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