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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 convert_context_args {
72 struct selinux_state *state;
73 struct policydb *oldp;
74 struct policydb *newp;
75};
76
77struct selinux_policy_convert_data {
78 struct convert_context_args args;
79 struct sidtab_convert_params sidtab_params;
80};
81
82/* Forward declaration. */
83static int context_struct_to_string(struct policydb *policydb,
84 struct context *context,
85 char **scontext,
86 u32 *scontext_len);
87
88static int sidtab_entry_to_string(struct policydb *policydb,
89 struct sidtab *sidtab,
90 struct sidtab_entry *entry,
91 char **scontext,
92 u32 *scontext_len);
93
94static void context_struct_compute_av(struct policydb *policydb,
95 struct context *scontext,
96 struct context *tcontext,
97 u16 tclass,
98 struct av_decision *avd,
99 struct extended_perms *xperms);
100
101static int selinux_set_mapping(struct policydb *pol,
102 struct security_class_mapping *map,
103 struct selinux_map *out_map)
104{
105 u16 i, j;
106 unsigned k;
107 bool print_unknown_handle = false;
108
109 /* Find number of classes in the input mapping */
110 if (!map)
111 return -EINVAL;
112 i = 0;
113 while (map[i].name)
114 i++;
115
116 /* Allocate space for the class records, plus one for class zero */
117 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
118 if (!out_map->mapping)
119 return -ENOMEM;
120
121 /* Store the raw class and permission values */
122 j = 0;
123 while (map[j].name) {
124 struct security_class_mapping *p_in = map + (j++);
125 struct selinux_mapping *p_out = out_map->mapping + j;
126
127 /* An empty class string skips ahead */
128 if (!strcmp(p_in->name, "")) {
129 p_out->num_perms = 0;
130 continue;
131 }
132
133 p_out->value = string_to_security_class(pol, p_in->name);
134 if (!p_out->value) {
135 pr_info("SELinux: Class %s not defined in policy.\n",
136 p_in->name);
137 if (pol->reject_unknown)
138 goto err;
139 p_out->num_perms = 0;
140 print_unknown_handle = true;
141 continue;
142 }
143
144 k = 0;
145 while (p_in->perms[k]) {
146 /* An empty permission string skips ahead */
147 if (!*p_in->perms[k]) {
148 k++;
149 continue;
150 }
151 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
152 p_in->perms[k]);
153 if (!p_out->perms[k]) {
154 pr_info("SELinux: Permission %s in class %s not defined in policy.\n",
155 p_in->perms[k], p_in->name);
156 if (pol->reject_unknown)
157 goto err;
158 print_unknown_handle = true;
159 }
160
161 k++;
162 }
163 p_out->num_perms = k;
164 }
165
166 if (print_unknown_handle)
167 pr_info("SELinux: the above unknown classes and permissions will be %s\n",
168 pol->allow_unknown ? "allowed" : "denied");
169
170 out_map->size = i;
171 return 0;
172err:
173 kfree(out_map->mapping);
174 out_map->mapping = NULL;
175 return -EINVAL;
176}
177
178/*
179 * Get real, policy values from mapped values
180 */
181
182static u16 unmap_class(struct selinux_map *map, u16 tclass)
183{
184 if (tclass < map->size)
185 return map->mapping[tclass].value;
186
187 return tclass;
188}
189
190/*
191 * Get kernel value for class from its policy value
192 */
193static u16 map_class(struct selinux_map *map, u16 pol_value)
194{
195 u16 i;
196
197 for (i = 1; i < map->size; i++) {
198 if (map->mapping[i].value == pol_value)
199 return i;
200 }
201
202 return SECCLASS_NULL;
203}
204
205static void map_decision(struct selinux_map *map,
206 u16 tclass, struct av_decision *avd,
207 int allow_unknown)
208{
209 if (tclass < map->size) {
210 struct selinux_mapping *mapping = &map->mapping[tclass];
211 unsigned int i, n = mapping->num_perms;
212 u32 result;
213
214 for (i = 0, result = 0; i < n; i++) {
215 if (avd->allowed & mapping->perms[i])
216 result |= 1<<i;
217 if (allow_unknown && !mapping->perms[i])
218 result |= 1<<i;
219 }
220 avd->allowed = result;
221
222 for (i = 0, result = 0; i < n; i++)
223 if (avd->auditallow & mapping->perms[i])
224 result |= 1<<i;
225 avd->auditallow = result;
226
227 for (i = 0, result = 0; i < n; i++) {
228 if (avd->auditdeny & mapping->perms[i])
229 result |= 1<<i;
230 if (!allow_unknown && !mapping->perms[i])
231 result |= 1<<i;
232 }
233 /*
234 * In case the kernel has a bug and requests a permission
235 * between num_perms and the maximum permission number, we
236 * should audit that denial
237 */
238 for (; i < (sizeof(u32)*8); i++)
239 result |= 1<<i;
240 avd->auditdeny = result;
241 }
242}
243
244int security_mls_enabled(struct selinux_state *state)
245{
246 int mls_enabled;
247 struct selinux_policy *policy;
248
249 if (!selinux_initialized(state))
250 return 0;
251
252 rcu_read_lock();
253 policy = rcu_dereference(state->policy);
254 mls_enabled = policy->policydb.mls_enabled;
255 rcu_read_unlock();
256 return 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 policydb *policydb,
271 struct context *scontext,
272 struct context *tcontext,
273 struct context *xcontext,
274 struct constraint_expr *cexpr)
275{
276 u32 val1, val2;
277 struct context *c;
278 struct role_datum *r1, *r2;
279 struct mls_level *l1, *l2;
280 struct constraint_expr *e;
281 int s[CEXPR_MAXDEPTH];
282 int sp = -1;
283
284 for (e = cexpr; e; e = e->next) {
285 switch (e->expr_type) {
286 case CEXPR_NOT:
287 BUG_ON(sp < 0);
288 s[sp] = !s[sp];
289 break;
290 case CEXPR_AND:
291 BUG_ON(sp < 1);
292 sp--;
293 s[sp] &= s[sp + 1];
294 break;
295 case CEXPR_OR:
296 BUG_ON(sp < 1);
297 sp--;
298 s[sp] |= s[sp + 1];
299 break;
300 case CEXPR_ATTR:
301 if (sp == (CEXPR_MAXDEPTH - 1))
302 return 0;
303 switch (e->attr) {
304 case CEXPR_USER:
305 val1 = scontext->user;
306 val2 = tcontext->user;
307 break;
308 case CEXPR_TYPE:
309 val1 = scontext->type;
310 val2 = tcontext->type;
311 break;
312 case CEXPR_ROLE:
313 val1 = scontext->role;
314 val2 = tcontext->role;
315 r1 = policydb->role_val_to_struct[val1 - 1];
316 r2 = policydb->role_val_to_struct[val2 - 1];
317 switch (e->op) {
318 case CEXPR_DOM:
319 s[++sp] = ebitmap_get_bit(&r1->dominates,
320 val2 - 1);
321 continue;
322 case CEXPR_DOMBY:
323 s[++sp] = ebitmap_get_bit(&r2->dominates,
324 val1 - 1);
325 continue;
326 case CEXPR_INCOMP:
327 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
328 val2 - 1) &&
329 !ebitmap_get_bit(&r2->dominates,
330 val1 - 1));
331 continue;
332 default:
333 break;
334 }
335 break;
336 case CEXPR_L1L2:
337 l1 = &(scontext->range.level[0]);
338 l2 = &(tcontext->range.level[0]);
339 goto mls_ops;
340 case CEXPR_L1H2:
341 l1 = &(scontext->range.level[0]);
342 l2 = &(tcontext->range.level[1]);
343 goto mls_ops;
344 case CEXPR_H1L2:
345 l1 = &(scontext->range.level[1]);
346 l2 = &(tcontext->range.level[0]);
347 goto mls_ops;
348 case CEXPR_H1H2:
349 l1 = &(scontext->range.level[1]);
350 l2 = &(tcontext->range.level[1]);
351 goto mls_ops;
352 case CEXPR_L1H1:
353 l1 = &(scontext->range.level[0]);
354 l2 = &(scontext->range.level[1]);
355 goto mls_ops;
356 case CEXPR_L2H2:
357 l1 = &(tcontext->range.level[0]);
358 l2 = &(tcontext->range.level[1]);
359 goto mls_ops;
360mls_ops:
361 switch (e->op) {
362 case CEXPR_EQ:
363 s[++sp] = mls_level_eq(l1, l2);
364 continue;
365 case CEXPR_NEQ:
366 s[++sp] = !mls_level_eq(l1, l2);
367 continue;
368 case CEXPR_DOM:
369 s[++sp] = mls_level_dom(l1, l2);
370 continue;
371 case CEXPR_DOMBY:
372 s[++sp] = mls_level_dom(l2, l1);
373 continue;
374 case CEXPR_INCOMP:
375 s[++sp] = mls_level_incomp(l2, l1);
376 continue;
377 default:
378 BUG();
379 return 0;
380 }
381 break;
382 default:
383 BUG();
384 return 0;
385 }
386
387 switch (e->op) {
388 case CEXPR_EQ:
389 s[++sp] = (val1 == val2);
390 break;
391 case CEXPR_NEQ:
392 s[++sp] = (val1 != val2);
393 break;
394 default:
395 BUG();
396 return 0;
397 }
398 break;
399 case CEXPR_NAMES:
400 if (sp == (CEXPR_MAXDEPTH-1))
401 return 0;
402 c = scontext;
403 if (e->attr & CEXPR_TARGET)
404 c = tcontext;
405 else if (e->attr & CEXPR_XTARGET) {
406 c = xcontext;
407 if (!c) {
408 BUG();
409 return 0;
410 }
411 }
412 if (e->attr & CEXPR_USER)
413 val1 = c->user;
414 else if (e->attr & CEXPR_ROLE)
415 val1 = c->role;
416 else if (e->attr & CEXPR_TYPE)
417 val1 = c->type;
418 else {
419 BUG();
420 return 0;
421 }
422
423 switch (e->op) {
424 case CEXPR_EQ:
425 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
426 break;
427 case CEXPR_NEQ:
428 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
429 break;
430 default:
431 BUG();
432 return 0;
433 }
434 break;
435 default:
436 BUG();
437 return 0;
438 }
439 }
440
441 BUG_ON(sp != 0);
442 return s[0];
443}
444
445/*
446 * security_dump_masked_av - dumps masked permissions during
447 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
448 */
449static int dump_masked_av_helper(void *k, void *d, void *args)
450{
451 struct perm_datum *pdatum = d;
452 char **permission_names = args;
453
454 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
455
456 permission_names[pdatum->value - 1] = (char *)k;
457
458 return 0;
459}
460
461static void security_dump_masked_av(struct policydb *policydb,
462 struct context *scontext,
463 struct context *tcontext,
464 u16 tclass,
465 u32 permissions,
466 const char *reason)
467{
468 struct common_datum *common_dat;
469 struct class_datum *tclass_dat;
470 struct audit_buffer *ab;
471 char *tclass_name;
472 char *scontext_name = NULL;
473 char *tcontext_name = NULL;
474 char *permission_names[32];
475 int index;
476 u32 length;
477 bool need_comma = false;
478
479 if (!permissions)
480 return;
481
482 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
483 tclass_dat = policydb->class_val_to_struct[tclass - 1];
484 common_dat = tclass_dat->comdatum;
485
486 /* init permission_names */
487 if (common_dat &&
488 hashtab_map(&common_dat->permissions.table,
489 dump_masked_av_helper, permission_names) < 0)
490 goto out;
491
492 if (hashtab_map(&tclass_dat->permissions.table,
493 dump_masked_av_helper, permission_names) < 0)
494 goto out;
495
496 /* get scontext/tcontext in text form */
497 if (context_struct_to_string(policydb, scontext,
498 &scontext_name, &length) < 0)
499 goto out;
500
501 if (context_struct_to_string(policydb, tcontext,
502 &tcontext_name, &length) < 0)
503 goto out;
504
505 /* audit a message */
506 ab = audit_log_start(audit_context(),
507 GFP_ATOMIC, AUDIT_SELINUX_ERR);
508 if (!ab)
509 goto out;
510
511 audit_log_format(ab, "op=security_compute_av reason=%s "
512 "scontext=%s tcontext=%s tclass=%s perms=",
513 reason, scontext_name, tcontext_name, tclass_name);
514
515 for (index = 0; index < 32; index++) {
516 u32 mask = (1 << index);
517
518 if ((mask & permissions) == 0)
519 continue;
520
521 audit_log_format(ab, "%s%s",
522 need_comma ? "," : "",
523 permission_names[index]
524 ? permission_names[index] : "????");
525 need_comma = true;
526 }
527 audit_log_end(ab);
528out:
529 /* release scontext/tcontext */
530 kfree(tcontext_name);
531 kfree(scontext_name);
532
533 return;
534}
535
536/*
537 * security_boundary_permission - drops violated permissions
538 * on boundary constraint.
539 */
540static void type_attribute_bounds_av(struct policydb *policydb,
541 struct context *scontext,
542 struct context *tcontext,
543 u16 tclass,
544 struct av_decision *avd)
545{
546 struct context lo_scontext;
547 struct context lo_tcontext, *tcontextp = tcontext;
548 struct av_decision lo_avd;
549 struct type_datum *source;
550 struct type_datum *target;
551 u32 masked = 0;
552
553 source = policydb->type_val_to_struct[scontext->type - 1];
554 BUG_ON(!source);
555
556 if (!source->bounds)
557 return;
558
559 target = policydb->type_val_to_struct[tcontext->type - 1];
560 BUG_ON(!target);
561
562 memset(&lo_avd, 0, sizeof(lo_avd));
563
564 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
565 lo_scontext.type = source->bounds;
566
567 if (target->bounds) {
568 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
569 lo_tcontext.type = target->bounds;
570 tcontextp = &lo_tcontext;
571 }
572
573 context_struct_compute_av(policydb, &lo_scontext,
574 tcontextp,
575 tclass,
576 &lo_avd,
577 NULL);
578
579 masked = ~lo_avd.allowed & avd->allowed;
580
581 if (likely(!masked))
582 return; /* no masked permission */
583
584 /* mask violated permissions */
585 avd->allowed &= ~masked;
586
587 /* audit masked permissions */
588 security_dump_masked_av(policydb, scontext, tcontext,
589 tclass, masked, "bounds");
590}
591
592/*
593 * flag which drivers have permissions
594 * only looking for ioctl based extended permssions
595 */
596void services_compute_xperms_drivers(
597 struct extended_perms *xperms,
598 struct avtab_node *node)
599{
600 unsigned int i;
601
602 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
603 /* if one or more driver has all permissions allowed */
604 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
605 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
606 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
607 /* if allowing permissions within a driver */
608 security_xperm_set(xperms->drivers.p,
609 node->datum.u.xperms->driver);
610 }
611
612 xperms->len = 1;
613}
614
615/*
616 * Compute access vectors and extended permissions based on a context
617 * structure pair for the permissions in a particular class.
618 */
619static void context_struct_compute_av(struct policydb *policydb,
620 struct context *scontext,
621 struct context *tcontext,
622 u16 tclass,
623 struct av_decision *avd,
624 struct extended_perms *xperms)
625{
626 struct constraint_node *constraint;
627 struct role_allow *ra;
628 struct avtab_key avkey;
629 struct avtab_node *node;
630 struct class_datum *tclass_datum;
631 struct ebitmap *sattr, *tattr;
632 struct ebitmap_node *snode, *tnode;
633 unsigned int i, j;
634
635 avd->allowed = 0;
636 avd->auditallow = 0;
637 avd->auditdeny = 0xffffffff;
638 if (xperms) {
639 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
640 xperms->len = 0;
641 }
642
643 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
644 if (printk_ratelimit())
645 pr_warn("SELinux: Invalid class %hu\n", tclass);
646 return;
647 }
648
649 tclass_datum = policydb->class_val_to_struct[tclass - 1];
650
651 /*
652 * If a specific type enforcement rule was defined for
653 * this permission check, then use it.
654 */
655 avkey.target_class = tclass;
656 avkey.specified = AVTAB_AV | AVTAB_XPERMS;
657 sattr = &policydb->type_attr_map_array[scontext->type - 1];
658 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
659 ebitmap_for_each_positive_bit(sattr, snode, i) {
660 ebitmap_for_each_positive_bit(tattr, tnode, j) {
661 avkey.source_type = i + 1;
662 avkey.target_type = j + 1;
663 for (node = avtab_search_node(&policydb->te_avtab,
664 &avkey);
665 node;
666 node = avtab_search_node_next(node, avkey.specified)) {
667 if (node->key.specified == AVTAB_ALLOWED)
668 avd->allowed |= node->datum.u.data;
669 else if (node->key.specified == AVTAB_AUDITALLOW)
670 avd->auditallow |= node->datum.u.data;
671 else if (node->key.specified == AVTAB_AUDITDENY)
672 avd->auditdeny &= node->datum.u.data;
673 else if (xperms && (node->key.specified & AVTAB_XPERMS))
674 services_compute_xperms_drivers(xperms, node);
675 }
676
677 /* Check conditional av table for additional permissions */
678 cond_compute_av(&policydb->te_cond_avtab, &avkey,
679 avd, xperms);
680
681 }
682 }
683
684 /*
685 * Remove any permissions prohibited by a constraint (this includes
686 * the MLS policy).
687 */
688 constraint = tclass_datum->constraints;
689 while (constraint) {
690 if ((constraint->permissions & (avd->allowed)) &&
691 !constraint_expr_eval(policydb, scontext, tcontext, NULL,
692 constraint->expr)) {
693 avd->allowed &= ~(constraint->permissions);
694 }
695 constraint = constraint->next;
696 }
697
698 /*
699 * If checking process transition permission and the
700 * role is changing, then check the (current_role, new_role)
701 * pair.
702 */
703 if (tclass == policydb->process_class &&
704 (avd->allowed & policydb->process_trans_perms) &&
705 scontext->role != tcontext->role) {
706 for (ra = policydb->role_allow; ra; ra = ra->next) {
707 if (scontext->role == ra->role &&
708 tcontext->role == ra->new_role)
709 break;
710 }
711 if (!ra)
712 avd->allowed &= ~policydb->process_trans_perms;
713 }
714
715 /*
716 * If the given source and target types have boundary
717 * constraint, lazy checks have to mask any violated
718 * permission and notice it to userspace via audit.
719 */
720 type_attribute_bounds_av(policydb, scontext, tcontext,
721 tclass, avd);
722}
723
724static int security_validtrans_handle_fail(struct selinux_state *state,
725 struct selinux_policy *policy,
726 struct sidtab_entry *oentry,
727 struct sidtab_entry *nentry,
728 struct sidtab_entry *tentry,
729 u16 tclass)
730{
731 struct policydb *p = &policy->policydb;
732 struct sidtab *sidtab = policy->sidtab;
733 char *o = NULL, *n = NULL, *t = NULL;
734 u32 olen, nlen, tlen;
735
736 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
737 goto out;
738 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
739 goto out;
740 if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
741 goto out;
742 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
743 "op=security_validate_transition seresult=denied"
744 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
745 o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
746out:
747 kfree(o);
748 kfree(n);
749 kfree(t);
750
751 if (!enforcing_enabled(state))
752 return 0;
753 return -EPERM;
754}
755
756static int security_compute_validatetrans(struct selinux_state *state,
757 u32 oldsid, u32 newsid, u32 tasksid,
758 u16 orig_tclass, bool user)
759{
760 struct selinux_policy *policy;
761 struct policydb *policydb;
762 struct sidtab *sidtab;
763 struct sidtab_entry *oentry;
764 struct sidtab_entry *nentry;
765 struct sidtab_entry *tentry;
766 struct class_datum *tclass_datum;
767 struct constraint_node *constraint;
768 u16 tclass;
769 int rc = 0;
770
771
772 if (!selinux_initialized(state))
773 return 0;
774
775 rcu_read_lock();
776
777 policy = rcu_dereference(state->policy);
778 policydb = &policy->policydb;
779 sidtab = policy->sidtab;
780
781 if (!user)
782 tclass = unmap_class(&policy->map, orig_tclass);
783 else
784 tclass = orig_tclass;
785
786 if (!tclass || tclass > policydb->p_classes.nprim) {
787 rc = -EINVAL;
788 goto out;
789 }
790 tclass_datum = policydb->class_val_to_struct[tclass - 1];
791
792 oentry = sidtab_search_entry(sidtab, oldsid);
793 if (!oentry) {
794 pr_err("SELinux: %s: unrecognized SID %d\n",
795 __func__, oldsid);
796 rc = -EINVAL;
797 goto out;
798 }
799
800 nentry = sidtab_search_entry(sidtab, newsid);
801 if (!nentry) {
802 pr_err("SELinux: %s: unrecognized SID %d\n",
803 __func__, newsid);
804 rc = -EINVAL;
805 goto out;
806 }
807
808 tentry = sidtab_search_entry(sidtab, tasksid);
809 if (!tentry) {
810 pr_err("SELinux: %s: unrecognized SID %d\n",
811 __func__, tasksid);
812 rc = -EINVAL;
813 goto out;
814 }
815
816 constraint = tclass_datum->validatetrans;
817 while (constraint) {
818 if (!constraint_expr_eval(policydb, &oentry->context,
819 &nentry->context, &tentry->context,
820 constraint->expr)) {
821 if (user)
822 rc = -EPERM;
823 else
824 rc = security_validtrans_handle_fail(state,
825 policy,
826 oentry,
827 nentry,
828 tentry,
829 tclass);
830 goto out;
831 }
832 constraint = constraint->next;
833 }
834
835out:
836 rcu_read_unlock();
837 return rc;
838}
839
840int security_validate_transition_user(struct selinux_state *state,
841 u32 oldsid, u32 newsid, u32 tasksid,
842 u16 tclass)
843{
844 return security_compute_validatetrans(state, oldsid, newsid, tasksid,
845 tclass, true);
846}
847
848int security_validate_transition(struct selinux_state *state,
849 u32 oldsid, u32 newsid, u32 tasksid,
850 u16 orig_tclass)
851{
852 return security_compute_validatetrans(state, oldsid, newsid, tasksid,
853 orig_tclass, false);
854}
855
856/*
857 * security_bounded_transition - check whether the given
858 * transition is directed to bounded, or not.
859 * It returns 0, if @newsid is bounded by @oldsid.
860 * Otherwise, it returns error code.
861 *
862 * @state: SELinux state
863 * @oldsid : current security identifier
864 * @newsid : destinated security identifier
865 */
866int security_bounded_transition(struct selinux_state *state,
867 u32 old_sid, u32 new_sid)
868{
869 struct selinux_policy *policy;
870 struct policydb *policydb;
871 struct sidtab *sidtab;
872 struct sidtab_entry *old_entry, *new_entry;
873 struct type_datum *type;
874 int index;
875 int rc;
876
877 if (!selinux_initialized(state))
878 return 0;
879
880 rcu_read_lock();
881 policy = rcu_dereference(state->policy);
882 policydb = &policy->policydb;
883 sidtab = policy->sidtab;
884
885 rc = -EINVAL;
886 old_entry = sidtab_search_entry(sidtab, old_sid);
887 if (!old_entry) {
888 pr_err("SELinux: %s: unrecognized SID %u\n",
889 __func__, old_sid);
890 goto out;
891 }
892
893 rc = -EINVAL;
894 new_entry = sidtab_search_entry(sidtab, new_sid);
895 if (!new_entry) {
896 pr_err("SELinux: %s: unrecognized SID %u\n",
897 __func__, new_sid);
898 goto out;
899 }
900
901 rc = 0;
902 /* type/domain unchanged */
903 if (old_entry->context.type == new_entry->context.type)
904 goto out;
905
906 index = new_entry->context.type;
907 while (true) {
908 type = policydb->type_val_to_struct[index - 1];
909 BUG_ON(!type);
910
911 /* not bounded anymore */
912 rc = -EPERM;
913 if (!type->bounds)
914 break;
915
916 /* @newsid is bounded by @oldsid */
917 rc = 0;
918 if (type->bounds == old_entry->context.type)
919 break;
920
921 index = type->bounds;
922 }
923
924 if (rc) {
925 char *old_name = NULL;
926 char *new_name = NULL;
927 u32 length;
928
929 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
930 &old_name, &length) &&
931 !sidtab_entry_to_string(policydb, sidtab, new_entry,
932 &new_name, &length)) {
933 audit_log(audit_context(),
934 GFP_ATOMIC, AUDIT_SELINUX_ERR,
935 "op=security_bounded_transition "
936 "seresult=denied "
937 "oldcontext=%s newcontext=%s",
938 old_name, new_name);
939 }
940 kfree(new_name);
941 kfree(old_name);
942 }
943out:
944 rcu_read_unlock();
945
946 return rc;
947}
948
949static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
950{
951 avd->allowed = 0;
952 avd->auditallow = 0;
953 avd->auditdeny = 0xffffffff;
954 if (policy)
955 avd->seqno = policy->latest_granting;
956 else
957 avd->seqno = 0;
958 avd->flags = 0;
959}
960
961void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
962 struct avtab_node *node)
963{
964 unsigned int i;
965
966 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
967 if (xpermd->driver != node->datum.u.xperms->driver)
968 return;
969 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
970 if (!security_xperm_test(node->datum.u.xperms->perms.p,
971 xpermd->driver))
972 return;
973 } else {
974 BUG();
975 }
976
977 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
978 xpermd->used |= XPERMS_ALLOWED;
979 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
980 memset(xpermd->allowed->p, 0xff,
981 sizeof(xpermd->allowed->p));
982 }
983 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
984 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
985 xpermd->allowed->p[i] |=
986 node->datum.u.xperms->perms.p[i];
987 }
988 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
989 xpermd->used |= XPERMS_AUDITALLOW;
990 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
991 memset(xpermd->auditallow->p, 0xff,
992 sizeof(xpermd->auditallow->p));
993 }
994 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
995 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
996 xpermd->auditallow->p[i] |=
997 node->datum.u.xperms->perms.p[i];
998 }
999 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
1000 xpermd->used |= XPERMS_DONTAUDIT;
1001 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
1002 memset(xpermd->dontaudit->p, 0xff,
1003 sizeof(xpermd->dontaudit->p));
1004 }
1005 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
1006 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
1007 xpermd->dontaudit->p[i] |=
1008 node->datum.u.xperms->perms.p[i];
1009 }
1010 } else {
1011 BUG();
1012 }
1013}
1014
1015void security_compute_xperms_decision(struct selinux_state *state,
1016 u32 ssid,
1017 u32 tsid,
1018 u16 orig_tclass,
1019 u8 driver,
1020 struct extended_perms_decision *xpermd)
1021{
1022 struct selinux_policy *policy;
1023 struct policydb *policydb;
1024 struct sidtab *sidtab;
1025 u16 tclass;
1026 struct context *scontext, *tcontext;
1027 struct avtab_key avkey;
1028 struct avtab_node *node;
1029 struct ebitmap *sattr, *tattr;
1030 struct ebitmap_node *snode, *tnode;
1031 unsigned int i, j;
1032
1033 xpermd->driver = driver;
1034 xpermd->used = 0;
1035 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1036 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1037 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1038
1039 rcu_read_lock();
1040 if (!selinux_initialized(state))
1041 goto allow;
1042
1043 policy = rcu_dereference(state->policy);
1044 policydb = &policy->policydb;
1045 sidtab = policy->sidtab;
1046
1047 scontext = sidtab_search(sidtab, ssid);
1048 if (!scontext) {
1049 pr_err("SELinux: %s: unrecognized SID %d\n",
1050 __func__, ssid);
1051 goto out;
1052 }
1053
1054 tcontext = sidtab_search(sidtab, tsid);
1055 if (!tcontext) {
1056 pr_err("SELinux: %s: unrecognized SID %d\n",
1057 __func__, tsid);
1058 goto out;
1059 }
1060
1061 tclass = unmap_class(&policy->map, orig_tclass);
1062 if (unlikely(orig_tclass && !tclass)) {
1063 if (policydb->allow_unknown)
1064 goto allow;
1065 goto out;
1066 }
1067
1068
1069 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1070 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1071 goto out;
1072 }
1073
1074 avkey.target_class = tclass;
1075 avkey.specified = AVTAB_XPERMS;
1076 sattr = &policydb->type_attr_map_array[scontext->type - 1];
1077 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1078 ebitmap_for_each_positive_bit(sattr, snode, i) {
1079 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1080 avkey.source_type = i + 1;
1081 avkey.target_type = j + 1;
1082 for (node = avtab_search_node(&policydb->te_avtab,
1083 &avkey);
1084 node;
1085 node = avtab_search_node_next(node, avkey.specified))
1086 services_compute_xperms_decision(xpermd, node);
1087
1088 cond_compute_xperms(&policydb->te_cond_avtab,
1089 &avkey, xpermd);
1090 }
1091 }
1092out:
1093 rcu_read_unlock();
1094 return;
1095allow:
1096 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1097 goto out;
1098}
1099
1100/**
1101 * security_compute_av - Compute access vector decisions.
1102 * @state: SELinux state
1103 * @ssid: source security identifier
1104 * @tsid: target security identifier
1105 * @tclass: target security class
1106 * @avd: access vector decisions
1107 * @xperms: extended permissions
1108 *
1109 * Compute a set of access vector decisions based on the
1110 * SID pair (@ssid, @tsid) for the permissions in @tclass.
1111 */
1112void security_compute_av(struct selinux_state *state,
1113 u32 ssid,
1114 u32 tsid,
1115 u16 orig_tclass,
1116 struct av_decision *avd,
1117 struct extended_perms *xperms)
1118{
1119 struct selinux_policy *policy;
1120 struct policydb *policydb;
1121 struct sidtab *sidtab;
1122 u16 tclass;
1123 struct context *scontext = NULL, *tcontext = NULL;
1124
1125 rcu_read_lock();
1126 policy = rcu_dereference(state->policy);
1127 avd_init(policy, avd);
1128 xperms->len = 0;
1129 if (!selinux_initialized(state))
1130 goto allow;
1131
1132 policydb = &policy->policydb;
1133 sidtab = policy->sidtab;
1134
1135 scontext = sidtab_search(sidtab, ssid);
1136 if (!scontext) {
1137 pr_err("SELinux: %s: unrecognized SID %d\n",
1138 __func__, ssid);
1139 goto out;
1140 }
1141
1142 /* permissive domain? */
1143 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1144 avd->flags |= AVD_FLAGS_PERMISSIVE;
1145
1146 tcontext = sidtab_search(sidtab, tsid);
1147 if (!tcontext) {
1148 pr_err("SELinux: %s: unrecognized SID %d\n",
1149 __func__, tsid);
1150 goto out;
1151 }
1152
1153 tclass = unmap_class(&policy->map, orig_tclass);
1154 if (unlikely(orig_tclass && !tclass)) {
1155 if (policydb->allow_unknown)
1156 goto allow;
1157 goto out;
1158 }
1159 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1160 xperms);
1161 map_decision(&policy->map, orig_tclass, avd,
1162 policydb->allow_unknown);
1163out:
1164 rcu_read_unlock();
1165 return;
1166allow:
1167 avd->allowed = 0xffffffff;
1168 goto out;
1169}
1170
1171void security_compute_av_user(struct selinux_state *state,
1172 u32 ssid,
1173 u32 tsid,
1174 u16 tclass,
1175 struct av_decision *avd)
1176{
1177 struct selinux_policy *policy;
1178 struct policydb *policydb;
1179 struct sidtab *sidtab;
1180 struct context *scontext = NULL, *tcontext = NULL;
1181
1182 rcu_read_lock();
1183 policy = rcu_dereference(state->policy);
1184 avd_init(policy, avd);
1185 if (!selinux_initialized(state))
1186 goto allow;
1187
1188 policydb = &policy->policydb;
1189 sidtab = policy->sidtab;
1190
1191 scontext = sidtab_search(sidtab, ssid);
1192 if (!scontext) {
1193 pr_err("SELinux: %s: unrecognized SID %d\n",
1194 __func__, ssid);
1195 goto out;
1196 }
1197
1198 /* permissive domain? */
1199 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1200 avd->flags |= AVD_FLAGS_PERMISSIVE;
1201
1202 tcontext = sidtab_search(sidtab, tsid);
1203 if (!tcontext) {
1204 pr_err("SELinux: %s: unrecognized SID %d\n",
1205 __func__, tsid);
1206 goto out;
1207 }
1208
1209 if (unlikely(!tclass)) {
1210 if (policydb->allow_unknown)
1211 goto allow;
1212 goto out;
1213 }
1214
1215 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1216 NULL);
1217 out:
1218 rcu_read_unlock();
1219 return;
1220allow:
1221 avd->allowed = 0xffffffff;
1222 goto out;
1223}
1224
1225/*
1226 * Write the security context string representation of
1227 * the context structure `context' into a dynamically
1228 * allocated string of the correct size. Set `*scontext'
1229 * to point to this string and set `*scontext_len' to
1230 * the length of the string.
1231 */
1232static int context_struct_to_string(struct policydb *p,
1233 struct context *context,
1234 char **scontext, u32 *scontext_len)
1235{
1236 char *scontextp;
1237
1238 if (scontext)
1239 *scontext = NULL;
1240 *scontext_len = 0;
1241
1242 if (context->len) {
1243 *scontext_len = context->len;
1244 if (scontext) {
1245 *scontext = kstrdup(context->str, GFP_ATOMIC);
1246 if (!(*scontext))
1247 return -ENOMEM;
1248 }
1249 return 0;
1250 }
1251
1252 /* Compute the size of the context. */
1253 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1254 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1255 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1256 *scontext_len += mls_compute_context_len(p, context);
1257
1258 if (!scontext)
1259 return 0;
1260
1261 /* Allocate space for the context; caller must free this space. */
1262 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1263 if (!scontextp)
1264 return -ENOMEM;
1265 *scontext = scontextp;
1266
1267 /*
1268 * Copy the user name, role name and type name into the context.
1269 */
1270 scontextp += sprintf(scontextp, "%s:%s:%s",
1271 sym_name(p, SYM_USERS, context->user - 1),
1272 sym_name(p, SYM_ROLES, context->role - 1),
1273 sym_name(p, SYM_TYPES, context->type - 1));
1274
1275 mls_sid_to_context(p, context, &scontextp);
1276
1277 *scontextp = 0;
1278
1279 return 0;
1280}
1281
1282static int sidtab_entry_to_string(struct policydb *p,
1283 struct sidtab *sidtab,
1284 struct sidtab_entry *entry,
1285 char **scontext, u32 *scontext_len)
1286{
1287 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1288
1289 if (rc != -ENOENT)
1290 return rc;
1291
1292 rc = context_struct_to_string(p, &entry->context, scontext,
1293 scontext_len);
1294 if (!rc && scontext)
1295 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1296 return rc;
1297}
1298
1299#include "initial_sid_to_string.h"
1300
1301int security_sidtab_hash_stats(struct selinux_state *state, char *page)
1302{
1303 struct selinux_policy *policy;
1304 int rc;
1305
1306 if (!selinux_initialized(state)) {
1307 pr_err("SELinux: %s: called before initial load_policy\n",
1308 __func__);
1309 return -EINVAL;
1310 }
1311
1312 rcu_read_lock();
1313 policy = rcu_dereference(state->policy);
1314 rc = sidtab_hash_stats(policy->sidtab, page);
1315 rcu_read_unlock();
1316
1317 return rc;
1318}
1319
1320const char *security_get_initial_sid_context(u32 sid)
1321{
1322 if (unlikely(sid > SECINITSID_NUM))
1323 return NULL;
1324 return initial_sid_to_string[sid];
1325}
1326
1327static int security_sid_to_context_core(struct selinux_state *state,
1328 u32 sid, char **scontext,
1329 u32 *scontext_len, int force,
1330 int only_invalid)
1331{
1332 struct selinux_policy *policy;
1333 struct policydb *policydb;
1334 struct sidtab *sidtab;
1335 struct sidtab_entry *entry;
1336 int rc = 0;
1337
1338 if (scontext)
1339 *scontext = NULL;
1340 *scontext_len = 0;
1341
1342 if (!selinux_initialized(state)) {
1343 if (sid <= SECINITSID_NUM) {
1344 char *scontextp;
1345 const char *s = initial_sid_to_string[sid];
1346
1347 if (!s)
1348 return -EINVAL;
1349 *scontext_len = strlen(s) + 1;
1350 if (!scontext)
1351 return 0;
1352 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1353 if (!scontextp)
1354 return -ENOMEM;
1355 *scontext = scontextp;
1356 return 0;
1357 }
1358 pr_err("SELinux: %s: called before initial "
1359 "load_policy on unknown SID %d\n", __func__, sid);
1360 return -EINVAL;
1361 }
1362 rcu_read_lock();
1363 policy = rcu_dereference(state->policy);
1364 policydb = &policy->policydb;
1365 sidtab = policy->sidtab;
1366
1367 if (force)
1368 entry = sidtab_search_entry_force(sidtab, sid);
1369 else
1370 entry = sidtab_search_entry(sidtab, sid);
1371 if (!entry) {
1372 pr_err("SELinux: %s: unrecognized SID %d\n",
1373 __func__, sid);
1374 rc = -EINVAL;
1375 goto out_unlock;
1376 }
1377 if (only_invalid && !entry->context.len)
1378 goto out_unlock;
1379
1380 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1381 scontext_len);
1382
1383out_unlock:
1384 rcu_read_unlock();
1385 return rc;
1386
1387}
1388
1389/**
1390 * security_sid_to_context - Obtain a context for a given SID.
1391 * @state: SELinux state
1392 * @sid: security identifier, SID
1393 * @scontext: security context
1394 * @scontext_len: length in bytes
1395 *
1396 * Write the string representation of the context associated with @sid
1397 * into a dynamically allocated string of the correct size. Set @scontext
1398 * to point to this string and set @scontext_len to the length of the string.
1399 */
1400int security_sid_to_context(struct selinux_state *state,
1401 u32 sid, char **scontext, u32 *scontext_len)
1402{
1403 return security_sid_to_context_core(state, sid, scontext,
1404 scontext_len, 0, 0);
1405}
1406
1407int security_sid_to_context_force(struct selinux_state *state, u32 sid,
1408 char **scontext, u32 *scontext_len)
1409{
1410 return security_sid_to_context_core(state, sid, scontext,
1411 scontext_len, 1, 0);
1412}
1413
1414/**
1415 * security_sid_to_context_inval - Obtain a context for a given SID if it
1416 * is invalid.
1417 * @state: SELinux state
1418 * @sid: security identifier, SID
1419 * @scontext: security context
1420 * @scontext_len: length in bytes
1421 *
1422 * Write the string representation of the context associated with @sid
1423 * into a dynamically allocated string of the correct size, but only if the
1424 * context is invalid in the current policy. Set @scontext to point to
1425 * this string (or NULL if the context is valid) and set @scontext_len to
1426 * the length of the string (or 0 if the context is valid).
1427 */
1428int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
1429 char **scontext, u32 *scontext_len)
1430{
1431 return security_sid_to_context_core(state, sid, scontext,
1432 scontext_len, 1, 1);
1433}
1434
1435/*
1436 * Caveat: Mutates scontext.
1437 */
1438static int string_to_context_struct(struct policydb *pol,
1439 struct sidtab *sidtabp,
1440 char *scontext,
1441 struct context *ctx,
1442 u32 def_sid)
1443{
1444 struct role_datum *role;
1445 struct type_datum *typdatum;
1446 struct user_datum *usrdatum;
1447 char *scontextp, *p, oldc;
1448 int rc = 0;
1449
1450 context_init(ctx);
1451
1452 /* Parse the security context. */
1453
1454 rc = -EINVAL;
1455 scontextp = (char *) scontext;
1456
1457 /* Extract the user. */
1458 p = scontextp;
1459 while (*p && *p != ':')
1460 p++;
1461
1462 if (*p == 0)
1463 goto out;
1464
1465 *p++ = 0;
1466
1467 usrdatum = symtab_search(&pol->p_users, scontextp);
1468 if (!usrdatum)
1469 goto out;
1470
1471 ctx->user = usrdatum->value;
1472
1473 /* Extract role. */
1474 scontextp = p;
1475 while (*p && *p != ':')
1476 p++;
1477
1478 if (*p == 0)
1479 goto out;
1480
1481 *p++ = 0;
1482
1483 role = symtab_search(&pol->p_roles, scontextp);
1484 if (!role)
1485 goto out;
1486 ctx->role = role->value;
1487
1488 /* Extract type. */
1489 scontextp = p;
1490 while (*p && *p != ':')
1491 p++;
1492 oldc = *p;
1493 *p++ = 0;
1494
1495 typdatum = symtab_search(&pol->p_types, scontextp);
1496 if (!typdatum || typdatum->attribute)
1497 goto out;
1498
1499 ctx->type = typdatum->value;
1500
1501 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1502 if (rc)
1503 goto out;
1504
1505 /* Check the validity of the new context. */
1506 rc = -EINVAL;
1507 if (!policydb_context_isvalid(pol, ctx))
1508 goto out;
1509 rc = 0;
1510out:
1511 if (rc)
1512 context_destroy(ctx);
1513 return rc;
1514}
1515
1516static int security_context_to_sid_core(struct selinux_state *state,
1517 const char *scontext, u32 scontext_len,
1518 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1519 int force)
1520{
1521 struct selinux_policy *policy;
1522 struct policydb *policydb;
1523 struct sidtab *sidtab;
1524 char *scontext2, *str = NULL;
1525 struct context context;
1526 int rc = 0;
1527
1528 /* An empty security context is never valid. */
1529 if (!scontext_len)
1530 return -EINVAL;
1531
1532 /* Copy the string to allow changes and ensure a NUL terminator */
1533 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1534 if (!scontext2)
1535 return -ENOMEM;
1536
1537 if (!selinux_initialized(state)) {
1538 int i;
1539
1540 for (i = 1; i < SECINITSID_NUM; i++) {
1541 const char *s = initial_sid_to_string[i];
1542
1543 if (s && !strcmp(s, scontext2)) {
1544 *sid = i;
1545 goto out;
1546 }
1547 }
1548 *sid = SECINITSID_KERNEL;
1549 goto out;
1550 }
1551 *sid = SECSID_NULL;
1552
1553 if (force) {
1554 /* Save another copy for storing in uninterpreted form */
1555 rc = -ENOMEM;
1556 str = kstrdup(scontext2, gfp_flags);
1557 if (!str)
1558 goto out;
1559 }
1560retry:
1561 rcu_read_lock();
1562 policy = rcu_dereference(state->policy);
1563 policydb = &policy->policydb;
1564 sidtab = policy->sidtab;
1565 rc = string_to_context_struct(policydb, sidtab, scontext2,
1566 &context, def_sid);
1567 if (rc == -EINVAL && force) {
1568 context.str = str;
1569 context.len = strlen(str) + 1;
1570 str = NULL;
1571 } else if (rc)
1572 goto out_unlock;
1573 rc = sidtab_context_to_sid(sidtab, &context, sid);
1574 if (rc == -ESTALE) {
1575 rcu_read_unlock();
1576 if (context.str) {
1577 str = context.str;
1578 context.str = NULL;
1579 }
1580 context_destroy(&context);
1581 goto retry;
1582 }
1583 context_destroy(&context);
1584out_unlock:
1585 rcu_read_unlock();
1586out:
1587 kfree(scontext2);
1588 kfree(str);
1589 return rc;
1590}
1591
1592/**
1593 * security_context_to_sid - Obtain a SID for a given security context.
1594 * @state: SELinux state
1595 * @scontext: security context
1596 * @scontext_len: length in bytes
1597 * @sid: security identifier, SID
1598 * @gfp: context for the allocation
1599 *
1600 * Obtains a SID associated with the security context that
1601 * has the string representation specified by @scontext.
1602 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1603 * memory is available, or 0 on success.
1604 */
1605int security_context_to_sid(struct selinux_state *state,
1606 const char *scontext, u32 scontext_len, u32 *sid,
1607 gfp_t gfp)
1608{
1609 return security_context_to_sid_core(state, scontext, scontext_len,
1610 sid, SECSID_NULL, gfp, 0);
1611}
1612
1613int security_context_str_to_sid(struct selinux_state *state,
1614 const char *scontext, u32 *sid, gfp_t gfp)
1615{
1616 return security_context_to_sid(state, scontext, strlen(scontext),
1617 sid, gfp);
1618}
1619
1620/**
1621 * security_context_to_sid_default - Obtain a SID for a given security context,
1622 * falling back to specified default if needed.
1623 *
1624 * @state: SELinux state
1625 * @scontext: security context
1626 * @scontext_len: length in bytes
1627 * @sid: security identifier, SID
1628 * @def_sid: default SID to assign on error
1629 *
1630 * Obtains a SID associated with the security context that
1631 * has the string representation specified by @scontext.
1632 * The default SID is passed to the MLS layer to be used to allow
1633 * kernel labeling of the MLS field if the MLS field is not present
1634 * (for upgrading to MLS without full relabel).
1635 * Implicitly forces adding of the context even if it cannot be mapped yet.
1636 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1637 * memory is available, or 0 on success.
1638 */
1639int security_context_to_sid_default(struct selinux_state *state,
1640 const char *scontext, u32 scontext_len,
1641 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1642{
1643 return security_context_to_sid_core(state, scontext, scontext_len,
1644 sid, def_sid, gfp_flags, 1);
1645}
1646
1647int security_context_to_sid_force(struct selinux_state *state,
1648 const char *scontext, u32 scontext_len,
1649 u32 *sid)
1650{
1651 return security_context_to_sid_core(state, scontext, scontext_len,
1652 sid, SECSID_NULL, GFP_KERNEL, 1);
1653}
1654
1655static int compute_sid_handle_invalid_context(
1656 struct selinux_state *state,
1657 struct selinux_policy *policy,
1658 struct sidtab_entry *sentry,
1659 struct sidtab_entry *tentry,
1660 u16 tclass,
1661 struct context *newcontext)
1662{
1663 struct policydb *policydb = &policy->policydb;
1664 struct sidtab *sidtab = policy->sidtab;
1665 char *s = NULL, *t = NULL, *n = NULL;
1666 u32 slen, tlen, nlen;
1667 struct audit_buffer *ab;
1668
1669 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1670 goto out;
1671 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1672 goto out;
1673 if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1674 goto out;
1675 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1676 audit_log_format(ab,
1677 "op=security_compute_sid invalid_context=");
1678 /* no need to record the NUL with untrusted strings */
1679 audit_log_n_untrustedstring(ab, n, nlen - 1);
1680 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1681 s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1682 audit_log_end(ab);
1683out:
1684 kfree(s);
1685 kfree(t);
1686 kfree(n);
1687 if (!enforcing_enabled(state))
1688 return 0;
1689 return -EACCES;
1690}
1691
1692static void filename_compute_type(struct policydb *policydb,
1693 struct context *newcontext,
1694 u32 stype, u32 ttype, u16 tclass,
1695 const char *objname)
1696{
1697 struct filename_trans_key ft;
1698 struct filename_trans_datum *datum;
1699
1700 /*
1701 * Most filename trans rules are going to live in specific directories
1702 * like /dev or /var/run. This bitmap will quickly skip rule searches
1703 * if the ttype does not contain any rules.
1704 */
1705 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1706 return;
1707
1708 ft.ttype = ttype;
1709 ft.tclass = tclass;
1710 ft.name = objname;
1711
1712 datum = policydb_filenametr_search(policydb, &ft);
1713 while (datum) {
1714 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1715 newcontext->type = datum->otype;
1716 return;
1717 }
1718 datum = datum->next;
1719 }
1720}
1721
1722static int security_compute_sid(struct selinux_state *state,
1723 u32 ssid,
1724 u32 tsid,
1725 u16 orig_tclass,
1726 u32 specified,
1727 const char *objname,
1728 u32 *out_sid,
1729 bool kern)
1730{
1731 struct selinux_policy *policy;
1732 struct policydb *policydb;
1733 struct sidtab *sidtab;
1734 struct class_datum *cladatum;
1735 struct context *scontext, *tcontext, newcontext;
1736 struct sidtab_entry *sentry, *tentry;
1737 struct avtab_key avkey;
1738 struct avtab_datum *avdatum;
1739 struct avtab_node *node;
1740 u16 tclass;
1741 int rc = 0;
1742 bool sock;
1743
1744 if (!selinux_initialized(state)) {
1745 switch (orig_tclass) {
1746 case SECCLASS_PROCESS: /* kernel value */
1747 *out_sid = ssid;
1748 break;
1749 default:
1750 *out_sid = tsid;
1751 break;
1752 }
1753 goto out;
1754 }
1755
1756retry:
1757 cladatum = NULL;
1758 context_init(&newcontext);
1759
1760 rcu_read_lock();
1761
1762 policy = rcu_dereference(state->policy);
1763
1764 if (kern) {
1765 tclass = unmap_class(&policy->map, orig_tclass);
1766 sock = security_is_socket_class(orig_tclass);
1767 } else {
1768 tclass = orig_tclass;
1769 sock = security_is_socket_class(map_class(&policy->map,
1770 tclass));
1771 }
1772
1773 policydb = &policy->policydb;
1774 sidtab = policy->sidtab;
1775
1776 sentry = sidtab_search_entry(sidtab, ssid);
1777 if (!sentry) {
1778 pr_err("SELinux: %s: unrecognized SID %d\n",
1779 __func__, ssid);
1780 rc = -EINVAL;
1781 goto out_unlock;
1782 }
1783 tentry = sidtab_search_entry(sidtab, tsid);
1784 if (!tentry) {
1785 pr_err("SELinux: %s: unrecognized SID %d\n",
1786 __func__, tsid);
1787 rc = -EINVAL;
1788 goto out_unlock;
1789 }
1790
1791 scontext = &sentry->context;
1792 tcontext = &tentry->context;
1793
1794 if (tclass && tclass <= policydb->p_classes.nprim)
1795 cladatum = policydb->class_val_to_struct[tclass - 1];
1796
1797 /* Set the user identity. */
1798 switch (specified) {
1799 case AVTAB_TRANSITION:
1800 case AVTAB_CHANGE:
1801 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1802 newcontext.user = tcontext->user;
1803 } else {
1804 /* notice this gets both DEFAULT_SOURCE and unset */
1805 /* Use the process user identity. */
1806 newcontext.user = scontext->user;
1807 }
1808 break;
1809 case AVTAB_MEMBER:
1810 /* Use the related object owner. */
1811 newcontext.user = tcontext->user;
1812 break;
1813 }
1814
1815 /* Set the role to default values. */
1816 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1817 newcontext.role = scontext->role;
1818 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1819 newcontext.role = tcontext->role;
1820 } else {
1821 if ((tclass == policydb->process_class) || sock)
1822 newcontext.role = scontext->role;
1823 else
1824 newcontext.role = OBJECT_R_VAL;
1825 }
1826
1827 /* Set the type to default values. */
1828 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1829 newcontext.type = scontext->type;
1830 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1831 newcontext.type = tcontext->type;
1832 } else {
1833 if ((tclass == policydb->process_class) || sock) {
1834 /* Use the type of process. */
1835 newcontext.type = scontext->type;
1836 } else {
1837 /* Use the type of the related object. */
1838 newcontext.type = tcontext->type;
1839 }
1840 }
1841
1842 /* Look for a type transition/member/change rule. */
1843 avkey.source_type = scontext->type;
1844 avkey.target_type = tcontext->type;
1845 avkey.target_class = tclass;
1846 avkey.specified = specified;
1847 avdatum = avtab_search(&policydb->te_avtab, &avkey);
1848
1849 /* If no permanent rule, also check for enabled conditional rules */
1850 if (!avdatum) {
1851 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1852 for (; node; node = avtab_search_node_next(node, specified)) {
1853 if (node->key.specified & AVTAB_ENABLED) {
1854 avdatum = &node->datum;
1855 break;
1856 }
1857 }
1858 }
1859
1860 if (avdatum) {
1861 /* Use the type from the type transition/member/change rule. */
1862 newcontext.type = avdatum->u.data;
1863 }
1864
1865 /* if we have a objname this is a file trans check so check those rules */
1866 if (objname)
1867 filename_compute_type(policydb, &newcontext, scontext->type,
1868 tcontext->type, tclass, objname);
1869
1870 /* Check for class-specific changes. */
1871 if (specified & AVTAB_TRANSITION) {
1872 /* Look for a role transition rule. */
1873 struct role_trans_datum *rtd;
1874 struct role_trans_key rtk = {
1875 .role = scontext->role,
1876 .type = tcontext->type,
1877 .tclass = tclass,
1878 };
1879
1880 rtd = policydb_roletr_search(policydb, &rtk);
1881 if (rtd)
1882 newcontext.role = rtd->new_role;
1883 }
1884
1885 /* Set the MLS attributes.
1886 This is done last because it may allocate memory. */
1887 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1888 &newcontext, sock);
1889 if (rc)
1890 goto out_unlock;
1891
1892 /* Check the validity of the context. */
1893 if (!policydb_context_isvalid(policydb, &newcontext)) {
1894 rc = compute_sid_handle_invalid_context(state, policy, sentry,
1895 tentry, tclass,
1896 &newcontext);
1897 if (rc)
1898 goto out_unlock;
1899 }
1900 /* Obtain the sid for the context. */
1901 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1902 if (rc == -ESTALE) {
1903 rcu_read_unlock();
1904 context_destroy(&newcontext);
1905 goto retry;
1906 }
1907out_unlock:
1908 rcu_read_unlock();
1909 context_destroy(&newcontext);
1910out:
1911 return rc;
1912}
1913
1914/**
1915 * security_transition_sid - Compute the SID for a new subject/object.
1916 * @state: SELinux state
1917 * @ssid: source security identifier
1918 * @tsid: target security identifier
1919 * @tclass: target security class
1920 * @out_sid: security identifier for new subject/object
1921 *
1922 * Compute a SID to use for labeling a new subject or object in the
1923 * class @tclass based on a SID pair (@ssid, @tsid).
1924 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1925 * if insufficient memory is available, or %0 if the new SID was
1926 * computed successfully.
1927 */
1928int security_transition_sid(struct selinux_state *state,
1929 u32 ssid, u32 tsid, u16 tclass,
1930 const struct qstr *qstr, u32 *out_sid)
1931{
1932 return security_compute_sid(state, ssid, tsid, tclass,
1933 AVTAB_TRANSITION,
1934 qstr ? qstr->name : NULL, out_sid, true);
1935}
1936
1937int security_transition_sid_user(struct selinux_state *state,
1938 u32 ssid, u32 tsid, u16 tclass,
1939 const char *objname, u32 *out_sid)
1940{
1941 return security_compute_sid(state, ssid, tsid, tclass,
1942 AVTAB_TRANSITION,
1943 objname, out_sid, false);
1944}
1945
1946/**
1947 * security_member_sid - Compute the SID for member selection.
1948 * @ssid: source security identifier
1949 * @tsid: target security identifier
1950 * @tclass: target security class
1951 * @out_sid: security identifier for selected member
1952 *
1953 * Compute a SID to use when selecting a member of a polyinstantiated
1954 * object of class @tclass based on a SID pair (@ssid, @tsid).
1955 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1956 * if insufficient memory is available, or %0 if the SID was
1957 * computed successfully.
1958 */
1959int security_member_sid(struct selinux_state *state,
1960 u32 ssid,
1961 u32 tsid,
1962 u16 tclass,
1963 u32 *out_sid)
1964{
1965 return security_compute_sid(state, ssid, tsid, tclass,
1966 AVTAB_MEMBER, NULL,
1967 out_sid, false);
1968}
1969
1970/**
1971 * security_change_sid - Compute the SID for object relabeling.
1972 * @state: SELinux state
1973 * @ssid: source security identifier
1974 * @tsid: target security identifier
1975 * @tclass: target security class
1976 * @out_sid: security identifier for selected member
1977 *
1978 * Compute a SID to use for relabeling an object of class @tclass
1979 * based on a SID pair (@ssid, @tsid).
1980 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1981 * if insufficient memory is available, or %0 if the SID was
1982 * computed successfully.
1983 */
1984int security_change_sid(struct selinux_state *state,
1985 u32 ssid,
1986 u32 tsid,
1987 u16 tclass,
1988 u32 *out_sid)
1989{
1990 return security_compute_sid(state,
1991 ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1992 out_sid, false);
1993}
1994
1995static inline int convert_context_handle_invalid_context(
1996 struct selinux_state *state,
1997 struct policydb *policydb,
1998 struct context *context)
1999{
2000 char *s;
2001 u32 len;
2002
2003 if (enforcing_enabled(state))
2004 return -EINVAL;
2005
2006 if (!context_struct_to_string(policydb, context, &s, &len)) {
2007 pr_warn("SELinux: Context %s would be invalid if enforcing\n",
2008 s);
2009 kfree(s);
2010 }
2011 return 0;
2012}
2013
2014/*
2015 * Convert the values in the security context
2016 * structure `oldc' from the values specified
2017 * in the policy `p->oldp' to the values specified
2018 * in the policy `p->newp', storing the new context
2019 * in `newc'. Verify that the context is valid
2020 * under the new policy.
2021 */
2022static int convert_context(struct context *oldc, struct context *newc, void *p)
2023{
2024 struct convert_context_args *args;
2025 struct ocontext *oc;
2026 struct role_datum *role;
2027 struct type_datum *typdatum;
2028 struct user_datum *usrdatum;
2029 char *s;
2030 u32 len;
2031 int rc;
2032
2033 args = p;
2034
2035 if (oldc->str) {
2036 s = kstrdup(oldc->str, GFP_KERNEL);
2037 if (!s)
2038 return -ENOMEM;
2039
2040 rc = string_to_context_struct(args->newp, NULL, s,
2041 newc, SECSID_NULL);
2042 if (rc == -EINVAL) {
2043 /*
2044 * Retain string representation for later mapping.
2045 *
2046 * IMPORTANT: We need to copy the contents of oldc->str
2047 * back into s again because string_to_context_struct()
2048 * may have garbled it.
2049 */
2050 memcpy(s, oldc->str, oldc->len);
2051 context_init(newc);
2052 newc->str = s;
2053 newc->len = oldc->len;
2054 return 0;
2055 }
2056 kfree(s);
2057 if (rc) {
2058 /* Other error condition, e.g. ENOMEM. */
2059 pr_err("SELinux: Unable to map context %s, rc = %d.\n",
2060 oldc->str, -rc);
2061 return rc;
2062 }
2063 pr_info("SELinux: Context %s became valid (mapped).\n",
2064 oldc->str);
2065 return 0;
2066 }
2067
2068 context_init(newc);
2069
2070 /* Convert the user. */
2071 usrdatum = symtab_search(&args->newp->p_users,
2072 sym_name(args->oldp,
2073 SYM_USERS, oldc->user - 1));
2074 if (!usrdatum)
2075 goto bad;
2076 newc->user = usrdatum->value;
2077
2078 /* Convert the role. */
2079 role = symtab_search(&args->newp->p_roles,
2080 sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2081 if (!role)
2082 goto bad;
2083 newc->role = role->value;
2084
2085 /* Convert the type. */
2086 typdatum = symtab_search(&args->newp->p_types,
2087 sym_name(args->oldp,
2088 SYM_TYPES, oldc->type - 1));
2089 if (!typdatum)
2090 goto bad;
2091 newc->type = typdatum->value;
2092
2093 /* Convert the MLS fields if dealing with MLS policies */
2094 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2095 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2096 if (rc)
2097 goto bad;
2098 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2099 /*
2100 * Switching between non-MLS and MLS policy:
2101 * ensure that the MLS fields of the context for all
2102 * existing entries in the sidtab are filled in with a
2103 * suitable default value, likely taken from one of the
2104 * initial SIDs.
2105 */
2106 oc = args->newp->ocontexts[OCON_ISID];
2107 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2108 oc = oc->next;
2109 if (!oc) {
2110 pr_err("SELinux: unable to look up"
2111 " the initial SIDs list\n");
2112 goto bad;
2113 }
2114 rc = mls_range_set(newc, &oc->context[0].range);
2115 if (rc)
2116 goto bad;
2117 }
2118
2119 /* Check the validity of the new context. */
2120 if (!policydb_context_isvalid(args->newp, newc)) {
2121 rc = convert_context_handle_invalid_context(args->state,
2122 args->oldp,
2123 oldc);
2124 if (rc)
2125 goto bad;
2126 }
2127
2128 return 0;
2129bad:
2130 /* Map old representation to string and save it. */
2131 rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2132 if (rc)
2133 return rc;
2134 context_destroy(newc);
2135 newc->str = s;
2136 newc->len = len;
2137 pr_info("SELinux: Context %s became invalid (unmapped).\n",
2138 newc->str);
2139 return 0;
2140}
2141
2142static void security_load_policycaps(struct selinux_state *state,
2143 struct selinux_policy *policy)
2144{
2145 struct policydb *p;
2146 unsigned int i;
2147 struct ebitmap_node *node;
2148
2149 p = &policy->policydb;
2150
2151 for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2152 WRITE_ONCE(state->policycap[i],
2153 ebitmap_get_bit(&p->policycaps, i));
2154
2155 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2156 pr_info("SELinux: policy capability %s=%d\n",
2157 selinux_policycap_names[i],
2158 ebitmap_get_bit(&p->policycaps, i));
2159
2160 ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2161 if (i >= ARRAY_SIZE(selinux_policycap_names))
2162 pr_info("SELinux: unknown policy capability %u\n",
2163 i);
2164 }
2165}
2166
2167static int security_preserve_bools(struct selinux_policy *oldpolicy,
2168 struct selinux_policy *newpolicy);
2169
2170static void selinux_policy_free(struct selinux_policy *policy)
2171{
2172 if (!policy)
2173 return;
2174
2175 sidtab_destroy(policy->sidtab);
2176 kfree(policy->map.mapping);
2177 policydb_destroy(&policy->policydb);
2178 kfree(policy->sidtab);
2179 kfree(policy);
2180}
2181
2182static void selinux_policy_cond_free(struct selinux_policy *policy)
2183{
2184 cond_policydb_destroy_dup(&policy->policydb);
2185 kfree(policy);
2186}
2187
2188void selinux_policy_cancel(struct selinux_state *state,
2189 struct selinux_load_state *load_state)
2190{
2191 struct selinux_policy *oldpolicy;
2192
2193 oldpolicy = rcu_dereference_protected(state->policy,
2194 lockdep_is_held(&state->policy_mutex));
2195
2196 sidtab_cancel_convert(oldpolicy->sidtab);
2197 selinux_policy_free(load_state->policy);
2198 kfree(load_state->convert_data);
2199}
2200
2201static void selinux_notify_policy_change(struct selinux_state *state,
2202 u32 seqno)
2203{
2204 /* Flush external caches and notify userspace of policy load */
2205 avc_ss_reset(state->avc, seqno);
2206 selnl_notify_policyload(seqno);
2207 selinux_status_update_policyload(state, seqno);
2208 selinux_netlbl_cache_invalidate();
2209 selinux_xfrm_notify_policyload();
2210 selinux_ima_measure_state_locked(state);
2211}
2212
2213void selinux_policy_commit(struct selinux_state *state,
2214 struct selinux_load_state *load_state)
2215{
2216 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
2217 unsigned long flags;
2218 u32 seqno;
2219
2220 oldpolicy = rcu_dereference_protected(state->policy,
2221 lockdep_is_held(&state->policy_mutex));
2222
2223 /* If switching between different policy types, log MLS status */
2224 if (oldpolicy) {
2225 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
2226 pr_info("SELinux: Disabling MLS support...\n");
2227 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
2228 pr_info("SELinux: Enabling MLS support...\n");
2229 }
2230
2231 /* Set latest granting seqno for new policy. */
2232 if (oldpolicy)
2233 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
2234 else
2235 newpolicy->latest_granting = 1;
2236 seqno = newpolicy->latest_granting;
2237
2238 /* Install the new policy. */
2239 if (oldpolicy) {
2240 sidtab_freeze_begin(oldpolicy->sidtab, &flags);
2241 rcu_assign_pointer(state->policy, newpolicy);
2242 sidtab_freeze_end(oldpolicy->sidtab, &flags);
2243 } else {
2244 rcu_assign_pointer(state->policy, newpolicy);
2245 }
2246
2247 /* Load the policycaps from the new policy */
2248 security_load_policycaps(state, newpolicy);
2249
2250 if (!selinux_initialized(state)) {
2251 /*
2252 * After first policy load, the security server is
2253 * marked as initialized and ready to handle requests and
2254 * any objects created prior to policy load are then labeled.
2255 */
2256 selinux_mark_initialized(state);
2257 selinux_complete_init();
2258 }
2259
2260 /* Free the old policy */
2261 synchronize_rcu();
2262 selinux_policy_free(oldpolicy);
2263 kfree(load_state->convert_data);
2264
2265 /* Notify others of the policy change */
2266 selinux_notify_policy_change(state, seqno);
2267}
2268
2269/**
2270 * security_load_policy - Load a security policy configuration.
2271 * @state: SELinux state
2272 * @data: binary policy data
2273 * @len: length of data in bytes
2274 *
2275 * Load a new set of security policy configuration data,
2276 * validate it and convert the SID table as necessary.
2277 * This function will flush the access vector cache after
2278 * loading the new policy.
2279 */
2280int security_load_policy(struct selinux_state *state, void *data, size_t len,
2281 struct selinux_load_state *load_state)
2282{
2283 struct selinux_policy *newpolicy, *oldpolicy;
2284 struct selinux_policy_convert_data *convert_data;
2285 int rc = 0;
2286 struct policy_file file = { data, len }, *fp = &file;
2287
2288 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2289 if (!newpolicy)
2290 return -ENOMEM;
2291
2292 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2293 if (!newpolicy->sidtab) {
2294 rc = -ENOMEM;
2295 goto err_policy;
2296 }
2297
2298 rc = policydb_read(&newpolicy->policydb, fp);
2299 if (rc)
2300 goto err_sidtab;
2301
2302 newpolicy->policydb.len = len;
2303 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2304 &newpolicy->map);
2305 if (rc)
2306 goto err_policydb;
2307
2308 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2309 if (rc) {
2310 pr_err("SELinux: unable to load the initial SIDs\n");
2311 goto err_mapping;
2312 }
2313
2314 if (!selinux_initialized(state)) {
2315 /* First policy load, so no need to preserve state from old policy */
2316 load_state->policy = newpolicy;
2317 load_state->convert_data = NULL;
2318 return 0;
2319 }
2320
2321 oldpolicy = rcu_dereference_protected(state->policy,
2322 lockdep_is_held(&state->policy_mutex));
2323
2324 /* Preserve active boolean values from the old policy */
2325 rc = security_preserve_bools(oldpolicy, newpolicy);
2326 if (rc) {
2327 pr_err("SELinux: unable to preserve booleans\n");
2328 goto err_free_isids;
2329 }
2330
2331 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2332 if (!convert_data) {
2333 rc = -ENOMEM;
2334 goto err_free_isids;
2335 }
2336
2337 /*
2338 * Convert the internal representations of contexts
2339 * in the new SID table.
2340 */
2341 convert_data->args.state = state;
2342 convert_data->args.oldp = &oldpolicy->policydb;
2343 convert_data->args.newp = &newpolicy->policydb;
2344
2345 convert_data->sidtab_params.func = convert_context;
2346 convert_data->sidtab_params.args = &convert_data->args;
2347 convert_data->sidtab_params.target = newpolicy->sidtab;
2348
2349 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2350 if (rc) {
2351 pr_err("SELinux: unable to convert the internal"
2352 " representation of contexts in the new SID"
2353 " table\n");
2354 goto err_free_convert_data;
2355 }
2356
2357 load_state->policy = newpolicy;
2358 load_state->convert_data = convert_data;
2359 return 0;
2360
2361err_free_convert_data:
2362 kfree(convert_data);
2363err_free_isids:
2364 sidtab_destroy(newpolicy->sidtab);
2365err_mapping:
2366 kfree(newpolicy->map.mapping);
2367err_policydb:
2368 policydb_destroy(&newpolicy->policydb);
2369err_sidtab:
2370 kfree(newpolicy->sidtab);
2371err_policy:
2372 kfree(newpolicy);
2373
2374 return rc;
2375}
2376
2377/**
2378 * security_port_sid - Obtain the SID for a port.
2379 * @state: SELinux state
2380 * @protocol: protocol number
2381 * @port: port number
2382 * @out_sid: security identifier
2383 */
2384int security_port_sid(struct selinux_state *state,
2385 u8 protocol, u16 port, u32 *out_sid)
2386{
2387 struct selinux_policy *policy;
2388 struct policydb *policydb;
2389 struct sidtab *sidtab;
2390 struct ocontext *c;
2391 int rc;
2392
2393 if (!selinux_initialized(state)) {
2394 *out_sid = SECINITSID_PORT;
2395 return 0;
2396 }
2397
2398retry:
2399 rc = 0;
2400 rcu_read_lock();
2401 policy = rcu_dereference(state->policy);
2402 policydb = &policy->policydb;
2403 sidtab = policy->sidtab;
2404
2405 c = policydb->ocontexts[OCON_PORT];
2406 while (c) {
2407 if (c->u.port.protocol == protocol &&
2408 c->u.port.low_port <= port &&
2409 c->u.port.high_port >= port)
2410 break;
2411 c = c->next;
2412 }
2413
2414 if (c) {
2415 if (!c->sid[0]) {
2416 rc = sidtab_context_to_sid(sidtab, &c->context[0],
2417 &c->sid[0]);
2418 if (rc == -ESTALE) {
2419 rcu_read_unlock();
2420 goto retry;
2421 }
2422 if (rc)
2423 goto out;
2424 }
2425 *out_sid = c->sid[0];
2426 } else {
2427 *out_sid = SECINITSID_PORT;
2428 }
2429
2430out:
2431 rcu_read_unlock();
2432 return rc;
2433}
2434
2435/**
2436 * security_ib_pkey_sid - Obtain the SID for a pkey.
2437 * @state: SELinux state
2438 * @subnet_prefix: Subnet Prefix
2439 * @pkey_num: pkey number
2440 * @out_sid: security identifier
2441 */
2442int security_ib_pkey_sid(struct selinux_state *state,
2443 u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2444{
2445 struct selinux_policy *policy;
2446 struct policydb *policydb;
2447 struct sidtab *sidtab;
2448 struct ocontext *c;
2449 int rc;
2450
2451 if (!selinux_initialized(state)) {
2452 *out_sid = SECINITSID_UNLABELED;
2453 return 0;
2454 }
2455
2456retry:
2457 rc = 0;
2458 rcu_read_lock();
2459 policy = rcu_dereference(state->policy);
2460 policydb = &policy->policydb;
2461 sidtab = policy->sidtab;
2462
2463 c = policydb->ocontexts[OCON_IBPKEY];
2464 while (c) {
2465 if (c->u.ibpkey.low_pkey <= pkey_num &&
2466 c->u.ibpkey.high_pkey >= pkey_num &&
2467 c->u.ibpkey.subnet_prefix == subnet_prefix)
2468 break;
2469
2470 c = c->next;
2471 }
2472
2473 if (c) {
2474 if (!c->sid[0]) {
2475 rc = sidtab_context_to_sid(sidtab,
2476 &c->context[0],
2477 &c->sid[0]);
2478 if (rc == -ESTALE) {
2479 rcu_read_unlock();
2480 goto retry;
2481 }
2482 if (rc)
2483 goto out;
2484 }
2485 *out_sid = c->sid[0];
2486 } else
2487 *out_sid = SECINITSID_UNLABELED;
2488
2489out:
2490 rcu_read_unlock();
2491 return rc;
2492}
2493
2494/**
2495 * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2496 * @state: SELinux state
2497 * @dev_name: device name
2498 * @port: port number
2499 * @out_sid: security identifier
2500 */
2501int security_ib_endport_sid(struct selinux_state *state,
2502 const char *dev_name, u8 port_num, u32 *out_sid)
2503{
2504 struct selinux_policy *policy;
2505 struct policydb *policydb;
2506 struct sidtab *sidtab;
2507 struct ocontext *c;
2508 int rc;
2509
2510 if (!selinux_initialized(state)) {
2511 *out_sid = SECINITSID_UNLABELED;
2512 return 0;
2513 }
2514
2515retry:
2516 rc = 0;
2517 rcu_read_lock();
2518 policy = rcu_dereference(state->policy);
2519 policydb = &policy->policydb;
2520 sidtab = policy->sidtab;
2521
2522 c = policydb->ocontexts[OCON_IBENDPORT];
2523 while (c) {
2524 if (c->u.ibendport.port == port_num &&
2525 !strncmp(c->u.ibendport.dev_name,
2526 dev_name,
2527 IB_DEVICE_NAME_MAX))
2528 break;
2529
2530 c = c->next;
2531 }
2532
2533 if (c) {
2534 if (!c->sid[0]) {
2535 rc = sidtab_context_to_sid(sidtab, &c->context[0],
2536 &c->sid[0]);
2537 if (rc == -ESTALE) {
2538 rcu_read_unlock();
2539 goto retry;
2540 }
2541 if (rc)
2542 goto out;
2543 }
2544 *out_sid = c->sid[0];
2545 } else
2546 *out_sid = SECINITSID_UNLABELED;
2547
2548out:
2549 rcu_read_unlock();
2550 return rc;
2551}
2552
2553/**
2554 * security_netif_sid - Obtain the SID for a network interface.
2555 * @state: SELinux state
2556 * @name: interface name
2557 * @if_sid: interface SID
2558 */
2559int security_netif_sid(struct selinux_state *state,
2560 char *name, u32 *if_sid)
2561{
2562 struct selinux_policy *policy;
2563 struct policydb *policydb;
2564 struct sidtab *sidtab;
2565 int rc;
2566 struct ocontext *c;
2567
2568 if (!selinux_initialized(state)) {
2569 *if_sid = SECINITSID_NETIF;
2570 return 0;
2571 }
2572
2573retry:
2574 rc = 0;
2575 rcu_read_lock();
2576 policy = rcu_dereference(state->policy);
2577 policydb = &policy->policydb;
2578 sidtab = policy->sidtab;
2579
2580 c = policydb->ocontexts[OCON_NETIF];
2581 while (c) {
2582 if (strcmp(name, c->u.name) == 0)
2583 break;
2584 c = c->next;
2585 }
2586
2587 if (c) {
2588 if (!c->sid[0] || !c->sid[1]) {
2589 rc = sidtab_context_to_sid(sidtab, &c->context[0],
2590 &c->sid[0]);
2591 if (rc == -ESTALE) {
2592 rcu_read_unlock();
2593 goto retry;
2594 }
2595 if (rc)
2596 goto out;
2597 rc = sidtab_context_to_sid(sidtab, &c->context[1],
2598 &c->sid[1]);
2599 if (rc == -ESTALE) {
2600 rcu_read_unlock();
2601 goto retry;
2602 }
2603 if (rc)
2604 goto out;
2605 }
2606 *if_sid = c->sid[0];
2607 } else
2608 *if_sid = SECINITSID_NETIF;
2609
2610out:
2611 rcu_read_unlock();
2612 return rc;
2613}
2614
2615static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2616{
2617 int i, fail = 0;
2618
2619 for (i = 0; i < 4; i++)
2620 if (addr[i] != (input[i] & mask[i])) {
2621 fail = 1;
2622 break;
2623 }
2624
2625 return !fail;
2626}
2627
2628/**
2629 * security_node_sid - Obtain the SID for a node (host).
2630 * @state: SELinux state
2631 * @domain: communication domain aka address family
2632 * @addrp: address
2633 * @addrlen: address length in bytes
2634 * @out_sid: security identifier
2635 */
2636int security_node_sid(struct selinux_state *state,
2637 u16 domain,
2638 void *addrp,
2639 u32 addrlen,
2640 u32 *out_sid)
2641{
2642 struct selinux_policy *policy;
2643 struct policydb *policydb;
2644 struct sidtab *sidtab;
2645 int rc;
2646 struct ocontext *c;
2647
2648 if (!selinux_initialized(state)) {
2649 *out_sid = SECINITSID_NODE;
2650 return 0;
2651 }
2652
2653retry:
2654 rcu_read_lock();
2655 policy = rcu_dereference(state->policy);
2656 policydb = &policy->policydb;
2657 sidtab = policy->sidtab;
2658
2659 switch (domain) {
2660 case AF_INET: {
2661 u32 addr;
2662
2663 rc = -EINVAL;
2664 if (addrlen != sizeof(u32))
2665 goto out;
2666
2667 addr = *((u32 *)addrp);
2668
2669 c = policydb->ocontexts[OCON_NODE];
2670 while (c) {
2671 if (c->u.node.addr == (addr & c->u.node.mask))
2672 break;
2673 c = c->next;
2674 }
2675 break;
2676 }
2677
2678 case AF_INET6:
2679 rc = -EINVAL;
2680 if (addrlen != sizeof(u64) * 2)
2681 goto out;
2682 c = policydb->ocontexts[OCON_NODE6];
2683 while (c) {
2684 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2685 c->u.node6.mask))
2686 break;
2687 c = c->next;
2688 }
2689 break;
2690
2691 default:
2692 rc = 0;
2693 *out_sid = SECINITSID_NODE;
2694 goto out;
2695 }
2696
2697 if (c) {
2698 if (!c->sid[0]) {
2699 rc = sidtab_context_to_sid(sidtab,
2700 &c->context[0],
2701 &c->sid[0]);
2702 if (rc == -ESTALE) {
2703 rcu_read_unlock();
2704 goto retry;
2705 }
2706 if (rc)
2707 goto out;
2708 }
2709 *out_sid = c->sid[0];
2710 } else {
2711 *out_sid = SECINITSID_NODE;
2712 }
2713
2714 rc = 0;
2715out:
2716 rcu_read_unlock();
2717 return rc;
2718}
2719
2720#define SIDS_NEL 25
2721
2722/**
2723 * security_get_user_sids - Obtain reachable SIDs for a user.
2724 * @state: SELinux state
2725 * @fromsid: starting SID
2726 * @username: username
2727 * @sids: array of reachable SIDs for user
2728 * @nel: number of elements in @sids
2729 *
2730 * Generate the set of SIDs for legal security contexts
2731 * for a given user that can be reached by @fromsid.
2732 * Set *@sids to point to a dynamically allocated
2733 * array containing the set of SIDs. Set *@nel to the
2734 * number of elements in the array.
2735 */
2736
2737int security_get_user_sids(struct selinux_state *state,
2738 u32 fromsid,
2739 char *username,
2740 u32 **sids,
2741 u32 *nel)
2742{
2743 struct selinux_policy *policy;
2744 struct policydb *policydb;
2745 struct sidtab *sidtab;
2746 struct context *fromcon, usercon;
2747 u32 *mysids = NULL, *mysids2, sid;
2748 u32 i, j, mynel, maxnel = SIDS_NEL;
2749 struct user_datum *user;
2750 struct role_datum *role;
2751 struct ebitmap_node *rnode, *tnode;
2752 int rc;
2753
2754 *sids = NULL;
2755 *nel = 0;
2756
2757 if (!selinux_initialized(state))
2758 return 0;
2759
2760 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2761 if (!mysids)
2762 return -ENOMEM;
2763
2764retry:
2765 mynel = 0;
2766 rcu_read_lock();
2767 policy = rcu_dereference(state->policy);
2768 policydb = &policy->policydb;
2769 sidtab = policy->sidtab;
2770
2771 context_init(&usercon);
2772
2773 rc = -EINVAL;
2774 fromcon = sidtab_search(sidtab, fromsid);
2775 if (!fromcon)
2776 goto out_unlock;
2777
2778 rc = -EINVAL;
2779 user = symtab_search(&policydb->p_users, username);
2780 if (!user)
2781 goto out_unlock;
2782
2783 usercon.user = user->value;
2784
2785 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2786 role = policydb->role_val_to_struct[i];
2787 usercon.role = i + 1;
2788 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2789 usercon.type = j + 1;
2790
2791 if (mls_setup_user_range(policydb, fromcon, user,
2792 &usercon))
2793 continue;
2794
2795 rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2796 if (rc == -ESTALE) {
2797 rcu_read_unlock();
2798 goto retry;
2799 }
2800 if (rc)
2801 goto out_unlock;
2802 if (mynel < maxnel) {
2803 mysids[mynel++] = sid;
2804 } else {
2805 rc = -ENOMEM;
2806 maxnel += SIDS_NEL;
2807 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2808 if (!mysids2)
2809 goto out_unlock;
2810 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2811 kfree(mysids);
2812 mysids = mysids2;
2813 mysids[mynel++] = sid;
2814 }
2815 }
2816 }
2817 rc = 0;
2818out_unlock:
2819 rcu_read_unlock();
2820 if (rc || !mynel) {
2821 kfree(mysids);
2822 return rc;
2823 }
2824
2825 rc = -ENOMEM;
2826 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2827 if (!mysids2) {
2828 kfree(mysids);
2829 return rc;
2830 }
2831 for (i = 0, j = 0; i < mynel; i++) {
2832 struct av_decision dummy_avd;
2833 rc = avc_has_perm_noaudit(state,
2834 fromsid, mysids[i],
2835 SECCLASS_PROCESS, /* kernel value */
2836 PROCESS__TRANSITION, AVC_STRICT,
2837 &dummy_avd);
2838 if (!rc)
2839 mysids2[j++] = mysids[i];
2840 cond_resched();
2841 }
2842 kfree(mysids);
2843 *sids = mysids2;
2844 *nel = j;
2845 return 0;
2846}
2847
2848/**
2849 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2850 * @fstype: filesystem type
2851 * @path: path from root of mount
2852 * @sclass: file security class
2853 * @sid: SID for path
2854 *
2855 * Obtain a SID to use for a file in a filesystem that
2856 * cannot support xattr or use a fixed labeling behavior like
2857 * transition SIDs or task SIDs.
2858 *
2859 * WARNING: This function may return -ESTALE, indicating that the caller
2860 * must retry the operation after re-acquiring the policy pointer!
2861 */
2862static inline int __security_genfs_sid(struct selinux_policy *policy,
2863 const char *fstype,
2864 char *path,
2865 u16 orig_sclass,
2866 u32 *sid)
2867{
2868 struct policydb *policydb = &policy->policydb;
2869 struct sidtab *sidtab = policy->sidtab;
2870 int len;
2871 u16 sclass;
2872 struct genfs *genfs;
2873 struct ocontext *c;
2874 int rc, cmp = 0;
2875
2876 while (path[0] == '/' && path[1] == '/')
2877 path++;
2878
2879 sclass = unmap_class(&policy->map, orig_sclass);
2880 *sid = SECINITSID_UNLABELED;
2881
2882 for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2883 cmp = strcmp(fstype, genfs->fstype);
2884 if (cmp <= 0)
2885 break;
2886 }
2887
2888 rc = -ENOENT;
2889 if (!genfs || cmp)
2890 goto out;
2891
2892 for (c = genfs->head; c; c = c->next) {
2893 len = strlen(c->u.name);
2894 if ((!c->v.sclass || sclass == c->v.sclass) &&
2895 (strncmp(c->u.name, path, len) == 0))
2896 break;
2897 }
2898
2899 rc = -ENOENT;
2900 if (!c)
2901 goto out;
2902
2903 if (!c->sid[0]) {
2904 rc = sidtab_context_to_sid(sidtab, &c->context[0], &c->sid[0]);
2905 if (rc)
2906 goto out;
2907 }
2908
2909 *sid = c->sid[0];
2910 rc = 0;
2911out:
2912 return rc;
2913}
2914
2915/**
2916 * security_genfs_sid - Obtain a SID for a file in a filesystem
2917 * @state: SELinux state
2918 * @fstype: filesystem type
2919 * @path: path from root of mount
2920 * @sclass: file security class
2921 * @sid: SID for path
2922 *
2923 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2924 * it afterward.
2925 */
2926int security_genfs_sid(struct selinux_state *state,
2927 const char *fstype,
2928 char *path,
2929 u16 orig_sclass,
2930 u32 *sid)
2931{
2932 struct selinux_policy *policy;
2933 int retval;
2934
2935 if (!selinux_initialized(state)) {
2936 *sid = SECINITSID_UNLABELED;
2937 return 0;
2938 }
2939
2940 do {
2941 rcu_read_lock();
2942 policy = rcu_dereference(state->policy);
2943 retval = __security_genfs_sid(policy, fstype, path,
2944 orig_sclass, sid);
2945 rcu_read_unlock();
2946 } while (retval == -ESTALE);
2947 return retval;
2948}
2949
2950int selinux_policy_genfs_sid(struct selinux_policy *policy,
2951 const char *fstype,
2952 char *path,
2953 u16 orig_sclass,
2954 u32 *sid)
2955{
2956 /* no lock required, policy is not yet accessible by other threads */
2957 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2958}
2959
2960/**
2961 * security_fs_use - Determine how to handle labeling for a filesystem.
2962 * @state: SELinux state
2963 * @sb: superblock in question
2964 */
2965int security_fs_use(struct selinux_state *state, struct super_block *sb)
2966{
2967 struct selinux_policy *policy;
2968 struct policydb *policydb;
2969 struct sidtab *sidtab;
2970 int rc;
2971 struct ocontext *c;
2972 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2973 const char *fstype = sb->s_type->name;
2974
2975 if (!selinux_initialized(state)) {
2976 sbsec->behavior = SECURITY_FS_USE_NONE;
2977 sbsec->sid = SECINITSID_UNLABELED;
2978 return 0;
2979 }
2980
2981retry:
2982 rc = 0;
2983 rcu_read_lock();
2984 policy = rcu_dereference(state->policy);
2985 policydb = &policy->policydb;
2986 sidtab = policy->sidtab;
2987
2988 c = policydb->ocontexts[OCON_FSUSE];
2989 while (c) {
2990 if (strcmp(fstype, c->u.name) == 0)
2991 break;
2992 c = c->next;
2993 }
2994
2995 if (c) {
2996 sbsec->behavior = c->v.behavior;
2997 if (!c->sid[0]) {
2998 rc = sidtab_context_to_sid(sidtab, &c->context[0],
2999 &c->sid[0]);
3000 if (rc == -ESTALE) {
3001 rcu_read_unlock();
3002 goto retry;
3003 }
3004 if (rc)
3005 goto out;
3006 }
3007 sbsec->sid = c->sid[0];
3008 } else {
3009 rc = __security_genfs_sid(policy, fstype, "/",
3010 SECCLASS_DIR, &sbsec->sid);
3011 if (rc == -ESTALE) {
3012 rcu_read_unlock();
3013 goto retry;
3014 }
3015 if (rc) {
3016 sbsec->behavior = SECURITY_FS_USE_NONE;
3017 rc = 0;
3018 } else {
3019 sbsec->behavior = SECURITY_FS_USE_GENFS;
3020 }
3021 }
3022
3023out:
3024 rcu_read_unlock();
3025 return rc;
3026}
3027
3028int security_get_bools(struct selinux_policy *policy,
3029 u32 *len, char ***names, int **values)
3030{
3031 struct policydb *policydb;
3032 u32 i;
3033 int rc;
3034
3035 policydb = &policy->policydb;
3036
3037 *names = NULL;
3038 *values = NULL;
3039
3040 rc = 0;
3041 *len = policydb->p_bools.nprim;
3042 if (!*len)
3043 goto out;
3044
3045 rc = -ENOMEM;
3046 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
3047 if (!*names)
3048 goto err;
3049
3050 rc = -ENOMEM;
3051 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
3052 if (!*values)
3053 goto err;
3054
3055 for (i = 0; i < *len; i++) {
3056 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3057
3058 rc = -ENOMEM;
3059 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3060 GFP_ATOMIC);
3061 if (!(*names)[i])
3062 goto err;
3063 }
3064 rc = 0;
3065out:
3066 return rc;
3067err:
3068 if (*names) {
3069 for (i = 0; i < *len; i++)
3070 kfree((*names)[i]);
3071 kfree(*names);
3072 }
3073 kfree(*values);
3074 *len = 0;
3075 *names = NULL;
3076 *values = NULL;
3077 goto out;
3078}
3079
3080
3081int security_set_bools(struct selinux_state *state, u32 len, int *values)
3082{
3083 struct selinux_policy *newpolicy, *oldpolicy;
3084 int rc;
3085 u32 i, seqno = 0;
3086
3087 if (!selinux_initialized(state))
3088 return -EINVAL;
3089
3090 oldpolicy = rcu_dereference_protected(state->policy,
3091 lockdep_is_held(&state->policy_mutex));
3092
3093 /* Consistency check on number of booleans, should never fail */
3094 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3095 return -EINVAL;
3096
3097 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3098 if (!newpolicy)
3099 return -ENOMEM;
3100
3101 /*
3102 * Deep copy only the parts of the policydb that might be
3103 * modified as a result of changing booleans.
3104 */
3105 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3106 if (rc) {
3107 kfree(newpolicy);
3108 return -ENOMEM;
3109 }
3110
3111 /* Update the boolean states in the copy */
3112 for (i = 0; i < len; i++) {
3113 int new_state = !!values[i];
3114 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3115
3116 if (new_state != old_state) {
3117 audit_log(audit_context(), GFP_ATOMIC,
3118 AUDIT_MAC_CONFIG_CHANGE,
3119 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3120 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3121 new_state,
3122 old_state,
3123 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3124 audit_get_sessionid(current));
3125 newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3126 }
3127 }
3128
3129 /* Re-evaluate the conditional rules in the copy */
3130 evaluate_cond_nodes(&newpolicy->policydb);
3131
3132 /* Set latest granting seqno for new policy */
3133 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3134 seqno = newpolicy->latest_granting;
3135
3136 /* Install the new policy */
3137 rcu_assign_pointer(state->policy, newpolicy);
3138
3139 /*
3140 * Free the conditional portions of the old policydb
3141 * that were copied for the new policy, and the oldpolicy
3142 * structure itself but not what it references.
3143 */
3144 synchronize_rcu();
3145 selinux_policy_cond_free(oldpolicy);
3146
3147 /* Notify others of the policy change */
3148 selinux_notify_policy_change(state, seqno);
3149 return 0;
3150}
3151
3152int security_get_bool_value(struct selinux_state *state,
3153 u32 index)
3154{
3155 struct selinux_policy *policy;
3156 struct policydb *policydb;
3157 int rc;
3158 u32 len;
3159
3160 if (!selinux_initialized(state))
3161 return 0;
3162
3163 rcu_read_lock();
3164 policy = rcu_dereference(state->policy);
3165 policydb = &policy->policydb;
3166
3167 rc = -EFAULT;
3168 len = policydb->p_bools.nprim;
3169 if (index >= len)
3170 goto out;
3171
3172 rc = policydb->bool_val_to_struct[index]->state;
3173out:
3174 rcu_read_unlock();
3175 return rc;
3176}
3177
3178static int security_preserve_bools(struct selinux_policy *oldpolicy,
3179 struct selinux_policy *newpolicy)
3180{
3181 int rc, *bvalues = NULL;
3182 char **bnames = NULL;
3183 struct cond_bool_datum *booldatum;
3184 u32 i, nbools = 0;
3185
3186 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3187 if (rc)
3188 goto out;
3189 for (i = 0; i < nbools; i++) {
3190 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3191 bnames[i]);
3192 if (booldatum)
3193 booldatum->state = bvalues[i];
3194 }
3195 evaluate_cond_nodes(&newpolicy->policydb);
3196
3197out:
3198 if (bnames) {
3199 for (i = 0; i < nbools; i++)
3200 kfree(bnames[i]);
3201 }
3202 kfree(bnames);
3203 kfree(bvalues);
3204 return rc;
3205}
3206
3207/*
3208 * security_sid_mls_copy() - computes a new sid based on the given
3209 * sid and the mls portion of mls_sid.
3210 */
3211int security_sid_mls_copy(struct selinux_state *state,
3212 u32 sid, u32 mls_sid, u32 *new_sid)
3213{
3214 struct selinux_policy *policy;
3215 struct policydb *policydb;
3216 struct sidtab *sidtab;
3217 struct context *context1;
3218 struct context *context2;
3219 struct context newcon;
3220 char *s;
3221 u32 len;
3222 int rc;
3223
3224 if (!selinux_initialized(state)) {
3225 *new_sid = sid;
3226 return 0;
3227 }
3228
3229retry:
3230 rc = 0;
3231 context_init(&newcon);
3232
3233 rcu_read_lock();
3234 policy = rcu_dereference(state->policy);
3235 policydb = &policy->policydb;
3236 sidtab = policy->sidtab;
3237
3238 if (!policydb->mls_enabled) {
3239 *new_sid = sid;
3240 goto out_unlock;
3241 }
3242
3243 rc = -EINVAL;
3244 context1 = sidtab_search(sidtab, sid);
3245 if (!context1) {
3246 pr_err("SELinux: %s: unrecognized SID %d\n",
3247 __func__, sid);
3248 goto out_unlock;
3249 }
3250
3251 rc = -EINVAL;
3252 context2 = sidtab_search(sidtab, mls_sid);
3253 if (!context2) {
3254 pr_err("SELinux: %s: unrecognized SID %d\n",
3255 __func__, mls_sid);
3256 goto out_unlock;
3257 }
3258
3259 newcon.user = context1->user;
3260 newcon.role = context1->role;
3261 newcon.type = context1->type;
3262 rc = mls_context_cpy(&newcon, context2);
3263 if (rc)
3264 goto out_unlock;
3265
3266 /* Check the validity of the new context. */
3267 if (!policydb_context_isvalid(policydb, &newcon)) {
3268 rc = convert_context_handle_invalid_context(state, policydb,
3269 &newcon);
3270 if (rc) {
3271 if (!context_struct_to_string(policydb, &newcon, &s,
3272 &len)) {
3273 struct audit_buffer *ab;
3274
3275 ab = audit_log_start(audit_context(),
3276 GFP_ATOMIC,
3277 AUDIT_SELINUX_ERR);
3278 audit_log_format(ab,
3279 "op=security_sid_mls_copy invalid_context=");
3280 /* don't record NUL with untrusted strings */
3281 audit_log_n_untrustedstring(ab, s, len - 1);
3282 audit_log_end(ab);
3283 kfree(s);
3284 }
3285 goto out_unlock;
3286 }
3287 }
3288 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3289 if (rc == -ESTALE) {
3290 rcu_read_unlock();
3291 context_destroy(&newcon);
3292 goto retry;
3293 }
3294out_unlock:
3295 rcu_read_unlock();
3296 context_destroy(&newcon);
3297 return rc;
3298}
3299
3300/**
3301 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3302 * @state: SELinux state
3303 * @nlbl_sid: NetLabel SID
3304 * @nlbl_type: NetLabel labeling protocol type
3305 * @xfrm_sid: XFRM SID
3306 *
3307 * Description:
3308 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3309 * resolved into a single SID it is returned via @peer_sid and the function
3310 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
3311 * returns a negative value. A table summarizing the behavior is below:
3312 *
3313 * | function return | @sid
3314 * ------------------------------+-----------------+-----------------
3315 * no peer labels | 0 | SECSID_NULL
3316 * single peer label | 0 | <peer_label>
3317 * multiple, consistent labels | 0 | <peer_label>
3318 * multiple, inconsistent labels | -<errno> | SECSID_NULL
3319 *
3320 */
3321int security_net_peersid_resolve(struct selinux_state *state,
3322 u32 nlbl_sid, u32 nlbl_type,
3323 u32 xfrm_sid,
3324 u32 *peer_sid)
3325{
3326 struct selinux_policy *policy;
3327 struct policydb *policydb;
3328 struct sidtab *sidtab;
3329 int rc;
3330 struct context *nlbl_ctx;
3331 struct context *xfrm_ctx;
3332
3333 *peer_sid = SECSID_NULL;
3334
3335 /* handle the common (which also happens to be the set of easy) cases
3336 * right away, these two if statements catch everything involving a
3337 * single or absent peer SID/label */
3338 if (xfrm_sid == SECSID_NULL) {
3339 *peer_sid = nlbl_sid;
3340 return 0;
3341 }
3342 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3343 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3344 * is present */
3345 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3346 *peer_sid = xfrm_sid;
3347 return 0;
3348 }
3349
3350 if (!selinux_initialized(state))
3351 return 0;
3352
3353 rcu_read_lock();
3354 policy = rcu_dereference(state->policy);
3355 policydb = &policy->policydb;
3356 sidtab = policy->sidtab;
3357
3358 /*
3359 * We don't need to check initialized here since the only way both
3360 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3361 * security server was initialized and state->initialized was true.
3362 */
3363 if (!policydb->mls_enabled) {
3364 rc = 0;
3365 goto out;
3366 }
3367
3368 rc = -EINVAL;
3369 nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3370 if (!nlbl_ctx) {
3371 pr_err("SELinux: %s: unrecognized SID %d\n",
3372 __func__, nlbl_sid);
3373 goto out;
3374 }
3375 rc = -EINVAL;
3376 xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3377 if (!xfrm_ctx) {
3378 pr_err("SELinux: %s: unrecognized SID %d\n",
3379 __func__, xfrm_sid);
3380 goto out;
3381 }
3382 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3383 if (rc)
3384 goto out;
3385
3386 /* at present NetLabel SIDs/labels really only carry MLS
3387 * information so if the MLS portion of the NetLabel SID
3388 * matches the MLS portion of the labeled XFRM SID/label
3389 * then pass along the XFRM SID as it is the most
3390 * expressive */
3391 *peer_sid = xfrm_sid;
3392out:
3393 rcu_read_unlock();
3394 return rc;
3395}
3396
3397static int get_classes_callback(void *k, void *d, void *args)
3398{
3399 struct class_datum *datum = d;
3400 char *name = k, **classes = args;
3401 int value = datum->value - 1;
3402
3403 classes[value] = kstrdup(name, GFP_ATOMIC);
3404 if (!classes[value])
3405 return -ENOMEM;
3406
3407 return 0;
3408}
3409
3410int security_get_classes(struct selinux_policy *policy,
3411 char ***classes, int *nclasses)
3412{
3413 struct policydb *policydb;
3414 int rc;
3415
3416 policydb = &policy->policydb;
3417
3418 rc = -ENOMEM;
3419 *nclasses = policydb->p_classes.nprim;
3420 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3421 if (!*classes)
3422 goto out;
3423
3424 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3425 *classes);
3426 if (rc) {
3427 int i;
3428 for (i = 0; i < *nclasses; i++)
3429 kfree((*classes)[i]);
3430 kfree(*classes);
3431 }
3432
3433out:
3434 return rc;
3435}
3436
3437static int get_permissions_callback(void *k, void *d, void *args)
3438{
3439 struct perm_datum *datum = d;
3440 char *name = k, **perms = args;
3441 int value = datum->value - 1;
3442
3443 perms[value] = kstrdup(name, GFP_ATOMIC);
3444 if (!perms[value])
3445 return -ENOMEM;
3446
3447 return 0;
3448}
3449
3450int security_get_permissions(struct selinux_policy *policy,
3451 char *class, char ***perms, int *nperms)
3452{
3453 struct policydb *policydb;
3454 int rc, i;
3455 struct class_datum *match;
3456
3457 policydb = &policy->policydb;
3458
3459 rc = -EINVAL;
3460 match = symtab_search(&policydb->p_classes, class);
3461 if (!match) {
3462 pr_err("SELinux: %s: unrecognized class %s\n",
3463 __func__, class);
3464 goto out;
3465 }
3466
3467 rc = -ENOMEM;
3468 *nperms = match->permissions.nprim;
3469 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3470 if (!*perms)
3471 goto out;
3472
3473 if (match->comdatum) {
3474 rc = hashtab_map(&match->comdatum->permissions.table,
3475 get_permissions_callback, *perms);
3476 if (rc)
3477 goto err;
3478 }
3479
3480 rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3481 *perms);
3482 if (rc)
3483 goto err;
3484
3485out:
3486 return rc;
3487
3488err:
3489 for (i = 0; i < *nperms; i++)
3490 kfree((*perms)[i]);
3491 kfree(*perms);
3492 return rc;
3493}
3494
3495int security_get_reject_unknown(struct selinux_state *state)
3496{
3497 struct selinux_policy *policy;
3498 int value;
3499
3500 if (!selinux_initialized(state))
3501 return 0;
3502
3503 rcu_read_lock();
3504 policy = rcu_dereference(state->policy);
3505 value = policy->policydb.reject_unknown;
3506 rcu_read_unlock();
3507 return value;
3508}
3509
3510int security_get_allow_unknown(struct selinux_state *state)
3511{
3512 struct selinux_policy *policy;
3513 int value;
3514
3515 if (!selinux_initialized(state))
3516 return 0;
3517
3518 rcu_read_lock();
3519 policy = rcu_dereference(state->policy);
3520 value = policy->policydb.allow_unknown;
3521 rcu_read_unlock();
3522 return value;
3523}
3524
3525/**
3526 * security_policycap_supported - Check for a specific policy capability
3527 * @state: SELinux state
3528 * @req_cap: capability
3529 *
3530 * Description:
3531 * This function queries the currently loaded policy to see if it supports the
3532 * capability specified by @req_cap. Returns true (1) if the capability is
3533 * supported, false (0) if it isn't supported.
3534 *
3535 */
3536int security_policycap_supported(struct selinux_state *state,
3537 unsigned int req_cap)
3538{
3539 struct selinux_policy *policy;
3540 int rc;
3541
3542 if (!selinux_initialized(state))
3543 return 0;
3544
3545 rcu_read_lock();
3546 policy = rcu_dereference(state->policy);
3547 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3548 rcu_read_unlock();
3549
3550 return rc;
3551}
3552
3553struct selinux_audit_rule {
3554 u32 au_seqno;
3555 struct context au_ctxt;
3556};
3557
3558void selinux_audit_rule_free(void *vrule)
3559{
3560 struct selinux_audit_rule *rule = vrule;
3561
3562 if (rule) {
3563 context_destroy(&rule->au_ctxt);
3564 kfree(rule);
3565 }
3566}
3567
3568int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3569{
3570 struct selinux_state *state = &selinux_state;
3571 struct selinux_policy *policy;
3572 struct policydb *policydb;
3573 struct selinux_audit_rule *tmprule;
3574 struct role_datum *roledatum;
3575 struct type_datum *typedatum;
3576 struct user_datum *userdatum;
3577 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3578 int rc = 0;
3579
3580 *rule = NULL;
3581
3582 if (!selinux_initialized(state))
3583 return -EOPNOTSUPP;
3584
3585 switch (field) {
3586 case AUDIT_SUBJ_USER:
3587 case AUDIT_SUBJ_ROLE:
3588 case AUDIT_SUBJ_TYPE:
3589 case AUDIT_OBJ_USER:
3590 case AUDIT_OBJ_ROLE:
3591 case AUDIT_OBJ_TYPE:
3592 /* only 'equals' and 'not equals' fit user, role, and type */
3593 if (op != Audit_equal && op != Audit_not_equal)
3594 return -EINVAL;
3595 break;
3596 case AUDIT_SUBJ_SEN:
3597 case AUDIT_SUBJ_CLR:
3598 case AUDIT_OBJ_LEV_LOW:
3599 case AUDIT_OBJ_LEV_HIGH:
3600 /* we do not allow a range, indicated by the presence of '-' */
3601 if (strchr(rulestr, '-'))
3602 return -EINVAL;
3603 break;
3604 default:
3605 /* only the above fields are valid */
3606 return -EINVAL;
3607 }
3608
3609 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3610 if (!tmprule)
3611 return -ENOMEM;
3612
3613 context_init(&tmprule->au_ctxt);
3614
3615 rcu_read_lock();
3616 policy = rcu_dereference(state->policy);
3617 policydb = &policy->policydb;
3618
3619 tmprule->au_seqno = policy->latest_granting;
3620
3621 switch (field) {
3622 case AUDIT_SUBJ_USER:
3623 case AUDIT_OBJ_USER:
3624 rc = -EINVAL;
3625 userdatum = symtab_search(&policydb->p_users, rulestr);
3626 if (!userdatum)
3627 goto out;
3628 tmprule->au_ctxt.user = userdatum->value;
3629 break;
3630 case AUDIT_SUBJ_ROLE:
3631 case AUDIT_OBJ_ROLE:
3632 rc = -EINVAL;
3633 roledatum = symtab_search(&policydb->p_roles, rulestr);
3634 if (!roledatum)
3635 goto out;
3636 tmprule->au_ctxt.role = roledatum->value;
3637 break;
3638 case AUDIT_SUBJ_TYPE:
3639 case AUDIT_OBJ_TYPE:
3640 rc = -EINVAL;
3641 typedatum = symtab_search(&policydb->p_types, rulestr);
3642 if (!typedatum)
3643 goto out;
3644 tmprule->au_ctxt.type = typedatum->value;
3645 break;
3646 case AUDIT_SUBJ_SEN:
3647 case AUDIT_SUBJ_CLR:
3648 case AUDIT_OBJ_LEV_LOW:
3649 case AUDIT_OBJ_LEV_HIGH:
3650 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3651 GFP_ATOMIC);
3652 if (rc)
3653 goto out;
3654 break;
3655 }
3656 rc = 0;
3657out:
3658 rcu_read_unlock();
3659
3660 if (rc) {
3661 selinux_audit_rule_free(tmprule);
3662 tmprule = NULL;
3663 }
3664
3665 *rule = tmprule;
3666
3667 return rc;
3668}
3669
3670/* Check to see if the rule contains any selinux fields */
3671int selinux_audit_rule_known(struct audit_krule *rule)
3672{
3673 int i;
3674
3675 for (i = 0; i < rule->field_count; i++) {
3676 struct audit_field *f = &rule->fields[i];
3677 switch (f->type) {
3678 case AUDIT_SUBJ_USER:
3679 case AUDIT_SUBJ_ROLE:
3680 case AUDIT_SUBJ_TYPE:
3681 case AUDIT_SUBJ_SEN:
3682 case AUDIT_SUBJ_CLR:
3683 case AUDIT_OBJ_USER:
3684 case AUDIT_OBJ_ROLE:
3685 case AUDIT_OBJ_TYPE:
3686 case AUDIT_OBJ_LEV_LOW:
3687 case AUDIT_OBJ_LEV_HIGH:
3688 return 1;
3689 }
3690 }
3691
3692 return 0;
3693}
3694
3695int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3696{
3697 struct selinux_state *state = &selinux_state;
3698 struct selinux_policy *policy;
3699 struct context *ctxt;
3700 struct mls_level *level;
3701 struct selinux_audit_rule *rule = vrule;
3702 int match = 0;
3703
3704 if (unlikely(!rule)) {
3705 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3706 return -ENOENT;
3707 }
3708
3709 if (!selinux_initialized(state))
3710 return 0;
3711
3712 rcu_read_lock();
3713
3714 policy = rcu_dereference(state->policy);
3715
3716 if (rule->au_seqno < policy->latest_granting) {
3717 match = -ESTALE;
3718 goto out;
3719 }
3720
3721 ctxt = sidtab_search(policy->sidtab, sid);
3722 if (unlikely(!ctxt)) {
3723 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3724 sid);
3725 match = -ENOENT;
3726 goto out;
3727 }
3728
3729 /* a field/op pair that is not caught here will simply fall through
3730 without a match */
3731 switch (field) {
3732 case AUDIT_SUBJ_USER:
3733 case AUDIT_OBJ_USER:
3734 switch (op) {
3735 case Audit_equal:
3736 match = (ctxt->user == rule->au_ctxt.user);
3737 break;
3738 case Audit_not_equal:
3739 match = (ctxt->user != rule->au_ctxt.user);
3740 break;
3741 }
3742 break;
3743 case AUDIT_SUBJ_ROLE:
3744 case AUDIT_OBJ_ROLE:
3745 switch (op) {
3746 case Audit_equal:
3747 match = (ctxt->role == rule->au_ctxt.role);
3748 break;
3749 case Audit_not_equal:
3750 match = (ctxt->role != rule->au_ctxt.role);
3751 break;
3752 }
3753 break;
3754 case AUDIT_SUBJ_TYPE:
3755 case AUDIT_OBJ_TYPE:
3756 switch (op) {
3757 case Audit_equal:
3758 match = (ctxt->type == rule->au_ctxt.type);
3759 break;
3760 case Audit_not_equal:
3761 match = (ctxt->type != rule->au_ctxt.type);
3762 break;
3763 }
3764 break;
3765 case AUDIT_SUBJ_SEN:
3766 case AUDIT_SUBJ_CLR:
3767 case AUDIT_OBJ_LEV_LOW:
3768 case AUDIT_OBJ_LEV_HIGH:
3769 level = ((field == AUDIT_SUBJ_SEN ||
3770 field == AUDIT_OBJ_LEV_LOW) ?
3771 &ctxt->range.level[0] : &ctxt->range.level[1]);
3772 switch (op) {
3773 case Audit_equal:
3774 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3775 level);
3776 break;
3777 case Audit_not_equal:
3778 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3779 level);
3780 break;
3781 case Audit_lt:
3782 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3783 level) &&
3784 !mls_level_eq(&rule->au_ctxt.range.level[0],
3785 level));
3786 break;
3787 case Audit_le:
3788 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3789 level);
3790 break;
3791 case Audit_gt:
3792 match = (mls_level_dom(level,
3793 &rule->au_ctxt.range.level[0]) &&
3794 !mls_level_eq(level,
3795 &rule->au_ctxt.range.level[0]));
3796 break;
3797 case Audit_ge:
3798 match = mls_level_dom(level,
3799 &rule->au_ctxt.range.level[0]);
3800 break;
3801 }
3802 }
3803
3804out:
3805 rcu_read_unlock();
3806 return match;
3807}
3808
3809static int aurule_avc_callback(u32 event)
3810{
3811 if (event == AVC_CALLBACK_RESET)
3812 return audit_update_lsm_rules();
3813 return 0;
3814}
3815
3816static int __init aurule_init(void)
3817{
3818 int err;
3819
3820 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3821 if (err)
3822 panic("avc_add_callback() failed, error %d\n", err);
3823
3824 return err;
3825}
3826__initcall(aurule_init);
3827
3828#ifdef CONFIG_NETLABEL
3829/**
3830 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3831 * @secattr: the NetLabel packet security attributes
3832 * @sid: the SELinux SID
3833 *
3834 * Description:
3835 * Attempt to cache the context in @ctx, which was derived from the packet in
3836 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3837 * already been initialized.
3838 *
3839 */
3840static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3841 u32 sid)
3842{
3843 u32 *sid_cache;
3844
3845 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3846 if (sid_cache == NULL)
3847 return;
3848 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3849 if (secattr->cache == NULL) {
3850 kfree(sid_cache);
3851 return;
3852 }
3853
3854 *sid_cache = sid;
3855 secattr->cache->free = kfree;
3856 secattr->cache->data = sid_cache;
3857 secattr->flags |= NETLBL_SECATTR_CACHE;
3858}
3859
3860/**
3861 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3862 * @state: SELinux state
3863 * @secattr: the NetLabel packet security attributes
3864 * @sid: the SELinux SID
3865 *
3866 * Description:
3867 * Convert the given NetLabel security attributes in @secattr into a
3868 * SELinux SID. If the @secattr field does not contain a full SELinux
3869 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3870 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3871 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3872 * conversion for future lookups. Returns zero on success, negative values on
3873 * failure.
3874 *
3875 */
3876int security_netlbl_secattr_to_sid(struct selinux_state *state,
3877 struct netlbl_lsm_secattr *secattr,
3878 u32 *sid)
3879{
3880 struct selinux_policy *policy;
3881 struct policydb *policydb;
3882 struct sidtab *sidtab;
3883 int rc;
3884 struct context *ctx;
3885 struct context ctx_new;
3886
3887 if (!selinux_initialized(state)) {
3888 *sid = SECSID_NULL;
3889 return 0;
3890 }
3891
3892retry:
3893 rc = 0;
3894 rcu_read_lock();
3895 policy = rcu_dereference(state->policy);
3896 policydb = &policy->policydb;
3897 sidtab = policy->sidtab;
3898
3899 if (secattr->flags & NETLBL_SECATTR_CACHE)
3900 *sid = *(u32 *)secattr->cache->data;
3901 else if (secattr->flags & NETLBL_SECATTR_SECID)
3902 *sid = secattr->attr.secid;
3903 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3904 rc = -EIDRM;
3905 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3906 if (ctx == NULL)
3907 goto out;
3908
3909 context_init(&ctx_new);
3910 ctx_new.user = ctx->user;
3911 ctx_new.role = ctx->role;
3912 ctx_new.type = ctx->type;
3913 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3914 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3915 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3916 if (rc)
3917 goto out;
3918 }
3919 rc = -EIDRM;
3920 if (!mls_context_isvalid(policydb, &ctx_new)) {
3921 ebitmap_destroy(&ctx_new.range.level[0].cat);
3922 goto out;
3923 }
3924
3925 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3926 ebitmap_destroy(&ctx_new.range.level[0].cat);
3927 if (rc == -ESTALE) {
3928 rcu_read_unlock();
3929 goto retry;
3930 }
3931 if (rc)
3932 goto out;
3933
3934 security_netlbl_cache_add(secattr, *sid);
3935 } else
3936 *sid = SECSID_NULL;
3937
3938out:
3939 rcu_read_unlock();
3940 return rc;
3941}
3942
3943/**
3944 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3945 * @state: SELinux state
3946 * @sid: the SELinux SID
3947 * @secattr: the NetLabel packet security attributes
3948 *
3949 * Description:
3950 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3951 * Returns zero on success, negative values on failure.
3952 *
3953 */
3954int security_netlbl_sid_to_secattr(struct selinux_state *state,
3955 u32 sid, struct netlbl_lsm_secattr *secattr)
3956{
3957 struct selinux_policy *policy;
3958 struct policydb *policydb;
3959 int rc;
3960 struct context *ctx;
3961
3962 if (!selinux_initialized(state))
3963 return 0;
3964
3965 rcu_read_lock();
3966 policy = rcu_dereference(state->policy);
3967 policydb = &policy->policydb;
3968
3969 rc = -ENOENT;
3970 ctx = sidtab_search(policy->sidtab, sid);
3971 if (ctx == NULL)
3972 goto out;
3973
3974 rc = -ENOMEM;
3975 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3976 GFP_ATOMIC);
3977 if (secattr->domain == NULL)
3978 goto out;
3979
3980 secattr->attr.secid = sid;
3981 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3982 mls_export_netlbl_lvl(policydb, ctx, secattr);
3983 rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3984out:
3985 rcu_read_unlock();
3986 return rc;
3987}
3988#endif /* CONFIG_NETLABEL */
3989
3990/**
3991 * __security_read_policy - read the policy.
3992 * @policy: SELinux policy
3993 * @data: binary policy data
3994 * @len: length of data in bytes
3995 *
3996 */
3997static int __security_read_policy(struct selinux_policy *policy,
3998 void *data, size_t *len)
3999{
4000 int rc;
4001 struct policy_file fp;
4002
4003 fp.data = data;
4004 fp.len = *len;
4005
4006 rc = policydb_write(&policy->policydb, &fp);
4007 if (rc)
4008 return rc;
4009
4010 *len = (unsigned long)fp.data - (unsigned long)data;
4011 return 0;
4012}
4013
4014/**
4015 * security_read_policy - read the policy.
4016 * @state: selinux_state
4017 * @data: binary policy data
4018 * @len: length of data in bytes
4019 *
4020 */
4021int security_read_policy(struct selinux_state *state,
4022 void **data, size_t *len)
4023{
4024 struct selinux_policy *policy;
4025
4026 policy = rcu_dereference_protected(
4027 state->policy, lockdep_is_held(&state->policy_mutex));
4028 if (!policy)
4029 return -EINVAL;
4030
4031 *len = policy->policydb.len;
4032 *data = vmalloc_user(*len);
4033 if (!*data)
4034 return -ENOMEM;
4035
4036 return __security_read_policy(policy, *data, len);
4037}
4038
4039/**
4040 * security_read_state_kernel - read the policy.
4041 * @state: selinux_state
4042 * @data: binary policy data
4043 * @len: length of data in bytes
4044 *
4045 * Allocates kernel memory for reading SELinux policy.
4046 * This function is for internal use only and should not
4047 * be used for returning data to user space.
4048 *
4049 * This function must be called with policy_mutex held.
4050 */
4051int security_read_state_kernel(struct selinux_state *state,
4052 void **data, size_t *len)
4053{
4054 struct selinux_policy *policy;
4055
4056 policy = rcu_dereference_protected(
4057 state->policy, lockdep_is_held(&state->policy_mutex));
4058 if (!policy)
4059 return -EINVAL;
4060
4061 *len = policy->policydb.len;
4062 *data = vmalloc(*len);
4063 if (!*data)
4064 return -ENOMEM;
4065
4066 return __security_read_policy(policy, *data, len);
4067}