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Merge tag 'riscv-for-linus-4.15-rc2_cleanups' of git://git.kernel.org/pub/scm/linux...
[linux/fpc-iii.git] / security / selinux / ss / services.c
blob33cfe5d3d6cb8cbda6927310aa10954f5d01f3a1
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 if (!ss_initialized) {
1417 int i;
1418
1419 for (i = 1; i < SECINITSID_NUM; i++) {
1420 if (!strcmp(initial_sid_to_string[i], scontext)) {
1421 *sid = i;
1422 return 0;
1423 }
1424 }
1425 *sid = SECINITSID_KERNEL;
1426 return 0;
1427 }
1428 *sid = SECSID_NULL;
1429
1430 /* Copy the string so that we can modify the copy as we parse it. */
1431 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1432 if (!scontext2)
1433 return -ENOMEM;
1434 memcpy(scontext2, scontext, scontext_len);
1435 scontext2[scontext_len] = 0;
1436
1437 if (force) {
1438 /* Save another copy for storing in uninterpreted form */
1439 rc = -ENOMEM;
1440 str = kstrdup(scontext2, gfp_flags);
1441 if (!str)
1442 goto out;
1443 }
1444
1445 read_lock(&policy_rwlock);
1446 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1447 scontext_len, &context, def_sid);
1448 if (rc == -EINVAL && force) {
1449 context.str = str;
1450 context.len = scontext_len;
1451 str = NULL;
1452 } else if (rc)
1453 goto out_unlock;
1454 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1455 context_destroy(&context);
1456 out_unlock:
1457 read_unlock(&policy_rwlock);
1458 out:
1459 kfree(scontext2);
1460 kfree(str);
1461 return rc;
1462 }
1463
1464 /**
1465 * security_context_to_sid - Obtain a SID for a given security context.
1466 * @scontext: security context
1467 * @scontext_len: length in bytes
1468 * @sid: security identifier, SID
1469 * @gfp: context for the allocation
1470 *
1471 * Obtains a SID associated with the security context that
1472 * has the string representation specified by @scontext.
1473 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1474 * memory is available, or 0 on success.
1475 */
1476 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1477 gfp_t gfp)
1478 {
1479 return security_context_to_sid_core(scontext, scontext_len,
1480 sid, SECSID_NULL, gfp, 0);
1481 }
1482
1483 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1484 {
1485 return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1486 }
1487
1488 /**
1489 * security_context_to_sid_default - Obtain a SID for a given security context,
1490 * falling back to specified default if needed.
1491 *
1492 * @scontext: security context
1493 * @scontext_len: length in bytes
1494 * @sid: security identifier, SID
1495 * @def_sid: default SID to assign on error
1496 *
1497 * Obtains a SID associated with the security context that
1498 * has the string representation specified by @scontext.
1499 * The default SID is passed to the MLS layer to be used to allow
1500 * kernel labeling of the MLS field if the MLS field is not present
1501 * (for upgrading to MLS without full relabel).
1502 * Implicitly forces adding of the context even if it cannot be mapped yet.
1503 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1504 * memory is available, or 0 on success.
1505 */
1506 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1507 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1508 {
1509 return security_context_to_sid_core(scontext, scontext_len,
1510 sid, def_sid, gfp_flags, 1);
1511 }
1512
1513 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1514 u32 *sid)
1515 {
1516 return security_context_to_sid_core(scontext, scontext_len,
1517 sid, SECSID_NULL, GFP_KERNEL, 1);
1518 }
1519
1520 static int compute_sid_handle_invalid_context(
1521 struct context *scontext,
1522 struct context *tcontext,
1523 u16 tclass,
1524 struct context *newcontext)
1525 {
1526 char *s = NULL, *t = NULL, *n = NULL;
1527 u32 slen, tlen, nlen;
1528
1529 if (context_struct_to_string(scontext, &s, &slen))
1530 goto out;
1531 if (context_struct_to_string(tcontext, &t, &tlen))
1532 goto out;
1533 if (context_struct_to_string(newcontext, &n, &nlen))
1534 goto out;
1535 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1536 "op=security_compute_sid invalid_context=%s"
1537 " scontext=%s"
1538 " tcontext=%s"
1539 " tclass=%s",
1540 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1541 out:
1542 kfree(s);
1543 kfree(t);
1544 kfree(n);
1545 if (!selinux_enforcing)
1546 return 0;
1547 return -EACCES;
1548 }
1549
1550 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1551 u32 stype, u32 ttype, u16 tclass,
1552 const char *objname)
1553 {
1554 struct filename_trans ft;
1555 struct filename_trans_datum *otype;
1556
1557 /*
1558 * Most filename trans rules are going to live in specific directories
1559 * like /dev or /var/run. This bitmap will quickly skip rule searches
1560 * if the ttype does not contain any rules.
1561 */
1562 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1563 return;
1564
1565 ft.stype = stype;
1566 ft.ttype = ttype;
1567 ft.tclass = tclass;
1568 ft.name = objname;
1569
1570 otype = hashtab_search(p->filename_trans, &ft);
1571 if (otype)
1572 newcontext->type = otype->otype;
1573 }
1574
1575 static int security_compute_sid(u32 ssid,
1576 u32 tsid,
1577 u16 orig_tclass,
1578 u32 specified,
1579 const char *objname,
1580 u32 *out_sid,
1581 bool kern)
1582 {
1583 struct class_datum *cladatum = NULL;
1584 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1585 struct role_trans *roletr = NULL;
1586 struct avtab_key avkey;
1587 struct avtab_datum *avdatum;
1588 struct avtab_node *node;
1589 u16 tclass;
1590 int rc = 0;
1591 bool sock;
1592
1593 if (!ss_initialized) {
1594 switch (orig_tclass) {
1595 case SECCLASS_PROCESS: /* kernel value */
1596 *out_sid = ssid;
1597 break;
1598 default:
1599 *out_sid = tsid;
1600 break;
1601 }
1602 goto out;
1603 }
1604
1605 context_init(&newcontext);
1606
1607 read_lock(&policy_rwlock);
1608
1609 if (kern) {
1610 tclass = unmap_class(orig_tclass);
1611 sock = security_is_socket_class(orig_tclass);
1612 } else {
1613 tclass = orig_tclass;
1614 sock = security_is_socket_class(map_class(tclass));
1615 }
1616
1617 scontext = sidtab_search(&sidtab, ssid);
1618 if (!scontext) {
1619 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1620 __func__, ssid);
1621 rc = -EINVAL;
1622 goto out_unlock;
1623 }
1624 tcontext = sidtab_search(&sidtab, tsid);
1625 if (!tcontext) {
1626 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1627 __func__, tsid);
1628 rc = -EINVAL;
1629 goto out_unlock;
1630 }
1631
1632 if (tclass && tclass <= policydb.p_classes.nprim)
1633 cladatum = policydb.class_val_to_struct[tclass - 1];
1634
1635 /* Set the user identity. */
1636 switch (specified) {
1637 case AVTAB_TRANSITION:
1638 case AVTAB_CHANGE:
1639 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1640 newcontext.user = tcontext->user;
1641 } else {
1642 /* notice this gets both DEFAULT_SOURCE and unset */
1643 /* Use the process user identity. */
1644 newcontext.user = scontext->user;
1645 }
1646 break;
1647 case AVTAB_MEMBER:
1648 /* Use the related object owner. */
1649 newcontext.user = tcontext->user;
1650 break;
1651 }
1652
1653 /* Set the role to default values. */
1654 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1655 newcontext.role = scontext->role;
1656 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1657 newcontext.role = tcontext->role;
1658 } else {
1659 if ((tclass == policydb.process_class) || (sock == true))
1660 newcontext.role = scontext->role;
1661 else
1662 newcontext.role = OBJECT_R_VAL;
1663 }
1664
1665 /* Set the type to default values. */
1666 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1667 newcontext.type = scontext->type;
1668 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1669 newcontext.type = tcontext->type;
1670 } else {
1671 if ((tclass == policydb.process_class) || (sock == true)) {
1672 /* Use the type of process. */
1673 newcontext.type = scontext->type;
1674 } else {
1675 /* Use the type of the related object. */
1676 newcontext.type = tcontext->type;
1677 }
1678 }
1679
1680 /* Look for a type transition/member/change rule. */
1681 avkey.source_type = scontext->type;
1682 avkey.target_type = tcontext->type;
1683 avkey.target_class = tclass;
1684 avkey.specified = specified;
1685 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1686
1687 /* If no permanent rule, also check for enabled conditional rules */
1688 if (!avdatum) {
1689 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1690 for (; node; node = avtab_search_node_next(node, specified)) {
1691 if (node->key.specified & AVTAB_ENABLED) {
1692 avdatum = &node->datum;
1693 break;
1694 }
1695 }
1696 }
1697
1698 if (avdatum) {
1699 /* Use the type from the type transition/member/change rule. */
1700 newcontext.type = avdatum->u.data;
1701 }
1702
1703 /* if we have a objname this is a file trans check so check those rules */
1704 if (objname)
1705 filename_compute_type(&policydb, &newcontext, scontext->type,
1706 tcontext->type, tclass, objname);
1707
1708 /* Check for class-specific changes. */
1709 if (specified & AVTAB_TRANSITION) {
1710 /* Look for a role transition rule. */
1711 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1712 if ((roletr->role == scontext->role) &&
1713 (roletr->type == tcontext->type) &&
1714 (roletr->tclass == tclass)) {
1715 /* Use the role transition rule. */
1716 newcontext.role = roletr->new_role;
1717 break;
1718 }
1719 }
1720 }
1721
1722 /* Set the MLS attributes.
1723 This is done last because it may allocate memory. */
1724 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1725 &newcontext, sock);
1726 if (rc)
1727 goto out_unlock;
1728
1729 /* Check the validity of the context. */
1730 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1731 rc = compute_sid_handle_invalid_context(scontext,
1732 tcontext,
1733 tclass,
1734 &newcontext);
1735 if (rc)
1736 goto out_unlock;
1737 }
1738 /* Obtain the sid for the context. */
1739 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1740 out_unlock:
1741 read_unlock(&policy_rwlock);
1742 context_destroy(&newcontext);
1743 out:
1744 return rc;
1745 }
1746
1747 /**
1748 * security_transition_sid - Compute the SID for a new subject/object.
1749 * @ssid: source security identifier
1750 * @tsid: target security identifier
1751 * @tclass: target security class
1752 * @out_sid: security identifier for new subject/object
1753 *
1754 * Compute a SID to use for labeling a new subject or object in the
1755 * class @tclass based on a SID pair (@ssid, @tsid).
1756 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1757 * if insufficient memory is available, or %0 if the new SID was
1758 * computed successfully.
1759 */
1760 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1761 const struct qstr *qstr, u32 *out_sid)
1762 {
1763 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1764 qstr ? qstr->name : NULL, out_sid, true);
1765 }
1766
1767 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1768 const char *objname, u32 *out_sid)
1769 {
1770 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1771 objname, out_sid, false);
1772 }
1773
1774 /**
1775 * security_member_sid - Compute the SID for member selection.
1776 * @ssid: source security identifier
1777 * @tsid: target security identifier
1778 * @tclass: target security class
1779 * @out_sid: security identifier for selected member
1780 *
1781 * Compute a SID to use when selecting a member of a polyinstantiated
1782 * object of class @tclass based on a SID pair (@ssid, @tsid).
1783 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1784 * if insufficient memory is available, or %0 if the SID was
1785 * computed successfully.
1786 */
1787 int security_member_sid(u32 ssid,
1788 u32 tsid,
1789 u16 tclass,
1790 u32 *out_sid)
1791 {
1792 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1793 out_sid, false);
1794 }
1795
1796 /**
1797 * security_change_sid - Compute the SID for object relabeling.
1798 * @ssid: source security identifier
1799 * @tsid: target security identifier
1800 * @tclass: target security class
1801 * @out_sid: security identifier for selected member
1802 *
1803 * Compute a SID to use for relabeling an object of class @tclass
1804 * based on a SID pair (@ssid, @tsid).
1805 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1806 * if insufficient memory is available, or %0 if the SID was
1807 * computed successfully.
1808 */
1809 int security_change_sid(u32 ssid,
1810 u32 tsid,
1811 u16 tclass,
1812 u32 *out_sid)
1813 {
1814 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1815 out_sid, false);
1816 }
1817
1818 /* Clone the SID into the new SID table. */
1819 static int clone_sid(u32 sid,
1820 struct context *context,
1821 void *arg)
1822 {
1823 struct sidtab *s = arg;
1824
1825 if (sid > SECINITSID_NUM)
1826 return sidtab_insert(s, sid, context);
1827 else
1828 return 0;
1829 }
1830
1831 static inline int convert_context_handle_invalid_context(struct context *context)
1832 {
1833 char *s;
1834 u32 len;
1835
1836 if (selinux_enforcing)
1837 return -EINVAL;
1838
1839 if (!context_struct_to_string(context, &s, &len)) {
1840 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1841 kfree(s);
1842 }
1843 return 0;
1844 }
1845
1846 struct convert_context_args {
1847 struct policydb *oldp;
1848 struct policydb *newp;
1849 };
1850
1851 /*
1852 * Convert the values in the security context
1853 * structure `c' from the values specified
1854 * in the policy `p->oldp' to the values specified
1855 * in the policy `p->newp'. Verify that the
1856 * context is valid under the new policy.
1857 */
1858 static int convert_context(u32 key,
1859 struct context *c,
1860 void *p)
1861 {
1862 struct convert_context_args *args;
1863 struct context oldc;
1864 struct ocontext *oc;
1865 struct mls_range *range;
1866 struct role_datum *role;
1867 struct type_datum *typdatum;
1868 struct user_datum *usrdatum;
1869 char *s;
1870 u32 len;
1871 int rc = 0;
1872
1873 if (key <= SECINITSID_NUM)
1874 goto out;
1875
1876 args = p;
1877
1878 if (c->str) {
1879 struct context ctx;
1880
1881 rc = -ENOMEM;
1882 s = kstrdup(c->str, GFP_KERNEL);
1883 if (!s)
1884 goto out;
1885
1886 rc = string_to_context_struct(args->newp, NULL, s,
1887 c->len, &ctx, SECSID_NULL);
1888 kfree(s);
1889 if (!rc) {
1890 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1891 c->str);
1892 /* Replace string with mapped representation. */
1893 kfree(c->str);
1894 memcpy(c, &ctx, sizeof(*c));
1895 goto out;
1896 } else if (rc == -EINVAL) {
1897 /* Retain string representation for later mapping. */
1898 rc = 0;
1899 goto out;
1900 } else {
1901 /* Other error condition, e.g. ENOMEM. */
1902 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1903 c->str, -rc);
1904 goto out;
1905 }
1906 }
1907
1908 rc = context_cpy(&oldc, c);
1909 if (rc)
1910 goto out;
1911
1912 /* Convert the user. */
1913 rc = -EINVAL;
1914 usrdatum = hashtab_search(args->newp->p_users.table,
1915 sym_name(args->oldp, SYM_USERS, c->user - 1));
1916 if (!usrdatum)
1917 goto bad;
1918 c->user = usrdatum->value;
1919
1920 /* Convert the role. */
1921 rc = -EINVAL;
1922 role = hashtab_search(args->newp->p_roles.table,
1923 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1924 if (!role)
1925 goto bad;
1926 c->role = role->value;
1927
1928 /* Convert the type. */
1929 rc = -EINVAL;
1930 typdatum = hashtab_search(args->newp->p_types.table,
1931 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1932 if (!typdatum)
1933 goto bad;
1934 c->type = typdatum->value;
1935
1936 /* Convert the MLS fields if dealing with MLS policies */
1937 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1938 rc = mls_convert_context(args->oldp, args->newp, c);
1939 if (rc)
1940 goto bad;
1941 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1942 /*
1943 * Switching between MLS and non-MLS policy:
1944 * free any storage used by the MLS fields in the
1945 * context for all existing entries in the sidtab.
1946 */
1947 mls_context_destroy(c);
1948 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1949 /*
1950 * Switching between non-MLS and MLS policy:
1951 * ensure that the MLS fields of the context for all
1952 * existing entries in the sidtab are filled in with a
1953 * suitable default value, likely taken from one of the
1954 * initial SIDs.
1955 */
1956 oc = args->newp->ocontexts[OCON_ISID];
1957 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1958 oc = oc->next;
1959 rc = -EINVAL;
1960 if (!oc) {
1961 printk(KERN_ERR "SELinux: unable to look up"
1962 " the initial SIDs list\n");
1963 goto bad;
1964 }
1965 range = &oc->context[0].range;
1966 rc = mls_range_set(c, range);
1967 if (rc)
1968 goto bad;
1969 }
1970
1971 /* Check the validity of the new context. */
1972 if (!policydb_context_isvalid(args->newp, c)) {
1973 rc = convert_context_handle_invalid_context(&oldc);
1974 if (rc)
1975 goto bad;
1976 }
1977
1978 context_destroy(&oldc);
1979
1980 rc = 0;
1981 out:
1982 return rc;
1983 bad:
1984 /* Map old representation to string and save it. */
1985 rc = context_struct_to_string(&oldc, &s, &len);
1986 if (rc)
1987 return rc;
1988 context_destroy(&oldc);
1989 context_destroy(c);
1990 c->str = s;
1991 c->len = len;
1992 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1993 c->str);
1994 rc = 0;
1995 goto out;
1996 }
1997
1998 static void security_load_policycaps(void)
1999 {
2000 unsigned int i;
2001 struct ebitmap_node *node;
2002
2003 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
2004 POLICYDB_CAPABILITY_NETPEER);
2005 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
2006 POLICYDB_CAPABILITY_OPENPERM);
2007 selinux_policycap_extsockclass = ebitmap_get_bit(&policydb.policycaps,
2008 POLICYDB_CAPABILITY_EXTSOCKCLASS);
2009 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
2010 POLICYDB_CAPABILITY_ALWAYSNETWORK);
2011 selinux_policycap_cgroupseclabel =
2012 ebitmap_get_bit(&policydb.policycaps,
2013 POLICYDB_CAPABILITY_CGROUPSECLABEL);
2014 selinux_policycap_nnp_nosuid_transition =
2015 ebitmap_get_bit(&policydb.policycaps,
2016 POLICYDB_CAPABILITY_NNP_NOSUID_TRANSITION);
2017
2018 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2019 pr_info("SELinux: policy capability %s=%d\n",
2020 selinux_policycap_names[i],
2021 ebitmap_get_bit(&policydb.policycaps, i));
2022
2023 ebitmap_for_each_positive_bit(&policydb.policycaps, node, i) {
2024 if (i >= ARRAY_SIZE(selinux_policycap_names))
2025 pr_info("SELinux: unknown policy capability %u\n",
2026 i);
2027 }
2028 }
2029
2030 static int security_preserve_bools(struct policydb *p);
2031
2032 /**
2033 * security_load_policy - Load a security policy configuration.
2034 * @data: binary policy data
2035 * @len: length of data in bytes
2036 *
2037 * Load a new set of security policy configuration data,
2038 * validate it and convert the SID table as necessary.
2039 * This function will flush the access vector cache after
2040 * loading the new policy.
2041 */
2042 int security_load_policy(void *data, size_t len)
2043 {
2044 struct policydb *oldpolicydb, *newpolicydb;
2045 struct sidtab oldsidtab, newsidtab;
2046 struct selinux_mapping *oldmap, *map = NULL;
2047 struct convert_context_args args;
2048 u32 seqno;
2049 u16 map_size;
2050 int rc = 0;
2051 struct policy_file file = { data, len }, *fp = &file;
2052
2053 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2054 if (!oldpolicydb) {
2055 rc = -ENOMEM;
2056 goto out;
2057 }
2058 newpolicydb = oldpolicydb + 1;
2059
2060 if (!ss_initialized) {
2061 avtab_cache_init();
2062 ebitmap_cache_init();
2063 hashtab_cache_init();
2064 rc = policydb_read(&policydb, fp);
2065 if (rc) {
2066 avtab_cache_destroy();
2067 ebitmap_cache_destroy();
2068 hashtab_cache_destroy();
2069 goto out;
2070 }
2071
2072 policydb.len = len;
2073 rc = selinux_set_mapping(&policydb, secclass_map,
2074 &current_mapping,
2075 &current_mapping_size);
2076 if (rc) {
2077 policydb_destroy(&policydb);
2078 avtab_cache_destroy();
2079 ebitmap_cache_destroy();
2080 hashtab_cache_destroy();
2081 goto out;
2082 }
2083
2084 rc = policydb_load_isids(&policydb, &sidtab);
2085 if (rc) {
2086 policydb_destroy(&policydb);
2087 avtab_cache_destroy();
2088 ebitmap_cache_destroy();
2089 hashtab_cache_destroy();
2090 goto out;
2091 }
2092
2093 security_load_policycaps();
2094 ss_initialized = 1;
2095 seqno = ++latest_granting;
2096 selinux_complete_init();
2097 avc_ss_reset(seqno);
2098 selnl_notify_policyload(seqno);
2099 selinux_status_update_policyload(seqno);
2100 selinux_netlbl_cache_invalidate();
2101 selinux_xfrm_notify_policyload();
2102 goto out;
2103 }
2104
2105 #if 0
2106 sidtab_hash_eval(&sidtab, "sids");
2107 #endif
2108
2109 rc = policydb_read(newpolicydb, fp);
2110 if (rc)
2111 goto out;
2112
2113 newpolicydb->len = len;
2114 /* If switching between different policy types, log MLS status */
2115 if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2116 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2117 else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2118 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2119
2120 rc = policydb_load_isids(newpolicydb, &newsidtab);
2121 if (rc) {
2122 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
2123 policydb_destroy(newpolicydb);
2124 goto out;
2125 }
2126
2127 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2128 if (rc)
2129 goto err;
2130
2131 rc = security_preserve_bools(newpolicydb);
2132 if (rc) {
2133 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
2134 goto err;
2135 }
2136
2137 /* Clone the SID table. */
2138 sidtab_shutdown(&sidtab);
2139
2140 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2141 if (rc)
2142 goto err;
2143
2144 /*
2145 * Convert the internal representations of contexts
2146 * in the new SID table.
2147 */
2148 args.oldp = &policydb;
2149 args.newp = newpolicydb;
2150 rc = sidtab_map(&newsidtab, convert_context, &args);
2151 if (rc) {
2152 printk(KERN_ERR "SELinux: unable to convert the internal"
2153 " representation of contexts in the new SID"
2154 " table\n");
2155 goto err;
2156 }
2157
2158 /* Save the old policydb and SID table to free later. */
2159 memcpy(oldpolicydb, &policydb, sizeof(policydb));
2160 sidtab_set(&oldsidtab, &sidtab);
2161
2162 /* Install the new policydb and SID table. */
2163 write_lock_irq(&policy_rwlock);
2164 memcpy(&policydb, newpolicydb, sizeof(policydb));
2165 sidtab_set(&sidtab, &newsidtab);
2166 security_load_policycaps();
2167 oldmap = current_mapping;
2168 current_mapping = map;
2169 current_mapping_size = map_size;
2170 seqno = ++latest_granting;
2171 write_unlock_irq(&policy_rwlock);
2172
2173 /* Free the old policydb and SID table. */
2174 policydb_destroy(oldpolicydb);
2175 sidtab_destroy(&oldsidtab);
2176 kfree(oldmap);
2177
2178 avc_ss_reset(seqno);
2179 selnl_notify_policyload(seqno);
2180 selinux_status_update_policyload(seqno);
2181 selinux_netlbl_cache_invalidate();
2182 selinux_xfrm_notify_policyload();
2183
2184 rc = 0;
2185 goto out;
2186
2187 err:
2188 kfree(map);
2189 sidtab_destroy(&newsidtab);
2190 policydb_destroy(newpolicydb);
2191
2192 out:
2193 kfree(oldpolicydb);
2194 return rc;
2195 }
2196
2197 size_t security_policydb_len(void)
2198 {
2199 size_t len;
2200
2201 read_lock(&policy_rwlock);
2202 len = policydb.len;
2203 read_unlock(&policy_rwlock);
2204
2205 return len;
2206 }
2207
2208 /**
2209 * security_port_sid - Obtain the SID for a port.
2210 * @protocol: protocol number
2211 * @port: port number
2212 * @out_sid: security identifier
2213 */
2214 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2215 {
2216 struct ocontext *c;
2217 int rc = 0;
2218
2219 read_lock(&policy_rwlock);
2220
2221 c = policydb.ocontexts[OCON_PORT];
2222 while (c) {
2223 if (c->u.port.protocol == protocol &&
2224 c->u.port.low_port <= port &&
2225 c->u.port.high_port >= port)
2226 break;
2227 c = c->next;
2228 }
2229
2230 if (c) {
2231 if (!c->sid[0]) {
2232 rc = sidtab_context_to_sid(&sidtab,
2233 &c->context[0],
2234 &c->sid[0]);
2235 if (rc)
2236 goto out;
2237 }
2238 *out_sid = c->sid[0];
2239 } else {
2240 *out_sid = SECINITSID_PORT;
2241 }
2242
2243 out:
2244 read_unlock(&policy_rwlock);
2245 return rc;
2246 }
2247
2248 /**
2249 * security_pkey_sid - Obtain the SID for a pkey.
2250 * @subnet_prefix: Subnet Prefix
2251 * @pkey_num: pkey number
2252 * @out_sid: security identifier
2253 */
2254 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2255 {
2256 struct ocontext *c;
2257 int rc = 0;
2258
2259 read_lock(&policy_rwlock);
2260
2261 c = policydb.ocontexts[OCON_IBPKEY];
2262 while (c) {
2263 if (c->u.ibpkey.low_pkey <= pkey_num &&
2264 c->u.ibpkey.high_pkey >= pkey_num &&
2265 c->u.ibpkey.subnet_prefix == subnet_prefix)
2266 break;
2267
2268 c = c->next;
2269 }
2270
2271 if (c) {
2272 if (!c->sid[0]) {
2273 rc = sidtab_context_to_sid(&sidtab,
2274 &c->context[0],
2275 &c->sid[0]);
2276 if (rc)
2277 goto out;
2278 }
2279 *out_sid = c->sid[0];
2280 } else
2281 *out_sid = SECINITSID_UNLABELED;
2282
2283 out:
2284 read_unlock(&policy_rwlock);
2285 return rc;
2286 }
2287
2288 /**
2289 * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2290 * @dev_name: device name
2291 * @port: port number
2292 * @out_sid: security identifier
2293 */
2294 int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid)
2295 {
2296 struct ocontext *c;
2297 int rc = 0;
2298
2299 read_lock(&policy_rwlock);
2300
2301 c = policydb.ocontexts[OCON_IBENDPORT];
2302 while (c) {
2303 if (c->u.ibendport.port == port_num &&
2304 !strncmp(c->u.ibendport.dev_name,
2305 dev_name,
2306 IB_DEVICE_NAME_MAX))
2307 break;
2308
2309 c = c->next;
2310 }
2311
2312 if (c) {
2313 if (!c->sid[0]) {
2314 rc = sidtab_context_to_sid(&sidtab,
2315 &c->context[0],
2316 &c->sid[0]);
2317 if (rc)
2318 goto out;
2319 }
2320 *out_sid = c->sid[0];
2321 } else
2322 *out_sid = SECINITSID_UNLABELED;
2323
2324 out:
2325 read_unlock(&policy_rwlock);
2326 return rc;
2327 }
2328
2329 /**
2330 * security_netif_sid - Obtain the SID for a network interface.
2331 * @name: interface name
2332 * @if_sid: interface SID
2333 */
2334 int security_netif_sid(char *name, u32 *if_sid)
2335 {
2336 int rc = 0;
2337 struct ocontext *c;
2338
2339 read_lock(&policy_rwlock);
2340
2341 c = policydb.ocontexts[OCON_NETIF];
2342 while (c) {
2343 if (strcmp(name, c->u.name) == 0)
2344 break;
2345 c = c->next;
2346 }
2347
2348 if (c) {
2349 if (!c->sid[0] || !c->sid[1]) {
2350 rc = sidtab_context_to_sid(&sidtab,
2351 &c->context[0],
2352 &c->sid[0]);
2353 if (rc)
2354 goto out;
2355 rc = sidtab_context_to_sid(&sidtab,
2356 &c->context[1],
2357 &c->sid[1]);
2358 if (rc)
2359 goto out;
2360 }
2361 *if_sid = c->sid[0];
2362 } else
2363 *if_sid = SECINITSID_NETIF;
2364
2365 out:
2366 read_unlock(&policy_rwlock);
2367 return rc;
2368 }
2369
2370 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2371 {
2372 int i, fail = 0;
2373
2374 for (i = 0; i < 4; i++)
2375 if (addr[i] != (input[i] & mask[i])) {
2376 fail = 1;
2377 break;
2378 }
2379
2380 return !fail;
2381 }
2382
2383 /**
2384 * security_node_sid - Obtain the SID for a node (host).
2385 * @domain: communication domain aka address family
2386 * @addrp: address
2387 * @addrlen: address length in bytes
2388 * @out_sid: security identifier
2389 */
2390 int security_node_sid(u16 domain,
2391 void *addrp,
2392 u32 addrlen,
2393 u32 *out_sid)
2394 {
2395 int rc;
2396 struct ocontext *c;
2397
2398 read_lock(&policy_rwlock);
2399
2400 switch (domain) {
2401 case AF_INET: {
2402 u32 addr;
2403
2404 rc = -EINVAL;
2405 if (addrlen != sizeof(u32))
2406 goto out;
2407
2408 addr = *((u32 *)addrp);
2409
2410 c = policydb.ocontexts[OCON_NODE];
2411 while (c) {
2412 if (c->u.node.addr == (addr & c->u.node.mask))
2413 break;
2414 c = c->next;
2415 }
2416 break;
2417 }
2418
2419 case AF_INET6:
2420 rc = -EINVAL;
2421 if (addrlen != sizeof(u64) * 2)
2422 goto out;
2423 c = policydb.ocontexts[OCON_NODE6];
2424 while (c) {
2425 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2426 c->u.node6.mask))
2427 break;
2428 c = c->next;
2429 }
2430 break;
2431
2432 default:
2433 rc = 0;
2434 *out_sid = SECINITSID_NODE;
2435 goto out;
2436 }
2437
2438 if (c) {
2439 if (!c->sid[0]) {
2440 rc = sidtab_context_to_sid(&sidtab,
2441 &c->context[0],
2442 &c->sid[0]);
2443 if (rc)
2444 goto out;
2445 }
2446 *out_sid = c->sid[0];
2447 } else {
2448 *out_sid = SECINITSID_NODE;
2449 }
2450
2451 rc = 0;
2452 out:
2453 read_unlock(&policy_rwlock);
2454 return rc;
2455 }
2456
2457 #define SIDS_NEL 25
2458
2459 /**
2460 * security_get_user_sids - Obtain reachable SIDs for a user.
2461 * @fromsid: starting SID
2462 * @username: username
2463 * @sids: array of reachable SIDs for user
2464 * @nel: number of elements in @sids
2465 *
2466 * Generate the set of SIDs for legal security contexts
2467 * for a given user that can be reached by @fromsid.
2468 * Set *@sids to point to a dynamically allocated
2469 * array containing the set of SIDs. Set *@nel to the
2470 * number of elements in the array.
2471 */
2472
2473 int security_get_user_sids(u32 fromsid,
2474 char *username,
2475 u32 **sids,
2476 u32 *nel)
2477 {
2478 struct context *fromcon, usercon;
2479 u32 *mysids = NULL, *mysids2, sid;
2480 u32 mynel = 0, maxnel = SIDS_NEL;
2481 struct user_datum *user;
2482 struct role_datum *role;
2483 struct ebitmap_node *rnode, *tnode;
2484 int rc = 0, i, j;
2485
2486 *sids = NULL;
2487 *nel = 0;
2488
2489 if (!ss_initialized)
2490 goto out;
2491
2492 read_lock(&policy_rwlock);
2493
2494 context_init(&usercon);
2495
2496 rc = -EINVAL;
2497 fromcon = sidtab_search(&sidtab, fromsid);
2498 if (!fromcon)
2499 goto out_unlock;
2500
2501 rc = -EINVAL;
2502 user = hashtab_search(policydb.p_users.table, username);
2503 if (!user)
2504 goto out_unlock;
2505
2506 usercon.user = user->value;
2507
2508 rc = -ENOMEM;
2509 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2510 if (!mysids)
2511 goto out_unlock;
2512
2513 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2514 role = policydb.role_val_to_struct[i];
2515 usercon.role = i + 1;
2516 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2517 usercon.type = j + 1;
2518
2519 if (mls_setup_user_range(fromcon, user, &usercon))
2520 continue;
2521
2522 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2523 if (rc)
2524 goto out_unlock;
2525 if (mynel < maxnel) {
2526 mysids[mynel++] = sid;
2527 } else {
2528 rc = -ENOMEM;
2529 maxnel += SIDS_NEL;
2530 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2531 if (!mysids2)
2532 goto out_unlock;
2533 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2534 kfree(mysids);
2535 mysids = mysids2;
2536 mysids[mynel++] = sid;
2537 }
2538 }
2539 }
2540 rc = 0;
2541 out_unlock:
2542 read_unlock(&policy_rwlock);
2543 if (rc || !mynel) {
2544 kfree(mysids);
2545 goto out;
2546 }
2547
2548 rc = -ENOMEM;
2549 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2550 if (!mysids2) {
2551 kfree(mysids);
2552 goto out;
2553 }
2554 for (i = 0, j = 0; i < mynel; i++) {
2555 struct av_decision dummy_avd;
2556 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2557 SECCLASS_PROCESS, /* kernel value */
2558 PROCESS__TRANSITION, AVC_STRICT,
2559 &dummy_avd);
2560 if (!rc)
2561 mysids2[j++] = mysids[i];
2562 cond_resched();
2563 }
2564 rc = 0;
2565 kfree(mysids);
2566 *sids = mysids2;
2567 *nel = j;
2568 out:
2569 return rc;
2570 }
2571
2572 /**
2573 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2574 * @fstype: filesystem type
2575 * @path: path from root of mount
2576 * @sclass: file security class
2577 * @sid: SID for path
2578 *
2579 * Obtain a SID to use for a file in a filesystem that
2580 * cannot support xattr or use a fixed labeling behavior like
2581 * transition SIDs or task SIDs.
2582 *
2583 * The caller must acquire the policy_rwlock before calling this function.
2584 */
2585 static inline int __security_genfs_sid(const char *fstype,
2586 char *path,
2587 u16 orig_sclass,
2588 u32 *sid)
2589 {
2590 int len;
2591 u16 sclass;
2592 struct genfs *genfs;
2593 struct ocontext *c;
2594 int rc, cmp = 0;
2595
2596 while (path[0] == '/' && path[1] == '/')
2597 path++;
2598
2599 sclass = unmap_class(orig_sclass);
2600 *sid = SECINITSID_UNLABELED;
2601
2602 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2603 cmp = strcmp(fstype, genfs->fstype);
2604 if (cmp <= 0)
2605 break;
2606 }
2607
2608 rc = -ENOENT;
2609 if (!genfs || cmp)
2610 goto out;
2611
2612 for (c = genfs->head; c; c = c->next) {
2613 len = strlen(c->u.name);
2614 if ((!c->v.sclass || sclass == c->v.sclass) &&
2615 (strncmp(c->u.name, path, len) == 0))
2616 break;
2617 }
2618
2619 rc = -ENOENT;
2620 if (!c)
2621 goto out;
2622
2623 if (!c->sid[0]) {
2624 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2625 if (rc)
2626 goto out;
2627 }
2628
2629 *sid = c->sid[0];
2630 rc = 0;
2631 out:
2632 return rc;
2633 }
2634
2635 /**
2636 * security_genfs_sid - Obtain a SID for a file in a filesystem
2637 * @fstype: filesystem type
2638 * @path: path from root of mount
2639 * @sclass: file security class
2640 * @sid: SID for path
2641 *
2642 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2643 * it afterward.
2644 */
2645 int security_genfs_sid(const char *fstype,
2646 char *path,
2647 u16 orig_sclass,
2648 u32 *sid)
2649 {
2650 int retval;
2651
2652 read_lock(&policy_rwlock);
2653 retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2654 read_unlock(&policy_rwlock);
2655 return retval;
2656 }
2657
2658 /**
2659 * security_fs_use - Determine how to handle labeling for a filesystem.
2660 * @sb: superblock in question
2661 */
2662 int security_fs_use(struct super_block *sb)
2663 {
2664 int rc = 0;
2665 struct ocontext *c;
2666 struct superblock_security_struct *sbsec = sb->s_security;
2667 const char *fstype = sb->s_type->name;
2668
2669 read_lock(&policy_rwlock);
2670
2671 c = policydb.ocontexts[OCON_FSUSE];
2672 while (c) {
2673 if (strcmp(fstype, c->u.name) == 0)
2674 break;
2675 c = c->next;
2676 }
2677
2678 if (c) {
2679 sbsec->behavior = c->v.behavior;
2680 if (!c->sid[0]) {
2681 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2682 &c->sid[0]);
2683 if (rc)
2684 goto out;
2685 }
2686 sbsec->sid = c->sid[0];
2687 } else {
2688 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2689 &sbsec->sid);
2690 if (rc) {
2691 sbsec->behavior = SECURITY_FS_USE_NONE;
2692 rc = 0;
2693 } else {
2694 sbsec->behavior = SECURITY_FS_USE_GENFS;
2695 }
2696 }
2697
2698 out:
2699 read_unlock(&policy_rwlock);
2700 return rc;
2701 }
2702
2703 int security_get_bools(int *len, char ***names, int **values)
2704 {
2705 int i, rc;
2706
2707 read_lock(&policy_rwlock);
2708 *names = NULL;
2709 *values = NULL;
2710
2711 rc = 0;
2712 *len = policydb.p_bools.nprim;
2713 if (!*len)
2714 goto out;
2715
2716 rc = -ENOMEM;
2717 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2718 if (!*names)
2719 goto err;
2720
2721 rc = -ENOMEM;
2722 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2723 if (!*values)
2724 goto err;
2725
2726 for (i = 0; i < *len; i++) {
2727 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2728
2729 rc = -ENOMEM;
2730 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2731 if (!(*names)[i])
2732 goto err;
2733 }
2734 rc = 0;
2735 out:
2736 read_unlock(&policy_rwlock);
2737 return rc;
2738 err:
2739 if (*names) {
2740 for (i = 0; i < *len; i++)
2741 kfree((*names)[i]);
2742 }
2743 kfree(*values);
2744 goto out;
2745 }
2746
2747
2748 int security_set_bools(int len, int *values)
2749 {
2750 int i, rc;
2751 int lenp, seqno = 0;
2752 struct cond_node *cur;
2753
2754 write_lock_irq(&policy_rwlock);
2755
2756 rc = -EFAULT;
2757 lenp = policydb.p_bools.nprim;
2758 if (len != lenp)
2759 goto out;
2760
2761 for (i = 0; i < len; i++) {
2762 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2763 audit_log(current->audit_context, GFP_ATOMIC,
2764 AUDIT_MAC_CONFIG_CHANGE,
2765 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2766 sym_name(&policydb, SYM_BOOLS, i),
2767 !!values[i],
2768 policydb.bool_val_to_struct[i]->state,
2769 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2770 audit_get_sessionid(current));
2771 }
2772 if (values[i])
2773 policydb.bool_val_to_struct[i]->state = 1;
2774 else
2775 policydb.bool_val_to_struct[i]->state = 0;
2776 }
2777
2778 for (cur = policydb.cond_list; cur; cur = cur->next) {
2779 rc = evaluate_cond_node(&policydb, cur);
2780 if (rc)
2781 goto out;
2782 }
2783
2784 seqno = ++latest_granting;
2785 rc = 0;
2786 out:
2787 write_unlock_irq(&policy_rwlock);
2788 if (!rc) {
2789 avc_ss_reset(seqno);
2790 selnl_notify_policyload(seqno);
2791 selinux_status_update_policyload(seqno);
2792 selinux_xfrm_notify_policyload();
2793 }
2794 return rc;
2795 }
2796
2797 int security_get_bool_value(int index)
2798 {
2799 int rc;
2800 int len;
2801
2802 read_lock(&policy_rwlock);
2803
2804 rc = -EFAULT;
2805 len = policydb.p_bools.nprim;
2806 if (index >= len)
2807 goto out;
2808
2809 rc = policydb.bool_val_to_struct[index]->state;
2810 out:
2811 read_unlock(&policy_rwlock);
2812 return rc;
2813 }
2814
2815 static int security_preserve_bools(struct policydb *p)
2816 {
2817 int rc, nbools = 0, *bvalues = NULL, i;
2818 char **bnames = NULL;
2819 struct cond_bool_datum *booldatum;
2820 struct cond_node *cur;
2821
2822 rc = security_get_bools(&nbools, &bnames, &bvalues);
2823 if (rc)
2824 goto out;
2825 for (i = 0; i < nbools; i++) {
2826 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2827 if (booldatum)
2828 booldatum->state = bvalues[i];
2829 }
2830 for (cur = p->cond_list; cur; cur = cur->next) {
2831 rc = evaluate_cond_node(p, cur);
2832 if (rc)
2833 goto out;
2834 }
2835
2836 out:
2837 if (bnames) {
2838 for (i = 0; i < nbools; i++)
2839 kfree(bnames[i]);
2840 }
2841 kfree(bnames);
2842 kfree(bvalues);
2843 return rc;
2844 }
2845
2846 /*
2847 * security_sid_mls_copy() - computes a new sid based on the given
2848 * sid and the mls portion of mls_sid.
2849 */
2850 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2851 {
2852 struct context *context1;
2853 struct context *context2;
2854 struct context newcon;
2855 char *s;
2856 u32 len;
2857 int rc;
2858
2859 rc = 0;
2860 if (!ss_initialized || !policydb.mls_enabled) {
2861 *new_sid = sid;
2862 goto out;
2863 }
2864
2865 context_init(&newcon);
2866
2867 read_lock(&policy_rwlock);
2868
2869 rc = -EINVAL;
2870 context1 = sidtab_search(&sidtab, sid);
2871 if (!context1) {
2872 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2873 __func__, sid);
2874 goto out_unlock;
2875 }
2876
2877 rc = -EINVAL;
2878 context2 = sidtab_search(&sidtab, mls_sid);
2879 if (!context2) {
2880 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2881 __func__, mls_sid);
2882 goto out_unlock;
2883 }
2884
2885 newcon.user = context1->user;
2886 newcon.role = context1->role;
2887 newcon.type = context1->type;
2888 rc = mls_context_cpy(&newcon, context2);
2889 if (rc)
2890 goto out_unlock;
2891
2892 /* Check the validity of the new context. */
2893 if (!policydb_context_isvalid(&policydb, &newcon)) {
2894 rc = convert_context_handle_invalid_context(&newcon);
2895 if (rc) {
2896 if (!context_struct_to_string(&newcon, &s, &len)) {
2897 audit_log(current->audit_context,
2898 GFP_ATOMIC, AUDIT_SELINUX_ERR,
2899 "op=security_sid_mls_copy "
2900 "invalid_context=%s", s);
2901 kfree(s);
2902 }
2903 goto out_unlock;
2904 }
2905 }
2906
2907 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2908 out_unlock:
2909 read_unlock(&policy_rwlock);
2910 context_destroy(&newcon);
2911 out:
2912 return rc;
2913 }
2914
2915 /**
2916 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2917 * @nlbl_sid: NetLabel SID
2918 * @nlbl_type: NetLabel labeling protocol type
2919 * @xfrm_sid: XFRM SID
2920 *
2921 * Description:
2922 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2923 * resolved into a single SID it is returned via @peer_sid and the function
2924 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2925 * returns a negative value. A table summarizing the behavior is below:
2926 *
2927 * | function return | @sid
2928 * ------------------------------+-----------------+-----------------
2929 * no peer labels | 0 | SECSID_NULL
2930 * single peer label | 0 | <peer_label>
2931 * multiple, consistent labels | 0 | <peer_label>
2932 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2933 *
2934 */
2935 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2936 u32 xfrm_sid,
2937 u32 *peer_sid)
2938 {
2939 int rc;
2940 struct context *nlbl_ctx;
2941 struct context *xfrm_ctx;
2942
2943 *peer_sid = SECSID_NULL;
2944
2945 /* handle the common (which also happens to be the set of easy) cases
2946 * right away, these two if statements catch everything involving a
2947 * single or absent peer SID/label */
2948 if (xfrm_sid == SECSID_NULL) {
2949 *peer_sid = nlbl_sid;
2950 return 0;
2951 }
2952 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2953 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2954 * is present */
2955 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2956 *peer_sid = xfrm_sid;
2957 return 0;
2958 }
2959
2960 /* we don't need to check ss_initialized here since the only way both
2961 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2962 * security server was initialized and ss_initialized was true */
2963 if (!policydb.mls_enabled)
2964 return 0;
2965
2966 read_lock(&policy_rwlock);
2967
2968 rc = -EINVAL;
2969 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2970 if (!nlbl_ctx) {
2971 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2972 __func__, nlbl_sid);
2973 goto out;
2974 }
2975 rc = -EINVAL;
2976 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2977 if (!xfrm_ctx) {
2978 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2979 __func__, xfrm_sid);
2980 goto out;
2981 }
2982 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2983 if (rc)
2984 goto out;
2985
2986 /* at present NetLabel SIDs/labels really only carry MLS
2987 * information so if the MLS portion of the NetLabel SID
2988 * matches the MLS portion of the labeled XFRM SID/label
2989 * then pass along the XFRM SID as it is the most
2990 * expressive */
2991 *peer_sid = xfrm_sid;
2992 out:
2993 read_unlock(&policy_rwlock);
2994 return rc;
2995 }
2996
2997 static int get_classes_callback(void *k, void *d, void *args)
2998 {
2999 struct class_datum *datum = d;
3000 char *name = k, **classes = args;
3001 int value = datum->value - 1;
3002
3003 classes[value] = kstrdup(name, GFP_ATOMIC);
3004 if (!classes[value])
3005 return -ENOMEM;
3006
3007 return 0;
3008 }
3009
3010 int security_get_classes(char ***classes, int *nclasses)
3011 {
3012 int rc;
3013
3014 read_lock(&policy_rwlock);
3015
3016 rc = -ENOMEM;
3017 *nclasses = policydb.p_classes.nprim;
3018 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3019 if (!*classes)
3020 goto out;
3021
3022 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
3023 *classes);
3024 if (rc) {
3025 int i;
3026 for (i = 0; i < *nclasses; i++)
3027 kfree((*classes)[i]);
3028 kfree(*classes);
3029 }
3030
3031 out:
3032 read_unlock(&policy_rwlock);
3033 return rc;
3034 }
3035
3036 static int get_permissions_callback(void *k, void *d, void *args)
3037 {
3038 struct perm_datum *datum = d;
3039 char *name = k, **perms = args;
3040 int value = datum->value - 1;
3041
3042 perms[value] = kstrdup(name, GFP_ATOMIC);
3043 if (!perms[value])
3044 return -ENOMEM;
3045
3046 return 0;
3047 }
3048
3049 int security_get_permissions(char *class, char ***perms, int *nperms)
3050 {
3051 int rc, i;
3052 struct class_datum *match;
3053
3054 read_lock(&policy_rwlock);
3055
3056 rc = -EINVAL;
3057 match = hashtab_search(policydb.p_classes.table, class);
3058 if (!match) {
3059 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
3060 __func__, class);
3061 goto out;
3062 }
3063
3064 rc = -ENOMEM;
3065 *nperms = match->permissions.nprim;
3066 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3067 if (!*perms)
3068 goto out;
3069
3070 if (match->comdatum) {
3071 rc = hashtab_map(match->comdatum->permissions.table,
3072 get_permissions_callback, *perms);
3073 if (rc)
3074 goto err;
3075 }
3076
3077 rc = hashtab_map(match->permissions.table, get_permissions_callback,
3078 *perms);
3079 if (rc)
3080 goto err;
3081
3082 out:
3083 read_unlock(&policy_rwlock);
3084 return rc;
3085
3086 err:
3087 read_unlock(&policy_rwlock);
3088 for (i = 0; i < *nperms; i++)
3089 kfree((*perms)[i]);
3090 kfree(*perms);
3091 return rc;
3092 }
3093
3094 int security_get_reject_unknown(void)
3095 {
3096 return policydb.reject_unknown;
3097 }
3098
3099 int security_get_allow_unknown(void)
3100 {
3101 return policydb.allow_unknown;
3102 }
3103
3104 /**
3105 * security_policycap_supported - Check for a specific policy capability
3106 * @req_cap: capability
3107 *
3108 * Description:
3109 * This function queries the currently loaded policy to see if it supports the
3110 * capability specified by @req_cap. Returns true (1) if the capability is
3111 * supported, false (0) if it isn't supported.
3112 *
3113 */
3114 int security_policycap_supported(unsigned int req_cap)
3115 {
3116 int rc;
3117
3118 read_lock(&policy_rwlock);
3119 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3120 read_unlock(&policy_rwlock);
3121
3122 return rc;
3123 }
3124
3125 struct selinux_audit_rule {
3126 u32 au_seqno;
3127 struct context au_ctxt;
3128 };
3129
3130 void selinux_audit_rule_free(void *vrule)
3131 {
3132 struct selinux_audit_rule *rule = vrule;
3133
3134 if (rule) {
3135 context_destroy(&rule->au_ctxt);
3136 kfree(rule);
3137 }
3138 }
3139
3140 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3141 {
3142 struct selinux_audit_rule *tmprule;
3143 struct role_datum *roledatum;
3144 struct type_datum *typedatum;
3145 struct user_datum *userdatum;
3146 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3147 int rc = 0;
3148
3149 *rule = NULL;
3150
3151 if (!ss_initialized)
3152 return -EOPNOTSUPP;
3153
3154 switch (field) {
3155 case AUDIT_SUBJ_USER:
3156 case AUDIT_SUBJ_ROLE:
3157 case AUDIT_SUBJ_TYPE:
3158 case AUDIT_OBJ_USER:
3159 case AUDIT_OBJ_ROLE:
3160 case AUDIT_OBJ_TYPE:
3161 /* only 'equals' and 'not equals' fit user, role, and type */
3162 if (op != Audit_equal && op != Audit_not_equal)
3163 return -EINVAL;
3164 break;
3165 case AUDIT_SUBJ_SEN:
3166 case AUDIT_SUBJ_CLR:
3167 case AUDIT_OBJ_LEV_LOW:
3168 case AUDIT_OBJ_LEV_HIGH:
3169 /* we do not allow a range, indicated by the presence of '-' */
3170 if (strchr(rulestr, '-'))
3171 return -EINVAL;
3172 break;
3173 default:
3174 /* only the above fields are valid */
3175 return -EINVAL;
3176 }
3177
3178 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3179 if (!tmprule)
3180 return -ENOMEM;
3181
3182 context_init(&tmprule->au_ctxt);
3183
3184 read_lock(&policy_rwlock);
3185
3186 tmprule->au_seqno = latest_granting;
3187
3188 switch (field) {
3189 case AUDIT_SUBJ_USER:
3190 case AUDIT_OBJ_USER:
3191 rc = -EINVAL;
3192 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3193 if (!userdatum)
3194 goto out;
3195 tmprule->au_ctxt.user = userdatum->value;
3196 break;
3197 case AUDIT_SUBJ_ROLE:
3198 case AUDIT_OBJ_ROLE:
3199 rc = -EINVAL;
3200 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3201 if (!roledatum)
3202 goto out;
3203 tmprule->au_ctxt.role = roledatum->value;
3204 break;
3205 case AUDIT_SUBJ_TYPE:
3206 case AUDIT_OBJ_TYPE:
3207 rc = -EINVAL;
3208 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3209 if (!typedatum)
3210 goto out;
3211 tmprule->au_ctxt.type = typedatum->value;
3212 break;
3213 case AUDIT_SUBJ_SEN:
3214 case AUDIT_SUBJ_CLR:
3215 case AUDIT_OBJ_LEV_LOW:
3216 case AUDIT_OBJ_LEV_HIGH:
3217 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3218 if (rc)
3219 goto out;
3220 break;
3221 }
3222 rc = 0;
3223 out:
3224 read_unlock(&policy_rwlock);
3225
3226 if (rc) {
3227 selinux_audit_rule_free(tmprule);
3228 tmprule = NULL;
3229 }
3230
3231 *rule = tmprule;
3232
3233 return rc;
3234 }
3235
3236 /* Check to see if the rule contains any selinux fields */
3237 int selinux_audit_rule_known(struct audit_krule *rule)
3238 {
3239 int i;
3240
3241 for (i = 0; i < rule->field_count; i++) {
3242 struct audit_field *f = &rule->fields[i];
3243 switch (f->type) {
3244 case AUDIT_SUBJ_USER:
3245 case AUDIT_SUBJ_ROLE:
3246 case AUDIT_SUBJ_TYPE:
3247 case AUDIT_SUBJ_SEN:
3248 case AUDIT_SUBJ_CLR:
3249 case AUDIT_OBJ_USER:
3250 case AUDIT_OBJ_ROLE:
3251 case AUDIT_OBJ_TYPE:
3252 case AUDIT_OBJ_LEV_LOW:
3253 case AUDIT_OBJ_LEV_HIGH:
3254 return 1;
3255 }
3256 }
3257
3258 return 0;
3259 }
3260
3261 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3262 struct audit_context *actx)
3263 {
3264 struct context *ctxt;
3265 struct mls_level *level;
3266 struct selinux_audit_rule *rule = vrule;
3267 int match = 0;
3268
3269 if (unlikely(!rule)) {
3270 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3271 return -ENOENT;
3272 }
3273
3274 read_lock(&policy_rwlock);
3275
3276 if (rule->au_seqno < latest_granting) {
3277 match = -ESTALE;
3278 goto out;
3279 }
3280
3281 ctxt = sidtab_search(&sidtab, sid);
3282 if (unlikely(!ctxt)) {
3283 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3284 sid);
3285 match = -ENOENT;
3286 goto out;
3287 }
3288
3289 /* a field/op pair that is not caught here will simply fall through
3290 without a match */
3291 switch (field) {
3292 case AUDIT_SUBJ_USER:
3293 case AUDIT_OBJ_USER:
3294 switch (op) {
3295 case Audit_equal:
3296 match = (ctxt->user == rule->au_ctxt.user);
3297 break;
3298 case Audit_not_equal:
3299 match = (ctxt->user != rule->au_ctxt.user);
3300 break;
3301 }
3302 break;
3303 case AUDIT_SUBJ_ROLE:
3304 case AUDIT_OBJ_ROLE:
3305 switch (op) {
3306 case Audit_equal:
3307 match = (ctxt->role == rule->au_ctxt.role);
3308 break;
3309 case Audit_not_equal:
3310 match = (ctxt->role != rule->au_ctxt.role);
3311 break;
3312 }
3313 break;
3314 case AUDIT_SUBJ_TYPE:
3315 case AUDIT_OBJ_TYPE:
3316 switch (op) {
3317 case Audit_equal:
3318 match = (ctxt->type == rule->au_ctxt.type);
3319 break;
3320 case Audit_not_equal:
3321 match = (ctxt->type != rule->au_ctxt.type);
3322 break;
3323 }
3324 break;
3325 case AUDIT_SUBJ_SEN:
3326 case AUDIT_SUBJ_CLR:
3327 case AUDIT_OBJ_LEV_LOW:
3328 case AUDIT_OBJ_LEV_HIGH:
3329 level = ((field == AUDIT_SUBJ_SEN ||
3330 field == AUDIT_OBJ_LEV_LOW) ?
3331 &ctxt->range.level[0] : &ctxt->range.level[1]);
3332 switch (op) {
3333 case Audit_equal:
3334 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3335 level);
3336 break;
3337 case Audit_not_equal:
3338 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3339 level);
3340 break;
3341 case Audit_lt:
3342 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3343 level) &&
3344 !mls_level_eq(&rule->au_ctxt.range.level[0],
3345 level));
3346 break;
3347 case Audit_le:
3348 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3349 level);
3350 break;
3351 case Audit_gt:
3352 match = (mls_level_dom(level,
3353 &rule->au_ctxt.range.level[0]) &&
3354 !mls_level_eq(level,
3355 &rule->au_ctxt.range.level[0]));
3356 break;
3357 case Audit_ge:
3358 match = mls_level_dom(level,
3359 &rule->au_ctxt.range.level[0]);
3360 break;
3361 }
3362 }
3363
3364 out:
3365 read_unlock(&policy_rwlock);
3366 return match;
3367 }
3368
3369 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3370
3371 static int aurule_avc_callback(u32 event)
3372 {
3373 int err = 0;
3374
3375 if (event == AVC_CALLBACK_RESET && aurule_callback)
3376 err = aurule_callback();
3377 return err;
3378 }
3379
3380 static int __init aurule_init(void)
3381 {
3382 int err;
3383
3384 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3385 if (err)
3386 panic("avc_add_callback() failed, error %d\n", err);
3387
3388 return err;
3389 }
3390 __initcall(aurule_init);
3391
3392 #ifdef CONFIG_NETLABEL
3393 /**
3394 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3395 * @secattr: the NetLabel packet security attributes
3396 * @sid: the SELinux SID
3397 *
3398 * Description:
3399 * Attempt to cache the context in @ctx, which was derived from the packet in
3400 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3401 * already been initialized.
3402 *
3403 */
3404 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3405 u32 sid)
3406 {
3407 u32 *sid_cache;
3408
3409 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3410 if (sid_cache == NULL)
3411 return;
3412 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3413 if (secattr->cache == NULL) {
3414 kfree(sid_cache);
3415 return;
3416 }
3417
3418 *sid_cache = sid;
3419 secattr->cache->free = kfree;
3420 secattr->cache->data = sid_cache;
3421 secattr->flags |= NETLBL_SECATTR_CACHE;
3422 }
3423
3424 /**
3425 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3426 * @secattr: the NetLabel packet security attributes
3427 * @sid: the SELinux SID
3428 *
3429 * Description:
3430 * Convert the given NetLabel security attributes in @secattr into a
3431 * SELinux SID. If the @secattr field does not contain a full SELinux
3432 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3433 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3434 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3435 * conversion for future lookups. Returns zero on success, negative values on
3436 * failure.
3437 *
3438 */
3439 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3440 u32 *sid)
3441 {
3442 int rc;
3443 struct context *ctx;
3444 struct context ctx_new;
3445
3446 if (!ss_initialized) {
3447 *sid = SECSID_NULL;
3448 return 0;
3449 }
3450
3451 read_lock(&policy_rwlock);
3452
3453 if (secattr->flags & NETLBL_SECATTR_CACHE)
3454 *sid = *(u32 *)secattr->cache->data;
3455 else if (secattr->flags & NETLBL_SECATTR_SECID)
3456 *sid = secattr->attr.secid;
3457 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3458 rc = -EIDRM;
3459 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3460 if (ctx == NULL)
3461 goto out;
3462
3463 context_init(&ctx_new);
3464 ctx_new.user = ctx->user;
3465 ctx_new.role = ctx->role;
3466 ctx_new.type = ctx->type;
3467 mls_import_netlbl_lvl(&ctx_new, secattr);
3468 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3469 rc = mls_import_netlbl_cat(&ctx_new, secattr);
3470 if (rc)
3471 goto out;
3472 }
3473 rc = -EIDRM;
3474 if (!mls_context_isvalid(&policydb, &ctx_new))
3475 goto out_free;
3476
3477 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3478 if (rc)
3479 goto out_free;
3480
3481 security_netlbl_cache_add(secattr, *sid);
3482
3483 ebitmap_destroy(&ctx_new.range.level[0].cat);
3484 } else
3485 *sid = SECSID_NULL;
3486
3487 read_unlock(&policy_rwlock);
3488 return 0;
3489 out_free:
3490 ebitmap_destroy(&ctx_new.range.level[0].cat);
3491 out:
3492 read_unlock(&policy_rwlock);
3493 return rc;
3494 }
3495
3496 /**
3497 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3498 * @sid: the SELinux SID
3499 * @secattr: the NetLabel packet security attributes
3500 *
3501 * Description:
3502 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3503 * Returns zero on success, negative values on failure.
3504 *
3505 */
3506 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3507 {
3508 int rc;
3509 struct context *ctx;
3510
3511 if (!ss_initialized)
3512 return 0;
3513
3514 read_lock(&policy_rwlock);
3515
3516 rc = -ENOENT;
3517 ctx = sidtab_search(&sidtab, sid);
3518 if (ctx == NULL)
3519 goto out;
3520
3521 rc = -ENOMEM;
3522 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3523 GFP_ATOMIC);
3524 if (secattr->domain == NULL)
3525 goto out;
3526
3527 secattr->attr.secid = sid;
3528 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3529 mls_export_netlbl_lvl(ctx, secattr);
3530 rc = mls_export_netlbl_cat(ctx, secattr);
3531 out:
3532 read_unlock(&policy_rwlock);
3533 return rc;
3534 }
3535 #endif /* CONFIG_NETLABEL */
3536
3537 /**
3538 * security_read_policy - read the policy.
3539 * @data: binary policy data
3540 * @len: length of data in bytes
3541 *
3542 */
3543 int security_read_policy(void **data, size_t *len)
3544 {
3545 int rc;
3546 struct policy_file fp;
3547
3548 if (!ss_initialized)
3549 return -EINVAL;
3550
3551 *len = security_policydb_len();
3552
3553 *data = vmalloc_user(*len);
3554 if (!*data)
3555 return -ENOMEM;
3556
3557 fp.data = *data;
3558 fp.len = *len;
3559
3560 read_lock(&policy_rwlock);
3561 rc = policydb_write(&policydb, &fp);
3562 read_unlock(&policy_rwlock);
3563
3564 if (rc)
3565 return rc;
3566
3567 *len = (unsigned long)fp.data - (unsigned long)*data;
3568 return 0;
3569
3570 }
Linux with added FPC-III support