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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Implementation of the security services.
4 *
5 * Authors : Stephen Smalley, <stephen.smalley.work@gmail.com>
6 * James Morris <jmorris@redhat.com>
7 *
8 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
9 *
10 * Support for enhanced MLS infrastructure.
11 * Support for context based audit filters.
12 *
13 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
14 *
15 * Added conditional policy language extensions
16 *
17 * Updated: Hewlett-Packard <paul@paul-moore.com>
18 *
19 * Added support for NetLabel
20 * Added support for the policy capability bitmap
21 *
22 * Updated: Chad Sellers <csellers@tresys.com>
23 *
24 * Added validation of kernel classes and permissions
25 *
26 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
27 *
28 * Added support for bounds domain and audit messaged on masked permissions
29 *
30 * Updated: Guido Trentalancia <guido@trentalancia.com>
31 *
32 * Added support for runtime switching of the policy type
33 *
34 * Copyright (C) 2008, 2009 NEC Corporation
35 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
36 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
37 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
38 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
39 */
40#include <linux/kernel.h>
41#include <linux/slab.h>
42#include <linux/string.h>
43#include <linux/spinlock.h>
44#include <linux/rcupdate.h>
45#include <linux/errno.h>
46#include <linux/in.h>
47#include <linux/sched.h>
48#include <linux/audit.h>
49#include <linux/vmalloc.h>
50#include <linux/lsm_hooks.h>
51#include <net/netlabel.h>
52
53#include "flask.h"
54#include "avc.h"
55#include "avc_ss.h"
56#include "security.h"
57#include "context.h"
58#include "policydb.h"
59#include "sidtab.h"
60#include "services.h"
61#include "conditional.h"
62#include "mls.h"
63#include "objsec.h"
64#include "netlabel.h"
65#include "xfrm.h"
66#include "ebitmap.h"
67#include "audit.h"
68#include "policycap_names.h"
69#include "ima.h"
70
71struct selinux_policy_convert_data {
72 struct convert_context_args args;
73 struct sidtab_convert_params sidtab_params;
74};
75
76/* Forward declaration. */
77static int context_struct_to_string(struct policydb *policydb,
78 struct context *context,
79 char **scontext,
80 u32 *scontext_len);
81
82static int sidtab_entry_to_string(struct policydb *policydb,
83 struct sidtab *sidtab,
84 struct sidtab_entry *entry,
85 char **scontext,
86 u32 *scontext_len);
87
88static void context_struct_compute_av(struct policydb *policydb,
89 struct context *scontext,
90 struct context *tcontext,
91 u16 tclass,
92 struct av_decision *avd,
93 struct extended_perms *xperms);
94
95static int selinux_set_mapping(struct policydb *pol,
96 const struct security_class_mapping *map,
97 struct selinux_map *out_map)
98{
99 u16 i, j;
100 bool print_unknown_handle = false;
101
102 /* Find number of classes in the input mapping */
103 if (!map)
104 return -EINVAL;
105 i = 0;
106 while (map[i].name)
107 i++;
108
109 /* Allocate space for the class records, plus one for class zero */
110 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
111 if (!out_map->mapping)
112 return -ENOMEM;
113
114 /* Store the raw class and permission values */
115 j = 0;
116 while (map[j].name) {
117 const struct security_class_mapping *p_in = map + (j++);
118 struct selinux_mapping *p_out = out_map->mapping + j;
119 u16 k;
120
121 /* An empty class string skips ahead */
122 if (!strcmp(p_in->name, "")) {
123 p_out->num_perms = 0;
124 continue;
125 }
126
127 p_out->value = string_to_security_class(pol, p_in->name);
128 if (!p_out->value) {
129 pr_info("SELinux: Class %s not defined in policy.\n",
130 p_in->name);
131 if (pol->reject_unknown)
132 goto err;
133 p_out->num_perms = 0;
134 print_unknown_handle = true;
135 continue;
136 }
137
138 k = 0;
139 while (p_in->perms[k]) {
140 /* An empty permission string skips ahead */
141 if (!*p_in->perms[k]) {
142 k++;
143 continue;
144 }
145 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
146 p_in->perms[k]);
147 if (!p_out->perms[k]) {
148 pr_info("SELinux: Permission %s in class %s not defined in policy.\n",
149 p_in->perms[k], p_in->name);
150 if (pol->reject_unknown)
151 goto err;
152 print_unknown_handle = true;
153 }
154
155 k++;
156 }
157 p_out->num_perms = k;
158 }
159
160 if (print_unknown_handle)
161 pr_info("SELinux: the above unknown classes and permissions will be %s\n",
162 pol->allow_unknown ? "allowed" : "denied");
163
164 out_map->size = i;
165 return 0;
166err:
167 kfree(out_map->mapping);
168 out_map->mapping = NULL;
169 return -EINVAL;
170}
171
172/*
173 * Get real, policy values from mapped values
174 */
175
176static u16 unmap_class(struct selinux_map *map, u16 tclass)
177{
178 if (tclass < map->size)
179 return map->mapping[tclass].value;
180
181 return tclass;
182}
183
184/*
185 * Get kernel value for class from its policy value
186 */
187static u16 map_class(struct selinux_map *map, u16 pol_value)
188{
189 u16 i;
190
191 for (i = 1; i < map->size; i++) {
192 if (map->mapping[i].value == pol_value)
193 return i;
194 }
195
196 return SECCLASS_NULL;
197}
198
199static void map_decision(struct selinux_map *map,
200 u16 tclass, struct av_decision *avd,
201 int allow_unknown)
202{
203 if (tclass < map->size) {
204 struct selinux_mapping *mapping = &map->mapping[tclass];
205 unsigned int i, n = mapping->num_perms;
206 u32 result;
207
208 for (i = 0, result = 0; i < n; i++) {
209 if (avd->allowed & mapping->perms[i])
210 result |= (u32)1<<i;
211 if (allow_unknown && !mapping->perms[i])
212 result |= (u32)1<<i;
213 }
214 avd->allowed = result;
215
216 for (i = 0, result = 0; i < n; i++)
217 if (avd->auditallow & mapping->perms[i])
218 result |= (u32)1<<i;
219 avd->auditallow = result;
220
221 for (i = 0, result = 0; i < n; i++) {
222 if (avd->auditdeny & mapping->perms[i])
223 result |= (u32)1<<i;
224 if (!allow_unknown && !mapping->perms[i])
225 result |= (u32)1<<i;
226 }
227 /*
228 * In case the kernel has a bug and requests a permission
229 * between num_perms and the maximum permission number, we
230 * should audit that denial
231 */
232 for (; i < (sizeof(u32)*8); i++)
233 result |= (u32)1<<i;
234 avd->auditdeny = result;
235 }
236}
237
238int security_mls_enabled(void)
239{
240 int mls_enabled;
241 struct selinux_policy *policy;
242
243 if (!selinux_initialized())
244 return 0;
245
246 rcu_read_lock();
247 policy = rcu_dereference(selinux_state.policy);
248 mls_enabled = policy->policydb.mls_enabled;
249 rcu_read_unlock();
250 return mls_enabled;
251}
252
253/*
254 * Return the boolean value of a constraint expression
255 * when it is applied to the specified source and target
256 * security contexts.
257 *
258 * xcontext is a special beast... It is used by the validatetrans rules
259 * only. For these rules, scontext is the context before the transition,
260 * tcontext is the context after the transition, and xcontext is the context
261 * of the process performing the transition. All other callers of
262 * constraint_expr_eval should pass in NULL for xcontext.
263 */
264static int constraint_expr_eval(struct policydb *policydb,
265 struct context *scontext,
266 struct context *tcontext,
267 struct context *xcontext,
268 struct constraint_expr *cexpr)
269{
270 u32 val1, val2;
271 struct context *c;
272 struct role_datum *r1, *r2;
273 struct mls_level *l1, *l2;
274 struct constraint_expr *e;
275 int s[CEXPR_MAXDEPTH];
276 int sp = -1;
277
278 for (e = cexpr; e; e = e->next) {
279 switch (e->expr_type) {
280 case CEXPR_NOT:
281 BUG_ON(sp < 0);
282 s[sp] = !s[sp];
283 break;
284 case CEXPR_AND:
285 BUG_ON(sp < 1);
286 sp--;
287 s[sp] &= s[sp + 1];
288 break;
289 case CEXPR_OR:
290 BUG_ON(sp < 1);
291 sp--;
292 s[sp] |= s[sp + 1];
293 break;
294 case CEXPR_ATTR:
295 if (sp == (CEXPR_MAXDEPTH - 1))
296 return 0;
297 switch (e->attr) {
298 case CEXPR_USER:
299 val1 = scontext->user;
300 val2 = tcontext->user;
301 break;
302 case CEXPR_TYPE:
303 val1 = scontext->type;
304 val2 = tcontext->type;
305 break;
306 case CEXPR_ROLE:
307 val1 = scontext->role;
308 val2 = tcontext->role;
309 r1 = policydb->role_val_to_struct[val1 - 1];
310 r2 = policydb->role_val_to_struct[val2 - 1];
311 switch (e->op) {
312 case CEXPR_DOM:
313 s[++sp] = ebitmap_get_bit(&r1->dominates,
314 val2 - 1);
315 continue;
316 case CEXPR_DOMBY:
317 s[++sp] = ebitmap_get_bit(&r2->dominates,
318 val1 - 1);
319 continue;
320 case CEXPR_INCOMP:
321 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
322 val2 - 1) &&
323 !ebitmap_get_bit(&r2->dominates,
324 val1 - 1));
325 continue;
326 default:
327 break;
328 }
329 break;
330 case CEXPR_L1L2:
331 l1 = &(scontext->range.level[0]);
332 l2 = &(tcontext->range.level[0]);
333 goto mls_ops;
334 case CEXPR_L1H2:
335 l1 = &(scontext->range.level[0]);
336 l2 = &(tcontext->range.level[1]);
337 goto mls_ops;
338 case CEXPR_H1L2:
339 l1 = &(scontext->range.level[1]);
340 l2 = &(tcontext->range.level[0]);
341 goto mls_ops;
342 case CEXPR_H1H2:
343 l1 = &(scontext->range.level[1]);
344 l2 = &(tcontext->range.level[1]);
345 goto mls_ops;
346 case CEXPR_L1H1:
347 l1 = &(scontext->range.level[0]);
348 l2 = &(scontext->range.level[1]);
349 goto mls_ops;
350 case CEXPR_L2H2:
351 l1 = &(tcontext->range.level[0]);
352 l2 = &(tcontext->range.level[1]);
353 goto mls_ops;
354mls_ops:
355 switch (e->op) {
356 case CEXPR_EQ:
357 s[++sp] = mls_level_eq(l1, l2);
358 continue;
359 case CEXPR_NEQ:
360 s[++sp] = !mls_level_eq(l1, l2);
361 continue;
362 case CEXPR_DOM:
363 s[++sp] = mls_level_dom(l1, l2);
364 continue;
365 case CEXPR_DOMBY:
366 s[++sp] = mls_level_dom(l2, l1);
367 continue;
368 case CEXPR_INCOMP:
369 s[++sp] = mls_level_incomp(l2, l1);
370 continue;
371 default:
372 BUG();
373 return 0;
374 }
375 break;
376 default:
377 BUG();
378 return 0;
379 }
380
381 switch (e->op) {
382 case CEXPR_EQ:
383 s[++sp] = (val1 == val2);
384 break;
385 case CEXPR_NEQ:
386 s[++sp] = (val1 != val2);
387 break;
388 default:
389 BUG();
390 return 0;
391 }
392 break;
393 case CEXPR_NAMES:
394 if (sp == (CEXPR_MAXDEPTH-1))
395 return 0;
396 c = scontext;
397 if (e->attr & CEXPR_TARGET)
398 c = tcontext;
399 else if (e->attr & CEXPR_XTARGET) {
400 c = xcontext;
401 if (!c) {
402 BUG();
403 return 0;
404 }
405 }
406 if (e->attr & CEXPR_USER)
407 val1 = c->user;
408 else if (e->attr & CEXPR_ROLE)
409 val1 = c->role;
410 else if (e->attr & CEXPR_TYPE)
411 val1 = c->type;
412 else {
413 BUG();
414 return 0;
415 }
416
417 switch (e->op) {
418 case CEXPR_EQ:
419 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
420 break;
421 case CEXPR_NEQ:
422 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
423 break;
424 default:
425 BUG();
426 return 0;
427 }
428 break;
429 default:
430 BUG();
431 return 0;
432 }
433 }
434
435 BUG_ON(sp != 0);
436 return s[0];
437}
438
439/*
440 * security_dump_masked_av - dumps masked permissions during
441 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
442 */
443static int dump_masked_av_helper(void *k, void *d, void *args)
444{
445 struct perm_datum *pdatum = d;
446 char **permission_names = args;
447
448 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
449
450 permission_names[pdatum->value - 1] = (char *)k;
451
452 return 0;
453}
454
455static void security_dump_masked_av(struct policydb *policydb,
456 struct context *scontext,
457 struct context *tcontext,
458 u16 tclass,
459 u32 permissions,
460 const char *reason)
461{
462 struct common_datum *common_dat;
463 struct class_datum *tclass_dat;
464 struct audit_buffer *ab;
465 char *tclass_name;
466 char *scontext_name = NULL;
467 char *tcontext_name = NULL;
468 char *permission_names[32];
469 int index;
470 u32 length;
471 bool need_comma = false;
472
473 if (!permissions)
474 return;
475
476 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
477 tclass_dat = policydb->class_val_to_struct[tclass - 1];
478 common_dat = tclass_dat->comdatum;
479
480 /* init permission_names */
481 if (common_dat &&
482 hashtab_map(&common_dat->permissions.table,
483 dump_masked_av_helper, permission_names) < 0)
484 goto out;
485
486 if (hashtab_map(&tclass_dat->permissions.table,
487 dump_masked_av_helper, permission_names) < 0)
488 goto out;
489
490 /* get scontext/tcontext in text form */
491 if (context_struct_to_string(policydb, scontext,
492 &scontext_name, &length) < 0)
493 goto out;
494
495 if (context_struct_to_string(policydb, tcontext,
496 &tcontext_name, &length) < 0)
497 goto out;
498
499 /* audit a message */
500 ab = audit_log_start(audit_context(),
501 GFP_ATOMIC, AUDIT_SELINUX_ERR);
502 if (!ab)
503 goto out;
504
505 audit_log_format(ab, "op=security_compute_av reason=%s "
506 "scontext=%s tcontext=%s tclass=%s perms=",
507 reason, scontext_name, tcontext_name, tclass_name);
508
509 for (index = 0; index < 32; index++) {
510 u32 mask = (1 << index);
511
512 if ((mask & permissions) == 0)
513 continue;
514
515 audit_log_format(ab, "%s%s",
516 need_comma ? "," : "",
517 permission_names[index]
518 ? permission_names[index] : "????");
519 need_comma = true;
520 }
521 audit_log_end(ab);
522out:
523 /* release scontext/tcontext */
524 kfree(tcontext_name);
525 kfree(scontext_name);
526}
527
528/*
529 * security_boundary_permission - drops violated permissions
530 * on boundary constraint.
531 */
532static void type_attribute_bounds_av(struct policydb *policydb,
533 struct context *scontext,
534 struct context *tcontext,
535 u16 tclass,
536 struct av_decision *avd)
537{
538 struct context lo_scontext;
539 struct context lo_tcontext, *tcontextp = tcontext;
540 struct av_decision lo_avd;
541 struct type_datum *source;
542 struct type_datum *target;
543 u32 masked = 0;
544
545 source = policydb->type_val_to_struct[scontext->type - 1];
546 BUG_ON(!source);
547
548 if (!source->bounds)
549 return;
550
551 target = policydb->type_val_to_struct[tcontext->type - 1];
552 BUG_ON(!target);
553
554 memset(&lo_avd, 0, sizeof(lo_avd));
555
556 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
557 lo_scontext.type = source->bounds;
558
559 if (target->bounds) {
560 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
561 lo_tcontext.type = target->bounds;
562 tcontextp = &lo_tcontext;
563 }
564
565 context_struct_compute_av(policydb, &lo_scontext,
566 tcontextp,
567 tclass,
568 &lo_avd,
569 NULL);
570
571 masked = ~lo_avd.allowed & avd->allowed;
572
573 if (likely(!masked))
574 return; /* no masked permission */
575
576 /* mask violated permissions */
577 avd->allowed &= ~masked;
578
579 /* audit masked permissions */
580 security_dump_masked_av(policydb, scontext, tcontext,
581 tclass, masked, "bounds");
582}
583
584/*
585 * Flag which drivers have permissions and which base permissions are covered.
586 */
587void services_compute_xperms_drivers(
588 struct extended_perms *xperms,
589 struct avtab_node *node)
590{
591 unsigned int i;
592
593 switch (node->datum.u.xperms->specified) {
594 case AVTAB_XPERMS_IOCTLDRIVER:
595 xperms->base_perms |= AVC_EXT_IOCTL;
596 /* if one or more driver has all permissions allowed */
597 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
598 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
599 break;
600 case AVTAB_XPERMS_IOCTLFUNCTION:
601 xperms->base_perms |= AVC_EXT_IOCTL;
602 /* if allowing permissions within a driver */
603 security_xperm_set(xperms->drivers.p,
604 node->datum.u.xperms->driver);
605 break;
606 case AVTAB_XPERMS_NLMSG:
607 xperms->base_perms |= AVC_EXT_NLMSG;
608 /* if allowing permissions within a driver */
609 security_xperm_set(xperms->drivers.p,
610 node->datum.u.xperms->driver);
611 break;
612 }
613
614 xperms->len = 1;
615}
616
617/*
618 * Compute access vectors and extended permissions based on a context
619 * structure pair for the permissions in a particular class.
620 */
621static void context_struct_compute_av(struct policydb *policydb,
622 struct context *scontext,
623 struct context *tcontext,
624 u16 tclass,
625 struct av_decision *avd,
626 struct extended_perms *xperms)
627{
628 struct constraint_node *constraint;
629 struct role_allow *ra;
630 struct avtab_key avkey;
631 struct avtab_node *node;
632 struct class_datum *tclass_datum;
633 struct ebitmap *sattr, *tattr;
634 struct ebitmap_node *snode, *tnode;
635 unsigned int i, j;
636
637 avd->allowed = 0;
638 avd->auditallow = 0;
639 avd->auditdeny = 0xffffffff;
640 if (xperms) {
641 memset(xperms, 0, sizeof(*xperms));
642 }
643
644 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
645 pr_warn_ratelimited("SELinux: Invalid class %u\n", tclass);
646 return;
647 }
648
649 tclass_datum = policydb->class_val_to_struct[tclass - 1];
650
651 /*
652 * If a specific type enforcement rule was defined for
653 * this permission check, then use it.
654 */
655 avkey.target_class = tclass;
656 avkey.specified = AVTAB_AV | AVTAB_XPERMS;
657 sattr = &policydb->type_attr_map_array[scontext->type - 1];
658 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
659 ebitmap_for_each_positive_bit(sattr, snode, i) {
660 ebitmap_for_each_positive_bit(tattr, tnode, j) {
661 avkey.source_type = i + 1;
662 avkey.target_type = j + 1;
663 for (node = avtab_search_node(&policydb->te_avtab,
664 &avkey);
665 node;
666 node = avtab_search_node_next(node, avkey.specified)) {
667 if (node->key.specified == AVTAB_ALLOWED)
668 avd->allowed |= node->datum.u.data;
669 else if (node->key.specified == AVTAB_AUDITALLOW)
670 avd->auditallow |= node->datum.u.data;
671 else if (node->key.specified == AVTAB_AUDITDENY)
672 avd->auditdeny &= node->datum.u.data;
673 else if (xperms && (node->key.specified & AVTAB_XPERMS))
674 services_compute_xperms_drivers(xperms, node);
675 }
676
677 /* Check conditional av table for additional permissions */
678 cond_compute_av(&policydb->te_cond_avtab, &avkey,
679 avd, xperms);
680
681 }
682 }
683
684 /*
685 * Remove any permissions prohibited by a constraint (this includes
686 * the MLS policy).
687 */
688 constraint = tclass_datum->constraints;
689 while (constraint) {
690 if ((constraint->permissions & (avd->allowed)) &&
691 !constraint_expr_eval(policydb, scontext, tcontext, NULL,
692 constraint->expr)) {
693 avd->allowed &= ~(constraint->permissions);
694 }
695 constraint = constraint->next;
696 }
697
698 /*
699 * If checking process transition permission and the
700 * role is changing, then check the (current_role, new_role)
701 * pair.
702 */
703 if (tclass == policydb->process_class &&
704 (avd->allowed & policydb->process_trans_perms) &&
705 scontext->role != tcontext->role) {
706 for (ra = policydb->role_allow; ra; ra = ra->next) {
707 if (scontext->role == ra->role &&
708 tcontext->role == ra->new_role)
709 break;
710 }
711 if (!ra)
712 avd->allowed &= ~policydb->process_trans_perms;
713 }
714
715 /*
716 * If the given source and target types have boundary
717 * constraint, lazy checks have to mask any violated
718 * permission and notice it to userspace via audit.
719 */
720 type_attribute_bounds_av(policydb, scontext, tcontext,
721 tclass, avd);
722}
723
724static int security_validtrans_handle_fail(struct selinux_policy *policy,
725 struct sidtab_entry *oentry,
726 struct sidtab_entry *nentry,
727 struct sidtab_entry *tentry,
728 u16 tclass)
729{
730 struct policydb *p = &policy->policydb;
731 struct sidtab *sidtab = policy->sidtab;
732 char *o = NULL, *n = NULL, *t = NULL;
733 u32 olen, nlen, tlen;
734
735 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
736 goto out;
737 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
738 goto out;
739 if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
740 goto out;
741 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
742 "op=security_validate_transition seresult=denied"
743 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
744 o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
745out:
746 kfree(o);
747 kfree(n);
748 kfree(t);
749
750 if (!enforcing_enabled())
751 return 0;
752 return -EPERM;
753}
754
755static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
756 u16 orig_tclass, bool user)
757{
758 struct selinux_policy *policy;
759 struct policydb *policydb;
760 struct sidtab *sidtab;
761 struct sidtab_entry *oentry;
762 struct sidtab_entry *nentry;
763 struct sidtab_entry *tentry;
764 struct class_datum *tclass_datum;
765 struct constraint_node *constraint;
766 u16 tclass;
767 int rc = 0;
768
769
770 if (!selinux_initialized())
771 return 0;
772
773 rcu_read_lock();
774
775 policy = rcu_dereference(selinux_state.policy);
776 policydb = &policy->policydb;
777 sidtab = policy->sidtab;
778
779 if (!user)
780 tclass = unmap_class(&policy->map, orig_tclass);
781 else
782 tclass = orig_tclass;
783
784 if (!tclass || tclass > policydb->p_classes.nprim) {
785 rc = -EINVAL;
786 goto out;
787 }
788 tclass_datum = policydb->class_val_to_struct[tclass - 1];
789
790 oentry = sidtab_search_entry(sidtab, oldsid);
791 if (!oentry) {
792 pr_err("SELinux: %s: unrecognized SID %d\n",
793 __func__, oldsid);
794 rc = -EINVAL;
795 goto out;
796 }
797
798 nentry = sidtab_search_entry(sidtab, newsid);
799 if (!nentry) {
800 pr_err("SELinux: %s: unrecognized SID %d\n",
801 __func__, newsid);
802 rc = -EINVAL;
803 goto out;
804 }
805
806 tentry = sidtab_search_entry(sidtab, tasksid);
807 if (!tentry) {
808 pr_err("SELinux: %s: unrecognized SID %d\n",
809 __func__, tasksid);
810 rc = -EINVAL;
811 goto out;
812 }
813
814 constraint = tclass_datum->validatetrans;
815 while (constraint) {
816 if (!constraint_expr_eval(policydb, &oentry->context,
817 &nentry->context, &tentry->context,
818 constraint->expr)) {
819 if (user)
820 rc = -EPERM;
821 else
822 rc = security_validtrans_handle_fail(policy,
823 oentry,
824 nentry,
825 tentry,
826 tclass);
827 goto out;
828 }
829 constraint = constraint->next;
830 }
831
832out:
833 rcu_read_unlock();
834 return rc;
835}
836
837int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
838 u16 tclass)
839{
840 return security_compute_validatetrans(oldsid, newsid, tasksid,
841 tclass, true);
842}
843
844int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
845 u16 orig_tclass)
846{
847 return security_compute_validatetrans(oldsid, newsid, tasksid,
848 orig_tclass, false);
849}
850
851/*
852 * security_bounded_transition - check whether the given
853 * transition is directed to bounded, or not.
854 * It returns 0, if @newsid is bounded by @oldsid.
855 * Otherwise, it returns error code.
856 *
857 * @oldsid : current security identifier
858 * @newsid : destinated security identifier
859 */
860int security_bounded_transition(u32 old_sid, u32 new_sid)
861{
862 struct selinux_policy *policy;
863 struct policydb *policydb;
864 struct sidtab *sidtab;
865 struct sidtab_entry *old_entry, *new_entry;
866 struct type_datum *type;
867 u32 index;
868 int rc;
869
870 if (!selinux_initialized())
871 return 0;
872
873 rcu_read_lock();
874 policy = rcu_dereference(selinux_state.policy);
875 policydb = &policy->policydb;
876 sidtab = policy->sidtab;
877
878 rc = -EINVAL;
879 old_entry = sidtab_search_entry(sidtab, old_sid);
880 if (!old_entry) {
881 pr_err("SELinux: %s: unrecognized SID %u\n",
882 __func__, old_sid);
883 goto out;
884 }
885
886 rc = -EINVAL;
887 new_entry = sidtab_search_entry(sidtab, new_sid);
888 if (!new_entry) {
889 pr_err("SELinux: %s: unrecognized SID %u\n",
890 __func__, new_sid);
891 goto out;
892 }
893
894 rc = 0;
895 /* type/domain unchanged */
896 if (old_entry->context.type == new_entry->context.type)
897 goto out;
898
899 index = new_entry->context.type;
900 while (true) {
901 type = policydb->type_val_to_struct[index - 1];
902 BUG_ON(!type);
903
904 /* not bounded anymore */
905 rc = -EPERM;
906 if (!type->bounds)
907 break;
908
909 /* @newsid is bounded by @oldsid */
910 rc = 0;
911 if (type->bounds == old_entry->context.type)
912 break;
913
914 index = type->bounds;
915 }
916
917 if (rc) {
918 char *old_name = NULL;
919 char *new_name = NULL;
920 u32 length;
921
922 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
923 &old_name, &length) &&
924 !sidtab_entry_to_string(policydb, sidtab, new_entry,
925 &new_name, &length)) {
926 audit_log(audit_context(),
927 GFP_ATOMIC, AUDIT_SELINUX_ERR,
928 "op=security_bounded_transition "
929 "seresult=denied "
930 "oldcontext=%s newcontext=%s",
931 old_name, new_name);
932 }
933 kfree(new_name);
934 kfree(old_name);
935 }
936out:
937 rcu_read_unlock();
938
939 return rc;
940}
941
942static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
943{
944 avd->allowed = 0;
945 avd->auditallow = 0;
946 avd->auditdeny = 0xffffffff;
947 if (policy)
948 avd->seqno = policy->latest_granting;
949 else
950 avd->seqno = 0;
951 avd->flags = 0;
952}
953
954static void update_xperms_extended_data(u8 specified,
955 struct extended_perms_data *from,
956 struct extended_perms_data *xp_data)
957{
958 unsigned int i;
959
960 switch (specified) {
961 case AVTAB_XPERMS_IOCTLDRIVER:
962 memset(xp_data->p, 0xff, sizeof(xp_data->p));
963 break;
964 case AVTAB_XPERMS_IOCTLFUNCTION:
965 case AVTAB_XPERMS_NLMSG:
966 for (i = 0; i < ARRAY_SIZE(xp_data->p); i++)
967 xp_data->p[i] |= from->p[i];
968 break;
969 }
970
971}
972
973void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
974 struct avtab_node *node)
975{
976 switch (node->datum.u.xperms->specified) {
977 case AVTAB_XPERMS_IOCTLFUNCTION:
978 if (xpermd->base_perm != AVC_EXT_IOCTL ||
979 xpermd->driver != node->datum.u.xperms->driver)
980 return;
981 break;
982 case AVTAB_XPERMS_IOCTLDRIVER:
983 if (xpermd->base_perm != AVC_EXT_IOCTL ||
984 !security_xperm_test(node->datum.u.xperms->perms.p,
985 xpermd->driver))
986 return;
987 break;
988 case AVTAB_XPERMS_NLMSG:
989 if (xpermd->base_perm != AVC_EXT_NLMSG ||
990 xpermd->driver != node->datum.u.xperms->driver)
991 return;
992 break;
993 default:
994 pr_warn_once(
995 "SELinux: unknown extended permission (%u) will be ignored\n",
996 node->datum.u.xperms->specified);
997 return;
998 }
999
1000 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
1001 xpermd->used |= XPERMS_ALLOWED;
1002 update_xperms_extended_data(node->datum.u.xperms->specified,
1003 &node->datum.u.xperms->perms,
1004 xpermd->allowed);
1005 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
1006 xpermd->used |= XPERMS_AUDITALLOW;
1007 update_xperms_extended_data(node->datum.u.xperms->specified,
1008 &node->datum.u.xperms->perms,
1009 xpermd->auditallow);
1010 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
1011 xpermd->used |= XPERMS_DONTAUDIT;
1012 update_xperms_extended_data(node->datum.u.xperms->specified,
1013 &node->datum.u.xperms->perms,
1014 xpermd->dontaudit);
1015 } else {
1016 pr_warn_once("SELinux: unknown specified key (%u)\n",
1017 node->key.specified);
1018 }
1019}
1020
1021void security_compute_xperms_decision(u32 ssid,
1022 u32 tsid,
1023 u16 orig_tclass,
1024 u8 driver,
1025 u8 base_perm,
1026 struct extended_perms_decision *xpermd)
1027{
1028 struct selinux_policy *policy;
1029 struct policydb *policydb;
1030 struct sidtab *sidtab;
1031 u16 tclass;
1032 struct context *scontext, *tcontext;
1033 struct avtab_key avkey;
1034 struct avtab_node *node;
1035 struct ebitmap *sattr, *tattr;
1036 struct ebitmap_node *snode, *tnode;
1037 unsigned int i, j;
1038
1039 xpermd->base_perm = base_perm;
1040 xpermd->driver = driver;
1041 xpermd->used = 0;
1042 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1043 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1044 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1045
1046 rcu_read_lock();
1047 if (!selinux_initialized())
1048 goto allow;
1049
1050 policy = rcu_dereference(selinux_state.policy);
1051 policydb = &policy->policydb;
1052 sidtab = policy->sidtab;
1053
1054 scontext = sidtab_search(sidtab, ssid);
1055 if (!scontext) {
1056 pr_err("SELinux: %s: unrecognized SID %d\n",
1057 __func__, ssid);
1058 goto out;
1059 }
1060
1061 tcontext = sidtab_search(sidtab, tsid);
1062 if (!tcontext) {
1063 pr_err("SELinux: %s: unrecognized SID %d\n",
1064 __func__, tsid);
1065 goto out;
1066 }
1067
1068 tclass = unmap_class(&policy->map, orig_tclass);
1069 if (unlikely(orig_tclass && !tclass)) {
1070 if (policydb->allow_unknown)
1071 goto allow;
1072 goto out;
1073 }
1074
1075
1076 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1077 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1078 goto out;
1079 }
1080
1081 avkey.target_class = tclass;
1082 avkey.specified = AVTAB_XPERMS;
1083 sattr = &policydb->type_attr_map_array[scontext->type - 1];
1084 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1085 ebitmap_for_each_positive_bit(sattr, snode, i) {
1086 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1087 avkey.source_type = i + 1;
1088 avkey.target_type = j + 1;
1089 for (node = avtab_search_node(&policydb->te_avtab,
1090 &avkey);
1091 node;
1092 node = avtab_search_node_next(node, avkey.specified))
1093 services_compute_xperms_decision(xpermd, node);
1094
1095 cond_compute_xperms(&policydb->te_cond_avtab,
1096 &avkey, xpermd);
1097 }
1098 }
1099out:
1100 rcu_read_unlock();
1101 return;
1102allow:
1103 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1104 goto out;
1105}
1106
1107/**
1108 * security_compute_av - Compute access vector decisions.
1109 * @ssid: source security identifier
1110 * @tsid: target security identifier
1111 * @orig_tclass: target security class
1112 * @avd: access vector decisions
1113 * @xperms: extended permissions
1114 *
1115 * Compute a set of access vector decisions based on the
1116 * SID pair (@ssid, @tsid) for the permissions in @tclass.
1117 */
1118void security_compute_av(u32 ssid,
1119 u32 tsid,
1120 u16 orig_tclass,
1121 struct av_decision *avd,
1122 struct extended_perms *xperms)
1123{
1124 struct selinux_policy *policy;
1125 struct policydb *policydb;
1126 struct sidtab *sidtab;
1127 u16 tclass;
1128 struct context *scontext = NULL, *tcontext = NULL;
1129
1130 rcu_read_lock();
1131 policy = rcu_dereference(selinux_state.policy);
1132 avd_init(policy, avd);
1133 xperms->len = 0;
1134 if (!selinux_initialized())
1135 goto allow;
1136
1137 policydb = &policy->policydb;
1138 sidtab = policy->sidtab;
1139
1140 scontext = sidtab_search(sidtab, ssid);
1141 if (!scontext) {
1142 pr_err("SELinux: %s: unrecognized SID %d\n",
1143 __func__, ssid);
1144 goto out;
1145 }
1146
1147 /* permissive domain? */
1148 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1149 avd->flags |= AVD_FLAGS_PERMISSIVE;
1150
1151 tcontext = sidtab_search(sidtab, tsid);
1152 if (!tcontext) {
1153 pr_err("SELinux: %s: unrecognized SID %d\n",
1154 __func__, tsid);
1155 goto out;
1156 }
1157
1158 tclass = unmap_class(&policy->map, orig_tclass);
1159 if (unlikely(orig_tclass && !tclass)) {
1160 if (policydb->allow_unknown)
1161 goto allow;
1162 goto out;
1163 }
1164 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1165 xperms);
1166 map_decision(&policy->map, orig_tclass, avd,
1167 policydb->allow_unknown);
1168out:
1169 rcu_read_unlock();
1170 return;
1171allow:
1172 avd->allowed = 0xffffffff;
1173 goto out;
1174}
1175
1176void security_compute_av_user(u32 ssid,
1177 u32 tsid,
1178 u16 tclass,
1179 struct av_decision *avd)
1180{
1181 struct selinux_policy *policy;
1182 struct policydb *policydb;
1183 struct sidtab *sidtab;
1184 struct context *scontext = NULL, *tcontext = NULL;
1185
1186 rcu_read_lock();
1187 policy = rcu_dereference(selinux_state.policy);
1188 avd_init(policy, avd);
1189 if (!selinux_initialized())
1190 goto allow;
1191
1192 policydb = &policy->policydb;
1193 sidtab = policy->sidtab;
1194
1195 scontext = sidtab_search(sidtab, ssid);
1196 if (!scontext) {
1197 pr_err("SELinux: %s: unrecognized SID %d\n",
1198 __func__, ssid);
1199 goto out;
1200 }
1201
1202 /* permissive domain? */
1203 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1204 avd->flags |= AVD_FLAGS_PERMISSIVE;
1205
1206 tcontext = sidtab_search(sidtab, tsid);
1207 if (!tcontext) {
1208 pr_err("SELinux: %s: unrecognized SID %d\n",
1209 __func__, tsid);
1210 goto out;
1211 }
1212
1213 if (unlikely(!tclass)) {
1214 if (policydb->allow_unknown)
1215 goto allow;
1216 goto out;
1217 }
1218
1219 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1220 NULL);
1221 out:
1222 rcu_read_unlock();
1223 return;
1224allow:
1225 avd->allowed = 0xffffffff;
1226 goto out;
1227}
1228
1229/*
1230 * Write the security context string representation of
1231 * the context structure `context' into a dynamically
1232 * allocated string of the correct size. Set `*scontext'
1233 * to point to this string and set `*scontext_len' to
1234 * the length of the string.
1235 */
1236static int context_struct_to_string(struct policydb *p,
1237 struct context *context,
1238 char **scontext, u32 *scontext_len)
1239{
1240 char *scontextp;
1241
1242 if (scontext)
1243 *scontext = NULL;
1244 *scontext_len = 0;
1245
1246 if (context->len) {
1247 *scontext_len = context->len;
1248 if (scontext) {
1249 *scontext = kstrdup(context->str, GFP_ATOMIC);
1250 if (!(*scontext))
1251 return -ENOMEM;
1252 }
1253 return 0;
1254 }
1255
1256 /* Compute the size of the context. */
1257 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1258 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1259 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1260 *scontext_len += mls_compute_context_len(p, context);
1261
1262 if (!scontext)
1263 return 0;
1264
1265 /* Allocate space for the context; caller must free this space. */
1266 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1267 if (!scontextp)
1268 return -ENOMEM;
1269 *scontext = scontextp;
1270
1271 /*
1272 * Copy the user name, role name and type name into the context.
1273 */
1274 scontextp += sprintf(scontextp, "%s:%s:%s",
1275 sym_name(p, SYM_USERS, context->user - 1),
1276 sym_name(p, SYM_ROLES, context->role - 1),
1277 sym_name(p, SYM_TYPES, context->type - 1));
1278
1279 mls_sid_to_context(p, context, &scontextp);
1280
1281 *scontextp = 0;
1282
1283 return 0;
1284}
1285
1286static int sidtab_entry_to_string(struct policydb *p,
1287 struct sidtab *sidtab,
1288 struct sidtab_entry *entry,
1289 char **scontext, u32 *scontext_len)
1290{
1291 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1292
1293 if (rc != -ENOENT)
1294 return rc;
1295
1296 rc = context_struct_to_string(p, &entry->context, scontext,
1297 scontext_len);
1298 if (!rc && scontext)
1299 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1300 return rc;
1301}
1302
1303#include "initial_sid_to_string.h"
1304
1305int security_sidtab_hash_stats(char *page)
1306{
1307 struct selinux_policy *policy;
1308 int rc;
1309
1310 if (!selinux_initialized()) {
1311 pr_err("SELinux: %s: called before initial load_policy\n",
1312 __func__);
1313 return -EINVAL;
1314 }
1315
1316 rcu_read_lock();
1317 policy = rcu_dereference(selinux_state.policy);
1318 rc = sidtab_hash_stats(policy->sidtab, page);
1319 rcu_read_unlock();
1320
1321 return rc;
1322}
1323
1324const char *security_get_initial_sid_context(u32 sid)
1325{
1326 if (unlikely(sid > SECINITSID_NUM))
1327 return NULL;
1328 return initial_sid_to_string[sid];
1329}
1330
1331static int security_sid_to_context_core(u32 sid, char **scontext,
1332 u32 *scontext_len, int force,
1333 int only_invalid)
1334{
1335 struct selinux_policy *policy;
1336 struct policydb *policydb;
1337 struct sidtab *sidtab;
1338 struct sidtab_entry *entry;
1339 int rc = 0;
1340
1341 if (scontext)
1342 *scontext = NULL;
1343 *scontext_len = 0;
1344
1345 if (!selinux_initialized()) {
1346 if (sid <= SECINITSID_NUM) {
1347 char *scontextp;
1348 const char *s;
1349
1350 /*
1351 * Before the policy is loaded, translate
1352 * SECINITSID_INIT to "kernel", because systemd and
1353 * libselinux < 2.6 take a getcon_raw() result that is
1354 * both non-null and not "kernel" to mean that a policy
1355 * is already loaded.
1356 */
1357 if (sid == SECINITSID_INIT)
1358 sid = SECINITSID_KERNEL;
1359
1360 s = initial_sid_to_string[sid];
1361 if (!s)
1362 return -EINVAL;
1363 *scontext_len = strlen(s) + 1;
1364 if (!scontext)
1365 return 0;
1366 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1367 if (!scontextp)
1368 return -ENOMEM;
1369 *scontext = scontextp;
1370 return 0;
1371 }
1372 pr_err("SELinux: %s: called before initial "
1373 "load_policy on unknown SID %d\n", __func__, sid);
1374 return -EINVAL;
1375 }
1376 rcu_read_lock();
1377 policy = rcu_dereference(selinux_state.policy);
1378 policydb = &policy->policydb;
1379 sidtab = policy->sidtab;
1380
1381 if (force)
1382 entry = sidtab_search_entry_force(sidtab, sid);
1383 else
1384 entry = sidtab_search_entry(sidtab, sid);
1385 if (!entry) {
1386 pr_err("SELinux: %s: unrecognized SID %d\n",
1387 __func__, sid);
1388 rc = -EINVAL;
1389 goto out_unlock;
1390 }
1391 if (only_invalid && !entry->context.len)
1392 goto out_unlock;
1393
1394 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1395 scontext_len);
1396
1397out_unlock:
1398 rcu_read_unlock();
1399 return rc;
1400
1401}
1402
1403/**
1404 * security_sid_to_context - Obtain a context for a given SID.
1405 * @sid: security identifier, SID
1406 * @scontext: security context
1407 * @scontext_len: length in bytes
1408 *
1409 * Write the string representation of the context associated with @sid
1410 * into a dynamically allocated string of the correct size. Set @scontext
1411 * to point to this string and set @scontext_len to the length of the string.
1412 */
1413int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1414{
1415 return security_sid_to_context_core(sid, scontext,
1416 scontext_len, 0, 0);
1417}
1418
1419int security_sid_to_context_force(u32 sid,
1420 char **scontext, u32 *scontext_len)
1421{
1422 return security_sid_to_context_core(sid, scontext,
1423 scontext_len, 1, 0);
1424}
1425
1426/**
1427 * security_sid_to_context_inval - Obtain a context for a given SID if it
1428 * is invalid.
1429 * @sid: security identifier, SID
1430 * @scontext: security context
1431 * @scontext_len: length in bytes
1432 *
1433 * Write the string representation of the context associated with @sid
1434 * into a dynamically allocated string of the correct size, but only if the
1435 * context is invalid in the current policy. Set @scontext to point to
1436 * this string (or NULL if the context is valid) and set @scontext_len to
1437 * the length of the string (or 0 if the context is valid).
1438 */
1439int security_sid_to_context_inval(u32 sid,
1440 char **scontext, u32 *scontext_len)
1441{
1442 return security_sid_to_context_core(sid, scontext,
1443 scontext_len, 1, 1);
1444}
1445
1446/*
1447 * Caveat: Mutates scontext.
1448 */
1449static int string_to_context_struct(struct policydb *pol,
1450 struct sidtab *sidtabp,
1451 char *scontext,
1452 struct context *ctx,
1453 u32 def_sid)
1454{
1455 struct role_datum *role;
1456 struct type_datum *typdatum;
1457 struct user_datum *usrdatum;
1458 char *scontextp, *p, oldc;
1459 int rc = 0;
1460
1461 context_init(ctx);
1462
1463 /* Parse the security context. */
1464
1465 rc = -EINVAL;
1466 scontextp = scontext;
1467
1468 /* Extract the user. */
1469 p = scontextp;
1470 while (*p && *p != ':')
1471 p++;
1472
1473 if (*p == 0)
1474 goto out;
1475
1476 *p++ = 0;
1477
1478 usrdatum = symtab_search(&pol->p_users, scontextp);
1479 if (!usrdatum)
1480 goto out;
1481
1482 ctx->user = usrdatum->value;
1483
1484 /* Extract role. */
1485 scontextp = p;
1486 while (*p && *p != ':')
1487 p++;
1488
1489 if (*p == 0)
1490 goto out;
1491
1492 *p++ = 0;
1493
1494 role = symtab_search(&pol->p_roles, scontextp);
1495 if (!role)
1496 goto out;
1497 ctx->role = role->value;
1498
1499 /* Extract type. */
1500 scontextp = p;
1501 while (*p && *p != ':')
1502 p++;
1503 oldc = *p;
1504 *p++ = 0;
1505
1506 typdatum = symtab_search(&pol->p_types, scontextp);
1507 if (!typdatum || typdatum->attribute)
1508 goto out;
1509
1510 ctx->type = typdatum->value;
1511
1512 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1513 if (rc)
1514 goto out;
1515
1516 /* Check the validity of the new context. */
1517 rc = -EINVAL;
1518 if (!policydb_context_isvalid(pol, ctx))
1519 goto out;
1520 rc = 0;
1521out:
1522 if (rc)
1523 context_destroy(ctx);
1524 return rc;
1525}
1526
1527static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1528 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1529 int force)
1530{
1531 struct selinux_policy *policy;
1532 struct policydb *policydb;
1533 struct sidtab *sidtab;
1534 char *scontext2, *str = NULL;
1535 struct context context;
1536 int rc = 0;
1537
1538 /* An empty security context is never valid. */
1539 if (!scontext_len)
1540 return -EINVAL;
1541
1542 /* Copy the string to allow changes and ensure a NUL terminator */
1543 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1544 if (!scontext2)
1545 return -ENOMEM;
1546
1547 if (!selinux_initialized()) {
1548 u32 i;
1549
1550 for (i = 1; i < SECINITSID_NUM; i++) {
1551 const char *s = initial_sid_to_string[i];
1552
1553 if (s && !strcmp(s, scontext2)) {
1554 *sid = i;
1555 goto out;
1556 }
1557 }
1558 *sid = SECINITSID_KERNEL;
1559 goto out;
1560 }
1561 *sid = SECSID_NULL;
1562
1563 if (force) {
1564 /* Save another copy for storing in uninterpreted form */
1565 rc = -ENOMEM;
1566 str = kstrdup(scontext2, gfp_flags);
1567 if (!str)
1568 goto out;
1569 }
1570retry:
1571 rcu_read_lock();
1572 policy = rcu_dereference(selinux_state.policy);
1573 policydb = &policy->policydb;
1574 sidtab = policy->sidtab;
1575 rc = string_to_context_struct(policydb, sidtab, scontext2,
1576 &context, def_sid);
1577 if (rc == -EINVAL && force) {
1578 context.str = str;
1579 context.len = strlen(str) + 1;
1580 str = NULL;
1581 } else if (rc)
1582 goto out_unlock;
1583 rc = sidtab_context_to_sid(sidtab, &context, sid);
1584 if (rc == -ESTALE) {
1585 rcu_read_unlock();
1586 if (context.str) {
1587 str = context.str;
1588 context.str = NULL;
1589 }
1590 context_destroy(&context);
1591 goto retry;
1592 }
1593 context_destroy(&context);
1594out_unlock:
1595 rcu_read_unlock();
1596out:
1597 kfree(scontext2);
1598 kfree(str);
1599 return rc;
1600}
1601
1602/**
1603 * security_context_to_sid - Obtain a SID for a given security context.
1604 * @scontext: security context
1605 * @scontext_len: length in bytes
1606 * @sid: security identifier, SID
1607 * @gfp: context for the allocation
1608 *
1609 * Obtains a SID associated with the security context that
1610 * has the string representation specified by @scontext.
1611 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1612 * memory is available, or 0 on success.
1613 */
1614int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1615 gfp_t gfp)
1616{
1617 return security_context_to_sid_core(scontext, scontext_len,
1618 sid, SECSID_NULL, gfp, 0);
1619}
1620
1621int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1622{
1623 return security_context_to_sid(scontext, strlen(scontext),
1624 sid, gfp);
1625}
1626
1627/**
1628 * security_context_to_sid_default - Obtain a SID for a given security context,
1629 * falling back to specified default if needed.
1630 *
1631 * @scontext: security context
1632 * @scontext_len: length in bytes
1633 * @sid: security identifier, SID
1634 * @def_sid: default SID to assign on error
1635 * @gfp_flags: the allocator get-free-page (GFP) flags
1636 *
1637 * Obtains a SID associated with the security context that
1638 * has the string representation specified by @scontext.
1639 * The default SID is passed to the MLS layer to be used to allow
1640 * kernel labeling of the MLS field if the MLS field is not present
1641 * (for upgrading to MLS without full relabel).
1642 * Implicitly forces adding of the context even if it cannot be mapped yet.
1643 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1644 * memory is available, or 0 on success.
1645 */
1646int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1647 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1648{
1649 return security_context_to_sid_core(scontext, scontext_len,
1650 sid, def_sid, gfp_flags, 1);
1651}
1652
1653int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1654 u32 *sid)
1655{
1656 return security_context_to_sid_core(scontext, scontext_len,
1657 sid, SECSID_NULL, GFP_KERNEL, 1);
1658}
1659
1660static int compute_sid_handle_invalid_context(
1661 struct selinux_policy *policy,
1662 struct sidtab_entry *sentry,
1663 struct sidtab_entry *tentry,
1664 u16 tclass,
1665 struct context *newcontext)
1666{
1667 struct policydb *policydb = &policy->policydb;
1668 struct sidtab *sidtab = policy->sidtab;
1669 char *s = NULL, *t = NULL, *n = NULL;
1670 u32 slen, tlen, nlen;
1671 struct audit_buffer *ab;
1672
1673 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1674 goto out;
1675 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1676 goto out;
1677 if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1678 goto out;
1679 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1680 if (!ab)
1681 goto out;
1682 audit_log_format(ab,
1683 "op=security_compute_sid invalid_context=");
1684 /* no need to record the NUL with untrusted strings */
1685 audit_log_n_untrustedstring(ab, n, nlen - 1);
1686 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1687 s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1688 audit_log_end(ab);
1689out:
1690 kfree(s);
1691 kfree(t);
1692 kfree(n);
1693 if (!enforcing_enabled())
1694 return 0;
1695 return -EACCES;
1696}
1697
1698static void filename_compute_type(struct policydb *policydb,
1699 struct context *newcontext,
1700 u32 stype, u32 ttype, u16 tclass,
1701 const char *objname)
1702{
1703 struct filename_trans_key ft;
1704 struct filename_trans_datum *datum;
1705
1706 /*
1707 * Most filename trans rules are going to live in specific directories
1708 * like /dev or /var/run. This bitmap will quickly skip rule searches
1709 * if the ttype does not contain any rules.
1710 */
1711 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1712 return;
1713
1714 ft.ttype = ttype;
1715 ft.tclass = tclass;
1716 ft.name = objname;
1717
1718 datum = policydb_filenametr_search(policydb, &ft);
1719 while (datum) {
1720 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1721 newcontext->type = datum->otype;
1722 return;
1723 }
1724 datum = datum->next;
1725 }
1726}
1727
1728static int security_compute_sid(u32 ssid,
1729 u32 tsid,
1730 u16 orig_tclass,
1731 u16 specified,
1732 const char *objname,
1733 u32 *out_sid,
1734 bool kern)
1735{
1736 struct selinux_policy *policy;
1737 struct policydb *policydb;
1738 struct sidtab *sidtab;
1739 struct class_datum *cladatum;
1740 struct context *scontext, *tcontext, newcontext;
1741 struct sidtab_entry *sentry, *tentry;
1742 struct avtab_key avkey;
1743 struct avtab_node *avnode, *node;
1744 u16 tclass;
1745 int rc = 0;
1746 bool sock;
1747
1748 if (!selinux_initialized()) {
1749 switch (orig_tclass) {
1750 case SECCLASS_PROCESS: /* kernel value */
1751 *out_sid = ssid;
1752 break;
1753 default:
1754 *out_sid = tsid;
1755 break;
1756 }
1757 goto out;
1758 }
1759
1760retry:
1761 cladatum = NULL;
1762 context_init(&newcontext);
1763
1764 rcu_read_lock();
1765
1766 policy = rcu_dereference(selinux_state.policy);
1767
1768 if (kern) {
1769 tclass = unmap_class(&policy->map, orig_tclass);
1770 sock = security_is_socket_class(orig_tclass);
1771 } else {
1772 tclass = orig_tclass;
1773 sock = security_is_socket_class(map_class(&policy->map,
1774 tclass));
1775 }
1776
1777 policydb = &policy->policydb;
1778 sidtab = policy->sidtab;
1779
1780 sentry = sidtab_search_entry(sidtab, ssid);
1781 if (!sentry) {
1782 pr_err("SELinux: %s: unrecognized SID %d\n",
1783 __func__, ssid);
1784 rc = -EINVAL;
1785 goto out_unlock;
1786 }
1787 tentry = sidtab_search_entry(sidtab, tsid);
1788 if (!tentry) {
1789 pr_err("SELinux: %s: unrecognized SID %d\n",
1790 __func__, tsid);
1791 rc = -EINVAL;
1792 goto out_unlock;
1793 }
1794
1795 scontext = &sentry->context;
1796 tcontext = &tentry->context;
1797
1798 if (tclass && tclass <= policydb->p_classes.nprim)
1799 cladatum = policydb->class_val_to_struct[tclass - 1];
1800
1801 /* Set the user identity. */
1802 switch (specified) {
1803 case AVTAB_TRANSITION:
1804 case AVTAB_CHANGE:
1805 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1806 newcontext.user = tcontext->user;
1807 } else {
1808 /* notice this gets both DEFAULT_SOURCE and unset */
1809 /* Use the process user identity. */
1810 newcontext.user = scontext->user;
1811 }
1812 break;
1813 case AVTAB_MEMBER:
1814 /* Use the related object owner. */
1815 newcontext.user = tcontext->user;
1816 break;
1817 }
1818
1819 /* Set the role to default values. */
1820 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1821 newcontext.role = scontext->role;
1822 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1823 newcontext.role = tcontext->role;
1824 } else {
1825 if ((tclass == policydb->process_class) || sock)
1826 newcontext.role = scontext->role;
1827 else
1828 newcontext.role = OBJECT_R_VAL;
1829 }
1830
1831 /* Set the type.
1832 * Look for a type transition/member/change rule.
1833 */
1834 avkey.source_type = scontext->type;
1835 avkey.target_type = tcontext->type;
1836 avkey.target_class = tclass;
1837 avkey.specified = specified;
1838 avnode = avtab_search_node(&policydb->te_avtab, &avkey);
1839
1840 /* If no permanent rule, also check for enabled conditional rules */
1841 if (!avnode) {
1842 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1843 for (; node; node = avtab_search_node_next(node, specified)) {
1844 if (node->key.specified & AVTAB_ENABLED) {
1845 avnode = node;
1846 break;
1847 }
1848 }
1849 }
1850
1851 /* If a permanent rule is found, use the type from
1852 * the type transition/member/change rule. Otherwise,
1853 * set the type to its default values.
1854 */
1855 if (avnode) {
1856 newcontext.type = avnode->datum.u.data;
1857 } else if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1858 newcontext.type = scontext->type;
1859 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1860 newcontext.type = tcontext->type;
1861 } else {
1862 if ((tclass == policydb->process_class) || sock) {
1863 /* Use the type of process. */
1864 newcontext.type = scontext->type;
1865 } else {
1866 /* Use the type of the related object. */
1867 newcontext.type = tcontext->type;
1868 }
1869 }
1870
1871 /* if we have a objname this is a file trans check so check those rules */
1872 if (objname)
1873 filename_compute_type(policydb, &newcontext, scontext->type,
1874 tcontext->type, tclass, objname);
1875
1876 /* Check for class-specific changes. */
1877 if (specified & AVTAB_TRANSITION) {
1878 /* Look for a role transition rule. */
1879 struct role_trans_datum *rtd;
1880 struct role_trans_key rtk = {
1881 .role = scontext->role,
1882 .type = tcontext->type,
1883 .tclass = tclass,
1884 };
1885
1886 rtd = policydb_roletr_search(policydb, &rtk);
1887 if (rtd)
1888 newcontext.role = rtd->new_role;
1889 }
1890
1891 /* Set the MLS attributes.
1892 This is done last because it may allocate memory. */
1893 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1894 &newcontext, sock);
1895 if (rc)
1896 goto out_unlock;
1897
1898 /* Check the validity of the context. */
1899 if (!policydb_context_isvalid(policydb, &newcontext)) {
1900 rc = compute_sid_handle_invalid_context(policy, sentry,
1901 tentry, tclass,
1902 &newcontext);
1903 if (rc)
1904 goto out_unlock;
1905 }
1906 /* Obtain the sid for the context. */
1907 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1908 if (rc == -ESTALE) {
1909 rcu_read_unlock();
1910 context_destroy(&newcontext);
1911 goto retry;
1912 }
1913out_unlock:
1914 rcu_read_unlock();
1915 context_destroy(&newcontext);
1916out:
1917 return rc;
1918}
1919
1920/**
1921 * security_transition_sid - Compute the SID for a new subject/object.
1922 * @ssid: source security identifier
1923 * @tsid: target security identifier
1924 * @tclass: target security class
1925 * @qstr: object name
1926 * @out_sid: security identifier for new subject/object
1927 *
1928 * Compute a SID to use for labeling a new subject or object in the
1929 * class @tclass based on a SID pair (@ssid, @tsid).
1930 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1931 * if insufficient memory is available, or %0 if the new SID was
1932 * computed successfully.
1933 */
1934int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1935 const struct qstr *qstr, u32 *out_sid)
1936{
1937 return security_compute_sid(ssid, tsid, tclass,
1938 AVTAB_TRANSITION,
1939 qstr ? qstr->name : NULL, out_sid, true);
1940}
1941
1942int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1943 const char *objname, u32 *out_sid)
1944{
1945 return security_compute_sid(ssid, tsid, tclass,
1946 AVTAB_TRANSITION,
1947 objname, out_sid, false);
1948}
1949
1950/**
1951 * security_member_sid - Compute the SID for member selection.
1952 * @ssid: source security identifier
1953 * @tsid: target security identifier
1954 * @tclass: target security class
1955 * @out_sid: security identifier for selected member
1956 *
1957 * Compute a SID to use when selecting a member of a polyinstantiated
1958 * object of class @tclass based on a SID pair (@ssid, @tsid).
1959 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1960 * if insufficient memory is available, or %0 if the SID was
1961 * computed successfully.
1962 */
1963int security_member_sid(u32 ssid,
1964 u32 tsid,
1965 u16 tclass,
1966 u32 *out_sid)
1967{
1968 return security_compute_sid(ssid, tsid, tclass,
1969 AVTAB_MEMBER, NULL,
1970 out_sid, false);
1971}
1972
1973/**
1974 * security_change_sid - Compute the SID for object relabeling.
1975 * @ssid: source security identifier
1976 * @tsid: target security identifier
1977 * @tclass: target security class
1978 * @out_sid: security identifier for selected member
1979 *
1980 * Compute a SID to use for relabeling an object of class @tclass
1981 * based on a SID pair (@ssid, @tsid).
1982 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1983 * if insufficient memory is available, or %0 if the SID was
1984 * computed successfully.
1985 */
1986int security_change_sid(u32 ssid,
1987 u32 tsid,
1988 u16 tclass,
1989 u32 *out_sid)
1990{
1991 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1992 out_sid, false);
1993}
1994
1995static inline int convert_context_handle_invalid_context(
1996 struct policydb *policydb,
1997 struct context *context)
1998{
1999 char *s;
2000 u32 len;
2001
2002 if (enforcing_enabled())
2003 return -EINVAL;
2004
2005 if (!context_struct_to_string(policydb, context, &s, &len)) {
2006 pr_warn("SELinux: Context %s would be invalid if enforcing\n",
2007 s);
2008 kfree(s);
2009 }
2010 return 0;
2011}
2012
2013/**
2014 * services_convert_context - Convert a security context across policies.
2015 * @args: populated convert_context_args struct
2016 * @oldc: original context
2017 * @newc: converted context
2018 * @gfp_flags: allocation flags
2019 *
2020 * Convert the values in the security context structure @oldc from the values
2021 * specified in the policy @args->oldp to the values specified in the policy
2022 * @args->newp, storing the new context in @newc, and verifying that the
2023 * context is valid under the new policy.
2024 */
2025int services_convert_context(struct convert_context_args *args,
2026 struct context *oldc, struct context *newc,
2027 gfp_t gfp_flags)
2028{
2029 struct ocontext *oc;
2030 struct role_datum *role;
2031 struct type_datum *typdatum;
2032 struct user_datum *usrdatum;
2033 char *s;
2034 u32 len;
2035 int rc;
2036
2037 if (oldc->str) {
2038 s = kstrdup(oldc->str, gfp_flags);
2039 if (!s)
2040 return -ENOMEM;
2041
2042 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL);
2043 if (rc == -EINVAL) {
2044 /*
2045 * Retain string representation for later mapping.
2046 *
2047 * IMPORTANT: We need to copy the contents of oldc->str
2048 * back into s again because string_to_context_struct()
2049 * may have garbled it.
2050 */
2051 memcpy(s, oldc->str, oldc->len);
2052 context_init(newc);
2053 newc->str = s;
2054 newc->len = oldc->len;
2055 return 0;
2056 }
2057 kfree(s);
2058 if (rc) {
2059 /* Other error condition, e.g. ENOMEM. */
2060 pr_err("SELinux: Unable to map context %s, rc = %d.\n",
2061 oldc->str, -rc);
2062 return rc;
2063 }
2064 pr_info("SELinux: Context %s became valid (mapped).\n",
2065 oldc->str);
2066 return 0;
2067 }
2068
2069 context_init(newc);
2070
2071 /* Convert the user. */
2072 usrdatum = symtab_search(&args->newp->p_users,
2073 sym_name(args->oldp, SYM_USERS, oldc->user - 1));
2074 if (!usrdatum)
2075 goto bad;
2076 newc->user = usrdatum->value;
2077
2078 /* Convert the role. */
2079 role = symtab_search(&args->newp->p_roles,
2080 sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2081 if (!role)
2082 goto bad;
2083 newc->role = role->value;
2084
2085 /* Convert the type. */
2086 typdatum = symtab_search(&args->newp->p_types,
2087 sym_name(args->oldp, SYM_TYPES, oldc->type - 1));
2088 if (!typdatum)
2089 goto bad;
2090 newc->type = typdatum->value;
2091
2092 /* Convert the MLS fields if dealing with MLS policies */
2093 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2094 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2095 if (rc)
2096 goto bad;
2097 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2098 /*
2099 * Switching between non-MLS and MLS policy:
2100 * ensure that the MLS fields of the context for all
2101 * existing entries in the sidtab are filled in with a
2102 * suitable default value, likely taken from one of the
2103 * initial SIDs.
2104 */
2105 oc = args->newp->ocontexts[OCON_ISID];
2106 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2107 oc = oc->next;
2108 if (!oc) {
2109 pr_err("SELinux: unable to look up"
2110 " the initial SIDs list\n");
2111 goto bad;
2112 }
2113 rc = mls_range_set(newc, &oc->context[0].range);
2114 if (rc)
2115 goto bad;
2116 }
2117
2118 /* Check the validity of the new context. */
2119 if (!policydb_context_isvalid(args->newp, newc)) {
2120 rc = convert_context_handle_invalid_context(args->oldp, oldc);
2121 if (rc)
2122 goto bad;
2123 }
2124
2125 return 0;
2126bad:
2127 /* Map old representation to string and save it. */
2128 rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2129 if (rc)
2130 return rc;
2131 context_destroy(newc);
2132 newc->str = s;
2133 newc->len = len;
2134 pr_info("SELinux: Context %s became invalid (unmapped).\n",
2135 newc->str);
2136 return 0;
2137}
2138
2139static void security_load_policycaps(struct selinux_policy *policy)
2140{
2141 struct policydb *p;
2142 unsigned int i;
2143 struct ebitmap_node *node;
2144
2145 p = &policy->policydb;
2146
2147 for (i = 0; i < ARRAY_SIZE(selinux_state.policycap); i++)
2148 WRITE_ONCE(selinux_state.policycap[i],
2149 ebitmap_get_bit(&p->policycaps, i));
2150
2151 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2152 pr_info("SELinux: policy capability %s=%d\n",
2153 selinux_policycap_names[i],
2154 ebitmap_get_bit(&p->policycaps, i));
2155
2156 ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2157 if (i >= ARRAY_SIZE(selinux_policycap_names))
2158 pr_info("SELinux: unknown policy capability %u\n",
2159 i);
2160 }
2161}
2162
2163static int security_preserve_bools(struct selinux_policy *oldpolicy,
2164 struct selinux_policy *newpolicy);
2165
2166static void selinux_policy_free(struct selinux_policy *policy)
2167{
2168 if (!policy)
2169 return;
2170
2171 sidtab_destroy(policy->sidtab);
2172 kfree(policy->map.mapping);
2173 policydb_destroy(&policy->policydb);
2174 kfree(policy->sidtab);
2175 kfree(policy);
2176}
2177
2178static void selinux_policy_cond_free(struct selinux_policy *policy)
2179{
2180 cond_policydb_destroy_dup(&policy->policydb);
2181 kfree(policy);
2182}
2183
2184void selinux_policy_cancel(struct selinux_load_state *load_state)
2185{
2186 struct selinux_state *state = &selinux_state;
2187 struct selinux_policy *oldpolicy;
2188
2189 oldpolicy = rcu_dereference_protected(state->policy,
2190 lockdep_is_held(&state->policy_mutex));
2191
2192 sidtab_cancel_convert(oldpolicy->sidtab);
2193 selinux_policy_free(load_state->policy);
2194 kfree(load_state->convert_data);
2195}
2196
2197static void selinux_notify_policy_change(u32 seqno)
2198{
2199 /* Flush external caches and notify userspace of policy load */
2200 avc_ss_reset(seqno);
2201 selnl_notify_policyload(seqno);
2202 selinux_status_update_policyload(seqno);
2203 selinux_netlbl_cache_invalidate();
2204 selinux_xfrm_notify_policyload();
2205 selinux_ima_measure_state_locked();
2206}
2207
2208void selinux_policy_commit(struct selinux_load_state *load_state)
2209{
2210 struct selinux_state *state = &selinux_state;
2211 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
2212 unsigned long flags;
2213 u32 seqno;
2214
2215 oldpolicy = rcu_dereference_protected(state->policy,
2216 lockdep_is_held(&state->policy_mutex));
2217
2218 /* If switching between different policy types, log MLS status */
2219 if (oldpolicy) {
2220 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
2221 pr_info("SELinux: Disabling MLS support...\n");
2222 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
2223 pr_info("SELinux: Enabling MLS support...\n");
2224 }
2225
2226 /* Set latest granting seqno for new policy. */
2227 if (oldpolicy)
2228 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
2229 else
2230 newpolicy->latest_granting = 1;
2231 seqno = newpolicy->latest_granting;
2232
2233 /* Install the new policy. */
2234 if (oldpolicy) {
2235 sidtab_freeze_begin(oldpolicy->sidtab, &flags);
2236 rcu_assign_pointer(state->policy, newpolicy);
2237 sidtab_freeze_end(oldpolicy->sidtab, &flags);
2238 } else {
2239 rcu_assign_pointer(state->policy, newpolicy);
2240 }
2241
2242 /* Load the policycaps from the new policy */
2243 security_load_policycaps(newpolicy);
2244
2245 if (!selinux_initialized()) {
2246 /*
2247 * After first policy load, the security server is
2248 * marked as initialized and ready to handle requests and
2249 * any objects created prior to policy load are then labeled.
2250 */
2251 selinux_mark_initialized();
2252 selinux_complete_init();
2253 }
2254
2255 /* Free the old policy */
2256 synchronize_rcu();
2257 selinux_policy_free(oldpolicy);
2258 kfree(load_state->convert_data);
2259
2260 /* Notify others of the policy change */
2261 selinux_notify_policy_change(seqno);
2262}
2263
2264/**
2265 * security_load_policy - Load a security policy configuration.
2266 * @data: binary policy data
2267 * @len: length of data in bytes
2268 * @load_state: policy load state
2269 *
2270 * Load a new set of security policy configuration data,
2271 * validate it and convert the SID table as necessary.
2272 * This function will flush the access vector cache after
2273 * loading the new policy.
2274 */
2275int security_load_policy(void *data, size_t len,
2276 struct selinux_load_state *load_state)
2277{
2278 struct selinux_state *state = &selinux_state;
2279 struct selinux_policy *newpolicy, *oldpolicy;
2280 struct selinux_policy_convert_data *convert_data;
2281 int rc = 0;
2282 struct policy_file file = { data, len }, *fp = &file;
2283
2284 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2285 if (!newpolicy)
2286 return -ENOMEM;
2287
2288 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2289 if (!newpolicy->sidtab) {
2290 rc = -ENOMEM;
2291 goto err_policy;
2292 }
2293
2294 rc = policydb_read(&newpolicy->policydb, fp);
2295 if (rc)
2296 goto err_sidtab;
2297
2298 newpolicy->policydb.len = len;
2299 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2300 &newpolicy->map);
2301 if (rc)
2302 goto err_policydb;
2303
2304 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2305 if (rc) {
2306 pr_err("SELinux: unable to load the initial SIDs\n");
2307 goto err_mapping;
2308 }
2309
2310 if (!selinux_initialized()) {
2311 /* First policy load, so no need to preserve state from old policy */
2312 load_state->policy = newpolicy;
2313 load_state->convert_data = NULL;
2314 return 0;
2315 }
2316
2317 oldpolicy = rcu_dereference_protected(state->policy,
2318 lockdep_is_held(&state->policy_mutex));
2319
2320 /* Preserve active boolean values from the old policy */
2321 rc = security_preserve_bools(oldpolicy, newpolicy);
2322 if (rc) {
2323 pr_err("SELinux: unable to preserve booleans\n");
2324 goto err_free_isids;
2325 }
2326
2327 /*
2328 * Convert the internal representations of contexts
2329 * in the new SID table.
2330 */
2331
2332 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2333 if (!convert_data) {
2334 rc = -ENOMEM;
2335 goto err_free_isids;
2336 }
2337
2338 convert_data->args.oldp = &oldpolicy->policydb;
2339 convert_data->args.newp = &newpolicy->policydb;
2340
2341 convert_data->sidtab_params.args = &convert_data->args;
2342 convert_data->sidtab_params.target = newpolicy->sidtab;
2343
2344 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2345 if (rc) {
2346 pr_err("SELinux: unable to convert the internal"
2347 " representation of contexts in the new SID"
2348 " table\n");
2349 goto err_free_convert_data;
2350 }
2351
2352 load_state->policy = newpolicy;
2353 load_state->convert_data = convert_data;
2354 return 0;
2355
2356err_free_convert_data:
2357 kfree(convert_data);
2358err_free_isids:
2359 sidtab_destroy(newpolicy->sidtab);
2360err_mapping:
2361 kfree(newpolicy->map.mapping);
2362err_policydb:
2363 policydb_destroy(&newpolicy->policydb);
2364err_sidtab:
2365 kfree(newpolicy->sidtab);
2366err_policy:
2367 kfree(newpolicy);
2368
2369 return rc;
2370}
2371
2372/**
2373 * ocontext_to_sid - Helper to safely get sid for an ocontext
2374 * @sidtab: SID table
2375 * @c: ocontext structure
2376 * @index: index of the context entry (0 or 1)
2377 * @out_sid: pointer to the resulting SID value
2378 *
2379 * For all ocontexts except OCON_ISID the SID fields are populated
2380 * on-demand when needed. Since updating the SID value is an SMP-sensitive
2381 * operation, this helper must be used to do that safely.
2382 *
2383 * WARNING: This function may return -ESTALE, indicating that the caller
2384 * must retry the operation after re-acquiring the policy pointer!
2385 */
2386static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
2387 size_t index, u32 *out_sid)
2388{
2389 int rc;
2390 u32 sid;
2391
2392 /* Ensure the associated sidtab entry is visible to this thread. */
2393 sid = smp_load_acquire(&c->sid[index]);
2394 if (!sid) {
2395 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
2396 if (rc)
2397 return rc;
2398
2399 /*
2400 * Ensure the new sidtab entry is visible to other threads
2401 * when they see the SID.
2402 */
2403 smp_store_release(&c->sid[index], sid);
2404 }
2405 *out_sid = sid;
2406 return 0;
2407}
2408
2409/**
2410 * security_port_sid - Obtain the SID for a port.
2411 * @protocol: protocol number
2412 * @port: port number
2413 * @out_sid: security identifier
2414 */
2415int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2416{
2417 struct selinux_policy *policy;
2418 struct policydb *policydb;
2419 struct sidtab *sidtab;
2420 struct ocontext *c;
2421 int rc;
2422
2423 if (!selinux_initialized()) {
2424 *out_sid = SECINITSID_PORT;
2425 return 0;
2426 }
2427
2428retry:
2429 rc = 0;
2430 rcu_read_lock();
2431 policy = rcu_dereference(selinux_state.policy);
2432 policydb = &policy->policydb;
2433 sidtab = policy->sidtab;
2434
2435 c = policydb->ocontexts[OCON_PORT];
2436 while (c) {
2437 if (c->u.port.protocol == protocol &&
2438 c->u.port.low_port <= port &&
2439 c->u.port.high_port >= port)
2440 break;
2441 c = c->next;
2442 }
2443
2444 if (c) {
2445 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2446 if (rc == -ESTALE) {
2447 rcu_read_unlock();
2448 goto retry;
2449 }
2450 if (rc)
2451 goto out;
2452 } else {
2453 *out_sid = SECINITSID_PORT;
2454 }
2455
2456out:
2457 rcu_read_unlock();
2458 return rc;
2459}
2460
2461/**
2462 * security_ib_pkey_sid - Obtain the SID for a pkey.
2463 * @subnet_prefix: Subnet Prefix
2464 * @pkey_num: pkey number
2465 * @out_sid: security identifier
2466 */
2467int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2468{
2469 struct selinux_policy *policy;
2470 struct policydb *policydb;
2471 struct sidtab *sidtab;
2472 struct ocontext *c;
2473 int rc;
2474
2475 if (!selinux_initialized()) {
2476 *out_sid = SECINITSID_UNLABELED;
2477 return 0;
2478 }
2479
2480retry:
2481 rc = 0;
2482 rcu_read_lock();
2483 policy = rcu_dereference(selinux_state.policy);
2484 policydb = &policy->policydb;
2485 sidtab = policy->sidtab;
2486
2487 c = policydb->ocontexts[OCON_IBPKEY];
2488 while (c) {
2489 if (c->u.ibpkey.low_pkey <= pkey_num &&
2490 c->u.ibpkey.high_pkey >= pkey_num &&
2491 c->u.ibpkey.subnet_prefix == subnet_prefix)
2492 break;
2493
2494 c = c->next;
2495 }
2496
2497 if (c) {
2498 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2499 if (rc == -ESTALE) {
2500 rcu_read_unlock();
2501 goto retry;
2502 }
2503 if (rc)
2504 goto out;
2505 } else
2506 *out_sid = SECINITSID_UNLABELED;
2507
2508out:
2509 rcu_read_unlock();
2510 return rc;
2511}
2512
2513/**
2514 * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2515 * @dev_name: device name
2516 * @port_num: port number
2517 * @out_sid: security identifier
2518 */
2519int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid)
2520{
2521 struct selinux_policy *policy;
2522 struct policydb *policydb;
2523 struct sidtab *sidtab;
2524 struct ocontext *c;
2525 int rc;
2526
2527 if (!selinux_initialized()) {
2528 *out_sid = SECINITSID_UNLABELED;
2529 return 0;
2530 }
2531
2532retry:
2533 rc = 0;
2534 rcu_read_lock();
2535 policy = rcu_dereference(selinux_state.policy);
2536 policydb = &policy->policydb;
2537 sidtab = policy->sidtab;
2538
2539 c = policydb->ocontexts[OCON_IBENDPORT];
2540 while (c) {
2541 if (c->u.ibendport.port == port_num &&
2542 !strncmp(c->u.ibendport.dev_name,
2543 dev_name,
2544 IB_DEVICE_NAME_MAX))
2545 break;
2546
2547 c = c->next;
2548 }
2549
2550 if (c) {
2551 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2552 if (rc == -ESTALE) {
2553 rcu_read_unlock();
2554 goto retry;
2555 }
2556 if (rc)
2557 goto out;
2558 } else
2559 *out_sid = SECINITSID_UNLABELED;
2560
2561out:
2562 rcu_read_unlock();
2563 return rc;
2564}
2565
2566/**
2567 * security_netif_sid - Obtain the SID for a network interface.
2568 * @name: interface name
2569 * @if_sid: interface SID
2570 */
2571int security_netif_sid(char *name, u32 *if_sid)
2572{
2573 struct selinux_policy *policy;
2574 struct policydb *policydb;
2575 struct sidtab *sidtab;
2576 int rc;
2577 struct ocontext *c;
2578
2579 if (!selinux_initialized()) {
2580 *if_sid = SECINITSID_NETIF;
2581 return 0;
2582 }
2583
2584retry:
2585 rc = 0;
2586 rcu_read_lock();
2587 policy = rcu_dereference(selinux_state.policy);
2588 policydb = &policy->policydb;
2589 sidtab = policy->sidtab;
2590
2591 c = policydb->ocontexts[OCON_NETIF];
2592 while (c) {
2593 if (strcmp(name, c->u.name) == 0)
2594 break;
2595 c = c->next;
2596 }
2597
2598 if (c) {
2599 rc = ocontext_to_sid(sidtab, c, 0, if_sid);
2600 if (rc == -ESTALE) {
2601 rcu_read_unlock();
2602 goto retry;
2603 }
2604 if (rc)
2605 goto out;
2606 } else
2607 *if_sid = SECINITSID_NETIF;
2608
2609out:
2610 rcu_read_unlock();
2611 return rc;
2612}
2613
2614static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2615{
2616 int i, fail = 0;
2617
2618 for (i = 0; i < 4; i++)
2619 if (addr[i] != (input[i] & mask[i])) {
2620 fail = 1;
2621 break;
2622 }
2623
2624 return !fail;
2625}
2626
2627/**
2628 * security_node_sid - Obtain the SID for a node (host).
2629 * @domain: communication domain aka address family
2630 * @addrp: address
2631 * @addrlen: address length in bytes
2632 * @out_sid: security identifier
2633 */
2634int security_node_sid(u16 domain,
2635 void *addrp,
2636 u32 addrlen,
2637 u32 *out_sid)
2638{
2639 struct selinux_policy *policy;
2640 struct policydb *policydb;
2641 struct sidtab *sidtab;
2642 int rc;
2643 struct ocontext *c;
2644
2645 if (!selinux_initialized()) {
2646 *out_sid = SECINITSID_NODE;
2647 return 0;
2648 }
2649
2650retry:
2651 rcu_read_lock();
2652 policy = rcu_dereference(selinux_state.policy);
2653 policydb = &policy->policydb;
2654 sidtab = policy->sidtab;
2655
2656 switch (domain) {
2657 case AF_INET: {
2658 u32 addr;
2659
2660 rc = -EINVAL;
2661 if (addrlen != sizeof(u32))
2662 goto out;
2663
2664 addr = *((u32 *)addrp);
2665
2666 c = policydb->ocontexts[OCON_NODE];
2667 while (c) {
2668 if (c->u.node.addr == (addr & c->u.node.mask))
2669 break;
2670 c = c->next;
2671 }
2672 break;
2673 }
2674
2675 case AF_INET6:
2676 rc = -EINVAL;
2677 if (addrlen != sizeof(u64) * 2)
2678 goto out;
2679 c = policydb->ocontexts[OCON_NODE6];
2680 while (c) {
2681 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2682 c->u.node6.mask))
2683 break;
2684 c = c->next;
2685 }
2686 break;
2687
2688 default:
2689 rc = 0;
2690 *out_sid = SECINITSID_NODE;
2691 goto out;
2692 }
2693
2694 if (c) {
2695 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2696 if (rc == -ESTALE) {
2697 rcu_read_unlock();
2698 goto retry;
2699 }
2700 if (rc)
2701 goto out;
2702 } else {
2703 *out_sid = SECINITSID_NODE;
2704 }
2705
2706 rc = 0;
2707out:
2708 rcu_read_unlock();
2709 return rc;
2710}
2711
2712#define SIDS_NEL 25
2713
2714/**
2715 * security_get_user_sids - Obtain reachable SIDs for a user.
2716 * @fromsid: starting SID
2717 * @username: username
2718 * @sids: array of reachable SIDs for user
2719 * @nel: number of elements in @sids
2720 *
2721 * Generate the set of SIDs for legal security contexts
2722 * for a given user that can be reached by @fromsid.
2723 * Set *@sids to point to a dynamically allocated
2724 * array containing the set of SIDs. Set *@nel to the
2725 * number of elements in the array.
2726 */
2727
2728int security_get_user_sids(u32 fromsid,
2729 char *username,
2730 u32 **sids,
2731 u32 *nel)
2732{
2733 struct selinux_policy *policy;
2734 struct policydb *policydb;
2735 struct sidtab *sidtab;
2736 struct context *fromcon, usercon;
2737 u32 *mysids = NULL, *mysids2, sid;
2738 u32 i, j, mynel, maxnel = SIDS_NEL;
2739 struct user_datum *user;
2740 struct role_datum *role;
2741 struct ebitmap_node *rnode, *tnode;
2742 int rc;
2743
2744 *sids = NULL;
2745 *nel = 0;
2746
2747 if (!selinux_initialized())
2748 return 0;
2749
2750 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2751 if (!mysids)
2752 return -ENOMEM;
2753
2754retry:
2755 mynel = 0;
2756 rcu_read_lock();
2757 policy = rcu_dereference(selinux_state.policy);
2758 policydb = &policy->policydb;
2759 sidtab = policy->sidtab;
2760
2761 context_init(&usercon);
2762
2763 rc = -EINVAL;
2764 fromcon = sidtab_search(sidtab, fromsid);
2765 if (!fromcon)
2766 goto out_unlock;
2767
2768 rc = -EINVAL;
2769 user = symtab_search(&policydb->p_users, username);
2770 if (!user)
2771 goto out_unlock;
2772
2773 usercon.user = user->value;
2774
2775 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2776 role = policydb->role_val_to_struct[i];
2777 usercon.role = i + 1;
2778 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2779 usercon.type = j + 1;
2780
2781 if (mls_setup_user_range(policydb, fromcon, user,
2782 &usercon))
2783 continue;
2784
2785 rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2786 if (rc == -ESTALE) {
2787 rcu_read_unlock();
2788 goto retry;
2789 }
2790 if (rc)
2791 goto out_unlock;
2792 if (mynel < maxnel) {
2793 mysids[mynel++] = sid;
2794 } else {
2795 rc = -ENOMEM;
2796 maxnel += SIDS_NEL;
2797 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2798 if (!mysids2)
2799 goto out_unlock;
2800 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2801 kfree(mysids);
2802 mysids = mysids2;
2803 mysids[mynel++] = sid;
2804 }
2805 }
2806 }
2807 rc = 0;
2808out_unlock:
2809 rcu_read_unlock();
2810 if (rc || !mynel) {
2811 kfree(mysids);
2812 return rc;
2813 }
2814
2815 rc = -ENOMEM;
2816 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2817 if (!mysids2) {
2818 kfree(mysids);
2819 return rc;
2820 }
2821 for (i = 0, j = 0; i < mynel; i++) {
2822 struct av_decision dummy_avd;
2823 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2824 SECCLASS_PROCESS, /* kernel value */
2825 PROCESS__TRANSITION, AVC_STRICT,
2826 &dummy_avd);
2827 if (!rc)
2828 mysids2[j++] = mysids[i];
2829 cond_resched();
2830 }
2831 kfree(mysids);
2832 *sids = mysids2;
2833 *nel = j;
2834 return 0;
2835}
2836
2837/**
2838 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2839 * @policy: policy
2840 * @fstype: filesystem type
2841 * @path: path from root of mount
2842 * @orig_sclass: file security class
2843 * @sid: SID for path
2844 *
2845 * Obtain a SID to use for a file in a filesystem that
2846 * cannot support xattr or use a fixed labeling behavior like
2847 * transition SIDs or task SIDs.
2848 *
2849 * WARNING: This function may return -ESTALE, indicating that the caller
2850 * must retry the operation after re-acquiring the policy pointer!
2851 */
2852static inline int __security_genfs_sid(struct selinux_policy *policy,
2853 const char *fstype,
2854 const char *path,
2855 u16 orig_sclass,
2856 u32 *sid)
2857{
2858 struct policydb *policydb = &policy->policydb;
2859 struct sidtab *sidtab = policy->sidtab;
2860 u16 sclass;
2861 struct genfs *genfs;
2862 struct ocontext *c;
2863 int cmp = 0;
2864
2865 while (path[0] == '/' && path[1] == '/')
2866 path++;
2867
2868 sclass = unmap_class(&policy->map, orig_sclass);
2869 *sid = SECINITSID_UNLABELED;
2870
2871 for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2872 cmp = strcmp(fstype, genfs->fstype);
2873 if (cmp <= 0)
2874 break;
2875 }
2876
2877 if (!genfs || cmp)
2878 return -ENOENT;
2879
2880 for (c = genfs->head; c; c = c->next) {
2881 size_t len = strlen(c->u.name);
2882 if ((!c->v.sclass || sclass == c->v.sclass) &&
2883 (strncmp(c->u.name, path, len) == 0))
2884 break;
2885 }
2886
2887 if (!c)
2888 return -ENOENT;
2889
2890 return ocontext_to_sid(sidtab, c, 0, sid);
2891}
2892
2893/**
2894 * security_genfs_sid - Obtain a SID for a file in a filesystem
2895 * @fstype: filesystem type
2896 * @path: path from root of mount
2897 * @orig_sclass: file security class
2898 * @sid: SID for path
2899 *
2900 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2901 * it afterward.
2902 */
2903int security_genfs_sid(const char *fstype,
2904 const char *path,
2905 u16 orig_sclass,
2906 u32 *sid)
2907{
2908 struct selinux_policy *policy;
2909 int retval;
2910
2911 if (!selinux_initialized()) {
2912 *sid = SECINITSID_UNLABELED;
2913 return 0;
2914 }
2915
2916 do {
2917 rcu_read_lock();
2918 policy = rcu_dereference(selinux_state.policy);
2919 retval = __security_genfs_sid(policy, fstype, path,
2920 orig_sclass, sid);
2921 rcu_read_unlock();
2922 } while (retval == -ESTALE);
2923 return retval;
2924}
2925
2926int selinux_policy_genfs_sid(struct selinux_policy *policy,
2927 const char *fstype,
2928 const char *path,
2929 u16 orig_sclass,
2930 u32 *sid)
2931{
2932 /* no lock required, policy is not yet accessible by other threads */
2933 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2934}
2935
2936/**
2937 * security_fs_use - Determine how to handle labeling for a filesystem.
2938 * @sb: superblock in question
2939 */
2940int security_fs_use(struct super_block *sb)
2941{
2942 struct selinux_policy *policy;
2943 struct policydb *policydb;
2944 struct sidtab *sidtab;
2945 int rc;
2946 struct ocontext *c;
2947 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2948 const char *fstype = sb->s_type->name;
2949
2950 if (!selinux_initialized()) {
2951 sbsec->behavior = SECURITY_FS_USE_NONE;
2952 sbsec->sid = SECINITSID_UNLABELED;
2953 return 0;
2954 }
2955
2956retry:
2957 rcu_read_lock();
2958 policy = rcu_dereference(selinux_state.policy);
2959 policydb = &policy->policydb;
2960 sidtab = policy->sidtab;
2961
2962 c = policydb->ocontexts[OCON_FSUSE];
2963 while (c) {
2964 if (strcmp(fstype, c->u.name) == 0)
2965 break;
2966 c = c->next;
2967 }
2968
2969 if (c) {
2970 sbsec->behavior = c->v.behavior;
2971 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
2972 if (rc == -ESTALE) {
2973 rcu_read_unlock();
2974 goto retry;
2975 }
2976 if (rc)
2977 goto out;
2978 } else {
2979 rc = __security_genfs_sid(policy, fstype, "/",
2980 SECCLASS_DIR, &sbsec->sid);
2981 if (rc == -ESTALE) {
2982 rcu_read_unlock();
2983 goto retry;
2984 }
2985 if (rc) {
2986 sbsec->behavior = SECURITY_FS_USE_NONE;
2987 rc = 0;
2988 } else {
2989 sbsec->behavior = SECURITY_FS_USE_GENFS;
2990 }
2991 }
2992
2993out:
2994 rcu_read_unlock();
2995 return rc;
2996}
2997
2998int security_get_bools(struct selinux_policy *policy,
2999 u32 *len, char ***names, int **values)
3000{
3001 struct policydb *policydb;
3002 u32 i;
3003 int rc;
3004
3005 policydb = &policy->policydb;
3006
3007 *names = NULL;
3008 *values = NULL;
3009
3010 rc = 0;
3011 *len = policydb->p_bools.nprim;
3012 if (!*len)
3013 goto out;
3014
3015 rc = -ENOMEM;
3016 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
3017 if (!*names)
3018 goto err;
3019
3020 rc = -ENOMEM;
3021 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
3022 if (!*values)
3023 goto err;
3024
3025 for (i = 0; i < *len; i++) {
3026 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3027
3028 rc = -ENOMEM;
3029 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3030 GFP_ATOMIC);
3031 if (!(*names)[i])
3032 goto err;
3033 }
3034 rc = 0;
3035out:
3036 return rc;
3037err:
3038 if (*names) {
3039 for (i = 0; i < *len; i++)
3040 kfree((*names)[i]);
3041 kfree(*names);
3042 }
3043 kfree(*values);
3044 *len = 0;
3045 *names = NULL;
3046 *values = NULL;
3047 goto out;
3048}
3049
3050
3051int security_set_bools(u32 len, int *values)
3052{
3053 struct selinux_state *state = &selinux_state;
3054 struct selinux_policy *newpolicy, *oldpolicy;
3055 int rc;
3056 u32 i, seqno = 0;
3057
3058 if (!selinux_initialized())
3059 return -EINVAL;
3060
3061 oldpolicy = rcu_dereference_protected(state->policy,
3062 lockdep_is_held(&state->policy_mutex));
3063
3064 /* Consistency check on number of booleans, should never fail */
3065 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3066 return -EINVAL;
3067
3068 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3069 if (!newpolicy)
3070 return -ENOMEM;
3071
3072 /*
3073 * Deep copy only the parts of the policydb that might be
3074 * modified as a result of changing booleans.
3075 */
3076 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3077 if (rc) {
3078 kfree(newpolicy);
3079 return -ENOMEM;
3080 }
3081
3082 /* Update the boolean states in the copy */
3083 for (i = 0; i < len; i++) {
3084 int new_state = !!values[i];
3085 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3086
3087 if (new_state != old_state) {
3088 audit_log(audit_context(), GFP_ATOMIC,
3089 AUDIT_MAC_CONFIG_CHANGE,
3090 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3091 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3092 new_state,
3093 old_state,
3094 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3095 audit_get_sessionid(current));
3096 newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3097 }
3098 }
3099
3100 /* Re-evaluate the conditional rules in the copy */
3101 evaluate_cond_nodes(&newpolicy->policydb);
3102
3103 /* Set latest granting seqno for new policy */
3104 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3105 seqno = newpolicy->latest_granting;
3106
3107 /* Install the new policy */
3108 rcu_assign_pointer(state->policy, newpolicy);
3109
3110 /*
3111 * Free the conditional portions of the old policydb
3112 * that were copied for the new policy, and the oldpolicy
3113 * structure itself but not what it references.
3114 */
3115 synchronize_rcu();
3116 selinux_policy_cond_free(oldpolicy);
3117
3118 /* Notify others of the policy change */
3119 selinux_notify_policy_change(seqno);
3120 return 0;
3121}
3122
3123int security_get_bool_value(u32 index)
3124{
3125 struct selinux_policy *policy;
3126 struct policydb *policydb;
3127 int rc;
3128 u32 len;
3129
3130 if (!selinux_initialized())
3131 return 0;
3132
3133 rcu_read_lock();
3134 policy = rcu_dereference(selinux_state.policy);
3135 policydb = &policy->policydb;
3136
3137 rc = -EFAULT;
3138 len = policydb->p_bools.nprim;
3139 if (index >= len)
3140 goto out;
3141
3142 rc = policydb->bool_val_to_struct[index]->state;
3143out:
3144 rcu_read_unlock();
3145 return rc;
3146}
3147
3148static int security_preserve_bools(struct selinux_policy *oldpolicy,
3149 struct selinux_policy *newpolicy)
3150{
3151 int rc, *bvalues = NULL;
3152 char **bnames = NULL;
3153 struct cond_bool_datum *booldatum;
3154 u32 i, nbools = 0;
3155
3156 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3157 if (rc)
3158 goto out;
3159 for (i = 0; i < nbools; i++) {
3160 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3161 bnames[i]);
3162 if (booldatum)
3163 booldatum->state = bvalues[i];
3164 }
3165 evaluate_cond_nodes(&newpolicy->policydb);
3166
3167out:
3168 if (bnames) {
3169 for (i = 0; i < nbools; i++)
3170 kfree(bnames[i]);
3171 }
3172 kfree(bnames);
3173 kfree(bvalues);
3174 return rc;
3175}
3176
3177/*
3178 * security_sid_mls_copy() - computes a new sid based on the given
3179 * sid and the mls portion of mls_sid.
3180 */
3181int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
3182{
3183 struct selinux_policy *policy;
3184 struct policydb *policydb;
3185 struct sidtab *sidtab;
3186 struct context *context1;
3187 struct context *context2;
3188 struct context newcon;
3189 char *s;
3190 u32 len;
3191 int rc;
3192
3193 if (!selinux_initialized()) {
3194 *new_sid = sid;
3195 return 0;
3196 }
3197
3198retry:
3199 rc = 0;
3200 context_init(&newcon);
3201
3202 rcu_read_lock();
3203 policy = rcu_dereference(selinux_state.policy);
3204 policydb = &policy->policydb;
3205 sidtab = policy->sidtab;
3206
3207 if (!policydb->mls_enabled) {
3208 *new_sid = sid;
3209 goto out_unlock;
3210 }
3211
3212 rc = -EINVAL;
3213 context1 = sidtab_search(sidtab, sid);
3214 if (!context1) {
3215 pr_err("SELinux: %s: unrecognized SID %d\n",
3216 __func__, sid);
3217 goto out_unlock;
3218 }
3219
3220 rc = -EINVAL;
3221 context2 = sidtab_search(sidtab, mls_sid);
3222 if (!context2) {
3223 pr_err("SELinux: %s: unrecognized SID %d\n",
3224 __func__, mls_sid);
3225 goto out_unlock;
3226 }
3227
3228 newcon.user = context1->user;
3229 newcon.role = context1->role;
3230 newcon.type = context1->type;
3231 rc = mls_context_cpy(&newcon, context2);
3232 if (rc)
3233 goto out_unlock;
3234
3235 /* Check the validity of the new context. */
3236 if (!policydb_context_isvalid(policydb, &newcon)) {
3237 rc = convert_context_handle_invalid_context(policydb,
3238 &newcon);
3239 if (rc) {
3240 if (!context_struct_to_string(policydb, &newcon, &s,
3241 &len)) {
3242 struct audit_buffer *ab;
3243
3244 ab = audit_log_start(audit_context(),
3245 GFP_ATOMIC,
3246 AUDIT_SELINUX_ERR);
3247 audit_log_format(ab,
3248 "op=security_sid_mls_copy invalid_context=");
3249 /* don't record NUL with untrusted strings */
3250 audit_log_n_untrustedstring(ab, s, len - 1);
3251 audit_log_end(ab);
3252 kfree(s);
3253 }
3254 goto out_unlock;
3255 }
3256 }
3257 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3258 if (rc == -ESTALE) {
3259 rcu_read_unlock();
3260 context_destroy(&newcon);
3261 goto retry;
3262 }
3263out_unlock:
3264 rcu_read_unlock();
3265 context_destroy(&newcon);
3266 return rc;
3267}
3268
3269/**
3270 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3271 * @nlbl_sid: NetLabel SID
3272 * @nlbl_type: NetLabel labeling protocol type
3273 * @xfrm_sid: XFRM SID
3274 * @peer_sid: network peer sid
3275 *
3276 * Description:
3277 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3278 * resolved into a single SID it is returned via @peer_sid and the function
3279 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
3280 * returns a negative value. A table summarizing the behavior is below:
3281 *
3282 * | function return | @sid
3283 * ------------------------------+-----------------+-----------------
3284 * no peer labels | 0 | SECSID_NULL
3285 * single peer label | 0 | <peer_label>
3286 * multiple, consistent labels | 0 | <peer_label>
3287 * multiple, inconsistent labels | -<errno> | SECSID_NULL
3288 *
3289 */
3290int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
3291 u32 xfrm_sid,
3292 u32 *peer_sid)
3293{
3294 struct selinux_policy *policy;
3295 struct policydb *policydb;
3296 struct sidtab *sidtab;
3297 int rc;
3298 struct context *nlbl_ctx;
3299 struct context *xfrm_ctx;
3300
3301 *peer_sid = SECSID_NULL;
3302
3303 /* handle the common (which also happens to be the set of easy) cases
3304 * right away, these two if statements catch everything involving a
3305 * single or absent peer SID/label */
3306 if (xfrm_sid == SECSID_NULL) {
3307 *peer_sid = nlbl_sid;
3308 return 0;
3309 }
3310 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3311 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3312 * is present */
3313 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3314 *peer_sid = xfrm_sid;
3315 return 0;
3316 }
3317
3318 if (!selinux_initialized())
3319 return 0;
3320
3321 rcu_read_lock();
3322 policy = rcu_dereference(selinux_state.policy);
3323 policydb = &policy->policydb;
3324 sidtab = policy->sidtab;
3325
3326 /*
3327 * We don't need to check initialized here since the only way both
3328 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3329 * security server was initialized and state->initialized was true.
3330 */
3331 if (!policydb->mls_enabled) {
3332 rc = 0;
3333 goto out;
3334 }
3335
3336 rc = -EINVAL;
3337 nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3338 if (!nlbl_ctx) {
3339 pr_err("SELinux: %s: unrecognized SID %d\n",
3340 __func__, nlbl_sid);
3341 goto out;
3342 }
3343 rc = -EINVAL;
3344 xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3345 if (!xfrm_ctx) {
3346 pr_err("SELinux: %s: unrecognized SID %d\n",
3347 __func__, xfrm_sid);
3348 goto out;
3349 }
3350 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3351 if (rc)
3352 goto out;
3353
3354 /* at present NetLabel SIDs/labels really only carry MLS
3355 * information so if the MLS portion of the NetLabel SID
3356 * matches the MLS portion of the labeled XFRM SID/label
3357 * then pass along the XFRM SID as it is the most
3358 * expressive */
3359 *peer_sid = xfrm_sid;
3360out:
3361 rcu_read_unlock();
3362 return rc;
3363}
3364
3365static int get_classes_callback(void *k, void *d, void *args)
3366{
3367 struct class_datum *datum = d;
3368 char *name = k, **classes = args;
3369 u32 value = datum->value - 1;
3370
3371 classes[value] = kstrdup(name, GFP_ATOMIC);
3372 if (!classes[value])
3373 return -ENOMEM;
3374
3375 return 0;
3376}
3377
3378int security_get_classes(struct selinux_policy *policy,
3379 char ***classes, u32 *nclasses)
3380{
3381 struct policydb *policydb;
3382 int rc;
3383
3384 policydb = &policy->policydb;
3385
3386 rc = -ENOMEM;
3387 *nclasses = policydb->p_classes.nprim;
3388 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3389 if (!*classes)
3390 goto out;
3391
3392 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3393 *classes);
3394 if (rc) {
3395 u32 i;
3396
3397 for (i = 0; i < *nclasses; i++)
3398 kfree((*classes)[i]);
3399 kfree(*classes);
3400 }
3401
3402out:
3403 return rc;
3404}
3405
3406static int get_permissions_callback(void *k, void *d, void *args)
3407{
3408 struct perm_datum *datum = d;
3409 char *name = k, **perms = args;
3410 u32 value = datum->value - 1;
3411
3412 perms[value] = kstrdup(name, GFP_ATOMIC);
3413 if (!perms[value])
3414 return -ENOMEM;
3415
3416 return 0;
3417}
3418
3419int security_get_permissions(struct selinux_policy *policy,
3420 const char *class, char ***perms, u32 *nperms)
3421{
3422 struct policydb *policydb;
3423 u32 i;
3424 int rc;
3425 struct class_datum *match;
3426
3427 policydb = &policy->policydb;
3428
3429 rc = -EINVAL;
3430 match = symtab_search(&policydb->p_classes, class);
3431 if (!match) {
3432 pr_err("SELinux: %s: unrecognized class %s\n",
3433 __func__, class);
3434 goto out;
3435 }
3436
3437 rc = -ENOMEM;
3438 *nperms = match->permissions.nprim;
3439 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3440 if (!*perms)
3441 goto out;
3442
3443 if (match->comdatum) {
3444 rc = hashtab_map(&match->comdatum->permissions.table,
3445 get_permissions_callback, *perms);
3446 if (rc)
3447 goto err;
3448 }
3449
3450 rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3451 *perms);
3452 if (rc)
3453 goto err;
3454
3455out:
3456 return rc;
3457
3458err:
3459 for (i = 0; i < *nperms; i++)
3460 kfree((*perms)[i]);
3461 kfree(*perms);
3462 return rc;
3463}
3464
3465int security_get_reject_unknown(void)
3466{
3467 struct selinux_policy *policy;
3468 int value;
3469
3470 if (!selinux_initialized())
3471 return 0;
3472
3473 rcu_read_lock();
3474 policy = rcu_dereference(selinux_state.policy);
3475 value = policy->policydb.reject_unknown;
3476 rcu_read_unlock();
3477 return value;
3478}
3479
3480int security_get_allow_unknown(void)
3481{
3482 struct selinux_policy *policy;
3483 int value;
3484
3485 if (!selinux_initialized())
3486 return 0;
3487
3488 rcu_read_lock();
3489 policy = rcu_dereference(selinux_state.policy);
3490 value = policy->policydb.allow_unknown;
3491 rcu_read_unlock();
3492 return value;
3493}
3494
3495/**
3496 * security_policycap_supported - Check for a specific policy capability
3497 * @req_cap: capability
3498 *
3499 * Description:
3500 * This function queries the currently loaded policy to see if it supports the
3501 * capability specified by @req_cap. Returns true (1) if the capability is
3502 * supported, false (0) if it isn't supported.
3503 *
3504 */
3505int security_policycap_supported(unsigned int req_cap)
3506{
3507 struct selinux_policy *policy;
3508 int rc;
3509
3510 if (!selinux_initialized())
3511 return 0;
3512
3513 rcu_read_lock();
3514 policy = rcu_dereference(selinux_state.policy);
3515 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3516 rcu_read_unlock();
3517
3518 return rc;
3519}
3520
3521struct selinux_audit_rule {
3522 u32 au_seqno;
3523 struct context au_ctxt;
3524};
3525
3526void selinux_audit_rule_free(void *vrule)
3527{
3528 struct selinux_audit_rule *rule = vrule;
3529
3530 if (rule) {
3531 context_destroy(&rule->au_ctxt);
3532 kfree(rule);
3533 }
3534}
3535
3536int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule,
3537 gfp_t gfp)
3538{
3539 struct selinux_state *state = &selinux_state;
3540 struct selinux_policy *policy;
3541 struct policydb *policydb;
3542 struct selinux_audit_rule *tmprule;
3543 struct role_datum *roledatum;
3544 struct type_datum *typedatum;
3545 struct user_datum *userdatum;
3546 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3547 int rc = 0;
3548
3549 *rule = NULL;
3550
3551 if (!selinux_initialized())
3552 return -EOPNOTSUPP;
3553
3554 switch (field) {
3555 case AUDIT_SUBJ_USER:
3556 case AUDIT_SUBJ_ROLE:
3557 case AUDIT_SUBJ_TYPE:
3558 case AUDIT_OBJ_USER:
3559 case AUDIT_OBJ_ROLE:
3560 case AUDIT_OBJ_TYPE:
3561 /* only 'equals' and 'not equals' fit user, role, and type */
3562 if (op != Audit_equal && op != Audit_not_equal)
3563 return -EINVAL;
3564 break;
3565 case AUDIT_SUBJ_SEN:
3566 case AUDIT_SUBJ_CLR:
3567 case AUDIT_OBJ_LEV_LOW:
3568 case AUDIT_OBJ_LEV_HIGH:
3569 /* we do not allow a range, indicated by the presence of '-' */
3570 if (strchr(rulestr, '-'))
3571 return -EINVAL;
3572 break;
3573 default:
3574 /* only the above fields are valid */
3575 return -EINVAL;
3576 }
3577
3578 tmprule = kzalloc(sizeof(struct selinux_audit_rule), gfp);
3579 if (!tmprule)
3580 return -ENOMEM;
3581 context_init(&tmprule->au_ctxt);
3582
3583 rcu_read_lock();
3584 policy = rcu_dereference(state->policy);
3585 policydb = &policy->policydb;
3586 tmprule->au_seqno = policy->latest_granting;
3587 switch (field) {
3588 case AUDIT_SUBJ_USER:
3589 case AUDIT_OBJ_USER:
3590 userdatum = symtab_search(&policydb->p_users, rulestr);
3591 if (!userdatum) {
3592 rc = -EINVAL;
3593 goto err;
3594 }
3595 tmprule->au_ctxt.user = userdatum->value;
3596 break;
3597 case AUDIT_SUBJ_ROLE:
3598 case AUDIT_OBJ_ROLE:
3599 roledatum = symtab_search(&policydb->p_roles, rulestr);
3600 if (!roledatum) {
3601 rc = -EINVAL;
3602 goto err;
3603 }
3604 tmprule->au_ctxt.role = roledatum->value;
3605 break;
3606 case AUDIT_SUBJ_TYPE:
3607 case AUDIT_OBJ_TYPE:
3608 typedatum = symtab_search(&policydb->p_types, rulestr);
3609 if (!typedatum) {
3610 rc = -EINVAL;
3611 goto err;
3612 }
3613 tmprule->au_ctxt.type = typedatum->value;
3614 break;
3615 case AUDIT_SUBJ_SEN:
3616 case AUDIT_SUBJ_CLR:
3617 case AUDIT_OBJ_LEV_LOW:
3618 case AUDIT_OBJ_LEV_HIGH:
3619 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3620 GFP_ATOMIC);
3621 if (rc)
3622 goto err;
3623 break;
3624 }
3625 rcu_read_unlock();
3626
3627 *rule = tmprule;
3628 return 0;
3629
3630err:
3631 rcu_read_unlock();
3632 selinux_audit_rule_free(tmprule);
3633 *rule = NULL;
3634 return rc;
3635}
3636
3637/* Check to see if the rule contains any selinux fields */
3638int selinux_audit_rule_known(struct audit_krule *rule)
3639{
3640 u32 i;
3641
3642 for (i = 0; i < rule->field_count; i++) {
3643 struct audit_field *f = &rule->fields[i];
3644 switch (f->type) {
3645 case AUDIT_SUBJ_USER:
3646 case AUDIT_SUBJ_ROLE:
3647 case AUDIT_SUBJ_TYPE:
3648 case AUDIT_SUBJ_SEN:
3649 case AUDIT_SUBJ_CLR:
3650 case AUDIT_OBJ_USER:
3651 case AUDIT_OBJ_ROLE:
3652 case AUDIT_OBJ_TYPE:
3653 case AUDIT_OBJ_LEV_LOW:
3654 case AUDIT_OBJ_LEV_HIGH:
3655 return 1;
3656 }
3657 }
3658
3659 return 0;
3660}
3661
3662int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule)
3663{
3664 struct selinux_state *state = &selinux_state;
3665 struct selinux_policy *policy;
3666 struct context *ctxt;
3667 struct mls_level *level;
3668 struct selinux_audit_rule *rule = vrule;
3669 int match = 0;
3670
3671 if (unlikely(!rule)) {
3672 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3673 return -ENOENT;
3674 }
3675
3676 if (!selinux_initialized())
3677 return 0;
3678
3679 rcu_read_lock();
3680
3681 policy = rcu_dereference(state->policy);
3682
3683 if (rule->au_seqno < policy->latest_granting) {
3684 match = -ESTALE;
3685 goto out;
3686 }
3687
3688 ctxt = sidtab_search(policy->sidtab, prop->selinux.secid);
3689 if (unlikely(!ctxt)) {
3690 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3691 prop->selinux.secid);
3692 match = -ENOENT;
3693 goto out;
3694 }
3695
3696 /* a field/op pair that is not caught here will simply fall through
3697 without a match */
3698 switch (field) {
3699 case AUDIT_SUBJ_USER:
3700 case AUDIT_OBJ_USER:
3701 switch (op) {
3702 case Audit_equal:
3703 match = (ctxt->user == rule->au_ctxt.user);
3704 break;
3705 case Audit_not_equal:
3706 match = (ctxt->user != rule->au_ctxt.user);
3707 break;
3708 }
3709 break;
3710 case AUDIT_SUBJ_ROLE:
3711 case AUDIT_OBJ_ROLE:
3712 switch (op) {
3713 case Audit_equal:
3714 match = (ctxt->role == rule->au_ctxt.role);
3715 break;
3716 case Audit_not_equal:
3717 match = (ctxt->role != rule->au_ctxt.role);
3718 break;
3719 }
3720 break;
3721 case AUDIT_SUBJ_TYPE:
3722 case AUDIT_OBJ_TYPE:
3723 switch (op) {
3724 case Audit_equal:
3725 match = (ctxt->type == rule->au_ctxt.type);
3726 break;
3727 case Audit_not_equal:
3728 match = (ctxt->type != rule->au_ctxt.type);
3729 break;
3730 }
3731 break;
3732 case AUDIT_SUBJ_SEN:
3733 case AUDIT_SUBJ_CLR:
3734 case AUDIT_OBJ_LEV_LOW:
3735 case AUDIT_OBJ_LEV_HIGH:
3736 level = ((field == AUDIT_SUBJ_SEN ||
3737 field == AUDIT_OBJ_LEV_LOW) ?
3738 &ctxt->range.level[0] : &ctxt->range.level[1]);
3739 switch (op) {
3740 case Audit_equal:
3741 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3742 level);
3743 break;
3744 case Audit_not_equal:
3745 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3746 level);
3747 break;
3748 case Audit_lt:
3749 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3750 level) &&
3751 !mls_level_eq(&rule->au_ctxt.range.level[0],
3752 level));
3753 break;
3754 case Audit_le:
3755 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3756 level);
3757 break;
3758 case Audit_gt:
3759 match = (mls_level_dom(level,
3760 &rule->au_ctxt.range.level[0]) &&
3761 !mls_level_eq(level,
3762 &rule->au_ctxt.range.level[0]));
3763 break;
3764 case Audit_ge:
3765 match = mls_level_dom(level,
3766 &rule->au_ctxt.range.level[0]);
3767 break;
3768 }
3769 }
3770
3771out:
3772 rcu_read_unlock();
3773 return match;
3774}
3775
3776static int aurule_avc_callback(u32 event)
3777{
3778 if (event == AVC_CALLBACK_RESET)
3779 return audit_update_lsm_rules();
3780 return 0;
3781}
3782
3783static int __init aurule_init(void)
3784{
3785 int err;
3786
3787 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3788 if (err)
3789 panic("avc_add_callback() failed, error %d\n", err);
3790
3791 return err;
3792}
3793__initcall(aurule_init);
3794
3795#ifdef CONFIG_NETLABEL
3796/**
3797 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3798 * @secattr: the NetLabel packet security attributes
3799 * @sid: the SELinux SID
3800 *
3801 * Description:
3802 * Attempt to cache the context in @ctx, which was derived from the packet in
3803 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3804 * already been initialized.
3805 *
3806 */
3807static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3808 u32 sid)
3809{
3810 u32 *sid_cache;
3811
3812 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3813 if (sid_cache == NULL)
3814 return;
3815 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3816 if (secattr->cache == NULL) {
3817 kfree(sid_cache);
3818 return;
3819 }
3820
3821 *sid_cache = sid;
3822 secattr->cache->free = kfree;
3823 secattr->cache->data = sid_cache;
3824 secattr->flags |= NETLBL_SECATTR_CACHE;
3825}
3826
3827/**
3828 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3829 * @secattr: the NetLabel packet security attributes
3830 * @sid: the SELinux SID
3831 *
3832 * Description:
3833 * Convert the given NetLabel security attributes in @secattr into a
3834 * SELinux SID. If the @secattr field does not contain a full SELinux
3835 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3836 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3837 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3838 * conversion for future lookups. Returns zero on success, negative values on
3839 * failure.
3840 *
3841 */
3842int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3843 u32 *sid)
3844{
3845 struct selinux_policy *policy;
3846 struct policydb *policydb;
3847 struct sidtab *sidtab;
3848 int rc;
3849 struct context *ctx;
3850 struct context ctx_new;
3851
3852 if (!selinux_initialized()) {
3853 *sid = SECSID_NULL;
3854 return 0;
3855 }
3856
3857retry:
3858 rc = 0;
3859 rcu_read_lock();
3860 policy = rcu_dereference(selinux_state.policy);
3861 policydb = &policy->policydb;
3862 sidtab = policy->sidtab;
3863
3864 if (secattr->flags & NETLBL_SECATTR_CACHE)
3865 *sid = *(u32 *)secattr->cache->data;
3866 else if (secattr->flags & NETLBL_SECATTR_SECID)
3867 *sid = secattr->attr.secid;
3868 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3869 rc = -EIDRM;
3870 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3871 if (ctx == NULL)
3872 goto out;
3873
3874 context_init(&ctx_new);
3875 ctx_new.user = ctx->user;
3876 ctx_new.role = ctx->role;
3877 ctx_new.type = ctx->type;
3878 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3879 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3880 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3881 if (rc)
3882 goto out;
3883 }
3884 rc = -EIDRM;
3885 if (!mls_context_isvalid(policydb, &ctx_new)) {
3886 ebitmap_destroy(&ctx_new.range.level[0].cat);
3887 goto out;
3888 }
3889
3890 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3891 ebitmap_destroy(&ctx_new.range.level[0].cat);
3892 if (rc == -ESTALE) {
3893 rcu_read_unlock();
3894 goto retry;
3895 }
3896 if (rc)
3897 goto out;
3898
3899 security_netlbl_cache_add(secattr, *sid);
3900 } else
3901 *sid = SECSID_NULL;
3902
3903out:
3904 rcu_read_unlock();
3905 return rc;
3906}
3907
3908/**
3909 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3910 * @sid: the SELinux SID
3911 * @secattr: the NetLabel packet security attributes
3912 *
3913 * Description:
3914 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3915 * Returns zero on success, negative values on failure.
3916 *
3917 */
3918int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3919{
3920 struct selinux_policy *policy;
3921 struct policydb *policydb;
3922 int rc;
3923 struct context *ctx;
3924
3925 if (!selinux_initialized())
3926 return 0;
3927
3928 rcu_read_lock();
3929 policy = rcu_dereference(selinux_state.policy);
3930 policydb = &policy->policydb;
3931
3932 rc = -ENOENT;
3933 ctx = sidtab_search(policy->sidtab, sid);
3934 if (ctx == NULL)
3935 goto out;
3936
3937 rc = -ENOMEM;
3938 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3939 GFP_ATOMIC);
3940 if (secattr->domain == NULL)
3941 goto out;
3942
3943 secattr->attr.secid = sid;
3944 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3945 mls_export_netlbl_lvl(policydb, ctx, secattr);
3946 rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3947out:
3948 rcu_read_unlock();
3949 return rc;
3950}
3951#endif /* CONFIG_NETLABEL */
3952
3953/**
3954 * __security_read_policy - read the policy.
3955 * @policy: SELinux policy
3956 * @data: binary policy data
3957 * @len: length of data in bytes
3958 *
3959 */
3960static int __security_read_policy(struct selinux_policy *policy,
3961 void *data, size_t *len)
3962{
3963 int rc;
3964 struct policy_file fp;
3965
3966 fp.data = data;
3967 fp.len = *len;
3968
3969 rc = policydb_write(&policy->policydb, &fp);
3970 if (rc)
3971 return rc;
3972
3973 *len = (unsigned long)fp.data - (unsigned long)data;
3974 return 0;
3975}
3976
3977/**
3978 * security_read_policy - read the policy.
3979 * @data: binary policy data
3980 * @len: length of data in bytes
3981 *
3982 */
3983int security_read_policy(void **data, size_t *len)
3984{
3985 struct selinux_state *state = &selinux_state;
3986 struct selinux_policy *policy;
3987
3988 policy = rcu_dereference_protected(
3989 state->policy, lockdep_is_held(&state->policy_mutex));
3990 if (!policy)
3991 return -EINVAL;
3992
3993 *len = policy->policydb.len;
3994 *data = vmalloc_user(*len);
3995 if (!*data)
3996 return -ENOMEM;
3997
3998 return __security_read_policy(policy, *data, len);
3999}
4000
4001/**
4002 * security_read_state_kernel - read the policy.
4003 * @data: binary policy data
4004 * @len: length of data in bytes
4005 *
4006 * Allocates kernel memory for reading SELinux policy.
4007 * This function is for internal use only and should not
4008 * be used for returning data to user space.
4009 *
4010 * This function must be called with policy_mutex held.
4011 */
4012int security_read_state_kernel(void **data, size_t *len)
4013{
4014 int err;
4015 struct selinux_state *state = &selinux_state;
4016 struct selinux_policy *policy;
4017
4018 policy = rcu_dereference_protected(
4019 state->policy, lockdep_is_held(&state->policy_mutex));
4020 if (!policy)
4021 return -EINVAL;
4022
4023 *len = policy->policydb.len;
4024 *data = vmalloc(*len);
4025 if (!*data)
4026 return -ENOMEM;
4027
4028 err = __security_read_policy(policy, *data, len);
4029 if (err) {
4030 vfree(*data);
4031 *data = NULL;
4032 *len = 0;
4033 }
4034 return err;
4035}
1/*
2 * Implementation of the security services.
3 *
4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5 * James Morris <jmorris@redhat.com>
6 *
7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8 *
9 * Support for enhanced MLS infrastructure.
10 * Support for context based audit filters.
11 *
12 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13 *
14 * Added conditional policy language extensions
15 *
16 * Updated: Hewlett-Packard <paul@paul-moore.com>
17 *
18 * Added support for NetLabel
19 * Added support for the policy capability bitmap
20 *
21 * Updated: Chad Sellers <csellers@tresys.com>
22 *
23 * Added validation of kernel classes and permissions
24 *
25 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26 *
27 * Added support for bounds domain and audit messaged on masked permissions
28 *
29 * Updated: Guido Trentalancia <guido@trentalancia.com>
30 *
31 * Added support for runtime switching of the policy type
32 *
33 * Copyright (C) 2008, 2009 NEC Corporation
34 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38 * This program is free software; you can redistribute it and/or modify
39 * it under the terms of the GNU General Public License as published by
40 * the Free Software Foundation, version 2.
41 */
42#include <linux/kernel.h>
43#include <linux/slab.h>
44#include <linux/string.h>
45#include <linux/spinlock.h>
46#include <linux/rcupdate.h>
47#include <linux/errno.h>
48#include <linux/in.h>
49#include <linux/sched.h>
50#include <linux/audit.h>
51#include <linux/mutex.h>
52#include <linux/selinux.h>
53#include <linux/flex_array.h>
54#include <linux/vmalloc.h>
55#include <net/netlabel.h>
56
57#include "flask.h"
58#include "avc.h"
59#include "avc_ss.h"
60#include "security.h"
61#include "context.h"
62#include "policydb.h"
63#include "sidtab.h"
64#include "services.h"
65#include "conditional.h"
66#include "mls.h"
67#include "objsec.h"
68#include "netlabel.h"
69#include "xfrm.h"
70#include "ebitmap.h"
71#include "audit.h"
72
73int selinux_policycap_netpeer;
74int selinux_policycap_openperm;
75int selinux_policycap_alwaysnetwork;
76
77static DEFINE_RWLOCK(policy_rwlock);
78
79static struct sidtab sidtab;
80struct policydb policydb;
81int ss_initialized;
82
83/*
84 * The largest sequence number that has been used when
85 * providing an access decision to the access vector cache.
86 * The sequence number only changes when a policy change
87 * occurs.
88 */
89static u32 latest_granting;
90
91/* Forward declaration. */
92static int context_struct_to_string(struct context *context, char **scontext,
93 u32 *scontext_len);
94
95static void context_struct_compute_av(struct context *scontext,
96 struct context *tcontext,
97 u16 tclass,
98 struct av_decision *avd);
99
100struct selinux_mapping {
101 u16 value; /* policy value */
102 unsigned num_perms;
103 u32 perms[sizeof(u32) * 8];
104};
105
106static struct selinux_mapping *current_mapping;
107static u16 current_mapping_size;
108
109static int selinux_set_mapping(struct policydb *pol,
110 struct security_class_mapping *map,
111 struct selinux_mapping **out_map_p,
112 u16 *out_map_size)
113{
114 struct selinux_mapping *out_map = NULL;
115 size_t size = sizeof(struct selinux_mapping);
116 u16 i, j;
117 unsigned k;
118 bool print_unknown_handle = false;
119
120 /* Find number of classes in the input mapping */
121 if (!map)
122 return -EINVAL;
123 i = 0;
124 while (map[i].name)
125 i++;
126
127 /* Allocate space for the class records, plus one for class zero */
128 out_map = kcalloc(++i, size, GFP_ATOMIC);
129 if (!out_map)
130 return -ENOMEM;
131
132 /* Store the raw class and permission values */
133 j = 0;
134 while (map[j].name) {
135 struct security_class_mapping *p_in = map + (j++);
136 struct selinux_mapping *p_out = out_map + j;
137
138 /* An empty class string skips ahead */
139 if (!strcmp(p_in->name, "")) {
140 p_out->num_perms = 0;
141 continue;
142 }
143
144 p_out->value = string_to_security_class(pol, p_in->name);
145 if (!p_out->value) {
146 printk(KERN_INFO
147 "SELinux: Class %s not defined in policy.\n",
148 p_in->name);
149 if (pol->reject_unknown)
150 goto err;
151 p_out->num_perms = 0;
152 print_unknown_handle = true;
153 continue;
154 }
155
156 k = 0;
157 while (p_in->perms && p_in->perms[k]) {
158 /* An empty permission string skips ahead */
159 if (!*p_in->perms[k]) {
160 k++;
161 continue;
162 }
163 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
164 p_in->perms[k]);
165 if (!p_out->perms[k]) {
166 printk(KERN_INFO
167 "SELinux: Permission %s in class %s not defined in policy.\n",
168 p_in->perms[k], p_in->name);
169 if (pol->reject_unknown)
170 goto err;
171 print_unknown_handle = true;
172 }
173
174 k++;
175 }
176 p_out->num_perms = k;
177 }
178
179 if (print_unknown_handle)
180 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
181 pol->allow_unknown ? "allowed" : "denied");
182
183 *out_map_p = out_map;
184 *out_map_size = i;
185 return 0;
186err:
187 kfree(out_map);
188 return -EINVAL;
189}
190
191/*
192 * Get real, policy values from mapped values
193 */
194
195static u16 unmap_class(u16 tclass)
196{
197 if (tclass < current_mapping_size)
198 return current_mapping[tclass].value;
199
200 return tclass;
201}
202
203/*
204 * Get kernel value for class from its policy value
205 */
206static u16 map_class(u16 pol_value)
207{
208 u16 i;
209
210 for (i = 1; i < current_mapping_size; i++) {
211 if (current_mapping[i].value == pol_value)
212 return i;
213 }
214
215 return SECCLASS_NULL;
216}
217
218static void map_decision(u16 tclass, struct av_decision *avd,
219 int allow_unknown)
220{
221 if (tclass < current_mapping_size) {
222 unsigned i, n = current_mapping[tclass].num_perms;
223 u32 result;
224
225 for (i = 0, result = 0; i < n; i++) {
226 if (avd->allowed & current_mapping[tclass].perms[i])
227 result |= 1<<i;
228 if (allow_unknown && !current_mapping[tclass].perms[i])
229 result |= 1<<i;
230 }
231 avd->allowed = result;
232
233 for (i = 0, result = 0; i < n; i++)
234 if (avd->auditallow & current_mapping[tclass].perms[i])
235 result |= 1<<i;
236 avd->auditallow = result;
237
238 for (i = 0, result = 0; i < n; i++) {
239 if (avd->auditdeny & current_mapping[tclass].perms[i])
240 result |= 1<<i;
241 if (!allow_unknown && !current_mapping[tclass].perms[i])
242 result |= 1<<i;
243 }
244 /*
245 * In case the kernel has a bug and requests a permission
246 * between num_perms and the maximum permission number, we
247 * should audit that denial
248 */
249 for (; i < (sizeof(u32)*8); i++)
250 result |= 1<<i;
251 avd->auditdeny = result;
252 }
253}
254
255int security_mls_enabled(void)
256{
257 return policydb.mls_enabled;
258}
259
260/*
261 * Return the boolean value of a constraint expression
262 * when it is applied to the specified source and target
263 * security contexts.
264 *
265 * xcontext is a special beast... It is used by the validatetrans rules
266 * only. For these rules, scontext is the context before the transition,
267 * tcontext is the context after the transition, and xcontext is the context
268 * of the process performing the transition. All other callers of
269 * constraint_expr_eval should pass in NULL for xcontext.
270 */
271static int constraint_expr_eval(struct context *scontext,
272 struct context *tcontext,
273 struct context *xcontext,
274 struct constraint_expr *cexpr)
275{
276 u32 val1, val2;
277 struct context *c;
278 struct role_datum *r1, *r2;
279 struct mls_level *l1, *l2;
280 struct constraint_expr *e;
281 int s[CEXPR_MAXDEPTH];
282 int sp = -1;
283
284 for (e = cexpr; e; e = e->next) {
285 switch (e->expr_type) {
286 case CEXPR_NOT:
287 BUG_ON(sp < 0);
288 s[sp] = !s[sp];
289 break;
290 case CEXPR_AND:
291 BUG_ON(sp < 1);
292 sp--;
293 s[sp] &= s[sp + 1];
294 break;
295 case CEXPR_OR:
296 BUG_ON(sp < 1);
297 sp--;
298 s[sp] |= s[sp + 1];
299 break;
300 case CEXPR_ATTR:
301 if (sp == (CEXPR_MAXDEPTH - 1))
302 return 0;
303 switch (e->attr) {
304 case CEXPR_USER:
305 val1 = scontext->user;
306 val2 = tcontext->user;
307 break;
308 case CEXPR_TYPE:
309 val1 = scontext->type;
310 val2 = tcontext->type;
311 break;
312 case CEXPR_ROLE:
313 val1 = scontext->role;
314 val2 = tcontext->role;
315 r1 = policydb.role_val_to_struct[val1 - 1];
316 r2 = policydb.role_val_to_struct[val2 - 1];
317 switch (e->op) {
318 case CEXPR_DOM:
319 s[++sp] = ebitmap_get_bit(&r1->dominates,
320 val2 - 1);
321 continue;
322 case CEXPR_DOMBY:
323 s[++sp] = ebitmap_get_bit(&r2->dominates,
324 val1 - 1);
325 continue;
326 case CEXPR_INCOMP:
327 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
328 val2 - 1) &&
329 !ebitmap_get_bit(&r2->dominates,
330 val1 - 1));
331 continue;
332 default:
333 break;
334 }
335 break;
336 case CEXPR_L1L2:
337 l1 = &(scontext->range.level[0]);
338 l2 = &(tcontext->range.level[0]);
339 goto mls_ops;
340 case CEXPR_L1H2:
341 l1 = &(scontext->range.level[0]);
342 l2 = &(tcontext->range.level[1]);
343 goto mls_ops;
344 case CEXPR_H1L2:
345 l1 = &(scontext->range.level[1]);
346 l2 = &(tcontext->range.level[0]);
347 goto mls_ops;
348 case CEXPR_H1H2:
349 l1 = &(scontext->range.level[1]);
350 l2 = &(tcontext->range.level[1]);
351 goto mls_ops;
352 case CEXPR_L1H1:
353 l1 = &(scontext->range.level[0]);
354 l2 = &(scontext->range.level[1]);
355 goto mls_ops;
356 case CEXPR_L2H2:
357 l1 = &(tcontext->range.level[0]);
358 l2 = &(tcontext->range.level[1]);
359 goto mls_ops;
360mls_ops:
361 switch (e->op) {
362 case CEXPR_EQ:
363 s[++sp] = mls_level_eq(l1, l2);
364 continue;
365 case CEXPR_NEQ:
366 s[++sp] = !mls_level_eq(l1, l2);
367 continue;
368 case CEXPR_DOM:
369 s[++sp] = mls_level_dom(l1, l2);
370 continue;
371 case CEXPR_DOMBY:
372 s[++sp] = mls_level_dom(l2, l1);
373 continue;
374 case CEXPR_INCOMP:
375 s[++sp] = mls_level_incomp(l2, l1);
376 continue;
377 default:
378 BUG();
379 return 0;
380 }
381 break;
382 default:
383 BUG();
384 return 0;
385 }
386
387 switch (e->op) {
388 case CEXPR_EQ:
389 s[++sp] = (val1 == val2);
390 break;
391 case CEXPR_NEQ:
392 s[++sp] = (val1 != val2);
393 break;
394 default:
395 BUG();
396 return 0;
397 }
398 break;
399 case CEXPR_NAMES:
400 if (sp == (CEXPR_MAXDEPTH-1))
401 return 0;
402 c = scontext;
403 if (e->attr & CEXPR_TARGET)
404 c = tcontext;
405 else if (e->attr & CEXPR_XTARGET) {
406 c = xcontext;
407 if (!c) {
408 BUG();
409 return 0;
410 }
411 }
412 if (e->attr & CEXPR_USER)
413 val1 = c->user;
414 else if (e->attr & CEXPR_ROLE)
415 val1 = c->role;
416 else if (e->attr & CEXPR_TYPE)
417 val1 = c->type;
418 else {
419 BUG();
420 return 0;
421 }
422
423 switch (e->op) {
424 case CEXPR_EQ:
425 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
426 break;
427 case CEXPR_NEQ:
428 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
429 break;
430 default:
431 BUG();
432 return 0;
433 }
434 break;
435 default:
436 BUG();
437 return 0;
438 }
439 }
440
441 BUG_ON(sp != 0);
442 return s[0];
443}
444
445/*
446 * security_dump_masked_av - dumps masked permissions during
447 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
448 */
449static int dump_masked_av_helper(void *k, void *d, void *args)
450{
451 struct perm_datum *pdatum = d;
452 char **permission_names = args;
453
454 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
455
456 permission_names[pdatum->value - 1] = (char *)k;
457
458 return 0;
459}
460
461static void security_dump_masked_av(struct context *scontext,
462 struct context *tcontext,
463 u16 tclass,
464 u32 permissions,
465 const char *reason)
466{
467 struct common_datum *common_dat;
468 struct class_datum *tclass_dat;
469 struct audit_buffer *ab;
470 char *tclass_name;
471 char *scontext_name = NULL;
472 char *tcontext_name = NULL;
473 char *permission_names[32];
474 int index;
475 u32 length;
476 bool need_comma = false;
477
478 if (!permissions)
479 return;
480
481 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
482 tclass_dat = policydb.class_val_to_struct[tclass - 1];
483 common_dat = tclass_dat->comdatum;
484
485 /* init permission_names */
486 if (common_dat &&
487 hashtab_map(common_dat->permissions.table,
488 dump_masked_av_helper, permission_names) < 0)
489 goto out;
490
491 if (hashtab_map(tclass_dat->permissions.table,
492 dump_masked_av_helper, permission_names) < 0)
493 goto out;
494
495 /* get scontext/tcontext in text form */
496 if (context_struct_to_string(scontext,
497 &scontext_name, &length) < 0)
498 goto out;
499
500 if (context_struct_to_string(tcontext,
501 &tcontext_name, &length) < 0)
502 goto out;
503
504 /* audit a message */
505 ab = audit_log_start(current->audit_context,
506 GFP_ATOMIC, AUDIT_SELINUX_ERR);
507 if (!ab)
508 goto out;
509
510 audit_log_format(ab, "op=security_compute_av reason=%s "
511 "scontext=%s tcontext=%s tclass=%s perms=",
512 reason, scontext_name, tcontext_name, tclass_name);
513
514 for (index = 0; index < 32; index++) {
515 u32 mask = (1 << index);
516
517 if ((mask & permissions) == 0)
518 continue;
519
520 audit_log_format(ab, "%s%s",
521 need_comma ? "," : "",
522 permission_names[index]
523 ? permission_names[index] : "????");
524 need_comma = true;
525 }
526 audit_log_end(ab);
527out:
528 /* release scontext/tcontext */
529 kfree(tcontext_name);
530 kfree(scontext_name);
531
532 return;
533}
534
535/*
536 * security_boundary_permission - drops violated permissions
537 * on boundary constraint.
538 */
539static void type_attribute_bounds_av(struct context *scontext,
540 struct context *tcontext,
541 u16 tclass,
542 struct av_decision *avd)
543{
544 struct context lo_scontext;
545 struct context lo_tcontext;
546 struct av_decision lo_avd;
547 struct type_datum *source;
548 struct type_datum *target;
549 u32 masked = 0;
550
551 source = flex_array_get_ptr(policydb.type_val_to_struct_array,
552 scontext->type - 1);
553 BUG_ON(!source);
554
555 target = flex_array_get_ptr(policydb.type_val_to_struct_array,
556 tcontext->type - 1);
557 BUG_ON(!target);
558
559 if (source->bounds) {
560 memset(&lo_avd, 0, sizeof(lo_avd));
561
562 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
563 lo_scontext.type = source->bounds;
564
565 context_struct_compute_av(&lo_scontext,
566 tcontext,
567 tclass,
568 &lo_avd);
569 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
570 return; /* no masked permission */
571 masked = ~lo_avd.allowed & avd->allowed;
572 }
573
574 if (target->bounds) {
575 memset(&lo_avd, 0, sizeof(lo_avd));
576
577 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
578 lo_tcontext.type = target->bounds;
579
580 context_struct_compute_av(scontext,
581 &lo_tcontext,
582 tclass,
583 &lo_avd);
584 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
585 return; /* no masked permission */
586 masked = ~lo_avd.allowed & avd->allowed;
587 }
588
589 if (source->bounds && target->bounds) {
590 memset(&lo_avd, 0, sizeof(lo_avd));
591 /*
592 * lo_scontext and lo_tcontext are already
593 * set up.
594 */
595
596 context_struct_compute_av(&lo_scontext,
597 &lo_tcontext,
598 tclass,
599 &lo_avd);
600 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
601 return; /* no masked permission */
602 masked = ~lo_avd.allowed & avd->allowed;
603 }
604
605 if (masked) {
606 /* mask violated permissions */
607 avd->allowed &= ~masked;
608
609 /* audit masked permissions */
610 security_dump_masked_av(scontext, tcontext,
611 tclass, masked, "bounds");
612 }
613}
614
615/*
616 * Compute access vectors based on a context structure pair for
617 * the permissions in a particular class.
618 */
619static void context_struct_compute_av(struct context *scontext,
620 struct context *tcontext,
621 u16 tclass,
622 struct av_decision *avd)
623{
624 struct constraint_node *constraint;
625 struct role_allow *ra;
626 struct avtab_key avkey;
627 struct avtab_node *node;
628 struct class_datum *tclass_datum;
629 struct ebitmap *sattr, *tattr;
630 struct ebitmap_node *snode, *tnode;
631 unsigned int i, j;
632
633 avd->allowed = 0;
634 avd->auditallow = 0;
635 avd->auditdeny = 0xffffffff;
636
637 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
638 if (printk_ratelimit())
639 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
640 return;
641 }
642
643 tclass_datum = policydb.class_val_to_struct[tclass - 1];
644
645 /*
646 * If a specific type enforcement rule was defined for
647 * this permission check, then use it.
648 */
649 avkey.target_class = tclass;
650 avkey.specified = AVTAB_AV;
651 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
652 BUG_ON(!sattr);
653 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
654 BUG_ON(!tattr);
655 ebitmap_for_each_positive_bit(sattr, snode, i) {
656 ebitmap_for_each_positive_bit(tattr, tnode, j) {
657 avkey.source_type = i + 1;
658 avkey.target_type = j + 1;
659 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
660 node;
661 node = avtab_search_node_next(node, avkey.specified)) {
662 if (node->key.specified == AVTAB_ALLOWED)
663 avd->allowed |= node->datum.data;
664 else if (node->key.specified == AVTAB_AUDITALLOW)
665 avd->auditallow |= node->datum.data;
666 else if (node->key.specified == AVTAB_AUDITDENY)
667 avd->auditdeny &= node->datum.data;
668 }
669
670 /* Check conditional av table for additional permissions */
671 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
672
673 }
674 }
675
676 /*
677 * Remove any permissions prohibited by a constraint (this includes
678 * the MLS policy).
679 */
680 constraint = tclass_datum->constraints;
681 while (constraint) {
682 if ((constraint->permissions & (avd->allowed)) &&
683 !constraint_expr_eval(scontext, tcontext, NULL,
684 constraint->expr)) {
685 avd->allowed &= ~(constraint->permissions);
686 }
687 constraint = constraint->next;
688 }
689
690 /*
691 * If checking process transition permission and the
692 * role is changing, then check the (current_role, new_role)
693 * pair.
694 */
695 if (tclass == policydb.process_class &&
696 (avd->allowed & policydb.process_trans_perms) &&
697 scontext->role != tcontext->role) {
698 for (ra = policydb.role_allow; ra; ra = ra->next) {
699 if (scontext->role == ra->role &&
700 tcontext->role == ra->new_role)
701 break;
702 }
703 if (!ra)
704 avd->allowed &= ~policydb.process_trans_perms;
705 }
706
707 /*
708 * If the given source and target types have boundary
709 * constraint, lazy checks have to mask any violated
710 * permission and notice it to userspace via audit.
711 */
712 type_attribute_bounds_av(scontext, tcontext,
713 tclass, avd);
714}
715
716static int security_validtrans_handle_fail(struct context *ocontext,
717 struct context *ncontext,
718 struct context *tcontext,
719 u16 tclass)
720{
721 char *o = NULL, *n = NULL, *t = NULL;
722 u32 olen, nlen, tlen;
723
724 if (context_struct_to_string(ocontext, &o, &olen))
725 goto out;
726 if (context_struct_to_string(ncontext, &n, &nlen))
727 goto out;
728 if (context_struct_to_string(tcontext, &t, &tlen))
729 goto out;
730 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
731 "security_validate_transition: denied for"
732 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
733 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
734out:
735 kfree(o);
736 kfree(n);
737 kfree(t);
738
739 if (!selinux_enforcing)
740 return 0;
741 return -EPERM;
742}
743
744int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
745 u16 orig_tclass)
746{
747 struct context *ocontext;
748 struct context *ncontext;
749 struct context *tcontext;
750 struct class_datum *tclass_datum;
751 struct constraint_node *constraint;
752 u16 tclass;
753 int rc = 0;
754
755 if (!ss_initialized)
756 return 0;
757
758 read_lock(&policy_rwlock);
759
760 tclass = unmap_class(orig_tclass);
761
762 if (!tclass || tclass > policydb.p_classes.nprim) {
763 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
764 __func__, tclass);
765 rc = -EINVAL;
766 goto out;
767 }
768 tclass_datum = policydb.class_val_to_struct[tclass - 1];
769
770 ocontext = sidtab_search(&sidtab, oldsid);
771 if (!ocontext) {
772 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
773 __func__, oldsid);
774 rc = -EINVAL;
775 goto out;
776 }
777
778 ncontext = sidtab_search(&sidtab, newsid);
779 if (!ncontext) {
780 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
781 __func__, newsid);
782 rc = -EINVAL;
783 goto out;
784 }
785
786 tcontext = sidtab_search(&sidtab, tasksid);
787 if (!tcontext) {
788 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
789 __func__, tasksid);
790 rc = -EINVAL;
791 goto out;
792 }
793
794 constraint = tclass_datum->validatetrans;
795 while (constraint) {
796 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
797 constraint->expr)) {
798 rc = security_validtrans_handle_fail(ocontext, ncontext,
799 tcontext, tclass);
800 goto out;
801 }
802 constraint = constraint->next;
803 }
804
805out:
806 read_unlock(&policy_rwlock);
807 return rc;
808}
809
810/*
811 * security_bounded_transition - check whether the given
812 * transition is directed to bounded, or not.
813 * It returns 0, if @newsid is bounded by @oldsid.
814 * Otherwise, it returns error code.
815 *
816 * @oldsid : current security identifier
817 * @newsid : destinated security identifier
818 */
819int security_bounded_transition(u32 old_sid, u32 new_sid)
820{
821 struct context *old_context, *new_context;
822 struct type_datum *type;
823 int index;
824 int rc;
825
826 read_lock(&policy_rwlock);
827
828 rc = -EINVAL;
829 old_context = sidtab_search(&sidtab, old_sid);
830 if (!old_context) {
831 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
832 __func__, old_sid);
833 goto out;
834 }
835
836 rc = -EINVAL;
837 new_context = sidtab_search(&sidtab, new_sid);
838 if (!new_context) {
839 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
840 __func__, new_sid);
841 goto out;
842 }
843
844 rc = 0;
845 /* type/domain unchanged */
846 if (old_context->type == new_context->type)
847 goto out;
848
849 index = new_context->type;
850 while (true) {
851 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
852 index - 1);
853 BUG_ON(!type);
854
855 /* not bounded anymore */
856 rc = -EPERM;
857 if (!type->bounds)
858 break;
859
860 /* @newsid is bounded by @oldsid */
861 rc = 0;
862 if (type->bounds == old_context->type)
863 break;
864
865 index = type->bounds;
866 }
867
868 if (rc) {
869 char *old_name = NULL;
870 char *new_name = NULL;
871 u32 length;
872
873 if (!context_struct_to_string(old_context,
874 &old_name, &length) &&
875 !context_struct_to_string(new_context,
876 &new_name, &length)) {
877 audit_log(current->audit_context,
878 GFP_ATOMIC, AUDIT_SELINUX_ERR,
879 "op=security_bounded_transition "
880 "result=denied "
881 "oldcontext=%s newcontext=%s",
882 old_name, new_name);
883 }
884 kfree(new_name);
885 kfree(old_name);
886 }
887out:
888 read_unlock(&policy_rwlock);
889
890 return rc;
891}
892
893static void avd_init(struct av_decision *avd)
894{
895 avd->allowed = 0;
896 avd->auditallow = 0;
897 avd->auditdeny = 0xffffffff;
898 avd->seqno = latest_granting;
899 avd->flags = 0;
900}
901
902
903/**
904 * security_compute_av - Compute access vector decisions.
905 * @ssid: source security identifier
906 * @tsid: target security identifier
907 * @tclass: target security class
908 * @avd: access vector decisions
909 *
910 * Compute a set of access vector decisions based on the
911 * SID pair (@ssid, @tsid) for the permissions in @tclass.
912 */
913void security_compute_av(u32 ssid,
914 u32 tsid,
915 u16 orig_tclass,
916 struct av_decision *avd)
917{
918 u16 tclass;
919 struct context *scontext = NULL, *tcontext = NULL;
920
921 read_lock(&policy_rwlock);
922 avd_init(avd);
923 if (!ss_initialized)
924 goto allow;
925
926 scontext = sidtab_search(&sidtab, ssid);
927 if (!scontext) {
928 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
929 __func__, ssid);
930 goto out;
931 }
932
933 /* permissive domain? */
934 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
935 avd->flags |= AVD_FLAGS_PERMISSIVE;
936
937 tcontext = sidtab_search(&sidtab, tsid);
938 if (!tcontext) {
939 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
940 __func__, tsid);
941 goto out;
942 }
943
944 tclass = unmap_class(orig_tclass);
945 if (unlikely(orig_tclass && !tclass)) {
946 if (policydb.allow_unknown)
947 goto allow;
948 goto out;
949 }
950 context_struct_compute_av(scontext, tcontext, tclass, avd);
951 map_decision(orig_tclass, avd, policydb.allow_unknown);
952out:
953 read_unlock(&policy_rwlock);
954 return;
955allow:
956 avd->allowed = 0xffffffff;
957 goto out;
958}
959
960void security_compute_av_user(u32 ssid,
961 u32 tsid,
962 u16 tclass,
963 struct av_decision *avd)
964{
965 struct context *scontext = NULL, *tcontext = NULL;
966
967 read_lock(&policy_rwlock);
968 avd_init(avd);
969 if (!ss_initialized)
970 goto allow;
971
972 scontext = sidtab_search(&sidtab, ssid);
973 if (!scontext) {
974 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
975 __func__, ssid);
976 goto out;
977 }
978
979 /* permissive domain? */
980 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
981 avd->flags |= AVD_FLAGS_PERMISSIVE;
982
983 tcontext = sidtab_search(&sidtab, tsid);
984 if (!tcontext) {
985 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
986 __func__, tsid);
987 goto out;
988 }
989
990 if (unlikely(!tclass)) {
991 if (policydb.allow_unknown)
992 goto allow;
993 goto out;
994 }
995
996 context_struct_compute_av(scontext, tcontext, tclass, avd);
997 out:
998 read_unlock(&policy_rwlock);
999 return;
1000allow:
1001 avd->allowed = 0xffffffff;
1002 goto out;
1003}
1004
1005/*
1006 * Write the security context string representation of
1007 * the context structure `context' into a dynamically
1008 * allocated string of the correct size. Set `*scontext'
1009 * to point to this string and set `*scontext_len' to
1010 * the length of the string.
1011 */
1012static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1013{
1014 char *scontextp;
1015
1016 if (scontext)
1017 *scontext = NULL;
1018 *scontext_len = 0;
1019
1020 if (context->len) {
1021 *scontext_len = context->len;
1022 if (scontext) {
1023 *scontext = kstrdup(context->str, GFP_ATOMIC);
1024 if (!(*scontext))
1025 return -ENOMEM;
1026 }
1027 return 0;
1028 }
1029
1030 /* Compute the size of the context. */
1031 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1032 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1033 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1034 *scontext_len += mls_compute_context_len(context);
1035
1036 if (!scontext)
1037 return 0;
1038
1039 /* Allocate space for the context; caller must free this space. */
1040 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1041 if (!scontextp)
1042 return -ENOMEM;
1043 *scontext = scontextp;
1044
1045 /*
1046 * Copy the user name, role name and type name into the context.
1047 */
1048 sprintf(scontextp, "%s:%s:%s",
1049 sym_name(&policydb, SYM_USERS, context->user - 1),
1050 sym_name(&policydb, SYM_ROLES, context->role - 1),
1051 sym_name(&policydb, SYM_TYPES, context->type - 1));
1052 scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1053 1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1054 1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1055
1056 mls_sid_to_context(context, &scontextp);
1057
1058 *scontextp = 0;
1059
1060 return 0;
1061}
1062
1063#include "initial_sid_to_string.h"
1064
1065const char *security_get_initial_sid_context(u32 sid)
1066{
1067 if (unlikely(sid > SECINITSID_NUM))
1068 return NULL;
1069 return initial_sid_to_string[sid];
1070}
1071
1072static int security_sid_to_context_core(u32 sid, char **scontext,
1073 u32 *scontext_len, int force)
1074{
1075 struct context *context;
1076 int rc = 0;
1077
1078 if (scontext)
1079 *scontext = NULL;
1080 *scontext_len = 0;
1081
1082 if (!ss_initialized) {
1083 if (sid <= SECINITSID_NUM) {
1084 char *scontextp;
1085
1086 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1087 if (!scontext)
1088 goto out;
1089 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1090 if (!scontextp) {
1091 rc = -ENOMEM;
1092 goto out;
1093 }
1094 strcpy(scontextp, initial_sid_to_string[sid]);
1095 *scontext = scontextp;
1096 goto out;
1097 }
1098 printk(KERN_ERR "SELinux: %s: called before initial "
1099 "load_policy on unknown SID %d\n", __func__, sid);
1100 rc = -EINVAL;
1101 goto out;
1102 }
1103 read_lock(&policy_rwlock);
1104 if (force)
1105 context = sidtab_search_force(&sidtab, sid);
1106 else
1107 context = sidtab_search(&sidtab, sid);
1108 if (!context) {
1109 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1110 __func__, sid);
1111 rc = -EINVAL;
1112 goto out_unlock;
1113 }
1114 rc = context_struct_to_string(context, scontext, scontext_len);
1115out_unlock:
1116 read_unlock(&policy_rwlock);
1117out:
1118 return rc;
1119
1120}
1121
1122/**
1123 * security_sid_to_context - Obtain a context for a given SID.
1124 * @sid: security identifier, SID
1125 * @scontext: security context
1126 * @scontext_len: length in bytes
1127 *
1128 * Write the string representation of the context associated with @sid
1129 * into a dynamically allocated string of the correct size. Set @scontext
1130 * to point to this string and set @scontext_len to the length of the string.
1131 */
1132int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1133{
1134 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1135}
1136
1137int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1138{
1139 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1140}
1141
1142/*
1143 * Caveat: Mutates scontext.
1144 */
1145static int string_to_context_struct(struct policydb *pol,
1146 struct sidtab *sidtabp,
1147 char *scontext,
1148 u32 scontext_len,
1149 struct context *ctx,
1150 u32 def_sid)
1151{
1152 struct role_datum *role;
1153 struct type_datum *typdatum;
1154 struct user_datum *usrdatum;
1155 char *scontextp, *p, oldc;
1156 int rc = 0;
1157
1158 context_init(ctx);
1159
1160 /* Parse the security context. */
1161
1162 rc = -EINVAL;
1163 scontextp = (char *) scontext;
1164
1165 /* Extract the user. */
1166 p = scontextp;
1167 while (*p && *p != ':')
1168 p++;
1169
1170 if (*p == 0)
1171 goto out;
1172
1173 *p++ = 0;
1174
1175 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1176 if (!usrdatum)
1177 goto out;
1178
1179 ctx->user = usrdatum->value;
1180
1181 /* Extract role. */
1182 scontextp = p;
1183 while (*p && *p != ':')
1184 p++;
1185
1186 if (*p == 0)
1187 goto out;
1188
1189 *p++ = 0;
1190
1191 role = hashtab_search(pol->p_roles.table, scontextp);
1192 if (!role)
1193 goto out;
1194 ctx->role = role->value;
1195
1196 /* Extract type. */
1197 scontextp = p;
1198 while (*p && *p != ':')
1199 p++;
1200 oldc = *p;
1201 *p++ = 0;
1202
1203 typdatum = hashtab_search(pol->p_types.table, scontextp);
1204 if (!typdatum || typdatum->attribute)
1205 goto out;
1206
1207 ctx->type = typdatum->value;
1208
1209 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1210 if (rc)
1211 goto out;
1212
1213 rc = -EINVAL;
1214 if ((p - scontext) < scontext_len)
1215 goto out;
1216
1217 /* Check the validity of the new context. */
1218 if (!policydb_context_isvalid(pol, ctx))
1219 goto out;
1220 rc = 0;
1221out:
1222 if (rc)
1223 context_destroy(ctx);
1224 return rc;
1225}
1226
1227static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1228 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1229 int force)
1230{
1231 char *scontext2, *str = NULL;
1232 struct context context;
1233 int rc = 0;
1234
1235 /* An empty security context is never valid. */
1236 if (!scontext_len)
1237 return -EINVAL;
1238
1239 if (!ss_initialized) {
1240 int i;
1241
1242 for (i = 1; i < SECINITSID_NUM; i++) {
1243 if (!strcmp(initial_sid_to_string[i], scontext)) {
1244 *sid = i;
1245 return 0;
1246 }
1247 }
1248 *sid = SECINITSID_KERNEL;
1249 return 0;
1250 }
1251 *sid = SECSID_NULL;
1252
1253 /* Copy the string so that we can modify the copy as we parse it. */
1254 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1255 if (!scontext2)
1256 return -ENOMEM;
1257 memcpy(scontext2, scontext, scontext_len);
1258 scontext2[scontext_len] = 0;
1259
1260 if (force) {
1261 /* Save another copy for storing in uninterpreted form */
1262 rc = -ENOMEM;
1263 str = kstrdup(scontext2, gfp_flags);
1264 if (!str)
1265 goto out;
1266 }
1267
1268 read_lock(&policy_rwlock);
1269 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1270 scontext_len, &context, def_sid);
1271 if (rc == -EINVAL && force) {
1272 context.str = str;
1273 context.len = scontext_len;
1274 str = NULL;
1275 } else if (rc)
1276 goto out_unlock;
1277 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1278 context_destroy(&context);
1279out_unlock:
1280 read_unlock(&policy_rwlock);
1281out:
1282 kfree(scontext2);
1283 kfree(str);
1284 return rc;
1285}
1286
1287/**
1288 * security_context_to_sid - Obtain a SID for a given security context.
1289 * @scontext: security context
1290 * @scontext_len: length in bytes
1291 * @sid: security identifier, SID
1292 * @gfp: context for the allocation
1293 *
1294 * Obtains a SID associated with the security context that
1295 * has the string representation specified by @scontext.
1296 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1297 * memory is available, or 0 on success.
1298 */
1299int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1300 gfp_t gfp)
1301{
1302 return security_context_to_sid_core(scontext, scontext_len,
1303 sid, SECSID_NULL, gfp, 0);
1304}
1305
1306/**
1307 * security_context_to_sid_default - Obtain a SID for a given security context,
1308 * falling back to specified default if needed.
1309 *
1310 * @scontext: security context
1311 * @scontext_len: length in bytes
1312 * @sid: security identifier, SID
1313 * @def_sid: default SID to assign on error
1314 *
1315 * Obtains a SID associated with the security context that
1316 * has the string representation specified by @scontext.
1317 * The default SID is passed to the MLS layer to be used to allow
1318 * kernel labeling of the MLS field if the MLS field is not present
1319 * (for upgrading to MLS without full relabel).
1320 * Implicitly forces adding of the context even if it cannot be mapped yet.
1321 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1322 * memory is available, or 0 on success.
1323 */
1324int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1325 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1326{
1327 return security_context_to_sid_core(scontext, scontext_len,
1328 sid, def_sid, gfp_flags, 1);
1329}
1330
1331int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1332 u32 *sid)
1333{
1334 return security_context_to_sid_core(scontext, scontext_len,
1335 sid, SECSID_NULL, GFP_KERNEL, 1);
1336}
1337
1338static int compute_sid_handle_invalid_context(
1339 struct context *scontext,
1340 struct context *tcontext,
1341 u16 tclass,
1342 struct context *newcontext)
1343{
1344 char *s = NULL, *t = NULL, *n = NULL;
1345 u32 slen, tlen, nlen;
1346
1347 if (context_struct_to_string(scontext, &s, &slen))
1348 goto out;
1349 if (context_struct_to_string(tcontext, &t, &tlen))
1350 goto out;
1351 if (context_struct_to_string(newcontext, &n, &nlen))
1352 goto out;
1353 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1354 "security_compute_sid: invalid context %s"
1355 " for scontext=%s"
1356 " tcontext=%s"
1357 " tclass=%s",
1358 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1359out:
1360 kfree(s);
1361 kfree(t);
1362 kfree(n);
1363 if (!selinux_enforcing)
1364 return 0;
1365 return -EACCES;
1366}
1367
1368static void filename_compute_type(struct policydb *p, struct context *newcontext,
1369 u32 stype, u32 ttype, u16 tclass,
1370 const char *objname)
1371{
1372 struct filename_trans ft;
1373 struct filename_trans_datum *otype;
1374
1375 /*
1376 * Most filename trans rules are going to live in specific directories
1377 * like /dev or /var/run. This bitmap will quickly skip rule searches
1378 * if the ttype does not contain any rules.
1379 */
1380 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1381 return;
1382
1383 ft.stype = stype;
1384 ft.ttype = ttype;
1385 ft.tclass = tclass;
1386 ft.name = objname;
1387
1388 otype = hashtab_search(p->filename_trans, &ft);
1389 if (otype)
1390 newcontext->type = otype->otype;
1391}
1392
1393static int security_compute_sid(u32 ssid,
1394 u32 tsid,
1395 u16 orig_tclass,
1396 u32 specified,
1397 const char *objname,
1398 u32 *out_sid,
1399 bool kern)
1400{
1401 struct class_datum *cladatum = NULL;
1402 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1403 struct role_trans *roletr = NULL;
1404 struct avtab_key avkey;
1405 struct avtab_datum *avdatum;
1406 struct avtab_node *node;
1407 u16 tclass;
1408 int rc = 0;
1409 bool sock;
1410
1411 if (!ss_initialized) {
1412 switch (orig_tclass) {
1413 case SECCLASS_PROCESS: /* kernel value */
1414 *out_sid = ssid;
1415 break;
1416 default:
1417 *out_sid = tsid;
1418 break;
1419 }
1420 goto out;
1421 }
1422
1423 context_init(&newcontext);
1424
1425 read_lock(&policy_rwlock);
1426
1427 if (kern) {
1428 tclass = unmap_class(orig_tclass);
1429 sock = security_is_socket_class(orig_tclass);
1430 } else {
1431 tclass = orig_tclass;
1432 sock = security_is_socket_class(map_class(tclass));
1433 }
1434
1435 scontext = sidtab_search(&sidtab, ssid);
1436 if (!scontext) {
1437 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1438 __func__, ssid);
1439 rc = -EINVAL;
1440 goto out_unlock;
1441 }
1442 tcontext = sidtab_search(&sidtab, tsid);
1443 if (!tcontext) {
1444 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1445 __func__, tsid);
1446 rc = -EINVAL;
1447 goto out_unlock;
1448 }
1449
1450 if (tclass && tclass <= policydb.p_classes.nprim)
1451 cladatum = policydb.class_val_to_struct[tclass - 1];
1452
1453 /* Set the user identity. */
1454 switch (specified) {
1455 case AVTAB_TRANSITION:
1456 case AVTAB_CHANGE:
1457 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1458 newcontext.user = tcontext->user;
1459 } else {
1460 /* notice this gets both DEFAULT_SOURCE and unset */
1461 /* Use the process user identity. */
1462 newcontext.user = scontext->user;
1463 }
1464 break;
1465 case AVTAB_MEMBER:
1466 /* Use the related object owner. */
1467 newcontext.user = tcontext->user;
1468 break;
1469 }
1470
1471 /* Set the role to default values. */
1472 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1473 newcontext.role = scontext->role;
1474 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1475 newcontext.role = tcontext->role;
1476 } else {
1477 if ((tclass == policydb.process_class) || (sock == true))
1478 newcontext.role = scontext->role;
1479 else
1480 newcontext.role = OBJECT_R_VAL;
1481 }
1482
1483 /* Set the type to default values. */
1484 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1485 newcontext.type = scontext->type;
1486 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1487 newcontext.type = tcontext->type;
1488 } else {
1489 if ((tclass == policydb.process_class) || (sock == true)) {
1490 /* Use the type of process. */
1491 newcontext.type = scontext->type;
1492 } else {
1493 /* Use the type of the related object. */
1494 newcontext.type = tcontext->type;
1495 }
1496 }
1497
1498 /* Look for a type transition/member/change rule. */
1499 avkey.source_type = scontext->type;
1500 avkey.target_type = tcontext->type;
1501 avkey.target_class = tclass;
1502 avkey.specified = specified;
1503 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1504
1505 /* If no permanent rule, also check for enabled conditional rules */
1506 if (!avdatum) {
1507 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1508 for (; node; node = avtab_search_node_next(node, specified)) {
1509 if (node->key.specified & AVTAB_ENABLED) {
1510 avdatum = &node->datum;
1511 break;
1512 }
1513 }
1514 }
1515
1516 if (avdatum) {
1517 /* Use the type from the type transition/member/change rule. */
1518 newcontext.type = avdatum->data;
1519 }
1520
1521 /* if we have a objname this is a file trans check so check those rules */
1522 if (objname)
1523 filename_compute_type(&policydb, &newcontext, scontext->type,
1524 tcontext->type, tclass, objname);
1525
1526 /* Check for class-specific changes. */
1527 if (specified & AVTAB_TRANSITION) {
1528 /* Look for a role transition rule. */
1529 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1530 if ((roletr->role == scontext->role) &&
1531 (roletr->type == tcontext->type) &&
1532 (roletr->tclass == tclass)) {
1533 /* Use the role transition rule. */
1534 newcontext.role = roletr->new_role;
1535 break;
1536 }
1537 }
1538 }
1539
1540 /* Set the MLS attributes.
1541 This is done last because it may allocate memory. */
1542 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1543 &newcontext, sock);
1544 if (rc)
1545 goto out_unlock;
1546
1547 /* Check the validity of the context. */
1548 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1549 rc = compute_sid_handle_invalid_context(scontext,
1550 tcontext,
1551 tclass,
1552 &newcontext);
1553 if (rc)
1554 goto out_unlock;
1555 }
1556 /* Obtain the sid for the context. */
1557 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1558out_unlock:
1559 read_unlock(&policy_rwlock);
1560 context_destroy(&newcontext);
1561out:
1562 return rc;
1563}
1564
1565/**
1566 * security_transition_sid - Compute the SID for a new subject/object.
1567 * @ssid: source security identifier
1568 * @tsid: target security identifier
1569 * @tclass: target security class
1570 * @out_sid: security identifier for new subject/object
1571 *
1572 * Compute a SID to use for labeling a new subject or object in the
1573 * class @tclass based on a SID pair (@ssid, @tsid).
1574 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1575 * if insufficient memory is available, or %0 if the new SID was
1576 * computed successfully.
1577 */
1578int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1579 const struct qstr *qstr, u32 *out_sid)
1580{
1581 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1582 qstr ? qstr->name : NULL, out_sid, true);
1583}
1584
1585int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1586 const char *objname, u32 *out_sid)
1587{
1588 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1589 objname, out_sid, false);
1590}
1591
1592/**
1593 * security_member_sid - Compute the SID for member selection.
1594 * @ssid: source security identifier
1595 * @tsid: target security identifier
1596 * @tclass: target security class
1597 * @out_sid: security identifier for selected member
1598 *
1599 * Compute a SID to use when selecting a member of a polyinstantiated
1600 * object of class @tclass based on a SID pair (@ssid, @tsid).
1601 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1602 * if insufficient memory is available, or %0 if the SID was
1603 * computed successfully.
1604 */
1605int security_member_sid(u32 ssid,
1606 u32 tsid,
1607 u16 tclass,
1608 u32 *out_sid)
1609{
1610 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1611 out_sid, false);
1612}
1613
1614/**
1615 * security_change_sid - Compute the SID for object relabeling.
1616 * @ssid: source security identifier
1617 * @tsid: target security identifier
1618 * @tclass: target security class
1619 * @out_sid: security identifier for selected member
1620 *
1621 * Compute a SID to use for relabeling an object of class @tclass
1622 * based on a SID pair (@ssid, @tsid).
1623 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1624 * if insufficient memory is available, or %0 if the SID was
1625 * computed successfully.
1626 */
1627int security_change_sid(u32 ssid,
1628 u32 tsid,
1629 u16 tclass,
1630 u32 *out_sid)
1631{
1632 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1633 out_sid, false);
1634}
1635
1636/* Clone the SID into the new SID table. */
1637static int clone_sid(u32 sid,
1638 struct context *context,
1639 void *arg)
1640{
1641 struct sidtab *s = arg;
1642
1643 if (sid > SECINITSID_NUM)
1644 return sidtab_insert(s, sid, context);
1645 else
1646 return 0;
1647}
1648
1649static inline int convert_context_handle_invalid_context(struct context *context)
1650{
1651 char *s;
1652 u32 len;
1653
1654 if (selinux_enforcing)
1655 return -EINVAL;
1656
1657 if (!context_struct_to_string(context, &s, &len)) {
1658 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1659 kfree(s);
1660 }
1661 return 0;
1662}
1663
1664struct convert_context_args {
1665 struct policydb *oldp;
1666 struct policydb *newp;
1667};
1668
1669/*
1670 * Convert the values in the security context
1671 * structure `c' from the values specified
1672 * in the policy `p->oldp' to the values specified
1673 * in the policy `p->newp'. Verify that the
1674 * context is valid under the new policy.
1675 */
1676static int convert_context(u32 key,
1677 struct context *c,
1678 void *p)
1679{
1680 struct convert_context_args *args;
1681 struct context oldc;
1682 struct ocontext *oc;
1683 struct mls_range *range;
1684 struct role_datum *role;
1685 struct type_datum *typdatum;
1686 struct user_datum *usrdatum;
1687 char *s;
1688 u32 len;
1689 int rc = 0;
1690
1691 if (key <= SECINITSID_NUM)
1692 goto out;
1693
1694 args = p;
1695
1696 if (c->str) {
1697 struct context ctx;
1698
1699 rc = -ENOMEM;
1700 s = kstrdup(c->str, GFP_KERNEL);
1701 if (!s)
1702 goto out;
1703
1704 rc = string_to_context_struct(args->newp, NULL, s,
1705 c->len, &ctx, SECSID_NULL);
1706 kfree(s);
1707 if (!rc) {
1708 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1709 c->str);
1710 /* Replace string with mapped representation. */
1711 kfree(c->str);
1712 memcpy(c, &ctx, sizeof(*c));
1713 goto out;
1714 } else if (rc == -EINVAL) {
1715 /* Retain string representation for later mapping. */
1716 rc = 0;
1717 goto out;
1718 } else {
1719 /* Other error condition, e.g. ENOMEM. */
1720 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1721 c->str, -rc);
1722 goto out;
1723 }
1724 }
1725
1726 rc = context_cpy(&oldc, c);
1727 if (rc)
1728 goto out;
1729
1730 /* Convert the user. */
1731 rc = -EINVAL;
1732 usrdatum = hashtab_search(args->newp->p_users.table,
1733 sym_name(args->oldp, SYM_USERS, c->user - 1));
1734 if (!usrdatum)
1735 goto bad;
1736 c->user = usrdatum->value;
1737
1738 /* Convert the role. */
1739 rc = -EINVAL;
1740 role = hashtab_search(args->newp->p_roles.table,
1741 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1742 if (!role)
1743 goto bad;
1744 c->role = role->value;
1745
1746 /* Convert the type. */
1747 rc = -EINVAL;
1748 typdatum = hashtab_search(args->newp->p_types.table,
1749 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1750 if (!typdatum)
1751 goto bad;
1752 c->type = typdatum->value;
1753
1754 /* Convert the MLS fields if dealing with MLS policies */
1755 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1756 rc = mls_convert_context(args->oldp, args->newp, c);
1757 if (rc)
1758 goto bad;
1759 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1760 /*
1761 * Switching between MLS and non-MLS policy:
1762 * free any storage used by the MLS fields in the
1763 * context for all existing entries in the sidtab.
1764 */
1765 mls_context_destroy(c);
1766 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1767 /*
1768 * Switching between non-MLS and MLS policy:
1769 * ensure that the MLS fields of the context for all
1770 * existing entries in the sidtab are filled in with a
1771 * suitable default value, likely taken from one of the
1772 * initial SIDs.
1773 */
1774 oc = args->newp->ocontexts[OCON_ISID];
1775 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1776 oc = oc->next;
1777 rc = -EINVAL;
1778 if (!oc) {
1779 printk(KERN_ERR "SELinux: unable to look up"
1780 " the initial SIDs list\n");
1781 goto bad;
1782 }
1783 range = &oc->context[0].range;
1784 rc = mls_range_set(c, range);
1785 if (rc)
1786 goto bad;
1787 }
1788
1789 /* Check the validity of the new context. */
1790 if (!policydb_context_isvalid(args->newp, c)) {
1791 rc = convert_context_handle_invalid_context(&oldc);
1792 if (rc)
1793 goto bad;
1794 }
1795
1796 context_destroy(&oldc);
1797
1798 rc = 0;
1799out:
1800 return rc;
1801bad:
1802 /* Map old representation to string and save it. */
1803 rc = context_struct_to_string(&oldc, &s, &len);
1804 if (rc)
1805 return rc;
1806 context_destroy(&oldc);
1807 context_destroy(c);
1808 c->str = s;
1809 c->len = len;
1810 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1811 c->str);
1812 rc = 0;
1813 goto out;
1814}
1815
1816static void security_load_policycaps(void)
1817{
1818 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1819 POLICYDB_CAPABILITY_NETPEER);
1820 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1821 POLICYDB_CAPABILITY_OPENPERM);
1822 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1823 POLICYDB_CAPABILITY_ALWAYSNETWORK);
1824}
1825
1826static int security_preserve_bools(struct policydb *p);
1827
1828/**
1829 * security_load_policy - Load a security policy configuration.
1830 * @data: binary policy data
1831 * @len: length of data in bytes
1832 *
1833 * Load a new set of security policy configuration data,
1834 * validate it and convert the SID table as necessary.
1835 * This function will flush the access vector cache after
1836 * loading the new policy.
1837 */
1838int security_load_policy(void *data, size_t len)
1839{
1840 struct policydb *oldpolicydb, *newpolicydb;
1841 struct sidtab oldsidtab, newsidtab;
1842 struct selinux_mapping *oldmap, *map = NULL;
1843 struct convert_context_args args;
1844 u32 seqno;
1845 u16 map_size;
1846 int rc = 0;
1847 struct policy_file file = { data, len }, *fp = &file;
1848
1849 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
1850 if (!oldpolicydb) {
1851 rc = -ENOMEM;
1852 goto out;
1853 }
1854 newpolicydb = oldpolicydb + 1;
1855
1856 if (!ss_initialized) {
1857 avtab_cache_init();
1858 rc = policydb_read(&policydb, fp);
1859 if (rc) {
1860 avtab_cache_destroy();
1861 goto out;
1862 }
1863
1864 policydb.len = len;
1865 rc = selinux_set_mapping(&policydb, secclass_map,
1866 ¤t_mapping,
1867 ¤t_mapping_size);
1868 if (rc) {
1869 policydb_destroy(&policydb);
1870 avtab_cache_destroy();
1871 goto out;
1872 }
1873
1874 rc = policydb_load_isids(&policydb, &sidtab);
1875 if (rc) {
1876 policydb_destroy(&policydb);
1877 avtab_cache_destroy();
1878 goto out;
1879 }
1880
1881 security_load_policycaps();
1882 ss_initialized = 1;
1883 seqno = ++latest_granting;
1884 selinux_complete_init();
1885 avc_ss_reset(seqno);
1886 selnl_notify_policyload(seqno);
1887 selinux_status_update_policyload(seqno);
1888 selinux_netlbl_cache_invalidate();
1889 selinux_xfrm_notify_policyload();
1890 goto out;
1891 }
1892
1893#if 0
1894 sidtab_hash_eval(&sidtab, "sids");
1895#endif
1896
1897 rc = policydb_read(newpolicydb, fp);
1898 if (rc)
1899 goto out;
1900
1901 newpolicydb->len = len;
1902 /* If switching between different policy types, log MLS status */
1903 if (policydb.mls_enabled && !newpolicydb->mls_enabled)
1904 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1905 else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
1906 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1907
1908 rc = policydb_load_isids(newpolicydb, &newsidtab);
1909 if (rc) {
1910 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
1911 policydb_destroy(newpolicydb);
1912 goto out;
1913 }
1914
1915 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
1916 if (rc)
1917 goto err;
1918
1919 rc = security_preserve_bools(newpolicydb);
1920 if (rc) {
1921 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
1922 goto err;
1923 }
1924
1925 /* Clone the SID table. */
1926 sidtab_shutdown(&sidtab);
1927
1928 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1929 if (rc)
1930 goto err;
1931
1932 /*
1933 * Convert the internal representations of contexts
1934 * in the new SID table.
1935 */
1936 args.oldp = &policydb;
1937 args.newp = newpolicydb;
1938 rc = sidtab_map(&newsidtab, convert_context, &args);
1939 if (rc) {
1940 printk(KERN_ERR "SELinux: unable to convert the internal"
1941 " representation of contexts in the new SID"
1942 " table\n");
1943 goto err;
1944 }
1945
1946 /* Save the old policydb and SID table to free later. */
1947 memcpy(oldpolicydb, &policydb, sizeof(policydb));
1948 sidtab_set(&oldsidtab, &sidtab);
1949
1950 /* Install the new policydb and SID table. */
1951 write_lock_irq(&policy_rwlock);
1952 memcpy(&policydb, newpolicydb, sizeof(policydb));
1953 sidtab_set(&sidtab, &newsidtab);
1954 security_load_policycaps();
1955 oldmap = current_mapping;
1956 current_mapping = map;
1957 current_mapping_size = map_size;
1958 seqno = ++latest_granting;
1959 write_unlock_irq(&policy_rwlock);
1960
1961 /* Free the old policydb and SID table. */
1962 policydb_destroy(oldpolicydb);
1963 sidtab_destroy(&oldsidtab);
1964 kfree(oldmap);
1965
1966 avc_ss_reset(seqno);
1967 selnl_notify_policyload(seqno);
1968 selinux_status_update_policyload(seqno);
1969 selinux_netlbl_cache_invalidate();
1970 selinux_xfrm_notify_policyload();
1971
1972 rc = 0;
1973 goto out;
1974
1975err:
1976 kfree(map);
1977 sidtab_destroy(&newsidtab);
1978 policydb_destroy(newpolicydb);
1979
1980out:
1981 kfree(oldpolicydb);
1982 return rc;
1983}
1984
1985size_t security_policydb_len(void)
1986{
1987 size_t len;
1988
1989 read_lock(&policy_rwlock);
1990 len = policydb.len;
1991 read_unlock(&policy_rwlock);
1992
1993 return len;
1994}
1995
1996/**
1997 * security_port_sid - Obtain the SID for a port.
1998 * @protocol: protocol number
1999 * @port: port number
2000 * @out_sid: security identifier
2001 */
2002int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2003{
2004 struct ocontext *c;
2005 int rc = 0;
2006
2007 read_lock(&policy_rwlock);
2008
2009 c = policydb.ocontexts[OCON_PORT];
2010 while (c) {
2011 if (c->u.port.protocol == protocol &&
2012 c->u.port.low_port <= port &&
2013 c->u.port.high_port >= port)
2014 break;
2015 c = c->next;
2016 }
2017
2018 if (c) {
2019 if (!c->sid[0]) {
2020 rc = sidtab_context_to_sid(&sidtab,
2021 &c->context[0],
2022 &c->sid[0]);
2023 if (rc)
2024 goto out;
2025 }
2026 *out_sid = c->sid[0];
2027 } else {
2028 *out_sid = SECINITSID_PORT;
2029 }
2030
2031out:
2032 read_unlock(&policy_rwlock);
2033 return rc;
2034}
2035
2036/**
2037 * security_netif_sid - Obtain the SID for a network interface.
2038 * @name: interface name
2039 * @if_sid: interface SID
2040 */
2041int security_netif_sid(char *name, u32 *if_sid)
2042{
2043 int rc = 0;
2044 struct ocontext *c;
2045
2046 read_lock(&policy_rwlock);
2047
2048 c = policydb.ocontexts[OCON_NETIF];
2049 while (c) {
2050 if (strcmp(name, c->u.name) == 0)
2051 break;
2052 c = c->next;
2053 }
2054
2055 if (c) {
2056 if (!c->sid[0] || !c->sid[1]) {
2057 rc = sidtab_context_to_sid(&sidtab,
2058 &c->context[0],
2059 &c->sid[0]);
2060 if (rc)
2061 goto out;
2062 rc = sidtab_context_to_sid(&sidtab,
2063 &c->context[1],
2064 &c->sid[1]);
2065 if (rc)
2066 goto out;
2067 }
2068 *if_sid = c->sid[0];
2069 } else
2070 *if_sid = SECINITSID_NETIF;
2071
2072out:
2073 read_unlock(&policy_rwlock);
2074 return rc;
2075}
2076
2077static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2078{
2079 int i, fail = 0;
2080
2081 for (i = 0; i < 4; i++)
2082 if (addr[i] != (input[i] & mask[i])) {
2083 fail = 1;
2084 break;
2085 }
2086
2087 return !fail;
2088}
2089
2090/**
2091 * security_node_sid - Obtain the SID for a node (host).
2092 * @domain: communication domain aka address family
2093 * @addrp: address
2094 * @addrlen: address length in bytes
2095 * @out_sid: security identifier
2096 */
2097int security_node_sid(u16 domain,
2098 void *addrp,
2099 u32 addrlen,
2100 u32 *out_sid)
2101{
2102 int rc;
2103 struct ocontext *c;
2104
2105 read_lock(&policy_rwlock);
2106
2107 switch (domain) {
2108 case AF_INET: {
2109 u32 addr;
2110
2111 rc = -EINVAL;
2112 if (addrlen != sizeof(u32))
2113 goto out;
2114
2115 addr = *((u32 *)addrp);
2116
2117 c = policydb.ocontexts[OCON_NODE];
2118 while (c) {
2119 if (c->u.node.addr == (addr & c->u.node.mask))
2120 break;
2121 c = c->next;
2122 }
2123 break;
2124 }
2125
2126 case AF_INET6:
2127 rc = -EINVAL;
2128 if (addrlen != sizeof(u64) * 2)
2129 goto out;
2130 c = policydb.ocontexts[OCON_NODE6];
2131 while (c) {
2132 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2133 c->u.node6.mask))
2134 break;
2135 c = c->next;
2136 }
2137 break;
2138
2139 default:
2140 rc = 0;
2141 *out_sid = SECINITSID_NODE;
2142 goto out;
2143 }
2144
2145 if (c) {
2146 if (!c->sid[0]) {
2147 rc = sidtab_context_to_sid(&sidtab,
2148 &c->context[0],
2149 &c->sid[0]);
2150 if (rc)
2151 goto out;
2152 }
2153 *out_sid = c->sid[0];
2154 } else {
2155 *out_sid = SECINITSID_NODE;
2156 }
2157
2158 rc = 0;
2159out:
2160 read_unlock(&policy_rwlock);
2161 return rc;
2162}
2163
2164#define SIDS_NEL 25
2165
2166/**
2167 * security_get_user_sids - Obtain reachable SIDs for a user.
2168 * @fromsid: starting SID
2169 * @username: username
2170 * @sids: array of reachable SIDs for user
2171 * @nel: number of elements in @sids
2172 *
2173 * Generate the set of SIDs for legal security contexts
2174 * for a given user that can be reached by @fromsid.
2175 * Set *@sids to point to a dynamically allocated
2176 * array containing the set of SIDs. Set *@nel to the
2177 * number of elements in the array.
2178 */
2179
2180int security_get_user_sids(u32 fromsid,
2181 char *username,
2182 u32 **sids,
2183 u32 *nel)
2184{
2185 struct context *fromcon, usercon;
2186 u32 *mysids = NULL, *mysids2, sid;
2187 u32 mynel = 0, maxnel = SIDS_NEL;
2188 struct user_datum *user;
2189 struct role_datum *role;
2190 struct ebitmap_node *rnode, *tnode;
2191 int rc = 0, i, j;
2192
2193 *sids = NULL;
2194 *nel = 0;
2195
2196 if (!ss_initialized)
2197 goto out;
2198
2199 read_lock(&policy_rwlock);
2200
2201 context_init(&usercon);
2202
2203 rc = -EINVAL;
2204 fromcon = sidtab_search(&sidtab, fromsid);
2205 if (!fromcon)
2206 goto out_unlock;
2207
2208 rc = -EINVAL;
2209 user = hashtab_search(policydb.p_users.table, username);
2210 if (!user)
2211 goto out_unlock;
2212
2213 usercon.user = user->value;
2214
2215 rc = -ENOMEM;
2216 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2217 if (!mysids)
2218 goto out_unlock;
2219
2220 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2221 role = policydb.role_val_to_struct[i];
2222 usercon.role = i + 1;
2223 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2224 usercon.type = j + 1;
2225
2226 if (mls_setup_user_range(fromcon, user, &usercon))
2227 continue;
2228
2229 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2230 if (rc)
2231 goto out_unlock;
2232 if (mynel < maxnel) {
2233 mysids[mynel++] = sid;
2234 } else {
2235 rc = -ENOMEM;
2236 maxnel += SIDS_NEL;
2237 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2238 if (!mysids2)
2239 goto out_unlock;
2240 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2241 kfree(mysids);
2242 mysids = mysids2;
2243 mysids[mynel++] = sid;
2244 }
2245 }
2246 }
2247 rc = 0;
2248out_unlock:
2249 read_unlock(&policy_rwlock);
2250 if (rc || !mynel) {
2251 kfree(mysids);
2252 goto out;
2253 }
2254
2255 rc = -ENOMEM;
2256 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2257 if (!mysids2) {
2258 kfree(mysids);
2259 goto out;
2260 }
2261 for (i = 0, j = 0; i < mynel; i++) {
2262 struct av_decision dummy_avd;
2263 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2264 SECCLASS_PROCESS, /* kernel value */
2265 PROCESS__TRANSITION, AVC_STRICT,
2266 &dummy_avd);
2267 if (!rc)
2268 mysids2[j++] = mysids[i];
2269 cond_resched();
2270 }
2271 rc = 0;
2272 kfree(mysids);
2273 *sids = mysids2;
2274 *nel = j;
2275out:
2276 return rc;
2277}
2278
2279/**
2280 * security_genfs_sid - Obtain a SID for a file in a filesystem
2281 * @fstype: filesystem type
2282 * @path: path from root of mount
2283 * @sclass: file security class
2284 * @sid: SID for path
2285 *
2286 * Obtain a SID to use for a file in a filesystem that
2287 * cannot support xattr or use a fixed labeling behavior like
2288 * transition SIDs or task SIDs.
2289 */
2290int security_genfs_sid(const char *fstype,
2291 char *path,
2292 u16 orig_sclass,
2293 u32 *sid)
2294{
2295 int len;
2296 u16 sclass;
2297 struct genfs *genfs;
2298 struct ocontext *c;
2299 int rc, cmp = 0;
2300
2301 while (path[0] == '/' && path[1] == '/')
2302 path++;
2303
2304 read_lock(&policy_rwlock);
2305
2306 sclass = unmap_class(orig_sclass);
2307 *sid = SECINITSID_UNLABELED;
2308
2309 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2310 cmp = strcmp(fstype, genfs->fstype);
2311 if (cmp <= 0)
2312 break;
2313 }
2314
2315 rc = -ENOENT;
2316 if (!genfs || cmp)
2317 goto out;
2318
2319 for (c = genfs->head; c; c = c->next) {
2320 len = strlen(c->u.name);
2321 if ((!c->v.sclass || sclass == c->v.sclass) &&
2322 (strncmp(c->u.name, path, len) == 0))
2323 break;
2324 }
2325
2326 rc = -ENOENT;
2327 if (!c)
2328 goto out;
2329
2330 if (!c->sid[0]) {
2331 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2332 if (rc)
2333 goto out;
2334 }
2335
2336 *sid = c->sid[0];
2337 rc = 0;
2338out:
2339 read_unlock(&policy_rwlock);
2340 return rc;
2341}
2342
2343/**
2344 * security_fs_use - Determine how to handle labeling for a filesystem.
2345 * @sb: superblock in question
2346 */
2347int security_fs_use(struct super_block *sb)
2348{
2349 int rc = 0;
2350 struct ocontext *c;
2351 struct superblock_security_struct *sbsec = sb->s_security;
2352 const char *fstype = sb->s_type->name;
2353
2354 read_lock(&policy_rwlock);
2355
2356 c = policydb.ocontexts[OCON_FSUSE];
2357 while (c) {
2358 if (strcmp(fstype, c->u.name) == 0)
2359 break;
2360 c = c->next;
2361 }
2362
2363 if (c) {
2364 sbsec->behavior = c->v.behavior;
2365 if (!c->sid[0]) {
2366 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2367 &c->sid[0]);
2368 if (rc)
2369 goto out;
2370 }
2371 sbsec->sid = c->sid[0];
2372 } else {
2373 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, &sbsec->sid);
2374 if (rc) {
2375 sbsec->behavior = SECURITY_FS_USE_NONE;
2376 rc = 0;
2377 } else {
2378 sbsec->behavior = SECURITY_FS_USE_GENFS;
2379 }
2380 }
2381
2382out:
2383 read_unlock(&policy_rwlock);
2384 return rc;
2385}
2386
2387int security_get_bools(int *len, char ***names, int **values)
2388{
2389 int i, rc;
2390
2391 read_lock(&policy_rwlock);
2392 *names = NULL;
2393 *values = NULL;
2394
2395 rc = 0;
2396 *len = policydb.p_bools.nprim;
2397 if (!*len)
2398 goto out;
2399
2400 rc = -ENOMEM;
2401 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2402 if (!*names)
2403 goto err;
2404
2405 rc = -ENOMEM;
2406 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2407 if (!*values)
2408 goto err;
2409
2410 for (i = 0; i < *len; i++) {
2411 size_t name_len;
2412
2413 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2414 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2415
2416 rc = -ENOMEM;
2417 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2418 if (!(*names)[i])
2419 goto err;
2420
2421 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2422 (*names)[i][name_len - 1] = 0;
2423 }
2424 rc = 0;
2425out:
2426 read_unlock(&policy_rwlock);
2427 return rc;
2428err:
2429 if (*names) {
2430 for (i = 0; i < *len; i++)
2431 kfree((*names)[i]);
2432 }
2433 kfree(*values);
2434 goto out;
2435}
2436
2437
2438int security_set_bools(int len, int *values)
2439{
2440 int i, rc;
2441 int lenp, seqno = 0;
2442 struct cond_node *cur;
2443
2444 write_lock_irq(&policy_rwlock);
2445
2446 rc = -EFAULT;
2447 lenp = policydb.p_bools.nprim;
2448 if (len != lenp)
2449 goto out;
2450
2451 for (i = 0; i < len; i++) {
2452 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2453 audit_log(current->audit_context, GFP_ATOMIC,
2454 AUDIT_MAC_CONFIG_CHANGE,
2455 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2456 sym_name(&policydb, SYM_BOOLS, i),
2457 !!values[i],
2458 policydb.bool_val_to_struct[i]->state,
2459 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2460 audit_get_sessionid(current));
2461 }
2462 if (values[i])
2463 policydb.bool_val_to_struct[i]->state = 1;
2464 else
2465 policydb.bool_val_to_struct[i]->state = 0;
2466 }
2467
2468 for (cur = policydb.cond_list; cur; cur = cur->next) {
2469 rc = evaluate_cond_node(&policydb, cur);
2470 if (rc)
2471 goto out;
2472 }
2473
2474 seqno = ++latest_granting;
2475 rc = 0;
2476out:
2477 write_unlock_irq(&policy_rwlock);
2478 if (!rc) {
2479 avc_ss_reset(seqno);
2480 selnl_notify_policyload(seqno);
2481 selinux_status_update_policyload(seqno);
2482 selinux_xfrm_notify_policyload();
2483 }
2484 return rc;
2485}
2486
2487int security_get_bool_value(int bool)
2488{
2489 int rc;
2490 int len;
2491
2492 read_lock(&policy_rwlock);
2493
2494 rc = -EFAULT;
2495 len = policydb.p_bools.nprim;
2496 if (bool >= len)
2497 goto out;
2498
2499 rc = policydb.bool_val_to_struct[bool]->state;
2500out:
2501 read_unlock(&policy_rwlock);
2502 return rc;
2503}
2504
2505static int security_preserve_bools(struct policydb *p)
2506{
2507 int rc, nbools = 0, *bvalues = NULL, i;
2508 char **bnames = NULL;
2509 struct cond_bool_datum *booldatum;
2510 struct cond_node *cur;
2511
2512 rc = security_get_bools(&nbools, &bnames, &bvalues);
2513 if (rc)
2514 goto out;
2515 for (i = 0; i < nbools; i++) {
2516 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2517 if (booldatum)
2518 booldatum->state = bvalues[i];
2519 }
2520 for (cur = p->cond_list; cur; cur = cur->next) {
2521 rc = evaluate_cond_node(p, cur);
2522 if (rc)
2523 goto out;
2524 }
2525
2526out:
2527 if (bnames) {
2528 for (i = 0; i < nbools; i++)
2529 kfree(bnames[i]);
2530 }
2531 kfree(bnames);
2532 kfree(bvalues);
2533 return rc;
2534}
2535
2536/*
2537 * security_sid_mls_copy() - computes a new sid based on the given
2538 * sid and the mls portion of mls_sid.
2539 */
2540int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2541{
2542 struct context *context1;
2543 struct context *context2;
2544 struct context newcon;
2545 char *s;
2546 u32 len;
2547 int rc;
2548
2549 rc = 0;
2550 if (!ss_initialized || !policydb.mls_enabled) {
2551 *new_sid = sid;
2552 goto out;
2553 }
2554
2555 context_init(&newcon);
2556
2557 read_lock(&policy_rwlock);
2558
2559 rc = -EINVAL;
2560 context1 = sidtab_search(&sidtab, sid);
2561 if (!context1) {
2562 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2563 __func__, sid);
2564 goto out_unlock;
2565 }
2566
2567 rc = -EINVAL;
2568 context2 = sidtab_search(&sidtab, mls_sid);
2569 if (!context2) {
2570 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2571 __func__, mls_sid);
2572 goto out_unlock;
2573 }
2574
2575 newcon.user = context1->user;
2576 newcon.role = context1->role;
2577 newcon.type = context1->type;
2578 rc = mls_context_cpy(&newcon, context2);
2579 if (rc)
2580 goto out_unlock;
2581
2582 /* Check the validity of the new context. */
2583 if (!policydb_context_isvalid(&policydb, &newcon)) {
2584 rc = convert_context_handle_invalid_context(&newcon);
2585 if (rc) {
2586 if (!context_struct_to_string(&newcon, &s, &len)) {
2587 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2588 "security_sid_mls_copy: invalid context %s", s);
2589 kfree(s);
2590 }
2591 goto out_unlock;
2592 }
2593 }
2594
2595 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2596out_unlock:
2597 read_unlock(&policy_rwlock);
2598 context_destroy(&newcon);
2599out:
2600 return rc;
2601}
2602
2603/**
2604 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2605 * @nlbl_sid: NetLabel SID
2606 * @nlbl_type: NetLabel labeling protocol type
2607 * @xfrm_sid: XFRM SID
2608 *
2609 * Description:
2610 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2611 * resolved into a single SID it is returned via @peer_sid and the function
2612 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2613 * returns a negative value. A table summarizing the behavior is below:
2614 *
2615 * | function return | @sid
2616 * ------------------------------+-----------------+-----------------
2617 * no peer labels | 0 | SECSID_NULL
2618 * single peer label | 0 | <peer_label>
2619 * multiple, consistent labels | 0 | <peer_label>
2620 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2621 *
2622 */
2623int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2624 u32 xfrm_sid,
2625 u32 *peer_sid)
2626{
2627 int rc;
2628 struct context *nlbl_ctx;
2629 struct context *xfrm_ctx;
2630
2631 *peer_sid = SECSID_NULL;
2632
2633 /* handle the common (which also happens to be the set of easy) cases
2634 * right away, these two if statements catch everything involving a
2635 * single or absent peer SID/label */
2636 if (xfrm_sid == SECSID_NULL) {
2637 *peer_sid = nlbl_sid;
2638 return 0;
2639 }
2640 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2641 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2642 * is present */
2643 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2644 *peer_sid = xfrm_sid;
2645 return 0;
2646 }
2647
2648 /* we don't need to check ss_initialized here since the only way both
2649 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2650 * security server was initialized and ss_initialized was true */
2651 if (!policydb.mls_enabled)
2652 return 0;
2653
2654 read_lock(&policy_rwlock);
2655
2656 rc = -EINVAL;
2657 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2658 if (!nlbl_ctx) {
2659 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2660 __func__, nlbl_sid);
2661 goto out;
2662 }
2663 rc = -EINVAL;
2664 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2665 if (!xfrm_ctx) {
2666 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2667 __func__, xfrm_sid);
2668 goto out;
2669 }
2670 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2671 if (rc)
2672 goto out;
2673
2674 /* at present NetLabel SIDs/labels really only carry MLS
2675 * information so if the MLS portion of the NetLabel SID
2676 * matches the MLS portion of the labeled XFRM SID/label
2677 * then pass along the XFRM SID as it is the most
2678 * expressive */
2679 *peer_sid = xfrm_sid;
2680out:
2681 read_unlock(&policy_rwlock);
2682 return rc;
2683}
2684
2685static int get_classes_callback(void *k, void *d, void *args)
2686{
2687 struct class_datum *datum = d;
2688 char *name = k, **classes = args;
2689 int value = datum->value - 1;
2690
2691 classes[value] = kstrdup(name, GFP_ATOMIC);
2692 if (!classes[value])
2693 return -ENOMEM;
2694
2695 return 0;
2696}
2697
2698int security_get_classes(char ***classes, int *nclasses)
2699{
2700 int rc;
2701
2702 read_lock(&policy_rwlock);
2703
2704 rc = -ENOMEM;
2705 *nclasses = policydb.p_classes.nprim;
2706 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2707 if (!*classes)
2708 goto out;
2709
2710 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2711 *classes);
2712 if (rc) {
2713 int i;
2714 for (i = 0; i < *nclasses; i++)
2715 kfree((*classes)[i]);
2716 kfree(*classes);
2717 }
2718
2719out:
2720 read_unlock(&policy_rwlock);
2721 return rc;
2722}
2723
2724static int get_permissions_callback(void *k, void *d, void *args)
2725{
2726 struct perm_datum *datum = d;
2727 char *name = k, **perms = args;
2728 int value = datum->value - 1;
2729
2730 perms[value] = kstrdup(name, GFP_ATOMIC);
2731 if (!perms[value])
2732 return -ENOMEM;
2733
2734 return 0;
2735}
2736
2737int security_get_permissions(char *class, char ***perms, int *nperms)
2738{
2739 int rc, i;
2740 struct class_datum *match;
2741
2742 read_lock(&policy_rwlock);
2743
2744 rc = -EINVAL;
2745 match = hashtab_search(policydb.p_classes.table, class);
2746 if (!match) {
2747 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2748 __func__, class);
2749 goto out;
2750 }
2751
2752 rc = -ENOMEM;
2753 *nperms = match->permissions.nprim;
2754 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2755 if (!*perms)
2756 goto out;
2757
2758 if (match->comdatum) {
2759 rc = hashtab_map(match->comdatum->permissions.table,
2760 get_permissions_callback, *perms);
2761 if (rc)
2762 goto err;
2763 }
2764
2765 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2766 *perms);
2767 if (rc)
2768 goto err;
2769
2770out:
2771 read_unlock(&policy_rwlock);
2772 return rc;
2773
2774err:
2775 read_unlock(&policy_rwlock);
2776 for (i = 0; i < *nperms; i++)
2777 kfree((*perms)[i]);
2778 kfree(*perms);
2779 return rc;
2780}
2781
2782int security_get_reject_unknown(void)
2783{
2784 return policydb.reject_unknown;
2785}
2786
2787int security_get_allow_unknown(void)
2788{
2789 return policydb.allow_unknown;
2790}
2791
2792/**
2793 * security_policycap_supported - Check for a specific policy capability
2794 * @req_cap: capability
2795 *
2796 * Description:
2797 * This function queries the currently loaded policy to see if it supports the
2798 * capability specified by @req_cap. Returns true (1) if the capability is
2799 * supported, false (0) if it isn't supported.
2800 *
2801 */
2802int security_policycap_supported(unsigned int req_cap)
2803{
2804 int rc;
2805
2806 read_lock(&policy_rwlock);
2807 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2808 read_unlock(&policy_rwlock);
2809
2810 return rc;
2811}
2812
2813struct selinux_audit_rule {
2814 u32 au_seqno;
2815 struct context au_ctxt;
2816};
2817
2818void selinux_audit_rule_free(void *vrule)
2819{
2820 struct selinux_audit_rule *rule = vrule;
2821
2822 if (rule) {
2823 context_destroy(&rule->au_ctxt);
2824 kfree(rule);
2825 }
2826}
2827
2828int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2829{
2830 struct selinux_audit_rule *tmprule;
2831 struct role_datum *roledatum;
2832 struct type_datum *typedatum;
2833 struct user_datum *userdatum;
2834 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2835 int rc = 0;
2836
2837 *rule = NULL;
2838
2839 if (!ss_initialized)
2840 return -EOPNOTSUPP;
2841
2842 switch (field) {
2843 case AUDIT_SUBJ_USER:
2844 case AUDIT_SUBJ_ROLE:
2845 case AUDIT_SUBJ_TYPE:
2846 case AUDIT_OBJ_USER:
2847 case AUDIT_OBJ_ROLE:
2848 case AUDIT_OBJ_TYPE:
2849 /* only 'equals' and 'not equals' fit user, role, and type */
2850 if (op != Audit_equal && op != Audit_not_equal)
2851 return -EINVAL;
2852 break;
2853 case AUDIT_SUBJ_SEN:
2854 case AUDIT_SUBJ_CLR:
2855 case AUDIT_OBJ_LEV_LOW:
2856 case AUDIT_OBJ_LEV_HIGH:
2857 /* we do not allow a range, indicated by the presence of '-' */
2858 if (strchr(rulestr, '-'))
2859 return -EINVAL;
2860 break;
2861 default:
2862 /* only the above fields are valid */
2863 return -EINVAL;
2864 }
2865
2866 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2867 if (!tmprule)
2868 return -ENOMEM;
2869
2870 context_init(&tmprule->au_ctxt);
2871
2872 read_lock(&policy_rwlock);
2873
2874 tmprule->au_seqno = latest_granting;
2875
2876 switch (field) {
2877 case AUDIT_SUBJ_USER:
2878 case AUDIT_OBJ_USER:
2879 rc = -EINVAL;
2880 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2881 if (!userdatum)
2882 goto out;
2883 tmprule->au_ctxt.user = userdatum->value;
2884 break;
2885 case AUDIT_SUBJ_ROLE:
2886 case AUDIT_OBJ_ROLE:
2887 rc = -EINVAL;
2888 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2889 if (!roledatum)
2890 goto out;
2891 tmprule->au_ctxt.role = roledatum->value;
2892 break;
2893 case AUDIT_SUBJ_TYPE:
2894 case AUDIT_OBJ_TYPE:
2895 rc = -EINVAL;
2896 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2897 if (!typedatum)
2898 goto out;
2899 tmprule->au_ctxt.type = typedatum->value;
2900 break;
2901 case AUDIT_SUBJ_SEN:
2902 case AUDIT_SUBJ_CLR:
2903 case AUDIT_OBJ_LEV_LOW:
2904 case AUDIT_OBJ_LEV_HIGH:
2905 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2906 if (rc)
2907 goto out;
2908 break;
2909 }
2910 rc = 0;
2911out:
2912 read_unlock(&policy_rwlock);
2913
2914 if (rc) {
2915 selinux_audit_rule_free(tmprule);
2916 tmprule = NULL;
2917 }
2918
2919 *rule = tmprule;
2920
2921 return rc;
2922}
2923
2924/* Check to see if the rule contains any selinux fields */
2925int selinux_audit_rule_known(struct audit_krule *rule)
2926{
2927 int i;
2928
2929 for (i = 0; i < rule->field_count; i++) {
2930 struct audit_field *f = &rule->fields[i];
2931 switch (f->type) {
2932 case AUDIT_SUBJ_USER:
2933 case AUDIT_SUBJ_ROLE:
2934 case AUDIT_SUBJ_TYPE:
2935 case AUDIT_SUBJ_SEN:
2936 case AUDIT_SUBJ_CLR:
2937 case AUDIT_OBJ_USER:
2938 case AUDIT_OBJ_ROLE:
2939 case AUDIT_OBJ_TYPE:
2940 case AUDIT_OBJ_LEV_LOW:
2941 case AUDIT_OBJ_LEV_HIGH:
2942 return 1;
2943 }
2944 }
2945
2946 return 0;
2947}
2948
2949int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2950 struct audit_context *actx)
2951{
2952 struct context *ctxt;
2953 struct mls_level *level;
2954 struct selinux_audit_rule *rule = vrule;
2955 int match = 0;
2956
2957 if (unlikely(!rule)) {
2958 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
2959 return -ENOENT;
2960 }
2961
2962 read_lock(&policy_rwlock);
2963
2964 if (rule->au_seqno < latest_granting) {
2965 match = -ESTALE;
2966 goto out;
2967 }
2968
2969 ctxt = sidtab_search(&sidtab, sid);
2970 if (unlikely(!ctxt)) {
2971 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
2972 sid);
2973 match = -ENOENT;
2974 goto out;
2975 }
2976
2977 /* a field/op pair that is not caught here will simply fall through
2978 without a match */
2979 switch (field) {
2980 case AUDIT_SUBJ_USER:
2981 case AUDIT_OBJ_USER:
2982 switch (op) {
2983 case Audit_equal:
2984 match = (ctxt->user == rule->au_ctxt.user);
2985 break;
2986 case Audit_not_equal:
2987 match = (ctxt->user != rule->au_ctxt.user);
2988 break;
2989 }
2990 break;
2991 case AUDIT_SUBJ_ROLE:
2992 case AUDIT_OBJ_ROLE:
2993 switch (op) {
2994 case Audit_equal:
2995 match = (ctxt->role == rule->au_ctxt.role);
2996 break;
2997 case Audit_not_equal:
2998 match = (ctxt->role != rule->au_ctxt.role);
2999 break;
3000 }
3001 break;
3002 case AUDIT_SUBJ_TYPE:
3003 case AUDIT_OBJ_TYPE:
3004 switch (op) {
3005 case Audit_equal:
3006 match = (ctxt->type == rule->au_ctxt.type);
3007 break;
3008 case Audit_not_equal:
3009 match = (ctxt->type != rule->au_ctxt.type);
3010 break;
3011 }
3012 break;
3013 case AUDIT_SUBJ_SEN:
3014 case AUDIT_SUBJ_CLR:
3015 case AUDIT_OBJ_LEV_LOW:
3016 case AUDIT_OBJ_LEV_HIGH:
3017 level = ((field == AUDIT_SUBJ_SEN ||
3018 field == AUDIT_OBJ_LEV_LOW) ?
3019 &ctxt->range.level[0] : &ctxt->range.level[1]);
3020 switch (op) {
3021 case Audit_equal:
3022 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3023 level);
3024 break;
3025 case Audit_not_equal:
3026 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3027 level);
3028 break;
3029 case Audit_lt:
3030 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3031 level) &&
3032 !mls_level_eq(&rule->au_ctxt.range.level[0],
3033 level));
3034 break;
3035 case Audit_le:
3036 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3037 level);
3038 break;
3039 case Audit_gt:
3040 match = (mls_level_dom(level,
3041 &rule->au_ctxt.range.level[0]) &&
3042 !mls_level_eq(level,
3043 &rule->au_ctxt.range.level[0]));
3044 break;
3045 case Audit_ge:
3046 match = mls_level_dom(level,
3047 &rule->au_ctxt.range.level[0]);
3048 break;
3049 }
3050 }
3051
3052out:
3053 read_unlock(&policy_rwlock);
3054 return match;
3055}
3056
3057static int (*aurule_callback)(void) = audit_update_lsm_rules;
3058
3059static int aurule_avc_callback(u32 event)
3060{
3061 int err = 0;
3062
3063 if (event == AVC_CALLBACK_RESET && aurule_callback)
3064 err = aurule_callback();
3065 return err;
3066}
3067
3068static int __init aurule_init(void)
3069{
3070 int err;
3071
3072 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3073 if (err)
3074 panic("avc_add_callback() failed, error %d\n", err);
3075
3076 return err;
3077}
3078__initcall(aurule_init);
3079
3080#ifdef CONFIG_NETLABEL
3081/**
3082 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3083 * @secattr: the NetLabel packet security attributes
3084 * @sid: the SELinux SID
3085 *
3086 * Description:
3087 * Attempt to cache the context in @ctx, which was derived from the packet in
3088 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3089 * already been initialized.
3090 *
3091 */
3092static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3093 u32 sid)
3094{
3095 u32 *sid_cache;
3096
3097 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3098 if (sid_cache == NULL)
3099 return;
3100 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3101 if (secattr->cache == NULL) {
3102 kfree(sid_cache);
3103 return;
3104 }
3105
3106 *sid_cache = sid;
3107 secattr->cache->free = kfree;
3108 secattr->cache->data = sid_cache;
3109 secattr->flags |= NETLBL_SECATTR_CACHE;
3110}
3111
3112/**
3113 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3114 * @secattr: the NetLabel packet security attributes
3115 * @sid: the SELinux SID
3116 *
3117 * Description:
3118 * Convert the given NetLabel security attributes in @secattr into a
3119 * SELinux SID. If the @secattr field does not contain a full SELinux
3120 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3121 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3122 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3123 * conversion for future lookups. Returns zero on success, negative values on
3124 * failure.
3125 *
3126 */
3127int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3128 u32 *sid)
3129{
3130 int rc;
3131 struct context *ctx;
3132 struct context ctx_new;
3133
3134 if (!ss_initialized) {
3135 *sid = SECSID_NULL;
3136 return 0;
3137 }
3138
3139 read_lock(&policy_rwlock);
3140
3141 if (secattr->flags & NETLBL_SECATTR_CACHE)
3142 *sid = *(u32 *)secattr->cache->data;
3143 else if (secattr->flags & NETLBL_SECATTR_SECID)
3144 *sid = secattr->attr.secid;
3145 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3146 rc = -EIDRM;
3147 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3148 if (ctx == NULL)
3149 goto out;
3150
3151 context_init(&ctx_new);
3152 ctx_new.user = ctx->user;
3153 ctx_new.role = ctx->role;
3154 ctx_new.type = ctx->type;
3155 mls_import_netlbl_lvl(&ctx_new, secattr);
3156 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3157 rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3158 secattr->attr.mls.cat);
3159 if (rc)
3160 goto out;
3161 memcpy(&ctx_new.range.level[1].cat,
3162 &ctx_new.range.level[0].cat,
3163 sizeof(ctx_new.range.level[0].cat));
3164 }
3165 rc = -EIDRM;
3166 if (!mls_context_isvalid(&policydb, &ctx_new))
3167 goto out_free;
3168
3169 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3170 if (rc)
3171 goto out_free;
3172
3173 security_netlbl_cache_add(secattr, *sid);
3174
3175 ebitmap_destroy(&ctx_new.range.level[0].cat);
3176 } else
3177 *sid = SECSID_NULL;
3178
3179 read_unlock(&policy_rwlock);
3180 return 0;
3181out_free:
3182 ebitmap_destroy(&ctx_new.range.level[0].cat);
3183out:
3184 read_unlock(&policy_rwlock);
3185 return rc;
3186}
3187
3188/**
3189 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3190 * @sid: the SELinux SID
3191 * @secattr: the NetLabel packet security attributes
3192 *
3193 * Description:
3194 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3195 * Returns zero on success, negative values on failure.
3196 *
3197 */
3198int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3199{
3200 int rc;
3201 struct context *ctx;
3202
3203 if (!ss_initialized)
3204 return 0;
3205
3206 read_lock(&policy_rwlock);
3207
3208 rc = -ENOENT;
3209 ctx = sidtab_search(&sidtab, sid);
3210 if (ctx == NULL)
3211 goto out;
3212
3213 rc = -ENOMEM;
3214 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3215 GFP_ATOMIC);
3216 if (secattr->domain == NULL)
3217 goto out;
3218
3219 secattr->attr.secid = sid;
3220 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3221 mls_export_netlbl_lvl(ctx, secattr);
3222 rc = mls_export_netlbl_cat(ctx, secattr);
3223out:
3224 read_unlock(&policy_rwlock);
3225 return rc;
3226}
3227#endif /* CONFIG_NETLABEL */
3228
3229/**
3230 * security_read_policy - read the policy.
3231 * @data: binary policy data
3232 * @len: length of data in bytes
3233 *
3234 */
3235int security_read_policy(void **data, size_t *len)
3236{
3237 int rc;
3238 struct policy_file fp;
3239
3240 if (!ss_initialized)
3241 return -EINVAL;
3242
3243 *len = security_policydb_len();
3244
3245 *data = vmalloc_user(*len);
3246 if (!*data)
3247 return -ENOMEM;
3248
3249 fp.data = *data;
3250 fp.len = *len;
3251
3252 read_lock(&policy_rwlock);
3253 rc = policydb_write(&policydb, &fp);
3254 read_unlock(&policy_rwlock);
3255
3256 if (rc)
3257 return rc;
3258
3259 *len = (unsigned long)fp.data - (unsigned long)*data;
3260 return 0;
3261
3262}