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