1 /*
2 * Implementation of the security services.
3 *
4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5 * James Morris <jmorris@redhat.com>
6 *
7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8 *
9 * Support for enhanced MLS infrastructure.
10 * Support for context based audit filters.
11 *
12 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13 *
14 * Added conditional policy language extensions
15 *
16 * Updated: Hewlett-Packard <paul.moore@hp.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 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
26 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
27 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
28 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
29 * This program is free software; you can redistribute it and/or modify
30 * it under the terms of the GNU General Public License as published by
31 * the Free Software Foundation, version 2.
32 */
33 #include <linux/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/string.h>
36 #include <linux/spinlock.h>
37 #include <linux/rcupdate.h>
38 #include <linux/errno.h>
39 #include <linux/in.h>
40 #include <linux/sched.h>
41 #include <linux/audit.h>
42 #include <linux/mutex.h>
43 #include <linux/selinux.h>
44 #include <net/netlabel.h>
45
46 #include "flask.h"
47 #include "avc.h"
48 #include "avc_ss.h"
49 #include "security.h"
50 #include "context.h"
51 #include "policydb.h"
52 #include "sidtab.h"
53 #include "services.h"
54 #include "conditional.h"
55 #include "mls.h"
56 #include "objsec.h"
57 #include "netlabel.h"
58 #include "xfrm.h"
59 #include "ebitmap.h"
60 #include "audit.h"
61
62 extern void selnl_notify_policyload(u32 seqno);
63 unsigned int policydb_loaded_version;
64
65 int selinux_policycap_netpeer;
66 int selinux_policycap_openperm;
67
68 /*
69 * This is declared in avc.c
70 */
71 extern const struct selinux_class_perm selinux_class_perm;
72
73 static DEFINE_RWLOCK(policy_rwlock);
74
75 static struct sidtab sidtab;
76 struct policydb policydb;
77 int ss_initialized;
78
79 /*
80 * The largest sequence number that has been used when
81 * providing an access decision to the access vector cache.
82 * The sequence number only changes when a policy change
83 * occurs.
84 */
85 static u32 latest_granting;
86
87 /* Forward declaration. */
88 static int context_struct_to_string(struct context *context, char **scontext,
89 u32 *scontext_len);
90
91 static int context_struct_compute_av(struct context *scontext,
92 struct context *tcontext,
93 u16 tclass,
94 u32 requested,
95 struct av_decision *avd);
96 /*
97 * Return the boolean value of a constraint expression
98 * when it is applied to the specified source and target
99 * security contexts.
100 *
101 * xcontext is a special beast... It is used by the validatetrans rules
102 * only. For these rules, scontext is the context before the transition,
103 * tcontext is the context after the transition, and xcontext is the context
104 * of the process performing the transition. All other callers of
105 * constraint_expr_eval should pass in NULL for xcontext.
106 */
constraint_expr_eval(struct context * scontext,struct context * tcontext,struct context * xcontext,struct constraint_expr * cexpr)107 static int constraint_expr_eval(struct context *scontext,
108 struct context *tcontext,
109 struct context *xcontext,
110 struct constraint_expr *cexpr)
111 {
112 u32 val1, val2;
113 struct context *c;
114 struct role_datum *r1, *r2;
115 struct mls_level *l1, *l2;
116 struct constraint_expr *e;
117 int s[CEXPR_MAXDEPTH];
118 int sp = -1;
119
120 for (e = cexpr; e; e = e->next) {
121 switch (e->expr_type) {
122 case CEXPR_NOT:
123 BUG_ON(sp < 0);
124 s[sp] = !s[sp];
125 break;
126 case CEXPR_AND:
127 BUG_ON(sp < 1);
128 sp--;
129 s[sp] &= s[sp+1];
130 break;
131 case CEXPR_OR:
132 BUG_ON(sp < 1);
133 sp--;
134 s[sp] |= s[sp+1];
135 break;
136 case CEXPR_ATTR:
137 if (sp == (CEXPR_MAXDEPTH-1))
138 return 0;
139 switch (e->attr) {
140 case CEXPR_USER:
141 val1 = scontext->user;
142 val2 = tcontext->user;
143 break;
144 case CEXPR_TYPE:
145 val1 = scontext->type;
146 val2 = tcontext->type;
147 break;
148 case CEXPR_ROLE:
149 val1 = scontext->role;
150 val2 = tcontext->role;
151 r1 = policydb.role_val_to_struct[val1 - 1];
152 r2 = policydb.role_val_to_struct[val2 - 1];
153 switch (e->op) {
154 case CEXPR_DOM:
155 s[++sp] = ebitmap_get_bit(&r1->dominates,
156 val2 - 1);
157 continue;
158 case CEXPR_DOMBY:
159 s[++sp] = ebitmap_get_bit(&r2->dominates,
160 val1 - 1);
161 continue;
162 case CEXPR_INCOMP:
163 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
164 val2 - 1) &&
165 !ebitmap_get_bit(&r2->dominates,
166 val1 - 1));
167 continue;
168 default:
169 break;
170 }
171 break;
172 case CEXPR_L1L2:
173 l1 = &(scontext->range.level[0]);
174 l2 = &(tcontext->range.level[0]);
175 goto mls_ops;
176 case CEXPR_L1H2:
177 l1 = &(scontext->range.level[0]);
178 l2 = &(tcontext->range.level[1]);
179 goto mls_ops;
180 case CEXPR_H1L2:
181 l1 = &(scontext->range.level[1]);
182 l2 = &(tcontext->range.level[0]);
183 goto mls_ops;
184 case CEXPR_H1H2:
185 l1 = &(scontext->range.level[1]);
186 l2 = &(tcontext->range.level[1]);
187 goto mls_ops;
188 case CEXPR_L1H1:
189 l1 = &(scontext->range.level[0]);
190 l2 = &(scontext->range.level[1]);
191 goto mls_ops;
192 case CEXPR_L2H2:
193 l1 = &(tcontext->range.level[0]);
194 l2 = &(tcontext->range.level[1]);
195 goto mls_ops;
196 mls_ops:
197 switch (e->op) {
198 case CEXPR_EQ:
199 s[++sp] = mls_level_eq(l1, l2);
200 continue;
201 case CEXPR_NEQ:
202 s[++sp] = !mls_level_eq(l1, l2);
203 continue;
204 case CEXPR_DOM:
205 s[++sp] = mls_level_dom(l1, l2);
206 continue;
207 case CEXPR_DOMBY:
208 s[++sp] = mls_level_dom(l2, l1);
209 continue;
210 case CEXPR_INCOMP:
211 s[++sp] = mls_level_incomp(l2, l1);
212 continue;
213 default:
214 BUG();
215 return 0;
216 }
217 break;
218 default:
219 BUG();
220 return 0;
221 }
222
223 switch (e->op) {
224 case CEXPR_EQ:
225 s[++sp] = (val1 == val2);
226 break;
227 case CEXPR_NEQ:
228 s[++sp] = (val1 != val2);
229 break;
230 default:
231 BUG();
232 return 0;
233 }
234 break;
235 case CEXPR_NAMES:
236 if (sp == (CEXPR_MAXDEPTH-1))
237 return 0;
238 c = scontext;
239 if (e->attr & CEXPR_TARGET)
240 c = tcontext;
241 else if (e->attr & CEXPR_XTARGET) {
242 c = xcontext;
243 if (!c) {
244 BUG();
245 return 0;
246 }
247 }
248 if (e->attr & CEXPR_USER)
249 val1 = c->user;
250 else if (e->attr & CEXPR_ROLE)
251 val1 = c->role;
252 else if (e->attr & CEXPR_TYPE)
253 val1 = c->type;
254 else {
255 BUG();
256 return 0;
257 }
258
259 switch (e->op) {
260 case CEXPR_EQ:
261 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
262 break;
263 case CEXPR_NEQ:
264 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
265 break;
266 default:
267 BUG();
268 return 0;
269 }
270 break;
271 default:
272 BUG();
273 return 0;
274 }
275 }
276
277 BUG_ON(sp != 0);
278 return s[0];
279 }
280
281 /*
282 * security_boundary_permission - drops violated permissions
283 * on boundary constraint.
284 */
type_attribute_bounds_av(struct context * scontext,struct context * tcontext,u16 tclass,u32 requested,struct av_decision * avd)285 static void type_attribute_bounds_av(struct context *scontext,
286 struct context *tcontext,
287 u16 tclass,
288 u32 requested,
289 struct av_decision *avd)
290 {
291 struct context lo_scontext;
292 struct context lo_tcontext;
293 struct av_decision lo_avd;
294 struct type_datum *source
295 = policydb.type_val_to_struct[scontext->type - 1];
296 struct type_datum *target
297 = policydb.type_val_to_struct[tcontext->type - 1];
298 u32 masked = 0;
299
300 if (source->bounds) {
301 memset(&lo_avd, 0, sizeof(lo_avd));
302
303 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
304 lo_scontext.type = source->bounds;
305
306 context_struct_compute_av(&lo_scontext,
307 tcontext,
308 tclass,
309 requested,
310 &lo_avd);
311 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
312 return; /* no masked permission */
313 masked = ~lo_avd.allowed & avd->allowed;
314 }
315
316 if (target->bounds) {
317 memset(&lo_avd, 0, sizeof(lo_avd));
318
319 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
320 lo_tcontext.type = target->bounds;
321
322 context_struct_compute_av(scontext,
323 &lo_tcontext,
324 tclass,
325 requested,
326 &lo_avd);
327 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
328 return; /* no masked permission */
329 masked = ~lo_avd.allowed & avd->allowed;
330 }
331
332 if (source->bounds && target->bounds) {
333 memset(&lo_avd, 0, sizeof(lo_avd));
334 /*
335 * lo_scontext and lo_tcontext are already
336 * set up.
337 */
338
339 context_struct_compute_av(&lo_scontext,
340 &lo_tcontext,
341 tclass,
342 requested,
343 &lo_avd);
344 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
345 return; /* no masked permission */
346 masked = ~lo_avd.allowed & avd->allowed;
347 }
348
349 if (masked) {
350 struct audit_buffer *ab;
351 char *stype_name
352 = policydb.p_type_val_to_name[source->value - 1];
353 char *ttype_name
354 = policydb.p_type_val_to_name[target->value - 1];
355 char *tclass_name
356 = policydb.p_class_val_to_name[tclass - 1];
357
358 /* mask violated permissions */
359 avd->allowed &= ~masked;
360
361 /* notice to userspace via audit message */
362 ab = audit_log_start(current->audit_context,
363 GFP_ATOMIC, AUDIT_SELINUX_ERR);
364 if (!ab)
365 return;
366
367 audit_log_format(ab, "av boundary violation: "
368 "source=%s target=%s tclass=%s",
369 stype_name, ttype_name, tclass_name);
370 avc_dump_av(ab, tclass, masked);
371 audit_log_end(ab);
372 }
373 }
374
375 /*
376 * Compute access vectors based on a context structure pair for
377 * the permissions in a particular class.
378 */
context_struct_compute_av(struct context * scontext,struct context * tcontext,u16 tclass,u32 requested,struct av_decision * avd)379 static int context_struct_compute_av(struct context *scontext,
380 struct context *tcontext,
381 u16 tclass,
382 u32 requested,
383 struct av_decision *avd)
384 {
385 struct constraint_node *constraint;
386 struct role_allow *ra;
387 struct avtab_key avkey;
388 struct avtab_node *node;
389 struct class_datum *tclass_datum;
390 struct ebitmap *sattr, *tattr;
391 struct ebitmap_node *snode, *tnode;
392 const struct selinux_class_perm *kdefs = &selinux_class_perm;
393 unsigned int i, j;
394
395 /*
396 * Remap extended Netlink classes for old policy versions.
397 * Do this here rather than socket_type_to_security_class()
398 * in case a newer policy version is loaded, allowing sockets
399 * to remain in the correct class.
400 */
401 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
402 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
403 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
404 tclass = SECCLASS_NETLINK_SOCKET;
405
406 /*
407 * Initialize the access vectors to the default values.
408 */
409 avd->allowed = 0;
410 avd->decided = 0xffffffff;
411 avd->auditallow = 0;
412 avd->auditdeny = 0xffffffff;
413 avd->seqno = latest_granting;
414
415 /*
416 * Check for all the invalid cases.
417 * - tclass 0
418 * - tclass > policy and > kernel
419 * - tclass > policy but is a userspace class
420 * - tclass > policy but we do not allow unknowns
421 */
422 if (unlikely(!tclass))
423 goto inval_class;
424 if (unlikely(tclass > policydb.p_classes.nprim))
425 if (tclass > kdefs->cts_len ||
426 !kdefs->class_to_string[tclass] ||
427 !policydb.allow_unknown)
428 goto inval_class;
429
430 /*
431 * Kernel class and we allow unknown so pad the allow decision
432 * the pad will be all 1 for unknown classes.
433 */
434 if (tclass <= kdefs->cts_len && policydb.allow_unknown)
435 avd->allowed = policydb.undefined_perms[tclass - 1];
436
437 /*
438 * Not in policy. Since decision is completed (all 1 or all 0) return.
439 */
440 if (unlikely(tclass > policydb.p_classes.nprim))
441 return 0;
442
443 tclass_datum = policydb.class_val_to_struct[tclass - 1];
444
445 /*
446 * If a specific type enforcement rule was defined for
447 * this permission check, then use it.
448 */
449 avkey.target_class = tclass;
450 avkey.specified = AVTAB_AV;
451 sattr = &policydb.type_attr_map[scontext->type - 1];
452 tattr = &policydb.type_attr_map[tcontext->type - 1];
453 ebitmap_for_each_positive_bit(sattr, snode, i) {
454 ebitmap_for_each_positive_bit(tattr, tnode, j) {
455 avkey.source_type = i + 1;
456 avkey.target_type = j + 1;
457 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
458 node;
459 node = avtab_search_node_next(node, avkey.specified)) {
460 if (node->key.specified == AVTAB_ALLOWED)
461 avd->allowed |= node->datum.data;
462 else if (node->key.specified == AVTAB_AUDITALLOW)
463 avd->auditallow |= node->datum.data;
464 else if (node->key.specified == AVTAB_AUDITDENY)
465 avd->auditdeny &= node->datum.data;
466 }
467
468 /* Check conditional av table for additional permissions */
469 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
470
471 }
472 }
473
474 /*
475 * Remove any permissions prohibited by a constraint (this includes
476 * the MLS policy).
477 */
478 constraint = tclass_datum->constraints;
479 while (constraint) {
480 if ((constraint->permissions & (avd->allowed)) &&
481 !constraint_expr_eval(scontext, tcontext, NULL,
482 constraint->expr)) {
483 avd->allowed = (avd->allowed) & ~(constraint->permissions);
484 }
485 constraint = constraint->next;
486 }
487
488 /*
489 * If checking process transition permission and the
490 * role is changing, then check the (current_role, new_role)
491 * pair.
492 */
493 if (tclass == SECCLASS_PROCESS &&
494 (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
495 scontext->role != tcontext->role) {
496 for (ra = policydb.role_allow; ra; ra = ra->next) {
497 if (scontext->role == ra->role &&
498 tcontext->role == ra->new_role)
499 break;
500 }
501 if (!ra)
502 avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
503 PROCESS__DYNTRANSITION);
504 }
505
506 /*
507 * If the given source and target types have boundary
508 * constraint, lazy checks have to mask any violated
509 * permission and notice it to userspace via audit.
510 */
511 type_attribute_bounds_av(scontext, tcontext,
512 tclass, requested, avd);
513
514 return 0;
515
516 inval_class:
517 if (!tclass || tclass > kdefs->cts_len ||
518 !kdefs->class_to_string[tclass]) {
519 if (printk_ratelimit())
520 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
521 __func__, tclass);
522 return -EINVAL;
523 }
524
525 /*
526 * Known to the kernel, but not to the policy.
527 * Handle as a denial (allowed is 0).
528 */
529 return 0;
530 }
531
532 /*
533 * Given a sid find if the type has the permissive flag set
534 */
security_permissive_sid(u32 sid)535 int security_permissive_sid(u32 sid)
536 {
537 struct context *context;
538 u32 type;
539 int rc;
540
541 read_lock(&policy_rwlock);
542
543 context = sidtab_search(&sidtab, sid);
544 BUG_ON(!context);
545
546 type = context->type;
547 /*
548 * we are intentionally using type here, not type-1, the 0th bit may
549 * someday indicate that we are globally setting permissive in policy.
550 */
551 rc = ebitmap_get_bit(&policydb.permissive_map, type);
552
553 read_unlock(&policy_rwlock);
554 return rc;
555 }
556
security_validtrans_handle_fail(struct context * ocontext,struct context * ncontext,struct context * tcontext,u16 tclass)557 static int security_validtrans_handle_fail(struct context *ocontext,
558 struct context *ncontext,
559 struct context *tcontext,
560 u16 tclass)
561 {
562 char *o = NULL, *n = NULL, *t = NULL;
563 u32 olen, nlen, tlen;
564
565 if (context_struct_to_string(ocontext, &o, &olen) < 0)
566 goto out;
567 if (context_struct_to_string(ncontext, &n, &nlen) < 0)
568 goto out;
569 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
570 goto out;
571 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
572 "security_validate_transition: denied for"
573 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
574 o, n, t, policydb.p_class_val_to_name[tclass-1]);
575 out:
576 kfree(o);
577 kfree(n);
578 kfree(t);
579
580 if (!selinux_enforcing)
581 return 0;
582 return -EPERM;
583 }
584
security_validate_transition(u32 oldsid,u32 newsid,u32 tasksid,u16 tclass)585 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
586 u16 tclass)
587 {
588 struct context *ocontext;
589 struct context *ncontext;
590 struct context *tcontext;
591 struct class_datum *tclass_datum;
592 struct constraint_node *constraint;
593 int rc = 0;
594
595 if (!ss_initialized)
596 return 0;
597
598 read_lock(&policy_rwlock);
599
600 /*
601 * Remap extended Netlink classes for old policy versions.
602 * Do this here rather than socket_type_to_security_class()
603 * in case a newer policy version is loaded, allowing sockets
604 * to remain in the correct class.
605 */
606 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
607 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
608 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
609 tclass = SECCLASS_NETLINK_SOCKET;
610
611 if (!tclass || tclass > policydb.p_classes.nprim) {
612 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
613 __func__, tclass);
614 rc = -EINVAL;
615 goto out;
616 }
617 tclass_datum = policydb.class_val_to_struct[tclass - 1];
618
619 ocontext = sidtab_search(&sidtab, oldsid);
620 if (!ocontext) {
621 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
622 __func__, oldsid);
623 rc = -EINVAL;
624 goto out;
625 }
626
627 ncontext = sidtab_search(&sidtab, newsid);
628 if (!ncontext) {
629 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
630 __func__, newsid);
631 rc = -EINVAL;
632 goto out;
633 }
634
635 tcontext = sidtab_search(&sidtab, tasksid);
636 if (!tcontext) {
637 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
638 __func__, tasksid);
639 rc = -EINVAL;
640 goto out;
641 }
642
643 constraint = tclass_datum->validatetrans;
644 while (constraint) {
645 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
646 constraint->expr)) {
647 rc = security_validtrans_handle_fail(ocontext, ncontext,
648 tcontext, tclass);
649 goto out;
650 }
651 constraint = constraint->next;
652 }
653
654 out:
655 read_unlock(&policy_rwlock);
656 return rc;
657 }
658
659 /*
660 * security_bounded_transition - check whether the given
661 * transition is directed to bounded, or not.
662 * It returns 0, if @newsid is bounded by @oldsid.
663 * Otherwise, it returns error code.
664 *
665 * @oldsid : current security identifier
666 * @newsid : destinated security identifier
667 */
security_bounded_transition(u32 old_sid,u32 new_sid)668 int security_bounded_transition(u32 old_sid, u32 new_sid)
669 {
670 struct context *old_context, *new_context;
671 struct type_datum *type;
672 int index;
673 int rc = -EINVAL;
674
675 read_lock(&policy_rwlock);
676
677 old_context = sidtab_search(&sidtab, old_sid);
678 if (!old_context) {
679 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
680 __func__, old_sid);
681 goto out;
682 }
683
684 new_context = sidtab_search(&sidtab, new_sid);
685 if (!new_context) {
686 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
687 __func__, new_sid);
688 goto out;
689 }
690
691 /* type/domain unchaned */
692 if (old_context->type == new_context->type) {
693 rc = 0;
694 goto out;
695 }
696
697 index = new_context->type;
698 while (true) {
699 type = policydb.type_val_to_struct[index - 1];
700 BUG_ON(!type);
701
702 /* not bounded anymore */
703 if (!type->bounds) {
704 rc = -EPERM;
705 break;
706 }
707
708 /* @newsid is bounded by @oldsid */
709 if (type->bounds == old_context->type) {
710 rc = 0;
711 break;
712 }
713 index = type->bounds;
714 }
715 out:
716 read_unlock(&policy_rwlock);
717
718 return rc;
719 }
720
721
722 /**
723 * security_compute_av - Compute access vector decisions.
724 * @ssid: source security identifier
725 * @tsid: target security identifier
726 * @tclass: target security class
727 * @requested: requested permissions
728 * @avd: access vector decisions
729 *
730 * Compute a set of access vector decisions based on the
731 * SID pair (@ssid, @tsid) for the permissions in @tclass.
732 * Return -%EINVAL if any of the parameters are invalid or %0
733 * if the access vector decisions were computed successfully.
734 */
security_compute_av(u32 ssid,u32 tsid,u16 tclass,u32 requested,struct av_decision * avd)735 int security_compute_av(u32 ssid,
736 u32 tsid,
737 u16 tclass,
738 u32 requested,
739 struct av_decision *avd)
740 {
741 struct context *scontext = NULL, *tcontext = NULL;
742 int rc = 0;
743
744 if (!ss_initialized) {
745 avd->allowed = 0xffffffff;
746 avd->decided = 0xffffffff;
747 avd->auditallow = 0;
748 avd->auditdeny = 0xffffffff;
749 avd->seqno = latest_granting;
750 return 0;
751 }
752
753 read_lock(&policy_rwlock);
754
755 scontext = sidtab_search(&sidtab, ssid);
756 if (!scontext) {
757 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
758 __func__, ssid);
759 rc = -EINVAL;
760 goto out;
761 }
762 tcontext = sidtab_search(&sidtab, tsid);
763 if (!tcontext) {
764 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
765 __func__, tsid);
766 rc = -EINVAL;
767 goto out;
768 }
769
770 rc = context_struct_compute_av(scontext, tcontext, tclass,
771 requested, avd);
772 out:
773 read_unlock(&policy_rwlock);
774 return rc;
775 }
776
777 /*
778 * Write the security context string representation of
779 * the context structure `context' into a dynamically
780 * allocated string of the correct size. Set `*scontext'
781 * to point to this string and set `*scontext_len' to
782 * the length of the string.
783 */
context_struct_to_string(struct context * context,char ** scontext,u32 * scontext_len)784 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
785 {
786 char *scontextp;
787
788 *scontext = NULL;
789 *scontext_len = 0;
790
791 if (context->len) {
792 *scontext_len = context->len;
793 *scontext = kstrdup(context->str, GFP_ATOMIC);
794 if (!(*scontext))
795 return -ENOMEM;
796 return 0;
797 }
798
799 /* Compute the size of the context. */
800 *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
801 *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
802 *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
803 *scontext_len += mls_compute_context_len(context);
804
805 /* Allocate space for the context; caller must free this space. */
806 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
807 if (!scontextp)
808 return -ENOMEM;
809 *scontext = scontextp;
810
811 /*
812 * Copy the user name, role name and type name into the context.
813 */
814 sprintf(scontextp, "%s:%s:%s",
815 policydb.p_user_val_to_name[context->user - 1],
816 policydb.p_role_val_to_name[context->role - 1],
817 policydb.p_type_val_to_name[context->type - 1]);
818 scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
819 1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
820 1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
821
822 mls_sid_to_context(context, &scontextp);
823
824 *scontextp = 0;
825
826 return 0;
827 }
828
829 #include "initial_sid_to_string.h"
830
security_get_initial_sid_context(u32 sid)831 const char *security_get_initial_sid_context(u32 sid)
832 {
833 if (unlikely(sid > SECINITSID_NUM))
834 return NULL;
835 return initial_sid_to_string[sid];
836 }
837
security_sid_to_context_core(u32 sid,char ** scontext,u32 * scontext_len,int force)838 static int security_sid_to_context_core(u32 sid, char **scontext,
839 u32 *scontext_len, int force)
840 {
841 struct context *context;
842 int rc = 0;
843
844 *scontext = NULL;
845 *scontext_len = 0;
846
847 if (!ss_initialized) {
848 if (sid <= SECINITSID_NUM) {
849 char *scontextp;
850
851 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
852 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
853 if (!scontextp) {
854 rc = -ENOMEM;
855 goto out;
856 }
857 strcpy(scontextp, initial_sid_to_string[sid]);
858 *scontext = scontextp;
859 goto out;
860 }
861 printk(KERN_ERR "SELinux: %s: called before initial "
862 "load_policy on unknown SID %d\n", __func__, sid);
863 rc = -EINVAL;
864 goto out;
865 }
866 read_lock(&policy_rwlock);
867 if (force)
868 context = sidtab_search_force(&sidtab, sid);
869 else
870 context = sidtab_search(&sidtab, sid);
871 if (!context) {
872 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
873 __func__, sid);
874 rc = -EINVAL;
875 goto out_unlock;
876 }
877 rc = context_struct_to_string(context, scontext, scontext_len);
878 out_unlock:
879 read_unlock(&policy_rwlock);
880 out:
881 return rc;
882
883 }
884
885 /**
886 * security_sid_to_context - Obtain a context for a given SID.
887 * @sid: security identifier, SID
888 * @scontext: security context
889 * @scontext_len: length in bytes
890 *
891 * Write the string representation of the context associated with @sid
892 * into a dynamically allocated string of the correct size. Set @scontext
893 * to point to this string and set @scontext_len to the length of the string.
894 */
security_sid_to_context(u32 sid,char ** scontext,u32 * scontext_len)895 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
896 {
897 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
898 }
899
security_sid_to_context_force(u32 sid,char ** scontext,u32 * scontext_len)900 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
901 {
902 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
903 }
904
905 /*
906 * Caveat: Mutates scontext.
907 */
string_to_context_struct(struct policydb * pol,struct sidtab * sidtabp,char * scontext,u32 scontext_len,struct context * ctx,u32 def_sid)908 static int string_to_context_struct(struct policydb *pol,
909 struct sidtab *sidtabp,
910 char *scontext,
911 u32 scontext_len,
912 struct context *ctx,
913 u32 def_sid)
914 {
915 struct role_datum *role;
916 struct type_datum *typdatum;
917 struct user_datum *usrdatum;
918 char *scontextp, *p, oldc;
919 int rc = 0;
920
921 context_init(ctx);
922
923 /* Parse the security context. */
924
925 rc = -EINVAL;
926 scontextp = (char *) scontext;
927
928 /* Extract the user. */
929 p = scontextp;
930 while (*p && *p != ':')
931 p++;
932
933 if (*p == 0)
934 goto out;
935
936 *p++ = 0;
937
938 usrdatum = hashtab_search(pol->p_users.table, scontextp);
939 if (!usrdatum)
940 goto out;
941
942 ctx->user = usrdatum->value;
943
944 /* Extract role. */
945 scontextp = p;
946 while (*p && *p != ':')
947 p++;
948
949 if (*p == 0)
950 goto out;
951
952 *p++ = 0;
953
954 role = hashtab_search(pol->p_roles.table, scontextp);
955 if (!role)
956 goto out;
957 ctx->role = role->value;
958
959 /* Extract type. */
960 scontextp = p;
961 while (*p && *p != ':')
962 p++;
963 oldc = *p;
964 *p++ = 0;
965
966 typdatum = hashtab_search(pol->p_types.table, scontextp);
967 if (!typdatum || typdatum->attribute)
968 goto out;
969
970 ctx->type = typdatum->value;
971
972 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
973 if (rc)
974 goto out;
975
976 if ((p - scontext) < scontext_len) {
977 rc = -EINVAL;
978 goto out;
979 }
980
981 /* Check the validity of the new context. */
982 if (!policydb_context_isvalid(pol, ctx)) {
983 rc = -EINVAL;
984 goto out;
985 }
986 rc = 0;
987 out:
988 if (rc)
989 context_destroy(ctx);
990 return rc;
991 }
992
security_context_to_sid_core(const char * scontext,u32 scontext_len,u32 * sid,u32 def_sid,gfp_t gfp_flags,int force)993 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
994 u32 *sid, u32 def_sid, gfp_t gfp_flags,
995 int force)
996 {
997 char *scontext2, *str = NULL;
998 struct context context;
999 int rc = 0;
1000
1001 if (!ss_initialized) {
1002 int i;
1003
1004 for (i = 1; i < SECINITSID_NUM; i++) {
1005 if (!strcmp(initial_sid_to_string[i], scontext)) {
1006 *sid = i;
1007 return 0;
1008 }
1009 }
1010 *sid = SECINITSID_KERNEL;
1011 return 0;
1012 }
1013 *sid = SECSID_NULL;
1014
1015 /* Copy the string so that we can modify the copy as we parse it. */
1016 scontext2 = kmalloc(scontext_len+1, gfp_flags);
1017 if (!scontext2)
1018 return -ENOMEM;
1019 memcpy(scontext2, scontext, scontext_len);
1020 scontext2[scontext_len] = 0;
1021
1022 if (force) {
1023 /* Save another copy for storing in uninterpreted form */
1024 str = kstrdup(scontext2, gfp_flags);
1025 if (!str) {
1026 kfree(scontext2);
1027 return -ENOMEM;
1028 }
1029 }
1030
1031 read_lock(&policy_rwlock);
1032 rc = string_to_context_struct(&policydb, &sidtab,
1033 scontext2, scontext_len,
1034 &context, def_sid);
1035 if (rc == -EINVAL && force) {
1036 context.str = str;
1037 context.len = scontext_len;
1038 str = NULL;
1039 } else if (rc)
1040 goto out;
1041 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1042 context_destroy(&context);
1043 out:
1044 read_unlock(&policy_rwlock);
1045 kfree(scontext2);
1046 kfree(str);
1047 return rc;
1048 }
1049
1050 /**
1051 * security_context_to_sid - Obtain a SID for a given security context.
1052 * @scontext: security context
1053 * @scontext_len: length in bytes
1054 * @sid: security identifier, SID
1055 *
1056 * Obtains a SID associated with the security context that
1057 * has the string representation specified by @scontext.
1058 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1059 * memory is available, or 0 on success.
1060 */
security_context_to_sid(const char * scontext,u32 scontext_len,u32 * sid)1061 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1062 {
1063 return security_context_to_sid_core(scontext, scontext_len,
1064 sid, SECSID_NULL, GFP_KERNEL, 0);
1065 }
1066
1067 /**
1068 * security_context_to_sid_default - Obtain a SID for a given security context,
1069 * falling back to specified default if needed.
1070 *
1071 * @scontext: security context
1072 * @scontext_len: length in bytes
1073 * @sid: security identifier, SID
1074 * @def_sid: default SID to assign on error
1075 *
1076 * Obtains a SID associated with the security context that
1077 * has the string representation specified by @scontext.
1078 * The default SID is passed to the MLS layer to be used to allow
1079 * kernel labeling of the MLS field if the MLS field is not present
1080 * (for upgrading to MLS without full relabel).
1081 * Implicitly forces adding of the context even if it cannot be mapped yet.
1082 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1083 * memory is available, or 0 on success.
1084 */
security_context_to_sid_default(const char * scontext,u32 scontext_len,u32 * sid,u32 def_sid,gfp_t gfp_flags)1085 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1086 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1087 {
1088 return security_context_to_sid_core(scontext, scontext_len,
1089 sid, def_sid, gfp_flags, 1);
1090 }
1091
security_context_to_sid_force(const char * scontext,u32 scontext_len,u32 * sid)1092 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1093 u32 *sid)
1094 {
1095 return security_context_to_sid_core(scontext, scontext_len,
1096 sid, SECSID_NULL, GFP_KERNEL, 1);
1097 }
1098
compute_sid_handle_invalid_context(struct context * scontext,struct context * tcontext,u16 tclass,struct context * newcontext)1099 static int compute_sid_handle_invalid_context(
1100 struct context *scontext,
1101 struct context *tcontext,
1102 u16 tclass,
1103 struct context *newcontext)
1104 {
1105 char *s = NULL, *t = NULL, *n = NULL;
1106 u32 slen, tlen, nlen;
1107
1108 if (context_struct_to_string(scontext, &s, &slen) < 0)
1109 goto out;
1110 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
1111 goto out;
1112 if (context_struct_to_string(newcontext, &n, &nlen) < 0)
1113 goto out;
1114 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1115 "security_compute_sid: invalid context %s"
1116 " for scontext=%s"
1117 " tcontext=%s"
1118 " tclass=%s",
1119 n, s, t, policydb.p_class_val_to_name[tclass-1]);
1120 out:
1121 kfree(s);
1122 kfree(t);
1123 kfree(n);
1124 if (!selinux_enforcing)
1125 return 0;
1126 return -EACCES;
1127 }
1128
security_compute_sid(u32 ssid,u32 tsid,u16 tclass,u32 specified,u32 * out_sid)1129 static int security_compute_sid(u32 ssid,
1130 u32 tsid,
1131 u16 tclass,
1132 u32 specified,
1133 u32 *out_sid)
1134 {
1135 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1136 struct role_trans *roletr = NULL;
1137 struct avtab_key avkey;
1138 struct avtab_datum *avdatum;
1139 struct avtab_node *node;
1140 int rc = 0;
1141
1142 if (!ss_initialized) {
1143 switch (tclass) {
1144 case SECCLASS_PROCESS:
1145 *out_sid = ssid;
1146 break;
1147 default:
1148 *out_sid = tsid;
1149 break;
1150 }
1151 goto out;
1152 }
1153
1154 context_init(&newcontext);
1155
1156 read_lock(&policy_rwlock);
1157
1158 scontext = sidtab_search(&sidtab, ssid);
1159 if (!scontext) {
1160 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1161 __func__, ssid);
1162 rc = -EINVAL;
1163 goto out_unlock;
1164 }
1165 tcontext = sidtab_search(&sidtab, tsid);
1166 if (!tcontext) {
1167 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1168 __func__, tsid);
1169 rc = -EINVAL;
1170 goto out_unlock;
1171 }
1172
1173 /* Set the user identity. */
1174 switch (specified) {
1175 case AVTAB_TRANSITION:
1176 case AVTAB_CHANGE:
1177 /* Use the process user identity. */
1178 newcontext.user = scontext->user;
1179 break;
1180 case AVTAB_MEMBER:
1181 /* Use the related object owner. */
1182 newcontext.user = tcontext->user;
1183 break;
1184 }
1185
1186 /* Set the role and type to default values. */
1187 switch (tclass) {
1188 case SECCLASS_PROCESS:
1189 /* Use the current role and type of process. */
1190 newcontext.role = scontext->role;
1191 newcontext.type = scontext->type;
1192 break;
1193 default:
1194 /* Use the well-defined object role. */
1195 newcontext.role = OBJECT_R_VAL;
1196 /* Use the type of the related object. */
1197 newcontext.type = tcontext->type;
1198 }
1199
1200 /* Look for a type transition/member/change rule. */
1201 avkey.source_type = scontext->type;
1202 avkey.target_type = tcontext->type;
1203 avkey.target_class = tclass;
1204 avkey.specified = specified;
1205 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1206
1207 /* If no permanent rule, also check for enabled conditional rules */
1208 if (!avdatum) {
1209 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1210 for (; node; node = avtab_search_node_next(node, specified)) {
1211 if (node->key.specified & AVTAB_ENABLED) {
1212 avdatum = &node->datum;
1213 break;
1214 }
1215 }
1216 }
1217
1218 if (avdatum) {
1219 /* Use the type from the type transition/member/change rule. */
1220 newcontext.type = avdatum->data;
1221 }
1222
1223 /* Check for class-specific changes. */
1224 switch (tclass) {
1225 case SECCLASS_PROCESS:
1226 if (specified & AVTAB_TRANSITION) {
1227 /* Look for a role transition rule. */
1228 for (roletr = policydb.role_tr; roletr;
1229 roletr = roletr->next) {
1230 if (roletr->role == scontext->role &&
1231 roletr->type == tcontext->type) {
1232 /* Use the role transition rule. */
1233 newcontext.role = roletr->new_role;
1234 break;
1235 }
1236 }
1237 }
1238 break;
1239 default:
1240 break;
1241 }
1242
1243 /* Set the MLS attributes.
1244 This is done last because it may allocate memory. */
1245 rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
1246 if (rc)
1247 goto out_unlock;
1248
1249 /* Check the validity of the context. */
1250 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1251 rc = compute_sid_handle_invalid_context(scontext,
1252 tcontext,
1253 tclass,
1254 &newcontext);
1255 if (rc)
1256 goto out_unlock;
1257 }
1258 /* Obtain the sid for the context. */
1259 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1260 out_unlock:
1261 read_unlock(&policy_rwlock);
1262 context_destroy(&newcontext);
1263 out:
1264 return rc;
1265 }
1266
1267 /**
1268 * security_transition_sid - Compute the SID for a new subject/object.
1269 * @ssid: source security identifier
1270 * @tsid: target security identifier
1271 * @tclass: target security class
1272 * @out_sid: security identifier for new subject/object
1273 *
1274 * Compute a SID to use for labeling a new subject or object in the
1275 * class @tclass based on a SID pair (@ssid, @tsid).
1276 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1277 * if insufficient memory is available, or %0 if the new SID was
1278 * computed successfully.
1279 */
security_transition_sid(u32 ssid,u32 tsid,u16 tclass,u32 * out_sid)1280 int security_transition_sid(u32 ssid,
1281 u32 tsid,
1282 u16 tclass,
1283 u32 *out_sid)
1284 {
1285 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
1286 }
1287
1288 /**
1289 * security_member_sid - Compute the SID for member selection.
1290 * @ssid: source security identifier
1291 * @tsid: target security identifier
1292 * @tclass: target security class
1293 * @out_sid: security identifier for selected member
1294 *
1295 * Compute a SID to use when selecting a member of a polyinstantiated
1296 * object of class @tclass based on a SID pair (@ssid, @tsid).
1297 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1298 * if insufficient memory is available, or %0 if the SID was
1299 * computed successfully.
1300 */
security_member_sid(u32 ssid,u32 tsid,u16 tclass,u32 * out_sid)1301 int security_member_sid(u32 ssid,
1302 u32 tsid,
1303 u16 tclass,
1304 u32 *out_sid)
1305 {
1306 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
1307 }
1308
1309 /**
1310 * security_change_sid - Compute the SID for object relabeling.
1311 * @ssid: source security identifier
1312 * @tsid: target security identifier
1313 * @tclass: target security class
1314 * @out_sid: security identifier for selected member
1315 *
1316 * Compute a SID to use for relabeling an object of class @tclass
1317 * based on a SID pair (@ssid, @tsid).
1318 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1319 * if insufficient memory is available, or %0 if the SID was
1320 * computed successfully.
1321 */
security_change_sid(u32 ssid,u32 tsid,u16 tclass,u32 * out_sid)1322 int security_change_sid(u32 ssid,
1323 u32 tsid,
1324 u16 tclass,
1325 u32 *out_sid)
1326 {
1327 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
1328 }
1329
1330 /*
1331 * Verify that each kernel class that is defined in the
1332 * policy is correct
1333 */
validate_classes(struct policydb * p)1334 static int validate_classes(struct policydb *p)
1335 {
1336 int i, j;
1337 struct class_datum *cladatum;
1338 struct perm_datum *perdatum;
1339 u32 nprim, tmp, common_pts_len, perm_val, pol_val;
1340 u16 class_val;
1341 const struct selinux_class_perm *kdefs = &selinux_class_perm;
1342 const char *def_class, *def_perm, *pol_class;
1343 struct symtab *perms;
1344 bool print_unknown_handle = 0;
1345
1346 if (p->allow_unknown) {
1347 u32 num_classes = kdefs->cts_len;
1348 p->undefined_perms = kcalloc(num_classes, sizeof(u32), GFP_KERNEL);
1349 if (!p->undefined_perms)
1350 return -ENOMEM;
1351 }
1352
1353 for (i = 1; i < kdefs->cts_len; i++) {
1354 def_class = kdefs->class_to_string[i];
1355 if (!def_class)
1356 continue;
1357 if (i > p->p_classes.nprim) {
1358 printk(KERN_INFO
1359 "SELinux: class %s not defined in policy\n",
1360 def_class);
1361 if (p->reject_unknown)
1362 return -EINVAL;
1363 if (p->allow_unknown)
1364 p->undefined_perms[i-1] = ~0U;
1365 print_unknown_handle = 1;
1366 continue;
1367 }
1368 pol_class = p->p_class_val_to_name[i-1];
1369 if (strcmp(pol_class, def_class)) {
1370 printk(KERN_ERR
1371 "SELinux: class %d is incorrect, found %s but should be %s\n",
1372 i, pol_class, def_class);
1373 return -EINVAL;
1374 }
1375 }
1376 for (i = 0; i < kdefs->av_pts_len; i++) {
1377 class_val = kdefs->av_perm_to_string[i].tclass;
1378 perm_val = kdefs->av_perm_to_string[i].value;
1379 def_perm = kdefs->av_perm_to_string[i].name;
1380 if (class_val > p->p_classes.nprim)
1381 continue;
1382 pol_class = p->p_class_val_to_name[class_val-1];
1383 cladatum = hashtab_search(p->p_classes.table, pol_class);
1384 BUG_ON(!cladatum);
1385 perms = &cladatum->permissions;
1386 nprim = 1 << (perms->nprim - 1);
1387 if (perm_val > nprim) {
1388 printk(KERN_INFO
1389 "SELinux: permission %s in class %s not defined in policy\n",
1390 def_perm, pol_class);
1391 if (p->reject_unknown)
1392 return -EINVAL;
1393 if (p->allow_unknown)
1394 p->undefined_perms[class_val-1] |= perm_val;
1395 print_unknown_handle = 1;
1396 continue;
1397 }
1398 perdatum = hashtab_search(perms->table, def_perm);
1399 if (perdatum == NULL) {
1400 printk(KERN_ERR
1401 "SELinux: permission %s in class %s not found in policy, bad policy\n",
1402 def_perm, pol_class);
1403 return -EINVAL;
1404 }
1405 pol_val = 1 << (perdatum->value - 1);
1406 if (pol_val != perm_val) {
1407 printk(KERN_ERR
1408 "SELinux: permission %s in class %s has incorrect value\n",
1409 def_perm, pol_class);
1410 return -EINVAL;
1411 }
1412 }
1413 for (i = 0; i < kdefs->av_inherit_len; i++) {
1414 class_val = kdefs->av_inherit[i].tclass;
1415 if (class_val > p->p_classes.nprim)
1416 continue;
1417 pol_class = p->p_class_val_to_name[class_val-1];
1418 cladatum = hashtab_search(p->p_classes.table, pol_class);
1419 BUG_ON(!cladatum);
1420 if (!cladatum->comdatum) {
1421 printk(KERN_ERR
1422 "SELinux: class %s should have an inherits clause but does not\n",
1423 pol_class);
1424 return -EINVAL;
1425 }
1426 tmp = kdefs->av_inherit[i].common_base;
1427 common_pts_len = 0;
1428 while (!(tmp & 0x01)) {
1429 common_pts_len++;
1430 tmp >>= 1;
1431 }
1432 perms = &cladatum->comdatum->permissions;
1433 for (j = 0; j < common_pts_len; j++) {
1434 def_perm = kdefs->av_inherit[i].common_pts[j];
1435 if (j >= perms->nprim) {
1436 printk(KERN_INFO
1437 "SELinux: permission %s in class %s not defined in policy\n",
1438 def_perm, pol_class);
1439 if (p->reject_unknown)
1440 return -EINVAL;
1441 if (p->allow_unknown)
1442 p->undefined_perms[class_val-1] |= (1 << j);
1443 print_unknown_handle = 1;
1444 continue;
1445 }
1446 perdatum = hashtab_search(perms->table, def_perm);
1447 if (perdatum == NULL) {
1448 printk(KERN_ERR
1449 "SELinux: permission %s in class %s not found in policy, bad policy\n",
1450 def_perm, pol_class);
1451 return -EINVAL;
1452 }
1453 if (perdatum->value != j + 1) {
1454 printk(KERN_ERR
1455 "SELinux: permission %s in class %s has incorrect value\n",
1456 def_perm, pol_class);
1457 return -EINVAL;
1458 }
1459 }
1460 }
1461 if (print_unknown_handle)
1462 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
1463 (security_get_allow_unknown() ? "allowed" : "denied"));
1464 return 0;
1465 }
1466
1467 /* Clone the SID into the new SID table. */
clone_sid(u32 sid,struct context * context,void * arg)1468 static int clone_sid(u32 sid,
1469 struct context *context,
1470 void *arg)
1471 {
1472 struct sidtab *s = arg;
1473
1474 return sidtab_insert(s, sid, context);
1475 }
1476
convert_context_handle_invalid_context(struct context * context)1477 static inline int convert_context_handle_invalid_context(struct context *context)
1478 {
1479 int rc = 0;
1480
1481 if (selinux_enforcing) {
1482 rc = -EINVAL;
1483 } else {
1484 char *s;
1485 u32 len;
1486
1487 if (!context_struct_to_string(context, &s, &len)) {
1488 printk(KERN_WARNING
1489 "SELinux: Context %s would be invalid if enforcing\n",
1490 s);
1491 kfree(s);
1492 }
1493 }
1494 return rc;
1495 }
1496
1497 struct convert_context_args {
1498 struct policydb *oldp;
1499 struct policydb *newp;
1500 };
1501
1502 /*
1503 * Convert the values in the security context
1504 * structure `c' from the values specified
1505 * in the policy `p->oldp' to the values specified
1506 * in the policy `p->newp'. Verify that the
1507 * context is valid under the new policy.
1508 */
convert_context(u32 key,struct context * c,void * p)1509 static int convert_context(u32 key,
1510 struct context *c,
1511 void *p)
1512 {
1513 struct convert_context_args *args;
1514 struct context oldc;
1515 struct role_datum *role;
1516 struct type_datum *typdatum;
1517 struct user_datum *usrdatum;
1518 char *s;
1519 u32 len;
1520 int rc;
1521
1522 args = p;
1523
1524 if (c->str) {
1525 struct context ctx;
1526 s = kstrdup(c->str, GFP_KERNEL);
1527 if (!s) {
1528 rc = -ENOMEM;
1529 goto out;
1530 }
1531 rc = string_to_context_struct(args->newp, NULL, s,
1532 c->len, &ctx, SECSID_NULL);
1533 kfree(s);
1534 if (!rc) {
1535 printk(KERN_INFO
1536 "SELinux: Context %s became valid (mapped).\n",
1537 c->str);
1538 /* Replace string with mapped representation. */
1539 kfree(c->str);
1540 memcpy(c, &ctx, sizeof(*c));
1541 goto out;
1542 } else if (rc == -EINVAL) {
1543 /* Retain string representation for later mapping. */
1544 rc = 0;
1545 goto out;
1546 } else {
1547 /* Other error condition, e.g. ENOMEM. */
1548 printk(KERN_ERR
1549 "SELinux: Unable to map context %s, rc = %d.\n",
1550 c->str, -rc);
1551 goto out;
1552 }
1553 }
1554
1555 rc = context_cpy(&oldc, c);
1556 if (rc)
1557 goto out;
1558
1559 rc = -EINVAL;
1560
1561 /* Convert the user. */
1562 usrdatum = hashtab_search(args->newp->p_users.table,
1563 args->oldp->p_user_val_to_name[c->user - 1]);
1564 if (!usrdatum)
1565 goto bad;
1566 c->user = usrdatum->value;
1567
1568 /* Convert the role. */
1569 role = hashtab_search(args->newp->p_roles.table,
1570 args->oldp->p_role_val_to_name[c->role - 1]);
1571 if (!role)
1572 goto bad;
1573 c->role = role->value;
1574
1575 /* Convert the type. */
1576 typdatum = hashtab_search(args->newp->p_types.table,
1577 args->oldp->p_type_val_to_name[c->type - 1]);
1578 if (!typdatum)
1579 goto bad;
1580 c->type = typdatum->value;
1581
1582 rc = mls_convert_context(args->oldp, args->newp, c);
1583 if (rc)
1584 goto bad;
1585
1586 /* Check the validity of the new context. */
1587 if (!policydb_context_isvalid(args->newp, c)) {
1588 rc = convert_context_handle_invalid_context(&oldc);
1589 if (rc)
1590 goto bad;
1591 }
1592
1593 context_destroy(&oldc);
1594 rc = 0;
1595 out:
1596 return rc;
1597 bad:
1598 /* Map old representation to string and save it. */
1599 if (context_struct_to_string(&oldc, &s, &len))
1600 return -ENOMEM;
1601 context_destroy(&oldc);
1602 context_destroy(c);
1603 c->str = s;
1604 c->len = len;
1605 printk(KERN_INFO
1606 "SELinux: Context %s became invalid (unmapped).\n",
1607 c->str);
1608 rc = 0;
1609 goto out;
1610 }
1611
security_load_policycaps(void)1612 static void security_load_policycaps(void)
1613 {
1614 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1615 POLICYDB_CAPABILITY_NETPEER);
1616 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1617 POLICYDB_CAPABILITY_OPENPERM);
1618 }
1619
1620 extern void selinux_complete_init(void);
1621 static int security_preserve_bools(struct policydb *p);
1622
1623 /**
1624 * security_load_policy - Load a security policy configuration.
1625 * @data: binary policy data
1626 * @len: length of data in bytes
1627 *
1628 * Load a new set of security policy configuration data,
1629 * validate it and convert the SID table as necessary.
1630 * This function will flush the access vector cache after
1631 * loading the new policy.
1632 */
security_load_policy(void * data,size_t len)1633 int security_load_policy(void *data, size_t len)
1634 {
1635 struct policydb oldpolicydb, newpolicydb;
1636 struct sidtab oldsidtab, newsidtab;
1637 struct convert_context_args args;
1638 u32 seqno;
1639 int rc = 0;
1640 struct policy_file file = { data, len }, *fp = &file;
1641
1642 if (!ss_initialized) {
1643 avtab_cache_init();
1644 if (policydb_read(&policydb, fp)) {
1645 avtab_cache_destroy();
1646 return -EINVAL;
1647 }
1648 if (policydb_load_isids(&policydb, &sidtab)) {
1649 policydb_destroy(&policydb);
1650 avtab_cache_destroy();
1651 return -EINVAL;
1652 }
1653 /* Verify that the kernel defined classes are correct. */
1654 if (validate_classes(&policydb)) {
1655 printk(KERN_ERR
1656 "SELinux: the definition of a class is incorrect\n");
1657 sidtab_destroy(&sidtab);
1658 policydb_destroy(&policydb);
1659 avtab_cache_destroy();
1660 return -EINVAL;
1661 }
1662 security_load_policycaps();
1663 policydb_loaded_version = policydb.policyvers;
1664 ss_initialized = 1;
1665 seqno = ++latest_granting;
1666 selinux_complete_init();
1667 avc_ss_reset(seqno);
1668 selnl_notify_policyload(seqno);
1669 selinux_netlbl_cache_invalidate();
1670 selinux_xfrm_notify_policyload();
1671 return 0;
1672 }
1673
1674 #if 0
1675 sidtab_hash_eval(&sidtab, "sids");
1676 #endif
1677
1678 if (policydb_read(&newpolicydb, fp))
1679 return -EINVAL;
1680
1681 if (sidtab_init(&newsidtab)) {
1682 policydb_destroy(&newpolicydb);
1683 return -ENOMEM;
1684 }
1685
1686 /* Verify that the kernel defined classes are correct. */
1687 if (validate_classes(&newpolicydb)) {
1688 printk(KERN_ERR
1689 "SELinux: the definition of a class is incorrect\n");
1690 rc = -EINVAL;
1691 goto err;
1692 }
1693
1694 rc = security_preserve_bools(&newpolicydb);
1695 if (rc) {
1696 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
1697 goto err;
1698 }
1699
1700 /* Clone the SID table. */
1701 sidtab_shutdown(&sidtab);
1702 if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1703 rc = -ENOMEM;
1704 goto err;
1705 }
1706
1707 /*
1708 * Convert the internal representations of contexts
1709 * in the new SID table.
1710 */
1711 args.oldp = &policydb;
1712 args.newp = &newpolicydb;
1713 rc = sidtab_map(&newsidtab, convert_context, &args);
1714 if (rc)
1715 goto err;
1716
1717 /* Save the old policydb and SID table to free later. */
1718 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1719 sidtab_set(&oldsidtab, &sidtab);
1720
1721 /* Install the new policydb and SID table. */
1722 write_lock_irq(&policy_rwlock);
1723 memcpy(&policydb, &newpolicydb, sizeof policydb);
1724 sidtab_set(&sidtab, &newsidtab);
1725 security_load_policycaps();
1726 seqno = ++latest_granting;
1727 policydb_loaded_version = policydb.policyvers;
1728 write_unlock_irq(&policy_rwlock);
1729
1730 /* Free the old policydb and SID table. */
1731 policydb_destroy(&oldpolicydb);
1732 sidtab_destroy(&oldsidtab);
1733
1734 avc_ss_reset(seqno);
1735 selnl_notify_policyload(seqno);
1736 selinux_netlbl_cache_invalidate();
1737 selinux_xfrm_notify_policyload();
1738
1739 return 0;
1740
1741 err:
1742 sidtab_destroy(&newsidtab);
1743 policydb_destroy(&newpolicydb);
1744 return rc;
1745
1746 }
1747
1748 /**
1749 * security_port_sid - Obtain the SID for a port.
1750 * @protocol: protocol number
1751 * @port: port number
1752 * @out_sid: security identifier
1753 */
security_port_sid(u8 protocol,u16 port,u32 * out_sid)1754 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1755 {
1756 struct ocontext *c;
1757 int rc = 0;
1758
1759 read_lock(&policy_rwlock);
1760
1761 c = policydb.ocontexts[OCON_PORT];
1762 while (c) {
1763 if (c->u.port.protocol == protocol &&
1764 c->u.port.low_port <= port &&
1765 c->u.port.high_port >= port)
1766 break;
1767 c = c->next;
1768 }
1769
1770 if (c) {
1771 if (!c->sid[0]) {
1772 rc = sidtab_context_to_sid(&sidtab,
1773 &c->context[0],
1774 &c->sid[0]);
1775 if (rc)
1776 goto out;
1777 }
1778 *out_sid = c->sid[0];
1779 } else {
1780 *out_sid = SECINITSID_PORT;
1781 }
1782
1783 out:
1784 read_unlock(&policy_rwlock);
1785 return rc;
1786 }
1787
1788 /**
1789 * security_netif_sid - Obtain the SID for a network interface.
1790 * @name: interface name
1791 * @if_sid: interface SID
1792 */
security_netif_sid(char * name,u32 * if_sid)1793 int security_netif_sid(char *name, u32 *if_sid)
1794 {
1795 int rc = 0;
1796 struct ocontext *c;
1797
1798 read_lock(&policy_rwlock);
1799
1800 c = policydb.ocontexts[OCON_NETIF];
1801 while (c) {
1802 if (strcmp(name, c->u.name) == 0)
1803 break;
1804 c = c->next;
1805 }
1806
1807 if (c) {
1808 if (!c->sid[0] || !c->sid[1]) {
1809 rc = sidtab_context_to_sid(&sidtab,
1810 &c->context[0],
1811 &c->sid[0]);
1812 if (rc)
1813 goto out;
1814 rc = sidtab_context_to_sid(&sidtab,
1815 &c->context[1],
1816 &c->sid[1]);
1817 if (rc)
1818 goto out;
1819 }
1820 *if_sid = c->sid[0];
1821 } else
1822 *if_sid = SECINITSID_NETIF;
1823
1824 out:
1825 read_unlock(&policy_rwlock);
1826 return rc;
1827 }
1828
match_ipv6_addrmask(u32 * input,u32 * addr,u32 * mask)1829 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1830 {
1831 int i, fail = 0;
1832
1833 for (i = 0; i < 4; i++)
1834 if (addr[i] != (input[i] & mask[i])) {
1835 fail = 1;
1836 break;
1837 }
1838
1839 return !fail;
1840 }
1841
1842 /**
1843 * security_node_sid - Obtain the SID for a node (host).
1844 * @domain: communication domain aka address family
1845 * @addrp: address
1846 * @addrlen: address length in bytes
1847 * @out_sid: security identifier
1848 */
security_node_sid(u16 domain,void * addrp,u32 addrlen,u32 * out_sid)1849 int security_node_sid(u16 domain,
1850 void *addrp,
1851 u32 addrlen,
1852 u32 *out_sid)
1853 {
1854 int rc = 0;
1855 struct ocontext *c;
1856
1857 read_lock(&policy_rwlock);
1858
1859 switch (domain) {
1860 case AF_INET: {
1861 u32 addr;
1862
1863 if (addrlen != sizeof(u32)) {
1864 rc = -EINVAL;
1865 goto out;
1866 }
1867
1868 addr = *((u32 *)addrp);
1869
1870 c = policydb.ocontexts[OCON_NODE];
1871 while (c) {
1872 if (c->u.node.addr == (addr & c->u.node.mask))
1873 break;
1874 c = c->next;
1875 }
1876 break;
1877 }
1878
1879 case AF_INET6:
1880 if (addrlen != sizeof(u64) * 2) {
1881 rc = -EINVAL;
1882 goto out;
1883 }
1884 c = policydb.ocontexts[OCON_NODE6];
1885 while (c) {
1886 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1887 c->u.node6.mask))
1888 break;
1889 c = c->next;
1890 }
1891 break;
1892
1893 default:
1894 *out_sid = SECINITSID_NODE;
1895 goto out;
1896 }
1897
1898 if (c) {
1899 if (!c->sid[0]) {
1900 rc = sidtab_context_to_sid(&sidtab,
1901 &c->context[0],
1902 &c->sid[0]);
1903 if (rc)
1904 goto out;
1905 }
1906 *out_sid = c->sid[0];
1907 } else {
1908 *out_sid = SECINITSID_NODE;
1909 }
1910
1911 out:
1912 read_unlock(&policy_rwlock);
1913 return rc;
1914 }
1915
1916 #define SIDS_NEL 25
1917
1918 /**
1919 * security_get_user_sids - Obtain reachable SIDs for a user.
1920 * @fromsid: starting SID
1921 * @username: username
1922 * @sids: array of reachable SIDs for user
1923 * @nel: number of elements in @sids
1924 *
1925 * Generate the set of SIDs for legal security contexts
1926 * for a given user that can be reached by @fromsid.
1927 * Set *@sids to point to a dynamically allocated
1928 * array containing the set of SIDs. Set *@nel to the
1929 * number of elements in the array.
1930 */
1931
security_get_user_sids(u32 fromsid,char * username,u32 ** sids,u32 * nel)1932 int security_get_user_sids(u32 fromsid,
1933 char *username,
1934 u32 **sids,
1935 u32 *nel)
1936 {
1937 struct context *fromcon, usercon;
1938 u32 *mysids = NULL, *mysids2, sid;
1939 u32 mynel = 0, maxnel = SIDS_NEL;
1940 struct user_datum *user;
1941 struct role_datum *role;
1942 struct ebitmap_node *rnode, *tnode;
1943 int rc = 0, i, j;
1944
1945 *sids = NULL;
1946 *nel = 0;
1947
1948 if (!ss_initialized)
1949 goto out;
1950
1951 read_lock(&policy_rwlock);
1952
1953 context_init(&usercon);
1954
1955 fromcon = sidtab_search(&sidtab, fromsid);
1956 if (!fromcon) {
1957 rc = -EINVAL;
1958 goto out_unlock;
1959 }
1960
1961 user = hashtab_search(policydb.p_users.table, username);
1962 if (!user) {
1963 rc = -EINVAL;
1964 goto out_unlock;
1965 }
1966 usercon.user = user->value;
1967
1968 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1969 if (!mysids) {
1970 rc = -ENOMEM;
1971 goto out_unlock;
1972 }
1973
1974 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
1975 role = policydb.role_val_to_struct[i];
1976 usercon.role = i+1;
1977 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
1978 usercon.type = j+1;
1979
1980 if (mls_setup_user_range(fromcon, user, &usercon))
1981 continue;
1982
1983 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1984 if (rc)
1985 goto out_unlock;
1986 if (mynel < maxnel) {
1987 mysids[mynel++] = sid;
1988 } else {
1989 maxnel += SIDS_NEL;
1990 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1991 if (!mysids2) {
1992 rc = -ENOMEM;
1993 goto out_unlock;
1994 }
1995 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1996 kfree(mysids);
1997 mysids = mysids2;
1998 mysids[mynel++] = sid;
1999 }
2000 }
2001 }
2002
2003 out_unlock:
2004 read_unlock(&policy_rwlock);
2005 if (rc || !mynel) {
2006 kfree(mysids);
2007 goto out;
2008 }
2009
2010 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2011 if (!mysids2) {
2012 rc = -ENOMEM;
2013 kfree(mysids);
2014 goto out;
2015 }
2016 for (i = 0, j = 0; i < mynel; i++) {
2017 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2018 SECCLASS_PROCESS,
2019 PROCESS__TRANSITION, AVC_STRICT,
2020 NULL);
2021 if (!rc)
2022 mysids2[j++] = mysids[i];
2023 cond_resched();
2024 }
2025 rc = 0;
2026 kfree(mysids);
2027 *sids = mysids2;
2028 *nel = j;
2029 out:
2030 return rc;
2031 }
2032
2033 /**
2034 * security_genfs_sid - Obtain a SID for a file in a filesystem
2035 * @fstype: filesystem type
2036 * @path: path from root of mount
2037 * @sclass: file security class
2038 * @sid: SID for path
2039 *
2040 * Obtain a SID to use for a file in a filesystem that
2041 * cannot support xattr or use a fixed labeling behavior like
2042 * transition SIDs or task SIDs.
2043 */
security_genfs_sid(const char * fstype,char * path,u16 sclass,u32 * sid)2044 int security_genfs_sid(const char *fstype,
2045 char *path,
2046 u16 sclass,
2047 u32 *sid)
2048 {
2049 int len;
2050 struct genfs *genfs;
2051 struct ocontext *c;
2052 int rc = 0, cmp = 0;
2053
2054 while (path[0] == '/' && path[1] == '/')
2055 path++;
2056
2057 read_lock(&policy_rwlock);
2058
2059 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2060 cmp = strcmp(fstype, genfs->fstype);
2061 if (cmp <= 0)
2062 break;
2063 }
2064
2065 if (!genfs || cmp) {
2066 *sid = SECINITSID_UNLABELED;
2067 rc = -ENOENT;
2068 goto out;
2069 }
2070
2071 for (c = genfs->head; c; c = c->next) {
2072 len = strlen(c->u.name);
2073 if ((!c->v.sclass || sclass == c->v.sclass) &&
2074 (strncmp(c->u.name, path, len) == 0))
2075 break;
2076 }
2077
2078 if (!c) {
2079 *sid = SECINITSID_UNLABELED;
2080 rc = -ENOENT;
2081 goto out;
2082 }
2083
2084 if (!c->sid[0]) {
2085 rc = sidtab_context_to_sid(&sidtab,
2086 &c->context[0],
2087 &c->sid[0]);
2088 if (rc)
2089 goto out;
2090 }
2091
2092 *sid = c->sid[0];
2093 out:
2094 read_unlock(&policy_rwlock);
2095 return rc;
2096 }
2097
2098 /**
2099 * security_fs_use - Determine how to handle labeling for a filesystem.
2100 * @fstype: filesystem type
2101 * @behavior: labeling behavior
2102 * @sid: SID for filesystem (superblock)
2103 */
security_fs_use(const char * fstype,unsigned int * behavior,u32 * sid)2104 int security_fs_use(
2105 const char *fstype,
2106 unsigned int *behavior,
2107 u32 *sid)
2108 {
2109 int rc = 0;
2110 struct ocontext *c;
2111
2112 read_lock(&policy_rwlock);
2113
2114 c = policydb.ocontexts[OCON_FSUSE];
2115 while (c) {
2116 if (strcmp(fstype, c->u.name) == 0)
2117 break;
2118 c = c->next;
2119 }
2120
2121 if (c) {
2122 *behavior = c->v.behavior;
2123 if (!c->sid[0]) {
2124 rc = sidtab_context_to_sid(&sidtab,
2125 &c->context[0],
2126 &c->sid[0]);
2127 if (rc)
2128 goto out;
2129 }
2130 *sid = c->sid[0];
2131 } else {
2132 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2133 if (rc) {
2134 *behavior = SECURITY_FS_USE_NONE;
2135 rc = 0;
2136 } else {
2137 *behavior = SECURITY_FS_USE_GENFS;
2138 }
2139 }
2140
2141 out:
2142 read_unlock(&policy_rwlock);
2143 return rc;
2144 }
2145
security_get_bools(int * len,char *** names,int ** values)2146 int security_get_bools(int *len, char ***names, int **values)
2147 {
2148 int i, rc = -ENOMEM;
2149
2150 read_lock(&policy_rwlock);
2151 *names = NULL;
2152 *values = NULL;
2153
2154 *len = policydb.p_bools.nprim;
2155 if (!*len) {
2156 rc = 0;
2157 goto out;
2158 }
2159
2160 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2161 if (!*names)
2162 goto err;
2163
2164 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2165 if (!*values)
2166 goto err;
2167
2168 for (i = 0; i < *len; i++) {
2169 size_t name_len;
2170 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2171 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
2172 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2173 if (!(*names)[i])
2174 goto err;
2175 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
2176 (*names)[i][name_len - 1] = 0;
2177 }
2178 rc = 0;
2179 out:
2180 read_unlock(&policy_rwlock);
2181 return rc;
2182 err:
2183 if (*names) {
2184 for (i = 0; i < *len; i++)
2185 kfree((*names)[i]);
2186 }
2187 kfree(*values);
2188 goto out;
2189 }
2190
2191
security_set_bools(int len,int * values)2192 int security_set_bools(int len, int *values)
2193 {
2194 int i, rc = 0;
2195 int lenp, seqno = 0;
2196 struct cond_node *cur;
2197
2198 write_lock_irq(&policy_rwlock);
2199
2200 lenp = policydb.p_bools.nprim;
2201 if (len != lenp) {
2202 rc = -EFAULT;
2203 goto out;
2204 }
2205
2206 for (i = 0; i < len; i++) {
2207 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2208 audit_log(current->audit_context, GFP_ATOMIC,
2209 AUDIT_MAC_CONFIG_CHANGE,
2210 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2211 policydb.p_bool_val_to_name[i],
2212 !!values[i],
2213 policydb.bool_val_to_struct[i]->state,
2214 audit_get_loginuid(current),
2215 audit_get_sessionid(current));
2216 }
2217 if (values[i])
2218 policydb.bool_val_to_struct[i]->state = 1;
2219 else
2220 policydb.bool_val_to_struct[i]->state = 0;
2221 }
2222
2223 for (cur = policydb.cond_list; cur; cur = cur->next) {
2224 rc = evaluate_cond_node(&policydb, cur);
2225 if (rc)
2226 goto out;
2227 }
2228
2229 seqno = ++latest_granting;
2230
2231 out:
2232 write_unlock_irq(&policy_rwlock);
2233 if (!rc) {
2234 avc_ss_reset(seqno);
2235 selnl_notify_policyload(seqno);
2236 selinux_xfrm_notify_policyload();
2237 }
2238 return rc;
2239 }
2240
security_get_bool_value(int bool)2241 int security_get_bool_value(int bool)
2242 {
2243 int rc = 0;
2244 int len;
2245
2246 read_lock(&policy_rwlock);
2247
2248 len = policydb.p_bools.nprim;
2249 if (bool >= len) {
2250 rc = -EFAULT;
2251 goto out;
2252 }
2253
2254 rc = policydb.bool_val_to_struct[bool]->state;
2255 out:
2256 read_unlock(&policy_rwlock);
2257 return rc;
2258 }
2259
security_preserve_bools(struct policydb * p)2260 static int security_preserve_bools(struct policydb *p)
2261 {
2262 int rc, nbools = 0, *bvalues = NULL, i;
2263 char **bnames = NULL;
2264 struct cond_bool_datum *booldatum;
2265 struct cond_node *cur;
2266
2267 rc = security_get_bools(&nbools, &bnames, &bvalues);
2268 if (rc)
2269 goto out;
2270 for (i = 0; i < nbools; i++) {
2271 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2272 if (booldatum)
2273 booldatum->state = bvalues[i];
2274 }
2275 for (cur = p->cond_list; cur; cur = cur->next) {
2276 rc = evaluate_cond_node(p, cur);
2277 if (rc)
2278 goto out;
2279 }
2280
2281 out:
2282 if (bnames) {
2283 for (i = 0; i < nbools; i++)
2284 kfree(bnames[i]);
2285 }
2286 kfree(bnames);
2287 kfree(bvalues);
2288 return rc;
2289 }
2290
2291 /*
2292 * security_sid_mls_copy() - computes a new sid based on the given
2293 * sid and the mls portion of mls_sid.
2294 */
security_sid_mls_copy(u32 sid,u32 mls_sid,u32 * new_sid)2295 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2296 {
2297 struct context *context1;
2298 struct context *context2;
2299 struct context newcon;
2300 char *s;
2301 u32 len;
2302 int rc = 0;
2303
2304 if (!ss_initialized || !selinux_mls_enabled) {
2305 *new_sid = sid;
2306 goto out;
2307 }
2308
2309 context_init(&newcon);
2310
2311 read_lock(&policy_rwlock);
2312 context1 = sidtab_search(&sidtab, sid);
2313 if (!context1) {
2314 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2315 __func__, sid);
2316 rc = -EINVAL;
2317 goto out_unlock;
2318 }
2319
2320 context2 = sidtab_search(&sidtab, mls_sid);
2321 if (!context2) {
2322 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2323 __func__, mls_sid);
2324 rc = -EINVAL;
2325 goto out_unlock;
2326 }
2327
2328 newcon.user = context1->user;
2329 newcon.role = context1->role;
2330 newcon.type = context1->type;
2331 rc = mls_context_cpy(&newcon, context2);
2332 if (rc)
2333 goto out_unlock;
2334
2335 /* Check the validity of the new context. */
2336 if (!policydb_context_isvalid(&policydb, &newcon)) {
2337 rc = convert_context_handle_invalid_context(&newcon);
2338 if (rc)
2339 goto bad;
2340 }
2341
2342 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2343 goto out_unlock;
2344
2345 bad:
2346 if (!context_struct_to_string(&newcon, &s, &len)) {
2347 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2348 "security_sid_mls_copy: invalid context %s", s);
2349 kfree(s);
2350 }
2351
2352 out_unlock:
2353 read_unlock(&policy_rwlock);
2354 context_destroy(&newcon);
2355 out:
2356 return rc;
2357 }
2358
2359 /**
2360 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2361 * @nlbl_sid: NetLabel SID
2362 * @nlbl_type: NetLabel labeling protocol type
2363 * @xfrm_sid: XFRM SID
2364 *
2365 * Description:
2366 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2367 * resolved into a single SID it is returned via @peer_sid and the function
2368 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2369 * returns a negative value. A table summarizing the behavior is below:
2370 *
2371 * | function return | @sid
2372 * ------------------------------+-----------------+-----------------
2373 * no peer labels | 0 | SECSID_NULL
2374 * single peer label | 0 | <peer_label>
2375 * multiple, consistent labels | 0 | <peer_label>
2376 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2377 *
2378 */
security_net_peersid_resolve(u32 nlbl_sid,u32 nlbl_type,u32 xfrm_sid,u32 * peer_sid)2379 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2380 u32 xfrm_sid,
2381 u32 *peer_sid)
2382 {
2383 int rc;
2384 struct context *nlbl_ctx;
2385 struct context *xfrm_ctx;
2386
2387 /* handle the common (which also happens to be the set of easy) cases
2388 * right away, these two if statements catch everything involving a
2389 * single or absent peer SID/label */
2390 if (xfrm_sid == SECSID_NULL) {
2391 *peer_sid = nlbl_sid;
2392 return 0;
2393 }
2394 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2395 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2396 * is present */
2397 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2398 *peer_sid = xfrm_sid;
2399 return 0;
2400 }
2401
2402 /* we don't need to check ss_initialized here since the only way both
2403 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2404 * security server was initialized and ss_initialized was true */
2405 if (!selinux_mls_enabled) {
2406 *peer_sid = SECSID_NULL;
2407 return 0;
2408 }
2409
2410 read_lock(&policy_rwlock);
2411
2412 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2413 if (!nlbl_ctx) {
2414 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2415 __func__, nlbl_sid);
2416 rc = -EINVAL;
2417 goto out_slowpath;
2418 }
2419 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2420 if (!xfrm_ctx) {
2421 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2422 __func__, xfrm_sid);
2423 rc = -EINVAL;
2424 goto out_slowpath;
2425 }
2426 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2427
2428 out_slowpath:
2429 read_unlock(&policy_rwlock);
2430 if (rc == 0)
2431 /* at present NetLabel SIDs/labels really only carry MLS
2432 * information so if the MLS portion of the NetLabel SID
2433 * matches the MLS portion of the labeled XFRM SID/label
2434 * then pass along the XFRM SID as it is the most
2435 * expressive */
2436 *peer_sid = xfrm_sid;
2437 else
2438 *peer_sid = SECSID_NULL;
2439 return rc;
2440 }
2441
get_classes_callback(void * k,void * d,void * args)2442 static int get_classes_callback(void *k, void *d, void *args)
2443 {
2444 struct class_datum *datum = d;
2445 char *name = k, **classes = args;
2446 int value = datum->value - 1;
2447
2448 classes[value] = kstrdup(name, GFP_ATOMIC);
2449 if (!classes[value])
2450 return -ENOMEM;
2451
2452 return 0;
2453 }
2454
security_get_classes(char *** classes,int * nclasses)2455 int security_get_classes(char ***classes, int *nclasses)
2456 {
2457 int rc = -ENOMEM;
2458
2459 read_lock(&policy_rwlock);
2460
2461 *nclasses = policydb.p_classes.nprim;
2462 *classes = kcalloc(*nclasses, sizeof(*classes), GFP_ATOMIC);
2463 if (!*classes)
2464 goto out;
2465
2466 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2467 *classes);
2468 if (rc < 0) {
2469 int i;
2470 for (i = 0; i < *nclasses; i++)
2471 kfree((*classes)[i]);
2472 kfree(*classes);
2473 }
2474
2475 out:
2476 read_unlock(&policy_rwlock);
2477 return rc;
2478 }
2479
get_permissions_callback(void * k,void * d,void * args)2480 static int get_permissions_callback(void *k, void *d, void *args)
2481 {
2482 struct perm_datum *datum = d;
2483 char *name = k, **perms = args;
2484 int value = datum->value - 1;
2485
2486 perms[value] = kstrdup(name, GFP_ATOMIC);
2487 if (!perms[value])
2488 return -ENOMEM;
2489
2490 return 0;
2491 }
2492
security_get_permissions(char * class,char *** perms,int * nperms)2493 int security_get_permissions(char *class, char ***perms, int *nperms)
2494 {
2495 int rc = -ENOMEM, i;
2496 struct class_datum *match;
2497
2498 read_lock(&policy_rwlock);
2499
2500 match = hashtab_search(policydb.p_classes.table, class);
2501 if (!match) {
2502 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2503 __func__, class);
2504 rc = -EINVAL;
2505 goto out;
2506 }
2507
2508 *nperms = match->permissions.nprim;
2509 *perms = kcalloc(*nperms, sizeof(*perms), GFP_ATOMIC);
2510 if (!*perms)
2511 goto out;
2512
2513 if (match->comdatum) {
2514 rc = hashtab_map(match->comdatum->permissions.table,
2515 get_permissions_callback, *perms);
2516 if (rc < 0)
2517 goto err;
2518 }
2519
2520 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2521 *perms);
2522 if (rc < 0)
2523 goto err;
2524
2525 out:
2526 read_unlock(&policy_rwlock);
2527 return rc;
2528
2529 err:
2530 read_unlock(&policy_rwlock);
2531 for (i = 0; i < *nperms; i++)
2532 kfree((*perms)[i]);
2533 kfree(*perms);
2534 return rc;
2535 }
2536
security_get_reject_unknown(void)2537 int security_get_reject_unknown(void)
2538 {
2539 return policydb.reject_unknown;
2540 }
2541
security_get_allow_unknown(void)2542 int security_get_allow_unknown(void)
2543 {
2544 return policydb.allow_unknown;
2545 }
2546
2547 /**
2548 * security_policycap_supported - Check for a specific policy capability
2549 * @req_cap: capability
2550 *
2551 * Description:
2552 * This function queries the currently loaded policy to see if it supports the
2553 * capability specified by @req_cap. Returns true (1) if the capability is
2554 * supported, false (0) if it isn't supported.
2555 *
2556 */
security_policycap_supported(unsigned int req_cap)2557 int security_policycap_supported(unsigned int req_cap)
2558 {
2559 int rc;
2560
2561 read_lock(&policy_rwlock);
2562 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2563 read_unlock(&policy_rwlock);
2564
2565 return rc;
2566 }
2567
2568 struct selinux_audit_rule {
2569 u32 au_seqno;
2570 struct context au_ctxt;
2571 };
2572
selinux_audit_rule_free(void * vrule)2573 void selinux_audit_rule_free(void *vrule)
2574 {
2575 struct selinux_audit_rule *rule = vrule;
2576
2577 if (rule) {
2578 context_destroy(&rule->au_ctxt);
2579 kfree(rule);
2580 }
2581 }
2582
selinux_audit_rule_init(u32 field,u32 op,char * rulestr,void ** vrule)2583 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2584 {
2585 struct selinux_audit_rule *tmprule;
2586 struct role_datum *roledatum;
2587 struct type_datum *typedatum;
2588 struct user_datum *userdatum;
2589 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2590 int rc = 0;
2591
2592 *rule = NULL;
2593
2594 if (!ss_initialized)
2595 return -EOPNOTSUPP;
2596
2597 switch (field) {
2598 case AUDIT_SUBJ_USER:
2599 case AUDIT_SUBJ_ROLE:
2600 case AUDIT_SUBJ_TYPE:
2601 case AUDIT_OBJ_USER:
2602 case AUDIT_OBJ_ROLE:
2603 case AUDIT_OBJ_TYPE:
2604 /* only 'equals' and 'not equals' fit user, role, and type */
2605 if (op != Audit_equal && op != Audit_not_equal)
2606 return -EINVAL;
2607 break;
2608 case AUDIT_SUBJ_SEN:
2609 case AUDIT_SUBJ_CLR:
2610 case AUDIT_OBJ_LEV_LOW:
2611 case AUDIT_OBJ_LEV_HIGH:
2612 /* we do not allow a range, indicated by the presense of '-' */
2613 if (strchr(rulestr, '-'))
2614 return -EINVAL;
2615 break;
2616 default:
2617 /* only the above fields are valid */
2618 return -EINVAL;
2619 }
2620
2621 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2622 if (!tmprule)
2623 return -ENOMEM;
2624
2625 context_init(&tmprule->au_ctxt);
2626
2627 read_lock(&policy_rwlock);
2628
2629 tmprule->au_seqno = latest_granting;
2630
2631 switch (field) {
2632 case AUDIT_SUBJ_USER:
2633 case AUDIT_OBJ_USER:
2634 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2635 if (!userdatum)
2636 rc = -EINVAL;
2637 else
2638 tmprule->au_ctxt.user = userdatum->value;
2639 break;
2640 case AUDIT_SUBJ_ROLE:
2641 case AUDIT_OBJ_ROLE:
2642 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2643 if (!roledatum)
2644 rc = -EINVAL;
2645 else
2646 tmprule->au_ctxt.role = roledatum->value;
2647 break;
2648 case AUDIT_SUBJ_TYPE:
2649 case AUDIT_OBJ_TYPE:
2650 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2651 if (!typedatum)
2652 rc = -EINVAL;
2653 else
2654 tmprule->au_ctxt.type = typedatum->value;
2655 break;
2656 case AUDIT_SUBJ_SEN:
2657 case AUDIT_SUBJ_CLR:
2658 case AUDIT_OBJ_LEV_LOW:
2659 case AUDIT_OBJ_LEV_HIGH:
2660 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2661 break;
2662 }
2663
2664 read_unlock(&policy_rwlock);
2665
2666 if (rc) {
2667 selinux_audit_rule_free(tmprule);
2668 tmprule = NULL;
2669 }
2670
2671 *rule = tmprule;
2672
2673 return rc;
2674 }
2675
2676 /* Check to see if the rule contains any selinux fields */
selinux_audit_rule_known(struct audit_krule * rule)2677 int selinux_audit_rule_known(struct audit_krule *rule)
2678 {
2679 int i;
2680
2681 for (i = 0; i < rule->field_count; i++) {
2682 struct audit_field *f = &rule->fields[i];
2683 switch (f->type) {
2684 case AUDIT_SUBJ_USER:
2685 case AUDIT_SUBJ_ROLE:
2686 case AUDIT_SUBJ_TYPE:
2687 case AUDIT_SUBJ_SEN:
2688 case AUDIT_SUBJ_CLR:
2689 case AUDIT_OBJ_USER:
2690 case AUDIT_OBJ_ROLE:
2691 case AUDIT_OBJ_TYPE:
2692 case AUDIT_OBJ_LEV_LOW:
2693 case AUDIT_OBJ_LEV_HIGH:
2694 return 1;
2695 }
2696 }
2697
2698 return 0;
2699 }
2700
selinux_audit_rule_match(u32 sid,u32 field,u32 op,void * vrule,struct audit_context * actx)2701 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2702 struct audit_context *actx)
2703 {
2704 struct context *ctxt;
2705 struct mls_level *level;
2706 struct selinux_audit_rule *rule = vrule;
2707 int match = 0;
2708
2709 if (!rule) {
2710 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2711 "selinux_audit_rule_match: missing rule\n");
2712 return -ENOENT;
2713 }
2714
2715 read_lock(&policy_rwlock);
2716
2717 if (rule->au_seqno < latest_granting) {
2718 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2719 "selinux_audit_rule_match: stale rule\n");
2720 match = -ESTALE;
2721 goto out;
2722 }
2723
2724 ctxt = sidtab_search(&sidtab, sid);
2725 if (!ctxt) {
2726 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2727 "selinux_audit_rule_match: unrecognized SID %d\n",
2728 sid);
2729 match = -ENOENT;
2730 goto out;
2731 }
2732
2733 /* a field/op pair that is not caught here will simply fall through
2734 without a match */
2735 switch (field) {
2736 case AUDIT_SUBJ_USER:
2737 case AUDIT_OBJ_USER:
2738 switch (op) {
2739 case Audit_equal:
2740 match = (ctxt->user == rule->au_ctxt.user);
2741 break;
2742 case Audit_not_equal:
2743 match = (ctxt->user != rule->au_ctxt.user);
2744 break;
2745 }
2746 break;
2747 case AUDIT_SUBJ_ROLE:
2748 case AUDIT_OBJ_ROLE:
2749 switch (op) {
2750 case Audit_equal:
2751 match = (ctxt->role == rule->au_ctxt.role);
2752 break;
2753 case Audit_not_equal:
2754 match = (ctxt->role != rule->au_ctxt.role);
2755 break;
2756 }
2757 break;
2758 case AUDIT_SUBJ_TYPE:
2759 case AUDIT_OBJ_TYPE:
2760 switch (op) {
2761 case Audit_equal:
2762 match = (ctxt->type == rule->au_ctxt.type);
2763 break;
2764 case Audit_not_equal:
2765 match = (ctxt->type != rule->au_ctxt.type);
2766 break;
2767 }
2768 break;
2769 case AUDIT_SUBJ_SEN:
2770 case AUDIT_SUBJ_CLR:
2771 case AUDIT_OBJ_LEV_LOW:
2772 case AUDIT_OBJ_LEV_HIGH:
2773 level = ((field == AUDIT_SUBJ_SEN ||
2774 field == AUDIT_OBJ_LEV_LOW) ?
2775 &ctxt->range.level[0] : &ctxt->range.level[1]);
2776 switch (op) {
2777 case Audit_equal:
2778 match = mls_level_eq(&rule->au_ctxt.range.level[0],
2779 level);
2780 break;
2781 case Audit_not_equal:
2782 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2783 level);
2784 break;
2785 case Audit_lt:
2786 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2787 level) &&
2788 !mls_level_eq(&rule->au_ctxt.range.level[0],
2789 level));
2790 break;
2791 case Audit_le:
2792 match = mls_level_dom(&rule->au_ctxt.range.level[0],
2793 level);
2794 break;
2795 case Audit_gt:
2796 match = (mls_level_dom(level,
2797 &rule->au_ctxt.range.level[0]) &&
2798 !mls_level_eq(level,
2799 &rule->au_ctxt.range.level[0]));
2800 break;
2801 case Audit_ge:
2802 match = mls_level_dom(level,
2803 &rule->au_ctxt.range.level[0]);
2804 break;
2805 }
2806 }
2807
2808 out:
2809 read_unlock(&policy_rwlock);
2810 return match;
2811 }
2812
2813 static int (*aurule_callback)(void) = audit_update_lsm_rules;
2814
aurule_avc_callback(u32 event,u32 ssid,u32 tsid,u16 class,u32 perms,u32 * retained)2815 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2816 u16 class, u32 perms, u32 *retained)
2817 {
2818 int err = 0;
2819
2820 if (event == AVC_CALLBACK_RESET && aurule_callback)
2821 err = aurule_callback();
2822 return err;
2823 }
2824
aurule_init(void)2825 static int __init aurule_init(void)
2826 {
2827 int err;
2828
2829 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2830 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2831 if (err)
2832 panic("avc_add_callback() failed, error %d\n", err);
2833
2834 return err;
2835 }
2836 __initcall(aurule_init);
2837
2838 #ifdef CONFIG_NETLABEL
2839 /**
2840 * security_netlbl_cache_add - Add an entry to the NetLabel cache
2841 * @secattr: the NetLabel packet security attributes
2842 * @sid: the SELinux SID
2843 *
2844 * Description:
2845 * Attempt to cache the context in @ctx, which was derived from the packet in
2846 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
2847 * already been initialized.
2848 *
2849 */
security_netlbl_cache_add(struct netlbl_lsm_secattr * secattr,u32 sid)2850 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
2851 u32 sid)
2852 {
2853 u32 *sid_cache;
2854
2855 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
2856 if (sid_cache == NULL)
2857 return;
2858 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2859 if (secattr->cache == NULL) {
2860 kfree(sid_cache);
2861 return;
2862 }
2863
2864 *sid_cache = sid;
2865 secattr->cache->free = kfree;
2866 secattr->cache->data = sid_cache;
2867 secattr->flags |= NETLBL_SECATTR_CACHE;
2868 }
2869
2870 /**
2871 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2872 * @secattr: the NetLabel packet security attributes
2873 * @sid: the SELinux SID
2874 *
2875 * Description:
2876 * Convert the given NetLabel security attributes in @secattr into a
2877 * SELinux SID. If the @secattr field does not contain a full SELinux
2878 * SID/context then use SECINITSID_NETMSG as the foundation. If possibile the
2879 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
2880 * allow the @secattr to be used by NetLabel to cache the secattr to SID
2881 * conversion for future lookups. Returns zero on success, negative values on
2882 * failure.
2883 *
2884 */
security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr * secattr,u32 * sid)2885 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
2886 u32 *sid)
2887 {
2888 int rc = -EIDRM;
2889 struct context *ctx;
2890 struct context ctx_new;
2891
2892 if (!ss_initialized) {
2893 *sid = SECSID_NULL;
2894 return 0;
2895 }
2896
2897 read_lock(&policy_rwlock);
2898
2899 if (secattr->flags & NETLBL_SECATTR_CACHE) {
2900 *sid = *(u32 *)secattr->cache->data;
2901 rc = 0;
2902 } else if (secattr->flags & NETLBL_SECATTR_SECID) {
2903 *sid = secattr->attr.secid;
2904 rc = 0;
2905 } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2906 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
2907 if (ctx == NULL)
2908 goto netlbl_secattr_to_sid_return;
2909
2910 context_init(&ctx_new);
2911 ctx_new.user = ctx->user;
2912 ctx_new.role = ctx->role;
2913 ctx_new.type = ctx->type;
2914 mls_import_netlbl_lvl(&ctx_new, secattr);
2915 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2916 if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
2917 secattr->attr.mls.cat) != 0)
2918 goto netlbl_secattr_to_sid_return;
2919 memcpy(&ctx_new.range.level[1].cat,
2920 &ctx_new.range.level[0].cat,
2921 sizeof(ctx_new.range.level[0].cat));
2922 }
2923 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2924 goto netlbl_secattr_to_sid_return_cleanup;
2925
2926 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2927 if (rc != 0)
2928 goto netlbl_secattr_to_sid_return_cleanup;
2929
2930 security_netlbl_cache_add(secattr, *sid);
2931
2932 ebitmap_destroy(&ctx_new.range.level[0].cat);
2933 } else {
2934 *sid = SECSID_NULL;
2935 rc = 0;
2936 }
2937
2938 netlbl_secattr_to_sid_return:
2939 read_unlock(&policy_rwlock);
2940 return rc;
2941 netlbl_secattr_to_sid_return_cleanup:
2942 ebitmap_destroy(&ctx_new.range.level[0].cat);
2943 goto netlbl_secattr_to_sid_return;
2944 }
2945
2946 /**
2947 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
2948 * @sid: the SELinux SID
2949 * @secattr: the NetLabel packet security attributes
2950 *
2951 * Description:
2952 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
2953 * Returns zero on success, negative values on failure.
2954 *
2955 */
security_netlbl_sid_to_secattr(u32 sid,struct netlbl_lsm_secattr * secattr)2956 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
2957 {
2958 int rc;
2959 struct context *ctx;
2960
2961 if (!ss_initialized)
2962 return 0;
2963
2964 read_lock(&policy_rwlock);
2965 ctx = sidtab_search(&sidtab, sid);
2966 if (ctx == NULL) {
2967 rc = -ENOENT;
2968 goto netlbl_sid_to_secattr_failure;
2969 }
2970 secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
2971 GFP_ATOMIC);
2972 if (secattr->domain == NULL) {
2973 rc = -ENOMEM;
2974 goto netlbl_sid_to_secattr_failure;
2975 }
2976 secattr->attr.secid = sid;
2977 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
2978 mls_export_netlbl_lvl(ctx, secattr);
2979 rc = mls_export_netlbl_cat(ctx, secattr);
2980 if (rc != 0)
2981 goto netlbl_sid_to_secattr_failure;
2982 read_unlock(&policy_rwlock);
2983
2984 return 0;
2985
2986 netlbl_sid_to_secattr_failure:
2987 read_unlock(&policy_rwlock);
2988 return rc;
2989 }
2990 #endif /* CONFIG_NETLABEL */
2991