xref: /openbmc/linux/kernel/auditsc.c (revision 6dfcd296)
1 /* auditsc.c -- System-call auditing support
2  * Handles all system-call specific auditing features.
3  *
4  * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
5  * Copyright 2005 Hewlett-Packard Development Company, L.P.
6  * Copyright (C) 2005, 2006 IBM Corporation
7  * All Rights Reserved.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
22  *
23  * Written by Rickard E. (Rik) Faith <faith@redhat.com>
24  *
25  * Many of the ideas implemented here are from Stephen C. Tweedie,
26  * especially the idea of avoiding a copy by using getname.
27  *
28  * The method for actual interception of syscall entry and exit (not in
29  * this file -- see entry.S) is based on a GPL'd patch written by
30  * okir@suse.de and Copyright 2003 SuSE Linux AG.
31  *
32  * POSIX message queue support added by George Wilson <ltcgcw@us.ibm.com>,
33  * 2006.
34  *
35  * The support of additional filter rules compares (>, <, >=, <=) was
36  * added by Dustin Kirkland <dustin.kirkland@us.ibm.com>, 2005.
37  *
38  * Modified by Amy Griffis <amy.griffis@hp.com> to collect additional
39  * filesystem information.
40  *
41  * Subject and object context labeling support added by <danjones@us.ibm.com>
42  * and <dustin.kirkland@us.ibm.com> for LSPP certification compliance.
43  */
44 
45 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
46 
47 #include <linux/init.h>
48 #include <asm/types.h>
49 #include <linux/atomic.h>
50 #include <linux/fs.h>
51 #include <linux/namei.h>
52 #include <linux/mm.h>
53 #include <linux/export.h>
54 #include <linux/slab.h>
55 #include <linux/mount.h>
56 #include <linux/socket.h>
57 #include <linux/mqueue.h>
58 #include <linux/audit.h>
59 #include <linux/personality.h>
60 #include <linux/time.h>
61 #include <linux/netlink.h>
62 #include <linux/compiler.h>
63 #include <asm/unistd.h>
64 #include <linux/security.h>
65 #include <linux/list.h>
66 #include <linux/binfmts.h>
67 #include <linux/highmem.h>
68 #include <linux/syscalls.h>
69 #include <asm/syscall.h>
70 #include <linux/capability.h>
71 #include <linux/fs_struct.h>
72 #include <linux/compat.h>
73 #include <linux/ctype.h>
74 #include <linux/string.h>
75 #include <linux/uaccess.h>
76 #include <uapi/linux/limits.h>
77 
78 #include "audit.h"
79 
80 /* flags stating the success for a syscall */
81 #define AUDITSC_INVALID 0
82 #define AUDITSC_SUCCESS 1
83 #define AUDITSC_FAILURE 2
84 
85 /* no execve audit message should be longer than this (userspace limits),
86  * see the note near the top of audit_log_execve_info() about this value */
87 #define MAX_EXECVE_AUDIT_LEN 7500
88 
89 /* max length to print of cmdline/proctitle value during audit */
90 #define MAX_PROCTITLE_AUDIT_LEN 128
91 
92 /* number of audit rules */
93 int audit_n_rules;
94 
95 /* determines whether we collect data for signals sent */
96 int audit_signals;
97 
98 struct audit_aux_data {
99 	struct audit_aux_data	*next;
100 	int			type;
101 };
102 
103 #define AUDIT_AUX_IPCPERM	0
104 
105 /* Number of target pids per aux struct. */
106 #define AUDIT_AUX_PIDS	16
107 
108 struct audit_aux_data_pids {
109 	struct audit_aux_data	d;
110 	pid_t			target_pid[AUDIT_AUX_PIDS];
111 	kuid_t			target_auid[AUDIT_AUX_PIDS];
112 	kuid_t			target_uid[AUDIT_AUX_PIDS];
113 	unsigned int		target_sessionid[AUDIT_AUX_PIDS];
114 	u32			target_sid[AUDIT_AUX_PIDS];
115 	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
116 	int			pid_count;
117 };
118 
119 struct audit_aux_data_bprm_fcaps {
120 	struct audit_aux_data	d;
121 	struct audit_cap_data	fcap;
122 	unsigned int		fcap_ver;
123 	struct audit_cap_data	old_pcap;
124 	struct audit_cap_data	new_pcap;
125 };
126 
127 struct audit_tree_refs {
128 	struct audit_tree_refs *next;
129 	struct audit_chunk *c[31];
130 };
131 
132 static int audit_match_perm(struct audit_context *ctx, int mask)
133 {
134 	unsigned n;
135 	if (unlikely(!ctx))
136 		return 0;
137 	n = ctx->major;
138 
139 	switch (audit_classify_syscall(ctx->arch, n)) {
140 	case 0:	/* native */
141 		if ((mask & AUDIT_PERM_WRITE) &&
142 		     audit_match_class(AUDIT_CLASS_WRITE, n))
143 			return 1;
144 		if ((mask & AUDIT_PERM_READ) &&
145 		     audit_match_class(AUDIT_CLASS_READ, n))
146 			return 1;
147 		if ((mask & AUDIT_PERM_ATTR) &&
148 		     audit_match_class(AUDIT_CLASS_CHATTR, n))
149 			return 1;
150 		return 0;
151 	case 1: /* 32bit on biarch */
152 		if ((mask & AUDIT_PERM_WRITE) &&
153 		     audit_match_class(AUDIT_CLASS_WRITE_32, n))
154 			return 1;
155 		if ((mask & AUDIT_PERM_READ) &&
156 		     audit_match_class(AUDIT_CLASS_READ_32, n))
157 			return 1;
158 		if ((mask & AUDIT_PERM_ATTR) &&
159 		     audit_match_class(AUDIT_CLASS_CHATTR_32, n))
160 			return 1;
161 		return 0;
162 	case 2: /* open */
163 		return mask & ACC_MODE(ctx->argv[1]);
164 	case 3: /* openat */
165 		return mask & ACC_MODE(ctx->argv[2]);
166 	case 4: /* socketcall */
167 		return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND);
168 	case 5: /* execve */
169 		return mask & AUDIT_PERM_EXEC;
170 	default:
171 		return 0;
172 	}
173 }
174 
175 static int audit_match_filetype(struct audit_context *ctx, int val)
176 {
177 	struct audit_names *n;
178 	umode_t mode = (umode_t)val;
179 
180 	if (unlikely(!ctx))
181 		return 0;
182 
183 	list_for_each_entry(n, &ctx->names_list, list) {
184 		if ((n->ino != AUDIT_INO_UNSET) &&
185 		    ((n->mode & S_IFMT) == mode))
186 			return 1;
187 	}
188 
189 	return 0;
190 }
191 
192 /*
193  * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
194  * ->first_trees points to its beginning, ->trees - to the current end of data.
195  * ->tree_count is the number of free entries in array pointed to by ->trees.
196  * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
197  * "empty" becomes (p, p, 31) afterwards.  We don't shrink the list (and seriously,
198  * it's going to remain 1-element for almost any setup) until we free context itself.
199  * References in it _are_ dropped - at the same time we free/drop aux stuff.
200  */
201 
202 #ifdef CONFIG_AUDIT_TREE
203 static void audit_set_auditable(struct audit_context *ctx)
204 {
205 	if (!ctx->prio) {
206 		ctx->prio = 1;
207 		ctx->current_state = AUDIT_RECORD_CONTEXT;
208 	}
209 }
210 
211 static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
212 {
213 	struct audit_tree_refs *p = ctx->trees;
214 	int left = ctx->tree_count;
215 	if (likely(left)) {
216 		p->c[--left] = chunk;
217 		ctx->tree_count = left;
218 		return 1;
219 	}
220 	if (!p)
221 		return 0;
222 	p = p->next;
223 	if (p) {
224 		p->c[30] = chunk;
225 		ctx->trees = p;
226 		ctx->tree_count = 30;
227 		return 1;
228 	}
229 	return 0;
230 }
231 
232 static int grow_tree_refs(struct audit_context *ctx)
233 {
234 	struct audit_tree_refs *p = ctx->trees;
235 	ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
236 	if (!ctx->trees) {
237 		ctx->trees = p;
238 		return 0;
239 	}
240 	if (p)
241 		p->next = ctx->trees;
242 	else
243 		ctx->first_trees = ctx->trees;
244 	ctx->tree_count = 31;
245 	return 1;
246 }
247 #endif
248 
249 static void unroll_tree_refs(struct audit_context *ctx,
250 		      struct audit_tree_refs *p, int count)
251 {
252 #ifdef CONFIG_AUDIT_TREE
253 	struct audit_tree_refs *q;
254 	int n;
255 	if (!p) {
256 		/* we started with empty chain */
257 		p = ctx->first_trees;
258 		count = 31;
259 		/* if the very first allocation has failed, nothing to do */
260 		if (!p)
261 			return;
262 	}
263 	n = count;
264 	for (q = p; q != ctx->trees; q = q->next, n = 31) {
265 		while (n--) {
266 			audit_put_chunk(q->c[n]);
267 			q->c[n] = NULL;
268 		}
269 	}
270 	while (n-- > ctx->tree_count) {
271 		audit_put_chunk(q->c[n]);
272 		q->c[n] = NULL;
273 	}
274 	ctx->trees = p;
275 	ctx->tree_count = count;
276 #endif
277 }
278 
279 static void free_tree_refs(struct audit_context *ctx)
280 {
281 	struct audit_tree_refs *p, *q;
282 	for (p = ctx->first_trees; p; p = q) {
283 		q = p->next;
284 		kfree(p);
285 	}
286 }
287 
288 static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
289 {
290 #ifdef CONFIG_AUDIT_TREE
291 	struct audit_tree_refs *p;
292 	int n;
293 	if (!tree)
294 		return 0;
295 	/* full ones */
296 	for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
297 		for (n = 0; n < 31; n++)
298 			if (audit_tree_match(p->c[n], tree))
299 				return 1;
300 	}
301 	/* partial */
302 	if (p) {
303 		for (n = ctx->tree_count; n < 31; n++)
304 			if (audit_tree_match(p->c[n], tree))
305 				return 1;
306 	}
307 #endif
308 	return 0;
309 }
310 
311 static int audit_compare_uid(kuid_t uid,
312 			     struct audit_names *name,
313 			     struct audit_field *f,
314 			     struct audit_context *ctx)
315 {
316 	struct audit_names *n;
317 	int rc;
318 
319 	if (name) {
320 		rc = audit_uid_comparator(uid, f->op, name->uid);
321 		if (rc)
322 			return rc;
323 	}
324 
325 	if (ctx) {
326 		list_for_each_entry(n, &ctx->names_list, list) {
327 			rc = audit_uid_comparator(uid, f->op, n->uid);
328 			if (rc)
329 				return rc;
330 		}
331 	}
332 	return 0;
333 }
334 
335 static int audit_compare_gid(kgid_t gid,
336 			     struct audit_names *name,
337 			     struct audit_field *f,
338 			     struct audit_context *ctx)
339 {
340 	struct audit_names *n;
341 	int rc;
342 
343 	if (name) {
344 		rc = audit_gid_comparator(gid, f->op, name->gid);
345 		if (rc)
346 			return rc;
347 	}
348 
349 	if (ctx) {
350 		list_for_each_entry(n, &ctx->names_list, list) {
351 			rc = audit_gid_comparator(gid, f->op, n->gid);
352 			if (rc)
353 				return rc;
354 		}
355 	}
356 	return 0;
357 }
358 
359 static int audit_field_compare(struct task_struct *tsk,
360 			       const struct cred *cred,
361 			       struct audit_field *f,
362 			       struct audit_context *ctx,
363 			       struct audit_names *name)
364 {
365 	switch (f->val) {
366 	/* process to file object comparisons */
367 	case AUDIT_COMPARE_UID_TO_OBJ_UID:
368 		return audit_compare_uid(cred->uid, name, f, ctx);
369 	case AUDIT_COMPARE_GID_TO_OBJ_GID:
370 		return audit_compare_gid(cred->gid, name, f, ctx);
371 	case AUDIT_COMPARE_EUID_TO_OBJ_UID:
372 		return audit_compare_uid(cred->euid, name, f, ctx);
373 	case AUDIT_COMPARE_EGID_TO_OBJ_GID:
374 		return audit_compare_gid(cred->egid, name, f, ctx);
375 	case AUDIT_COMPARE_AUID_TO_OBJ_UID:
376 		return audit_compare_uid(tsk->loginuid, name, f, ctx);
377 	case AUDIT_COMPARE_SUID_TO_OBJ_UID:
378 		return audit_compare_uid(cred->suid, name, f, ctx);
379 	case AUDIT_COMPARE_SGID_TO_OBJ_GID:
380 		return audit_compare_gid(cred->sgid, name, f, ctx);
381 	case AUDIT_COMPARE_FSUID_TO_OBJ_UID:
382 		return audit_compare_uid(cred->fsuid, name, f, ctx);
383 	case AUDIT_COMPARE_FSGID_TO_OBJ_GID:
384 		return audit_compare_gid(cred->fsgid, name, f, ctx);
385 	/* uid comparisons */
386 	case AUDIT_COMPARE_UID_TO_AUID:
387 		return audit_uid_comparator(cred->uid, f->op, tsk->loginuid);
388 	case AUDIT_COMPARE_UID_TO_EUID:
389 		return audit_uid_comparator(cred->uid, f->op, cred->euid);
390 	case AUDIT_COMPARE_UID_TO_SUID:
391 		return audit_uid_comparator(cred->uid, f->op, cred->suid);
392 	case AUDIT_COMPARE_UID_TO_FSUID:
393 		return audit_uid_comparator(cred->uid, f->op, cred->fsuid);
394 	/* auid comparisons */
395 	case AUDIT_COMPARE_AUID_TO_EUID:
396 		return audit_uid_comparator(tsk->loginuid, f->op, cred->euid);
397 	case AUDIT_COMPARE_AUID_TO_SUID:
398 		return audit_uid_comparator(tsk->loginuid, f->op, cred->suid);
399 	case AUDIT_COMPARE_AUID_TO_FSUID:
400 		return audit_uid_comparator(tsk->loginuid, f->op, cred->fsuid);
401 	/* euid comparisons */
402 	case AUDIT_COMPARE_EUID_TO_SUID:
403 		return audit_uid_comparator(cred->euid, f->op, cred->suid);
404 	case AUDIT_COMPARE_EUID_TO_FSUID:
405 		return audit_uid_comparator(cred->euid, f->op, cred->fsuid);
406 	/* suid comparisons */
407 	case AUDIT_COMPARE_SUID_TO_FSUID:
408 		return audit_uid_comparator(cred->suid, f->op, cred->fsuid);
409 	/* gid comparisons */
410 	case AUDIT_COMPARE_GID_TO_EGID:
411 		return audit_gid_comparator(cred->gid, f->op, cred->egid);
412 	case AUDIT_COMPARE_GID_TO_SGID:
413 		return audit_gid_comparator(cred->gid, f->op, cred->sgid);
414 	case AUDIT_COMPARE_GID_TO_FSGID:
415 		return audit_gid_comparator(cred->gid, f->op, cred->fsgid);
416 	/* egid comparisons */
417 	case AUDIT_COMPARE_EGID_TO_SGID:
418 		return audit_gid_comparator(cred->egid, f->op, cred->sgid);
419 	case AUDIT_COMPARE_EGID_TO_FSGID:
420 		return audit_gid_comparator(cred->egid, f->op, cred->fsgid);
421 	/* sgid comparison */
422 	case AUDIT_COMPARE_SGID_TO_FSGID:
423 		return audit_gid_comparator(cred->sgid, f->op, cred->fsgid);
424 	default:
425 		WARN(1, "Missing AUDIT_COMPARE define.  Report as a bug\n");
426 		return 0;
427 	}
428 	return 0;
429 }
430 
431 /* Determine if any context name data matches a rule's watch data */
432 /* Compare a task_struct with an audit_rule.  Return 1 on match, 0
433  * otherwise.
434  *
435  * If task_creation is true, this is an explicit indication that we are
436  * filtering a task rule at task creation time.  This and tsk == current are
437  * the only situations where tsk->cred may be accessed without an rcu read lock.
438  */
439 static int audit_filter_rules(struct task_struct *tsk,
440 			      struct audit_krule *rule,
441 			      struct audit_context *ctx,
442 			      struct audit_names *name,
443 			      enum audit_state *state,
444 			      bool task_creation)
445 {
446 	const struct cred *cred;
447 	int i, need_sid = 1;
448 	u32 sid;
449 
450 	cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
451 
452 	for (i = 0; i < rule->field_count; i++) {
453 		struct audit_field *f = &rule->fields[i];
454 		struct audit_names *n;
455 		int result = 0;
456 		pid_t pid;
457 
458 		switch (f->type) {
459 		case AUDIT_PID:
460 			pid = task_tgid_nr(tsk);
461 			result = audit_comparator(pid, f->op, f->val);
462 			break;
463 		case AUDIT_PPID:
464 			if (ctx) {
465 				if (!ctx->ppid)
466 					ctx->ppid = task_ppid_nr(tsk);
467 				result = audit_comparator(ctx->ppid, f->op, f->val);
468 			}
469 			break;
470 		case AUDIT_EXE:
471 			result = audit_exe_compare(tsk, rule->exe);
472 			break;
473 		case AUDIT_UID:
474 			result = audit_uid_comparator(cred->uid, f->op, f->uid);
475 			break;
476 		case AUDIT_EUID:
477 			result = audit_uid_comparator(cred->euid, f->op, f->uid);
478 			break;
479 		case AUDIT_SUID:
480 			result = audit_uid_comparator(cred->suid, f->op, f->uid);
481 			break;
482 		case AUDIT_FSUID:
483 			result = audit_uid_comparator(cred->fsuid, f->op, f->uid);
484 			break;
485 		case AUDIT_GID:
486 			result = audit_gid_comparator(cred->gid, f->op, f->gid);
487 			if (f->op == Audit_equal) {
488 				if (!result)
489 					result = in_group_p(f->gid);
490 			} else if (f->op == Audit_not_equal) {
491 				if (result)
492 					result = !in_group_p(f->gid);
493 			}
494 			break;
495 		case AUDIT_EGID:
496 			result = audit_gid_comparator(cred->egid, f->op, f->gid);
497 			if (f->op == Audit_equal) {
498 				if (!result)
499 					result = in_egroup_p(f->gid);
500 			} else if (f->op == Audit_not_equal) {
501 				if (result)
502 					result = !in_egroup_p(f->gid);
503 			}
504 			break;
505 		case AUDIT_SGID:
506 			result = audit_gid_comparator(cred->sgid, f->op, f->gid);
507 			break;
508 		case AUDIT_FSGID:
509 			result = audit_gid_comparator(cred->fsgid, f->op, f->gid);
510 			break;
511 		case AUDIT_PERS:
512 			result = audit_comparator(tsk->personality, f->op, f->val);
513 			break;
514 		case AUDIT_ARCH:
515 			if (ctx)
516 				result = audit_comparator(ctx->arch, f->op, f->val);
517 			break;
518 
519 		case AUDIT_EXIT:
520 			if (ctx && ctx->return_valid)
521 				result = audit_comparator(ctx->return_code, f->op, f->val);
522 			break;
523 		case AUDIT_SUCCESS:
524 			if (ctx && ctx->return_valid) {
525 				if (f->val)
526 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
527 				else
528 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);
529 			}
530 			break;
531 		case AUDIT_DEVMAJOR:
532 			if (name) {
533 				if (audit_comparator(MAJOR(name->dev), f->op, f->val) ||
534 				    audit_comparator(MAJOR(name->rdev), f->op, f->val))
535 					++result;
536 			} else if (ctx) {
537 				list_for_each_entry(n, &ctx->names_list, list) {
538 					if (audit_comparator(MAJOR(n->dev), f->op, f->val) ||
539 					    audit_comparator(MAJOR(n->rdev), f->op, f->val)) {
540 						++result;
541 						break;
542 					}
543 				}
544 			}
545 			break;
546 		case AUDIT_DEVMINOR:
547 			if (name) {
548 				if (audit_comparator(MINOR(name->dev), f->op, f->val) ||
549 				    audit_comparator(MINOR(name->rdev), f->op, f->val))
550 					++result;
551 			} else if (ctx) {
552 				list_for_each_entry(n, &ctx->names_list, list) {
553 					if (audit_comparator(MINOR(n->dev), f->op, f->val) ||
554 					    audit_comparator(MINOR(n->rdev), f->op, f->val)) {
555 						++result;
556 						break;
557 					}
558 				}
559 			}
560 			break;
561 		case AUDIT_INODE:
562 			if (name)
563 				result = audit_comparator(name->ino, f->op, f->val);
564 			else if (ctx) {
565 				list_for_each_entry(n, &ctx->names_list, list) {
566 					if (audit_comparator(n->ino, f->op, f->val)) {
567 						++result;
568 						break;
569 					}
570 				}
571 			}
572 			break;
573 		case AUDIT_OBJ_UID:
574 			if (name) {
575 				result = audit_uid_comparator(name->uid, f->op, f->uid);
576 			} else if (ctx) {
577 				list_for_each_entry(n, &ctx->names_list, list) {
578 					if (audit_uid_comparator(n->uid, f->op, f->uid)) {
579 						++result;
580 						break;
581 					}
582 				}
583 			}
584 			break;
585 		case AUDIT_OBJ_GID:
586 			if (name) {
587 				result = audit_gid_comparator(name->gid, f->op, f->gid);
588 			} else if (ctx) {
589 				list_for_each_entry(n, &ctx->names_list, list) {
590 					if (audit_gid_comparator(n->gid, f->op, f->gid)) {
591 						++result;
592 						break;
593 					}
594 				}
595 			}
596 			break;
597 		case AUDIT_WATCH:
598 			if (name)
599 				result = audit_watch_compare(rule->watch, name->ino, name->dev);
600 			break;
601 		case AUDIT_DIR:
602 			if (ctx)
603 				result = match_tree_refs(ctx, rule->tree);
604 			break;
605 		case AUDIT_LOGINUID:
606 			result = audit_uid_comparator(tsk->loginuid, f->op, f->uid);
607 			break;
608 		case AUDIT_LOGINUID_SET:
609 			result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
610 			break;
611 		case AUDIT_SUBJ_USER:
612 		case AUDIT_SUBJ_ROLE:
613 		case AUDIT_SUBJ_TYPE:
614 		case AUDIT_SUBJ_SEN:
615 		case AUDIT_SUBJ_CLR:
616 			/* NOTE: this may return negative values indicating
617 			   a temporary error.  We simply treat this as a
618 			   match for now to avoid losing information that
619 			   may be wanted.   An error message will also be
620 			   logged upon error */
621 			if (f->lsm_rule) {
622 				if (need_sid) {
623 					security_task_getsecid(tsk, &sid);
624 					need_sid = 0;
625 				}
626 				result = security_audit_rule_match(sid, f->type,
627 				                                  f->op,
628 				                                  f->lsm_rule,
629 				                                  ctx);
630 			}
631 			break;
632 		case AUDIT_OBJ_USER:
633 		case AUDIT_OBJ_ROLE:
634 		case AUDIT_OBJ_TYPE:
635 		case AUDIT_OBJ_LEV_LOW:
636 		case AUDIT_OBJ_LEV_HIGH:
637 			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
638 			   also applies here */
639 			if (f->lsm_rule) {
640 				/* Find files that match */
641 				if (name) {
642 					result = security_audit_rule_match(
643 					           name->osid, f->type, f->op,
644 					           f->lsm_rule, ctx);
645 				} else if (ctx) {
646 					list_for_each_entry(n, &ctx->names_list, list) {
647 						if (security_audit_rule_match(n->osid, f->type,
648 									      f->op, f->lsm_rule,
649 									      ctx)) {
650 							++result;
651 							break;
652 						}
653 					}
654 				}
655 				/* Find ipc objects that match */
656 				if (!ctx || ctx->type != AUDIT_IPC)
657 					break;
658 				if (security_audit_rule_match(ctx->ipc.osid,
659 							      f->type, f->op,
660 							      f->lsm_rule, ctx))
661 					++result;
662 			}
663 			break;
664 		case AUDIT_ARG0:
665 		case AUDIT_ARG1:
666 		case AUDIT_ARG2:
667 		case AUDIT_ARG3:
668 			if (ctx)
669 				result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
670 			break;
671 		case AUDIT_FILTERKEY:
672 			/* ignore this field for filtering */
673 			result = 1;
674 			break;
675 		case AUDIT_PERM:
676 			result = audit_match_perm(ctx, f->val);
677 			break;
678 		case AUDIT_FILETYPE:
679 			result = audit_match_filetype(ctx, f->val);
680 			break;
681 		case AUDIT_FIELD_COMPARE:
682 			result = audit_field_compare(tsk, cred, f, ctx, name);
683 			break;
684 		}
685 		if (!result)
686 			return 0;
687 	}
688 
689 	if (ctx) {
690 		if (rule->prio <= ctx->prio)
691 			return 0;
692 		if (rule->filterkey) {
693 			kfree(ctx->filterkey);
694 			ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
695 		}
696 		ctx->prio = rule->prio;
697 	}
698 	switch (rule->action) {
699 	case AUDIT_NEVER:
700 		*state = AUDIT_DISABLED;
701 		break;
702 	case AUDIT_ALWAYS:
703 		*state = AUDIT_RECORD_CONTEXT;
704 		break;
705 	}
706 	return 1;
707 }
708 
709 /* At process creation time, we can determine if system-call auditing is
710  * completely disabled for this task.  Since we only have the task
711  * structure at this point, we can only check uid and gid.
712  */
713 static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
714 {
715 	struct audit_entry *e;
716 	enum audit_state   state;
717 
718 	rcu_read_lock();
719 	list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
720 		if (audit_filter_rules(tsk, &e->rule, NULL, NULL,
721 				       &state, true)) {
722 			if (state == AUDIT_RECORD_CONTEXT)
723 				*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
724 			rcu_read_unlock();
725 			return state;
726 		}
727 	}
728 	rcu_read_unlock();
729 	return AUDIT_BUILD_CONTEXT;
730 }
731 
732 static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
733 {
734 	int word, bit;
735 
736 	if (val > 0xffffffff)
737 		return false;
738 
739 	word = AUDIT_WORD(val);
740 	if (word >= AUDIT_BITMASK_SIZE)
741 		return false;
742 
743 	bit = AUDIT_BIT(val);
744 
745 	return rule->mask[word] & bit;
746 }
747 
748 /* At syscall entry and exit time, this filter is called if the
749  * audit_state is not low enough that auditing cannot take place, but is
750  * also not high enough that we already know we have to write an audit
751  * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
752  */
753 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
754 					     struct audit_context *ctx,
755 					     struct list_head *list)
756 {
757 	struct audit_entry *e;
758 	enum audit_state state;
759 
760 	if (audit_pid && tsk->tgid == audit_pid)
761 		return AUDIT_DISABLED;
762 
763 	rcu_read_lock();
764 	if (!list_empty(list)) {
765 		list_for_each_entry_rcu(e, list, list) {
766 			if (audit_in_mask(&e->rule, ctx->major) &&
767 			    audit_filter_rules(tsk, &e->rule, ctx, NULL,
768 					       &state, false)) {
769 				rcu_read_unlock();
770 				ctx->current_state = state;
771 				return state;
772 			}
773 		}
774 	}
775 	rcu_read_unlock();
776 	return AUDIT_BUILD_CONTEXT;
777 }
778 
779 /*
780  * Given an audit_name check the inode hash table to see if they match.
781  * Called holding the rcu read lock to protect the use of audit_inode_hash
782  */
783 static int audit_filter_inode_name(struct task_struct *tsk,
784 				   struct audit_names *n,
785 				   struct audit_context *ctx) {
786 	int h = audit_hash_ino((u32)n->ino);
787 	struct list_head *list = &audit_inode_hash[h];
788 	struct audit_entry *e;
789 	enum audit_state state;
790 
791 	if (list_empty(list))
792 		return 0;
793 
794 	list_for_each_entry_rcu(e, list, list) {
795 		if (audit_in_mask(&e->rule, ctx->major) &&
796 		    audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {
797 			ctx->current_state = state;
798 			return 1;
799 		}
800 	}
801 
802 	return 0;
803 }
804 
805 /* At syscall exit time, this filter is called if any audit_names have been
806  * collected during syscall processing.  We only check rules in sublists at hash
807  * buckets applicable to the inode numbers in audit_names.
808  * Regarding audit_state, same rules apply as for audit_filter_syscall().
809  */
810 void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
811 {
812 	struct audit_names *n;
813 
814 	if (audit_pid && tsk->tgid == audit_pid)
815 		return;
816 
817 	rcu_read_lock();
818 
819 	list_for_each_entry(n, &ctx->names_list, list) {
820 		if (audit_filter_inode_name(tsk, n, ctx))
821 			break;
822 	}
823 	rcu_read_unlock();
824 }
825 
826 /* Transfer the audit context pointer to the caller, clearing it in the tsk's struct */
827 static inline struct audit_context *audit_take_context(struct task_struct *tsk,
828 						      int return_valid,
829 						      long return_code)
830 {
831 	struct audit_context *context = tsk->audit_context;
832 
833 	if (!context)
834 		return NULL;
835 	context->return_valid = return_valid;
836 
837 	/*
838 	 * we need to fix up the return code in the audit logs if the actual
839 	 * return codes are later going to be fixed up by the arch specific
840 	 * signal handlers
841 	 *
842 	 * This is actually a test for:
843 	 * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) ||
844 	 * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK)
845 	 *
846 	 * but is faster than a bunch of ||
847 	 */
848 	if (unlikely(return_code <= -ERESTARTSYS) &&
849 	    (return_code >= -ERESTART_RESTARTBLOCK) &&
850 	    (return_code != -ENOIOCTLCMD))
851 		context->return_code = -EINTR;
852 	else
853 		context->return_code  = return_code;
854 
855 	if (context->in_syscall && !context->dummy) {
856 		audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
857 		audit_filter_inodes(tsk, context);
858 	}
859 
860 	tsk->audit_context = NULL;
861 	return context;
862 }
863 
864 static inline void audit_proctitle_free(struct audit_context *context)
865 {
866 	kfree(context->proctitle.value);
867 	context->proctitle.value = NULL;
868 	context->proctitle.len = 0;
869 }
870 
871 static inline void audit_free_names(struct audit_context *context)
872 {
873 	struct audit_names *n, *next;
874 
875 	list_for_each_entry_safe(n, next, &context->names_list, list) {
876 		list_del(&n->list);
877 		if (n->name)
878 			putname(n->name);
879 		if (n->should_free)
880 			kfree(n);
881 	}
882 	context->name_count = 0;
883 	path_put(&context->pwd);
884 	context->pwd.dentry = NULL;
885 	context->pwd.mnt = NULL;
886 }
887 
888 static inline void audit_free_aux(struct audit_context *context)
889 {
890 	struct audit_aux_data *aux;
891 
892 	while ((aux = context->aux)) {
893 		context->aux = aux->next;
894 		kfree(aux);
895 	}
896 	while ((aux = context->aux_pids)) {
897 		context->aux_pids = aux->next;
898 		kfree(aux);
899 	}
900 }
901 
902 static inline struct audit_context *audit_alloc_context(enum audit_state state)
903 {
904 	struct audit_context *context;
905 
906 	context = kzalloc(sizeof(*context), GFP_KERNEL);
907 	if (!context)
908 		return NULL;
909 	context->state = state;
910 	context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
911 	INIT_LIST_HEAD(&context->killed_trees);
912 	INIT_LIST_HEAD(&context->names_list);
913 	return context;
914 }
915 
916 /**
917  * audit_alloc - allocate an audit context block for a task
918  * @tsk: task
919  *
920  * Filter on the task information and allocate a per-task audit context
921  * if necessary.  Doing so turns on system call auditing for the
922  * specified task.  This is called from copy_process, so no lock is
923  * needed.
924  */
925 int audit_alloc(struct task_struct *tsk)
926 {
927 	struct audit_context *context;
928 	enum audit_state     state;
929 	char *key = NULL;
930 
931 	if (likely(!audit_ever_enabled))
932 		return 0; /* Return if not auditing. */
933 
934 	state = audit_filter_task(tsk, &key);
935 	if (state == AUDIT_DISABLED) {
936 		clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
937 		return 0;
938 	}
939 
940 	if (!(context = audit_alloc_context(state))) {
941 		kfree(key);
942 		audit_log_lost("out of memory in audit_alloc");
943 		return -ENOMEM;
944 	}
945 	context->filterkey = key;
946 
947 	tsk->audit_context  = context;
948 	set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
949 	return 0;
950 }
951 
952 static inline void audit_free_context(struct audit_context *context)
953 {
954 	audit_free_names(context);
955 	unroll_tree_refs(context, NULL, 0);
956 	free_tree_refs(context);
957 	audit_free_aux(context);
958 	kfree(context->filterkey);
959 	kfree(context->sockaddr);
960 	audit_proctitle_free(context);
961 	kfree(context);
962 }
963 
964 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
965 				 kuid_t auid, kuid_t uid, unsigned int sessionid,
966 				 u32 sid, char *comm)
967 {
968 	struct audit_buffer *ab;
969 	char *ctx = NULL;
970 	u32 len;
971 	int rc = 0;
972 
973 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
974 	if (!ab)
975 		return rc;
976 
977 	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
978 			 from_kuid(&init_user_ns, auid),
979 			 from_kuid(&init_user_ns, uid), sessionid);
980 	if (sid) {
981 		if (security_secid_to_secctx(sid, &ctx, &len)) {
982 			audit_log_format(ab, " obj=(none)");
983 			rc = 1;
984 		} else {
985 			audit_log_format(ab, " obj=%s", ctx);
986 			security_release_secctx(ctx, len);
987 		}
988 	}
989 	audit_log_format(ab, " ocomm=");
990 	audit_log_untrustedstring(ab, comm);
991 	audit_log_end(ab);
992 
993 	return rc;
994 }
995 
996 static void audit_log_execve_info(struct audit_context *context,
997 				  struct audit_buffer **ab)
998 {
999 	long len_max;
1000 	long len_rem;
1001 	long len_full;
1002 	long len_buf;
1003 	long len_abuf;
1004 	long len_tmp;
1005 	bool require_data;
1006 	bool encode;
1007 	unsigned int iter;
1008 	unsigned int arg;
1009 	char *buf_head;
1010 	char *buf;
1011 	const char __user *p = (const char __user *)current->mm->arg_start;
1012 
1013 	/* NOTE: this buffer needs to be large enough to hold all the non-arg
1014 	 *       data we put in the audit record for this argument (see the
1015 	 *       code below) ... at this point in time 96 is plenty */
1016 	char abuf[96];
1017 
1018 	/* NOTE: we set MAX_EXECVE_AUDIT_LEN to a rather arbitrary limit, the
1019 	 *       current value of 7500 is not as important as the fact that it
1020 	 *       is less than 8k, a setting of 7500 gives us plenty of wiggle
1021 	 *       room if we go over a little bit in the logging below */
1022 	WARN_ON_ONCE(MAX_EXECVE_AUDIT_LEN > 7500);
1023 	len_max = MAX_EXECVE_AUDIT_LEN;
1024 
1025 	/* scratch buffer to hold the userspace args */
1026 	buf_head = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL);
1027 	if (!buf_head) {
1028 		audit_panic("out of memory for argv string");
1029 		return;
1030 	}
1031 	buf = buf_head;
1032 
1033 	audit_log_format(*ab, "argc=%d", context->execve.argc);
1034 
1035 	len_rem = len_max;
1036 	len_buf = 0;
1037 	len_full = 0;
1038 	require_data = true;
1039 	encode = false;
1040 	iter = 0;
1041 	arg = 0;
1042 	do {
1043 		/* NOTE: we don't ever want to trust this value for anything
1044 		 *       serious, but the audit record format insists we
1045 		 *       provide an argument length for really long arguments,
1046 		 *       e.g. > MAX_EXECVE_AUDIT_LEN, so we have no choice but
1047 		 *       to use strncpy_from_user() to obtain this value for
1048 		 *       recording in the log, although we don't use it
1049 		 *       anywhere here to avoid a double-fetch problem */
1050 		if (len_full == 0)
1051 			len_full = strnlen_user(p, MAX_ARG_STRLEN) - 1;
1052 
1053 		/* read more data from userspace */
1054 		if (require_data) {
1055 			/* can we make more room in the buffer? */
1056 			if (buf != buf_head) {
1057 				memmove(buf_head, buf, len_buf);
1058 				buf = buf_head;
1059 			}
1060 
1061 			/* fetch as much as we can of the argument */
1062 			len_tmp = strncpy_from_user(&buf_head[len_buf], p,
1063 						    len_max - len_buf);
1064 			if (len_tmp == -EFAULT) {
1065 				/* unable to copy from userspace */
1066 				send_sig(SIGKILL, current, 0);
1067 				goto out;
1068 			} else if (len_tmp == (len_max - len_buf)) {
1069 				/* buffer is not large enough */
1070 				require_data = true;
1071 				/* NOTE: if we are going to span multiple
1072 				 *       buffers force the encoding so we stand
1073 				 *       a chance at a sane len_full value and
1074 				 *       consistent record encoding */
1075 				encode = true;
1076 				len_full = len_full * 2;
1077 				p += len_tmp;
1078 			} else {
1079 				require_data = false;
1080 				if (!encode)
1081 					encode = audit_string_contains_control(
1082 								buf, len_tmp);
1083 				/* try to use a trusted value for len_full */
1084 				if (len_full < len_max)
1085 					len_full = (encode ?
1086 						    len_tmp * 2 : len_tmp);
1087 				p += len_tmp + 1;
1088 			}
1089 			len_buf += len_tmp;
1090 			buf_head[len_buf] = '\0';
1091 
1092 			/* length of the buffer in the audit record? */
1093 			len_abuf = (encode ? len_buf * 2 : len_buf + 2);
1094 		}
1095 
1096 		/* write as much as we can to the audit log */
1097 		if (len_buf > 0) {
1098 			/* NOTE: some magic numbers here - basically if we
1099 			 *       can't fit a reasonable amount of data into the
1100 			 *       existing audit buffer, flush it and start with
1101 			 *       a new buffer */
1102 			if ((sizeof(abuf) + 8) > len_rem) {
1103 				len_rem = len_max;
1104 				audit_log_end(*ab);
1105 				*ab = audit_log_start(context,
1106 						      GFP_KERNEL, AUDIT_EXECVE);
1107 				if (!*ab)
1108 					goto out;
1109 			}
1110 
1111 			/* create the non-arg portion of the arg record */
1112 			len_tmp = 0;
1113 			if (require_data || (iter > 0) ||
1114 			    ((len_abuf + sizeof(abuf)) > len_rem)) {
1115 				if (iter == 0) {
1116 					len_tmp += snprintf(&abuf[len_tmp],
1117 							sizeof(abuf) - len_tmp,
1118 							" a%d_len=%lu",
1119 							arg, len_full);
1120 				}
1121 				len_tmp += snprintf(&abuf[len_tmp],
1122 						    sizeof(abuf) - len_tmp,
1123 						    " a%d[%d]=", arg, iter++);
1124 			} else
1125 				len_tmp += snprintf(&abuf[len_tmp],
1126 						    sizeof(abuf) - len_tmp,
1127 						    " a%d=", arg);
1128 			WARN_ON(len_tmp >= sizeof(abuf));
1129 			abuf[sizeof(abuf) - 1] = '\0';
1130 
1131 			/* log the arg in the audit record */
1132 			audit_log_format(*ab, "%s", abuf);
1133 			len_rem -= len_tmp;
1134 			len_tmp = len_buf;
1135 			if (encode) {
1136 				if (len_abuf > len_rem)
1137 					len_tmp = len_rem / 2; /* encoding */
1138 				audit_log_n_hex(*ab, buf, len_tmp);
1139 				len_rem -= len_tmp * 2;
1140 				len_abuf -= len_tmp * 2;
1141 			} else {
1142 				if (len_abuf > len_rem)
1143 					len_tmp = len_rem - 2; /* quotes */
1144 				audit_log_n_string(*ab, buf, len_tmp);
1145 				len_rem -= len_tmp + 2;
1146 				/* don't subtract the "2" because we still need
1147 				 * to add quotes to the remaining string */
1148 				len_abuf -= len_tmp;
1149 			}
1150 			len_buf -= len_tmp;
1151 			buf += len_tmp;
1152 		}
1153 
1154 		/* ready to move to the next argument? */
1155 		if ((len_buf == 0) && !require_data) {
1156 			arg++;
1157 			iter = 0;
1158 			len_full = 0;
1159 			require_data = true;
1160 			encode = false;
1161 		}
1162 	} while (arg < context->execve.argc);
1163 
1164 	/* NOTE: the caller handles the final audit_log_end() call */
1165 
1166 out:
1167 	kfree(buf_head);
1168 }
1169 
1170 static void show_special(struct audit_context *context, int *call_panic)
1171 {
1172 	struct audit_buffer *ab;
1173 	int i;
1174 
1175 	ab = audit_log_start(context, GFP_KERNEL, context->type);
1176 	if (!ab)
1177 		return;
1178 
1179 	switch (context->type) {
1180 	case AUDIT_SOCKETCALL: {
1181 		int nargs = context->socketcall.nargs;
1182 		audit_log_format(ab, "nargs=%d", nargs);
1183 		for (i = 0; i < nargs; i++)
1184 			audit_log_format(ab, " a%d=%lx", i,
1185 				context->socketcall.args[i]);
1186 		break; }
1187 	case AUDIT_IPC: {
1188 		u32 osid = context->ipc.osid;
1189 
1190 		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
1191 				 from_kuid(&init_user_ns, context->ipc.uid),
1192 				 from_kgid(&init_user_ns, context->ipc.gid),
1193 				 context->ipc.mode);
1194 		if (osid) {
1195 			char *ctx = NULL;
1196 			u32 len;
1197 			if (security_secid_to_secctx(osid, &ctx, &len)) {
1198 				audit_log_format(ab, " osid=%u", osid);
1199 				*call_panic = 1;
1200 			} else {
1201 				audit_log_format(ab, " obj=%s", ctx);
1202 				security_release_secctx(ctx, len);
1203 			}
1204 		}
1205 		if (context->ipc.has_perm) {
1206 			audit_log_end(ab);
1207 			ab = audit_log_start(context, GFP_KERNEL,
1208 					     AUDIT_IPC_SET_PERM);
1209 			if (unlikely(!ab))
1210 				return;
1211 			audit_log_format(ab,
1212 				"qbytes=%lx ouid=%u ogid=%u mode=%#ho",
1213 				context->ipc.qbytes,
1214 				context->ipc.perm_uid,
1215 				context->ipc.perm_gid,
1216 				context->ipc.perm_mode);
1217 		}
1218 		break; }
1219 	case AUDIT_MQ_OPEN: {
1220 		audit_log_format(ab,
1221 			"oflag=0x%x mode=%#ho mq_flags=0x%lx mq_maxmsg=%ld "
1222 			"mq_msgsize=%ld mq_curmsgs=%ld",
1223 			context->mq_open.oflag, context->mq_open.mode,
1224 			context->mq_open.attr.mq_flags,
1225 			context->mq_open.attr.mq_maxmsg,
1226 			context->mq_open.attr.mq_msgsize,
1227 			context->mq_open.attr.mq_curmsgs);
1228 		break; }
1229 	case AUDIT_MQ_SENDRECV: {
1230 		audit_log_format(ab,
1231 			"mqdes=%d msg_len=%zd msg_prio=%u "
1232 			"abs_timeout_sec=%ld abs_timeout_nsec=%ld",
1233 			context->mq_sendrecv.mqdes,
1234 			context->mq_sendrecv.msg_len,
1235 			context->mq_sendrecv.msg_prio,
1236 			context->mq_sendrecv.abs_timeout.tv_sec,
1237 			context->mq_sendrecv.abs_timeout.tv_nsec);
1238 		break; }
1239 	case AUDIT_MQ_NOTIFY: {
1240 		audit_log_format(ab, "mqdes=%d sigev_signo=%d",
1241 				context->mq_notify.mqdes,
1242 				context->mq_notify.sigev_signo);
1243 		break; }
1244 	case AUDIT_MQ_GETSETATTR: {
1245 		struct mq_attr *attr = &context->mq_getsetattr.mqstat;
1246 		audit_log_format(ab,
1247 			"mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
1248 			"mq_curmsgs=%ld ",
1249 			context->mq_getsetattr.mqdes,
1250 			attr->mq_flags, attr->mq_maxmsg,
1251 			attr->mq_msgsize, attr->mq_curmsgs);
1252 		break; }
1253 	case AUDIT_CAPSET: {
1254 		audit_log_format(ab, "pid=%d", context->capset.pid);
1255 		audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable);
1256 		audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted);
1257 		audit_log_cap(ab, "cap_pe", &context->capset.cap.effective);
1258 		break; }
1259 	case AUDIT_MMAP: {
1260 		audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd,
1261 				 context->mmap.flags);
1262 		break; }
1263 	case AUDIT_EXECVE: {
1264 		audit_log_execve_info(context, &ab);
1265 		break; }
1266 	}
1267 	audit_log_end(ab);
1268 }
1269 
1270 static inline int audit_proctitle_rtrim(char *proctitle, int len)
1271 {
1272 	char *end = proctitle + len - 1;
1273 	while (end > proctitle && !isprint(*end))
1274 		end--;
1275 
1276 	/* catch the case where proctitle is only 1 non-print character */
1277 	len = end - proctitle + 1;
1278 	len -= isprint(proctitle[len-1]) == 0;
1279 	return len;
1280 }
1281 
1282 static void audit_log_proctitle(struct task_struct *tsk,
1283 			 struct audit_context *context)
1284 {
1285 	int res;
1286 	char *buf;
1287 	char *msg = "(null)";
1288 	int len = strlen(msg);
1289 	struct audit_buffer *ab;
1290 
1291 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_PROCTITLE);
1292 	if (!ab)
1293 		return;	/* audit_panic or being filtered */
1294 
1295 	audit_log_format(ab, "proctitle=");
1296 
1297 	/* Not  cached */
1298 	if (!context->proctitle.value) {
1299 		buf = kmalloc(MAX_PROCTITLE_AUDIT_LEN, GFP_KERNEL);
1300 		if (!buf)
1301 			goto out;
1302 		/* Historically called this from procfs naming */
1303 		res = get_cmdline(tsk, buf, MAX_PROCTITLE_AUDIT_LEN);
1304 		if (res == 0) {
1305 			kfree(buf);
1306 			goto out;
1307 		}
1308 		res = audit_proctitle_rtrim(buf, res);
1309 		if (res == 0) {
1310 			kfree(buf);
1311 			goto out;
1312 		}
1313 		context->proctitle.value = buf;
1314 		context->proctitle.len = res;
1315 	}
1316 	msg = context->proctitle.value;
1317 	len = context->proctitle.len;
1318 out:
1319 	audit_log_n_untrustedstring(ab, msg, len);
1320 	audit_log_end(ab);
1321 }
1322 
1323 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
1324 {
1325 	int i, call_panic = 0;
1326 	struct audit_buffer *ab;
1327 	struct audit_aux_data *aux;
1328 	struct audit_names *n;
1329 
1330 	/* tsk == current */
1331 	context->personality = tsk->personality;
1332 
1333 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
1334 	if (!ab)
1335 		return;		/* audit_panic has been called */
1336 	audit_log_format(ab, "arch=%x syscall=%d",
1337 			 context->arch, context->major);
1338 	if (context->personality != PER_LINUX)
1339 		audit_log_format(ab, " per=%lx", context->personality);
1340 	if (context->return_valid)
1341 		audit_log_format(ab, " success=%s exit=%ld",
1342 				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
1343 				 context->return_code);
1344 
1345 	audit_log_format(ab,
1346 			 " a0=%lx a1=%lx a2=%lx a3=%lx items=%d",
1347 			 context->argv[0],
1348 			 context->argv[1],
1349 			 context->argv[2],
1350 			 context->argv[3],
1351 			 context->name_count);
1352 
1353 	audit_log_task_info(ab, tsk);
1354 	audit_log_key(ab, context->filterkey);
1355 	audit_log_end(ab);
1356 
1357 	for (aux = context->aux; aux; aux = aux->next) {
1358 
1359 		ab = audit_log_start(context, GFP_KERNEL, aux->type);
1360 		if (!ab)
1361 			continue; /* audit_panic has been called */
1362 
1363 		switch (aux->type) {
1364 
1365 		case AUDIT_BPRM_FCAPS: {
1366 			struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
1367 			audit_log_format(ab, "fver=%x", axs->fcap_ver);
1368 			audit_log_cap(ab, "fp", &axs->fcap.permitted);
1369 			audit_log_cap(ab, "fi", &axs->fcap.inheritable);
1370 			audit_log_format(ab, " fe=%d", axs->fcap.fE);
1371 			audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted);
1372 			audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable);
1373 			audit_log_cap(ab, "old_pe", &axs->old_pcap.effective);
1374 			audit_log_cap(ab, "new_pp", &axs->new_pcap.permitted);
1375 			audit_log_cap(ab, "new_pi", &axs->new_pcap.inheritable);
1376 			audit_log_cap(ab, "new_pe", &axs->new_pcap.effective);
1377 			break; }
1378 
1379 		}
1380 		audit_log_end(ab);
1381 	}
1382 
1383 	if (context->type)
1384 		show_special(context, &call_panic);
1385 
1386 	if (context->fds[0] >= 0) {
1387 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR);
1388 		if (ab) {
1389 			audit_log_format(ab, "fd0=%d fd1=%d",
1390 					context->fds[0], context->fds[1]);
1391 			audit_log_end(ab);
1392 		}
1393 	}
1394 
1395 	if (context->sockaddr_len) {
1396 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
1397 		if (ab) {
1398 			audit_log_format(ab, "saddr=");
1399 			audit_log_n_hex(ab, (void *)context->sockaddr,
1400 					context->sockaddr_len);
1401 			audit_log_end(ab);
1402 		}
1403 	}
1404 
1405 	for (aux = context->aux_pids; aux; aux = aux->next) {
1406 		struct audit_aux_data_pids *axs = (void *)aux;
1407 
1408 		for (i = 0; i < axs->pid_count; i++)
1409 			if (audit_log_pid_context(context, axs->target_pid[i],
1410 						  axs->target_auid[i],
1411 						  axs->target_uid[i],
1412 						  axs->target_sessionid[i],
1413 						  axs->target_sid[i],
1414 						  axs->target_comm[i]))
1415 				call_panic = 1;
1416 	}
1417 
1418 	if (context->target_pid &&
1419 	    audit_log_pid_context(context, context->target_pid,
1420 				  context->target_auid, context->target_uid,
1421 				  context->target_sessionid,
1422 				  context->target_sid, context->target_comm))
1423 			call_panic = 1;
1424 
1425 	if (context->pwd.dentry && context->pwd.mnt) {
1426 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
1427 		if (ab) {
1428 			audit_log_d_path(ab, "cwd=", &context->pwd);
1429 			audit_log_end(ab);
1430 		}
1431 	}
1432 
1433 	i = 0;
1434 	list_for_each_entry(n, &context->names_list, list) {
1435 		if (n->hidden)
1436 			continue;
1437 		audit_log_name(context, n, NULL, i++, &call_panic);
1438 	}
1439 
1440 	audit_log_proctitle(tsk, context);
1441 
1442 	/* Send end of event record to help user space know we are finished */
1443 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
1444 	if (ab)
1445 		audit_log_end(ab);
1446 	if (call_panic)
1447 		audit_panic("error converting sid to string");
1448 }
1449 
1450 /**
1451  * audit_free - free a per-task audit context
1452  * @tsk: task whose audit context block to free
1453  *
1454  * Called from copy_process and do_exit
1455  */
1456 void __audit_free(struct task_struct *tsk)
1457 {
1458 	struct audit_context *context;
1459 
1460 	context = audit_take_context(tsk, 0, 0);
1461 	if (!context)
1462 		return;
1463 
1464 	/* Check for system calls that do not go through the exit
1465 	 * function (e.g., exit_group), then free context block.
1466 	 * We use GFP_ATOMIC here because we might be doing this
1467 	 * in the context of the idle thread */
1468 	/* that can happen only if we are called from do_exit() */
1469 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1470 		audit_log_exit(context, tsk);
1471 	if (!list_empty(&context->killed_trees))
1472 		audit_kill_trees(&context->killed_trees);
1473 
1474 	audit_free_context(context);
1475 }
1476 
1477 /**
1478  * audit_syscall_entry - fill in an audit record at syscall entry
1479  * @major: major syscall type (function)
1480  * @a1: additional syscall register 1
1481  * @a2: additional syscall register 2
1482  * @a3: additional syscall register 3
1483  * @a4: additional syscall register 4
1484  *
1485  * Fill in audit context at syscall entry.  This only happens if the
1486  * audit context was created when the task was created and the state or
1487  * filters demand the audit context be built.  If the state from the
1488  * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1489  * then the record will be written at syscall exit time (otherwise, it
1490  * will only be written if another part of the kernel requests that it
1491  * be written).
1492  */
1493 void __audit_syscall_entry(int major, unsigned long a1, unsigned long a2,
1494 			   unsigned long a3, unsigned long a4)
1495 {
1496 	struct task_struct *tsk = current;
1497 	struct audit_context *context = tsk->audit_context;
1498 	enum audit_state     state;
1499 
1500 	if (!context)
1501 		return;
1502 
1503 	BUG_ON(context->in_syscall || context->name_count);
1504 
1505 	if (!audit_enabled)
1506 		return;
1507 
1508 	context->arch	    = syscall_get_arch();
1509 	context->major      = major;
1510 	context->argv[0]    = a1;
1511 	context->argv[1]    = a2;
1512 	context->argv[2]    = a3;
1513 	context->argv[3]    = a4;
1514 
1515 	state = context->state;
1516 	context->dummy = !audit_n_rules;
1517 	if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
1518 		context->prio = 0;
1519 		state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
1520 	}
1521 	if (state == AUDIT_DISABLED)
1522 		return;
1523 
1524 	context->serial     = 0;
1525 	context->ctime      = CURRENT_TIME;
1526 	context->in_syscall = 1;
1527 	context->current_state  = state;
1528 	context->ppid       = 0;
1529 }
1530 
1531 /**
1532  * audit_syscall_exit - deallocate audit context after a system call
1533  * @success: success value of the syscall
1534  * @return_code: return value of the syscall
1535  *
1536  * Tear down after system call.  If the audit context has been marked as
1537  * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1538  * filtering, or because some other part of the kernel wrote an audit
1539  * message), then write out the syscall information.  In call cases,
1540  * free the names stored from getname().
1541  */
1542 void __audit_syscall_exit(int success, long return_code)
1543 {
1544 	struct task_struct *tsk = current;
1545 	struct audit_context *context;
1546 
1547 	if (success)
1548 		success = AUDITSC_SUCCESS;
1549 	else
1550 		success = AUDITSC_FAILURE;
1551 
1552 	context = audit_take_context(tsk, success, return_code);
1553 	if (!context)
1554 		return;
1555 
1556 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1557 		audit_log_exit(context, tsk);
1558 
1559 	context->in_syscall = 0;
1560 	context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
1561 
1562 	if (!list_empty(&context->killed_trees))
1563 		audit_kill_trees(&context->killed_trees);
1564 
1565 	audit_free_names(context);
1566 	unroll_tree_refs(context, NULL, 0);
1567 	audit_free_aux(context);
1568 	context->aux = NULL;
1569 	context->aux_pids = NULL;
1570 	context->target_pid = 0;
1571 	context->target_sid = 0;
1572 	context->sockaddr_len = 0;
1573 	context->type = 0;
1574 	context->fds[0] = -1;
1575 	if (context->state != AUDIT_RECORD_CONTEXT) {
1576 		kfree(context->filterkey);
1577 		context->filterkey = NULL;
1578 	}
1579 	tsk->audit_context = context;
1580 }
1581 
1582 static inline void handle_one(const struct inode *inode)
1583 {
1584 #ifdef CONFIG_AUDIT_TREE
1585 	struct audit_context *context;
1586 	struct audit_tree_refs *p;
1587 	struct audit_chunk *chunk;
1588 	int count;
1589 	if (likely(hlist_empty(&inode->i_fsnotify_marks)))
1590 		return;
1591 	context = current->audit_context;
1592 	p = context->trees;
1593 	count = context->tree_count;
1594 	rcu_read_lock();
1595 	chunk = audit_tree_lookup(inode);
1596 	rcu_read_unlock();
1597 	if (!chunk)
1598 		return;
1599 	if (likely(put_tree_ref(context, chunk)))
1600 		return;
1601 	if (unlikely(!grow_tree_refs(context))) {
1602 		pr_warn("out of memory, audit has lost a tree reference\n");
1603 		audit_set_auditable(context);
1604 		audit_put_chunk(chunk);
1605 		unroll_tree_refs(context, p, count);
1606 		return;
1607 	}
1608 	put_tree_ref(context, chunk);
1609 #endif
1610 }
1611 
1612 static void handle_path(const struct dentry *dentry)
1613 {
1614 #ifdef CONFIG_AUDIT_TREE
1615 	struct audit_context *context;
1616 	struct audit_tree_refs *p;
1617 	const struct dentry *d, *parent;
1618 	struct audit_chunk *drop;
1619 	unsigned long seq;
1620 	int count;
1621 
1622 	context = current->audit_context;
1623 	p = context->trees;
1624 	count = context->tree_count;
1625 retry:
1626 	drop = NULL;
1627 	d = dentry;
1628 	rcu_read_lock();
1629 	seq = read_seqbegin(&rename_lock);
1630 	for(;;) {
1631 		struct inode *inode = d_backing_inode(d);
1632 		if (inode && unlikely(!hlist_empty(&inode->i_fsnotify_marks))) {
1633 			struct audit_chunk *chunk;
1634 			chunk = audit_tree_lookup(inode);
1635 			if (chunk) {
1636 				if (unlikely(!put_tree_ref(context, chunk))) {
1637 					drop = chunk;
1638 					break;
1639 				}
1640 			}
1641 		}
1642 		parent = d->d_parent;
1643 		if (parent == d)
1644 			break;
1645 		d = parent;
1646 	}
1647 	if (unlikely(read_seqretry(&rename_lock, seq) || drop)) {  /* in this order */
1648 		rcu_read_unlock();
1649 		if (!drop) {
1650 			/* just a race with rename */
1651 			unroll_tree_refs(context, p, count);
1652 			goto retry;
1653 		}
1654 		audit_put_chunk(drop);
1655 		if (grow_tree_refs(context)) {
1656 			/* OK, got more space */
1657 			unroll_tree_refs(context, p, count);
1658 			goto retry;
1659 		}
1660 		/* too bad */
1661 		pr_warn("out of memory, audit has lost a tree reference\n");
1662 		unroll_tree_refs(context, p, count);
1663 		audit_set_auditable(context);
1664 		return;
1665 	}
1666 	rcu_read_unlock();
1667 #endif
1668 }
1669 
1670 static struct audit_names *audit_alloc_name(struct audit_context *context,
1671 						unsigned char type)
1672 {
1673 	struct audit_names *aname;
1674 
1675 	if (context->name_count < AUDIT_NAMES) {
1676 		aname = &context->preallocated_names[context->name_count];
1677 		memset(aname, 0, sizeof(*aname));
1678 	} else {
1679 		aname = kzalloc(sizeof(*aname), GFP_NOFS);
1680 		if (!aname)
1681 			return NULL;
1682 		aname->should_free = true;
1683 	}
1684 
1685 	aname->ino = AUDIT_INO_UNSET;
1686 	aname->type = type;
1687 	list_add_tail(&aname->list, &context->names_list);
1688 
1689 	context->name_count++;
1690 	return aname;
1691 }
1692 
1693 /**
1694  * audit_reusename - fill out filename with info from existing entry
1695  * @uptr: userland ptr to pathname
1696  *
1697  * Search the audit_names list for the current audit context. If there is an
1698  * existing entry with a matching "uptr" then return the filename
1699  * associated with that audit_name. If not, return NULL.
1700  */
1701 struct filename *
1702 __audit_reusename(const __user char *uptr)
1703 {
1704 	struct audit_context *context = current->audit_context;
1705 	struct audit_names *n;
1706 
1707 	list_for_each_entry(n, &context->names_list, list) {
1708 		if (!n->name)
1709 			continue;
1710 		if (n->name->uptr == uptr) {
1711 			n->name->refcnt++;
1712 			return n->name;
1713 		}
1714 	}
1715 	return NULL;
1716 }
1717 
1718 /**
1719  * audit_getname - add a name to the list
1720  * @name: name to add
1721  *
1722  * Add a name to the list of audit names for this context.
1723  * Called from fs/namei.c:getname().
1724  */
1725 void __audit_getname(struct filename *name)
1726 {
1727 	struct audit_context *context = current->audit_context;
1728 	struct audit_names *n;
1729 
1730 	if (!context->in_syscall)
1731 		return;
1732 
1733 	n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1734 	if (!n)
1735 		return;
1736 
1737 	n->name = name;
1738 	n->name_len = AUDIT_NAME_FULL;
1739 	name->aname = n;
1740 	name->refcnt++;
1741 
1742 	if (!context->pwd.dentry)
1743 		get_fs_pwd(current->fs, &context->pwd);
1744 }
1745 
1746 /**
1747  * __audit_inode - store the inode and device from a lookup
1748  * @name: name being audited
1749  * @dentry: dentry being audited
1750  * @flags: attributes for this particular entry
1751  */
1752 void __audit_inode(struct filename *name, const struct dentry *dentry,
1753 		   unsigned int flags)
1754 {
1755 	struct audit_context *context = current->audit_context;
1756 	struct inode *inode = d_backing_inode(dentry);
1757 	struct audit_names *n;
1758 	bool parent = flags & AUDIT_INODE_PARENT;
1759 
1760 	if (!context->in_syscall)
1761 		return;
1762 
1763 	if (!name)
1764 		goto out_alloc;
1765 
1766 	/*
1767 	 * If we have a pointer to an audit_names entry already, then we can
1768 	 * just use it directly if the type is correct.
1769 	 */
1770 	n = name->aname;
1771 	if (n) {
1772 		if (parent) {
1773 			if (n->type == AUDIT_TYPE_PARENT ||
1774 			    n->type == AUDIT_TYPE_UNKNOWN)
1775 				goto out;
1776 		} else {
1777 			if (n->type != AUDIT_TYPE_PARENT)
1778 				goto out;
1779 		}
1780 	}
1781 
1782 	list_for_each_entry_reverse(n, &context->names_list, list) {
1783 		if (n->ino) {
1784 			/* valid inode number, use that for the comparison */
1785 			if (n->ino != inode->i_ino ||
1786 			    n->dev != inode->i_sb->s_dev)
1787 				continue;
1788 		} else if (n->name) {
1789 			/* inode number has not been set, check the name */
1790 			if (strcmp(n->name->name, name->name))
1791 				continue;
1792 		} else
1793 			/* no inode and no name (?!) ... this is odd ... */
1794 			continue;
1795 
1796 		/* match the correct record type */
1797 		if (parent) {
1798 			if (n->type == AUDIT_TYPE_PARENT ||
1799 			    n->type == AUDIT_TYPE_UNKNOWN)
1800 				goto out;
1801 		} else {
1802 			if (n->type != AUDIT_TYPE_PARENT)
1803 				goto out;
1804 		}
1805 	}
1806 
1807 out_alloc:
1808 	/* unable to find an entry with both a matching name and type */
1809 	n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1810 	if (!n)
1811 		return;
1812 	if (name) {
1813 		n->name = name;
1814 		name->refcnt++;
1815 	}
1816 
1817 out:
1818 	if (parent) {
1819 		n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL;
1820 		n->type = AUDIT_TYPE_PARENT;
1821 		if (flags & AUDIT_INODE_HIDDEN)
1822 			n->hidden = true;
1823 	} else {
1824 		n->name_len = AUDIT_NAME_FULL;
1825 		n->type = AUDIT_TYPE_NORMAL;
1826 	}
1827 	handle_path(dentry);
1828 	audit_copy_inode(n, dentry, inode);
1829 }
1830 
1831 void __audit_file(const struct file *file)
1832 {
1833 	__audit_inode(NULL, file->f_path.dentry, 0);
1834 }
1835 
1836 /**
1837  * __audit_inode_child - collect inode info for created/removed objects
1838  * @parent: inode of dentry parent
1839  * @dentry: dentry being audited
1840  * @type:   AUDIT_TYPE_* value that we're looking for
1841  *
1842  * For syscalls that create or remove filesystem objects, audit_inode
1843  * can only collect information for the filesystem object's parent.
1844  * This call updates the audit context with the child's information.
1845  * Syscalls that create a new filesystem object must be hooked after
1846  * the object is created.  Syscalls that remove a filesystem object
1847  * must be hooked prior, in order to capture the target inode during
1848  * unsuccessful attempts.
1849  */
1850 void __audit_inode_child(struct inode *parent,
1851 			 const struct dentry *dentry,
1852 			 const unsigned char type)
1853 {
1854 	struct audit_context *context = current->audit_context;
1855 	struct inode *inode = d_backing_inode(dentry);
1856 	const char *dname = dentry->d_name.name;
1857 	struct audit_names *n, *found_parent = NULL, *found_child = NULL;
1858 
1859 	if (!context->in_syscall)
1860 		return;
1861 
1862 	if (inode)
1863 		handle_one(inode);
1864 
1865 	/* look for a parent entry first */
1866 	list_for_each_entry(n, &context->names_list, list) {
1867 		if (!n->name ||
1868 		    (n->type != AUDIT_TYPE_PARENT &&
1869 		     n->type != AUDIT_TYPE_UNKNOWN))
1870 			continue;
1871 
1872 		if (n->ino == parent->i_ino && n->dev == parent->i_sb->s_dev &&
1873 		    !audit_compare_dname_path(dname,
1874 					      n->name->name, n->name_len)) {
1875 			if (n->type == AUDIT_TYPE_UNKNOWN)
1876 				n->type = AUDIT_TYPE_PARENT;
1877 			found_parent = n;
1878 			break;
1879 		}
1880 	}
1881 
1882 	/* is there a matching child entry? */
1883 	list_for_each_entry(n, &context->names_list, list) {
1884 		/* can only match entries that have a name */
1885 		if (!n->name ||
1886 		    (n->type != type && n->type != AUDIT_TYPE_UNKNOWN))
1887 			continue;
1888 
1889 		if (!strcmp(dname, n->name->name) ||
1890 		    !audit_compare_dname_path(dname, n->name->name,
1891 						found_parent ?
1892 						found_parent->name_len :
1893 						AUDIT_NAME_FULL)) {
1894 			if (n->type == AUDIT_TYPE_UNKNOWN)
1895 				n->type = type;
1896 			found_child = n;
1897 			break;
1898 		}
1899 	}
1900 
1901 	if (!found_parent) {
1902 		/* create a new, "anonymous" parent record */
1903 		n = audit_alloc_name(context, AUDIT_TYPE_PARENT);
1904 		if (!n)
1905 			return;
1906 		audit_copy_inode(n, NULL, parent);
1907 	}
1908 
1909 	if (!found_child) {
1910 		found_child = audit_alloc_name(context, type);
1911 		if (!found_child)
1912 			return;
1913 
1914 		/* Re-use the name belonging to the slot for a matching parent
1915 		 * directory. All names for this context are relinquished in
1916 		 * audit_free_names() */
1917 		if (found_parent) {
1918 			found_child->name = found_parent->name;
1919 			found_child->name_len = AUDIT_NAME_FULL;
1920 			found_child->name->refcnt++;
1921 		}
1922 	}
1923 
1924 	if (inode)
1925 		audit_copy_inode(found_child, dentry, inode);
1926 	else
1927 		found_child->ino = AUDIT_INO_UNSET;
1928 }
1929 EXPORT_SYMBOL_GPL(__audit_inode_child);
1930 
1931 /**
1932  * auditsc_get_stamp - get local copies of audit_context values
1933  * @ctx: audit_context for the task
1934  * @t: timespec to store time recorded in the audit_context
1935  * @serial: serial value that is recorded in the audit_context
1936  *
1937  * Also sets the context as auditable.
1938  */
1939 int auditsc_get_stamp(struct audit_context *ctx,
1940 		       struct timespec *t, unsigned int *serial)
1941 {
1942 	if (!ctx->in_syscall)
1943 		return 0;
1944 	if (!ctx->serial)
1945 		ctx->serial = audit_serial();
1946 	t->tv_sec  = ctx->ctime.tv_sec;
1947 	t->tv_nsec = ctx->ctime.tv_nsec;
1948 	*serial    = ctx->serial;
1949 	if (!ctx->prio) {
1950 		ctx->prio = 1;
1951 		ctx->current_state = AUDIT_RECORD_CONTEXT;
1952 	}
1953 	return 1;
1954 }
1955 
1956 /* global counter which is incremented every time something logs in */
1957 static atomic_t session_id = ATOMIC_INIT(0);
1958 
1959 static int audit_set_loginuid_perm(kuid_t loginuid)
1960 {
1961 	/* if we are unset, we don't need privs */
1962 	if (!audit_loginuid_set(current))
1963 		return 0;
1964 	/* if AUDIT_FEATURE_LOGINUID_IMMUTABLE means never ever allow a change*/
1965 	if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
1966 		return -EPERM;
1967 	/* it is set, you need permission */
1968 	if (!capable(CAP_AUDIT_CONTROL))
1969 		return -EPERM;
1970 	/* reject if this is not an unset and we don't allow that */
1971 	if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID) && uid_valid(loginuid))
1972 		return -EPERM;
1973 	return 0;
1974 }
1975 
1976 static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
1977 				   unsigned int oldsessionid, unsigned int sessionid,
1978 				   int rc)
1979 {
1980 	struct audit_buffer *ab;
1981 	uid_t uid, oldloginuid, loginuid;
1982 	struct tty_struct *tty;
1983 
1984 	if (!audit_enabled)
1985 		return;
1986 
1987 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
1988 	if (!ab)
1989 		return;
1990 
1991 	uid = from_kuid(&init_user_ns, task_uid(current));
1992 	oldloginuid = from_kuid(&init_user_ns, koldloginuid);
1993 	loginuid = from_kuid(&init_user_ns, kloginuid),
1994 	tty = audit_get_tty(current);
1995 
1996 	audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
1997 	audit_log_task_context(ab);
1998 	audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
1999 			 oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
2000 			 oldsessionid, sessionid, !rc);
2001 	audit_put_tty(tty);
2002 	audit_log_end(ab);
2003 }
2004 
2005 /**
2006  * audit_set_loginuid - set current task's audit_context loginuid
2007  * @loginuid: loginuid value
2008  *
2009  * Returns 0.
2010  *
2011  * Called (set) from fs/proc/base.c::proc_loginuid_write().
2012  */
2013 int audit_set_loginuid(kuid_t loginuid)
2014 {
2015 	struct task_struct *task = current;
2016 	unsigned int oldsessionid, sessionid = (unsigned int)-1;
2017 	kuid_t oldloginuid;
2018 	int rc;
2019 
2020 	oldloginuid = audit_get_loginuid(current);
2021 	oldsessionid = audit_get_sessionid(current);
2022 
2023 	rc = audit_set_loginuid_perm(loginuid);
2024 	if (rc)
2025 		goto out;
2026 
2027 	/* are we setting or clearing? */
2028 	if (uid_valid(loginuid))
2029 		sessionid = (unsigned int)atomic_inc_return(&session_id);
2030 
2031 	task->sessionid = sessionid;
2032 	task->loginuid = loginuid;
2033 out:
2034 	audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
2035 	return rc;
2036 }
2037 
2038 /**
2039  * __audit_mq_open - record audit data for a POSIX MQ open
2040  * @oflag: open flag
2041  * @mode: mode bits
2042  * @attr: queue attributes
2043  *
2044  */
2045 void __audit_mq_open(int oflag, umode_t mode, struct mq_attr *attr)
2046 {
2047 	struct audit_context *context = current->audit_context;
2048 
2049 	if (attr)
2050 		memcpy(&context->mq_open.attr, attr, sizeof(struct mq_attr));
2051 	else
2052 		memset(&context->mq_open.attr, 0, sizeof(struct mq_attr));
2053 
2054 	context->mq_open.oflag = oflag;
2055 	context->mq_open.mode = mode;
2056 
2057 	context->type = AUDIT_MQ_OPEN;
2058 }
2059 
2060 /**
2061  * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive
2062  * @mqdes: MQ descriptor
2063  * @msg_len: Message length
2064  * @msg_prio: Message priority
2065  * @abs_timeout: Message timeout in absolute time
2066  *
2067  */
2068 void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
2069 			const struct timespec *abs_timeout)
2070 {
2071 	struct audit_context *context = current->audit_context;
2072 	struct timespec *p = &context->mq_sendrecv.abs_timeout;
2073 
2074 	if (abs_timeout)
2075 		memcpy(p, abs_timeout, sizeof(struct timespec));
2076 	else
2077 		memset(p, 0, sizeof(struct timespec));
2078 
2079 	context->mq_sendrecv.mqdes = mqdes;
2080 	context->mq_sendrecv.msg_len = msg_len;
2081 	context->mq_sendrecv.msg_prio = msg_prio;
2082 
2083 	context->type = AUDIT_MQ_SENDRECV;
2084 }
2085 
2086 /**
2087  * __audit_mq_notify - record audit data for a POSIX MQ notify
2088  * @mqdes: MQ descriptor
2089  * @notification: Notification event
2090  *
2091  */
2092 
2093 void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
2094 {
2095 	struct audit_context *context = current->audit_context;
2096 
2097 	if (notification)
2098 		context->mq_notify.sigev_signo = notification->sigev_signo;
2099 	else
2100 		context->mq_notify.sigev_signo = 0;
2101 
2102 	context->mq_notify.mqdes = mqdes;
2103 	context->type = AUDIT_MQ_NOTIFY;
2104 }
2105 
2106 /**
2107  * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
2108  * @mqdes: MQ descriptor
2109  * @mqstat: MQ flags
2110  *
2111  */
2112 void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
2113 {
2114 	struct audit_context *context = current->audit_context;
2115 	context->mq_getsetattr.mqdes = mqdes;
2116 	context->mq_getsetattr.mqstat = *mqstat;
2117 	context->type = AUDIT_MQ_GETSETATTR;
2118 }
2119 
2120 /**
2121  * audit_ipc_obj - record audit data for ipc object
2122  * @ipcp: ipc permissions
2123  *
2124  */
2125 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
2126 {
2127 	struct audit_context *context = current->audit_context;
2128 	context->ipc.uid = ipcp->uid;
2129 	context->ipc.gid = ipcp->gid;
2130 	context->ipc.mode = ipcp->mode;
2131 	context->ipc.has_perm = 0;
2132 	security_ipc_getsecid(ipcp, &context->ipc.osid);
2133 	context->type = AUDIT_IPC;
2134 }
2135 
2136 /**
2137  * audit_ipc_set_perm - record audit data for new ipc permissions
2138  * @qbytes: msgq bytes
2139  * @uid: msgq user id
2140  * @gid: msgq group id
2141  * @mode: msgq mode (permissions)
2142  *
2143  * Called only after audit_ipc_obj().
2144  */
2145 void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode)
2146 {
2147 	struct audit_context *context = current->audit_context;
2148 
2149 	context->ipc.qbytes = qbytes;
2150 	context->ipc.perm_uid = uid;
2151 	context->ipc.perm_gid = gid;
2152 	context->ipc.perm_mode = mode;
2153 	context->ipc.has_perm = 1;
2154 }
2155 
2156 void __audit_bprm(struct linux_binprm *bprm)
2157 {
2158 	struct audit_context *context = current->audit_context;
2159 
2160 	context->type = AUDIT_EXECVE;
2161 	context->execve.argc = bprm->argc;
2162 }
2163 
2164 
2165 /**
2166  * audit_socketcall - record audit data for sys_socketcall
2167  * @nargs: number of args, which should not be more than AUDITSC_ARGS.
2168  * @args: args array
2169  *
2170  */
2171 int __audit_socketcall(int nargs, unsigned long *args)
2172 {
2173 	struct audit_context *context = current->audit_context;
2174 
2175 	if (nargs <= 0 || nargs > AUDITSC_ARGS || !args)
2176 		return -EINVAL;
2177 	context->type = AUDIT_SOCKETCALL;
2178 	context->socketcall.nargs = nargs;
2179 	memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long));
2180 	return 0;
2181 }
2182 
2183 /**
2184  * __audit_fd_pair - record audit data for pipe and socketpair
2185  * @fd1: the first file descriptor
2186  * @fd2: the second file descriptor
2187  *
2188  */
2189 void __audit_fd_pair(int fd1, int fd2)
2190 {
2191 	struct audit_context *context = current->audit_context;
2192 	context->fds[0] = fd1;
2193 	context->fds[1] = fd2;
2194 }
2195 
2196 /**
2197  * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
2198  * @len: data length in user space
2199  * @a: data address in kernel space
2200  *
2201  * Returns 0 for success or NULL context or < 0 on error.
2202  */
2203 int __audit_sockaddr(int len, void *a)
2204 {
2205 	struct audit_context *context = current->audit_context;
2206 
2207 	if (!context->sockaddr) {
2208 		void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL);
2209 		if (!p)
2210 			return -ENOMEM;
2211 		context->sockaddr = p;
2212 	}
2213 
2214 	context->sockaddr_len = len;
2215 	memcpy(context->sockaddr, a, len);
2216 	return 0;
2217 }
2218 
2219 void __audit_ptrace(struct task_struct *t)
2220 {
2221 	struct audit_context *context = current->audit_context;
2222 
2223 	context->target_pid = task_tgid_nr(t);
2224 	context->target_auid = audit_get_loginuid(t);
2225 	context->target_uid = task_uid(t);
2226 	context->target_sessionid = audit_get_sessionid(t);
2227 	security_task_getsecid(t, &context->target_sid);
2228 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
2229 }
2230 
2231 /**
2232  * audit_signal_info - record signal info for shutting down audit subsystem
2233  * @sig: signal value
2234  * @t: task being signaled
2235  *
2236  * If the audit subsystem is being terminated, record the task (pid)
2237  * and uid that is doing that.
2238  */
2239 int __audit_signal_info(int sig, struct task_struct *t)
2240 {
2241 	struct audit_aux_data_pids *axp;
2242 	struct task_struct *tsk = current;
2243 	struct audit_context *ctx = tsk->audit_context;
2244 	kuid_t uid = current_uid(), t_uid = task_uid(t);
2245 
2246 	if (audit_pid && t->tgid == audit_pid) {
2247 		if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) {
2248 			audit_sig_pid = task_tgid_nr(tsk);
2249 			if (uid_valid(tsk->loginuid))
2250 				audit_sig_uid = tsk->loginuid;
2251 			else
2252 				audit_sig_uid = uid;
2253 			security_task_getsecid(tsk, &audit_sig_sid);
2254 		}
2255 		if (!audit_signals || audit_dummy_context())
2256 			return 0;
2257 	}
2258 
2259 	/* optimize the common case by putting first signal recipient directly
2260 	 * in audit_context */
2261 	if (!ctx->target_pid) {
2262 		ctx->target_pid = task_tgid_nr(t);
2263 		ctx->target_auid = audit_get_loginuid(t);
2264 		ctx->target_uid = t_uid;
2265 		ctx->target_sessionid = audit_get_sessionid(t);
2266 		security_task_getsecid(t, &ctx->target_sid);
2267 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
2268 		return 0;
2269 	}
2270 
2271 	axp = (void *)ctx->aux_pids;
2272 	if (!axp || axp->pid_count == AUDIT_AUX_PIDS) {
2273 		axp = kzalloc(sizeof(*axp), GFP_ATOMIC);
2274 		if (!axp)
2275 			return -ENOMEM;
2276 
2277 		axp->d.type = AUDIT_OBJ_PID;
2278 		axp->d.next = ctx->aux_pids;
2279 		ctx->aux_pids = (void *)axp;
2280 	}
2281 	BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);
2282 
2283 	axp->target_pid[axp->pid_count] = task_tgid_nr(t);
2284 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
2285 	axp->target_uid[axp->pid_count] = t_uid;
2286 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
2287 	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
2288 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
2289 	axp->pid_count++;
2290 
2291 	return 0;
2292 }
2293 
2294 /**
2295  * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps
2296  * @bprm: pointer to the bprm being processed
2297  * @new: the proposed new credentials
2298  * @old: the old credentials
2299  *
2300  * Simply check if the proc already has the caps given by the file and if not
2301  * store the priv escalation info for later auditing at the end of the syscall
2302  *
2303  * -Eric
2304  */
2305 int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
2306 			   const struct cred *new, const struct cred *old)
2307 {
2308 	struct audit_aux_data_bprm_fcaps *ax;
2309 	struct audit_context *context = current->audit_context;
2310 	struct cpu_vfs_cap_data vcaps;
2311 
2312 	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2313 	if (!ax)
2314 		return -ENOMEM;
2315 
2316 	ax->d.type = AUDIT_BPRM_FCAPS;
2317 	ax->d.next = context->aux;
2318 	context->aux = (void *)ax;
2319 
2320 	get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps);
2321 
2322 	ax->fcap.permitted = vcaps.permitted;
2323 	ax->fcap.inheritable = vcaps.inheritable;
2324 	ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2325 	ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
2326 
2327 	ax->old_pcap.permitted   = old->cap_permitted;
2328 	ax->old_pcap.inheritable = old->cap_inheritable;
2329 	ax->old_pcap.effective   = old->cap_effective;
2330 
2331 	ax->new_pcap.permitted   = new->cap_permitted;
2332 	ax->new_pcap.inheritable = new->cap_inheritable;
2333 	ax->new_pcap.effective   = new->cap_effective;
2334 	return 0;
2335 }
2336 
2337 /**
2338  * __audit_log_capset - store information about the arguments to the capset syscall
2339  * @new: the new credentials
2340  * @old: the old (current) credentials
2341  *
2342  * Record the arguments userspace sent to sys_capset for later printing by the
2343  * audit system if applicable
2344  */
2345 void __audit_log_capset(const struct cred *new, const struct cred *old)
2346 {
2347 	struct audit_context *context = current->audit_context;
2348 	context->capset.pid = task_tgid_nr(current);
2349 	context->capset.cap.effective   = new->cap_effective;
2350 	context->capset.cap.inheritable = new->cap_effective;
2351 	context->capset.cap.permitted   = new->cap_permitted;
2352 	context->type = AUDIT_CAPSET;
2353 }
2354 
2355 void __audit_mmap_fd(int fd, int flags)
2356 {
2357 	struct audit_context *context = current->audit_context;
2358 	context->mmap.fd = fd;
2359 	context->mmap.flags = flags;
2360 	context->type = AUDIT_MMAP;
2361 }
2362 
2363 static void audit_log_task(struct audit_buffer *ab)
2364 {
2365 	kuid_t auid, uid;
2366 	kgid_t gid;
2367 	unsigned int sessionid;
2368 	char comm[sizeof(current->comm)];
2369 
2370 	auid = audit_get_loginuid(current);
2371 	sessionid = audit_get_sessionid(current);
2372 	current_uid_gid(&uid, &gid);
2373 
2374 	audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
2375 			 from_kuid(&init_user_ns, auid),
2376 			 from_kuid(&init_user_ns, uid),
2377 			 from_kgid(&init_user_ns, gid),
2378 			 sessionid);
2379 	audit_log_task_context(ab);
2380 	audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
2381 	audit_log_untrustedstring(ab, get_task_comm(comm, current));
2382 	audit_log_d_path_exe(ab, current->mm);
2383 }
2384 
2385 /**
2386  * audit_core_dumps - record information about processes that end abnormally
2387  * @signr: signal value
2388  *
2389  * If a process ends with a core dump, something fishy is going on and we
2390  * should record the event for investigation.
2391  */
2392 void audit_core_dumps(long signr)
2393 {
2394 	struct audit_buffer *ab;
2395 
2396 	if (!audit_enabled)
2397 		return;
2398 
2399 	if (signr == SIGQUIT)	/* don't care for those */
2400 		return;
2401 
2402 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
2403 	if (unlikely(!ab))
2404 		return;
2405 	audit_log_task(ab);
2406 	audit_log_format(ab, " sig=%ld", signr);
2407 	audit_log_end(ab);
2408 }
2409 
2410 void __audit_seccomp(unsigned long syscall, long signr, int code)
2411 {
2412 	struct audit_buffer *ab;
2413 
2414 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
2415 	if (unlikely(!ab))
2416 		return;
2417 	audit_log_task(ab);
2418 	audit_log_format(ab, " sig=%ld arch=%x syscall=%ld compat=%d ip=0x%lx code=0x%x",
2419 			 signr, syscall_get_arch(), syscall,
2420 			 in_compat_syscall(), KSTK_EIP(current), code);
2421 	audit_log_end(ab);
2422 }
2423 
2424 struct list_head *audit_killed_trees(void)
2425 {
2426 	struct audit_context *ctx = current->audit_context;
2427 	if (likely(!ctx || !ctx->in_syscall))
2428 		return NULL;
2429 	return &ctx->killed_trees;
2430 }
2431