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