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85c87212005-04-29 16:23:29 +01001/* audit.c -- Auditing support
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
3 * System-call specific features have moved to auditsc.c
4 *
Steve Grubb6a01b07f2007-01-19 14:39:55 -05005 * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 * 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 *
Ahmed S. Darwishd7a96f32008-03-01 22:01:11 +020024 * Goals: 1) Integrate fully with Security Modules.
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 * 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 *
85c87212005-04-29 16:23:29 +010041 * Example user-space utilities: http://people.redhat.com/sgrubb/audit/
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 */
43
44#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070045#include <asm/types.h>
Alan Cox715b49e2006-01-18 17:44:07 -080046#include <asm/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <linux/mm.h>
48#include <linux/module.h>
David Woodhouseb7d11252005-05-19 10:56:58 +010049#include <linux/err.h>
50#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
52#include <linux/audit.h>
53
54#include <net/sock.h>
Amy Griffis93315ed2006-02-07 12:05:27 -050055#include <net/netlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070056#include <linux/skbuff.h>
57#include <linux/netlink.h>
Amy Griffisf368c07d2006-04-07 16:55:56 -040058#include <linux/inotify.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080059#include <linux/freezer.h>
Miloslav Trmac522ed772007-07-15 23:40:56 -070060#include <linux/tty.h>
Darrel Goeddel3dc7e312006-03-10 18:14:06 -060061
62#include "audit.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Eric Parisa3f07112008-11-05 12:47:09 -050064/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 * (Initialization happens after skb_init is called.) */
Eric Parisa3f07112008-11-05 12:47:09 -050066#define AUDIT_DISABLED -1
67#define AUDIT_UNINITIALIZED 0
68#define AUDIT_INITIALIZED 1
Linus Torvalds1da177e2005-04-16 15:20:36 -070069static int audit_initialized;
70
Eric Paris1a6b9f22008-01-07 17:09:31 -050071#define AUDIT_OFF 0
72#define AUDIT_ON 1
73#define AUDIT_LOCKED 2
Linus Torvalds1da177e2005-04-16 15:20:36 -070074int audit_enabled;
Eric Parisb593d382008-01-08 17:38:31 -050075int audit_ever_enabled;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77/* Default state when kernel boots without any parameters. */
78static int audit_default;
79
80/* If auditing cannot proceed, audit_failure selects what happens. */
81static int audit_failure = AUDIT_FAIL_PRINTK;
82
Pavel Emelyanov75c03712008-03-20 15:39:41 -070083/*
84 * If audit records are to be written to the netlink socket, audit_pid
85 * contains the pid of the auditd process and audit_nlk_pid contains
86 * the pid to use to send netlink messages to that process.
87 */
Steve Grubbc2f0c7c2005-05-06 12:38:39 +010088int audit_pid;
Pavel Emelyanov75c03712008-03-20 15:39:41 -070089static int audit_nlk_pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Randy Dunlapb0dd25a2005-09-13 12:47:11 -070091/* If audit_rate_limit is non-zero, limit the rate of sending audit records
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 * to that number per second. This prevents DoS attacks, but results in
93 * audit records being dropped. */
94static int audit_rate_limit;
95
96/* Number of outstanding audit_buffers allowed. */
97static int audit_backlog_limit = 64;
David Woodhouseac4cec42005-07-02 14:08:48 +010098static int audit_backlog_wait_time = 60 * HZ;
99static int audit_backlog_wait_overflow = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100101/* The identity of the user shutting down the audit system. */
102uid_t audit_sig_uid = -1;
103pid_t audit_sig_pid = -1;
Al Viroe1396062006-05-25 10:19:47 -0400104u32 audit_sig_sid = 0;
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100105
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106/* Records can be lost in several ways:
107 0) [suppressed in audit_alloc]
108 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
109 2) out of memory in audit_log_move [alloc_skb]
110 3) suppressed due to audit_rate_limit
111 4) suppressed due to audit_backlog_limit
112*/
113static atomic_t audit_lost = ATOMIC_INIT(0);
114
115/* The netlink socket. */
116static struct sock *audit_sock;
117
Amy Griffisf368c07d2006-04-07 16:55:56 -0400118/* Hash for inode-based rules */
119struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
120
David Woodhouseb7d11252005-05-19 10:56:58 +0100121/* The audit_freelist is a list of pre-allocated audit buffers (if more
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
123 * being placed on the freelist). */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124static DEFINE_SPINLOCK(audit_freelist_lock);
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700125static int audit_freelist_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126static LIST_HEAD(audit_freelist);
127
David Woodhouseb7d11252005-05-19 10:56:58 +0100128static struct sk_buff_head audit_skb_queue;
Eric Parisf3d357b2008-04-18 10:02:28 -0400129/* queue of skbs to send to auditd when/if it comes back */
130static struct sk_buff_head audit_skb_hold_queue;
David Woodhouseb7d11252005-05-19 10:56:58 +0100131static struct task_struct *kauditd_task;
132static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100133static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Amy Griffisf368c07d2006-04-07 16:55:56 -0400135/* Serialize requests from userspace. */
Al Viro916d7572009-06-24 00:02:38 -0400136DEFINE_MUTEX(audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137
138/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
139 * audit records. Since printk uses a 1024 byte buffer, this buffer
140 * should be at least that large. */
141#define AUDIT_BUFSIZ 1024
142
143/* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
144 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
145#define AUDIT_MAXFREE (2*NR_CPUS)
146
147/* The audit_buffer is used when formatting an audit record. The caller
148 * locks briefly to get the record off the freelist or to allocate the
149 * buffer, and locks briefly to send the buffer to the netlink layer or
150 * to place it on a transmit queue. Multiple audit_buffers can be in
151 * use simultaneously. */
152struct audit_buffer {
153 struct list_head list;
Chris Wright8fc61152005-05-06 15:54:17 +0100154 struct sk_buff *skb; /* formatted skb ready to send */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 struct audit_context *ctx; /* NULL or associated context */
Al Viro9796fdd2005-10-21 03:22:03 -0400156 gfp_t gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157};
158
Eric Parisf09ac9d2008-04-18 10:11:04 -0400159struct audit_reply {
160 int pid;
161 struct sk_buff *skb;
162};
163
Steve Grubbc0404992005-05-13 18:17:42 +0100164static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
165{
Eric Paris50397bd2008-01-07 18:14:19 -0500166 if (ab) {
167 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
168 nlh->nlmsg_pid = pid;
169 }
Steve Grubbc0404992005-05-13 18:17:42 +0100170}
171
Dustin Kirkland8c8570f2005-11-03 17:15:16 +0000172void audit_panic(const char *message)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173{
174 switch (audit_failure)
175 {
176 case AUDIT_FAIL_SILENT:
177 break;
178 case AUDIT_FAIL_PRINTK:
Eric Paris320f1b12008-01-23 22:55:05 -0500179 if (printk_ratelimit())
180 printk(KERN_ERR "audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 break;
182 case AUDIT_FAIL_PANIC:
Eric Parisb29ee872008-02-21 15:53:05 -0500183 /* test audit_pid since printk is always losey, why bother? */
184 if (audit_pid)
185 panic("audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 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
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700219/**
220 * audit_log_lost - conditionally log lost audit message event
221 * @message: the message stating reason for lost audit message
222 *
223 * Emit at least 1 message per second, even if audit_rate_check is
224 * throttling.
225 * Always increment the lost messages counter.
226*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227void 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) {
Eric Paris320f1b12008-01-23 22:55:05 -0500250 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 audit_panic(message);
258 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259}
260
Eric Paris1a6b9f22008-01-07 17:09:31 -0500261static int audit_log_config_change(char *function_name, int new, int old,
Eric Paris25323862008-04-18 10:09:25 -0400262 uid_t loginuid, u32 sessionid, u32 sid,
263 int allow_changes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500265 struct audit_buffer *ab;
266 int rc = 0;
Steve Grubb6a01b07f2007-01-19 14:39:55 -0500267
Eric Paris1a6b9f22008-01-07 17:09:31 -0500268 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
Eric Paris25323862008-04-18 10:09:25 -0400269 audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
270 old, loginuid, sessionid);
Steve Grubbce29b682006-04-01 18:29:34 -0500271 if (sid) {
272 char *ctx = NULL;
273 u32 len;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500274
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200275 rc = security_secid_to_secctx(sid, &ctx, &len);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500276 if (rc) {
277 audit_log_format(ab, " sid=%u", sid);
278 allow_changes = 0; /* Something weird, deny request */
279 } else {
280 audit_log_format(ab, " subj=%s", ctx);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200281 security_release_secctx(ctx, len);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500282 }
Steve Grubb6a01b07f2007-01-19 14:39:55 -0500283 }
Eric Paris1a6b9f22008-01-07 17:09:31 -0500284 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,
Eric Paris25323862008-04-18 10:09:25 -0400290 int new, uid_t loginuid, u32 sessionid,
291 u32 sid)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500292{
293 int allow_changes, rc = 0, old = *to_change;
294
295 /* check if we are locked */
296 if (audit_enabled == AUDIT_LOCKED)
297 allow_changes = 0;
298 else
299 allow_changes = 1;
300
301 if (audit_enabled != AUDIT_OFF) {
Eric Paris25323862008-04-18 10:09:25 -0400302 rc = audit_log_config_change(function_name, new, old, loginuid,
303 sessionid, sid, allow_changes);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500304 if (rc)
305 allow_changes = 0;
306 }
Steve Grubb6a01b07f2007-01-19 14:39:55 -0500307
308 /* If we are allowed, make the change */
Eric Paris1a6b9f22008-01-07 17:09:31 -0500309 if (allow_changes == 1)
310 *to_change = new;
Steve Grubb6a01b07f2007-01-19 14:39:55 -0500311 /* Not allowed, update reason */
312 else if (rc == 0)
313 rc = -EPERM;
314 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315}
316
Eric Paris25323862008-04-18 10:09:25 -0400317static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid,
318 u32 sid)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500319{
320 return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
Eric Paris25323862008-04-18 10:09:25 -0400321 limit, loginuid, sessionid, sid);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500322}
323
Eric Paris25323862008-04-18 10:09:25 -0400324static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid,
325 u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500327 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
Eric Paris25323862008-04-18 10:09:25 -0400328 limit, loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329}
330
Eric Paris25323862008-04-18 10:09:25 -0400331static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332{
Eric Parisb593d382008-01-08 17:38:31 -0500333 int rc;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500334 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500336
Eric Parisb593d382008-01-08 17:38:31 -0500337 rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
Eric Paris25323862008-04-18 10:09:25 -0400338 loginuid, sessionid, sid);
Eric Parisb593d382008-01-08 17:38:31 -0500339
340 if (!rc)
341 audit_ever_enabled |= !!state;
342
343 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344}
345
Eric Paris25323862008-04-18 10:09:25 -0400346static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 if (state != AUDIT_FAIL_SILENT
349 && state != AUDIT_FAIL_PRINTK
350 && state != AUDIT_FAIL_PANIC)
351 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500352
Eric Paris1a6b9f22008-01-07 17:09:31 -0500353 return audit_do_config_change("audit_failure", &audit_failure, state,
Eric Paris25323862008-04-18 10:09:25 -0400354 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355}
356
Eric Parisf3d357b2008-04-18 10:02:28 -0400357/*
358 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
359 * already have been sent via prink/syslog and so if these messages are dropped
360 * it is not a huge concern since we already passed the audit_log_lost()
361 * notification and stuff. This is just nice to get audit messages during
362 * boot before auditd is running or messages generated while auditd is stopped.
363 * This only holds messages is audit_default is set, aka booting with audit=1
364 * or building your kernel that way.
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
Eric Paris038cbcf2009-06-11 14:31:35 -0400375/*
376 * For one reason or another this nlh isn't getting delivered to the userspace
377 * audit daemon, just send it to printk.
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
Eric Parisf3d357b2008-04-18 10:02:28 -0400394static void kauditd_send_skb(struct sk_buff *skb)
395{
396 int err;
397 /* take a reference in case we can't send it and we want to hold it */
398 skb_get(skb);
399 err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0);
400 if (err < 0) {
Adam Buchbinderc9404c92009-12-18 15:40:42 -0500401 BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
Eric Parisf3d357b2008-04-18 10:02:28 -0400402 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 /* we might get lucky and get this in the next auditd */
406 audit_hold_skb(skb);
407 } else
408 /* drop the extra reference if sent ok */
409 kfree_skb(skb);
410}
411
Adrian Bunk97a41e22006-01-08 01:02:17 -0800412static int kauditd_thread(void *dummy)
David Woodhouseb7d11252005-05-19 10:56:58 +0100413{
414 struct sk_buff *skb;
415
Rafael J. Wysocki83144182007-07-17 04:03:35 -0700416 set_freezable();
Andrew Morton4899b8b2006-10-06 00:43:48 -0700417 while (!kthread_should_stop()) {
Eric Parisf3d357b2008-04-18 10:02:28 -0400418 /*
419 * if auditd just started drain the queue of messages already
420 * sent to syslog/printk. remember loss here is ok. we already
421 * called audit_log_lost() if it didn't go out normally. so the
422 * race between the skb_dequeue and the next check for audit_pid
423 * doesn't matter.
424 *
425 * if you ever find kauditd to be too slow we can get a perf win
426 * by doing our own locking and keeping better track if there
427 * are messages in this queue. I don't see the need now, but
428 * in 5 years when I want to play with this again I'll see this
429 * note and still have no friggin idea what i'm thinking today.
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
David Woodhouseb7d11252005-05-19 10:56:58 +0100441 skb = skb_dequeue(&audit_skb_queue);
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100442 wake_up(&audit_backlog_wait);
David Woodhouseb7d11252005-05-19 10:56:58 +0100443 if (skb) {
Eric Parisf3d357b2008-04-18 10:02:28 -0400444 if (audit_pid)
445 kauditd_send_skb(skb);
Eric Paris038cbcf2009-06-11 14:31:35 -0400446 else
447 audit_printk_skb(skb);
David Woodhouseb7d11252005-05-19 10:56:58 +0100448 } else {
449 DECLARE_WAITQUEUE(wait, current);
450 set_current_state(TASK_INTERRUPTIBLE);
451 add_wait_queue(&kauditd_wait, &wait);
452
Pierre Ossman7a4ae742005-12-12 00:37:22 -0800453 if (!skb_queue_len(&audit_skb_queue)) {
454 try_to_freeze();
David Woodhouseb7d11252005-05-19 10:56:58 +0100455 schedule();
Pierre Ossman7a4ae742005-12-12 00:37:22 -0800456 }
David Woodhouseb7d11252005-05-19 10:56:58 +0100457
458 __set_current_state(TASK_RUNNING);
459 remove_wait_queue(&kauditd_wait, &wait);
460 }
461 }
Andrew Morton4899b8b2006-10-06 00:43:48 -0700462 return 0;
David Woodhouseb7d11252005-05-19 10:56:58 +0100463}
464
Eric Paris25323862008-04-18 10:09:25 -0400465static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid)
Miloslav Trmac522ed772007-07-15 23:40:56 -0700466{
467 struct task_struct *tsk;
468 int err;
469
470 read_lock(&tasklist_lock);
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700471 tsk = find_task_by_vpid(pid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700472 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
Eric Paris25323862008-04-18 10:09:25 -0400484 tty_audit_push_task(tsk, loginuid, sessionid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700485out:
486 read_unlock(&tasklist_lock);
487 return err;
488}
489
Al Viro9044e6b2006-05-22 01:09:24 -0400490int 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 /* wait for parent to finish and send an ACK */
Amy Griffisf368c07d2006-04-07 16:55:56 -0400497 mutex_lock(&audit_cmd_mutex);
498 mutex_unlock(&audit_cmd_mutex);
Al Viro9044e6b2006-05-22 01:09:24 -0400499
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;
Al Viro9044e6b2006-05-22 01:09:24 -0400513 void *data;
514 int flags = multi ? NLM_F_MULTI : 0;
515 int t = done ? NLMSG_DONE : type;
516
Eric Parisee080e62009-06-11 14:31:35 -0400517 skb = nlmsg_new(size, GFP_KERNEL);
Al Viro9044e6b2006-05-22 01:09:24 -0400518 if (!skb)
519 return NULL;
520
Eric Parisee080e62009-06-11 14:31:35 -0400521 nlh = NLMSG_NEW(skb, pid, seq, t, size, flags);
522 data = NLMSG_DATA(nlh);
Al Viro9044e6b2006-05-22 01:09:24 -0400523 memcpy(data, payload, size);
524 return skb;
525
Eric Parisee080e62009-06-11 14:31:35 -0400526nlmsg_failure: /* Used by NLMSG_NEW */
Al Viro9044e6b2006-05-22 01:09:24 -0400527 if (skb)
528 kfree_skb(skb);
529 return NULL;
530}
531
Eric Parisf09ac9d2008-04-18 10:11:04 -0400532static 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 /* Ignore failure. It'll only happen if the sender goes away,
540 because our timeout is set to infinite. */
541 netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
542 kfree(reply);
543 return 0;
544}
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700545/**
546 * audit_send_reply - send an audit reply message via netlink
547 * @pid: process id to send reply to
548 * @seq: sequence number
549 * @type: audit message type
550 * @done: done (last) flag
551 * @multi: multi-part message flag
552 * @payload: payload data
553 * @size: payload size
554 *
555 * Allocates an skb, builds the netlink message, and sends it to the pid.
556 * No failure notifications.
557 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558void audit_send_reply(int pid, int seq, int type, int done, int multi,
559 void *payload, int size)
560{
Eric Parisf09ac9d2008-04-18 10:11:04 -0400561 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
Al Viro9044e6b2006-05-22 01:09:24 -0400569 skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 if (!skb)
Andrew Mortonfcaf1eb2008-05-14 16:11:48 -0700571 goto out;
Eric Parisf09ac9d2008-04-18 10:11:04 -0400572
573 reply->pid = pid;
574 reply->skb = skb;
575
576 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
Andrew Mortonfcaf1eb2008-05-14 16:11:48 -0700577 if (!IS_ERR(tsk))
578 return;
579 kfree_skb(skb);
580out:
581 kfree(reply);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582}
583
584/*
585 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
586 * control messages.
587 */
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700588static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589{
590 int err = 0;
591
592 switch (msg_type) {
593 case AUDIT_GET:
594 case AUDIT_LIST:
Amy Griffis93315ed2006-02-07 12:05:27 -0500595 case AUDIT_LIST_RULES:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 case AUDIT_SET:
597 case AUDIT_ADD:
Amy Griffis93315ed2006-02-07 12:05:27 -0500598 case AUDIT_ADD_RULE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 case AUDIT_DEL:
Amy Griffis93315ed2006-02-07 12:05:27 -0500600 case AUDIT_DEL_RULE:
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100601 case AUDIT_SIGNAL_INFO:
Miloslav Trmac522ed772007-07-15 23:40:56 -0700602 case AUDIT_TTY_GET:
603 case AUDIT_TTY_SET:
Al Viro74c3cbe2007-07-22 08:04:18 -0400604 case AUDIT_TRIM:
605 case AUDIT_MAKE_EQUIV:
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700606 if (security_netlink_recv(skb, CAP_AUDIT_CONTROL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 err = -EPERM;
608 break;
Steve Grubb05474102005-05-21 00:18:37 +0100609 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700610 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
611 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700612 if (security_netlink_recv(skb, CAP_AUDIT_WRITE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 err = -EPERM;
614 break;
615 default: /* bad msg */
616 err = -EINVAL;
617 }
618
619 return err;
620}
621
Eric Paris50397bd2008-01-07 18:14:19 -0500622static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
Eric Paris25323862008-04-18 10:09:25 -0400623 u32 pid, u32 uid, uid_t auid, u32 ses,
624 u32 sid)
Eric Paris50397bd2008-01-07 18:14:19 -0500625{
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);
Eric Paris25323862008-04-18 10:09:25 -0400636 audit_log_format(*ab, "user pid=%d uid=%u auid=%u ses=%u",
637 pid, uid, auid, ses);
Eric Paris50397bd2008-01-07 18:14:19 -0500638 if (sid) {
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200639 rc = security_secid_to_secctx(sid, &ctx, &len);
Eric Paris50397bd2008-01-07 18:14:19 -0500640 if (rc)
641 audit_log_format(*ab, " ssid=%u", sid);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200642 else {
Eric Paris50397bd2008-01-07 18:14:19 -0500643 audit_log_format(*ab, " subj=%s", ctx);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200644 security_release_secctx(ctx, len);
645 }
Eric Paris50397bd2008-01-07 18:14:19 -0500646 }
647
648 return rc;
649}
650
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
652{
Steve Grubbe7c34972006-04-03 09:08:13 -0400653 u32 uid, pid, seq, sid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 void *data;
655 struct audit_status *status_get, status_set;
656 int err;
Steve Grubbc0404992005-05-13 18:17:42 +0100657 struct audit_buffer *ab;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 u16 msg_type = nlh->nlmsg_type;
Serge Hallync94c2572005-04-29 16:27:17 +0100659 uid_t loginuid; /* loginuid of sender */
Eric Paris25323862008-04-18 10:09:25 -0400660 u32 sessionid;
Al Viroe1396062006-05-25 10:19:47 -0400661 struct audit_sig_info *sig_data;
Eric Paris50397bd2008-01-07 18:14:19 -0500662 char *ctx = NULL;
Al Viroe1396062006-05-25 10:19:47 -0400663 u32 len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700665 err = audit_netlink_ok(skb, msg_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 if (err)
667 return err;
668
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700669 /* As soon as there's any sign of userspace auditd,
670 * start kauditd to talk to it */
David Woodhouseb7d11252005-05-19 10:56:58 +0100671 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 pid = NETLINK_CREDS(skb)->pid;
680 uid = NETLINK_CREDS(skb)->uid;
Serge Hallync94c2572005-04-29 16:27:17 +0100681 loginuid = NETLINK_CB(skb).loginuid;
Eric Paris25323862008-04-18 10:09:25 -0400682 sessionid = NETLINK_CB(skb).sessionid;
Steve Grubbe7c34972006-04-03 09:08:13 -0400683 sid = NETLINK_CB(skb).sid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 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);
David Woodhouseb7d11252005-05-19 10:56:58 +0100695 status_set.backlog = skb_queue_len(&audit_skb_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 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) {
Steve Grubbce29b682006-04-01 18:29:34 -0500704 err = audit_set_enabled(status_get->enabled,
Eric Paris25323862008-04-18 10:09:25 -0400705 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800706 if (err < 0)
707 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 }
709 if (status_get->mask & AUDIT_STATUS_FAILURE) {
Steve Grubbce29b682006-04-01 18:29:34 -0500710 err = audit_set_failure(status_get->failure,
Eric Paris25323862008-04-18 10:09:25 -0400711 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800712 if (err < 0)
713 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 }
715 if (status_get->mask & AUDIT_STATUS_PID) {
Eric Paris1a6b9f22008-01-07 17:09:31 -0500716 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,
Eric Paris25323862008-04-18 10:09:25 -0400721 sessionid, sid, 1);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500722
723 audit_pid = new_pid;
Pavel Emelyanov75c03712008-03-20 15:39:41 -0700724 audit_nlk_pid = NETLINK_CB(skb).pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 }
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800726 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
Serge E. Hallyn5d136a02006-04-27 16:45:14 -0500727 err = audit_set_rate_limit(status_get->rate_limit,
Eric Paris25323862008-04-18 10:09:25 -0400728 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800729 if (err < 0)
730 return err;
731 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
Serge E. Hallyn5d136a02006-04-27 16:45:14 -0500733 err = audit_set_backlog_limit(status_get->backlog_limit,
Eric Paris25323862008-04-18 10:09:25 -0400734 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 break;
Steve Grubb05474102005-05-21 00:18:37 +0100736 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700737 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
738 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
David Woodhouse4a4cd632005-06-22 14:56:47 +0100739 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
740 return 0;
David Woodhouse0f45aa12005-06-19 19:35:50 +0100741
Peng Haitaod8de7242008-05-20 09:13:02 +0800742 err = audit_filter_user(&NETLINK_CB(skb));
David Woodhouse4a4cd632005-06-22 14:56:47 +0100743 if (err == 1) {
744 err = 0;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700745 if (msg_type == AUDIT_USER_TTY) {
Eric Paris25323862008-04-18 10:09:25 -0400746 err = audit_prepare_user_tty(pid, loginuid,
747 sessionid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700748 if (err)
749 break;
750 }
Eric Paris50397bd2008-01-07 18:14:19 -0500751 audit_log_common_recv_msg(&ab, msg_type, pid, uid,
Eric Paris25323862008-04-18 10:09:25 -0400752 loginuid, sessionid, sid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700753
Eric Paris50397bd2008-01-07 18:14:19 -0500754 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);
Miloslav Trmac55ad2f82009-03-19 09:52:47 -0400762 if (size > 0 &&
763 ((unsigned char *)data)[size - 1] == '\0')
764 size--;
Eric Parisb556f8a2008-04-18 10:12:59 -0400765 audit_log_n_untrustedstring(ab, data, size);
David Woodhouse4a4cd632005-06-22 14:56:47 +0100766 }
Eric Paris50397bd2008-01-07 18:14:19 -0500767 audit_set_pid(ab, pid);
768 audit_log_end(ab);
David Woodhouse0f45aa12005-06-19 19:35:50 +0100769 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 break;
771 case AUDIT_ADD:
772 case AUDIT_DEL:
Amy Griffis93315ed2006-02-07 12:05:27 -0500773 if (nlmsg_len(nlh) < sizeof(struct audit_rule))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500775 if (audit_enabled == AUDIT_LOCKED) {
Eric Paris50397bd2008-01-07 18:14:19 -0500776 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400777 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500778
779 audit_log_format(ab, " audit_enabled=%d res=0",
780 audit_enabled);
781 audit_log_end(ab);
Steve Grubb6a01b07f2007-01-19 14:39:55 -0500782 return -EPERM;
783 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 /* fallthrough */
785 case AUDIT_LIST:
Peng Haitao13d5ef92008-05-16 10:15:04 +0800786 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
Amy Griffis93315ed2006-02-07 12:05:27 -0500787 uid, seq, data, nlmsg_len(nlh),
Eric Paris25323862008-04-18 10:09:25 -0400788 loginuid, sessionid, sid);
Amy Griffis93315ed2006-02-07 12:05:27 -0500789 break;
790 case AUDIT_ADD_RULE:
791 case AUDIT_DEL_RULE:
792 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
793 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500794 if (audit_enabled == AUDIT_LOCKED) {
Eric Paris50397bd2008-01-07 18:14:19 -0500795 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400796 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500797
798 audit_log_format(ab, " audit_enabled=%d res=0",
799 audit_enabled);
800 audit_log_end(ab);
Steve Grubb6a01b07f2007-01-19 14:39:55 -0500801 return -EPERM;
802 }
Amy Griffis93315ed2006-02-07 12:05:27 -0500803 /* fallthrough */
804 case AUDIT_LIST_RULES:
Peng Haitao13d5ef92008-05-16 10:15:04 +0800805 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
Amy Griffis93315ed2006-02-07 12:05:27 -0500806 uid, seq, data, nlmsg_len(nlh),
Eric Paris25323862008-04-18 10:09:25 -0400807 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 break;
Al Viro74c3cbe2007-07-22 08:04:18 -0400809 case AUDIT_TRIM:
810 audit_trim_trees();
Eric Paris50397bd2008-01-07 18:14:19 -0500811
812 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400813 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500814
Al Viro74c3cbe2007-07-22 08:04:18 -0400815 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];
Harvey Harrison7719e432008-04-27 02:39:56 -0700821 size_t msglen = nlmsg_len(nlh);
Al Viro74c3cbe2007-07-22 08:04:18 -0400822 char *old, *new;
823
824 err = -EINVAL;
Harvey Harrison7719e432008-04-27 02:39:56 -0700825 if (msglen < 2 * sizeof(u32))
Al Viro74c3cbe2007-07-22 08:04:18 -0400826 break;
827 memcpy(sizes, bufp, 2 * sizeof(u32));
828 bufp += 2 * sizeof(u32);
Harvey Harrison7719e432008-04-27 02:39:56 -0700829 msglen -= 2 * sizeof(u32);
830 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
Al Viro74c3cbe2007-07-22 08:04:18 -0400831 if (IS_ERR(old)) {
832 err = PTR_ERR(old);
833 break;
834 }
Harvey Harrison7719e432008-04-27 02:39:56 -0700835 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
Al Viro74c3cbe2007-07-22 08:04:18 -0400836 if (IS_ERR(new)) {
837 err = PTR_ERR(new);
838 kfree(old);
839 break;
840 }
841 /* OK, here comes... */
842 err = audit_tag_tree(old, new);
843
Eric Paris50397bd2008-01-07 18:14:19 -0500844 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400845 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500846
Al Viro74c3cbe2007-07-22 08:04:18 -0400847 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 }
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100857 case AUDIT_SIGNAL_INFO:
Eric Paris939cbf22009-09-23 13:46:00 -0400858 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 }
Al Viroe1396062006-05-25 10:19:47 -0400864 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
865 if (!sig_data) {
Eric Paris939cbf22009-09-23 13:46:00 -0400866 if (audit_sig_sid)
867 security_release_secctx(ctx, len);
Al Viroe1396062006-05-25 10:19:47 -0400868 return -ENOMEM;
869 }
870 sig_data->uid = audit_sig_uid;
871 sig_data->pid = audit_sig_pid;
Eric Paris939cbf22009-09-23 13:46:00 -0400872 if (audit_sig_sid) {
873 memcpy(sig_data->ctx, ctx, len);
874 security_release_secctx(ctx, len);
875 }
Daniel Walker5600b892007-10-18 03:06:10 -0700876 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
Al Viroe1396062006-05-25 10:19:47 -0400877 0, 0, sig_data, sizeof(*sig_data) + len);
878 kfree(sig_data);
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100879 break;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700880 case AUDIT_TTY_GET: {
881 struct audit_tty_status s;
882 struct task_struct *tsk;
883
884 read_lock(&tasklist_lock);
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700885 tsk = find_task_by_vpid(pid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700886 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);
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700908 tsk = find_task_by_vpid(pid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700909 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 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 default:
920 err = -EINVAL;
921 break;
922 }
923
924 return err < 0 ? err : 0;
925}
926
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700927/*
Eric Parisea7ae602009-06-11 14:31:35 -0400928 * Get message from skb. Each message is processed by audit_receive_msg.
929 * Malformed skbs with wrong length are discarded silently.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700930 */
Herbert Xu2a0a6eb2005-05-03 14:55:09 -0700931static void audit_receive_skb(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932{
Eric Parisea7ae602009-06-11 14:31:35 -0400933 struct nlmsghdr *nlh;
934 /*
935 * len MUST be signed for NLMSG_NEXT to be able to dec it below 0
936 * if the nlmsg_len was not aligned
937 */
938 int len;
939 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940
Eric Parisea7ae602009-06-11 14:31:35 -0400941 nlh = nlmsg_hdr(skb);
942 len = skb->len;
943
944 while (NLMSG_OK(nlh, len)) {
945 err = audit_receive_msg(skb, nlh);
946 /* if err or if this message says it wants a response */
947 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948 netlink_ack(skb, nlh, err);
Eric Parisea7ae602009-06-11 14:31:35 -0400949
950 nlh = NLMSG_NEXT(nlh, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952}
953
954/* Receive messages from netlink socket. */
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700955static void audit_receive(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956{
Amy Griffisf368c07d2006-04-07 16:55:56 -0400957 mutex_lock(&audit_cmd_mutex);
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700958 audit_receive_skb(skb);
Amy Griffisf368c07d2006-04-07 16:55:56 -0400959 mutex_unlock(&audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960}
961
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962/* Initialize audit support at boot time. */
963static int __init audit_init(void)
964{
Amy Griffisf368c07d2006-04-07 16:55:56 -0400965 int i;
Amy Griffisf368c07d2006-04-07 16:55:56 -0400966
Eric Parisa3f07112008-11-05 12:47:09 -0500967 if (audit_initialized == AUDIT_DISABLED)
968 return 0;
969
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970 printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
971 audit_default ? "enabled" : "disabled");
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200972 audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, 0,
973 audit_receive, NULL, THIS_MODULE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 if (!audit_sock)
975 audit_panic("cannot initialize netlink socket");
Amy Griffis71e1c782006-03-06 22:40:05 -0500976 else
977 audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978
David Woodhouseb7d11252005-05-19 10:56:58 +0100979 skb_queue_head_init(&audit_skb_queue);
Eric Parisf3d357b2008-04-18 10:02:28 -0400980 skb_queue_head_init(&audit_skb_hold_queue);
Eric Parisa3f07112008-11-05 12:47:09 -0500981 audit_initialized = AUDIT_INITIALIZED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 audit_enabled = audit_default;
Eric Parisb593d382008-01-08 17:38:31 -0500983 audit_ever_enabled |= !!audit_default;
Darrel Goeddel3dc7e312006-03-10 18:14:06 -0600984
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100985 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
Amy Griffisf368c07d2006-04-07 16:55:56 -0400986
Amy Griffisf368c07d2006-04-07 16:55:56 -0400987 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
988 INIT_LIST_HEAD(&audit_inode_hash[i]);
Amy Griffisf368c07d2006-04-07 16:55:56 -0400989
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 return 0;
991}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992__initcall(audit_init);
993
994/* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
995static int __init audit_enable(char *str)
996{
997 audit_default = !!simple_strtol(str, NULL, 0);
Eric Parisa3f07112008-11-05 12:47:09 -0500998 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) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004 audit_enabled = audit_default;
Eric Parisb593d382008-01-08 17:38:31 -05001005 audit_ever_enabled |= !!audit_default;
Eric Parisa3f07112008-11-05 12:47:09 -05001006 } else if (audit_initialized == AUDIT_UNINITIALIZED) {
1007 printk(" (after initialization)");
1008 } else {
1009 printk(" (until reboot)");
Eric Parisb593d382008-01-08 17:38:31 -05001010 }
Eric Parisa3f07112008-11-05 12:47:09 -05001011 printk("\n");
1012
OGAWA Hirofumi9b410462006-03-31 02:30:33 -08001013 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014}
1015
1016__setup("audit=", audit_enable);
1017
Chris Wright16e19042005-05-06 15:53:34 +01001018static void audit_buffer_free(struct audit_buffer *ab)
1019{
1020 unsigned long flags;
1021
Chris Wright8fc61152005-05-06 15:54:17 +01001022 if (!ab)
1023 return;
1024
Chris Wright5ac52f32005-05-06 15:54:53 +01001025 if (ab->skb)
1026 kfree_skb(ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001027
Chris Wright16e19042005-05-06 15:53:34 +01001028 spin_lock_irqsave(&audit_freelist_lock, flags);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001029 if (audit_freelist_count > AUDIT_MAXFREE)
Chris Wright16e19042005-05-06 15:53:34 +01001030 kfree(ab);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001031 else {
1032 audit_freelist_count++;
Chris Wright16e19042005-05-06 15:53:34 +01001033 list_add(&ab->list, &audit_freelist);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001034 }
Chris Wright16e19042005-05-06 15:53:34 +01001035 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1036}
1037
Steve Grubbc0404992005-05-13 18:17:42 +01001038static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
Al Virodd0fc662005-10-07 07:46:04 +01001039 gfp_t gfp_mask, int type)
Chris Wright16e19042005-05-06 15:53:34 +01001040{
1041 unsigned long flags;
1042 struct audit_buffer *ab = NULL;
Steve Grubbc0404992005-05-13 18:17:42 +01001043 struct nlmsghdr *nlh;
Chris Wright16e19042005-05-06 15:53:34 +01001044
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) {
David Woodhouse4332bdd2005-05-06 15:59:57 +01001055 ab = kmalloc(sizeof(*ab), gfp_mask);
Chris Wright16e19042005-05-06 15:53:34 +01001056 if (!ab)
Chris Wright8fc61152005-05-06 15:54:17 +01001057 goto err;
Chris Wright16e19042005-05-06 15:53:34 +01001058 }
Chris Wright8fc61152005-05-06 15:54:17 +01001059
David Woodhouseb7d11252005-05-19 10:56:58 +01001060 ab->ctx = ctx;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001061 ab->gfp_mask = gfp_mask;
Eric Parisee080e62009-06-11 14:31:35 -04001062
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
Chris Wright16e19042005-05-06 15:53:34 +01001069 return ab;
Eric Parisee080e62009-06-11 14:31:35 -04001070
1071nlmsg_failure: /* Used by NLMSG_NEW */
1072 kfree_skb(ab->skb);
1073 ab->skb = NULL;
Chris Wright8fc61152005-05-06 15:54:17 +01001074err:
1075 audit_buffer_free(ab);
1076 return NULL;
Chris Wright16e19042005-05-06 15:53:34 +01001077}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001079/**
1080 * audit_serial - compute a serial number for the audit record
1081 *
1082 * Compute a serial number for the audit record. Audit records are
David Woodhousebfb44962005-05-21 21:08:09 +01001083 * written to user-space as soon as they are generated, so a complete
1084 * audit record may be written in several pieces. The timestamp of the
1085 * record and this serial number are used by the user-space tools to
1086 * determine which pieces belong to the same audit record. The
1087 * (timestamp,serial) tuple is unique for each syscall and is live from
1088 * syscall entry to syscall exit.
1089 *
David Woodhousebfb44962005-05-21 21:08:09 +01001090 * NOTE: Another possibility is to store the formatted records off the
1091 * audit context (for those records that have a context), and emit them
1092 * all at syscall exit. However, this could delay the reporting of
1093 * significant errors until syscall exit (or never, if the system
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001094 * halts).
1095 */
David Woodhousebfb44962005-05-21 21:08:09 +01001096unsigned int audit_serial(void)
1097{
Ingo Molnar34af9462006-06-27 02:53:55 -07001098 static DEFINE_SPINLOCK(serial_lock);
David Woodhoused5b454f2005-07-15 12:56:03 +01001099 static unsigned int serial = 0;
David Woodhousebfb44962005-05-21 21:08:09 +01001100
David Woodhoused5b454f2005-07-15 12:56:03 +01001101 unsigned long flags;
1102 unsigned int ret;
David Woodhousebfb44962005-05-21 21:08:09 +01001103
David Woodhoused5b454f2005-07-15 12:56:03 +01001104 spin_lock_irqsave(&serial_lock, flags);
David Woodhousebfb44962005-05-21 21:08:09 +01001105 do {
David Woodhousece625a82005-07-18 14:24:46 -04001106 ret = ++serial;
1107 } while (unlikely(!ret));
David Woodhoused5b454f2005-07-15 12:56:03 +01001108 spin_unlock_irqrestore(&serial_lock, flags);
David Woodhousebfb44962005-05-21 21:08:09 +01001109
David Woodhoused5b454f2005-07-15 12:56:03 +01001110 return ret;
David Woodhousebfb44962005-05-21 21:08:09 +01001111}
1112
Daniel Walker5600b892007-10-18 03:06:10 -07001113static inline void audit_get_stamp(struct audit_context *ctx,
David Woodhousebfb44962005-05-21 21:08:09 +01001114 struct timespec *t, unsigned int *serial)
1115{
Al Viro48887e62008-12-06 01:05:50 -05001116 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
David Woodhousebfb44962005-05-21 21:08:09 +01001117 *t = CURRENT_TIME;
1118 *serial = audit_serial();
1119 }
1120}
1121
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122/* Obtain an audit buffer. This routine does locking to obtain the
1123 * audit buffer, but then no locking is required for calls to
1124 * audit_log_*format. If the tsk is a task that is currently in a
1125 * syscall, then the syscall is marked as auditable and an audit record
1126 * will be written at syscall exit. If there is no associated task, tsk
1127 * should be NULL. */
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001128
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001129/**
1130 * audit_log_start - obtain an audit buffer
1131 * @ctx: audit_context (may be NULL)
1132 * @gfp_mask: type of allocation
1133 * @type: audit message type
1134 *
1135 * Returns audit_buffer pointer on success or NULL on error.
1136 *
1137 * Obtain an audit buffer. This routine does locking to obtain the
1138 * audit buffer, but then no locking is required for calls to
1139 * audit_log_*format. If the task (ctx) is a task that is currently in a
1140 * syscall, then the syscall is marked as auditable and an audit record
1141 * will be written at syscall exit. If there is no associated task, then
1142 * task context (ctx) should be NULL.
1143 */
Al Viro9796fdd2005-10-21 03:22:03 -04001144struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001145 int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146{
1147 struct audit_buffer *ab = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148 struct timespec t;
Andrew Mortonef00be02008-01-10 11:02:39 -08001149 unsigned int uninitialized_var(serial);
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001150 int reserve;
David Woodhouseac4cec42005-07-02 14:08:48 +01001151 unsigned long timeout_start = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152
Eric Parisa3f07112008-11-05 12:47:09 -05001153 if (audit_initialized != AUDIT_INITIALIZED)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 return NULL;
1155
Dustin Kirklandc8edc802005-11-03 16:12:36 +00001156 if (unlikely(audit_filter_type(type)))
1157 return NULL;
1158
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001159 if (gfp_mask & __GFP_WAIT)
1160 reserve = 0;
1161 else
Daniel Walker5600b892007-10-18 03:06:10 -07001162 reserve = 5; /* Allow atomic callers to go up to five
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001163 entries over the normal backlog limit */
1164
1165 while (audit_backlog_limit
1166 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
David Woodhouseac4cec42005-07-02 14:08:48 +01001167 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time
1168 && time_before(jiffies, timeout_start + audit_backlog_wait_time)) {
1169
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001170 /* Wait for auditd to drain the queue a little */
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)
David Woodhouseac4cec42005-07-02 14:08:48 +01001177 schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies);
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001178
1179 __set_current_state(TASK_RUNNING);
1180 remove_wait_queue(&audit_backlog_wait, &wait);
David Woodhouseac4cec42005-07-02 14:08:48 +01001181 continue;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001182 }
Eric Paris320f1b12008-01-23 22:55:05 -05001183 if (audit_rate_check() && printk_ratelimit())
David Woodhousefb19b4c2005-05-19 14:55:56 +01001184 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");
David Woodhouseac4cec42005-07-02 14:08:48 +01001190 audit_backlog_wait_time = audit_backlog_wait_overflow;
1191 wake_up(&audit_backlog_wait);
David Woodhousefb19b4c2005-05-19 14:55:56 +01001192 return NULL;
1193 }
1194
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001195 ab = audit_buffer_alloc(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196 if (!ab) {
1197 audit_log_lost("out of memory in audit_log_start");
1198 return NULL;
1199 }
1200
David Woodhousebfb44962005-05-21 21:08:09 +01001201 audit_get_stamp(ab->ctx, &t, &serial);
Chris Wright197c69c2005-05-11 10:54:05 +01001202
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1204 t.tv_sec, t.tv_nsec/1000000, serial);
1205 return ab;
1206}
1207
Chris Wright8fc61152005-05-06 15:54:17 +01001208/**
Chris Wright5ac52f32005-05-06 15:54:53 +01001209 * audit_expand - expand skb in the audit buffer
Chris Wright8fc61152005-05-06 15:54:17 +01001210 * @ab: audit_buffer
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001211 * @extra: space to add at tail of the skb
Chris Wright8fc61152005-05-06 15:54:17 +01001212 *
1213 * Returns 0 (no space) on failed expansion, or available space if
1214 * successful.
1215 */
David Woodhousee3b926b2005-05-10 18:56:08 +01001216static inline int audit_expand(struct audit_buffer *ab, int extra)
Chris Wright8fc61152005-05-06 15:54:17 +01001217{
Chris Wright5ac52f32005-05-06 15:54:53 +01001218 struct sk_buff *skb = ab->skb;
Herbert Xu406a1d82008-01-28 20:47:09 -08001219 int oldtail = skb_tailroom(skb);
1220 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1221 int newtail = skb_tailroom(skb);
1222
Chris Wright5ac52f32005-05-06 15:54:53 +01001223 if (ret < 0) {
1224 audit_log_lost("out of memory in audit_expand");
Chris Wright8fc61152005-05-06 15:54:17 +01001225 return 0;
Chris Wright5ac52f32005-05-06 15:54:53 +01001226 }
Herbert Xu406a1d82008-01-28 20:47:09 -08001227
1228 skb->truesize += newtail - oldtail;
1229 return newtail;
Chris Wright8fc61152005-05-06 15:54:17 +01001230}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001232/*
1233 * Format an audit message into the audit buffer. If there isn't enough
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234 * room in the audit buffer, more room will be allocated and vsnprint
1235 * will be called a second time. Currently, we assume that a printk
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001236 * can't format message larger than 1024 bytes, so we don't either.
1237 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1239 va_list args)
1240{
1241 int len, avail;
Chris Wright5ac52f32005-05-06 15:54:53 +01001242 struct sk_buff *skb;
David Woodhouseeecb0a72005-05-10 18:58:51 +01001243 va_list args2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244
1245 if (!ab)
1246 return;
1247
Chris Wright5ac52f32005-05-06 15:54:53 +01001248 BUG_ON(!ab->skb);
1249 skb = ab->skb;
1250 avail = skb_tailroom(skb);
1251 if (avail == 0) {
David Woodhousee3b926b2005-05-10 18:56:08 +01001252 avail = audit_expand(ab, AUDIT_BUFSIZ);
Chris Wright8fc61152005-05-06 15:54:17 +01001253 if (!avail)
1254 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255 }
David Woodhouseeecb0a72005-05-10 18:58:51 +01001256 va_copy(args2, args);
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001257 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 if (len >= avail) {
1259 /* The printk buffer is 1024 bytes long, so if we get
1260 * here and AUDIT_BUFSIZ is at least 1024, then we can
1261 * log everything that printk could have logged. */
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001262 avail = audit_expand(ab,
1263 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
Chris Wright8fc61152005-05-06 15:54:17 +01001264 if (!avail)
1265 goto out;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001266 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 }
Richard Knutsson148b38d2008-01-10 11:02:40 -08001268 va_end(args2);
Steve Grubb168b7172005-05-19 10:24:22 +01001269 if (len > 0)
1270 skb_put(skb, len);
Chris Wright8fc61152005-05-06 15:54:17 +01001271out:
1272 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273}
1274
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001275/**
1276 * audit_log_format - format a message into the audit buffer.
1277 * @ab: audit_buffer
1278 * @fmt: format string
1279 * @...: optional parameters matching @fmt string
1280 *
1281 * All the work is done in audit_log_vformat.
1282 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283void 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
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001294/**
1295 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1296 * @ab: the audit_buffer
1297 * @buf: buffer to convert to hex
1298 * @len: length of @buf to be converted
1299 *
1300 * No return value; failure to expand is silently ignored.
1301 *
1302 * This function will take the passed buf and convert it into a string of
1303 * ascii hex digits. The new string is placed onto the skb.
1304 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001305void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
Steve Grubb168b7172005-05-19 10:24:22 +01001306 size_t len)
83c7d092005-04-29 15:54:44 +01001307{
Steve Grubb168b7172005-05-19 10:24:22 +01001308 int i, avail, new_len;
1309 unsigned char *ptr;
1310 struct sk_buff *skb;
1311 static const unsigned char *hex = "0123456789ABCDEF";
83c7d092005-04-29 15:54:44 +01001312
Amy Griffis8ef2d302006-09-07 17:03:02 -04001313 if (!ab)
1314 return;
1315
Steve Grubb168b7172005-05-19 10:24:22 +01001316 BUG_ON(!ab->skb);
1317 skb = ab->skb;
1318 avail = skb_tailroom(skb);
1319 new_len = len<<1;
1320 if (new_len >= avail) {
1321 /* Round the buffer request up to the next multiple */
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
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001328 ptr = skb_tail_pointer(skb);
Steve Grubb168b7172005-05-19 10:24:22 +01001329 for (i=0; i<len; i++) {
1330 *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
1331 *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */
1332 }
1333 *ptr = 0;
1334 skb_put(skb, len << 1); /* new string is twice the old string */
83c7d092005-04-29 15:54:44 +01001335}
1336
Amy Griffis9c937dc2006-06-08 23:19:31 -04001337/*
1338 * Format a string of no more than slen characters into the audit buffer,
1339 * enclosed in quote marks.
1340 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001341void audit_log_n_string(struct audit_buffer *ab, const char *string,
1342 size_t slen)
Amy Griffis9c937dc2006-06-08 23:19:31 -04001343{
1344 int avail, new_len;
1345 unsigned char *ptr;
1346 struct sk_buff *skb;
1347
Amy Griffis8ef2d302006-09-07 17:03:02 -04001348 if (!ab)
1349 return;
1350
Amy Griffis9c937dc2006-06-08 23:19:31 -04001351 BUG_ON(!ab->skb);
1352 skb = ab->skb;
1353 avail = skb_tailroom(skb);
1354 new_len = slen + 3; /* enclosing quotes + null terminator */
1355 if (new_len > avail) {
1356 avail = audit_expand(ab, new_len);
1357 if (!avail)
1358 return;
1359 }
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001360 ptr = skb_tail_pointer(skb);
Amy Griffis9c937dc2006-06-08 23:19:31 -04001361 *ptr++ = '"';
1362 memcpy(ptr, string, slen);
1363 ptr += slen;
1364 *ptr++ = '"';
1365 *ptr = 0;
1366 skb_put(skb, slen + 2); /* don't include null terminator */
1367}
1368
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001369/**
Eric Parisde6bbd12008-01-07 14:31:58 -05001370 * audit_string_contains_control - does a string need to be logged in hex
Dave Jonesf706d5d2008-03-28 14:15:56 -07001371 * @string: string to be checked
1372 * @len: max length of the string to check
Eric Parisde6bbd12008-01-07 14:31:58 -05001373 */
1374int audit_string_contains_control(const char *string, size_t len)
1375{
1376 const unsigned char *p;
Miloslav Trmacb3897f52009-03-19 09:48:27 -04001377 for (p = string; p < (const unsigned char *)string + len; p++) {
Vesa-Matti J Kari1d6c9642008-07-23 00:06:13 +03001378 if (*p == '"' || *p < 0x21 || *p > 0x7e)
Eric Parisde6bbd12008-01-07 14:31:58 -05001379 return 1;
1380 }
1381 return 0;
1382}
1383
1384/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07001385 * audit_log_n_untrustedstring - log a string that may contain random characters
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001386 * @ab: audit_buffer
Dave Jonesf706d5d2008-03-28 14:15:56 -07001387 * @len: length of string (not including trailing null)
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001388 * @string: string to be logged
1389 *
1390 * This code will escape a string that is passed to it if the string
1391 * contains a control character, unprintable character, double quote mark,
Steve Grubb168b7172005-05-19 10:24:22 +01001392 * or a space. Unescaped strings will start and end with a double quote mark.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001393 * Strings that are escaped are printed in hex (2 digits per char).
Amy Griffis9c937dc2006-06-08 23:19:31 -04001394 *
1395 * The caller specifies the number of characters in the string to log, which may
1396 * or may not be the entire string.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001397 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001398void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1399 size_t len)
83c7d092005-04-29 15:54:44 +01001400{
Eric Parisde6bbd12008-01-07 14:31:58 -05001401 if (audit_string_contains_control(string, len))
Eric Parisb556f8a2008-04-18 10:12:59 -04001402 audit_log_n_hex(ab, string, len);
Eric Parisde6bbd12008-01-07 14:31:58 -05001403 else
Eric Parisb556f8a2008-04-18 10:12:59 -04001404 audit_log_n_string(ab, string, len);
83c7d092005-04-29 15:54:44 +01001405}
1406
Amy Griffis9c937dc2006-06-08 23:19:31 -04001407/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07001408 * audit_log_untrustedstring - log a string that may contain random characters
Amy Griffis9c937dc2006-06-08 23:19:31 -04001409 * @ab: audit_buffer
1410 * @string: string to be logged
1411 *
Miloslav Trmac522ed772007-07-15 23:40:56 -07001412 * Same as audit_log_n_untrustedstring(), except that strlen is used to
Amy Griffis9c937dc2006-06-08 23:19:31 -04001413 * determine string length.
1414 */
Eric Parisde6bbd12008-01-07 14:31:58 -05001415void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
Amy Griffis9c937dc2006-06-08 23:19:31 -04001416{
Eric Parisb556f8a2008-04-18 10:12:59 -04001417 audit_log_n_untrustedstring(ab, string, strlen(string));
Amy Griffis9c937dc2006-06-08 23:19:31 -04001418}
1419
Steve Grubb168b7172005-05-19 10:24:22 +01001420/* This is a helper-function to print the escaped d_path */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
Jan Blunck44707fd2008-02-14 19:38:33 -08001422 struct path *path)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001423{
Jan Blunck44707fd2008-02-14 19:38:33 -08001424 char *p, *pathname;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425
Chris Wright8fc61152005-05-06 15:54:17 +01001426 if (prefix)
1427 audit_log_format(ab, " %s", prefix);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428
Steve Grubb168b7172005-05-19 10:24:22 +01001429 /* We will allow 11 spaces for ' (deleted)' to be appended */
Jan Blunck44707fd2008-02-14 19:38:33 -08001430 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1431 if (!pathname) {
Eric Parisdef57542009-03-10 18:00:14 -04001432 audit_log_string(ab, "<no_memory>");
Steve Grubb168b7172005-05-19 10:24:22 +01001433 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 }
Jan Blunckcf28b482008-02-14 19:38:44 -08001435 p = d_path(path, pathname, PATH_MAX+11);
Steve Grubb168b7172005-05-19 10:24:22 +01001436 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1437 /* FIXME: can we save some information here? */
Eric Parisdef57542009-03-10 18:00:14 -04001438 audit_log_string(ab, "<too_long>");
Daniel Walker5600b892007-10-18 03:06:10 -07001439 } else
Steve Grubb168b7172005-05-19 10:24:22 +01001440 audit_log_untrustedstring(ab, p);
Jan Blunck44707fd2008-02-14 19:38:33 -08001441 kfree(pathname);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001442}
1443
Eric Paris9d960982009-06-11 14:31:37 -04001444void 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
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001453/**
1454 * audit_log_end - end one audit record
1455 * @ab: the audit_buffer
1456 *
1457 * The netlink_* functions cannot be called inside an irq context, so
1458 * the audit buffer is placed on a queue and a tasklet is scheduled to
Linus Torvalds1da177e2005-04-16 15:20:36 -07001459 * remove them from the queue outside the irq context. May be called in
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001460 * any context.
1461 */
David Woodhouseb7d11252005-05-19 10:56:58 +01001462void audit_log_end(struct audit_buffer *ab)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001464 if (!ab)
1465 return;
1466 if (!audit_rate_check()) {
1467 audit_log_lost("rate limit exceeded");
1468 } else {
Steve Grubb8d07a67c2008-02-21 16:59:22 -05001469 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
Eric Parisf3d357b2008-04-18 10:02:28 -04001470 nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
1471
David Woodhouseb7d11252005-05-19 10:56:58 +01001472 if (audit_pid) {
David Woodhouseb7d11252005-05-19 10:56:58 +01001473 skb_queue_tail(&audit_skb_queue, ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001474 wake_up_interruptible(&kauditd_wait);
Eric Parisf3d357b2008-04-18 10:02:28 -04001475 } else {
Eric Paris038cbcf2009-06-11 14:31:35 -04001476 audit_printk_skb(ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001477 }
Eric Parisf3d357b2008-04-18 10:02:28 -04001478 ab->skb = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001479 }
Chris Wright16e19042005-05-06 15:53:34 +01001480 audit_buffer_free(ab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001481}
1482
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001483/**
1484 * audit_log - Log an audit record
1485 * @ctx: audit context
1486 * @gfp_mask: type of allocation
1487 * @type: audit message type
1488 * @fmt: format string to use
1489 * @...: variable parameters matching the format string
1490 *
1491 * This is a convenience function that calls audit_log_start,
1492 * audit_log_vformat, and audit_log_end. It may be called
1493 * in any context.
1494 */
Daniel Walker5600b892007-10-18 03:06:10 -07001495void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001496 const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001497{
1498 struct audit_buffer *ab;
1499 va_list args;
1500
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001501 ab = audit_log_start(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001502 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}
lorenzo@gnu.orgbf45da92006-03-09 00:33:47 +01001509
1510EXPORT_SYMBOL(audit_log_start);
1511EXPORT_SYMBOL(audit_log_end);
1512EXPORT_SYMBOL(audit_log_format);
1513EXPORT_SYMBOL(audit_log);