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 #include <linux/init.h>
46 #include <asm/types.h>
47 #include <asm/atomic.h>
48 #include <linux/fs.h>
49 #include <linux/namei.h>
50 #include <linux/mm.h>
51 #include <linux/module.h>
52 #include <linux/slab.h>
53 #include <linux/mount.h>
54 #include <linux/socket.h>
55 #include <linux/mqueue.h>
56 #include <linux/audit.h>
57 #include <linux/personality.h>
58 #include <linux/time.h>
59 #include <linux/netlink.h>
60 #include <linux/compiler.h>
61 #include <asm/unistd.h>
62 #include <linux/security.h>
63 #include <linux/list.h>
64 #include <linux/tty.h>
65 #include <linux/binfmts.h>
66 #include <linux/highmem.h>
67 #include <linux/syscalls.h>
68 #include <linux/capability.h>
69 #include <linux/fs_struct.h>
70 
71 #include "audit.h"
72 
73 /* AUDIT_NAMES is the number of slots we reserve in the audit_context
74  * for saving names from getname(). */
75 #define AUDIT_NAMES    20
76 
77 /* Indicates that audit should log the full pathname. */
78 #define AUDIT_NAME_FULL -1
79 
80 /* no execve audit message should be longer than this (userspace limits) */
81 #define MAX_EXECVE_AUDIT_LEN 7500
82 
83 /* number of audit rules */
84 int audit_n_rules;
85 
86 /* determines whether we collect data for signals sent */
87 int audit_signals;
88 
89 struct audit_cap_data {
90 	kernel_cap_t		permitted;
91 	kernel_cap_t		inheritable;
92 	union {
93 		unsigned int	fE;		/* effective bit of a file capability */
94 		kernel_cap_t	effective;	/* effective set of a process */
95 	};
96 };
97 
98 /* When fs/namei.c:getname() is called, we store the pointer in name and
99  * we don't let putname() free it (instead we free all of the saved
100  * pointers at syscall exit time).
101  *
102  * Further, in fs/namei.c:path_lookup() we store the inode and device. */
103 struct audit_names {
104 	const char	*name;
105 	int		name_len;	/* number of name's characters to log */
106 	unsigned	name_put;	/* call __putname() for this name */
107 	unsigned long	ino;
108 	dev_t		dev;
109 	umode_t		mode;
110 	uid_t		uid;
111 	gid_t		gid;
112 	dev_t		rdev;
113 	u32		osid;
114 	struct audit_cap_data fcap;
115 	unsigned int	fcap_ver;
116 };
117 
118 struct audit_aux_data {
119 	struct audit_aux_data	*next;
120 	int			type;
121 };
122 
123 #define AUDIT_AUX_IPCPERM	0
124 
125 /* Number of target pids per aux struct. */
126 #define AUDIT_AUX_PIDS	16
127 
128 struct audit_aux_data_execve {
129 	struct audit_aux_data	d;
130 	int argc;
131 	int envc;
132 	struct mm_struct *mm;
133 };
134 
135 struct audit_aux_data_pids {
136 	struct audit_aux_data	d;
137 	pid_t			target_pid[AUDIT_AUX_PIDS];
138 	uid_t			target_auid[AUDIT_AUX_PIDS];
139 	uid_t			target_uid[AUDIT_AUX_PIDS];
140 	unsigned int		target_sessionid[AUDIT_AUX_PIDS];
141 	u32			target_sid[AUDIT_AUX_PIDS];
142 	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
143 	int			pid_count;
144 };
145 
146 struct audit_aux_data_bprm_fcaps {
147 	struct audit_aux_data	d;
148 	struct audit_cap_data	fcap;
149 	unsigned int		fcap_ver;
150 	struct audit_cap_data	old_pcap;
151 	struct audit_cap_data	new_pcap;
152 };
153 
154 struct audit_aux_data_capset {
155 	struct audit_aux_data	d;
156 	pid_t			pid;
157 	struct audit_cap_data	cap;
158 };
159 
160 struct audit_tree_refs {
161 	struct audit_tree_refs *next;
162 	struct audit_chunk *c[31];
163 };
164 
165 /* The per-task audit context. */
166 struct audit_context {
167 	int		    dummy;	/* must be the first element */
168 	int		    in_syscall;	/* 1 if task is in a syscall */
169 	enum audit_state    state, current_state;
170 	unsigned int	    serial;     /* serial number for record */
171 	int		    major;      /* syscall number */
172 	struct timespec	    ctime;      /* time of syscall entry */
173 	unsigned long	    argv[4];    /* syscall arguments */
174 	long		    return_code;/* syscall return code */
175 	u64		    prio;
176 	int		    return_valid; /* return code is valid */
177 	int		    name_count;
178 	struct audit_names  names[AUDIT_NAMES];
179 	char *		    filterkey;	/* key for rule that triggered record */
180 	struct path	    pwd;
181 	struct audit_context *previous; /* For nested syscalls */
182 	struct audit_aux_data *aux;
183 	struct audit_aux_data *aux_pids;
184 	struct sockaddr_storage *sockaddr;
185 	size_t sockaddr_len;
186 				/* Save things to print about task_struct */
187 	pid_t		    pid, ppid;
188 	uid_t		    uid, euid, suid, fsuid;
189 	gid_t		    gid, egid, sgid, fsgid;
190 	unsigned long	    personality;
191 	int		    arch;
192 
193 	pid_t		    target_pid;
194 	uid_t		    target_auid;
195 	uid_t		    target_uid;
196 	unsigned int	    target_sessionid;
197 	u32		    target_sid;
198 	char		    target_comm[TASK_COMM_LEN];
199 
200 	struct audit_tree_refs *trees, *first_trees;
201 	struct list_head killed_trees;
202 	int tree_count;
203 
204 	int type;
205 	union {
206 		struct {
207 			int nargs;
208 			long args[6];
209 		} socketcall;
210 		struct {
211 			uid_t			uid;
212 			gid_t			gid;
213 			mode_t			mode;
214 			u32			osid;
215 			int			has_perm;
216 			uid_t			perm_uid;
217 			gid_t			perm_gid;
218 			mode_t			perm_mode;
219 			unsigned long		qbytes;
220 		} ipc;
221 		struct {
222 			mqd_t			mqdes;
223 			struct mq_attr 		mqstat;
224 		} mq_getsetattr;
225 		struct {
226 			mqd_t			mqdes;
227 			int			sigev_signo;
228 		} mq_notify;
229 		struct {
230 			mqd_t			mqdes;
231 			size_t			msg_len;
232 			unsigned int		msg_prio;
233 			struct timespec		abs_timeout;
234 		} mq_sendrecv;
235 		struct {
236 			int			oflag;
237 			mode_t			mode;
238 			struct mq_attr		attr;
239 		} mq_open;
240 		struct {
241 			pid_t			pid;
242 			struct audit_cap_data	cap;
243 		} capset;
244 		struct {
245 			int			fd;
246 			int			flags;
247 		} mmap;
248 	};
249 	int fds[2];
250 
251 #if AUDIT_DEBUG
252 	int		    put_count;
253 	int		    ino_count;
254 #endif
255 };
256 
open_arg(int flags,int mask)257 static inline int open_arg(int flags, int mask)
258 {
259 	int n = ACC_MODE(flags);
260 	if (flags & (O_TRUNC | O_CREAT))
261 		n |= AUDIT_PERM_WRITE;
262 	return n & mask;
263 }
264 
audit_match_perm(struct audit_context * ctx,int mask)265 static int audit_match_perm(struct audit_context *ctx, int mask)
266 {
267 	unsigned n;
268 	if (unlikely(!ctx))
269 		return 0;
270 	n = ctx->major;
271 
272 	switch (audit_classify_syscall(ctx->arch, n)) {
273 	case 0:	/* native */
274 		if ((mask & AUDIT_PERM_WRITE) &&
275 		     audit_match_class(AUDIT_CLASS_WRITE, n))
276 			return 1;
277 		if ((mask & AUDIT_PERM_READ) &&
278 		     audit_match_class(AUDIT_CLASS_READ, n))
279 			return 1;
280 		if ((mask & AUDIT_PERM_ATTR) &&
281 		     audit_match_class(AUDIT_CLASS_CHATTR, n))
282 			return 1;
283 		return 0;
284 	case 1: /* 32bit on biarch */
285 		if ((mask & AUDIT_PERM_WRITE) &&
286 		     audit_match_class(AUDIT_CLASS_WRITE_32, n))
287 			return 1;
288 		if ((mask & AUDIT_PERM_READ) &&
289 		     audit_match_class(AUDIT_CLASS_READ_32, n))
290 			return 1;
291 		if ((mask & AUDIT_PERM_ATTR) &&
292 		     audit_match_class(AUDIT_CLASS_CHATTR_32, n))
293 			return 1;
294 		return 0;
295 	case 2: /* open */
296 		return mask & ACC_MODE(ctx->argv[1]);
297 	case 3: /* openat */
298 		return mask & ACC_MODE(ctx->argv[2]);
299 	case 4: /* socketcall */
300 		return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND);
301 	case 5: /* execve */
302 		return mask & AUDIT_PERM_EXEC;
303 	default:
304 		return 0;
305 	}
306 }
307 
audit_match_filetype(struct audit_context * ctx,int which)308 static int audit_match_filetype(struct audit_context *ctx, int which)
309 {
310 	unsigned index = which & ~S_IFMT;
311 	mode_t mode = which & S_IFMT;
312 
313 	if (unlikely(!ctx))
314 		return 0;
315 
316 	if (index >= ctx->name_count)
317 		return 0;
318 	if (ctx->names[index].ino == -1)
319 		return 0;
320 	if ((ctx->names[index].mode ^ mode) & S_IFMT)
321 		return 0;
322 	return 1;
323 }
324 
325 /*
326  * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
327  * ->first_trees points to its beginning, ->trees - to the current end of data.
328  * ->tree_count is the number of free entries in array pointed to by ->trees.
329  * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
330  * "empty" becomes (p, p, 31) afterwards.  We don't shrink the list (and seriously,
331  * it's going to remain 1-element for almost any setup) until we free context itself.
332  * References in it _are_ dropped - at the same time we free/drop aux stuff.
333  */
334 
335 #ifdef CONFIG_AUDIT_TREE
audit_set_auditable(struct audit_context * ctx)336 static void audit_set_auditable(struct audit_context *ctx)
337 {
338 	if (!ctx->prio) {
339 		ctx->prio = 1;
340 		ctx->current_state = AUDIT_RECORD_CONTEXT;
341 	}
342 }
343 
put_tree_ref(struct audit_context * ctx,struct audit_chunk * chunk)344 static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
345 {
346 	struct audit_tree_refs *p = ctx->trees;
347 	int left = ctx->tree_count;
348 	if (likely(left)) {
349 		p->c[--left] = chunk;
350 		ctx->tree_count = left;
351 		return 1;
352 	}
353 	if (!p)
354 		return 0;
355 	p = p->next;
356 	if (p) {
357 		p->c[30] = chunk;
358 		ctx->trees = p;
359 		ctx->tree_count = 30;
360 		return 1;
361 	}
362 	return 0;
363 }
364 
grow_tree_refs(struct audit_context * ctx)365 static int grow_tree_refs(struct audit_context *ctx)
366 {
367 	struct audit_tree_refs *p = ctx->trees;
368 	ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
369 	if (!ctx->trees) {
370 		ctx->trees = p;
371 		return 0;
372 	}
373 	if (p)
374 		p->next = ctx->trees;
375 	else
376 		ctx->first_trees = ctx->trees;
377 	ctx->tree_count = 31;
378 	return 1;
379 }
380 #endif
381 
unroll_tree_refs(struct audit_context * ctx,struct audit_tree_refs * p,int count)382 static void unroll_tree_refs(struct audit_context *ctx,
383 		      struct audit_tree_refs *p, int count)
384 {
385 #ifdef CONFIG_AUDIT_TREE
386 	struct audit_tree_refs *q;
387 	int n;
388 	if (!p) {
389 		/* we started with empty chain */
390 		p = ctx->first_trees;
391 		count = 31;
392 		/* if the very first allocation has failed, nothing to do */
393 		if (!p)
394 			return;
395 	}
396 	n = count;
397 	for (q = p; q != ctx->trees; q = q->next, n = 31) {
398 		while (n--) {
399 			audit_put_chunk(q->c[n]);
400 			q->c[n] = NULL;
401 		}
402 	}
403 	while (n-- > ctx->tree_count) {
404 		audit_put_chunk(q->c[n]);
405 		q->c[n] = NULL;
406 	}
407 	ctx->trees = p;
408 	ctx->tree_count = count;
409 #endif
410 }
411 
free_tree_refs(struct audit_context * ctx)412 static void free_tree_refs(struct audit_context *ctx)
413 {
414 	struct audit_tree_refs *p, *q;
415 	for (p = ctx->first_trees; p; p = q) {
416 		q = p->next;
417 		kfree(p);
418 	}
419 }
420 
match_tree_refs(struct audit_context * ctx,struct audit_tree * tree)421 static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
422 {
423 #ifdef CONFIG_AUDIT_TREE
424 	struct audit_tree_refs *p;
425 	int n;
426 	if (!tree)
427 		return 0;
428 	/* full ones */
429 	for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
430 		for (n = 0; n < 31; n++)
431 			if (audit_tree_match(p->c[n], tree))
432 				return 1;
433 	}
434 	/* partial */
435 	if (p) {
436 		for (n = ctx->tree_count; n < 31; n++)
437 			if (audit_tree_match(p->c[n], tree))
438 				return 1;
439 	}
440 #endif
441 	return 0;
442 }
443 
444 /* Determine if any context name data matches a rule's watch data */
445 /* Compare a task_struct with an audit_rule.  Return 1 on match, 0
446  * otherwise. */
audit_filter_rules(struct task_struct * tsk,struct audit_krule * rule,struct audit_context * ctx,struct audit_names * name,enum audit_state * state)447 static int audit_filter_rules(struct task_struct *tsk,
448 			      struct audit_krule *rule,
449 			      struct audit_context *ctx,
450 			      struct audit_names *name,
451 			      enum audit_state *state)
452 {
453 	const struct cred *cred = get_task_cred(tsk);
454 	int i, j, need_sid = 1;
455 	u32 sid;
456 
457 	for (i = 0; i < rule->field_count; i++) {
458 		struct audit_field *f = &rule->fields[i];
459 		int result = 0;
460 
461 		switch (f->type) {
462 		case AUDIT_PID:
463 			result = audit_comparator(tsk->pid, f->op, f->val);
464 			break;
465 		case AUDIT_PPID:
466 			if (ctx) {
467 				if (!ctx->ppid)
468 					ctx->ppid = sys_getppid();
469 				result = audit_comparator(ctx->ppid, f->op, f->val);
470 			}
471 			break;
472 		case AUDIT_UID:
473 			result = audit_comparator(cred->uid, f->op, f->val);
474 			break;
475 		case AUDIT_EUID:
476 			result = audit_comparator(cred->euid, f->op, f->val);
477 			break;
478 		case AUDIT_SUID:
479 			result = audit_comparator(cred->suid, f->op, f->val);
480 			break;
481 		case AUDIT_FSUID:
482 			result = audit_comparator(cred->fsuid, f->op, f->val);
483 			break;
484 		case AUDIT_GID:
485 			result = audit_comparator(cred->gid, f->op, f->val);
486 			break;
487 		case AUDIT_EGID:
488 			result = audit_comparator(cred->egid, f->op, f->val);
489 			break;
490 		case AUDIT_SGID:
491 			result = audit_comparator(cred->sgid, f->op, f->val);
492 			break;
493 		case AUDIT_FSGID:
494 			result = audit_comparator(cred->fsgid, f->op, f->val);
495 			break;
496 		case AUDIT_PERS:
497 			result = audit_comparator(tsk->personality, f->op, f->val);
498 			break;
499 		case AUDIT_ARCH:
500 			if (ctx)
501 				result = audit_comparator(ctx->arch, f->op, f->val);
502 			break;
503 
504 		case AUDIT_EXIT:
505 			if (ctx && ctx->return_valid)
506 				result = audit_comparator(ctx->return_code, f->op, f->val);
507 			break;
508 		case AUDIT_SUCCESS:
509 			if (ctx && ctx->return_valid) {
510 				if (f->val)
511 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
512 				else
513 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);
514 			}
515 			break;
516 		case AUDIT_DEVMAJOR:
517 			if (name)
518 				result = audit_comparator(MAJOR(name->dev),
519 							  f->op, f->val);
520 			else if (ctx) {
521 				for (j = 0; j < ctx->name_count; j++) {
522 					if (audit_comparator(MAJOR(ctx->names[j].dev),	f->op, f->val)) {
523 						++result;
524 						break;
525 					}
526 				}
527 			}
528 			break;
529 		case AUDIT_DEVMINOR:
530 			if (name)
531 				result = audit_comparator(MINOR(name->dev),
532 							  f->op, f->val);
533 			else if (ctx) {
534 				for (j = 0; j < ctx->name_count; j++) {
535 					if (audit_comparator(MINOR(ctx->names[j].dev), f->op, f->val)) {
536 						++result;
537 						break;
538 					}
539 				}
540 			}
541 			break;
542 		case AUDIT_INODE:
543 			if (name)
544 				result = (name->ino == f->val);
545 			else if (ctx) {
546 				for (j = 0; j < ctx->name_count; j++) {
547 					if (audit_comparator(ctx->names[j].ino, f->op, f->val)) {
548 						++result;
549 						break;
550 					}
551 				}
552 			}
553 			break;
554 		case AUDIT_WATCH:
555 			if (name)
556 				result = audit_watch_compare(rule->watch, name->ino, name->dev);
557 			break;
558 		case AUDIT_DIR:
559 			if (ctx)
560 				result = match_tree_refs(ctx, rule->tree);
561 			break;
562 		case AUDIT_LOGINUID:
563 			result = 0;
564 			if (ctx)
565 				result = audit_comparator(tsk->loginuid, f->op, f->val);
566 			break;
567 		case AUDIT_SUBJ_USER:
568 		case AUDIT_SUBJ_ROLE:
569 		case AUDIT_SUBJ_TYPE:
570 		case AUDIT_SUBJ_SEN:
571 		case AUDIT_SUBJ_CLR:
572 			/* NOTE: this may return negative values indicating
573 			   a temporary error.  We simply treat this as a
574 			   match for now to avoid losing information that
575 			   may be wanted.   An error message will also be
576 			   logged upon error */
577 			if (f->lsm_rule) {
578 				if (need_sid) {
579 					security_task_getsecid(tsk, &sid);
580 					need_sid = 0;
581 				}
582 				result = security_audit_rule_match(sid, f->type,
583 				                                  f->op,
584 				                                  f->lsm_rule,
585 				                                  ctx);
586 			}
587 			break;
588 		case AUDIT_OBJ_USER:
589 		case AUDIT_OBJ_ROLE:
590 		case AUDIT_OBJ_TYPE:
591 		case AUDIT_OBJ_LEV_LOW:
592 		case AUDIT_OBJ_LEV_HIGH:
593 			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
594 			   also applies here */
595 			if (f->lsm_rule) {
596 				/* Find files that match */
597 				if (name) {
598 					result = security_audit_rule_match(
599 					           name->osid, f->type, f->op,
600 					           f->lsm_rule, ctx);
601 				} else if (ctx) {
602 					for (j = 0; j < ctx->name_count; j++) {
603 						if (security_audit_rule_match(
604 						      ctx->names[j].osid,
605 						      f->type, f->op,
606 						      f->lsm_rule, ctx)) {
607 							++result;
608 							break;
609 						}
610 					}
611 				}
612 				/* Find ipc objects that match */
613 				if (!ctx || ctx->type != AUDIT_IPC)
614 					break;
615 				if (security_audit_rule_match(ctx->ipc.osid,
616 							      f->type, f->op,
617 							      f->lsm_rule, ctx))
618 					++result;
619 			}
620 			break;
621 		case AUDIT_ARG0:
622 		case AUDIT_ARG1:
623 		case AUDIT_ARG2:
624 		case AUDIT_ARG3:
625 			if (ctx)
626 				result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
627 			break;
628 		case AUDIT_FILTERKEY:
629 			/* ignore this field for filtering */
630 			result = 1;
631 			break;
632 		case AUDIT_PERM:
633 			result = audit_match_perm(ctx, f->val);
634 			break;
635 		case AUDIT_FILETYPE:
636 			result = audit_match_filetype(ctx, f->val);
637 			break;
638 		}
639 
640 		if (!result) {
641 			put_cred(cred);
642 			return 0;
643 		}
644 	}
645 
646 	if (ctx) {
647 		if (rule->prio <= ctx->prio)
648 			return 0;
649 		if (rule->filterkey) {
650 			kfree(ctx->filterkey);
651 			ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
652 		}
653 		ctx->prio = rule->prio;
654 	}
655 	switch (rule->action) {
656 	case AUDIT_NEVER:    *state = AUDIT_DISABLED;	    break;
657 	case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
658 	}
659 	put_cred(cred);
660 	return 1;
661 }
662 
663 /* At process creation time, we can determine if system-call auditing is
664  * completely disabled for this task.  Since we only have the task
665  * structure at this point, we can only check uid and gid.
666  */
audit_filter_task(struct task_struct * tsk,char ** key)667 static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
668 {
669 	struct audit_entry *e;
670 	enum audit_state   state;
671 
672 	rcu_read_lock();
673 	list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
674 		if (audit_filter_rules(tsk, &e->rule, NULL, NULL, &state)) {
675 			if (state == AUDIT_RECORD_CONTEXT)
676 				*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
677 			rcu_read_unlock();
678 			return state;
679 		}
680 	}
681 	rcu_read_unlock();
682 	return AUDIT_BUILD_CONTEXT;
683 }
684 
685 /* At syscall entry and exit time, this filter is called if the
686  * audit_state is not low enough that auditing cannot take place, but is
687  * also not high enough that we already know we have to write an audit
688  * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
689  */
audit_filter_syscall(struct task_struct * tsk,struct audit_context * ctx,struct list_head * list)690 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
691 					     struct audit_context *ctx,
692 					     struct list_head *list)
693 {
694 	struct audit_entry *e;
695 	enum audit_state state;
696 
697 	if (audit_pid && tsk->tgid == audit_pid)
698 		return AUDIT_DISABLED;
699 
700 	rcu_read_lock();
701 	if (!list_empty(list)) {
702 		int word = AUDIT_WORD(ctx->major);
703 		int bit  = AUDIT_BIT(ctx->major);
704 
705 		list_for_each_entry_rcu(e, list, list) {
706 			if ((e->rule.mask[word] & bit) == bit &&
707 			    audit_filter_rules(tsk, &e->rule, ctx, NULL,
708 					       &state)) {
709 				rcu_read_unlock();
710 				ctx->current_state = state;
711 				return state;
712 			}
713 		}
714 	}
715 	rcu_read_unlock();
716 	return AUDIT_BUILD_CONTEXT;
717 }
718 
719 /* At syscall exit time, this filter is called if any audit_names[] have been
720  * collected during syscall processing.  We only check rules in sublists at hash
721  * buckets applicable to the inode numbers in audit_names[].
722  * Regarding audit_state, same rules apply as for audit_filter_syscall().
723  */
audit_filter_inodes(struct task_struct * tsk,struct audit_context * ctx)724 void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
725 {
726 	int i;
727 	struct audit_entry *e;
728 	enum audit_state state;
729 
730 	if (audit_pid && tsk->tgid == audit_pid)
731 		return;
732 
733 	rcu_read_lock();
734 	for (i = 0; i < ctx->name_count; i++) {
735 		int word = AUDIT_WORD(ctx->major);
736 		int bit  = AUDIT_BIT(ctx->major);
737 		struct audit_names *n = &ctx->names[i];
738 		int h = audit_hash_ino((u32)n->ino);
739 		struct list_head *list = &audit_inode_hash[h];
740 
741 		if (list_empty(list))
742 			continue;
743 
744 		list_for_each_entry_rcu(e, list, list) {
745 			if ((e->rule.mask[word] & bit) == bit &&
746 			    audit_filter_rules(tsk, &e->rule, ctx, n, &state)) {
747 				rcu_read_unlock();
748 				ctx->current_state = state;
749 				return;
750 			}
751 		}
752 	}
753 	rcu_read_unlock();
754 }
755 
audit_get_context(struct task_struct * tsk,int return_valid,long return_code)756 static inline struct audit_context *audit_get_context(struct task_struct *tsk,
757 						      int return_valid,
758 						      long return_code)
759 {
760 	struct audit_context *context = tsk->audit_context;
761 
762 	if (likely(!context))
763 		return NULL;
764 	context->return_valid = return_valid;
765 
766 	/*
767 	 * we need to fix up the return code in the audit logs if the actual
768 	 * return codes are later going to be fixed up by the arch specific
769 	 * signal handlers
770 	 *
771 	 * This is actually a test for:
772 	 * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) ||
773 	 * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK)
774 	 *
775 	 * but is faster than a bunch of ||
776 	 */
777 	if (unlikely(return_code <= -ERESTARTSYS) &&
778 	    (return_code >= -ERESTART_RESTARTBLOCK) &&
779 	    (return_code != -ENOIOCTLCMD))
780 		context->return_code = -EINTR;
781 	else
782 		context->return_code  = return_code;
783 
784 	if (context->in_syscall && !context->dummy) {
785 		audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
786 		audit_filter_inodes(tsk, context);
787 	}
788 
789 	tsk->audit_context = NULL;
790 	return context;
791 }
792 
audit_free_names(struct audit_context * context)793 static inline void audit_free_names(struct audit_context *context)
794 {
795 	int i;
796 
797 #if AUDIT_DEBUG == 2
798 	if (context->put_count + context->ino_count != context->name_count) {
799 		printk(KERN_ERR "%s:%d(:%d): major=%d in_syscall=%d"
800 		       " name_count=%d put_count=%d"
801 		       " ino_count=%d [NOT freeing]\n",
802 		       __FILE__, __LINE__,
803 		       context->serial, context->major, context->in_syscall,
804 		       context->name_count, context->put_count,
805 		       context->ino_count);
806 		for (i = 0; i < context->name_count; i++) {
807 			printk(KERN_ERR "names[%d] = %p = %s\n", i,
808 			       context->names[i].name,
809 			       context->names[i].name ?: "(null)");
810 		}
811 		dump_stack();
812 		return;
813 	}
814 #endif
815 #if AUDIT_DEBUG
816 	context->put_count  = 0;
817 	context->ino_count  = 0;
818 #endif
819 
820 	for (i = 0; i < context->name_count; i++) {
821 		if (context->names[i].name && context->names[i].name_put)
822 			__putname(context->names[i].name);
823 	}
824 	context->name_count = 0;
825 	path_put(&context->pwd);
826 	context->pwd.dentry = NULL;
827 	context->pwd.mnt = NULL;
828 }
829 
audit_free_aux(struct audit_context * context)830 static inline void audit_free_aux(struct audit_context *context)
831 {
832 	struct audit_aux_data *aux;
833 
834 	while ((aux = context->aux)) {
835 		context->aux = aux->next;
836 		kfree(aux);
837 	}
838 	while ((aux = context->aux_pids)) {
839 		context->aux_pids = aux->next;
840 		kfree(aux);
841 	}
842 }
843 
audit_zero_context(struct audit_context * context,enum audit_state state)844 static inline void audit_zero_context(struct audit_context *context,
845 				      enum audit_state state)
846 {
847 	memset(context, 0, sizeof(*context));
848 	context->state      = state;
849 	context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
850 }
851 
audit_alloc_context(enum audit_state state)852 static inline struct audit_context *audit_alloc_context(enum audit_state state)
853 {
854 	struct audit_context *context;
855 
856 	if (!(context = kmalloc(sizeof(*context), GFP_KERNEL)))
857 		return NULL;
858 	audit_zero_context(context, state);
859 	INIT_LIST_HEAD(&context->killed_trees);
860 	return context;
861 }
862 
863 /**
864  * audit_alloc - allocate an audit context block for a task
865  * @tsk: task
866  *
867  * Filter on the task information and allocate a per-task audit context
868  * if necessary.  Doing so turns on system call auditing for the
869  * specified task.  This is called from copy_process, so no lock is
870  * needed.
871  */
audit_alloc(struct task_struct * tsk)872 int audit_alloc(struct task_struct *tsk)
873 {
874 	struct audit_context *context;
875 	enum audit_state     state;
876 	char *key = NULL;
877 
878 	if (likely(!audit_ever_enabled))
879 		return 0; /* Return if not auditing. */
880 
881 	state = audit_filter_task(tsk, &key);
882 	if (likely(state == AUDIT_DISABLED))
883 		return 0;
884 
885 	if (!(context = audit_alloc_context(state))) {
886 		kfree(key);
887 		audit_log_lost("out of memory in audit_alloc");
888 		return -ENOMEM;
889 	}
890 	context->filterkey = key;
891 
892 	tsk->audit_context  = context;
893 	set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
894 	return 0;
895 }
896 
audit_free_context(struct audit_context * context)897 static inline void audit_free_context(struct audit_context *context)
898 {
899 	struct audit_context *previous;
900 	int		     count = 0;
901 
902 	do {
903 		previous = context->previous;
904 		if (previous || (count &&  count < 10)) {
905 			++count;
906 			printk(KERN_ERR "audit(:%d): major=%d name_count=%d:"
907 			       " freeing multiple contexts (%d)\n",
908 			       context->serial, context->major,
909 			       context->name_count, count);
910 		}
911 		audit_free_names(context);
912 		unroll_tree_refs(context, NULL, 0);
913 		free_tree_refs(context);
914 		audit_free_aux(context);
915 		kfree(context->filterkey);
916 		kfree(context->sockaddr);
917 		kfree(context);
918 		context  = previous;
919 	} while (context);
920 	if (count >= 10)
921 		printk(KERN_ERR "audit: freed %d contexts\n", count);
922 }
923 
audit_log_task_context(struct audit_buffer * ab)924 void audit_log_task_context(struct audit_buffer *ab)
925 {
926 	char *ctx = NULL;
927 	unsigned len;
928 	int error;
929 	u32 sid;
930 
931 	security_task_getsecid(current, &sid);
932 	if (!sid)
933 		return;
934 
935 	error = security_secid_to_secctx(sid, &ctx, &len);
936 	if (error) {
937 		if (error != -EINVAL)
938 			goto error_path;
939 		return;
940 	}
941 
942 	audit_log_format(ab, " subj=%s", ctx);
943 	security_release_secctx(ctx, len);
944 	return;
945 
946 error_path:
947 	audit_panic("error in audit_log_task_context");
948 	return;
949 }
950 
951 EXPORT_SYMBOL(audit_log_task_context);
952 
audit_log_task_info(struct audit_buffer * ab,struct task_struct * tsk)953 static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
954 {
955 	char name[sizeof(tsk->comm)];
956 	struct mm_struct *mm = tsk->mm;
957 	struct vm_area_struct *vma;
958 
959 	/* tsk == current */
960 
961 	get_task_comm(name, tsk);
962 	audit_log_format(ab, " comm=");
963 	audit_log_untrustedstring(ab, name);
964 
965 	if (mm) {
966 		down_read(&mm->mmap_sem);
967 		vma = mm->mmap;
968 		while (vma) {
969 			if ((vma->vm_flags & VM_EXECUTABLE) &&
970 			    vma->vm_file) {
971 				audit_log_d_path(ab, "exe=",
972 						 &vma->vm_file->f_path);
973 				break;
974 			}
975 			vma = vma->vm_next;
976 		}
977 		up_read(&mm->mmap_sem);
978 	}
979 	audit_log_task_context(ab);
980 }
981 
audit_log_pid_context(struct audit_context * context,pid_t pid,uid_t auid,uid_t uid,unsigned int sessionid,u32 sid,char * comm)982 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
983 				 uid_t auid, uid_t uid, unsigned int sessionid,
984 				 u32 sid, char *comm)
985 {
986 	struct audit_buffer *ab;
987 	char *ctx = NULL;
988 	u32 len;
989 	int rc = 0;
990 
991 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
992 	if (!ab)
993 		return rc;
994 
995 	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid, auid,
996 			 uid, sessionid);
997 	if (security_secid_to_secctx(sid, &ctx, &len)) {
998 		audit_log_format(ab, " obj=(none)");
999 		rc = 1;
1000 	} else {
1001 		audit_log_format(ab, " obj=%s", ctx);
1002 		security_release_secctx(ctx, len);
1003 	}
1004 	audit_log_format(ab, " ocomm=");
1005 	audit_log_untrustedstring(ab, comm);
1006 	audit_log_end(ab);
1007 
1008 	return rc;
1009 }
1010 
1011 /*
1012  * to_send and len_sent accounting are very loose estimates.  We aren't
1013  * really worried about a hard cap to MAX_EXECVE_AUDIT_LEN so much as being
1014  * within about 500 bytes (next page boundary)
1015  *
1016  * why snprintf?  an int is up to 12 digits long.  if we just assumed when
1017  * logging that a[%d]= was going to be 16 characters long we would be wasting
1018  * space in every audit message.  In one 7500 byte message we can log up to
1019  * about 1000 min size arguments.  That comes down to about 50% waste of space
1020  * if we didn't do the snprintf to find out how long arg_num_len was.
1021  */
audit_log_single_execve_arg(struct audit_context * context,struct audit_buffer ** ab,int arg_num,size_t * len_sent,const char __user * p,char * buf)1022 static int audit_log_single_execve_arg(struct audit_context *context,
1023 					struct audit_buffer **ab,
1024 					int arg_num,
1025 					size_t *len_sent,
1026 					const char __user *p,
1027 					char *buf)
1028 {
1029 	char arg_num_len_buf[12];
1030 	const char __user *tmp_p = p;
1031 	/* how many digits are in arg_num? 5 is the length of ' a=""' */
1032 	size_t arg_num_len = snprintf(arg_num_len_buf, 12, "%d", arg_num) + 5;
1033 	size_t len, len_left, to_send;
1034 	size_t max_execve_audit_len = MAX_EXECVE_AUDIT_LEN;
1035 	unsigned int i, has_cntl = 0, too_long = 0;
1036 	int ret;
1037 
1038 	/* strnlen_user includes the null we don't want to send */
1039 	len_left = len = strnlen_user(p, MAX_ARG_STRLEN) - 1;
1040 
1041 	/*
1042 	 * We just created this mm, if we can't find the strings
1043 	 * we just copied into it something is _very_ wrong. Similar
1044 	 * for strings that are too long, we should not have created
1045 	 * any.
1046 	 */
1047 	if (unlikely((len == -1) || len > MAX_ARG_STRLEN - 1)) {
1048 		WARN_ON(1);
1049 		send_sig(SIGKILL, current, 0);
1050 		return -1;
1051 	}
1052 
1053 	/* walk the whole argument looking for non-ascii chars */
1054 	do {
1055 		if (len_left > MAX_EXECVE_AUDIT_LEN)
1056 			to_send = MAX_EXECVE_AUDIT_LEN;
1057 		else
1058 			to_send = len_left;
1059 		ret = copy_from_user(buf, tmp_p, to_send);
1060 		/*
1061 		 * There is no reason for this copy to be short. We just
1062 		 * copied them here, and the mm hasn't been exposed to user-
1063 		 * space yet.
1064 		 */
1065 		if (ret) {
1066 			WARN_ON(1);
1067 			send_sig(SIGKILL, current, 0);
1068 			return -1;
1069 		}
1070 		buf[to_send] = '\0';
1071 		has_cntl = audit_string_contains_control(buf, to_send);
1072 		if (has_cntl) {
1073 			/*
1074 			 * hex messages get logged as 2 bytes, so we can only
1075 			 * send half as much in each message
1076 			 */
1077 			max_execve_audit_len = MAX_EXECVE_AUDIT_LEN / 2;
1078 			break;
1079 		}
1080 		len_left -= to_send;
1081 		tmp_p += to_send;
1082 	} while (len_left > 0);
1083 
1084 	len_left = len;
1085 
1086 	if (len > max_execve_audit_len)
1087 		too_long = 1;
1088 
1089 	/* rewalk the argument actually logging the message */
1090 	for (i = 0; len_left > 0; i++) {
1091 		int room_left;
1092 
1093 		if (len_left > max_execve_audit_len)
1094 			to_send = max_execve_audit_len;
1095 		else
1096 			to_send = len_left;
1097 
1098 		/* do we have space left to send this argument in this ab? */
1099 		room_left = MAX_EXECVE_AUDIT_LEN - arg_num_len - *len_sent;
1100 		if (has_cntl)
1101 			room_left -= (to_send * 2);
1102 		else
1103 			room_left -= to_send;
1104 		if (room_left < 0) {
1105 			*len_sent = 0;
1106 			audit_log_end(*ab);
1107 			*ab = audit_log_start(context, GFP_KERNEL, AUDIT_EXECVE);
1108 			if (!*ab)
1109 				return 0;
1110 		}
1111 
1112 		/*
1113 		 * first record needs to say how long the original string was
1114 		 * so we can be sure nothing was lost.
1115 		 */
1116 		if ((i == 0) && (too_long))
1117 			audit_log_format(*ab, " a%d_len=%zu", arg_num,
1118 					 has_cntl ? 2*len : len);
1119 
1120 		/*
1121 		 * normally arguments are small enough to fit and we already
1122 		 * filled buf above when we checked for control characters
1123 		 * so don't bother with another copy_from_user
1124 		 */
1125 		if (len >= max_execve_audit_len)
1126 			ret = copy_from_user(buf, p, to_send);
1127 		else
1128 			ret = 0;
1129 		if (ret) {
1130 			WARN_ON(1);
1131 			send_sig(SIGKILL, current, 0);
1132 			return -1;
1133 		}
1134 		buf[to_send] = '\0';
1135 
1136 		/* actually log it */
1137 		audit_log_format(*ab, " a%d", arg_num);
1138 		if (too_long)
1139 			audit_log_format(*ab, "[%d]", i);
1140 		audit_log_format(*ab, "=");
1141 		if (has_cntl)
1142 			audit_log_n_hex(*ab, buf, to_send);
1143 		else
1144 			audit_log_string(*ab, buf);
1145 
1146 		p += to_send;
1147 		len_left -= to_send;
1148 		*len_sent += arg_num_len;
1149 		if (has_cntl)
1150 			*len_sent += to_send * 2;
1151 		else
1152 			*len_sent += to_send;
1153 	}
1154 	/* include the null we didn't log */
1155 	return len + 1;
1156 }
1157 
audit_log_execve_info(struct audit_context * context,struct audit_buffer ** ab,struct audit_aux_data_execve * axi)1158 static void audit_log_execve_info(struct audit_context *context,
1159 				  struct audit_buffer **ab,
1160 				  struct audit_aux_data_execve *axi)
1161 {
1162 	int i;
1163 	size_t len, len_sent = 0;
1164 	const char __user *p;
1165 	char *buf;
1166 
1167 	if (axi->mm != current->mm)
1168 		return; /* execve failed, no additional info */
1169 
1170 	p = (const char __user *)axi->mm->arg_start;
1171 
1172 	audit_log_format(*ab, "argc=%d", axi->argc);
1173 
1174 	/*
1175 	 * we need some kernel buffer to hold the userspace args.  Just
1176 	 * allocate one big one rather than allocating one of the right size
1177 	 * for every single argument inside audit_log_single_execve_arg()
1178 	 * should be <8k allocation so should be pretty safe.
1179 	 */
1180 	buf = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL);
1181 	if (!buf) {
1182 		audit_panic("out of memory for argv string\n");
1183 		return;
1184 	}
1185 
1186 	for (i = 0; i < axi->argc; i++) {
1187 		len = audit_log_single_execve_arg(context, ab, i,
1188 						  &len_sent, p, buf);
1189 		if (len <= 0)
1190 			break;
1191 		p += len;
1192 	}
1193 	kfree(buf);
1194 }
1195 
audit_log_cap(struct audit_buffer * ab,char * prefix,kernel_cap_t * cap)1196 static void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
1197 {
1198 	int i;
1199 
1200 	audit_log_format(ab, " %s=", prefix);
1201 	CAP_FOR_EACH_U32(i) {
1202 		audit_log_format(ab, "%08x", cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]);
1203 	}
1204 }
1205 
audit_log_fcaps(struct audit_buffer * ab,struct audit_names * name)1206 static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
1207 {
1208 	kernel_cap_t *perm = &name->fcap.permitted;
1209 	kernel_cap_t *inh = &name->fcap.inheritable;
1210 	int log = 0;
1211 
1212 	if (!cap_isclear(*perm)) {
1213 		audit_log_cap(ab, "cap_fp", perm);
1214 		log = 1;
1215 	}
1216 	if (!cap_isclear(*inh)) {
1217 		audit_log_cap(ab, "cap_fi", inh);
1218 		log = 1;
1219 	}
1220 
1221 	if (log)
1222 		audit_log_format(ab, " cap_fe=%d cap_fver=%x", name->fcap.fE, name->fcap_ver);
1223 }
1224 
show_special(struct audit_context * context,int * call_panic)1225 static void show_special(struct audit_context *context, int *call_panic)
1226 {
1227 	struct audit_buffer *ab;
1228 	int i;
1229 
1230 	ab = audit_log_start(context, GFP_KERNEL, context->type);
1231 	if (!ab)
1232 		return;
1233 
1234 	switch (context->type) {
1235 	case AUDIT_SOCKETCALL: {
1236 		int nargs = context->socketcall.nargs;
1237 		audit_log_format(ab, "nargs=%d", nargs);
1238 		for (i = 0; i < nargs; i++)
1239 			audit_log_format(ab, " a%d=%lx", i,
1240 				context->socketcall.args[i]);
1241 		break; }
1242 	case AUDIT_IPC: {
1243 		u32 osid = context->ipc.osid;
1244 
1245 		audit_log_format(ab, "ouid=%u ogid=%u mode=%#o",
1246 			 context->ipc.uid, context->ipc.gid, context->ipc.mode);
1247 		if (osid) {
1248 			char *ctx = NULL;
1249 			u32 len;
1250 			if (security_secid_to_secctx(osid, &ctx, &len)) {
1251 				audit_log_format(ab, " osid=%u", osid);
1252 				*call_panic = 1;
1253 			} else {
1254 				audit_log_format(ab, " obj=%s", ctx);
1255 				security_release_secctx(ctx, len);
1256 			}
1257 		}
1258 		if (context->ipc.has_perm) {
1259 			audit_log_end(ab);
1260 			ab = audit_log_start(context, GFP_KERNEL,
1261 					     AUDIT_IPC_SET_PERM);
1262 			audit_log_format(ab,
1263 				"qbytes=%lx ouid=%u ogid=%u mode=%#o",
1264 				context->ipc.qbytes,
1265 				context->ipc.perm_uid,
1266 				context->ipc.perm_gid,
1267 				context->ipc.perm_mode);
1268 			if (!ab)
1269 				return;
1270 		}
1271 		break; }
1272 	case AUDIT_MQ_OPEN: {
1273 		audit_log_format(ab,
1274 			"oflag=0x%x mode=%#o mq_flags=0x%lx mq_maxmsg=%ld "
1275 			"mq_msgsize=%ld mq_curmsgs=%ld",
1276 			context->mq_open.oflag, context->mq_open.mode,
1277 			context->mq_open.attr.mq_flags,
1278 			context->mq_open.attr.mq_maxmsg,
1279 			context->mq_open.attr.mq_msgsize,
1280 			context->mq_open.attr.mq_curmsgs);
1281 		break; }
1282 	case AUDIT_MQ_SENDRECV: {
1283 		audit_log_format(ab,
1284 			"mqdes=%d msg_len=%zd msg_prio=%u "
1285 			"abs_timeout_sec=%ld abs_timeout_nsec=%ld",
1286 			context->mq_sendrecv.mqdes,
1287 			context->mq_sendrecv.msg_len,
1288 			context->mq_sendrecv.msg_prio,
1289 			context->mq_sendrecv.abs_timeout.tv_sec,
1290 			context->mq_sendrecv.abs_timeout.tv_nsec);
1291 		break; }
1292 	case AUDIT_MQ_NOTIFY: {
1293 		audit_log_format(ab, "mqdes=%d sigev_signo=%d",
1294 				context->mq_notify.mqdes,
1295 				context->mq_notify.sigev_signo);
1296 		break; }
1297 	case AUDIT_MQ_GETSETATTR: {
1298 		struct mq_attr *attr = &context->mq_getsetattr.mqstat;
1299 		audit_log_format(ab,
1300 			"mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
1301 			"mq_curmsgs=%ld ",
1302 			context->mq_getsetattr.mqdes,
1303 			attr->mq_flags, attr->mq_maxmsg,
1304 			attr->mq_msgsize, attr->mq_curmsgs);
1305 		break; }
1306 	case AUDIT_CAPSET: {
1307 		audit_log_format(ab, "pid=%d", context->capset.pid);
1308 		audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable);
1309 		audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted);
1310 		audit_log_cap(ab, "cap_pe", &context->capset.cap.effective);
1311 		break; }
1312 	case AUDIT_MMAP: {
1313 		audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd,
1314 				 context->mmap.flags);
1315 		break; }
1316 	}
1317 	audit_log_end(ab);
1318 }
1319 
audit_log_exit(struct audit_context * context,struct task_struct * tsk)1320 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
1321 {
1322 	const struct cred *cred;
1323 	int i, call_panic = 0;
1324 	struct audit_buffer *ab;
1325 	struct audit_aux_data *aux;
1326 	const char *tty;
1327 
1328 	/* tsk == current */
1329 	context->pid = tsk->pid;
1330 	if (!context->ppid)
1331 		context->ppid = sys_getppid();
1332 	cred = current_cred();
1333 	context->uid   = cred->uid;
1334 	context->gid   = cred->gid;
1335 	context->euid  = cred->euid;
1336 	context->suid  = cred->suid;
1337 	context->fsuid = cred->fsuid;
1338 	context->egid  = cred->egid;
1339 	context->sgid  = cred->sgid;
1340 	context->fsgid = cred->fsgid;
1341 	context->personality = tsk->personality;
1342 
1343 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
1344 	if (!ab)
1345 		return;		/* audit_panic has been called */
1346 	audit_log_format(ab, "arch=%x syscall=%d",
1347 			 context->arch, context->major);
1348 	if (context->personality != PER_LINUX)
1349 		audit_log_format(ab, " per=%lx", context->personality);
1350 	if (context->return_valid)
1351 		audit_log_format(ab, " success=%s exit=%ld",
1352 				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
1353 				 context->return_code);
1354 
1355 	spin_lock_irq(&tsk->sighand->siglock);
1356 	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
1357 		tty = tsk->signal->tty->name;
1358 	else
1359 		tty = "(none)";
1360 	spin_unlock_irq(&tsk->sighand->siglock);
1361 
1362 	audit_log_format(ab,
1363 		  " a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
1364 		  " ppid=%d pid=%d auid=%u uid=%u gid=%u"
1365 		  " euid=%u suid=%u fsuid=%u"
1366 		  " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
1367 		  context->argv[0],
1368 		  context->argv[1],
1369 		  context->argv[2],
1370 		  context->argv[3],
1371 		  context->name_count,
1372 		  context->ppid,
1373 		  context->pid,
1374 		  tsk->loginuid,
1375 		  context->uid,
1376 		  context->gid,
1377 		  context->euid, context->suid, context->fsuid,
1378 		  context->egid, context->sgid, context->fsgid, tty,
1379 		  tsk->sessionid);
1380 
1381 
1382 	audit_log_task_info(ab, tsk);
1383 	audit_log_key(ab, context->filterkey);
1384 	audit_log_end(ab);
1385 
1386 	for (aux = context->aux; aux; aux = aux->next) {
1387 
1388 		ab = audit_log_start(context, GFP_KERNEL, aux->type);
1389 		if (!ab)
1390 			continue; /* audit_panic has been called */
1391 
1392 		switch (aux->type) {
1393 
1394 		case AUDIT_EXECVE: {
1395 			struct audit_aux_data_execve *axi = (void *)aux;
1396 			audit_log_execve_info(context, &ab, axi);
1397 			break; }
1398 
1399 		case AUDIT_BPRM_FCAPS: {
1400 			struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
1401 			audit_log_format(ab, "fver=%x", axs->fcap_ver);
1402 			audit_log_cap(ab, "fp", &axs->fcap.permitted);
1403 			audit_log_cap(ab, "fi", &axs->fcap.inheritable);
1404 			audit_log_format(ab, " fe=%d", axs->fcap.fE);
1405 			audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted);
1406 			audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable);
1407 			audit_log_cap(ab, "old_pe", &axs->old_pcap.effective);
1408 			audit_log_cap(ab, "new_pp", &axs->new_pcap.permitted);
1409 			audit_log_cap(ab, "new_pi", &axs->new_pcap.inheritable);
1410 			audit_log_cap(ab, "new_pe", &axs->new_pcap.effective);
1411 			break; }
1412 
1413 		}
1414 		audit_log_end(ab);
1415 	}
1416 
1417 	if (context->type)
1418 		show_special(context, &call_panic);
1419 
1420 	if (context->fds[0] >= 0) {
1421 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR);
1422 		if (ab) {
1423 			audit_log_format(ab, "fd0=%d fd1=%d",
1424 					context->fds[0], context->fds[1]);
1425 			audit_log_end(ab);
1426 		}
1427 	}
1428 
1429 	if (context->sockaddr_len) {
1430 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
1431 		if (ab) {
1432 			audit_log_format(ab, "saddr=");
1433 			audit_log_n_hex(ab, (void *)context->sockaddr,
1434 					context->sockaddr_len);
1435 			audit_log_end(ab);
1436 		}
1437 	}
1438 
1439 	for (aux = context->aux_pids; aux; aux = aux->next) {
1440 		struct audit_aux_data_pids *axs = (void *)aux;
1441 
1442 		for (i = 0; i < axs->pid_count; i++)
1443 			if (audit_log_pid_context(context, axs->target_pid[i],
1444 						  axs->target_auid[i],
1445 						  axs->target_uid[i],
1446 						  axs->target_sessionid[i],
1447 						  axs->target_sid[i],
1448 						  axs->target_comm[i]))
1449 				call_panic = 1;
1450 	}
1451 
1452 	if (context->target_pid &&
1453 	    audit_log_pid_context(context, context->target_pid,
1454 				  context->target_auid, context->target_uid,
1455 				  context->target_sessionid,
1456 				  context->target_sid, context->target_comm))
1457 			call_panic = 1;
1458 
1459 	if (context->pwd.dentry && context->pwd.mnt) {
1460 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
1461 		if (ab) {
1462 			audit_log_d_path(ab, "cwd=", &context->pwd);
1463 			audit_log_end(ab);
1464 		}
1465 	}
1466 	for (i = 0; i < context->name_count; i++) {
1467 		struct audit_names *n = &context->names[i];
1468 
1469 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
1470 		if (!ab)
1471 			continue; /* audit_panic has been called */
1472 
1473 		audit_log_format(ab, "item=%d", i);
1474 
1475 		if (n->name) {
1476 			switch(n->name_len) {
1477 			case AUDIT_NAME_FULL:
1478 				/* log the full path */
1479 				audit_log_format(ab, " name=");
1480 				audit_log_untrustedstring(ab, n->name);
1481 				break;
1482 			case 0:
1483 				/* name was specified as a relative path and the
1484 				 * directory component is the cwd */
1485 				audit_log_d_path(ab, "name=", &context->pwd);
1486 				break;
1487 			default:
1488 				/* log the name's directory component */
1489 				audit_log_format(ab, " name=");
1490 				audit_log_n_untrustedstring(ab, n->name,
1491 							    n->name_len);
1492 			}
1493 		} else
1494 			audit_log_format(ab, " name=(null)");
1495 
1496 		if (n->ino != (unsigned long)-1) {
1497 			audit_log_format(ab, " inode=%lu"
1498 					 " dev=%02x:%02x mode=%#o"
1499 					 " ouid=%u ogid=%u rdev=%02x:%02x",
1500 					 n->ino,
1501 					 MAJOR(n->dev),
1502 					 MINOR(n->dev),
1503 					 n->mode,
1504 					 n->uid,
1505 					 n->gid,
1506 					 MAJOR(n->rdev),
1507 					 MINOR(n->rdev));
1508 		}
1509 		if (n->osid != 0) {
1510 			char *ctx = NULL;
1511 			u32 len;
1512 			if (security_secid_to_secctx(
1513 				n->osid, &ctx, &len)) {
1514 				audit_log_format(ab, " osid=%u", n->osid);
1515 				call_panic = 2;
1516 			} else {
1517 				audit_log_format(ab, " obj=%s", ctx);
1518 				security_release_secctx(ctx, len);
1519 			}
1520 		}
1521 
1522 		audit_log_fcaps(ab, n);
1523 
1524 		audit_log_end(ab);
1525 	}
1526 
1527 	/* Send end of event record to help user space know we are finished */
1528 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
1529 	if (ab)
1530 		audit_log_end(ab);
1531 	if (call_panic)
1532 		audit_panic("error converting sid to string");
1533 }
1534 
1535 /**
1536  * audit_free - free a per-task audit context
1537  * @tsk: task whose audit context block to free
1538  *
1539  * Called from copy_process and do_exit
1540  */
audit_free(struct task_struct * tsk)1541 void audit_free(struct task_struct *tsk)
1542 {
1543 	struct audit_context *context;
1544 
1545 	context = audit_get_context(tsk, 0, 0);
1546 	if (likely(!context))
1547 		return;
1548 
1549 	/* Check for system calls that do not go through the exit
1550 	 * function (e.g., exit_group), then free context block.
1551 	 * We use GFP_ATOMIC here because we might be doing this
1552 	 * in the context of the idle thread */
1553 	/* that can happen only if we are called from do_exit() */
1554 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1555 		audit_log_exit(context, tsk);
1556 	if (!list_empty(&context->killed_trees))
1557 		audit_kill_trees(&context->killed_trees);
1558 
1559 	audit_free_context(context);
1560 }
1561 
1562 /**
1563  * audit_syscall_entry - fill in an audit record at syscall entry
1564  * @arch: architecture type
1565  * @major: major syscall type (function)
1566  * @a1: additional syscall register 1
1567  * @a2: additional syscall register 2
1568  * @a3: additional syscall register 3
1569  * @a4: additional syscall register 4
1570  *
1571  * Fill in audit context at syscall entry.  This only happens if the
1572  * audit context was created when the task was created and the state or
1573  * filters demand the audit context be built.  If the state from the
1574  * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1575  * then the record will be written at syscall exit time (otherwise, it
1576  * will only be written if another part of the kernel requests that it
1577  * be written).
1578  */
audit_syscall_entry(int arch,int major,unsigned long a1,unsigned long a2,unsigned long a3,unsigned long a4)1579 void audit_syscall_entry(int arch, int major,
1580 			 unsigned long a1, unsigned long a2,
1581 			 unsigned long a3, unsigned long a4)
1582 {
1583 	struct task_struct *tsk = current;
1584 	struct audit_context *context = tsk->audit_context;
1585 	enum audit_state     state;
1586 
1587 	if (unlikely(!context))
1588 		return;
1589 
1590 	/*
1591 	 * This happens only on certain architectures that make system
1592 	 * calls in kernel_thread via the entry.S interface, instead of
1593 	 * with direct calls.  (If you are porting to a new
1594 	 * architecture, hitting this condition can indicate that you
1595 	 * got the _exit/_leave calls backward in entry.S.)
1596 	 *
1597 	 * i386     no
1598 	 * x86_64   no
1599 	 * ppc64    yes (see arch/powerpc/platforms/iseries/misc.S)
1600 	 *
1601 	 * This also happens with vm86 emulation in a non-nested manner
1602 	 * (entries without exits), so this case must be caught.
1603 	 */
1604 	if (context->in_syscall) {
1605 		struct audit_context *newctx;
1606 
1607 #if AUDIT_DEBUG
1608 		printk(KERN_ERR
1609 		       "audit(:%d) pid=%d in syscall=%d;"
1610 		       " entering syscall=%d\n",
1611 		       context->serial, tsk->pid, context->major, major);
1612 #endif
1613 		newctx = audit_alloc_context(context->state);
1614 		if (newctx) {
1615 			newctx->previous   = context;
1616 			context		   = newctx;
1617 			tsk->audit_context = newctx;
1618 		} else	{
1619 			/* If we can't alloc a new context, the best we
1620 			 * can do is to leak memory (any pending putname
1621 			 * will be lost).  The only other alternative is
1622 			 * to abandon auditing. */
1623 			audit_zero_context(context, context->state);
1624 		}
1625 	}
1626 	BUG_ON(context->in_syscall || context->name_count);
1627 
1628 	if (!audit_enabled)
1629 		return;
1630 
1631 	context->arch	    = arch;
1632 	context->major      = major;
1633 	context->argv[0]    = a1;
1634 	context->argv[1]    = a2;
1635 	context->argv[2]    = a3;
1636 	context->argv[3]    = a4;
1637 
1638 	state = context->state;
1639 	context->dummy = !audit_n_rules;
1640 	if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
1641 		context->prio = 0;
1642 		state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
1643 	}
1644 	if (likely(state == AUDIT_DISABLED))
1645 		return;
1646 
1647 	context->serial     = 0;
1648 	context->ctime      = CURRENT_TIME;
1649 	context->in_syscall = 1;
1650 	context->current_state  = state;
1651 	context->ppid       = 0;
1652 }
1653 
audit_finish_fork(struct task_struct * child)1654 void audit_finish_fork(struct task_struct *child)
1655 {
1656 	struct audit_context *ctx = current->audit_context;
1657 	struct audit_context *p = child->audit_context;
1658 	if (!p || !ctx)
1659 		return;
1660 	if (!ctx->in_syscall || ctx->current_state != AUDIT_RECORD_CONTEXT)
1661 		return;
1662 	p->arch = ctx->arch;
1663 	p->major = ctx->major;
1664 	memcpy(p->argv, ctx->argv, sizeof(ctx->argv));
1665 	p->ctime = ctx->ctime;
1666 	p->dummy = ctx->dummy;
1667 	p->in_syscall = ctx->in_syscall;
1668 	p->filterkey = kstrdup(ctx->filterkey, GFP_KERNEL);
1669 	p->ppid = current->pid;
1670 	p->prio = ctx->prio;
1671 	p->current_state = ctx->current_state;
1672 }
1673 
1674 /**
1675  * audit_syscall_exit - deallocate audit context after a system call
1676  * @valid: success/failure flag
1677  * @return_code: syscall return value
1678  *
1679  * Tear down after system call.  If the audit context has been marked as
1680  * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1681  * filtering, or because some other part of the kernel write an audit
1682  * message), then write out the syscall information.  In call cases,
1683  * free the names stored from getname().
1684  */
audit_syscall_exit(int valid,long return_code)1685 void audit_syscall_exit(int valid, long return_code)
1686 {
1687 	struct task_struct *tsk = current;
1688 	struct audit_context *context;
1689 
1690 	context = audit_get_context(tsk, valid, return_code);
1691 
1692 	if (likely(!context))
1693 		return;
1694 
1695 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1696 		audit_log_exit(context, tsk);
1697 
1698 	context->in_syscall = 0;
1699 	context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
1700 
1701 	if (!list_empty(&context->killed_trees))
1702 		audit_kill_trees(&context->killed_trees);
1703 
1704 	if (context->previous) {
1705 		struct audit_context *new_context = context->previous;
1706 		context->previous  = NULL;
1707 		audit_free_context(context);
1708 		tsk->audit_context = new_context;
1709 	} else {
1710 		audit_free_names(context);
1711 		unroll_tree_refs(context, NULL, 0);
1712 		audit_free_aux(context);
1713 		context->aux = NULL;
1714 		context->aux_pids = NULL;
1715 		context->target_pid = 0;
1716 		context->target_sid = 0;
1717 		context->sockaddr_len = 0;
1718 		context->type = 0;
1719 		context->fds[0] = -1;
1720 		if (context->state != AUDIT_RECORD_CONTEXT) {
1721 			kfree(context->filterkey);
1722 			context->filterkey = NULL;
1723 		}
1724 		tsk->audit_context = context;
1725 	}
1726 }
1727 
handle_one(const struct inode * inode)1728 static inline void handle_one(const struct inode *inode)
1729 {
1730 #ifdef CONFIG_AUDIT_TREE
1731 	struct audit_context *context;
1732 	struct audit_tree_refs *p;
1733 	struct audit_chunk *chunk;
1734 	int count;
1735 	if (likely(hlist_empty(&inode->i_fsnotify_marks)))
1736 		return;
1737 	context = current->audit_context;
1738 	p = context->trees;
1739 	count = context->tree_count;
1740 	rcu_read_lock();
1741 	chunk = audit_tree_lookup(inode);
1742 	rcu_read_unlock();
1743 	if (!chunk)
1744 		return;
1745 	if (likely(put_tree_ref(context, chunk)))
1746 		return;
1747 	if (unlikely(!grow_tree_refs(context))) {
1748 		printk(KERN_WARNING "out of memory, audit has lost a tree reference\n");
1749 		audit_set_auditable(context);
1750 		audit_put_chunk(chunk);
1751 		unroll_tree_refs(context, p, count);
1752 		return;
1753 	}
1754 	put_tree_ref(context, chunk);
1755 #endif
1756 }
1757 
handle_path(const struct dentry * dentry)1758 static void handle_path(const struct dentry *dentry)
1759 {
1760 #ifdef CONFIG_AUDIT_TREE
1761 	struct audit_context *context;
1762 	struct audit_tree_refs *p;
1763 	const struct dentry *d, *parent;
1764 	struct audit_chunk *drop;
1765 	unsigned long seq;
1766 	int count;
1767 
1768 	context = current->audit_context;
1769 	p = context->trees;
1770 	count = context->tree_count;
1771 retry:
1772 	drop = NULL;
1773 	d = dentry;
1774 	rcu_read_lock();
1775 	seq = read_seqbegin(&rename_lock);
1776 	for(;;) {
1777 		struct inode *inode = d->d_inode;
1778 		if (inode && unlikely(!hlist_empty(&inode->i_fsnotify_marks))) {
1779 			struct audit_chunk *chunk;
1780 			chunk = audit_tree_lookup(inode);
1781 			if (chunk) {
1782 				if (unlikely(!put_tree_ref(context, chunk))) {
1783 					drop = chunk;
1784 					break;
1785 				}
1786 			}
1787 		}
1788 		parent = d->d_parent;
1789 		if (parent == d)
1790 			break;
1791 		d = parent;
1792 	}
1793 	if (unlikely(read_seqretry(&rename_lock, seq) || drop)) {  /* in this order */
1794 		rcu_read_unlock();
1795 		if (!drop) {
1796 			/* just a race with rename */
1797 			unroll_tree_refs(context, p, count);
1798 			goto retry;
1799 		}
1800 		audit_put_chunk(drop);
1801 		if (grow_tree_refs(context)) {
1802 			/* OK, got more space */
1803 			unroll_tree_refs(context, p, count);
1804 			goto retry;
1805 		}
1806 		/* too bad */
1807 		printk(KERN_WARNING
1808 			"out of memory, audit has lost a tree reference\n");
1809 		unroll_tree_refs(context, p, count);
1810 		audit_set_auditable(context);
1811 		return;
1812 	}
1813 	rcu_read_unlock();
1814 #endif
1815 }
1816 
1817 /**
1818  * audit_getname - add a name to the list
1819  * @name: name to add
1820  *
1821  * Add a name to the list of audit names for this context.
1822  * Called from fs/namei.c:getname().
1823  */
__audit_getname(const char * name)1824 void __audit_getname(const char *name)
1825 {
1826 	struct audit_context *context = current->audit_context;
1827 
1828 	if (IS_ERR(name) || !name)
1829 		return;
1830 
1831 	if (!context->in_syscall) {
1832 #if AUDIT_DEBUG == 2
1833 		printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)\n",
1834 		       __FILE__, __LINE__, context->serial, name);
1835 		dump_stack();
1836 #endif
1837 		return;
1838 	}
1839 	BUG_ON(context->name_count >= AUDIT_NAMES);
1840 	context->names[context->name_count].name = name;
1841 	context->names[context->name_count].name_len = AUDIT_NAME_FULL;
1842 	context->names[context->name_count].name_put = 1;
1843 	context->names[context->name_count].ino  = (unsigned long)-1;
1844 	context->names[context->name_count].osid = 0;
1845 	++context->name_count;
1846 	if (!context->pwd.dentry)
1847 		get_fs_pwd(current->fs, &context->pwd);
1848 }
1849 
1850 /* audit_putname - intercept a putname request
1851  * @name: name to intercept and delay for putname
1852  *
1853  * If we have stored the name from getname in the audit context,
1854  * then we delay the putname until syscall exit.
1855  * Called from include/linux/fs.h:putname().
1856  */
audit_putname(const char * name)1857 void audit_putname(const char *name)
1858 {
1859 	struct audit_context *context = current->audit_context;
1860 
1861 	BUG_ON(!context);
1862 	if (!context->in_syscall) {
1863 #if AUDIT_DEBUG == 2
1864 		printk(KERN_ERR "%s:%d(:%d): __putname(%p)\n",
1865 		       __FILE__, __LINE__, context->serial, name);
1866 		if (context->name_count) {
1867 			int i;
1868 			for (i = 0; i < context->name_count; i++)
1869 				printk(KERN_ERR "name[%d] = %p = %s\n", i,
1870 				       context->names[i].name,
1871 				       context->names[i].name ?: "(null)");
1872 		}
1873 #endif
1874 		__putname(name);
1875 	}
1876 #if AUDIT_DEBUG
1877 	else {
1878 		++context->put_count;
1879 		if (context->put_count > context->name_count) {
1880 			printk(KERN_ERR "%s:%d(:%d): major=%d"
1881 			       " in_syscall=%d putname(%p) name_count=%d"
1882 			       " put_count=%d\n",
1883 			       __FILE__, __LINE__,
1884 			       context->serial, context->major,
1885 			       context->in_syscall, name, context->name_count,
1886 			       context->put_count);
1887 			dump_stack();
1888 		}
1889 	}
1890 #endif
1891 }
1892 
audit_inc_name_count(struct audit_context * context,const struct inode * inode)1893 static int audit_inc_name_count(struct audit_context *context,
1894 				const struct inode *inode)
1895 {
1896 	if (context->name_count >= AUDIT_NAMES) {
1897 		if (inode)
1898 			printk(KERN_DEBUG "audit: name_count maxed, losing inode data: "
1899 			       "dev=%02x:%02x, inode=%lu\n",
1900 			       MAJOR(inode->i_sb->s_dev),
1901 			       MINOR(inode->i_sb->s_dev),
1902 			       inode->i_ino);
1903 
1904 		else
1905 			printk(KERN_DEBUG "name_count maxed, losing inode data\n");
1906 		return 1;
1907 	}
1908 	context->name_count++;
1909 #if AUDIT_DEBUG
1910 	context->ino_count++;
1911 #endif
1912 	return 0;
1913 }
1914 
1915 
audit_copy_fcaps(struct audit_names * name,const struct dentry * dentry)1916 static inline int audit_copy_fcaps(struct audit_names *name, const struct dentry *dentry)
1917 {
1918 	struct cpu_vfs_cap_data caps;
1919 	int rc;
1920 
1921 	memset(&name->fcap.permitted, 0, sizeof(kernel_cap_t));
1922 	memset(&name->fcap.inheritable, 0, sizeof(kernel_cap_t));
1923 	name->fcap.fE = 0;
1924 	name->fcap_ver = 0;
1925 
1926 	if (!dentry)
1927 		return 0;
1928 
1929 	rc = get_vfs_caps_from_disk(dentry, &caps);
1930 	if (rc)
1931 		return rc;
1932 
1933 	name->fcap.permitted = caps.permitted;
1934 	name->fcap.inheritable = caps.inheritable;
1935 	name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
1936 	name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
1937 
1938 	return 0;
1939 }
1940 
1941 
1942 /* Copy inode data into an audit_names. */
audit_copy_inode(struct audit_names * name,const struct dentry * dentry,const struct inode * inode)1943 static void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
1944 			     const struct inode *inode)
1945 {
1946 	name->ino   = inode->i_ino;
1947 	name->dev   = inode->i_sb->s_dev;
1948 	name->mode  = inode->i_mode;
1949 	name->uid   = inode->i_uid;
1950 	name->gid   = inode->i_gid;
1951 	name->rdev  = inode->i_rdev;
1952 	security_inode_getsecid(inode, &name->osid);
1953 	audit_copy_fcaps(name, dentry);
1954 }
1955 
1956 /**
1957  * audit_inode - store the inode and device from a lookup
1958  * @name: name being audited
1959  * @dentry: dentry being audited
1960  *
1961  * Called from fs/namei.c:path_lookup().
1962  */
__audit_inode(const char * name,const struct dentry * dentry)1963 void __audit_inode(const char *name, const struct dentry *dentry)
1964 {
1965 	int idx;
1966 	struct audit_context *context = current->audit_context;
1967 	const struct inode *inode = dentry->d_inode;
1968 
1969 	if (!context->in_syscall)
1970 		return;
1971 	if (context->name_count
1972 	    && context->names[context->name_count-1].name
1973 	    && context->names[context->name_count-1].name == name)
1974 		idx = context->name_count - 1;
1975 	else if (context->name_count > 1
1976 		 && context->names[context->name_count-2].name
1977 		 && context->names[context->name_count-2].name == name)
1978 		idx = context->name_count - 2;
1979 	else {
1980 		/* FIXME: how much do we care about inodes that have no
1981 		 * associated name? */
1982 		if (audit_inc_name_count(context, inode))
1983 			return;
1984 		idx = context->name_count - 1;
1985 		context->names[idx].name = NULL;
1986 	}
1987 	handle_path(dentry);
1988 	audit_copy_inode(&context->names[idx], dentry, inode);
1989 }
1990 
1991 /**
1992  * audit_inode_child - collect inode info for created/removed objects
1993  * @dentry: dentry being audited
1994  * @parent: inode of dentry parent
1995  *
1996  * For syscalls that create or remove filesystem objects, audit_inode
1997  * can only collect information for the filesystem object's parent.
1998  * This call updates the audit context with the child's information.
1999  * Syscalls that create a new filesystem object must be hooked after
2000  * the object is created.  Syscalls that remove a filesystem object
2001  * must be hooked prior, in order to capture the target inode during
2002  * unsuccessful attempts.
2003  */
__audit_inode_child(const struct dentry * dentry,const struct inode * parent)2004 void __audit_inode_child(const struct dentry *dentry,
2005 			 const struct inode *parent)
2006 {
2007 	int idx;
2008 	struct audit_context *context = current->audit_context;
2009 	const char *found_parent = NULL, *found_child = NULL;
2010 	const struct inode *inode = dentry->d_inode;
2011 	const char *dname = dentry->d_name.name;
2012 	int dirlen = 0;
2013 
2014 	if (!context->in_syscall)
2015 		return;
2016 
2017 	if (inode)
2018 		handle_one(inode);
2019 
2020 	/* parent is more likely, look for it first */
2021 	for (idx = 0; idx < context->name_count; idx++) {
2022 		struct audit_names *n = &context->names[idx];
2023 
2024 		if (!n->name)
2025 			continue;
2026 
2027 		if (n->ino == parent->i_ino &&
2028 		    !audit_compare_dname_path(dname, n->name, &dirlen)) {
2029 			n->name_len = dirlen; /* update parent data in place */
2030 			found_parent = n->name;
2031 			goto add_names;
2032 		}
2033 	}
2034 
2035 	/* no matching parent, look for matching child */
2036 	for (idx = 0; idx < context->name_count; idx++) {
2037 		struct audit_names *n = &context->names[idx];
2038 
2039 		if (!n->name)
2040 			continue;
2041 
2042 		/* strcmp() is the more likely scenario */
2043 		if (!strcmp(dname, n->name) ||
2044 		     !audit_compare_dname_path(dname, n->name, &dirlen)) {
2045 			if (inode)
2046 				audit_copy_inode(n, NULL, inode);
2047 			else
2048 				n->ino = (unsigned long)-1;
2049 			found_child = n->name;
2050 			goto add_names;
2051 		}
2052 	}
2053 
2054 add_names:
2055 	if (!found_parent) {
2056 		if (audit_inc_name_count(context, parent))
2057 			return;
2058 		idx = context->name_count - 1;
2059 		context->names[idx].name = NULL;
2060 		audit_copy_inode(&context->names[idx], NULL, parent);
2061 	}
2062 
2063 	if (!found_child) {
2064 		if (audit_inc_name_count(context, inode))
2065 			return;
2066 		idx = context->name_count - 1;
2067 
2068 		/* Re-use the name belonging to the slot for a matching parent
2069 		 * directory. All names for this context are relinquished in
2070 		 * audit_free_names() */
2071 		if (found_parent) {
2072 			context->names[idx].name = found_parent;
2073 			context->names[idx].name_len = AUDIT_NAME_FULL;
2074 			/* don't call __putname() */
2075 			context->names[idx].name_put = 0;
2076 		} else {
2077 			context->names[idx].name = NULL;
2078 		}
2079 
2080 		if (inode)
2081 			audit_copy_inode(&context->names[idx], NULL, inode);
2082 		else
2083 			context->names[idx].ino = (unsigned long)-1;
2084 	}
2085 }
2086 EXPORT_SYMBOL_GPL(__audit_inode_child);
2087 
2088 /**
2089  * auditsc_get_stamp - get local copies of audit_context values
2090  * @ctx: audit_context for the task
2091  * @t: timespec to store time recorded in the audit_context
2092  * @serial: serial value that is recorded in the audit_context
2093  *
2094  * Also sets the context as auditable.
2095  */
auditsc_get_stamp(struct audit_context * ctx,struct timespec * t,unsigned int * serial)2096 int auditsc_get_stamp(struct audit_context *ctx,
2097 		       struct timespec *t, unsigned int *serial)
2098 {
2099 	if (!ctx->in_syscall)
2100 		return 0;
2101 	if (!ctx->serial)
2102 		ctx->serial = audit_serial();
2103 	t->tv_sec  = ctx->ctime.tv_sec;
2104 	t->tv_nsec = ctx->ctime.tv_nsec;
2105 	*serial    = ctx->serial;
2106 	if (!ctx->prio) {
2107 		ctx->prio = 1;
2108 		ctx->current_state = AUDIT_RECORD_CONTEXT;
2109 	}
2110 	return 1;
2111 }
2112 
2113 /* global counter which is incremented every time something logs in */
2114 static atomic_t session_id = ATOMIC_INIT(0);
2115 
2116 /**
2117  * audit_set_loginuid - set a task's audit_context loginuid
2118  * @task: task whose audit context is being modified
2119  * @loginuid: loginuid value
2120  *
2121  * Returns 0.
2122  *
2123  * Called (set) from fs/proc/base.c::proc_loginuid_write().
2124  */
audit_set_loginuid(struct task_struct * task,uid_t loginuid)2125 int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
2126 {
2127 	unsigned int sessionid = atomic_inc_return(&session_id);
2128 	struct audit_context *context = task->audit_context;
2129 
2130 	if (context && context->in_syscall) {
2131 		struct audit_buffer *ab;
2132 
2133 		ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
2134 		if (ab) {
2135 			audit_log_format(ab, "login pid=%d uid=%u "
2136 				"old auid=%u new auid=%u"
2137 				" old ses=%u new ses=%u",
2138 				task->pid, task_uid(task),
2139 				task->loginuid, loginuid,
2140 				task->sessionid, sessionid);
2141 			audit_log_end(ab);
2142 		}
2143 	}
2144 	task->sessionid = sessionid;
2145 	task->loginuid = loginuid;
2146 	return 0;
2147 }
2148 
2149 /**
2150  * __audit_mq_open - record audit data for a POSIX MQ open
2151  * @oflag: open flag
2152  * @mode: mode bits
2153  * @attr: queue attributes
2154  *
2155  */
__audit_mq_open(int oflag,mode_t mode,struct mq_attr * attr)2156 void __audit_mq_open(int oflag, mode_t mode, struct mq_attr *attr)
2157 {
2158 	struct audit_context *context = current->audit_context;
2159 
2160 	if (attr)
2161 		memcpy(&context->mq_open.attr, attr, sizeof(struct mq_attr));
2162 	else
2163 		memset(&context->mq_open.attr, 0, sizeof(struct mq_attr));
2164 
2165 	context->mq_open.oflag = oflag;
2166 	context->mq_open.mode = mode;
2167 
2168 	context->type = AUDIT_MQ_OPEN;
2169 }
2170 
2171 /**
2172  * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive
2173  * @mqdes: MQ descriptor
2174  * @msg_len: Message length
2175  * @msg_prio: Message priority
2176  * @abs_timeout: Message timeout in absolute time
2177  *
2178  */
__audit_mq_sendrecv(mqd_t mqdes,size_t msg_len,unsigned int msg_prio,const struct timespec * abs_timeout)2179 void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
2180 			const struct timespec *abs_timeout)
2181 {
2182 	struct audit_context *context = current->audit_context;
2183 	struct timespec *p = &context->mq_sendrecv.abs_timeout;
2184 
2185 	if (abs_timeout)
2186 		memcpy(p, abs_timeout, sizeof(struct timespec));
2187 	else
2188 		memset(p, 0, sizeof(struct timespec));
2189 
2190 	context->mq_sendrecv.mqdes = mqdes;
2191 	context->mq_sendrecv.msg_len = msg_len;
2192 	context->mq_sendrecv.msg_prio = msg_prio;
2193 
2194 	context->type = AUDIT_MQ_SENDRECV;
2195 }
2196 
2197 /**
2198  * __audit_mq_notify - record audit data for a POSIX MQ notify
2199  * @mqdes: MQ descriptor
2200  * @notification: Notification event
2201  *
2202  */
2203 
__audit_mq_notify(mqd_t mqdes,const struct sigevent * notification)2204 void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
2205 {
2206 	struct audit_context *context = current->audit_context;
2207 
2208 	if (notification)
2209 		context->mq_notify.sigev_signo = notification->sigev_signo;
2210 	else
2211 		context->mq_notify.sigev_signo = 0;
2212 
2213 	context->mq_notify.mqdes = mqdes;
2214 	context->type = AUDIT_MQ_NOTIFY;
2215 }
2216 
2217 /**
2218  * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
2219  * @mqdes: MQ descriptor
2220  * @mqstat: MQ flags
2221  *
2222  */
__audit_mq_getsetattr(mqd_t mqdes,struct mq_attr * mqstat)2223 void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
2224 {
2225 	struct audit_context *context = current->audit_context;
2226 	context->mq_getsetattr.mqdes = mqdes;
2227 	context->mq_getsetattr.mqstat = *mqstat;
2228 	context->type = AUDIT_MQ_GETSETATTR;
2229 }
2230 
2231 /**
2232  * audit_ipc_obj - record audit data for ipc object
2233  * @ipcp: ipc permissions
2234  *
2235  */
__audit_ipc_obj(struct kern_ipc_perm * ipcp)2236 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
2237 {
2238 	struct audit_context *context = current->audit_context;
2239 	context->ipc.uid = ipcp->uid;
2240 	context->ipc.gid = ipcp->gid;
2241 	context->ipc.mode = ipcp->mode;
2242 	context->ipc.has_perm = 0;
2243 	security_ipc_getsecid(ipcp, &context->ipc.osid);
2244 	context->type = AUDIT_IPC;
2245 }
2246 
2247 /**
2248  * audit_ipc_set_perm - record audit data for new ipc permissions
2249  * @qbytes: msgq bytes
2250  * @uid: msgq user id
2251  * @gid: msgq group id
2252  * @mode: msgq mode (permissions)
2253  *
2254  * Called only after audit_ipc_obj().
2255  */
__audit_ipc_set_perm(unsigned long qbytes,uid_t uid,gid_t gid,mode_t mode)2256 void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
2257 {
2258 	struct audit_context *context = current->audit_context;
2259 
2260 	context->ipc.qbytes = qbytes;
2261 	context->ipc.perm_uid = uid;
2262 	context->ipc.perm_gid = gid;
2263 	context->ipc.perm_mode = mode;
2264 	context->ipc.has_perm = 1;
2265 }
2266 
audit_bprm(struct linux_binprm * bprm)2267 int audit_bprm(struct linux_binprm *bprm)
2268 {
2269 	struct audit_aux_data_execve *ax;
2270 	struct audit_context *context = current->audit_context;
2271 
2272 	if (likely(!audit_enabled || !context || context->dummy))
2273 		return 0;
2274 
2275 	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2276 	if (!ax)
2277 		return -ENOMEM;
2278 
2279 	ax->argc = bprm->argc;
2280 	ax->envc = bprm->envc;
2281 	ax->mm = bprm->mm;
2282 	ax->d.type = AUDIT_EXECVE;
2283 	ax->d.next = context->aux;
2284 	context->aux = (void *)ax;
2285 	return 0;
2286 }
2287 
2288 
2289 /**
2290  * audit_socketcall - record audit data for sys_socketcall
2291  * @nargs: number of args
2292  * @args: args array
2293  *
2294  */
audit_socketcall(int nargs,unsigned long * args)2295 void audit_socketcall(int nargs, unsigned long *args)
2296 {
2297 	struct audit_context *context = current->audit_context;
2298 
2299 	if (likely(!context || context->dummy))
2300 		return;
2301 
2302 	context->type = AUDIT_SOCKETCALL;
2303 	context->socketcall.nargs = nargs;
2304 	memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long));
2305 }
2306 
2307 /**
2308  * __audit_fd_pair - record audit data for pipe and socketpair
2309  * @fd1: the first file descriptor
2310  * @fd2: the second file descriptor
2311  *
2312  */
__audit_fd_pair(int fd1,int fd2)2313 void __audit_fd_pair(int fd1, int fd2)
2314 {
2315 	struct audit_context *context = current->audit_context;
2316 	context->fds[0] = fd1;
2317 	context->fds[1] = fd2;
2318 }
2319 
2320 /**
2321  * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
2322  * @len: data length in user space
2323  * @a: data address in kernel space
2324  *
2325  * Returns 0 for success or NULL context or < 0 on error.
2326  */
audit_sockaddr(int len,void * a)2327 int audit_sockaddr(int len, void *a)
2328 {
2329 	struct audit_context *context = current->audit_context;
2330 
2331 	if (likely(!context || context->dummy))
2332 		return 0;
2333 
2334 	if (!context->sockaddr) {
2335 		void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL);
2336 		if (!p)
2337 			return -ENOMEM;
2338 		context->sockaddr = p;
2339 	}
2340 
2341 	context->sockaddr_len = len;
2342 	memcpy(context->sockaddr, a, len);
2343 	return 0;
2344 }
2345 
__audit_ptrace(struct task_struct * t)2346 void __audit_ptrace(struct task_struct *t)
2347 {
2348 	struct audit_context *context = current->audit_context;
2349 
2350 	context->target_pid = t->pid;
2351 	context->target_auid = audit_get_loginuid(t);
2352 	context->target_uid = task_uid(t);
2353 	context->target_sessionid = audit_get_sessionid(t);
2354 	security_task_getsecid(t, &context->target_sid);
2355 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
2356 }
2357 
2358 /**
2359  * audit_signal_info - record signal info for shutting down audit subsystem
2360  * @sig: signal value
2361  * @t: task being signaled
2362  *
2363  * If the audit subsystem is being terminated, record the task (pid)
2364  * and uid that is doing that.
2365  */
__audit_signal_info(int sig,struct task_struct * t)2366 int __audit_signal_info(int sig, struct task_struct *t)
2367 {
2368 	struct audit_aux_data_pids *axp;
2369 	struct task_struct *tsk = current;
2370 	struct audit_context *ctx = tsk->audit_context;
2371 	uid_t uid = current_uid(), t_uid = task_uid(t);
2372 
2373 	if (audit_pid && t->tgid == audit_pid) {
2374 		if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) {
2375 			audit_sig_pid = tsk->pid;
2376 			if (tsk->loginuid != -1)
2377 				audit_sig_uid = tsk->loginuid;
2378 			else
2379 				audit_sig_uid = uid;
2380 			security_task_getsecid(tsk, &audit_sig_sid);
2381 		}
2382 		if (!audit_signals || audit_dummy_context())
2383 			return 0;
2384 	}
2385 
2386 	/* optimize the common case by putting first signal recipient directly
2387 	 * in audit_context */
2388 	if (!ctx->target_pid) {
2389 		ctx->target_pid = t->tgid;
2390 		ctx->target_auid = audit_get_loginuid(t);
2391 		ctx->target_uid = t_uid;
2392 		ctx->target_sessionid = audit_get_sessionid(t);
2393 		security_task_getsecid(t, &ctx->target_sid);
2394 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
2395 		return 0;
2396 	}
2397 
2398 	axp = (void *)ctx->aux_pids;
2399 	if (!axp || axp->pid_count == AUDIT_AUX_PIDS) {
2400 		axp = kzalloc(sizeof(*axp), GFP_ATOMIC);
2401 		if (!axp)
2402 			return -ENOMEM;
2403 
2404 		axp->d.type = AUDIT_OBJ_PID;
2405 		axp->d.next = ctx->aux_pids;
2406 		ctx->aux_pids = (void *)axp;
2407 	}
2408 	BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);
2409 
2410 	axp->target_pid[axp->pid_count] = t->tgid;
2411 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
2412 	axp->target_uid[axp->pid_count] = t_uid;
2413 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
2414 	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
2415 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
2416 	axp->pid_count++;
2417 
2418 	return 0;
2419 }
2420 
2421 /**
2422  * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps
2423  * @bprm: pointer to the bprm being processed
2424  * @new: the proposed new credentials
2425  * @old: the old credentials
2426  *
2427  * Simply check if the proc already has the caps given by the file and if not
2428  * store the priv escalation info for later auditing at the end of the syscall
2429  *
2430  * -Eric
2431  */
__audit_log_bprm_fcaps(struct linux_binprm * bprm,const struct cred * new,const struct cred * old)2432 int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
2433 			   const struct cred *new, const struct cred *old)
2434 {
2435 	struct audit_aux_data_bprm_fcaps *ax;
2436 	struct audit_context *context = current->audit_context;
2437 	struct cpu_vfs_cap_data vcaps;
2438 	struct dentry *dentry;
2439 
2440 	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2441 	if (!ax)
2442 		return -ENOMEM;
2443 
2444 	ax->d.type = AUDIT_BPRM_FCAPS;
2445 	ax->d.next = context->aux;
2446 	context->aux = (void *)ax;
2447 
2448 	dentry = dget(bprm->file->f_dentry);
2449 	get_vfs_caps_from_disk(dentry, &vcaps);
2450 	dput(dentry);
2451 
2452 	ax->fcap.permitted = vcaps.permitted;
2453 	ax->fcap.inheritable = vcaps.inheritable;
2454 	ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2455 	ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
2456 
2457 	ax->old_pcap.permitted   = old->cap_permitted;
2458 	ax->old_pcap.inheritable = old->cap_inheritable;
2459 	ax->old_pcap.effective   = old->cap_effective;
2460 
2461 	ax->new_pcap.permitted   = new->cap_permitted;
2462 	ax->new_pcap.inheritable = new->cap_inheritable;
2463 	ax->new_pcap.effective   = new->cap_effective;
2464 	return 0;
2465 }
2466 
2467 /**
2468  * __audit_log_capset - store information about the arguments to the capset syscall
2469  * @pid: target pid of the capset call
2470  * @new: the new credentials
2471  * @old: the old (current) credentials
2472  *
2473  * Record the aguments userspace sent to sys_capset for later printing by the
2474  * audit system if applicable
2475  */
__audit_log_capset(pid_t pid,const struct cred * new,const struct cred * old)2476 void __audit_log_capset(pid_t pid,
2477 		       const struct cred *new, const struct cred *old)
2478 {
2479 	struct audit_context *context = current->audit_context;
2480 	context->capset.pid = pid;
2481 	context->capset.cap.effective   = new->cap_effective;
2482 	context->capset.cap.inheritable = new->cap_effective;
2483 	context->capset.cap.permitted   = new->cap_permitted;
2484 	context->type = AUDIT_CAPSET;
2485 }
2486 
__audit_mmap_fd(int fd,int flags)2487 void __audit_mmap_fd(int fd, int flags)
2488 {
2489 	struct audit_context *context = current->audit_context;
2490 	context->mmap.fd = fd;
2491 	context->mmap.flags = flags;
2492 	context->type = AUDIT_MMAP;
2493 }
2494 
2495 /**
2496  * audit_core_dumps - record information about processes that end abnormally
2497  * @signr: signal value
2498  *
2499  * If a process ends with a core dump, something fishy is going on and we
2500  * should record the event for investigation.
2501  */
audit_core_dumps(long signr)2502 void audit_core_dumps(long signr)
2503 {
2504 	struct audit_buffer *ab;
2505 	u32 sid;
2506 	uid_t auid = audit_get_loginuid(current), uid;
2507 	gid_t gid;
2508 	unsigned int sessionid = audit_get_sessionid(current);
2509 
2510 	if (!audit_enabled)
2511 		return;
2512 
2513 	if (signr == SIGQUIT)	/* don't care for those */
2514 		return;
2515 
2516 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
2517 	current_uid_gid(&uid, &gid);
2518 	audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
2519 			 auid, uid, gid, sessionid);
2520 	security_task_getsecid(current, &sid);
2521 	if (sid) {
2522 		char *ctx = NULL;
2523 		u32 len;
2524 
2525 		if (security_secid_to_secctx(sid, &ctx, &len))
2526 			audit_log_format(ab, " ssid=%u", sid);
2527 		else {
2528 			audit_log_format(ab, " subj=%s", ctx);
2529 			security_release_secctx(ctx, len);
2530 		}
2531 	}
2532 	audit_log_format(ab, " pid=%d comm=", current->pid);
2533 	audit_log_untrustedstring(ab, current->comm);
2534 	audit_log_format(ab, " sig=%ld", signr);
2535 	audit_log_end(ab);
2536 }
2537 
audit_killed_trees(void)2538 struct list_head *audit_killed_trees(void)
2539 {
2540 	struct audit_context *ctx = current->audit_context;
2541 	if (likely(!ctx || !ctx->in_syscall))
2542 		return NULL;
2543 	return &ctx->killed_trees;
2544 }
2545