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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 | ||
d957f7b7 JP |
44 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
45 | ||
5b282552 | 46 | #include <linux/file.h> |
1da177e4 | 47 | #include <linux/init.h> |
7153e402 | 48 | #include <linux/types.h> |
60063497 | 49 | #include <linux/atomic.h> |
1da177e4 | 50 | #include <linux/mm.h> |
9984de1a | 51 | #include <linux/export.h> |
5a0e3ad6 | 52 | #include <linux/slab.h> |
b7d11258 DW |
53 | #include <linux/err.h> |
54 | #include <linux/kthread.h> | |
46e959ea | 55 | #include <linux/kernel.h> |
b24a30a7 | 56 | #include <linux/syscalls.h> |
5b52330b PM |
57 | #include <linux/spinlock.h> |
58 | #include <linux/rcupdate.h> | |
59 | #include <linux/mutex.h> | |
60 | #include <linux/gfp.h> | |
1da177e4 LT |
61 | |
62 | #include <linux/audit.h> | |
63 | ||
64 | #include <net/sock.h> | |
93315ed6 | 65 | #include <net/netlink.h> |
1da177e4 | 66 | #include <linux/skbuff.h> |
131ad62d MDF |
67 | #ifdef CONFIG_SECURITY |
68 | #include <linux/security.h> | |
69 | #endif | |
7dfb7103 | 70 | #include <linux/freezer.h> |
34e36d8e | 71 | #include <linux/pid_namespace.h> |
33faba7f | 72 | #include <net/netns/generic.h> |
3dc7e315 DG |
73 | |
74 | #include "audit.h" | |
1da177e4 | 75 | |
a3f07114 | 76 | /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
1da177e4 | 77 | * (Initialization happens after skb_init is called.) */ |
a3f07114 EP |
78 | #define AUDIT_DISABLED -1 |
79 | #define AUDIT_UNINITIALIZED 0 | |
80 | #define AUDIT_INITIALIZED 1 | |
1da177e4 LT |
81 | static int audit_initialized; |
82 | ||
1a6b9f23 EP |
83 | #define AUDIT_OFF 0 |
84 | #define AUDIT_ON 1 | |
85 | #define AUDIT_LOCKED 2 | |
3e1d0bb6 JP |
86 | u32 audit_enabled; |
87 | u32 audit_ever_enabled; | |
1da177e4 | 88 | |
ae9d67af JE |
89 | EXPORT_SYMBOL_GPL(audit_enabled); |
90 | ||
1da177e4 | 91 | /* Default state when kernel boots without any parameters. */ |
3e1d0bb6 | 92 | static u32 audit_default; |
1da177e4 LT |
93 | |
94 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
3e1d0bb6 | 95 | static u32 audit_failure = AUDIT_FAIL_PRINTK; |
1da177e4 | 96 | |
5b52330b PM |
97 | /* private audit network namespace index */ |
98 | static unsigned int audit_net_id; | |
99 | ||
100 | /** | |
101 | * struct audit_net - audit private network namespace data | |
102 | * @sk: communication socket | |
103 | */ | |
104 | struct audit_net { | |
105 | struct sock *sk; | |
106 | }; | |
107 | ||
108 | /** | |
109 | * struct auditd_connection - kernel/auditd connection state | |
110 | * @pid: auditd PID | |
111 | * @portid: netlink portid | |
112 | * @net: the associated network namespace | |
113 | * @lock: spinlock to protect write access | |
114 | * | |
115 | * Description: | |
116 | * This struct is RCU protected; you must either hold the RCU lock for reading | |
117 | * or the included spinlock for writing. | |
75c0371a | 118 | */ |
5b52330b PM |
119 | static struct auditd_connection { |
120 | int pid; | |
121 | u32 portid; | |
122 | struct net *net; | |
123 | spinlock_t lock; | |
124 | } auditd_conn; | |
1da177e4 | 125 | |
b0dd25a8 | 126 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
127 | * to that number per second. This prevents DoS attacks, but results in |
128 | * audit records being dropped. */ | |
3e1d0bb6 | 129 | static u32 audit_rate_limit; |
1da177e4 | 130 | |
40c0775e RGB |
131 | /* Number of outstanding audit_buffers allowed. |
132 | * When set to zero, this means unlimited. */ | |
3e1d0bb6 | 133 | static u32 audit_backlog_limit = 64; |
e789e561 | 134 | #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ) |
3e1d0bb6 | 135 | static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; |
1da177e4 | 136 | |
c2f0c7c3 | 137 | /* The identity of the user shutting down the audit system. */ |
cca080d9 | 138 | kuid_t audit_sig_uid = INVALID_UID; |
c2f0c7c3 | 139 | pid_t audit_sig_pid = -1; |
e1396065 | 140 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 141 | |
1da177e4 LT |
142 | /* Records can be lost in several ways: |
143 | 0) [suppressed in audit_alloc] | |
144 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
145 | 2) out of memory in audit_log_move [alloc_skb] | |
146 | 3) suppressed due to audit_rate_limit | |
147 | 4) suppressed due to audit_backlog_limit | |
148 | */ | |
92c82e8a | 149 | static atomic_t audit_lost = ATOMIC_INIT(0); |
1da177e4 | 150 | |
f368c07d AG |
151 | /* Hash for inode-based rules */ |
152 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
153 | ||
b7d11258 | 154 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
1da177e4 LT |
155 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
156 | * being placed on the freelist). */ | |
1da177e4 | 157 | static DEFINE_SPINLOCK(audit_freelist_lock); |
b0dd25a8 | 158 | static int audit_freelist_count; |
1da177e4 LT |
159 | static LIST_HEAD(audit_freelist); |
160 | ||
c6480207 | 161 | /* queue msgs to send via kauditd_task */ |
af8b824f | 162 | static struct sk_buff_head audit_queue; |
c6480207 PM |
163 | /* queue msgs due to temporary unicast send problems */ |
164 | static struct sk_buff_head audit_retry_queue; | |
165 | /* queue msgs waiting for new auditd connection */ | |
af8b824f | 166 | static struct sk_buff_head audit_hold_queue; |
c6480207 PM |
167 | |
168 | /* queue servicing thread */ | |
b7d11258 DW |
169 | static struct task_struct *kauditd_task; |
170 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
c6480207 PM |
171 | |
172 | /* waitqueue for callers who are blocked on the audit backlog */ | |
9ad9ad38 | 173 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 174 | |
b0fed402 EP |
175 | static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION, |
176 | .mask = -1, | |
177 | .features = 0, | |
178 | .lock = 0,}; | |
179 | ||
21b85c31 | 180 | static char *audit_feature_names[2] = { |
d040e5af | 181 | "only_unset_loginuid", |
21b85c31 | 182 | "loginuid_immutable", |
b0fed402 EP |
183 | }; |
184 | ||
185 | ||
f368c07d | 186 | /* Serialize requests from userspace. */ |
916d7576 | 187 | DEFINE_MUTEX(audit_cmd_mutex); |
1da177e4 LT |
188 | |
189 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
190 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
191 | * should be at least that large. */ | |
192 | #define AUDIT_BUFSIZ 1024 | |
193 | ||
194 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the | |
195 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ | |
196 | #define AUDIT_MAXFREE (2*NR_CPUS) | |
197 | ||
198 | /* The audit_buffer is used when formatting an audit record. The caller | |
199 | * locks briefly to get the record off the freelist or to allocate the | |
200 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
201 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
202 | * use simultaneously. */ | |
203 | struct audit_buffer { | |
204 | struct list_head list; | |
8fc6115c | 205 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 206 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 207 | gfp_t gfp_mask; |
1da177e4 LT |
208 | }; |
209 | ||
f09ac9db | 210 | struct audit_reply { |
f9441639 | 211 | __u32 portid; |
638a0fd2 | 212 | struct net *net; |
f09ac9db EP |
213 | struct sk_buff *skb; |
214 | }; | |
215 | ||
5b52330b PM |
216 | /** |
217 | * auditd_test_task - Check to see if a given task is an audit daemon | |
218 | * @task: the task to check | |
219 | * | |
220 | * Description: | |
221 | * Return 1 if the task is a registered audit daemon, 0 otherwise. | |
222 | */ | |
223 | int auditd_test_task(const struct task_struct *task) | |
224 | { | |
225 | int rc; | |
226 | ||
227 | rcu_read_lock(); | |
228 | rc = (auditd_conn.pid && task->tgid == auditd_conn.pid ? 1 : 0); | |
229 | rcu_read_unlock(); | |
230 | ||
231 | return rc; | |
232 | } | |
233 | ||
234 | /** | |
235 | * audit_get_sk - Return the audit socket for the given network namespace | |
236 | * @net: the destination network namespace | |
237 | * | |
238 | * Description: | |
239 | * Returns the sock pointer if valid, NULL otherwise. The caller must ensure | |
240 | * that a reference is held for the network namespace while the sock is in use. | |
241 | */ | |
242 | static struct sock *audit_get_sk(const struct net *net) | |
243 | { | |
244 | struct audit_net *aunet; | |
245 | ||
246 | if (!net) | |
247 | return NULL; | |
248 | ||
249 | aunet = net_generic(net, audit_net_id); | |
250 | return aunet->sk; | |
251 | } | |
252 | ||
f9441639 | 253 | static void audit_set_portid(struct audit_buffer *ab, __u32 portid) |
c0404993 | 254 | { |
50397bd1 EP |
255 | if (ab) { |
256 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); | |
f9441639 | 257 | nlh->nlmsg_pid = portid; |
50397bd1 | 258 | } |
c0404993 SG |
259 | } |
260 | ||
8c8570fb | 261 | void audit_panic(const char *message) |
1da177e4 | 262 | { |
d957f7b7 | 263 | switch (audit_failure) { |
1da177e4 LT |
264 | case AUDIT_FAIL_SILENT: |
265 | break; | |
266 | case AUDIT_FAIL_PRINTK: | |
320f1b1e | 267 | if (printk_ratelimit()) |
d957f7b7 | 268 | pr_err("%s\n", message); |
1da177e4 LT |
269 | break; |
270 | case AUDIT_FAIL_PANIC: | |
5b52330b | 271 | panic("audit: %s\n", message); |
1da177e4 LT |
272 | break; |
273 | } | |
274 | } | |
275 | ||
276 | static inline int audit_rate_check(void) | |
277 | { | |
278 | static unsigned long last_check = 0; | |
279 | static int messages = 0; | |
280 | static DEFINE_SPINLOCK(lock); | |
281 | unsigned long flags; | |
282 | unsigned long now; | |
283 | unsigned long elapsed; | |
284 | int retval = 0; | |
285 | ||
286 | if (!audit_rate_limit) return 1; | |
287 | ||
288 | spin_lock_irqsave(&lock, flags); | |
289 | if (++messages < audit_rate_limit) { | |
290 | retval = 1; | |
291 | } else { | |
292 | now = jiffies; | |
293 | elapsed = now - last_check; | |
294 | if (elapsed > HZ) { | |
295 | last_check = now; | |
296 | messages = 0; | |
297 | retval = 1; | |
298 | } | |
299 | } | |
300 | spin_unlock_irqrestore(&lock, flags); | |
301 | ||
302 | return retval; | |
303 | } | |
304 | ||
b0dd25a8 RD |
305 | /** |
306 | * audit_log_lost - conditionally log lost audit message event | |
307 | * @message: the message stating reason for lost audit message | |
308 | * | |
309 | * Emit at least 1 message per second, even if audit_rate_check is | |
310 | * throttling. | |
311 | * Always increment the lost messages counter. | |
312 | */ | |
1da177e4 LT |
313 | void audit_log_lost(const char *message) |
314 | { | |
315 | static unsigned long last_msg = 0; | |
316 | static DEFINE_SPINLOCK(lock); | |
317 | unsigned long flags; | |
318 | unsigned long now; | |
319 | int print; | |
320 | ||
321 | atomic_inc(&audit_lost); | |
322 | ||
323 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
324 | ||
325 | if (!print) { | |
326 | spin_lock_irqsave(&lock, flags); | |
327 | now = jiffies; | |
328 | if (now - last_msg > HZ) { | |
329 | print = 1; | |
330 | last_msg = now; | |
331 | } | |
332 | spin_unlock_irqrestore(&lock, flags); | |
333 | } | |
334 | ||
335 | if (print) { | |
320f1b1e | 336 | if (printk_ratelimit()) |
3e1d0bb6 | 337 | pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n", |
320f1b1e EP |
338 | atomic_read(&audit_lost), |
339 | audit_rate_limit, | |
340 | audit_backlog_limit); | |
1da177e4 LT |
341 | audit_panic(message); |
342 | } | |
1da177e4 LT |
343 | } |
344 | ||
3e1d0bb6 | 345 | static int audit_log_config_change(char *function_name, u32 new, u32 old, |
2532386f | 346 | int allow_changes) |
1da177e4 | 347 | { |
1a6b9f23 EP |
348 | struct audit_buffer *ab; |
349 | int rc = 0; | |
ce29b682 | 350 | |
1a6b9f23 | 351 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
0644ec0c KC |
352 | if (unlikely(!ab)) |
353 | return rc; | |
3e1d0bb6 | 354 | audit_log_format(ab, "%s=%u old=%u", function_name, new, old); |
4d3fb709 | 355 | audit_log_session_info(ab); |
b122c376 EP |
356 | rc = audit_log_task_context(ab); |
357 | if (rc) | |
358 | allow_changes = 0; /* Something weird, deny request */ | |
1a6b9f23 EP |
359 | audit_log_format(ab, " res=%d", allow_changes); |
360 | audit_log_end(ab); | |
6a01b07f | 361 | return rc; |
1da177e4 LT |
362 | } |
363 | ||
3e1d0bb6 | 364 | static int audit_do_config_change(char *function_name, u32 *to_change, u32 new) |
1da177e4 | 365 | { |
3e1d0bb6 JP |
366 | int allow_changes, rc = 0; |
367 | u32 old = *to_change; | |
6a01b07f SG |
368 | |
369 | /* check if we are locked */ | |
1a6b9f23 EP |
370 | if (audit_enabled == AUDIT_LOCKED) |
371 | allow_changes = 0; | |
6a01b07f | 372 | else |
1a6b9f23 | 373 | allow_changes = 1; |
ce29b682 | 374 | |
1a6b9f23 | 375 | if (audit_enabled != AUDIT_OFF) { |
dc9eb698 | 376 | rc = audit_log_config_change(function_name, new, old, allow_changes); |
1a6b9f23 EP |
377 | if (rc) |
378 | allow_changes = 0; | |
6a01b07f | 379 | } |
6a01b07f SG |
380 | |
381 | /* If we are allowed, make the change */ | |
1a6b9f23 EP |
382 | if (allow_changes == 1) |
383 | *to_change = new; | |
6a01b07f SG |
384 | /* Not allowed, update reason */ |
385 | else if (rc == 0) | |
386 | rc = -EPERM; | |
387 | return rc; | |
1da177e4 LT |
388 | } |
389 | ||
3e1d0bb6 | 390 | static int audit_set_rate_limit(u32 limit) |
1da177e4 | 391 | { |
dc9eb698 | 392 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); |
1a6b9f23 | 393 | } |
ce29b682 | 394 | |
3e1d0bb6 | 395 | static int audit_set_backlog_limit(u32 limit) |
1a6b9f23 | 396 | { |
dc9eb698 | 397 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); |
1a6b9f23 | 398 | } |
6a01b07f | 399 | |
3e1d0bb6 | 400 | static int audit_set_backlog_wait_time(u32 timeout) |
51cc83f0 RGB |
401 | { |
402 | return audit_do_config_change("audit_backlog_wait_time", | |
31975424 | 403 | &audit_backlog_wait_time, timeout); |
51cc83f0 RGB |
404 | } |
405 | ||
3e1d0bb6 | 406 | static int audit_set_enabled(u32 state) |
1a6b9f23 | 407 | { |
b593d384 | 408 | int rc; |
724e7bfc | 409 | if (state > AUDIT_LOCKED) |
1a6b9f23 | 410 | return -EINVAL; |
6a01b07f | 411 | |
dc9eb698 | 412 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
b593d384 EP |
413 | if (!rc) |
414 | audit_ever_enabled |= !!state; | |
415 | ||
416 | return rc; | |
1da177e4 LT |
417 | } |
418 | ||
3e1d0bb6 | 419 | static int audit_set_failure(u32 state) |
1da177e4 | 420 | { |
1da177e4 LT |
421 | if (state != AUDIT_FAIL_SILENT |
422 | && state != AUDIT_FAIL_PRINTK | |
423 | && state != AUDIT_FAIL_PANIC) | |
424 | return -EINVAL; | |
ce29b682 | 425 | |
dc9eb698 | 426 | return audit_do_config_change("audit_failure", &audit_failure, state); |
1da177e4 LT |
427 | } |
428 | ||
5b52330b PM |
429 | /** |
430 | * auditd_set - Set/Reset the auditd connection state | |
431 | * @pid: auditd PID | |
432 | * @portid: auditd netlink portid | |
433 | * @net: auditd network namespace pointer | |
434 | * | |
435 | * Description: | |
436 | * This function will obtain and drop network namespace references as | |
437 | * necessary. | |
438 | */ | |
439 | static void auditd_set(int pid, u32 portid, struct net *net) | |
440 | { | |
441 | unsigned long flags; | |
442 | ||
443 | spin_lock_irqsave(&auditd_conn.lock, flags); | |
444 | auditd_conn.pid = pid; | |
445 | auditd_conn.portid = portid; | |
446 | if (auditd_conn.net) | |
447 | put_net(auditd_conn.net); | |
448 | if (net) | |
449 | auditd_conn.net = get_net(net); | |
450 | else | |
451 | auditd_conn.net = NULL; | |
452 | spin_unlock_irqrestore(&auditd_conn.lock, flags); | |
453 | } | |
454 | ||
5b52330b PM |
455 | /** |
456 | * kauditd_print_skb - Print the audit record to the ring buffer | |
457 | * @skb: audit record | |
458 | * | |
459 | * Whatever the reason, this packet may not make it to the auditd connection | |
460 | * so write it via printk so the information isn't completely lost. | |
038cbcf6 | 461 | */ |
af8b824f | 462 | static void kauditd_printk_skb(struct sk_buff *skb) |
038cbcf6 EP |
463 | { |
464 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 465 | char *data = nlmsg_data(nlh); |
038cbcf6 | 466 | |
5b52330b PM |
467 | if (nlh->nlmsg_type != AUDIT_EOE && printk_ratelimit()) |
468 | pr_notice("type=%d %s\n", nlh->nlmsg_type, data); | |
469 | } | |
470 | ||
471 | /** | |
472 | * kauditd_rehold_skb - Handle a audit record send failure in the hold queue | |
473 | * @skb: audit record | |
474 | * | |
475 | * Description: | |
476 | * This should only be used by the kauditd_thread when it fails to flush the | |
477 | * hold queue. | |
478 | */ | |
479 | static void kauditd_rehold_skb(struct sk_buff *skb) | |
480 | { | |
481 | /* put the record back in the queue at the same place */ | |
482 | skb_queue_head(&audit_hold_queue, skb); | |
c6480207 PM |
483 | } |
484 | ||
485 | /** | |
486 | * kauditd_hold_skb - Queue an audit record, waiting for auditd | |
487 | * @skb: audit record | |
488 | * | |
489 | * Description: | |
490 | * Queue the audit record, waiting for an instance of auditd. When this | |
491 | * function is called we haven't given up yet on sending the record, but things | |
492 | * are not looking good. The first thing we want to do is try to write the | |
493 | * record via printk and then see if we want to try and hold on to the record | |
494 | * and queue it, if we have room. If we want to hold on to the record, but we | |
495 | * don't have room, record a record lost message. | |
496 | */ | |
497 | static void kauditd_hold_skb(struct sk_buff *skb) | |
498 | { | |
499 | /* at this point it is uncertain if we will ever send this to auditd so | |
500 | * try to send the message via printk before we go any further */ | |
501 | kauditd_printk_skb(skb); | |
502 | ||
503 | /* can we just silently drop the message? */ | |
504 | if (!audit_default) { | |
505 | kfree_skb(skb); | |
506 | return; | |
507 | } | |
508 | ||
509 | /* if we have room, queue the message */ | |
510 | if (!audit_backlog_limit || | |
511 | skb_queue_len(&audit_hold_queue) < audit_backlog_limit) { | |
512 | skb_queue_tail(&audit_hold_queue, skb); | |
513 | return; | |
514 | } | |
038cbcf6 | 515 | |
c6480207 PM |
516 | /* we have no other options - drop the message */ |
517 | audit_log_lost("kauditd hold queue overflow"); | |
518 | kfree_skb(skb); | |
038cbcf6 EP |
519 | } |
520 | ||
c6480207 PM |
521 | /** |
522 | * kauditd_retry_skb - Queue an audit record, attempt to send again to auditd | |
523 | * @skb: audit record | |
524 | * | |
525 | * Description: | |
526 | * Not as serious as kauditd_hold_skb() as we still have a connected auditd, | |
527 | * but for some reason we are having problems sending it audit records so | |
528 | * queue the given record and attempt to resend. | |
529 | */ | |
530 | static void kauditd_retry_skb(struct sk_buff *skb) | |
f3d357b0 | 531 | { |
c6480207 PM |
532 | /* NOTE: because records should only live in the retry queue for a |
533 | * short period of time, before either being sent or moved to the hold | |
534 | * queue, we don't currently enforce a limit on this queue */ | |
535 | skb_queue_tail(&audit_retry_queue, skb); | |
536 | } | |
32a1dbae | 537 | |
264d5096 PM |
538 | /** |
539 | * auditd_reset - Disconnect the auditd connection | |
540 | * | |
541 | * Description: | |
542 | * Break the auditd/kauditd connection and move all the queued records into the | |
543 | * hold queue in case auditd reconnects. | |
544 | */ | |
545 | static void auditd_reset(void) | |
546 | { | |
547 | struct sk_buff *skb; | |
548 | ||
549 | /* if it isn't already broken, break the connection */ | |
550 | rcu_read_lock(); | |
551 | if (auditd_conn.pid) | |
552 | auditd_set(0, 0, NULL); | |
553 | rcu_read_unlock(); | |
554 | ||
555 | /* flush all of the main and retry queues to the hold queue */ | |
556 | while ((skb = skb_dequeue(&audit_retry_queue))) | |
557 | kauditd_hold_skb(skb); | |
558 | while ((skb = skb_dequeue(&audit_queue))) | |
559 | kauditd_hold_skb(skb); | |
560 | } | |
561 | ||
c6480207 | 562 | /** |
5b52330b PM |
563 | * auditd_send_unicast_skb - Send a record via unicast to auditd |
564 | * @skb: audit record | |
c6480207 PM |
565 | * |
566 | * Description: | |
5b52330b PM |
567 | * Send a skb to the audit daemon, returns positive/zero values on success and |
568 | * negative values on failure; in all cases the skb will be consumed by this | |
569 | * function. If the send results in -ECONNREFUSED the connection with auditd | |
570 | * will be reset. This function may sleep so callers should not hold any locks | |
571 | * where this would cause a problem. | |
c6480207 | 572 | */ |
5b52330b | 573 | static int auditd_send_unicast_skb(struct sk_buff *skb) |
c6480207 | 574 | { |
5b52330b PM |
575 | int rc; |
576 | u32 portid; | |
577 | struct net *net; | |
578 | struct sock *sk; | |
579 | ||
580 | /* NOTE: we can't call netlink_unicast while in the RCU section so | |
581 | * take a reference to the network namespace and grab local | |
582 | * copies of the namespace, the sock, and the portid; the | |
583 | * namespace and sock aren't going to go away while we hold a | |
584 | * reference and if the portid does become invalid after the RCU | |
585 | * section netlink_unicast() should safely return an error */ | |
586 | ||
587 | rcu_read_lock(); | |
588 | if (!auditd_conn.pid) { | |
589 | rcu_read_unlock(); | |
590 | rc = -ECONNREFUSED; | |
591 | goto err; | |
533c7b69 | 592 | } |
5b52330b PM |
593 | net = auditd_conn.net; |
594 | get_net(net); | |
595 | sk = audit_get_sk(net); | |
596 | portid = auditd_conn.portid; | |
597 | rcu_read_unlock(); | |
c6480207 | 598 | |
5b52330b PM |
599 | rc = netlink_unicast(sk, skb, portid, 0); |
600 | put_net(net); | |
601 | if (rc < 0) | |
602 | goto err; | |
603 | ||
604 | return rc; | |
605 | ||
606 | err: | |
607 | if (rc == -ECONNREFUSED) | |
608 | auditd_reset(); | |
609 | return rc; | |
c6480207 PM |
610 | } |
611 | ||
612 | /** | |
5b52330b PM |
613 | * kauditd_send_queue - Helper for kauditd_thread to flush skb queues |
614 | * @sk: the sending sock | |
615 | * @portid: the netlink destination | |
616 | * @queue: the skb queue to process | |
617 | * @retry_limit: limit on number of netlink unicast failures | |
618 | * @skb_hook: per-skb hook for additional processing | |
619 | * @err_hook: hook called if the skb fails the netlink unicast send | |
620 | * | |
621 | * Description: | |
622 | * Run through the given queue and attempt to send the audit records to auditd, | |
623 | * returns zero on success, negative values on failure. It is up to the caller | |
624 | * to ensure that the @sk is valid for the duration of this function. | |
625 | * | |
c6480207 | 626 | */ |
5b52330b PM |
627 | static int kauditd_send_queue(struct sock *sk, u32 portid, |
628 | struct sk_buff_head *queue, | |
629 | unsigned int retry_limit, | |
630 | void (*skb_hook)(struct sk_buff *skb), | |
631 | void (*err_hook)(struct sk_buff *skb)) | |
c6480207 | 632 | { |
5b52330b PM |
633 | int rc = 0; |
634 | struct sk_buff *skb; | |
635 | static unsigned int failed = 0; | |
32a1dbae | 636 | |
5b52330b PM |
637 | /* NOTE: kauditd_thread takes care of all our locking, we just use |
638 | * the netlink info passed to us (e.g. sk and portid) */ | |
639 | ||
640 | while ((skb = skb_dequeue(queue))) { | |
641 | /* call the skb_hook for each skb we touch */ | |
642 | if (skb_hook) | |
643 | (*skb_hook)(skb); | |
644 | ||
645 | /* can we send to anyone via unicast? */ | |
646 | if (!sk) { | |
647 | if (err_hook) | |
648 | (*err_hook)(skb); | |
649 | continue; | |
650 | } | |
6c54e789 | 651 | |
5b52330b PM |
652 | /* grab an extra skb reference in case of error */ |
653 | skb_get(skb); | |
654 | rc = netlink_unicast(sk, skb, portid, 0); | |
655 | if (rc < 0) { | |
656 | /* fatal failure for our queue flush attempt? */ | |
657 | if (++failed >= retry_limit || | |
658 | rc == -ECONNREFUSED || rc == -EPERM) { | |
659 | /* yes - error processing for the queue */ | |
660 | sk = NULL; | |
661 | if (err_hook) | |
662 | (*err_hook)(skb); | |
663 | if (!skb_hook) | |
664 | goto out; | |
665 | /* keep processing with the skb_hook */ | |
666 | continue; | |
667 | } else | |
668 | /* no - requeue to preserve ordering */ | |
669 | skb_queue_head(queue, skb); | |
670 | } else { | |
671 | /* it worked - drop the extra reference and continue */ | |
672 | consume_skb(skb); | |
673 | failed = 0; | |
674 | } | |
c6480207 PM |
675 | } |
676 | ||
5b52330b PM |
677 | out: |
678 | return (rc >= 0 ? 0 : rc); | |
f3d357b0 EP |
679 | } |
680 | ||
451f9216 | 681 | /* |
c6480207 PM |
682 | * kauditd_send_multicast_skb - Send a record to any multicast listeners |
683 | * @skb: audit record | |
451f9216 | 684 | * |
c6480207 | 685 | * Description: |
5b52330b PM |
686 | * Write a multicast message to anyone listening in the initial network |
687 | * namespace. This function doesn't consume an skb as might be expected since | |
688 | * it has to copy it anyways. | |
451f9216 | 689 | */ |
c6480207 | 690 | static void kauditd_send_multicast_skb(struct sk_buff *skb) |
451f9216 | 691 | { |
c6480207 | 692 | struct sk_buff *copy; |
5b52330b | 693 | struct sock *sock = audit_get_sk(&init_net); |
c6480207 | 694 | struct nlmsghdr *nlh; |
451f9216 | 695 | |
5b52330b PM |
696 | /* NOTE: we are not taking an additional reference for init_net since |
697 | * we don't have to worry about it going away */ | |
698 | ||
7f74ecd7 RGB |
699 | if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG)) |
700 | return; | |
701 | ||
451f9216 RGB |
702 | /* |
703 | * The seemingly wasteful skb_copy() rather than bumping the refcount | |
704 | * using skb_get() is necessary because non-standard mods are made to | |
705 | * the skb by the original kaudit unicast socket send routine. The | |
706 | * existing auditd daemon assumes this breakage. Fixing this would | |
707 | * require co-ordinating a change in the established protocol between | |
708 | * the kaudit kernel subsystem and the auditd userspace code. There is | |
709 | * no reason for new multicast clients to continue with this | |
710 | * non-compliance. | |
711 | */ | |
c6480207 | 712 | copy = skb_copy(skb, GFP_KERNEL); |
451f9216 RGB |
713 | if (!copy) |
714 | return; | |
c6480207 PM |
715 | nlh = nlmsg_hdr(copy); |
716 | nlh->nlmsg_len = skb->len; | |
451f9216 | 717 | |
c6480207 | 718 | nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL); |
451f9216 RGB |
719 | } |
720 | ||
c6480207 | 721 | /** |
5b52330b PM |
722 | * kauditd_thread - Worker thread to send audit records to userspace |
723 | * @dummy: unused | |
b551d1d9 | 724 | */ |
97a41e26 | 725 | static int kauditd_thread(void *dummy) |
b7d11258 | 726 | { |
c6480207 | 727 | int rc; |
5b52330b PM |
728 | u32 portid = 0; |
729 | struct net *net = NULL; | |
730 | struct sock *sk = NULL; | |
4aa83872 | 731 | |
c6480207 | 732 | #define UNICAST_RETRIES 5 |
c6480207 | 733 | |
83144186 | 734 | set_freezable(); |
4899b8b1 | 735 | while (!kthread_should_stop()) { |
5b52330b PM |
736 | /* NOTE: see the lock comments in auditd_send_unicast_skb() */ |
737 | rcu_read_lock(); | |
738 | if (!auditd_conn.pid) { | |
739 | rcu_read_unlock(); | |
740 | goto main_queue; | |
741 | } | |
742 | net = auditd_conn.net; | |
743 | get_net(net); | |
744 | sk = audit_get_sk(net); | |
745 | portid = auditd_conn.portid; | |
746 | rcu_read_unlock(); | |
c6480207 PM |
747 | |
748 | /* attempt to flush the hold queue */ | |
5b52330b PM |
749 | rc = kauditd_send_queue(sk, portid, |
750 | &audit_hold_queue, UNICAST_RETRIES, | |
751 | NULL, kauditd_rehold_skb); | |
752 | if (rc < 0) { | |
753 | sk = NULL; | |
264d5096 | 754 | auditd_reset(); |
5b52330b | 755 | goto main_queue; |
c6480207 | 756 | } |
f3d357b0 | 757 | |
c6480207 | 758 | /* attempt to flush the retry queue */ |
5b52330b PM |
759 | rc = kauditd_send_queue(sk, portid, |
760 | &audit_retry_queue, UNICAST_RETRIES, | |
761 | NULL, kauditd_hold_skb); | |
762 | if (rc < 0) { | |
763 | sk = NULL; | |
264d5096 | 764 | auditd_reset(); |
5b52330b | 765 | goto main_queue; |
c6480207 | 766 | } |
db897319 | 767 | |
5b52330b PM |
768 | main_queue: |
769 | /* process the main queue - do the multicast send and attempt | |
770 | * unicast, dump failed record sends to the retry queue; if | |
771 | * sk == NULL due to previous failures we will just do the | |
772 | * multicast send and move the record to the retry queue */ | |
264d5096 PM |
773 | rc = kauditd_send_queue(sk, portid, &audit_queue, 1, |
774 | kauditd_send_multicast_skb, | |
775 | kauditd_retry_skb); | |
776 | if (sk == NULL || rc < 0) | |
777 | auditd_reset(); | |
778 | sk = NULL; | |
5b52330b PM |
779 | |
780 | /* drop our netns reference, no auditd sends past this line */ | |
781 | if (net) { | |
782 | put_net(net); | |
783 | net = NULL; | |
3320c513 | 784 | } |
5b52330b PM |
785 | |
786 | /* we have processed all the queues so wake everyone */ | |
787 | wake_up(&audit_backlog_wait); | |
788 | ||
789 | /* NOTE: we want to wake up if there is anything on the queue, | |
790 | * regardless of if an auditd is connected, as we need to | |
791 | * do the multicast send and rotate records from the | |
792 | * main queue to the retry/hold queues */ | |
793 | wait_event_freezable(kauditd_wait, | |
794 | (skb_queue_len(&audit_queue) ? 1 : 0)); | |
b7d11258 | 795 | } |
c6480207 | 796 | |
4899b8b1 | 797 | return 0; |
b7d11258 DW |
798 | } |
799 | ||
9044e6bc AV |
800 | int audit_send_list(void *_dest) |
801 | { | |
802 | struct audit_netlink_list *dest = _dest; | |
9044e6bc | 803 | struct sk_buff *skb; |
5b52330b | 804 | struct sock *sk = audit_get_sk(dest->net); |
9044e6bc AV |
805 | |
806 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
807 | mutex_lock(&audit_cmd_mutex); |
808 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
809 | |
810 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
5b52330b | 811 | netlink_unicast(sk, skb, dest->portid, 0); |
9044e6bc | 812 | |
5b52330b | 813 | put_net(dest->net); |
9044e6bc AV |
814 | kfree(dest); |
815 | ||
816 | return 0; | |
817 | } | |
818 | ||
f9441639 | 819 | struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done, |
b8800aa5 | 820 | int multi, const void *payload, int size) |
9044e6bc AV |
821 | { |
822 | struct sk_buff *skb; | |
823 | struct nlmsghdr *nlh; | |
9044e6bc AV |
824 | void *data; |
825 | int flags = multi ? NLM_F_MULTI : 0; | |
826 | int t = done ? NLMSG_DONE : type; | |
827 | ||
ee080e6c | 828 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
829 | if (!skb) |
830 | return NULL; | |
831 | ||
f9441639 | 832 | nlh = nlmsg_put(skb, portid, seq, t, size, flags); |
c64e66c6 DM |
833 | if (!nlh) |
834 | goto out_kfree_skb; | |
835 | data = nlmsg_data(nlh); | |
9044e6bc AV |
836 | memcpy(data, payload, size); |
837 | return skb; | |
838 | ||
c64e66c6 DM |
839 | out_kfree_skb: |
840 | kfree_skb(skb); | |
9044e6bc AV |
841 | return NULL; |
842 | } | |
843 | ||
f09ac9db EP |
844 | static int audit_send_reply_thread(void *arg) |
845 | { | |
846 | struct audit_reply *reply = (struct audit_reply *)arg; | |
5b52330b | 847 | struct sock *sk = audit_get_sk(reply->net); |
f09ac9db EP |
848 | |
849 | mutex_lock(&audit_cmd_mutex); | |
850 | mutex_unlock(&audit_cmd_mutex); | |
851 | ||
852 | /* Ignore failure. It'll only happen if the sender goes away, | |
853 | because our timeout is set to infinite. */ | |
5b52330b PM |
854 | netlink_unicast(sk, reply->skb, reply->portid, 0); |
855 | put_net(reply->net); | |
f09ac9db EP |
856 | kfree(reply); |
857 | return 0; | |
858 | } | |
c6480207 | 859 | |
b0dd25a8 RD |
860 | /** |
861 | * audit_send_reply - send an audit reply message via netlink | |
d211f177 | 862 | * @request_skb: skb of request we are replying to (used to target the reply) |
b0dd25a8 RD |
863 | * @seq: sequence number |
864 | * @type: audit message type | |
865 | * @done: done (last) flag | |
866 | * @multi: multi-part message flag | |
867 | * @payload: payload data | |
868 | * @size: payload size | |
869 | * | |
f9441639 | 870 | * Allocates an skb, builds the netlink message, and sends it to the port id. |
b0dd25a8 RD |
871 | * No failure notifications. |
872 | */ | |
6f285b19 | 873 | static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done, |
f9441639 | 874 | int multi, const void *payload, int size) |
1da177e4 | 875 | { |
6f285b19 EB |
876 | u32 portid = NETLINK_CB(request_skb).portid; |
877 | struct net *net = sock_net(NETLINK_CB(request_skb).sk); | |
f09ac9db EP |
878 | struct sk_buff *skb; |
879 | struct task_struct *tsk; | |
880 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), | |
881 | GFP_KERNEL); | |
882 | ||
883 | if (!reply) | |
884 | return; | |
885 | ||
f9441639 | 886 | skb = audit_make_reply(portid, seq, type, done, multi, payload, size); |
1da177e4 | 887 | if (!skb) |
fcaf1eb8 | 888 | goto out; |
f09ac9db | 889 | |
6f285b19 | 890 | reply->net = get_net(net); |
f9441639 | 891 | reply->portid = portid; |
f09ac9db EP |
892 | reply->skb = skb; |
893 | ||
894 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
fcaf1eb8 AM |
895 | if (!IS_ERR(tsk)) |
896 | return; | |
897 | kfree_skb(skb); | |
898 | out: | |
899 | kfree(reply); | |
1da177e4 LT |
900 | } |
901 | ||
902 | /* | |
903 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
904 | * control messages. | |
905 | */ | |
c7bdb545 | 906 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
907 | { |
908 | int err = 0; | |
909 | ||
5a3cb3b6 | 910 | /* Only support initial user namespace for now. */ |
aa4af831 EP |
911 | /* |
912 | * We return ECONNREFUSED because it tricks userspace into thinking | |
913 | * that audit was not configured into the kernel. Lots of users | |
914 | * configure their PAM stack (because that's what the distro does) | |
915 | * to reject login if unable to send messages to audit. If we return | |
916 | * ECONNREFUSED the PAM stack thinks the kernel does not have audit | |
917 | * configured in and will let login proceed. If we return EPERM | |
918 | * userspace will reject all logins. This should be removed when we | |
919 | * support non init namespaces!! | |
920 | */ | |
0b747172 | 921 | if (current_user_ns() != &init_user_ns) |
aa4af831 | 922 | return -ECONNREFUSED; |
34e36d8e | 923 | |
1da177e4 | 924 | switch (msg_type) { |
1da177e4 | 925 | case AUDIT_LIST: |
1da177e4 LT |
926 | case AUDIT_ADD: |
927 | case AUDIT_DEL: | |
18900909 EP |
928 | return -EOPNOTSUPP; |
929 | case AUDIT_GET: | |
930 | case AUDIT_SET: | |
b0fed402 EP |
931 | case AUDIT_GET_FEATURE: |
932 | case AUDIT_SET_FEATURE: | |
18900909 EP |
933 | case AUDIT_LIST_RULES: |
934 | case AUDIT_ADD_RULE: | |
93315ed6 | 935 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 936 | case AUDIT_SIGNAL_INFO: |
522ed776 MT |
937 | case AUDIT_TTY_GET: |
938 | case AUDIT_TTY_SET: | |
74c3cbe3 AV |
939 | case AUDIT_TRIM: |
940 | case AUDIT_MAKE_EQUIV: | |
5a3cb3b6 RGB |
941 | /* Only support auditd and auditctl in initial pid namespace |
942 | * for now. */ | |
5985de67 | 943 | if (task_active_pid_ns(current) != &init_pid_ns) |
5a3cb3b6 RGB |
944 | return -EPERM; |
945 | ||
90f62cf3 | 946 | if (!netlink_capable(skb, CAP_AUDIT_CONTROL)) |
1da177e4 LT |
947 | err = -EPERM; |
948 | break; | |
05474106 | 949 | case AUDIT_USER: |
039b6b3e RD |
950 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
951 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
90f62cf3 | 952 | if (!netlink_capable(skb, CAP_AUDIT_WRITE)) |
1da177e4 LT |
953 | err = -EPERM; |
954 | break; | |
955 | default: /* bad msg */ | |
956 | err = -EINVAL; | |
957 | } | |
958 | ||
959 | return err; | |
960 | } | |
961 | ||
233a6866 | 962 | static void audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) |
50397bd1 | 963 | { |
dc9eb698 | 964 | uid_t uid = from_kuid(&init_user_ns, current_uid()); |
f1dc4867 | 965 | pid_t pid = task_tgid_nr(current); |
50397bd1 | 966 | |
0868a5e1 | 967 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) { |
50397bd1 | 968 | *ab = NULL; |
233a6866 | 969 | return; |
50397bd1 EP |
970 | } |
971 | ||
972 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); | |
0644ec0c | 973 | if (unlikely(!*ab)) |
233a6866 | 974 | return; |
f1dc4867 | 975 | audit_log_format(*ab, "pid=%d uid=%u", pid, uid); |
4d3fb709 | 976 | audit_log_session_info(*ab); |
b122c376 | 977 | audit_log_task_context(*ab); |
50397bd1 EP |
978 | } |
979 | ||
b0fed402 EP |
980 | int is_audit_feature_set(int i) |
981 | { | |
982 | return af.features & AUDIT_FEATURE_TO_MASK(i); | |
983 | } | |
984 | ||
985 | ||
986 | static int audit_get_feature(struct sk_buff *skb) | |
987 | { | |
988 | u32 seq; | |
989 | ||
990 | seq = nlmsg_hdr(skb)->nlmsg_seq; | |
991 | ||
9ef91514 | 992 | audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af)); |
b0fed402 EP |
993 | |
994 | return 0; | |
995 | } | |
996 | ||
997 | static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature, | |
998 | u32 old_lock, u32 new_lock, int res) | |
999 | { | |
1000 | struct audit_buffer *ab; | |
1001 | ||
b6c50fe0 G |
1002 | if (audit_enabled == AUDIT_OFF) |
1003 | return; | |
1004 | ||
b0fed402 | 1005 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE); |
ad2ac263 | 1006 | audit_log_task_info(ab, current); |
897f1acb | 1007 | audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d", |
b0fed402 EP |
1008 | audit_feature_names[which], !!old_feature, !!new_feature, |
1009 | !!old_lock, !!new_lock, res); | |
1010 | audit_log_end(ab); | |
1011 | } | |
1012 | ||
1013 | static int audit_set_feature(struct sk_buff *skb) | |
1014 | { | |
1015 | struct audit_features *uaf; | |
1016 | int i; | |
1017 | ||
6eed9b26 | 1018 | BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names)); |
b0fed402 EP |
1019 | uaf = nlmsg_data(nlmsg_hdr(skb)); |
1020 | ||
1021 | /* if there is ever a version 2 we should handle that here */ | |
1022 | ||
1023 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
1024 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
1025 | u32 old_feature, new_feature, old_lock, new_lock; | |
1026 | ||
1027 | /* if we are not changing this feature, move along */ | |
1028 | if (!(feature & uaf->mask)) | |
1029 | continue; | |
1030 | ||
1031 | old_feature = af.features & feature; | |
1032 | new_feature = uaf->features & feature; | |
1033 | new_lock = (uaf->lock | af.lock) & feature; | |
1034 | old_lock = af.lock & feature; | |
1035 | ||
1036 | /* are we changing a locked feature? */ | |
4547b3bc | 1037 | if (old_lock && (new_feature != old_feature)) { |
b0fed402 EP |
1038 | audit_log_feature_change(i, old_feature, new_feature, |
1039 | old_lock, new_lock, 0); | |
1040 | return -EPERM; | |
1041 | } | |
1042 | } | |
1043 | /* nothing invalid, do the changes */ | |
1044 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
1045 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
1046 | u32 old_feature, new_feature, old_lock, new_lock; | |
1047 | ||
1048 | /* if we are not changing this feature, move along */ | |
1049 | if (!(feature & uaf->mask)) | |
1050 | continue; | |
1051 | ||
1052 | old_feature = af.features & feature; | |
1053 | new_feature = uaf->features & feature; | |
1054 | old_lock = af.lock & feature; | |
1055 | new_lock = (uaf->lock | af.lock) & feature; | |
1056 | ||
1057 | if (new_feature != old_feature) | |
1058 | audit_log_feature_change(i, old_feature, new_feature, | |
1059 | old_lock, new_lock, 1); | |
1060 | ||
1061 | if (new_feature) | |
1062 | af.features |= feature; | |
1063 | else | |
1064 | af.features &= ~feature; | |
1065 | af.lock |= new_lock; | |
1066 | } | |
1067 | ||
1068 | return 0; | |
1069 | } | |
1070 | ||
133e1e5a RGB |
1071 | static int audit_replace(pid_t pid) |
1072 | { | |
5b52330b | 1073 | struct sk_buff *skb; |
133e1e5a | 1074 | |
5b52330b | 1075 | skb = audit_make_reply(0, 0, AUDIT_REPLACE, 0, 0, &pid, sizeof(pid)); |
133e1e5a RGB |
1076 | if (!skb) |
1077 | return -ENOMEM; | |
5b52330b | 1078 | return auditd_send_unicast_skb(skb); |
133e1e5a RGB |
1079 | } |
1080 | ||
1da177e4 LT |
1081 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
1082 | { | |
dc9eb698 | 1083 | u32 seq; |
1da177e4 | 1084 | void *data; |
1da177e4 | 1085 | int err; |
c0404993 | 1086 | struct audit_buffer *ab; |
1da177e4 | 1087 | u16 msg_type = nlh->nlmsg_type; |
e1396065 | 1088 | struct audit_sig_info *sig_data; |
50397bd1 | 1089 | char *ctx = NULL; |
e1396065 | 1090 | u32 len; |
1da177e4 | 1091 | |
c7bdb545 | 1092 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
1093 | if (err) |
1094 | return err; | |
1095 | ||
1da177e4 | 1096 | seq = nlh->nlmsg_seq; |
c64e66c6 | 1097 | data = nlmsg_data(nlh); |
1da177e4 LT |
1098 | |
1099 | switch (msg_type) { | |
09f883a9 RGB |
1100 | case AUDIT_GET: { |
1101 | struct audit_status s; | |
1102 | memset(&s, 0, sizeof(s)); | |
1103 | s.enabled = audit_enabled; | |
1104 | s.failure = audit_failure; | |
5b52330b PM |
1105 | rcu_read_lock(); |
1106 | s.pid = auditd_conn.pid; | |
1107 | rcu_read_unlock(); | |
09f883a9 RGB |
1108 | s.rate_limit = audit_rate_limit; |
1109 | s.backlog_limit = audit_backlog_limit; | |
1110 | s.lost = atomic_read(&audit_lost); | |
af8b824f | 1111 | s.backlog = skb_queue_len(&audit_queue); |
0288d718 | 1112 | s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL; |
31975424 | 1113 | s.backlog_wait_time = audit_backlog_wait_time; |
6f285b19 | 1114 | audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s)); |
1da177e4 | 1115 | break; |
09f883a9 RGB |
1116 | } |
1117 | case AUDIT_SET: { | |
1118 | struct audit_status s; | |
1119 | memset(&s, 0, sizeof(s)); | |
1120 | /* guard against past and future API changes */ | |
1121 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); | |
1122 | if (s.mask & AUDIT_STATUS_ENABLED) { | |
1123 | err = audit_set_enabled(s.enabled); | |
20c6aaa3 | 1124 | if (err < 0) |
1125 | return err; | |
1da177e4 | 1126 | } |
09f883a9 RGB |
1127 | if (s.mask & AUDIT_STATUS_FAILURE) { |
1128 | err = audit_set_failure(s.failure); | |
20c6aaa3 | 1129 | if (err < 0) |
1130 | return err; | |
1da177e4 | 1131 | } |
09f883a9 | 1132 | if (s.mask & AUDIT_STATUS_PID) { |
fa2bea2f PM |
1133 | /* NOTE: we are using task_tgid_vnr() below because |
1134 | * the s.pid value is relative to the namespace | |
1135 | * of the caller; at present this doesn't matter | |
1136 | * much since you can really only run auditd | |
1137 | * from the initial pid namespace, but something | |
1138 | * to keep in mind if this changes */ | |
09f883a9 | 1139 | int new_pid = s.pid; |
5b52330b | 1140 | pid_t auditd_pid; |
133e1e5a | 1141 | pid_t requesting_pid = task_tgid_vnr(current); |
1a6b9f23 | 1142 | |
5b52330b PM |
1143 | /* test the auditd connection */ |
1144 | audit_replace(requesting_pid); | |
1145 | ||
1146 | rcu_read_lock(); | |
1147 | auditd_pid = auditd_conn.pid; | |
1148 | /* only the current auditd can unregister itself */ | |
1149 | if ((!new_pid) && (requesting_pid != auditd_pid)) { | |
1150 | rcu_read_unlock(); | |
1151 | audit_log_config_change("audit_pid", new_pid, | |
1152 | auditd_pid, 0); | |
34eab0a7 | 1153 | return -EACCES; |
935c9e7f | 1154 | } |
5b52330b PM |
1155 | /* replacing a healthy auditd is not allowed */ |
1156 | if (auditd_pid && new_pid) { | |
1157 | rcu_read_unlock(); | |
1158 | audit_log_config_change("audit_pid", new_pid, | |
1159 | auditd_pid, 0); | |
133e1e5a | 1160 | return -EEXIST; |
935c9e7f | 1161 | } |
5b52330b PM |
1162 | rcu_read_unlock(); |
1163 | ||
1a6b9f23 | 1164 | if (audit_enabled != AUDIT_OFF) |
5b52330b PM |
1165 | audit_log_config_change("audit_pid", new_pid, |
1166 | auditd_pid, 1); | |
1167 | ||
533c7b69 | 1168 | if (new_pid) { |
5b52330b PM |
1169 | /* register a new auditd connection */ |
1170 | auditd_set(new_pid, | |
1171 | NETLINK_CB(skb).portid, | |
1172 | sock_net(NETLINK_CB(skb).sk)); | |
1173 | /* try to process any backlog */ | |
1174 | wake_up_interruptible(&kauditd_wait); | |
1175 | } else | |
1176 | /* unregister the auditd connection */ | |
6c54e789 | 1177 | auditd_reset(); |
1da177e4 | 1178 | } |
09f883a9 RGB |
1179 | if (s.mask & AUDIT_STATUS_RATE_LIMIT) { |
1180 | err = audit_set_rate_limit(s.rate_limit); | |
20c6aaa3 | 1181 | if (err < 0) |
1182 | return err; | |
1183 | } | |
51cc83f0 | 1184 | if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) { |
09f883a9 | 1185 | err = audit_set_backlog_limit(s.backlog_limit); |
51cc83f0 RGB |
1186 | if (err < 0) |
1187 | return err; | |
1188 | } | |
3f0c5fad EP |
1189 | if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) { |
1190 | if (sizeof(s) > (size_t)nlh->nlmsg_len) | |
1191 | return -EINVAL; | |
724e7bfc | 1192 | if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME) |
3f0c5fad EP |
1193 | return -EINVAL; |
1194 | err = audit_set_backlog_wait_time(s.backlog_wait_time); | |
1195 | if (err < 0) | |
1196 | return err; | |
51cc83f0 | 1197 | } |
92c82e8a RGB |
1198 | if (s.mask == AUDIT_STATUS_LOST) { |
1199 | u32 lost = atomic_xchg(&audit_lost, 0); | |
1200 | ||
1201 | audit_log_config_change("lost", 0, lost, 1); | |
1202 | return lost; | |
1203 | } | |
1da177e4 | 1204 | break; |
09f883a9 | 1205 | } |
b0fed402 EP |
1206 | case AUDIT_GET_FEATURE: |
1207 | err = audit_get_feature(skb); | |
1208 | if (err) | |
1209 | return err; | |
1210 | break; | |
1211 | case AUDIT_SET_FEATURE: | |
1212 | err = audit_set_feature(skb); | |
1213 | if (err) | |
1214 | return err; | |
1215 | break; | |
05474106 | 1216 | case AUDIT_USER: |
039b6b3e RD |
1217 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
1218 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
1219 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
1220 | return 0; | |
1221 | ||
86b2efbe | 1222 | err = audit_filter(msg_type, AUDIT_FILTER_USER); |
724e4fcc | 1223 | if (err == 1) { /* match or error */ |
4a4cd633 | 1224 | err = 0; |
522ed776 | 1225 | if (msg_type == AUDIT_USER_TTY) { |
37282a77 | 1226 | err = tty_audit_push(); |
522ed776 MT |
1227 | if (err) |
1228 | break; | |
1229 | } | |
dc9eb698 | 1230 | audit_log_common_recv_msg(&ab, msg_type); |
50397bd1 | 1231 | if (msg_type != AUDIT_USER_TTY) |
b50eba7e RGB |
1232 | audit_log_format(ab, " msg='%.*s'", |
1233 | AUDIT_MESSAGE_TEXT_MAX, | |
50397bd1 EP |
1234 | (char *)data); |
1235 | else { | |
1236 | int size; | |
1237 | ||
f7616102 | 1238 | audit_log_format(ab, " data="); |
50397bd1 | 1239 | size = nlmsg_len(nlh); |
55ad2f8d MT |
1240 | if (size > 0 && |
1241 | ((unsigned char *)data)[size - 1] == '\0') | |
1242 | size--; | |
b556f8ad | 1243 | audit_log_n_untrustedstring(ab, data, size); |
4a4cd633 | 1244 | } |
f9441639 | 1245 | audit_set_portid(ab, NETLINK_CB(skb).portid); |
50397bd1 | 1246 | audit_log_end(ab); |
0f45aa18 | 1247 | } |
1da177e4 | 1248 | break; |
93315ed6 AG |
1249 | case AUDIT_ADD_RULE: |
1250 | case AUDIT_DEL_RULE: | |
1251 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
1252 | return -EINVAL; | |
1a6b9f23 | 1253 | if (audit_enabled == AUDIT_LOCKED) { |
dc9eb698 EP |
1254 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
1255 | audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); | |
50397bd1 | 1256 | audit_log_end(ab); |
6a01b07f SG |
1257 | return -EPERM; |
1258 | } | |
ce0d9f04 | 1259 | err = audit_rule_change(msg_type, NETLINK_CB(skb).portid, |
dc9eb698 | 1260 | seq, data, nlmsg_len(nlh)); |
1da177e4 | 1261 | break; |
ce0d9f04 | 1262 | case AUDIT_LIST_RULES: |
6f285b19 | 1263 | err = audit_list_rules_send(skb, seq); |
ce0d9f04 | 1264 | break; |
74c3cbe3 AV |
1265 | case AUDIT_TRIM: |
1266 | audit_trim_trees(); | |
dc9eb698 | 1267 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
74c3cbe3 AV |
1268 | audit_log_format(ab, " op=trim res=1"); |
1269 | audit_log_end(ab); | |
1270 | break; | |
1271 | case AUDIT_MAKE_EQUIV: { | |
1272 | void *bufp = data; | |
1273 | u32 sizes[2]; | |
7719e437 | 1274 | size_t msglen = nlmsg_len(nlh); |
74c3cbe3 AV |
1275 | char *old, *new; |
1276 | ||
1277 | err = -EINVAL; | |
7719e437 | 1278 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
1279 | break; |
1280 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
1281 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
1282 | msglen -= 2 * sizeof(u32); |
1283 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
1284 | if (IS_ERR(old)) { |
1285 | err = PTR_ERR(old); | |
1286 | break; | |
1287 | } | |
7719e437 | 1288 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
1289 | if (IS_ERR(new)) { |
1290 | err = PTR_ERR(new); | |
1291 | kfree(old); | |
1292 | break; | |
1293 | } | |
1294 | /* OK, here comes... */ | |
1295 | err = audit_tag_tree(old, new); | |
1296 | ||
dc9eb698 | 1297 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
50397bd1 | 1298 | |
74c3cbe3 AV |
1299 | audit_log_format(ab, " op=make_equiv old="); |
1300 | audit_log_untrustedstring(ab, old); | |
1301 | audit_log_format(ab, " new="); | |
1302 | audit_log_untrustedstring(ab, new); | |
1303 | audit_log_format(ab, " res=%d", !err); | |
1304 | audit_log_end(ab); | |
1305 | kfree(old); | |
1306 | kfree(new); | |
1307 | break; | |
1308 | } | |
c2f0c7c3 | 1309 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
1310 | len = 0; |
1311 | if (audit_sig_sid) { | |
1312 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
1313 | if (err) | |
1314 | return err; | |
1315 | } | |
e1396065 AV |
1316 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
1317 | if (!sig_data) { | |
939cbf26 EP |
1318 | if (audit_sig_sid) |
1319 | security_release_secctx(ctx, len); | |
e1396065 AV |
1320 | return -ENOMEM; |
1321 | } | |
cca080d9 | 1322 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
e1396065 | 1323 | sig_data->pid = audit_sig_pid; |
939cbf26 EP |
1324 | if (audit_sig_sid) { |
1325 | memcpy(sig_data->ctx, ctx, len); | |
1326 | security_release_secctx(ctx, len); | |
1327 | } | |
6f285b19 EB |
1328 | audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0, |
1329 | sig_data, sizeof(*sig_data) + len); | |
e1396065 | 1330 | kfree(sig_data); |
c2f0c7c3 | 1331 | break; |
522ed776 MT |
1332 | case AUDIT_TTY_GET: { |
1333 | struct audit_tty_status s; | |
2e28d38a | 1334 | unsigned int t; |
8aa14b64 | 1335 | |
2e28d38a PH |
1336 | t = READ_ONCE(current->signal->audit_tty); |
1337 | s.enabled = t & AUDIT_TTY_ENABLE; | |
1338 | s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD); | |
8aa14b64 | 1339 | |
6f285b19 | 1340 | audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
522ed776 MT |
1341 | break; |
1342 | } | |
1343 | case AUDIT_TTY_SET: { | |
a06e56b2 | 1344 | struct audit_tty_status s, old; |
a06e56b2 | 1345 | struct audit_buffer *ab; |
2e28d38a | 1346 | unsigned int t; |
0e23bacc EP |
1347 | |
1348 | memset(&s, 0, sizeof(s)); | |
1349 | /* guard against past and future API changes */ | |
1350 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); | |
1351 | /* check if new data is valid */ | |
1352 | if ((s.enabled != 0 && s.enabled != 1) || | |
1353 | (s.log_passwd != 0 && s.log_passwd != 1)) | |
1354 | err = -EINVAL; | |
a06e56b2 | 1355 | |
2e28d38a PH |
1356 | if (err) |
1357 | t = READ_ONCE(current->signal->audit_tty); | |
1358 | else { | |
1359 | t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD); | |
1360 | t = xchg(¤t->signal->audit_tty, t); | |
0e23bacc | 1361 | } |
2e28d38a PH |
1362 | old.enabled = t & AUDIT_TTY_ENABLE; |
1363 | old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD); | |
522ed776 | 1364 | |
a06e56b2 | 1365 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
1ce319f1 EP |
1366 | audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d" |
1367 | " old-log_passwd=%d new-log_passwd=%d res=%d", | |
1368 | old.enabled, s.enabled, old.log_passwd, | |
1369 | s.log_passwd, !err); | |
a06e56b2 | 1370 | audit_log_end(ab); |
522ed776 MT |
1371 | break; |
1372 | } | |
1da177e4 LT |
1373 | default: |
1374 | err = -EINVAL; | |
1375 | break; | |
1376 | } | |
1377 | ||
1378 | return err < 0 ? err : 0; | |
1379 | } | |
1380 | ||
b0dd25a8 | 1381 | /* |
ea7ae60b EP |
1382 | * Get message from skb. Each message is processed by audit_receive_msg. |
1383 | * Malformed skbs with wrong length are discarded silently. | |
b0dd25a8 | 1384 | */ |
2a0a6ebe | 1385 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 | 1386 | { |
ea7ae60b EP |
1387 | struct nlmsghdr *nlh; |
1388 | /* | |
94191213 | 1389 | * len MUST be signed for nlmsg_next to be able to dec it below 0 |
ea7ae60b EP |
1390 | * if the nlmsg_len was not aligned |
1391 | */ | |
1392 | int len; | |
1393 | int err; | |
1394 | ||
1395 | nlh = nlmsg_hdr(skb); | |
1396 | len = skb->len; | |
1397 | ||
94191213 | 1398 | while (nlmsg_ok(nlh, len)) { |
ea7ae60b EP |
1399 | err = audit_receive_msg(skb, nlh); |
1400 | /* if err or if this message says it wants a response */ | |
1401 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
1da177e4 | 1402 | netlink_ack(skb, nlh, err); |
ea7ae60b | 1403 | |
2851da57 | 1404 | nlh = nlmsg_next(nlh, &len); |
1da177e4 | 1405 | } |
1da177e4 LT |
1406 | } |
1407 | ||
1408 | /* Receive messages from netlink socket. */ | |
cd40b7d3 | 1409 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 1410 | { |
f368c07d | 1411 | mutex_lock(&audit_cmd_mutex); |
cd40b7d3 | 1412 | audit_receive_skb(skb); |
f368c07d | 1413 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
1414 | } |
1415 | ||
3a101b8d | 1416 | /* Run custom bind function on netlink socket group connect or bind requests. */ |
023e2cfa | 1417 | static int audit_bind(struct net *net, int group) |
3a101b8d RGB |
1418 | { |
1419 | if (!capable(CAP_AUDIT_READ)) | |
1420 | return -EPERM; | |
1421 | ||
1422 | return 0; | |
1423 | } | |
1424 | ||
33faba7f | 1425 | static int __net_init audit_net_init(struct net *net) |
1da177e4 | 1426 | { |
a31f2d17 PNA |
1427 | struct netlink_kernel_cfg cfg = { |
1428 | .input = audit_receive, | |
3a101b8d | 1429 | .bind = audit_bind, |
451f9216 RGB |
1430 | .flags = NL_CFG_F_NONROOT_RECV, |
1431 | .groups = AUDIT_NLGRP_MAX, | |
a31f2d17 | 1432 | }; |
f368c07d | 1433 | |
33faba7f RGB |
1434 | struct audit_net *aunet = net_generic(net, audit_net_id); |
1435 | ||
5b52330b PM |
1436 | aunet->sk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg); |
1437 | if (aunet->sk == NULL) { | |
33faba7f | 1438 | audit_panic("cannot initialize netlink socket in namespace"); |
11ee39eb G |
1439 | return -ENOMEM; |
1440 | } | |
5b52330b PM |
1441 | aunet->sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; |
1442 | ||
33faba7f RGB |
1443 | return 0; |
1444 | } | |
1445 | ||
1446 | static void __net_exit audit_net_exit(struct net *net) | |
1447 | { | |
1448 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
5b52330b PM |
1449 | |
1450 | rcu_read_lock(); | |
1451 | if (net == auditd_conn.net) | |
c6480207 | 1452 | auditd_reset(); |
5b52330b | 1453 | rcu_read_unlock(); |
33faba7f | 1454 | |
5b52330b | 1455 | netlink_kernel_release(aunet->sk); |
33faba7f RGB |
1456 | } |
1457 | ||
8626877b | 1458 | static struct pernet_operations audit_net_ops __net_initdata = { |
33faba7f RGB |
1459 | .init = audit_net_init, |
1460 | .exit = audit_net_exit, | |
1461 | .id = &audit_net_id, | |
1462 | .size = sizeof(struct audit_net), | |
1463 | }; | |
1464 | ||
1465 | /* Initialize audit support at boot time. */ | |
1466 | static int __init audit_init(void) | |
1467 | { | |
1468 | int i; | |
1469 | ||
a3f07114 EP |
1470 | if (audit_initialized == AUDIT_DISABLED) |
1471 | return 0; | |
1472 | ||
5b52330b PM |
1473 | memset(&auditd_conn, 0, sizeof(auditd_conn)); |
1474 | spin_lock_init(&auditd_conn.lock); | |
1da177e4 | 1475 | |
af8b824f | 1476 | skb_queue_head_init(&audit_queue); |
c6480207 | 1477 | skb_queue_head_init(&audit_retry_queue); |
af8b824f | 1478 | skb_queue_head_init(&audit_hold_queue); |
3dc7e315 | 1479 | |
f368c07d AG |
1480 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
1481 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 1482 | |
5b52330b PM |
1483 | pr_info("initializing netlink subsys (%s)\n", |
1484 | audit_default ? "enabled" : "disabled"); | |
1485 | register_pernet_subsys(&audit_net_ops); | |
1486 | ||
1487 | audit_initialized = AUDIT_INITIALIZED; | |
1488 | audit_enabled = audit_default; | |
1489 | audit_ever_enabled |= !!audit_default; | |
1490 | ||
6c925564 PM |
1491 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
1492 | if (IS_ERR(kauditd_task)) { | |
1493 | int err = PTR_ERR(kauditd_task); | |
1494 | panic("audit: failed to start the kauditd thread (%d)\n", err); | |
1495 | } | |
1496 | ||
7c397d01 SG |
1497 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, |
1498 | "state=initialized audit_enabled=%u res=1", | |
1499 | audit_enabled); | |
6c925564 | 1500 | |
1da177e4 LT |
1501 | return 0; |
1502 | } | |
1da177e4 LT |
1503 | __initcall(audit_init); |
1504 | ||
1505 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
1506 | static int __init audit_enable(char *str) | |
1507 | { | |
1508 | audit_default = !!simple_strtol(str, NULL, 0); | |
a3f07114 EP |
1509 | if (!audit_default) |
1510 | audit_initialized = AUDIT_DISABLED; | |
1511 | ||
d957f7b7 | 1512 | pr_info("%s\n", audit_default ? |
d3ca0344 | 1513 | "enabled (after initialization)" : "disabled (until reboot)"); |
a3f07114 | 1514 | |
9b41046c | 1515 | return 1; |
1da177e4 | 1516 | } |
1da177e4 LT |
1517 | __setup("audit=", audit_enable); |
1518 | ||
f910fde7 RGB |
1519 | /* Process kernel command-line parameter at boot time. |
1520 | * audit_backlog_limit=<n> */ | |
1521 | static int __init audit_backlog_limit_set(char *str) | |
1522 | { | |
3e1d0bb6 | 1523 | u32 audit_backlog_limit_arg; |
d957f7b7 | 1524 | |
f910fde7 | 1525 | pr_info("audit_backlog_limit: "); |
3e1d0bb6 JP |
1526 | if (kstrtouint(str, 0, &audit_backlog_limit_arg)) { |
1527 | pr_cont("using default of %u, unable to parse %s\n", | |
d957f7b7 | 1528 | audit_backlog_limit, str); |
f910fde7 RGB |
1529 | return 1; |
1530 | } | |
3e1d0bb6 JP |
1531 | |
1532 | audit_backlog_limit = audit_backlog_limit_arg; | |
d957f7b7 | 1533 | pr_cont("%d\n", audit_backlog_limit); |
f910fde7 RGB |
1534 | |
1535 | return 1; | |
1536 | } | |
1537 | __setup("audit_backlog_limit=", audit_backlog_limit_set); | |
1538 | ||
16e1904e CW |
1539 | static void audit_buffer_free(struct audit_buffer *ab) |
1540 | { | |
1541 | unsigned long flags; | |
1542 | ||
8fc6115c CW |
1543 | if (!ab) |
1544 | return; | |
1545 | ||
d865e573 | 1546 | kfree_skb(ab->skb); |
16e1904e | 1547 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 1548 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 1549 | kfree(ab); |
5d136a01 SH |
1550 | else { |
1551 | audit_freelist_count++; | |
16e1904e | 1552 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 1553 | } |
16e1904e CW |
1554 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
1555 | } | |
1556 | ||
c0404993 | 1557 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 1558 | gfp_t gfp_mask, int type) |
16e1904e CW |
1559 | { |
1560 | unsigned long flags; | |
1561 | struct audit_buffer *ab = NULL; | |
c0404993 | 1562 | struct nlmsghdr *nlh; |
16e1904e CW |
1563 | |
1564 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
1565 | if (!list_empty(&audit_freelist)) { | |
1566 | ab = list_entry(audit_freelist.next, | |
1567 | struct audit_buffer, list); | |
1568 | list_del(&ab->list); | |
1569 | --audit_freelist_count; | |
1570 | } | |
1571 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
1572 | ||
1573 | if (!ab) { | |
4332bdd3 | 1574 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 1575 | if (!ab) |
8fc6115c | 1576 | goto err; |
16e1904e | 1577 | } |
8fc6115c | 1578 | |
b7d11258 | 1579 | ab->ctx = ctx; |
9ad9ad38 | 1580 | ab->gfp_mask = gfp_mask; |
ee080e6c EP |
1581 | |
1582 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1583 | if (!ab->skb) | |
c64e66c6 | 1584 | goto err; |
ee080e6c | 1585 | |
c64e66c6 DM |
1586 | nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); |
1587 | if (!nlh) | |
1588 | goto out_kfree_skb; | |
ee080e6c | 1589 | |
16e1904e | 1590 | return ab; |
ee080e6c | 1591 | |
c64e66c6 | 1592 | out_kfree_skb: |
ee080e6c EP |
1593 | kfree_skb(ab->skb); |
1594 | ab->skb = NULL; | |
8fc6115c CW |
1595 | err: |
1596 | audit_buffer_free(ab); | |
1597 | return NULL; | |
16e1904e | 1598 | } |
1da177e4 | 1599 | |
b0dd25a8 RD |
1600 | /** |
1601 | * audit_serial - compute a serial number for the audit record | |
1602 | * | |
1603 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1604 | * written to user-space as soon as they are generated, so a complete |
1605 | * audit record may be written in several pieces. The timestamp of the | |
1606 | * record and this serial number are used by the user-space tools to | |
1607 | * determine which pieces belong to the same audit record. The | |
1608 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1609 | * syscall entry to syscall exit. | |
1610 | * | |
bfb4496e DW |
1611 | * NOTE: Another possibility is to store the formatted records off the |
1612 | * audit context (for those records that have a context), and emit them | |
1613 | * all at syscall exit. However, this could delay the reporting of | |
1614 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1615 | * halts). |
1616 | */ | |
bfb4496e DW |
1617 | unsigned int audit_serial(void) |
1618 | { | |
01478d7d | 1619 | static atomic_t serial = ATOMIC_INIT(0); |
d5b454f2 | 1620 | |
01478d7d | 1621 | return atomic_add_return(1, &serial); |
bfb4496e DW |
1622 | } |
1623 | ||
5600b892 | 1624 | static inline void audit_get_stamp(struct audit_context *ctx, |
bfb4496e DW |
1625 | struct timespec *t, unsigned int *serial) |
1626 | { | |
48887e63 | 1627 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
bfb4496e DW |
1628 | *t = CURRENT_TIME; |
1629 | *serial = audit_serial(); | |
1630 | } | |
1631 | } | |
1632 | ||
b0dd25a8 RD |
1633 | /** |
1634 | * audit_log_start - obtain an audit buffer | |
1635 | * @ctx: audit_context (may be NULL) | |
1636 | * @gfp_mask: type of allocation | |
1637 | * @type: audit message type | |
1638 | * | |
1639 | * Returns audit_buffer pointer on success or NULL on error. | |
1640 | * | |
1641 | * Obtain an audit buffer. This routine does locking to obtain the | |
1642 | * audit buffer, but then no locking is required for calls to | |
1643 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1644 | * syscall, then the syscall is marked as auditable and an audit record | |
1645 | * will be written at syscall exit. If there is no associated task, then | |
1646 | * task context (ctx) should be NULL. | |
1647 | */ | |
9796fdd8 | 1648 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1649 | int type) |
1da177e4 | 1650 | { |
31975424 PM |
1651 | struct audit_buffer *ab; |
1652 | struct timespec t; | |
1653 | unsigned int uninitialized_var(serial); | |
1da177e4 | 1654 | |
a3f07114 | 1655 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1656 | return NULL; |
1657 | ||
86b2efbe | 1658 | if (unlikely(!audit_filter(type, AUDIT_FILTER_TYPE))) |
c8edc80c DK |
1659 | return NULL; |
1660 | ||
5b52330b | 1661 | /* NOTE: don't ever fail/sleep on these two conditions: |
a09cfa47 PM |
1662 | * 1. auditd generated record - since we need auditd to drain the |
1663 | * queue; also, when we are checking for auditd, compare PIDs using | |
1664 | * task_tgid_vnr() since auditd_pid is set in audit_receive_msg() | |
1665 | * using a PID anchored in the caller's namespace | |
5b52330b PM |
1666 | * 2. generator holding the audit_cmd_mutex - we don't want to block |
1667 | * while holding the mutex */ | |
1668 | if (!(auditd_test_task(current) || | |
1669 | (current == __mutex_owner(&audit_cmd_mutex)))) { | |
1670 | long stime = audit_backlog_wait_time; | |
31975424 PM |
1671 | |
1672 | while (audit_backlog_limit && | |
1673 | (skb_queue_len(&audit_queue) > audit_backlog_limit)) { | |
1674 | /* wake kauditd to try and flush the queue */ | |
1675 | wake_up_interruptible(&kauditd_wait); | |
9ad9ad38 | 1676 | |
31975424 PM |
1677 | /* sleep if we are allowed and we haven't exhausted our |
1678 | * backlog wait limit */ | |
5b52330b | 1679 | if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) { |
31975424 PM |
1680 | DECLARE_WAITQUEUE(wait, current); |
1681 | ||
1682 | add_wait_queue_exclusive(&audit_backlog_wait, | |
1683 | &wait); | |
1684 | set_current_state(TASK_UNINTERRUPTIBLE); | |
5b52330b | 1685 | stime = schedule_timeout(stime); |
31975424 PM |
1686 | remove_wait_queue(&audit_backlog_wait, &wait); |
1687 | } else { | |
1688 | if (audit_rate_check() && printk_ratelimit()) | |
1689 | pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n", | |
1690 | skb_queue_len(&audit_queue), | |
1691 | audit_backlog_limit); | |
1692 | audit_log_lost("backlog limit exceeded"); | |
1693 | return NULL; | |
8ac1c8d5 | 1694 | } |
9ad9ad38 | 1695 | } |
fb19b4c6 DW |
1696 | } |
1697 | ||
9ad9ad38 | 1698 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1699 | if (!ab) { |
1700 | audit_log_lost("out of memory in audit_log_start"); | |
1701 | return NULL; | |
1702 | } | |
1703 | ||
bfb4496e | 1704 | audit_get_stamp(ab->ctx, &t, &serial); |
1da177e4 LT |
1705 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
1706 | t.tv_sec, t.tv_nsec/1000000, serial); | |
31975424 | 1707 | |
1da177e4 LT |
1708 | return ab; |
1709 | } | |
1710 | ||
8fc6115c | 1711 | /** |
5ac52f33 | 1712 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1713 | * @ab: audit_buffer |
b0dd25a8 | 1714 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1715 | * |
1716 | * Returns 0 (no space) on failed expansion, or available space if | |
1717 | * successful. | |
1718 | */ | |
e3b926b4 | 1719 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1720 | { |
5ac52f33 | 1721 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1722 | int oldtail = skb_tailroom(skb); |
1723 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1724 | int newtail = skb_tailroom(skb); | |
1725 | ||
5ac52f33 CW |
1726 | if (ret < 0) { |
1727 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1728 | return 0; |
5ac52f33 | 1729 | } |
406a1d86 HX |
1730 | |
1731 | skb->truesize += newtail - oldtail; | |
1732 | return newtail; | |
8fc6115c | 1733 | } |
1da177e4 | 1734 | |
b0dd25a8 RD |
1735 | /* |
1736 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1737 | * room in the audit buffer, more room will be allocated and vsnprint |
1738 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1739 | * can't format message larger than 1024 bytes, so we don't either. |
1740 | */ | |
1da177e4 LT |
1741 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1742 | va_list args) | |
1743 | { | |
1744 | int len, avail; | |
5ac52f33 | 1745 | struct sk_buff *skb; |
eecb0a73 | 1746 | va_list args2; |
1da177e4 LT |
1747 | |
1748 | if (!ab) | |
1749 | return; | |
1750 | ||
5ac52f33 CW |
1751 | BUG_ON(!ab->skb); |
1752 | skb = ab->skb; | |
1753 | avail = skb_tailroom(skb); | |
1754 | if (avail == 0) { | |
e3b926b4 | 1755 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1756 | if (!avail) |
1757 | goto out; | |
1da177e4 | 1758 | } |
eecb0a73 | 1759 | va_copy(args2, args); |
27a884dc | 1760 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1761 | if (len >= avail) { |
1762 | /* The printk buffer is 1024 bytes long, so if we get | |
1763 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1764 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1765 | avail = audit_expand(ab, |
1766 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1767 | if (!avail) |
a0e86bd4 | 1768 | goto out_va_end; |
27a884dc | 1769 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1770 | } |
168b7173 SG |
1771 | if (len > 0) |
1772 | skb_put(skb, len); | |
a0e86bd4 JJ |
1773 | out_va_end: |
1774 | va_end(args2); | |
8fc6115c CW |
1775 | out: |
1776 | return; | |
1da177e4 LT |
1777 | } |
1778 | ||
b0dd25a8 RD |
1779 | /** |
1780 | * audit_log_format - format a message into the audit buffer. | |
1781 | * @ab: audit_buffer | |
1782 | * @fmt: format string | |
1783 | * @...: optional parameters matching @fmt string | |
1784 | * | |
1785 | * All the work is done in audit_log_vformat. | |
1786 | */ | |
1da177e4 LT |
1787 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1788 | { | |
1789 | va_list args; | |
1790 | ||
1791 | if (!ab) | |
1792 | return; | |
1793 | va_start(args, fmt); | |
1794 | audit_log_vformat(ab, fmt, args); | |
1795 | va_end(args); | |
1796 | } | |
1797 | ||
b0dd25a8 RD |
1798 | /** |
1799 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
1800 | * @ab: the audit_buffer | |
1801 | * @buf: buffer to convert to hex | |
1802 | * @len: length of @buf to be converted | |
1803 | * | |
1804 | * No return value; failure to expand is silently ignored. | |
1805 | * | |
1806 | * This function will take the passed buf and convert it into a string of | |
1807 | * ascii hex digits. The new string is placed onto the skb. | |
1808 | */ | |
b556f8ad | 1809 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1810 | size_t len) |
83c7d091 | 1811 | { |
168b7173 SG |
1812 | int i, avail, new_len; |
1813 | unsigned char *ptr; | |
1814 | struct sk_buff *skb; | |
168b7173 | 1815 | |
8ef2d304 AG |
1816 | if (!ab) |
1817 | return; | |
1818 | ||
168b7173 SG |
1819 | BUG_ON(!ab->skb); |
1820 | skb = ab->skb; | |
1821 | avail = skb_tailroom(skb); | |
1822 | new_len = len<<1; | |
1823 | if (new_len >= avail) { | |
1824 | /* Round the buffer request up to the next multiple */ | |
1825 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1826 | avail = audit_expand(ab, new_len); | |
1827 | if (!avail) | |
1828 | return; | |
1829 | } | |
83c7d091 | 1830 | |
27a884dc | 1831 | ptr = skb_tail_pointer(skb); |
b8dbc324 JP |
1832 | for (i = 0; i < len; i++) |
1833 | ptr = hex_byte_pack_upper(ptr, buf[i]); | |
168b7173 SG |
1834 | *ptr = 0; |
1835 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 DW |
1836 | } |
1837 | ||
9c937dcc AG |
1838 | /* |
1839 | * Format a string of no more than slen characters into the audit buffer, | |
1840 | * enclosed in quote marks. | |
1841 | */ | |
b556f8ad EP |
1842 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1843 | size_t slen) | |
9c937dcc AG |
1844 | { |
1845 | int avail, new_len; | |
1846 | unsigned char *ptr; | |
1847 | struct sk_buff *skb; | |
1848 | ||
8ef2d304 AG |
1849 | if (!ab) |
1850 | return; | |
1851 | ||
9c937dcc AG |
1852 | BUG_ON(!ab->skb); |
1853 | skb = ab->skb; | |
1854 | avail = skb_tailroom(skb); | |
1855 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1856 | if (new_len > avail) { | |
1857 | avail = audit_expand(ab, new_len); | |
1858 | if (!avail) | |
1859 | return; | |
1860 | } | |
27a884dc | 1861 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1862 | *ptr++ = '"'; |
1863 | memcpy(ptr, string, slen); | |
1864 | ptr += slen; | |
1865 | *ptr++ = '"'; | |
1866 | *ptr = 0; | |
1867 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1868 | } | |
1869 | ||
de6bbd1d EP |
1870 | /** |
1871 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1872 | * @string: string to be checked |
1873 | * @len: max length of the string to check | |
de6bbd1d | 1874 | */ |
9fcf836b | 1875 | bool audit_string_contains_control(const char *string, size_t len) |
de6bbd1d EP |
1876 | { |
1877 | const unsigned char *p; | |
b3897f56 | 1878 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1879 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
9fcf836b | 1880 | return true; |
de6bbd1d | 1881 | } |
9fcf836b | 1882 | return false; |
de6bbd1d EP |
1883 | } |
1884 | ||
b0dd25a8 | 1885 | /** |
522ed776 | 1886 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1887 | * @ab: audit_buffer |
f706d5d2 | 1888 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1889 | * @string: string to be logged |
1890 | * | |
1891 | * This code will escape a string that is passed to it if the string | |
1892 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1893 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1894 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1895 | * |
1896 | * The caller specifies the number of characters in the string to log, which may | |
1897 | * or may not be the entire string. | |
b0dd25a8 | 1898 | */ |
b556f8ad EP |
1899 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
1900 | size_t len) | |
83c7d091 | 1901 | { |
de6bbd1d | 1902 | if (audit_string_contains_control(string, len)) |
b556f8ad | 1903 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 1904 | else |
b556f8ad | 1905 | audit_log_n_string(ab, string, len); |
83c7d091 DW |
1906 | } |
1907 | ||
9c937dcc | 1908 | /** |
522ed776 | 1909 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
1910 | * @ab: audit_buffer |
1911 | * @string: string to be logged | |
1912 | * | |
522ed776 | 1913 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
1914 | * determine string length. |
1915 | */ | |
de6bbd1d | 1916 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 1917 | { |
b556f8ad | 1918 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
1919 | } |
1920 | ||
168b7173 | 1921 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 1922 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 1923 | const struct path *path) |
1da177e4 | 1924 | { |
44707fdf | 1925 | char *p, *pathname; |
1da177e4 | 1926 | |
8fc6115c | 1927 | if (prefix) |
c158a35c | 1928 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 1929 | |
168b7173 | 1930 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
1931 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
1932 | if (!pathname) { | |
def57543 | 1933 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 1934 | return; |
1da177e4 | 1935 | } |
cf28b486 | 1936 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
1937 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
1938 | /* FIXME: can we save some information here? */ | |
def57543 | 1939 | audit_log_string(ab, "<too_long>"); |
5600b892 | 1940 | } else |
168b7173 | 1941 | audit_log_untrustedstring(ab, p); |
44707fdf | 1942 | kfree(pathname); |
1da177e4 LT |
1943 | } |
1944 | ||
4d3fb709 EP |
1945 | void audit_log_session_info(struct audit_buffer *ab) |
1946 | { | |
4440e854 | 1947 | unsigned int sessionid = audit_get_sessionid(current); |
4d3fb709 EP |
1948 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); |
1949 | ||
b8f89caa | 1950 | audit_log_format(ab, " auid=%u ses=%u", auid, sessionid); |
4d3fb709 EP |
1951 | } |
1952 | ||
9d960985 EP |
1953 | void audit_log_key(struct audit_buffer *ab, char *key) |
1954 | { | |
1955 | audit_log_format(ab, " key="); | |
1956 | if (key) | |
1957 | audit_log_untrustedstring(ab, key); | |
1958 | else | |
1959 | audit_log_format(ab, "(null)"); | |
1960 | } | |
1961 | ||
b24a30a7 EP |
1962 | void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) |
1963 | { | |
1964 | int i; | |
1965 | ||
1966 | audit_log_format(ab, " %s=", prefix); | |
1967 | CAP_FOR_EACH_U32(i) { | |
1968 | audit_log_format(ab, "%08x", | |
7d8b6c63 | 1969 | cap->cap[CAP_LAST_U32 - i]); |
b24a30a7 EP |
1970 | } |
1971 | } | |
1972 | ||
691e6d59 | 1973 | static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) |
b24a30a7 EP |
1974 | { |
1975 | kernel_cap_t *perm = &name->fcap.permitted; | |
1976 | kernel_cap_t *inh = &name->fcap.inheritable; | |
1977 | int log = 0; | |
1978 | ||
1979 | if (!cap_isclear(*perm)) { | |
1980 | audit_log_cap(ab, "cap_fp", perm); | |
1981 | log = 1; | |
1982 | } | |
1983 | if (!cap_isclear(*inh)) { | |
1984 | audit_log_cap(ab, "cap_fi", inh); | |
1985 | log = 1; | |
1986 | } | |
1987 | ||
1988 | if (log) | |
1989 | audit_log_format(ab, " cap_fe=%d cap_fver=%x", | |
1990 | name->fcap.fE, name->fcap_ver); | |
1991 | } | |
1992 | ||
1993 | static inline int audit_copy_fcaps(struct audit_names *name, | |
1994 | const struct dentry *dentry) | |
1995 | { | |
1996 | struct cpu_vfs_cap_data caps; | |
1997 | int rc; | |
1998 | ||
1999 | if (!dentry) | |
2000 | return 0; | |
2001 | ||
2002 | rc = get_vfs_caps_from_disk(dentry, &caps); | |
2003 | if (rc) | |
2004 | return rc; | |
2005 | ||
2006 | name->fcap.permitted = caps.permitted; | |
2007 | name->fcap.inheritable = caps.inheritable; | |
2008 | name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); | |
2009 | name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> | |
2010 | VFS_CAP_REVISION_SHIFT; | |
2011 | ||
2012 | return 0; | |
2013 | } | |
2014 | ||
2015 | /* Copy inode data into an audit_names. */ | |
2016 | void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, | |
d6335d77 | 2017 | struct inode *inode) |
b24a30a7 EP |
2018 | { |
2019 | name->ino = inode->i_ino; | |
2020 | name->dev = inode->i_sb->s_dev; | |
2021 | name->mode = inode->i_mode; | |
2022 | name->uid = inode->i_uid; | |
2023 | name->gid = inode->i_gid; | |
2024 | name->rdev = inode->i_rdev; | |
2025 | security_inode_getsecid(inode, &name->osid); | |
2026 | audit_copy_fcaps(name, dentry); | |
2027 | } | |
2028 | ||
2029 | /** | |
2030 | * audit_log_name - produce AUDIT_PATH record from struct audit_names | |
2031 | * @context: audit_context for the task | |
2032 | * @n: audit_names structure with reportable details | |
2033 | * @path: optional path to report instead of audit_names->name | |
2034 | * @record_num: record number to report when handling a list of names | |
2035 | * @call_panic: optional pointer to int that will be updated if secid fails | |
2036 | */ | |
2037 | void audit_log_name(struct audit_context *context, struct audit_names *n, | |
8bd10763 | 2038 | const struct path *path, int record_num, int *call_panic) |
b24a30a7 EP |
2039 | { |
2040 | struct audit_buffer *ab; | |
2041 | ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); | |
2042 | if (!ab) | |
2043 | return; | |
2044 | ||
2045 | audit_log_format(ab, "item=%d", record_num); | |
2046 | ||
2047 | if (path) | |
2048 | audit_log_d_path(ab, " name=", path); | |
2049 | else if (n->name) { | |
2050 | switch (n->name_len) { | |
2051 | case AUDIT_NAME_FULL: | |
2052 | /* log the full path */ | |
2053 | audit_log_format(ab, " name="); | |
2054 | audit_log_untrustedstring(ab, n->name->name); | |
2055 | break; | |
2056 | case 0: | |
2057 | /* name was specified as a relative path and the | |
2058 | * directory component is the cwd */ | |
2059 | audit_log_d_path(ab, " name=", &context->pwd); | |
2060 | break; | |
2061 | default: | |
2062 | /* log the name's directory component */ | |
2063 | audit_log_format(ab, " name="); | |
2064 | audit_log_n_untrustedstring(ab, n->name->name, | |
2065 | n->name_len); | |
2066 | } | |
2067 | } else | |
2068 | audit_log_format(ab, " name=(null)"); | |
2069 | ||
425afcff | 2070 | if (n->ino != AUDIT_INO_UNSET) |
b24a30a7 EP |
2071 | audit_log_format(ab, " inode=%lu" |
2072 | " dev=%02x:%02x mode=%#ho" | |
2073 | " ouid=%u ogid=%u rdev=%02x:%02x", | |
2074 | n->ino, | |
2075 | MAJOR(n->dev), | |
2076 | MINOR(n->dev), | |
2077 | n->mode, | |
2078 | from_kuid(&init_user_ns, n->uid), | |
2079 | from_kgid(&init_user_ns, n->gid), | |
2080 | MAJOR(n->rdev), | |
2081 | MINOR(n->rdev)); | |
b24a30a7 EP |
2082 | if (n->osid != 0) { |
2083 | char *ctx = NULL; | |
2084 | u32 len; | |
2085 | if (security_secid_to_secctx( | |
2086 | n->osid, &ctx, &len)) { | |
2087 | audit_log_format(ab, " osid=%u", n->osid); | |
2088 | if (call_panic) | |
2089 | *call_panic = 2; | |
2090 | } else { | |
2091 | audit_log_format(ab, " obj=%s", ctx); | |
2092 | security_release_secctx(ctx, len); | |
2093 | } | |
2094 | } | |
2095 | ||
d3aea84a JL |
2096 | /* log the audit_names record type */ |
2097 | audit_log_format(ab, " nametype="); | |
2098 | switch(n->type) { | |
2099 | case AUDIT_TYPE_NORMAL: | |
2100 | audit_log_format(ab, "NORMAL"); | |
2101 | break; | |
2102 | case AUDIT_TYPE_PARENT: | |
2103 | audit_log_format(ab, "PARENT"); | |
2104 | break; | |
2105 | case AUDIT_TYPE_CHILD_DELETE: | |
2106 | audit_log_format(ab, "DELETE"); | |
2107 | break; | |
2108 | case AUDIT_TYPE_CHILD_CREATE: | |
2109 | audit_log_format(ab, "CREATE"); | |
2110 | break; | |
2111 | default: | |
2112 | audit_log_format(ab, "UNKNOWN"); | |
2113 | break; | |
2114 | } | |
2115 | ||
b24a30a7 EP |
2116 | audit_log_fcaps(ab, n); |
2117 | audit_log_end(ab); | |
2118 | } | |
2119 | ||
2120 | int audit_log_task_context(struct audit_buffer *ab) | |
2121 | { | |
2122 | char *ctx = NULL; | |
2123 | unsigned len; | |
2124 | int error; | |
2125 | u32 sid; | |
2126 | ||
2127 | security_task_getsecid(current, &sid); | |
2128 | if (!sid) | |
2129 | return 0; | |
2130 | ||
2131 | error = security_secid_to_secctx(sid, &ctx, &len); | |
2132 | if (error) { | |
2133 | if (error != -EINVAL) | |
2134 | goto error_path; | |
2135 | return 0; | |
2136 | } | |
2137 | ||
2138 | audit_log_format(ab, " subj=%s", ctx); | |
2139 | security_release_secctx(ctx, len); | |
2140 | return 0; | |
2141 | ||
2142 | error_path: | |
2143 | audit_panic("error in audit_log_task_context"); | |
2144 | return error; | |
2145 | } | |
2146 | EXPORT_SYMBOL(audit_log_task_context); | |
2147 | ||
4766b199 DB |
2148 | void audit_log_d_path_exe(struct audit_buffer *ab, |
2149 | struct mm_struct *mm) | |
2150 | { | |
5b282552 DB |
2151 | struct file *exe_file; |
2152 | ||
2153 | if (!mm) | |
2154 | goto out_null; | |
4766b199 | 2155 | |
5b282552 DB |
2156 | exe_file = get_mm_exe_file(mm); |
2157 | if (!exe_file) | |
2158 | goto out_null; | |
2159 | ||
2160 | audit_log_d_path(ab, " exe=", &exe_file->f_path); | |
2161 | fput(exe_file); | |
2162 | return; | |
2163 | out_null: | |
2164 | audit_log_format(ab, " exe=(null)"); | |
4766b199 DB |
2165 | } |
2166 | ||
3f5be2da RGB |
2167 | struct tty_struct *audit_get_tty(struct task_struct *tsk) |
2168 | { | |
2169 | struct tty_struct *tty = NULL; | |
2170 | unsigned long flags; | |
2171 | ||
2172 | spin_lock_irqsave(&tsk->sighand->siglock, flags); | |
2173 | if (tsk->signal) | |
2174 | tty = tty_kref_get(tsk->signal->tty); | |
2175 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); | |
2176 | return tty; | |
2177 | } | |
2178 | ||
2179 | void audit_put_tty(struct tty_struct *tty) | |
2180 | { | |
2181 | tty_kref_put(tty); | |
2182 | } | |
2183 | ||
b24a30a7 EP |
2184 | void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) |
2185 | { | |
2186 | const struct cred *cred; | |
9eab339b | 2187 | char comm[sizeof(tsk->comm)]; |
db0a6fb5 | 2188 | struct tty_struct *tty; |
b24a30a7 EP |
2189 | |
2190 | if (!ab) | |
2191 | return; | |
2192 | ||
2193 | /* tsk == current */ | |
2194 | cred = current_cred(); | |
db0a6fb5 | 2195 | tty = audit_get_tty(tsk); |
b24a30a7 | 2196 | audit_log_format(ab, |
c92cdeb4 | 2197 | " ppid=%d pid=%d auid=%u uid=%u gid=%u" |
b24a30a7 | 2198 | " euid=%u suid=%u fsuid=%u" |
2f2ad101 | 2199 | " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", |
c92cdeb4 | 2200 | task_ppid_nr(tsk), |
fa2bea2f | 2201 | task_tgid_nr(tsk), |
b24a30a7 EP |
2202 | from_kuid(&init_user_ns, audit_get_loginuid(tsk)), |
2203 | from_kuid(&init_user_ns, cred->uid), | |
2204 | from_kgid(&init_user_ns, cred->gid), | |
2205 | from_kuid(&init_user_ns, cred->euid), | |
2206 | from_kuid(&init_user_ns, cred->suid), | |
2207 | from_kuid(&init_user_ns, cred->fsuid), | |
2208 | from_kgid(&init_user_ns, cred->egid), | |
2209 | from_kgid(&init_user_ns, cred->sgid), | |
2210 | from_kgid(&init_user_ns, cred->fsgid), | |
db0a6fb5 RGB |
2211 | tty ? tty_name(tty) : "(none)", |
2212 | audit_get_sessionid(tsk)); | |
2213 | audit_put_tty(tty); | |
b24a30a7 | 2214 | audit_log_format(ab, " comm="); |
9eab339b | 2215 | audit_log_untrustedstring(ab, get_task_comm(comm, tsk)); |
4766b199 | 2216 | audit_log_d_path_exe(ab, tsk->mm); |
b24a30a7 EP |
2217 | audit_log_task_context(ab); |
2218 | } | |
2219 | EXPORT_SYMBOL(audit_log_task_info); | |
2220 | ||
a51d9eaa KC |
2221 | /** |
2222 | * audit_log_link_denied - report a link restriction denial | |
22011964 | 2223 | * @operation: specific link operation |
a51d9eaa KC |
2224 | * @link: the path that triggered the restriction |
2225 | */ | |
8bd10763 | 2226 | void audit_log_link_denied(const char *operation, const struct path *link) |
a51d9eaa KC |
2227 | { |
2228 | struct audit_buffer *ab; | |
b24a30a7 EP |
2229 | struct audit_names *name; |
2230 | ||
2231 | name = kzalloc(sizeof(*name), GFP_NOFS); | |
2232 | if (!name) | |
2233 | return; | |
a51d9eaa | 2234 | |
b24a30a7 | 2235 | /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ |
a51d9eaa KC |
2236 | ab = audit_log_start(current->audit_context, GFP_KERNEL, |
2237 | AUDIT_ANOM_LINK); | |
d1c7d97a | 2238 | if (!ab) |
b24a30a7 EP |
2239 | goto out; |
2240 | audit_log_format(ab, "op=%s", operation); | |
2241 | audit_log_task_info(ab, current); | |
2242 | audit_log_format(ab, " res=0"); | |
a51d9eaa | 2243 | audit_log_end(ab); |
b24a30a7 EP |
2244 | |
2245 | /* Generate AUDIT_PATH record with object. */ | |
2246 | name->type = AUDIT_TYPE_NORMAL; | |
3b362157 | 2247 | audit_copy_inode(name, link->dentry, d_backing_inode(link->dentry)); |
b24a30a7 EP |
2248 | audit_log_name(current->audit_context, name, link, 0, NULL); |
2249 | out: | |
2250 | kfree(name); | |
a51d9eaa KC |
2251 | } |
2252 | ||
b0dd25a8 RD |
2253 | /** |
2254 | * audit_log_end - end one audit record | |
2255 | * @ab: the audit_buffer | |
2256 | * | |
4aa83872 PM |
2257 | * We can not do a netlink send inside an irq context because it blocks (last |
2258 | * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a | |
2259 | * queue and a tasklet is scheduled to remove them from the queue outside the | |
2260 | * irq context. May be called in any context. | |
b0dd25a8 | 2261 | */ |
b7d11258 | 2262 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 2263 | { |
5b52330b PM |
2264 | struct sk_buff *skb; |
2265 | struct nlmsghdr *nlh; | |
2266 | ||
1da177e4 LT |
2267 | if (!ab) |
2268 | return; | |
5b52330b PM |
2269 | |
2270 | if (audit_rate_check()) { | |
2271 | skb = ab->skb; | |
f3d357b0 | 2272 | ab->skb = NULL; |
5b52330b PM |
2273 | |
2274 | /* setup the netlink header, see the comments in | |
2275 | * kauditd_send_multicast_skb() for length quirks */ | |
2276 | nlh = nlmsg_hdr(skb); | |
2277 | nlh->nlmsg_len = skb->len - NLMSG_HDRLEN; | |
2278 | ||
2279 | /* queue the netlink packet and poke the kauditd thread */ | |
2280 | skb_queue_tail(&audit_queue, skb); | |
2281 | wake_up_interruptible(&kauditd_wait); | |
2282 | } else | |
2283 | audit_log_lost("rate limit exceeded"); | |
2284 | ||
16e1904e | 2285 | audit_buffer_free(ab); |
1da177e4 LT |
2286 | } |
2287 | ||
b0dd25a8 RD |
2288 | /** |
2289 | * audit_log - Log an audit record | |
2290 | * @ctx: audit context | |
2291 | * @gfp_mask: type of allocation | |
2292 | * @type: audit message type | |
2293 | * @fmt: format string to use | |
2294 | * @...: variable parameters matching the format string | |
2295 | * | |
2296 | * This is a convenience function that calls audit_log_start, | |
2297 | * audit_log_vformat, and audit_log_end. It may be called | |
2298 | * in any context. | |
2299 | */ | |
5600b892 | 2300 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 2301 | const char *fmt, ...) |
1da177e4 LT |
2302 | { |
2303 | struct audit_buffer *ab; | |
2304 | va_list args; | |
2305 | ||
9ad9ad38 | 2306 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
2307 | if (ab) { |
2308 | va_start(args, fmt); | |
2309 | audit_log_vformat(ab, fmt, args); | |
2310 | va_end(args); | |
2311 | audit_log_end(ab); | |
2312 | } | |
2313 | } | |
bf45da97 | 2314 | |
131ad62d MDF |
2315 | #ifdef CONFIG_SECURITY |
2316 | /** | |
2317 | * audit_log_secctx - Converts and logs SELinux context | |
2318 | * @ab: audit_buffer | |
2319 | * @secid: security number | |
2320 | * | |
2321 | * This is a helper function that calls security_secid_to_secctx to convert | |
2322 | * secid to secctx and then adds the (converted) SELinux context to the audit | |
2323 | * log by calling audit_log_format, thus also preventing leak of internal secid | |
2324 | * to userspace. If secid cannot be converted audit_panic is called. | |
2325 | */ | |
2326 | void audit_log_secctx(struct audit_buffer *ab, u32 secid) | |
2327 | { | |
2328 | u32 len; | |
2329 | char *secctx; | |
2330 | ||
2331 | if (security_secid_to_secctx(secid, &secctx, &len)) { | |
2332 | audit_panic("Cannot convert secid to context"); | |
2333 | } else { | |
2334 | audit_log_format(ab, " obj=%s", secctx); | |
2335 | security_release_secctx(secctx, len); | |
2336 | } | |
2337 | } | |
2338 | EXPORT_SYMBOL(audit_log_secctx); | |
2339 | #endif | |
2340 | ||
bf45da97 | 2341 | EXPORT_SYMBOL(audit_log_start); |
2342 | EXPORT_SYMBOL(audit_log_end); | |
2343 | EXPORT_SYMBOL(audit_log_format); | |
2344 | EXPORT_SYMBOL(audit_log); |