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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/vmalloc.h>
50#include <linux/lsm_hooks.h>
51#include <net/netlabel.h>
52
53#include "flask.h"
54#include "avc.h"
55#include "avc_ss.h"
56#include "security.h"
57#include "context.h"
58#include "policydb.h"
59#include "sidtab.h"
60#include "services.h"
61#include "conditional.h"
62#include "mls.h"
63#include "objsec.h"
64#include "netlabel.h"
65#include "xfrm.h"
66#include "ebitmap.h"
67#include "audit.h"
68#include "policycap_names.h"
69#include "ima.h"
70
71struct selinux_policy_convert_data {
72 struct convert_context_args args;
73 struct sidtab_convert_params sidtab_params;
74};
75
76/* Forward declaration. */
77static int context_struct_to_string(struct policydb *policydb,
78 struct context *context,
79 char **scontext,
80 u32 *scontext_len);
81
82static int sidtab_entry_to_string(struct policydb *policydb,
83 struct sidtab *sidtab,
84 struct sidtab_entry *entry,
85 char **scontext,
86 u32 *scontext_len);
87
88static void context_struct_compute_av(struct policydb *policydb,
89 struct context *scontext,
90 struct context *tcontext,
91 u16 tclass,
92 struct av_decision *avd,
93 struct extended_perms *xperms);
94
95static int selinux_set_mapping(struct policydb *pol,
96 const struct security_class_mapping *map,
97 struct selinux_map *out_map)
98{
99 u16 i, j;
100 unsigned k;
101 bool print_unknown_handle = false;
102
103 /* Find number of classes in the input mapping */
104 if (!map)
105 return -EINVAL;
106 i = 0;
107 while (map[i].name)
108 i++;
109
110 /* Allocate space for the class records, plus one for class zero */
111 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
112 if (!out_map->mapping)
113 return -ENOMEM;
114
115 /* Store the raw class and permission values */
116 j = 0;
117 while (map[j].name) {
118 const struct security_class_mapping *p_in = map + (j++);
119 struct selinux_mapping *p_out = out_map->mapping + j;
120
121 /* An empty class string skips ahead */
122 if (!strcmp(p_in->name, "")) {
123 p_out->num_perms = 0;
124 continue;
125 }
126
127 p_out->value = string_to_security_class(pol, p_in->name);
128 if (!p_out->value) {
129 pr_info("SELinux: Class %s not defined in policy.\n",
130 p_in->name);
131 if (pol->reject_unknown)
132 goto err;
133 p_out->num_perms = 0;
134 print_unknown_handle = true;
135 continue;
136 }
137
138 k = 0;
139 while (p_in->perms[k]) {
140 /* An empty permission string skips ahead */
141 if (!*p_in->perms[k]) {
142 k++;
143 continue;
144 }
145 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
146 p_in->perms[k]);
147 if (!p_out->perms[k]) {
148 pr_info("SELinux: Permission %s in class %s not defined in policy.\n",
149 p_in->perms[k], p_in->name);
150 if (pol->reject_unknown)
151 goto err;
152 print_unknown_handle = true;
153 }
154
155 k++;
156 }
157 p_out->num_perms = k;
158 }
159
160 if (print_unknown_handle)
161 pr_info("SELinux: the above unknown classes and permissions will be %s\n",
162 pol->allow_unknown ? "allowed" : "denied");
163
164 out_map->size = i;
165 return 0;
166err:
167 kfree(out_map->mapping);
168 out_map->mapping = NULL;
169 return -EINVAL;
170}
171
172/*
173 * Get real, policy values from mapped values
174 */
175
176static u16 unmap_class(struct selinux_map *map, u16 tclass)
177{
178 if (tclass < map->size)
179 return map->mapping[tclass].value;
180
181 return tclass;
182}
183
184/*
185 * Get kernel value for class from its policy value
186 */
187static u16 map_class(struct selinux_map *map, u16 pol_value)
188{
189 u16 i;
190
191 for (i = 1; i < map->size; i++) {
192 if (map->mapping[i].value == pol_value)
193 return i;
194 }
195
196 return SECCLASS_NULL;
197}
198
199static void map_decision(struct selinux_map *map,
200 u16 tclass, struct av_decision *avd,
201 int allow_unknown)
202{
203 if (tclass < map->size) {
204 struct selinux_mapping *mapping = &map->mapping[tclass];
205 unsigned int i, n = mapping->num_perms;
206 u32 result;
207
208 for (i = 0, result = 0; i < n; i++) {
209 if (avd->allowed & mapping->perms[i])
210 result |= 1<<i;
211 if (allow_unknown && !mapping->perms[i])
212 result |= 1<<i;
213 }
214 avd->allowed = result;
215
216 for (i = 0, result = 0; i < n; i++)
217 if (avd->auditallow & mapping->perms[i])
218 result |= 1<<i;
219 avd->auditallow = result;
220
221 for (i = 0, result = 0; i < n; i++) {
222 if (avd->auditdeny & mapping->perms[i])
223 result |= 1<<i;
224 if (!allow_unknown && !mapping->perms[i])
225 result |= 1<<i;
226 }
227 /*
228 * In case the kernel has a bug and requests a permission
229 * between num_perms and the maximum permission number, we
230 * should audit that denial
231 */
232 for (; i < (sizeof(u32)*8); i++)
233 result |= 1<<i;
234 avd->auditdeny = result;
235 }
236}
237
238int security_mls_enabled(struct selinux_state *state)
239{
240 int mls_enabled;
241 struct selinux_policy *policy;
242
243 if (!selinux_initialized(state))
244 return 0;
245
246 rcu_read_lock();
247 policy = rcu_dereference(state->policy);
248 mls_enabled = policy->policydb.mls_enabled;
249 rcu_read_unlock();
250 return mls_enabled;
251}
252
253/*
254 * Return the boolean value of a constraint expression
255 * when it is applied to the specified source and target
256 * security contexts.
257 *
258 * xcontext is a special beast... It is used by the validatetrans rules
259 * only. For these rules, scontext is the context before the transition,
260 * tcontext is the context after the transition, and xcontext is the context
261 * of the process performing the transition. All other callers of
262 * constraint_expr_eval should pass in NULL for xcontext.
263 */
264static int constraint_expr_eval(struct policydb *policydb,
265 struct context *scontext,
266 struct context *tcontext,
267 struct context *xcontext,
268 struct constraint_expr *cexpr)
269{
270 u32 val1, val2;
271 struct context *c;
272 struct role_datum *r1, *r2;
273 struct mls_level *l1, *l2;
274 struct constraint_expr *e;
275 int s[CEXPR_MAXDEPTH];
276 int sp = -1;
277
278 for (e = cexpr; e; e = e->next) {
279 switch (e->expr_type) {
280 case CEXPR_NOT:
281 BUG_ON(sp < 0);
282 s[sp] = !s[sp];
283 break;
284 case CEXPR_AND:
285 BUG_ON(sp < 1);
286 sp--;
287 s[sp] &= s[sp + 1];
288 break;
289 case CEXPR_OR:
290 BUG_ON(sp < 1);
291 sp--;
292 s[sp] |= s[sp + 1];
293 break;
294 case CEXPR_ATTR:
295 if (sp == (CEXPR_MAXDEPTH - 1))
296 return 0;
297 switch (e->attr) {
298 case CEXPR_USER:
299 val1 = scontext->user;
300 val2 = tcontext->user;
301 break;
302 case CEXPR_TYPE:
303 val1 = scontext->type;
304 val2 = tcontext->type;
305 break;
306 case CEXPR_ROLE:
307 val1 = scontext->role;
308 val2 = tcontext->role;
309 r1 = policydb->role_val_to_struct[val1 - 1];
310 r2 = policydb->role_val_to_struct[val2 - 1];
311 switch (e->op) {
312 case CEXPR_DOM:
313 s[++sp] = ebitmap_get_bit(&r1->dominates,
314 val2 - 1);
315 continue;
316 case CEXPR_DOMBY:
317 s[++sp] = ebitmap_get_bit(&r2->dominates,
318 val1 - 1);
319 continue;
320 case CEXPR_INCOMP:
321 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
322 val2 - 1) &&
323 !ebitmap_get_bit(&r2->dominates,
324 val1 - 1));
325 continue;
326 default:
327 break;
328 }
329 break;
330 case CEXPR_L1L2:
331 l1 = &(scontext->range.level[0]);
332 l2 = &(tcontext->range.level[0]);
333 goto mls_ops;
334 case CEXPR_L1H2:
335 l1 = &(scontext->range.level[0]);
336 l2 = &(tcontext->range.level[1]);
337 goto mls_ops;
338 case CEXPR_H1L2:
339 l1 = &(scontext->range.level[1]);
340 l2 = &(tcontext->range.level[0]);
341 goto mls_ops;
342 case CEXPR_H1H2:
343 l1 = &(scontext->range.level[1]);
344 l2 = &(tcontext->range.level[1]);
345 goto mls_ops;
346 case CEXPR_L1H1:
347 l1 = &(scontext->range.level[0]);
348 l2 = &(scontext->range.level[1]);
349 goto mls_ops;
350 case CEXPR_L2H2:
351 l1 = &(tcontext->range.level[0]);
352 l2 = &(tcontext->range.level[1]);
353 goto mls_ops;
354mls_ops:
355 switch (e->op) {
356 case CEXPR_EQ:
357 s[++sp] = mls_level_eq(l1, l2);
358 continue;
359 case CEXPR_NEQ:
360 s[++sp] = !mls_level_eq(l1, l2);
361 continue;
362 case CEXPR_DOM:
363 s[++sp] = mls_level_dom(l1, l2);
364 continue;
365 case CEXPR_DOMBY:
366 s[++sp] = mls_level_dom(l2, l1);
367 continue;
368 case CEXPR_INCOMP:
369 s[++sp] = mls_level_incomp(l2, l1);
370 continue;
371 default:
372 BUG();
373 return 0;
374 }
375 break;
376 default:
377 BUG();
378 return 0;
379 }
380
381 switch (e->op) {
382 case CEXPR_EQ:
383 s[++sp] = (val1 == val2);
384 break;
385 case CEXPR_NEQ:
386 s[++sp] = (val1 != val2);
387 break;
388 default:
389 BUG();
390 return 0;
391 }
392 break;
393 case CEXPR_NAMES:
394 if (sp == (CEXPR_MAXDEPTH-1))
395 return 0;
396 c = scontext;
397 if (e->attr & CEXPR_TARGET)
398 c = tcontext;
399 else if (e->attr & CEXPR_XTARGET) {
400 c = xcontext;
401 if (!c) {
402 BUG();
403 return 0;
404 }
405 }
406 if (e->attr & CEXPR_USER)
407 val1 = c->user;
408 else if (e->attr & CEXPR_ROLE)
409 val1 = c->role;
410 else if (e->attr & CEXPR_TYPE)
411 val1 = c->type;
412 else {
413 BUG();
414 return 0;
415 }
416
417 switch (e->op) {
418 case CEXPR_EQ:
419 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
420 break;
421 case CEXPR_NEQ:
422 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
423 break;
424 default:
425 BUG();
426 return 0;
427 }
428 break;
429 default:
430 BUG();
431 return 0;
432 }
433 }
434
435 BUG_ON(sp != 0);
436 return s[0];
437}
438
439/*
440 * security_dump_masked_av - dumps masked permissions during
441 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
442 */
443static int dump_masked_av_helper(void *k, void *d, void *args)
444{
445 struct perm_datum *pdatum = d;
446 char **permission_names = args;
447
448 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
449
450 permission_names[pdatum->value - 1] = (char *)k;
451
452 return 0;
453}
454
455static void security_dump_masked_av(struct policydb *policydb,
456 struct context *scontext,
457 struct context *tcontext,
458 u16 tclass,
459 u32 permissions,
460 const char *reason)
461{
462 struct common_datum *common_dat;
463 struct class_datum *tclass_dat;
464 struct audit_buffer *ab;
465 char *tclass_name;
466 char *scontext_name = NULL;
467 char *tcontext_name = NULL;
468 char *permission_names[32];
469 int index;
470 u32 length;
471 bool need_comma = false;
472
473 if (!permissions)
474 return;
475
476 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
477 tclass_dat = policydb->class_val_to_struct[tclass - 1];
478 common_dat = tclass_dat->comdatum;
479
480 /* init permission_names */
481 if (common_dat &&
482 hashtab_map(&common_dat->permissions.table,
483 dump_masked_av_helper, permission_names) < 0)
484 goto out;
485
486 if (hashtab_map(&tclass_dat->permissions.table,
487 dump_masked_av_helper, permission_names) < 0)
488 goto out;
489
490 /* get scontext/tcontext in text form */
491 if (context_struct_to_string(policydb, scontext,
492 &scontext_name, &length) < 0)
493 goto out;
494
495 if (context_struct_to_string(policydb, tcontext,
496 &tcontext_name, &length) < 0)
497 goto out;
498
499 /* audit a message */
500 ab = audit_log_start(audit_context(),
501 GFP_ATOMIC, AUDIT_SELINUX_ERR);
502 if (!ab)
503 goto out;
504
505 audit_log_format(ab, "op=security_compute_av reason=%s "
506 "scontext=%s tcontext=%s tclass=%s perms=",
507 reason, scontext_name, tcontext_name, tclass_name);
508
509 for (index = 0; index < 32; index++) {
510 u32 mask = (1 << index);
511
512 if ((mask & permissions) == 0)
513 continue;
514
515 audit_log_format(ab, "%s%s",
516 need_comma ? "," : "",
517 permission_names[index]
518 ? permission_names[index] : "????");
519 need_comma = true;
520 }
521 audit_log_end(ab);
522out:
523 /* release scontext/tcontext */
524 kfree(tcontext_name);
525 kfree(scontext_name);
526}
527
528/*
529 * security_boundary_permission - drops violated permissions
530 * on boundary constraint.
531 */
532static void type_attribute_bounds_av(struct policydb *policydb,
533 struct context *scontext,
534 struct context *tcontext,
535 u16 tclass,
536 struct av_decision *avd)
537{
538 struct context lo_scontext;
539 struct context lo_tcontext, *tcontextp = tcontext;
540 struct av_decision lo_avd;
541 struct type_datum *source;
542 struct type_datum *target;
543 u32 masked = 0;
544
545 source = policydb->type_val_to_struct[scontext->type - 1];
546 BUG_ON(!source);
547
548 if (!source->bounds)
549 return;
550
551 target = policydb->type_val_to_struct[tcontext->type - 1];
552 BUG_ON(!target);
553
554 memset(&lo_avd, 0, sizeof(lo_avd));
555
556 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
557 lo_scontext.type = source->bounds;
558
559 if (target->bounds) {
560 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
561 lo_tcontext.type = target->bounds;
562 tcontextp = &lo_tcontext;
563 }
564
565 context_struct_compute_av(policydb, &lo_scontext,
566 tcontextp,
567 tclass,
568 &lo_avd,
569 NULL);
570
571 masked = ~lo_avd.allowed & avd->allowed;
572
573 if (likely(!masked))
574 return; /* no masked permission */
575
576 /* mask violated permissions */
577 avd->allowed &= ~masked;
578
579 /* audit masked permissions */
580 security_dump_masked_av(policydb, scontext, tcontext,
581 tclass, masked, "bounds");
582}
583
584/*
585 * flag which drivers have permissions
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 xperms->len = 1;
605}
606
607/*
608 * Compute access vectors and extended permissions based on a context
609 * structure pair for the permissions in a particular class.
610 */
611static void context_struct_compute_av(struct policydb *policydb,
612 struct context *scontext,
613 struct context *tcontext,
614 u16 tclass,
615 struct av_decision *avd,
616 struct extended_perms *xperms)
617{
618 struct constraint_node *constraint;
619 struct role_allow *ra;
620 struct avtab_key avkey;
621 struct avtab_node *node;
622 struct class_datum *tclass_datum;
623 struct ebitmap *sattr, *tattr;
624 struct ebitmap_node *snode, *tnode;
625 unsigned int i, j;
626
627 avd->allowed = 0;
628 avd->auditallow = 0;
629 avd->auditdeny = 0xffffffff;
630 if (xperms) {
631 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
632 xperms->len = 0;
633 }
634
635 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
636 if (printk_ratelimit())
637 pr_warn("SELinux: Invalid class %hu\n", tclass);
638 return;
639 }
640
641 tclass_datum = policydb->class_val_to_struct[tclass - 1];
642
643 /*
644 * If a specific type enforcement rule was defined for
645 * this permission check, then use it.
646 */
647 avkey.target_class = tclass;
648 avkey.specified = AVTAB_AV | AVTAB_XPERMS;
649 sattr = &policydb->type_attr_map_array[scontext->type - 1];
650 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
651 ebitmap_for_each_positive_bit(sattr, snode, i) {
652 ebitmap_for_each_positive_bit(tattr, tnode, j) {
653 avkey.source_type = i + 1;
654 avkey.target_type = j + 1;
655 for (node = avtab_search_node(&policydb->te_avtab,
656 &avkey);
657 node;
658 node = avtab_search_node_next(node, avkey.specified)) {
659 if (node->key.specified == AVTAB_ALLOWED)
660 avd->allowed |= node->datum.u.data;
661 else if (node->key.specified == AVTAB_AUDITALLOW)
662 avd->auditallow |= node->datum.u.data;
663 else if (node->key.specified == AVTAB_AUDITDENY)
664 avd->auditdeny &= node->datum.u.data;
665 else if (xperms && (node->key.specified & AVTAB_XPERMS))
666 services_compute_xperms_drivers(xperms, node);
667 }
668
669 /* Check conditional av table for additional permissions */
670 cond_compute_av(&policydb->te_cond_avtab, &avkey,
671 avd, xperms);
672
673 }
674 }
675
676 /*
677 * Remove any permissions prohibited by a constraint (this includes
678 * the MLS policy).
679 */
680 constraint = tclass_datum->constraints;
681 while (constraint) {
682 if ((constraint->permissions & (avd->allowed)) &&
683 !constraint_expr_eval(policydb, scontext, tcontext, NULL,
684 constraint->expr)) {
685 avd->allowed &= ~(constraint->permissions);
686 }
687 constraint = constraint->next;
688 }
689
690 /*
691 * If checking process transition permission and the
692 * role is changing, then check the (current_role, new_role)
693 * pair.
694 */
695 if (tclass == policydb->process_class &&
696 (avd->allowed & policydb->process_trans_perms) &&
697 scontext->role != tcontext->role) {
698 for (ra = policydb->role_allow; ra; ra = ra->next) {
699 if (scontext->role == ra->role &&
700 tcontext->role == ra->new_role)
701 break;
702 }
703 if (!ra)
704 avd->allowed &= ~policydb->process_trans_perms;
705 }
706
707 /*
708 * If the given source and target types have boundary
709 * constraint, lazy checks have to mask any violated
710 * permission and notice it to userspace via audit.
711 */
712 type_attribute_bounds_av(policydb, scontext, tcontext,
713 tclass, avd);
714}
715
716static int security_validtrans_handle_fail(struct selinux_state *state,
717 struct selinux_policy *policy,
718 struct sidtab_entry *oentry,
719 struct sidtab_entry *nentry,
720 struct sidtab_entry *tentry,
721 u16 tclass)
722{
723 struct policydb *p = &policy->policydb;
724 struct sidtab *sidtab = policy->sidtab;
725 char *o = NULL, *n = NULL, *t = NULL;
726 u32 olen, nlen, tlen;
727
728 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
729 goto out;
730 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
731 goto out;
732 if (sidtab_entry_to_string(p, sidtab, tentry, &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 selinux_policy *policy;
753 struct policydb *policydb;
754 struct sidtab *sidtab;
755 struct sidtab_entry *oentry;
756 struct sidtab_entry *nentry;
757 struct sidtab_entry *tentry;
758 struct class_datum *tclass_datum;
759 struct constraint_node *constraint;
760 u16 tclass;
761 int rc = 0;
762
763
764 if (!selinux_initialized(state))
765 return 0;
766
767 rcu_read_lock();
768
769 policy = rcu_dereference(state->policy);
770 policydb = &policy->policydb;
771 sidtab = policy->sidtab;
772
773 if (!user)
774 tclass = unmap_class(&policy->map, orig_tclass);
775 else
776 tclass = orig_tclass;
777
778 if (!tclass || tclass > policydb->p_classes.nprim) {
779 rc = -EINVAL;
780 goto out;
781 }
782 tclass_datum = policydb->class_val_to_struct[tclass - 1];
783
784 oentry = sidtab_search_entry(sidtab, oldsid);
785 if (!oentry) {
786 pr_err("SELinux: %s: unrecognized SID %d\n",
787 __func__, oldsid);
788 rc = -EINVAL;
789 goto out;
790 }
791
792 nentry = sidtab_search_entry(sidtab, newsid);
793 if (!nentry) {
794 pr_err("SELinux: %s: unrecognized SID %d\n",
795 __func__, newsid);
796 rc = -EINVAL;
797 goto out;
798 }
799
800 tentry = sidtab_search_entry(sidtab, tasksid);
801 if (!tentry) {
802 pr_err("SELinux: %s: unrecognized SID %d\n",
803 __func__, tasksid);
804 rc = -EINVAL;
805 goto out;
806 }
807
808 constraint = tclass_datum->validatetrans;
809 while (constraint) {
810 if (!constraint_expr_eval(policydb, &oentry->context,
811 &nentry->context, &tentry->context,
812 constraint->expr)) {
813 if (user)
814 rc = -EPERM;
815 else
816 rc = security_validtrans_handle_fail(state,
817 policy,
818 oentry,
819 nentry,
820 tentry,
821 tclass);
822 goto out;
823 }
824 constraint = constraint->next;
825 }
826
827out:
828 rcu_read_unlock();
829 return rc;
830}
831
832int security_validate_transition_user(struct selinux_state *state,
833 u32 oldsid, u32 newsid, u32 tasksid,
834 u16 tclass)
835{
836 return security_compute_validatetrans(state, oldsid, newsid, tasksid,
837 tclass, true);
838}
839
840int security_validate_transition(struct selinux_state *state,
841 u32 oldsid, u32 newsid, u32 tasksid,
842 u16 orig_tclass)
843{
844 return security_compute_validatetrans(state, oldsid, newsid, tasksid,
845 orig_tclass, false);
846}
847
848/*
849 * security_bounded_transition - check whether the given
850 * transition is directed to bounded, or not.
851 * It returns 0, if @newsid is bounded by @oldsid.
852 * Otherwise, it returns error code.
853 *
854 * @state: SELinux state
855 * @oldsid : current security identifier
856 * @newsid : destinated security identifier
857 */
858int security_bounded_transition(struct selinux_state *state,
859 u32 old_sid, u32 new_sid)
860{
861 struct selinux_policy *policy;
862 struct policydb *policydb;
863 struct sidtab *sidtab;
864 struct sidtab_entry *old_entry, *new_entry;
865 struct type_datum *type;
866 int index;
867 int rc;
868
869 if (!selinux_initialized(state))
870 return 0;
871
872 rcu_read_lock();
873 policy = rcu_dereference(state->policy);
874 policydb = &policy->policydb;
875 sidtab = policy->sidtab;
876
877 rc = -EINVAL;
878 old_entry = sidtab_search_entry(sidtab, old_sid);
879 if (!old_entry) {
880 pr_err("SELinux: %s: unrecognized SID %u\n",
881 __func__, old_sid);
882 goto out;
883 }
884
885 rc = -EINVAL;
886 new_entry = sidtab_search_entry(sidtab, new_sid);
887 if (!new_entry) {
888 pr_err("SELinux: %s: unrecognized SID %u\n",
889 __func__, new_sid);
890 goto out;
891 }
892
893 rc = 0;
894 /* type/domain unchanged */
895 if (old_entry->context.type == new_entry->context.type)
896 goto out;
897
898 index = new_entry->context.type;
899 while (true) {
900 type = policydb->type_val_to_struct[index - 1];
901 BUG_ON(!type);
902
903 /* not bounded anymore */
904 rc = -EPERM;
905 if (!type->bounds)
906 break;
907
908 /* @newsid is bounded by @oldsid */
909 rc = 0;
910 if (type->bounds == old_entry->context.type)
911 break;
912
913 index = type->bounds;
914 }
915
916 if (rc) {
917 char *old_name = NULL;
918 char *new_name = NULL;
919 u32 length;
920
921 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
922 &old_name, &length) &&
923 !sidtab_entry_to_string(policydb, sidtab, new_entry,
924 &new_name, &length)) {
925 audit_log(audit_context(),
926 GFP_ATOMIC, AUDIT_SELINUX_ERR,
927 "op=security_bounded_transition "
928 "seresult=denied "
929 "oldcontext=%s newcontext=%s",
930 old_name, new_name);
931 }
932 kfree(new_name);
933 kfree(old_name);
934 }
935out:
936 rcu_read_unlock();
937
938 return rc;
939}
940
941static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
942{
943 avd->allowed = 0;
944 avd->auditallow = 0;
945 avd->auditdeny = 0xffffffff;
946 if (policy)
947 avd->seqno = policy->latest_granting;
948 else
949 avd->seqno = 0;
950 avd->flags = 0;
951}
952
953void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
954 struct avtab_node *node)
955{
956 unsigned int i;
957
958 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
959 if (xpermd->driver != node->datum.u.xperms->driver)
960 return;
961 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
962 if (!security_xperm_test(node->datum.u.xperms->perms.p,
963 xpermd->driver))
964 return;
965 } else {
966 BUG();
967 }
968
969 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
970 xpermd->used |= XPERMS_ALLOWED;
971 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
972 memset(xpermd->allowed->p, 0xff,
973 sizeof(xpermd->allowed->p));
974 }
975 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
976 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
977 xpermd->allowed->p[i] |=
978 node->datum.u.xperms->perms.p[i];
979 }
980 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
981 xpermd->used |= XPERMS_AUDITALLOW;
982 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
983 memset(xpermd->auditallow->p, 0xff,
984 sizeof(xpermd->auditallow->p));
985 }
986 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
987 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
988 xpermd->auditallow->p[i] |=
989 node->datum.u.xperms->perms.p[i];
990 }
991 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
992 xpermd->used |= XPERMS_DONTAUDIT;
993 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
994 memset(xpermd->dontaudit->p, 0xff,
995 sizeof(xpermd->dontaudit->p));
996 }
997 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
998 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
999 xpermd->dontaudit->p[i] |=
1000 node->datum.u.xperms->perms.p[i];
1001 }
1002 } else {
1003 BUG();
1004 }
1005}
1006
1007void security_compute_xperms_decision(struct selinux_state *state,
1008 u32 ssid,
1009 u32 tsid,
1010 u16 orig_tclass,
1011 u8 driver,
1012 struct extended_perms_decision *xpermd)
1013{
1014 struct selinux_policy *policy;
1015 struct policydb *policydb;
1016 struct sidtab *sidtab;
1017 u16 tclass;
1018 struct context *scontext, *tcontext;
1019 struct avtab_key avkey;
1020 struct avtab_node *node;
1021 struct ebitmap *sattr, *tattr;
1022 struct ebitmap_node *snode, *tnode;
1023 unsigned int i, j;
1024
1025 xpermd->driver = driver;
1026 xpermd->used = 0;
1027 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1028 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1029 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1030
1031 rcu_read_lock();
1032 if (!selinux_initialized(state))
1033 goto allow;
1034
1035 policy = rcu_dereference(state->policy);
1036 policydb = &policy->policydb;
1037 sidtab = policy->sidtab;
1038
1039 scontext = sidtab_search(sidtab, ssid);
1040 if (!scontext) {
1041 pr_err("SELinux: %s: unrecognized SID %d\n",
1042 __func__, ssid);
1043 goto out;
1044 }
1045
1046 tcontext = sidtab_search(sidtab, tsid);
1047 if (!tcontext) {
1048 pr_err("SELinux: %s: unrecognized SID %d\n",
1049 __func__, tsid);
1050 goto out;
1051 }
1052
1053 tclass = unmap_class(&policy->map, orig_tclass);
1054 if (unlikely(orig_tclass && !tclass)) {
1055 if (policydb->allow_unknown)
1056 goto allow;
1057 goto out;
1058 }
1059
1060
1061 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1062 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1063 goto out;
1064 }
1065
1066 avkey.target_class = tclass;
1067 avkey.specified = AVTAB_XPERMS;
1068 sattr = &policydb->type_attr_map_array[scontext->type - 1];
1069 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1070 ebitmap_for_each_positive_bit(sattr, snode, i) {
1071 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1072 avkey.source_type = i + 1;
1073 avkey.target_type = j + 1;
1074 for (node = avtab_search_node(&policydb->te_avtab,
1075 &avkey);
1076 node;
1077 node = avtab_search_node_next(node, avkey.specified))
1078 services_compute_xperms_decision(xpermd, node);
1079
1080 cond_compute_xperms(&policydb->te_cond_avtab,
1081 &avkey, xpermd);
1082 }
1083 }
1084out:
1085 rcu_read_unlock();
1086 return;
1087allow:
1088 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1089 goto out;
1090}
1091
1092/**
1093 * security_compute_av - Compute access vector decisions.
1094 * @state: SELinux state
1095 * @ssid: source security identifier
1096 * @tsid: target security identifier
1097 * @orig_tclass: target security class
1098 * @avd: access vector decisions
1099 * @xperms: extended permissions
1100 *
1101 * Compute a set of access vector decisions based on the
1102 * SID pair (@ssid, @tsid) for the permissions in @tclass.
1103 */
1104void security_compute_av(struct selinux_state *state,
1105 u32 ssid,
1106 u32 tsid,
1107 u16 orig_tclass,
1108 struct av_decision *avd,
1109 struct extended_perms *xperms)
1110{
1111 struct selinux_policy *policy;
1112 struct policydb *policydb;
1113 struct sidtab *sidtab;
1114 u16 tclass;
1115 struct context *scontext = NULL, *tcontext = NULL;
1116
1117 rcu_read_lock();
1118 policy = rcu_dereference(state->policy);
1119 avd_init(policy, avd);
1120 xperms->len = 0;
1121 if (!selinux_initialized(state))
1122 goto allow;
1123
1124 policydb = &policy->policydb;
1125 sidtab = policy->sidtab;
1126
1127 scontext = sidtab_search(sidtab, ssid);
1128 if (!scontext) {
1129 pr_err("SELinux: %s: unrecognized SID %d\n",
1130 __func__, ssid);
1131 goto out;
1132 }
1133
1134 /* permissive domain? */
1135 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1136 avd->flags |= AVD_FLAGS_PERMISSIVE;
1137
1138 tcontext = sidtab_search(sidtab, tsid);
1139 if (!tcontext) {
1140 pr_err("SELinux: %s: unrecognized SID %d\n",
1141 __func__, tsid);
1142 goto out;
1143 }
1144
1145 tclass = unmap_class(&policy->map, orig_tclass);
1146 if (unlikely(orig_tclass && !tclass)) {
1147 if (policydb->allow_unknown)
1148 goto allow;
1149 goto out;
1150 }
1151 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1152 xperms);
1153 map_decision(&policy->map, orig_tclass, avd,
1154 policydb->allow_unknown);
1155out:
1156 rcu_read_unlock();
1157 return;
1158allow:
1159 avd->allowed = 0xffffffff;
1160 goto out;
1161}
1162
1163void security_compute_av_user(struct selinux_state *state,
1164 u32 ssid,
1165 u32 tsid,
1166 u16 tclass,
1167 struct av_decision *avd)
1168{
1169 struct selinux_policy *policy;
1170 struct policydb *policydb;
1171 struct sidtab *sidtab;
1172 struct context *scontext = NULL, *tcontext = NULL;
1173
1174 rcu_read_lock();
1175 policy = rcu_dereference(state->policy);
1176 avd_init(policy, avd);
1177 if (!selinux_initialized(state))
1178 goto allow;
1179
1180 policydb = &policy->policydb;
1181 sidtab = policy->sidtab;
1182
1183 scontext = sidtab_search(sidtab, ssid);
1184 if (!scontext) {
1185 pr_err("SELinux: %s: unrecognized SID %d\n",
1186 __func__, ssid);
1187 goto out;
1188 }
1189
1190 /* permissive domain? */
1191 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1192 avd->flags |= AVD_FLAGS_PERMISSIVE;
1193
1194 tcontext = sidtab_search(sidtab, tsid);
1195 if (!tcontext) {
1196 pr_err("SELinux: %s: unrecognized SID %d\n",
1197 __func__, tsid);
1198 goto out;
1199 }
1200
1201 if (unlikely(!tclass)) {
1202 if (policydb->allow_unknown)
1203 goto allow;
1204 goto out;
1205 }
1206
1207 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1208 NULL);
1209 out:
1210 rcu_read_unlock();
1211 return;
1212allow:
1213 avd->allowed = 0xffffffff;
1214 goto out;
1215}
1216
1217/*
1218 * Write the security context string representation of
1219 * the context structure `context' into a dynamically
1220 * allocated string of the correct size. Set `*scontext'
1221 * to point to this string and set `*scontext_len' to
1222 * the length of the string.
1223 */
1224static int context_struct_to_string(struct policydb *p,
1225 struct context *context,
1226 char **scontext, u32 *scontext_len)
1227{
1228 char *scontextp;
1229
1230 if (scontext)
1231 *scontext = NULL;
1232 *scontext_len = 0;
1233
1234 if (context->len) {
1235 *scontext_len = context->len;
1236 if (scontext) {
1237 *scontext = kstrdup(context->str, GFP_ATOMIC);
1238 if (!(*scontext))
1239 return -ENOMEM;
1240 }
1241 return 0;
1242 }
1243
1244 /* Compute the size of the context. */
1245 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1246 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1247 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1248 *scontext_len += mls_compute_context_len(p, context);
1249
1250 if (!scontext)
1251 return 0;
1252
1253 /* Allocate space for the context; caller must free this space. */
1254 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1255 if (!scontextp)
1256 return -ENOMEM;
1257 *scontext = scontextp;
1258
1259 /*
1260 * Copy the user name, role name and type name into the context.
1261 */
1262 scontextp += sprintf(scontextp, "%s:%s:%s",
1263 sym_name(p, SYM_USERS, context->user - 1),
1264 sym_name(p, SYM_ROLES, context->role - 1),
1265 sym_name(p, SYM_TYPES, context->type - 1));
1266
1267 mls_sid_to_context(p, context, &scontextp);
1268
1269 *scontextp = 0;
1270
1271 return 0;
1272}
1273
1274static int sidtab_entry_to_string(struct policydb *p,
1275 struct sidtab *sidtab,
1276 struct sidtab_entry *entry,
1277 char **scontext, u32 *scontext_len)
1278{
1279 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1280
1281 if (rc != -ENOENT)
1282 return rc;
1283
1284 rc = context_struct_to_string(p, &entry->context, scontext,
1285 scontext_len);
1286 if (!rc && scontext)
1287 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1288 return rc;
1289}
1290
1291#include "initial_sid_to_string.h"
1292
1293int security_sidtab_hash_stats(struct selinux_state *state, char *page)
1294{
1295 struct selinux_policy *policy;
1296 int rc;
1297
1298 if (!selinux_initialized(state)) {
1299 pr_err("SELinux: %s: called before initial load_policy\n",
1300 __func__);
1301 return -EINVAL;
1302 }
1303
1304 rcu_read_lock();
1305 policy = rcu_dereference(state->policy);
1306 rc = sidtab_hash_stats(policy->sidtab, page);
1307 rcu_read_unlock();
1308
1309 return rc;
1310}
1311
1312const char *security_get_initial_sid_context(u32 sid)
1313{
1314 if (unlikely(sid > SECINITSID_NUM))
1315 return NULL;
1316 return initial_sid_to_string[sid];
1317}
1318
1319static int security_sid_to_context_core(struct selinux_state *state,
1320 u32 sid, char **scontext,
1321 u32 *scontext_len, int force,
1322 int only_invalid)
1323{
1324 struct selinux_policy *policy;
1325 struct policydb *policydb;
1326 struct sidtab *sidtab;
1327 struct sidtab_entry *entry;
1328 int rc = 0;
1329
1330 if (scontext)
1331 *scontext = NULL;
1332 *scontext_len = 0;
1333
1334 if (!selinux_initialized(state)) {
1335 if (sid <= SECINITSID_NUM) {
1336 char *scontextp;
1337 const char *s = initial_sid_to_string[sid];
1338
1339 if (!s)
1340 return -EINVAL;
1341 *scontext_len = strlen(s) + 1;
1342 if (!scontext)
1343 return 0;
1344 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1345 if (!scontextp)
1346 return -ENOMEM;
1347 *scontext = scontextp;
1348 return 0;
1349 }
1350 pr_err("SELinux: %s: called before initial "
1351 "load_policy on unknown SID %d\n", __func__, sid);
1352 return -EINVAL;
1353 }
1354 rcu_read_lock();
1355 policy = rcu_dereference(state->policy);
1356 policydb = &policy->policydb;
1357 sidtab = policy->sidtab;
1358
1359 if (force)
1360 entry = sidtab_search_entry_force(sidtab, sid);
1361 else
1362 entry = sidtab_search_entry(sidtab, sid);
1363 if (!entry) {
1364 pr_err("SELinux: %s: unrecognized SID %d\n",
1365 __func__, sid);
1366 rc = -EINVAL;
1367 goto out_unlock;
1368 }
1369 if (only_invalid && !entry->context.len)
1370 goto out_unlock;
1371
1372 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1373 scontext_len);
1374
1375out_unlock:
1376 rcu_read_unlock();
1377 return rc;
1378
1379}
1380
1381/**
1382 * security_sid_to_context - Obtain a context for a given SID.
1383 * @state: SELinux state
1384 * @sid: security identifier, SID
1385 * @scontext: security context
1386 * @scontext_len: length in bytes
1387 *
1388 * Write the string representation of the context associated with @sid
1389 * into a dynamically allocated string of the correct size. Set @scontext
1390 * to point to this string and set @scontext_len to the length of the string.
1391 */
1392int security_sid_to_context(struct selinux_state *state,
1393 u32 sid, char **scontext, u32 *scontext_len)
1394{
1395 return security_sid_to_context_core(state, sid, scontext,
1396 scontext_len, 0, 0);
1397}
1398
1399int security_sid_to_context_force(struct selinux_state *state, u32 sid,
1400 char **scontext, u32 *scontext_len)
1401{
1402 return security_sid_to_context_core(state, sid, scontext,
1403 scontext_len, 1, 0);
1404}
1405
1406/**
1407 * security_sid_to_context_inval - Obtain a context for a given SID if it
1408 * is invalid.
1409 * @state: SELinux state
1410 * @sid: security identifier, SID
1411 * @scontext: security context
1412 * @scontext_len: length in bytes
1413 *
1414 * Write the string representation of the context associated with @sid
1415 * into a dynamically allocated string of the correct size, but only if the
1416 * context is invalid in the current policy. Set @scontext to point to
1417 * this string (or NULL if the context is valid) and set @scontext_len to
1418 * the length of the string (or 0 if the context is valid).
1419 */
1420int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
1421 char **scontext, u32 *scontext_len)
1422{
1423 return security_sid_to_context_core(state, sid, scontext,
1424 scontext_len, 1, 1);
1425}
1426
1427/*
1428 * Caveat: Mutates scontext.
1429 */
1430static int string_to_context_struct(struct policydb *pol,
1431 struct sidtab *sidtabp,
1432 char *scontext,
1433 struct context *ctx,
1434 u32 def_sid)
1435{
1436 struct role_datum *role;
1437 struct type_datum *typdatum;
1438 struct user_datum *usrdatum;
1439 char *scontextp, *p, oldc;
1440 int rc = 0;
1441
1442 context_init(ctx);
1443
1444 /* Parse the security context. */
1445
1446 rc = -EINVAL;
1447 scontextp = scontext;
1448
1449 /* Extract the user. */
1450 p = scontextp;
1451 while (*p && *p != ':')
1452 p++;
1453
1454 if (*p == 0)
1455 goto out;
1456
1457 *p++ = 0;
1458
1459 usrdatum = symtab_search(&pol->p_users, scontextp);
1460 if (!usrdatum)
1461 goto out;
1462
1463 ctx->user = usrdatum->value;
1464
1465 /* Extract role. */
1466 scontextp = p;
1467 while (*p && *p != ':')
1468 p++;
1469
1470 if (*p == 0)
1471 goto out;
1472
1473 *p++ = 0;
1474
1475 role = symtab_search(&pol->p_roles, scontextp);
1476 if (!role)
1477 goto out;
1478 ctx->role = role->value;
1479
1480 /* Extract type. */
1481 scontextp = p;
1482 while (*p && *p != ':')
1483 p++;
1484 oldc = *p;
1485 *p++ = 0;
1486
1487 typdatum = symtab_search(&pol->p_types, scontextp);
1488 if (!typdatum || typdatum->attribute)
1489 goto out;
1490
1491 ctx->type = typdatum->value;
1492
1493 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1494 if (rc)
1495 goto out;
1496
1497 /* Check the validity of the new context. */
1498 rc = -EINVAL;
1499 if (!policydb_context_isvalid(pol, ctx))
1500 goto out;
1501 rc = 0;
1502out:
1503 if (rc)
1504 context_destroy(ctx);
1505 return rc;
1506}
1507
1508static int security_context_to_sid_core(struct selinux_state *state,
1509 const char *scontext, u32 scontext_len,
1510 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1511 int force)
1512{
1513 struct selinux_policy *policy;
1514 struct policydb *policydb;
1515 struct sidtab *sidtab;
1516 char *scontext2, *str = NULL;
1517 struct context context;
1518 int rc = 0;
1519
1520 /* An empty security context is never valid. */
1521 if (!scontext_len)
1522 return -EINVAL;
1523
1524 /* Copy the string to allow changes and ensure a NUL terminator */
1525 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1526 if (!scontext2)
1527 return -ENOMEM;
1528
1529 if (!selinux_initialized(state)) {
1530 int i;
1531
1532 for (i = 1; i < SECINITSID_NUM; i++) {
1533 const char *s = initial_sid_to_string[i];
1534
1535 if (s && !strcmp(s, scontext2)) {
1536 *sid = i;
1537 goto out;
1538 }
1539 }
1540 *sid = SECINITSID_KERNEL;
1541 goto out;
1542 }
1543 *sid = SECSID_NULL;
1544
1545 if (force) {
1546 /* Save another copy for storing in uninterpreted form */
1547 rc = -ENOMEM;
1548 str = kstrdup(scontext2, gfp_flags);
1549 if (!str)
1550 goto out;
1551 }
1552retry:
1553 rcu_read_lock();
1554 policy = rcu_dereference(state->policy);
1555 policydb = &policy->policydb;
1556 sidtab = policy->sidtab;
1557 rc = string_to_context_struct(policydb, sidtab, scontext2,
1558 &context, def_sid);
1559 if (rc == -EINVAL && force) {
1560 context.str = str;
1561 context.len = strlen(str) + 1;
1562 str = NULL;
1563 } else if (rc)
1564 goto out_unlock;
1565 rc = sidtab_context_to_sid(sidtab, &context, sid);
1566 if (rc == -ESTALE) {
1567 rcu_read_unlock();
1568 if (context.str) {
1569 str = context.str;
1570 context.str = NULL;
1571 }
1572 context_destroy(&context);
1573 goto retry;
1574 }
1575 context_destroy(&context);
1576out_unlock:
1577 rcu_read_unlock();
1578out:
1579 kfree(scontext2);
1580 kfree(str);
1581 return rc;
1582}
1583
1584/**
1585 * security_context_to_sid - Obtain a SID for a given security context.
1586 * @state: SELinux state
1587 * @scontext: security context
1588 * @scontext_len: length in bytes
1589 * @sid: security identifier, SID
1590 * @gfp: context for the allocation
1591 *
1592 * Obtains a SID associated with the security context that
1593 * has the string representation specified by @scontext.
1594 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1595 * memory is available, or 0 on success.
1596 */
1597int security_context_to_sid(struct selinux_state *state,
1598 const char *scontext, u32 scontext_len, u32 *sid,
1599 gfp_t gfp)
1600{
1601 return security_context_to_sid_core(state, scontext, scontext_len,
1602 sid, SECSID_NULL, gfp, 0);
1603}
1604
1605int security_context_str_to_sid(struct selinux_state *state,
1606 const char *scontext, u32 *sid, gfp_t gfp)
1607{
1608 return security_context_to_sid(state, scontext, strlen(scontext),
1609 sid, gfp);
1610}
1611
1612/**
1613 * security_context_to_sid_default - Obtain a SID for a given security context,
1614 * falling back to specified default if needed.
1615 *
1616 * @state: SELinux state
1617 * @scontext: security context
1618 * @scontext_len: length in bytes
1619 * @sid: security identifier, SID
1620 * @def_sid: default SID to assign on error
1621 * @gfp_flags: the allocator get-free-page (GFP) flags
1622 *
1623 * Obtains a SID associated with the security context that
1624 * has the string representation specified by @scontext.
1625 * The default SID is passed to the MLS layer to be used to allow
1626 * kernel labeling of the MLS field if the MLS field is not present
1627 * (for upgrading to MLS without full relabel).
1628 * Implicitly forces adding of the context even if it cannot be mapped yet.
1629 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1630 * memory is available, or 0 on success.
1631 */
1632int security_context_to_sid_default(struct selinux_state *state,
1633 const char *scontext, u32 scontext_len,
1634 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1635{
1636 return security_context_to_sid_core(state, scontext, scontext_len,
1637 sid, def_sid, gfp_flags, 1);
1638}
1639
1640int security_context_to_sid_force(struct selinux_state *state,
1641 const char *scontext, u32 scontext_len,
1642 u32 *sid)
1643{
1644 return security_context_to_sid_core(state, scontext, scontext_len,
1645 sid, SECSID_NULL, GFP_KERNEL, 1);
1646}
1647
1648static int compute_sid_handle_invalid_context(
1649 struct selinux_state *state,
1650 struct selinux_policy *policy,
1651 struct sidtab_entry *sentry,
1652 struct sidtab_entry *tentry,
1653 u16 tclass,
1654 struct context *newcontext)
1655{
1656 struct policydb *policydb = &policy->policydb;
1657 struct sidtab *sidtab = policy->sidtab;
1658 char *s = NULL, *t = NULL, *n = NULL;
1659 u32 slen, tlen, nlen;
1660 struct audit_buffer *ab;
1661
1662 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1663 goto out;
1664 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1665 goto out;
1666 if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1667 goto out;
1668 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1669 if (!ab)
1670 goto out;
1671 audit_log_format(ab,
1672 "op=security_compute_sid invalid_context=");
1673 /* no need to record the NUL with untrusted strings */
1674 audit_log_n_untrustedstring(ab, n, nlen - 1);
1675 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1676 s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1677 audit_log_end(ab);
1678out:
1679 kfree(s);
1680 kfree(t);
1681 kfree(n);
1682 if (!enforcing_enabled(state))
1683 return 0;
1684 return -EACCES;
1685}
1686
1687static void filename_compute_type(struct policydb *policydb,
1688 struct context *newcontext,
1689 u32 stype, u32 ttype, u16 tclass,
1690 const char *objname)
1691{
1692 struct filename_trans_key ft;
1693 struct filename_trans_datum *datum;
1694
1695 /*
1696 * Most filename trans rules are going to live in specific directories
1697 * like /dev or /var/run. This bitmap will quickly skip rule searches
1698 * if the ttype does not contain any rules.
1699 */
1700 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1701 return;
1702
1703 ft.ttype = ttype;
1704 ft.tclass = tclass;
1705 ft.name = objname;
1706
1707 datum = policydb_filenametr_search(policydb, &ft);
1708 while (datum) {
1709 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1710 newcontext->type = datum->otype;
1711 return;
1712 }
1713 datum = datum->next;
1714 }
1715}
1716
1717static int security_compute_sid(struct selinux_state *state,
1718 u32 ssid,
1719 u32 tsid,
1720 u16 orig_tclass,
1721 u32 specified,
1722 const char *objname,
1723 u32 *out_sid,
1724 bool kern)
1725{
1726 struct selinux_policy *policy;
1727 struct policydb *policydb;
1728 struct sidtab *sidtab;
1729 struct class_datum *cladatum;
1730 struct context *scontext, *tcontext, newcontext;
1731 struct sidtab_entry *sentry, *tentry;
1732 struct avtab_key avkey;
1733 struct avtab_datum *avdatum;
1734 struct avtab_node *node;
1735 u16 tclass;
1736 int rc = 0;
1737 bool sock;
1738
1739 if (!selinux_initialized(state)) {
1740 switch (orig_tclass) {
1741 case SECCLASS_PROCESS: /* kernel value */
1742 *out_sid = ssid;
1743 break;
1744 default:
1745 *out_sid = tsid;
1746 break;
1747 }
1748 goto out;
1749 }
1750
1751retry:
1752 cladatum = NULL;
1753 context_init(&newcontext);
1754
1755 rcu_read_lock();
1756
1757 policy = rcu_dereference(state->policy);
1758
1759 if (kern) {
1760 tclass = unmap_class(&policy->map, orig_tclass);
1761 sock = security_is_socket_class(orig_tclass);
1762 } else {
1763 tclass = orig_tclass;
1764 sock = security_is_socket_class(map_class(&policy->map,
1765 tclass));
1766 }
1767
1768 policydb = &policy->policydb;
1769 sidtab = policy->sidtab;
1770
1771 sentry = sidtab_search_entry(sidtab, ssid);
1772 if (!sentry) {
1773 pr_err("SELinux: %s: unrecognized SID %d\n",
1774 __func__, ssid);
1775 rc = -EINVAL;
1776 goto out_unlock;
1777 }
1778 tentry = sidtab_search_entry(sidtab, tsid);
1779 if (!tentry) {
1780 pr_err("SELinux: %s: unrecognized SID %d\n",
1781 __func__, tsid);
1782 rc = -EINVAL;
1783 goto out_unlock;
1784 }
1785
1786 scontext = &sentry->context;
1787 tcontext = &tentry->context;
1788
1789 if (tclass && tclass <= policydb->p_classes.nprim)
1790 cladatum = policydb->class_val_to_struct[tclass - 1];
1791
1792 /* Set the user identity. */
1793 switch (specified) {
1794 case AVTAB_TRANSITION:
1795 case AVTAB_CHANGE:
1796 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1797 newcontext.user = tcontext->user;
1798 } else {
1799 /* notice this gets both DEFAULT_SOURCE and unset */
1800 /* Use the process user identity. */
1801 newcontext.user = scontext->user;
1802 }
1803 break;
1804 case AVTAB_MEMBER:
1805 /* Use the related object owner. */
1806 newcontext.user = tcontext->user;
1807 break;
1808 }
1809
1810 /* Set the role to default values. */
1811 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1812 newcontext.role = scontext->role;
1813 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1814 newcontext.role = tcontext->role;
1815 } else {
1816 if ((tclass == policydb->process_class) || sock)
1817 newcontext.role = scontext->role;
1818 else
1819 newcontext.role = OBJECT_R_VAL;
1820 }
1821
1822 /* Set the type to default values. */
1823 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1824 newcontext.type = scontext->type;
1825 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1826 newcontext.type = tcontext->type;
1827 } else {
1828 if ((tclass == policydb->process_class) || sock) {
1829 /* Use the type of process. */
1830 newcontext.type = scontext->type;
1831 } else {
1832 /* Use the type of the related object. */
1833 newcontext.type = tcontext->type;
1834 }
1835 }
1836
1837 /* Look for a type transition/member/change rule. */
1838 avkey.source_type = scontext->type;
1839 avkey.target_type = tcontext->type;
1840 avkey.target_class = tclass;
1841 avkey.specified = specified;
1842 avdatum = avtab_search(&policydb->te_avtab, &avkey);
1843
1844 /* If no permanent rule, also check for enabled conditional rules */
1845 if (!avdatum) {
1846 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1847 for (; node; node = avtab_search_node_next(node, specified)) {
1848 if (node->key.specified & AVTAB_ENABLED) {
1849 avdatum = &node->datum;
1850 break;
1851 }
1852 }
1853 }
1854
1855 if (avdatum) {
1856 /* Use the type from the type transition/member/change rule. */
1857 newcontext.type = avdatum->u.data;
1858 }
1859
1860 /* if we have a objname this is a file trans check so check those rules */
1861 if (objname)
1862 filename_compute_type(policydb, &newcontext, scontext->type,
1863 tcontext->type, tclass, objname);
1864
1865 /* Check for class-specific changes. */
1866 if (specified & AVTAB_TRANSITION) {
1867 /* Look for a role transition rule. */
1868 struct role_trans_datum *rtd;
1869 struct role_trans_key rtk = {
1870 .role = scontext->role,
1871 .type = tcontext->type,
1872 .tclass = tclass,
1873 };
1874
1875 rtd = policydb_roletr_search(policydb, &rtk);
1876 if (rtd)
1877 newcontext.role = rtd->new_role;
1878 }
1879
1880 /* Set the MLS attributes.
1881 This is done last because it may allocate memory. */
1882 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1883 &newcontext, sock);
1884 if (rc)
1885 goto out_unlock;
1886
1887 /* Check the validity of the context. */
1888 if (!policydb_context_isvalid(policydb, &newcontext)) {
1889 rc = compute_sid_handle_invalid_context(state, policy, sentry,
1890 tentry, tclass,
1891 &newcontext);
1892 if (rc)
1893 goto out_unlock;
1894 }
1895 /* Obtain the sid for the context. */
1896 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1897 if (rc == -ESTALE) {
1898 rcu_read_unlock();
1899 context_destroy(&newcontext);
1900 goto retry;
1901 }
1902out_unlock:
1903 rcu_read_unlock();
1904 context_destroy(&newcontext);
1905out:
1906 return rc;
1907}
1908
1909/**
1910 * security_transition_sid - Compute the SID for a new subject/object.
1911 * @state: SELinux state
1912 * @ssid: source security identifier
1913 * @tsid: target security identifier
1914 * @tclass: target security class
1915 * @qstr: object name
1916 * @out_sid: security identifier for new subject/object
1917 *
1918 * Compute a SID to use for labeling a new subject or object in the
1919 * class @tclass based on a SID pair (@ssid, @tsid).
1920 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1921 * if insufficient memory is available, or %0 if the new SID was
1922 * computed successfully.
1923 */
1924int security_transition_sid(struct selinux_state *state,
1925 u32 ssid, u32 tsid, u16 tclass,
1926 const struct qstr *qstr, u32 *out_sid)
1927{
1928 return security_compute_sid(state, ssid, tsid, tclass,
1929 AVTAB_TRANSITION,
1930 qstr ? qstr->name : NULL, out_sid, true);
1931}
1932
1933int security_transition_sid_user(struct selinux_state *state,
1934 u32 ssid, u32 tsid, u16 tclass,
1935 const char *objname, u32 *out_sid)
1936{
1937 return security_compute_sid(state, ssid, tsid, tclass,
1938 AVTAB_TRANSITION,
1939 objname, out_sid, false);
1940}
1941
1942/**
1943 * security_member_sid - Compute the SID for member selection.
1944 * @state: SELinux state
1945 * @ssid: source security identifier
1946 * @tsid: target security identifier
1947 * @tclass: target security class
1948 * @out_sid: security identifier for selected member
1949 *
1950 * Compute a SID to use when selecting a member of a polyinstantiated
1951 * object of class @tclass based on a SID pair (@ssid, @tsid).
1952 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1953 * if insufficient memory is available, or %0 if the SID was
1954 * computed successfully.
1955 */
1956int security_member_sid(struct selinux_state *state,
1957 u32 ssid,
1958 u32 tsid,
1959 u16 tclass,
1960 u32 *out_sid)
1961{
1962 return security_compute_sid(state, ssid, tsid, tclass,
1963 AVTAB_MEMBER, NULL,
1964 out_sid, false);
1965}
1966
1967/**
1968 * security_change_sid - Compute the SID for object relabeling.
1969 * @state: SELinux state
1970 * @ssid: source security identifier
1971 * @tsid: target security identifier
1972 * @tclass: target security class
1973 * @out_sid: security identifier for selected member
1974 *
1975 * Compute a SID to use for relabeling an object of class @tclass
1976 * based on a SID pair (@ssid, @tsid).
1977 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1978 * if insufficient memory is available, or %0 if the SID was
1979 * computed successfully.
1980 */
1981int security_change_sid(struct selinux_state *state,
1982 u32 ssid,
1983 u32 tsid,
1984 u16 tclass,
1985 u32 *out_sid)
1986{
1987 return security_compute_sid(state,
1988 ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1989 out_sid, false);
1990}
1991
1992static inline int convert_context_handle_invalid_context(
1993 struct selinux_state *state,
1994 struct policydb *policydb,
1995 struct context *context)
1996{
1997 char *s;
1998 u32 len;
1999
2000 if (enforcing_enabled(state))
2001 return -EINVAL;
2002
2003 if (!context_struct_to_string(policydb, context, &s, &len)) {
2004 pr_warn("SELinux: Context %s would be invalid if enforcing\n",
2005 s);
2006 kfree(s);
2007 }
2008 return 0;
2009}
2010
2011/**
2012 * services_convert_context - Convert a security context across policies.
2013 * @args: populated convert_context_args struct
2014 * @oldc: original context
2015 * @newc: converted context
2016 * @gfp_flags: allocation flags
2017 *
2018 * Convert the values in the security context structure @oldc from the values
2019 * specified in the policy @args->oldp to the values specified in the policy
2020 * @args->newp, storing the new context in @newc, and verifying that the
2021 * context is valid under the new policy.
2022 */
2023int services_convert_context(struct convert_context_args *args,
2024 struct context *oldc, struct context *newc,
2025 gfp_t gfp_flags)
2026{
2027 struct ocontext *oc;
2028 struct role_datum *role;
2029 struct type_datum *typdatum;
2030 struct user_datum *usrdatum;
2031 char *s;
2032 u32 len;
2033 int rc;
2034
2035 if (oldc->str) {
2036 s = kstrdup(oldc->str, gfp_flags);
2037 if (!s)
2038 return -ENOMEM;
2039
2040 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL);
2041 if (rc == -EINVAL) {
2042 /*
2043 * Retain string representation for later mapping.
2044 *
2045 * IMPORTANT: We need to copy the contents of oldc->str
2046 * back into s again because string_to_context_struct()
2047 * may have garbled it.
2048 */
2049 memcpy(s, oldc->str, oldc->len);
2050 context_init(newc);
2051 newc->str = s;
2052 newc->len = oldc->len;
2053 return 0;
2054 }
2055 kfree(s);
2056 if (rc) {
2057 /* Other error condition, e.g. ENOMEM. */
2058 pr_err("SELinux: Unable to map context %s, rc = %d.\n",
2059 oldc->str, -rc);
2060 return rc;
2061 }
2062 pr_info("SELinux: Context %s became valid (mapped).\n",
2063 oldc->str);
2064 return 0;
2065 }
2066
2067 context_init(newc);
2068
2069 /* Convert the user. */
2070 usrdatum = symtab_search(&args->newp->p_users,
2071 sym_name(args->oldp, SYM_USERS, oldc->user - 1));
2072 if (!usrdatum)
2073 goto bad;
2074 newc->user = usrdatum->value;
2075
2076 /* Convert the role. */
2077 role = symtab_search(&args->newp->p_roles,
2078 sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2079 if (!role)
2080 goto bad;
2081 newc->role = role->value;
2082
2083 /* Convert the type. */
2084 typdatum = symtab_search(&args->newp->p_types,
2085 sym_name(args->oldp, SYM_TYPES, oldc->type - 1));
2086 if (!typdatum)
2087 goto bad;
2088 newc->type = typdatum->value;
2089
2090 /* Convert the MLS fields if dealing with MLS policies */
2091 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2092 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2093 if (rc)
2094 goto bad;
2095 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2096 /*
2097 * Switching between non-MLS and MLS policy:
2098 * ensure that the MLS fields of the context for all
2099 * existing entries in the sidtab are filled in with a
2100 * suitable default value, likely taken from one of the
2101 * initial SIDs.
2102 */
2103 oc = args->newp->ocontexts[OCON_ISID];
2104 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2105 oc = oc->next;
2106 if (!oc) {
2107 pr_err("SELinux: unable to look up"
2108 " the initial SIDs list\n");
2109 goto bad;
2110 }
2111 rc = mls_range_set(newc, &oc->context[0].range);
2112 if (rc)
2113 goto bad;
2114 }
2115
2116 /* Check the validity of the new context. */
2117 if (!policydb_context_isvalid(args->newp, newc)) {
2118 rc = convert_context_handle_invalid_context(args->state,
2119 args->oldp, oldc);
2120 if (rc)
2121 goto bad;
2122 }
2123
2124 return 0;
2125bad:
2126 /* Map old representation to string and save it. */
2127 rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2128 if (rc)
2129 return rc;
2130 context_destroy(newc);
2131 newc->str = s;
2132 newc->len = len;
2133 pr_info("SELinux: Context %s became invalid (unmapped).\n",
2134 newc->str);
2135 return 0;
2136}
2137
2138static void security_load_policycaps(struct selinux_state *state,
2139 struct selinux_policy *policy)
2140{
2141 struct policydb *p;
2142 unsigned int i;
2143 struct ebitmap_node *node;
2144
2145 p = &policy->policydb;
2146
2147 for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2148 WRITE_ONCE(state->policycap[i],
2149 ebitmap_get_bit(&p->policycaps, i));
2150
2151 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2152 pr_info("SELinux: policy capability %s=%d\n",
2153 selinux_policycap_names[i],
2154 ebitmap_get_bit(&p->policycaps, i));
2155
2156 ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2157 if (i >= ARRAY_SIZE(selinux_policycap_names))
2158 pr_info("SELinux: unknown policy capability %u\n",
2159 i);
2160 }
2161}
2162
2163static int security_preserve_bools(struct selinux_policy *oldpolicy,
2164 struct selinux_policy *newpolicy);
2165
2166static void selinux_policy_free(struct selinux_policy *policy)
2167{
2168 if (!policy)
2169 return;
2170
2171 sidtab_destroy(policy->sidtab);
2172 kfree(policy->map.mapping);
2173 policydb_destroy(&policy->policydb);
2174 kfree(policy->sidtab);
2175 kfree(policy);
2176}
2177
2178static void selinux_policy_cond_free(struct selinux_policy *policy)
2179{
2180 cond_policydb_destroy_dup(&policy->policydb);
2181 kfree(policy);
2182}
2183
2184void selinux_policy_cancel(struct selinux_state *state,
2185 struct selinux_load_state *load_state)
2186{
2187 struct selinux_policy *oldpolicy;
2188
2189 oldpolicy = rcu_dereference_protected(state->policy,
2190 lockdep_is_held(&state->policy_mutex));
2191
2192 sidtab_cancel_convert(oldpolicy->sidtab);
2193 selinux_policy_free(load_state->policy);
2194 kfree(load_state->convert_data);
2195}
2196
2197static void selinux_notify_policy_change(struct selinux_state *state,
2198 u32 seqno)
2199{
2200 /* Flush external caches and notify userspace of policy load */
2201 avc_ss_reset(state->avc, seqno);
2202 selnl_notify_policyload(seqno);
2203 selinux_status_update_policyload(state, seqno);
2204 selinux_netlbl_cache_invalidate();
2205 selinux_xfrm_notify_policyload();
2206 selinux_ima_measure_state_locked(state);
2207}
2208
2209void selinux_policy_commit(struct selinux_state *state,
2210 struct selinux_load_state *load_state)
2211{
2212 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
2213 unsigned long flags;
2214 u32 seqno;
2215
2216 oldpolicy = rcu_dereference_protected(state->policy,
2217 lockdep_is_held(&state->policy_mutex));
2218
2219 /* If switching between different policy types, log MLS status */
2220 if (oldpolicy) {
2221 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
2222 pr_info("SELinux: Disabling MLS support...\n");
2223 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
2224 pr_info("SELinux: Enabling MLS support...\n");
2225 }
2226
2227 /* Set latest granting seqno for new policy. */
2228 if (oldpolicy)
2229 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
2230 else
2231 newpolicy->latest_granting = 1;
2232 seqno = newpolicy->latest_granting;
2233
2234 /* Install the new policy. */
2235 if (oldpolicy) {
2236 sidtab_freeze_begin(oldpolicy->sidtab, &flags);
2237 rcu_assign_pointer(state->policy, newpolicy);
2238 sidtab_freeze_end(oldpolicy->sidtab, &flags);
2239 } else {
2240 rcu_assign_pointer(state->policy, newpolicy);
2241 }
2242
2243 /* Load the policycaps from the new policy */
2244 security_load_policycaps(state, newpolicy);
2245
2246 if (!selinux_initialized(state)) {
2247 /*
2248 * After first policy load, the security server is
2249 * marked as initialized and ready to handle requests and
2250 * any objects created prior to policy load are then labeled.
2251 */
2252 selinux_mark_initialized(state);
2253 selinux_complete_init();
2254 }
2255
2256 /* Free the old policy */
2257 synchronize_rcu();
2258 selinux_policy_free(oldpolicy);
2259 kfree(load_state->convert_data);
2260
2261 /* Notify others of the policy change */
2262 selinux_notify_policy_change(state, seqno);
2263}
2264
2265/**
2266 * security_load_policy - Load a security policy configuration.
2267 * @state: SELinux state
2268 * @data: binary policy data
2269 * @len: length of data in bytes
2270 * @load_state: policy load state
2271 *
2272 * Load a new set of security policy configuration data,
2273 * validate it and convert the SID table as necessary.
2274 * This function will flush the access vector cache after
2275 * loading the new policy.
2276 */
2277int security_load_policy(struct selinux_state *state, void *data, size_t len,
2278 struct selinux_load_state *load_state)
2279{
2280 struct selinux_policy *newpolicy, *oldpolicy;
2281 struct selinux_policy_convert_data *convert_data;
2282 int rc = 0;
2283 struct policy_file file = { data, len }, *fp = &file;
2284
2285 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2286 if (!newpolicy)
2287 return -ENOMEM;
2288
2289 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2290 if (!newpolicy->sidtab) {
2291 rc = -ENOMEM;
2292 goto err_policy;
2293 }
2294
2295 rc = policydb_read(&newpolicy->policydb, fp);
2296 if (rc)
2297 goto err_sidtab;
2298
2299 newpolicy->policydb.len = len;
2300 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2301 &newpolicy->map);
2302 if (rc)
2303 goto err_policydb;
2304
2305 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2306 if (rc) {
2307 pr_err("SELinux: unable to load the initial SIDs\n");
2308 goto err_mapping;
2309 }
2310
2311 if (!selinux_initialized(state)) {
2312 /* First policy load, so no need to preserve state from old policy */
2313 load_state->policy = newpolicy;
2314 load_state->convert_data = NULL;
2315 return 0;
2316 }
2317
2318 oldpolicy = rcu_dereference_protected(state->policy,
2319 lockdep_is_held(&state->policy_mutex));
2320
2321 /* Preserve active boolean values from the old policy */
2322 rc = security_preserve_bools(oldpolicy, newpolicy);
2323 if (rc) {
2324 pr_err("SELinux: unable to preserve booleans\n");
2325 goto err_free_isids;
2326 }
2327
2328 /*
2329 * Convert the internal representations of contexts
2330 * in the new SID table.
2331 */
2332
2333 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2334 if (!convert_data) {
2335 rc = -ENOMEM;
2336 goto err_free_isids;
2337 }
2338
2339 convert_data->args.state = state;
2340 convert_data->args.oldp = &oldpolicy->policydb;
2341 convert_data->args.newp = &newpolicy->policydb;
2342
2343 convert_data->sidtab_params.args = &convert_data->args;
2344 convert_data->sidtab_params.target = newpolicy->sidtab;
2345
2346 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2347 if (rc) {
2348 pr_err("SELinux: unable to convert the internal"
2349 " representation of contexts in the new SID"
2350 " table\n");
2351 goto err_free_convert_data;
2352 }
2353
2354 load_state->policy = newpolicy;
2355 load_state->convert_data = convert_data;
2356 return 0;
2357
2358err_free_convert_data:
2359 kfree(convert_data);
2360err_free_isids:
2361 sidtab_destroy(newpolicy->sidtab);
2362err_mapping:
2363 kfree(newpolicy->map.mapping);
2364err_policydb:
2365 policydb_destroy(&newpolicy->policydb);
2366err_sidtab:
2367 kfree(newpolicy->sidtab);
2368err_policy:
2369 kfree(newpolicy);
2370
2371 return rc;
2372}
2373
2374/**
2375 * ocontext_to_sid - Helper to safely get sid for an ocontext
2376 * @sidtab: SID table
2377 * @c: ocontext structure
2378 * @index: index of the context entry (0 or 1)
2379 * @out_sid: pointer to the resulting SID value
2380 *
2381 * For all ocontexts except OCON_ISID the SID fields are populated
2382 * on-demand when needed. Since updating the SID value is an SMP-sensitive
2383 * operation, this helper must be used to do that safely.
2384 *
2385 * WARNING: This function may return -ESTALE, indicating that the caller
2386 * must retry the operation after re-acquiring the policy pointer!
2387 */
2388static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
2389 size_t index, u32 *out_sid)
2390{
2391 int rc;
2392 u32 sid;
2393
2394 /* Ensure the associated sidtab entry is visible to this thread. */
2395 sid = smp_load_acquire(&c->sid[index]);
2396 if (!sid) {
2397 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
2398 if (rc)
2399 return rc;
2400
2401 /*
2402 * Ensure the new sidtab entry is visible to other threads
2403 * when they see the SID.
2404 */
2405 smp_store_release(&c->sid[index], sid);
2406 }
2407 *out_sid = sid;
2408 return 0;
2409}
2410
2411/**
2412 * security_port_sid - Obtain the SID for a port.
2413 * @state: SELinux state
2414 * @protocol: protocol number
2415 * @port: port number
2416 * @out_sid: security identifier
2417 */
2418int security_port_sid(struct selinux_state *state,
2419 u8 protocol, u16 port, u32 *out_sid)
2420{
2421 struct selinux_policy *policy;
2422 struct policydb *policydb;
2423 struct sidtab *sidtab;
2424 struct ocontext *c;
2425 int rc;
2426
2427 if (!selinux_initialized(state)) {
2428 *out_sid = SECINITSID_PORT;
2429 return 0;
2430 }
2431
2432retry:
2433 rc = 0;
2434 rcu_read_lock();
2435 policy = rcu_dereference(state->policy);
2436 policydb = &policy->policydb;
2437 sidtab = policy->sidtab;
2438
2439 c = policydb->ocontexts[OCON_PORT];
2440 while (c) {
2441 if (c->u.port.protocol == protocol &&
2442 c->u.port.low_port <= port &&
2443 c->u.port.high_port >= port)
2444 break;
2445 c = c->next;
2446 }
2447
2448 if (c) {
2449 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2450 if (rc == -ESTALE) {
2451 rcu_read_unlock();
2452 goto retry;
2453 }
2454 if (rc)
2455 goto out;
2456 } else {
2457 *out_sid = SECINITSID_PORT;
2458 }
2459
2460out:
2461 rcu_read_unlock();
2462 return rc;
2463}
2464
2465/**
2466 * security_ib_pkey_sid - Obtain the SID for a pkey.
2467 * @state: SELinux state
2468 * @subnet_prefix: Subnet Prefix
2469 * @pkey_num: pkey number
2470 * @out_sid: security identifier
2471 */
2472int security_ib_pkey_sid(struct selinux_state *state,
2473 u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2474{
2475 struct selinux_policy *policy;
2476 struct policydb *policydb;
2477 struct sidtab *sidtab;
2478 struct ocontext *c;
2479 int rc;
2480
2481 if (!selinux_initialized(state)) {
2482 *out_sid = SECINITSID_UNLABELED;
2483 return 0;
2484 }
2485
2486retry:
2487 rc = 0;
2488 rcu_read_lock();
2489 policy = rcu_dereference(state->policy);
2490 policydb = &policy->policydb;
2491 sidtab = policy->sidtab;
2492
2493 c = policydb->ocontexts[OCON_IBPKEY];
2494 while (c) {
2495 if (c->u.ibpkey.low_pkey <= pkey_num &&
2496 c->u.ibpkey.high_pkey >= pkey_num &&
2497 c->u.ibpkey.subnet_prefix == subnet_prefix)
2498 break;
2499
2500 c = c->next;
2501 }
2502
2503 if (c) {
2504 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2505 if (rc == -ESTALE) {
2506 rcu_read_unlock();
2507 goto retry;
2508 }
2509 if (rc)
2510 goto out;
2511 } else
2512 *out_sid = SECINITSID_UNLABELED;
2513
2514out:
2515 rcu_read_unlock();
2516 return rc;
2517}
2518
2519/**
2520 * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2521 * @state: SELinux state
2522 * @dev_name: device name
2523 * @port_num: port number
2524 * @out_sid: security identifier
2525 */
2526int security_ib_endport_sid(struct selinux_state *state,
2527 const char *dev_name, u8 port_num, u32 *out_sid)
2528{
2529 struct selinux_policy *policy;
2530 struct policydb *policydb;
2531 struct sidtab *sidtab;
2532 struct ocontext *c;
2533 int rc;
2534
2535 if (!selinux_initialized(state)) {
2536 *out_sid = SECINITSID_UNLABELED;
2537 return 0;
2538 }
2539
2540retry:
2541 rc = 0;
2542 rcu_read_lock();
2543 policy = rcu_dereference(state->policy);
2544 policydb = &policy->policydb;
2545 sidtab = policy->sidtab;
2546
2547 c = policydb->ocontexts[OCON_IBENDPORT];
2548 while (c) {
2549 if (c->u.ibendport.port == port_num &&
2550 !strncmp(c->u.ibendport.dev_name,
2551 dev_name,
2552 IB_DEVICE_NAME_MAX))
2553 break;
2554
2555 c = c->next;
2556 }
2557
2558 if (c) {
2559 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2560 if (rc == -ESTALE) {
2561 rcu_read_unlock();
2562 goto retry;
2563 }
2564 if (rc)
2565 goto out;
2566 } else
2567 *out_sid = SECINITSID_UNLABELED;
2568
2569out:
2570 rcu_read_unlock();
2571 return rc;
2572}
2573
2574/**
2575 * security_netif_sid - Obtain the SID for a network interface.
2576 * @state: SELinux state
2577 * @name: interface name
2578 * @if_sid: interface SID
2579 */
2580int security_netif_sid(struct selinux_state *state,
2581 char *name, u32 *if_sid)
2582{
2583 struct selinux_policy *policy;
2584 struct policydb *policydb;
2585 struct sidtab *sidtab;
2586 int rc;
2587 struct ocontext *c;
2588
2589 if (!selinux_initialized(state)) {
2590 *if_sid = SECINITSID_NETIF;
2591 return 0;
2592 }
2593
2594retry:
2595 rc = 0;
2596 rcu_read_lock();
2597 policy = rcu_dereference(state->policy);
2598 policydb = &policy->policydb;
2599 sidtab = policy->sidtab;
2600
2601 c = policydb->ocontexts[OCON_NETIF];
2602 while (c) {
2603 if (strcmp(name, c->u.name) == 0)
2604 break;
2605 c = c->next;
2606 }
2607
2608 if (c) {
2609 rc = ocontext_to_sid(sidtab, c, 0, if_sid);
2610 if (rc == -ESTALE) {
2611 rcu_read_unlock();
2612 goto retry;
2613 }
2614 if (rc)
2615 goto out;
2616 } else
2617 *if_sid = SECINITSID_NETIF;
2618
2619out:
2620 rcu_read_unlock();
2621 return rc;
2622}
2623
2624static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2625{
2626 int i, fail = 0;
2627
2628 for (i = 0; i < 4; i++)
2629 if (addr[i] != (input[i] & mask[i])) {
2630 fail = 1;
2631 break;
2632 }
2633
2634 return !fail;
2635}
2636
2637/**
2638 * security_node_sid - Obtain the SID for a node (host).
2639 * @state: SELinux state
2640 * @domain: communication domain aka address family
2641 * @addrp: address
2642 * @addrlen: address length in bytes
2643 * @out_sid: security identifier
2644 */
2645int security_node_sid(struct selinux_state *state,
2646 u16 domain,
2647 void *addrp,
2648 u32 addrlen,
2649 u32 *out_sid)
2650{
2651 struct selinux_policy *policy;
2652 struct policydb *policydb;
2653 struct sidtab *sidtab;
2654 int rc;
2655 struct ocontext *c;
2656
2657 if (!selinux_initialized(state)) {
2658 *out_sid = SECINITSID_NODE;
2659 return 0;
2660 }
2661
2662retry:
2663 rcu_read_lock();
2664 policy = rcu_dereference(state->policy);
2665 policydb = &policy->policydb;
2666 sidtab = policy->sidtab;
2667
2668 switch (domain) {
2669 case AF_INET: {
2670 u32 addr;
2671
2672 rc = -EINVAL;
2673 if (addrlen != sizeof(u32))
2674 goto out;
2675
2676 addr = *((u32 *)addrp);
2677
2678 c = policydb->ocontexts[OCON_NODE];
2679 while (c) {
2680 if (c->u.node.addr == (addr & c->u.node.mask))
2681 break;
2682 c = c->next;
2683 }
2684 break;
2685 }
2686
2687 case AF_INET6:
2688 rc = -EINVAL;
2689 if (addrlen != sizeof(u64) * 2)
2690 goto out;
2691 c = policydb->ocontexts[OCON_NODE6];
2692 while (c) {
2693 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2694 c->u.node6.mask))
2695 break;
2696 c = c->next;
2697 }
2698 break;
2699
2700 default:
2701 rc = 0;
2702 *out_sid = SECINITSID_NODE;
2703 goto out;
2704 }
2705
2706 if (c) {
2707 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2708 if (rc == -ESTALE) {
2709 rcu_read_unlock();
2710 goto retry;
2711 }
2712 if (rc)
2713 goto out;
2714 } else {
2715 *out_sid = SECINITSID_NODE;
2716 }
2717
2718 rc = 0;
2719out:
2720 rcu_read_unlock();
2721 return rc;
2722}
2723
2724#define SIDS_NEL 25
2725
2726/**
2727 * security_get_user_sids - Obtain reachable SIDs for a user.
2728 * @state: SELinux state
2729 * @fromsid: starting SID
2730 * @username: username
2731 * @sids: array of reachable SIDs for user
2732 * @nel: number of elements in @sids
2733 *
2734 * Generate the set of SIDs for legal security contexts
2735 * for a given user that can be reached by @fromsid.
2736 * Set *@sids to point to a dynamically allocated
2737 * array containing the set of SIDs. Set *@nel to the
2738 * number of elements in the array.
2739 */
2740
2741int security_get_user_sids(struct selinux_state *state,
2742 u32 fromsid,
2743 char *username,
2744 u32 **sids,
2745 u32 *nel)
2746{
2747 struct selinux_policy *policy;
2748 struct policydb *policydb;
2749 struct sidtab *sidtab;
2750 struct context *fromcon, usercon;
2751 u32 *mysids = NULL, *mysids2, sid;
2752 u32 i, j, mynel, maxnel = SIDS_NEL;
2753 struct user_datum *user;
2754 struct role_datum *role;
2755 struct ebitmap_node *rnode, *tnode;
2756 int rc;
2757
2758 *sids = NULL;
2759 *nel = 0;
2760
2761 if (!selinux_initialized(state))
2762 return 0;
2763
2764 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2765 if (!mysids)
2766 return -ENOMEM;
2767
2768retry:
2769 mynel = 0;
2770 rcu_read_lock();
2771 policy = rcu_dereference(state->policy);
2772 policydb = &policy->policydb;
2773 sidtab = policy->sidtab;
2774
2775 context_init(&usercon);
2776
2777 rc = -EINVAL;
2778 fromcon = sidtab_search(sidtab, fromsid);
2779 if (!fromcon)
2780 goto out_unlock;
2781
2782 rc = -EINVAL;
2783 user = symtab_search(&policydb->p_users, username);
2784 if (!user)
2785 goto out_unlock;
2786
2787 usercon.user = user->value;
2788
2789 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2790 role = policydb->role_val_to_struct[i];
2791 usercon.role = i + 1;
2792 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2793 usercon.type = j + 1;
2794
2795 if (mls_setup_user_range(policydb, fromcon, user,
2796 &usercon))
2797 continue;
2798
2799 rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2800 if (rc == -ESTALE) {
2801 rcu_read_unlock();
2802 goto retry;
2803 }
2804 if (rc)
2805 goto out_unlock;
2806 if (mynel < maxnel) {
2807 mysids[mynel++] = sid;
2808 } else {
2809 rc = -ENOMEM;
2810 maxnel += SIDS_NEL;
2811 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2812 if (!mysids2)
2813 goto out_unlock;
2814 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2815 kfree(mysids);
2816 mysids = mysids2;
2817 mysids[mynel++] = sid;
2818 }
2819 }
2820 }
2821 rc = 0;
2822out_unlock:
2823 rcu_read_unlock();
2824 if (rc || !mynel) {
2825 kfree(mysids);
2826 return rc;
2827 }
2828
2829 rc = -ENOMEM;
2830 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2831 if (!mysids2) {
2832 kfree(mysids);
2833 return rc;
2834 }
2835 for (i = 0, j = 0; i < mynel; i++) {
2836 struct av_decision dummy_avd;
2837 rc = avc_has_perm_noaudit(state,
2838 fromsid, mysids[i],
2839 SECCLASS_PROCESS, /* kernel value */
2840 PROCESS__TRANSITION, AVC_STRICT,
2841 &dummy_avd);
2842 if (!rc)
2843 mysids2[j++] = mysids[i];
2844 cond_resched();
2845 }
2846 kfree(mysids);
2847 *sids = mysids2;
2848 *nel = j;
2849 return 0;
2850}
2851
2852/**
2853 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2854 * @policy: policy
2855 * @fstype: filesystem type
2856 * @path: path from root of mount
2857 * @orig_sclass: file security class
2858 * @sid: SID for path
2859 *
2860 * Obtain a SID to use for a file in a filesystem that
2861 * cannot support xattr or use a fixed labeling behavior like
2862 * transition SIDs or task SIDs.
2863 *
2864 * WARNING: This function may return -ESTALE, indicating that the caller
2865 * must retry the operation after re-acquiring the policy pointer!
2866 */
2867static inline int __security_genfs_sid(struct selinux_policy *policy,
2868 const char *fstype,
2869 const char *path,
2870 u16 orig_sclass,
2871 u32 *sid)
2872{
2873 struct policydb *policydb = &policy->policydb;
2874 struct sidtab *sidtab = policy->sidtab;
2875 int len;
2876 u16 sclass;
2877 struct genfs *genfs;
2878 struct ocontext *c;
2879 int cmp = 0;
2880
2881 while (path[0] == '/' && path[1] == '/')
2882 path++;
2883
2884 sclass = unmap_class(&policy->map, orig_sclass);
2885 *sid = SECINITSID_UNLABELED;
2886
2887 for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2888 cmp = strcmp(fstype, genfs->fstype);
2889 if (cmp <= 0)
2890 break;
2891 }
2892
2893 if (!genfs || cmp)
2894 return -ENOENT;
2895
2896 for (c = genfs->head; c; c = c->next) {
2897 len = strlen(c->u.name);
2898 if ((!c->v.sclass || sclass == c->v.sclass) &&
2899 (strncmp(c->u.name, path, len) == 0))
2900 break;
2901 }
2902
2903 if (!c)
2904 return -ENOENT;
2905
2906 return ocontext_to_sid(sidtab, c, 0, sid);
2907}
2908
2909/**
2910 * security_genfs_sid - Obtain a SID for a file in a filesystem
2911 * @state: SELinux state
2912 * @fstype: filesystem type
2913 * @path: path from root of mount
2914 * @orig_sclass: file security class
2915 * @sid: SID for path
2916 *
2917 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2918 * it afterward.
2919 */
2920int security_genfs_sid(struct selinux_state *state,
2921 const char *fstype,
2922 const char *path,
2923 u16 orig_sclass,
2924 u32 *sid)
2925{
2926 struct selinux_policy *policy;
2927 int retval;
2928
2929 if (!selinux_initialized(state)) {
2930 *sid = SECINITSID_UNLABELED;
2931 return 0;
2932 }
2933
2934 do {
2935 rcu_read_lock();
2936 policy = rcu_dereference(state->policy);
2937 retval = __security_genfs_sid(policy, fstype, path,
2938 orig_sclass, sid);
2939 rcu_read_unlock();
2940 } while (retval == -ESTALE);
2941 return retval;
2942}
2943
2944int selinux_policy_genfs_sid(struct selinux_policy *policy,
2945 const char *fstype,
2946 const char *path,
2947 u16 orig_sclass,
2948 u32 *sid)
2949{
2950 /* no lock required, policy is not yet accessible by other threads */
2951 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2952}
2953
2954/**
2955 * security_fs_use - Determine how to handle labeling for a filesystem.
2956 * @state: SELinux state
2957 * @sb: superblock in question
2958 */
2959int security_fs_use(struct selinux_state *state, struct super_block *sb)
2960{
2961 struct selinux_policy *policy;
2962 struct policydb *policydb;
2963 struct sidtab *sidtab;
2964 int rc;
2965 struct ocontext *c;
2966 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2967 const char *fstype = sb->s_type->name;
2968
2969 if (!selinux_initialized(state)) {
2970 sbsec->behavior = SECURITY_FS_USE_NONE;
2971 sbsec->sid = SECINITSID_UNLABELED;
2972 return 0;
2973 }
2974
2975retry:
2976 rcu_read_lock();
2977 policy = rcu_dereference(state->policy);
2978 policydb = &policy->policydb;
2979 sidtab = policy->sidtab;
2980
2981 c = policydb->ocontexts[OCON_FSUSE];
2982 while (c) {
2983 if (strcmp(fstype, c->u.name) == 0)
2984 break;
2985 c = c->next;
2986 }
2987
2988 if (c) {
2989 sbsec->behavior = c->v.behavior;
2990 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
2991 if (rc == -ESTALE) {
2992 rcu_read_unlock();
2993 goto retry;
2994 }
2995 if (rc)
2996 goto out;
2997 } else {
2998 rc = __security_genfs_sid(policy, fstype, "/",
2999 SECCLASS_DIR, &sbsec->sid);
3000 if (rc == -ESTALE) {
3001 rcu_read_unlock();
3002 goto retry;
3003 }
3004 if (rc) {
3005 sbsec->behavior = SECURITY_FS_USE_NONE;
3006 rc = 0;
3007 } else {
3008 sbsec->behavior = SECURITY_FS_USE_GENFS;
3009 }
3010 }
3011
3012out:
3013 rcu_read_unlock();
3014 return rc;
3015}
3016
3017int security_get_bools(struct selinux_policy *policy,
3018 u32 *len, char ***names, int **values)
3019{
3020 struct policydb *policydb;
3021 u32 i;
3022 int rc;
3023
3024 policydb = &policy->policydb;
3025
3026 *names = NULL;
3027 *values = NULL;
3028
3029 rc = 0;
3030 *len = policydb->p_bools.nprim;
3031 if (!*len)
3032 goto out;
3033
3034 rc = -ENOMEM;
3035 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
3036 if (!*names)
3037 goto err;
3038
3039 rc = -ENOMEM;
3040 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
3041 if (!*values)
3042 goto err;
3043
3044 for (i = 0; i < *len; i++) {
3045 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3046
3047 rc = -ENOMEM;
3048 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3049 GFP_ATOMIC);
3050 if (!(*names)[i])
3051 goto err;
3052 }
3053 rc = 0;
3054out:
3055 return rc;
3056err:
3057 if (*names) {
3058 for (i = 0; i < *len; i++)
3059 kfree((*names)[i]);
3060 kfree(*names);
3061 }
3062 kfree(*values);
3063 *len = 0;
3064 *names = NULL;
3065 *values = NULL;
3066 goto out;
3067}
3068
3069
3070int security_set_bools(struct selinux_state *state, u32 len, int *values)
3071{
3072 struct selinux_policy *newpolicy, *oldpolicy;
3073 int rc;
3074 u32 i, seqno = 0;
3075
3076 if (!selinux_initialized(state))
3077 return -EINVAL;
3078
3079 oldpolicy = rcu_dereference_protected(state->policy,
3080 lockdep_is_held(&state->policy_mutex));
3081
3082 /* Consistency check on number of booleans, should never fail */
3083 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3084 return -EINVAL;
3085
3086 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3087 if (!newpolicy)
3088 return -ENOMEM;
3089
3090 /*
3091 * Deep copy only the parts of the policydb that might be
3092 * modified as a result of changing booleans.
3093 */
3094 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3095 if (rc) {
3096 kfree(newpolicy);
3097 return -ENOMEM;
3098 }
3099
3100 /* Update the boolean states in the copy */
3101 for (i = 0; i < len; i++) {
3102 int new_state = !!values[i];
3103 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3104
3105 if (new_state != old_state) {
3106 audit_log(audit_context(), GFP_ATOMIC,
3107 AUDIT_MAC_CONFIG_CHANGE,
3108 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3109 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3110 new_state,
3111 old_state,
3112 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3113 audit_get_sessionid(current));
3114 newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3115 }
3116 }
3117
3118 /* Re-evaluate the conditional rules in the copy */
3119 evaluate_cond_nodes(&newpolicy->policydb);
3120
3121 /* Set latest granting seqno for new policy */
3122 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3123 seqno = newpolicy->latest_granting;
3124
3125 /* Install the new policy */
3126 rcu_assign_pointer(state->policy, newpolicy);
3127
3128 /*
3129 * Free the conditional portions of the old policydb
3130 * that were copied for the new policy, and the oldpolicy
3131 * structure itself but not what it references.
3132 */
3133 synchronize_rcu();
3134 selinux_policy_cond_free(oldpolicy);
3135
3136 /* Notify others of the policy change */
3137 selinux_notify_policy_change(state, seqno);
3138 return 0;
3139}
3140
3141int security_get_bool_value(struct selinux_state *state,
3142 u32 index)
3143{
3144 struct selinux_policy *policy;
3145 struct policydb *policydb;
3146 int rc;
3147 u32 len;
3148
3149 if (!selinux_initialized(state))
3150 return 0;
3151
3152 rcu_read_lock();
3153 policy = rcu_dereference(state->policy);
3154 policydb = &policy->policydb;
3155
3156 rc = -EFAULT;
3157 len = policydb->p_bools.nprim;
3158 if (index >= len)
3159 goto out;
3160
3161 rc = policydb->bool_val_to_struct[index]->state;
3162out:
3163 rcu_read_unlock();
3164 return rc;
3165}
3166
3167static int security_preserve_bools(struct selinux_policy *oldpolicy,
3168 struct selinux_policy *newpolicy)
3169{
3170 int rc, *bvalues = NULL;
3171 char **bnames = NULL;
3172 struct cond_bool_datum *booldatum;
3173 u32 i, nbools = 0;
3174
3175 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3176 if (rc)
3177 goto out;
3178 for (i = 0; i < nbools; i++) {
3179 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3180 bnames[i]);
3181 if (booldatum)
3182 booldatum->state = bvalues[i];
3183 }
3184 evaluate_cond_nodes(&newpolicy->policydb);
3185
3186out:
3187 if (bnames) {
3188 for (i = 0; i < nbools; i++)
3189 kfree(bnames[i]);
3190 }
3191 kfree(bnames);
3192 kfree(bvalues);
3193 return rc;
3194}
3195
3196/*
3197 * security_sid_mls_copy() - computes a new sid based on the given
3198 * sid and the mls portion of mls_sid.
3199 */
3200int security_sid_mls_copy(struct selinux_state *state,
3201 u32 sid, u32 mls_sid, u32 *new_sid)
3202{
3203 struct selinux_policy *policy;
3204 struct policydb *policydb;
3205 struct sidtab *sidtab;
3206 struct context *context1;
3207 struct context *context2;
3208 struct context newcon;
3209 char *s;
3210 u32 len;
3211 int rc;
3212
3213 if (!selinux_initialized(state)) {
3214 *new_sid = sid;
3215 return 0;
3216 }
3217
3218retry:
3219 rc = 0;
3220 context_init(&newcon);
3221
3222 rcu_read_lock();
3223 policy = rcu_dereference(state->policy);
3224 policydb = &policy->policydb;
3225 sidtab = policy->sidtab;
3226
3227 if (!policydb->mls_enabled) {
3228 *new_sid = sid;
3229 goto out_unlock;
3230 }
3231
3232 rc = -EINVAL;
3233 context1 = sidtab_search(sidtab, sid);
3234 if (!context1) {
3235 pr_err("SELinux: %s: unrecognized SID %d\n",
3236 __func__, sid);
3237 goto out_unlock;
3238 }
3239
3240 rc = -EINVAL;
3241 context2 = sidtab_search(sidtab, mls_sid);
3242 if (!context2) {
3243 pr_err("SELinux: %s: unrecognized SID %d\n",
3244 __func__, mls_sid);
3245 goto out_unlock;
3246 }
3247
3248 newcon.user = context1->user;
3249 newcon.role = context1->role;
3250 newcon.type = context1->type;
3251 rc = mls_context_cpy(&newcon, context2);
3252 if (rc)
3253 goto out_unlock;
3254
3255 /* Check the validity of the new context. */
3256 if (!policydb_context_isvalid(policydb, &newcon)) {
3257 rc = convert_context_handle_invalid_context(state, policydb,
3258 &newcon);
3259 if (rc) {
3260 if (!context_struct_to_string(policydb, &newcon, &s,
3261 &len)) {
3262 struct audit_buffer *ab;
3263
3264 ab = audit_log_start(audit_context(),
3265 GFP_ATOMIC,
3266 AUDIT_SELINUX_ERR);
3267 audit_log_format(ab,
3268 "op=security_sid_mls_copy invalid_context=");
3269 /* don't record NUL with untrusted strings */
3270 audit_log_n_untrustedstring(ab, s, len - 1);
3271 audit_log_end(ab);
3272 kfree(s);
3273 }
3274 goto out_unlock;
3275 }
3276 }
3277 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3278 if (rc == -ESTALE) {
3279 rcu_read_unlock();
3280 context_destroy(&newcon);
3281 goto retry;
3282 }
3283out_unlock:
3284 rcu_read_unlock();
3285 context_destroy(&newcon);
3286 return rc;
3287}
3288
3289/**
3290 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3291 * @state: SELinux state
3292 * @nlbl_sid: NetLabel SID
3293 * @nlbl_type: NetLabel labeling protocol type
3294 * @xfrm_sid: XFRM SID
3295 * @peer_sid: network peer sid
3296 *
3297 * Description:
3298 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3299 * resolved into a single SID it is returned via @peer_sid and the function
3300 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
3301 * returns a negative value. A table summarizing the behavior is below:
3302 *
3303 * | function return | @sid
3304 * ------------------------------+-----------------+-----------------
3305 * no peer labels | 0 | SECSID_NULL
3306 * single peer label | 0 | <peer_label>
3307 * multiple, consistent labels | 0 | <peer_label>
3308 * multiple, inconsistent labels | -<errno> | SECSID_NULL
3309 *
3310 */
3311int security_net_peersid_resolve(struct selinux_state *state,
3312 u32 nlbl_sid, u32 nlbl_type,
3313 u32 xfrm_sid,
3314 u32 *peer_sid)
3315{
3316 struct selinux_policy *policy;
3317 struct policydb *policydb;
3318 struct sidtab *sidtab;
3319 int rc;
3320 struct context *nlbl_ctx;
3321 struct context *xfrm_ctx;
3322
3323 *peer_sid = SECSID_NULL;
3324
3325 /* handle the common (which also happens to be the set of easy) cases
3326 * right away, these two if statements catch everything involving a
3327 * single or absent peer SID/label */
3328 if (xfrm_sid == SECSID_NULL) {
3329 *peer_sid = nlbl_sid;
3330 return 0;
3331 }
3332 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3333 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3334 * is present */
3335 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3336 *peer_sid = xfrm_sid;
3337 return 0;
3338 }
3339
3340 if (!selinux_initialized(state))
3341 return 0;
3342
3343 rcu_read_lock();
3344 policy = rcu_dereference(state->policy);
3345 policydb = &policy->policydb;
3346 sidtab = policy->sidtab;
3347
3348 /*
3349 * We don't need to check initialized here since the only way both
3350 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3351 * security server was initialized and state->initialized was true.
3352 */
3353 if (!policydb->mls_enabled) {
3354 rc = 0;
3355 goto out;
3356 }
3357
3358 rc = -EINVAL;
3359 nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3360 if (!nlbl_ctx) {
3361 pr_err("SELinux: %s: unrecognized SID %d\n",
3362 __func__, nlbl_sid);
3363 goto out;
3364 }
3365 rc = -EINVAL;
3366 xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3367 if (!xfrm_ctx) {
3368 pr_err("SELinux: %s: unrecognized SID %d\n",
3369 __func__, xfrm_sid);
3370 goto out;
3371 }
3372 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3373 if (rc)
3374 goto out;
3375
3376 /* at present NetLabel SIDs/labels really only carry MLS
3377 * information so if the MLS portion of the NetLabel SID
3378 * matches the MLS portion of the labeled XFRM SID/label
3379 * then pass along the XFRM SID as it is the most
3380 * expressive */
3381 *peer_sid = xfrm_sid;
3382out:
3383 rcu_read_unlock();
3384 return rc;
3385}
3386
3387static int get_classes_callback(void *k, void *d, void *args)
3388{
3389 struct class_datum *datum = d;
3390 char *name = k, **classes = args;
3391 int value = datum->value - 1;
3392
3393 classes[value] = kstrdup(name, GFP_ATOMIC);
3394 if (!classes[value])
3395 return -ENOMEM;
3396
3397 return 0;
3398}
3399
3400int security_get_classes(struct selinux_policy *policy,
3401 char ***classes, int *nclasses)
3402{
3403 struct policydb *policydb;
3404 int rc;
3405
3406 policydb = &policy->policydb;
3407
3408 rc = -ENOMEM;
3409 *nclasses = policydb->p_classes.nprim;
3410 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3411 if (!*classes)
3412 goto out;
3413
3414 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3415 *classes);
3416 if (rc) {
3417 int i;
3418 for (i = 0; i < *nclasses; i++)
3419 kfree((*classes)[i]);
3420 kfree(*classes);
3421 }
3422
3423out:
3424 return rc;
3425}
3426
3427static int get_permissions_callback(void *k, void *d, void *args)
3428{
3429 struct perm_datum *datum = d;
3430 char *name = k, **perms = args;
3431 int value = datum->value - 1;
3432
3433 perms[value] = kstrdup(name, GFP_ATOMIC);
3434 if (!perms[value])
3435 return -ENOMEM;
3436
3437 return 0;
3438}
3439
3440int security_get_permissions(struct selinux_policy *policy,
3441 char *class, char ***perms, int *nperms)
3442{
3443 struct policydb *policydb;
3444 int rc, i;
3445 struct class_datum *match;
3446
3447 policydb = &policy->policydb;
3448
3449 rc = -EINVAL;
3450 match = symtab_search(&policydb->p_classes, class);
3451 if (!match) {
3452 pr_err("SELinux: %s: unrecognized class %s\n",
3453 __func__, class);
3454 goto out;
3455 }
3456
3457 rc = -ENOMEM;
3458 *nperms = match->permissions.nprim;
3459 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3460 if (!*perms)
3461 goto out;
3462
3463 if (match->comdatum) {
3464 rc = hashtab_map(&match->comdatum->permissions.table,
3465 get_permissions_callback, *perms);
3466 if (rc)
3467 goto err;
3468 }
3469
3470 rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3471 *perms);
3472 if (rc)
3473 goto err;
3474
3475out:
3476 return rc;
3477
3478err:
3479 for (i = 0; i < *nperms; i++)
3480 kfree((*perms)[i]);
3481 kfree(*perms);
3482 return rc;
3483}
3484
3485int security_get_reject_unknown(struct selinux_state *state)
3486{
3487 struct selinux_policy *policy;
3488 int value;
3489
3490 if (!selinux_initialized(state))
3491 return 0;
3492
3493 rcu_read_lock();
3494 policy = rcu_dereference(state->policy);
3495 value = policy->policydb.reject_unknown;
3496 rcu_read_unlock();
3497 return value;
3498}
3499
3500int security_get_allow_unknown(struct selinux_state *state)
3501{
3502 struct selinux_policy *policy;
3503 int value;
3504
3505 if (!selinux_initialized(state))
3506 return 0;
3507
3508 rcu_read_lock();
3509 policy = rcu_dereference(state->policy);
3510 value = policy->policydb.allow_unknown;
3511 rcu_read_unlock();
3512 return value;
3513}
3514
3515/**
3516 * security_policycap_supported - Check for a specific policy capability
3517 * @state: SELinux state
3518 * @req_cap: capability
3519 *
3520 * Description:
3521 * This function queries the currently loaded policy to see if it supports the
3522 * capability specified by @req_cap. Returns true (1) if the capability is
3523 * supported, false (0) if it isn't supported.
3524 *
3525 */
3526int security_policycap_supported(struct selinux_state *state,
3527 unsigned int req_cap)
3528{
3529 struct selinux_policy *policy;
3530 int rc;
3531
3532 if (!selinux_initialized(state))
3533 return 0;
3534
3535 rcu_read_lock();
3536 policy = rcu_dereference(state->policy);
3537 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3538 rcu_read_unlock();
3539
3540 return rc;
3541}
3542
3543struct selinux_audit_rule {
3544 u32 au_seqno;
3545 struct context au_ctxt;
3546};
3547
3548void selinux_audit_rule_free(void *vrule)
3549{
3550 struct selinux_audit_rule *rule = vrule;
3551
3552 if (rule) {
3553 context_destroy(&rule->au_ctxt);
3554 kfree(rule);
3555 }
3556}
3557
3558int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3559{
3560 struct selinux_state *state = &selinux_state;
3561 struct selinux_policy *policy;
3562 struct policydb *policydb;
3563 struct selinux_audit_rule *tmprule;
3564 struct role_datum *roledatum;
3565 struct type_datum *typedatum;
3566 struct user_datum *userdatum;
3567 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3568 int rc = 0;
3569
3570 *rule = NULL;
3571
3572 if (!selinux_initialized(state))
3573 return -EOPNOTSUPP;
3574
3575 switch (field) {
3576 case AUDIT_SUBJ_USER:
3577 case AUDIT_SUBJ_ROLE:
3578 case AUDIT_SUBJ_TYPE:
3579 case AUDIT_OBJ_USER:
3580 case AUDIT_OBJ_ROLE:
3581 case AUDIT_OBJ_TYPE:
3582 /* only 'equals' and 'not equals' fit user, role, and type */
3583 if (op != Audit_equal && op != Audit_not_equal)
3584 return -EINVAL;
3585 break;
3586 case AUDIT_SUBJ_SEN:
3587 case AUDIT_SUBJ_CLR:
3588 case AUDIT_OBJ_LEV_LOW:
3589 case AUDIT_OBJ_LEV_HIGH:
3590 /* we do not allow a range, indicated by the presence of '-' */
3591 if (strchr(rulestr, '-'))
3592 return -EINVAL;
3593 break;
3594 default:
3595 /* only the above fields are valid */
3596 return -EINVAL;
3597 }
3598
3599 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3600 if (!tmprule)
3601 return -ENOMEM;
3602
3603 context_init(&tmprule->au_ctxt);
3604
3605 rcu_read_lock();
3606 policy = rcu_dereference(state->policy);
3607 policydb = &policy->policydb;
3608
3609 tmprule->au_seqno = policy->latest_granting;
3610
3611 switch (field) {
3612 case AUDIT_SUBJ_USER:
3613 case AUDIT_OBJ_USER:
3614 rc = -EINVAL;
3615 userdatum = symtab_search(&policydb->p_users, rulestr);
3616 if (!userdatum)
3617 goto out;
3618 tmprule->au_ctxt.user = userdatum->value;
3619 break;
3620 case AUDIT_SUBJ_ROLE:
3621 case AUDIT_OBJ_ROLE:
3622 rc = -EINVAL;
3623 roledatum = symtab_search(&policydb->p_roles, rulestr);
3624 if (!roledatum)
3625 goto out;
3626 tmprule->au_ctxt.role = roledatum->value;
3627 break;
3628 case AUDIT_SUBJ_TYPE:
3629 case AUDIT_OBJ_TYPE:
3630 rc = -EINVAL;
3631 typedatum = symtab_search(&policydb->p_types, rulestr);
3632 if (!typedatum)
3633 goto out;
3634 tmprule->au_ctxt.type = typedatum->value;
3635 break;
3636 case AUDIT_SUBJ_SEN:
3637 case AUDIT_SUBJ_CLR:
3638 case AUDIT_OBJ_LEV_LOW:
3639 case AUDIT_OBJ_LEV_HIGH:
3640 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3641 GFP_ATOMIC);
3642 if (rc)
3643 goto out;
3644 break;
3645 }
3646 rc = 0;
3647out:
3648 rcu_read_unlock();
3649
3650 if (rc) {
3651 selinux_audit_rule_free(tmprule);
3652 tmprule = NULL;
3653 }
3654
3655 *rule = tmprule;
3656
3657 return rc;
3658}
3659
3660/* Check to see if the rule contains any selinux fields */
3661int selinux_audit_rule_known(struct audit_krule *rule)
3662{
3663 int i;
3664
3665 for (i = 0; i < rule->field_count; i++) {
3666 struct audit_field *f = &rule->fields[i];
3667 switch (f->type) {
3668 case AUDIT_SUBJ_USER:
3669 case AUDIT_SUBJ_ROLE:
3670 case AUDIT_SUBJ_TYPE:
3671 case AUDIT_SUBJ_SEN:
3672 case AUDIT_SUBJ_CLR:
3673 case AUDIT_OBJ_USER:
3674 case AUDIT_OBJ_ROLE:
3675 case AUDIT_OBJ_TYPE:
3676 case AUDIT_OBJ_LEV_LOW:
3677 case AUDIT_OBJ_LEV_HIGH:
3678 return 1;
3679 }
3680 }
3681
3682 return 0;
3683}
3684
3685int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3686{
3687 struct selinux_state *state = &selinux_state;
3688 struct selinux_policy *policy;
3689 struct context *ctxt;
3690 struct mls_level *level;
3691 struct selinux_audit_rule *rule = vrule;
3692 int match = 0;
3693
3694 if (unlikely(!rule)) {
3695 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3696 return -ENOENT;
3697 }
3698
3699 if (!selinux_initialized(state))
3700 return 0;
3701
3702 rcu_read_lock();
3703
3704 policy = rcu_dereference(state->policy);
3705
3706 if (rule->au_seqno < policy->latest_granting) {
3707 match = -ESTALE;
3708 goto out;
3709 }
3710
3711 ctxt = sidtab_search(policy->sidtab, sid);
3712 if (unlikely(!ctxt)) {
3713 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3714 sid);
3715 match = -ENOENT;
3716 goto out;
3717 }
3718
3719 /* a field/op pair that is not caught here will simply fall through
3720 without a match */
3721 switch (field) {
3722 case AUDIT_SUBJ_USER:
3723 case AUDIT_OBJ_USER:
3724 switch (op) {
3725 case Audit_equal:
3726 match = (ctxt->user == rule->au_ctxt.user);
3727 break;
3728 case Audit_not_equal:
3729 match = (ctxt->user != rule->au_ctxt.user);
3730 break;
3731 }
3732 break;
3733 case AUDIT_SUBJ_ROLE:
3734 case AUDIT_OBJ_ROLE:
3735 switch (op) {
3736 case Audit_equal:
3737 match = (ctxt->role == rule->au_ctxt.role);
3738 break;
3739 case Audit_not_equal:
3740 match = (ctxt->role != rule->au_ctxt.role);
3741 break;
3742 }
3743 break;
3744 case AUDIT_SUBJ_TYPE:
3745 case AUDIT_OBJ_TYPE:
3746 switch (op) {
3747 case Audit_equal:
3748 match = (ctxt->type == rule->au_ctxt.type);
3749 break;
3750 case Audit_not_equal:
3751 match = (ctxt->type != rule->au_ctxt.type);
3752 break;
3753 }
3754 break;
3755 case AUDIT_SUBJ_SEN:
3756 case AUDIT_SUBJ_CLR:
3757 case AUDIT_OBJ_LEV_LOW:
3758 case AUDIT_OBJ_LEV_HIGH:
3759 level = ((field == AUDIT_SUBJ_SEN ||
3760 field == AUDIT_OBJ_LEV_LOW) ?
3761 &ctxt->range.level[0] : &ctxt->range.level[1]);
3762 switch (op) {
3763 case Audit_equal:
3764 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3765 level);
3766 break;
3767 case Audit_not_equal:
3768 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3769 level);
3770 break;
3771 case Audit_lt:
3772 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3773 level) &&
3774 !mls_level_eq(&rule->au_ctxt.range.level[0],
3775 level));
3776 break;
3777 case Audit_le:
3778 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3779 level);
3780 break;
3781 case Audit_gt:
3782 match = (mls_level_dom(level,
3783 &rule->au_ctxt.range.level[0]) &&
3784 !mls_level_eq(level,
3785 &rule->au_ctxt.range.level[0]));
3786 break;
3787 case Audit_ge:
3788 match = mls_level_dom(level,
3789 &rule->au_ctxt.range.level[0]);
3790 break;
3791 }
3792 }
3793
3794out:
3795 rcu_read_unlock();
3796 return match;
3797}
3798
3799static int aurule_avc_callback(u32 event)
3800{
3801 if (event == AVC_CALLBACK_RESET)
3802 return audit_update_lsm_rules();
3803 return 0;
3804}
3805
3806static int __init aurule_init(void)
3807{
3808 int err;
3809
3810 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3811 if (err)
3812 panic("avc_add_callback() failed, error %d\n", err);
3813
3814 return err;
3815}
3816__initcall(aurule_init);
3817
3818#ifdef CONFIG_NETLABEL
3819/**
3820 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3821 * @secattr: the NetLabel packet security attributes
3822 * @sid: the SELinux SID
3823 *
3824 * Description:
3825 * Attempt to cache the context in @ctx, which was derived from the packet in
3826 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3827 * already been initialized.
3828 *
3829 */
3830static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3831 u32 sid)
3832{
3833 u32 *sid_cache;
3834
3835 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3836 if (sid_cache == NULL)
3837 return;
3838 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3839 if (secattr->cache == NULL) {
3840 kfree(sid_cache);
3841 return;
3842 }
3843
3844 *sid_cache = sid;
3845 secattr->cache->free = kfree;
3846 secattr->cache->data = sid_cache;
3847 secattr->flags |= NETLBL_SECATTR_CACHE;
3848}
3849
3850/**
3851 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3852 * @state: SELinux state
3853 * @secattr: the NetLabel packet security attributes
3854 * @sid: the SELinux SID
3855 *
3856 * Description:
3857 * Convert the given NetLabel security attributes in @secattr into a
3858 * SELinux SID. If the @secattr field does not contain a full SELinux
3859 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3860 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3861 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3862 * conversion for future lookups. Returns zero on success, negative values on
3863 * failure.
3864 *
3865 */
3866int security_netlbl_secattr_to_sid(struct selinux_state *state,
3867 struct netlbl_lsm_secattr *secattr,
3868 u32 *sid)
3869{
3870 struct selinux_policy *policy;
3871 struct policydb *policydb;
3872 struct sidtab *sidtab;
3873 int rc;
3874 struct context *ctx;
3875 struct context ctx_new;
3876
3877 if (!selinux_initialized(state)) {
3878 *sid = SECSID_NULL;
3879 return 0;
3880 }
3881
3882retry:
3883 rc = 0;
3884 rcu_read_lock();
3885 policy = rcu_dereference(state->policy);
3886 policydb = &policy->policydb;
3887 sidtab = policy->sidtab;
3888
3889 if (secattr->flags & NETLBL_SECATTR_CACHE)
3890 *sid = *(u32 *)secattr->cache->data;
3891 else if (secattr->flags & NETLBL_SECATTR_SECID)
3892 *sid = secattr->attr.secid;
3893 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3894 rc = -EIDRM;
3895 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3896 if (ctx == NULL)
3897 goto out;
3898
3899 context_init(&ctx_new);
3900 ctx_new.user = ctx->user;
3901 ctx_new.role = ctx->role;
3902 ctx_new.type = ctx->type;
3903 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3904 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3905 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3906 if (rc)
3907 goto out;
3908 }
3909 rc = -EIDRM;
3910 if (!mls_context_isvalid(policydb, &ctx_new)) {
3911 ebitmap_destroy(&ctx_new.range.level[0].cat);
3912 goto out;
3913 }
3914
3915 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3916 ebitmap_destroy(&ctx_new.range.level[0].cat);
3917 if (rc == -ESTALE) {
3918 rcu_read_unlock();
3919 goto retry;
3920 }
3921 if (rc)
3922 goto out;
3923
3924 security_netlbl_cache_add(secattr, *sid);
3925 } else
3926 *sid = SECSID_NULL;
3927
3928out:
3929 rcu_read_unlock();
3930 return rc;
3931}
3932
3933/**
3934 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3935 * @state: SELinux state
3936 * @sid: the SELinux SID
3937 * @secattr: the NetLabel packet security attributes
3938 *
3939 * Description:
3940 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3941 * Returns zero on success, negative values on failure.
3942 *
3943 */
3944int security_netlbl_sid_to_secattr(struct selinux_state *state,
3945 u32 sid, struct netlbl_lsm_secattr *secattr)
3946{
3947 struct selinux_policy *policy;
3948 struct policydb *policydb;
3949 int rc;
3950 struct context *ctx;
3951
3952 if (!selinux_initialized(state))
3953 return 0;
3954
3955 rcu_read_lock();
3956 policy = rcu_dereference(state->policy);
3957 policydb = &policy->policydb;
3958
3959 rc = -ENOENT;
3960 ctx = sidtab_search(policy->sidtab, sid);
3961 if (ctx == NULL)
3962 goto out;
3963
3964 rc = -ENOMEM;
3965 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3966 GFP_ATOMIC);
3967 if (secattr->domain == NULL)
3968 goto out;
3969
3970 secattr->attr.secid = sid;
3971 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3972 mls_export_netlbl_lvl(policydb, ctx, secattr);
3973 rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3974out:
3975 rcu_read_unlock();
3976 return rc;
3977}
3978#endif /* CONFIG_NETLABEL */
3979
3980/**
3981 * __security_read_policy - read the policy.
3982 * @policy: SELinux policy
3983 * @data: binary policy data
3984 * @len: length of data in bytes
3985 *
3986 */
3987static int __security_read_policy(struct selinux_policy *policy,
3988 void *data, size_t *len)
3989{
3990 int rc;
3991 struct policy_file fp;
3992
3993 fp.data = data;
3994 fp.len = *len;
3995
3996 rc = policydb_write(&policy->policydb, &fp);
3997 if (rc)
3998 return rc;
3999
4000 *len = (unsigned long)fp.data - (unsigned long)data;
4001 return 0;
4002}
4003
4004/**
4005 * security_read_policy - read the policy.
4006 * @state: selinux_state
4007 * @data: binary policy data
4008 * @len: length of data in bytes
4009 *
4010 */
4011int security_read_policy(struct selinux_state *state,
4012 void **data, size_t *len)
4013{
4014 struct selinux_policy *policy;
4015
4016 policy = rcu_dereference_protected(
4017 state->policy, lockdep_is_held(&state->policy_mutex));
4018 if (!policy)
4019 return -EINVAL;
4020
4021 *len = policy->policydb.len;
4022 *data = vmalloc_user(*len);
4023 if (!*data)
4024 return -ENOMEM;
4025
4026 return __security_read_policy(policy, *data, len);
4027}
4028
4029/**
4030 * security_read_state_kernel - read the policy.
4031 * @state: selinux_state
4032 * @data: binary policy data
4033 * @len: length of data in bytes
4034 *
4035 * Allocates kernel memory for reading SELinux policy.
4036 * This function is for internal use only and should not
4037 * be used for returning data to user space.
4038 *
4039 * This function must be called with policy_mutex held.
4040 */
4041int security_read_state_kernel(struct selinux_state *state,
4042 void **data, size_t *len)
4043{
4044 int err;
4045 struct selinux_policy *policy;
4046
4047 policy = rcu_dereference_protected(
4048 state->policy, lockdep_is_held(&state->policy_mutex));
4049 if (!policy)
4050 return -EINVAL;
4051
4052 *len = policy->policydb.len;
4053 *data = vmalloc(*len);
4054 if (!*data)
4055 return -ENOMEM;
4056
4057 err = __security_read_policy(policy, *data, len);
4058 if (err) {
4059 vfree(*data);
4060 *data = NULL;
4061 *len = 0;
4062 }
4063 return err;
4064}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Implementation of the security services.
4 *
5 * Authors : Stephen Smalley, <stephen.smalley.work@gmail.com>
6 * James Morris <jmorris@redhat.com>
7 *
8 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
9 *
10 * Support for enhanced MLS infrastructure.
11 * Support for context based audit filters.
12 *
13 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
14 *
15 * Added conditional policy language extensions
16 *
17 * Updated: Hewlett-Packard <paul@paul-moore.com>
18 *
19 * Added support for NetLabel
20 * Added support for the policy capability bitmap
21 *
22 * Updated: Chad Sellers <csellers@tresys.com>
23 *
24 * Added validation of kernel classes and permissions
25 *
26 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
27 *
28 * Added support for bounds domain and audit messaged on masked permissions
29 *
30 * Updated: Guido Trentalancia <guido@trentalancia.com>
31 *
32 * Added support for runtime switching of the policy type
33 *
34 * Copyright (C) 2008, 2009 NEC Corporation
35 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
36 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
37 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
38 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
39 */
40#include <linux/kernel.h>
41#include <linux/slab.h>
42#include <linux/string.h>
43#include <linux/spinlock.h>
44#include <linux/rcupdate.h>
45#include <linux/errno.h>
46#include <linux/in.h>
47#include <linux/sched.h>
48#include <linux/audit.h>
49#include <linux/vmalloc.h>
50#include <linux/lsm_hooks.h>
51#include <net/netlabel.h>
52
53#include "flask.h"
54#include "avc.h"
55#include "avc_ss.h"
56#include "security.h"
57#include "context.h"
58#include "policydb.h"
59#include "sidtab.h"
60#include "services.h"
61#include "conditional.h"
62#include "mls.h"
63#include "objsec.h"
64#include "netlabel.h"
65#include "xfrm.h"
66#include "ebitmap.h"
67#include "audit.h"
68#include "policycap_names.h"
69#include "ima.h"
70
71struct selinux_policy_convert_data {
72 struct convert_context_args args;
73 struct sidtab_convert_params sidtab_params;
74};
75
76/* Forward declaration. */
77static int context_struct_to_string(struct policydb *policydb,
78 struct context *context,
79 char **scontext,
80 u32 *scontext_len);
81
82static int sidtab_entry_to_string(struct policydb *policydb,
83 struct sidtab *sidtab,
84 struct sidtab_entry *entry,
85 char **scontext,
86 u32 *scontext_len);
87
88static void context_struct_compute_av(struct policydb *policydb,
89 struct context *scontext,
90 struct context *tcontext,
91 u16 tclass,
92 struct av_decision *avd,
93 struct extended_perms *xperms);
94
95static int selinux_set_mapping(struct policydb *pol,
96 const struct security_class_mapping *map,
97 struct selinux_map *out_map)
98{
99 u16 i, j;
100 bool print_unknown_handle = false;
101
102 /* Find number of classes in the input mapping */
103 if (!map)
104 return -EINVAL;
105 i = 0;
106 while (map[i].name)
107 i++;
108
109 /* Allocate space for the class records, plus one for class zero */
110 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
111 if (!out_map->mapping)
112 return -ENOMEM;
113
114 /* Store the raw class and permission values */
115 j = 0;
116 while (map[j].name) {
117 const struct security_class_mapping *p_in = map + (j++);
118 struct selinux_mapping *p_out = out_map->mapping + j;
119 u16 k;
120
121 /* An empty class string skips ahead */
122 if (!strcmp(p_in->name, "")) {
123 p_out->num_perms = 0;
124 continue;
125 }
126
127 p_out->value = string_to_security_class(pol, p_in->name);
128 if (!p_out->value) {
129 pr_info("SELinux: Class %s not defined in policy.\n",
130 p_in->name);
131 if (pol->reject_unknown)
132 goto err;
133 p_out->num_perms = 0;
134 print_unknown_handle = true;
135 continue;
136 }
137
138 k = 0;
139 while (p_in->perms[k]) {
140 /* An empty permission string skips ahead */
141 if (!*p_in->perms[k]) {
142 k++;
143 continue;
144 }
145 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
146 p_in->perms[k]);
147 if (!p_out->perms[k]) {
148 pr_info("SELinux: Permission %s in class %s not defined in policy.\n",
149 p_in->perms[k], p_in->name);
150 if (pol->reject_unknown)
151 goto err;
152 print_unknown_handle = true;
153 }
154
155 k++;
156 }
157 p_out->num_perms = k;
158 }
159
160 if (print_unknown_handle)
161 pr_info("SELinux: the above unknown classes and permissions will be %s\n",
162 pol->allow_unknown ? "allowed" : "denied");
163
164 out_map->size = i;
165 return 0;
166err:
167 kfree(out_map->mapping);
168 out_map->mapping = NULL;
169 return -EINVAL;
170}
171
172/*
173 * Get real, policy values from mapped values
174 */
175
176static u16 unmap_class(struct selinux_map *map, u16 tclass)
177{
178 if (tclass < map->size)
179 return map->mapping[tclass].value;
180
181 return tclass;
182}
183
184/*
185 * Get kernel value for class from its policy value
186 */
187static u16 map_class(struct selinux_map *map, u16 pol_value)
188{
189 u16 i;
190
191 for (i = 1; i < map->size; i++) {
192 if (map->mapping[i].value == pol_value)
193 return i;
194 }
195
196 return SECCLASS_NULL;
197}
198
199static void map_decision(struct selinux_map *map,
200 u16 tclass, struct av_decision *avd,
201 int allow_unknown)
202{
203 if (tclass < map->size) {
204 struct selinux_mapping *mapping = &map->mapping[tclass];
205 unsigned int i, n = mapping->num_perms;
206 u32 result;
207
208 for (i = 0, result = 0; i < n; i++) {
209 if (avd->allowed & mapping->perms[i])
210 result |= (u32)1<<i;
211 if (allow_unknown && !mapping->perms[i])
212 result |= (u32)1<<i;
213 }
214 avd->allowed = result;
215
216 for (i = 0, result = 0; i < n; i++)
217 if (avd->auditallow & mapping->perms[i])
218 result |= (u32)1<<i;
219 avd->auditallow = result;
220
221 for (i = 0, result = 0; i < n; i++) {
222 if (avd->auditdeny & mapping->perms[i])
223 result |= (u32)1<<i;
224 if (!allow_unknown && !mapping->perms[i])
225 result |= (u32)1<<i;
226 }
227 /*
228 * In case the kernel has a bug and requests a permission
229 * between num_perms and the maximum permission number, we
230 * should audit that denial
231 */
232 for (; i < (sizeof(u32)*8); i++)
233 result |= (u32)1<<i;
234 avd->auditdeny = result;
235 }
236}
237
238int security_mls_enabled(void)
239{
240 int mls_enabled;
241 struct selinux_policy *policy;
242
243 if (!selinux_initialized())
244 return 0;
245
246 rcu_read_lock();
247 policy = rcu_dereference(selinux_state.policy);
248 mls_enabled = policy->policydb.mls_enabled;
249 rcu_read_unlock();
250 return mls_enabled;
251}
252
253/*
254 * Return the boolean value of a constraint expression
255 * when it is applied to the specified source and target
256 * security contexts.
257 *
258 * xcontext is a special beast... It is used by the validatetrans rules
259 * only. For these rules, scontext is the context before the transition,
260 * tcontext is the context after the transition, and xcontext is the context
261 * of the process performing the transition. All other callers of
262 * constraint_expr_eval should pass in NULL for xcontext.
263 */
264static int constraint_expr_eval(struct policydb *policydb,
265 struct context *scontext,
266 struct context *tcontext,
267 struct context *xcontext,
268 struct constraint_expr *cexpr)
269{
270 u32 val1, val2;
271 struct context *c;
272 struct role_datum *r1, *r2;
273 struct mls_level *l1, *l2;
274 struct constraint_expr *e;
275 int s[CEXPR_MAXDEPTH];
276 int sp = -1;
277
278 for (e = cexpr; e; e = e->next) {
279 switch (e->expr_type) {
280 case CEXPR_NOT:
281 BUG_ON(sp < 0);
282 s[sp] = !s[sp];
283 break;
284 case CEXPR_AND:
285 BUG_ON(sp < 1);
286 sp--;
287 s[sp] &= s[sp + 1];
288 break;
289 case CEXPR_OR:
290 BUG_ON(sp < 1);
291 sp--;
292 s[sp] |= s[sp + 1];
293 break;
294 case CEXPR_ATTR:
295 if (sp == (CEXPR_MAXDEPTH - 1))
296 return 0;
297 switch (e->attr) {
298 case CEXPR_USER:
299 val1 = scontext->user;
300 val2 = tcontext->user;
301 break;
302 case CEXPR_TYPE:
303 val1 = scontext->type;
304 val2 = tcontext->type;
305 break;
306 case CEXPR_ROLE:
307 val1 = scontext->role;
308 val2 = tcontext->role;
309 r1 = policydb->role_val_to_struct[val1 - 1];
310 r2 = policydb->role_val_to_struct[val2 - 1];
311 switch (e->op) {
312 case CEXPR_DOM:
313 s[++sp] = ebitmap_get_bit(&r1->dominates,
314 val2 - 1);
315 continue;
316 case CEXPR_DOMBY:
317 s[++sp] = ebitmap_get_bit(&r2->dominates,
318 val1 - 1);
319 continue;
320 case CEXPR_INCOMP:
321 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
322 val2 - 1) &&
323 !ebitmap_get_bit(&r2->dominates,
324 val1 - 1));
325 continue;
326 default:
327 break;
328 }
329 break;
330 case CEXPR_L1L2:
331 l1 = &(scontext->range.level[0]);
332 l2 = &(tcontext->range.level[0]);
333 goto mls_ops;
334 case CEXPR_L1H2:
335 l1 = &(scontext->range.level[0]);
336 l2 = &(tcontext->range.level[1]);
337 goto mls_ops;
338 case CEXPR_H1L2:
339 l1 = &(scontext->range.level[1]);
340 l2 = &(tcontext->range.level[0]);
341 goto mls_ops;
342 case CEXPR_H1H2:
343 l1 = &(scontext->range.level[1]);
344 l2 = &(tcontext->range.level[1]);
345 goto mls_ops;
346 case CEXPR_L1H1:
347 l1 = &(scontext->range.level[0]);
348 l2 = &(scontext->range.level[1]);
349 goto mls_ops;
350 case CEXPR_L2H2:
351 l1 = &(tcontext->range.level[0]);
352 l2 = &(tcontext->range.level[1]);
353 goto mls_ops;
354mls_ops:
355 switch (e->op) {
356 case CEXPR_EQ:
357 s[++sp] = mls_level_eq(l1, l2);
358 continue;
359 case CEXPR_NEQ:
360 s[++sp] = !mls_level_eq(l1, l2);
361 continue;
362 case CEXPR_DOM:
363 s[++sp] = mls_level_dom(l1, l2);
364 continue;
365 case CEXPR_DOMBY:
366 s[++sp] = mls_level_dom(l2, l1);
367 continue;
368 case CEXPR_INCOMP:
369 s[++sp] = mls_level_incomp(l2, l1);
370 continue;
371 default:
372 BUG();
373 return 0;
374 }
375 break;
376 default:
377 BUG();
378 return 0;
379 }
380
381 switch (e->op) {
382 case CEXPR_EQ:
383 s[++sp] = (val1 == val2);
384 break;
385 case CEXPR_NEQ:
386 s[++sp] = (val1 != val2);
387 break;
388 default:
389 BUG();
390 return 0;
391 }
392 break;
393 case CEXPR_NAMES:
394 if (sp == (CEXPR_MAXDEPTH-1))
395 return 0;
396 c = scontext;
397 if (e->attr & CEXPR_TARGET)
398 c = tcontext;
399 else if (e->attr & CEXPR_XTARGET) {
400 c = xcontext;
401 if (!c) {
402 BUG();
403 return 0;
404 }
405 }
406 if (e->attr & CEXPR_USER)
407 val1 = c->user;
408 else if (e->attr & CEXPR_ROLE)
409 val1 = c->role;
410 else if (e->attr & CEXPR_TYPE)
411 val1 = c->type;
412 else {
413 BUG();
414 return 0;
415 }
416
417 switch (e->op) {
418 case CEXPR_EQ:
419 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
420 break;
421 case CEXPR_NEQ:
422 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
423 break;
424 default:
425 BUG();
426 return 0;
427 }
428 break;
429 default:
430 BUG();
431 return 0;
432 }
433 }
434
435 BUG_ON(sp != 0);
436 return s[0];
437}
438
439/*
440 * security_dump_masked_av - dumps masked permissions during
441 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
442 */
443static int dump_masked_av_helper(void *k, void *d, void *args)
444{
445 struct perm_datum *pdatum = d;
446 char **permission_names = args;
447
448 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
449
450 permission_names[pdatum->value - 1] = (char *)k;
451
452 return 0;
453}
454
455static void security_dump_masked_av(struct policydb *policydb,
456 struct context *scontext,
457 struct context *tcontext,
458 u16 tclass,
459 u32 permissions,
460 const char *reason)
461{
462 struct common_datum *common_dat;
463 struct class_datum *tclass_dat;
464 struct audit_buffer *ab;
465 char *tclass_name;
466 char *scontext_name = NULL;
467 char *tcontext_name = NULL;
468 char *permission_names[32];
469 int index;
470 u32 length;
471 bool need_comma = false;
472
473 if (!permissions)
474 return;
475
476 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
477 tclass_dat = policydb->class_val_to_struct[tclass - 1];
478 common_dat = tclass_dat->comdatum;
479
480 /* init permission_names */
481 if (common_dat &&
482 hashtab_map(&common_dat->permissions.table,
483 dump_masked_av_helper, permission_names) < 0)
484 goto out;
485
486 if (hashtab_map(&tclass_dat->permissions.table,
487 dump_masked_av_helper, permission_names) < 0)
488 goto out;
489
490 /* get scontext/tcontext in text form */
491 if (context_struct_to_string(policydb, scontext,
492 &scontext_name, &length) < 0)
493 goto out;
494
495 if (context_struct_to_string(policydb, tcontext,
496 &tcontext_name, &length) < 0)
497 goto out;
498
499 /* audit a message */
500 ab = audit_log_start(audit_context(),
501 GFP_ATOMIC, AUDIT_SELINUX_ERR);
502 if (!ab)
503 goto out;
504
505 audit_log_format(ab, "op=security_compute_av reason=%s "
506 "scontext=%s tcontext=%s tclass=%s perms=",
507 reason, scontext_name, tcontext_name, tclass_name);
508
509 for (index = 0; index < 32; index++) {
510 u32 mask = (1 << index);
511
512 if ((mask & permissions) == 0)
513 continue;
514
515 audit_log_format(ab, "%s%s",
516 need_comma ? "," : "",
517 permission_names[index]
518 ? permission_names[index] : "????");
519 need_comma = true;
520 }
521 audit_log_end(ab);
522out:
523 /* release scontext/tcontext */
524 kfree(tcontext_name);
525 kfree(scontext_name);
526}
527
528/*
529 * security_boundary_permission - drops violated permissions
530 * on boundary constraint.
531 */
532static void type_attribute_bounds_av(struct policydb *policydb,
533 struct context *scontext,
534 struct context *tcontext,
535 u16 tclass,
536 struct av_decision *avd)
537{
538 struct context lo_scontext;
539 struct context lo_tcontext, *tcontextp = tcontext;
540 struct av_decision lo_avd;
541 struct type_datum *source;
542 struct type_datum *target;
543 u32 masked = 0;
544
545 source = policydb->type_val_to_struct[scontext->type - 1];
546 BUG_ON(!source);
547
548 if (!source->bounds)
549 return;
550
551 target = policydb->type_val_to_struct[tcontext->type - 1];
552 BUG_ON(!target);
553
554 memset(&lo_avd, 0, sizeof(lo_avd));
555
556 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
557 lo_scontext.type = source->bounds;
558
559 if (target->bounds) {
560 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
561 lo_tcontext.type = target->bounds;
562 tcontextp = &lo_tcontext;
563 }
564
565 context_struct_compute_av(policydb, &lo_scontext,
566 tcontextp,
567 tclass,
568 &lo_avd,
569 NULL);
570
571 masked = ~lo_avd.allowed & avd->allowed;
572
573 if (likely(!masked))
574 return; /* no masked permission */
575
576 /* mask violated permissions */
577 avd->allowed &= ~masked;
578
579 /* audit masked permissions */
580 security_dump_masked_av(policydb, scontext, tcontext,
581 tclass, masked, "bounds");
582}
583
584/*
585 * Flag which drivers have permissions and which base permissions are covered.
586 */
587void services_compute_xperms_drivers(
588 struct extended_perms *xperms,
589 struct avtab_node *node)
590{
591 unsigned int i;
592
593 switch (node->datum.u.xperms->specified) {
594 case AVTAB_XPERMS_IOCTLDRIVER:
595 xperms->base_perms |= AVC_EXT_IOCTL;
596 /* if one or more driver has all permissions allowed */
597 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
598 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
599 break;
600 case AVTAB_XPERMS_IOCTLFUNCTION:
601 xperms->base_perms |= AVC_EXT_IOCTL;
602 /* if allowing permissions within a driver */
603 security_xperm_set(xperms->drivers.p,
604 node->datum.u.xperms->driver);
605 break;
606 case AVTAB_XPERMS_NLMSG:
607 xperms->base_perms |= AVC_EXT_NLMSG;
608 /* if allowing permissions within a driver */
609 security_xperm_set(xperms->drivers.p,
610 node->datum.u.xperms->driver);
611 break;
612 }
613
614 xperms->len = 1;
615}
616
617/*
618 * Compute access vectors and extended permissions based on a context
619 * structure pair for the permissions in a particular class.
620 */
621static void context_struct_compute_av(struct policydb *policydb,
622 struct context *scontext,
623 struct context *tcontext,
624 u16 tclass,
625 struct av_decision *avd,
626 struct extended_perms *xperms)
627{
628 struct constraint_node *constraint;
629 struct role_allow *ra;
630 struct avtab_key avkey;
631 struct avtab_node *node;
632 struct class_datum *tclass_datum;
633 struct ebitmap *sattr, *tattr;
634 struct ebitmap_node *snode, *tnode;
635 unsigned int i, j;
636
637 avd->allowed = 0;
638 avd->auditallow = 0;
639 avd->auditdeny = 0xffffffff;
640 if (xperms) {
641 memset(xperms, 0, sizeof(*xperms));
642 }
643
644 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
645 pr_warn_ratelimited("SELinux: Invalid class %u\n", tclass);
646 return;
647 }
648
649 tclass_datum = policydb->class_val_to_struct[tclass - 1];
650
651 /*
652 * If a specific type enforcement rule was defined for
653 * this permission check, then use it.
654 */
655 avkey.target_class = tclass;
656 avkey.specified = AVTAB_AV | AVTAB_XPERMS;
657 sattr = &policydb->type_attr_map_array[scontext->type - 1];
658 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
659 ebitmap_for_each_positive_bit(sattr, snode, i) {
660 ebitmap_for_each_positive_bit(tattr, tnode, j) {
661 avkey.source_type = i + 1;
662 avkey.target_type = j + 1;
663 for (node = avtab_search_node(&policydb->te_avtab,
664 &avkey);
665 node;
666 node = avtab_search_node_next(node, avkey.specified)) {
667 if (node->key.specified == AVTAB_ALLOWED)
668 avd->allowed |= node->datum.u.data;
669 else if (node->key.specified == AVTAB_AUDITALLOW)
670 avd->auditallow |= node->datum.u.data;
671 else if (node->key.specified == AVTAB_AUDITDENY)
672 avd->auditdeny &= node->datum.u.data;
673 else if (xperms && (node->key.specified & AVTAB_XPERMS))
674 services_compute_xperms_drivers(xperms, node);
675 }
676
677 /* Check conditional av table for additional permissions */
678 cond_compute_av(&policydb->te_cond_avtab, &avkey,
679 avd, xperms);
680
681 }
682 }
683
684 /*
685 * Remove any permissions prohibited by a constraint (this includes
686 * the MLS policy).
687 */
688 constraint = tclass_datum->constraints;
689 while (constraint) {
690 if ((constraint->permissions & (avd->allowed)) &&
691 !constraint_expr_eval(policydb, scontext, tcontext, NULL,
692 constraint->expr)) {
693 avd->allowed &= ~(constraint->permissions);
694 }
695 constraint = constraint->next;
696 }
697
698 /*
699 * If checking process transition permission and the
700 * role is changing, then check the (current_role, new_role)
701 * pair.
702 */
703 if (tclass == policydb->process_class &&
704 (avd->allowed & policydb->process_trans_perms) &&
705 scontext->role != tcontext->role) {
706 for (ra = policydb->role_allow; ra; ra = ra->next) {
707 if (scontext->role == ra->role &&
708 tcontext->role == ra->new_role)
709 break;
710 }
711 if (!ra)
712 avd->allowed &= ~policydb->process_trans_perms;
713 }
714
715 /*
716 * If the given source and target types have boundary
717 * constraint, lazy checks have to mask any violated
718 * permission and notice it to userspace via audit.
719 */
720 type_attribute_bounds_av(policydb, scontext, tcontext,
721 tclass, avd);
722}
723
724static int security_validtrans_handle_fail(struct selinux_policy *policy,
725 struct sidtab_entry *oentry,
726 struct sidtab_entry *nentry,
727 struct sidtab_entry *tentry,
728 u16 tclass)
729{
730 struct policydb *p = &policy->policydb;
731 struct sidtab *sidtab = policy->sidtab;
732 char *o = NULL, *n = NULL, *t = NULL;
733 u32 olen, nlen, tlen;
734
735 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
736 goto out;
737 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
738 goto out;
739 if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
740 goto out;
741 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
742 "op=security_validate_transition seresult=denied"
743 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
744 o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
745out:
746 kfree(o);
747 kfree(n);
748 kfree(t);
749
750 if (!enforcing_enabled())
751 return 0;
752 return -EPERM;
753}
754
755static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
756 u16 orig_tclass, bool user)
757{
758 struct selinux_policy *policy;
759 struct policydb *policydb;
760 struct sidtab *sidtab;
761 struct sidtab_entry *oentry;
762 struct sidtab_entry *nentry;
763 struct sidtab_entry *tentry;
764 struct class_datum *tclass_datum;
765 struct constraint_node *constraint;
766 u16 tclass;
767 int rc = 0;
768
769
770 if (!selinux_initialized())
771 return 0;
772
773 rcu_read_lock();
774
775 policy = rcu_dereference(selinux_state.policy);
776 policydb = &policy->policydb;
777 sidtab = policy->sidtab;
778
779 if (!user)
780 tclass = unmap_class(&policy->map, orig_tclass);
781 else
782 tclass = orig_tclass;
783
784 if (!tclass || tclass > policydb->p_classes.nprim) {
785 rc = -EINVAL;
786 goto out;
787 }
788 tclass_datum = policydb->class_val_to_struct[tclass - 1];
789
790 oentry = sidtab_search_entry(sidtab, oldsid);
791 if (!oentry) {
792 pr_err("SELinux: %s: unrecognized SID %d\n",
793 __func__, oldsid);
794 rc = -EINVAL;
795 goto out;
796 }
797
798 nentry = sidtab_search_entry(sidtab, newsid);
799 if (!nentry) {
800 pr_err("SELinux: %s: unrecognized SID %d\n",
801 __func__, newsid);
802 rc = -EINVAL;
803 goto out;
804 }
805
806 tentry = sidtab_search_entry(sidtab, tasksid);
807 if (!tentry) {
808 pr_err("SELinux: %s: unrecognized SID %d\n",
809 __func__, tasksid);
810 rc = -EINVAL;
811 goto out;
812 }
813
814 constraint = tclass_datum->validatetrans;
815 while (constraint) {
816 if (!constraint_expr_eval(policydb, &oentry->context,
817 &nentry->context, &tentry->context,
818 constraint->expr)) {
819 if (user)
820 rc = -EPERM;
821 else
822 rc = security_validtrans_handle_fail(policy,
823 oentry,
824 nentry,
825 tentry,
826 tclass);
827 goto out;
828 }
829 constraint = constraint->next;
830 }
831
832out:
833 rcu_read_unlock();
834 return rc;
835}
836
837int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
838 u16 tclass)
839{
840 return security_compute_validatetrans(oldsid, newsid, tasksid,
841 tclass, true);
842}
843
844int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
845 u16 orig_tclass)
846{
847 return security_compute_validatetrans(oldsid, newsid, tasksid,
848 orig_tclass, false);
849}
850
851/*
852 * security_bounded_transition - check whether the given
853 * transition is directed to bounded, or not.
854 * It returns 0, if @newsid is bounded by @oldsid.
855 * Otherwise, it returns error code.
856 *
857 * @oldsid : current security identifier
858 * @newsid : destinated security identifier
859 */
860int security_bounded_transition(u32 old_sid, u32 new_sid)
861{
862 struct selinux_policy *policy;
863 struct policydb *policydb;
864 struct sidtab *sidtab;
865 struct sidtab_entry *old_entry, *new_entry;
866 struct type_datum *type;
867 u32 index;
868 int rc;
869
870 if (!selinux_initialized())
871 return 0;
872
873 rcu_read_lock();
874 policy = rcu_dereference(selinux_state.policy);
875 policydb = &policy->policydb;
876 sidtab = policy->sidtab;
877
878 rc = -EINVAL;
879 old_entry = sidtab_search_entry(sidtab, old_sid);
880 if (!old_entry) {
881 pr_err("SELinux: %s: unrecognized SID %u\n",
882 __func__, old_sid);
883 goto out;
884 }
885
886 rc = -EINVAL;
887 new_entry = sidtab_search_entry(sidtab, new_sid);
888 if (!new_entry) {
889 pr_err("SELinux: %s: unrecognized SID %u\n",
890 __func__, new_sid);
891 goto out;
892 }
893
894 rc = 0;
895 /* type/domain unchanged */
896 if (old_entry->context.type == new_entry->context.type)
897 goto out;
898
899 index = new_entry->context.type;
900 while (true) {
901 type = policydb->type_val_to_struct[index - 1];
902 BUG_ON(!type);
903
904 /* not bounded anymore */
905 rc = -EPERM;
906 if (!type->bounds)
907 break;
908
909 /* @newsid is bounded by @oldsid */
910 rc = 0;
911 if (type->bounds == old_entry->context.type)
912 break;
913
914 index = type->bounds;
915 }
916
917 if (rc) {
918 char *old_name = NULL;
919 char *new_name = NULL;
920 u32 length;
921
922 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
923 &old_name, &length) &&
924 !sidtab_entry_to_string(policydb, sidtab, new_entry,
925 &new_name, &length)) {
926 audit_log(audit_context(),
927 GFP_ATOMIC, AUDIT_SELINUX_ERR,
928 "op=security_bounded_transition "
929 "seresult=denied "
930 "oldcontext=%s newcontext=%s",
931 old_name, new_name);
932 }
933 kfree(new_name);
934 kfree(old_name);
935 }
936out:
937 rcu_read_unlock();
938
939 return rc;
940}
941
942static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
943{
944 avd->allowed = 0;
945 avd->auditallow = 0;
946 avd->auditdeny = 0xffffffff;
947 if (policy)
948 avd->seqno = policy->latest_granting;
949 else
950 avd->seqno = 0;
951 avd->flags = 0;
952}
953
954static void update_xperms_extended_data(u8 specified,
955 struct extended_perms_data *from,
956 struct extended_perms_data *xp_data)
957{
958 unsigned int i;
959
960 switch (specified) {
961 case AVTAB_XPERMS_IOCTLDRIVER:
962 memset(xp_data->p, 0xff, sizeof(xp_data->p));
963 break;
964 case AVTAB_XPERMS_IOCTLFUNCTION:
965 case AVTAB_XPERMS_NLMSG:
966 for (i = 0; i < ARRAY_SIZE(xp_data->p); i++)
967 xp_data->p[i] |= from->p[i];
968 break;
969 }
970
971}
972
973void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
974 struct avtab_node *node)
975{
976 switch (node->datum.u.xperms->specified) {
977 case AVTAB_XPERMS_IOCTLFUNCTION:
978 if (xpermd->base_perm != AVC_EXT_IOCTL ||
979 xpermd->driver != node->datum.u.xperms->driver)
980 return;
981 break;
982 case AVTAB_XPERMS_IOCTLDRIVER:
983 if (xpermd->base_perm != AVC_EXT_IOCTL ||
984 !security_xperm_test(node->datum.u.xperms->perms.p,
985 xpermd->driver))
986 return;
987 break;
988 case AVTAB_XPERMS_NLMSG:
989 if (xpermd->base_perm != AVC_EXT_NLMSG ||
990 xpermd->driver != node->datum.u.xperms->driver)
991 return;
992 break;
993 default:
994 pr_warn_once(
995 "SELinux: unknown extended permission (%u) will be ignored\n",
996 node->datum.u.xperms->specified);
997 return;
998 }
999
1000 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
1001 xpermd->used |= XPERMS_ALLOWED;
1002 update_xperms_extended_data(node->datum.u.xperms->specified,
1003 &node->datum.u.xperms->perms,
1004 xpermd->allowed);
1005 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
1006 xpermd->used |= XPERMS_AUDITALLOW;
1007 update_xperms_extended_data(node->datum.u.xperms->specified,
1008 &node->datum.u.xperms->perms,
1009 xpermd->auditallow);
1010 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
1011 xpermd->used |= XPERMS_DONTAUDIT;
1012 update_xperms_extended_data(node->datum.u.xperms->specified,
1013 &node->datum.u.xperms->perms,
1014 xpermd->dontaudit);
1015 } else {
1016 pr_warn_once("SELinux: unknown specified key (%u)\n",
1017 node->key.specified);
1018 }
1019}
1020
1021void security_compute_xperms_decision(u32 ssid,
1022 u32 tsid,
1023 u16 orig_tclass,
1024 u8 driver,
1025 u8 base_perm,
1026 struct extended_perms_decision *xpermd)
1027{
1028 struct selinux_policy *policy;
1029 struct policydb *policydb;
1030 struct sidtab *sidtab;
1031 u16 tclass;
1032 struct context *scontext, *tcontext;
1033 struct avtab_key avkey;
1034 struct avtab_node *node;
1035 struct ebitmap *sattr, *tattr;
1036 struct ebitmap_node *snode, *tnode;
1037 unsigned int i, j;
1038
1039 xpermd->base_perm = base_perm;
1040 xpermd->driver = driver;
1041 xpermd->used = 0;
1042 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1043 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1044 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1045
1046 rcu_read_lock();
1047 if (!selinux_initialized())
1048 goto allow;
1049
1050 policy = rcu_dereference(selinux_state.policy);
1051 policydb = &policy->policydb;
1052 sidtab = policy->sidtab;
1053
1054 scontext = sidtab_search(sidtab, ssid);
1055 if (!scontext) {
1056 pr_err("SELinux: %s: unrecognized SID %d\n",
1057 __func__, ssid);
1058 goto out;
1059 }
1060
1061 tcontext = sidtab_search(sidtab, tsid);
1062 if (!tcontext) {
1063 pr_err("SELinux: %s: unrecognized SID %d\n",
1064 __func__, tsid);
1065 goto out;
1066 }
1067
1068 tclass = unmap_class(&policy->map, orig_tclass);
1069 if (unlikely(orig_tclass && !tclass)) {
1070 if (policydb->allow_unknown)
1071 goto allow;
1072 goto out;
1073 }
1074
1075
1076 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1077 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1078 goto out;
1079 }
1080
1081 avkey.target_class = tclass;
1082 avkey.specified = AVTAB_XPERMS;
1083 sattr = &policydb->type_attr_map_array[scontext->type - 1];
1084 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1085 ebitmap_for_each_positive_bit(sattr, snode, i) {
1086 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1087 avkey.source_type = i + 1;
1088 avkey.target_type = j + 1;
1089 for (node = avtab_search_node(&policydb->te_avtab,
1090 &avkey);
1091 node;
1092 node = avtab_search_node_next(node, avkey.specified))
1093 services_compute_xperms_decision(xpermd, node);
1094
1095 cond_compute_xperms(&policydb->te_cond_avtab,
1096 &avkey, xpermd);
1097 }
1098 }
1099out:
1100 rcu_read_unlock();
1101 return;
1102allow:
1103 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1104 goto out;
1105}
1106
1107/**
1108 * security_compute_av - Compute access vector decisions.
1109 * @ssid: source security identifier
1110 * @tsid: target security identifier
1111 * @orig_tclass: target security class
1112 * @avd: access vector decisions
1113 * @xperms: extended permissions
1114 *
1115 * Compute a set of access vector decisions based on the
1116 * SID pair (@ssid, @tsid) for the permissions in @tclass.
1117 */
1118void security_compute_av(u32 ssid,
1119 u32 tsid,
1120 u16 orig_tclass,
1121 struct av_decision *avd,
1122 struct extended_perms *xperms)
1123{
1124 struct selinux_policy *policy;
1125 struct policydb *policydb;
1126 struct sidtab *sidtab;
1127 u16 tclass;
1128 struct context *scontext = NULL, *tcontext = NULL;
1129
1130 rcu_read_lock();
1131 policy = rcu_dereference(selinux_state.policy);
1132 avd_init(policy, avd);
1133 xperms->len = 0;
1134 if (!selinux_initialized())
1135 goto allow;
1136
1137 policydb = &policy->policydb;
1138 sidtab = policy->sidtab;
1139
1140 scontext = sidtab_search(sidtab, ssid);
1141 if (!scontext) {
1142 pr_err("SELinux: %s: unrecognized SID %d\n",
1143 __func__, ssid);
1144 goto out;
1145 }
1146
1147 /* permissive domain? */
1148 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1149 avd->flags |= AVD_FLAGS_PERMISSIVE;
1150
1151 tcontext = sidtab_search(sidtab, tsid);
1152 if (!tcontext) {
1153 pr_err("SELinux: %s: unrecognized SID %d\n",
1154 __func__, tsid);
1155 goto out;
1156 }
1157
1158 tclass = unmap_class(&policy->map, orig_tclass);
1159 if (unlikely(orig_tclass && !tclass)) {
1160 if (policydb->allow_unknown)
1161 goto allow;
1162 goto out;
1163 }
1164 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1165 xperms);
1166 map_decision(&policy->map, orig_tclass, avd,
1167 policydb->allow_unknown);
1168out:
1169 rcu_read_unlock();
1170 return;
1171allow:
1172 avd->allowed = 0xffffffff;
1173 goto out;
1174}
1175
1176void security_compute_av_user(u32 ssid,
1177 u32 tsid,
1178 u16 tclass,
1179 struct av_decision *avd)
1180{
1181 struct selinux_policy *policy;
1182 struct policydb *policydb;
1183 struct sidtab *sidtab;
1184 struct context *scontext = NULL, *tcontext = NULL;
1185
1186 rcu_read_lock();
1187 policy = rcu_dereference(selinux_state.policy);
1188 avd_init(policy, avd);
1189 if (!selinux_initialized())
1190 goto allow;
1191
1192 policydb = &policy->policydb;
1193 sidtab = policy->sidtab;
1194
1195 scontext = sidtab_search(sidtab, ssid);
1196 if (!scontext) {
1197 pr_err("SELinux: %s: unrecognized SID %d\n",
1198 __func__, ssid);
1199 goto out;
1200 }
1201
1202 /* permissive domain? */
1203 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1204 avd->flags |= AVD_FLAGS_PERMISSIVE;
1205
1206 tcontext = sidtab_search(sidtab, tsid);
1207 if (!tcontext) {
1208 pr_err("SELinux: %s: unrecognized SID %d\n",
1209 __func__, tsid);
1210 goto out;
1211 }
1212
1213 if (unlikely(!tclass)) {
1214 if (policydb->allow_unknown)
1215 goto allow;
1216 goto out;
1217 }
1218
1219 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1220 NULL);
1221 out:
1222 rcu_read_unlock();
1223 return;
1224allow:
1225 avd->allowed = 0xffffffff;
1226 goto out;
1227}
1228
1229/*
1230 * Write the security context string representation of
1231 * the context structure `context' into a dynamically
1232 * allocated string of the correct size. Set `*scontext'
1233 * to point to this string and set `*scontext_len' to
1234 * the length of the string.
1235 */
1236static int context_struct_to_string(struct policydb *p,
1237 struct context *context,
1238 char **scontext, u32 *scontext_len)
1239{
1240 char *scontextp;
1241
1242 if (scontext)
1243 *scontext = NULL;
1244 *scontext_len = 0;
1245
1246 if (context->len) {
1247 *scontext_len = context->len;
1248 if (scontext) {
1249 *scontext = kstrdup(context->str, GFP_ATOMIC);
1250 if (!(*scontext))
1251 return -ENOMEM;
1252 }
1253 return 0;
1254 }
1255
1256 /* Compute the size of the context. */
1257 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1258 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1259 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1260 *scontext_len += mls_compute_context_len(p, context);
1261
1262 if (!scontext)
1263 return 0;
1264
1265 /* Allocate space for the context; caller must free this space. */
1266 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1267 if (!scontextp)
1268 return -ENOMEM;
1269 *scontext = scontextp;
1270
1271 /*
1272 * Copy the user name, role name and type name into the context.
1273 */
1274 scontextp += sprintf(scontextp, "%s:%s:%s",
1275 sym_name(p, SYM_USERS, context->user - 1),
1276 sym_name(p, SYM_ROLES, context->role - 1),
1277 sym_name(p, SYM_TYPES, context->type - 1));
1278
1279 mls_sid_to_context(p, context, &scontextp);
1280
1281 *scontextp = 0;
1282
1283 return 0;
1284}
1285
1286static int sidtab_entry_to_string(struct policydb *p,
1287 struct sidtab *sidtab,
1288 struct sidtab_entry *entry,
1289 char **scontext, u32 *scontext_len)
1290{
1291 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1292
1293 if (rc != -ENOENT)
1294 return rc;
1295
1296 rc = context_struct_to_string(p, &entry->context, scontext,
1297 scontext_len);
1298 if (!rc && scontext)
1299 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1300 return rc;
1301}
1302
1303#include "initial_sid_to_string.h"
1304
1305int security_sidtab_hash_stats(char *page)
1306{
1307 struct selinux_policy *policy;
1308 int rc;
1309
1310 if (!selinux_initialized()) {
1311 pr_err("SELinux: %s: called before initial load_policy\n",
1312 __func__);
1313 return -EINVAL;
1314 }
1315
1316 rcu_read_lock();
1317 policy = rcu_dereference(selinux_state.policy);
1318 rc = sidtab_hash_stats(policy->sidtab, page);
1319 rcu_read_unlock();
1320
1321 return rc;
1322}
1323
1324const char *security_get_initial_sid_context(u32 sid)
1325{
1326 if (unlikely(sid > SECINITSID_NUM))
1327 return NULL;
1328 return initial_sid_to_string[sid];
1329}
1330
1331static int security_sid_to_context_core(u32 sid, char **scontext,
1332 u32 *scontext_len, int force,
1333 int only_invalid)
1334{
1335 struct selinux_policy *policy;
1336 struct policydb *policydb;
1337 struct sidtab *sidtab;
1338 struct sidtab_entry *entry;
1339 int rc = 0;
1340
1341 if (scontext)
1342 *scontext = NULL;
1343 *scontext_len = 0;
1344
1345 if (!selinux_initialized()) {
1346 if (sid <= SECINITSID_NUM) {
1347 char *scontextp;
1348 const char *s;
1349
1350 /*
1351 * Before the policy is loaded, translate
1352 * SECINITSID_INIT to "kernel", because systemd and
1353 * libselinux < 2.6 take a getcon_raw() result that is
1354 * both non-null and not "kernel" to mean that a policy
1355 * is already loaded.
1356 */
1357 if (sid == SECINITSID_INIT)
1358 sid = SECINITSID_KERNEL;
1359
1360 s = initial_sid_to_string[sid];
1361 if (!s)
1362 return -EINVAL;
1363 *scontext_len = strlen(s) + 1;
1364 if (!scontext)
1365 return 0;
1366 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1367 if (!scontextp)
1368 return -ENOMEM;
1369 *scontext = scontextp;
1370 return 0;
1371 }
1372 pr_err("SELinux: %s: called before initial "
1373 "load_policy on unknown SID %d\n", __func__, sid);
1374 return -EINVAL;
1375 }
1376 rcu_read_lock();
1377 policy = rcu_dereference(selinux_state.policy);
1378 policydb = &policy->policydb;
1379 sidtab = policy->sidtab;
1380
1381 if (force)
1382 entry = sidtab_search_entry_force(sidtab, sid);
1383 else
1384 entry = sidtab_search_entry(sidtab, sid);
1385 if (!entry) {
1386 pr_err("SELinux: %s: unrecognized SID %d\n",
1387 __func__, sid);
1388 rc = -EINVAL;
1389 goto out_unlock;
1390 }
1391 if (only_invalid && !entry->context.len)
1392 goto out_unlock;
1393
1394 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1395 scontext_len);
1396
1397out_unlock:
1398 rcu_read_unlock();
1399 return rc;
1400
1401}
1402
1403/**
1404 * security_sid_to_context - Obtain a context for a given SID.
1405 * @sid: security identifier, SID
1406 * @scontext: security context
1407 * @scontext_len: length in bytes
1408 *
1409 * Write the string representation of the context associated with @sid
1410 * into a dynamically allocated string of the correct size. Set @scontext
1411 * to point to this string and set @scontext_len to the length of the string.
1412 */
1413int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1414{
1415 return security_sid_to_context_core(sid, scontext,
1416 scontext_len, 0, 0);
1417}
1418
1419int security_sid_to_context_force(u32 sid,
1420 char **scontext, u32 *scontext_len)
1421{
1422 return security_sid_to_context_core(sid, scontext,
1423 scontext_len, 1, 0);
1424}
1425
1426/**
1427 * security_sid_to_context_inval - Obtain a context for a given SID if it
1428 * is invalid.
1429 * @sid: security identifier, SID
1430 * @scontext: security context
1431 * @scontext_len: length in bytes
1432 *
1433 * Write the string representation of the context associated with @sid
1434 * into a dynamically allocated string of the correct size, but only if the
1435 * context is invalid in the current policy. Set @scontext to point to
1436 * this string (or NULL if the context is valid) and set @scontext_len to
1437 * the length of the string (or 0 if the context is valid).
1438 */
1439int security_sid_to_context_inval(u32 sid,
1440 char **scontext, u32 *scontext_len)
1441{
1442 return security_sid_to_context_core(sid, scontext,
1443 scontext_len, 1, 1);
1444}
1445
1446/*
1447 * Caveat: Mutates scontext.
1448 */
1449static int string_to_context_struct(struct policydb *pol,
1450 struct sidtab *sidtabp,
1451 char *scontext,
1452 struct context *ctx,
1453 u32 def_sid)
1454{
1455 struct role_datum *role;
1456 struct type_datum *typdatum;
1457 struct user_datum *usrdatum;
1458 char *scontextp, *p, oldc;
1459 int rc = 0;
1460
1461 context_init(ctx);
1462
1463 /* Parse the security context. */
1464
1465 rc = -EINVAL;
1466 scontextp = scontext;
1467
1468 /* Extract the user. */
1469 p = scontextp;
1470 while (*p && *p != ':')
1471 p++;
1472
1473 if (*p == 0)
1474 goto out;
1475
1476 *p++ = 0;
1477
1478 usrdatum = symtab_search(&pol->p_users, scontextp);
1479 if (!usrdatum)
1480 goto out;
1481
1482 ctx->user = usrdatum->value;
1483
1484 /* Extract role. */
1485 scontextp = p;
1486 while (*p && *p != ':')
1487 p++;
1488
1489 if (*p == 0)
1490 goto out;
1491
1492 *p++ = 0;
1493
1494 role = symtab_search(&pol->p_roles, scontextp);
1495 if (!role)
1496 goto out;
1497 ctx->role = role->value;
1498
1499 /* Extract type. */
1500 scontextp = p;
1501 while (*p && *p != ':')
1502 p++;
1503 oldc = *p;
1504 *p++ = 0;
1505
1506 typdatum = symtab_search(&pol->p_types, scontextp);
1507 if (!typdatum || typdatum->attribute)
1508 goto out;
1509
1510 ctx->type = typdatum->value;
1511
1512 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1513 if (rc)
1514 goto out;
1515
1516 /* Check the validity of the new context. */
1517 rc = -EINVAL;
1518 if (!policydb_context_isvalid(pol, ctx))
1519 goto out;
1520 rc = 0;
1521out:
1522 if (rc)
1523 context_destroy(ctx);
1524 return rc;
1525}
1526
1527static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1528 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1529 int force)
1530{
1531 struct selinux_policy *policy;
1532 struct policydb *policydb;
1533 struct sidtab *sidtab;
1534 char *scontext2, *str = NULL;
1535 struct context context;
1536 int rc = 0;
1537
1538 /* An empty security context is never valid. */
1539 if (!scontext_len)
1540 return -EINVAL;
1541
1542 /* Copy the string to allow changes and ensure a NUL terminator */
1543 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1544 if (!scontext2)
1545 return -ENOMEM;
1546
1547 if (!selinux_initialized()) {
1548 u32 i;
1549
1550 for (i = 1; i < SECINITSID_NUM; i++) {
1551 const char *s = initial_sid_to_string[i];
1552
1553 if (s && !strcmp(s, scontext2)) {
1554 *sid = i;
1555 goto out;
1556 }
1557 }
1558 *sid = SECINITSID_KERNEL;
1559 goto out;
1560 }
1561 *sid = SECSID_NULL;
1562
1563 if (force) {
1564 /* Save another copy for storing in uninterpreted form */
1565 rc = -ENOMEM;
1566 str = kstrdup(scontext2, gfp_flags);
1567 if (!str)
1568 goto out;
1569 }
1570retry:
1571 rcu_read_lock();
1572 policy = rcu_dereference(selinux_state.policy);
1573 policydb = &policy->policydb;
1574 sidtab = policy->sidtab;
1575 rc = string_to_context_struct(policydb, sidtab, scontext2,
1576 &context, def_sid);
1577 if (rc == -EINVAL && force) {
1578 context.str = str;
1579 context.len = strlen(str) + 1;
1580 str = NULL;
1581 } else if (rc)
1582 goto out_unlock;
1583 rc = sidtab_context_to_sid(sidtab, &context, sid);
1584 if (rc == -ESTALE) {
1585 rcu_read_unlock();
1586 if (context.str) {
1587 str = context.str;
1588 context.str = NULL;
1589 }
1590 context_destroy(&context);
1591 goto retry;
1592 }
1593 context_destroy(&context);
1594out_unlock:
1595 rcu_read_unlock();
1596out:
1597 kfree(scontext2);
1598 kfree(str);
1599 return rc;
1600}
1601
1602/**
1603 * security_context_to_sid - Obtain a SID for a given security context.
1604 * @scontext: security context
1605 * @scontext_len: length in bytes
1606 * @sid: security identifier, SID
1607 * @gfp: context for the allocation
1608 *
1609 * Obtains a SID associated with the security context that
1610 * has the string representation specified by @scontext.
1611 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1612 * memory is available, or 0 on success.
1613 */
1614int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1615 gfp_t gfp)
1616{
1617 return security_context_to_sid_core(scontext, scontext_len,
1618 sid, SECSID_NULL, gfp, 0);
1619}
1620
1621int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1622{
1623 return security_context_to_sid(scontext, strlen(scontext),
1624 sid, gfp);
1625}
1626
1627/**
1628 * security_context_to_sid_default - Obtain a SID for a given security context,
1629 * falling back to specified default if needed.
1630 *
1631 * @scontext: security context
1632 * @scontext_len: length in bytes
1633 * @sid: security identifier, SID
1634 * @def_sid: default SID to assign on error
1635 * @gfp_flags: the allocator get-free-page (GFP) flags
1636 *
1637 * Obtains a SID associated with the security context that
1638 * has the string representation specified by @scontext.
1639 * The default SID is passed to the MLS layer to be used to allow
1640 * kernel labeling of the MLS field if the MLS field is not present
1641 * (for upgrading to MLS without full relabel).
1642 * Implicitly forces adding of the context even if it cannot be mapped yet.
1643 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1644 * memory is available, or 0 on success.
1645 */
1646int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1647 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1648{
1649 return security_context_to_sid_core(scontext, scontext_len,
1650 sid, def_sid, gfp_flags, 1);
1651}
1652
1653int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1654 u32 *sid)
1655{
1656 return security_context_to_sid_core(scontext, scontext_len,
1657 sid, SECSID_NULL, GFP_KERNEL, 1);
1658}
1659
1660static int compute_sid_handle_invalid_context(
1661 struct selinux_policy *policy,
1662 struct sidtab_entry *sentry,
1663 struct sidtab_entry *tentry,
1664 u16 tclass,
1665 struct context *newcontext)
1666{
1667 struct policydb *policydb = &policy->policydb;
1668 struct sidtab *sidtab = policy->sidtab;
1669 char *s = NULL, *t = NULL, *n = NULL;
1670 u32 slen, tlen, nlen;
1671 struct audit_buffer *ab;
1672
1673 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1674 goto out;
1675 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1676 goto out;
1677 if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1678 goto out;
1679 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1680 if (!ab)
1681 goto out;
1682 audit_log_format(ab,
1683 "op=security_compute_sid invalid_context=");
1684 /* no need to record the NUL with untrusted strings */
1685 audit_log_n_untrustedstring(ab, n, nlen - 1);
1686 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1687 s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1688 audit_log_end(ab);
1689out:
1690 kfree(s);
1691 kfree(t);
1692 kfree(n);
1693 if (!enforcing_enabled())
1694 return 0;
1695 return -EACCES;
1696}
1697
1698static void filename_compute_type(struct policydb *policydb,
1699 struct context *newcontext,
1700 u32 stype, u32 ttype, u16 tclass,
1701 const char *objname)
1702{
1703 struct filename_trans_key ft;
1704 struct filename_trans_datum *datum;
1705
1706 /*
1707 * Most filename trans rules are going to live in specific directories
1708 * like /dev or /var/run. This bitmap will quickly skip rule searches
1709 * if the ttype does not contain any rules.
1710 */
1711 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1712 return;
1713
1714 ft.ttype = ttype;
1715 ft.tclass = tclass;
1716 ft.name = objname;
1717
1718 datum = policydb_filenametr_search(policydb, &ft);
1719 while (datum) {
1720 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1721 newcontext->type = datum->otype;
1722 return;
1723 }
1724 datum = datum->next;
1725 }
1726}
1727
1728static int security_compute_sid(u32 ssid,
1729 u32 tsid,
1730 u16 orig_tclass,
1731 u16 specified,
1732 const char *objname,
1733 u32 *out_sid,
1734 bool kern)
1735{
1736 struct selinux_policy *policy;
1737 struct policydb *policydb;
1738 struct sidtab *sidtab;
1739 struct class_datum *cladatum;
1740 struct context *scontext, *tcontext, newcontext;
1741 struct sidtab_entry *sentry, *tentry;
1742 struct avtab_key avkey;
1743 struct avtab_node *avnode, *node;
1744 u16 tclass;
1745 int rc = 0;
1746 bool sock;
1747
1748 if (!selinux_initialized()) {
1749 switch (orig_tclass) {
1750 case SECCLASS_PROCESS: /* kernel value */
1751 *out_sid = ssid;
1752 break;
1753 default:
1754 *out_sid = tsid;
1755 break;
1756 }
1757 goto out;
1758 }
1759
1760retry:
1761 cladatum = NULL;
1762 context_init(&newcontext);
1763
1764 rcu_read_lock();
1765
1766 policy = rcu_dereference(selinux_state.policy);
1767
1768 if (kern) {
1769 tclass = unmap_class(&policy->map, orig_tclass);
1770 sock = security_is_socket_class(orig_tclass);
1771 } else {
1772 tclass = orig_tclass;
1773 sock = security_is_socket_class(map_class(&policy->map,
1774 tclass));
1775 }
1776
1777 policydb = &policy->policydb;
1778 sidtab = policy->sidtab;
1779
1780 sentry = sidtab_search_entry(sidtab, ssid);
1781 if (!sentry) {
1782 pr_err("SELinux: %s: unrecognized SID %d\n",
1783 __func__, ssid);
1784 rc = -EINVAL;
1785 goto out_unlock;
1786 }
1787 tentry = sidtab_search_entry(sidtab, tsid);
1788 if (!tentry) {
1789 pr_err("SELinux: %s: unrecognized SID %d\n",
1790 __func__, tsid);
1791 rc = -EINVAL;
1792 goto out_unlock;
1793 }
1794
1795 scontext = &sentry->context;
1796 tcontext = &tentry->context;
1797
1798 if (tclass && tclass <= policydb->p_classes.nprim)
1799 cladatum = policydb->class_val_to_struct[tclass - 1];
1800
1801 /* Set the user identity. */
1802 switch (specified) {
1803 case AVTAB_TRANSITION:
1804 case AVTAB_CHANGE:
1805 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1806 newcontext.user = tcontext->user;
1807 } else {
1808 /* notice this gets both DEFAULT_SOURCE and unset */
1809 /* Use the process user identity. */
1810 newcontext.user = scontext->user;
1811 }
1812 break;
1813 case AVTAB_MEMBER:
1814 /* Use the related object owner. */
1815 newcontext.user = tcontext->user;
1816 break;
1817 }
1818
1819 /* Set the role to default values. */
1820 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1821 newcontext.role = scontext->role;
1822 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1823 newcontext.role = tcontext->role;
1824 } else {
1825 if ((tclass == policydb->process_class) || sock)
1826 newcontext.role = scontext->role;
1827 else
1828 newcontext.role = OBJECT_R_VAL;
1829 }
1830
1831 /* Set the type.
1832 * Look for a type transition/member/change rule.
1833 */
1834 avkey.source_type = scontext->type;
1835 avkey.target_type = tcontext->type;
1836 avkey.target_class = tclass;
1837 avkey.specified = specified;
1838 avnode = avtab_search_node(&policydb->te_avtab, &avkey);
1839
1840 /* If no permanent rule, also check for enabled conditional rules */
1841 if (!avnode) {
1842 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1843 for (; node; node = avtab_search_node_next(node, specified)) {
1844 if (node->key.specified & AVTAB_ENABLED) {
1845 avnode = node;
1846 break;
1847 }
1848 }
1849 }
1850
1851 /* If a permanent rule is found, use the type from
1852 * the type transition/member/change rule. Otherwise,
1853 * set the type to its default values.
1854 */
1855 if (avnode) {
1856 newcontext.type = avnode->datum.u.data;
1857 } else if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1858 newcontext.type = scontext->type;
1859 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1860 newcontext.type = tcontext->type;
1861 } else {
1862 if ((tclass == policydb->process_class) || sock) {
1863 /* Use the type of process. */
1864 newcontext.type = scontext->type;
1865 } else {
1866 /* Use the type of the related object. */
1867 newcontext.type = tcontext->type;
1868 }
1869 }
1870
1871 /* if we have a objname this is a file trans check so check those rules */
1872 if (objname)
1873 filename_compute_type(policydb, &newcontext, scontext->type,
1874 tcontext->type, tclass, objname);
1875
1876 /* Check for class-specific changes. */
1877 if (specified & AVTAB_TRANSITION) {
1878 /* Look for a role transition rule. */
1879 struct role_trans_datum *rtd;
1880 struct role_trans_key rtk = {
1881 .role = scontext->role,
1882 .type = tcontext->type,
1883 .tclass = tclass,
1884 };
1885
1886 rtd = policydb_roletr_search(policydb, &rtk);
1887 if (rtd)
1888 newcontext.role = rtd->new_role;
1889 }
1890
1891 /* Set the MLS attributes.
1892 This is done last because it may allocate memory. */
1893 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1894 &newcontext, sock);
1895 if (rc)
1896 goto out_unlock;
1897
1898 /* Check the validity of the context. */
1899 if (!policydb_context_isvalid(policydb, &newcontext)) {
1900 rc = compute_sid_handle_invalid_context(policy, sentry,
1901 tentry, tclass,
1902 &newcontext);
1903 if (rc)
1904 goto out_unlock;
1905 }
1906 /* Obtain the sid for the context. */
1907 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1908 if (rc == -ESTALE) {
1909 rcu_read_unlock();
1910 context_destroy(&newcontext);
1911 goto retry;
1912 }
1913out_unlock:
1914 rcu_read_unlock();
1915 context_destroy(&newcontext);
1916out:
1917 return rc;
1918}
1919
1920/**
1921 * security_transition_sid - Compute the SID for a new subject/object.
1922 * @ssid: source security identifier
1923 * @tsid: target security identifier
1924 * @tclass: target security class
1925 * @qstr: object name
1926 * @out_sid: security identifier for new subject/object
1927 *
1928 * Compute a SID to use for labeling a new subject or object in the
1929 * class @tclass based on a SID pair (@ssid, @tsid).
1930 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1931 * if insufficient memory is available, or %0 if the new SID was
1932 * computed successfully.
1933 */
1934int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1935 const struct qstr *qstr, u32 *out_sid)
1936{
1937 return security_compute_sid(ssid, tsid, tclass,
1938 AVTAB_TRANSITION,
1939 qstr ? qstr->name : NULL, out_sid, true);
1940}
1941
1942int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1943 const char *objname, u32 *out_sid)
1944{
1945 return security_compute_sid(ssid, tsid, tclass,
1946 AVTAB_TRANSITION,
1947 objname, out_sid, false);
1948}
1949
1950/**
1951 * security_member_sid - Compute the SID for member selection.
1952 * @ssid: source security identifier
1953 * @tsid: target security identifier
1954 * @tclass: target security class
1955 * @out_sid: security identifier for selected member
1956 *
1957 * Compute a SID to use when selecting a member of a polyinstantiated
1958 * object of class @tclass based on a SID pair (@ssid, @tsid).
1959 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1960 * if insufficient memory is available, or %0 if the SID was
1961 * computed successfully.
1962 */
1963int security_member_sid(u32 ssid,
1964 u32 tsid,
1965 u16 tclass,
1966 u32 *out_sid)
1967{
1968 return security_compute_sid(ssid, tsid, tclass,
1969 AVTAB_MEMBER, NULL,
1970 out_sid, false);
1971}
1972
1973/**
1974 * security_change_sid - Compute the SID for object relabeling.
1975 * @ssid: source security identifier
1976 * @tsid: target security identifier
1977 * @tclass: target security class
1978 * @out_sid: security identifier for selected member
1979 *
1980 * Compute a SID to use for relabeling an object of class @tclass
1981 * based on a SID pair (@ssid, @tsid).
1982 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1983 * if insufficient memory is available, or %0 if the SID was
1984 * computed successfully.
1985 */
1986int security_change_sid(u32 ssid,
1987 u32 tsid,
1988 u16 tclass,
1989 u32 *out_sid)
1990{
1991 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1992 out_sid, false);
1993}
1994
1995static inline int convert_context_handle_invalid_context(
1996 struct policydb *policydb,
1997 struct context *context)
1998{
1999 char *s;
2000 u32 len;
2001
2002 if (enforcing_enabled())
2003 return -EINVAL;
2004
2005 if (!context_struct_to_string(policydb, context, &s, &len)) {
2006 pr_warn("SELinux: Context %s would be invalid if enforcing\n",
2007 s);
2008 kfree(s);
2009 }
2010 return 0;
2011}
2012
2013/**
2014 * services_convert_context - Convert a security context across policies.
2015 * @args: populated convert_context_args struct
2016 * @oldc: original context
2017 * @newc: converted context
2018 * @gfp_flags: allocation flags
2019 *
2020 * Convert the values in the security context structure @oldc from the values
2021 * specified in the policy @args->oldp to the values specified in the policy
2022 * @args->newp, storing the new context in @newc, and verifying that the
2023 * context is valid under the new policy.
2024 */
2025int services_convert_context(struct convert_context_args *args,
2026 struct context *oldc, struct context *newc,
2027 gfp_t gfp_flags)
2028{
2029 struct ocontext *oc;
2030 struct role_datum *role;
2031 struct type_datum *typdatum;
2032 struct user_datum *usrdatum;
2033 char *s;
2034 u32 len;
2035 int rc;
2036
2037 if (oldc->str) {
2038 s = kstrdup(oldc->str, gfp_flags);
2039 if (!s)
2040 return -ENOMEM;
2041
2042 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL);
2043 if (rc == -EINVAL) {
2044 /*
2045 * Retain string representation for later mapping.
2046 *
2047 * IMPORTANT: We need to copy the contents of oldc->str
2048 * back into s again because string_to_context_struct()
2049 * may have garbled it.
2050 */
2051 memcpy(s, oldc->str, oldc->len);
2052 context_init(newc);
2053 newc->str = s;
2054 newc->len = oldc->len;
2055 return 0;
2056 }
2057 kfree(s);
2058 if (rc) {
2059 /* Other error condition, e.g. ENOMEM. */
2060 pr_err("SELinux: Unable to map context %s, rc = %d.\n",
2061 oldc->str, -rc);
2062 return rc;
2063 }
2064 pr_info("SELinux: Context %s became valid (mapped).\n",
2065 oldc->str);
2066 return 0;
2067 }
2068
2069 context_init(newc);
2070
2071 /* Convert the user. */
2072 usrdatum = symtab_search(&args->newp->p_users,
2073 sym_name(args->oldp, SYM_USERS, oldc->user - 1));
2074 if (!usrdatum)
2075 goto bad;
2076 newc->user = usrdatum->value;
2077
2078 /* Convert the role. */
2079 role = symtab_search(&args->newp->p_roles,
2080 sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2081 if (!role)
2082 goto bad;
2083 newc->role = role->value;
2084
2085 /* Convert the type. */
2086 typdatum = symtab_search(&args->newp->p_types,
2087 sym_name(args->oldp, SYM_TYPES, oldc->type - 1));
2088 if (!typdatum)
2089 goto bad;
2090 newc->type = typdatum->value;
2091
2092 /* Convert the MLS fields if dealing with MLS policies */
2093 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2094 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2095 if (rc)
2096 goto bad;
2097 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2098 /*
2099 * Switching between non-MLS and MLS policy:
2100 * ensure that the MLS fields of the context for all
2101 * existing entries in the sidtab are filled in with a
2102 * suitable default value, likely taken from one of the
2103 * initial SIDs.
2104 */
2105 oc = args->newp->ocontexts[OCON_ISID];
2106 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2107 oc = oc->next;
2108 if (!oc) {
2109 pr_err("SELinux: unable to look up"
2110 " the initial SIDs list\n");
2111 goto bad;
2112 }
2113 rc = mls_range_set(newc, &oc->context[0].range);
2114 if (rc)
2115 goto bad;
2116 }
2117
2118 /* Check the validity of the new context. */
2119 if (!policydb_context_isvalid(args->newp, newc)) {
2120 rc = convert_context_handle_invalid_context(args->oldp, oldc);
2121 if (rc)
2122 goto bad;
2123 }
2124
2125 return 0;
2126bad:
2127 /* Map old representation to string and save it. */
2128 rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2129 if (rc)
2130 return rc;
2131 context_destroy(newc);
2132 newc->str = s;
2133 newc->len = len;
2134 pr_info("SELinux: Context %s became invalid (unmapped).\n",
2135 newc->str);
2136 return 0;
2137}
2138
2139static void security_load_policycaps(struct selinux_policy *policy)
2140{
2141 struct policydb *p;
2142 unsigned int i;
2143 struct ebitmap_node *node;
2144
2145 p = &policy->policydb;
2146
2147 for (i = 0; i < ARRAY_SIZE(selinux_state.policycap); i++)
2148 WRITE_ONCE(selinux_state.policycap[i],
2149 ebitmap_get_bit(&p->policycaps, i));
2150
2151 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2152 pr_info("SELinux: policy capability %s=%d\n",
2153 selinux_policycap_names[i],
2154 ebitmap_get_bit(&p->policycaps, i));
2155
2156 ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2157 if (i >= ARRAY_SIZE(selinux_policycap_names))
2158 pr_info("SELinux: unknown policy capability %u\n",
2159 i);
2160 }
2161}
2162
2163static int security_preserve_bools(struct selinux_policy *oldpolicy,
2164 struct selinux_policy *newpolicy);
2165
2166static void selinux_policy_free(struct selinux_policy *policy)
2167{
2168 if (!policy)
2169 return;
2170
2171 sidtab_destroy(policy->sidtab);
2172 kfree(policy->map.mapping);
2173 policydb_destroy(&policy->policydb);
2174 kfree(policy->sidtab);
2175 kfree(policy);
2176}
2177
2178static void selinux_policy_cond_free(struct selinux_policy *policy)
2179{
2180 cond_policydb_destroy_dup(&policy->policydb);
2181 kfree(policy);
2182}
2183
2184void selinux_policy_cancel(struct selinux_load_state *load_state)
2185{
2186 struct selinux_state *state = &selinux_state;
2187 struct selinux_policy *oldpolicy;
2188
2189 oldpolicy = rcu_dereference_protected(state->policy,
2190 lockdep_is_held(&state->policy_mutex));
2191
2192 sidtab_cancel_convert(oldpolicy->sidtab);
2193 selinux_policy_free(load_state->policy);
2194 kfree(load_state->convert_data);
2195}
2196
2197static void selinux_notify_policy_change(u32 seqno)
2198{
2199 /* Flush external caches and notify userspace of policy load */
2200 avc_ss_reset(seqno);
2201 selnl_notify_policyload(seqno);
2202 selinux_status_update_policyload(seqno);
2203 selinux_netlbl_cache_invalidate();
2204 selinux_xfrm_notify_policyload();
2205 selinux_ima_measure_state_locked();
2206}
2207
2208void selinux_policy_commit(struct selinux_load_state *load_state)
2209{
2210 struct selinux_state *state = &selinux_state;
2211 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
2212 unsigned long flags;
2213 u32 seqno;
2214
2215 oldpolicy = rcu_dereference_protected(state->policy,
2216 lockdep_is_held(&state->policy_mutex));
2217
2218 /* If switching between different policy types, log MLS status */
2219 if (oldpolicy) {
2220 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
2221 pr_info("SELinux: Disabling MLS support...\n");
2222 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
2223 pr_info("SELinux: Enabling MLS support...\n");
2224 }
2225
2226 /* Set latest granting seqno for new policy. */
2227 if (oldpolicy)
2228 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
2229 else
2230 newpolicy->latest_granting = 1;
2231 seqno = newpolicy->latest_granting;
2232
2233 /* Install the new policy. */
2234 if (oldpolicy) {
2235 sidtab_freeze_begin(oldpolicy->sidtab, &flags);
2236 rcu_assign_pointer(state->policy, newpolicy);
2237 sidtab_freeze_end(oldpolicy->sidtab, &flags);
2238 } else {
2239 rcu_assign_pointer(state->policy, newpolicy);
2240 }
2241
2242 /* Load the policycaps from the new policy */
2243 security_load_policycaps(newpolicy);
2244
2245 if (!selinux_initialized()) {
2246 /*
2247 * After first policy load, the security server is
2248 * marked as initialized and ready to handle requests and
2249 * any objects created prior to policy load are then labeled.
2250 */
2251 selinux_mark_initialized();
2252 selinux_complete_init();
2253 }
2254
2255 /* Free the old policy */
2256 synchronize_rcu();
2257 selinux_policy_free(oldpolicy);
2258 kfree(load_state->convert_data);
2259
2260 /* Notify others of the policy change */
2261 selinux_notify_policy_change(seqno);
2262}
2263
2264/**
2265 * security_load_policy - Load a security policy configuration.
2266 * @data: binary policy data
2267 * @len: length of data in bytes
2268 * @load_state: policy load state
2269 *
2270 * Load a new set of security policy configuration data,
2271 * validate it and convert the SID table as necessary.
2272 * This function will flush the access vector cache after
2273 * loading the new policy.
2274 */
2275int security_load_policy(void *data, size_t len,
2276 struct selinux_load_state *load_state)
2277{
2278 struct selinux_state *state = &selinux_state;
2279 struct selinux_policy *newpolicy, *oldpolicy;
2280 struct selinux_policy_convert_data *convert_data;
2281 int rc = 0;
2282 struct policy_file file = { data, len }, *fp = &file;
2283
2284 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2285 if (!newpolicy)
2286 return -ENOMEM;
2287
2288 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2289 if (!newpolicy->sidtab) {
2290 rc = -ENOMEM;
2291 goto err_policy;
2292 }
2293
2294 rc = policydb_read(&newpolicy->policydb, fp);
2295 if (rc)
2296 goto err_sidtab;
2297
2298 newpolicy->policydb.len = len;
2299 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2300 &newpolicy->map);
2301 if (rc)
2302 goto err_policydb;
2303
2304 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2305 if (rc) {
2306 pr_err("SELinux: unable to load the initial SIDs\n");
2307 goto err_mapping;
2308 }
2309
2310 if (!selinux_initialized()) {
2311 /* First policy load, so no need to preserve state from old policy */
2312 load_state->policy = newpolicy;
2313 load_state->convert_data = NULL;
2314 return 0;
2315 }
2316
2317 oldpolicy = rcu_dereference_protected(state->policy,
2318 lockdep_is_held(&state->policy_mutex));
2319
2320 /* Preserve active boolean values from the old policy */
2321 rc = security_preserve_bools(oldpolicy, newpolicy);
2322 if (rc) {
2323 pr_err("SELinux: unable to preserve booleans\n");
2324 goto err_free_isids;
2325 }
2326
2327 /*
2328 * Convert the internal representations of contexts
2329 * in the new SID table.
2330 */
2331
2332 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2333 if (!convert_data) {
2334 rc = -ENOMEM;
2335 goto err_free_isids;
2336 }
2337
2338 convert_data->args.oldp = &oldpolicy->policydb;
2339 convert_data->args.newp = &newpolicy->policydb;
2340
2341 convert_data->sidtab_params.args = &convert_data->args;
2342 convert_data->sidtab_params.target = newpolicy->sidtab;
2343
2344 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2345 if (rc) {
2346 pr_err("SELinux: unable to convert the internal"
2347 " representation of contexts in the new SID"
2348 " table\n");
2349 goto err_free_convert_data;
2350 }
2351
2352 load_state->policy = newpolicy;
2353 load_state->convert_data = convert_data;
2354 return 0;
2355
2356err_free_convert_data:
2357 kfree(convert_data);
2358err_free_isids:
2359 sidtab_destroy(newpolicy->sidtab);
2360err_mapping:
2361 kfree(newpolicy->map.mapping);
2362err_policydb:
2363 policydb_destroy(&newpolicy->policydb);
2364err_sidtab:
2365 kfree(newpolicy->sidtab);
2366err_policy:
2367 kfree(newpolicy);
2368
2369 return rc;
2370}
2371
2372/**
2373 * ocontext_to_sid - Helper to safely get sid for an ocontext
2374 * @sidtab: SID table
2375 * @c: ocontext structure
2376 * @index: index of the context entry (0 or 1)
2377 * @out_sid: pointer to the resulting SID value
2378 *
2379 * For all ocontexts except OCON_ISID the SID fields are populated
2380 * on-demand when needed. Since updating the SID value is an SMP-sensitive
2381 * operation, this helper must be used to do that safely.
2382 *
2383 * WARNING: This function may return -ESTALE, indicating that the caller
2384 * must retry the operation after re-acquiring the policy pointer!
2385 */
2386static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
2387 size_t index, u32 *out_sid)
2388{
2389 int rc;
2390 u32 sid;
2391
2392 /* Ensure the associated sidtab entry is visible to this thread. */
2393 sid = smp_load_acquire(&c->sid[index]);
2394 if (!sid) {
2395 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
2396 if (rc)
2397 return rc;
2398
2399 /*
2400 * Ensure the new sidtab entry is visible to other threads
2401 * when they see the SID.
2402 */
2403 smp_store_release(&c->sid[index], sid);
2404 }
2405 *out_sid = sid;
2406 return 0;
2407}
2408
2409/**
2410 * security_port_sid - Obtain the SID for a port.
2411 * @protocol: protocol number
2412 * @port: port number
2413 * @out_sid: security identifier
2414 */
2415int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2416{
2417 struct selinux_policy *policy;
2418 struct policydb *policydb;
2419 struct sidtab *sidtab;
2420 struct ocontext *c;
2421 int rc;
2422
2423 if (!selinux_initialized()) {
2424 *out_sid = SECINITSID_PORT;
2425 return 0;
2426 }
2427
2428retry:
2429 rc = 0;
2430 rcu_read_lock();
2431 policy = rcu_dereference(selinux_state.policy);
2432 policydb = &policy->policydb;
2433 sidtab = policy->sidtab;
2434
2435 c = policydb->ocontexts[OCON_PORT];
2436 while (c) {
2437 if (c->u.port.protocol == protocol &&
2438 c->u.port.low_port <= port &&
2439 c->u.port.high_port >= port)
2440 break;
2441 c = c->next;
2442 }
2443
2444 if (c) {
2445 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2446 if (rc == -ESTALE) {
2447 rcu_read_unlock();
2448 goto retry;
2449 }
2450 if (rc)
2451 goto out;
2452 } else {
2453 *out_sid = SECINITSID_PORT;
2454 }
2455
2456out:
2457 rcu_read_unlock();
2458 return rc;
2459}
2460
2461/**
2462 * security_ib_pkey_sid - Obtain the SID for a pkey.
2463 * @subnet_prefix: Subnet Prefix
2464 * @pkey_num: pkey number
2465 * @out_sid: security identifier
2466 */
2467int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2468{
2469 struct selinux_policy *policy;
2470 struct policydb *policydb;
2471 struct sidtab *sidtab;
2472 struct ocontext *c;
2473 int rc;
2474
2475 if (!selinux_initialized()) {
2476 *out_sid = SECINITSID_UNLABELED;
2477 return 0;
2478 }
2479
2480retry:
2481 rc = 0;
2482 rcu_read_lock();
2483 policy = rcu_dereference(selinux_state.policy);
2484 policydb = &policy->policydb;
2485 sidtab = policy->sidtab;
2486
2487 c = policydb->ocontexts[OCON_IBPKEY];
2488 while (c) {
2489 if (c->u.ibpkey.low_pkey <= pkey_num &&
2490 c->u.ibpkey.high_pkey >= pkey_num &&
2491 c->u.ibpkey.subnet_prefix == subnet_prefix)
2492 break;
2493
2494 c = c->next;
2495 }
2496
2497 if (c) {
2498 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2499 if (rc == -ESTALE) {
2500 rcu_read_unlock();
2501 goto retry;
2502 }
2503 if (rc)
2504 goto out;
2505 } else
2506 *out_sid = SECINITSID_UNLABELED;
2507
2508out:
2509 rcu_read_unlock();
2510 return rc;
2511}
2512
2513/**
2514 * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2515 * @dev_name: device name
2516 * @port_num: port number
2517 * @out_sid: security identifier
2518 */
2519int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid)
2520{
2521 struct selinux_policy *policy;
2522 struct policydb *policydb;
2523 struct sidtab *sidtab;
2524 struct ocontext *c;
2525 int rc;
2526
2527 if (!selinux_initialized()) {
2528 *out_sid = SECINITSID_UNLABELED;
2529 return 0;
2530 }
2531
2532retry:
2533 rc = 0;
2534 rcu_read_lock();
2535 policy = rcu_dereference(selinux_state.policy);
2536 policydb = &policy->policydb;
2537 sidtab = policy->sidtab;
2538
2539 c = policydb->ocontexts[OCON_IBENDPORT];
2540 while (c) {
2541 if (c->u.ibendport.port == port_num &&
2542 !strncmp(c->u.ibendport.dev_name,
2543 dev_name,
2544 IB_DEVICE_NAME_MAX))
2545 break;
2546
2547 c = c->next;
2548 }
2549
2550 if (c) {
2551 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2552 if (rc == -ESTALE) {
2553 rcu_read_unlock();
2554 goto retry;
2555 }
2556 if (rc)
2557 goto out;
2558 } else
2559 *out_sid = SECINITSID_UNLABELED;
2560
2561out:
2562 rcu_read_unlock();
2563 return rc;
2564}
2565
2566/**
2567 * security_netif_sid - Obtain the SID for a network interface.
2568 * @name: interface name
2569 * @if_sid: interface SID
2570 */
2571int security_netif_sid(char *name, u32 *if_sid)
2572{
2573 struct selinux_policy *policy;
2574 struct policydb *policydb;
2575 struct sidtab *sidtab;
2576 int rc;
2577 struct ocontext *c;
2578
2579 if (!selinux_initialized()) {
2580 *if_sid = SECINITSID_NETIF;
2581 return 0;
2582 }
2583
2584retry:
2585 rc = 0;
2586 rcu_read_lock();
2587 policy = rcu_dereference(selinux_state.policy);
2588 policydb = &policy->policydb;
2589 sidtab = policy->sidtab;
2590
2591 c = policydb->ocontexts[OCON_NETIF];
2592 while (c) {
2593 if (strcmp(name, c->u.name) == 0)
2594 break;
2595 c = c->next;
2596 }
2597
2598 if (c) {
2599 rc = ocontext_to_sid(sidtab, c, 0, if_sid);
2600 if (rc == -ESTALE) {
2601 rcu_read_unlock();
2602 goto retry;
2603 }
2604 if (rc)
2605 goto out;
2606 } else
2607 *if_sid = SECINITSID_NETIF;
2608
2609out:
2610 rcu_read_unlock();
2611 return rc;
2612}
2613
2614static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2615{
2616 int i, fail = 0;
2617
2618 for (i = 0; i < 4; i++)
2619 if (addr[i] != (input[i] & mask[i])) {
2620 fail = 1;
2621 break;
2622 }
2623
2624 return !fail;
2625}
2626
2627/**
2628 * security_node_sid - Obtain the SID for a node (host).
2629 * @domain: communication domain aka address family
2630 * @addrp: address
2631 * @addrlen: address length in bytes
2632 * @out_sid: security identifier
2633 */
2634int security_node_sid(u16 domain,
2635 void *addrp,
2636 u32 addrlen,
2637 u32 *out_sid)
2638{
2639 struct selinux_policy *policy;
2640 struct policydb *policydb;
2641 struct sidtab *sidtab;
2642 int rc;
2643 struct ocontext *c;
2644
2645 if (!selinux_initialized()) {
2646 *out_sid = SECINITSID_NODE;
2647 return 0;
2648 }
2649
2650retry:
2651 rcu_read_lock();
2652 policy = rcu_dereference(selinux_state.policy);
2653 policydb = &policy->policydb;
2654 sidtab = policy->sidtab;
2655
2656 switch (domain) {
2657 case AF_INET: {
2658 u32 addr;
2659
2660 rc = -EINVAL;
2661 if (addrlen != sizeof(u32))
2662 goto out;
2663
2664 addr = *((u32 *)addrp);
2665
2666 c = policydb->ocontexts[OCON_NODE];
2667 while (c) {
2668 if (c->u.node.addr == (addr & c->u.node.mask))
2669 break;
2670 c = c->next;
2671 }
2672 break;
2673 }
2674
2675 case AF_INET6:
2676 rc = -EINVAL;
2677 if (addrlen != sizeof(u64) * 2)
2678 goto out;
2679 c = policydb->ocontexts[OCON_NODE6];
2680 while (c) {
2681 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2682 c->u.node6.mask))
2683 break;
2684 c = c->next;
2685 }
2686 break;
2687
2688 default:
2689 rc = 0;
2690 *out_sid = SECINITSID_NODE;
2691 goto out;
2692 }
2693
2694 if (c) {
2695 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2696 if (rc == -ESTALE) {
2697 rcu_read_unlock();
2698 goto retry;
2699 }
2700 if (rc)
2701 goto out;
2702 } else {
2703 *out_sid = SECINITSID_NODE;
2704 }
2705
2706 rc = 0;
2707out:
2708 rcu_read_unlock();
2709 return rc;
2710}
2711
2712#define SIDS_NEL 25
2713
2714/**
2715 * security_get_user_sids - Obtain reachable SIDs for a user.
2716 * @fromsid: starting SID
2717 * @username: username
2718 * @sids: array of reachable SIDs for user
2719 * @nel: number of elements in @sids
2720 *
2721 * Generate the set of SIDs for legal security contexts
2722 * for a given user that can be reached by @fromsid.
2723 * Set *@sids to point to a dynamically allocated
2724 * array containing the set of SIDs. Set *@nel to the
2725 * number of elements in the array.
2726 */
2727
2728int security_get_user_sids(u32 fromsid,
2729 char *username,
2730 u32 **sids,
2731 u32 *nel)
2732{
2733 struct selinux_policy *policy;
2734 struct policydb *policydb;
2735 struct sidtab *sidtab;
2736 struct context *fromcon, usercon;
2737 u32 *mysids = NULL, *mysids2, sid;
2738 u32 i, j, mynel, maxnel = SIDS_NEL;
2739 struct user_datum *user;
2740 struct role_datum *role;
2741 struct ebitmap_node *rnode, *tnode;
2742 int rc;
2743
2744 *sids = NULL;
2745 *nel = 0;
2746
2747 if (!selinux_initialized())
2748 return 0;
2749
2750 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2751 if (!mysids)
2752 return -ENOMEM;
2753
2754retry:
2755 mynel = 0;
2756 rcu_read_lock();
2757 policy = rcu_dereference(selinux_state.policy);
2758 policydb = &policy->policydb;
2759 sidtab = policy->sidtab;
2760
2761 context_init(&usercon);
2762
2763 rc = -EINVAL;
2764 fromcon = sidtab_search(sidtab, fromsid);
2765 if (!fromcon)
2766 goto out_unlock;
2767
2768 rc = -EINVAL;
2769 user = symtab_search(&policydb->p_users, username);
2770 if (!user)
2771 goto out_unlock;
2772
2773 usercon.user = user->value;
2774
2775 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2776 role = policydb->role_val_to_struct[i];
2777 usercon.role = i + 1;
2778 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2779 usercon.type = j + 1;
2780
2781 if (mls_setup_user_range(policydb, fromcon, user,
2782 &usercon))
2783 continue;
2784
2785 rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2786 if (rc == -ESTALE) {
2787 rcu_read_unlock();
2788 goto retry;
2789 }
2790 if (rc)
2791 goto out_unlock;
2792 if (mynel < maxnel) {
2793 mysids[mynel++] = sid;
2794 } else {
2795 rc = -ENOMEM;
2796 maxnel += SIDS_NEL;
2797 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2798 if (!mysids2)
2799 goto out_unlock;
2800 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2801 kfree(mysids);
2802 mysids = mysids2;
2803 mysids[mynel++] = sid;
2804 }
2805 }
2806 }
2807 rc = 0;
2808out_unlock:
2809 rcu_read_unlock();
2810 if (rc || !mynel) {
2811 kfree(mysids);
2812 return rc;
2813 }
2814
2815 rc = -ENOMEM;
2816 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2817 if (!mysids2) {
2818 kfree(mysids);
2819 return rc;
2820 }
2821 for (i = 0, j = 0; i < mynel; i++) {
2822 struct av_decision dummy_avd;
2823 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2824 SECCLASS_PROCESS, /* kernel value */
2825 PROCESS__TRANSITION, AVC_STRICT,
2826 &dummy_avd);
2827 if (!rc)
2828 mysids2[j++] = mysids[i];
2829 cond_resched();
2830 }
2831 kfree(mysids);
2832 *sids = mysids2;
2833 *nel = j;
2834 return 0;
2835}
2836
2837/**
2838 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2839 * @policy: policy
2840 * @fstype: filesystem type
2841 * @path: path from root of mount
2842 * @orig_sclass: file security class
2843 * @sid: SID for path
2844 *
2845 * Obtain a SID to use for a file in a filesystem that
2846 * cannot support xattr or use a fixed labeling behavior like
2847 * transition SIDs or task SIDs.
2848 *
2849 * WARNING: This function may return -ESTALE, indicating that the caller
2850 * must retry the operation after re-acquiring the policy pointer!
2851 */
2852static inline int __security_genfs_sid(struct selinux_policy *policy,
2853 const char *fstype,
2854 const char *path,
2855 u16 orig_sclass,
2856 u32 *sid)
2857{
2858 struct policydb *policydb = &policy->policydb;
2859 struct sidtab *sidtab = policy->sidtab;
2860 u16 sclass;
2861 struct genfs *genfs;
2862 struct ocontext *c;
2863 int cmp = 0;
2864
2865 while (path[0] == '/' && path[1] == '/')
2866 path++;
2867
2868 sclass = unmap_class(&policy->map, orig_sclass);
2869 *sid = SECINITSID_UNLABELED;
2870
2871 for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2872 cmp = strcmp(fstype, genfs->fstype);
2873 if (cmp <= 0)
2874 break;
2875 }
2876
2877 if (!genfs || cmp)
2878 return -ENOENT;
2879
2880 for (c = genfs->head; c; c = c->next) {
2881 size_t len = strlen(c->u.name);
2882 if ((!c->v.sclass || sclass == c->v.sclass) &&
2883 (strncmp(c->u.name, path, len) == 0))
2884 break;
2885 }
2886
2887 if (!c)
2888 return -ENOENT;
2889
2890 return ocontext_to_sid(sidtab, c, 0, sid);
2891}
2892
2893/**
2894 * security_genfs_sid - Obtain a SID for a file in a filesystem
2895 * @fstype: filesystem type
2896 * @path: path from root of mount
2897 * @orig_sclass: file security class
2898 * @sid: SID for path
2899 *
2900 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2901 * it afterward.
2902 */
2903int security_genfs_sid(const char *fstype,
2904 const char *path,
2905 u16 orig_sclass,
2906 u32 *sid)
2907{
2908 struct selinux_policy *policy;
2909 int retval;
2910
2911 if (!selinux_initialized()) {
2912 *sid = SECINITSID_UNLABELED;
2913 return 0;
2914 }
2915
2916 do {
2917 rcu_read_lock();
2918 policy = rcu_dereference(selinux_state.policy);
2919 retval = __security_genfs_sid(policy, fstype, path,
2920 orig_sclass, sid);
2921 rcu_read_unlock();
2922 } while (retval == -ESTALE);
2923 return retval;
2924}
2925
2926int selinux_policy_genfs_sid(struct selinux_policy *policy,
2927 const char *fstype,
2928 const char *path,
2929 u16 orig_sclass,
2930 u32 *sid)
2931{
2932 /* no lock required, policy is not yet accessible by other threads */
2933 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2934}
2935
2936/**
2937 * security_fs_use - Determine how to handle labeling for a filesystem.
2938 * @sb: superblock in question
2939 */
2940int security_fs_use(struct super_block *sb)
2941{
2942 struct selinux_policy *policy;
2943 struct policydb *policydb;
2944 struct sidtab *sidtab;
2945 int rc;
2946 struct ocontext *c;
2947 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2948 const char *fstype = sb->s_type->name;
2949
2950 if (!selinux_initialized()) {
2951 sbsec->behavior = SECURITY_FS_USE_NONE;
2952 sbsec->sid = SECINITSID_UNLABELED;
2953 return 0;
2954 }
2955
2956retry:
2957 rcu_read_lock();
2958 policy = rcu_dereference(selinux_state.policy);
2959 policydb = &policy->policydb;
2960 sidtab = policy->sidtab;
2961
2962 c = policydb->ocontexts[OCON_FSUSE];
2963 while (c) {
2964 if (strcmp(fstype, c->u.name) == 0)
2965 break;
2966 c = c->next;
2967 }
2968
2969 if (c) {
2970 sbsec->behavior = c->v.behavior;
2971 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
2972 if (rc == -ESTALE) {
2973 rcu_read_unlock();
2974 goto retry;
2975 }
2976 if (rc)
2977 goto out;
2978 } else {
2979 rc = __security_genfs_sid(policy, fstype, "/",
2980 SECCLASS_DIR, &sbsec->sid);
2981 if (rc == -ESTALE) {
2982 rcu_read_unlock();
2983 goto retry;
2984 }
2985 if (rc) {
2986 sbsec->behavior = SECURITY_FS_USE_NONE;
2987 rc = 0;
2988 } else {
2989 sbsec->behavior = SECURITY_FS_USE_GENFS;
2990 }
2991 }
2992
2993out:
2994 rcu_read_unlock();
2995 return rc;
2996}
2997
2998int security_get_bools(struct selinux_policy *policy,
2999 u32 *len, char ***names, int **values)
3000{
3001 struct policydb *policydb;
3002 u32 i;
3003 int rc;
3004
3005 policydb = &policy->policydb;
3006
3007 *names = NULL;
3008 *values = NULL;
3009
3010 rc = 0;
3011 *len = policydb->p_bools.nprim;
3012 if (!*len)
3013 goto out;
3014
3015 rc = -ENOMEM;
3016 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
3017 if (!*names)
3018 goto err;
3019
3020 rc = -ENOMEM;
3021 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
3022 if (!*values)
3023 goto err;
3024
3025 for (i = 0; i < *len; i++) {
3026 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3027
3028 rc = -ENOMEM;
3029 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3030 GFP_ATOMIC);
3031 if (!(*names)[i])
3032 goto err;
3033 }
3034 rc = 0;
3035out:
3036 return rc;
3037err:
3038 if (*names) {
3039 for (i = 0; i < *len; i++)
3040 kfree((*names)[i]);
3041 kfree(*names);
3042 }
3043 kfree(*values);
3044 *len = 0;
3045 *names = NULL;
3046 *values = NULL;
3047 goto out;
3048}
3049
3050
3051int security_set_bools(u32 len, int *values)
3052{
3053 struct selinux_state *state = &selinux_state;
3054 struct selinux_policy *newpolicy, *oldpolicy;
3055 int rc;
3056 u32 i, seqno = 0;
3057
3058 if (!selinux_initialized())
3059 return -EINVAL;
3060
3061 oldpolicy = rcu_dereference_protected(state->policy,
3062 lockdep_is_held(&state->policy_mutex));
3063
3064 /* Consistency check on number of booleans, should never fail */
3065 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3066 return -EINVAL;
3067
3068 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3069 if (!newpolicy)
3070 return -ENOMEM;
3071
3072 /*
3073 * Deep copy only the parts of the policydb that might be
3074 * modified as a result of changing booleans.
3075 */
3076 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3077 if (rc) {
3078 kfree(newpolicy);
3079 return -ENOMEM;
3080 }
3081
3082 /* Update the boolean states in the copy */
3083 for (i = 0; i < len; i++) {
3084 int new_state = !!values[i];
3085 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3086
3087 if (new_state != old_state) {
3088 audit_log(audit_context(), GFP_ATOMIC,
3089 AUDIT_MAC_CONFIG_CHANGE,
3090 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3091 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3092 new_state,
3093 old_state,
3094 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3095 audit_get_sessionid(current));
3096 newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3097 }
3098 }
3099
3100 /* Re-evaluate the conditional rules in the copy */
3101 evaluate_cond_nodes(&newpolicy->policydb);
3102
3103 /* Set latest granting seqno for new policy */
3104 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3105 seqno = newpolicy->latest_granting;
3106
3107 /* Install the new policy */
3108 rcu_assign_pointer(state->policy, newpolicy);
3109
3110 /*
3111 * Free the conditional portions of the old policydb
3112 * that were copied for the new policy, and the oldpolicy
3113 * structure itself but not what it references.
3114 */
3115 synchronize_rcu();
3116 selinux_policy_cond_free(oldpolicy);
3117
3118 /* Notify others of the policy change */
3119 selinux_notify_policy_change(seqno);
3120 return 0;
3121}
3122
3123int security_get_bool_value(u32 index)
3124{
3125 struct selinux_policy *policy;
3126 struct policydb *policydb;
3127 int rc;
3128 u32 len;
3129
3130 if (!selinux_initialized())
3131 return 0;
3132
3133 rcu_read_lock();
3134 policy = rcu_dereference(selinux_state.policy);
3135 policydb = &policy->policydb;
3136
3137 rc = -EFAULT;
3138 len = policydb->p_bools.nprim;
3139 if (index >= len)
3140 goto out;
3141
3142 rc = policydb->bool_val_to_struct[index]->state;
3143out:
3144 rcu_read_unlock();
3145 return rc;
3146}
3147
3148static int security_preserve_bools(struct selinux_policy *oldpolicy,
3149 struct selinux_policy *newpolicy)
3150{
3151 int rc, *bvalues = NULL;
3152 char **bnames = NULL;
3153 struct cond_bool_datum *booldatum;
3154 u32 i, nbools = 0;
3155
3156 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3157 if (rc)
3158 goto out;
3159 for (i = 0; i < nbools; i++) {
3160 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3161 bnames[i]);
3162 if (booldatum)
3163 booldatum->state = bvalues[i];
3164 }
3165 evaluate_cond_nodes(&newpolicy->policydb);
3166
3167out:
3168 if (bnames) {
3169 for (i = 0; i < nbools; i++)
3170 kfree(bnames[i]);
3171 }
3172 kfree(bnames);
3173 kfree(bvalues);
3174 return rc;
3175}
3176
3177/*
3178 * security_sid_mls_copy() - computes a new sid based on the given
3179 * sid and the mls portion of mls_sid.
3180 */
3181int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
3182{
3183 struct selinux_policy *policy;
3184 struct policydb *policydb;
3185 struct sidtab *sidtab;
3186 struct context *context1;
3187 struct context *context2;
3188 struct context newcon;
3189 char *s;
3190 u32 len;
3191 int rc;
3192
3193 if (!selinux_initialized()) {
3194 *new_sid = sid;
3195 return 0;
3196 }
3197
3198retry:
3199 rc = 0;
3200 context_init(&newcon);
3201
3202 rcu_read_lock();
3203 policy = rcu_dereference(selinux_state.policy);
3204 policydb = &policy->policydb;
3205 sidtab = policy->sidtab;
3206
3207 if (!policydb->mls_enabled) {
3208 *new_sid = sid;
3209 goto out_unlock;
3210 }
3211
3212 rc = -EINVAL;
3213 context1 = sidtab_search(sidtab, sid);
3214 if (!context1) {
3215 pr_err("SELinux: %s: unrecognized SID %d\n",
3216 __func__, sid);
3217 goto out_unlock;
3218 }
3219
3220 rc = -EINVAL;
3221 context2 = sidtab_search(sidtab, mls_sid);
3222 if (!context2) {
3223 pr_err("SELinux: %s: unrecognized SID %d\n",
3224 __func__, mls_sid);
3225 goto out_unlock;
3226 }
3227
3228 newcon.user = context1->user;
3229 newcon.role = context1->role;
3230 newcon.type = context1->type;
3231 rc = mls_context_cpy(&newcon, context2);
3232 if (rc)
3233 goto out_unlock;
3234
3235 /* Check the validity of the new context. */
3236 if (!policydb_context_isvalid(policydb, &newcon)) {
3237 rc = convert_context_handle_invalid_context(policydb,
3238 &newcon);
3239 if (rc) {
3240 if (!context_struct_to_string(policydb, &newcon, &s,
3241 &len)) {
3242 struct audit_buffer *ab;
3243
3244 ab = audit_log_start(audit_context(),
3245 GFP_ATOMIC,
3246 AUDIT_SELINUX_ERR);
3247 audit_log_format(ab,
3248 "op=security_sid_mls_copy invalid_context=");
3249 /* don't record NUL with untrusted strings */
3250 audit_log_n_untrustedstring(ab, s, len - 1);
3251 audit_log_end(ab);
3252 kfree(s);
3253 }
3254 goto out_unlock;
3255 }
3256 }
3257 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3258 if (rc == -ESTALE) {
3259 rcu_read_unlock();
3260 context_destroy(&newcon);
3261 goto retry;
3262 }
3263out_unlock:
3264 rcu_read_unlock();
3265 context_destroy(&newcon);
3266 return rc;
3267}
3268
3269/**
3270 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3271 * @nlbl_sid: NetLabel SID
3272 * @nlbl_type: NetLabel labeling protocol type
3273 * @xfrm_sid: XFRM SID
3274 * @peer_sid: network peer sid
3275 *
3276 * Description:
3277 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3278 * resolved into a single SID it is returned via @peer_sid and the function
3279 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
3280 * returns a negative value. A table summarizing the behavior is below:
3281 *
3282 * | function return | @sid
3283 * ------------------------------+-----------------+-----------------
3284 * no peer labels | 0 | SECSID_NULL
3285 * single peer label | 0 | <peer_label>
3286 * multiple, consistent labels | 0 | <peer_label>
3287 * multiple, inconsistent labels | -<errno> | SECSID_NULL
3288 *
3289 */
3290int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
3291 u32 xfrm_sid,
3292 u32 *peer_sid)
3293{
3294 struct selinux_policy *policy;
3295 struct policydb *policydb;
3296 struct sidtab *sidtab;
3297 int rc;
3298 struct context *nlbl_ctx;
3299 struct context *xfrm_ctx;
3300
3301 *peer_sid = SECSID_NULL;
3302
3303 /* handle the common (which also happens to be the set of easy) cases
3304 * right away, these two if statements catch everything involving a
3305 * single or absent peer SID/label */
3306 if (xfrm_sid == SECSID_NULL) {
3307 *peer_sid = nlbl_sid;
3308 return 0;
3309 }
3310 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3311 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3312 * is present */
3313 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3314 *peer_sid = xfrm_sid;
3315 return 0;
3316 }
3317
3318 if (!selinux_initialized())
3319 return 0;
3320
3321 rcu_read_lock();
3322 policy = rcu_dereference(selinux_state.policy);
3323 policydb = &policy->policydb;
3324 sidtab = policy->sidtab;
3325
3326 /*
3327 * We don't need to check initialized here since the only way both
3328 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3329 * security server was initialized and state->initialized was true.
3330 */
3331 if (!policydb->mls_enabled) {
3332 rc = 0;
3333 goto out;
3334 }
3335
3336 rc = -EINVAL;
3337 nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3338 if (!nlbl_ctx) {
3339 pr_err("SELinux: %s: unrecognized SID %d\n",
3340 __func__, nlbl_sid);
3341 goto out;
3342 }
3343 rc = -EINVAL;
3344 xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3345 if (!xfrm_ctx) {
3346 pr_err("SELinux: %s: unrecognized SID %d\n",
3347 __func__, xfrm_sid);
3348 goto out;
3349 }
3350 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3351 if (rc)
3352 goto out;
3353
3354 /* at present NetLabel SIDs/labels really only carry MLS
3355 * information so if the MLS portion of the NetLabel SID
3356 * matches the MLS portion of the labeled XFRM SID/label
3357 * then pass along the XFRM SID as it is the most
3358 * expressive */
3359 *peer_sid = xfrm_sid;
3360out:
3361 rcu_read_unlock();
3362 return rc;
3363}
3364
3365static int get_classes_callback(void *k, void *d, void *args)
3366{
3367 struct class_datum *datum = d;
3368 char *name = k, **classes = args;
3369 u32 value = datum->value - 1;
3370
3371 classes[value] = kstrdup(name, GFP_ATOMIC);
3372 if (!classes[value])
3373 return -ENOMEM;
3374
3375 return 0;
3376}
3377
3378int security_get_classes(struct selinux_policy *policy,
3379 char ***classes, u32 *nclasses)
3380{
3381 struct policydb *policydb;
3382 int rc;
3383
3384 policydb = &policy->policydb;
3385
3386 rc = -ENOMEM;
3387 *nclasses = policydb->p_classes.nprim;
3388 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3389 if (!*classes)
3390 goto out;
3391
3392 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3393 *classes);
3394 if (rc) {
3395 u32 i;
3396
3397 for (i = 0; i < *nclasses; i++)
3398 kfree((*classes)[i]);
3399 kfree(*classes);
3400 }
3401
3402out:
3403 return rc;
3404}
3405
3406static int get_permissions_callback(void *k, void *d, void *args)
3407{
3408 struct perm_datum *datum = d;
3409 char *name = k, **perms = args;
3410 u32 value = datum->value - 1;
3411
3412 perms[value] = kstrdup(name, GFP_ATOMIC);
3413 if (!perms[value])
3414 return -ENOMEM;
3415
3416 return 0;
3417}
3418
3419int security_get_permissions(struct selinux_policy *policy,
3420 const char *class, char ***perms, u32 *nperms)
3421{
3422 struct policydb *policydb;
3423 u32 i;
3424 int rc;
3425 struct class_datum *match;
3426
3427 policydb = &policy->policydb;
3428
3429 rc = -EINVAL;
3430 match = symtab_search(&policydb->p_classes, class);
3431 if (!match) {
3432 pr_err("SELinux: %s: unrecognized class %s\n",
3433 __func__, class);
3434 goto out;
3435 }
3436
3437 rc = -ENOMEM;
3438 *nperms = match->permissions.nprim;
3439 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3440 if (!*perms)
3441 goto out;
3442
3443 if (match->comdatum) {
3444 rc = hashtab_map(&match->comdatum->permissions.table,
3445 get_permissions_callback, *perms);
3446 if (rc)
3447 goto err;
3448 }
3449
3450 rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3451 *perms);
3452 if (rc)
3453 goto err;
3454
3455out:
3456 return rc;
3457
3458err:
3459 for (i = 0; i < *nperms; i++)
3460 kfree((*perms)[i]);
3461 kfree(*perms);
3462 return rc;
3463}
3464
3465int security_get_reject_unknown(void)
3466{
3467 struct selinux_policy *policy;
3468 int value;
3469
3470 if (!selinux_initialized())
3471 return 0;
3472
3473 rcu_read_lock();
3474 policy = rcu_dereference(selinux_state.policy);
3475 value = policy->policydb.reject_unknown;
3476 rcu_read_unlock();
3477 return value;
3478}
3479
3480int security_get_allow_unknown(void)
3481{
3482 struct selinux_policy *policy;
3483 int value;
3484
3485 if (!selinux_initialized())
3486 return 0;
3487
3488 rcu_read_lock();
3489 policy = rcu_dereference(selinux_state.policy);
3490 value = policy->policydb.allow_unknown;
3491 rcu_read_unlock();
3492 return value;
3493}
3494
3495/**
3496 * security_policycap_supported - Check for a specific policy capability
3497 * @req_cap: capability
3498 *
3499 * Description:
3500 * This function queries the currently loaded policy to see if it supports the
3501 * capability specified by @req_cap. Returns true (1) if the capability is
3502 * supported, false (0) if it isn't supported.
3503 *
3504 */
3505int security_policycap_supported(unsigned int req_cap)
3506{
3507 struct selinux_policy *policy;
3508 int rc;
3509
3510 if (!selinux_initialized())
3511 return 0;
3512
3513 rcu_read_lock();
3514 policy = rcu_dereference(selinux_state.policy);
3515 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3516 rcu_read_unlock();
3517
3518 return rc;
3519}
3520
3521struct selinux_audit_rule {
3522 u32 au_seqno;
3523 struct context au_ctxt;
3524};
3525
3526void selinux_audit_rule_free(void *vrule)
3527{
3528 struct selinux_audit_rule *rule = vrule;
3529
3530 if (rule) {
3531 context_destroy(&rule->au_ctxt);
3532 kfree(rule);
3533 }
3534}
3535
3536int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule,
3537 gfp_t gfp)
3538{
3539 struct selinux_state *state = &selinux_state;
3540 struct selinux_policy *policy;
3541 struct policydb *policydb;
3542 struct selinux_audit_rule *tmprule;
3543 struct role_datum *roledatum;
3544 struct type_datum *typedatum;
3545 struct user_datum *userdatum;
3546 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3547 int rc = 0;
3548
3549 *rule = NULL;
3550
3551 if (!selinux_initialized())
3552 return -EOPNOTSUPP;
3553
3554 switch (field) {
3555 case AUDIT_SUBJ_USER:
3556 case AUDIT_SUBJ_ROLE:
3557 case AUDIT_SUBJ_TYPE:
3558 case AUDIT_OBJ_USER:
3559 case AUDIT_OBJ_ROLE:
3560 case AUDIT_OBJ_TYPE:
3561 /* only 'equals' and 'not equals' fit user, role, and type */
3562 if (op != Audit_equal && op != Audit_not_equal)
3563 return -EINVAL;
3564 break;
3565 case AUDIT_SUBJ_SEN:
3566 case AUDIT_SUBJ_CLR:
3567 case AUDIT_OBJ_LEV_LOW:
3568 case AUDIT_OBJ_LEV_HIGH:
3569 /* we do not allow a range, indicated by the presence of '-' */
3570 if (strchr(rulestr, '-'))
3571 return -EINVAL;
3572 break;
3573 default:
3574 /* only the above fields are valid */
3575 return -EINVAL;
3576 }
3577
3578 tmprule = kzalloc(sizeof(struct selinux_audit_rule), gfp);
3579 if (!tmprule)
3580 return -ENOMEM;
3581 context_init(&tmprule->au_ctxt);
3582
3583 rcu_read_lock();
3584 policy = rcu_dereference(state->policy);
3585 policydb = &policy->policydb;
3586 tmprule->au_seqno = policy->latest_granting;
3587 switch (field) {
3588 case AUDIT_SUBJ_USER:
3589 case AUDIT_OBJ_USER:
3590 userdatum = symtab_search(&policydb->p_users, rulestr);
3591 if (!userdatum) {
3592 rc = -EINVAL;
3593 goto err;
3594 }
3595 tmprule->au_ctxt.user = userdatum->value;
3596 break;
3597 case AUDIT_SUBJ_ROLE:
3598 case AUDIT_OBJ_ROLE:
3599 roledatum = symtab_search(&policydb->p_roles, rulestr);
3600 if (!roledatum) {
3601 rc = -EINVAL;
3602 goto err;
3603 }
3604 tmprule->au_ctxt.role = roledatum->value;
3605 break;
3606 case AUDIT_SUBJ_TYPE:
3607 case AUDIT_OBJ_TYPE:
3608 typedatum = symtab_search(&policydb->p_types, rulestr);
3609 if (!typedatum) {
3610 rc = -EINVAL;
3611 goto err;
3612 }
3613 tmprule->au_ctxt.type = typedatum->value;
3614 break;
3615 case AUDIT_SUBJ_SEN:
3616 case AUDIT_SUBJ_CLR:
3617 case AUDIT_OBJ_LEV_LOW:
3618 case AUDIT_OBJ_LEV_HIGH:
3619 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3620 GFP_ATOMIC);
3621 if (rc)
3622 goto err;
3623 break;
3624 }
3625 rcu_read_unlock();
3626
3627 *rule = tmprule;
3628 return 0;
3629
3630err:
3631 rcu_read_unlock();
3632 selinux_audit_rule_free(tmprule);
3633 *rule = NULL;
3634 return rc;
3635}
3636
3637/* Check to see if the rule contains any selinux fields */
3638int selinux_audit_rule_known(struct audit_krule *rule)
3639{
3640 u32 i;
3641
3642 for (i = 0; i < rule->field_count; i++) {
3643 struct audit_field *f = &rule->fields[i];
3644 switch (f->type) {
3645 case AUDIT_SUBJ_USER:
3646 case AUDIT_SUBJ_ROLE:
3647 case AUDIT_SUBJ_TYPE:
3648 case AUDIT_SUBJ_SEN:
3649 case AUDIT_SUBJ_CLR:
3650 case AUDIT_OBJ_USER:
3651 case AUDIT_OBJ_ROLE:
3652 case AUDIT_OBJ_TYPE:
3653 case AUDIT_OBJ_LEV_LOW:
3654 case AUDIT_OBJ_LEV_HIGH:
3655 return 1;
3656 }
3657 }
3658
3659 return 0;
3660}
3661
3662int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule)
3663{
3664 struct selinux_state *state = &selinux_state;
3665 struct selinux_policy *policy;
3666 struct context *ctxt;
3667 struct mls_level *level;
3668 struct selinux_audit_rule *rule = vrule;
3669 int match = 0;
3670
3671 if (unlikely(!rule)) {
3672 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3673 return -ENOENT;
3674 }
3675
3676 if (!selinux_initialized())
3677 return 0;
3678
3679 rcu_read_lock();
3680
3681 policy = rcu_dereference(state->policy);
3682
3683 if (rule->au_seqno < policy->latest_granting) {
3684 match = -ESTALE;
3685 goto out;
3686 }
3687
3688 ctxt = sidtab_search(policy->sidtab, prop->selinux.secid);
3689 if (unlikely(!ctxt)) {
3690 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3691 prop->selinux.secid);
3692 match = -ENOENT;
3693 goto out;
3694 }
3695
3696 /* a field/op pair that is not caught here will simply fall through
3697 without a match */
3698 switch (field) {
3699 case AUDIT_SUBJ_USER:
3700 case AUDIT_OBJ_USER:
3701 switch (op) {
3702 case Audit_equal:
3703 match = (ctxt->user == rule->au_ctxt.user);
3704 break;
3705 case Audit_not_equal:
3706 match = (ctxt->user != rule->au_ctxt.user);
3707 break;
3708 }
3709 break;
3710 case AUDIT_SUBJ_ROLE:
3711 case AUDIT_OBJ_ROLE:
3712 switch (op) {
3713 case Audit_equal:
3714 match = (ctxt->role == rule->au_ctxt.role);
3715 break;
3716 case Audit_not_equal:
3717 match = (ctxt->role != rule->au_ctxt.role);
3718 break;
3719 }
3720 break;
3721 case AUDIT_SUBJ_TYPE:
3722 case AUDIT_OBJ_TYPE:
3723 switch (op) {
3724 case Audit_equal:
3725 match = (ctxt->type == rule->au_ctxt.type);
3726 break;
3727 case Audit_not_equal:
3728 match = (ctxt->type != rule->au_ctxt.type);
3729 break;
3730 }
3731 break;
3732 case AUDIT_SUBJ_SEN:
3733 case AUDIT_SUBJ_CLR:
3734 case AUDIT_OBJ_LEV_LOW:
3735 case AUDIT_OBJ_LEV_HIGH:
3736 level = ((field == AUDIT_SUBJ_SEN ||
3737 field == AUDIT_OBJ_LEV_LOW) ?
3738 &ctxt->range.level[0] : &ctxt->range.level[1]);
3739 switch (op) {
3740 case Audit_equal:
3741 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3742 level);
3743 break;
3744 case Audit_not_equal:
3745 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3746 level);
3747 break;
3748 case Audit_lt:
3749 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3750 level) &&
3751 !mls_level_eq(&rule->au_ctxt.range.level[0],
3752 level));
3753 break;
3754 case Audit_le:
3755 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3756 level);
3757 break;
3758 case Audit_gt:
3759 match = (mls_level_dom(level,
3760 &rule->au_ctxt.range.level[0]) &&
3761 !mls_level_eq(level,
3762 &rule->au_ctxt.range.level[0]));
3763 break;
3764 case Audit_ge:
3765 match = mls_level_dom(level,
3766 &rule->au_ctxt.range.level[0]);
3767 break;
3768 }
3769 }
3770
3771out:
3772 rcu_read_unlock();
3773 return match;
3774}
3775
3776static int aurule_avc_callback(u32 event)
3777{
3778 if (event == AVC_CALLBACK_RESET)
3779 return audit_update_lsm_rules();
3780 return 0;
3781}
3782
3783static int __init aurule_init(void)
3784{
3785 int err;
3786
3787 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3788 if (err)
3789 panic("avc_add_callback() failed, error %d\n", err);
3790
3791 return err;
3792}
3793__initcall(aurule_init);
3794
3795#ifdef CONFIG_NETLABEL
3796/**
3797 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3798 * @secattr: the NetLabel packet security attributes
3799 * @sid: the SELinux SID
3800 *
3801 * Description:
3802 * Attempt to cache the context in @ctx, which was derived from the packet in
3803 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3804 * already been initialized.
3805 *
3806 */
3807static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3808 u32 sid)
3809{
3810 u32 *sid_cache;
3811
3812 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3813 if (sid_cache == NULL)
3814 return;
3815 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3816 if (secattr->cache == NULL) {
3817 kfree(sid_cache);
3818 return;
3819 }
3820
3821 *sid_cache = sid;
3822 secattr->cache->free = kfree;
3823 secattr->cache->data = sid_cache;
3824 secattr->flags |= NETLBL_SECATTR_CACHE;
3825}
3826
3827/**
3828 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3829 * @secattr: the NetLabel packet security attributes
3830 * @sid: the SELinux SID
3831 *
3832 * Description:
3833 * Convert the given NetLabel security attributes in @secattr into a
3834 * SELinux SID. If the @secattr field does not contain a full SELinux
3835 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3836 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3837 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3838 * conversion for future lookups. Returns zero on success, negative values on
3839 * failure.
3840 *
3841 */
3842int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3843 u32 *sid)
3844{
3845 struct selinux_policy *policy;
3846 struct policydb *policydb;
3847 struct sidtab *sidtab;
3848 int rc;
3849 struct context *ctx;
3850 struct context ctx_new;
3851
3852 if (!selinux_initialized()) {
3853 *sid = SECSID_NULL;
3854 return 0;
3855 }
3856
3857retry:
3858 rc = 0;
3859 rcu_read_lock();
3860 policy = rcu_dereference(selinux_state.policy);
3861 policydb = &policy->policydb;
3862 sidtab = policy->sidtab;
3863
3864 if (secattr->flags & NETLBL_SECATTR_CACHE)
3865 *sid = *(u32 *)secattr->cache->data;
3866 else if (secattr->flags & NETLBL_SECATTR_SECID)
3867 *sid = secattr->attr.secid;
3868 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3869 rc = -EIDRM;
3870 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3871 if (ctx == NULL)
3872 goto out;
3873
3874 context_init(&ctx_new);
3875 ctx_new.user = ctx->user;
3876 ctx_new.role = ctx->role;
3877 ctx_new.type = ctx->type;
3878 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3879 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3880 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3881 if (rc)
3882 goto out;
3883 }
3884 rc = -EIDRM;
3885 if (!mls_context_isvalid(policydb, &ctx_new)) {
3886 ebitmap_destroy(&ctx_new.range.level[0].cat);
3887 goto out;
3888 }
3889
3890 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3891 ebitmap_destroy(&ctx_new.range.level[0].cat);
3892 if (rc == -ESTALE) {
3893 rcu_read_unlock();
3894 goto retry;
3895 }
3896 if (rc)
3897 goto out;
3898
3899 security_netlbl_cache_add(secattr, *sid);
3900 } else
3901 *sid = SECSID_NULL;
3902
3903out:
3904 rcu_read_unlock();
3905 return rc;
3906}
3907
3908/**
3909 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3910 * @sid: the SELinux SID
3911 * @secattr: the NetLabel packet security attributes
3912 *
3913 * Description:
3914 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3915 * Returns zero on success, negative values on failure.
3916 *
3917 */
3918int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3919{
3920 struct selinux_policy *policy;
3921 struct policydb *policydb;
3922 int rc;
3923 struct context *ctx;
3924
3925 if (!selinux_initialized())
3926 return 0;
3927
3928 rcu_read_lock();
3929 policy = rcu_dereference(selinux_state.policy);
3930 policydb = &policy->policydb;
3931
3932 rc = -ENOENT;
3933 ctx = sidtab_search(policy->sidtab, sid);
3934 if (ctx == NULL)
3935 goto out;
3936
3937 rc = -ENOMEM;
3938 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3939 GFP_ATOMIC);
3940 if (secattr->domain == NULL)
3941 goto out;
3942
3943 secattr->attr.secid = sid;
3944 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3945 mls_export_netlbl_lvl(policydb, ctx, secattr);
3946 rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3947out:
3948 rcu_read_unlock();
3949 return rc;
3950}
3951#endif /* CONFIG_NETLABEL */
3952
3953/**
3954 * __security_read_policy - read the policy.
3955 * @policy: SELinux policy
3956 * @data: binary policy data
3957 * @len: length of data in bytes
3958 *
3959 */
3960static int __security_read_policy(struct selinux_policy *policy,
3961 void *data, size_t *len)
3962{
3963 int rc;
3964 struct policy_file fp;
3965
3966 fp.data = data;
3967 fp.len = *len;
3968
3969 rc = policydb_write(&policy->policydb, &fp);
3970 if (rc)
3971 return rc;
3972
3973 *len = (unsigned long)fp.data - (unsigned long)data;
3974 return 0;
3975}
3976
3977/**
3978 * security_read_policy - read the policy.
3979 * @data: binary policy data
3980 * @len: length of data in bytes
3981 *
3982 */
3983int security_read_policy(void **data, size_t *len)
3984{
3985 struct selinux_state *state = &selinux_state;
3986 struct selinux_policy *policy;
3987
3988 policy = rcu_dereference_protected(
3989 state->policy, lockdep_is_held(&state->policy_mutex));
3990 if (!policy)
3991 return -EINVAL;
3992
3993 *len = policy->policydb.len;
3994 *data = vmalloc_user(*len);
3995 if (!*data)
3996 return -ENOMEM;
3997
3998 return __security_read_policy(policy, *data, len);
3999}
4000
4001/**
4002 * security_read_state_kernel - read the policy.
4003 * @data: binary policy data
4004 * @len: length of data in bytes
4005 *
4006 * Allocates kernel memory for reading SELinux policy.
4007 * This function is for internal use only and should not
4008 * be used for returning data to user space.
4009 *
4010 * This function must be called with policy_mutex held.
4011 */
4012int security_read_state_kernel(void **data, size_t *len)
4013{
4014 int err;
4015 struct selinux_state *state = &selinux_state;
4016 struct selinux_policy *policy;
4017
4018 policy = rcu_dereference_protected(
4019 state->policy, lockdep_is_held(&state->policy_mutex));
4020 if (!policy)
4021 return -EINVAL;
4022
4023 *len = policy->policydb.len;
4024 *data = vmalloc(*len);
4025 if (!*data)
4026 return -ENOMEM;
4027
4028 err = __security_read_policy(policy, *data, len);
4029 if (err) {
4030 vfree(*data);
4031 *data = NULL;
4032 *len = 0;
4033 }
4034 return err;
4035}