = audit_get_sessionid(current);
1640 : uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1641 :
1642 0 : audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
1643 0 : }
1644 :
1645 0 : void audit_log_key(struct audit_buffer *ab, char *key)
1646 : {
1647 0 : audit_log_format(ab, " key=");
1648 0 : if (key)
1649 0 : audit_log_untrustedstring(ab, key);
1650 : else
1651 0 : audit_log_format(ab, "(null)");
1652 0 : }
1653 :
1654 0 : void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
1655 : {
1656 : int i;
1657 :
1658 0 : audit_log_format(ab, " %s=", prefix);
1659 0 : CAP_FOR_EACH_U32(i) {
1660 0 : audit_log_format(ab, "%08x",
1661 0 : cap->cap[CAP_LAST_U32 - i]);
1662 : }
1663 0 : }
1664 :
1665 0 : static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
1666 : {
1667 0 : kernel_cap_t *perm = &name->fcap.permitted;
1668 0 : kernel_cap_t *inh = &name->fcap.inheritable;
1669 : int log = 0;
1670 :
1671 0 : if (!cap_isclear(*perm)) {
1672 0 : audit_log_cap(ab, "cap_fp", perm);
1673 : log = 1;
1674 : }
1675 0 : if (!cap_isclear(*inh)) {
1676 0 : audit_log_cap(ab, "cap_fi", inh);
1677 : log = 1;
1678 : }
1679 :
1680 0 : if (log)
1681 0 : audit_log_format(ab, " cap_fe=%d cap_fver=%x",
1682 : name->fcap.fE, name->fcap_ver);
1683 0 : }
1684 :
1685 : static inline int audit_copy_fcaps(struct audit_names *name,
1686 : const struct dentry *dentry)
1687 : {
1688 : struct cpu_vfs_cap_data caps;
1689 : int rc;
1690 :
1691 0 : if (!dentry)
1692 : return 0;
1693 :
1694 0 : rc = get_vfs_caps_from_disk(dentry, &caps);
1695 0 : if (rc)
1696 : return rc;
1697 :
1698 0 : name->fcap.permitted = caps.permitted;
1699 0 : name->fcap.inheritable = caps.inheritable;
1700 0 : name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
1701 0 : name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >>
1702 : VFS_CAP_REVISION_SHIFT;
1703 :
1704 : return 0;
1705 : }
1706 :
1707 : /* Copy inode data into an audit_names. */
1708 0 : void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
1709 : const struct inode *inode)
1710 : {
1711 0 : name->ino = inode->i_ino;
1712 0 : name->dev = inode->i_sb->s_dev;
1713 0 : name->mode = inode->i_mode;
1714 0 : name->uid = inode->i_uid;
1715 0 : name->gid = inode->i_gid;
1716 0 : name->rdev = inode->i_rdev;
1717 : security_inode_getsecid(inode, &name->osid);
1718 : audit_copy_fcaps(name, dentry);
1719 0 : }
1720 :
1721 : /**
1722 : * audit_log_name - produce AUDIT_PATH record from struct audit_names
1723 : * @context: audit_context for the task
1724 : * @n: audit_names structure with reportable details
1725 : * @path: optional path to report instead of audit_names->name
1726 : * @record_num: record number to report when handling a list of names
1727 : * @call_panic: optional pointer to int that will be updated if secid fails
1728 : */
1729 0 : void audit_log_name(struct audit_context *context, struct audit_names *n,
1730 : struct path *path, int record_num, int *call_panic)
1731 : {
1732 : struct audit_buffer *ab;
1733 0 : ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
1734 0 : if (!ab)
1735 0 : return;
1736 :
1737 0 : audit_log_format(ab, "item=%d", record_num);
1738 :
1739 0 : if (path)
1740 0 : audit_log_d_path(ab, " name=", path);
1741 0 : else if (n->name) {
1742 0 : switch (n->name_len) {
1743 : case AUDIT_NAME_FULL:
1744 : /* log the full path */
1745 0 : audit_log_format(ab, " name=");
1746 0 : audit_log_untrustedstring(ab, n->name->name);
1747 0 : break;
1748 : case 0:
1749 : /* name was specified as a relative path and the
1750 : * directory component is the cwd */
1751 0 : audit_log_d_path(ab, " name=", &context->pwd);
1752 0 : break;
1753 : default:
1754 : /* log the name's directory component */
1755 0 : audit_log_format(ab, " name=");
1756 0 : audit_log_n_untrustedstring(ab, n->name->name,
1757 0 : n->name_len);
1758 : }
1759 : } else
1760 0 : audit_log_format(ab, " name=(null)");
1761 :
1762 0 : if (n->ino != (unsigned long)-1) {
1763 0 : audit_log_format(ab, " inode=%lu"
1764 : " dev=%02x:%02x mode=%#ho"
1765 : " ouid=%u ogid=%u rdev=%02x:%02x",
1766 : n->ino,
1767 0 : MAJOR(n->dev),
1768 : MINOR(n->dev),
1769 0 : n->mode,
1770 : from_kuid(&init_user_ns, n->uid),
1771 : from_kgid(&init_user_ns, n->gid),
1772 0 : MAJOR(n->rdev),
1773 : MINOR(n->rdev));
1774 : }
1775 0 : if (n->osid != 0) {
1776 : char *ctx = NULL;
1777 : u32 len;
1778 : if (security_secid_to_secctx(
1779 : n->osid, &ctx, &len)) {
1780 0 : audit_log_format(ab, " osid=%u", n->osid);
1781 0 : if (call_panic)
1782 0 : *call_panic = 2;
1783 : } else {
1784 : audit_log_format(ab, " obj=%s", ctx);
1785 : security_release_secctx(ctx, len);
1786 : }
1787 : }
1788 :
1789 : /* log the audit_names record type */
1790 0 : audit_log_format(ab, " nametype=");
1791 0 : switch(n->type) {
1792 : case AUDIT_TYPE_NORMAL:
1793 0 : audit_log_format(ab, "NORMAL");
1794 0 : break;
1795 : case AUDIT_TYPE_PARENT:
1796 0 : audit_log_format(ab, "PARENT");
1797 0 : break;
1798 : case AUDIT_TYPE_CHILD_DELETE:
1799 0 : audit_log_format(ab, "DELETE");
1800 0 : break;
1801 : case AUDIT_TYPE_CHILD_CREATE:
1802 0 : audit_log_format(ab, "CREATE");
1803 0 : break;
1804 : default:
1805 0 : audit_log_format(ab, "UNKNOWN");
1806 0 : break;
1807 : }
1808 :
1809 0 : audit_log_fcaps(ab, n);
1810 0 : audit_log_end(ab);
1811 : }
1812 :
1813 0 : int audit_log_task_context(struct audit_buffer *ab)
1814 : {
1815 : char *ctx = NULL;
1816 : unsigned len;
1817 : int error;
1818 : u32 sid;
1819 :
1820 : security_task_getsecid(current, &sid);
1821 : if (!sid)
1822 : return 0;
1823 :
1824 : error = security_secid_to_secctx(sid, &ctx, &len);
1825 : if (error) {
1826 : if (error != -EINVAL)
1827 : goto error_path;
1828 : return 0;
1829 : }
1830 :
1831 : audit_log_format(ab, " subj=%s", ctx);
1832 : security_release_secctx(ctx, len);
1833 : return 0;
1834 :
1835 : error_path:
1836 : audit_panic("error in audit_log_task_context");
1837 : return error;
1838 : }
1839 : EXPORT_SYMBOL(audit_log_task_context);
1840 :
1841 0 : void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
1842 : {
1843 : const struct cred *cred;
1844 : char comm[sizeof(tsk->comm)];
1845 0 : struct mm_struct *mm = tsk->mm;
1846 : char *tty;
1847 :
1848 0 : if (!ab)
1849 0 : return;
1850 :
1851 : /* tsk == current */
1852 0 : cred = current_cred();
1853 :
1854 : spin_lock_irq(&tsk->sighand->siglock);
1855 0 : if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
1856 0 : tty = tsk->signal->tty->name;
1857 : else
1858 : tty = "(none)";
1859 : spin_unlock_irq(&tsk->sighand->siglock);
1860 :
1861 0 : audit_log_format(ab,
1862 : " ppid=%d pid=%d auid=%u uid=%u gid=%u"
1863 : " euid=%u suid=%u fsuid=%u"
1864 : " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
1865 : task_ppid_nr(tsk),
1866 : task_pid_nr(tsk),
1867 : from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
1868 : from_kuid(&init_user_ns, cred->uid),
1869 : from_kgid(&init_user_ns, cred->gid),
1870 : from_kuid(&init_user_ns, cred->euid),
1871 : from_kuid(&init_user_ns, cred->suid),
1872 : from_kuid(&init_user_ns, cred->fsuid),
1873 : from_kgid(&init_user_ns, cred->egid),
1874 : from_kgid(&init_user_ns, cred->sgid),
1875 : from_kgid(&init_user_ns, cred->fsgid),
1876 : tty, audit_get_sessionid(tsk));
1877 :
1878 0 : audit_log_format(ab, " comm=");
1879 0 : audit_log_untrustedstring(ab, get_task_comm(comm, tsk));
1880 :
1881 0 : if (mm) {
1882 0 : down_read(&mm->mmap_sem);
1883 0 : if (mm->exe_file)
1884 0 : audit_log_d_path(ab, " exe=", &mm->exe_file->f_path);
1885 0 : up_read(&mm->mmap_sem);
1886 : } else
1887 0 : audit_log_format(ab, " exe=(null)");
1888 : audit_log_task_context(ab);
1889 : }
1890 : EXPORT_SYMBOL(audit_log_task_info);
1891 :
1892 : /**
1893 : * audit_log_link_denied - report a link restriction denial
1894 : * @operation: specific link opreation
1895 : * @link: the path that triggered the restriction
1896 : */
1897 0 : void audit_log_link_denied(const char *operation, struct path *link)
1898 : {
1899 : struct audit_buffer *ab;
1900 : struct audit_names *name;
1901 :
1902 : name = kzalloc(sizeof(*name), GFP_NOFS);
1903 0 : if (!name)
1904 0 : return;
1905 :
1906 : /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
1907 0 : ab = audit_log_start(current->audit_context, GFP_KERNEL,
1908 : AUDIT_ANOM_LINK);
1909 0 : if (!ab)
1910 : goto out;
1911 0 : audit_log_format(ab, "op=%s", operation);
1912 0 : audit_log_task_info(ab, current);
1913 0 : audit_log_format(ab, " res=0");
1914 0 : audit_log_end(ab);
1915 :
1916 : /* Generate AUDIT_PATH record with object. */
1917 0 : name->type = AUDIT_TYPE_NORMAL;
1918 0 : audit_copy_inode(name, link->dentry, link->dentry->d_inode);
1919 0 : audit_log_name(current->audit_context, name, link, 0, NULL);
1920 : out:
1921 0 : kfree(name);
1922 : }
1923 :
1924 : /**
1925 : * audit_log_end - end one audit record
1926 : * @ab: the audit_buffer
1927 : *
1928 : * netlink_unicast() cannot be called inside an irq context because it blocks
1929 : * (last arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed
1930 : * on a queue and a tasklet is scheduled to remove them from the queue outside
1931 : * the irq context. May be called in any context.
1932 : */
1933 1 : void audit_log_end(struct audit_buffer *ab)
1934 : {
1935 1 : if (!ab)
1936 1 : return;
1937 1 : if (!audit_rate_check()) {
1938 0 : audit_log_lost("rate limit exceeded");
1939 : } else {
1940 1 : struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
1941 :
1942 1 : nlh->nlmsg_len = ab->skb->len;
1943 1 : kauditd_send_multicast_skb(ab->skb, ab->gfp_mask);
1944 :
1945 : /*
1946 : * The original kaudit unicast socket sends up messages with
1947 : * nlmsg_len set to the payload length rather than the entire
1948 : * message length. This breaks the standard set by netlink.
1949 : * The existing auditd daemon assumes this breakage. Fixing
1950 : * this would require co-ordinating a change in the established
1951 : * protocol between the kaudit kernel subsystem and the auditd
1952 : * userspace code.
1953 : */
1954 1 : nlh->nlmsg_len -= NLMSG_HDRLEN;
1955 :
1956 1 : if (audit_pid) {
1957 0 : skb_queue_tail(&audit_skb_queue, ab->skb);
1958 0 : wake_up_interruptible(&kauditd_wait);
1959 : } else {
1960 1 : audit_printk_skb(ab->skb);
1961 : }
1962 1 : ab->skb = NULL;
1963 : }
1964 1 : audit_buffer_free(ab);
1965 : }
1966 :
1967 : /**
1968 : * audit_log - Log an audit record
1969 : * @ctx: audit context
1970 : * @gfp_mask: type of allocation
1971 : * @type: audit message type
1972 : * @fmt: format string to use
1973 : * @...: variable parameters matching the format string
1974 : *
1975 : * This is a convenience function that calls audit_log_start,
1976 : * audit_log_vformat, and audit_log_end. It may be called
1977 : * in any context.
1978 : */
1979 1 : void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
1980 : const char *fmt, ...)
1981 : {
1982 : struct audit_buffer *ab;
1983 : va_list args;
1984 :
1985 1 : ab = audit_log_start(ctx, gfp_mask, type);
1986 1 : if (ab) {
1987 1 : va_start(args, fmt);
1988 1 : audit_log_vformat(ab, fmt, args);
1989 1 : va_end(args);
1990 1 : audit_log_end(ab);
1991 : }
1992 1 : }
1993 :
1994 : #ifdef CONFIG_SECURITY
1995 : /**
1996 : * audit_log_secctx - Converts and logs SELinux context
1997 : * @ab: audit_buffer
1998 : * @secid: security number
1999 : *
2000 : * This is a helper function that calls security_secid_to_secctx to convert
2001 : * secid to secctx and then adds the (converted) SELinux context to the audit
2002 : * log by calling audit_log_format, thus also preventing leak of internal secid
2003 : * to userspace. If secid cannot be converted audit_panic is called.
2004 : */
2005 : void audit_log_secctx(struct audit_buffer *ab, u32 secid)
2006 : {
2007 : u32 len;
2008 : char *secctx;
2009 :
2010 : if (security_secid_to_secctx(secid, &secctx, &len)) {
2011 : audit_panic("Cannot convert secid to context");
2012 : } else {
2013 : audit_log_format(ab, " obj=%s", secctx);
2014 : security_release_secctx(secctx, len);
2015 : }
2016 : }
2017 : EXPORT_SYMBOL(audit_log_secctx);
2018 : #endif
2019 :
2020 : EXPORT_SYMBOL(audit_log_start);
2021 : EXPORT_SYMBOL(audit_log_end);
2022 : EXPORT_SYMBOL(audit_log_format);
2023 : EXPORT_SYMBOL(audit_log);
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