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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/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
52enum 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 */
73struct 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 */
81static 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 */
108static 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
127void __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
142bool 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 */
155static 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
173void 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
183struct 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 */
202static bool inbounds(struct aa_ext *e, size_t size)
203{
204 return (size <= e->end - e->pos);
205}
206
207static 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 */
223static 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 */
239static 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 */
265static 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
290fail:
291 e->pos = pos;
292 return 0;
293}
294
295static 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
308static 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
321static 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
334static 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
351static 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
368fail:
369 e->pos = pos;
370 return 0;
371}
372
373static 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#define DFA_VALID_PERM_MASK 0xffffffff
393#define DFA_VALID_PERM2_MASK 0xffffffff
394
395/**
396 * verify_accept - verify the accept tables of a dfa
397 * @dfa: dfa to verify accept tables of (NOT NULL)
398 * @flags: flags governing dfa
399 *
400 * Returns: 1 if valid accept tables else 0 if error
401 */
402static bool verify_accept(struct aa_dfa *dfa, int flags)
403{
404 int i;
405
406 /* verify accept permissions */
407 for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
408 int mode = ACCEPT_TABLE(dfa)[i];
409
410 if (mode & ~DFA_VALID_PERM_MASK)
411 return 0;
412
413 if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK)
414 return 0;
415 }
416 return 1;
417}
418
419/**
420 * unpack_dfa - unpack a file rule dfa
421 * @e: serialized data extent information (NOT NULL)
422 *
423 * returns dfa or ERR_PTR or NULL if no dfa
424 */
425static struct aa_dfa *unpack_dfa(struct aa_ext *e)
426{
427 char *blob = NULL;
428 size_t size;
429 struct aa_dfa *dfa = NULL;
430
431 size = unpack_blob(e, &blob, "aadfa");
432 if (size) {
433 /*
434 * The dfa is aligned with in the blob to 8 bytes
435 * from the beginning of the stream.
436 * alignment adjust needed by dfa unpack
437 */
438 size_t sz = blob - (char *) e->start -
439 ((e->pos - e->start) & 7);
440 size_t pad = ALIGN(sz, 8) - sz;
441 int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) |
442 TO_ACCEPT2_FLAG(YYTD_DATA32) | DFA_FLAG_VERIFY_STATES;
443 dfa = aa_dfa_unpack(blob + pad, size - pad, flags);
444
445 if (IS_ERR(dfa))
446 return dfa;
447
448 if (!verify_accept(dfa, flags))
449 goto fail;
450 }
451
452 return dfa;
453
454fail:
455 aa_put_dfa(dfa);
456 return ERR_PTR(-EPROTO);
457}
458
459/**
460 * unpack_trans_table - unpack a profile transition table
461 * @e: serialized data extent information (NOT NULL)
462 * @profile: profile to add the accept table to (NOT NULL)
463 *
464 * Returns: 1 if table successfully unpacked
465 */
466static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile)
467{
468 void *saved_pos = e->pos;
469
470 /* exec table is optional */
471 if (unpack_nameX(e, AA_STRUCT, "xtable")) {
472 int i, size;
473
474 size = unpack_array(e, NULL);
475 /* currently 4 exec bits and entries 0-3 are reserved iupcx */
476 if (size > 16 - 4)
477 goto fail;
478 profile->file.trans.table = kzalloc(sizeof(char *) * size,
479 GFP_KERNEL);
480 if (!profile->file.trans.table)
481 goto fail;
482
483 profile->file.trans.size = size;
484 for (i = 0; i < size; i++) {
485 char *str;
486 int c, j, pos, size2 = unpack_strdup(e, &str, NULL);
487 /* unpack_strdup verifies that the last character is
488 * null termination byte.
489 */
490 if (!size2)
491 goto fail;
492 profile->file.trans.table[i] = str;
493 /* verify that name doesn't start with space */
494 if (isspace(*str))
495 goto fail;
496
497 /* count internal # of internal \0 */
498 for (c = j = 0; j < size2 - 1; j++) {
499 if (!str[j]) {
500 pos = j;
501 c++;
502 }
503 }
504 if (*str == ':') {
505 /* first character after : must be valid */
506 if (!str[1])
507 goto fail;
508 /* beginning with : requires an embedded \0,
509 * verify that exactly 1 internal \0 exists
510 * trailing \0 already verified by unpack_strdup
511 *
512 * convert \0 back to : for label_parse
513 */
514 if (c == 1)
515 str[pos] = ':';
516 else if (c > 1)
517 goto fail;
518 } else if (c)
519 /* fail - all other cases with embedded \0 */
520 goto fail;
521 }
522 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
523 goto fail;
524 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
525 goto fail;
526 }
527 return 1;
528
529fail:
530 aa_free_domain_entries(&profile->file.trans);
531 e->pos = saved_pos;
532 return 0;
533}
534
535static bool unpack_xattrs(struct aa_ext *e, struct aa_profile *profile)
536{
537 void *pos = e->pos;
538
539 if (unpack_nameX(e, AA_STRUCT, "xattrs")) {
540 int i, size;
541
542 size = unpack_array(e, NULL);
543 profile->xattr_count = size;
544 profile->xattrs = kcalloc(size, sizeof(char *), GFP_KERNEL);
545 if (!profile->xattrs)
546 goto fail;
547 for (i = 0; i < size; i++) {
548 if (!unpack_strdup(e, &profile->xattrs[i], NULL))
549 goto fail;
550 }
551 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
552 goto fail;
553 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
554 goto fail;
555 }
556
557 return 1;
558
559fail:
560 e->pos = pos;
561 return 0;
562}
563
564static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile)
565{
566 void *pos = e->pos;
567
568 /* rlimits are optional */
569 if (unpack_nameX(e, AA_STRUCT, "rlimits")) {
570 int i, size;
571 u32 tmp = 0;
572 if (!unpack_u32(e, &tmp, NULL))
573 goto fail;
574 profile->rlimits.mask = tmp;
575
576 size = unpack_array(e, NULL);
577 if (size > RLIM_NLIMITS)
578 goto fail;
579 for (i = 0; i < size; i++) {
580 u64 tmp2 = 0;
581 int a = aa_map_resource(i);
582 if (!unpack_u64(e, &tmp2, NULL))
583 goto fail;
584 profile->rlimits.limits[a].rlim_max = tmp2;
585 }
586 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
587 goto fail;
588 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
589 goto fail;
590 }
591 return 1;
592
593fail:
594 e->pos = pos;
595 return 0;
596}
597
598static u32 strhash(const void *data, u32 len, u32 seed)
599{
600 const char * const *key = data;
601
602 return jhash(*key, strlen(*key), seed);
603}
604
605static int datacmp(struct rhashtable_compare_arg *arg, const void *obj)
606{
607 const struct aa_data *data = obj;
608 const char * const *key = arg->key;
609
610 return strcmp(data->key, *key);
611}
612
613/**
614 * unpack_profile - unpack a serialized profile
615 * @e: serialized data extent information (NOT NULL)
616 *
617 * NOTE: unpack profile sets audit struct if there is a failure
618 */
619static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
620{
621 struct aa_profile *profile = NULL;
622 const char *tmpname, *tmpns = NULL, *name = NULL;
623 const char *info = "failed to unpack profile";
624 size_t ns_len;
625 struct rhashtable_params params = { 0 };
626 char *key = NULL;
627 struct aa_data *data;
628 int i, error = -EPROTO;
629 kernel_cap_t tmpcap;
630 u32 tmp;
631
632 *ns_name = NULL;
633
634 /* check that we have the right struct being passed */
635 if (!unpack_nameX(e, AA_STRUCT, "profile"))
636 goto fail;
637 if (!unpack_str(e, &name, NULL))
638 goto fail;
639 if (*name == '\0')
640 goto fail;
641
642 tmpname = aa_splitn_fqname(name, strlen(name), &tmpns, &ns_len);
643 if (tmpns) {
644 *ns_name = kstrndup(tmpns, ns_len, GFP_KERNEL);
645 if (!*ns_name) {
646 info = "out of memory";
647 goto fail;
648 }
649 name = tmpname;
650 }
651
652 profile = aa_alloc_profile(name, NULL, GFP_KERNEL);
653 if (!profile)
654 return ERR_PTR(-ENOMEM);
655
656 /* profile renaming is optional */
657 (void) unpack_str(e, &profile->rename, "rename");
658
659 /* attachment string is optional */
660 (void) unpack_str(e, &profile->attach, "attach");
661
662 /* xmatch is optional and may be NULL */
663 profile->xmatch = unpack_dfa(e);
664 if (IS_ERR(profile->xmatch)) {
665 error = PTR_ERR(profile->xmatch);
666 profile->xmatch = NULL;
667 info = "bad xmatch";
668 goto fail;
669 }
670 /* xmatch_len is not optional if xmatch is set */
671 if (profile->xmatch) {
672 if (!unpack_u32(e, &tmp, NULL)) {
673 info = "missing xmatch len";
674 goto fail;
675 }
676 profile->xmatch_len = tmp;
677 }
678
679 /* disconnected attachment string is optional */
680 (void) unpack_str(e, &profile->disconnected, "disconnected");
681
682 /* per profile debug flags (complain, audit) */
683 if (!unpack_nameX(e, AA_STRUCT, "flags")) {
684 info = "profile missing flags";
685 goto fail;
686 }
687 info = "failed to unpack profile flags";
688 if (!unpack_u32(e, &tmp, NULL))
689 goto fail;
690 if (tmp & PACKED_FLAG_HAT)
691 profile->label.flags |= FLAG_HAT;
692 if (!unpack_u32(e, &tmp, NULL))
693 goto fail;
694 if (tmp == PACKED_MODE_COMPLAIN || (e->version & FORCE_COMPLAIN_FLAG))
695 profile->mode = APPARMOR_COMPLAIN;
696 else if (tmp == PACKED_MODE_KILL)
697 profile->mode = APPARMOR_KILL;
698 else if (tmp == PACKED_MODE_UNCONFINED)
699 profile->mode = APPARMOR_UNCONFINED;
700 if (!unpack_u32(e, &tmp, NULL))
701 goto fail;
702 if (tmp)
703 profile->audit = AUDIT_ALL;
704
705 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
706 goto fail;
707
708 /* path_flags is optional */
709 if (unpack_u32(e, &profile->path_flags, "path_flags"))
710 profile->path_flags |= profile->label.flags &
711 PATH_MEDIATE_DELETED;
712 else
713 /* set a default value if path_flags field is not present */
714 profile->path_flags = PATH_MEDIATE_DELETED;
715
716 info = "failed to unpack profile capabilities";
717 if (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL))
718 goto fail;
719 if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL))
720 goto fail;
721 if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL))
722 goto fail;
723 if (!unpack_u32(e, &tmpcap.cap[0], NULL))
724 goto fail;
725
726 info = "failed to unpack upper profile capabilities";
727 if (unpack_nameX(e, AA_STRUCT, "caps64")) {
728 /* optional upper half of 64 bit caps */
729 if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL))
730 goto fail;
731 if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL))
732 goto fail;
733 if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL))
734 goto fail;
735 if (!unpack_u32(e, &(tmpcap.cap[1]), NULL))
736 goto fail;
737 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
738 goto fail;
739 }
740
741 info = "failed to unpack extended profile capabilities";
742 if (unpack_nameX(e, AA_STRUCT, "capsx")) {
743 /* optional extended caps mediation mask */
744 if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL))
745 goto fail;
746 if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL))
747 goto fail;
748 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
749 goto fail;
750 }
751
752 if (!unpack_xattrs(e, profile)) {
753 info = "failed to unpack profile xattrs";
754 goto fail;
755 }
756
757 if (!unpack_rlimits(e, profile)) {
758 info = "failed to unpack profile rlimits";
759 goto fail;
760 }
761
762 if (unpack_nameX(e, AA_STRUCT, "policydb")) {
763 /* generic policy dfa - optional and may be NULL */
764 info = "failed to unpack policydb";
765 profile->policy.dfa = unpack_dfa(e);
766 if (IS_ERR(profile->policy.dfa)) {
767 error = PTR_ERR(profile->policy.dfa);
768 profile->policy.dfa = NULL;
769 goto fail;
770 } else if (!profile->policy.dfa) {
771 error = -EPROTO;
772 goto fail;
773 }
774 if (!unpack_u32(e, &profile->policy.start[0], "start"))
775 /* default start state */
776 profile->policy.start[0] = DFA_START;
777 /* setup class index */
778 for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) {
779 profile->policy.start[i] =
780 aa_dfa_next(profile->policy.dfa,
781 profile->policy.start[0],
782 i);
783 }
784 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
785 goto fail;
786 } else
787 profile->policy.dfa = aa_get_dfa(nulldfa);
788
789 /* get file rules */
790 profile->file.dfa = unpack_dfa(e);
791 if (IS_ERR(profile->file.dfa)) {
792 error = PTR_ERR(profile->file.dfa);
793 profile->file.dfa = NULL;
794 info = "failed to unpack profile file rules";
795 goto fail;
796 } else if (profile->file.dfa) {
797 if (!unpack_u32(e, &profile->file.start, "dfa_start"))
798 /* default start state */
799 profile->file.start = DFA_START;
800 } else if (profile->policy.dfa &&
801 profile->policy.start[AA_CLASS_FILE]) {
802 profile->file.dfa = aa_get_dfa(profile->policy.dfa);
803 profile->file.start = profile->policy.start[AA_CLASS_FILE];
804 } else
805 profile->file.dfa = aa_get_dfa(nulldfa);
806
807 if (!unpack_trans_table(e, profile)) {
808 info = "failed to unpack profile transition table";
809 goto fail;
810 }
811
812 if (unpack_nameX(e, AA_STRUCT, "data")) {
813 info = "out of memory";
814 profile->data = kzalloc(sizeof(*profile->data), GFP_KERNEL);
815 if (!profile->data)
816 goto fail;
817
818 params.nelem_hint = 3;
819 params.key_len = sizeof(void *);
820 params.key_offset = offsetof(struct aa_data, key);
821 params.head_offset = offsetof(struct aa_data, head);
822 params.hashfn = strhash;
823 params.obj_cmpfn = datacmp;
824
825 if (rhashtable_init(profile->data, ¶ms)) {
826 info = "failed to init key, value hash table";
827 goto fail;
828 }
829
830 while (unpack_strdup(e, &key, NULL)) {
831 data = kzalloc(sizeof(*data), GFP_KERNEL);
832 if (!data) {
833 kzfree(key);
834 goto fail;
835 }
836
837 data->key = key;
838 data->size = unpack_blob(e, &data->data, NULL);
839 data->data = kvmemdup(data->data, data->size);
840 if (data->size && !data->data) {
841 kzfree(data->key);
842 kzfree(data);
843 goto fail;
844 }
845
846 rhashtable_insert_fast(profile->data, &data->head,
847 profile->data->p);
848 }
849
850 if (!unpack_nameX(e, AA_STRUCTEND, NULL)) {
851 info = "failed to unpack end of key, value data table";
852 goto fail;
853 }
854 }
855
856 if (!unpack_nameX(e, AA_STRUCTEND, NULL)) {
857 info = "failed to unpack end of profile";
858 goto fail;
859 }
860
861 return profile;
862
863fail:
864 if (profile)
865 name = NULL;
866 else if (!name)
867 name = "unknown";
868 audit_iface(profile, NULL, name, info, e, error);
869 aa_free_profile(profile);
870
871 return ERR_PTR(error);
872}
873
874/**
875 * verify_head - unpack serialized stream header
876 * @e: serialized data read head (NOT NULL)
877 * @required: whether the header is required or optional
878 * @ns: Returns - namespace if one is specified else NULL (NOT NULL)
879 *
880 * Returns: error or 0 if header is good
881 */
882static int verify_header(struct aa_ext *e, int required, const char **ns)
883{
884 int error = -EPROTONOSUPPORT;
885 const char *name = NULL;
886 *ns = NULL;
887
888 /* get the interface version */
889 if (!unpack_u32(e, &e->version, "version")) {
890 if (required) {
891 audit_iface(NULL, NULL, NULL, "invalid profile format",
892 e, error);
893 return error;
894 }
895 }
896
897 /* Check that the interface version is currently supported.
898 * if not specified use previous version
899 * Mask off everything that is not kernel abi version
900 */
901 if (VERSION_LT(e->version, v5) || VERSION_GT(e->version, v7)) {
902 audit_iface(NULL, NULL, NULL, "unsupported interface version",
903 e, error);
904 return error;
905 }
906
907 /* read the namespace if present */
908 if (unpack_str(e, &name, "namespace")) {
909 if (*name == '\0') {
910 audit_iface(NULL, NULL, NULL, "invalid namespace name",
911 e, error);
912 return error;
913 }
914 if (*ns && strcmp(*ns, name))
915 audit_iface(NULL, NULL, NULL, "invalid ns change", e,
916 error);
917 else if (!*ns)
918 *ns = name;
919 }
920
921 return 0;
922}
923
924static bool verify_xindex(int xindex, int table_size)
925{
926 int index, xtype;
927 xtype = xindex & AA_X_TYPE_MASK;
928 index = xindex & AA_X_INDEX_MASK;
929 if (xtype == AA_X_TABLE && index >= table_size)
930 return 0;
931 return 1;
932}
933
934/* verify dfa xindexes are in range of transition tables */
935static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size)
936{
937 int i;
938 for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
939 if (!verify_xindex(dfa_user_xindex(dfa, i), table_size))
940 return 0;
941 if (!verify_xindex(dfa_other_xindex(dfa, i), table_size))
942 return 0;
943 }
944 return 1;
945}
946
947/**
948 * verify_profile - Do post unpack analysis to verify profile consistency
949 * @profile: profile to verify (NOT NULL)
950 *
951 * Returns: 0 if passes verification else error
952 */
953static int verify_profile(struct aa_profile *profile)
954{
955 if (profile->file.dfa &&
956 !verify_dfa_xindex(profile->file.dfa,
957 profile->file.trans.size)) {
958 audit_iface(profile, NULL, NULL, "Invalid named transition",
959 NULL, -EPROTO);
960 return -EPROTO;
961 }
962
963 return 0;
964}
965
966void aa_load_ent_free(struct aa_load_ent *ent)
967{
968 if (ent) {
969 aa_put_profile(ent->rename);
970 aa_put_profile(ent->old);
971 aa_put_profile(ent->new);
972 kfree(ent->ns_name);
973 kzfree(ent);
974 }
975}
976
977struct aa_load_ent *aa_load_ent_alloc(void)
978{
979 struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL);
980 if (ent)
981 INIT_LIST_HEAD(&ent->list);
982 return ent;
983}
984
985/**
986 * aa_unpack - unpack packed binary profile(s) data loaded from user space
987 * @udata: user data copied to kmem (NOT NULL)
988 * @lh: list to place unpacked profiles in a aa_repl_ws
989 * @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
990 *
991 * Unpack user data and return refcounted allocated profile(s) stored in
992 * @lh in order of discovery, with the list chain stored in base.list
993 * or error
994 *
995 * Returns: profile(s) on @lh else error pointer if fails to unpack
996 */
997int aa_unpack(struct aa_loaddata *udata, struct list_head *lh,
998 const char **ns)
999{
1000 struct aa_load_ent *tmp, *ent;
1001 struct aa_profile *profile = NULL;
1002 int error;
1003 struct aa_ext e = {
1004 .start = udata->data,
1005 .end = udata->data + udata->size,
1006 .pos = udata->data,
1007 };
1008
1009 *ns = NULL;
1010 while (e.pos < e.end) {
1011 char *ns_name = NULL;
1012 void *start;
1013 error = verify_header(&e, e.pos == e.start, ns);
1014 if (error)
1015 goto fail;
1016
1017 start = e.pos;
1018 profile = unpack_profile(&e, &ns_name);
1019 if (IS_ERR(profile)) {
1020 error = PTR_ERR(profile);
1021 goto fail;
1022 }
1023
1024 error = verify_profile(profile);
1025 if (error)
1026 goto fail_profile;
1027
1028 if (aa_g_hash_policy)
1029 error = aa_calc_profile_hash(profile, e.version, start,
1030 e.pos - start);
1031 if (error)
1032 goto fail_profile;
1033
1034 ent = aa_load_ent_alloc();
1035 if (!ent) {
1036 error = -ENOMEM;
1037 goto fail_profile;
1038 }
1039
1040 ent->new = profile;
1041 ent->ns_name = ns_name;
1042 list_add_tail(&ent->list, lh);
1043 }
1044 udata->abi = e.version & K_ABI_MASK;
1045 if (aa_g_hash_policy) {
1046 udata->hash = aa_calc_hash(udata->data, udata->size);
1047 if (IS_ERR(udata->hash)) {
1048 error = PTR_ERR(udata->hash);
1049 udata->hash = NULL;
1050 goto fail;
1051 }
1052 }
1053 return 0;
1054
1055fail_profile:
1056 aa_put_profile(profile);
1057
1058fail:
1059 list_for_each_entry_safe(ent, tmp, lh, list) {
1060 list_del_init(&ent->list);
1061 aa_load_ent_free(ent);
1062 }
1063
1064 return error;
1065}
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 look in Documentation/security/apparmor.txt
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/policy.h"
30#include "include/policy_unpack.h"
31
32/*
33 * The AppArmor interface treats data as a type byte followed by the
34 * actual data. The interface has the notion of a a named entry
35 * which has a name (AA_NAME typecode followed by name string) followed by
36 * the entries typecode and data. Named types allow for optional
37 * elements and extensions to be added and tested for without breaking
38 * backwards compatibility.
39 */
40
41enum aa_code {
42 AA_U8,
43 AA_U16,
44 AA_U32,
45 AA_U64,
46 AA_NAME, /* same as string except it is items name */
47 AA_STRING,
48 AA_BLOB,
49 AA_STRUCT,
50 AA_STRUCTEND,
51 AA_LIST,
52 AA_LISTEND,
53 AA_ARRAY,
54 AA_ARRAYEND,
55};
56
57/*
58 * aa_ext is the read of the buffer containing the serialized profile. The
59 * data is copied into a kernel buffer in apparmorfs and then handed off to
60 * the unpack routines.
61 */
62struct aa_ext {
63 void *start;
64 void *end;
65 void *pos; /* pointer to current position in the buffer */
66 u32 version;
67};
68
69/* audit callback for unpack fields */
70static void audit_cb(struct audit_buffer *ab, void *va)
71{
72 struct common_audit_data *sa = va;
73 if (sa->aad->iface.target) {
74 struct aa_profile *name = sa->aad->iface.target;
75 audit_log_format(ab, " name=");
76 audit_log_untrustedstring(ab, name->base.hname);
77 }
78 if (sa->aad->iface.pos)
79 audit_log_format(ab, " offset=%ld", sa->aad->iface.pos);
80}
81
82/**
83 * audit_iface - do audit message for policy unpacking/load/replace/remove
84 * @new: profile if it has been allocated (MAYBE NULL)
85 * @name: name of the profile being manipulated (MAYBE NULL)
86 * @info: any extra info about the failure (MAYBE NULL)
87 * @e: buffer position info
88 * @error: error code
89 *
90 * Returns: %0 or error
91 */
92static int audit_iface(struct aa_profile *new, const char *name,
93 const char *info, struct aa_ext *e, int error)
94{
95 struct aa_profile *profile = __aa_current_profile();
96 struct common_audit_data sa;
97 struct apparmor_audit_data aad = {0,};
98 sa.type = LSM_AUDIT_DATA_NONE;
99 sa.aad = &aad;
100 if (e)
101 aad.iface.pos = e->pos - e->start;
102 aad.iface.target = new;
103 aad.name = name;
104 aad.info = info;
105 aad.error = error;
106
107 return aa_audit(AUDIT_APPARMOR_STATUS, profile, GFP_KERNEL, &sa,
108 audit_cb);
109}
110
111/* test if read will be in packed data bounds */
112static bool inbounds(struct aa_ext *e, size_t size)
113{
114 return (size <= e->end - e->pos);
115}
116
117/**
118 * aa_u16_chunck - test and do bounds checking for a u16 size based chunk
119 * @e: serialized data read head (NOT NULL)
120 * @chunk: start address for chunk of data (NOT NULL)
121 *
122 * Returns: the size of chunk found with the read head at the end of the chunk.
123 */
124static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk)
125{
126 size_t size = 0;
127
128 if (!inbounds(e, sizeof(u16)))
129 return 0;
130 size = le16_to_cpu(get_unaligned((u16 *) e->pos));
131 e->pos += sizeof(u16);
132 if (!inbounds(e, size))
133 return 0;
134 *chunk = e->pos;
135 e->pos += size;
136 return size;
137}
138
139/* unpack control byte */
140static bool unpack_X(struct aa_ext *e, enum aa_code code)
141{
142 if (!inbounds(e, 1))
143 return 0;
144 if (*(u8 *) e->pos != code)
145 return 0;
146 e->pos++;
147 return 1;
148}
149
150/**
151 * unpack_nameX - check is the next element is of type X with a name of @name
152 * @e: serialized data extent information (NOT NULL)
153 * @code: type code
154 * @name: name to match to the serialized element. (MAYBE NULL)
155 *
156 * check that the next serialized data element is of type X and has a tag
157 * name @name. If @name is specified then there must be a matching
158 * name element in the stream. If @name is NULL any name element will be
159 * skipped and only the typecode will be tested.
160 *
161 * Returns 1 on success (both type code and name tests match) and the read
162 * head is advanced past the headers
163 *
164 * Returns: 0 if either match fails, the read head does not move
165 */
166static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
167{
168 /*
169 * May need to reset pos if name or type doesn't match
170 */
171 void *pos = e->pos;
172 /*
173 * Check for presence of a tagname, and if present name size
174 * AA_NAME tag value is a u16.
175 */
176 if (unpack_X(e, AA_NAME)) {
177 char *tag = NULL;
178 size_t size = unpack_u16_chunk(e, &tag);
179 /* if a name is specified it must match. otherwise skip tag */
180 if (name && (!size || strcmp(name, tag)))
181 goto fail;
182 } else if (name) {
183 /* if a name is specified and there is no name tag fail */
184 goto fail;
185 }
186
187 /* now check if type code matches */
188 if (unpack_X(e, code))
189 return 1;
190
191fail:
192 e->pos = pos;
193 return 0;
194}
195
196static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
197{
198 if (unpack_nameX(e, AA_U32, name)) {
199 if (!inbounds(e, sizeof(u32)))
200 return 0;
201 if (data)
202 *data = le32_to_cpu(get_unaligned((u32 *) e->pos));
203 e->pos += sizeof(u32);
204 return 1;
205 }
206 return 0;
207}
208
209static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name)
210{
211 if (unpack_nameX(e, AA_U64, name)) {
212 if (!inbounds(e, sizeof(u64)))
213 return 0;
214 if (data)
215 *data = le64_to_cpu(get_unaligned((u64 *) e->pos));
216 e->pos += sizeof(u64);
217 return 1;
218 }
219 return 0;
220}
221
222static size_t unpack_array(struct aa_ext *e, const char *name)
223{
224 if (unpack_nameX(e, AA_ARRAY, name)) {
225 int size;
226 if (!inbounds(e, sizeof(u16)))
227 return 0;
228 size = (int)le16_to_cpu(get_unaligned((u16 *) e->pos));
229 e->pos += sizeof(u16);
230 return size;
231 }
232 return 0;
233}
234
235static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
236{
237 if (unpack_nameX(e, AA_BLOB, name)) {
238 u32 size;
239 if (!inbounds(e, sizeof(u32)))
240 return 0;
241 size = le32_to_cpu(get_unaligned((u32 *) e->pos));
242 e->pos += sizeof(u32);
243 if (inbounds(e, (size_t) size)) {
244 *blob = e->pos;
245 e->pos += size;
246 return size;
247 }
248 }
249 return 0;
250}
251
252static int unpack_str(struct aa_ext *e, const char **string, const char *name)
253{
254 char *src_str;
255 size_t size = 0;
256 void *pos = e->pos;
257 *string = NULL;
258 if (unpack_nameX(e, AA_STRING, name)) {
259 size = unpack_u16_chunk(e, &src_str);
260 if (size) {
261 /* strings are null terminated, length is size - 1 */
262 if (src_str[size - 1] != 0)
263 goto fail;
264 *string = src_str;
265 }
266 }
267 return size;
268
269fail:
270 e->pos = pos;
271 return 0;
272}
273
274static int unpack_strdup(struct aa_ext *e, char **string, const char *name)
275{
276 const char *tmp;
277 void *pos = e->pos;
278 int res = unpack_str(e, &tmp, name);
279 *string = NULL;
280
281 if (!res)
282 return 0;
283
284 *string = kmemdup(tmp, res, GFP_KERNEL);
285 if (!*string) {
286 e->pos = pos;
287 return 0;
288 }
289
290 return res;
291}
292
293#define DFA_VALID_PERM_MASK 0xffffffff
294#define DFA_VALID_PERM2_MASK 0xffffffff
295
296/**
297 * verify_accept - verify the accept tables of a dfa
298 * @dfa: dfa to verify accept tables of (NOT NULL)
299 * @flags: flags governing dfa
300 *
301 * Returns: 1 if valid accept tables else 0 if error
302 */
303static bool verify_accept(struct aa_dfa *dfa, int flags)
304{
305 int i;
306
307 /* verify accept permissions */
308 for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
309 int mode = ACCEPT_TABLE(dfa)[i];
310
311 if (mode & ~DFA_VALID_PERM_MASK)
312 return 0;
313
314 if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK)
315 return 0;
316 }
317 return 1;
318}
319
320/**
321 * unpack_dfa - unpack a file rule dfa
322 * @e: serialized data extent information (NOT NULL)
323 *
324 * returns dfa or ERR_PTR or NULL if no dfa
325 */
326static struct aa_dfa *unpack_dfa(struct aa_ext *e)
327{
328 char *blob = NULL;
329 size_t size;
330 struct aa_dfa *dfa = NULL;
331
332 size = unpack_blob(e, &blob, "aadfa");
333 if (size) {
334 /*
335 * The dfa is aligned with in the blob to 8 bytes
336 * from the beginning of the stream.
337 * alignment adjust needed by dfa unpack
338 */
339 size_t sz = blob - (char *) e->start -
340 ((e->pos - e->start) & 7);
341 size_t pad = ALIGN(sz, 8) - sz;
342 int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) |
343 TO_ACCEPT2_FLAG(YYTD_DATA32);
344
345
346 if (aa_g_paranoid_load)
347 flags |= DFA_FLAG_VERIFY_STATES;
348
349 dfa = aa_dfa_unpack(blob + pad, size - pad, flags);
350
351 if (IS_ERR(dfa))
352 return dfa;
353
354 if (!verify_accept(dfa, flags))
355 goto fail;
356 }
357
358 return dfa;
359
360fail:
361 aa_put_dfa(dfa);
362 return ERR_PTR(-EPROTO);
363}
364
365/**
366 * unpack_trans_table - unpack a profile transition table
367 * @e: serialized data extent information (NOT NULL)
368 * @profile: profile to add the accept table to (NOT NULL)
369 *
370 * Returns: 1 if table successfully unpacked
371 */
372static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile)
373{
374 void *pos = e->pos;
375
376 /* exec table is optional */
377 if (unpack_nameX(e, AA_STRUCT, "xtable")) {
378 int i, size;
379
380 size = unpack_array(e, NULL);
381 /* currently 4 exec bits and entries 0-3 are reserved iupcx */
382 if (size > 16 - 4)
383 goto fail;
384 profile->file.trans.table = kzalloc(sizeof(char *) * size,
385 GFP_KERNEL);
386 if (!profile->file.trans.table)
387 goto fail;
388
389 profile->file.trans.size = size;
390 for (i = 0; i < size; i++) {
391 char *str;
392 int c, j, size2 = unpack_strdup(e, &str, NULL);
393 /* unpack_strdup verifies that the last character is
394 * null termination byte.
395 */
396 if (!size2)
397 goto fail;
398 profile->file.trans.table[i] = str;
399 /* verify that name doesn't start with space */
400 if (isspace(*str))
401 goto fail;
402
403 /* count internal # of internal \0 */
404 for (c = j = 0; j < size2 - 2; j++) {
405 if (!str[j])
406 c++;
407 }
408 if (*str == ':') {
409 /* beginning with : requires an embedded \0,
410 * verify that exactly 1 internal \0 exists
411 * trailing \0 already verified by unpack_strdup
412 */
413 if (c != 1)
414 goto fail;
415 /* first character after : must be valid */
416 if (!str[1])
417 goto fail;
418 } else if (c)
419 /* fail - all other cases with embedded \0 */
420 goto fail;
421 }
422 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
423 goto fail;
424 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
425 goto fail;
426 }
427 return 1;
428
429fail:
430 aa_free_domain_entries(&profile->file.trans);
431 e->pos = pos;
432 return 0;
433}
434
435static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile)
436{
437 void *pos = e->pos;
438
439 /* rlimits are optional */
440 if (unpack_nameX(e, AA_STRUCT, "rlimits")) {
441 int i, size;
442 u32 tmp = 0;
443 if (!unpack_u32(e, &tmp, NULL))
444 goto fail;
445 profile->rlimits.mask = tmp;
446
447 size = unpack_array(e, NULL);
448 if (size > RLIM_NLIMITS)
449 goto fail;
450 for (i = 0; i < size; i++) {
451 u64 tmp2 = 0;
452 int a = aa_map_resource(i);
453 if (!unpack_u64(e, &tmp2, NULL))
454 goto fail;
455 profile->rlimits.limits[a].rlim_max = tmp2;
456 }
457 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
458 goto fail;
459 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
460 goto fail;
461 }
462 return 1;
463
464fail:
465 e->pos = pos;
466 return 0;
467}
468
469/**
470 * unpack_profile - unpack a serialized profile
471 * @e: serialized data extent information (NOT NULL)
472 *
473 * NOTE: unpack profile sets audit struct if there is a failure
474 */
475static struct aa_profile *unpack_profile(struct aa_ext *e)
476{
477 struct aa_profile *profile = NULL;
478 const char *name = NULL;
479 int i, error = -EPROTO;
480 kernel_cap_t tmpcap;
481 u32 tmp;
482
483 /* check that we have the right struct being passed */
484 if (!unpack_nameX(e, AA_STRUCT, "profile"))
485 goto fail;
486 if (!unpack_str(e, &name, NULL))
487 goto fail;
488
489 profile = aa_alloc_profile(name);
490 if (!profile)
491 return ERR_PTR(-ENOMEM);
492
493 /* profile renaming is optional */
494 (void) unpack_str(e, &profile->rename, "rename");
495
496 /* attachment string is optional */
497 (void) unpack_str(e, &profile->attach, "attach");
498
499 /* xmatch is optional and may be NULL */
500 profile->xmatch = unpack_dfa(e);
501 if (IS_ERR(profile->xmatch)) {
502 error = PTR_ERR(profile->xmatch);
503 profile->xmatch = NULL;
504 goto fail;
505 }
506 /* xmatch_len is not optional if xmatch is set */
507 if (profile->xmatch) {
508 if (!unpack_u32(e, &tmp, NULL))
509 goto fail;
510 profile->xmatch_len = tmp;
511 }
512
513 /* per profile debug flags (complain, audit) */
514 if (!unpack_nameX(e, AA_STRUCT, "flags"))
515 goto fail;
516 if (!unpack_u32(e, &tmp, NULL))
517 goto fail;
518 if (tmp & PACKED_FLAG_HAT)
519 profile->flags |= PFLAG_HAT;
520 if (!unpack_u32(e, &tmp, NULL))
521 goto fail;
522 if (tmp == PACKED_MODE_COMPLAIN)
523 profile->mode = APPARMOR_COMPLAIN;
524 else if (tmp == PACKED_MODE_KILL)
525 profile->mode = APPARMOR_KILL;
526 else if (tmp == PACKED_MODE_UNCONFINED)
527 profile->mode = APPARMOR_UNCONFINED;
528 if (!unpack_u32(e, &tmp, NULL))
529 goto fail;
530 if (tmp)
531 profile->audit = AUDIT_ALL;
532
533 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
534 goto fail;
535
536 /* path_flags is optional */
537 if (unpack_u32(e, &profile->path_flags, "path_flags"))
538 profile->path_flags |= profile->flags & PFLAG_MEDIATE_DELETED;
539 else
540 /* set a default value if path_flags field is not present */
541 profile->path_flags = PFLAG_MEDIATE_DELETED;
542
543 if (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL))
544 goto fail;
545 if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL))
546 goto fail;
547 if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL))
548 goto fail;
549 if (!unpack_u32(e, &tmpcap.cap[0], NULL))
550 goto fail;
551
552 if (unpack_nameX(e, AA_STRUCT, "caps64")) {
553 /* optional upper half of 64 bit caps */
554 if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL))
555 goto fail;
556 if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL))
557 goto fail;
558 if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL))
559 goto fail;
560 if (!unpack_u32(e, &(tmpcap.cap[1]), NULL))
561 goto fail;
562 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
563 goto fail;
564 }
565
566 if (unpack_nameX(e, AA_STRUCT, "capsx")) {
567 /* optional extended caps mediation mask */
568 if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL))
569 goto fail;
570 if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL))
571 goto fail;
572 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
573 goto fail;
574 }
575
576 if (!unpack_rlimits(e, profile))
577 goto fail;
578
579 if (unpack_nameX(e, AA_STRUCT, "policydb")) {
580 /* generic policy dfa - optional and may be NULL */
581 profile->policy.dfa = unpack_dfa(e);
582 if (IS_ERR(profile->policy.dfa)) {
583 error = PTR_ERR(profile->policy.dfa);
584 profile->policy.dfa = NULL;
585 goto fail;
586 } else if (!profile->policy.dfa) {
587 error = -EPROTO;
588 goto fail;
589 }
590 if (!unpack_u32(e, &profile->policy.start[0], "start"))
591 /* default start state */
592 profile->policy.start[0] = DFA_START;
593 /* setup class index */
594 for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) {
595 profile->policy.start[i] =
596 aa_dfa_next(profile->policy.dfa,
597 profile->policy.start[0],
598 i);
599 }
600 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
601 goto fail;
602 }
603
604 /* get file rules */
605 profile->file.dfa = unpack_dfa(e);
606 if (IS_ERR(profile->file.dfa)) {
607 error = PTR_ERR(profile->file.dfa);
608 profile->file.dfa = NULL;
609 goto fail;
610 }
611
612 if (!unpack_u32(e, &profile->file.start, "dfa_start"))
613 /* default start state */
614 profile->file.start = DFA_START;
615
616 if (!unpack_trans_table(e, profile))
617 goto fail;
618
619 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
620 goto fail;
621
622 return profile;
623
624fail:
625 if (profile)
626 name = NULL;
627 else if (!name)
628 name = "unknown";
629 audit_iface(profile, name, "failed to unpack profile", e, error);
630 aa_free_profile(profile);
631
632 return ERR_PTR(error);
633}
634
635/**
636 * verify_head - unpack serialized stream header
637 * @e: serialized data read head (NOT NULL)
638 * @required: whether the header is required or optional
639 * @ns: Returns - namespace if one is specified else NULL (NOT NULL)
640 *
641 * Returns: error or 0 if header is good
642 */
643static int verify_header(struct aa_ext *e, int required, const char **ns)
644{
645 int error = -EPROTONOSUPPORT;
646 const char *name = NULL;
647 *ns = NULL;
648
649 /* get the interface version */
650 if (!unpack_u32(e, &e->version, "version")) {
651 if (required) {
652 audit_iface(NULL, NULL, "invalid profile format", e,
653 error);
654 return error;
655 }
656
657 /* check that the interface version is currently supported */
658 if (e->version != 5) {
659 audit_iface(NULL, NULL, "unsupported interface version",
660 e, error);
661 return error;
662 }
663 }
664
665
666 /* read the namespace if present */
667 if (unpack_str(e, &name, "namespace")) {
668 if (*ns && strcmp(*ns, name))
669 audit_iface(NULL, NULL, "invalid ns change", e, error);
670 else if (!*ns)
671 *ns = name;
672 }
673
674 return 0;
675}
676
677static bool verify_xindex(int xindex, int table_size)
678{
679 int index, xtype;
680 xtype = xindex & AA_X_TYPE_MASK;
681 index = xindex & AA_X_INDEX_MASK;
682 if (xtype == AA_X_TABLE && index >= table_size)
683 return 0;
684 return 1;
685}
686
687/* verify dfa xindexes are in range of transition tables */
688static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size)
689{
690 int i;
691 for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
692 if (!verify_xindex(dfa_user_xindex(dfa, i), table_size))
693 return 0;
694 if (!verify_xindex(dfa_other_xindex(dfa, i), table_size))
695 return 0;
696 }
697 return 1;
698}
699
700/**
701 * verify_profile - Do post unpack analysis to verify profile consistency
702 * @profile: profile to verify (NOT NULL)
703 *
704 * Returns: 0 if passes verification else error
705 */
706static int verify_profile(struct aa_profile *profile)
707{
708 if (aa_g_paranoid_load) {
709 if (profile->file.dfa &&
710 !verify_dfa_xindex(profile->file.dfa,
711 profile->file.trans.size)) {
712 audit_iface(profile, NULL, "Invalid named transition",
713 NULL, -EPROTO);
714 return -EPROTO;
715 }
716 }
717
718 return 0;
719}
720
721void aa_load_ent_free(struct aa_load_ent *ent)
722{
723 if (ent) {
724 aa_put_profile(ent->rename);
725 aa_put_profile(ent->old);
726 aa_put_profile(ent->new);
727 kzfree(ent);
728 }
729}
730
731struct aa_load_ent *aa_load_ent_alloc(void)
732{
733 struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL);
734 if (ent)
735 INIT_LIST_HEAD(&ent->list);
736 return ent;
737}
738
739/**
740 * aa_unpack - unpack packed binary profile(s) data loaded from user space
741 * @udata: user data copied to kmem (NOT NULL)
742 * @size: the size of the user data
743 * @lh: list to place unpacked profiles in a aa_repl_ws
744 * @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
745 *
746 * Unpack user data and return refcounted allocated profile(s) stored in
747 * @lh in order of discovery, with the list chain stored in base.list
748 * or error
749 *
750 * Returns: profile(s) on @lh else error pointer if fails to unpack
751 */
752int aa_unpack(void *udata, size_t size, struct list_head *lh, const char **ns)
753{
754 struct aa_load_ent *tmp, *ent;
755 struct aa_profile *profile = NULL;
756 int error;
757 struct aa_ext e = {
758 .start = udata,
759 .end = udata + size,
760 .pos = udata,
761 };
762
763 *ns = NULL;
764 while (e.pos < e.end) {
765 void *start;
766 error = verify_header(&e, e.pos == e.start, ns);
767 if (error)
768 goto fail;
769
770 start = e.pos;
771 profile = unpack_profile(&e);
772 if (IS_ERR(profile)) {
773 error = PTR_ERR(profile);
774 goto fail;
775 }
776
777 error = verify_profile(profile);
778 if (error)
779 goto fail_profile;
780
781 error = aa_calc_profile_hash(profile, e.version, start,
782 e.pos - start);
783 if (error)
784 goto fail_profile;
785
786 ent = aa_load_ent_alloc();
787 if (!ent) {
788 error = -ENOMEM;
789 goto fail_profile;
790 }
791
792 ent->new = profile;
793 list_add_tail(&ent->list, lh);
794 }
795
796 return 0;
797
798fail_profile:
799 aa_put_profile(profile);
800
801fail:
802 list_for_each_entry_safe(ent, tmp, lh, list) {
803 list_del_init(&ent->list);
804 aa_load_ent_free(ent);
805 }
806
807 return error;
808}