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1 /*
2  * Implementation of the security services.
3  *
4  * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5  *	     James Morris <jmorris@redhat.com>
6  *
7  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8  *
9  *	Support for enhanced MLS infrastructure.
10  *	Support for context based audit filters.
11  *
12  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13  *
14  *	Added conditional policy language extensions
15  *
16  * Updated: Hewlett-Packard <paul@paul-moore.com>
17  *
18  *      Added support for NetLabel
19  *      Added support for the policy capability bitmap
20  *
21  * Updated: Chad Sellers <csellers@tresys.com>
22  *
23  *  Added validation of kernel classes and permissions
24  *
25  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26  *
27  *  Added support for bounds domain and audit messaged on masked permissions
28  *
29  * Updated: Guido Trentalancia <guido@trentalancia.com>
30  *
31  *  Added support for runtime switching of the policy type
32  *
33  * Copyright (C) 2008, 2009 NEC Corporation
34  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38  *	This program is free software; you can redistribute it and/or modify
39  *	it under the terms of the GNU General Public License as published by
40  *	the Free Software Foundation, version 2.
41  */
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
44 #include <linux/string.h>
45 #include <linux/spinlock.h>
46 #include <linux/rcupdate.h>
47 #include <linux/errno.h>
48 #include <linux/in.h>
49 #include <linux/sched.h>
50 #include <linux/audit.h>
51 #include <linux/mutex.h>
52 #include <linux/selinux.h>
53 #include <linux/flex_array.h>
54 #include <linux/vmalloc.h>
55 #include <net/netlabel.h>
56 
57 #include "flask.h"
58 #include "avc.h"
59 #include "avc_ss.h"
60 #include "security.h"
61 #include "context.h"
62 #include "policydb.h"
63 #include "sidtab.h"
64 #include "services.h"
65 #include "conditional.h"
66 #include "mls.h"
67 #include "objsec.h"
68 #include "netlabel.h"
69 #include "xfrm.h"
70 #include "ebitmap.h"
71 #include "audit.h"
72 
73 int selinux_policycap_netpeer;
74 int selinux_policycap_openperm;
75 
76 static DEFINE_RWLOCK(policy_rwlock);
77 
78 static struct sidtab sidtab;
79 struct policydb policydb;
80 int ss_initialized;
81 
82 /*
83  * The largest sequence number that has been used when
84  * providing an access decision to the access vector cache.
85  * The sequence number only changes when a policy change
86  * occurs.
87  */
88 static u32 latest_granting;
89 
90 /* Forward declaration. */
91 static int context_struct_to_string(struct context *context, char **scontext,
92 				    u32 *scontext_len);
93 
94 static void context_struct_compute_av(struct context *scontext,
95 					struct context *tcontext,
96 					u16 tclass,
97 					struct av_decision *avd,
98 					struct extended_perms *xperms);
99 
100 struct selinux_mapping {
101 	u16 value; /* policy value */
102 	unsigned num_perms;
103 	u32 perms[sizeof(u32) * 8];
104 };
105 
106 static struct selinux_mapping *current_mapping;
107 static u16 current_mapping_size;
108 
selinux_set_mapping(struct policydb * pol,struct security_class_mapping * map,struct selinux_mapping ** out_map_p,u16 * out_map_size)109 static int selinux_set_mapping(struct policydb *pol,
110 			       struct security_class_mapping *map,
111 			       struct selinux_mapping **out_map_p,
112 			       u16 *out_map_size)
113 {
114 	struct selinux_mapping *out_map = NULL;
115 	size_t size = sizeof(struct selinux_mapping);
116 	u16 i, j;
117 	unsigned k;
118 	bool print_unknown_handle = false;
119 
120 	/* Find number of classes in the input mapping */
121 	if (!map)
122 		return -EINVAL;
123 	i = 0;
124 	while (map[i].name)
125 		i++;
126 
127 	/* Allocate space for the class records, plus one for class zero */
128 	out_map = kcalloc(++i, size, GFP_ATOMIC);
129 	if (!out_map)
130 		return -ENOMEM;
131 
132 	/* Store the raw class and permission values */
133 	j = 0;
134 	while (map[j].name) {
135 		struct security_class_mapping *p_in = map + (j++);
136 		struct selinux_mapping *p_out = out_map + j;
137 
138 		/* An empty class string skips ahead */
139 		if (!strcmp(p_in->name, "")) {
140 			p_out->num_perms = 0;
141 			continue;
142 		}
143 
144 		p_out->value = string_to_security_class(pol, p_in->name);
145 		if (!p_out->value) {
146 			printk(KERN_INFO
147 			       "SELinux:  Class %s not defined in policy.\n",
148 			       p_in->name);
149 			if (pol->reject_unknown)
150 				goto err;
151 			p_out->num_perms = 0;
152 			print_unknown_handle = true;
153 			continue;
154 		}
155 
156 		k = 0;
157 		while (p_in->perms && p_in->perms[k]) {
158 			/* An empty permission string skips ahead */
159 			if (!*p_in->perms[k]) {
160 				k++;
161 				continue;
162 			}
163 			p_out->perms[k] = string_to_av_perm(pol, p_out->value,
164 							    p_in->perms[k]);
165 			if (!p_out->perms[k]) {
166 				printk(KERN_INFO
167 				       "SELinux:  Permission %s in class %s not defined in policy.\n",
168 				       p_in->perms[k], p_in->name);
169 				if (pol->reject_unknown)
170 					goto err;
171 				print_unknown_handle = true;
172 			}
173 
174 			k++;
175 		}
176 		p_out->num_perms = k;
177 	}
178 
179 	if (print_unknown_handle)
180 		printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
181 		       pol->allow_unknown ? "allowed" : "denied");
182 
183 	*out_map_p = out_map;
184 	*out_map_size = i;
185 	return 0;
186 err:
187 	kfree(out_map);
188 	return -EINVAL;
189 }
190 
191 /*
192  * Get real, policy values from mapped values
193  */
194 
unmap_class(u16 tclass)195 static u16 unmap_class(u16 tclass)
196 {
197 	if (tclass < current_mapping_size)
198 		return current_mapping[tclass].value;
199 
200 	return tclass;
201 }
202 
203 /*
204  * Get kernel value for class from its policy value
205  */
map_class(u16 pol_value)206 static u16 map_class(u16 pol_value)
207 {
208 	u16 i;
209 
210 	for (i = 1; i < current_mapping_size; i++) {
211 		if (current_mapping[i].value == pol_value)
212 			return i;
213 	}
214 
215 	return SECCLASS_NULL;
216 }
217 
map_decision(u16 tclass,struct av_decision * avd,int allow_unknown)218 static void map_decision(u16 tclass, struct av_decision *avd,
219 			 int allow_unknown)
220 {
221 	if (tclass < current_mapping_size) {
222 		unsigned i, n = current_mapping[tclass].num_perms;
223 		u32 result;
224 
225 		for (i = 0, result = 0; i < n; i++) {
226 			if (avd->allowed & current_mapping[tclass].perms[i])
227 				result |= 1<<i;
228 			if (allow_unknown && !current_mapping[tclass].perms[i])
229 				result |= 1<<i;
230 		}
231 		avd->allowed = result;
232 
233 		for (i = 0, result = 0; i < n; i++)
234 			if (avd->auditallow & current_mapping[tclass].perms[i])
235 				result |= 1<<i;
236 		avd->auditallow = result;
237 
238 		for (i = 0, result = 0; i < n; i++) {
239 			if (avd->auditdeny & current_mapping[tclass].perms[i])
240 				result |= 1<<i;
241 			if (!allow_unknown && !current_mapping[tclass].perms[i])
242 				result |= 1<<i;
243 		}
244 		/*
245 		 * In case the kernel has a bug and requests a permission
246 		 * between num_perms and the maximum permission number, we
247 		 * should audit that denial
248 		 */
249 		for (; i < (sizeof(u32)*8); i++)
250 			result |= 1<<i;
251 		avd->auditdeny = result;
252 	}
253 }
254 
security_mls_enabled(void)255 int security_mls_enabled(void)
256 {
257 	return policydb.mls_enabled;
258 }
259 
260 /*
261  * Return the boolean value of a constraint expression
262  * when it is applied to the specified source and target
263  * security contexts.
264  *
265  * xcontext is a special beast...  It is used by the validatetrans rules
266  * only.  For these rules, scontext is the context before the transition,
267  * tcontext is the context after the transition, and xcontext is the context
268  * of the process performing the transition.  All other callers of
269  * constraint_expr_eval should pass in NULL for xcontext.
270  */
constraint_expr_eval(struct context * scontext,struct context * tcontext,struct context * xcontext,struct constraint_expr * cexpr)271 static int constraint_expr_eval(struct context *scontext,
272 				struct context *tcontext,
273 				struct context *xcontext,
274 				struct constraint_expr *cexpr)
275 {
276 	u32 val1, val2;
277 	struct context *c;
278 	struct role_datum *r1, *r2;
279 	struct mls_level *l1, *l2;
280 	struct constraint_expr *e;
281 	int s[CEXPR_MAXDEPTH];
282 	int sp = -1;
283 
284 	for (e = cexpr; e; e = e->next) {
285 		switch (e->expr_type) {
286 		case CEXPR_NOT:
287 			BUG_ON(sp < 0);
288 			s[sp] = !s[sp];
289 			break;
290 		case CEXPR_AND:
291 			BUG_ON(sp < 1);
292 			sp--;
293 			s[sp] &= s[sp + 1];
294 			break;
295 		case CEXPR_OR:
296 			BUG_ON(sp < 1);
297 			sp--;
298 			s[sp] |= s[sp + 1];
299 			break;
300 		case CEXPR_ATTR:
301 			if (sp == (CEXPR_MAXDEPTH - 1))
302 				return 0;
303 			switch (e->attr) {
304 			case CEXPR_USER:
305 				val1 = scontext->user;
306 				val2 = tcontext->user;
307 				break;
308 			case CEXPR_TYPE:
309 				val1 = scontext->type;
310 				val2 = tcontext->type;
311 				break;
312 			case CEXPR_ROLE:
313 				val1 = scontext->role;
314 				val2 = tcontext->role;
315 				r1 = policydb.role_val_to_struct[val1 - 1];
316 				r2 = policydb.role_val_to_struct[val2 - 1];
317 				switch (e->op) {
318 				case CEXPR_DOM:
319 					s[++sp] = ebitmap_get_bit(&r1->dominates,
320 								  val2 - 1);
321 					continue;
322 				case CEXPR_DOMBY:
323 					s[++sp] = ebitmap_get_bit(&r2->dominates,
324 								  val1 - 1);
325 					continue;
326 				case CEXPR_INCOMP:
327 					s[++sp] = (!ebitmap_get_bit(&r1->dominates,
328 								    val2 - 1) &&
329 						   !ebitmap_get_bit(&r2->dominates,
330 								    val1 - 1));
331 					continue;
332 				default:
333 					break;
334 				}
335 				break;
336 			case CEXPR_L1L2:
337 				l1 = &(scontext->range.level[0]);
338 				l2 = &(tcontext->range.level[0]);
339 				goto mls_ops;
340 			case CEXPR_L1H2:
341 				l1 = &(scontext->range.level[0]);
342 				l2 = &(tcontext->range.level[1]);
343 				goto mls_ops;
344 			case CEXPR_H1L2:
345 				l1 = &(scontext->range.level[1]);
346 				l2 = &(tcontext->range.level[0]);
347 				goto mls_ops;
348 			case CEXPR_H1H2:
349 				l1 = &(scontext->range.level[1]);
350 				l2 = &(tcontext->range.level[1]);
351 				goto mls_ops;
352 			case CEXPR_L1H1:
353 				l1 = &(scontext->range.level[0]);
354 				l2 = &(scontext->range.level[1]);
355 				goto mls_ops;
356 			case CEXPR_L2H2:
357 				l1 = &(tcontext->range.level[0]);
358 				l2 = &(tcontext->range.level[1]);
359 				goto mls_ops;
360 mls_ops:
361 			switch (e->op) {
362 			case CEXPR_EQ:
363 				s[++sp] = mls_level_eq(l1, l2);
364 				continue;
365 			case CEXPR_NEQ:
366 				s[++sp] = !mls_level_eq(l1, l2);
367 				continue;
368 			case CEXPR_DOM:
369 				s[++sp] = mls_level_dom(l1, l2);
370 				continue;
371 			case CEXPR_DOMBY:
372 				s[++sp] = mls_level_dom(l2, l1);
373 				continue;
374 			case CEXPR_INCOMP:
375 				s[++sp] = mls_level_incomp(l2, l1);
376 				continue;
377 			default:
378 				BUG();
379 				return 0;
380 			}
381 			break;
382 			default:
383 				BUG();
384 				return 0;
385 			}
386 
387 			switch (e->op) {
388 			case CEXPR_EQ:
389 				s[++sp] = (val1 == val2);
390 				break;
391 			case CEXPR_NEQ:
392 				s[++sp] = (val1 != val2);
393 				break;
394 			default:
395 				BUG();
396 				return 0;
397 			}
398 			break;
399 		case CEXPR_NAMES:
400 			if (sp == (CEXPR_MAXDEPTH-1))
401 				return 0;
402 			c = scontext;
403 			if (e->attr & CEXPR_TARGET)
404 				c = tcontext;
405 			else if (e->attr & CEXPR_XTARGET) {
406 				c = xcontext;
407 				if (!c) {
408 					BUG();
409 					return 0;
410 				}
411 			}
412 			if (e->attr & CEXPR_USER)
413 				val1 = c->user;
414 			else if (e->attr & CEXPR_ROLE)
415 				val1 = c->role;
416 			else if (e->attr & CEXPR_TYPE)
417 				val1 = c->type;
418 			else {
419 				BUG();
420 				return 0;
421 			}
422 
423 			switch (e->op) {
424 			case CEXPR_EQ:
425 				s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
426 				break;
427 			case CEXPR_NEQ:
428 				s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
429 				break;
430 			default:
431 				BUG();
432 				return 0;
433 			}
434 			break;
435 		default:
436 			BUG();
437 			return 0;
438 		}
439 	}
440 
441 	BUG_ON(sp != 0);
442 	return s[0];
443 }
444 
445 /*
446  * security_dump_masked_av - dumps masked permissions during
447  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
448  */
dump_masked_av_helper(void * k,void * d,void * args)449 static int dump_masked_av_helper(void *k, void *d, void *args)
450 {
451 	struct perm_datum *pdatum = d;
452 	char **permission_names = args;
453 
454 	BUG_ON(pdatum->value < 1 || pdatum->value > 32);
455 
456 	permission_names[pdatum->value - 1] = (char *)k;
457 
458 	return 0;
459 }
460 
security_dump_masked_av(struct context * scontext,struct context * tcontext,u16 tclass,u32 permissions,const char * reason)461 static void security_dump_masked_av(struct context *scontext,
462 				    struct context *tcontext,
463 				    u16 tclass,
464 				    u32 permissions,
465 				    const char *reason)
466 {
467 	struct common_datum *common_dat;
468 	struct class_datum *tclass_dat;
469 	struct audit_buffer *ab;
470 	char *tclass_name;
471 	char *scontext_name = NULL;
472 	char *tcontext_name = NULL;
473 	char *permission_names[32];
474 	int index;
475 	u32 length;
476 	bool need_comma = false;
477 
478 	if (!permissions)
479 		return;
480 
481 	tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
482 	tclass_dat = policydb.class_val_to_struct[tclass - 1];
483 	common_dat = tclass_dat->comdatum;
484 
485 	/* init permission_names */
486 	if (common_dat &&
487 	    hashtab_map(common_dat->permissions.table,
488 			dump_masked_av_helper, permission_names) < 0)
489 		goto out;
490 
491 	if (hashtab_map(tclass_dat->permissions.table,
492 			dump_masked_av_helper, permission_names) < 0)
493 		goto out;
494 
495 	/* get scontext/tcontext in text form */
496 	if (context_struct_to_string(scontext,
497 				     &scontext_name, &length) < 0)
498 		goto out;
499 
500 	if (context_struct_to_string(tcontext,
501 				     &tcontext_name, &length) < 0)
502 		goto out;
503 
504 	/* audit a message */
505 	ab = audit_log_start(current->audit_context,
506 			     GFP_ATOMIC, AUDIT_SELINUX_ERR);
507 	if (!ab)
508 		goto out;
509 
510 	audit_log_format(ab, "op=security_compute_av reason=%s "
511 			 "scontext=%s tcontext=%s tclass=%s perms=",
512 			 reason, scontext_name, tcontext_name, tclass_name);
513 
514 	for (index = 0; index < 32; index++) {
515 		u32 mask = (1 << index);
516 
517 		if ((mask & permissions) == 0)
518 			continue;
519 
520 		audit_log_format(ab, "%s%s",
521 				 need_comma ? "," : "",
522 				 permission_names[index]
523 				 ? permission_names[index] : "????");
524 		need_comma = true;
525 	}
526 	audit_log_end(ab);
527 out:
528 	/* release scontext/tcontext */
529 	kfree(tcontext_name);
530 	kfree(scontext_name);
531 
532 	return;
533 }
534 
535 /*
536  * security_boundary_permission - drops violated permissions
537  * on boundary constraint.
538  */
type_attribute_bounds_av(struct context * scontext,struct context * tcontext,u16 tclass,struct av_decision * avd)539 static void type_attribute_bounds_av(struct context *scontext,
540 				     struct context *tcontext,
541 				     u16 tclass,
542 				     struct av_decision *avd)
543 {
544 	struct context lo_scontext;
545 	struct context lo_tcontext;
546 	struct av_decision lo_avd;
547 	struct type_datum *source;
548 	struct type_datum *target;
549 	u32 masked = 0;
550 
551 	source = flex_array_get_ptr(policydb.type_val_to_struct_array,
552 				    scontext->type - 1);
553 	BUG_ON(!source);
554 
555 	target = flex_array_get_ptr(policydb.type_val_to_struct_array,
556 				    tcontext->type - 1);
557 	BUG_ON(!target);
558 
559 	if (source->bounds) {
560 		memset(&lo_avd, 0, sizeof(lo_avd));
561 
562 		memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
563 		lo_scontext.type = source->bounds;
564 
565 		context_struct_compute_av(&lo_scontext,
566 					  tcontext,
567 					  tclass,
568 					  &lo_avd,
569 					  NULL);
570 		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
571 			return;		/* no masked permission */
572 		masked = ~lo_avd.allowed & avd->allowed;
573 	}
574 
575 	if (target->bounds) {
576 		memset(&lo_avd, 0, sizeof(lo_avd));
577 
578 		memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
579 		lo_tcontext.type = target->bounds;
580 
581 		context_struct_compute_av(scontext,
582 					  &lo_tcontext,
583 					  tclass,
584 					  &lo_avd,
585 					  NULL);
586 		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
587 			return;		/* no masked permission */
588 		masked = ~lo_avd.allowed & avd->allowed;
589 	}
590 
591 	if (source->bounds && target->bounds) {
592 		memset(&lo_avd, 0, sizeof(lo_avd));
593 		/*
594 		 * lo_scontext and lo_tcontext are already
595 		 * set up.
596 		 */
597 
598 		context_struct_compute_av(&lo_scontext,
599 					  &lo_tcontext,
600 					  tclass,
601 					  &lo_avd,
602 					  NULL);
603 		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
604 			return;		/* no masked permission */
605 		masked = ~lo_avd.allowed & avd->allowed;
606 	}
607 
608 	if (masked) {
609 		/* mask violated permissions */
610 		avd->allowed &= ~masked;
611 
612 		/* audit masked permissions */
613 		security_dump_masked_av(scontext, tcontext,
614 					tclass, masked, "bounds");
615 	}
616 }
617 
618 /*
619  * flag which drivers have permissions
620  * only looking for ioctl based extended permssions
621  */
services_compute_xperms_drivers(struct extended_perms * xperms,struct avtab_node * node)622 void services_compute_xperms_drivers(
623 		struct extended_perms *xperms,
624 		struct avtab_node *node)
625 {
626 	unsigned int i;
627 
628 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
629 		/* if one or more driver has all permissions allowed */
630 		for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
631 			xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
632 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
633 		/* if allowing permissions within a driver */
634 		security_xperm_set(xperms->drivers.p,
635 					node->datum.u.xperms->driver);
636 	}
637 
638 	/* If no ioctl commands are allowed, ignore auditallow and auditdeny */
639 	if (node->key.specified & AVTAB_XPERMS_ALLOWED)
640 		xperms->len = 1;
641 }
642 
643 /*
644  * Compute access vectors and extended permissions based on a context
645  * structure pair for the permissions in a particular class.
646  */
context_struct_compute_av(struct context * scontext,struct context * tcontext,u16 tclass,struct av_decision * avd,struct extended_perms * xperms)647 static void context_struct_compute_av(struct context *scontext,
648 					struct context *tcontext,
649 					u16 tclass,
650 					struct av_decision *avd,
651 					struct extended_perms *xperms)
652 {
653 	struct constraint_node *constraint;
654 	struct role_allow *ra;
655 	struct avtab_key avkey;
656 	struct avtab_node *node;
657 	struct class_datum *tclass_datum;
658 	struct ebitmap *sattr, *tattr;
659 	struct ebitmap_node *snode, *tnode;
660 	unsigned int i, j;
661 
662 	avd->allowed = 0;
663 	avd->auditallow = 0;
664 	avd->auditdeny = 0xffffffff;
665 	if (xperms) {
666 		memset(&xperms->drivers, 0, sizeof(xperms->drivers));
667 		xperms->len = 0;
668 	}
669 
670 	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
671 		if (printk_ratelimit())
672 			printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
673 		return;
674 	}
675 
676 	tclass_datum = policydb.class_val_to_struct[tclass - 1];
677 
678 	/*
679 	 * If a specific type enforcement rule was defined for
680 	 * this permission check, then use it.
681 	 */
682 	avkey.target_class = tclass;
683 	avkey.specified = AVTAB_AV | AVTAB_XPERMS;
684 	sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
685 	BUG_ON(!sattr);
686 	tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
687 	BUG_ON(!tattr);
688 	ebitmap_for_each_positive_bit(sattr, snode, i) {
689 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
690 			avkey.source_type = i + 1;
691 			avkey.target_type = j + 1;
692 			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
693 			     node;
694 			     node = avtab_search_node_next(node, avkey.specified)) {
695 				if (node->key.specified == AVTAB_ALLOWED)
696 					avd->allowed |= node->datum.u.data;
697 				else if (node->key.specified == AVTAB_AUDITALLOW)
698 					avd->auditallow |= node->datum.u.data;
699 				else if (node->key.specified == AVTAB_AUDITDENY)
700 					avd->auditdeny &= node->datum.u.data;
701 				else if (xperms && (node->key.specified & AVTAB_XPERMS))
702 					services_compute_xperms_drivers(xperms, node);
703 			}
704 
705 			/* Check conditional av table for additional permissions */
706 			cond_compute_av(&policydb.te_cond_avtab, &avkey,
707 					avd, xperms);
708 
709 		}
710 	}
711 
712 	/*
713 	 * Remove any permissions prohibited by a constraint (this includes
714 	 * the MLS policy).
715 	 */
716 	constraint = tclass_datum->constraints;
717 	while (constraint) {
718 		if ((constraint->permissions & (avd->allowed)) &&
719 		    !constraint_expr_eval(scontext, tcontext, NULL,
720 					  constraint->expr)) {
721 			avd->allowed &= ~(constraint->permissions);
722 		}
723 		constraint = constraint->next;
724 	}
725 
726 	/*
727 	 * If checking process transition permission and the
728 	 * role is changing, then check the (current_role, new_role)
729 	 * pair.
730 	 */
731 	if (tclass == policydb.process_class &&
732 	    (avd->allowed & policydb.process_trans_perms) &&
733 	    scontext->role != tcontext->role) {
734 		for (ra = policydb.role_allow; ra; ra = ra->next) {
735 			if (scontext->role == ra->role &&
736 			    tcontext->role == ra->new_role)
737 				break;
738 		}
739 		if (!ra)
740 			avd->allowed &= ~policydb.process_trans_perms;
741 	}
742 
743 	/*
744 	 * If the given source and target types have boundary
745 	 * constraint, lazy checks have to mask any violated
746 	 * permission and notice it to userspace via audit.
747 	 */
748 	type_attribute_bounds_av(scontext, tcontext,
749 				 tclass, avd);
750 }
751 
security_validtrans_handle_fail(struct context * ocontext,struct context * ncontext,struct context * tcontext,u16 tclass)752 static int security_validtrans_handle_fail(struct context *ocontext,
753 					   struct context *ncontext,
754 					   struct context *tcontext,
755 					   u16 tclass)
756 {
757 	char *o = NULL, *n = NULL, *t = NULL;
758 	u32 olen, nlen, tlen;
759 
760 	if (context_struct_to_string(ocontext, &o, &olen))
761 		goto out;
762 	if (context_struct_to_string(ncontext, &n, &nlen))
763 		goto out;
764 	if (context_struct_to_string(tcontext, &t, &tlen))
765 		goto out;
766 	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
767 		  "security_validate_transition:  denied for"
768 		  " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
769 		  o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
770 out:
771 	kfree(o);
772 	kfree(n);
773 	kfree(t);
774 
775 	if (!selinux_enforcing)
776 		return 0;
777 	return -EPERM;
778 }
779 
security_validate_transition(u32 oldsid,u32 newsid,u32 tasksid,u16 orig_tclass)780 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
781 				 u16 orig_tclass)
782 {
783 	struct context *ocontext;
784 	struct context *ncontext;
785 	struct context *tcontext;
786 	struct class_datum *tclass_datum;
787 	struct constraint_node *constraint;
788 	u16 tclass;
789 	int rc = 0;
790 
791 	if (!ss_initialized)
792 		return 0;
793 
794 	read_lock(&policy_rwlock);
795 
796 	tclass = unmap_class(orig_tclass);
797 
798 	if (!tclass || tclass > policydb.p_classes.nprim) {
799 		printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
800 			__func__, tclass);
801 		rc = -EINVAL;
802 		goto out;
803 	}
804 	tclass_datum = policydb.class_val_to_struct[tclass - 1];
805 
806 	ocontext = sidtab_search(&sidtab, oldsid);
807 	if (!ocontext) {
808 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
809 			__func__, oldsid);
810 		rc = -EINVAL;
811 		goto out;
812 	}
813 
814 	ncontext = sidtab_search(&sidtab, newsid);
815 	if (!ncontext) {
816 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
817 			__func__, newsid);
818 		rc = -EINVAL;
819 		goto out;
820 	}
821 
822 	tcontext = sidtab_search(&sidtab, tasksid);
823 	if (!tcontext) {
824 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
825 			__func__, tasksid);
826 		rc = -EINVAL;
827 		goto out;
828 	}
829 
830 	constraint = tclass_datum->validatetrans;
831 	while (constraint) {
832 		if (!constraint_expr_eval(ocontext, ncontext, tcontext,
833 					  constraint->expr)) {
834 			rc = security_validtrans_handle_fail(ocontext, ncontext,
835 							     tcontext, tclass);
836 			goto out;
837 		}
838 		constraint = constraint->next;
839 	}
840 
841 out:
842 	read_unlock(&policy_rwlock);
843 	return rc;
844 }
845 
846 /*
847  * security_bounded_transition - check whether the given
848  * transition is directed to bounded, or not.
849  * It returns 0, if @newsid is bounded by @oldsid.
850  * Otherwise, it returns error code.
851  *
852  * @oldsid : current security identifier
853  * @newsid : destinated security identifier
854  */
security_bounded_transition(u32 old_sid,u32 new_sid)855 int security_bounded_transition(u32 old_sid, u32 new_sid)
856 {
857 	struct context *old_context, *new_context;
858 	struct type_datum *type;
859 	int index;
860 	int rc;
861 
862 	read_lock(&policy_rwlock);
863 
864 	rc = -EINVAL;
865 	old_context = sidtab_search(&sidtab, old_sid);
866 	if (!old_context) {
867 		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
868 		       __func__, old_sid);
869 		goto out;
870 	}
871 
872 	rc = -EINVAL;
873 	new_context = sidtab_search(&sidtab, new_sid);
874 	if (!new_context) {
875 		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
876 		       __func__, new_sid);
877 		goto out;
878 	}
879 
880 	rc = 0;
881 	/* type/domain unchanged */
882 	if (old_context->type == new_context->type)
883 		goto out;
884 
885 	index = new_context->type;
886 	while (true) {
887 		type = flex_array_get_ptr(policydb.type_val_to_struct_array,
888 					  index - 1);
889 		BUG_ON(!type);
890 
891 		/* not bounded anymore */
892 		rc = -EPERM;
893 		if (!type->bounds)
894 			break;
895 
896 		/* @newsid is bounded by @oldsid */
897 		rc = 0;
898 		if (type->bounds == old_context->type)
899 			break;
900 
901 		index = type->bounds;
902 	}
903 
904 	if (rc) {
905 		char *old_name = NULL;
906 		char *new_name = NULL;
907 		u32 length;
908 
909 		if (!context_struct_to_string(old_context,
910 					      &old_name, &length) &&
911 		    !context_struct_to_string(new_context,
912 					      &new_name, &length)) {
913 			audit_log(current->audit_context,
914 				  GFP_ATOMIC, AUDIT_SELINUX_ERR,
915 				  "op=security_bounded_transition "
916 				  "result=denied "
917 				  "oldcontext=%s newcontext=%s",
918 				  old_name, new_name);
919 		}
920 		kfree(new_name);
921 		kfree(old_name);
922 	}
923 out:
924 	read_unlock(&policy_rwlock);
925 
926 	return rc;
927 }
928 
avd_init(struct av_decision * avd)929 static void avd_init(struct av_decision *avd)
930 {
931 	avd->allowed = 0;
932 	avd->auditallow = 0;
933 	avd->auditdeny = 0xffffffff;
934 	avd->seqno = latest_granting;
935 	avd->flags = 0;
936 }
937 
services_compute_xperms_decision(struct extended_perms_decision * xpermd,struct avtab_node * node)938 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
939 					struct avtab_node *node)
940 {
941 	unsigned int i;
942 
943 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
944 		if (xpermd->driver != node->datum.u.xperms->driver)
945 			return;
946 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
947 		if (!security_xperm_test(node->datum.u.xperms->perms.p,
948 					xpermd->driver))
949 			return;
950 	} else {
951 		BUG();
952 	}
953 
954 	if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
955 		xpermd->used |= XPERMS_ALLOWED;
956 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
957 			memset(xpermd->allowed->p, 0xff,
958 					sizeof(xpermd->allowed->p));
959 		}
960 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
961 			for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
962 				xpermd->allowed->p[i] |=
963 					node->datum.u.xperms->perms.p[i];
964 		}
965 	} else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
966 		xpermd->used |= XPERMS_AUDITALLOW;
967 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
968 			memset(xpermd->auditallow->p, 0xff,
969 					sizeof(xpermd->auditallow->p));
970 		}
971 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
972 			for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
973 				xpermd->auditallow->p[i] |=
974 					node->datum.u.xperms->perms.p[i];
975 		}
976 	} else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
977 		xpermd->used |= XPERMS_DONTAUDIT;
978 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
979 			memset(xpermd->dontaudit->p, 0xff,
980 					sizeof(xpermd->dontaudit->p));
981 		}
982 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
983 			for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
984 				xpermd->dontaudit->p[i] |=
985 					node->datum.u.xperms->perms.p[i];
986 		}
987 	} else {
988 		BUG();
989 	}
990 }
991 
security_compute_xperms_decision(u32 ssid,u32 tsid,u16 orig_tclass,u8 driver,struct extended_perms_decision * xpermd)992 void security_compute_xperms_decision(u32 ssid,
993 				u32 tsid,
994 				u16 orig_tclass,
995 				u8 driver,
996 				struct extended_perms_decision *xpermd)
997 {
998 	u16 tclass;
999 	struct context *scontext, *tcontext;
1000 	struct avtab_key avkey;
1001 	struct avtab_node *node;
1002 	struct ebitmap *sattr, *tattr;
1003 	struct ebitmap_node *snode, *tnode;
1004 	unsigned int i, j;
1005 
1006 	xpermd->driver = driver;
1007 	xpermd->used = 0;
1008 	memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1009 	memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1010 	memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1011 
1012 	read_lock(&policy_rwlock);
1013 	if (!ss_initialized)
1014 		goto allow;
1015 
1016 	scontext = sidtab_search(&sidtab, ssid);
1017 	if (!scontext) {
1018 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1019 		       __func__, ssid);
1020 		goto out;
1021 	}
1022 
1023 	tcontext = sidtab_search(&sidtab, tsid);
1024 	if (!tcontext) {
1025 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1026 		       __func__, tsid);
1027 		goto out;
1028 	}
1029 
1030 	tclass = unmap_class(orig_tclass);
1031 	if (unlikely(orig_tclass && !tclass)) {
1032 		if (policydb.allow_unknown)
1033 			goto allow;
1034 		goto out;
1035 	}
1036 
1037 
1038 	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1039 		if (printk_ratelimit())
1040                 	printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
1041 		goto out;
1042 	}
1043 
1044 	avkey.target_class = tclass;
1045 	avkey.specified = AVTAB_XPERMS;
1046 	sattr = flex_array_get(policydb.type_attr_map_array,
1047 				scontext->type - 1);
1048 	BUG_ON(!sattr);
1049 	tattr = flex_array_get(policydb.type_attr_map_array,
1050 				tcontext->type - 1);
1051 	BUG_ON(!tattr);
1052 	ebitmap_for_each_positive_bit(sattr, snode, i) {
1053 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
1054 			avkey.source_type = i + 1;
1055 			avkey.target_type = j + 1;
1056 			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1057 			     node;
1058 			     node = avtab_search_node_next(node, avkey.specified))
1059 				services_compute_xperms_decision(xpermd, node);
1060 
1061 			cond_compute_xperms(&policydb.te_cond_avtab,
1062 						&avkey, xpermd);
1063 		}
1064 	}
1065 out:
1066 	read_unlock(&policy_rwlock);
1067 	return;
1068 allow:
1069 	memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1070 	goto out;
1071 }
1072 
1073 /**
1074  * security_compute_av - Compute access vector decisions.
1075  * @ssid: source security identifier
1076  * @tsid: target security identifier
1077  * @tclass: target security class
1078  * @avd: access vector decisions
1079  * @xperms: extended permissions
1080  *
1081  * Compute a set of access vector decisions based on the
1082  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1083  */
security_compute_av(u32 ssid,u32 tsid,u16 orig_tclass,struct av_decision * avd,struct extended_perms * xperms)1084 void security_compute_av(u32 ssid,
1085 			 u32 tsid,
1086 			 u16 orig_tclass,
1087 			 struct av_decision *avd,
1088 			 struct extended_perms *xperms)
1089 {
1090 	u16 tclass;
1091 	struct context *scontext = NULL, *tcontext = NULL;
1092 
1093 	read_lock(&policy_rwlock);
1094 	avd_init(avd);
1095 	xperms->len = 0;
1096 	if (!ss_initialized)
1097 		goto allow;
1098 
1099 	scontext = sidtab_search(&sidtab, ssid);
1100 	if (!scontext) {
1101 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1102 		       __func__, ssid);
1103 		goto out;
1104 	}
1105 
1106 	/* permissive domain? */
1107 	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1108 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1109 
1110 	tcontext = sidtab_search(&sidtab, tsid);
1111 	if (!tcontext) {
1112 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1113 		       __func__, tsid);
1114 		goto out;
1115 	}
1116 
1117 	tclass = unmap_class(orig_tclass);
1118 	if (unlikely(orig_tclass && !tclass)) {
1119 		if (policydb.allow_unknown)
1120 			goto allow;
1121 		goto out;
1122 	}
1123 	context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1124 	map_decision(orig_tclass, avd, policydb.allow_unknown);
1125 out:
1126 	read_unlock(&policy_rwlock);
1127 	return;
1128 allow:
1129 	avd->allowed = 0xffffffff;
1130 	goto out;
1131 }
1132 
security_compute_av_user(u32 ssid,u32 tsid,u16 tclass,struct av_decision * avd)1133 void security_compute_av_user(u32 ssid,
1134 			      u32 tsid,
1135 			      u16 tclass,
1136 			      struct av_decision *avd)
1137 {
1138 	struct context *scontext = NULL, *tcontext = NULL;
1139 
1140 	read_lock(&policy_rwlock);
1141 	avd_init(avd);
1142 	if (!ss_initialized)
1143 		goto allow;
1144 
1145 	scontext = sidtab_search(&sidtab, ssid);
1146 	if (!scontext) {
1147 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1148 		       __func__, ssid);
1149 		goto out;
1150 	}
1151 
1152 	/* permissive domain? */
1153 	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1154 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1155 
1156 	tcontext = sidtab_search(&sidtab, tsid);
1157 	if (!tcontext) {
1158 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1159 		       __func__, tsid);
1160 		goto out;
1161 	}
1162 
1163 	if (unlikely(!tclass)) {
1164 		if (policydb.allow_unknown)
1165 			goto allow;
1166 		goto out;
1167 	}
1168 
1169 	context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1170  out:
1171 	read_unlock(&policy_rwlock);
1172 	return;
1173 allow:
1174 	avd->allowed = 0xffffffff;
1175 	goto out;
1176 }
1177 
1178 /*
1179  * Write the security context string representation of
1180  * the context structure `context' into a dynamically
1181  * allocated string of the correct size.  Set `*scontext'
1182  * to point to this string and set `*scontext_len' to
1183  * the length of the string.
1184  */
context_struct_to_string(struct context * context,char ** scontext,u32 * scontext_len)1185 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1186 {
1187 	char *scontextp;
1188 
1189 	if (scontext)
1190 		*scontext = NULL;
1191 	*scontext_len = 0;
1192 
1193 	if (context->len) {
1194 		*scontext_len = context->len;
1195 		*scontext = kstrdup(context->str, GFP_ATOMIC);
1196 		if (!(*scontext))
1197 			return -ENOMEM;
1198 		return 0;
1199 	}
1200 
1201 	/* Compute the size of the context. */
1202 	*scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1203 	*scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1204 	*scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1205 	*scontext_len += mls_compute_context_len(context);
1206 
1207 	if (!scontext)
1208 		return 0;
1209 
1210 	/* Allocate space for the context; caller must free this space. */
1211 	scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1212 	if (!scontextp)
1213 		return -ENOMEM;
1214 	*scontext = scontextp;
1215 
1216 	/*
1217 	 * Copy the user name, role name and type name into the context.
1218 	 */
1219 	sprintf(scontextp, "%s:%s:%s",
1220 		sym_name(&policydb, SYM_USERS, context->user - 1),
1221 		sym_name(&policydb, SYM_ROLES, context->role - 1),
1222 		sym_name(&policydb, SYM_TYPES, context->type - 1));
1223 	scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1224 		     1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1225 		     1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1226 
1227 	mls_sid_to_context(context, &scontextp);
1228 
1229 	*scontextp = 0;
1230 
1231 	return 0;
1232 }
1233 
1234 #include "initial_sid_to_string.h"
1235 
security_get_initial_sid_context(u32 sid)1236 const char *security_get_initial_sid_context(u32 sid)
1237 {
1238 	if (unlikely(sid > SECINITSID_NUM))
1239 		return NULL;
1240 	return initial_sid_to_string[sid];
1241 }
1242 
security_sid_to_context_core(u32 sid,char ** scontext,u32 * scontext_len,int force)1243 static int security_sid_to_context_core(u32 sid, char **scontext,
1244 					u32 *scontext_len, int force)
1245 {
1246 	struct context *context;
1247 	int rc = 0;
1248 
1249 	if (scontext)
1250 		*scontext = NULL;
1251 	*scontext_len  = 0;
1252 
1253 	if (!ss_initialized) {
1254 		if (sid <= SECINITSID_NUM) {
1255 			char *scontextp;
1256 
1257 			*scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1258 			if (!scontext)
1259 				goto out;
1260 			scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1261 			if (!scontextp) {
1262 				rc = -ENOMEM;
1263 				goto out;
1264 			}
1265 			strcpy(scontextp, initial_sid_to_string[sid]);
1266 			*scontext = scontextp;
1267 			goto out;
1268 		}
1269 		printk(KERN_ERR "SELinux: %s:  called before initial "
1270 		       "load_policy on unknown SID %d\n", __func__, sid);
1271 		rc = -EINVAL;
1272 		goto out;
1273 	}
1274 	read_lock(&policy_rwlock);
1275 	if (force)
1276 		context = sidtab_search_force(&sidtab, sid);
1277 	else
1278 		context = sidtab_search(&sidtab, sid);
1279 	if (!context) {
1280 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1281 			__func__, sid);
1282 		rc = -EINVAL;
1283 		goto out_unlock;
1284 	}
1285 	rc = context_struct_to_string(context, scontext, scontext_len);
1286 out_unlock:
1287 	read_unlock(&policy_rwlock);
1288 out:
1289 	return rc;
1290 
1291 }
1292 
1293 /**
1294  * security_sid_to_context - Obtain a context for a given SID.
1295  * @sid: security identifier, SID
1296  * @scontext: security context
1297  * @scontext_len: length in bytes
1298  *
1299  * Write the string representation of the context associated with @sid
1300  * into a dynamically allocated string of the correct size.  Set @scontext
1301  * to point to this string and set @scontext_len to the length of the string.
1302  */
security_sid_to_context(u32 sid,char ** scontext,u32 * scontext_len)1303 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1304 {
1305 	return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1306 }
1307 
security_sid_to_context_force(u32 sid,char ** scontext,u32 * scontext_len)1308 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1309 {
1310 	return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1311 }
1312 
1313 /*
1314  * Caveat:  Mutates scontext.
1315  */
string_to_context_struct(struct policydb * pol,struct sidtab * sidtabp,char * scontext,u32 scontext_len,struct context * ctx,u32 def_sid)1316 static int string_to_context_struct(struct policydb *pol,
1317 				    struct sidtab *sidtabp,
1318 				    char *scontext,
1319 				    u32 scontext_len,
1320 				    struct context *ctx,
1321 				    u32 def_sid)
1322 {
1323 	struct role_datum *role;
1324 	struct type_datum *typdatum;
1325 	struct user_datum *usrdatum;
1326 	char *scontextp, *p, oldc;
1327 	int rc = 0;
1328 
1329 	context_init(ctx);
1330 
1331 	/* Parse the security context. */
1332 
1333 	rc = -EINVAL;
1334 	scontextp = (char *) scontext;
1335 
1336 	/* Extract the user. */
1337 	p = scontextp;
1338 	while (*p && *p != ':')
1339 		p++;
1340 
1341 	if (*p == 0)
1342 		goto out;
1343 
1344 	*p++ = 0;
1345 
1346 	usrdatum = hashtab_search(pol->p_users.table, scontextp);
1347 	if (!usrdatum)
1348 		goto out;
1349 
1350 	ctx->user = usrdatum->value;
1351 
1352 	/* Extract role. */
1353 	scontextp = p;
1354 	while (*p && *p != ':')
1355 		p++;
1356 
1357 	if (*p == 0)
1358 		goto out;
1359 
1360 	*p++ = 0;
1361 
1362 	role = hashtab_search(pol->p_roles.table, scontextp);
1363 	if (!role)
1364 		goto out;
1365 	ctx->role = role->value;
1366 
1367 	/* Extract type. */
1368 	scontextp = p;
1369 	while (*p && *p != ':')
1370 		p++;
1371 	oldc = *p;
1372 	*p++ = 0;
1373 
1374 	typdatum = hashtab_search(pol->p_types.table, scontextp);
1375 	if (!typdatum || typdatum->attribute)
1376 		goto out;
1377 
1378 	ctx->type = typdatum->value;
1379 
1380 	rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1381 	if (rc)
1382 		goto out;
1383 
1384 	rc = -EINVAL;
1385 	if ((p - scontext) < scontext_len)
1386 		goto out;
1387 
1388 	/* Check the validity of the new context. */
1389 	if (!policydb_context_isvalid(pol, ctx))
1390 		goto out;
1391 	rc = 0;
1392 out:
1393 	if (rc)
1394 		context_destroy(ctx);
1395 	return rc;
1396 }
1397 
security_context_to_sid_core(const char * scontext,u32 scontext_len,u32 * sid,u32 def_sid,gfp_t gfp_flags,int force)1398 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1399 					u32 *sid, u32 def_sid, gfp_t gfp_flags,
1400 					int force)
1401 {
1402 	char *scontext2, *str = NULL;
1403 	struct context context;
1404 	int rc = 0;
1405 
1406 	/* An empty security context is never valid. */
1407 	if (!scontext_len)
1408 		return -EINVAL;
1409 
1410 	if (!ss_initialized) {
1411 		int i;
1412 
1413 		for (i = 1; i < SECINITSID_NUM; i++) {
1414 			if (!strcmp(initial_sid_to_string[i], scontext)) {
1415 				*sid = i;
1416 				return 0;
1417 			}
1418 		}
1419 		*sid = SECINITSID_KERNEL;
1420 		return 0;
1421 	}
1422 	*sid = SECSID_NULL;
1423 
1424 	/* Copy the string so that we can modify the copy as we parse it. */
1425 	scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1426 	if (!scontext2)
1427 		return -ENOMEM;
1428 	memcpy(scontext2, scontext, scontext_len);
1429 	scontext2[scontext_len] = 0;
1430 
1431 	if (force) {
1432 		/* Save another copy for storing in uninterpreted form */
1433 		rc = -ENOMEM;
1434 		str = kstrdup(scontext2, gfp_flags);
1435 		if (!str)
1436 			goto out;
1437 	}
1438 
1439 	read_lock(&policy_rwlock);
1440 	rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1441 				      scontext_len, &context, def_sid);
1442 	if (rc == -EINVAL && force) {
1443 		context.str = str;
1444 		context.len = scontext_len;
1445 		str = NULL;
1446 	} else if (rc)
1447 		goto out_unlock;
1448 	rc = sidtab_context_to_sid(&sidtab, &context, sid);
1449 	context_destroy(&context);
1450 out_unlock:
1451 	read_unlock(&policy_rwlock);
1452 out:
1453 	kfree(scontext2);
1454 	kfree(str);
1455 	return rc;
1456 }
1457 
1458 /**
1459  * security_context_to_sid - Obtain a SID for a given security context.
1460  * @scontext: security context
1461  * @scontext_len: length in bytes
1462  * @sid: security identifier, SID
1463  *
1464  * Obtains a SID associated with the security context that
1465  * has the string representation specified by @scontext.
1466  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1467  * memory is available, or 0 on success.
1468  */
security_context_to_sid(const char * scontext,u32 scontext_len,u32 * sid)1469 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1470 {
1471 	return security_context_to_sid_core(scontext, scontext_len,
1472 					    sid, SECSID_NULL, GFP_KERNEL, 0);
1473 }
1474 
1475 /**
1476  * security_context_to_sid_default - Obtain a SID for a given security context,
1477  * falling back to specified default if needed.
1478  *
1479  * @scontext: security context
1480  * @scontext_len: length in bytes
1481  * @sid: security identifier, SID
1482  * @def_sid: default SID to assign on error
1483  *
1484  * Obtains a SID associated with the security context that
1485  * has the string representation specified by @scontext.
1486  * The default SID is passed to the MLS layer to be used to allow
1487  * kernel labeling of the MLS field if the MLS field is not present
1488  * (for upgrading to MLS without full relabel).
1489  * Implicitly forces adding of the context even if it cannot be mapped yet.
1490  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1491  * memory is available, or 0 on success.
1492  */
security_context_to_sid_default(const char * scontext,u32 scontext_len,u32 * sid,u32 def_sid,gfp_t gfp_flags)1493 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1494 				    u32 *sid, u32 def_sid, gfp_t gfp_flags)
1495 {
1496 	return security_context_to_sid_core(scontext, scontext_len,
1497 					    sid, def_sid, gfp_flags, 1);
1498 }
1499 
security_context_to_sid_force(const char * scontext,u32 scontext_len,u32 * sid)1500 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1501 				  u32 *sid)
1502 {
1503 	return security_context_to_sid_core(scontext, scontext_len,
1504 					    sid, SECSID_NULL, GFP_KERNEL, 1);
1505 }
1506 
compute_sid_handle_invalid_context(struct context * scontext,struct context * tcontext,u16 tclass,struct context * newcontext)1507 static int compute_sid_handle_invalid_context(
1508 	struct context *scontext,
1509 	struct context *tcontext,
1510 	u16 tclass,
1511 	struct context *newcontext)
1512 {
1513 	char *s = NULL, *t = NULL, *n = NULL;
1514 	u32 slen, tlen, nlen;
1515 
1516 	if (context_struct_to_string(scontext, &s, &slen))
1517 		goto out;
1518 	if (context_struct_to_string(tcontext, &t, &tlen))
1519 		goto out;
1520 	if (context_struct_to_string(newcontext, &n, &nlen))
1521 		goto out;
1522 	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1523 		  "security_compute_sid:  invalid context %s"
1524 		  " for scontext=%s"
1525 		  " tcontext=%s"
1526 		  " tclass=%s",
1527 		  n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1528 out:
1529 	kfree(s);
1530 	kfree(t);
1531 	kfree(n);
1532 	if (!selinux_enforcing)
1533 		return 0;
1534 	return -EACCES;
1535 }
1536 
filename_compute_type(struct policydb * p,struct context * newcontext,u32 stype,u32 ttype,u16 tclass,const char * objname)1537 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1538 				  u32 stype, u32 ttype, u16 tclass,
1539 				  const char *objname)
1540 {
1541 	struct filename_trans ft;
1542 	struct filename_trans_datum *otype;
1543 
1544 	/*
1545 	 * Most filename trans rules are going to live in specific directories
1546 	 * like /dev or /var/run.  This bitmap will quickly skip rule searches
1547 	 * if the ttype does not contain any rules.
1548 	 */
1549 	if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1550 		return;
1551 
1552 	ft.stype = stype;
1553 	ft.ttype = ttype;
1554 	ft.tclass = tclass;
1555 	ft.name = objname;
1556 
1557 	otype = hashtab_search(p->filename_trans, &ft);
1558 	if (otype)
1559 		newcontext->type = otype->otype;
1560 }
1561 
security_compute_sid(u32 ssid,u32 tsid,u16 orig_tclass,u32 specified,const char * objname,u32 * out_sid,bool kern)1562 static int security_compute_sid(u32 ssid,
1563 				u32 tsid,
1564 				u16 orig_tclass,
1565 				u32 specified,
1566 				const char *objname,
1567 				u32 *out_sid,
1568 				bool kern)
1569 {
1570 	struct class_datum *cladatum = NULL;
1571 	struct context *scontext = NULL, *tcontext = NULL, newcontext;
1572 	struct role_trans *roletr = NULL;
1573 	struct avtab_key avkey;
1574 	struct avtab_datum *avdatum;
1575 	struct avtab_node *node;
1576 	u16 tclass;
1577 	int rc = 0;
1578 	bool sock;
1579 
1580 	if (!ss_initialized) {
1581 		switch (orig_tclass) {
1582 		case SECCLASS_PROCESS: /* kernel value */
1583 			*out_sid = ssid;
1584 			break;
1585 		default:
1586 			*out_sid = tsid;
1587 			break;
1588 		}
1589 		goto out;
1590 	}
1591 
1592 	context_init(&newcontext);
1593 
1594 	read_lock(&policy_rwlock);
1595 
1596 	if (kern) {
1597 		tclass = unmap_class(orig_tclass);
1598 		sock = security_is_socket_class(orig_tclass);
1599 	} else {
1600 		tclass = orig_tclass;
1601 		sock = security_is_socket_class(map_class(tclass));
1602 	}
1603 
1604 	scontext = sidtab_search(&sidtab, ssid);
1605 	if (!scontext) {
1606 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1607 		       __func__, ssid);
1608 		rc = -EINVAL;
1609 		goto out_unlock;
1610 	}
1611 	tcontext = sidtab_search(&sidtab, tsid);
1612 	if (!tcontext) {
1613 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1614 		       __func__, tsid);
1615 		rc = -EINVAL;
1616 		goto out_unlock;
1617 	}
1618 
1619 	if (tclass && tclass <= policydb.p_classes.nprim)
1620 		cladatum = policydb.class_val_to_struct[tclass - 1];
1621 
1622 	/* Set the user identity. */
1623 	switch (specified) {
1624 	case AVTAB_TRANSITION:
1625 	case AVTAB_CHANGE:
1626 		if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1627 			newcontext.user = tcontext->user;
1628 		} else {
1629 			/* notice this gets both DEFAULT_SOURCE and unset */
1630 			/* Use the process user identity. */
1631 			newcontext.user = scontext->user;
1632 		}
1633 		break;
1634 	case AVTAB_MEMBER:
1635 		/* Use the related object owner. */
1636 		newcontext.user = tcontext->user;
1637 		break;
1638 	}
1639 
1640 	/* Set the role to default values. */
1641 	if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1642 		newcontext.role = scontext->role;
1643 	} else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1644 		newcontext.role = tcontext->role;
1645 	} else {
1646 		if ((tclass == policydb.process_class) || (sock == true))
1647 			newcontext.role = scontext->role;
1648 		else
1649 			newcontext.role = OBJECT_R_VAL;
1650 	}
1651 
1652 	/* Set the type to default values. */
1653 	if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1654 		newcontext.type = scontext->type;
1655 	} else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1656 		newcontext.type = tcontext->type;
1657 	} else {
1658 		if ((tclass == policydb.process_class) || (sock == true)) {
1659 			/* Use the type of process. */
1660 			newcontext.type = scontext->type;
1661 		} else {
1662 			/* Use the type of the related object. */
1663 			newcontext.type = tcontext->type;
1664 		}
1665 	}
1666 
1667 	/* Look for a type transition/member/change rule. */
1668 	avkey.source_type = scontext->type;
1669 	avkey.target_type = tcontext->type;
1670 	avkey.target_class = tclass;
1671 	avkey.specified = specified;
1672 	avdatum = avtab_search(&policydb.te_avtab, &avkey);
1673 
1674 	/* If no permanent rule, also check for enabled conditional rules */
1675 	if (!avdatum) {
1676 		node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1677 		for (; node; node = avtab_search_node_next(node, specified)) {
1678 			if (node->key.specified & AVTAB_ENABLED) {
1679 				avdatum = &node->datum;
1680 				break;
1681 			}
1682 		}
1683 	}
1684 
1685 	if (avdatum) {
1686 		/* Use the type from the type transition/member/change rule. */
1687 		newcontext.type = avdatum->u.data;
1688 	}
1689 
1690 	/* if we have a objname this is a file trans check so check those rules */
1691 	if (objname)
1692 		filename_compute_type(&policydb, &newcontext, scontext->type,
1693 				      tcontext->type, tclass, objname);
1694 
1695 	/* Check for class-specific changes. */
1696 	if (specified & AVTAB_TRANSITION) {
1697 		/* Look for a role transition rule. */
1698 		for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1699 			if ((roletr->role == scontext->role) &&
1700 			    (roletr->type == tcontext->type) &&
1701 			    (roletr->tclass == tclass)) {
1702 				/* Use the role transition rule. */
1703 				newcontext.role = roletr->new_role;
1704 				break;
1705 			}
1706 		}
1707 	}
1708 
1709 	/* Set the MLS attributes.
1710 	   This is done last because it may allocate memory. */
1711 	rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1712 			     &newcontext, sock);
1713 	if (rc)
1714 		goto out_unlock;
1715 
1716 	/* Check the validity of the context. */
1717 	if (!policydb_context_isvalid(&policydb, &newcontext)) {
1718 		rc = compute_sid_handle_invalid_context(scontext,
1719 							tcontext,
1720 							tclass,
1721 							&newcontext);
1722 		if (rc)
1723 			goto out_unlock;
1724 	}
1725 	/* Obtain the sid for the context. */
1726 	rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1727 out_unlock:
1728 	read_unlock(&policy_rwlock);
1729 	context_destroy(&newcontext);
1730 out:
1731 	return rc;
1732 }
1733 
1734 /**
1735  * security_transition_sid - Compute the SID for a new subject/object.
1736  * @ssid: source security identifier
1737  * @tsid: target security identifier
1738  * @tclass: target security class
1739  * @out_sid: security identifier for new subject/object
1740  *
1741  * Compute a SID to use for labeling a new subject or object in the
1742  * class @tclass based on a SID pair (@ssid, @tsid).
1743  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1744  * if insufficient memory is available, or %0 if the new SID was
1745  * computed successfully.
1746  */
security_transition_sid(u32 ssid,u32 tsid,u16 tclass,const struct qstr * qstr,u32 * out_sid)1747 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1748 			    const struct qstr *qstr, u32 *out_sid)
1749 {
1750 	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1751 				    qstr ? qstr->name : NULL, out_sid, true);
1752 }
1753 
security_transition_sid_user(u32 ssid,u32 tsid,u16 tclass,const char * objname,u32 * out_sid)1754 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1755 				 const char *objname, u32 *out_sid)
1756 {
1757 	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1758 				    objname, out_sid, false);
1759 }
1760 
1761 /**
1762  * security_member_sid - Compute the SID for member selection.
1763  * @ssid: source security identifier
1764  * @tsid: target security identifier
1765  * @tclass: target security class
1766  * @out_sid: security identifier for selected member
1767  *
1768  * Compute a SID to use when selecting a member of a polyinstantiated
1769  * object of class @tclass based on a SID pair (@ssid, @tsid).
1770  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1771  * if insufficient memory is available, or %0 if the SID was
1772  * computed successfully.
1773  */
security_member_sid(u32 ssid,u32 tsid,u16 tclass,u32 * out_sid)1774 int security_member_sid(u32 ssid,
1775 			u32 tsid,
1776 			u16 tclass,
1777 			u32 *out_sid)
1778 {
1779 	return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1780 				    out_sid, false);
1781 }
1782 
1783 /**
1784  * security_change_sid - Compute the SID for object relabeling.
1785  * @ssid: source security identifier
1786  * @tsid: target security identifier
1787  * @tclass: target security class
1788  * @out_sid: security identifier for selected member
1789  *
1790  * Compute a SID to use for relabeling an object of class @tclass
1791  * based on a SID pair (@ssid, @tsid).
1792  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1793  * if insufficient memory is available, or %0 if the SID was
1794  * computed successfully.
1795  */
security_change_sid(u32 ssid,u32 tsid,u16 tclass,u32 * out_sid)1796 int security_change_sid(u32 ssid,
1797 			u32 tsid,
1798 			u16 tclass,
1799 			u32 *out_sid)
1800 {
1801 	return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1802 				    out_sid, false);
1803 }
1804 
1805 /* Clone the SID into the new SID table. */
clone_sid(u32 sid,struct context * context,void * arg)1806 static int clone_sid(u32 sid,
1807 		     struct context *context,
1808 		     void *arg)
1809 {
1810 	struct sidtab *s = arg;
1811 
1812 	if (sid > SECINITSID_NUM)
1813 		return sidtab_insert(s, sid, context);
1814 	else
1815 		return 0;
1816 }
1817 
convert_context_handle_invalid_context(struct context * context)1818 static inline int convert_context_handle_invalid_context(struct context *context)
1819 {
1820 	char *s;
1821 	u32 len;
1822 
1823 	if (selinux_enforcing)
1824 		return -EINVAL;
1825 
1826 	if (!context_struct_to_string(context, &s, &len)) {
1827 		printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1828 		kfree(s);
1829 	}
1830 	return 0;
1831 }
1832 
1833 struct convert_context_args {
1834 	struct policydb *oldp;
1835 	struct policydb *newp;
1836 };
1837 
1838 /*
1839  * Convert the values in the security context
1840  * structure `c' from the values specified
1841  * in the policy `p->oldp' to the values specified
1842  * in the policy `p->newp'.  Verify that the
1843  * context is valid under the new policy.
1844  */
convert_context(u32 key,struct context * c,void * p)1845 static int convert_context(u32 key,
1846 			   struct context *c,
1847 			   void *p)
1848 {
1849 	struct convert_context_args *args;
1850 	struct context oldc;
1851 	struct ocontext *oc;
1852 	struct mls_range *range;
1853 	struct role_datum *role;
1854 	struct type_datum *typdatum;
1855 	struct user_datum *usrdatum;
1856 	char *s;
1857 	u32 len;
1858 	int rc = 0;
1859 
1860 	if (key <= SECINITSID_NUM)
1861 		goto out;
1862 
1863 	args = p;
1864 
1865 	if (c->str) {
1866 		struct context ctx;
1867 
1868 		rc = -ENOMEM;
1869 		s = kstrdup(c->str, GFP_KERNEL);
1870 		if (!s)
1871 			goto out;
1872 
1873 		rc = string_to_context_struct(args->newp, NULL, s,
1874 					      c->len, &ctx, SECSID_NULL);
1875 		kfree(s);
1876 		if (!rc) {
1877 			printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1878 			       c->str);
1879 			/* Replace string with mapped representation. */
1880 			kfree(c->str);
1881 			memcpy(c, &ctx, sizeof(*c));
1882 			goto out;
1883 		} else if (rc == -EINVAL) {
1884 			/* Retain string representation for later mapping. */
1885 			rc = 0;
1886 			goto out;
1887 		} else {
1888 			/* Other error condition, e.g. ENOMEM. */
1889 			printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1890 			       c->str, -rc);
1891 			goto out;
1892 		}
1893 	}
1894 
1895 	rc = context_cpy(&oldc, c);
1896 	if (rc)
1897 		goto out;
1898 
1899 	/* Convert the user. */
1900 	rc = -EINVAL;
1901 	usrdatum = hashtab_search(args->newp->p_users.table,
1902 				  sym_name(args->oldp, SYM_USERS, c->user - 1));
1903 	if (!usrdatum)
1904 		goto bad;
1905 	c->user = usrdatum->value;
1906 
1907 	/* Convert the role. */
1908 	rc = -EINVAL;
1909 	role = hashtab_search(args->newp->p_roles.table,
1910 			      sym_name(args->oldp, SYM_ROLES, c->role - 1));
1911 	if (!role)
1912 		goto bad;
1913 	c->role = role->value;
1914 
1915 	/* Convert the type. */
1916 	rc = -EINVAL;
1917 	typdatum = hashtab_search(args->newp->p_types.table,
1918 				  sym_name(args->oldp, SYM_TYPES, c->type - 1));
1919 	if (!typdatum)
1920 		goto bad;
1921 	c->type = typdatum->value;
1922 
1923 	/* Convert the MLS fields if dealing with MLS policies */
1924 	if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1925 		rc = mls_convert_context(args->oldp, args->newp, c);
1926 		if (rc)
1927 			goto bad;
1928 	} else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1929 		/*
1930 		 * Switching between MLS and non-MLS policy:
1931 		 * free any storage used by the MLS fields in the
1932 		 * context for all existing entries in the sidtab.
1933 		 */
1934 		mls_context_destroy(c);
1935 	} else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1936 		/*
1937 		 * Switching between non-MLS and MLS policy:
1938 		 * ensure that the MLS fields of the context for all
1939 		 * existing entries in the sidtab are filled in with a
1940 		 * suitable default value, likely taken from one of the
1941 		 * initial SIDs.
1942 		 */
1943 		oc = args->newp->ocontexts[OCON_ISID];
1944 		while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1945 			oc = oc->next;
1946 		rc = -EINVAL;
1947 		if (!oc) {
1948 			printk(KERN_ERR "SELinux:  unable to look up"
1949 				" the initial SIDs list\n");
1950 			goto bad;
1951 		}
1952 		range = &oc->context[0].range;
1953 		rc = mls_range_set(c, range);
1954 		if (rc)
1955 			goto bad;
1956 	}
1957 
1958 	/* Check the validity of the new context. */
1959 	if (!policydb_context_isvalid(args->newp, c)) {
1960 		rc = convert_context_handle_invalid_context(&oldc);
1961 		if (rc)
1962 			goto bad;
1963 	}
1964 
1965 	context_destroy(&oldc);
1966 
1967 	rc = 0;
1968 out:
1969 	return rc;
1970 bad:
1971 	/* Map old representation to string and save it. */
1972 	rc = context_struct_to_string(&oldc, &s, &len);
1973 	if (rc)
1974 		return rc;
1975 	context_destroy(&oldc);
1976 	context_destroy(c);
1977 	c->str = s;
1978 	c->len = len;
1979 	printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1980 	       c->str);
1981 	rc = 0;
1982 	goto out;
1983 }
1984 
security_load_policycaps(void)1985 static void security_load_policycaps(void)
1986 {
1987 	selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1988 						  POLICYDB_CAPABILITY_NETPEER);
1989 	selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1990 						  POLICYDB_CAPABILITY_OPENPERM);
1991 }
1992 
1993 static int security_preserve_bools(struct policydb *p);
1994 
1995 /**
1996  * security_load_policy - Load a security policy configuration.
1997  * @data: binary policy data
1998  * @len: length of data in bytes
1999  *
2000  * Load a new set of security policy configuration data,
2001  * validate it and convert the SID table as necessary.
2002  * This function will flush the access vector cache after
2003  * loading the new policy.
2004  */
security_load_policy(void * data,size_t len)2005 int security_load_policy(void *data, size_t len)
2006 {
2007 	struct policydb oldpolicydb, newpolicydb;
2008 	struct sidtab oldsidtab, newsidtab;
2009 	struct selinux_mapping *oldmap, *map = NULL;
2010 	struct convert_context_args args;
2011 	u32 seqno;
2012 	u16 map_size;
2013 	int rc = 0;
2014 	struct policy_file file = { data, len }, *fp = &file;
2015 
2016 	if (!ss_initialized) {
2017 		avtab_cache_init();
2018 		rc = policydb_read(&policydb, fp);
2019 		if (rc) {
2020 			avtab_cache_destroy();
2021 			return rc;
2022 		}
2023 
2024 		policydb.len = len;
2025 		rc = selinux_set_mapping(&policydb, secclass_map,
2026 					 &current_mapping,
2027 					 &current_mapping_size);
2028 		if (rc) {
2029 			policydb_destroy(&policydb);
2030 			avtab_cache_destroy();
2031 			return rc;
2032 		}
2033 
2034 		rc = policydb_load_isids(&policydb, &sidtab);
2035 		if (rc) {
2036 			policydb_destroy(&policydb);
2037 			avtab_cache_destroy();
2038 			return rc;
2039 		}
2040 
2041 		security_load_policycaps();
2042 		ss_initialized = 1;
2043 		seqno = ++latest_granting;
2044 		selinux_complete_init();
2045 		avc_ss_reset(seqno);
2046 		selnl_notify_policyload(seqno);
2047 		selinux_status_update_policyload(seqno);
2048 		selinux_netlbl_cache_invalidate();
2049 		selinux_xfrm_notify_policyload();
2050 		return 0;
2051 	}
2052 
2053 #if 0
2054 	sidtab_hash_eval(&sidtab, "sids");
2055 #endif
2056 
2057 	rc = policydb_read(&newpolicydb, fp);
2058 	if (rc)
2059 		return rc;
2060 
2061 	newpolicydb.len = len;
2062 	/* If switching between different policy types, log MLS status */
2063 	if (policydb.mls_enabled && !newpolicydb.mls_enabled)
2064 		printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2065 	else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
2066 		printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2067 
2068 	rc = policydb_load_isids(&newpolicydb, &newsidtab);
2069 	if (rc) {
2070 		printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2071 		policydb_destroy(&newpolicydb);
2072 		return rc;
2073 	}
2074 
2075 	rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
2076 	if (rc)
2077 		goto err;
2078 
2079 	rc = security_preserve_bools(&newpolicydb);
2080 	if (rc) {
2081 		printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2082 		goto err;
2083 	}
2084 
2085 	/* Clone the SID table. */
2086 	sidtab_shutdown(&sidtab);
2087 
2088 	rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2089 	if (rc)
2090 		goto err;
2091 
2092 	/*
2093 	 * Convert the internal representations of contexts
2094 	 * in the new SID table.
2095 	 */
2096 	args.oldp = &policydb;
2097 	args.newp = &newpolicydb;
2098 	rc = sidtab_map(&newsidtab, convert_context, &args);
2099 	if (rc) {
2100 		printk(KERN_ERR "SELinux:  unable to convert the internal"
2101 			" representation of contexts in the new SID"
2102 			" table\n");
2103 		goto err;
2104 	}
2105 
2106 	/* Save the old policydb and SID table to free later. */
2107 	memcpy(&oldpolicydb, &policydb, sizeof policydb);
2108 	sidtab_set(&oldsidtab, &sidtab);
2109 
2110 	/* Install the new policydb and SID table. */
2111 	write_lock_irq(&policy_rwlock);
2112 	memcpy(&policydb, &newpolicydb, sizeof policydb);
2113 	sidtab_set(&sidtab, &newsidtab);
2114 	security_load_policycaps();
2115 	oldmap = current_mapping;
2116 	current_mapping = map;
2117 	current_mapping_size = map_size;
2118 	seqno = ++latest_granting;
2119 	write_unlock_irq(&policy_rwlock);
2120 
2121 	/* Free the old policydb and SID table. */
2122 	policydb_destroy(&oldpolicydb);
2123 	sidtab_destroy(&oldsidtab);
2124 	kfree(oldmap);
2125 
2126 	avc_ss_reset(seqno);
2127 	selnl_notify_policyload(seqno);
2128 	selinux_status_update_policyload(seqno);
2129 	selinux_netlbl_cache_invalidate();
2130 	selinux_xfrm_notify_policyload();
2131 
2132 	return 0;
2133 
2134 err:
2135 	kfree(map);
2136 	sidtab_destroy(&newsidtab);
2137 	policydb_destroy(&newpolicydb);
2138 	return rc;
2139 
2140 }
2141 
security_policydb_len(void)2142 size_t security_policydb_len(void)
2143 {
2144 	size_t len;
2145 
2146 	read_lock(&policy_rwlock);
2147 	len = policydb.len;
2148 	read_unlock(&policy_rwlock);
2149 
2150 	return len;
2151 }
2152 
2153 /**
2154  * security_port_sid - Obtain the SID for a port.
2155  * @protocol: protocol number
2156  * @port: port number
2157  * @out_sid: security identifier
2158  */
security_port_sid(u8 protocol,u16 port,u32 * out_sid)2159 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2160 {
2161 	struct ocontext *c;
2162 	int rc = 0;
2163 
2164 	read_lock(&policy_rwlock);
2165 
2166 	c = policydb.ocontexts[OCON_PORT];
2167 	while (c) {
2168 		if (c->u.port.protocol == protocol &&
2169 		    c->u.port.low_port <= port &&
2170 		    c->u.port.high_port >= port)
2171 			break;
2172 		c = c->next;
2173 	}
2174 
2175 	if (c) {
2176 		if (!c->sid[0]) {
2177 			rc = sidtab_context_to_sid(&sidtab,
2178 						   &c->context[0],
2179 						   &c->sid[0]);
2180 			if (rc)
2181 				goto out;
2182 		}
2183 		*out_sid = c->sid[0];
2184 	} else {
2185 		*out_sid = SECINITSID_PORT;
2186 	}
2187 
2188 out:
2189 	read_unlock(&policy_rwlock);
2190 	return rc;
2191 }
2192 
2193 /**
2194  * security_netif_sid - Obtain the SID for a network interface.
2195  * @name: interface name
2196  * @if_sid: interface SID
2197  */
security_netif_sid(char * name,u32 * if_sid)2198 int security_netif_sid(char *name, u32 *if_sid)
2199 {
2200 	int rc = 0;
2201 	struct ocontext *c;
2202 
2203 	read_lock(&policy_rwlock);
2204 
2205 	c = policydb.ocontexts[OCON_NETIF];
2206 	while (c) {
2207 		if (strcmp(name, c->u.name) == 0)
2208 			break;
2209 		c = c->next;
2210 	}
2211 
2212 	if (c) {
2213 		if (!c->sid[0] || !c->sid[1]) {
2214 			rc = sidtab_context_to_sid(&sidtab,
2215 						  &c->context[0],
2216 						  &c->sid[0]);
2217 			if (rc)
2218 				goto out;
2219 			rc = sidtab_context_to_sid(&sidtab,
2220 						   &c->context[1],
2221 						   &c->sid[1]);
2222 			if (rc)
2223 				goto out;
2224 		}
2225 		*if_sid = c->sid[0];
2226 	} else
2227 		*if_sid = SECINITSID_NETIF;
2228 
2229 out:
2230 	read_unlock(&policy_rwlock);
2231 	return rc;
2232 }
2233 
match_ipv6_addrmask(u32 * input,u32 * addr,u32 * mask)2234 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2235 {
2236 	int i, fail = 0;
2237 
2238 	for (i = 0; i < 4; i++)
2239 		if (addr[i] != (input[i] & mask[i])) {
2240 			fail = 1;
2241 			break;
2242 		}
2243 
2244 	return !fail;
2245 }
2246 
2247 /**
2248  * security_node_sid - Obtain the SID for a node (host).
2249  * @domain: communication domain aka address family
2250  * @addrp: address
2251  * @addrlen: address length in bytes
2252  * @out_sid: security identifier
2253  */
security_node_sid(u16 domain,void * addrp,u32 addrlen,u32 * out_sid)2254 int security_node_sid(u16 domain,
2255 		      void *addrp,
2256 		      u32 addrlen,
2257 		      u32 *out_sid)
2258 {
2259 	int rc;
2260 	struct ocontext *c;
2261 
2262 	read_lock(&policy_rwlock);
2263 
2264 	switch (domain) {
2265 	case AF_INET: {
2266 		u32 addr;
2267 
2268 		rc = -EINVAL;
2269 		if (addrlen != sizeof(u32))
2270 			goto out;
2271 
2272 		addr = *((u32 *)addrp);
2273 
2274 		c = policydb.ocontexts[OCON_NODE];
2275 		while (c) {
2276 			if (c->u.node.addr == (addr & c->u.node.mask))
2277 				break;
2278 			c = c->next;
2279 		}
2280 		break;
2281 	}
2282 
2283 	case AF_INET6:
2284 		rc = -EINVAL;
2285 		if (addrlen != sizeof(u64) * 2)
2286 			goto out;
2287 		c = policydb.ocontexts[OCON_NODE6];
2288 		while (c) {
2289 			if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2290 						c->u.node6.mask))
2291 				break;
2292 			c = c->next;
2293 		}
2294 		break;
2295 
2296 	default:
2297 		rc = 0;
2298 		*out_sid = SECINITSID_NODE;
2299 		goto out;
2300 	}
2301 
2302 	if (c) {
2303 		if (!c->sid[0]) {
2304 			rc = sidtab_context_to_sid(&sidtab,
2305 						   &c->context[0],
2306 						   &c->sid[0]);
2307 			if (rc)
2308 				goto out;
2309 		}
2310 		*out_sid = c->sid[0];
2311 	} else {
2312 		*out_sid = SECINITSID_NODE;
2313 	}
2314 
2315 	rc = 0;
2316 out:
2317 	read_unlock(&policy_rwlock);
2318 	return rc;
2319 }
2320 
2321 #define SIDS_NEL 25
2322 
2323 /**
2324  * security_get_user_sids - Obtain reachable SIDs for a user.
2325  * @fromsid: starting SID
2326  * @username: username
2327  * @sids: array of reachable SIDs for user
2328  * @nel: number of elements in @sids
2329  *
2330  * Generate the set of SIDs for legal security contexts
2331  * for a given user that can be reached by @fromsid.
2332  * Set *@sids to point to a dynamically allocated
2333  * array containing the set of SIDs.  Set *@nel to the
2334  * number of elements in the array.
2335  */
2336 
security_get_user_sids(u32 fromsid,char * username,u32 ** sids,u32 * nel)2337 int security_get_user_sids(u32 fromsid,
2338 			   char *username,
2339 			   u32 **sids,
2340 			   u32 *nel)
2341 {
2342 	struct context *fromcon, usercon;
2343 	u32 *mysids = NULL, *mysids2, sid;
2344 	u32 mynel = 0, maxnel = SIDS_NEL;
2345 	struct user_datum *user;
2346 	struct role_datum *role;
2347 	struct ebitmap_node *rnode, *tnode;
2348 	int rc = 0, i, j;
2349 
2350 	*sids = NULL;
2351 	*nel = 0;
2352 
2353 	if (!ss_initialized)
2354 		goto out;
2355 
2356 	read_lock(&policy_rwlock);
2357 
2358 	context_init(&usercon);
2359 
2360 	rc = -EINVAL;
2361 	fromcon = sidtab_search(&sidtab, fromsid);
2362 	if (!fromcon)
2363 		goto out_unlock;
2364 
2365 	rc = -EINVAL;
2366 	user = hashtab_search(policydb.p_users.table, username);
2367 	if (!user)
2368 		goto out_unlock;
2369 
2370 	usercon.user = user->value;
2371 
2372 	rc = -ENOMEM;
2373 	mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2374 	if (!mysids)
2375 		goto out_unlock;
2376 
2377 	ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2378 		role = policydb.role_val_to_struct[i];
2379 		usercon.role = i + 1;
2380 		ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2381 			usercon.type = j + 1;
2382 
2383 			if (mls_setup_user_range(fromcon, user, &usercon))
2384 				continue;
2385 
2386 			rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2387 			if (rc)
2388 				goto out_unlock;
2389 			if (mynel < maxnel) {
2390 				mysids[mynel++] = sid;
2391 			} else {
2392 				rc = -ENOMEM;
2393 				maxnel += SIDS_NEL;
2394 				mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2395 				if (!mysids2)
2396 					goto out_unlock;
2397 				memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2398 				kfree(mysids);
2399 				mysids = mysids2;
2400 				mysids[mynel++] = sid;
2401 			}
2402 		}
2403 	}
2404 	rc = 0;
2405 out_unlock:
2406 	read_unlock(&policy_rwlock);
2407 	if (rc || !mynel) {
2408 		kfree(mysids);
2409 		goto out;
2410 	}
2411 
2412 	rc = -ENOMEM;
2413 	mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2414 	if (!mysids2) {
2415 		kfree(mysids);
2416 		goto out;
2417 	}
2418 	for (i = 0, j = 0; i < mynel; i++) {
2419 		struct av_decision dummy_avd;
2420 		rc = avc_has_perm_noaudit(fromsid, mysids[i],
2421 					  SECCLASS_PROCESS, /* kernel value */
2422 					  PROCESS__TRANSITION, AVC_STRICT,
2423 					  &dummy_avd);
2424 		if (!rc)
2425 			mysids2[j++] = mysids[i];
2426 		cond_resched();
2427 	}
2428 	rc = 0;
2429 	kfree(mysids);
2430 	*sids = mysids2;
2431 	*nel = j;
2432 out:
2433 	return rc;
2434 }
2435 
2436 /**
2437  * security_genfs_sid - Obtain a SID for a file in a filesystem
2438  * @fstype: filesystem type
2439  * @path: path from root of mount
2440  * @sclass: file security class
2441  * @sid: SID for path
2442  *
2443  * Obtain a SID to use for a file in a filesystem that
2444  * cannot support xattr or use a fixed labeling behavior like
2445  * transition SIDs or task SIDs.
2446  */
security_genfs_sid(const char * fstype,char * path,u16 orig_sclass,u32 * sid)2447 int security_genfs_sid(const char *fstype,
2448 		       char *path,
2449 		       u16 orig_sclass,
2450 		       u32 *sid)
2451 {
2452 	int len;
2453 	u16 sclass;
2454 	struct genfs *genfs;
2455 	struct ocontext *c;
2456 	int rc, cmp = 0;
2457 
2458 	while (path[0] == '/' && path[1] == '/')
2459 		path++;
2460 
2461 	read_lock(&policy_rwlock);
2462 
2463 	sclass = unmap_class(orig_sclass);
2464 	*sid = SECINITSID_UNLABELED;
2465 
2466 	for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2467 		cmp = strcmp(fstype, genfs->fstype);
2468 		if (cmp <= 0)
2469 			break;
2470 	}
2471 
2472 	rc = -ENOENT;
2473 	if (!genfs || cmp)
2474 		goto out;
2475 
2476 	for (c = genfs->head; c; c = c->next) {
2477 		len = strlen(c->u.name);
2478 		if ((!c->v.sclass || sclass == c->v.sclass) &&
2479 		    (strncmp(c->u.name, path, len) == 0))
2480 			break;
2481 	}
2482 
2483 	rc = -ENOENT;
2484 	if (!c)
2485 		goto out;
2486 
2487 	if (!c->sid[0]) {
2488 		rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2489 		if (rc)
2490 			goto out;
2491 	}
2492 
2493 	*sid = c->sid[0];
2494 	rc = 0;
2495 out:
2496 	read_unlock(&policy_rwlock);
2497 	return rc;
2498 }
2499 
2500 /**
2501  * security_fs_use - Determine how to handle labeling for a filesystem.
2502  * @fstype: filesystem type
2503  * @behavior: labeling behavior
2504  * @sid: SID for filesystem (superblock)
2505  */
security_fs_use(const char * fstype,unsigned int * behavior,u32 * sid)2506 int security_fs_use(
2507 	const char *fstype,
2508 	unsigned int *behavior,
2509 	u32 *sid)
2510 {
2511 	int rc = 0;
2512 	struct ocontext *c;
2513 
2514 	read_lock(&policy_rwlock);
2515 
2516 	c = policydb.ocontexts[OCON_FSUSE];
2517 	while (c) {
2518 		if (strcmp(fstype, c->u.name) == 0)
2519 			break;
2520 		c = c->next;
2521 	}
2522 
2523 	if (c) {
2524 		*behavior = c->v.behavior;
2525 		if (!c->sid[0]) {
2526 			rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2527 						   &c->sid[0]);
2528 			if (rc)
2529 				goto out;
2530 		}
2531 		*sid = c->sid[0];
2532 	} else {
2533 		rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2534 		if (rc) {
2535 			*behavior = SECURITY_FS_USE_NONE;
2536 			rc = 0;
2537 		} else {
2538 			*behavior = SECURITY_FS_USE_GENFS;
2539 		}
2540 	}
2541 
2542 out:
2543 	read_unlock(&policy_rwlock);
2544 	return rc;
2545 }
2546 
security_get_bools(int * len,char *** names,int ** values)2547 int security_get_bools(int *len, char ***names, int **values)
2548 {
2549 	int i, rc;
2550 
2551 	read_lock(&policy_rwlock);
2552 	*names = NULL;
2553 	*values = NULL;
2554 
2555 	rc = 0;
2556 	*len = policydb.p_bools.nprim;
2557 	if (!*len)
2558 		goto out;
2559 
2560 	rc = -ENOMEM;
2561 	*names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2562 	if (!*names)
2563 		goto err;
2564 
2565 	rc = -ENOMEM;
2566 	*values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2567 	if (!*values)
2568 		goto err;
2569 
2570 	for (i = 0; i < *len; i++) {
2571 		size_t name_len;
2572 
2573 		(*values)[i] = policydb.bool_val_to_struct[i]->state;
2574 		name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2575 
2576 		rc = -ENOMEM;
2577 		(*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2578 		if (!(*names)[i])
2579 			goto err;
2580 
2581 		strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2582 		(*names)[i][name_len - 1] = 0;
2583 	}
2584 	rc = 0;
2585 out:
2586 	read_unlock(&policy_rwlock);
2587 	return rc;
2588 err:
2589 	if (*names) {
2590 		for (i = 0; i < *len; i++)
2591 			kfree((*names)[i]);
2592 	}
2593 	kfree(*values);
2594 	goto out;
2595 }
2596 
2597 
security_set_bools(int len,int * values)2598 int security_set_bools(int len, int *values)
2599 {
2600 	int i, rc;
2601 	int lenp, seqno = 0;
2602 	struct cond_node *cur;
2603 
2604 	write_lock_irq(&policy_rwlock);
2605 
2606 	rc = -EFAULT;
2607 	lenp = policydb.p_bools.nprim;
2608 	if (len != lenp)
2609 		goto out;
2610 
2611 	for (i = 0; i < len; i++) {
2612 		if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2613 			audit_log(current->audit_context, GFP_ATOMIC,
2614 				AUDIT_MAC_CONFIG_CHANGE,
2615 				"bool=%s val=%d old_val=%d auid=%u ses=%u",
2616 				sym_name(&policydb, SYM_BOOLS, i),
2617 				!!values[i],
2618 				policydb.bool_val_to_struct[i]->state,
2619 				audit_get_loginuid(current),
2620 				audit_get_sessionid(current));
2621 		}
2622 		if (values[i])
2623 			policydb.bool_val_to_struct[i]->state = 1;
2624 		else
2625 			policydb.bool_val_to_struct[i]->state = 0;
2626 	}
2627 
2628 	for (cur = policydb.cond_list; cur; cur = cur->next) {
2629 		rc = evaluate_cond_node(&policydb, cur);
2630 		if (rc)
2631 			goto out;
2632 	}
2633 
2634 	seqno = ++latest_granting;
2635 	rc = 0;
2636 out:
2637 	write_unlock_irq(&policy_rwlock);
2638 	if (!rc) {
2639 		avc_ss_reset(seqno);
2640 		selnl_notify_policyload(seqno);
2641 		selinux_status_update_policyload(seqno);
2642 		selinux_xfrm_notify_policyload();
2643 	}
2644 	return rc;
2645 }
2646 
security_get_bool_value(int bool)2647 int security_get_bool_value(int bool)
2648 {
2649 	int rc;
2650 	int len;
2651 
2652 	read_lock(&policy_rwlock);
2653 
2654 	rc = -EFAULT;
2655 	len = policydb.p_bools.nprim;
2656 	if (bool >= len)
2657 		goto out;
2658 
2659 	rc = policydb.bool_val_to_struct[bool]->state;
2660 out:
2661 	read_unlock(&policy_rwlock);
2662 	return rc;
2663 }
2664 
security_preserve_bools(struct policydb * p)2665 static int security_preserve_bools(struct policydb *p)
2666 {
2667 	int rc, nbools = 0, *bvalues = NULL, i;
2668 	char **bnames = NULL;
2669 	struct cond_bool_datum *booldatum;
2670 	struct cond_node *cur;
2671 
2672 	rc = security_get_bools(&nbools, &bnames, &bvalues);
2673 	if (rc)
2674 		goto out;
2675 	for (i = 0; i < nbools; i++) {
2676 		booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2677 		if (booldatum)
2678 			booldatum->state = bvalues[i];
2679 	}
2680 	for (cur = p->cond_list; cur; cur = cur->next) {
2681 		rc = evaluate_cond_node(p, cur);
2682 		if (rc)
2683 			goto out;
2684 	}
2685 
2686 out:
2687 	if (bnames) {
2688 		for (i = 0; i < nbools; i++)
2689 			kfree(bnames[i]);
2690 	}
2691 	kfree(bnames);
2692 	kfree(bvalues);
2693 	return rc;
2694 }
2695 
2696 /*
2697  * security_sid_mls_copy() - computes a new sid based on the given
2698  * sid and the mls portion of mls_sid.
2699  */
security_sid_mls_copy(u32 sid,u32 mls_sid,u32 * new_sid)2700 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2701 {
2702 	struct context *context1;
2703 	struct context *context2;
2704 	struct context newcon;
2705 	char *s;
2706 	u32 len;
2707 	int rc;
2708 
2709 	rc = 0;
2710 	if (!ss_initialized || !policydb.mls_enabled) {
2711 		*new_sid = sid;
2712 		goto out;
2713 	}
2714 
2715 	context_init(&newcon);
2716 
2717 	read_lock(&policy_rwlock);
2718 
2719 	rc = -EINVAL;
2720 	context1 = sidtab_search(&sidtab, sid);
2721 	if (!context1) {
2722 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2723 			__func__, sid);
2724 		goto out_unlock;
2725 	}
2726 
2727 	rc = -EINVAL;
2728 	context2 = sidtab_search(&sidtab, mls_sid);
2729 	if (!context2) {
2730 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2731 			__func__, mls_sid);
2732 		goto out_unlock;
2733 	}
2734 
2735 	newcon.user = context1->user;
2736 	newcon.role = context1->role;
2737 	newcon.type = context1->type;
2738 	rc = mls_context_cpy(&newcon, context2);
2739 	if (rc)
2740 		goto out_unlock;
2741 
2742 	/* Check the validity of the new context. */
2743 	if (!policydb_context_isvalid(&policydb, &newcon)) {
2744 		rc = convert_context_handle_invalid_context(&newcon);
2745 		if (rc) {
2746 			if (!context_struct_to_string(&newcon, &s, &len)) {
2747 				audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2748 					  "security_sid_mls_copy: invalid context %s", s);
2749 				kfree(s);
2750 			}
2751 			goto out_unlock;
2752 		}
2753 	}
2754 
2755 	rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2756 out_unlock:
2757 	read_unlock(&policy_rwlock);
2758 	context_destroy(&newcon);
2759 out:
2760 	return rc;
2761 }
2762 
2763 /**
2764  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2765  * @nlbl_sid: NetLabel SID
2766  * @nlbl_type: NetLabel labeling protocol type
2767  * @xfrm_sid: XFRM SID
2768  *
2769  * Description:
2770  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2771  * resolved into a single SID it is returned via @peer_sid and the function
2772  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2773  * returns a negative value.  A table summarizing the behavior is below:
2774  *
2775  *                                 | function return |      @sid
2776  *   ------------------------------+-----------------+-----------------
2777  *   no peer labels                |        0        |    SECSID_NULL
2778  *   single peer label             |        0        |    <peer_label>
2779  *   multiple, consistent labels   |        0        |    <peer_label>
2780  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2781  *
2782  */
security_net_peersid_resolve(u32 nlbl_sid,u32 nlbl_type,u32 xfrm_sid,u32 * peer_sid)2783 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2784 				 u32 xfrm_sid,
2785 				 u32 *peer_sid)
2786 {
2787 	int rc;
2788 	struct context *nlbl_ctx;
2789 	struct context *xfrm_ctx;
2790 
2791 	*peer_sid = SECSID_NULL;
2792 
2793 	/* handle the common (which also happens to be the set of easy) cases
2794 	 * right away, these two if statements catch everything involving a
2795 	 * single or absent peer SID/label */
2796 	if (xfrm_sid == SECSID_NULL) {
2797 		*peer_sid = nlbl_sid;
2798 		return 0;
2799 	}
2800 	/* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2801 	 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2802 	 * is present */
2803 	if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2804 		*peer_sid = xfrm_sid;
2805 		return 0;
2806 	}
2807 
2808 	/* we don't need to check ss_initialized here since the only way both
2809 	 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2810 	 * security server was initialized and ss_initialized was true */
2811 	if (!policydb.mls_enabled)
2812 		return 0;
2813 
2814 	read_lock(&policy_rwlock);
2815 
2816 	rc = -EINVAL;
2817 	nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2818 	if (!nlbl_ctx) {
2819 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2820 		       __func__, nlbl_sid);
2821 		goto out;
2822 	}
2823 	rc = -EINVAL;
2824 	xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2825 	if (!xfrm_ctx) {
2826 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2827 		       __func__, xfrm_sid);
2828 		goto out;
2829 	}
2830 	rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2831 	if (rc)
2832 		goto out;
2833 
2834 	/* at present NetLabel SIDs/labels really only carry MLS
2835 	 * information so if the MLS portion of the NetLabel SID
2836 	 * matches the MLS portion of the labeled XFRM SID/label
2837 	 * then pass along the XFRM SID as it is the most
2838 	 * expressive */
2839 	*peer_sid = xfrm_sid;
2840 out:
2841 	read_unlock(&policy_rwlock);
2842 	return rc;
2843 }
2844 
get_classes_callback(void * k,void * d,void * args)2845 static int get_classes_callback(void *k, void *d, void *args)
2846 {
2847 	struct class_datum *datum = d;
2848 	char *name = k, **classes = args;
2849 	int value = datum->value - 1;
2850 
2851 	classes[value] = kstrdup(name, GFP_ATOMIC);
2852 	if (!classes[value])
2853 		return -ENOMEM;
2854 
2855 	return 0;
2856 }
2857 
security_get_classes(char *** classes,int * nclasses)2858 int security_get_classes(char ***classes, int *nclasses)
2859 {
2860 	int rc;
2861 
2862 	read_lock(&policy_rwlock);
2863 
2864 	rc = -ENOMEM;
2865 	*nclasses = policydb.p_classes.nprim;
2866 	*classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2867 	if (!*classes)
2868 		goto out;
2869 
2870 	rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2871 			*classes);
2872 	if (rc) {
2873 		int i;
2874 		for (i = 0; i < *nclasses; i++)
2875 			kfree((*classes)[i]);
2876 		kfree(*classes);
2877 	}
2878 
2879 out:
2880 	read_unlock(&policy_rwlock);
2881 	return rc;
2882 }
2883 
get_permissions_callback(void * k,void * d,void * args)2884 static int get_permissions_callback(void *k, void *d, void *args)
2885 {
2886 	struct perm_datum *datum = d;
2887 	char *name = k, **perms = args;
2888 	int value = datum->value - 1;
2889 
2890 	perms[value] = kstrdup(name, GFP_ATOMIC);
2891 	if (!perms[value])
2892 		return -ENOMEM;
2893 
2894 	return 0;
2895 }
2896 
security_get_permissions(char * class,char *** perms,int * nperms)2897 int security_get_permissions(char *class, char ***perms, int *nperms)
2898 {
2899 	int rc, i;
2900 	struct class_datum *match;
2901 
2902 	read_lock(&policy_rwlock);
2903 
2904 	rc = -EINVAL;
2905 	match = hashtab_search(policydb.p_classes.table, class);
2906 	if (!match) {
2907 		printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2908 			__func__, class);
2909 		goto out;
2910 	}
2911 
2912 	rc = -ENOMEM;
2913 	*nperms = match->permissions.nprim;
2914 	*perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2915 	if (!*perms)
2916 		goto out;
2917 
2918 	if (match->comdatum) {
2919 		rc = hashtab_map(match->comdatum->permissions.table,
2920 				get_permissions_callback, *perms);
2921 		if (rc)
2922 			goto err;
2923 	}
2924 
2925 	rc = hashtab_map(match->permissions.table, get_permissions_callback,
2926 			*perms);
2927 	if (rc)
2928 		goto err;
2929 
2930 out:
2931 	read_unlock(&policy_rwlock);
2932 	return rc;
2933 
2934 err:
2935 	read_unlock(&policy_rwlock);
2936 	for (i = 0; i < *nperms; i++)
2937 		kfree((*perms)[i]);
2938 	kfree(*perms);
2939 	return rc;
2940 }
2941 
security_get_reject_unknown(void)2942 int security_get_reject_unknown(void)
2943 {
2944 	return policydb.reject_unknown;
2945 }
2946 
security_get_allow_unknown(void)2947 int security_get_allow_unknown(void)
2948 {
2949 	return policydb.allow_unknown;
2950 }
2951 
2952 /**
2953  * security_policycap_supported - Check for a specific policy capability
2954  * @req_cap: capability
2955  *
2956  * Description:
2957  * This function queries the currently loaded policy to see if it supports the
2958  * capability specified by @req_cap.  Returns true (1) if the capability is
2959  * supported, false (0) if it isn't supported.
2960  *
2961  */
security_policycap_supported(unsigned int req_cap)2962 int security_policycap_supported(unsigned int req_cap)
2963 {
2964 	int rc;
2965 
2966 	read_lock(&policy_rwlock);
2967 	rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2968 	read_unlock(&policy_rwlock);
2969 
2970 	return rc;
2971 }
2972 
2973 struct selinux_audit_rule {
2974 	u32 au_seqno;
2975 	struct context au_ctxt;
2976 };
2977 
selinux_audit_rule_free(void * vrule)2978 void selinux_audit_rule_free(void *vrule)
2979 {
2980 	struct selinux_audit_rule *rule = vrule;
2981 
2982 	if (rule) {
2983 		context_destroy(&rule->au_ctxt);
2984 		kfree(rule);
2985 	}
2986 }
2987 
selinux_audit_rule_init(u32 field,u32 op,char * rulestr,void ** vrule)2988 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2989 {
2990 	struct selinux_audit_rule *tmprule;
2991 	struct role_datum *roledatum;
2992 	struct type_datum *typedatum;
2993 	struct user_datum *userdatum;
2994 	struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2995 	int rc = 0;
2996 
2997 	*rule = NULL;
2998 
2999 	if (!ss_initialized)
3000 		return -EOPNOTSUPP;
3001 
3002 	switch (field) {
3003 	case AUDIT_SUBJ_USER:
3004 	case AUDIT_SUBJ_ROLE:
3005 	case AUDIT_SUBJ_TYPE:
3006 	case AUDIT_OBJ_USER:
3007 	case AUDIT_OBJ_ROLE:
3008 	case AUDIT_OBJ_TYPE:
3009 		/* only 'equals' and 'not equals' fit user, role, and type */
3010 		if (op != Audit_equal && op != Audit_not_equal)
3011 			return -EINVAL;
3012 		break;
3013 	case AUDIT_SUBJ_SEN:
3014 	case AUDIT_SUBJ_CLR:
3015 	case AUDIT_OBJ_LEV_LOW:
3016 	case AUDIT_OBJ_LEV_HIGH:
3017 		/* we do not allow a range, indicated by the presence of '-' */
3018 		if (strchr(rulestr, '-'))
3019 			return -EINVAL;
3020 		break;
3021 	default:
3022 		/* only the above fields are valid */
3023 		return -EINVAL;
3024 	}
3025 
3026 	tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3027 	if (!tmprule)
3028 		return -ENOMEM;
3029 
3030 	context_init(&tmprule->au_ctxt);
3031 
3032 	read_lock(&policy_rwlock);
3033 
3034 	tmprule->au_seqno = latest_granting;
3035 
3036 	switch (field) {
3037 	case AUDIT_SUBJ_USER:
3038 	case AUDIT_OBJ_USER:
3039 		rc = -EINVAL;
3040 		userdatum = hashtab_search(policydb.p_users.table, rulestr);
3041 		if (!userdatum)
3042 			goto out;
3043 		tmprule->au_ctxt.user = userdatum->value;
3044 		break;
3045 	case AUDIT_SUBJ_ROLE:
3046 	case AUDIT_OBJ_ROLE:
3047 		rc = -EINVAL;
3048 		roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3049 		if (!roledatum)
3050 			goto out;
3051 		tmprule->au_ctxt.role = roledatum->value;
3052 		break;
3053 	case AUDIT_SUBJ_TYPE:
3054 	case AUDIT_OBJ_TYPE:
3055 		rc = -EINVAL;
3056 		typedatum = hashtab_search(policydb.p_types.table, rulestr);
3057 		if (!typedatum)
3058 			goto out;
3059 		tmprule->au_ctxt.type = typedatum->value;
3060 		break;
3061 	case AUDIT_SUBJ_SEN:
3062 	case AUDIT_SUBJ_CLR:
3063 	case AUDIT_OBJ_LEV_LOW:
3064 	case AUDIT_OBJ_LEV_HIGH:
3065 		rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3066 		if (rc)
3067 			goto out;
3068 		break;
3069 	}
3070 	rc = 0;
3071 out:
3072 	read_unlock(&policy_rwlock);
3073 
3074 	if (rc) {
3075 		selinux_audit_rule_free(tmprule);
3076 		tmprule = NULL;
3077 	}
3078 
3079 	*rule = tmprule;
3080 
3081 	return rc;
3082 }
3083 
3084 /* Check to see if the rule contains any selinux fields */
selinux_audit_rule_known(struct audit_krule * rule)3085 int selinux_audit_rule_known(struct audit_krule *rule)
3086 {
3087 	int i;
3088 
3089 	for (i = 0; i < rule->field_count; i++) {
3090 		struct audit_field *f = &rule->fields[i];
3091 		switch (f->type) {
3092 		case AUDIT_SUBJ_USER:
3093 		case AUDIT_SUBJ_ROLE:
3094 		case AUDIT_SUBJ_TYPE:
3095 		case AUDIT_SUBJ_SEN:
3096 		case AUDIT_SUBJ_CLR:
3097 		case AUDIT_OBJ_USER:
3098 		case AUDIT_OBJ_ROLE:
3099 		case AUDIT_OBJ_TYPE:
3100 		case AUDIT_OBJ_LEV_LOW:
3101 		case AUDIT_OBJ_LEV_HIGH:
3102 			return 1;
3103 		}
3104 	}
3105 
3106 	return 0;
3107 }
3108 
selinux_audit_rule_match(u32 sid,u32 field,u32 op,void * vrule,struct audit_context * actx)3109 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3110 			     struct audit_context *actx)
3111 {
3112 	struct context *ctxt;
3113 	struct mls_level *level;
3114 	struct selinux_audit_rule *rule = vrule;
3115 	int match = 0;
3116 
3117 	if (!rule) {
3118 		audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
3119 			  "selinux_audit_rule_match: missing rule\n");
3120 		return -ENOENT;
3121 	}
3122 
3123 	read_lock(&policy_rwlock);
3124 
3125 	if (rule->au_seqno < latest_granting) {
3126 		audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
3127 			  "selinux_audit_rule_match: stale rule\n");
3128 		match = -ESTALE;
3129 		goto out;
3130 	}
3131 
3132 	ctxt = sidtab_search(&sidtab, sid);
3133 	if (!ctxt) {
3134 		audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
3135 			  "selinux_audit_rule_match: unrecognized SID %d\n",
3136 			  sid);
3137 		match = -ENOENT;
3138 		goto out;
3139 	}
3140 
3141 	/* a field/op pair that is not caught here will simply fall through
3142 	   without a match */
3143 	switch (field) {
3144 	case AUDIT_SUBJ_USER:
3145 	case AUDIT_OBJ_USER:
3146 		switch (op) {
3147 		case Audit_equal:
3148 			match = (ctxt->user == rule->au_ctxt.user);
3149 			break;
3150 		case Audit_not_equal:
3151 			match = (ctxt->user != rule->au_ctxt.user);
3152 			break;
3153 		}
3154 		break;
3155 	case AUDIT_SUBJ_ROLE:
3156 	case AUDIT_OBJ_ROLE:
3157 		switch (op) {
3158 		case Audit_equal:
3159 			match = (ctxt->role == rule->au_ctxt.role);
3160 			break;
3161 		case Audit_not_equal:
3162 			match = (ctxt->role != rule->au_ctxt.role);
3163 			break;
3164 		}
3165 		break;
3166 	case AUDIT_SUBJ_TYPE:
3167 	case AUDIT_OBJ_TYPE:
3168 		switch (op) {
3169 		case Audit_equal:
3170 			match = (ctxt->type == rule->au_ctxt.type);
3171 			break;
3172 		case Audit_not_equal:
3173 			match = (ctxt->type != rule->au_ctxt.type);
3174 			break;
3175 		}
3176 		break;
3177 	case AUDIT_SUBJ_SEN:
3178 	case AUDIT_SUBJ_CLR:
3179 	case AUDIT_OBJ_LEV_LOW:
3180 	case AUDIT_OBJ_LEV_HIGH:
3181 		level = ((field == AUDIT_SUBJ_SEN ||
3182 			  field == AUDIT_OBJ_LEV_LOW) ?
3183 			 &ctxt->range.level[0] : &ctxt->range.level[1]);
3184 		switch (op) {
3185 		case Audit_equal:
3186 			match = mls_level_eq(&rule->au_ctxt.range.level[0],
3187 					     level);
3188 			break;
3189 		case Audit_not_equal:
3190 			match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3191 					      level);
3192 			break;
3193 		case Audit_lt:
3194 			match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3195 					       level) &&
3196 				 !mls_level_eq(&rule->au_ctxt.range.level[0],
3197 					       level));
3198 			break;
3199 		case Audit_le:
3200 			match = mls_level_dom(&rule->au_ctxt.range.level[0],
3201 					      level);
3202 			break;
3203 		case Audit_gt:
3204 			match = (mls_level_dom(level,
3205 					      &rule->au_ctxt.range.level[0]) &&
3206 				 !mls_level_eq(level,
3207 					       &rule->au_ctxt.range.level[0]));
3208 			break;
3209 		case Audit_ge:
3210 			match = mls_level_dom(level,
3211 					      &rule->au_ctxt.range.level[0]);
3212 			break;
3213 		}
3214 	}
3215 
3216 out:
3217 	read_unlock(&policy_rwlock);
3218 	return match;
3219 }
3220 
3221 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3222 
aurule_avc_callback(u32 event,u32 ssid,u32 tsid,u16 class,u32 perms,u32 * retained)3223 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
3224 			       u16 class, u32 perms, u32 *retained)
3225 {
3226 	int err = 0;
3227 
3228 	if (event == AVC_CALLBACK_RESET && aurule_callback)
3229 		err = aurule_callback();
3230 	return err;
3231 }
3232 
aurule_init(void)3233 static int __init aurule_init(void)
3234 {
3235 	int err;
3236 
3237 	err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
3238 			       SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
3239 	if (err)
3240 		panic("avc_add_callback() failed, error %d\n", err);
3241 
3242 	return err;
3243 }
3244 __initcall(aurule_init);
3245 
3246 #ifdef CONFIG_NETLABEL
3247 /**
3248  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3249  * @secattr: the NetLabel packet security attributes
3250  * @sid: the SELinux SID
3251  *
3252  * Description:
3253  * Attempt to cache the context in @ctx, which was derived from the packet in
3254  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3255  * already been initialized.
3256  *
3257  */
security_netlbl_cache_add(struct netlbl_lsm_secattr * secattr,u32 sid)3258 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3259 				      u32 sid)
3260 {
3261 	u32 *sid_cache;
3262 
3263 	sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3264 	if (sid_cache == NULL)
3265 		return;
3266 	secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3267 	if (secattr->cache == NULL) {
3268 		kfree(sid_cache);
3269 		return;
3270 	}
3271 
3272 	*sid_cache = sid;
3273 	secattr->cache->free = kfree;
3274 	secattr->cache->data = sid_cache;
3275 	secattr->flags |= NETLBL_SECATTR_CACHE;
3276 }
3277 
3278 /**
3279  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3280  * @secattr: the NetLabel packet security attributes
3281  * @sid: the SELinux SID
3282  *
3283  * Description:
3284  * Convert the given NetLabel security attributes in @secattr into a
3285  * SELinux SID.  If the @secattr field does not contain a full SELinux
3286  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3287  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3288  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3289  * conversion for future lookups.  Returns zero on success, negative values on
3290  * failure.
3291  *
3292  */
security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr * secattr,u32 * sid)3293 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3294 				   u32 *sid)
3295 {
3296 	int rc;
3297 	struct context *ctx;
3298 	struct context ctx_new;
3299 
3300 	if (!ss_initialized) {
3301 		*sid = SECSID_NULL;
3302 		return 0;
3303 	}
3304 
3305 	read_lock(&policy_rwlock);
3306 
3307 	if (secattr->flags & NETLBL_SECATTR_CACHE)
3308 		*sid = *(u32 *)secattr->cache->data;
3309 	else if (secattr->flags & NETLBL_SECATTR_SECID)
3310 		*sid = secattr->attr.secid;
3311 	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3312 		rc = -EIDRM;
3313 		ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3314 		if (ctx == NULL)
3315 			goto out;
3316 
3317 		context_init(&ctx_new);
3318 		ctx_new.user = ctx->user;
3319 		ctx_new.role = ctx->role;
3320 		ctx_new.type = ctx->type;
3321 		mls_import_netlbl_lvl(&ctx_new, secattr);
3322 		if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3323 			rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3324 						   secattr->attr.mls.cat);
3325 			if (rc)
3326 				goto out;
3327 			memcpy(&ctx_new.range.level[1].cat,
3328 			       &ctx_new.range.level[0].cat,
3329 			       sizeof(ctx_new.range.level[0].cat));
3330 		}
3331 		rc = -EIDRM;
3332 		if (!mls_context_isvalid(&policydb, &ctx_new))
3333 			goto out_free;
3334 
3335 		rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3336 		if (rc)
3337 			goto out_free;
3338 
3339 		security_netlbl_cache_add(secattr, *sid);
3340 
3341 		ebitmap_destroy(&ctx_new.range.level[0].cat);
3342 	} else
3343 		*sid = SECSID_NULL;
3344 
3345 	read_unlock(&policy_rwlock);
3346 	return 0;
3347 out_free:
3348 	ebitmap_destroy(&ctx_new.range.level[0].cat);
3349 out:
3350 	read_unlock(&policy_rwlock);
3351 	return rc;
3352 }
3353 
3354 /**
3355  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3356  * @sid: the SELinux SID
3357  * @secattr: the NetLabel packet security attributes
3358  *
3359  * Description:
3360  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3361  * Returns zero on success, negative values on failure.
3362  *
3363  */
security_netlbl_sid_to_secattr(u32 sid,struct netlbl_lsm_secattr * secattr)3364 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3365 {
3366 	int rc;
3367 	struct context *ctx;
3368 
3369 	if (!ss_initialized)
3370 		return 0;
3371 
3372 	read_lock(&policy_rwlock);
3373 
3374 	rc = -ENOENT;
3375 	ctx = sidtab_search(&sidtab, sid);
3376 	if (ctx == NULL)
3377 		goto out;
3378 
3379 	rc = -ENOMEM;
3380 	secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3381 				  GFP_ATOMIC);
3382 	if (secattr->domain == NULL)
3383 		goto out;
3384 
3385 	secattr->attr.secid = sid;
3386 	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3387 	mls_export_netlbl_lvl(ctx, secattr);
3388 	rc = mls_export_netlbl_cat(ctx, secattr);
3389 out:
3390 	read_unlock(&policy_rwlock);
3391 	return rc;
3392 }
3393 #endif /* CONFIG_NETLABEL */
3394 
3395 /**
3396  * security_read_policy - read the policy.
3397  * @data: binary policy data
3398  * @len: length of data in bytes
3399  *
3400  */
security_read_policy(void ** data,size_t * len)3401 int security_read_policy(void **data, size_t *len)
3402 {
3403 	int rc;
3404 	struct policy_file fp;
3405 
3406 	if (!ss_initialized)
3407 		return -EINVAL;
3408 
3409 	*len = security_policydb_len();
3410 
3411 	*data = vmalloc_user(*len);
3412 	if (!*data)
3413 		return -ENOMEM;
3414 
3415 	fp.data = *data;
3416 	fp.len = *len;
3417 
3418 	read_lock(&policy_rwlock);
3419 	rc = policydb_write(&policydb, &fp);
3420 	read_unlock(&policy_rwlock);
3421 
3422 	if (rc)
3423 		return rc;
3424 
3425 	*len = (unsigned long)fp.data - (unsigned long)*data;
3426 	return 0;
3427 
3428 }
3429