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 #include <linux/init.h>
46 #include <asm/types.h>
47 #include <linux/atomic.h>
48 #include <linux/fs.h>
49 #include <linux/namei.h>
50 #include <linux/mm.h>
51 #include <linux/export.h>
52 #include <linux/slab.h>
53 #include <linux/mount.h>
54 #include <linux/socket.h>
55 #include <linux/mqueue.h>
56 #include <linux/audit.h>
57 #include <linux/personality.h>
58 #include <linux/time.h>
59 #include <linux/netlink.h>
60 #include <linux/compiler.h>
61 #include <asm/unistd.h>
62 #include <linux/security.h>
63 #include <linux/list.h>
64 #include <linux/tty.h>
65 #include <linux/binfmts.h>
66 #include <linux/highmem.h>
67 #include <linux/syscalls.h>
68 #include <linux/capability.h>
69 #include <linux/fs_struct.h>
70 
71 #include "audit.h"
72 
73 /* flags stating the success for a syscall */
74 #define AUDITSC_INVALID 0
75 #define AUDITSC_SUCCESS 1
76 #define AUDITSC_FAILURE 2
77 
78 /* AUDIT_NAMES is the number of slots we reserve in the audit_context
79  * for saving names from getname().  If we get more names we will allocate
80  * a name dynamically and also add those to the list anchored by names_list. */
81 #define AUDIT_NAMES	5
82 
83 /* Indicates that audit should log the full pathname. */
84 #define AUDIT_NAME_FULL -1
85 
86 /* no execve audit message should be longer than this (userspace limits) */
87 #define MAX_EXECVE_AUDIT_LEN 7500
88 
89 /* number of audit rules */
90 int audit_n_rules;
91 
92 /* determines whether we collect data for signals sent */
93 int audit_signals;
94 
95 struct audit_cap_data {
96 	kernel_cap_t		permitted;
97 	kernel_cap_t		inheritable;
98 	union {
99 		unsigned int	fE;		/* effective bit of a file capability */
100 		kernel_cap_t	effective;	/* effective set of a process */
101 	};
102 };
103 
104 /* When fs/namei.c:getname() is called, we store the pointer in name and
105  * we don't let putname() free it (instead we free all of the saved
106  * pointers at syscall exit time).
107  *
108  * Further, in fs/namei.c:path_lookup() we store the inode and device. */
109 struct audit_names {
110 	struct list_head list;		/* audit_context->names_list */
111 	const char	*name;
112 	unsigned long	ino;
113 	dev_t		dev;
114 	umode_t		mode;
115 	uid_t		uid;
116 	gid_t		gid;
117 	dev_t		rdev;
118 	u32		osid;
119 	struct audit_cap_data fcap;
120 	unsigned int	fcap_ver;
121 	int		name_len;	/* number of name's characters to log */
122 	bool		name_put;	/* call __putname() for this name */
123 	/*
124 	 * This was an allocated audit_names and not from the array of
125 	 * names allocated in the task audit context.  Thus this name
126 	 * should be freed on syscall exit
127 	 */
128 	bool		should_free;
129 };
130 
131 struct audit_aux_data {
132 	struct audit_aux_data	*next;
133 	int			type;
134 };
135 
136 #define AUDIT_AUX_IPCPERM	0
137 
138 /* Number of target pids per aux struct. */
139 #define AUDIT_AUX_PIDS	16
140 
141 struct audit_aux_data_execve {
142 	struct audit_aux_data	d;
143 	int argc;
144 	int envc;
145 	struct mm_struct *mm;
146 };
147 
148 struct audit_aux_data_pids {
149 	struct audit_aux_data	d;
150 	pid_t			target_pid[AUDIT_AUX_PIDS];
151 	uid_t			target_auid[AUDIT_AUX_PIDS];
152 	uid_t			target_uid[AUDIT_AUX_PIDS];
153 	unsigned int		target_sessionid[AUDIT_AUX_PIDS];
154 	u32			target_sid[AUDIT_AUX_PIDS];
155 	char 			target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
156 	int			pid_count;
157 };
158 
159 struct audit_aux_data_bprm_fcaps {
160 	struct audit_aux_data	d;
161 	struct audit_cap_data	fcap;
162 	unsigned int		fcap_ver;
163 	struct audit_cap_data	old_pcap;
164 	struct audit_cap_data	new_pcap;
165 };
166 
167 struct audit_aux_data_capset {
168 	struct audit_aux_data	d;
169 	pid_t			pid;
170 	struct audit_cap_data	cap;
171 };
172 
173 struct audit_tree_refs {
174 	struct audit_tree_refs *next;
175 	struct audit_chunk *c[31];
176 };
177 
178 /* The per-task audit context. */
179 struct audit_context {
180 	int		    dummy;	/* must be the first element */
181 	int		    in_syscall;	/* 1 if task is in a syscall */
182 	enum audit_state    state, current_state;
183 	unsigned int	    serial;     /* serial number for record */
184 	int		    major;      /* syscall number */
185 	struct timespec	    ctime;      /* time of syscall entry */
186 	unsigned long	    argv[4];    /* syscall arguments */
187 	long		    return_code;/* syscall return code */
188 	u64		    prio;
189 	int		    return_valid; /* return code is valid */
190 	/*
191 	 * The names_list is the list of all audit_names collected during this
192 	 * syscall.  The first AUDIT_NAMES entries in the names_list will
193 	 * actually be from the preallocated_names array for performance
194 	 * reasons.  Except during allocation they should never be referenced
195 	 * through the preallocated_names array and should only be found/used
196 	 * by running the names_list.
197 	 */
198 	struct audit_names  preallocated_names[AUDIT_NAMES];
199 	int		    name_count; /* total records in names_list */
200 	struct list_head    names_list;	/* anchor for struct audit_names->list */
201 	char *		    filterkey;	/* key for rule that triggered record */
202 	struct path	    pwd;
203 	struct audit_context *previous; /* For nested syscalls */
204 	struct audit_aux_data *aux;
205 	struct audit_aux_data *aux_pids;
206 	struct sockaddr_storage *sockaddr;
207 	size_t sockaddr_len;
208 				/* Save things to print about task_struct */
209 	pid_t		    pid, ppid;
210 	uid_t		    uid, euid, suid, fsuid;
211 	gid_t		    gid, egid, sgid, fsgid;
212 	unsigned long	    personality;
213 	int		    arch;
214 
215 	pid_t		    target_pid;
216 	uid_t		    target_auid;
217 	uid_t		    target_uid;
218 	unsigned int	    target_sessionid;
219 	u32		    target_sid;
220 	char		    target_comm[TASK_COMM_LEN];
221 
222 	struct audit_tree_refs *trees, *first_trees;
223 	struct list_head killed_trees;
224 	int tree_count;
225 
226 	int type;
227 	union {
228 		struct {
229 			int nargs;
230 			long args[6];
231 		} socketcall;
232 		struct {
233 			uid_t			uid;
234 			gid_t			gid;
235 			umode_t			mode;
236 			u32			osid;
237 			int			has_perm;
238 			uid_t			perm_uid;
239 			gid_t			perm_gid;
240 			umode_t			perm_mode;
241 			unsigned long		qbytes;
242 		} ipc;
243 		struct {
244 			mqd_t			mqdes;
245 			struct mq_attr 		mqstat;
246 		} mq_getsetattr;
247 		struct {
248 			mqd_t			mqdes;
249 			int			sigev_signo;
250 		} mq_notify;
251 		struct {
252 			mqd_t			mqdes;
253 			size_t			msg_len;
254 			unsigned int		msg_prio;
255 			struct timespec		abs_timeout;
256 		} mq_sendrecv;
257 		struct {
258 			int			oflag;
259 			umode_t			mode;
260 			struct mq_attr		attr;
261 		} mq_open;
262 		struct {
263 			pid_t			pid;
264 			struct audit_cap_data	cap;
265 		} capset;
266 		struct {
267 			int			fd;
268 			int			flags;
269 		} mmap;
270 	};
271 	int fds[2];
272 
273 #if AUDIT_DEBUG
274 	int		    put_count;
275 	int		    ino_count;
276 #endif
277 };
278 
open_arg(int flags,int mask)279 static inline int open_arg(int flags, int mask)
280 {
281 	int n = ACC_MODE(flags);
282 	if (flags & (O_TRUNC | O_CREAT))
283 		n |= AUDIT_PERM_WRITE;
284 	return n & mask;
285 }
286 
audit_match_perm(struct audit_context * ctx,int mask)287 static int audit_match_perm(struct audit_context *ctx, int mask)
288 {
289 	unsigned n;
290 	if (unlikely(!ctx))
291 		return 0;
292 	n = ctx->major;
293 
294 	switch (audit_classify_syscall(ctx->arch, n)) {
295 	case 0:	/* native */
296 		if ((mask & AUDIT_PERM_WRITE) &&
297 		     audit_match_class(AUDIT_CLASS_WRITE, n))
298 			return 1;
299 		if ((mask & AUDIT_PERM_READ) &&
300 		     audit_match_class(AUDIT_CLASS_READ, n))
301 			return 1;
302 		if ((mask & AUDIT_PERM_ATTR) &&
303 		     audit_match_class(AUDIT_CLASS_CHATTR, n))
304 			return 1;
305 		return 0;
306 	case 1: /* 32bit on biarch */
307 		if ((mask & AUDIT_PERM_WRITE) &&
308 		     audit_match_class(AUDIT_CLASS_WRITE_32, n))
309 			return 1;
310 		if ((mask & AUDIT_PERM_READ) &&
311 		     audit_match_class(AUDIT_CLASS_READ_32, n))
312 			return 1;
313 		if ((mask & AUDIT_PERM_ATTR) &&
314 		     audit_match_class(AUDIT_CLASS_CHATTR_32, n))
315 			return 1;
316 		return 0;
317 	case 2: /* open */
318 		return mask & ACC_MODE(ctx->argv[1]);
319 	case 3: /* openat */
320 		return mask & ACC_MODE(ctx->argv[2]);
321 	case 4: /* socketcall */
322 		return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND);
323 	case 5: /* execve */
324 		return mask & AUDIT_PERM_EXEC;
325 	default:
326 		return 0;
327 	}
328 }
329 
audit_match_filetype(struct audit_context * ctx,int val)330 static int audit_match_filetype(struct audit_context *ctx, int val)
331 {
332 	struct audit_names *n;
333 	umode_t mode = (umode_t)val;
334 
335 	if (unlikely(!ctx))
336 		return 0;
337 
338 	list_for_each_entry(n, &ctx->names_list, list) {
339 		if ((n->ino != -1) &&
340 		    ((n->mode & S_IFMT) == mode))
341 			return 1;
342 	}
343 
344 	return 0;
345 }
346 
347 /*
348  * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
349  * ->first_trees points to its beginning, ->trees - to the current end of data.
350  * ->tree_count is the number of free entries in array pointed to by ->trees.
351  * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
352  * "empty" becomes (p, p, 31) afterwards.  We don't shrink the list (and seriously,
353  * it's going to remain 1-element for almost any setup) until we free context itself.
354  * References in it _are_ dropped - at the same time we free/drop aux stuff.
355  */
356 
357 #ifdef CONFIG_AUDIT_TREE
audit_set_auditable(struct audit_context * ctx)358 static void audit_set_auditable(struct audit_context *ctx)
359 {
360 	if (!ctx->prio) {
361 		ctx->prio = 1;
362 		ctx->current_state = AUDIT_RECORD_CONTEXT;
363 	}
364 }
365 
put_tree_ref(struct audit_context * ctx,struct audit_chunk * chunk)366 static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
367 {
368 	struct audit_tree_refs *p = ctx->trees;
369 	int left = ctx->tree_count;
370 	if (likely(left)) {
371 		p->c[--left] = chunk;
372 		ctx->tree_count = left;
373 		return 1;
374 	}
375 	if (!p)
376 		return 0;
377 	p = p->next;
378 	if (p) {
379 		p->c[30] = chunk;
380 		ctx->trees = p;
381 		ctx->tree_count = 30;
382 		return 1;
383 	}
384 	return 0;
385 }
386 
grow_tree_refs(struct audit_context * ctx)387 static int grow_tree_refs(struct audit_context *ctx)
388 {
389 	struct audit_tree_refs *p = ctx->trees;
390 	ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
391 	if (!ctx->trees) {
392 		ctx->trees = p;
393 		return 0;
394 	}
395 	if (p)
396 		p->next = ctx->trees;
397 	else
398 		ctx->first_trees = ctx->trees;
399 	ctx->tree_count = 31;
400 	return 1;
401 }
402 #endif
403 
unroll_tree_refs(struct audit_context * ctx,struct audit_tree_refs * p,int count)404 static void unroll_tree_refs(struct audit_context *ctx,
405 		      struct audit_tree_refs *p, int count)
406 {
407 #ifdef CONFIG_AUDIT_TREE
408 	struct audit_tree_refs *q;
409 	int n;
410 	if (!p) {
411 		/* we started with empty chain */
412 		p = ctx->first_trees;
413 		count = 31;
414 		/* if the very first allocation has failed, nothing to do */
415 		if (!p)
416 			return;
417 	}
418 	n = count;
419 	for (q = p; q != ctx->trees; q = q->next, n = 31) {
420 		while (n--) {
421 			audit_put_chunk(q->c[n]);
422 			q->c[n] = NULL;
423 		}
424 	}
425 	while (n-- > ctx->tree_count) {
426 		audit_put_chunk(q->c[n]);
427 		q->c[n] = NULL;
428 	}
429 	ctx->trees = p;
430 	ctx->tree_count = count;
431 #endif
432 }
433 
free_tree_refs(struct audit_context * ctx)434 static void free_tree_refs(struct audit_context *ctx)
435 {
436 	struct audit_tree_refs *p, *q;
437 	for (p = ctx->first_trees; p; p = q) {
438 		q = p->next;
439 		kfree(p);
440 	}
441 }
442 
match_tree_refs(struct audit_context * ctx,struct audit_tree * tree)443 static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
444 {
445 #ifdef CONFIG_AUDIT_TREE
446 	struct audit_tree_refs *p;
447 	int n;
448 	if (!tree)
449 		return 0;
450 	/* full ones */
451 	for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
452 		for (n = 0; n < 31; n++)
453 			if (audit_tree_match(p->c[n], tree))
454 				return 1;
455 	}
456 	/* partial */
457 	if (p) {
458 		for (n = ctx->tree_count; n < 31; n++)
459 			if (audit_tree_match(p->c[n], tree))
460 				return 1;
461 	}
462 #endif
463 	return 0;
464 }
465 
audit_compare_id(uid_t uid1,struct audit_names * name,unsigned long name_offset,struct audit_field * f,struct audit_context * ctx)466 static int audit_compare_id(uid_t uid1,
467 			    struct audit_names *name,
468 			    unsigned long name_offset,
469 			    struct audit_field *f,
470 			    struct audit_context *ctx)
471 {
472 	struct audit_names *n;
473 	unsigned long addr;
474 	uid_t uid2;
475 	int rc;
476 
477 	BUILD_BUG_ON(sizeof(uid_t) != sizeof(gid_t));
478 
479 	if (name) {
480 		addr = (unsigned long)name;
481 		addr += name_offset;
482 
483 		uid2 = *(uid_t *)addr;
484 		rc = audit_comparator(uid1, f->op, uid2);
485 		if (rc)
486 			return rc;
487 	}
488 
489 	if (ctx) {
490 		list_for_each_entry(n, &ctx->names_list, list) {
491 			addr = (unsigned long)n;
492 			addr += name_offset;
493 
494 			uid2 = *(uid_t *)addr;
495 
496 			rc = audit_comparator(uid1, f->op, uid2);
497 			if (rc)
498 				return rc;
499 		}
500 	}
501 	return 0;
502 }
503 
audit_field_compare(struct task_struct * tsk,const struct cred * cred,struct audit_field * f,struct audit_context * ctx,struct audit_names * name)504 static int audit_field_compare(struct task_struct *tsk,
505 			       const struct cred *cred,
506 			       struct audit_field *f,
507 			       struct audit_context *ctx,
508 			       struct audit_names *name)
509 {
510 	switch (f->val) {
511 	/* process to file object comparisons */
512 	case AUDIT_COMPARE_UID_TO_OBJ_UID:
513 		return audit_compare_id(cred->uid,
514 					name, offsetof(struct audit_names, uid),
515 					f, ctx);
516 	case AUDIT_COMPARE_GID_TO_OBJ_GID:
517 		return audit_compare_id(cred->gid,
518 					name, offsetof(struct audit_names, gid),
519 					f, ctx);
520 	case AUDIT_COMPARE_EUID_TO_OBJ_UID:
521 		return audit_compare_id(cred->euid,
522 					name, offsetof(struct audit_names, uid),
523 					f, ctx);
524 	case AUDIT_COMPARE_EGID_TO_OBJ_GID:
525 		return audit_compare_id(cred->egid,
526 					name, offsetof(struct audit_names, gid),
527 					f, ctx);
528 	case AUDIT_COMPARE_AUID_TO_OBJ_UID:
529 		return audit_compare_id(tsk->loginuid,
530 					name, offsetof(struct audit_names, uid),
531 					f, ctx);
532 	case AUDIT_COMPARE_SUID_TO_OBJ_UID:
533 		return audit_compare_id(cred->suid,
534 					name, offsetof(struct audit_names, uid),
535 					f, ctx);
536 	case AUDIT_COMPARE_SGID_TO_OBJ_GID:
537 		return audit_compare_id(cred->sgid,
538 					name, offsetof(struct audit_names, gid),
539 					f, ctx);
540 	case AUDIT_COMPARE_FSUID_TO_OBJ_UID:
541 		return audit_compare_id(cred->fsuid,
542 					name, offsetof(struct audit_names, uid),
543 					f, ctx);
544 	case AUDIT_COMPARE_FSGID_TO_OBJ_GID:
545 		return audit_compare_id(cred->fsgid,
546 					name, offsetof(struct audit_names, gid),
547 					f, ctx);
548 	/* uid comparisons */
549 	case AUDIT_COMPARE_UID_TO_AUID:
550 		return audit_comparator(cred->uid, f->op, tsk->loginuid);
551 	case AUDIT_COMPARE_UID_TO_EUID:
552 		return audit_comparator(cred->uid, f->op, cred->euid);
553 	case AUDIT_COMPARE_UID_TO_SUID:
554 		return audit_comparator(cred->uid, f->op, cred->suid);
555 	case AUDIT_COMPARE_UID_TO_FSUID:
556 		return audit_comparator(cred->uid, f->op, cred->fsuid);
557 	/* auid comparisons */
558 	case AUDIT_COMPARE_AUID_TO_EUID:
559 		return audit_comparator(tsk->loginuid, f->op, cred->euid);
560 	case AUDIT_COMPARE_AUID_TO_SUID:
561 		return audit_comparator(tsk->loginuid, f->op, cred->suid);
562 	case AUDIT_COMPARE_AUID_TO_FSUID:
563 		return audit_comparator(tsk->loginuid, f->op, cred->fsuid);
564 	/* euid comparisons */
565 	case AUDIT_COMPARE_EUID_TO_SUID:
566 		return audit_comparator(cred->euid, f->op, cred->suid);
567 	case AUDIT_COMPARE_EUID_TO_FSUID:
568 		return audit_comparator(cred->euid, f->op, cred->fsuid);
569 	/* suid comparisons */
570 	case AUDIT_COMPARE_SUID_TO_FSUID:
571 		return audit_comparator(cred->suid, f->op, cred->fsuid);
572 	/* gid comparisons */
573 	case AUDIT_COMPARE_GID_TO_EGID:
574 		return audit_comparator(cred->gid, f->op, cred->egid);
575 	case AUDIT_COMPARE_GID_TO_SGID:
576 		return audit_comparator(cred->gid, f->op, cred->sgid);
577 	case AUDIT_COMPARE_GID_TO_FSGID:
578 		return audit_comparator(cred->gid, f->op, cred->fsgid);
579 	/* egid comparisons */
580 	case AUDIT_COMPARE_EGID_TO_SGID:
581 		return audit_comparator(cred->egid, f->op, cred->sgid);
582 	case AUDIT_COMPARE_EGID_TO_FSGID:
583 		return audit_comparator(cred->egid, f->op, cred->fsgid);
584 	/* sgid comparison */
585 	case AUDIT_COMPARE_SGID_TO_FSGID:
586 		return audit_comparator(cred->sgid, f->op, cred->fsgid);
587 	default:
588 		WARN(1, "Missing AUDIT_COMPARE define.  Report as a bug\n");
589 		return 0;
590 	}
591 	return 0;
592 }
593 
594 /* Determine if any context name data matches a rule's watch data */
595 /* Compare a task_struct with an audit_rule.  Return 1 on match, 0
596  * otherwise.
597  *
598  * If task_creation is true, this is an explicit indication that we are
599  * filtering a task rule at task creation time.  This and tsk == current are
600  * the only situations where tsk->cred may be accessed without an rcu read lock.
601  */
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)602 static int audit_filter_rules(struct task_struct *tsk,
603 			      struct audit_krule *rule,
604 			      struct audit_context *ctx,
605 			      struct audit_names *name,
606 			      enum audit_state *state,
607 			      bool task_creation)
608 {
609 	const struct cred *cred;
610 	int i, need_sid = 1;
611 	u32 sid;
612 
613 	cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);
614 
615 	for (i = 0; i < rule->field_count; i++) {
616 		struct audit_field *f = &rule->fields[i];
617 		struct audit_names *n;
618 		int result = 0;
619 
620 		switch (f->type) {
621 		case AUDIT_PID:
622 			result = audit_comparator(tsk->pid, f->op, f->val);
623 			break;
624 		case AUDIT_PPID:
625 			if (ctx) {
626 				if (!ctx->ppid)
627 					ctx->ppid = sys_getppid();
628 				result = audit_comparator(ctx->ppid, f->op, f->val);
629 			}
630 			break;
631 		case AUDIT_UID:
632 			result = audit_comparator(cred->uid, f->op, f->val);
633 			break;
634 		case AUDIT_EUID:
635 			result = audit_comparator(cred->euid, f->op, f->val);
636 			break;
637 		case AUDIT_SUID:
638 			result = audit_comparator(cred->suid, f->op, f->val);
639 			break;
640 		case AUDIT_FSUID:
641 			result = audit_comparator(cred->fsuid, f->op, f->val);
642 			break;
643 		case AUDIT_GID:
644 			result = audit_comparator(cred->gid, f->op, f->val);
645 			break;
646 		case AUDIT_EGID:
647 			result = audit_comparator(cred->egid, f->op, f->val);
648 			break;
649 		case AUDIT_SGID:
650 			result = audit_comparator(cred->sgid, f->op, f->val);
651 			break;
652 		case AUDIT_FSGID:
653 			result = audit_comparator(cred->fsgid, f->op, f->val);
654 			break;
655 		case AUDIT_PERS:
656 			result = audit_comparator(tsk->personality, f->op, f->val);
657 			break;
658 		case AUDIT_ARCH:
659 			if (ctx)
660 				result = audit_comparator(ctx->arch, f->op, f->val);
661 			break;
662 
663 		case AUDIT_EXIT:
664 			if (ctx && ctx->return_valid)
665 				result = audit_comparator(ctx->return_code, f->op, f->val);
666 			break;
667 		case AUDIT_SUCCESS:
668 			if (ctx && ctx->return_valid) {
669 				if (f->val)
670 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
671 				else
672 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE);
673 			}
674 			break;
675 		case AUDIT_DEVMAJOR:
676 			if (name) {
677 				if (audit_comparator(MAJOR(name->dev), f->op, f->val) ||
678 				    audit_comparator(MAJOR(name->rdev), f->op, f->val))
679 					++result;
680 			} else if (ctx) {
681 				list_for_each_entry(n, &ctx->names_list, list) {
682 					if (audit_comparator(MAJOR(n->dev), f->op, f->val) ||
683 					    audit_comparator(MAJOR(n->rdev), f->op, f->val)) {
684 						++result;
685 						break;
686 					}
687 				}
688 			}
689 			break;
690 		case AUDIT_DEVMINOR:
691 			if (name) {
692 				if (audit_comparator(MINOR(name->dev), f->op, f->val) ||
693 				    audit_comparator(MINOR(name->rdev), f->op, f->val))
694 					++result;
695 			} else if (ctx) {
696 				list_for_each_entry(n, &ctx->names_list, list) {
697 					if (audit_comparator(MINOR(n->dev), f->op, f->val) ||
698 					    audit_comparator(MINOR(n->rdev), f->op, f->val)) {
699 						++result;
700 						break;
701 					}
702 				}
703 			}
704 			break;
705 		case AUDIT_INODE:
706 			if (name)
707 				result = (name->ino == f->val);
708 			else if (ctx) {
709 				list_for_each_entry(n, &ctx->names_list, list) {
710 					if (audit_comparator(n->ino, f->op, f->val)) {
711 						++result;
712 						break;
713 					}
714 				}
715 			}
716 			break;
717 		case AUDIT_OBJ_UID:
718 			if (name) {
719 				result = audit_comparator(name->uid, f->op, f->val);
720 			} else if (ctx) {
721 				list_for_each_entry(n, &ctx->names_list, list) {
722 					if (audit_comparator(n->uid, f->op, f->val)) {
723 						++result;
724 						break;
725 					}
726 				}
727 			}
728 			break;
729 		case AUDIT_OBJ_GID:
730 			if (name) {
731 				result = audit_comparator(name->gid, f->op, f->val);
732 			} else if (ctx) {
733 				list_for_each_entry(n, &ctx->names_list, list) {
734 					if (audit_comparator(n->gid, f->op, f->val)) {
735 						++result;
736 						break;
737 					}
738 				}
739 			}
740 			break;
741 		case AUDIT_WATCH:
742 			if (name)
743 				result = audit_watch_compare(rule->watch, name->ino, name->dev);
744 			break;
745 		case AUDIT_DIR:
746 			if (ctx)
747 				result = match_tree_refs(ctx, rule->tree);
748 			break;
749 		case AUDIT_LOGINUID:
750 			result = 0;
751 			if (ctx)
752 				result = audit_comparator(tsk->loginuid, f->op, f->val);
753 			break;
754 		case AUDIT_SUBJ_USER:
755 		case AUDIT_SUBJ_ROLE:
756 		case AUDIT_SUBJ_TYPE:
757 		case AUDIT_SUBJ_SEN:
758 		case AUDIT_SUBJ_CLR:
759 			/* NOTE: this may return negative values indicating
760 			   a temporary error.  We simply treat this as a
761 			   match for now to avoid losing information that
762 			   may be wanted.   An error message will also be
763 			   logged upon error */
764 			if (f->lsm_rule) {
765 				if (need_sid) {
766 					security_task_getsecid(tsk, &sid);
767 					need_sid = 0;
768 				}
769 				result = security_audit_rule_match(sid, f->type,
770 				                                  f->op,
771 				                                  f->lsm_rule,
772 				                                  ctx);
773 			}
774 			break;
775 		case AUDIT_OBJ_USER:
776 		case AUDIT_OBJ_ROLE:
777 		case AUDIT_OBJ_TYPE:
778 		case AUDIT_OBJ_LEV_LOW:
779 		case AUDIT_OBJ_LEV_HIGH:
780 			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
781 			   also applies here */
782 			if (f->lsm_rule) {
783 				/* Find files that match */
784 				if (name) {
785 					result = security_audit_rule_match(
786 					           name->osid, f->type, f->op,
787 					           f->lsm_rule, ctx);
788 				} else if (ctx) {
789 					list_for_each_entry(n, &ctx->names_list, list) {
790 						if (security_audit_rule_match(n->osid, f->type,
791 									      f->op, f->lsm_rule,
792 									      ctx)) {
793 							++result;
794 							break;
795 						}
796 					}
797 				}
798 				/* Find ipc objects that match */
799 				if (!ctx || ctx->type != AUDIT_IPC)
800 					break;
801 				if (security_audit_rule_match(ctx->ipc.osid,
802 							      f->type, f->op,
803 							      f->lsm_rule, ctx))
804 					++result;
805 			}
806 			break;
807 		case AUDIT_ARG0:
808 		case AUDIT_ARG1:
809 		case AUDIT_ARG2:
810 		case AUDIT_ARG3:
811 			if (ctx)
812 				result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val);
813 			break;
814 		case AUDIT_FILTERKEY:
815 			/* ignore this field for filtering */
816 			result = 1;
817 			break;
818 		case AUDIT_PERM:
819 			result = audit_match_perm(ctx, f->val);
820 			break;
821 		case AUDIT_FILETYPE:
822 			result = audit_match_filetype(ctx, f->val);
823 			break;
824 		case AUDIT_FIELD_COMPARE:
825 			result = audit_field_compare(tsk, cred, f, ctx, name);
826 			break;
827 		}
828 		if (!result)
829 			return 0;
830 	}
831 
832 	if (ctx) {
833 		if (rule->prio <= ctx->prio)
834 			return 0;
835 		if (rule->filterkey) {
836 			kfree(ctx->filterkey);
837 			ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
838 		}
839 		ctx->prio = rule->prio;
840 	}
841 	switch (rule->action) {
842 	case AUDIT_NEVER:    *state = AUDIT_DISABLED;	    break;
843 	case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
844 	}
845 	return 1;
846 }
847 
848 /* At process creation time, we can determine if system-call auditing is
849  * completely disabled for this task.  Since we only have the task
850  * structure at this point, we can only check uid and gid.
851  */
audit_filter_task(struct task_struct * tsk,char ** key)852 static enum audit_state audit_filter_task(struct task_struct *tsk, char **key)
853 {
854 	struct audit_entry *e;
855 	enum audit_state   state;
856 
857 	rcu_read_lock();
858 	list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
859 		if (audit_filter_rules(tsk, &e->rule, NULL, NULL,
860 				       &state, true)) {
861 			if (state == AUDIT_RECORD_CONTEXT)
862 				*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);
863 			rcu_read_unlock();
864 			return state;
865 		}
866 	}
867 	rcu_read_unlock();
868 	return AUDIT_BUILD_CONTEXT;
869 }
870 
audit_in_mask(const struct audit_krule * rule,unsigned long val)871 static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
872 {
873 	int word, bit;
874 
875 	if (val > 0xffffffff)
876 		return false;
877 
878 	word = AUDIT_WORD(val);
879 	if (word >= AUDIT_BITMASK_SIZE)
880 		return false;
881 
882 	bit = AUDIT_BIT(val);
883 
884 	return rule->mask[word] & bit;
885 }
886 
887 /* At syscall entry and exit time, this filter is called if the
888  * audit_state is not low enough that auditing cannot take place, but is
889  * also not high enough that we already know we have to write an audit
890  * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
891  */
audit_filter_syscall(struct task_struct * tsk,struct audit_context * ctx,struct list_head * list)892 static enum audit_state audit_filter_syscall(struct task_struct *tsk,
893 					     struct audit_context *ctx,
894 					     struct list_head *list)
895 {
896 	struct audit_entry *e;
897 	enum audit_state state;
898 
899 	if (audit_pid && tsk->tgid == audit_pid)
900 		return AUDIT_DISABLED;
901 
902 	rcu_read_lock();
903 	if (!list_empty(list)) {
904 		list_for_each_entry_rcu(e, list, list) {
905 			if (audit_in_mask(&e->rule, ctx->major) &&
906 			    audit_filter_rules(tsk, &e->rule, ctx, NULL,
907 					       &state, false)) {
908 				rcu_read_unlock();
909 				ctx->current_state = state;
910 				return state;
911 			}
912 		}
913 	}
914 	rcu_read_unlock();
915 	return AUDIT_BUILD_CONTEXT;
916 }
917 
918 /*
919  * Given an audit_name check the inode hash table to see if they match.
920  * Called holding the rcu read lock to protect the use of audit_inode_hash
921  */
audit_filter_inode_name(struct task_struct * tsk,struct audit_names * n,struct audit_context * ctx)922 static int audit_filter_inode_name(struct task_struct *tsk,
923 				   struct audit_names *n,
924 				   struct audit_context *ctx) {
925 	int h = audit_hash_ino((u32)n->ino);
926 	struct list_head *list = &audit_inode_hash[h];
927 	struct audit_entry *e;
928 	enum audit_state state;
929 
930 	if (list_empty(list))
931 		return 0;
932 
933 	list_for_each_entry_rcu(e, list, list) {
934 		if (audit_in_mask(&e->rule, ctx->major) &&
935 		    audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {
936 			ctx->current_state = state;
937 			return 1;
938 		}
939 	}
940 
941 	return 0;
942 }
943 
944 /* At syscall exit time, this filter is called if any audit_names have been
945  * collected during syscall processing.  We only check rules in sublists at hash
946  * buckets applicable to the inode numbers in audit_names.
947  * Regarding audit_state, same rules apply as for audit_filter_syscall().
948  */
audit_filter_inodes(struct task_struct * tsk,struct audit_context * ctx)949 void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)
950 {
951 	struct audit_names *n;
952 
953 	if (audit_pid && tsk->tgid == audit_pid)
954 		return;
955 
956 	rcu_read_lock();
957 
958 	list_for_each_entry(n, &ctx->names_list, list) {
959 		if (audit_filter_inode_name(tsk, n, ctx))
960 			break;
961 	}
962 	rcu_read_unlock();
963 }
964 
audit_get_context(struct task_struct * tsk,int return_valid,long return_code)965 static inline struct audit_context *audit_get_context(struct task_struct *tsk,
966 						      int return_valid,
967 						      long return_code)
968 {
969 	struct audit_context *context = tsk->audit_context;
970 
971 	if (!context)
972 		return NULL;
973 	context->return_valid = return_valid;
974 
975 	/*
976 	 * we need to fix up the return code in the audit logs if the actual
977 	 * return codes are later going to be fixed up by the arch specific
978 	 * signal handlers
979 	 *
980 	 * This is actually a test for:
981 	 * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) ||
982 	 * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK)
983 	 *
984 	 * but is faster than a bunch of ||
985 	 */
986 	if (unlikely(return_code <= -ERESTARTSYS) &&
987 	    (return_code >= -ERESTART_RESTARTBLOCK) &&
988 	    (return_code != -ENOIOCTLCMD))
989 		context->return_code = -EINTR;
990 	else
991 		context->return_code  = return_code;
992 
993 	if (context->in_syscall && !context->dummy) {
994 		audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
995 		audit_filter_inodes(tsk, context);
996 	}
997 
998 	tsk->audit_context = NULL;
999 	return context;
1000 }
1001 
audit_free_names(struct audit_context * context)1002 static inline void audit_free_names(struct audit_context *context)
1003 {
1004 	struct audit_names *n, *next;
1005 
1006 #if AUDIT_DEBUG == 2
1007 	if (context->put_count + context->ino_count != context->name_count) {
1008 		printk(KERN_ERR "%s:%d(:%d): major=%d in_syscall=%d"
1009 		       " name_count=%d put_count=%d"
1010 		       " ino_count=%d [NOT freeing]\n",
1011 		       __FILE__, __LINE__,
1012 		       context->serial, context->major, context->in_syscall,
1013 		       context->name_count, context->put_count,
1014 		       context->ino_count);
1015 		list_for_each_entry(n, &context->names_list, list) {
1016 			printk(KERN_ERR "names[%d] = %p = %s\n", i,
1017 			       n->name, n->name ?: "(null)");
1018 		}
1019 		dump_stack();
1020 		return;
1021 	}
1022 #endif
1023 #if AUDIT_DEBUG
1024 	context->put_count  = 0;
1025 	context->ino_count  = 0;
1026 #endif
1027 
1028 	list_for_each_entry_safe(n, next, &context->names_list, list) {
1029 		list_del(&n->list);
1030 		if (n->name && n->name_put)
1031 			__putname(n->name);
1032 		if (n->should_free)
1033 			kfree(n);
1034 	}
1035 	context->name_count = 0;
1036 	path_put(&context->pwd);
1037 	context->pwd.dentry = NULL;
1038 	context->pwd.mnt = NULL;
1039 }
1040 
audit_free_aux(struct audit_context * context)1041 static inline void audit_free_aux(struct audit_context *context)
1042 {
1043 	struct audit_aux_data *aux;
1044 
1045 	while ((aux = context->aux)) {
1046 		context->aux = aux->next;
1047 		kfree(aux);
1048 	}
1049 	while ((aux = context->aux_pids)) {
1050 		context->aux_pids = aux->next;
1051 		kfree(aux);
1052 	}
1053 }
1054 
audit_zero_context(struct audit_context * context,enum audit_state state)1055 static inline void audit_zero_context(struct audit_context *context,
1056 				      enum audit_state state)
1057 {
1058 	memset(context, 0, sizeof(*context));
1059 	context->state      = state;
1060 	context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
1061 }
1062 
audit_alloc_context(enum audit_state state)1063 static inline struct audit_context *audit_alloc_context(enum audit_state state)
1064 {
1065 	struct audit_context *context;
1066 
1067 	if (!(context = kmalloc(sizeof(*context), GFP_KERNEL)))
1068 		return NULL;
1069 	audit_zero_context(context, state);
1070 	INIT_LIST_HEAD(&context->killed_trees);
1071 	INIT_LIST_HEAD(&context->names_list);
1072 	return context;
1073 }
1074 
1075 /**
1076  * audit_alloc - allocate an audit context block for a task
1077  * @tsk: task
1078  *
1079  * Filter on the task information and allocate a per-task audit context
1080  * if necessary.  Doing so turns on system call auditing for the
1081  * specified task.  This is called from copy_process, so no lock is
1082  * needed.
1083  */
audit_alloc(struct task_struct * tsk)1084 int audit_alloc(struct task_struct *tsk)
1085 {
1086 	struct audit_context *context;
1087 	enum audit_state     state;
1088 	char *key = NULL;
1089 
1090 	if (likely(!audit_ever_enabled))
1091 		return 0; /* Return if not auditing. */
1092 
1093 	state = audit_filter_task(tsk, &key);
1094 	if (state == AUDIT_DISABLED)
1095 		return 0;
1096 
1097 	if (!(context = audit_alloc_context(state))) {
1098 		kfree(key);
1099 		audit_log_lost("out of memory in audit_alloc");
1100 		return -ENOMEM;
1101 	}
1102 	context->filterkey = key;
1103 
1104 	tsk->audit_context  = context;
1105 	set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);
1106 	return 0;
1107 }
1108 
audit_free_context(struct audit_context * context)1109 static inline void audit_free_context(struct audit_context *context)
1110 {
1111 	struct audit_context *previous;
1112 	int		     count = 0;
1113 
1114 	do {
1115 		previous = context->previous;
1116 		if (previous || (count &&  count < 10)) {
1117 			++count;
1118 			printk(KERN_ERR "audit(:%d): major=%d name_count=%d:"
1119 			       " freeing multiple contexts (%d)\n",
1120 			       context->serial, context->major,
1121 			       context->name_count, count);
1122 		}
1123 		audit_free_names(context);
1124 		unroll_tree_refs(context, NULL, 0);
1125 		free_tree_refs(context);
1126 		audit_free_aux(context);
1127 		kfree(context->filterkey);
1128 		kfree(context->sockaddr);
1129 		kfree(context);
1130 		context  = previous;
1131 	} while (context);
1132 	if (count >= 10)
1133 		printk(KERN_ERR "audit: freed %d contexts\n", count);
1134 }
1135 
audit_log_task_context(struct audit_buffer * ab)1136 void audit_log_task_context(struct audit_buffer *ab)
1137 {
1138 	char *ctx = NULL;
1139 	unsigned len;
1140 	int error;
1141 	u32 sid;
1142 
1143 	security_task_getsecid(current, &sid);
1144 	if (!sid)
1145 		return;
1146 
1147 	error = security_secid_to_secctx(sid, &ctx, &len);
1148 	if (error) {
1149 		if (error != -EINVAL)
1150 			goto error_path;
1151 		return;
1152 	}
1153 
1154 	audit_log_format(ab, " subj=%s", ctx);
1155 	security_release_secctx(ctx, len);
1156 	return;
1157 
1158 error_path:
1159 	audit_panic("error in audit_log_task_context");
1160 	return;
1161 }
1162 
1163 EXPORT_SYMBOL(audit_log_task_context);
1164 
audit_log_task_info(struct audit_buffer * ab,struct task_struct * tsk)1165 static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
1166 {
1167 	char name[sizeof(tsk->comm)];
1168 	struct mm_struct *mm = tsk->mm;
1169 	struct vm_area_struct *vma;
1170 
1171 	/* tsk == current */
1172 
1173 	get_task_comm(name, tsk);
1174 	audit_log_format(ab, " comm=");
1175 	audit_log_untrustedstring(ab, name);
1176 
1177 	if (mm) {
1178 		down_read(&mm->mmap_sem);
1179 		vma = mm->mmap;
1180 		while (vma) {
1181 			if ((vma->vm_flags & VM_EXECUTABLE) &&
1182 			    vma->vm_file) {
1183 				audit_log_d_path(ab, " exe=",
1184 						 &vma->vm_file->f_path);
1185 				break;
1186 			}
1187 			vma = vma->vm_next;
1188 		}
1189 		up_read(&mm->mmap_sem);
1190 	}
1191 	audit_log_task_context(ab);
1192 }
1193 
audit_log_pid_context(struct audit_context * context,pid_t pid,uid_t auid,uid_t uid,unsigned int sessionid,u32 sid,char * comm)1194 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
1195 				 uid_t auid, uid_t uid, unsigned int sessionid,
1196 				 u32 sid, char *comm)
1197 {
1198 	struct audit_buffer *ab;
1199 	char *ctx = NULL;
1200 	u32 len;
1201 	int rc = 0;
1202 
1203 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
1204 	if (!ab)
1205 		return rc;
1206 
1207 	audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid, auid,
1208 			 uid, sessionid);
1209 	if (security_secid_to_secctx(sid, &ctx, &len)) {
1210 		audit_log_format(ab, " obj=(none)");
1211 		rc = 1;
1212 	} else {
1213 		audit_log_format(ab, " obj=%s", ctx);
1214 		security_release_secctx(ctx, len);
1215 	}
1216 	audit_log_format(ab, " ocomm=");
1217 	audit_log_untrustedstring(ab, comm);
1218 	audit_log_end(ab);
1219 
1220 	return rc;
1221 }
1222 
1223 /*
1224  * to_send and len_sent accounting are very loose estimates.  We aren't
1225  * really worried about a hard cap to MAX_EXECVE_AUDIT_LEN so much as being
1226  * within about 500 bytes (next page boundary)
1227  *
1228  * why snprintf?  an int is up to 12 digits long.  if we just assumed when
1229  * logging that a[%d]= was going to be 16 characters long we would be wasting
1230  * space in every audit message.  In one 7500 byte message we can log up to
1231  * about 1000 min size arguments.  That comes down to about 50% waste of space
1232  * if we didn't do the snprintf to find out how long arg_num_len was.
1233  */
audit_log_single_execve_arg(struct audit_context * context,struct audit_buffer ** ab,int arg_num,size_t * len_sent,const char __user * p,char * buf)1234 static int audit_log_single_execve_arg(struct audit_context *context,
1235 					struct audit_buffer **ab,
1236 					int arg_num,
1237 					size_t *len_sent,
1238 					const char __user *p,
1239 					char *buf)
1240 {
1241 	char arg_num_len_buf[12];
1242 	const char __user *tmp_p = p;
1243 	/* how many digits are in arg_num? 5 is the length of ' a=""' */
1244 	size_t arg_num_len = snprintf(arg_num_len_buf, 12, "%d", arg_num) + 5;
1245 	size_t len, len_left, to_send;
1246 	size_t max_execve_audit_len = MAX_EXECVE_AUDIT_LEN;
1247 	unsigned int i, has_cntl = 0, too_long = 0;
1248 	int ret;
1249 
1250 	/* strnlen_user includes the null we don't want to send */
1251 	len_left = len = strnlen_user(p, MAX_ARG_STRLEN) - 1;
1252 
1253 	/*
1254 	 * We just created this mm, if we can't find the strings
1255 	 * we just copied into it something is _very_ wrong. Similar
1256 	 * for strings that are too long, we should not have created
1257 	 * any.
1258 	 */
1259 	if (unlikely((len == -1) || len > MAX_ARG_STRLEN - 1)) {
1260 		WARN_ON(1);
1261 		send_sig(SIGKILL, current, 0);
1262 		return -1;
1263 	}
1264 
1265 	/* walk the whole argument looking for non-ascii chars */
1266 	do {
1267 		if (len_left > MAX_EXECVE_AUDIT_LEN)
1268 			to_send = MAX_EXECVE_AUDIT_LEN;
1269 		else
1270 			to_send = len_left;
1271 		ret = copy_from_user(buf, tmp_p, to_send);
1272 		/*
1273 		 * There is no reason for this copy to be short. We just
1274 		 * copied them here, and the mm hasn't been exposed to user-
1275 		 * space yet.
1276 		 */
1277 		if (ret) {
1278 			WARN_ON(1);
1279 			send_sig(SIGKILL, current, 0);
1280 			return -1;
1281 		}
1282 		buf[to_send] = '\0';
1283 		has_cntl = audit_string_contains_control(buf, to_send);
1284 		if (has_cntl) {
1285 			/*
1286 			 * hex messages get logged as 2 bytes, so we can only
1287 			 * send half as much in each message
1288 			 */
1289 			max_execve_audit_len = MAX_EXECVE_AUDIT_LEN / 2;
1290 			break;
1291 		}
1292 		len_left -= to_send;
1293 		tmp_p += to_send;
1294 	} while (len_left > 0);
1295 
1296 	len_left = len;
1297 
1298 	if (len > max_execve_audit_len)
1299 		too_long = 1;
1300 
1301 	/* rewalk the argument actually logging the message */
1302 	for (i = 0; len_left > 0; i++) {
1303 		int room_left;
1304 
1305 		if (len_left > max_execve_audit_len)
1306 			to_send = max_execve_audit_len;
1307 		else
1308 			to_send = len_left;
1309 
1310 		/* do we have space left to send this argument in this ab? */
1311 		room_left = MAX_EXECVE_AUDIT_LEN - arg_num_len - *len_sent;
1312 		if (has_cntl)
1313 			room_left -= (to_send * 2);
1314 		else
1315 			room_left -= to_send;
1316 		if (room_left < 0) {
1317 			*len_sent = 0;
1318 			audit_log_end(*ab);
1319 			*ab = audit_log_start(context, GFP_KERNEL, AUDIT_EXECVE);
1320 			if (!*ab)
1321 				return 0;
1322 		}
1323 
1324 		/*
1325 		 * first record needs to say how long the original string was
1326 		 * so we can be sure nothing was lost.
1327 		 */
1328 		if ((i == 0) && (too_long))
1329 			audit_log_format(*ab, " a%d_len=%zu", arg_num,
1330 					 has_cntl ? 2*len : len);
1331 
1332 		/*
1333 		 * normally arguments are small enough to fit and we already
1334 		 * filled buf above when we checked for control characters
1335 		 * so don't bother with another copy_from_user
1336 		 */
1337 		if (len >= max_execve_audit_len)
1338 			ret = copy_from_user(buf, p, to_send);
1339 		else
1340 			ret = 0;
1341 		if (ret) {
1342 			WARN_ON(1);
1343 			send_sig(SIGKILL, current, 0);
1344 			return -1;
1345 		}
1346 		buf[to_send] = '\0';
1347 
1348 		/* actually log it */
1349 		audit_log_format(*ab, " a%d", arg_num);
1350 		if (too_long)
1351 			audit_log_format(*ab, "[%d]", i);
1352 		audit_log_format(*ab, "=");
1353 		if (has_cntl)
1354 			audit_log_n_hex(*ab, buf, to_send);
1355 		else
1356 			audit_log_string(*ab, buf);
1357 
1358 		p += to_send;
1359 		len_left -= to_send;
1360 		*len_sent += arg_num_len;
1361 		if (has_cntl)
1362 			*len_sent += to_send * 2;
1363 		else
1364 			*len_sent += to_send;
1365 	}
1366 	/* include the null we didn't log */
1367 	return len + 1;
1368 }
1369 
audit_log_execve_info(struct audit_context * context,struct audit_buffer ** ab,struct audit_aux_data_execve * axi)1370 static void audit_log_execve_info(struct audit_context *context,
1371 				  struct audit_buffer **ab,
1372 				  struct audit_aux_data_execve *axi)
1373 {
1374 	int i, len;
1375 	size_t len_sent = 0;
1376 	const char __user *p;
1377 	char *buf;
1378 
1379 	if (axi->mm != current->mm)
1380 		return; /* execve failed, no additional info */
1381 
1382 	p = (const char __user *)axi->mm->arg_start;
1383 
1384 	audit_log_format(*ab, "argc=%d", axi->argc);
1385 
1386 	/*
1387 	 * we need some kernel buffer to hold the userspace args.  Just
1388 	 * allocate one big one rather than allocating one of the right size
1389 	 * for every single argument inside audit_log_single_execve_arg()
1390 	 * should be <8k allocation so should be pretty safe.
1391 	 */
1392 	buf = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL);
1393 	if (!buf) {
1394 		audit_panic("out of memory for argv string\n");
1395 		return;
1396 	}
1397 
1398 	for (i = 0; i < axi->argc; i++) {
1399 		len = audit_log_single_execve_arg(context, ab, i,
1400 						  &len_sent, p, buf);
1401 		if (len <= 0)
1402 			break;
1403 		p += len;
1404 	}
1405 	kfree(buf);
1406 }
1407 
audit_log_cap(struct audit_buffer * ab,char * prefix,kernel_cap_t * cap)1408 static void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
1409 {
1410 	int i;
1411 
1412 	audit_log_format(ab, " %s=", prefix);
1413 	CAP_FOR_EACH_U32(i) {
1414 		audit_log_format(ab, "%08x", cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]);
1415 	}
1416 }
1417 
audit_log_fcaps(struct audit_buffer * ab,struct audit_names * name)1418 static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
1419 {
1420 	kernel_cap_t *perm = &name->fcap.permitted;
1421 	kernel_cap_t *inh = &name->fcap.inheritable;
1422 	int log = 0;
1423 
1424 	if (!cap_isclear(*perm)) {
1425 		audit_log_cap(ab, "cap_fp", perm);
1426 		log = 1;
1427 	}
1428 	if (!cap_isclear(*inh)) {
1429 		audit_log_cap(ab, "cap_fi", inh);
1430 		log = 1;
1431 	}
1432 
1433 	if (log)
1434 		audit_log_format(ab, " cap_fe=%d cap_fver=%x", name->fcap.fE, name->fcap_ver);
1435 }
1436 
show_special(struct audit_context * context,int * call_panic)1437 static void show_special(struct audit_context *context, int *call_panic)
1438 {
1439 	struct audit_buffer *ab;
1440 	int i;
1441 
1442 	ab = audit_log_start(context, GFP_KERNEL, context->type);
1443 	if (!ab)
1444 		return;
1445 
1446 	switch (context->type) {
1447 	case AUDIT_SOCKETCALL: {
1448 		int nargs = context->socketcall.nargs;
1449 		audit_log_format(ab, "nargs=%d", nargs);
1450 		for (i = 0; i < nargs; i++)
1451 			audit_log_format(ab, " a%d=%lx", i,
1452 				context->socketcall.args[i]);
1453 		break; }
1454 	case AUDIT_IPC: {
1455 		u32 osid = context->ipc.osid;
1456 
1457 		audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
1458 			 context->ipc.uid, context->ipc.gid, context->ipc.mode);
1459 		if (osid) {
1460 			char *ctx = NULL;
1461 			u32 len;
1462 			if (security_secid_to_secctx(osid, &ctx, &len)) {
1463 				audit_log_format(ab, " osid=%u", osid);
1464 				*call_panic = 1;
1465 			} else {
1466 				audit_log_format(ab, " obj=%s", ctx);
1467 				security_release_secctx(ctx, len);
1468 			}
1469 		}
1470 		if (context->ipc.has_perm) {
1471 			audit_log_end(ab);
1472 			ab = audit_log_start(context, GFP_KERNEL,
1473 					     AUDIT_IPC_SET_PERM);
1474 			audit_log_format(ab,
1475 				"qbytes=%lx ouid=%u ogid=%u mode=%#ho",
1476 				context->ipc.qbytes,
1477 				context->ipc.perm_uid,
1478 				context->ipc.perm_gid,
1479 				context->ipc.perm_mode);
1480 			if (!ab)
1481 				return;
1482 		}
1483 		break; }
1484 	case AUDIT_MQ_OPEN: {
1485 		audit_log_format(ab,
1486 			"oflag=0x%x mode=%#ho mq_flags=0x%lx mq_maxmsg=%ld "
1487 			"mq_msgsize=%ld mq_curmsgs=%ld",
1488 			context->mq_open.oflag, context->mq_open.mode,
1489 			context->mq_open.attr.mq_flags,
1490 			context->mq_open.attr.mq_maxmsg,
1491 			context->mq_open.attr.mq_msgsize,
1492 			context->mq_open.attr.mq_curmsgs);
1493 		break; }
1494 	case AUDIT_MQ_SENDRECV: {
1495 		audit_log_format(ab,
1496 			"mqdes=%d msg_len=%zd msg_prio=%u "
1497 			"abs_timeout_sec=%ld abs_timeout_nsec=%ld",
1498 			context->mq_sendrecv.mqdes,
1499 			context->mq_sendrecv.msg_len,
1500 			context->mq_sendrecv.msg_prio,
1501 			context->mq_sendrecv.abs_timeout.tv_sec,
1502 			context->mq_sendrecv.abs_timeout.tv_nsec);
1503 		break; }
1504 	case AUDIT_MQ_NOTIFY: {
1505 		audit_log_format(ab, "mqdes=%d sigev_signo=%d",
1506 				context->mq_notify.mqdes,
1507 				context->mq_notify.sigev_signo);
1508 		break; }
1509 	case AUDIT_MQ_GETSETATTR: {
1510 		struct mq_attr *attr = &context->mq_getsetattr.mqstat;
1511 		audit_log_format(ab,
1512 			"mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld "
1513 			"mq_curmsgs=%ld ",
1514 			context->mq_getsetattr.mqdes,
1515 			attr->mq_flags, attr->mq_maxmsg,
1516 			attr->mq_msgsize, attr->mq_curmsgs);
1517 		break; }
1518 	case AUDIT_CAPSET: {
1519 		audit_log_format(ab, "pid=%d", context->capset.pid);
1520 		audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable);
1521 		audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted);
1522 		audit_log_cap(ab, "cap_pe", &context->capset.cap.effective);
1523 		break; }
1524 	case AUDIT_MMAP: {
1525 		audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd,
1526 				 context->mmap.flags);
1527 		break; }
1528 	}
1529 	audit_log_end(ab);
1530 }
1531 
audit_log_name(struct audit_context * context,struct audit_names * n,int record_num,int * call_panic)1532 static void audit_log_name(struct audit_context *context, struct audit_names *n,
1533 			   int record_num, int *call_panic)
1534 {
1535 	struct audit_buffer *ab;
1536 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
1537 	if (!ab)
1538 		return; /* audit_panic has been called */
1539 
1540 	audit_log_format(ab, "item=%d", record_num);
1541 
1542 	if (n->name) {
1543 		switch (n->name_len) {
1544 		case AUDIT_NAME_FULL:
1545 			/* log the full path */
1546 			audit_log_format(ab, " name=");
1547 			audit_log_untrustedstring(ab, n->name);
1548 			break;
1549 		case 0:
1550 			/* name was specified as a relative path and the
1551 			 * directory component is the cwd */
1552 			audit_log_d_path(ab, " name=", &context->pwd);
1553 			break;
1554 		default:
1555 			/* log the name's directory component */
1556 			audit_log_format(ab, " name=");
1557 			audit_log_n_untrustedstring(ab, n->name,
1558 						    n->name_len);
1559 		}
1560 	} else
1561 		audit_log_format(ab, " name=(null)");
1562 
1563 	if (n->ino != (unsigned long)-1) {
1564 		audit_log_format(ab, " inode=%lu"
1565 				 " dev=%02x:%02x mode=%#ho"
1566 				 " ouid=%u ogid=%u rdev=%02x:%02x",
1567 				 n->ino,
1568 				 MAJOR(n->dev),
1569 				 MINOR(n->dev),
1570 				 n->mode,
1571 				 n->uid,
1572 				 n->gid,
1573 				 MAJOR(n->rdev),
1574 				 MINOR(n->rdev));
1575 	}
1576 	if (n->osid != 0) {
1577 		char *ctx = NULL;
1578 		u32 len;
1579 		if (security_secid_to_secctx(
1580 			n->osid, &ctx, &len)) {
1581 			audit_log_format(ab, " osid=%u", n->osid);
1582 			*call_panic = 2;
1583 		} else {
1584 			audit_log_format(ab, " obj=%s", ctx);
1585 			security_release_secctx(ctx, len);
1586 		}
1587 	}
1588 
1589 	audit_log_fcaps(ab, n);
1590 
1591 	audit_log_end(ab);
1592 }
1593 
audit_log_exit(struct audit_context * context,struct task_struct * tsk)1594 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
1595 {
1596 	const struct cred *cred;
1597 	int i, call_panic = 0;
1598 	struct audit_buffer *ab;
1599 	struct audit_aux_data *aux;
1600 	const char *tty;
1601 	struct audit_names *n;
1602 
1603 	/* tsk == current */
1604 	context->pid = tsk->pid;
1605 	if (!context->ppid)
1606 		context->ppid = sys_getppid();
1607 	cred = current_cred();
1608 	context->uid   = cred->uid;
1609 	context->gid   = cred->gid;
1610 	context->euid  = cred->euid;
1611 	context->suid  = cred->suid;
1612 	context->fsuid = cred->fsuid;
1613 	context->egid  = cred->egid;
1614 	context->sgid  = cred->sgid;
1615 	context->fsgid = cred->fsgid;
1616 	context->personality = tsk->personality;
1617 
1618 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL);
1619 	if (!ab)
1620 		return;		/* audit_panic has been called */
1621 	audit_log_format(ab, "arch=%x syscall=%d",
1622 			 context->arch, context->major);
1623 	if (context->personality != PER_LINUX)
1624 		audit_log_format(ab, " per=%lx", context->personality);
1625 	if (context->return_valid)
1626 		audit_log_format(ab, " success=%s exit=%ld",
1627 				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
1628 				 context->return_code);
1629 
1630 	spin_lock_irq(&tsk->sighand->siglock);
1631 	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
1632 		tty = tsk->signal->tty->name;
1633 	else
1634 		tty = "(none)";
1635 	spin_unlock_irq(&tsk->sighand->siglock);
1636 
1637 	audit_log_format(ab,
1638 		  " a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
1639 		  " ppid=%d pid=%d auid=%u uid=%u gid=%u"
1640 		  " euid=%u suid=%u fsuid=%u"
1641 		  " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
1642 		  context->argv[0],
1643 		  context->argv[1],
1644 		  context->argv[2],
1645 		  context->argv[3],
1646 		  context->name_count,
1647 		  context->ppid,
1648 		  context->pid,
1649 		  tsk->loginuid,
1650 		  context->uid,
1651 		  context->gid,
1652 		  context->euid, context->suid, context->fsuid,
1653 		  context->egid, context->sgid, context->fsgid, tty,
1654 		  tsk->sessionid);
1655 
1656 
1657 	audit_log_task_info(ab, tsk);
1658 	audit_log_key(ab, context->filterkey);
1659 	audit_log_end(ab);
1660 
1661 	for (aux = context->aux; aux; aux = aux->next) {
1662 
1663 		ab = audit_log_start(context, GFP_KERNEL, aux->type);
1664 		if (!ab)
1665 			continue; /* audit_panic has been called */
1666 
1667 		switch (aux->type) {
1668 
1669 		case AUDIT_EXECVE: {
1670 			struct audit_aux_data_execve *axi = (void *)aux;
1671 			audit_log_execve_info(context, &ab, axi);
1672 			break; }
1673 
1674 		case AUDIT_BPRM_FCAPS: {
1675 			struct audit_aux_data_bprm_fcaps *axs = (void *)aux;
1676 			audit_log_format(ab, "fver=%x", axs->fcap_ver);
1677 			audit_log_cap(ab, "fp", &axs->fcap.permitted);
1678 			audit_log_cap(ab, "fi", &axs->fcap.inheritable);
1679 			audit_log_format(ab, " fe=%d", axs->fcap.fE);
1680 			audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted);
1681 			audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable);
1682 			audit_log_cap(ab, "old_pe", &axs->old_pcap.effective);
1683 			audit_log_cap(ab, "new_pp", &axs->new_pcap.permitted);
1684 			audit_log_cap(ab, "new_pi", &axs->new_pcap.inheritable);
1685 			audit_log_cap(ab, "new_pe", &axs->new_pcap.effective);
1686 			break; }
1687 
1688 		}
1689 		audit_log_end(ab);
1690 	}
1691 
1692 	if (context->type)
1693 		show_special(context, &call_panic);
1694 
1695 	if (context->fds[0] >= 0) {
1696 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR);
1697 		if (ab) {
1698 			audit_log_format(ab, "fd0=%d fd1=%d",
1699 					context->fds[0], context->fds[1]);
1700 			audit_log_end(ab);
1701 		}
1702 	}
1703 
1704 	if (context->sockaddr_len) {
1705 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR);
1706 		if (ab) {
1707 			audit_log_format(ab, "saddr=");
1708 			audit_log_n_hex(ab, (void *)context->sockaddr,
1709 					context->sockaddr_len);
1710 			audit_log_end(ab);
1711 		}
1712 	}
1713 
1714 	for (aux = context->aux_pids; aux; aux = aux->next) {
1715 		struct audit_aux_data_pids *axs = (void *)aux;
1716 
1717 		for (i = 0; i < axs->pid_count; i++)
1718 			if (audit_log_pid_context(context, axs->target_pid[i],
1719 						  axs->target_auid[i],
1720 						  axs->target_uid[i],
1721 						  axs->target_sessionid[i],
1722 						  axs->target_sid[i],
1723 						  axs->target_comm[i]))
1724 				call_panic = 1;
1725 	}
1726 
1727 	if (context->target_pid &&
1728 	    audit_log_pid_context(context, context->target_pid,
1729 				  context->target_auid, context->target_uid,
1730 				  context->target_sessionid,
1731 				  context->target_sid, context->target_comm))
1732 			call_panic = 1;
1733 
1734 	if (context->pwd.dentry && context->pwd.mnt) {
1735 		ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
1736 		if (ab) {
1737 			audit_log_d_path(ab, " cwd=", &context->pwd);
1738 			audit_log_end(ab);
1739 		}
1740 	}
1741 
1742 	i = 0;
1743 	list_for_each_entry(n, &context->names_list, list)
1744 		audit_log_name(context, n, i++, &call_panic);
1745 
1746 	/* Send end of event record to help user space know we are finished */
1747 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
1748 	if (ab)
1749 		audit_log_end(ab);
1750 	if (call_panic)
1751 		audit_panic("error converting sid to string");
1752 }
1753 
1754 /**
1755  * audit_free - free a per-task audit context
1756  * @tsk: task whose audit context block to free
1757  *
1758  * Called from copy_process and do_exit
1759  */
__audit_free(struct task_struct * tsk)1760 void __audit_free(struct task_struct *tsk)
1761 {
1762 	struct audit_context *context;
1763 
1764 	context = audit_get_context(tsk, 0, 0);
1765 	if (!context)
1766 		return;
1767 
1768 	/* Check for system calls that do not go through the exit
1769 	 * function (e.g., exit_group), then free context block.
1770 	 * We use GFP_ATOMIC here because we might be doing this
1771 	 * in the context of the idle thread */
1772 	/* that can happen only if we are called from do_exit() */
1773 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1774 		audit_log_exit(context, tsk);
1775 	if (!list_empty(&context->killed_trees))
1776 		audit_kill_trees(&context->killed_trees);
1777 
1778 	audit_free_context(context);
1779 }
1780 
1781 /**
1782  * audit_syscall_entry - fill in an audit record at syscall entry
1783  * @arch: architecture type
1784  * @major: major syscall type (function)
1785  * @a1: additional syscall register 1
1786  * @a2: additional syscall register 2
1787  * @a3: additional syscall register 3
1788  * @a4: additional syscall register 4
1789  *
1790  * Fill in audit context at syscall entry.  This only happens if the
1791  * audit context was created when the task was created and the state or
1792  * filters demand the audit context be built.  If the state from the
1793  * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
1794  * then the record will be written at syscall exit time (otherwise, it
1795  * will only be written if another part of the kernel requests that it
1796  * be written).
1797  */
__audit_syscall_entry(int arch,int major,unsigned long a1,unsigned long a2,unsigned long a3,unsigned long a4)1798 void __audit_syscall_entry(int arch, int major,
1799 			 unsigned long a1, unsigned long a2,
1800 			 unsigned long a3, unsigned long a4)
1801 {
1802 	struct task_struct *tsk = current;
1803 	struct audit_context *context = tsk->audit_context;
1804 	enum audit_state     state;
1805 
1806 	if (!context)
1807 		return;
1808 
1809 	/*
1810 	 * This happens only on certain architectures that make system
1811 	 * calls in kernel_thread via the entry.S interface, instead of
1812 	 * with direct calls.  (If you are porting to a new
1813 	 * architecture, hitting this condition can indicate that you
1814 	 * got the _exit/_leave calls backward in entry.S.)
1815 	 *
1816 	 * i386     no
1817 	 * x86_64   no
1818 	 * ppc64    yes (see arch/powerpc/platforms/iseries/misc.S)
1819 	 *
1820 	 * This also happens with vm86 emulation in a non-nested manner
1821 	 * (entries without exits), so this case must be caught.
1822 	 */
1823 	if (context->in_syscall) {
1824 		struct audit_context *newctx;
1825 
1826 #if AUDIT_DEBUG
1827 		printk(KERN_ERR
1828 		       "audit(:%d) pid=%d in syscall=%d;"
1829 		       " entering syscall=%d\n",
1830 		       context->serial, tsk->pid, context->major, major);
1831 #endif
1832 		newctx = audit_alloc_context(context->state);
1833 		if (newctx) {
1834 			newctx->previous   = context;
1835 			context		   = newctx;
1836 			tsk->audit_context = newctx;
1837 		} else	{
1838 			/* If we can't alloc a new context, the best we
1839 			 * can do is to leak memory (any pending putname
1840 			 * will be lost).  The only other alternative is
1841 			 * to abandon auditing. */
1842 			audit_zero_context(context, context->state);
1843 		}
1844 	}
1845 	BUG_ON(context->in_syscall || context->name_count);
1846 
1847 	if (!audit_enabled)
1848 		return;
1849 
1850 	context->arch	    = arch;
1851 	context->major      = major;
1852 	context->argv[0]    = a1;
1853 	context->argv[1]    = a2;
1854 	context->argv[2]    = a3;
1855 	context->argv[3]    = a4;
1856 
1857 	state = context->state;
1858 	context->dummy = !audit_n_rules;
1859 	if (!context->dummy && state == AUDIT_BUILD_CONTEXT) {
1860 		context->prio = 0;
1861 		state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
1862 	}
1863 	if (state == AUDIT_DISABLED)
1864 		return;
1865 
1866 	context->serial     = 0;
1867 	context->ctime      = CURRENT_TIME;
1868 	context->in_syscall = 1;
1869 	context->current_state  = state;
1870 	context->ppid       = 0;
1871 }
1872 
1873 /**
1874  * audit_syscall_exit - deallocate audit context after a system call
1875  * @success: success value of the syscall
1876  * @return_code: return value of the syscall
1877  *
1878  * Tear down after system call.  If the audit context has been marked as
1879  * auditable (either because of the AUDIT_RECORD_CONTEXT state from
1880  * filtering, or because some other part of the kernel wrote an audit
1881  * message), then write out the syscall information.  In call cases,
1882  * free the names stored from getname().
1883  */
__audit_syscall_exit(int success,long return_code)1884 void __audit_syscall_exit(int success, long return_code)
1885 {
1886 	struct task_struct *tsk = current;
1887 	struct audit_context *context;
1888 
1889 	if (success)
1890 		success = AUDITSC_SUCCESS;
1891 	else
1892 		success = AUDITSC_FAILURE;
1893 
1894 	context = audit_get_context(tsk, success, return_code);
1895 	if (!context)
1896 		return;
1897 
1898 	if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT)
1899 		audit_log_exit(context, tsk);
1900 
1901 	context->in_syscall = 0;
1902 	context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
1903 
1904 	if (!list_empty(&context->killed_trees))
1905 		audit_kill_trees(&context->killed_trees);
1906 
1907 	if (context->previous) {
1908 		struct audit_context *new_context = context->previous;
1909 		context->previous  = NULL;
1910 		audit_free_context(context);
1911 		tsk->audit_context = new_context;
1912 	} else {
1913 		audit_free_names(context);
1914 		unroll_tree_refs(context, NULL, 0);
1915 		audit_free_aux(context);
1916 		context->aux = NULL;
1917 		context->aux_pids = NULL;
1918 		context->target_pid = 0;
1919 		context->target_sid = 0;
1920 		context->sockaddr_len = 0;
1921 		context->type = 0;
1922 		context->fds[0] = -1;
1923 		if (context->state != AUDIT_RECORD_CONTEXT) {
1924 			kfree(context->filterkey);
1925 			context->filterkey = NULL;
1926 		}
1927 		tsk->audit_context = context;
1928 	}
1929 }
1930 
handle_one(const struct inode * inode)1931 static inline void handle_one(const struct inode *inode)
1932 {
1933 #ifdef CONFIG_AUDIT_TREE
1934 	struct audit_context *context;
1935 	struct audit_tree_refs *p;
1936 	struct audit_chunk *chunk;
1937 	int count;
1938 	if (likely(hlist_empty(&inode->i_fsnotify_marks)))
1939 		return;
1940 	context = current->audit_context;
1941 	p = context->trees;
1942 	count = context->tree_count;
1943 	rcu_read_lock();
1944 	chunk = audit_tree_lookup(inode);
1945 	rcu_read_unlock();
1946 	if (!chunk)
1947 		return;
1948 	if (likely(put_tree_ref(context, chunk)))
1949 		return;
1950 	if (unlikely(!grow_tree_refs(context))) {
1951 		printk(KERN_WARNING "out of memory, audit has lost a tree reference\n");
1952 		audit_set_auditable(context);
1953 		audit_put_chunk(chunk);
1954 		unroll_tree_refs(context, p, count);
1955 		return;
1956 	}
1957 	put_tree_ref(context, chunk);
1958 #endif
1959 }
1960 
handle_path(const struct dentry * dentry)1961 static void handle_path(const struct dentry *dentry)
1962 {
1963 #ifdef CONFIG_AUDIT_TREE
1964 	struct audit_context *context;
1965 	struct audit_tree_refs *p;
1966 	const struct dentry *d, *parent;
1967 	struct audit_chunk *drop;
1968 	unsigned long seq;
1969 	int count;
1970 
1971 	context = current->audit_context;
1972 	p = context->trees;
1973 	count = context->tree_count;
1974 retry:
1975 	drop = NULL;
1976 	d = dentry;
1977 	rcu_read_lock();
1978 	seq = read_seqbegin(&rename_lock);
1979 	for(;;) {
1980 		struct inode *inode = d->d_inode;
1981 		if (inode && unlikely(!hlist_empty(&inode->i_fsnotify_marks))) {
1982 			struct audit_chunk *chunk;
1983 			chunk = audit_tree_lookup(inode);
1984 			if (chunk) {
1985 				if (unlikely(!put_tree_ref(context, chunk))) {
1986 					drop = chunk;
1987 					break;
1988 				}
1989 			}
1990 		}
1991 		parent = d->d_parent;
1992 		if (parent == d)
1993 			break;
1994 		d = parent;
1995 	}
1996 	if (unlikely(read_seqretry(&rename_lock, seq) || drop)) {  /* in this order */
1997 		rcu_read_unlock();
1998 		if (!drop) {
1999 			/* just a race with rename */
2000 			unroll_tree_refs(context, p, count);
2001 			goto retry;
2002 		}
2003 		audit_put_chunk(drop);
2004 		if (grow_tree_refs(context)) {
2005 			/* OK, got more space */
2006 			unroll_tree_refs(context, p, count);
2007 			goto retry;
2008 		}
2009 		/* too bad */
2010 		printk(KERN_WARNING
2011 			"out of memory, audit has lost a tree reference\n");
2012 		unroll_tree_refs(context, p, count);
2013 		audit_set_auditable(context);
2014 		return;
2015 	}
2016 	rcu_read_unlock();
2017 #endif
2018 }
2019 
audit_alloc_name(struct audit_context * context)2020 static struct audit_names *audit_alloc_name(struct audit_context *context)
2021 {
2022 	struct audit_names *aname;
2023 
2024 	if (context->name_count < AUDIT_NAMES) {
2025 		aname = &context->preallocated_names[context->name_count];
2026 		memset(aname, 0, sizeof(*aname));
2027 	} else {
2028 		aname = kzalloc(sizeof(*aname), GFP_NOFS);
2029 		if (!aname)
2030 			return NULL;
2031 		aname->should_free = true;
2032 	}
2033 
2034 	aname->ino = (unsigned long)-1;
2035 	list_add_tail(&aname->list, &context->names_list);
2036 
2037 	context->name_count++;
2038 #if AUDIT_DEBUG
2039 	context->ino_count++;
2040 #endif
2041 	return aname;
2042 }
2043 
2044 /**
2045  * audit_getname - add a name to the list
2046  * @name: name to add
2047  *
2048  * Add a name to the list of audit names for this context.
2049  * Called from fs/namei.c:getname().
2050  */
__audit_getname(const char * name)2051 void __audit_getname(const char *name)
2052 {
2053 	struct audit_context *context = current->audit_context;
2054 	struct audit_names *n;
2055 
2056 	if (!context->in_syscall) {
2057 #if AUDIT_DEBUG == 2
2058 		printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)\n",
2059 		       __FILE__, __LINE__, context->serial, name);
2060 		dump_stack();
2061 #endif
2062 		return;
2063 	}
2064 
2065 	n = audit_alloc_name(context);
2066 	if (!n)
2067 		return;
2068 
2069 	n->name = name;
2070 	n->name_len = AUDIT_NAME_FULL;
2071 	n->name_put = true;
2072 
2073 	if (!context->pwd.dentry)
2074 		get_fs_pwd(current->fs, &context->pwd);
2075 }
2076 
2077 /* audit_putname - intercept a putname request
2078  * @name: name to intercept and delay for putname
2079  *
2080  * If we have stored the name from getname in the audit context,
2081  * then we delay the putname until syscall exit.
2082  * Called from include/linux/fs.h:putname().
2083  */
audit_putname(const char * name)2084 void audit_putname(const char *name)
2085 {
2086 	struct audit_context *context = current->audit_context;
2087 
2088 	BUG_ON(!context);
2089 	if (!context->in_syscall) {
2090 #if AUDIT_DEBUG == 2
2091 		printk(KERN_ERR "%s:%d(:%d): __putname(%p)\n",
2092 		       __FILE__, __LINE__, context->serial, name);
2093 		if (context->name_count) {
2094 			struct audit_names *n;
2095 			int i;
2096 
2097 			list_for_each_entry(n, &context->names_list, list)
2098 				printk(KERN_ERR "name[%d] = %p = %s\n", i,
2099 				       n->name, n->name ?: "(null)");
2100 			}
2101 #endif
2102 		__putname(name);
2103 	}
2104 #if AUDIT_DEBUG
2105 	else {
2106 		++context->put_count;
2107 		if (context->put_count > context->name_count) {
2108 			printk(KERN_ERR "%s:%d(:%d): major=%d"
2109 			       " in_syscall=%d putname(%p) name_count=%d"
2110 			       " put_count=%d\n",
2111 			       __FILE__, __LINE__,
2112 			       context->serial, context->major,
2113 			       context->in_syscall, name, context->name_count,
2114 			       context->put_count);
2115 			dump_stack();
2116 		}
2117 	}
2118 #endif
2119 }
2120 
audit_copy_fcaps(struct audit_names * name,const struct dentry * dentry)2121 static inline int audit_copy_fcaps(struct audit_names *name, const struct dentry *dentry)
2122 {
2123 	struct cpu_vfs_cap_data caps;
2124 	int rc;
2125 
2126 	if (!dentry)
2127 		return 0;
2128 
2129 	rc = get_vfs_caps_from_disk(dentry, &caps);
2130 	if (rc)
2131 		return rc;
2132 
2133 	name->fcap.permitted = caps.permitted;
2134 	name->fcap.inheritable = caps.inheritable;
2135 	name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2136 	name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
2137 
2138 	return 0;
2139 }
2140 
2141 
2142 /* Copy inode data into an audit_names. */
audit_copy_inode(struct audit_names * name,const struct dentry * dentry,const struct inode * inode)2143 static void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
2144 			     const struct inode *inode)
2145 {
2146 	name->ino   = inode->i_ino;
2147 	name->dev   = inode->i_sb->s_dev;
2148 	name->mode  = inode->i_mode;
2149 	name->uid   = inode->i_uid;
2150 	name->gid   = inode->i_gid;
2151 	name->rdev  = inode->i_rdev;
2152 	security_inode_getsecid(inode, &name->osid);
2153 	audit_copy_fcaps(name, dentry);
2154 }
2155 
2156 /**
2157  * audit_inode - store the inode and device from a lookup
2158  * @name: name being audited
2159  * @dentry: dentry being audited
2160  *
2161  * Called from fs/namei.c:path_lookup().
2162  */
__audit_inode(const char * name,const struct dentry * dentry)2163 void __audit_inode(const char *name, const struct dentry *dentry)
2164 {
2165 	struct audit_context *context = current->audit_context;
2166 	const struct inode *inode = dentry->d_inode;
2167 	struct audit_names *n;
2168 
2169 	if (!context->in_syscall)
2170 		return;
2171 
2172 	list_for_each_entry_reverse(n, &context->names_list, list) {
2173 		if (n->name && (n->name == name))
2174 			goto out;
2175 	}
2176 
2177 	/* unable to find the name from a previous getname() */
2178 	n = audit_alloc_name(context);
2179 	if (!n)
2180 		return;
2181 out:
2182 	handle_path(dentry);
2183 	audit_copy_inode(n, dentry, inode);
2184 }
2185 
2186 /**
2187  * audit_inode_child - collect inode info for created/removed objects
2188  * @dentry: dentry being audited
2189  * @parent: inode of dentry parent
2190  *
2191  * For syscalls that create or remove filesystem objects, audit_inode
2192  * can only collect information for the filesystem object's parent.
2193  * This call updates the audit context with the child's information.
2194  * Syscalls that create a new filesystem object must be hooked after
2195  * the object is created.  Syscalls that remove a filesystem object
2196  * must be hooked prior, in order to capture the target inode during
2197  * unsuccessful attempts.
2198  */
__audit_inode_child(const struct dentry * dentry,const struct inode * parent)2199 void __audit_inode_child(const struct dentry *dentry,
2200 			 const struct inode *parent)
2201 {
2202 	struct audit_context *context = current->audit_context;
2203 	const char *found_parent = NULL, *found_child = NULL;
2204 	const struct inode *inode = dentry->d_inode;
2205 	const char *dname = dentry->d_name.name;
2206 	struct audit_names *n;
2207 	int dirlen = 0;
2208 
2209 	if (!context->in_syscall)
2210 		return;
2211 
2212 	if (inode)
2213 		handle_one(inode);
2214 
2215 	/* parent is more likely, look for it first */
2216 	list_for_each_entry(n, &context->names_list, list) {
2217 		if (!n->name)
2218 			continue;
2219 
2220 		if (n->ino == parent->i_ino &&
2221 		    !audit_compare_dname_path(dname, n->name, &dirlen)) {
2222 			n->name_len = dirlen; /* update parent data in place */
2223 			found_parent = n->name;
2224 			goto add_names;
2225 		}
2226 	}
2227 
2228 	/* no matching parent, look for matching child */
2229 	list_for_each_entry(n, &context->names_list, list) {
2230 		if (!n->name)
2231 			continue;
2232 
2233 		/* strcmp() is the more likely scenario */
2234 		if (!strcmp(dname, n->name) ||
2235 		     !audit_compare_dname_path(dname, n->name, &dirlen)) {
2236 			if (inode)
2237 				audit_copy_inode(n, NULL, inode);
2238 			else
2239 				n->ino = (unsigned long)-1;
2240 			found_child = n->name;
2241 			goto add_names;
2242 		}
2243 	}
2244 
2245 add_names:
2246 	if (!found_parent) {
2247 		n = audit_alloc_name(context);
2248 		if (!n)
2249 			return;
2250 		audit_copy_inode(n, NULL, parent);
2251 	}
2252 
2253 	if (!found_child) {
2254 		n = audit_alloc_name(context);
2255 		if (!n)
2256 			return;
2257 
2258 		/* Re-use the name belonging to the slot for a matching parent
2259 		 * directory. All names for this context are relinquished in
2260 		 * audit_free_names() */
2261 		if (found_parent) {
2262 			n->name = found_parent;
2263 			n->name_len = AUDIT_NAME_FULL;
2264 			/* don't call __putname() */
2265 			n->name_put = false;
2266 		}
2267 
2268 		if (inode)
2269 			audit_copy_inode(n, NULL, inode);
2270 	}
2271 }
2272 EXPORT_SYMBOL_GPL(__audit_inode_child);
2273 
2274 /**
2275  * auditsc_get_stamp - get local copies of audit_context values
2276  * @ctx: audit_context for the task
2277  * @t: timespec to store time recorded in the audit_context
2278  * @serial: serial value that is recorded in the audit_context
2279  *
2280  * Also sets the context as auditable.
2281  */
auditsc_get_stamp(struct audit_context * ctx,struct timespec * t,unsigned int * serial)2282 int auditsc_get_stamp(struct audit_context *ctx,
2283 		       struct timespec *t, unsigned int *serial)
2284 {
2285 	if (!ctx->in_syscall)
2286 		return 0;
2287 	if (!ctx->serial)
2288 		ctx->serial = audit_serial();
2289 	t->tv_sec  = ctx->ctime.tv_sec;
2290 	t->tv_nsec = ctx->ctime.tv_nsec;
2291 	*serial    = ctx->serial;
2292 	if (!ctx->prio) {
2293 		ctx->prio = 1;
2294 		ctx->current_state = AUDIT_RECORD_CONTEXT;
2295 	}
2296 	return 1;
2297 }
2298 
2299 /* global counter which is incremented every time something logs in */
2300 static atomic_t session_id = ATOMIC_INIT(0);
2301 
2302 /**
2303  * audit_set_loginuid - set current task's audit_context loginuid
2304  * @loginuid: loginuid value
2305  *
2306  * Returns 0.
2307  *
2308  * Called (set) from fs/proc/base.c::proc_loginuid_write().
2309  */
audit_set_loginuid(uid_t loginuid)2310 int audit_set_loginuid(uid_t loginuid)
2311 {
2312 	struct task_struct *task = current;
2313 	struct audit_context *context = task->audit_context;
2314 	unsigned int sessionid;
2315 
2316 #ifdef CONFIG_AUDIT_LOGINUID_IMMUTABLE
2317 	if (task->loginuid != -1)
2318 		return -EPERM;
2319 #else /* CONFIG_AUDIT_LOGINUID_IMMUTABLE */
2320 	if (!capable(CAP_AUDIT_CONTROL))
2321 		return -EPERM;
2322 #endif  /* CONFIG_AUDIT_LOGINUID_IMMUTABLE */
2323 
2324 	sessionid = atomic_inc_return(&session_id);
2325 	if (context && context->in_syscall) {
2326 		struct audit_buffer *ab;
2327 
2328 		ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
2329 		if (ab) {
2330 			audit_log_format(ab, "login pid=%d uid=%u "
2331 				"old auid=%u new auid=%u"
2332 				" old ses=%u new ses=%u",
2333 				task->pid, task_uid(task),
2334 				task->loginuid, loginuid,
2335 				task->sessionid, sessionid);
2336 			audit_log_end(ab);
2337 		}
2338 	}
2339 	task->sessionid = sessionid;
2340 	task->loginuid = loginuid;
2341 	return 0;
2342 }
2343 
2344 /**
2345  * __audit_mq_open - record audit data for a POSIX MQ open
2346  * @oflag: open flag
2347  * @mode: mode bits
2348  * @attr: queue attributes
2349  *
2350  */
__audit_mq_open(int oflag,umode_t mode,struct mq_attr * attr)2351 void __audit_mq_open(int oflag, umode_t mode, struct mq_attr *attr)
2352 {
2353 	struct audit_context *context = current->audit_context;
2354 
2355 	if (attr)
2356 		memcpy(&context->mq_open.attr, attr, sizeof(struct mq_attr));
2357 	else
2358 		memset(&context->mq_open.attr, 0, sizeof(struct mq_attr));
2359 
2360 	context->mq_open.oflag = oflag;
2361 	context->mq_open.mode = mode;
2362 
2363 	context->type = AUDIT_MQ_OPEN;
2364 }
2365 
2366 /**
2367  * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive
2368  * @mqdes: MQ descriptor
2369  * @msg_len: Message length
2370  * @msg_prio: Message priority
2371  * @abs_timeout: Message timeout in absolute time
2372  *
2373  */
__audit_mq_sendrecv(mqd_t mqdes,size_t msg_len,unsigned int msg_prio,const struct timespec * abs_timeout)2374 void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio,
2375 			const struct timespec *abs_timeout)
2376 {
2377 	struct audit_context *context = current->audit_context;
2378 	struct timespec *p = &context->mq_sendrecv.abs_timeout;
2379 
2380 	if (abs_timeout)
2381 		memcpy(p, abs_timeout, sizeof(struct timespec));
2382 	else
2383 		memset(p, 0, sizeof(struct timespec));
2384 
2385 	context->mq_sendrecv.mqdes = mqdes;
2386 	context->mq_sendrecv.msg_len = msg_len;
2387 	context->mq_sendrecv.msg_prio = msg_prio;
2388 
2389 	context->type = AUDIT_MQ_SENDRECV;
2390 }
2391 
2392 /**
2393  * __audit_mq_notify - record audit data for a POSIX MQ notify
2394  * @mqdes: MQ descriptor
2395  * @notification: Notification event
2396  *
2397  */
2398 
__audit_mq_notify(mqd_t mqdes,const struct sigevent * notification)2399 void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification)
2400 {
2401 	struct audit_context *context = current->audit_context;
2402 
2403 	if (notification)
2404 		context->mq_notify.sigev_signo = notification->sigev_signo;
2405 	else
2406 		context->mq_notify.sigev_signo = 0;
2407 
2408 	context->mq_notify.mqdes = mqdes;
2409 	context->type = AUDIT_MQ_NOTIFY;
2410 }
2411 
2412 /**
2413  * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute
2414  * @mqdes: MQ descriptor
2415  * @mqstat: MQ flags
2416  *
2417  */
__audit_mq_getsetattr(mqd_t mqdes,struct mq_attr * mqstat)2418 void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
2419 {
2420 	struct audit_context *context = current->audit_context;
2421 	context->mq_getsetattr.mqdes = mqdes;
2422 	context->mq_getsetattr.mqstat = *mqstat;
2423 	context->type = AUDIT_MQ_GETSETATTR;
2424 }
2425 
2426 /**
2427  * audit_ipc_obj - record audit data for ipc object
2428  * @ipcp: ipc permissions
2429  *
2430  */
__audit_ipc_obj(struct kern_ipc_perm * ipcp)2431 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
2432 {
2433 	struct audit_context *context = current->audit_context;
2434 	context->ipc.uid = ipcp->uid;
2435 	context->ipc.gid = ipcp->gid;
2436 	context->ipc.mode = ipcp->mode;
2437 	context->ipc.has_perm = 0;
2438 	security_ipc_getsecid(ipcp, &context->ipc.osid);
2439 	context->type = AUDIT_IPC;
2440 }
2441 
2442 /**
2443  * audit_ipc_set_perm - record audit data for new ipc permissions
2444  * @qbytes: msgq bytes
2445  * @uid: msgq user id
2446  * @gid: msgq group id
2447  * @mode: msgq mode (permissions)
2448  *
2449  * Called only after audit_ipc_obj().
2450  */
__audit_ipc_set_perm(unsigned long qbytes,uid_t uid,gid_t gid,umode_t mode)2451 void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode)
2452 {
2453 	struct audit_context *context = current->audit_context;
2454 
2455 	context->ipc.qbytes = qbytes;
2456 	context->ipc.perm_uid = uid;
2457 	context->ipc.perm_gid = gid;
2458 	context->ipc.perm_mode = mode;
2459 	context->ipc.has_perm = 1;
2460 }
2461 
__audit_bprm(struct linux_binprm * bprm)2462 int __audit_bprm(struct linux_binprm *bprm)
2463 {
2464 	struct audit_aux_data_execve *ax;
2465 	struct audit_context *context = current->audit_context;
2466 
2467 	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2468 	if (!ax)
2469 		return -ENOMEM;
2470 
2471 	ax->argc = bprm->argc;
2472 	ax->envc = bprm->envc;
2473 	ax->mm = bprm->mm;
2474 	ax->d.type = AUDIT_EXECVE;
2475 	ax->d.next = context->aux;
2476 	context->aux = (void *)ax;
2477 	return 0;
2478 }
2479 
2480 
2481 /**
2482  * audit_socketcall - record audit data for sys_socketcall
2483  * @nargs: number of args
2484  * @args: args array
2485  *
2486  */
__audit_socketcall(int nargs,unsigned long * args)2487 void __audit_socketcall(int nargs, unsigned long *args)
2488 {
2489 	struct audit_context *context = current->audit_context;
2490 
2491 	context->type = AUDIT_SOCKETCALL;
2492 	context->socketcall.nargs = nargs;
2493 	memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long));
2494 }
2495 
2496 /**
2497  * __audit_fd_pair - record audit data for pipe and socketpair
2498  * @fd1: the first file descriptor
2499  * @fd2: the second file descriptor
2500  *
2501  */
__audit_fd_pair(int fd1,int fd2)2502 void __audit_fd_pair(int fd1, int fd2)
2503 {
2504 	struct audit_context *context = current->audit_context;
2505 	context->fds[0] = fd1;
2506 	context->fds[1] = fd2;
2507 }
2508 
2509 /**
2510  * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
2511  * @len: data length in user space
2512  * @a: data address in kernel space
2513  *
2514  * Returns 0 for success or NULL context or < 0 on error.
2515  */
__audit_sockaddr(int len,void * a)2516 int __audit_sockaddr(int len, void *a)
2517 {
2518 	struct audit_context *context = current->audit_context;
2519 
2520 	if (!context->sockaddr) {
2521 		void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL);
2522 		if (!p)
2523 			return -ENOMEM;
2524 		context->sockaddr = p;
2525 	}
2526 
2527 	context->sockaddr_len = len;
2528 	memcpy(context->sockaddr, a, len);
2529 	return 0;
2530 }
2531 
__audit_ptrace(struct task_struct * t)2532 void __audit_ptrace(struct task_struct *t)
2533 {
2534 	struct audit_context *context = current->audit_context;
2535 
2536 	context->target_pid = t->pid;
2537 	context->target_auid = audit_get_loginuid(t);
2538 	context->target_uid = task_uid(t);
2539 	context->target_sessionid = audit_get_sessionid(t);
2540 	security_task_getsecid(t, &context->target_sid);
2541 	memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
2542 }
2543 
2544 /**
2545  * audit_signal_info - record signal info for shutting down audit subsystem
2546  * @sig: signal value
2547  * @t: task being signaled
2548  *
2549  * If the audit subsystem is being terminated, record the task (pid)
2550  * and uid that is doing that.
2551  */
__audit_signal_info(int sig,struct task_struct * t)2552 int __audit_signal_info(int sig, struct task_struct *t)
2553 {
2554 	struct audit_aux_data_pids *axp;
2555 	struct task_struct *tsk = current;
2556 	struct audit_context *ctx = tsk->audit_context;
2557 	uid_t uid = current_uid(), t_uid = task_uid(t);
2558 
2559 	if (audit_pid && t->tgid == audit_pid) {
2560 		if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) {
2561 			audit_sig_pid = tsk->pid;
2562 			if (tsk->loginuid != -1)
2563 				audit_sig_uid = tsk->loginuid;
2564 			else
2565 				audit_sig_uid = uid;
2566 			security_task_getsecid(tsk, &audit_sig_sid);
2567 		}
2568 		if (!audit_signals || audit_dummy_context())
2569 			return 0;
2570 	}
2571 
2572 	/* optimize the common case by putting first signal recipient directly
2573 	 * in audit_context */
2574 	if (!ctx->target_pid) {
2575 		ctx->target_pid = t->tgid;
2576 		ctx->target_auid = audit_get_loginuid(t);
2577 		ctx->target_uid = t_uid;
2578 		ctx->target_sessionid = audit_get_sessionid(t);
2579 		security_task_getsecid(t, &ctx->target_sid);
2580 		memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
2581 		return 0;
2582 	}
2583 
2584 	axp = (void *)ctx->aux_pids;
2585 	if (!axp || axp->pid_count == AUDIT_AUX_PIDS) {
2586 		axp = kzalloc(sizeof(*axp), GFP_ATOMIC);
2587 		if (!axp)
2588 			return -ENOMEM;
2589 
2590 		axp->d.type = AUDIT_OBJ_PID;
2591 		axp->d.next = ctx->aux_pids;
2592 		ctx->aux_pids = (void *)axp;
2593 	}
2594 	BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);
2595 
2596 	axp->target_pid[axp->pid_count] = t->tgid;
2597 	axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
2598 	axp->target_uid[axp->pid_count] = t_uid;
2599 	axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
2600 	security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
2601 	memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
2602 	axp->pid_count++;
2603 
2604 	return 0;
2605 }
2606 
2607 /**
2608  * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps
2609  * @bprm: pointer to the bprm being processed
2610  * @new: the proposed new credentials
2611  * @old: the old credentials
2612  *
2613  * Simply check if the proc already has the caps given by the file and if not
2614  * store the priv escalation info for later auditing at the end of the syscall
2615  *
2616  * -Eric
2617  */
__audit_log_bprm_fcaps(struct linux_binprm * bprm,const struct cred * new,const struct cred * old)2618 int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
2619 			   const struct cred *new, const struct cred *old)
2620 {
2621 	struct audit_aux_data_bprm_fcaps *ax;
2622 	struct audit_context *context = current->audit_context;
2623 	struct cpu_vfs_cap_data vcaps;
2624 	struct dentry *dentry;
2625 
2626 	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
2627 	if (!ax)
2628 		return -ENOMEM;
2629 
2630 	ax->d.type = AUDIT_BPRM_FCAPS;
2631 	ax->d.next = context->aux;
2632 	context->aux = (void *)ax;
2633 
2634 	dentry = dget(bprm->file->f_dentry);
2635 	get_vfs_caps_from_disk(dentry, &vcaps);
2636 	dput(dentry);
2637 
2638 	ax->fcap.permitted = vcaps.permitted;
2639 	ax->fcap.inheritable = vcaps.inheritable;
2640 	ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2641 	ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT;
2642 
2643 	ax->old_pcap.permitted   = old->cap_permitted;
2644 	ax->old_pcap.inheritable = old->cap_inheritable;
2645 	ax->old_pcap.effective   = old->cap_effective;
2646 
2647 	ax->new_pcap.permitted   = new->cap_permitted;
2648 	ax->new_pcap.inheritable = new->cap_inheritable;
2649 	ax->new_pcap.effective   = new->cap_effective;
2650 	return 0;
2651 }
2652 
2653 /**
2654  * __audit_log_capset - store information about the arguments to the capset syscall
2655  * @pid: target pid of the capset call
2656  * @new: the new credentials
2657  * @old: the old (current) credentials
2658  *
2659  * Record the aguments userspace sent to sys_capset for later printing by the
2660  * audit system if applicable
2661  */
__audit_log_capset(pid_t pid,const struct cred * new,const struct cred * old)2662 void __audit_log_capset(pid_t pid,
2663 		       const struct cred *new, const struct cred *old)
2664 {
2665 	struct audit_context *context = current->audit_context;
2666 	context->capset.pid = pid;
2667 	context->capset.cap.effective   = new->cap_effective;
2668 	context->capset.cap.inheritable = new->cap_effective;
2669 	context->capset.cap.permitted   = new->cap_permitted;
2670 	context->type = AUDIT_CAPSET;
2671 }
2672 
__audit_mmap_fd(int fd,int flags)2673 void __audit_mmap_fd(int fd, int flags)
2674 {
2675 	struct audit_context *context = current->audit_context;
2676 	context->mmap.fd = fd;
2677 	context->mmap.flags = flags;
2678 	context->type = AUDIT_MMAP;
2679 }
2680 
audit_log_abend(struct audit_buffer * ab,char * reason,long signr)2681 static void audit_log_abend(struct audit_buffer *ab, char *reason, long signr)
2682 {
2683 	uid_t auid, uid;
2684 	gid_t gid;
2685 	unsigned int sessionid;
2686 
2687 	auid = audit_get_loginuid(current);
2688 	sessionid = audit_get_sessionid(current);
2689 	current_uid_gid(&uid, &gid);
2690 
2691 	audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
2692 			 auid, uid, gid, sessionid);
2693 	audit_log_task_context(ab);
2694 	audit_log_format(ab, " pid=%d comm=", current->pid);
2695 	audit_log_untrustedstring(ab, current->comm);
2696 	audit_log_format(ab, " reason=");
2697 	audit_log_string(ab, reason);
2698 	audit_log_format(ab, " sig=%ld", signr);
2699 }
2700 /**
2701  * audit_core_dumps - record information about processes that end abnormally
2702  * @signr: signal value
2703  *
2704  * If a process ends with a core dump, something fishy is going on and we
2705  * should record the event for investigation.
2706  */
audit_core_dumps(long signr)2707 void audit_core_dumps(long signr)
2708 {
2709 	struct audit_buffer *ab;
2710 
2711 	if (!audit_enabled)
2712 		return;
2713 
2714 	if (signr == SIGQUIT)	/* don't care for those */
2715 		return;
2716 
2717 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
2718 	audit_log_abend(ab, "memory violation", signr);
2719 	audit_log_end(ab);
2720 }
2721 
__audit_seccomp(unsigned long syscall)2722 void __audit_seccomp(unsigned long syscall)
2723 {
2724 	struct audit_buffer *ab;
2725 
2726 	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
2727 	audit_log_abend(ab, "seccomp", SIGKILL);
2728 	audit_log_format(ab, " syscall=%ld", syscall);
2729 	audit_log_end(ab);
2730 }
2731 
audit_killed_trees(void)2732 struct list_head *audit_killed_trees(void)
2733 {
2734 	struct audit_context *ctx = current->audit_context;
2735 	if (likely(!ctx || !ctx->in_syscall))
2736 		return NULL;
2737 	return &ctx->killed_trees;
2738 }
2739