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selinux: ensure the context is NUL terminated in security_context_to_sid_core()
[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 read_lock(&policy_rwlock);
871
872 rc = -EINVAL;
873 old_context = sidtab_search(&sidtab, old_sid);
874 if (!old_context) {
875 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
876 __func__, old_sid);
877 goto out;
878 }
879
880 rc = -EINVAL;
881 new_context = sidtab_search(&sidtab, new_sid);
882 if (!new_context) {
883 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
884 __func__, new_sid);
885 goto out;
886 }
887
888 rc = 0;
889 /* type/domain unchanged */
890 if (old_context->type == new_context->type)
891 goto out;
892
893 index = new_context->type;
894 while (true) {
895 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
896 index - 1);
897 BUG_ON(!type);
898
899 /* not bounded anymore */
900 rc = -EPERM;
901 if (!type->bounds)
902 break;
903
904 /* @newsid is bounded by @oldsid */
905 rc = 0;
906 if (type->bounds == old_context->type)
907 break;
908
909 index = type->bounds;
910 }
911
912 if (rc) {
913 char *old_name = NULL;
914 char *new_name = NULL;
915 u32 length;
916
917 if (!context_struct_to_string(old_context,
918 &old_name, &length) &&
919 !context_struct_to_string(new_context,
920 &new_name, &length)) {
921 audit_log(current->audit_context,
922 GFP_ATOMIC, AUDIT_SELINUX_ERR,
923 "op=security_bounded_transition "
924 "seresult=denied "
925 "oldcontext=%s newcontext=%s",
926 old_name, new_name);
927 }
928 kfree(new_name);
929 kfree(old_name);
930 }
931 out:
932 read_unlock(&policy_rwlock);
933
934 return rc;
935 }
936
937 static void avd_init(struct av_decision *avd)
938 {
939 avd->allowed = 0;
940 avd->auditallow = 0;
941 avd->auditdeny = 0xffffffff;
942 avd->seqno = latest_granting;
943 avd->flags = 0;
944 }
945
946 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
947 struct avtab_node *node)
948 {
949 unsigned int i;
950
951 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
952 if (xpermd->driver != node->datum.u.xperms->driver)
953 return;
954 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
955 if (!security_xperm_test(node->datum.u.xperms->perms.p,
956 xpermd->driver))
957 return;
958 } else {
959 BUG();
960 }
961
962 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
963 xpermd->used |= XPERMS_ALLOWED;
964 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
965 memset(xpermd->allowed->p, 0xff,
966 sizeof(xpermd->allowed->p));
967 }
968 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
969 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
970 xpermd->allowed->p[i] |=
971 node->datum.u.xperms->perms.p[i];
972 }
973 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
974 xpermd->used |= XPERMS_AUDITALLOW;
975 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
976 memset(xpermd->auditallow->p, 0xff,
977 sizeof(xpermd->auditallow->p));
978 }
979 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
980 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
981 xpermd->auditallow->p[i] |=
982 node->datum.u.xperms->perms.p[i];
983 }
984 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
985 xpermd->used |= XPERMS_DONTAUDIT;
986 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
987 memset(xpermd->dontaudit->p, 0xff,
988 sizeof(xpermd->dontaudit->p));
989 }
990 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
991 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
992 xpermd->dontaudit->p[i] |=
993 node->datum.u.xperms->perms.p[i];
994 }
995 } else {
996 BUG();
997 }
998 }
999
1000 void security_compute_xperms_decision(u32 ssid,
1001 u32 tsid,
1002 u16 orig_tclass,
1003 u8 driver,
1004 struct extended_perms_decision *xpermd)
1005 {
1006 u16 tclass;
1007 struct context *scontext, *tcontext;
1008 struct avtab_key avkey;
1009 struct avtab_node *node;
1010 struct ebitmap *sattr, *tattr;
1011 struct ebitmap_node *snode, *tnode;
1012 unsigned int i, j;
1013
1014 xpermd->driver = driver;
1015 xpermd->used = 0;
1016 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1017 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1018 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1019
1020 read_lock(&policy_rwlock);
1021 if (!ss_initialized)
1022 goto allow;
1023
1024 scontext = sidtab_search(&sidtab, ssid);
1025 if (!scontext) {
1026 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1027 __func__, ssid);
1028 goto out;
1029 }
1030
1031 tcontext = sidtab_search(&sidtab, tsid);
1032 if (!tcontext) {
1033 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1034 __func__, tsid);
1035 goto out;
1036 }
1037
1038 tclass = unmap_class(orig_tclass);
1039 if (unlikely(orig_tclass && !tclass)) {
1040 if (policydb.allow_unknown)
1041 goto allow;
1042 goto out;
1043 }
1044
1045
1046 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1047 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1048 goto out;
1049 }
1050
1051 avkey.target_class = tclass;
1052 avkey.specified = AVTAB_XPERMS;
1053 sattr = flex_array_get(policydb.type_attr_map_array,
1054 scontext->type - 1);
1055 BUG_ON(!sattr);
1056 tattr = flex_array_get(policydb.type_attr_map_array,
1057 tcontext->type - 1);
1058 BUG_ON(!tattr);
1059 ebitmap_for_each_positive_bit(sattr, snode, i) {
1060 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1061 avkey.source_type = i + 1;
1062 avkey.target_type = j + 1;
1063 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1064 node;
1065 node = avtab_search_node_next(node, avkey.specified))
1066 services_compute_xperms_decision(xpermd, node);
1067
1068 cond_compute_xperms(&policydb.te_cond_avtab,
1069 &avkey, xpermd);
1070 }
1071 }
1072 out:
1073 read_unlock(&policy_rwlock);
1074 return;
1075 allow:
1076 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1077 goto out;
1078 }
1079
1080 /**
1081 * security_compute_av - Compute access vector decisions.
1082 * @ssid: source security identifier
1083 * @tsid: target security identifier
1084 * @tclass: target security class
1085 * @avd: access vector decisions
1086 * @xperms: extended permissions
1087 *
1088 * Compute a set of access vector decisions based on the
1089 * SID pair (@ssid, @tsid) for the permissions in @tclass.
1090 */
1091 void security_compute_av(u32 ssid,
1092 u32 tsid,
1093 u16 orig_tclass,
1094 struct av_decision *avd,
1095 struct extended_perms *xperms)
1096 {
1097 u16 tclass;
1098 struct context *scontext = NULL, *tcontext = NULL;
1099
1100 read_lock(&policy_rwlock);
1101 avd_init(avd);
1102 xperms->len = 0;
1103 if (!ss_initialized)
1104 goto allow;
1105
1106 scontext = sidtab_search(&sidtab, ssid);
1107 if (!scontext) {
1108 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1109 __func__, ssid);
1110 goto out;
1111 }
1112
1113 /* permissive domain? */
1114 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1115 avd->flags |= AVD_FLAGS_PERMISSIVE;
1116
1117 tcontext = sidtab_search(&sidtab, tsid);
1118 if (!tcontext) {
1119 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1120 __func__, tsid);
1121 goto out;
1122 }
1123
1124 tclass = unmap_class(orig_tclass);
1125 if (unlikely(orig_tclass && !tclass)) {
1126 if (policydb.allow_unknown)
1127 goto allow;
1128 goto out;
1129 }
1130 context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1131 map_decision(orig_tclass, avd, policydb.allow_unknown);
1132 out:
1133 read_unlock(&policy_rwlock);
1134 return;
1135 allow:
1136 avd->allowed = 0xffffffff;
1137 goto out;
1138 }
1139
1140 void security_compute_av_user(u32 ssid,
1141 u32 tsid,
1142 u16 tclass,
1143 struct av_decision *avd)
1144 {
1145 struct context *scontext = NULL, *tcontext = NULL;
1146
1147 read_lock(&policy_rwlock);
1148 avd_init(avd);
1149 if (!ss_initialized)
1150 goto allow;
1151
1152 scontext = sidtab_search(&sidtab, ssid);
1153 if (!scontext) {
1154 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1155 __func__, ssid);
1156 goto out;
1157 }
1158
1159 /* permissive domain? */
1160 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1161 avd->flags |= AVD_FLAGS_PERMISSIVE;
1162
1163 tcontext = sidtab_search(&sidtab, tsid);
1164 if (!tcontext) {
1165 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1166 __func__, tsid);
1167 goto out;
1168 }
1169
1170 if (unlikely(!tclass)) {
1171 if (policydb.allow_unknown)
1172 goto allow;
1173 goto out;
1174 }
1175
1176 context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1177 out:
1178 read_unlock(&policy_rwlock);
1179 return;
1180 allow:
1181 avd->allowed = 0xffffffff;
1182 goto out;
1183 }
1184
1185 /*
1186 * Write the security context string representation of
1187 * the context structure `context' into a dynamically
1188 * allocated string of the correct size. Set `*scontext'
1189 * to point to this string and set `*scontext_len' to
1190 * the length of the string.
1191 */
1192 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1193 {
1194 char *scontextp;
1195
1196 if (scontext)
1197 *scontext = NULL;
1198 *scontext_len = 0;
1199
1200 if (context->len) {
1201 *scontext_len = context->len;
1202 if (scontext) {
1203 *scontext = kstrdup(context->str, GFP_ATOMIC);
1204 if (!(*scontext))
1205 return -ENOMEM;
1206 }
1207 return 0;
1208 }
1209
1210 /* Compute the size of the context. */
1211 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1212 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1213 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1214 *scontext_len += mls_compute_context_len(context);
1215
1216 if (!scontext)
1217 return 0;
1218
1219 /* Allocate space for the context; caller must free this space. */
1220 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1221 if (!scontextp)
1222 return -ENOMEM;
1223 *scontext = scontextp;
1224
1225 /*
1226 * Copy the user name, role name and type name into the context.
1227 */
1228 scontextp += sprintf(scontextp, "%s:%s:%s",
1229 sym_name(&policydb, SYM_USERS, context->user - 1),
1230 sym_name(&policydb, SYM_ROLES, context->role - 1),
1231 sym_name(&policydb, SYM_TYPES, context->type - 1));
1232
1233 mls_sid_to_context(context, &scontextp);
1234
1235 *scontextp = 0;
1236
1237 return 0;
1238 }
1239
1240 #include "initial_sid_to_string.h"
1241
1242 const char *security_get_initial_sid_context(u32 sid)
1243 {
1244 if (unlikely(sid > SECINITSID_NUM))
1245 return NULL;
1246 return initial_sid_to_string[sid];
1247 }
1248
1249 static int security_sid_to_context_core(u32 sid, char **scontext,
1250 u32 *scontext_len, int force)
1251 {
1252 struct context *context;
1253 int rc = 0;
1254
1255 if (scontext)
1256 *scontext = NULL;
1257 *scontext_len = 0;
1258
1259 if (!ss_initialized) {
1260 if (sid <= SECINITSID_NUM) {
1261 char *scontextp;
1262
1263 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1264 if (!scontext)
1265 goto out;
1266 scontextp = kmemdup(initial_sid_to_string[sid],
1267 *scontext_len, GFP_ATOMIC);
1268 if (!scontextp) {
1269 rc = -ENOMEM;
1270 goto out;
1271 }
1272 *scontext = scontextp;
1273 goto out;
1274 }
1275 printk(KERN_ERR "SELinux: %s: called before initial "
1276 "load_policy on unknown SID %d\n", __func__, sid);
1277 rc = -EINVAL;
1278 goto out;
1279 }
1280 read_lock(&policy_rwlock);
1281 if (force)
1282 context = sidtab_search_force(&sidtab, sid);
1283 else
1284 context = sidtab_search(&sidtab, sid);
1285 if (!context) {
1286 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1287 __func__, sid);
1288 rc = -EINVAL;
1289 goto out_unlock;
1290 }
1291 rc = context_struct_to_string(context, scontext, scontext_len);
1292 out_unlock:
1293 read_unlock(&policy_rwlock);
1294 out:
1295 return rc;
1296
1297 }
1298
1299 /**
1300 * security_sid_to_context - Obtain a context for a given SID.
1301 * @sid: security identifier, SID
1302 * @scontext: security context
1303 * @scontext_len: length in bytes
1304 *
1305 * Write the string representation of the context associated with @sid
1306 * into a dynamically allocated string of the correct size. Set @scontext
1307 * to point to this string and set @scontext_len to the length of the string.
1308 */
1309 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1310 {
1311 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1312 }
1313
1314 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1315 {
1316 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1317 }
1318
1319 /*
1320 * Caveat: Mutates scontext.
1321 */
1322 static int string_to_context_struct(struct policydb *pol,
1323 struct sidtab *sidtabp,
1324 char *scontext,
1325 u32 scontext_len,
1326 struct context *ctx,
1327 u32 def_sid)
1328 {
1329 struct role_datum *role;
1330 struct type_datum *typdatum;
1331 struct user_datum *usrdatum;
1332 char *scontextp, *p, oldc;
1333 int rc = 0;
1334
1335 context_init(ctx);
1336
1337 /* Parse the security context. */
1338
1339 rc = -EINVAL;
1340 scontextp = (char *) scontext;
1341
1342 /* Extract the user. */
1343 p = scontextp;
1344 while (*p && *p != ':')
1345 p++;
1346
1347 if (*p == 0)
1348 goto out;
1349
1350 *p++ = 0;
1351
1352 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1353 if (!usrdatum)
1354 goto out;
1355
1356 ctx->user = usrdatum->value;
1357
1358 /* Extract role. */
1359 scontextp = p;
1360 while (*p && *p != ':')
1361 p++;
1362
1363 if (*p == 0)
1364 goto out;
1365
1366 *p++ = 0;
1367
1368 role = hashtab_search(pol->p_roles.table, scontextp);
1369 if (!role)
1370 goto out;
1371 ctx->role = role->value;
1372
1373 /* Extract type. */
1374 scontextp = p;
1375 while (*p && *p != ':')
1376 p++;
1377 oldc = *p;
1378 *p++ = 0;
1379
1380 typdatum = hashtab_search(pol->p_types.table, scontextp);
1381 if (!typdatum || typdatum->attribute)
1382 goto out;
1383
1384 ctx->type = typdatum->value;
1385
1386 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1387 if (rc)
1388 goto out;
1389
1390 rc = -EINVAL;
1391 if ((p - scontext) < scontext_len)
1392 goto out;
1393
1394 /* Check the validity of the new context. */
1395 if (!policydb_context_isvalid(pol, ctx))
1396 goto out;
1397 rc = 0;
1398 out:
1399 if (rc)
1400 context_destroy(ctx);
1401 return rc;
1402 }
1403
1404 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1405 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1406 int force)
1407 {
1408 char *scontext2, *str = NULL;
1409 struct context context;
1410 int rc = 0;
1411
1412 /* An empty security context is never valid. */
1413 if (!scontext_len)
1414 return -EINVAL;
1415
1416 /* Copy the string to allow changes and ensure a NUL terminator */
1417 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1418 if (!scontext2)
1419 return -ENOMEM;
1420
1421 if (!ss_initialized) {
1422 int i;
1423
1424 for (i = 1; i < SECINITSID_NUM; i++) {
1425 if (!strcmp(initial_sid_to_string[i], scontext2)) {
1426 *sid = i;
1427 goto out;
1428 }
1429 }
1430 *sid = SECINITSID_KERNEL;
1431 goto out;
1432 }
1433 *sid = SECSID_NULL;
1434
1435 if (force) {
1436 /* Save another copy for storing in uninterpreted form */
1437 rc = -ENOMEM;
1438 str = kstrdup(scontext2, gfp_flags);
1439 if (!str)
1440 goto out;
1441 }
1442
1443 read_lock(&policy_rwlock);
1444 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1445 scontext_len, &context, def_sid);
1446 if (rc == -EINVAL && force) {
1447 context.str = str;
1448 context.len = scontext_len;
1449 str = NULL;
1450 } else if (rc)
1451 goto out_unlock;
1452 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1453 context_destroy(&context);
1454 out_unlock:
1455 read_unlock(&policy_rwlock);
1456 out:
1457 kfree(scontext2);
1458 kfree(str);
1459 return rc;
1460 }
1461
1462 /**
1463 * security_context_to_sid - Obtain a SID for a given security context.
1464 * @scontext: security context
1465 * @scontext_len: length in bytes
1466 * @sid: security identifier, SID
1467 * @gfp: context for the allocation
1468 *
1469 * Obtains a SID associated with the security context that
1470 * has the string representation specified by @scontext.
1471 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1472 * memory is available, or 0 on success.
1473 */
1474 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1475 gfp_t gfp)
1476 {
1477 return security_context_to_sid_core(scontext, scontext_len,
1478 sid, SECSID_NULL, gfp, 0);
1479 }
1480
1481 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1482 {
1483 return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1484 }
1485
1486 /**
1487 * security_context_to_sid_default - Obtain a SID for a given security context,
1488 * falling back to specified default if needed.
1489 *
1490 * @scontext: security context
1491 * @scontext_len: length in bytes
1492 * @sid: security identifier, SID
1493 * @def_sid: default SID to assign on error
1494 *
1495 * Obtains a SID associated with the security context that
1496 * has the string representation specified by @scontext.
1497 * The default SID is passed to the MLS layer to be used to allow
1498 * kernel labeling of the MLS field if the MLS field is not present
1499 * (for upgrading to MLS without full relabel).
1500 * Implicitly forces adding of the context even if it cannot be mapped yet.
1501 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1502 * memory is available, or 0 on success.
1503 */
1504 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1505 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1506 {
1507 return security_context_to_sid_core(scontext, scontext_len,
1508 sid, def_sid, gfp_flags, 1);
1509 }
1510
1511 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1512 u32 *sid)
1513 {
1514 return security_context_to_sid_core(scontext, scontext_len,
1515 sid, SECSID_NULL, GFP_KERNEL, 1);
1516 }
1517
1518 static int compute_sid_handle_invalid_context(
1519 struct context *scontext,
1520 struct context *tcontext,
1521 u16 tclass,
1522 struct context *newcontext)
1523 {
1524 char *s = NULL, *t = NULL, *n = NULL;
1525 u32 slen, tlen, nlen;
1526
1527 if (context_struct_to_string(scontext, &s, &slen))
1528 goto out;
1529 if (context_struct_to_string(tcontext, &t, &tlen))
1530 goto out;
1531 if (context_struct_to_string(newcontext, &n, &nlen))
1532 goto out;
1533 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1534 "op=security_compute_sid invalid_context=%s"
1535 " scontext=%s"
1536 " tcontext=%s"
1537 " tclass=%s",
1538 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1539 out:
1540 kfree(s);
1541 kfree(t);
1542 kfree(n);
1543 if (!selinux_enforcing)
1544 return 0;
1545 return -EACCES;
1546 }
1547
1548 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1549 u32 stype, u32 ttype, u16 tclass,
1550 const char *objname)
1551 {
1552 struct filename_trans ft;
1553 struct filename_trans_datum *otype;
1554
1555 /*
1556 * Most filename trans rules are going to live in specific directories
1557 * like /dev or /var/run. This bitmap will quickly skip rule searches
1558 * if the ttype does not contain any rules.
1559 */
1560 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1561 return;
1562
1563 ft.stype = stype;
1564 ft.ttype = ttype;
1565 ft.tclass = tclass;
1566 ft.name = objname;
1567
1568 otype = hashtab_search(p->filename_trans, &ft);
1569 if (otype)
1570 newcontext->type = otype->otype;
1571 }
1572
1573 static int security_compute_sid(u32 ssid,
1574 u32 tsid,
1575 u16 orig_tclass,
1576 u32 specified,
1577 const char *objname,
1578 u32 *out_sid,
1579 bool kern)
1580 {
1581 struct class_datum *cladatum = NULL;
1582 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1583 struct role_trans *roletr = NULL;
1584 struct avtab_key avkey;
1585 struct avtab_datum *avdatum;
1586 struct avtab_node *node;
1587 u16 tclass;
1588 int rc = 0;
1589 bool sock;
1590
1591 if (!ss_initialized) {
1592 switch (orig_tclass) {
1593 case SECCLASS_PROCESS: /* kernel value */
1594 *out_sid = ssid;
1595 break;
1596 default:
1597 *out_sid = tsid;
1598 break;
1599 }
1600 goto out;
1601 }
1602
1603 context_init(&newcontext);
1604
1605 read_lock(&policy_rwlock);
1606
1607 if (kern) {
1608 tclass = unmap_class(orig_tclass);
1609 sock = security_is_socket_class(orig_tclass);
1610 } else {
1611 tclass = orig_tclass;
1612 sock = security_is_socket_class(map_class(tclass));
1613 }
1614
1615 scontext = sidtab_search(&sidtab, ssid);
1616 if (!scontext) {
1617 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1618 __func__, ssid);
1619 rc = -EINVAL;
1620 goto out_unlock;
1621 }
1622 tcontext = sidtab_search(&sidtab, tsid);
1623 if (!tcontext) {
1624 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1625 __func__, tsid);
1626 rc = -EINVAL;
1627 goto out_unlock;
1628 }
1629
1630 if (tclass && tclass <= policydb.p_classes.nprim)
1631 cladatum = policydb.class_val_to_struct[tclass - 1];
1632
1633 /* Set the user identity. */
1634 switch (specified) {
1635 case AVTAB_TRANSITION:
1636 case AVTAB_CHANGE:
1637 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1638 newcontext.user = tcontext->user;
1639 } else {
1640 /* notice this gets both DEFAULT_SOURCE and unset */
1641 /* Use the process user identity. */
1642 newcontext.user = scontext->user;
1643 }
1644 break;
1645 case AVTAB_MEMBER:
1646 /* Use the related object owner. */
1647 newcontext.user = tcontext->user;
1648 break;
1649 }
1650
1651 /* Set the role to default values. */
1652 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1653 newcontext.role = scontext->role;
1654 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1655 newcontext.role = tcontext->role;
1656 } else {
1657 if ((tclass == policydb.process_class) || (sock == true))
1658 newcontext.role = scontext->role;
1659 else
1660 newcontext.role = OBJECT_R_VAL;
1661 }
1662
1663 /* Set the type to default values. */
1664 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1665 newcontext.type = scontext->type;
1666 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1667 newcontext.type = tcontext->type;
1668 } else {
1669 if ((tclass == policydb.process_class) || (sock == true)) {
1670 /* Use the type of process. */
1671 newcontext.type = scontext->type;
1672 } else {
1673 /* Use the type of the related object. */
1674 newcontext.type = tcontext->type;
1675 }
1676 }
1677
1678 /* Look for a type transition/member/change rule. */
1679 avkey.source_type = scontext->type;
1680 avkey.target_type = tcontext->type;
1681 avkey.target_class = tclass;
1682 avkey.specified = specified;
1683 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1684
1685 /* If no permanent rule, also check for enabled conditional rules */
1686 if (!avdatum) {
1687 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1688 for (; node; node = avtab_search_node_next(node, specified)) {
1689 if (node->key.specified & AVTAB_ENABLED) {
1690 avdatum = &node->datum;
1691 break;
1692 }
1693 }
1694 }
1695
1696 if (avdatum) {
1697 /* Use the type from the type transition/member/change rule. */
1698 newcontext.type = avdatum->u.data;
1699 }
1700
1701 /* if we have a objname this is a file trans check so check those rules */
1702 if (objname)
1703 filename_compute_type(&policydb, &newcontext, scontext->type,
1704 tcontext->type, tclass, objname);
1705
1706 /* Check for class-specific changes. */
1707 if (specified & AVTAB_TRANSITION) {
1708 /* Look for a role transition rule. */
1709 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1710 if ((roletr->role == scontext->role) &&
1711 (roletr->type == tcontext->type) &&
1712 (roletr->tclass == tclass)) {
1713 /* Use the role transition rule. */
1714 newcontext.role = roletr->new_role;
1715 break;
1716 }
1717 }
1718 }
1719
1720 /* Set the MLS attributes.
1721 This is done last because it may allocate memory. */
1722 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1723 &newcontext, sock);
1724 if (rc)
1725 goto out_unlock;
1726
1727 /* Check the validity of the context. */
1728 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1729 rc = compute_sid_handle_invalid_context(scontext,
1730 tcontext,
1731 tclass,
1732 &newcontext);
1733 if (rc)
1734 goto out_unlock;
1735 }
1736 /* Obtain the sid for the context. */
1737 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1738 out_unlock:
1739 read_unlock(&policy_rwlock);
1740 context_destroy(&newcontext);
1741 out:
1742 return rc;
1743 }
1744
1745 /**
1746 * security_transition_sid - Compute the SID for a new subject/object.
1747 * @ssid: source security identifier
1748 * @tsid: target security identifier
1749 * @tclass: target security class
1750 * @out_sid: security identifier for new subject/object
1751 *
1752 * Compute a SID to use for labeling a new subject or object in the
1753 * class @tclass based on a SID pair (@ssid, @tsid).
1754 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1755 * if insufficient memory is available, or %0 if the new SID was
1756 * computed successfully.
1757 */
1758 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1759 const struct qstr *qstr, u32 *out_sid)
1760 {
1761 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1762 qstr ? qstr->name : NULL, out_sid, true);
1763 }
1764
1765 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1766 const char *objname, u32 *out_sid)
1767 {
1768 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1769 objname, out_sid, false);
1770 }
1771
1772 /**
1773 * security_member_sid - Compute the SID for member selection.
1774 * @ssid: source security identifier
1775 * @tsid: target security identifier
1776 * @tclass: target security class
1777 * @out_sid: security identifier for selected member
1778 *
1779 * Compute a SID to use when selecting a member of a polyinstantiated
1780 * object of class @tclass based on a SID pair (@ssid, @tsid).
1781 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1782 * if insufficient memory is available, or %0 if the SID was
1783 * computed successfully.
1784 */
1785 int security_member_sid(u32 ssid,
1786 u32 tsid,
1787 u16 tclass,
1788 u32 *out_sid)
1789 {
1790 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1791 out_sid, false);
1792 }
1793
1794 /**
1795 * security_change_sid - Compute the SID for object relabeling.
1796 * @ssid: source security identifier
1797 * @tsid: target security identifier
1798 * @tclass: target security class
1799 * @out_sid: security identifier for selected member
1800 *
1801 * Compute a SID to use for relabeling an object of class @tclass
1802 * based on a SID pair (@ssid, @tsid).
1803 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1804 * if insufficient memory is available, or %0 if the SID was
1805 * computed successfully.
1806 */
1807 int security_change_sid(u32 ssid,
1808 u32 tsid,
1809 u16 tclass,
1810 u32 *out_sid)
1811 {
1812 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1813 out_sid, false);
1814 }
1815
1816 /* Clone the SID into the new SID table. */
1817 static int clone_sid(u32 sid,
1818 struct context *context,
1819 void *arg)
1820 {
1821 struct sidtab *s = arg;
1822
1823 if (sid > SECINITSID_NUM)
1824 return sidtab_insert(s, sid, context);
1825 else
1826 return 0;
1827 }
1828
1829 static inline int convert_context_handle_invalid_context(struct context *context)
1830 {
1831 char *s;
1832 u32 len;
1833
1834 if (selinux_enforcing)
1835 return -EINVAL;
1836
1837 if (!context_struct_to_string(context, &s, &len)) {
1838 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1839 kfree(s);
1840 }
1841 return 0;
1842 }
1843
1844 struct convert_context_args {
1845 struct policydb *oldp;
1846 struct policydb *newp;
1847 };
1848
1849 /*
1850 * Convert the values in the security context
1851 * structure `c' from the values specified
1852 * in the policy `p->oldp' to the values specified
1853 * in the policy `p->newp'. Verify that the
1854 * context is valid under the new policy.
1855 */
1856 static int convert_context(u32 key,
1857 struct context *c,
1858 void *p)
1859 {
1860 struct convert_context_args *args;
1861 struct context oldc;
1862 struct ocontext *oc;
1863 struct mls_range *range;
1864 struct role_datum *role;
1865 struct type_datum *typdatum;
1866 struct user_datum *usrdatum;
1867 char *s;
1868 u32 len;
1869 int rc = 0;
1870
1871 if (key <= SECINITSID_NUM)
1872 goto out;
1873
1874 args = p;
1875
1876 if (c->str) {
1877 struct context ctx;
1878
1879 rc = -ENOMEM;
1880 s = kstrdup(c->str, GFP_KERNEL);
1881 if (!s)
1882 goto out;
1883
1884 rc = string_to_context_struct(args->newp, NULL, s,
1885 c->len, &ctx, SECSID_NULL);
1886 kfree(s);
1887 if (!rc) {
1888 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1889 c->str);
1890 /* Replace string with mapped representation. */
1891 kfree(c->str);
1892 memcpy(c, &ctx, sizeof(*c));
1893 goto out;
1894 } else if (rc == -EINVAL) {
1895 /* Retain string representation for later mapping. */
1896 rc = 0;
1897 goto out;
1898 } else {
1899 /* Other error condition, e.g. ENOMEM. */
1900 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1901 c->str, -rc);
1902 goto out;
1903 }
1904 }
1905
1906 rc = context_cpy(&oldc, c);
1907 if (rc)
1908 goto out;
1909
1910 /* Convert the user. */
1911 rc = -EINVAL;
1912 usrdatum = hashtab_search(args->newp->p_users.table,
1913 sym_name(args->oldp, SYM_USERS, c->user - 1));
1914 if (!usrdatum)
1915 goto bad;
1916 c->user = usrdatum->value;
1917
1918 /* Convert the role. */
1919 rc = -EINVAL;
1920 role = hashtab_search(args->newp->p_roles.table,
1921 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1922 if (!role)
1923 goto bad;
1924 c->role = role->value;
1925
1926 /* Convert the type. */
1927 rc = -EINVAL;
1928 typdatum = hashtab_search(args->newp->p_types.table,
1929 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1930 if (!typdatum)
1931 goto bad;
1932 c->type = typdatum->value;
1933
1934 /* Convert the MLS fields if dealing with MLS policies */
1935 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1936 rc = mls_convert_context(args->oldp, args->newp, c);
1937 if (rc)
1938 goto bad;
1939 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1940 /*
1941 * Switching between MLS and non-MLS policy:
1942 * free any storage used by the MLS fields in the
1943 * context for all existing entries in the sidtab.
1944 */
1945 mls_context_destroy(c);
1946 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1947 /*
1948 * Switching between non-MLS and MLS policy:
1949 * ensure that the MLS fields of the context for all
1950 * existing entries in the sidtab are filled in with a
1951 * suitable default value, likely taken from one of the
1952 * initial SIDs.
1953 */
1954 oc = args->newp->ocontexts[OCON_ISID];
1955 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1956 oc = oc->next;
1957 rc = -EINVAL;
1958 if (!oc) {
1959 printk(KERN_ERR "SELinux: unable to look up"
1960 " the initial SIDs list\n");
1961 goto bad;
1962 }
1963 range = &oc->context[0].range;
1964 rc = mls_range_set(c, range);
1965 if (rc)
1966 goto bad;
1967 }
1968
1969 /* Check the validity of the new context. */
1970 if (!policydb_context_isvalid(args->newp, c)) {
1971 rc = convert_context_handle_invalid_context(&oldc);
1972 if (rc)
1973 goto bad;
1974 }
1975
1976 context_destroy(&oldc);
1977
1978 rc = 0;
1979 out:
1980 return rc;
1981 bad:
1982 /* Map old representation to string and save it. */
1983 rc = context_struct_to_string(&oldc, &s, &len);
1984 if (rc)
1985 return rc;
1986 context_destroy(&oldc);
1987 context_destroy(c);
1988 c->str = s;
1989 c->len = len;
1990 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1991 c->str);
1992 rc = 0;
1993 goto out;
1994 }
1995
1996 static void security_load_policycaps(void)
1997 {
1998 unsigned int i;
1999 struct ebitmap_node *node;
2000
2001 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
2002 POLICYDB_CAPABILITY_NETPEER);
2003 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
2004 POLICYDB_CAPABILITY_OPENPERM);
2005 selinux_policycap_extsockclass = ebitmap_get_bit(&policydb.policycaps,
2006 POLICYDB_CAPABILITY_EXTSOCKCLASS);
2007 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
2008 POLICYDB_CAPABILITY_ALWAYSNETWORK);
2009 selinux_policycap_cgroupseclabel =
2010 ebitmap_get_bit(&policydb.policycaps,
2011 POLICYDB_CAPABILITY_CGROUPSECLABEL);
2012 selinux_policycap_nnp_nosuid_transition =
2013 ebitmap_get_bit(&policydb.policycaps,
2014 POLICYDB_CAPABILITY_NNP_NOSUID_TRANSITION);
2015
2016 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2017 pr_info("SELinux: policy capability %s=%d\n",
2018 selinux_policycap_names[i],
2019 ebitmap_get_bit(&policydb.policycaps, i));
2020
2021 ebitmap_for_each_positive_bit(&policydb.policycaps, node, i) {
2022 if (i >= ARRAY_SIZE(selinux_policycap_names))
2023 pr_info("SELinux: unknown policy capability %u\n",
2024 i);
2025 }
2026 }
2027
2028 static int security_preserve_bools(struct policydb *p);
2029
2030 /**
2031 * security_load_policy - Load a security policy configuration.
2032 * @data: binary policy data
2033 * @len: length of data in bytes
2034 *
2035 * Load a new set of security policy configuration data,
2036 * validate it and convert the SID table as necessary.
2037 * This function will flush the access vector cache after
2038 * loading the new policy.
2039 */
2040 int security_load_policy(void *data, size_t len)
2041 {
2042 struct policydb *oldpolicydb, *newpolicydb;
2043 struct sidtab oldsidtab, newsidtab;
2044 struct selinux_mapping *oldmap, *map = NULL;
2045 struct convert_context_args args;
2046 u32 seqno;
2047 u16 map_size;
2048 int rc = 0;
2049 struct policy_file file = { data, len }, *fp = &file;
2050
2051 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2052 if (!oldpolicydb) {
2053 rc = -ENOMEM;
2054 goto out;
2055 }
2056 newpolicydb = oldpolicydb + 1;
2057
2058 if (!ss_initialized) {
2059 avtab_cache_init();
2060 ebitmap_cache_init();
2061 hashtab_cache_init();
2062 rc = policydb_read(&policydb, fp);
2063 if (rc) {
2064 avtab_cache_destroy();
2065 ebitmap_cache_destroy();
2066 hashtab_cache_destroy();
2067 goto out;
2068 }
2069
2070 policydb.len = len;
2071 rc = selinux_set_mapping(&policydb, secclass_map,
2072 &current_mapping,
2073 &current_mapping_size);
2074 if (rc) {
2075 policydb_destroy(&policydb);
2076 avtab_cache_destroy();
2077 ebitmap_cache_destroy();
2078 hashtab_cache_destroy();
2079 goto out;
2080 }
2081
2082 rc = policydb_load_isids(&policydb, &sidtab);
2083 if (rc) {
2084 policydb_destroy(&policydb);
2085 avtab_cache_destroy();
2086 ebitmap_cache_destroy();
2087 hashtab_cache_destroy();
2088 goto out;
2089 }
2090
2091 security_load_policycaps();
2092 ss_initialized = 1;
2093 seqno = ++latest_granting;
2094 selinux_complete_init();
2095 avc_ss_reset(seqno);
2096 selnl_notify_policyload(seqno);
2097 selinux_status_update_policyload(seqno);
2098 selinux_netlbl_cache_invalidate();
2099 selinux_xfrm_notify_policyload();
2100 goto out;
2101 }
2102
2103 #if 0
2104 sidtab_hash_eval(&sidtab, "sids");
2105 #endif
2106
2107 rc = policydb_read(newpolicydb, fp);
2108 if (rc)
2109 goto out;
2110
2111 newpolicydb->len = len;
2112 /* If switching between different policy types, log MLS status */
2113 if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2114 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2115 else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2116 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2117
2118 rc = policydb_load_isids(newpolicydb, &newsidtab);
2119 if (rc) {
2120 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
2121 policydb_destroy(newpolicydb);
2122 goto out;
2123 }
2124
2125 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2126 if (rc)
2127 goto err;
2128
2129 rc = security_preserve_bools(newpolicydb);
2130 if (rc) {
2131 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
2132 goto err;
2133 }
2134
2135 /* Clone the SID table. */
2136 sidtab_shutdown(&sidtab);
2137
2138 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2139 if (rc)
2140 goto err;
2141
2142 /*
2143 * Convert the internal representations of contexts
2144 * in the new SID table.
2145 */
2146 args.oldp = &policydb;
2147 args.newp = newpolicydb;
2148 rc = sidtab_map(&newsidtab, convert_context, &args);
2149 if (rc) {
2150 printk(KERN_ERR "SELinux: unable to convert the internal"
2151 " representation of contexts in the new SID"
2152 " table\n");
2153 goto err;
2154 }
2155
2156 /* Save the old policydb and SID table to free later. */
2157 memcpy(oldpolicydb, &policydb, sizeof(policydb));
2158 sidtab_set(&oldsidtab, &sidtab);
2159
2160 /* Install the new policydb and SID table. */
2161 write_lock_irq(&policy_rwlock);
2162 memcpy(&policydb, newpolicydb, sizeof(policydb));
2163 sidtab_set(&sidtab, &newsidtab);
2164 security_load_policycaps();
2165 oldmap = current_mapping;
2166 current_mapping = map;
2167 current_mapping_size = map_size;
2168 seqno = ++latest_granting;
2169 write_unlock_irq(&policy_rwlock);
2170
2171 /* Free the old policydb and SID table. */
2172 policydb_destroy(oldpolicydb);
2173 sidtab_destroy(&oldsidtab);
2174 kfree(oldmap);
2175
2176 avc_ss_reset(seqno);
2177 selnl_notify_policyload(seqno);
2178 selinux_status_update_policyload(seqno);
2179 selinux_netlbl_cache_invalidate();
2180 selinux_xfrm_notify_policyload();
2181
2182 rc = 0;
2183 goto out;
2184
2185 err:
2186 kfree(map);
2187 sidtab_destroy(&newsidtab);
2188 policydb_destroy(newpolicydb);
2189
2190 out:
2191 kfree(oldpolicydb);
2192 return rc;
2193 }
2194
2195 size_t security_policydb_len(void)
2196 {
2197 size_t len;
2198
2199 read_lock(&policy_rwlock);
2200 len = policydb.len;
2201 read_unlock(&policy_rwlock);
2202
2203 return len;
2204 }
2205
2206 /**
2207 * security_port_sid - Obtain the SID for a port.
2208 * @protocol: protocol number
2209 * @port: port number
2210 * @out_sid: security identifier
2211 */
2212 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2213 {
2214 struct ocontext *c;
2215 int rc = 0;
2216
2217 read_lock(&policy_rwlock);
2218
2219 c = policydb.ocontexts[OCON_PORT];
2220 while (c) {
2221 if (c->u.port.protocol == protocol &&
2222 c->u.port.low_port <= port &&
2223 c->u.port.high_port >= port)
2224 break;
2225 c = c->next;
2226 }
2227
2228 if (c) {
2229 if (!c->sid[0]) {
2230 rc = sidtab_context_to_sid(&sidtab,
2231 &c->context[0],
2232 &c->sid[0]);
2233 if (rc)
2234 goto out;
2235 }
2236 *out_sid = c->sid[0];
2237 } else {
2238 *out_sid = SECINITSID_PORT;
2239 }
2240
2241 out:
2242 read_unlock(&policy_rwlock);
2243 return rc;
2244 }
2245
2246 /**
2247 * security_pkey_sid - Obtain the SID for a pkey.
2248 * @subnet_prefix: Subnet Prefix
2249 * @pkey_num: pkey number
2250 * @out_sid: security identifier
2251 */
2252 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2253 {
2254 struct ocontext *c;
2255 int rc = 0;
2256
2257 read_lock(&policy_rwlock);
2258
2259 c = policydb.ocontexts[OCON_IBPKEY];
2260 while (c) {
2261 if (c->u.ibpkey.low_pkey <= pkey_num &&
2262 c->u.ibpkey.high_pkey >= pkey_num &&
2263 c->u.ibpkey.subnet_prefix == subnet_prefix)
2264 break;
2265
2266 c = c->next;
2267 }
2268
2269 if (c) {
2270 if (!c->sid[0]) {
2271 rc = sidtab_context_to_sid(&sidtab,
2272 &c->context[0],
2273 &c->sid[0]);
2274 if (rc)
2275 goto out;
2276 }
2277 *out_sid = c->sid[0];
2278 } else
2279 *out_sid = SECINITSID_UNLABELED;
2280
2281 out:
2282 read_unlock(&policy_rwlock);
2283 return rc;
2284 }
2285
2286 /**
2287 * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2288 * @dev_name: device name
2289 * @port: port number
2290 * @out_sid: security identifier
2291 */
2292 int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid)
2293 {
2294 struct ocontext *c;
2295 int rc = 0;
2296
2297 read_lock(&policy_rwlock);
2298
2299 c = policydb.ocontexts[OCON_IBENDPORT];
2300 while (c) {
2301 if (c->u.ibendport.port == port_num &&
2302 !strncmp(c->u.ibendport.dev_name,
2303 dev_name,
2304 IB_DEVICE_NAME_MAX))
2305 break;
2306
2307 c = c->next;
2308 }
2309
2310 if (c) {
2311 if (!c->sid[0]) {
2312 rc = sidtab_context_to_sid(&sidtab,
2313 &c->context[0],
2314 &c->sid[0]);
2315 if (rc)
2316 goto out;
2317 }
2318 *out_sid = c->sid[0];
2319 } else
2320 *out_sid = SECINITSID_UNLABELED;
2321
2322 out:
2323 read_unlock(&policy_rwlock);
2324 return rc;
2325 }
2326
2327 /**
2328 * security_netif_sid - Obtain the SID for a network interface.
2329 * @name: interface name
2330 * @if_sid: interface SID
2331 */
2332 int security_netif_sid(char *name, u32 *if_sid)
2333 {
2334 int rc = 0;
2335 struct ocontext *c;
2336
2337 read_lock(&policy_rwlock);
2338
2339 c = policydb.ocontexts[OCON_NETIF];
2340 while (c) {
2341 if (strcmp(name, c->u.name) == 0)
2342 break;
2343 c = c->next;
2344 }
2345
2346 if (c) {
2347 if (!c->sid[0] || !c->sid[1]) {
2348 rc = sidtab_context_to_sid(&sidtab,
2349 &c->context[0],
2350 &c->sid[0]);
2351 if (rc)
2352 goto out;
2353 rc = sidtab_context_to_sid(&sidtab,
2354 &c->context[1],
2355 &c->sid[1]);
2356 if (rc)
2357 goto out;
2358 }
2359 *if_sid = c->sid[0];
2360 } else
2361 *if_sid = SECINITSID_NETIF;
2362
2363 out:
2364 read_unlock(&policy_rwlock);
2365 return rc;
2366 }
2367
2368 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2369 {
2370 int i, fail = 0;
2371
2372 for (i = 0; i < 4; i++)
2373 if (addr[i] != (input[i] & mask[i])) {
2374 fail = 1;
2375 break;
2376 }
2377
2378 return !fail;
2379 }
2380
2381 /**
2382 * security_node_sid - Obtain the SID for a node (host).
2383 * @domain: communication domain aka address family
2384 * @addrp: address
2385 * @addrlen: address length in bytes
2386 * @out_sid: security identifier
2387 */
2388 int security_node_sid(u16 domain,
2389 void *addrp,
2390 u32 addrlen,
2391 u32 *out_sid)
2392 {
2393 int rc;
2394 struct ocontext *c;
2395
2396 read_lock(&policy_rwlock);
2397
2398 switch (domain) {
2399 case AF_INET: {
2400 u32 addr;
2401
2402 rc = -EINVAL;
2403 if (addrlen != sizeof(u32))
2404 goto out;
2405
2406 addr = *((u32 *)addrp);
2407
2408 c = policydb.ocontexts[OCON_NODE];
2409 while (c) {
2410 if (c->u.node.addr == (addr & c->u.node.mask))
2411 break;
2412 c = c->next;
2413 }
2414 break;
2415 }
2416
2417 case AF_INET6:
2418 rc = -EINVAL;
2419 if (addrlen != sizeof(u64) * 2)
2420 goto out;
2421 c = policydb.ocontexts[OCON_NODE6];
2422 while (c) {
2423 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2424 c->u.node6.mask))
2425 break;
2426 c = c->next;
2427 }
2428 break;
2429
2430 default:
2431 rc = 0;
2432 *out_sid = SECINITSID_NODE;
2433 goto out;
2434 }
2435
2436 if (c) {
2437 if (!c->sid[0]) {
2438 rc = sidtab_context_to_sid(&sidtab,
2439 &c->context[0],
2440 &c->sid[0]);
2441 if (rc)
2442 goto out;
2443 }
2444 *out_sid = c->sid[0];
2445 } else {
2446 *out_sid = SECINITSID_NODE;
2447 }
2448
2449 rc = 0;
2450 out:
2451 read_unlock(&policy_rwlock);
2452 return rc;
2453 }
2454
2455 #define SIDS_NEL 25
2456
2457 /**
2458 * security_get_user_sids - Obtain reachable SIDs for a user.
2459 * @fromsid: starting SID
2460 * @username: username
2461 * @sids: array of reachable SIDs for user
2462 * @nel: number of elements in @sids
2463 *
2464 * Generate the set of SIDs for legal security contexts
2465 * for a given user that can be reached by @fromsid.
2466 * Set *@sids to point to a dynamically allocated
2467 * array containing the set of SIDs. Set *@nel to the
2468 * number of elements in the array.
2469 */
2470
2471 int security_get_user_sids(u32 fromsid,
2472 char *username,
2473 u32 **sids,
2474 u32 *nel)
2475 {
2476 struct context *fromcon, usercon;
2477 u32 *mysids = NULL, *mysids2, sid;
2478 u32 mynel = 0, maxnel = SIDS_NEL;
2479 struct user_datum *user;
2480 struct role_datum *role;
2481 struct ebitmap_node *rnode, *tnode;
2482 int rc = 0, i, j;
2483
2484 *sids = NULL;
2485 *nel = 0;
2486
2487 if (!ss_initialized)
2488 goto out;
2489
2490 read_lock(&policy_rwlock);
2491
2492 context_init(&usercon);
2493
2494 rc = -EINVAL;
2495 fromcon = sidtab_search(&sidtab, fromsid);
2496 if (!fromcon)
2497 goto out_unlock;
2498
2499 rc = -EINVAL;
2500 user = hashtab_search(policydb.p_users.table, username);
2501 if (!user)
2502 goto out_unlock;
2503
2504 usercon.user = user->value;
2505
2506 rc = -ENOMEM;
2507 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2508 if (!mysids)
2509 goto out_unlock;
2510
2511 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2512 role = policydb.role_val_to_struct[i];
2513 usercon.role = i + 1;
2514 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2515 usercon.type = j + 1;
2516
2517 if (mls_setup_user_range(fromcon, user, &usercon))
2518 continue;
2519
2520 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2521 if (rc)
2522 goto out_unlock;
2523 if (mynel < maxnel) {
2524 mysids[mynel++] = sid;
2525 } else {
2526 rc = -ENOMEM;
2527 maxnel += SIDS_NEL;
2528 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2529 if (!mysids2)
2530 goto out_unlock;
2531 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2532 kfree(mysids);
2533 mysids = mysids2;
2534 mysids[mynel++] = sid;
2535 }
2536 }
2537 }
2538 rc = 0;
2539 out_unlock:
2540 read_unlock(&policy_rwlock);
2541 if (rc || !mynel) {
2542 kfree(mysids);
2543 goto out;
2544 }
2545
2546 rc = -ENOMEM;
2547 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2548 if (!mysids2) {
2549 kfree(mysids);
2550 goto out;
2551 }
2552 for (i = 0, j = 0; i < mynel; i++) {
2553 struct av_decision dummy_avd;
2554 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2555 SECCLASS_PROCESS, /* kernel value */
2556 PROCESS__TRANSITION, AVC_STRICT,
2557 &dummy_avd);
2558 if (!rc)
2559 mysids2[j++] = mysids[i];
2560 cond_resched();
2561 }
2562 rc = 0;
2563 kfree(mysids);
2564 *sids = mysids2;
2565 *nel = j;
2566 out:
2567 return rc;
2568 }
2569
2570 /**
2571 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2572 * @fstype: filesystem type
2573 * @path: path from root of mount
2574 * @sclass: file security class
2575 * @sid: SID for path
2576 *
2577 * Obtain a SID to use for a file in a filesystem that
2578 * cannot support xattr or use a fixed labeling behavior like
2579 * transition SIDs or task SIDs.
2580 *
2581 * The caller must acquire the policy_rwlock before calling this function.
2582 */
2583 static inline int __security_genfs_sid(const char *fstype,
2584 char *path,
2585 u16 orig_sclass,
2586 u32 *sid)
2587 {
2588 int len;
2589 u16 sclass;
2590 struct genfs *genfs;
2591 struct ocontext *c;
2592 int rc, cmp = 0;
2593
2594 while (path[0] == '/' && path[1] == '/')
2595 path++;
2596
2597 sclass = unmap_class(orig_sclass);
2598 *sid = SECINITSID_UNLABELED;
2599
2600 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2601 cmp = strcmp(fstype, genfs->fstype);
2602 if (cmp <= 0)
2603 break;
2604 }
2605
2606 rc = -ENOENT;
2607 if (!genfs || cmp)
2608 goto out;
2609
2610 for (c = genfs->head; c; c = c->next) {
2611 len = strlen(c->u.name);
2612 if ((!c->v.sclass || sclass == c->v.sclass) &&
2613 (strncmp(c->u.name, path, len) == 0))
2614 break;
2615 }
2616
2617 rc = -ENOENT;
2618 if (!c)
2619 goto out;
2620
2621 if (!c->sid[0]) {
2622 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2623 if (rc)
2624 goto out;
2625 }
2626
2627 *sid = c->sid[0];
2628 rc = 0;
2629 out:
2630 return rc;
2631 }
2632
2633 /**
2634 * security_genfs_sid - Obtain a SID for a file in a filesystem
2635 * @fstype: filesystem type
2636 * @path: path from root of mount
2637 * @sclass: file security class
2638 * @sid: SID for path
2639 *
2640 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2641 * it afterward.
2642 */
2643 int security_genfs_sid(const char *fstype,
2644 char *path,
2645 u16 orig_sclass,
2646 u32 *sid)
2647 {
2648 int retval;
2649
2650 read_lock(&policy_rwlock);
2651 retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2652 read_unlock(&policy_rwlock);
2653 return retval;
2654 }
2655
2656 /**
2657 * security_fs_use - Determine how to handle labeling for a filesystem.
2658 * @sb: superblock in question
2659 */
2660 int security_fs_use(struct super_block *sb)
2661 {
2662 int rc = 0;
2663 struct ocontext *c;
2664 struct superblock_security_struct *sbsec = sb->s_security;
2665 const char *fstype = sb->s_type->name;
2666
2667 read_lock(&policy_rwlock);
2668
2669 c = policydb.ocontexts[OCON_FSUSE];
2670 while (c) {
2671 if (strcmp(fstype, c->u.name) == 0)
2672 break;
2673 c = c->next;
2674 }
2675
2676 if (c) {
2677 sbsec->behavior = c->v.behavior;
2678 if (!c->sid[0]) {
2679 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2680 &c->sid[0]);
2681 if (rc)
2682 goto out;
2683 }
2684 sbsec->sid = c->sid[0];
2685 } else {
2686 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2687 &sbsec->sid);
2688 if (rc) {
2689 sbsec->behavior = SECURITY_FS_USE_NONE;
2690 rc = 0;
2691 } else {
2692 sbsec->behavior = SECURITY_FS_USE_GENFS;
2693 }
2694 }
2695
2696 out:
2697 read_unlock(&policy_rwlock);
2698 return rc;
2699 }
2700
2701 int security_get_bools(int *len, char ***names, int **values)
2702 {
2703 int i, rc;
2704
2705 read_lock(&policy_rwlock);
2706 *names = NULL;
2707 *values = NULL;
2708
2709 rc = 0;
2710 *len = policydb.p_bools.nprim;
2711 if (!*len)
2712 goto out;
2713
2714 rc = -ENOMEM;
2715 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2716 if (!*names)
2717 goto err;
2718
2719 rc = -ENOMEM;
2720 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2721 if (!*values)
2722 goto err;
2723
2724 for (i = 0; i < *len; i++) {
2725 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2726
2727 rc = -ENOMEM;
2728 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2729 if (!(*names)[i])
2730 goto err;
2731 }
2732 rc = 0;
2733 out:
2734 read_unlock(&policy_rwlock);
2735 return rc;
2736 err:
2737 if (*names) {
2738 for (i = 0; i < *len; i++)
2739 kfree((*names)[i]);
2740 }
2741 kfree(*values);
2742 goto out;
2743 }
2744
2745
2746 int security_set_bools(int len, int *values)
2747 {
2748 int i, rc;
2749 int lenp, seqno = 0;
2750 struct cond_node *cur;
2751
2752 write_lock_irq(&policy_rwlock);
2753
2754 rc = -EFAULT;
2755 lenp = policydb.p_bools.nprim;
2756 if (len != lenp)
2757 goto out;
2758
2759 for (i = 0; i < len; i++) {
2760 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2761 audit_log(current->audit_context, GFP_ATOMIC,
2762 AUDIT_MAC_CONFIG_CHANGE,
2763 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2764 sym_name(&policydb, SYM_BOOLS, i),
2765 !!values[i],
2766 policydb.bool_val_to_struct[i]->state,
2767 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2768 audit_get_sessionid(current));
2769 }
2770 if (values[i])
2771 policydb.bool_val_to_struct[i]->state = 1;
2772 else
2773 policydb.bool_val_to_struct[i]->state = 0;
2774 }
2775
2776 for (cur = policydb.cond_list; cur; cur = cur->next) {
2777 rc = evaluate_cond_node(&policydb, cur);
2778 if (rc)
2779 goto out;
2780 }
2781
2782 seqno = ++latest_granting;
2783 rc = 0;
2784 out:
2785 write_unlock_irq(&policy_rwlock);
2786 if (!rc) {
2787 avc_ss_reset(seqno);
2788 selnl_notify_policyload(seqno);
2789 selinux_status_update_policyload(seqno);
2790 selinux_xfrm_notify_policyload();
2791 }
2792 return rc;
2793 }
2794
2795 int security_get_bool_value(int index)
2796 {
2797 int rc;
2798 int len;
2799
2800 read_lock(&policy_rwlock);
2801
2802 rc = -EFAULT;
2803 len = policydb.p_bools.nprim;
2804 if (index >= len)
2805 goto out;
2806
2807 rc = policydb.bool_val_to_struct[index]->state;
2808 out:
2809 read_unlock(&policy_rwlock);
2810 return rc;
2811 }
2812
2813 static int security_preserve_bools(struct policydb *p)
2814 {
2815 int rc, nbools = 0, *bvalues = NULL, i;
2816 char **bnames = NULL;
2817 struct cond_bool_datum *booldatum;
2818 struct cond_node *cur;
2819
2820 rc = security_get_bools(&nbools, &bnames, &bvalues);
2821 if (rc)
2822 goto out;
2823 for (i = 0; i < nbools; i++) {
2824 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2825 if (booldatum)
2826 booldatum->state = bvalues[i];
2827 }
2828 for (cur = p->cond_list; cur; cur = cur->next) {
2829 rc = evaluate_cond_node(p, cur);
2830 if (rc)
2831 goto out;
2832 }
2833
2834 out:
2835 if (bnames) {
2836 for (i = 0; i < nbools; i++)
2837 kfree(bnames[i]);
2838 }
2839 kfree(bnames);
2840 kfree(bvalues);
2841 return rc;
2842 }
2843
2844 /*
2845 * security_sid_mls_copy() - computes a new sid based on the given
2846 * sid and the mls portion of mls_sid.
2847 */
2848 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2849 {
2850 struct context *context1;
2851 struct context *context2;
2852 struct context newcon;
2853 char *s;
2854 u32 len;
2855 int rc;
2856
2857 rc = 0;
2858 if (!ss_initialized || !policydb.mls_enabled) {
2859 *new_sid = sid;
2860 goto out;
2861 }
2862
2863 context_init(&newcon);
2864
2865 read_lock(&policy_rwlock);
2866
2867 rc = -EINVAL;
2868 context1 = sidtab_search(&sidtab, sid);
2869 if (!context1) {
2870 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2871 __func__, sid);
2872 goto out_unlock;
2873 }
2874
2875 rc = -EINVAL;
2876 context2 = sidtab_search(&sidtab, mls_sid);
2877 if (!context2) {
2878 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2879 __func__, mls_sid);
2880 goto out_unlock;
2881 }
2882
2883 newcon.user = context1->user;
2884 newcon.role = context1->role;
2885 newcon.type = context1->type;
2886 rc = mls_context_cpy(&newcon, context2);
2887 if (rc)
2888 goto out_unlock;
2889
2890 /* Check the validity of the new context. */
2891 if (!policydb_context_isvalid(&policydb, &newcon)) {
2892 rc = convert_context_handle_invalid_context(&newcon);
2893 if (rc) {
2894 if (!context_struct_to_string(&newcon, &s, &len)) {
2895 audit_log(current->audit_context,
2896 GFP_ATOMIC, AUDIT_SELINUX_ERR,
2897 "op=security_sid_mls_copy "
2898 "invalid_context=%s", s);
2899 kfree(s);
2900 }
2901 goto out_unlock;
2902 }
2903 }
2904
2905 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2906 out_unlock:
2907 read_unlock(&policy_rwlock);
2908 context_destroy(&newcon);
2909 out:
2910 return rc;
2911 }
2912
2913 /**
2914 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2915 * @nlbl_sid: NetLabel SID
2916 * @nlbl_type: NetLabel labeling protocol type
2917 * @xfrm_sid: XFRM SID
2918 *
2919 * Description:
2920 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2921 * resolved into a single SID it is returned via @peer_sid and the function
2922 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2923 * returns a negative value. A table summarizing the behavior is below:
2924 *
2925 * | function return | @sid
2926 * ------------------------------+-----------------+-----------------
2927 * no peer labels | 0 | SECSID_NULL
2928 * single peer label | 0 | <peer_label>
2929 * multiple, consistent labels | 0 | <peer_label>
2930 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2931 *
2932 */
2933 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2934 u32 xfrm_sid,
2935 u32 *peer_sid)
2936 {
2937 int rc;
2938 struct context *nlbl_ctx;
2939 struct context *xfrm_ctx;
2940
2941 *peer_sid = SECSID_NULL;
2942
2943 /* handle the common (which also happens to be the set of easy) cases
2944 * right away, these two if statements catch everything involving a
2945 * single or absent peer SID/label */
2946 if (xfrm_sid == SECSID_NULL) {
2947 *peer_sid = nlbl_sid;
2948 return 0;
2949 }
2950 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2951 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2952 * is present */
2953 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2954 *peer_sid = xfrm_sid;
2955 return 0;
2956 }
2957
2958 /* we don't need to check ss_initialized here since the only way both
2959 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2960 * security server was initialized and ss_initialized was true */
2961 if (!policydb.mls_enabled)
2962 return 0;
2963
2964 read_lock(&policy_rwlock);
2965
2966 rc = -EINVAL;
2967 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2968 if (!nlbl_ctx) {
2969 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2970 __func__, nlbl_sid);
2971 goto out;
2972 }
2973 rc = -EINVAL;
2974 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2975 if (!xfrm_ctx) {
2976 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2977 __func__, xfrm_sid);
2978 goto out;
2979 }
2980 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2981 if (rc)
2982 goto out;
2983
2984 /* at present NetLabel SIDs/labels really only carry MLS
2985 * information so if the MLS portion of the NetLabel SID
2986 * matches the MLS portion of the labeled XFRM SID/label
2987 * then pass along the XFRM SID as it is the most
2988 * expressive */
2989 *peer_sid = xfrm_sid;
2990 out:
2991 read_unlock(&policy_rwlock);
2992 return rc;
2993 }
2994
2995 static int get_classes_callback(void *k, void *d, void *args)
2996 {
2997 struct class_datum *datum = d;
2998 char *name = k, **classes = args;
2999 int value = datum->value - 1;
3000
3001 classes[value] = kstrdup(name, GFP_ATOMIC);
3002 if (!classes[value])
3003 return -ENOMEM;
3004
3005 return 0;
3006 }
3007
3008 int security_get_classes(char ***classes, int *nclasses)
3009 {
3010 int rc;
3011
3012 read_lock(&policy_rwlock);
3013
3014 rc = -ENOMEM;
3015 *nclasses = policydb.p_classes.nprim;
3016 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3017 if (!*classes)
3018 goto out;
3019
3020 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
3021 *classes);
3022 if (rc) {
3023 int i;
3024 for (i = 0; i < *nclasses; i++)
3025 kfree((*classes)[i]);
3026 kfree(*classes);
3027 }
3028
3029 out:
3030 read_unlock(&policy_rwlock);
3031 return rc;
3032 }
3033
3034 static int get_permissions_callback(void *k, void *d, void *args)
3035 {
3036 struct perm_datum *datum = d;
3037 char *name = k, **perms = args;
3038 int value = datum->value - 1;
3039
3040 perms[value] = kstrdup(name, GFP_ATOMIC);
3041 if (!perms[value])
3042 return -ENOMEM;
3043
3044 return 0;
3045 }
3046
3047 int security_get_permissions(char *class, char ***perms, int *nperms)
3048 {
3049 int rc, i;
3050 struct class_datum *match;
3051
3052 read_lock(&policy_rwlock);
3053
3054 rc = -EINVAL;
3055 match = hashtab_search(policydb.p_classes.table, class);
3056 if (!match) {
3057 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
3058 __func__, class);
3059 goto out;
3060 }
3061
3062 rc = -ENOMEM;
3063 *nperms = match->permissions.nprim;
3064 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3065 if (!*perms)
3066 goto out;
3067
3068 if (match->comdatum) {
3069 rc = hashtab_map(match->comdatum->permissions.table,
3070 get_permissions_callback, *perms);
3071 if (rc)
3072 goto err;
3073 }
3074
3075 rc = hashtab_map(match->permissions.table, get_permissions_callback,
3076 *perms);
3077 if (rc)
3078 goto err;
3079
3080 out:
3081 read_unlock(&policy_rwlock);
3082 return rc;
3083
3084 err:
3085 read_unlock(&policy_rwlock);
3086 for (i = 0; i < *nperms; i++)
3087 kfree((*perms)[i]);
3088 kfree(*perms);
3089 return rc;
3090 }
3091
3092 int security_get_reject_unknown(void)
3093 {
3094 return policydb.reject_unknown;
3095 }
3096
3097 int security_get_allow_unknown(void)
3098 {
3099 return policydb.allow_unknown;
3100 }
3101
3102 /**
3103 * security_policycap_supported - Check for a specific policy capability
3104 * @req_cap: capability
3105 *
3106 * Description:
3107 * This function queries the currently loaded policy to see if it supports the
3108 * capability specified by @req_cap. Returns true (1) if the capability is
3109 * supported, false (0) if it isn't supported.
3110 *
3111 */
3112 int security_policycap_supported(unsigned int req_cap)
3113 {
3114 int rc;
3115
3116 read_lock(&policy_rwlock);
3117 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3118 read_unlock(&policy_rwlock);
3119
3120 return rc;
3121 }
3122
3123 struct selinux_audit_rule {
3124 u32 au_seqno;
3125 struct context au_ctxt;
3126 };
3127
3128 void selinux_audit_rule_free(void *vrule)
3129 {
3130 struct selinux_audit_rule *rule = vrule;
3131
3132 if (rule) {
3133 context_destroy(&rule->au_ctxt);
3134 kfree(rule);
3135 }
3136 }
3137
3138 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3139 {
3140 struct selinux_audit_rule *tmprule;
3141 struct role_datum *roledatum;
3142 struct type_datum *typedatum;
3143 struct user_datum *userdatum;
3144 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3145 int rc = 0;
3146
3147 *rule = NULL;
3148
3149 if (!ss_initialized)
3150 return -EOPNOTSUPP;
3151
3152 switch (field) {
3153 case AUDIT_SUBJ_USER:
3154 case AUDIT_SUBJ_ROLE:
3155 case AUDIT_SUBJ_TYPE:
3156 case AUDIT_OBJ_USER:
3157 case AUDIT_OBJ_ROLE:
3158 case AUDIT_OBJ_TYPE:
3159 /* only 'equals' and 'not equals' fit user, role, and type */
3160 if (op != Audit_equal && op != Audit_not_equal)
3161 return -EINVAL;
3162 break;
3163 case AUDIT_SUBJ_SEN:
3164 case AUDIT_SUBJ_CLR:
3165 case AUDIT_OBJ_LEV_LOW:
3166 case AUDIT_OBJ_LEV_HIGH:
3167 /* we do not allow a range, indicated by the presence of '-' */
3168 if (strchr(rulestr, '-'))
3169 return -EINVAL;
3170 break;
3171 default:
3172 /* only the above fields are valid */
3173 return -EINVAL;
3174 }
3175
3176 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3177 if (!tmprule)
3178 return -ENOMEM;
3179
3180 context_init(&tmprule->au_ctxt);
3181
3182 read_lock(&policy_rwlock);
3183
3184 tmprule->au_seqno = latest_granting;
3185
3186 switch (field) {
3187 case AUDIT_SUBJ_USER:
3188 case AUDIT_OBJ_USER:
3189 rc = -EINVAL;
3190 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3191 if (!userdatum)
3192 goto out;
3193 tmprule->au_ctxt.user = userdatum->value;
3194 break;
3195 case AUDIT_SUBJ_ROLE:
3196 case AUDIT_OBJ_ROLE:
3197 rc = -EINVAL;
3198 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3199 if (!roledatum)
3200 goto out;
3201 tmprule->au_ctxt.role = roledatum->value;
3202 break;
3203 case AUDIT_SUBJ_TYPE:
3204 case AUDIT_OBJ_TYPE:
3205 rc = -EINVAL;
3206 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3207 if (!typedatum)
3208 goto out;
3209 tmprule->au_ctxt.type = typedatum->value;
3210 break;
3211 case AUDIT_SUBJ_SEN:
3212 case AUDIT_SUBJ_CLR:
3213 case AUDIT_OBJ_LEV_LOW:
3214 case AUDIT_OBJ_LEV_HIGH:
3215 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3216 if (rc)
3217 goto out;
3218 break;
3219 }
3220 rc = 0;
3221 out:
3222 read_unlock(&policy_rwlock);
3223
3224 if (rc) {
3225 selinux_audit_rule_free(tmprule);
3226 tmprule = NULL;
3227 }
3228
3229 *rule = tmprule;
3230
3231 return rc;
3232 }
3233
3234 /* Check to see if the rule contains any selinux fields */
3235 int selinux_audit_rule_known(struct audit_krule *rule)
3236 {
3237 int i;
3238
3239 for (i = 0; i < rule->field_count; i++) {
3240 struct audit_field *f = &rule->fields[i];
3241 switch (f->type) {
3242 case AUDIT_SUBJ_USER:
3243 case AUDIT_SUBJ_ROLE:
3244 case AUDIT_SUBJ_TYPE:
3245 case AUDIT_SUBJ_SEN:
3246 case AUDIT_SUBJ_CLR:
3247 case AUDIT_OBJ_USER:
3248 case AUDIT_OBJ_ROLE:
3249 case AUDIT_OBJ_TYPE:
3250 case AUDIT_OBJ_LEV_LOW:
3251 case AUDIT_OBJ_LEV_HIGH:
3252 return 1;
3253 }
3254 }
3255
3256 return 0;
3257 }
3258
3259 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3260 struct audit_context *actx)
3261 {
3262 struct context *ctxt;
3263 struct mls_level *level;
3264 struct selinux_audit_rule *rule = vrule;
3265 int match = 0;
3266
3267 if (unlikely(!rule)) {
3268 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3269 return -ENOENT;
3270 }
3271
3272 read_lock(&policy_rwlock);
3273
3274 if (rule->au_seqno < latest_granting) {
3275 match = -ESTALE;
3276 goto out;
3277 }
3278
3279 ctxt = sidtab_search(&sidtab, sid);
3280 if (unlikely(!ctxt)) {
3281 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3282 sid);
3283 match = -ENOENT;
3284 goto out;
3285 }
3286
3287 /* a field/op pair that is not caught here will simply fall through
3288 without a match */
3289 switch (field) {
3290 case AUDIT_SUBJ_USER:
3291 case AUDIT_OBJ_USER:
3292 switch (op) {
3293 case Audit_equal:
3294 match = (ctxt->user == rule->au_ctxt.user);
3295 break;
3296 case Audit_not_equal:
3297 match = (ctxt->user != rule->au_ctxt.user);
3298 break;
3299 }
3300 break;
3301 case AUDIT_SUBJ_ROLE:
3302 case AUDIT_OBJ_ROLE:
3303 switch (op) {
3304 case Audit_equal:
3305 match = (ctxt->role == rule->au_ctxt.role);
3306 break;
3307 case Audit_not_equal:
3308 match = (ctxt->role != rule->au_ctxt.role);
3309 break;
3310 }
3311 break;
3312 case AUDIT_SUBJ_TYPE:
3313 case AUDIT_OBJ_TYPE:
3314 switch (op) {
3315 case Audit_equal:
3316 match = (ctxt->type == rule->au_ctxt.type);
3317 break;
3318 case Audit_not_equal:
3319 match = (ctxt->type != rule->au_ctxt.type);
3320 break;
3321 }
3322 break;
3323 case AUDIT_SUBJ_SEN:
3324 case AUDIT_SUBJ_CLR:
3325 case AUDIT_OBJ_LEV_LOW:
3326 case AUDIT_OBJ_LEV_HIGH:
3327 level = ((field == AUDIT_SUBJ_SEN ||
3328 field == AUDIT_OBJ_LEV_LOW) ?
3329 &ctxt->range.level[0] : &ctxt->range.level[1]);
3330 switch (op) {
3331 case Audit_equal:
3332 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3333 level);
3334 break;
3335 case Audit_not_equal:
3336 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3337 level);
3338 break;
3339 case Audit_lt:
3340 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3341 level) &&
3342 !mls_level_eq(&rule->au_ctxt.range.level[0],
3343 level));
3344 break;
3345 case Audit_le:
3346 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3347 level);
3348 break;
3349 case Audit_gt:
3350 match = (mls_level_dom(level,
3351 &rule->au_ctxt.range.level[0]) &&
3352 !mls_level_eq(level,
3353 &rule->au_ctxt.range.level[0]));
3354 break;
3355 case Audit_ge:
3356 match = mls_level_dom(level,
3357 &rule->au_ctxt.range.level[0]);
3358 break;
3359 }
3360 }
3361
3362 out:
3363 read_unlock(&policy_rwlock);
3364 return match;
3365 }
3366
3367 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3368
3369 static int aurule_avc_callback(u32 event)
3370 {
3371 int err = 0;
3372
3373 if (event == AVC_CALLBACK_RESET && aurule_callback)
3374 err = aurule_callback();
3375 return err;
3376 }
3377
3378 static int __init aurule_init(void)
3379 {
3380 int err;
3381
3382 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3383 if (err)
3384 panic("avc_add_callback() failed, error %d\n", err);
3385
3386 return err;
3387 }
3388 __initcall(aurule_init);
3389
3390 #ifdef CONFIG_NETLABEL
3391 /**
3392 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3393 * @secattr: the NetLabel packet security attributes
3394 * @sid: the SELinux SID
3395 *
3396 * Description:
3397 * Attempt to cache the context in @ctx, which was derived from the packet in
3398 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3399 * already been initialized.
3400 *
3401 */
3402 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3403 u32 sid)
3404 {
3405 u32 *sid_cache;
3406
3407 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3408 if (sid_cache == NULL)
3409 return;
3410 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3411 if (secattr->cache == NULL) {
3412 kfree(sid_cache);
3413 return;
3414 }
3415
3416 *sid_cache = sid;
3417 secattr->cache->free = kfree;
3418 secattr->cache->data = sid_cache;
3419 secattr->flags |= NETLBL_SECATTR_CACHE;
3420 }
3421
3422 /**
3423 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3424 * @secattr: the NetLabel packet security attributes
3425 * @sid: the SELinux SID
3426 *
3427 * Description:
3428 * Convert the given NetLabel security attributes in @secattr into a
3429 * SELinux SID. If the @secattr field does not contain a full SELinux
3430 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3431 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3432 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3433 * conversion for future lookups. Returns zero on success, negative values on
3434 * failure.
3435 *
3436 */
3437 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3438 u32 *sid)
3439 {
3440 int rc;
3441 struct context *ctx;
3442 struct context ctx_new;
3443
3444 if (!ss_initialized) {
3445 *sid = SECSID_NULL;
3446 return 0;
3447 }
3448
3449 read_lock(&policy_rwlock);
3450
3451 if (secattr->flags & NETLBL_SECATTR_CACHE)
3452 *sid = *(u32 *)secattr->cache->data;
3453 else if (secattr->flags & NETLBL_SECATTR_SECID)
3454 *sid = secattr->attr.secid;
3455 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3456 rc = -EIDRM;
3457 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3458 if (ctx == NULL)
3459 goto out;
3460
3461 context_init(&ctx_new);
3462 ctx_new.user = ctx->user;
3463 ctx_new.role = ctx->role;
3464 ctx_new.type = ctx->type;
3465 mls_import_netlbl_lvl(&ctx_new, secattr);
3466 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3467 rc = mls_import_netlbl_cat(&ctx_new, secattr);
3468 if (rc)
3469 goto out;
3470 }
3471 rc = -EIDRM;
3472 if (!mls_context_isvalid(&policydb, &ctx_new))
3473 goto out_free;
3474
3475 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3476 if (rc)
3477 goto out_free;
3478
3479 security_netlbl_cache_add(secattr, *sid);
3480
3481 ebitmap_destroy(&ctx_new.range.level[0].cat);
3482 } else
3483 *sid = SECSID_NULL;
3484
3485 read_unlock(&policy_rwlock);
3486 return 0;
3487 out_free:
3488 ebitmap_destroy(&ctx_new.range.level[0].cat);
3489 out:
3490 read_unlock(&policy_rwlock);
3491 return rc;
3492 }
3493
3494 /**
3495 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3496 * @sid: the SELinux SID
3497 * @secattr: the NetLabel packet security attributes
3498 *
3499 * Description:
3500 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3501 * Returns zero on success, negative values on failure.
3502 *
3503 */
3504 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3505 {
3506 int rc;
3507 struct context *ctx;
3508
3509 if (!ss_initialized)
3510 return 0;
3511
3512 read_lock(&policy_rwlock);
3513
3514 rc = -ENOENT;
3515 ctx = sidtab_search(&sidtab, sid);
3516 if (ctx == NULL)
3517 goto out;
3518
3519 rc = -ENOMEM;
3520 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3521 GFP_ATOMIC);
3522 if (secattr->domain == NULL)
3523 goto out;
3524
3525 secattr->attr.secid = sid;
3526 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3527 mls_export_netlbl_lvl(ctx, secattr);
3528 rc = mls_export_netlbl_cat(ctx, secattr);
3529 out:
3530 read_unlock(&policy_rwlock);
3531 return rc;
3532 }
3533 #endif /* CONFIG_NETLABEL */
3534
3535 /**
3536 * security_read_policy - read the policy.
3537 * @data: binary policy data
3538 * @len: length of data in bytes
3539 *
3540 */
3541 int security_read_policy(void **data, size_t *len)
3542 {
3543 int rc;
3544 struct policy_file fp;
3545
3546 if (!ss_initialized)
3547 return -EINVAL;
3548
3549 *len = security_policydb_len();
3550
3551 *data = vmalloc_user(*len);
3552 if (!*data)
3553 return -ENOMEM;
3554
3555 fp.data = *data;
3556 fp.len = *len;
3557
3558 read_lock(&policy_rwlock);
3559 rc = policydb_write(&policydb, &fp);
3560 read_unlock(&policy_rwlock);
3561
3562 if (rc)
3563 return rc;
3564
3565 *len = (unsigned long)fp.data - (unsigned long)*data;
3566 return 0;
3567
3568 }
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