1 /*
2  * AppArmor security module
3  *
4  * This file contains AppArmor functions for unpacking policy loaded from
5  * userspace.
6  *
7  * Copyright (C) 1998-2008 Novell/SUSE
8  * Copyright 2009-2010 Canonical Ltd.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation, version 2 of the
13  * License.
14  *
15  * AppArmor uses a serialized binary format for loading policy. To find
16  * policy format documentation see Documentation/admin-guide/LSM/apparmor.rst
17  * All policy is validated before it is used.
18  */
19 
20 #include <asm/unaligned.h>
21 #include <linux/ctype.h>
22 #include <linux/errno.h>
23 
24 #include "include/apparmor.h"
25 #include "include/audit.h"
26 #include "include/context.h"
27 #include "include/crypto.h"
28 #include "include/match.h"
29 #include "include/path.h"
30 #include "include/policy.h"
31 #include "include/policy_unpack.h"
32 
33 #define K_ABI_MASK 0x3ff
34 #define FORCE_COMPLAIN_FLAG 0x800
35 #define VERSION_LT(X, Y) (((X) & K_ABI_MASK) < ((Y) & K_ABI_MASK))
36 #define VERSION_GT(X, Y) (((X) & K_ABI_MASK) > ((Y) & K_ABI_MASK))
37 
38 #define v5	5	/* base version */
39 #define v6	6	/* per entry policydb mediation check */
40 #define v7	7	/* full network masking */
41 
42 /*
43  * The AppArmor interface treats data as a type byte followed by the
44  * actual data.  The interface has the notion of a a named entry
45  * which has a name (AA_NAME typecode followed by name string) followed by
46  * the entries typecode and data.  Named types allow for optional
47  * elements and extensions to be added and tested for without breaking
48  * backwards compatibility.
49  */
50 
51 enum aa_code {
52 	AA_U8,
53 	AA_U16,
54 	AA_U32,
55 	AA_U64,
56 	AA_NAME,		/* same as string except it is items name */
57 	AA_STRING,
58 	AA_BLOB,
59 	AA_STRUCT,
60 	AA_STRUCTEND,
61 	AA_LIST,
62 	AA_LISTEND,
63 	AA_ARRAY,
64 	AA_ARRAYEND,
65 };
66 
67 /*
68  * aa_ext is the read of the buffer containing the serialized profile.  The
69  * data is copied into a kernel buffer in apparmorfs and then handed off to
70  * the unpack routines.
71  */
72 struct aa_ext {
73 	void *start;
74 	void *end;
75 	void *pos;		/* pointer to current position in the buffer */
76 	u32 version;
77 };
78 
79 /* audit callback for unpack fields */
80 static void audit_cb(struct audit_buffer *ab, void *va)
81 {
82 	struct common_audit_data *sa = va;
83 
84 	if (aad(sa)->iface.ns) {
85 		audit_log_format(ab, " ns=");
86 		audit_log_untrustedstring(ab, aad(sa)->iface.ns);
87 	}
88 	if (aad(sa)->name) {
89 		audit_log_format(ab, " name=");
90 		audit_log_untrustedstring(ab, aad(sa)->name);
91 	}
92 	if (aad(sa)->iface.pos)
93 		audit_log_format(ab, " offset=%ld", aad(sa)->iface.pos);
94 }
95 
96 /**
97  * audit_iface - do audit message for policy unpacking/load/replace/remove
98  * @new: profile if it has been allocated (MAYBE NULL)
99  * @ns_name: name of the ns the profile is to be loaded to (MAY BE NULL)
100  * @name: name of the profile being manipulated (MAYBE NULL)
101  * @info: any extra info about the failure (MAYBE NULL)
102  * @e: buffer position info
103  * @error: error code
104  *
105  * Returns: %0 or error
106  */
107 static int audit_iface(struct aa_profile *new, const char *ns_name,
108 		       const char *name, const char *info, struct aa_ext *e,
109 		       int error)
110 {
111 	struct aa_profile *profile = labels_profile(aa_current_raw_label());
112 	DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, NULL);
113 	if (e)
114 		aad(&sa)->iface.pos = e->pos - e->start;
115 	aad(&sa)->iface.ns = ns_name;
116 	if (new)
117 		aad(&sa)->name = new->base.hname;
118 	else
119 		aad(&sa)->name = name;
120 	aad(&sa)->info = info;
121 	aad(&sa)->error = error;
122 
123 	return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb);
124 }
125 
126 void __aa_loaddata_update(struct aa_loaddata *data, long revision)
127 {
128 	AA_BUG(!data);
129 	AA_BUG(!data->ns);
130 	AA_BUG(!data->dents[AAFS_LOADDATA_REVISION]);
131 	AA_BUG(!mutex_is_locked(&data->ns->lock));
132 	AA_BUG(data->revision > revision);
133 
134 	data->revision = revision;
135 	d_inode(data->dents[AAFS_LOADDATA_DIR])->i_mtime =
136 		current_time(d_inode(data->dents[AAFS_LOADDATA_DIR]));
137 	d_inode(data->dents[AAFS_LOADDATA_REVISION])->i_mtime =
138 		current_time(d_inode(data->dents[AAFS_LOADDATA_REVISION]));
139 }
140 
141 bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r)
142 {
143 	if (l->size != r->size)
144 		return false;
145 	if (aa_g_hash_policy && memcmp(l->hash, r->hash, aa_hash_size()) != 0)
146 		return false;
147 	return memcmp(l->data, r->data, r->size) == 0;
148 }
149 
150 /*
151  * need to take the ns mutex lock which is NOT safe most places that
152  * put_loaddata is called, so we have to delay freeing it
153  */
154 static void do_loaddata_free(struct work_struct *work)
155 {
156 	struct aa_loaddata *d = container_of(work, struct aa_loaddata, work);
157 	struct aa_ns *ns = aa_get_ns(d->ns);
158 
159 	if (ns) {
160 		mutex_lock_nested(&ns->lock, ns->level);
161 		__aa_fs_remove_rawdata(d);
162 		mutex_unlock(&ns->lock);
163 		aa_put_ns(ns);
164 	}
165 
166 	kzfree(d->hash);
167 	kfree(d->name);
168 	kvfree(d);
169 }
170 
171 void aa_loaddata_kref(struct kref *kref)
172 {
173 	struct aa_loaddata *d = container_of(kref, struct aa_loaddata, count);
174 
175 	if (d) {
176 		INIT_WORK(&d->work, do_loaddata_free);
177 		schedule_work(&d->work);
178 	}
179 }
180 
181 struct aa_loaddata *aa_loaddata_alloc(size_t size)
182 {
183 	struct aa_loaddata *d = kvzalloc(sizeof(*d) + size, GFP_KERNEL);
184 
185 	if (d == NULL)
186 		return ERR_PTR(-ENOMEM);
187 	kref_init(&d->count);
188 	INIT_LIST_HEAD(&d->list);
189 
190 	return d;
191 }
192 
193 /* test if read will be in packed data bounds */
194 static bool inbounds(struct aa_ext *e, size_t size)
195 {
196 	return (size <= e->end - e->pos);
197 }
198 
199 /**
200  * aa_u16_chunck - test and do bounds checking for a u16 size based chunk
201  * @e: serialized data read head (NOT NULL)
202  * @chunk: start address for chunk of data (NOT NULL)
203  *
204  * Returns: the size of chunk found with the read head at the end of the chunk.
205  */
206 static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk)
207 {
208 	size_t size = 0;
209 
210 	if (!inbounds(e, sizeof(u16)))
211 		return 0;
212 	size = le16_to_cpu(get_unaligned((__le16 *) e->pos));
213 	e->pos += sizeof(__le16);
214 	if (!inbounds(e, size))
215 		return 0;
216 	*chunk = e->pos;
217 	e->pos += size;
218 	return size;
219 }
220 
221 /* unpack control byte */
222 static bool unpack_X(struct aa_ext *e, enum aa_code code)
223 {
224 	if (!inbounds(e, 1))
225 		return 0;
226 	if (*(u8 *) e->pos != code)
227 		return 0;
228 	e->pos++;
229 	return 1;
230 }
231 
232 /**
233  * unpack_nameX - check is the next element is of type X with a name of @name
234  * @e: serialized data extent information  (NOT NULL)
235  * @code: type code
236  * @name: name to match to the serialized element.  (MAYBE NULL)
237  *
238  * check that the next serialized data element is of type X and has a tag
239  * name @name.  If @name is specified then there must be a matching
240  * name element in the stream.  If @name is NULL any name element will be
241  * skipped and only the typecode will be tested.
242  *
243  * Returns 1 on success (both type code and name tests match) and the read
244  * head is advanced past the headers
245  *
246  * Returns: 0 if either match fails, the read head does not move
247  */
248 static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
249 {
250 	/*
251 	 * May need to reset pos if name or type doesn't match
252 	 */
253 	void *pos = e->pos;
254 	/*
255 	 * Check for presence of a tagname, and if present name size
256 	 * AA_NAME tag value is a u16.
257 	 */
258 	if (unpack_X(e, AA_NAME)) {
259 		char *tag = NULL;
260 		size_t size = unpack_u16_chunk(e, &tag);
261 		/* if a name is specified it must match. otherwise skip tag */
262 		if (name && (!size || strcmp(name, tag)))
263 			goto fail;
264 	} else if (name) {
265 		/* if a name is specified and there is no name tag fail */
266 		goto fail;
267 	}
268 
269 	/* now check if type code matches */
270 	if (unpack_X(e, code))
271 		return 1;
272 
273 fail:
274 	e->pos = pos;
275 	return 0;
276 }
277 
278 static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
279 {
280 	if (unpack_nameX(e, AA_U32, name)) {
281 		if (!inbounds(e, sizeof(u32)))
282 			return 0;
283 		if (data)
284 			*data = le32_to_cpu(get_unaligned((__le32 *) e->pos));
285 		e->pos += sizeof(u32);
286 		return 1;
287 	}
288 	return 0;
289 }
290 
291 static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name)
292 {
293 	if (unpack_nameX(e, AA_U64, name)) {
294 		if (!inbounds(e, sizeof(u64)))
295 			return 0;
296 		if (data)
297 			*data = le64_to_cpu(get_unaligned((__le64 *) e->pos));
298 		e->pos += sizeof(u64);
299 		return 1;
300 	}
301 	return 0;
302 }
303 
304 static size_t unpack_array(struct aa_ext *e, const char *name)
305 {
306 	if (unpack_nameX(e, AA_ARRAY, name)) {
307 		int size;
308 		if (!inbounds(e, sizeof(u16)))
309 			return 0;
310 		size = (int)le16_to_cpu(get_unaligned((__le16 *) e->pos));
311 		e->pos += sizeof(u16);
312 		return size;
313 	}
314 	return 0;
315 }
316 
317 static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
318 {
319 	if (unpack_nameX(e, AA_BLOB, name)) {
320 		u32 size;
321 		if (!inbounds(e, sizeof(u32)))
322 			return 0;
323 		size = le32_to_cpu(get_unaligned((__le32 *) e->pos));
324 		e->pos += sizeof(u32);
325 		if (inbounds(e, (size_t) size)) {
326 			*blob = e->pos;
327 			e->pos += size;
328 			return size;
329 		}
330 	}
331 	return 0;
332 }
333 
334 static int unpack_str(struct aa_ext *e, const char **string, const char *name)
335 {
336 	char *src_str;
337 	size_t size = 0;
338 	void *pos = e->pos;
339 	*string = NULL;
340 	if (unpack_nameX(e, AA_STRING, name)) {
341 		size = unpack_u16_chunk(e, &src_str);
342 		if (size) {
343 			/* strings are null terminated, length is size - 1 */
344 			if (src_str[size - 1] != 0)
345 				goto fail;
346 			*string = src_str;
347 		}
348 	}
349 	return size;
350 
351 fail:
352 	e->pos = pos;
353 	return 0;
354 }
355 
356 static int unpack_strdup(struct aa_ext *e, char **string, const char *name)
357 {
358 	const char *tmp;
359 	void *pos = e->pos;
360 	int res = unpack_str(e, &tmp, name);
361 	*string = NULL;
362 
363 	if (!res)
364 		return 0;
365 
366 	*string = kmemdup(tmp, res, GFP_KERNEL);
367 	if (!*string) {
368 		e->pos = pos;
369 		return 0;
370 	}
371 
372 	return res;
373 }
374 
375 #define DFA_VALID_PERM_MASK		0xffffffff
376 #define DFA_VALID_PERM2_MASK		0xffffffff
377 
378 /**
379  * verify_accept - verify the accept tables of a dfa
380  * @dfa: dfa to verify accept tables of (NOT NULL)
381  * @flags: flags governing dfa
382  *
383  * Returns: 1 if valid accept tables else 0 if error
384  */
385 static bool verify_accept(struct aa_dfa *dfa, int flags)
386 {
387 	int i;
388 
389 	/* verify accept permissions */
390 	for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
391 		int mode = ACCEPT_TABLE(dfa)[i];
392 
393 		if (mode & ~DFA_VALID_PERM_MASK)
394 			return 0;
395 
396 		if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK)
397 			return 0;
398 	}
399 	return 1;
400 }
401 
402 /**
403  * unpack_dfa - unpack a file rule dfa
404  * @e: serialized data extent information (NOT NULL)
405  *
406  * returns dfa or ERR_PTR or NULL if no dfa
407  */
408 static struct aa_dfa *unpack_dfa(struct aa_ext *e)
409 {
410 	char *blob = NULL;
411 	size_t size;
412 	struct aa_dfa *dfa = NULL;
413 
414 	size = unpack_blob(e, &blob, "aadfa");
415 	if (size) {
416 		/*
417 		 * The dfa is aligned with in the blob to 8 bytes
418 		 * from the beginning of the stream.
419 		 * alignment adjust needed by dfa unpack
420 		 */
421 		size_t sz = blob - (char *) e->start -
422 			((e->pos - e->start) & 7);
423 		size_t pad = ALIGN(sz, 8) - sz;
424 		int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) |
425 			TO_ACCEPT2_FLAG(YYTD_DATA32) | DFA_FLAG_VERIFY_STATES;
426 		dfa = aa_dfa_unpack(blob + pad, size - pad, flags);
427 
428 		if (IS_ERR(dfa))
429 			return dfa;
430 
431 		if (!verify_accept(dfa, flags))
432 			goto fail;
433 	}
434 
435 	return dfa;
436 
437 fail:
438 	aa_put_dfa(dfa);
439 	return ERR_PTR(-EPROTO);
440 }
441 
442 /**
443  * unpack_trans_table - unpack a profile transition table
444  * @e: serialized data extent information  (NOT NULL)
445  * @profile: profile to add the accept table to (NOT NULL)
446  *
447  * Returns: 1 if table successfully unpacked
448  */
449 static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile)
450 {
451 	void *saved_pos = e->pos;
452 
453 	/* exec table is optional */
454 	if (unpack_nameX(e, AA_STRUCT, "xtable")) {
455 		int i, size;
456 
457 		size = unpack_array(e, NULL);
458 		/* currently 4 exec bits and entries 0-3 are reserved iupcx */
459 		if (size > 16 - 4)
460 			goto fail;
461 		profile->file.trans.table = kzalloc(sizeof(char *) * size,
462 						    GFP_KERNEL);
463 		if (!profile->file.trans.table)
464 			goto fail;
465 
466 		profile->file.trans.size = size;
467 		for (i = 0; i < size; i++) {
468 			char *str;
469 			int c, j, pos, size2 = unpack_strdup(e, &str, NULL);
470 			/* unpack_strdup verifies that the last character is
471 			 * null termination byte.
472 			 */
473 			if (!size2)
474 				goto fail;
475 			profile->file.trans.table[i] = str;
476 			/* verify that name doesn't start with space */
477 			if (isspace(*str))
478 				goto fail;
479 
480 			/* count internal #  of internal \0 */
481 			for (c = j = 0; j < size2 - 1; j++) {
482 				if (!str[j]) {
483 					pos = j;
484 					c++;
485 				}
486 			}
487 			if (*str == ':') {
488 				/* first character after : must be valid */
489 				if (!str[1])
490 					goto fail;
491 				/* beginning with : requires an embedded \0,
492 				 * verify that exactly 1 internal \0 exists
493 				 * trailing \0 already verified by unpack_strdup
494 				 *
495 				 * convert \0 back to : for label_parse
496 				 */
497 				if (c == 1)
498 					str[pos] = ':';
499 				else if (c > 1)
500 					goto fail;
501 			} else if (c)
502 				/* fail - all other cases with embedded \0 */
503 				goto fail;
504 		}
505 		if (!unpack_nameX(e, AA_ARRAYEND, NULL))
506 			goto fail;
507 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
508 			goto fail;
509 	}
510 	return 1;
511 
512 fail:
513 	aa_free_domain_entries(&profile->file.trans);
514 	e->pos = saved_pos;
515 	return 0;
516 }
517 
518 static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile)
519 {
520 	void *pos = e->pos;
521 
522 	/* rlimits are optional */
523 	if (unpack_nameX(e, AA_STRUCT, "rlimits")) {
524 		int i, size;
525 		u32 tmp = 0;
526 		if (!unpack_u32(e, &tmp, NULL))
527 			goto fail;
528 		profile->rlimits.mask = tmp;
529 
530 		size = unpack_array(e, NULL);
531 		if (size > RLIM_NLIMITS)
532 			goto fail;
533 		for (i = 0; i < size; i++) {
534 			u64 tmp2 = 0;
535 			int a = aa_map_resource(i);
536 			if (!unpack_u64(e, &tmp2, NULL))
537 				goto fail;
538 			profile->rlimits.limits[a].rlim_max = tmp2;
539 		}
540 		if (!unpack_nameX(e, AA_ARRAYEND, NULL))
541 			goto fail;
542 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
543 			goto fail;
544 	}
545 	return 1;
546 
547 fail:
548 	e->pos = pos;
549 	return 0;
550 }
551 
552 static void *kvmemdup(const void *src, size_t len)
553 {
554 	void *p = kvmalloc(len, GFP_KERNEL);
555 
556 	if (p)
557 		memcpy(p, src, len);
558 	return p;
559 }
560 
561 static u32 strhash(const void *data, u32 len, u32 seed)
562 {
563 	const char * const *key = data;
564 
565 	return jhash(*key, strlen(*key), seed);
566 }
567 
568 static int datacmp(struct rhashtable_compare_arg *arg, const void *obj)
569 {
570 	const struct aa_data *data = obj;
571 	const char * const *key = arg->key;
572 
573 	return strcmp(data->key, *key);
574 }
575 
576 /**
577  * unpack_profile - unpack a serialized profile
578  * @e: serialized data extent information (NOT NULL)
579  *
580  * NOTE: unpack profile sets audit struct if there is a failure
581  */
582 static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
583 {
584 	struct aa_profile *profile = NULL;
585 	const char *tmpname, *tmpns = NULL, *name = NULL;
586 	const char *info = "failed to unpack profile";
587 	size_t ns_len;
588 	struct rhashtable_params params = { 0 };
589 	char *key = NULL;
590 	struct aa_data *data;
591 	int i, error = -EPROTO;
592 	kernel_cap_t tmpcap;
593 	u32 tmp;
594 
595 	*ns_name = NULL;
596 
597 	/* check that we have the right struct being passed */
598 	if (!unpack_nameX(e, AA_STRUCT, "profile"))
599 		goto fail;
600 	if (!unpack_str(e, &name, NULL))
601 		goto fail;
602 	if (*name == '\0')
603 		goto fail;
604 
605 	tmpname = aa_splitn_fqname(name, strlen(name), &tmpns, &ns_len);
606 	if (tmpns) {
607 		*ns_name = kstrndup(tmpns, ns_len, GFP_KERNEL);
608 		if (!*ns_name) {
609 			info = "out of memory";
610 			goto fail;
611 		}
612 		name = tmpname;
613 	}
614 
615 	profile = aa_alloc_profile(name, NULL, GFP_KERNEL);
616 	if (!profile)
617 		return ERR_PTR(-ENOMEM);
618 
619 	/* profile renaming is optional */
620 	(void) unpack_str(e, &profile->rename, "rename");
621 
622 	/* attachment string is optional */
623 	(void) unpack_str(e, &profile->attach, "attach");
624 
625 	/* xmatch is optional and may be NULL */
626 	profile->xmatch = unpack_dfa(e);
627 	if (IS_ERR(profile->xmatch)) {
628 		error = PTR_ERR(profile->xmatch);
629 		profile->xmatch = NULL;
630 		info = "bad xmatch";
631 		goto fail;
632 	}
633 	/* xmatch_len is not optional if xmatch is set */
634 	if (profile->xmatch) {
635 		if (!unpack_u32(e, &tmp, NULL)) {
636 			info = "missing xmatch len";
637 			goto fail;
638 		}
639 		profile->xmatch_len = tmp;
640 	}
641 
642 	/* disconnected attachment string is optional */
643 	(void) unpack_str(e, &profile->disconnected, "disconnected");
644 
645 	/* per profile debug flags (complain, audit) */
646 	if (!unpack_nameX(e, AA_STRUCT, "flags")) {
647 		info = "profile missing flags";
648 		goto fail;
649 	}
650 	info = "failed to unpack profile flags";
651 	if (!unpack_u32(e, &tmp, NULL))
652 		goto fail;
653 	if (tmp & PACKED_FLAG_HAT)
654 		profile->label.flags |= FLAG_HAT;
655 	if (!unpack_u32(e, &tmp, NULL))
656 		goto fail;
657 	if (tmp == PACKED_MODE_COMPLAIN || (e->version & FORCE_COMPLAIN_FLAG))
658 		profile->mode = APPARMOR_COMPLAIN;
659 	else if (tmp == PACKED_MODE_KILL)
660 		profile->mode = APPARMOR_KILL;
661 	else if (tmp == PACKED_MODE_UNCONFINED)
662 		profile->mode = APPARMOR_UNCONFINED;
663 	if (!unpack_u32(e, &tmp, NULL))
664 		goto fail;
665 	if (tmp)
666 		profile->audit = AUDIT_ALL;
667 
668 	if (!unpack_nameX(e, AA_STRUCTEND, NULL))
669 		goto fail;
670 
671 	/* path_flags is optional */
672 	if (unpack_u32(e, &profile->path_flags, "path_flags"))
673 		profile->path_flags |= profile->label.flags &
674 			PATH_MEDIATE_DELETED;
675 	else
676 		/* set a default value if path_flags field is not present */
677 		profile->path_flags = PATH_MEDIATE_DELETED;
678 
679 	info = "failed to unpack profile capabilities";
680 	if (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL))
681 		goto fail;
682 	if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL))
683 		goto fail;
684 	if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL))
685 		goto fail;
686 	if (!unpack_u32(e, &tmpcap.cap[0], NULL))
687 		goto fail;
688 
689 	info = "failed to unpack upper profile capabilities";
690 	if (unpack_nameX(e, AA_STRUCT, "caps64")) {
691 		/* optional upper half of 64 bit caps */
692 		if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL))
693 			goto fail;
694 		if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL))
695 			goto fail;
696 		if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL))
697 			goto fail;
698 		if (!unpack_u32(e, &(tmpcap.cap[1]), NULL))
699 			goto fail;
700 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
701 			goto fail;
702 	}
703 
704 	info = "failed to unpack extended profile capabilities";
705 	if (unpack_nameX(e, AA_STRUCT, "capsx")) {
706 		/* optional extended caps mediation mask */
707 		if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL))
708 			goto fail;
709 		if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL))
710 			goto fail;
711 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
712 			goto fail;
713 	}
714 
715 	if (!unpack_rlimits(e, profile)) {
716 		info = "failed to unpack profile rlimits";
717 		goto fail;
718 	}
719 
720 	if (unpack_nameX(e, AA_STRUCT, "policydb")) {
721 		/* generic policy dfa - optional and may be NULL */
722 		info = "failed to unpack policydb";
723 		profile->policy.dfa = unpack_dfa(e);
724 		if (IS_ERR(profile->policy.dfa)) {
725 			error = PTR_ERR(profile->policy.dfa);
726 			profile->policy.dfa = NULL;
727 			goto fail;
728 		} else if (!profile->policy.dfa) {
729 			error = -EPROTO;
730 			goto fail;
731 		}
732 		if (!unpack_u32(e, &profile->policy.start[0], "start"))
733 			/* default start state */
734 			profile->policy.start[0] = DFA_START;
735 		/* setup class index */
736 		for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) {
737 			profile->policy.start[i] =
738 				aa_dfa_next(profile->policy.dfa,
739 					    profile->policy.start[0],
740 					    i);
741 		}
742 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
743 			goto fail;
744 	} else
745 		profile->policy.dfa = aa_get_dfa(nulldfa);
746 
747 	/* get file rules */
748 	profile->file.dfa = unpack_dfa(e);
749 	if (IS_ERR(profile->file.dfa)) {
750 		error = PTR_ERR(profile->file.dfa);
751 		profile->file.dfa = NULL;
752 		info = "failed to unpack profile file rules";
753 		goto fail;
754 	} else if (profile->file.dfa) {
755 		if (!unpack_u32(e, &profile->file.start, "dfa_start"))
756 			/* default start state */
757 			profile->file.start = DFA_START;
758 	} else if (profile->policy.dfa &&
759 		   profile->policy.start[AA_CLASS_FILE]) {
760 		profile->file.dfa = aa_get_dfa(profile->policy.dfa);
761 		profile->file.start = profile->policy.start[AA_CLASS_FILE];
762 	} else
763 		profile->file.dfa = aa_get_dfa(nulldfa);
764 
765 	if (!unpack_trans_table(e, profile)) {
766 		info = "failed to unpack profile transition table";
767 		goto fail;
768 	}
769 
770 	if (unpack_nameX(e, AA_STRUCT, "data")) {
771 		info = "out of memory";
772 		profile->data = kzalloc(sizeof(*profile->data), GFP_KERNEL);
773 		if (!profile->data)
774 			goto fail;
775 
776 		params.nelem_hint = 3;
777 		params.key_len = sizeof(void *);
778 		params.key_offset = offsetof(struct aa_data, key);
779 		params.head_offset = offsetof(struct aa_data, head);
780 		params.hashfn = strhash;
781 		params.obj_cmpfn = datacmp;
782 
783 		if (rhashtable_init(profile->data, &params)) {
784 			info = "failed to init key, value hash table";
785 			goto fail;
786 		}
787 
788 		while (unpack_strdup(e, &key, NULL)) {
789 			data = kzalloc(sizeof(*data), GFP_KERNEL);
790 			if (!data) {
791 				kzfree(key);
792 				goto fail;
793 			}
794 
795 			data->key = key;
796 			data->size = unpack_blob(e, &data->data, NULL);
797 			data->data = kvmemdup(data->data, data->size);
798 			if (data->size && !data->data) {
799 				kzfree(data->key);
800 				kzfree(data);
801 				goto fail;
802 			}
803 
804 			rhashtable_insert_fast(profile->data, &data->head,
805 					       profile->data->p);
806 		}
807 
808 		if (!unpack_nameX(e, AA_STRUCTEND, NULL)) {
809 			info = "failed to unpack end of key, value data table";
810 			goto fail;
811 		}
812 	}
813 
814 	if (!unpack_nameX(e, AA_STRUCTEND, NULL)) {
815 		info = "failed to unpack end of profile";
816 		goto fail;
817 	}
818 
819 	return profile;
820 
821 fail:
822 	if (profile)
823 		name = NULL;
824 	else if (!name)
825 		name = "unknown";
826 	audit_iface(profile, NULL, name, info, e, error);
827 	aa_free_profile(profile);
828 
829 	return ERR_PTR(error);
830 }
831 
832 /**
833  * verify_head - unpack serialized stream header
834  * @e: serialized data read head (NOT NULL)
835  * @required: whether the header is required or optional
836  * @ns: Returns - namespace if one is specified else NULL (NOT NULL)
837  *
838  * Returns: error or 0 if header is good
839  */
840 static int verify_header(struct aa_ext *e, int required, const char **ns)
841 {
842 	int error = -EPROTONOSUPPORT;
843 	const char *name = NULL;
844 	*ns = NULL;
845 
846 	/* get the interface version */
847 	if (!unpack_u32(e, &e->version, "version")) {
848 		if (required) {
849 			audit_iface(NULL, NULL, NULL, "invalid profile format",
850 				    e, error);
851 			return error;
852 		}
853 	}
854 
855 	/* Check that the interface version is currently supported.
856 	 * if not specified use previous version
857 	 * Mask off everything that is not kernel abi version
858 	 */
859 	if (VERSION_LT(e->version, v5) || VERSION_GT(e->version, v7)) {
860 		audit_iface(NULL, NULL, NULL, "unsupported interface version",
861 			    e, error);
862 		return error;
863 	}
864 
865 	/* read the namespace if present */
866 	if (unpack_str(e, &name, "namespace")) {
867 		if (*name == '\0') {
868 			audit_iface(NULL, NULL, NULL, "invalid namespace name",
869 				    e, error);
870 			return error;
871 		}
872 		if (*ns && strcmp(*ns, name))
873 			audit_iface(NULL, NULL, NULL, "invalid ns change", e,
874 				    error);
875 		else if (!*ns)
876 			*ns = name;
877 	}
878 
879 	return 0;
880 }
881 
882 static bool verify_xindex(int xindex, int table_size)
883 {
884 	int index, xtype;
885 	xtype = xindex & AA_X_TYPE_MASK;
886 	index = xindex & AA_X_INDEX_MASK;
887 	if (xtype == AA_X_TABLE && index >= table_size)
888 		return 0;
889 	return 1;
890 }
891 
892 /* verify dfa xindexes are in range of transition tables */
893 static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size)
894 {
895 	int i;
896 	for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
897 		if (!verify_xindex(dfa_user_xindex(dfa, i), table_size))
898 			return 0;
899 		if (!verify_xindex(dfa_other_xindex(dfa, i), table_size))
900 			return 0;
901 	}
902 	return 1;
903 }
904 
905 /**
906  * verify_profile - Do post unpack analysis to verify profile consistency
907  * @profile: profile to verify (NOT NULL)
908  *
909  * Returns: 0 if passes verification else error
910  */
911 static int verify_profile(struct aa_profile *profile)
912 {
913 	if (profile->file.dfa &&
914 	    !verify_dfa_xindex(profile->file.dfa,
915 			       profile->file.trans.size)) {
916 		audit_iface(profile, NULL, NULL, "Invalid named transition",
917 			    NULL, -EPROTO);
918 		return -EPROTO;
919 	}
920 
921 	return 0;
922 }
923 
924 void aa_load_ent_free(struct aa_load_ent *ent)
925 {
926 	if (ent) {
927 		aa_put_profile(ent->rename);
928 		aa_put_profile(ent->old);
929 		aa_put_profile(ent->new);
930 		kfree(ent->ns_name);
931 		kzfree(ent);
932 	}
933 }
934 
935 struct aa_load_ent *aa_load_ent_alloc(void)
936 {
937 	struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL);
938 	if (ent)
939 		INIT_LIST_HEAD(&ent->list);
940 	return ent;
941 }
942 
943 /**
944  * aa_unpack - unpack packed binary profile(s) data loaded from user space
945  * @udata: user data copied to kmem  (NOT NULL)
946  * @lh: list to place unpacked profiles in a aa_repl_ws
947  * @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
948  *
949  * Unpack user data and return refcounted allocated profile(s) stored in
950  * @lh in order of discovery, with the list chain stored in base.list
951  * or error
952  *
953  * Returns: profile(s) on @lh else error pointer if fails to unpack
954  */
955 int aa_unpack(struct aa_loaddata *udata, struct list_head *lh,
956 	      const char **ns)
957 {
958 	struct aa_load_ent *tmp, *ent;
959 	struct aa_profile *profile = NULL;
960 	int error;
961 	struct aa_ext e = {
962 		.start = udata->data,
963 		.end = udata->data + udata->size,
964 		.pos = udata->data,
965 	};
966 
967 	*ns = NULL;
968 	while (e.pos < e.end) {
969 		char *ns_name = NULL;
970 		void *start;
971 		error = verify_header(&e, e.pos == e.start, ns);
972 		if (error)
973 			goto fail;
974 
975 		start = e.pos;
976 		profile = unpack_profile(&e, &ns_name);
977 		if (IS_ERR(profile)) {
978 			error = PTR_ERR(profile);
979 			goto fail;
980 		}
981 
982 		error = verify_profile(profile);
983 		if (error)
984 			goto fail_profile;
985 
986 		if (aa_g_hash_policy)
987 			error = aa_calc_profile_hash(profile, e.version, start,
988 						     e.pos - start);
989 		if (error)
990 			goto fail_profile;
991 
992 		ent = aa_load_ent_alloc();
993 		if (!ent) {
994 			error = -ENOMEM;
995 			goto fail_profile;
996 		}
997 
998 		ent->new = profile;
999 		ent->ns_name = ns_name;
1000 		list_add_tail(&ent->list, lh);
1001 	}
1002 	udata->abi = e.version & K_ABI_MASK;
1003 	if (aa_g_hash_policy) {
1004 		udata->hash = aa_calc_hash(udata->data, udata->size);
1005 		if (IS_ERR(udata->hash)) {
1006 			error = PTR_ERR(udata->hash);
1007 			udata->hash = NULL;
1008 			goto fail;
1009 		}
1010 	}
1011 	return 0;
1012 
1013 fail_profile:
1014 	aa_put_profile(profile);
1015 
1016 fail:
1017 	list_for_each_entry_safe(ent, tmp, lh, list) {
1018 		list_del_init(&ent->list);
1019 		aa_load_ent_free(ent);
1020 	}
1021 
1022 	return error;
1023 }
1024