policydb.c 37.4 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
/*
 * Implementation of the policy database.
 *
 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
 */

/*
 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
 *
 *	Support for enhanced MLS infrastructure.
 *
 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
 *
 * 	Added conditional policy language extensions
 *
 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
 * Copyright (C) 2003 - 2004 Tresys Technology, LLC
 *	This program is free software; you can redistribute it and/or modify
 *  	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation, version 2.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/errno.h>
#include "security.h"

#include "policydb.h"
#include "conditional.h"
#include "mls.h"

#define _DEBUG_HASHES

#ifdef DEBUG_HASHES
static char *symtab_name[SYM_NUM] = {
	"common prefixes",
	"classes",
	"roles",
	"types",
	"users",
	"bools",
	"levels",
	"categories",
};
#endif

int selinux_mls_enabled = 0;

static unsigned int symtab_sizes[SYM_NUM] = {
	2,
	32,
	16,
	512,
	128,
	16,
	16,
	16,
};

struct policydb_compat_info {
	int version;
	int sym_num;
	int ocon_num;
};

/* These need to be updated if SYM_NUM or OCON_NUM changes */
static struct policydb_compat_info policydb_compat[] = {
	{
		.version        = POLICYDB_VERSION_BASE,
		.sym_num        = SYM_NUM - 3,
		.ocon_num       = OCON_NUM - 1,
	},
	{
		.version        = POLICYDB_VERSION_BOOL,
		.sym_num        = SYM_NUM - 2,
		.ocon_num       = OCON_NUM - 1,
	},
	{
		.version        = POLICYDB_VERSION_IPV6,
		.sym_num        = SYM_NUM - 2,
		.ocon_num       = OCON_NUM,
	},
	{
		.version        = POLICYDB_VERSION_NLCLASS,
		.sym_num        = SYM_NUM - 2,
		.ocon_num       = OCON_NUM,
	},
	{
		.version        = POLICYDB_VERSION_MLS,
		.sym_num        = SYM_NUM,
		.ocon_num       = OCON_NUM,
	},
94
95
96
97
98
	{
		.version        = POLICYDB_VERSION_AVTAB,
		.sym_num        = SYM_NUM,
		.ocon_num       = OCON_NUM,
	},
Linus Torvalds's avatar
Linus Torvalds committed
99
100
101
102
103
104
105
};

static struct policydb_compat_info *policydb_lookup_compat(int version)
{
	int i;
	struct policydb_compat_info *info = NULL;

106
	for (i = 0; i < ARRAY_SIZE(policydb_compat); i++) {
Linus Torvalds's avatar
Linus Torvalds committed
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
		if (policydb_compat[i].version == version) {
			info = &policydb_compat[i];
			break;
		}
	}
	return info;
}

/*
 * Initialize the role table.
 */
static int roles_init(struct policydb *p)
{
	char *key = NULL;
	int rc;
	struct role_datum *role;

124
	role = kzalloc(sizeof(*role), GFP_KERNEL);
Linus Torvalds's avatar
Linus Torvalds committed
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
	if (!role) {
		rc = -ENOMEM;
		goto out;
	}
	role->value = ++p->p_roles.nprim;
	if (role->value != OBJECT_R_VAL) {
		rc = -EINVAL;
		goto out_free_role;
	}
	key = kmalloc(strlen(OBJECT_R)+1,GFP_KERNEL);
	if (!key) {
		rc = -ENOMEM;
		goto out_free_role;
	}
	strcpy(key, OBJECT_R);
	rc = hashtab_insert(p->p_roles.table, key, role);
	if (rc)
		goto out_free_key;
out:
	return rc;

out_free_key:
	kfree(key);
out_free_role:
	kfree(role);
	goto out;
}

/*
 * Initialize a policy database structure.
 */
static int policydb_init(struct policydb *p)
{
	int i, rc;

	memset(p, 0, sizeof(*p));

	for (i = 0; i < SYM_NUM; i++) {
		rc = symtab_init(&p->symtab[i], symtab_sizes[i]);
		if (rc)
			goto out_free_symtab;
	}

	rc = avtab_init(&p->te_avtab);
	if (rc)
		goto out_free_symtab;

	rc = roles_init(p);
	if (rc)
		goto out_free_avtab;

	rc = cond_policydb_init(p);
	if (rc)
		goto out_free_avtab;

out:
	return rc;

out_free_avtab:
	avtab_destroy(&p->te_avtab);

out_free_symtab:
	for (i = 0; i < SYM_NUM; i++)
		hashtab_destroy(p->symtab[i].table);
	goto out;
}

/*
 * The following *_index functions are used to
 * define the val_to_name and val_to_struct arrays
 * in a policy database structure.  The val_to_name
 * arrays are used when converting security context
 * structures into string representations.  The
 * val_to_struct arrays are used when the attributes
 * of a class, role, or user are needed.
 */

static int common_index(void *key, void *datum, void *datap)
{
	struct policydb *p;
	struct common_datum *comdatum;

	comdatum = datum;
	p = datap;
	if (!comdatum->value || comdatum->value > p->p_commons.nprim)
		return -EINVAL;
	p->p_common_val_to_name[comdatum->value - 1] = key;
	return 0;
}

static int class_index(void *key, void *datum, void *datap)
{
	struct policydb *p;
	struct class_datum *cladatum;

	cladatum = datum;
	p = datap;
	if (!cladatum->value || cladatum->value > p->p_classes.nprim)
		return -EINVAL;
	p->p_class_val_to_name[cladatum->value - 1] = key;
	p->class_val_to_struct[cladatum->value - 1] = cladatum;
	return 0;
}

static int role_index(void *key, void *datum, void *datap)
{
	struct policydb *p;
	struct role_datum *role;

	role = datum;
	p = datap;
	if (!role->value || role->value > p->p_roles.nprim)
		return -EINVAL;
	p->p_role_val_to_name[role->value - 1] = key;
	p->role_val_to_struct[role->value - 1] = role;
	return 0;
}

static int type_index(void *key, void *datum, void *datap)
{
	struct policydb *p;
	struct type_datum *typdatum;

	typdatum = datum;
	p = datap;

	if (typdatum->primary) {
		if (!typdatum->value || typdatum->value > p->p_types.nprim)
			return -EINVAL;
		p->p_type_val_to_name[typdatum->value - 1] = key;
	}

	return 0;
}

static int user_index(void *key, void *datum, void *datap)
{
	struct policydb *p;
	struct user_datum *usrdatum;

	usrdatum = datum;
	p = datap;
	if (!usrdatum->value || usrdatum->value > p->p_users.nprim)
		return -EINVAL;
	p->p_user_val_to_name[usrdatum->value - 1] = key;
	p->user_val_to_struct[usrdatum->value - 1] = usrdatum;
	return 0;
}

static int sens_index(void *key, void *datum, void *datap)
{
	struct policydb *p;
	struct level_datum *levdatum;

	levdatum = datum;
	p = datap;

	if (!levdatum->isalias) {
		if (!levdatum->level->sens ||
		    levdatum->level->sens > p->p_levels.nprim)
			return -EINVAL;
		p->p_sens_val_to_name[levdatum->level->sens - 1] = key;
	}

	return 0;
}

static int cat_index(void *key, void *datum, void *datap)
{
	struct policydb *p;
	struct cat_datum *catdatum;

	catdatum = datum;
	p = datap;

	if (!catdatum->isalias) {
		if (!catdatum->value || catdatum->value > p->p_cats.nprim)
			return -EINVAL;
		p->p_cat_val_to_name[catdatum->value - 1] = key;
	}

	return 0;
}

static int (*index_f[SYM_NUM]) (void *key, void *datum, void *datap) =
{
	common_index,
	class_index,
	role_index,
	type_index,
	user_index,
	cond_index_bool,
	sens_index,
	cat_index,
};

/*
 * Define the common val_to_name array and the class
 * val_to_name and val_to_struct arrays in a policy
 * database structure.
 *
 * Caller must clean up upon failure.
 */
static int policydb_index_classes(struct policydb *p)
{
	int rc;

	p->p_common_val_to_name =
		kmalloc(p->p_commons.nprim * sizeof(char *), GFP_KERNEL);
	if (!p->p_common_val_to_name) {
		rc = -ENOMEM;
		goto out;
	}

	rc = hashtab_map(p->p_commons.table, common_index, p);
	if (rc)
		goto out;

	p->class_val_to_struct =
		kmalloc(p->p_classes.nprim * sizeof(*(p->class_val_to_struct)), GFP_KERNEL);
	if (!p->class_val_to_struct) {
		rc = -ENOMEM;
		goto out;
	}

	p->p_class_val_to_name =
		kmalloc(p->p_classes.nprim * sizeof(char *), GFP_KERNEL);
	if (!p->p_class_val_to_name) {
		rc = -ENOMEM;
		goto out;
	}

	rc = hashtab_map(p->p_classes.table, class_index, p);
out:
	return rc;
}

#ifdef DEBUG_HASHES
static void symtab_hash_eval(struct symtab *s)
{
	int i;

	for (i = 0; i < SYM_NUM; i++) {
		struct hashtab *h = s[i].table;
		struct hashtab_info info;

		hashtab_stat(h, &info);
		printk(KERN_INFO "%s:  %d entries and %d/%d buckets used, "
		       "longest chain length %d\n", symtab_name[i], h->nel,
		       info.slots_used, h->size, info.max_chain_len);
	}
}
#endif

/*
 * Define the other val_to_name and val_to_struct arrays
 * in a policy database structure.
 *
 * Caller must clean up on failure.
 */
static int policydb_index_others(struct policydb *p)
{
	int i, rc = 0;

	printk(KERN_INFO "security:  %d users, %d roles, %d types, %d bools",
	       p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim, p->p_bools.nprim);
	if (selinux_mls_enabled)
		printk(", %d sens, %d cats", p->p_levels.nprim,
		       p->p_cats.nprim);
	printk("\n");

	printk(KERN_INFO "security:  %d classes, %d rules\n",
	       p->p_classes.nprim, p->te_avtab.nel);

#ifdef DEBUG_HASHES
	avtab_hash_eval(&p->te_avtab, "rules");
	symtab_hash_eval(p->symtab);
#endif

	p->role_val_to_struct =
		kmalloc(p->p_roles.nprim * sizeof(*(p->role_val_to_struct)),
		        GFP_KERNEL);
	if (!p->role_val_to_struct) {
		rc = -ENOMEM;
		goto out;
	}

	p->user_val_to_struct =
		kmalloc(p->p_users.nprim * sizeof(*(p->user_val_to_struct)),
		        GFP_KERNEL);
	if (!p->user_val_to_struct) {
		rc = -ENOMEM;
		goto out;
	}

	if (cond_init_bool_indexes(p)) {
		rc = -ENOMEM;
		goto out;
	}

	for (i = SYM_ROLES; i < SYM_NUM; i++) {
		p->sym_val_to_name[i] =
			kmalloc(p->symtab[i].nprim * sizeof(char *), GFP_KERNEL);
		if (!p->sym_val_to_name[i]) {
			rc = -ENOMEM;
			goto out;
		}
		rc = hashtab_map(p->symtab[i].table, index_f[i], p);
		if (rc)
			goto out;
	}

out:
	return rc;
}

/*
 * The following *_destroy functions are used to
 * free any memory allocated for each kind of
 * symbol data in the policy database.
 */

static int perm_destroy(void *key, void *datum, void *p)
{
	kfree(key);
	kfree(datum);
	return 0;
}

static int common_destroy(void *key, void *datum, void *p)
{
	struct common_datum *comdatum;

	kfree(key);
	comdatum = datum;
	hashtab_map(comdatum->permissions.table, perm_destroy, NULL);
	hashtab_destroy(comdatum->permissions.table);
	kfree(datum);
	return 0;
}

static int class_destroy(void *key, void *datum, void *p)
{
	struct class_datum *cladatum;
	struct constraint_node *constraint, *ctemp;
	struct constraint_expr *e, *etmp;

	kfree(key);
	cladatum = datum;
	hashtab_map(cladatum->permissions.table, perm_destroy, NULL);
	hashtab_destroy(cladatum->permissions.table);
	constraint = cladatum->constraints;
	while (constraint) {
		e = constraint->expr;
		while (e) {
			ebitmap_destroy(&e->names);
			etmp = e;
			e = e->next;
			kfree(etmp);
		}
		ctemp = constraint;
		constraint = constraint->next;
		kfree(ctemp);
	}

	constraint = cladatum->validatetrans;
	while (constraint) {
		e = constraint->expr;
		while (e) {
			ebitmap_destroy(&e->names);
			etmp = e;
			e = e->next;
			kfree(etmp);
		}
		ctemp = constraint;
		constraint = constraint->next;
		kfree(ctemp);
	}

	kfree(cladatum->comkey);
	kfree(datum);
	return 0;
}

static int role_destroy(void *key, void *datum, void *p)
{
	struct role_datum *role;

	kfree(key);
	role = datum;
	ebitmap_destroy(&role->dominates);
	ebitmap_destroy(&role->types);
	kfree(datum);
	return 0;
}

static int type_destroy(void *key, void *datum, void *p)
{
	kfree(key);
	kfree(datum);
	return 0;
}

static int user_destroy(void *key, void *datum, void *p)
{
	struct user_datum *usrdatum;

	kfree(key);
	usrdatum = datum;
	ebitmap_destroy(&usrdatum->roles);
	ebitmap_destroy(&usrdatum->range.level[0].cat);
	ebitmap_destroy(&usrdatum->range.level[1].cat);
	ebitmap_destroy(&usrdatum->dfltlevel.cat);
	kfree(datum);
	return 0;
}

static int sens_destroy(void *key, void *datum, void *p)
{
	struct level_datum *levdatum;

	kfree(key);
	levdatum = datum;
	ebitmap_destroy(&levdatum->level->cat);
	kfree(levdatum->level);
	kfree(datum);
	return 0;
}

static int cat_destroy(void *key, void *datum, void *p)
{
	kfree(key);
	kfree(datum);
	return 0;
}

static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) =
{
	common_destroy,
	class_destroy,
	role_destroy,
	type_destroy,
	user_destroy,
	cond_destroy_bool,
	sens_destroy,
	cat_destroy,
};

static void ocontext_destroy(struct ocontext *c, int i)
{
	context_destroy(&c->context[0]);
	context_destroy(&c->context[1]);
	if (i == OCON_ISID || i == OCON_FS ||
	    i == OCON_NETIF || i == OCON_FSUSE)
		kfree(c->u.name);
	kfree(c);
}

/*
 * Free any memory allocated by a policy database structure.
 */
void policydb_destroy(struct policydb *p)
{
	struct ocontext *c, *ctmp;
	struct genfs *g, *gtmp;
	int i;
591
592
593
	struct role_allow *ra, *lra = NULL;
	struct role_trans *tr, *ltr = NULL;
	struct range_trans *rt, *lrt = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
594
595
596
597
598
599

	for (i = 0; i < SYM_NUM; i++) {
		hashtab_map(p->symtab[i].table, destroy_f[i], NULL);
		hashtab_destroy(p->symtab[i].table);
	}

Jesper Juhl's avatar
Jesper Juhl committed
600
601
	for (i = 0; i < SYM_NUM; i++)
		kfree(p->sym_val_to_name[i]);
Linus Torvalds's avatar
Linus Torvalds committed
602

Jesper Juhl's avatar
Jesper Juhl committed
603
604
605
	kfree(p->class_val_to_struct);
	kfree(p->role_val_to_struct);
	kfree(p->user_val_to_struct);
Linus Torvalds's avatar
Linus Torvalds committed
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633

	avtab_destroy(&p->te_avtab);

	for (i = 0; i < OCON_NUM; i++) {
		c = p->ocontexts[i];
		while (c) {
			ctmp = c;
			c = c->next;
			ocontext_destroy(ctmp,i);
		}
	}

	g = p->genfs;
	while (g) {
		kfree(g->fstype);
		c = g->head;
		while (c) {
			ctmp = c;
			c = c->next;
			ocontext_destroy(ctmp,OCON_FSUSE);
		}
		gtmp = g;
		g = g->next;
		kfree(gtmp);
	}

	cond_policydb_destroy(p);

634
	for (tr = p->role_tr; tr; tr = tr->next) {
Jesper Juhl's avatar
Jesper Juhl committed
635
		kfree(ltr);
636
637
		ltr = tr;
	}
Jesper Juhl's avatar
Jesper Juhl committed
638
	kfree(ltr);
639
640

	for (ra = p->role_allow; ra; ra = ra -> next) {
Jesper Juhl's avatar
Jesper Juhl committed
641
		kfree(lra);
642
643
		lra = ra;
	}
Jesper Juhl's avatar
Jesper Juhl committed
644
	kfree(lra);
645
646

	for (rt = p->range_tr; rt; rt = rt -> next) {
Jesper Juhl's avatar
Jesper Juhl committed
647
		kfree(lrt);
648
649
		lrt = rt;
	}
Jesper Juhl's avatar
Jesper Juhl committed
650
	kfree(lrt);
651

652
653
654
655
	if (p->type_attr_map) {
		for (i = 0; i < p->p_types.nprim; i++)
			ebitmap_destroy(&p->type_attr_map[i]);
	}
656
657
	kfree(p->type_attr_map);

Linus Torvalds's avatar
Linus Torvalds committed
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
	return;
}

/*
 * Load the initial SIDs specified in a policy database
 * structure into a SID table.
 */
int policydb_load_isids(struct policydb *p, struct sidtab *s)
{
	struct ocontext *head, *c;
	int rc;

	rc = sidtab_init(s);
	if (rc) {
		printk(KERN_ERR "security:  out of memory on SID table init\n");
		goto out;
	}

	head = p->ocontexts[OCON_ISID];
	for (c = head; c; c = c->next) {
		if (!c->context[0].user) {
			printk(KERN_ERR "security:  SID %s was never "
			       "defined.\n", c->u.name);
			rc = -EINVAL;
			goto out;
		}
		if (sidtab_insert(s, c->sid[0], &c->context[0])) {
			printk(KERN_ERR "security:  unable to load initial "
			       "SID %s.\n", c->u.name);
			rc = -EINVAL;
			goto out;
		}
	}
out:
	return rc;
}

/*
 * Return 1 if the fields in the security context
 * structure `c' are valid.  Return 0 otherwise.
 */
int policydb_context_isvalid(struct policydb *p, struct context *c)
{
	struct role_datum *role;
	struct user_datum *usrdatum;

	if (!c->role || c->role > p->p_roles.nprim)
		return 0;

	if (!c->user || c->user > p->p_users.nprim)
		return 0;

	if (!c->type || c->type > p->p_types.nprim)
		return 0;

	if (c->role != OBJECT_R_VAL) {
		/*
		 * Role must be authorized for the type.
		 */
		role = p->role_val_to_struct[c->role - 1];
		if (!ebitmap_get_bit(&role->types,
				     c->type - 1))
			/* role may not be associated with type */
			return 0;

		/*
		 * User must be authorized for the role.
		 */
		usrdatum = p->user_val_to_struct[c->user - 1];
		if (!usrdatum)
			return 0;

		if (!ebitmap_get_bit(&usrdatum->roles,
				     c->role - 1))
			/* user may not be associated with role */
			return 0;
	}

	if (!mls_context_isvalid(p, c))
		return 0;

	return 1;
}

/*
 * Read a MLS range structure from a policydb binary
 * representation file.
 */
static int mls_read_range_helper(struct mls_range *r, void *fp)
{
748
749
	__le32 buf[2];
	u32 items;
Linus Torvalds's avatar
Linus Torvalds committed
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
	int rc;

	rc = next_entry(buf, fp, sizeof(u32));
	if (rc < 0)
		goto out;

	items = le32_to_cpu(buf[0]);
	if (items > ARRAY_SIZE(buf)) {
		printk(KERN_ERR "security: mls:  range overflow\n");
		rc = -EINVAL;
		goto out;
	}
	rc = next_entry(buf, fp, sizeof(u32) * items);
	if (rc < 0) {
		printk(KERN_ERR "security: mls:  truncated range\n");
		goto out;
	}
	r->level[0].sens = le32_to_cpu(buf[0]);
	if (items > 1)
		r->level[1].sens = le32_to_cpu(buf[1]);
	else
		r->level[1].sens = r->level[0].sens;

	rc = ebitmap_read(&r->level[0].cat, fp);
	if (rc) {
		printk(KERN_ERR "security: mls:  error reading low "
		       "categories\n");
		goto out;
	}
	if (items > 1) {
		rc = ebitmap_read(&r->level[1].cat, fp);
		if (rc) {
			printk(KERN_ERR "security: mls:  error reading high "
			       "categories\n");
			goto bad_high;
		}
	} else {
		rc = ebitmap_cpy(&r->level[1].cat, &r->level[0].cat);
		if (rc) {
			printk(KERN_ERR "security: mls:  out of memory\n");
			goto bad_high;
		}
	}

	rc = 0;
out:
	return rc;
bad_high:
	ebitmap_destroy(&r->level[0].cat);
	goto out;
}

/*
 * Read and validate a security context structure
 * from a policydb binary representation file.
 */
static int context_read_and_validate(struct context *c,
				     struct policydb *p,
				     void *fp)
{
810
	__le32 buf[3];
Linus Torvalds's avatar
Linus Torvalds committed
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
	int rc;

	rc = next_entry(buf, fp, sizeof buf);
	if (rc < 0) {
		printk(KERN_ERR "security: context truncated\n");
		goto out;
	}
	c->user = le32_to_cpu(buf[0]);
	c->role = le32_to_cpu(buf[1]);
	c->type = le32_to_cpu(buf[2]);
	if (p->policyvers >= POLICYDB_VERSION_MLS) {
		if (mls_read_range_helper(&c->range, fp)) {
			printk(KERN_ERR "security: error reading MLS range of "
			       "context\n");
			rc = -EINVAL;
			goto out;
		}
	}

	if (!policydb_context_isvalid(p, c)) {
		printk(KERN_ERR "security:  invalid security context\n");
		context_destroy(c);
		rc = -EINVAL;
	}
out:
	return rc;
}

/*
 * The following *_read functions are used to
 * read the symbol data from a policy database
 * binary representation file.
 */

static int perm_read(struct policydb *p, struct hashtab *h, void *fp)
{
	char *key = NULL;
	struct perm_datum *perdatum;
	int rc;
850
851
	__le32 buf[2];
	u32 len;
Linus Torvalds's avatar
Linus Torvalds committed
852

853
	perdatum = kzalloc(sizeof(*perdatum), GFP_KERNEL);
Linus Torvalds's avatar
Linus Torvalds committed
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
	if (!perdatum) {
		rc = -ENOMEM;
		goto out;
	}

	rc = next_entry(buf, fp, sizeof buf);
	if (rc < 0)
		goto bad;

	len = le32_to_cpu(buf[0]);
	perdatum->value = le32_to_cpu(buf[1]);

	key = kmalloc(len + 1,GFP_KERNEL);
	if (!key) {
		rc = -ENOMEM;
		goto bad;
	}
	rc = next_entry(key, fp, len);
	if (rc < 0)
		goto bad;
	key[len] = 0;

	rc = hashtab_insert(h, key, perdatum);
	if (rc)
		goto bad;
out:
	return rc;
bad:
	perm_destroy(key, perdatum, NULL);
	goto out;
}

static int common_read(struct policydb *p, struct hashtab *h, void *fp)
{
	char *key = NULL;
	struct common_datum *comdatum;
890
891
	__le32 buf[4];
	u32 len, nel;
Linus Torvalds's avatar
Linus Torvalds committed
892
893
	int i, rc;

894
	comdatum = kzalloc(sizeof(*comdatum), GFP_KERNEL);
Linus Torvalds's avatar
Linus Torvalds committed
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
	if (!comdatum) {
		rc = -ENOMEM;
		goto out;
	}

	rc = next_entry(buf, fp, sizeof buf);
	if (rc < 0)
		goto bad;

	len = le32_to_cpu(buf[0]);
	comdatum->value = le32_to_cpu(buf[1]);

	rc = symtab_init(&comdatum->permissions, PERM_SYMTAB_SIZE);
	if (rc)
		goto bad;
	comdatum->permissions.nprim = le32_to_cpu(buf[2]);
	nel = le32_to_cpu(buf[3]);

	key = kmalloc(len + 1,GFP_KERNEL);
	if (!key) {
		rc = -ENOMEM;
		goto bad;
	}
	rc = next_entry(key, fp, len);
	if (rc < 0)
		goto bad;
	key[len] = 0;

	for (i = 0; i < nel; i++) {
		rc = perm_read(p, comdatum->permissions.table, fp);
		if (rc)
			goto bad;
	}

	rc = hashtab_insert(h, key, comdatum);
	if (rc)
		goto bad;
out:
	return rc;
bad:
	common_destroy(key, comdatum, NULL);
	goto out;
}

static int read_cons_helper(struct constraint_node **nodep, int ncons,
                            int allowxtarget, void *fp)
{
	struct constraint_node *c, *lc;
	struct constraint_expr *e, *le;
944
945
	__le32 buf[3];
	u32 nexpr;
Linus Torvalds's avatar
Linus Torvalds committed
946
947
948
949
	int rc, i, j, depth;

	lc = NULL;
	for (i = 0; i < ncons; i++) {
950
		c = kzalloc(sizeof(*c), GFP_KERNEL);
Linus Torvalds's avatar
Linus Torvalds committed
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
		if (!c)
			return -ENOMEM;

		if (lc) {
			lc->next = c;
		} else {
			*nodep = c;
		}

		rc = next_entry(buf, fp, (sizeof(u32) * 2));
		if (rc < 0)
			return rc;
		c->permissions = le32_to_cpu(buf[0]);
		nexpr = le32_to_cpu(buf[1]);
		le = NULL;
		depth = -1;
		for (j = 0; j < nexpr; j++) {
968
			e = kzalloc(sizeof(*e), GFP_KERNEL);
Linus Torvalds's avatar
Linus Torvalds committed
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
			if (!e)
				return -ENOMEM;

			if (le) {
				le->next = e;
			} else {
				c->expr = e;
			}

			rc = next_entry(buf, fp, (sizeof(u32) * 3));
			if (rc < 0)
				return rc;
			e->expr_type = le32_to_cpu(buf[0]);
			e->attr = le32_to_cpu(buf[1]);
			e->op = le32_to_cpu(buf[2]);

			switch (e->expr_type) {
			case CEXPR_NOT:
				if (depth < 0)
					return -EINVAL;
				break;
			case CEXPR_AND:
			case CEXPR_OR:
				if (depth < 1)
					return -EINVAL;
				depth--;
				break;
			case CEXPR_ATTR:
				if (depth == (CEXPR_MAXDEPTH - 1))
					return -EINVAL;
				depth++;
				break;
For faster browsing, not all history is shown. View entire blame