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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 | |
51cc83f0 RGB |
337 | static int audit_set_backlog_wait_time(int timeout) |
338 | { | |
339 | return audit_do_config_change("audit_backlog_wait_time", | |
340 | &audit_backlog_wait_time, timeout); | |
341 | } | |
342 | ||
dc9eb698 | 343 | static int audit_set_enabled(int state) |
1a6b9f23 | 344 | { |
b593d384 | 345 | int rc; |
1a6b9f23 EP |
346 | if (state < AUDIT_OFF || state > AUDIT_LOCKED) |
347 | return -EINVAL; | |
6a01b07f | 348 | |
dc9eb698 | 349 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
b593d384 EP |
350 | if (!rc) |
351 | audit_ever_enabled |= !!state; | |
352 | ||
353 | return rc; | |
1da177e4 LT |
354 | } |
355 | ||
dc9eb698 | 356 | static int audit_set_failure(int state) |
1da177e4 | 357 | { |
1da177e4 LT |
358 | if (state != AUDIT_FAIL_SILENT |
359 | && state != AUDIT_FAIL_PRINTK | |
360 | && state != AUDIT_FAIL_PANIC) | |
361 | return -EINVAL; | |
ce29b682 | 362 | |
dc9eb698 | 363 | return audit_do_config_change("audit_failure", &audit_failure, state); |
1da177e4 LT |
364 | } |
365 | ||
f3d357b0 EP |
366 | /* |
367 | * Queue skbs to be sent to auditd when/if it comes back. These skbs should | |
368 | * already have been sent via prink/syslog and so if these messages are dropped | |
369 | * it is not a huge concern since we already passed the audit_log_lost() | |
370 | * notification and stuff. This is just nice to get audit messages during | |
371 | * boot before auditd is running or messages generated while auditd is stopped. | |
372 | * This only holds messages is audit_default is set, aka booting with audit=1 | |
373 | * or building your kernel that way. | |
374 | */ | |
375 | static void audit_hold_skb(struct sk_buff *skb) | |
376 | { | |
377 | if (audit_default && | |
378 | skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit) | |
379 | skb_queue_tail(&audit_skb_hold_queue, skb); | |
380 | else | |
381 | kfree_skb(skb); | |
382 | } | |
383 | ||
038cbcf6 EP |
384 | /* |
385 | * For one reason or another this nlh isn't getting delivered to the userspace | |
386 | * audit daemon, just send it to printk. | |
387 | */ | |
388 | static void audit_printk_skb(struct sk_buff *skb) | |
389 | { | |
390 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 391 | char *data = nlmsg_data(nlh); |
038cbcf6 EP |
392 | |
393 | if (nlh->nlmsg_type != AUDIT_EOE) { | |
394 | if (printk_ratelimit()) | |
395 | printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data); | |
396 | else | |
397 | audit_log_lost("printk limit exceeded\n"); | |
398 | } | |
399 | ||
400 | audit_hold_skb(skb); | |
401 | } | |
402 | ||
f3d357b0 EP |
403 | static void kauditd_send_skb(struct sk_buff *skb) |
404 | { | |
405 | int err; | |
406 | /* take a reference in case we can't send it and we want to hold it */ | |
407 | skb_get(skb); | |
15e47304 | 408 | err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0); |
f3d357b0 | 409 | if (err < 0) { |
c9404c9c | 410 | BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */ |
f3d357b0 | 411 | printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); |
9db3b9bc | 412 | audit_log_lost("auditd disappeared\n"); |
f3d357b0 | 413 | audit_pid = 0; |
33faba7f | 414 | audit_sock = NULL; |
f3d357b0 EP |
415 | /* we might get lucky and get this in the next auditd */ |
416 | audit_hold_skb(skb); | |
417 | } else | |
418 | /* drop the extra reference if sent ok */ | |
70d4bf6d | 419 | consume_skb(skb); |
f3d357b0 EP |
420 | } |
421 | ||
b551d1d9 RGB |
422 | /* |
423 | * flush_hold_queue - empty the hold queue if auditd appears | |
424 | * | |
425 | * If auditd just started, drain the queue of messages already | |
426 | * sent to syslog/printk. Remember loss here is ok. We already | |
427 | * called audit_log_lost() if it didn't go out normally. so the | |
428 | * race between the skb_dequeue and the next check for audit_pid | |
429 | * doesn't matter. | |
430 | * | |
431 | * If you ever find kauditd to be too slow we can get a perf win | |
432 | * by doing our own locking and keeping better track if there | |
433 | * are messages in this queue. I don't see the need now, but | |
434 | * in 5 years when I want to play with this again I'll see this | |
435 | * note and still have no friggin idea what i'm thinking today. | |
436 | */ | |
437 | static void flush_hold_queue(void) | |
b7d11258 DW |
438 | { |
439 | struct sk_buff *skb; | |
440 | ||
b551d1d9 RGB |
441 | if (!audit_default || !audit_pid) |
442 | return; | |
443 | ||
444 | skb = skb_dequeue(&audit_skb_hold_queue); | |
445 | if (likely(!skb)) | |
446 | return; | |
447 | ||
448 | while (skb && audit_pid) { | |
449 | kauditd_send_skb(skb); | |
450 | skb = skb_dequeue(&audit_skb_hold_queue); | |
451 | } | |
452 | ||
453 | /* | |
454 | * if auditd just disappeared but we | |
455 | * dequeued an skb we need to drop ref | |
456 | */ | |
457 | if (skb) | |
458 | consume_skb(skb); | |
459 | } | |
460 | ||
97a41e26 | 461 | static int kauditd_thread(void *dummy) |
b7d11258 | 462 | { |
83144186 | 463 | set_freezable(); |
4899b8b1 | 464 | while (!kthread_should_stop()) { |
3320c513 RGB |
465 | struct sk_buff *skb; |
466 | DECLARE_WAITQUEUE(wait, current); | |
467 | ||
b551d1d9 | 468 | flush_hold_queue(); |
f3d357b0 | 469 | |
b7d11258 | 470 | skb = skb_dequeue(&audit_skb_queue); |
db897319 | 471 | |
b7d11258 | 472 | if (skb) { |
db897319 DD |
473 | if (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit) |
474 | wake_up(&audit_backlog_wait); | |
f3d357b0 EP |
475 | if (audit_pid) |
476 | kauditd_send_skb(skb); | |
038cbcf6 EP |
477 | else |
478 | audit_printk_skb(skb); | |
3320c513 RGB |
479 | continue; |
480 | } | |
481 | set_current_state(TASK_INTERRUPTIBLE); | |
482 | add_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 483 | |
3320c513 RGB |
484 | if (!skb_queue_len(&audit_skb_queue)) { |
485 | try_to_freeze(); | |
486 | schedule(); | |
b7d11258 | 487 | } |
3320c513 RGB |
488 | |
489 | __set_current_state(TASK_RUNNING); | |
490 | remove_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 491 | } |
4899b8b1 | 492 | return 0; |
b7d11258 DW |
493 | } |
494 | ||
9044e6bc AV |
495 | int audit_send_list(void *_dest) |
496 | { | |
497 | struct audit_netlink_list *dest = _dest; | |
9044e6bc | 498 | struct sk_buff *skb; |
33faba7f RGB |
499 | struct net *net = get_net_ns_by_pid(dest->pid); |
500 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
9044e6bc AV |
501 | |
502 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
503 | mutex_lock(&audit_cmd_mutex); |
504 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
505 | |
506 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
33faba7f | 507 | netlink_unicast(aunet->nlsk, skb, dest->portid, 0); |
9044e6bc AV |
508 | |
509 | kfree(dest); | |
510 | ||
511 | return 0; | |
512 | } | |
513 | ||
f9441639 | 514 | struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done, |
b8800aa5 | 515 | int multi, const void *payload, int size) |
9044e6bc AV |
516 | { |
517 | struct sk_buff *skb; | |
518 | struct nlmsghdr *nlh; | |
9044e6bc AV |
519 | void *data; |
520 | int flags = multi ? NLM_F_MULTI : 0; | |
521 | int t = done ? NLMSG_DONE : type; | |
522 | ||
ee080e6c | 523 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
524 | if (!skb) |
525 | return NULL; | |
526 | ||
f9441639 | 527 | nlh = nlmsg_put(skb, portid, seq, t, size, flags); |
c64e66c6 DM |
528 | if (!nlh) |
529 | goto out_kfree_skb; | |
530 | data = nlmsg_data(nlh); | |
9044e6bc AV |
531 | memcpy(data, payload, size); |
532 | return skb; | |
533 | ||
c64e66c6 DM |
534 | out_kfree_skb: |
535 | kfree_skb(skb); | |
9044e6bc AV |
536 | return NULL; |
537 | } | |
538 | ||
f09ac9db EP |
539 | static int audit_send_reply_thread(void *arg) |
540 | { | |
541 | struct audit_reply *reply = (struct audit_reply *)arg; | |
33faba7f RGB |
542 | struct net *net = get_net_ns_by_pid(reply->pid); |
543 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
f09ac9db EP |
544 | |
545 | mutex_lock(&audit_cmd_mutex); | |
546 | mutex_unlock(&audit_cmd_mutex); | |
547 | ||
548 | /* Ignore failure. It'll only happen if the sender goes away, | |
549 | because our timeout is set to infinite. */ | |
33faba7f | 550 | netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0); |
f09ac9db EP |
551 | kfree(reply); |
552 | return 0; | |
553 | } | |
b0dd25a8 RD |
554 | /** |
555 | * audit_send_reply - send an audit reply message via netlink | |
f9441639 | 556 | * @portid: netlink port to which to send reply |
b0dd25a8 RD |
557 | * @seq: sequence number |
558 | * @type: audit message type | |
559 | * @done: done (last) flag | |
560 | * @multi: multi-part message flag | |
561 | * @payload: payload data | |
562 | * @size: payload size | |
563 | * | |
f9441639 | 564 | * Allocates an skb, builds the netlink message, and sends it to the port id. |
b0dd25a8 RD |
565 | * No failure notifications. |
566 | */ | |
f9441639 RGB |
567 | static void audit_send_reply(__u32 portid, int seq, int type, int done, |
568 | int multi, const void *payload, int size) | |
1da177e4 | 569 | { |
f09ac9db EP |
570 | struct sk_buff *skb; |
571 | struct task_struct *tsk; | |
572 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), | |
573 | GFP_KERNEL); | |
574 | ||
575 | if (!reply) | |
576 | return; | |
577 | ||
f9441639 | 578 | skb = audit_make_reply(portid, seq, type, done, multi, payload, size); |
1da177e4 | 579 | if (!skb) |
fcaf1eb8 | 580 | goto out; |
f09ac9db | 581 | |
f9441639 | 582 | reply->portid = portid; |
33faba7f | 583 | reply->pid = task_pid_vnr(current); |
f09ac9db EP |
584 | reply->skb = skb; |
585 | ||
586 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
fcaf1eb8 AM |
587 | if (!IS_ERR(tsk)) |
588 | return; | |
589 | kfree_skb(skb); | |
590 | out: | |
591 | kfree(reply); | |
1da177e4 LT |
592 | } |
593 | ||
594 | /* | |
595 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
596 | * control messages. | |
597 | */ | |
c7bdb545 | 598 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
599 | { |
600 | int err = 0; | |
601 | ||
34e36d8e EB |
602 | /* Only support the initial namespaces for now. */ |
603 | if ((current_user_ns() != &init_user_ns) || | |
604 | (task_active_pid_ns(current) != &init_pid_ns)) | |
605 | return -EPERM; | |
606 | ||
1da177e4 | 607 | switch (msg_type) { |
1da177e4 | 608 | case AUDIT_LIST: |
1da177e4 LT |
609 | case AUDIT_ADD: |
610 | case AUDIT_DEL: | |
18900909 EP |
611 | return -EOPNOTSUPP; |
612 | case AUDIT_GET: | |
613 | case AUDIT_SET: | |
b0fed402 EP |
614 | case AUDIT_GET_FEATURE: |
615 | case AUDIT_SET_FEATURE: | |
18900909 EP |
616 | case AUDIT_LIST_RULES: |
617 | case AUDIT_ADD_RULE: | |
93315ed6 | 618 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 619 | case AUDIT_SIGNAL_INFO: |
522ed776 MT |
620 | case AUDIT_TTY_GET: |
621 | case AUDIT_TTY_SET: | |
74c3cbe3 AV |
622 | case AUDIT_TRIM: |
623 | case AUDIT_MAKE_EQUIV: | |
fd778461 | 624 | if (!capable(CAP_AUDIT_CONTROL)) |
1da177e4 LT |
625 | err = -EPERM; |
626 | break; | |
05474106 | 627 | case AUDIT_USER: |
039b6b3e RD |
628 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
629 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
fd778461 | 630 | if (!capable(CAP_AUDIT_WRITE)) |
1da177e4 LT |
631 | err = -EPERM; |
632 | break; | |
633 | default: /* bad msg */ | |
634 | err = -EINVAL; | |
635 | } | |
636 | ||
637 | return err; | |
638 | } | |
639 | ||
dc9eb698 | 640 | static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) |
50397bd1 EP |
641 | { |
642 | int rc = 0; | |
dc9eb698 | 643 | uid_t uid = from_kuid(&init_user_ns, current_uid()); |
50397bd1 | 644 | |
0868a5e1 | 645 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) { |
50397bd1 EP |
646 | *ab = NULL; |
647 | return rc; | |
648 | } | |
649 | ||
650 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); | |
0644ec0c KC |
651 | if (unlikely(!*ab)) |
652 | return rc; | |
4d3fb709 EP |
653 | audit_log_format(*ab, "pid=%d uid=%u", task_tgid_vnr(current), uid); |
654 | audit_log_session_info(*ab); | |
b122c376 | 655 | audit_log_task_context(*ab); |
50397bd1 EP |
656 | |
657 | return rc; | |
658 | } | |
659 | ||
b0fed402 EP |
660 | int is_audit_feature_set(int i) |
661 | { | |
662 | return af.features & AUDIT_FEATURE_TO_MASK(i); | |
663 | } | |
664 | ||
665 | ||
666 | static int audit_get_feature(struct sk_buff *skb) | |
667 | { | |
668 | u32 seq; | |
669 | ||
670 | seq = nlmsg_hdr(skb)->nlmsg_seq; | |
671 | ||
672 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, | |
673 | &af, sizeof(af)); | |
674 | ||
675 | return 0; | |
676 | } | |
677 | ||
678 | static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature, | |
679 | u32 old_lock, u32 new_lock, int res) | |
680 | { | |
681 | struct audit_buffer *ab; | |
682 | ||
b6c50fe0 G |
683 | if (audit_enabled == AUDIT_OFF) |
684 | return; | |
685 | ||
b0fed402 | 686 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE); |
aabce351 | 687 | audit_log_format(ab, "feature=%s old=%d new=%d old_lock=%d new_lock=%d res=%d", |
b0fed402 EP |
688 | audit_feature_names[which], !!old_feature, !!new_feature, |
689 | !!old_lock, !!new_lock, res); | |
690 | audit_log_end(ab); | |
691 | } | |
692 | ||
693 | static int audit_set_feature(struct sk_buff *skb) | |
694 | { | |
695 | struct audit_features *uaf; | |
696 | int i; | |
697 | ||
698 | BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > sizeof(audit_feature_names)/sizeof(audit_feature_names[0])); | |
699 | uaf = nlmsg_data(nlmsg_hdr(skb)); | |
700 | ||
701 | /* if there is ever a version 2 we should handle that here */ | |
702 | ||
703 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
704 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
705 | u32 old_feature, new_feature, old_lock, new_lock; | |
706 | ||
707 | /* if we are not changing this feature, move along */ | |
708 | if (!(feature & uaf->mask)) | |
709 | continue; | |
710 | ||
711 | old_feature = af.features & feature; | |
712 | new_feature = uaf->features & feature; | |
713 | new_lock = (uaf->lock | af.lock) & feature; | |
714 | old_lock = af.lock & feature; | |
715 | ||
716 | /* are we changing a locked feature? */ | |
717 | if ((af.lock & feature) && (new_feature != old_feature)) { | |
718 | audit_log_feature_change(i, old_feature, new_feature, | |
719 | old_lock, new_lock, 0); | |
720 | return -EPERM; | |
721 | } | |
722 | } | |
723 | /* nothing invalid, do the changes */ | |
724 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
725 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
726 | u32 old_feature, new_feature, old_lock, new_lock; | |
727 | ||
728 | /* if we are not changing this feature, move along */ | |
729 | if (!(feature & uaf->mask)) | |
730 | continue; | |
731 | ||
732 | old_feature = af.features & feature; | |
733 | new_feature = uaf->features & feature; | |
734 | old_lock = af.lock & feature; | |
735 | new_lock = (uaf->lock | af.lock) & feature; | |
736 | ||
737 | if (new_feature != old_feature) | |
738 | audit_log_feature_change(i, old_feature, new_feature, | |
739 | old_lock, new_lock, 1); | |
740 | ||
741 | if (new_feature) | |
742 | af.features |= feature; | |
743 | else | |
744 | af.features &= ~feature; | |
745 | af.lock |= new_lock; | |
746 | } | |
747 | ||
748 | return 0; | |
749 | } | |
750 | ||
1da177e4 LT |
751 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
752 | { | |
dc9eb698 | 753 | u32 seq; |
1da177e4 | 754 | void *data; |
1da177e4 | 755 | int err; |
c0404993 | 756 | struct audit_buffer *ab; |
1da177e4 | 757 | u16 msg_type = nlh->nlmsg_type; |
e1396065 | 758 | struct audit_sig_info *sig_data; |
50397bd1 | 759 | char *ctx = NULL; |
e1396065 | 760 | u32 len; |
1da177e4 | 761 | |
c7bdb545 | 762 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
763 | if (err) |
764 | return err; | |
765 | ||
b0dd25a8 RD |
766 | /* As soon as there's any sign of userspace auditd, |
767 | * start kauditd to talk to it */ | |
13f51e1c | 768 | if (!kauditd_task) { |
b7d11258 | 769 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
13f51e1c G |
770 | if (IS_ERR(kauditd_task)) { |
771 | err = PTR_ERR(kauditd_task); | |
772 | kauditd_task = NULL; | |
773 | return err; | |
774 | } | |
b7d11258 | 775 | } |
1da177e4 | 776 | seq = nlh->nlmsg_seq; |
c64e66c6 | 777 | data = nlmsg_data(nlh); |
1da177e4 LT |
778 | |
779 | switch (msg_type) { | |
09f883a9 RGB |
780 | case AUDIT_GET: { |
781 | struct audit_status s; | |
782 | memset(&s, 0, sizeof(s)); | |
783 | s.enabled = audit_enabled; | |
784 | s.failure = audit_failure; | |
785 | s.pid = audit_pid; | |
786 | s.rate_limit = audit_rate_limit; | |
787 | s.backlog_limit = audit_backlog_limit; | |
788 | s.lost = atomic_read(&audit_lost); | |
789 | s.backlog = skb_queue_len(&audit_skb_queue); | |
51cc83f0 RGB |
790 | s.version = 2; |
791 | s.backlog_wait_time = audit_backlog_wait_time; | |
15e47304 | 792 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, |
09f883a9 | 793 | &s, sizeof(s)); |
1da177e4 | 794 | break; |
09f883a9 RGB |
795 | } |
796 | case AUDIT_SET: { | |
797 | struct audit_status s; | |
798 | memset(&s, 0, sizeof(s)); | |
799 | /* guard against past and future API changes */ | |
800 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); | |
801 | if (s.mask & AUDIT_STATUS_ENABLED) { | |
802 | err = audit_set_enabled(s.enabled); | |
20c6aaa3 | 803 | if (err < 0) |
804 | return err; | |
1da177e4 | 805 | } |
09f883a9 RGB |
806 | if (s.mask & AUDIT_STATUS_FAILURE) { |
807 | err = audit_set_failure(s.failure); | |
20c6aaa3 | 808 | if (err < 0) |
809 | return err; | |
1da177e4 | 810 | } |
09f883a9 RGB |
811 | if (s.mask & AUDIT_STATUS_PID) { |
812 | int new_pid = s.pid; | |
1a6b9f23 EP |
813 | |
814 | if (audit_enabled != AUDIT_OFF) | |
dc9eb698 | 815 | audit_log_config_change("audit_pid", new_pid, audit_pid, 1); |
1a6b9f23 | 816 | audit_pid = new_pid; |
15e47304 | 817 | audit_nlk_portid = NETLINK_CB(skb).portid; |
33faba7f | 818 | audit_sock = NETLINK_CB(skb).sk; |
1da177e4 | 819 | } |
09f883a9 RGB |
820 | if (s.mask & AUDIT_STATUS_RATE_LIMIT) { |
821 | err = audit_set_rate_limit(s.rate_limit); | |
20c6aaa3 | 822 | if (err < 0) |
823 | return err; | |
824 | } | |
51cc83f0 | 825 | if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) { |
09f883a9 | 826 | err = audit_set_backlog_limit(s.backlog_limit); |
51cc83f0 RGB |
827 | if (err < 0) |
828 | return err; | |
829 | } | |
830 | switch (s.version) { | |
831 | /* add future vers # cases immediately below and allow | |
832 | * to fall through */ | |
833 | case 2: | |
834 | if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) { | |
835 | if (sizeof(s) > (size_t)nlh->nlmsg_len) | |
836 | return -EINVAL; | |
837 | if (s.backlog_wait_time < 0 || | |
838 | s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME) | |
839 | return -EINVAL; | |
840 | err = audit_set_backlog_wait_time(s.backlog_wait_time); | |
841 | if (err < 0) | |
842 | return err; | |
843 | } | |
844 | default: | |
845 | break; | |
846 | } | |
1da177e4 | 847 | break; |
09f883a9 | 848 | } |
b0fed402 EP |
849 | case AUDIT_GET_FEATURE: |
850 | err = audit_get_feature(skb); | |
851 | if (err) | |
852 | return err; | |
853 | break; | |
854 | case AUDIT_SET_FEATURE: | |
855 | err = audit_set_feature(skb); | |
856 | if (err) | |
857 | return err; | |
858 | break; | |
05474106 | 859 | case AUDIT_USER: |
039b6b3e RD |
860 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
861 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
862 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
863 | return 0; | |
864 | ||
62062cf8 | 865 | err = audit_filter_user(msg_type); |
4a4cd633 DW |
866 | if (err == 1) { |
867 | err = 0; | |
522ed776 | 868 | if (msg_type == AUDIT_USER_TTY) { |
152f497b | 869 | err = tty_audit_push_current(); |
522ed776 MT |
870 | if (err) |
871 | break; | |
872 | } | |
dc9eb698 | 873 | audit_log_common_recv_msg(&ab, msg_type); |
50397bd1 | 874 | if (msg_type != AUDIT_USER_TTY) |
b50eba7e RGB |
875 | audit_log_format(ab, " msg='%.*s'", |
876 | AUDIT_MESSAGE_TEXT_MAX, | |
50397bd1 EP |
877 | (char *)data); |
878 | else { | |
879 | int size; | |
880 | ||
f7616102 | 881 | audit_log_format(ab, " data="); |
50397bd1 | 882 | size = nlmsg_len(nlh); |
55ad2f8d MT |
883 | if (size > 0 && |
884 | ((unsigned char *)data)[size - 1] == '\0') | |
885 | size--; | |
b556f8ad | 886 | audit_log_n_untrustedstring(ab, data, size); |
4a4cd633 | 887 | } |
f9441639 | 888 | audit_set_portid(ab, NETLINK_CB(skb).portid); |
50397bd1 | 889 | audit_log_end(ab); |
0f45aa18 | 890 | } |
1da177e4 | 891 | break; |
93315ed6 AG |
892 | case AUDIT_ADD_RULE: |
893 | case AUDIT_DEL_RULE: | |
894 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
895 | return -EINVAL; | |
1a6b9f23 | 896 | if (audit_enabled == AUDIT_LOCKED) { |
dc9eb698 EP |
897 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
898 | audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); | |
50397bd1 | 899 | audit_log_end(ab); |
6a01b07f SG |
900 | return -EPERM; |
901 | } | |
93315ed6 AG |
902 | /* fallthrough */ |
903 | case AUDIT_LIST_RULES: | |
15e47304 | 904 | err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid, |
dc9eb698 | 905 | seq, data, nlmsg_len(nlh)); |
1da177e4 | 906 | break; |
74c3cbe3 AV |
907 | case AUDIT_TRIM: |
908 | audit_trim_trees(); | |
dc9eb698 | 909 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
74c3cbe3 AV |
910 | audit_log_format(ab, " op=trim res=1"); |
911 | audit_log_end(ab); | |
912 | break; | |
913 | case AUDIT_MAKE_EQUIV: { | |
914 | void *bufp = data; | |
915 | u32 sizes[2]; | |
7719e437 | 916 | size_t msglen = nlmsg_len(nlh); |
74c3cbe3 AV |
917 | char *old, *new; |
918 | ||
919 | err = -EINVAL; | |
7719e437 | 920 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
921 | break; |
922 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
923 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
924 | msglen -= 2 * sizeof(u32); |
925 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
926 | if (IS_ERR(old)) { |
927 | err = PTR_ERR(old); | |
928 | break; | |
929 | } | |
7719e437 | 930 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
931 | if (IS_ERR(new)) { |
932 | err = PTR_ERR(new); | |
933 | kfree(old); | |
934 | break; | |
935 | } | |
936 | /* OK, here comes... */ | |
937 | err = audit_tag_tree(old, new); | |
938 | ||
dc9eb698 | 939 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
50397bd1 | 940 | |
74c3cbe3 AV |
941 | audit_log_format(ab, " op=make_equiv old="); |
942 | audit_log_untrustedstring(ab, old); | |
943 | audit_log_format(ab, " new="); | |
944 | audit_log_untrustedstring(ab, new); | |
945 | audit_log_format(ab, " res=%d", !err); | |
946 | audit_log_end(ab); | |
947 | kfree(old); | |
948 | kfree(new); | |
949 | break; | |
950 | } | |
c2f0c7c3 | 951 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
952 | len = 0; |
953 | if (audit_sig_sid) { | |
954 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
955 | if (err) | |
956 | return err; | |
957 | } | |
e1396065 AV |
958 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
959 | if (!sig_data) { | |
939cbf26 EP |
960 | if (audit_sig_sid) |
961 | security_release_secctx(ctx, len); | |
e1396065 AV |
962 | return -ENOMEM; |
963 | } | |
cca080d9 | 964 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
e1396065 | 965 | sig_data->pid = audit_sig_pid; |
939cbf26 EP |
966 | if (audit_sig_sid) { |
967 | memcpy(sig_data->ctx, ctx, len); | |
968 | security_release_secctx(ctx, len); | |
969 | } | |
15e47304 | 970 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO, |
e1396065 AV |
971 | 0, 0, sig_data, sizeof(*sig_data) + len); |
972 | kfree(sig_data); | |
c2f0c7c3 | 973 | break; |
522ed776 MT |
974 | case AUDIT_TTY_GET: { |
975 | struct audit_tty_status s; | |
8aa14b64 EB |
976 | struct task_struct *tsk = current; |
977 | ||
7173c54e | 978 | spin_lock(&tsk->sighand->siglock); |
b95d77fe | 979 | s.enabled = tsk->signal->audit_tty; |
46e959ea | 980 | s.log_passwd = tsk->signal->audit_tty_log_passwd; |
7173c54e | 981 | spin_unlock(&tsk->sighand->siglock); |
8aa14b64 | 982 | |
aecdc33e | 983 | audit_send_reply(NETLINK_CB(skb).portid, seq, |
8aa14b64 | 984 | AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
522ed776 MT |
985 | break; |
986 | } | |
987 | case AUDIT_TTY_SET: { | |
46e959ea | 988 | struct audit_tty_status s; |
8aa14b64 | 989 | struct task_struct *tsk = current; |
522ed776 | 990 | |
46e959ea RGB |
991 | memset(&s, 0, sizeof(s)); |
992 | /* guard against past and future API changes */ | |
4d8fe737 | 993 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); |
46e959ea RGB |
994 | if ((s.enabled != 0 && s.enabled != 1) || |
995 | (s.log_passwd != 0 && s.log_passwd != 1)) | |
522ed776 | 996 | return -EINVAL; |
8aa14b64 | 997 | |
7173c54e | 998 | spin_lock(&tsk->sighand->siglock); |
46e959ea RGB |
999 | tsk->signal->audit_tty = s.enabled; |
1000 | tsk->signal->audit_tty_log_passwd = s.log_passwd; | |
7173c54e | 1001 | spin_unlock(&tsk->sighand->siglock); |
522ed776 MT |
1002 | break; |
1003 | } | |
1da177e4 LT |
1004 | default: |
1005 | err = -EINVAL; | |
1006 | break; | |
1007 | } | |
1008 | ||
1009 | return err < 0 ? err : 0; | |
1010 | } | |
1011 | ||
b0dd25a8 | 1012 | /* |
ea7ae60b EP |
1013 | * Get message from skb. Each message is processed by audit_receive_msg. |
1014 | * Malformed skbs with wrong length are discarded silently. | |
b0dd25a8 | 1015 | */ |
2a0a6ebe | 1016 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 | 1017 | { |
ea7ae60b EP |
1018 | struct nlmsghdr *nlh; |
1019 | /* | |
94191213 | 1020 | * len MUST be signed for nlmsg_next to be able to dec it below 0 |
ea7ae60b EP |
1021 | * if the nlmsg_len was not aligned |
1022 | */ | |
1023 | int len; | |
1024 | int err; | |
1025 | ||
1026 | nlh = nlmsg_hdr(skb); | |
1027 | len = skb->len; | |
1028 | ||
94191213 | 1029 | while (nlmsg_ok(nlh, len)) { |
ea7ae60b EP |
1030 | err = audit_receive_msg(skb, nlh); |
1031 | /* if err or if this message says it wants a response */ | |
1032 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
1da177e4 | 1033 | netlink_ack(skb, nlh, err); |
ea7ae60b | 1034 | |
2851da57 | 1035 | nlh = nlmsg_next(nlh, &len); |
1da177e4 | 1036 | } |
1da177e4 LT |
1037 | } |
1038 | ||
1039 | /* Receive messages from netlink socket. */ | |
cd40b7d3 | 1040 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 1041 | { |
f368c07d | 1042 | mutex_lock(&audit_cmd_mutex); |
cd40b7d3 | 1043 | audit_receive_skb(skb); |
f368c07d | 1044 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
1045 | } |
1046 | ||
33faba7f | 1047 | static int __net_init audit_net_init(struct net *net) |
1da177e4 | 1048 | { |
a31f2d17 PNA |
1049 | struct netlink_kernel_cfg cfg = { |
1050 | .input = audit_receive, | |
1051 | }; | |
f368c07d | 1052 | |
33faba7f RGB |
1053 | struct audit_net *aunet = net_generic(net, audit_net_id); |
1054 | ||
1055 | pr_info("audit: initializing netlink socket in namespace\n"); | |
1056 | ||
1057 | aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg); | |
1058 | if (aunet->nlsk == NULL) | |
1059 | return -ENOMEM; | |
1060 | if (!aunet->nlsk) | |
1061 | audit_panic("cannot initialize netlink socket in namespace"); | |
1062 | else | |
1063 | aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; | |
1064 | return 0; | |
1065 | } | |
1066 | ||
1067 | static void __net_exit audit_net_exit(struct net *net) | |
1068 | { | |
1069 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
1070 | struct sock *sock = aunet->nlsk; | |
1071 | if (sock == audit_sock) { | |
1072 | audit_pid = 0; | |
1073 | audit_sock = NULL; | |
1074 | } | |
1075 | ||
1076 | rcu_assign_pointer(aunet->nlsk, NULL); | |
1077 | synchronize_net(); | |
1078 | netlink_kernel_release(sock); | |
1079 | } | |
1080 | ||
1081 | static struct pernet_operations __net_initdata audit_net_ops = { | |
1082 | .init = audit_net_init, | |
1083 | .exit = audit_net_exit, | |
1084 | .id = &audit_net_id, | |
1085 | .size = sizeof(struct audit_net), | |
1086 | }; | |
1087 | ||
1088 | /* Initialize audit support at boot time. */ | |
1089 | static int __init audit_init(void) | |
1090 | { | |
1091 | int i; | |
1092 | ||
a3f07114 EP |
1093 | if (audit_initialized == AUDIT_DISABLED) |
1094 | return 0; | |
1095 | ||
33faba7f | 1096 | pr_info("audit: initializing netlink subsys (%s)\n", |
1da177e4 | 1097 | audit_default ? "enabled" : "disabled"); |
33faba7f | 1098 | register_pernet_subsys(&audit_net_ops); |
1da177e4 | 1099 | |
b7d11258 | 1100 | skb_queue_head_init(&audit_skb_queue); |
f3d357b0 | 1101 | skb_queue_head_init(&audit_skb_hold_queue); |
a3f07114 | 1102 | audit_initialized = AUDIT_INITIALIZED; |
1da177e4 | 1103 | audit_enabled = audit_default; |
b593d384 | 1104 | audit_ever_enabled |= !!audit_default; |
3dc7e315 | 1105 | |
9ad9ad38 | 1106 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
f368c07d | 1107 | |
f368c07d AG |
1108 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
1109 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 1110 | |
1da177e4 LT |
1111 | return 0; |
1112 | } | |
1da177e4 LT |
1113 | __initcall(audit_init); |
1114 | ||
1115 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
1116 | static int __init audit_enable(char *str) | |
1117 | { | |
1118 | audit_default = !!simple_strtol(str, NULL, 0); | |
a3f07114 EP |
1119 | if (!audit_default) |
1120 | audit_initialized = AUDIT_DISABLED; | |
1121 | ||
d3ca0344 G |
1122 | pr_info("audit: %s\n", audit_default ? |
1123 | "enabled (after initialization)" : "disabled (until reboot)"); | |
a3f07114 | 1124 | |
9b41046c | 1125 | return 1; |
1da177e4 | 1126 | } |
1da177e4 LT |
1127 | __setup("audit=", audit_enable); |
1128 | ||
f910fde7 RGB |
1129 | /* Process kernel command-line parameter at boot time. |
1130 | * audit_backlog_limit=<n> */ | |
1131 | static int __init audit_backlog_limit_set(char *str) | |
1132 | { | |
1133 | long int audit_backlog_limit_arg; | |
1134 | pr_info("audit_backlog_limit: "); | |
1135 | if (kstrtol(str, 0, &audit_backlog_limit_arg)) { | |
1136 | printk("using default of %d, unable to parse %s\n", | |
1137 | audit_backlog_limit, str); | |
1138 | return 1; | |
1139 | } | |
1140 | if (audit_backlog_limit_arg >= 0) | |
1141 | audit_backlog_limit = (int)audit_backlog_limit_arg; | |
1142 | printk("%d\n", audit_backlog_limit); | |
1143 | ||
1144 | return 1; | |
1145 | } | |
1146 | __setup("audit_backlog_limit=", audit_backlog_limit_set); | |
1147 | ||
16e1904e CW |
1148 | static void audit_buffer_free(struct audit_buffer *ab) |
1149 | { | |
1150 | unsigned long flags; | |
1151 | ||
8fc6115c CW |
1152 | if (!ab) |
1153 | return; | |
1154 | ||
5ac52f33 CW |
1155 | if (ab->skb) |
1156 | kfree_skb(ab->skb); | |
b7d11258 | 1157 | |
16e1904e | 1158 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 1159 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 1160 | kfree(ab); |
5d136a01 SH |
1161 | else { |
1162 | audit_freelist_count++; | |
16e1904e | 1163 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 1164 | } |
16e1904e CW |
1165 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
1166 | } | |
1167 | ||
c0404993 | 1168 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 1169 | gfp_t gfp_mask, int type) |
16e1904e CW |
1170 | { |
1171 | unsigned long flags; | |
1172 | struct audit_buffer *ab = NULL; | |
c0404993 | 1173 | struct nlmsghdr *nlh; |
16e1904e CW |
1174 | |
1175 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
1176 | if (!list_empty(&audit_freelist)) { | |
1177 | ab = list_entry(audit_freelist.next, | |
1178 | struct audit_buffer, list); | |
1179 | list_del(&ab->list); | |
1180 | --audit_freelist_count; | |
1181 | } | |
1182 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
1183 | ||
1184 | if (!ab) { | |
4332bdd3 | 1185 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 1186 | if (!ab) |
8fc6115c | 1187 | goto err; |
16e1904e | 1188 | } |
8fc6115c | 1189 | |
b7d11258 | 1190 | ab->ctx = ctx; |
9ad9ad38 | 1191 | ab->gfp_mask = gfp_mask; |
ee080e6c EP |
1192 | |
1193 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1194 | if (!ab->skb) | |
c64e66c6 | 1195 | goto err; |
ee080e6c | 1196 | |
c64e66c6 DM |
1197 | nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); |
1198 | if (!nlh) | |
1199 | goto out_kfree_skb; | |
ee080e6c | 1200 | |
16e1904e | 1201 | return ab; |
ee080e6c | 1202 | |
c64e66c6 | 1203 | out_kfree_skb: |
ee080e6c EP |
1204 | kfree_skb(ab->skb); |
1205 | ab->skb = NULL; | |
8fc6115c CW |
1206 | err: |
1207 | audit_buffer_free(ab); | |
1208 | return NULL; | |
16e1904e | 1209 | } |
1da177e4 | 1210 | |
b0dd25a8 RD |
1211 | /** |
1212 | * audit_serial - compute a serial number for the audit record | |
1213 | * | |
1214 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1215 | * written to user-space as soon as they are generated, so a complete |
1216 | * audit record may be written in several pieces. The timestamp of the | |
1217 | * record and this serial number are used by the user-space tools to | |
1218 | * determine which pieces belong to the same audit record. The | |
1219 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1220 | * syscall entry to syscall exit. | |
1221 | * | |
bfb4496e DW |
1222 | * NOTE: Another possibility is to store the formatted records off the |
1223 | * audit context (for those records that have a context), and emit them | |
1224 | * all at syscall exit. However, this could delay the reporting of | |
1225 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1226 | * halts). |
1227 | */ | |
bfb4496e DW |
1228 | unsigned int audit_serial(void) |
1229 | { | |
34af946a | 1230 | static DEFINE_SPINLOCK(serial_lock); |
d5b454f2 DW |
1231 | static unsigned int serial = 0; |
1232 | ||
1233 | unsigned long flags; | |
1234 | unsigned int ret; | |
bfb4496e | 1235 | |
d5b454f2 | 1236 | spin_lock_irqsave(&serial_lock, flags); |
bfb4496e | 1237 | do { |
ce625a80 DW |
1238 | ret = ++serial; |
1239 | } while (unlikely(!ret)); | |
d5b454f2 | 1240 | spin_unlock_irqrestore(&serial_lock, flags); |
bfb4496e | 1241 | |
d5b454f2 | 1242 | return ret; |
bfb4496e DW |
1243 | } |
1244 | ||
5600b892 | 1245 | static inline void audit_get_stamp(struct audit_context *ctx, |
bfb4496e DW |
1246 | struct timespec *t, unsigned int *serial) |
1247 | { | |
48887e63 | 1248 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
bfb4496e DW |
1249 | *t = CURRENT_TIME; |
1250 | *serial = audit_serial(); | |
1251 | } | |
1252 | } | |
1253 | ||
82919919 AM |
1254 | /* |
1255 | * Wait for auditd to drain the queue a little | |
1256 | */ | |
ae887e0b | 1257 | static unsigned long wait_for_auditd(unsigned long sleep_time) |
82919919 | 1258 | { |
ae887e0b | 1259 | unsigned long timeout = sleep_time; |
82919919 | 1260 | DECLARE_WAITQUEUE(wait, current); |
f000cfdd | 1261 | set_current_state(TASK_UNINTERRUPTIBLE); |
7ecf69bf | 1262 | add_wait_queue_exclusive(&audit_backlog_wait, &wait); |
82919919 AM |
1263 | |
1264 | if (audit_backlog_limit && | |
1265 | skb_queue_len(&audit_skb_queue) > audit_backlog_limit) | |
ae887e0b | 1266 | timeout = schedule_timeout(sleep_time); |
82919919 AM |
1267 | |
1268 | __set_current_state(TASK_RUNNING); | |
1269 | remove_wait_queue(&audit_backlog_wait, &wait); | |
ae887e0b RGB |
1270 | |
1271 | return timeout; | |
82919919 AM |
1272 | } |
1273 | ||
b0dd25a8 RD |
1274 | /** |
1275 | * audit_log_start - obtain an audit buffer | |
1276 | * @ctx: audit_context (may be NULL) | |
1277 | * @gfp_mask: type of allocation | |
1278 | * @type: audit message type | |
1279 | * | |
1280 | * Returns audit_buffer pointer on success or NULL on error. | |
1281 | * | |
1282 | * Obtain an audit buffer. This routine does locking to obtain the | |
1283 | * audit buffer, but then no locking is required for calls to | |
1284 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1285 | * syscall, then the syscall is marked as auditable and an audit record | |
1286 | * will be written at syscall exit. If there is no associated task, then | |
1287 | * task context (ctx) should be NULL. | |
1288 | */ | |
9796fdd8 | 1289 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1290 | int type) |
1da177e4 LT |
1291 | { |
1292 | struct audit_buffer *ab = NULL; | |
1da177e4 | 1293 | struct timespec t; |
ef00be05 | 1294 | unsigned int uninitialized_var(serial); |
9ad9ad38 | 1295 | int reserve; |
ac4cec44 | 1296 | unsigned long timeout_start = jiffies; |
1da177e4 | 1297 | |
a3f07114 | 1298 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1299 | return NULL; |
1300 | ||
c8edc80c DK |
1301 | if (unlikely(audit_filter_type(type))) |
1302 | return NULL; | |
1303 | ||
9ad9ad38 DW |
1304 | if (gfp_mask & __GFP_WAIT) |
1305 | reserve = 0; | |
1306 | else | |
5600b892 | 1307 | reserve = 5; /* Allow atomic callers to go up to five |
9ad9ad38 DW |
1308 | entries over the normal backlog limit */ |
1309 | ||
1310 | while (audit_backlog_limit | |
1311 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { | |
82919919 AM |
1312 | if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) { |
1313 | unsigned long sleep_time; | |
9ad9ad38 | 1314 | |
82919919 AM |
1315 | sleep_time = timeout_start + audit_backlog_wait_time - |
1316 | jiffies; | |
8ac1c8d5 | 1317 | if ((long)sleep_time > 0) { |
ae887e0b RGB |
1318 | sleep_time = wait_for_auditd(sleep_time); |
1319 | if ((long)sleep_time > 0) | |
1320 | continue; | |
8ac1c8d5 | 1321 | } |
9ad9ad38 | 1322 | } |
320f1b1e | 1323 | if (audit_rate_check() && printk_ratelimit()) |
fb19b4c6 DW |
1324 | printk(KERN_WARNING |
1325 | "audit: audit_backlog=%d > " | |
1326 | "audit_backlog_limit=%d\n", | |
1327 | skb_queue_len(&audit_skb_queue), | |
1328 | audit_backlog_limit); | |
1329 | audit_log_lost("backlog limit exceeded"); | |
ac4cec44 DW |
1330 | audit_backlog_wait_time = audit_backlog_wait_overflow; |
1331 | wake_up(&audit_backlog_wait); | |
fb19b4c6 DW |
1332 | return NULL; |
1333 | } | |
1334 | ||
e789e561 RGB |
1335 | audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; |
1336 | ||
9ad9ad38 | 1337 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1338 | if (!ab) { |
1339 | audit_log_lost("out of memory in audit_log_start"); | |
1340 | return NULL; | |
1341 | } | |
1342 | ||
bfb4496e | 1343 | audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6 | 1344 | |
1da177e4 LT |
1345 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
1346 | t.tv_sec, t.tv_nsec/1000000, serial); | |
1347 | return ab; | |
1348 | } | |
1349 | ||
8fc6115c | 1350 | /** |
5ac52f33 | 1351 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1352 | * @ab: audit_buffer |
b0dd25a8 | 1353 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1354 | * |
1355 | * Returns 0 (no space) on failed expansion, or available space if | |
1356 | * successful. | |
1357 | */ | |
e3b926b4 | 1358 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1359 | { |
5ac52f33 | 1360 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1361 | int oldtail = skb_tailroom(skb); |
1362 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1363 | int newtail = skb_tailroom(skb); | |
1364 | ||
5ac52f33 CW |
1365 | if (ret < 0) { |
1366 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1367 | return 0; |
5ac52f33 | 1368 | } |
406a1d86 HX |
1369 | |
1370 | skb->truesize += newtail - oldtail; | |
1371 | return newtail; | |
8fc6115c | 1372 | } |
1da177e4 | 1373 | |
b0dd25a8 RD |
1374 | /* |
1375 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1376 | * room in the audit buffer, more room will be allocated and vsnprint |
1377 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1378 | * can't format message larger than 1024 bytes, so we don't either. |
1379 | */ | |
1da177e4 LT |
1380 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1381 | va_list args) | |
1382 | { | |
1383 | int len, avail; | |
5ac52f33 | 1384 | struct sk_buff *skb; |
eecb0a73 | 1385 | va_list args2; |
1da177e4 LT |
1386 | |
1387 | if (!ab) | |
1388 | return; | |
1389 | ||
5ac52f33 CW |
1390 | BUG_ON(!ab->skb); |
1391 | skb = ab->skb; | |
1392 | avail = skb_tailroom(skb); | |
1393 | if (avail == 0) { | |
e3b926b4 | 1394 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1395 | if (!avail) |
1396 | goto out; | |
1da177e4 | 1397 | } |
eecb0a73 | 1398 | va_copy(args2, args); |
27a884dc | 1399 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1400 | if (len >= avail) { |
1401 | /* The printk buffer is 1024 bytes long, so if we get | |
1402 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1403 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1404 | avail = audit_expand(ab, |
1405 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1406 | if (!avail) |
a0e86bd4 | 1407 | goto out_va_end; |
27a884dc | 1408 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1409 | } |
168b7173 SG |
1410 | if (len > 0) |
1411 | skb_put(skb, len); | |
a0e86bd4 JJ |
1412 | out_va_end: |
1413 | va_end(args2); | |
8fc6115c CW |
1414 | out: |
1415 | return; | |
1da177e4 LT |
1416 | } |
1417 | ||
b0dd25a8 RD |
1418 | /** |
1419 | * audit_log_format - format a message into the audit buffer. | |
1420 | * @ab: audit_buffer | |
1421 | * @fmt: format string | |
1422 | * @...: optional parameters matching @fmt string | |
1423 | * | |
1424 | * All the work is done in audit_log_vformat. | |
1425 | */ | |
1da177e4 LT |
1426 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1427 | { | |
1428 | va_list args; | |
1429 | ||
1430 | if (!ab) | |
1431 | return; | |
1432 | va_start(args, fmt); | |
1433 | audit_log_vformat(ab, fmt, args); | |
1434 | va_end(args); | |
1435 | } | |
1436 | ||
b0dd25a8 RD |
1437 | /** |
1438 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
1439 | * @ab: the audit_buffer | |
1440 | * @buf: buffer to convert to hex | |
1441 | * @len: length of @buf to be converted | |
1442 | * | |
1443 | * No return value; failure to expand is silently ignored. | |
1444 | * | |
1445 | * This function will take the passed buf and convert it into a string of | |
1446 | * ascii hex digits. The new string is placed onto the skb. | |
1447 | */ | |
b556f8ad | 1448 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1449 | size_t len) |
83c7d091 | 1450 | { |
168b7173 SG |
1451 | int i, avail, new_len; |
1452 | unsigned char *ptr; | |
1453 | struct sk_buff *skb; | |
1454 | static const unsigned char *hex = "0123456789ABCDEF"; | |
1455 | ||
8ef2d304 AG |
1456 | if (!ab) |
1457 | return; | |
1458 | ||
168b7173 SG |
1459 | BUG_ON(!ab->skb); |
1460 | skb = ab->skb; | |
1461 | avail = skb_tailroom(skb); | |
1462 | new_len = len<<1; | |
1463 | if (new_len >= avail) { | |
1464 | /* Round the buffer request up to the next multiple */ | |
1465 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1466 | avail = audit_expand(ab, new_len); | |
1467 | if (!avail) | |
1468 | return; | |
1469 | } | |
83c7d091 | 1470 | |
27a884dc | 1471 | ptr = skb_tail_pointer(skb); |
168b7173 SG |
1472 | for (i=0; i<len; i++) { |
1473 | *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ | |
1474 | *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ | |
1475 | } | |
1476 | *ptr = 0; | |
1477 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 DW |
1478 | } |
1479 | ||
9c937dcc AG |
1480 | /* |
1481 | * Format a string of no more than slen characters into the audit buffer, | |
1482 | * enclosed in quote marks. | |
1483 | */ | |
b556f8ad EP |
1484 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1485 | size_t slen) | |
9c937dcc AG |
1486 | { |
1487 | int avail, new_len; | |
1488 | unsigned char *ptr; | |
1489 | struct sk_buff *skb; | |
1490 | ||
8ef2d304 AG |
1491 | if (!ab) |
1492 | return; | |
1493 | ||
9c937dcc AG |
1494 | BUG_ON(!ab->skb); |
1495 | skb = ab->skb; | |
1496 | avail = skb_tailroom(skb); | |
1497 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1498 | if (new_len > avail) { | |
1499 | avail = audit_expand(ab, new_len); | |
1500 | if (!avail) | |
1501 | return; | |
1502 | } | |
27a884dc | 1503 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1504 | *ptr++ = '"'; |
1505 | memcpy(ptr, string, slen); | |
1506 | ptr += slen; | |
1507 | *ptr++ = '"'; | |
1508 | *ptr = 0; | |
1509 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1510 | } | |
1511 | ||
de6bbd1d EP |
1512 | /** |
1513 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1514 | * @string: string to be checked |
1515 | * @len: max length of the string to check | |
de6bbd1d EP |
1516 | */ |
1517 | int audit_string_contains_control(const char *string, size_t len) | |
1518 | { | |
1519 | const unsigned char *p; | |
b3897f56 | 1520 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1521 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
de6bbd1d EP |
1522 | return 1; |
1523 | } | |
1524 | return 0; | |
1525 | } | |
1526 | ||
b0dd25a8 | 1527 | /** |
522ed776 | 1528 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1529 | * @ab: audit_buffer |
f706d5d2 | 1530 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1531 | * @string: string to be logged |
1532 | * | |
1533 | * This code will escape a string that is passed to it if the string | |
1534 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1535 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1536 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1537 | * |
1538 | * The caller specifies the number of characters in the string to log, which may | |
1539 | * or may not be the entire string. | |
b0dd25a8 | 1540 | */ |
b556f8ad EP |
1541 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
1542 | size_t len) | |
83c7d091 | 1543 | { |
de6bbd1d | 1544 | if (audit_string_contains_control(string, len)) |
b556f8ad | 1545 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 1546 | else |
b556f8ad | 1547 | audit_log_n_string(ab, string, len); |
83c7d091 DW |
1548 | } |
1549 | ||
9c937dcc | 1550 | /** |
522ed776 | 1551 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
1552 | * @ab: audit_buffer |
1553 | * @string: string to be logged | |
1554 | * | |
522ed776 | 1555 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
1556 | * determine string length. |
1557 | */ | |
de6bbd1d | 1558 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 1559 | { |
b556f8ad | 1560 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
1561 | } |
1562 | ||
168b7173 | 1563 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 1564 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 1565 | const struct path *path) |
1da177e4 | 1566 | { |
44707fdf | 1567 | char *p, *pathname; |
1da177e4 | 1568 | |
8fc6115c | 1569 | if (prefix) |
c158a35c | 1570 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 1571 | |
168b7173 | 1572 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
1573 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
1574 | if (!pathname) { | |
def57543 | 1575 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 1576 | return; |
1da177e4 | 1577 | } |
cf28b486 | 1578 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
1579 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
1580 | /* FIXME: can we save some information here? */ | |
def57543 | 1581 | audit_log_string(ab, "<too_long>"); |
5600b892 | 1582 | } else |
168b7173 | 1583 | audit_log_untrustedstring(ab, p); |
44707fdf | 1584 | kfree(pathname); |
1da177e4 LT |
1585 | } |
1586 | ||
4d3fb709 EP |
1587 | void audit_log_session_info(struct audit_buffer *ab) |
1588 | { | |
1589 | u32 sessionid = audit_get_sessionid(current); | |
1590 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); | |
1591 | ||
b8f89caa | 1592 | audit_log_format(ab, " auid=%u ses=%u", auid, sessionid); |
4d3fb709 EP |
1593 | } |
1594 | ||
9d960985 EP |
1595 | void audit_log_key(struct audit_buffer *ab, char *key) |
1596 | { | |
1597 | audit_log_format(ab, " key="); | |
1598 | if (key) | |
1599 | audit_log_untrustedstring(ab, key); | |
1600 | else | |
1601 | audit_log_format(ab, "(null)"); | |
1602 | } | |
1603 | ||
b24a30a7 EP |
1604 | void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) |
1605 | { | |
1606 | int i; | |
1607 | ||
1608 | audit_log_format(ab, " %s=", prefix); | |
1609 | CAP_FOR_EACH_U32(i) { | |
1610 | audit_log_format(ab, "%08x", | |
1611 | cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]); | |
1612 | } | |
1613 | } | |
1614 | ||
1615 | void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) | |
1616 | { | |
1617 | kernel_cap_t *perm = &name->fcap.permitted; | |
1618 | kernel_cap_t *inh = &name->fcap.inheritable; | |
1619 | int log = 0; | |
1620 | ||
1621 | if (!cap_isclear(*perm)) { | |
1622 | audit_log_cap(ab, "cap_fp", perm); | |
1623 | log = 1; | |
1624 | } | |
1625 | if (!cap_isclear(*inh)) { | |
1626 | audit_log_cap(ab, "cap_fi", inh); | |
1627 | log = 1; | |
1628 | } | |
1629 | ||
1630 | if (log) | |
1631 | audit_log_format(ab, " cap_fe=%d cap_fver=%x", | |
1632 | name->fcap.fE, name->fcap_ver); | |
1633 | } | |
1634 | ||
1635 | static inline int audit_copy_fcaps(struct audit_names *name, | |
1636 | const struct dentry *dentry) | |
1637 | { | |
1638 | struct cpu_vfs_cap_data caps; | |
1639 | int rc; | |
1640 | ||
1641 | if (!dentry) | |
1642 | return 0; | |
1643 | ||
1644 | rc = get_vfs_caps_from_disk(dentry, &caps); | |
1645 | if (rc) | |
1646 | return rc; | |
1647 | ||
1648 | name->fcap.permitted = caps.permitted; | |
1649 | name->fcap.inheritable = caps.inheritable; | |
1650 | name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); | |
1651 | name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> | |
1652 | VFS_CAP_REVISION_SHIFT; | |
1653 | ||
1654 | return 0; | |
1655 | } | |
1656 | ||
1657 | /* Copy inode data into an audit_names. */ | |
1658 | void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, | |
1659 | const struct inode *inode) | |
1660 | { | |
1661 | name->ino = inode->i_ino; | |
1662 | name->dev = inode->i_sb->s_dev; | |
1663 | name->mode = inode->i_mode; | |
1664 | name->uid = inode->i_uid; | |
1665 | name->gid = inode->i_gid; | |
1666 | name->rdev = inode->i_rdev; | |
1667 | security_inode_getsecid(inode, &name->osid); | |
1668 | audit_copy_fcaps(name, dentry); | |
1669 | } | |
1670 | ||
1671 | /** | |
1672 | * audit_log_name - produce AUDIT_PATH record from struct audit_names | |
1673 | * @context: audit_context for the task | |
1674 | * @n: audit_names structure with reportable details | |
1675 | * @path: optional path to report instead of audit_names->name | |
1676 | * @record_num: record number to report when handling a list of names | |
1677 | * @call_panic: optional pointer to int that will be updated if secid fails | |
1678 | */ | |
1679 | void audit_log_name(struct audit_context *context, struct audit_names *n, | |
1680 | struct path *path, int record_num, int *call_panic) | |
1681 | { | |
1682 | struct audit_buffer *ab; | |
1683 | ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); | |
1684 | if (!ab) | |
1685 | return; | |
1686 | ||
1687 | audit_log_format(ab, "item=%d", record_num); | |
1688 | ||
1689 | if (path) | |
1690 | audit_log_d_path(ab, " name=", path); | |
1691 | else if (n->name) { | |
1692 | switch (n->name_len) { | |
1693 | case AUDIT_NAME_FULL: | |
1694 | /* log the full path */ | |
1695 | audit_log_format(ab, " name="); | |
1696 | audit_log_untrustedstring(ab, n->name->name); | |
1697 | break; | |
1698 | case 0: | |
1699 | /* name was specified as a relative path and the | |
1700 | * directory component is the cwd */ | |
1701 | audit_log_d_path(ab, " name=", &context->pwd); | |
1702 | break; | |
1703 | default: | |
1704 | /* log the name's directory component */ | |
1705 | audit_log_format(ab, " name="); | |
1706 | audit_log_n_untrustedstring(ab, n->name->name, | |
1707 | n->name_len); | |
1708 | } | |
1709 | } else | |
1710 | audit_log_format(ab, " name=(null)"); | |
1711 | ||
1712 | if (n->ino != (unsigned long)-1) { | |
1713 | audit_log_format(ab, " inode=%lu" | |
1714 | " dev=%02x:%02x mode=%#ho" | |
1715 | " ouid=%u ogid=%u rdev=%02x:%02x", | |
1716 | n->ino, | |
1717 | MAJOR(n->dev), | |
1718 | MINOR(n->dev), | |
1719 | n->mode, | |
1720 | from_kuid(&init_user_ns, n->uid), | |
1721 | from_kgid(&init_user_ns, n->gid), | |
1722 | MAJOR(n->rdev), | |
1723 | MINOR(n->rdev)); | |
1724 | } | |
1725 | if (n->osid != 0) { | |
1726 | char *ctx = NULL; | |
1727 | u32 len; | |
1728 | if (security_secid_to_secctx( | |
1729 | n->osid, &ctx, &len)) { | |
1730 | audit_log_format(ab, " osid=%u", n->osid); | |
1731 | if (call_panic) | |
1732 | *call_panic = 2; | |
1733 | } else { | |
1734 | audit_log_format(ab, " obj=%s", ctx); | |
1735 | security_release_secctx(ctx, len); | |
1736 | } | |
1737 | } | |
1738 | ||
d3aea84a JL |
1739 | /* log the audit_names record type */ |
1740 | audit_log_format(ab, " nametype="); | |
1741 | switch(n->type) { | |
1742 | case AUDIT_TYPE_NORMAL: | |
1743 | audit_log_format(ab, "NORMAL"); | |
1744 | break; | |
1745 | case AUDIT_TYPE_PARENT: | |
1746 | audit_log_format(ab, "PARENT"); | |
1747 | break; | |
1748 | case AUDIT_TYPE_CHILD_DELETE: | |
1749 | audit_log_format(ab, "DELETE"); | |
1750 | break; | |
1751 | case AUDIT_TYPE_CHILD_CREATE: | |
1752 | audit_log_format(ab, "CREATE"); | |
1753 | break; | |
1754 | default: | |
1755 | audit_log_format(ab, "UNKNOWN"); | |
1756 | break; | |
1757 | } | |
1758 | ||
b24a30a7 EP |
1759 | audit_log_fcaps(ab, n); |
1760 | audit_log_end(ab); | |
1761 | } | |
1762 | ||
1763 | int audit_log_task_context(struct audit_buffer *ab) | |
1764 | { | |
1765 | char *ctx = NULL; | |
1766 | unsigned len; | |
1767 | int error; | |
1768 | u32 sid; | |
1769 | ||
1770 | security_task_getsecid(current, &sid); | |
1771 | if (!sid) | |
1772 | return 0; | |
1773 | ||
1774 | error = security_secid_to_secctx(sid, &ctx, &len); | |
1775 | if (error) { | |
1776 | if (error != -EINVAL) | |
1777 | goto error_path; | |
1778 | return 0; | |
1779 | } | |
1780 | ||
1781 | audit_log_format(ab, " subj=%s", ctx); | |
1782 | security_release_secctx(ctx, len); | |
1783 | return 0; | |
1784 | ||
1785 | error_path: | |
1786 | audit_panic("error in audit_log_task_context"); | |
1787 | return error; | |
1788 | } | |
1789 | EXPORT_SYMBOL(audit_log_task_context); | |
1790 | ||
1791 | void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) | |
1792 | { | |
1793 | const struct cred *cred; | |
1794 | char name[sizeof(tsk->comm)]; | |
1795 | struct mm_struct *mm = tsk->mm; | |
1796 | char *tty; | |
1797 | ||
1798 | if (!ab) | |
1799 | return; | |
1800 | ||
1801 | /* tsk == current */ | |
1802 | cred = current_cred(); | |
1803 | ||
1804 | spin_lock_irq(&tsk->sighand->siglock); | |
1805 | if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) | |
1806 | tty = tsk->signal->tty->name; | |
1807 | else | |
1808 | tty = "(none)"; | |
1809 | spin_unlock_irq(&tsk->sighand->siglock); | |
1810 | ||
1811 | audit_log_format(ab, | |
1812 | " ppid=%ld pid=%d auid=%u uid=%u gid=%u" | |
1813 | " euid=%u suid=%u fsuid=%u" | |
2f2ad101 | 1814 | " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", |
b24a30a7 EP |
1815 | sys_getppid(), |
1816 | tsk->pid, | |
1817 | from_kuid(&init_user_ns, audit_get_loginuid(tsk)), | |
1818 | from_kuid(&init_user_ns, cred->uid), | |
1819 | from_kgid(&init_user_ns, cred->gid), | |
1820 | from_kuid(&init_user_ns, cred->euid), | |
1821 | from_kuid(&init_user_ns, cred->suid), | |
1822 | from_kuid(&init_user_ns, cred->fsuid), | |
1823 | from_kgid(&init_user_ns, cred->egid), | |
1824 | from_kgid(&init_user_ns, cred->sgid), | |
1825 | from_kgid(&init_user_ns, cred->fsgid), | |
2f2ad101 | 1826 | tty, audit_get_sessionid(tsk)); |
b24a30a7 EP |
1827 | |
1828 | get_task_comm(name, tsk); | |
1829 | audit_log_format(ab, " comm="); | |
1830 | audit_log_untrustedstring(ab, name); | |
1831 | ||
1832 | if (mm) { | |
1833 | down_read(&mm->mmap_sem); | |
1834 | if (mm->exe_file) | |
1835 | audit_log_d_path(ab, " exe=", &mm->exe_file->f_path); | |
1836 | up_read(&mm->mmap_sem); | |
1837 | } | |
1838 | audit_log_task_context(ab); | |
1839 | } | |
1840 | EXPORT_SYMBOL(audit_log_task_info); | |
1841 | ||
a51d9eaa KC |
1842 | /** |
1843 | * audit_log_link_denied - report a link restriction denial | |
1844 | * @operation: specific link opreation | |
1845 | * @link: the path that triggered the restriction | |
1846 | */ | |
1847 | void audit_log_link_denied(const char *operation, struct path *link) | |
1848 | { | |
1849 | struct audit_buffer *ab; | |
b24a30a7 EP |
1850 | struct audit_names *name; |
1851 | ||
1852 | name = kzalloc(sizeof(*name), GFP_NOFS); | |
1853 | if (!name) | |
1854 | return; | |
a51d9eaa | 1855 | |
b24a30a7 | 1856 | /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ |
a51d9eaa KC |
1857 | ab = audit_log_start(current->audit_context, GFP_KERNEL, |
1858 | AUDIT_ANOM_LINK); | |
d1c7d97a | 1859 | if (!ab) |
b24a30a7 EP |
1860 | goto out; |
1861 | audit_log_format(ab, "op=%s", operation); | |
1862 | audit_log_task_info(ab, current); | |
1863 | audit_log_format(ab, " res=0"); | |
a51d9eaa | 1864 | audit_log_end(ab); |
b24a30a7 EP |
1865 | |
1866 | /* Generate AUDIT_PATH record with object. */ | |
1867 | name->type = AUDIT_TYPE_NORMAL; | |
1868 | audit_copy_inode(name, link->dentry, link->dentry->d_inode); | |
1869 | audit_log_name(current->audit_context, name, link, 0, NULL); | |
1870 | out: | |
1871 | kfree(name); | |
a51d9eaa KC |
1872 | } |
1873 | ||
b0dd25a8 RD |
1874 | /** |
1875 | * audit_log_end - end one audit record | |
1876 | * @ab: the audit_buffer | |
1877 | * | |
1878 | * The netlink_* functions cannot be called inside an irq context, so | |
1879 | * the audit buffer is placed on a queue and a tasklet is scheduled to | |
1da177e4 | 1880 | * remove them from the queue outside the irq context. May be called in |
b0dd25a8 RD |
1881 | * any context. |
1882 | */ | |
b7d11258 | 1883 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 1884 | { |
1da177e4 LT |
1885 | if (!ab) |
1886 | return; | |
1887 | if (!audit_rate_check()) { | |
1888 | audit_log_lost("rate limit exceeded"); | |
1889 | } else { | |
8d07a67c | 1890 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
94191213 | 1891 | nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN; |
f3d357b0 | 1892 | |
b7d11258 | 1893 | if (audit_pid) { |
b7d11258 | 1894 | skb_queue_tail(&audit_skb_queue, ab->skb); |
b7d11258 | 1895 | wake_up_interruptible(&kauditd_wait); |
f3d357b0 | 1896 | } else { |
038cbcf6 | 1897 | audit_printk_skb(ab->skb); |
b7d11258 | 1898 | } |
f3d357b0 | 1899 | ab->skb = NULL; |
1da177e4 | 1900 | } |
16e1904e | 1901 | audit_buffer_free(ab); |
1da177e4 LT |
1902 | } |
1903 | ||
b0dd25a8 RD |
1904 | /** |
1905 | * audit_log - Log an audit record | |
1906 | * @ctx: audit context | |
1907 | * @gfp_mask: type of allocation | |
1908 | * @type: audit message type | |
1909 | * @fmt: format string to use | |
1910 | * @...: variable parameters matching the format string | |
1911 | * | |
1912 | * This is a convenience function that calls audit_log_start, | |
1913 | * audit_log_vformat, and audit_log_end. It may be called | |
1914 | * in any context. | |
1915 | */ | |
5600b892 | 1916 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 1917 | const char *fmt, ...) |
1da177e4 LT |
1918 | { |
1919 | struct audit_buffer *ab; | |
1920 | va_list args; | |
1921 | ||
9ad9ad38 | 1922 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
1923 | if (ab) { |
1924 | va_start(args, fmt); | |
1925 | audit_log_vformat(ab, fmt, args); | |
1926 | va_end(args); | |
1927 | audit_log_end(ab); | |
1928 | } | |
1929 | } | |
bf45da97 | 1930 | |
131ad62d MDF |
1931 | #ifdef CONFIG_SECURITY |
1932 | /** | |
1933 | * audit_log_secctx - Converts and logs SELinux context | |
1934 | * @ab: audit_buffer | |
1935 | * @secid: security number | |
1936 | * | |
1937 | * This is a helper function that calls security_secid_to_secctx to convert | |
1938 | * secid to secctx and then adds the (converted) SELinux context to the audit | |
1939 | * log by calling audit_log_format, thus also preventing leak of internal secid | |
1940 | * to userspace. If secid cannot be converted audit_panic is called. | |
1941 | */ | |
1942 | void audit_log_secctx(struct audit_buffer *ab, u32 secid) | |
1943 | { | |
1944 | u32 len; | |
1945 | char *secctx; | |
1946 | ||
1947 | if (security_secid_to_secctx(secid, &secctx, &len)) { | |
1948 | audit_panic("Cannot convert secid to context"); | |
1949 | } else { | |
1950 | audit_log_format(ab, " obj=%s", secctx); | |
1951 | security_release_secctx(secctx, len); | |
1952 | } | |
1953 | } | |
1954 | EXPORT_SYMBOL(audit_log_secctx); | |
1955 | #endif | |
1956 | ||
bf45da97 | 1957 | EXPORT_SYMBOL(audit_log_start); |
1958 | EXPORT_SYMBOL(audit_log_end); | |
1959 | EXPORT_SYMBOL(audit_log_format); | |
1960 | EXPORT_SYMBOL(audit_log); |