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