1 /* auditsc.c -- System-call auditing support
2 * Handles all system-call specific auditing features.
3 *
4 * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
5 * Copyright 2005 Hewlett-Packard Development Company, L.P.
6 * Copyright (C) 2005, 2006 IBM Corporation
7 * All Rights Reserved.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 *
23 * Written by Rickard E. (Rik) Faith <faith@redhat.com>
24 *
25 * Many of the ideas implemented here are from Stephen C. Tweedie,
26 * especially the idea of avoiding a copy by using getname.
27 *
28 * The method for actual interception of syscall entry and exit (not in
29 * this file -- see entry.S) is based on a GPL'd patch written by
30 * okir@suse.de and Copyright 2003 SuSE Linux AG.
31 *
32 * POSIX message queue support added by George Wilson <ltcgcw@us.ibm.com>,
33 * 2006.
34 *
35 * The support of additional filter rules compares (>, <, >=, <=) was
36 * added by Dustin Kirkland <dustin.kirkland@us.ibm.com>, 2005.
37 *
38 * Modified by Amy Griffis <amy.griffis@hp.com> to collect additional
39 * filesystem information.
40 *
41 * Subject and object context labeling support added by <danjones@us.ibm.com>
42 * and <dustin.kirkland@us.ibm.com> for LSPP certification compliance.
43 */
44
45 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
46
47 #include <linux/init.h>
48 #include <asm/types.h>
49 #include <linux/atomic.h>
50 #include <linux/fs.h>
51 #include <linux/namei.h>
52 #include <linux/mm.h>
53 #include <linux/export.h>
54 #include <linux/slab.h>
55 #include <linux/mount.h>
56 #include <linux/socket.h>
57 #include <linux/mqueue.h>
58 #include <linux/audit.h>
59 #include <linux/personality.h>
60 #include <linux/time.h>
61 #include <linux/netlink.h>
62 #include <linux/compiler.h>
63 #include <asm/unistd.h>
64 #include <linux/security.h>
65 #include <linux/list.h>
66 #include <linux/tty.h>
67 #include <linux/binfmts.h>
68 #include <linux/highmem.h>
69 #include <linux/syscalls.h>
70 #include <asm/syscall.h>
71 #include <linux/capability.h>
72 #include <linux/fs_struct.h>
73 #include <linux/compat.h>
74 #include <linux/ctype.h>
75 #include <linux/string.h>
76 #include <linux/uaccess.h>
77 #include <uapi/linux/limits.h>
78
79 #include "audit.h"
80
81 /* flags stating the success for a syscall */
82 #define AUDITSC_INVALID 0
83 #define AUDITSC_SUCCESS 1
84 #define AUDITSC_FAILURE 2
85
86 /* no execve audit message should be longer than this (userspace limits),
87 * see the note near the top of audit_log_execve_info() about this value */
88 #define MAX_EXECVE_AUDIT_LEN 7500
89
90 /* max length to print of cmdline/proctitle value during audit */
91 #define MAX_PROCTITLE_AUDIT_LEN 128
92
93 /* number of audit rules */
94 int audit_n_rules;
95
96 /* determines whether we collect data for signals sent */
97 int audit_signals;
98
99 struct audit_aux_data {
100 struct audit_aux_data *next;
101 int type;
102 };
103
104 #define AUDIT_AUX_IPCPERM 0
105
106 /* Number of target pids per aux struct. */
107 #define AUDIT_AUX_PIDS 16
108
109 struct audit_aux_data_pids {
110 struct audit_aux_data d;
111 pid_t target_pid[AUDIT_AUX_PIDS];
112 kuid_t target_auid[AUDIT_AUX_PIDS];
113 kuid_t target_uid[AUDIT_AUX_PIDS];
114 unsigned int target_sessionid[AUDIT_AUX_PIDS];
115 u32 target_sid[AUDIT_AUX_PIDS];
116 char target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
117 int pid_count;
118 };
119
120 struct audit_aux_data_bprm_fcaps {
121 struct audit_aux_data d;
122 struct audit_cap_data fcap;
123 unsigned int fcap_ver;
124 struct audit_cap_data old_pcap;
125 struct audit_cap_data new_pcap;
126 };
127
128 struct audit_tree_refs {
129 struct audit_tree_refs *next;
130 struct audit_chunk *c[31];
131 };
132
audit_match_perm(struct audit_context * ctx,int mask)133 static int audit_match_perm(struct audit_context *ctx, int mask)
134 {
135 unsigned n;
136 if (unlikely(!ctx))
137 return 0;
138 n = ctx->major;
139
140 switch (audit_classify_syscall(ctx->arch, n)) {
141 case 0: /* native */
142 if ((mask & AUDIT_PERM_WRITE) &&
143 audit_match_class(AUDIT_CLASS_WRITE, n))
144 return 1;
145 if ((mask & AUDIT_PERM_READ) &&
146 audit_match_class(AUDIT_CLASS_READ, n))
147 return 1;
148 if ((mask & AUDIT_PERM_ATTR) &&
149 audit_match_class(AUDIT_CLASS_CHATTR, n))
150 return 1;
151 return 0;
152 case 1: /* 32bit on biarch */
153 if ((mask & AUDIT_PERM_WRITE) &&
154 audit_match_class(AUDIT_CLASS_WRITE_32, n))
155 return 1;
156 if ((mask & AUDIT_PERM_READ) &&
157 audit_match_class(AUDIT_CLASS_READ_32, n))
158 return 1;
159 if ((mask & AUDIT_PERM_ATTR) &&
160 audit_match_class(AUDIT_CLASS_CHATTR_32, n))
161 return 1;
162 return 0;
163 case 2: /* open */
164 return mask & ACC_MODE(ctx->argv[1]);
165 case 3: /* openat */
166 return mask & ACC_MODE(ctx->argv[2]);
167 case 4: /* socketcall */
168 return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND);
169 case 5: /* execve */
170 return mask & AUDIT_PERM_EXEC;
171 default:
172 return 0;
173 }
174 }
175
audit_match_filetype(struct audit_context * ctx,int val)176 static int audit_match_filetype(struct audit_context *ctx, int val)
177 {
178 struct audit_names *n;
179 umode_t mode = (umode_t)val;
180
181 if (unlikely(!ctx))
182 return 0;
183
184 list_for_each_entry(n, &ctx->names_list, list) {
185 if ((n->ino != AUDIT_INO_UNSET) &&
186 ((n->mode & S_IFMT) == mode))
187 return 1;
188 }
189
190 return 0;
191 }
192
193 /*
194 * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
195 * ->first_trees points to its beginning, ->trees - to the current end of data.
196 * ->tree_count is the number of free entries in array pointed to by ->trees.
197 * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
198 * "empty" becomes (p, p, 31) afterwards. We don't shrink the list (and seriously,
199 * it's going to remain 1-element for almost any setup) until we free context itself.
200 * References in it _are_ dropped - at the same time we free/drop aux stuff.
201 */
202
203 #ifdef CONFIG_AUDIT_TREE
audit_set_auditable(struct audit_context * ctx)204 static void audit_set_auditable(struct audit_context *ctx)
205 {
206 if (!ctx->prio) {
207 ctx->prio = 1;
208 ctx->current_state = AUDIT_RECORD_CONTEXT;
209 }
210 }
211
put_tree_ref(struct audit_context * ctx,struct audit_chunk * chunk)212 static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
213 {
214 struct audit_tree_refs *p = ctx->trees;
215 int left = ctx->tree_count;
216 if (likely(left)) {
217 p->c[--left] = chunk;
218 ctx->tree_count = left;
219 return 1;
220 }
221 if (!p)
222 return 0;
223 p = p->next;
224 if (p) {
225 p->c[30] = chunk;
226 ctx->trees = p;
227 ctx->tree_count = 30;
228 return 1;
229 }
230 return 0;
231 }
232
grow_tree_refs(struct audit_context * ctx)233 static int grow_tree_refs(struct audit_context *ctx)
234 {
235 struct audit_tree_refs *p = ctx->trees;
236 ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
237 if (!ctx->trees) {
238 ctx->trees = p;
239 return 0;
240 }
241 if (p)
242 p->next = ctx->trees;
243 else
244 ctx->first_trees = ctx->trees;
245 ctx->tree_count = 31;
246 return 1;
247 }
248 #endif
249
unroll_tree_refs(struct audit_context * ctx,struct audit_tree_refs * p,int count)250 static void unroll_tree_refs(struct audit_context *ctx,
251 struct audit_tree_refs *p, int count)
252 {
253 #ifdef CONFIG_AUDIT_TREE
254 struct audit_tree_refs *q;
255 int n;
256 if (!p) {
257 /* we started with empty chain */
258 p = ctx->first_trees;
259 count = 31;
260 /* if the very first allocation has failed, nothing to do */
261 if (!p)
262 return;
263 }
264 n = count;
265 for (q = p; q != ctx->trees; q = q->next, n = 31) {
266 while (n--) {
267 audit_put_chunk(q->c[n]);
268 q->c[n] = NULL;
269 }
270 }
271 while (n-- > ctx->tree_count) {
272 audit_put_chunk(q->c[n]);
273 q->c[n] = NULL;
274 }
275 ctx->trees = p;
276 ctx->tree_count = count;
277 #endif
278 }
279
free_tree_refs(struct audit_context * ctx)280 static void free_tree_refs(struct audit_context *ctx)
281 {
282 struct audit_tree_refs *p, *q;
283 for (p = ctx->first_trees; p; p = q) {
284 q = p->next;
285 kfree(p);
286 }
287 }
288
match_tree_refs(struct audit_context * ctx,struct audit_tree * tree)289 static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
290 {
291 #ifdef CONFIG_AUDIT_TREE
292 struct audit_tree_refs *p;
293 int n;
294 if (!tree)
295 return 0;
296 /* full ones */
297 for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
298 for (n = 0; n < 31; n++)
299 if (audit_tree_match(p->c[n], tree))
300 return 1;
301 }
302 /* partial */
303 if (p) {
304 for (n = ctx->tree_count; n < 31; n++)
305 if (audit_tree_match(p->c[n], tree))
306 return 1;
307 }
308 #endif
309 return 0;
310 }
311
audit_compare_uid(kuid_t uid,struct audit_names * name,struct audit_field * f,struct audit_context * ctx)312 static int audit_compare_uid(kuid_t uid,
313 struct audit_names *name,
314 struct audit_field *f,
315 struct audit_context *ctx)
316 {
317 struct audit_names *n;
318 int rc;
319
320 if (name) {
321 rc = audit_uid_comparator(uid, f->op, name->uid);
322 if (rc)
323 return rc;
324 }
325
326 if (ctx) {
327 list_for_each_entry(n, &ctx->names_list, list) {
328 rc = audit_uid_comparator(uid, f->op, n->uid);
329 if (rc)
330 return rc;
331 }
332 }
333 return 0;
334 }
335
audit_compare_gid(kgid_t gid,struct audit_names * name,struct audit_field * f,struct audit_context * ctx)336 static int audit_compare_gid(kgid_t gid,
337 struct audit_names *name,
338 struct audit_field *f,
339 struct audit_context *ctx)
340 {
341 struct audit_names *n;
342 int rc;
343
344 if (name) {
345 rc = audit_gid_comparator(gid, f->op, name->gid);
346 if (rc)
347 return rc;
348 }
349
350 if (ctx) {
351 list_for_each_entry(n, &ctx->names_list, list) {
352 rc = audit_gid_comparator(gid, f->op, n->gid);
353 if (rc)
354 return rc;
355 }
356 }
357 return 0;
358 }
359
audit_field_compare(struct task_struct * tsk,const struct cred * cred,struct audit_field * f,struct audit_context * ctx,struct audit_names * name)360 static int audit_field_compare(struct task_struct *tsk,
361 const struct cred *cred,
362 struct audit_field *f,
363 struct audit_context *ctx,
364 struct audit_names *name)
365 {
366 switch (f->val) {
367 /* process to file object comparisons */
368 case AUDIT_COMPARE_UID_TO_OBJ_UID:
369 return audit_compare_uid(cred->uid, name, f, ctx);
370 case AUDIT_COMPARE_GID_TO_OBJ_GID:
371 return audit_compare_gid(cred->gid, name, f, ctx);
372 case AUDIT_COMPARE_EUID_TO_OBJ_UID:
373 return audit_compare_uid(cred->euid, name, f, ctx);
374 case AUDIT_COMPARE_EGID_TO_OBJ_GID:
375 return audit_compare_gid(cred->egid, name, f, ctx);
376 case AUDIT_COMPARE_AUID_TO_OBJ_UID:
377 return audit_compare_uid(tsk->loginuid, name, f, ctx);
378 case AUDIT_COMPARE_SUID_TO_OBJ_UID:
379 return audit_compare_uid(cred->suid, name, f, ctx);
380 case AUDIT_COMPARE_SGID_TO_OBJ_GID:
381 return audit_compare_gid(cred->sgid, name, f, ctx);
382 case AUDIT_COMPARE_FSUID_TO_OBJ_UID:
383 return audit_compare_uid(cred->fsuid, name, f, ctx);
384 case AUDIT_COMPARE_FSGID_TO_OBJ_GID:
385 return audit_compare_gid(cred->fsgid, name, f, ctx);
386 /* uid comparisons */
387 case AUDIT_COMPARE_UID_TO_AUID:
388 return audit_uid_comparator(cred->uid, f->op, tsk->loginuid);
389 case AUDIT_COMPARE_UID_TO_EUID:
390 return audit_uid_comparator(cred->uid, f->op, cred->euid);
391 case AUDIT_COMPARE_UID_TO_SUID:
392 return audit_uid_comparator(cred->uid, f->op, cred->suid);
393 case AUDIT_COMPARE_UID_TO_FSUID:
394 return audit_uid_comparator(cred->uid, f->op, cred->fsuid);
395 /* auid comparisons */
396 case AUDIT_COMPARE_AUID_TO_EUID:
397 return audit_uid_comparator(tsk->loginuid, f->op, cred->euid);
398 case AUDIT_COMPARE_AUID_TO_SUID:
399 return audit_uid_comparator(tsk->loginuid, f->op, cred->suid);
400 case AUDIT_COMPARE_AUID_TO_FSUID:
401 return audit_uid_comparator(tsk->loginuid, f->op, cred->fsuid);
402 /* euid comparisons */
403 case AUDIT_COMPARE_EUID_TO_SUID:
404 return audit_uid_comparator(cred->euid, f->op, cred->suid);
405 case AUDIT_COMPARE_EUID_TO_FSUID:
406 return audit_uid_comparator(cred->euid, f->op, cred->fsuid);
407 /* suid comparisons */
408 case AUDIT_COMPARE_SUID_TO_FSUID:
409 return audit_uid_comparator(cred->suid, f->op, cred->fsuid);
410 /* gid comparisons */
411 case AUDIT_COMPARE_GID_TO_EGID:
412 return audit_gid_comparator(cred->gid, f->op, cred->egid);
413 case AUDIT_COMPARE_GID_TO_SGID:
414 return audit_gid_comparator(cred->gid, f->op, cred->sgid);
415 case AUDIT_COMPARE_GID_TO_FSGID:
416 return audit_gid_comparator(cred->gid, f->op, cred->fsgid);
417 /* egid comparisons */
418 case AUDIT_COMPARE_EGID_TO_SGID:
419 return audit_gid_comparator(cred->egid, f->op, cred->sgid);
420 case AUDIT_COMPARE_EGID_TO_FSGID:
421 return audit_gid_comparator(cred->egid, f->op, cred->fsgid);
422 /* sgid comparison */
423 case AUDIT_COMPARE_SGID_TO_FSGID:
424 return audit_gid_comparator(cred->sgid, f->op, cred->fsgid);
425 default:
426 WARN(1, "Missing AUDIT_COMPARE define. Report as a bug\n");
427 return 0;
428 }
429 return 0;
430 }
431
432 /* Determine if any context name data matches a rule's watch data */
433 /* Compare a task_struct with an audit_rule. Return 1 on match, 0
434 * otherwise.
435 *
436 * If task_creation is true, this is an explicit indication that we are
437 * filtering a task rule at task creation time. This and tsk == current are
438 * the only situations where tsk->cred may be accessed without an rcu read lock.
439 */
audit_filter_rules(struct task_struct * tsk,struct audit_krule * rule,struct audit_context * ctx,struct audit_names * name,enum audit_state * state,bool task_creation)440 static int audit_filter_rules(struct task_struct *tsk,
441 struct audit_krule *rule,
442 struct audit_context *ctx,
443 struct audit_names *name,
444 enum audit_state *state,
445 bool task_creation)
446 {
447 const struct cred *cred;
448 int i, need_sid = 1;
449 u32 sid;
450
451 cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
452
453 for (i = 0; i < rule->field_count; i++) {
454 struct audit_field *f = &rule->fields[i];
455 struct audit_names *n;
456 int result = 0;
457 pid_t pid;
458
459 switch (f->type) {
460 case AUDIT_PID:
461 pid = task_tgid_nr(tsk);
462 result = audit_comparator(pid, f->op, f->val);
463 break;
464 case AUDIT_PPID:
465 if (ctx) {
466 if (!ctx->ppid)
467 ctx->ppid = task_ppid_nr(tsk);
468 result = audit_comparator(ctx->ppid, f->op, f->val);
469 }
470 break;
471 case AUDIT_EXE:
472 result = audit_exe_compare(tsk, rule->exe);
473 if (f->op == Audit_not_equal)
474 result = !result;
475 break;
476 case AUDIT_UID:
477 result = audit_uid_comparator(cred->uid, f->op, f->uid);
478 break;
479 case AUDIT_EUID:
480 result = audit_uid_comparator(cred->euid, f->op, f->uid);
481 break;
482 case AUDIT_SUID:
483 result = audit_uid_comparator(cred->suid, f->op, f->uid);
484 break;
485 case AUDIT_FSUID:
486 result = audit_uid_comparator(cred->fsuid, f->op, f->uid);
487 break;
488 case AUDIT_GID:
489 result = audit_gid_comparator(cred->gid, f->op, f->gid);
490 if (f->op == Audit_equal) {
491 if (!result)
492 result = in_group_p(f->gid);
493 } else if (f->op == Audit_not_equal) {
494 if (result)
495 result = !in_group_p(f->gid);
496 }
497 break;
498 case AUDIT_EGID:
499 result = audit_gid_comparator(cred->egid, f->op, f->gid);
500 if (f->op == Audit_equal) {
501 if (!result)
502 result = in_egroup_p(f->gid);
503 } else if (f->op == Audit_not_equal) {
504 if (result)
505 result = !in_egroup_p(f->gid);
506 }
507 break;
508 case AUDIT_SGID:
509 result = audit_gid_comparator(cred->sgid, f->op, f->gid);
510 break;
511 case AUDIT_FSGID:
512 result = audit_gid_comparator(cred->fsgid, f->op, f->gid);
513 break;
514 case AUDIT_PERS:
515 result = audit_comparator(tsk->personality, f->op, f->val);
516 break;
517 case AUDIT_ARCH:
518 if (ctx)
519 result = audit_comparator(ctx->arch, f->op, f->val);
520 break;
521
522 case AUDIT_EXIT:
523 if (ctx && ctx->return_valid)
524 result = audit_comparator(ctx->return_code, f->op, f->val);
525 break;
526 case AUDIT_SUCCESS:
527 if (ctx && ctx->return_valid) {
528 if (f->val)
529 result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
530 else
531 result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);
532 }
533 break;
534 case AUDIT_DEVMAJOR:
535 if (name) {
536 if (audit_comparator(MAJOR(name->dev), f->op, f->val) ||
537 audit_comparator(MAJOR(name->rdev), f->op, f->val))
538 ++result;
539 } else if (ctx) {
540 list_for_each_entry(n, &ctx->names_list, list) {
541 if (audit_comparator(MAJOR(n->dev), f->op, f->val) ||
542 audit_comparator(MAJOR(n->rdev), f->op, f->val)) {
543 ++result;
544 break;
545 }
546 }
547 }
548 break;
549 case AUDIT_DEVMINOR:
550 if (name) {
551 if (audit_comparator(MINOR(name->dev), f->op, f->val) ||
552 audit_comparator(MINOR(name->rdev), f->op, f->val))
553 ++result;
554 } else if (ctx) {
555 list_for_each_entry(n, &ctx->names_list, list) {
556 if (audit_comparator(MINOR(n->dev), f->op, f->val) ||
557 audit_comparator(MINOR(n->rdev), f->op, f->val)) {
558 ++result;
559 break;
560 }
561 }
562 }
563 break;
564 case AUDIT_INODE:
565 if (name)
566 result = audit_comparator(name->ino, f->op, f->val);
567 else if (ctx) {
568 list_for_each_entry(n, &ctx->names_list, list) {
569 if (audit_comparator(n->ino, f->op, f->val)) {
570 ++result;
571 break;
572 }
573 }
574 }
575 break;
576 case AUDIT_OBJ_UID:
577 if (name) {
578 result = audit_uid_comparator(name->uid, f->op, f->uid);
579 } else if (ctx) {
580 list_for_each_entry(n, &ctx->names_list, list) {
581 if (audit_uid_comparator(n->uid, f->op, f->uid)) {
582 ++result;
583 break;
584 }
585 }
586 }
587 break;
588 case AUDIT_OBJ_GID:
589 if (name) {
590 result = audit_gid_comparator(name->gid, f->op, f->gid);
591 } else if (ctx) {
592 list_for_each_entry(n, &ctx->names_list, list) {
593 if (audit_gid_comparator(n->gid, f->op, f->gid)) {
594 ++result;
595 break;
596 }
597 }
598 }
599 break;
600 case AUDIT_WATCH:
601 if (name)
602 result = audit_watch_compare(rule->watch, name->ino, name->dev);
603 break;
604 case AUDIT_DIR:
605 if (ctx)
606 result = match_tree_refs(ctx, rule->tree);
607 break;
608 case AUDIT_LOGINUID:
609 result = audit_uid_comparator(tsk->loginuid, f->op, f->uid);
610 break;
611 case AUDIT_LOGINUID_SET:
612 result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
613 break;
614 case AUDIT_SUBJ_USER:
615 case AUDIT_SUBJ_ROLE:
616 case AUDIT_SUBJ_TYPE:
617 case AUDIT_SUBJ_SEN:
618 case AUDIT_SUBJ_CLR:
619 /* NOTE: this may return negative values indicating
620 a temporary error. We simply treat this as a
621 match for now to avoid losing information that
622 may be wanted. An error message will also be
623 logged upon error */
624 if (f->lsm_rule) {
625 if (need_sid) {
626 security_task_getsecid(tsk, &sid);
627 need_sid = 0;
628 }
629 result = security_audit_rule_match(sid, f->type,
630 f->op,
631 f->lsm_rule,
632 ctx);
633 }
634 break;
635 case AUDIT_OBJ_USER:
636 case AUDIT_OBJ_ROLE:
637 case AUDIT_OBJ_TYPE:
638 case AUDIT_OBJ_LEV_LOW:
639 case AUDIT_OBJ_LEV_HIGH:
640 /* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
641 also applies here */
642 if (f->lsm_rule) {
643 /* Find files that match */
644 if (name) {
645 result = security_audit_rule_match(
646 name->osid, f->type, f->op,
647 f->lsm_rule, ctx);
648 } else if (ctx) {
649 list_for_each_entry(n, &ctx->names_list, list) {
650 if (security_audit_rule_match(n->osid, f->type,
651 f->op, f->lsm_rule,
652 ctx)) {
653 ++result;
654 break;
655 }
656 }
657 }
658 /* Find ipc objects that match */
659 if (!ctx || ctx->type != AUDIT_IPC)
660 break;
661 if (security_audit_rule_match(ctx->ipc.osid,
662 f->type, f->op,
663 f->lsm_rule, ctx))
664 ++result;
665 }
666 break;
667 case AUDIT_ARG0:
668 case AUDIT_ARG1:
669 case AUDIT_ARG2:
670 case AUDIT_ARG3:
671 if (ctx)
672 result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
673 break;
674 case AUDIT_FILTERKEY:
675 /* ignore this field for filtering */
676 result = 1;
677 break;
678 case AUDIT_PERM:
679 result = audit_match_perm(ctx, f->val);
680 break;
681 case AUDIT_FILETYPE:
682 result = audit_match_filetype(ctx, f->val);
683 break;
684 case AUDIT_FIELD_COMPARE:
685 result = audit_field_compare(tsk, cred, f, ctx, name);
686 break;
687 }
688 if (!result)
689 return 0;
690 }
691
692 if (ctx) {
693 if (rule->prio <= ctx->prio)
694 return 0;
695 if (rule->filterkey) {
696 kfree(ctx->filterkey);
697 ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
698 }
699 ctx->prio = rule->prio;
700 }
701 switch (rule->action) {
702 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
703 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
704 }
705 return 1;
706 }
707
708 /* At process creation time, we can determine if system-call auditing is
709 * completely disabled for this task. Since we only have the task
710 * structure at this point, we can only check uid and gid.
711 */
audit_filter_task(struct task_struct * tsk,char ** key)712 static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
713 {
714 struct audit_entry *e;
715 enum audit_state state;
716
717 rcu_read_lock();
718 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
719 if (audit_filter_rules(tsk, &e->rule, NULL, NULL,
720 &state, true)) {
721 if (state == AUDIT_RECORD_CONTEXT)
722 *key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
723 rcu_read_unlock();
724 return state;
725 }
726 }
727 rcu_read_unlock();
728 return AUDIT_BUILD_CONTEXT;
729 }
730
audit_in_mask(const struct audit_krule * rule,unsigned long val)731 static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
732 {
733 int word, bit;
734
735 if (val > 0xffffffff)
736 return false;
737
738 word = AUDIT_WORD(val);
739 if (word >= AUDIT_BITMASK_SIZE)
740 return false;
741
742 bit = AUDIT_BIT(val);
743
744 return rule->mask[word] & bit;
745 }
746
747 /* At syscall entry and exit time, this filter is called if the
748 * audit_state is not low enough that auditing cannot take place, but is
749 * also not high enough that we already know we have to write an audit
750 * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
751 */
audit_filter_syscall(struct task_struct * tsk,struct audit_context * ctx,struct list_head * list)752 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
753 struct audit_context *ctx,
754 struct list_head *list)
755 {
756 struct audit_entry *e;
757 enum audit_state state;
758
759 if (audit_pid && tsk->tgid == audit_pid)
760 return AUDIT_DISABLED;
761
762 rcu_read_lock();
763 if (!list_empty(list)) {
764 list_for_each_entry_rcu(e, list, list) {
765 if (audit_in_mask(&e->rule, ctx->major) &&
766 audit_filter_rules(tsk, &e->rule, ctx, NULL,
767 &state, false)) {
768 rcu_read_unlock();
769 ctx->current_state = state;
770 return state;
771 }
772 }
773 }
774 rcu_read_unlock();
775 return AUDIT_BUILD_CONTEXT;
776 }
777
778 /*
779 * Given an audit_name check the inode hash table to see if they match.
780 * Called holding the rcu read lock to protect the use of audit_inode_hash
781 */
audit_filter_inode_name(struct task_struct * tsk,struct audit_names * n,struct audit_context * ctx)782 static int audit_filter_inode_name(struct task_struct *tsk,
783 struct audit_names *n,
784 struct audit_context *ctx) {
785 int h = audit_hash_ino((u32)n->ino);
786 struct list_head *list = &audit_inode_hash[h];
787 struct audit_entry *e;
788 enum audit_state state;
789
790 if (list_empty(list))
791 return 0;
792
793 list_for_each_entry_rcu(e, list, list) {
794 if (audit_in_mask(&e->rule, ctx->major) &&
795 audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {
796 ctx->current_state = state;
797 return 1;
798 }
799 }
800
801 return 0;
802 }
803
804 /* At syscall exit time, this filter is called if any audit_names have been
805 * collected during syscall processing. We only check rules in sublists at hash
806 * buckets applicable to the inode numbers in audit_names.
807 * Regarding audit_state, same rules apply as for audit_filter_syscall().
808 */
audit_filter_inodes(struct task_struct * tsk,struct audit_context * ctx)809 void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
810 {
811 struct audit_names *n;
812
813 if (audit_pid && tsk->tgid == audit_pid)
814 return;
815
816 rcu_read_lock();
817
818 list_for_each_entry(n, &ctx->names_list, list) {
819 if (audit_filter_inode_name(tsk, n, ctx))
820 break;
821 }
822 rcu_read_unlock();
823 }
824
825 /* Transfer the audit context pointer to the caller, clearing it in the tsk's struct */
audit_take_context(struct task_struct * tsk,int return_valid,long return_code)826 static inline struct audit_context *audit_take_context(struct task_struct *tsk,
827 int return_valid,
828 long return_code)
829 {
830 struct audit_context *context = tsk->audit_context;
831
832 if (!context)
833 return NULL;
834 context->return_valid = return_valid;
835
836 /*
837 * we need to fix up the return code in the audit logs if the actual
838 * return codes are later going to be fixed up by the arch specific
839 * signal handlers
840 *
841 * This is actually a test for:
842 * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) ||
843 * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK)
844 *
845 * but is faster than a bunch of ||
846 */
847 if (unlikely(return_code <= -ERESTARTSYS) &&
848 (return_code >= -ERESTART_RESTARTBLOCK) &&
849 (return_code != -ENOIOCTLCMD))
850 context->return_code = -EINTR;
851 else
852 context->return_code = return_code;
853
854 if (context->in_syscall && !context->dummy) {
855 audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
856 audit_filter_inodes(tsk, context);
857 }
858
859 tsk->audit_context = NULL;
860 return context;
861 }
862
audit_proctitle_free(struct audit_context * context)863 static inline void audit_proctitle_free(struct audit_context *context)
864 {
865 kfree(context->proctitle.value);
866 context->proctitle.value = NULL;
867 context->proctitle.len = 0;
868 }
869
audit_free_names(struct audit_context * context)870 static inline void audit_free_names(struct audit_context *context)
871 {
872 struct audit_names *n, *next;
873
874 list_for_each_entry_safe(n, next, &context->names_list, list) {
875 list_del(&n->list);
876 if (n->name)
877 putname(n->name);
878 if (n->should_free)
879 kfree(n);
880 }
881 context->name_count = 0;
882 path_put(&context->pwd);
883 context->pwd.dentry = NULL;
884 context->pwd.mnt = NULL;
885 }
886
audit_free_aux(struct audit_context * context)887 static inline void audit_free_aux(struct audit_context *context)
888 {
889 struct audit_aux_data *aux;
890
891 while ((aux = context->aux)) {
892 context->aux = aux->next;
893 kfree(aux);
894 }
895 while ((aux = context->aux_pids)) {
896 context->aux_pids = aux->next;
897 kfree(aux);
898 }
899 }
900
audit_alloc_context(enum audit_state state)901 static inline struct audit_context *audit_alloc_context(enum audit_state state)
902 {
903 struct audit_context *context;
904
905 context = kzalloc(sizeof(*context), GFP_KERNEL);
906 if (!context)
907 return NULL;
908 context->state = state;
909 context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
910 INIT_LIST_HEAD(&context->killed_trees);
911 INIT_LIST_HEAD(&context->names_list);
912 return context;
913 }
914
915 /**
916 * audit_alloc - allocate an audit context block for a task
917 * @tsk: task
918 *
919 * Filter on the task information and allocate a per-task audit context
920 * if necessary. Doing so turns on system call auditing for the
921 * specified task. This is called from copy_process, so no lock is
922 * needed.
923 */
audit_alloc(struct task_struct * tsk)924 int audit_alloc(struct task_struct *tsk)
925 {
926 struct audit_context *context;
927 enum audit_state state;
928 char *key = NULL;
929
930 if (likely(!audit_ever_enabled))
931 return 0; /* Return if not auditing. */
932
933 state = audit_filter_task(tsk, &key);
934 if (state == AUDIT_DISABLED) {
935 clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
936 return 0;
937 }
938
939 if (!(context = audit_alloc_context(state))) {
940 kfree(key);
941 audit_log_lost("out of memory in audit_alloc");
942 return -ENOMEM;
943 }
944 context->filterkey = key;
945
946 tsk->audit_context = context;
947 set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
948 return 0;
949 }
950
audit_free_context(struct audit_context * context)951 static inline void audit_free_context(struct audit_context *context)
952 {
953 audit_free_names(context);
954 unroll_tree_refs(context, NULL, 0);
955 free_tree_refs(context);
956 audit_free_aux(context);
957 kfree(context->filterkey);
958 kfree(context->sockaddr);
959 audit_proctitle_free(context);
960 kfree(context);
961 }
962
audit_log_pid_context(struct audit_context * context,pid_t pid,kuid_t auid,kuid_t uid,unsigned int sessionid,u32 sid,char * comm)963 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
964 kuid_t auid, kuid_t uid, unsigned int sessionid,
965 u32 sid, char *comm)
966 {
967 struct audit_buffer *ab;
968 char *ctx = NULL;
969 u32 len;
970 int rc = 0;
971
972 ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
973 if (!ab)
974 return rc;
975
976 audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
977 from_kuid(&init_user_ns, auid),
978 from_kuid(&init_user_ns, uid), sessionid);
979 if (sid) {
980 if (security_secid_to_secctx(sid, &ctx, &len)) {
981 audit_log_format(ab, " obj=(none)");
982 rc = 1;
983 } else {
984 audit_log_format(ab, " obj=%s", ctx);
985 security_release_secctx(ctx, len);
986 }
987 }
988 audit_log_format(ab, " ocomm=");
989 audit_log_untrustedstring(ab, comm);
990 audit_log_end(ab);
991
992 return rc;
993 }
994
audit_log_execve_info(struct audit_context * context,struct audit_buffer ** ab)995 static void audit_log_execve_info(struct audit_context *context,
996 struct audit_buffer **ab)
997 {
998 long len_max;
999 long len_rem;
1000 long len_full;
1001 long len_buf;
1002 long len_abuf;
1003 long len_tmp;
1004 bool require_data;
1005 bool encode;
1006 unsigned int iter;
1007 unsigned int arg;
1008 char *buf_head;
1009 char *buf;
1010 const char __user *p = (const char __user *)current->mm->arg_start;
1011
1012 /* NOTE: this buffer needs to be large enough to hold all the non-arg
1013 * data we put in the audit record for this argument (see the
1014 * code below) ... at this point in time 96 is plenty */
1015 char abuf[96];
1016
1017 /* NOTE: we set MAX_EXECVE_AUDIT_LEN to a rather arbitrary limit, the
1018 * current value of 7500 is not as important as the fact that it
1019 * is less than 8k, a setting of 7500 gives us plenty of wiggle
1020 * room if we go over a little bit in the logging below */
1021 WARN_ON_ONCE(MAX_EXECVE_AUDIT_LEN > 7500);
1022 len_max = MAX_EXECVE_AUDIT_LEN;
1023
1024 /* scratch buffer to hold the userspace args */
1025 buf_head = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL);
1026 if (!buf_head) {
1027 audit_panic("out of memory for argv string");
1028 return;
1029 }
1030 buf = buf_head;
1031
1032 audit_log_format(*ab, "argc=%d", context->execve.argc);
1033
1034 len_rem = len_max;
1035 len_buf = 0;
1036 len_full = 0;
1037 require_data = true;
1038 encode = false;
1039 iter = 0;
1040 arg = 0;
1041 do {
1042 /* NOTE: we don't ever want to trust this value for anything
1043 * serious, but the audit record format insists we
1044 * provide an argument length for really long arguments,
1045 * e.g. > MAX_EXECVE_AUDIT_LEN, so we have no choice but
1046 * to use strncpy_from_user() to obtain this value for
1047 * recording in the log, although we don't use it
1048 * anywhere here to avoid a double-fetch problem */
1049 if (len_full == 0)
1050 len_full = strnlen_user(p, MAX_ARG_STRLEN) - 1;
1051
1052 /* read more data from userspace */
1053 if (require_data) {
1054 /* can we make more room in the buffer? */
1055 if (buf != buf_head) {
1056 memmove(buf_head, buf, len_buf);
1057 buf = buf_head;
1058 }
1059
1060 /* fetch as much as we can of the argument */
1061 len_tmp = strncpy_from_user(&buf_head[len_buf], p,
1062 len_max - len_buf);
1063 if (len_tmp == -EFAULT) {
1064 /* unable to copy from userspace */
1065 send_sig(SIGKILL, current, 0);
1066 goto out;
1067 } else if (len_tmp == (len_max - len_buf)) {
1068 /* buffer is not large enough */
1069 require_data = true;
1070 /* NOTE: if we are going to span multiple
1071 * buffers force the encoding so we stand
1072 * a chance at a sane len_full value and
1073 * consistent record encoding */
1074 encode = true;
1075 len_full = len_full * 2;
1076 p += len_tmp;
1077 } else {
1078 require_data = false;
1079 if (!encode)
1080 encode = audit_string_contains_control(
1081 buf, len_tmp);
1082 /* try to use a trusted value for len_full */
1083 if (len_full < len_max)
1084 len_full = (encode ?
1085 len_tmp * 2 : len_tmp);
1086 p += len_tmp + 1;
1087 }
1088 len_buf += len_tmp;
1089 buf_head[len_buf] = '\0';
1090
1091 /* length of the buffer in the audit record? */
1092 len_abuf = (encode ? len_buf * 2 : len_buf + 2);
1093 }
1094
1095 /* write as much as we can to the audit log */
1096 if (len_buf >= 0) {
1097 /* NOTE: some magic numbers here - basically if we
1098 * can't fit a reasonable amount of data into the
1099 * existing audit buffer, flush it and start with
1100 * a new buffer */
1101 if ((sizeof(abuf) + 8) > len_rem) {
1102 len_rem = len_max;
1103 audit_log_end(*ab);
1104 *ab = audit_log_start(context,
1105 GFP_KERNEL, AUDIT_EXECVE);
1106 if (!*ab)
1107 goto out;
1108 }
1109
1110 /* create the non-arg portion of the arg record */
1111 len_tmp = 0;
1112 if (require_data || (iter > 0) ||
1113 ((len_abuf + sizeof(abuf)) > len_rem)) {
1114 if (iter == 0) {
1115 len_tmp += snprintf(&abuf[len_tmp],
1116 sizeof(abuf) - len_tmp,
1117 " a%d_len=%lu",
1118 arg, len_full);
1119 }
1120 len_tmp += snprintf(&abuf[len_tmp],
1121 sizeof(abuf) - len_tmp,
1122 " a%d[%d]=", arg, iter++);
1123 } else
1124 len_tmp += snprintf(&abuf[len_tmp],
1125 sizeof(abuf) - len_tmp,
1126 " a%d=", arg);
1127 WARN_ON(len_tmp >= sizeof(abuf));
1128 abuf[sizeof(abuf) - 1] = '\0';
1129
1130 /* log the arg in the audit record */
1131 audit_log_format(*ab, "%s", abuf);
1132 len_rem -= len_tmp;
1133 len_tmp = len_buf;
1134 if (encode) {
1135 if (len_abuf > len_rem)
1136 len_tmp = len_rem / 2; /* encoding */
1137 audit_log_n_hex(*ab, buf, len_tmp);
1138 len_rem -= len_tmp * 2;
1139 len_abuf -= len_tmp * 2;
1140 } else {
1141 if (len_abuf > len_rem)
1142 len_tmp = len_rem - 2; /* quotes */
1143 audit_log_n_string(*ab, buf, len_tmp);
1144 len_rem -= len_tmp + 2;
1145 /* don't subtract the "2" because we still need
1146 * to add quotes to the remaining string */
1147 len_abuf -= len_tmp;
1148 }
1149 len_buf -= len_tmp;
1150 buf += len_tmp;
1151 }
1152
1153 /* ready to move to the next argument? */
1154 if ((len_buf == 0) && !require_data) {
1155 arg++;
1156 iter = 0;
1157 len_full = 0;
1158 require_data = true;
1159 encode = false;
1160 }
1161 } while (arg < context->execve.argc);
1162
1163 /* NOTE: the caller handles the final audit_log_end() call */
1164
1165 out:
1166 kfree(buf_head);
1167 }
1168
show_special(struct audit_context * context,int * call_panic)1169 static void show_special(struct audit_context *context, int *call_panic)
1170 {
1171 struct audit_buffer *ab;
1172 int i;
1173
1174 ab = audit_log_start(context, GFP_KERNEL, context->type);
1175 if (!ab)
1176 return;
1177
1178 switch (context->type) {
1179 case AUDIT_SOCKETCALL: {
1180 int nargs = context->socketcall.nargs;
1181 audit_log_format(ab, "nargs=%d", nargs);
1182 for (i = 0; i < nargs; i++)
1183 audit_log_format(ab, " a%d=%lx", i,
1184 context->socketcall.args[i]);
1185 break; }
1186 case AUDIT_IPC: {
1187 u32 osid = context->ipc.osid;
1188
1189 audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
1190 from_kuid(&init_user_ns, context->ipc.uid),
1191 from_kgid(&init_user_ns, context->ipc.gid),
1192 context->ipc.mode);
1193 if (osid) {
1194 char *ctx = NULL;
1195 u32 len;
1196 if (security_secid_to_secctx(osid, &ctx, &len)) {
1197 audit_log_format(ab, " osid=%u", osid);
1198 *call_panic = 1;
1199 } else {
1200 audit_log_format(ab, " obj=%s", ctx);
1201 security_release_secctx(ctx, len);
1202 }
1203 }
1204 if (context->ipc.has_perm) {
1205 audit_log_end(ab);
1206 ab = audit_log_start(context, GFP_KERNEL,
1207 AUDIT_IPC_SET_PERM);
1208 if (unlikely(!ab))
1209 return;
1210 audit_log_format(ab,
1211 "qbytes=%lx ouid=%u ogid=%u mode=%#ho",
1212 context->ipc.qbytes,
1213 context->ipc.perm_uid,
1214 context->ipc.perm_gid,
1215 context->ipc.perm_mode);
1216 }
1217 break; }
1218 case AUDIT_MQ_OPEN: {
1219 audit_log_format(ab,
1220 "oflag=0x%x mode=%#ho mq_flags=0x%lx mq_maxmsg=%ld "
1221 "mq_msgsize=%ld mq_curmsgs=%ld",
1222 context->mq_open.oflag, context->mq_open.mode,
1223 context->mq_open.attr.mq_flags,
1224 context->mq_open.attr.mq_maxmsg,
1225 context->mq_open.attr.mq_msgsize,
1226 context->mq_open.attr.mq_curmsgs);
1227 break; }
1228 case AUDIT_MQ_SENDRECV: {
1229 audit_log_format(ab,
1230 "mqdes=%d msg_len=%zd msg_prio=%u "
1231 "abs_timeout_sec=%ld abs_timeout_nsec=%ld",
1232 context->mq_sendrecv.mqdes,
1233 context->mq_sendrecv.msg_len,
1234 context->mq_sendrecv.msg_prio,
1235 context->mq_sendrecv.abs_timeout.tv_sec,
1236 context->mq_sendrecv.abs_timeout.tv_nsec);
1237 break; }
1238 case AUDIT_MQ_NOTIFY: {
1239 audit_log_format(ab, "mqdes=%d sigev_signo=%d",
1240 context->mq_notify.mqdes,
1241 context->mq_notify.sigev_signo);
1242 break; }
1243 case AUDIT_MQ_GETSETATTR: {
1244 struct mq_attr *attr = &context->mq_getsetattr.mqstat;
1245 audit_log_format(ab,
1246 "mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
1247 "mq_curmsgs=%ld ",
1248 context->mq_getsetattr.mqdes,
1249 attr->mq_flags, attr->mq_maxmsg,
1250 attr->mq_msgsize, attr->mq_curmsgs);
1251 break; }
1252 case AUDIT_CAPSET: {
1253 audit_log_format(ab, "pid=%d", context->capset.pid);
1254 audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable);
1255 audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted);
1256 audit_log_cap(ab, "cap_pe", &context->capset.cap.effective);
1257 break; }
1258 case AUDIT_MMAP: {
1259 audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd,
1260 context->mmap.flags);
1261 break; }
1262 case AUDIT_EXECVE: {
1263 audit_log_execve_info(context, &ab);
1264 break; }
1265 }
1266 audit_log_end(ab);
1267 }
1268
audit_proctitle_rtrim(char * proctitle,int len)1269 static inline int audit_proctitle_rtrim(char *proctitle, int len)
1270 {
1271 char *end = proctitle + len - 1;
1272 while (end > proctitle && !isprint(*end))
1273 end--;
1274
1275 /* catch the case where proctitle is only 1 non-print character */
1276 len = end - proctitle + 1;
1277 len -= isprint(proctitle[len-1]) == 0;
1278 return len;
1279 }
1280
audit_log_proctitle(struct task_struct * tsk,struct audit_context * context)1281 static void audit_log_proctitle(struct task_struct *tsk,
1282 struct audit_context *context)
1283 {
1284 int res;
1285 char *buf;
1286 char *msg = "(null)";
1287 int len = strlen(msg);
1288 struct audit_buffer *ab;
1289
1290 ab = audit_log_start(context, GFP_KERNEL, AUDIT_PROCTITLE);
1291 if (!ab)
1292 return; /* audit_panic or being filtered */
1293
1294 audit_log_format(ab, "proctitle=");
1295
1296 /* Not cached */
1297 if (!context->proctitle.value) {
1298 buf = kmalloc(MAX_PROCTITLE_AUDIT_LEN, GFP_KERNEL);
1299 if (!buf)
1300 goto out;
1301 /* Historically called this from procfs naming */
1302 res = get_cmdline(tsk, buf, MAX_PROCTITLE_AUDIT_LEN);
1303 if (res == 0) {
1304 kfree(buf);
1305 goto out;
1306 }
1307 res = audit_proctitle_rtrim(buf, res);
1308 if (res == 0) {
1309 kfree(buf);
1310 goto out;
1311 }
1312 context->proctitle.value = buf;
1313 context->proctitle.len = res;
1314 }
1315 msg = context->proctitle.value;
1316 len = context->proctitle.len;
1317 out:
1318 audit_log_n_untrustedstring(ab, msg, len);
1319 audit_log_end(ab);
1320 }
1321
audit_log_exit(struct audit_context * context,struct task_struct * tsk)1322 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
1323 {
1324 int i, call_panic = 0;
1325 struct audit_buffer *ab;
1326 struct audit_aux_data *aux;
1327 struct audit_names *n;
1328
1329 /* tsk == current */
1330 context->personality = tsk->personality;
1331
1332 ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
1333 if (!ab)
1334 return; /* audit_panic has been called */
1335 audit_log_format(ab, "arch=%x syscall=%d",
1336 context->arch, context->major);
1337 if (context->personality != PER_LINUX)
1338 audit_log_format(ab, " per=%lx", context->personality);
1339 if (context->return_valid)
1340 audit_log_format(ab, " success=%s exit=%ld",
1341 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
1342 context->return_code);
1343
1344 audit_log_format(ab,
1345 " a0=%lx a1=%lx a2=%lx a3=%lx items=%d",
1346 context->argv[0],
1347 context->argv[1],
1348 context->argv[2],
1349 context->argv[3],
1350 context->name_count);
1351
1352 audit_log_task_info(ab, tsk);
1353 audit_log_key(ab, context->filterkey);
1354 audit_log_end(ab);
1355
1356 for (aux = context->aux; aux; aux = aux->next) {
1357
1358 ab = audit_log_start(context, GFP_KERNEL, aux->type);
1359 if (!ab)
1360 continue; /* audit_panic has been called */
1361
1362 switch (aux->type) {
1363
1364 case AUDIT_BPRM_FCAPS: {
1365 struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
1366 audit_log_format(ab, "fver=%x", axs->fcap_ver);
1367 audit_log_cap(ab, "fp", &axs->fcap.permitted);
1368 audit_log_cap(ab, "fi", &axs->fcap.inheritable);
1369 audit_log_format(ab, " fe=%d", axs->fcap.fE);
1370 audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted);
1371 audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable);
1372 audit_log_cap(ab, "old_pe", &axs->old_pcap.effective);
1373 audit_log_cap(ab, "new_pp", &axs->new_pcap.permitted);
1374 audit_log_cap(ab, "new_pi", &axs->new_pcap.inheritable);
1375 audit_log_cap(ab, "new_pe", &axs->new_pcap.effective);
1376 break; }
1377
1378 }
1379 audit_log_end(ab);
1380 }
1381
1382 if (context->type)
1383 show_special(context, &call_panic);
1384
1385 if (context->fds[0] >= 0) {
1386 ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR);
1387 if (ab) {
1388 audit_log_format(ab, "fd0=%d fd1=%d",
1389 context->fds[0], context->fds[1]);
1390 audit_log_end(ab);
1391 }
1392 }
1393
1394 if (context->sockaddr_len) {
1395 ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
1396 if (ab) {
1397 audit_log_format(ab, "saddr=");
1398 audit_log_n_hex(ab, (void *)context->sockaddr,
1399 context->sockaddr_len);
1400 audit_log_end(ab);
1401 }
1402 }
1403
1404 for (aux = context->aux_pids; aux; aux = aux->next) {
1405 struct audit_aux_data_pids *axs = (void *)aux;
1406
1407 for (i = 0; i < axs->pid_count; i++)
1408 if (audit_log_pid_context(context, axs->target_pid[i],
1409 axs->target_auid[i],
1410 axs->target_uid[i],
1411 axs->target_sessionid[i],
1412 axs->target_sid[i],
1413 axs->target_comm[i]))
1414 call_panic = 1;
1415 }
1416
1417 if (context->target_pid &&
1418 audit_log_pid_context(context, context->target_pid,
1419 context->target_auid, context->target_uid,
1420 context->target_sessionid,
1421 context->target_sid, context->target_comm))
1422 call_panic = 1;
1423
1424 if (context->pwd.dentry && context->pwd.mnt) {
1425 ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
1426 if (ab) {
1427 audit_log_d_path(ab, " cwd=", &context->pwd);
1428 audit_log_end(ab);
1429 }
1430 }
1431
1432 i = 0;
1433 list_for_each_entry(n, &context->names_list, list) {
1434 if (n->hidden)
1435 continue;
1436 audit_log_name(context, n, NULL, i++, &call_panic);
1437 }
1438
1439 audit_log_proctitle(tsk, context);
1440
1441 /* Send end of event record to help user space know we are finished */
1442 ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
1443 if (ab)
1444 audit_log_end(ab);
1445 if (call_panic)
1446 audit_panic("error converting sid to string");
1447 }
1448
1449 /**
1450 * audit_free - free a per-task audit context
1451 * @tsk: task whose audit context block to free
1452 *
1453 * Called from copy_process and do_exit
1454 */
__audit_free(struct task_struct * tsk)1455 void __audit_free(struct task_struct *tsk)
1456 {
1457 struct audit_context *context;
1458
1459 context = audit_take_context(tsk, 0, 0);
1460 if (!context)
1461 return;
1462
1463 /* Check for system calls that do not go through the exit
1464 * function (e.g., exit_group), then free context block.
1465 * We use GFP_ATOMIC here because we might be doing this
1466 * in the context of the idle thread */
1467 /* that can happen only if we are called from do_exit() */
1468 if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1469 audit_log_exit(context, tsk);
1470 if (!list_empty(&context->killed_trees))
1471 audit_kill_trees(&context->killed_trees);
1472
1473 audit_free_context(context);
1474 }
1475
1476 /**
1477 * audit_syscall_entry - fill in an audit record at syscall entry
1478 * @major: major syscall type (function)
1479 * @a1: additional syscall register 1
1480 * @a2: additional syscall register 2
1481 * @a3: additional syscall register 3
1482 * @a4: additional syscall register 4
1483 *
1484 * Fill in audit context at syscall entry. This only happens if the
1485 * audit context was created when the task was created and the state or
1486 * filters demand the audit context be built. If the state from the
1487 * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1488 * then the record will be written at syscall exit time (otherwise, it
1489 * will only be written if another part of the kernel requests that it
1490 * be written).
1491 */
__audit_syscall_entry(int major,unsigned long a1,unsigned long a2,unsigned long a3,unsigned long a4)1492 void __audit_syscall_entry(int major, unsigned long a1, unsigned long a2,
1493 unsigned long a3, unsigned long a4)
1494 {
1495 struct task_struct *tsk = current;
1496 struct audit_context *context = tsk->audit_context;
1497 enum audit_state state;
1498
1499 if (!context)
1500 return;
1501
1502 BUG_ON(context->in_syscall || context->name_count);
1503
1504 if (!audit_enabled)
1505 return;
1506
1507 context->arch = syscall_get_arch();
1508 context->major = major;
1509 context->argv[0] = a1;
1510 context->argv[1] = a2;
1511 context->argv[2] = a3;
1512 context->argv[3] = a4;
1513
1514 state = context->state;
1515 context->dummy = !audit_n_rules;
1516 if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
1517 context->prio = 0;
1518 state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
1519 }
1520 if (state == AUDIT_DISABLED)
1521 return;
1522
1523 context->serial = 0;
1524 context->ctime = CURRENT_TIME;
1525 context->in_syscall = 1;
1526 context->current_state = state;
1527 context->ppid = 0;
1528 }
1529
1530 /**
1531 * audit_syscall_exit - deallocate audit context after a system call
1532 * @success: success value of the syscall
1533 * @return_code: return value of the syscall
1534 *
1535 * Tear down after system call. If the audit context has been marked as
1536 * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1537 * filtering, or because some other part of the kernel wrote an audit
1538 * message), then write out the syscall information. In call cases,
1539 * free the names stored from getname().
1540 */
__audit_syscall_exit(int success,long return_code)1541 void __audit_syscall_exit(int success, long return_code)
1542 {
1543 struct task_struct *tsk = current;
1544 struct audit_context *context;
1545
1546 if (success)
1547 success = AUDITSC_SUCCESS;
1548 else
1549 success = AUDITSC_FAILURE;
1550
1551 context = audit_take_context(tsk, success, return_code);
1552 if (!context)
1553 return;
1554
1555 if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1556 audit_log_exit(context, tsk);
1557
1558 context->in_syscall = 0;
1559 context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
1560
1561 if (!list_empty(&context->killed_trees))
1562 audit_kill_trees(&context->killed_trees);
1563
1564 audit_free_names(context);
1565 unroll_tree_refs(context, NULL, 0);
1566 audit_free_aux(context);
1567 context->aux = NULL;
1568 context->aux_pids = NULL;
1569 context->target_pid = 0;
1570 context->target_sid = 0;
1571 context->sockaddr_len = 0;
1572 context->type = 0;
1573 context->fds[0] = -1;
1574 if (context->state != AUDIT_RECORD_CONTEXT) {
1575 kfree(context->filterkey);
1576 context->filterkey = NULL;
1577 }
1578 tsk->audit_context = context;
1579 }
1580
handle_one(const struct inode * inode)1581 static inline void handle_one(const struct inode *inode)
1582 {
1583 #ifdef CONFIG_AUDIT_TREE
1584 struct audit_context *context;
1585 struct audit_tree_refs *p;
1586 struct audit_chunk *chunk;
1587 int count;
1588 if (likely(hlist_empty(&inode->i_fsnotify_marks)))
1589 return;
1590 context = current->audit_context;
1591 p = context->trees;
1592 count = context->tree_count;
1593 rcu_read_lock();
1594 chunk = audit_tree_lookup(inode);
1595 rcu_read_unlock();
1596 if (!chunk)
1597 return;
1598 if (likely(put_tree_ref(context, chunk)))
1599 return;
1600 if (unlikely(!grow_tree_refs(context))) {
1601 pr_warn("out of memory, audit has lost a tree reference\n");
1602 audit_set_auditable(context);
1603 audit_put_chunk(chunk);
1604 unroll_tree_refs(context, p, count);
1605 return;
1606 }
1607 put_tree_ref(context, chunk);
1608 #endif
1609 }
1610
handle_path(const struct dentry * dentry)1611 static void handle_path(const struct dentry *dentry)
1612 {
1613 #ifdef CONFIG_AUDIT_TREE
1614 struct audit_context *context;
1615 struct audit_tree_refs *p;
1616 const struct dentry *d, *parent;
1617 struct audit_chunk *drop;
1618 unsigned long seq;
1619 int count;
1620
1621 context = current->audit_context;
1622 p = context->trees;
1623 count = context->tree_count;
1624 retry:
1625 drop = NULL;
1626 d = dentry;
1627 rcu_read_lock();
1628 seq = read_seqbegin(&rename_lock);
1629 for(;;) {
1630 struct inode *inode = d_backing_inode(d);
1631 if (inode && unlikely(!hlist_empty(&inode->i_fsnotify_marks))) {
1632 struct audit_chunk *chunk;
1633 chunk = audit_tree_lookup(inode);
1634 if (chunk) {
1635 if (unlikely(!put_tree_ref(context, chunk))) {
1636 drop = chunk;
1637 break;
1638 }
1639 }
1640 }
1641 parent = d->d_parent;
1642 if (parent == d)
1643 break;
1644 d = parent;
1645 }
1646 if (unlikely(read_seqretry(&rename_lock, seq) || drop)) { /* in this order */
1647 rcu_read_unlock();
1648 if (!drop) {
1649 /* just a race with rename */
1650 unroll_tree_refs(context, p, count);
1651 goto retry;
1652 }
1653 audit_put_chunk(drop);
1654 if (grow_tree_refs(context)) {
1655 /* OK, got more space */
1656 unroll_tree_refs(context, p, count);
1657 goto retry;
1658 }
1659 /* too bad */
1660 pr_warn("out of memory, audit has lost a tree reference\n");
1661 unroll_tree_refs(context, p, count);
1662 audit_set_auditable(context);
1663 return;
1664 }
1665 rcu_read_unlock();
1666 #endif
1667 }
1668
audit_alloc_name(struct audit_context * context,unsigned char type)1669 static struct audit_names *audit_alloc_name(struct audit_context *context,
1670 unsigned char type)
1671 {
1672 struct audit_names *aname;
1673
1674 if (context->name_count < AUDIT_NAMES) {
1675 aname = &context->preallocated_names[context->name_count];
1676 memset(aname, 0, sizeof(*aname));
1677 } else {
1678 aname = kzalloc(sizeof(*aname), GFP_NOFS);
1679 if (!aname)
1680 return NULL;
1681 aname->should_free = true;
1682 }
1683
1684 aname->ino = AUDIT_INO_UNSET;
1685 aname->type = type;
1686 list_add_tail(&aname->list, &context->names_list);
1687
1688 context->name_count++;
1689 return aname;
1690 }
1691
1692 /**
1693 * audit_reusename - fill out filename with info from existing entry
1694 * @uptr: userland ptr to pathname
1695 *
1696 * Search the audit_names list for the current audit context. If there is an
1697 * existing entry with a matching "uptr" then return the filename
1698 * associated with that audit_name. If not, return NULL.
1699 */
1700 struct filename *
__audit_reusename(const __user char * uptr)1701 __audit_reusename(const __user char *uptr)
1702 {
1703 struct audit_context *context = current->audit_context;
1704 struct audit_names *n;
1705
1706 list_for_each_entry(n, &context->names_list, list) {
1707 if (!n->name)
1708 continue;
1709 if (n->name->uptr == uptr) {
1710 n->name->refcnt++;
1711 return n->name;
1712 }
1713 }
1714 return NULL;
1715 }
1716
1717 /**
1718 * audit_getname - add a name to the list
1719 * @name: name to add
1720 *
1721 * Add a name to the list of audit names for this context.
1722 * Called from fs/namei.c:getname().
1723 */
__audit_getname(struct filename * name)1724 void __audit_getname(struct filename *name)
1725 {
1726 struct audit_context *context = current->audit_context;
1727 struct audit_names *n;
1728
1729 if (!context->in_syscall)
1730 return;
1731
1732 n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1733 if (!n)
1734 return;
1735
1736 n->name = name;
1737 n->name_len = AUDIT_NAME_FULL;
1738 name->aname = n;
1739 name->refcnt++;
1740
1741 if (!context->pwd.dentry)
1742 get_fs_pwd(current->fs, &context->pwd);
1743 }
1744
1745 /**
1746 * __audit_inode - store the inode and device from a lookup
1747 * @name: name being audited
1748 * @dentry: dentry being audited
1749 * @flags: attributes for this particular entry
1750 */
__audit_inode(struct filename * name,const struct dentry * dentry,unsigned int flags)1751 void __audit_inode(struct filename *name, const struct dentry *dentry,
1752 unsigned int flags)
1753 {
1754 struct audit_context *context = current->audit_context;
1755 const struct inode *inode = d_backing_inode(dentry);
1756 struct audit_names *n;
1757 bool parent = flags & AUDIT_INODE_PARENT;
1758
1759 if (!context->in_syscall)
1760 return;
1761
1762 if (!name)
1763 goto out_alloc;
1764
1765 /*
1766 * If we have a pointer to an audit_names entry already, then we can
1767 * just use it directly if the type is correct.
1768 */
1769 n = name->aname;
1770 if (n) {
1771 if (parent) {
1772 if (n->type == AUDIT_TYPE_PARENT ||
1773 n->type == AUDIT_TYPE_UNKNOWN)
1774 goto out;
1775 } else {
1776 if (n->type != AUDIT_TYPE_PARENT)
1777 goto out;
1778 }
1779 }
1780
1781 list_for_each_entry_reverse(n, &context->names_list, list) {
1782 if (n->ino) {
1783 /* valid inode number, use that for the comparison */
1784 if (n->ino != inode->i_ino ||
1785 n->dev != inode->i_sb->s_dev)
1786 continue;
1787 } else if (n->name) {
1788 /* inode number has not been set, check the name */
1789 if (strcmp(n->name->name, name->name))
1790 continue;
1791 } else
1792 /* no inode and no name (?!) ... this is odd ... */
1793 continue;
1794
1795 /* match the correct record type */
1796 if (parent) {
1797 if (n->type == AUDIT_TYPE_PARENT ||
1798 n->type == AUDIT_TYPE_UNKNOWN)
1799 goto out;
1800 } else {
1801 if (n->type != AUDIT_TYPE_PARENT)
1802 goto out;
1803 }
1804 }
1805
1806 out_alloc:
1807 /* unable to find an entry with both a matching name and type */
1808 n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1809 if (!n)
1810 return;
1811 if (name) {
1812 n->name = name;
1813 name->refcnt++;
1814 }
1815
1816 out:
1817 if (parent) {
1818 n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL;
1819 n->type = AUDIT_TYPE_PARENT;
1820 if (flags & AUDIT_INODE_HIDDEN)
1821 n->hidden = true;
1822 } else {
1823 n->name_len = AUDIT_NAME_FULL;
1824 n->type = AUDIT_TYPE_NORMAL;
1825 }
1826 handle_path(dentry);
1827 audit_copy_inode(n, dentry, inode);
1828 }
1829
__audit_file(const struct file * file)1830 void __audit_file(const struct file *file)
1831 {
1832 __audit_inode(NULL, file->f_path.dentry, 0);
1833 }
1834
1835 /**
1836 * __audit_inode_child - collect inode info for created/removed objects
1837 * @parent: inode of dentry parent
1838 * @dentry: dentry being audited
1839 * @type: AUDIT_TYPE_* value that we're looking for
1840 *
1841 * For syscalls that create or remove filesystem objects, audit_inode
1842 * can only collect information for the filesystem object's parent.
1843 * This call updates the audit context with the child's information.
1844 * Syscalls that create a new filesystem object must be hooked after
1845 * the object is created. Syscalls that remove a filesystem object
1846 * must be hooked prior, in order to capture the target inode during
1847 * unsuccessful attempts.
1848 */
__audit_inode_child(const struct inode * parent,const struct dentry * dentry,const unsigned char type)1849 void __audit_inode_child(const struct inode *parent,
1850 const struct dentry *dentry,
1851 const unsigned char type)
1852 {
1853 struct audit_context *context = current->audit_context;
1854 const struct inode *inode = d_backing_inode(dentry);
1855 const char *dname = dentry->d_name.name;
1856 struct audit_names *n, *found_parent = NULL, *found_child = NULL;
1857
1858 if (!context->in_syscall)
1859 return;
1860
1861 if (inode)
1862 handle_one(inode);
1863
1864 /* look for a parent entry first */
1865 list_for_each_entry(n, &context->names_list, list) {
1866 if (!n->name ||
1867 (n->type != AUDIT_TYPE_PARENT &&
1868 n->type != AUDIT_TYPE_UNKNOWN))
1869 continue;
1870
1871 if (n->ino == parent->i_ino && n->dev == parent->i_sb->s_dev &&
1872 !audit_compare_dname_path(dname,
1873 n->name->name, n->name_len)) {
1874 if (n->type == AUDIT_TYPE_UNKNOWN)
1875 n->type = AUDIT_TYPE_PARENT;
1876 found_parent = n;
1877 break;
1878 }
1879 }
1880
1881 /* is there a matching child entry? */
1882 list_for_each_entry(n, &context->names_list, list) {
1883 /* can only match entries that have a name */
1884 if (!n->name ||
1885 (n->type != type && n->type != AUDIT_TYPE_UNKNOWN))
1886 continue;
1887
1888 if (!strcmp(dname, n->name->name) ||
1889 !audit_compare_dname_path(dname, n->name->name,
1890 found_parent ?
1891 found_parent->name_len :
1892 AUDIT_NAME_FULL)) {
1893 if (n->type == AUDIT_TYPE_UNKNOWN)
1894 n->type = type;
1895 found_child = n;
1896 break;
1897 }
1898 }
1899
1900 if (!found_parent) {
1901 /* create a new, "anonymous" parent record */
1902 n = audit_alloc_name(context, AUDIT_TYPE_PARENT);
1903 if (!n)
1904 return;
1905 audit_copy_inode(n, NULL, parent);
1906 }
1907
1908 if (!found_child) {
1909 found_child = audit_alloc_name(context, type);
1910 if (!found_child)
1911 return;
1912
1913 /* Re-use the name belonging to the slot for a matching parent
1914 * directory. All names for this context are relinquished in
1915 * audit_free_names() */
1916 if (found_parent) {
1917 found_child->name = found_parent->name;
1918 found_child->name_len = AUDIT_NAME_FULL;
1919 found_child->name->refcnt++;
1920 }
1921 }
1922
1923 if (inode)
1924 audit_copy_inode(found_child, dentry, inode);
1925 else
1926 found_child->ino = AUDIT_INO_UNSET;
1927 }
1928 EXPORT_SYMBOL_GPL(__audit_inode_child);
1929
1930 /**
1931 * auditsc_get_stamp - get local copies of audit_context values
1932 * @ctx: audit_context for the task
1933 * @t: timespec to store time recorded in the audit_context
1934 * @serial: serial value that is recorded in the audit_context
1935 *
1936 * Also sets the context as auditable.
1937 */
auditsc_get_stamp(struct audit_context * ctx,struct timespec * t,unsigned int * serial)1938 int auditsc_get_stamp(struct audit_context *ctx,
1939 struct timespec *t, unsigned int *serial)
1940 {
1941 if (!ctx->in_syscall)
1942 return 0;
1943 if (!ctx->serial)
1944 ctx->serial = audit_serial();
1945 t->tv_sec = ctx->ctime.tv_sec;
1946 t->tv_nsec = ctx->ctime.tv_nsec;
1947 *serial = ctx->serial;
1948 if (!ctx->prio) {
1949 ctx->prio = 1;
1950 ctx->current_state = AUDIT_RECORD_CONTEXT;
1951 }
1952 return 1;
1953 }
1954
1955 /* global counter which is incremented every time something logs in */
1956 static atomic_t session_id = ATOMIC_INIT(0);
1957
audit_set_loginuid_perm(kuid_t loginuid)1958 static int audit_set_loginuid_perm(kuid_t loginuid)
1959 {
1960 /* if we are unset, we don't need privs */
1961 if (!audit_loginuid_set(current))
1962 return 0;
1963 /* if AUDIT_FEATURE_LOGINUID_IMMUTABLE means never ever allow a change*/
1964 if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
1965 return -EPERM;
1966 /* it is set, you need permission */
1967 if (!capable(CAP_AUDIT_CONTROL))
1968 return -EPERM;
1969 /* reject if this is not an unset and we don't allow that */
1970 if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID) && uid_valid(loginuid))
1971 return -EPERM;
1972 return 0;
1973 }
1974
audit_log_set_loginuid(kuid_t koldloginuid,kuid_t kloginuid,unsigned int oldsessionid,unsigned int sessionid,int rc)1975 static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
1976 unsigned int oldsessionid, unsigned int sessionid,
1977 int rc)
1978 {
1979 struct audit_buffer *ab;
1980 uid_t uid, oldloginuid, loginuid;
1981 struct tty_struct *tty;
1982
1983 if (!audit_enabled)
1984 return;
1985
1986 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
1987 if (!ab)
1988 return;
1989
1990 uid = from_kuid(&init_user_ns, task_uid(current));
1991 oldloginuid = from_kuid(&init_user_ns, koldloginuid);
1992 loginuid = from_kuid(&init_user_ns, kloginuid),
1993 tty = audit_get_tty(current);
1994
1995 audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
1996 audit_log_task_context(ab);
1997 audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
1998 oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
1999 oldsessionid, sessionid, !rc);
2000 audit_put_tty(tty);
2001 audit_log_end(ab);
2002 }
2003
2004 /**
2005 * audit_set_loginuid - set current task's audit_context loginuid
2006 * @loginuid: loginuid value
2007 *
2008 * Returns 0.
2009 *
2010 * Called (set) from fs/proc/base.c::proc_loginuid_write().
2011 */
audit_set_loginuid(kuid_t loginuid)2012 int audit_set_loginuid(kuid_t loginuid)
2013 {
2014 struct task_struct *task = current;
2015 unsigned int oldsessionid, sessionid = (unsigned int)-1;
2016 kuid_t oldloginuid;
2017 int rc;
2018
2019 oldloginuid = audit_get_loginuid(current);
2020 oldsessionid = audit_get_sessionid(current);
2021
2022 rc = audit_set_loginuid_perm(loginuid);
2023 if (rc)
2024 goto out;
2025
2026 /* are we setting or clearing? */
2027 if (uid_valid(loginuid))
2028 sessionid = (unsigned int)atomic_inc_return(&session_id);
2029
2030 task->sessionid = sessionid;
2031 task->loginuid = loginuid;
2032 out:
2033 audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
2034 return rc;
2035 }
2036
2037 /**
2038 * __audit_mq_open - record audit data for a POSIX MQ open
2039 * @oflag: open flag
2040 * @mode: mode bits
2041 * @attr: queue attributes
2042 *
2043 */
__audit_mq_open(int oflag,umode_t mode,struct mq_attr * attr)2044 void __audit_mq_open(int oflag, umode_t mode, struct mq_attr *attr)
2045 {
2046 struct audit_context *context = current->audit_context;
2047
2048 if (attr)
2049 memcpy(&context->mq_open.attr, attr, sizeof(struct mq_attr));
2050 else
2051 memset(&context->mq_open.attr, 0, sizeof(struct mq_attr));
2052
2053 context->mq_open.oflag = oflag;
2054 context->mq_open.mode = mode;
2055
2056 context->type = AUDIT_MQ_OPEN;
2057 }
2058
2059 /**
2060 * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive
2061 * @mqdes: MQ descriptor
2062 * @msg_len: Message length
2063 * @msg_prio: Message priority
2064 * @abs_timeout: Message timeout in absolute time
2065 *
2066 */
__audit_mq_sendrecv(mqd_t mqdes,size_t msg_len,unsigned int msg_prio,const struct timespec * abs_timeout)2067 void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
2068 const struct timespec *abs_timeout)
2069 {
2070 struct audit_context *context = current->audit_context;
2071 struct timespec *p = &context->mq_sendrecv.abs_timeout;
2072
2073 if (abs_timeout)
2074 memcpy(p, abs_timeout, sizeof(struct timespec));
2075 else
2076 memset(p, 0, sizeof(struct timespec));
2077
2078 context->mq_sendrecv.mqdes = mqdes;
2079 context->mq_sendrecv.msg_len = msg_len;
2080 context->mq_sendrecv.msg_prio = msg_prio;
2081
2082 context->type = AUDIT_MQ_SENDRECV;
2083 }
2084
2085 /**
2086 * __audit_mq_notify - record audit data for a POSIX MQ notify
2087 * @mqdes: MQ descriptor
2088 * @notification: Notification event
2089 *
2090 */
2091
__audit_mq_notify(mqd_t mqdes,const struct sigevent * notification)2092 void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
2093 {
2094 struct audit_context *context = current->audit_context;
2095
2096 if (notification)
2097 context->mq_notify.sigev_signo = notification->sigev_signo;
2098 else
2099 context->mq_notify.sigev_signo = 0;
2100
2101 context->mq_notify.mqdes = mqdes;
2102 context->type = AUDIT_MQ_NOTIFY;
2103 }
2104
2105 /**
2106 * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
2107 * @mqdes: MQ descriptor
2108 * @mqstat: MQ flags
2109 *
2110 */
__audit_mq_getsetattr(mqd_t mqdes,struct mq_attr * mqstat)2111 void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
2112 {
2113 struct audit_context *context = current->audit_context;
2114 context->mq_getsetattr.mqdes = mqdes;
2115 context->mq_getsetattr.mqstat = *mqstat;
2116 context->type = AUDIT_MQ_GETSETATTR;
2117 }
2118
2119 /**
2120 * audit_ipc_obj - record audit data for ipc object
2121 * @ipcp: ipc permissions
2122 *
2123 */
__audit_ipc_obj(struct kern_ipc_perm * ipcp)2124 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
2125 {
2126 struct audit_context *context = current->audit_context;
2127 context->ipc.uid = ipcp->uid;
2128 context->ipc.gid = ipcp->gid;
2129 context->ipc.mode = ipcp->mode;
2130 context->ipc.has_perm = 0;
2131 security_ipc_getsecid(ipcp, &context->ipc.osid);
2132 context->type = AUDIT_IPC;
2133 }
2134
2135 /**
2136 * audit_ipc_set_perm - record audit data for new ipc permissions
2137 * @qbytes: msgq bytes
2138 * @uid: msgq user id
2139 * @gid: msgq group id
2140 * @mode: msgq mode (permissions)
2141 *
2142 * Called only after audit_ipc_obj().
2143 */
__audit_ipc_set_perm(unsigned long qbytes,uid_t uid,gid_t gid,umode_t mode)2144 void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode)
2145 {
2146 struct audit_context *context = current->audit_context;
2147
2148 context->ipc.qbytes = qbytes;
2149 context->ipc.perm_uid = uid;
2150 context->ipc.perm_gid = gid;
2151 context->ipc.perm_mode = mode;
2152 context->ipc.has_perm = 1;
2153 }
2154
__audit_bprm(struct linux_binprm * bprm)2155 void __audit_bprm(struct linux_binprm *bprm)
2156 {
2157 struct audit_context *context = current->audit_context;
2158
2159 context->type = AUDIT_EXECVE;
2160 context->execve.argc = bprm->argc;
2161 }
2162
2163
2164 /**
2165 * audit_socketcall - record audit data for sys_socketcall
2166 * @nargs: number of args, which should not be more than AUDITSC_ARGS.
2167 * @args: args array
2168 *
2169 */
__audit_socketcall(int nargs,unsigned long * args)2170 int __audit_socketcall(int nargs, unsigned long *args)
2171 {
2172 struct audit_context *context = current->audit_context;
2173
2174 if (nargs <= 0 || nargs > AUDITSC_ARGS || !args)
2175 return -EINVAL;
2176 context->type = AUDIT_SOCKETCALL;
2177 context->socketcall.nargs = nargs;
2178 memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long));
2179 return 0;
2180 }
2181
2182 /**
2183 * __audit_fd_pair - record audit data for pipe and socketpair
2184 * @fd1: the first file descriptor
2185 * @fd2: the second file descriptor
2186 *
2187 */
__audit_fd_pair(int fd1,int fd2)2188 void __audit_fd_pair(int fd1, int fd2)
2189 {
2190 struct audit_context *context = current->audit_context;
2191 context->fds[0] = fd1;
2192 context->fds[1] = fd2;
2193 }
2194
2195 /**
2196 * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
2197 * @len: data length in user space
2198 * @a: data address in kernel space
2199 *
2200 * Returns 0 for success or NULL context or < 0 on error.
2201 */
__audit_sockaddr(int len,void * a)2202 int __audit_sockaddr(int len, void *a)
2203 {
2204 struct audit_context *context = current->audit_context;
2205
2206 if (!context->sockaddr) {
2207 void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL);
2208 if (!p)
2209 return -ENOMEM;
2210 context->sockaddr = p;
2211 }
2212
2213 context->sockaddr_len = len;
2214 memcpy(context->sockaddr, a, len);
2215 return 0;
2216 }
2217
__audit_ptrace(struct task_struct * t)2218 void __audit_ptrace(struct task_struct *t)
2219 {
2220 struct audit_context *context = current->audit_context;
2221
2222 context->target_pid = task_tgid_nr(t);
2223 context->target_auid = audit_get_loginuid(t);
2224 context->target_uid = task_uid(t);
2225 context->target_sessionid = audit_get_sessionid(t);
2226 security_task_getsecid(t, &context->target_sid);
2227 memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
2228 }
2229
2230 /**
2231 * audit_signal_info - record signal info for shutting down audit subsystem
2232 * @sig: signal value
2233 * @t: task being signaled
2234 *
2235 * If the audit subsystem is being terminated, record the task (pid)
2236 * and uid that is doing that.
2237 */
__audit_signal_info(int sig,struct task_struct * t)2238 int __audit_signal_info(int sig, struct task_struct *t)
2239 {
2240 struct audit_aux_data_pids *axp;
2241 struct task_struct *tsk = current;
2242 struct audit_context *ctx = tsk->audit_context;
2243 kuid_t uid = current_uid(), t_uid = task_uid(t);
2244
2245 if (audit_pid && t->tgid == audit_pid) {
2246 if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) {
2247 audit_sig_pid = task_tgid_nr(tsk);
2248 if (uid_valid(tsk->loginuid))
2249 audit_sig_uid = tsk->loginuid;
2250 else
2251 audit_sig_uid = uid;
2252 security_task_getsecid(tsk, &audit_sig_sid);
2253 }
2254 if (!audit_signals || audit_dummy_context())
2255 return 0;
2256 }
2257
2258 /* optimize the common case by putting first signal recipient directly
2259 * in audit_context */
2260 if (!ctx->target_pid) {
2261 ctx->target_pid = task_tgid_nr(t);
2262 ctx->target_auid = audit_get_loginuid(t);
2263 ctx->target_uid = t_uid;
2264 ctx->target_sessionid = audit_get_sessionid(t);
2265 security_task_getsecid(t, &ctx->target_sid);
2266 memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
2267 return 0;
2268 }
2269
2270 axp = (void *)ctx->aux_pids;
2271 if (!axp || axp->pid_count == AUDIT_AUX_PIDS) {
2272 axp = kzalloc(sizeof(*axp), GFP_ATOMIC);
2273 if (!axp)
2274 return -ENOMEM;
2275
2276 axp->d.type = AUDIT_OBJ_PID;
2277 axp->d.next = ctx->aux_pids;
2278 ctx->aux_pids = (void *)axp;
2279 }
2280 BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);
2281
2282 axp->target_pid[axp->pid_count] = task_tgid_nr(t);
2283 axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
2284 axp->target_uid[axp->pid_count] = t_uid;
2285 axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
2286 security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
2287 memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
2288 axp->pid_count++;
2289
2290 return 0;
2291 }
2292
2293 /**
2294 * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps
2295 * @bprm: pointer to the bprm being processed
2296 * @new: the proposed new credentials
2297 * @old: the old credentials
2298 *
2299 * Simply check if the proc already has the caps given by the file and if not
2300 * store the priv escalation info for later auditing at the end of the syscall
2301 *
2302 * -Eric
2303 */
__audit_log_bprm_fcaps(struct linux_binprm * bprm,const struct cred * new,const struct cred * old)2304 int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
2305 const struct cred *new, const struct cred *old)
2306 {
2307 struct audit_aux_data_bprm_fcaps *ax;
2308 struct audit_context *context = current->audit_context;
2309 struct cpu_vfs_cap_data vcaps;
2310
2311 ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2312 if (!ax)
2313 return -ENOMEM;
2314
2315 ax->d.type = AUDIT_BPRM_FCAPS;
2316 ax->d.next = context->aux;
2317 context->aux = (void *)ax;
2318
2319 get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps);
2320
2321 ax->fcap.permitted = vcaps.permitted;
2322 ax->fcap.inheritable = vcaps.inheritable;
2323 ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2324 ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
2325
2326 ax->old_pcap.permitted = old->cap_permitted;
2327 ax->old_pcap.inheritable = old->cap_inheritable;
2328 ax->old_pcap.effective = old->cap_effective;
2329
2330 ax->new_pcap.permitted = new->cap_permitted;
2331 ax->new_pcap.inheritable = new->cap_inheritable;
2332 ax->new_pcap.effective = new->cap_effective;
2333 return 0;
2334 }
2335
2336 /**
2337 * __audit_log_capset - store information about the arguments to the capset syscall
2338 * @new: the new credentials
2339 * @old: the old (current) credentials
2340 *
2341 * Record the arguments userspace sent to sys_capset for later printing by the
2342 * audit system if applicable
2343 */
__audit_log_capset(const struct cred * new,const struct cred * old)2344 void __audit_log_capset(const struct cred *new, const struct cred *old)
2345 {
2346 struct audit_context *context = current->audit_context;
2347 context->capset.pid = task_tgid_nr(current);
2348 context->capset.cap.effective = new->cap_effective;
2349 context->capset.cap.inheritable = new->cap_effective;
2350 context->capset.cap.permitted = new->cap_permitted;
2351 context->type = AUDIT_CAPSET;
2352 }
2353
__audit_mmap_fd(int fd,int flags)2354 void __audit_mmap_fd(int fd, int flags)
2355 {
2356 struct audit_context *context = current->audit_context;
2357 context->mmap.fd = fd;
2358 context->mmap.flags = flags;
2359 context->type = AUDIT_MMAP;
2360 }
2361
audit_log_task(struct audit_buffer * ab)2362 static void audit_log_task(struct audit_buffer *ab)
2363 {
2364 kuid_t auid, uid;
2365 kgid_t gid;
2366 unsigned int sessionid;
2367 char comm[sizeof(current->comm)];
2368
2369 auid = audit_get_loginuid(current);
2370 sessionid = audit_get_sessionid(current);
2371 current_uid_gid(&uid, &gid);
2372
2373 audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
2374 from_kuid(&init_user_ns, auid),
2375 from_kuid(&init_user_ns, uid),
2376 from_kgid(&init_user_ns, gid),
2377 sessionid);
2378 audit_log_task_context(ab);
2379 audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
2380 audit_log_untrustedstring(ab, get_task_comm(comm, current));
2381 audit_log_d_path_exe(ab, current->mm);
2382 }
2383
2384 /**
2385 * audit_core_dumps - record information about processes that end abnormally
2386 * @signr: signal value
2387 *
2388 * If a process ends with a core dump, something fishy is going on and we
2389 * should record the event for investigation.
2390 */
audit_core_dumps(long signr)2391 void audit_core_dumps(long signr)
2392 {
2393 struct audit_buffer *ab;
2394
2395 if (!audit_enabled)
2396 return;
2397
2398 if (signr == SIGQUIT) /* don't care for those */
2399 return;
2400
2401 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
2402 if (unlikely(!ab))
2403 return;
2404 audit_log_task(ab);
2405 audit_log_format(ab, " sig=%ld", signr);
2406 audit_log_end(ab);
2407 }
2408
__audit_seccomp(unsigned long syscall,long signr,int code)2409 void __audit_seccomp(unsigned long syscall, long signr, int code)
2410 {
2411 struct audit_buffer *ab;
2412
2413 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
2414 if (unlikely(!ab))
2415 return;
2416 audit_log_task(ab);
2417 audit_log_format(ab, " sig=%ld arch=%x syscall=%ld compat=%d ip=0x%lx code=0x%x",
2418 signr, syscall_get_arch(), syscall, is_compat_task(),
2419 KSTK_EIP(current), code);
2420 audit_log_end(ab);
2421 }
2422
audit_killed_trees(void)2423 struct list_head *audit_killed_trees(void)
2424 {
2425 struct audit_context *ctx = current->audit_context;
2426 if (likely(!ctx || !ctx->in_syscall))
2427 return NULL;
2428 return &ctx->killed_trees;
2429 }
2430