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 | ||
40c0775e RGB |
104 | /* Number of outstanding audit_buffers allowed. |
105 | * When set to zero, this means unlimited. */ | |
1da177e4 | 106 | static int audit_backlog_limit = 64; |
e789e561 RGB |
107 | #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ) |
108 | static int audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; | |
ac4cec44 | 109 | static int audit_backlog_wait_overflow = 0; |
1da177e4 | 110 | |
c2f0c7c3 | 111 | /* The identity of the user shutting down the audit system. */ |
cca080d9 | 112 | kuid_t audit_sig_uid = INVALID_UID; |
c2f0c7c3 | 113 | pid_t audit_sig_pid = -1; |
e1396065 | 114 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 115 | |
1da177e4 LT |
116 | /* Records can be lost in several ways: |
117 | 0) [suppressed in audit_alloc] | |
118 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
119 | 2) out of memory in audit_log_move [alloc_skb] | |
120 | 3) suppressed due to audit_rate_limit | |
121 | 4) suppressed due to audit_backlog_limit | |
122 | */ | |
123 | static atomic_t audit_lost = ATOMIC_INIT(0); | |
124 | ||
125 | /* The netlink socket. */ | |
126 | static struct sock *audit_sock; | |
33faba7f | 127 | int audit_net_id; |
1da177e4 | 128 | |
f368c07d AG |
129 | /* Hash for inode-based rules */ |
130 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
131 | ||
b7d11258 | 132 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
1da177e4 LT |
133 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
134 | * being placed on the freelist). */ | |
1da177e4 | 135 | static DEFINE_SPINLOCK(audit_freelist_lock); |
b0dd25a8 | 136 | static int audit_freelist_count; |
1da177e4 LT |
137 | static LIST_HEAD(audit_freelist); |
138 | ||
b7d11258 | 139 | static struct sk_buff_head audit_skb_queue; |
f3d357b0 EP |
140 | /* queue of skbs to send to auditd when/if it comes back */ |
141 | static struct sk_buff_head audit_skb_hold_queue; | |
b7d11258 DW |
142 | static struct task_struct *kauditd_task; |
143 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
9ad9ad38 | 144 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 145 | |
b0fed402 EP |
146 | static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION, |
147 | .mask = -1, | |
148 | .features = 0, | |
149 | .lock = 0,}; | |
150 | ||
21b85c31 | 151 | static char *audit_feature_names[2] = { |
d040e5af | 152 | "only_unset_loginuid", |
21b85c31 | 153 | "loginuid_immutable", |
b0fed402 EP |
154 | }; |
155 | ||
156 | ||
f368c07d | 157 | /* Serialize requests from userspace. */ |
916d7576 | 158 | DEFINE_MUTEX(audit_cmd_mutex); |
1da177e4 LT |
159 | |
160 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
161 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
162 | * should be at least that large. */ | |
163 | #define AUDIT_BUFSIZ 1024 | |
164 | ||
165 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the | |
166 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ | |
167 | #define AUDIT_MAXFREE (2*NR_CPUS) | |
168 | ||
169 | /* The audit_buffer is used when formatting an audit record. The caller | |
170 | * locks briefly to get the record off the freelist or to allocate the | |
171 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
172 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
173 | * use simultaneously. */ | |
174 | struct audit_buffer { | |
175 | struct list_head list; | |
8fc6115c | 176 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 177 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 178 | gfp_t gfp_mask; |
1da177e4 LT |
179 | }; |
180 | ||
f09ac9db | 181 | struct audit_reply { |
f9441639 | 182 | __u32 portid; |
33faba7f | 183 | pid_t pid; |
f09ac9db EP |
184 | struct sk_buff *skb; |
185 | }; | |
186 | ||
f9441639 | 187 | static void audit_set_portid(struct audit_buffer *ab, __u32 portid) |
c0404993 | 188 | { |
50397bd1 EP |
189 | if (ab) { |
190 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); | |
f9441639 | 191 | nlh->nlmsg_pid = portid; |
50397bd1 | 192 | } |
c0404993 SG |
193 | } |
194 | ||
8c8570fb | 195 | void audit_panic(const char *message) |
1da177e4 LT |
196 | { |
197 | switch (audit_failure) | |
198 | { | |
199 | case AUDIT_FAIL_SILENT: | |
200 | break; | |
201 | case AUDIT_FAIL_PRINTK: | |
320f1b1e EP |
202 | if (printk_ratelimit()) |
203 | printk(KERN_ERR "audit: %s\n", message); | |
1da177e4 LT |
204 | break; |
205 | case AUDIT_FAIL_PANIC: | |
b29ee87e EP |
206 | /* test audit_pid since printk is always losey, why bother? */ |
207 | if (audit_pid) | |
208 | panic("audit: %s\n", message); | |
1da177e4 LT |
209 | break; |
210 | } | |
211 | } | |
212 | ||
213 | static inline int audit_rate_check(void) | |
214 | { | |
215 | static unsigned long last_check = 0; | |
216 | static int messages = 0; | |
217 | static DEFINE_SPINLOCK(lock); | |
218 | unsigned long flags; | |
219 | unsigned long now; | |
220 | unsigned long elapsed; | |
221 | int retval = 0; | |
222 | ||
223 | if (!audit_rate_limit) return 1; | |
224 | ||
225 | spin_lock_irqsave(&lock, flags); | |
226 | if (++messages < audit_rate_limit) { | |
227 | retval = 1; | |
228 | } else { | |
229 | now = jiffies; | |
230 | elapsed = now - last_check; | |
231 | if (elapsed > HZ) { | |
232 | last_check = now; | |
233 | messages = 0; | |
234 | retval = 1; | |
235 | } | |
236 | } | |
237 | spin_unlock_irqrestore(&lock, flags); | |
238 | ||
239 | return retval; | |
240 | } | |
241 | ||
b0dd25a8 RD |
242 | /** |
243 | * audit_log_lost - conditionally log lost audit message event | |
244 | * @message: the message stating reason for lost audit message | |
245 | * | |
246 | * Emit at least 1 message per second, even if audit_rate_check is | |
247 | * throttling. | |
248 | * Always increment the lost messages counter. | |
249 | */ | |
1da177e4 LT |
250 | void audit_log_lost(const char *message) |
251 | { | |
252 | static unsigned long last_msg = 0; | |
253 | static DEFINE_SPINLOCK(lock); | |
254 | unsigned long flags; | |
255 | unsigned long now; | |
256 | int print; | |
257 | ||
258 | atomic_inc(&audit_lost); | |
259 | ||
260 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
261 | ||
262 | if (!print) { | |
263 | spin_lock_irqsave(&lock, flags); | |
264 | now = jiffies; | |
265 | if (now - last_msg > HZ) { | |
266 | print = 1; | |
267 | last_msg = now; | |
268 | } | |
269 | spin_unlock_irqrestore(&lock, flags); | |
270 | } | |
271 | ||
272 | if (print) { | |
320f1b1e EP |
273 | if (printk_ratelimit()) |
274 | printk(KERN_WARNING | |
275 | "audit: audit_lost=%d audit_rate_limit=%d " | |
276 | "audit_backlog_limit=%d\n", | |
277 | atomic_read(&audit_lost), | |
278 | audit_rate_limit, | |
279 | audit_backlog_limit); | |
1da177e4 LT |
280 | audit_panic(message); |
281 | } | |
1da177e4 LT |
282 | } |
283 | ||
1a6b9f23 | 284 | static int audit_log_config_change(char *function_name, int new, int old, |
2532386f | 285 | int allow_changes) |
1da177e4 | 286 | { |
1a6b9f23 EP |
287 | struct audit_buffer *ab; |
288 | int rc = 0; | |
ce29b682 | 289 | |
1a6b9f23 | 290 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
0644ec0c KC |
291 | if (unlikely(!ab)) |
292 | return rc; | |
4d3fb709 EP |
293 | audit_log_format(ab, "%s=%d old=%d", function_name, new, old); |
294 | audit_log_session_info(ab); | |
b122c376 EP |
295 | rc = audit_log_task_context(ab); |
296 | if (rc) | |
297 | allow_changes = 0; /* Something weird, deny request */ | |
1a6b9f23 EP |
298 | audit_log_format(ab, " res=%d", allow_changes); |
299 | audit_log_end(ab); | |
6a01b07f | 300 | return rc; |
1da177e4 LT |
301 | } |
302 | ||
dc9eb698 | 303 | static int audit_do_config_change(char *function_name, int *to_change, int new) |
1da177e4 | 304 | { |
1a6b9f23 | 305 | int allow_changes, rc = 0, old = *to_change; |
6a01b07f SG |
306 | |
307 | /* check if we are locked */ | |
1a6b9f23 EP |
308 | if (audit_enabled == AUDIT_LOCKED) |
309 | allow_changes = 0; | |
6a01b07f | 310 | else |
1a6b9f23 | 311 | allow_changes = 1; |
ce29b682 | 312 | |
1a6b9f23 | 313 | if (audit_enabled != AUDIT_OFF) { |
dc9eb698 | 314 | rc = audit_log_config_change(function_name, new, old, allow_changes); |
1a6b9f23 EP |
315 | if (rc) |
316 | allow_changes = 0; | |
6a01b07f | 317 | } |
6a01b07f SG |
318 | |
319 | /* If we are allowed, make the change */ | |
1a6b9f23 EP |
320 | if (allow_changes == 1) |
321 | *to_change = new; | |
6a01b07f SG |
322 | /* Not allowed, update reason */ |
323 | else if (rc == 0) | |
324 | rc = -EPERM; | |
325 | return rc; | |
1da177e4 LT |
326 | } |
327 | ||
dc9eb698 | 328 | static int audit_set_rate_limit(int limit) |
1da177e4 | 329 | { |
dc9eb698 | 330 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); |
1a6b9f23 | 331 | } |
ce29b682 | 332 | |
dc9eb698 | 333 | static int audit_set_backlog_limit(int limit) |
1a6b9f23 | 334 | { |
dc9eb698 | 335 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); |
1a6b9f23 | 336 | } |
6a01b07f | 337 | |
51cc83f0 RGB |
338 | static int audit_set_backlog_wait_time(int timeout) |
339 | { | |
340 | return audit_do_config_change("audit_backlog_wait_time", | |
341 | &audit_backlog_wait_time, timeout); | |
342 | } | |
343 | ||
dc9eb698 | 344 | static int audit_set_enabled(int state) |
1a6b9f23 | 345 | { |
b593d384 | 346 | int rc; |
1a6b9f23 EP |
347 | if (state < AUDIT_OFF || state > AUDIT_LOCKED) |
348 | return -EINVAL; | |
6a01b07f | 349 | |
dc9eb698 | 350 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
b593d384 EP |
351 | if (!rc) |
352 | audit_ever_enabled |= !!state; | |
353 | ||
354 | return rc; | |
1da177e4 LT |
355 | } |
356 | ||
dc9eb698 | 357 | static int audit_set_failure(int state) |
1da177e4 | 358 | { |
1da177e4 LT |
359 | if (state != AUDIT_FAIL_SILENT |
360 | && state != AUDIT_FAIL_PRINTK | |
361 | && state != AUDIT_FAIL_PANIC) | |
362 | return -EINVAL; | |
ce29b682 | 363 | |
dc9eb698 | 364 | return audit_do_config_change("audit_failure", &audit_failure, state); |
1da177e4 LT |
365 | } |
366 | ||
f3d357b0 EP |
367 | /* |
368 | * Queue skbs to be sent to auditd when/if it comes back. These skbs should | |
369 | * already have been sent via prink/syslog and so if these messages are dropped | |
370 | * it is not a huge concern since we already passed the audit_log_lost() | |
371 | * notification and stuff. This is just nice to get audit messages during | |
372 | * boot before auditd is running or messages generated while auditd is stopped. | |
373 | * This only holds messages is audit_default is set, aka booting with audit=1 | |
374 | * or building your kernel that way. | |
375 | */ | |
376 | static void audit_hold_skb(struct sk_buff *skb) | |
377 | { | |
378 | if (audit_default && | |
40c0775e RGB |
379 | (!audit_backlog_limit || |
380 | skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)) | |
f3d357b0 EP |
381 | skb_queue_tail(&audit_skb_hold_queue, skb); |
382 | else | |
383 | kfree_skb(skb); | |
384 | } | |
385 | ||
038cbcf6 EP |
386 | /* |
387 | * For one reason or another this nlh isn't getting delivered to the userspace | |
388 | * audit daemon, just send it to printk. | |
389 | */ | |
390 | static void audit_printk_skb(struct sk_buff *skb) | |
391 | { | |
392 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 393 | char *data = nlmsg_data(nlh); |
038cbcf6 EP |
394 | |
395 | if (nlh->nlmsg_type != AUDIT_EOE) { | |
396 | if (printk_ratelimit()) | |
397 | printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data); | |
398 | else | |
399 | audit_log_lost("printk limit exceeded\n"); | |
400 | } | |
401 | ||
402 | audit_hold_skb(skb); | |
403 | } | |
404 | ||
f3d357b0 EP |
405 | static void kauditd_send_skb(struct sk_buff *skb) |
406 | { | |
407 | int err; | |
408 | /* take a reference in case we can't send it and we want to hold it */ | |
409 | skb_get(skb); | |
15e47304 | 410 | err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0); |
f3d357b0 | 411 | if (err < 0) { |
c9404c9c | 412 | BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */ |
f3d357b0 | 413 | printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); |
9db3b9bc | 414 | audit_log_lost("auditd disappeared\n"); |
f3d357b0 | 415 | audit_pid = 0; |
33faba7f | 416 | audit_sock = NULL; |
f3d357b0 EP |
417 | /* we might get lucky and get this in the next auditd */ |
418 | audit_hold_skb(skb); | |
419 | } else | |
420 | /* drop the extra reference if sent ok */ | |
70d4bf6d | 421 | consume_skb(skb); |
f3d357b0 EP |
422 | } |
423 | ||
b551d1d9 RGB |
424 | /* |
425 | * flush_hold_queue - empty the hold queue if auditd appears | |
426 | * | |
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 | static void flush_hold_queue(void) | |
b7d11258 DW |
440 | { |
441 | struct sk_buff *skb; | |
442 | ||
b551d1d9 RGB |
443 | if (!audit_default || !audit_pid) |
444 | return; | |
445 | ||
446 | skb = skb_dequeue(&audit_skb_hold_queue); | |
447 | if (likely(!skb)) | |
448 | return; | |
449 | ||
450 | while (skb && audit_pid) { | |
451 | kauditd_send_skb(skb); | |
452 | skb = skb_dequeue(&audit_skb_hold_queue); | |
453 | } | |
454 | ||
455 | /* | |
456 | * if auditd just disappeared but we | |
457 | * dequeued an skb we need to drop ref | |
458 | */ | |
459 | if (skb) | |
460 | consume_skb(skb); | |
461 | } | |
462 | ||
97a41e26 | 463 | static int kauditd_thread(void *dummy) |
b7d11258 | 464 | { |
83144186 | 465 | set_freezable(); |
4899b8b1 | 466 | while (!kthread_should_stop()) { |
3320c513 RGB |
467 | struct sk_buff *skb; |
468 | DECLARE_WAITQUEUE(wait, current); | |
469 | ||
b551d1d9 | 470 | flush_hold_queue(); |
f3d357b0 | 471 | |
b7d11258 | 472 | skb = skb_dequeue(&audit_skb_queue); |
db897319 | 473 | |
b7d11258 | 474 | if (skb) { |
db897319 DD |
475 | if (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit) |
476 | wake_up(&audit_backlog_wait); | |
f3d357b0 EP |
477 | if (audit_pid) |
478 | kauditd_send_skb(skb); | |
038cbcf6 EP |
479 | else |
480 | audit_printk_skb(skb); | |
3320c513 RGB |
481 | continue; |
482 | } | |
483 | set_current_state(TASK_INTERRUPTIBLE); | |
484 | add_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 485 | |
3320c513 RGB |
486 | if (!skb_queue_len(&audit_skb_queue)) { |
487 | try_to_freeze(); | |
488 | schedule(); | |
b7d11258 | 489 | } |
3320c513 RGB |
490 | |
491 | __set_current_state(TASK_RUNNING); | |
492 | remove_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 493 | } |
4899b8b1 | 494 | return 0; |
b7d11258 DW |
495 | } |
496 | ||
9044e6bc AV |
497 | int audit_send_list(void *_dest) |
498 | { | |
499 | struct audit_netlink_list *dest = _dest; | |
9044e6bc | 500 | struct sk_buff *skb; |
33faba7f RGB |
501 | struct net *net = get_net_ns_by_pid(dest->pid); |
502 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
9044e6bc AV |
503 | |
504 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
505 | mutex_lock(&audit_cmd_mutex); |
506 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
507 | |
508 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
33faba7f | 509 | netlink_unicast(aunet->nlsk, skb, dest->portid, 0); |
9044e6bc AV |
510 | |
511 | kfree(dest); | |
512 | ||
513 | return 0; | |
514 | } | |
515 | ||
f9441639 | 516 | struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done, |
b8800aa5 | 517 | int multi, const void *payload, int size) |
9044e6bc AV |
518 | { |
519 | struct sk_buff *skb; | |
520 | struct nlmsghdr *nlh; | |
9044e6bc AV |
521 | void *data; |
522 | int flags = multi ? NLM_F_MULTI : 0; | |
523 | int t = done ? NLMSG_DONE : type; | |
524 | ||
ee080e6c | 525 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
526 | if (!skb) |
527 | return NULL; | |
528 | ||
f9441639 | 529 | nlh = nlmsg_put(skb, portid, seq, t, size, flags); |
c64e66c6 DM |
530 | if (!nlh) |
531 | goto out_kfree_skb; | |
532 | data = nlmsg_data(nlh); | |
9044e6bc AV |
533 | memcpy(data, payload, size); |
534 | return skb; | |
535 | ||
c64e66c6 DM |
536 | out_kfree_skb: |
537 | kfree_skb(skb); | |
9044e6bc AV |
538 | return NULL; |
539 | } | |
540 | ||
f09ac9db EP |
541 | static int audit_send_reply_thread(void *arg) |
542 | { | |
543 | struct audit_reply *reply = (struct audit_reply *)arg; | |
33faba7f RGB |
544 | struct net *net = get_net_ns_by_pid(reply->pid); |
545 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
f09ac9db EP |
546 | |
547 | mutex_lock(&audit_cmd_mutex); | |
548 | mutex_unlock(&audit_cmd_mutex); | |
549 | ||
550 | /* Ignore failure. It'll only happen if the sender goes away, | |
551 | because our timeout is set to infinite. */ | |
33faba7f | 552 | netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0); |
f09ac9db EP |
553 | kfree(reply); |
554 | return 0; | |
555 | } | |
b0dd25a8 RD |
556 | /** |
557 | * audit_send_reply - send an audit reply message via netlink | |
f9441639 | 558 | * @portid: netlink port to which to send reply |
b0dd25a8 RD |
559 | * @seq: sequence number |
560 | * @type: audit message type | |
561 | * @done: done (last) flag | |
562 | * @multi: multi-part message flag | |
563 | * @payload: payload data | |
564 | * @size: payload size | |
565 | * | |
f9441639 | 566 | * Allocates an skb, builds the netlink message, and sends it to the port id. |
b0dd25a8 RD |
567 | * No failure notifications. |
568 | */ | |
f9441639 RGB |
569 | static void audit_send_reply(__u32 portid, int seq, int type, int done, |
570 | int multi, const void *payload, int size) | |
1da177e4 | 571 | { |
f09ac9db EP |
572 | struct sk_buff *skb; |
573 | struct task_struct *tsk; | |
574 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), | |
575 | GFP_KERNEL); | |
576 | ||
577 | if (!reply) | |
578 | return; | |
579 | ||
f9441639 | 580 | skb = audit_make_reply(portid, seq, type, done, multi, payload, size); |
1da177e4 | 581 | if (!skb) |
fcaf1eb8 | 582 | goto out; |
f09ac9db | 583 | |
f9441639 | 584 | reply->portid = portid; |
33faba7f | 585 | reply->pid = task_pid_vnr(current); |
f09ac9db EP |
586 | reply->skb = skb; |
587 | ||
588 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
fcaf1eb8 AM |
589 | if (!IS_ERR(tsk)) |
590 | return; | |
591 | kfree_skb(skb); | |
592 | out: | |
593 | kfree(reply); | |
1da177e4 LT |
594 | } |
595 | ||
596 | /* | |
597 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
598 | * control messages. | |
599 | */ | |
c7bdb545 | 600 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
601 | { |
602 | int err = 0; | |
603 | ||
34e36d8e EB |
604 | /* Only support the initial namespaces for now. */ |
605 | if ((current_user_ns() != &init_user_ns) || | |
606 | (task_active_pid_ns(current) != &init_pid_ns)) | |
607 | return -EPERM; | |
608 | ||
1da177e4 | 609 | switch (msg_type) { |
1da177e4 | 610 | case AUDIT_LIST: |
1da177e4 LT |
611 | case AUDIT_ADD: |
612 | case AUDIT_DEL: | |
18900909 EP |
613 | return -EOPNOTSUPP; |
614 | case AUDIT_GET: | |
615 | case AUDIT_SET: | |
b0fed402 EP |
616 | case AUDIT_GET_FEATURE: |
617 | case AUDIT_SET_FEATURE: | |
18900909 EP |
618 | case AUDIT_LIST_RULES: |
619 | case AUDIT_ADD_RULE: | |
93315ed6 | 620 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 621 | case AUDIT_SIGNAL_INFO: |
522ed776 MT |
622 | case AUDIT_TTY_GET: |
623 | case AUDIT_TTY_SET: | |
74c3cbe3 AV |
624 | case AUDIT_TRIM: |
625 | case AUDIT_MAKE_EQUIV: | |
fd778461 | 626 | if (!capable(CAP_AUDIT_CONTROL)) |
1da177e4 LT |
627 | err = -EPERM; |
628 | break; | |
05474106 | 629 | case AUDIT_USER: |
039b6b3e RD |
630 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
631 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
fd778461 | 632 | if (!capable(CAP_AUDIT_WRITE)) |
1da177e4 LT |
633 | err = -EPERM; |
634 | break; | |
635 | default: /* bad msg */ | |
636 | err = -EINVAL; | |
637 | } | |
638 | ||
639 | return err; | |
640 | } | |
641 | ||
dc9eb698 | 642 | static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) |
50397bd1 EP |
643 | { |
644 | int rc = 0; | |
dc9eb698 | 645 | uid_t uid = from_kuid(&init_user_ns, current_uid()); |
50397bd1 | 646 | |
0868a5e1 | 647 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) { |
50397bd1 EP |
648 | *ab = NULL; |
649 | return rc; | |
650 | } | |
651 | ||
652 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); | |
0644ec0c KC |
653 | if (unlikely(!*ab)) |
654 | return rc; | |
4d3fb709 EP |
655 | audit_log_format(*ab, "pid=%d uid=%u", task_tgid_vnr(current), uid); |
656 | audit_log_session_info(*ab); | |
b122c376 | 657 | audit_log_task_context(*ab); |
50397bd1 EP |
658 | |
659 | return rc; | |
660 | } | |
661 | ||
b0fed402 EP |
662 | int is_audit_feature_set(int i) |
663 | { | |
664 | return af.features & AUDIT_FEATURE_TO_MASK(i); | |
665 | } | |
666 | ||
667 | ||
668 | static int audit_get_feature(struct sk_buff *skb) | |
669 | { | |
670 | u32 seq; | |
671 | ||
672 | seq = nlmsg_hdr(skb)->nlmsg_seq; | |
673 | ||
674 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, | |
675 | &af, sizeof(af)); | |
676 | ||
677 | return 0; | |
678 | } | |
679 | ||
680 | static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature, | |
681 | u32 old_lock, u32 new_lock, int res) | |
682 | { | |
683 | struct audit_buffer *ab; | |
684 | ||
b6c50fe0 G |
685 | if (audit_enabled == AUDIT_OFF) |
686 | return; | |
687 | ||
b0fed402 | 688 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE); |
aabce351 | 689 | audit_log_format(ab, "feature=%s old=%d new=%d old_lock=%d new_lock=%d res=%d", |
b0fed402 EP |
690 | audit_feature_names[which], !!old_feature, !!new_feature, |
691 | !!old_lock, !!new_lock, res); | |
692 | audit_log_end(ab); | |
693 | } | |
694 | ||
695 | static int audit_set_feature(struct sk_buff *skb) | |
696 | { | |
697 | struct audit_features *uaf; | |
698 | int i; | |
699 | ||
700 | BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > sizeof(audit_feature_names)/sizeof(audit_feature_names[0])); | |
701 | uaf = nlmsg_data(nlmsg_hdr(skb)); | |
702 | ||
703 | /* if there is ever a version 2 we should handle that here */ | |
704 | ||
705 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
706 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
707 | u32 old_feature, new_feature, old_lock, new_lock; | |
708 | ||
709 | /* if we are not changing this feature, move along */ | |
710 | if (!(feature & uaf->mask)) | |
711 | continue; | |
712 | ||
713 | old_feature = af.features & feature; | |
714 | new_feature = uaf->features & feature; | |
715 | new_lock = (uaf->lock | af.lock) & feature; | |
716 | old_lock = af.lock & feature; | |
717 | ||
718 | /* are we changing a locked feature? */ | |
4547b3bc | 719 | if (old_lock && (new_feature != old_feature)) { |
b0fed402 EP |
720 | audit_log_feature_change(i, old_feature, new_feature, |
721 | old_lock, new_lock, 0); | |
722 | return -EPERM; | |
723 | } | |
724 | } | |
725 | /* nothing invalid, do the changes */ | |
726 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
727 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
728 | u32 old_feature, new_feature, old_lock, new_lock; | |
729 | ||
730 | /* if we are not changing this feature, move along */ | |
731 | if (!(feature & uaf->mask)) | |
732 | continue; | |
733 | ||
734 | old_feature = af.features & feature; | |
735 | new_feature = uaf->features & feature; | |
736 | old_lock = af.lock & feature; | |
737 | new_lock = (uaf->lock | af.lock) & feature; | |
738 | ||
739 | if (new_feature != old_feature) | |
740 | audit_log_feature_change(i, old_feature, new_feature, | |
741 | old_lock, new_lock, 1); | |
742 | ||
743 | if (new_feature) | |
744 | af.features |= feature; | |
745 | else | |
746 | af.features &= ~feature; | |
747 | af.lock |= new_lock; | |
748 | } | |
749 | ||
750 | return 0; | |
751 | } | |
752 | ||
1da177e4 LT |
753 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
754 | { | |
dc9eb698 | 755 | u32 seq; |
1da177e4 | 756 | void *data; |
1da177e4 | 757 | int err; |
c0404993 | 758 | struct audit_buffer *ab; |
1da177e4 | 759 | u16 msg_type = nlh->nlmsg_type; |
e1396065 | 760 | struct audit_sig_info *sig_data; |
50397bd1 | 761 | char *ctx = NULL; |
e1396065 | 762 | u32 len; |
1da177e4 | 763 | |
c7bdb545 | 764 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
765 | if (err) |
766 | return err; | |
767 | ||
b0dd25a8 RD |
768 | /* As soon as there's any sign of userspace auditd, |
769 | * start kauditd to talk to it */ | |
13f51e1c | 770 | if (!kauditd_task) { |
b7d11258 | 771 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
13f51e1c G |
772 | if (IS_ERR(kauditd_task)) { |
773 | err = PTR_ERR(kauditd_task); | |
774 | kauditd_task = NULL; | |
775 | return err; | |
776 | } | |
b7d11258 | 777 | } |
1da177e4 | 778 | seq = nlh->nlmsg_seq; |
c64e66c6 | 779 | data = nlmsg_data(nlh); |
1da177e4 LT |
780 | |
781 | switch (msg_type) { | |
09f883a9 RGB |
782 | case AUDIT_GET: { |
783 | struct audit_status s; | |
784 | memset(&s, 0, sizeof(s)); | |
785 | s.enabled = audit_enabled; | |
786 | s.failure = audit_failure; | |
787 | s.pid = audit_pid; | |
788 | s.rate_limit = audit_rate_limit; | |
789 | s.backlog_limit = audit_backlog_limit; | |
790 | s.lost = atomic_read(&audit_lost); | |
791 | s.backlog = skb_queue_len(&audit_skb_queue); | |
51cc83f0 RGB |
792 | s.version = 2; |
793 | s.backlog_wait_time = audit_backlog_wait_time; | |
15e47304 | 794 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, |
09f883a9 | 795 | &s, sizeof(s)); |
1da177e4 | 796 | break; |
09f883a9 RGB |
797 | } |
798 | case AUDIT_SET: { | |
799 | struct audit_status s; | |
800 | memset(&s, 0, sizeof(s)); | |
801 | /* guard against past and future API changes */ | |
802 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); | |
803 | if (s.mask & AUDIT_STATUS_ENABLED) { | |
804 | err = audit_set_enabled(s.enabled); | |
20c6aaa3 | 805 | if (err < 0) |
806 | return err; | |
1da177e4 | 807 | } |
09f883a9 RGB |
808 | if (s.mask & AUDIT_STATUS_FAILURE) { |
809 | err = audit_set_failure(s.failure); | |
20c6aaa3 | 810 | if (err < 0) |
811 | return err; | |
1da177e4 | 812 | } |
09f883a9 RGB |
813 | if (s.mask & AUDIT_STATUS_PID) { |
814 | int new_pid = s.pid; | |
1a6b9f23 EP |
815 | |
816 | if (audit_enabled != AUDIT_OFF) | |
dc9eb698 | 817 | audit_log_config_change("audit_pid", new_pid, audit_pid, 1); |
1a6b9f23 | 818 | audit_pid = new_pid; |
15e47304 | 819 | audit_nlk_portid = NETLINK_CB(skb).portid; |
33faba7f | 820 | audit_sock = NETLINK_CB(skb).sk; |
1da177e4 | 821 | } |
09f883a9 RGB |
822 | if (s.mask & AUDIT_STATUS_RATE_LIMIT) { |
823 | err = audit_set_rate_limit(s.rate_limit); | |
20c6aaa3 | 824 | if (err < 0) |
825 | return err; | |
826 | } | |
51cc83f0 | 827 | if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) { |
09f883a9 | 828 | err = audit_set_backlog_limit(s.backlog_limit); |
51cc83f0 RGB |
829 | if (err < 0) |
830 | return err; | |
831 | } | |
832 | switch (s.version) { | |
833 | /* add future vers # cases immediately below and allow | |
834 | * to fall through */ | |
835 | case 2: | |
836 | if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) { | |
837 | if (sizeof(s) > (size_t)nlh->nlmsg_len) | |
838 | return -EINVAL; | |
839 | if (s.backlog_wait_time < 0 || | |
840 | s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME) | |
841 | return -EINVAL; | |
842 | err = audit_set_backlog_wait_time(s.backlog_wait_time); | |
843 | if (err < 0) | |
844 | return err; | |
845 | } | |
846 | default: | |
847 | break; | |
848 | } | |
1da177e4 | 849 | break; |
09f883a9 | 850 | } |
b0fed402 EP |
851 | case AUDIT_GET_FEATURE: |
852 | err = audit_get_feature(skb); | |
853 | if (err) | |
854 | return err; | |
855 | break; | |
856 | case AUDIT_SET_FEATURE: | |
857 | err = audit_set_feature(skb); | |
858 | if (err) | |
859 | return err; | |
860 | break; | |
05474106 | 861 | case AUDIT_USER: |
039b6b3e RD |
862 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
863 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
864 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
865 | return 0; | |
866 | ||
62062cf8 | 867 | err = audit_filter_user(msg_type); |
4a4cd633 DW |
868 | if (err == 1) { |
869 | err = 0; | |
522ed776 | 870 | if (msg_type == AUDIT_USER_TTY) { |
152f497b | 871 | err = tty_audit_push_current(); |
522ed776 MT |
872 | if (err) |
873 | break; | |
874 | } | |
dc9eb698 | 875 | audit_log_common_recv_msg(&ab, msg_type); |
50397bd1 | 876 | if (msg_type != AUDIT_USER_TTY) |
b50eba7e RGB |
877 | audit_log_format(ab, " msg='%.*s'", |
878 | AUDIT_MESSAGE_TEXT_MAX, | |
50397bd1 EP |
879 | (char *)data); |
880 | else { | |
881 | int size; | |
882 | ||
f7616102 | 883 | audit_log_format(ab, " data="); |
50397bd1 | 884 | size = nlmsg_len(nlh); |
55ad2f8d MT |
885 | if (size > 0 && |
886 | ((unsigned char *)data)[size - 1] == '\0') | |
887 | size--; | |
b556f8ad | 888 | audit_log_n_untrustedstring(ab, data, size); |
4a4cd633 | 889 | } |
f9441639 | 890 | audit_set_portid(ab, NETLINK_CB(skb).portid); |
50397bd1 | 891 | audit_log_end(ab); |
0f45aa18 | 892 | } |
1da177e4 | 893 | break; |
93315ed6 AG |
894 | case AUDIT_ADD_RULE: |
895 | case AUDIT_DEL_RULE: | |
896 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
897 | return -EINVAL; | |
1a6b9f23 | 898 | if (audit_enabled == AUDIT_LOCKED) { |
dc9eb698 EP |
899 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
900 | audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); | |
50397bd1 | 901 | audit_log_end(ab); |
6a01b07f SG |
902 | return -EPERM; |
903 | } | |
93315ed6 AG |
904 | /* fallthrough */ |
905 | case AUDIT_LIST_RULES: | |
15e47304 | 906 | err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid, |
dc9eb698 | 907 | seq, data, nlmsg_len(nlh)); |
1da177e4 | 908 | break; |
74c3cbe3 AV |
909 | case AUDIT_TRIM: |
910 | audit_trim_trees(); | |
dc9eb698 | 911 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
74c3cbe3 AV |
912 | audit_log_format(ab, " op=trim res=1"); |
913 | audit_log_end(ab); | |
914 | break; | |
915 | case AUDIT_MAKE_EQUIV: { | |
916 | void *bufp = data; | |
917 | u32 sizes[2]; | |
7719e437 | 918 | size_t msglen = nlmsg_len(nlh); |
74c3cbe3 AV |
919 | char *old, *new; |
920 | ||
921 | err = -EINVAL; | |
7719e437 | 922 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
923 | break; |
924 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
925 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
926 | msglen -= 2 * sizeof(u32); |
927 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
928 | if (IS_ERR(old)) { |
929 | err = PTR_ERR(old); | |
930 | break; | |
931 | } | |
7719e437 | 932 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
933 | if (IS_ERR(new)) { |
934 | err = PTR_ERR(new); | |
935 | kfree(old); | |
936 | break; | |
937 | } | |
938 | /* OK, here comes... */ | |
939 | err = audit_tag_tree(old, new); | |
940 | ||
dc9eb698 | 941 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
50397bd1 | 942 | |
74c3cbe3 AV |
943 | audit_log_format(ab, " op=make_equiv old="); |
944 | audit_log_untrustedstring(ab, old); | |
945 | audit_log_format(ab, " new="); | |
946 | audit_log_untrustedstring(ab, new); | |
947 | audit_log_format(ab, " res=%d", !err); | |
948 | audit_log_end(ab); | |
949 | kfree(old); | |
950 | kfree(new); | |
951 | break; | |
952 | } | |
c2f0c7c3 | 953 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
954 | len = 0; |
955 | if (audit_sig_sid) { | |
956 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
957 | if (err) | |
958 | return err; | |
959 | } | |
e1396065 AV |
960 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
961 | if (!sig_data) { | |
939cbf26 EP |
962 | if (audit_sig_sid) |
963 | security_release_secctx(ctx, len); | |
e1396065 AV |
964 | return -ENOMEM; |
965 | } | |
cca080d9 | 966 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
e1396065 | 967 | sig_data->pid = audit_sig_pid; |
939cbf26 EP |
968 | if (audit_sig_sid) { |
969 | memcpy(sig_data->ctx, ctx, len); | |
970 | security_release_secctx(ctx, len); | |
971 | } | |
15e47304 | 972 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO, |
e1396065 AV |
973 | 0, 0, sig_data, sizeof(*sig_data) + len); |
974 | kfree(sig_data); | |
c2f0c7c3 | 975 | break; |
522ed776 MT |
976 | case AUDIT_TTY_GET: { |
977 | struct audit_tty_status s; | |
8aa14b64 EB |
978 | struct task_struct *tsk = current; |
979 | ||
7173c54e | 980 | spin_lock(&tsk->sighand->siglock); |
b95d77fe | 981 | s.enabled = tsk->signal->audit_tty; |
46e959ea | 982 | s.log_passwd = tsk->signal->audit_tty_log_passwd; |
7173c54e | 983 | spin_unlock(&tsk->sighand->siglock); |
8aa14b64 | 984 | |
aecdc33e | 985 | audit_send_reply(NETLINK_CB(skb).portid, seq, |
8aa14b64 | 986 | AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
522ed776 MT |
987 | break; |
988 | } | |
989 | case AUDIT_TTY_SET: { | |
46e959ea | 990 | struct audit_tty_status s; |
8aa14b64 | 991 | struct task_struct *tsk = current; |
522ed776 | 992 | |
46e959ea RGB |
993 | memset(&s, 0, sizeof(s)); |
994 | /* guard against past and future API changes */ | |
4d8fe737 | 995 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); |
46e959ea RGB |
996 | if ((s.enabled != 0 && s.enabled != 1) || |
997 | (s.log_passwd != 0 && s.log_passwd != 1)) | |
522ed776 | 998 | return -EINVAL; |
8aa14b64 | 999 | |
7173c54e | 1000 | spin_lock(&tsk->sighand->siglock); |
46e959ea RGB |
1001 | tsk->signal->audit_tty = s.enabled; |
1002 | tsk->signal->audit_tty_log_passwd = s.log_passwd; | |
7173c54e | 1003 | spin_unlock(&tsk->sighand->siglock); |
522ed776 MT |
1004 | break; |
1005 | } | |
1da177e4 LT |
1006 | default: |
1007 | err = -EINVAL; | |
1008 | break; | |
1009 | } | |
1010 | ||
1011 | return err < 0 ? err : 0; | |
1012 | } | |
1013 | ||
b0dd25a8 | 1014 | /* |
ea7ae60b EP |
1015 | * Get message from skb. Each message is processed by audit_receive_msg. |
1016 | * Malformed skbs with wrong length are discarded silently. | |
b0dd25a8 | 1017 | */ |
2a0a6ebe | 1018 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 | 1019 | { |
ea7ae60b EP |
1020 | struct nlmsghdr *nlh; |
1021 | /* | |
94191213 | 1022 | * len MUST be signed for nlmsg_next to be able to dec it below 0 |
ea7ae60b EP |
1023 | * if the nlmsg_len was not aligned |
1024 | */ | |
1025 | int len; | |
1026 | int err; | |
1027 | ||
1028 | nlh = nlmsg_hdr(skb); | |
1029 | len = skb->len; | |
1030 | ||
94191213 | 1031 | while (nlmsg_ok(nlh, len)) { |
ea7ae60b EP |
1032 | err = audit_receive_msg(skb, nlh); |
1033 | /* if err or if this message says it wants a response */ | |
1034 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
1da177e4 | 1035 | netlink_ack(skb, nlh, err); |
ea7ae60b | 1036 | |
2851da57 | 1037 | nlh = nlmsg_next(nlh, &len); |
1da177e4 | 1038 | } |
1da177e4 LT |
1039 | } |
1040 | ||
1041 | /* Receive messages from netlink socket. */ | |
cd40b7d3 | 1042 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 1043 | { |
f368c07d | 1044 | mutex_lock(&audit_cmd_mutex); |
cd40b7d3 | 1045 | audit_receive_skb(skb); |
f368c07d | 1046 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
1047 | } |
1048 | ||
33faba7f | 1049 | static int __net_init audit_net_init(struct net *net) |
1da177e4 | 1050 | { |
a31f2d17 PNA |
1051 | struct netlink_kernel_cfg cfg = { |
1052 | .input = audit_receive, | |
1053 | }; | |
f368c07d | 1054 | |
33faba7f RGB |
1055 | struct audit_net *aunet = net_generic(net, audit_net_id); |
1056 | ||
1057 | pr_info("audit: initializing netlink socket in namespace\n"); | |
1058 | ||
1059 | aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg); | |
1060 | if (aunet->nlsk == NULL) | |
1061 | return -ENOMEM; | |
1062 | if (!aunet->nlsk) | |
1063 | audit_panic("cannot initialize netlink socket in namespace"); | |
1064 | else | |
1065 | aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; | |
1066 | return 0; | |
1067 | } | |
1068 | ||
1069 | static void __net_exit audit_net_exit(struct net *net) | |
1070 | { | |
1071 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
1072 | struct sock *sock = aunet->nlsk; | |
1073 | if (sock == audit_sock) { | |
1074 | audit_pid = 0; | |
1075 | audit_sock = NULL; | |
1076 | } | |
1077 | ||
1078 | rcu_assign_pointer(aunet->nlsk, NULL); | |
1079 | synchronize_net(); | |
1080 | netlink_kernel_release(sock); | |
1081 | } | |
1082 | ||
1083 | static struct pernet_operations __net_initdata audit_net_ops = { | |
1084 | .init = audit_net_init, | |
1085 | .exit = audit_net_exit, | |
1086 | .id = &audit_net_id, | |
1087 | .size = sizeof(struct audit_net), | |
1088 | }; | |
1089 | ||
1090 | /* Initialize audit support at boot time. */ | |
1091 | static int __init audit_init(void) | |
1092 | { | |
1093 | int i; | |
1094 | ||
a3f07114 EP |
1095 | if (audit_initialized == AUDIT_DISABLED) |
1096 | return 0; | |
1097 | ||
33faba7f | 1098 | pr_info("audit: initializing netlink subsys (%s)\n", |
1da177e4 | 1099 | audit_default ? "enabled" : "disabled"); |
33faba7f | 1100 | register_pernet_subsys(&audit_net_ops); |
1da177e4 | 1101 | |
b7d11258 | 1102 | skb_queue_head_init(&audit_skb_queue); |
f3d357b0 | 1103 | skb_queue_head_init(&audit_skb_hold_queue); |
a3f07114 | 1104 | audit_initialized = AUDIT_INITIALIZED; |
1da177e4 | 1105 | audit_enabled = audit_default; |
b593d384 | 1106 | audit_ever_enabled |= !!audit_default; |
3dc7e315 | 1107 | |
9ad9ad38 | 1108 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
f368c07d | 1109 | |
f368c07d AG |
1110 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
1111 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 1112 | |
1da177e4 LT |
1113 | return 0; |
1114 | } | |
1da177e4 LT |
1115 | __initcall(audit_init); |
1116 | ||
1117 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
1118 | static int __init audit_enable(char *str) | |
1119 | { | |
1120 | audit_default = !!simple_strtol(str, NULL, 0); | |
a3f07114 EP |
1121 | if (!audit_default) |
1122 | audit_initialized = AUDIT_DISABLED; | |
1123 | ||
d3ca0344 G |
1124 | pr_info("audit: %s\n", audit_default ? |
1125 | "enabled (after initialization)" : "disabled (until reboot)"); | |
a3f07114 | 1126 | |
9b41046c | 1127 | return 1; |
1da177e4 | 1128 | } |
1da177e4 LT |
1129 | __setup("audit=", audit_enable); |
1130 | ||
f910fde7 RGB |
1131 | /* Process kernel command-line parameter at boot time. |
1132 | * audit_backlog_limit=<n> */ | |
1133 | static int __init audit_backlog_limit_set(char *str) | |
1134 | { | |
1135 | long int audit_backlog_limit_arg; | |
1136 | pr_info("audit_backlog_limit: "); | |
1137 | if (kstrtol(str, 0, &audit_backlog_limit_arg)) { | |
1138 | printk("using default of %d, unable to parse %s\n", | |
1139 | audit_backlog_limit, str); | |
1140 | return 1; | |
1141 | } | |
1142 | if (audit_backlog_limit_arg >= 0) | |
1143 | audit_backlog_limit = (int)audit_backlog_limit_arg; | |
1144 | printk("%d\n", audit_backlog_limit); | |
1145 | ||
1146 | return 1; | |
1147 | } | |
1148 | __setup("audit_backlog_limit=", audit_backlog_limit_set); | |
1149 | ||
16e1904e CW |
1150 | static void audit_buffer_free(struct audit_buffer *ab) |
1151 | { | |
1152 | unsigned long flags; | |
1153 | ||
8fc6115c CW |
1154 | if (!ab) |
1155 | return; | |
1156 | ||
5ac52f33 CW |
1157 | if (ab->skb) |
1158 | kfree_skb(ab->skb); | |
b7d11258 | 1159 | |
16e1904e | 1160 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 1161 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 1162 | kfree(ab); |
5d136a01 SH |
1163 | else { |
1164 | audit_freelist_count++; | |
16e1904e | 1165 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 1166 | } |
16e1904e CW |
1167 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
1168 | } | |
1169 | ||
c0404993 | 1170 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 1171 | gfp_t gfp_mask, int type) |
16e1904e CW |
1172 | { |
1173 | unsigned long flags; | |
1174 | struct audit_buffer *ab = NULL; | |
c0404993 | 1175 | struct nlmsghdr *nlh; |
16e1904e CW |
1176 | |
1177 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
1178 | if (!list_empty(&audit_freelist)) { | |
1179 | ab = list_entry(audit_freelist.next, | |
1180 | struct audit_buffer, list); | |
1181 | list_del(&ab->list); | |
1182 | --audit_freelist_count; | |
1183 | } | |
1184 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
1185 | ||
1186 | if (!ab) { | |
4332bdd3 | 1187 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 1188 | if (!ab) |
8fc6115c | 1189 | goto err; |
16e1904e | 1190 | } |
8fc6115c | 1191 | |
b7d11258 | 1192 | ab->ctx = ctx; |
9ad9ad38 | 1193 | ab->gfp_mask = gfp_mask; |
ee080e6c EP |
1194 | |
1195 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1196 | if (!ab->skb) | |
c64e66c6 | 1197 | goto err; |
ee080e6c | 1198 | |
c64e66c6 DM |
1199 | nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); |
1200 | if (!nlh) | |
1201 | goto out_kfree_skb; | |
ee080e6c | 1202 | |
16e1904e | 1203 | return ab; |
ee080e6c | 1204 | |
c64e66c6 | 1205 | out_kfree_skb: |
ee080e6c EP |
1206 | kfree_skb(ab->skb); |
1207 | ab->skb = NULL; | |
8fc6115c CW |
1208 | err: |
1209 | audit_buffer_free(ab); | |
1210 | return NULL; | |
16e1904e | 1211 | } |
1da177e4 | 1212 | |
b0dd25a8 RD |
1213 | /** |
1214 | * audit_serial - compute a serial number for the audit record | |
1215 | * | |
1216 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1217 | * written to user-space as soon as they are generated, so a complete |
1218 | * audit record may be written in several pieces. The timestamp of the | |
1219 | * record and this serial number are used by the user-space tools to | |
1220 | * determine which pieces belong to the same audit record. The | |
1221 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1222 | * syscall entry to syscall exit. | |
1223 | * | |
bfb4496e DW |
1224 | * NOTE: Another possibility is to store the formatted records off the |
1225 | * audit context (for those records that have a context), and emit them | |
1226 | * all at syscall exit. However, this could delay the reporting of | |
1227 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1228 | * halts). |
1229 | */ | |
bfb4496e DW |
1230 | unsigned int audit_serial(void) |
1231 | { | |
34af946a | 1232 | static DEFINE_SPINLOCK(serial_lock); |
d5b454f2 DW |
1233 | static unsigned int serial = 0; |
1234 | ||
1235 | unsigned long flags; | |
1236 | unsigned int ret; | |
bfb4496e | 1237 | |
d5b454f2 | 1238 | spin_lock_irqsave(&serial_lock, flags); |
bfb4496e | 1239 | do { |
ce625a80 DW |
1240 | ret = ++serial; |
1241 | } while (unlikely(!ret)); | |
d5b454f2 | 1242 | spin_unlock_irqrestore(&serial_lock, flags); |
bfb4496e | 1243 | |
d5b454f2 | 1244 | return ret; |
bfb4496e DW |
1245 | } |
1246 | ||
5600b892 | 1247 | static inline void audit_get_stamp(struct audit_context *ctx, |
bfb4496e DW |
1248 | struct timespec *t, unsigned int *serial) |
1249 | { | |
48887e63 | 1250 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
bfb4496e DW |
1251 | *t = CURRENT_TIME; |
1252 | *serial = audit_serial(); | |
1253 | } | |
1254 | } | |
1255 | ||
82919919 AM |
1256 | /* |
1257 | * Wait for auditd to drain the queue a little | |
1258 | */ | |
ae887e0b | 1259 | static unsigned long wait_for_auditd(unsigned long sleep_time) |
82919919 | 1260 | { |
ae887e0b | 1261 | unsigned long timeout = sleep_time; |
82919919 | 1262 | DECLARE_WAITQUEUE(wait, current); |
f000cfdd | 1263 | set_current_state(TASK_UNINTERRUPTIBLE); |
7ecf69bf | 1264 | add_wait_queue_exclusive(&audit_backlog_wait, &wait); |
82919919 AM |
1265 | |
1266 | if (audit_backlog_limit && | |
1267 | skb_queue_len(&audit_skb_queue) > audit_backlog_limit) | |
ae887e0b | 1268 | timeout = schedule_timeout(sleep_time); |
82919919 AM |
1269 | |
1270 | __set_current_state(TASK_RUNNING); | |
1271 | remove_wait_queue(&audit_backlog_wait, &wait); | |
ae887e0b RGB |
1272 | |
1273 | return timeout; | |
82919919 AM |
1274 | } |
1275 | ||
b0dd25a8 RD |
1276 | /** |
1277 | * audit_log_start - obtain an audit buffer | |
1278 | * @ctx: audit_context (may be NULL) | |
1279 | * @gfp_mask: type of allocation | |
1280 | * @type: audit message type | |
1281 | * | |
1282 | * Returns audit_buffer pointer on success or NULL on error. | |
1283 | * | |
1284 | * Obtain an audit buffer. This routine does locking to obtain the | |
1285 | * audit buffer, but then no locking is required for calls to | |
1286 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1287 | * syscall, then the syscall is marked as auditable and an audit record | |
1288 | * will be written at syscall exit. If there is no associated task, then | |
1289 | * task context (ctx) should be NULL. | |
1290 | */ | |
9796fdd8 | 1291 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1292 | int type) |
1da177e4 LT |
1293 | { |
1294 | struct audit_buffer *ab = NULL; | |
1da177e4 | 1295 | struct timespec t; |
ef00be05 | 1296 | unsigned int uninitialized_var(serial); |
9ad9ad38 | 1297 | int reserve; |
ac4cec44 | 1298 | unsigned long timeout_start = jiffies; |
1da177e4 | 1299 | |
a3f07114 | 1300 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1301 | return NULL; |
1302 | ||
c8edc80c DK |
1303 | if (unlikely(audit_filter_type(type))) |
1304 | return NULL; | |
1305 | ||
9ad9ad38 DW |
1306 | if (gfp_mask & __GFP_WAIT) |
1307 | reserve = 0; | |
1308 | else | |
5600b892 | 1309 | reserve = 5; /* Allow atomic callers to go up to five |
9ad9ad38 DW |
1310 | entries over the normal backlog limit */ |
1311 | ||
1312 | while (audit_backlog_limit | |
1313 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { | |
82919919 AM |
1314 | if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) { |
1315 | unsigned long sleep_time; | |
9ad9ad38 | 1316 | |
82919919 AM |
1317 | sleep_time = timeout_start + audit_backlog_wait_time - |
1318 | jiffies; | |
8ac1c8d5 | 1319 | if ((long)sleep_time > 0) { |
ae887e0b RGB |
1320 | sleep_time = wait_for_auditd(sleep_time); |
1321 | if ((long)sleep_time > 0) | |
1322 | continue; | |
8ac1c8d5 | 1323 | } |
9ad9ad38 | 1324 | } |
320f1b1e | 1325 | if (audit_rate_check() && printk_ratelimit()) |
fb19b4c6 DW |
1326 | printk(KERN_WARNING |
1327 | "audit: audit_backlog=%d > " | |
1328 | "audit_backlog_limit=%d\n", | |
1329 | skb_queue_len(&audit_skb_queue), | |
1330 | audit_backlog_limit); | |
1331 | audit_log_lost("backlog limit exceeded"); | |
ac4cec44 DW |
1332 | audit_backlog_wait_time = audit_backlog_wait_overflow; |
1333 | wake_up(&audit_backlog_wait); | |
fb19b4c6 DW |
1334 | return NULL; |
1335 | } | |
1336 | ||
e789e561 RGB |
1337 | audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; |
1338 | ||
9ad9ad38 | 1339 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1340 | if (!ab) { |
1341 | audit_log_lost("out of memory in audit_log_start"); | |
1342 | return NULL; | |
1343 | } | |
1344 | ||
bfb4496e | 1345 | audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6 | 1346 | |
1da177e4 LT |
1347 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
1348 | t.tv_sec, t.tv_nsec/1000000, serial); | |
1349 | return ab; | |
1350 | } | |
1351 | ||
8fc6115c | 1352 | /** |
5ac52f33 | 1353 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1354 | * @ab: audit_buffer |
b0dd25a8 | 1355 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1356 | * |
1357 | * Returns 0 (no space) on failed expansion, or available space if | |
1358 | * successful. | |
1359 | */ | |
e3b926b4 | 1360 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1361 | { |
5ac52f33 | 1362 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1363 | int oldtail = skb_tailroom(skb); |
1364 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1365 | int newtail = skb_tailroom(skb); | |
1366 | ||
5ac52f33 CW |
1367 | if (ret < 0) { |
1368 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1369 | return 0; |
5ac52f33 | 1370 | } |
406a1d86 HX |
1371 | |
1372 | skb->truesize += newtail - oldtail; | |
1373 | return newtail; | |
8fc6115c | 1374 | } |
1da177e4 | 1375 | |
b0dd25a8 RD |
1376 | /* |
1377 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1378 | * room in the audit buffer, more room will be allocated and vsnprint |
1379 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1380 | * can't format message larger than 1024 bytes, so we don't either. |
1381 | */ | |
1da177e4 LT |
1382 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1383 | va_list args) | |
1384 | { | |
1385 | int len, avail; | |
5ac52f33 | 1386 | struct sk_buff *skb; |
eecb0a73 | 1387 | va_list args2; |
1da177e4 LT |
1388 | |
1389 | if (!ab) | |
1390 | return; | |
1391 | ||
5ac52f33 CW |
1392 | BUG_ON(!ab->skb); |
1393 | skb = ab->skb; | |
1394 | avail = skb_tailroom(skb); | |
1395 | if (avail == 0) { | |
e3b926b4 | 1396 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1397 | if (!avail) |
1398 | goto out; | |
1da177e4 | 1399 | } |
eecb0a73 | 1400 | va_copy(args2, args); |
27a884dc | 1401 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1402 | if (len >= avail) { |
1403 | /* The printk buffer is 1024 bytes long, so if we get | |
1404 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1405 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1406 | avail = audit_expand(ab, |
1407 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1408 | if (!avail) |
a0e86bd4 | 1409 | goto out_va_end; |
27a884dc | 1410 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1411 | } |
168b7173 SG |
1412 | if (len > 0) |
1413 | skb_put(skb, len); | |
a0e86bd4 JJ |
1414 | out_va_end: |
1415 | va_end(args2); | |
8fc6115c CW |
1416 | out: |
1417 | return; | |
1da177e4 LT |
1418 | } |
1419 | ||
b0dd25a8 RD |
1420 | /** |
1421 | * audit_log_format - format a message into the audit buffer. | |
1422 | * @ab: audit_buffer | |
1423 | * @fmt: format string | |
1424 | * @...: optional parameters matching @fmt string | |
1425 | * | |
1426 | * All the work is done in audit_log_vformat. | |
1427 | */ | |
1da177e4 LT |
1428 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1429 | { | |
1430 | va_list args; | |
1431 | ||
1432 | if (!ab) | |
1433 | return; | |
1434 | va_start(args, fmt); | |
1435 | audit_log_vformat(ab, fmt, args); | |
1436 | va_end(args); | |
1437 | } | |
1438 | ||
b0dd25a8 RD |
1439 | /** |
1440 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
1441 | * @ab: the audit_buffer | |
1442 | * @buf: buffer to convert to hex | |
1443 | * @len: length of @buf to be converted | |
1444 | * | |
1445 | * No return value; failure to expand is silently ignored. | |
1446 | * | |
1447 | * This function will take the passed buf and convert it into a string of | |
1448 | * ascii hex digits. The new string is placed onto the skb. | |
1449 | */ | |
b556f8ad | 1450 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1451 | size_t len) |
83c7d091 | 1452 | { |
168b7173 SG |
1453 | int i, avail, new_len; |
1454 | unsigned char *ptr; | |
1455 | struct sk_buff *skb; | |
1456 | static const unsigned char *hex = "0123456789ABCDEF"; | |
1457 | ||
8ef2d304 AG |
1458 | if (!ab) |
1459 | return; | |
1460 | ||
168b7173 SG |
1461 | BUG_ON(!ab->skb); |
1462 | skb = ab->skb; | |
1463 | avail = skb_tailroom(skb); | |
1464 | new_len = len<<1; | |
1465 | if (new_len >= avail) { | |
1466 | /* Round the buffer request up to the next multiple */ | |
1467 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1468 | avail = audit_expand(ab, new_len); | |
1469 | if (!avail) | |
1470 | return; | |
1471 | } | |
83c7d091 | 1472 | |
27a884dc | 1473 | ptr = skb_tail_pointer(skb); |
168b7173 SG |
1474 | for (i=0; i<len; i++) { |
1475 | *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ | |
1476 | *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ | |
1477 | } | |
1478 | *ptr = 0; | |
1479 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 | 1480 | } |
1481 | ||
9c937dcc AG |
1482 | /* |
1483 | * Format a string of no more than slen characters into the audit buffer, | |
1484 | * enclosed in quote marks. | |
1485 | */ | |
b556f8ad EP |
1486 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1487 | size_t slen) | |
9c937dcc AG |
1488 | { |
1489 | int avail, new_len; | |
1490 | unsigned char *ptr; | |
1491 | struct sk_buff *skb; | |
1492 | ||
8ef2d304 AG |
1493 | if (!ab) |
1494 | return; | |
1495 | ||
9c937dcc AG |
1496 | BUG_ON(!ab->skb); |
1497 | skb = ab->skb; | |
1498 | avail = skb_tailroom(skb); | |
1499 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1500 | if (new_len > avail) { | |
1501 | avail = audit_expand(ab, new_len); | |
1502 | if (!avail) | |
1503 | return; | |
1504 | } | |
27a884dc | 1505 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1506 | *ptr++ = '"'; |
1507 | memcpy(ptr, string, slen); | |
1508 | ptr += slen; | |
1509 | *ptr++ = '"'; | |
1510 | *ptr = 0; | |
1511 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1512 | } | |
1513 | ||
de6bbd1d EP |
1514 | /** |
1515 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1516 | * @string: string to be checked |
1517 | * @len: max length of the string to check | |
de6bbd1d EP |
1518 | */ |
1519 | int audit_string_contains_control(const char *string, size_t len) | |
1520 | { | |
1521 | const unsigned char *p; | |
b3897f56 | 1522 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1523 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
de6bbd1d EP |
1524 | return 1; |
1525 | } | |
1526 | return 0; | |
1527 | } | |
1528 | ||
b0dd25a8 | 1529 | /** |
522ed776 | 1530 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1531 | * @ab: audit_buffer |
f706d5d2 | 1532 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1533 | * @string: string to be logged |
1534 | * | |
1535 | * This code will escape a string that is passed to it if the string | |
1536 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1537 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1538 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1539 | * |
1540 | * The caller specifies the number of characters in the string to log, which may | |
1541 | * or may not be the entire string. | |
b0dd25a8 | 1542 | */ |
b556f8ad EP |
1543 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
1544 | size_t len) | |
83c7d091 | 1545 | { |
de6bbd1d | 1546 | if (audit_string_contains_control(string, len)) |
b556f8ad | 1547 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 1548 | else |
b556f8ad | 1549 | audit_log_n_string(ab, string, len); |
83c7d091 | 1550 | } |
1551 | ||
9c937dcc | 1552 | /** |
522ed776 | 1553 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
1554 | * @ab: audit_buffer |
1555 | * @string: string to be logged | |
1556 | * | |
522ed776 | 1557 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
1558 | * determine string length. |
1559 | */ | |
de6bbd1d | 1560 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 1561 | { |
b556f8ad | 1562 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
1563 | } |
1564 | ||
168b7173 | 1565 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 1566 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 1567 | const struct path *path) |
1da177e4 | 1568 | { |
44707fdf | 1569 | char *p, *pathname; |
1da177e4 | 1570 | |
8fc6115c | 1571 | if (prefix) |
c158a35c | 1572 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 1573 | |
168b7173 | 1574 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
1575 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
1576 | if (!pathname) { | |
def57543 | 1577 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 1578 | return; |
1da177e4 | 1579 | } |
cf28b486 | 1580 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
1581 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
1582 | /* FIXME: can we save some information here? */ | |
def57543 | 1583 | audit_log_string(ab, "<too_long>"); |
5600b892 | 1584 | } else |
168b7173 | 1585 | audit_log_untrustedstring(ab, p); |
44707fdf | 1586 | kfree(pathname); |
1da177e4 LT |
1587 | } |
1588 | ||
4d3fb709 EP |
1589 | void audit_log_session_info(struct audit_buffer *ab) |
1590 | { | |
1591 | u32 sessionid = audit_get_sessionid(current); | |
1592 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); | |
1593 | ||
b8f89caa | 1594 | audit_log_format(ab, " auid=%u ses=%u", auid, sessionid); |
4d3fb709 EP |
1595 | } |
1596 | ||
9d960985 EP |
1597 | void audit_log_key(struct audit_buffer *ab, char *key) |
1598 | { | |
1599 | audit_log_format(ab, " key="); | |
1600 | if (key) | |
1601 | audit_log_untrustedstring(ab, key); | |
1602 | else | |
1603 | audit_log_format(ab, "(null)"); | |
1604 | } | |
1605 | ||
b24a30a7 EP |
1606 | void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) |
1607 | { | |
1608 | int i; | |
1609 | ||
1610 | audit_log_format(ab, " %s=", prefix); | |
1611 | CAP_FOR_EACH_U32(i) { | |
1612 | audit_log_format(ab, "%08x", | |
1613 | cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]); | |
1614 | } | |
1615 | } | |
1616 | ||
1617 | void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) | |
1618 | { | |
1619 | kernel_cap_t *perm = &name->fcap.permitted; | |
1620 | kernel_cap_t *inh = &name->fcap.inheritable; | |
1621 | int log = 0; | |
1622 | ||
1623 | if (!cap_isclear(*perm)) { | |
1624 | audit_log_cap(ab, "cap_fp", perm); | |
1625 | log = 1; | |
1626 | } | |
1627 | if (!cap_isclear(*inh)) { | |
1628 | audit_log_cap(ab, "cap_fi", inh); | |
1629 | log = 1; | |
1630 | } | |
1631 | ||
1632 | if (log) | |
1633 | audit_log_format(ab, " cap_fe=%d cap_fver=%x", | |
1634 | name->fcap.fE, name->fcap_ver); | |
1635 | } | |
1636 | ||
1637 | static inline int audit_copy_fcaps(struct audit_names *name, | |
1638 | const struct dentry *dentry) | |
1639 | { | |
1640 | struct cpu_vfs_cap_data caps; | |
1641 | int rc; | |
1642 | ||
1643 | if (!dentry) | |
1644 | return 0; | |
1645 | ||
1646 | rc = get_vfs_caps_from_disk(dentry, &caps); | |
1647 | if (rc) | |
1648 | return rc; | |
1649 | ||
1650 | name->fcap.permitted = caps.permitted; | |
1651 | name->fcap.inheritable = caps.inheritable; | |
1652 | name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); | |
1653 | name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> | |
1654 | VFS_CAP_REVISION_SHIFT; | |
1655 | ||
1656 | return 0; | |
1657 | } | |
1658 | ||
1659 | /* Copy inode data into an audit_names. */ | |
1660 | void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, | |
1661 | const struct inode *inode) | |
1662 | { | |
1663 | name->ino = inode->i_ino; | |
1664 | name->dev = inode->i_sb->s_dev; | |
1665 | name->mode = inode->i_mode; | |
1666 | name->uid = inode->i_uid; | |
1667 | name->gid = inode->i_gid; | |
1668 | name->rdev = inode->i_rdev; | |
1669 | security_inode_getsecid(inode, &name->osid); | |
1670 | audit_copy_fcaps(name, dentry); | |
1671 | } | |
1672 | ||
1673 | /** | |
1674 | * audit_log_name - produce AUDIT_PATH record from struct audit_names | |
1675 | * @context: audit_context for the task | |
1676 | * @n: audit_names structure with reportable details | |
1677 | * @path: optional path to report instead of audit_names->name | |
1678 | * @record_num: record number to report when handling a list of names | |
1679 | * @call_panic: optional pointer to int that will be updated if secid fails | |
1680 | */ | |
1681 | void audit_log_name(struct audit_context *context, struct audit_names *n, | |
1682 | struct path *path, int record_num, int *call_panic) | |
1683 | { | |
1684 | struct audit_buffer *ab; | |
1685 | ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); | |
1686 | if (!ab) | |
1687 | return; | |
1688 | ||
1689 | audit_log_format(ab, "item=%d", record_num); | |
1690 | ||
1691 | if (path) | |
1692 | audit_log_d_path(ab, " name=", path); | |
1693 | else if (n->name) { | |
1694 | switch (n->name_len) { | |
1695 | case AUDIT_NAME_FULL: | |
1696 | /* log the full path */ | |
1697 | audit_log_format(ab, " name="); | |
1698 | audit_log_untrustedstring(ab, n->name->name); | |
1699 | break; | |
1700 | case 0: | |
1701 | /* name was specified as a relative path and the | |
1702 | * directory component is the cwd */ | |
1703 | audit_log_d_path(ab, " name=", &context->pwd); | |
1704 | break; | |
1705 | default: | |
1706 | /* log the name's directory component */ | |
1707 | audit_log_format(ab, " name="); | |
1708 | audit_log_n_untrustedstring(ab, n->name->name, | |
1709 | n->name_len); | |
1710 | } | |
1711 | } else | |
1712 | audit_log_format(ab, " name=(null)"); | |
1713 | ||
1714 | if (n->ino != (unsigned long)-1) { | |
1715 | audit_log_format(ab, " inode=%lu" | |
1716 | " dev=%02x:%02x mode=%#ho" | |
1717 | " ouid=%u ogid=%u rdev=%02x:%02x", | |
1718 | n->ino, | |
1719 | MAJOR(n->dev), | |
1720 | MINOR(n->dev), | |
1721 | n->mode, | |
1722 | from_kuid(&init_user_ns, n->uid), | |
1723 | from_kgid(&init_user_ns, n->gid), | |
1724 | MAJOR(n->rdev), | |
1725 | MINOR(n->rdev)); | |
1726 | } | |
1727 | if (n->osid != 0) { | |
1728 | char *ctx = NULL; | |
1729 | u32 len; | |
1730 | if (security_secid_to_secctx( | |
1731 | n->osid, &ctx, &len)) { | |
1732 | audit_log_format(ab, " osid=%u", n->osid); | |
1733 | if (call_panic) | |
1734 | *call_panic = 2; | |
1735 | } else { | |
1736 | audit_log_format(ab, " obj=%s", ctx); | |
1737 | security_release_secctx(ctx, len); | |
1738 | } | |
1739 | } | |
1740 | ||
d3aea84a JL |
1741 | /* log the audit_names record type */ |
1742 | audit_log_format(ab, " nametype="); | |
1743 | switch(n->type) { | |
1744 | case AUDIT_TYPE_NORMAL: | |
1745 | audit_log_format(ab, "NORMAL"); | |
1746 | break; | |
1747 | case AUDIT_TYPE_PARENT: | |
1748 | audit_log_format(ab, "PARENT"); | |
1749 | break; | |
1750 | case AUDIT_TYPE_CHILD_DELETE: | |
1751 | audit_log_format(ab, "DELETE"); | |
1752 | break; | |
1753 | case AUDIT_TYPE_CHILD_CREATE: | |
1754 | audit_log_format(ab, "CREATE"); | |
1755 | break; | |
1756 | default: | |
1757 | audit_log_format(ab, "UNKNOWN"); | |
1758 | break; | |
1759 | } | |
1760 | ||
b24a30a7 EP |
1761 | audit_log_fcaps(ab, n); |
1762 | audit_log_end(ab); | |
1763 | } | |
1764 | ||
1765 | int audit_log_task_context(struct audit_buffer *ab) | |
1766 | { | |
1767 | char *ctx = NULL; | |
1768 | unsigned len; | |
1769 | int error; | |
1770 | u32 sid; | |
1771 | ||
1772 | security_task_getsecid(current, &sid); | |
1773 | if (!sid) | |
1774 | return 0; | |
1775 | ||
1776 | error = security_secid_to_secctx(sid, &ctx, &len); | |
1777 | if (error) { | |
1778 | if (error != -EINVAL) | |
1779 | goto error_path; | |
1780 | return 0; | |
1781 | } | |
1782 | ||
1783 | audit_log_format(ab, " subj=%s", ctx); | |
1784 | security_release_secctx(ctx, len); | |
1785 | return 0; | |
1786 | ||
1787 | error_path: | |
1788 | audit_panic("error in audit_log_task_context"); | |
1789 | return error; | |
1790 | } | |
1791 | EXPORT_SYMBOL(audit_log_task_context); | |
1792 | ||
1793 | void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) | |
1794 | { | |
1795 | const struct cred *cred; | |
1796 | char name[sizeof(tsk->comm)]; | |
1797 | struct mm_struct *mm = tsk->mm; | |
1798 | char *tty; | |
1799 | ||
1800 | if (!ab) | |
1801 | return; | |
1802 | ||
1803 | /* tsk == current */ | |
1804 | cred = current_cred(); | |
1805 | ||
1806 | spin_lock_irq(&tsk->sighand->siglock); | |
1807 | if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) | |
1808 | tty = tsk->signal->tty->name; | |
1809 | else | |
1810 | tty = "(none)"; | |
1811 | spin_unlock_irq(&tsk->sighand->siglock); | |
1812 | ||
1813 | audit_log_format(ab, | |
1814 | " ppid=%ld pid=%d auid=%u uid=%u gid=%u" | |
1815 | " euid=%u suid=%u fsuid=%u" | |
2f2ad101 | 1816 | " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", |
b24a30a7 EP |
1817 | sys_getppid(), |
1818 | tsk->pid, | |
1819 | from_kuid(&init_user_ns, audit_get_loginuid(tsk)), | |
1820 | from_kuid(&init_user_ns, cred->uid), | |
1821 | from_kgid(&init_user_ns, cred->gid), | |
1822 | from_kuid(&init_user_ns, cred->euid), | |
1823 | from_kuid(&init_user_ns, cred->suid), | |
1824 | from_kuid(&init_user_ns, cred->fsuid), | |
1825 | from_kgid(&init_user_ns, cred->egid), | |
1826 | from_kgid(&init_user_ns, cred->sgid), | |
1827 | from_kgid(&init_user_ns, cred->fsgid), | |
2f2ad101 | 1828 | tty, audit_get_sessionid(tsk)); |
b24a30a7 EP |
1829 | |
1830 | get_task_comm(name, tsk); | |
1831 | audit_log_format(ab, " comm="); | |
1832 | audit_log_untrustedstring(ab, name); | |
1833 | ||
1834 | if (mm) { | |
1835 | down_read(&mm->mmap_sem); | |
1836 | if (mm->exe_file) | |
1837 | audit_log_d_path(ab, " exe=", &mm->exe_file->f_path); | |
1838 | up_read(&mm->mmap_sem); | |
1839 | } | |
1840 | audit_log_task_context(ab); | |
1841 | } | |
1842 | EXPORT_SYMBOL(audit_log_task_info); | |
1843 | ||
a51d9eaa KC |
1844 | /** |
1845 | * audit_log_link_denied - report a link restriction denial | |
1846 | * @operation: specific link opreation | |
1847 | * @link: the path that triggered the restriction | |
1848 | */ | |
1849 | void audit_log_link_denied(const char *operation, struct path *link) | |
1850 | { | |
1851 | struct audit_buffer *ab; | |
b24a30a7 EP |
1852 | struct audit_names *name; |
1853 | ||
1854 | name = kzalloc(sizeof(*name), GFP_NOFS); | |
1855 | if (!name) | |
1856 | return; | |
a51d9eaa | 1857 | |
b24a30a7 | 1858 | /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ |
a51d9eaa KC |
1859 | ab = audit_log_start(current->audit_context, GFP_KERNEL, |
1860 | AUDIT_ANOM_LINK); | |
d1c7d97a | 1861 | if (!ab) |
b24a30a7 EP |
1862 | goto out; |
1863 | audit_log_format(ab, "op=%s", operation); | |
1864 | audit_log_task_info(ab, current); | |
1865 | audit_log_format(ab, " res=0"); | |
a51d9eaa | 1866 | audit_log_end(ab); |
b24a30a7 EP |
1867 | |
1868 | /* Generate AUDIT_PATH record with object. */ | |
1869 | name->type = AUDIT_TYPE_NORMAL; | |
1870 | audit_copy_inode(name, link->dentry, link->dentry->d_inode); | |
1871 | audit_log_name(current->audit_context, name, link, 0, NULL); | |
1872 | out: | |
1873 | kfree(name); | |
a51d9eaa KC |
1874 | } |
1875 | ||
b0dd25a8 RD |
1876 | /** |
1877 | * audit_log_end - end one audit record | |
1878 | * @ab: the audit_buffer | |
1879 | * | |
1880 | * The netlink_* functions cannot be called inside an irq context, so | |
1881 | * the audit buffer is placed on a queue and a tasklet is scheduled to | |
1da177e4 | 1882 | * remove them from the queue outside the irq context. May be called in |
b0dd25a8 RD |
1883 | * any context. |
1884 | */ | |
b7d11258 | 1885 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 1886 | { |
1da177e4 LT |
1887 | if (!ab) |
1888 | return; | |
1889 | if (!audit_rate_check()) { | |
1890 | audit_log_lost("rate limit exceeded"); | |
1891 | } else { | |
8d07a67c | 1892 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
94191213 | 1893 | nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN; |
f3d357b0 | 1894 | |
b7d11258 | 1895 | if (audit_pid) { |
b7d11258 | 1896 | skb_queue_tail(&audit_skb_queue, ab->skb); |
b7d11258 | 1897 | wake_up_interruptible(&kauditd_wait); |
f3d357b0 | 1898 | } else { |
038cbcf6 | 1899 | audit_printk_skb(ab->skb); |
b7d11258 | 1900 | } |
f3d357b0 | 1901 | ab->skb = NULL; |
1da177e4 | 1902 | } |
16e1904e | 1903 | audit_buffer_free(ab); |
1da177e4 LT |
1904 | } |
1905 | ||
b0dd25a8 RD |
1906 | /** |
1907 | * audit_log - Log an audit record | |
1908 | * @ctx: audit context | |
1909 | * @gfp_mask: type of allocation | |
1910 | * @type: audit message type | |
1911 | * @fmt: format string to use | |
1912 | * @...: variable parameters matching the format string | |
1913 | * | |
1914 | * This is a convenience function that calls audit_log_start, | |
1915 | * audit_log_vformat, and audit_log_end. It may be called | |
1916 | * in any context. | |
1917 | */ | |
5600b892 | 1918 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 1919 | const char *fmt, ...) |
1da177e4 LT |
1920 | { |
1921 | struct audit_buffer *ab; | |
1922 | va_list args; | |
1923 | ||
9ad9ad38 | 1924 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
1925 | if (ab) { |
1926 | va_start(args, fmt); | |
1927 | audit_log_vformat(ab, fmt, args); | |
1928 | va_end(args); | |
1929 | audit_log_end(ab); | |
1930 | } | |
1931 | } | |
bf45da97 | 1932 | |
131ad62d MDF |
1933 | #ifdef CONFIG_SECURITY |
1934 | /** | |
1935 | * audit_log_secctx - Converts and logs SELinux context | |
1936 | * @ab: audit_buffer | |
1937 | * @secid: security number | |
1938 | * | |
1939 | * This is a helper function that calls security_secid_to_secctx to convert | |
1940 | * secid to secctx and then adds the (converted) SELinux context to the audit | |
1941 | * log by calling audit_log_format, thus also preventing leak of internal secid | |
1942 | * to userspace. If secid cannot be converted audit_panic is called. | |
1943 | */ | |
1944 | void audit_log_secctx(struct audit_buffer *ab, u32 secid) | |
1945 | { | |
1946 | u32 len; | |
1947 | char *secctx; | |
1948 | ||
1949 | if (security_secid_to_secctx(secid, &secctx, &len)) { | |
1950 | audit_panic("Cannot convert secid to context"); | |
1951 | } else { | |
1952 | audit_log_format(ab, " obj=%s", secctx); | |
1953 | security_release_secctx(secctx, len); | |
1954 | } | |
1955 | } | |
1956 | EXPORT_SYMBOL(audit_log_secctx); | |
1957 | #endif | |
1958 | ||
bf45da97 | 1959 | EXPORT_SYMBOL(audit_log_start); |
1960 | EXPORT_SYMBOL(audit_log_end); | |
1961 | EXPORT_SYMBOL(audit_log_format); | |
1962 | EXPORT_SYMBOL(audit_log); |