Commit | Line | Data |
---|---|---|
85c8721f | 1 | /* audit.c -- Auditing support |
1da177e4 LT |
2 | * Gateway between the kernel (e.g., selinux) and the user-space audit daemon. |
3 | * System-call specific features have moved to auditsc.c | |
4 | * | |
6a01b07f | 5 | * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina. |
1da177e4 LT |
6 | * All Rights Reserved. |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
21 | * | |
22 | * Written by Rickard E. (Rik) Faith <faith@redhat.com> | |
23 | * | |
d7a96f3a | 24 | * Goals: 1) Integrate fully with Security Modules. |
1da177e4 LT |
25 | * 2) Minimal run-time overhead: |
26 | * a) Minimal when syscall auditing is disabled (audit_enable=0). | |
27 | * b) Small when syscall auditing is enabled and no audit record | |
28 | * is generated (defer as much work as possible to record | |
29 | * generation time): | |
30 | * i) context is allocated, | |
31 | * ii) names from getname are stored without a copy, and | |
32 | * iii) inode information stored from path_lookup. | |
33 | * 3) Ability to disable syscall auditing at boot time (audit=0). | |
34 | * 4) Usable by other parts of the kernel (if audit_log* is called, | |
35 | * then a syscall record will be generated automatically for the | |
36 | * current syscall). | |
37 | * 5) Netlink interface to user-space. | |
38 | * 6) Support low-overhead kernel-based filtering to minimize the | |
39 | * information that must be passed to user-space. | |
40 | * | |
85c8721f | 41 | * Example user-space utilities: http://people.redhat.com/sgrubb/audit/ |
1da177e4 LT |
42 | */ |
43 | ||
44 | #include <linux/init.h> | |
1da177e4 | 45 | #include <asm/types.h> |
60063497 | 46 | #include <linux/atomic.h> |
1da177e4 | 47 | #include <linux/mm.h> |
9984de1a | 48 | #include <linux/export.h> |
5a0e3ad6 | 49 | #include <linux/slab.h> |
b7d11258 DW |
50 | #include <linux/err.h> |
51 | #include <linux/kthread.h> | |
46e959ea | 52 | #include <linux/kernel.h> |
b24a30a7 | 53 | #include <linux/syscalls.h> |
1da177e4 LT |
54 | |
55 | #include <linux/audit.h> | |
56 | ||
57 | #include <net/sock.h> | |
93315ed6 | 58 | #include <net/netlink.h> |
1da177e4 | 59 | #include <linux/skbuff.h> |
131ad62d MDF |
60 | #ifdef CONFIG_SECURITY |
61 | #include <linux/security.h> | |
62 | #endif | |
7dfb7103 | 63 | #include <linux/freezer.h> |
522ed776 | 64 | #include <linux/tty.h> |
34e36d8e | 65 | #include <linux/pid_namespace.h> |
33faba7f | 66 | #include <net/netns/generic.h> |
3dc7e315 DG |
67 | |
68 | #include "audit.h" | |
1da177e4 | 69 | |
a3f07114 | 70 | /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
1da177e4 | 71 | * (Initialization happens after skb_init is called.) */ |
a3f07114 EP |
72 | #define AUDIT_DISABLED -1 |
73 | #define AUDIT_UNINITIALIZED 0 | |
74 | #define AUDIT_INITIALIZED 1 | |
1da177e4 LT |
75 | static int audit_initialized; |
76 | ||
1a6b9f23 EP |
77 | #define AUDIT_OFF 0 |
78 | #define AUDIT_ON 1 | |
79 | #define AUDIT_LOCKED 2 | |
1da177e4 | 80 | int audit_enabled; |
b593d384 | 81 | int audit_ever_enabled; |
1da177e4 | 82 | |
ae9d67af JE |
83 | EXPORT_SYMBOL_GPL(audit_enabled); |
84 | ||
1da177e4 LT |
85 | /* Default state when kernel boots without any parameters. */ |
86 | static int audit_default; | |
87 | ||
88 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
89 | static int audit_failure = AUDIT_FAIL_PRINTK; | |
90 | ||
75c0371a PE |
91 | /* |
92 | * If audit records are to be written to the netlink socket, audit_pid | |
15e47304 EB |
93 | * contains the pid of the auditd process and audit_nlk_portid contains |
94 | * the portid to use to send netlink messages to that process. | |
75c0371a | 95 | */ |
c2f0c7c3 | 96 | int audit_pid; |
f9441639 | 97 | static __u32 audit_nlk_portid; |
1da177e4 | 98 | |
b0dd25a8 | 99 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
100 | * to that number per second. This prevents DoS attacks, but results in |
101 | * audit records being dropped. */ | |
102 | static int audit_rate_limit; | |
103 | ||
104 | /* Number of outstanding audit_buffers allowed. */ | |
105 | static int audit_backlog_limit = 64; | |
e789e561 RGB |
106 | #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ) |
107 | static int audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; | |
ac4cec44 | 108 | static int audit_backlog_wait_overflow = 0; |
1da177e4 | 109 | |
c2f0c7c3 | 110 | /* The identity of the user shutting down the audit system. */ |
cca080d9 | 111 | kuid_t audit_sig_uid = INVALID_UID; |
c2f0c7c3 | 112 | pid_t audit_sig_pid = -1; |
e1396065 | 113 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 114 | |
1da177e4 LT |
115 | /* Records can be lost in several ways: |
116 | 0) [suppressed in audit_alloc] | |
117 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
118 | 2) out of memory in audit_log_move [alloc_skb] | |
119 | 3) suppressed due to audit_rate_limit | |
120 | 4) suppressed due to audit_backlog_limit | |
121 | */ | |
122 | static atomic_t audit_lost = ATOMIC_INIT(0); | |
123 | ||
124 | /* The netlink socket. */ | |
125 | static struct sock *audit_sock; | |
33faba7f | 126 | int audit_net_id; |
1da177e4 | 127 | |
f368c07d AG |
128 | /* Hash for inode-based rules */ |
129 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
130 | ||
b7d11258 | 131 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
1da177e4 LT |
132 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
133 | * being placed on the freelist). */ | |
1da177e4 | 134 | static DEFINE_SPINLOCK(audit_freelist_lock); |
b0dd25a8 | 135 | static int audit_freelist_count; |
1da177e4 LT |
136 | static LIST_HEAD(audit_freelist); |
137 | ||
b7d11258 | 138 | static struct sk_buff_head audit_skb_queue; |
f3d357b0 EP |
139 | /* queue of skbs to send to auditd when/if it comes back */ |
140 | static struct sk_buff_head audit_skb_hold_queue; | |
b7d11258 DW |
141 | static struct task_struct *kauditd_task; |
142 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
9ad9ad38 | 143 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 144 | |
b0fed402 EP |
145 | static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION, |
146 | .mask = -1, | |
147 | .features = 0, | |
148 | .lock = 0,}; | |
149 | ||
21b85c31 | 150 | static char *audit_feature_names[2] = { |
d040e5af | 151 | "only_unset_loginuid", |
21b85c31 | 152 | "loginuid_immutable", |
b0fed402 EP |
153 | }; |
154 | ||
155 | ||
f368c07d | 156 | /* Serialize requests from userspace. */ |
916d7576 | 157 | DEFINE_MUTEX(audit_cmd_mutex); |
1da177e4 LT |
158 | |
159 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
160 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
161 | * should be at least that large. */ | |
162 | #define AUDIT_BUFSIZ 1024 | |
163 | ||
164 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the | |
165 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ | |
166 | #define AUDIT_MAXFREE (2*NR_CPUS) | |
167 | ||
168 | /* The audit_buffer is used when formatting an audit record. The caller | |
169 | * locks briefly to get the record off the freelist or to allocate the | |
170 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
171 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
172 | * use simultaneously. */ | |
173 | struct audit_buffer { | |
174 | struct list_head list; | |
8fc6115c | 175 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 176 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 177 | gfp_t gfp_mask; |
1da177e4 LT |
178 | }; |
179 | ||
f09ac9db | 180 | struct audit_reply { |
f9441639 | 181 | __u32 portid; |
33faba7f | 182 | pid_t pid; |
f09ac9db EP |
183 | struct sk_buff *skb; |
184 | }; | |
185 | ||
f9441639 | 186 | static void audit_set_portid(struct audit_buffer *ab, __u32 portid) |
c0404993 | 187 | { |
50397bd1 EP |
188 | if (ab) { |
189 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); | |
f9441639 | 190 | nlh->nlmsg_pid = portid; |
50397bd1 | 191 | } |
c0404993 SG |
192 | } |
193 | ||
8c8570fb | 194 | void audit_panic(const char *message) |
1da177e4 LT |
195 | { |
196 | switch (audit_failure) | |
197 | { | |
198 | case AUDIT_FAIL_SILENT: | |
199 | break; | |
200 | case AUDIT_FAIL_PRINTK: | |
320f1b1e EP |
201 | if (printk_ratelimit()) |
202 | printk(KERN_ERR "audit: %s\n", message); | |
1da177e4 LT |
203 | break; |
204 | case AUDIT_FAIL_PANIC: | |
b29ee87e EP |
205 | /* test audit_pid since printk is always losey, why bother? */ |
206 | if (audit_pid) | |
207 | panic("audit: %s\n", message); | |
1da177e4 LT |
208 | break; |
209 | } | |
210 | } | |
211 | ||
212 | static inline int audit_rate_check(void) | |
213 | { | |
214 | static unsigned long last_check = 0; | |
215 | static int messages = 0; | |
216 | static DEFINE_SPINLOCK(lock); | |
217 | unsigned long flags; | |
218 | unsigned long now; | |
219 | unsigned long elapsed; | |
220 | int retval = 0; | |
221 | ||
222 | if (!audit_rate_limit) return 1; | |
223 | ||
224 | spin_lock_irqsave(&lock, flags); | |
225 | if (++messages < audit_rate_limit) { | |
226 | retval = 1; | |
227 | } else { | |
228 | now = jiffies; | |
229 | elapsed = now - last_check; | |
230 | if (elapsed > HZ) { | |
231 | last_check = now; | |
232 | messages = 0; | |
233 | retval = 1; | |
234 | } | |
235 | } | |
236 | spin_unlock_irqrestore(&lock, flags); | |
237 | ||
238 | return retval; | |
239 | } | |
240 | ||
b0dd25a8 RD |
241 | /** |
242 | * audit_log_lost - conditionally log lost audit message event | |
243 | * @message: the message stating reason for lost audit message | |
244 | * | |
245 | * Emit at least 1 message per second, even if audit_rate_check is | |
246 | * throttling. | |
247 | * Always increment the lost messages counter. | |
248 | */ | |
1da177e4 LT |
249 | void audit_log_lost(const char *message) |
250 | { | |
251 | static unsigned long last_msg = 0; | |
252 | static DEFINE_SPINLOCK(lock); | |
253 | unsigned long flags; | |
254 | unsigned long now; | |
255 | int print; | |
256 | ||
257 | atomic_inc(&audit_lost); | |
258 | ||
259 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
260 | ||
261 | if (!print) { | |
262 | spin_lock_irqsave(&lock, flags); | |
263 | now = jiffies; | |
264 | if (now - last_msg > HZ) { | |
265 | print = 1; | |
266 | last_msg = now; | |
267 | } | |
268 | spin_unlock_irqrestore(&lock, flags); | |
269 | } | |
270 | ||
271 | if (print) { | |
320f1b1e EP |
272 | if (printk_ratelimit()) |
273 | printk(KERN_WARNING | |
274 | "audit: audit_lost=%d audit_rate_limit=%d " | |
275 | "audit_backlog_limit=%d\n", | |
276 | atomic_read(&audit_lost), | |
277 | audit_rate_limit, | |
278 | audit_backlog_limit); | |
1da177e4 LT |
279 | audit_panic(message); |
280 | } | |
1da177e4 LT |
281 | } |
282 | ||
1a6b9f23 | 283 | static int audit_log_config_change(char *function_name, int new, int old, |
2532386f | 284 | int allow_changes) |
1da177e4 | 285 | { |
1a6b9f23 EP |
286 | struct audit_buffer *ab; |
287 | int rc = 0; | |
ce29b682 | 288 | |
1a6b9f23 | 289 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
0644ec0c KC |
290 | if (unlikely(!ab)) |
291 | return rc; | |
4d3fb709 EP |
292 | audit_log_format(ab, "%s=%d old=%d", function_name, new, old); |
293 | audit_log_session_info(ab); | |
b122c376 EP |
294 | rc = audit_log_task_context(ab); |
295 | if (rc) | |
296 | allow_changes = 0; /* Something weird, deny request */ | |
1a6b9f23 EP |
297 | audit_log_format(ab, " res=%d", allow_changes); |
298 | audit_log_end(ab); | |
6a01b07f | 299 | return rc; |
1da177e4 LT |
300 | } |
301 | ||
dc9eb698 | 302 | static int audit_do_config_change(char *function_name, int *to_change, int new) |
1da177e4 | 303 | { |
1a6b9f23 | 304 | int allow_changes, rc = 0, old = *to_change; |
6a01b07f SG |
305 | |
306 | /* check if we are locked */ | |
1a6b9f23 EP |
307 | if (audit_enabled == AUDIT_LOCKED) |
308 | allow_changes = 0; | |
6a01b07f | 309 | else |
1a6b9f23 | 310 | allow_changes = 1; |
ce29b682 | 311 | |
1a6b9f23 | 312 | if (audit_enabled != AUDIT_OFF) { |
dc9eb698 | 313 | rc = audit_log_config_change(function_name, new, old, allow_changes); |
1a6b9f23 EP |
314 | if (rc) |
315 | allow_changes = 0; | |
6a01b07f | 316 | } |
6a01b07f SG |
317 | |
318 | /* If we are allowed, make the change */ | |
1a6b9f23 EP |
319 | if (allow_changes == 1) |
320 | *to_change = new; | |
6a01b07f SG |
321 | /* Not allowed, update reason */ |
322 | else if (rc == 0) | |
323 | rc = -EPERM; | |
324 | return rc; | |
1da177e4 LT |
325 | } |
326 | ||
dc9eb698 | 327 | static int audit_set_rate_limit(int limit) |
1da177e4 | 328 | { |
dc9eb698 | 329 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); |
1a6b9f23 | 330 | } |
ce29b682 | 331 | |
dc9eb698 | 332 | static int audit_set_backlog_limit(int limit) |
1a6b9f23 | 333 | { |
dc9eb698 | 334 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); |
1a6b9f23 | 335 | } |
6a01b07f | 336 | |
dc9eb698 | 337 | static int audit_set_enabled(int state) |
1a6b9f23 | 338 | { |
b593d384 | 339 | int rc; |
1a6b9f23 EP |
340 | if (state < AUDIT_OFF || state > AUDIT_LOCKED) |
341 | return -EINVAL; | |
6a01b07f | 342 | |
dc9eb698 | 343 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
b593d384 EP |
344 | if (!rc) |
345 | audit_ever_enabled |= !!state; | |
346 | ||
347 | return rc; | |
1da177e4 LT |
348 | } |
349 | ||
dc9eb698 | 350 | static int audit_set_failure(int state) |
1da177e4 | 351 | { |
1da177e4 LT |
352 | if (state != AUDIT_FAIL_SILENT |
353 | && state != AUDIT_FAIL_PRINTK | |
354 | && state != AUDIT_FAIL_PANIC) | |
355 | return -EINVAL; | |
ce29b682 | 356 | |
dc9eb698 | 357 | return audit_do_config_change("audit_failure", &audit_failure, state); |
1da177e4 LT |
358 | } |
359 | ||
f3d357b0 EP |
360 | /* |
361 | * Queue skbs to be sent to auditd when/if it comes back. These skbs should | |
362 | * already have been sent via prink/syslog and so if these messages are dropped | |
363 | * it is not a huge concern since we already passed the audit_log_lost() | |
364 | * notification and stuff. This is just nice to get audit messages during | |
365 | * boot before auditd is running or messages generated while auditd is stopped. | |
366 | * This only holds messages is audit_default is set, aka booting with audit=1 | |
367 | * or building your kernel that way. | |
368 | */ | |
369 | static void audit_hold_skb(struct sk_buff *skb) | |
370 | { | |
371 | if (audit_default && | |
372 | skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit) | |
373 | skb_queue_tail(&audit_skb_hold_queue, skb); | |
374 | else | |
375 | kfree_skb(skb); | |
376 | } | |
377 | ||
038cbcf6 EP |
378 | /* |
379 | * For one reason or another this nlh isn't getting delivered to the userspace | |
380 | * audit daemon, just send it to printk. | |
381 | */ | |
382 | static void audit_printk_skb(struct sk_buff *skb) | |
383 | { | |
384 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 385 | char *data = nlmsg_data(nlh); |
038cbcf6 EP |
386 | |
387 | if (nlh->nlmsg_type != AUDIT_EOE) { | |
388 | if (printk_ratelimit()) | |
389 | printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data); | |
390 | else | |
391 | audit_log_lost("printk limit exceeded\n"); | |
392 | } | |
393 | ||
394 | audit_hold_skb(skb); | |
395 | } | |
396 | ||
f3d357b0 EP |
397 | static void kauditd_send_skb(struct sk_buff *skb) |
398 | { | |
399 | int err; | |
400 | /* take a reference in case we can't send it and we want to hold it */ | |
401 | skb_get(skb); | |
15e47304 | 402 | err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0); |
f3d357b0 | 403 | if (err < 0) { |
c9404c9c | 404 | BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */ |
f3d357b0 | 405 | printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); |
9db3b9bc | 406 | audit_log_lost("auditd disappeared\n"); |
f3d357b0 | 407 | audit_pid = 0; |
33faba7f | 408 | audit_sock = NULL; |
f3d357b0 EP |
409 | /* we might get lucky and get this in the next auditd */ |
410 | audit_hold_skb(skb); | |
411 | } else | |
412 | /* drop the extra reference if sent ok */ | |
70d4bf6d | 413 | consume_skb(skb); |
f3d357b0 EP |
414 | } |
415 | ||
b551d1d9 RGB |
416 | /* |
417 | * flush_hold_queue - empty the hold queue if auditd appears | |
418 | * | |
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 | static void flush_hold_queue(void) | |
b7d11258 DW |
432 | { |
433 | struct sk_buff *skb; | |
434 | ||
b551d1d9 RGB |
435 | if (!audit_default || !audit_pid) |
436 | return; | |
437 | ||
438 | skb = skb_dequeue(&audit_skb_hold_queue); | |
439 | if (likely(!skb)) | |
440 | return; | |
441 | ||
442 | while (skb && audit_pid) { | |
443 | kauditd_send_skb(skb); | |
444 | skb = skb_dequeue(&audit_skb_hold_queue); | |
445 | } | |
446 | ||
447 | /* | |
448 | * if auditd just disappeared but we | |
449 | * dequeued an skb we need to drop ref | |
450 | */ | |
451 | if (skb) | |
452 | consume_skb(skb); | |
453 | } | |
454 | ||
97a41e26 | 455 | static int kauditd_thread(void *dummy) |
b7d11258 | 456 | { |
83144186 | 457 | set_freezable(); |
4899b8b1 | 458 | while (!kthread_should_stop()) { |
3320c513 RGB |
459 | struct sk_buff *skb; |
460 | DECLARE_WAITQUEUE(wait, current); | |
461 | ||
b551d1d9 | 462 | flush_hold_queue(); |
f3d357b0 | 463 | |
b7d11258 | 464 | skb = skb_dequeue(&audit_skb_queue); |
db897319 | 465 | |
b7d11258 | 466 | if (skb) { |
db897319 DD |
467 | if (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit) |
468 | wake_up(&audit_backlog_wait); | |
f3d357b0 EP |
469 | if (audit_pid) |
470 | kauditd_send_skb(skb); | |
038cbcf6 EP |
471 | else |
472 | audit_printk_skb(skb); | |
3320c513 RGB |
473 | continue; |
474 | } | |
475 | set_current_state(TASK_INTERRUPTIBLE); | |
476 | add_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 477 | |
3320c513 RGB |
478 | if (!skb_queue_len(&audit_skb_queue)) { |
479 | try_to_freeze(); | |
480 | schedule(); | |
b7d11258 | 481 | } |
3320c513 RGB |
482 | |
483 | __set_current_state(TASK_RUNNING); | |
484 | remove_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 485 | } |
4899b8b1 | 486 | return 0; |
b7d11258 DW |
487 | } |
488 | ||
9044e6bc AV |
489 | int audit_send_list(void *_dest) |
490 | { | |
491 | struct audit_netlink_list *dest = _dest; | |
9044e6bc | 492 | struct sk_buff *skb; |
33faba7f RGB |
493 | struct net *net = get_net_ns_by_pid(dest->pid); |
494 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
9044e6bc AV |
495 | |
496 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
497 | mutex_lock(&audit_cmd_mutex); |
498 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
499 | |
500 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
33faba7f | 501 | netlink_unicast(aunet->nlsk, skb, dest->portid, 0); |
9044e6bc AV |
502 | |
503 | kfree(dest); | |
504 | ||
505 | return 0; | |
506 | } | |
507 | ||
f9441639 | 508 | struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done, |
b8800aa5 | 509 | int multi, const void *payload, int size) |
9044e6bc AV |
510 | { |
511 | struct sk_buff *skb; | |
512 | struct nlmsghdr *nlh; | |
9044e6bc AV |
513 | void *data; |
514 | int flags = multi ? NLM_F_MULTI : 0; | |
515 | int t = done ? NLMSG_DONE : type; | |
516 | ||
ee080e6c | 517 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
518 | if (!skb) |
519 | return NULL; | |
520 | ||
f9441639 | 521 | nlh = nlmsg_put(skb, portid, seq, t, size, flags); |
c64e66c6 DM |
522 | if (!nlh) |
523 | goto out_kfree_skb; | |
524 | data = nlmsg_data(nlh); | |
9044e6bc AV |
525 | memcpy(data, payload, size); |
526 | return skb; | |
527 | ||
c64e66c6 DM |
528 | out_kfree_skb: |
529 | kfree_skb(skb); | |
9044e6bc AV |
530 | return NULL; |
531 | } | |
532 | ||
f09ac9db EP |
533 | static int audit_send_reply_thread(void *arg) |
534 | { | |
535 | struct audit_reply *reply = (struct audit_reply *)arg; | |
33faba7f RGB |
536 | struct net *net = get_net_ns_by_pid(reply->pid); |
537 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
f09ac9db EP |
538 | |
539 | mutex_lock(&audit_cmd_mutex); | |
540 | mutex_unlock(&audit_cmd_mutex); | |
541 | ||
542 | /* Ignore failure. It'll only happen if the sender goes away, | |
543 | because our timeout is set to infinite. */ | |
33faba7f | 544 | netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0); |
f09ac9db EP |
545 | kfree(reply); |
546 | return 0; | |
547 | } | |
b0dd25a8 RD |
548 | /** |
549 | * audit_send_reply - send an audit reply message via netlink | |
f9441639 | 550 | * @portid: netlink port to which to send reply |
b0dd25a8 RD |
551 | * @seq: sequence number |
552 | * @type: audit message type | |
553 | * @done: done (last) flag | |
554 | * @multi: multi-part message flag | |
555 | * @payload: payload data | |
556 | * @size: payload size | |
557 | * | |
f9441639 | 558 | * Allocates an skb, builds the netlink message, and sends it to the port id. |
b0dd25a8 RD |
559 | * No failure notifications. |
560 | */ | |
f9441639 RGB |
561 | static void audit_send_reply(__u32 portid, int seq, int type, int done, |
562 | int multi, const void *payload, int size) | |
1da177e4 | 563 | { |
f09ac9db EP |
564 | struct sk_buff *skb; |
565 | struct task_struct *tsk; | |
566 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), | |
567 | GFP_KERNEL); | |
568 | ||
569 | if (!reply) | |
570 | return; | |
571 | ||
f9441639 | 572 | skb = audit_make_reply(portid, seq, type, done, multi, payload, size); |
1da177e4 | 573 | if (!skb) |
fcaf1eb8 | 574 | goto out; |
f09ac9db | 575 | |
f9441639 | 576 | reply->portid = portid; |
33faba7f | 577 | reply->pid = task_pid_vnr(current); |
f09ac9db EP |
578 | reply->skb = skb; |
579 | ||
580 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
fcaf1eb8 AM |
581 | if (!IS_ERR(tsk)) |
582 | return; | |
583 | kfree_skb(skb); | |
584 | out: | |
585 | kfree(reply); | |
1da177e4 LT |
586 | } |
587 | ||
588 | /* | |
589 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
590 | * control messages. | |
591 | */ | |
c7bdb545 | 592 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
593 | { |
594 | int err = 0; | |
595 | ||
34e36d8e EB |
596 | /* Only support the initial namespaces for now. */ |
597 | if ((current_user_ns() != &init_user_ns) || | |
598 | (task_active_pid_ns(current) != &init_pid_ns)) | |
599 | return -EPERM; | |
600 | ||
1da177e4 | 601 | switch (msg_type) { |
1da177e4 | 602 | case AUDIT_LIST: |
1da177e4 LT |
603 | case AUDIT_ADD: |
604 | case AUDIT_DEL: | |
18900909 EP |
605 | return -EOPNOTSUPP; |
606 | case AUDIT_GET: | |
607 | case AUDIT_SET: | |
b0fed402 EP |
608 | case AUDIT_GET_FEATURE: |
609 | case AUDIT_SET_FEATURE: | |
18900909 EP |
610 | case AUDIT_LIST_RULES: |
611 | case AUDIT_ADD_RULE: | |
93315ed6 | 612 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 613 | case AUDIT_SIGNAL_INFO: |
522ed776 MT |
614 | case AUDIT_TTY_GET: |
615 | case AUDIT_TTY_SET: | |
74c3cbe3 AV |
616 | case AUDIT_TRIM: |
617 | case AUDIT_MAKE_EQUIV: | |
fd778461 | 618 | if (!capable(CAP_AUDIT_CONTROL)) |
1da177e4 LT |
619 | err = -EPERM; |
620 | break; | |
05474106 | 621 | case AUDIT_USER: |
039b6b3e RD |
622 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
623 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
fd778461 | 624 | if (!capable(CAP_AUDIT_WRITE)) |
1da177e4 LT |
625 | err = -EPERM; |
626 | break; | |
627 | default: /* bad msg */ | |
628 | err = -EINVAL; | |
629 | } | |
630 | ||
631 | return err; | |
632 | } | |
633 | ||
dc9eb698 | 634 | static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) |
50397bd1 EP |
635 | { |
636 | int rc = 0; | |
dc9eb698 | 637 | uid_t uid = from_kuid(&init_user_ns, current_uid()); |
50397bd1 | 638 | |
0868a5e1 | 639 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) { |
50397bd1 EP |
640 | *ab = NULL; |
641 | return rc; | |
642 | } | |
643 | ||
644 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); | |
0644ec0c KC |
645 | if (unlikely(!*ab)) |
646 | return rc; | |
4d3fb709 EP |
647 | audit_log_format(*ab, "pid=%d uid=%u", task_tgid_vnr(current), uid); |
648 | audit_log_session_info(*ab); | |
b122c376 | 649 | audit_log_task_context(*ab); |
50397bd1 EP |
650 | |
651 | return rc; | |
652 | } | |
653 | ||
b0fed402 EP |
654 | int is_audit_feature_set(int i) |
655 | { | |
656 | return af.features & AUDIT_FEATURE_TO_MASK(i); | |
657 | } | |
658 | ||
659 | ||
660 | static int audit_get_feature(struct sk_buff *skb) | |
661 | { | |
662 | u32 seq; | |
663 | ||
664 | seq = nlmsg_hdr(skb)->nlmsg_seq; | |
665 | ||
666 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, | |
667 | &af, sizeof(af)); | |
668 | ||
669 | return 0; | |
670 | } | |
671 | ||
672 | static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature, | |
673 | u32 old_lock, u32 new_lock, int res) | |
674 | { | |
675 | struct audit_buffer *ab; | |
676 | ||
677 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE); | |
678 | audit_log_format(ab, "feature=%s new=%d old=%d old_lock=%d new_lock=%d res=%d", | |
679 | audit_feature_names[which], !!old_feature, !!new_feature, | |
680 | !!old_lock, !!new_lock, res); | |
681 | audit_log_end(ab); | |
682 | } | |
683 | ||
684 | static int audit_set_feature(struct sk_buff *skb) | |
685 | { | |
686 | struct audit_features *uaf; | |
687 | int i; | |
688 | ||
689 | BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > sizeof(audit_feature_names)/sizeof(audit_feature_names[0])); | |
690 | uaf = nlmsg_data(nlmsg_hdr(skb)); | |
691 | ||
692 | /* if there is ever a version 2 we should handle that here */ | |
693 | ||
694 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
695 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
696 | u32 old_feature, new_feature, old_lock, new_lock; | |
697 | ||
698 | /* if we are not changing this feature, move along */ | |
699 | if (!(feature & uaf->mask)) | |
700 | continue; | |
701 | ||
702 | old_feature = af.features & feature; | |
703 | new_feature = uaf->features & feature; | |
704 | new_lock = (uaf->lock | af.lock) & feature; | |
705 | old_lock = af.lock & feature; | |
706 | ||
707 | /* are we changing a locked feature? */ | |
708 | if ((af.lock & feature) && (new_feature != old_feature)) { | |
709 | audit_log_feature_change(i, old_feature, new_feature, | |
710 | old_lock, new_lock, 0); | |
711 | return -EPERM; | |
712 | } | |
713 | } | |
714 | /* nothing invalid, do the changes */ | |
715 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
716 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
717 | u32 old_feature, new_feature, old_lock, new_lock; | |
718 | ||
719 | /* if we are not changing this feature, move along */ | |
720 | if (!(feature & uaf->mask)) | |
721 | continue; | |
722 | ||
723 | old_feature = af.features & feature; | |
724 | new_feature = uaf->features & feature; | |
725 | old_lock = af.lock & feature; | |
726 | new_lock = (uaf->lock | af.lock) & feature; | |
727 | ||
728 | if (new_feature != old_feature) | |
729 | audit_log_feature_change(i, old_feature, new_feature, | |
730 | old_lock, new_lock, 1); | |
731 | ||
732 | if (new_feature) | |
733 | af.features |= feature; | |
734 | else | |
735 | af.features &= ~feature; | |
736 | af.lock |= new_lock; | |
737 | } | |
738 | ||
739 | return 0; | |
740 | } | |
741 | ||
1da177e4 LT |
742 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
743 | { | |
dc9eb698 | 744 | u32 seq; |
1da177e4 LT |
745 | void *data; |
746 | struct audit_status *status_get, status_set; | |
747 | int err; | |
c0404993 | 748 | struct audit_buffer *ab; |
1da177e4 | 749 | u16 msg_type = nlh->nlmsg_type; |
e1396065 | 750 | struct audit_sig_info *sig_data; |
50397bd1 | 751 | char *ctx = NULL; |
e1396065 | 752 | u32 len; |
1da177e4 | 753 | |
c7bdb545 | 754 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
755 | if (err) |
756 | return err; | |
757 | ||
b0dd25a8 RD |
758 | /* As soon as there's any sign of userspace auditd, |
759 | * start kauditd to talk to it */ | |
13f51e1c | 760 | if (!kauditd_task) { |
b7d11258 | 761 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
13f51e1c G |
762 | if (IS_ERR(kauditd_task)) { |
763 | err = PTR_ERR(kauditd_task); | |
764 | kauditd_task = NULL; | |
765 | return err; | |
766 | } | |
b7d11258 | 767 | } |
1da177e4 | 768 | seq = nlh->nlmsg_seq; |
c64e66c6 | 769 | data = nlmsg_data(nlh); |
1da177e4 LT |
770 | |
771 | switch (msg_type) { | |
772 | case AUDIT_GET: | |
e13f91e3 | 773 | memset(&status_set, 0, sizeof(status_set)); |
1da177e4 LT |
774 | status_set.enabled = audit_enabled; |
775 | status_set.failure = audit_failure; | |
776 | status_set.pid = audit_pid; | |
777 | status_set.rate_limit = audit_rate_limit; | |
778 | status_set.backlog_limit = audit_backlog_limit; | |
779 | status_set.lost = atomic_read(&audit_lost); | |
b7d11258 | 780 | status_set.backlog = skb_queue_len(&audit_skb_queue); |
15e47304 | 781 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, |
1da177e4 LT |
782 | &status_set, sizeof(status_set)); |
783 | break; | |
784 | case AUDIT_SET: | |
4d8fe737 | 785 | if (nlmsg_len(nlh) < sizeof(struct audit_status)) |
1da177e4 LT |
786 | return -EINVAL; |
787 | status_get = (struct audit_status *)data; | |
788 | if (status_get->mask & AUDIT_STATUS_ENABLED) { | |
dc9eb698 | 789 | err = audit_set_enabled(status_get->enabled); |
20c6aaa3 | 790 | if (err < 0) |
791 | return err; | |
1da177e4 LT |
792 | } |
793 | if (status_get->mask & AUDIT_STATUS_FAILURE) { | |
dc9eb698 | 794 | err = audit_set_failure(status_get->failure); |
20c6aaa3 | 795 | if (err < 0) |
796 | return err; | |
1da177e4 LT |
797 | } |
798 | if (status_get->mask & AUDIT_STATUS_PID) { | |
1a6b9f23 EP |
799 | int new_pid = status_get->pid; |
800 | ||
801 | if (audit_enabled != AUDIT_OFF) | |
dc9eb698 | 802 | audit_log_config_change("audit_pid", new_pid, audit_pid, 1); |
1a6b9f23 | 803 | audit_pid = new_pid; |
15e47304 | 804 | audit_nlk_portid = NETLINK_CB(skb).portid; |
33faba7f | 805 | audit_sock = NETLINK_CB(skb).sk; |
1da177e4 | 806 | } |
20c6aaa3 | 807 | if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) { |
dc9eb698 | 808 | err = audit_set_rate_limit(status_get->rate_limit); |
20c6aaa3 | 809 | if (err < 0) |
810 | return err; | |
811 | } | |
1da177e4 | 812 | if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) |
dc9eb698 | 813 | err = audit_set_backlog_limit(status_get->backlog_limit); |
1da177e4 | 814 | break; |
b0fed402 EP |
815 | case AUDIT_GET_FEATURE: |
816 | err = audit_get_feature(skb); | |
817 | if (err) | |
818 | return err; | |
819 | break; | |
820 | case AUDIT_SET_FEATURE: | |
821 | err = audit_set_feature(skb); | |
822 | if (err) | |
823 | return err; | |
824 | break; | |
05474106 | 825 | case AUDIT_USER: |
039b6b3e RD |
826 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
827 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
828 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
829 | return 0; | |
830 | ||
62062cf8 | 831 | err = audit_filter_user(msg_type); |
4a4cd633 DW |
832 | if (err == 1) { |
833 | err = 0; | |
522ed776 | 834 | if (msg_type == AUDIT_USER_TTY) { |
152f497b | 835 | err = tty_audit_push_current(); |
522ed776 MT |
836 | if (err) |
837 | break; | |
838 | } | |
dc9eb698 | 839 | audit_log_common_recv_msg(&ab, msg_type); |
50397bd1 | 840 | if (msg_type != AUDIT_USER_TTY) |
b50eba7e RGB |
841 | audit_log_format(ab, " msg='%.*s'", |
842 | AUDIT_MESSAGE_TEXT_MAX, | |
50397bd1 EP |
843 | (char *)data); |
844 | else { | |
845 | int size; | |
846 | ||
f7616102 | 847 | audit_log_format(ab, " data="); |
50397bd1 | 848 | size = nlmsg_len(nlh); |
55ad2f8d MT |
849 | if (size > 0 && |
850 | ((unsigned char *)data)[size - 1] == '\0') | |
851 | size--; | |
b556f8ad | 852 | audit_log_n_untrustedstring(ab, data, size); |
4a4cd633 | 853 | } |
f9441639 | 854 | audit_set_portid(ab, NETLINK_CB(skb).portid); |
50397bd1 | 855 | audit_log_end(ab); |
0f45aa18 | 856 | } |
1da177e4 | 857 | break; |
93315ed6 AG |
858 | case AUDIT_ADD_RULE: |
859 | case AUDIT_DEL_RULE: | |
860 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
861 | return -EINVAL; | |
1a6b9f23 | 862 | if (audit_enabled == AUDIT_LOCKED) { |
dc9eb698 EP |
863 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
864 | audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); | |
50397bd1 | 865 | audit_log_end(ab); |
6a01b07f SG |
866 | return -EPERM; |
867 | } | |
93315ed6 AG |
868 | /* fallthrough */ |
869 | case AUDIT_LIST_RULES: | |
15e47304 | 870 | err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid, |
dc9eb698 | 871 | seq, data, nlmsg_len(nlh)); |
1da177e4 | 872 | break; |
74c3cbe3 AV |
873 | case AUDIT_TRIM: |
874 | audit_trim_trees(); | |
dc9eb698 | 875 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
74c3cbe3 AV |
876 | audit_log_format(ab, " op=trim res=1"); |
877 | audit_log_end(ab); | |
878 | break; | |
879 | case AUDIT_MAKE_EQUIV: { | |
880 | void *bufp = data; | |
881 | u32 sizes[2]; | |
7719e437 | 882 | size_t msglen = nlmsg_len(nlh); |
74c3cbe3 AV |
883 | char *old, *new; |
884 | ||
885 | err = -EINVAL; | |
7719e437 | 886 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
887 | break; |
888 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
889 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
890 | msglen -= 2 * sizeof(u32); |
891 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
892 | if (IS_ERR(old)) { |
893 | err = PTR_ERR(old); | |
894 | break; | |
895 | } | |
7719e437 | 896 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
897 | if (IS_ERR(new)) { |
898 | err = PTR_ERR(new); | |
899 | kfree(old); | |
900 | break; | |
901 | } | |
902 | /* OK, here comes... */ | |
903 | err = audit_tag_tree(old, new); | |
904 | ||
dc9eb698 | 905 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
50397bd1 | 906 | |
74c3cbe3 AV |
907 | audit_log_format(ab, " op=make_equiv old="); |
908 | audit_log_untrustedstring(ab, old); | |
909 | audit_log_format(ab, " new="); | |
910 | audit_log_untrustedstring(ab, new); | |
911 | audit_log_format(ab, " res=%d", !err); | |
912 | audit_log_end(ab); | |
913 | kfree(old); | |
914 | kfree(new); | |
915 | break; | |
916 | } | |
c2f0c7c3 | 917 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
918 | len = 0; |
919 | if (audit_sig_sid) { | |
920 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
921 | if (err) | |
922 | return err; | |
923 | } | |
e1396065 AV |
924 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
925 | if (!sig_data) { | |
939cbf26 EP |
926 | if (audit_sig_sid) |
927 | security_release_secctx(ctx, len); | |
e1396065 AV |
928 | return -ENOMEM; |
929 | } | |
cca080d9 | 930 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
e1396065 | 931 | sig_data->pid = audit_sig_pid; |
939cbf26 EP |
932 | if (audit_sig_sid) { |
933 | memcpy(sig_data->ctx, ctx, len); | |
934 | security_release_secctx(ctx, len); | |
935 | } | |
15e47304 | 936 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO, |
e1396065 AV |
937 | 0, 0, sig_data, sizeof(*sig_data) + len); |
938 | kfree(sig_data); | |
c2f0c7c3 | 939 | break; |
522ed776 MT |
940 | case AUDIT_TTY_GET: { |
941 | struct audit_tty_status s; | |
8aa14b64 EB |
942 | struct task_struct *tsk = current; |
943 | ||
7173c54e | 944 | spin_lock(&tsk->sighand->siglock); |
b95d77fe | 945 | s.enabled = tsk->signal->audit_tty; |
46e959ea | 946 | s.log_passwd = tsk->signal->audit_tty_log_passwd; |
7173c54e | 947 | spin_unlock(&tsk->sighand->siglock); |
8aa14b64 | 948 | |
aecdc33e | 949 | audit_send_reply(NETLINK_CB(skb).portid, seq, |
8aa14b64 | 950 | AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
522ed776 MT |
951 | break; |
952 | } | |
953 | case AUDIT_TTY_SET: { | |
46e959ea | 954 | struct audit_tty_status s; |
8aa14b64 | 955 | struct task_struct *tsk = current; |
522ed776 | 956 | |
46e959ea RGB |
957 | memset(&s, 0, sizeof(s)); |
958 | /* guard against past and future API changes */ | |
4d8fe737 | 959 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); |
46e959ea RGB |
960 | if ((s.enabled != 0 && s.enabled != 1) || |
961 | (s.log_passwd != 0 && s.log_passwd != 1)) | |
522ed776 | 962 | return -EINVAL; |
8aa14b64 | 963 | |
7173c54e | 964 | spin_lock(&tsk->sighand->siglock); |
46e959ea RGB |
965 | tsk->signal->audit_tty = s.enabled; |
966 | tsk->signal->audit_tty_log_passwd = s.log_passwd; | |
7173c54e | 967 | spin_unlock(&tsk->sighand->siglock); |
522ed776 MT |
968 | break; |
969 | } | |
1da177e4 LT |
970 | default: |
971 | err = -EINVAL; | |
972 | break; | |
973 | } | |
974 | ||
975 | return err < 0 ? err : 0; | |
976 | } | |
977 | ||
b0dd25a8 | 978 | /* |
ea7ae60b EP |
979 | * Get message from skb. Each message is processed by audit_receive_msg. |
980 | * Malformed skbs with wrong length are discarded silently. | |
b0dd25a8 | 981 | */ |
2a0a6ebe | 982 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 | 983 | { |
ea7ae60b EP |
984 | struct nlmsghdr *nlh; |
985 | /* | |
94191213 | 986 | * len MUST be signed for nlmsg_next to be able to dec it below 0 |
ea7ae60b EP |
987 | * if the nlmsg_len was not aligned |
988 | */ | |
989 | int len; | |
990 | int err; | |
991 | ||
992 | nlh = nlmsg_hdr(skb); | |
993 | len = skb->len; | |
994 | ||
94191213 | 995 | while (nlmsg_ok(nlh, len)) { |
ea7ae60b EP |
996 | err = audit_receive_msg(skb, nlh); |
997 | /* if err or if this message says it wants a response */ | |
998 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
1da177e4 | 999 | netlink_ack(skb, nlh, err); |
ea7ae60b | 1000 | |
2851da57 | 1001 | nlh = nlmsg_next(nlh, &len); |
1da177e4 | 1002 | } |
1da177e4 LT |
1003 | } |
1004 | ||
1005 | /* Receive messages from netlink socket. */ | |
cd40b7d3 | 1006 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 1007 | { |
f368c07d | 1008 | mutex_lock(&audit_cmd_mutex); |
cd40b7d3 | 1009 | audit_receive_skb(skb); |
f368c07d | 1010 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
1011 | } |
1012 | ||
33faba7f | 1013 | static int __net_init audit_net_init(struct net *net) |
1da177e4 | 1014 | { |
a31f2d17 PNA |
1015 | struct netlink_kernel_cfg cfg = { |
1016 | .input = audit_receive, | |
1017 | }; | |
f368c07d | 1018 | |
33faba7f RGB |
1019 | struct audit_net *aunet = net_generic(net, audit_net_id); |
1020 | ||
1021 | pr_info("audit: initializing netlink socket in namespace\n"); | |
1022 | ||
1023 | aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg); | |
1024 | if (aunet->nlsk == NULL) | |
1025 | return -ENOMEM; | |
1026 | if (!aunet->nlsk) | |
1027 | audit_panic("cannot initialize netlink socket in namespace"); | |
1028 | else | |
1029 | aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; | |
1030 | return 0; | |
1031 | } | |
1032 | ||
1033 | static void __net_exit audit_net_exit(struct net *net) | |
1034 | { | |
1035 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
1036 | struct sock *sock = aunet->nlsk; | |
1037 | if (sock == audit_sock) { | |
1038 | audit_pid = 0; | |
1039 | audit_sock = NULL; | |
1040 | } | |
1041 | ||
1042 | rcu_assign_pointer(aunet->nlsk, NULL); | |
1043 | synchronize_net(); | |
1044 | netlink_kernel_release(sock); | |
1045 | } | |
1046 | ||
1047 | static struct pernet_operations __net_initdata audit_net_ops = { | |
1048 | .init = audit_net_init, | |
1049 | .exit = audit_net_exit, | |
1050 | .id = &audit_net_id, | |
1051 | .size = sizeof(struct audit_net), | |
1052 | }; | |
1053 | ||
1054 | /* Initialize audit support at boot time. */ | |
1055 | static int __init audit_init(void) | |
1056 | { | |
1057 | int i; | |
1058 | ||
a3f07114 EP |
1059 | if (audit_initialized == AUDIT_DISABLED) |
1060 | return 0; | |
1061 | ||
33faba7f | 1062 | pr_info("audit: initializing netlink subsys (%s)\n", |
1da177e4 | 1063 | audit_default ? "enabled" : "disabled"); |
33faba7f | 1064 | register_pernet_subsys(&audit_net_ops); |
1da177e4 | 1065 | |
b7d11258 | 1066 | skb_queue_head_init(&audit_skb_queue); |
f3d357b0 | 1067 | skb_queue_head_init(&audit_skb_hold_queue); |
a3f07114 | 1068 | audit_initialized = AUDIT_INITIALIZED; |
1da177e4 | 1069 | audit_enabled = audit_default; |
b593d384 | 1070 | audit_ever_enabled |= !!audit_default; |
3dc7e315 | 1071 | |
9ad9ad38 | 1072 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
f368c07d | 1073 | |
f368c07d AG |
1074 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
1075 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 1076 | |
1da177e4 LT |
1077 | return 0; |
1078 | } | |
1da177e4 LT |
1079 | __initcall(audit_init); |
1080 | ||
1081 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
1082 | static int __init audit_enable(char *str) | |
1083 | { | |
1084 | audit_default = !!simple_strtol(str, NULL, 0); | |
a3f07114 EP |
1085 | if (!audit_default) |
1086 | audit_initialized = AUDIT_DISABLED; | |
1087 | ||
1088 | printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled"); | |
1089 | ||
1090 | if (audit_initialized == AUDIT_INITIALIZED) { | |
1da177e4 | 1091 | audit_enabled = audit_default; |
b593d384 | 1092 | audit_ever_enabled |= !!audit_default; |
a3f07114 EP |
1093 | } else if (audit_initialized == AUDIT_UNINITIALIZED) { |
1094 | printk(" (after initialization)"); | |
1095 | } else { | |
1096 | printk(" (until reboot)"); | |
b593d384 | 1097 | } |
a3f07114 EP |
1098 | printk("\n"); |
1099 | ||
9b41046c | 1100 | return 1; |
1da177e4 | 1101 | } |
1da177e4 LT |
1102 | __setup("audit=", audit_enable); |
1103 | ||
f910fde7 RGB |
1104 | /* Process kernel command-line parameter at boot time. |
1105 | * audit_backlog_limit=<n> */ | |
1106 | static int __init audit_backlog_limit_set(char *str) | |
1107 | { | |
1108 | long int audit_backlog_limit_arg; | |
1109 | pr_info("audit_backlog_limit: "); | |
1110 | if (kstrtol(str, 0, &audit_backlog_limit_arg)) { | |
1111 | printk("using default of %d, unable to parse %s\n", | |
1112 | audit_backlog_limit, str); | |
1113 | return 1; | |
1114 | } | |
1115 | if (audit_backlog_limit_arg >= 0) | |
1116 | audit_backlog_limit = (int)audit_backlog_limit_arg; | |
1117 | printk("%d\n", audit_backlog_limit); | |
1118 | ||
1119 | return 1; | |
1120 | } | |
1121 | __setup("audit_backlog_limit=", audit_backlog_limit_set); | |
1122 | ||
16e1904e CW |
1123 | static void audit_buffer_free(struct audit_buffer *ab) |
1124 | { | |
1125 | unsigned long flags; | |
1126 | ||
8fc6115c CW |
1127 | if (!ab) |
1128 | return; | |
1129 | ||
5ac52f33 CW |
1130 | if (ab->skb) |
1131 | kfree_skb(ab->skb); | |
b7d11258 | 1132 | |
16e1904e | 1133 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 1134 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 1135 | kfree(ab); |
5d136a01 SH |
1136 | else { |
1137 | audit_freelist_count++; | |
16e1904e | 1138 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 1139 | } |
16e1904e CW |
1140 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
1141 | } | |
1142 | ||
c0404993 | 1143 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 1144 | gfp_t gfp_mask, int type) |
16e1904e CW |
1145 | { |
1146 | unsigned long flags; | |
1147 | struct audit_buffer *ab = NULL; | |
c0404993 | 1148 | struct nlmsghdr *nlh; |
16e1904e CW |
1149 | |
1150 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
1151 | if (!list_empty(&audit_freelist)) { | |
1152 | ab = list_entry(audit_freelist.next, | |
1153 | struct audit_buffer, list); | |
1154 | list_del(&ab->list); | |
1155 | --audit_freelist_count; | |
1156 | } | |
1157 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
1158 | ||
1159 | if (!ab) { | |
4332bdd3 | 1160 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 1161 | if (!ab) |
8fc6115c | 1162 | goto err; |
16e1904e | 1163 | } |
8fc6115c | 1164 | |
b7d11258 | 1165 | ab->ctx = ctx; |
9ad9ad38 | 1166 | ab->gfp_mask = gfp_mask; |
ee080e6c EP |
1167 | |
1168 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1169 | if (!ab->skb) | |
c64e66c6 | 1170 | goto err; |
ee080e6c | 1171 | |
c64e66c6 DM |
1172 | nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); |
1173 | if (!nlh) | |
1174 | goto out_kfree_skb; | |
ee080e6c | 1175 | |
16e1904e | 1176 | return ab; |
ee080e6c | 1177 | |
c64e66c6 | 1178 | out_kfree_skb: |
ee080e6c EP |
1179 | kfree_skb(ab->skb); |
1180 | ab->skb = NULL; | |
8fc6115c CW |
1181 | err: |
1182 | audit_buffer_free(ab); | |
1183 | return NULL; | |
16e1904e | 1184 | } |
1da177e4 | 1185 | |
b0dd25a8 RD |
1186 | /** |
1187 | * audit_serial - compute a serial number for the audit record | |
1188 | * | |
1189 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1190 | * written to user-space as soon as they are generated, so a complete |
1191 | * audit record may be written in several pieces. The timestamp of the | |
1192 | * record and this serial number are used by the user-space tools to | |
1193 | * determine which pieces belong to the same audit record. The | |
1194 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1195 | * syscall entry to syscall exit. | |
1196 | * | |
bfb4496e DW |
1197 | * NOTE: Another possibility is to store the formatted records off the |
1198 | * audit context (for those records that have a context), and emit them | |
1199 | * all at syscall exit. However, this could delay the reporting of | |
1200 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1201 | * halts). |
1202 | */ | |
bfb4496e DW |
1203 | unsigned int audit_serial(void) |
1204 | { | |
34af946a | 1205 | static DEFINE_SPINLOCK(serial_lock); |
d5b454f2 DW |
1206 | static unsigned int serial = 0; |
1207 | ||
1208 | unsigned long flags; | |
1209 | unsigned int ret; | |
bfb4496e | 1210 | |
d5b454f2 | 1211 | spin_lock_irqsave(&serial_lock, flags); |
bfb4496e | 1212 | do { |
ce625a80 DW |
1213 | ret = ++serial; |
1214 | } while (unlikely(!ret)); | |
d5b454f2 | 1215 | spin_unlock_irqrestore(&serial_lock, flags); |
bfb4496e | 1216 | |
d5b454f2 | 1217 | return ret; |
bfb4496e DW |
1218 | } |
1219 | ||
5600b892 | 1220 | static inline void audit_get_stamp(struct audit_context *ctx, |
bfb4496e DW |
1221 | struct timespec *t, unsigned int *serial) |
1222 | { | |
48887e63 | 1223 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
bfb4496e DW |
1224 | *t = CURRENT_TIME; |
1225 | *serial = audit_serial(); | |
1226 | } | |
1227 | } | |
1228 | ||
82919919 AM |
1229 | /* |
1230 | * Wait for auditd to drain the queue a little | |
1231 | */ | |
ae887e0b | 1232 | static unsigned long wait_for_auditd(unsigned long sleep_time) |
82919919 | 1233 | { |
ae887e0b | 1234 | unsigned long timeout = sleep_time; |
82919919 | 1235 | DECLARE_WAITQUEUE(wait, current); |
f000cfdd | 1236 | set_current_state(TASK_UNINTERRUPTIBLE); |
7ecf69bf | 1237 | add_wait_queue_exclusive(&audit_backlog_wait, &wait); |
82919919 AM |
1238 | |
1239 | if (audit_backlog_limit && | |
1240 | skb_queue_len(&audit_skb_queue) > audit_backlog_limit) | |
ae887e0b | 1241 | timeout = schedule_timeout(sleep_time); |
82919919 AM |
1242 | |
1243 | __set_current_state(TASK_RUNNING); | |
1244 | remove_wait_queue(&audit_backlog_wait, &wait); | |
ae887e0b RGB |
1245 | |
1246 | return timeout; | |
82919919 AM |
1247 | } |
1248 | ||
b0dd25a8 RD |
1249 | /** |
1250 | * audit_log_start - obtain an audit buffer | |
1251 | * @ctx: audit_context (may be NULL) | |
1252 | * @gfp_mask: type of allocation | |
1253 | * @type: audit message type | |
1254 | * | |
1255 | * Returns audit_buffer pointer on success or NULL on error. | |
1256 | * | |
1257 | * Obtain an audit buffer. This routine does locking to obtain the | |
1258 | * audit buffer, but then no locking is required for calls to | |
1259 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1260 | * syscall, then the syscall is marked as auditable and an audit record | |
1261 | * will be written at syscall exit. If there is no associated task, then | |
1262 | * task context (ctx) should be NULL. | |
1263 | */ | |
9796fdd8 | 1264 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1265 | int type) |
1da177e4 LT |
1266 | { |
1267 | struct audit_buffer *ab = NULL; | |
1da177e4 | 1268 | struct timespec t; |
ef00be05 | 1269 | unsigned int uninitialized_var(serial); |
9ad9ad38 | 1270 | int reserve; |
ac4cec44 | 1271 | unsigned long timeout_start = jiffies; |
1da177e4 | 1272 | |
a3f07114 | 1273 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1274 | return NULL; |
1275 | ||
c8edc80c DK |
1276 | if (unlikely(audit_filter_type(type))) |
1277 | return NULL; | |
1278 | ||
9ad9ad38 DW |
1279 | if (gfp_mask & __GFP_WAIT) |
1280 | reserve = 0; | |
1281 | else | |
5600b892 | 1282 | reserve = 5; /* Allow atomic callers to go up to five |
9ad9ad38 DW |
1283 | entries over the normal backlog limit */ |
1284 | ||
1285 | while (audit_backlog_limit | |
1286 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { | |
82919919 AM |
1287 | if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) { |
1288 | unsigned long sleep_time; | |
9ad9ad38 | 1289 | |
82919919 AM |
1290 | sleep_time = timeout_start + audit_backlog_wait_time - |
1291 | jiffies; | |
8ac1c8d5 | 1292 | if ((long)sleep_time > 0) { |
ae887e0b RGB |
1293 | sleep_time = wait_for_auditd(sleep_time); |
1294 | if ((long)sleep_time > 0) | |
1295 | continue; | |
8ac1c8d5 | 1296 | } |
9ad9ad38 | 1297 | } |
320f1b1e | 1298 | if (audit_rate_check() && printk_ratelimit()) |
fb19b4c6 DW |
1299 | printk(KERN_WARNING |
1300 | "audit: audit_backlog=%d > " | |
1301 | "audit_backlog_limit=%d\n", | |
1302 | skb_queue_len(&audit_skb_queue), | |
1303 | audit_backlog_limit); | |
1304 | audit_log_lost("backlog limit exceeded"); | |
ac4cec44 DW |
1305 | audit_backlog_wait_time = audit_backlog_wait_overflow; |
1306 | wake_up(&audit_backlog_wait); | |
fb19b4c6 DW |
1307 | return NULL; |
1308 | } | |
1309 | ||
e789e561 RGB |
1310 | audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; |
1311 | ||
9ad9ad38 | 1312 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1313 | if (!ab) { |
1314 | audit_log_lost("out of memory in audit_log_start"); | |
1315 | return NULL; | |
1316 | } | |
1317 | ||
bfb4496e | 1318 | audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6 | 1319 | |
1da177e4 LT |
1320 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
1321 | t.tv_sec, t.tv_nsec/1000000, serial); | |
1322 | return ab; | |
1323 | } | |
1324 | ||
8fc6115c | 1325 | /** |
5ac52f33 | 1326 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1327 | * @ab: audit_buffer |
b0dd25a8 | 1328 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1329 | * |
1330 | * Returns 0 (no space) on failed expansion, or available space if | |
1331 | * successful. | |
1332 | */ | |
e3b926b4 | 1333 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1334 | { |
5ac52f33 | 1335 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1336 | int oldtail = skb_tailroom(skb); |
1337 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1338 | int newtail = skb_tailroom(skb); | |
1339 | ||
5ac52f33 CW |
1340 | if (ret < 0) { |
1341 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1342 | return 0; |
5ac52f33 | 1343 | } |
406a1d86 HX |
1344 | |
1345 | skb->truesize += newtail - oldtail; | |
1346 | return newtail; | |
8fc6115c | 1347 | } |
1da177e4 | 1348 | |
b0dd25a8 RD |
1349 | /* |
1350 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1351 | * room in the audit buffer, more room will be allocated and vsnprint |
1352 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1353 | * can't format message larger than 1024 bytes, so we don't either. |
1354 | */ | |
1da177e4 LT |
1355 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1356 | va_list args) | |
1357 | { | |
1358 | int len, avail; | |
5ac52f33 | 1359 | struct sk_buff *skb; |
eecb0a73 | 1360 | va_list args2; |
1da177e4 LT |
1361 | |
1362 | if (!ab) | |
1363 | return; | |
1364 | ||
5ac52f33 CW |
1365 | BUG_ON(!ab->skb); |
1366 | skb = ab->skb; | |
1367 | avail = skb_tailroom(skb); | |
1368 | if (avail == 0) { | |
e3b926b4 | 1369 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1370 | if (!avail) |
1371 | goto out; | |
1da177e4 | 1372 | } |
eecb0a73 | 1373 | va_copy(args2, args); |
27a884dc | 1374 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1375 | if (len >= avail) { |
1376 | /* The printk buffer is 1024 bytes long, so if we get | |
1377 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1378 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1379 | avail = audit_expand(ab, |
1380 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1381 | if (!avail) |
a0e86bd4 | 1382 | goto out_va_end; |
27a884dc | 1383 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1384 | } |
168b7173 SG |
1385 | if (len > 0) |
1386 | skb_put(skb, len); | |
a0e86bd4 JJ |
1387 | out_va_end: |
1388 | va_end(args2); | |
8fc6115c CW |
1389 | out: |
1390 | return; | |
1da177e4 LT |
1391 | } |
1392 | ||
b0dd25a8 RD |
1393 | /** |
1394 | * audit_log_format - format a message into the audit buffer. | |
1395 | * @ab: audit_buffer | |
1396 | * @fmt: format string | |
1397 | * @...: optional parameters matching @fmt string | |
1398 | * | |
1399 | * All the work is done in audit_log_vformat. | |
1400 | */ | |
1da177e4 LT |
1401 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1402 | { | |
1403 | va_list args; | |
1404 | ||
1405 | if (!ab) | |
1406 | return; | |
1407 | va_start(args, fmt); | |
1408 | audit_log_vformat(ab, fmt, args); | |
1409 | va_end(args); | |
1410 | } | |
1411 | ||
b0dd25a8 RD |
1412 | /** |
1413 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
1414 | * @ab: the audit_buffer | |
1415 | * @buf: buffer to convert to hex | |
1416 | * @len: length of @buf to be converted | |
1417 | * | |
1418 | * No return value; failure to expand is silently ignored. | |
1419 | * | |
1420 | * This function will take the passed buf and convert it into a string of | |
1421 | * ascii hex digits. The new string is placed onto the skb. | |
1422 | */ | |
b556f8ad | 1423 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1424 | size_t len) |
83c7d091 | 1425 | { |
168b7173 SG |
1426 | int i, avail, new_len; |
1427 | unsigned char *ptr; | |
1428 | struct sk_buff *skb; | |
1429 | static const unsigned char *hex = "0123456789ABCDEF"; | |
1430 | ||
8ef2d304 AG |
1431 | if (!ab) |
1432 | return; | |
1433 | ||
168b7173 SG |
1434 | BUG_ON(!ab->skb); |
1435 | skb = ab->skb; | |
1436 | avail = skb_tailroom(skb); | |
1437 | new_len = len<<1; | |
1438 | if (new_len >= avail) { | |
1439 | /* Round the buffer request up to the next multiple */ | |
1440 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1441 | avail = audit_expand(ab, new_len); | |
1442 | if (!avail) | |
1443 | return; | |
1444 | } | |
83c7d091 | 1445 | |
27a884dc | 1446 | ptr = skb_tail_pointer(skb); |
168b7173 SG |
1447 | for (i=0; i<len; i++) { |
1448 | *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ | |
1449 | *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ | |
1450 | } | |
1451 | *ptr = 0; | |
1452 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 | 1453 | } |
1454 | ||
9c937dcc AG |
1455 | /* |
1456 | * Format a string of no more than slen characters into the audit buffer, | |
1457 | * enclosed in quote marks. | |
1458 | */ | |
b556f8ad EP |
1459 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1460 | size_t slen) | |
9c937dcc AG |
1461 | { |
1462 | int avail, new_len; | |
1463 | unsigned char *ptr; | |
1464 | struct sk_buff *skb; | |
1465 | ||
8ef2d304 AG |
1466 | if (!ab) |
1467 | return; | |
1468 | ||
9c937dcc AG |
1469 | BUG_ON(!ab->skb); |
1470 | skb = ab->skb; | |
1471 | avail = skb_tailroom(skb); | |
1472 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1473 | if (new_len > avail) { | |
1474 | avail = audit_expand(ab, new_len); | |
1475 | if (!avail) | |
1476 | return; | |
1477 | } | |
27a884dc | 1478 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1479 | *ptr++ = '"'; |
1480 | memcpy(ptr, string, slen); | |
1481 | ptr += slen; | |
1482 | *ptr++ = '"'; | |
1483 | *ptr = 0; | |
1484 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1485 | } | |
1486 | ||
de6bbd1d EP |
1487 | /** |
1488 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1489 | * @string: string to be checked |
1490 | * @len: max length of the string to check | |
de6bbd1d EP |
1491 | */ |
1492 | int audit_string_contains_control(const char *string, size_t len) | |
1493 | { | |
1494 | const unsigned char *p; | |
b3897f56 | 1495 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1496 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
de6bbd1d EP |
1497 | return 1; |
1498 | } | |
1499 | return 0; | |
1500 | } | |
1501 | ||
b0dd25a8 | 1502 | /** |
522ed776 | 1503 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1504 | * @ab: audit_buffer |
f706d5d2 | 1505 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1506 | * @string: string to be logged |
1507 | * | |
1508 | * This code will escape a string that is passed to it if the string | |
1509 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1510 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1511 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1512 | * |
1513 | * The caller specifies the number of characters in the string to log, which may | |
1514 | * or may not be the entire string. | |
b0dd25a8 | 1515 | */ |
b556f8ad EP |
1516 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
1517 | size_t len) | |
83c7d091 | 1518 | { |
de6bbd1d | 1519 | if (audit_string_contains_control(string, len)) |
b556f8ad | 1520 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 1521 | else |
b556f8ad | 1522 | audit_log_n_string(ab, string, len); |
83c7d091 | 1523 | } |
1524 | ||
9c937dcc | 1525 | /** |
522ed776 | 1526 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
1527 | * @ab: audit_buffer |
1528 | * @string: string to be logged | |
1529 | * | |
522ed776 | 1530 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
1531 | * determine string length. |
1532 | */ | |
de6bbd1d | 1533 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 1534 | { |
b556f8ad | 1535 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
1536 | } |
1537 | ||
168b7173 | 1538 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 1539 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 1540 | const struct path *path) |
1da177e4 | 1541 | { |
44707fdf | 1542 | char *p, *pathname; |
1da177e4 | 1543 | |
8fc6115c | 1544 | if (prefix) |
c158a35c | 1545 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 1546 | |
168b7173 | 1547 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
1548 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
1549 | if (!pathname) { | |
def57543 | 1550 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 1551 | return; |
1da177e4 | 1552 | } |
cf28b486 | 1553 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
1554 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
1555 | /* FIXME: can we save some information here? */ | |
def57543 | 1556 | audit_log_string(ab, "<too_long>"); |
5600b892 | 1557 | } else |
168b7173 | 1558 | audit_log_untrustedstring(ab, p); |
44707fdf | 1559 | kfree(pathname); |
1da177e4 LT |
1560 | } |
1561 | ||
4d3fb709 EP |
1562 | void audit_log_session_info(struct audit_buffer *ab) |
1563 | { | |
1564 | u32 sessionid = audit_get_sessionid(current); | |
1565 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); | |
1566 | ||
b8f89caa | 1567 | audit_log_format(ab, " auid=%u ses=%u", auid, sessionid); |
4d3fb709 EP |
1568 | } |
1569 | ||
9d960985 EP |
1570 | void audit_log_key(struct audit_buffer *ab, char *key) |
1571 | { | |
1572 | audit_log_format(ab, " key="); | |
1573 | if (key) | |
1574 | audit_log_untrustedstring(ab, key); | |
1575 | else | |
1576 | audit_log_format(ab, "(null)"); | |
1577 | } | |
1578 | ||
b24a30a7 EP |
1579 | void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) |
1580 | { | |
1581 | int i; | |
1582 | ||
1583 | audit_log_format(ab, " %s=", prefix); | |
1584 | CAP_FOR_EACH_U32(i) { | |
1585 | audit_log_format(ab, "%08x", | |
1586 | cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]); | |
1587 | } | |
1588 | } | |
1589 | ||
1590 | void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) | |
1591 | { | |
1592 | kernel_cap_t *perm = &name->fcap.permitted; | |
1593 | kernel_cap_t *inh = &name->fcap.inheritable; | |
1594 | int log = 0; | |
1595 | ||
1596 | if (!cap_isclear(*perm)) { | |
1597 | audit_log_cap(ab, "cap_fp", perm); | |
1598 | log = 1; | |
1599 | } | |
1600 | if (!cap_isclear(*inh)) { | |
1601 | audit_log_cap(ab, "cap_fi", inh); | |
1602 | log = 1; | |
1603 | } | |
1604 | ||
1605 | if (log) | |
1606 | audit_log_format(ab, " cap_fe=%d cap_fver=%x", | |
1607 | name->fcap.fE, name->fcap_ver); | |
1608 | } | |
1609 | ||
1610 | static inline int audit_copy_fcaps(struct audit_names *name, | |
1611 | const struct dentry *dentry) | |
1612 | { | |
1613 | struct cpu_vfs_cap_data caps; | |
1614 | int rc; | |
1615 | ||
1616 | if (!dentry) | |
1617 | return 0; | |
1618 | ||
1619 | rc = get_vfs_caps_from_disk(dentry, &caps); | |
1620 | if (rc) | |
1621 | return rc; | |
1622 | ||
1623 | name->fcap.permitted = caps.permitted; | |
1624 | name->fcap.inheritable = caps.inheritable; | |
1625 | name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); | |
1626 | name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> | |
1627 | VFS_CAP_REVISION_SHIFT; | |
1628 | ||
1629 | return 0; | |
1630 | } | |
1631 | ||
1632 | /* Copy inode data into an audit_names. */ | |
1633 | void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, | |
1634 | const struct inode *inode) | |
1635 | { | |
1636 | name->ino = inode->i_ino; | |
1637 | name->dev = inode->i_sb->s_dev; | |
1638 | name->mode = inode->i_mode; | |
1639 | name->uid = inode->i_uid; | |
1640 | name->gid = inode->i_gid; | |
1641 | name->rdev = inode->i_rdev; | |
1642 | security_inode_getsecid(inode, &name->osid); | |
1643 | audit_copy_fcaps(name, dentry); | |
1644 | } | |
1645 | ||
1646 | /** | |
1647 | * audit_log_name - produce AUDIT_PATH record from struct audit_names | |
1648 | * @context: audit_context for the task | |
1649 | * @n: audit_names structure with reportable details | |
1650 | * @path: optional path to report instead of audit_names->name | |
1651 | * @record_num: record number to report when handling a list of names | |
1652 | * @call_panic: optional pointer to int that will be updated if secid fails | |
1653 | */ | |
1654 | void audit_log_name(struct audit_context *context, struct audit_names *n, | |
1655 | struct path *path, int record_num, int *call_panic) | |
1656 | { | |
1657 | struct audit_buffer *ab; | |
1658 | ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); | |
1659 | if (!ab) | |
1660 | return; | |
1661 | ||
1662 | audit_log_format(ab, "item=%d", record_num); | |
1663 | ||
1664 | if (path) | |
1665 | audit_log_d_path(ab, " name=", path); | |
1666 | else if (n->name) { | |
1667 | switch (n->name_len) { | |
1668 | case AUDIT_NAME_FULL: | |
1669 | /* log the full path */ | |
1670 | audit_log_format(ab, " name="); | |
1671 | audit_log_untrustedstring(ab, n->name->name); | |
1672 | break; | |
1673 | case 0: | |
1674 | /* name was specified as a relative path and the | |
1675 | * directory component is the cwd */ | |
1676 | audit_log_d_path(ab, " name=", &context->pwd); | |
1677 | break; | |
1678 | default: | |
1679 | /* log the name's directory component */ | |
1680 | audit_log_format(ab, " name="); | |
1681 | audit_log_n_untrustedstring(ab, n->name->name, | |
1682 | n->name_len); | |
1683 | } | |
1684 | } else | |
1685 | audit_log_format(ab, " name=(null)"); | |
1686 | ||
1687 | if (n->ino != (unsigned long)-1) { | |
1688 | audit_log_format(ab, " inode=%lu" | |
1689 | " dev=%02x:%02x mode=%#ho" | |
1690 | " ouid=%u ogid=%u rdev=%02x:%02x", | |
1691 | n->ino, | |
1692 | MAJOR(n->dev), | |
1693 | MINOR(n->dev), | |
1694 | n->mode, | |
1695 | from_kuid(&init_user_ns, n->uid), | |
1696 | from_kgid(&init_user_ns, n->gid), | |
1697 | MAJOR(n->rdev), | |
1698 | MINOR(n->rdev)); | |
1699 | } | |
1700 | if (n->osid != 0) { | |
1701 | char *ctx = NULL; | |
1702 | u32 len; | |
1703 | if (security_secid_to_secctx( | |
1704 | n->osid, &ctx, &len)) { | |
1705 | audit_log_format(ab, " osid=%u", n->osid); | |
1706 | if (call_panic) | |
1707 | *call_panic = 2; | |
1708 | } else { | |
1709 | audit_log_format(ab, " obj=%s", ctx); | |
1710 | security_release_secctx(ctx, len); | |
1711 | } | |
1712 | } | |
1713 | ||
d3aea84a JL |
1714 | /* log the audit_names record type */ |
1715 | audit_log_format(ab, " nametype="); | |
1716 | switch(n->type) { | |
1717 | case AUDIT_TYPE_NORMAL: | |
1718 | audit_log_format(ab, "NORMAL"); | |
1719 | break; | |
1720 | case AUDIT_TYPE_PARENT: | |
1721 | audit_log_format(ab, "PARENT"); | |
1722 | break; | |
1723 | case AUDIT_TYPE_CHILD_DELETE: | |
1724 | audit_log_format(ab, "DELETE"); | |
1725 | break; | |
1726 | case AUDIT_TYPE_CHILD_CREATE: | |
1727 | audit_log_format(ab, "CREATE"); | |
1728 | break; | |
1729 | default: | |
1730 | audit_log_format(ab, "UNKNOWN"); | |
1731 | break; | |
1732 | } | |
1733 | ||
b24a30a7 EP |
1734 | audit_log_fcaps(ab, n); |
1735 | audit_log_end(ab); | |
1736 | } | |
1737 | ||
1738 | int audit_log_task_context(struct audit_buffer *ab) | |
1739 | { | |
1740 | char *ctx = NULL; | |
1741 | unsigned len; | |
1742 | int error; | |
1743 | u32 sid; | |
1744 | ||
1745 | security_task_getsecid(current, &sid); | |
1746 | if (!sid) | |
1747 | return 0; | |
1748 | ||
1749 | error = security_secid_to_secctx(sid, &ctx, &len); | |
1750 | if (error) { | |
1751 | if (error != -EINVAL) | |
1752 | goto error_path; | |
1753 | return 0; | |
1754 | } | |
1755 | ||
1756 | audit_log_format(ab, " subj=%s", ctx); | |
1757 | security_release_secctx(ctx, len); | |
1758 | return 0; | |
1759 | ||
1760 | error_path: | |
1761 | audit_panic("error in audit_log_task_context"); | |
1762 | return error; | |
1763 | } | |
1764 | EXPORT_SYMBOL(audit_log_task_context); | |
1765 | ||
1766 | void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) | |
1767 | { | |
1768 | const struct cred *cred; | |
1769 | char name[sizeof(tsk->comm)]; | |
1770 | struct mm_struct *mm = tsk->mm; | |
1771 | char *tty; | |
1772 | ||
1773 | if (!ab) | |
1774 | return; | |
1775 | ||
1776 | /* tsk == current */ | |
1777 | cred = current_cred(); | |
1778 | ||
1779 | spin_lock_irq(&tsk->sighand->siglock); | |
1780 | if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) | |
1781 | tty = tsk->signal->tty->name; | |
1782 | else | |
1783 | tty = "(none)"; | |
1784 | spin_unlock_irq(&tsk->sighand->siglock); | |
1785 | ||
1786 | audit_log_format(ab, | |
1787 | " ppid=%ld pid=%d auid=%u uid=%u gid=%u" | |
1788 | " euid=%u suid=%u fsuid=%u" | |
2f2ad101 | 1789 | " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", |
b24a30a7 EP |
1790 | sys_getppid(), |
1791 | tsk->pid, | |
1792 | from_kuid(&init_user_ns, audit_get_loginuid(tsk)), | |
1793 | from_kuid(&init_user_ns, cred->uid), | |
1794 | from_kgid(&init_user_ns, cred->gid), | |
1795 | from_kuid(&init_user_ns, cred->euid), | |
1796 | from_kuid(&init_user_ns, cred->suid), | |
1797 | from_kuid(&init_user_ns, cred->fsuid), | |
1798 | from_kgid(&init_user_ns, cred->egid), | |
1799 | from_kgid(&init_user_ns, cred->sgid), | |
1800 | from_kgid(&init_user_ns, cred->fsgid), | |
2f2ad101 | 1801 | tty, audit_get_sessionid(tsk)); |
b24a30a7 EP |
1802 | |
1803 | get_task_comm(name, tsk); | |
1804 | audit_log_format(ab, " comm="); | |
1805 | audit_log_untrustedstring(ab, name); | |
1806 | ||
1807 | if (mm) { | |
1808 | down_read(&mm->mmap_sem); | |
1809 | if (mm->exe_file) | |
1810 | audit_log_d_path(ab, " exe=", &mm->exe_file->f_path); | |
1811 | up_read(&mm->mmap_sem); | |
1812 | } | |
1813 | audit_log_task_context(ab); | |
1814 | } | |
1815 | EXPORT_SYMBOL(audit_log_task_info); | |
1816 | ||
a51d9eaa KC |
1817 | /** |
1818 | * audit_log_link_denied - report a link restriction denial | |
1819 | * @operation: specific link opreation | |
1820 | * @link: the path that triggered the restriction | |
1821 | */ | |
1822 | void audit_log_link_denied(const char *operation, struct path *link) | |
1823 | { | |
1824 | struct audit_buffer *ab; | |
b24a30a7 EP |
1825 | struct audit_names *name; |
1826 | ||
1827 | name = kzalloc(sizeof(*name), GFP_NOFS); | |
1828 | if (!name) | |
1829 | return; | |
a51d9eaa | 1830 | |
b24a30a7 | 1831 | /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ |
a51d9eaa KC |
1832 | ab = audit_log_start(current->audit_context, GFP_KERNEL, |
1833 | AUDIT_ANOM_LINK); | |
d1c7d97a | 1834 | if (!ab) |
b24a30a7 EP |
1835 | goto out; |
1836 | audit_log_format(ab, "op=%s", operation); | |
1837 | audit_log_task_info(ab, current); | |
1838 | audit_log_format(ab, " res=0"); | |
a51d9eaa | 1839 | audit_log_end(ab); |
b24a30a7 EP |
1840 | |
1841 | /* Generate AUDIT_PATH record with object. */ | |
1842 | name->type = AUDIT_TYPE_NORMAL; | |
1843 | audit_copy_inode(name, link->dentry, link->dentry->d_inode); | |
1844 | audit_log_name(current->audit_context, name, link, 0, NULL); | |
1845 | out: | |
1846 | kfree(name); | |
a51d9eaa KC |
1847 | } |
1848 | ||
b0dd25a8 RD |
1849 | /** |
1850 | * audit_log_end - end one audit record | |
1851 | * @ab: the audit_buffer | |
1852 | * | |
1853 | * The netlink_* functions cannot be called inside an irq context, so | |
1854 | * the audit buffer is placed on a queue and a tasklet is scheduled to | |
1da177e4 | 1855 | * remove them from the queue outside the irq context. May be called in |
b0dd25a8 RD |
1856 | * any context. |
1857 | */ | |
b7d11258 | 1858 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 1859 | { |
1da177e4 LT |
1860 | if (!ab) |
1861 | return; | |
1862 | if (!audit_rate_check()) { | |
1863 | audit_log_lost("rate limit exceeded"); | |
1864 | } else { | |
8d07a67c | 1865 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
94191213 | 1866 | nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN; |
f3d357b0 | 1867 | |
b7d11258 | 1868 | if (audit_pid) { |
b7d11258 | 1869 | skb_queue_tail(&audit_skb_queue, ab->skb); |
b7d11258 | 1870 | wake_up_interruptible(&kauditd_wait); |
f3d357b0 | 1871 | } else { |
038cbcf6 | 1872 | audit_printk_skb(ab->skb); |
b7d11258 | 1873 | } |
f3d357b0 | 1874 | ab->skb = NULL; |
1da177e4 | 1875 | } |
16e1904e | 1876 | audit_buffer_free(ab); |
1da177e4 LT |
1877 | } |
1878 | ||
b0dd25a8 RD |
1879 | /** |
1880 | * audit_log - Log an audit record | |
1881 | * @ctx: audit context | |
1882 | * @gfp_mask: type of allocation | |
1883 | * @type: audit message type | |
1884 | * @fmt: format string to use | |
1885 | * @...: variable parameters matching the format string | |
1886 | * | |
1887 | * This is a convenience function that calls audit_log_start, | |
1888 | * audit_log_vformat, and audit_log_end. It may be called | |
1889 | * in any context. | |
1890 | */ | |
5600b892 | 1891 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 1892 | const char *fmt, ...) |
1da177e4 LT |
1893 | { |
1894 | struct audit_buffer *ab; | |
1895 | va_list args; | |
1896 | ||
9ad9ad38 | 1897 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
1898 | if (ab) { |
1899 | va_start(args, fmt); | |
1900 | audit_log_vformat(ab, fmt, args); | |
1901 | va_end(args); | |
1902 | audit_log_end(ab); | |
1903 | } | |
1904 | } | |
bf45da97 | 1905 | |
131ad62d MDF |
1906 | #ifdef CONFIG_SECURITY |
1907 | /** | |
1908 | * audit_log_secctx - Converts and logs SELinux context | |
1909 | * @ab: audit_buffer | |
1910 | * @secid: security number | |
1911 | * | |
1912 | * This is a helper function that calls security_secid_to_secctx to convert | |
1913 | * secid to secctx and then adds the (converted) SELinux context to the audit | |
1914 | * log by calling audit_log_format, thus also preventing leak of internal secid | |
1915 | * to userspace. If secid cannot be converted audit_panic is called. | |
1916 | */ | |
1917 | void audit_log_secctx(struct audit_buffer *ab, u32 secid) | |
1918 | { | |
1919 | u32 len; | |
1920 | char *secctx; | |
1921 | ||
1922 | if (security_secid_to_secctx(secid, &secctx, &len)) { | |
1923 | audit_panic("Cannot convert secid to context"); | |
1924 | } else { | |
1925 | audit_log_format(ab, " obj=%s", secctx); | |
1926 | security_release_secctx(secctx, len); | |
1927 | } | |
1928 | } | |
1929 | EXPORT_SYMBOL(audit_log_secctx); | |
1930 | #endif | |
1931 | ||
bf45da97 | 1932 | EXPORT_SYMBOL(audit_log_start); |
1933 | EXPORT_SYMBOL(audit_log_end); | |
1934 | EXPORT_SYMBOL(audit_log_format); | |
1935 | EXPORT_SYMBOL(audit_log); |