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