blob: 9816a1b96cfc5c5ca1ed3ed4642116e8cd8e11d3 [file] [log] [blame]
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 Grubb6a01b072007-01-19 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>
Arun Sharma600634972011-07-26 16:09:06 -070046#include <linux/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <linux/mm.h>
Paul Gortmaker9984de12011-05-23 14:51:41 -040048#include <linux/export.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090049#include <linux/slab.h>
David Woodhouseb7d11252005-05-19 10:56:58 +010050#include <linux/err.h>
51#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53#include <linux/audit.h>
54
55#include <net/sock.h>
Amy Griffis93315ed2006-02-07 12:05:27 -050056#include <net/netlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070057#include <linux/skbuff.h>
Mr Dash Four131ad622011-06-30 13:31:57 +020058#ifdef CONFIG_SECURITY
59#include <linux/security.h>
60#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070061#include <linux/netlink.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080062#include <linux/freezer.h>
Miloslav Trmac522ed772007-07-15 23:40:56 -070063#include <linux/tty.h>
Eric W. Biederman34e36d82012-09-10 23:20:20 -070064#include <linux/pid_namespace.h>
Darrel Goeddel3dc7e312006-03-10 18:14:06 -060065
66#include "audit.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
Eric Parisa3f07112008-11-05 12:47:09 -050068/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 * (Initialization happens after skb_init is called.) */
Eric Parisa3f07112008-11-05 12:47:09 -050070#define AUDIT_DISABLED -1
71#define AUDIT_UNINITIALIZED 0
72#define AUDIT_INITIALIZED 1
Linus Torvalds1da177e2005-04-16 15:20:36 -070073static int audit_initialized;
74
Eric Paris1a6b9f22008-01-07 17:09:31 -050075#define AUDIT_OFF 0
76#define AUDIT_ON 1
77#define AUDIT_LOCKED 2
Linus Torvalds1da177e2005-04-16 15:20:36 -070078int audit_enabled;
Eric Parisb593d382008-01-08 17:38:31 -050079int audit_ever_enabled;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Jan Engelhardtae9d67af2011-01-18 06:48:12 +010081EXPORT_SYMBOL_GPL(audit_enabled);
82
Linus Torvalds1da177e2005-04-16 15:20:36 -070083/* Default state when kernel boots without any parameters. */
84static int audit_default;
85
86/* If auditing cannot proceed, audit_failure selects what happens. */
87static int audit_failure = AUDIT_FAIL_PRINTK;
88
Pavel Emelyanov75c03712008-03-20 15:39:41 -070089/*
90 * If audit records are to be written to the netlink socket, audit_pid
Eric W. Biederman15e47302012-09-07 20:12:54 +000091 * contains the pid of the auditd process and audit_nlk_portid contains
92 * the portid to use to send netlink messages to that process.
Pavel Emelyanov75c03712008-03-20 15:39:41 -070093 */
Steve Grubbc2f0c7c2005-05-06 12:38:39 +010094int audit_pid;
Eric W. Biederman15e47302012-09-07 20:12:54 +000095static int audit_nlk_portid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
Randy Dunlapb0dd25a2005-09-13 12:47:11 -070097/* If audit_rate_limit is non-zero, limit the rate of sending audit records
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 * to that number per second. This prevents DoS attacks, but results in
99 * audit records being dropped. */
100static int audit_rate_limit;
101
102/* Number of outstanding audit_buffers allowed. */
103static int audit_backlog_limit = 64;
David Woodhouseac4cec42005-07-02 14:08:48 +0100104static int audit_backlog_wait_time = 60 * HZ;
105static int audit_backlog_wait_overflow = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100107/* The identity of the user shutting down the audit system. */
Eric W. Biedermancca080d2012-02-07 16:53:48 -0800108kuid_t audit_sig_uid = INVALID_UID;
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100109pid_t audit_sig_pid = -1;
Al Viroe1396062006-05-25 10:19:47 -0400110u32 audit_sig_sid = 0;
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100111
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112/* Records can be lost in several ways:
113 0) [suppressed in audit_alloc]
114 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
115 2) out of memory in audit_log_move [alloc_skb]
116 3) suppressed due to audit_rate_limit
117 4) suppressed due to audit_backlog_limit
118*/
119static atomic_t audit_lost = ATOMIC_INIT(0);
120
121/* The netlink socket. */
122static struct sock *audit_sock;
123
Amy Griffisf368c07d2006-04-07 16:55:56 -0400124/* Hash for inode-based rules */
125struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
126
David Woodhouseb7d11252005-05-19 10:56:58 +0100127/* The audit_freelist is a list of pre-allocated audit buffers (if more
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
129 * being placed on the freelist). */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130static DEFINE_SPINLOCK(audit_freelist_lock);
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700131static int audit_freelist_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132static LIST_HEAD(audit_freelist);
133
David Woodhouseb7d11252005-05-19 10:56:58 +0100134static struct sk_buff_head audit_skb_queue;
Eric Parisf3d357b2008-04-18 10:02:28 -0400135/* queue of skbs to send to auditd when/if it comes back */
136static struct sk_buff_head audit_skb_hold_queue;
David Woodhouseb7d11252005-05-19 10:56:58 +0100137static struct task_struct *kauditd_task;
138static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100139static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140
Amy Griffisf368c07d2006-04-07 16:55:56 -0400141/* Serialize requests from userspace. */
Al Viro916d7572009-06-24 00:02:38 -0400142DEFINE_MUTEX(audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
144/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
145 * audit records. Since printk uses a 1024 byte buffer, this buffer
146 * should be at least that large. */
147#define AUDIT_BUFSIZ 1024
148
149/* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
150 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
151#define AUDIT_MAXFREE (2*NR_CPUS)
152
153/* The audit_buffer is used when formatting an audit record. The caller
154 * locks briefly to get the record off the freelist or to allocate the
155 * buffer, and locks briefly to send the buffer to the netlink layer or
156 * to place it on a transmit queue. Multiple audit_buffers can be in
157 * use simultaneously. */
158struct audit_buffer {
159 struct list_head list;
Chris Wright8fc61152005-05-06 15:54:17 +0100160 struct sk_buff *skb; /* formatted skb ready to send */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 struct audit_context *ctx; /* NULL or associated context */
Al Viro9796fdd2005-10-21 03:22:03 -0400162 gfp_t gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163};
164
Eric Parisf09ac9d2008-04-18 10:11:04 -0400165struct audit_reply {
166 int pid;
167 struct sk_buff *skb;
168};
169
Steve Grubbc0404992005-05-13 18:17:42 +0100170static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
171{
Eric Paris50397bd2008-01-07 18:14:19 -0500172 if (ab) {
173 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
174 nlh->nlmsg_pid = pid;
175 }
Steve Grubbc0404992005-05-13 18:17:42 +0100176}
177
Dustin Kirkland8c8570f2005-11-03 17:15:16 +0000178void audit_panic(const char *message)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
180 switch (audit_failure)
181 {
182 case AUDIT_FAIL_SILENT:
183 break;
184 case AUDIT_FAIL_PRINTK:
Eric Paris320f1b12008-01-23 22:55:05 -0500185 if (printk_ratelimit())
186 printk(KERN_ERR "audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 break;
188 case AUDIT_FAIL_PANIC:
Eric Parisb29ee872008-02-21 15:53:05 -0500189 /* test audit_pid since printk is always losey, why bother? */
190 if (audit_pid)
191 panic("audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 break;
193 }
194}
195
196static inline int audit_rate_check(void)
197{
198 static unsigned long last_check = 0;
199 static int messages = 0;
200 static DEFINE_SPINLOCK(lock);
201 unsigned long flags;
202 unsigned long now;
203 unsigned long elapsed;
204 int retval = 0;
205
206 if (!audit_rate_limit) return 1;
207
208 spin_lock_irqsave(&lock, flags);
209 if (++messages < audit_rate_limit) {
210 retval = 1;
211 } else {
212 now = jiffies;
213 elapsed = now - last_check;
214 if (elapsed > HZ) {
215 last_check = now;
216 messages = 0;
217 retval = 1;
218 }
219 }
220 spin_unlock_irqrestore(&lock, flags);
221
222 return retval;
223}
224
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700225/**
226 * audit_log_lost - conditionally log lost audit message event
227 * @message: the message stating reason for lost audit message
228 *
229 * Emit at least 1 message per second, even if audit_rate_check is
230 * throttling.
231 * Always increment the lost messages counter.
232*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233void audit_log_lost(const char *message)
234{
235 static unsigned long last_msg = 0;
236 static DEFINE_SPINLOCK(lock);
237 unsigned long flags;
238 unsigned long now;
239 int print;
240
241 atomic_inc(&audit_lost);
242
243 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
244
245 if (!print) {
246 spin_lock_irqsave(&lock, flags);
247 now = jiffies;
248 if (now - last_msg > HZ) {
249 print = 1;
250 last_msg = now;
251 }
252 spin_unlock_irqrestore(&lock, flags);
253 }
254
255 if (print) {
Eric Paris320f1b12008-01-23 22:55:05 -0500256 if (printk_ratelimit())
257 printk(KERN_WARNING
258 "audit: audit_lost=%d audit_rate_limit=%d "
259 "audit_backlog_limit=%d\n",
260 atomic_read(&audit_lost),
261 audit_rate_limit,
262 audit_backlog_limit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 audit_panic(message);
264 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
Eric Paris1a6b9f22008-01-07 17:09:31 -0500267static int audit_log_config_change(char *function_name, int new, int old,
Eric W. Biedermane1760bd2012-09-10 22:39:43 -0700268 kuid_t loginuid, u32 sessionid, u32 sid,
Eric Paris25323862008-04-18 10:09:25 -0400269 int allow_changes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500271 struct audit_buffer *ab;
272 int rc = 0;
Steve Grubb6a01b072007-01-19 14:39:55 -0500273
Eric Paris1a6b9f22008-01-07 17:09:31 -0500274 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
Kees Cook0644ec02013-01-11 14:32:07 -0800275 if (unlikely(!ab))
276 return rc;
Eric Paris25323862008-04-18 10:09:25 -0400277 audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
Eric W. Biedermane1760bd2012-09-10 22:39:43 -0700278 old, from_kuid(&init_user_ns, loginuid), sessionid);
Steve Grubbce29b682006-04-01 18:29:34 -0500279 if (sid) {
280 char *ctx = NULL;
281 u32 len;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500282
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200283 rc = security_secid_to_secctx(sid, &ctx, &len);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500284 if (rc) {
285 audit_log_format(ab, " sid=%u", sid);
286 allow_changes = 0; /* Something weird, deny request */
287 } else {
288 audit_log_format(ab, " subj=%s", ctx);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200289 security_release_secctx(ctx, len);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500290 }
Steve Grubb6a01b072007-01-19 14:39:55 -0500291 }
Eric Paris1a6b9f22008-01-07 17:09:31 -0500292 audit_log_format(ab, " res=%d", allow_changes);
293 audit_log_end(ab);
294 return rc;
295}
296
297static int audit_do_config_change(char *function_name, int *to_change,
Eric W. Biedermane1760bd2012-09-10 22:39:43 -0700298 int new, kuid_t loginuid, u32 sessionid,
Eric Paris25323862008-04-18 10:09:25 -0400299 u32 sid)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500300{
301 int allow_changes, rc = 0, old = *to_change;
302
303 /* check if we are locked */
304 if (audit_enabled == AUDIT_LOCKED)
305 allow_changes = 0;
306 else
307 allow_changes = 1;
308
309 if (audit_enabled != AUDIT_OFF) {
Eric Paris25323862008-04-18 10:09:25 -0400310 rc = audit_log_config_change(function_name, new, old, loginuid,
311 sessionid, sid, allow_changes);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500312 if (rc)
313 allow_changes = 0;
314 }
Steve Grubb6a01b072007-01-19 14:39:55 -0500315
316 /* If we are allowed, make the change */
Eric Paris1a6b9f22008-01-07 17:09:31 -0500317 if (allow_changes == 1)
318 *to_change = new;
Steve Grubb6a01b072007-01-19 14:39:55 -0500319 /* Not allowed, update reason */
320 else if (rc == 0)
321 rc = -EPERM;
322 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323}
324
Eric W. Biedermane1760bd2012-09-10 22:39:43 -0700325static int audit_set_rate_limit(int limit, kuid_t loginuid, u32 sessionid,
Eric Paris25323862008-04-18 10:09:25 -0400326 u32 sid)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500327{
328 return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
Eric Paris25323862008-04-18 10:09:25 -0400329 limit, loginuid, sessionid, sid);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500330}
331
Eric W. Biedermane1760bd2012-09-10 22:39:43 -0700332static int audit_set_backlog_limit(int limit, kuid_t loginuid, u32 sessionid,
Eric Paris25323862008-04-18 10:09:25 -0400333 u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500335 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
Eric Paris25323862008-04-18 10:09:25 -0400336 limit, loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337}
338
Eric W. Biedermane1760bd2012-09-10 22:39:43 -0700339static int audit_set_enabled(int state, kuid_t loginuid, u32 sessionid, u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340{
Eric Parisb593d382008-01-08 17:38:31 -0500341 int rc;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500342 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500344
Eric Parisb593d382008-01-08 17:38:31 -0500345 rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
Eric Paris25323862008-04-18 10:09:25 -0400346 loginuid, sessionid, sid);
Eric Parisb593d382008-01-08 17:38:31 -0500347
348 if (!rc)
349 audit_ever_enabled |= !!state;
350
351 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352}
353
Eric W. Biedermane1760bd2012-09-10 22:39:43 -0700354static int audit_set_failure(int state, kuid_t loginuid, u32 sessionid, u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 if (state != AUDIT_FAIL_SILENT
357 && state != AUDIT_FAIL_PRINTK
358 && state != AUDIT_FAIL_PANIC)
359 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500360
Eric Paris1a6b9f22008-01-07 17:09:31 -0500361 return audit_do_config_change("audit_failure", &audit_failure, state,
Eric Paris25323862008-04-18 10:09:25 -0400362 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363}
364
Eric Parisf3d357b2008-04-18 10:02:28 -0400365/*
366 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
367 * already have been sent via prink/syslog and so if these messages are dropped
368 * it is not a huge concern since we already passed the audit_log_lost()
369 * notification and stuff. This is just nice to get audit messages during
370 * boot before auditd is running or messages generated while auditd is stopped.
371 * This only holds messages is audit_default is set, aka booting with audit=1
372 * or building your kernel that way.
373 */
374static void audit_hold_skb(struct sk_buff *skb)
375{
376 if (audit_default &&
377 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
378 skb_queue_tail(&audit_skb_hold_queue, skb);
379 else
380 kfree_skb(skb);
381}
382
Eric Paris038cbcf2009-06-11 14:31:35 -0400383/*
384 * For one reason or another this nlh isn't getting delivered to the userspace
385 * audit daemon, just send it to printk.
386 */
387static void audit_printk_skb(struct sk_buff *skb)
388{
389 struct nlmsghdr *nlh = nlmsg_hdr(skb);
David S. Millerc64e66c2012-06-26 21:45:21 -0700390 char *data = nlmsg_data(nlh);
Eric Paris038cbcf2009-06-11 14:31:35 -0400391
392 if (nlh->nlmsg_type != AUDIT_EOE) {
393 if (printk_ratelimit())
394 printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data);
395 else
396 audit_log_lost("printk limit exceeded\n");
397 }
398
399 audit_hold_skb(skb);
400}
401
Eric Parisf3d357b2008-04-18 10:02:28 -0400402static void kauditd_send_skb(struct sk_buff *skb)
403{
404 int err;
405 /* take a reference in case we can't send it and we want to hold it */
406 skb_get(skb);
Eric W. Biederman15e47302012-09-07 20:12:54 +0000407 err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
Eric Parisf3d357b2008-04-18 10:02:28 -0400408 if (err < 0) {
Adam Buchbinderc9404c92009-12-18 15:40:42 -0500409 BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
Eric Parisf3d357b2008-04-18 10:02:28 -0400410 printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
Ross Kirk9db3b9b2010-10-22 16:43:17 +0100411 audit_log_lost("auditd disappeared\n");
Eric Parisf3d357b2008-04-18 10:02:28 -0400412 audit_pid = 0;
413 /* we might get lucky and get this in the next auditd */
414 audit_hold_skb(skb);
415 } else
416 /* drop the extra reference if sent ok */
Neil Horman70d4bf62010-07-20 06:45:56 +0000417 consume_skb(skb);
Eric Parisf3d357b2008-04-18 10:02:28 -0400418}
419
Adrian Bunk97a41e22006-01-08 01:02:17 -0800420static int kauditd_thread(void *dummy)
David Woodhouseb7d11252005-05-19 10:56:58 +0100421{
422 struct sk_buff *skb;
423
Rafael J. Wysocki83144182007-07-17 04:03:35 -0700424 set_freezable();
Andrew Morton4899b8b2006-10-06 00:43:48 -0700425 while (!kthread_should_stop()) {
Eric Parisf3d357b2008-04-18 10:02:28 -0400426 /*
427 * if auditd just started drain the queue of messages already
428 * sent to syslog/printk. remember loss here is ok. we already
429 * called audit_log_lost() if it didn't go out normally. so the
430 * race between the skb_dequeue and the next check for audit_pid
431 * doesn't matter.
432 *
433 * if you ever find kauditd to be too slow we can get a perf win
434 * by doing our own locking and keeping better track if there
435 * are messages in this queue. I don't see the need now, but
436 * in 5 years when I want to play with this again I'll see this
437 * note and still have no friggin idea what i'm thinking today.
438 */
439 if (audit_default && audit_pid) {
440 skb = skb_dequeue(&audit_skb_hold_queue);
441 if (unlikely(skb)) {
442 while (skb && audit_pid) {
443 kauditd_send_skb(skb);
444 skb = skb_dequeue(&audit_skb_hold_queue);
445 }
446 }
447 }
448
David Woodhouseb7d11252005-05-19 10:56:58 +0100449 skb = skb_dequeue(&audit_skb_queue);
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100450 wake_up(&audit_backlog_wait);
David Woodhouseb7d11252005-05-19 10:56:58 +0100451 if (skb) {
Eric Parisf3d357b2008-04-18 10:02:28 -0400452 if (audit_pid)
453 kauditd_send_skb(skb);
Eric Paris038cbcf2009-06-11 14:31:35 -0400454 else
455 audit_printk_skb(skb);
David Woodhouseb7d11252005-05-19 10:56:58 +0100456 } else {
457 DECLARE_WAITQUEUE(wait, current);
458 set_current_state(TASK_INTERRUPTIBLE);
459 add_wait_queue(&kauditd_wait, &wait);
460
Pierre Ossman7a4ae742005-12-12 00:37:22 -0800461 if (!skb_queue_len(&audit_skb_queue)) {
462 try_to_freeze();
David Woodhouseb7d11252005-05-19 10:56:58 +0100463 schedule();
Pierre Ossman7a4ae742005-12-12 00:37:22 -0800464 }
David Woodhouseb7d11252005-05-19 10:56:58 +0100465
466 __set_current_state(TASK_RUNNING);
467 remove_wait_queue(&kauditd_wait, &wait);
468 }
469 }
Andrew Morton4899b8b2006-10-06 00:43:48 -0700470 return 0;
David Woodhouseb7d11252005-05-19 10:56:58 +0100471}
472
Al Viro9044e6b2006-05-22 01:09:24 -0400473int audit_send_list(void *_dest)
474{
475 struct audit_netlink_list *dest = _dest;
476 int pid = dest->pid;
477 struct sk_buff *skb;
478
479 /* wait for parent to finish and send an ACK */
Amy Griffisf368c07d2006-04-07 16:55:56 -0400480 mutex_lock(&audit_cmd_mutex);
481 mutex_unlock(&audit_cmd_mutex);
Al Viro9044e6b2006-05-22 01:09:24 -0400482
483 while ((skb = __skb_dequeue(&dest->q)) != NULL)
484 netlink_unicast(audit_sock, skb, pid, 0);
485
486 kfree(dest);
487
488 return 0;
489}
490
491struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
Stephen Hemmingerb8800aa2010-10-20 17:23:50 -0700492 int multi, const void *payload, int size)
Al Viro9044e6b2006-05-22 01:09:24 -0400493{
494 struct sk_buff *skb;
495 struct nlmsghdr *nlh;
Al Viro9044e6b2006-05-22 01:09:24 -0400496 void *data;
497 int flags = multi ? NLM_F_MULTI : 0;
498 int t = done ? NLMSG_DONE : type;
499
Eric Parisee080e62009-06-11 14:31:35 -0400500 skb = nlmsg_new(size, GFP_KERNEL);
Al Viro9044e6b2006-05-22 01:09:24 -0400501 if (!skb)
502 return NULL;
503
David S. Millerc64e66c2012-06-26 21:45:21 -0700504 nlh = nlmsg_put(skb, pid, seq, t, size, flags);
505 if (!nlh)
506 goto out_kfree_skb;
507 data = nlmsg_data(nlh);
Al Viro9044e6b2006-05-22 01:09:24 -0400508 memcpy(data, payload, size);
509 return skb;
510
David S. Millerc64e66c2012-06-26 21:45:21 -0700511out_kfree_skb:
512 kfree_skb(skb);
Al Viro9044e6b2006-05-22 01:09:24 -0400513 return NULL;
514}
515
Eric Parisf09ac9d2008-04-18 10:11:04 -0400516static int audit_send_reply_thread(void *arg)
517{
518 struct audit_reply *reply = (struct audit_reply *)arg;
519
520 mutex_lock(&audit_cmd_mutex);
521 mutex_unlock(&audit_cmd_mutex);
522
523 /* Ignore failure. It'll only happen if the sender goes away,
524 because our timeout is set to infinite. */
525 netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
526 kfree(reply);
527 return 0;
528}
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700529/**
530 * audit_send_reply - send an audit reply message via netlink
531 * @pid: process id to send reply to
532 * @seq: sequence number
533 * @type: audit message type
534 * @done: done (last) flag
535 * @multi: multi-part message flag
536 * @payload: payload data
537 * @size: payload size
538 *
539 * Allocates an skb, builds the netlink message, and sends it to the pid.
540 * No failure notifications.
541 */
Stephen Hemmingerb8800aa2010-10-20 17:23:50 -0700542static void audit_send_reply(int pid, int seq, int type, int done, int multi,
543 const void *payload, int size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544{
Eric Parisf09ac9d2008-04-18 10:11:04 -0400545 struct sk_buff *skb;
546 struct task_struct *tsk;
547 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
548 GFP_KERNEL);
549
550 if (!reply)
551 return;
552
Al Viro9044e6b2006-05-22 01:09:24 -0400553 skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 if (!skb)
Andrew Mortonfcaf1eb2008-05-14 16:11:48 -0700555 goto out;
Eric Parisf09ac9d2008-04-18 10:11:04 -0400556
557 reply->pid = pid;
558 reply->skb = skb;
559
560 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
Andrew Mortonfcaf1eb2008-05-14 16:11:48 -0700561 if (!IS_ERR(tsk))
562 return;
563 kfree_skb(skb);
564out:
565 kfree(reply);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566}
567
568/*
569 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
570 * control messages.
571 */
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700572static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573{
574 int err = 0;
575
Eric W. Biederman34e36d82012-09-10 23:20:20 -0700576 /* Only support the initial namespaces for now. */
577 if ((current_user_ns() != &init_user_ns) ||
578 (task_active_pid_ns(current) != &init_pid_ns))
579 return -EPERM;
580
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 switch (msg_type) {
582 case AUDIT_GET:
583 case AUDIT_LIST:
Amy Griffis93315ed2006-02-07 12:05:27 -0500584 case AUDIT_LIST_RULES:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 case AUDIT_SET:
586 case AUDIT_ADD:
Amy Griffis93315ed2006-02-07 12:05:27 -0500587 case AUDIT_ADD_RULE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 case AUDIT_DEL:
Amy Griffis93315ed2006-02-07 12:05:27 -0500589 case AUDIT_DEL_RULE:
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100590 case AUDIT_SIGNAL_INFO:
Miloslav Trmac522ed772007-07-15 23:40:56 -0700591 case AUDIT_TTY_GET:
592 case AUDIT_TTY_SET:
Al Viro74c3cbe2007-07-22 08:04:18 -0400593 case AUDIT_TRIM:
594 case AUDIT_MAKE_EQUIV:
Eric Parisfd778462012-01-03 12:25:16 -0500595 if (!capable(CAP_AUDIT_CONTROL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 err = -EPERM;
597 break;
Steve Grubb05474102005-05-21 00:18:37 +0100598 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700599 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
600 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
Eric Parisfd778462012-01-03 12:25:16 -0500601 if (!capable(CAP_AUDIT_WRITE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 err = -EPERM;
603 break;
604 default: /* bad msg */
605 err = -EINVAL;
606 }
607
608 return err;
609}
610
Eric Paris50397bd2008-01-07 18:14:19 -0500611static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
Eric W. Biedermane1760bd2012-09-10 22:39:43 -0700612 kuid_t auid, u32 ses, u32 sid)
Eric Paris50397bd2008-01-07 18:14:19 -0500613{
614 int rc = 0;
615 char *ctx = NULL;
616 u32 len;
617
618 if (!audit_enabled) {
619 *ab = NULL;
620 return rc;
621 }
622
623 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
Kees Cook0644ec02013-01-11 14:32:07 -0800624 if (unlikely(!*ab))
625 return rc;
Eric Paris3035c512012-01-03 14:23:05 -0500626 audit_log_format(*ab, "pid=%d uid=%u auid=%u ses=%u",
Eric W. Biederman860c0aa2012-09-11 00:24:49 -0700627 task_tgid_vnr(current),
628 from_kuid(&init_user_ns, current_uid()),
Eric W. Biedermane1760bd2012-09-10 22:39:43 -0700629 from_kuid(&init_user_ns, auid), ses);
Eric Paris50397bd2008-01-07 18:14:19 -0500630 if (sid) {
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200631 rc = security_secid_to_secctx(sid, &ctx, &len);
Eric Paris50397bd2008-01-07 18:14:19 -0500632 if (rc)
633 audit_log_format(*ab, " ssid=%u", sid);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200634 else {
Eric Paris50397bd2008-01-07 18:14:19 -0500635 audit_log_format(*ab, " subj=%s", ctx);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200636 security_release_secctx(ctx, len);
637 }
Eric Paris50397bd2008-01-07 18:14:19 -0500638 }
639
640 return rc;
641}
642
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
644{
Eric W. Biederman860c0aa2012-09-11 00:24:49 -0700645 u32 seq, sid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 void *data;
647 struct audit_status *status_get, status_set;
648 int err;
Steve Grubbc0404992005-05-13 18:17:42 +0100649 struct audit_buffer *ab;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 u16 msg_type = nlh->nlmsg_type;
Eric W. Biedermane1760bd2012-09-10 22:39:43 -0700651 kuid_t loginuid; /* loginuid of sender */
Eric Paris25323862008-04-18 10:09:25 -0400652 u32 sessionid;
Al Viroe1396062006-05-25 10:19:47 -0400653 struct audit_sig_info *sig_data;
Eric Paris50397bd2008-01-07 18:14:19 -0500654 char *ctx = NULL;
Al Viroe1396062006-05-25 10:19:47 -0400655 u32 len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700657 err = audit_netlink_ok(skb, msg_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 if (err)
659 return err;
660
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700661 /* As soon as there's any sign of userspace auditd,
662 * start kauditd to talk to it */
Gao feng13f51e12013-04-29 15:05:14 -0700663 if (!kauditd_task) {
David Woodhouseb7d11252005-05-19 10:56:58 +0100664 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
Gao feng13f51e12013-04-29 15:05:14 -0700665 if (IS_ERR(kauditd_task)) {
666 err = PTR_ERR(kauditd_task);
667 kauditd_task = NULL;
668 return err;
669 }
David Woodhouseb7d11252005-05-19 10:56:58 +0100670 }
Patrick McHardyc53fa1e2011-03-03 10:55:40 -0800671 loginuid = audit_get_loginuid(current);
672 sessionid = audit_get_sessionid(current);
673 security_task_getsecid(current, &sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 seq = nlh->nlmsg_seq;
David S. Millerc64e66c2012-06-26 21:45:21 -0700675 data = nlmsg_data(nlh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
677 switch (msg_type) {
678 case AUDIT_GET:
679 status_set.enabled = audit_enabled;
680 status_set.failure = audit_failure;
681 status_set.pid = audit_pid;
682 status_set.rate_limit = audit_rate_limit;
683 status_set.backlog_limit = audit_backlog_limit;
684 status_set.lost = atomic_read(&audit_lost);
David Woodhouseb7d11252005-05-19 10:56:58 +0100685 status_set.backlog = skb_queue_len(&audit_skb_queue);
Eric W. Biederman15e47302012-09-07 20:12:54 +0000686 audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 &status_set, sizeof(status_set));
688 break;
689 case AUDIT_SET:
690 if (nlh->nlmsg_len < sizeof(struct audit_status))
691 return -EINVAL;
692 status_get = (struct audit_status *)data;
693 if (status_get->mask & AUDIT_STATUS_ENABLED) {
Steve Grubbce29b682006-04-01 18:29:34 -0500694 err = audit_set_enabled(status_get->enabled,
Eric Paris25323862008-04-18 10:09:25 -0400695 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800696 if (err < 0)
697 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 }
699 if (status_get->mask & AUDIT_STATUS_FAILURE) {
Steve Grubbce29b682006-04-01 18:29:34 -0500700 err = audit_set_failure(status_get->failure,
Eric Paris25323862008-04-18 10:09:25 -0400701 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800702 if (err < 0)
703 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 }
705 if (status_get->mask & AUDIT_STATUS_PID) {
Eric Paris1a6b9f22008-01-07 17:09:31 -0500706 int new_pid = status_get->pid;
707
708 if (audit_enabled != AUDIT_OFF)
709 audit_log_config_change("audit_pid", new_pid,
710 audit_pid, loginuid,
Eric Paris25323862008-04-18 10:09:25 -0400711 sessionid, sid, 1);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500712
713 audit_pid = new_pid;
Eric W. Biederman15e47302012-09-07 20:12:54 +0000714 audit_nlk_portid = NETLINK_CB(skb).portid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 }
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800716 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
Serge E. Hallyn5d136a02006-04-27 16:45:14 -0500717 err = audit_set_rate_limit(status_get->rate_limit,
Eric Paris25323862008-04-18 10:09:25 -0400718 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800719 if (err < 0)
720 return err;
721 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
Serge E. Hallyn5d136a02006-04-27 16:45:14 -0500723 err = audit_set_backlog_limit(status_get->backlog_limit,
Eric Paris25323862008-04-18 10:09:25 -0400724 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 break;
Steve Grubb05474102005-05-21 00:18:37 +0100726 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700727 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
728 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
David Woodhouse4a4cd632005-06-22 14:56:47 +0100729 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
730 return 0;
David Woodhouse0f45aa12005-06-19 19:35:50 +0100731
Eric W. Biederman02276bd2012-09-10 23:10:16 -0700732 err = audit_filter_user();
David Woodhouse4a4cd632005-06-22 14:56:47 +0100733 if (err == 1) {
734 err = 0;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700735 if (msg_type == AUDIT_USER_TTY) {
Eric W. Biedermanf95732e2012-09-10 23:31:17 -0700736 err = tty_audit_push_task(current, loginuid,
Eric Paris25323862008-04-18 10:09:25 -0400737 sessionid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700738 if (err)
739 break;
740 }
Eric W. Biederman860c0aa2012-09-11 00:24:49 -0700741 audit_log_common_recv_msg(&ab, msg_type,
Eric Paris25323862008-04-18 10:09:25 -0400742 loginuid, sessionid, sid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700743
Eric Paris50397bd2008-01-07 18:14:19 -0500744 if (msg_type != AUDIT_USER_TTY)
745 audit_log_format(ab, " msg='%.1024s'",
746 (char *)data);
747 else {
748 int size;
749
750 audit_log_format(ab, " msg=");
751 size = nlmsg_len(nlh);
Miloslav Trmac55ad2f82009-03-19 09:52:47 -0400752 if (size > 0 &&
753 ((unsigned char *)data)[size - 1] == '\0')
754 size--;
Eric Parisb556f8a2008-04-18 10:12:59 -0400755 audit_log_n_untrustedstring(ab, data, size);
David Woodhouse4a4cd632005-06-22 14:56:47 +0100756 }
Linus Torvaldsaecdc332012-10-02 13:38:27 -0700757 audit_set_pid(ab, NETLINK_CB(skb).portid);
Eric Paris50397bd2008-01-07 18:14:19 -0500758 audit_log_end(ab);
David Woodhouse0f45aa12005-06-19 19:35:50 +0100759 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 break;
761 case AUDIT_ADD:
762 case AUDIT_DEL:
Amy Griffis93315ed2006-02-07 12:05:27 -0500763 if (nlmsg_len(nlh) < sizeof(struct audit_rule))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500765 if (audit_enabled == AUDIT_LOCKED) {
Eric W. Biederman860c0aa2012-09-11 00:24:49 -0700766 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE,
767 loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500768
769 audit_log_format(ab, " audit_enabled=%d res=0",
770 audit_enabled);
771 audit_log_end(ab);
Steve Grubb6a01b072007-01-19 14:39:55 -0500772 return -EPERM;
773 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 /* fallthrough */
775 case AUDIT_LIST:
Eric W. Biederman15e47302012-09-07 20:12:54 +0000776 err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid,
Eric W. Biederman017143f2012-09-11 00:19:06 -0700777 seq, data, nlmsg_len(nlh),
Eric Paris25323862008-04-18 10:09:25 -0400778 loginuid, sessionid, sid);
Amy Griffis93315ed2006-02-07 12:05:27 -0500779 break;
780 case AUDIT_ADD_RULE:
781 case AUDIT_DEL_RULE:
782 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
783 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500784 if (audit_enabled == AUDIT_LOCKED) {
Eric W. Biederman860c0aa2012-09-11 00:24:49 -0700785 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE,
786 loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500787
788 audit_log_format(ab, " audit_enabled=%d res=0",
789 audit_enabled);
790 audit_log_end(ab);
Steve Grubb6a01b072007-01-19 14:39:55 -0500791 return -EPERM;
792 }
Amy Griffis93315ed2006-02-07 12:05:27 -0500793 /* fallthrough */
794 case AUDIT_LIST_RULES:
Eric W. Biederman15e47302012-09-07 20:12:54 +0000795 err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid,
Eric W. Biederman017143f2012-09-11 00:19:06 -0700796 seq, data, nlmsg_len(nlh),
Eric Paris25323862008-04-18 10:09:25 -0400797 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 break;
Al Viro74c3cbe2007-07-22 08:04:18 -0400799 case AUDIT_TRIM:
800 audit_trim_trees();
Eric Paris50397bd2008-01-07 18:14:19 -0500801
Eric W. Biederman860c0aa2012-09-11 00:24:49 -0700802 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE,
803 loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500804
Al Viro74c3cbe2007-07-22 08:04:18 -0400805 audit_log_format(ab, " op=trim res=1");
806 audit_log_end(ab);
807 break;
808 case AUDIT_MAKE_EQUIV: {
809 void *bufp = data;
810 u32 sizes[2];
Harvey Harrison7719e432008-04-27 02:39:56 -0700811 size_t msglen = nlmsg_len(nlh);
Al Viro74c3cbe2007-07-22 08:04:18 -0400812 char *old, *new;
813
814 err = -EINVAL;
Harvey Harrison7719e432008-04-27 02:39:56 -0700815 if (msglen < 2 * sizeof(u32))
Al Viro74c3cbe2007-07-22 08:04:18 -0400816 break;
817 memcpy(sizes, bufp, 2 * sizeof(u32));
818 bufp += 2 * sizeof(u32);
Harvey Harrison7719e432008-04-27 02:39:56 -0700819 msglen -= 2 * sizeof(u32);
820 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
Al Viro74c3cbe2007-07-22 08:04:18 -0400821 if (IS_ERR(old)) {
822 err = PTR_ERR(old);
823 break;
824 }
Harvey Harrison7719e432008-04-27 02:39:56 -0700825 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
Al Viro74c3cbe2007-07-22 08:04:18 -0400826 if (IS_ERR(new)) {
827 err = PTR_ERR(new);
828 kfree(old);
829 break;
830 }
831 /* OK, here comes... */
832 err = audit_tag_tree(old, new);
833
Eric W. Biederman860c0aa2012-09-11 00:24:49 -0700834 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE,
835 loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500836
Al Viro74c3cbe2007-07-22 08:04:18 -0400837 audit_log_format(ab, " op=make_equiv old=");
838 audit_log_untrustedstring(ab, old);
839 audit_log_format(ab, " new=");
840 audit_log_untrustedstring(ab, new);
841 audit_log_format(ab, " res=%d", !err);
842 audit_log_end(ab);
843 kfree(old);
844 kfree(new);
845 break;
846 }
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100847 case AUDIT_SIGNAL_INFO:
Eric Paris939cbf22009-09-23 13:46:00 -0400848 len = 0;
849 if (audit_sig_sid) {
850 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
851 if (err)
852 return err;
853 }
Al Viroe1396062006-05-25 10:19:47 -0400854 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
855 if (!sig_data) {
Eric Paris939cbf22009-09-23 13:46:00 -0400856 if (audit_sig_sid)
857 security_release_secctx(ctx, len);
Al Viroe1396062006-05-25 10:19:47 -0400858 return -ENOMEM;
859 }
Eric W. Biedermancca080d2012-02-07 16:53:48 -0800860 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
Al Viroe1396062006-05-25 10:19:47 -0400861 sig_data->pid = audit_sig_pid;
Eric Paris939cbf22009-09-23 13:46:00 -0400862 if (audit_sig_sid) {
863 memcpy(sig_data->ctx, ctx, len);
864 security_release_secctx(ctx, len);
865 }
Eric W. Biederman15e47302012-09-07 20:12:54 +0000866 audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO,
Al Viroe1396062006-05-25 10:19:47 -0400867 0, 0, sig_data, sizeof(*sig_data) + len);
868 kfree(sig_data);
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100869 break;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700870 case AUDIT_TTY_GET: {
871 struct audit_tty_status s;
Eric W. Biederman8aa14b62012-09-10 23:43:14 -0700872 struct task_struct *tsk = current;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700873
Eric W. Biederman8aa14b62012-09-10 23:43:14 -0700874 spin_lock_irq(&tsk->sighand->siglock);
875 s.enabled = tsk->signal->audit_tty != 0;
876 spin_unlock_irq(&tsk->sighand->siglock);
Thomas Gleixner20703202009-12-09 14:19:35 +0000877
Linus Torvaldsaecdc332012-10-02 13:38:27 -0700878 audit_send_reply(NETLINK_CB(skb).portid, seq,
Eric W. Biederman8aa14b62012-09-10 23:43:14 -0700879 AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
Miloslav Trmac522ed772007-07-15 23:40:56 -0700880 break;
881 }
882 case AUDIT_TTY_SET: {
883 struct audit_tty_status *s;
Eric W. Biederman8aa14b62012-09-10 23:43:14 -0700884 struct task_struct *tsk = current;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700885
886 if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
887 return -EINVAL;
888 s = data;
889 if (s->enabled != 0 && s->enabled != 1)
890 return -EINVAL;
Eric W. Biederman8aa14b62012-09-10 23:43:14 -0700891
892 spin_lock_irq(&tsk->sighand->siglock);
893 tsk->signal->audit_tty = s->enabled != 0;
894 spin_unlock_irq(&tsk->sighand->siglock);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700895 break;
896 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 default:
898 err = -EINVAL;
899 break;
900 }
901
902 return err < 0 ? err : 0;
903}
904
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700905/*
Eric Parisea7ae602009-06-11 14:31:35 -0400906 * Get message from skb. Each message is processed by audit_receive_msg.
907 * Malformed skbs with wrong length are discarded silently.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700908 */
Herbert Xu2a0a6eb2005-05-03 14:55:09 -0700909static void audit_receive_skb(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910{
Eric Parisea7ae602009-06-11 14:31:35 -0400911 struct nlmsghdr *nlh;
912 /*
913 * len MUST be signed for NLMSG_NEXT to be able to dec it below 0
914 * if the nlmsg_len was not aligned
915 */
916 int len;
917 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918
Eric Parisea7ae602009-06-11 14:31:35 -0400919 nlh = nlmsg_hdr(skb);
920 len = skb->len;
921
922 while (NLMSG_OK(nlh, len)) {
923 err = audit_receive_msg(skb, nlh);
924 /* if err or if this message says it wants a response */
925 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 netlink_ack(skb, nlh, err);
Eric Parisea7ae602009-06-11 14:31:35 -0400927
928 nlh = NLMSG_NEXT(nlh, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930}
931
932/* Receive messages from netlink socket. */
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700933static void audit_receive(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934{
Amy Griffisf368c07d2006-04-07 16:55:56 -0400935 mutex_lock(&audit_cmd_mutex);
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700936 audit_receive_skb(skb);
Amy Griffisf368c07d2006-04-07 16:55:56 -0400937 mutex_unlock(&audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938}
939
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940/* Initialize audit support at boot time. */
941static int __init audit_init(void)
942{
Amy Griffisf368c07d2006-04-07 16:55:56 -0400943 int i;
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +0000944 struct netlink_kernel_cfg cfg = {
945 .input = audit_receive,
946 };
Amy Griffisf368c07d2006-04-07 16:55:56 -0400947
Eric Parisa3f07112008-11-05 12:47:09 -0500948 if (audit_initialized == AUDIT_DISABLED)
949 return 0;
950
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951 printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
952 audit_default ? "enabled" : "disabled");
Pablo Neira Ayuso9f00d972012-09-08 02:53:54 +0000953 audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, &cfg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 if (!audit_sock)
955 audit_panic("cannot initialize netlink socket");
Amy Griffis71e1c782006-03-06 22:40:05 -0500956 else
957 audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958
David Woodhouseb7d11252005-05-19 10:56:58 +0100959 skb_queue_head_init(&audit_skb_queue);
Eric Parisf3d357b2008-04-18 10:02:28 -0400960 skb_queue_head_init(&audit_skb_hold_queue);
Eric Parisa3f07112008-11-05 12:47:09 -0500961 audit_initialized = AUDIT_INITIALIZED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 audit_enabled = audit_default;
Eric Parisb593d382008-01-08 17:38:31 -0500963 audit_ever_enabled |= !!audit_default;
Darrel Goeddel3dc7e312006-03-10 18:14:06 -0600964
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100965 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
Amy Griffisf368c07d2006-04-07 16:55:56 -0400966
Amy Griffisf368c07d2006-04-07 16:55:56 -0400967 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
968 INIT_LIST_HEAD(&audit_inode_hash[i]);
Amy Griffisf368c07d2006-04-07 16:55:56 -0400969
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970 return 0;
971}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972__initcall(audit_init);
973
974/* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
975static int __init audit_enable(char *str)
976{
977 audit_default = !!simple_strtol(str, NULL, 0);
Eric Parisa3f07112008-11-05 12:47:09 -0500978 if (!audit_default)
979 audit_initialized = AUDIT_DISABLED;
980
981 printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
982
983 if (audit_initialized == AUDIT_INITIALIZED) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984 audit_enabled = audit_default;
Eric Parisb593d382008-01-08 17:38:31 -0500985 audit_ever_enabled |= !!audit_default;
Eric Parisa3f07112008-11-05 12:47:09 -0500986 } else if (audit_initialized == AUDIT_UNINITIALIZED) {
987 printk(" (after initialization)");
988 } else {
989 printk(" (until reboot)");
Eric Parisb593d382008-01-08 17:38:31 -0500990 }
Eric Parisa3f07112008-11-05 12:47:09 -0500991 printk("\n");
992
OGAWA Hirofumi9b410462006-03-31 02:30:33 -0800993 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994}
995
996__setup("audit=", audit_enable);
997
Chris Wright16e19042005-05-06 15:53:34 +0100998static void audit_buffer_free(struct audit_buffer *ab)
999{
1000 unsigned long flags;
1001
Chris Wright8fc61152005-05-06 15:54:17 +01001002 if (!ab)
1003 return;
1004
Chris Wright5ac52f32005-05-06 15:54:53 +01001005 if (ab->skb)
1006 kfree_skb(ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001007
Chris Wright16e19042005-05-06 15:53:34 +01001008 spin_lock_irqsave(&audit_freelist_lock, flags);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001009 if (audit_freelist_count > AUDIT_MAXFREE)
Chris Wright16e19042005-05-06 15:53:34 +01001010 kfree(ab);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001011 else {
1012 audit_freelist_count++;
Chris Wright16e19042005-05-06 15:53:34 +01001013 list_add(&ab->list, &audit_freelist);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001014 }
Chris Wright16e19042005-05-06 15:53:34 +01001015 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1016}
1017
Steve Grubbc0404992005-05-13 18:17:42 +01001018static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
Al Virodd0fc662005-10-07 07:46:04 +01001019 gfp_t gfp_mask, int type)
Chris Wright16e19042005-05-06 15:53:34 +01001020{
1021 unsigned long flags;
1022 struct audit_buffer *ab = NULL;
Steve Grubbc0404992005-05-13 18:17:42 +01001023 struct nlmsghdr *nlh;
Chris Wright16e19042005-05-06 15:53:34 +01001024
1025 spin_lock_irqsave(&audit_freelist_lock, flags);
1026 if (!list_empty(&audit_freelist)) {
1027 ab = list_entry(audit_freelist.next,
1028 struct audit_buffer, list);
1029 list_del(&ab->list);
1030 --audit_freelist_count;
1031 }
1032 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1033
1034 if (!ab) {
David Woodhouse4332bdd2005-05-06 15:59:57 +01001035 ab = kmalloc(sizeof(*ab), gfp_mask);
Chris Wright16e19042005-05-06 15:53:34 +01001036 if (!ab)
Chris Wright8fc61152005-05-06 15:54:17 +01001037 goto err;
Chris Wright16e19042005-05-06 15:53:34 +01001038 }
Chris Wright8fc61152005-05-06 15:54:17 +01001039
David Woodhouseb7d11252005-05-19 10:56:58 +01001040 ab->ctx = ctx;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001041 ab->gfp_mask = gfp_mask;
Eric Parisee080e62009-06-11 14:31:35 -04001042
1043 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1044 if (!ab->skb)
David S. Millerc64e66c2012-06-26 21:45:21 -07001045 goto err;
Eric Parisee080e62009-06-11 14:31:35 -04001046
David S. Millerc64e66c2012-06-26 21:45:21 -07001047 nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0);
1048 if (!nlh)
1049 goto out_kfree_skb;
Eric Parisee080e62009-06-11 14:31:35 -04001050
Chris Wright16e19042005-05-06 15:53:34 +01001051 return ab;
Eric Parisee080e62009-06-11 14:31:35 -04001052
David S. Millerc64e66c2012-06-26 21:45:21 -07001053out_kfree_skb:
Eric Parisee080e62009-06-11 14:31:35 -04001054 kfree_skb(ab->skb);
1055 ab->skb = NULL;
Chris Wright8fc61152005-05-06 15:54:17 +01001056err:
1057 audit_buffer_free(ab);
1058 return NULL;
Chris Wright16e19042005-05-06 15:53:34 +01001059}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001061/**
1062 * audit_serial - compute a serial number for the audit record
1063 *
1064 * Compute a serial number for the audit record. Audit records are
David Woodhousebfb44962005-05-21 21:08:09 +01001065 * written to user-space as soon as they are generated, so a complete
1066 * audit record may be written in several pieces. The timestamp of the
1067 * record and this serial number are used by the user-space tools to
1068 * determine which pieces belong to the same audit record. The
1069 * (timestamp,serial) tuple is unique for each syscall and is live from
1070 * syscall entry to syscall exit.
1071 *
David Woodhousebfb44962005-05-21 21:08:09 +01001072 * NOTE: Another possibility is to store the formatted records off the
1073 * audit context (for those records that have a context), and emit them
1074 * all at syscall exit. However, this could delay the reporting of
1075 * significant errors until syscall exit (or never, if the system
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001076 * halts).
1077 */
David Woodhousebfb44962005-05-21 21:08:09 +01001078unsigned int audit_serial(void)
1079{
Ingo Molnar34af9462006-06-27 02:53:55 -07001080 static DEFINE_SPINLOCK(serial_lock);
David Woodhoused5b454f2005-07-15 12:56:03 +01001081 static unsigned int serial = 0;
David Woodhousebfb44962005-05-21 21:08:09 +01001082
David Woodhoused5b454f2005-07-15 12:56:03 +01001083 unsigned long flags;
1084 unsigned int ret;
David Woodhousebfb44962005-05-21 21:08:09 +01001085
David Woodhoused5b454f2005-07-15 12:56:03 +01001086 spin_lock_irqsave(&serial_lock, flags);
David Woodhousebfb44962005-05-21 21:08:09 +01001087 do {
David Woodhousece625a82005-07-18 14:24:46 -04001088 ret = ++serial;
1089 } while (unlikely(!ret));
David Woodhoused5b454f2005-07-15 12:56:03 +01001090 spin_unlock_irqrestore(&serial_lock, flags);
David Woodhousebfb44962005-05-21 21:08:09 +01001091
David Woodhoused5b454f2005-07-15 12:56:03 +01001092 return ret;
David Woodhousebfb44962005-05-21 21:08:09 +01001093}
1094
Daniel Walker5600b892007-10-18 03:06:10 -07001095static inline void audit_get_stamp(struct audit_context *ctx,
David Woodhousebfb44962005-05-21 21:08:09 +01001096 struct timespec *t, unsigned int *serial)
1097{
Al Viro48887e62008-12-06 01:05:50 -05001098 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
David Woodhousebfb44962005-05-21 21:08:09 +01001099 *t = CURRENT_TIME;
1100 *serial = audit_serial();
1101 }
1102}
1103
Andrew Morton82919912013-01-11 14:32:11 -08001104/*
1105 * Wait for auditd to drain the queue a little
1106 */
1107static void wait_for_auditd(unsigned long sleep_time)
1108{
1109 DECLARE_WAITQUEUE(wait, current);
1110 set_current_state(TASK_INTERRUPTIBLE);
1111 add_wait_queue(&audit_backlog_wait, &wait);
1112
1113 if (audit_backlog_limit &&
1114 skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
1115 schedule_timeout(sleep_time);
1116
1117 __set_current_state(TASK_RUNNING);
1118 remove_wait_queue(&audit_backlog_wait, &wait);
1119}
1120
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121/* Obtain an audit buffer. This routine does locking to obtain the
1122 * audit buffer, but then no locking is required for calls to
1123 * audit_log_*format. If the tsk is a task that is currently in a
1124 * syscall, then the syscall is marked as auditable and an audit record
1125 * will be written at syscall exit. If there is no associated task, tsk
1126 * should be NULL. */
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001127
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001128/**
1129 * audit_log_start - obtain an audit buffer
1130 * @ctx: audit_context (may be NULL)
1131 * @gfp_mask: type of allocation
1132 * @type: audit message type
1133 *
1134 * Returns audit_buffer pointer on success or NULL on error.
1135 *
1136 * Obtain an audit buffer. This routine does locking to obtain the
1137 * audit buffer, but then no locking is required for calls to
1138 * audit_log_*format. If the task (ctx) is a task that is currently in a
1139 * syscall, then the syscall is marked as auditable and an audit record
1140 * will be written at syscall exit. If there is no associated task, then
1141 * task context (ctx) should be NULL.
1142 */
Al Viro9796fdd2005-10-21 03:22:03 -04001143struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001144 int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145{
1146 struct audit_buffer *ab = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147 struct timespec t;
Andrew Mortonef00be02008-01-10 11:02:39 -08001148 unsigned int uninitialized_var(serial);
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001149 int reserve;
David Woodhouseac4cec42005-07-02 14:08:48 +01001150 unsigned long timeout_start = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151
Eric Parisa3f07112008-11-05 12:47:09 -05001152 if (audit_initialized != AUDIT_INITIALIZED)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 return NULL;
1154
Dustin Kirklandc8edc802005-11-03 16:12:36 +00001155 if (unlikely(audit_filter_type(type)))
1156 return NULL;
1157
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001158 if (gfp_mask & __GFP_WAIT)
1159 reserve = 0;
1160 else
Daniel Walker5600b892007-10-18 03:06:10 -07001161 reserve = 5; /* Allow atomic callers to go up to five
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001162 entries over the normal backlog limit */
1163
1164 while (audit_backlog_limit
1165 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
Andrew Morton82919912013-01-11 14:32:11 -08001166 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) {
1167 unsigned long sleep_time;
David Woodhouseac4cec42005-07-02 14:08:48 +01001168
Andrew Morton82919912013-01-11 14:32:11 -08001169 sleep_time = timeout_start + audit_backlog_wait_time -
1170 jiffies;
1171 if ((long)sleep_time > 0)
1172 wait_for_auditd(sleep_time);
David Woodhouseac4cec42005-07-02 14:08:48 +01001173 continue;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001174 }
Eric Paris320f1b12008-01-23 22:55:05 -05001175 if (audit_rate_check() && printk_ratelimit())
David Woodhousefb19b4c2005-05-19 14:55:56 +01001176 printk(KERN_WARNING
1177 "audit: audit_backlog=%d > "
1178 "audit_backlog_limit=%d\n",
1179 skb_queue_len(&audit_skb_queue),
1180 audit_backlog_limit);
1181 audit_log_lost("backlog limit exceeded");
David Woodhouseac4cec42005-07-02 14:08:48 +01001182 audit_backlog_wait_time = audit_backlog_wait_overflow;
1183 wake_up(&audit_backlog_wait);
David Woodhousefb19b4c2005-05-19 14:55:56 +01001184 return NULL;
1185 }
1186
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001187 ab = audit_buffer_alloc(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001188 if (!ab) {
1189 audit_log_lost("out of memory in audit_log_start");
1190 return NULL;
1191 }
1192
David Woodhousebfb44962005-05-21 21:08:09 +01001193 audit_get_stamp(ab->ctx, &t, &serial);
Chris Wright197c69c2005-05-11 10:54:05 +01001194
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1196 t.tv_sec, t.tv_nsec/1000000, serial);
1197 return ab;
1198}
1199
Chris Wright8fc61152005-05-06 15:54:17 +01001200/**
Chris Wright5ac52f32005-05-06 15:54:53 +01001201 * audit_expand - expand skb in the audit buffer
Chris Wright8fc61152005-05-06 15:54:17 +01001202 * @ab: audit_buffer
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001203 * @extra: space to add at tail of the skb
Chris Wright8fc61152005-05-06 15:54:17 +01001204 *
1205 * Returns 0 (no space) on failed expansion, or available space if
1206 * successful.
1207 */
David Woodhousee3b926b2005-05-10 18:56:08 +01001208static inline int audit_expand(struct audit_buffer *ab, int extra)
Chris Wright8fc61152005-05-06 15:54:17 +01001209{
Chris Wright5ac52f32005-05-06 15:54:53 +01001210 struct sk_buff *skb = ab->skb;
Herbert Xu406a1d82008-01-28 20:47:09 -08001211 int oldtail = skb_tailroom(skb);
1212 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1213 int newtail = skb_tailroom(skb);
1214
Chris Wright5ac52f32005-05-06 15:54:53 +01001215 if (ret < 0) {
1216 audit_log_lost("out of memory in audit_expand");
Chris Wright8fc61152005-05-06 15:54:17 +01001217 return 0;
Chris Wright5ac52f32005-05-06 15:54:53 +01001218 }
Herbert Xu406a1d82008-01-28 20:47:09 -08001219
1220 skb->truesize += newtail - oldtail;
1221 return newtail;
Chris Wright8fc61152005-05-06 15:54:17 +01001222}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001224/*
1225 * Format an audit message into the audit buffer. If there isn't enough
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 * room in the audit buffer, more room will be allocated and vsnprint
1227 * will be called a second time. Currently, we assume that a printk
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001228 * can't format message larger than 1024 bytes, so we don't either.
1229 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1231 va_list args)
1232{
1233 int len, avail;
Chris Wright5ac52f32005-05-06 15:54:53 +01001234 struct sk_buff *skb;
David Woodhouseeecb0a72005-05-10 18:58:51 +01001235 va_list args2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236
1237 if (!ab)
1238 return;
1239
Chris Wright5ac52f32005-05-06 15:54:53 +01001240 BUG_ON(!ab->skb);
1241 skb = ab->skb;
1242 avail = skb_tailroom(skb);
1243 if (avail == 0) {
David Woodhousee3b926b2005-05-10 18:56:08 +01001244 avail = audit_expand(ab, AUDIT_BUFSIZ);
Chris Wright8fc61152005-05-06 15:54:17 +01001245 if (!avail)
1246 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 }
David Woodhouseeecb0a72005-05-10 18:58:51 +01001248 va_copy(args2, args);
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001249 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 if (len >= avail) {
1251 /* The printk buffer is 1024 bytes long, so if we get
1252 * here and AUDIT_BUFSIZ is at least 1024, then we can
1253 * log everything that printk could have logged. */
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001254 avail = audit_expand(ab,
1255 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
Chris Wright8fc61152005-05-06 15:54:17 +01001256 if (!avail)
Jesper Juhla0e86bd2012-01-08 22:44:29 +01001257 goto out_va_end;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001258 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259 }
Steve Grubb168b7172005-05-19 10:24:22 +01001260 if (len > 0)
1261 skb_put(skb, len);
Jesper Juhla0e86bd2012-01-08 22:44:29 +01001262out_va_end:
1263 va_end(args2);
Chris Wright8fc61152005-05-06 15:54:17 +01001264out:
1265 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266}
1267
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001268/**
1269 * audit_log_format - format a message into the audit buffer.
1270 * @ab: audit_buffer
1271 * @fmt: format string
1272 * @...: optional parameters matching @fmt string
1273 *
1274 * All the work is done in audit_log_vformat.
1275 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1277{
1278 va_list args;
1279
1280 if (!ab)
1281 return;
1282 va_start(args, fmt);
1283 audit_log_vformat(ab, fmt, args);
1284 va_end(args);
1285}
1286
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001287/**
1288 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1289 * @ab: the audit_buffer
1290 * @buf: buffer to convert to hex
1291 * @len: length of @buf to be converted
1292 *
1293 * No return value; failure to expand is silently ignored.
1294 *
1295 * This function will take the passed buf and convert it into a string of
1296 * ascii hex digits. The new string is placed onto the skb.
1297 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001298void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
Steve Grubb168b7172005-05-19 10:24:22 +01001299 size_t len)
83c7d092005-04-29 15:54:44 +01001300{
Steve Grubb168b7172005-05-19 10:24:22 +01001301 int i, avail, new_len;
1302 unsigned char *ptr;
1303 struct sk_buff *skb;
1304 static const unsigned char *hex = "0123456789ABCDEF";
83c7d092005-04-29 15:54:44 +01001305
Amy Griffis8ef2d302006-09-07 17:03:02 -04001306 if (!ab)
1307 return;
1308
Steve Grubb168b7172005-05-19 10:24:22 +01001309 BUG_ON(!ab->skb);
1310 skb = ab->skb;
1311 avail = skb_tailroom(skb);
1312 new_len = len<<1;
1313 if (new_len >= avail) {
1314 /* Round the buffer request up to the next multiple */
1315 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1316 avail = audit_expand(ab, new_len);
1317 if (!avail)
1318 return;
1319 }
1320
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001321 ptr = skb_tail_pointer(skb);
Steve Grubb168b7172005-05-19 10:24:22 +01001322 for (i=0; i<len; i++) {
1323 *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
1324 *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */
1325 }
1326 *ptr = 0;
1327 skb_put(skb, len << 1); /* new string is twice the old string */
83c7d092005-04-29 15:54:44 +01001328}
1329
Amy Griffis9c937dc2006-06-08 23:19:31 -04001330/*
1331 * Format a string of no more than slen characters into the audit buffer,
1332 * enclosed in quote marks.
1333 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001334void audit_log_n_string(struct audit_buffer *ab, const char *string,
1335 size_t slen)
Amy Griffis9c937dc2006-06-08 23:19:31 -04001336{
1337 int avail, new_len;
1338 unsigned char *ptr;
1339 struct sk_buff *skb;
1340
Amy Griffis8ef2d302006-09-07 17:03:02 -04001341 if (!ab)
1342 return;
1343
Amy Griffis9c937dc2006-06-08 23:19:31 -04001344 BUG_ON(!ab->skb);
1345 skb = ab->skb;
1346 avail = skb_tailroom(skb);
1347 new_len = slen + 3; /* enclosing quotes + null terminator */
1348 if (new_len > avail) {
1349 avail = audit_expand(ab, new_len);
1350 if (!avail)
1351 return;
1352 }
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001353 ptr = skb_tail_pointer(skb);
Amy Griffis9c937dc2006-06-08 23:19:31 -04001354 *ptr++ = '"';
1355 memcpy(ptr, string, slen);
1356 ptr += slen;
1357 *ptr++ = '"';
1358 *ptr = 0;
1359 skb_put(skb, slen + 2); /* don't include null terminator */
1360}
1361
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001362/**
Eric Parisde6bbd12008-01-07 14:31:58 -05001363 * audit_string_contains_control - does a string need to be logged in hex
Dave Jonesf706d5d2008-03-28 14:15:56 -07001364 * @string: string to be checked
1365 * @len: max length of the string to check
Eric Parisde6bbd12008-01-07 14:31:58 -05001366 */
1367int audit_string_contains_control(const char *string, size_t len)
1368{
1369 const unsigned char *p;
Miloslav Trmacb3897f52009-03-19 09:48:27 -04001370 for (p = string; p < (const unsigned char *)string + len; p++) {
Vesa-Matti J Kari1d6c9642008-07-23 00:06:13 +03001371 if (*p == '"' || *p < 0x21 || *p > 0x7e)
Eric Parisde6bbd12008-01-07 14:31:58 -05001372 return 1;
1373 }
1374 return 0;
1375}
1376
1377/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07001378 * audit_log_n_untrustedstring - log a string that may contain random characters
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001379 * @ab: audit_buffer
Dave Jonesf706d5d2008-03-28 14:15:56 -07001380 * @len: length of string (not including trailing null)
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001381 * @string: string to be logged
1382 *
1383 * This code will escape a string that is passed to it if the string
1384 * contains a control character, unprintable character, double quote mark,
Steve Grubb168b7172005-05-19 10:24:22 +01001385 * or a space. Unescaped strings will start and end with a double quote mark.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001386 * Strings that are escaped are printed in hex (2 digits per char).
Amy Griffis9c937dc2006-06-08 23:19:31 -04001387 *
1388 * The caller specifies the number of characters in the string to log, which may
1389 * or may not be the entire string.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001390 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001391void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1392 size_t len)
83c7d092005-04-29 15:54:44 +01001393{
Eric Parisde6bbd12008-01-07 14:31:58 -05001394 if (audit_string_contains_control(string, len))
Eric Parisb556f8a2008-04-18 10:12:59 -04001395 audit_log_n_hex(ab, string, len);
Eric Parisde6bbd12008-01-07 14:31:58 -05001396 else
Eric Parisb556f8a2008-04-18 10:12:59 -04001397 audit_log_n_string(ab, string, len);
83c7d092005-04-29 15:54:44 +01001398}
1399
Amy Griffis9c937dc2006-06-08 23:19:31 -04001400/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07001401 * audit_log_untrustedstring - log a string that may contain random characters
Amy Griffis9c937dc2006-06-08 23:19:31 -04001402 * @ab: audit_buffer
1403 * @string: string to be logged
1404 *
Miloslav Trmac522ed772007-07-15 23:40:56 -07001405 * Same as audit_log_n_untrustedstring(), except that strlen is used to
Amy Griffis9c937dc2006-06-08 23:19:31 -04001406 * determine string length.
1407 */
Eric Parisde6bbd12008-01-07 14:31:58 -05001408void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
Amy Griffis9c937dc2006-06-08 23:19:31 -04001409{
Eric Parisb556f8a2008-04-18 10:12:59 -04001410 audit_log_n_untrustedstring(ab, string, strlen(string));
Amy Griffis9c937dc2006-06-08 23:19:31 -04001411}
1412
Steve Grubb168b7172005-05-19 10:24:22 +01001413/* This is a helper-function to print the escaped d_path */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001414void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
Al Viro66b3fad2012-03-14 21:48:20 -04001415 const struct path *path)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001416{
Jan Blunck44707fd2008-02-14 19:38:33 -08001417 char *p, *pathname;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418
Chris Wright8fc61152005-05-06 15:54:17 +01001419 if (prefix)
Kees Cookc158a352012-01-06 14:07:10 -08001420 audit_log_format(ab, "%s", prefix);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421
Steve Grubb168b7172005-05-19 10:24:22 +01001422 /* We will allow 11 spaces for ' (deleted)' to be appended */
Jan Blunck44707fd2008-02-14 19:38:33 -08001423 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1424 if (!pathname) {
Eric Parisdef57542009-03-10 18:00:14 -04001425 audit_log_string(ab, "<no_memory>");
Steve Grubb168b7172005-05-19 10:24:22 +01001426 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427 }
Jan Blunckcf28b482008-02-14 19:38:44 -08001428 p = d_path(path, pathname, PATH_MAX+11);
Steve Grubb168b7172005-05-19 10:24:22 +01001429 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1430 /* FIXME: can we save some information here? */
Eric Parisdef57542009-03-10 18:00:14 -04001431 audit_log_string(ab, "<too_long>");
Daniel Walker5600b892007-10-18 03:06:10 -07001432 } else
Steve Grubb168b7172005-05-19 10:24:22 +01001433 audit_log_untrustedstring(ab, p);
Jan Blunck44707fd2008-02-14 19:38:33 -08001434 kfree(pathname);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435}
1436
Eric Paris9d960982009-06-11 14:31:37 -04001437void audit_log_key(struct audit_buffer *ab, char *key)
1438{
1439 audit_log_format(ab, " key=");
1440 if (key)
1441 audit_log_untrustedstring(ab, key);
1442 else
1443 audit_log_format(ab, "(null)");
1444}
1445
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001446/**
Kees Cooka51d9ea2012-07-25 17:29:08 -07001447 * audit_log_link_denied - report a link restriction denial
1448 * @operation: specific link opreation
1449 * @link: the path that triggered the restriction
1450 */
1451void audit_log_link_denied(const char *operation, struct path *link)
1452{
1453 struct audit_buffer *ab;
1454
1455 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1456 AUDIT_ANOM_LINK);
Sasha Levind1c7d972012-10-04 19:57:31 -04001457 if (!ab)
1458 return;
Kees Cooka51d9ea2012-07-25 17:29:08 -07001459 audit_log_format(ab, "op=%s action=denied", operation);
1460 audit_log_format(ab, " pid=%d comm=", current->pid);
1461 audit_log_untrustedstring(ab, current->comm);
1462 audit_log_d_path(ab, " path=", link);
1463 audit_log_format(ab, " dev=");
1464 audit_log_untrustedstring(ab, link->dentry->d_inode->i_sb->s_id);
1465 audit_log_format(ab, " ino=%lu", link->dentry->d_inode->i_ino);
1466 audit_log_end(ab);
1467}
1468
1469/**
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001470 * audit_log_end - end one audit record
1471 * @ab: the audit_buffer
1472 *
1473 * The netlink_* functions cannot be called inside an irq context, so
1474 * the audit buffer is placed on a queue and a tasklet is scheduled to
Linus Torvalds1da177e2005-04-16 15:20:36 -07001475 * remove them from the queue outside the irq context. May be called in
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001476 * any context.
1477 */
David Woodhouseb7d11252005-05-19 10:56:58 +01001478void audit_log_end(struct audit_buffer *ab)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001479{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001480 if (!ab)
1481 return;
1482 if (!audit_rate_check()) {
1483 audit_log_lost("rate limit exceeded");
1484 } else {
Steve Grubb8d07a672008-02-21 16:59:22 -05001485 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
Eric Parisf3d357b2008-04-18 10:02:28 -04001486 nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
1487
David Woodhouseb7d11252005-05-19 10:56:58 +01001488 if (audit_pid) {
David Woodhouseb7d11252005-05-19 10:56:58 +01001489 skb_queue_tail(&audit_skb_queue, ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001490 wake_up_interruptible(&kauditd_wait);
Eric Parisf3d357b2008-04-18 10:02:28 -04001491 } else {
Eric Paris038cbcf2009-06-11 14:31:35 -04001492 audit_printk_skb(ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001493 }
Eric Parisf3d357b2008-04-18 10:02:28 -04001494 ab->skb = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001495 }
Chris Wright16e19042005-05-06 15:53:34 +01001496 audit_buffer_free(ab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001497}
1498
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001499/**
1500 * audit_log - Log an audit record
1501 * @ctx: audit context
1502 * @gfp_mask: type of allocation
1503 * @type: audit message type
1504 * @fmt: format string to use
1505 * @...: variable parameters matching the format string
1506 *
1507 * This is a convenience function that calls audit_log_start,
1508 * audit_log_vformat, and audit_log_end. It may be called
1509 * in any context.
1510 */
Daniel Walker5600b892007-10-18 03:06:10 -07001511void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001512 const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513{
1514 struct audit_buffer *ab;
1515 va_list args;
1516
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001517 ab = audit_log_start(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001518 if (ab) {
1519 va_start(args, fmt);
1520 audit_log_vformat(ab, fmt, args);
1521 va_end(args);
1522 audit_log_end(ab);
1523 }
1524}
lorenzo@gnu.orgbf45da92006-03-09 00:33:47 +01001525
Mr Dash Four131ad622011-06-30 13:31:57 +02001526#ifdef CONFIG_SECURITY
1527/**
1528 * audit_log_secctx - Converts and logs SELinux context
1529 * @ab: audit_buffer
1530 * @secid: security number
1531 *
1532 * This is a helper function that calls security_secid_to_secctx to convert
1533 * secid to secctx and then adds the (converted) SELinux context to the audit
1534 * log by calling audit_log_format, thus also preventing leak of internal secid
1535 * to userspace. If secid cannot be converted audit_panic is called.
1536 */
1537void audit_log_secctx(struct audit_buffer *ab, u32 secid)
1538{
1539 u32 len;
1540 char *secctx;
1541
1542 if (security_secid_to_secctx(secid, &secctx, &len)) {
1543 audit_panic("Cannot convert secid to context");
1544 } else {
1545 audit_log_format(ab, " obj=%s", secctx);
1546 security_release_secctx(secctx, len);
1547 }
1548}
1549EXPORT_SYMBOL(audit_log_secctx);
1550#endif
1551
lorenzo@gnu.orgbf45da92006-03-09 00:33:47 +01001552EXPORT_SYMBOL(audit_log_start);
1553EXPORT_SYMBOL(audit_log_end);
1554EXPORT_SYMBOL(audit_log_format);
1555EXPORT_SYMBOL(audit_log);