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