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