Loading...
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;
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 target = flex_array_get_ptr(policydb.type_val_to_struct_array,
557 tcontext->type - 1);
558 BUG_ON(!target);
559
560 if (source->bounds) {
561 memset(&lo_avd, 0, sizeof(lo_avd));
562
563 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
564 lo_scontext.type = source->bounds;
565
566 context_struct_compute_av(&lo_scontext,
567 tcontext,
568 tclass,
569 &lo_avd,
570 NULL);
571 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
572 return; /* no masked permission */
573 masked = ~lo_avd.allowed & avd->allowed;
574 }
575
576 if (target->bounds) {
577 memset(&lo_avd, 0, sizeof(lo_avd));
578
579 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
580 lo_tcontext.type = target->bounds;
581
582 context_struct_compute_av(scontext,
583 &lo_tcontext,
584 tclass,
585 &lo_avd,
586 NULL);
587 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
588 return; /* no masked permission */
589 masked = ~lo_avd.allowed & avd->allowed;
590 }
591
592 if (source->bounds && target->bounds) {
593 memset(&lo_avd, 0, sizeof(lo_avd));
594 /*
595 * lo_scontext and lo_tcontext are already
596 * set up.
597 */
598
599 context_struct_compute_av(&lo_scontext,
600 &lo_tcontext,
601 tclass,
602 &lo_avd,
603 NULL);
604 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
605 return; /* no masked permission */
606 masked = ~lo_avd.allowed & avd->allowed;
607 }
608
609 if (masked) {
610 /* mask violated permissions */
611 avd->allowed &= ~masked;
612
613 /* audit masked permissions */
614 security_dump_masked_av(scontext, tcontext,
615 tclass, masked, "bounds");
616 }
617}
618
619/*
620 * flag which drivers have permissions
621 * only looking for ioctl based extended permssions
622 */
623void services_compute_xperms_drivers(
624 struct extended_perms *xperms,
625 struct avtab_node *node)
626{
627 unsigned int i;
628
629 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
630 /* if one or more driver has all permissions allowed */
631 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
632 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
633 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
634 /* if allowing permissions within a driver */
635 security_xperm_set(xperms->drivers.p,
636 node->datum.u.xperms->driver);
637 }
638
639 /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
640 if (node->key.specified & AVTAB_XPERMS_ALLOWED)
641 xperms->len = 1;
642}
643
644/*
645 * Compute access vectors and extended permissions based on a context
646 * structure pair for the permissions in a particular class.
647 */
648static void context_struct_compute_av(struct context *scontext,
649 struct context *tcontext,
650 u16 tclass,
651 struct av_decision *avd,
652 struct extended_perms *xperms)
653{
654 struct constraint_node *constraint;
655 struct role_allow *ra;
656 struct avtab_key avkey;
657 struct avtab_node *node;
658 struct class_datum *tclass_datum;
659 struct ebitmap *sattr, *tattr;
660 struct ebitmap_node *snode, *tnode;
661 unsigned int i, j;
662
663 avd->allowed = 0;
664 avd->auditallow = 0;
665 avd->auditdeny = 0xffffffff;
666 if (xperms) {
667 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
668 xperms->len = 0;
669 }
670
671 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
672 if (printk_ratelimit())
673 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
674 return;
675 }
676
677 tclass_datum = policydb.class_val_to_struct[tclass - 1];
678
679 /*
680 * If a specific type enforcement rule was defined for
681 * this permission check, then use it.
682 */
683 avkey.target_class = tclass;
684 avkey.specified = AVTAB_AV | AVTAB_XPERMS;
685 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
686 BUG_ON(!sattr);
687 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
688 BUG_ON(!tattr);
689 ebitmap_for_each_positive_bit(sattr, snode, i) {
690 ebitmap_for_each_positive_bit(tattr, tnode, j) {
691 avkey.source_type = i + 1;
692 avkey.target_type = j + 1;
693 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
694 node;
695 node = avtab_search_node_next(node, avkey.specified)) {
696 if (node->key.specified == AVTAB_ALLOWED)
697 avd->allowed |= node->datum.u.data;
698 else if (node->key.specified == AVTAB_AUDITALLOW)
699 avd->auditallow |= node->datum.u.data;
700 else if (node->key.specified == AVTAB_AUDITDENY)
701 avd->auditdeny &= node->datum.u.data;
702 else if (xperms && (node->key.specified & AVTAB_XPERMS))
703 services_compute_xperms_drivers(xperms, node);
704 }
705
706 /* Check conditional av table for additional permissions */
707 cond_compute_av(&policydb.te_cond_avtab, &avkey,
708 avd, xperms);
709
710 }
711 }
712
713 /*
714 * Remove any permissions prohibited by a constraint (this includes
715 * the MLS policy).
716 */
717 constraint = tclass_datum->constraints;
718 while (constraint) {
719 if ((constraint->permissions & (avd->allowed)) &&
720 !constraint_expr_eval(scontext, tcontext, NULL,
721 constraint->expr)) {
722 avd->allowed &= ~(constraint->permissions);
723 }
724 constraint = constraint->next;
725 }
726
727 /*
728 * If checking process transition permission and the
729 * role is changing, then check the (current_role, new_role)
730 * pair.
731 */
732 if (tclass == policydb.process_class &&
733 (avd->allowed & policydb.process_trans_perms) &&
734 scontext->role != tcontext->role) {
735 for (ra = policydb.role_allow; ra; ra = ra->next) {
736 if (scontext->role == ra->role &&
737 tcontext->role == ra->new_role)
738 break;
739 }
740 if (!ra)
741 avd->allowed &= ~policydb.process_trans_perms;
742 }
743
744 /*
745 * If the given source and target types have boundary
746 * constraint, lazy checks have to mask any violated
747 * permission and notice it to userspace via audit.
748 */
749 type_attribute_bounds_av(scontext, tcontext,
750 tclass, avd);
751}
752
753static int security_validtrans_handle_fail(struct context *ocontext,
754 struct context *ncontext,
755 struct context *tcontext,
756 u16 tclass)
757{
758 char *o = NULL, *n = NULL, *t = NULL;
759 u32 olen, nlen, tlen;
760
761 if (context_struct_to_string(ocontext, &o, &olen))
762 goto out;
763 if (context_struct_to_string(ncontext, &n, &nlen))
764 goto out;
765 if (context_struct_to_string(tcontext, &t, &tlen))
766 goto out;
767 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
768 "op=security_validate_transition seresult=denied"
769 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
770 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
771out:
772 kfree(o);
773 kfree(n);
774 kfree(t);
775
776 if (!selinux_enforcing)
777 return 0;
778 return -EPERM;
779}
780
781static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
782 u16 orig_tclass, bool user)
783{
784 struct context *ocontext;
785 struct context *ncontext;
786 struct context *tcontext;
787 struct class_datum *tclass_datum;
788 struct constraint_node *constraint;
789 u16 tclass;
790 int rc = 0;
791
792 if (!ss_initialized)
793 return 0;
794
795 read_lock(&policy_rwlock);
796
797 if (!user)
798 tclass = unmap_class(orig_tclass);
799 else
800 tclass = orig_tclass;
801
802 if (!tclass || tclass > policydb.p_classes.nprim) {
803 rc = -EINVAL;
804 goto out;
805 }
806 tclass_datum = policydb.class_val_to_struct[tclass - 1];
807
808 ocontext = sidtab_search(&sidtab, oldsid);
809 if (!ocontext) {
810 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
811 __func__, oldsid);
812 rc = -EINVAL;
813 goto out;
814 }
815
816 ncontext = sidtab_search(&sidtab, newsid);
817 if (!ncontext) {
818 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
819 __func__, newsid);
820 rc = -EINVAL;
821 goto out;
822 }
823
824 tcontext = sidtab_search(&sidtab, tasksid);
825 if (!tcontext) {
826 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
827 __func__, tasksid);
828 rc = -EINVAL;
829 goto out;
830 }
831
832 constraint = tclass_datum->validatetrans;
833 while (constraint) {
834 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
835 constraint->expr)) {
836 if (user)
837 rc = -EPERM;
838 else
839 rc = security_validtrans_handle_fail(ocontext,
840 ncontext,
841 tcontext,
842 tclass);
843 goto out;
844 }
845 constraint = constraint->next;
846 }
847
848out:
849 read_unlock(&policy_rwlock);
850 return rc;
851}
852
853int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
854 u16 tclass)
855{
856 return security_compute_validatetrans(oldsid, newsid, tasksid,
857 tclass, true);
858}
859
860int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
861 u16 orig_tclass)
862{
863 return security_compute_validatetrans(oldsid, newsid, tasksid,
864 orig_tclass, false);
865}
866
867/*
868 * security_bounded_transition - check whether the given
869 * transition is directed to bounded, or not.
870 * It returns 0, if @newsid is bounded by @oldsid.
871 * Otherwise, it returns error code.
872 *
873 * @oldsid : current security identifier
874 * @newsid : destinated security identifier
875 */
876int security_bounded_transition(u32 old_sid, u32 new_sid)
877{
878 struct context *old_context, *new_context;
879 struct type_datum *type;
880 int index;
881 int rc;
882
883 read_lock(&policy_rwlock);
884
885 rc = -EINVAL;
886 old_context = sidtab_search(&sidtab, old_sid);
887 if (!old_context) {
888 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
889 __func__, old_sid);
890 goto out;
891 }
892
893 rc = -EINVAL;
894 new_context = sidtab_search(&sidtab, new_sid);
895 if (!new_context) {
896 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
897 __func__, new_sid);
898 goto out;
899 }
900
901 rc = 0;
902 /* type/domain unchanged */
903 if (old_context->type == new_context->type)
904 goto out;
905
906 index = new_context->type;
907 while (true) {
908 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
909 index - 1);
910 BUG_ON(!type);
911
912 /* not bounded anymore */
913 rc = -EPERM;
914 if (!type->bounds)
915 break;
916
917 /* @newsid is bounded by @oldsid */
918 rc = 0;
919 if (type->bounds == old_context->type)
920 break;
921
922 index = type->bounds;
923 }
924
925 if (rc) {
926 char *old_name = NULL;
927 char *new_name = NULL;
928 u32 length;
929
930 if (!context_struct_to_string(old_context,
931 &old_name, &length) &&
932 !context_struct_to_string(new_context,
933 &new_name, &length)) {
934 audit_log(current->audit_context,
935 GFP_ATOMIC, AUDIT_SELINUX_ERR,
936 "op=security_bounded_transition "
937 "seresult=denied "
938 "oldcontext=%s newcontext=%s",
939 old_name, new_name);
940 }
941 kfree(new_name);
942 kfree(old_name);
943 }
944out:
945 read_unlock(&policy_rwlock);
946
947 return rc;
948}
949
950static void avd_init(struct av_decision *avd)
951{
952 avd->allowed = 0;
953 avd->auditallow = 0;
954 avd->auditdeny = 0xffffffff;
955 avd->seqno = latest_granting;
956 avd->flags = 0;
957}
958
959void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
960 struct avtab_node *node)
961{
962 unsigned int i;
963
964 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
965 if (xpermd->driver != node->datum.u.xperms->driver)
966 return;
967 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
968 if (!security_xperm_test(node->datum.u.xperms->perms.p,
969 xpermd->driver))
970 return;
971 } else {
972 BUG();
973 }
974
975 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
976 xpermd->used |= XPERMS_ALLOWED;
977 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
978 memset(xpermd->allowed->p, 0xff,
979 sizeof(xpermd->allowed->p));
980 }
981 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
982 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
983 xpermd->allowed->p[i] |=
984 node->datum.u.xperms->perms.p[i];
985 }
986 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
987 xpermd->used |= XPERMS_AUDITALLOW;
988 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
989 memset(xpermd->auditallow->p, 0xff,
990 sizeof(xpermd->auditallow->p));
991 }
992 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
993 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
994 xpermd->auditallow->p[i] |=
995 node->datum.u.xperms->perms.p[i];
996 }
997 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
998 xpermd->used |= XPERMS_DONTAUDIT;
999 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
1000 memset(xpermd->dontaudit->p, 0xff,
1001 sizeof(xpermd->dontaudit->p));
1002 }
1003 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
1004 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
1005 xpermd->dontaudit->p[i] |=
1006 node->datum.u.xperms->perms.p[i];
1007 }
1008 } else {
1009 BUG();
1010 }
1011}
1012
1013void security_compute_xperms_decision(u32 ssid,
1014 u32 tsid,
1015 u16 orig_tclass,
1016 u8 driver,
1017 struct extended_perms_decision *xpermd)
1018{
1019 u16 tclass;
1020 struct context *scontext, *tcontext;
1021 struct avtab_key avkey;
1022 struct avtab_node *node;
1023 struct ebitmap *sattr, *tattr;
1024 struct ebitmap_node *snode, *tnode;
1025 unsigned int i, j;
1026
1027 xpermd->driver = driver;
1028 xpermd->used = 0;
1029 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1030 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1031 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1032
1033 read_lock(&policy_rwlock);
1034 if (!ss_initialized)
1035 goto allow;
1036
1037 scontext = sidtab_search(&sidtab, ssid);
1038 if (!scontext) {
1039 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1040 __func__, ssid);
1041 goto out;
1042 }
1043
1044 tcontext = sidtab_search(&sidtab, tsid);
1045 if (!tcontext) {
1046 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1047 __func__, tsid);
1048 goto out;
1049 }
1050
1051 tclass = unmap_class(orig_tclass);
1052 if (unlikely(orig_tclass && !tclass)) {
1053 if (policydb.allow_unknown)
1054 goto allow;
1055 goto out;
1056 }
1057
1058
1059 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1060 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1061 goto out;
1062 }
1063
1064 avkey.target_class = tclass;
1065 avkey.specified = AVTAB_XPERMS;
1066 sattr = flex_array_get(policydb.type_attr_map_array,
1067 scontext->type - 1);
1068 BUG_ON(!sattr);
1069 tattr = flex_array_get(policydb.type_attr_map_array,
1070 tcontext->type - 1);
1071 BUG_ON(!tattr);
1072 ebitmap_for_each_positive_bit(sattr, snode, i) {
1073 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1074 avkey.source_type = i + 1;
1075 avkey.target_type = j + 1;
1076 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1077 node;
1078 node = avtab_search_node_next(node, avkey.specified))
1079 services_compute_xperms_decision(xpermd, node);
1080
1081 cond_compute_xperms(&policydb.te_cond_avtab,
1082 &avkey, xpermd);
1083 }
1084 }
1085out:
1086 read_unlock(&policy_rwlock);
1087 return;
1088allow:
1089 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1090 goto out;
1091}
1092
1093/**
1094 * security_compute_av - Compute access vector decisions.
1095 * @ssid: source security identifier
1096 * @tsid: target security identifier
1097 * @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(u32 ssid,
1105 u32 tsid,
1106 u16 orig_tclass,
1107 struct av_decision *avd,
1108 struct extended_perms *xperms)
1109{
1110 u16 tclass;
1111 struct context *scontext = NULL, *tcontext = NULL;
1112
1113 read_lock(&policy_rwlock);
1114 avd_init(avd);
1115 xperms->len = 0;
1116 if (!ss_initialized)
1117 goto allow;
1118
1119 scontext = sidtab_search(&sidtab, ssid);
1120 if (!scontext) {
1121 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1122 __func__, ssid);
1123 goto out;
1124 }
1125
1126 /* permissive domain? */
1127 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1128 avd->flags |= AVD_FLAGS_PERMISSIVE;
1129
1130 tcontext = sidtab_search(&sidtab, tsid);
1131 if (!tcontext) {
1132 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1133 __func__, tsid);
1134 goto out;
1135 }
1136
1137 tclass = unmap_class(orig_tclass);
1138 if (unlikely(orig_tclass && !tclass)) {
1139 if (policydb.allow_unknown)
1140 goto allow;
1141 goto out;
1142 }
1143 context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1144 map_decision(orig_tclass, avd, policydb.allow_unknown);
1145out:
1146 read_unlock(&policy_rwlock);
1147 return;
1148allow:
1149 avd->allowed = 0xffffffff;
1150 goto out;
1151}
1152
1153void security_compute_av_user(u32 ssid,
1154 u32 tsid,
1155 u16 tclass,
1156 struct av_decision *avd)
1157{
1158 struct context *scontext = NULL, *tcontext = NULL;
1159
1160 read_lock(&policy_rwlock);
1161 avd_init(avd);
1162 if (!ss_initialized)
1163 goto allow;
1164
1165 scontext = sidtab_search(&sidtab, ssid);
1166 if (!scontext) {
1167 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1168 __func__, ssid);
1169 goto out;
1170 }
1171
1172 /* permissive domain? */
1173 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1174 avd->flags |= AVD_FLAGS_PERMISSIVE;
1175
1176 tcontext = sidtab_search(&sidtab, tsid);
1177 if (!tcontext) {
1178 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1179 __func__, tsid);
1180 goto out;
1181 }
1182
1183 if (unlikely(!tclass)) {
1184 if (policydb.allow_unknown)
1185 goto allow;
1186 goto out;
1187 }
1188
1189 context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1190 out:
1191 read_unlock(&policy_rwlock);
1192 return;
1193allow:
1194 avd->allowed = 0xffffffff;
1195 goto out;
1196}
1197
1198/*
1199 * Write the security context string representation of
1200 * the context structure `context' into a dynamically
1201 * allocated string of the correct size. Set `*scontext'
1202 * to point to this string and set `*scontext_len' to
1203 * the length of the string.
1204 */
1205static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1206{
1207 char *scontextp;
1208
1209 if (scontext)
1210 *scontext = NULL;
1211 *scontext_len = 0;
1212
1213 if (context->len) {
1214 *scontext_len = context->len;
1215 if (scontext) {
1216 *scontext = kstrdup(context->str, GFP_ATOMIC);
1217 if (!(*scontext))
1218 return -ENOMEM;
1219 }
1220 return 0;
1221 }
1222
1223 /* Compute the size of the context. */
1224 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1225 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1226 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1227 *scontext_len += mls_compute_context_len(context);
1228
1229 if (!scontext)
1230 return 0;
1231
1232 /* Allocate space for the context; caller must free this space. */
1233 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1234 if (!scontextp)
1235 return -ENOMEM;
1236 *scontext = scontextp;
1237
1238 /*
1239 * Copy the user name, role name and type name into the context.
1240 */
1241 scontextp += sprintf(scontextp, "%s:%s:%s",
1242 sym_name(&policydb, SYM_USERS, context->user - 1),
1243 sym_name(&policydb, SYM_ROLES, context->role - 1),
1244 sym_name(&policydb, SYM_TYPES, context->type - 1));
1245
1246 mls_sid_to_context(context, &scontextp);
1247
1248 *scontextp = 0;
1249
1250 return 0;
1251}
1252
1253#include "initial_sid_to_string.h"
1254
1255const char *security_get_initial_sid_context(u32 sid)
1256{
1257 if (unlikely(sid > SECINITSID_NUM))
1258 return NULL;
1259 return initial_sid_to_string[sid];
1260}
1261
1262static int security_sid_to_context_core(u32 sid, char **scontext,
1263 u32 *scontext_len, int force)
1264{
1265 struct context *context;
1266 int rc = 0;
1267
1268 if (scontext)
1269 *scontext = NULL;
1270 *scontext_len = 0;
1271
1272 if (!ss_initialized) {
1273 if (sid <= SECINITSID_NUM) {
1274 char *scontextp;
1275
1276 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1277 if (!scontext)
1278 goto out;
1279 scontextp = kmemdup(initial_sid_to_string[sid],
1280 *scontext_len, GFP_ATOMIC);
1281 if (!scontextp) {
1282 rc = -ENOMEM;
1283 goto out;
1284 }
1285 *scontext = scontextp;
1286 goto out;
1287 }
1288 printk(KERN_ERR "SELinux: %s: called before initial "
1289 "load_policy on unknown SID %d\n", __func__, sid);
1290 rc = -EINVAL;
1291 goto out;
1292 }
1293 read_lock(&policy_rwlock);
1294 if (force)
1295 context = sidtab_search_force(&sidtab, sid);
1296 else
1297 context = sidtab_search(&sidtab, sid);
1298 if (!context) {
1299 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1300 __func__, sid);
1301 rc = -EINVAL;
1302 goto out_unlock;
1303 }
1304 rc = context_struct_to_string(context, scontext, scontext_len);
1305out_unlock:
1306 read_unlock(&policy_rwlock);
1307out:
1308 return rc;
1309
1310}
1311
1312/**
1313 * security_sid_to_context - Obtain a context for a given SID.
1314 * @sid: security identifier, SID
1315 * @scontext: security context
1316 * @scontext_len: length in bytes
1317 *
1318 * Write the string representation of the context associated with @sid
1319 * into a dynamically allocated string of the correct size. Set @scontext
1320 * to point to this string and set @scontext_len to the length of the string.
1321 */
1322int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1323{
1324 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1325}
1326
1327int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1328{
1329 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1330}
1331
1332/*
1333 * Caveat: Mutates scontext.
1334 */
1335static int string_to_context_struct(struct policydb *pol,
1336 struct sidtab *sidtabp,
1337 char *scontext,
1338 u32 scontext_len,
1339 struct context *ctx,
1340 u32 def_sid)
1341{
1342 struct role_datum *role;
1343 struct type_datum *typdatum;
1344 struct user_datum *usrdatum;
1345 char *scontextp, *p, oldc;
1346 int rc = 0;
1347
1348 context_init(ctx);
1349
1350 /* Parse the security context. */
1351
1352 rc = -EINVAL;
1353 scontextp = (char *) scontext;
1354
1355 /* Extract the user. */
1356 p = scontextp;
1357 while (*p && *p != ':')
1358 p++;
1359
1360 if (*p == 0)
1361 goto out;
1362
1363 *p++ = 0;
1364
1365 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1366 if (!usrdatum)
1367 goto out;
1368
1369 ctx->user = usrdatum->value;
1370
1371 /* Extract role. */
1372 scontextp = p;
1373 while (*p && *p != ':')
1374 p++;
1375
1376 if (*p == 0)
1377 goto out;
1378
1379 *p++ = 0;
1380
1381 role = hashtab_search(pol->p_roles.table, scontextp);
1382 if (!role)
1383 goto out;
1384 ctx->role = role->value;
1385
1386 /* Extract type. */
1387 scontextp = p;
1388 while (*p && *p != ':')
1389 p++;
1390 oldc = *p;
1391 *p++ = 0;
1392
1393 typdatum = hashtab_search(pol->p_types.table, scontextp);
1394 if (!typdatum || typdatum->attribute)
1395 goto out;
1396
1397 ctx->type = typdatum->value;
1398
1399 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1400 if (rc)
1401 goto out;
1402
1403 rc = -EINVAL;
1404 if ((p - scontext) < scontext_len)
1405 goto out;
1406
1407 /* Check the validity of the new context. */
1408 if (!policydb_context_isvalid(pol, ctx))
1409 goto out;
1410 rc = 0;
1411out:
1412 if (rc)
1413 context_destroy(ctx);
1414 return rc;
1415}
1416
1417static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1418 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1419 int force)
1420{
1421 char *scontext2, *str = NULL;
1422 struct context context;
1423 int rc = 0;
1424
1425 /* An empty security context is never valid. */
1426 if (!scontext_len)
1427 return -EINVAL;
1428
1429 if (!ss_initialized) {
1430 int i;
1431
1432 for (i = 1; i < SECINITSID_NUM; i++) {
1433 if (!strcmp(initial_sid_to_string[i], scontext)) {
1434 *sid = i;
1435 return 0;
1436 }
1437 }
1438 *sid = SECINITSID_KERNEL;
1439 return 0;
1440 }
1441 *sid = SECSID_NULL;
1442
1443 /* Copy the string so that we can modify the copy as we parse it. */
1444 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1445 if (!scontext2)
1446 return -ENOMEM;
1447 memcpy(scontext2, scontext, scontext_len);
1448 scontext2[scontext_len] = 0;
1449
1450 if (force) {
1451 /* Save another copy for storing in uninterpreted form */
1452 rc = -ENOMEM;
1453 str = kstrdup(scontext2, gfp_flags);
1454 if (!str)
1455 goto out;
1456 }
1457
1458 read_lock(&policy_rwlock);
1459 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1460 scontext_len, &context, def_sid);
1461 if (rc == -EINVAL && force) {
1462 context.str = str;
1463 context.len = scontext_len;
1464 str = NULL;
1465 } else if (rc)
1466 goto out_unlock;
1467 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1468 context_destroy(&context);
1469out_unlock:
1470 read_unlock(&policy_rwlock);
1471out:
1472 kfree(scontext2);
1473 kfree(str);
1474 return rc;
1475}
1476
1477/**
1478 * security_context_to_sid - Obtain a SID for a given security context.
1479 * @scontext: security context
1480 * @scontext_len: length in bytes
1481 * @sid: security identifier, SID
1482 * @gfp: context for the allocation
1483 *
1484 * Obtains a SID associated with the security context that
1485 * has the string representation specified by @scontext.
1486 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1487 * memory is available, or 0 on success.
1488 */
1489int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1490 gfp_t gfp)
1491{
1492 return security_context_to_sid_core(scontext, scontext_len,
1493 sid, SECSID_NULL, gfp, 0);
1494}
1495
1496int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1497{
1498 return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1499}
1500
1501/**
1502 * security_context_to_sid_default - Obtain a SID for a given security context,
1503 * falling back to specified default if needed.
1504 *
1505 * @scontext: security context
1506 * @scontext_len: length in bytes
1507 * @sid: security identifier, SID
1508 * @def_sid: default SID to assign on error
1509 *
1510 * Obtains a SID associated with the security context that
1511 * has the string representation specified by @scontext.
1512 * The default SID is passed to the MLS layer to be used to allow
1513 * kernel labeling of the MLS field if the MLS field is not present
1514 * (for upgrading to MLS without full relabel).
1515 * Implicitly forces adding of the context even if it cannot be mapped yet.
1516 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1517 * memory is available, or 0 on success.
1518 */
1519int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1520 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1521{
1522 return security_context_to_sid_core(scontext, scontext_len,
1523 sid, def_sid, gfp_flags, 1);
1524}
1525
1526int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1527 u32 *sid)
1528{
1529 return security_context_to_sid_core(scontext, scontext_len,
1530 sid, SECSID_NULL, GFP_KERNEL, 1);
1531}
1532
1533static int compute_sid_handle_invalid_context(
1534 struct context *scontext,
1535 struct context *tcontext,
1536 u16 tclass,
1537 struct context *newcontext)
1538{
1539 char *s = NULL, *t = NULL, *n = NULL;
1540 u32 slen, tlen, nlen;
1541
1542 if (context_struct_to_string(scontext, &s, &slen))
1543 goto out;
1544 if (context_struct_to_string(tcontext, &t, &tlen))
1545 goto out;
1546 if (context_struct_to_string(newcontext, &n, &nlen))
1547 goto out;
1548 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1549 "op=security_compute_sid invalid_context=%s"
1550 " scontext=%s"
1551 " tcontext=%s"
1552 " tclass=%s",
1553 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1554out:
1555 kfree(s);
1556 kfree(t);
1557 kfree(n);
1558 if (!selinux_enforcing)
1559 return 0;
1560 return -EACCES;
1561}
1562
1563static void filename_compute_type(struct policydb *p, struct context *newcontext,
1564 u32 stype, u32 ttype, u16 tclass,
1565 const char *objname)
1566{
1567 struct filename_trans ft;
1568 struct filename_trans_datum *otype;
1569
1570 /*
1571 * Most filename trans rules are going to live in specific directories
1572 * like /dev or /var/run. This bitmap will quickly skip rule searches
1573 * if the ttype does not contain any rules.
1574 */
1575 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1576 return;
1577
1578 ft.stype = stype;
1579 ft.ttype = ttype;
1580 ft.tclass = tclass;
1581 ft.name = objname;
1582
1583 otype = hashtab_search(p->filename_trans, &ft);
1584 if (otype)
1585 newcontext->type = otype->otype;
1586}
1587
1588static int security_compute_sid(u32 ssid,
1589 u32 tsid,
1590 u16 orig_tclass,
1591 u32 specified,
1592 const char *objname,
1593 u32 *out_sid,
1594 bool kern)
1595{
1596 struct class_datum *cladatum = NULL;
1597 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1598 struct role_trans *roletr = NULL;
1599 struct avtab_key avkey;
1600 struct avtab_datum *avdatum;
1601 struct avtab_node *node;
1602 u16 tclass;
1603 int rc = 0;
1604 bool sock;
1605
1606 if (!ss_initialized) {
1607 switch (orig_tclass) {
1608 case SECCLASS_PROCESS: /* kernel value */
1609 *out_sid = ssid;
1610 break;
1611 default:
1612 *out_sid = tsid;
1613 break;
1614 }
1615 goto out;
1616 }
1617
1618 context_init(&newcontext);
1619
1620 read_lock(&policy_rwlock);
1621
1622 if (kern) {
1623 tclass = unmap_class(orig_tclass);
1624 sock = security_is_socket_class(orig_tclass);
1625 } else {
1626 tclass = orig_tclass;
1627 sock = security_is_socket_class(map_class(tclass));
1628 }
1629
1630 scontext = sidtab_search(&sidtab, ssid);
1631 if (!scontext) {
1632 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1633 __func__, ssid);
1634 rc = -EINVAL;
1635 goto out_unlock;
1636 }
1637 tcontext = sidtab_search(&sidtab, tsid);
1638 if (!tcontext) {
1639 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1640 __func__, tsid);
1641 rc = -EINVAL;
1642 goto out_unlock;
1643 }
1644
1645 if (tclass && tclass <= policydb.p_classes.nprim)
1646 cladatum = policydb.class_val_to_struct[tclass - 1];
1647
1648 /* Set the user identity. */
1649 switch (specified) {
1650 case AVTAB_TRANSITION:
1651 case AVTAB_CHANGE:
1652 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1653 newcontext.user = tcontext->user;
1654 } else {
1655 /* notice this gets both DEFAULT_SOURCE and unset */
1656 /* Use the process user identity. */
1657 newcontext.user = scontext->user;
1658 }
1659 break;
1660 case AVTAB_MEMBER:
1661 /* Use the related object owner. */
1662 newcontext.user = tcontext->user;
1663 break;
1664 }
1665
1666 /* Set the role to default values. */
1667 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1668 newcontext.role = scontext->role;
1669 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1670 newcontext.role = tcontext->role;
1671 } else {
1672 if ((tclass == policydb.process_class) || (sock == true))
1673 newcontext.role = scontext->role;
1674 else
1675 newcontext.role = OBJECT_R_VAL;
1676 }
1677
1678 /* Set the type to default values. */
1679 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1680 newcontext.type = scontext->type;
1681 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1682 newcontext.type = tcontext->type;
1683 } else {
1684 if ((tclass == policydb.process_class) || (sock == true)) {
1685 /* Use the type of process. */
1686 newcontext.type = scontext->type;
1687 } else {
1688 /* Use the type of the related object. */
1689 newcontext.type = tcontext->type;
1690 }
1691 }
1692
1693 /* Look for a type transition/member/change rule. */
1694 avkey.source_type = scontext->type;
1695 avkey.target_type = tcontext->type;
1696 avkey.target_class = tclass;
1697 avkey.specified = specified;
1698 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1699
1700 /* If no permanent rule, also check for enabled conditional rules */
1701 if (!avdatum) {
1702 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1703 for (; node; node = avtab_search_node_next(node, specified)) {
1704 if (node->key.specified & AVTAB_ENABLED) {
1705 avdatum = &node->datum;
1706 break;
1707 }
1708 }
1709 }
1710
1711 if (avdatum) {
1712 /* Use the type from the type transition/member/change rule. */
1713 newcontext.type = avdatum->u.data;
1714 }
1715
1716 /* if we have a objname this is a file trans check so check those rules */
1717 if (objname)
1718 filename_compute_type(&policydb, &newcontext, scontext->type,
1719 tcontext->type, tclass, objname);
1720
1721 /* Check for class-specific changes. */
1722 if (specified & AVTAB_TRANSITION) {
1723 /* Look for a role transition rule. */
1724 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1725 if ((roletr->role == scontext->role) &&
1726 (roletr->type == tcontext->type) &&
1727 (roletr->tclass == tclass)) {
1728 /* Use the role transition rule. */
1729 newcontext.role = roletr->new_role;
1730 break;
1731 }
1732 }
1733 }
1734
1735 /* Set the MLS attributes.
1736 This is done last because it may allocate memory. */
1737 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1738 &newcontext, sock);
1739 if (rc)
1740 goto out_unlock;
1741
1742 /* Check the validity of the context. */
1743 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1744 rc = compute_sid_handle_invalid_context(scontext,
1745 tcontext,
1746 tclass,
1747 &newcontext);
1748 if (rc)
1749 goto out_unlock;
1750 }
1751 /* Obtain the sid for the context. */
1752 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1753out_unlock:
1754 read_unlock(&policy_rwlock);
1755 context_destroy(&newcontext);
1756out:
1757 return rc;
1758}
1759
1760/**
1761 * security_transition_sid - Compute the SID for a new subject/object.
1762 * @ssid: source security identifier
1763 * @tsid: target security identifier
1764 * @tclass: target security class
1765 * @out_sid: security identifier for new subject/object
1766 *
1767 * Compute a SID to use for labeling a new subject or object in the
1768 * class @tclass based on a SID pair (@ssid, @tsid).
1769 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1770 * if insufficient memory is available, or %0 if the new SID was
1771 * computed successfully.
1772 */
1773int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1774 const struct qstr *qstr, u32 *out_sid)
1775{
1776 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1777 qstr ? qstr->name : NULL, out_sid, true);
1778}
1779
1780int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1781 const char *objname, u32 *out_sid)
1782{
1783 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1784 objname, out_sid, false);
1785}
1786
1787/**
1788 * security_member_sid - Compute the SID for member selection.
1789 * @ssid: source security identifier
1790 * @tsid: target security identifier
1791 * @tclass: target security class
1792 * @out_sid: security identifier for selected member
1793 *
1794 * Compute a SID to use when selecting a member of a polyinstantiated
1795 * object of class @tclass based on a SID pair (@ssid, @tsid).
1796 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1797 * if insufficient memory is available, or %0 if the SID was
1798 * computed successfully.
1799 */
1800int security_member_sid(u32 ssid,
1801 u32 tsid,
1802 u16 tclass,
1803 u32 *out_sid)
1804{
1805 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1806 out_sid, false);
1807}
1808
1809/**
1810 * security_change_sid - Compute the SID for object relabeling.
1811 * @ssid: source security identifier
1812 * @tsid: target security identifier
1813 * @tclass: target security class
1814 * @out_sid: security identifier for selected member
1815 *
1816 * Compute a SID to use for relabeling an object of class @tclass
1817 * based on a SID pair (@ssid, @tsid).
1818 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1819 * if insufficient memory is available, or %0 if the SID was
1820 * computed successfully.
1821 */
1822int security_change_sid(u32 ssid,
1823 u32 tsid,
1824 u16 tclass,
1825 u32 *out_sid)
1826{
1827 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1828 out_sid, false);
1829}
1830
1831/* Clone the SID into the new SID table. */
1832static int clone_sid(u32 sid,
1833 struct context *context,
1834 void *arg)
1835{
1836 struct sidtab *s = arg;
1837
1838 if (sid > SECINITSID_NUM)
1839 return sidtab_insert(s, sid, context);
1840 else
1841 return 0;
1842}
1843
1844static inline int convert_context_handle_invalid_context(struct context *context)
1845{
1846 char *s;
1847 u32 len;
1848
1849 if (selinux_enforcing)
1850 return -EINVAL;
1851
1852 if (!context_struct_to_string(context, &s, &len)) {
1853 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1854 kfree(s);
1855 }
1856 return 0;
1857}
1858
1859struct convert_context_args {
1860 struct policydb *oldp;
1861 struct policydb *newp;
1862};
1863
1864/*
1865 * Convert the values in the security context
1866 * structure `c' from the values specified
1867 * in the policy `p->oldp' to the values specified
1868 * in the policy `p->newp'. Verify that the
1869 * context is valid under the new policy.
1870 */
1871static int convert_context(u32 key,
1872 struct context *c,
1873 void *p)
1874{
1875 struct convert_context_args *args;
1876 struct context oldc;
1877 struct ocontext *oc;
1878 struct mls_range *range;
1879 struct role_datum *role;
1880 struct type_datum *typdatum;
1881 struct user_datum *usrdatum;
1882 char *s;
1883 u32 len;
1884 int rc = 0;
1885
1886 if (key <= SECINITSID_NUM)
1887 goto out;
1888
1889 args = p;
1890
1891 if (c->str) {
1892 struct context ctx;
1893
1894 rc = -ENOMEM;
1895 s = kstrdup(c->str, GFP_KERNEL);
1896 if (!s)
1897 goto out;
1898
1899 rc = string_to_context_struct(args->newp, NULL, s,
1900 c->len, &ctx, SECSID_NULL);
1901 kfree(s);
1902 if (!rc) {
1903 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1904 c->str);
1905 /* Replace string with mapped representation. */
1906 kfree(c->str);
1907 memcpy(c, &ctx, sizeof(*c));
1908 goto out;
1909 } else if (rc == -EINVAL) {
1910 /* Retain string representation for later mapping. */
1911 rc = 0;
1912 goto out;
1913 } else {
1914 /* Other error condition, e.g. ENOMEM. */
1915 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1916 c->str, -rc);
1917 goto out;
1918 }
1919 }
1920
1921 rc = context_cpy(&oldc, c);
1922 if (rc)
1923 goto out;
1924
1925 /* Convert the user. */
1926 rc = -EINVAL;
1927 usrdatum = hashtab_search(args->newp->p_users.table,
1928 sym_name(args->oldp, SYM_USERS, c->user - 1));
1929 if (!usrdatum)
1930 goto bad;
1931 c->user = usrdatum->value;
1932
1933 /* Convert the role. */
1934 rc = -EINVAL;
1935 role = hashtab_search(args->newp->p_roles.table,
1936 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1937 if (!role)
1938 goto bad;
1939 c->role = role->value;
1940
1941 /* Convert the type. */
1942 rc = -EINVAL;
1943 typdatum = hashtab_search(args->newp->p_types.table,
1944 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1945 if (!typdatum)
1946 goto bad;
1947 c->type = typdatum->value;
1948
1949 /* Convert the MLS fields if dealing with MLS policies */
1950 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1951 rc = mls_convert_context(args->oldp, args->newp, c);
1952 if (rc)
1953 goto bad;
1954 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1955 /*
1956 * Switching between MLS and non-MLS policy:
1957 * free any storage used by the MLS fields in the
1958 * context for all existing entries in the sidtab.
1959 */
1960 mls_context_destroy(c);
1961 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1962 /*
1963 * Switching between non-MLS and MLS policy:
1964 * ensure that the MLS fields of the context for all
1965 * existing entries in the sidtab are filled in with a
1966 * suitable default value, likely taken from one of the
1967 * initial SIDs.
1968 */
1969 oc = args->newp->ocontexts[OCON_ISID];
1970 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1971 oc = oc->next;
1972 rc = -EINVAL;
1973 if (!oc) {
1974 printk(KERN_ERR "SELinux: unable to look up"
1975 " the initial SIDs list\n");
1976 goto bad;
1977 }
1978 range = &oc->context[0].range;
1979 rc = mls_range_set(c, range);
1980 if (rc)
1981 goto bad;
1982 }
1983
1984 /* Check the validity of the new context. */
1985 if (!policydb_context_isvalid(args->newp, c)) {
1986 rc = convert_context_handle_invalid_context(&oldc);
1987 if (rc)
1988 goto bad;
1989 }
1990
1991 context_destroy(&oldc);
1992
1993 rc = 0;
1994out:
1995 return rc;
1996bad:
1997 /* Map old representation to string and save it. */
1998 rc = context_struct_to_string(&oldc, &s, &len);
1999 if (rc)
2000 return rc;
2001 context_destroy(&oldc);
2002 context_destroy(c);
2003 c->str = s;
2004 c->len = len;
2005 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
2006 c->str);
2007 rc = 0;
2008 goto out;
2009}
2010
2011static void security_load_policycaps(void)
2012{
2013 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
2014 POLICYDB_CAPABILITY_NETPEER);
2015 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
2016 POLICYDB_CAPABILITY_OPENPERM);
2017 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
2018 POLICYDB_CAPABILITY_ALWAYSNETWORK);
2019}
2020
2021static int security_preserve_bools(struct policydb *p);
2022
2023/**
2024 * security_load_policy - Load a security policy configuration.
2025 * @data: binary policy data
2026 * @len: length of data in bytes
2027 *
2028 * Load a new set of security policy configuration data,
2029 * validate it and convert the SID table as necessary.
2030 * This function will flush the access vector cache after
2031 * loading the new policy.
2032 */
2033int security_load_policy(void *data, size_t len)
2034{
2035 struct policydb *oldpolicydb, *newpolicydb;
2036 struct sidtab oldsidtab, newsidtab;
2037 struct selinux_mapping *oldmap, *map = NULL;
2038 struct convert_context_args args;
2039 u32 seqno;
2040 u16 map_size;
2041 int rc = 0;
2042 struct policy_file file = { data, len }, *fp = &file;
2043
2044 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2045 if (!oldpolicydb) {
2046 rc = -ENOMEM;
2047 goto out;
2048 }
2049 newpolicydb = oldpolicydb + 1;
2050
2051 if (!ss_initialized) {
2052 avtab_cache_init();
2053 rc = policydb_read(&policydb, fp);
2054 if (rc) {
2055 avtab_cache_destroy();
2056 goto out;
2057 }
2058
2059 policydb.len = len;
2060 rc = selinux_set_mapping(&policydb, secclass_map,
2061 ¤t_mapping,
2062 ¤t_mapping_size);
2063 if (rc) {
2064 policydb_destroy(&policydb);
2065 avtab_cache_destroy();
2066 goto out;
2067 }
2068
2069 rc = policydb_load_isids(&policydb, &sidtab);
2070 if (rc) {
2071 policydb_destroy(&policydb);
2072 avtab_cache_destroy();
2073 goto out;
2074 }
2075
2076 security_load_policycaps();
2077 ss_initialized = 1;
2078 seqno = ++latest_granting;
2079 selinux_complete_init();
2080 avc_ss_reset(seqno);
2081 selnl_notify_policyload(seqno);
2082 selinux_status_update_policyload(seqno);
2083 selinux_netlbl_cache_invalidate();
2084 selinux_xfrm_notify_policyload();
2085 goto out;
2086 }
2087
2088#if 0
2089 sidtab_hash_eval(&sidtab, "sids");
2090#endif
2091
2092 rc = policydb_read(newpolicydb, fp);
2093 if (rc)
2094 goto out;
2095
2096 newpolicydb->len = len;
2097 /* If switching between different policy types, log MLS status */
2098 if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2099 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2100 else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2101 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2102
2103 rc = policydb_load_isids(newpolicydb, &newsidtab);
2104 if (rc) {
2105 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
2106 policydb_destroy(newpolicydb);
2107 goto out;
2108 }
2109
2110 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2111 if (rc)
2112 goto err;
2113
2114 rc = security_preserve_bools(newpolicydb);
2115 if (rc) {
2116 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
2117 goto err;
2118 }
2119
2120 /* Clone the SID table. */
2121 sidtab_shutdown(&sidtab);
2122
2123 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2124 if (rc)
2125 goto err;
2126
2127 /*
2128 * Convert the internal representations of contexts
2129 * in the new SID table.
2130 */
2131 args.oldp = &policydb;
2132 args.newp = newpolicydb;
2133 rc = sidtab_map(&newsidtab, convert_context, &args);
2134 if (rc) {
2135 printk(KERN_ERR "SELinux: unable to convert the internal"
2136 " representation of contexts in the new SID"
2137 " table\n");
2138 goto err;
2139 }
2140
2141 /* Save the old policydb and SID table to free later. */
2142 memcpy(oldpolicydb, &policydb, sizeof(policydb));
2143 sidtab_set(&oldsidtab, &sidtab);
2144
2145 /* Install the new policydb and SID table. */
2146 write_lock_irq(&policy_rwlock);
2147 memcpy(&policydb, newpolicydb, sizeof(policydb));
2148 sidtab_set(&sidtab, &newsidtab);
2149 security_load_policycaps();
2150 oldmap = current_mapping;
2151 current_mapping = map;
2152 current_mapping_size = map_size;
2153 seqno = ++latest_granting;
2154 write_unlock_irq(&policy_rwlock);
2155
2156 /* Free the old policydb and SID table. */
2157 policydb_destroy(oldpolicydb);
2158 sidtab_destroy(&oldsidtab);
2159 kfree(oldmap);
2160
2161 avc_ss_reset(seqno);
2162 selnl_notify_policyload(seqno);
2163 selinux_status_update_policyload(seqno);
2164 selinux_netlbl_cache_invalidate();
2165 selinux_xfrm_notify_policyload();
2166
2167 rc = 0;
2168 goto out;
2169
2170err:
2171 kfree(map);
2172 sidtab_destroy(&newsidtab);
2173 policydb_destroy(newpolicydb);
2174
2175out:
2176 kfree(oldpolicydb);
2177 return rc;
2178}
2179
2180size_t security_policydb_len(void)
2181{
2182 size_t len;
2183
2184 read_lock(&policy_rwlock);
2185 len = policydb.len;
2186 read_unlock(&policy_rwlock);
2187
2188 return len;
2189}
2190
2191/**
2192 * security_port_sid - Obtain the SID for a port.
2193 * @protocol: protocol number
2194 * @port: port number
2195 * @out_sid: security identifier
2196 */
2197int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2198{
2199 struct ocontext *c;
2200 int rc = 0;
2201
2202 read_lock(&policy_rwlock);
2203
2204 c = policydb.ocontexts[OCON_PORT];
2205 while (c) {
2206 if (c->u.port.protocol == protocol &&
2207 c->u.port.low_port <= port &&
2208 c->u.port.high_port >= port)
2209 break;
2210 c = c->next;
2211 }
2212
2213 if (c) {
2214 if (!c->sid[0]) {
2215 rc = sidtab_context_to_sid(&sidtab,
2216 &c->context[0],
2217 &c->sid[0]);
2218 if (rc)
2219 goto out;
2220 }
2221 *out_sid = c->sid[0];
2222 } else {
2223 *out_sid = SECINITSID_PORT;
2224 }
2225
2226out:
2227 read_unlock(&policy_rwlock);
2228 return rc;
2229}
2230
2231/**
2232 * security_netif_sid - Obtain the SID for a network interface.
2233 * @name: interface name
2234 * @if_sid: interface SID
2235 */
2236int security_netif_sid(char *name, u32 *if_sid)
2237{
2238 int rc = 0;
2239 struct ocontext *c;
2240
2241 read_lock(&policy_rwlock);
2242
2243 c = policydb.ocontexts[OCON_NETIF];
2244 while (c) {
2245 if (strcmp(name, c->u.name) == 0)
2246 break;
2247 c = c->next;
2248 }
2249
2250 if (c) {
2251 if (!c->sid[0] || !c->sid[1]) {
2252 rc = sidtab_context_to_sid(&sidtab,
2253 &c->context[0],
2254 &c->sid[0]);
2255 if (rc)
2256 goto out;
2257 rc = sidtab_context_to_sid(&sidtab,
2258 &c->context[1],
2259 &c->sid[1]);
2260 if (rc)
2261 goto out;
2262 }
2263 *if_sid = c->sid[0];
2264 } else
2265 *if_sid = SECINITSID_NETIF;
2266
2267out:
2268 read_unlock(&policy_rwlock);
2269 return rc;
2270}
2271
2272static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2273{
2274 int i, fail = 0;
2275
2276 for (i = 0; i < 4; i++)
2277 if (addr[i] != (input[i] & mask[i])) {
2278 fail = 1;
2279 break;
2280 }
2281
2282 return !fail;
2283}
2284
2285/**
2286 * security_node_sid - Obtain the SID for a node (host).
2287 * @domain: communication domain aka address family
2288 * @addrp: address
2289 * @addrlen: address length in bytes
2290 * @out_sid: security identifier
2291 */
2292int security_node_sid(u16 domain,
2293 void *addrp,
2294 u32 addrlen,
2295 u32 *out_sid)
2296{
2297 int rc;
2298 struct ocontext *c;
2299
2300 read_lock(&policy_rwlock);
2301
2302 switch (domain) {
2303 case AF_INET: {
2304 u32 addr;
2305
2306 rc = -EINVAL;
2307 if (addrlen != sizeof(u32))
2308 goto out;
2309
2310 addr = *((u32 *)addrp);
2311
2312 c = policydb.ocontexts[OCON_NODE];
2313 while (c) {
2314 if (c->u.node.addr == (addr & c->u.node.mask))
2315 break;
2316 c = c->next;
2317 }
2318 break;
2319 }
2320
2321 case AF_INET6:
2322 rc = -EINVAL;
2323 if (addrlen != sizeof(u64) * 2)
2324 goto out;
2325 c = policydb.ocontexts[OCON_NODE6];
2326 while (c) {
2327 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2328 c->u.node6.mask))
2329 break;
2330 c = c->next;
2331 }
2332 break;
2333
2334 default:
2335 rc = 0;
2336 *out_sid = SECINITSID_NODE;
2337 goto out;
2338 }
2339
2340 if (c) {
2341 if (!c->sid[0]) {
2342 rc = sidtab_context_to_sid(&sidtab,
2343 &c->context[0],
2344 &c->sid[0]);
2345 if (rc)
2346 goto out;
2347 }
2348 *out_sid = c->sid[0];
2349 } else {
2350 *out_sid = SECINITSID_NODE;
2351 }
2352
2353 rc = 0;
2354out:
2355 read_unlock(&policy_rwlock);
2356 return rc;
2357}
2358
2359#define SIDS_NEL 25
2360
2361/**
2362 * security_get_user_sids - Obtain reachable SIDs for a user.
2363 * @fromsid: starting SID
2364 * @username: username
2365 * @sids: array of reachable SIDs for user
2366 * @nel: number of elements in @sids
2367 *
2368 * Generate the set of SIDs for legal security contexts
2369 * for a given user that can be reached by @fromsid.
2370 * Set *@sids to point to a dynamically allocated
2371 * array containing the set of SIDs. Set *@nel to the
2372 * number of elements in the array.
2373 */
2374
2375int security_get_user_sids(u32 fromsid,
2376 char *username,
2377 u32 **sids,
2378 u32 *nel)
2379{
2380 struct context *fromcon, usercon;
2381 u32 *mysids = NULL, *mysids2, sid;
2382 u32 mynel = 0, maxnel = SIDS_NEL;
2383 struct user_datum *user;
2384 struct role_datum *role;
2385 struct ebitmap_node *rnode, *tnode;
2386 int rc = 0, i, j;
2387
2388 *sids = NULL;
2389 *nel = 0;
2390
2391 if (!ss_initialized)
2392 goto out;
2393
2394 read_lock(&policy_rwlock);
2395
2396 context_init(&usercon);
2397
2398 rc = -EINVAL;
2399 fromcon = sidtab_search(&sidtab, fromsid);
2400 if (!fromcon)
2401 goto out_unlock;
2402
2403 rc = -EINVAL;
2404 user = hashtab_search(policydb.p_users.table, username);
2405 if (!user)
2406 goto out_unlock;
2407
2408 usercon.user = user->value;
2409
2410 rc = -ENOMEM;
2411 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2412 if (!mysids)
2413 goto out_unlock;
2414
2415 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2416 role = policydb.role_val_to_struct[i];
2417 usercon.role = i + 1;
2418 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2419 usercon.type = j + 1;
2420
2421 if (mls_setup_user_range(fromcon, user, &usercon))
2422 continue;
2423
2424 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2425 if (rc)
2426 goto out_unlock;
2427 if (mynel < maxnel) {
2428 mysids[mynel++] = sid;
2429 } else {
2430 rc = -ENOMEM;
2431 maxnel += SIDS_NEL;
2432 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2433 if (!mysids2)
2434 goto out_unlock;
2435 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2436 kfree(mysids);
2437 mysids = mysids2;
2438 mysids[mynel++] = sid;
2439 }
2440 }
2441 }
2442 rc = 0;
2443out_unlock:
2444 read_unlock(&policy_rwlock);
2445 if (rc || !mynel) {
2446 kfree(mysids);
2447 goto out;
2448 }
2449
2450 rc = -ENOMEM;
2451 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2452 if (!mysids2) {
2453 kfree(mysids);
2454 goto out;
2455 }
2456 for (i = 0, j = 0; i < mynel; i++) {
2457 struct av_decision dummy_avd;
2458 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2459 SECCLASS_PROCESS, /* kernel value */
2460 PROCESS__TRANSITION, AVC_STRICT,
2461 &dummy_avd);
2462 if (!rc)
2463 mysids2[j++] = mysids[i];
2464 cond_resched();
2465 }
2466 rc = 0;
2467 kfree(mysids);
2468 *sids = mysids2;
2469 *nel = j;
2470out:
2471 return rc;
2472}
2473
2474/**
2475 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2476 * @fstype: filesystem type
2477 * @path: path from root of mount
2478 * @sclass: file security class
2479 * @sid: SID for path
2480 *
2481 * Obtain a SID to use for a file in a filesystem that
2482 * cannot support xattr or use a fixed labeling behavior like
2483 * transition SIDs or task SIDs.
2484 *
2485 * The caller must acquire the policy_rwlock before calling this function.
2486 */
2487static inline int __security_genfs_sid(const char *fstype,
2488 char *path,
2489 u16 orig_sclass,
2490 u32 *sid)
2491{
2492 int len;
2493 u16 sclass;
2494 struct genfs *genfs;
2495 struct ocontext *c;
2496 int rc, cmp = 0;
2497
2498 while (path[0] == '/' && path[1] == '/')
2499 path++;
2500
2501 sclass = unmap_class(orig_sclass);
2502 *sid = SECINITSID_UNLABELED;
2503
2504 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2505 cmp = strcmp(fstype, genfs->fstype);
2506 if (cmp <= 0)
2507 break;
2508 }
2509
2510 rc = -ENOENT;
2511 if (!genfs || cmp)
2512 goto out;
2513
2514 for (c = genfs->head; c; c = c->next) {
2515 len = strlen(c->u.name);
2516 if ((!c->v.sclass || sclass == c->v.sclass) &&
2517 (strncmp(c->u.name, path, len) == 0))
2518 break;
2519 }
2520
2521 rc = -ENOENT;
2522 if (!c)
2523 goto out;
2524
2525 if (!c->sid[0]) {
2526 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2527 if (rc)
2528 goto out;
2529 }
2530
2531 *sid = c->sid[0];
2532 rc = 0;
2533out:
2534 return rc;
2535}
2536
2537/**
2538 * security_genfs_sid - Obtain a SID for a file in a filesystem
2539 * @fstype: filesystem type
2540 * @path: path from root of mount
2541 * @sclass: file security class
2542 * @sid: SID for path
2543 *
2544 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2545 * it afterward.
2546 */
2547int security_genfs_sid(const char *fstype,
2548 char *path,
2549 u16 orig_sclass,
2550 u32 *sid)
2551{
2552 int retval;
2553
2554 read_lock(&policy_rwlock);
2555 retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2556 read_unlock(&policy_rwlock);
2557 return retval;
2558}
2559
2560/**
2561 * security_fs_use - Determine how to handle labeling for a filesystem.
2562 * @sb: superblock in question
2563 */
2564int security_fs_use(struct super_block *sb)
2565{
2566 int rc = 0;
2567 struct ocontext *c;
2568 struct superblock_security_struct *sbsec = sb->s_security;
2569 const char *fstype = sb->s_type->name;
2570
2571 read_lock(&policy_rwlock);
2572
2573 c = policydb.ocontexts[OCON_FSUSE];
2574 while (c) {
2575 if (strcmp(fstype, c->u.name) == 0)
2576 break;
2577 c = c->next;
2578 }
2579
2580 if (c) {
2581 sbsec->behavior = c->v.behavior;
2582 if (!c->sid[0]) {
2583 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2584 &c->sid[0]);
2585 if (rc)
2586 goto out;
2587 }
2588 sbsec->sid = c->sid[0];
2589 } else {
2590 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2591 &sbsec->sid);
2592 if (rc) {
2593 sbsec->behavior = SECURITY_FS_USE_NONE;
2594 rc = 0;
2595 } else {
2596 sbsec->behavior = SECURITY_FS_USE_GENFS;
2597 }
2598 }
2599
2600out:
2601 read_unlock(&policy_rwlock);
2602 return rc;
2603}
2604
2605int security_get_bools(int *len, char ***names, int **values)
2606{
2607 int i, rc;
2608
2609 read_lock(&policy_rwlock);
2610 *names = NULL;
2611 *values = NULL;
2612
2613 rc = 0;
2614 *len = policydb.p_bools.nprim;
2615 if (!*len)
2616 goto out;
2617
2618 rc = -ENOMEM;
2619 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2620 if (!*names)
2621 goto err;
2622
2623 rc = -ENOMEM;
2624 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2625 if (!*values)
2626 goto err;
2627
2628 for (i = 0; i < *len; i++) {
2629 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2630
2631 rc = -ENOMEM;
2632 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2633 if (!(*names)[i])
2634 goto err;
2635 }
2636 rc = 0;
2637out:
2638 read_unlock(&policy_rwlock);
2639 return rc;
2640err:
2641 if (*names) {
2642 for (i = 0; i < *len; i++)
2643 kfree((*names)[i]);
2644 }
2645 kfree(*values);
2646 goto out;
2647}
2648
2649
2650int security_set_bools(int len, int *values)
2651{
2652 int i, rc;
2653 int lenp, seqno = 0;
2654 struct cond_node *cur;
2655
2656 write_lock_irq(&policy_rwlock);
2657
2658 rc = -EFAULT;
2659 lenp = policydb.p_bools.nprim;
2660 if (len != lenp)
2661 goto out;
2662
2663 for (i = 0; i < len; i++) {
2664 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2665 audit_log(current->audit_context, GFP_ATOMIC,
2666 AUDIT_MAC_CONFIG_CHANGE,
2667 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2668 sym_name(&policydb, SYM_BOOLS, i),
2669 !!values[i],
2670 policydb.bool_val_to_struct[i]->state,
2671 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2672 audit_get_sessionid(current));
2673 }
2674 if (values[i])
2675 policydb.bool_val_to_struct[i]->state = 1;
2676 else
2677 policydb.bool_val_to_struct[i]->state = 0;
2678 }
2679
2680 for (cur = policydb.cond_list; cur; cur = cur->next) {
2681 rc = evaluate_cond_node(&policydb, cur);
2682 if (rc)
2683 goto out;
2684 }
2685
2686 seqno = ++latest_granting;
2687 rc = 0;
2688out:
2689 write_unlock_irq(&policy_rwlock);
2690 if (!rc) {
2691 avc_ss_reset(seqno);
2692 selnl_notify_policyload(seqno);
2693 selinux_status_update_policyload(seqno);
2694 selinux_xfrm_notify_policyload();
2695 }
2696 return rc;
2697}
2698
2699int security_get_bool_value(int bool)
2700{
2701 int rc;
2702 int len;
2703
2704 read_lock(&policy_rwlock);
2705
2706 rc = -EFAULT;
2707 len = policydb.p_bools.nprim;
2708 if (bool >= len)
2709 goto out;
2710
2711 rc = policydb.bool_val_to_struct[bool]->state;
2712out:
2713 read_unlock(&policy_rwlock);
2714 return rc;
2715}
2716
2717static int security_preserve_bools(struct policydb *p)
2718{
2719 int rc, nbools = 0, *bvalues = NULL, i;
2720 char **bnames = NULL;
2721 struct cond_bool_datum *booldatum;
2722 struct cond_node *cur;
2723
2724 rc = security_get_bools(&nbools, &bnames, &bvalues);
2725 if (rc)
2726 goto out;
2727 for (i = 0; i < nbools; i++) {
2728 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2729 if (booldatum)
2730 booldatum->state = bvalues[i];
2731 }
2732 for (cur = p->cond_list; cur; cur = cur->next) {
2733 rc = evaluate_cond_node(p, cur);
2734 if (rc)
2735 goto out;
2736 }
2737
2738out:
2739 if (bnames) {
2740 for (i = 0; i < nbools; i++)
2741 kfree(bnames[i]);
2742 }
2743 kfree(bnames);
2744 kfree(bvalues);
2745 return rc;
2746}
2747
2748/*
2749 * security_sid_mls_copy() - computes a new sid based on the given
2750 * sid and the mls portion of mls_sid.
2751 */
2752int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2753{
2754 struct context *context1;
2755 struct context *context2;
2756 struct context newcon;
2757 char *s;
2758 u32 len;
2759 int rc;
2760
2761 rc = 0;
2762 if (!ss_initialized || !policydb.mls_enabled) {
2763 *new_sid = sid;
2764 goto out;
2765 }
2766
2767 context_init(&newcon);
2768
2769 read_lock(&policy_rwlock);
2770
2771 rc = -EINVAL;
2772 context1 = sidtab_search(&sidtab, sid);
2773 if (!context1) {
2774 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2775 __func__, sid);
2776 goto out_unlock;
2777 }
2778
2779 rc = -EINVAL;
2780 context2 = sidtab_search(&sidtab, mls_sid);
2781 if (!context2) {
2782 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2783 __func__, mls_sid);
2784 goto out_unlock;
2785 }
2786
2787 newcon.user = context1->user;
2788 newcon.role = context1->role;
2789 newcon.type = context1->type;
2790 rc = mls_context_cpy(&newcon, context2);
2791 if (rc)
2792 goto out_unlock;
2793
2794 /* Check the validity of the new context. */
2795 if (!policydb_context_isvalid(&policydb, &newcon)) {
2796 rc = convert_context_handle_invalid_context(&newcon);
2797 if (rc) {
2798 if (!context_struct_to_string(&newcon, &s, &len)) {
2799 audit_log(current->audit_context,
2800 GFP_ATOMIC, AUDIT_SELINUX_ERR,
2801 "op=security_sid_mls_copy "
2802 "invalid_context=%s", s);
2803 kfree(s);
2804 }
2805 goto out_unlock;
2806 }
2807 }
2808
2809 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2810out_unlock:
2811 read_unlock(&policy_rwlock);
2812 context_destroy(&newcon);
2813out:
2814 return rc;
2815}
2816
2817/**
2818 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2819 * @nlbl_sid: NetLabel SID
2820 * @nlbl_type: NetLabel labeling protocol type
2821 * @xfrm_sid: XFRM SID
2822 *
2823 * Description:
2824 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2825 * resolved into a single SID it is returned via @peer_sid and the function
2826 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2827 * returns a negative value. A table summarizing the behavior is below:
2828 *
2829 * | function return | @sid
2830 * ------------------------------+-----------------+-----------------
2831 * no peer labels | 0 | SECSID_NULL
2832 * single peer label | 0 | <peer_label>
2833 * multiple, consistent labels | 0 | <peer_label>
2834 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2835 *
2836 */
2837int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2838 u32 xfrm_sid,
2839 u32 *peer_sid)
2840{
2841 int rc;
2842 struct context *nlbl_ctx;
2843 struct context *xfrm_ctx;
2844
2845 *peer_sid = SECSID_NULL;
2846
2847 /* handle the common (which also happens to be the set of easy) cases
2848 * right away, these two if statements catch everything involving a
2849 * single or absent peer SID/label */
2850 if (xfrm_sid == SECSID_NULL) {
2851 *peer_sid = nlbl_sid;
2852 return 0;
2853 }
2854 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2855 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2856 * is present */
2857 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2858 *peer_sid = xfrm_sid;
2859 return 0;
2860 }
2861
2862 /* we don't need to check ss_initialized here since the only way both
2863 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2864 * security server was initialized and ss_initialized was true */
2865 if (!policydb.mls_enabled)
2866 return 0;
2867
2868 read_lock(&policy_rwlock);
2869
2870 rc = -EINVAL;
2871 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2872 if (!nlbl_ctx) {
2873 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2874 __func__, nlbl_sid);
2875 goto out;
2876 }
2877 rc = -EINVAL;
2878 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2879 if (!xfrm_ctx) {
2880 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2881 __func__, xfrm_sid);
2882 goto out;
2883 }
2884 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2885 if (rc)
2886 goto out;
2887
2888 /* at present NetLabel SIDs/labels really only carry MLS
2889 * information so if the MLS portion of the NetLabel SID
2890 * matches the MLS portion of the labeled XFRM SID/label
2891 * then pass along the XFRM SID as it is the most
2892 * expressive */
2893 *peer_sid = xfrm_sid;
2894out:
2895 read_unlock(&policy_rwlock);
2896 return rc;
2897}
2898
2899static int get_classes_callback(void *k, void *d, void *args)
2900{
2901 struct class_datum *datum = d;
2902 char *name = k, **classes = args;
2903 int value = datum->value - 1;
2904
2905 classes[value] = kstrdup(name, GFP_ATOMIC);
2906 if (!classes[value])
2907 return -ENOMEM;
2908
2909 return 0;
2910}
2911
2912int security_get_classes(char ***classes, int *nclasses)
2913{
2914 int rc;
2915
2916 read_lock(&policy_rwlock);
2917
2918 rc = -ENOMEM;
2919 *nclasses = policydb.p_classes.nprim;
2920 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2921 if (!*classes)
2922 goto out;
2923
2924 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2925 *classes);
2926 if (rc) {
2927 int i;
2928 for (i = 0; i < *nclasses; i++)
2929 kfree((*classes)[i]);
2930 kfree(*classes);
2931 }
2932
2933out:
2934 read_unlock(&policy_rwlock);
2935 return rc;
2936}
2937
2938static int get_permissions_callback(void *k, void *d, void *args)
2939{
2940 struct perm_datum *datum = d;
2941 char *name = k, **perms = args;
2942 int value = datum->value - 1;
2943
2944 perms[value] = kstrdup(name, GFP_ATOMIC);
2945 if (!perms[value])
2946 return -ENOMEM;
2947
2948 return 0;
2949}
2950
2951int security_get_permissions(char *class, char ***perms, int *nperms)
2952{
2953 int rc, i;
2954 struct class_datum *match;
2955
2956 read_lock(&policy_rwlock);
2957
2958 rc = -EINVAL;
2959 match = hashtab_search(policydb.p_classes.table, class);
2960 if (!match) {
2961 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2962 __func__, class);
2963 goto out;
2964 }
2965
2966 rc = -ENOMEM;
2967 *nperms = match->permissions.nprim;
2968 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2969 if (!*perms)
2970 goto out;
2971
2972 if (match->comdatum) {
2973 rc = hashtab_map(match->comdatum->permissions.table,
2974 get_permissions_callback, *perms);
2975 if (rc)
2976 goto err;
2977 }
2978
2979 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2980 *perms);
2981 if (rc)
2982 goto err;
2983
2984out:
2985 read_unlock(&policy_rwlock);
2986 return rc;
2987
2988err:
2989 read_unlock(&policy_rwlock);
2990 for (i = 0; i < *nperms; i++)
2991 kfree((*perms)[i]);
2992 kfree(*perms);
2993 return rc;
2994}
2995
2996int security_get_reject_unknown(void)
2997{
2998 return policydb.reject_unknown;
2999}
3000
3001int security_get_allow_unknown(void)
3002{
3003 return policydb.allow_unknown;
3004}
3005
3006/**
3007 * security_policycap_supported - Check for a specific policy capability
3008 * @req_cap: capability
3009 *
3010 * Description:
3011 * This function queries the currently loaded policy to see if it supports the
3012 * capability specified by @req_cap. Returns true (1) if the capability is
3013 * supported, false (0) if it isn't supported.
3014 *
3015 */
3016int security_policycap_supported(unsigned int req_cap)
3017{
3018 int rc;
3019
3020 read_lock(&policy_rwlock);
3021 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3022 read_unlock(&policy_rwlock);
3023
3024 return rc;
3025}
3026
3027struct selinux_audit_rule {
3028 u32 au_seqno;
3029 struct context au_ctxt;
3030};
3031
3032void selinux_audit_rule_free(void *vrule)
3033{
3034 struct selinux_audit_rule *rule = vrule;
3035
3036 if (rule) {
3037 context_destroy(&rule->au_ctxt);
3038 kfree(rule);
3039 }
3040}
3041
3042int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3043{
3044 struct selinux_audit_rule *tmprule;
3045 struct role_datum *roledatum;
3046 struct type_datum *typedatum;
3047 struct user_datum *userdatum;
3048 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3049 int rc = 0;
3050
3051 *rule = NULL;
3052
3053 if (!ss_initialized)
3054 return -EOPNOTSUPP;
3055
3056 switch (field) {
3057 case AUDIT_SUBJ_USER:
3058 case AUDIT_SUBJ_ROLE:
3059 case AUDIT_SUBJ_TYPE:
3060 case AUDIT_OBJ_USER:
3061 case AUDIT_OBJ_ROLE:
3062 case AUDIT_OBJ_TYPE:
3063 /* only 'equals' and 'not equals' fit user, role, and type */
3064 if (op != Audit_equal && op != Audit_not_equal)
3065 return -EINVAL;
3066 break;
3067 case AUDIT_SUBJ_SEN:
3068 case AUDIT_SUBJ_CLR:
3069 case AUDIT_OBJ_LEV_LOW:
3070 case AUDIT_OBJ_LEV_HIGH:
3071 /* we do not allow a range, indicated by the presence of '-' */
3072 if (strchr(rulestr, '-'))
3073 return -EINVAL;
3074 break;
3075 default:
3076 /* only the above fields are valid */
3077 return -EINVAL;
3078 }
3079
3080 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3081 if (!tmprule)
3082 return -ENOMEM;
3083
3084 context_init(&tmprule->au_ctxt);
3085
3086 read_lock(&policy_rwlock);
3087
3088 tmprule->au_seqno = latest_granting;
3089
3090 switch (field) {
3091 case AUDIT_SUBJ_USER:
3092 case AUDIT_OBJ_USER:
3093 rc = -EINVAL;
3094 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3095 if (!userdatum)
3096 goto out;
3097 tmprule->au_ctxt.user = userdatum->value;
3098 break;
3099 case AUDIT_SUBJ_ROLE:
3100 case AUDIT_OBJ_ROLE:
3101 rc = -EINVAL;
3102 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3103 if (!roledatum)
3104 goto out;
3105 tmprule->au_ctxt.role = roledatum->value;
3106 break;
3107 case AUDIT_SUBJ_TYPE:
3108 case AUDIT_OBJ_TYPE:
3109 rc = -EINVAL;
3110 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3111 if (!typedatum)
3112 goto out;
3113 tmprule->au_ctxt.type = typedatum->value;
3114 break;
3115 case AUDIT_SUBJ_SEN:
3116 case AUDIT_SUBJ_CLR:
3117 case AUDIT_OBJ_LEV_LOW:
3118 case AUDIT_OBJ_LEV_HIGH:
3119 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3120 if (rc)
3121 goto out;
3122 break;
3123 }
3124 rc = 0;
3125out:
3126 read_unlock(&policy_rwlock);
3127
3128 if (rc) {
3129 selinux_audit_rule_free(tmprule);
3130 tmprule = NULL;
3131 }
3132
3133 *rule = tmprule;
3134
3135 return rc;
3136}
3137
3138/* Check to see if the rule contains any selinux fields */
3139int selinux_audit_rule_known(struct audit_krule *rule)
3140{
3141 int i;
3142
3143 for (i = 0; i < rule->field_count; i++) {
3144 struct audit_field *f = &rule->fields[i];
3145 switch (f->type) {
3146 case AUDIT_SUBJ_USER:
3147 case AUDIT_SUBJ_ROLE:
3148 case AUDIT_SUBJ_TYPE:
3149 case AUDIT_SUBJ_SEN:
3150 case AUDIT_SUBJ_CLR:
3151 case AUDIT_OBJ_USER:
3152 case AUDIT_OBJ_ROLE:
3153 case AUDIT_OBJ_TYPE:
3154 case AUDIT_OBJ_LEV_LOW:
3155 case AUDIT_OBJ_LEV_HIGH:
3156 return 1;
3157 }
3158 }
3159
3160 return 0;
3161}
3162
3163int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3164 struct audit_context *actx)
3165{
3166 struct context *ctxt;
3167 struct mls_level *level;
3168 struct selinux_audit_rule *rule = vrule;
3169 int match = 0;
3170
3171 if (unlikely(!rule)) {
3172 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3173 return -ENOENT;
3174 }
3175
3176 read_lock(&policy_rwlock);
3177
3178 if (rule->au_seqno < latest_granting) {
3179 match = -ESTALE;
3180 goto out;
3181 }
3182
3183 ctxt = sidtab_search(&sidtab, sid);
3184 if (unlikely(!ctxt)) {
3185 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3186 sid);
3187 match = -ENOENT;
3188 goto out;
3189 }
3190
3191 /* a field/op pair that is not caught here will simply fall through
3192 without a match */
3193 switch (field) {
3194 case AUDIT_SUBJ_USER:
3195 case AUDIT_OBJ_USER:
3196 switch (op) {
3197 case Audit_equal:
3198 match = (ctxt->user == rule->au_ctxt.user);
3199 break;
3200 case Audit_not_equal:
3201 match = (ctxt->user != rule->au_ctxt.user);
3202 break;
3203 }
3204 break;
3205 case AUDIT_SUBJ_ROLE:
3206 case AUDIT_OBJ_ROLE:
3207 switch (op) {
3208 case Audit_equal:
3209 match = (ctxt->role == rule->au_ctxt.role);
3210 break;
3211 case Audit_not_equal:
3212 match = (ctxt->role != rule->au_ctxt.role);
3213 break;
3214 }
3215 break;
3216 case AUDIT_SUBJ_TYPE:
3217 case AUDIT_OBJ_TYPE:
3218 switch (op) {
3219 case Audit_equal:
3220 match = (ctxt->type == rule->au_ctxt.type);
3221 break;
3222 case Audit_not_equal:
3223 match = (ctxt->type != rule->au_ctxt.type);
3224 break;
3225 }
3226 break;
3227 case AUDIT_SUBJ_SEN:
3228 case AUDIT_SUBJ_CLR:
3229 case AUDIT_OBJ_LEV_LOW:
3230 case AUDIT_OBJ_LEV_HIGH:
3231 level = ((field == AUDIT_SUBJ_SEN ||
3232 field == AUDIT_OBJ_LEV_LOW) ?
3233 &ctxt->range.level[0] : &ctxt->range.level[1]);
3234 switch (op) {
3235 case Audit_equal:
3236 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3237 level);
3238 break;
3239 case Audit_not_equal:
3240 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3241 level);
3242 break;
3243 case Audit_lt:
3244 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3245 level) &&
3246 !mls_level_eq(&rule->au_ctxt.range.level[0],
3247 level));
3248 break;
3249 case Audit_le:
3250 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3251 level);
3252 break;
3253 case Audit_gt:
3254 match = (mls_level_dom(level,
3255 &rule->au_ctxt.range.level[0]) &&
3256 !mls_level_eq(level,
3257 &rule->au_ctxt.range.level[0]));
3258 break;
3259 case Audit_ge:
3260 match = mls_level_dom(level,
3261 &rule->au_ctxt.range.level[0]);
3262 break;
3263 }
3264 }
3265
3266out:
3267 read_unlock(&policy_rwlock);
3268 return match;
3269}
3270
3271static int (*aurule_callback)(void) = audit_update_lsm_rules;
3272
3273static int aurule_avc_callback(u32 event)
3274{
3275 int err = 0;
3276
3277 if (event == AVC_CALLBACK_RESET && aurule_callback)
3278 err = aurule_callback();
3279 return err;
3280}
3281
3282static int __init aurule_init(void)
3283{
3284 int err;
3285
3286 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3287 if (err)
3288 panic("avc_add_callback() failed, error %d\n", err);
3289
3290 return err;
3291}
3292__initcall(aurule_init);
3293
3294#ifdef CONFIG_NETLABEL
3295/**
3296 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3297 * @secattr: the NetLabel packet security attributes
3298 * @sid: the SELinux SID
3299 *
3300 * Description:
3301 * Attempt to cache the context in @ctx, which was derived from the packet in
3302 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3303 * already been initialized.
3304 *
3305 */
3306static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3307 u32 sid)
3308{
3309 u32 *sid_cache;
3310
3311 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3312 if (sid_cache == NULL)
3313 return;
3314 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3315 if (secattr->cache == NULL) {
3316 kfree(sid_cache);
3317 return;
3318 }
3319
3320 *sid_cache = sid;
3321 secattr->cache->free = kfree;
3322 secattr->cache->data = sid_cache;
3323 secattr->flags |= NETLBL_SECATTR_CACHE;
3324}
3325
3326/**
3327 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3328 * @secattr: the NetLabel packet security attributes
3329 * @sid: the SELinux SID
3330 *
3331 * Description:
3332 * Convert the given NetLabel security attributes in @secattr into a
3333 * SELinux SID. If the @secattr field does not contain a full SELinux
3334 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3335 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3336 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3337 * conversion for future lookups. Returns zero on success, negative values on
3338 * failure.
3339 *
3340 */
3341int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3342 u32 *sid)
3343{
3344 int rc;
3345 struct context *ctx;
3346 struct context ctx_new;
3347
3348 if (!ss_initialized) {
3349 *sid = SECSID_NULL;
3350 return 0;
3351 }
3352
3353 read_lock(&policy_rwlock);
3354
3355 if (secattr->flags & NETLBL_SECATTR_CACHE)
3356 *sid = *(u32 *)secattr->cache->data;
3357 else if (secattr->flags & NETLBL_SECATTR_SECID)
3358 *sid = secattr->attr.secid;
3359 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3360 rc = -EIDRM;
3361 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3362 if (ctx == NULL)
3363 goto out;
3364
3365 context_init(&ctx_new);
3366 ctx_new.user = ctx->user;
3367 ctx_new.role = ctx->role;
3368 ctx_new.type = ctx->type;
3369 mls_import_netlbl_lvl(&ctx_new, secattr);
3370 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3371 rc = mls_import_netlbl_cat(&ctx_new, secattr);
3372 if (rc)
3373 goto out;
3374 }
3375 rc = -EIDRM;
3376 if (!mls_context_isvalid(&policydb, &ctx_new))
3377 goto out_free;
3378
3379 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3380 if (rc)
3381 goto out_free;
3382
3383 security_netlbl_cache_add(secattr, *sid);
3384
3385 ebitmap_destroy(&ctx_new.range.level[0].cat);
3386 } else
3387 *sid = SECSID_NULL;
3388
3389 read_unlock(&policy_rwlock);
3390 return 0;
3391out_free:
3392 ebitmap_destroy(&ctx_new.range.level[0].cat);
3393out:
3394 read_unlock(&policy_rwlock);
3395 return rc;
3396}
3397
3398/**
3399 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3400 * @sid: the SELinux SID
3401 * @secattr: the NetLabel packet security attributes
3402 *
3403 * Description:
3404 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3405 * Returns zero on success, negative values on failure.
3406 *
3407 */
3408int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3409{
3410 int rc;
3411 struct context *ctx;
3412
3413 if (!ss_initialized)
3414 return 0;
3415
3416 read_lock(&policy_rwlock);
3417
3418 rc = -ENOENT;
3419 ctx = sidtab_search(&sidtab, sid);
3420 if (ctx == NULL)
3421 goto out;
3422
3423 rc = -ENOMEM;
3424 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3425 GFP_ATOMIC);
3426 if (secattr->domain == NULL)
3427 goto out;
3428
3429 secattr->attr.secid = sid;
3430 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3431 mls_export_netlbl_lvl(ctx, secattr);
3432 rc = mls_export_netlbl_cat(ctx, secattr);
3433out:
3434 read_unlock(&policy_rwlock);
3435 return rc;
3436}
3437#endif /* CONFIG_NETLABEL */
3438
3439/**
3440 * security_read_policy - read the policy.
3441 * @data: binary policy data
3442 * @len: length of data in bytes
3443 *
3444 */
3445int security_read_policy(void **data, size_t *len)
3446{
3447 int rc;
3448 struct policy_file fp;
3449
3450 if (!ss_initialized)
3451 return -EINVAL;
3452
3453 *len = security_policydb_len();
3454
3455 *data = vmalloc_user(*len);
3456 if (!*data)
3457 return -ENOMEM;
3458
3459 fp.data = *data;
3460 fp.len = *len;
3461
3462 read_lock(&policy_rwlock);
3463 rc = policydb_write(&policydb, &fp);
3464 read_unlock(&policy_rwlock);
3465
3466 if (rc)
3467 return rc;
3468
3469 *len = (unsigned long)fp.data - (unsigned long)*data;
3470 return 0;
3471
3472}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Implementation of the security services.
4 *
5 * Authors : Stephen Smalley, <stephen.smalley.work@gmail.com>
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 bool print_unknown_handle = false;
101
102 /* Find number of classes in the input mapping */
103 if (!map)
104 return -EINVAL;
105 i = 0;
106 while (map[i].name)
107 i++;
108
109 /* Allocate space for the class records, plus one for class zero */
110 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
111 if (!out_map->mapping)
112 return -ENOMEM;
113
114 /* Store the raw class and permission values */
115 j = 0;
116 while (map[j].name) {
117 const struct security_class_mapping *p_in = map + (j++);
118 struct selinux_mapping *p_out = out_map->mapping + j;
119 u16 k;
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 |= (u32)1<<i;
211 if (allow_unknown && !mapping->perms[i])
212 result |= (u32)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 |= (u32)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 |= (u32)1<<i;
224 if (!allow_unknown && !mapping->perms[i])
225 result |= (u32)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 |= (u32)1<<i;
234 avd->auditdeny = result;
235 }
236}
237
238int security_mls_enabled(void)
239{
240 int mls_enabled;
241 struct selinux_policy *policy;
242
243 if (!selinux_initialized())
244 return 0;
245
246 rcu_read_lock();
247 policy = rcu_dereference(selinux_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 and which base permissions are covered.
586 */
587void services_compute_xperms_drivers(
588 struct extended_perms *xperms,
589 struct avtab_node *node)
590{
591 unsigned int i;
592
593 switch (node->datum.u.xperms->specified) {
594 case AVTAB_XPERMS_IOCTLDRIVER:
595 xperms->base_perms |= AVC_EXT_IOCTL;
596 /* if one or more driver has all permissions allowed */
597 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
598 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
599 break;
600 case AVTAB_XPERMS_IOCTLFUNCTION:
601 xperms->base_perms |= AVC_EXT_IOCTL;
602 /* if allowing permissions within a driver */
603 security_xperm_set(xperms->drivers.p,
604 node->datum.u.xperms->driver);
605 break;
606 case AVTAB_XPERMS_NLMSG:
607 xperms->base_perms |= AVC_EXT_NLMSG;
608 /* if allowing permissions within a driver */
609 security_xperm_set(xperms->drivers.p,
610 node->datum.u.xperms->driver);
611 break;
612 }
613
614 xperms->len = 1;
615}
616
617/*
618 * Compute access vectors and extended permissions based on a context
619 * structure pair for the permissions in a particular class.
620 */
621static void context_struct_compute_av(struct policydb *policydb,
622 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, 0, sizeof(*xperms));
642 }
643
644 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
645 pr_warn_ratelimited("SELinux: Invalid class %u\n", tclass);
646 return;
647 }
648
649 tclass_datum = policydb->class_val_to_struct[tclass - 1];
650
651 /*
652 * If a specific type enforcement rule was defined for
653 * this permission check, then use it.
654 */
655 avkey.target_class = tclass;
656 avkey.specified = AVTAB_AV | AVTAB_XPERMS;
657 sattr = &policydb->type_attr_map_array[scontext->type - 1];
658 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
659 ebitmap_for_each_positive_bit(sattr, snode, i) {
660 ebitmap_for_each_positive_bit(tattr, tnode, j) {
661 avkey.source_type = i + 1;
662 avkey.target_type = j + 1;
663 for (node = avtab_search_node(&policydb->te_avtab,
664 &avkey);
665 node;
666 node = avtab_search_node_next(node, avkey.specified)) {
667 if (node->key.specified == AVTAB_ALLOWED)
668 avd->allowed |= node->datum.u.data;
669 else if (node->key.specified == AVTAB_AUDITALLOW)
670 avd->auditallow |= node->datum.u.data;
671 else if (node->key.specified == AVTAB_AUDITDENY)
672 avd->auditdeny &= node->datum.u.data;
673 else if (xperms && (node->key.specified & AVTAB_XPERMS))
674 services_compute_xperms_drivers(xperms, node);
675 }
676
677 /* Check conditional av table for additional permissions */
678 cond_compute_av(&policydb->te_cond_avtab, &avkey,
679 avd, xperms);
680
681 }
682 }
683
684 /*
685 * Remove any permissions prohibited by a constraint (this includes
686 * the MLS policy).
687 */
688 constraint = tclass_datum->constraints;
689 while (constraint) {
690 if ((constraint->permissions & (avd->allowed)) &&
691 !constraint_expr_eval(policydb, scontext, tcontext, NULL,
692 constraint->expr)) {
693 avd->allowed &= ~(constraint->permissions);
694 }
695 constraint = constraint->next;
696 }
697
698 /*
699 * If checking process transition permission and the
700 * role is changing, then check the (current_role, new_role)
701 * pair.
702 */
703 if (tclass == policydb->process_class &&
704 (avd->allowed & policydb->process_trans_perms) &&
705 scontext->role != tcontext->role) {
706 for (ra = policydb->role_allow; ra; ra = ra->next) {
707 if (scontext->role == ra->role &&
708 tcontext->role == ra->new_role)
709 break;
710 }
711 if (!ra)
712 avd->allowed &= ~policydb->process_trans_perms;
713 }
714
715 /*
716 * If the given source and target types have boundary
717 * constraint, lazy checks have to mask any violated
718 * permission and notice it to userspace via audit.
719 */
720 type_attribute_bounds_av(policydb, scontext, tcontext,
721 tclass, avd);
722}
723
724static int security_validtrans_handle_fail(struct selinux_policy *policy,
725 struct sidtab_entry *oentry,
726 struct sidtab_entry *nentry,
727 struct sidtab_entry *tentry,
728 u16 tclass)
729{
730 struct policydb *p = &policy->policydb;
731 struct sidtab *sidtab = policy->sidtab;
732 char *o = NULL, *n = NULL, *t = NULL;
733 u32 olen, nlen, tlen;
734
735 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
736 goto out;
737 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
738 goto out;
739 if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
740 goto out;
741 audit_log(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(p, SYM_CLASSES, tclass-1));
745out:
746 kfree(o);
747 kfree(n);
748 kfree(t);
749
750 if (!enforcing_enabled())
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 selinux_policy *policy;
759 struct policydb *policydb;
760 struct sidtab *sidtab;
761 struct sidtab_entry *oentry;
762 struct sidtab_entry *nentry;
763 struct sidtab_entry *tentry;
764 struct class_datum *tclass_datum;
765 struct constraint_node *constraint;
766 u16 tclass;
767 int rc = 0;
768
769
770 if (!selinux_initialized())
771 return 0;
772
773 rcu_read_lock();
774
775 policy = rcu_dereference(selinux_state.policy);
776 policydb = &policy->policydb;
777 sidtab = policy->sidtab;
778
779 if (!user)
780 tclass = unmap_class(&policy->map, orig_tclass);
781 else
782 tclass = orig_tclass;
783
784 if (!tclass || tclass > policydb->p_classes.nprim) {
785 rc = -EINVAL;
786 goto out;
787 }
788 tclass_datum = policydb->class_val_to_struct[tclass - 1];
789
790 oentry = sidtab_search_entry(sidtab, oldsid);
791 if (!oentry) {
792 pr_err("SELinux: %s: unrecognized SID %d\n",
793 __func__, oldsid);
794 rc = -EINVAL;
795 goto out;
796 }
797
798 nentry = sidtab_search_entry(sidtab, newsid);
799 if (!nentry) {
800 pr_err("SELinux: %s: unrecognized SID %d\n",
801 __func__, newsid);
802 rc = -EINVAL;
803 goto out;
804 }
805
806 tentry = sidtab_search_entry(sidtab, tasksid);
807 if (!tentry) {
808 pr_err("SELinux: %s: unrecognized SID %d\n",
809 __func__, tasksid);
810 rc = -EINVAL;
811 goto out;
812 }
813
814 constraint = tclass_datum->validatetrans;
815 while (constraint) {
816 if (!constraint_expr_eval(policydb, &oentry->context,
817 &nentry->context, &tentry->context,
818 constraint->expr)) {
819 if (user)
820 rc = -EPERM;
821 else
822 rc = security_validtrans_handle_fail(policy,
823 oentry,
824 nentry,
825 tentry,
826 tclass);
827 goto out;
828 }
829 constraint = constraint->next;
830 }
831
832out:
833 rcu_read_unlock();
834 return rc;
835}
836
837int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
838 u16 tclass)
839{
840 return security_compute_validatetrans(oldsid, newsid, tasksid,
841 tclass, true);
842}
843
844int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
845 u16 orig_tclass)
846{
847 return security_compute_validatetrans(oldsid, newsid, tasksid,
848 orig_tclass, false);
849}
850
851/*
852 * security_bounded_transition - check whether the given
853 * transition is directed to bounded, or not.
854 * It returns 0, if @newsid is bounded by @oldsid.
855 * Otherwise, it returns error code.
856 *
857 * @oldsid : current security identifier
858 * @newsid : destinated security identifier
859 */
860int security_bounded_transition(u32 old_sid, u32 new_sid)
861{
862 struct selinux_policy *policy;
863 struct policydb *policydb;
864 struct sidtab *sidtab;
865 struct sidtab_entry *old_entry, *new_entry;
866 struct type_datum *type;
867 u32 index;
868 int rc;
869
870 if (!selinux_initialized())
871 return 0;
872
873 rcu_read_lock();
874 policy = rcu_dereference(selinux_state.policy);
875 policydb = &policy->policydb;
876 sidtab = policy->sidtab;
877
878 rc = -EINVAL;
879 old_entry = sidtab_search_entry(sidtab, old_sid);
880 if (!old_entry) {
881 pr_err("SELinux: %s: unrecognized SID %u\n",
882 __func__, old_sid);
883 goto out;
884 }
885
886 rc = -EINVAL;
887 new_entry = sidtab_search_entry(sidtab, new_sid);
888 if (!new_entry) {
889 pr_err("SELinux: %s: unrecognized SID %u\n",
890 __func__, new_sid);
891 goto out;
892 }
893
894 rc = 0;
895 /* type/domain unchanged */
896 if (old_entry->context.type == new_entry->context.type)
897 goto out;
898
899 index = new_entry->context.type;
900 while (true) {
901 type = policydb->type_val_to_struct[index - 1];
902 BUG_ON(!type);
903
904 /* not bounded anymore */
905 rc = -EPERM;
906 if (!type->bounds)
907 break;
908
909 /* @newsid is bounded by @oldsid */
910 rc = 0;
911 if (type->bounds == old_entry->context.type)
912 break;
913
914 index = type->bounds;
915 }
916
917 if (rc) {
918 char *old_name = NULL;
919 char *new_name = NULL;
920 u32 length;
921
922 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
923 &old_name, &length) &&
924 !sidtab_entry_to_string(policydb, sidtab, new_entry,
925 &new_name, &length)) {
926 audit_log(audit_context(),
927 GFP_ATOMIC, AUDIT_SELINUX_ERR,
928 "op=security_bounded_transition "
929 "seresult=denied "
930 "oldcontext=%s newcontext=%s",
931 old_name, new_name);
932 }
933 kfree(new_name);
934 kfree(old_name);
935 }
936out:
937 rcu_read_unlock();
938
939 return rc;
940}
941
942static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
943{
944 avd->allowed = 0;
945 avd->auditallow = 0;
946 avd->auditdeny = 0xffffffff;
947 if (policy)
948 avd->seqno = policy->latest_granting;
949 else
950 avd->seqno = 0;
951 avd->flags = 0;
952}
953
954static void update_xperms_extended_data(u8 specified,
955 struct extended_perms_data *from,
956 struct extended_perms_data *xp_data)
957{
958 unsigned int i;
959
960 switch (specified) {
961 case AVTAB_XPERMS_IOCTLDRIVER:
962 memset(xp_data->p, 0xff, sizeof(xp_data->p));
963 break;
964 case AVTAB_XPERMS_IOCTLFUNCTION:
965 case AVTAB_XPERMS_NLMSG:
966 for (i = 0; i < ARRAY_SIZE(xp_data->p); i++)
967 xp_data->p[i] |= from->p[i];
968 break;
969 }
970
971}
972
973void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
974 struct avtab_node *node)
975{
976 switch (node->datum.u.xperms->specified) {
977 case AVTAB_XPERMS_IOCTLFUNCTION:
978 if (xpermd->base_perm != AVC_EXT_IOCTL ||
979 xpermd->driver != node->datum.u.xperms->driver)
980 return;
981 break;
982 case AVTAB_XPERMS_IOCTLDRIVER:
983 if (xpermd->base_perm != AVC_EXT_IOCTL ||
984 !security_xperm_test(node->datum.u.xperms->perms.p,
985 xpermd->driver))
986 return;
987 break;
988 case AVTAB_XPERMS_NLMSG:
989 if (xpermd->base_perm != AVC_EXT_NLMSG ||
990 xpermd->driver != node->datum.u.xperms->driver)
991 return;
992 break;
993 default:
994 pr_warn_once(
995 "SELinux: unknown extended permission (%u) will be ignored\n",
996 node->datum.u.xperms->specified);
997 return;
998 }
999
1000 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
1001 xpermd->used |= XPERMS_ALLOWED;
1002 update_xperms_extended_data(node->datum.u.xperms->specified,
1003 &node->datum.u.xperms->perms,
1004 xpermd->allowed);
1005 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
1006 xpermd->used |= XPERMS_AUDITALLOW;
1007 update_xperms_extended_data(node->datum.u.xperms->specified,
1008 &node->datum.u.xperms->perms,
1009 xpermd->auditallow);
1010 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
1011 xpermd->used |= XPERMS_DONTAUDIT;
1012 update_xperms_extended_data(node->datum.u.xperms->specified,
1013 &node->datum.u.xperms->perms,
1014 xpermd->dontaudit);
1015 } else {
1016 pr_warn_once("SELinux: unknown specified key (%u)\n",
1017 node->key.specified);
1018 }
1019}
1020
1021void security_compute_xperms_decision(u32 ssid,
1022 u32 tsid,
1023 u16 orig_tclass,
1024 u8 driver,
1025 u8 base_perm,
1026 struct extended_perms_decision *xpermd)
1027{
1028 struct selinux_policy *policy;
1029 struct policydb *policydb;
1030 struct sidtab *sidtab;
1031 u16 tclass;
1032 struct context *scontext, *tcontext;
1033 struct avtab_key avkey;
1034 struct avtab_node *node;
1035 struct ebitmap *sattr, *tattr;
1036 struct ebitmap_node *snode, *tnode;
1037 unsigned int i, j;
1038
1039 xpermd->base_perm = base_perm;
1040 xpermd->driver = driver;
1041 xpermd->used = 0;
1042 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1043 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1044 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1045
1046 rcu_read_lock();
1047 if (!selinux_initialized())
1048 goto allow;
1049
1050 policy = rcu_dereference(selinux_state.policy);
1051 policydb = &policy->policydb;
1052 sidtab = policy->sidtab;
1053
1054 scontext = sidtab_search(sidtab, ssid);
1055 if (!scontext) {
1056 pr_err("SELinux: %s: unrecognized SID %d\n",
1057 __func__, ssid);
1058 goto out;
1059 }
1060
1061 tcontext = sidtab_search(sidtab, tsid);
1062 if (!tcontext) {
1063 pr_err("SELinux: %s: unrecognized SID %d\n",
1064 __func__, tsid);
1065 goto out;
1066 }
1067
1068 tclass = unmap_class(&policy->map, orig_tclass);
1069 if (unlikely(orig_tclass && !tclass)) {
1070 if (policydb->allow_unknown)
1071 goto allow;
1072 goto out;
1073 }
1074
1075
1076 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1077 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1078 goto out;
1079 }
1080
1081 avkey.target_class = tclass;
1082 avkey.specified = AVTAB_XPERMS;
1083 sattr = &policydb->type_attr_map_array[scontext->type - 1];
1084 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1085 ebitmap_for_each_positive_bit(sattr, snode, i) {
1086 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1087 avkey.source_type = i + 1;
1088 avkey.target_type = j + 1;
1089 for (node = avtab_search_node(&policydb->te_avtab,
1090 &avkey);
1091 node;
1092 node = avtab_search_node_next(node, avkey.specified))
1093 services_compute_xperms_decision(xpermd, node);
1094
1095 cond_compute_xperms(&policydb->te_cond_avtab,
1096 &avkey, xpermd);
1097 }
1098 }
1099out:
1100 rcu_read_unlock();
1101 return;
1102allow:
1103 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1104 goto out;
1105}
1106
1107/**
1108 * security_compute_av - Compute access vector decisions.
1109 * @ssid: source security identifier
1110 * @tsid: target security identifier
1111 * @orig_tclass: target security class
1112 * @avd: access vector decisions
1113 * @xperms: extended permissions
1114 *
1115 * Compute a set of access vector decisions based on the
1116 * SID pair (@ssid, @tsid) for the permissions in @tclass.
1117 */
1118void security_compute_av(u32 ssid,
1119 u32 tsid,
1120 u16 orig_tclass,
1121 struct av_decision *avd,
1122 struct extended_perms *xperms)
1123{
1124 struct selinux_policy *policy;
1125 struct policydb *policydb;
1126 struct sidtab *sidtab;
1127 u16 tclass;
1128 struct context *scontext = NULL, *tcontext = NULL;
1129
1130 rcu_read_lock();
1131 policy = rcu_dereference(selinux_state.policy);
1132 avd_init(policy, avd);
1133 xperms->len = 0;
1134 if (!selinux_initialized())
1135 goto allow;
1136
1137 policydb = &policy->policydb;
1138 sidtab = policy->sidtab;
1139
1140 scontext = sidtab_search(sidtab, ssid);
1141 if (!scontext) {
1142 pr_err("SELinux: %s: unrecognized SID %d\n",
1143 __func__, ssid);
1144 goto out;
1145 }
1146
1147 /* permissive domain? */
1148 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1149 avd->flags |= AVD_FLAGS_PERMISSIVE;
1150
1151 tcontext = sidtab_search(sidtab, tsid);
1152 if (!tcontext) {
1153 pr_err("SELinux: %s: unrecognized SID %d\n",
1154 __func__, tsid);
1155 goto out;
1156 }
1157
1158 tclass = unmap_class(&policy->map, orig_tclass);
1159 if (unlikely(orig_tclass && !tclass)) {
1160 if (policydb->allow_unknown)
1161 goto allow;
1162 goto out;
1163 }
1164 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1165 xperms);
1166 map_decision(&policy->map, orig_tclass, avd,
1167 policydb->allow_unknown);
1168out:
1169 rcu_read_unlock();
1170 return;
1171allow:
1172 avd->allowed = 0xffffffff;
1173 goto out;
1174}
1175
1176void security_compute_av_user(u32 ssid,
1177 u32 tsid,
1178 u16 tclass,
1179 struct av_decision *avd)
1180{
1181 struct selinux_policy *policy;
1182 struct policydb *policydb;
1183 struct sidtab *sidtab;
1184 struct context *scontext = NULL, *tcontext = NULL;
1185
1186 rcu_read_lock();
1187 policy = rcu_dereference(selinux_state.policy);
1188 avd_init(policy, avd);
1189 if (!selinux_initialized())
1190 goto allow;
1191
1192 policydb = &policy->policydb;
1193 sidtab = policy->sidtab;
1194
1195 scontext = sidtab_search(sidtab, ssid);
1196 if (!scontext) {
1197 pr_err("SELinux: %s: unrecognized SID %d\n",
1198 __func__, ssid);
1199 goto out;
1200 }
1201
1202 /* permissive domain? */
1203 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1204 avd->flags |= AVD_FLAGS_PERMISSIVE;
1205
1206 tcontext = sidtab_search(sidtab, tsid);
1207 if (!tcontext) {
1208 pr_err("SELinux: %s: unrecognized SID %d\n",
1209 __func__, tsid);
1210 goto out;
1211 }
1212
1213 if (unlikely(!tclass)) {
1214 if (policydb->allow_unknown)
1215 goto allow;
1216 goto out;
1217 }
1218
1219 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1220 NULL);
1221 out:
1222 rcu_read_unlock();
1223 return;
1224allow:
1225 avd->allowed = 0xffffffff;
1226 goto out;
1227}
1228
1229/*
1230 * Write the security context string representation of
1231 * the context structure `context' into a dynamically
1232 * allocated string of the correct size. Set `*scontext'
1233 * to point to this string and set `*scontext_len' to
1234 * the length of the string.
1235 */
1236static int context_struct_to_string(struct policydb *p,
1237 struct context *context,
1238 char **scontext, u32 *scontext_len)
1239{
1240 char *scontextp;
1241
1242 if (scontext)
1243 *scontext = NULL;
1244 *scontext_len = 0;
1245
1246 if (context->len) {
1247 *scontext_len = context->len;
1248 if (scontext) {
1249 *scontext = kstrdup(context->str, GFP_ATOMIC);
1250 if (!(*scontext))
1251 return -ENOMEM;
1252 }
1253 return 0;
1254 }
1255
1256 /* Compute the size of the context. */
1257 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1258 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1259 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1260 *scontext_len += mls_compute_context_len(p, context);
1261
1262 if (!scontext)
1263 return 0;
1264
1265 /* Allocate space for the context; caller must free this space. */
1266 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1267 if (!scontextp)
1268 return -ENOMEM;
1269 *scontext = scontextp;
1270
1271 /*
1272 * Copy the user name, role name and type name into the context.
1273 */
1274 scontextp += sprintf(scontextp, "%s:%s:%s",
1275 sym_name(p, SYM_USERS, context->user - 1),
1276 sym_name(p, SYM_ROLES, context->role - 1),
1277 sym_name(p, SYM_TYPES, context->type - 1));
1278
1279 mls_sid_to_context(p, context, &scontextp);
1280
1281 *scontextp = 0;
1282
1283 return 0;
1284}
1285
1286static int sidtab_entry_to_string(struct policydb *p,
1287 struct sidtab *sidtab,
1288 struct sidtab_entry *entry,
1289 char **scontext, u32 *scontext_len)
1290{
1291 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1292
1293 if (rc != -ENOENT)
1294 return rc;
1295
1296 rc = context_struct_to_string(p, &entry->context, scontext,
1297 scontext_len);
1298 if (!rc && scontext)
1299 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1300 return rc;
1301}
1302
1303#include "initial_sid_to_string.h"
1304
1305int security_sidtab_hash_stats(char *page)
1306{
1307 struct selinux_policy *policy;
1308 int rc;
1309
1310 if (!selinux_initialized()) {
1311 pr_err("SELinux: %s: called before initial load_policy\n",
1312 __func__);
1313 return -EINVAL;
1314 }
1315
1316 rcu_read_lock();
1317 policy = rcu_dereference(selinux_state.policy);
1318 rc = sidtab_hash_stats(policy->sidtab, page);
1319 rcu_read_unlock();
1320
1321 return rc;
1322}
1323
1324const char *security_get_initial_sid_context(u32 sid)
1325{
1326 if (unlikely(sid > SECINITSID_NUM))
1327 return NULL;
1328 return initial_sid_to_string[sid];
1329}
1330
1331static int security_sid_to_context_core(u32 sid, char **scontext,
1332 u32 *scontext_len, int force,
1333 int only_invalid)
1334{
1335 struct selinux_policy *policy;
1336 struct policydb *policydb;
1337 struct sidtab *sidtab;
1338 struct sidtab_entry *entry;
1339 int rc = 0;
1340
1341 if (scontext)
1342 *scontext = NULL;
1343 *scontext_len = 0;
1344
1345 if (!selinux_initialized()) {
1346 if (sid <= SECINITSID_NUM) {
1347 char *scontextp;
1348 const char *s;
1349
1350 /*
1351 * Before the policy is loaded, translate
1352 * SECINITSID_INIT to "kernel", because systemd and
1353 * libselinux < 2.6 take a getcon_raw() result that is
1354 * both non-null and not "kernel" to mean that a policy
1355 * is already loaded.
1356 */
1357 if (sid == SECINITSID_INIT)
1358 sid = SECINITSID_KERNEL;
1359
1360 s = initial_sid_to_string[sid];
1361 if (!s)
1362 return -EINVAL;
1363 *scontext_len = strlen(s) + 1;
1364 if (!scontext)
1365 return 0;
1366 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1367 if (!scontextp)
1368 return -ENOMEM;
1369 *scontext = scontextp;
1370 return 0;
1371 }
1372 pr_err("SELinux: %s: called before initial "
1373 "load_policy on unknown SID %d\n", __func__, sid);
1374 return -EINVAL;
1375 }
1376 rcu_read_lock();
1377 policy = rcu_dereference(selinux_state.policy);
1378 policydb = &policy->policydb;
1379 sidtab = policy->sidtab;
1380
1381 if (force)
1382 entry = sidtab_search_entry_force(sidtab, sid);
1383 else
1384 entry = sidtab_search_entry(sidtab, sid);
1385 if (!entry) {
1386 pr_err("SELinux: %s: unrecognized SID %d\n",
1387 __func__, sid);
1388 rc = -EINVAL;
1389 goto out_unlock;
1390 }
1391 if (only_invalid && !entry->context.len)
1392 goto out_unlock;
1393
1394 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1395 scontext_len);
1396
1397out_unlock:
1398 rcu_read_unlock();
1399 return rc;
1400
1401}
1402
1403/**
1404 * security_sid_to_context - Obtain a context for a given SID.
1405 * @sid: security identifier, SID
1406 * @scontext: security context
1407 * @scontext_len: length in bytes
1408 *
1409 * Write the string representation of the context associated with @sid
1410 * into a dynamically allocated string of the correct size. Set @scontext
1411 * to point to this string and set @scontext_len to the length of the string.
1412 */
1413int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1414{
1415 return security_sid_to_context_core(sid, scontext,
1416 scontext_len, 0, 0);
1417}
1418
1419int security_sid_to_context_force(u32 sid,
1420 char **scontext, u32 *scontext_len)
1421{
1422 return security_sid_to_context_core(sid, scontext,
1423 scontext_len, 1, 0);
1424}
1425
1426/**
1427 * security_sid_to_context_inval - Obtain a context for a given SID if it
1428 * is invalid.
1429 * @sid: security identifier, SID
1430 * @scontext: security context
1431 * @scontext_len: length in bytes
1432 *
1433 * Write the string representation of the context associated with @sid
1434 * into a dynamically allocated string of the correct size, but only if the
1435 * context is invalid in the current policy. Set @scontext to point to
1436 * this string (or NULL if the context is valid) and set @scontext_len to
1437 * the length of the string (or 0 if the context is valid).
1438 */
1439int security_sid_to_context_inval(u32 sid,
1440 char **scontext, u32 *scontext_len)
1441{
1442 return security_sid_to_context_core(sid, scontext,
1443 scontext_len, 1, 1);
1444}
1445
1446/*
1447 * Caveat: Mutates scontext.
1448 */
1449static int string_to_context_struct(struct policydb *pol,
1450 struct sidtab *sidtabp,
1451 char *scontext,
1452 struct context *ctx,
1453 u32 def_sid)
1454{
1455 struct role_datum *role;
1456 struct type_datum *typdatum;
1457 struct user_datum *usrdatum;
1458 char *scontextp, *p, oldc;
1459 int rc = 0;
1460
1461 context_init(ctx);
1462
1463 /* Parse the security context. */
1464
1465 rc = -EINVAL;
1466 scontextp = scontext;
1467
1468 /* Extract the user. */
1469 p = scontextp;
1470 while (*p && *p != ':')
1471 p++;
1472
1473 if (*p == 0)
1474 goto out;
1475
1476 *p++ = 0;
1477
1478 usrdatum = symtab_search(&pol->p_users, scontextp);
1479 if (!usrdatum)
1480 goto out;
1481
1482 ctx->user = usrdatum->value;
1483
1484 /* Extract role. */
1485 scontextp = p;
1486 while (*p && *p != ':')
1487 p++;
1488
1489 if (*p == 0)
1490 goto out;
1491
1492 *p++ = 0;
1493
1494 role = symtab_search(&pol->p_roles, scontextp);
1495 if (!role)
1496 goto out;
1497 ctx->role = role->value;
1498
1499 /* Extract type. */
1500 scontextp = p;
1501 while (*p && *p != ':')
1502 p++;
1503 oldc = *p;
1504 *p++ = 0;
1505
1506 typdatum = symtab_search(&pol->p_types, scontextp);
1507 if (!typdatum || typdatum->attribute)
1508 goto out;
1509
1510 ctx->type = typdatum->value;
1511
1512 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1513 if (rc)
1514 goto out;
1515
1516 /* Check the validity of the new context. */
1517 rc = -EINVAL;
1518 if (!policydb_context_isvalid(pol, ctx))
1519 goto out;
1520 rc = 0;
1521out:
1522 if (rc)
1523 context_destroy(ctx);
1524 return rc;
1525}
1526
1527static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1528 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1529 int force)
1530{
1531 struct selinux_policy *policy;
1532 struct policydb *policydb;
1533 struct sidtab *sidtab;
1534 char *scontext2, *str = NULL;
1535 struct context context;
1536 int rc = 0;
1537
1538 /* An empty security context is never valid. */
1539 if (!scontext_len)
1540 return -EINVAL;
1541
1542 /* Copy the string to allow changes and ensure a NUL terminator */
1543 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1544 if (!scontext2)
1545 return -ENOMEM;
1546
1547 if (!selinux_initialized()) {
1548 u32 i;
1549
1550 for (i = 1; i < SECINITSID_NUM; i++) {
1551 const char *s = initial_sid_to_string[i];
1552
1553 if (s && !strcmp(s, scontext2)) {
1554 *sid = i;
1555 goto out;
1556 }
1557 }
1558 *sid = SECINITSID_KERNEL;
1559 goto out;
1560 }
1561 *sid = SECSID_NULL;
1562
1563 if (force) {
1564 /* Save another copy for storing in uninterpreted form */
1565 rc = -ENOMEM;
1566 str = kstrdup(scontext2, gfp_flags);
1567 if (!str)
1568 goto out;
1569 }
1570retry:
1571 rcu_read_lock();
1572 policy = rcu_dereference(selinux_state.policy);
1573 policydb = &policy->policydb;
1574 sidtab = policy->sidtab;
1575 rc = string_to_context_struct(policydb, sidtab, scontext2,
1576 &context, def_sid);
1577 if (rc == -EINVAL && force) {
1578 context.str = str;
1579 context.len = strlen(str) + 1;
1580 str = NULL;
1581 } else if (rc)
1582 goto out_unlock;
1583 rc = sidtab_context_to_sid(sidtab, &context, sid);
1584 if (rc == -ESTALE) {
1585 rcu_read_unlock();
1586 if (context.str) {
1587 str = context.str;
1588 context.str = NULL;
1589 }
1590 context_destroy(&context);
1591 goto retry;
1592 }
1593 context_destroy(&context);
1594out_unlock:
1595 rcu_read_unlock();
1596out:
1597 kfree(scontext2);
1598 kfree(str);
1599 return rc;
1600}
1601
1602/**
1603 * security_context_to_sid - Obtain a SID for a given security context.
1604 * @scontext: security context
1605 * @scontext_len: length in bytes
1606 * @sid: security identifier, SID
1607 * @gfp: context for the allocation
1608 *
1609 * Obtains a SID associated with the security context that
1610 * has the string representation specified by @scontext.
1611 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1612 * memory is available, or 0 on success.
1613 */
1614int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1615 gfp_t gfp)
1616{
1617 return security_context_to_sid_core(scontext, scontext_len,
1618 sid, SECSID_NULL, gfp, 0);
1619}
1620
1621int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1622{
1623 return security_context_to_sid(scontext, strlen(scontext),
1624 sid, gfp);
1625}
1626
1627/**
1628 * security_context_to_sid_default - Obtain a SID for a given security context,
1629 * falling back to specified default if needed.
1630 *
1631 * @scontext: security context
1632 * @scontext_len: length in bytes
1633 * @sid: security identifier, SID
1634 * @def_sid: default SID to assign on error
1635 * @gfp_flags: the allocator get-free-page (GFP) flags
1636 *
1637 * Obtains a SID associated with the security context that
1638 * has the string representation specified by @scontext.
1639 * The default SID is passed to the MLS layer to be used to allow
1640 * kernel labeling of the MLS field if the MLS field is not present
1641 * (for upgrading to MLS without full relabel).
1642 * Implicitly forces adding of the context even if it cannot be mapped yet.
1643 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1644 * memory is available, or 0 on success.
1645 */
1646int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1647 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1648{
1649 return security_context_to_sid_core(scontext, scontext_len,
1650 sid, def_sid, gfp_flags, 1);
1651}
1652
1653int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1654 u32 *sid)
1655{
1656 return security_context_to_sid_core(scontext, scontext_len,
1657 sid, SECSID_NULL, GFP_KERNEL, 1);
1658}
1659
1660static int compute_sid_handle_invalid_context(
1661 struct selinux_policy *policy,
1662 struct sidtab_entry *sentry,
1663 struct sidtab_entry *tentry,
1664 u16 tclass,
1665 struct context *newcontext)
1666{
1667 struct policydb *policydb = &policy->policydb;
1668 struct sidtab *sidtab = policy->sidtab;
1669 char *s = NULL, *t = NULL, *n = NULL;
1670 u32 slen, tlen, nlen;
1671 struct audit_buffer *ab;
1672
1673 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1674 goto out;
1675 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1676 goto out;
1677 if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1678 goto out;
1679 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1680 if (!ab)
1681 goto out;
1682 audit_log_format(ab,
1683 "op=security_compute_sid invalid_context=");
1684 /* no need to record the NUL with untrusted strings */
1685 audit_log_n_untrustedstring(ab, n, nlen - 1);
1686 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1687 s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1688 audit_log_end(ab);
1689out:
1690 kfree(s);
1691 kfree(t);
1692 kfree(n);
1693 if (!enforcing_enabled())
1694 return 0;
1695 return -EACCES;
1696}
1697
1698static void filename_compute_type(struct policydb *policydb,
1699 struct context *newcontext,
1700 u32 stype, u32 ttype, u16 tclass,
1701 const char *objname)
1702{
1703 struct filename_trans_key ft;
1704 struct filename_trans_datum *datum;
1705
1706 /*
1707 * Most filename trans rules are going to live in specific directories
1708 * like /dev or /var/run. This bitmap will quickly skip rule searches
1709 * if the ttype does not contain any rules.
1710 */
1711 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1712 return;
1713
1714 ft.ttype = ttype;
1715 ft.tclass = tclass;
1716 ft.name = objname;
1717
1718 datum = policydb_filenametr_search(policydb, &ft);
1719 while (datum) {
1720 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1721 newcontext->type = datum->otype;
1722 return;
1723 }
1724 datum = datum->next;
1725 }
1726}
1727
1728static int security_compute_sid(u32 ssid,
1729 u32 tsid,
1730 u16 orig_tclass,
1731 u16 specified,
1732 const char *objname,
1733 u32 *out_sid,
1734 bool kern)
1735{
1736 struct selinux_policy *policy;
1737 struct policydb *policydb;
1738 struct sidtab *sidtab;
1739 struct class_datum *cladatum;
1740 struct context *scontext, *tcontext, newcontext;
1741 struct sidtab_entry *sentry, *tentry;
1742 struct avtab_key avkey;
1743 struct avtab_node *avnode, *node;
1744 u16 tclass;
1745 int rc = 0;
1746 bool sock;
1747
1748 if (!selinux_initialized()) {
1749 switch (orig_tclass) {
1750 case SECCLASS_PROCESS: /* kernel value */
1751 *out_sid = ssid;
1752 break;
1753 default:
1754 *out_sid = tsid;
1755 break;
1756 }
1757 goto out;
1758 }
1759
1760retry:
1761 cladatum = NULL;
1762 context_init(&newcontext);
1763
1764 rcu_read_lock();
1765
1766 policy = rcu_dereference(selinux_state.policy);
1767
1768 if (kern) {
1769 tclass = unmap_class(&policy->map, orig_tclass);
1770 sock = security_is_socket_class(orig_tclass);
1771 } else {
1772 tclass = orig_tclass;
1773 sock = security_is_socket_class(map_class(&policy->map,
1774 tclass));
1775 }
1776
1777 policydb = &policy->policydb;
1778 sidtab = policy->sidtab;
1779
1780 sentry = sidtab_search_entry(sidtab, ssid);
1781 if (!sentry) {
1782 pr_err("SELinux: %s: unrecognized SID %d\n",
1783 __func__, ssid);
1784 rc = -EINVAL;
1785 goto out_unlock;
1786 }
1787 tentry = sidtab_search_entry(sidtab, tsid);
1788 if (!tentry) {
1789 pr_err("SELinux: %s: unrecognized SID %d\n",
1790 __func__, tsid);
1791 rc = -EINVAL;
1792 goto out_unlock;
1793 }
1794
1795 scontext = &sentry->context;
1796 tcontext = &tentry->context;
1797
1798 if (tclass && tclass <= policydb->p_classes.nprim)
1799 cladatum = policydb->class_val_to_struct[tclass - 1];
1800
1801 /* Set the user identity. */
1802 switch (specified) {
1803 case AVTAB_TRANSITION:
1804 case AVTAB_CHANGE:
1805 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1806 newcontext.user = tcontext->user;
1807 } else {
1808 /* notice this gets both DEFAULT_SOURCE and unset */
1809 /* Use the process user identity. */
1810 newcontext.user = scontext->user;
1811 }
1812 break;
1813 case AVTAB_MEMBER:
1814 /* Use the related object owner. */
1815 newcontext.user = tcontext->user;
1816 break;
1817 }
1818
1819 /* Set the role to default values. */
1820 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1821 newcontext.role = scontext->role;
1822 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1823 newcontext.role = tcontext->role;
1824 } else {
1825 if ((tclass == policydb->process_class) || sock)
1826 newcontext.role = scontext->role;
1827 else
1828 newcontext.role = OBJECT_R_VAL;
1829 }
1830
1831 /* Set the type.
1832 * Look for a type transition/member/change rule.
1833 */
1834 avkey.source_type = scontext->type;
1835 avkey.target_type = tcontext->type;
1836 avkey.target_class = tclass;
1837 avkey.specified = specified;
1838 avnode = avtab_search_node(&policydb->te_avtab, &avkey);
1839
1840 /* If no permanent rule, also check for enabled conditional rules */
1841 if (!avnode) {
1842 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1843 for (; node; node = avtab_search_node_next(node, specified)) {
1844 if (node->key.specified & AVTAB_ENABLED) {
1845 avnode = node;
1846 break;
1847 }
1848 }
1849 }
1850
1851 /* If a permanent rule is found, use the type from
1852 * the type transition/member/change rule. Otherwise,
1853 * set the type to its default values.
1854 */
1855 if (avnode) {
1856 newcontext.type = avnode->datum.u.data;
1857 } else if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1858 newcontext.type = scontext->type;
1859 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1860 newcontext.type = tcontext->type;
1861 } else {
1862 if ((tclass == policydb->process_class) || sock) {
1863 /* Use the type of process. */
1864 newcontext.type = scontext->type;
1865 } else {
1866 /* Use the type of the related object. */
1867 newcontext.type = tcontext->type;
1868 }
1869 }
1870
1871 /* if we have a objname this is a file trans check so check those rules */
1872 if (objname)
1873 filename_compute_type(policydb, &newcontext, scontext->type,
1874 tcontext->type, tclass, objname);
1875
1876 /* Check for class-specific changes. */
1877 if (specified & AVTAB_TRANSITION) {
1878 /* Look for a role transition rule. */
1879 struct role_trans_datum *rtd;
1880 struct role_trans_key rtk = {
1881 .role = scontext->role,
1882 .type = tcontext->type,
1883 .tclass = tclass,
1884 };
1885
1886 rtd = policydb_roletr_search(policydb, &rtk);
1887 if (rtd)
1888 newcontext.role = rtd->new_role;
1889 }
1890
1891 /* Set the MLS attributes.
1892 This is done last because it may allocate memory. */
1893 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1894 &newcontext, sock);
1895 if (rc)
1896 goto out_unlock;
1897
1898 /* Check the validity of the context. */
1899 if (!policydb_context_isvalid(policydb, &newcontext)) {
1900 rc = compute_sid_handle_invalid_context(policy, sentry,
1901 tentry, tclass,
1902 &newcontext);
1903 if (rc)
1904 goto out_unlock;
1905 }
1906 /* Obtain the sid for the context. */
1907 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1908 if (rc == -ESTALE) {
1909 rcu_read_unlock();
1910 context_destroy(&newcontext);
1911 goto retry;
1912 }
1913out_unlock:
1914 rcu_read_unlock();
1915 context_destroy(&newcontext);
1916out:
1917 return rc;
1918}
1919
1920/**
1921 * security_transition_sid - Compute the SID for a new subject/object.
1922 * @ssid: source security identifier
1923 * @tsid: target security identifier
1924 * @tclass: target security class
1925 * @qstr: object name
1926 * @out_sid: security identifier for new subject/object
1927 *
1928 * Compute a SID to use for labeling a new subject or object in the
1929 * class @tclass based on a SID pair (@ssid, @tsid).
1930 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1931 * if insufficient memory is available, or %0 if the new SID was
1932 * computed successfully.
1933 */
1934int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1935 const struct qstr *qstr, u32 *out_sid)
1936{
1937 return security_compute_sid(ssid, tsid, tclass,
1938 AVTAB_TRANSITION,
1939 qstr ? qstr->name : NULL, out_sid, true);
1940}
1941
1942int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1943 const char *objname, u32 *out_sid)
1944{
1945 return security_compute_sid(ssid, tsid, tclass,
1946 AVTAB_TRANSITION,
1947 objname, out_sid, false);
1948}
1949
1950/**
1951 * security_member_sid - Compute the SID for member selection.
1952 * @ssid: source security identifier
1953 * @tsid: target security identifier
1954 * @tclass: target security class
1955 * @out_sid: security identifier for selected member
1956 *
1957 * Compute a SID to use when selecting a member of a polyinstantiated
1958 * object of class @tclass based on a SID pair (@ssid, @tsid).
1959 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1960 * if insufficient memory is available, or %0 if the SID was
1961 * computed successfully.
1962 */
1963int security_member_sid(u32 ssid,
1964 u32 tsid,
1965 u16 tclass,
1966 u32 *out_sid)
1967{
1968 return security_compute_sid(ssid, tsid, tclass,
1969 AVTAB_MEMBER, NULL,
1970 out_sid, false);
1971}
1972
1973/**
1974 * security_change_sid - Compute the SID for object relabeling.
1975 * @ssid: source security identifier
1976 * @tsid: target security identifier
1977 * @tclass: target security class
1978 * @out_sid: security identifier for selected member
1979 *
1980 * Compute a SID to use for relabeling an object of class @tclass
1981 * based on a SID pair (@ssid, @tsid).
1982 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1983 * if insufficient memory is available, or %0 if the SID was
1984 * computed successfully.
1985 */
1986int security_change_sid(u32 ssid,
1987 u32 tsid,
1988 u16 tclass,
1989 u32 *out_sid)
1990{
1991 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1992 out_sid, false);
1993}
1994
1995static inline int convert_context_handle_invalid_context(
1996 struct policydb *policydb,
1997 struct context *context)
1998{
1999 char *s;
2000 u32 len;
2001
2002 if (enforcing_enabled())
2003 return -EINVAL;
2004
2005 if (!context_struct_to_string(policydb, context, &s, &len)) {
2006 pr_warn("SELinux: Context %s would be invalid if enforcing\n",
2007 s);
2008 kfree(s);
2009 }
2010 return 0;
2011}
2012
2013/**
2014 * services_convert_context - Convert a security context across policies.
2015 * @args: populated convert_context_args struct
2016 * @oldc: original context
2017 * @newc: converted context
2018 * @gfp_flags: allocation flags
2019 *
2020 * Convert the values in the security context structure @oldc from the values
2021 * specified in the policy @args->oldp to the values specified in the policy
2022 * @args->newp, storing the new context in @newc, and verifying that the
2023 * context is valid under the new policy.
2024 */
2025int services_convert_context(struct convert_context_args *args,
2026 struct context *oldc, struct context *newc,
2027 gfp_t gfp_flags)
2028{
2029 struct ocontext *oc;
2030 struct role_datum *role;
2031 struct type_datum *typdatum;
2032 struct user_datum *usrdatum;
2033 char *s;
2034 u32 len;
2035 int rc;
2036
2037 if (oldc->str) {
2038 s = kstrdup(oldc->str, gfp_flags);
2039 if (!s)
2040 return -ENOMEM;
2041
2042 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL);
2043 if (rc == -EINVAL) {
2044 /*
2045 * Retain string representation for later mapping.
2046 *
2047 * IMPORTANT: We need to copy the contents of oldc->str
2048 * back into s again because string_to_context_struct()
2049 * may have garbled it.
2050 */
2051 memcpy(s, oldc->str, oldc->len);
2052 context_init(newc);
2053 newc->str = s;
2054 newc->len = oldc->len;
2055 return 0;
2056 }
2057 kfree(s);
2058 if (rc) {
2059 /* Other error condition, e.g. ENOMEM. */
2060 pr_err("SELinux: Unable to map context %s, rc = %d.\n",
2061 oldc->str, -rc);
2062 return rc;
2063 }
2064 pr_info("SELinux: Context %s became valid (mapped).\n",
2065 oldc->str);
2066 return 0;
2067 }
2068
2069 context_init(newc);
2070
2071 /* Convert the user. */
2072 usrdatum = symtab_search(&args->newp->p_users,
2073 sym_name(args->oldp, SYM_USERS, oldc->user - 1));
2074 if (!usrdatum)
2075 goto bad;
2076 newc->user = usrdatum->value;
2077
2078 /* Convert the role. */
2079 role = symtab_search(&args->newp->p_roles,
2080 sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2081 if (!role)
2082 goto bad;
2083 newc->role = role->value;
2084
2085 /* Convert the type. */
2086 typdatum = symtab_search(&args->newp->p_types,
2087 sym_name(args->oldp, SYM_TYPES, oldc->type - 1));
2088 if (!typdatum)
2089 goto bad;
2090 newc->type = typdatum->value;
2091
2092 /* Convert the MLS fields if dealing with MLS policies */
2093 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2094 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2095 if (rc)
2096 goto bad;
2097 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2098 /*
2099 * Switching between non-MLS and MLS policy:
2100 * ensure that the MLS fields of the context for all
2101 * existing entries in the sidtab are filled in with a
2102 * suitable default value, likely taken from one of the
2103 * initial SIDs.
2104 */
2105 oc = args->newp->ocontexts[OCON_ISID];
2106 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2107 oc = oc->next;
2108 if (!oc) {
2109 pr_err("SELinux: unable to look up"
2110 " the initial SIDs list\n");
2111 goto bad;
2112 }
2113 rc = mls_range_set(newc, &oc->context[0].range);
2114 if (rc)
2115 goto bad;
2116 }
2117
2118 /* Check the validity of the new context. */
2119 if (!policydb_context_isvalid(args->newp, newc)) {
2120 rc = convert_context_handle_invalid_context(args->oldp, oldc);
2121 if (rc)
2122 goto bad;
2123 }
2124
2125 return 0;
2126bad:
2127 /* Map old representation to string and save it. */
2128 rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2129 if (rc)
2130 return rc;
2131 context_destroy(newc);
2132 newc->str = s;
2133 newc->len = len;
2134 pr_info("SELinux: Context %s became invalid (unmapped).\n",
2135 newc->str);
2136 return 0;
2137}
2138
2139static void security_load_policycaps(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(selinux_state.policycap); i++)
2148 WRITE_ONCE(selinux_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_load_state *load_state)
2185{
2186 struct selinux_state *state = &selinux_state;
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(u32 seqno)
2198{
2199 /* Flush external caches and notify userspace of policy load */
2200 avc_ss_reset(seqno);
2201 selnl_notify_policyload(seqno);
2202 selinux_status_update_policyload(seqno);
2203 selinux_netlbl_cache_invalidate();
2204 selinux_xfrm_notify_policyload();
2205 selinux_ima_measure_state_locked();
2206}
2207
2208void selinux_policy_commit(struct selinux_load_state *load_state)
2209{
2210 struct selinux_state *state = &selinux_state;
2211 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
2212 unsigned long flags;
2213 u32 seqno;
2214
2215 oldpolicy = rcu_dereference_protected(state->policy,
2216 lockdep_is_held(&state->policy_mutex));
2217
2218 /* If switching between different policy types, log MLS status */
2219 if (oldpolicy) {
2220 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
2221 pr_info("SELinux: Disabling MLS support...\n");
2222 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
2223 pr_info("SELinux: Enabling MLS support...\n");
2224 }
2225
2226 /* Set latest granting seqno for new policy. */
2227 if (oldpolicy)
2228 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
2229 else
2230 newpolicy->latest_granting = 1;
2231 seqno = newpolicy->latest_granting;
2232
2233 /* Install the new policy. */
2234 if (oldpolicy) {
2235 sidtab_freeze_begin(oldpolicy->sidtab, &flags);
2236 rcu_assign_pointer(state->policy, newpolicy);
2237 sidtab_freeze_end(oldpolicy->sidtab, &flags);
2238 } else {
2239 rcu_assign_pointer(state->policy, newpolicy);
2240 }
2241
2242 /* Load the policycaps from the new policy */
2243 security_load_policycaps(newpolicy);
2244
2245 if (!selinux_initialized()) {
2246 /*
2247 * After first policy load, the security server is
2248 * marked as initialized and ready to handle requests and
2249 * any objects created prior to policy load are then labeled.
2250 */
2251 selinux_mark_initialized();
2252 selinux_complete_init();
2253 }
2254
2255 /* Free the old policy */
2256 synchronize_rcu();
2257 selinux_policy_free(oldpolicy);
2258 kfree(load_state->convert_data);
2259
2260 /* Notify others of the policy change */
2261 selinux_notify_policy_change(seqno);
2262}
2263
2264/**
2265 * security_load_policy - Load a security policy configuration.
2266 * @data: binary policy data
2267 * @len: length of data in bytes
2268 * @load_state: policy load state
2269 *
2270 * Load a new set of security policy configuration data,
2271 * validate it and convert the SID table as necessary.
2272 * This function will flush the access vector cache after
2273 * loading the new policy.
2274 */
2275int security_load_policy(void *data, size_t len,
2276 struct selinux_load_state *load_state)
2277{
2278 struct selinux_state *state = &selinux_state;
2279 struct selinux_policy *newpolicy, *oldpolicy;
2280 struct selinux_policy_convert_data *convert_data;
2281 int rc = 0;
2282 struct policy_file file = { data, len }, *fp = &file;
2283
2284 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2285 if (!newpolicy)
2286 return -ENOMEM;
2287
2288 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2289 if (!newpolicy->sidtab) {
2290 rc = -ENOMEM;
2291 goto err_policy;
2292 }
2293
2294 rc = policydb_read(&newpolicy->policydb, fp);
2295 if (rc)
2296 goto err_sidtab;
2297
2298 newpolicy->policydb.len = len;
2299 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2300 &newpolicy->map);
2301 if (rc)
2302 goto err_policydb;
2303
2304 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2305 if (rc) {
2306 pr_err("SELinux: unable to load the initial SIDs\n");
2307 goto err_mapping;
2308 }
2309
2310 if (!selinux_initialized()) {
2311 /* First policy load, so no need to preserve state from old policy */
2312 load_state->policy = newpolicy;
2313 load_state->convert_data = NULL;
2314 return 0;
2315 }
2316
2317 oldpolicy = rcu_dereference_protected(state->policy,
2318 lockdep_is_held(&state->policy_mutex));
2319
2320 /* Preserve active boolean values from the old policy */
2321 rc = security_preserve_bools(oldpolicy, newpolicy);
2322 if (rc) {
2323 pr_err("SELinux: unable to preserve booleans\n");
2324 goto err_free_isids;
2325 }
2326
2327 /*
2328 * Convert the internal representations of contexts
2329 * in the new SID table.
2330 */
2331
2332 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2333 if (!convert_data) {
2334 rc = -ENOMEM;
2335 goto err_free_isids;
2336 }
2337
2338 convert_data->args.oldp = &oldpolicy->policydb;
2339 convert_data->args.newp = &newpolicy->policydb;
2340
2341 convert_data->sidtab_params.args = &convert_data->args;
2342 convert_data->sidtab_params.target = newpolicy->sidtab;
2343
2344 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2345 if (rc) {
2346 pr_err("SELinux: unable to convert the internal"
2347 " representation of contexts in the new SID"
2348 " table\n");
2349 goto err_free_convert_data;
2350 }
2351
2352 load_state->policy = newpolicy;
2353 load_state->convert_data = convert_data;
2354 return 0;
2355
2356err_free_convert_data:
2357 kfree(convert_data);
2358err_free_isids:
2359 sidtab_destroy(newpolicy->sidtab);
2360err_mapping:
2361 kfree(newpolicy->map.mapping);
2362err_policydb:
2363 policydb_destroy(&newpolicy->policydb);
2364err_sidtab:
2365 kfree(newpolicy->sidtab);
2366err_policy:
2367 kfree(newpolicy);
2368
2369 return rc;
2370}
2371
2372/**
2373 * ocontext_to_sid - Helper to safely get sid for an ocontext
2374 * @sidtab: SID table
2375 * @c: ocontext structure
2376 * @index: index of the context entry (0 or 1)
2377 * @out_sid: pointer to the resulting SID value
2378 *
2379 * For all ocontexts except OCON_ISID the SID fields are populated
2380 * on-demand when needed. Since updating the SID value is an SMP-sensitive
2381 * operation, this helper must be used to do that safely.
2382 *
2383 * WARNING: This function may return -ESTALE, indicating that the caller
2384 * must retry the operation after re-acquiring the policy pointer!
2385 */
2386static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
2387 size_t index, u32 *out_sid)
2388{
2389 int rc;
2390 u32 sid;
2391
2392 /* Ensure the associated sidtab entry is visible to this thread. */
2393 sid = smp_load_acquire(&c->sid[index]);
2394 if (!sid) {
2395 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
2396 if (rc)
2397 return rc;
2398
2399 /*
2400 * Ensure the new sidtab entry is visible to other threads
2401 * when they see the SID.
2402 */
2403 smp_store_release(&c->sid[index], sid);
2404 }
2405 *out_sid = sid;
2406 return 0;
2407}
2408
2409/**
2410 * security_port_sid - Obtain the SID for a port.
2411 * @protocol: protocol number
2412 * @port: port number
2413 * @out_sid: security identifier
2414 */
2415int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2416{
2417 struct selinux_policy *policy;
2418 struct policydb *policydb;
2419 struct sidtab *sidtab;
2420 struct ocontext *c;
2421 int rc;
2422
2423 if (!selinux_initialized()) {
2424 *out_sid = SECINITSID_PORT;
2425 return 0;
2426 }
2427
2428retry:
2429 rc = 0;
2430 rcu_read_lock();
2431 policy = rcu_dereference(selinux_state.policy);
2432 policydb = &policy->policydb;
2433 sidtab = policy->sidtab;
2434
2435 c = policydb->ocontexts[OCON_PORT];
2436 while (c) {
2437 if (c->u.port.protocol == protocol &&
2438 c->u.port.low_port <= port &&
2439 c->u.port.high_port >= port)
2440 break;
2441 c = c->next;
2442 }
2443
2444 if (c) {
2445 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2446 if (rc == -ESTALE) {
2447 rcu_read_unlock();
2448 goto retry;
2449 }
2450 if (rc)
2451 goto out;
2452 } else {
2453 *out_sid = SECINITSID_PORT;
2454 }
2455
2456out:
2457 rcu_read_unlock();
2458 return rc;
2459}
2460
2461/**
2462 * security_ib_pkey_sid - Obtain the SID for a pkey.
2463 * @subnet_prefix: Subnet Prefix
2464 * @pkey_num: pkey number
2465 * @out_sid: security identifier
2466 */
2467int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2468{
2469 struct selinux_policy *policy;
2470 struct policydb *policydb;
2471 struct sidtab *sidtab;
2472 struct ocontext *c;
2473 int rc;
2474
2475 if (!selinux_initialized()) {
2476 *out_sid = SECINITSID_UNLABELED;
2477 return 0;
2478 }
2479
2480retry:
2481 rc = 0;
2482 rcu_read_lock();
2483 policy = rcu_dereference(selinux_state.policy);
2484 policydb = &policy->policydb;
2485 sidtab = policy->sidtab;
2486
2487 c = policydb->ocontexts[OCON_IBPKEY];
2488 while (c) {
2489 if (c->u.ibpkey.low_pkey <= pkey_num &&
2490 c->u.ibpkey.high_pkey >= pkey_num &&
2491 c->u.ibpkey.subnet_prefix == subnet_prefix)
2492 break;
2493
2494 c = c->next;
2495 }
2496
2497 if (c) {
2498 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2499 if (rc == -ESTALE) {
2500 rcu_read_unlock();
2501 goto retry;
2502 }
2503 if (rc)
2504 goto out;
2505 } else
2506 *out_sid = SECINITSID_UNLABELED;
2507
2508out:
2509 rcu_read_unlock();
2510 return rc;
2511}
2512
2513/**
2514 * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2515 * @dev_name: device name
2516 * @port_num: port number
2517 * @out_sid: security identifier
2518 */
2519int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid)
2520{
2521 struct selinux_policy *policy;
2522 struct policydb *policydb;
2523 struct sidtab *sidtab;
2524 struct ocontext *c;
2525 int rc;
2526
2527 if (!selinux_initialized()) {
2528 *out_sid = SECINITSID_UNLABELED;
2529 return 0;
2530 }
2531
2532retry:
2533 rc = 0;
2534 rcu_read_lock();
2535 policy = rcu_dereference(selinux_state.policy);
2536 policydb = &policy->policydb;
2537 sidtab = policy->sidtab;
2538
2539 c = policydb->ocontexts[OCON_IBENDPORT];
2540 while (c) {
2541 if (c->u.ibendport.port == port_num &&
2542 !strncmp(c->u.ibendport.dev_name,
2543 dev_name,
2544 IB_DEVICE_NAME_MAX))
2545 break;
2546
2547 c = c->next;
2548 }
2549
2550 if (c) {
2551 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2552 if (rc == -ESTALE) {
2553 rcu_read_unlock();
2554 goto retry;
2555 }
2556 if (rc)
2557 goto out;
2558 } else
2559 *out_sid = SECINITSID_UNLABELED;
2560
2561out:
2562 rcu_read_unlock();
2563 return rc;
2564}
2565
2566/**
2567 * security_netif_sid - Obtain the SID for a network interface.
2568 * @name: interface name
2569 * @if_sid: interface SID
2570 */
2571int security_netif_sid(char *name, u32 *if_sid)
2572{
2573 struct selinux_policy *policy;
2574 struct policydb *policydb;
2575 struct sidtab *sidtab;
2576 int rc;
2577 struct ocontext *c;
2578
2579 if (!selinux_initialized()) {
2580 *if_sid = SECINITSID_NETIF;
2581 return 0;
2582 }
2583
2584retry:
2585 rc = 0;
2586 rcu_read_lock();
2587 policy = rcu_dereference(selinux_state.policy);
2588 policydb = &policy->policydb;
2589 sidtab = policy->sidtab;
2590
2591 c = policydb->ocontexts[OCON_NETIF];
2592 while (c) {
2593 if (strcmp(name, c->u.name) == 0)
2594 break;
2595 c = c->next;
2596 }
2597
2598 if (c) {
2599 rc = ocontext_to_sid(sidtab, c, 0, if_sid);
2600 if (rc == -ESTALE) {
2601 rcu_read_unlock();
2602 goto retry;
2603 }
2604 if (rc)
2605 goto out;
2606 } else
2607 *if_sid = SECINITSID_NETIF;
2608
2609out:
2610 rcu_read_unlock();
2611 return rc;
2612}
2613
2614static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2615{
2616 int i, fail = 0;
2617
2618 for (i = 0; i < 4; i++)
2619 if (addr[i] != (input[i] & mask[i])) {
2620 fail = 1;
2621 break;
2622 }
2623
2624 return !fail;
2625}
2626
2627/**
2628 * security_node_sid - Obtain the SID for a node (host).
2629 * @domain: communication domain aka address family
2630 * @addrp: address
2631 * @addrlen: address length in bytes
2632 * @out_sid: security identifier
2633 */
2634int security_node_sid(u16 domain,
2635 void *addrp,
2636 u32 addrlen,
2637 u32 *out_sid)
2638{
2639 struct selinux_policy *policy;
2640 struct policydb *policydb;
2641 struct sidtab *sidtab;
2642 int rc;
2643 struct ocontext *c;
2644
2645 if (!selinux_initialized()) {
2646 *out_sid = SECINITSID_NODE;
2647 return 0;
2648 }
2649
2650retry:
2651 rcu_read_lock();
2652 policy = rcu_dereference(selinux_state.policy);
2653 policydb = &policy->policydb;
2654 sidtab = policy->sidtab;
2655
2656 switch (domain) {
2657 case AF_INET: {
2658 u32 addr;
2659
2660 rc = -EINVAL;
2661 if (addrlen != sizeof(u32))
2662 goto out;
2663
2664 addr = *((u32 *)addrp);
2665
2666 c = policydb->ocontexts[OCON_NODE];
2667 while (c) {
2668 if (c->u.node.addr == (addr & c->u.node.mask))
2669 break;
2670 c = c->next;
2671 }
2672 break;
2673 }
2674
2675 case AF_INET6:
2676 rc = -EINVAL;
2677 if (addrlen != sizeof(u64) * 2)
2678 goto out;
2679 c = policydb->ocontexts[OCON_NODE6];
2680 while (c) {
2681 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2682 c->u.node6.mask))
2683 break;
2684 c = c->next;
2685 }
2686 break;
2687
2688 default:
2689 rc = 0;
2690 *out_sid = SECINITSID_NODE;
2691 goto out;
2692 }
2693
2694 if (c) {
2695 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2696 if (rc == -ESTALE) {
2697 rcu_read_unlock();
2698 goto retry;
2699 }
2700 if (rc)
2701 goto out;
2702 } else {
2703 *out_sid = SECINITSID_NODE;
2704 }
2705
2706 rc = 0;
2707out:
2708 rcu_read_unlock();
2709 return rc;
2710}
2711
2712#define SIDS_NEL 25
2713
2714/**
2715 * security_get_user_sids - Obtain reachable SIDs for a user.
2716 * @fromsid: starting SID
2717 * @username: username
2718 * @sids: array of reachable SIDs for user
2719 * @nel: number of elements in @sids
2720 *
2721 * Generate the set of SIDs for legal security contexts
2722 * for a given user that can be reached by @fromsid.
2723 * Set *@sids to point to a dynamically allocated
2724 * array containing the set of SIDs. Set *@nel to the
2725 * number of elements in the array.
2726 */
2727
2728int security_get_user_sids(u32 fromsid,
2729 char *username,
2730 u32 **sids,
2731 u32 *nel)
2732{
2733 struct selinux_policy *policy;
2734 struct policydb *policydb;
2735 struct sidtab *sidtab;
2736 struct context *fromcon, usercon;
2737 u32 *mysids = NULL, *mysids2, sid;
2738 u32 i, j, mynel, maxnel = SIDS_NEL;
2739 struct user_datum *user;
2740 struct role_datum *role;
2741 struct ebitmap_node *rnode, *tnode;
2742 int rc;
2743
2744 *sids = NULL;
2745 *nel = 0;
2746
2747 if (!selinux_initialized())
2748 return 0;
2749
2750 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2751 if (!mysids)
2752 return -ENOMEM;
2753
2754retry:
2755 mynel = 0;
2756 rcu_read_lock();
2757 policy = rcu_dereference(selinux_state.policy);
2758 policydb = &policy->policydb;
2759 sidtab = policy->sidtab;
2760
2761 context_init(&usercon);
2762
2763 rc = -EINVAL;
2764 fromcon = sidtab_search(sidtab, fromsid);
2765 if (!fromcon)
2766 goto out_unlock;
2767
2768 rc = -EINVAL;
2769 user = symtab_search(&policydb->p_users, username);
2770 if (!user)
2771 goto out_unlock;
2772
2773 usercon.user = user->value;
2774
2775 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2776 role = policydb->role_val_to_struct[i];
2777 usercon.role = i + 1;
2778 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2779 usercon.type = j + 1;
2780
2781 if (mls_setup_user_range(policydb, fromcon, user,
2782 &usercon))
2783 continue;
2784
2785 rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2786 if (rc == -ESTALE) {
2787 rcu_read_unlock();
2788 goto retry;
2789 }
2790 if (rc)
2791 goto out_unlock;
2792 if (mynel < maxnel) {
2793 mysids[mynel++] = sid;
2794 } else {
2795 rc = -ENOMEM;
2796 maxnel += SIDS_NEL;
2797 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2798 if (!mysids2)
2799 goto out_unlock;
2800 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2801 kfree(mysids);
2802 mysids = mysids2;
2803 mysids[mynel++] = sid;
2804 }
2805 }
2806 }
2807 rc = 0;
2808out_unlock:
2809 rcu_read_unlock();
2810 if (rc || !mynel) {
2811 kfree(mysids);
2812 return rc;
2813 }
2814
2815 rc = -ENOMEM;
2816 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2817 if (!mysids2) {
2818 kfree(mysids);
2819 return rc;
2820 }
2821 for (i = 0, j = 0; i < mynel; i++) {
2822 struct av_decision dummy_avd;
2823 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2824 SECCLASS_PROCESS, /* kernel value */
2825 PROCESS__TRANSITION, AVC_STRICT,
2826 &dummy_avd);
2827 if (!rc)
2828 mysids2[j++] = mysids[i];
2829 cond_resched();
2830 }
2831 kfree(mysids);
2832 *sids = mysids2;
2833 *nel = j;
2834 return 0;
2835}
2836
2837/**
2838 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2839 * @policy: policy
2840 * @fstype: filesystem type
2841 * @path: path from root of mount
2842 * @orig_sclass: file security class
2843 * @sid: SID for path
2844 *
2845 * Obtain a SID to use for a file in a filesystem that
2846 * cannot support xattr or use a fixed labeling behavior like
2847 * transition SIDs or task SIDs.
2848 *
2849 * WARNING: This function may return -ESTALE, indicating that the caller
2850 * must retry the operation after re-acquiring the policy pointer!
2851 */
2852static inline int __security_genfs_sid(struct selinux_policy *policy,
2853 const char *fstype,
2854 const char *path,
2855 u16 orig_sclass,
2856 u32 *sid)
2857{
2858 struct policydb *policydb = &policy->policydb;
2859 struct sidtab *sidtab = policy->sidtab;
2860 u16 sclass;
2861 struct genfs *genfs;
2862 struct ocontext *c;
2863 int cmp = 0;
2864
2865 while (path[0] == '/' && path[1] == '/')
2866 path++;
2867
2868 sclass = unmap_class(&policy->map, orig_sclass);
2869 *sid = SECINITSID_UNLABELED;
2870
2871 for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2872 cmp = strcmp(fstype, genfs->fstype);
2873 if (cmp <= 0)
2874 break;
2875 }
2876
2877 if (!genfs || cmp)
2878 return -ENOENT;
2879
2880 for (c = genfs->head; c; c = c->next) {
2881 size_t len = strlen(c->u.name);
2882 if ((!c->v.sclass || sclass == c->v.sclass) &&
2883 (strncmp(c->u.name, path, len) == 0))
2884 break;
2885 }
2886
2887 if (!c)
2888 return -ENOENT;
2889
2890 return ocontext_to_sid(sidtab, c, 0, sid);
2891}
2892
2893/**
2894 * security_genfs_sid - Obtain a SID for a file in a filesystem
2895 * @fstype: filesystem type
2896 * @path: path from root of mount
2897 * @orig_sclass: file security class
2898 * @sid: SID for path
2899 *
2900 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2901 * it afterward.
2902 */
2903int security_genfs_sid(const char *fstype,
2904 const char *path,
2905 u16 orig_sclass,
2906 u32 *sid)
2907{
2908 struct selinux_policy *policy;
2909 int retval;
2910
2911 if (!selinux_initialized()) {
2912 *sid = SECINITSID_UNLABELED;
2913 return 0;
2914 }
2915
2916 do {
2917 rcu_read_lock();
2918 policy = rcu_dereference(selinux_state.policy);
2919 retval = __security_genfs_sid(policy, fstype, path,
2920 orig_sclass, sid);
2921 rcu_read_unlock();
2922 } while (retval == -ESTALE);
2923 return retval;
2924}
2925
2926int selinux_policy_genfs_sid(struct selinux_policy *policy,
2927 const char *fstype,
2928 const char *path,
2929 u16 orig_sclass,
2930 u32 *sid)
2931{
2932 /* no lock required, policy is not yet accessible by other threads */
2933 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2934}
2935
2936/**
2937 * security_fs_use - Determine how to handle labeling for a filesystem.
2938 * @sb: superblock in question
2939 */
2940int security_fs_use(struct super_block *sb)
2941{
2942 struct selinux_policy *policy;
2943 struct policydb *policydb;
2944 struct sidtab *sidtab;
2945 int rc;
2946 struct ocontext *c;
2947 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2948 const char *fstype = sb->s_type->name;
2949
2950 if (!selinux_initialized()) {
2951 sbsec->behavior = SECURITY_FS_USE_NONE;
2952 sbsec->sid = SECINITSID_UNLABELED;
2953 return 0;
2954 }
2955
2956retry:
2957 rcu_read_lock();
2958 policy = rcu_dereference(selinux_state.policy);
2959 policydb = &policy->policydb;
2960 sidtab = policy->sidtab;
2961
2962 c = policydb->ocontexts[OCON_FSUSE];
2963 while (c) {
2964 if (strcmp(fstype, c->u.name) == 0)
2965 break;
2966 c = c->next;
2967 }
2968
2969 if (c) {
2970 sbsec->behavior = c->v.behavior;
2971 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
2972 if (rc == -ESTALE) {
2973 rcu_read_unlock();
2974 goto retry;
2975 }
2976 if (rc)
2977 goto out;
2978 } else {
2979 rc = __security_genfs_sid(policy, fstype, "/",
2980 SECCLASS_DIR, &sbsec->sid);
2981 if (rc == -ESTALE) {
2982 rcu_read_unlock();
2983 goto retry;
2984 }
2985 if (rc) {
2986 sbsec->behavior = SECURITY_FS_USE_NONE;
2987 rc = 0;
2988 } else {
2989 sbsec->behavior = SECURITY_FS_USE_GENFS;
2990 }
2991 }
2992
2993out:
2994 rcu_read_unlock();
2995 return rc;
2996}
2997
2998int security_get_bools(struct selinux_policy *policy,
2999 u32 *len, char ***names, int **values)
3000{
3001 struct policydb *policydb;
3002 u32 i;
3003 int rc;
3004
3005 policydb = &policy->policydb;
3006
3007 *names = NULL;
3008 *values = NULL;
3009
3010 rc = 0;
3011 *len = policydb->p_bools.nprim;
3012 if (!*len)
3013 goto out;
3014
3015 rc = -ENOMEM;
3016 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
3017 if (!*names)
3018 goto err;
3019
3020 rc = -ENOMEM;
3021 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
3022 if (!*values)
3023 goto err;
3024
3025 for (i = 0; i < *len; i++) {
3026 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3027
3028 rc = -ENOMEM;
3029 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3030 GFP_ATOMIC);
3031 if (!(*names)[i])
3032 goto err;
3033 }
3034 rc = 0;
3035out:
3036 return rc;
3037err:
3038 if (*names) {
3039 for (i = 0; i < *len; i++)
3040 kfree((*names)[i]);
3041 kfree(*names);
3042 }
3043 kfree(*values);
3044 *len = 0;
3045 *names = NULL;
3046 *values = NULL;
3047 goto out;
3048}
3049
3050
3051int security_set_bools(u32 len, int *values)
3052{
3053 struct selinux_state *state = &selinux_state;
3054 struct selinux_policy *newpolicy, *oldpolicy;
3055 int rc;
3056 u32 i, seqno = 0;
3057
3058 if (!selinux_initialized())
3059 return -EINVAL;
3060
3061 oldpolicy = rcu_dereference_protected(state->policy,
3062 lockdep_is_held(&state->policy_mutex));
3063
3064 /* Consistency check on number of booleans, should never fail */
3065 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3066 return -EINVAL;
3067
3068 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3069 if (!newpolicy)
3070 return -ENOMEM;
3071
3072 /*
3073 * Deep copy only the parts of the policydb that might be
3074 * modified as a result of changing booleans.
3075 */
3076 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3077 if (rc) {
3078 kfree(newpolicy);
3079 return -ENOMEM;
3080 }
3081
3082 /* Update the boolean states in the copy */
3083 for (i = 0; i < len; i++) {
3084 int new_state = !!values[i];
3085 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3086
3087 if (new_state != old_state) {
3088 audit_log(audit_context(), GFP_ATOMIC,
3089 AUDIT_MAC_CONFIG_CHANGE,
3090 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3091 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3092 new_state,
3093 old_state,
3094 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3095 audit_get_sessionid(current));
3096 newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3097 }
3098 }
3099
3100 /* Re-evaluate the conditional rules in the copy */
3101 evaluate_cond_nodes(&newpolicy->policydb);
3102
3103 /* Set latest granting seqno for new policy */
3104 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3105 seqno = newpolicy->latest_granting;
3106
3107 /* Install the new policy */
3108 rcu_assign_pointer(state->policy, newpolicy);
3109
3110 /*
3111 * Free the conditional portions of the old policydb
3112 * that were copied for the new policy, and the oldpolicy
3113 * structure itself but not what it references.
3114 */
3115 synchronize_rcu();
3116 selinux_policy_cond_free(oldpolicy);
3117
3118 /* Notify others of the policy change */
3119 selinux_notify_policy_change(seqno);
3120 return 0;
3121}
3122
3123int security_get_bool_value(u32 index)
3124{
3125 struct selinux_policy *policy;
3126 struct policydb *policydb;
3127 int rc;
3128 u32 len;
3129
3130 if (!selinux_initialized())
3131 return 0;
3132
3133 rcu_read_lock();
3134 policy = rcu_dereference(selinux_state.policy);
3135 policydb = &policy->policydb;
3136
3137 rc = -EFAULT;
3138 len = policydb->p_bools.nprim;
3139 if (index >= len)
3140 goto out;
3141
3142 rc = policydb->bool_val_to_struct[index]->state;
3143out:
3144 rcu_read_unlock();
3145 return rc;
3146}
3147
3148static int security_preserve_bools(struct selinux_policy *oldpolicy,
3149 struct selinux_policy *newpolicy)
3150{
3151 int rc, *bvalues = NULL;
3152 char **bnames = NULL;
3153 struct cond_bool_datum *booldatum;
3154 u32 i, nbools = 0;
3155
3156 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3157 if (rc)
3158 goto out;
3159 for (i = 0; i < nbools; i++) {
3160 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3161 bnames[i]);
3162 if (booldatum)
3163 booldatum->state = bvalues[i];
3164 }
3165 evaluate_cond_nodes(&newpolicy->policydb);
3166
3167out:
3168 if (bnames) {
3169 for (i = 0; i < nbools; i++)
3170 kfree(bnames[i]);
3171 }
3172 kfree(bnames);
3173 kfree(bvalues);
3174 return rc;
3175}
3176
3177/*
3178 * security_sid_mls_copy() - computes a new sid based on the given
3179 * sid and the mls portion of mls_sid.
3180 */
3181int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
3182{
3183 struct selinux_policy *policy;
3184 struct policydb *policydb;
3185 struct sidtab *sidtab;
3186 struct context *context1;
3187 struct context *context2;
3188 struct context newcon;
3189 char *s;
3190 u32 len;
3191 int rc;
3192
3193 if (!selinux_initialized()) {
3194 *new_sid = sid;
3195 return 0;
3196 }
3197
3198retry:
3199 rc = 0;
3200 context_init(&newcon);
3201
3202 rcu_read_lock();
3203 policy = rcu_dereference(selinux_state.policy);
3204 policydb = &policy->policydb;
3205 sidtab = policy->sidtab;
3206
3207 if (!policydb->mls_enabled) {
3208 *new_sid = sid;
3209 goto out_unlock;
3210 }
3211
3212 rc = -EINVAL;
3213 context1 = sidtab_search(sidtab, sid);
3214 if (!context1) {
3215 pr_err("SELinux: %s: unrecognized SID %d\n",
3216 __func__, sid);
3217 goto out_unlock;
3218 }
3219
3220 rc = -EINVAL;
3221 context2 = sidtab_search(sidtab, mls_sid);
3222 if (!context2) {
3223 pr_err("SELinux: %s: unrecognized SID %d\n",
3224 __func__, mls_sid);
3225 goto out_unlock;
3226 }
3227
3228 newcon.user = context1->user;
3229 newcon.role = context1->role;
3230 newcon.type = context1->type;
3231 rc = mls_context_cpy(&newcon, context2);
3232 if (rc)
3233 goto out_unlock;
3234
3235 /* Check the validity of the new context. */
3236 if (!policydb_context_isvalid(policydb, &newcon)) {
3237 rc = convert_context_handle_invalid_context(policydb,
3238 &newcon);
3239 if (rc) {
3240 if (!context_struct_to_string(policydb, &newcon, &s,
3241 &len)) {
3242 struct audit_buffer *ab;
3243
3244 ab = audit_log_start(audit_context(),
3245 GFP_ATOMIC,
3246 AUDIT_SELINUX_ERR);
3247 audit_log_format(ab,
3248 "op=security_sid_mls_copy invalid_context=");
3249 /* don't record NUL with untrusted strings */
3250 audit_log_n_untrustedstring(ab, s, len - 1);
3251 audit_log_end(ab);
3252 kfree(s);
3253 }
3254 goto out_unlock;
3255 }
3256 }
3257 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3258 if (rc == -ESTALE) {
3259 rcu_read_unlock();
3260 context_destroy(&newcon);
3261 goto retry;
3262 }
3263out_unlock:
3264 rcu_read_unlock();
3265 context_destroy(&newcon);
3266 return rc;
3267}
3268
3269/**
3270 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3271 * @nlbl_sid: NetLabel SID
3272 * @nlbl_type: NetLabel labeling protocol type
3273 * @xfrm_sid: XFRM SID
3274 * @peer_sid: network peer sid
3275 *
3276 * Description:
3277 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3278 * resolved into a single SID it is returned via @peer_sid and the function
3279 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
3280 * returns a negative value. A table summarizing the behavior is below:
3281 *
3282 * | function return | @sid
3283 * ------------------------------+-----------------+-----------------
3284 * no peer labels | 0 | SECSID_NULL
3285 * single peer label | 0 | <peer_label>
3286 * multiple, consistent labels | 0 | <peer_label>
3287 * multiple, inconsistent labels | -<errno> | SECSID_NULL
3288 *
3289 */
3290int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
3291 u32 xfrm_sid,
3292 u32 *peer_sid)
3293{
3294 struct selinux_policy *policy;
3295 struct policydb *policydb;
3296 struct sidtab *sidtab;
3297 int rc;
3298 struct context *nlbl_ctx;
3299 struct context *xfrm_ctx;
3300
3301 *peer_sid = SECSID_NULL;
3302
3303 /* handle the common (which also happens to be the set of easy) cases
3304 * right away, these two if statements catch everything involving a
3305 * single or absent peer SID/label */
3306 if (xfrm_sid == SECSID_NULL) {
3307 *peer_sid = nlbl_sid;
3308 return 0;
3309 }
3310 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3311 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3312 * is present */
3313 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3314 *peer_sid = xfrm_sid;
3315 return 0;
3316 }
3317
3318 if (!selinux_initialized())
3319 return 0;
3320
3321 rcu_read_lock();
3322 policy = rcu_dereference(selinux_state.policy);
3323 policydb = &policy->policydb;
3324 sidtab = policy->sidtab;
3325
3326 /*
3327 * We don't need to check initialized here since the only way both
3328 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3329 * security server was initialized and state->initialized was true.
3330 */
3331 if (!policydb->mls_enabled) {
3332 rc = 0;
3333 goto out;
3334 }
3335
3336 rc = -EINVAL;
3337 nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3338 if (!nlbl_ctx) {
3339 pr_err("SELinux: %s: unrecognized SID %d\n",
3340 __func__, nlbl_sid);
3341 goto out;
3342 }
3343 rc = -EINVAL;
3344 xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3345 if (!xfrm_ctx) {
3346 pr_err("SELinux: %s: unrecognized SID %d\n",
3347 __func__, xfrm_sid);
3348 goto out;
3349 }
3350 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3351 if (rc)
3352 goto out;
3353
3354 /* at present NetLabel SIDs/labels really only carry MLS
3355 * information so if the MLS portion of the NetLabel SID
3356 * matches the MLS portion of the labeled XFRM SID/label
3357 * then pass along the XFRM SID as it is the most
3358 * expressive */
3359 *peer_sid = xfrm_sid;
3360out:
3361 rcu_read_unlock();
3362 return rc;
3363}
3364
3365static int get_classes_callback(void *k, void *d, void *args)
3366{
3367 struct class_datum *datum = d;
3368 char *name = k, **classes = args;
3369 u32 value = datum->value - 1;
3370
3371 classes[value] = kstrdup(name, GFP_ATOMIC);
3372 if (!classes[value])
3373 return -ENOMEM;
3374
3375 return 0;
3376}
3377
3378int security_get_classes(struct selinux_policy *policy,
3379 char ***classes, u32 *nclasses)
3380{
3381 struct policydb *policydb;
3382 int rc;
3383
3384 policydb = &policy->policydb;
3385
3386 rc = -ENOMEM;
3387 *nclasses = policydb->p_classes.nprim;
3388 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3389 if (!*classes)
3390 goto out;
3391
3392 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3393 *classes);
3394 if (rc) {
3395 u32 i;
3396
3397 for (i = 0; i < *nclasses; i++)
3398 kfree((*classes)[i]);
3399 kfree(*classes);
3400 }
3401
3402out:
3403 return rc;
3404}
3405
3406static int get_permissions_callback(void *k, void *d, void *args)
3407{
3408 struct perm_datum *datum = d;
3409 char *name = k, **perms = args;
3410 u32 value = datum->value - 1;
3411
3412 perms[value] = kstrdup(name, GFP_ATOMIC);
3413 if (!perms[value])
3414 return -ENOMEM;
3415
3416 return 0;
3417}
3418
3419int security_get_permissions(struct selinux_policy *policy,
3420 const char *class, char ***perms, u32 *nperms)
3421{
3422 struct policydb *policydb;
3423 u32 i;
3424 int rc;
3425 struct class_datum *match;
3426
3427 policydb = &policy->policydb;
3428
3429 rc = -EINVAL;
3430 match = symtab_search(&policydb->p_classes, class);
3431 if (!match) {
3432 pr_err("SELinux: %s: unrecognized class %s\n",
3433 __func__, class);
3434 goto out;
3435 }
3436
3437 rc = -ENOMEM;
3438 *nperms = match->permissions.nprim;
3439 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3440 if (!*perms)
3441 goto out;
3442
3443 if (match->comdatum) {
3444 rc = hashtab_map(&match->comdatum->permissions.table,
3445 get_permissions_callback, *perms);
3446 if (rc)
3447 goto err;
3448 }
3449
3450 rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3451 *perms);
3452 if (rc)
3453 goto err;
3454
3455out:
3456 return rc;
3457
3458err:
3459 for (i = 0; i < *nperms; i++)
3460 kfree((*perms)[i]);
3461 kfree(*perms);
3462 return rc;
3463}
3464
3465int security_get_reject_unknown(void)
3466{
3467 struct selinux_policy *policy;
3468 int value;
3469
3470 if (!selinux_initialized())
3471 return 0;
3472
3473 rcu_read_lock();
3474 policy = rcu_dereference(selinux_state.policy);
3475 value = policy->policydb.reject_unknown;
3476 rcu_read_unlock();
3477 return value;
3478}
3479
3480int security_get_allow_unknown(void)
3481{
3482 struct selinux_policy *policy;
3483 int value;
3484
3485 if (!selinux_initialized())
3486 return 0;
3487
3488 rcu_read_lock();
3489 policy = rcu_dereference(selinux_state.policy);
3490 value = policy->policydb.allow_unknown;
3491 rcu_read_unlock();
3492 return value;
3493}
3494
3495/**
3496 * security_policycap_supported - Check for a specific policy capability
3497 * @req_cap: capability
3498 *
3499 * Description:
3500 * This function queries the currently loaded policy to see if it supports the
3501 * capability specified by @req_cap. Returns true (1) if the capability is
3502 * supported, false (0) if it isn't supported.
3503 *
3504 */
3505int security_policycap_supported(unsigned int req_cap)
3506{
3507 struct selinux_policy *policy;
3508 int rc;
3509
3510 if (!selinux_initialized())
3511 return 0;
3512
3513 rcu_read_lock();
3514 policy = rcu_dereference(selinux_state.policy);
3515 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3516 rcu_read_unlock();
3517
3518 return rc;
3519}
3520
3521struct selinux_audit_rule {
3522 u32 au_seqno;
3523 struct context au_ctxt;
3524};
3525
3526void selinux_audit_rule_free(void *vrule)
3527{
3528 struct selinux_audit_rule *rule = vrule;
3529
3530 if (rule) {
3531 context_destroy(&rule->au_ctxt);
3532 kfree(rule);
3533 }
3534}
3535
3536int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule,
3537 gfp_t gfp)
3538{
3539 struct selinux_state *state = &selinux_state;
3540 struct selinux_policy *policy;
3541 struct policydb *policydb;
3542 struct selinux_audit_rule *tmprule;
3543 struct role_datum *roledatum;
3544 struct type_datum *typedatum;
3545 struct user_datum *userdatum;
3546 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3547 int rc = 0;
3548
3549 *rule = NULL;
3550
3551 if (!selinux_initialized())
3552 return -EOPNOTSUPP;
3553
3554 switch (field) {
3555 case AUDIT_SUBJ_USER:
3556 case AUDIT_SUBJ_ROLE:
3557 case AUDIT_SUBJ_TYPE:
3558 case AUDIT_OBJ_USER:
3559 case AUDIT_OBJ_ROLE:
3560 case AUDIT_OBJ_TYPE:
3561 /* only 'equals' and 'not equals' fit user, role, and type */
3562 if (op != Audit_equal && op != Audit_not_equal)
3563 return -EINVAL;
3564 break;
3565 case AUDIT_SUBJ_SEN:
3566 case AUDIT_SUBJ_CLR:
3567 case AUDIT_OBJ_LEV_LOW:
3568 case AUDIT_OBJ_LEV_HIGH:
3569 /* we do not allow a range, indicated by the presence of '-' */
3570 if (strchr(rulestr, '-'))
3571 return -EINVAL;
3572 break;
3573 default:
3574 /* only the above fields are valid */
3575 return -EINVAL;
3576 }
3577
3578 tmprule = kzalloc(sizeof(struct selinux_audit_rule), gfp);
3579 if (!tmprule)
3580 return -ENOMEM;
3581 context_init(&tmprule->au_ctxt);
3582
3583 rcu_read_lock();
3584 policy = rcu_dereference(state->policy);
3585 policydb = &policy->policydb;
3586 tmprule->au_seqno = policy->latest_granting;
3587 switch (field) {
3588 case AUDIT_SUBJ_USER:
3589 case AUDIT_OBJ_USER:
3590 userdatum = symtab_search(&policydb->p_users, rulestr);
3591 if (!userdatum) {
3592 rc = -EINVAL;
3593 goto err;
3594 }
3595 tmprule->au_ctxt.user = userdatum->value;
3596 break;
3597 case AUDIT_SUBJ_ROLE:
3598 case AUDIT_OBJ_ROLE:
3599 roledatum = symtab_search(&policydb->p_roles, rulestr);
3600 if (!roledatum) {
3601 rc = -EINVAL;
3602 goto err;
3603 }
3604 tmprule->au_ctxt.role = roledatum->value;
3605 break;
3606 case AUDIT_SUBJ_TYPE:
3607 case AUDIT_OBJ_TYPE:
3608 typedatum = symtab_search(&policydb->p_types, rulestr);
3609 if (!typedatum) {
3610 rc = -EINVAL;
3611 goto err;
3612 }
3613 tmprule->au_ctxt.type = typedatum->value;
3614 break;
3615 case AUDIT_SUBJ_SEN:
3616 case AUDIT_SUBJ_CLR:
3617 case AUDIT_OBJ_LEV_LOW:
3618 case AUDIT_OBJ_LEV_HIGH:
3619 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3620 GFP_ATOMIC);
3621 if (rc)
3622 goto err;
3623 break;
3624 }
3625 rcu_read_unlock();
3626
3627 *rule = tmprule;
3628 return 0;
3629
3630err:
3631 rcu_read_unlock();
3632 selinux_audit_rule_free(tmprule);
3633 *rule = NULL;
3634 return rc;
3635}
3636
3637/* Check to see if the rule contains any selinux fields */
3638int selinux_audit_rule_known(struct audit_krule *rule)
3639{
3640 u32 i;
3641
3642 for (i = 0; i < rule->field_count; i++) {
3643 struct audit_field *f = &rule->fields[i];
3644 switch (f->type) {
3645 case AUDIT_SUBJ_USER:
3646 case AUDIT_SUBJ_ROLE:
3647 case AUDIT_SUBJ_TYPE:
3648 case AUDIT_SUBJ_SEN:
3649 case AUDIT_SUBJ_CLR:
3650 case AUDIT_OBJ_USER:
3651 case AUDIT_OBJ_ROLE:
3652 case AUDIT_OBJ_TYPE:
3653 case AUDIT_OBJ_LEV_LOW:
3654 case AUDIT_OBJ_LEV_HIGH:
3655 return 1;
3656 }
3657 }
3658
3659 return 0;
3660}
3661
3662int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule)
3663{
3664 struct selinux_state *state = &selinux_state;
3665 struct selinux_policy *policy;
3666 struct context *ctxt;
3667 struct mls_level *level;
3668 struct selinux_audit_rule *rule = vrule;
3669 int match = 0;
3670
3671 if (unlikely(!rule)) {
3672 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3673 return -ENOENT;
3674 }
3675
3676 if (!selinux_initialized())
3677 return 0;
3678
3679 rcu_read_lock();
3680
3681 policy = rcu_dereference(state->policy);
3682
3683 if (rule->au_seqno < policy->latest_granting) {
3684 match = -ESTALE;
3685 goto out;
3686 }
3687
3688 ctxt = sidtab_search(policy->sidtab, prop->selinux.secid);
3689 if (unlikely(!ctxt)) {
3690 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3691 prop->selinux.secid);
3692 match = -ENOENT;
3693 goto out;
3694 }
3695
3696 /* a field/op pair that is not caught here will simply fall through
3697 without a match */
3698 switch (field) {
3699 case AUDIT_SUBJ_USER:
3700 case AUDIT_OBJ_USER:
3701 switch (op) {
3702 case Audit_equal:
3703 match = (ctxt->user == rule->au_ctxt.user);
3704 break;
3705 case Audit_not_equal:
3706 match = (ctxt->user != rule->au_ctxt.user);
3707 break;
3708 }
3709 break;
3710 case AUDIT_SUBJ_ROLE:
3711 case AUDIT_OBJ_ROLE:
3712 switch (op) {
3713 case Audit_equal:
3714 match = (ctxt->role == rule->au_ctxt.role);
3715 break;
3716 case Audit_not_equal:
3717 match = (ctxt->role != rule->au_ctxt.role);
3718 break;
3719 }
3720 break;
3721 case AUDIT_SUBJ_TYPE:
3722 case AUDIT_OBJ_TYPE:
3723 switch (op) {
3724 case Audit_equal:
3725 match = (ctxt->type == rule->au_ctxt.type);
3726 break;
3727 case Audit_not_equal:
3728 match = (ctxt->type != rule->au_ctxt.type);
3729 break;
3730 }
3731 break;
3732 case AUDIT_SUBJ_SEN:
3733 case AUDIT_SUBJ_CLR:
3734 case AUDIT_OBJ_LEV_LOW:
3735 case AUDIT_OBJ_LEV_HIGH:
3736 level = ((field == AUDIT_SUBJ_SEN ||
3737 field == AUDIT_OBJ_LEV_LOW) ?
3738 &ctxt->range.level[0] : &ctxt->range.level[1]);
3739 switch (op) {
3740 case Audit_equal:
3741 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3742 level);
3743 break;
3744 case Audit_not_equal:
3745 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3746 level);
3747 break;
3748 case Audit_lt:
3749 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3750 level) &&
3751 !mls_level_eq(&rule->au_ctxt.range.level[0],
3752 level));
3753 break;
3754 case Audit_le:
3755 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3756 level);
3757 break;
3758 case Audit_gt:
3759 match = (mls_level_dom(level,
3760 &rule->au_ctxt.range.level[0]) &&
3761 !mls_level_eq(level,
3762 &rule->au_ctxt.range.level[0]));
3763 break;
3764 case Audit_ge:
3765 match = mls_level_dom(level,
3766 &rule->au_ctxt.range.level[0]);
3767 break;
3768 }
3769 }
3770
3771out:
3772 rcu_read_unlock();
3773 return match;
3774}
3775
3776static int aurule_avc_callback(u32 event)
3777{
3778 if (event == AVC_CALLBACK_RESET)
3779 return audit_update_lsm_rules();
3780 return 0;
3781}
3782
3783static int __init aurule_init(void)
3784{
3785 int err;
3786
3787 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3788 if (err)
3789 panic("avc_add_callback() failed, error %d\n", err);
3790
3791 return err;
3792}
3793__initcall(aurule_init);
3794
3795#ifdef CONFIG_NETLABEL
3796/**
3797 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3798 * @secattr: the NetLabel packet security attributes
3799 * @sid: the SELinux SID
3800 *
3801 * Description:
3802 * Attempt to cache the context in @ctx, which was derived from the packet in
3803 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3804 * already been initialized.
3805 *
3806 */
3807static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3808 u32 sid)
3809{
3810 u32 *sid_cache;
3811
3812 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3813 if (sid_cache == NULL)
3814 return;
3815 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3816 if (secattr->cache == NULL) {
3817 kfree(sid_cache);
3818 return;
3819 }
3820
3821 *sid_cache = sid;
3822 secattr->cache->free = kfree;
3823 secattr->cache->data = sid_cache;
3824 secattr->flags |= NETLBL_SECATTR_CACHE;
3825}
3826
3827/**
3828 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3829 * @secattr: the NetLabel packet security attributes
3830 * @sid: the SELinux SID
3831 *
3832 * Description:
3833 * Convert the given NetLabel security attributes in @secattr into a
3834 * SELinux SID. If the @secattr field does not contain a full SELinux
3835 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3836 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3837 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3838 * conversion for future lookups. Returns zero on success, negative values on
3839 * failure.
3840 *
3841 */
3842int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3843 u32 *sid)
3844{
3845 struct selinux_policy *policy;
3846 struct policydb *policydb;
3847 struct sidtab *sidtab;
3848 int rc;
3849 struct context *ctx;
3850 struct context ctx_new;
3851
3852 if (!selinux_initialized()) {
3853 *sid = SECSID_NULL;
3854 return 0;
3855 }
3856
3857retry:
3858 rc = 0;
3859 rcu_read_lock();
3860 policy = rcu_dereference(selinux_state.policy);
3861 policydb = &policy->policydb;
3862 sidtab = policy->sidtab;
3863
3864 if (secattr->flags & NETLBL_SECATTR_CACHE)
3865 *sid = *(u32 *)secattr->cache->data;
3866 else if (secattr->flags & NETLBL_SECATTR_SECID)
3867 *sid = secattr->attr.secid;
3868 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3869 rc = -EIDRM;
3870 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3871 if (ctx == NULL)
3872 goto out;
3873
3874 context_init(&ctx_new);
3875 ctx_new.user = ctx->user;
3876 ctx_new.role = ctx->role;
3877 ctx_new.type = ctx->type;
3878 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3879 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3880 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3881 if (rc)
3882 goto out;
3883 }
3884 rc = -EIDRM;
3885 if (!mls_context_isvalid(policydb, &ctx_new)) {
3886 ebitmap_destroy(&ctx_new.range.level[0].cat);
3887 goto out;
3888 }
3889
3890 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3891 ebitmap_destroy(&ctx_new.range.level[0].cat);
3892 if (rc == -ESTALE) {
3893 rcu_read_unlock();
3894 goto retry;
3895 }
3896 if (rc)
3897 goto out;
3898
3899 security_netlbl_cache_add(secattr, *sid);
3900 } else
3901 *sid = SECSID_NULL;
3902
3903out:
3904 rcu_read_unlock();
3905 return rc;
3906}
3907
3908/**
3909 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3910 * @sid: the SELinux SID
3911 * @secattr: the NetLabel packet security attributes
3912 *
3913 * Description:
3914 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3915 * Returns zero on success, negative values on failure.
3916 *
3917 */
3918int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3919{
3920 struct selinux_policy *policy;
3921 struct policydb *policydb;
3922 int rc;
3923 struct context *ctx;
3924
3925 if (!selinux_initialized())
3926 return 0;
3927
3928 rcu_read_lock();
3929 policy = rcu_dereference(selinux_state.policy);
3930 policydb = &policy->policydb;
3931
3932 rc = -ENOENT;
3933 ctx = sidtab_search(policy->sidtab, sid);
3934 if (ctx == NULL)
3935 goto out;
3936
3937 rc = -ENOMEM;
3938 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3939 GFP_ATOMIC);
3940 if (secattr->domain == NULL)
3941 goto out;
3942
3943 secattr->attr.secid = sid;
3944 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3945 mls_export_netlbl_lvl(policydb, ctx, secattr);
3946 rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3947out:
3948 rcu_read_unlock();
3949 return rc;
3950}
3951#endif /* CONFIG_NETLABEL */
3952
3953/**
3954 * __security_read_policy - read the policy.
3955 * @policy: SELinux policy
3956 * @data: binary policy data
3957 * @len: length of data in bytes
3958 *
3959 */
3960static int __security_read_policy(struct selinux_policy *policy,
3961 void *data, size_t *len)
3962{
3963 int rc;
3964 struct policy_file fp;
3965
3966 fp.data = data;
3967 fp.len = *len;
3968
3969 rc = policydb_write(&policy->policydb, &fp);
3970 if (rc)
3971 return rc;
3972
3973 *len = (unsigned long)fp.data - (unsigned long)data;
3974 return 0;
3975}
3976
3977/**
3978 * security_read_policy - read the policy.
3979 * @data: binary policy data
3980 * @len: length of data in bytes
3981 *
3982 */
3983int security_read_policy(void **data, size_t *len)
3984{
3985 struct selinux_state *state = &selinux_state;
3986 struct selinux_policy *policy;
3987
3988 policy = rcu_dereference_protected(
3989 state->policy, lockdep_is_held(&state->policy_mutex));
3990 if (!policy)
3991 return -EINVAL;
3992
3993 *len = policy->policydb.len;
3994 *data = vmalloc_user(*len);
3995 if (!*data)
3996 return -ENOMEM;
3997
3998 return __security_read_policy(policy, *data, len);
3999}
4000
4001/**
4002 * security_read_state_kernel - read the policy.
4003 * @data: binary policy data
4004 * @len: length of data in bytes
4005 *
4006 * Allocates kernel memory for reading SELinux policy.
4007 * This function is for internal use only and should not
4008 * be used for returning data to user space.
4009 *
4010 * This function must be called with policy_mutex held.
4011 */
4012int security_read_state_kernel(void **data, size_t *len)
4013{
4014 int err;
4015 struct selinux_state *state = &selinux_state;
4016 struct selinux_policy *policy;
4017
4018 policy = rcu_dereference_protected(
4019 state->policy, lockdep_is_held(&state->policy_mutex));
4020 if (!policy)
4021 return -EINVAL;
4022
4023 *len = policy->policydb.len;
4024 *data = vmalloc(*len);
4025 if (!*data)
4026 return -ENOMEM;
4027
4028 err = __security_read_policy(policy, *data, len);
4029 if (err) {
4030 vfree(*data);
4031 *data = NULL;
4032 *len = 0;
4033 }
4034 return err;
4035}