xref: /openbmc/linux/kernel/auditsc.c (revision 2c6467d2)
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 <linux/fsnotify_backend.h>
77 #include <uapi/linux/limits.h>
78 
79 #include "audit.h"
80 
81 /* flags stating the success for a syscall */
82 #define AUDITSC_INVALID 0
83 #define AUDITSC_SUCCESS 1
84 #define AUDITSC_FAILURE 2
85 
86 /* no execve audit message should be longer than this (userspace limits),
87  * see the note near the top of audit_log_execve_info() about this value */
88 #define MAX_EXECVE_AUDIT_LEN 7500
89 
90 /* max length to print of cmdline/proctitle value during audit */
91 #define MAX_PROCTITLE_AUDIT_LEN 128
92 
93 /* number of audit rules */
94 int audit_n_rules;
95 
96 /* determines whether we collect data for signals sent */
97 int audit_signals;
98 
99 struct audit_aux_data {
100 	struct audit_aux_data	*next;
101 	int			type;
102 };
103 
104 #define AUDIT_AUX_IPCPERM	0
105 
106 /* Number of target pids per aux struct. */
107 #define AUDIT_AUX_PIDS	16
108 
109 struct audit_aux_data_pids {
110 	struct audit_aux_data	d;
111 	pid_t			target_pid[AUDIT_AUX_PIDS];
112 	kuid_t			target_auid[AUDIT_AUX_PIDS];
113 	kuid_t			target_uid[AUDIT_AUX_PIDS];
114 	unsigned int		target_sessionid[AUDIT_AUX_PIDS];
115 	u32			target_sid[AUDIT_AUX_PIDS];
116 	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
117 	int			pid_count;
118 };
119 
120 struct audit_aux_data_bprm_fcaps {
121 	struct audit_aux_data	d;
122 	struct audit_cap_data	fcap;
123 	unsigned int		fcap_ver;
124 	struct audit_cap_data	old_pcap;
125 	struct audit_cap_data	new_pcap;
126 };
127 
128 struct audit_tree_refs {
129 	struct audit_tree_refs *next;
130 	struct audit_chunk *c[31];
131 };
132 
133 static int audit_match_perm(struct audit_context *ctx, int mask)
134 {
135 	unsigned n;
136 	if (unlikely(!ctx))
137 		return 0;
138 	n = ctx->major;
139 
140 	switch (audit_classify_syscall(ctx->arch, n)) {
141 	case 0:	/* native */
142 		if ((mask & AUDIT_PERM_WRITE) &&
143 		     audit_match_class(AUDIT_CLASS_WRITE, n))
144 			return 1;
145 		if ((mask & AUDIT_PERM_READ) &&
146 		     audit_match_class(AUDIT_CLASS_READ, n))
147 			return 1;
148 		if ((mask & AUDIT_PERM_ATTR) &&
149 		     audit_match_class(AUDIT_CLASS_CHATTR, n))
150 			return 1;
151 		return 0;
152 	case 1: /* 32bit on biarch */
153 		if ((mask & AUDIT_PERM_WRITE) &&
154 		     audit_match_class(AUDIT_CLASS_WRITE_32, n))
155 			return 1;
156 		if ((mask & AUDIT_PERM_READ) &&
157 		     audit_match_class(AUDIT_CLASS_READ_32, n))
158 			return 1;
159 		if ((mask & AUDIT_PERM_ATTR) &&
160 		     audit_match_class(AUDIT_CLASS_CHATTR_32, n))
161 			return 1;
162 		return 0;
163 	case 2: /* open */
164 		return mask & ACC_MODE(ctx->argv[1]);
165 	case 3: /* openat */
166 		return mask & ACC_MODE(ctx->argv[2]);
167 	case 4: /* socketcall */
168 		return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND);
169 	case 5: /* execve */
170 		return mask & AUDIT_PERM_EXEC;
171 	default:
172 		return 0;
173 	}
174 }
175 
176 static int audit_match_filetype(struct audit_context *ctx, int val)
177 {
178 	struct audit_names *n;
179 	umode_t mode = (umode_t)val;
180 
181 	if (unlikely(!ctx))
182 		return 0;
183 
184 	list_for_each_entry(n, &ctx->names_list, list) {
185 		if ((n->ino != AUDIT_INO_UNSET) &&
186 		    ((n->mode & S_IFMT) == mode))
187 			return 1;
188 	}
189 
190 	return 0;
191 }
192 
193 /*
194  * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
195  * ->first_trees points to its beginning, ->trees - to the current end of data.
196  * ->tree_count is the number of free entries in array pointed to by ->trees.
197  * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
198  * "empty" becomes (p, p, 31) afterwards.  We don't shrink the list (and seriously,
199  * it's going to remain 1-element for almost any setup) until we free context itself.
200  * References in it _are_ dropped - at the same time we free/drop aux stuff.
201  */
202 
203 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 
248 static void unroll_tree_refs(struct audit_context *ctx,
249 		      struct audit_tree_refs *p, int count)
250 {
251 	struct audit_tree_refs *q;
252 	int n;
253 	if (!p) {
254 		/* we started with empty chain */
255 		p = ctx->first_trees;
256 		count = 31;
257 		/* if the very first allocation has failed, nothing to do */
258 		if (!p)
259 			return;
260 	}
261 	n = count;
262 	for (q = p; q != ctx->trees; q = q->next, n = 31) {
263 		while (n--) {
264 			audit_put_chunk(q->c[n]);
265 			q->c[n] = NULL;
266 		}
267 	}
268 	while (n-- > ctx->tree_count) {
269 		audit_put_chunk(q->c[n]);
270 		q->c[n] = NULL;
271 	}
272 	ctx->trees = p;
273 	ctx->tree_count = count;
274 }
275 
276 static void free_tree_refs(struct audit_context *ctx)
277 {
278 	struct audit_tree_refs *p, *q;
279 	for (p = ctx->first_trees; p; p = q) {
280 		q = p->next;
281 		kfree(p);
282 	}
283 }
284 
285 static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
286 {
287 	struct audit_tree_refs *p;
288 	int n;
289 	if (!tree)
290 		return 0;
291 	/* full ones */
292 	for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
293 		for (n = 0; n < 31; n++)
294 			if (audit_tree_match(p->c[n], tree))
295 				return 1;
296 	}
297 	/* partial */
298 	if (p) {
299 		for (n = ctx->tree_count; n < 31; n++)
300 			if (audit_tree_match(p->c[n], tree))
301 				return 1;
302 	}
303 	return 0;
304 }
305 
306 static int audit_compare_uid(kuid_t uid,
307 			     struct audit_names *name,
308 			     struct audit_field *f,
309 			     struct audit_context *ctx)
310 {
311 	struct audit_names *n;
312 	int rc;
313 
314 	if (name) {
315 		rc = audit_uid_comparator(uid, f->op, name->uid);
316 		if (rc)
317 			return rc;
318 	}
319 
320 	if (ctx) {
321 		list_for_each_entry(n, &ctx->names_list, list) {
322 			rc = audit_uid_comparator(uid, f->op, n->uid);
323 			if (rc)
324 				return rc;
325 		}
326 	}
327 	return 0;
328 }
329 
330 static int audit_compare_gid(kgid_t gid,
331 			     struct audit_names *name,
332 			     struct audit_field *f,
333 			     struct audit_context *ctx)
334 {
335 	struct audit_names *n;
336 	int rc;
337 
338 	if (name) {
339 		rc = audit_gid_comparator(gid, f->op, name->gid);
340 		if (rc)
341 			return rc;
342 	}
343 
344 	if (ctx) {
345 		list_for_each_entry(n, &ctx->names_list, list) {
346 			rc = audit_gid_comparator(gid, f->op, n->gid);
347 			if (rc)
348 				return rc;
349 		}
350 	}
351 	return 0;
352 }
353 
354 static int audit_field_compare(struct task_struct *tsk,
355 			       const struct cred *cred,
356 			       struct audit_field *f,
357 			       struct audit_context *ctx,
358 			       struct audit_names *name)
359 {
360 	switch (f->val) {
361 	/* process to file object comparisons */
362 	case AUDIT_COMPARE_UID_TO_OBJ_UID:
363 		return audit_compare_uid(cred->uid, name, f, ctx);
364 	case AUDIT_COMPARE_GID_TO_OBJ_GID:
365 		return audit_compare_gid(cred->gid, name, f, ctx);
366 	case AUDIT_COMPARE_EUID_TO_OBJ_UID:
367 		return audit_compare_uid(cred->euid, name, f, ctx);
368 	case AUDIT_COMPARE_EGID_TO_OBJ_GID:
369 		return audit_compare_gid(cred->egid, name, f, ctx);
370 	case AUDIT_COMPARE_AUID_TO_OBJ_UID:
371 		return audit_compare_uid(audit_get_loginuid(tsk), name, f, ctx);
372 	case AUDIT_COMPARE_SUID_TO_OBJ_UID:
373 		return audit_compare_uid(cred->suid, name, f, ctx);
374 	case AUDIT_COMPARE_SGID_TO_OBJ_GID:
375 		return audit_compare_gid(cred->sgid, name, f, ctx);
376 	case AUDIT_COMPARE_FSUID_TO_OBJ_UID:
377 		return audit_compare_uid(cred->fsuid, name, f, ctx);
378 	case AUDIT_COMPARE_FSGID_TO_OBJ_GID:
379 		return audit_compare_gid(cred->fsgid, name, f, ctx);
380 	/* uid comparisons */
381 	case AUDIT_COMPARE_UID_TO_AUID:
382 		return audit_uid_comparator(cred->uid, f->op,
383 					    audit_get_loginuid(tsk));
384 	case AUDIT_COMPARE_UID_TO_EUID:
385 		return audit_uid_comparator(cred->uid, f->op, cred->euid);
386 	case AUDIT_COMPARE_UID_TO_SUID:
387 		return audit_uid_comparator(cred->uid, f->op, cred->suid);
388 	case AUDIT_COMPARE_UID_TO_FSUID:
389 		return audit_uid_comparator(cred->uid, f->op, cred->fsuid);
390 	/* auid comparisons */
391 	case AUDIT_COMPARE_AUID_TO_EUID:
392 		return audit_uid_comparator(audit_get_loginuid(tsk), f->op,
393 					    cred->euid);
394 	case AUDIT_COMPARE_AUID_TO_SUID:
395 		return audit_uid_comparator(audit_get_loginuid(tsk), f->op,
396 					    cred->suid);
397 	case AUDIT_COMPARE_AUID_TO_FSUID:
398 		return audit_uid_comparator(audit_get_loginuid(tsk), f->op,
399 					    cred->fsuid);
400 	/* euid comparisons */
401 	case AUDIT_COMPARE_EUID_TO_SUID:
402 		return audit_uid_comparator(cred->euid, f->op, cred->suid);
403 	case AUDIT_COMPARE_EUID_TO_FSUID:
404 		return audit_uid_comparator(cred->euid, f->op, cred->fsuid);
405 	/* suid comparisons */
406 	case AUDIT_COMPARE_SUID_TO_FSUID:
407 		return audit_uid_comparator(cred->suid, f->op, cred->fsuid);
408 	/* gid comparisons */
409 	case AUDIT_COMPARE_GID_TO_EGID:
410 		return audit_gid_comparator(cred->gid, f->op, cred->egid);
411 	case AUDIT_COMPARE_GID_TO_SGID:
412 		return audit_gid_comparator(cred->gid, f->op, cred->sgid);
413 	case AUDIT_COMPARE_GID_TO_FSGID:
414 		return audit_gid_comparator(cred->gid, f->op, cred->fsgid);
415 	/* egid comparisons */
416 	case AUDIT_COMPARE_EGID_TO_SGID:
417 		return audit_gid_comparator(cred->egid, f->op, cred->sgid);
418 	case AUDIT_COMPARE_EGID_TO_FSGID:
419 		return audit_gid_comparator(cred->egid, f->op, cred->fsgid);
420 	/* sgid comparison */
421 	case AUDIT_COMPARE_SGID_TO_FSGID:
422 		return audit_gid_comparator(cred->sgid, f->op, cred->fsgid);
423 	default:
424 		WARN(1, "Missing AUDIT_COMPARE define.  Report as a bug\n");
425 		return 0;
426 	}
427 	return 0;
428 }
429 
430 /* Determine if any context name data matches a rule's watch data */
431 /* Compare a task_struct with an audit_rule.  Return 1 on match, 0
432  * otherwise.
433  *
434  * If task_creation is true, this is an explicit indication that we are
435  * filtering a task rule at task creation time.  This and tsk == current are
436  * the only situations where tsk->cred may be accessed without an rcu read lock.
437  */
438 static int audit_filter_rules(struct task_struct *tsk,
439 			      struct audit_krule *rule,
440 			      struct audit_context *ctx,
441 			      struct audit_names *name,
442 			      enum audit_state *state,
443 			      bool task_creation)
444 {
445 	const struct cred *cred;
446 	int i, need_sid = 1;
447 	u32 sid;
448 	unsigned int sessionid;
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 			if (f->op == Audit_not_equal)
473 				result = !result;
474 			break;
475 		case AUDIT_UID:
476 			result = audit_uid_comparator(cred->uid, f->op, f->uid);
477 			break;
478 		case AUDIT_EUID:
479 			result = audit_uid_comparator(cred->euid, f->op, f->uid);
480 			break;
481 		case AUDIT_SUID:
482 			result = audit_uid_comparator(cred->suid, f->op, f->uid);
483 			break;
484 		case AUDIT_FSUID:
485 			result = audit_uid_comparator(cred->fsuid, f->op, f->uid);
486 			break;
487 		case AUDIT_GID:
488 			result = audit_gid_comparator(cred->gid, f->op, f->gid);
489 			if (f->op == Audit_equal) {
490 				if (!result)
491 					result = groups_search(cred->group_info, f->gid);
492 			} else if (f->op == Audit_not_equal) {
493 				if (result)
494 					result = !groups_search(cred->group_info, f->gid);
495 			}
496 			break;
497 		case AUDIT_EGID:
498 			result = audit_gid_comparator(cred->egid, f->op, f->gid);
499 			if (f->op == Audit_equal) {
500 				if (!result)
501 					result = groups_search(cred->group_info, f->gid);
502 			} else if (f->op == Audit_not_equal) {
503 				if (result)
504 					result = !groups_search(cred->group_info, f->gid);
505 			}
506 			break;
507 		case AUDIT_SGID:
508 			result = audit_gid_comparator(cred->sgid, f->op, f->gid);
509 			break;
510 		case AUDIT_FSGID:
511 			result = audit_gid_comparator(cred->fsgid, f->op, f->gid);
512 			break;
513 		case AUDIT_SESSIONID:
514 			sessionid = audit_get_sessionid(tsk);
515 			result = audit_comparator(sessionid, f->op, f->val);
516 			break;
517 		case AUDIT_PERS:
518 			result = audit_comparator(tsk->personality, f->op, f->val);
519 			break;
520 		case AUDIT_ARCH:
521 			if (ctx)
522 				result = audit_comparator(ctx->arch, f->op, f->val);
523 			break;
524 
525 		case AUDIT_EXIT:
526 			if (ctx && ctx->return_valid)
527 				result = audit_comparator(ctx->return_code, f->op, f->val);
528 			break;
529 		case AUDIT_SUCCESS:
530 			if (ctx && ctx->return_valid) {
531 				if (f->val)
532 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
533 				else
534 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);
535 			}
536 			break;
537 		case AUDIT_DEVMAJOR:
538 			if (name) {
539 				if (audit_comparator(MAJOR(name->dev), f->op, f->val) ||
540 				    audit_comparator(MAJOR(name->rdev), f->op, f->val))
541 					++result;
542 			} else if (ctx) {
543 				list_for_each_entry(n, &ctx->names_list, list) {
544 					if (audit_comparator(MAJOR(n->dev), f->op, f->val) ||
545 					    audit_comparator(MAJOR(n->rdev), f->op, f->val)) {
546 						++result;
547 						break;
548 					}
549 				}
550 			}
551 			break;
552 		case AUDIT_DEVMINOR:
553 			if (name) {
554 				if (audit_comparator(MINOR(name->dev), f->op, f->val) ||
555 				    audit_comparator(MINOR(name->rdev), f->op, f->val))
556 					++result;
557 			} else if (ctx) {
558 				list_for_each_entry(n, &ctx->names_list, list) {
559 					if (audit_comparator(MINOR(n->dev), f->op, f->val) ||
560 					    audit_comparator(MINOR(n->rdev), f->op, f->val)) {
561 						++result;
562 						break;
563 					}
564 				}
565 			}
566 			break;
567 		case AUDIT_INODE:
568 			if (name)
569 				result = audit_comparator(name->ino, f->op, f->val);
570 			else if (ctx) {
571 				list_for_each_entry(n, &ctx->names_list, list) {
572 					if (audit_comparator(n->ino, f->op, f->val)) {
573 						++result;
574 						break;
575 					}
576 				}
577 			}
578 			break;
579 		case AUDIT_OBJ_UID:
580 			if (name) {
581 				result = audit_uid_comparator(name->uid, f->op, f->uid);
582 			} else if (ctx) {
583 				list_for_each_entry(n, &ctx->names_list, list) {
584 					if (audit_uid_comparator(n->uid, f->op, f->uid)) {
585 						++result;
586 						break;
587 					}
588 				}
589 			}
590 			break;
591 		case AUDIT_OBJ_GID:
592 			if (name) {
593 				result = audit_gid_comparator(name->gid, f->op, f->gid);
594 			} else if (ctx) {
595 				list_for_each_entry(n, &ctx->names_list, list) {
596 					if (audit_gid_comparator(n->gid, f->op, f->gid)) {
597 						++result;
598 						break;
599 					}
600 				}
601 			}
602 			break;
603 		case AUDIT_WATCH:
604 			if (name)
605 				result = audit_watch_compare(rule->watch, name->ino, name->dev);
606 			break;
607 		case AUDIT_DIR:
608 			if (ctx)
609 				result = match_tree_refs(ctx, rule->tree);
610 			break;
611 		case AUDIT_LOGINUID:
612 			result = audit_uid_comparator(audit_get_loginuid(tsk),
613 						      f->op, f->uid);
614 			break;
615 		case AUDIT_LOGINUID_SET:
616 			result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
617 			break;
618 		case AUDIT_SUBJ_USER:
619 		case AUDIT_SUBJ_ROLE:
620 		case AUDIT_SUBJ_TYPE:
621 		case AUDIT_SUBJ_SEN:
622 		case AUDIT_SUBJ_CLR:
623 			/* NOTE: this may return negative values indicating
624 			   a temporary error.  We simply treat this as a
625 			   match for now to avoid losing information that
626 			   may be wanted.   An error message will also be
627 			   logged upon error */
628 			if (f->lsm_rule) {
629 				if (need_sid) {
630 					security_task_getsecid(tsk, &sid);
631 					need_sid = 0;
632 				}
633 				result = security_audit_rule_match(sid, f->type,
634 				                                  f->op,
635 				                                  f->lsm_rule,
636 				                                  ctx);
637 			}
638 			break;
639 		case AUDIT_OBJ_USER:
640 		case AUDIT_OBJ_ROLE:
641 		case AUDIT_OBJ_TYPE:
642 		case AUDIT_OBJ_LEV_LOW:
643 		case AUDIT_OBJ_LEV_HIGH:
644 			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
645 			   also applies here */
646 			if (f->lsm_rule) {
647 				/* Find files that match */
648 				if (name) {
649 					result = security_audit_rule_match(
650 					           name->osid, f->type, f->op,
651 					           f->lsm_rule, ctx);
652 				} else if (ctx) {
653 					list_for_each_entry(n, &ctx->names_list, list) {
654 						if (security_audit_rule_match(n->osid, f->type,
655 									      f->op, f->lsm_rule,
656 									      ctx)) {
657 							++result;
658 							break;
659 						}
660 					}
661 				}
662 				/* Find ipc objects that match */
663 				if (!ctx || ctx->type != AUDIT_IPC)
664 					break;
665 				if (security_audit_rule_match(ctx->ipc.osid,
666 							      f->type, f->op,
667 							      f->lsm_rule, ctx))
668 					++result;
669 			}
670 			break;
671 		case AUDIT_ARG0:
672 		case AUDIT_ARG1:
673 		case AUDIT_ARG2:
674 		case AUDIT_ARG3:
675 			if (ctx)
676 				result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
677 			break;
678 		case AUDIT_FILTERKEY:
679 			/* ignore this field for filtering */
680 			result = 1;
681 			break;
682 		case AUDIT_PERM:
683 			result = audit_match_perm(ctx, f->val);
684 			break;
685 		case AUDIT_FILETYPE:
686 			result = audit_match_filetype(ctx, f->val);
687 			break;
688 		case AUDIT_FIELD_COMPARE:
689 			result = audit_field_compare(tsk, cred, f, ctx, name);
690 			break;
691 		}
692 		if (!result)
693 			return 0;
694 	}
695 
696 	if (ctx) {
697 		if (rule->prio <= ctx->prio)
698 			return 0;
699 		if (rule->filterkey) {
700 			kfree(ctx->filterkey);
701 			ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
702 		}
703 		ctx->prio = rule->prio;
704 	}
705 	switch (rule->action) {
706 	case AUDIT_NEVER:
707 		*state = AUDIT_DISABLED;
708 		break;
709 	case AUDIT_ALWAYS:
710 		*state = AUDIT_RECORD_CONTEXT;
711 		break;
712 	}
713 	return 1;
714 }
715 
716 /* At process creation time, we can determine if system-call auditing is
717  * completely disabled for this task.  Since we only have the task
718  * structure at this point, we can only check uid and gid.
719  */
720 static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
721 {
722 	struct audit_entry *e;
723 	enum audit_state   state;
724 
725 	rcu_read_lock();
726 	list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
727 		if (audit_filter_rules(tsk, &e->rule, NULL, NULL,
728 				       &state, true)) {
729 			if (state == AUDIT_RECORD_CONTEXT)
730 				*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
731 			rcu_read_unlock();
732 			return state;
733 		}
734 	}
735 	rcu_read_unlock();
736 	return AUDIT_BUILD_CONTEXT;
737 }
738 
739 static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
740 {
741 	int word, bit;
742 
743 	if (val > 0xffffffff)
744 		return false;
745 
746 	word = AUDIT_WORD(val);
747 	if (word >= AUDIT_BITMASK_SIZE)
748 		return false;
749 
750 	bit = AUDIT_BIT(val);
751 
752 	return rule->mask[word] & bit;
753 }
754 
755 /* At syscall entry and exit time, this filter is called if the
756  * audit_state is not low enough that auditing cannot take place, but is
757  * also not high enough that we already know we have to write an audit
758  * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
759  */
760 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
761 					     struct audit_context *ctx,
762 					     struct list_head *list)
763 {
764 	struct audit_entry *e;
765 	enum audit_state state;
766 
767 	if (auditd_test_task(tsk))
768 		return AUDIT_DISABLED;
769 
770 	rcu_read_lock();
771 	if (!list_empty(list)) {
772 		list_for_each_entry_rcu(e, list, list) {
773 			if (audit_in_mask(&e->rule, ctx->major) &&
774 			    audit_filter_rules(tsk, &e->rule, ctx, NULL,
775 					       &state, false)) {
776 				rcu_read_unlock();
777 				ctx->current_state = state;
778 				return state;
779 			}
780 		}
781 	}
782 	rcu_read_unlock();
783 	return AUDIT_BUILD_CONTEXT;
784 }
785 
786 /*
787  * Given an audit_name check the inode hash table to see if they match.
788  * Called holding the rcu read lock to protect the use of audit_inode_hash
789  */
790 static int audit_filter_inode_name(struct task_struct *tsk,
791 				   struct audit_names *n,
792 				   struct audit_context *ctx) {
793 	int h = audit_hash_ino((u32)n->ino);
794 	struct list_head *list = &audit_inode_hash[h];
795 	struct audit_entry *e;
796 	enum audit_state state;
797 
798 	if (list_empty(list))
799 		return 0;
800 
801 	list_for_each_entry_rcu(e, list, list) {
802 		if (audit_in_mask(&e->rule, ctx->major) &&
803 		    audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {
804 			ctx->current_state = state;
805 			return 1;
806 		}
807 	}
808 
809 	return 0;
810 }
811 
812 /* At syscall exit time, this filter is called if any audit_names have been
813  * collected during syscall processing.  We only check rules in sublists at hash
814  * buckets applicable to the inode numbers in audit_names.
815  * Regarding audit_state, same rules apply as for audit_filter_syscall().
816  */
817 void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
818 {
819 	struct audit_names *n;
820 
821 	if (auditd_test_task(tsk))
822 		return;
823 
824 	rcu_read_lock();
825 
826 	list_for_each_entry(n, &ctx->names_list, list) {
827 		if (audit_filter_inode_name(tsk, n, ctx))
828 			break;
829 	}
830 	rcu_read_unlock();
831 }
832 
833 static inline void audit_proctitle_free(struct audit_context *context)
834 {
835 	kfree(context->proctitle.value);
836 	context->proctitle.value = NULL;
837 	context->proctitle.len = 0;
838 }
839 
840 static inline void audit_free_names(struct audit_context *context)
841 {
842 	struct audit_names *n, *next;
843 
844 	list_for_each_entry_safe(n, next, &context->names_list, list) {
845 		list_del(&n->list);
846 		if (n->name)
847 			putname(n->name);
848 		if (n->should_free)
849 			kfree(n);
850 	}
851 	context->name_count = 0;
852 	path_put(&context->pwd);
853 	context->pwd.dentry = NULL;
854 	context->pwd.mnt = NULL;
855 }
856 
857 static inline void audit_free_aux(struct audit_context *context)
858 {
859 	struct audit_aux_data *aux;
860 
861 	while ((aux = context->aux)) {
862 		context->aux = aux->next;
863 		kfree(aux);
864 	}
865 	while ((aux = context->aux_pids)) {
866 		context->aux_pids = aux->next;
867 		kfree(aux);
868 	}
869 }
870 
871 static inline struct audit_context *audit_alloc_context(enum audit_state state)
872 {
873 	struct audit_context *context;
874 
875 	context = kzalloc(sizeof(*context), GFP_KERNEL);
876 	if (!context)
877 		return NULL;
878 	context->state = state;
879 	context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
880 	INIT_LIST_HEAD(&context->killed_trees);
881 	INIT_LIST_HEAD(&context->names_list);
882 	return context;
883 }
884 
885 /**
886  * audit_alloc - allocate an audit context block for a task
887  * @tsk: task
888  *
889  * Filter on the task information and allocate a per-task audit context
890  * if necessary.  Doing so turns on system call auditing for the
891  * specified task.  This is called from copy_process, so no lock is
892  * needed.
893  */
894 int audit_alloc(struct task_struct *tsk)
895 {
896 	struct audit_context *context;
897 	enum audit_state     state;
898 	char *key = NULL;
899 
900 	if (likely(!audit_ever_enabled))
901 		return 0; /* Return if not auditing. */
902 
903 	state = audit_filter_task(tsk, &key);
904 	if (state == AUDIT_DISABLED) {
905 		clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
906 		return 0;
907 	}
908 
909 	if (!(context = audit_alloc_context(state))) {
910 		kfree(key);
911 		audit_log_lost("out of memory in audit_alloc");
912 		return -ENOMEM;
913 	}
914 	context->filterkey = key;
915 
916 	audit_set_context(tsk, context);
917 	set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
918 	return 0;
919 }
920 
921 static inline void audit_free_context(struct audit_context *context)
922 {
923 	audit_free_names(context);
924 	unroll_tree_refs(context, NULL, 0);
925 	free_tree_refs(context);
926 	audit_free_aux(context);
927 	kfree(context->filterkey);
928 	kfree(context->sockaddr);
929 	audit_proctitle_free(context);
930 	kfree(context);
931 }
932 
933 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
934 				 kuid_t auid, kuid_t uid, unsigned int sessionid,
935 				 u32 sid, char *comm)
936 {
937 	struct audit_buffer *ab;
938 	char *ctx = NULL;
939 	u32 len;
940 	int rc = 0;
941 
942 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
943 	if (!ab)
944 		return rc;
945 
946 	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
947 			 from_kuid(&init_user_ns, auid),
948 			 from_kuid(&init_user_ns, uid), sessionid);
949 	if (sid) {
950 		if (security_secid_to_secctx(sid, &ctx, &len)) {
951 			audit_log_format(ab, " obj=(none)");
952 			rc = 1;
953 		} else {
954 			audit_log_format(ab, " obj=%s", ctx);
955 			security_release_secctx(ctx, len);
956 		}
957 	}
958 	audit_log_format(ab, " ocomm=");
959 	audit_log_untrustedstring(ab, comm);
960 	audit_log_end(ab);
961 
962 	return rc;
963 }
964 
965 static void audit_log_execve_info(struct audit_context *context,
966 				  struct audit_buffer **ab)
967 {
968 	long len_max;
969 	long len_rem;
970 	long len_full;
971 	long len_buf;
972 	long len_abuf = 0;
973 	long len_tmp;
974 	bool require_data;
975 	bool encode;
976 	unsigned int iter;
977 	unsigned int arg;
978 	char *buf_head;
979 	char *buf;
980 	const char __user *p = (const char __user *)current->mm->arg_start;
981 
982 	/* NOTE: this buffer needs to be large enough to hold all the non-arg
983 	 *       data we put in the audit record for this argument (see the
984 	 *       code below) ... at this point in time 96 is plenty */
985 	char abuf[96];
986 
987 	/* NOTE: we set MAX_EXECVE_AUDIT_LEN to a rather arbitrary limit, the
988 	 *       current value of 7500 is not as important as the fact that it
989 	 *       is less than 8k, a setting of 7500 gives us plenty of wiggle
990 	 *       room if we go over a little bit in the logging below */
991 	WARN_ON_ONCE(MAX_EXECVE_AUDIT_LEN > 7500);
992 	len_max = MAX_EXECVE_AUDIT_LEN;
993 
994 	/* scratch buffer to hold the userspace args */
995 	buf_head = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL);
996 	if (!buf_head) {
997 		audit_panic("out of memory for argv string");
998 		return;
999 	}
1000 	buf = buf_head;
1001 
1002 	audit_log_format(*ab, "argc=%d", context->execve.argc);
1003 
1004 	len_rem = len_max;
1005 	len_buf = 0;
1006 	len_full = 0;
1007 	require_data = true;
1008 	encode = false;
1009 	iter = 0;
1010 	arg = 0;
1011 	do {
1012 		/* NOTE: we don't ever want to trust this value for anything
1013 		 *       serious, but the audit record format insists we
1014 		 *       provide an argument length for really long arguments,
1015 		 *       e.g. > MAX_EXECVE_AUDIT_LEN, so we have no choice but
1016 		 *       to use strncpy_from_user() to obtain this value for
1017 		 *       recording in the log, although we don't use it
1018 		 *       anywhere here to avoid a double-fetch problem */
1019 		if (len_full == 0)
1020 			len_full = strnlen_user(p, MAX_ARG_STRLEN) - 1;
1021 
1022 		/* read more data from userspace */
1023 		if (require_data) {
1024 			/* can we make more room in the buffer? */
1025 			if (buf != buf_head) {
1026 				memmove(buf_head, buf, len_buf);
1027 				buf = buf_head;
1028 			}
1029 
1030 			/* fetch as much as we can of the argument */
1031 			len_tmp = strncpy_from_user(&buf_head[len_buf], p,
1032 						    len_max - len_buf);
1033 			if (len_tmp == -EFAULT) {
1034 				/* unable to copy from userspace */
1035 				send_sig(SIGKILL, current, 0);
1036 				goto out;
1037 			} else if (len_tmp == (len_max - len_buf)) {
1038 				/* buffer is not large enough */
1039 				require_data = true;
1040 				/* NOTE: if we are going to span multiple
1041 				 *       buffers force the encoding so we stand
1042 				 *       a chance at a sane len_full value and
1043 				 *       consistent record encoding */
1044 				encode = true;
1045 				len_full = len_full * 2;
1046 				p += len_tmp;
1047 			} else {
1048 				require_data = false;
1049 				if (!encode)
1050 					encode = audit_string_contains_control(
1051 								buf, len_tmp);
1052 				/* try to use a trusted value for len_full */
1053 				if (len_full < len_max)
1054 					len_full = (encode ?
1055 						    len_tmp * 2 : len_tmp);
1056 				p += len_tmp + 1;
1057 			}
1058 			len_buf += len_tmp;
1059 			buf_head[len_buf] = '\0';
1060 
1061 			/* length of the buffer in the audit record? */
1062 			len_abuf = (encode ? len_buf * 2 : len_buf + 2);
1063 		}
1064 
1065 		/* write as much as we can to the audit log */
1066 		if (len_buf >= 0) {
1067 			/* NOTE: some magic numbers here - basically if we
1068 			 *       can't fit a reasonable amount of data into the
1069 			 *       existing audit buffer, flush it and start with
1070 			 *       a new buffer */
1071 			if ((sizeof(abuf) + 8) > len_rem) {
1072 				len_rem = len_max;
1073 				audit_log_end(*ab);
1074 				*ab = audit_log_start(context,
1075 						      GFP_KERNEL, AUDIT_EXECVE);
1076 				if (!*ab)
1077 					goto out;
1078 			}
1079 
1080 			/* create the non-arg portion of the arg record */
1081 			len_tmp = 0;
1082 			if (require_data || (iter > 0) ||
1083 			    ((len_abuf + sizeof(abuf)) > len_rem)) {
1084 				if (iter == 0) {
1085 					len_tmp += snprintf(&abuf[len_tmp],
1086 							sizeof(abuf) - len_tmp,
1087 							" a%d_len=%lu",
1088 							arg, len_full);
1089 				}
1090 				len_tmp += snprintf(&abuf[len_tmp],
1091 						    sizeof(abuf) - len_tmp,
1092 						    " a%d[%d]=", arg, iter++);
1093 			} else
1094 				len_tmp += snprintf(&abuf[len_tmp],
1095 						    sizeof(abuf) - len_tmp,
1096 						    " a%d=", arg);
1097 			WARN_ON(len_tmp >= sizeof(abuf));
1098 			abuf[sizeof(abuf) - 1] = '\0';
1099 
1100 			/* log the arg in the audit record */
1101 			audit_log_format(*ab, "%s", abuf);
1102 			len_rem -= len_tmp;
1103 			len_tmp = len_buf;
1104 			if (encode) {
1105 				if (len_abuf > len_rem)
1106 					len_tmp = len_rem / 2; /* encoding */
1107 				audit_log_n_hex(*ab, buf, len_tmp);
1108 				len_rem -= len_tmp * 2;
1109 				len_abuf -= len_tmp * 2;
1110 			} else {
1111 				if (len_abuf > len_rem)
1112 					len_tmp = len_rem - 2; /* quotes */
1113 				audit_log_n_string(*ab, buf, len_tmp);
1114 				len_rem -= len_tmp + 2;
1115 				/* don't subtract the "2" because we still need
1116 				 * to add quotes to the remaining string */
1117 				len_abuf -= len_tmp;
1118 			}
1119 			len_buf -= len_tmp;
1120 			buf += len_tmp;
1121 		}
1122 
1123 		/* ready to move to the next argument? */
1124 		if ((len_buf == 0) && !require_data) {
1125 			arg++;
1126 			iter = 0;
1127 			len_full = 0;
1128 			require_data = true;
1129 			encode = false;
1130 		}
1131 	} while (arg < context->execve.argc);
1132 
1133 	/* NOTE: the caller handles the final audit_log_end() call */
1134 
1135 out:
1136 	kfree(buf_head);
1137 }
1138 
1139 static void show_special(struct audit_context *context, int *call_panic)
1140 {
1141 	struct audit_buffer *ab;
1142 	int i;
1143 
1144 	ab = audit_log_start(context, GFP_KERNEL, context->type);
1145 	if (!ab)
1146 		return;
1147 
1148 	switch (context->type) {
1149 	case AUDIT_SOCKETCALL: {
1150 		int nargs = context->socketcall.nargs;
1151 		audit_log_format(ab, "nargs=%d", nargs);
1152 		for (i = 0; i < nargs; i++)
1153 			audit_log_format(ab, " a%d=%lx", i,
1154 				context->socketcall.args[i]);
1155 		break; }
1156 	case AUDIT_IPC: {
1157 		u32 osid = context->ipc.osid;
1158 
1159 		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
1160 				 from_kuid(&init_user_ns, context->ipc.uid),
1161 				 from_kgid(&init_user_ns, context->ipc.gid),
1162 				 context->ipc.mode);
1163 		if (osid) {
1164 			char *ctx = NULL;
1165 			u32 len;
1166 			if (security_secid_to_secctx(osid, &ctx, &len)) {
1167 				audit_log_format(ab, " osid=%u", osid);
1168 				*call_panic = 1;
1169 			} else {
1170 				audit_log_format(ab, " obj=%s", ctx);
1171 				security_release_secctx(ctx, len);
1172 			}
1173 		}
1174 		if (context->ipc.has_perm) {
1175 			audit_log_end(ab);
1176 			ab = audit_log_start(context, GFP_KERNEL,
1177 					     AUDIT_IPC_SET_PERM);
1178 			if (unlikely(!ab))
1179 				return;
1180 			audit_log_format(ab,
1181 				"qbytes=%lx ouid=%u ogid=%u mode=%#ho",
1182 				context->ipc.qbytes,
1183 				context->ipc.perm_uid,
1184 				context->ipc.perm_gid,
1185 				context->ipc.perm_mode);
1186 		}
1187 		break; }
1188 	case AUDIT_MQ_OPEN:
1189 		audit_log_format(ab,
1190 			"oflag=0x%x mode=%#ho mq_flags=0x%lx mq_maxmsg=%ld "
1191 			"mq_msgsize=%ld mq_curmsgs=%ld",
1192 			context->mq_open.oflag, context->mq_open.mode,
1193 			context->mq_open.attr.mq_flags,
1194 			context->mq_open.attr.mq_maxmsg,
1195 			context->mq_open.attr.mq_msgsize,
1196 			context->mq_open.attr.mq_curmsgs);
1197 		break;
1198 	case AUDIT_MQ_SENDRECV:
1199 		audit_log_format(ab,
1200 			"mqdes=%d msg_len=%zd msg_prio=%u "
1201 			"abs_timeout_sec=%lld abs_timeout_nsec=%ld",
1202 			context->mq_sendrecv.mqdes,
1203 			context->mq_sendrecv.msg_len,
1204 			context->mq_sendrecv.msg_prio,
1205 			(long long) context->mq_sendrecv.abs_timeout.tv_sec,
1206 			context->mq_sendrecv.abs_timeout.tv_nsec);
1207 		break;
1208 	case AUDIT_MQ_NOTIFY:
1209 		audit_log_format(ab, "mqdes=%d sigev_signo=%d",
1210 				context->mq_notify.mqdes,
1211 				context->mq_notify.sigev_signo);
1212 		break;
1213 	case AUDIT_MQ_GETSETATTR: {
1214 		struct mq_attr *attr = &context->mq_getsetattr.mqstat;
1215 		audit_log_format(ab,
1216 			"mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
1217 			"mq_curmsgs=%ld ",
1218 			context->mq_getsetattr.mqdes,
1219 			attr->mq_flags, attr->mq_maxmsg,
1220 			attr->mq_msgsize, attr->mq_curmsgs);
1221 		break; }
1222 	case AUDIT_CAPSET:
1223 		audit_log_format(ab, "pid=%d", context->capset.pid);
1224 		audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable);
1225 		audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted);
1226 		audit_log_cap(ab, "cap_pe", &context->capset.cap.effective);
1227 		audit_log_cap(ab, "cap_pa", &context->capset.cap.ambient);
1228 		break;
1229 	case AUDIT_MMAP:
1230 		audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd,
1231 				 context->mmap.flags);
1232 		break;
1233 	case AUDIT_EXECVE:
1234 		audit_log_execve_info(context, &ab);
1235 		break;
1236 	case AUDIT_KERN_MODULE:
1237 		audit_log_format(ab, "name=");
1238 		if (context->module.name) {
1239 			audit_log_untrustedstring(ab, context->module.name);
1240 			kfree(context->module.name);
1241 		} else
1242 			audit_log_format(ab, "(null)");
1243 
1244 		break;
1245 	}
1246 	audit_log_end(ab);
1247 }
1248 
1249 static inline int audit_proctitle_rtrim(char *proctitle, int len)
1250 {
1251 	char *end = proctitle + len - 1;
1252 	while (end > proctitle && !isprint(*end))
1253 		end--;
1254 
1255 	/* catch the case where proctitle is only 1 non-print character */
1256 	len = end - proctitle + 1;
1257 	len -= isprint(proctitle[len-1]) == 0;
1258 	return len;
1259 }
1260 
1261 static void audit_log_proctitle(void)
1262 {
1263 	int res;
1264 	char *buf;
1265 	char *msg = "(null)";
1266 	int len = strlen(msg);
1267 	struct audit_context *context = audit_context();
1268 	struct audit_buffer *ab;
1269 
1270 	if (!context || context->dummy)
1271 		return;
1272 
1273 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_PROCTITLE);
1274 	if (!ab)
1275 		return;	/* audit_panic or being filtered */
1276 
1277 	audit_log_format(ab, "proctitle=");
1278 
1279 	/* Not  cached */
1280 	if (!context->proctitle.value) {
1281 		buf = kmalloc(MAX_PROCTITLE_AUDIT_LEN, GFP_KERNEL);
1282 		if (!buf)
1283 			goto out;
1284 		/* Historically called this from procfs naming */
1285 		res = get_cmdline(current, buf, MAX_PROCTITLE_AUDIT_LEN);
1286 		if (res == 0) {
1287 			kfree(buf);
1288 			goto out;
1289 		}
1290 		res = audit_proctitle_rtrim(buf, res);
1291 		if (res == 0) {
1292 			kfree(buf);
1293 			goto out;
1294 		}
1295 		context->proctitle.value = buf;
1296 		context->proctitle.len = res;
1297 	}
1298 	msg = context->proctitle.value;
1299 	len = context->proctitle.len;
1300 out:
1301 	audit_log_n_untrustedstring(ab, msg, len);
1302 	audit_log_end(ab);
1303 }
1304 
1305 static void audit_log_exit(void)
1306 {
1307 	int i, call_panic = 0;
1308 	struct audit_context *context = audit_context();
1309 	struct audit_buffer *ab;
1310 	struct audit_aux_data *aux;
1311 	struct audit_names *n;
1312 
1313 	context->personality = current->personality;
1314 
1315 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
1316 	if (!ab)
1317 		return;		/* audit_panic has been called */
1318 	audit_log_format(ab, "arch=%x syscall=%d",
1319 			 context->arch, context->major);
1320 	if (context->personality != PER_LINUX)
1321 		audit_log_format(ab, " per=%lx", context->personality);
1322 	if (context->return_valid)
1323 		audit_log_format(ab, " success=%s exit=%ld",
1324 				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
1325 				 context->return_code);
1326 
1327 	audit_log_format(ab,
1328 			 " a0=%lx a1=%lx a2=%lx a3=%lx items=%d",
1329 			 context->argv[0],
1330 			 context->argv[1],
1331 			 context->argv[2],
1332 			 context->argv[3],
1333 			 context->name_count);
1334 
1335 	audit_log_task_info(ab);
1336 	audit_log_key(ab, context->filterkey);
1337 	audit_log_end(ab);
1338 
1339 	for (aux = context->aux; aux; aux = aux->next) {
1340 
1341 		ab = audit_log_start(context, GFP_KERNEL, aux->type);
1342 		if (!ab)
1343 			continue; /* audit_panic has been called */
1344 
1345 		switch (aux->type) {
1346 
1347 		case AUDIT_BPRM_FCAPS: {
1348 			struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
1349 			audit_log_format(ab, "fver=%x", axs->fcap_ver);
1350 			audit_log_cap(ab, "fp", &axs->fcap.permitted);
1351 			audit_log_cap(ab, "fi", &axs->fcap.inheritable);
1352 			audit_log_format(ab, " fe=%d", axs->fcap.fE);
1353 			audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted);
1354 			audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable);
1355 			audit_log_cap(ab, "old_pe", &axs->old_pcap.effective);
1356 			audit_log_cap(ab, "old_pa", &axs->old_pcap.ambient);
1357 			audit_log_cap(ab, "pp", &axs->new_pcap.permitted);
1358 			audit_log_cap(ab, "pi", &axs->new_pcap.inheritable);
1359 			audit_log_cap(ab, "pe", &axs->new_pcap.effective);
1360 			audit_log_cap(ab, "pa", &axs->new_pcap.ambient);
1361 			break; }
1362 
1363 		}
1364 		audit_log_end(ab);
1365 	}
1366 
1367 	if (context->type)
1368 		show_special(context, &call_panic);
1369 
1370 	if (context->fds[0] >= 0) {
1371 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR);
1372 		if (ab) {
1373 			audit_log_format(ab, "fd0=%d fd1=%d",
1374 					context->fds[0], context->fds[1]);
1375 			audit_log_end(ab);
1376 		}
1377 	}
1378 
1379 	if (context->sockaddr_len) {
1380 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
1381 		if (ab) {
1382 			audit_log_format(ab, "saddr=");
1383 			audit_log_n_hex(ab, (void *)context->sockaddr,
1384 					context->sockaddr_len);
1385 			audit_log_end(ab);
1386 		}
1387 	}
1388 
1389 	for (aux = context->aux_pids; aux; aux = aux->next) {
1390 		struct audit_aux_data_pids *axs = (void *)aux;
1391 
1392 		for (i = 0; i < axs->pid_count; i++)
1393 			if (audit_log_pid_context(context, axs->target_pid[i],
1394 						  axs->target_auid[i],
1395 						  axs->target_uid[i],
1396 						  axs->target_sessionid[i],
1397 						  axs->target_sid[i],
1398 						  axs->target_comm[i]))
1399 				call_panic = 1;
1400 	}
1401 
1402 	if (context->target_pid &&
1403 	    audit_log_pid_context(context, context->target_pid,
1404 				  context->target_auid, context->target_uid,
1405 				  context->target_sessionid,
1406 				  context->target_sid, context->target_comm))
1407 			call_panic = 1;
1408 
1409 	if (context->pwd.dentry && context->pwd.mnt) {
1410 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
1411 		if (ab) {
1412 			audit_log_d_path(ab, "cwd=", &context->pwd);
1413 			audit_log_end(ab);
1414 		}
1415 	}
1416 
1417 	i = 0;
1418 	list_for_each_entry(n, &context->names_list, list) {
1419 		if (n->hidden)
1420 			continue;
1421 		audit_log_name(context, n, NULL, i++, &call_panic);
1422 	}
1423 
1424 	audit_log_proctitle();
1425 
1426 	/* Send end of event record to help user space know we are finished */
1427 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
1428 	if (ab)
1429 		audit_log_end(ab);
1430 	if (call_panic)
1431 		audit_panic("error converting sid to string");
1432 }
1433 
1434 /**
1435  * __audit_free - free a per-task audit context
1436  * @tsk: task whose audit context block to free
1437  *
1438  * Called from copy_process and do_exit
1439  */
1440 void __audit_free(struct task_struct *tsk)
1441 {
1442 	struct audit_context *context = tsk->audit_context;
1443 
1444 	if (!context)
1445 		return;
1446 
1447 	/* We are called either by do_exit() or the fork() error handling code;
1448 	 * in the former case tsk == current and in the latter tsk is a
1449 	 * random task_struct that doesn't doesn't have any meaningful data we
1450 	 * need to log via audit_log_exit().
1451 	 */
1452 	if (tsk == current && !context->dummy && context->in_syscall) {
1453 		context->return_valid = 0;
1454 		context->return_code = 0;
1455 
1456 		audit_filter_syscall(tsk, context,
1457 				     &audit_filter_list[AUDIT_FILTER_EXIT]);
1458 		audit_filter_inodes(tsk, context);
1459 		if (context->current_state == AUDIT_RECORD_CONTEXT)
1460 			audit_log_exit();
1461 	}
1462 
1463 	if (!list_empty(&context->killed_trees))
1464 		audit_kill_trees(&context->killed_trees);
1465 
1466 	audit_set_context(tsk, NULL);
1467 	audit_free_context(context);
1468 }
1469 
1470 /**
1471  * __audit_syscall_entry - fill in an audit record at syscall entry
1472  * @major: major syscall type (function)
1473  * @a1: additional syscall register 1
1474  * @a2: additional syscall register 2
1475  * @a3: additional syscall register 3
1476  * @a4: additional syscall register 4
1477  *
1478  * Fill in audit context at syscall entry.  This only happens if the
1479  * audit context was created when the task was created and the state or
1480  * filters demand the audit context be built.  If the state from the
1481  * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1482  * then the record will be written at syscall exit time (otherwise, it
1483  * will only be written if another part of the kernel requests that it
1484  * be written).
1485  */
1486 void __audit_syscall_entry(int major, unsigned long a1, unsigned long a2,
1487 			   unsigned long a3, unsigned long a4)
1488 {
1489 	struct audit_context *context = audit_context();
1490 	enum audit_state     state;
1491 
1492 	if (!audit_enabled || !context)
1493 		return;
1494 
1495 	BUG_ON(context->in_syscall || context->name_count);
1496 
1497 	state = context->state;
1498 	if (state == AUDIT_DISABLED)
1499 		return;
1500 
1501 	context->dummy = !audit_n_rules;
1502 	if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
1503 		context->prio = 0;
1504 		if (auditd_test_task(current))
1505 			return;
1506 	}
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 	context->serial     = 0;
1515 	context->in_syscall = 1;
1516 	context->current_state  = state;
1517 	context->ppid       = 0;
1518 	ktime_get_coarse_real_ts64(&context->ctime);
1519 }
1520 
1521 /**
1522  * __audit_syscall_exit - deallocate audit context after a system call
1523  * @success: success value of the syscall
1524  * @return_code: return value of the syscall
1525  *
1526  * Tear down after system call.  If the audit context has been marked as
1527  * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1528  * filtering, or because some other part of the kernel wrote an audit
1529  * message), then write out the syscall information.  In call cases,
1530  * free the names stored from getname().
1531  */
1532 void __audit_syscall_exit(int success, long return_code)
1533 {
1534 	struct audit_context *context;
1535 
1536 	context = audit_context();
1537 	if (!context)
1538 		return;
1539 
1540 	if (!context->dummy && context->in_syscall) {
1541 		if (success)
1542 			context->return_valid = AUDITSC_SUCCESS;
1543 		else
1544 			context->return_valid = AUDITSC_FAILURE;
1545 
1546 		/*
1547 		 * we need to fix up the return code in the audit logs if the
1548 		 * actual return codes are later going to be fixed up by the
1549 		 * arch specific signal handlers
1550 		 *
1551 		 * This is actually a test for:
1552 		 * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) ||
1553 		 * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK)
1554 		 *
1555 		 * but is faster than a bunch of ||
1556 		 */
1557 		if (unlikely(return_code <= -ERESTARTSYS) &&
1558 		    (return_code >= -ERESTART_RESTARTBLOCK) &&
1559 		    (return_code != -ENOIOCTLCMD))
1560 			context->return_code = -EINTR;
1561 		else
1562 			context->return_code  = return_code;
1563 
1564 		audit_filter_syscall(current, context,
1565 				     &audit_filter_list[AUDIT_FILTER_EXIT]);
1566 		audit_filter_inodes(current, context);
1567 		if (context->current_state == AUDIT_RECORD_CONTEXT)
1568 			audit_log_exit();
1569 	}
1570 
1571 	context->in_syscall = 0;
1572 	context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
1573 
1574 	if (!list_empty(&context->killed_trees))
1575 		audit_kill_trees(&context->killed_trees);
1576 
1577 	audit_free_names(context);
1578 	unroll_tree_refs(context, NULL, 0);
1579 	audit_free_aux(context);
1580 	context->aux = NULL;
1581 	context->aux_pids = NULL;
1582 	context->target_pid = 0;
1583 	context->target_sid = 0;
1584 	context->sockaddr_len = 0;
1585 	context->type = 0;
1586 	context->fds[0] = -1;
1587 	if (context->state != AUDIT_RECORD_CONTEXT) {
1588 		kfree(context->filterkey);
1589 		context->filterkey = NULL;
1590 	}
1591 }
1592 
1593 static inline void handle_one(const struct inode *inode)
1594 {
1595 	struct audit_context *context;
1596 	struct audit_tree_refs *p;
1597 	struct audit_chunk *chunk;
1598 	int count;
1599 	if (likely(!inode->i_fsnotify_marks))
1600 		return;
1601 	context = audit_context();
1602 	p = context->trees;
1603 	count = context->tree_count;
1604 	rcu_read_lock();
1605 	chunk = audit_tree_lookup(inode);
1606 	rcu_read_unlock();
1607 	if (!chunk)
1608 		return;
1609 	if (likely(put_tree_ref(context, chunk)))
1610 		return;
1611 	if (unlikely(!grow_tree_refs(context))) {
1612 		pr_warn("out of memory, audit has lost a tree reference\n");
1613 		audit_set_auditable(context);
1614 		audit_put_chunk(chunk);
1615 		unroll_tree_refs(context, p, count);
1616 		return;
1617 	}
1618 	put_tree_ref(context, chunk);
1619 }
1620 
1621 static void handle_path(const struct dentry *dentry)
1622 {
1623 	struct audit_context *context;
1624 	struct audit_tree_refs *p;
1625 	const struct dentry *d, *parent;
1626 	struct audit_chunk *drop;
1627 	unsigned long seq;
1628 	int count;
1629 
1630 	context = audit_context();
1631 	p = context->trees;
1632 	count = context->tree_count;
1633 retry:
1634 	drop = NULL;
1635 	d = dentry;
1636 	rcu_read_lock();
1637 	seq = read_seqbegin(&rename_lock);
1638 	for(;;) {
1639 		struct inode *inode = d_backing_inode(d);
1640 		if (inode && unlikely(inode->i_fsnotify_marks)) {
1641 			struct audit_chunk *chunk;
1642 			chunk = audit_tree_lookup(inode);
1643 			if (chunk) {
1644 				if (unlikely(!put_tree_ref(context, chunk))) {
1645 					drop = chunk;
1646 					break;
1647 				}
1648 			}
1649 		}
1650 		parent = d->d_parent;
1651 		if (parent == d)
1652 			break;
1653 		d = parent;
1654 	}
1655 	if (unlikely(read_seqretry(&rename_lock, seq) || drop)) {  /* in this order */
1656 		rcu_read_unlock();
1657 		if (!drop) {
1658 			/* just a race with rename */
1659 			unroll_tree_refs(context, p, count);
1660 			goto retry;
1661 		}
1662 		audit_put_chunk(drop);
1663 		if (grow_tree_refs(context)) {
1664 			/* OK, got more space */
1665 			unroll_tree_refs(context, p, count);
1666 			goto retry;
1667 		}
1668 		/* too bad */
1669 		pr_warn("out of memory, audit has lost a tree reference\n");
1670 		unroll_tree_refs(context, p, count);
1671 		audit_set_auditable(context);
1672 		return;
1673 	}
1674 	rcu_read_unlock();
1675 }
1676 
1677 static struct audit_names *audit_alloc_name(struct audit_context *context,
1678 						unsigned char type)
1679 {
1680 	struct audit_names *aname;
1681 
1682 	if (context->name_count < AUDIT_NAMES) {
1683 		aname = &context->preallocated_names[context->name_count];
1684 		memset(aname, 0, sizeof(*aname));
1685 	} else {
1686 		aname = kzalloc(sizeof(*aname), GFP_NOFS);
1687 		if (!aname)
1688 			return NULL;
1689 		aname->should_free = true;
1690 	}
1691 
1692 	aname->ino = AUDIT_INO_UNSET;
1693 	aname->type = type;
1694 	list_add_tail(&aname->list, &context->names_list);
1695 
1696 	context->name_count++;
1697 	return aname;
1698 }
1699 
1700 /**
1701  * __audit_reusename - fill out filename with info from existing entry
1702  * @uptr: userland ptr to pathname
1703  *
1704  * Search the audit_names list for the current audit context. If there is an
1705  * existing entry with a matching "uptr" then return the filename
1706  * associated with that audit_name. If not, return NULL.
1707  */
1708 struct filename *
1709 __audit_reusename(const __user char *uptr)
1710 {
1711 	struct audit_context *context = audit_context();
1712 	struct audit_names *n;
1713 
1714 	list_for_each_entry(n, &context->names_list, list) {
1715 		if (!n->name)
1716 			continue;
1717 		if (n->name->uptr == uptr) {
1718 			n->name->refcnt++;
1719 			return n->name;
1720 		}
1721 	}
1722 	return NULL;
1723 }
1724 
1725 /**
1726  * __audit_getname - add a name to the list
1727  * @name: name to add
1728  *
1729  * Add a name to the list of audit names for this context.
1730  * Called from fs/namei.c:getname().
1731  */
1732 void __audit_getname(struct filename *name)
1733 {
1734 	struct audit_context *context = audit_context();
1735 	struct audit_names *n;
1736 
1737 	if (!context->in_syscall)
1738 		return;
1739 
1740 	n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1741 	if (!n)
1742 		return;
1743 
1744 	n->name = name;
1745 	n->name_len = AUDIT_NAME_FULL;
1746 	name->aname = n;
1747 	name->refcnt++;
1748 
1749 	if (!context->pwd.dentry)
1750 		get_fs_pwd(current->fs, &context->pwd);
1751 }
1752 
1753 /**
1754  * __audit_inode - store the inode and device from a lookup
1755  * @name: name being audited
1756  * @dentry: dentry being audited
1757  * @flags: attributes for this particular entry
1758  */
1759 void __audit_inode(struct filename *name, const struct dentry *dentry,
1760 		   unsigned int flags)
1761 {
1762 	struct audit_context *context = audit_context();
1763 	struct inode *inode = d_backing_inode(dentry);
1764 	struct audit_names *n;
1765 	bool parent = flags & AUDIT_INODE_PARENT;
1766 
1767 	if (!context->in_syscall)
1768 		return;
1769 
1770 	if (!name)
1771 		goto out_alloc;
1772 
1773 	/*
1774 	 * If we have a pointer to an audit_names entry already, then we can
1775 	 * just use it directly if the type is correct.
1776 	 */
1777 	n = name->aname;
1778 	if (n) {
1779 		if (parent) {
1780 			if (n->type == AUDIT_TYPE_PARENT ||
1781 			    n->type == AUDIT_TYPE_UNKNOWN)
1782 				goto out;
1783 		} else {
1784 			if (n->type != AUDIT_TYPE_PARENT)
1785 				goto out;
1786 		}
1787 	}
1788 
1789 	list_for_each_entry_reverse(n, &context->names_list, list) {
1790 		if (n->ino) {
1791 			/* valid inode number, use that for the comparison */
1792 			if (n->ino != inode->i_ino ||
1793 			    n->dev != inode->i_sb->s_dev)
1794 				continue;
1795 		} else if (n->name) {
1796 			/* inode number has not been set, check the name */
1797 			if (strcmp(n->name->name, name->name))
1798 				continue;
1799 		} else
1800 			/* no inode and no name (?!) ... this is odd ... */
1801 			continue;
1802 
1803 		/* match the correct record type */
1804 		if (parent) {
1805 			if (n->type == AUDIT_TYPE_PARENT ||
1806 			    n->type == AUDIT_TYPE_UNKNOWN)
1807 				goto out;
1808 		} else {
1809 			if (n->type != AUDIT_TYPE_PARENT)
1810 				goto out;
1811 		}
1812 	}
1813 
1814 out_alloc:
1815 	/* unable to find an entry with both a matching name and type */
1816 	n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1817 	if (!n)
1818 		return;
1819 	if (name) {
1820 		n->name = name;
1821 		name->refcnt++;
1822 	}
1823 
1824 out:
1825 	if (parent) {
1826 		n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL;
1827 		n->type = AUDIT_TYPE_PARENT;
1828 		if (flags & AUDIT_INODE_HIDDEN)
1829 			n->hidden = true;
1830 	} else {
1831 		n->name_len = AUDIT_NAME_FULL;
1832 		n->type = AUDIT_TYPE_NORMAL;
1833 	}
1834 	handle_path(dentry);
1835 	audit_copy_inode(n, dentry, inode);
1836 }
1837 
1838 void __audit_file(const struct file *file)
1839 {
1840 	__audit_inode(NULL, file->f_path.dentry, 0);
1841 }
1842 
1843 /**
1844  * __audit_inode_child - collect inode info for created/removed objects
1845  * @parent: inode of dentry parent
1846  * @dentry: dentry being audited
1847  * @type:   AUDIT_TYPE_* value that we're looking for
1848  *
1849  * For syscalls that create or remove filesystem objects, audit_inode
1850  * can only collect information for the filesystem object's parent.
1851  * This call updates the audit context with the child's information.
1852  * Syscalls that create a new filesystem object must be hooked after
1853  * the object is created.  Syscalls that remove a filesystem object
1854  * must be hooked prior, in order to capture the target inode during
1855  * unsuccessful attempts.
1856  */
1857 void __audit_inode_child(struct inode *parent,
1858 			 const struct dentry *dentry,
1859 			 const unsigned char type)
1860 {
1861 	struct audit_context *context = audit_context();
1862 	struct inode *inode = d_backing_inode(dentry);
1863 	const char *dname = dentry->d_name.name;
1864 	struct audit_names *n, *found_parent = NULL, *found_child = NULL;
1865 	struct audit_entry *e;
1866 	struct list_head *list = &audit_filter_list[AUDIT_FILTER_FS];
1867 	int i;
1868 
1869 	if (!context->in_syscall)
1870 		return;
1871 
1872 	rcu_read_lock();
1873 	if (!list_empty(list)) {
1874 		list_for_each_entry_rcu(e, list, list) {
1875 			for (i = 0; i < e->rule.field_count; i++) {
1876 				struct audit_field *f = &e->rule.fields[i];
1877 
1878 				if (f->type == AUDIT_FSTYPE) {
1879 					if (audit_comparator(parent->i_sb->s_magic,
1880 					    f->op, f->val)) {
1881 						if (e->rule.action == AUDIT_NEVER) {
1882 							rcu_read_unlock();
1883 							return;
1884 						}
1885 					}
1886 				}
1887 			}
1888 		}
1889 	}
1890 	rcu_read_unlock();
1891 
1892 	if (inode)
1893 		handle_one(inode);
1894 
1895 	/* look for a parent entry first */
1896 	list_for_each_entry(n, &context->names_list, list) {
1897 		if (!n->name ||
1898 		    (n->type != AUDIT_TYPE_PARENT &&
1899 		     n->type != AUDIT_TYPE_UNKNOWN))
1900 			continue;
1901 
1902 		if (n->ino == parent->i_ino && n->dev == parent->i_sb->s_dev &&
1903 		    !audit_compare_dname_path(dname,
1904 					      n->name->name, n->name_len)) {
1905 			if (n->type == AUDIT_TYPE_UNKNOWN)
1906 				n->type = AUDIT_TYPE_PARENT;
1907 			found_parent = n;
1908 			break;
1909 		}
1910 	}
1911 
1912 	/* is there a matching child entry? */
1913 	list_for_each_entry(n, &context->names_list, list) {
1914 		/* can only match entries that have a name */
1915 		if (!n->name ||
1916 		    (n->type != type && n->type != AUDIT_TYPE_UNKNOWN))
1917 			continue;
1918 
1919 		if (!strcmp(dname, n->name->name) ||
1920 		    !audit_compare_dname_path(dname, n->name->name,
1921 						found_parent ?
1922 						found_parent->name_len :
1923 						AUDIT_NAME_FULL)) {
1924 			if (n->type == AUDIT_TYPE_UNKNOWN)
1925 				n->type = type;
1926 			found_child = n;
1927 			break;
1928 		}
1929 	}
1930 
1931 	if (!found_parent) {
1932 		/* create a new, "anonymous" parent record */
1933 		n = audit_alloc_name(context, AUDIT_TYPE_PARENT);
1934 		if (!n)
1935 			return;
1936 		audit_copy_inode(n, NULL, parent);
1937 	}
1938 
1939 	if (!found_child) {
1940 		found_child = audit_alloc_name(context, type);
1941 		if (!found_child)
1942 			return;
1943 
1944 		/* Re-use the name belonging to the slot for a matching parent
1945 		 * directory. All names for this context are relinquished in
1946 		 * audit_free_names() */
1947 		if (found_parent) {
1948 			found_child->name = found_parent->name;
1949 			found_child->name_len = AUDIT_NAME_FULL;
1950 			found_child->name->refcnt++;
1951 		}
1952 	}
1953 
1954 	if (inode)
1955 		audit_copy_inode(found_child, dentry, inode);
1956 	else
1957 		found_child->ino = AUDIT_INO_UNSET;
1958 }
1959 EXPORT_SYMBOL_GPL(__audit_inode_child);
1960 
1961 /**
1962  * auditsc_get_stamp - get local copies of audit_context values
1963  * @ctx: audit_context for the task
1964  * @t: timespec64 to store time recorded in the audit_context
1965  * @serial: serial value that is recorded in the audit_context
1966  *
1967  * Also sets the context as auditable.
1968  */
1969 int auditsc_get_stamp(struct audit_context *ctx,
1970 		       struct timespec64 *t, unsigned int *serial)
1971 {
1972 	if (!ctx->in_syscall)
1973 		return 0;
1974 	if (!ctx->serial)
1975 		ctx->serial = audit_serial();
1976 	t->tv_sec  = ctx->ctime.tv_sec;
1977 	t->tv_nsec = ctx->ctime.tv_nsec;
1978 	*serial    = ctx->serial;
1979 	if (!ctx->prio) {
1980 		ctx->prio = 1;
1981 		ctx->current_state = AUDIT_RECORD_CONTEXT;
1982 	}
1983 	return 1;
1984 }
1985 
1986 /* global counter which is incremented every time something logs in */
1987 static atomic_t session_id = ATOMIC_INIT(0);
1988 
1989 static int audit_set_loginuid_perm(kuid_t loginuid)
1990 {
1991 	/* if we are unset, we don't need privs */
1992 	if (!audit_loginuid_set(current))
1993 		return 0;
1994 	/* if AUDIT_FEATURE_LOGINUID_IMMUTABLE means never ever allow a change*/
1995 	if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
1996 		return -EPERM;
1997 	/* it is set, you need permission */
1998 	if (!capable(CAP_AUDIT_CONTROL))
1999 		return -EPERM;
2000 	/* reject if this is not an unset and we don't allow that */
2001 	if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID) && uid_valid(loginuid))
2002 		return -EPERM;
2003 	return 0;
2004 }
2005 
2006 static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
2007 				   unsigned int oldsessionid, unsigned int sessionid,
2008 				   int rc)
2009 {
2010 	struct audit_buffer *ab;
2011 	uid_t uid, oldloginuid, loginuid;
2012 	struct tty_struct *tty;
2013 
2014 	if (!audit_enabled)
2015 		return;
2016 
2017 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
2018 	if (!ab)
2019 		return;
2020 
2021 	uid = from_kuid(&init_user_ns, task_uid(current));
2022 	oldloginuid = from_kuid(&init_user_ns, koldloginuid);
2023 	loginuid = from_kuid(&init_user_ns, kloginuid),
2024 	tty = audit_get_tty();
2025 
2026 	audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
2027 	audit_log_task_context(ab);
2028 	audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
2029 			 oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
2030 			 oldsessionid, sessionid, !rc);
2031 	audit_put_tty(tty);
2032 	audit_log_end(ab);
2033 }
2034 
2035 /**
2036  * audit_set_loginuid - set current task's audit_context loginuid
2037  * @loginuid: loginuid value
2038  *
2039  * Returns 0.
2040  *
2041  * Called (set) from fs/proc/base.c::proc_loginuid_write().
2042  */
2043 int audit_set_loginuid(kuid_t loginuid)
2044 {
2045 	unsigned int oldsessionid, sessionid = AUDIT_SID_UNSET;
2046 	kuid_t oldloginuid;
2047 	int rc;
2048 
2049 	oldloginuid = audit_get_loginuid(current);
2050 	oldsessionid = audit_get_sessionid(current);
2051 
2052 	rc = audit_set_loginuid_perm(loginuid);
2053 	if (rc)
2054 		goto out;
2055 
2056 	/* are we setting or clearing? */
2057 	if (uid_valid(loginuid)) {
2058 		sessionid = (unsigned int)atomic_inc_return(&session_id);
2059 		if (unlikely(sessionid == AUDIT_SID_UNSET))
2060 			sessionid = (unsigned int)atomic_inc_return(&session_id);
2061 	}
2062 
2063 	current->sessionid = sessionid;
2064 	current->loginuid = loginuid;
2065 out:
2066 	audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
2067 	return rc;
2068 }
2069 
2070 /**
2071  * __audit_mq_open - record audit data for a POSIX MQ open
2072  * @oflag: open flag
2073  * @mode: mode bits
2074  * @attr: queue attributes
2075  *
2076  */
2077 void __audit_mq_open(int oflag, umode_t mode, struct mq_attr *attr)
2078 {
2079 	struct audit_context *context = audit_context();
2080 
2081 	if (attr)
2082 		memcpy(&context->mq_open.attr, attr, sizeof(struct mq_attr));
2083 	else
2084 		memset(&context->mq_open.attr, 0, sizeof(struct mq_attr));
2085 
2086 	context->mq_open.oflag = oflag;
2087 	context->mq_open.mode = mode;
2088 
2089 	context->type = AUDIT_MQ_OPEN;
2090 }
2091 
2092 /**
2093  * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive
2094  * @mqdes: MQ descriptor
2095  * @msg_len: Message length
2096  * @msg_prio: Message priority
2097  * @abs_timeout: Message timeout in absolute time
2098  *
2099  */
2100 void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
2101 			const struct timespec64 *abs_timeout)
2102 {
2103 	struct audit_context *context = audit_context();
2104 	struct timespec64 *p = &context->mq_sendrecv.abs_timeout;
2105 
2106 	if (abs_timeout)
2107 		memcpy(p, abs_timeout, sizeof(*p));
2108 	else
2109 		memset(p, 0, sizeof(*p));
2110 
2111 	context->mq_sendrecv.mqdes = mqdes;
2112 	context->mq_sendrecv.msg_len = msg_len;
2113 	context->mq_sendrecv.msg_prio = msg_prio;
2114 
2115 	context->type = AUDIT_MQ_SENDRECV;
2116 }
2117 
2118 /**
2119  * __audit_mq_notify - record audit data for a POSIX MQ notify
2120  * @mqdes: MQ descriptor
2121  * @notification: Notification event
2122  *
2123  */
2124 
2125 void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
2126 {
2127 	struct audit_context *context = audit_context();
2128 
2129 	if (notification)
2130 		context->mq_notify.sigev_signo = notification->sigev_signo;
2131 	else
2132 		context->mq_notify.sigev_signo = 0;
2133 
2134 	context->mq_notify.mqdes = mqdes;
2135 	context->type = AUDIT_MQ_NOTIFY;
2136 }
2137 
2138 /**
2139  * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
2140  * @mqdes: MQ descriptor
2141  * @mqstat: MQ flags
2142  *
2143  */
2144 void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
2145 {
2146 	struct audit_context *context = audit_context();
2147 	context->mq_getsetattr.mqdes = mqdes;
2148 	context->mq_getsetattr.mqstat = *mqstat;
2149 	context->type = AUDIT_MQ_GETSETATTR;
2150 }
2151 
2152 /**
2153  * __audit_ipc_obj - record audit data for ipc object
2154  * @ipcp: ipc permissions
2155  *
2156  */
2157 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
2158 {
2159 	struct audit_context *context = audit_context();
2160 	context->ipc.uid = ipcp->uid;
2161 	context->ipc.gid = ipcp->gid;
2162 	context->ipc.mode = ipcp->mode;
2163 	context->ipc.has_perm = 0;
2164 	security_ipc_getsecid(ipcp, &context->ipc.osid);
2165 	context->type = AUDIT_IPC;
2166 }
2167 
2168 /**
2169  * __audit_ipc_set_perm - record audit data for new ipc permissions
2170  * @qbytes: msgq bytes
2171  * @uid: msgq user id
2172  * @gid: msgq group id
2173  * @mode: msgq mode (permissions)
2174  *
2175  * Called only after audit_ipc_obj().
2176  */
2177 void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode)
2178 {
2179 	struct audit_context *context = audit_context();
2180 
2181 	context->ipc.qbytes = qbytes;
2182 	context->ipc.perm_uid = uid;
2183 	context->ipc.perm_gid = gid;
2184 	context->ipc.perm_mode = mode;
2185 	context->ipc.has_perm = 1;
2186 }
2187 
2188 void __audit_bprm(struct linux_binprm *bprm)
2189 {
2190 	struct audit_context *context = audit_context();
2191 
2192 	context->type = AUDIT_EXECVE;
2193 	context->execve.argc = bprm->argc;
2194 }
2195 
2196 
2197 /**
2198  * __audit_socketcall - record audit data for sys_socketcall
2199  * @nargs: number of args, which should not be more than AUDITSC_ARGS.
2200  * @args: args array
2201  *
2202  */
2203 int __audit_socketcall(int nargs, unsigned long *args)
2204 {
2205 	struct audit_context *context = audit_context();
2206 
2207 	if (nargs <= 0 || nargs > AUDITSC_ARGS || !args)
2208 		return -EINVAL;
2209 	context->type = AUDIT_SOCKETCALL;
2210 	context->socketcall.nargs = nargs;
2211 	memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long));
2212 	return 0;
2213 }
2214 
2215 /**
2216  * __audit_fd_pair - record audit data for pipe and socketpair
2217  * @fd1: the first file descriptor
2218  * @fd2: the second file descriptor
2219  *
2220  */
2221 void __audit_fd_pair(int fd1, int fd2)
2222 {
2223 	struct audit_context *context = audit_context();
2224 	context->fds[0] = fd1;
2225 	context->fds[1] = fd2;
2226 }
2227 
2228 /**
2229  * __audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
2230  * @len: data length in user space
2231  * @a: data address in kernel space
2232  *
2233  * Returns 0 for success or NULL context or < 0 on error.
2234  */
2235 int __audit_sockaddr(int len, void *a)
2236 {
2237 	struct audit_context *context = audit_context();
2238 
2239 	if (!context->sockaddr) {
2240 		void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL);
2241 		if (!p)
2242 			return -ENOMEM;
2243 		context->sockaddr = p;
2244 	}
2245 
2246 	context->sockaddr_len = len;
2247 	memcpy(context->sockaddr, a, len);
2248 	return 0;
2249 }
2250 
2251 void __audit_ptrace(struct task_struct *t)
2252 {
2253 	struct audit_context *context = audit_context();
2254 
2255 	context->target_pid = task_tgid_nr(t);
2256 	context->target_auid = audit_get_loginuid(t);
2257 	context->target_uid = task_uid(t);
2258 	context->target_sessionid = audit_get_sessionid(t);
2259 	security_task_getsecid(t, &context->target_sid);
2260 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
2261 }
2262 
2263 /**
2264  * audit_signal_info - record signal info for shutting down audit subsystem
2265  * @sig: signal value
2266  * @t: task being signaled
2267  *
2268  * If the audit subsystem is being terminated, record the task (pid)
2269  * and uid that is doing that.
2270  */
2271 int audit_signal_info(int sig, struct task_struct *t)
2272 {
2273 	struct audit_aux_data_pids *axp;
2274 	struct audit_context *ctx = audit_context();
2275 	kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
2276 
2277 	if (auditd_test_task(t) &&
2278 	    (sig == SIGTERM || sig == SIGHUP ||
2279 	     sig == SIGUSR1 || sig == SIGUSR2)) {
2280 		audit_sig_pid = task_tgid_nr(current);
2281 		auid = audit_get_loginuid(current);
2282 		if (uid_valid(auid))
2283 			audit_sig_uid = auid;
2284 		else
2285 			audit_sig_uid = uid;
2286 		security_task_getsecid(current, &audit_sig_sid);
2287 	}
2288 
2289 	if (!audit_signals || audit_dummy_context())
2290 		return 0;
2291 
2292 	/* optimize the common case by putting first signal recipient directly
2293 	 * in audit_context */
2294 	if (!ctx->target_pid) {
2295 		ctx->target_pid = task_tgid_nr(t);
2296 		ctx->target_auid = audit_get_loginuid(t);
2297 		ctx->target_uid = t_uid;
2298 		ctx->target_sessionid = audit_get_sessionid(t);
2299 		security_task_getsecid(t, &ctx->target_sid);
2300 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
2301 		return 0;
2302 	}
2303 
2304 	axp = (void *)ctx->aux_pids;
2305 	if (!axp || axp->pid_count == AUDIT_AUX_PIDS) {
2306 		axp = kzalloc(sizeof(*axp), GFP_ATOMIC);
2307 		if (!axp)
2308 			return -ENOMEM;
2309 
2310 		axp->d.type = AUDIT_OBJ_PID;
2311 		axp->d.next = ctx->aux_pids;
2312 		ctx->aux_pids = (void *)axp;
2313 	}
2314 	BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);
2315 
2316 	axp->target_pid[axp->pid_count] = task_tgid_nr(t);
2317 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
2318 	axp->target_uid[axp->pid_count] = t_uid;
2319 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
2320 	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
2321 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
2322 	axp->pid_count++;
2323 
2324 	return 0;
2325 }
2326 
2327 /**
2328  * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps
2329  * @bprm: pointer to the bprm being processed
2330  * @new: the proposed new credentials
2331  * @old: the old credentials
2332  *
2333  * Simply check if the proc already has the caps given by the file and if not
2334  * store the priv escalation info for later auditing at the end of the syscall
2335  *
2336  * -Eric
2337  */
2338 int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
2339 			   const struct cred *new, const struct cred *old)
2340 {
2341 	struct audit_aux_data_bprm_fcaps *ax;
2342 	struct audit_context *context = audit_context();
2343 	struct cpu_vfs_cap_data vcaps;
2344 
2345 	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2346 	if (!ax)
2347 		return -ENOMEM;
2348 
2349 	ax->d.type = AUDIT_BPRM_FCAPS;
2350 	ax->d.next = context->aux;
2351 	context->aux = (void *)ax;
2352 
2353 	get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps);
2354 
2355 	ax->fcap.permitted = vcaps.permitted;
2356 	ax->fcap.inheritable = vcaps.inheritable;
2357 	ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2358 	ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
2359 
2360 	ax->old_pcap.permitted   = old->cap_permitted;
2361 	ax->old_pcap.inheritable = old->cap_inheritable;
2362 	ax->old_pcap.effective   = old->cap_effective;
2363 	ax->old_pcap.ambient     = old->cap_ambient;
2364 
2365 	ax->new_pcap.permitted   = new->cap_permitted;
2366 	ax->new_pcap.inheritable = new->cap_inheritable;
2367 	ax->new_pcap.effective   = new->cap_effective;
2368 	ax->new_pcap.ambient     = new->cap_ambient;
2369 	return 0;
2370 }
2371 
2372 /**
2373  * __audit_log_capset - store information about the arguments to the capset syscall
2374  * @new: the new credentials
2375  * @old: the old (current) credentials
2376  *
2377  * Record the arguments userspace sent to sys_capset for later printing by the
2378  * audit system if applicable
2379  */
2380 void __audit_log_capset(const struct cred *new, const struct cred *old)
2381 {
2382 	struct audit_context *context = audit_context();
2383 	context->capset.pid = task_tgid_nr(current);
2384 	context->capset.cap.effective   = new->cap_effective;
2385 	context->capset.cap.inheritable = new->cap_effective;
2386 	context->capset.cap.permitted   = new->cap_permitted;
2387 	context->capset.cap.ambient     = new->cap_ambient;
2388 	context->type = AUDIT_CAPSET;
2389 }
2390 
2391 void __audit_mmap_fd(int fd, int flags)
2392 {
2393 	struct audit_context *context = audit_context();
2394 	context->mmap.fd = fd;
2395 	context->mmap.flags = flags;
2396 	context->type = AUDIT_MMAP;
2397 }
2398 
2399 void __audit_log_kern_module(char *name)
2400 {
2401 	struct audit_context *context = audit_context();
2402 
2403 	context->module.name = kstrdup(name, GFP_KERNEL);
2404 	if (!context->module.name)
2405 		audit_log_lost("out of memory in __audit_log_kern_module");
2406 	context->type = AUDIT_KERN_MODULE;
2407 }
2408 
2409 void __audit_fanotify(unsigned int response)
2410 {
2411 	audit_log(audit_context(), GFP_KERNEL,
2412 		AUDIT_FANOTIFY,	"resp=%u", response);
2413 }
2414 
2415 static void audit_log_task(struct audit_buffer *ab)
2416 {
2417 	kuid_t auid, uid;
2418 	kgid_t gid;
2419 	unsigned int sessionid;
2420 	char comm[sizeof(current->comm)];
2421 
2422 	auid = audit_get_loginuid(current);
2423 	sessionid = audit_get_sessionid(current);
2424 	current_uid_gid(&uid, &gid);
2425 
2426 	audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
2427 			 from_kuid(&init_user_ns, auid),
2428 			 from_kuid(&init_user_ns, uid),
2429 			 from_kgid(&init_user_ns, gid),
2430 			 sessionid);
2431 	audit_log_task_context(ab);
2432 	audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
2433 	audit_log_untrustedstring(ab, get_task_comm(comm, current));
2434 	audit_log_d_path_exe(ab, current->mm);
2435 }
2436 
2437 /**
2438  * audit_core_dumps - record information about processes that end abnormally
2439  * @signr: signal value
2440  *
2441  * If a process ends with a core dump, something fishy is going on and we
2442  * should record the event for investigation.
2443  */
2444 void audit_core_dumps(long signr)
2445 {
2446 	struct audit_buffer *ab;
2447 
2448 	if (!audit_enabled)
2449 		return;
2450 
2451 	if (signr == SIGQUIT)	/* don't care for those */
2452 		return;
2453 
2454 	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_ABEND);
2455 	if (unlikely(!ab))
2456 		return;
2457 	audit_log_task(ab);
2458 	audit_log_format(ab, " sig=%ld res=1", signr);
2459 	audit_log_end(ab);
2460 }
2461 
2462 /**
2463  * audit_seccomp - record information about a seccomp action
2464  * @syscall: syscall number
2465  * @signr: signal value
2466  * @code: the seccomp action
2467  *
2468  * Record the information associated with a seccomp action. Event filtering for
2469  * seccomp actions that are not to be logged is done in seccomp_log().
2470  * Therefore, this function forces auditing independent of the audit_enabled
2471  * and dummy context state because seccomp actions should be logged even when
2472  * audit is not in use.
2473  */
2474 void audit_seccomp(unsigned long syscall, long signr, int code)
2475 {
2476 	struct audit_buffer *ab;
2477 
2478 	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_SECCOMP);
2479 	if (unlikely(!ab))
2480 		return;
2481 	audit_log_task(ab);
2482 	audit_log_format(ab, " sig=%ld arch=%x syscall=%ld compat=%d ip=0x%lx code=0x%x",
2483 			 signr, syscall_get_arch(), syscall,
2484 			 in_compat_syscall(), KSTK_EIP(current), code);
2485 	audit_log_end(ab);
2486 }
2487 
2488 void audit_seccomp_actions_logged(const char *names, const char *old_names,
2489 				  int res)
2490 {
2491 	struct audit_buffer *ab;
2492 
2493 	if (!audit_enabled)
2494 		return;
2495 
2496 	ab = audit_log_start(audit_context(), GFP_KERNEL,
2497 			     AUDIT_CONFIG_CHANGE);
2498 	if (unlikely(!ab))
2499 		return;
2500 
2501 	audit_log_format(ab,
2502 			 "op=seccomp-logging actions=%s old-actions=%s res=%d",
2503 			 names, old_names, res);
2504 	audit_log_end(ab);
2505 }
2506 
2507 struct list_head *audit_killed_trees(void)
2508 {
2509 	struct audit_context *ctx = audit_context();
2510 	if (likely(!ctx || !ctx->in_syscall))
2511 		return NULL;
2512 	return &ctx->killed_trees;
2513 }
2514