xref: /openbmc/linux/kernel/auditsc.c (revision 239480ab)
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 #ifdef CONFIG_AUDIT_TREE
204 static void audit_set_auditable(struct audit_context *ctx)
205 {
206 	if (!ctx->prio) {
207 		ctx->prio = 1;
208 		ctx->current_state = AUDIT_RECORD_CONTEXT;
209 	}
210 }
211 
212 static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
213 {
214 	struct audit_tree_refs *p = ctx->trees;
215 	int left = ctx->tree_count;
216 	if (likely(left)) {
217 		p->c[--left] = chunk;
218 		ctx->tree_count = left;
219 		return 1;
220 	}
221 	if (!p)
222 		return 0;
223 	p = p->next;
224 	if (p) {
225 		p->c[30] = chunk;
226 		ctx->trees = p;
227 		ctx->tree_count = 30;
228 		return 1;
229 	}
230 	return 0;
231 }
232 
233 static int grow_tree_refs(struct audit_context *ctx)
234 {
235 	struct audit_tree_refs *p = ctx->trees;
236 	ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
237 	if (!ctx->trees) {
238 		ctx->trees = p;
239 		return 0;
240 	}
241 	if (p)
242 		p->next = ctx->trees;
243 	else
244 		ctx->first_trees = ctx->trees;
245 	ctx->tree_count = 31;
246 	return 1;
247 }
248 #endif
249 
250 static void unroll_tree_refs(struct audit_context *ctx,
251 		      struct audit_tree_refs *p, int count)
252 {
253 #ifdef CONFIG_AUDIT_TREE
254 	struct audit_tree_refs *q;
255 	int n;
256 	if (!p) {
257 		/* we started with empty chain */
258 		p = ctx->first_trees;
259 		count = 31;
260 		/* if the very first allocation has failed, nothing to do */
261 		if (!p)
262 			return;
263 	}
264 	n = count;
265 	for (q = p; q != ctx->trees; q = q->next, n = 31) {
266 		while (n--) {
267 			audit_put_chunk(q->c[n]);
268 			q->c[n] = NULL;
269 		}
270 	}
271 	while (n-- > ctx->tree_count) {
272 		audit_put_chunk(q->c[n]);
273 		q->c[n] = NULL;
274 	}
275 	ctx->trees = p;
276 	ctx->tree_count = count;
277 #endif
278 }
279 
280 static void free_tree_refs(struct audit_context *ctx)
281 {
282 	struct audit_tree_refs *p, *q;
283 	for (p = ctx->first_trees; p; p = q) {
284 		q = p->next;
285 		kfree(p);
286 	}
287 }
288 
289 static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
290 {
291 #ifdef CONFIG_AUDIT_TREE
292 	struct audit_tree_refs *p;
293 	int n;
294 	if (!tree)
295 		return 0;
296 	/* full ones */
297 	for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
298 		for (n = 0; n < 31; n++)
299 			if (audit_tree_match(p->c[n], tree))
300 				return 1;
301 	}
302 	/* partial */
303 	if (p) {
304 		for (n = ctx->tree_count; n < 31; n++)
305 			if (audit_tree_match(p->c[n], tree))
306 				return 1;
307 	}
308 #endif
309 	return 0;
310 }
311 
312 static int audit_compare_uid(kuid_t uid,
313 			     struct audit_names *name,
314 			     struct audit_field *f,
315 			     struct audit_context *ctx)
316 {
317 	struct audit_names *n;
318 	int rc;
319 
320 	if (name) {
321 		rc = audit_uid_comparator(uid, f->op, name->uid);
322 		if (rc)
323 			return rc;
324 	}
325 
326 	if (ctx) {
327 		list_for_each_entry(n, &ctx->names_list, list) {
328 			rc = audit_uid_comparator(uid, f->op, n->uid);
329 			if (rc)
330 				return rc;
331 		}
332 	}
333 	return 0;
334 }
335 
336 static int audit_compare_gid(kgid_t gid,
337 			     struct audit_names *name,
338 			     struct audit_field *f,
339 			     struct audit_context *ctx)
340 {
341 	struct audit_names *n;
342 	int rc;
343 
344 	if (name) {
345 		rc = audit_gid_comparator(gid, f->op, name->gid);
346 		if (rc)
347 			return rc;
348 	}
349 
350 	if (ctx) {
351 		list_for_each_entry(n, &ctx->names_list, list) {
352 			rc = audit_gid_comparator(gid, f->op, n->gid);
353 			if (rc)
354 				return rc;
355 		}
356 	}
357 	return 0;
358 }
359 
360 static int audit_field_compare(struct task_struct *tsk,
361 			       const struct cred *cred,
362 			       struct audit_field *f,
363 			       struct audit_context *ctx,
364 			       struct audit_names *name)
365 {
366 	switch (f->val) {
367 	/* process to file object comparisons */
368 	case AUDIT_COMPARE_UID_TO_OBJ_UID:
369 		return audit_compare_uid(cred->uid, name, f, ctx);
370 	case AUDIT_COMPARE_GID_TO_OBJ_GID:
371 		return audit_compare_gid(cred->gid, name, f, ctx);
372 	case AUDIT_COMPARE_EUID_TO_OBJ_UID:
373 		return audit_compare_uid(cred->euid, name, f, ctx);
374 	case AUDIT_COMPARE_EGID_TO_OBJ_GID:
375 		return audit_compare_gid(cred->egid, name, f, ctx);
376 	case AUDIT_COMPARE_AUID_TO_OBJ_UID:
377 		return audit_compare_uid(tsk->loginuid, name, f, ctx);
378 	case AUDIT_COMPARE_SUID_TO_OBJ_UID:
379 		return audit_compare_uid(cred->suid, name, f, ctx);
380 	case AUDIT_COMPARE_SGID_TO_OBJ_GID:
381 		return audit_compare_gid(cred->sgid, name, f, ctx);
382 	case AUDIT_COMPARE_FSUID_TO_OBJ_UID:
383 		return audit_compare_uid(cred->fsuid, name, f, ctx);
384 	case AUDIT_COMPARE_FSGID_TO_OBJ_GID:
385 		return audit_compare_gid(cred->fsgid, name, f, ctx);
386 	/* uid comparisons */
387 	case AUDIT_COMPARE_UID_TO_AUID:
388 		return audit_uid_comparator(cred->uid, f->op, tsk->loginuid);
389 	case AUDIT_COMPARE_UID_TO_EUID:
390 		return audit_uid_comparator(cred->uid, f->op, cred->euid);
391 	case AUDIT_COMPARE_UID_TO_SUID:
392 		return audit_uid_comparator(cred->uid, f->op, cred->suid);
393 	case AUDIT_COMPARE_UID_TO_FSUID:
394 		return audit_uid_comparator(cred->uid, f->op, cred->fsuid);
395 	/* auid comparisons */
396 	case AUDIT_COMPARE_AUID_TO_EUID:
397 		return audit_uid_comparator(tsk->loginuid, f->op, cred->euid);
398 	case AUDIT_COMPARE_AUID_TO_SUID:
399 		return audit_uid_comparator(tsk->loginuid, f->op, cred->suid);
400 	case AUDIT_COMPARE_AUID_TO_FSUID:
401 		return audit_uid_comparator(tsk->loginuid, f->op, cred->fsuid);
402 	/* euid comparisons */
403 	case AUDIT_COMPARE_EUID_TO_SUID:
404 		return audit_uid_comparator(cred->euid, f->op, cred->suid);
405 	case AUDIT_COMPARE_EUID_TO_FSUID:
406 		return audit_uid_comparator(cred->euid, f->op, cred->fsuid);
407 	/* suid comparisons */
408 	case AUDIT_COMPARE_SUID_TO_FSUID:
409 		return audit_uid_comparator(cred->suid, f->op, cred->fsuid);
410 	/* gid comparisons */
411 	case AUDIT_COMPARE_GID_TO_EGID:
412 		return audit_gid_comparator(cred->gid, f->op, cred->egid);
413 	case AUDIT_COMPARE_GID_TO_SGID:
414 		return audit_gid_comparator(cred->gid, f->op, cred->sgid);
415 	case AUDIT_COMPARE_GID_TO_FSGID:
416 		return audit_gid_comparator(cred->gid, f->op, cred->fsgid);
417 	/* egid comparisons */
418 	case AUDIT_COMPARE_EGID_TO_SGID:
419 		return audit_gid_comparator(cred->egid, f->op, cred->sgid);
420 	case AUDIT_COMPARE_EGID_TO_FSGID:
421 		return audit_gid_comparator(cred->egid, f->op, cred->fsgid);
422 	/* sgid comparison */
423 	case AUDIT_COMPARE_SGID_TO_FSGID:
424 		return audit_gid_comparator(cred->sgid, f->op, cred->fsgid);
425 	default:
426 		WARN(1, "Missing AUDIT_COMPARE define.  Report as a bug\n");
427 		return 0;
428 	}
429 	return 0;
430 }
431 
432 /* Determine if any context name data matches a rule's watch data */
433 /* Compare a task_struct with an audit_rule.  Return 1 on match, 0
434  * otherwise.
435  *
436  * If task_creation is true, this is an explicit indication that we are
437  * filtering a task rule at task creation time.  This and tsk == current are
438  * the only situations where tsk->cred may be accessed without an rcu read lock.
439  */
440 static int audit_filter_rules(struct task_struct *tsk,
441 			      struct audit_krule *rule,
442 			      struct audit_context *ctx,
443 			      struct audit_names *name,
444 			      enum audit_state *state,
445 			      bool task_creation)
446 {
447 	const struct cred *cred;
448 	int i, need_sid = 1;
449 	u32 sid;
450 	unsigned int sessionid;
451 
452 	cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
453 
454 	for (i = 0; i < rule->field_count; i++) {
455 		struct audit_field *f = &rule->fields[i];
456 		struct audit_names *n;
457 		int result = 0;
458 		pid_t pid;
459 
460 		switch (f->type) {
461 		case AUDIT_PID:
462 			pid = task_tgid_nr(tsk);
463 			result = audit_comparator(pid, f->op, f->val);
464 			break;
465 		case AUDIT_PPID:
466 			if (ctx) {
467 				if (!ctx->ppid)
468 					ctx->ppid = task_ppid_nr(tsk);
469 				result = audit_comparator(ctx->ppid, f->op, f->val);
470 			}
471 			break;
472 		case AUDIT_EXE:
473 			result = audit_exe_compare(tsk, rule->exe);
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 = in_group_p(f->gid);
492 			} else if (f->op == Audit_not_equal) {
493 				if (result)
494 					result = !in_group_p(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 = in_egroup_p(f->gid);
502 			} else if (f->op == Audit_not_equal) {
503 				if (result)
504 					result = !in_egroup_p(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(current);
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(tsk->loginuid, f->op, f->uid);
613 			break;
614 		case AUDIT_LOGINUID_SET:
615 			result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
616 			break;
617 		case AUDIT_SUBJ_USER:
618 		case AUDIT_SUBJ_ROLE:
619 		case AUDIT_SUBJ_TYPE:
620 		case AUDIT_SUBJ_SEN:
621 		case AUDIT_SUBJ_CLR:
622 			/* NOTE: this may return negative values indicating
623 			   a temporary error.  We simply treat this as a
624 			   match for now to avoid losing information that
625 			   may be wanted.   An error message will also be
626 			   logged upon error */
627 			if (f->lsm_rule) {
628 				if (need_sid) {
629 					security_task_getsecid(tsk, &sid);
630 					need_sid = 0;
631 				}
632 				result = security_audit_rule_match(sid, f->type,
633 				                                  f->op,
634 				                                  f->lsm_rule,
635 				                                  ctx);
636 			}
637 			break;
638 		case AUDIT_OBJ_USER:
639 		case AUDIT_OBJ_ROLE:
640 		case AUDIT_OBJ_TYPE:
641 		case AUDIT_OBJ_LEV_LOW:
642 		case AUDIT_OBJ_LEV_HIGH:
643 			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
644 			   also applies here */
645 			if (f->lsm_rule) {
646 				/* Find files that match */
647 				if (name) {
648 					result = security_audit_rule_match(
649 					           name->osid, f->type, f->op,
650 					           f->lsm_rule, ctx);
651 				} else if (ctx) {
652 					list_for_each_entry(n, &ctx->names_list, list) {
653 						if (security_audit_rule_match(n->osid, f->type,
654 									      f->op, f->lsm_rule,
655 									      ctx)) {
656 							++result;
657 							break;
658 						}
659 					}
660 				}
661 				/* Find ipc objects that match */
662 				if (!ctx || ctx->type != AUDIT_IPC)
663 					break;
664 				if (security_audit_rule_match(ctx->ipc.osid,
665 							      f->type, f->op,
666 							      f->lsm_rule, ctx))
667 					++result;
668 			}
669 			break;
670 		case AUDIT_ARG0:
671 		case AUDIT_ARG1:
672 		case AUDIT_ARG2:
673 		case AUDIT_ARG3:
674 			if (ctx)
675 				result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
676 			break;
677 		case AUDIT_FILTERKEY:
678 			/* ignore this field for filtering */
679 			result = 1;
680 			break;
681 		case AUDIT_PERM:
682 			result = audit_match_perm(ctx, f->val);
683 			break;
684 		case AUDIT_FILETYPE:
685 			result = audit_match_filetype(ctx, f->val);
686 			break;
687 		case AUDIT_FIELD_COMPARE:
688 			result = audit_field_compare(tsk, cred, f, ctx, name);
689 			break;
690 		}
691 		if (!result)
692 			return 0;
693 	}
694 
695 	if (ctx) {
696 		if (rule->prio <= ctx->prio)
697 			return 0;
698 		if (rule->filterkey) {
699 			kfree(ctx->filterkey);
700 			ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
701 		}
702 		ctx->prio = rule->prio;
703 	}
704 	switch (rule->action) {
705 	case AUDIT_NEVER:
706 		*state = AUDIT_DISABLED;
707 		break;
708 	case AUDIT_ALWAYS:
709 		*state = AUDIT_RECORD_CONTEXT;
710 		break;
711 	}
712 	return 1;
713 }
714 
715 /* At process creation time, we can determine if system-call auditing is
716  * completely disabled for this task.  Since we only have the task
717  * structure at this point, we can only check uid and gid.
718  */
719 static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
720 {
721 	struct audit_entry *e;
722 	enum audit_state   state;
723 
724 	rcu_read_lock();
725 	list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
726 		if (audit_filter_rules(tsk, &e->rule, NULL, NULL,
727 				       &state, true)) {
728 			if (state == AUDIT_RECORD_CONTEXT)
729 				*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
730 			rcu_read_unlock();
731 			return state;
732 		}
733 	}
734 	rcu_read_unlock();
735 	return AUDIT_BUILD_CONTEXT;
736 }
737 
738 static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
739 {
740 	int word, bit;
741 
742 	if (val > 0xffffffff)
743 		return false;
744 
745 	word = AUDIT_WORD(val);
746 	if (word >= AUDIT_BITMASK_SIZE)
747 		return false;
748 
749 	bit = AUDIT_BIT(val);
750 
751 	return rule->mask[word] & bit;
752 }
753 
754 /* At syscall entry and exit time, this filter is called if the
755  * audit_state is not low enough that auditing cannot take place, but is
756  * also not high enough that we already know we have to write an audit
757  * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
758  */
759 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
760 					     struct audit_context *ctx,
761 					     struct list_head *list)
762 {
763 	struct audit_entry *e;
764 	enum audit_state state;
765 
766 	if (auditd_test_task(tsk))
767 		return AUDIT_DISABLED;
768 
769 	rcu_read_lock();
770 	if (!list_empty(list)) {
771 		list_for_each_entry_rcu(e, list, list) {
772 			if (audit_in_mask(&e->rule, ctx->major) &&
773 			    audit_filter_rules(tsk, &e->rule, ctx, NULL,
774 					       &state, false)) {
775 				rcu_read_unlock();
776 				ctx->current_state = state;
777 				return state;
778 			}
779 		}
780 	}
781 	rcu_read_unlock();
782 	return AUDIT_BUILD_CONTEXT;
783 }
784 
785 /*
786  * Given an audit_name check the inode hash table to see if they match.
787  * Called holding the rcu read lock to protect the use of audit_inode_hash
788  */
789 static int audit_filter_inode_name(struct task_struct *tsk,
790 				   struct audit_names *n,
791 				   struct audit_context *ctx) {
792 	int h = audit_hash_ino((u32)n->ino);
793 	struct list_head *list = &audit_inode_hash[h];
794 	struct audit_entry *e;
795 	enum audit_state state;
796 
797 	if (list_empty(list))
798 		return 0;
799 
800 	list_for_each_entry_rcu(e, list, list) {
801 		if (audit_in_mask(&e->rule, ctx->major) &&
802 		    audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {
803 			ctx->current_state = state;
804 			return 1;
805 		}
806 	}
807 
808 	return 0;
809 }
810 
811 /* At syscall exit time, this filter is called if any audit_names have been
812  * collected during syscall processing.  We only check rules in sublists at hash
813  * buckets applicable to the inode numbers in audit_names.
814  * Regarding audit_state, same rules apply as for audit_filter_syscall().
815  */
816 void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
817 {
818 	struct audit_names *n;
819 
820 	if (auditd_test_task(tsk))
821 		return;
822 
823 	rcu_read_lock();
824 
825 	list_for_each_entry(n, &ctx->names_list, list) {
826 		if (audit_filter_inode_name(tsk, n, ctx))
827 			break;
828 	}
829 	rcu_read_unlock();
830 }
831 
832 /* Transfer the audit context pointer to the caller, clearing it in the tsk's struct */
833 static inline struct audit_context *audit_take_context(struct task_struct *tsk,
834 						      int return_valid,
835 						      long return_code)
836 {
837 	struct audit_context *context = tsk->audit_context;
838 
839 	if (!context)
840 		return NULL;
841 	context->return_valid = return_valid;
842 
843 	/*
844 	 * we need to fix up the return code in the audit logs if the actual
845 	 * return codes are later going to be fixed up by the arch specific
846 	 * signal handlers
847 	 *
848 	 * This is actually a test for:
849 	 * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) ||
850 	 * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK)
851 	 *
852 	 * but is faster than a bunch of ||
853 	 */
854 	if (unlikely(return_code <= -ERESTARTSYS) &&
855 	    (return_code >= -ERESTART_RESTARTBLOCK) &&
856 	    (return_code != -ENOIOCTLCMD))
857 		context->return_code = -EINTR;
858 	else
859 		context->return_code  = return_code;
860 
861 	if (context->in_syscall && !context->dummy) {
862 		audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
863 		audit_filter_inodes(tsk, context);
864 	}
865 
866 	tsk->audit_context = NULL;
867 	return context;
868 }
869 
870 static inline void audit_proctitle_free(struct audit_context *context)
871 {
872 	kfree(context->proctitle.value);
873 	context->proctitle.value = NULL;
874 	context->proctitle.len = 0;
875 }
876 
877 static inline void audit_free_names(struct audit_context *context)
878 {
879 	struct audit_names *n, *next;
880 
881 	list_for_each_entry_safe(n, next, &context->names_list, list) {
882 		list_del(&n->list);
883 		if (n->name)
884 			putname(n->name);
885 		if (n->should_free)
886 			kfree(n);
887 	}
888 	context->name_count = 0;
889 	path_put(&context->pwd);
890 	context->pwd.dentry = NULL;
891 	context->pwd.mnt = NULL;
892 }
893 
894 static inline void audit_free_aux(struct audit_context *context)
895 {
896 	struct audit_aux_data *aux;
897 
898 	while ((aux = context->aux)) {
899 		context->aux = aux->next;
900 		kfree(aux);
901 	}
902 	while ((aux = context->aux_pids)) {
903 		context->aux_pids = aux->next;
904 		kfree(aux);
905 	}
906 }
907 
908 static inline struct audit_context *audit_alloc_context(enum audit_state state)
909 {
910 	struct audit_context *context;
911 
912 	context = kzalloc(sizeof(*context), GFP_KERNEL);
913 	if (!context)
914 		return NULL;
915 	context->state = state;
916 	context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
917 	INIT_LIST_HEAD(&context->killed_trees);
918 	INIT_LIST_HEAD(&context->names_list);
919 	return context;
920 }
921 
922 /**
923  * audit_alloc - allocate an audit context block for a task
924  * @tsk: task
925  *
926  * Filter on the task information and allocate a per-task audit context
927  * if necessary.  Doing so turns on system call auditing for the
928  * specified task.  This is called from copy_process, so no lock is
929  * needed.
930  */
931 int audit_alloc(struct task_struct *tsk)
932 {
933 	struct audit_context *context;
934 	enum audit_state     state;
935 	char *key = NULL;
936 
937 	if (likely(!audit_ever_enabled))
938 		return 0; /* Return if not auditing. */
939 
940 	state = audit_filter_task(tsk, &key);
941 	if (state == AUDIT_DISABLED) {
942 		clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
943 		return 0;
944 	}
945 
946 	if (!(context = audit_alloc_context(state))) {
947 		kfree(key);
948 		audit_log_lost("out of memory in audit_alloc");
949 		return -ENOMEM;
950 	}
951 	context->filterkey = key;
952 
953 	tsk->audit_context  = context;
954 	set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
955 	return 0;
956 }
957 
958 static inline void audit_free_context(struct audit_context *context)
959 {
960 	audit_free_names(context);
961 	unroll_tree_refs(context, NULL, 0);
962 	free_tree_refs(context);
963 	audit_free_aux(context);
964 	kfree(context->filterkey);
965 	kfree(context->sockaddr);
966 	audit_proctitle_free(context);
967 	kfree(context);
968 }
969 
970 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
971 				 kuid_t auid, kuid_t uid, unsigned int sessionid,
972 				 u32 sid, char *comm)
973 {
974 	struct audit_buffer *ab;
975 	char *ctx = NULL;
976 	u32 len;
977 	int rc = 0;
978 
979 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
980 	if (!ab)
981 		return rc;
982 
983 	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
984 			 from_kuid(&init_user_ns, auid),
985 			 from_kuid(&init_user_ns, uid), sessionid);
986 	if (sid) {
987 		if (security_secid_to_secctx(sid, &ctx, &len)) {
988 			audit_log_format(ab, " obj=(none)");
989 			rc = 1;
990 		} else {
991 			audit_log_format(ab, " obj=%s", ctx);
992 			security_release_secctx(ctx, len);
993 		}
994 	}
995 	audit_log_format(ab, " ocomm=");
996 	audit_log_untrustedstring(ab, comm);
997 	audit_log_end(ab);
998 
999 	return rc;
1000 }
1001 
1002 static void audit_log_execve_info(struct audit_context *context,
1003 				  struct audit_buffer **ab)
1004 {
1005 	long len_max;
1006 	long len_rem;
1007 	long len_full;
1008 	long len_buf;
1009 	long len_abuf = 0;
1010 	long len_tmp;
1011 	bool require_data;
1012 	bool encode;
1013 	unsigned int iter;
1014 	unsigned int arg;
1015 	char *buf_head;
1016 	char *buf;
1017 	const char __user *p = (const char __user *)current->mm->arg_start;
1018 
1019 	/* NOTE: this buffer needs to be large enough to hold all the non-arg
1020 	 *       data we put in the audit record for this argument (see the
1021 	 *       code below) ... at this point in time 96 is plenty */
1022 	char abuf[96];
1023 
1024 	/* NOTE: we set MAX_EXECVE_AUDIT_LEN to a rather arbitrary limit, the
1025 	 *       current value of 7500 is not as important as the fact that it
1026 	 *       is less than 8k, a setting of 7500 gives us plenty of wiggle
1027 	 *       room if we go over a little bit in the logging below */
1028 	WARN_ON_ONCE(MAX_EXECVE_AUDIT_LEN > 7500);
1029 	len_max = MAX_EXECVE_AUDIT_LEN;
1030 
1031 	/* scratch buffer to hold the userspace args */
1032 	buf_head = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL);
1033 	if (!buf_head) {
1034 		audit_panic("out of memory for argv string");
1035 		return;
1036 	}
1037 	buf = buf_head;
1038 
1039 	audit_log_format(*ab, "argc=%d", context->execve.argc);
1040 
1041 	len_rem = len_max;
1042 	len_buf = 0;
1043 	len_full = 0;
1044 	require_data = true;
1045 	encode = false;
1046 	iter = 0;
1047 	arg = 0;
1048 	do {
1049 		/* NOTE: we don't ever want to trust this value for anything
1050 		 *       serious, but the audit record format insists we
1051 		 *       provide an argument length for really long arguments,
1052 		 *       e.g. > MAX_EXECVE_AUDIT_LEN, so we have no choice but
1053 		 *       to use strncpy_from_user() to obtain this value for
1054 		 *       recording in the log, although we don't use it
1055 		 *       anywhere here to avoid a double-fetch problem */
1056 		if (len_full == 0)
1057 			len_full = strnlen_user(p, MAX_ARG_STRLEN) - 1;
1058 
1059 		/* read more data from userspace */
1060 		if (require_data) {
1061 			/* can we make more room in the buffer? */
1062 			if (buf != buf_head) {
1063 				memmove(buf_head, buf, len_buf);
1064 				buf = buf_head;
1065 			}
1066 
1067 			/* fetch as much as we can of the argument */
1068 			len_tmp = strncpy_from_user(&buf_head[len_buf], p,
1069 						    len_max - len_buf);
1070 			if (len_tmp == -EFAULT) {
1071 				/* unable to copy from userspace */
1072 				send_sig(SIGKILL, current, 0);
1073 				goto out;
1074 			} else if (len_tmp == (len_max - len_buf)) {
1075 				/* buffer is not large enough */
1076 				require_data = true;
1077 				/* NOTE: if we are going to span multiple
1078 				 *       buffers force the encoding so we stand
1079 				 *       a chance at a sane len_full value and
1080 				 *       consistent record encoding */
1081 				encode = true;
1082 				len_full = len_full * 2;
1083 				p += len_tmp;
1084 			} else {
1085 				require_data = false;
1086 				if (!encode)
1087 					encode = audit_string_contains_control(
1088 								buf, len_tmp);
1089 				/* try to use a trusted value for len_full */
1090 				if (len_full < len_max)
1091 					len_full = (encode ?
1092 						    len_tmp * 2 : len_tmp);
1093 				p += len_tmp + 1;
1094 			}
1095 			len_buf += len_tmp;
1096 			buf_head[len_buf] = '\0';
1097 
1098 			/* length of the buffer in the audit record? */
1099 			len_abuf = (encode ? len_buf * 2 : len_buf + 2);
1100 		}
1101 
1102 		/* write as much as we can to the audit log */
1103 		if (len_buf > 0) {
1104 			/* NOTE: some magic numbers here - basically if we
1105 			 *       can't fit a reasonable amount of data into the
1106 			 *       existing audit buffer, flush it and start with
1107 			 *       a new buffer */
1108 			if ((sizeof(abuf) + 8) > len_rem) {
1109 				len_rem = len_max;
1110 				audit_log_end(*ab);
1111 				*ab = audit_log_start(context,
1112 						      GFP_KERNEL, AUDIT_EXECVE);
1113 				if (!*ab)
1114 					goto out;
1115 			}
1116 
1117 			/* create the non-arg portion of the arg record */
1118 			len_tmp = 0;
1119 			if (require_data || (iter > 0) ||
1120 			    ((len_abuf + sizeof(abuf)) > len_rem)) {
1121 				if (iter == 0) {
1122 					len_tmp += snprintf(&abuf[len_tmp],
1123 							sizeof(abuf) - len_tmp,
1124 							" a%d_len=%lu",
1125 							arg, len_full);
1126 				}
1127 				len_tmp += snprintf(&abuf[len_tmp],
1128 						    sizeof(abuf) - len_tmp,
1129 						    " a%d[%d]=", arg, iter++);
1130 			} else
1131 				len_tmp += snprintf(&abuf[len_tmp],
1132 						    sizeof(abuf) - len_tmp,
1133 						    " a%d=", arg);
1134 			WARN_ON(len_tmp >= sizeof(abuf));
1135 			abuf[sizeof(abuf) - 1] = '\0';
1136 
1137 			/* log the arg in the audit record */
1138 			audit_log_format(*ab, "%s", abuf);
1139 			len_rem -= len_tmp;
1140 			len_tmp = len_buf;
1141 			if (encode) {
1142 				if (len_abuf > len_rem)
1143 					len_tmp = len_rem / 2; /* encoding */
1144 				audit_log_n_hex(*ab, buf, len_tmp);
1145 				len_rem -= len_tmp * 2;
1146 				len_abuf -= len_tmp * 2;
1147 			} else {
1148 				if (len_abuf > len_rem)
1149 					len_tmp = len_rem - 2; /* quotes */
1150 				audit_log_n_string(*ab, buf, len_tmp);
1151 				len_rem -= len_tmp + 2;
1152 				/* don't subtract the "2" because we still need
1153 				 * to add quotes to the remaining string */
1154 				len_abuf -= len_tmp;
1155 			}
1156 			len_buf -= len_tmp;
1157 			buf += len_tmp;
1158 		}
1159 
1160 		/* ready to move to the next argument? */
1161 		if ((len_buf == 0) && !require_data) {
1162 			arg++;
1163 			iter = 0;
1164 			len_full = 0;
1165 			require_data = true;
1166 			encode = false;
1167 		}
1168 	} while (arg < context->execve.argc);
1169 
1170 	/* NOTE: the caller handles the final audit_log_end() call */
1171 
1172 out:
1173 	kfree(buf_head);
1174 }
1175 
1176 static void show_special(struct audit_context *context, int *call_panic)
1177 {
1178 	struct audit_buffer *ab;
1179 	int i;
1180 
1181 	ab = audit_log_start(context, GFP_KERNEL, context->type);
1182 	if (!ab)
1183 		return;
1184 
1185 	switch (context->type) {
1186 	case AUDIT_SOCKETCALL: {
1187 		int nargs = context->socketcall.nargs;
1188 		audit_log_format(ab, "nargs=%d", nargs);
1189 		for (i = 0; i < nargs; i++)
1190 			audit_log_format(ab, " a%d=%lx", i,
1191 				context->socketcall.args[i]);
1192 		break; }
1193 	case AUDIT_IPC: {
1194 		u32 osid = context->ipc.osid;
1195 
1196 		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
1197 				 from_kuid(&init_user_ns, context->ipc.uid),
1198 				 from_kgid(&init_user_ns, context->ipc.gid),
1199 				 context->ipc.mode);
1200 		if (osid) {
1201 			char *ctx = NULL;
1202 			u32 len;
1203 			if (security_secid_to_secctx(osid, &ctx, &len)) {
1204 				audit_log_format(ab, " osid=%u", osid);
1205 				*call_panic = 1;
1206 			} else {
1207 				audit_log_format(ab, " obj=%s", ctx);
1208 				security_release_secctx(ctx, len);
1209 			}
1210 		}
1211 		if (context->ipc.has_perm) {
1212 			audit_log_end(ab);
1213 			ab = audit_log_start(context, GFP_KERNEL,
1214 					     AUDIT_IPC_SET_PERM);
1215 			if (unlikely(!ab))
1216 				return;
1217 			audit_log_format(ab,
1218 				"qbytes=%lx ouid=%u ogid=%u mode=%#ho",
1219 				context->ipc.qbytes,
1220 				context->ipc.perm_uid,
1221 				context->ipc.perm_gid,
1222 				context->ipc.perm_mode);
1223 		}
1224 		break; }
1225 	case AUDIT_MQ_OPEN:
1226 		audit_log_format(ab,
1227 			"oflag=0x%x mode=%#ho mq_flags=0x%lx mq_maxmsg=%ld "
1228 			"mq_msgsize=%ld mq_curmsgs=%ld",
1229 			context->mq_open.oflag, context->mq_open.mode,
1230 			context->mq_open.attr.mq_flags,
1231 			context->mq_open.attr.mq_maxmsg,
1232 			context->mq_open.attr.mq_msgsize,
1233 			context->mq_open.attr.mq_curmsgs);
1234 		break;
1235 	case AUDIT_MQ_SENDRECV:
1236 		audit_log_format(ab,
1237 			"mqdes=%d msg_len=%zd msg_prio=%u "
1238 			"abs_timeout_sec=%ld abs_timeout_nsec=%ld",
1239 			context->mq_sendrecv.mqdes,
1240 			context->mq_sendrecv.msg_len,
1241 			context->mq_sendrecv.msg_prio,
1242 			context->mq_sendrecv.abs_timeout.tv_sec,
1243 			context->mq_sendrecv.abs_timeout.tv_nsec);
1244 		break;
1245 	case AUDIT_MQ_NOTIFY:
1246 		audit_log_format(ab, "mqdes=%d sigev_signo=%d",
1247 				context->mq_notify.mqdes,
1248 				context->mq_notify.sigev_signo);
1249 		break;
1250 	case AUDIT_MQ_GETSETATTR: {
1251 		struct mq_attr *attr = &context->mq_getsetattr.mqstat;
1252 		audit_log_format(ab,
1253 			"mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
1254 			"mq_curmsgs=%ld ",
1255 			context->mq_getsetattr.mqdes,
1256 			attr->mq_flags, attr->mq_maxmsg,
1257 			attr->mq_msgsize, attr->mq_curmsgs);
1258 		break; }
1259 	case AUDIT_CAPSET:
1260 		audit_log_format(ab, "pid=%d", context->capset.pid);
1261 		audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable);
1262 		audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted);
1263 		audit_log_cap(ab, "cap_pe", &context->capset.cap.effective);
1264 		break;
1265 	case AUDIT_MMAP:
1266 		audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd,
1267 				 context->mmap.flags);
1268 		break;
1269 	case AUDIT_EXECVE:
1270 		audit_log_execve_info(context, &ab);
1271 		break;
1272 	case AUDIT_KERN_MODULE:
1273 		audit_log_format(ab, "name=");
1274 		audit_log_untrustedstring(ab, context->module.name);
1275 		kfree(context->module.name);
1276 		break;
1277 	}
1278 	audit_log_end(ab);
1279 }
1280 
1281 static inline int audit_proctitle_rtrim(char *proctitle, int len)
1282 {
1283 	char *end = proctitle + len - 1;
1284 	while (end > proctitle && !isprint(*end))
1285 		end--;
1286 
1287 	/* catch the case where proctitle is only 1 non-print character */
1288 	len = end - proctitle + 1;
1289 	len -= isprint(proctitle[len-1]) == 0;
1290 	return len;
1291 }
1292 
1293 static void audit_log_proctitle(struct task_struct *tsk,
1294 			 struct audit_context *context)
1295 {
1296 	int res;
1297 	char *buf;
1298 	char *msg = "(null)";
1299 	int len = strlen(msg);
1300 	struct audit_buffer *ab;
1301 
1302 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_PROCTITLE);
1303 	if (!ab)
1304 		return;	/* audit_panic or being filtered */
1305 
1306 	audit_log_format(ab, "proctitle=");
1307 
1308 	/* Not  cached */
1309 	if (!context->proctitle.value) {
1310 		buf = kmalloc(MAX_PROCTITLE_AUDIT_LEN, GFP_KERNEL);
1311 		if (!buf)
1312 			goto out;
1313 		/* Historically called this from procfs naming */
1314 		res = get_cmdline(tsk, buf, MAX_PROCTITLE_AUDIT_LEN);
1315 		if (res == 0) {
1316 			kfree(buf);
1317 			goto out;
1318 		}
1319 		res = audit_proctitle_rtrim(buf, res);
1320 		if (res == 0) {
1321 			kfree(buf);
1322 			goto out;
1323 		}
1324 		context->proctitle.value = buf;
1325 		context->proctitle.len = res;
1326 	}
1327 	msg = context->proctitle.value;
1328 	len = context->proctitle.len;
1329 out:
1330 	audit_log_n_untrustedstring(ab, msg, len);
1331 	audit_log_end(ab);
1332 }
1333 
1334 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
1335 {
1336 	int i, call_panic = 0;
1337 	struct audit_buffer *ab;
1338 	struct audit_aux_data *aux;
1339 	struct audit_names *n;
1340 
1341 	/* tsk == current */
1342 	context->personality = tsk->personality;
1343 
1344 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
1345 	if (!ab)
1346 		return;		/* audit_panic has been called */
1347 	audit_log_format(ab, "arch=%x syscall=%d",
1348 			 context->arch, context->major);
1349 	if (context->personality != PER_LINUX)
1350 		audit_log_format(ab, " per=%lx", context->personality);
1351 	if (context->return_valid)
1352 		audit_log_format(ab, " success=%s exit=%ld",
1353 				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
1354 				 context->return_code);
1355 
1356 	audit_log_format(ab,
1357 			 " a0=%lx a1=%lx a2=%lx a3=%lx items=%d",
1358 			 context->argv[0],
1359 			 context->argv[1],
1360 			 context->argv[2],
1361 			 context->argv[3],
1362 			 context->name_count);
1363 
1364 	audit_log_task_info(ab, tsk);
1365 	audit_log_key(ab, context->filterkey);
1366 	audit_log_end(ab);
1367 
1368 	for (aux = context->aux; aux; aux = aux->next) {
1369 
1370 		ab = audit_log_start(context, GFP_KERNEL, aux->type);
1371 		if (!ab)
1372 			continue; /* audit_panic has been called */
1373 
1374 		switch (aux->type) {
1375 
1376 		case AUDIT_BPRM_FCAPS: {
1377 			struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
1378 			audit_log_format(ab, "fver=%x", axs->fcap_ver);
1379 			audit_log_cap(ab, "fp", &axs->fcap.permitted);
1380 			audit_log_cap(ab, "fi", &axs->fcap.inheritable);
1381 			audit_log_format(ab, " fe=%d", axs->fcap.fE);
1382 			audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted);
1383 			audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable);
1384 			audit_log_cap(ab, "old_pe", &axs->old_pcap.effective);
1385 			audit_log_cap(ab, "new_pp", &axs->new_pcap.permitted);
1386 			audit_log_cap(ab, "new_pi", &axs->new_pcap.inheritable);
1387 			audit_log_cap(ab, "new_pe", &axs->new_pcap.effective);
1388 			break; }
1389 
1390 		}
1391 		audit_log_end(ab);
1392 	}
1393 
1394 	if (context->type)
1395 		show_special(context, &call_panic);
1396 
1397 	if (context->fds[0] >= 0) {
1398 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR);
1399 		if (ab) {
1400 			audit_log_format(ab, "fd0=%d fd1=%d",
1401 					context->fds[0], context->fds[1]);
1402 			audit_log_end(ab);
1403 		}
1404 	}
1405 
1406 	if (context->sockaddr_len) {
1407 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
1408 		if (ab) {
1409 			audit_log_format(ab, "saddr=");
1410 			audit_log_n_hex(ab, (void *)context->sockaddr,
1411 					context->sockaddr_len);
1412 			audit_log_end(ab);
1413 		}
1414 	}
1415 
1416 	for (aux = context->aux_pids; aux; aux = aux->next) {
1417 		struct audit_aux_data_pids *axs = (void *)aux;
1418 
1419 		for (i = 0; i < axs->pid_count; i++)
1420 			if (audit_log_pid_context(context, axs->target_pid[i],
1421 						  axs->target_auid[i],
1422 						  axs->target_uid[i],
1423 						  axs->target_sessionid[i],
1424 						  axs->target_sid[i],
1425 						  axs->target_comm[i]))
1426 				call_panic = 1;
1427 	}
1428 
1429 	if (context->target_pid &&
1430 	    audit_log_pid_context(context, context->target_pid,
1431 				  context->target_auid, context->target_uid,
1432 				  context->target_sessionid,
1433 				  context->target_sid, context->target_comm))
1434 			call_panic = 1;
1435 
1436 	if (context->pwd.dentry && context->pwd.mnt) {
1437 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
1438 		if (ab) {
1439 			audit_log_d_path(ab, "cwd=", &context->pwd);
1440 			audit_log_end(ab);
1441 		}
1442 	}
1443 
1444 	i = 0;
1445 	list_for_each_entry(n, &context->names_list, list) {
1446 		if (n->hidden)
1447 			continue;
1448 		audit_log_name(context, n, NULL, i++, &call_panic);
1449 	}
1450 
1451 	audit_log_proctitle(tsk, context);
1452 
1453 	/* Send end of event record to help user space know we are finished */
1454 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
1455 	if (ab)
1456 		audit_log_end(ab);
1457 	if (call_panic)
1458 		audit_panic("error converting sid to string");
1459 }
1460 
1461 /**
1462  * audit_free - free a per-task audit context
1463  * @tsk: task whose audit context block to free
1464  *
1465  * Called from copy_process and do_exit
1466  */
1467 void __audit_free(struct task_struct *tsk)
1468 {
1469 	struct audit_context *context;
1470 
1471 	context = audit_take_context(tsk, 0, 0);
1472 	if (!context)
1473 		return;
1474 
1475 	/* Check for system calls that do not go through the exit
1476 	 * function (e.g., exit_group), then free context block.
1477 	 * We use GFP_ATOMIC here because we might be doing this
1478 	 * in the context of the idle thread */
1479 	/* that can happen only if we are called from do_exit() */
1480 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1481 		audit_log_exit(context, tsk);
1482 	if (!list_empty(&context->killed_trees))
1483 		audit_kill_trees(&context->killed_trees);
1484 
1485 	audit_free_context(context);
1486 }
1487 
1488 /**
1489  * audit_syscall_entry - fill in an audit record at syscall entry
1490  * @major: major syscall type (function)
1491  * @a1: additional syscall register 1
1492  * @a2: additional syscall register 2
1493  * @a3: additional syscall register 3
1494  * @a4: additional syscall register 4
1495  *
1496  * Fill in audit context at syscall entry.  This only happens if the
1497  * audit context was created when the task was created and the state or
1498  * filters demand the audit context be built.  If the state from the
1499  * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1500  * then the record will be written at syscall exit time (otherwise, it
1501  * will only be written if another part of the kernel requests that it
1502  * be written).
1503  */
1504 void __audit_syscall_entry(int major, unsigned long a1, unsigned long a2,
1505 			   unsigned long a3, unsigned long a4)
1506 {
1507 	struct task_struct *tsk = current;
1508 	struct audit_context *context = tsk->audit_context;
1509 	enum audit_state     state;
1510 
1511 	if (!context)
1512 		return;
1513 
1514 	BUG_ON(context->in_syscall || context->name_count);
1515 
1516 	if (!audit_enabled)
1517 		return;
1518 
1519 	context->arch	    = syscall_get_arch();
1520 	context->major      = major;
1521 	context->argv[0]    = a1;
1522 	context->argv[1]    = a2;
1523 	context->argv[2]    = a3;
1524 	context->argv[3]    = a4;
1525 
1526 	state = context->state;
1527 	context->dummy = !audit_n_rules;
1528 	if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
1529 		context->prio = 0;
1530 		state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
1531 	}
1532 	if (state == AUDIT_DISABLED)
1533 		return;
1534 
1535 	context->serial     = 0;
1536 	ktime_get_real_ts64(&context->ctime);
1537 	context->in_syscall = 1;
1538 	context->current_state  = state;
1539 	context->ppid       = 0;
1540 }
1541 
1542 /**
1543  * audit_syscall_exit - deallocate audit context after a system call
1544  * @success: success value of the syscall
1545  * @return_code: return value of the syscall
1546  *
1547  * Tear down after system call.  If the audit context has been marked as
1548  * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1549  * filtering, or because some other part of the kernel wrote an audit
1550  * message), then write out the syscall information.  In call cases,
1551  * free the names stored from getname().
1552  */
1553 void __audit_syscall_exit(int success, long return_code)
1554 {
1555 	struct task_struct *tsk = current;
1556 	struct audit_context *context;
1557 
1558 	if (success)
1559 		success = AUDITSC_SUCCESS;
1560 	else
1561 		success = AUDITSC_FAILURE;
1562 
1563 	context = audit_take_context(tsk, success, return_code);
1564 	if (!context)
1565 		return;
1566 
1567 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1568 		audit_log_exit(context, tsk);
1569 
1570 	context->in_syscall = 0;
1571 	context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
1572 
1573 	if (!list_empty(&context->killed_trees))
1574 		audit_kill_trees(&context->killed_trees);
1575 
1576 	audit_free_names(context);
1577 	unroll_tree_refs(context, NULL, 0);
1578 	audit_free_aux(context);
1579 	context->aux = NULL;
1580 	context->aux_pids = NULL;
1581 	context->target_pid = 0;
1582 	context->target_sid = 0;
1583 	context->sockaddr_len = 0;
1584 	context->type = 0;
1585 	context->fds[0] = -1;
1586 	if (context->state != AUDIT_RECORD_CONTEXT) {
1587 		kfree(context->filterkey);
1588 		context->filterkey = NULL;
1589 	}
1590 	tsk->audit_context = context;
1591 }
1592 
1593 static inline void handle_one(const struct inode *inode)
1594 {
1595 #ifdef CONFIG_AUDIT_TREE
1596 	struct audit_context *context;
1597 	struct audit_tree_refs *p;
1598 	struct audit_chunk *chunk;
1599 	int count;
1600 	if (likely(!inode->i_fsnotify_marks))
1601 		return;
1602 	context = current->audit_context;
1603 	p = context->trees;
1604 	count = context->tree_count;
1605 	rcu_read_lock();
1606 	chunk = audit_tree_lookup(inode);
1607 	rcu_read_unlock();
1608 	if (!chunk)
1609 		return;
1610 	if (likely(put_tree_ref(context, chunk)))
1611 		return;
1612 	if (unlikely(!grow_tree_refs(context))) {
1613 		pr_warn("out of memory, audit has lost a tree reference\n");
1614 		audit_set_auditable(context);
1615 		audit_put_chunk(chunk);
1616 		unroll_tree_refs(context, p, count);
1617 		return;
1618 	}
1619 	put_tree_ref(context, chunk);
1620 #endif
1621 }
1622 
1623 static void handle_path(const struct dentry *dentry)
1624 {
1625 #ifdef CONFIG_AUDIT_TREE
1626 	struct audit_context *context;
1627 	struct audit_tree_refs *p;
1628 	const struct dentry *d, *parent;
1629 	struct audit_chunk *drop;
1630 	unsigned long seq;
1631 	int count;
1632 
1633 	context = current->audit_context;
1634 	p = context->trees;
1635 	count = context->tree_count;
1636 retry:
1637 	drop = NULL;
1638 	d = dentry;
1639 	rcu_read_lock();
1640 	seq = read_seqbegin(&rename_lock);
1641 	for(;;) {
1642 		struct inode *inode = d_backing_inode(d);
1643 		if (inode && unlikely(inode->i_fsnotify_marks)) {
1644 			struct audit_chunk *chunk;
1645 			chunk = audit_tree_lookup(inode);
1646 			if (chunk) {
1647 				if (unlikely(!put_tree_ref(context, chunk))) {
1648 					drop = chunk;
1649 					break;
1650 				}
1651 			}
1652 		}
1653 		parent = d->d_parent;
1654 		if (parent == d)
1655 			break;
1656 		d = parent;
1657 	}
1658 	if (unlikely(read_seqretry(&rename_lock, seq) || drop)) {  /* in this order */
1659 		rcu_read_unlock();
1660 		if (!drop) {
1661 			/* just a race with rename */
1662 			unroll_tree_refs(context, p, count);
1663 			goto retry;
1664 		}
1665 		audit_put_chunk(drop);
1666 		if (grow_tree_refs(context)) {
1667 			/* OK, got more space */
1668 			unroll_tree_refs(context, p, count);
1669 			goto retry;
1670 		}
1671 		/* too bad */
1672 		pr_warn("out of memory, audit has lost a tree reference\n");
1673 		unroll_tree_refs(context, p, count);
1674 		audit_set_auditable(context);
1675 		return;
1676 	}
1677 	rcu_read_unlock();
1678 #endif
1679 }
1680 
1681 static struct audit_names *audit_alloc_name(struct audit_context *context,
1682 						unsigned char type)
1683 {
1684 	struct audit_names *aname;
1685 
1686 	if (context->name_count < AUDIT_NAMES) {
1687 		aname = &context->preallocated_names[context->name_count];
1688 		memset(aname, 0, sizeof(*aname));
1689 	} else {
1690 		aname = kzalloc(sizeof(*aname), GFP_NOFS);
1691 		if (!aname)
1692 			return NULL;
1693 		aname->should_free = true;
1694 	}
1695 
1696 	aname->ino = AUDIT_INO_UNSET;
1697 	aname->type = type;
1698 	list_add_tail(&aname->list, &context->names_list);
1699 
1700 	context->name_count++;
1701 	return aname;
1702 }
1703 
1704 /**
1705  * audit_reusename - fill out filename with info from existing entry
1706  * @uptr: userland ptr to pathname
1707  *
1708  * Search the audit_names list for the current audit context. If there is an
1709  * existing entry with a matching "uptr" then return the filename
1710  * associated with that audit_name. If not, return NULL.
1711  */
1712 struct filename *
1713 __audit_reusename(const __user char *uptr)
1714 {
1715 	struct audit_context *context = current->audit_context;
1716 	struct audit_names *n;
1717 
1718 	list_for_each_entry(n, &context->names_list, list) {
1719 		if (!n->name)
1720 			continue;
1721 		if (n->name->uptr == uptr) {
1722 			n->name->refcnt++;
1723 			return n->name;
1724 		}
1725 	}
1726 	return NULL;
1727 }
1728 
1729 /**
1730  * audit_getname - add a name to the list
1731  * @name: name to add
1732  *
1733  * Add a name to the list of audit names for this context.
1734  * Called from fs/namei.c:getname().
1735  */
1736 void __audit_getname(struct filename *name)
1737 {
1738 	struct audit_context *context = current->audit_context;
1739 	struct audit_names *n;
1740 
1741 	if (!context->in_syscall)
1742 		return;
1743 
1744 	n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1745 	if (!n)
1746 		return;
1747 
1748 	n->name = name;
1749 	n->name_len = AUDIT_NAME_FULL;
1750 	name->aname = n;
1751 	name->refcnt++;
1752 
1753 	if (!context->pwd.dentry)
1754 		get_fs_pwd(current->fs, &context->pwd);
1755 }
1756 
1757 /**
1758  * __audit_inode - store the inode and device from a lookup
1759  * @name: name being audited
1760  * @dentry: dentry being audited
1761  * @flags: attributes for this particular entry
1762  */
1763 void __audit_inode(struct filename *name, const struct dentry *dentry,
1764 		   unsigned int flags)
1765 {
1766 	struct audit_context *context = current->audit_context;
1767 	struct inode *inode = d_backing_inode(dentry);
1768 	struct audit_names *n;
1769 	bool parent = flags & AUDIT_INODE_PARENT;
1770 
1771 	if (!context->in_syscall)
1772 		return;
1773 
1774 	if (!name)
1775 		goto out_alloc;
1776 
1777 	/*
1778 	 * If we have a pointer to an audit_names entry already, then we can
1779 	 * just use it directly if the type is correct.
1780 	 */
1781 	n = name->aname;
1782 	if (n) {
1783 		if (parent) {
1784 			if (n->type == AUDIT_TYPE_PARENT ||
1785 			    n->type == AUDIT_TYPE_UNKNOWN)
1786 				goto out;
1787 		} else {
1788 			if (n->type != AUDIT_TYPE_PARENT)
1789 				goto out;
1790 		}
1791 	}
1792 
1793 	list_for_each_entry_reverse(n, &context->names_list, list) {
1794 		if (n->ino) {
1795 			/* valid inode number, use that for the comparison */
1796 			if (n->ino != inode->i_ino ||
1797 			    n->dev != inode->i_sb->s_dev)
1798 				continue;
1799 		} else if (n->name) {
1800 			/* inode number has not been set, check the name */
1801 			if (strcmp(n->name->name, name->name))
1802 				continue;
1803 		} else
1804 			/* no inode and no name (?!) ... this is odd ... */
1805 			continue;
1806 
1807 		/* match the correct record type */
1808 		if (parent) {
1809 			if (n->type == AUDIT_TYPE_PARENT ||
1810 			    n->type == AUDIT_TYPE_UNKNOWN)
1811 				goto out;
1812 		} else {
1813 			if (n->type != AUDIT_TYPE_PARENT)
1814 				goto out;
1815 		}
1816 	}
1817 
1818 out_alloc:
1819 	/* unable to find an entry with both a matching name and type */
1820 	n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1821 	if (!n)
1822 		return;
1823 	if (name) {
1824 		n->name = name;
1825 		name->refcnt++;
1826 	}
1827 
1828 out:
1829 	if (parent) {
1830 		n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL;
1831 		n->type = AUDIT_TYPE_PARENT;
1832 		if (flags & AUDIT_INODE_HIDDEN)
1833 			n->hidden = true;
1834 	} else {
1835 		n->name_len = AUDIT_NAME_FULL;
1836 		n->type = AUDIT_TYPE_NORMAL;
1837 	}
1838 	handle_path(dentry);
1839 	audit_copy_inode(n, dentry, inode);
1840 }
1841 
1842 void __audit_file(const struct file *file)
1843 {
1844 	__audit_inode(NULL, file->f_path.dentry, 0);
1845 }
1846 
1847 /**
1848  * __audit_inode_child - collect inode info for created/removed objects
1849  * @parent: inode of dentry parent
1850  * @dentry: dentry being audited
1851  * @type:   AUDIT_TYPE_* value that we're looking for
1852  *
1853  * For syscalls that create or remove filesystem objects, audit_inode
1854  * can only collect information for the filesystem object's parent.
1855  * This call updates the audit context with the child's information.
1856  * Syscalls that create a new filesystem object must be hooked after
1857  * the object is created.  Syscalls that remove a filesystem object
1858  * must be hooked prior, in order to capture the target inode during
1859  * unsuccessful attempts.
1860  */
1861 void __audit_inode_child(struct inode *parent,
1862 			 const struct dentry *dentry,
1863 			 const unsigned char type)
1864 {
1865 	struct audit_context *context = current->audit_context;
1866 	struct inode *inode = d_backing_inode(dentry);
1867 	const char *dname = dentry->d_name.name;
1868 	struct audit_names *n, *found_parent = NULL, *found_child = NULL;
1869 
1870 	if (!context->in_syscall)
1871 		return;
1872 
1873 	if (inode)
1874 		handle_one(inode);
1875 
1876 	/* look for a parent entry first */
1877 	list_for_each_entry(n, &context->names_list, list) {
1878 		if (!n->name ||
1879 		    (n->type != AUDIT_TYPE_PARENT &&
1880 		     n->type != AUDIT_TYPE_UNKNOWN))
1881 			continue;
1882 
1883 		if (n->ino == parent->i_ino && n->dev == parent->i_sb->s_dev &&
1884 		    !audit_compare_dname_path(dname,
1885 					      n->name->name, n->name_len)) {
1886 			if (n->type == AUDIT_TYPE_UNKNOWN)
1887 				n->type = AUDIT_TYPE_PARENT;
1888 			found_parent = n;
1889 			break;
1890 		}
1891 	}
1892 
1893 	/* is there a matching child entry? */
1894 	list_for_each_entry(n, &context->names_list, list) {
1895 		/* can only match entries that have a name */
1896 		if (!n->name ||
1897 		    (n->type != type && n->type != AUDIT_TYPE_UNKNOWN))
1898 			continue;
1899 
1900 		if (!strcmp(dname, n->name->name) ||
1901 		    !audit_compare_dname_path(dname, n->name->name,
1902 						found_parent ?
1903 						found_parent->name_len :
1904 						AUDIT_NAME_FULL)) {
1905 			if (n->type == AUDIT_TYPE_UNKNOWN)
1906 				n->type = type;
1907 			found_child = n;
1908 			break;
1909 		}
1910 	}
1911 
1912 	if (!found_parent) {
1913 		/* create a new, "anonymous" parent record */
1914 		n = audit_alloc_name(context, AUDIT_TYPE_PARENT);
1915 		if (!n)
1916 			return;
1917 		audit_copy_inode(n, NULL, parent);
1918 	}
1919 
1920 	if (!found_child) {
1921 		found_child = audit_alloc_name(context, type);
1922 		if (!found_child)
1923 			return;
1924 
1925 		/* Re-use the name belonging to the slot for a matching parent
1926 		 * directory. All names for this context are relinquished in
1927 		 * audit_free_names() */
1928 		if (found_parent) {
1929 			found_child->name = found_parent->name;
1930 			found_child->name_len = AUDIT_NAME_FULL;
1931 			found_child->name->refcnt++;
1932 		}
1933 	}
1934 
1935 	if (inode)
1936 		audit_copy_inode(found_child, dentry, inode);
1937 	else
1938 		found_child->ino = AUDIT_INO_UNSET;
1939 }
1940 EXPORT_SYMBOL_GPL(__audit_inode_child);
1941 
1942 /**
1943  * auditsc_get_stamp - get local copies of audit_context values
1944  * @ctx: audit_context for the task
1945  * @t: timespec64 to store time recorded in the audit_context
1946  * @serial: serial value that is recorded in the audit_context
1947  *
1948  * Also sets the context as auditable.
1949  */
1950 int auditsc_get_stamp(struct audit_context *ctx,
1951 		       struct timespec64 *t, unsigned int *serial)
1952 {
1953 	if (!ctx->in_syscall)
1954 		return 0;
1955 	if (!ctx->serial)
1956 		ctx->serial = audit_serial();
1957 	t->tv_sec  = ctx->ctime.tv_sec;
1958 	t->tv_nsec = ctx->ctime.tv_nsec;
1959 	*serial    = ctx->serial;
1960 	if (!ctx->prio) {
1961 		ctx->prio = 1;
1962 		ctx->current_state = AUDIT_RECORD_CONTEXT;
1963 	}
1964 	return 1;
1965 }
1966 
1967 /* global counter which is incremented every time something logs in */
1968 static atomic_t session_id = ATOMIC_INIT(0);
1969 
1970 static int audit_set_loginuid_perm(kuid_t loginuid)
1971 {
1972 	/* if we are unset, we don't need privs */
1973 	if (!audit_loginuid_set(current))
1974 		return 0;
1975 	/* if AUDIT_FEATURE_LOGINUID_IMMUTABLE means never ever allow a change*/
1976 	if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
1977 		return -EPERM;
1978 	/* it is set, you need permission */
1979 	if (!capable(CAP_AUDIT_CONTROL))
1980 		return -EPERM;
1981 	/* reject if this is not an unset and we don't allow that */
1982 	if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID) && uid_valid(loginuid))
1983 		return -EPERM;
1984 	return 0;
1985 }
1986 
1987 static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
1988 				   unsigned int oldsessionid, unsigned int sessionid,
1989 				   int rc)
1990 {
1991 	struct audit_buffer *ab;
1992 	uid_t uid, oldloginuid, loginuid;
1993 	struct tty_struct *tty;
1994 
1995 	if (!audit_enabled)
1996 		return;
1997 
1998 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
1999 	if (!ab)
2000 		return;
2001 
2002 	uid = from_kuid(&init_user_ns, task_uid(current));
2003 	oldloginuid = from_kuid(&init_user_ns, koldloginuid);
2004 	loginuid = from_kuid(&init_user_ns, kloginuid),
2005 	tty = audit_get_tty(current);
2006 
2007 	audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
2008 	audit_log_task_context(ab);
2009 	audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
2010 			 oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
2011 			 oldsessionid, sessionid, !rc);
2012 	audit_put_tty(tty);
2013 	audit_log_end(ab);
2014 }
2015 
2016 /**
2017  * audit_set_loginuid - set current task's audit_context loginuid
2018  * @loginuid: loginuid value
2019  *
2020  * Returns 0.
2021  *
2022  * Called (set) from fs/proc/base.c::proc_loginuid_write().
2023  */
2024 int audit_set_loginuid(kuid_t loginuid)
2025 {
2026 	struct task_struct *task = current;
2027 	unsigned int oldsessionid, sessionid = (unsigned int)-1;
2028 	kuid_t oldloginuid;
2029 	int rc;
2030 
2031 	oldloginuid = audit_get_loginuid(current);
2032 	oldsessionid = audit_get_sessionid(current);
2033 
2034 	rc = audit_set_loginuid_perm(loginuid);
2035 	if (rc)
2036 		goto out;
2037 
2038 	/* are we setting or clearing? */
2039 	if (uid_valid(loginuid)) {
2040 		sessionid = (unsigned int)atomic_inc_return(&session_id);
2041 		if (unlikely(sessionid == (unsigned int)-1))
2042 			sessionid = (unsigned int)atomic_inc_return(&session_id);
2043 	}
2044 
2045 	task->sessionid = sessionid;
2046 	task->loginuid = loginuid;
2047 out:
2048 	audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
2049 	return rc;
2050 }
2051 
2052 /**
2053  * __audit_mq_open - record audit data for a POSIX MQ open
2054  * @oflag: open flag
2055  * @mode: mode bits
2056  * @attr: queue attributes
2057  *
2058  */
2059 void __audit_mq_open(int oflag, umode_t mode, struct mq_attr *attr)
2060 {
2061 	struct audit_context *context = current->audit_context;
2062 
2063 	if (attr)
2064 		memcpy(&context->mq_open.attr, attr, sizeof(struct mq_attr));
2065 	else
2066 		memset(&context->mq_open.attr, 0, sizeof(struct mq_attr));
2067 
2068 	context->mq_open.oflag = oflag;
2069 	context->mq_open.mode = mode;
2070 
2071 	context->type = AUDIT_MQ_OPEN;
2072 }
2073 
2074 /**
2075  * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive
2076  * @mqdes: MQ descriptor
2077  * @msg_len: Message length
2078  * @msg_prio: Message priority
2079  * @abs_timeout: Message timeout in absolute time
2080  *
2081  */
2082 void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
2083 			const struct timespec *abs_timeout)
2084 {
2085 	struct audit_context *context = current->audit_context;
2086 	struct timespec *p = &context->mq_sendrecv.abs_timeout;
2087 
2088 	if (abs_timeout)
2089 		memcpy(p, abs_timeout, sizeof(struct timespec));
2090 	else
2091 		memset(p, 0, sizeof(struct timespec));
2092 
2093 	context->mq_sendrecv.mqdes = mqdes;
2094 	context->mq_sendrecv.msg_len = msg_len;
2095 	context->mq_sendrecv.msg_prio = msg_prio;
2096 
2097 	context->type = AUDIT_MQ_SENDRECV;
2098 }
2099 
2100 /**
2101  * __audit_mq_notify - record audit data for a POSIX MQ notify
2102  * @mqdes: MQ descriptor
2103  * @notification: Notification event
2104  *
2105  */
2106 
2107 void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
2108 {
2109 	struct audit_context *context = current->audit_context;
2110 
2111 	if (notification)
2112 		context->mq_notify.sigev_signo = notification->sigev_signo;
2113 	else
2114 		context->mq_notify.sigev_signo = 0;
2115 
2116 	context->mq_notify.mqdes = mqdes;
2117 	context->type = AUDIT_MQ_NOTIFY;
2118 }
2119 
2120 /**
2121  * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
2122  * @mqdes: MQ descriptor
2123  * @mqstat: MQ flags
2124  *
2125  */
2126 void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
2127 {
2128 	struct audit_context *context = current->audit_context;
2129 	context->mq_getsetattr.mqdes = mqdes;
2130 	context->mq_getsetattr.mqstat = *mqstat;
2131 	context->type = AUDIT_MQ_GETSETATTR;
2132 }
2133 
2134 /**
2135  * audit_ipc_obj - record audit data for ipc object
2136  * @ipcp: ipc permissions
2137  *
2138  */
2139 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
2140 {
2141 	struct audit_context *context = current->audit_context;
2142 	context->ipc.uid = ipcp->uid;
2143 	context->ipc.gid = ipcp->gid;
2144 	context->ipc.mode = ipcp->mode;
2145 	context->ipc.has_perm = 0;
2146 	security_ipc_getsecid(ipcp, &context->ipc.osid);
2147 	context->type = AUDIT_IPC;
2148 }
2149 
2150 /**
2151  * audit_ipc_set_perm - record audit data for new ipc permissions
2152  * @qbytes: msgq bytes
2153  * @uid: msgq user id
2154  * @gid: msgq group id
2155  * @mode: msgq mode (permissions)
2156  *
2157  * Called only after audit_ipc_obj().
2158  */
2159 void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode)
2160 {
2161 	struct audit_context *context = current->audit_context;
2162 
2163 	context->ipc.qbytes = qbytes;
2164 	context->ipc.perm_uid = uid;
2165 	context->ipc.perm_gid = gid;
2166 	context->ipc.perm_mode = mode;
2167 	context->ipc.has_perm = 1;
2168 }
2169 
2170 void __audit_bprm(struct linux_binprm *bprm)
2171 {
2172 	struct audit_context *context = current->audit_context;
2173 
2174 	context->type = AUDIT_EXECVE;
2175 	context->execve.argc = bprm->argc;
2176 }
2177 
2178 
2179 /**
2180  * audit_socketcall - record audit data for sys_socketcall
2181  * @nargs: number of args, which should not be more than AUDITSC_ARGS.
2182  * @args: args array
2183  *
2184  */
2185 int __audit_socketcall(int nargs, unsigned long *args)
2186 {
2187 	struct audit_context *context = current->audit_context;
2188 
2189 	if (nargs <= 0 || nargs > AUDITSC_ARGS || !args)
2190 		return -EINVAL;
2191 	context->type = AUDIT_SOCKETCALL;
2192 	context->socketcall.nargs = nargs;
2193 	memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long));
2194 	return 0;
2195 }
2196 
2197 /**
2198  * __audit_fd_pair - record audit data for pipe and socketpair
2199  * @fd1: the first file descriptor
2200  * @fd2: the second file descriptor
2201  *
2202  */
2203 void __audit_fd_pair(int fd1, int fd2)
2204 {
2205 	struct audit_context *context = current->audit_context;
2206 	context->fds[0] = fd1;
2207 	context->fds[1] = fd2;
2208 }
2209 
2210 /**
2211  * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
2212  * @len: data length in user space
2213  * @a: data address in kernel space
2214  *
2215  * Returns 0 for success or NULL context or < 0 on error.
2216  */
2217 int __audit_sockaddr(int len, void *a)
2218 {
2219 	struct audit_context *context = current->audit_context;
2220 
2221 	if (!context->sockaddr) {
2222 		void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL);
2223 		if (!p)
2224 			return -ENOMEM;
2225 		context->sockaddr = p;
2226 	}
2227 
2228 	context->sockaddr_len = len;
2229 	memcpy(context->sockaddr, a, len);
2230 	return 0;
2231 }
2232 
2233 void __audit_ptrace(struct task_struct *t)
2234 {
2235 	struct audit_context *context = current->audit_context;
2236 
2237 	context->target_pid = task_tgid_nr(t);
2238 	context->target_auid = audit_get_loginuid(t);
2239 	context->target_uid = task_uid(t);
2240 	context->target_sessionid = audit_get_sessionid(t);
2241 	security_task_getsecid(t, &context->target_sid);
2242 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
2243 }
2244 
2245 /**
2246  * audit_signal_info - record signal info for shutting down audit subsystem
2247  * @sig: signal value
2248  * @t: task being signaled
2249  *
2250  * If the audit subsystem is being terminated, record the task (pid)
2251  * and uid that is doing that.
2252  */
2253 int audit_signal_info(int sig, struct task_struct *t)
2254 {
2255 	struct audit_aux_data_pids *axp;
2256 	struct task_struct *tsk = current;
2257 	struct audit_context *ctx = tsk->audit_context;
2258 	kuid_t uid = current_uid(), t_uid = task_uid(t);
2259 
2260 	if (auditd_test_task(t) &&
2261 	    (sig == SIGTERM || sig == SIGHUP ||
2262 	     sig == SIGUSR1 || sig == SIGUSR2)) {
2263 		audit_sig_pid = task_tgid_nr(tsk);
2264 		if (uid_valid(tsk->loginuid))
2265 			audit_sig_uid = tsk->loginuid;
2266 		else
2267 			audit_sig_uid = uid;
2268 		security_task_getsecid(tsk, &audit_sig_sid);
2269 	}
2270 
2271 	if (!audit_signals || audit_dummy_context())
2272 		return 0;
2273 
2274 	/* optimize the common case by putting first signal recipient directly
2275 	 * in audit_context */
2276 	if (!ctx->target_pid) {
2277 		ctx->target_pid = task_tgid_nr(t);
2278 		ctx->target_auid = audit_get_loginuid(t);
2279 		ctx->target_uid = t_uid;
2280 		ctx->target_sessionid = audit_get_sessionid(t);
2281 		security_task_getsecid(t, &ctx->target_sid);
2282 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
2283 		return 0;
2284 	}
2285 
2286 	axp = (void *)ctx->aux_pids;
2287 	if (!axp || axp->pid_count == AUDIT_AUX_PIDS) {
2288 		axp = kzalloc(sizeof(*axp), GFP_ATOMIC);
2289 		if (!axp)
2290 			return -ENOMEM;
2291 
2292 		axp->d.type = AUDIT_OBJ_PID;
2293 		axp->d.next = ctx->aux_pids;
2294 		ctx->aux_pids = (void *)axp;
2295 	}
2296 	BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);
2297 
2298 	axp->target_pid[axp->pid_count] = task_tgid_nr(t);
2299 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
2300 	axp->target_uid[axp->pid_count] = t_uid;
2301 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
2302 	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
2303 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
2304 	axp->pid_count++;
2305 
2306 	return 0;
2307 }
2308 
2309 /**
2310  * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps
2311  * @bprm: pointer to the bprm being processed
2312  * @new: the proposed new credentials
2313  * @old: the old credentials
2314  *
2315  * Simply check if the proc already has the caps given by the file and if not
2316  * store the priv escalation info for later auditing at the end of the syscall
2317  *
2318  * -Eric
2319  */
2320 int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
2321 			   const struct cred *new, const struct cred *old)
2322 {
2323 	struct audit_aux_data_bprm_fcaps *ax;
2324 	struct audit_context *context = current->audit_context;
2325 	struct cpu_vfs_cap_data vcaps;
2326 
2327 	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2328 	if (!ax)
2329 		return -ENOMEM;
2330 
2331 	ax->d.type = AUDIT_BPRM_FCAPS;
2332 	ax->d.next = context->aux;
2333 	context->aux = (void *)ax;
2334 
2335 	get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps);
2336 
2337 	ax->fcap.permitted = vcaps.permitted;
2338 	ax->fcap.inheritable = vcaps.inheritable;
2339 	ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2340 	ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
2341 
2342 	ax->old_pcap.permitted   = old->cap_permitted;
2343 	ax->old_pcap.inheritable = old->cap_inheritable;
2344 	ax->old_pcap.effective   = old->cap_effective;
2345 
2346 	ax->new_pcap.permitted   = new->cap_permitted;
2347 	ax->new_pcap.inheritable = new->cap_inheritable;
2348 	ax->new_pcap.effective   = new->cap_effective;
2349 	return 0;
2350 }
2351 
2352 /**
2353  * __audit_log_capset - store information about the arguments to the capset syscall
2354  * @new: the new credentials
2355  * @old: the old (current) credentials
2356  *
2357  * Record the arguments userspace sent to sys_capset for later printing by the
2358  * audit system if applicable
2359  */
2360 void __audit_log_capset(const struct cred *new, const struct cred *old)
2361 {
2362 	struct audit_context *context = current->audit_context;
2363 	context->capset.pid = task_tgid_nr(current);
2364 	context->capset.cap.effective   = new->cap_effective;
2365 	context->capset.cap.inheritable = new->cap_effective;
2366 	context->capset.cap.permitted   = new->cap_permitted;
2367 	context->type = AUDIT_CAPSET;
2368 }
2369 
2370 void __audit_mmap_fd(int fd, int flags)
2371 {
2372 	struct audit_context *context = current->audit_context;
2373 	context->mmap.fd = fd;
2374 	context->mmap.flags = flags;
2375 	context->type = AUDIT_MMAP;
2376 }
2377 
2378 void __audit_log_kern_module(char *name)
2379 {
2380 	struct audit_context *context = current->audit_context;
2381 
2382 	context->module.name = kmalloc(strlen(name) + 1, GFP_KERNEL);
2383 	strcpy(context->module.name, name);
2384 	context->type = AUDIT_KERN_MODULE;
2385 }
2386 
2387 static void audit_log_task(struct audit_buffer *ab)
2388 {
2389 	kuid_t auid, uid;
2390 	kgid_t gid;
2391 	unsigned int sessionid;
2392 	char comm[sizeof(current->comm)];
2393 
2394 	auid = audit_get_loginuid(current);
2395 	sessionid = audit_get_sessionid(current);
2396 	current_uid_gid(&uid, &gid);
2397 
2398 	audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
2399 			 from_kuid(&init_user_ns, auid),
2400 			 from_kuid(&init_user_ns, uid),
2401 			 from_kgid(&init_user_ns, gid),
2402 			 sessionid);
2403 	audit_log_task_context(ab);
2404 	audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
2405 	audit_log_untrustedstring(ab, get_task_comm(comm, current));
2406 	audit_log_d_path_exe(ab, current->mm);
2407 }
2408 
2409 /**
2410  * audit_core_dumps - record information about processes that end abnormally
2411  * @signr: signal value
2412  *
2413  * If a process ends with a core dump, something fishy is going on and we
2414  * should record the event for investigation.
2415  */
2416 void audit_core_dumps(long signr)
2417 {
2418 	struct audit_buffer *ab;
2419 
2420 	if (!audit_enabled)
2421 		return;
2422 
2423 	if (signr == SIGQUIT)	/* don't care for those */
2424 		return;
2425 
2426 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
2427 	if (unlikely(!ab))
2428 		return;
2429 	audit_log_task(ab);
2430 	audit_log_format(ab, " sig=%ld res=1", signr);
2431 	audit_log_end(ab);
2432 }
2433 
2434 void __audit_seccomp(unsigned long syscall, long signr, int code)
2435 {
2436 	struct audit_buffer *ab;
2437 
2438 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
2439 	if (unlikely(!ab))
2440 		return;
2441 	audit_log_task(ab);
2442 	audit_log_format(ab, " sig=%ld arch=%x syscall=%ld compat=%d ip=0x%lx code=0x%x",
2443 			 signr, syscall_get_arch(), syscall,
2444 			 in_compat_syscall(), KSTK_EIP(current), code);
2445 	audit_log_end(ab);
2446 }
2447 
2448 struct list_head *audit_killed_trees(void)
2449 {
2450 	struct audit_context *ctx = current->audit_context;
2451 	if (likely(!ctx || !ctx->in_syscall))
2452 		return NULL;
2453 	return &ctx->killed_trees;
2454 }
2455