xref: /linux/kernel/auditsc.c (revision 4e0385dd7469d933c4adf84a617f872ca547aa07)
1 /* auditsc.c -- System-call auditing support
2  * Handles all system-call specific auditing features.
3  *
4  * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
5  * Copyright 2005 Hewlett-Packard Development Company, L.P.
6  * Copyright (C) 2005, 2006 IBM Corporation
7  * All Rights Reserved.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
22  *
23  * Written by Rickard E. (Rik) Faith <faith@redhat.com>
24  *
25  * Many of the ideas implemented here are from Stephen C. Tweedie,
26  * especially the idea of avoiding a copy by using getname.
27  *
28  * The method for actual interception of syscall entry and exit (not in
29  * this file -- see entry.S) is based on a GPL'd patch written by
30  * okir@suse.de and Copyright 2003 SuSE Linux AG.
31  *
32  * POSIX message queue support added by George Wilson <ltcgcw@us.ibm.com>,
33  * 2006.
34  *
35  * The support of additional filter rules compares (>, <, >=, <=) was
36  * added by Dustin Kirkland <dustin.kirkland@us.ibm.com>, 2005.
37  *
38  * Modified by Amy Griffis <amy.griffis@hp.com> to collect additional
39  * filesystem information.
40  *
41  * Subject and object context labeling support added by <danjones@us.ibm.com>
42  * and <dustin.kirkland@us.ibm.com> for LSPP certification compliance.
43  */
44 
45 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
46 
47 #include <linux/init.h>
48 #include <asm/types.h>
49 #include <linux/atomic.h>
50 #include <linux/fs.h>
51 #include <linux/namei.h>
52 #include <linux/mm.h>
53 #include <linux/export.h>
54 #include <linux/slab.h>
55 #include <linux/mount.h>
56 #include <linux/socket.h>
57 #include <linux/mqueue.h>
58 #include <linux/audit.h>
59 #include <linux/personality.h>
60 #include <linux/time.h>
61 #include <linux/netlink.h>
62 #include <linux/compiler.h>
63 #include <asm/unistd.h>
64 #include <linux/security.h>
65 #include <linux/list.h>
66 #include <linux/binfmts.h>
67 #include <linux/highmem.h>
68 #include <linux/syscalls.h>
69 #include <asm/syscall.h>
70 #include <linux/capability.h>
71 #include <linux/fs_struct.h>
72 #include <linux/compat.h>
73 #include <linux/ctype.h>
74 #include <linux/string.h>
75 #include <linux/uaccess.h>
76 #include <uapi/linux/limits.h>
77 
78 #include "audit.h"
79 
80 /* flags stating the success for a syscall */
81 #define AUDITSC_INVALID 0
82 #define AUDITSC_SUCCESS 1
83 #define AUDITSC_FAILURE 2
84 
85 /* no execve audit message should be longer than this (userspace limits),
86  * see the note near the top of audit_log_execve_info() about this value */
87 #define MAX_EXECVE_AUDIT_LEN 7500
88 
89 /* max length to print of cmdline/proctitle value during audit */
90 #define MAX_PROCTITLE_AUDIT_LEN 128
91 
92 /* number of audit rules */
93 int audit_n_rules;
94 
95 /* determines whether we collect data for signals sent */
96 int audit_signals;
97 
98 struct audit_aux_data {
99 	struct audit_aux_data	*next;
100 	int			type;
101 };
102 
103 #define AUDIT_AUX_IPCPERM	0
104 
105 /* Number of target pids per aux struct. */
106 #define AUDIT_AUX_PIDS	16
107 
108 struct audit_aux_data_pids {
109 	struct audit_aux_data	d;
110 	pid_t			target_pid[AUDIT_AUX_PIDS];
111 	kuid_t			target_auid[AUDIT_AUX_PIDS];
112 	kuid_t			target_uid[AUDIT_AUX_PIDS];
113 	unsigned int		target_sessionid[AUDIT_AUX_PIDS];
114 	u32			target_sid[AUDIT_AUX_PIDS];
115 	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
116 	int			pid_count;
117 };
118 
119 struct audit_aux_data_bprm_fcaps {
120 	struct audit_aux_data	d;
121 	struct audit_cap_data	fcap;
122 	unsigned int		fcap_ver;
123 	struct audit_cap_data	old_pcap;
124 	struct audit_cap_data	new_pcap;
125 };
126 
127 struct audit_tree_refs {
128 	struct audit_tree_refs *next;
129 	struct audit_chunk *c[31];
130 };
131 
132 static int audit_match_perm(struct audit_context *ctx, int mask)
133 {
134 	unsigned n;
135 	if (unlikely(!ctx))
136 		return 0;
137 	n = ctx->major;
138 
139 	switch (audit_classify_syscall(ctx->arch, n)) {
140 	case 0:	/* native */
141 		if ((mask & AUDIT_PERM_WRITE) &&
142 		     audit_match_class(AUDIT_CLASS_WRITE, n))
143 			return 1;
144 		if ((mask & AUDIT_PERM_READ) &&
145 		     audit_match_class(AUDIT_CLASS_READ, n))
146 			return 1;
147 		if ((mask & AUDIT_PERM_ATTR) &&
148 		     audit_match_class(AUDIT_CLASS_CHATTR, n))
149 			return 1;
150 		return 0;
151 	case 1: /* 32bit on biarch */
152 		if ((mask & AUDIT_PERM_WRITE) &&
153 		     audit_match_class(AUDIT_CLASS_WRITE_32, n))
154 			return 1;
155 		if ((mask & AUDIT_PERM_READ) &&
156 		     audit_match_class(AUDIT_CLASS_READ_32, n))
157 			return 1;
158 		if ((mask & AUDIT_PERM_ATTR) &&
159 		     audit_match_class(AUDIT_CLASS_CHATTR_32, n))
160 			return 1;
161 		return 0;
162 	case 2: /* open */
163 		return mask & ACC_MODE(ctx->argv[1]);
164 	case 3: /* openat */
165 		return mask & ACC_MODE(ctx->argv[2]);
166 	case 4: /* socketcall */
167 		return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND);
168 	case 5: /* execve */
169 		return mask & AUDIT_PERM_EXEC;
170 	default:
171 		return 0;
172 	}
173 }
174 
175 static int audit_match_filetype(struct audit_context *ctx, int val)
176 {
177 	struct audit_names *n;
178 	umode_t mode = (umode_t)val;
179 
180 	if (unlikely(!ctx))
181 		return 0;
182 
183 	list_for_each_entry(n, &ctx->names_list, list) {
184 		if ((n->ino != AUDIT_INO_UNSET) &&
185 		    ((n->mode & S_IFMT) == mode))
186 			return 1;
187 	}
188 
189 	return 0;
190 }
191 
192 /*
193  * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
194  * ->first_trees points to its beginning, ->trees - to the current end of data.
195  * ->tree_count is the number of free entries in array pointed to by ->trees.
196  * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
197  * "empty" becomes (p, p, 31) afterwards.  We don't shrink the list (and seriously,
198  * it's going to remain 1-element for almost any setup) until we free context itself.
199  * References in it _are_ dropped - at the same time we free/drop aux stuff.
200  */
201 
202 #ifdef CONFIG_AUDIT_TREE
203 static void audit_set_auditable(struct audit_context *ctx)
204 {
205 	if (!ctx->prio) {
206 		ctx->prio = 1;
207 		ctx->current_state = AUDIT_RECORD_CONTEXT;
208 	}
209 }
210 
211 static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
212 {
213 	struct audit_tree_refs *p = ctx->trees;
214 	int left = ctx->tree_count;
215 	if (likely(left)) {
216 		p->c[--left] = chunk;
217 		ctx->tree_count = left;
218 		return 1;
219 	}
220 	if (!p)
221 		return 0;
222 	p = p->next;
223 	if (p) {
224 		p->c[30] = chunk;
225 		ctx->trees = p;
226 		ctx->tree_count = 30;
227 		return 1;
228 	}
229 	return 0;
230 }
231 
232 static int grow_tree_refs(struct audit_context *ctx)
233 {
234 	struct audit_tree_refs *p = ctx->trees;
235 	ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
236 	if (!ctx->trees) {
237 		ctx->trees = p;
238 		return 0;
239 	}
240 	if (p)
241 		p->next = ctx->trees;
242 	else
243 		ctx->first_trees = ctx->trees;
244 	ctx->tree_count = 31;
245 	return 1;
246 }
247 #endif
248 
249 static void unroll_tree_refs(struct audit_context *ctx,
250 		      struct audit_tree_refs *p, int count)
251 {
252 #ifdef CONFIG_AUDIT_TREE
253 	struct audit_tree_refs *q;
254 	int n;
255 	if (!p) {
256 		/* we started with empty chain */
257 		p = ctx->first_trees;
258 		count = 31;
259 		/* if the very first allocation has failed, nothing to do */
260 		if (!p)
261 			return;
262 	}
263 	n = count;
264 	for (q = p; q != ctx->trees; q = q->next, n = 31) {
265 		while (n--) {
266 			audit_put_chunk(q->c[n]);
267 			q->c[n] = NULL;
268 		}
269 	}
270 	while (n-- > ctx->tree_count) {
271 		audit_put_chunk(q->c[n]);
272 		q->c[n] = NULL;
273 	}
274 	ctx->trees = p;
275 	ctx->tree_count = count;
276 #endif
277 }
278 
279 static void free_tree_refs(struct audit_context *ctx)
280 {
281 	struct audit_tree_refs *p, *q;
282 	for (p = ctx->first_trees; p; p = q) {
283 		q = p->next;
284 		kfree(p);
285 	}
286 }
287 
288 static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
289 {
290 #ifdef CONFIG_AUDIT_TREE
291 	struct audit_tree_refs *p;
292 	int n;
293 	if (!tree)
294 		return 0;
295 	/* full ones */
296 	for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
297 		for (n = 0; n < 31; n++)
298 			if (audit_tree_match(p->c[n], tree))
299 				return 1;
300 	}
301 	/* partial */
302 	if (p) {
303 		for (n = ctx->tree_count; n < 31; n++)
304 			if (audit_tree_match(p->c[n], tree))
305 				return 1;
306 	}
307 #endif
308 	return 0;
309 }
310 
311 static int audit_compare_uid(kuid_t uid,
312 			     struct audit_names *name,
313 			     struct audit_field *f,
314 			     struct audit_context *ctx)
315 {
316 	struct audit_names *n;
317 	int rc;
318 
319 	if (name) {
320 		rc = audit_uid_comparator(uid, f->op, name->uid);
321 		if (rc)
322 			return rc;
323 	}
324 
325 	if (ctx) {
326 		list_for_each_entry(n, &ctx->names_list, list) {
327 			rc = audit_uid_comparator(uid, f->op, n->uid);
328 			if (rc)
329 				return rc;
330 		}
331 	}
332 	return 0;
333 }
334 
335 static int audit_compare_gid(kgid_t gid,
336 			     struct audit_names *name,
337 			     struct audit_field *f,
338 			     struct audit_context *ctx)
339 {
340 	struct audit_names *n;
341 	int rc;
342 
343 	if (name) {
344 		rc = audit_gid_comparator(gid, f->op, name->gid);
345 		if (rc)
346 			return rc;
347 	}
348 
349 	if (ctx) {
350 		list_for_each_entry(n, &ctx->names_list, list) {
351 			rc = audit_gid_comparator(gid, f->op, n->gid);
352 			if (rc)
353 				return rc;
354 		}
355 	}
356 	return 0;
357 }
358 
359 static int audit_field_compare(struct task_struct *tsk,
360 			       const struct cred *cred,
361 			       struct audit_field *f,
362 			       struct audit_context *ctx,
363 			       struct audit_names *name)
364 {
365 	switch (f->val) {
366 	/* process to file object comparisons */
367 	case AUDIT_COMPARE_UID_TO_OBJ_UID:
368 		return audit_compare_uid(cred->uid, name, f, ctx);
369 	case AUDIT_COMPARE_GID_TO_OBJ_GID:
370 		return audit_compare_gid(cred->gid, name, f, ctx);
371 	case AUDIT_COMPARE_EUID_TO_OBJ_UID:
372 		return audit_compare_uid(cred->euid, name, f, ctx);
373 	case AUDIT_COMPARE_EGID_TO_OBJ_GID:
374 		return audit_compare_gid(cred->egid, name, f, ctx);
375 	case AUDIT_COMPARE_AUID_TO_OBJ_UID:
376 		return audit_compare_uid(tsk->loginuid, name, f, ctx);
377 	case AUDIT_COMPARE_SUID_TO_OBJ_UID:
378 		return audit_compare_uid(cred->suid, name, f, ctx);
379 	case AUDIT_COMPARE_SGID_TO_OBJ_GID:
380 		return audit_compare_gid(cred->sgid, name, f, ctx);
381 	case AUDIT_COMPARE_FSUID_TO_OBJ_UID:
382 		return audit_compare_uid(cred->fsuid, name, f, ctx);
383 	case AUDIT_COMPARE_FSGID_TO_OBJ_GID:
384 		return audit_compare_gid(cred->fsgid, name, f, ctx);
385 	/* uid comparisons */
386 	case AUDIT_COMPARE_UID_TO_AUID:
387 		return audit_uid_comparator(cred->uid, f->op, tsk->loginuid);
388 	case AUDIT_COMPARE_UID_TO_EUID:
389 		return audit_uid_comparator(cred->uid, f->op, cred->euid);
390 	case AUDIT_COMPARE_UID_TO_SUID:
391 		return audit_uid_comparator(cred->uid, f->op, cred->suid);
392 	case AUDIT_COMPARE_UID_TO_FSUID:
393 		return audit_uid_comparator(cred->uid, f->op, cred->fsuid);
394 	/* auid comparisons */
395 	case AUDIT_COMPARE_AUID_TO_EUID:
396 		return audit_uid_comparator(tsk->loginuid, f->op, cred->euid);
397 	case AUDIT_COMPARE_AUID_TO_SUID:
398 		return audit_uid_comparator(tsk->loginuid, f->op, cred->suid);
399 	case AUDIT_COMPARE_AUID_TO_FSUID:
400 		return audit_uid_comparator(tsk->loginuid, f->op, cred->fsuid);
401 	/* euid comparisons */
402 	case AUDIT_COMPARE_EUID_TO_SUID:
403 		return audit_uid_comparator(cred->euid, f->op, cred->suid);
404 	case AUDIT_COMPARE_EUID_TO_FSUID:
405 		return audit_uid_comparator(cred->euid, f->op, cred->fsuid);
406 	/* suid comparisons */
407 	case AUDIT_COMPARE_SUID_TO_FSUID:
408 		return audit_uid_comparator(cred->suid, f->op, cred->fsuid);
409 	/* gid comparisons */
410 	case AUDIT_COMPARE_GID_TO_EGID:
411 		return audit_gid_comparator(cred->gid, f->op, cred->egid);
412 	case AUDIT_COMPARE_GID_TO_SGID:
413 		return audit_gid_comparator(cred->gid, f->op, cred->sgid);
414 	case AUDIT_COMPARE_GID_TO_FSGID:
415 		return audit_gid_comparator(cred->gid, f->op, cred->fsgid);
416 	/* egid comparisons */
417 	case AUDIT_COMPARE_EGID_TO_SGID:
418 		return audit_gid_comparator(cred->egid, f->op, cred->sgid);
419 	case AUDIT_COMPARE_EGID_TO_FSGID:
420 		return audit_gid_comparator(cred->egid, f->op, cred->fsgid);
421 	/* sgid comparison */
422 	case AUDIT_COMPARE_SGID_TO_FSGID:
423 		return audit_gid_comparator(cred->sgid, f->op, cred->fsgid);
424 	default:
425 		WARN(1, "Missing AUDIT_COMPARE define.  Report as a bug\n");
426 		return 0;
427 	}
428 	return 0;
429 }
430 
431 /* Determine if any context name data matches a rule's watch data */
432 /* Compare a task_struct with an audit_rule.  Return 1 on match, 0
433  * otherwise.
434  *
435  * If task_creation is true, this is an explicit indication that we are
436  * filtering a task rule at task creation time.  This and tsk == current are
437  * the only situations where tsk->cred may be accessed without an rcu read lock.
438  */
439 static int audit_filter_rules(struct task_struct *tsk,
440 			      struct audit_krule *rule,
441 			      struct audit_context *ctx,
442 			      struct audit_names *name,
443 			      enum audit_state *state,
444 			      bool task_creation)
445 {
446 	const struct cred *cred;
447 	int i, need_sid = 1;
448 	u32 sid;
449 	unsigned int sessionid;
450 
451 	cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
452 
453 	for (i = 0; i < rule->field_count; i++) {
454 		struct audit_field *f = &rule->fields[i];
455 		struct audit_names *n;
456 		int result = 0;
457 		pid_t pid;
458 
459 		switch (f->type) {
460 		case AUDIT_PID:
461 			pid = task_tgid_nr(tsk);
462 			result = audit_comparator(pid, f->op, f->val);
463 			break;
464 		case AUDIT_PPID:
465 			if (ctx) {
466 				if (!ctx->ppid)
467 					ctx->ppid = task_ppid_nr(tsk);
468 				result = audit_comparator(ctx->ppid, f->op, f->val);
469 			}
470 			break;
471 		case AUDIT_EXE:
472 			result = audit_exe_compare(tsk, rule->exe);
473 			break;
474 		case AUDIT_UID:
475 			result = audit_uid_comparator(cred->uid, f->op, f->uid);
476 			break;
477 		case AUDIT_EUID:
478 			result = audit_uid_comparator(cred->euid, f->op, f->uid);
479 			break;
480 		case AUDIT_SUID:
481 			result = audit_uid_comparator(cred->suid, f->op, f->uid);
482 			break;
483 		case AUDIT_FSUID:
484 			result = audit_uid_comparator(cred->fsuid, f->op, f->uid);
485 			break;
486 		case AUDIT_GID:
487 			result = audit_gid_comparator(cred->gid, f->op, f->gid);
488 			if (f->op == Audit_equal) {
489 				if (!result)
490 					result = in_group_p(f->gid);
491 			} else if (f->op == Audit_not_equal) {
492 				if (result)
493 					result = !in_group_p(f->gid);
494 			}
495 			break;
496 		case AUDIT_EGID:
497 			result = audit_gid_comparator(cred->egid, f->op, f->gid);
498 			if (f->op == Audit_equal) {
499 				if (!result)
500 					result = in_egroup_p(f->gid);
501 			} else if (f->op == Audit_not_equal) {
502 				if (result)
503 					result = !in_egroup_p(f->gid);
504 			}
505 			break;
506 		case AUDIT_SGID:
507 			result = audit_gid_comparator(cred->sgid, f->op, f->gid);
508 			break;
509 		case AUDIT_FSGID:
510 			result = audit_gid_comparator(cred->fsgid, f->op, f->gid);
511 			break;
512 		case AUDIT_SESSIONID:
513 			sessionid = audit_get_sessionid(current);
514 			result = audit_comparator(sessionid, f->op, f->val);
515 			break;
516 		case AUDIT_PERS:
517 			result = audit_comparator(tsk->personality, f->op, f->val);
518 			break;
519 		case AUDIT_ARCH:
520 			if (ctx)
521 				result = audit_comparator(ctx->arch, f->op, f->val);
522 			break;
523 
524 		case AUDIT_EXIT:
525 			if (ctx && ctx->return_valid)
526 				result = audit_comparator(ctx->return_code, f->op, f->val);
527 			break;
528 		case AUDIT_SUCCESS:
529 			if (ctx && ctx->return_valid) {
530 				if (f->val)
531 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
532 				else
533 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);
534 			}
535 			break;
536 		case AUDIT_DEVMAJOR:
537 			if (name) {
538 				if (audit_comparator(MAJOR(name->dev), f->op, f->val) ||
539 				    audit_comparator(MAJOR(name->rdev), f->op, f->val))
540 					++result;
541 			} else if (ctx) {
542 				list_for_each_entry(n, &ctx->names_list, list) {
543 					if (audit_comparator(MAJOR(n->dev), f->op, f->val) ||
544 					    audit_comparator(MAJOR(n->rdev), f->op, f->val)) {
545 						++result;
546 						break;
547 					}
548 				}
549 			}
550 			break;
551 		case AUDIT_DEVMINOR:
552 			if (name) {
553 				if (audit_comparator(MINOR(name->dev), f->op, f->val) ||
554 				    audit_comparator(MINOR(name->rdev), f->op, f->val))
555 					++result;
556 			} else if (ctx) {
557 				list_for_each_entry(n, &ctx->names_list, list) {
558 					if (audit_comparator(MINOR(n->dev), f->op, f->val) ||
559 					    audit_comparator(MINOR(n->rdev), f->op, f->val)) {
560 						++result;
561 						break;
562 					}
563 				}
564 			}
565 			break;
566 		case AUDIT_INODE:
567 			if (name)
568 				result = audit_comparator(name->ino, f->op, f->val);
569 			else if (ctx) {
570 				list_for_each_entry(n, &ctx->names_list, list) {
571 					if (audit_comparator(n->ino, f->op, f->val)) {
572 						++result;
573 						break;
574 					}
575 				}
576 			}
577 			break;
578 		case AUDIT_OBJ_UID:
579 			if (name) {
580 				result = audit_uid_comparator(name->uid, f->op, f->uid);
581 			} else if (ctx) {
582 				list_for_each_entry(n, &ctx->names_list, list) {
583 					if (audit_uid_comparator(n->uid, f->op, f->uid)) {
584 						++result;
585 						break;
586 					}
587 				}
588 			}
589 			break;
590 		case AUDIT_OBJ_GID:
591 			if (name) {
592 				result = audit_gid_comparator(name->gid, f->op, f->gid);
593 			} else if (ctx) {
594 				list_for_each_entry(n, &ctx->names_list, list) {
595 					if (audit_gid_comparator(n->gid, f->op, f->gid)) {
596 						++result;
597 						break;
598 					}
599 				}
600 			}
601 			break;
602 		case AUDIT_WATCH:
603 			if (name)
604 				result = audit_watch_compare(rule->watch, name->ino, name->dev);
605 			break;
606 		case AUDIT_DIR:
607 			if (ctx)
608 				result = match_tree_refs(ctx, rule->tree);
609 			break;
610 		case AUDIT_LOGINUID:
611 			result = audit_uid_comparator(tsk->loginuid, f->op, f->uid);
612 			break;
613 		case AUDIT_LOGINUID_SET:
614 			result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
615 			break;
616 		case AUDIT_SUBJ_USER:
617 		case AUDIT_SUBJ_ROLE:
618 		case AUDIT_SUBJ_TYPE:
619 		case AUDIT_SUBJ_SEN:
620 		case AUDIT_SUBJ_CLR:
621 			/* NOTE: this may return negative values indicating
622 			   a temporary error.  We simply treat this as a
623 			   match for now to avoid losing information that
624 			   may be wanted.   An error message will also be
625 			   logged upon error */
626 			if (f->lsm_rule) {
627 				if (need_sid) {
628 					security_task_getsecid(tsk, &sid);
629 					need_sid = 0;
630 				}
631 				result = security_audit_rule_match(sid, f->type,
632 				                                  f->op,
633 				                                  f->lsm_rule,
634 				                                  ctx);
635 			}
636 			break;
637 		case AUDIT_OBJ_USER:
638 		case AUDIT_OBJ_ROLE:
639 		case AUDIT_OBJ_TYPE:
640 		case AUDIT_OBJ_LEV_LOW:
641 		case AUDIT_OBJ_LEV_HIGH:
642 			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
643 			   also applies here */
644 			if (f->lsm_rule) {
645 				/* Find files that match */
646 				if (name) {
647 					result = security_audit_rule_match(
648 					           name->osid, f->type, f->op,
649 					           f->lsm_rule, ctx);
650 				} else if (ctx) {
651 					list_for_each_entry(n, &ctx->names_list, list) {
652 						if (security_audit_rule_match(n->osid, f->type,
653 									      f->op, f->lsm_rule,
654 									      ctx)) {
655 							++result;
656 							break;
657 						}
658 					}
659 				}
660 				/* Find ipc objects that match */
661 				if (!ctx || ctx->type != AUDIT_IPC)
662 					break;
663 				if (security_audit_rule_match(ctx->ipc.osid,
664 							      f->type, f->op,
665 							      f->lsm_rule, ctx))
666 					++result;
667 			}
668 			break;
669 		case AUDIT_ARG0:
670 		case AUDIT_ARG1:
671 		case AUDIT_ARG2:
672 		case AUDIT_ARG3:
673 			if (ctx)
674 				result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
675 			break;
676 		case AUDIT_FILTERKEY:
677 			/* ignore this field for filtering */
678 			result = 1;
679 			break;
680 		case AUDIT_PERM:
681 			result = audit_match_perm(ctx, f->val);
682 			break;
683 		case AUDIT_FILETYPE:
684 			result = audit_match_filetype(ctx, f->val);
685 			break;
686 		case AUDIT_FIELD_COMPARE:
687 			result = audit_field_compare(tsk, cred, f, ctx, name);
688 			break;
689 		}
690 		if (!result)
691 			return 0;
692 	}
693 
694 	if (ctx) {
695 		if (rule->prio <= ctx->prio)
696 			return 0;
697 		if (rule->filterkey) {
698 			kfree(ctx->filterkey);
699 			ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
700 		}
701 		ctx->prio = rule->prio;
702 	}
703 	switch (rule->action) {
704 	case AUDIT_NEVER:
705 		*state = AUDIT_DISABLED;
706 		break;
707 	case AUDIT_ALWAYS:
708 		*state = AUDIT_RECORD_CONTEXT;
709 		break;
710 	}
711 	return 1;
712 }
713 
714 /* At process creation time, we can determine if system-call auditing is
715  * completely disabled for this task.  Since we only have the task
716  * structure at this point, we can only check uid and gid.
717  */
718 static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
719 {
720 	struct audit_entry *e;
721 	enum audit_state   state;
722 
723 	rcu_read_lock();
724 	list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
725 		if (audit_filter_rules(tsk, &e->rule, NULL, NULL,
726 				       &state, true)) {
727 			if (state == AUDIT_RECORD_CONTEXT)
728 				*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
729 			rcu_read_unlock();
730 			return state;
731 		}
732 	}
733 	rcu_read_unlock();
734 	return AUDIT_BUILD_CONTEXT;
735 }
736 
737 static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
738 {
739 	int word, bit;
740 
741 	if (val > 0xffffffff)
742 		return false;
743 
744 	word = AUDIT_WORD(val);
745 	if (word >= AUDIT_BITMASK_SIZE)
746 		return false;
747 
748 	bit = AUDIT_BIT(val);
749 
750 	return rule->mask[word] & bit;
751 }
752 
753 /* At syscall entry and exit time, this filter is called if the
754  * audit_state is not low enough that auditing cannot take place, but is
755  * also not high enough that we already know we have to write an audit
756  * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
757  */
758 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
759 					     struct audit_context *ctx,
760 					     struct list_head *list)
761 {
762 	struct audit_entry *e;
763 	enum audit_state state;
764 
765 	if (audit_pid && tsk->tgid == audit_pid)
766 		return AUDIT_DISABLED;
767 
768 	rcu_read_lock();
769 	if (!list_empty(list)) {
770 		list_for_each_entry_rcu(e, list, list) {
771 			if (audit_in_mask(&e->rule, ctx->major) &&
772 			    audit_filter_rules(tsk, &e->rule, ctx, NULL,
773 					       &state, false)) {
774 				rcu_read_unlock();
775 				ctx->current_state = state;
776 				return state;
777 			}
778 		}
779 	}
780 	rcu_read_unlock();
781 	return AUDIT_BUILD_CONTEXT;
782 }
783 
784 /*
785  * Given an audit_name check the inode hash table to see if they match.
786  * Called holding the rcu read lock to protect the use of audit_inode_hash
787  */
788 static int audit_filter_inode_name(struct task_struct *tsk,
789 				   struct audit_names *n,
790 				   struct audit_context *ctx) {
791 	int h = audit_hash_ino((u32)n->ino);
792 	struct list_head *list = &audit_inode_hash[h];
793 	struct audit_entry *e;
794 	enum audit_state state;
795 
796 	if (list_empty(list))
797 		return 0;
798 
799 	list_for_each_entry_rcu(e, list, list) {
800 		if (audit_in_mask(&e->rule, ctx->major) &&
801 		    audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {
802 			ctx->current_state = state;
803 			return 1;
804 		}
805 	}
806 
807 	return 0;
808 }
809 
810 /* At syscall exit time, this filter is called if any audit_names have been
811  * collected during syscall processing.  We only check rules in sublists at hash
812  * buckets applicable to the inode numbers in audit_names.
813  * Regarding audit_state, same rules apply as for audit_filter_syscall().
814  */
815 void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
816 {
817 	struct audit_names *n;
818 
819 	if (audit_pid && tsk->tgid == audit_pid)
820 		return;
821 
822 	rcu_read_lock();
823 
824 	list_for_each_entry(n, &ctx->names_list, list) {
825 		if (audit_filter_inode_name(tsk, n, ctx))
826 			break;
827 	}
828 	rcu_read_unlock();
829 }
830 
831 /* Transfer the audit context pointer to the caller, clearing it in the tsk's struct */
832 static inline struct audit_context *audit_take_context(struct task_struct *tsk,
833 						      int return_valid,
834 						      long return_code)
835 {
836 	struct audit_context *context = tsk->audit_context;
837 
838 	if (!context)
839 		return NULL;
840 	context->return_valid = return_valid;
841 
842 	/*
843 	 * we need to fix up the return code in the audit logs if the actual
844 	 * return codes are later going to be fixed up by the arch specific
845 	 * signal handlers
846 	 *
847 	 * This is actually a test for:
848 	 * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) ||
849 	 * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK)
850 	 *
851 	 * but is faster than a bunch of ||
852 	 */
853 	if (unlikely(return_code <= -ERESTARTSYS) &&
854 	    (return_code >= -ERESTART_RESTARTBLOCK) &&
855 	    (return_code != -ENOIOCTLCMD))
856 		context->return_code = -EINTR;
857 	else
858 		context->return_code  = return_code;
859 
860 	if (context->in_syscall && !context->dummy) {
861 		audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
862 		audit_filter_inodes(tsk, context);
863 	}
864 
865 	tsk->audit_context = NULL;
866 	return context;
867 }
868 
869 static inline void audit_proctitle_free(struct audit_context *context)
870 {
871 	kfree(context->proctitle.value);
872 	context->proctitle.value = NULL;
873 	context->proctitle.len = 0;
874 }
875 
876 static inline void audit_free_names(struct audit_context *context)
877 {
878 	struct audit_names *n, *next;
879 
880 	list_for_each_entry_safe(n, next, &context->names_list, list) {
881 		list_del(&n->list);
882 		if (n->name)
883 			putname(n->name);
884 		if (n->should_free)
885 			kfree(n);
886 	}
887 	context->name_count = 0;
888 	path_put(&context->pwd);
889 	context->pwd.dentry = NULL;
890 	context->pwd.mnt = NULL;
891 }
892 
893 static inline void audit_free_aux(struct audit_context *context)
894 {
895 	struct audit_aux_data *aux;
896 
897 	while ((aux = context->aux)) {
898 		context->aux = aux->next;
899 		kfree(aux);
900 	}
901 	while ((aux = context->aux_pids)) {
902 		context->aux_pids = aux->next;
903 		kfree(aux);
904 	}
905 }
906 
907 static inline struct audit_context *audit_alloc_context(enum audit_state state)
908 {
909 	struct audit_context *context;
910 
911 	context = kzalloc(sizeof(*context), GFP_KERNEL);
912 	if (!context)
913 		return NULL;
914 	context->state = state;
915 	context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
916 	INIT_LIST_HEAD(&context->killed_trees);
917 	INIT_LIST_HEAD(&context->names_list);
918 	return context;
919 }
920 
921 /**
922  * audit_alloc - allocate an audit context block for a task
923  * @tsk: task
924  *
925  * Filter on the task information and allocate a per-task audit context
926  * if necessary.  Doing so turns on system call auditing for the
927  * specified task.  This is called from copy_process, so no lock is
928  * needed.
929  */
930 int audit_alloc(struct task_struct *tsk)
931 {
932 	struct audit_context *context;
933 	enum audit_state     state;
934 	char *key = NULL;
935 
936 	if (likely(!audit_ever_enabled))
937 		return 0; /* Return if not auditing. */
938 
939 	state = audit_filter_task(tsk, &key);
940 	if (state == AUDIT_DISABLED) {
941 		clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
942 		return 0;
943 	}
944 
945 	if (!(context = audit_alloc_context(state))) {
946 		kfree(key);
947 		audit_log_lost("out of memory in audit_alloc");
948 		return -ENOMEM;
949 	}
950 	context->filterkey = key;
951 
952 	tsk->audit_context  = context;
953 	set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
954 	return 0;
955 }
956 
957 static inline void audit_free_context(struct audit_context *context)
958 {
959 	audit_free_names(context);
960 	unroll_tree_refs(context, NULL, 0);
961 	free_tree_refs(context);
962 	audit_free_aux(context);
963 	kfree(context->filterkey);
964 	kfree(context->sockaddr);
965 	audit_proctitle_free(context);
966 	kfree(context);
967 }
968 
969 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
970 				 kuid_t auid, kuid_t uid, unsigned int sessionid,
971 				 u32 sid, char *comm)
972 {
973 	struct audit_buffer *ab;
974 	char *ctx = NULL;
975 	u32 len;
976 	int rc = 0;
977 
978 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
979 	if (!ab)
980 		return rc;
981 
982 	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
983 			 from_kuid(&init_user_ns, auid),
984 			 from_kuid(&init_user_ns, uid), sessionid);
985 	if (sid) {
986 		if (security_secid_to_secctx(sid, &ctx, &len)) {
987 			audit_log_format(ab, " obj=(none)");
988 			rc = 1;
989 		} else {
990 			audit_log_format(ab, " obj=%s", ctx);
991 			security_release_secctx(ctx, len);
992 		}
993 	}
994 	audit_log_format(ab, " ocomm=");
995 	audit_log_untrustedstring(ab, comm);
996 	audit_log_end(ab);
997 
998 	return rc;
999 }
1000 
1001 static void audit_log_execve_info(struct audit_context *context,
1002 				  struct audit_buffer **ab)
1003 {
1004 	long len_max;
1005 	long len_rem;
1006 	long len_full;
1007 	long len_buf;
1008 	long len_abuf = 0;
1009 	long len_tmp;
1010 	bool require_data;
1011 	bool encode;
1012 	unsigned int iter;
1013 	unsigned int arg;
1014 	char *buf_head;
1015 	char *buf;
1016 	const char __user *p = (const char __user *)current->mm->arg_start;
1017 
1018 	/* NOTE: this buffer needs to be large enough to hold all the non-arg
1019 	 *       data we put in the audit record for this argument (see the
1020 	 *       code below) ... at this point in time 96 is plenty */
1021 	char abuf[96];
1022 
1023 	/* NOTE: we set MAX_EXECVE_AUDIT_LEN to a rather arbitrary limit, the
1024 	 *       current value of 7500 is not as important as the fact that it
1025 	 *       is less than 8k, a setting of 7500 gives us plenty of wiggle
1026 	 *       room if we go over a little bit in the logging below */
1027 	WARN_ON_ONCE(MAX_EXECVE_AUDIT_LEN > 7500);
1028 	len_max = MAX_EXECVE_AUDIT_LEN;
1029 
1030 	/* scratch buffer to hold the userspace args */
1031 	buf_head = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL);
1032 	if (!buf_head) {
1033 		audit_panic("out of memory for argv string");
1034 		return;
1035 	}
1036 	buf = buf_head;
1037 
1038 	audit_log_format(*ab, "argc=%d", context->execve.argc);
1039 
1040 	len_rem = len_max;
1041 	len_buf = 0;
1042 	len_full = 0;
1043 	require_data = true;
1044 	encode = false;
1045 	iter = 0;
1046 	arg = 0;
1047 	do {
1048 		/* NOTE: we don't ever want to trust this value for anything
1049 		 *       serious, but the audit record format insists we
1050 		 *       provide an argument length for really long arguments,
1051 		 *       e.g. > MAX_EXECVE_AUDIT_LEN, so we have no choice but
1052 		 *       to use strncpy_from_user() to obtain this value for
1053 		 *       recording in the log, although we don't use it
1054 		 *       anywhere here to avoid a double-fetch problem */
1055 		if (len_full == 0)
1056 			len_full = strnlen_user(p, MAX_ARG_STRLEN) - 1;
1057 
1058 		/* read more data from userspace */
1059 		if (require_data) {
1060 			/* can we make more room in the buffer? */
1061 			if (buf != buf_head) {
1062 				memmove(buf_head, buf, len_buf);
1063 				buf = buf_head;
1064 			}
1065 
1066 			/* fetch as much as we can of the argument */
1067 			len_tmp = strncpy_from_user(&buf_head[len_buf], p,
1068 						    len_max - len_buf);
1069 			if (len_tmp == -EFAULT) {
1070 				/* unable to copy from userspace */
1071 				send_sig(SIGKILL, current, 0);
1072 				goto out;
1073 			} else if (len_tmp == (len_max - len_buf)) {
1074 				/* buffer is not large enough */
1075 				require_data = true;
1076 				/* NOTE: if we are going to span multiple
1077 				 *       buffers force the encoding so we stand
1078 				 *       a chance at a sane len_full value and
1079 				 *       consistent record encoding */
1080 				encode = true;
1081 				len_full = len_full * 2;
1082 				p += len_tmp;
1083 			} else {
1084 				require_data = false;
1085 				if (!encode)
1086 					encode = audit_string_contains_control(
1087 								buf, len_tmp);
1088 				/* try to use a trusted value for len_full */
1089 				if (len_full < len_max)
1090 					len_full = (encode ?
1091 						    len_tmp * 2 : len_tmp);
1092 				p += len_tmp + 1;
1093 			}
1094 			len_buf += len_tmp;
1095 			buf_head[len_buf] = '\0';
1096 
1097 			/* length of the buffer in the audit record? */
1098 			len_abuf = (encode ? len_buf * 2 : len_buf + 2);
1099 		}
1100 
1101 		/* write as much as we can to the audit log */
1102 		if (len_buf > 0) {
1103 			/* NOTE: some magic numbers here - basically if we
1104 			 *       can't fit a reasonable amount of data into the
1105 			 *       existing audit buffer, flush it and start with
1106 			 *       a new buffer */
1107 			if ((sizeof(abuf) + 8) > len_rem) {
1108 				len_rem = len_max;
1109 				audit_log_end(*ab);
1110 				*ab = audit_log_start(context,
1111 						      GFP_KERNEL, AUDIT_EXECVE);
1112 				if (!*ab)
1113 					goto out;
1114 			}
1115 
1116 			/* create the non-arg portion of the arg record */
1117 			len_tmp = 0;
1118 			if (require_data || (iter > 0) ||
1119 			    ((len_abuf + sizeof(abuf)) > len_rem)) {
1120 				if (iter == 0) {
1121 					len_tmp += snprintf(&abuf[len_tmp],
1122 							sizeof(abuf) - len_tmp,
1123 							" a%d_len=%lu",
1124 							arg, len_full);
1125 				}
1126 				len_tmp += snprintf(&abuf[len_tmp],
1127 						    sizeof(abuf) - len_tmp,
1128 						    " a%d[%d]=", arg, iter++);
1129 			} else
1130 				len_tmp += snprintf(&abuf[len_tmp],
1131 						    sizeof(abuf) - len_tmp,
1132 						    " a%d=", arg);
1133 			WARN_ON(len_tmp >= sizeof(abuf));
1134 			abuf[sizeof(abuf) - 1] = '\0';
1135 
1136 			/* log the arg in the audit record */
1137 			audit_log_format(*ab, "%s", abuf);
1138 			len_rem -= len_tmp;
1139 			len_tmp = len_buf;
1140 			if (encode) {
1141 				if (len_abuf > len_rem)
1142 					len_tmp = len_rem / 2; /* encoding */
1143 				audit_log_n_hex(*ab, buf, len_tmp);
1144 				len_rem -= len_tmp * 2;
1145 				len_abuf -= len_tmp * 2;
1146 			} else {
1147 				if (len_abuf > len_rem)
1148 					len_tmp = len_rem - 2; /* quotes */
1149 				audit_log_n_string(*ab, buf, len_tmp);
1150 				len_rem -= len_tmp + 2;
1151 				/* don't subtract the "2" because we still need
1152 				 * to add quotes to the remaining string */
1153 				len_abuf -= len_tmp;
1154 			}
1155 			len_buf -= len_tmp;
1156 			buf += len_tmp;
1157 		}
1158 
1159 		/* ready to move to the next argument? */
1160 		if ((len_buf == 0) && !require_data) {
1161 			arg++;
1162 			iter = 0;
1163 			len_full = 0;
1164 			require_data = true;
1165 			encode = false;
1166 		}
1167 	} while (arg < context->execve.argc);
1168 
1169 	/* NOTE: the caller handles the final audit_log_end() call */
1170 
1171 out:
1172 	kfree(buf_head);
1173 }
1174 
1175 static void show_special(struct audit_context *context, int *call_panic)
1176 {
1177 	struct audit_buffer *ab;
1178 	int i;
1179 
1180 	ab = audit_log_start(context, GFP_KERNEL, context->type);
1181 	if (!ab)
1182 		return;
1183 
1184 	switch (context->type) {
1185 	case AUDIT_SOCKETCALL: {
1186 		int nargs = context->socketcall.nargs;
1187 		audit_log_format(ab, "nargs=%d", nargs);
1188 		for (i = 0; i < nargs; i++)
1189 			audit_log_format(ab, " a%d=%lx", i,
1190 				context->socketcall.args[i]);
1191 		break; }
1192 	case AUDIT_IPC: {
1193 		u32 osid = context->ipc.osid;
1194 
1195 		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
1196 				 from_kuid(&init_user_ns, context->ipc.uid),
1197 				 from_kgid(&init_user_ns, context->ipc.gid),
1198 				 context->ipc.mode);
1199 		if (osid) {
1200 			char *ctx = NULL;
1201 			u32 len;
1202 			if (security_secid_to_secctx(osid, &ctx, &len)) {
1203 				audit_log_format(ab, " osid=%u", osid);
1204 				*call_panic = 1;
1205 			} else {
1206 				audit_log_format(ab, " obj=%s", ctx);
1207 				security_release_secctx(ctx, len);
1208 			}
1209 		}
1210 		if (context->ipc.has_perm) {
1211 			audit_log_end(ab);
1212 			ab = audit_log_start(context, GFP_KERNEL,
1213 					     AUDIT_IPC_SET_PERM);
1214 			if (unlikely(!ab))
1215 				return;
1216 			audit_log_format(ab,
1217 				"qbytes=%lx ouid=%u ogid=%u mode=%#ho",
1218 				context->ipc.qbytes,
1219 				context->ipc.perm_uid,
1220 				context->ipc.perm_gid,
1221 				context->ipc.perm_mode);
1222 		}
1223 		break; }
1224 	case AUDIT_MQ_OPEN:
1225 		audit_log_format(ab,
1226 			"oflag=0x%x mode=%#ho mq_flags=0x%lx mq_maxmsg=%ld "
1227 			"mq_msgsize=%ld mq_curmsgs=%ld",
1228 			context->mq_open.oflag, context->mq_open.mode,
1229 			context->mq_open.attr.mq_flags,
1230 			context->mq_open.attr.mq_maxmsg,
1231 			context->mq_open.attr.mq_msgsize,
1232 			context->mq_open.attr.mq_curmsgs);
1233 		break;
1234 	case AUDIT_MQ_SENDRECV:
1235 		audit_log_format(ab,
1236 			"mqdes=%d msg_len=%zd msg_prio=%u "
1237 			"abs_timeout_sec=%ld abs_timeout_nsec=%ld",
1238 			context->mq_sendrecv.mqdes,
1239 			context->mq_sendrecv.msg_len,
1240 			context->mq_sendrecv.msg_prio,
1241 			context->mq_sendrecv.abs_timeout.tv_sec,
1242 			context->mq_sendrecv.abs_timeout.tv_nsec);
1243 		break;
1244 	case AUDIT_MQ_NOTIFY:
1245 		audit_log_format(ab, "mqdes=%d sigev_signo=%d",
1246 				context->mq_notify.mqdes,
1247 				context->mq_notify.sigev_signo);
1248 		break;
1249 	case AUDIT_MQ_GETSETATTR: {
1250 		struct mq_attr *attr = &context->mq_getsetattr.mqstat;
1251 		audit_log_format(ab,
1252 			"mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
1253 			"mq_curmsgs=%ld ",
1254 			context->mq_getsetattr.mqdes,
1255 			attr->mq_flags, attr->mq_maxmsg,
1256 			attr->mq_msgsize, attr->mq_curmsgs);
1257 		break; }
1258 	case AUDIT_CAPSET:
1259 		audit_log_format(ab, "pid=%d", context->capset.pid);
1260 		audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable);
1261 		audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted);
1262 		audit_log_cap(ab, "cap_pe", &context->capset.cap.effective);
1263 		break;
1264 	case AUDIT_MMAP:
1265 		audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd,
1266 				 context->mmap.flags);
1267 		break;
1268 	case AUDIT_EXECVE:
1269 		audit_log_execve_info(context, &ab);
1270 		break;
1271 	case AUDIT_KERN_MODULE:
1272 		audit_log_format(ab, "name=");
1273 		audit_log_untrustedstring(ab, context->module.name);
1274 		kfree(context->module.name);
1275 		break;
1276 	}
1277 	audit_log_end(ab);
1278 }
1279 
1280 static inline int audit_proctitle_rtrim(char *proctitle, int len)
1281 {
1282 	char *end = proctitle + len - 1;
1283 	while (end > proctitle && !isprint(*end))
1284 		end--;
1285 
1286 	/* catch the case where proctitle is only 1 non-print character */
1287 	len = end - proctitle + 1;
1288 	len -= isprint(proctitle[len-1]) == 0;
1289 	return len;
1290 }
1291 
1292 static void audit_log_proctitle(struct task_struct *tsk,
1293 			 struct audit_context *context)
1294 {
1295 	int res;
1296 	char *buf;
1297 	char *msg = "(null)";
1298 	int len = strlen(msg);
1299 	struct audit_buffer *ab;
1300 
1301 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_PROCTITLE);
1302 	if (!ab)
1303 		return;	/* audit_panic or being filtered */
1304 
1305 	audit_log_format(ab, "proctitle=");
1306 
1307 	/* Not  cached */
1308 	if (!context->proctitle.value) {
1309 		buf = kmalloc(MAX_PROCTITLE_AUDIT_LEN, GFP_KERNEL);
1310 		if (!buf)
1311 			goto out;
1312 		/* Historically called this from procfs naming */
1313 		res = get_cmdline(tsk, buf, MAX_PROCTITLE_AUDIT_LEN);
1314 		if (res == 0) {
1315 			kfree(buf);
1316 			goto out;
1317 		}
1318 		res = audit_proctitle_rtrim(buf, res);
1319 		if (res == 0) {
1320 			kfree(buf);
1321 			goto out;
1322 		}
1323 		context->proctitle.value = buf;
1324 		context->proctitle.len = res;
1325 	}
1326 	msg = context->proctitle.value;
1327 	len = context->proctitle.len;
1328 out:
1329 	audit_log_n_untrustedstring(ab, msg, len);
1330 	audit_log_end(ab);
1331 }
1332 
1333 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
1334 {
1335 	int i, call_panic = 0;
1336 	struct audit_buffer *ab;
1337 	struct audit_aux_data *aux;
1338 	struct audit_names *n;
1339 
1340 	/* tsk == current */
1341 	context->personality = tsk->personality;
1342 
1343 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
1344 	if (!ab)
1345 		return;		/* audit_panic has been called */
1346 	audit_log_format(ab, "arch=%x syscall=%d",
1347 			 context->arch, context->major);
1348 	if (context->personality != PER_LINUX)
1349 		audit_log_format(ab, " per=%lx", context->personality);
1350 	if (context->return_valid)
1351 		audit_log_format(ab, " success=%s exit=%ld",
1352 				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
1353 				 context->return_code);
1354 
1355 	audit_log_format(ab,
1356 			 " a0=%lx a1=%lx a2=%lx a3=%lx items=%d",
1357 			 context->argv[0],
1358 			 context->argv[1],
1359 			 context->argv[2],
1360 			 context->argv[3],
1361 			 context->name_count);
1362 
1363 	audit_log_task_info(ab, tsk);
1364 	audit_log_key(ab, context->filterkey);
1365 	audit_log_end(ab);
1366 
1367 	for (aux = context->aux; aux; aux = aux->next) {
1368 
1369 		ab = audit_log_start(context, GFP_KERNEL, aux->type);
1370 		if (!ab)
1371 			continue; /* audit_panic has been called */
1372 
1373 		switch (aux->type) {
1374 
1375 		case AUDIT_BPRM_FCAPS: {
1376 			struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
1377 			audit_log_format(ab, "fver=%x", axs->fcap_ver);
1378 			audit_log_cap(ab, "fp", &axs->fcap.permitted);
1379 			audit_log_cap(ab, "fi", &axs->fcap.inheritable);
1380 			audit_log_format(ab, " fe=%d", axs->fcap.fE);
1381 			audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted);
1382 			audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable);
1383 			audit_log_cap(ab, "old_pe", &axs->old_pcap.effective);
1384 			audit_log_cap(ab, "new_pp", &axs->new_pcap.permitted);
1385 			audit_log_cap(ab, "new_pi", &axs->new_pcap.inheritable);
1386 			audit_log_cap(ab, "new_pe", &axs->new_pcap.effective);
1387 			break; }
1388 
1389 		}
1390 		audit_log_end(ab);
1391 	}
1392 
1393 	if (context->type)
1394 		show_special(context, &call_panic);
1395 
1396 	if (context->fds[0] >= 0) {
1397 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR);
1398 		if (ab) {
1399 			audit_log_format(ab, "fd0=%d fd1=%d",
1400 					context->fds[0], context->fds[1]);
1401 			audit_log_end(ab);
1402 		}
1403 	}
1404 
1405 	if (context->sockaddr_len) {
1406 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
1407 		if (ab) {
1408 			audit_log_format(ab, "saddr=");
1409 			audit_log_n_hex(ab, (void *)context->sockaddr,
1410 					context->sockaddr_len);
1411 			audit_log_end(ab);
1412 		}
1413 	}
1414 
1415 	for (aux = context->aux_pids; aux; aux = aux->next) {
1416 		struct audit_aux_data_pids *axs = (void *)aux;
1417 
1418 		for (i = 0; i < axs->pid_count; i++)
1419 			if (audit_log_pid_context(context, axs->target_pid[i],
1420 						  axs->target_auid[i],
1421 						  axs->target_uid[i],
1422 						  axs->target_sessionid[i],
1423 						  axs->target_sid[i],
1424 						  axs->target_comm[i]))
1425 				call_panic = 1;
1426 	}
1427 
1428 	if (context->target_pid &&
1429 	    audit_log_pid_context(context, context->target_pid,
1430 				  context->target_auid, context->target_uid,
1431 				  context->target_sessionid,
1432 				  context->target_sid, context->target_comm))
1433 			call_panic = 1;
1434 
1435 	if (context->pwd.dentry && context->pwd.mnt) {
1436 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
1437 		if (ab) {
1438 			audit_log_d_path(ab, "cwd=", &context->pwd);
1439 			audit_log_end(ab);
1440 		}
1441 	}
1442 
1443 	i = 0;
1444 	list_for_each_entry(n, &context->names_list, list) {
1445 		if (n->hidden)
1446 			continue;
1447 		audit_log_name(context, n, NULL, i++, &call_panic);
1448 	}
1449 
1450 	audit_log_proctitle(tsk, context);
1451 
1452 	/* Send end of event record to help user space know we are finished */
1453 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
1454 	if (ab)
1455 		audit_log_end(ab);
1456 	if (call_panic)
1457 		audit_panic("error converting sid to string");
1458 }
1459 
1460 /**
1461  * audit_free - free a per-task audit context
1462  * @tsk: task whose audit context block to free
1463  *
1464  * Called from copy_process and do_exit
1465  */
1466 void __audit_free(struct task_struct *tsk)
1467 {
1468 	struct audit_context *context;
1469 
1470 	context = audit_take_context(tsk, 0, 0);
1471 	if (!context)
1472 		return;
1473 
1474 	/* Check for system calls that do not go through the exit
1475 	 * function (e.g., exit_group), then free context block.
1476 	 * We use GFP_ATOMIC here because we might be doing this
1477 	 * in the context of the idle thread */
1478 	/* that can happen only if we are called from do_exit() */
1479 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1480 		audit_log_exit(context, tsk);
1481 	if (!list_empty(&context->killed_trees))
1482 		audit_kill_trees(&context->killed_trees);
1483 
1484 	audit_free_context(context);
1485 }
1486 
1487 /**
1488  * audit_syscall_entry - fill in an audit record at syscall entry
1489  * @major: major syscall type (function)
1490  * @a1: additional syscall register 1
1491  * @a2: additional syscall register 2
1492  * @a3: additional syscall register 3
1493  * @a4: additional syscall register 4
1494  *
1495  * Fill in audit context at syscall entry.  This only happens if the
1496  * audit context was created when the task was created and the state or
1497  * filters demand the audit context be built.  If the state from the
1498  * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1499  * then the record will be written at syscall exit time (otherwise, it
1500  * will only be written if another part of the kernel requests that it
1501  * be written).
1502  */
1503 void __audit_syscall_entry(int major, unsigned long a1, unsigned long a2,
1504 			   unsigned long a3, unsigned long a4)
1505 {
1506 	struct task_struct *tsk = current;
1507 	struct audit_context *context = tsk->audit_context;
1508 	enum audit_state     state;
1509 
1510 	if (!context)
1511 		return;
1512 
1513 	BUG_ON(context->in_syscall || context->name_count);
1514 
1515 	if (!audit_enabled)
1516 		return;
1517 
1518 	context->arch	    = syscall_get_arch();
1519 	context->major      = major;
1520 	context->argv[0]    = a1;
1521 	context->argv[1]    = a2;
1522 	context->argv[2]    = a3;
1523 	context->argv[3]    = a4;
1524 
1525 	state = context->state;
1526 	context->dummy = !audit_n_rules;
1527 	if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
1528 		context->prio = 0;
1529 		state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
1530 	}
1531 	if (state == AUDIT_DISABLED)
1532 		return;
1533 
1534 	context->serial     = 0;
1535 	context->ctime      = CURRENT_TIME;
1536 	context->in_syscall = 1;
1537 	context->current_state  = state;
1538 	context->ppid       = 0;
1539 }
1540 
1541 /**
1542  * audit_syscall_exit - deallocate audit context after a system call
1543  * @success: success value of the syscall
1544  * @return_code: return value of the syscall
1545  *
1546  * Tear down after system call.  If the audit context has been marked as
1547  * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1548  * filtering, or because some other part of the kernel wrote an audit
1549  * message), then write out the syscall information.  In call cases,
1550  * free the names stored from getname().
1551  */
1552 void __audit_syscall_exit(int success, long return_code)
1553 {
1554 	struct task_struct *tsk = current;
1555 	struct audit_context *context;
1556 
1557 	if (success)
1558 		success = AUDITSC_SUCCESS;
1559 	else
1560 		success = AUDITSC_FAILURE;
1561 
1562 	context = audit_take_context(tsk, success, return_code);
1563 	if (!context)
1564 		return;
1565 
1566 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1567 		audit_log_exit(context, tsk);
1568 
1569 	context->in_syscall = 0;
1570 	context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
1571 
1572 	if (!list_empty(&context->killed_trees))
1573 		audit_kill_trees(&context->killed_trees);
1574 
1575 	audit_free_names(context);
1576 	unroll_tree_refs(context, NULL, 0);
1577 	audit_free_aux(context);
1578 	context->aux = NULL;
1579 	context->aux_pids = NULL;
1580 	context->target_pid = 0;
1581 	context->target_sid = 0;
1582 	context->sockaddr_len = 0;
1583 	context->type = 0;
1584 	context->fds[0] = -1;
1585 	if (context->state != AUDIT_RECORD_CONTEXT) {
1586 		kfree(context->filterkey);
1587 		context->filterkey = NULL;
1588 	}
1589 	tsk->audit_context = context;
1590 }
1591 
1592 static inline void handle_one(const struct inode *inode)
1593 {
1594 #ifdef CONFIG_AUDIT_TREE
1595 	struct audit_context *context;
1596 	struct audit_tree_refs *p;
1597 	struct audit_chunk *chunk;
1598 	int count;
1599 	if (likely(hlist_empty(&inode->i_fsnotify_marks)))
1600 		return;
1601 	context = current->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 #endif
1620 }
1621 
1622 static void handle_path(const struct dentry *dentry)
1623 {
1624 #ifdef CONFIG_AUDIT_TREE
1625 	struct audit_context *context;
1626 	struct audit_tree_refs *p;
1627 	const struct dentry *d, *parent;
1628 	struct audit_chunk *drop;
1629 	unsigned long seq;
1630 	int count;
1631 
1632 	context = current->audit_context;
1633 	p = context->trees;
1634 	count = context->tree_count;
1635 retry:
1636 	drop = NULL;
1637 	d = dentry;
1638 	rcu_read_lock();
1639 	seq = read_seqbegin(&rename_lock);
1640 	for(;;) {
1641 		struct inode *inode = d_backing_inode(d);
1642 		if (inode && unlikely(!hlist_empty(&inode->i_fsnotify_marks))) {
1643 			struct audit_chunk *chunk;
1644 			chunk = audit_tree_lookup(inode);
1645 			if (chunk) {
1646 				if (unlikely(!put_tree_ref(context, chunk))) {
1647 					drop = chunk;
1648 					break;
1649 				}
1650 			}
1651 		}
1652 		parent = d->d_parent;
1653 		if (parent == d)
1654 			break;
1655 		d = parent;
1656 	}
1657 	if (unlikely(read_seqretry(&rename_lock, seq) || drop)) {  /* in this order */
1658 		rcu_read_unlock();
1659 		if (!drop) {
1660 			/* just a race with rename */
1661 			unroll_tree_refs(context, p, count);
1662 			goto retry;
1663 		}
1664 		audit_put_chunk(drop);
1665 		if (grow_tree_refs(context)) {
1666 			/* OK, got more space */
1667 			unroll_tree_refs(context, p, count);
1668 			goto retry;
1669 		}
1670 		/* too bad */
1671 		pr_warn("out of memory, audit has lost a tree reference\n");
1672 		unroll_tree_refs(context, p, count);
1673 		audit_set_auditable(context);
1674 		return;
1675 	}
1676 	rcu_read_unlock();
1677 #endif
1678 }
1679 
1680 static struct audit_names *audit_alloc_name(struct audit_context *context,
1681 						unsigned char type)
1682 {
1683 	struct audit_names *aname;
1684 
1685 	if (context->name_count < AUDIT_NAMES) {
1686 		aname = &context->preallocated_names[context->name_count];
1687 		memset(aname, 0, sizeof(*aname));
1688 	} else {
1689 		aname = kzalloc(sizeof(*aname), GFP_NOFS);
1690 		if (!aname)
1691 			return NULL;
1692 		aname->should_free = true;
1693 	}
1694 
1695 	aname->ino = AUDIT_INO_UNSET;
1696 	aname->type = type;
1697 	list_add_tail(&aname->list, &context->names_list);
1698 
1699 	context->name_count++;
1700 	return aname;
1701 }
1702 
1703 /**
1704  * audit_reusename - fill out filename with info from existing entry
1705  * @uptr: userland ptr to pathname
1706  *
1707  * Search the audit_names list for the current audit context. If there is an
1708  * existing entry with a matching "uptr" then return the filename
1709  * associated with that audit_name. If not, return NULL.
1710  */
1711 struct filename *
1712 __audit_reusename(const __user char *uptr)
1713 {
1714 	struct audit_context *context = current->audit_context;
1715 	struct audit_names *n;
1716 
1717 	list_for_each_entry(n, &context->names_list, list) {
1718 		if (!n->name)
1719 			continue;
1720 		if (n->name->uptr == uptr) {
1721 			n->name->refcnt++;
1722 			return n->name;
1723 		}
1724 	}
1725 	return NULL;
1726 }
1727 
1728 /**
1729  * audit_getname - add a name to the list
1730  * @name: name to add
1731  *
1732  * Add a name to the list of audit names for this context.
1733  * Called from fs/namei.c:getname().
1734  */
1735 void __audit_getname(struct filename *name)
1736 {
1737 	struct audit_context *context = current->audit_context;
1738 	struct audit_names *n;
1739 
1740 	if (!context->in_syscall)
1741 		return;
1742 
1743 	n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1744 	if (!n)
1745 		return;
1746 
1747 	n->name = name;
1748 	n->name_len = AUDIT_NAME_FULL;
1749 	name->aname = n;
1750 	name->refcnt++;
1751 
1752 	if (!context->pwd.dentry)
1753 		get_fs_pwd(current->fs, &context->pwd);
1754 }
1755 
1756 /**
1757  * __audit_inode - store the inode and device from a lookup
1758  * @name: name being audited
1759  * @dentry: dentry being audited
1760  * @flags: attributes for this particular entry
1761  */
1762 void __audit_inode(struct filename *name, const struct dentry *dentry,
1763 		   unsigned int flags)
1764 {
1765 	struct audit_context *context = current->audit_context;
1766 	struct inode *inode = d_backing_inode(dentry);
1767 	struct audit_names *n;
1768 	bool parent = flags & AUDIT_INODE_PARENT;
1769 
1770 	if (!context->in_syscall)
1771 		return;
1772 
1773 	if (!name)
1774 		goto out_alloc;
1775 
1776 	/*
1777 	 * If we have a pointer to an audit_names entry already, then we can
1778 	 * just use it directly if the type is correct.
1779 	 */
1780 	n = name->aname;
1781 	if (n) {
1782 		if (parent) {
1783 			if (n->type == AUDIT_TYPE_PARENT ||
1784 			    n->type == AUDIT_TYPE_UNKNOWN)
1785 				goto out;
1786 		} else {
1787 			if (n->type != AUDIT_TYPE_PARENT)
1788 				goto out;
1789 		}
1790 	}
1791 
1792 	list_for_each_entry_reverse(n, &context->names_list, list) {
1793 		if (n->ino) {
1794 			/* valid inode number, use that for the comparison */
1795 			if (n->ino != inode->i_ino ||
1796 			    n->dev != inode->i_sb->s_dev)
1797 				continue;
1798 		} else if (n->name) {
1799 			/* inode number has not been set, check the name */
1800 			if (strcmp(n->name->name, name->name))
1801 				continue;
1802 		} else
1803 			/* no inode and no name (?!) ... this is odd ... */
1804 			continue;
1805 
1806 		/* match the correct record type */
1807 		if (parent) {
1808 			if (n->type == AUDIT_TYPE_PARENT ||
1809 			    n->type == AUDIT_TYPE_UNKNOWN)
1810 				goto out;
1811 		} else {
1812 			if (n->type != AUDIT_TYPE_PARENT)
1813 				goto out;
1814 		}
1815 	}
1816 
1817 out_alloc:
1818 	/* unable to find an entry with both a matching name and type */
1819 	n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
1820 	if (!n)
1821 		return;
1822 	if (name) {
1823 		n->name = name;
1824 		name->refcnt++;
1825 	}
1826 
1827 out:
1828 	if (parent) {
1829 		n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL;
1830 		n->type = AUDIT_TYPE_PARENT;
1831 		if (flags & AUDIT_INODE_HIDDEN)
1832 			n->hidden = true;
1833 	} else {
1834 		n->name_len = AUDIT_NAME_FULL;
1835 		n->type = AUDIT_TYPE_NORMAL;
1836 	}
1837 	handle_path(dentry);
1838 	audit_copy_inode(n, dentry, inode);
1839 }
1840 
1841 void __audit_file(const struct file *file)
1842 {
1843 	__audit_inode(NULL, file->f_path.dentry, 0);
1844 }
1845 
1846 /**
1847  * __audit_inode_child - collect inode info for created/removed objects
1848  * @parent: inode of dentry parent
1849  * @dentry: dentry being audited
1850  * @type:   AUDIT_TYPE_* value that we're looking for
1851  *
1852  * For syscalls that create or remove filesystem objects, audit_inode
1853  * can only collect information for the filesystem object's parent.
1854  * This call updates the audit context with the child's information.
1855  * Syscalls that create a new filesystem object must be hooked after
1856  * the object is created.  Syscalls that remove a filesystem object
1857  * must be hooked prior, in order to capture the target inode during
1858  * unsuccessful attempts.
1859  */
1860 void __audit_inode_child(struct inode *parent,
1861 			 const struct dentry *dentry,
1862 			 const unsigned char type)
1863 {
1864 	struct audit_context *context = current->audit_context;
1865 	struct inode *inode = d_backing_inode(dentry);
1866 	const char *dname = dentry->d_name.name;
1867 	struct audit_names *n, *found_parent = NULL, *found_child = NULL;
1868 
1869 	if (!context->in_syscall)
1870 		return;
1871 
1872 	if (inode)
1873 		handle_one(inode);
1874 
1875 	/* look for a parent entry first */
1876 	list_for_each_entry(n, &context->names_list, list) {
1877 		if (!n->name ||
1878 		    (n->type != AUDIT_TYPE_PARENT &&
1879 		     n->type != AUDIT_TYPE_UNKNOWN))
1880 			continue;
1881 
1882 		if (n->ino == parent->i_ino && n->dev == parent->i_sb->s_dev &&
1883 		    !audit_compare_dname_path(dname,
1884 					      n->name->name, n->name_len)) {
1885 			if (n->type == AUDIT_TYPE_UNKNOWN)
1886 				n->type = AUDIT_TYPE_PARENT;
1887 			found_parent = n;
1888 			break;
1889 		}
1890 	}
1891 
1892 	/* is there a matching child entry? */
1893 	list_for_each_entry(n, &context->names_list, list) {
1894 		/* can only match entries that have a name */
1895 		if (!n->name ||
1896 		    (n->type != type && n->type != AUDIT_TYPE_UNKNOWN))
1897 			continue;
1898 
1899 		if (!strcmp(dname, n->name->name) ||
1900 		    !audit_compare_dname_path(dname, n->name->name,
1901 						found_parent ?
1902 						found_parent->name_len :
1903 						AUDIT_NAME_FULL)) {
1904 			if (n->type == AUDIT_TYPE_UNKNOWN)
1905 				n->type = type;
1906 			found_child = n;
1907 			break;
1908 		}
1909 	}
1910 
1911 	if (!found_parent) {
1912 		/* create a new, "anonymous" parent record */
1913 		n = audit_alloc_name(context, AUDIT_TYPE_PARENT);
1914 		if (!n)
1915 			return;
1916 		audit_copy_inode(n, NULL, parent);
1917 	}
1918 
1919 	if (!found_child) {
1920 		found_child = audit_alloc_name(context, type);
1921 		if (!found_child)
1922 			return;
1923 
1924 		/* Re-use the name belonging to the slot for a matching parent
1925 		 * directory. All names for this context are relinquished in
1926 		 * audit_free_names() */
1927 		if (found_parent) {
1928 			found_child->name = found_parent->name;
1929 			found_child->name_len = AUDIT_NAME_FULL;
1930 			found_child->name->refcnt++;
1931 		}
1932 	}
1933 
1934 	if (inode)
1935 		audit_copy_inode(found_child, dentry, inode);
1936 	else
1937 		found_child->ino = AUDIT_INO_UNSET;
1938 }
1939 EXPORT_SYMBOL_GPL(__audit_inode_child);
1940 
1941 /**
1942  * auditsc_get_stamp - get local copies of audit_context values
1943  * @ctx: audit_context for the task
1944  * @t: timespec to store time recorded in the audit_context
1945  * @serial: serial value that is recorded in the audit_context
1946  *
1947  * Also sets the context as auditable.
1948  */
1949 int auditsc_get_stamp(struct audit_context *ctx,
1950 		       struct timespec *t, unsigned int *serial)
1951 {
1952 	if (!ctx->in_syscall)
1953 		return 0;
1954 	if (!ctx->serial)
1955 		ctx->serial = audit_serial();
1956 	t->tv_sec  = ctx->ctime.tv_sec;
1957 	t->tv_nsec = ctx->ctime.tv_nsec;
1958 	*serial    = ctx->serial;
1959 	if (!ctx->prio) {
1960 		ctx->prio = 1;
1961 		ctx->current_state = AUDIT_RECORD_CONTEXT;
1962 	}
1963 	return 1;
1964 }
1965 
1966 /* global counter which is incremented every time something logs in */
1967 static atomic_t session_id = ATOMIC_INIT(0);
1968 
1969 static int audit_set_loginuid_perm(kuid_t loginuid)
1970 {
1971 	/* if we are unset, we don't need privs */
1972 	if (!audit_loginuid_set(current))
1973 		return 0;
1974 	/* if AUDIT_FEATURE_LOGINUID_IMMUTABLE means never ever allow a change*/
1975 	if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
1976 		return -EPERM;
1977 	/* it is set, you need permission */
1978 	if (!capable(CAP_AUDIT_CONTROL))
1979 		return -EPERM;
1980 	/* reject if this is not an unset and we don't allow that */
1981 	if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID) && uid_valid(loginuid))
1982 		return -EPERM;
1983 	return 0;
1984 }
1985 
1986 static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
1987 				   unsigned int oldsessionid, unsigned int sessionid,
1988 				   int rc)
1989 {
1990 	struct audit_buffer *ab;
1991 	uid_t uid, oldloginuid, loginuid;
1992 	struct tty_struct *tty;
1993 
1994 	if (!audit_enabled)
1995 		return;
1996 
1997 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
1998 	if (!ab)
1999 		return;
2000 
2001 	uid = from_kuid(&init_user_ns, task_uid(current));
2002 	oldloginuid = from_kuid(&init_user_ns, koldloginuid);
2003 	loginuid = from_kuid(&init_user_ns, kloginuid),
2004 	tty = audit_get_tty(current);
2005 
2006 	audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
2007 	audit_log_task_context(ab);
2008 	audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
2009 			 oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
2010 			 oldsessionid, sessionid, !rc);
2011 	audit_put_tty(tty);
2012 	audit_log_end(ab);
2013 }
2014 
2015 /**
2016  * audit_set_loginuid - set current task's audit_context loginuid
2017  * @loginuid: loginuid value
2018  *
2019  * Returns 0.
2020  *
2021  * Called (set) from fs/proc/base.c::proc_loginuid_write().
2022  */
2023 int audit_set_loginuid(kuid_t loginuid)
2024 {
2025 	struct task_struct *task = current;
2026 	unsigned int oldsessionid, sessionid = (unsigned int)-1;
2027 	kuid_t oldloginuid;
2028 	int rc;
2029 
2030 	oldloginuid = audit_get_loginuid(current);
2031 	oldsessionid = audit_get_sessionid(current);
2032 
2033 	rc = audit_set_loginuid_perm(loginuid);
2034 	if (rc)
2035 		goto out;
2036 
2037 	/* are we setting or clearing? */
2038 	if (uid_valid(loginuid)) {
2039 		sessionid = (unsigned int)atomic_inc_return(&session_id);
2040 		if (unlikely(sessionid == (unsigned int)-1))
2041 			sessionid = (unsigned int)atomic_inc_return(&session_id);
2042 	}
2043 
2044 	task->sessionid = sessionid;
2045 	task->loginuid = loginuid;
2046 out:
2047 	audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
2048 	return rc;
2049 }
2050 
2051 /**
2052  * __audit_mq_open - record audit data for a POSIX MQ open
2053  * @oflag: open flag
2054  * @mode: mode bits
2055  * @attr: queue attributes
2056  *
2057  */
2058 void __audit_mq_open(int oflag, umode_t mode, struct mq_attr *attr)
2059 {
2060 	struct audit_context *context = current->audit_context;
2061 
2062 	if (attr)
2063 		memcpy(&context->mq_open.attr, attr, sizeof(struct mq_attr));
2064 	else
2065 		memset(&context->mq_open.attr, 0, sizeof(struct mq_attr));
2066 
2067 	context->mq_open.oflag = oflag;
2068 	context->mq_open.mode = mode;
2069 
2070 	context->type = AUDIT_MQ_OPEN;
2071 }
2072 
2073 /**
2074  * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive
2075  * @mqdes: MQ descriptor
2076  * @msg_len: Message length
2077  * @msg_prio: Message priority
2078  * @abs_timeout: Message timeout in absolute time
2079  *
2080  */
2081 void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
2082 			const struct timespec *abs_timeout)
2083 {
2084 	struct audit_context *context = current->audit_context;
2085 	struct timespec *p = &context->mq_sendrecv.abs_timeout;
2086 
2087 	if (abs_timeout)
2088 		memcpy(p, abs_timeout, sizeof(struct timespec));
2089 	else
2090 		memset(p, 0, sizeof(struct timespec));
2091 
2092 	context->mq_sendrecv.mqdes = mqdes;
2093 	context->mq_sendrecv.msg_len = msg_len;
2094 	context->mq_sendrecv.msg_prio = msg_prio;
2095 
2096 	context->type = AUDIT_MQ_SENDRECV;
2097 }
2098 
2099 /**
2100  * __audit_mq_notify - record audit data for a POSIX MQ notify
2101  * @mqdes: MQ descriptor
2102  * @notification: Notification event
2103  *
2104  */
2105 
2106 void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
2107 {
2108 	struct audit_context *context = current->audit_context;
2109 
2110 	if (notification)
2111 		context->mq_notify.sigev_signo = notification->sigev_signo;
2112 	else
2113 		context->mq_notify.sigev_signo = 0;
2114 
2115 	context->mq_notify.mqdes = mqdes;
2116 	context->type = AUDIT_MQ_NOTIFY;
2117 }
2118 
2119 /**
2120  * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
2121  * @mqdes: MQ descriptor
2122  * @mqstat: MQ flags
2123  *
2124  */
2125 void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
2126 {
2127 	struct audit_context *context = current->audit_context;
2128 	context->mq_getsetattr.mqdes = mqdes;
2129 	context->mq_getsetattr.mqstat = *mqstat;
2130 	context->type = AUDIT_MQ_GETSETATTR;
2131 }
2132 
2133 /**
2134  * audit_ipc_obj - record audit data for ipc object
2135  * @ipcp: ipc permissions
2136  *
2137  */
2138 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
2139 {
2140 	struct audit_context *context = current->audit_context;
2141 	context->ipc.uid = ipcp->uid;
2142 	context->ipc.gid = ipcp->gid;
2143 	context->ipc.mode = ipcp->mode;
2144 	context->ipc.has_perm = 0;
2145 	security_ipc_getsecid(ipcp, &context->ipc.osid);
2146 	context->type = AUDIT_IPC;
2147 }
2148 
2149 /**
2150  * audit_ipc_set_perm - record audit data for new ipc permissions
2151  * @qbytes: msgq bytes
2152  * @uid: msgq user id
2153  * @gid: msgq group id
2154  * @mode: msgq mode (permissions)
2155  *
2156  * Called only after audit_ipc_obj().
2157  */
2158 void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode)
2159 {
2160 	struct audit_context *context = current->audit_context;
2161 
2162 	context->ipc.qbytes = qbytes;
2163 	context->ipc.perm_uid = uid;
2164 	context->ipc.perm_gid = gid;
2165 	context->ipc.perm_mode = mode;
2166 	context->ipc.has_perm = 1;
2167 }
2168 
2169 void __audit_bprm(struct linux_binprm *bprm)
2170 {
2171 	struct audit_context *context = current->audit_context;
2172 
2173 	context->type = AUDIT_EXECVE;
2174 	context->execve.argc = bprm->argc;
2175 }
2176 
2177 
2178 /**
2179  * audit_socketcall - record audit data for sys_socketcall
2180  * @nargs: number of args, which should not be more than AUDITSC_ARGS.
2181  * @args: args array
2182  *
2183  */
2184 int __audit_socketcall(int nargs, unsigned long *args)
2185 {
2186 	struct audit_context *context = current->audit_context;
2187 
2188 	if (nargs <= 0 || nargs > AUDITSC_ARGS || !args)
2189 		return -EINVAL;
2190 	context->type = AUDIT_SOCKETCALL;
2191 	context->socketcall.nargs = nargs;
2192 	memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long));
2193 	return 0;
2194 }
2195 
2196 /**
2197  * __audit_fd_pair - record audit data for pipe and socketpair
2198  * @fd1: the first file descriptor
2199  * @fd2: the second file descriptor
2200  *
2201  */
2202 void __audit_fd_pair(int fd1, int fd2)
2203 {
2204 	struct audit_context *context = current->audit_context;
2205 	context->fds[0] = fd1;
2206 	context->fds[1] = fd2;
2207 }
2208 
2209 /**
2210  * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
2211  * @len: data length in user space
2212  * @a: data address in kernel space
2213  *
2214  * Returns 0 for success or NULL context or < 0 on error.
2215  */
2216 int __audit_sockaddr(int len, void *a)
2217 {
2218 	struct audit_context *context = current->audit_context;
2219 
2220 	if (!context->sockaddr) {
2221 		void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL);
2222 		if (!p)
2223 			return -ENOMEM;
2224 		context->sockaddr = p;
2225 	}
2226 
2227 	context->sockaddr_len = len;
2228 	memcpy(context->sockaddr, a, len);
2229 	return 0;
2230 }
2231 
2232 void __audit_ptrace(struct task_struct *t)
2233 {
2234 	struct audit_context *context = current->audit_context;
2235 
2236 	context->target_pid = task_tgid_nr(t);
2237 	context->target_auid = audit_get_loginuid(t);
2238 	context->target_uid = task_uid(t);
2239 	context->target_sessionid = audit_get_sessionid(t);
2240 	security_task_getsecid(t, &context->target_sid);
2241 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
2242 }
2243 
2244 /**
2245  * audit_signal_info - record signal info for shutting down audit subsystem
2246  * @sig: signal value
2247  * @t: task being signaled
2248  *
2249  * If the audit subsystem is being terminated, record the task (pid)
2250  * and uid that is doing that.
2251  */
2252 int __audit_signal_info(int sig, struct task_struct *t)
2253 {
2254 	struct audit_aux_data_pids *axp;
2255 	struct task_struct *tsk = current;
2256 	struct audit_context *ctx = tsk->audit_context;
2257 	kuid_t uid = current_uid(), t_uid = task_uid(t);
2258 
2259 	if (audit_pid && t->tgid == audit_pid) {
2260 		if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) {
2261 			audit_sig_pid = task_tgid_nr(tsk);
2262 			if (uid_valid(tsk->loginuid))
2263 				audit_sig_uid = tsk->loginuid;
2264 			else
2265 				audit_sig_uid = uid;
2266 			security_task_getsecid(tsk, &audit_sig_sid);
2267 		}
2268 		if (!audit_signals || audit_dummy_context())
2269 			return 0;
2270 	}
2271 
2272 	/* optimize the common case by putting first signal recipient directly
2273 	 * in audit_context */
2274 	if (!ctx->target_pid) {
2275 		ctx->target_pid = task_tgid_nr(t);
2276 		ctx->target_auid = audit_get_loginuid(t);
2277 		ctx->target_uid = t_uid;
2278 		ctx->target_sessionid = audit_get_sessionid(t);
2279 		security_task_getsecid(t, &ctx->target_sid);
2280 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
2281 		return 0;
2282 	}
2283 
2284 	axp = (void *)ctx->aux_pids;
2285 	if (!axp || axp->pid_count == AUDIT_AUX_PIDS) {
2286 		axp = kzalloc(sizeof(*axp), GFP_ATOMIC);
2287 		if (!axp)
2288 			return -ENOMEM;
2289 
2290 		axp->d.type = AUDIT_OBJ_PID;
2291 		axp->d.next = ctx->aux_pids;
2292 		ctx->aux_pids = (void *)axp;
2293 	}
2294 	BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);
2295 
2296 	axp->target_pid[axp->pid_count] = task_tgid_nr(t);
2297 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
2298 	axp->target_uid[axp->pid_count] = t_uid;
2299 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
2300 	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
2301 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
2302 	axp->pid_count++;
2303 
2304 	return 0;
2305 }
2306 
2307 /**
2308  * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps
2309  * @bprm: pointer to the bprm being processed
2310  * @new: the proposed new credentials
2311  * @old: the old credentials
2312  *
2313  * Simply check if the proc already has the caps given by the file and if not
2314  * store the priv escalation info for later auditing at the end of the syscall
2315  *
2316  * -Eric
2317  */
2318 int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
2319 			   const struct cred *new, const struct cred *old)
2320 {
2321 	struct audit_aux_data_bprm_fcaps *ax;
2322 	struct audit_context *context = current->audit_context;
2323 	struct cpu_vfs_cap_data vcaps;
2324 
2325 	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2326 	if (!ax)
2327 		return -ENOMEM;
2328 
2329 	ax->d.type = AUDIT_BPRM_FCAPS;
2330 	ax->d.next = context->aux;
2331 	context->aux = (void *)ax;
2332 
2333 	get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps);
2334 
2335 	ax->fcap.permitted = vcaps.permitted;
2336 	ax->fcap.inheritable = vcaps.inheritable;
2337 	ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2338 	ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
2339 
2340 	ax->old_pcap.permitted   = old->cap_permitted;
2341 	ax->old_pcap.inheritable = old->cap_inheritable;
2342 	ax->old_pcap.effective   = old->cap_effective;
2343 
2344 	ax->new_pcap.permitted   = new->cap_permitted;
2345 	ax->new_pcap.inheritable = new->cap_inheritable;
2346 	ax->new_pcap.effective   = new->cap_effective;
2347 	return 0;
2348 }
2349 
2350 /**
2351  * __audit_log_capset - store information about the arguments to the capset syscall
2352  * @new: the new credentials
2353  * @old: the old (current) credentials
2354  *
2355  * Record the arguments userspace sent to sys_capset for later printing by the
2356  * audit system if applicable
2357  */
2358 void __audit_log_capset(const struct cred *new, const struct cred *old)
2359 {
2360 	struct audit_context *context = current->audit_context;
2361 	context->capset.pid = task_tgid_nr(current);
2362 	context->capset.cap.effective   = new->cap_effective;
2363 	context->capset.cap.inheritable = new->cap_effective;
2364 	context->capset.cap.permitted   = new->cap_permitted;
2365 	context->type = AUDIT_CAPSET;
2366 }
2367 
2368 void __audit_mmap_fd(int fd, int flags)
2369 {
2370 	struct audit_context *context = current->audit_context;
2371 	context->mmap.fd = fd;
2372 	context->mmap.flags = flags;
2373 	context->type = AUDIT_MMAP;
2374 }
2375 
2376 void __audit_log_kern_module(char *name)
2377 {
2378 	struct audit_context *context = current->audit_context;
2379 
2380 	context->module.name = kmalloc(strlen(name) + 1, GFP_KERNEL);
2381 	strcpy(context->module.name, name);
2382 	context->type = AUDIT_KERN_MODULE;
2383 }
2384 
2385 static void audit_log_task(struct audit_buffer *ab)
2386 {
2387 	kuid_t auid, uid;
2388 	kgid_t gid;
2389 	unsigned int sessionid;
2390 	char comm[sizeof(current->comm)];
2391 
2392 	auid = audit_get_loginuid(current);
2393 	sessionid = audit_get_sessionid(current);
2394 	current_uid_gid(&uid, &gid);
2395 
2396 	audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
2397 			 from_kuid(&init_user_ns, auid),
2398 			 from_kuid(&init_user_ns, uid),
2399 			 from_kgid(&init_user_ns, gid),
2400 			 sessionid);
2401 	audit_log_task_context(ab);
2402 	audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
2403 	audit_log_untrustedstring(ab, get_task_comm(comm, current));
2404 	audit_log_d_path_exe(ab, current->mm);
2405 }
2406 
2407 /**
2408  * audit_core_dumps - record information about processes that end abnormally
2409  * @signr: signal value
2410  *
2411  * If a process ends with a core dump, something fishy is going on and we
2412  * should record the event for investigation.
2413  */
2414 void audit_core_dumps(long signr)
2415 {
2416 	struct audit_buffer *ab;
2417 
2418 	if (!audit_enabled)
2419 		return;
2420 
2421 	if (signr == SIGQUIT)	/* don't care for those */
2422 		return;
2423 
2424 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
2425 	if (unlikely(!ab))
2426 		return;
2427 	audit_log_task(ab);
2428 	audit_log_format(ab, " sig=%ld res=1", signr);
2429 	audit_log_end(ab);
2430 }
2431 
2432 void __audit_seccomp(unsigned long syscall, long signr, int code)
2433 {
2434 	struct audit_buffer *ab;
2435 
2436 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
2437 	if (unlikely(!ab))
2438 		return;
2439 	audit_log_task(ab);
2440 	audit_log_format(ab, " sig=%ld arch=%x syscall=%ld compat=%d ip=0x%lx code=0x%x",
2441 			 signr, syscall_get_arch(), syscall,
2442 			 in_compat_syscall(), KSTK_EIP(current), code);
2443 	audit_log_end(ab);
2444 }
2445 
2446 struct list_head *audit_killed_trees(void)
2447 {
2448 	struct audit_context *ctx = current->audit_context;
2449 	if (likely(!ctx || !ctx->in_syscall))
2450 		return NULL;
2451 	return &ctx->killed_trees;
2452 }
2453