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1 /*
2  * Implementation of the security services.
3  *
4  * Authors : Stephen Smalley, <sds@tycho.nsa.gov>
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 /* Policy capability names */
74 char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = {
75 	"network_peer_controls",
76 	"open_perms",
77 	"extended_socket_class",
78 	"always_check_network",
79 	"cgroup_seclabel",
80 	"nnp_nosuid_transition"
81 };
82 
83 int selinux_android_netlink_route;
84 int selinux_policycap_netpeer;
85 int selinux_policycap_openperm;
86 int selinux_policycap_extsockclass;
87 int selinux_policycap_alwaysnetwork;
88 int selinux_policycap_cgroupseclabel;
89 int selinux_policycap_nnp_nosuid_transition;
90 
91 static DEFINE_RWLOCK(policy_rwlock);
92 
93 static struct sidtab sidtab;
94 struct policydb policydb;
95 int ss_initialized;
96 
97 /*
98  * The largest sequence number that has been used when
99  * providing an access decision to the access vector cache.
100  * The sequence number only changes when a policy change
101  * occurs.
102  */
103 static u32 latest_granting;
104 
105 /* Forward declaration. */
106 static int context_struct_to_string(struct context *context, char **scontext,
107 				    u32 *scontext_len);
108 
109 static void context_struct_compute_av(struct context *scontext,
110 					struct context *tcontext,
111 					u16 tclass,
112 					struct av_decision *avd,
113 					struct extended_perms *xperms);
114 
115 struct selinux_mapping {
116 	u16 value; /* policy value */
117 	unsigned num_perms;
118 	u32 perms[sizeof(u32) * 8];
119 };
120 
121 static struct selinux_mapping *current_mapping;
122 static u16 current_mapping_size;
123 
selinux_set_mapping(struct policydb * pol,struct security_class_mapping * map,struct selinux_mapping ** out_map_p,u16 * out_map_size)124 static int selinux_set_mapping(struct policydb *pol,
125 			       struct security_class_mapping *map,
126 			       struct selinux_mapping **out_map_p,
127 			       u16 *out_map_size)
128 {
129 	struct selinux_mapping *out_map = NULL;
130 	size_t size = sizeof(struct selinux_mapping);
131 	u16 i, j;
132 	unsigned k;
133 	bool print_unknown_handle = false;
134 
135 	/* Find number of classes in the input mapping */
136 	if (!map)
137 		return -EINVAL;
138 	i = 0;
139 	while (map[i].name)
140 		i++;
141 
142 	/* Allocate space for the class records, plus one for class zero */
143 	out_map = kcalloc(++i, size, GFP_ATOMIC);
144 	if (!out_map)
145 		return -ENOMEM;
146 
147 	/* Store the raw class and permission values */
148 	j = 0;
149 	while (map[j].name) {
150 		struct security_class_mapping *p_in = map + (j++);
151 		struct selinux_mapping *p_out = out_map + j;
152 
153 		/* An empty class string skips ahead */
154 		if (!strcmp(p_in->name, "")) {
155 			p_out->num_perms = 0;
156 			continue;
157 		}
158 
159 		p_out->value = string_to_security_class(pol, p_in->name);
160 		if (!p_out->value) {
161 			printk(KERN_INFO
162 			       "SELinux:  Class %s not defined in policy.\n",
163 			       p_in->name);
164 			if (pol->reject_unknown)
165 				goto err;
166 			p_out->num_perms = 0;
167 			print_unknown_handle = true;
168 			continue;
169 		}
170 
171 		k = 0;
172 		while (p_in->perms[k]) {
173 			/* An empty permission string skips ahead */
174 			if (!*p_in->perms[k]) {
175 				k++;
176 				continue;
177 			}
178 			p_out->perms[k] = string_to_av_perm(pol, p_out->value,
179 							    p_in->perms[k]);
180 			if (!p_out->perms[k]) {
181 				printk(KERN_INFO
182 				       "SELinux:  Permission %s in class %s not defined in policy.\n",
183 				       p_in->perms[k], p_in->name);
184 				if (pol->reject_unknown)
185 					goto err;
186 				print_unknown_handle = true;
187 			}
188 
189 			k++;
190 		}
191 		p_out->num_perms = k;
192 	}
193 
194 	if (print_unknown_handle)
195 		printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
196 		       pol->allow_unknown ? "allowed" : "denied");
197 
198 	*out_map_p = out_map;
199 	*out_map_size = i;
200 	return 0;
201 err:
202 	kfree(out_map);
203 	return -EINVAL;
204 }
205 
206 /*
207  * Get real, policy values from mapped values
208  */
209 
unmap_class(u16 tclass)210 static u16 unmap_class(u16 tclass)
211 {
212 	if (tclass < current_mapping_size)
213 		return current_mapping[tclass].value;
214 
215 	return tclass;
216 }
217 
218 /*
219  * Get kernel value for class from its policy value
220  */
map_class(u16 pol_value)221 static u16 map_class(u16 pol_value)
222 {
223 	u16 i;
224 
225 	for (i = 1; i < current_mapping_size; i++) {
226 		if (current_mapping[i].value == pol_value)
227 			return i;
228 	}
229 
230 	return SECCLASS_NULL;
231 }
232 
map_decision(u16 tclass,struct av_decision * avd,int allow_unknown)233 static void map_decision(u16 tclass, struct av_decision *avd,
234 			 int allow_unknown)
235 {
236 	if (tclass < current_mapping_size) {
237 		unsigned i, n = current_mapping[tclass].num_perms;
238 		u32 result;
239 
240 		for (i = 0, result = 0; i < n; i++) {
241 			if (avd->allowed & current_mapping[tclass].perms[i])
242 				result |= 1<<i;
243 			if (allow_unknown && !current_mapping[tclass].perms[i])
244 				result |= 1<<i;
245 		}
246 		avd->allowed = result;
247 
248 		for (i = 0, result = 0; i < n; i++)
249 			if (avd->auditallow & current_mapping[tclass].perms[i])
250 				result |= 1<<i;
251 		avd->auditallow = result;
252 
253 		for (i = 0, result = 0; i < n; i++) {
254 			if (avd->auditdeny & current_mapping[tclass].perms[i])
255 				result |= 1<<i;
256 			if (!allow_unknown && !current_mapping[tclass].perms[i])
257 				result |= 1<<i;
258 		}
259 		/*
260 		 * In case the kernel has a bug and requests a permission
261 		 * between num_perms and the maximum permission number, we
262 		 * should audit that denial
263 		 */
264 		for (; i < (sizeof(u32)*8); i++)
265 			result |= 1<<i;
266 		avd->auditdeny = result;
267 	}
268 }
269 
security_mls_enabled(void)270 int security_mls_enabled(void)
271 {
272 	return policydb.mls_enabled;
273 }
274 
275 /*
276  * Return the boolean value of a constraint expression
277  * when it is applied to the specified source and target
278  * security contexts.
279  *
280  * xcontext is a special beast...  It is used by the validatetrans rules
281  * only.  For these rules, scontext is the context before the transition,
282  * tcontext is the context after the transition, and xcontext is the context
283  * of the process performing the transition.  All other callers of
284  * constraint_expr_eval should pass in NULL for xcontext.
285  */
constraint_expr_eval(struct context * scontext,struct context * tcontext,struct context * xcontext,struct constraint_expr * cexpr)286 static int constraint_expr_eval(struct context *scontext,
287 				struct context *tcontext,
288 				struct context *xcontext,
289 				struct constraint_expr *cexpr)
290 {
291 	u32 val1, val2;
292 	struct context *c;
293 	struct role_datum *r1, *r2;
294 	struct mls_level *l1, *l2;
295 	struct constraint_expr *e;
296 	int s[CEXPR_MAXDEPTH];
297 	int sp = -1;
298 
299 	for (e = cexpr; e; e = e->next) {
300 		switch (e->expr_type) {
301 		case CEXPR_NOT:
302 			BUG_ON(sp < 0);
303 			s[sp] = !s[sp];
304 			break;
305 		case CEXPR_AND:
306 			BUG_ON(sp < 1);
307 			sp--;
308 			s[sp] &= s[sp + 1];
309 			break;
310 		case CEXPR_OR:
311 			BUG_ON(sp < 1);
312 			sp--;
313 			s[sp] |= s[sp + 1];
314 			break;
315 		case CEXPR_ATTR:
316 			if (sp == (CEXPR_MAXDEPTH - 1))
317 				return 0;
318 			switch (e->attr) {
319 			case CEXPR_USER:
320 				val1 = scontext->user;
321 				val2 = tcontext->user;
322 				break;
323 			case CEXPR_TYPE:
324 				val1 = scontext->type;
325 				val2 = tcontext->type;
326 				break;
327 			case CEXPR_ROLE:
328 				val1 = scontext->role;
329 				val2 = tcontext->role;
330 				r1 = policydb.role_val_to_struct[val1 - 1];
331 				r2 = policydb.role_val_to_struct[val2 - 1];
332 				switch (e->op) {
333 				case CEXPR_DOM:
334 					s[++sp] = ebitmap_get_bit(&r1->dominates,
335 								  val2 - 1);
336 					continue;
337 				case CEXPR_DOMBY:
338 					s[++sp] = ebitmap_get_bit(&r2->dominates,
339 								  val1 - 1);
340 					continue;
341 				case CEXPR_INCOMP:
342 					s[++sp] = (!ebitmap_get_bit(&r1->dominates,
343 								    val2 - 1) &&
344 						   !ebitmap_get_bit(&r2->dominates,
345 								    val1 - 1));
346 					continue;
347 				default:
348 					break;
349 				}
350 				break;
351 			case CEXPR_L1L2:
352 				l1 = &(scontext->range.level[0]);
353 				l2 = &(tcontext->range.level[0]);
354 				goto mls_ops;
355 			case CEXPR_L1H2:
356 				l1 = &(scontext->range.level[0]);
357 				l2 = &(tcontext->range.level[1]);
358 				goto mls_ops;
359 			case CEXPR_H1L2:
360 				l1 = &(scontext->range.level[1]);
361 				l2 = &(tcontext->range.level[0]);
362 				goto mls_ops;
363 			case CEXPR_H1H2:
364 				l1 = &(scontext->range.level[1]);
365 				l2 = &(tcontext->range.level[1]);
366 				goto mls_ops;
367 			case CEXPR_L1H1:
368 				l1 = &(scontext->range.level[0]);
369 				l2 = &(scontext->range.level[1]);
370 				goto mls_ops;
371 			case CEXPR_L2H2:
372 				l1 = &(tcontext->range.level[0]);
373 				l2 = &(tcontext->range.level[1]);
374 				goto mls_ops;
375 mls_ops:
376 			switch (e->op) {
377 			case CEXPR_EQ:
378 				s[++sp] = mls_level_eq(l1, l2);
379 				continue;
380 			case CEXPR_NEQ:
381 				s[++sp] = !mls_level_eq(l1, l2);
382 				continue;
383 			case CEXPR_DOM:
384 				s[++sp] = mls_level_dom(l1, l2);
385 				continue;
386 			case CEXPR_DOMBY:
387 				s[++sp] = mls_level_dom(l2, l1);
388 				continue;
389 			case CEXPR_INCOMP:
390 				s[++sp] = mls_level_incomp(l2, l1);
391 				continue;
392 			default:
393 				BUG();
394 				return 0;
395 			}
396 			break;
397 			default:
398 				BUG();
399 				return 0;
400 			}
401 
402 			switch (e->op) {
403 			case CEXPR_EQ:
404 				s[++sp] = (val1 == val2);
405 				break;
406 			case CEXPR_NEQ:
407 				s[++sp] = (val1 != val2);
408 				break;
409 			default:
410 				BUG();
411 				return 0;
412 			}
413 			break;
414 		case CEXPR_NAMES:
415 			if (sp == (CEXPR_MAXDEPTH-1))
416 				return 0;
417 			c = scontext;
418 			if (e->attr & CEXPR_TARGET)
419 				c = tcontext;
420 			else if (e->attr & CEXPR_XTARGET) {
421 				c = xcontext;
422 				if (!c) {
423 					BUG();
424 					return 0;
425 				}
426 			}
427 			if (e->attr & CEXPR_USER)
428 				val1 = c->user;
429 			else if (e->attr & CEXPR_ROLE)
430 				val1 = c->role;
431 			else if (e->attr & CEXPR_TYPE)
432 				val1 = c->type;
433 			else {
434 				BUG();
435 				return 0;
436 			}
437 
438 			switch (e->op) {
439 			case CEXPR_EQ:
440 				s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
441 				break;
442 			case CEXPR_NEQ:
443 				s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
444 				break;
445 			default:
446 				BUG();
447 				return 0;
448 			}
449 			break;
450 		default:
451 			BUG();
452 			return 0;
453 		}
454 	}
455 
456 	BUG_ON(sp != 0);
457 	return s[0];
458 }
459 
460 /*
461  * security_dump_masked_av - dumps masked permissions during
462  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
463  */
dump_masked_av_helper(void * k,void * d,void * args)464 static int dump_masked_av_helper(void *k, void *d, void *args)
465 {
466 	struct perm_datum *pdatum = d;
467 	char **permission_names = args;
468 
469 	BUG_ON(pdatum->value < 1 || pdatum->value > 32);
470 
471 	permission_names[pdatum->value - 1] = (char *)k;
472 
473 	return 0;
474 }
475 
security_dump_masked_av(struct context * scontext,struct context * tcontext,u16 tclass,u32 permissions,const char * reason)476 static void security_dump_masked_av(struct context *scontext,
477 				    struct context *tcontext,
478 				    u16 tclass,
479 				    u32 permissions,
480 				    const char *reason)
481 {
482 	struct common_datum *common_dat;
483 	struct class_datum *tclass_dat;
484 	struct audit_buffer *ab;
485 	char *tclass_name;
486 	char *scontext_name = NULL;
487 	char *tcontext_name = NULL;
488 	char *permission_names[32];
489 	int index;
490 	u32 length;
491 	bool need_comma = false;
492 
493 	if (!permissions)
494 		return;
495 
496 	tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
497 	tclass_dat = policydb.class_val_to_struct[tclass - 1];
498 	common_dat = tclass_dat->comdatum;
499 
500 	/* init permission_names */
501 	if (common_dat &&
502 	    hashtab_map(common_dat->permissions.table,
503 			dump_masked_av_helper, permission_names) < 0)
504 		goto out;
505 
506 	if (hashtab_map(tclass_dat->permissions.table,
507 			dump_masked_av_helper, permission_names) < 0)
508 		goto out;
509 
510 	/* get scontext/tcontext in text form */
511 	if (context_struct_to_string(scontext,
512 				     &scontext_name, &length) < 0)
513 		goto out;
514 
515 	if (context_struct_to_string(tcontext,
516 				     &tcontext_name, &length) < 0)
517 		goto out;
518 
519 	/* audit a message */
520 	ab = audit_log_start(current->audit_context,
521 			     GFP_ATOMIC, AUDIT_SELINUX_ERR);
522 	if (!ab)
523 		goto out;
524 
525 	audit_log_format(ab, "op=security_compute_av reason=%s "
526 			 "scontext=%s tcontext=%s tclass=%s perms=",
527 			 reason, scontext_name, tcontext_name, tclass_name);
528 
529 	for (index = 0; index < 32; index++) {
530 		u32 mask = (1 << index);
531 
532 		if ((mask & permissions) == 0)
533 			continue;
534 
535 		audit_log_format(ab, "%s%s",
536 				 need_comma ? "," : "",
537 				 permission_names[index]
538 				 ? permission_names[index] : "????");
539 		need_comma = true;
540 	}
541 	audit_log_end(ab);
542 out:
543 	/* release scontext/tcontext */
544 	kfree(tcontext_name);
545 	kfree(scontext_name);
546 
547 	return;
548 }
549 
550 /*
551  * security_boundary_permission - drops violated permissions
552  * on boundary constraint.
553  */
type_attribute_bounds_av(struct context * scontext,struct context * tcontext,u16 tclass,struct av_decision * avd)554 static void type_attribute_bounds_av(struct context *scontext,
555 				     struct context *tcontext,
556 				     u16 tclass,
557 				     struct av_decision *avd)
558 {
559 	struct context lo_scontext;
560 	struct context lo_tcontext, *tcontextp = tcontext;
561 	struct av_decision lo_avd;
562 	struct type_datum *source;
563 	struct type_datum *target;
564 	u32 masked = 0;
565 
566 	source = flex_array_get_ptr(policydb.type_val_to_struct_array,
567 				    scontext->type - 1);
568 	BUG_ON(!source);
569 
570 	if (!source->bounds)
571 		return;
572 
573 	target = flex_array_get_ptr(policydb.type_val_to_struct_array,
574 				    tcontext->type - 1);
575 	BUG_ON(!target);
576 
577 	memset(&lo_avd, 0, sizeof(lo_avd));
578 
579 	memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
580 	lo_scontext.type = source->bounds;
581 
582 	if (target->bounds) {
583 		memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
584 		lo_tcontext.type = target->bounds;
585 		tcontextp = &lo_tcontext;
586 	}
587 
588 	context_struct_compute_av(&lo_scontext,
589 				  tcontextp,
590 				  tclass,
591 				  &lo_avd,
592 				  NULL);
593 
594 	masked = ~lo_avd.allowed & avd->allowed;
595 
596 	if (likely(!masked))
597 		return;		/* no masked permission */
598 
599 	/* mask violated permissions */
600 	avd->allowed &= ~masked;
601 
602 	/* audit masked permissions */
603 	security_dump_masked_av(scontext, tcontext,
604 				tclass, masked, "bounds");
605 }
606 
607 /*
608  * flag which drivers have permissions
609  * only looking for ioctl based extended permssions
610  */
services_compute_xperms_drivers(struct extended_perms * xperms,struct avtab_node * node)611 void services_compute_xperms_drivers(
612 		struct extended_perms *xperms,
613 		struct avtab_node *node)
614 {
615 	unsigned int i;
616 
617 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
618 		/* if one or more driver has all permissions allowed */
619 		for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
620 			xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
621 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
622 		/* if allowing permissions within a driver */
623 		security_xperm_set(xperms->drivers.p,
624 					node->datum.u.xperms->driver);
625 	}
626 
627 	/* If no ioctl commands are allowed, ignore auditallow and auditdeny */
628 	if (node->key.specified & AVTAB_XPERMS_ALLOWED)
629 		xperms->len = 1;
630 }
631 
632 /*
633  * Compute access vectors and extended permissions based on a context
634  * structure pair for the permissions in a particular class.
635  */
context_struct_compute_av(struct context * scontext,struct context * tcontext,u16 tclass,struct av_decision * avd,struct extended_perms * xperms)636 static void context_struct_compute_av(struct context *scontext,
637 					struct context *tcontext,
638 					u16 tclass,
639 					struct av_decision *avd,
640 					struct extended_perms *xperms)
641 {
642 	struct constraint_node *constraint;
643 	struct role_allow *ra;
644 	struct avtab_key avkey;
645 	struct avtab_node *node;
646 	struct class_datum *tclass_datum;
647 	struct ebitmap *sattr, *tattr;
648 	struct ebitmap_node *snode, *tnode;
649 	unsigned int i, j;
650 
651 	avd->allowed = 0;
652 	avd->auditallow = 0;
653 	avd->auditdeny = 0xffffffff;
654 	if (xperms) {
655 		memset(&xperms->drivers, 0, sizeof(xperms->drivers));
656 		xperms->len = 0;
657 	}
658 
659 	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
660 		if (printk_ratelimit())
661 			printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
662 		return;
663 	}
664 
665 	tclass_datum = policydb.class_val_to_struct[tclass - 1];
666 
667 	/*
668 	 * If a specific type enforcement rule was defined for
669 	 * this permission check, then use it.
670 	 */
671 	avkey.target_class = tclass;
672 	avkey.specified = AVTAB_AV | AVTAB_XPERMS;
673 	sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
674 	BUG_ON(!sattr);
675 	tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
676 	BUG_ON(!tattr);
677 	ebitmap_for_each_positive_bit(sattr, snode, i) {
678 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
679 			avkey.source_type = i + 1;
680 			avkey.target_type = j + 1;
681 			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
682 			     node;
683 			     node = avtab_search_node_next(node, avkey.specified)) {
684 				if (node->key.specified == AVTAB_ALLOWED)
685 					avd->allowed |= node->datum.u.data;
686 				else if (node->key.specified == AVTAB_AUDITALLOW)
687 					avd->auditallow |= node->datum.u.data;
688 				else if (node->key.specified == AVTAB_AUDITDENY)
689 					avd->auditdeny &= node->datum.u.data;
690 				else if (xperms && (node->key.specified & AVTAB_XPERMS))
691 					services_compute_xperms_drivers(xperms, node);
692 			}
693 
694 			/* Check conditional av table for additional permissions */
695 			cond_compute_av(&policydb.te_cond_avtab, &avkey,
696 					avd, xperms);
697 
698 		}
699 	}
700 
701 	/*
702 	 * Remove any permissions prohibited by a constraint (this includes
703 	 * the MLS policy).
704 	 */
705 	constraint = tclass_datum->constraints;
706 	while (constraint) {
707 		if ((constraint->permissions & (avd->allowed)) &&
708 		    !constraint_expr_eval(scontext, tcontext, NULL,
709 					  constraint->expr)) {
710 			avd->allowed &= ~(constraint->permissions);
711 		}
712 		constraint = constraint->next;
713 	}
714 
715 	/*
716 	 * If checking process transition permission and the
717 	 * role is changing, then check the (current_role, new_role)
718 	 * pair.
719 	 */
720 	if (tclass == policydb.process_class &&
721 	    (avd->allowed & policydb.process_trans_perms) &&
722 	    scontext->role != tcontext->role) {
723 		for (ra = policydb.role_allow; ra; ra = ra->next) {
724 			if (scontext->role == ra->role &&
725 			    tcontext->role == ra->new_role)
726 				break;
727 		}
728 		if (!ra)
729 			avd->allowed &= ~policydb.process_trans_perms;
730 	}
731 
732 	/*
733 	 * If the given source and target types have boundary
734 	 * constraint, lazy checks have to mask any violated
735 	 * permission and notice it to userspace via audit.
736 	 */
737 	type_attribute_bounds_av(scontext, tcontext,
738 				 tclass, avd);
739 }
740 
security_validtrans_handle_fail(struct context * ocontext,struct context * ncontext,struct context * tcontext,u16 tclass)741 static int security_validtrans_handle_fail(struct context *ocontext,
742 					   struct context *ncontext,
743 					   struct context *tcontext,
744 					   u16 tclass)
745 {
746 	char *o = NULL, *n = NULL, *t = NULL;
747 	u32 olen, nlen, tlen;
748 
749 	if (context_struct_to_string(ocontext, &o, &olen))
750 		goto out;
751 	if (context_struct_to_string(ncontext, &n, &nlen))
752 		goto out;
753 	if (context_struct_to_string(tcontext, &t, &tlen))
754 		goto out;
755 	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
756 		  "op=security_validate_transition seresult=denied"
757 		  " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
758 		  o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
759 out:
760 	kfree(o);
761 	kfree(n);
762 	kfree(t);
763 
764 	if (!selinux_enforcing)
765 		return 0;
766 	return -EPERM;
767 }
768 
security_compute_validatetrans(u32 oldsid,u32 newsid,u32 tasksid,u16 orig_tclass,bool user)769 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
770 					  u16 orig_tclass, bool user)
771 {
772 	struct context *ocontext;
773 	struct context *ncontext;
774 	struct context *tcontext;
775 	struct class_datum *tclass_datum;
776 	struct constraint_node *constraint;
777 	u16 tclass;
778 	int rc = 0;
779 
780 	if (!ss_initialized)
781 		return 0;
782 
783 	read_lock(&policy_rwlock);
784 
785 	if (!user)
786 		tclass = unmap_class(orig_tclass);
787 	else
788 		tclass = orig_tclass;
789 
790 	if (!tclass || tclass > policydb.p_classes.nprim) {
791 		rc = -EINVAL;
792 		goto out;
793 	}
794 	tclass_datum = policydb.class_val_to_struct[tclass - 1];
795 
796 	ocontext = sidtab_search(&sidtab, oldsid);
797 	if (!ocontext) {
798 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
799 			__func__, oldsid);
800 		rc = -EINVAL;
801 		goto out;
802 	}
803 
804 	ncontext = sidtab_search(&sidtab, newsid);
805 	if (!ncontext) {
806 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
807 			__func__, newsid);
808 		rc = -EINVAL;
809 		goto out;
810 	}
811 
812 	tcontext = sidtab_search(&sidtab, tasksid);
813 	if (!tcontext) {
814 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
815 			__func__, tasksid);
816 		rc = -EINVAL;
817 		goto out;
818 	}
819 
820 	constraint = tclass_datum->validatetrans;
821 	while (constraint) {
822 		if (!constraint_expr_eval(ocontext, ncontext, tcontext,
823 					  constraint->expr)) {
824 			if (user)
825 				rc = -EPERM;
826 			else
827 				rc = security_validtrans_handle_fail(ocontext,
828 								     ncontext,
829 								     tcontext,
830 								     tclass);
831 			goto out;
832 		}
833 		constraint = constraint->next;
834 	}
835 
836 out:
837 	read_unlock(&policy_rwlock);
838 	return rc;
839 }
840 
security_validate_transition_user(u32 oldsid,u32 newsid,u32 tasksid,u16 tclass)841 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
842 					u16 tclass)
843 {
844 	return security_compute_validatetrans(oldsid, newsid, tasksid,
845 						tclass, true);
846 }
847 
security_validate_transition(u32 oldsid,u32 newsid,u32 tasksid,u16 orig_tclass)848 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
849 				 u16 orig_tclass)
850 {
851 	return security_compute_validatetrans(oldsid, newsid, tasksid,
852 						orig_tclass, false);
853 }
854 
855 /*
856  * security_bounded_transition - check whether the given
857  * transition is directed to bounded, or not.
858  * It returns 0, if @newsid is bounded by @oldsid.
859  * Otherwise, it returns error code.
860  *
861  * @oldsid : current security identifier
862  * @newsid : destinated security identifier
863  */
security_bounded_transition(u32 old_sid,u32 new_sid)864 int security_bounded_transition(u32 old_sid, u32 new_sid)
865 {
866 	struct context *old_context, *new_context;
867 	struct type_datum *type;
868 	int index;
869 	int rc;
870 
871 	if (!ss_initialized)
872 		return 0;
873 
874 	read_lock(&policy_rwlock);
875 
876 	rc = -EINVAL;
877 	old_context = sidtab_search(&sidtab, old_sid);
878 	if (!old_context) {
879 		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
880 		       __func__, old_sid);
881 		goto out;
882 	}
883 
884 	rc = -EINVAL;
885 	new_context = sidtab_search(&sidtab, new_sid);
886 	if (!new_context) {
887 		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
888 		       __func__, new_sid);
889 		goto out;
890 	}
891 
892 	rc = 0;
893 	/* type/domain unchanged */
894 	if (old_context->type == new_context->type)
895 		goto out;
896 
897 	index = new_context->type;
898 	while (true) {
899 		type = flex_array_get_ptr(policydb.type_val_to_struct_array,
900 					  index - 1);
901 		BUG_ON(!type);
902 
903 		/* not bounded anymore */
904 		rc = -EPERM;
905 		if (!type->bounds)
906 			break;
907 
908 		/* @newsid is bounded by @oldsid */
909 		rc = 0;
910 		if (type->bounds == old_context->type)
911 			break;
912 
913 		index = type->bounds;
914 	}
915 
916 	if (rc) {
917 		char *old_name = NULL;
918 		char *new_name = NULL;
919 		u32 length;
920 
921 		if (!context_struct_to_string(old_context,
922 					      &old_name, &length) &&
923 		    !context_struct_to_string(new_context,
924 					      &new_name, &length)) {
925 			audit_log(current->audit_context,
926 				  GFP_ATOMIC, AUDIT_SELINUX_ERR,
927 				  "op=security_bounded_transition "
928 				  "seresult=denied "
929 				  "oldcontext=%s newcontext=%s",
930 				  old_name, new_name);
931 		}
932 		kfree(new_name);
933 		kfree(old_name);
934 	}
935 out:
936 	read_unlock(&policy_rwlock);
937 
938 	return rc;
939 }
940 
avd_init(struct av_decision * avd)941 static void avd_init(struct av_decision *avd)
942 {
943 	avd->allowed = 0;
944 	avd->auditallow = 0;
945 	avd->auditdeny = 0xffffffff;
946 	avd->seqno = latest_granting;
947 	avd->flags = 0;
948 }
949 
services_compute_xperms_decision(struct extended_perms_decision * xpermd,struct avtab_node * node)950 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
951 					struct avtab_node *node)
952 {
953 	unsigned int i;
954 
955 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
956 		if (xpermd->driver != node->datum.u.xperms->driver)
957 			return;
958 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
959 		if (!security_xperm_test(node->datum.u.xperms->perms.p,
960 					xpermd->driver))
961 			return;
962 	} else {
963 		BUG();
964 	}
965 
966 	if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
967 		xpermd->used |= XPERMS_ALLOWED;
968 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
969 			memset(xpermd->allowed->p, 0xff,
970 					sizeof(xpermd->allowed->p));
971 		}
972 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
973 			for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
974 				xpermd->allowed->p[i] |=
975 					node->datum.u.xperms->perms.p[i];
976 		}
977 	} else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
978 		xpermd->used |= XPERMS_AUDITALLOW;
979 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
980 			memset(xpermd->auditallow->p, 0xff,
981 					sizeof(xpermd->auditallow->p));
982 		}
983 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
984 			for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
985 				xpermd->auditallow->p[i] |=
986 					node->datum.u.xperms->perms.p[i];
987 		}
988 	} else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
989 		xpermd->used |= XPERMS_DONTAUDIT;
990 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
991 			memset(xpermd->dontaudit->p, 0xff,
992 					sizeof(xpermd->dontaudit->p));
993 		}
994 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
995 			for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
996 				xpermd->dontaudit->p[i] |=
997 					node->datum.u.xperms->perms.p[i];
998 		}
999 	} else {
1000 		BUG();
1001 	}
1002 }
1003 
security_compute_xperms_decision(u32 ssid,u32 tsid,u16 orig_tclass,u8 driver,struct extended_perms_decision * xpermd)1004 void security_compute_xperms_decision(u32 ssid,
1005 				u32 tsid,
1006 				u16 orig_tclass,
1007 				u8 driver,
1008 				struct extended_perms_decision *xpermd)
1009 {
1010 	u16 tclass;
1011 	struct context *scontext, *tcontext;
1012 	struct avtab_key avkey;
1013 	struct avtab_node *node;
1014 	struct ebitmap *sattr, *tattr;
1015 	struct ebitmap_node *snode, *tnode;
1016 	unsigned int i, j;
1017 
1018 	xpermd->driver = driver;
1019 	xpermd->used = 0;
1020 	memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1021 	memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1022 	memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1023 
1024 	read_lock(&policy_rwlock);
1025 	if (!ss_initialized)
1026 		goto allow;
1027 
1028 	scontext = sidtab_search(&sidtab, ssid);
1029 	if (!scontext) {
1030 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1031 		       __func__, ssid);
1032 		goto out;
1033 	}
1034 
1035 	tcontext = sidtab_search(&sidtab, tsid);
1036 	if (!tcontext) {
1037 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1038 		       __func__, tsid);
1039 		goto out;
1040 	}
1041 
1042 	tclass = unmap_class(orig_tclass);
1043 	if (unlikely(orig_tclass && !tclass)) {
1044 		if (policydb.allow_unknown)
1045 			goto allow;
1046 		goto out;
1047 	}
1048 
1049 
1050 	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1051 		pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1052 		goto out;
1053 	}
1054 
1055 	avkey.target_class = tclass;
1056 	avkey.specified = AVTAB_XPERMS;
1057 	sattr = flex_array_get(policydb.type_attr_map_array,
1058 				scontext->type - 1);
1059 	BUG_ON(!sattr);
1060 	tattr = flex_array_get(policydb.type_attr_map_array,
1061 				tcontext->type - 1);
1062 	BUG_ON(!tattr);
1063 	ebitmap_for_each_positive_bit(sattr, snode, i) {
1064 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
1065 			avkey.source_type = i + 1;
1066 			avkey.target_type = j + 1;
1067 			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1068 			     node;
1069 			     node = avtab_search_node_next(node, avkey.specified))
1070 				services_compute_xperms_decision(xpermd, node);
1071 
1072 			cond_compute_xperms(&policydb.te_cond_avtab,
1073 						&avkey, xpermd);
1074 		}
1075 	}
1076 out:
1077 	read_unlock(&policy_rwlock);
1078 	return;
1079 allow:
1080 	memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1081 	goto out;
1082 }
1083 
1084 /**
1085  * security_compute_av - Compute access vector decisions.
1086  * @ssid: source security identifier
1087  * @tsid: target security identifier
1088  * @tclass: target security class
1089  * @avd: access vector decisions
1090  * @xperms: extended permissions
1091  *
1092  * Compute a set of access vector decisions based on the
1093  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1094  */
security_compute_av(u32 ssid,u32 tsid,u16 orig_tclass,struct av_decision * avd,struct extended_perms * xperms)1095 void security_compute_av(u32 ssid,
1096 			 u32 tsid,
1097 			 u16 orig_tclass,
1098 			 struct av_decision *avd,
1099 			 struct extended_perms *xperms)
1100 {
1101 	u16 tclass;
1102 	struct context *scontext = NULL, *tcontext = NULL;
1103 
1104 	read_lock(&policy_rwlock);
1105 	avd_init(avd);
1106 	xperms->len = 0;
1107 	if (!ss_initialized)
1108 		goto allow;
1109 
1110 	scontext = sidtab_search(&sidtab, ssid);
1111 	if (!scontext) {
1112 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1113 		       __func__, ssid);
1114 		goto out;
1115 	}
1116 
1117 	/* permissive domain? */
1118 	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1119 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1120 
1121 	tcontext = sidtab_search(&sidtab, tsid);
1122 	if (!tcontext) {
1123 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1124 		       __func__, tsid);
1125 		goto out;
1126 	}
1127 
1128 	tclass = unmap_class(orig_tclass);
1129 	if (unlikely(orig_tclass && !tclass)) {
1130 		if (policydb.allow_unknown)
1131 			goto allow;
1132 		goto out;
1133 	}
1134 	context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1135 	map_decision(orig_tclass, avd, policydb.allow_unknown);
1136 out:
1137 	read_unlock(&policy_rwlock);
1138 	return;
1139 allow:
1140 	avd->allowed = 0xffffffff;
1141 	goto out;
1142 }
1143 
security_compute_av_user(u32 ssid,u32 tsid,u16 tclass,struct av_decision * avd)1144 void security_compute_av_user(u32 ssid,
1145 			      u32 tsid,
1146 			      u16 tclass,
1147 			      struct av_decision *avd)
1148 {
1149 	struct context *scontext = NULL, *tcontext = NULL;
1150 
1151 	read_lock(&policy_rwlock);
1152 	avd_init(avd);
1153 	if (!ss_initialized)
1154 		goto allow;
1155 
1156 	scontext = sidtab_search(&sidtab, ssid);
1157 	if (!scontext) {
1158 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1159 		       __func__, ssid);
1160 		goto out;
1161 	}
1162 
1163 	/* permissive domain? */
1164 	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1165 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1166 
1167 	tcontext = sidtab_search(&sidtab, tsid);
1168 	if (!tcontext) {
1169 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1170 		       __func__, tsid);
1171 		goto out;
1172 	}
1173 
1174 	if (unlikely(!tclass)) {
1175 		if (policydb.allow_unknown)
1176 			goto allow;
1177 		goto out;
1178 	}
1179 
1180 	context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1181  out:
1182 	read_unlock(&policy_rwlock);
1183 	return;
1184 allow:
1185 	avd->allowed = 0xffffffff;
1186 	goto out;
1187 }
1188 
1189 /*
1190  * Write the security context string representation of
1191  * the context structure `context' into a dynamically
1192  * allocated string of the correct size.  Set `*scontext'
1193  * to point to this string and set `*scontext_len' to
1194  * the length of the string.
1195  */
context_struct_to_string(struct context * context,char ** scontext,u32 * scontext_len)1196 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1197 {
1198 	char *scontextp;
1199 
1200 	if (scontext)
1201 		*scontext = NULL;
1202 	*scontext_len = 0;
1203 
1204 	if (context->len) {
1205 		*scontext_len = context->len;
1206 		if (scontext) {
1207 			*scontext = kstrdup(context->str, GFP_ATOMIC);
1208 			if (!(*scontext))
1209 				return -ENOMEM;
1210 		}
1211 		return 0;
1212 	}
1213 
1214 	/* Compute the size of the context. */
1215 	*scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1216 	*scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1217 	*scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1218 	*scontext_len += mls_compute_context_len(context);
1219 
1220 	if (!scontext)
1221 		return 0;
1222 
1223 	/* Allocate space for the context; caller must free this space. */
1224 	scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1225 	if (!scontextp)
1226 		return -ENOMEM;
1227 	*scontext = scontextp;
1228 
1229 	/*
1230 	 * Copy the user name, role name and type name into the context.
1231 	 */
1232 	scontextp += sprintf(scontextp, "%s:%s:%s",
1233 		sym_name(&policydb, SYM_USERS, context->user - 1),
1234 		sym_name(&policydb, SYM_ROLES, context->role - 1),
1235 		sym_name(&policydb, SYM_TYPES, context->type - 1));
1236 
1237 	mls_sid_to_context(context, &scontextp);
1238 
1239 	*scontextp = 0;
1240 
1241 	return 0;
1242 }
1243 
1244 #include "initial_sid_to_string.h"
1245 
security_get_initial_sid_context(u32 sid)1246 const char *security_get_initial_sid_context(u32 sid)
1247 {
1248 	if (unlikely(sid > SECINITSID_NUM))
1249 		return NULL;
1250 	return initial_sid_to_string[sid];
1251 }
1252 
security_sid_to_context_core(u32 sid,char ** scontext,u32 * scontext_len,int force)1253 static int security_sid_to_context_core(u32 sid, char **scontext,
1254 					u32 *scontext_len, int force)
1255 {
1256 	struct context *context;
1257 	int rc = 0;
1258 
1259 	if (scontext)
1260 		*scontext = NULL;
1261 	*scontext_len  = 0;
1262 
1263 	if (!ss_initialized) {
1264 		if (sid <= SECINITSID_NUM) {
1265 			char *scontextp;
1266 
1267 			*scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1268 			if (!scontext)
1269 				goto out;
1270 			scontextp = kmemdup(initial_sid_to_string[sid],
1271 					    *scontext_len, GFP_ATOMIC);
1272 			if (!scontextp) {
1273 				rc = -ENOMEM;
1274 				goto out;
1275 			}
1276 			*scontext = scontextp;
1277 			goto out;
1278 		}
1279 		printk(KERN_ERR "SELinux: %s:  called before initial "
1280 		       "load_policy on unknown SID %d\n", __func__, sid);
1281 		rc = -EINVAL;
1282 		goto out;
1283 	}
1284 	read_lock(&policy_rwlock);
1285 	if (force)
1286 		context = sidtab_search_force(&sidtab, sid);
1287 	else
1288 		context = sidtab_search(&sidtab, sid);
1289 	if (!context) {
1290 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1291 			__func__, sid);
1292 		rc = -EINVAL;
1293 		goto out_unlock;
1294 	}
1295 	rc = context_struct_to_string(context, scontext, scontext_len);
1296 out_unlock:
1297 	read_unlock(&policy_rwlock);
1298 out:
1299 	return rc;
1300 
1301 }
1302 
1303 /**
1304  * security_sid_to_context - Obtain a context for a given SID.
1305  * @sid: security identifier, SID
1306  * @scontext: security context
1307  * @scontext_len: length in bytes
1308  *
1309  * Write the string representation of the context associated with @sid
1310  * into a dynamically allocated string of the correct size.  Set @scontext
1311  * to point to this string and set @scontext_len to the length of the string.
1312  */
security_sid_to_context(u32 sid,char ** scontext,u32 * scontext_len)1313 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1314 {
1315 	return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1316 }
1317 
security_sid_to_context_force(u32 sid,char ** scontext,u32 * scontext_len)1318 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1319 {
1320 	return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1321 }
1322 
1323 /*
1324  * Caveat:  Mutates scontext.
1325  */
string_to_context_struct(struct policydb * pol,struct sidtab * sidtabp,char * scontext,u32 scontext_len,struct context * ctx,u32 def_sid)1326 static int string_to_context_struct(struct policydb *pol,
1327 				    struct sidtab *sidtabp,
1328 				    char *scontext,
1329 				    u32 scontext_len,
1330 				    struct context *ctx,
1331 				    u32 def_sid)
1332 {
1333 	struct role_datum *role;
1334 	struct type_datum *typdatum;
1335 	struct user_datum *usrdatum;
1336 	char *scontextp, *p, oldc;
1337 	int rc = 0;
1338 
1339 	context_init(ctx);
1340 
1341 	/* Parse the security context. */
1342 
1343 	rc = -EINVAL;
1344 	scontextp = (char *) scontext;
1345 
1346 	/* Extract the user. */
1347 	p = scontextp;
1348 	while (*p && *p != ':')
1349 		p++;
1350 
1351 	if (*p == 0)
1352 		goto out;
1353 
1354 	*p++ = 0;
1355 
1356 	usrdatum = hashtab_search(pol->p_users.table, scontextp);
1357 	if (!usrdatum)
1358 		goto out;
1359 
1360 	ctx->user = usrdatum->value;
1361 
1362 	/* Extract role. */
1363 	scontextp = p;
1364 	while (*p && *p != ':')
1365 		p++;
1366 
1367 	if (*p == 0)
1368 		goto out;
1369 
1370 	*p++ = 0;
1371 
1372 	role = hashtab_search(pol->p_roles.table, scontextp);
1373 	if (!role)
1374 		goto out;
1375 	ctx->role = role->value;
1376 
1377 	/* Extract type. */
1378 	scontextp = p;
1379 	while (*p && *p != ':')
1380 		p++;
1381 	oldc = *p;
1382 	*p++ = 0;
1383 
1384 	typdatum = hashtab_search(pol->p_types.table, scontextp);
1385 	if (!typdatum || typdatum->attribute)
1386 		goto out;
1387 
1388 	ctx->type = typdatum->value;
1389 
1390 	rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1391 	if (rc)
1392 		goto out;
1393 
1394 	rc = -EINVAL;
1395 	if ((p - scontext) < scontext_len)
1396 		goto out;
1397 
1398 	/* Check the validity of the new context. */
1399 	if (!policydb_context_isvalid(pol, ctx))
1400 		goto out;
1401 	rc = 0;
1402 out:
1403 	if (rc)
1404 		context_destroy(ctx);
1405 	return rc;
1406 }
1407 
security_context_to_sid_core(const char * scontext,u32 scontext_len,u32 * sid,u32 def_sid,gfp_t gfp_flags,int force)1408 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1409 					u32 *sid, u32 def_sid, gfp_t gfp_flags,
1410 					int force)
1411 {
1412 	char *scontext2, *str = NULL;
1413 	struct context context;
1414 	int rc = 0;
1415 
1416 	/* An empty security context is never valid. */
1417 	if (!scontext_len)
1418 		return -EINVAL;
1419 
1420 	/* Copy the string to allow changes and ensure a NUL terminator */
1421 	scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1422 	if (!scontext2)
1423 		return -ENOMEM;
1424 
1425 	if (!ss_initialized) {
1426 		int i;
1427 
1428 		for (i = 1; i < SECINITSID_NUM; i++) {
1429 			if (!strcmp(initial_sid_to_string[i], scontext2)) {
1430 				*sid = i;
1431 				goto out;
1432 			}
1433 		}
1434 		*sid = SECINITSID_KERNEL;
1435 		goto out;
1436 	}
1437 	*sid = SECSID_NULL;
1438 
1439 	if (force) {
1440 		/* Save another copy for storing in uninterpreted form */
1441 		rc = -ENOMEM;
1442 		str = kstrdup(scontext2, gfp_flags);
1443 		if (!str)
1444 			goto out;
1445 	}
1446 
1447 	read_lock(&policy_rwlock);
1448 	rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1449 				      scontext_len, &context, def_sid);
1450 	if (rc == -EINVAL && force) {
1451 		context.str = str;
1452 		context.len = strlen(str) + 1;
1453 		str = NULL;
1454 	} else if (rc)
1455 		goto out_unlock;
1456 	rc = sidtab_context_to_sid(&sidtab, &context, sid);
1457 	context_destroy(&context);
1458 out_unlock:
1459 	read_unlock(&policy_rwlock);
1460 out:
1461 	kfree(scontext2);
1462 	kfree(str);
1463 	return rc;
1464 }
1465 
1466 /**
1467  * security_context_to_sid - Obtain a SID for a given security context.
1468  * @scontext: security context
1469  * @scontext_len: length in bytes
1470  * @sid: security identifier, SID
1471  * @gfp: context for the allocation
1472  *
1473  * Obtains a SID associated with the security context that
1474  * has the string representation specified by @scontext.
1475  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1476  * memory is available, or 0 on success.
1477  */
security_context_to_sid(const char * scontext,u32 scontext_len,u32 * sid,gfp_t gfp)1478 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1479 			    gfp_t gfp)
1480 {
1481 	return security_context_to_sid_core(scontext, scontext_len,
1482 					    sid, SECSID_NULL, gfp, 0);
1483 }
1484 
security_context_str_to_sid(const char * scontext,u32 * sid,gfp_t gfp)1485 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1486 {
1487 	return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1488 }
1489 
1490 /**
1491  * security_context_to_sid_default - Obtain a SID for a given security context,
1492  * falling back to specified default if needed.
1493  *
1494  * @scontext: security context
1495  * @scontext_len: length in bytes
1496  * @sid: security identifier, SID
1497  * @def_sid: default SID to assign on error
1498  *
1499  * Obtains a SID associated with the security context that
1500  * has the string representation specified by @scontext.
1501  * The default SID is passed to the MLS layer to be used to allow
1502  * kernel labeling of the MLS field if the MLS field is not present
1503  * (for upgrading to MLS without full relabel).
1504  * Implicitly forces adding of the context even if it cannot be mapped yet.
1505  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1506  * memory is available, or 0 on success.
1507  */
security_context_to_sid_default(const char * scontext,u32 scontext_len,u32 * sid,u32 def_sid,gfp_t gfp_flags)1508 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1509 				    u32 *sid, u32 def_sid, gfp_t gfp_flags)
1510 {
1511 	return security_context_to_sid_core(scontext, scontext_len,
1512 					    sid, def_sid, gfp_flags, 1);
1513 }
1514 
security_context_to_sid_force(const char * scontext,u32 scontext_len,u32 * sid)1515 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1516 				  u32 *sid)
1517 {
1518 	return security_context_to_sid_core(scontext, scontext_len,
1519 					    sid, SECSID_NULL, GFP_KERNEL, 1);
1520 }
1521 
compute_sid_handle_invalid_context(struct context * scontext,struct context * tcontext,u16 tclass,struct context * newcontext)1522 static int compute_sid_handle_invalid_context(
1523 	struct context *scontext,
1524 	struct context *tcontext,
1525 	u16 tclass,
1526 	struct context *newcontext)
1527 {
1528 	char *s = NULL, *t = NULL, *n = NULL;
1529 	u32 slen, tlen, nlen;
1530 
1531 	if (context_struct_to_string(scontext, &s, &slen))
1532 		goto out;
1533 	if (context_struct_to_string(tcontext, &t, &tlen))
1534 		goto out;
1535 	if (context_struct_to_string(newcontext, &n, &nlen))
1536 		goto out;
1537 	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1538 		  "op=security_compute_sid invalid_context=%s"
1539 		  " scontext=%s"
1540 		  " tcontext=%s"
1541 		  " tclass=%s",
1542 		  n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1543 out:
1544 	kfree(s);
1545 	kfree(t);
1546 	kfree(n);
1547 	if (!selinux_enforcing)
1548 		return 0;
1549 	return -EACCES;
1550 }
1551 
filename_compute_type(struct policydb * p,struct context * newcontext,u32 stype,u32 ttype,u16 tclass,const char * objname)1552 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1553 				  u32 stype, u32 ttype, u16 tclass,
1554 				  const char *objname)
1555 {
1556 	struct filename_trans ft;
1557 	struct filename_trans_datum *otype;
1558 
1559 	/*
1560 	 * Most filename trans rules are going to live in specific directories
1561 	 * like /dev or /var/run.  This bitmap will quickly skip rule searches
1562 	 * if the ttype does not contain any rules.
1563 	 */
1564 	if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1565 		return;
1566 
1567 	ft.stype = stype;
1568 	ft.ttype = ttype;
1569 	ft.tclass = tclass;
1570 	ft.name = objname;
1571 
1572 	otype = hashtab_search(p->filename_trans, &ft);
1573 	if (otype)
1574 		newcontext->type = otype->otype;
1575 }
1576 
security_compute_sid(u32 ssid,u32 tsid,u16 orig_tclass,u32 specified,const char * objname,u32 * out_sid,bool kern)1577 static int security_compute_sid(u32 ssid,
1578 				u32 tsid,
1579 				u16 orig_tclass,
1580 				u32 specified,
1581 				const char *objname,
1582 				u32 *out_sid,
1583 				bool kern)
1584 {
1585 	struct class_datum *cladatum = NULL;
1586 	struct context *scontext = NULL, *tcontext = NULL, newcontext;
1587 	struct role_trans *roletr = NULL;
1588 	struct avtab_key avkey;
1589 	struct avtab_datum *avdatum;
1590 	struct avtab_node *node;
1591 	u16 tclass;
1592 	int rc = 0;
1593 	bool sock;
1594 
1595 	if (!ss_initialized) {
1596 		switch (orig_tclass) {
1597 		case SECCLASS_PROCESS: /* kernel value */
1598 			*out_sid = ssid;
1599 			break;
1600 		default:
1601 			*out_sid = tsid;
1602 			break;
1603 		}
1604 		goto out;
1605 	}
1606 
1607 	context_init(&newcontext);
1608 
1609 	read_lock(&policy_rwlock);
1610 
1611 	if (kern) {
1612 		tclass = unmap_class(orig_tclass);
1613 		sock = security_is_socket_class(orig_tclass);
1614 	} else {
1615 		tclass = orig_tclass;
1616 		sock = security_is_socket_class(map_class(tclass));
1617 	}
1618 
1619 	scontext = sidtab_search(&sidtab, ssid);
1620 	if (!scontext) {
1621 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1622 		       __func__, ssid);
1623 		rc = -EINVAL;
1624 		goto out_unlock;
1625 	}
1626 	tcontext = sidtab_search(&sidtab, tsid);
1627 	if (!tcontext) {
1628 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1629 		       __func__, tsid);
1630 		rc = -EINVAL;
1631 		goto out_unlock;
1632 	}
1633 
1634 	if (tclass && tclass <= policydb.p_classes.nprim)
1635 		cladatum = policydb.class_val_to_struct[tclass - 1];
1636 
1637 	/* Set the user identity. */
1638 	switch (specified) {
1639 	case AVTAB_TRANSITION:
1640 	case AVTAB_CHANGE:
1641 		if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1642 			newcontext.user = tcontext->user;
1643 		} else {
1644 			/* notice this gets both DEFAULT_SOURCE and unset */
1645 			/* Use the process user identity. */
1646 			newcontext.user = scontext->user;
1647 		}
1648 		break;
1649 	case AVTAB_MEMBER:
1650 		/* Use the related object owner. */
1651 		newcontext.user = tcontext->user;
1652 		break;
1653 	}
1654 
1655 	/* Set the role to default values. */
1656 	if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1657 		newcontext.role = scontext->role;
1658 	} else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1659 		newcontext.role = tcontext->role;
1660 	} else {
1661 		if ((tclass == policydb.process_class) || (sock == true))
1662 			newcontext.role = scontext->role;
1663 		else
1664 			newcontext.role = OBJECT_R_VAL;
1665 	}
1666 
1667 	/* Set the type to default values. */
1668 	if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1669 		newcontext.type = scontext->type;
1670 	} else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1671 		newcontext.type = tcontext->type;
1672 	} else {
1673 		if ((tclass == policydb.process_class) || (sock == true)) {
1674 			/* Use the type of process. */
1675 			newcontext.type = scontext->type;
1676 		} else {
1677 			/* Use the type of the related object. */
1678 			newcontext.type = tcontext->type;
1679 		}
1680 	}
1681 
1682 	/* Look for a type transition/member/change rule. */
1683 	avkey.source_type = scontext->type;
1684 	avkey.target_type = tcontext->type;
1685 	avkey.target_class = tclass;
1686 	avkey.specified = specified;
1687 	avdatum = avtab_search(&policydb.te_avtab, &avkey);
1688 
1689 	/* If no permanent rule, also check for enabled conditional rules */
1690 	if (!avdatum) {
1691 		node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1692 		for (; node; node = avtab_search_node_next(node, specified)) {
1693 			if (node->key.specified & AVTAB_ENABLED) {
1694 				avdatum = &node->datum;
1695 				break;
1696 			}
1697 		}
1698 	}
1699 
1700 	if (avdatum) {
1701 		/* Use the type from the type transition/member/change rule. */
1702 		newcontext.type = avdatum->u.data;
1703 	}
1704 
1705 	/* if we have a objname this is a file trans check so check those rules */
1706 	if (objname)
1707 		filename_compute_type(&policydb, &newcontext, scontext->type,
1708 				      tcontext->type, tclass, objname);
1709 
1710 	/* Check for class-specific changes. */
1711 	if (specified & AVTAB_TRANSITION) {
1712 		/* Look for a role transition rule. */
1713 		for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1714 			if ((roletr->role == scontext->role) &&
1715 			    (roletr->type == tcontext->type) &&
1716 			    (roletr->tclass == tclass)) {
1717 				/* Use the role transition rule. */
1718 				newcontext.role = roletr->new_role;
1719 				break;
1720 			}
1721 		}
1722 	}
1723 
1724 	/* Set the MLS attributes.
1725 	   This is done last because it may allocate memory. */
1726 	rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1727 			     &newcontext, sock);
1728 	if (rc)
1729 		goto out_unlock;
1730 
1731 	/* Check the validity of the context. */
1732 	if (!policydb_context_isvalid(&policydb, &newcontext)) {
1733 		rc = compute_sid_handle_invalid_context(scontext,
1734 							tcontext,
1735 							tclass,
1736 							&newcontext);
1737 		if (rc)
1738 			goto out_unlock;
1739 	}
1740 	/* Obtain the sid for the context. */
1741 	rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1742 out_unlock:
1743 	read_unlock(&policy_rwlock);
1744 	context_destroy(&newcontext);
1745 out:
1746 	return rc;
1747 }
1748 
1749 /**
1750  * security_transition_sid - Compute the SID for a new subject/object.
1751  * @ssid: source security identifier
1752  * @tsid: target security identifier
1753  * @tclass: target security class
1754  * @out_sid: security identifier for new subject/object
1755  *
1756  * Compute a SID to use for labeling a new subject or object in the
1757  * class @tclass based on a SID pair (@ssid, @tsid).
1758  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1759  * if insufficient memory is available, or %0 if the new SID was
1760  * computed successfully.
1761  */
security_transition_sid(u32 ssid,u32 tsid,u16 tclass,const struct qstr * qstr,u32 * out_sid)1762 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1763 			    const struct qstr *qstr, u32 *out_sid)
1764 {
1765 	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1766 				    qstr ? qstr->name : NULL, out_sid, true);
1767 }
1768 
security_transition_sid_user(u32 ssid,u32 tsid,u16 tclass,const char * objname,u32 * out_sid)1769 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1770 				 const char *objname, u32 *out_sid)
1771 {
1772 	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1773 				    objname, out_sid, false);
1774 }
1775 
1776 /**
1777  * security_member_sid - Compute the SID for member selection.
1778  * @ssid: source security identifier
1779  * @tsid: target security identifier
1780  * @tclass: target security class
1781  * @out_sid: security identifier for selected member
1782  *
1783  * Compute a SID to use when selecting a member of a polyinstantiated
1784  * object of class @tclass based on a SID pair (@ssid, @tsid).
1785  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1786  * if insufficient memory is available, or %0 if the SID was
1787  * computed successfully.
1788  */
security_member_sid(u32 ssid,u32 tsid,u16 tclass,u32 * out_sid)1789 int security_member_sid(u32 ssid,
1790 			u32 tsid,
1791 			u16 tclass,
1792 			u32 *out_sid)
1793 {
1794 	return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1795 				    out_sid, false);
1796 }
1797 
1798 /**
1799  * security_change_sid - Compute the SID for object relabeling.
1800  * @ssid: source security identifier
1801  * @tsid: target security identifier
1802  * @tclass: target security class
1803  * @out_sid: security identifier for selected member
1804  *
1805  * Compute a SID to use for relabeling an object of class @tclass
1806  * based on a SID pair (@ssid, @tsid).
1807  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1808  * if insufficient memory is available, or %0 if the SID was
1809  * computed successfully.
1810  */
security_change_sid(u32 ssid,u32 tsid,u16 tclass,u32 * out_sid)1811 int security_change_sid(u32 ssid,
1812 			u32 tsid,
1813 			u16 tclass,
1814 			u32 *out_sid)
1815 {
1816 	return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1817 				    out_sid, false);
1818 }
1819 
1820 /* Clone the SID into the new SID table. */
clone_sid(u32 sid,struct context * context,void * arg)1821 static int clone_sid(u32 sid,
1822 		     struct context *context,
1823 		     void *arg)
1824 {
1825 	struct sidtab *s = arg;
1826 
1827 	if (sid > SECINITSID_NUM)
1828 		return sidtab_insert(s, sid, context);
1829 	else
1830 		return 0;
1831 }
1832 
convert_context_handle_invalid_context(struct context * context)1833 static inline int convert_context_handle_invalid_context(struct context *context)
1834 {
1835 	char *s;
1836 	u32 len;
1837 
1838 	if (selinux_enforcing)
1839 		return -EINVAL;
1840 
1841 	if (!context_struct_to_string(context, &s, &len)) {
1842 		printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1843 		kfree(s);
1844 	}
1845 	return 0;
1846 }
1847 
1848 struct convert_context_args {
1849 	struct policydb *oldp;
1850 	struct policydb *newp;
1851 };
1852 
1853 /*
1854  * Convert the values in the security context
1855  * structure `c' from the values specified
1856  * in the policy `p->oldp' to the values specified
1857  * in the policy `p->newp'.  Verify that the
1858  * context is valid under the new policy.
1859  */
convert_context(u32 key,struct context * c,void * p)1860 static int convert_context(u32 key,
1861 			   struct context *c,
1862 			   void *p)
1863 {
1864 	struct convert_context_args *args;
1865 	struct context oldc;
1866 	struct ocontext *oc;
1867 	struct mls_range *range;
1868 	struct role_datum *role;
1869 	struct type_datum *typdatum;
1870 	struct user_datum *usrdatum;
1871 	char *s;
1872 	u32 len;
1873 	int rc = 0;
1874 
1875 	if (key <= SECINITSID_NUM)
1876 		goto out;
1877 
1878 	args = p;
1879 
1880 	if (c->str) {
1881 		struct context ctx;
1882 
1883 		rc = -ENOMEM;
1884 		s = kstrdup(c->str, GFP_KERNEL);
1885 		if (!s)
1886 			goto out;
1887 
1888 		rc = string_to_context_struct(args->newp, NULL, s,
1889 					      c->len, &ctx, SECSID_NULL);
1890 		kfree(s);
1891 		if (!rc) {
1892 			printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1893 			       c->str);
1894 			/* Replace string with mapped representation. */
1895 			kfree(c->str);
1896 			memcpy(c, &ctx, sizeof(*c));
1897 			goto out;
1898 		} else if (rc == -EINVAL) {
1899 			/* Retain string representation for later mapping. */
1900 			rc = 0;
1901 			goto out;
1902 		} else {
1903 			/* Other error condition, e.g. ENOMEM. */
1904 			printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1905 			       c->str, -rc);
1906 			goto out;
1907 		}
1908 	}
1909 
1910 	rc = context_cpy(&oldc, c);
1911 	if (rc)
1912 		goto out;
1913 
1914 	/* Convert the user. */
1915 	rc = -EINVAL;
1916 	usrdatum = hashtab_search(args->newp->p_users.table,
1917 				  sym_name(args->oldp, SYM_USERS, c->user - 1));
1918 	if (!usrdatum)
1919 		goto bad;
1920 	c->user = usrdatum->value;
1921 
1922 	/* Convert the role. */
1923 	rc = -EINVAL;
1924 	role = hashtab_search(args->newp->p_roles.table,
1925 			      sym_name(args->oldp, SYM_ROLES, c->role - 1));
1926 	if (!role)
1927 		goto bad;
1928 	c->role = role->value;
1929 
1930 	/* Convert the type. */
1931 	rc = -EINVAL;
1932 	typdatum = hashtab_search(args->newp->p_types.table,
1933 				  sym_name(args->oldp, SYM_TYPES, c->type - 1));
1934 	if (!typdatum)
1935 		goto bad;
1936 	c->type = typdatum->value;
1937 
1938 	/* Convert the MLS fields if dealing with MLS policies */
1939 	if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1940 		rc = mls_convert_context(args->oldp, args->newp, c);
1941 		if (rc)
1942 			goto bad;
1943 	} else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1944 		/*
1945 		 * Switching between MLS and non-MLS policy:
1946 		 * free any storage used by the MLS fields in the
1947 		 * context for all existing entries in the sidtab.
1948 		 */
1949 		mls_context_destroy(c);
1950 	} else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1951 		/*
1952 		 * Switching between non-MLS and MLS policy:
1953 		 * ensure that the MLS fields of the context for all
1954 		 * existing entries in the sidtab are filled in with a
1955 		 * suitable default value, likely taken from one of the
1956 		 * initial SIDs.
1957 		 */
1958 		oc = args->newp->ocontexts[OCON_ISID];
1959 		while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1960 			oc = oc->next;
1961 		rc = -EINVAL;
1962 		if (!oc) {
1963 			printk(KERN_ERR "SELinux:  unable to look up"
1964 				" the initial SIDs list\n");
1965 			goto bad;
1966 		}
1967 		range = &oc->context[0].range;
1968 		rc = mls_range_set(c, range);
1969 		if (rc)
1970 			goto bad;
1971 	}
1972 
1973 	/* Check the validity of the new context. */
1974 	if (!policydb_context_isvalid(args->newp, c)) {
1975 		rc = convert_context_handle_invalid_context(&oldc);
1976 		if (rc)
1977 			goto bad;
1978 	}
1979 
1980 	context_destroy(&oldc);
1981 
1982 	rc = 0;
1983 out:
1984 	return rc;
1985 bad:
1986 	/* Map old representation to string and save it. */
1987 	rc = context_struct_to_string(&oldc, &s, &len);
1988 	if (rc)
1989 		return rc;
1990 	context_destroy(&oldc);
1991 	context_destroy(c);
1992 	c->str = s;
1993 	c->len = len;
1994 	printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1995 	       c->str);
1996 	rc = 0;
1997 	goto out;
1998 }
1999 
security_load_policycaps(void)2000 static void security_load_policycaps(void)
2001 {
2002 	unsigned int i;
2003 	struct ebitmap_node *node;
2004 
2005 	selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
2006 						  POLICYDB_CAPABILITY_NETPEER);
2007 	selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
2008 						  POLICYDB_CAPABILITY_OPENPERM);
2009 	selinux_policycap_extsockclass = ebitmap_get_bit(&policydb.policycaps,
2010 					  POLICYDB_CAPABILITY_EXTSOCKCLASS);
2011 	selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
2012 						  POLICYDB_CAPABILITY_ALWAYSNETWORK);
2013 	selinux_policycap_cgroupseclabel =
2014 		ebitmap_get_bit(&policydb.policycaps,
2015 				POLICYDB_CAPABILITY_CGROUPSECLABEL);
2016 	selinux_policycap_nnp_nosuid_transition =
2017 		ebitmap_get_bit(&policydb.policycaps,
2018 				POLICYDB_CAPABILITY_NNP_NOSUID_TRANSITION);
2019 
2020 	for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2021 		pr_info("SELinux:  policy capability %s=%d\n",
2022 			selinux_policycap_names[i],
2023 			ebitmap_get_bit(&policydb.policycaps, i));
2024 
2025 	ebitmap_for_each_positive_bit(&policydb.policycaps, node, i) {
2026 		if (i >= ARRAY_SIZE(selinux_policycap_names))
2027 			pr_info("SELinux:  unknown policy capability %u\n",
2028 				i);
2029 	}
2030 
2031 	selinux_android_netlink_route = policydb.android_netlink_route;
2032 	selinux_nlmsg_init();
2033 }
2034 
2035 static int security_preserve_bools(struct policydb *p);
2036 
2037 /**
2038  * security_load_policy - Load a security policy configuration.
2039  * @data: binary policy data
2040  * @len: length of data in bytes
2041  *
2042  * Load a new set of security policy configuration data,
2043  * validate it and convert the SID table as necessary.
2044  * This function will flush the access vector cache after
2045  * loading the new policy.
2046  */
security_load_policy(void * data,size_t len)2047 int security_load_policy(void *data, size_t len)
2048 {
2049 	struct policydb *oldpolicydb, *newpolicydb;
2050 	struct sidtab oldsidtab, newsidtab;
2051 	struct selinux_mapping *oldmap, *map = NULL;
2052 	struct convert_context_args args;
2053 	u32 seqno;
2054 	u16 map_size;
2055 	int rc = 0;
2056 	struct policy_file file = { data, len }, *fp = &file;
2057 
2058 	oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2059 	if (!oldpolicydb) {
2060 		rc = -ENOMEM;
2061 		goto out;
2062 	}
2063 	newpolicydb = oldpolicydb + 1;
2064 
2065 	if (!ss_initialized) {
2066 		avtab_cache_init();
2067 		ebitmap_cache_init();
2068 		rc = policydb_read(&policydb, fp);
2069 		if (rc) {
2070 			avtab_cache_destroy();
2071 			ebitmap_cache_destroy();
2072 			goto out;
2073 		}
2074 
2075 		policydb.len = len;
2076 		rc = selinux_set_mapping(&policydb, secclass_map,
2077 					 &current_mapping,
2078 					 &current_mapping_size);
2079 		if (rc) {
2080 			policydb_destroy(&policydb);
2081 			avtab_cache_destroy();
2082 			ebitmap_cache_destroy();
2083 			goto out;
2084 		}
2085 
2086 		rc = policydb_load_isids(&policydb, &sidtab);
2087 		if (rc) {
2088 			policydb_destroy(&policydb);
2089 			avtab_cache_destroy();
2090 			ebitmap_cache_destroy();
2091 			goto out;
2092 		}
2093 
2094 		security_load_policycaps();
2095 		ss_initialized = 1;
2096 		seqno = ++latest_granting;
2097 		selinux_complete_init();
2098 		avc_ss_reset(seqno);
2099 		selnl_notify_policyload(seqno);
2100 		selinux_status_update_policyload(seqno);
2101 		selinux_netlbl_cache_invalidate();
2102 		selinux_xfrm_notify_policyload();
2103 		goto out;
2104 	}
2105 
2106 #if 0
2107 	sidtab_hash_eval(&sidtab, "sids");
2108 #endif
2109 
2110 	rc = policydb_read(newpolicydb, fp);
2111 	if (rc)
2112 		goto out;
2113 
2114 	newpolicydb->len = len;
2115 	/* If switching between different policy types, log MLS status */
2116 	if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2117 		printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2118 	else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2119 		printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2120 
2121 	rc = policydb_load_isids(newpolicydb, &newsidtab);
2122 	if (rc) {
2123 		printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2124 		policydb_destroy(newpolicydb);
2125 		goto out;
2126 	}
2127 
2128 	rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2129 	if (rc)
2130 		goto err;
2131 
2132 	rc = security_preserve_bools(newpolicydb);
2133 	if (rc) {
2134 		printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2135 		goto err;
2136 	}
2137 
2138 	/* Clone the SID table. */
2139 	sidtab_shutdown(&sidtab);
2140 
2141 	rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2142 	if (rc)
2143 		goto err;
2144 
2145 	/*
2146 	 * Convert the internal representations of contexts
2147 	 * in the new SID table.
2148 	 */
2149 	args.oldp = &policydb;
2150 	args.newp = newpolicydb;
2151 	rc = sidtab_map(&newsidtab, convert_context, &args);
2152 	if (rc) {
2153 		printk(KERN_ERR "SELinux:  unable to convert the internal"
2154 			" representation of contexts in the new SID"
2155 			" table\n");
2156 		goto err;
2157 	}
2158 
2159 	/* Save the old policydb and SID table to free later. */
2160 	memcpy(oldpolicydb, &policydb, sizeof(policydb));
2161 	sidtab_set(&oldsidtab, &sidtab);
2162 
2163 	/* Install the new policydb and SID table. */
2164 	write_lock_irq(&policy_rwlock);
2165 	memcpy(&policydb, newpolicydb, sizeof(policydb));
2166 	sidtab_set(&sidtab, &newsidtab);
2167 	security_load_policycaps();
2168 	oldmap = current_mapping;
2169 	current_mapping = map;
2170 	current_mapping_size = map_size;
2171 	seqno = ++latest_granting;
2172 	write_unlock_irq(&policy_rwlock);
2173 
2174 	/* Free the old policydb and SID table. */
2175 	policydb_destroy(oldpolicydb);
2176 	sidtab_destroy(&oldsidtab);
2177 	kfree(oldmap);
2178 
2179 	avc_ss_reset(seqno);
2180 	selnl_notify_policyload(seqno);
2181 	selinux_status_update_policyload(seqno);
2182 	selinux_netlbl_cache_invalidate();
2183 	selinux_xfrm_notify_policyload();
2184 
2185 	rc = 0;
2186 	goto out;
2187 
2188 err:
2189 	kfree(map);
2190 	sidtab_destroy(&newsidtab);
2191 	policydb_destroy(newpolicydb);
2192 
2193 out:
2194 	kfree(oldpolicydb);
2195 	return rc;
2196 }
2197 
security_policydb_len(void)2198 size_t security_policydb_len(void)
2199 {
2200 	size_t len;
2201 
2202 	read_lock(&policy_rwlock);
2203 	len = policydb.len;
2204 	read_unlock(&policy_rwlock);
2205 
2206 	return len;
2207 }
2208 
2209 /**
2210  * security_port_sid - Obtain the SID for a port.
2211  * @protocol: protocol number
2212  * @port: port number
2213  * @out_sid: security identifier
2214  */
security_port_sid(u8 protocol,u16 port,u32 * out_sid)2215 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2216 {
2217 	struct ocontext *c;
2218 	int rc = 0;
2219 
2220 	read_lock(&policy_rwlock);
2221 
2222 	c = policydb.ocontexts[OCON_PORT];
2223 	while (c) {
2224 		if (c->u.port.protocol == protocol &&
2225 		    c->u.port.low_port <= port &&
2226 		    c->u.port.high_port >= port)
2227 			break;
2228 		c = c->next;
2229 	}
2230 
2231 	if (c) {
2232 		if (!c->sid[0]) {
2233 			rc = sidtab_context_to_sid(&sidtab,
2234 						   &c->context[0],
2235 						   &c->sid[0]);
2236 			if (rc)
2237 				goto out;
2238 		}
2239 		*out_sid = c->sid[0];
2240 	} else {
2241 		*out_sid = SECINITSID_PORT;
2242 	}
2243 
2244 out:
2245 	read_unlock(&policy_rwlock);
2246 	return rc;
2247 }
2248 
2249 /**
2250  * security_pkey_sid - Obtain the SID for a pkey.
2251  * @subnet_prefix: Subnet Prefix
2252  * @pkey_num: pkey number
2253  * @out_sid: security identifier
2254  */
security_ib_pkey_sid(u64 subnet_prefix,u16 pkey_num,u32 * out_sid)2255 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2256 {
2257 	struct ocontext *c;
2258 	int rc = 0;
2259 
2260 	read_lock(&policy_rwlock);
2261 
2262 	c = policydb.ocontexts[OCON_IBPKEY];
2263 	while (c) {
2264 		if (c->u.ibpkey.low_pkey <= pkey_num &&
2265 		    c->u.ibpkey.high_pkey >= pkey_num &&
2266 		    c->u.ibpkey.subnet_prefix == subnet_prefix)
2267 			break;
2268 
2269 		c = c->next;
2270 	}
2271 
2272 	if (c) {
2273 		if (!c->sid[0]) {
2274 			rc = sidtab_context_to_sid(&sidtab,
2275 						   &c->context[0],
2276 						   &c->sid[0]);
2277 			if (rc)
2278 				goto out;
2279 		}
2280 		*out_sid = c->sid[0];
2281 	} else
2282 		*out_sid = SECINITSID_UNLABELED;
2283 
2284 out:
2285 	read_unlock(&policy_rwlock);
2286 	return rc;
2287 }
2288 
2289 /**
2290  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2291  * @dev_name: device name
2292  * @port: port number
2293  * @out_sid: security identifier
2294  */
security_ib_endport_sid(const char * dev_name,u8 port_num,u32 * out_sid)2295 int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid)
2296 {
2297 	struct ocontext *c;
2298 	int rc = 0;
2299 
2300 	read_lock(&policy_rwlock);
2301 
2302 	c = policydb.ocontexts[OCON_IBENDPORT];
2303 	while (c) {
2304 		if (c->u.ibendport.port == port_num &&
2305 		    !strncmp(c->u.ibendport.dev_name,
2306 			     dev_name,
2307 			     IB_DEVICE_NAME_MAX))
2308 			break;
2309 
2310 		c = c->next;
2311 	}
2312 
2313 	if (c) {
2314 		if (!c->sid[0]) {
2315 			rc = sidtab_context_to_sid(&sidtab,
2316 						   &c->context[0],
2317 						   &c->sid[0]);
2318 			if (rc)
2319 				goto out;
2320 		}
2321 		*out_sid = c->sid[0];
2322 	} else
2323 		*out_sid = SECINITSID_UNLABELED;
2324 
2325 out:
2326 	read_unlock(&policy_rwlock);
2327 	return rc;
2328 }
2329 
2330 /**
2331  * security_netif_sid - Obtain the SID for a network interface.
2332  * @name: interface name
2333  * @if_sid: interface SID
2334  */
security_netif_sid(char * name,u32 * if_sid)2335 int security_netif_sid(char *name, u32 *if_sid)
2336 {
2337 	int rc = 0;
2338 	struct ocontext *c;
2339 
2340 	read_lock(&policy_rwlock);
2341 
2342 	c = policydb.ocontexts[OCON_NETIF];
2343 	while (c) {
2344 		if (strcmp(name, c->u.name) == 0)
2345 			break;
2346 		c = c->next;
2347 	}
2348 
2349 	if (c) {
2350 		if (!c->sid[0] || !c->sid[1]) {
2351 			rc = sidtab_context_to_sid(&sidtab,
2352 						  &c->context[0],
2353 						  &c->sid[0]);
2354 			if (rc)
2355 				goto out;
2356 			rc = sidtab_context_to_sid(&sidtab,
2357 						   &c->context[1],
2358 						   &c->sid[1]);
2359 			if (rc)
2360 				goto out;
2361 		}
2362 		*if_sid = c->sid[0];
2363 	} else
2364 		*if_sid = SECINITSID_NETIF;
2365 
2366 out:
2367 	read_unlock(&policy_rwlock);
2368 	return rc;
2369 }
2370 
match_ipv6_addrmask(u32 * input,u32 * addr,u32 * mask)2371 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2372 {
2373 	int i, fail = 0;
2374 
2375 	for (i = 0; i < 4; i++)
2376 		if (addr[i] != (input[i] & mask[i])) {
2377 			fail = 1;
2378 			break;
2379 		}
2380 
2381 	return !fail;
2382 }
2383 
2384 /**
2385  * security_node_sid - Obtain the SID for a node (host).
2386  * @domain: communication domain aka address family
2387  * @addrp: address
2388  * @addrlen: address length in bytes
2389  * @out_sid: security identifier
2390  */
security_node_sid(u16 domain,void * addrp,u32 addrlen,u32 * out_sid)2391 int security_node_sid(u16 domain,
2392 		      void *addrp,
2393 		      u32 addrlen,
2394 		      u32 *out_sid)
2395 {
2396 	int rc;
2397 	struct ocontext *c;
2398 
2399 	read_lock(&policy_rwlock);
2400 
2401 	switch (domain) {
2402 	case AF_INET: {
2403 		u32 addr;
2404 
2405 		rc = -EINVAL;
2406 		if (addrlen != sizeof(u32))
2407 			goto out;
2408 
2409 		addr = *((u32 *)addrp);
2410 
2411 		c = policydb.ocontexts[OCON_NODE];
2412 		while (c) {
2413 			if (c->u.node.addr == (addr & c->u.node.mask))
2414 				break;
2415 			c = c->next;
2416 		}
2417 		break;
2418 	}
2419 
2420 	case AF_INET6:
2421 		rc = -EINVAL;
2422 		if (addrlen != sizeof(u64) * 2)
2423 			goto out;
2424 		c = policydb.ocontexts[OCON_NODE6];
2425 		while (c) {
2426 			if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2427 						c->u.node6.mask))
2428 				break;
2429 			c = c->next;
2430 		}
2431 		break;
2432 
2433 	default:
2434 		rc = 0;
2435 		*out_sid = SECINITSID_NODE;
2436 		goto out;
2437 	}
2438 
2439 	if (c) {
2440 		if (!c->sid[0]) {
2441 			rc = sidtab_context_to_sid(&sidtab,
2442 						   &c->context[0],
2443 						   &c->sid[0]);
2444 			if (rc)
2445 				goto out;
2446 		}
2447 		*out_sid = c->sid[0];
2448 	} else {
2449 		*out_sid = SECINITSID_NODE;
2450 	}
2451 
2452 	rc = 0;
2453 out:
2454 	read_unlock(&policy_rwlock);
2455 	return rc;
2456 }
2457 
2458 #define SIDS_NEL 25
2459 
2460 /**
2461  * security_get_user_sids - Obtain reachable SIDs for a user.
2462  * @fromsid: starting SID
2463  * @username: username
2464  * @sids: array of reachable SIDs for user
2465  * @nel: number of elements in @sids
2466  *
2467  * Generate the set of SIDs for legal security contexts
2468  * for a given user that can be reached by @fromsid.
2469  * Set *@sids to point to a dynamically allocated
2470  * array containing the set of SIDs.  Set *@nel to the
2471  * number of elements in the array.
2472  */
2473 
security_get_user_sids(u32 fromsid,char * username,u32 ** sids,u32 * nel)2474 int security_get_user_sids(u32 fromsid,
2475 			   char *username,
2476 			   u32 **sids,
2477 			   u32 *nel)
2478 {
2479 	struct context *fromcon, usercon;
2480 	u32 *mysids = NULL, *mysids2, sid;
2481 	u32 mynel = 0, maxnel = SIDS_NEL;
2482 	struct user_datum *user;
2483 	struct role_datum *role;
2484 	struct ebitmap_node *rnode, *tnode;
2485 	int rc = 0, i, j;
2486 
2487 	*sids = NULL;
2488 	*nel = 0;
2489 
2490 	if (!ss_initialized)
2491 		goto out;
2492 
2493 	read_lock(&policy_rwlock);
2494 
2495 	context_init(&usercon);
2496 
2497 	rc = -EINVAL;
2498 	fromcon = sidtab_search(&sidtab, fromsid);
2499 	if (!fromcon)
2500 		goto out_unlock;
2501 
2502 	rc = -EINVAL;
2503 	user = hashtab_search(policydb.p_users.table, username);
2504 	if (!user)
2505 		goto out_unlock;
2506 
2507 	usercon.user = user->value;
2508 
2509 	rc = -ENOMEM;
2510 	mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2511 	if (!mysids)
2512 		goto out_unlock;
2513 
2514 	ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2515 		role = policydb.role_val_to_struct[i];
2516 		usercon.role = i + 1;
2517 		ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2518 			usercon.type = j + 1;
2519 
2520 			if (mls_setup_user_range(fromcon, user, &usercon))
2521 				continue;
2522 
2523 			rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2524 			if (rc)
2525 				goto out_unlock;
2526 			if (mynel < maxnel) {
2527 				mysids[mynel++] = sid;
2528 			} else {
2529 				rc = -ENOMEM;
2530 				maxnel += SIDS_NEL;
2531 				mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2532 				if (!mysids2)
2533 					goto out_unlock;
2534 				memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2535 				kfree(mysids);
2536 				mysids = mysids2;
2537 				mysids[mynel++] = sid;
2538 			}
2539 		}
2540 	}
2541 	rc = 0;
2542 out_unlock:
2543 	read_unlock(&policy_rwlock);
2544 	if (rc || !mynel) {
2545 		kfree(mysids);
2546 		goto out;
2547 	}
2548 
2549 	rc = -ENOMEM;
2550 	mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2551 	if (!mysids2) {
2552 		kfree(mysids);
2553 		goto out;
2554 	}
2555 	for (i = 0, j = 0; i < mynel; i++) {
2556 		struct av_decision dummy_avd;
2557 		rc = avc_has_perm_noaudit(fromsid, mysids[i],
2558 					  SECCLASS_PROCESS, /* kernel value */
2559 					  PROCESS__TRANSITION, AVC_STRICT,
2560 					  &dummy_avd);
2561 		if (!rc)
2562 			mysids2[j++] = mysids[i];
2563 		cond_resched();
2564 	}
2565 	rc = 0;
2566 	kfree(mysids);
2567 	*sids = mysids2;
2568 	*nel = j;
2569 out:
2570 	return rc;
2571 }
2572 
2573 /**
2574  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2575  * @fstype: filesystem type
2576  * @path: path from root of mount
2577  * @sclass: file security class
2578  * @sid: SID for path
2579  *
2580  * Obtain a SID to use for a file in a filesystem that
2581  * cannot support xattr or use a fixed labeling behavior like
2582  * transition SIDs or task SIDs.
2583  *
2584  * The caller must acquire the policy_rwlock before calling this function.
2585  */
__security_genfs_sid(const char * fstype,char * path,u16 orig_sclass,u32 * sid)2586 static inline int __security_genfs_sid(const char *fstype,
2587 				       char *path,
2588 				       u16 orig_sclass,
2589 				       u32 *sid)
2590 {
2591 	int len;
2592 	u16 sclass;
2593 	struct genfs *genfs;
2594 	struct ocontext *c;
2595 	int rc, cmp = 0;
2596 
2597 	while (path[0] == '/' && path[1] == '/')
2598 		path++;
2599 
2600 	sclass = unmap_class(orig_sclass);
2601 	*sid = SECINITSID_UNLABELED;
2602 
2603 	for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2604 		cmp = strcmp(fstype, genfs->fstype);
2605 		if (cmp <= 0)
2606 			break;
2607 	}
2608 
2609 	rc = -ENOENT;
2610 	if (!genfs || cmp)
2611 		goto out;
2612 
2613 	for (c = genfs->head; c; c = c->next) {
2614 		len = strlen(c->u.name);
2615 		if ((!c->v.sclass || sclass == c->v.sclass) &&
2616 		    (strncmp(c->u.name, path, len) == 0))
2617 			break;
2618 	}
2619 
2620 	rc = -ENOENT;
2621 	if (!c)
2622 		goto out;
2623 
2624 	if (!c->sid[0]) {
2625 		rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2626 		if (rc)
2627 			goto out;
2628 	}
2629 
2630 	*sid = c->sid[0];
2631 	rc = 0;
2632 out:
2633 	return rc;
2634 }
2635 
2636 /**
2637  * security_genfs_sid - Obtain a SID for a file in a filesystem
2638  * @fstype: filesystem type
2639  * @path: path from root of mount
2640  * @sclass: file security class
2641  * @sid: SID for path
2642  *
2643  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2644  * it afterward.
2645  */
security_genfs_sid(const char * fstype,char * path,u16 orig_sclass,u32 * sid)2646 int security_genfs_sid(const char *fstype,
2647 		       char *path,
2648 		       u16 orig_sclass,
2649 		       u32 *sid)
2650 {
2651 	int retval;
2652 
2653 	read_lock(&policy_rwlock);
2654 	retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2655 	read_unlock(&policy_rwlock);
2656 	return retval;
2657 }
2658 
2659 /**
2660  * security_fs_use - Determine how to handle labeling for a filesystem.
2661  * @sb: superblock in question
2662  */
security_fs_use(struct super_block * sb)2663 int security_fs_use(struct super_block *sb)
2664 {
2665 	int rc = 0;
2666 	struct ocontext *c;
2667 	struct superblock_security_struct *sbsec = sb->s_security;
2668 	const char *fstype = sb->s_type->name;
2669 
2670 	read_lock(&policy_rwlock);
2671 
2672 	c = policydb.ocontexts[OCON_FSUSE];
2673 	while (c) {
2674 		if (strcmp(fstype, c->u.name) == 0)
2675 			break;
2676 		c = c->next;
2677 	}
2678 
2679 	if (c) {
2680 		sbsec->behavior = c->v.behavior;
2681 		if (!c->sid[0]) {
2682 			rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2683 						   &c->sid[0]);
2684 			if (rc)
2685 				goto out;
2686 		}
2687 		sbsec->sid = c->sid[0];
2688 	} else {
2689 		rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2690 					  &sbsec->sid);
2691 		if (rc) {
2692 			sbsec->behavior = SECURITY_FS_USE_NONE;
2693 			rc = 0;
2694 		} else {
2695 			sbsec->behavior = SECURITY_FS_USE_GENFS;
2696 		}
2697 	}
2698 
2699 out:
2700 	read_unlock(&policy_rwlock);
2701 	return rc;
2702 }
2703 
security_get_bools(int * len,char *** names,int ** values)2704 int security_get_bools(int *len, char ***names, int **values)
2705 {
2706 	int i, rc;
2707 
2708 	read_lock(&policy_rwlock);
2709 	*names = NULL;
2710 	*values = NULL;
2711 
2712 	rc = 0;
2713 	*len = policydb.p_bools.nprim;
2714 	if (!*len)
2715 		goto out;
2716 
2717 	rc = -ENOMEM;
2718 	*names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2719 	if (!*names)
2720 		goto err;
2721 
2722 	rc = -ENOMEM;
2723 	*values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2724 	if (!*values)
2725 		goto err;
2726 
2727 	for (i = 0; i < *len; i++) {
2728 		(*values)[i] = policydb.bool_val_to_struct[i]->state;
2729 
2730 		rc = -ENOMEM;
2731 		(*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2732 		if (!(*names)[i])
2733 			goto err;
2734 	}
2735 	rc = 0;
2736 out:
2737 	read_unlock(&policy_rwlock);
2738 	return rc;
2739 err:
2740 	if (*names) {
2741 		for (i = 0; i < *len; i++)
2742 			kfree((*names)[i]);
2743 	}
2744 	kfree(*values);
2745 	goto out;
2746 }
2747 
2748 
security_set_bools(int len,int * values)2749 int security_set_bools(int len, int *values)
2750 {
2751 	int i, rc;
2752 	int lenp, seqno = 0;
2753 	struct cond_node *cur;
2754 
2755 	write_lock_irq(&policy_rwlock);
2756 
2757 	rc = -EFAULT;
2758 	lenp = policydb.p_bools.nprim;
2759 	if (len != lenp)
2760 		goto out;
2761 
2762 	for (i = 0; i < len; i++) {
2763 		if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2764 			audit_log(current->audit_context, GFP_ATOMIC,
2765 				AUDIT_MAC_CONFIG_CHANGE,
2766 				"bool=%s val=%d old_val=%d auid=%u ses=%u",
2767 				sym_name(&policydb, SYM_BOOLS, i),
2768 				!!values[i],
2769 				policydb.bool_val_to_struct[i]->state,
2770 				from_kuid(&init_user_ns, audit_get_loginuid(current)),
2771 				audit_get_sessionid(current));
2772 		}
2773 		if (values[i])
2774 			policydb.bool_val_to_struct[i]->state = 1;
2775 		else
2776 			policydb.bool_val_to_struct[i]->state = 0;
2777 	}
2778 
2779 	for (cur = policydb.cond_list; cur; cur = cur->next) {
2780 		rc = evaluate_cond_node(&policydb, cur);
2781 		if (rc)
2782 			goto out;
2783 	}
2784 
2785 	seqno = ++latest_granting;
2786 	rc = 0;
2787 out:
2788 	write_unlock_irq(&policy_rwlock);
2789 	if (!rc) {
2790 		avc_ss_reset(seqno);
2791 		selnl_notify_policyload(seqno);
2792 		selinux_status_update_policyload(seqno);
2793 		selinux_xfrm_notify_policyload();
2794 	}
2795 	return rc;
2796 }
2797 
security_get_bool_value(int index)2798 int security_get_bool_value(int index)
2799 {
2800 	int rc;
2801 	int len;
2802 
2803 	read_lock(&policy_rwlock);
2804 
2805 	rc = -EFAULT;
2806 	len = policydb.p_bools.nprim;
2807 	if (index >= len)
2808 		goto out;
2809 
2810 	rc = policydb.bool_val_to_struct[index]->state;
2811 out:
2812 	read_unlock(&policy_rwlock);
2813 	return rc;
2814 }
2815 
security_preserve_bools(struct policydb * p)2816 static int security_preserve_bools(struct policydb *p)
2817 {
2818 	int rc, nbools = 0, *bvalues = NULL, i;
2819 	char **bnames = NULL;
2820 	struct cond_bool_datum *booldatum;
2821 	struct cond_node *cur;
2822 
2823 	rc = security_get_bools(&nbools, &bnames, &bvalues);
2824 	if (rc)
2825 		goto out;
2826 	for (i = 0; i < nbools; i++) {
2827 		booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2828 		if (booldatum)
2829 			booldatum->state = bvalues[i];
2830 	}
2831 	for (cur = p->cond_list; cur; cur = cur->next) {
2832 		rc = evaluate_cond_node(p, cur);
2833 		if (rc)
2834 			goto out;
2835 	}
2836 
2837 out:
2838 	if (bnames) {
2839 		for (i = 0; i < nbools; i++)
2840 			kfree(bnames[i]);
2841 	}
2842 	kfree(bnames);
2843 	kfree(bvalues);
2844 	return rc;
2845 }
2846 
2847 /*
2848  * security_sid_mls_copy() - computes a new sid based on the given
2849  * sid and the mls portion of mls_sid.
2850  */
security_sid_mls_copy(u32 sid,u32 mls_sid,u32 * new_sid)2851 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2852 {
2853 	struct context *context1;
2854 	struct context *context2;
2855 	struct context newcon;
2856 	char *s;
2857 	u32 len;
2858 	int rc;
2859 
2860 	rc = 0;
2861 	if (!ss_initialized || !policydb.mls_enabled) {
2862 		*new_sid = sid;
2863 		goto out;
2864 	}
2865 
2866 	context_init(&newcon);
2867 
2868 	read_lock(&policy_rwlock);
2869 
2870 	rc = -EINVAL;
2871 	context1 = sidtab_search(&sidtab, sid);
2872 	if (!context1) {
2873 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2874 			__func__, sid);
2875 		goto out_unlock;
2876 	}
2877 
2878 	rc = -EINVAL;
2879 	context2 = sidtab_search(&sidtab, mls_sid);
2880 	if (!context2) {
2881 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2882 			__func__, mls_sid);
2883 		goto out_unlock;
2884 	}
2885 
2886 	newcon.user = context1->user;
2887 	newcon.role = context1->role;
2888 	newcon.type = context1->type;
2889 	rc = mls_context_cpy(&newcon, context2);
2890 	if (rc)
2891 		goto out_unlock;
2892 
2893 	/* Check the validity of the new context. */
2894 	if (!policydb_context_isvalid(&policydb, &newcon)) {
2895 		rc = convert_context_handle_invalid_context(&newcon);
2896 		if (rc) {
2897 			if (!context_struct_to_string(&newcon, &s, &len)) {
2898 				audit_log(current->audit_context,
2899 					  GFP_ATOMIC, AUDIT_SELINUX_ERR,
2900 					  "op=security_sid_mls_copy "
2901 					  "invalid_context=%s", s);
2902 				kfree(s);
2903 			}
2904 			goto out_unlock;
2905 		}
2906 	}
2907 
2908 	rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2909 out_unlock:
2910 	read_unlock(&policy_rwlock);
2911 	context_destroy(&newcon);
2912 out:
2913 	return rc;
2914 }
2915 
2916 /**
2917  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2918  * @nlbl_sid: NetLabel SID
2919  * @nlbl_type: NetLabel labeling protocol type
2920  * @xfrm_sid: XFRM SID
2921  *
2922  * Description:
2923  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2924  * resolved into a single SID it is returned via @peer_sid and the function
2925  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2926  * returns a negative value.  A table summarizing the behavior is below:
2927  *
2928  *                                 | function return |      @sid
2929  *   ------------------------------+-----------------+-----------------
2930  *   no peer labels                |        0        |    SECSID_NULL
2931  *   single peer label             |        0        |    <peer_label>
2932  *   multiple, consistent labels   |        0        |    <peer_label>
2933  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2934  *
2935  */
security_net_peersid_resolve(u32 nlbl_sid,u32 nlbl_type,u32 xfrm_sid,u32 * peer_sid)2936 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2937 				 u32 xfrm_sid,
2938 				 u32 *peer_sid)
2939 {
2940 	int rc;
2941 	struct context *nlbl_ctx;
2942 	struct context *xfrm_ctx;
2943 
2944 	*peer_sid = SECSID_NULL;
2945 
2946 	/* handle the common (which also happens to be the set of easy) cases
2947 	 * right away, these two if statements catch everything involving a
2948 	 * single or absent peer SID/label */
2949 	if (xfrm_sid == SECSID_NULL) {
2950 		*peer_sid = nlbl_sid;
2951 		return 0;
2952 	}
2953 	/* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2954 	 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2955 	 * is present */
2956 	if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2957 		*peer_sid = xfrm_sid;
2958 		return 0;
2959 	}
2960 
2961 	/* we don't need to check ss_initialized here since the only way both
2962 	 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2963 	 * security server was initialized and ss_initialized was true */
2964 	if (!policydb.mls_enabled)
2965 		return 0;
2966 
2967 	read_lock(&policy_rwlock);
2968 
2969 	rc = -EINVAL;
2970 	nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2971 	if (!nlbl_ctx) {
2972 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2973 		       __func__, nlbl_sid);
2974 		goto out;
2975 	}
2976 	rc = -EINVAL;
2977 	xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2978 	if (!xfrm_ctx) {
2979 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2980 		       __func__, xfrm_sid);
2981 		goto out;
2982 	}
2983 	rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2984 	if (rc)
2985 		goto out;
2986 
2987 	/* at present NetLabel SIDs/labels really only carry MLS
2988 	 * information so if the MLS portion of the NetLabel SID
2989 	 * matches the MLS portion of the labeled XFRM SID/label
2990 	 * then pass along the XFRM SID as it is the most
2991 	 * expressive */
2992 	*peer_sid = xfrm_sid;
2993 out:
2994 	read_unlock(&policy_rwlock);
2995 	return rc;
2996 }
2997 
get_classes_callback(void * k,void * d,void * args)2998 static int get_classes_callback(void *k, void *d, void *args)
2999 {
3000 	struct class_datum *datum = d;
3001 	char *name = k, **classes = args;
3002 	int value = datum->value - 1;
3003 
3004 	classes[value] = kstrdup(name, GFP_ATOMIC);
3005 	if (!classes[value])
3006 		return -ENOMEM;
3007 
3008 	return 0;
3009 }
3010 
security_get_classes(char *** classes,int * nclasses)3011 int security_get_classes(char ***classes, int *nclasses)
3012 {
3013 	int rc;
3014 
3015 	read_lock(&policy_rwlock);
3016 
3017 	rc = -ENOMEM;
3018 	*nclasses = policydb.p_classes.nprim;
3019 	*classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3020 	if (!*classes)
3021 		goto out;
3022 
3023 	rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
3024 			*classes);
3025 	if (rc) {
3026 		int i;
3027 		for (i = 0; i < *nclasses; i++)
3028 			kfree((*classes)[i]);
3029 		kfree(*classes);
3030 	}
3031 
3032 out:
3033 	read_unlock(&policy_rwlock);
3034 	return rc;
3035 }
3036 
get_permissions_callback(void * k,void * d,void * args)3037 static int get_permissions_callback(void *k, void *d, void *args)
3038 {
3039 	struct perm_datum *datum = d;
3040 	char *name = k, **perms = args;
3041 	int value = datum->value - 1;
3042 
3043 	perms[value] = kstrdup(name, GFP_ATOMIC);
3044 	if (!perms[value])
3045 		return -ENOMEM;
3046 
3047 	return 0;
3048 }
3049 
security_get_permissions(char * class,char *** perms,int * nperms)3050 int security_get_permissions(char *class, char ***perms, int *nperms)
3051 {
3052 	int rc, i;
3053 	struct class_datum *match;
3054 
3055 	read_lock(&policy_rwlock);
3056 
3057 	rc = -EINVAL;
3058 	match = hashtab_search(policydb.p_classes.table, class);
3059 	if (!match) {
3060 		printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
3061 			__func__, class);
3062 		goto out;
3063 	}
3064 
3065 	rc = -ENOMEM;
3066 	*nperms = match->permissions.nprim;
3067 	*perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3068 	if (!*perms)
3069 		goto out;
3070 
3071 	if (match->comdatum) {
3072 		rc = hashtab_map(match->comdatum->permissions.table,
3073 				get_permissions_callback, *perms);
3074 		if (rc)
3075 			goto err;
3076 	}
3077 
3078 	rc = hashtab_map(match->permissions.table, get_permissions_callback,
3079 			*perms);
3080 	if (rc)
3081 		goto err;
3082 
3083 out:
3084 	read_unlock(&policy_rwlock);
3085 	return rc;
3086 
3087 err:
3088 	read_unlock(&policy_rwlock);
3089 	for (i = 0; i < *nperms; i++)
3090 		kfree((*perms)[i]);
3091 	kfree(*perms);
3092 	return rc;
3093 }
3094 
security_get_reject_unknown(void)3095 int security_get_reject_unknown(void)
3096 {
3097 	return policydb.reject_unknown;
3098 }
3099 
security_get_allow_unknown(void)3100 int security_get_allow_unknown(void)
3101 {
3102 	return policydb.allow_unknown;
3103 }
3104 
3105 /**
3106  * security_policycap_supported - Check for a specific policy capability
3107  * @req_cap: capability
3108  *
3109  * Description:
3110  * This function queries the currently loaded policy to see if it supports the
3111  * capability specified by @req_cap.  Returns true (1) if the capability is
3112  * supported, false (0) if it isn't supported.
3113  *
3114  */
security_policycap_supported(unsigned int req_cap)3115 int security_policycap_supported(unsigned int req_cap)
3116 {
3117 	int rc;
3118 
3119 	read_lock(&policy_rwlock);
3120 	rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3121 	read_unlock(&policy_rwlock);
3122 
3123 	return rc;
3124 }
3125 
3126 struct selinux_audit_rule {
3127 	u32 au_seqno;
3128 	struct context au_ctxt;
3129 };
3130 
selinux_audit_rule_free(void * vrule)3131 void selinux_audit_rule_free(void *vrule)
3132 {
3133 	struct selinux_audit_rule *rule = vrule;
3134 
3135 	if (rule) {
3136 		context_destroy(&rule->au_ctxt);
3137 		kfree(rule);
3138 	}
3139 }
3140 
selinux_audit_rule_init(u32 field,u32 op,char * rulestr,void ** vrule)3141 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3142 {
3143 	struct selinux_audit_rule *tmprule;
3144 	struct role_datum *roledatum;
3145 	struct type_datum *typedatum;
3146 	struct user_datum *userdatum;
3147 	struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3148 	int rc = 0;
3149 
3150 	*rule = NULL;
3151 
3152 	if (!ss_initialized)
3153 		return -EOPNOTSUPP;
3154 
3155 	switch (field) {
3156 	case AUDIT_SUBJ_USER:
3157 	case AUDIT_SUBJ_ROLE:
3158 	case AUDIT_SUBJ_TYPE:
3159 	case AUDIT_OBJ_USER:
3160 	case AUDIT_OBJ_ROLE:
3161 	case AUDIT_OBJ_TYPE:
3162 		/* only 'equals' and 'not equals' fit user, role, and type */
3163 		if (op != Audit_equal && op != Audit_not_equal)
3164 			return -EINVAL;
3165 		break;
3166 	case AUDIT_SUBJ_SEN:
3167 	case AUDIT_SUBJ_CLR:
3168 	case AUDIT_OBJ_LEV_LOW:
3169 	case AUDIT_OBJ_LEV_HIGH:
3170 		/* we do not allow a range, indicated by the presence of '-' */
3171 		if (strchr(rulestr, '-'))
3172 			return -EINVAL;
3173 		break;
3174 	default:
3175 		/* only the above fields are valid */
3176 		return -EINVAL;
3177 	}
3178 
3179 	tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3180 	if (!tmprule)
3181 		return -ENOMEM;
3182 
3183 	context_init(&tmprule->au_ctxt);
3184 
3185 	read_lock(&policy_rwlock);
3186 
3187 	tmprule->au_seqno = latest_granting;
3188 
3189 	switch (field) {
3190 	case AUDIT_SUBJ_USER:
3191 	case AUDIT_OBJ_USER:
3192 		rc = -EINVAL;
3193 		userdatum = hashtab_search(policydb.p_users.table, rulestr);
3194 		if (!userdatum)
3195 			goto out;
3196 		tmprule->au_ctxt.user = userdatum->value;
3197 		break;
3198 	case AUDIT_SUBJ_ROLE:
3199 	case AUDIT_OBJ_ROLE:
3200 		rc = -EINVAL;
3201 		roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3202 		if (!roledatum)
3203 			goto out;
3204 		tmprule->au_ctxt.role = roledatum->value;
3205 		break;
3206 	case AUDIT_SUBJ_TYPE:
3207 	case AUDIT_OBJ_TYPE:
3208 		rc = -EINVAL;
3209 		typedatum = hashtab_search(policydb.p_types.table, rulestr);
3210 		if (!typedatum)
3211 			goto out;
3212 		tmprule->au_ctxt.type = typedatum->value;
3213 		break;
3214 	case AUDIT_SUBJ_SEN:
3215 	case AUDIT_SUBJ_CLR:
3216 	case AUDIT_OBJ_LEV_LOW:
3217 	case AUDIT_OBJ_LEV_HIGH:
3218 		rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3219 		if (rc)
3220 			goto out;
3221 		break;
3222 	}
3223 	rc = 0;
3224 out:
3225 	read_unlock(&policy_rwlock);
3226 
3227 	if (rc) {
3228 		selinux_audit_rule_free(tmprule);
3229 		tmprule = NULL;
3230 	}
3231 
3232 	*rule = tmprule;
3233 
3234 	return rc;
3235 }
3236 
3237 /* Check to see if the rule contains any selinux fields */
selinux_audit_rule_known(struct audit_krule * rule)3238 int selinux_audit_rule_known(struct audit_krule *rule)
3239 {
3240 	int i;
3241 
3242 	for (i = 0; i < rule->field_count; i++) {
3243 		struct audit_field *f = &rule->fields[i];
3244 		switch (f->type) {
3245 		case AUDIT_SUBJ_USER:
3246 		case AUDIT_SUBJ_ROLE:
3247 		case AUDIT_SUBJ_TYPE:
3248 		case AUDIT_SUBJ_SEN:
3249 		case AUDIT_SUBJ_CLR:
3250 		case AUDIT_OBJ_USER:
3251 		case AUDIT_OBJ_ROLE:
3252 		case AUDIT_OBJ_TYPE:
3253 		case AUDIT_OBJ_LEV_LOW:
3254 		case AUDIT_OBJ_LEV_HIGH:
3255 			return 1;
3256 		}
3257 	}
3258 
3259 	return 0;
3260 }
3261 
selinux_audit_rule_match(u32 sid,u32 field,u32 op,void * vrule,struct audit_context * actx)3262 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3263 			     struct audit_context *actx)
3264 {
3265 	struct context *ctxt;
3266 	struct mls_level *level;
3267 	struct selinux_audit_rule *rule = vrule;
3268 	int match = 0;
3269 
3270 	if (unlikely(!rule)) {
3271 		WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3272 		return -ENOENT;
3273 	}
3274 
3275 	read_lock(&policy_rwlock);
3276 
3277 	if (rule->au_seqno < latest_granting) {
3278 		match = -ESTALE;
3279 		goto out;
3280 	}
3281 
3282 	ctxt = sidtab_search(&sidtab, sid);
3283 	if (unlikely(!ctxt)) {
3284 		WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3285 			  sid);
3286 		match = -ENOENT;
3287 		goto out;
3288 	}
3289 
3290 	/* a field/op pair that is not caught here will simply fall through
3291 	   without a match */
3292 	switch (field) {
3293 	case AUDIT_SUBJ_USER:
3294 	case AUDIT_OBJ_USER:
3295 		switch (op) {
3296 		case Audit_equal:
3297 			match = (ctxt->user == rule->au_ctxt.user);
3298 			break;
3299 		case Audit_not_equal:
3300 			match = (ctxt->user != rule->au_ctxt.user);
3301 			break;
3302 		}
3303 		break;
3304 	case AUDIT_SUBJ_ROLE:
3305 	case AUDIT_OBJ_ROLE:
3306 		switch (op) {
3307 		case Audit_equal:
3308 			match = (ctxt->role == rule->au_ctxt.role);
3309 			break;
3310 		case Audit_not_equal:
3311 			match = (ctxt->role != rule->au_ctxt.role);
3312 			break;
3313 		}
3314 		break;
3315 	case AUDIT_SUBJ_TYPE:
3316 	case AUDIT_OBJ_TYPE:
3317 		switch (op) {
3318 		case Audit_equal:
3319 			match = (ctxt->type == rule->au_ctxt.type);
3320 			break;
3321 		case Audit_not_equal:
3322 			match = (ctxt->type != rule->au_ctxt.type);
3323 			break;
3324 		}
3325 		break;
3326 	case AUDIT_SUBJ_SEN:
3327 	case AUDIT_SUBJ_CLR:
3328 	case AUDIT_OBJ_LEV_LOW:
3329 	case AUDIT_OBJ_LEV_HIGH:
3330 		level = ((field == AUDIT_SUBJ_SEN ||
3331 			  field == AUDIT_OBJ_LEV_LOW) ?
3332 			 &ctxt->range.level[0] : &ctxt->range.level[1]);
3333 		switch (op) {
3334 		case Audit_equal:
3335 			match = mls_level_eq(&rule->au_ctxt.range.level[0],
3336 					     level);
3337 			break;
3338 		case Audit_not_equal:
3339 			match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3340 					      level);
3341 			break;
3342 		case Audit_lt:
3343 			match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3344 					       level) &&
3345 				 !mls_level_eq(&rule->au_ctxt.range.level[0],
3346 					       level));
3347 			break;
3348 		case Audit_le:
3349 			match = mls_level_dom(&rule->au_ctxt.range.level[0],
3350 					      level);
3351 			break;
3352 		case Audit_gt:
3353 			match = (mls_level_dom(level,
3354 					      &rule->au_ctxt.range.level[0]) &&
3355 				 !mls_level_eq(level,
3356 					       &rule->au_ctxt.range.level[0]));
3357 			break;
3358 		case Audit_ge:
3359 			match = mls_level_dom(level,
3360 					      &rule->au_ctxt.range.level[0]);
3361 			break;
3362 		}
3363 	}
3364 
3365 out:
3366 	read_unlock(&policy_rwlock);
3367 	return match;
3368 }
3369 
3370 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3371 
aurule_avc_callback(u32 event)3372 static int aurule_avc_callback(u32 event)
3373 {
3374 	int err = 0;
3375 
3376 	if (event == AVC_CALLBACK_RESET && aurule_callback)
3377 		err = aurule_callback();
3378 	return err;
3379 }
3380 
aurule_init(void)3381 static int __init aurule_init(void)
3382 {
3383 	int err;
3384 
3385 	err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3386 	if (err)
3387 		panic("avc_add_callback() failed, error %d\n", err);
3388 
3389 	return err;
3390 }
3391 __initcall(aurule_init);
3392 
3393 #ifdef CONFIG_NETLABEL
3394 /**
3395  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3396  * @secattr: the NetLabel packet security attributes
3397  * @sid: the SELinux SID
3398  *
3399  * Description:
3400  * Attempt to cache the context in @ctx, which was derived from the packet in
3401  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3402  * already been initialized.
3403  *
3404  */
security_netlbl_cache_add(struct netlbl_lsm_secattr * secattr,u32 sid)3405 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3406 				      u32 sid)
3407 {
3408 	u32 *sid_cache;
3409 
3410 	sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3411 	if (sid_cache == NULL)
3412 		return;
3413 	secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3414 	if (secattr->cache == NULL) {
3415 		kfree(sid_cache);
3416 		return;
3417 	}
3418 
3419 	*sid_cache = sid;
3420 	secattr->cache->free = kfree;
3421 	secattr->cache->data = sid_cache;
3422 	secattr->flags |= NETLBL_SECATTR_CACHE;
3423 }
3424 
3425 /**
3426  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3427  * @secattr: the NetLabel packet security attributes
3428  * @sid: the SELinux SID
3429  *
3430  * Description:
3431  * Convert the given NetLabel security attributes in @secattr into a
3432  * SELinux SID.  If the @secattr field does not contain a full SELinux
3433  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3434  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3435  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3436  * conversion for future lookups.  Returns zero on success, negative values on
3437  * failure.
3438  *
3439  */
security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr * secattr,u32 * sid)3440 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3441 				   u32 *sid)
3442 {
3443 	int rc;
3444 	struct context *ctx;
3445 	struct context ctx_new;
3446 
3447 	if (!ss_initialized) {
3448 		*sid = SECSID_NULL;
3449 		return 0;
3450 	}
3451 
3452 	read_lock(&policy_rwlock);
3453 
3454 	if (secattr->flags & NETLBL_SECATTR_CACHE)
3455 		*sid = *(u32 *)secattr->cache->data;
3456 	else if (secattr->flags & NETLBL_SECATTR_SECID)
3457 		*sid = secattr->attr.secid;
3458 	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3459 		rc = -EIDRM;
3460 		ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3461 		if (ctx == NULL)
3462 			goto out;
3463 
3464 		context_init(&ctx_new);
3465 		ctx_new.user = ctx->user;
3466 		ctx_new.role = ctx->role;
3467 		ctx_new.type = ctx->type;
3468 		mls_import_netlbl_lvl(&ctx_new, secattr);
3469 		if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3470 			rc = mls_import_netlbl_cat(&ctx_new, secattr);
3471 			if (rc)
3472 				goto out;
3473 		}
3474 		rc = -EIDRM;
3475 		if (!mls_context_isvalid(&policydb, &ctx_new))
3476 			goto out_free;
3477 
3478 		rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3479 		if (rc)
3480 			goto out_free;
3481 
3482 		security_netlbl_cache_add(secattr, *sid);
3483 
3484 		ebitmap_destroy(&ctx_new.range.level[0].cat);
3485 	} else
3486 		*sid = SECSID_NULL;
3487 
3488 	read_unlock(&policy_rwlock);
3489 	return 0;
3490 out_free:
3491 	ebitmap_destroy(&ctx_new.range.level[0].cat);
3492 out:
3493 	read_unlock(&policy_rwlock);
3494 	return rc;
3495 }
3496 
3497 /**
3498  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3499  * @sid: the SELinux SID
3500  * @secattr: the NetLabel packet security attributes
3501  *
3502  * Description:
3503  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3504  * Returns zero on success, negative values on failure.
3505  *
3506  */
security_netlbl_sid_to_secattr(u32 sid,struct netlbl_lsm_secattr * secattr)3507 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3508 {
3509 	int rc;
3510 	struct context *ctx;
3511 
3512 	if (!ss_initialized)
3513 		return 0;
3514 
3515 	read_lock(&policy_rwlock);
3516 
3517 	rc = -ENOENT;
3518 	ctx = sidtab_search(&sidtab, sid);
3519 	if (ctx == NULL)
3520 		goto out;
3521 
3522 	rc = -ENOMEM;
3523 	secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3524 				  GFP_ATOMIC);
3525 	if (secattr->domain == NULL)
3526 		goto out;
3527 
3528 	secattr->attr.secid = sid;
3529 	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3530 	mls_export_netlbl_lvl(ctx, secattr);
3531 	rc = mls_export_netlbl_cat(ctx, secattr);
3532 out:
3533 	read_unlock(&policy_rwlock);
3534 	return rc;
3535 }
3536 #endif /* CONFIG_NETLABEL */
3537 
3538 /**
3539  * security_read_policy - read the policy.
3540  * @data: binary policy data
3541  * @len: length of data in bytes
3542  *
3543  */
security_read_policy(void ** data,size_t * len)3544 int security_read_policy(void **data, size_t *len)
3545 {
3546 	int rc;
3547 	struct policy_file fp;
3548 
3549 	if (!ss_initialized)
3550 		return -EINVAL;
3551 
3552 	*len = security_policydb_len();
3553 
3554 	*data = vmalloc_user(*len);
3555 	if (!*data)
3556 		return -ENOMEM;
3557 
3558 	fp.data = *data;
3559 	fp.len = *len;
3560 
3561 	read_lock(&policy_rwlock);
3562 	rc = policydb_write(&policydb, &fp);
3563 	read_unlock(&policy_rwlock);
3564 
3565 	if (rc)
3566 		return rc;
3567 
3568 	*len = (unsigned long)fp.data - (unsigned long)*data;
3569 	return 0;
3570 
3571 }
3572