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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 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/match.h"
28#include "include/policy.h"
29#include "include/policy_unpack.h"
30#include "include/sid.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 (NOT NULL)
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 COMMON_AUDIT_DATA_INIT(&sa, NONE);
98 sa.aad.iface.pos = e->pos - e->start;
99 sa.aad.iface.target = new;
100 sa.aad.name = name;
101 sa.aad.info = info;
102 sa.aad.error = error;
103
104 return aa_audit(AUDIT_APPARMOR_STATUS, profile, GFP_KERNEL, &sa,
105 audit_cb);
106}
107
108/* test if read will be in packed data bounds */
109static bool inbounds(struct aa_ext *e, size_t size)
110{
111 return (size <= e->end - e->pos);
112}
113
114/**
115 * aa_u16_chunck - test and do bounds checking for a u16 size based chunk
116 * @e: serialized data read head (NOT NULL)
117 * @chunk: start address for chunk of data (NOT NULL)
118 *
119 * Returns: the size of chunk found with the read head at the end of the chunk.
120 */
121static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk)
122{
123 size_t size = 0;
124
125 if (!inbounds(e, sizeof(u16)))
126 return 0;
127 size = le16_to_cpu(get_unaligned((u16 *) e->pos));
128 e->pos += sizeof(u16);
129 if (!inbounds(e, size))
130 return 0;
131 *chunk = e->pos;
132 e->pos += size;
133 return size;
134}
135
136/* unpack control byte */
137static bool unpack_X(struct aa_ext *e, enum aa_code code)
138{
139 if (!inbounds(e, 1))
140 return 0;
141 if (*(u8 *) e->pos != code)
142 return 0;
143 e->pos++;
144 return 1;
145}
146
147/**
148 * unpack_nameX - check is the next element is of type X with a name of @name
149 * @e: serialized data extent information (NOT NULL)
150 * @code: type code
151 * @name: name to match to the serialized element. (MAYBE NULL)
152 *
153 * check that the next serialized data element is of type X and has a tag
154 * name @name. If @name is specified then there must be a matching
155 * name element in the stream. If @name is NULL any name element will be
156 * skipped and only the typecode will be tested.
157 *
158 * Returns 1 on success (both type code and name tests match) and the read
159 * head is advanced past the headers
160 *
161 * Returns: 0 if either match fails, the read head does not move
162 */
163static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
164{
165 /*
166 * May need to reset pos if name or type doesn't match
167 */
168 void *pos = e->pos;
169 /*
170 * Check for presence of a tagname, and if present name size
171 * AA_NAME tag value is a u16.
172 */
173 if (unpack_X(e, AA_NAME)) {
174 char *tag = NULL;
175 size_t size = unpack_u16_chunk(e, &tag);
176 /* if a name is specified it must match. otherwise skip tag */
177 if (name && (!size || strcmp(name, tag)))
178 goto fail;
179 } else if (name) {
180 /* if a name is specified and there is no name tag fail */
181 goto fail;
182 }
183
184 /* now check if type code matches */
185 if (unpack_X(e, code))
186 return 1;
187
188fail:
189 e->pos = pos;
190 return 0;
191}
192
193static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
194{
195 if (unpack_nameX(e, AA_U32, name)) {
196 if (!inbounds(e, sizeof(u32)))
197 return 0;
198 if (data)
199 *data = le32_to_cpu(get_unaligned((u32 *) e->pos));
200 e->pos += sizeof(u32);
201 return 1;
202 }
203 return 0;
204}
205
206static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name)
207{
208 if (unpack_nameX(e, AA_U64, name)) {
209 if (!inbounds(e, sizeof(u64)))
210 return 0;
211 if (data)
212 *data = le64_to_cpu(get_unaligned((u64 *) e->pos));
213 e->pos += sizeof(u64);
214 return 1;
215 }
216 return 0;
217}
218
219static size_t unpack_array(struct aa_ext *e, const char *name)
220{
221 if (unpack_nameX(e, AA_ARRAY, name)) {
222 int size;
223 if (!inbounds(e, sizeof(u16)))
224 return 0;
225 size = (int)le16_to_cpu(get_unaligned((u16 *) e->pos));
226 e->pos += sizeof(u16);
227 return size;
228 }
229 return 0;
230}
231
232static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
233{
234 if (unpack_nameX(e, AA_BLOB, name)) {
235 u32 size;
236 if (!inbounds(e, sizeof(u32)))
237 return 0;
238 size = le32_to_cpu(get_unaligned((u32 *) e->pos));
239 e->pos += sizeof(u32);
240 if (inbounds(e, (size_t) size)) {
241 *blob = e->pos;
242 e->pos += size;
243 return size;
244 }
245 }
246 return 0;
247}
248
249static int unpack_str(struct aa_ext *e, const char **string, const char *name)
250{
251 char *src_str;
252 size_t size = 0;
253 void *pos = e->pos;
254 *string = NULL;
255 if (unpack_nameX(e, AA_STRING, name)) {
256 size = unpack_u16_chunk(e, &src_str);
257 if (size) {
258 /* strings are null terminated, length is size - 1 */
259 if (src_str[size - 1] != 0)
260 goto fail;
261 *string = src_str;
262 }
263 }
264 return size;
265
266fail:
267 e->pos = pos;
268 return 0;
269}
270
271static int unpack_strdup(struct aa_ext *e, char **string, const char *name)
272{
273 const char *tmp;
274 void *pos = e->pos;
275 int res = unpack_str(e, &tmp, name);
276 *string = NULL;
277
278 if (!res)
279 return 0;
280
281 *string = kmemdup(tmp, res, GFP_KERNEL);
282 if (!*string) {
283 e->pos = pos;
284 return 0;
285 }
286
287 return res;
288}
289
290/**
291 * verify_accept - verify the accept tables of a dfa
292 * @dfa: dfa to verify accept tables of (NOT NULL)
293 * @flags: flags governing dfa
294 *
295 * Returns: 1 if valid accept tables else 0 if error
296 */
297static bool verify_accept(struct aa_dfa *dfa, int flags)
298{
299 int i;
300
301 /* verify accept permissions */
302 for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
303 int mode = ACCEPT_TABLE(dfa)[i];
304
305 if (mode & ~DFA_VALID_PERM_MASK)
306 return 0;
307
308 if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK)
309 return 0;
310 }
311 return 1;
312}
313
314/**
315 * unpack_dfa - unpack a file rule dfa
316 * @e: serialized data extent information (NOT NULL)
317 *
318 * returns dfa or ERR_PTR or NULL if no dfa
319 */
320static struct aa_dfa *unpack_dfa(struct aa_ext *e)
321{
322 char *blob = NULL;
323 size_t size;
324 struct aa_dfa *dfa = NULL;
325
326 size = unpack_blob(e, &blob, "aadfa");
327 if (size) {
328 /*
329 * The dfa is aligned with in the blob to 8 bytes
330 * from the beginning of the stream.
331 */
332 size_t sz = blob - (char *)e->start;
333 size_t pad = ALIGN(sz, 8) - sz;
334 int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) |
335 TO_ACCEPT2_FLAG(YYTD_DATA32);
336
337
338 if (aa_g_paranoid_load)
339 flags |= DFA_FLAG_VERIFY_STATES;
340
341 dfa = aa_dfa_unpack(blob + pad, size - pad, flags);
342
343 if (IS_ERR(dfa))
344 return dfa;
345
346 if (!verify_accept(dfa, flags))
347 goto fail;
348 }
349
350 return dfa;
351
352fail:
353 aa_put_dfa(dfa);
354 return ERR_PTR(-EPROTO);
355}
356
357/**
358 * unpack_trans_table - unpack a profile transition table
359 * @e: serialized data extent information (NOT NULL)
360 * @profile: profile to add the accept table to (NOT NULL)
361 *
362 * Returns: 1 if table successfully unpacked
363 */
364static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile)
365{
366 void *pos = e->pos;
367
368 /* exec table is optional */
369 if (unpack_nameX(e, AA_STRUCT, "xtable")) {
370 int i, size;
371
372 size = unpack_array(e, NULL);
373 /* currently 4 exec bits and entries 0-3 are reserved iupcx */
374 if (size > 16 - 4)
375 goto fail;
376 profile->file.trans.table = kzalloc(sizeof(char *) * size,
377 GFP_KERNEL);
378 if (!profile->file.trans.table)
379 goto fail;
380
381 profile->file.trans.size = size;
382 for (i = 0; i < size; i++) {
383 char *str;
384 int c, j, size = unpack_strdup(e, &str, NULL);
385 /* unpack_strdup verifies that the last character is
386 * null termination byte.
387 */
388 if (!size)
389 goto fail;
390 profile->file.trans.table[i] = str;
391 /* verify that name doesn't start with space */
392 if (isspace(*str))
393 goto fail;
394
395 /* count internal # of internal \0 */
396 for (c = j = 0; j < size - 2; j++) {
397 if (!str[j])
398 c++;
399 }
400 if (*str == ':') {
401 /* beginning with : requires an embedded \0,
402 * verify that exactly 1 internal \0 exists
403 * trailing \0 already verified by unpack_strdup
404 */
405 if (c != 1)
406 goto fail;
407 /* first character after : must be valid */
408 if (!str[1])
409 goto fail;
410 } else if (c)
411 /* fail - all other cases with embedded \0 */
412 goto fail;
413 }
414 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
415 goto fail;
416 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
417 goto fail;
418 }
419 return 1;
420
421fail:
422 aa_free_domain_entries(&profile->file.trans);
423 e->pos = pos;
424 return 0;
425}
426
427static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile)
428{
429 void *pos = e->pos;
430
431 /* rlimits are optional */
432 if (unpack_nameX(e, AA_STRUCT, "rlimits")) {
433 int i, size;
434 u32 tmp = 0;
435 if (!unpack_u32(e, &tmp, NULL))
436 goto fail;
437 profile->rlimits.mask = tmp;
438
439 size = unpack_array(e, NULL);
440 if (size > RLIM_NLIMITS)
441 goto fail;
442 for (i = 0; i < size; i++) {
443 u64 tmp = 0;
444 int a = aa_map_resource(i);
445 if (!unpack_u64(e, &tmp, NULL))
446 goto fail;
447 profile->rlimits.limits[a].rlim_max = tmp;
448 }
449 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
450 goto fail;
451 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
452 goto fail;
453 }
454 return 1;
455
456fail:
457 e->pos = pos;
458 return 0;
459}
460
461/**
462 * unpack_profile - unpack a serialized profile
463 * @e: serialized data extent information (NOT NULL)
464 *
465 * NOTE: unpack profile sets audit struct if there is a failure
466 */
467static struct aa_profile *unpack_profile(struct aa_ext *e)
468{
469 struct aa_profile *profile = NULL;
470 const char *name = NULL;
471 int error = -EPROTO;
472 kernel_cap_t tmpcap;
473 u32 tmp;
474
475 /* check that we have the right struct being passed */
476 if (!unpack_nameX(e, AA_STRUCT, "profile"))
477 goto fail;
478 if (!unpack_str(e, &name, NULL))
479 goto fail;
480
481 profile = aa_alloc_profile(name);
482 if (!profile)
483 return ERR_PTR(-ENOMEM);
484
485 /* profile renaming is optional */
486 (void) unpack_str(e, &profile->rename, "rename");
487
488 /* xmatch is optional and may be NULL */
489 profile->xmatch = unpack_dfa(e);
490 if (IS_ERR(profile->xmatch)) {
491 error = PTR_ERR(profile->xmatch);
492 profile->xmatch = NULL;
493 goto fail;
494 }
495 /* xmatch_len is not optional if xmatch is set */
496 if (profile->xmatch) {
497 if (!unpack_u32(e, &tmp, NULL))
498 goto fail;
499 profile->xmatch_len = tmp;
500 }
501
502 /* per profile debug flags (complain, audit) */
503 if (!unpack_nameX(e, AA_STRUCT, "flags"))
504 goto fail;
505 if (!unpack_u32(e, &tmp, NULL))
506 goto fail;
507 if (tmp)
508 profile->flags |= PFLAG_HAT;
509 if (!unpack_u32(e, &tmp, NULL))
510 goto fail;
511 if (tmp)
512 profile->mode = APPARMOR_COMPLAIN;
513 if (!unpack_u32(e, &tmp, NULL))
514 goto fail;
515 if (tmp)
516 profile->audit = AUDIT_ALL;
517
518 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
519 goto fail;
520
521 /* path_flags is optional */
522 if (unpack_u32(e, &profile->path_flags, "path_flags"))
523 profile->path_flags |= profile->flags & PFLAG_MEDIATE_DELETED;
524 else
525 /* set a default value if path_flags field is not present */
526 profile->path_flags = PFLAG_MEDIATE_DELETED;
527
528 if (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL))
529 goto fail;
530 if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL))
531 goto fail;
532 if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL))
533 goto fail;
534 if (!unpack_u32(e, &tmpcap.cap[0], NULL))
535 goto fail;
536
537 if (unpack_nameX(e, AA_STRUCT, "caps64")) {
538 /* optional upper half of 64 bit caps */
539 if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL))
540 goto fail;
541 if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL))
542 goto fail;
543 if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL))
544 goto fail;
545 if (!unpack_u32(e, &(tmpcap.cap[1]), NULL))
546 goto fail;
547 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
548 goto fail;
549 }
550
551 if (unpack_nameX(e, AA_STRUCT, "capsx")) {
552 /* optional extended caps mediation mask */
553 if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL))
554 goto fail;
555 if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL))
556 goto fail;
557 }
558
559 if (!unpack_rlimits(e, profile))
560 goto fail;
561
562 /* get file rules */
563 profile->file.dfa = unpack_dfa(e);
564 if (IS_ERR(profile->file.dfa)) {
565 error = PTR_ERR(profile->file.dfa);
566 profile->file.dfa = NULL;
567 goto fail;
568 }
569
570 if (!unpack_u32(e, &profile->file.start, "dfa_start"))
571 /* default start state */
572 profile->file.start = DFA_START;
573
574 if (!unpack_trans_table(e, profile))
575 goto fail;
576
577 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
578 goto fail;
579
580 return profile;
581
582fail:
583 if (profile)
584 name = NULL;
585 else if (!name)
586 name = "unknown";
587 audit_iface(profile, name, "failed to unpack profile", e, error);
588 aa_put_profile(profile);
589
590 return ERR_PTR(error);
591}
592
593/**
594 * verify_head - unpack serialized stream header
595 * @e: serialized data read head (NOT NULL)
596 * @ns: Returns - namespace if one is specified else NULL (NOT NULL)
597 *
598 * Returns: error or 0 if header is good
599 */
600static int verify_header(struct aa_ext *e, const char **ns)
601{
602 int error = -EPROTONOSUPPORT;
603 /* get the interface version */
604 if (!unpack_u32(e, &e->version, "version")) {
605 audit_iface(NULL, NULL, "invalid profile format", e, error);
606 return error;
607 }
608
609 /* check that the interface version is currently supported */
610 if (e->version != 5) {
611 audit_iface(NULL, NULL, "unsupported interface version", e,
612 error);
613 return error;
614 }
615
616 /* read the namespace if present */
617 if (!unpack_str(e, ns, "namespace"))
618 *ns = NULL;
619
620 return 0;
621}
622
623static bool verify_xindex(int xindex, int table_size)
624{
625 int index, xtype;
626 xtype = xindex & AA_X_TYPE_MASK;
627 index = xindex & AA_X_INDEX_MASK;
628 if (xtype == AA_X_TABLE && index > table_size)
629 return 0;
630 return 1;
631}
632
633/* verify dfa xindexes are in range of transition tables */
634static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size)
635{
636 int i;
637 for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
638 if (!verify_xindex(dfa_user_xindex(dfa, i), table_size))
639 return 0;
640 if (!verify_xindex(dfa_other_xindex(dfa, i), table_size))
641 return 0;
642 }
643 return 1;
644}
645
646/**
647 * verify_profile - Do post unpack analysis to verify profile consistency
648 * @profile: profile to verify (NOT NULL)
649 *
650 * Returns: 0 if passes verification else error
651 */
652static int verify_profile(struct aa_profile *profile)
653{
654 if (aa_g_paranoid_load) {
655 if (profile->file.dfa &&
656 !verify_dfa_xindex(profile->file.dfa,
657 profile->file.trans.size)) {
658 audit_iface(profile, NULL, "Invalid named transition",
659 NULL, -EPROTO);
660 return -EPROTO;
661 }
662 }
663
664 return 0;
665}
666
667/**
668 * aa_unpack - unpack packed binary profile data loaded from user space
669 * @udata: user data copied to kmem (NOT NULL)
670 * @size: the size of the user data
671 * @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
672 *
673 * Unpack user data and return refcounted allocated profile or ERR_PTR
674 *
675 * Returns: profile else error pointer if fails to unpack
676 */
677struct aa_profile *aa_unpack(void *udata, size_t size, const char **ns)
678{
679 struct aa_profile *profile = NULL;
680 int error;
681 struct aa_ext e = {
682 .start = udata,
683 .end = udata + size,
684 .pos = udata,
685 };
686
687 error = verify_header(&e, ns);
688 if (error)
689 return ERR_PTR(error);
690
691 profile = unpack_profile(&e);
692 if (IS_ERR(profile))
693 return profile;
694
695 error = verify_profile(profile);
696 if (error) {
697 aa_put_profile(profile);
698 profile = ERR_PTR(error);
699 }
700
701 /* return refcount */
702 return profile;
703}
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 }
587 if (!unpack_u32(e, &profile->policy.start[0], "start"))
588 /* default start state */
589 profile->policy.start[0] = DFA_START;
590 /* setup class index */
591 for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) {
592 profile->policy.start[i] =
593 aa_dfa_next(profile->policy.dfa,
594 profile->policy.start[0],
595 i);
596 }
597 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
598 goto fail;
599 }
600
601 /* get file rules */
602 profile->file.dfa = unpack_dfa(e);
603 if (IS_ERR(profile->file.dfa)) {
604 error = PTR_ERR(profile->file.dfa);
605 profile->file.dfa = NULL;
606 goto fail;
607 }
608
609 if (!unpack_u32(e, &profile->file.start, "dfa_start"))
610 /* default start state */
611 profile->file.start = DFA_START;
612
613 if (!unpack_trans_table(e, profile))
614 goto fail;
615
616 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
617 goto fail;
618
619 return profile;
620
621fail:
622 if (profile)
623 name = NULL;
624 else if (!name)
625 name = "unknown";
626 audit_iface(profile, name, "failed to unpack profile", e, error);
627 aa_free_profile(profile);
628
629 return ERR_PTR(error);
630}
631
632/**
633 * verify_head - unpack serialized stream header
634 * @e: serialized data read head (NOT NULL)
635 * @required: whether the header is required or optional
636 * @ns: Returns - namespace if one is specified else NULL (NOT NULL)
637 *
638 * Returns: error or 0 if header is good
639 */
640static int verify_header(struct aa_ext *e, int required, const char **ns)
641{
642 int error = -EPROTONOSUPPORT;
643 const char *name = NULL;
644 *ns = NULL;
645
646 /* get the interface version */
647 if (!unpack_u32(e, &e->version, "version")) {
648 if (required) {
649 audit_iface(NULL, NULL, "invalid profile format", e,
650 error);
651 return error;
652 }
653
654 /* check that the interface version is currently supported */
655 if (e->version != 5) {
656 audit_iface(NULL, NULL, "unsupported interface version",
657 e, error);
658 return error;
659 }
660 }
661
662
663 /* read the namespace if present */
664 if (unpack_str(e, &name, "namespace")) {
665 if (*ns && strcmp(*ns, name))
666 audit_iface(NULL, NULL, "invalid ns change", e, error);
667 else if (!*ns)
668 *ns = name;
669 }
670
671 return 0;
672}
673
674static bool verify_xindex(int xindex, int table_size)
675{
676 int index, xtype;
677 xtype = xindex & AA_X_TYPE_MASK;
678 index = xindex & AA_X_INDEX_MASK;
679 if (xtype == AA_X_TABLE && index > table_size)
680 return 0;
681 return 1;
682}
683
684/* verify dfa xindexes are in range of transition tables */
685static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size)
686{
687 int i;
688 for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
689 if (!verify_xindex(dfa_user_xindex(dfa, i), table_size))
690 return 0;
691 if (!verify_xindex(dfa_other_xindex(dfa, i), table_size))
692 return 0;
693 }
694 return 1;
695}
696
697/**
698 * verify_profile - Do post unpack analysis to verify profile consistency
699 * @profile: profile to verify (NOT NULL)
700 *
701 * Returns: 0 if passes verification else error
702 */
703static int verify_profile(struct aa_profile *profile)
704{
705 if (aa_g_paranoid_load) {
706 if (profile->file.dfa &&
707 !verify_dfa_xindex(profile->file.dfa,
708 profile->file.trans.size)) {
709 audit_iface(profile, NULL, "Invalid named transition",
710 NULL, -EPROTO);
711 return -EPROTO;
712 }
713 }
714
715 return 0;
716}
717
718void aa_load_ent_free(struct aa_load_ent *ent)
719{
720 if (ent) {
721 aa_put_profile(ent->rename);
722 aa_put_profile(ent->old);
723 aa_put_profile(ent->new);
724 kzfree(ent);
725 }
726}
727
728struct aa_load_ent *aa_load_ent_alloc(void)
729{
730 struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL);
731 if (ent)
732 INIT_LIST_HEAD(&ent->list);
733 return ent;
734}
735
736/**
737 * aa_unpack - unpack packed binary profile(s) data loaded from user space
738 * @udata: user data copied to kmem (NOT NULL)
739 * @size: the size of the user data
740 * @lh: list to place unpacked profiles in a aa_repl_ws
741 * @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
742 *
743 * Unpack user data and return refcounted allocated profile(s) stored in
744 * @lh in order of discovery, with the list chain stored in base.list
745 * or error
746 *
747 * Returns: profile(s) on @lh else error pointer if fails to unpack
748 */
749int aa_unpack(void *udata, size_t size, struct list_head *lh, const char **ns)
750{
751 struct aa_load_ent *tmp, *ent;
752 struct aa_profile *profile = NULL;
753 int error;
754 struct aa_ext e = {
755 .start = udata,
756 .end = udata + size,
757 .pos = udata,
758 };
759
760 *ns = NULL;
761 while (e.pos < e.end) {
762 void *start;
763 error = verify_header(&e, e.pos == e.start, ns);
764 if (error)
765 goto fail;
766
767 start = e.pos;
768 profile = unpack_profile(&e);
769 if (IS_ERR(profile)) {
770 error = PTR_ERR(profile);
771 goto fail;
772 }
773
774 error = verify_profile(profile);
775 if (error)
776 goto fail_profile;
777
778 error = aa_calc_profile_hash(profile, e.version, start,
779 e.pos - start);
780 if (error)
781 goto fail_profile;
782
783 ent = aa_load_ent_alloc();
784 if (!ent) {
785 error = -ENOMEM;
786 goto fail_profile;
787 }
788
789 ent->new = profile;
790 list_add_tail(&ent->list, lh);
791 }
792
793 return 0;
794
795fail_profile:
796 aa_put_profile(profile);
797
798fail:
799 list_for_each_entry_safe(ent, tmp, lh, list) {
800 list_del_init(&ent->list);
801 aa_load_ent_free(ent);
802 }
803
804 return error;
805}