1 /*
2  * AppArmor security module
3  *
4  * This file contains AppArmor functions for unpacking policy loaded from
5  * userspace.
6  *
7  * Copyright (C) 1998-2008 Novell/SUSE
8  * Copyright 2009-2010 Canonical Ltd.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation, version 2 of the
13  * License.
14  *
15  * AppArmor uses a serialized binary format for loading policy. To find
16  * policy format documentation see Documentation/admin-guide/LSM/apparmor.rst
17  * All policy is validated before it is used.
18  */
19 
20 #include <asm/unaligned.h>
21 #include <linux/ctype.h>
22 #include <linux/errno.h>
23 
24 #include "include/apparmor.h"
25 #include "include/audit.h"
26 #include "include/cred.h"
27 #include "include/crypto.h"
28 #include "include/match.h"
29 #include "include/path.h"
30 #include "include/policy.h"
31 #include "include/policy_unpack.h"
32 
33 #define K_ABI_MASK 0x3ff
34 #define FORCE_COMPLAIN_FLAG 0x800
35 #define VERSION_LT(X, Y) (((X) & K_ABI_MASK) < ((Y) & K_ABI_MASK))
36 #define VERSION_GT(X, Y) (((X) & K_ABI_MASK) > ((Y) & K_ABI_MASK))
37 
38 #define v5	5	/* base version */
39 #define v6	6	/* per entry policydb mediation check */
40 #define v7	7
41 #define v8	8	/* full network masking */
42 
43 /*
44  * The AppArmor interface treats data as a type byte followed by the
45  * actual data.  The interface has the notion of a a named entry
46  * which has a name (AA_NAME typecode followed by name string) followed by
47  * the entries typecode and data.  Named types allow for optional
48  * elements and extensions to be added and tested for without breaking
49  * backwards compatibility.
50  */
51 
52 enum aa_code {
53 	AA_U8,
54 	AA_U16,
55 	AA_U32,
56 	AA_U64,
57 	AA_NAME,		/* same as string except it is items name */
58 	AA_STRING,
59 	AA_BLOB,
60 	AA_STRUCT,
61 	AA_STRUCTEND,
62 	AA_LIST,
63 	AA_LISTEND,
64 	AA_ARRAY,
65 	AA_ARRAYEND,
66 };
67 
68 /*
69  * aa_ext is the read of the buffer containing the serialized profile.  The
70  * data is copied into a kernel buffer in apparmorfs and then handed off to
71  * the unpack routines.
72  */
73 struct aa_ext {
74 	void *start;
75 	void *end;
76 	void *pos;		/* pointer to current position in the buffer */
77 	u32 version;
78 };
79 
80 /* audit callback for unpack fields */
audit_cb(struct audit_buffer * ab,void * va)81 static void audit_cb(struct audit_buffer *ab, void *va)
82 {
83 	struct common_audit_data *sa = va;
84 
85 	if (aad(sa)->iface.ns) {
86 		audit_log_format(ab, " ns=");
87 		audit_log_untrustedstring(ab, aad(sa)->iface.ns);
88 	}
89 	if (aad(sa)->name) {
90 		audit_log_format(ab, " name=");
91 		audit_log_untrustedstring(ab, aad(sa)->name);
92 	}
93 	if (aad(sa)->iface.pos)
94 		audit_log_format(ab, " offset=%ld", aad(sa)->iface.pos);
95 }
96 
97 /**
98  * audit_iface - do audit message for policy unpacking/load/replace/remove
99  * @new: profile if it has been allocated (MAYBE NULL)
100  * @ns_name: name of the ns the profile is to be loaded to (MAY BE NULL)
101  * @name: name of the profile being manipulated (MAYBE NULL)
102  * @info: any extra info about the failure (MAYBE NULL)
103  * @e: buffer position info
104  * @error: error code
105  *
106  * Returns: %0 or error
107  */
audit_iface(struct aa_profile * new,const char * ns_name,const char * name,const char * info,struct aa_ext * e,int error)108 static int audit_iface(struct aa_profile *new, const char *ns_name,
109 		       const char *name, const char *info, struct aa_ext *e,
110 		       int error)
111 {
112 	struct aa_profile *profile = labels_profile(aa_current_raw_label());
113 	DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, NULL);
114 	if (e)
115 		aad(&sa)->iface.pos = e->pos - e->start;
116 	aad(&sa)->iface.ns = ns_name;
117 	if (new)
118 		aad(&sa)->name = new->base.hname;
119 	else
120 		aad(&sa)->name = name;
121 	aad(&sa)->info = info;
122 	aad(&sa)->error = error;
123 
124 	return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb);
125 }
126 
__aa_loaddata_update(struct aa_loaddata * data,long revision)127 void __aa_loaddata_update(struct aa_loaddata *data, long revision)
128 {
129 	AA_BUG(!data);
130 	AA_BUG(!data->ns);
131 	AA_BUG(!data->dents[AAFS_LOADDATA_REVISION]);
132 	AA_BUG(!mutex_is_locked(&data->ns->lock));
133 	AA_BUG(data->revision > revision);
134 
135 	data->revision = revision;
136 	d_inode(data->dents[AAFS_LOADDATA_DIR])->i_mtime =
137 		current_time(d_inode(data->dents[AAFS_LOADDATA_DIR]));
138 	d_inode(data->dents[AAFS_LOADDATA_REVISION])->i_mtime =
139 		current_time(d_inode(data->dents[AAFS_LOADDATA_REVISION]));
140 }
141 
aa_rawdata_eq(struct aa_loaddata * l,struct aa_loaddata * r)142 bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r)
143 {
144 	if (l->size != r->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->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 	kzfree(d->hash);
168 	kzfree(d->name);
169 	kvfree(d->data);
170 	kzfree(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  * aa_u16_chunck - 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 
227 	if (!inbounds(e, sizeof(u16)))
228 		return 0;
229 	size = le16_to_cpu(get_unaligned((__le16 *) e->pos));
230 	e->pos += sizeof(__le16);
231 	if (!inbounds(e, size))
232 		return 0;
233 	*chunk = e->pos;
234 	e->pos += size;
235 	return size;
236 }
237 
238 /* unpack control byte */
unpack_X(struct aa_ext * e,enum aa_code code)239 static bool unpack_X(struct aa_ext *e, enum aa_code code)
240 {
241 	if (!inbounds(e, 1))
242 		return 0;
243 	if (*(u8 *) e->pos != code)
244 		return 0;
245 	e->pos++;
246 	return 1;
247 }
248 
249 /**
250  * unpack_nameX - check is the next element is of type X with a name of @name
251  * @e: serialized data extent information  (NOT NULL)
252  * @code: type code
253  * @name: name to match to the serialized element.  (MAYBE NULL)
254  *
255  * check that the next serialized data element is of type X and has a tag
256  * name @name.  If @name is specified then there must be a matching
257  * name element in the stream.  If @name is NULL any name element will be
258  * skipped and only the typecode will be tested.
259  *
260  * Returns 1 on success (both type code and name tests match) and the read
261  * head is advanced past the headers
262  *
263  * Returns: 0 if either match fails, the read head does not move
264  */
unpack_nameX(struct aa_ext * e,enum aa_code code,const char * name)265 static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
266 {
267 	/*
268 	 * May need to reset pos if name or type doesn't match
269 	 */
270 	void *pos = e->pos;
271 	/*
272 	 * Check for presence of a tagname, and if present name size
273 	 * AA_NAME tag value is a u16.
274 	 */
275 	if (unpack_X(e, AA_NAME)) {
276 		char *tag = NULL;
277 		size_t size = unpack_u16_chunk(e, &tag);
278 		/* if a name is specified it must match. otherwise skip tag */
279 		if (name && (!size || strcmp(name, tag)))
280 			goto fail;
281 	} else if (name) {
282 		/* if a name is specified and there is no name tag fail */
283 		goto fail;
284 	}
285 
286 	/* now check if type code matches */
287 	if (unpack_X(e, code))
288 		return 1;
289 
290 fail:
291 	e->pos = pos;
292 	return 0;
293 }
294 
unpack_u32(struct aa_ext * e,u32 * data,const char * name)295 static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
296 {
297 	if (unpack_nameX(e, AA_U32, name)) {
298 		if (!inbounds(e, sizeof(u32)))
299 			return 0;
300 		if (data)
301 			*data = le32_to_cpu(get_unaligned((__le32 *) e->pos));
302 		e->pos += sizeof(u32);
303 		return 1;
304 	}
305 	return 0;
306 }
307 
unpack_u64(struct aa_ext * e,u64 * data,const char * name)308 static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name)
309 {
310 	if (unpack_nameX(e, AA_U64, name)) {
311 		if (!inbounds(e, sizeof(u64)))
312 			return 0;
313 		if (data)
314 			*data = le64_to_cpu(get_unaligned((__le64 *) e->pos));
315 		e->pos += sizeof(u64);
316 		return 1;
317 	}
318 	return 0;
319 }
320 
unpack_array(struct aa_ext * e,const char * name)321 static size_t unpack_array(struct aa_ext *e, const char *name)
322 {
323 	if (unpack_nameX(e, AA_ARRAY, name)) {
324 		int size;
325 		if (!inbounds(e, sizeof(u16)))
326 			return 0;
327 		size = (int)le16_to_cpu(get_unaligned((__le16 *) e->pos));
328 		e->pos += sizeof(u16);
329 		return size;
330 	}
331 	return 0;
332 }
333 
unpack_blob(struct aa_ext * e,char ** blob,const char * name)334 static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
335 {
336 	if (unpack_nameX(e, AA_BLOB, name)) {
337 		u32 size;
338 		if (!inbounds(e, sizeof(u32)))
339 			return 0;
340 		size = le32_to_cpu(get_unaligned((__le32 *) e->pos));
341 		e->pos += sizeof(u32);
342 		if (inbounds(e, (size_t) size)) {
343 			*blob = e->pos;
344 			e->pos += size;
345 			return size;
346 		}
347 	}
348 	return 0;
349 }
350 
unpack_str(struct aa_ext * e,const char ** string,const char * name)351 static int unpack_str(struct aa_ext *e, const char **string, const char *name)
352 {
353 	char *src_str;
354 	size_t size = 0;
355 	void *pos = e->pos;
356 	*string = NULL;
357 	if (unpack_nameX(e, AA_STRING, name)) {
358 		size = unpack_u16_chunk(e, &src_str);
359 		if (size) {
360 			/* strings are null terminated, length is size - 1 */
361 			if (src_str[size - 1] != 0)
362 				goto fail;
363 			*string = src_str;
364 		}
365 	}
366 	return size;
367 
368 fail:
369 	e->pos = pos;
370 	return 0;
371 }
372 
unpack_strdup(struct aa_ext * e,char ** string,const char * name)373 static int unpack_strdup(struct aa_ext *e, char **string, const char *name)
374 {
375 	const char *tmp;
376 	void *pos = e->pos;
377 	int res = unpack_str(e, &tmp, name);
378 	*string = NULL;
379 
380 	if (!res)
381 		return 0;
382 
383 	*string = kmemdup(tmp, res, GFP_KERNEL);
384 	if (!*string) {
385 		e->pos = pos;
386 		return 0;
387 	}
388 
389 	return res;
390 }
391 
392 
393 /**
394  * unpack_dfa - unpack a file rule dfa
395  * @e: serialized data extent information (NOT NULL)
396  *
397  * returns dfa or ERR_PTR or NULL if no dfa
398  */
unpack_dfa(struct aa_ext * e)399 static struct aa_dfa *unpack_dfa(struct aa_ext *e)
400 {
401 	char *blob = NULL;
402 	size_t size;
403 	struct aa_dfa *dfa = NULL;
404 
405 	size = unpack_blob(e, &blob, "aadfa");
406 	if (size) {
407 		/*
408 		 * The dfa is aligned with in the blob to 8 bytes
409 		 * from the beginning of the stream.
410 		 * alignment adjust needed by dfa unpack
411 		 */
412 		size_t sz = blob - (char *) e->start -
413 			((e->pos - e->start) & 7);
414 		size_t pad = ALIGN(sz, 8) - sz;
415 		int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) |
416 			TO_ACCEPT2_FLAG(YYTD_DATA32) | DFA_FLAG_VERIFY_STATES;
417 		dfa = aa_dfa_unpack(blob + pad, size - pad, flags);
418 
419 		if (IS_ERR(dfa))
420 			return dfa;
421 
422 	}
423 
424 	return dfa;
425 }
426 
427 /**
428  * unpack_trans_table - unpack a profile transition table
429  * @e: serialized data extent information  (NOT NULL)
430  * @profile: profile to add the accept table to (NOT NULL)
431  *
432  * Returns: 1 if table successfully unpacked
433  */
unpack_trans_table(struct aa_ext * e,struct aa_profile * profile)434 static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile)
435 {
436 	void *saved_pos = e->pos;
437 
438 	/* exec table is optional */
439 	if (unpack_nameX(e, AA_STRUCT, "xtable")) {
440 		int i, size;
441 
442 		size = unpack_array(e, NULL);
443 		/* currently 4 exec bits and entries 0-3 are reserved iupcx */
444 		if (size > 16 - 4)
445 			goto fail;
446 		profile->file.trans.table = kcalloc(size, sizeof(char *),
447 						    GFP_KERNEL);
448 		if (!profile->file.trans.table)
449 			goto fail;
450 
451 		profile->file.trans.size = size;
452 		for (i = 0; i < size; i++) {
453 			char *str;
454 			int c, j, pos, size2 = unpack_strdup(e, &str, NULL);
455 			/* unpack_strdup verifies that the last character is
456 			 * null termination byte.
457 			 */
458 			if (!size2)
459 				goto fail;
460 			profile->file.trans.table[i] = str;
461 			/* verify that name doesn't start with space */
462 			if (isspace(*str))
463 				goto fail;
464 
465 			/* count internal #  of internal \0 */
466 			for (c = j = 0; j < size2 - 1; j++) {
467 				if (!str[j]) {
468 					pos = j;
469 					c++;
470 				}
471 			}
472 			if (*str == ':') {
473 				/* first character after : must be valid */
474 				if (!str[1])
475 					goto fail;
476 				/* beginning with : requires an embedded \0,
477 				 * verify that exactly 1 internal \0 exists
478 				 * trailing \0 already verified by unpack_strdup
479 				 *
480 				 * convert \0 back to : for label_parse
481 				 */
482 				if (c == 1)
483 					str[pos] = ':';
484 				else if (c > 1)
485 					goto fail;
486 			} else if (c)
487 				/* fail - all other cases with embedded \0 */
488 				goto fail;
489 		}
490 		if (!unpack_nameX(e, AA_ARRAYEND, NULL))
491 			goto fail;
492 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
493 			goto fail;
494 	}
495 	return 1;
496 
497 fail:
498 	aa_free_domain_entries(&profile->file.trans);
499 	e->pos = saved_pos;
500 	return 0;
501 }
502 
unpack_xattrs(struct aa_ext * e,struct aa_profile * profile)503 static bool unpack_xattrs(struct aa_ext *e, struct aa_profile *profile)
504 {
505 	void *pos = e->pos;
506 
507 	if (unpack_nameX(e, AA_STRUCT, "xattrs")) {
508 		int i, size;
509 
510 		size = unpack_array(e, NULL);
511 		profile->xattr_count = size;
512 		profile->xattrs = kcalloc(size, sizeof(char *), GFP_KERNEL);
513 		if (!profile->xattrs)
514 			goto fail;
515 		for (i = 0; i < size; i++) {
516 			if (!unpack_strdup(e, &profile->xattrs[i], NULL))
517 				goto fail;
518 		}
519 		if (!unpack_nameX(e, AA_ARRAYEND, NULL))
520 			goto fail;
521 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
522 			goto fail;
523 	}
524 
525 	return 1;
526 
527 fail:
528 	e->pos = pos;
529 	return 0;
530 }
531 
unpack_rlimits(struct aa_ext * e,struct aa_profile * profile)532 static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile)
533 {
534 	void *pos = e->pos;
535 
536 	/* rlimits are optional */
537 	if (unpack_nameX(e, AA_STRUCT, "rlimits")) {
538 		int i, size;
539 		u32 tmp = 0;
540 		if (!unpack_u32(e, &tmp, NULL))
541 			goto fail;
542 		profile->rlimits.mask = tmp;
543 
544 		size = unpack_array(e, NULL);
545 		if (size > RLIM_NLIMITS)
546 			goto fail;
547 		for (i = 0; i < size; i++) {
548 			u64 tmp2 = 0;
549 			int a = aa_map_resource(i);
550 			if (!unpack_u64(e, &tmp2, NULL))
551 				goto fail;
552 			profile->rlimits.limits[a].rlim_max = tmp2;
553 		}
554 		if (!unpack_nameX(e, AA_ARRAYEND, NULL))
555 			goto fail;
556 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
557 			goto fail;
558 	}
559 	return 1;
560 
561 fail:
562 	e->pos = pos;
563 	return 0;
564 }
565 
strhash(const void * data,u32 len,u32 seed)566 static u32 strhash(const void *data, u32 len, u32 seed)
567 {
568 	const char * const *key = data;
569 
570 	return jhash(*key, strlen(*key), seed);
571 }
572 
datacmp(struct rhashtable_compare_arg * arg,const void * obj)573 static int datacmp(struct rhashtable_compare_arg *arg, const void *obj)
574 {
575 	const struct aa_data *data = obj;
576 	const char * const *key = arg->key;
577 
578 	return strcmp(data->key, *key);
579 }
580 
581 /**
582  * unpack_profile - unpack a serialized profile
583  * @e: serialized data extent information (NOT NULL)
584  *
585  * NOTE: unpack profile sets audit struct if there is a failure
586  */
unpack_profile(struct aa_ext * e,char ** ns_name)587 static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
588 {
589 	struct aa_profile *profile = NULL;
590 	const char *tmpname, *tmpns = NULL, *name = NULL;
591 	const char *info = "failed to unpack profile";
592 	size_t ns_len;
593 	struct rhashtable_params params = { 0 };
594 	char *key = NULL;
595 	struct aa_data *data;
596 	int i, error = -EPROTO;
597 	kernel_cap_t tmpcap;
598 	u32 tmp;
599 
600 	*ns_name = NULL;
601 
602 	/* check that we have the right struct being passed */
603 	if (!unpack_nameX(e, AA_STRUCT, "profile"))
604 		goto fail;
605 	if (!unpack_str(e, &name, NULL))
606 		goto fail;
607 	if (*name == '\0')
608 		goto fail;
609 
610 	tmpname = aa_splitn_fqname(name, strlen(name), &tmpns, &ns_len);
611 	if (tmpns) {
612 		*ns_name = kstrndup(tmpns, ns_len, GFP_KERNEL);
613 		if (!*ns_name) {
614 			info = "out of memory";
615 			goto fail;
616 		}
617 		name = tmpname;
618 	}
619 
620 	profile = aa_alloc_profile(name, NULL, GFP_KERNEL);
621 	if (!profile)
622 		return ERR_PTR(-ENOMEM);
623 
624 	/* profile renaming is optional */
625 	(void) unpack_str(e, &profile->rename, "rename");
626 
627 	/* attachment string is optional */
628 	(void) unpack_str(e, &profile->attach, "attach");
629 
630 	/* xmatch is optional and may be NULL */
631 	profile->xmatch = unpack_dfa(e);
632 	if (IS_ERR(profile->xmatch)) {
633 		error = PTR_ERR(profile->xmatch);
634 		profile->xmatch = NULL;
635 		info = "bad xmatch";
636 		goto fail;
637 	}
638 	/* xmatch_len is not optional if xmatch is set */
639 	if (profile->xmatch) {
640 		if (!unpack_u32(e, &tmp, NULL)) {
641 			info = "missing xmatch len";
642 			goto fail;
643 		}
644 		profile->xmatch_len = tmp;
645 	}
646 
647 	/* disconnected attachment string is optional */
648 	(void) unpack_str(e, &profile->disconnected, "disconnected");
649 
650 	/* per profile debug flags (complain, audit) */
651 	if (!unpack_nameX(e, AA_STRUCT, "flags")) {
652 		info = "profile missing flags";
653 		goto fail;
654 	}
655 	info = "failed to unpack profile flags";
656 	if (!unpack_u32(e, &tmp, NULL))
657 		goto fail;
658 	if (tmp & PACKED_FLAG_HAT)
659 		profile->label.flags |= FLAG_HAT;
660 	if (!unpack_u32(e, &tmp, NULL))
661 		goto fail;
662 	if (tmp == PACKED_MODE_COMPLAIN || (e->version & FORCE_COMPLAIN_FLAG))
663 		profile->mode = APPARMOR_COMPLAIN;
664 	else if (tmp == PACKED_MODE_KILL)
665 		profile->mode = APPARMOR_KILL;
666 	else if (tmp == PACKED_MODE_UNCONFINED)
667 		profile->mode = APPARMOR_UNCONFINED;
668 	if (!unpack_u32(e, &tmp, NULL))
669 		goto fail;
670 	if (tmp)
671 		profile->audit = AUDIT_ALL;
672 
673 	if (!unpack_nameX(e, AA_STRUCTEND, NULL))
674 		goto fail;
675 
676 	/* path_flags is optional */
677 	if (unpack_u32(e, &profile->path_flags, "path_flags"))
678 		profile->path_flags |= profile->label.flags &
679 			PATH_MEDIATE_DELETED;
680 	else
681 		/* set a default value if path_flags field is not present */
682 		profile->path_flags = PATH_MEDIATE_DELETED;
683 
684 	info = "failed to unpack profile capabilities";
685 	if (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL))
686 		goto fail;
687 	if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL))
688 		goto fail;
689 	if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL))
690 		goto fail;
691 	if (!unpack_u32(e, &tmpcap.cap[0], NULL))
692 		goto fail;
693 
694 	info = "failed to unpack upper profile capabilities";
695 	if (unpack_nameX(e, AA_STRUCT, "caps64")) {
696 		/* optional upper half of 64 bit caps */
697 		if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL))
698 			goto fail;
699 		if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL))
700 			goto fail;
701 		if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL))
702 			goto fail;
703 		if (!unpack_u32(e, &(tmpcap.cap[1]), NULL))
704 			goto fail;
705 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
706 			goto fail;
707 	}
708 
709 	info = "failed to unpack extended profile capabilities";
710 	if (unpack_nameX(e, AA_STRUCT, "capsx")) {
711 		/* optional extended caps mediation mask */
712 		if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL))
713 			goto fail;
714 		if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL))
715 			goto fail;
716 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
717 			goto fail;
718 	}
719 
720 	if (!unpack_xattrs(e, profile)) {
721 		info = "failed to unpack profile xattrs";
722 		goto fail;
723 	}
724 
725 	if (!unpack_rlimits(e, profile)) {
726 		info = "failed to unpack profile rlimits";
727 		goto fail;
728 	}
729 
730 	if (unpack_nameX(e, AA_STRUCT, "policydb")) {
731 		/* generic policy dfa - optional and may be NULL */
732 		info = "failed to unpack policydb";
733 		profile->policy.dfa = unpack_dfa(e);
734 		if (IS_ERR(profile->policy.dfa)) {
735 			error = PTR_ERR(profile->policy.dfa);
736 			profile->policy.dfa = NULL;
737 			goto fail;
738 		} else if (!profile->policy.dfa) {
739 			error = -EPROTO;
740 			goto fail;
741 		}
742 		if (!unpack_u32(e, &profile->policy.start[0], "start"))
743 			/* default start state */
744 			profile->policy.start[0] = DFA_START;
745 		/* setup class index */
746 		for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) {
747 			profile->policy.start[i] =
748 				aa_dfa_next(profile->policy.dfa,
749 					    profile->policy.start[0],
750 					    i);
751 		}
752 		if (!unpack_nameX(e, AA_STRUCTEND, NULL))
753 			goto fail;
754 	} else
755 		profile->policy.dfa = aa_get_dfa(nulldfa);
756 
757 	/* get file rules */
758 	profile->file.dfa = unpack_dfa(e);
759 	if (IS_ERR(profile->file.dfa)) {
760 		error = PTR_ERR(profile->file.dfa);
761 		profile->file.dfa = NULL;
762 		info = "failed to unpack profile file rules";
763 		goto fail;
764 	} else if (profile->file.dfa) {
765 		if (!unpack_u32(e, &profile->file.start, "dfa_start"))
766 			/* default start state */
767 			profile->file.start = DFA_START;
768 	} else if (profile->policy.dfa &&
769 		   profile->policy.start[AA_CLASS_FILE]) {
770 		profile->file.dfa = aa_get_dfa(profile->policy.dfa);
771 		profile->file.start = profile->policy.start[AA_CLASS_FILE];
772 	} else
773 		profile->file.dfa = aa_get_dfa(nulldfa);
774 
775 	if (!unpack_trans_table(e, profile)) {
776 		info = "failed to unpack profile transition table";
777 		goto fail;
778 	}
779 
780 	if (unpack_nameX(e, AA_STRUCT, "data")) {
781 		info = "out of memory";
782 		profile->data = kzalloc(sizeof(*profile->data), GFP_KERNEL);
783 		if (!profile->data)
784 			goto fail;
785 
786 		params.nelem_hint = 3;
787 		params.key_len = sizeof(void *);
788 		params.key_offset = offsetof(struct aa_data, key);
789 		params.head_offset = offsetof(struct aa_data, head);
790 		params.hashfn = strhash;
791 		params.obj_cmpfn = datacmp;
792 
793 		if (rhashtable_init(profile->data, &params)) {
794 			info = "failed to init key, value hash table";
795 			goto fail;
796 		}
797 
798 		while (unpack_strdup(e, &key, NULL)) {
799 			data = kzalloc(sizeof(*data), GFP_KERNEL);
800 			if (!data) {
801 				kzfree(key);
802 				goto fail;
803 			}
804 
805 			data->key = key;
806 			data->size = unpack_blob(e, &data->data, NULL);
807 			data->data = kvmemdup(data->data, data->size);
808 			if (data->size && !data->data) {
809 				kzfree(data->key);
810 				kzfree(data);
811 				goto fail;
812 			}
813 
814 			rhashtable_insert_fast(profile->data, &data->head,
815 					       profile->data->p);
816 		}
817 
818 		if (!unpack_nameX(e, AA_STRUCTEND, NULL)) {
819 			info = "failed to unpack end of key, value data table";
820 			goto fail;
821 		}
822 	}
823 
824 	if (!unpack_nameX(e, AA_STRUCTEND, NULL)) {
825 		info = "failed to unpack end of profile";
826 		goto fail;
827 	}
828 
829 	return profile;
830 
831 fail:
832 	if (profile)
833 		name = NULL;
834 	else if (!name)
835 		name = "unknown";
836 	audit_iface(profile, NULL, name, info, e, error);
837 	aa_free_profile(profile);
838 
839 	return ERR_PTR(error);
840 }
841 
842 /**
843  * verify_head - unpack serialized stream header
844  * @e: serialized data read head (NOT NULL)
845  * @required: whether the header is required or optional
846  * @ns: Returns - namespace if one is specified else NULL (NOT NULL)
847  *
848  * Returns: error or 0 if header is good
849  */
verify_header(struct aa_ext * e,int required,const char ** ns)850 static int verify_header(struct aa_ext *e, int required, const char **ns)
851 {
852 	int error = -EPROTONOSUPPORT;
853 	const char *name = NULL;
854 	*ns = NULL;
855 
856 	/* get the interface version */
857 	if (!unpack_u32(e, &e->version, "version")) {
858 		if (required) {
859 			audit_iface(NULL, NULL, NULL, "invalid profile format",
860 				    e, error);
861 			return error;
862 		}
863 	}
864 
865 	/* Check that the interface version is currently supported.
866 	 * if not specified use previous version
867 	 * Mask off everything that is not kernel abi version
868 	 */
869 	if (VERSION_LT(e->version, v5) || VERSION_GT(e->version, v7)) {
870 		audit_iface(NULL, NULL, NULL, "unsupported interface version",
871 			    e, error);
872 		return error;
873 	}
874 
875 	/* read the namespace if present */
876 	if (unpack_str(e, &name, "namespace")) {
877 		if (*name == '\0') {
878 			audit_iface(NULL, NULL, NULL, "invalid namespace name",
879 				    e, error);
880 			return error;
881 		}
882 		if (*ns && strcmp(*ns, name))
883 			audit_iface(NULL, NULL, NULL, "invalid ns change", e,
884 				    error);
885 		else if (!*ns)
886 			*ns = name;
887 	}
888 
889 	return 0;
890 }
891 
verify_xindex(int xindex,int table_size)892 static bool verify_xindex(int xindex, int table_size)
893 {
894 	int index, xtype;
895 	xtype = xindex & AA_X_TYPE_MASK;
896 	index = xindex & AA_X_INDEX_MASK;
897 	if (xtype == AA_X_TABLE && index >= table_size)
898 		return 0;
899 	return 1;
900 }
901 
902 /* verify dfa xindexes are in range of transition tables */
verify_dfa_xindex(struct aa_dfa * dfa,int table_size)903 static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size)
904 {
905 	int i;
906 	for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
907 		if (!verify_xindex(dfa_user_xindex(dfa, i), table_size))
908 			return 0;
909 		if (!verify_xindex(dfa_other_xindex(dfa, i), table_size))
910 			return 0;
911 	}
912 	return 1;
913 }
914 
915 /**
916  * verify_profile - Do post unpack analysis to verify profile consistency
917  * @profile: profile to verify (NOT NULL)
918  *
919  * Returns: 0 if passes verification else error
920  */
verify_profile(struct aa_profile * profile)921 static int verify_profile(struct aa_profile *profile)
922 {
923 	if (profile->file.dfa &&
924 	    !verify_dfa_xindex(profile->file.dfa,
925 			       profile->file.trans.size)) {
926 		audit_iface(profile, NULL, NULL, "Invalid named transition",
927 			    NULL, -EPROTO);
928 		return -EPROTO;
929 	}
930 
931 	return 0;
932 }
933 
aa_load_ent_free(struct aa_load_ent * ent)934 void aa_load_ent_free(struct aa_load_ent *ent)
935 {
936 	if (ent) {
937 		aa_put_profile(ent->rename);
938 		aa_put_profile(ent->old);
939 		aa_put_profile(ent->new);
940 		kfree(ent->ns_name);
941 		kzfree(ent);
942 	}
943 }
944 
aa_load_ent_alloc(void)945 struct aa_load_ent *aa_load_ent_alloc(void)
946 {
947 	struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL);
948 	if (ent)
949 		INIT_LIST_HEAD(&ent->list);
950 	return ent;
951 }
952 
953 /**
954  * aa_unpack - unpack packed binary profile(s) data loaded from user space
955  * @udata: user data copied to kmem  (NOT NULL)
956  * @lh: list to place unpacked profiles in a aa_repl_ws
957  * @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
958  *
959  * Unpack user data and return refcounted allocated profile(s) stored in
960  * @lh in order of discovery, with the list chain stored in base.list
961  * or error
962  *
963  * Returns: profile(s) on @lh else error pointer if fails to unpack
964  */
aa_unpack(struct aa_loaddata * udata,struct list_head * lh,const char ** ns)965 int aa_unpack(struct aa_loaddata *udata, struct list_head *lh,
966 	      const char **ns)
967 {
968 	struct aa_load_ent *tmp, *ent;
969 	struct aa_profile *profile = NULL;
970 	int error;
971 	struct aa_ext e = {
972 		.start = udata->data,
973 		.end = udata->data + udata->size,
974 		.pos = udata->data,
975 	};
976 
977 	*ns = NULL;
978 	while (e.pos < e.end) {
979 		char *ns_name = NULL;
980 		void *start;
981 		error = verify_header(&e, e.pos == e.start, ns);
982 		if (error)
983 			goto fail;
984 
985 		start = e.pos;
986 		profile = unpack_profile(&e, &ns_name);
987 		if (IS_ERR(profile)) {
988 			error = PTR_ERR(profile);
989 			goto fail;
990 		}
991 
992 		error = verify_profile(profile);
993 		if (error)
994 			goto fail_profile;
995 
996 		if (aa_g_hash_policy)
997 			error = aa_calc_profile_hash(profile, e.version, start,
998 						     e.pos - start);
999 		if (error)
1000 			goto fail_profile;
1001 
1002 		ent = aa_load_ent_alloc();
1003 		if (!ent) {
1004 			error = -ENOMEM;
1005 			goto fail_profile;
1006 		}
1007 
1008 		ent->new = profile;
1009 		ent->ns_name = ns_name;
1010 		list_add_tail(&ent->list, lh);
1011 	}
1012 	udata->abi = e.version & K_ABI_MASK;
1013 	if (aa_g_hash_policy) {
1014 		udata->hash = aa_calc_hash(udata->data, udata->size);
1015 		if (IS_ERR(udata->hash)) {
1016 			error = PTR_ERR(udata->hash);
1017 			udata->hash = NULL;
1018 			goto fail;
1019 		}
1020 	}
1021 	return 0;
1022 
1023 fail_profile:
1024 	aa_put_profile(profile);
1025 
1026 fail:
1027 	list_for_each_entry_safe(ent, tmp, lh, list) {
1028 		list_del_init(&ent->list);
1029 		aa_load_ent_free(ent);
1030 	}
1031 
1032 	return error;
1033 }
1034