xref: /openbmc/linux/kernel/auditsc.c (revision b6dcefde)
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/mount.h>
53 #include <linux/socket.h>
54 #include <linux/mqueue.h>
55 #include <linux/audit.h>
56 #include <linux/personality.h>
57 #include <linux/time.h>
58 #include <linux/netlink.h>
59 #include <linux/compiler.h>
60 #include <asm/unistd.h>
61 #include <linux/security.h>
62 #include <linux/list.h>
63 #include <linux/tty.h>
64 #include <linux/binfmts.h>
65 #include <linux/highmem.h>
66 #include <linux/syscalls.h>
67 #include <linux/inotify.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 	};
245 	int fds[2];
246 
247 #if AUDIT_DEBUG
248 	int		    put_count;
249 	int		    ino_count;
250 #endif
251 };
252 
253 static inline int open_arg(int flags, int mask)
254 {
255 	int n = ACC_MODE(flags);
256 	if (flags & (O_TRUNC | O_CREAT))
257 		n |= AUDIT_PERM_WRITE;
258 	return n & mask;
259 }
260 
261 static int audit_match_perm(struct audit_context *ctx, int mask)
262 {
263 	unsigned n;
264 	if (unlikely(!ctx))
265 		return 0;
266 	n = ctx->major;
267 
268 	switch (audit_classify_syscall(ctx->arch, n)) {
269 	case 0:	/* native */
270 		if ((mask & AUDIT_PERM_WRITE) &&
271 		     audit_match_class(AUDIT_CLASS_WRITE, n))
272 			return 1;
273 		if ((mask & AUDIT_PERM_READ) &&
274 		     audit_match_class(AUDIT_CLASS_READ, n))
275 			return 1;
276 		if ((mask & AUDIT_PERM_ATTR) &&
277 		     audit_match_class(AUDIT_CLASS_CHATTR, n))
278 			return 1;
279 		return 0;
280 	case 1: /* 32bit on biarch */
281 		if ((mask & AUDIT_PERM_WRITE) &&
282 		     audit_match_class(AUDIT_CLASS_WRITE_32, n))
283 			return 1;
284 		if ((mask & AUDIT_PERM_READ) &&
285 		     audit_match_class(AUDIT_CLASS_READ_32, n))
286 			return 1;
287 		if ((mask & AUDIT_PERM_ATTR) &&
288 		     audit_match_class(AUDIT_CLASS_CHATTR_32, n))
289 			return 1;
290 		return 0;
291 	case 2: /* open */
292 		return mask & ACC_MODE(ctx->argv[1]);
293 	case 3: /* openat */
294 		return mask & ACC_MODE(ctx->argv[2]);
295 	case 4: /* socketcall */
296 		return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND);
297 	case 5: /* execve */
298 		return mask & AUDIT_PERM_EXEC;
299 	default:
300 		return 0;
301 	}
302 }
303 
304 static int audit_match_filetype(struct audit_context *ctx, int which)
305 {
306 	unsigned index = which & ~S_IFMT;
307 	mode_t mode = which & S_IFMT;
308 
309 	if (unlikely(!ctx))
310 		return 0;
311 
312 	if (index >= ctx->name_count)
313 		return 0;
314 	if (ctx->names[index].ino == -1)
315 		return 0;
316 	if ((ctx->names[index].mode ^ mode) & S_IFMT)
317 		return 0;
318 	return 1;
319 }
320 
321 /*
322  * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
323  * ->first_trees points to its beginning, ->trees - to the current end of data.
324  * ->tree_count is the number of free entries in array pointed to by ->trees.
325  * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
326  * "empty" becomes (p, p, 31) afterwards.  We don't shrink the list (and seriously,
327  * it's going to remain 1-element for almost any setup) until we free context itself.
328  * References in it _are_ dropped - at the same time we free/drop aux stuff.
329  */
330 
331 #ifdef CONFIG_AUDIT_TREE
332 static void audit_set_auditable(struct audit_context *ctx)
333 {
334 	if (!ctx->prio) {
335 		ctx->prio = 1;
336 		ctx->current_state = AUDIT_RECORD_CONTEXT;
337 	}
338 }
339 
340 static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
341 {
342 	struct audit_tree_refs *p = ctx->trees;
343 	int left = ctx->tree_count;
344 	if (likely(left)) {
345 		p->c[--left] = chunk;
346 		ctx->tree_count = left;
347 		return 1;
348 	}
349 	if (!p)
350 		return 0;
351 	p = p->next;
352 	if (p) {
353 		p->c[30] = chunk;
354 		ctx->trees = p;
355 		ctx->tree_count = 30;
356 		return 1;
357 	}
358 	return 0;
359 }
360 
361 static int grow_tree_refs(struct audit_context *ctx)
362 {
363 	struct audit_tree_refs *p = ctx->trees;
364 	ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
365 	if (!ctx->trees) {
366 		ctx->trees = p;
367 		return 0;
368 	}
369 	if (p)
370 		p->next = ctx->trees;
371 	else
372 		ctx->first_trees = ctx->trees;
373 	ctx->tree_count = 31;
374 	return 1;
375 }
376 #endif
377 
378 static void unroll_tree_refs(struct audit_context *ctx,
379 		      struct audit_tree_refs *p, int count)
380 {
381 #ifdef CONFIG_AUDIT_TREE
382 	struct audit_tree_refs *q;
383 	int n;
384 	if (!p) {
385 		/* we started with empty chain */
386 		p = ctx->first_trees;
387 		count = 31;
388 		/* if the very first allocation has failed, nothing to do */
389 		if (!p)
390 			return;
391 	}
392 	n = count;
393 	for (q = p; q != ctx->trees; q = q->next, n = 31) {
394 		while (n--) {
395 			audit_put_chunk(q->c[n]);
396 			q->c[n] = NULL;
397 		}
398 	}
399 	while (n-- > ctx->tree_count) {
400 		audit_put_chunk(q->c[n]);
401 		q->c[n] = NULL;
402 	}
403 	ctx->trees = p;
404 	ctx->tree_count = count;
405 #endif
406 }
407 
408 static void free_tree_refs(struct audit_context *ctx)
409 {
410 	struct audit_tree_refs *p, *q;
411 	for (p = ctx->first_trees; p; p = q) {
412 		q = p->next;
413 		kfree(p);
414 	}
415 }
416 
417 static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
418 {
419 #ifdef CONFIG_AUDIT_TREE
420 	struct audit_tree_refs *p;
421 	int n;
422 	if (!tree)
423 		return 0;
424 	/* full ones */
425 	for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
426 		for (n = 0; n < 31; n++)
427 			if (audit_tree_match(p->c[n], tree))
428 				return 1;
429 	}
430 	/* partial */
431 	if (p) {
432 		for (n = ctx->tree_count; n < 31; n++)
433 			if (audit_tree_match(p->c[n], tree))
434 				return 1;
435 	}
436 #endif
437 	return 0;
438 }
439 
440 /* Determine if any context name data matches a rule's watch data */
441 /* Compare a task_struct with an audit_rule.  Return 1 on match, 0
442  * otherwise. */
443 static int audit_filter_rules(struct task_struct *tsk,
444 			      struct audit_krule *rule,
445 			      struct audit_context *ctx,
446 			      struct audit_names *name,
447 			      enum audit_state *state)
448 {
449 	const struct cred *cred = get_task_cred(tsk);
450 	int i, j, need_sid = 1;
451 	u32 sid;
452 
453 	for (i = 0; i < rule->field_count; i++) {
454 		struct audit_field *f = &rule->fields[i];
455 		int result = 0;
456 
457 		switch (f->type) {
458 		case AUDIT_PID:
459 			result = audit_comparator(tsk->pid, f->op, f->val);
460 			break;
461 		case AUDIT_PPID:
462 			if (ctx) {
463 				if (!ctx->ppid)
464 					ctx->ppid = sys_getppid();
465 				result = audit_comparator(ctx->ppid, f->op, f->val);
466 			}
467 			break;
468 		case AUDIT_UID:
469 			result = audit_comparator(cred->uid, f->op, f->val);
470 			break;
471 		case AUDIT_EUID:
472 			result = audit_comparator(cred->euid, f->op, f->val);
473 			break;
474 		case AUDIT_SUID:
475 			result = audit_comparator(cred->suid, f->op, f->val);
476 			break;
477 		case AUDIT_FSUID:
478 			result = audit_comparator(cred->fsuid, f->op, f->val);
479 			break;
480 		case AUDIT_GID:
481 			result = audit_comparator(cred->gid, f->op, f->val);
482 			break;
483 		case AUDIT_EGID:
484 			result = audit_comparator(cred->egid, f->op, f->val);
485 			break;
486 		case AUDIT_SGID:
487 			result = audit_comparator(cred->sgid, f->op, f->val);
488 			break;
489 		case AUDIT_FSGID:
490 			result = audit_comparator(cred->fsgid, f->op, f->val);
491 			break;
492 		case AUDIT_PERS:
493 			result = audit_comparator(tsk->personality, f->op, f->val);
494 			break;
495 		case AUDIT_ARCH:
496 			if (ctx)
497 				result = audit_comparator(ctx->arch, f->op, f->val);
498 			break;
499 
500 		case AUDIT_EXIT:
501 			if (ctx && ctx->return_valid)
502 				result = audit_comparator(ctx->return_code, f->op, f->val);
503 			break;
504 		case AUDIT_SUCCESS:
505 			if (ctx && ctx->return_valid) {
506 				if (f->val)
507 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
508 				else
509 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);
510 			}
511 			break;
512 		case AUDIT_DEVMAJOR:
513 			if (name)
514 				result = audit_comparator(MAJOR(name->dev),
515 							  f->op, f->val);
516 			else if (ctx) {
517 				for (j = 0; j < ctx->name_count; j++) {
518 					if (audit_comparator(MAJOR(ctx->names[j].dev),	f->op, f->val)) {
519 						++result;
520 						break;
521 					}
522 				}
523 			}
524 			break;
525 		case AUDIT_DEVMINOR:
526 			if (name)
527 				result = audit_comparator(MINOR(name->dev),
528 							  f->op, f->val);
529 			else if (ctx) {
530 				for (j = 0; j < ctx->name_count; j++) {
531 					if (audit_comparator(MINOR(ctx->names[j].dev), f->op, f->val)) {
532 						++result;
533 						break;
534 					}
535 				}
536 			}
537 			break;
538 		case AUDIT_INODE:
539 			if (name)
540 				result = (name->ino == f->val);
541 			else if (ctx) {
542 				for (j = 0; j < ctx->name_count; j++) {
543 					if (audit_comparator(ctx->names[j].ino, f->op, f->val)) {
544 						++result;
545 						break;
546 					}
547 				}
548 			}
549 			break;
550 		case AUDIT_WATCH:
551 			if (name && audit_watch_inode(rule->watch) != (unsigned long)-1)
552 				result = (name->dev == audit_watch_dev(rule->watch) &&
553 					  name->ino == audit_watch_inode(rule->watch));
554 			break;
555 		case AUDIT_DIR:
556 			if (ctx)
557 				result = match_tree_refs(ctx, rule->tree);
558 			break;
559 		case AUDIT_LOGINUID:
560 			result = 0;
561 			if (ctx)
562 				result = audit_comparator(tsk->loginuid, f->op, f->val);
563 			break;
564 		case AUDIT_SUBJ_USER:
565 		case AUDIT_SUBJ_ROLE:
566 		case AUDIT_SUBJ_TYPE:
567 		case AUDIT_SUBJ_SEN:
568 		case AUDIT_SUBJ_CLR:
569 			/* NOTE: this may return negative values indicating
570 			   a temporary error.  We simply treat this as a
571 			   match for now to avoid losing information that
572 			   may be wanted.   An error message will also be
573 			   logged upon error */
574 			if (f->lsm_rule) {
575 				if (need_sid) {
576 					security_task_getsecid(tsk, &sid);
577 					need_sid = 0;
578 				}
579 				result = security_audit_rule_match(sid, f->type,
580 				                                  f->op,
581 				                                  f->lsm_rule,
582 				                                  ctx);
583 			}
584 			break;
585 		case AUDIT_OBJ_USER:
586 		case AUDIT_OBJ_ROLE:
587 		case AUDIT_OBJ_TYPE:
588 		case AUDIT_OBJ_LEV_LOW:
589 		case AUDIT_OBJ_LEV_HIGH:
590 			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
591 			   also applies here */
592 			if (f->lsm_rule) {
593 				/* Find files that match */
594 				if (name) {
595 					result = security_audit_rule_match(
596 					           name->osid, f->type, f->op,
597 					           f->lsm_rule, ctx);
598 				} else if (ctx) {
599 					for (j = 0; j < ctx->name_count; j++) {
600 						if (security_audit_rule_match(
601 						      ctx->names[j].osid,
602 						      f->type, f->op,
603 						      f->lsm_rule, ctx)) {
604 							++result;
605 							break;
606 						}
607 					}
608 				}
609 				/* Find ipc objects that match */
610 				if (!ctx || ctx->type != AUDIT_IPC)
611 					break;
612 				if (security_audit_rule_match(ctx->ipc.osid,
613 							      f->type, f->op,
614 							      f->lsm_rule, ctx))
615 					++result;
616 			}
617 			break;
618 		case AUDIT_ARG0:
619 		case AUDIT_ARG1:
620 		case AUDIT_ARG2:
621 		case AUDIT_ARG3:
622 			if (ctx)
623 				result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
624 			break;
625 		case AUDIT_FILTERKEY:
626 			/* ignore this field for filtering */
627 			result = 1;
628 			break;
629 		case AUDIT_PERM:
630 			result = audit_match_perm(ctx, f->val);
631 			break;
632 		case AUDIT_FILETYPE:
633 			result = audit_match_filetype(ctx, f->val);
634 			break;
635 		}
636 
637 		if (!result) {
638 			put_cred(cred);
639 			return 0;
640 		}
641 	}
642 
643 	if (ctx) {
644 		if (rule->prio <= ctx->prio)
645 			return 0;
646 		if (rule->filterkey) {
647 			kfree(ctx->filterkey);
648 			ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
649 		}
650 		ctx->prio = rule->prio;
651 	}
652 	switch (rule->action) {
653 	case AUDIT_NEVER:    *state = AUDIT_DISABLED;	    break;
654 	case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
655 	}
656 	put_cred(cred);
657 	return 1;
658 }
659 
660 /* At process creation time, we can determine if system-call auditing is
661  * completely disabled for this task.  Since we only have the task
662  * structure at this point, we can only check uid and gid.
663  */
664 static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
665 {
666 	struct audit_entry *e;
667 	enum audit_state   state;
668 
669 	rcu_read_lock();
670 	list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
671 		if (audit_filter_rules(tsk, &e->rule, NULL, NULL, &state)) {
672 			if (state == AUDIT_RECORD_CONTEXT)
673 				*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
674 			rcu_read_unlock();
675 			return state;
676 		}
677 	}
678 	rcu_read_unlock();
679 	return AUDIT_BUILD_CONTEXT;
680 }
681 
682 /* At syscall entry and exit time, this filter is called if the
683  * audit_state is not low enough that auditing cannot take place, but is
684  * also not high enough that we already know we have to write an audit
685  * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
686  */
687 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
688 					     struct audit_context *ctx,
689 					     struct list_head *list)
690 {
691 	struct audit_entry *e;
692 	enum audit_state state;
693 
694 	if (audit_pid && tsk->tgid == audit_pid)
695 		return AUDIT_DISABLED;
696 
697 	rcu_read_lock();
698 	if (!list_empty(list)) {
699 		int word = AUDIT_WORD(ctx->major);
700 		int bit  = AUDIT_BIT(ctx->major);
701 
702 		list_for_each_entry_rcu(e, list, list) {
703 			if ((e->rule.mask[word] & bit) == bit &&
704 			    audit_filter_rules(tsk, &e->rule, ctx, NULL,
705 					       &state)) {
706 				rcu_read_unlock();
707 				ctx->current_state = state;
708 				return state;
709 			}
710 		}
711 	}
712 	rcu_read_unlock();
713 	return AUDIT_BUILD_CONTEXT;
714 }
715 
716 /* At syscall exit time, this filter is called if any audit_names[] have been
717  * collected during syscall processing.  We only check rules in sublists at hash
718  * buckets applicable to the inode numbers in audit_names[].
719  * Regarding audit_state, same rules apply as for audit_filter_syscall().
720  */
721 void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
722 {
723 	int i;
724 	struct audit_entry *e;
725 	enum audit_state state;
726 
727 	if (audit_pid && tsk->tgid == audit_pid)
728 		return;
729 
730 	rcu_read_lock();
731 	for (i = 0; i < ctx->name_count; i++) {
732 		int word = AUDIT_WORD(ctx->major);
733 		int bit  = AUDIT_BIT(ctx->major);
734 		struct audit_names *n = &ctx->names[i];
735 		int h = audit_hash_ino((u32)n->ino);
736 		struct list_head *list = &audit_inode_hash[h];
737 
738 		if (list_empty(list))
739 			continue;
740 
741 		list_for_each_entry_rcu(e, list, list) {
742 			if ((e->rule.mask[word] & bit) == bit &&
743 			    audit_filter_rules(tsk, &e->rule, ctx, n, &state)) {
744 				rcu_read_unlock();
745 				ctx->current_state = state;
746 				return;
747 			}
748 		}
749 	}
750 	rcu_read_unlock();
751 }
752 
753 static inline struct audit_context *audit_get_context(struct task_struct *tsk,
754 						      int return_valid,
755 						      long return_code)
756 {
757 	struct audit_context *context = tsk->audit_context;
758 
759 	if (likely(!context))
760 		return NULL;
761 	context->return_valid = return_valid;
762 
763 	/*
764 	 * we need to fix up the return code in the audit logs if the actual
765 	 * return codes are later going to be fixed up by the arch specific
766 	 * signal handlers
767 	 *
768 	 * This is actually a test for:
769 	 * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) ||
770 	 * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK)
771 	 *
772 	 * but is faster than a bunch of ||
773 	 */
774 	if (unlikely(return_code <= -ERESTARTSYS) &&
775 	    (return_code >= -ERESTART_RESTARTBLOCK) &&
776 	    (return_code != -ENOIOCTLCMD))
777 		context->return_code = -EINTR;
778 	else
779 		context->return_code  = return_code;
780 
781 	if (context->in_syscall && !context->dummy) {
782 		audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
783 		audit_filter_inodes(tsk, context);
784 	}
785 
786 	tsk->audit_context = NULL;
787 	return context;
788 }
789 
790 static inline void audit_free_names(struct audit_context *context)
791 {
792 	int i;
793 
794 #if AUDIT_DEBUG == 2
795 	if (context->put_count + context->ino_count != context->name_count) {
796 		printk(KERN_ERR "%s:%d(:%d): major=%d in_syscall=%d"
797 		       " name_count=%d put_count=%d"
798 		       " ino_count=%d [NOT freeing]\n",
799 		       __FILE__, __LINE__,
800 		       context->serial, context->major, context->in_syscall,
801 		       context->name_count, context->put_count,
802 		       context->ino_count);
803 		for (i = 0; i < context->name_count; i++) {
804 			printk(KERN_ERR "names[%d] = %p = %s\n", i,
805 			       context->names[i].name,
806 			       context->names[i].name ?: "(null)");
807 		}
808 		dump_stack();
809 		return;
810 	}
811 #endif
812 #if AUDIT_DEBUG
813 	context->put_count  = 0;
814 	context->ino_count  = 0;
815 #endif
816 
817 	for (i = 0; i < context->name_count; i++) {
818 		if (context->names[i].name && context->names[i].name_put)
819 			__putname(context->names[i].name);
820 	}
821 	context->name_count = 0;
822 	path_put(&context->pwd);
823 	context->pwd.dentry = NULL;
824 	context->pwd.mnt = NULL;
825 }
826 
827 static inline void audit_free_aux(struct audit_context *context)
828 {
829 	struct audit_aux_data *aux;
830 
831 	while ((aux = context->aux)) {
832 		context->aux = aux->next;
833 		kfree(aux);
834 	}
835 	while ((aux = context->aux_pids)) {
836 		context->aux_pids = aux->next;
837 		kfree(aux);
838 	}
839 }
840 
841 static inline void audit_zero_context(struct audit_context *context,
842 				      enum audit_state state)
843 {
844 	memset(context, 0, sizeof(*context));
845 	context->state      = state;
846 	context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
847 }
848 
849 static inline struct audit_context *audit_alloc_context(enum audit_state state)
850 {
851 	struct audit_context *context;
852 
853 	if (!(context = kmalloc(sizeof(*context), GFP_KERNEL)))
854 		return NULL;
855 	audit_zero_context(context, state);
856 	INIT_LIST_HEAD(&context->killed_trees);
857 	return context;
858 }
859 
860 /**
861  * audit_alloc - allocate an audit context block for a task
862  * @tsk: task
863  *
864  * Filter on the task information and allocate a per-task audit context
865  * if necessary.  Doing so turns on system call auditing for the
866  * specified task.  This is called from copy_process, so no lock is
867  * needed.
868  */
869 int audit_alloc(struct task_struct *tsk)
870 {
871 	struct audit_context *context;
872 	enum audit_state     state;
873 	char *key = NULL;
874 
875 	if (likely(!audit_ever_enabled))
876 		return 0; /* Return if not auditing. */
877 
878 	state = audit_filter_task(tsk, &key);
879 	if (likely(state == AUDIT_DISABLED))
880 		return 0;
881 
882 	if (!(context = audit_alloc_context(state))) {
883 		kfree(key);
884 		audit_log_lost("out of memory in audit_alloc");
885 		return -ENOMEM;
886 	}
887 	context->filterkey = key;
888 
889 	tsk->audit_context  = context;
890 	set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
891 	return 0;
892 }
893 
894 static inline void audit_free_context(struct audit_context *context)
895 {
896 	struct audit_context *previous;
897 	int		     count = 0;
898 
899 	do {
900 		previous = context->previous;
901 		if (previous || (count &&  count < 10)) {
902 			++count;
903 			printk(KERN_ERR "audit(:%d): major=%d name_count=%d:"
904 			       " freeing multiple contexts (%d)\n",
905 			       context->serial, context->major,
906 			       context->name_count, count);
907 		}
908 		audit_free_names(context);
909 		unroll_tree_refs(context, NULL, 0);
910 		free_tree_refs(context);
911 		audit_free_aux(context);
912 		kfree(context->filterkey);
913 		kfree(context->sockaddr);
914 		kfree(context);
915 		context  = previous;
916 	} while (context);
917 	if (count >= 10)
918 		printk(KERN_ERR "audit: freed %d contexts\n", count);
919 }
920 
921 void audit_log_task_context(struct audit_buffer *ab)
922 {
923 	char *ctx = NULL;
924 	unsigned len;
925 	int error;
926 	u32 sid;
927 
928 	security_task_getsecid(current, &sid);
929 	if (!sid)
930 		return;
931 
932 	error = security_secid_to_secctx(sid, &ctx, &len);
933 	if (error) {
934 		if (error != -EINVAL)
935 			goto error_path;
936 		return;
937 	}
938 
939 	audit_log_format(ab, " subj=%s", ctx);
940 	security_release_secctx(ctx, len);
941 	return;
942 
943 error_path:
944 	audit_panic("error in audit_log_task_context");
945 	return;
946 }
947 
948 EXPORT_SYMBOL(audit_log_task_context);
949 
950 static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
951 {
952 	char name[sizeof(tsk->comm)];
953 	struct mm_struct *mm = tsk->mm;
954 	struct vm_area_struct *vma;
955 
956 	/* tsk == current */
957 
958 	get_task_comm(name, tsk);
959 	audit_log_format(ab, " comm=");
960 	audit_log_untrustedstring(ab, name);
961 
962 	if (mm) {
963 		down_read(&mm->mmap_sem);
964 		vma = mm->mmap;
965 		while (vma) {
966 			if ((vma->vm_flags & VM_EXECUTABLE) &&
967 			    vma->vm_file) {
968 				audit_log_d_path(ab, "exe=",
969 						 &vma->vm_file->f_path);
970 				break;
971 			}
972 			vma = vma->vm_next;
973 		}
974 		up_read(&mm->mmap_sem);
975 	}
976 	audit_log_task_context(ab);
977 }
978 
979 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
980 				 uid_t auid, uid_t uid, unsigned int sessionid,
981 				 u32 sid, char *comm)
982 {
983 	struct audit_buffer *ab;
984 	char *ctx = NULL;
985 	u32 len;
986 	int rc = 0;
987 
988 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
989 	if (!ab)
990 		return rc;
991 
992 	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid, auid,
993 			 uid, sessionid);
994 	if (security_secid_to_secctx(sid, &ctx, &len)) {
995 		audit_log_format(ab, " obj=(none)");
996 		rc = 1;
997 	} else {
998 		audit_log_format(ab, " obj=%s", ctx);
999 		security_release_secctx(ctx, len);
1000 	}
1001 	audit_log_format(ab, " ocomm=");
1002 	audit_log_untrustedstring(ab, comm);
1003 	audit_log_end(ab);
1004 
1005 	return rc;
1006 }
1007 
1008 /*
1009  * to_send and len_sent accounting are very loose estimates.  We aren't
1010  * really worried about a hard cap to MAX_EXECVE_AUDIT_LEN so much as being
1011  * within about 500 bytes (next page boundry)
1012  *
1013  * why snprintf?  an int is up to 12 digits long.  if we just assumed when
1014  * logging that a[%d]= was going to be 16 characters long we would be wasting
1015  * space in every audit message.  In one 7500 byte message we can log up to
1016  * about 1000 min size arguments.  That comes down to about 50% waste of space
1017  * if we didn't do the snprintf to find out how long arg_num_len was.
1018  */
1019 static int audit_log_single_execve_arg(struct audit_context *context,
1020 					struct audit_buffer **ab,
1021 					int arg_num,
1022 					size_t *len_sent,
1023 					const char __user *p,
1024 					char *buf)
1025 {
1026 	char arg_num_len_buf[12];
1027 	const char __user *tmp_p = p;
1028 	/* how many digits are in arg_num? 5 is the length of ' a=""' */
1029 	size_t arg_num_len = snprintf(arg_num_len_buf, 12, "%d", arg_num) + 5;
1030 	size_t len, len_left, to_send;
1031 	size_t max_execve_audit_len = MAX_EXECVE_AUDIT_LEN;
1032 	unsigned int i, has_cntl = 0, too_long = 0;
1033 	int ret;
1034 
1035 	/* strnlen_user includes the null we don't want to send */
1036 	len_left = len = strnlen_user(p, MAX_ARG_STRLEN) - 1;
1037 
1038 	/*
1039 	 * We just created this mm, if we can't find the strings
1040 	 * we just copied into it something is _very_ wrong. Similar
1041 	 * for strings that are too long, we should not have created
1042 	 * any.
1043 	 */
1044 	if (unlikely((len == -1) || len > MAX_ARG_STRLEN - 1)) {
1045 		WARN_ON(1);
1046 		send_sig(SIGKILL, current, 0);
1047 		return -1;
1048 	}
1049 
1050 	/* walk the whole argument looking for non-ascii chars */
1051 	do {
1052 		if (len_left > MAX_EXECVE_AUDIT_LEN)
1053 			to_send = MAX_EXECVE_AUDIT_LEN;
1054 		else
1055 			to_send = len_left;
1056 		ret = copy_from_user(buf, tmp_p, to_send);
1057 		/*
1058 		 * There is no reason for this copy to be short. We just
1059 		 * copied them here, and the mm hasn't been exposed to user-
1060 		 * space yet.
1061 		 */
1062 		if (ret) {
1063 			WARN_ON(1);
1064 			send_sig(SIGKILL, current, 0);
1065 			return -1;
1066 		}
1067 		buf[to_send] = '\0';
1068 		has_cntl = audit_string_contains_control(buf, to_send);
1069 		if (has_cntl) {
1070 			/*
1071 			 * hex messages get logged as 2 bytes, so we can only
1072 			 * send half as much in each message
1073 			 */
1074 			max_execve_audit_len = MAX_EXECVE_AUDIT_LEN / 2;
1075 			break;
1076 		}
1077 		len_left -= to_send;
1078 		tmp_p += to_send;
1079 	} while (len_left > 0);
1080 
1081 	len_left = len;
1082 
1083 	if (len > max_execve_audit_len)
1084 		too_long = 1;
1085 
1086 	/* rewalk the argument actually logging the message */
1087 	for (i = 0; len_left > 0; i++) {
1088 		int room_left;
1089 
1090 		if (len_left > max_execve_audit_len)
1091 			to_send = max_execve_audit_len;
1092 		else
1093 			to_send = len_left;
1094 
1095 		/* do we have space left to send this argument in this ab? */
1096 		room_left = MAX_EXECVE_AUDIT_LEN - arg_num_len - *len_sent;
1097 		if (has_cntl)
1098 			room_left -= (to_send * 2);
1099 		else
1100 			room_left -= to_send;
1101 		if (room_left < 0) {
1102 			*len_sent = 0;
1103 			audit_log_end(*ab);
1104 			*ab = audit_log_start(context, GFP_KERNEL, AUDIT_EXECVE);
1105 			if (!*ab)
1106 				return 0;
1107 		}
1108 
1109 		/*
1110 		 * first record needs to say how long the original string was
1111 		 * so we can be sure nothing was lost.
1112 		 */
1113 		if ((i == 0) && (too_long))
1114 			audit_log_format(*ab, " a%d_len=%zu", arg_num,
1115 					 has_cntl ? 2*len : len);
1116 
1117 		/*
1118 		 * normally arguments are small enough to fit and we already
1119 		 * filled buf above when we checked for control characters
1120 		 * so don't bother with another copy_from_user
1121 		 */
1122 		if (len >= max_execve_audit_len)
1123 			ret = copy_from_user(buf, p, to_send);
1124 		else
1125 			ret = 0;
1126 		if (ret) {
1127 			WARN_ON(1);
1128 			send_sig(SIGKILL, current, 0);
1129 			return -1;
1130 		}
1131 		buf[to_send] = '\0';
1132 
1133 		/* actually log it */
1134 		audit_log_format(*ab, " a%d", arg_num);
1135 		if (too_long)
1136 			audit_log_format(*ab, "[%d]", i);
1137 		audit_log_format(*ab, "=");
1138 		if (has_cntl)
1139 			audit_log_n_hex(*ab, buf, to_send);
1140 		else
1141 			audit_log_string(*ab, buf);
1142 
1143 		p += to_send;
1144 		len_left -= to_send;
1145 		*len_sent += arg_num_len;
1146 		if (has_cntl)
1147 			*len_sent += to_send * 2;
1148 		else
1149 			*len_sent += to_send;
1150 	}
1151 	/* include the null we didn't log */
1152 	return len + 1;
1153 }
1154 
1155 static void audit_log_execve_info(struct audit_context *context,
1156 				  struct audit_buffer **ab,
1157 				  struct audit_aux_data_execve *axi)
1158 {
1159 	int i;
1160 	size_t len, len_sent = 0;
1161 	const char __user *p;
1162 	char *buf;
1163 
1164 	if (axi->mm != current->mm)
1165 		return; /* execve failed, no additional info */
1166 
1167 	p = (const char __user *)axi->mm->arg_start;
1168 
1169 	audit_log_format(*ab, "argc=%d", axi->argc);
1170 
1171 	/*
1172 	 * we need some kernel buffer to hold the userspace args.  Just
1173 	 * allocate one big one rather than allocating one of the right size
1174 	 * for every single argument inside audit_log_single_execve_arg()
1175 	 * should be <8k allocation so should be pretty safe.
1176 	 */
1177 	buf = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL);
1178 	if (!buf) {
1179 		audit_panic("out of memory for argv string\n");
1180 		return;
1181 	}
1182 
1183 	for (i = 0; i < axi->argc; i++) {
1184 		len = audit_log_single_execve_arg(context, ab, i,
1185 						  &len_sent, p, buf);
1186 		if (len <= 0)
1187 			break;
1188 		p += len;
1189 	}
1190 	kfree(buf);
1191 }
1192 
1193 static void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
1194 {
1195 	int i;
1196 
1197 	audit_log_format(ab, " %s=", prefix);
1198 	CAP_FOR_EACH_U32(i) {
1199 		audit_log_format(ab, "%08x", cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]);
1200 	}
1201 }
1202 
1203 static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
1204 {
1205 	kernel_cap_t *perm = &name->fcap.permitted;
1206 	kernel_cap_t *inh = &name->fcap.inheritable;
1207 	int log = 0;
1208 
1209 	if (!cap_isclear(*perm)) {
1210 		audit_log_cap(ab, "cap_fp", perm);
1211 		log = 1;
1212 	}
1213 	if (!cap_isclear(*inh)) {
1214 		audit_log_cap(ab, "cap_fi", inh);
1215 		log = 1;
1216 	}
1217 
1218 	if (log)
1219 		audit_log_format(ab, " cap_fe=%d cap_fver=%x", name->fcap.fE, name->fcap_ver);
1220 }
1221 
1222 static void show_special(struct audit_context *context, int *call_panic)
1223 {
1224 	struct audit_buffer *ab;
1225 	int i;
1226 
1227 	ab = audit_log_start(context, GFP_KERNEL, context->type);
1228 	if (!ab)
1229 		return;
1230 
1231 	switch (context->type) {
1232 	case AUDIT_SOCKETCALL: {
1233 		int nargs = context->socketcall.nargs;
1234 		audit_log_format(ab, "nargs=%d", nargs);
1235 		for (i = 0; i < nargs; i++)
1236 			audit_log_format(ab, " a%d=%lx", i,
1237 				context->socketcall.args[i]);
1238 		break; }
1239 	case AUDIT_IPC: {
1240 		u32 osid = context->ipc.osid;
1241 
1242 		audit_log_format(ab, "ouid=%u ogid=%u mode=%#o",
1243 			 context->ipc.uid, context->ipc.gid, context->ipc.mode);
1244 		if (osid) {
1245 			char *ctx = NULL;
1246 			u32 len;
1247 			if (security_secid_to_secctx(osid, &ctx, &len)) {
1248 				audit_log_format(ab, " osid=%u", osid);
1249 				*call_panic = 1;
1250 			} else {
1251 				audit_log_format(ab, " obj=%s", ctx);
1252 				security_release_secctx(ctx, len);
1253 			}
1254 		}
1255 		if (context->ipc.has_perm) {
1256 			audit_log_end(ab);
1257 			ab = audit_log_start(context, GFP_KERNEL,
1258 					     AUDIT_IPC_SET_PERM);
1259 			audit_log_format(ab,
1260 				"qbytes=%lx ouid=%u ogid=%u mode=%#o",
1261 				context->ipc.qbytes,
1262 				context->ipc.perm_uid,
1263 				context->ipc.perm_gid,
1264 				context->ipc.perm_mode);
1265 			if (!ab)
1266 				return;
1267 		}
1268 		break; }
1269 	case AUDIT_MQ_OPEN: {
1270 		audit_log_format(ab,
1271 			"oflag=0x%x mode=%#o mq_flags=0x%lx mq_maxmsg=%ld "
1272 			"mq_msgsize=%ld mq_curmsgs=%ld",
1273 			context->mq_open.oflag, context->mq_open.mode,
1274 			context->mq_open.attr.mq_flags,
1275 			context->mq_open.attr.mq_maxmsg,
1276 			context->mq_open.attr.mq_msgsize,
1277 			context->mq_open.attr.mq_curmsgs);
1278 		break; }
1279 	case AUDIT_MQ_SENDRECV: {
1280 		audit_log_format(ab,
1281 			"mqdes=%d msg_len=%zd msg_prio=%u "
1282 			"abs_timeout_sec=%ld abs_timeout_nsec=%ld",
1283 			context->mq_sendrecv.mqdes,
1284 			context->mq_sendrecv.msg_len,
1285 			context->mq_sendrecv.msg_prio,
1286 			context->mq_sendrecv.abs_timeout.tv_sec,
1287 			context->mq_sendrecv.abs_timeout.tv_nsec);
1288 		break; }
1289 	case AUDIT_MQ_NOTIFY: {
1290 		audit_log_format(ab, "mqdes=%d sigev_signo=%d",
1291 				context->mq_notify.mqdes,
1292 				context->mq_notify.sigev_signo);
1293 		break; }
1294 	case AUDIT_MQ_GETSETATTR: {
1295 		struct mq_attr *attr = &context->mq_getsetattr.mqstat;
1296 		audit_log_format(ab,
1297 			"mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
1298 			"mq_curmsgs=%ld ",
1299 			context->mq_getsetattr.mqdes,
1300 			attr->mq_flags, attr->mq_maxmsg,
1301 			attr->mq_msgsize, attr->mq_curmsgs);
1302 		break; }
1303 	case AUDIT_CAPSET: {
1304 		audit_log_format(ab, "pid=%d", context->capset.pid);
1305 		audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable);
1306 		audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted);
1307 		audit_log_cap(ab, "cap_pe", &context->capset.cap.effective);
1308 		break; }
1309 	}
1310 	audit_log_end(ab);
1311 }
1312 
1313 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
1314 {
1315 	const struct cred *cred;
1316 	int i, call_panic = 0;
1317 	struct audit_buffer *ab;
1318 	struct audit_aux_data *aux;
1319 	const char *tty;
1320 
1321 	/* tsk == current */
1322 	context->pid = tsk->pid;
1323 	if (!context->ppid)
1324 		context->ppid = sys_getppid();
1325 	cred = current_cred();
1326 	context->uid   = cred->uid;
1327 	context->gid   = cred->gid;
1328 	context->euid  = cred->euid;
1329 	context->suid  = cred->suid;
1330 	context->fsuid = cred->fsuid;
1331 	context->egid  = cred->egid;
1332 	context->sgid  = cred->sgid;
1333 	context->fsgid = cred->fsgid;
1334 	context->personality = tsk->personality;
1335 
1336 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
1337 	if (!ab)
1338 		return;		/* audit_panic has been called */
1339 	audit_log_format(ab, "arch=%x syscall=%d",
1340 			 context->arch, context->major);
1341 	if (context->personality != PER_LINUX)
1342 		audit_log_format(ab, " per=%lx", context->personality);
1343 	if (context->return_valid)
1344 		audit_log_format(ab, " success=%s exit=%ld",
1345 				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
1346 				 context->return_code);
1347 
1348 	spin_lock_irq(&tsk->sighand->siglock);
1349 	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
1350 		tty = tsk->signal->tty->name;
1351 	else
1352 		tty = "(none)";
1353 	spin_unlock_irq(&tsk->sighand->siglock);
1354 
1355 	audit_log_format(ab,
1356 		  " a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
1357 		  " ppid=%d pid=%d auid=%u uid=%u gid=%u"
1358 		  " euid=%u suid=%u fsuid=%u"
1359 		  " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
1360 		  context->argv[0],
1361 		  context->argv[1],
1362 		  context->argv[2],
1363 		  context->argv[3],
1364 		  context->name_count,
1365 		  context->ppid,
1366 		  context->pid,
1367 		  tsk->loginuid,
1368 		  context->uid,
1369 		  context->gid,
1370 		  context->euid, context->suid, context->fsuid,
1371 		  context->egid, context->sgid, context->fsgid, tty,
1372 		  tsk->sessionid);
1373 
1374 
1375 	audit_log_task_info(ab, tsk);
1376 	audit_log_key(ab, context->filterkey);
1377 	audit_log_end(ab);
1378 
1379 	for (aux = context->aux; aux; aux = aux->next) {
1380 
1381 		ab = audit_log_start(context, GFP_KERNEL, aux->type);
1382 		if (!ab)
1383 			continue; /* audit_panic has been called */
1384 
1385 		switch (aux->type) {
1386 
1387 		case AUDIT_EXECVE: {
1388 			struct audit_aux_data_execve *axi = (void *)aux;
1389 			audit_log_execve_info(context, &ab, axi);
1390 			break; }
1391 
1392 		case AUDIT_BPRM_FCAPS: {
1393 			struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
1394 			audit_log_format(ab, "fver=%x", axs->fcap_ver);
1395 			audit_log_cap(ab, "fp", &axs->fcap.permitted);
1396 			audit_log_cap(ab, "fi", &axs->fcap.inheritable);
1397 			audit_log_format(ab, " fe=%d", axs->fcap.fE);
1398 			audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted);
1399 			audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable);
1400 			audit_log_cap(ab, "old_pe", &axs->old_pcap.effective);
1401 			audit_log_cap(ab, "new_pp", &axs->new_pcap.permitted);
1402 			audit_log_cap(ab, "new_pi", &axs->new_pcap.inheritable);
1403 			audit_log_cap(ab, "new_pe", &axs->new_pcap.effective);
1404 			break; }
1405 
1406 		}
1407 		audit_log_end(ab);
1408 	}
1409 
1410 	if (context->type)
1411 		show_special(context, &call_panic);
1412 
1413 	if (context->fds[0] >= 0) {
1414 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR);
1415 		if (ab) {
1416 			audit_log_format(ab, "fd0=%d fd1=%d",
1417 					context->fds[0], context->fds[1]);
1418 			audit_log_end(ab);
1419 		}
1420 	}
1421 
1422 	if (context->sockaddr_len) {
1423 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
1424 		if (ab) {
1425 			audit_log_format(ab, "saddr=");
1426 			audit_log_n_hex(ab, (void *)context->sockaddr,
1427 					context->sockaddr_len);
1428 			audit_log_end(ab);
1429 		}
1430 	}
1431 
1432 	for (aux = context->aux_pids; aux; aux = aux->next) {
1433 		struct audit_aux_data_pids *axs = (void *)aux;
1434 
1435 		for (i = 0; i < axs->pid_count; i++)
1436 			if (audit_log_pid_context(context, axs->target_pid[i],
1437 						  axs->target_auid[i],
1438 						  axs->target_uid[i],
1439 						  axs->target_sessionid[i],
1440 						  axs->target_sid[i],
1441 						  axs->target_comm[i]))
1442 				call_panic = 1;
1443 	}
1444 
1445 	if (context->target_pid &&
1446 	    audit_log_pid_context(context, context->target_pid,
1447 				  context->target_auid, context->target_uid,
1448 				  context->target_sessionid,
1449 				  context->target_sid, context->target_comm))
1450 			call_panic = 1;
1451 
1452 	if (context->pwd.dentry && context->pwd.mnt) {
1453 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
1454 		if (ab) {
1455 			audit_log_d_path(ab, "cwd=", &context->pwd);
1456 			audit_log_end(ab);
1457 		}
1458 	}
1459 	for (i = 0; i < context->name_count; i++) {
1460 		struct audit_names *n = &context->names[i];
1461 
1462 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
1463 		if (!ab)
1464 			continue; /* audit_panic has been called */
1465 
1466 		audit_log_format(ab, "item=%d", i);
1467 
1468 		if (n->name) {
1469 			switch(n->name_len) {
1470 			case AUDIT_NAME_FULL:
1471 				/* log the full path */
1472 				audit_log_format(ab, " name=");
1473 				audit_log_untrustedstring(ab, n->name);
1474 				break;
1475 			case 0:
1476 				/* name was specified as a relative path and the
1477 				 * directory component is the cwd */
1478 				audit_log_d_path(ab, "name=", &context->pwd);
1479 				break;
1480 			default:
1481 				/* log the name's directory component */
1482 				audit_log_format(ab, " name=");
1483 				audit_log_n_untrustedstring(ab, n->name,
1484 							    n->name_len);
1485 			}
1486 		} else
1487 			audit_log_format(ab, " name=(null)");
1488 
1489 		if (n->ino != (unsigned long)-1) {
1490 			audit_log_format(ab, " inode=%lu"
1491 					 " dev=%02x:%02x mode=%#o"
1492 					 " ouid=%u ogid=%u rdev=%02x:%02x",
1493 					 n->ino,
1494 					 MAJOR(n->dev),
1495 					 MINOR(n->dev),
1496 					 n->mode,
1497 					 n->uid,
1498 					 n->gid,
1499 					 MAJOR(n->rdev),
1500 					 MINOR(n->rdev));
1501 		}
1502 		if (n->osid != 0) {
1503 			char *ctx = NULL;
1504 			u32 len;
1505 			if (security_secid_to_secctx(
1506 				n->osid, &ctx, &len)) {
1507 				audit_log_format(ab, " osid=%u", n->osid);
1508 				call_panic = 2;
1509 			} else {
1510 				audit_log_format(ab, " obj=%s", ctx);
1511 				security_release_secctx(ctx, len);
1512 			}
1513 		}
1514 
1515 		audit_log_fcaps(ab, n);
1516 
1517 		audit_log_end(ab);
1518 	}
1519 
1520 	/* Send end of event record to help user space know we are finished */
1521 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
1522 	if (ab)
1523 		audit_log_end(ab);
1524 	if (call_panic)
1525 		audit_panic("error converting sid to string");
1526 }
1527 
1528 /**
1529  * audit_free - free a per-task audit context
1530  * @tsk: task whose audit context block to free
1531  *
1532  * Called from copy_process and do_exit
1533  */
1534 void audit_free(struct task_struct *tsk)
1535 {
1536 	struct audit_context *context;
1537 
1538 	context = audit_get_context(tsk, 0, 0);
1539 	if (likely(!context))
1540 		return;
1541 
1542 	/* Check for system calls that do not go through the exit
1543 	 * function (e.g., exit_group), then free context block.
1544 	 * We use GFP_ATOMIC here because we might be doing this
1545 	 * in the context of the idle thread */
1546 	/* that can happen only if we are called from do_exit() */
1547 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1548 		audit_log_exit(context, tsk);
1549 	if (!list_empty(&context->killed_trees))
1550 		audit_kill_trees(&context->killed_trees);
1551 
1552 	audit_free_context(context);
1553 }
1554 
1555 /**
1556  * audit_syscall_entry - fill in an audit record at syscall entry
1557  * @arch: architecture type
1558  * @major: major syscall type (function)
1559  * @a1: additional syscall register 1
1560  * @a2: additional syscall register 2
1561  * @a3: additional syscall register 3
1562  * @a4: additional syscall register 4
1563  *
1564  * Fill in audit context at syscall entry.  This only happens if the
1565  * audit context was created when the task was created and the state or
1566  * filters demand the audit context be built.  If the state from the
1567  * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1568  * then the record will be written at syscall exit time (otherwise, it
1569  * will only be written if another part of the kernel requests that it
1570  * be written).
1571  */
1572 void audit_syscall_entry(int arch, int major,
1573 			 unsigned long a1, unsigned long a2,
1574 			 unsigned long a3, unsigned long a4)
1575 {
1576 	struct task_struct *tsk = current;
1577 	struct audit_context *context = tsk->audit_context;
1578 	enum audit_state     state;
1579 
1580 	if (unlikely(!context))
1581 		return;
1582 
1583 	/*
1584 	 * This happens only on certain architectures that make system
1585 	 * calls in kernel_thread via the entry.S interface, instead of
1586 	 * with direct calls.  (If you are porting to a new
1587 	 * architecture, hitting this condition can indicate that you
1588 	 * got the _exit/_leave calls backward in entry.S.)
1589 	 *
1590 	 * i386     no
1591 	 * x86_64   no
1592 	 * ppc64    yes (see arch/powerpc/platforms/iseries/misc.S)
1593 	 *
1594 	 * This also happens with vm86 emulation in a non-nested manner
1595 	 * (entries without exits), so this case must be caught.
1596 	 */
1597 	if (context->in_syscall) {
1598 		struct audit_context *newctx;
1599 
1600 #if AUDIT_DEBUG
1601 		printk(KERN_ERR
1602 		       "audit(:%d) pid=%d in syscall=%d;"
1603 		       " entering syscall=%d\n",
1604 		       context->serial, tsk->pid, context->major, major);
1605 #endif
1606 		newctx = audit_alloc_context(context->state);
1607 		if (newctx) {
1608 			newctx->previous   = context;
1609 			context		   = newctx;
1610 			tsk->audit_context = newctx;
1611 		} else	{
1612 			/* If we can't alloc a new context, the best we
1613 			 * can do is to leak memory (any pending putname
1614 			 * will be lost).  The only other alternative is
1615 			 * to abandon auditing. */
1616 			audit_zero_context(context, context->state);
1617 		}
1618 	}
1619 	BUG_ON(context->in_syscall || context->name_count);
1620 
1621 	if (!audit_enabled)
1622 		return;
1623 
1624 	context->arch	    = arch;
1625 	context->major      = major;
1626 	context->argv[0]    = a1;
1627 	context->argv[1]    = a2;
1628 	context->argv[2]    = a3;
1629 	context->argv[3]    = a4;
1630 
1631 	state = context->state;
1632 	context->dummy = !audit_n_rules;
1633 	if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
1634 		context->prio = 0;
1635 		state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
1636 	}
1637 	if (likely(state == AUDIT_DISABLED))
1638 		return;
1639 
1640 	context->serial     = 0;
1641 	context->ctime      = CURRENT_TIME;
1642 	context->in_syscall = 1;
1643 	context->current_state  = state;
1644 	context->ppid       = 0;
1645 }
1646 
1647 void audit_finish_fork(struct task_struct *child)
1648 {
1649 	struct audit_context *ctx = current->audit_context;
1650 	struct audit_context *p = child->audit_context;
1651 	if (!p || !ctx)
1652 		return;
1653 	if (!ctx->in_syscall || ctx->current_state != AUDIT_RECORD_CONTEXT)
1654 		return;
1655 	p->arch = ctx->arch;
1656 	p->major = ctx->major;
1657 	memcpy(p->argv, ctx->argv, sizeof(ctx->argv));
1658 	p->ctime = ctx->ctime;
1659 	p->dummy = ctx->dummy;
1660 	p->in_syscall = ctx->in_syscall;
1661 	p->filterkey = kstrdup(ctx->filterkey, GFP_KERNEL);
1662 	p->ppid = current->pid;
1663 	p->prio = ctx->prio;
1664 	p->current_state = ctx->current_state;
1665 }
1666 
1667 /**
1668  * audit_syscall_exit - deallocate audit context after a system call
1669  * @valid: success/failure flag
1670  * @return_code: syscall return value
1671  *
1672  * Tear down after system call.  If the audit context has been marked as
1673  * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1674  * filtering, or because some other part of the kernel write an audit
1675  * message), then write out the syscall information.  In call cases,
1676  * free the names stored from getname().
1677  */
1678 void audit_syscall_exit(int valid, long return_code)
1679 {
1680 	struct task_struct *tsk = current;
1681 	struct audit_context *context;
1682 
1683 	context = audit_get_context(tsk, valid, return_code);
1684 
1685 	if (likely(!context))
1686 		return;
1687 
1688 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1689 		audit_log_exit(context, tsk);
1690 
1691 	context->in_syscall = 0;
1692 	context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
1693 
1694 	if (!list_empty(&context->killed_trees))
1695 		audit_kill_trees(&context->killed_trees);
1696 
1697 	if (context->previous) {
1698 		struct audit_context *new_context = context->previous;
1699 		context->previous  = NULL;
1700 		audit_free_context(context);
1701 		tsk->audit_context = new_context;
1702 	} else {
1703 		audit_free_names(context);
1704 		unroll_tree_refs(context, NULL, 0);
1705 		audit_free_aux(context);
1706 		context->aux = NULL;
1707 		context->aux_pids = NULL;
1708 		context->target_pid = 0;
1709 		context->target_sid = 0;
1710 		context->sockaddr_len = 0;
1711 		context->type = 0;
1712 		context->fds[0] = -1;
1713 		if (context->state != AUDIT_RECORD_CONTEXT) {
1714 			kfree(context->filterkey);
1715 			context->filterkey = NULL;
1716 		}
1717 		tsk->audit_context = context;
1718 	}
1719 }
1720 
1721 static inline void handle_one(const struct inode *inode)
1722 {
1723 #ifdef CONFIG_AUDIT_TREE
1724 	struct audit_context *context;
1725 	struct audit_tree_refs *p;
1726 	struct audit_chunk *chunk;
1727 	int count;
1728 	if (likely(list_empty(&inode->inotify_watches)))
1729 		return;
1730 	context = current->audit_context;
1731 	p = context->trees;
1732 	count = context->tree_count;
1733 	rcu_read_lock();
1734 	chunk = audit_tree_lookup(inode);
1735 	rcu_read_unlock();
1736 	if (!chunk)
1737 		return;
1738 	if (likely(put_tree_ref(context, chunk)))
1739 		return;
1740 	if (unlikely(!grow_tree_refs(context))) {
1741 		printk(KERN_WARNING "out of memory, audit has lost a tree reference\n");
1742 		audit_set_auditable(context);
1743 		audit_put_chunk(chunk);
1744 		unroll_tree_refs(context, p, count);
1745 		return;
1746 	}
1747 	put_tree_ref(context, chunk);
1748 #endif
1749 }
1750 
1751 static void handle_path(const struct dentry *dentry)
1752 {
1753 #ifdef CONFIG_AUDIT_TREE
1754 	struct audit_context *context;
1755 	struct audit_tree_refs *p;
1756 	const struct dentry *d, *parent;
1757 	struct audit_chunk *drop;
1758 	unsigned long seq;
1759 	int count;
1760 
1761 	context = current->audit_context;
1762 	p = context->trees;
1763 	count = context->tree_count;
1764 retry:
1765 	drop = NULL;
1766 	d = dentry;
1767 	rcu_read_lock();
1768 	seq = read_seqbegin(&rename_lock);
1769 	for(;;) {
1770 		struct inode *inode = d->d_inode;
1771 		if (inode && unlikely(!list_empty(&inode->inotify_watches))) {
1772 			struct audit_chunk *chunk;
1773 			chunk = audit_tree_lookup(inode);
1774 			if (chunk) {
1775 				if (unlikely(!put_tree_ref(context, chunk))) {
1776 					drop = chunk;
1777 					break;
1778 				}
1779 			}
1780 		}
1781 		parent = d->d_parent;
1782 		if (parent == d)
1783 			break;
1784 		d = parent;
1785 	}
1786 	if (unlikely(read_seqretry(&rename_lock, seq) || drop)) {  /* in this order */
1787 		rcu_read_unlock();
1788 		if (!drop) {
1789 			/* just a race with rename */
1790 			unroll_tree_refs(context, p, count);
1791 			goto retry;
1792 		}
1793 		audit_put_chunk(drop);
1794 		if (grow_tree_refs(context)) {
1795 			/* OK, got more space */
1796 			unroll_tree_refs(context, p, count);
1797 			goto retry;
1798 		}
1799 		/* too bad */
1800 		printk(KERN_WARNING
1801 			"out of memory, audit has lost a tree reference\n");
1802 		unroll_tree_refs(context, p, count);
1803 		audit_set_auditable(context);
1804 		return;
1805 	}
1806 	rcu_read_unlock();
1807 #endif
1808 }
1809 
1810 /**
1811  * audit_getname - add a name to the list
1812  * @name: name to add
1813  *
1814  * Add a name to the list of audit names for this context.
1815  * Called from fs/namei.c:getname().
1816  */
1817 void __audit_getname(const char *name)
1818 {
1819 	struct audit_context *context = current->audit_context;
1820 
1821 	if (IS_ERR(name) || !name)
1822 		return;
1823 
1824 	if (!context->in_syscall) {
1825 #if AUDIT_DEBUG == 2
1826 		printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)\n",
1827 		       __FILE__, __LINE__, context->serial, name);
1828 		dump_stack();
1829 #endif
1830 		return;
1831 	}
1832 	BUG_ON(context->name_count >= AUDIT_NAMES);
1833 	context->names[context->name_count].name = name;
1834 	context->names[context->name_count].name_len = AUDIT_NAME_FULL;
1835 	context->names[context->name_count].name_put = 1;
1836 	context->names[context->name_count].ino  = (unsigned long)-1;
1837 	context->names[context->name_count].osid = 0;
1838 	++context->name_count;
1839 	if (!context->pwd.dentry) {
1840 		read_lock(&current->fs->lock);
1841 		context->pwd = current->fs->pwd;
1842 		path_get(&current->fs->pwd);
1843 		read_unlock(&current->fs->lock);
1844 	}
1845 
1846 }
1847 
1848 /* audit_putname - intercept a putname request
1849  * @name: name to intercept and delay for putname
1850  *
1851  * If we have stored the name from getname in the audit context,
1852  * then we delay the putname until syscall exit.
1853  * Called from include/linux/fs.h:putname().
1854  */
1855 void audit_putname(const char *name)
1856 {
1857 	struct audit_context *context = current->audit_context;
1858 
1859 	BUG_ON(!context);
1860 	if (!context->in_syscall) {
1861 #if AUDIT_DEBUG == 2
1862 		printk(KERN_ERR "%s:%d(:%d): __putname(%p)\n",
1863 		       __FILE__, __LINE__, context->serial, name);
1864 		if (context->name_count) {
1865 			int i;
1866 			for (i = 0; i < context->name_count; i++)
1867 				printk(KERN_ERR "name[%d] = %p = %s\n", i,
1868 				       context->names[i].name,
1869 				       context->names[i].name ?: "(null)");
1870 		}
1871 #endif
1872 		__putname(name);
1873 	}
1874 #if AUDIT_DEBUG
1875 	else {
1876 		++context->put_count;
1877 		if (context->put_count > context->name_count) {
1878 			printk(KERN_ERR "%s:%d(:%d): major=%d"
1879 			       " in_syscall=%d putname(%p) name_count=%d"
1880 			       " put_count=%d\n",
1881 			       __FILE__, __LINE__,
1882 			       context->serial, context->major,
1883 			       context->in_syscall, name, context->name_count,
1884 			       context->put_count);
1885 			dump_stack();
1886 		}
1887 	}
1888 #endif
1889 }
1890 
1891 static int audit_inc_name_count(struct audit_context *context,
1892 				const struct inode *inode)
1893 {
1894 	if (context->name_count >= AUDIT_NAMES) {
1895 		if (inode)
1896 			printk(KERN_DEBUG "name_count maxed, losing inode data: "
1897 			       "dev=%02x:%02x, inode=%lu\n",
1898 			       MAJOR(inode->i_sb->s_dev),
1899 			       MINOR(inode->i_sb->s_dev),
1900 			       inode->i_ino);
1901 
1902 		else
1903 			printk(KERN_DEBUG "name_count maxed, losing inode data\n");
1904 		return 1;
1905 	}
1906 	context->name_count++;
1907 #if AUDIT_DEBUG
1908 	context->ino_count++;
1909 #endif
1910 	return 0;
1911 }
1912 
1913 
1914 static inline int audit_copy_fcaps(struct audit_names *name, const struct dentry *dentry)
1915 {
1916 	struct cpu_vfs_cap_data caps;
1917 	int rc;
1918 
1919 	memset(&name->fcap.permitted, 0, sizeof(kernel_cap_t));
1920 	memset(&name->fcap.inheritable, 0, sizeof(kernel_cap_t));
1921 	name->fcap.fE = 0;
1922 	name->fcap_ver = 0;
1923 
1924 	if (!dentry)
1925 		return 0;
1926 
1927 	rc = get_vfs_caps_from_disk(dentry, &caps);
1928 	if (rc)
1929 		return rc;
1930 
1931 	name->fcap.permitted = caps.permitted;
1932 	name->fcap.inheritable = caps.inheritable;
1933 	name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
1934 	name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
1935 
1936 	return 0;
1937 }
1938 
1939 
1940 /* Copy inode data into an audit_names. */
1941 static void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
1942 			     const struct inode *inode)
1943 {
1944 	name->ino   = inode->i_ino;
1945 	name->dev   = inode->i_sb->s_dev;
1946 	name->mode  = inode->i_mode;
1947 	name->uid   = inode->i_uid;
1948 	name->gid   = inode->i_gid;
1949 	name->rdev  = inode->i_rdev;
1950 	security_inode_getsecid(inode, &name->osid);
1951 	audit_copy_fcaps(name, dentry);
1952 }
1953 
1954 /**
1955  * audit_inode - store the inode and device from a lookup
1956  * @name: name being audited
1957  * @dentry: dentry being audited
1958  *
1959  * Called from fs/namei.c:path_lookup().
1960  */
1961 void __audit_inode(const char *name, const struct dentry *dentry)
1962 {
1963 	int idx;
1964 	struct audit_context *context = current->audit_context;
1965 	const struct inode *inode = dentry->d_inode;
1966 
1967 	if (!context->in_syscall)
1968 		return;
1969 	if (context->name_count
1970 	    && context->names[context->name_count-1].name
1971 	    && context->names[context->name_count-1].name == name)
1972 		idx = context->name_count - 1;
1973 	else if (context->name_count > 1
1974 		 && context->names[context->name_count-2].name
1975 		 && context->names[context->name_count-2].name == name)
1976 		idx = context->name_count - 2;
1977 	else {
1978 		/* FIXME: how much do we care about inodes that have no
1979 		 * associated name? */
1980 		if (audit_inc_name_count(context, inode))
1981 			return;
1982 		idx = context->name_count - 1;
1983 		context->names[idx].name = NULL;
1984 	}
1985 	handle_path(dentry);
1986 	audit_copy_inode(&context->names[idx], dentry, inode);
1987 }
1988 
1989 /**
1990  * audit_inode_child - collect inode info for created/removed objects
1991  * @dname: inode's dentry name
1992  * @dentry: dentry being audited
1993  * @parent: inode of dentry parent
1994  *
1995  * For syscalls that create or remove filesystem objects, audit_inode
1996  * can only collect information for the filesystem object's parent.
1997  * This call updates the audit context with the child's information.
1998  * Syscalls that create a new filesystem object must be hooked after
1999  * the object is created.  Syscalls that remove a filesystem object
2000  * must be hooked prior, in order to capture the target inode during
2001  * unsuccessful attempts.
2002  */
2003 void __audit_inode_child(const char *dname, const struct dentry *dentry,
2004 			 const struct inode *parent)
2005 {
2006 	int idx;
2007 	struct audit_context *context = current->audit_context;
2008 	const char *found_parent = NULL, *found_child = NULL;
2009 	const struct inode *inode = dentry->d_inode;
2010 	int dirlen = 0;
2011 
2012 	if (!context->in_syscall)
2013 		return;
2014 
2015 	if (inode)
2016 		handle_one(inode);
2017 	/* determine matching parent */
2018 	if (!dname)
2019 		goto add_names;
2020 
2021 	/* parent is more likely, look for it first */
2022 	for (idx = 0; idx < context->name_count; idx++) {
2023 		struct audit_names *n = &context->names[idx];
2024 
2025 		if (!n->name)
2026 			continue;
2027 
2028 		if (n->ino == parent->i_ino &&
2029 		    !audit_compare_dname_path(dname, n->name, &dirlen)) {
2030 			n->name_len = dirlen; /* update parent data in place */
2031 			found_parent = n->name;
2032 			goto add_names;
2033 		}
2034 	}
2035 
2036 	/* no matching parent, look for matching child */
2037 	for (idx = 0; idx < context->name_count; idx++) {
2038 		struct audit_names *n = &context->names[idx];
2039 
2040 		if (!n->name)
2041 			continue;
2042 
2043 		/* strcmp() is the more likely scenario */
2044 		if (!strcmp(dname, n->name) ||
2045 		     !audit_compare_dname_path(dname, n->name, &dirlen)) {
2046 			if (inode)
2047 				audit_copy_inode(n, NULL, inode);
2048 			else
2049 				n->ino = (unsigned long)-1;
2050 			found_child = n->name;
2051 			goto add_names;
2052 		}
2053 	}
2054 
2055 add_names:
2056 	if (!found_parent) {
2057 		if (audit_inc_name_count(context, parent))
2058 			return;
2059 		idx = context->name_count - 1;
2060 		context->names[idx].name = NULL;
2061 		audit_copy_inode(&context->names[idx], NULL, parent);
2062 	}
2063 
2064 	if (!found_child) {
2065 		if (audit_inc_name_count(context, inode))
2066 			return;
2067 		idx = context->name_count - 1;
2068 
2069 		/* Re-use the name belonging to the slot for a matching parent
2070 		 * directory. All names for this context are relinquished in
2071 		 * audit_free_names() */
2072 		if (found_parent) {
2073 			context->names[idx].name = found_parent;
2074 			context->names[idx].name_len = AUDIT_NAME_FULL;
2075 			/* don't call __putname() */
2076 			context->names[idx].name_put = 0;
2077 		} else {
2078 			context->names[idx].name = NULL;
2079 		}
2080 
2081 		if (inode)
2082 			audit_copy_inode(&context->names[idx], NULL, inode);
2083 		else
2084 			context->names[idx].ino = (unsigned long)-1;
2085 	}
2086 }
2087 EXPORT_SYMBOL_GPL(__audit_inode_child);
2088 
2089 /**
2090  * auditsc_get_stamp - get local copies of audit_context values
2091  * @ctx: audit_context for the task
2092  * @t: timespec to store time recorded in the audit_context
2093  * @serial: serial value that is recorded in the audit_context
2094  *
2095  * Also sets the context as auditable.
2096  */
2097 int auditsc_get_stamp(struct audit_context *ctx,
2098 		       struct timespec *t, unsigned int *serial)
2099 {
2100 	if (!ctx->in_syscall)
2101 		return 0;
2102 	if (!ctx->serial)
2103 		ctx->serial = audit_serial();
2104 	t->tv_sec  = ctx->ctime.tv_sec;
2105 	t->tv_nsec = ctx->ctime.tv_nsec;
2106 	*serial    = ctx->serial;
2107 	if (!ctx->prio) {
2108 		ctx->prio = 1;
2109 		ctx->current_state = AUDIT_RECORD_CONTEXT;
2110 	}
2111 	return 1;
2112 }
2113 
2114 /* global counter which is incremented every time something logs in */
2115 static atomic_t session_id = ATOMIC_INIT(0);
2116 
2117 /**
2118  * audit_set_loginuid - set a task's audit_context loginuid
2119  * @task: task whose audit context is being modified
2120  * @loginuid: loginuid value
2121  *
2122  * Returns 0.
2123  *
2124  * Called (set) from fs/proc/base.c::proc_loginuid_write().
2125  */
2126 int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
2127 {
2128 	unsigned int sessionid = atomic_inc_return(&session_id);
2129 	struct audit_context *context = task->audit_context;
2130 
2131 	if (context && context->in_syscall) {
2132 		struct audit_buffer *ab;
2133 
2134 		ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
2135 		if (ab) {
2136 			audit_log_format(ab, "login pid=%d uid=%u "
2137 				"old auid=%u new auid=%u"
2138 				" old ses=%u new ses=%u",
2139 				task->pid, task_uid(task),
2140 				task->loginuid, loginuid,
2141 				task->sessionid, sessionid);
2142 			audit_log_end(ab);
2143 		}
2144 	}
2145 	task->sessionid = sessionid;
2146 	task->loginuid = loginuid;
2147 	return 0;
2148 }
2149 
2150 /**
2151  * __audit_mq_open - record audit data for a POSIX MQ open
2152  * @oflag: open flag
2153  * @mode: mode bits
2154  * @attr: queue attributes
2155  *
2156  */
2157 void __audit_mq_open(int oflag, mode_t mode, struct mq_attr *attr)
2158 {
2159 	struct audit_context *context = current->audit_context;
2160 
2161 	if (attr)
2162 		memcpy(&context->mq_open.attr, attr, sizeof(struct mq_attr));
2163 	else
2164 		memset(&context->mq_open.attr, 0, sizeof(struct mq_attr));
2165 
2166 	context->mq_open.oflag = oflag;
2167 	context->mq_open.mode = mode;
2168 
2169 	context->type = AUDIT_MQ_OPEN;
2170 }
2171 
2172 /**
2173  * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive
2174  * @mqdes: MQ descriptor
2175  * @msg_len: Message length
2176  * @msg_prio: Message priority
2177  * @abs_timeout: Message timeout in absolute time
2178  *
2179  */
2180 void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
2181 			const struct timespec *abs_timeout)
2182 {
2183 	struct audit_context *context = current->audit_context;
2184 	struct timespec *p = &context->mq_sendrecv.abs_timeout;
2185 
2186 	if (abs_timeout)
2187 		memcpy(p, abs_timeout, sizeof(struct timespec));
2188 	else
2189 		memset(p, 0, sizeof(struct timespec));
2190 
2191 	context->mq_sendrecv.mqdes = mqdes;
2192 	context->mq_sendrecv.msg_len = msg_len;
2193 	context->mq_sendrecv.msg_prio = msg_prio;
2194 
2195 	context->type = AUDIT_MQ_SENDRECV;
2196 }
2197 
2198 /**
2199  * __audit_mq_notify - record audit data for a POSIX MQ notify
2200  * @mqdes: MQ descriptor
2201  * @notification: Notification event
2202  *
2203  */
2204 
2205 void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
2206 {
2207 	struct audit_context *context = current->audit_context;
2208 
2209 	if (notification)
2210 		context->mq_notify.sigev_signo = notification->sigev_signo;
2211 	else
2212 		context->mq_notify.sigev_signo = 0;
2213 
2214 	context->mq_notify.mqdes = mqdes;
2215 	context->type = AUDIT_MQ_NOTIFY;
2216 }
2217 
2218 /**
2219  * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
2220  * @mqdes: MQ descriptor
2221  * @mqstat: MQ flags
2222  *
2223  */
2224 void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
2225 {
2226 	struct audit_context *context = current->audit_context;
2227 	context->mq_getsetattr.mqdes = mqdes;
2228 	context->mq_getsetattr.mqstat = *mqstat;
2229 	context->type = AUDIT_MQ_GETSETATTR;
2230 }
2231 
2232 /**
2233  * audit_ipc_obj - record audit data for ipc object
2234  * @ipcp: ipc permissions
2235  *
2236  */
2237 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
2238 {
2239 	struct audit_context *context = current->audit_context;
2240 	context->ipc.uid = ipcp->uid;
2241 	context->ipc.gid = ipcp->gid;
2242 	context->ipc.mode = ipcp->mode;
2243 	context->ipc.has_perm = 0;
2244 	security_ipc_getsecid(ipcp, &context->ipc.osid);
2245 	context->type = AUDIT_IPC;
2246 }
2247 
2248 /**
2249  * audit_ipc_set_perm - record audit data for new ipc permissions
2250  * @qbytes: msgq bytes
2251  * @uid: msgq user id
2252  * @gid: msgq group id
2253  * @mode: msgq mode (permissions)
2254  *
2255  * Called only after audit_ipc_obj().
2256  */
2257 void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
2258 {
2259 	struct audit_context *context = current->audit_context;
2260 
2261 	context->ipc.qbytes = qbytes;
2262 	context->ipc.perm_uid = uid;
2263 	context->ipc.perm_gid = gid;
2264 	context->ipc.perm_mode = mode;
2265 	context->ipc.has_perm = 1;
2266 }
2267 
2268 int audit_bprm(struct linux_binprm *bprm)
2269 {
2270 	struct audit_aux_data_execve *ax;
2271 	struct audit_context *context = current->audit_context;
2272 
2273 	if (likely(!audit_enabled || !context || context->dummy))
2274 		return 0;
2275 
2276 	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2277 	if (!ax)
2278 		return -ENOMEM;
2279 
2280 	ax->argc = bprm->argc;
2281 	ax->envc = bprm->envc;
2282 	ax->mm = bprm->mm;
2283 	ax->d.type = AUDIT_EXECVE;
2284 	ax->d.next = context->aux;
2285 	context->aux = (void *)ax;
2286 	return 0;
2287 }
2288 
2289 
2290 /**
2291  * audit_socketcall - record audit data for sys_socketcall
2292  * @nargs: number of args
2293  * @args: args array
2294  *
2295  */
2296 void audit_socketcall(int nargs, unsigned long *args)
2297 {
2298 	struct audit_context *context = current->audit_context;
2299 
2300 	if (likely(!context || context->dummy))
2301 		return;
2302 
2303 	context->type = AUDIT_SOCKETCALL;
2304 	context->socketcall.nargs = nargs;
2305 	memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long));
2306 }
2307 
2308 /**
2309  * __audit_fd_pair - record audit data for pipe and socketpair
2310  * @fd1: the first file descriptor
2311  * @fd2: the second file descriptor
2312  *
2313  */
2314 void __audit_fd_pair(int fd1, int fd2)
2315 {
2316 	struct audit_context *context = current->audit_context;
2317 	context->fds[0] = fd1;
2318 	context->fds[1] = fd2;
2319 }
2320 
2321 /**
2322  * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
2323  * @len: data length in user space
2324  * @a: data address in kernel space
2325  *
2326  * Returns 0 for success or NULL context or < 0 on error.
2327  */
2328 int audit_sockaddr(int len, void *a)
2329 {
2330 	struct audit_context *context = current->audit_context;
2331 
2332 	if (likely(!context || context->dummy))
2333 		return 0;
2334 
2335 	if (!context->sockaddr) {
2336 		void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL);
2337 		if (!p)
2338 			return -ENOMEM;
2339 		context->sockaddr = p;
2340 	}
2341 
2342 	context->sockaddr_len = len;
2343 	memcpy(context->sockaddr, a, len);
2344 	return 0;
2345 }
2346 
2347 void __audit_ptrace(struct task_struct *t)
2348 {
2349 	struct audit_context *context = current->audit_context;
2350 
2351 	context->target_pid = t->pid;
2352 	context->target_auid = audit_get_loginuid(t);
2353 	context->target_uid = task_uid(t);
2354 	context->target_sessionid = audit_get_sessionid(t);
2355 	security_task_getsecid(t, &context->target_sid);
2356 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
2357 }
2358 
2359 /**
2360  * audit_signal_info - record signal info for shutting down audit subsystem
2361  * @sig: signal value
2362  * @t: task being signaled
2363  *
2364  * If the audit subsystem is being terminated, record the task (pid)
2365  * and uid that is doing that.
2366  */
2367 int __audit_signal_info(int sig, struct task_struct *t)
2368 {
2369 	struct audit_aux_data_pids *axp;
2370 	struct task_struct *tsk = current;
2371 	struct audit_context *ctx = tsk->audit_context;
2372 	uid_t uid = current_uid(), t_uid = task_uid(t);
2373 
2374 	if (audit_pid && t->tgid == audit_pid) {
2375 		if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) {
2376 			audit_sig_pid = tsk->pid;
2377 			if (tsk->loginuid != -1)
2378 				audit_sig_uid = tsk->loginuid;
2379 			else
2380 				audit_sig_uid = uid;
2381 			security_task_getsecid(tsk, &audit_sig_sid);
2382 		}
2383 		if (!audit_signals || audit_dummy_context())
2384 			return 0;
2385 	}
2386 
2387 	/* optimize the common case by putting first signal recipient directly
2388 	 * in audit_context */
2389 	if (!ctx->target_pid) {
2390 		ctx->target_pid = t->tgid;
2391 		ctx->target_auid = audit_get_loginuid(t);
2392 		ctx->target_uid = t_uid;
2393 		ctx->target_sessionid = audit_get_sessionid(t);
2394 		security_task_getsecid(t, &ctx->target_sid);
2395 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
2396 		return 0;
2397 	}
2398 
2399 	axp = (void *)ctx->aux_pids;
2400 	if (!axp || axp->pid_count == AUDIT_AUX_PIDS) {
2401 		axp = kzalloc(sizeof(*axp), GFP_ATOMIC);
2402 		if (!axp)
2403 			return -ENOMEM;
2404 
2405 		axp->d.type = AUDIT_OBJ_PID;
2406 		axp->d.next = ctx->aux_pids;
2407 		ctx->aux_pids = (void *)axp;
2408 	}
2409 	BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);
2410 
2411 	axp->target_pid[axp->pid_count] = t->tgid;
2412 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
2413 	axp->target_uid[axp->pid_count] = t_uid;
2414 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
2415 	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
2416 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
2417 	axp->pid_count++;
2418 
2419 	return 0;
2420 }
2421 
2422 /**
2423  * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps
2424  * @bprm: pointer to the bprm being processed
2425  * @new: the proposed new credentials
2426  * @old: the old credentials
2427  *
2428  * Simply check if the proc already has the caps given by the file and if not
2429  * store the priv escalation info for later auditing at the end of the syscall
2430  *
2431  * -Eric
2432  */
2433 int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
2434 			   const struct cred *new, const struct cred *old)
2435 {
2436 	struct audit_aux_data_bprm_fcaps *ax;
2437 	struct audit_context *context = current->audit_context;
2438 	struct cpu_vfs_cap_data vcaps;
2439 	struct dentry *dentry;
2440 
2441 	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2442 	if (!ax)
2443 		return -ENOMEM;
2444 
2445 	ax->d.type = AUDIT_BPRM_FCAPS;
2446 	ax->d.next = context->aux;
2447 	context->aux = (void *)ax;
2448 
2449 	dentry = dget(bprm->file->f_dentry);
2450 	get_vfs_caps_from_disk(dentry, &vcaps);
2451 	dput(dentry);
2452 
2453 	ax->fcap.permitted = vcaps.permitted;
2454 	ax->fcap.inheritable = vcaps.inheritable;
2455 	ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2456 	ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
2457 
2458 	ax->old_pcap.permitted   = old->cap_permitted;
2459 	ax->old_pcap.inheritable = old->cap_inheritable;
2460 	ax->old_pcap.effective   = old->cap_effective;
2461 
2462 	ax->new_pcap.permitted   = new->cap_permitted;
2463 	ax->new_pcap.inheritable = new->cap_inheritable;
2464 	ax->new_pcap.effective   = new->cap_effective;
2465 	return 0;
2466 }
2467 
2468 /**
2469  * __audit_log_capset - store information about the arguments to the capset syscall
2470  * @pid: target pid of the capset call
2471  * @new: the new credentials
2472  * @old: the old (current) credentials
2473  *
2474  * Record the aguments userspace sent to sys_capset for later printing by the
2475  * audit system if applicable
2476  */
2477 void __audit_log_capset(pid_t pid,
2478 		       const struct cred *new, const struct cred *old)
2479 {
2480 	struct audit_context *context = current->audit_context;
2481 	context->capset.pid = pid;
2482 	context->capset.cap.effective   = new->cap_effective;
2483 	context->capset.cap.inheritable = new->cap_effective;
2484 	context->capset.cap.permitted   = new->cap_permitted;
2485 	context->type = AUDIT_CAPSET;
2486 }
2487 
2488 /**
2489  * audit_core_dumps - record information about processes that end abnormally
2490  * @signr: signal value
2491  *
2492  * If a process ends with a core dump, something fishy is going on and we
2493  * should record the event for investigation.
2494  */
2495 void audit_core_dumps(long signr)
2496 {
2497 	struct audit_buffer *ab;
2498 	u32 sid;
2499 	uid_t auid = audit_get_loginuid(current), uid;
2500 	gid_t gid;
2501 	unsigned int sessionid = audit_get_sessionid(current);
2502 
2503 	if (!audit_enabled)
2504 		return;
2505 
2506 	if (signr == SIGQUIT)	/* don't care for those */
2507 		return;
2508 
2509 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
2510 	current_uid_gid(&uid, &gid);
2511 	audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
2512 			 auid, uid, gid, sessionid);
2513 	security_task_getsecid(current, &sid);
2514 	if (sid) {
2515 		char *ctx = NULL;
2516 		u32 len;
2517 
2518 		if (security_secid_to_secctx(sid, &ctx, &len))
2519 			audit_log_format(ab, " ssid=%u", sid);
2520 		else {
2521 			audit_log_format(ab, " subj=%s", ctx);
2522 			security_release_secctx(ctx, len);
2523 		}
2524 	}
2525 	audit_log_format(ab, " pid=%d comm=", current->pid);
2526 	audit_log_untrustedstring(ab, current->comm);
2527 	audit_log_format(ab, " sig=%ld", signr);
2528 	audit_log_end(ab);
2529 }
2530 
2531 struct list_head *audit_killed_trees(void)
2532 {
2533 	struct audit_context *ctx = current->audit_context;
2534 	if (likely(!ctx || !ctx->in_syscall))
2535 		return NULL;
2536 	return &ctx->killed_trees;
2537 }
2538