xref: /linux/security/apparmor/policy_unpack.c (revision 8fefe68784ae1606e11a5c65c04167c3b95051a0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AppArmor security module
4  *
5  * This file contains AppArmor functions for unpacking policy loaded from
6  * userspace.
7  *
8  * Copyright (C) 1998-2008 Novell/SUSE
9  * Copyright 2009-2010 Canonical Ltd.
10  *
11  * AppArmor uses a serialized binary format for loading policy. To find
12  * policy format documentation see Documentation/admin-guide/LSM/apparmor.rst
13  * All policy is validated before it is used.
14  */
15 
16 #include <linux/unaligned.h>
17 #include <kunit/visibility.h>
18 #include <linux/ctype.h>
19 #include <linux/errno.h>
20 #include <linux/zstd.h>
21 
22 #include "include/apparmor.h"
23 #include "include/audit.h"
24 #include "include/cred.h"
25 #include "include/crypto.h"
26 #include "include/file.h"
27 #include "include/match.h"
28 #include "include/net.h"
29 #include "include/path.h"
30 #include "include/policy.h"
31 #include "include/policy_unpack.h"
32 #include "include/policy_compat.h"
33 #include "include/signal.h"
34 
35 /* audit callback for unpack fields */
audit_cb(struct audit_buffer * ab,void * va)36 static void audit_cb(struct audit_buffer *ab, void *va)
37 {
38 	struct common_audit_data *sa = va;
39 	struct apparmor_audit_data *ad = aad(sa);
40 
41 	if (ad->iface.ns) {
42 		audit_log_format(ab, " ns=");
43 		audit_log_untrustedstring(ab, ad->iface.ns);
44 	}
45 	if (ad->name) {
46 		audit_log_format(ab, " name=");
47 		audit_log_untrustedstring(ab, ad->name);
48 	}
49 	if (ad->iface.pos)
50 		audit_log_format(ab, " offset=%ld", ad->iface.pos);
51 }
52 
53 /**
54  * audit_iface - do audit message for policy unpacking/load/replace/remove
55  * @new: profile if it has been allocated (MAYBE NULL)
56  * @ns_name: name of the ns the profile is to be loaded to (MAY BE NULL)
57  * @name: name of the profile being manipulated (MAYBE NULL)
58  * @info: any extra info about the failure (MAYBE NULL)
59  * @e: buffer position info
60  * @error: error code
61  *
62  * Returns: %0 or error
63  */
audit_iface(struct aa_profile * new,const char * ns_name,const char * name,const char * info,struct aa_ext * e,int error)64 static int audit_iface(struct aa_profile *new, const char *ns_name,
65 		       const char *name, const char *info, struct aa_ext *e,
66 		       int error)
67 {
68 	struct aa_profile *profile = labels_profile(aa_current_raw_label());
69 	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_NONE, NULL);
70 	if (e)
71 		ad.iface.pos = e->pos - e->start;
72 	ad.iface.ns = ns_name;
73 	if (new)
74 		ad.name = new->base.hname;
75 	else
76 		ad.name = name;
77 	ad.info = info;
78 	ad.error = error;
79 
80 	return aa_audit(AUDIT_APPARMOR_STATUS, profile, &ad, audit_cb);
81 }
82 
__aa_loaddata_update(struct aa_loaddata * data,long revision)83 void __aa_loaddata_update(struct aa_loaddata *data, long revision)
84 {
85 	AA_BUG(!data);
86 	AA_BUG(!data->ns);
87 	AA_BUG(!mutex_is_locked(&data->ns->lock));
88 	AA_BUG(data->revision > revision);
89 
90 	data->revision = revision;
91 	if ((data->dents[AAFS_LOADDATA_REVISION])) {
92 		struct inode *inode;
93 
94 		inode = d_inode(data->dents[AAFS_LOADDATA_DIR]);
95 		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
96 
97 		inode = d_inode(data->dents[AAFS_LOADDATA_REVISION]);
98 		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
99 	}
100 }
101 
aa_rawdata_eq(struct aa_loaddata * l,struct aa_loaddata * r)102 bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r)
103 {
104 	if (l->size != r->size)
105 		return false;
106 	if (l->compressed_size != r->compressed_size)
107 		return false;
108 	if (aa_g_hash_policy && memcmp(l->hash, r->hash, aa_hash_size()) != 0)
109 		return false;
110 	return memcmp(l->data, r->data, r->compressed_size ?: r->size) == 0;
111 }
112 
do_loaddata_free(struct aa_loaddata * d)113 static void do_loaddata_free(struct aa_loaddata *d)
114 {
115 	kfree_sensitive(d->hash);
116 	kfree_sensitive(d->name);
117 	kvfree(d->data);
118 	kfree_sensitive(d);
119 }
120 
aa_loaddata_kref(struct kref * kref)121 void aa_loaddata_kref(struct kref *kref)
122 {
123 	struct aa_loaddata *d = container_of(kref, struct aa_loaddata,
124 					     count.count);
125 
126 	do_loaddata_free(d);
127 }
128 
129 /*
130  * need to take the ns mutex lock which is NOT safe most places that
131  * put_loaddata is called, so we have to delay freeing it
132  */
do_ploaddata_rmfs(struct work_struct * work)133 static void do_ploaddata_rmfs(struct work_struct *work)
134 {
135 	struct aa_loaddata *d = container_of(work, struct aa_loaddata, work);
136 	struct aa_ns *ns = aa_get_ns(d->ns);
137 
138 	if (ns) {
139 		mutex_lock_nested(&ns->lock, ns->level);
140 		/* remove fs ref to loaddata */
141 		__aa_fs_remove_rawdata(d);
142 		mutex_unlock(&ns->lock);
143 		aa_put_ns(ns);
144 	}
145 	/* called by dropping last pcount, so drop its associated icount */
146 	aa_put_i_loaddata(d);
147 }
148 
aa_ploaddata_kref(struct kref * kref)149 void aa_ploaddata_kref(struct kref *kref)
150 {
151 	struct aa_loaddata *d = container_of(kref, struct aa_loaddata, pcount);
152 
153 	if (d) {
154 		INIT_WORK(&d->work, do_ploaddata_rmfs);
155 		schedule_work(&d->work);
156 	}
157 }
158 
aa_loaddata_alloc(size_t size)159 struct aa_loaddata *aa_loaddata_alloc(size_t size)
160 {
161 	struct aa_loaddata *d;
162 
163 	d = kzalloc_obj(*d);
164 	if (d == NULL)
165 		return ERR_PTR(-ENOMEM);
166 	d->data = kvzalloc(size, GFP_KERNEL);
167 	if (!d->data) {
168 		kfree(d);
169 		return ERR_PTR(-ENOMEM);
170 	}
171 	kref_init(&d->count.count);
172 	d->count.reftype = REF_RAWDATA;
173 	kref_init(&d->pcount);
174 	INIT_LIST_HEAD(&d->list);
175 
176 	return d;
177 }
178 
179 /* test if read will be in packed data bounds */
aa_inbounds(struct aa_ext * e,size_t size)180 VISIBLE_IF_KUNIT bool aa_inbounds(struct aa_ext *e, size_t size)
181 {
182 	return (size <= e->end - e->pos);
183 }
184 EXPORT_SYMBOL_IF_KUNIT(aa_inbounds);
185 
186 /**
187  * aa_unpack_u16_chunk - test and do bounds checking for a u16 size based chunk
188  * @e: serialized data read head (NOT NULL)
189  * @chunk: start address for chunk of data (NOT NULL)
190  *
191  * Returns: the size of chunk found with the read head at the end of the chunk.
192  */
aa_unpack_u16_chunk(struct aa_ext * e,char ** chunk)193 VISIBLE_IF_KUNIT size_t aa_unpack_u16_chunk(struct aa_ext *e, char **chunk)
194 {
195 	size_t size = 0;
196 	void *pos = e->pos;
197 
198 	if (!aa_inbounds(e, sizeof(u16)))
199 		goto fail;
200 	size = le16_to_cpu(get_unaligned((__le16 *) e->pos));
201 	e->pos += sizeof(__le16);
202 	if (!aa_inbounds(e, size))
203 		goto fail;
204 	*chunk = e->pos;
205 	e->pos += size;
206 	return size;
207 
208 fail:
209 	e->pos = pos;
210 	return 0;
211 }
212 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u16_chunk);
213 
214 /* unpack control byte */
aa_unpack_X(struct aa_ext * e,enum aa_code code)215 VISIBLE_IF_KUNIT bool aa_unpack_X(struct aa_ext *e, enum aa_code code)
216 {
217 	if (!aa_inbounds(e, 1))
218 		return false;
219 	if (*(u8 *) e->pos != code)
220 		return false;
221 	e->pos++;
222 	return true;
223 }
224 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_X);
225 
226 /**
227  * aa_unpack_nameX - check is the next element is of type X with a name of @name
228  * @e: serialized data extent information  (NOT NULL)
229  * @code: type code
230  * @name: name to match to the serialized element.  (MAYBE NULL)
231  *
232  * check that the next serialized data element is of type X and has a tag
233  * name @name.  If @name is specified then there must be a matching
234  * name element in the stream.  If @name is NULL any name element will be
235  * skipped and only the typecode will be tested.
236  *
237  * Returns true on success (both type code and name tests match) and the read
238  * head is advanced past the headers
239  *
240  * Returns: false if either match fails, the read head does not move
241  */
aa_unpack_nameX(struct aa_ext * e,enum aa_code code,const char * name)242 VISIBLE_IF_KUNIT bool aa_unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
243 {
244 	/*
245 	 * May need to reset pos if name or type doesn't match
246 	 */
247 	void *pos = e->pos;
248 	/*
249 	 * Check for presence of a tagname, and if present name size
250 	 * AA_NAME tag value is a u16.
251 	 */
252 	if (aa_unpack_X(e, AA_NAME)) {
253 		char *tag = NULL;
254 		size_t size = aa_unpack_u16_chunk(e, &tag);
255 		/* if a name is specified it must match. otherwise skip tag */
256 		if (name && (!size || tag[size-1] != '\0' || strcmp(name, tag)))
257 			goto fail;
258 	} else if (name) {
259 		/* if a name is specified and there is no name tag fail */
260 		goto fail;
261 	}
262 
263 	/* now check if type code matches */
264 	if (aa_unpack_X(e, code))
265 		return true;
266 
267 fail:
268 	e->pos = pos;
269 	return false;
270 }
271 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_nameX);
272 
unpack_u8(struct aa_ext * e,u8 * data,const char * name)273 static bool unpack_u8(struct aa_ext *e, u8 *data, const char *name)
274 {
275 	void *pos = e->pos;
276 
277 	if (aa_unpack_nameX(e, AA_U8, name)) {
278 		if (!aa_inbounds(e, sizeof(u8)))
279 			goto fail;
280 		if (data)
281 			*data = *((u8 *)e->pos);
282 		e->pos += sizeof(u8);
283 		return true;
284 	}
285 
286 fail:
287 	e->pos = pos;
288 	return false;
289 }
290 
aa_unpack_u32(struct aa_ext * e,u32 * data,const char * name)291 VISIBLE_IF_KUNIT bool aa_unpack_u32(struct aa_ext *e, u32 *data, const char *name)
292 {
293 	void *pos = e->pos;
294 
295 	if (aa_unpack_nameX(e, AA_U32, name)) {
296 		if (!aa_inbounds(e, sizeof(u32)))
297 			goto fail;
298 		if (data)
299 			*data = le32_to_cpu(get_unaligned((__le32 *) e->pos));
300 		e->pos += sizeof(u32);
301 		return true;
302 	}
303 
304 fail:
305 	e->pos = pos;
306 	return false;
307 }
308 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u32);
309 
aa_unpack_u64(struct aa_ext * e,u64 * data,const char * name)310 VISIBLE_IF_KUNIT bool aa_unpack_u64(struct aa_ext *e, u64 *data, const char *name)
311 {
312 	void *pos = e->pos;
313 
314 	if (aa_unpack_nameX(e, AA_U64, name)) {
315 		if (!aa_inbounds(e, sizeof(u64)))
316 			goto fail;
317 		if (data)
318 			*data = le64_to_cpu(get_unaligned((__le64 *) e->pos));
319 		e->pos += sizeof(u64);
320 		return true;
321 	}
322 
323 fail:
324 	e->pos = pos;
325 	return false;
326 }
327 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u64);
328 
aa_unpack_cap_low(struct aa_ext * e,kernel_cap_t * data,const char * name)329 static bool aa_unpack_cap_low(struct aa_ext *e, kernel_cap_t *data, const char *name)
330 {
331 	u32 val;
332 
333 	if (!aa_unpack_u32(e, &val, name))
334 		return false;
335 	data->val = val;
336 	return true;
337 }
338 
aa_unpack_cap_high(struct aa_ext * e,kernel_cap_t * data,const char * name)339 static bool aa_unpack_cap_high(struct aa_ext *e, kernel_cap_t *data, const char *name)
340 {
341 	u32 val;
342 
343 	if (!aa_unpack_u32(e, &val, name))
344 		return false;
345 	data->val = (u32)data->val | ((u64)val << 32);
346 	return true;
347 }
348 
aa_unpack_array(struct aa_ext * e,const char * name,u16 * size)349 VISIBLE_IF_KUNIT bool aa_unpack_array(struct aa_ext *e, const char *name, u16 *size)
350 {
351 	void *pos = e->pos;
352 
353 	if (aa_unpack_nameX(e, AA_ARRAY, name)) {
354 		if (!aa_inbounds(e, sizeof(u16)))
355 			goto fail;
356 		*size = le16_to_cpu(get_unaligned((__le16 *) e->pos));
357 		e->pos += sizeof(u16);
358 		return true;
359 	}
360 
361 fail:
362 	e->pos = pos;
363 	return false;
364 }
365 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_array);
366 
aa_unpack_blob(struct aa_ext * e,char ** blob,const char * name)367 VISIBLE_IF_KUNIT size_t aa_unpack_blob(struct aa_ext *e, char **blob, const char *name)
368 {
369 	void *pos = e->pos;
370 
371 	if (aa_unpack_nameX(e, AA_BLOB, name)) {
372 		u32 size;
373 		if (!aa_inbounds(e, sizeof(u32)))
374 			goto fail;
375 		size = le32_to_cpu(get_unaligned((__le32 *) e->pos));
376 		e->pos += sizeof(u32);
377 		if (aa_inbounds(e, (size_t) size)) {
378 			*blob = e->pos;
379 			e->pos += size;
380 			return size;
381 		}
382 	}
383 
384 fail:
385 	e->pos = pos;
386 	return 0;
387 }
388 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_blob);
389 
aa_unpack_str(struct aa_ext * e,const char ** string,const char * name)390 VISIBLE_IF_KUNIT int aa_unpack_str(struct aa_ext *e, const char **string, const char *name)
391 {
392 	char *src_str;
393 	size_t size = 0;
394 	void *pos = e->pos;
395 	*string = NULL;
396 	if (aa_unpack_nameX(e, AA_STRING, name)) {
397 		size = aa_unpack_u16_chunk(e, &src_str);
398 		if (size) {
399 			/* strings are null terminated, length is size - 1 */
400 			if (src_str[size - 1] != 0)
401 				goto fail;
402 			*string = src_str;
403 
404 			return size;
405 		}
406 	}
407 
408 fail:
409 	e->pos = pos;
410 	return 0;
411 }
412 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_str);
413 
aa_unpack_strdup(struct aa_ext * e,char ** string,const char * name)414 VISIBLE_IF_KUNIT int aa_unpack_strdup(struct aa_ext *e, char **string, const char *name)
415 {
416 	const char *tmp;
417 	void *pos = e->pos;
418 	int res = aa_unpack_str(e, &tmp, name);
419 	*string = NULL;
420 
421 	if (!res)
422 		return 0;
423 
424 	*string = kmemdup(tmp, res, GFP_KERNEL);
425 	if (!*string) {
426 		e->pos = pos;
427 		return 0;
428 	}
429 
430 	return res;
431 }
432 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_strdup);
433 
434 
435 /**
436  * unpack_dfa - unpack a file rule dfa
437  * @e: serialized data extent information (NOT NULL)
438  * @flags: dfa flags to check
439  *
440  * returns dfa or ERR_PTR or NULL if no dfa
441  */
unpack_dfa(struct aa_ext * e,int flags)442 static struct aa_dfa *unpack_dfa(struct aa_ext *e, int flags)
443 {
444 	char *blob = NULL;
445 	size_t size;
446 	struct aa_dfa *dfa = NULL;
447 
448 	size = aa_unpack_blob(e, &blob, "aadfa");
449 	if (size) {
450 		/*
451 		 * The dfa is aligned with in the blob to 8 bytes
452 		 * from the beginning of the stream.
453 		 * alignment adjust needed by dfa unpack
454 		 */
455 		size_t sz = blob - (char *) e->start -
456 			((e->pos - e->start) & 7);
457 		size_t pad = ALIGN(sz, 8) - sz;
458 		if (aa_g_paranoid_load)
459 			flags |= DFA_FLAG_VERIFY_STATES;
460 		dfa = aa_dfa_unpack(blob + pad, size - pad, flags);
461 
462 		if (IS_ERR(dfa))
463 			return dfa;
464 
465 	}
466 
467 	return dfa;
468 }
469 
process_strs_entry(char * str,int size,bool multi)470 static int process_strs_entry(char *str, int size, bool multi)
471 {
472 	int c = 1;
473 
474 	if (size <= 0)
475 		return -1;
476 	if (multi) {
477 		if (size < 2)
478 			return -2;
479 		/* multi ends with double \0 */
480 		if (str[size - 2])
481 			return -3;
482 	}
483 
484 	char *save = str;
485 	char *pos = str;
486 	char *end = multi ? str + size - 2 : str + size - 1;
487 	/* count # of internal \0 */
488 	while (str < end) {
489 		if (str == pos) {
490 			/* starts with ... */
491 			if (!*str) {
492 				AA_DEBUG(DEBUG_UNPACK,
493 					 "starting with null save=%lu size %d c=%d",
494 					 (unsigned long)(str - save), size, c);
495 				return -4;
496 			}
497 			if (isspace(*str))
498 				return -5;
499 			if (*str == ':') {
500 				/* :ns_str\0str\0
501 				 * first character after : must be valid
502 				 */
503 				if (!str[1])
504 					return -6;
505 			}
506 		} else if (!*str) {
507 			if (*pos == ':')
508 				*str = ':';
509 			else
510 				c++;
511 			pos = str +  1;
512 		}
513 		str++;
514 	} /* while */
515 
516 	return c;
517 }
518 
519 /**
520  * unpack_strs_table - unpack a profile transition table
521  * @e: serialized data extent information  (NOT NULL)
522  * @name: name of table (MAY BE NULL)
523  * @multi: allow multiple strings on a single entry
524  * @strs: str table to unpack to (NOT NULL)
525  *
526  * Returns: 0 if table successfully unpacked or not present, else error
527  */
unpack_strs_table(struct aa_ext * e,const char * name,bool multi,struct aa_str_table * strs)528 static int unpack_strs_table(struct aa_ext *e, const char *name, bool multi,
529 			      struct aa_str_table *strs)
530 {
531 	void *saved_pos = e->pos;
532 	struct aa_str_table_ent *table = NULL;
533 	int error = -EPROTO;
534 
535 	/* exec table is optional */
536 	if (aa_unpack_nameX(e, AA_STRUCT, name)) {
537 		u16 size;
538 		int i;
539 
540 		if (!aa_unpack_array(e, NULL, &size))
541 			/*
542 			 * Note: index into trans table array is a max
543 			 * of 2^24, but unpack array can only unpack
544 			 * an array of 2^16 in size atm so no need
545 			 * for size check here
546 			 */
547 			goto fail;
548 		table = kzalloc_objs(struct aa_str_table_ent, size);
549 		if (!table) {
550 			error = -ENOMEM;
551 			goto fail;
552 		}
553 		strs->table = table;
554 		strs->size = size;
555 		for (i = 0; i < size; i++) {
556 			char *str;
557 			int c, size2 = aa_unpack_strdup(e, &str, NULL);
558 			/* aa_unpack_strdup verifies that the last character is
559 			 * null termination byte.
560 			 */
561 			c = process_strs_entry(str, size2, multi);
562 			if (c <= 0) {
563 				AA_DEBUG(DEBUG_UNPACK, "process_strs %d i %d pos %ld",
564 					 c, i,
565 					 (unsigned long)(e->pos - saved_pos));
566 				goto fail;
567 			}
568 			if (!multi && c > 1) {
569 				AA_DEBUG(DEBUG_UNPACK, "!multi && c > 1");
570 				/* fail - all other cases with embedded \0 */
571 				goto fail;
572 			}
573 			table[i].strs = str;
574 			table[i].count = c;
575 			table[i].size = size2;
576 		}
577 		if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
578 			goto fail;
579 		if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
580 			goto fail;
581 	}
582 	return 0;
583 
584 fail:
585 	aa_destroy_str_table(strs);
586 	e->pos = saved_pos;
587 	return error;
588 }
589 
unpack_xattrs(struct aa_ext * e,struct aa_profile * profile)590 static bool unpack_xattrs(struct aa_ext *e, struct aa_profile *profile)
591 {
592 	void *pos = e->pos;
593 
594 	if (aa_unpack_nameX(e, AA_STRUCT, "xattrs")) {
595 		u16 size;
596 		int i;
597 
598 		if (!aa_unpack_array(e, NULL, &size))
599 			goto fail;
600 		profile->attach.xattr_count = size;
601 		profile->attach.xattrs = kcalloc(size, sizeof(char *), GFP_KERNEL);
602 		if (!profile->attach.xattrs)
603 			goto fail;
604 		for (i = 0; i < size; i++) {
605 			if (!aa_unpack_strdup(e, &profile->attach.xattrs[i], NULL))
606 				goto fail;
607 		}
608 		if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
609 			goto fail;
610 		if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
611 			goto fail;
612 	}
613 
614 	return true;
615 
616 fail:
617 	e->pos = pos;
618 	return false;
619 }
620 
unpack_secmark(struct aa_ext * e,struct aa_ruleset * rules)621 static bool unpack_secmark(struct aa_ext *e, struct aa_ruleset *rules)
622 {
623 	void *pos = e->pos;
624 	u16 size;
625 	int i;
626 
627 	if (aa_unpack_nameX(e, AA_STRUCT, "secmark")) {
628 		if (!aa_unpack_array(e, NULL, &size))
629 			goto fail;
630 
631 		rules->secmark = kzalloc_objs(struct aa_secmark, size);
632 		if (!rules->secmark)
633 			goto fail;
634 
635 		rules->secmark_count = size;
636 
637 		for (i = 0; i < size; i++) {
638 			if (!unpack_u8(e, &rules->secmark[i].audit, NULL))
639 				goto fail;
640 			if (!unpack_u8(e, &rules->secmark[i].deny, NULL))
641 				goto fail;
642 			if (!aa_unpack_strdup(e, &rules->secmark[i].label, NULL))
643 				goto fail;
644 		}
645 		if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
646 			goto fail;
647 		if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
648 			goto fail;
649 	}
650 
651 	return true;
652 
653 fail:
654 	if (rules->secmark) {
655 		for (i = 0; i < size; i++)
656 			kfree_sensitive(rules->secmark[i].label);
657 		kfree_sensitive(rules->secmark);
658 		rules->secmark_count = 0;
659 		rules->secmark = NULL;
660 	}
661 
662 	e->pos = pos;
663 	return false;
664 }
665 
unpack_rlimits(struct aa_ext * e,struct aa_ruleset * rules)666 static bool unpack_rlimits(struct aa_ext *e, struct aa_ruleset *rules)
667 {
668 	void *pos = e->pos;
669 
670 	/* rlimits are optional */
671 	if (aa_unpack_nameX(e, AA_STRUCT, "rlimits")) {
672 		u16 size;
673 		int i;
674 		u32 tmp = 0;
675 		if (!aa_unpack_u32(e, &tmp, NULL))
676 			goto fail;
677 		rules->rlimits.mask = tmp;
678 
679 		if (!aa_unpack_array(e, NULL, &size) ||
680 		    size > RLIM_NLIMITS)
681 			goto fail;
682 		for (i = 0; i < size; i++) {
683 			u64 tmp2 = 0;
684 			int a = aa_map_resource(i);
685 			if (!aa_unpack_u64(e, &tmp2, NULL))
686 				goto fail;
687 			rules->rlimits.limits[a].rlim_max = tmp2;
688 		}
689 		if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
690 			goto fail;
691 		if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
692 			goto fail;
693 	}
694 	return true;
695 
696 fail:
697 	e->pos = pos;
698 	return false;
699 }
700 
701 
verify_tags(struct aa_tags_struct * tags,const char ** info)702 static bool verify_tags(struct aa_tags_struct *tags, const char **info)
703 {
704 	if ((tags->hdrs.size && !tags->hdrs.table) ||
705 	    (!tags->hdrs.size && tags->hdrs.table)) {
706 		*info = "failed verification tag.hdrs disagree";
707 		return false;
708 	}
709 	if ((tags->sets.size && !tags->sets.table) ||
710 	    (!tags->sets.size && tags->sets.table)) {
711 		*info = "failed verification tag.sets disagree";
712 		return false;
713 	}
714 	if ((tags->strs.size && !tags->strs.table) ||
715 	    (!tags->strs.size && tags->strs.table)) {
716 		*info = "failed verification tags->strs disagree";
717 		return false;
718 	}
719 	/* no data present */
720 	if (!tags->sets.size && !tags->hdrs.size && !tags->strs.size) {
721 		return true;
722 	} else if (!(tags->sets.size && tags->hdrs.size && tags->strs.size)) {
723 		/* some data present but not all */
724 		*info = "failed verification tags partial data present";
725 		return false;
726 	}
727 
728 	u32 i;
729 
730 	for (i = 0; i < tags->sets.size; i++) {
731 		/* count followed by count indexes into hdrs */
732 		u32 cnt = tags->sets.table[i];
733 
734 		if ((u64)i + cnt >= tags->sets.size) {
735 			AA_DEBUG(DEBUG_UNPACK,
736 				 "tagset too large %d+%d > sets.table[%d]",
737 				 i, cnt, tags->sets.size);
738 			*info = "failed verification tagset too large";
739 			return false;
740 		}
741 		for (; cnt; cnt--) {
742 			if (tags->sets.table[++i] >= tags->hdrs.size) {
743 				AA_DEBUG(DEBUG_UNPACK,
744 					 "tagsets idx out of bounds cnt %d sets.table[%d] >= %d",
745 					 cnt, i-1, tags->hdrs.size);
746 				*info = "failed verification tagsets idx out of bounds";
747 				return false;
748 			}
749 		}
750 	}
751 	for (i = 0; i < tags->hdrs.size; i++) {
752 		u32 idx = tags->hdrs.table[i].tags;
753 
754 		if (idx >= tags->strs.size) {
755 			AA_DEBUG(DEBUG_UNPACK,
756 				 "tag.hdrs idx oob idx %d > tags->strs.size=%d",
757 				 idx, tags->strs.size);
758 			*info = "failed verification tags.hdrs idx out of bounds";
759 			return false;
760 		}
761 		if (tags->hdrs.table[i].count != tags->strs.table[idx].count) {
762 			AA_DEBUG(DEBUG_UNPACK, "hdrs.table[%d].count=%d != tags->strs.table[%d]=%d",
763 				 i, tags->hdrs.table[i].count, idx, tags->strs.table[idx].count);
764 			*info = "failed verification tagd.hdrs[idx].count";
765 			return false;
766 		}
767 		if (tags->hdrs.table[i].size != tags->strs.table[idx].size) {
768 			AA_DEBUG(DEBUG_UNPACK, "hdrs.table[%d].size=%d != strs.table[%d].size=%d",
769 				 i, tags->hdrs.table[i].size, idx, tags->strs.table[idx].size);
770 			*info = "failed verification tagd.hdrs[idx].size";
771 			return false;
772 		}
773 	}
774 
775 	return true;
776 }
777 
unpack_tagsets(struct aa_ext * e,struct aa_tags_struct * tags)778 static int unpack_tagsets(struct aa_ext *e, struct aa_tags_struct *tags)
779 {
780 	u32 *sets;
781 	u16 i, size;
782 	int error = -EPROTO;
783 	void *pos = e->pos;
784 
785 	if (!aa_unpack_array(e, "sets", &size))
786 		goto fail_reset;
787 	sets = kcalloc(size, sizeof(u32), GFP_KERNEL);
788 	if (!sets) {
789 		error = -ENOMEM;
790 		goto fail_reset;
791 	}
792 	for (i = 0; i < size; i++) {
793 		if (!aa_unpack_u32(e, &sets[i], NULL))
794 			goto fail;
795 	}
796 	if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
797 		goto fail;
798 
799 	tags->sets.size = size;
800 	tags->sets.table = sets;
801 
802 	return 0;
803 
804 fail:
805 	kfree_sensitive(sets);
806 fail_reset:
807 	e->pos = pos;
808 	return error;
809 }
810 
unpack_tag_header_ent(struct aa_ext * e,struct aa_tags_header * h)811 static bool unpack_tag_header_ent(struct aa_ext *e, struct aa_tags_header *h)
812 {
813 	return aa_unpack_u32(e, &h->mask, NULL) &&
814 		aa_unpack_u32(e, &h->count, NULL) &&
815 		aa_unpack_u32(e, &h->size, NULL) &&
816 		aa_unpack_u32(e, &h->tags, NULL);
817 }
818 
unpack_tag_headers(struct aa_ext * e,struct aa_tags_struct * tags)819 static int unpack_tag_headers(struct aa_ext *e, struct aa_tags_struct *tags)
820 {
821 	struct aa_tags_header *hdrs;
822 	u16 i, size;
823 	int error = -EPROTO;
824 	void *pos = e->pos;
825 
826 	if (!aa_unpack_array(e, "hdrs", &size))
827 		goto fail_reset;
828 	hdrs = kzalloc_objs(struct aa_tags_header, size);
829 	if (!hdrs) {
830 		error = -ENOMEM;
831 		goto fail_reset;
832 	}
833 	for (i = 0; i < size; i++) {
834 		if (!unpack_tag_header_ent(e, &hdrs[i]))
835 			goto fail;
836 	}
837 	if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
838 		goto fail;
839 
840 	tags->hdrs.size = size;
841 	tags->hdrs.table = hdrs;
842 	AA_DEBUG(DEBUG_UNPACK, "headers %ld size %d", (long) hdrs, size);
843 	return true;
844 
845 fail:
846 	kfree_sensitive(hdrs);
847 fail_reset:
848 	e->pos = pos;
849 	return error;
850 }
851 
852 
unpack_tags(struct aa_ext * e,struct aa_tags_struct * tags,const char ** info)853 static int unpack_tags(struct aa_ext *e, struct aa_tags_struct *tags,
854 	const char **info)
855 {
856 	int error = -EPROTO;
857 	void *pos = e->pos;
858 
859 	AA_BUG(!tags);
860 	/* policy tags are optional */
861 	if (aa_unpack_nameX(e, AA_STRUCT, "tags")) {
862 		u32 version;
863 
864 		if (!aa_unpack_u32(e, &version, "version") || version != 1) {
865 			*info = "invalid tags version";
866 			goto fail_reset;
867 		}
868 		error = unpack_strs_table(e, "strs", true, &tags->strs);
869 		if (error) {
870 			*info = "failed to unpack profile tag.strs";
871 			goto fail;
872 		}
873 		error = unpack_tag_headers(e, tags);
874 		if (error) {
875 			*info = "failed to unpack profile tag.headers";
876 			goto fail;
877 		}
878 		error = unpack_tagsets(e, tags);
879 		if (error) {
880 			*info = "failed to unpack profile tag.sets";
881 			goto fail;
882 		}
883 		error = -EPROTO;
884 		if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
885 			goto fail;
886 
887 		if (!verify_tags(tags, info))
888 			goto fail;
889 	}
890 
891 	return 0;
892 
893 fail:
894 	aa_destroy_tags(tags);
895 fail_reset:
896 	e->pos = pos;
897 	return error;
898 }
899 
unpack_perm(struct aa_ext * e,u32 version,struct aa_perms * perm)900 static bool unpack_perm(struct aa_ext *e, u32 version, struct aa_perms *perm)
901 {
902 	u32 reserved;
903 
904 	if (version != 1)
905 		return false;
906 
907 	/* reserved entry is for later expansion, discard for now */
908 	return	aa_unpack_u32(e, &reserved, NULL) &&
909 		aa_unpack_u32(e, &perm->allow, NULL) &&
910 		aa_unpack_u32(e, &perm->deny, NULL) &&
911 		aa_unpack_u32(e, &perm->subtree, NULL) &&
912 		aa_unpack_u32(e, &perm->cond, NULL) &&
913 		aa_unpack_u32(e, &perm->kill, NULL) &&
914 		aa_unpack_u32(e, &perm->complain, NULL) &&
915 		aa_unpack_u32(e, &perm->prompt, NULL) &&
916 		aa_unpack_u32(e, &perm->audit, NULL) &&
917 		aa_unpack_u32(e, &perm->quiet, NULL) &&
918 		aa_unpack_u32(e, &perm->hide, NULL) &&
919 		aa_unpack_u32(e, &perm->xindex, NULL) &&
920 		aa_unpack_u32(e, &perm->tag, NULL) &&
921 		aa_unpack_u32(e, &perm->label, NULL);
922 }
923 
unpack_perms_table(struct aa_ext * e,struct aa_perms ** perms)924 static ssize_t unpack_perms_table(struct aa_ext *e, struct aa_perms **perms)
925 {
926 	void *pos = e->pos;
927 	u16 size = 0;
928 
929 	AA_BUG(!perms);
930 	/*
931 	 * policy perms are optional, in which case perms are embedded
932 	 * in the dfa accept table
933 	 */
934 	if (aa_unpack_nameX(e, AA_STRUCT, "perms")) {
935 		int i;
936 		u32 version;
937 
938 		if (!aa_unpack_u32(e, &version, "version"))
939 			goto fail_reset;
940 		if (!aa_unpack_array(e, NULL, &size))
941 			goto fail_reset;
942 		*perms = kzalloc_objs(struct aa_perms, size);
943 		if (!*perms) {
944 			e->pos = pos;
945 			return -ENOMEM;
946 		}
947 		for (i = 0; i < size; i++) {
948 			if (!unpack_perm(e, version, &(*perms)[i]))
949 				goto fail;
950 		}
951 		if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
952 			goto fail;
953 		if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
954 			goto fail;
955 	} else
956 		*perms = NULL;
957 
958 	return size;
959 
960 fail:
961 	kfree(*perms);
962 fail_reset:
963 	e->pos = pos;
964 	return -EPROTO;
965 }
966 
unpack_pdb(struct aa_ext * e,struct aa_policydb ** policy,bool required_dfa,bool required_trans,const char ** info)967 static int unpack_pdb(struct aa_ext *e, struct aa_policydb **policy,
968 		      bool required_dfa, bool required_trans,
969 		      const char **info)
970 {
971 	struct aa_policydb *pdb;
972 	void *pos = e->pos;
973 	int i, flags, error = -EPROTO;
974 	ssize_t size;
975 	u32 version = 0;
976 
977 	pdb = aa_alloc_pdb(GFP_KERNEL);
978 	if (!pdb)
979 		return -ENOMEM;
980 
981 	AA_DEBUG(DEBUG_UNPACK, "unpacking tags");
982 	if (unpack_tags(e, &pdb->tags, info) < 0)
983 		goto fail;
984 	AA_DEBUG(DEBUG_UNPACK, "done unpacking tags");
985 
986 	size = unpack_perms_table(e, &pdb->perms);
987 	if (size < 0) {
988 		error = size;
989 		pdb->perms = NULL;
990 		*info = "failed to unpack - perms";
991 		goto fail;
992 	}
993 	pdb->size = size;
994 
995 	if (pdb->perms) {
996 		/* perms table present accept is index */
997 		flags = TO_ACCEPT1_FLAG(YYTD_DATA32);
998 		if (aa_unpack_u32(e, &version, "permsv") && version > 2)
999 			/* accept2 used for dfa flags */
1000 			flags |= TO_ACCEPT2_FLAG(YYTD_DATA32);
1001 	} else {
1002 		/* packed perms in accept1 and accept2 */
1003 		flags = TO_ACCEPT1_FLAG(YYTD_DATA32) |
1004 			TO_ACCEPT2_FLAG(YYTD_DATA32);
1005 	}
1006 
1007 	pdb->dfa = unpack_dfa(e, flags);
1008 	if (IS_ERR(pdb->dfa)) {
1009 		error = PTR_ERR(pdb->dfa);
1010 		pdb->dfa = NULL;
1011 		*info = "failed to unpack - dfa";
1012 		goto fail;
1013 	} else if (!pdb->dfa) {
1014 		if (required_dfa) {
1015 			*info = "missing required dfa";
1016 			goto fail;
1017 		}
1018 	} else {
1019 		/*
1020 		 * only unpack the following if a dfa is present
1021 		 *
1022 		 * sadly start was given different names for file and policydb
1023 		 * but since it is optional we can try both
1024 		 */
1025 		if (!aa_unpack_u32(e, &pdb->start[0], "start"))
1026 			/* default start state */
1027 			pdb->start[0] = DFA_START;
1028 		if (!aa_unpack_u32(e, &pdb->start[AA_CLASS_FILE], "dfa_start")) {
1029 			/* default start state for xmatch and file dfa */
1030 			pdb->start[AA_CLASS_FILE] = DFA_START;
1031 		}
1032 
1033 		size_t state_count = pdb->dfa->tables[YYTD_ID_BASE]->td_lolen;
1034 
1035 		if (pdb->start[0] >= state_count ||
1036 		    pdb->start[AA_CLASS_FILE] >= state_count) {
1037 			*info = "invalid dfa start state";
1038 			goto fail;
1039 		}
1040 
1041 		/* setup class index */
1042 		for (i = AA_CLASS_FILE + 1; i <= AA_CLASS_LAST; i++) {
1043 			pdb->start[i] = aa_dfa_next(pdb->dfa, pdb->start[0],
1044 						    i);
1045 		}
1046 	}
1047 
1048 	/* accept2 is in some cases being allocated, even with perms */
1049 	if (pdb->dfa && pdb->perms && !pdb->dfa->tables[YYTD_ID_ACCEPT2]) {
1050 		/* add dfa flags table missing in v2 */
1051 		u32 noents = pdb->dfa->tables[YYTD_ID_ACCEPT]->td_lolen;
1052 		u16 tdflags = pdb->dfa->tables[YYTD_ID_ACCEPT]->td_flags;
1053 		size_t tsize = table_size(noents, tdflags);
1054 
1055 		pdb->dfa->tables[YYTD_ID_ACCEPT2] = kvzalloc(tsize, GFP_KERNEL);
1056 		if (!pdb->dfa->tables[YYTD_ID_ACCEPT2]) {
1057 			*info = "failed to alloc dfa flags table";
1058 			error = -ENOMEM;
1059 			goto fail;
1060 		}
1061 		pdb->dfa->tables[YYTD_ID_ACCEPT2]->td_lolen = noents;
1062 		pdb->dfa->tables[YYTD_ID_ACCEPT2]->td_flags = tdflags;
1063 	}
1064 	/*
1065 	 * Unfortunately due to a bug in earlier userspaces, a
1066 	 * transition table may be present even when the dfa is
1067 	 * not. For compatibility reasons unpack and discard.
1068 	 */
1069 	error = unpack_strs_table(e, "xtable", false, &pdb->trans);
1070 	if (error && required_trans) {
1071 		*info = "failed to unpack profile transition table";
1072 		goto fail;
1073 	}
1074 
1075 	if (!pdb->dfa && pdb->trans.table)
1076 		aa_destroy_str_table(&pdb->trans);
1077 
1078 	/* TODO:
1079 	 * - move compat mapping here, requires dfa merging first
1080 	 * - move verify here, it has to be done after compat mappings
1081 	 * - move free of unneeded trans table here, has to be done
1082 	 *   after perm mapping.
1083 	 */
1084 	*policy = pdb;
1085 	return 0;
1086 
1087 fail:
1088 	aa_put_pdb(pdb);
1089 	e->pos = pos;
1090 	return error;
1091 }
1092 
strhash(const void * data,u32 len,u32 seed)1093 static u32 strhash(const void *data, u32 len, u32 seed)
1094 {
1095 	const char * const *key = data;
1096 
1097 	return jhash(*key, strlen(*key), seed);
1098 }
1099 
datacmp(struct rhashtable_compare_arg * arg,const void * obj)1100 static int datacmp(struct rhashtable_compare_arg *arg, const void *obj)
1101 {
1102 	const struct aa_data *data = obj;
1103 	const char * const *key = arg->key;
1104 
1105 	return strcmp(data->key, *key);
1106 }
1107 
1108 /**
1109  * unpack_profile - unpack a serialized profile
1110  * @e: serialized data extent information (NOT NULL)
1111  * @ns_name: pointer of newly allocated copy of %NULL in case of error
1112  *
1113  * NOTE: unpack profile sets audit struct if there is a failure
1114  */
unpack_profile(struct aa_ext * e,char ** ns_name)1115 static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
1116 {
1117 	struct aa_ruleset *rules;
1118 	struct aa_profile *profile = NULL;
1119 	const char *tmpname, *tmpns = NULL, *name = NULL;
1120 	const char *info = "failed to unpack profile";
1121 	size_t ns_len;
1122 	struct rhashtable_params params = { 0 };
1123 	char *key = NULL, *disconnected = NULL;
1124 	struct aa_data *data;
1125 	int error = -EPROTO;
1126 	kernel_cap_t tmpcap;
1127 	u32 tmp;
1128 
1129 	*ns_name = NULL;
1130 
1131 	/* check that we have the right struct being passed */
1132 	if (!aa_unpack_nameX(e, AA_STRUCT, "profile"))
1133 		goto fail;
1134 	if (!aa_unpack_str(e, &name, NULL))
1135 		goto fail;
1136 	if (*name == '\0')
1137 		goto fail;
1138 
1139 	tmpname = aa_splitn_fqname(name, strlen(name), &tmpns, &ns_len);
1140 	if (tmpns) {
1141 		if (!tmpname) {
1142 			info = "empty profile name";
1143 			goto fail;
1144 		}
1145 		*ns_name = kstrndup(tmpns, ns_len, GFP_KERNEL);
1146 		if (!*ns_name) {
1147 			info = "out of memory";
1148 			error = -ENOMEM;
1149 			goto fail;
1150 		}
1151 		name = tmpname;
1152 	}
1153 
1154 	profile = aa_alloc_profile(name, NULL, GFP_KERNEL);
1155 	if (!profile) {
1156 		info = "out of memory";
1157 		error = -ENOMEM;
1158 		goto fail;
1159 	}
1160 	rules = profile->label.rules[0];
1161 
1162 	/* profile renaming is optional */
1163 	(void) aa_unpack_str(e, &profile->rename, "rename");
1164 
1165 	/* attachment string is optional */
1166 	(void) aa_unpack_str(e, &profile->attach.xmatch_str, "attach");
1167 
1168 	/* xmatch is optional and may be NULL */
1169 	error = unpack_pdb(e, &profile->attach.xmatch, false, false, &info);
1170 	if (error) {
1171 		info = "bad xmatch";
1172 		goto fail;
1173 	}
1174 
1175 	/* neither xmatch_len not xmatch_perms are optional if xmatch is set */
1176 	if (profile->attach.xmatch->dfa) {
1177 		if (!aa_unpack_u32(e, &tmp, NULL)) {
1178 			info = "missing xmatch len";
1179 			goto fail;
1180 		}
1181 		profile->attach.xmatch_len = tmp;
1182 		profile->attach.xmatch->start[AA_CLASS_XMATCH] = DFA_START;
1183 		if (!profile->attach.xmatch->perms) {
1184 			error = aa_compat_map_xmatch(profile->attach.xmatch);
1185 			if (error) {
1186 				info = "failed to convert xmatch permission table";
1187 				goto fail;
1188 			}
1189 		}
1190 	}
1191 
1192 	/* disconnected attachment string is optional */
1193 	(void) aa_unpack_strdup(e, &disconnected, "disconnected");
1194 	profile->disconnected = disconnected;
1195 
1196 	/* optional */
1197 	(void) aa_unpack_u32(e, &profile->signal, "kill");
1198 	if (profile->signal < 1 || profile->signal > MAXMAPPED_SIG) {
1199 		info = "profile kill.signal invalid value";
1200 		goto fail;
1201 	}
1202 	/* per profile debug flags (complain, audit) */
1203 	if (!aa_unpack_nameX(e, AA_STRUCT, "flags")) {
1204 		info = "profile missing flags";
1205 		goto fail;
1206 	}
1207 	info = "failed to unpack profile flags";
1208 	if (!aa_unpack_u32(e, &tmp, NULL))
1209 		goto fail;
1210 	if (tmp & PACKED_FLAG_HAT)
1211 		profile->label.flags |= FLAG_HAT;
1212 	if (tmp & PACKED_FLAG_DEBUG1)
1213 		profile->label.flags |= FLAG_DEBUG1;
1214 	if (tmp & PACKED_FLAG_DEBUG2)
1215 		profile->label.flags |= FLAG_DEBUG2;
1216 	if (!aa_unpack_u32(e, &tmp, NULL))
1217 		goto fail;
1218 	if (tmp == PACKED_MODE_COMPLAIN || (e->version & FORCE_COMPLAIN_FLAG)) {
1219 		profile->mode = APPARMOR_COMPLAIN;
1220 	} else if (tmp == PACKED_MODE_ENFORCE) {
1221 		profile->mode = APPARMOR_ENFORCE;
1222 	} else if (tmp == PACKED_MODE_KILL) {
1223 		profile->mode = APPARMOR_KILL;
1224 	} else if (tmp == PACKED_MODE_UNCONFINED) {
1225 		profile->mode = APPARMOR_UNCONFINED;
1226 		profile->label.flags |= FLAG_UNCONFINED;
1227 	} else if (tmp == PACKED_MODE_USER) {
1228 		profile->mode = APPARMOR_USER;
1229 	} else {
1230 		goto fail;
1231 	}
1232 	if (!aa_unpack_u32(e, &tmp, NULL))
1233 		goto fail;
1234 	if (tmp)
1235 		profile->audit = AUDIT_ALL;
1236 
1237 	if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
1238 		goto fail;
1239 
1240 	/* path_flags is optional */
1241 	if (aa_unpack_u32(e, &profile->path_flags, "path_flags"))
1242 		profile->path_flags |= profile->label.flags &
1243 			PATH_MEDIATE_DELETED;
1244 	else
1245 		/* set a default value if path_flags field is not present */
1246 		profile->path_flags = PATH_MEDIATE_DELETED;
1247 
1248 	info = "failed to unpack profile capabilities";
1249 	if (!aa_unpack_cap_low(e, &rules->caps.allow, NULL))
1250 		goto fail;
1251 	if (!aa_unpack_cap_low(e, &rules->caps.audit, NULL))
1252 		goto fail;
1253 	if (!aa_unpack_cap_low(e, &rules->caps.quiet, NULL))
1254 		goto fail;
1255 	if (!aa_unpack_cap_low(e, &tmpcap, NULL))
1256 		goto fail;
1257 
1258 	info = "failed to unpack upper profile capabilities";
1259 	if (aa_unpack_nameX(e, AA_STRUCT, "caps64")) {
1260 		/* optional upper half of 64 bit caps */
1261 		if (!aa_unpack_cap_high(e, &rules->caps.allow, NULL))
1262 			goto fail;
1263 		if (!aa_unpack_cap_high(e, &rules->caps.audit, NULL))
1264 			goto fail;
1265 		if (!aa_unpack_cap_high(e, &rules->caps.quiet, NULL))
1266 			goto fail;
1267 		if (!aa_unpack_cap_high(e, &tmpcap, NULL))
1268 			goto fail;
1269 		if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
1270 			goto fail;
1271 	}
1272 
1273 	info = "failed to unpack extended profile capabilities";
1274 	if (aa_unpack_nameX(e, AA_STRUCT, "capsx")) {
1275 		/* optional extended caps mediation mask */
1276 		if (!aa_unpack_cap_low(e, &rules->caps.extended, NULL))
1277 			goto fail;
1278 		if (!aa_unpack_cap_high(e, &rules->caps.extended, NULL))
1279 			goto fail;
1280 		if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
1281 			goto fail;
1282 	}
1283 
1284 	if (!unpack_xattrs(e, profile)) {
1285 		info = "failed to unpack profile xattrs";
1286 		goto fail;
1287 	}
1288 
1289 	if (!unpack_rlimits(e, rules)) {
1290 		info = "failed to unpack profile rlimits";
1291 		goto fail;
1292 	}
1293 
1294 	if (!unpack_secmark(e, rules)) {
1295 		info = "failed to unpack profile secmark rules";
1296 		goto fail;
1297 	}
1298 
1299 	if (aa_unpack_nameX(e, AA_STRUCT, "policydb")) {
1300 		/* generic policy dfa - optional and may be NULL */
1301 		info = "failed to unpack policydb";
1302 		error = unpack_pdb(e, &rules->policy, true, false,
1303 				   &info);
1304 		if (error)
1305 			goto fail;
1306 		/* Fixup: drop when we get rid of start array */
1307 		if (aa_dfa_next(rules->policy->dfa, rules->policy->start[0],
1308 				AA_CLASS_FILE))
1309 			rules->policy->start[AA_CLASS_FILE] =
1310 			  aa_dfa_next(rules->policy->dfa,
1311 				      rules->policy->start[0],
1312 				      AA_CLASS_FILE);
1313 		if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL))
1314 			goto fail;
1315 		if (!rules->policy->perms) {
1316 			error = aa_compat_map_policy(rules->policy,
1317 						     e->version);
1318 			if (error) {
1319 				info = "failed to remap policydb permission table";
1320 				goto fail;
1321 			}
1322 		}
1323 	} else {
1324 		rules->policy = aa_get_pdb(nullpdb);
1325 	}
1326 	/* get file rules */
1327 	error = unpack_pdb(e, &rules->file, false, true, &info);
1328 	if (error) {
1329 		goto fail;
1330 	} else if (rules->file->dfa) {
1331 		if (!rules->file->perms) {
1332 			AA_DEBUG(DEBUG_UNPACK, "compat mapping perms");
1333 			error = aa_compat_map_file(rules->file);
1334 			if (error) {
1335 				info = "failed to remap file permission table";
1336 				goto fail;
1337 			}
1338 		}
1339 	} else if (rules->policy->dfa &&
1340 		   rules->policy->start[AA_CLASS_FILE]) {
1341 		aa_put_pdb(rules->file);
1342 		rules->file = aa_get_pdb(rules->policy);
1343 	} else {
1344 		aa_put_pdb(rules->file);
1345 		rules->file = aa_get_pdb(nullpdb);
1346 	}
1347 	error = -EPROTO;
1348 	if (aa_unpack_nameX(e, AA_STRUCT, "data")) {
1349 		info = "out of memory";
1350 		profile->data = kzalloc_obj(*profile->data);
1351 		if (!profile->data) {
1352 			error = -ENOMEM;
1353 			goto fail;
1354 		}
1355 		params.nelem_hint = 3;
1356 		params.key_len = sizeof(void *);
1357 		params.key_offset = offsetof(struct aa_data, key);
1358 		params.head_offset = offsetof(struct aa_data, head);
1359 		params.hashfn = strhash;
1360 		params.obj_cmpfn = datacmp;
1361 
1362 		if (rhashtable_init(profile->data, &params)) {
1363 			info = "failed to init key, value hash table";
1364 			goto fail;
1365 		}
1366 
1367 		while (aa_unpack_strdup(e, &key, NULL)) {
1368 			data = kzalloc_obj(*data);
1369 			if (!data) {
1370 				kfree_sensitive(key);
1371 				error = -ENOMEM;
1372 				goto fail;
1373 			}
1374 
1375 			data->key = key;
1376 			data->size = aa_unpack_blob(e, &data->data, NULL);
1377 			data->data = kvmemdup(data->data, data->size, GFP_KERNEL);
1378 			if (data->size && !data->data) {
1379 				kfree_sensitive(data->key);
1380 				kfree_sensitive(data);
1381 				error = -ENOMEM;
1382 				goto fail;
1383 			}
1384 
1385 			if (rhashtable_insert_fast(profile->data, &data->head,
1386 						   profile->data->p)) {
1387 				kvfree_sensitive(data->data, data->size);
1388 				kfree_sensitive(data->key);
1389 				kfree_sensitive(data);
1390 				info = "failed to insert data to table";
1391 				goto fail;
1392 			}
1393 		}
1394 
1395 		if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) {
1396 			info = "failed to unpack end of key, value data table";
1397 			goto fail;
1398 		}
1399 	}
1400 
1401 	if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) {
1402 		info = "failed to unpack end of profile";
1403 		goto fail;
1404 	}
1405 
1406 	aa_compute_profile_mediates(profile);
1407 
1408 	return profile;
1409 
1410 fail:
1411 	if (error == 0)
1412 		/* default error covers most cases */
1413 		error = -EPROTO;
1414 	if (*ns_name) {
1415 		kfree(*ns_name);
1416 		*ns_name = NULL;
1417 	}
1418 	if (profile)
1419 		name = NULL;
1420 	else if (!name)
1421 		name = "unknown";
1422 	audit_iface(profile, NULL, name, info, e, error);
1423 	aa_free_profile(profile);
1424 
1425 	return ERR_PTR(error);
1426 }
1427 
1428 /**
1429  * verify_header - unpack serialized stream header
1430  * @e: serialized data read head (NOT NULL)
1431  * @required: whether the header is required or optional
1432  * @ns: Returns - namespace if one is specified else NULL (NOT NULL)
1433  *
1434  * Returns: error or 0 if header is good
1435  */
verify_header(struct aa_ext * e,int required,const char ** ns)1436 static int verify_header(struct aa_ext *e, int required, const char **ns)
1437 {
1438 	int error = -EPROTONOSUPPORT;
1439 	const char *name = NULL;
1440 
1441 	/* get the interface version */
1442 	if (!aa_unpack_u32(e, &e->version, "version")) {
1443 		if (required) {
1444 			audit_iface(NULL, NULL, NULL, "invalid profile format",
1445 				    e, error);
1446 			return error;
1447 		}
1448 	}
1449 
1450 	/* Check that the interface version is currently supported.
1451 	 * if not specified use previous version
1452 	 * Mask off everything that is not kernel abi version
1453 	 */
1454 	if (VERSION_LT(e->version, v5) || VERSION_GT(e->version, v9)) {
1455 		audit_iface(NULL, NULL, NULL, "unsupported interface version",
1456 			    e, error);
1457 		return error;
1458 	}
1459 
1460 	/* read the namespace if present */
1461 	if (aa_unpack_str(e, &name, "namespace")) {
1462 		if (*name == '\0') {
1463 			audit_iface(NULL, NULL, NULL, "invalid namespace name",
1464 				    e, error);
1465 			return error;
1466 		}
1467 		if (*ns && strcmp(*ns, name)) {
1468 			audit_iface(NULL, NULL, NULL, "invalid ns change", e,
1469 				    error);
1470 			return error;
1471 		} else if (!*ns) {
1472 			*ns = kstrdup(name, GFP_KERNEL);
1473 			if (!*ns)
1474 				return -ENOMEM;
1475 		}
1476 	}
1477 
1478 	return 0;
1479 }
1480 
1481 /**
1482  * verify_dfa_accept_index - verify accept indexes are in range of perms table
1483  * @dfa: the dfa to check accept indexes are in range
1484  * @table_size: the permission table size the indexes should be within
1485  */
verify_dfa_accept_index(const struct aa_dfa * dfa,int table_size)1486 static bool verify_dfa_accept_index(const struct aa_dfa *dfa, int table_size)
1487 {
1488 	int i;
1489 	for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
1490 		if (ACCEPT_TABLE(dfa)[i] >= table_size)
1491 			return false;
1492 	}
1493 	return true;
1494 }
1495 
verify_perm(const struct aa_perms * perm)1496 static bool verify_perm(const struct aa_perms *perm)
1497 {
1498 	/* TODO: allow option to just force the perms into a valid state */
1499 	if (perm->allow & perm->deny)
1500 		return false;
1501 	if (perm->subtree & ~perm->allow)
1502 		return false;
1503 	if (perm->cond & (perm->allow | perm->deny))
1504 		return false;
1505 	if (perm->kill & perm->allow)
1506 		return false;
1507 	if (perm->complain & (perm->allow | perm->deny))
1508 		return false;
1509 	if (perm->prompt & (perm->allow | perm->deny))
1510 		return false;
1511 	if (perm->complain & perm->prompt)
1512 		return false;
1513 	if (perm->hide & perm->allow)
1514 		return false;
1515 
1516 	return true;
1517 }
1518 
verify_perms(struct aa_policydb * pdb)1519 static bool verify_perms(struct aa_policydb *pdb)
1520 {
1521 	int i;
1522 	int xidx, xmax = -1;
1523 
1524 	for (i = 0; i < pdb->size; i++) {
1525 		if (!verify_perm(&pdb->perms[i]))
1526 			return false;
1527 		/* verify indexes into str table */
1528 		if ((pdb->perms[i].xindex & AA_X_TYPE_MASK) == AA_X_TABLE) {
1529 			xidx = pdb->perms[i].xindex & AA_X_INDEX_MASK;
1530 			if (xidx >= pdb->trans.size)
1531 				return false;
1532 			if (xmax < xidx)
1533 				xmax = xidx;
1534 		}
1535 		if (pdb->perms[i].tag && pdb->perms[i].tag >= pdb->tags.sets.size)
1536 			return false;
1537 		if (pdb->perms[i].label &&
1538 		    pdb->perms[i].label >= pdb->trans.size)
1539 			return false;
1540 	}
1541 	/* deal with incorrectly constructed string tables */
1542 	if (xmax == -1) {
1543 		aa_destroy_str_table(&pdb->trans);
1544 	} else if (pdb->trans.size > xmax + 1) {
1545 		if (!aa_resize_str_table(&pdb->trans, xmax + 1, GFP_KERNEL))
1546 			return false;
1547 	}
1548 	return true;
1549 }
1550 
1551 /**
1552  * verify_profile - Do post unpack analysis to verify profile consistency
1553  * @profile: profile to verify (NOT NULL)
1554  *
1555  * Returns: 0 if passes verification else error
1556  *
1557  * This verification is post any unpack mapping or changes
1558  */
verify_profile(struct aa_profile * profile)1559 static int verify_profile(struct aa_profile *profile)
1560 {
1561 	struct aa_ruleset *rules = profile->label.rules[0];
1562 
1563 	if (!rules)
1564 		return 0;
1565 
1566 	if (rules->file->dfa && !verify_dfa_accept_index(rules->file->dfa,
1567 							rules->file->size)) {
1568 		audit_iface(profile, NULL, NULL,
1569 			    "Unpack: file Invalid named transition", NULL,
1570 			    -EPROTO);
1571 		return -EPROTO;
1572 	}
1573 	if (rules->policy->dfa &&
1574 	    !verify_dfa_accept_index(rules->policy->dfa, rules->policy->size)) {
1575 		audit_iface(profile, NULL, NULL,
1576 			    "Unpack: policy Invalid named transition", NULL,
1577 			    -EPROTO);
1578 		return -EPROTO;
1579 	}
1580 
1581 	if (!verify_perms(rules->file)) {
1582 		audit_iface(profile, NULL, NULL,
1583 			    "Unpack: Invalid perm index", NULL, -EPROTO);
1584 		return -EPROTO;
1585 	}
1586 	if (!verify_perms(rules->policy)) {
1587 		audit_iface(profile, NULL, NULL,
1588 			    "Unpack: Invalid perm index", NULL, -EPROTO);
1589 		return -EPROTO;
1590 	}
1591 	if (!verify_perms(profile->attach.xmatch)) {
1592 		audit_iface(profile, NULL, NULL,
1593 			    "Unpack: Invalid perm index", NULL, -EPROTO);
1594 		return -EPROTO;
1595 	}
1596 
1597 	return 0;
1598 }
1599 
aa_load_ent_free(struct aa_load_ent * ent)1600 void aa_load_ent_free(struct aa_load_ent *ent)
1601 {
1602 	if (ent) {
1603 		aa_put_profile(ent->rename);
1604 		aa_put_profile(ent->old);
1605 		aa_put_profile(ent->new);
1606 		kfree(ent->ns_name);
1607 		kfree_sensitive(ent);
1608 	}
1609 }
1610 
aa_load_ent_alloc(void)1611 struct aa_load_ent *aa_load_ent_alloc(void)
1612 {
1613 	struct aa_load_ent *ent = kzalloc_obj(*ent);
1614 	if (ent)
1615 		INIT_LIST_HEAD(&ent->list);
1616 	return ent;
1617 }
1618 
compress_zstd(const char * src,size_t slen,char ** dst,size_t * dlen)1619 static int compress_zstd(const char *src, size_t slen, char **dst, size_t *dlen)
1620 {
1621 #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY
1622 	const zstd_parameters params =
1623 		zstd_get_params(aa_g_rawdata_compression_level, slen);
1624 	const size_t wksp_len = zstd_cctx_workspace_bound(&params.cParams);
1625 	void *wksp = NULL;
1626 	zstd_cctx *ctx = NULL;
1627 	size_t out_len = zstd_compress_bound(slen);
1628 	void *out = NULL;
1629 	int ret = 0;
1630 
1631 	out = kvzalloc(out_len, GFP_KERNEL);
1632 	if (!out) {
1633 		ret = -ENOMEM;
1634 		goto cleanup;
1635 	}
1636 
1637 	wksp = kvzalloc(wksp_len, GFP_KERNEL);
1638 	if (!wksp) {
1639 		ret = -ENOMEM;
1640 		goto cleanup;
1641 	}
1642 
1643 	ctx = zstd_init_cctx(wksp, wksp_len);
1644 	if (!ctx) {
1645 		ret = -EINVAL;
1646 		goto cleanup;
1647 	}
1648 
1649 	out_len = zstd_compress_cctx(ctx, out, out_len, src, slen, &params);
1650 	if (zstd_is_error(out_len) || out_len >= slen) {
1651 		ret = -EINVAL;
1652 		goto cleanup;
1653 	}
1654 
1655 	if (is_vmalloc_addr(out)) {
1656 		*dst = kvzalloc(out_len, GFP_KERNEL);
1657 		if (*dst) {
1658 			memcpy(*dst, out, out_len);
1659 			kvfree(out);
1660 			out = NULL;
1661 		}
1662 	} else {
1663 		/*
1664 		 * If the staging buffer was kmalloc'd, then using krealloc is
1665 		 * probably going to be faster. The destination buffer will
1666 		 * always be smaller, so it's just shrunk, avoiding a memcpy
1667 		 */
1668 		*dst = krealloc(out, out_len, GFP_KERNEL);
1669 	}
1670 
1671 	if (!*dst) {
1672 		ret = -ENOMEM;
1673 		goto cleanup;
1674 	}
1675 
1676 	*dlen = out_len;
1677 
1678 cleanup:
1679 	if (ret) {
1680 		kvfree(out);
1681 		*dst = NULL;
1682 	}
1683 
1684 	kvfree(wksp);
1685 	return ret;
1686 #else
1687 	*dlen = slen;
1688 	return 0;
1689 #endif
1690 }
1691 
compress_loaddata(struct aa_loaddata * data)1692 static int compress_loaddata(struct aa_loaddata *data)
1693 {
1694 	AA_BUG(data->compressed_size > 0);
1695 
1696 	/*
1697 	 * Shortcut the no compression case, else we increase the amount of
1698 	 * storage required by a small amount
1699 	 */
1700 	if (aa_g_rawdata_compression_level != 0) {
1701 		void *udata = data->data;
1702 		int error = compress_zstd(udata, data->size, &data->data,
1703 					  &data->compressed_size);
1704 		if (error) {
1705 			data->compressed_size = data->size;
1706 			return error;
1707 		}
1708 		if (udata != data->data)
1709 			kvfree(udata);
1710 	} else
1711 		data->compressed_size = data->size;
1712 
1713 	return 0;
1714 }
1715 
1716 /**
1717  * aa_unpack - unpack packed binary profile(s) data loaded from user space
1718  * @udata: user data copied to kmem  (NOT NULL)
1719  * @lh: list to place unpacked profiles in a aa_repl_ws
1720  * @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
1721  * @compressed_data: The userspace-provided compressed data. May be NULL
1722  * @compressed_size: If compressed_data is not NULL, the compressed data size
1723  *
1724  * Unpack user data and return refcounted allocated profile(s) stored in
1725  * @lh in order of discovery, with the list chain stored in base.list
1726  * or error
1727  *
1728  * Returns: profile(s) on @lh else error pointer if fails to unpack
1729  */
aa_unpack(struct aa_loaddata * udata,struct list_head * lh,const char ** ns,char * compressed_data,size_t compressed_size)1730 int aa_unpack(struct aa_loaddata *udata, struct list_head *lh,
1731 	      const char **ns, char *compressed_data, size_t compressed_size)
1732 {
1733 	struct aa_load_ent *tmp, *ent;
1734 	struct aa_profile *profile = NULL;
1735 	char *ns_name = NULL;
1736 	int error = 0;
1737 	struct aa_ext e = {
1738 		.start = udata->data,
1739 		.end = udata->data + udata->size,
1740 		.pos = udata->data,
1741 	};
1742 
1743 	*ns = NULL;
1744 	while (e.pos < e.end) {
1745 		void *start;
1746 		error = verify_header(&e, e.pos == e.start, ns);
1747 		if (error)
1748 			goto fail;
1749 
1750 		start = e.pos;
1751 		profile = unpack_profile(&e, &ns_name);
1752 		if (IS_ERR(profile)) {
1753 			error = PTR_ERR(profile);
1754 			goto fail;
1755 		}
1756 
1757 		error = verify_profile(profile);
1758 		if (error)
1759 			goto fail_profile;
1760 
1761 		if (aa_g_hash_policy)
1762 			error = aa_calc_profile_hash(profile, e.version, start,
1763 						     e.pos - start);
1764 		if (error)
1765 			goto fail_profile;
1766 
1767 		ent = aa_load_ent_alloc();
1768 		if (!ent) {
1769 			error = -ENOMEM;
1770 			goto fail_profile;
1771 		}
1772 
1773 		ent->new = profile;
1774 		ent->ns_name = ns_name;
1775 		ns_name = NULL;
1776 		list_add_tail(&ent->list, lh);
1777 	}
1778 	udata->abi = e.version & K_ABI_MASK;
1779 	if (aa_g_hash_policy) {
1780 		udata->hash = aa_calc_hash(udata->data, udata->size);
1781 		if (IS_ERR(udata->hash)) {
1782 			error = PTR_ERR(udata->hash);
1783 			udata->hash = NULL;
1784 			goto fail;
1785 		}
1786 	}
1787 
1788 	if (aa_g_export_binary) {
1789 		/* Do we have userspace-compressed data? */
1790 		if (compressed_data) {
1791 			kvfree(udata->data);
1792 			udata->data = compressed_data;
1793 			udata->compressed_size = compressed_size;
1794 			compressed_data = NULL; /* consumed */
1795 
1796 		} else
1797 			error = compress_loaddata(udata);
1798 
1799 		if (error)
1800 			goto fail;
1801 	} else if (compressed_data) {
1802 		kvfree(compressed_data);
1803 		compressed_data = NULL;
1804 	}
1805 
1806 	return 0;
1807 
1808 fail_profile:
1809 	kfree(ns_name);
1810 	aa_put_profile(profile);
1811 
1812 fail:
1813 	if (compressed_data)
1814 		kvfree(compressed_data);
1815 	list_for_each_entry_safe(ent, tmp, lh, list) {
1816 		list_del_init(&ent->list);
1817 		aa_load_ent_free(ent);
1818 	}
1819 
1820 	return error;
1821 }
1822