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 <asm/unaligned.h>
17 #include <linux/ctype.h>
18 #include <linux/errno.h>
19 #include <linux/zlib.h>
20 
21 #include "include/apparmor.h"
22 #include "include/audit.h"
23 #include "include/cred.h"
24 #include "include/crypto.h"
25 #include "include/match.h"
26 #include "include/path.h"
27 #include "include/policy.h"
28 #include "include/policy_unpack.h"
29 
30 #define K_ABI_MASK 0x3ff
31 #define FORCE_COMPLAIN_FLAG 0x800
32 #define VERSION_LT(X, Y) (((X) & K_ABI_MASK) < ((Y) & K_ABI_MASK))
33 #define VERSION_GT(X, Y) (((X) & K_ABI_MASK) > ((Y) & K_ABI_MASK))
34 
35 #define v5	5	/* base version */
36 #define v6	6	/* per entry policydb mediation check */
37 #define v7	7
38 #define v8	8	/* full network masking */
39 
40 /*
41  * The AppArmor interface treats data as a type byte followed by the
42  * actual data.  The interface has the notion of a named entry
43  * which has a name (AA_NAME typecode followed by name string) followed by
44  * the entries typecode and data.  Named types allow for optional
45  * elements and extensions to be added and tested for without breaking
46  * backwards compatibility.
47  */
48 
49 enum aa_code {
50 	AA_U8,
51 	AA_U16,
52 	AA_U32,
53 	AA_U64,
54 	AA_NAME,		/* same as string except it is items name */
55 	AA_STRING,
56 	AA_BLOB,
57 	AA_STRUCT,
58 	AA_STRUCTEND,
59 	AA_LIST,
60 	AA_LISTEND,
61 	AA_ARRAY,
62 	AA_ARRAYEND,
63 };
64 
65 /*
66  * aa_ext is the read of the buffer containing the serialized profile.  The
67  * data is copied into a kernel buffer in apparmorfs and then handed off to
68  * the unpack routines.
69  */
70 struct aa_ext {
71 	void *start;
72 	void *end;
73 	void *pos;		/* pointer to current position in the buffer */
74 	u32 version;
75 };
76 
77 /* audit callback for unpack fields */
audit_cb(struct audit_buffer * ab,void * va)78 static void audit_cb(struct audit_buffer *ab, void *va)
79 {
80 	struct common_audit_data *sa = va;
81 
82 	if (aad(sa)->iface.ns) {
83 		audit_log_format(ab, " ns=");
84 		audit_log_untrustedstring(ab, aad(sa)->iface.ns);
85 	}
86 	if (aad(sa)->name) {
87 		audit_log_format(ab, " name=");
88 		audit_log_untrustedstring(ab, aad(sa)->name);
89 	}
90 	if (aad(sa)->iface.pos)
91 		audit_log_format(ab, " offset=%ld", aad(sa)->iface.pos);
92 }
93 
94 /**
95  * audit_iface - do audit message for policy unpacking/load/replace/remove
96  * @new: profile if it has been allocated (MAYBE NULL)
97  * @ns_name: name of the ns the profile is to be loaded to (MAY BE NULL)
98  * @name: name of the profile being manipulated (MAYBE NULL)
99  * @info: any extra info about the failure (MAYBE NULL)
100  * @e: buffer position info
101  * @error: error code
102  *
103  * Returns: %0 or error
104  */
audit_iface(struct aa_profile * new,const char * ns_name,const char * name,const char * info,struct aa_ext * e,int error)105 static int audit_iface(struct aa_profile *new, const char *ns_name,
106 		       const char *name, const char *info, struct aa_ext *e,
107 		       int error)
108 {
109 	struct aa_profile *profile = labels_profile(aa_current_raw_label());
110 	DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, NULL);
111 	if (e)
112 		aad(&sa)->iface.pos = e->pos - e->start;
113 	aad(&sa)->iface.ns = ns_name;
114 	if (new)
115 		aad(&sa)->name = new->base.hname;
116 	else
117 		aad(&sa)->name = name;
118 	aad(&sa)->info = info;
119 	aad(&sa)->error = error;
120 
121 	return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb);
122 }
123 
__aa_loaddata_update(struct aa_loaddata * data,long revision)124 void __aa_loaddata_update(struct aa_loaddata *data, long revision)
125 {
126 	AA_BUG(!data);
127 	AA_BUG(!data->ns);
128 	AA_BUG(!mutex_is_locked(&data->ns->lock));
129 	AA_BUG(data->revision > revision);
130 
131 	data->revision = revision;
132 	if ((data->dents[AAFS_LOADDATA_REVISION])) {
133 		d_inode(data->dents[AAFS_LOADDATA_DIR])->i_mtime =
134 			current_time(d_inode(data->dents[AAFS_LOADDATA_DIR]));
135 		d_inode(data->dents[AAFS_LOADDATA_REVISION])->i_mtime =
136 			current_time(d_inode(data->dents[AAFS_LOADDATA_REVISION]));
137 	}
138 }
139 
aa_rawdata_eq(struct aa_loaddata * l,struct aa_loaddata * r)140 bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r)
141 {
142 	if (l->size != r->size)
143 		return false;
144 	if (l->compressed_size != r->compressed_size)
145 		return false;
146 	if (aa_g_hash_policy && memcmp(l->hash, r->hash, aa_hash_size()) != 0)
147 		return false;
148 	return memcmp(l->data, r->data, r->compressed_size ?: r->size) == 0;
149 }
150 
151 /*
152  * need to take the ns mutex lock which is NOT safe most places that
153  * put_loaddata is called, so we have to delay freeing it
154  */
do_loaddata_free(struct work_struct * work)155 static void do_loaddata_free(struct work_struct *work)
156 {
157 	struct aa_loaddata *d = container_of(work, struct aa_loaddata, work);
158 	struct aa_ns *ns = aa_get_ns(d->ns);
159 
160 	if (ns) {
161 		mutex_lock_nested(&ns->lock, ns->level);
162 		__aa_fs_remove_rawdata(d);
163 		mutex_unlock(&ns->lock);
164 		aa_put_ns(ns);
165 	}
166 
167 	kfree_sensitive(d->hash);
168 	kfree_sensitive(d->name);
169 	kvfree(d->data);
170 	kfree_sensitive(d);
171 }
172 
aa_loaddata_kref(struct kref * kref)173 void aa_loaddata_kref(struct kref *kref)
174 {
175 	struct aa_loaddata *d = container_of(kref, struct aa_loaddata, count);
176 
177 	if (d) {
178 		INIT_WORK(&d->work, do_loaddata_free);
179 		schedule_work(&d->work);
180 	}
181 }
182 
aa_loaddata_alloc(size_t size)183 struct aa_loaddata *aa_loaddata_alloc(size_t size)
184 {
185 	struct aa_loaddata *d;
186 
187 	d = kzalloc(sizeof(*d), GFP_KERNEL);
188 	if (d == NULL)
189 		return ERR_PTR(-ENOMEM);
190 	d->data = kvzalloc(size, GFP_KERNEL);
191 	if (!d->data) {
192 		kfree(d);
193 		return ERR_PTR(-ENOMEM);
194 	}
195 	kref_init(&d->count);
196 	INIT_LIST_HEAD(&d->list);
197 
198 	return d;
199 }
200 
201 /* test if read will be in packed data bounds */
inbounds(struct aa_ext * e,size_t size)202 static bool inbounds(struct aa_ext *e, size_t size)
203 {
204 	return (size <= e->end - e->pos);
205 }
206 
kvmemdup(const void * src,size_t len)207 static void *kvmemdup(const void *src, size_t len)
208 {
209 	void *p = kvmalloc(len, GFP_KERNEL);
210 
211 	if (p)
212 		memcpy(p, src, len);
213 	return p;
214 }
215 
216 /**
217  * unpack_u16_chunk - test and do bounds checking for a u16 size based chunk
218  * @e: serialized data read head (NOT NULL)
219  * @chunk: start address for chunk of data (NOT NULL)
220  *
221  * Returns: the size of chunk found with the read head at the end of the chunk.
222  */
unpack_u16_chunk(struct aa_ext * e,char ** chunk)223 static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk)
224 {
225 	size_t size = 0;
226 	void *pos = e->pos;
227 
228 	if (!inbounds(e, sizeof(u16)))
229 		goto fail;
230 	size = le16_to_cpu(get_unaligned((__le16 *) e->pos));
231 	e->pos += sizeof(__le16);
232 	if (!inbounds(e, size))
233 		goto fail;
234 	*chunk = e->pos;
235 	e->pos += size;
236 	return size;
237 
238 fail:
239 	e->pos = pos;
240 	return 0;
241 }
242 
243 /* unpack control byte */
unpack_X(struct aa_ext * e,enum aa_code code)244 static bool unpack_X(struct aa_ext *e, enum aa_code code)
245 {
246 	if (!inbounds(e, 1))
247 		return false;
248 	if (*(u8 *) e->pos != code)
249 		return false;
250 	e->pos++;
251 	return true;
252 }
253 
254 /**
255  * unpack_nameX - check is the next element is of type X with a name of @name
256  * @e: serialized data extent information  (NOT NULL)
257  * @code: type code
258  * @name: name to match to the serialized element.  (MAYBE NULL)
259  *
260  * check that the next serialized data element is of type X and has a tag
261  * name @name.  If @name is specified then there must be a matching
262  * name element in the stream.  If @name is NULL any name element will be
263  * skipped and only the typecode will be tested.
264  *
265  * Returns true on success (both type code and name tests match) and the read
266  * head is advanced past the headers
267  *
268  * Returns: false if either match fails, the read head does not move
269  */
unpack_nameX(struct aa_ext * e,enum aa_code code,const char * name)270 static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
271 {
272 	/*
273 	 * May need to reset pos if name or type doesn't match
274 	 */
275 	void *pos = e->pos;
276 	/*
277 	 * Check for presence of a tagname, and if present name size
278 	 * AA_NAME tag value is a u16.
279 	 */
280 	if (unpack_X(e, AA_NAME)) {
281 		char *tag = NULL;
282 		size_t size = unpack_u16_chunk(e, &tag);
283 		/* if a name is specified it must match. otherwise skip tag */
284 		if (name && (!size || tag[size-1] != '\0' || strcmp(name, tag)))
285 			goto fail;
286 	} else if (name) {
287 		/* if a name is specified and there is no name tag fail */
288 		goto fail;
289 	}
290 
291 	/* now check if type code matches */
292 	if (unpack_X(e, code))
293 		return true;
294 
295 fail:
296 	e->pos = pos;
297 	return false;
298 }
299 
unpack_u8(struct aa_ext * e,u8 * data,const char * name)300 static bool unpack_u8(struct aa_ext *e, u8 *data, const char *name)
301 {
302 	void *pos = e->pos;
303 
304 	if (unpack_nameX(e, AA_U8, name)) {
305 		if (!inbounds(e, sizeof(u8)))
306 			goto fail;
307 		if (data)
308 			*data = *((u8 *)e->pos);
309 		e->pos += sizeof(u8);
310 		return true;
311 	}
312 
313 fail:
314 	e->pos = pos;
315 	return false;
316 }
317 
unpack_u32(struct aa_ext * e,u32 * data,const char * name)318 static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
319 {
320 	void *pos = e->pos;
321 
322 	if (unpack_nameX(e, AA_U32, name)) {
323 		if (!inbounds(e, sizeof(u32)))
324 			goto fail;
325 		if (data)
326 			*data = le32_to_cpu(get_unaligned((__le32 *) e->pos));
327 		e->pos += sizeof(u32);
328 		return true;
329 	}
330 
331 fail:
332 	e->pos = pos;
333 	return false;
334 }
335 
unpack_u64(struct aa_ext * e,u64 * data,const char * name)336 static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name)
337 {
338 	void *pos = e->pos;
339 
340 	if (unpack_nameX(e, AA_U64, name)) {
341 		if (!inbounds(e, sizeof(u64)))
342 			goto fail;
343 		if (data)
344 			*data = le64_to_cpu(get_unaligned((__le64 *) e->pos));
345 		e->pos += sizeof(u64);
346 		return true;
347 	}
348 
349 fail:
350 	e->pos = pos;
351 	return false;
352 }
353 
unpack_array(struct aa_ext * e,const char * name)354 static size_t unpack_array(struct aa_ext *e, const char *name)
355 {
356 	void *pos = e->pos;
357 
358 	if (unpack_nameX(e, AA_ARRAY, name)) {
359 		int size;
360 		if (!inbounds(e, sizeof(u16)))
361 			goto fail;
362 		size = (int)le16_to_cpu(get_unaligned((__le16 *) e->pos));
363 		e->pos += sizeof(u16);
364 		return size;
365 	}
366 
367 fail:
368 	e->pos = pos;
369 	return 0;
370 }
371 
unpack_blob(struct aa_ext * e,char ** blob,const char * name)372 static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
373 {
374 	void *pos = e->pos;
375 
376 	if (unpack_nameX(e, AA_BLOB, name)) {
377 		u32 size;
378 		if (!inbounds(e, sizeof(u32)))
379 			goto fail;
380 		size = le32_to_cpu(get_unaligned((__le32 *) e->pos));
381 		e->pos += sizeof(u32);
382 		if (inbounds(e, (size_t) size)) {
383 			*blob = e->pos;
384 			e->pos += size;
385 			return size;
386 		}
387 	}
388 
389 fail:
390 	e->pos = pos;
391 	return 0;
392 }
393 
unpack_str(struct aa_ext * e,const char ** string,const char * name)394 static int unpack_str(struct aa_ext *e, const char **string, const char *name)
395 {
396 	char *src_str;
397 	size_t size = 0;
398 	void *pos = e->pos;
399 	*string = NULL;
400 	if (unpack_nameX(e, AA_STRING, name)) {
401 		size = unpack_u16_chunk(e, &src_str);
402 		if (size) {
403 			/* strings are null terminated, length is size - 1 */
404 			if (src_str[size - 1] != 0)
405 				goto fail;
406 			*string = src_str;
407 
408 			return size;
409 		}
410 	}
411 
412 fail:
413 	e->pos = pos;
414 	return 0;
415 }
416 
unpack_strdup(struct aa_ext * e,char ** string,const char * name)417 static int unpack_strdup(struct aa_ext *e, char **string, const char *name)
418 {
419 	const char *tmp;
420 	void *pos = e->pos;
421 	int res = unpack_str(e, &tmp, name);
422 	*string = NULL;
423 
424 	if (!res)
425 		return 0;
426 
427 	*string = kmemdup(tmp, res, GFP_KERNEL);
428 	if (!*string) {
429 		e->pos = pos;
430 		return 0;
431 	}
432 
433 	return res;
434 }
435 
436 
437 /**
438  * unpack_dfa - unpack a file rule dfa
439  * @e: serialized data extent information (NOT NULL)
440  *
441  * returns dfa or ERR_PTR or NULL if no dfa
442  */
unpack_dfa(struct aa_ext * e)443 static struct aa_dfa *unpack_dfa(struct aa_ext *e)
444 {
445 	char *blob = NULL;
446 	size_t size;
447 	struct aa_dfa *dfa = NULL;
448 
449 	size = unpack_blob(e, &blob, "aadfa");
450 	if (size) {
451 		/*
452 		 * The dfa is aligned with in the blob to 8 bytes
453 		 * from the beginning of the stream.
454 		 * alignment adjust needed by dfa unpack
455 		 */
456 		size_t sz = blob - (char *) e->start -
457 			((e->pos - e->start) & 7);
458 		size_t pad = ALIGN(sz, 8) - sz;
459 		int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) |
460 			TO_ACCEPT2_FLAG(YYTD_DATA32);
461 		if (aa_g_paranoid_load)
462 			flags |= DFA_FLAG_VERIFY_STATES;
463 		dfa = aa_dfa_unpack(blob + pad, size - pad, flags);
464 
465 		if (IS_ERR(dfa))
466 			return dfa;
467 
468 	}
469 
470 	return dfa;
471 }
472 
473 /**
474  * unpack_trans_table - unpack a profile transition table
475  * @e: serialized data extent information  (NOT NULL)
476  * @profile: profile to add the accept table to (NOT NULL)
477  *
478  * Returns: true if table successfully unpacked
479  */
unpack_trans_table(struct aa_ext * e,struct aa_profile * profile)480 static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile)
481 {
482 	void *saved_pos = e->pos;
483 
484 	/* exec table is optional */
485 	if (unpack_nameX(e, AA_STRUCT, "xtable")) {
486 		int i, size;
487 
488 		size = unpack_array(e, NULL);
489 		/* currently 4 exec bits and entries 0-3 are reserved iupcx */
490 		if (size > 16 - 4)
491 			goto fail;
492 		profile->file.trans.table = kcalloc(size, sizeof(char *),
493 						    GFP_KERNEL);
494 		if (!profile->file.trans.table)
495 			goto fail;
496 
497 		profile->file.trans.size = size;
498 		for (i = 0; i < size; i++) {
499 			char *str;
500 			int c, j, pos, size2 = unpack_strdup(e, &str, NULL);
501 			/* unpack_strdup verifies that the last character is
502 			 * null termination byte.
503 			 */
504 			if (!size2)
505 				goto fail;
506 			profile->file.trans.table[i] = str;
507 			/* verify that name doesn't start with space */
508 			if (isspace(*str))
509 				goto fail;
510 
511 			/* count internal #  of internal \0 */
512 			for (c = j = 0; j < size2 - 1; j++) {
513 				if (!str[j]) {
514 					pos = j;
515 					c++;
516 				}
517 			}
518 			if (*str == ':') {
519 				/* first character after : must be valid */
520 				if (!str[1])
521 					goto fail;
522 				/* beginning with : requires an embedded \0,
523 				 * verify that exactly 1 internal \0 exists
524 				 * trailing \0 already verified by unpack_strdup
525 				 *
526 				 * convert \0 back to : for label_parse
527 				 */
528 				if (c == 1)
529 					str[pos] = ':';
530 				else if (c > 1)
531 					goto fail;
532 			} else if (c)
533 				/* fail - all other cases with embedded \0 */
534 				goto fail;
535 		}
536 		if (!unpack_nameX(e, AA_ARRAYEND, NULL))
537 			goto fail;
538 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
539 			goto fail;
540 	}
541 	return true;
542 
543 fail:
544 	aa_free_domain_entries(&profile->file.trans);
545 	e->pos = saved_pos;
546 	return false;
547 }
548 
unpack_xattrs(struct aa_ext * e,struct aa_profile * profile)549 static bool unpack_xattrs(struct aa_ext *e, struct aa_profile *profile)
550 {
551 	void *pos = e->pos;
552 
553 	if (unpack_nameX(e, AA_STRUCT, "xattrs")) {
554 		int i, size;
555 
556 		size = unpack_array(e, NULL);
557 		profile->xattr_count = size;
558 		profile->xattrs = kcalloc(size, sizeof(char *), GFP_KERNEL);
559 		if (!profile->xattrs)
560 			goto fail;
561 		for (i = 0; i < size; i++) {
562 			if (!unpack_strdup(e, &profile->xattrs[i], NULL))
563 				goto fail;
564 		}
565 		if (!unpack_nameX(e, AA_ARRAYEND, NULL))
566 			goto fail;
567 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
568 			goto fail;
569 	}
570 
571 	return true;
572 
573 fail:
574 	e->pos = pos;
575 	return false;
576 }
577 
unpack_secmark(struct aa_ext * e,struct aa_profile * profile)578 static bool unpack_secmark(struct aa_ext *e, struct aa_profile *profile)
579 {
580 	void *pos = e->pos;
581 	int i, size;
582 
583 	if (unpack_nameX(e, AA_STRUCT, "secmark")) {
584 		size = unpack_array(e, NULL);
585 
586 		profile->secmark = kcalloc(size, sizeof(struct aa_secmark),
587 					   GFP_KERNEL);
588 		if (!profile->secmark)
589 			goto fail;
590 
591 		profile->secmark_count = size;
592 
593 		for (i = 0; i < size; i++) {
594 			if (!unpack_u8(e, &profile->secmark[i].audit, NULL))
595 				goto fail;
596 			if (!unpack_u8(e, &profile->secmark[i].deny, NULL))
597 				goto fail;
598 			if (!unpack_strdup(e, &profile->secmark[i].label, NULL))
599 				goto fail;
600 		}
601 		if (!unpack_nameX(e, AA_ARRAYEND, NULL))
602 			goto fail;
603 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
604 			goto fail;
605 	}
606 
607 	return true;
608 
609 fail:
610 	if (profile->secmark) {
611 		for (i = 0; i < size; i++)
612 			kfree(profile->secmark[i].label);
613 		kfree(profile->secmark);
614 		profile->secmark_count = 0;
615 		profile->secmark = NULL;
616 	}
617 
618 	e->pos = pos;
619 	return false;
620 }
621 
unpack_rlimits(struct aa_ext * e,struct aa_profile * profile)622 static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile)
623 {
624 	void *pos = e->pos;
625 
626 	/* rlimits are optional */
627 	if (unpack_nameX(e, AA_STRUCT, "rlimits")) {
628 		int i, size;
629 		u32 tmp = 0;
630 		if (!unpack_u32(e, &tmp, NULL))
631 			goto fail;
632 		profile->rlimits.mask = tmp;
633 
634 		size = unpack_array(e, NULL);
635 		if (size > RLIM_NLIMITS)
636 			goto fail;
637 		for (i = 0; i < size; i++) {
638 			u64 tmp2 = 0;
639 			int a = aa_map_resource(i);
640 			if (!unpack_u64(e, &tmp2, NULL))
641 				goto fail;
642 			profile->rlimits.limits[a].rlim_max = tmp2;
643 		}
644 		if (!unpack_nameX(e, AA_ARRAYEND, NULL))
645 			goto fail;
646 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
647 			goto fail;
648 	}
649 	return true;
650 
651 fail:
652 	e->pos = pos;
653 	return false;
654 }
655 
strhash(const void * data,u32 len,u32 seed)656 static u32 strhash(const void *data, u32 len, u32 seed)
657 {
658 	const char * const *key = data;
659 
660 	return jhash(*key, strlen(*key), seed);
661 }
662 
datacmp(struct rhashtable_compare_arg * arg,const void * obj)663 static int datacmp(struct rhashtable_compare_arg *arg, const void *obj)
664 {
665 	const struct aa_data *data = obj;
666 	const char * const *key = arg->key;
667 
668 	return strcmp(data->key, *key);
669 }
670 
671 /**
672  * unpack_profile - unpack a serialized profile
673  * @e: serialized data extent information (NOT NULL)
674  * @ns_name: pointer of newly allocated copy of %NULL in case of error
675  *
676  * NOTE: unpack profile sets audit struct if there is a failure
677  */
unpack_profile(struct aa_ext * e,char ** ns_name)678 static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
679 {
680 	struct aa_profile *profile = NULL;
681 	const char *tmpname, *tmpns = NULL, *name = NULL;
682 	const char *info = "failed to unpack profile";
683 	size_t ns_len;
684 	struct rhashtable_params params = { 0 };
685 	char *key = NULL;
686 	struct aa_data *data;
687 	int i, error = -EPROTO;
688 	kernel_cap_t tmpcap;
689 	u32 tmp;
690 
691 	*ns_name = NULL;
692 
693 	/* check that we have the right struct being passed */
694 	if (!unpack_nameX(e, AA_STRUCT, "profile"))
695 		goto fail;
696 	if (!unpack_str(e, &name, NULL))
697 		goto fail;
698 	if (*name == '\0')
699 		goto fail;
700 
701 	tmpname = aa_splitn_fqname(name, strlen(name), &tmpns, &ns_len);
702 	if (tmpns) {
703 		*ns_name = kstrndup(tmpns, ns_len, GFP_KERNEL);
704 		if (!*ns_name) {
705 			info = "out of memory";
706 			goto fail;
707 		}
708 		name = tmpname;
709 	}
710 
711 	profile = aa_alloc_profile(name, NULL, GFP_KERNEL);
712 	if (!profile)
713 		return ERR_PTR(-ENOMEM);
714 
715 	/* profile renaming is optional */
716 	(void) unpack_str(e, &profile->rename, "rename");
717 
718 	/* attachment string is optional */
719 	(void) unpack_str(e, &profile->attach, "attach");
720 
721 	/* xmatch is optional and may be NULL */
722 	profile->xmatch = unpack_dfa(e);
723 	if (IS_ERR(profile->xmatch)) {
724 		error = PTR_ERR(profile->xmatch);
725 		profile->xmatch = NULL;
726 		info = "bad xmatch";
727 		goto fail;
728 	}
729 	/* xmatch_len is not optional if xmatch is set */
730 	if (profile->xmatch) {
731 		if (!unpack_u32(e, &tmp, NULL)) {
732 			info = "missing xmatch len";
733 			goto fail;
734 		}
735 		profile->xmatch_len = tmp;
736 	}
737 
738 	/* disconnected attachment string is optional */
739 	(void) unpack_str(e, &profile->disconnected, "disconnected");
740 
741 	/* per profile debug flags (complain, audit) */
742 	if (!unpack_nameX(e, AA_STRUCT, "flags")) {
743 		info = "profile missing flags";
744 		goto fail;
745 	}
746 	info = "failed to unpack profile flags";
747 	if (!unpack_u32(e, &tmp, NULL))
748 		goto fail;
749 	if (tmp & PACKED_FLAG_HAT)
750 		profile->label.flags |= FLAG_HAT;
751 	if (tmp & PACKED_FLAG_DEBUG1)
752 		profile->label.flags |= FLAG_DEBUG1;
753 	if (tmp & PACKED_FLAG_DEBUG2)
754 		profile->label.flags |= FLAG_DEBUG2;
755 	if (!unpack_u32(e, &tmp, NULL))
756 		goto fail;
757 	if (tmp == PACKED_MODE_COMPLAIN || (e->version & FORCE_COMPLAIN_FLAG)) {
758 		profile->mode = APPARMOR_COMPLAIN;
759 	} else if (tmp == PACKED_MODE_ENFORCE) {
760 		profile->mode = APPARMOR_ENFORCE;
761 	} else if (tmp == PACKED_MODE_KILL) {
762 		profile->mode = APPARMOR_KILL;
763 	} else if (tmp == PACKED_MODE_UNCONFINED) {
764 		profile->mode = APPARMOR_UNCONFINED;
765 		profile->label.flags |= FLAG_UNCONFINED;
766 	} else {
767 		goto fail;
768 	}
769 	if (!unpack_u32(e, &tmp, NULL))
770 		goto fail;
771 	if (tmp)
772 		profile->audit = AUDIT_ALL;
773 
774 	if (!unpack_nameX(e, AA_STRUCTEND, NULL))
775 		goto fail;
776 
777 	/* path_flags is optional */
778 	if (unpack_u32(e, &profile->path_flags, "path_flags"))
779 		profile->path_flags |= profile->label.flags &
780 			PATH_MEDIATE_DELETED;
781 	else
782 		/* set a default value if path_flags field is not present */
783 		profile->path_flags = PATH_MEDIATE_DELETED;
784 
785 	info = "failed to unpack profile capabilities";
786 	if (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL))
787 		goto fail;
788 	if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL))
789 		goto fail;
790 	if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL))
791 		goto fail;
792 	if (!unpack_u32(e, &tmpcap.cap[0], NULL))
793 		goto fail;
794 
795 	info = "failed to unpack upper profile capabilities";
796 	if (unpack_nameX(e, AA_STRUCT, "caps64")) {
797 		/* optional upper half of 64 bit caps */
798 		if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL))
799 			goto fail;
800 		if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL))
801 			goto fail;
802 		if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL))
803 			goto fail;
804 		if (!unpack_u32(e, &(tmpcap.cap[1]), NULL))
805 			goto fail;
806 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
807 			goto fail;
808 	}
809 
810 	info = "failed to unpack extended profile capabilities";
811 	if (unpack_nameX(e, AA_STRUCT, "capsx")) {
812 		/* optional extended caps mediation mask */
813 		if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL))
814 			goto fail;
815 		if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL))
816 			goto fail;
817 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
818 			goto fail;
819 	}
820 
821 	if (!unpack_xattrs(e, profile)) {
822 		info = "failed to unpack profile xattrs";
823 		goto fail;
824 	}
825 
826 	if (!unpack_rlimits(e, profile)) {
827 		info = "failed to unpack profile rlimits";
828 		goto fail;
829 	}
830 
831 	if (!unpack_secmark(e, profile)) {
832 		info = "failed to unpack profile secmark rules";
833 		goto fail;
834 	}
835 
836 	if (unpack_nameX(e, AA_STRUCT, "policydb")) {
837 		/* generic policy dfa - optional and may be NULL */
838 		info = "failed to unpack policydb";
839 		profile->policy.dfa = unpack_dfa(e);
840 		if (IS_ERR(profile->policy.dfa)) {
841 			error = PTR_ERR(profile->policy.dfa);
842 			profile->policy.dfa = NULL;
843 			goto fail;
844 		} else if (!profile->policy.dfa) {
845 			error = -EPROTO;
846 			goto fail;
847 		}
848 		if (!unpack_u32(e, &profile->policy.start[0], "start"))
849 			/* default start state */
850 			profile->policy.start[0] = DFA_START;
851 		/* setup class index */
852 		for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) {
853 			profile->policy.start[i] =
854 				aa_dfa_next(profile->policy.dfa,
855 					    profile->policy.start[0],
856 					    i);
857 		}
858 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
859 			goto fail;
860 	} else
861 		profile->policy.dfa = aa_get_dfa(nulldfa);
862 
863 	/* get file rules */
864 	profile->file.dfa = unpack_dfa(e);
865 	if (IS_ERR(profile->file.dfa)) {
866 		error = PTR_ERR(profile->file.dfa);
867 		profile->file.dfa = NULL;
868 		info = "failed to unpack profile file rules";
869 		goto fail;
870 	} else if (profile->file.dfa) {
871 		if (!unpack_u32(e, &profile->file.start, "dfa_start"))
872 			/* default start state */
873 			profile->file.start = DFA_START;
874 	} else if (profile->policy.dfa &&
875 		   profile->policy.start[AA_CLASS_FILE]) {
876 		profile->file.dfa = aa_get_dfa(profile->policy.dfa);
877 		profile->file.start = profile->policy.start[AA_CLASS_FILE];
878 	} else
879 		profile->file.dfa = aa_get_dfa(nulldfa);
880 
881 	if (!unpack_trans_table(e, profile)) {
882 		info = "failed to unpack profile transition table";
883 		goto fail;
884 	}
885 
886 	if (unpack_nameX(e, AA_STRUCT, "data")) {
887 		info = "out of memory";
888 		profile->data = kzalloc(sizeof(*profile->data), GFP_KERNEL);
889 		if (!profile->data)
890 			goto fail;
891 
892 		params.nelem_hint = 3;
893 		params.key_len = sizeof(void *);
894 		params.key_offset = offsetof(struct aa_data, key);
895 		params.head_offset = offsetof(struct aa_data, head);
896 		params.hashfn = strhash;
897 		params.obj_cmpfn = datacmp;
898 
899 		if (rhashtable_init(profile->data, &params)) {
900 			info = "failed to init key, value hash table";
901 			goto fail;
902 		}
903 
904 		while (unpack_strdup(e, &key, NULL)) {
905 			data = kzalloc(sizeof(*data), GFP_KERNEL);
906 			if (!data) {
907 				kfree_sensitive(key);
908 				goto fail;
909 			}
910 
911 			data->key = key;
912 			data->size = unpack_blob(e, &data->data, NULL);
913 			data->data = kvmemdup(data->data, data->size);
914 			if (data->size && !data->data) {
915 				kfree_sensitive(data->key);
916 				kfree_sensitive(data);
917 				goto fail;
918 			}
919 
920 			rhashtable_insert_fast(profile->data, &data->head,
921 					       profile->data->p);
922 		}
923 
924 		if (!unpack_nameX(e, AA_STRUCTEND, NULL)) {
925 			info = "failed to unpack end of key, value data table";
926 			goto fail;
927 		}
928 	}
929 
930 	if (!unpack_nameX(e, AA_STRUCTEND, NULL)) {
931 		info = "failed to unpack end of profile";
932 		goto fail;
933 	}
934 
935 	return profile;
936 
937 fail:
938 	if (profile)
939 		name = NULL;
940 	else if (!name)
941 		name = "unknown";
942 	audit_iface(profile, NULL, name, info, e, error);
943 	aa_free_profile(profile);
944 
945 	return ERR_PTR(error);
946 }
947 
948 /**
949  * verify_header - unpack serialized stream header
950  * @e: serialized data read head (NOT NULL)
951  * @required: whether the header is required or optional
952  * @ns: Returns - namespace if one is specified else NULL (NOT NULL)
953  *
954  * Returns: error or 0 if header is good
955  */
verify_header(struct aa_ext * e,int required,const char ** ns)956 static int verify_header(struct aa_ext *e, int required, const char **ns)
957 {
958 	int error = -EPROTONOSUPPORT;
959 	const char *name = NULL;
960 	*ns = NULL;
961 
962 	/* get the interface version */
963 	if (!unpack_u32(e, &e->version, "version")) {
964 		if (required) {
965 			audit_iface(NULL, NULL, NULL, "invalid profile format",
966 				    e, error);
967 			return error;
968 		}
969 	}
970 
971 	/* Check that the interface version is currently supported.
972 	 * if not specified use previous version
973 	 * Mask off everything that is not kernel abi version
974 	 */
975 	if (VERSION_LT(e->version, v5) || VERSION_GT(e->version, v7)) {
976 		audit_iface(NULL, NULL, NULL, "unsupported interface version",
977 			    e, error);
978 		return error;
979 	}
980 
981 	/* read the namespace if present */
982 	if (unpack_str(e, &name, "namespace")) {
983 		if (*name == '\0') {
984 			audit_iface(NULL, NULL, NULL, "invalid namespace name",
985 				    e, error);
986 			return error;
987 		}
988 		if (*ns && strcmp(*ns, name)) {
989 			audit_iface(NULL, NULL, NULL, "invalid ns change", e,
990 				    error);
991 		} else if (!*ns) {
992 			*ns = kstrdup(name, GFP_KERNEL);
993 			if (!*ns)
994 				return -ENOMEM;
995 		}
996 	}
997 
998 	return 0;
999 }
1000 
verify_xindex(int xindex,int table_size)1001 static bool verify_xindex(int xindex, int table_size)
1002 {
1003 	int index, xtype;
1004 	xtype = xindex & AA_X_TYPE_MASK;
1005 	index = xindex & AA_X_INDEX_MASK;
1006 	if (xtype == AA_X_TABLE && index >= table_size)
1007 		return false;
1008 	return true;
1009 }
1010 
1011 /* verify dfa xindexes are in range of transition tables */
verify_dfa_xindex(struct aa_dfa * dfa,int table_size)1012 static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size)
1013 {
1014 	int i;
1015 	for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
1016 		if (!verify_xindex(dfa_user_xindex(dfa, i), table_size))
1017 			return false;
1018 		if (!verify_xindex(dfa_other_xindex(dfa, i), table_size))
1019 			return false;
1020 	}
1021 	return true;
1022 }
1023 
1024 /**
1025  * verify_profile - Do post unpack analysis to verify profile consistency
1026  * @profile: profile to verify (NOT NULL)
1027  *
1028  * Returns: 0 if passes verification else error
1029  */
verify_profile(struct aa_profile * profile)1030 static int verify_profile(struct aa_profile *profile)
1031 {
1032 	if (profile->file.dfa &&
1033 	    !verify_dfa_xindex(profile->file.dfa,
1034 			       profile->file.trans.size)) {
1035 		audit_iface(profile, NULL, NULL, "Invalid named transition",
1036 			    NULL, -EPROTO);
1037 		return -EPROTO;
1038 	}
1039 
1040 	return 0;
1041 }
1042 
aa_load_ent_free(struct aa_load_ent * ent)1043 void aa_load_ent_free(struct aa_load_ent *ent)
1044 {
1045 	if (ent) {
1046 		aa_put_profile(ent->rename);
1047 		aa_put_profile(ent->old);
1048 		aa_put_profile(ent->new);
1049 		kfree(ent->ns_name);
1050 		kfree_sensitive(ent);
1051 	}
1052 }
1053 
aa_load_ent_alloc(void)1054 struct aa_load_ent *aa_load_ent_alloc(void)
1055 {
1056 	struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL);
1057 	if (ent)
1058 		INIT_LIST_HEAD(&ent->list);
1059 	return ent;
1060 }
1061 
deflate_compress(const char * src,size_t slen,char ** dst,size_t * dlen)1062 static int deflate_compress(const char *src, size_t slen, char **dst,
1063 			    size_t *dlen)
1064 {
1065 #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY
1066 	int error;
1067 	struct z_stream_s strm;
1068 	void *stgbuf, *dstbuf;
1069 	size_t stglen = deflateBound(slen);
1070 
1071 	memset(&strm, 0, sizeof(strm));
1072 
1073 	if (stglen < slen)
1074 		return -EFBIG;
1075 
1076 	strm.workspace = kvzalloc(zlib_deflate_workspacesize(MAX_WBITS,
1077 							     MAX_MEM_LEVEL),
1078 				  GFP_KERNEL);
1079 	if (!strm.workspace)
1080 		return -ENOMEM;
1081 
1082 	error = zlib_deflateInit(&strm, aa_g_rawdata_compression_level);
1083 	if (error != Z_OK) {
1084 		error = -ENOMEM;
1085 		goto fail_deflate_init;
1086 	}
1087 
1088 	stgbuf = kvzalloc(stglen, GFP_KERNEL);
1089 	if (!stgbuf) {
1090 		error = -ENOMEM;
1091 		goto fail_stg_alloc;
1092 	}
1093 
1094 	strm.next_in = src;
1095 	strm.avail_in = slen;
1096 	strm.next_out = stgbuf;
1097 	strm.avail_out = stglen;
1098 
1099 	error = zlib_deflate(&strm, Z_FINISH);
1100 	if (error != Z_STREAM_END) {
1101 		error = -EINVAL;
1102 		goto fail_deflate;
1103 	}
1104 	error = 0;
1105 
1106 	if (is_vmalloc_addr(stgbuf)) {
1107 		dstbuf = kvzalloc(strm.total_out, GFP_KERNEL);
1108 		if (dstbuf) {
1109 			memcpy(dstbuf, stgbuf, strm.total_out);
1110 			kvfree(stgbuf);
1111 		}
1112 	} else
1113 		/*
1114 		 * If the staging buffer was kmalloc'd, then using krealloc is
1115 		 * probably going to be faster. The destination buffer will
1116 		 * always be smaller, so it's just shrunk, avoiding a memcpy
1117 		 */
1118 		dstbuf = krealloc(stgbuf, strm.total_out, GFP_KERNEL);
1119 
1120 	if (!dstbuf) {
1121 		error = -ENOMEM;
1122 		goto fail_deflate;
1123 	}
1124 
1125 	*dst = dstbuf;
1126 	*dlen = strm.total_out;
1127 
1128 fail_stg_alloc:
1129 	zlib_deflateEnd(&strm);
1130 fail_deflate_init:
1131 	kvfree(strm.workspace);
1132 	return error;
1133 
1134 fail_deflate:
1135 	kvfree(stgbuf);
1136 	goto fail_stg_alloc;
1137 #else
1138 	*dlen = slen;
1139 	return 0;
1140 #endif
1141 }
1142 
compress_loaddata(struct aa_loaddata * data)1143 static int compress_loaddata(struct aa_loaddata *data)
1144 {
1145 
1146 	AA_BUG(data->compressed_size > 0);
1147 
1148 	/*
1149 	 * Shortcut the no compression case, else we increase the amount of
1150 	 * storage required by a small amount
1151 	 */
1152 	if (aa_g_rawdata_compression_level != 0) {
1153 		void *udata = data->data;
1154 		int error = deflate_compress(udata, data->size, &data->data,
1155 					     &data->compressed_size);
1156 		if (error)
1157 			return error;
1158 
1159 		if (udata != data->data)
1160 			kvfree(udata);
1161 	} else
1162 		data->compressed_size = data->size;
1163 
1164 	return 0;
1165 }
1166 
1167 /**
1168  * aa_unpack - unpack packed binary profile(s) data loaded from user space
1169  * @udata: user data copied to kmem  (NOT NULL)
1170  * @lh: list to place unpacked profiles in a aa_repl_ws
1171  * @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
1172  *
1173  * Unpack user data and return refcounted allocated profile(s) stored in
1174  * @lh in order of discovery, with the list chain stored in base.list
1175  * or error
1176  *
1177  * Returns: profile(s) on @lh else error pointer if fails to unpack
1178  */
aa_unpack(struct aa_loaddata * udata,struct list_head * lh,const char ** ns)1179 int aa_unpack(struct aa_loaddata *udata, struct list_head *lh,
1180 	      const char **ns)
1181 {
1182 	struct aa_load_ent *tmp, *ent;
1183 	struct aa_profile *profile = NULL;
1184 	int error;
1185 	struct aa_ext e = {
1186 		.start = udata->data,
1187 		.end = udata->data + udata->size,
1188 		.pos = udata->data,
1189 	};
1190 
1191 	*ns = NULL;
1192 	while (e.pos < e.end) {
1193 		char *ns_name = NULL;
1194 		void *start;
1195 		error = verify_header(&e, e.pos == e.start, ns);
1196 		if (error)
1197 			goto fail;
1198 
1199 		start = e.pos;
1200 		profile = unpack_profile(&e, &ns_name);
1201 		if (IS_ERR(profile)) {
1202 			error = PTR_ERR(profile);
1203 			goto fail;
1204 		}
1205 
1206 		error = verify_profile(profile);
1207 		if (error)
1208 			goto fail_profile;
1209 
1210 		if (aa_g_hash_policy)
1211 			error = aa_calc_profile_hash(profile, e.version, start,
1212 						     e.pos - start);
1213 		if (error)
1214 			goto fail_profile;
1215 
1216 		ent = aa_load_ent_alloc();
1217 		if (!ent) {
1218 			error = -ENOMEM;
1219 			goto fail_profile;
1220 		}
1221 
1222 		ent->new = profile;
1223 		ent->ns_name = ns_name;
1224 		list_add_tail(&ent->list, lh);
1225 	}
1226 	udata->abi = e.version & K_ABI_MASK;
1227 	if (aa_g_hash_policy) {
1228 		udata->hash = aa_calc_hash(udata->data, udata->size);
1229 		if (IS_ERR(udata->hash)) {
1230 			error = PTR_ERR(udata->hash);
1231 			udata->hash = NULL;
1232 			goto fail;
1233 		}
1234 	}
1235 
1236 	if (aa_g_export_binary) {
1237 		error = compress_loaddata(udata);
1238 		if (error)
1239 			goto fail;
1240 	}
1241 	return 0;
1242 
1243 fail_profile:
1244 	aa_put_profile(profile);
1245 
1246 fail:
1247 	list_for_each_entry_safe(ent, tmp, lh, list) {
1248 		list_del_init(&ent->list);
1249 		aa_load_ent_free(ent);
1250 	}
1251 
1252 	return error;
1253 }
1254 
1255 #ifdef CONFIG_SECURITY_APPARMOR_KUNIT_TEST
1256 #include "policy_unpack_test.c"
1257 #endif /* CONFIG_SECURITY_APPARMOR_KUNIT_TEST */
1258