Commit | Line | Data |
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736ec752 JJ |
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 | * | |
d410fa4e RD |
15 | * AppArmor uses a serialized binary format for loading policy. To find |
16 | * policy format documentation look in Documentation/security/apparmor.txt | |
736ec752 JJ |
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/match.h" | |
28 | #include "include/policy.h" | |
29 | #include "include/policy_unpack.h" | |
736ec752 JJ |
30 | |
31 | /* | |
32 | * The AppArmor interface treats data as a type byte followed by the | |
33 | * actual data. The interface has the notion of a a named entry | |
34 | * which has a name (AA_NAME typecode followed by name string) followed by | |
35 | * the entries typecode and data. Named types allow for optional | |
36 | * elements and extensions to be added and tested for without breaking | |
37 | * backwards compatibility. | |
38 | */ | |
39 | ||
40 | enum aa_code { | |
41 | AA_U8, | |
42 | AA_U16, | |
43 | AA_U32, | |
44 | AA_U64, | |
45 | AA_NAME, /* same as string except it is items name */ | |
46 | AA_STRING, | |
47 | AA_BLOB, | |
48 | AA_STRUCT, | |
49 | AA_STRUCTEND, | |
50 | AA_LIST, | |
51 | AA_LISTEND, | |
52 | AA_ARRAY, | |
53 | AA_ARRAYEND, | |
54 | }; | |
55 | ||
56 | /* | |
57 | * aa_ext is the read of the buffer containing the serialized profile. The | |
58 | * data is copied into a kernel buffer in apparmorfs and then handed off to | |
59 | * the unpack routines. | |
60 | */ | |
61 | struct aa_ext { | |
62 | void *start; | |
63 | void *end; | |
64 | void *pos; /* pointer to current position in the buffer */ | |
65 | u32 version; | |
66 | }; | |
67 | ||
68 | /* audit callback for unpack fields */ | |
69 | static void audit_cb(struct audit_buffer *ab, void *va) | |
70 | { | |
71 | struct common_audit_data *sa = va; | |
3b3b0e4f EP |
72 | if (sa->aad->iface.target) { |
73 | struct aa_profile *name = sa->aad->iface.target; | |
736ec752 JJ |
74 | audit_log_format(ab, " name="); |
75 | audit_log_untrustedstring(ab, name->base.hname); | |
76 | } | |
3b3b0e4f EP |
77 | if (sa->aad->iface.pos) |
78 | audit_log_format(ab, " offset=%ld", sa->aad->iface.pos); | |
736ec752 JJ |
79 | } |
80 | ||
81 | /** | |
82 | * audit_iface - do audit message for policy unpacking/load/replace/remove | |
83 | * @new: profile if it has been allocated (MAYBE NULL) | |
84 | * @name: name of the profile being manipulated (MAYBE NULL) | |
85 | * @info: any extra info about the failure (MAYBE NULL) | |
b1b4bc2e | 86 | * @e: buffer position info |
736ec752 JJ |
87 | * @error: error code |
88 | * | |
89 | * Returns: %0 or error | |
90 | */ | |
91 | static int audit_iface(struct aa_profile *new, const char *name, | |
92 | const char *info, struct aa_ext *e, int error) | |
93 | { | |
94 | struct aa_profile *profile = __aa_current_profile(); | |
95 | struct common_audit_data sa; | |
3b3b0e4f | 96 | struct apparmor_audit_data aad = {0,}; |
50c205f5 | 97 | sa.type = LSM_AUDIT_DATA_NONE; |
3b3b0e4f | 98 | sa.aad = &aad; |
b1b4bc2e | 99 | if (e) |
3b3b0e4f EP |
100 | aad.iface.pos = e->pos - e->start; |
101 | aad.iface.target = new; | |
102 | aad.name = name; | |
103 | aad.info = info; | |
104 | aad.error = error; | |
736ec752 JJ |
105 | |
106 | return aa_audit(AUDIT_APPARMOR_STATUS, profile, GFP_KERNEL, &sa, | |
107 | audit_cb); | |
108 | } | |
109 | ||
110 | /* test if read will be in packed data bounds */ | |
111 | static bool inbounds(struct aa_ext *e, size_t size) | |
112 | { | |
113 | return (size <= e->end - e->pos); | |
114 | } | |
115 | ||
116 | /** | |
117 | * aa_u16_chunck - test and do bounds checking for a u16 size based chunk | |
118 | * @e: serialized data read head (NOT NULL) | |
119 | * @chunk: start address for chunk of data (NOT NULL) | |
120 | * | |
121 | * Returns: the size of chunk found with the read head at the end of the chunk. | |
122 | */ | |
123 | static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk) | |
124 | { | |
125 | size_t size = 0; | |
126 | ||
127 | if (!inbounds(e, sizeof(u16))) | |
128 | return 0; | |
129 | size = le16_to_cpu(get_unaligned((u16 *) e->pos)); | |
130 | e->pos += sizeof(u16); | |
131 | if (!inbounds(e, size)) | |
132 | return 0; | |
133 | *chunk = e->pos; | |
134 | e->pos += size; | |
135 | return size; | |
136 | } | |
137 | ||
138 | /* unpack control byte */ | |
139 | static bool unpack_X(struct aa_ext *e, enum aa_code code) | |
140 | { | |
141 | if (!inbounds(e, 1)) | |
142 | return 0; | |
143 | if (*(u8 *) e->pos != code) | |
144 | return 0; | |
145 | e->pos++; | |
146 | return 1; | |
147 | } | |
148 | ||
149 | /** | |
150 | * unpack_nameX - check is the next element is of type X with a name of @name | |
151 | * @e: serialized data extent information (NOT NULL) | |
152 | * @code: type code | |
153 | * @name: name to match to the serialized element. (MAYBE NULL) | |
154 | * | |
155 | * check that the next serialized data element is of type X and has a tag | |
156 | * name @name. If @name is specified then there must be a matching | |
157 | * name element in the stream. If @name is NULL any name element will be | |
158 | * skipped and only the typecode will be tested. | |
159 | * | |
160 | * Returns 1 on success (both type code and name tests match) and the read | |
161 | * head is advanced past the headers | |
162 | * | |
163 | * Returns: 0 if either match fails, the read head does not move | |
164 | */ | |
165 | static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name) | |
166 | { | |
167 | /* | |
168 | * May need to reset pos if name or type doesn't match | |
169 | */ | |
170 | void *pos = e->pos; | |
171 | /* | |
172 | * Check for presence of a tagname, and if present name size | |
173 | * AA_NAME tag value is a u16. | |
174 | */ | |
175 | if (unpack_X(e, AA_NAME)) { | |
176 | char *tag = NULL; | |
177 | size_t size = unpack_u16_chunk(e, &tag); | |
178 | /* if a name is specified it must match. otherwise skip tag */ | |
179 | if (name && (!size || strcmp(name, tag))) | |
180 | goto fail; | |
181 | } else if (name) { | |
182 | /* if a name is specified and there is no name tag fail */ | |
183 | goto fail; | |
184 | } | |
185 | ||
186 | /* now check if type code matches */ | |
187 | if (unpack_X(e, code)) | |
188 | return 1; | |
189 | ||
190 | fail: | |
191 | e->pos = pos; | |
192 | return 0; | |
193 | } | |
194 | ||
195 | static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name) | |
196 | { | |
197 | if (unpack_nameX(e, AA_U32, name)) { | |
198 | if (!inbounds(e, sizeof(u32))) | |
199 | return 0; | |
200 | if (data) | |
201 | *data = le32_to_cpu(get_unaligned((u32 *) e->pos)); | |
202 | e->pos += sizeof(u32); | |
203 | return 1; | |
204 | } | |
205 | return 0; | |
206 | } | |
207 | ||
208 | static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name) | |
209 | { | |
210 | if (unpack_nameX(e, AA_U64, name)) { | |
211 | if (!inbounds(e, sizeof(u64))) | |
212 | return 0; | |
213 | if (data) | |
214 | *data = le64_to_cpu(get_unaligned((u64 *) e->pos)); | |
215 | e->pos += sizeof(u64); | |
216 | return 1; | |
217 | } | |
218 | return 0; | |
219 | } | |
220 | ||
221 | static size_t unpack_array(struct aa_ext *e, const char *name) | |
222 | { | |
223 | if (unpack_nameX(e, AA_ARRAY, name)) { | |
224 | int size; | |
225 | if (!inbounds(e, sizeof(u16))) | |
226 | return 0; | |
227 | size = (int)le16_to_cpu(get_unaligned((u16 *) e->pos)); | |
228 | e->pos += sizeof(u16); | |
229 | return size; | |
230 | } | |
231 | return 0; | |
232 | } | |
233 | ||
234 | static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name) | |
235 | { | |
236 | if (unpack_nameX(e, AA_BLOB, name)) { | |
237 | u32 size; | |
238 | if (!inbounds(e, sizeof(u32))) | |
239 | return 0; | |
240 | size = le32_to_cpu(get_unaligned((u32 *) e->pos)); | |
241 | e->pos += sizeof(u32); | |
242 | if (inbounds(e, (size_t) size)) { | |
243 | *blob = e->pos; | |
244 | e->pos += size; | |
245 | return size; | |
246 | } | |
247 | } | |
248 | return 0; | |
249 | } | |
250 | ||
251 | static int unpack_str(struct aa_ext *e, const char **string, const char *name) | |
252 | { | |
253 | char *src_str; | |
254 | size_t size = 0; | |
255 | void *pos = e->pos; | |
256 | *string = NULL; | |
257 | if (unpack_nameX(e, AA_STRING, name)) { | |
258 | size = unpack_u16_chunk(e, &src_str); | |
259 | if (size) { | |
260 | /* strings are null terminated, length is size - 1 */ | |
261 | if (src_str[size - 1] != 0) | |
262 | goto fail; | |
263 | *string = src_str; | |
264 | } | |
265 | } | |
266 | return size; | |
267 | ||
268 | fail: | |
269 | e->pos = pos; | |
270 | return 0; | |
271 | } | |
272 | ||
273 | static int unpack_strdup(struct aa_ext *e, char **string, const char *name) | |
274 | { | |
275 | const char *tmp; | |
276 | void *pos = e->pos; | |
277 | int res = unpack_str(e, &tmp, name); | |
278 | *string = NULL; | |
279 | ||
280 | if (!res) | |
281 | return 0; | |
282 | ||
283 | *string = kmemdup(tmp, res, GFP_KERNEL); | |
284 | if (!*string) { | |
285 | e->pos = pos; | |
286 | return 0; | |
287 | } | |
288 | ||
289 | return res; | |
290 | } | |
291 | ||
180a6f59 JJ |
292 | #define DFA_VALID_PERM_MASK 0xffffffff |
293 | #define DFA_VALID_PERM2_MASK 0xffffffff | |
294 | ||
736ec752 JJ |
295 | /** |
296 | * verify_accept - verify the accept tables of a dfa | |
297 | * @dfa: dfa to verify accept tables of (NOT NULL) | |
298 | * @flags: flags governing dfa | |
299 | * | |
300 | * Returns: 1 if valid accept tables else 0 if error | |
301 | */ | |
302 | static bool verify_accept(struct aa_dfa *dfa, int flags) | |
303 | { | |
304 | int i; | |
305 | ||
306 | /* verify accept permissions */ | |
307 | for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) { | |
308 | int mode = ACCEPT_TABLE(dfa)[i]; | |
309 | ||
310 | if (mode & ~DFA_VALID_PERM_MASK) | |
311 | return 0; | |
312 | ||
313 | if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK) | |
314 | return 0; | |
315 | } | |
316 | return 1; | |
317 | } | |
318 | ||
319 | /** | |
320 | * unpack_dfa - unpack a file rule dfa | |
321 | * @e: serialized data extent information (NOT NULL) | |
322 | * | |
323 | * returns dfa or ERR_PTR or NULL if no dfa | |
324 | */ | |
325 | static struct aa_dfa *unpack_dfa(struct aa_ext *e) | |
326 | { | |
327 | char *blob = NULL; | |
328 | size_t size; | |
329 | struct aa_dfa *dfa = NULL; | |
330 | ||
331 | size = unpack_blob(e, &blob, "aadfa"); | |
332 | if (size) { | |
333 | /* | |
334 | * The dfa is aligned with in the blob to 8 bytes | |
335 | * from the beginning of the stream. | |
336 | */ | |
337 | size_t sz = blob - (char *)e->start; | |
338 | size_t pad = ALIGN(sz, 8) - sz; | |
339 | int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) | | |
340 | TO_ACCEPT2_FLAG(YYTD_DATA32); | |
341 | ||
342 | ||
343 | if (aa_g_paranoid_load) | |
344 | flags |= DFA_FLAG_VERIFY_STATES; | |
345 | ||
346 | dfa = aa_dfa_unpack(blob + pad, size - pad, flags); | |
347 | ||
348 | if (IS_ERR(dfa)) | |
349 | return dfa; | |
350 | ||
351 | if (!verify_accept(dfa, flags)) | |
352 | goto fail; | |
353 | } | |
354 | ||
355 | return dfa; | |
356 | ||
357 | fail: | |
358 | aa_put_dfa(dfa); | |
359 | return ERR_PTR(-EPROTO); | |
360 | } | |
361 | ||
362 | /** | |
363 | * unpack_trans_table - unpack a profile transition table | |
364 | * @e: serialized data extent information (NOT NULL) | |
365 | * @profile: profile to add the accept table to (NOT NULL) | |
366 | * | |
25985edc | 367 | * Returns: 1 if table successfully unpacked |
736ec752 JJ |
368 | */ |
369 | static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile) | |
370 | { | |
371 | void *pos = e->pos; | |
372 | ||
373 | /* exec table is optional */ | |
374 | if (unpack_nameX(e, AA_STRUCT, "xtable")) { | |
375 | int i, size; | |
376 | ||
377 | size = unpack_array(e, NULL); | |
378 | /* currently 4 exec bits and entries 0-3 are reserved iupcx */ | |
379 | if (size > 16 - 4) | |
380 | goto fail; | |
381 | profile->file.trans.table = kzalloc(sizeof(char *) * size, | |
382 | GFP_KERNEL); | |
383 | if (!profile->file.trans.table) | |
384 | goto fail; | |
385 | ||
386 | profile->file.trans.size = size; | |
387 | for (i = 0; i < size; i++) { | |
388 | char *str; | |
7ee95850 | 389 | int c, j, size2 = unpack_strdup(e, &str, NULL); |
736ec752 JJ |
390 | /* unpack_strdup verifies that the last character is |
391 | * null termination byte. | |
392 | */ | |
7ee95850 | 393 | if (!size2) |
736ec752 JJ |
394 | goto fail; |
395 | profile->file.trans.table[i] = str; | |
396 | /* verify that name doesn't start with space */ | |
397 | if (isspace(*str)) | |
398 | goto fail; | |
399 | ||
400 | /* count internal # of internal \0 */ | |
7ee95850 | 401 | for (c = j = 0; j < size2 - 2; j++) { |
736ec752 JJ |
402 | if (!str[j]) |
403 | c++; | |
404 | } | |
405 | if (*str == ':') { | |
406 | /* beginning with : requires an embedded \0, | |
407 | * verify that exactly 1 internal \0 exists | |
408 | * trailing \0 already verified by unpack_strdup | |
409 | */ | |
410 | if (c != 1) | |
411 | goto fail; | |
412 | /* first character after : must be valid */ | |
413 | if (!str[1]) | |
414 | goto fail; | |
415 | } else if (c) | |
416 | /* fail - all other cases with embedded \0 */ | |
417 | goto fail; | |
418 | } | |
419 | if (!unpack_nameX(e, AA_ARRAYEND, NULL)) | |
420 | goto fail; | |
421 | if (!unpack_nameX(e, AA_STRUCTEND, NULL)) | |
422 | goto fail; | |
423 | } | |
424 | return 1; | |
425 | ||
426 | fail: | |
427 | aa_free_domain_entries(&profile->file.trans); | |
428 | e->pos = pos; | |
429 | return 0; | |
430 | } | |
431 | ||
432 | static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile) | |
433 | { | |
434 | void *pos = e->pos; | |
435 | ||
436 | /* rlimits are optional */ | |
437 | if (unpack_nameX(e, AA_STRUCT, "rlimits")) { | |
438 | int i, size; | |
439 | u32 tmp = 0; | |
440 | if (!unpack_u32(e, &tmp, NULL)) | |
441 | goto fail; | |
442 | profile->rlimits.mask = tmp; | |
443 | ||
444 | size = unpack_array(e, NULL); | |
445 | if (size > RLIM_NLIMITS) | |
446 | goto fail; | |
447 | for (i = 0; i < size; i++) { | |
7ee95850 | 448 | u64 tmp2 = 0; |
736ec752 | 449 | int a = aa_map_resource(i); |
7ee95850 | 450 | if (!unpack_u64(e, &tmp2, NULL)) |
736ec752 | 451 | goto fail; |
7ee95850 | 452 | profile->rlimits.limits[a].rlim_max = tmp2; |
736ec752 JJ |
453 | } |
454 | if (!unpack_nameX(e, AA_ARRAYEND, NULL)) | |
455 | goto fail; | |
456 | if (!unpack_nameX(e, AA_STRUCTEND, NULL)) | |
457 | goto fail; | |
458 | } | |
459 | return 1; | |
460 | ||
461 | fail: | |
462 | e->pos = pos; | |
463 | return 0; | |
464 | } | |
465 | ||
466 | /** | |
467 | * unpack_profile - unpack a serialized profile | |
468 | * @e: serialized data extent information (NOT NULL) | |
469 | * | |
470 | * NOTE: unpack profile sets audit struct if there is a failure | |
471 | */ | |
472 | static struct aa_profile *unpack_profile(struct aa_ext *e) | |
473 | { | |
474 | struct aa_profile *profile = NULL; | |
475 | const char *name = NULL; | |
ad5ff3db | 476 | int i, error = -EPROTO; |
736ec752 JJ |
477 | kernel_cap_t tmpcap; |
478 | u32 tmp; | |
479 | ||
480 | /* check that we have the right struct being passed */ | |
481 | if (!unpack_nameX(e, AA_STRUCT, "profile")) | |
482 | goto fail; | |
483 | if (!unpack_str(e, &name, NULL)) | |
484 | goto fail; | |
485 | ||
486 | profile = aa_alloc_profile(name); | |
487 | if (!profile) | |
488 | return ERR_PTR(-ENOMEM); | |
489 | ||
490 | /* profile renaming is optional */ | |
491 | (void) unpack_str(e, &profile->rename, "rename"); | |
492 | ||
493 | /* xmatch is optional and may be NULL */ | |
494 | profile->xmatch = unpack_dfa(e); | |
495 | if (IS_ERR(profile->xmatch)) { | |
496 | error = PTR_ERR(profile->xmatch); | |
497 | profile->xmatch = NULL; | |
498 | goto fail; | |
499 | } | |
500 | /* xmatch_len is not optional if xmatch is set */ | |
501 | if (profile->xmatch) { | |
502 | if (!unpack_u32(e, &tmp, NULL)) | |
503 | goto fail; | |
504 | profile->xmatch_len = tmp; | |
505 | } | |
506 | ||
507 | /* per profile debug flags (complain, audit) */ | |
508 | if (!unpack_nameX(e, AA_STRUCT, "flags")) | |
509 | goto fail; | |
510 | if (!unpack_u32(e, &tmp, NULL)) | |
511 | goto fail; | |
512 | if (tmp) | |
513 | profile->flags |= PFLAG_HAT; | |
514 | if (!unpack_u32(e, &tmp, NULL)) | |
515 | goto fail; | |
516 | if (tmp) | |
517 | profile->mode = APPARMOR_COMPLAIN; | |
518 | if (!unpack_u32(e, &tmp, NULL)) | |
519 | goto fail; | |
520 | if (tmp) | |
521 | profile->audit = AUDIT_ALL; | |
522 | ||
523 | if (!unpack_nameX(e, AA_STRUCTEND, NULL)) | |
524 | goto fail; | |
525 | ||
526 | /* path_flags is optional */ | |
527 | if (unpack_u32(e, &profile->path_flags, "path_flags")) | |
528 | profile->path_flags |= profile->flags & PFLAG_MEDIATE_DELETED; | |
529 | else | |
530 | /* set a default value if path_flags field is not present */ | |
531 | profile->path_flags = PFLAG_MEDIATE_DELETED; | |
532 | ||
533 | if (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL)) | |
534 | goto fail; | |
535 | if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL)) | |
536 | goto fail; | |
537 | if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL)) | |
538 | goto fail; | |
539 | if (!unpack_u32(e, &tmpcap.cap[0], NULL)) | |
540 | goto fail; | |
541 | ||
542 | if (unpack_nameX(e, AA_STRUCT, "caps64")) { | |
543 | /* optional upper half of 64 bit caps */ | |
544 | if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL)) | |
545 | goto fail; | |
546 | if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL)) | |
547 | goto fail; | |
548 | if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL)) | |
549 | goto fail; | |
550 | if (!unpack_u32(e, &(tmpcap.cap[1]), NULL)) | |
551 | goto fail; | |
552 | if (!unpack_nameX(e, AA_STRUCTEND, NULL)) | |
553 | goto fail; | |
554 | } | |
555 | ||
556 | if (unpack_nameX(e, AA_STRUCT, "capsx")) { | |
557 | /* optional extended caps mediation mask */ | |
558 | if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL)) | |
559 | goto fail; | |
560 | if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL)) | |
561 | goto fail; | |
cdbd2884 JJ |
562 | if (!unpack_nameX(e, AA_STRUCTEND, NULL)) |
563 | goto fail; | |
736ec752 JJ |
564 | } |
565 | ||
566 | if (!unpack_rlimits(e, profile)) | |
567 | goto fail; | |
568 | ||
ad5ff3db JJ |
569 | if (unpack_nameX(e, AA_STRUCT, "policydb")) { |
570 | /* generic policy dfa - optional and may be NULL */ | |
571 | profile->policy.dfa = unpack_dfa(e); | |
572 | if (IS_ERR(profile->policy.dfa)) { | |
573 | error = PTR_ERR(profile->policy.dfa); | |
574 | profile->policy.dfa = NULL; | |
575 | goto fail; | |
576 | } | |
577 | if (!unpack_u32(e, &profile->policy.start[0], "start")) | |
578 | /* default start state */ | |
579 | profile->policy.start[0] = DFA_START; | |
580 | /* setup class index */ | |
581 | for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) { | |
582 | profile->policy.start[i] = | |
583 | aa_dfa_next(profile->policy.dfa, | |
584 | profile->policy.start[0], | |
585 | i); | |
586 | } | |
587 | if (!unpack_nameX(e, AA_STRUCTEND, NULL)) | |
588 | goto fail; | |
589 | } | |
590 | ||
736ec752 JJ |
591 | /* get file rules */ |
592 | profile->file.dfa = unpack_dfa(e); | |
593 | if (IS_ERR(profile->file.dfa)) { | |
594 | error = PTR_ERR(profile->file.dfa); | |
595 | profile->file.dfa = NULL; | |
596 | goto fail; | |
597 | } | |
598 | ||
599 | if (!unpack_u32(e, &profile->file.start, "dfa_start")) | |
600 | /* default start state */ | |
601 | profile->file.start = DFA_START; | |
602 | ||
603 | if (!unpack_trans_table(e, profile)) | |
604 | goto fail; | |
605 | ||
606 | if (!unpack_nameX(e, AA_STRUCTEND, NULL)) | |
607 | goto fail; | |
608 | ||
609 | return profile; | |
610 | ||
611 | fail: | |
612 | if (profile) | |
613 | name = NULL; | |
614 | else if (!name) | |
615 | name = "unknown"; | |
616 | audit_iface(profile, name, "failed to unpack profile", e, error); | |
617 | aa_put_profile(profile); | |
618 | ||
619 | return ERR_PTR(error); | |
620 | } | |
621 | ||
622 | /** | |
623 | * verify_head - unpack serialized stream header | |
624 | * @e: serialized data read head (NOT NULL) | |
625 | * @ns: Returns - namespace if one is specified else NULL (NOT NULL) | |
626 | * | |
627 | * Returns: error or 0 if header is good | |
628 | */ | |
629 | static int verify_header(struct aa_ext *e, const char **ns) | |
630 | { | |
631 | int error = -EPROTONOSUPPORT; | |
632 | /* get the interface version */ | |
633 | if (!unpack_u32(e, &e->version, "version")) { | |
634 | audit_iface(NULL, NULL, "invalid profile format", e, error); | |
635 | return error; | |
636 | } | |
637 | ||
638 | /* check that the interface version is currently supported */ | |
639 | if (e->version != 5) { | |
640 | audit_iface(NULL, NULL, "unsupported interface version", e, | |
641 | error); | |
642 | return error; | |
643 | } | |
644 | ||
645 | /* read the namespace if present */ | |
646 | if (!unpack_str(e, ns, "namespace")) | |
647 | *ns = NULL; | |
648 | ||
649 | return 0; | |
650 | } | |
651 | ||
652 | static bool verify_xindex(int xindex, int table_size) | |
653 | { | |
654 | int index, xtype; | |
655 | xtype = xindex & AA_X_TYPE_MASK; | |
656 | index = xindex & AA_X_INDEX_MASK; | |
657 | if (xtype == AA_X_TABLE && index > table_size) | |
658 | return 0; | |
659 | return 1; | |
660 | } | |
661 | ||
662 | /* verify dfa xindexes are in range of transition tables */ | |
663 | static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size) | |
664 | { | |
665 | int i; | |
666 | for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) { | |
667 | if (!verify_xindex(dfa_user_xindex(dfa, i), table_size)) | |
668 | return 0; | |
669 | if (!verify_xindex(dfa_other_xindex(dfa, i), table_size)) | |
670 | return 0; | |
671 | } | |
672 | return 1; | |
673 | } | |
674 | ||
675 | /** | |
676 | * verify_profile - Do post unpack analysis to verify profile consistency | |
677 | * @profile: profile to verify (NOT NULL) | |
678 | * | |
679 | * Returns: 0 if passes verification else error | |
680 | */ | |
681 | static int verify_profile(struct aa_profile *profile) | |
682 | { | |
683 | if (aa_g_paranoid_load) { | |
684 | if (profile->file.dfa && | |
685 | !verify_dfa_xindex(profile->file.dfa, | |
686 | profile->file.trans.size)) { | |
687 | audit_iface(profile, NULL, "Invalid named transition", | |
688 | NULL, -EPROTO); | |
689 | return -EPROTO; | |
690 | } | |
691 | } | |
692 | ||
693 | return 0; | |
694 | } | |
695 | ||
696 | /** | |
697 | * aa_unpack - unpack packed binary profile data loaded from user space | |
698 | * @udata: user data copied to kmem (NOT NULL) | |
699 | * @size: the size of the user data | |
700 | * @ns: Returns namespace profile is in if specified else NULL (NOT NULL) | |
701 | * | |
702 | * Unpack user data and return refcounted allocated profile or ERR_PTR | |
703 | * | |
704 | * Returns: profile else error pointer if fails to unpack | |
705 | */ | |
706 | struct aa_profile *aa_unpack(void *udata, size_t size, const char **ns) | |
707 | { | |
708 | struct aa_profile *profile = NULL; | |
709 | int error; | |
710 | struct aa_ext e = { | |
711 | .start = udata, | |
712 | .end = udata + size, | |
713 | .pos = udata, | |
714 | }; | |
715 | ||
716 | error = verify_header(&e, ns); | |
717 | if (error) | |
718 | return ERR_PTR(error); | |
719 | ||
720 | profile = unpack_profile(&e); | |
721 | if (IS_ERR(profile)) | |
722 | return profile; | |
723 | ||
724 | error = verify_profile(profile); | |
725 | if (error) { | |
726 | aa_put_profile(profile); | |
727 | profile = ERR_PTR(error); | |
728 | } | |
729 | ||
730 | /* return refcount */ | |
731 | return profile; | |
732 | } |