Loading...
1/*
2 * Implementation of the security services.
3 *
4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5 * James Morris <jmorris@redhat.com>
6 *
7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8 *
9 * Support for enhanced MLS infrastructure.
10 * Support for context based audit filters.
11 *
12 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13 *
14 * Added conditional policy language extensions
15 *
16 * Updated: Hewlett-Packard <paul@paul-moore.com>
17 *
18 * Added support for NetLabel
19 * Added support for the policy capability bitmap
20 *
21 * Updated: Chad Sellers <csellers@tresys.com>
22 *
23 * Added validation of kernel classes and permissions
24 *
25 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26 *
27 * Added support for bounds domain and audit messaged on masked permissions
28 *
29 * Updated: Guido Trentalancia <guido@trentalancia.com>
30 *
31 * Added support for runtime switching of the policy type
32 *
33 * Copyright (C) 2008, 2009 NEC Corporation
34 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38 * This program is free software; you can redistribute it and/or modify
39 * it under the terms of the GNU General Public License as published by
40 * the Free Software Foundation, version 2.
41 */
42#include <linux/kernel.h>
43#include <linux/slab.h>
44#include <linux/string.h>
45#include <linux/spinlock.h>
46#include <linux/rcupdate.h>
47#include <linux/errno.h>
48#include <linux/in.h>
49#include <linux/sched.h>
50#include <linux/audit.h>
51#include <linux/mutex.h>
52#include <linux/selinux.h>
53#include <linux/flex_array.h>
54#include <linux/vmalloc.h>
55#include <net/netlabel.h>
56
57#include "flask.h"
58#include "avc.h"
59#include "avc_ss.h"
60#include "security.h"
61#include "context.h"
62#include "policydb.h"
63#include "sidtab.h"
64#include "services.h"
65#include "conditional.h"
66#include "mls.h"
67#include "objsec.h"
68#include "netlabel.h"
69#include "xfrm.h"
70#include "ebitmap.h"
71#include "audit.h"
72
73extern void selnl_notify_policyload(u32 seqno);
74
75int selinux_policycap_netpeer;
76int selinux_policycap_openperm;
77
78static DEFINE_RWLOCK(policy_rwlock);
79
80static struct sidtab sidtab;
81struct policydb policydb;
82int ss_initialized;
83
84/*
85 * The largest sequence number that has been used when
86 * providing an access decision to the access vector cache.
87 * The sequence number only changes when a policy change
88 * occurs.
89 */
90static u32 latest_granting;
91
92/* Forward declaration. */
93static int context_struct_to_string(struct context *context, char **scontext,
94 u32 *scontext_len);
95
96static void context_struct_compute_av(struct context *scontext,
97 struct context *tcontext,
98 u16 tclass,
99 struct av_decision *avd);
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 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
571 return; /* no masked permission */
572 masked = ~lo_avd.allowed & avd->allowed;
573 }
574
575 if (target->bounds) {
576 memset(&lo_avd, 0, sizeof(lo_avd));
577
578 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
579 lo_tcontext.type = target->bounds;
580
581 context_struct_compute_av(scontext,
582 &lo_tcontext,
583 tclass,
584 &lo_avd);
585 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
586 return; /* no masked permission */
587 masked = ~lo_avd.allowed & avd->allowed;
588 }
589
590 if (source->bounds && target->bounds) {
591 memset(&lo_avd, 0, sizeof(lo_avd));
592 /*
593 * lo_scontext and lo_tcontext are already
594 * set up.
595 */
596
597 context_struct_compute_av(&lo_scontext,
598 &lo_tcontext,
599 tclass,
600 &lo_avd);
601 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
602 return; /* no masked permission */
603 masked = ~lo_avd.allowed & avd->allowed;
604 }
605
606 if (masked) {
607 /* mask violated permissions */
608 avd->allowed &= ~masked;
609
610 /* audit masked permissions */
611 security_dump_masked_av(scontext, tcontext,
612 tclass, masked, "bounds");
613 }
614}
615
616/*
617 * Compute access vectors based on a context structure pair for
618 * the permissions in a particular class.
619 */
620static void context_struct_compute_av(struct context *scontext,
621 struct context *tcontext,
622 u16 tclass,
623 struct av_decision *avd)
624{
625 struct constraint_node *constraint;
626 struct role_allow *ra;
627 struct avtab_key avkey;
628 struct avtab_node *node;
629 struct class_datum *tclass_datum;
630 struct ebitmap *sattr, *tattr;
631 struct ebitmap_node *snode, *tnode;
632 unsigned int i, j;
633
634 avd->allowed = 0;
635 avd->auditallow = 0;
636 avd->auditdeny = 0xffffffff;
637
638 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
639 if (printk_ratelimit())
640 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
641 return;
642 }
643
644 tclass_datum = policydb.class_val_to_struct[tclass - 1];
645
646 /*
647 * If a specific type enforcement rule was defined for
648 * this permission check, then use it.
649 */
650 avkey.target_class = tclass;
651 avkey.specified = AVTAB_AV;
652 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
653 BUG_ON(!sattr);
654 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
655 BUG_ON(!tattr);
656 ebitmap_for_each_positive_bit(sattr, snode, i) {
657 ebitmap_for_each_positive_bit(tattr, tnode, j) {
658 avkey.source_type = i + 1;
659 avkey.target_type = j + 1;
660 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
661 node;
662 node = avtab_search_node_next(node, avkey.specified)) {
663 if (node->key.specified == AVTAB_ALLOWED)
664 avd->allowed |= node->datum.data;
665 else if (node->key.specified == AVTAB_AUDITALLOW)
666 avd->auditallow |= node->datum.data;
667 else if (node->key.specified == AVTAB_AUDITDENY)
668 avd->auditdeny &= node->datum.data;
669 }
670
671 /* Check conditional av table for additional permissions */
672 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
673
674 }
675 }
676
677 /*
678 * Remove any permissions prohibited by a constraint (this includes
679 * the MLS policy).
680 */
681 constraint = tclass_datum->constraints;
682 while (constraint) {
683 if ((constraint->permissions & (avd->allowed)) &&
684 !constraint_expr_eval(scontext, tcontext, NULL,
685 constraint->expr)) {
686 avd->allowed &= ~(constraint->permissions);
687 }
688 constraint = constraint->next;
689 }
690
691 /*
692 * If checking process transition permission and the
693 * role is changing, then check the (current_role, new_role)
694 * pair.
695 */
696 if (tclass == policydb.process_class &&
697 (avd->allowed & policydb.process_trans_perms) &&
698 scontext->role != tcontext->role) {
699 for (ra = policydb.role_allow; ra; ra = ra->next) {
700 if (scontext->role == ra->role &&
701 tcontext->role == ra->new_role)
702 break;
703 }
704 if (!ra)
705 avd->allowed &= ~policydb.process_trans_perms;
706 }
707
708 /*
709 * If the given source and target types have boundary
710 * constraint, lazy checks have to mask any violated
711 * permission and notice it to userspace via audit.
712 */
713 type_attribute_bounds_av(scontext, tcontext,
714 tclass, avd);
715}
716
717static int security_validtrans_handle_fail(struct context *ocontext,
718 struct context *ncontext,
719 struct context *tcontext,
720 u16 tclass)
721{
722 char *o = NULL, *n = NULL, *t = NULL;
723 u32 olen, nlen, tlen;
724
725 if (context_struct_to_string(ocontext, &o, &olen))
726 goto out;
727 if (context_struct_to_string(ncontext, &n, &nlen))
728 goto out;
729 if (context_struct_to_string(tcontext, &t, &tlen))
730 goto out;
731 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
732 "security_validate_transition: denied for"
733 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
734 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
735out:
736 kfree(o);
737 kfree(n);
738 kfree(t);
739
740 if (!selinux_enforcing)
741 return 0;
742 return -EPERM;
743}
744
745int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
746 u16 orig_tclass)
747{
748 struct context *ocontext;
749 struct context *ncontext;
750 struct context *tcontext;
751 struct class_datum *tclass_datum;
752 struct constraint_node *constraint;
753 u16 tclass;
754 int rc = 0;
755
756 if (!ss_initialized)
757 return 0;
758
759 read_lock(&policy_rwlock);
760
761 tclass = unmap_class(orig_tclass);
762
763 if (!tclass || tclass > policydb.p_classes.nprim) {
764 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
765 __func__, tclass);
766 rc = -EINVAL;
767 goto out;
768 }
769 tclass_datum = policydb.class_val_to_struct[tclass - 1];
770
771 ocontext = sidtab_search(&sidtab, oldsid);
772 if (!ocontext) {
773 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
774 __func__, oldsid);
775 rc = -EINVAL;
776 goto out;
777 }
778
779 ncontext = sidtab_search(&sidtab, newsid);
780 if (!ncontext) {
781 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
782 __func__, newsid);
783 rc = -EINVAL;
784 goto out;
785 }
786
787 tcontext = sidtab_search(&sidtab, tasksid);
788 if (!tcontext) {
789 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
790 __func__, tasksid);
791 rc = -EINVAL;
792 goto out;
793 }
794
795 constraint = tclass_datum->validatetrans;
796 while (constraint) {
797 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
798 constraint->expr)) {
799 rc = security_validtrans_handle_fail(ocontext, ncontext,
800 tcontext, tclass);
801 goto out;
802 }
803 constraint = constraint->next;
804 }
805
806out:
807 read_unlock(&policy_rwlock);
808 return rc;
809}
810
811/*
812 * security_bounded_transition - check whether the given
813 * transition is directed to bounded, or not.
814 * It returns 0, if @newsid is bounded by @oldsid.
815 * Otherwise, it returns error code.
816 *
817 * @oldsid : current security identifier
818 * @newsid : destinated security identifier
819 */
820int security_bounded_transition(u32 old_sid, u32 new_sid)
821{
822 struct context *old_context, *new_context;
823 struct type_datum *type;
824 int index;
825 int rc;
826
827 read_lock(&policy_rwlock);
828
829 rc = -EINVAL;
830 old_context = sidtab_search(&sidtab, old_sid);
831 if (!old_context) {
832 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
833 __func__, old_sid);
834 goto out;
835 }
836
837 rc = -EINVAL;
838 new_context = sidtab_search(&sidtab, new_sid);
839 if (!new_context) {
840 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
841 __func__, new_sid);
842 goto out;
843 }
844
845 rc = 0;
846 /* type/domain unchanged */
847 if (old_context->type == new_context->type)
848 goto out;
849
850 index = new_context->type;
851 while (true) {
852 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
853 index - 1);
854 BUG_ON(!type);
855
856 /* not bounded anymore */
857 rc = -EPERM;
858 if (!type->bounds)
859 break;
860
861 /* @newsid is bounded by @oldsid */
862 rc = 0;
863 if (type->bounds == old_context->type)
864 break;
865
866 index = type->bounds;
867 }
868
869 if (rc) {
870 char *old_name = NULL;
871 char *new_name = NULL;
872 u32 length;
873
874 if (!context_struct_to_string(old_context,
875 &old_name, &length) &&
876 !context_struct_to_string(new_context,
877 &new_name, &length)) {
878 audit_log(current->audit_context,
879 GFP_ATOMIC, AUDIT_SELINUX_ERR,
880 "op=security_bounded_transition "
881 "result=denied "
882 "oldcontext=%s newcontext=%s",
883 old_name, new_name);
884 }
885 kfree(new_name);
886 kfree(old_name);
887 }
888out:
889 read_unlock(&policy_rwlock);
890
891 return rc;
892}
893
894static void avd_init(struct av_decision *avd)
895{
896 avd->allowed = 0;
897 avd->auditallow = 0;
898 avd->auditdeny = 0xffffffff;
899 avd->seqno = latest_granting;
900 avd->flags = 0;
901}
902
903
904/**
905 * security_compute_av - Compute access vector decisions.
906 * @ssid: source security identifier
907 * @tsid: target security identifier
908 * @tclass: target security class
909 * @avd: access vector decisions
910 *
911 * Compute a set of access vector decisions based on the
912 * SID pair (@ssid, @tsid) for the permissions in @tclass.
913 */
914void security_compute_av(u32 ssid,
915 u32 tsid,
916 u16 orig_tclass,
917 struct av_decision *avd)
918{
919 u16 tclass;
920 struct context *scontext = NULL, *tcontext = NULL;
921
922 read_lock(&policy_rwlock);
923 avd_init(avd);
924 if (!ss_initialized)
925 goto allow;
926
927 scontext = sidtab_search(&sidtab, ssid);
928 if (!scontext) {
929 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
930 __func__, ssid);
931 goto out;
932 }
933
934 /* permissive domain? */
935 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
936 avd->flags |= AVD_FLAGS_PERMISSIVE;
937
938 tcontext = sidtab_search(&sidtab, tsid);
939 if (!tcontext) {
940 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
941 __func__, tsid);
942 goto out;
943 }
944
945 tclass = unmap_class(orig_tclass);
946 if (unlikely(orig_tclass && !tclass)) {
947 if (policydb.allow_unknown)
948 goto allow;
949 goto out;
950 }
951 context_struct_compute_av(scontext, tcontext, tclass, avd);
952 map_decision(orig_tclass, avd, policydb.allow_unknown);
953out:
954 read_unlock(&policy_rwlock);
955 return;
956allow:
957 avd->allowed = 0xffffffff;
958 goto out;
959}
960
961void security_compute_av_user(u32 ssid,
962 u32 tsid,
963 u16 tclass,
964 struct av_decision *avd)
965{
966 struct context *scontext = NULL, *tcontext = NULL;
967
968 read_lock(&policy_rwlock);
969 avd_init(avd);
970 if (!ss_initialized)
971 goto allow;
972
973 scontext = sidtab_search(&sidtab, ssid);
974 if (!scontext) {
975 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
976 __func__, ssid);
977 goto out;
978 }
979
980 /* permissive domain? */
981 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
982 avd->flags |= AVD_FLAGS_PERMISSIVE;
983
984 tcontext = sidtab_search(&sidtab, tsid);
985 if (!tcontext) {
986 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
987 __func__, tsid);
988 goto out;
989 }
990
991 if (unlikely(!tclass)) {
992 if (policydb.allow_unknown)
993 goto allow;
994 goto out;
995 }
996
997 context_struct_compute_av(scontext, tcontext, tclass, avd);
998 out:
999 read_unlock(&policy_rwlock);
1000 return;
1001allow:
1002 avd->allowed = 0xffffffff;
1003 goto out;
1004}
1005
1006/*
1007 * Write the security context string representation of
1008 * the context structure `context' into a dynamically
1009 * allocated string of the correct size. Set `*scontext'
1010 * to point to this string and set `*scontext_len' to
1011 * the length of the string.
1012 */
1013static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1014{
1015 char *scontextp;
1016
1017 if (scontext)
1018 *scontext = NULL;
1019 *scontext_len = 0;
1020
1021 if (context->len) {
1022 *scontext_len = context->len;
1023 *scontext = kstrdup(context->str, GFP_ATOMIC);
1024 if (!(*scontext))
1025 return -ENOMEM;
1026 return 0;
1027 }
1028
1029 /* Compute the size of the context. */
1030 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1031 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1032 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1033 *scontext_len += mls_compute_context_len(context);
1034
1035 if (!scontext)
1036 return 0;
1037
1038 /* Allocate space for the context; caller must free this space. */
1039 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1040 if (!scontextp)
1041 return -ENOMEM;
1042 *scontext = scontextp;
1043
1044 /*
1045 * Copy the user name, role name and type name into the context.
1046 */
1047 sprintf(scontextp, "%s:%s:%s",
1048 sym_name(&policydb, SYM_USERS, context->user - 1),
1049 sym_name(&policydb, SYM_ROLES, context->role - 1),
1050 sym_name(&policydb, SYM_TYPES, context->type - 1));
1051 scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1052 1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1053 1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1054
1055 mls_sid_to_context(context, &scontextp);
1056
1057 *scontextp = 0;
1058
1059 return 0;
1060}
1061
1062#include "initial_sid_to_string.h"
1063
1064const char *security_get_initial_sid_context(u32 sid)
1065{
1066 if (unlikely(sid > SECINITSID_NUM))
1067 return NULL;
1068 return initial_sid_to_string[sid];
1069}
1070
1071static int security_sid_to_context_core(u32 sid, char **scontext,
1072 u32 *scontext_len, int force)
1073{
1074 struct context *context;
1075 int rc = 0;
1076
1077 if (scontext)
1078 *scontext = NULL;
1079 *scontext_len = 0;
1080
1081 if (!ss_initialized) {
1082 if (sid <= SECINITSID_NUM) {
1083 char *scontextp;
1084
1085 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1086 if (!scontext)
1087 goto out;
1088 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1089 if (!scontextp) {
1090 rc = -ENOMEM;
1091 goto out;
1092 }
1093 strcpy(scontextp, initial_sid_to_string[sid]);
1094 *scontext = scontextp;
1095 goto out;
1096 }
1097 printk(KERN_ERR "SELinux: %s: called before initial "
1098 "load_policy on unknown SID %d\n", __func__, sid);
1099 rc = -EINVAL;
1100 goto out;
1101 }
1102 read_lock(&policy_rwlock);
1103 if (force)
1104 context = sidtab_search_force(&sidtab, sid);
1105 else
1106 context = sidtab_search(&sidtab, sid);
1107 if (!context) {
1108 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1109 __func__, sid);
1110 rc = -EINVAL;
1111 goto out_unlock;
1112 }
1113 rc = context_struct_to_string(context, scontext, scontext_len);
1114out_unlock:
1115 read_unlock(&policy_rwlock);
1116out:
1117 return rc;
1118
1119}
1120
1121/**
1122 * security_sid_to_context - Obtain a context for a given SID.
1123 * @sid: security identifier, SID
1124 * @scontext: security context
1125 * @scontext_len: length in bytes
1126 *
1127 * Write the string representation of the context associated with @sid
1128 * into a dynamically allocated string of the correct size. Set @scontext
1129 * to point to this string and set @scontext_len to the length of the string.
1130 */
1131int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1132{
1133 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1134}
1135
1136int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1137{
1138 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1139}
1140
1141/*
1142 * Caveat: Mutates scontext.
1143 */
1144static int string_to_context_struct(struct policydb *pol,
1145 struct sidtab *sidtabp,
1146 char *scontext,
1147 u32 scontext_len,
1148 struct context *ctx,
1149 u32 def_sid)
1150{
1151 struct role_datum *role;
1152 struct type_datum *typdatum;
1153 struct user_datum *usrdatum;
1154 char *scontextp, *p, oldc;
1155 int rc = 0;
1156
1157 context_init(ctx);
1158
1159 /* Parse the security context. */
1160
1161 rc = -EINVAL;
1162 scontextp = (char *) scontext;
1163
1164 /* Extract the user. */
1165 p = scontextp;
1166 while (*p && *p != ':')
1167 p++;
1168
1169 if (*p == 0)
1170 goto out;
1171
1172 *p++ = 0;
1173
1174 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1175 if (!usrdatum)
1176 goto out;
1177
1178 ctx->user = usrdatum->value;
1179
1180 /* Extract role. */
1181 scontextp = p;
1182 while (*p && *p != ':')
1183 p++;
1184
1185 if (*p == 0)
1186 goto out;
1187
1188 *p++ = 0;
1189
1190 role = hashtab_search(pol->p_roles.table, scontextp);
1191 if (!role)
1192 goto out;
1193 ctx->role = role->value;
1194
1195 /* Extract type. */
1196 scontextp = p;
1197 while (*p && *p != ':')
1198 p++;
1199 oldc = *p;
1200 *p++ = 0;
1201
1202 typdatum = hashtab_search(pol->p_types.table, scontextp);
1203 if (!typdatum || typdatum->attribute)
1204 goto out;
1205
1206 ctx->type = typdatum->value;
1207
1208 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1209 if (rc)
1210 goto out;
1211
1212 rc = -EINVAL;
1213 if ((p - scontext) < scontext_len)
1214 goto out;
1215
1216 /* Check the validity of the new context. */
1217 if (!policydb_context_isvalid(pol, ctx))
1218 goto out;
1219 rc = 0;
1220out:
1221 if (rc)
1222 context_destroy(ctx);
1223 return rc;
1224}
1225
1226static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1227 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1228 int force)
1229{
1230 char *scontext2, *str = NULL;
1231 struct context context;
1232 int rc = 0;
1233
1234 if (!ss_initialized) {
1235 int i;
1236
1237 for (i = 1; i < SECINITSID_NUM; i++) {
1238 if (!strcmp(initial_sid_to_string[i], scontext)) {
1239 *sid = i;
1240 return 0;
1241 }
1242 }
1243 *sid = SECINITSID_KERNEL;
1244 return 0;
1245 }
1246 *sid = SECSID_NULL;
1247
1248 /* Copy the string so that we can modify the copy as we parse it. */
1249 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1250 if (!scontext2)
1251 return -ENOMEM;
1252 memcpy(scontext2, scontext, scontext_len);
1253 scontext2[scontext_len] = 0;
1254
1255 if (force) {
1256 /* Save another copy for storing in uninterpreted form */
1257 rc = -ENOMEM;
1258 str = kstrdup(scontext2, gfp_flags);
1259 if (!str)
1260 goto out;
1261 }
1262
1263 read_lock(&policy_rwlock);
1264 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1265 scontext_len, &context, def_sid);
1266 if (rc == -EINVAL && force) {
1267 context.str = str;
1268 context.len = scontext_len;
1269 str = NULL;
1270 } else if (rc)
1271 goto out_unlock;
1272 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1273 context_destroy(&context);
1274out_unlock:
1275 read_unlock(&policy_rwlock);
1276out:
1277 kfree(scontext2);
1278 kfree(str);
1279 return rc;
1280}
1281
1282/**
1283 * security_context_to_sid - Obtain a SID for a given security context.
1284 * @scontext: security context
1285 * @scontext_len: length in bytes
1286 * @sid: security identifier, SID
1287 *
1288 * Obtains a SID associated with the security context that
1289 * has the string representation specified by @scontext.
1290 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1291 * memory is available, or 0 on success.
1292 */
1293int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1294{
1295 return security_context_to_sid_core(scontext, scontext_len,
1296 sid, SECSID_NULL, GFP_KERNEL, 0);
1297}
1298
1299/**
1300 * security_context_to_sid_default - Obtain a SID for a given security context,
1301 * falling back to specified default if needed.
1302 *
1303 * @scontext: security context
1304 * @scontext_len: length in bytes
1305 * @sid: security identifier, SID
1306 * @def_sid: default SID to assign on error
1307 *
1308 * Obtains a SID associated with the security context that
1309 * has the string representation specified by @scontext.
1310 * The default SID is passed to the MLS layer to be used to allow
1311 * kernel labeling of the MLS field if the MLS field is not present
1312 * (for upgrading to MLS without full relabel).
1313 * Implicitly forces adding of the context even if it cannot be mapped yet.
1314 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1315 * memory is available, or 0 on success.
1316 */
1317int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1318 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1319{
1320 return security_context_to_sid_core(scontext, scontext_len,
1321 sid, def_sid, gfp_flags, 1);
1322}
1323
1324int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1325 u32 *sid)
1326{
1327 return security_context_to_sid_core(scontext, scontext_len,
1328 sid, SECSID_NULL, GFP_KERNEL, 1);
1329}
1330
1331static int compute_sid_handle_invalid_context(
1332 struct context *scontext,
1333 struct context *tcontext,
1334 u16 tclass,
1335 struct context *newcontext)
1336{
1337 char *s = NULL, *t = NULL, *n = NULL;
1338 u32 slen, tlen, nlen;
1339
1340 if (context_struct_to_string(scontext, &s, &slen))
1341 goto out;
1342 if (context_struct_to_string(tcontext, &t, &tlen))
1343 goto out;
1344 if (context_struct_to_string(newcontext, &n, &nlen))
1345 goto out;
1346 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1347 "security_compute_sid: invalid context %s"
1348 " for scontext=%s"
1349 " tcontext=%s"
1350 " tclass=%s",
1351 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1352out:
1353 kfree(s);
1354 kfree(t);
1355 kfree(n);
1356 if (!selinux_enforcing)
1357 return 0;
1358 return -EACCES;
1359}
1360
1361static void filename_compute_type(struct policydb *p, struct context *newcontext,
1362 u32 stype, u32 ttype, u16 tclass,
1363 const char *objname)
1364{
1365 struct filename_trans ft;
1366 struct filename_trans_datum *otype;
1367
1368 /*
1369 * Most filename trans rules are going to live in specific directories
1370 * like /dev or /var/run. This bitmap will quickly skip rule searches
1371 * if the ttype does not contain any rules.
1372 */
1373 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1374 return;
1375
1376 ft.stype = stype;
1377 ft.ttype = ttype;
1378 ft.tclass = tclass;
1379 ft.name = objname;
1380
1381 otype = hashtab_search(p->filename_trans, &ft);
1382 if (otype)
1383 newcontext->type = otype->otype;
1384}
1385
1386static int security_compute_sid(u32 ssid,
1387 u32 tsid,
1388 u16 orig_tclass,
1389 u32 specified,
1390 const char *objname,
1391 u32 *out_sid,
1392 bool kern)
1393{
1394 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1395 struct role_trans *roletr = NULL;
1396 struct avtab_key avkey;
1397 struct avtab_datum *avdatum;
1398 struct avtab_node *node;
1399 u16 tclass;
1400 int rc = 0;
1401 bool sock;
1402
1403 if (!ss_initialized) {
1404 switch (orig_tclass) {
1405 case SECCLASS_PROCESS: /* kernel value */
1406 *out_sid = ssid;
1407 break;
1408 default:
1409 *out_sid = tsid;
1410 break;
1411 }
1412 goto out;
1413 }
1414
1415 context_init(&newcontext);
1416
1417 read_lock(&policy_rwlock);
1418
1419 if (kern) {
1420 tclass = unmap_class(orig_tclass);
1421 sock = security_is_socket_class(orig_tclass);
1422 } else {
1423 tclass = orig_tclass;
1424 sock = security_is_socket_class(map_class(tclass));
1425 }
1426
1427 scontext = sidtab_search(&sidtab, ssid);
1428 if (!scontext) {
1429 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1430 __func__, ssid);
1431 rc = -EINVAL;
1432 goto out_unlock;
1433 }
1434 tcontext = sidtab_search(&sidtab, tsid);
1435 if (!tcontext) {
1436 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1437 __func__, tsid);
1438 rc = -EINVAL;
1439 goto out_unlock;
1440 }
1441
1442 /* Set the user identity. */
1443 switch (specified) {
1444 case AVTAB_TRANSITION:
1445 case AVTAB_CHANGE:
1446 /* Use the process user identity. */
1447 newcontext.user = scontext->user;
1448 break;
1449 case AVTAB_MEMBER:
1450 /* Use the related object owner. */
1451 newcontext.user = tcontext->user;
1452 break;
1453 }
1454
1455 /* Set the role and type to default values. */
1456 if ((tclass == policydb.process_class) || (sock == true)) {
1457 /* Use the current role and type of process. */
1458 newcontext.role = scontext->role;
1459 newcontext.type = scontext->type;
1460 } else {
1461 /* Use the well-defined object role. */
1462 newcontext.role = OBJECT_R_VAL;
1463 /* Use the type of the related object. */
1464 newcontext.type = tcontext->type;
1465 }
1466
1467 /* Look for a type transition/member/change rule. */
1468 avkey.source_type = scontext->type;
1469 avkey.target_type = tcontext->type;
1470 avkey.target_class = tclass;
1471 avkey.specified = specified;
1472 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1473
1474 /* If no permanent rule, also check for enabled conditional rules */
1475 if (!avdatum) {
1476 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1477 for (; node; node = avtab_search_node_next(node, specified)) {
1478 if (node->key.specified & AVTAB_ENABLED) {
1479 avdatum = &node->datum;
1480 break;
1481 }
1482 }
1483 }
1484
1485 if (avdatum) {
1486 /* Use the type from the type transition/member/change rule. */
1487 newcontext.type = avdatum->data;
1488 }
1489
1490 /* if we have a objname this is a file trans check so check those rules */
1491 if (objname)
1492 filename_compute_type(&policydb, &newcontext, scontext->type,
1493 tcontext->type, tclass, objname);
1494
1495 /* Check for class-specific changes. */
1496 if (specified & AVTAB_TRANSITION) {
1497 /* Look for a role transition rule. */
1498 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1499 if ((roletr->role == scontext->role) &&
1500 (roletr->type == tcontext->type) &&
1501 (roletr->tclass == tclass)) {
1502 /* Use the role transition rule. */
1503 newcontext.role = roletr->new_role;
1504 break;
1505 }
1506 }
1507 }
1508
1509 /* Set the MLS attributes.
1510 This is done last because it may allocate memory. */
1511 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1512 &newcontext, sock);
1513 if (rc)
1514 goto out_unlock;
1515
1516 /* Check the validity of the context. */
1517 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1518 rc = compute_sid_handle_invalid_context(scontext,
1519 tcontext,
1520 tclass,
1521 &newcontext);
1522 if (rc)
1523 goto out_unlock;
1524 }
1525 /* Obtain the sid for the context. */
1526 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1527out_unlock:
1528 read_unlock(&policy_rwlock);
1529 context_destroy(&newcontext);
1530out:
1531 return rc;
1532}
1533
1534/**
1535 * security_transition_sid - Compute the SID for a new subject/object.
1536 * @ssid: source security identifier
1537 * @tsid: target security identifier
1538 * @tclass: target security class
1539 * @out_sid: security identifier for new subject/object
1540 *
1541 * Compute a SID to use for labeling a new subject or object in the
1542 * class @tclass based on a SID pair (@ssid, @tsid).
1543 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1544 * if insufficient memory is available, or %0 if the new SID was
1545 * computed successfully.
1546 */
1547int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1548 const struct qstr *qstr, u32 *out_sid)
1549{
1550 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1551 qstr ? qstr->name : NULL, out_sid, true);
1552}
1553
1554int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1555 const char *objname, u32 *out_sid)
1556{
1557 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1558 objname, out_sid, false);
1559}
1560
1561/**
1562 * security_member_sid - Compute the SID for member selection.
1563 * @ssid: source security identifier
1564 * @tsid: target security identifier
1565 * @tclass: target security class
1566 * @out_sid: security identifier for selected member
1567 *
1568 * Compute a SID to use when selecting a member of a polyinstantiated
1569 * object of class @tclass based on a SID pair (@ssid, @tsid).
1570 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1571 * if insufficient memory is available, or %0 if the SID was
1572 * computed successfully.
1573 */
1574int security_member_sid(u32 ssid,
1575 u32 tsid,
1576 u16 tclass,
1577 u32 *out_sid)
1578{
1579 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1580 out_sid, false);
1581}
1582
1583/**
1584 * security_change_sid - Compute the SID for object relabeling.
1585 * @ssid: source security identifier
1586 * @tsid: target security identifier
1587 * @tclass: target security class
1588 * @out_sid: security identifier for selected member
1589 *
1590 * Compute a SID to use for relabeling an object of class @tclass
1591 * based on a SID pair (@ssid, @tsid).
1592 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1593 * if insufficient memory is available, or %0 if the SID was
1594 * computed successfully.
1595 */
1596int security_change_sid(u32 ssid,
1597 u32 tsid,
1598 u16 tclass,
1599 u32 *out_sid)
1600{
1601 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1602 out_sid, false);
1603}
1604
1605/* Clone the SID into the new SID table. */
1606static int clone_sid(u32 sid,
1607 struct context *context,
1608 void *arg)
1609{
1610 struct sidtab *s = arg;
1611
1612 if (sid > SECINITSID_NUM)
1613 return sidtab_insert(s, sid, context);
1614 else
1615 return 0;
1616}
1617
1618static inline int convert_context_handle_invalid_context(struct context *context)
1619{
1620 char *s;
1621 u32 len;
1622
1623 if (selinux_enforcing)
1624 return -EINVAL;
1625
1626 if (!context_struct_to_string(context, &s, &len)) {
1627 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1628 kfree(s);
1629 }
1630 return 0;
1631}
1632
1633struct convert_context_args {
1634 struct policydb *oldp;
1635 struct policydb *newp;
1636};
1637
1638/*
1639 * Convert the values in the security context
1640 * structure `c' from the values specified
1641 * in the policy `p->oldp' to the values specified
1642 * in the policy `p->newp'. Verify that the
1643 * context is valid under the new policy.
1644 */
1645static int convert_context(u32 key,
1646 struct context *c,
1647 void *p)
1648{
1649 struct convert_context_args *args;
1650 struct context oldc;
1651 struct ocontext *oc;
1652 struct mls_range *range;
1653 struct role_datum *role;
1654 struct type_datum *typdatum;
1655 struct user_datum *usrdatum;
1656 char *s;
1657 u32 len;
1658 int rc = 0;
1659
1660 if (key <= SECINITSID_NUM)
1661 goto out;
1662
1663 args = p;
1664
1665 if (c->str) {
1666 struct context ctx;
1667
1668 rc = -ENOMEM;
1669 s = kstrdup(c->str, GFP_KERNEL);
1670 if (!s)
1671 goto out;
1672
1673 rc = string_to_context_struct(args->newp, NULL, s,
1674 c->len, &ctx, SECSID_NULL);
1675 kfree(s);
1676 if (!rc) {
1677 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1678 c->str);
1679 /* Replace string with mapped representation. */
1680 kfree(c->str);
1681 memcpy(c, &ctx, sizeof(*c));
1682 goto out;
1683 } else if (rc == -EINVAL) {
1684 /* Retain string representation for later mapping. */
1685 rc = 0;
1686 goto out;
1687 } else {
1688 /* Other error condition, e.g. ENOMEM. */
1689 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1690 c->str, -rc);
1691 goto out;
1692 }
1693 }
1694
1695 rc = context_cpy(&oldc, c);
1696 if (rc)
1697 goto out;
1698
1699 /* Convert the user. */
1700 rc = -EINVAL;
1701 usrdatum = hashtab_search(args->newp->p_users.table,
1702 sym_name(args->oldp, SYM_USERS, c->user - 1));
1703 if (!usrdatum)
1704 goto bad;
1705 c->user = usrdatum->value;
1706
1707 /* Convert the role. */
1708 rc = -EINVAL;
1709 role = hashtab_search(args->newp->p_roles.table,
1710 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1711 if (!role)
1712 goto bad;
1713 c->role = role->value;
1714
1715 /* Convert the type. */
1716 rc = -EINVAL;
1717 typdatum = hashtab_search(args->newp->p_types.table,
1718 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1719 if (!typdatum)
1720 goto bad;
1721 c->type = typdatum->value;
1722
1723 /* Convert the MLS fields if dealing with MLS policies */
1724 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1725 rc = mls_convert_context(args->oldp, args->newp, c);
1726 if (rc)
1727 goto bad;
1728 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1729 /*
1730 * Switching between MLS and non-MLS policy:
1731 * free any storage used by the MLS fields in the
1732 * context for all existing entries in the sidtab.
1733 */
1734 mls_context_destroy(c);
1735 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1736 /*
1737 * Switching between non-MLS and MLS policy:
1738 * ensure that the MLS fields of the context for all
1739 * existing entries in the sidtab are filled in with a
1740 * suitable default value, likely taken from one of the
1741 * initial SIDs.
1742 */
1743 oc = args->newp->ocontexts[OCON_ISID];
1744 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1745 oc = oc->next;
1746 rc = -EINVAL;
1747 if (!oc) {
1748 printk(KERN_ERR "SELinux: unable to look up"
1749 " the initial SIDs list\n");
1750 goto bad;
1751 }
1752 range = &oc->context[0].range;
1753 rc = mls_range_set(c, range);
1754 if (rc)
1755 goto bad;
1756 }
1757
1758 /* Check the validity of the new context. */
1759 if (!policydb_context_isvalid(args->newp, c)) {
1760 rc = convert_context_handle_invalid_context(&oldc);
1761 if (rc)
1762 goto bad;
1763 }
1764
1765 context_destroy(&oldc);
1766
1767 rc = 0;
1768out:
1769 return rc;
1770bad:
1771 /* Map old representation to string and save it. */
1772 rc = context_struct_to_string(&oldc, &s, &len);
1773 if (rc)
1774 return rc;
1775 context_destroy(&oldc);
1776 context_destroy(c);
1777 c->str = s;
1778 c->len = len;
1779 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1780 c->str);
1781 rc = 0;
1782 goto out;
1783}
1784
1785static void security_load_policycaps(void)
1786{
1787 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1788 POLICYDB_CAPABILITY_NETPEER);
1789 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1790 POLICYDB_CAPABILITY_OPENPERM);
1791}
1792
1793extern void selinux_complete_init(void);
1794static int security_preserve_bools(struct policydb *p);
1795
1796/**
1797 * security_load_policy - Load a security policy configuration.
1798 * @data: binary policy data
1799 * @len: length of data in bytes
1800 *
1801 * Load a new set of security policy configuration data,
1802 * validate it and convert the SID table as necessary.
1803 * This function will flush the access vector cache after
1804 * loading the new policy.
1805 */
1806int security_load_policy(void *data, size_t len)
1807{
1808 struct policydb oldpolicydb, newpolicydb;
1809 struct sidtab oldsidtab, newsidtab;
1810 struct selinux_mapping *oldmap, *map = NULL;
1811 struct convert_context_args args;
1812 u32 seqno;
1813 u16 map_size;
1814 int rc = 0;
1815 struct policy_file file = { data, len }, *fp = &file;
1816
1817 if (!ss_initialized) {
1818 avtab_cache_init();
1819 rc = policydb_read(&policydb, fp);
1820 if (rc) {
1821 avtab_cache_destroy();
1822 return rc;
1823 }
1824
1825 policydb.len = len;
1826 rc = selinux_set_mapping(&policydb, secclass_map,
1827 ¤t_mapping,
1828 ¤t_mapping_size);
1829 if (rc) {
1830 policydb_destroy(&policydb);
1831 avtab_cache_destroy();
1832 return rc;
1833 }
1834
1835 rc = policydb_load_isids(&policydb, &sidtab);
1836 if (rc) {
1837 policydb_destroy(&policydb);
1838 avtab_cache_destroy();
1839 return rc;
1840 }
1841
1842 security_load_policycaps();
1843 ss_initialized = 1;
1844 seqno = ++latest_granting;
1845 selinux_complete_init();
1846 avc_ss_reset(seqno);
1847 selnl_notify_policyload(seqno);
1848 selinux_status_update_policyload(seqno);
1849 selinux_netlbl_cache_invalidate();
1850 selinux_xfrm_notify_policyload();
1851 return 0;
1852 }
1853
1854#if 0
1855 sidtab_hash_eval(&sidtab, "sids");
1856#endif
1857
1858 rc = policydb_read(&newpolicydb, fp);
1859 if (rc)
1860 return rc;
1861
1862 newpolicydb.len = len;
1863 /* If switching between different policy types, log MLS status */
1864 if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1865 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1866 else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1867 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1868
1869 rc = policydb_load_isids(&newpolicydb, &newsidtab);
1870 if (rc) {
1871 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
1872 policydb_destroy(&newpolicydb);
1873 return rc;
1874 }
1875
1876 rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1877 if (rc)
1878 goto err;
1879
1880 rc = security_preserve_bools(&newpolicydb);
1881 if (rc) {
1882 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
1883 goto err;
1884 }
1885
1886 /* Clone the SID table. */
1887 sidtab_shutdown(&sidtab);
1888
1889 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1890 if (rc)
1891 goto err;
1892
1893 /*
1894 * Convert the internal representations of contexts
1895 * in the new SID table.
1896 */
1897 args.oldp = &policydb;
1898 args.newp = &newpolicydb;
1899 rc = sidtab_map(&newsidtab, convert_context, &args);
1900 if (rc) {
1901 printk(KERN_ERR "SELinux: unable to convert the internal"
1902 " representation of contexts in the new SID"
1903 " table\n");
1904 goto err;
1905 }
1906
1907 /* Save the old policydb and SID table to free later. */
1908 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1909 sidtab_set(&oldsidtab, &sidtab);
1910
1911 /* Install the new policydb and SID table. */
1912 write_lock_irq(&policy_rwlock);
1913 memcpy(&policydb, &newpolicydb, sizeof policydb);
1914 sidtab_set(&sidtab, &newsidtab);
1915 security_load_policycaps();
1916 oldmap = current_mapping;
1917 current_mapping = map;
1918 current_mapping_size = map_size;
1919 seqno = ++latest_granting;
1920 write_unlock_irq(&policy_rwlock);
1921
1922 /* Free the old policydb and SID table. */
1923 policydb_destroy(&oldpolicydb);
1924 sidtab_destroy(&oldsidtab);
1925 kfree(oldmap);
1926
1927 avc_ss_reset(seqno);
1928 selnl_notify_policyload(seqno);
1929 selinux_status_update_policyload(seqno);
1930 selinux_netlbl_cache_invalidate();
1931 selinux_xfrm_notify_policyload();
1932
1933 return 0;
1934
1935err:
1936 kfree(map);
1937 sidtab_destroy(&newsidtab);
1938 policydb_destroy(&newpolicydb);
1939 return rc;
1940
1941}
1942
1943size_t security_policydb_len(void)
1944{
1945 size_t len;
1946
1947 read_lock(&policy_rwlock);
1948 len = policydb.len;
1949 read_unlock(&policy_rwlock);
1950
1951 return len;
1952}
1953
1954/**
1955 * security_port_sid - Obtain the SID for a port.
1956 * @protocol: protocol number
1957 * @port: port number
1958 * @out_sid: security identifier
1959 */
1960int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1961{
1962 struct ocontext *c;
1963 int rc = 0;
1964
1965 read_lock(&policy_rwlock);
1966
1967 c = policydb.ocontexts[OCON_PORT];
1968 while (c) {
1969 if (c->u.port.protocol == protocol &&
1970 c->u.port.low_port <= port &&
1971 c->u.port.high_port >= port)
1972 break;
1973 c = c->next;
1974 }
1975
1976 if (c) {
1977 if (!c->sid[0]) {
1978 rc = sidtab_context_to_sid(&sidtab,
1979 &c->context[0],
1980 &c->sid[0]);
1981 if (rc)
1982 goto out;
1983 }
1984 *out_sid = c->sid[0];
1985 } else {
1986 *out_sid = SECINITSID_PORT;
1987 }
1988
1989out:
1990 read_unlock(&policy_rwlock);
1991 return rc;
1992}
1993
1994/**
1995 * security_netif_sid - Obtain the SID for a network interface.
1996 * @name: interface name
1997 * @if_sid: interface SID
1998 */
1999int security_netif_sid(char *name, u32 *if_sid)
2000{
2001 int rc = 0;
2002 struct ocontext *c;
2003
2004 read_lock(&policy_rwlock);
2005
2006 c = policydb.ocontexts[OCON_NETIF];
2007 while (c) {
2008 if (strcmp(name, c->u.name) == 0)
2009 break;
2010 c = c->next;
2011 }
2012
2013 if (c) {
2014 if (!c->sid[0] || !c->sid[1]) {
2015 rc = sidtab_context_to_sid(&sidtab,
2016 &c->context[0],
2017 &c->sid[0]);
2018 if (rc)
2019 goto out;
2020 rc = sidtab_context_to_sid(&sidtab,
2021 &c->context[1],
2022 &c->sid[1]);
2023 if (rc)
2024 goto out;
2025 }
2026 *if_sid = c->sid[0];
2027 } else
2028 *if_sid = SECINITSID_NETIF;
2029
2030out:
2031 read_unlock(&policy_rwlock);
2032 return rc;
2033}
2034
2035static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2036{
2037 int i, fail = 0;
2038
2039 for (i = 0; i < 4; i++)
2040 if (addr[i] != (input[i] & mask[i])) {
2041 fail = 1;
2042 break;
2043 }
2044
2045 return !fail;
2046}
2047
2048/**
2049 * security_node_sid - Obtain the SID for a node (host).
2050 * @domain: communication domain aka address family
2051 * @addrp: address
2052 * @addrlen: address length in bytes
2053 * @out_sid: security identifier
2054 */
2055int security_node_sid(u16 domain,
2056 void *addrp,
2057 u32 addrlen,
2058 u32 *out_sid)
2059{
2060 int rc;
2061 struct ocontext *c;
2062
2063 read_lock(&policy_rwlock);
2064
2065 switch (domain) {
2066 case AF_INET: {
2067 u32 addr;
2068
2069 rc = -EINVAL;
2070 if (addrlen != sizeof(u32))
2071 goto out;
2072
2073 addr = *((u32 *)addrp);
2074
2075 c = policydb.ocontexts[OCON_NODE];
2076 while (c) {
2077 if (c->u.node.addr == (addr & c->u.node.mask))
2078 break;
2079 c = c->next;
2080 }
2081 break;
2082 }
2083
2084 case AF_INET6:
2085 rc = -EINVAL;
2086 if (addrlen != sizeof(u64) * 2)
2087 goto out;
2088 c = policydb.ocontexts[OCON_NODE6];
2089 while (c) {
2090 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2091 c->u.node6.mask))
2092 break;
2093 c = c->next;
2094 }
2095 break;
2096
2097 default:
2098 rc = 0;
2099 *out_sid = SECINITSID_NODE;
2100 goto out;
2101 }
2102
2103 if (c) {
2104 if (!c->sid[0]) {
2105 rc = sidtab_context_to_sid(&sidtab,
2106 &c->context[0],
2107 &c->sid[0]);
2108 if (rc)
2109 goto out;
2110 }
2111 *out_sid = c->sid[0];
2112 } else {
2113 *out_sid = SECINITSID_NODE;
2114 }
2115
2116 rc = 0;
2117out:
2118 read_unlock(&policy_rwlock);
2119 return rc;
2120}
2121
2122#define SIDS_NEL 25
2123
2124/**
2125 * security_get_user_sids - Obtain reachable SIDs for a user.
2126 * @fromsid: starting SID
2127 * @username: username
2128 * @sids: array of reachable SIDs for user
2129 * @nel: number of elements in @sids
2130 *
2131 * Generate the set of SIDs for legal security contexts
2132 * for a given user that can be reached by @fromsid.
2133 * Set *@sids to point to a dynamically allocated
2134 * array containing the set of SIDs. Set *@nel to the
2135 * number of elements in the array.
2136 */
2137
2138int security_get_user_sids(u32 fromsid,
2139 char *username,
2140 u32 **sids,
2141 u32 *nel)
2142{
2143 struct context *fromcon, usercon;
2144 u32 *mysids = NULL, *mysids2, sid;
2145 u32 mynel = 0, maxnel = SIDS_NEL;
2146 struct user_datum *user;
2147 struct role_datum *role;
2148 struct ebitmap_node *rnode, *tnode;
2149 int rc = 0, i, j;
2150
2151 *sids = NULL;
2152 *nel = 0;
2153
2154 if (!ss_initialized)
2155 goto out;
2156
2157 read_lock(&policy_rwlock);
2158
2159 context_init(&usercon);
2160
2161 rc = -EINVAL;
2162 fromcon = sidtab_search(&sidtab, fromsid);
2163 if (!fromcon)
2164 goto out_unlock;
2165
2166 rc = -EINVAL;
2167 user = hashtab_search(policydb.p_users.table, username);
2168 if (!user)
2169 goto out_unlock;
2170
2171 usercon.user = user->value;
2172
2173 rc = -ENOMEM;
2174 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2175 if (!mysids)
2176 goto out_unlock;
2177
2178 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2179 role = policydb.role_val_to_struct[i];
2180 usercon.role = i + 1;
2181 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2182 usercon.type = j + 1;
2183
2184 if (mls_setup_user_range(fromcon, user, &usercon))
2185 continue;
2186
2187 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2188 if (rc)
2189 goto out_unlock;
2190 if (mynel < maxnel) {
2191 mysids[mynel++] = sid;
2192 } else {
2193 rc = -ENOMEM;
2194 maxnel += SIDS_NEL;
2195 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2196 if (!mysids2)
2197 goto out_unlock;
2198 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2199 kfree(mysids);
2200 mysids = mysids2;
2201 mysids[mynel++] = sid;
2202 }
2203 }
2204 }
2205 rc = 0;
2206out_unlock:
2207 read_unlock(&policy_rwlock);
2208 if (rc || !mynel) {
2209 kfree(mysids);
2210 goto out;
2211 }
2212
2213 rc = -ENOMEM;
2214 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2215 if (!mysids2) {
2216 kfree(mysids);
2217 goto out;
2218 }
2219 for (i = 0, j = 0; i < mynel; i++) {
2220 struct av_decision dummy_avd;
2221 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2222 SECCLASS_PROCESS, /* kernel value */
2223 PROCESS__TRANSITION, AVC_STRICT,
2224 &dummy_avd);
2225 if (!rc)
2226 mysids2[j++] = mysids[i];
2227 cond_resched();
2228 }
2229 rc = 0;
2230 kfree(mysids);
2231 *sids = mysids2;
2232 *nel = j;
2233out:
2234 return rc;
2235}
2236
2237/**
2238 * security_genfs_sid - Obtain a SID for a file in a filesystem
2239 * @fstype: filesystem type
2240 * @path: path from root of mount
2241 * @sclass: file security class
2242 * @sid: SID for path
2243 *
2244 * Obtain a SID to use for a file in a filesystem that
2245 * cannot support xattr or use a fixed labeling behavior like
2246 * transition SIDs or task SIDs.
2247 */
2248int security_genfs_sid(const char *fstype,
2249 char *path,
2250 u16 orig_sclass,
2251 u32 *sid)
2252{
2253 int len;
2254 u16 sclass;
2255 struct genfs *genfs;
2256 struct ocontext *c;
2257 int rc, cmp = 0;
2258
2259 while (path[0] == '/' && path[1] == '/')
2260 path++;
2261
2262 read_lock(&policy_rwlock);
2263
2264 sclass = unmap_class(orig_sclass);
2265 *sid = SECINITSID_UNLABELED;
2266
2267 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2268 cmp = strcmp(fstype, genfs->fstype);
2269 if (cmp <= 0)
2270 break;
2271 }
2272
2273 rc = -ENOENT;
2274 if (!genfs || cmp)
2275 goto out;
2276
2277 for (c = genfs->head; c; c = c->next) {
2278 len = strlen(c->u.name);
2279 if ((!c->v.sclass || sclass == c->v.sclass) &&
2280 (strncmp(c->u.name, path, len) == 0))
2281 break;
2282 }
2283
2284 rc = -ENOENT;
2285 if (!c)
2286 goto out;
2287
2288 if (!c->sid[0]) {
2289 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2290 if (rc)
2291 goto out;
2292 }
2293
2294 *sid = c->sid[0];
2295 rc = 0;
2296out:
2297 read_unlock(&policy_rwlock);
2298 return rc;
2299}
2300
2301/**
2302 * security_fs_use - Determine how to handle labeling for a filesystem.
2303 * @fstype: filesystem type
2304 * @behavior: labeling behavior
2305 * @sid: SID for filesystem (superblock)
2306 */
2307int security_fs_use(
2308 const char *fstype,
2309 unsigned int *behavior,
2310 u32 *sid)
2311{
2312 int rc = 0;
2313 struct ocontext *c;
2314
2315 read_lock(&policy_rwlock);
2316
2317 c = policydb.ocontexts[OCON_FSUSE];
2318 while (c) {
2319 if (strcmp(fstype, c->u.name) == 0)
2320 break;
2321 c = c->next;
2322 }
2323
2324 if (c) {
2325 *behavior = c->v.behavior;
2326 if (!c->sid[0]) {
2327 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2328 &c->sid[0]);
2329 if (rc)
2330 goto out;
2331 }
2332 *sid = c->sid[0];
2333 } else {
2334 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2335 if (rc) {
2336 *behavior = SECURITY_FS_USE_NONE;
2337 rc = 0;
2338 } else {
2339 *behavior = SECURITY_FS_USE_GENFS;
2340 }
2341 }
2342
2343out:
2344 read_unlock(&policy_rwlock);
2345 return rc;
2346}
2347
2348int security_get_bools(int *len, char ***names, int **values)
2349{
2350 int i, rc;
2351
2352 read_lock(&policy_rwlock);
2353 *names = NULL;
2354 *values = NULL;
2355
2356 rc = 0;
2357 *len = policydb.p_bools.nprim;
2358 if (!*len)
2359 goto out;
2360
2361 rc = -ENOMEM;
2362 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2363 if (!*names)
2364 goto err;
2365
2366 rc = -ENOMEM;
2367 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2368 if (!*values)
2369 goto err;
2370
2371 for (i = 0; i < *len; i++) {
2372 size_t name_len;
2373
2374 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2375 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2376
2377 rc = -ENOMEM;
2378 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2379 if (!(*names)[i])
2380 goto err;
2381
2382 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2383 (*names)[i][name_len - 1] = 0;
2384 }
2385 rc = 0;
2386out:
2387 read_unlock(&policy_rwlock);
2388 return rc;
2389err:
2390 if (*names) {
2391 for (i = 0; i < *len; i++)
2392 kfree((*names)[i]);
2393 }
2394 kfree(*values);
2395 goto out;
2396}
2397
2398
2399int security_set_bools(int len, int *values)
2400{
2401 int i, rc;
2402 int lenp, seqno = 0;
2403 struct cond_node *cur;
2404
2405 write_lock_irq(&policy_rwlock);
2406
2407 rc = -EFAULT;
2408 lenp = policydb.p_bools.nprim;
2409 if (len != lenp)
2410 goto out;
2411
2412 for (i = 0; i < len; i++) {
2413 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2414 audit_log(current->audit_context, GFP_ATOMIC,
2415 AUDIT_MAC_CONFIG_CHANGE,
2416 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2417 sym_name(&policydb, SYM_BOOLS, i),
2418 !!values[i],
2419 policydb.bool_val_to_struct[i]->state,
2420 audit_get_loginuid(current),
2421 audit_get_sessionid(current));
2422 }
2423 if (values[i])
2424 policydb.bool_val_to_struct[i]->state = 1;
2425 else
2426 policydb.bool_val_to_struct[i]->state = 0;
2427 }
2428
2429 for (cur = policydb.cond_list; cur; cur = cur->next) {
2430 rc = evaluate_cond_node(&policydb, cur);
2431 if (rc)
2432 goto out;
2433 }
2434
2435 seqno = ++latest_granting;
2436 rc = 0;
2437out:
2438 write_unlock_irq(&policy_rwlock);
2439 if (!rc) {
2440 avc_ss_reset(seqno);
2441 selnl_notify_policyload(seqno);
2442 selinux_status_update_policyload(seqno);
2443 selinux_xfrm_notify_policyload();
2444 }
2445 return rc;
2446}
2447
2448int security_get_bool_value(int bool)
2449{
2450 int rc;
2451 int len;
2452
2453 read_lock(&policy_rwlock);
2454
2455 rc = -EFAULT;
2456 len = policydb.p_bools.nprim;
2457 if (bool >= len)
2458 goto out;
2459
2460 rc = policydb.bool_val_to_struct[bool]->state;
2461out:
2462 read_unlock(&policy_rwlock);
2463 return rc;
2464}
2465
2466static int security_preserve_bools(struct policydb *p)
2467{
2468 int rc, nbools = 0, *bvalues = NULL, i;
2469 char **bnames = NULL;
2470 struct cond_bool_datum *booldatum;
2471 struct cond_node *cur;
2472
2473 rc = security_get_bools(&nbools, &bnames, &bvalues);
2474 if (rc)
2475 goto out;
2476 for (i = 0; i < nbools; i++) {
2477 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2478 if (booldatum)
2479 booldatum->state = bvalues[i];
2480 }
2481 for (cur = p->cond_list; cur; cur = cur->next) {
2482 rc = evaluate_cond_node(p, cur);
2483 if (rc)
2484 goto out;
2485 }
2486
2487out:
2488 if (bnames) {
2489 for (i = 0; i < nbools; i++)
2490 kfree(bnames[i]);
2491 }
2492 kfree(bnames);
2493 kfree(bvalues);
2494 return rc;
2495}
2496
2497/*
2498 * security_sid_mls_copy() - computes a new sid based on the given
2499 * sid and the mls portion of mls_sid.
2500 */
2501int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2502{
2503 struct context *context1;
2504 struct context *context2;
2505 struct context newcon;
2506 char *s;
2507 u32 len;
2508 int rc;
2509
2510 rc = 0;
2511 if (!ss_initialized || !policydb.mls_enabled) {
2512 *new_sid = sid;
2513 goto out;
2514 }
2515
2516 context_init(&newcon);
2517
2518 read_lock(&policy_rwlock);
2519
2520 rc = -EINVAL;
2521 context1 = sidtab_search(&sidtab, sid);
2522 if (!context1) {
2523 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2524 __func__, sid);
2525 goto out_unlock;
2526 }
2527
2528 rc = -EINVAL;
2529 context2 = sidtab_search(&sidtab, mls_sid);
2530 if (!context2) {
2531 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2532 __func__, mls_sid);
2533 goto out_unlock;
2534 }
2535
2536 newcon.user = context1->user;
2537 newcon.role = context1->role;
2538 newcon.type = context1->type;
2539 rc = mls_context_cpy(&newcon, context2);
2540 if (rc)
2541 goto out_unlock;
2542
2543 /* Check the validity of the new context. */
2544 if (!policydb_context_isvalid(&policydb, &newcon)) {
2545 rc = convert_context_handle_invalid_context(&newcon);
2546 if (rc) {
2547 if (!context_struct_to_string(&newcon, &s, &len)) {
2548 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2549 "security_sid_mls_copy: invalid context %s", s);
2550 kfree(s);
2551 }
2552 goto out_unlock;
2553 }
2554 }
2555
2556 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2557out_unlock:
2558 read_unlock(&policy_rwlock);
2559 context_destroy(&newcon);
2560out:
2561 return rc;
2562}
2563
2564/**
2565 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2566 * @nlbl_sid: NetLabel SID
2567 * @nlbl_type: NetLabel labeling protocol type
2568 * @xfrm_sid: XFRM SID
2569 *
2570 * Description:
2571 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2572 * resolved into a single SID it is returned via @peer_sid and the function
2573 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2574 * returns a negative value. A table summarizing the behavior is below:
2575 *
2576 * | function return | @sid
2577 * ------------------------------+-----------------+-----------------
2578 * no peer labels | 0 | SECSID_NULL
2579 * single peer label | 0 | <peer_label>
2580 * multiple, consistent labels | 0 | <peer_label>
2581 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2582 *
2583 */
2584int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2585 u32 xfrm_sid,
2586 u32 *peer_sid)
2587{
2588 int rc;
2589 struct context *nlbl_ctx;
2590 struct context *xfrm_ctx;
2591
2592 *peer_sid = SECSID_NULL;
2593
2594 /* handle the common (which also happens to be the set of easy) cases
2595 * right away, these two if statements catch everything involving a
2596 * single or absent peer SID/label */
2597 if (xfrm_sid == SECSID_NULL) {
2598 *peer_sid = nlbl_sid;
2599 return 0;
2600 }
2601 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2602 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2603 * is present */
2604 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2605 *peer_sid = xfrm_sid;
2606 return 0;
2607 }
2608
2609 /* we don't need to check ss_initialized here since the only way both
2610 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2611 * security server was initialized and ss_initialized was true */
2612 if (!policydb.mls_enabled)
2613 return 0;
2614
2615 read_lock(&policy_rwlock);
2616
2617 rc = -EINVAL;
2618 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2619 if (!nlbl_ctx) {
2620 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2621 __func__, nlbl_sid);
2622 goto out;
2623 }
2624 rc = -EINVAL;
2625 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2626 if (!xfrm_ctx) {
2627 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2628 __func__, xfrm_sid);
2629 goto out;
2630 }
2631 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2632 if (rc)
2633 goto out;
2634
2635 /* at present NetLabel SIDs/labels really only carry MLS
2636 * information so if the MLS portion of the NetLabel SID
2637 * matches the MLS portion of the labeled XFRM SID/label
2638 * then pass along the XFRM SID as it is the most
2639 * expressive */
2640 *peer_sid = xfrm_sid;
2641out:
2642 read_unlock(&policy_rwlock);
2643 return rc;
2644}
2645
2646static int get_classes_callback(void *k, void *d, void *args)
2647{
2648 struct class_datum *datum = d;
2649 char *name = k, **classes = args;
2650 int value = datum->value - 1;
2651
2652 classes[value] = kstrdup(name, GFP_ATOMIC);
2653 if (!classes[value])
2654 return -ENOMEM;
2655
2656 return 0;
2657}
2658
2659int security_get_classes(char ***classes, int *nclasses)
2660{
2661 int rc;
2662
2663 read_lock(&policy_rwlock);
2664
2665 rc = -ENOMEM;
2666 *nclasses = policydb.p_classes.nprim;
2667 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2668 if (!*classes)
2669 goto out;
2670
2671 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2672 *classes);
2673 if (rc) {
2674 int i;
2675 for (i = 0; i < *nclasses; i++)
2676 kfree((*classes)[i]);
2677 kfree(*classes);
2678 }
2679
2680out:
2681 read_unlock(&policy_rwlock);
2682 return rc;
2683}
2684
2685static int get_permissions_callback(void *k, void *d, void *args)
2686{
2687 struct perm_datum *datum = d;
2688 char *name = k, **perms = args;
2689 int value = datum->value - 1;
2690
2691 perms[value] = kstrdup(name, GFP_ATOMIC);
2692 if (!perms[value])
2693 return -ENOMEM;
2694
2695 return 0;
2696}
2697
2698int security_get_permissions(char *class, char ***perms, int *nperms)
2699{
2700 int rc, i;
2701 struct class_datum *match;
2702
2703 read_lock(&policy_rwlock);
2704
2705 rc = -EINVAL;
2706 match = hashtab_search(policydb.p_classes.table, class);
2707 if (!match) {
2708 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2709 __func__, class);
2710 goto out;
2711 }
2712
2713 rc = -ENOMEM;
2714 *nperms = match->permissions.nprim;
2715 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2716 if (!*perms)
2717 goto out;
2718
2719 if (match->comdatum) {
2720 rc = hashtab_map(match->comdatum->permissions.table,
2721 get_permissions_callback, *perms);
2722 if (rc)
2723 goto err;
2724 }
2725
2726 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2727 *perms);
2728 if (rc)
2729 goto err;
2730
2731out:
2732 read_unlock(&policy_rwlock);
2733 return rc;
2734
2735err:
2736 read_unlock(&policy_rwlock);
2737 for (i = 0; i < *nperms; i++)
2738 kfree((*perms)[i]);
2739 kfree(*perms);
2740 return rc;
2741}
2742
2743int security_get_reject_unknown(void)
2744{
2745 return policydb.reject_unknown;
2746}
2747
2748int security_get_allow_unknown(void)
2749{
2750 return policydb.allow_unknown;
2751}
2752
2753/**
2754 * security_policycap_supported - Check for a specific policy capability
2755 * @req_cap: capability
2756 *
2757 * Description:
2758 * This function queries the currently loaded policy to see if it supports the
2759 * capability specified by @req_cap. Returns true (1) if the capability is
2760 * supported, false (0) if it isn't supported.
2761 *
2762 */
2763int security_policycap_supported(unsigned int req_cap)
2764{
2765 int rc;
2766
2767 read_lock(&policy_rwlock);
2768 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2769 read_unlock(&policy_rwlock);
2770
2771 return rc;
2772}
2773
2774struct selinux_audit_rule {
2775 u32 au_seqno;
2776 struct context au_ctxt;
2777};
2778
2779void selinux_audit_rule_free(void *vrule)
2780{
2781 struct selinux_audit_rule *rule = vrule;
2782
2783 if (rule) {
2784 context_destroy(&rule->au_ctxt);
2785 kfree(rule);
2786 }
2787}
2788
2789int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2790{
2791 struct selinux_audit_rule *tmprule;
2792 struct role_datum *roledatum;
2793 struct type_datum *typedatum;
2794 struct user_datum *userdatum;
2795 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2796 int rc = 0;
2797
2798 *rule = NULL;
2799
2800 if (!ss_initialized)
2801 return -EOPNOTSUPP;
2802
2803 switch (field) {
2804 case AUDIT_SUBJ_USER:
2805 case AUDIT_SUBJ_ROLE:
2806 case AUDIT_SUBJ_TYPE:
2807 case AUDIT_OBJ_USER:
2808 case AUDIT_OBJ_ROLE:
2809 case AUDIT_OBJ_TYPE:
2810 /* only 'equals' and 'not equals' fit user, role, and type */
2811 if (op != Audit_equal && op != Audit_not_equal)
2812 return -EINVAL;
2813 break;
2814 case AUDIT_SUBJ_SEN:
2815 case AUDIT_SUBJ_CLR:
2816 case AUDIT_OBJ_LEV_LOW:
2817 case AUDIT_OBJ_LEV_HIGH:
2818 /* we do not allow a range, indicated by the presence of '-' */
2819 if (strchr(rulestr, '-'))
2820 return -EINVAL;
2821 break;
2822 default:
2823 /* only the above fields are valid */
2824 return -EINVAL;
2825 }
2826
2827 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2828 if (!tmprule)
2829 return -ENOMEM;
2830
2831 context_init(&tmprule->au_ctxt);
2832
2833 read_lock(&policy_rwlock);
2834
2835 tmprule->au_seqno = latest_granting;
2836
2837 switch (field) {
2838 case AUDIT_SUBJ_USER:
2839 case AUDIT_OBJ_USER:
2840 rc = -EINVAL;
2841 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2842 if (!userdatum)
2843 goto out;
2844 tmprule->au_ctxt.user = userdatum->value;
2845 break;
2846 case AUDIT_SUBJ_ROLE:
2847 case AUDIT_OBJ_ROLE:
2848 rc = -EINVAL;
2849 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2850 if (!roledatum)
2851 goto out;
2852 tmprule->au_ctxt.role = roledatum->value;
2853 break;
2854 case AUDIT_SUBJ_TYPE:
2855 case AUDIT_OBJ_TYPE:
2856 rc = -EINVAL;
2857 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2858 if (!typedatum)
2859 goto out;
2860 tmprule->au_ctxt.type = typedatum->value;
2861 break;
2862 case AUDIT_SUBJ_SEN:
2863 case AUDIT_SUBJ_CLR:
2864 case AUDIT_OBJ_LEV_LOW:
2865 case AUDIT_OBJ_LEV_HIGH:
2866 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2867 if (rc)
2868 goto out;
2869 break;
2870 }
2871 rc = 0;
2872out:
2873 read_unlock(&policy_rwlock);
2874
2875 if (rc) {
2876 selinux_audit_rule_free(tmprule);
2877 tmprule = NULL;
2878 }
2879
2880 *rule = tmprule;
2881
2882 return rc;
2883}
2884
2885/* Check to see if the rule contains any selinux fields */
2886int selinux_audit_rule_known(struct audit_krule *rule)
2887{
2888 int i;
2889
2890 for (i = 0; i < rule->field_count; i++) {
2891 struct audit_field *f = &rule->fields[i];
2892 switch (f->type) {
2893 case AUDIT_SUBJ_USER:
2894 case AUDIT_SUBJ_ROLE:
2895 case AUDIT_SUBJ_TYPE:
2896 case AUDIT_SUBJ_SEN:
2897 case AUDIT_SUBJ_CLR:
2898 case AUDIT_OBJ_USER:
2899 case AUDIT_OBJ_ROLE:
2900 case AUDIT_OBJ_TYPE:
2901 case AUDIT_OBJ_LEV_LOW:
2902 case AUDIT_OBJ_LEV_HIGH:
2903 return 1;
2904 }
2905 }
2906
2907 return 0;
2908}
2909
2910int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2911 struct audit_context *actx)
2912{
2913 struct context *ctxt;
2914 struct mls_level *level;
2915 struct selinux_audit_rule *rule = vrule;
2916 int match = 0;
2917
2918 if (!rule) {
2919 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2920 "selinux_audit_rule_match: missing rule\n");
2921 return -ENOENT;
2922 }
2923
2924 read_lock(&policy_rwlock);
2925
2926 if (rule->au_seqno < latest_granting) {
2927 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2928 "selinux_audit_rule_match: stale rule\n");
2929 match = -ESTALE;
2930 goto out;
2931 }
2932
2933 ctxt = sidtab_search(&sidtab, sid);
2934 if (!ctxt) {
2935 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2936 "selinux_audit_rule_match: unrecognized SID %d\n",
2937 sid);
2938 match = -ENOENT;
2939 goto out;
2940 }
2941
2942 /* a field/op pair that is not caught here will simply fall through
2943 without a match */
2944 switch (field) {
2945 case AUDIT_SUBJ_USER:
2946 case AUDIT_OBJ_USER:
2947 switch (op) {
2948 case Audit_equal:
2949 match = (ctxt->user == rule->au_ctxt.user);
2950 break;
2951 case Audit_not_equal:
2952 match = (ctxt->user != rule->au_ctxt.user);
2953 break;
2954 }
2955 break;
2956 case AUDIT_SUBJ_ROLE:
2957 case AUDIT_OBJ_ROLE:
2958 switch (op) {
2959 case Audit_equal:
2960 match = (ctxt->role == rule->au_ctxt.role);
2961 break;
2962 case Audit_not_equal:
2963 match = (ctxt->role != rule->au_ctxt.role);
2964 break;
2965 }
2966 break;
2967 case AUDIT_SUBJ_TYPE:
2968 case AUDIT_OBJ_TYPE:
2969 switch (op) {
2970 case Audit_equal:
2971 match = (ctxt->type == rule->au_ctxt.type);
2972 break;
2973 case Audit_not_equal:
2974 match = (ctxt->type != rule->au_ctxt.type);
2975 break;
2976 }
2977 break;
2978 case AUDIT_SUBJ_SEN:
2979 case AUDIT_SUBJ_CLR:
2980 case AUDIT_OBJ_LEV_LOW:
2981 case AUDIT_OBJ_LEV_HIGH:
2982 level = ((field == AUDIT_SUBJ_SEN ||
2983 field == AUDIT_OBJ_LEV_LOW) ?
2984 &ctxt->range.level[0] : &ctxt->range.level[1]);
2985 switch (op) {
2986 case Audit_equal:
2987 match = mls_level_eq(&rule->au_ctxt.range.level[0],
2988 level);
2989 break;
2990 case Audit_not_equal:
2991 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2992 level);
2993 break;
2994 case Audit_lt:
2995 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2996 level) &&
2997 !mls_level_eq(&rule->au_ctxt.range.level[0],
2998 level));
2999 break;
3000 case Audit_le:
3001 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3002 level);
3003 break;
3004 case Audit_gt:
3005 match = (mls_level_dom(level,
3006 &rule->au_ctxt.range.level[0]) &&
3007 !mls_level_eq(level,
3008 &rule->au_ctxt.range.level[0]));
3009 break;
3010 case Audit_ge:
3011 match = mls_level_dom(level,
3012 &rule->au_ctxt.range.level[0]);
3013 break;
3014 }
3015 }
3016
3017out:
3018 read_unlock(&policy_rwlock);
3019 return match;
3020}
3021
3022static int (*aurule_callback)(void) = audit_update_lsm_rules;
3023
3024static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
3025 u16 class, u32 perms, u32 *retained)
3026{
3027 int err = 0;
3028
3029 if (event == AVC_CALLBACK_RESET && aurule_callback)
3030 err = aurule_callback();
3031 return err;
3032}
3033
3034static int __init aurule_init(void)
3035{
3036 int err;
3037
3038 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
3039 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
3040 if (err)
3041 panic("avc_add_callback() failed, error %d\n", err);
3042
3043 return err;
3044}
3045__initcall(aurule_init);
3046
3047#ifdef CONFIG_NETLABEL
3048/**
3049 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3050 * @secattr: the NetLabel packet security attributes
3051 * @sid: the SELinux SID
3052 *
3053 * Description:
3054 * Attempt to cache the context in @ctx, which was derived from the packet in
3055 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3056 * already been initialized.
3057 *
3058 */
3059static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3060 u32 sid)
3061{
3062 u32 *sid_cache;
3063
3064 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3065 if (sid_cache == NULL)
3066 return;
3067 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3068 if (secattr->cache == NULL) {
3069 kfree(sid_cache);
3070 return;
3071 }
3072
3073 *sid_cache = sid;
3074 secattr->cache->free = kfree;
3075 secattr->cache->data = sid_cache;
3076 secattr->flags |= NETLBL_SECATTR_CACHE;
3077}
3078
3079/**
3080 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3081 * @secattr: the NetLabel packet security attributes
3082 * @sid: the SELinux SID
3083 *
3084 * Description:
3085 * Convert the given NetLabel security attributes in @secattr into a
3086 * SELinux SID. If the @secattr field does not contain a full SELinux
3087 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3088 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3089 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3090 * conversion for future lookups. Returns zero on success, negative values on
3091 * failure.
3092 *
3093 */
3094int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3095 u32 *sid)
3096{
3097 int rc;
3098 struct context *ctx;
3099 struct context ctx_new;
3100
3101 if (!ss_initialized) {
3102 *sid = SECSID_NULL;
3103 return 0;
3104 }
3105
3106 read_lock(&policy_rwlock);
3107
3108 if (secattr->flags & NETLBL_SECATTR_CACHE)
3109 *sid = *(u32 *)secattr->cache->data;
3110 else if (secattr->flags & NETLBL_SECATTR_SECID)
3111 *sid = secattr->attr.secid;
3112 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3113 rc = -EIDRM;
3114 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3115 if (ctx == NULL)
3116 goto out;
3117
3118 context_init(&ctx_new);
3119 ctx_new.user = ctx->user;
3120 ctx_new.role = ctx->role;
3121 ctx_new.type = ctx->type;
3122 mls_import_netlbl_lvl(&ctx_new, secattr);
3123 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3124 rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3125 secattr->attr.mls.cat);
3126 if (rc)
3127 goto out;
3128 memcpy(&ctx_new.range.level[1].cat,
3129 &ctx_new.range.level[0].cat,
3130 sizeof(ctx_new.range.level[0].cat));
3131 }
3132 rc = -EIDRM;
3133 if (!mls_context_isvalid(&policydb, &ctx_new))
3134 goto out_free;
3135
3136 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3137 if (rc)
3138 goto out_free;
3139
3140 security_netlbl_cache_add(secattr, *sid);
3141
3142 ebitmap_destroy(&ctx_new.range.level[0].cat);
3143 } else
3144 *sid = SECSID_NULL;
3145
3146 read_unlock(&policy_rwlock);
3147 return 0;
3148out_free:
3149 ebitmap_destroy(&ctx_new.range.level[0].cat);
3150out:
3151 read_unlock(&policy_rwlock);
3152 return rc;
3153}
3154
3155/**
3156 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3157 * @sid: the SELinux SID
3158 * @secattr: the NetLabel packet security attributes
3159 *
3160 * Description:
3161 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3162 * Returns zero on success, negative values on failure.
3163 *
3164 */
3165int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3166{
3167 int rc;
3168 struct context *ctx;
3169
3170 if (!ss_initialized)
3171 return 0;
3172
3173 read_lock(&policy_rwlock);
3174
3175 rc = -ENOENT;
3176 ctx = sidtab_search(&sidtab, sid);
3177 if (ctx == NULL)
3178 goto out;
3179
3180 rc = -ENOMEM;
3181 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3182 GFP_ATOMIC);
3183 if (secattr->domain == NULL)
3184 goto out;
3185
3186 secattr->attr.secid = sid;
3187 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3188 mls_export_netlbl_lvl(ctx, secattr);
3189 rc = mls_export_netlbl_cat(ctx, secattr);
3190out:
3191 read_unlock(&policy_rwlock);
3192 return rc;
3193}
3194#endif /* CONFIG_NETLABEL */
3195
3196/**
3197 * security_read_policy - read the policy.
3198 * @data: binary policy data
3199 * @len: length of data in bytes
3200 *
3201 */
3202int security_read_policy(void **data, size_t *len)
3203{
3204 int rc;
3205 struct policy_file fp;
3206
3207 if (!ss_initialized)
3208 return -EINVAL;
3209
3210 *len = security_policydb_len();
3211
3212 *data = vmalloc_user(*len);
3213 if (!*data)
3214 return -ENOMEM;
3215
3216 fp.data = *data;
3217 fp.len = *len;
3218
3219 read_lock(&policy_rwlock);
3220 rc = policydb_write(&policydb, &fp);
3221 read_unlock(&policy_rwlock);
3222
3223 if (rc)
3224 return rc;
3225
3226 *len = (unsigned long)fp.data - (unsigned long)*data;
3227 return 0;
3228
3229}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Implementation of the security services.
4 *
5 * Authors : Stephen Smalley, <stephen.smalley.work@gmail.com>
6 * James Morris <jmorris@redhat.com>
7 *
8 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
9 *
10 * Support for enhanced MLS infrastructure.
11 * Support for context based audit filters.
12 *
13 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
14 *
15 * Added conditional policy language extensions
16 *
17 * Updated: Hewlett-Packard <paul@paul-moore.com>
18 *
19 * Added support for NetLabel
20 * Added support for the policy capability bitmap
21 *
22 * Updated: Chad Sellers <csellers@tresys.com>
23 *
24 * Added validation of kernel classes and permissions
25 *
26 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
27 *
28 * Added support for bounds domain and audit messaged on masked permissions
29 *
30 * Updated: Guido Trentalancia <guido@trentalancia.com>
31 *
32 * Added support for runtime switching of the policy type
33 *
34 * Copyright (C) 2008, 2009 NEC Corporation
35 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
36 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
37 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
38 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
39 */
40#include <linux/kernel.h>
41#include <linux/slab.h>
42#include <linux/string.h>
43#include <linux/spinlock.h>
44#include <linux/rcupdate.h>
45#include <linux/errno.h>
46#include <linux/in.h>
47#include <linux/sched.h>
48#include <linux/audit.h>
49#include <linux/vmalloc.h>
50#include <linux/lsm_hooks.h>
51#include <net/netlabel.h>
52
53#include "flask.h"
54#include "avc.h"
55#include "avc_ss.h"
56#include "security.h"
57#include "context.h"
58#include "policydb.h"
59#include "sidtab.h"
60#include "services.h"
61#include "conditional.h"
62#include "mls.h"
63#include "objsec.h"
64#include "netlabel.h"
65#include "xfrm.h"
66#include "ebitmap.h"
67#include "audit.h"
68#include "policycap_names.h"
69#include "ima.h"
70
71struct selinux_policy_convert_data {
72 struct convert_context_args args;
73 struct sidtab_convert_params sidtab_params;
74};
75
76/* Forward declaration. */
77static int context_struct_to_string(struct policydb *policydb,
78 struct context *context,
79 char **scontext,
80 u32 *scontext_len);
81
82static int sidtab_entry_to_string(struct policydb *policydb,
83 struct sidtab *sidtab,
84 struct sidtab_entry *entry,
85 char **scontext,
86 u32 *scontext_len);
87
88static void context_struct_compute_av(struct policydb *policydb,
89 struct context *scontext,
90 struct context *tcontext,
91 u16 tclass,
92 struct av_decision *avd,
93 struct extended_perms *xperms);
94
95static int selinux_set_mapping(struct policydb *pol,
96 const struct security_class_mapping *map,
97 struct selinux_map *out_map)
98{
99 u16 i, j;
100 bool print_unknown_handle = false;
101
102 /* Find number of classes in the input mapping */
103 if (!map)
104 return -EINVAL;
105 i = 0;
106 while (map[i].name)
107 i++;
108
109 /* Allocate space for the class records, plus one for class zero */
110 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
111 if (!out_map->mapping)
112 return -ENOMEM;
113
114 /* Store the raw class and permission values */
115 j = 0;
116 while (map[j].name) {
117 const struct security_class_mapping *p_in = map + (j++);
118 struct selinux_mapping *p_out = out_map->mapping + j;
119 u16 k;
120
121 /* An empty class string skips ahead */
122 if (!strcmp(p_in->name, "")) {
123 p_out->num_perms = 0;
124 continue;
125 }
126
127 p_out->value = string_to_security_class(pol, p_in->name);
128 if (!p_out->value) {
129 pr_info("SELinux: Class %s not defined in policy.\n",
130 p_in->name);
131 if (pol->reject_unknown)
132 goto err;
133 p_out->num_perms = 0;
134 print_unknown_handle = true;
135 continue;
136 }
137
138 k = 0;
139 while (p_in->perms[k]) {
140 /* An empty permission string skips ahead */
141 if (!*p_in->perms[k]) {
142 k++;
143 continue;
144 }
145 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
146 p_in->perms[k]);
147 if (!p_out->perms[k]) {
148 pr_info("SELinux: Permission %s in class %s not defined in policy.\n",
149 p_in->perms[k], p_in->name);
150 if (pol->reject_unknown)
151 goto err;
152 print_unknown_handle = true;
153 }
154
155 k++;
156 }
157 p_out->num_perms = k;
158 }
159
160 if (print_unknown_handle)
161 pr_info("SELinux: the above unknown classes and permissions will be %s\n",
162 pol->allow_unknown ? "allowed" : "denied");
163
164 out_map->size = i;
165 return 0;
166err:
167 kfree(out_map->mapping);
168 out_map->mapping = NULL;
169 return -EINVAL;
170}
171
172/*
173 * Get real, policy values from mapped values
174 */
175
176static u16 unmap_class(struct selinux_map *map, u16 tclass)
177{
178 if (tclass < map->size)
179 return map->mapping[tclass].value;
180
181 return tclass;
182}
183
184/*
185 * Get kernel value for class from its policy value
186 */
187static u16 map_class(struct selinux_map *map, u16 pol_value)
188{
189 u16 i;
190
191 for (i = 1; i < map->size; i++) {
192 if (map->mapping[i].value == pol_value)
193 return i;
194 }
195
196 return SECCLASS_NULL;
197}
198
199static void map_decision(struct selinux_map *map,
200 u16 tclass, struct av_decision *avd,
201 int allow_unknown)
202{
203 if (tclass < map->size) {
204 struct selinux_mapping *mapping = &map->mapping[tclass];
205 unsigned int i, n = mapping->num_perms;
206 u32 result;
207
208 for (i = 0, result = 0; i < n; i++) {
209 if (avd->allowed & mapping->perms[i])
210 result |= (u32)1<<i;
211 if (allow_unknown && !mapping->perms[i])
212 result |= (u32)1<<i;
213 }
214 avd->allowed = result;
215
216 for (i = 0, result = 0; i < n; i++)
217 if (avd->auditallow & mapping->perms[i])
218 result |= (u32)1<<i;
219 avd->auditallow = result;
220
221 for (i = 0, result = 0; i < n; i++) {
222 if (avd->auditdeny & mapping->perms[i])
223 result |= (u32)1<<i;
224 if (!allow_unknown && !mapping->perms[i])
225 result |= (u32)1<<i;
226 }
227 /*
228 * In case the kernel has a bug and requests a permission
229 * between num_perms and the maximum permission number, we
230 * should audit that denial
231 */
232 for (; i < (sizeof(u32)*8); i++)
233 result |= (u32)1<<i;
234 avd->auditdeny = result;
235 }
236}
237
238int security_mls_enabled(void)
239{
240 int mls_enabled;
241 struct selinux_policy *policy;
242
243 if (!selinux_initialized())
244 return 0;
245
246 rcu_read_lock();
247 policy = rcu_dereference(selinux_state.policy);
248 mls_enabled = policy->policydb.mls_enabled;
249 rcu_read_unlock();
250 return mls_enabled;
251}
252
253/*
254 * Return the boolean value of a constraint expression
255 * when it is applied to the specified source and target
256 * security contexts.
257 *
258 * xcontext is a special beast... It is used by the validatetrans rules
259 * only. For these rules, scontext is the context before the transition,
260 * tcontext is the context after the transition, and xcontext is the context
261 * of the process performing the transition. All other callers of
262 * constraint_expr_eval should pass in NULL for xcontext.
263 */
264static int constraint_expr_eval(struct policydb *policydb,
265 struct context *scontext,
266 struct context *tcontext,
267 struct context *xcontext,
268 struct constraint_expr *cexpr)
269{
270 u32 val1, val2;
271 struct context *c;
272 struct role_datum *r1, *r2;
273 struct mls_level *l1, *l2;
274 struct constraint_expr *e;
275 int s[CEXPR_MAXDEPTH];
276 int sp = -1;
277
278 for (e = cexpr; e; e = e->next) {
279 switch (e->expr_type) {
280 case CEXPR_NOT:
281 BUG_ON(sp < 0);
282 s[sp] = !s[sp];
283 break;
284 case CEXPR_AND:
285 BUG_ON(sp < 1);
286 sp--;
287 s[sp] &= s[sp + 1];
288 break;
289 case CEXPR_OR:
290 BUG_ON(sp < 1);
291 sp--;
292 s[sp] |= s[sp + 1];
293 break;
294 case CEXPR_ATTR:
295 if (sp == (CEXPR_MAXDEPTH - 1))
296 return 0;
297 switch (e->attr) {
298 case CEXPR_USER:
299 val1 = scontext->user;
300 val2 = tcontext->user;
301 break;
302 case CEXPR_TYPE:
303 val1 = scontext->type;
304 val2 = tcontext->type;
305 break;
306 case CEXPR_ROLE:
307 val1 = scontext->role;
308 val2 = tcontext->role;
309 r1 = policydb->role_val_to_struct[val1 - 1];
310 r2 = policydb->role_val_to_struct[val2 - 1];
311 switch (e->op) {
312 case CEXPR_DOM:
313 s[++sp] = ebitmap_get_bit(&r1->dominates,
314 val2 - 1);
315 continue;
316 case CEXPR_DOMBY:
317 s[++sp] = ebitmap_get_bit(&r2->dominates,
318 val1 - 1);
319 continue;
320 case CEXPR_INCOMP:
321 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
322 val2 - 1) &&
323 !ebitmap_get_bit(&r2->dominates,
324 val1 - 1));
325 continue;
326 default:
327 break;
328 }
329 break;
330 case CEXPR_L1L2:
331 l1 = &(scontext->range.level[0]);
332 l2 = &(tcontext->range.level[0]);
333 goto mls_ops;
334 case CEXPR_L1H2:
335 l1 = &(scontext->range.level[0]);
336 l2 = &(tcontext->range.level[1]);
337 goto mls_ops;
338 case CEXPR_H1L2:
339 l1 = &(scontext->range.level[1]);
340 l2 = &(tcontext->range.level[0]);
341 goto mls_ops;
342 case CEXPR_H1H2:
343 l1 = &(scontext->range.level[1]);
344 l2 = &(tcontext->range.level[1]);
345 goto mls_ops;
346 case CEXPR_L1H1:
347 l1 = &(scontext->range.level[0]);
348 l2 = &(scontext->range.level[1]);
349 goto mls_ops;
350 case CEXPR_L2H2:
351 l1 = &(tcontext->range.level[0]);
352 l2 = &(tcontext->range.level[1]);
353 goto mls_ops;
354mls_ops:
355 switch (e->op) {
356 case CEXPR_EQ:
357 s[++sp] = mls_level_eq(l1, l2);
358 continue;
359 case CEXPR_NEQ:
360 s[++sp] = !mls_level_eq(l1, l2);
361 continue;
362 case CEXPR_DOM:
363 s[++sp] = mls_level_dom(l1, l2);
364 continue;
365 case CEXPR_DOMBY:
366 s[++sp] = mls_level_dom(l2, l1);
367 continue;
368 case CEXPR_INCOMP:
369 s[++sp] = mls_level_incomp(l2, l1);
370 continue;
371 default:
372 BUG();
373 return 0;
374 }
375 break;
376 default:
377 BUG();
378 return 0;
379 }
380
381 switch (e->op) {
382 case CEXPR_EQ:
383 s[++sp] = (val1 == val2);
384 break;
385 case CEXPR_NEQ:
386 s[++sp] = (val1 != val2);
387 break;
388 default:
389 BUG();
390 return 0;
391 }
392 break;
393 case CEXPR_NAMES:
394 if (sp == (CEXPR_MAXDEPTH-1))
395 return 0;
396 c = scontext;
397 if (e->attr & CEXPR_TARGET)
398 c = tcontext;
399 else if (e->attr & CEXPR_XTARGET) {
400 c = xcontext;
401 if (!c) {
402 BUG();
403 return 0;
404 }
405 }
406 if (e->attr & CEXPR_USER)
407 val1 = c->user;
408 else if (e->attr & CEXPR_ROLE)
409 val1 = c->role;
410 else if (e->attr & CEXPR_TYPE)
411 val1 = c->type;
412 else {
413 BUG();
414 return 0;
415 }
416
417 switch (e->op) {
418 case CEXPR_EQ:
419 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
420 break;
421 case CEXPR_NEQ:
422 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
423 break;
424 default:
425 BUG();
426 return 0;
427 }
428 break;
429 default:
430 BUG();
431 return 0;
432 }
433 }
434
435 BUG_ON(sp != 0);
436 return s[0];
437}
438
439/*
440 * security_dump_masked_av - dumps masked permissions during
441 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
442 */
443static int dump_masked_av_helper(void *k, void *d, void *args)
444{
445 struct perm_datum *pdatum = d;
446 char **permission_names = args;
447
448 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
449
450 permission_names[pdatum->value - 1] = (char *)k;
451
452 return 0;
453}
454
455static void security_dump_masked_av(struct policydb *policydb,
456 struct context *scontext,
457 struct context *tcontext,
458 u16 tclass,
459 u32 permissions,
460 const char *reason)
461{
462 struct common_datum *common_dat;
463 struct class_datum *tclass_dat;
464 struct audit_buffer *ab;
465 char *tclass_name;
466 char *scontext_name = NULL;
467 char *tcontext_name = NULL;
468 char *permission_names[32];
469 int index;
470 u32 length;
471 bool need_comma = false;
472
473 if (!permissions)
474 return;
475
476 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
477 tclass_dat = policydb->class_val_to_struct[tclass - 1];
478 common_dat = tclass_dat->comdatum;
479
480 /* init permission_names */
481 if (common_dat &&
482 hashtab_map(&common_dat->permissions.table,
483 dump_masked_av_helper, permission_names) < 0)
484 goto out;
485
486 if (hashtab_map(&tclass_dat->permissions.table,
487 dump_masked_av_helper, permission_names) < 0)
488 goto out;
489
490 /* get scontext/tcontext in text form */
491 if (context_struct_to_string(policydb, scontext,
492 &scontext_name, &length) < 0)
493 goto out;
494
495 if (context_struct_to_string(policydb, tcontext,
496 &tcontext_name, &length) < 0)
497 goto out;
498
499 /* audit a message */
500 ab = audit_log_start(audit_context(),
501 GFP_ATOMIC, AUDIT_SELINUX_ERR);
502 if (!ab)
503 goto out;
504
505 audit_log_format(ab, "op=security_compute_av reason=%s "
506 "scontext=%s tcontext=%s tclass=%s perms=",
507 reason, scontext_name, tcontext_name, tclass_name);
508
509 for (index = 0; index < 32; index++) {
510 u32 mask = (1 << index);
511
512 if ((mask & permissions) == 0)
513 continue;
514
515 audit_log_format(ab, "%s%s",
516 need_comma ? "," : "",
517 permission_names[index]
518 ? permission_names[index] : "????");
519 need_comma = true;
520 }
521 audit_log_end(ab);
522out:
523 /* release scontext/tcontext */
524 kfree(tcontext_name);
525 kfree(scontext_name);
526}
527
528/*
529 * security_boundary_permission - drops violated permissions
530 * on boundary constraint.
531 */
532static void type_attribute_bounds_av(struct policydb *policydb,
533 struct context *scontext,
534 struct context *tcontext,
535 u16 tclass,
536 struct av_decision *avd)
537{
538 struct context lo_scontext;
539 struct context lo_tcontext, *tcontextp = tcontext;
540 struct av_decision lo_avd;
541 struct type_datum *source;
542 struct type_datum *target;
543 u32 masked = 0;
544
545 source = policydb->type_val_to_struct[scontext->type - 1];
546 BUG_ON(!source);
547
548 if (!source->bounds)
549 return;
550
551 target = policydb->type_val_to_struct[tcontext->type - 1];
552 BUG_ON(!target);
553
554 memset(&lo_avd, 0, sizeof(lo_avd));
555
556 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
557 lo_scontext.type = source->bounds;
558
559 if (target->bounds) {
560 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
561 lo_tcontext.type = target->bounds;
562 tcontextp = &lo_tcontext;
563 }
564
565 context_struct_compute_av(policydb, &lo_scontext,
566 tcontextp,
567 tclass,
568 &lo_avd,
569 NULL);
570
571 masked = ~lo_avd.allowed & avd->allowed;
572
573 if (likely(!masked))
574 return; /* no masked permission */
575
576 /* mask violated permissions */
577 avd->allowed &= ~masked;
578
579 /* audit masked permissions */
580 security_dump_masked_av(policydb, scontext, tcontext,
581 tclass, masked, "bounds");
582}
583
584/*
585 * flag which drivers have permissions
586 * only looking for ioctl based extended permissions
587 */
588void services_compute_xperms_drivers(
589 struct extended_perms *xperms,
590 struct avtab_node *node)
591{
592 unsigned int i;
593
594 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
595 /* if one or more driver has all permissions allowed */
596 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
597 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
598 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
599 /* if allowing permissions within a driver */
600 security_xperm_set(xperms->drivers.p,
601 node->datum.u.xperms->driver);
602 }
603
604 xperms->len = 1;
605}
606
607/*
608 * Compute access vectors and extended permissions based on a context
609 * structure pair for the permissions in a particular class.
610 */
611static void context_struct_compute_av(struct policydb *policydb,
612 struct context *scontext,
613 struct context *tcontext,
614 u16 tclass,
615 struct av_decision *avd,
616 struct extended_perms *xperms)
617{
618 struct constraint_node *constraint;
619 struct role_allow *ra;
620 struct avtab_key avkey;
621 struct avtab_node *node;
622 struct class_datum *tclass_datum;
623 struct ebitmap *sattr, *tattr;
624 struct ebitmap_node *snode, *tnode;
625 unsigned int i, j;
626
627 avd->allowed = 0;
628 avd->auditallow = 0;
629 avd->auditdeny = 0xffffffff;
630 if (xperms) {
631 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
632 xperms->len = 0;
633 }
634
635 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
636 if (printk_ratelimit())
637 pr_warn("SELinux: Invalid class %hu\n", tclass);
638 return;
639 }
640
641 tclass_datum = policydb->class_val_to_struct[tclass - 1];
642
643 /*
644 * If a specific type enforcement rule was defined for
645 * this permission check, then use it.
646 */
647 avkey.target_class = tclass;
648 avkey.specified = AVTAB_AV | AVTAB_XPERMS;
649 sattr = &policydb->type_attr_map_array[scontext->type - 1];
650 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
651 ebitmap_for_each_positive_bit(sattr, snode, i) {
652 ebitmap_for_each_positive_bit(tattr, tnode, j) {
653 avkey.source_type = i + 1;
654 avkey.target_type = j + 1;
655 for (node = avtab_search_node(&policydb->te_avtab,
656 &avkey);
657 node;
658 node = avtab_search_node_next(node, avkey.specified)) {
659 if (node->key.specified == AVTAB_ALLOWED)
660 avd->allowed |= node->datum.u.data;
661 else if (node->key.specified == AVTAB_AUDITALLOW)
662 avd->auditallow |= node->datum.u.data;
663 else if (node->key.specified == AVTAB_AUDITDENY)
664 avd->auditdeny &= node->datum.u.data;
665 else if (xperms && (node->key.specified & AVTAB_XPERMS))
666 services_compute_xperms_drivers(xperms, node);
667 }
668
669 /* Check conditional av table for additional permissions */
670 cond_compute_av(&policydb->te_cond_avtab, &avkey,
671 avd, xperms);
672
673 }
674 }
675
676 /*
677 * Remove any permissions prohibited by a constraint (this includes
678 * the MLS policy).
679 */
680 constraint = tclass_datum->constraints;
681 while (constraint) {
682 if ((constraint->permissions & (avd->allowed)) &&
683 !constraint_expr_eval(policydb, scontext, tcontext, NULL,
684 constraint->expr)) {
685 avd->allowed &= ~(constraint->permissions);
686 }
687 constraint = constraint->next;
688 }
689
690 /*
691 * If checking process transition permission and the
692 * role is changing, then check the (current_role, new_role)
693 * pair.
694 */
695 if (tclass == policydb->process_class &&
696 (avd->allowed & policydb->process_trans_perms) &&
697 scontext->role != tcontext->role) {
698 for (ra = policydb->role_allow; ra; ra = ra->next) {
699 if (scontext->role == ra->role &&
700 tcontext->role == ra->new_role)
701 break;
702 }
703 if (!ra)
704 avd->allowed &= ~policydb->process_trans_perms;
705 }
706
707 /*
708 * If the given source and target types have boundary
709 * constraint, lazy checks have to mask any violated
710 * permission and notice it to userspace via audit.
711 */
712 type_attribute_bounds_av(policydb, scontext, tcontext,
713 tclass, avd);
714}
715
716static int security_validtrans_handle_fail(struct selinux_policy *policy,
717 struct sidtab_entry *oentry,
718 struct sidtab_entry *nentry,
719 struct sidtab_entry *tentry,
720 u16 tclass)
721{
722 struct policydb *p = &policy->policydb;
723 struct sidtab *sidtab = policy->sidtab;
724 char *o = NULL, *n = NULL, *t = NULL;
725 u32 olen, nlen, tlen;
726
727 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
728 goto out;
729 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
730 goto out;
731 if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
732 goto out;
733 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
734 "op=security_validate_transition seresult=denied"
735 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
736 o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
737out:
738 kfree(o);
739 kfree(n);
740 kfree(t);
741
742 if (!enforcing_enabled())
743 return 0;
744 return -EPERM;
745}
746
747static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
748 u16 orig_tclass, bool user)
749{
750 struct selinux_policy *policy;
751 struct policydb *policydb;
752 struct sidtab *sidtab;
753 struct sidtab_entry *oentry;
754 struct sidtab_entry *nentry;
755 struct sidtab_entry *tentry;
756 struct class_datum *tclass_datum;
757 struct constraint_node *constraint;
758 u16 tclass;
759 int rc = 0;
760
761
762 if (!selinux_initialized())
763 return 0;
764
765 rcu_read_lock();
766
767 policy = rcu_dereference(selinux_state.policy);
768 policydb = &policy->policydb;
769 sidtab = policy->sidtab;
770
771 if (!user)
772 tclass = unmap_class(&policy->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 oentry = sidtab_search_entry(sidtab, oldsid);
783 if (!oentry) {
784 pr_err("SELinux: %s: unrecognized SID %d\n",
785 __func__, oldsid);
786 rc = -EINVAL;
787 goto out;
788 }
789
790 nentry = sidtab_search_entry(sidtab, newsid);
791 if (!nentry) {
792 pr_err("SELinux: %s: unrecognized SID %d\n",
793 __func__, newsid);
794 rc = -EINVAL;
795 goto out;
796 }
797
798 tentry = sidtab_search_entry(sidtab, tasksid);
799 if (!tentry) {
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, &oentry->context,
809 &nentry->context, &tentry->context,
810 constraint->expr)) {
811 if (user)
812 rc = -EPERM;
813 else
814 rc = security_validtrans_handle_fail(policy,
815 oentry,
816 nentry,
817 tentry,
818 tclass);
819 goto out;
820 }
821 constraint = constraint->next;
822 }
823
824out:
825 rcu_read_unlock();
826 return rc;
827}
828
829int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
830 u16 tclass)
831{
832 return security_compute_validatetrans(oldsid, newsid, tasksid,
833 tclass, true);
834}
835
836int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
837 u16 orig_tclass)
838{
839 return security_compute_validatetrans(oldsid, newsid, tasksid,
840 orig_tclass, false);
841}
842
843/*
844 * security_bounded_transition - check whether the given
845 * transition is directed to bounded, or not.
846 * It returns 0, if @newsid is bounded by @oldsid.
847 * Otherwise, it returns error code.
848 *
849 * @oldsid : current security identifier
850 * @newsid : destinated security identifier
851 */
852int security_bounded_transition(u32 old_sid, u32 new_sid)
853{
854 struct selinux_policy *policy;
855 struct policydb *policydb;
856 struct sidtab *sidtab;
857 struct sidtab_entry *old_entry, *new_entry;
858 struct type_datum *type;
859 u32 index;
860 int rc;
861
862 if (!selinux_initialized())
863 return 0;
864
865 rcu_read_lock();
866 policy = rcu_dereference(selinux_state.policy);
867 policydb = &policy->policydb;
868 sidtab = policy->sidtab;
869
870 rc = -EINVAL;
871 old_entry = sidtab_search_entry(sidtab, old_sid);
872 if (!old_entry) {
873 pr_err("SELinux: %s: unrecognized SID %u\n",
874 __func__, old_sid);
875 goto out;
876 }
877
878 rc = -EINVAL;
879 new_entry = sidtab_search_entry(sidtab, new_sid);
880 if (!new_entry) {
881 pr_err("SELinux: %s: unrecognized SID %u\n",
882 __func__, new_sid);
883 goto out;
884 }
885
886 rc = 0;
887 /* type/domain unchanged */
888 if (old_entry->context.type == new_entry->context.type)
889 goto out;
890
891 index = new_entry->context.type;
892 while (true) {
893 type = policydb->type_val_to_struct[index - 1];
894 BUG_ON(!type);
895
896 /* not bounded anymore */
897 rc = -EPERM;
898 if (!type->bounds)
899 break;
900
901 /* @newsid is bounded by @oldsid */
902 rc = 0;
903 if (type->bounds == old_entry->context.type)
904 break;
905
906 index = type->bounds;
907 }
908
909 if (rc) {
910 char *old_name = NULL;
911 char *new_name = NULL;
912 u32 length;
913
914 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
915 &old_name, &length) &&
916 !sidtab_entry_to_string(policydb, sidtab, new_entry,
917 &new_name, &length)) {
918 audit_log(audit_context(),
919 GFP_ATOMIC, AUDIT_SELINUX_ERR,
920 "op=security_bounded_transition "
921 "seresult=denied "
922 "oldcontext=%s newcontext=%s",
923 old_name, new_name);
924 }
925 kfree(new_name);
926 kfree(old_name);
927 }
928out:
929 rcu_read_unlock();
930
931 return rc;
932}
933
934static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
935{
936 avd->allowed = 0;
937 avd->auditallow = 0;
938 avd->auditdeny = 0xffffffff;
939 if (policy)
940 avd->seqno = policy->latest_granting;
941 else
942 avd->seqno = 0;
943 avd->flags = 0;
944}
945
946void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
947 struct avtab_node *node)
948{
949 unsigned int i;
950
951 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
952 if (xpermd->driver != node->datum.u.xperms->driver)
953 return;
954 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
955 if (!security_xperm_test(node->datum.u.xperms->perms.p,
956 xpermd->driver))
957 return;
958 } else {
959 BUG();
960 }
961
962 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
963 xpermd->used |= XPERMS_ALLOWED;
964 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
965 memset(xpermd->allowed->p, 0xff,
966 sizeof(xpermd->allowed->p));
967 }
968 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
969 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
970 xpermd->allowed->p[i] |=
971 node->datum.u.xperms->perms.p[i];
972 }
973 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
974 xpermd->used |= XPERMS_AUDITALLOW;
975 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
976 memset(xpermd->auditallow->p, 0xff,
977 sizeof(xpermd->auditallow->p));
978 }
979 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
980 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
981 xpermd->auditallow->p[i] |=
982 node->datum.u.xperms->perms.p[i];
983 }
984 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
985 xpermd->used |= XPERMS_DONTAUDIT;
986 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
987 memset(xpermd->dontaudit->p, 0xff,
988 sizeof(xpermd->dontaudit->p));
989 }
990 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
991 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
992 xpermd->dontaudit->p[i] |=
993 node->datum.u.xperms->perms.p[i];
994 }
995 } else {
996 BUG();
997 }
998}
999
1000void security_compute_xperms_decision(u32 ssid,
1001 u32 tsid,
1002 u16 orig_tclass,
1003 u8 driver,
1004 struct extended_perms_decision *xpermd)
1005{
1006 struct selinux_policy *policy;
1007 struct policydb *policydb;
1008 struct sidtab *sidtab;
1009 u16 tclass;
1010 struct context *scontext, *tcontext;
1011 struct avtab_key avkey;
1012 struct avtab_node *node;
1013 struct ebitmap *sattr, *tattr;
1014 struct ebitmap_node *snode, *tnode;
1015 unsigned int i, j;
1016
1017 xpermd->driver = driver;
1018 xpermd->used = 0;
1019 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1020 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1021 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1022
1023 rcu_read_lock();
1024 if (!selinux_initialized())
1025 goto allow;
1026
1027 policy = rcu_dereference(selinux_state.policy);
1028 policydb = &policy->policydb;
1029 sidtab = policy->sidtab;
1030
1031 scontext = sidtab_search(sidtab, ssid);
1032 if (!scontext) {
1033 pr_err("SELinux: %s: unrecognized SID %d\n",
1034 __func__, ssid);
1035 goto out;
1036 }
1037
1038 tcontext = sidtab_search(sidtab, tsid);
1039 if (!tcontext) {
1040 pr_err("SELinux: %s: unrecognized SID %d\n",
1041 __func__, tsid);
1042 goto out;
1043 }
1044
1045 tclass = unmap_class(&policy->map, orig_tclass);
1046 if (unlikely(orig_tclass && !tclass)) {
1047 if (policydb->allow_unknown)
1048 goto allow;
1049 goto out;
1050 }
1051
1052
1053 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1054 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1055 goto out;
1056 }
1057
1058 avkey.target_class = tclass;
1059 avkey.specified = AVTAB_XPERMS;
1060 sattr = &policydb->type_attr_map_array[scontext->type - 1];
1061 tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1062 ebitmap_for_each_positive_bit(sattr, snode, i) {
1063 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1064 avkey.source_type = i + 1;
1065 avkey.target_type = j + 1;
1066 for (node = avtab_search_node(&policydb->te_avtab,
1067 &avkey);
1068 node;
1069 node = avtab_search_node_next(node, avkey.specified))
1070 services_compute_xperms_decision(xpermd, node);
1071
1072 cond_compute_xperms(&policydb->te_cond_avtab,
1073 &avkey, xpermd);
1074 }
1075 }
1076out:
1077 rcu_read_unlock();
1078 return;
1079allow:
1080 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1081 goto out;
1082}
1083
1084/**
1085 * security_compute_av - Compute access vector decisions.
1086 * @ssid: source security identifier
1087 * @tsid: target security identifier
1088 * @orig_tclass: target security class
1089 * @avd: access vector decisions
1090 * @xperms: extended permissions
1091 *
1092 * Compute a set of access vector decisions based on the
1093 * SID pair (@ssid, @tsid) for the permissions in @tclass.
1094 */
1095void security_compute_av(u32 ssid,
1096 u32 tsid,
1097 u16 orig_tclass,
1098 struct av_decision *avd,
1099 struct extended_perms *xperms)
1100{
1101 struct selinux_policy *policy;
1102 struct policydb *policydb;
1103 struct sidtab *sidtab;
1104 u16 tclass;
1105 struct context *scontext = NULL, *tcontext = NULL;
1106
1107 rcu_read_lock();
1108 policy = rcu_dereference(selinux_state.policy);
1109 avd_init(policy, avd);
1110 xperms->len = 0;
1111 if (!selinux_initialized())
1112 goto allow;
1113
1114 policydb = &policy->policydb;
1115 sidtab = policy->sidtab;
1116
1117 scontext = sidtab_search(sidtab, ssid);
1118 if (!scontext) {
1119 pr_err("SELinux: %s: unrecognized SID %d\n",
1120 __func__, ssid);
1121 goto out;
1122 }
1123
1124 /* permissive domain? */
1125 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1126 avd->flags |= AVD_FLAGS_PERMISSIVE;
1127
1128 tcontext = sidtab_search(sidtab, tsid);
1129 if (!tcontext) {
1130 pr_err("SELinux: %s: unrecognized SID %d\n",
1131 __func__, tsid);
1132 goto out;
1133 }
1134
1135 tclass = unmap_class(&policy->map, orig_tclass);
1136 if (unlikely(orig_tclass && !tclass)) {
1137 if (policydb->allow_unknown)
1138 goto allow;
1139 goto out;
1140 }
1141 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1142 xperms);
1143 map_decision(&policy->map, orig_tclass, avd,
1144 policydb->allow_unknown);
1145out:
1146 rcu_read_unlock();
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 selinux_policy *policy;
1159 struct policydb *policydb;
1160 struct sidtab *sidtab;
1161 struct context *scontext = NULL, *tcontext = NULL;
1162
1163 rcu_read_lock();
1164 policy = rcu_dereference(selinux_state.policy);
1165 avd_init(policy, avd);
1166 if (!selinux_initialized())
1167 goto allow;
1168
1169 policydb = &policy->policydb;
1170 sidtab = policy->sidtab;
1171
1172 scontext = sidtab_search(sidtab, ssid);
1173 if (!scontext) {
1174 pr_err("SELinux: %s: unrecognized SID %d\n",
1175 __func__, ssid);
1176 goto out;
1177 }
1178
1179 /* permissive domain? */
1180 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1181 avd->flags |= AVD_FLAGS_PERMISSIVE;
1182
1183 tcontext = sidtab_search(sidtab, tsid);
1184 if (!tcontext) {
1185 pr_err("SELinux: %s: unrecognized SID %d\n",
1186 __func__, tsid);
1187 goto out;
1188 }
1189
1190 if (unlikely(!tclass)) {
1191 if (policydb->allow_unknown)
1192 goto allow;
1193 goto out;
1194 }
1195
1196 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1197 NULL);
1198 out:
1199 rcu_read_unlock();
1200 return;
1201allow:
1202 avd->allowed = 0xffffffff;
1203 goto out;
1204}
1205
1206/*
1207 * Write the security context string representation of
1208 * the context structure `context' into a dynamically
1209 * allocated string of the correct size. Set `*scontext'
1210 * to point to this string and set `*scontext_len' to
1211 * the length of the string.
1212 */
1213static int context_struct_to_string(struct policydb *p,
1214 struct context *context,
1215 char **scontext, u32 *scontext_len)
1216{
1217 char *scontextp;
1218
1219 if (scontext)
1220 *scontext = NULL;
1221 *scontext_len = 0;
1222
1223 if (context->len) {
1224 *scontext_len = context->len;
1225 if (scontext) {
1226 *scontext = kstrdup(context->str, GFP_ATOMIC);
1227 if (!(*scontext))
1228 return -ENOMEM;
1229 }
1230 return 0;
1231 }
1232
1233 /* Compute the size of the context. */
1234 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1235 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1236 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1237 *scontext_len += mls_compute_context_len(p, context);
1238
1239 if (!scontext)
1240 return 0;
1241
1242 /* Allocate space for the context; caller must free this space. */
1243 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1244 if (!scontextp)
1245 return -ENOMEM;
1246 *scontext = scontextp;
1247
1248 /*
1249 * Copy the user name, role name and type name into the context.
1250 */
1251 scontextp += sprintf(scontextp, "%s:%s:%s",
1252 sym_name(p, SYM_USERS, context->user - 1),
1253 sym_name(p, SYM_ROLES, context->role - 1),
1254 sym_name(p, SYM_TYPES, context->type - 1));
1255
1256 mls_sid_to_context(p, context, &scontextp);
1257
1258 *scontextp = 0;
1259
1260 return 0;
1261}
1262
1263static int sidtab_entry_to_string(struct policydb *p,
1264 struct sidtab *sidtab,
1265 struct sidtab_entry *entry,
1266 char **scontext, u32 *scontext_len)
1267{
1268 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1269
1270 if (rc != -ENOENT)
1271 return rc;
1272
1273 rc = context_struct_to_string(p, &entry->context, scontext,
1274 scontext_len);
1275 if (!rc && scontext)
1276 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1277 return rc;
1278}
1279
1280#include "initial_sid_to_string.h"
1281
1282int security_sidtab_hash_stats(char *page)
1283{
1284 struct selinux_policy *policy;
1285 int rc;
1286
1287 if (!selinux_initialized()) {
1288 pr_err("SELinux: %s: called before initial load_policy\n",
1289 __func__);
1290 return -EINVAL;
1291 }
1292
1293 rcu_read_lock();
1294 policy = rcu_dereference(selinux_state.policy);
1295 rc = sidtab_hash_stats(policy->sidtab, page);
1296 rcu_read_unlock();
1297
1298 return rc;
1299}
1300
1301const char *security_get_initial_sid_context(u32 sid)
1302{
1303 if (unlikely(sid > SECINITSID_NUM))
1304 return NULL;
1305 return initial_sid_to_string[sid];
1306}
1307
1308static int security_sid_to_context_core(u32 sid, char **scontext,
1309 u32 *scontext_len, int force,
1310 int only_invalid)
1311{
1312 struct selinux_policy *policy;
1313 struct policydb *policydb;
1314 struct sidtab *sidtab;
1315 struct sidtab_entry *entry;
1316 int rc = 0;
1317
1318 if (scontext)
1319 *scontext = NULL;
1320 *scontext_len = 0;
1321
1322 if (!selinux_initialized()) {
1323 if (sid <= SECINITSID_NUM) {
1324 char *scontextp;
1325 const char *s;
1326
1327 /*
1328 * Before the policy is loaded, translate
1329 * SECINITSID_INIT to "kernel", because systemd and
1330 * libselinux < 2.6 take a getcon_raw() result that is
1331 * both non-null and not "kernel" to mean that a policy
1332 * is already loaded.
1333 */
1334 if (sid == SECINITSID_INIT)
1335 sid = SECINITSID_KERNEL;
1336
1337 s = initial_sid_to_string[sid];
1338 if (!s)
1339 return -EINVAL;
1340 *scontext_len = strlen(s) + 1;
1341 if (!scontext)
1342 return 0;
1343 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1344 if (!scontextp)
1345 return -ENOMEM;
1346 *scontext = scontextp;
1347 return 0;
1348 }
1349 pr_err("SELinux: %s: called before initial "
1350 "load_policy on unknown SID %d\n", __func__, sid);
1351 return -EINVAL;
1352 }
1353 rcu_read_lock();
1354 policy = rcu_dereference(selinux_state.policy);
1355 policydb = &policy->policydb;
1356 sidtab = policy->sidtab;
1357
1358 if (force)
1359 entry = sidtab_search_entry_force(sidtab, sid);
1360 else
1361 entry = sidtab_search_entry(sidtab, sid);
1362 if (!entry) {
1363 pr_err("SELinux: %s: unrecognized SID %d\n",
1364 __func__, sid);
1365 rc = -EINVAL;
1366 goto out_unlock;
1367 }
1368 if (only_invalid && !entry->context.len)
1369 goto out_unlock;
1370
1371 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1372 scontext_len);
1373
1374out_unlock:
1375 rcu_read_unlock();
1376 return rc;
1377
1378}
1379
1380/**
1381 * security_sid_to_context - Obtain a context for a given SID.
1382 * @sid: security identifier, SID
1383 * @scontext: security context
1384 * @scontext_len: length in bytes
1385 *
1386 * Write the string representation of the context associated with @sid
1387 * into a dynamically allocated string of the correct size. Set @scontext
1388 * to point to this string and set @scontext_len to the length of the string.
1389 */
1390int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1391{
1392 return security_sid_to_context_core(sid, scontext,
1393 scontext_len, 0, 0);
1394}
1395
1396int security_sid_to_context_force(u32 sid,
1397 char **scontext, u32 *scontext_len)
1398{
1399 return security_sid_to_context_core(sid, scontext,
1400 scontext_len, 1, 0);
1401}
1402
1403/**
1404 * security_sid_to_context_inval - Obtain a context for a given SID if it
1405 * is invalid.
1406 * @sid: security identifier, SID
1407 * @scontext: security context
1408 * @scontext_len: length in bytes
1409 *
1410 * Write the string representation of the context associated with @sid
1411 * into a dynamically allocated string of the correct size, but only if the
1412 * context is invalid in the current policy. Set @scontext to point to
1413 * this string (or NULL if the context is valid) and set @scontext_len to
1414 * the length of the string (or 0 if the context is valid).
1415 */
1416int security_sid_to_context_inval(u32 sid,
1417 char **scontext, u32 *scontext_len)
1418{
1419 return security_sid_to_context_core(sid, scontext,
1420 scontext_len, 1, 1);
1421}
1422
1423/*
1424 * Caveat: Mutates scontext.
1425 */
1426static int string_to_context_struct(struct policydb *pol,
1427 struct sidtab *sidtabp,
1428 char *scontext,
1429 struct context *ctx,
1430 u32 def_sid)
1431{
1432 struct role_datum *role;
1433 struct type_datum *typdatum;
1434 struct user_datum *usrdatum;
1435 char *scontextp, *p, oldc;
1436 int rc = 0;
1437
1438 context_init(ctx);
1439
1440 /* Parse the security context. */
1441
1442 rc = -EINVAL;
1443 scontextp = scontext;
1444
1445 /* Extract the user. */
1446 p = scontextp;
1447 while (*p && *p != ':')
1448 p++;
1449
1450 if (*p == 0)
1451 goto out;
1452
1453 *p++ = 0;
1454
1455 usrdatum = symtab_search(&pol->p_users, scontextp);
1456 if (!usrdatum)
1457 goto out;
1458
1459 ctx->user = usrdatum->value;
1460
1461 /* Extract role. */
1462 scontextp = p;
1463 while (*p && *p != ':')
1464 p++;
1465
1466 if (*p == 0)
1467 goto out;
1468
1469 *p++ = 0;
1470
1471 role = symtab_search(&pol->p_roles, scontextp);
1472 if (!role)
1473 goto out;
1474 ctx->role = role->value;
1475
1476 /* Extract type. */
1477 scontextp = p;
1478 while (*p && *p != ':')
1479 p++;
1480 oldc = *p;
1481 *p++ = 0;
1482
1483 typdatum = symtab_search(&pol->p_types, scontextp);
1484 if (!typdatum || typdatum->attribute)
1485 goto out;
1486
1487 ctx->type = typdatum->value;
1488
1489 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1490 if (rc)
1491 goto out;
1492
1493 /* Check the validity of the new context. */
1494 rc = -EINVAL;
1495 if (!policydb_context_isvalid(pol, ctx))
1496 goto out;
1497 rc = 0;
1498out:
1499 if (rc)
1500 context_destroy(ctx);
1501 return rc;
1502}
1503
1504static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1505 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1506 int force)
1507{
1508 struct selinux_policy *policy;
1509 struct policydb *policydb;
1510 struct sidtab *sidtab;
1511 char *scontext2, *str = NULL;
1512 struct context context;
1513 int rc = 0;
1514
1515 /* An empty security context is never valid. */
1516 if (!scontext_len)
1517 return -EINVAL;
1518
1519 /* Copy the string to allow changes and ensure a NUL terminator */
1520 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1521 if (!scontext2)
1522 return -ENOMEM;
1523
1524 if (!selinux_initialized()) {
1525 u32 i;
1526
1527 for (i = 1; i < SECINITSID_NUM; i++) {
1528 const char *s = initial_sid_to_string[i];
1529
1530 if (s && !strcmp(s, scontext2)) {
1531 *sid = i;
1532 goto out;
1533 }
1534 }
1535 *sid = SECINITSID_KERNEL;
1536 goto out;
1537 }
1538 *sid = SECSID_NULL;
1539
1540 if (force) {
1541 /* Save another copy for storing in uninterpreted form */
1542 rc = -ENOMEM;
1543 str = kstrdup(scontext2, gfp_flags);
1544 if (!str)
1545 goto out;
1546 }
1547retry:
1548 rcu_read_lock();
1549 policy = rcu_dereference(selinux_state.policy);
1550 policydb = &policy->policydb;
1551 sidtab = policy->sidtab;
1552 rc = string_to_context_struct(policydb, sidtab, scontext2,
1553 &context, def_sid);
1554 if (rc == -EINVAL && force) {
1555 context.str = str;
1556 context.len = strlen(str) + 1;
1557 str = NULL;
1558 } else if (rc)
1559 goto out_unlock;
1560 rc = sidtab_context_to_sid(sidtab, &context, sid);
1561 if (rc == -ESTALE) {
1562 rcu_read_unlock();
1563 if (context.str) {
1564 str = context.str;
1565 context.str = NULL;
1566 }
1567 context_destroy(&context);
1568 goto retry;
1569 }
1570 context_destroy(&context);
1571out_unlock:
1572 rcu_read_unlock();
1573out:
1574 kfree(scontext2);
1575 kfree(str);
1576 return rc;
1577}
1578
1579/**
1580 * security_context_to_sid - Obtain a SID for a given security context.
1581 * @scontext: security context
1582 * @scontext_len: length in bytes
1583 * @sid: security identifier, SID
1584 * @gfp: context for the allocation
1585 *
1586 * Obtains a SID associated with the security context that
1587 * has the string representation specified by @scontext.
1588 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1589 * memory is available, or 0 on success.
1590 */
1591int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1592 gfp_t gfp)
1593{
1594 return security_context_to_sid_core(scontext, scontext_len,
1595 sid, SECSID_NULL, gfp, 0);
1596}
1597
1598int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1599{
1600 return security_context_to_sid(scontext, strlen(scontext),
1601 sid, gfp);
1602}
1603
1604/**
1605 * security_context_to_sid_default - Obtain a SID for a given security context,
1606 * falling back to specified default if needed.
1607 *
1608 * @scontext: security context
1609 * @scontext_len: length in bytes
1610 * @sid: security identifier, SID
1611 * @def_sid: default SID to assign on error
1612 * @gfp_flags: the allocator get-free-page (GFP) flags
1613 *
1614 * Obtains a SID associated with the security context that
1615 * has the string representation specified by @scontext.
1616 * The default SID is passed to the MLS layer to be used to allow
1617 * kernel labeling of the MLS field if the MLS field is not present
1618 * (for upgrading to MLS without full relabel).
1619 * Implicitly forces adding of the context even if it cannot be mapped yet.
1620 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1621 * memory is available, or 0 on success.
1622 */
1623int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1624 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1625{
1626 return security_context_to_sid_core(scontext, scontext_len,
1627 sid, def_sid, gfp_flags, 1);
1628}
1629
1630int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1631 u32 *sid)
1632{
1633 return security_context_to_sid_core(scontext, scontext_len,
1634 sid, SECSID_NULL, GFP_KERNEL, 1);
1635}
1636
1637static int compute_sid_handle_invalid_context(
1638 struct selinux_policy *policy,
1639 struct sidtab_entry *sentry,
1640 struct sidtab_entry *tentry,
1641 u16 tclass,
1642 struct context *newcontext)
1643{
1644 struct policydb *policydb = &policy->policydb;
1645 struct sidtab *sidtab = policy->sidtab;
1646 char *s = NULL, *t = NULL, *n = NULL;
1647 u32 slen, tlen, nlen;
1648 struct audit_buffer *ab;
1649
1650 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1651 goto out;
1652 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1653 goto out;
1654 if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1655 goto out;
1656 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1657 if (!ab)
1658 goto out;
1659 audit_log_format(ab,
1660 "op=security_compute_sid invalid_context=");
1661 /* no need to record the NUL with untrusted strings */
1662 audit_log_n_untrustedstring(ab, n, nlen - 1);
1663 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1664 s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1665 audit_log_end(ab);
1666out:
1667 kfree(s);
1668 kfree(t);
1669 kfree(n);
1670 if (!enforcing_enabled())
1671 return 0;
1672 return -EACCES;
1673}
1674
1675static void filename_compute_type(struct policydb *policydb,
1676 struct context *newcontext,
1677 u32 stype, u32 ttype, u16 tclass,
1678 const char *objname)
1679{
1680 struct filename_trans_key ft;
1681 struct filename_trans_datum *datum;
1682
1683 /*
1684 * Most filename trans rules are going to live in specific directories
1685 * like /dev or /var/run. This bitmap will quickly skip rule searches
1686 * if the ttype does not contain any rules.
1687 */
1688 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1689 return;
1690
1691 ft.ttype = ttype;
1692 ft.tclass = tclass;
1693 ft.name = objname;
1694
1695 datum = policydb_filenametr_search(policydb, &ft);
1696 while (datum) {
1697 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1698 newcontext->type = datum->otype;
1699 return;
1700 }
1701 datum = datum->next;
1702 }
1703}
1704
1705static int security_compute_sid(u32 ssid,
1706 u32 tsid,
1707 u16 orig_tclass,
1708 u16 specified,
1709 const char *objname,
1710 u32 *out_sid,
1711 bool kern)
1712{
1713 struct selinux_policy *policy;
1714 struct policydb *policydb;
1715 struct sidtab *sidtab;
1716 struct class_datum *cladatum;
1717 struct context *scontext, *tcontext, newcontext;
1718 struct sidtab_entry *sentry, *tentry;
1719 struct avtab_key avkey;
1720 struct avtab_node *avnode, *node;
1721 u16 tclass;
1722 int rc = 0;
1723 bool sock;
1724
1725 if (!selinux_initialized()) {
1726 switch (orig_tclass) {
1727 case SECCLASS_PROCESS: /* kernel value */
1728 *out_sid = ssid;
1729 break;
1730 default:
1731 *out_sid = tsid;
1732 break;
1733 }
1734 goto out;
1735 }
1736
1737retry:
1738 cladatum = NULL;
1739 context_init(&newcontext);
1740
1741 rcu_read_lock();
1742
1743 policy = rcu_dereference(selinux_state.policy);
1744
1745 if (kern) {
1746 tclass = unmap_class(&policy->map, orig_tclass);
1747 sock = security_is_socket_class(orig_tclass);
1748 } else {
1749 tclass = orig_tclass;
1750 sock = security_is_socket_class(map_class(&policy->map,
1751 tclass));
1752 }
1753
1754 policydb = &policy->policydb;
1755 sidtab = policy->sidtab;
1756
1757 sentry = sidtab_search_entry(sidtab, ssid);
1758 if (!sentry) {
1759 pr_err("SELinux: %s: unrecognized SID %d\n",
1760 __func__, ssid);
1761 rc = -EINVAL;
1762 goto out_unlock;
1763 }
1764 tentry = sidtab_search_entry(sidtab, tsid);
1765 if (!tentry) {
1766 pr_err("SELinux: %s: unrecognized SID %d\n",
1767 __func__, tsid);
1768 rc = -EINVAL;
1769 goto out_unlock;
1770 }
1771
1772 scontext = &sentry->context;
1773 tcontext = &tentry->context;
1774
1775 if (tclass && tclass <= policydb->p_classes.nprim)
1776 cladatum = policydb->class_val_to_struct[tclass - 1];
1777
1778 /* Set the user identity. */
1779 switch (specified) {
1780 case AVTAB_TRANSITION:
1781 case AVTAB_CHANGE:
1782 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1783 newcontext.user = tcontext->user;
1784 } else {
1785 /* notice this gets both DEFAULT_SOURCE and unset */
1786 /* Use the process user identity. */
1787 newcontext.user = scontext->user;
1788 }
1789 break;
1790 case AVTAB_MEMBER:
1791 /* Use the related object owner. */
1792 newcontext.user = tcontext->user;
1793 break;
1794 }
1795
1796 /* Set the role to default values. */
1797 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1798 newcontext.role = scontext->role;
1799 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1800 newcontext.role = tcontext->role;
1801 } else {
1802 if ((tclass == policydb->process_class) || sock)
1803 newcontext.role = scontext->role;
1804 else
1805 newcontext.role = OBJECT_R_VAL;
1806 }
1807
1808 /* Set the type to default values. */
1809 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1810 newcontext.type = scontext->type;
1811 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1812 newcontext.type = tcontext->type;
1813 } else {
1814 if ((tclass == policydb->process_class) || sock) {
1815 /* Use the type of process. */
1816 newcontext.type = scontext->type;
1817 } else {
1818 /* Use the type of the related object. */
1819 newcontext.type = tcontext->type;
1820 }
1821 }
1822
1823 /* Look for a type transition/member/change rule. */
1824 avkey.source_type = scontext->type;
1825 avkey.target_type = tcontext->type;
1826 avkey.target_class = tclass;
1827 avkey.specified = specified;
1828 avnode = avtab_search_node(&policydb->te_avtab, &avkey);
1829
1830 /* If no permanent rule, also check for enabled conditional rules */
1831 if (!avnode) {
1832 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1833 for (; node; node = avtab_search_node_next(node, specified)) {
1834 if (node->key.specified & AVTAB_ENABLED) {
1835 avnode = node;
1836 break;
1837 }
1838 }
1839 }
1840
1841 if (avnode) {
1842 /* Use the type from the type transition/member/change rule. */
1843 newcontext.type = avnode->datum.u.data;
1844 }
1845
1846 /* if we have a objname this is a file trans check so check those rules */
1847 if (objname)
1848 filename_compute_type(policydb, &newcontext, scontext->type,
1849 tcontext->type, tclass, objname);
1850
1851 /* Check for class-specific changes. */
1852 if (specified & AVTAB_TRANSITION) {
1853 /* Look for a role transition rule. */
1854 struct role_trans_datum *rtd;
1855 struct role_trans_key rtk = {
1856 .role = scontext->role,
1857 .type = tcontext->type,
1858 .tclass = tclass,
1859 };
1860
1861 rtd = policydb_roletr_search(policydb, &rtk);
1862 if (rtd)
1863 newcontext.role = rtd->new_role;
1864 }
1865
1866 /* Set the MLS attributes.
1867 This is done last because it may allocate memory. */
1868 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1869 &newcontext, sock);
1870 if (rc)
1871 goto out_unlock;
1872
1873 /* Check the validity of the context. */
1874 if (!policydb_context_isvalid(policydb, &newcontext)) {
1875 rc = compute_sid_handle_invalid_context(policy, sentry,
1876 tentry, tclass,
1877 &newcontext);
1878 if (rc)
1879 goto out_unlock;
1880 }
1881 /* Obtain the sid for the context. */
1882 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1883 if (rc == -ESTALE) {
1884 rcu_read_unlock();
1885 context_destroy(&newcontext);
1886 goto retry;
1887 }
1888out_unlock:
1889 rcu_read_unlock();
1890 context_destroy(&newcontext);
1891out:
1892 return rc;
1893}
1894
1895/**
1896 * security_transition_sid - Compute the SID for a new subject/object.
1897 * @ssid: source security identifier
1898 * @tsid: target security identifier
1899 * @tclass: target security class
1900 * @qstr: object name
1901 * @out_sid: security identifier for new subject/object
1902 *
1903 * Compute a SID to use for labeling a new subject or object in the
1904 * class @tclass based on a SID pair (@ssid, @tsid).
1905 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1906 * if insufficient memory is available, or %0 if the new SID was
1907 * computed successfully.
1908 */
1909int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1910 const struct qstr *qstr, u32 *out_sid)
1911{
1912 return security_compute_sid(ssid, tsid, tclass,
1913 AVTAB_TRANSITION,
1914 qstr ? qstr->name : NULL, out_sid, true);
1915}
1916
1917int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1918 const char *objname, u32 *out_sid)
1919{
1920 return security_compute_sid(ssid, tsid, tclass,
1921 AVTAB_TRANSITION,
1922 objname, out_sid, false);
1923}
1924
1925/**
1926 * security_member_sid - Compute the SID for member selection.
1927 * @ssid: source security identifier
1928 * @tsid: target security identifier
1929 * @tclass: target security class
1930 * @out_sid: security identifier for selected member
1931 *
1932 * Compute a SID to use when selecting a member of a polyinstantiated
1933 * object of class @tclass based on a SID pair (@ssid, @tsid).
1934 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1935 * if insufficient memory is available, or %0 if the SID was
1936 * computed successfully.
1937 */
1938int security_member_sid(u32 ssid,
1939 u32 tsid,
1940 u16 tclass,
1941 u32 *out_sid)
1942{
1943 return security_compute_sid(ssid, tsid, tclass,
1944 AVTAB_MEMBER, NULL,
1945 out_sid, false);
1946}
1947
1948/**
1949 * security_change_sid - Compute the SID for object relabeling.
1950 * @ssid: source security identifier
1951 * @tsid: target security identifier
1952 * @tclass: target security class
1953 * @out_sid: security identifier for selected member
1954 *
1955 * Compute a SID to use for relabeling an object of class @tclass
1956 * based on a SID pair (@ssid, @tsid).
1957 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1958 * if insufficient memory is available, or %0 if the SID was
1959 * computed successfully.
1960 */
1961int security_change_sid(u32 ssid,
1962 u32 tsid,
1963 u16 tclass,
1964 u32 *out_sid)
1965{
1966 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1967 out_sid, false);
1968}
1969
1970static inline int convert_context_handle_invalid_context(
1971 struct policydb *policydb,
1972 struct context *context)
1973{
1974 char *s;
1975 u32 len;
1976
1977 if (enforcing_enabled())
1978 return -EINVAL;
1979
1980 if (!context_struct_to_string(policydb, context, &s, &len)) {
1981 pr_warn("SELinux: Context %s would be invalid if enforcing\n",
1982 s);
1983 kfree(s);
1984 }
1985 return 0;
1986}
1987
1988/**
1989 * services_convert_context - Convert a security context across policies.
1990 * @args: populated convert_context_args struct
1991 * @oldc: original context
1992 * @newc: converted context
1993 * @gfp_flags: allocation flags
1994 *
1995 * Convert the values in the security context structure @oldc from the values
1996 * specified in the policy @args->oldp to the values specified in the policy
1997 * @args->newp, storing the new context in @newc, and verifying that the
1998 * context is valid under the new policy.
1999 */
2000int services_convert_context(struct convert_context_args *args,
2001 struct context *oldc, struct context *newc,
2002 gfp_t gfp_flags)
2003{
2004 struct ocontext *oc;
2005 struct role_datum *role;
2006 struct type_datum *typdatum;
2007 struct user_datum *usrdatum;
2008 char *s;
2009 u32 len;
2010 int rc;
2011
2012 if (oldc->str) {
2013 s = kstrdup(oldc->str, gfp_flags);
2014 if (!s)
2015 return -ENOMEM;
2016
2017 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL);
2018 if (rc == -EINVAL) {
2019 /*
2020 * Retain string representation for later mapping.
2021 *
2022 * IMPORTANT: We need to copy the contents of oldc->str
2023 * back into s again because string_to_context_struct()
2024 * may have garbled it.
2025 */
2026 memcpy(s, oldc->str, oldc->len);
2027 context_init(newc);
2028 newc->str = s;
2029 newc->len = oldc->len;
2030 return 0;
2031 }
2032 kfree(s);
2033 if (rc) {
2034 /* Other error condition, e.g. ENOMEM. */
2035 pr_err("SELinux: Unable to map context %s, rc = %d.\n",
2036 oldc->str, -rc);
2037 return rc;
2038 }
2039 pr_info("SELinux: Context %s became valid (mapped).\n",
2040 oldc->str);
2041 return 0;
2042 }
2043
2044 context_init(newc);
2045
2046 /* Convert the user. */
2047 usrdatum = symtab_search(&args->newp->p_users,
2048 sym_name(args->oldp, SYM_USERS, oldc->user - 1));
2049 if (!usrdatum)
2050 goto bad;
2051 newc->user = usrdatum->value;
2052
2053 /* Convert the role. */
2054 role = symtab_search(&args->newp->p_roles,
2055 sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2056 if (!role)
2057 goto bad;
2058 newc->role = role->value;
2059
2060 /* Convert the type. */
2061 typdatum = symtab_search(&args->newp->p_types,
2062 sym_name(args->oldp, SYM_TYPES, oldc->type - 1));
2063 if (!typdatum)
2064 goto bad;
2065 newc->type = typdatum->value;
2066
2067 /* Convert the MLS fields if dealing with MLS policies */
2068 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2069 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2070 if (rc)
2071 goto bad;
2072 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2073 /*
2074 * Switching between non-MLS and MLS policy:
2075 * ensure that the MLS fields of the context for all
2076 * existing entries in the sidtab are filled in with a
2077 * suitable default value, likely taken from one of the
2078 * initial SIDs.
2079 */
2080 oc = args->newp->ocontexts[OCON_ISID];
2081 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2082 oc = oc->next;
2083 if (!oc) {
2084 pr_err("SELinux: unable to look up"
2085 " the initial SIDs list\n");
2086 goto bad;
2087 }
2088 rc = mls_range_set(newc, &oc->context[0].range);
2089 if (rc)
2090 goto bad;
2091 }
2092
2093 /* Check the validity of the new context. */
2094 if (!policydb_context_isvalid(args->newp, newc)) {
2095 rc = convert_context_handle_invalid_context(args->oldp, oldc);
2096 if (rc)
2097 goto bad;
2098 }
2099
2100 return 0;
2101bad:
2102 /* Map old representation to string and save it. */
2103 rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2104 if (rc)
2105 return rc;
2106 context_destroy(newc);
2107 newc->str = s;
2108 newc->len = len;
2109 pr_info("SELinux: Context %s became invalid (unmapped).\n",
2110 newc->str);
2111 return 0;
2112}
2113
2114static void security_load_policycaps(struct selinux_policy *policy)
2115{
2116 struct policydb *p;
2117 unsigned int i;
2118 struct ebitmap_node *node;
2119
2120 p = &policy->policydb;
2121
2122 for (i = 0; i < ARRAY_SIZE(selinux_state.policycap); i++)
2123 WRITE_ONCE(selinux_state.policycap[i],
2124 ebitmap_get_bit(&p->policycaps, i));
2125
2126 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2127 pr_info("SELinux: policy capability %s=%d\n",
2128 selinux_policycap_names[i],
2129 ebitmap_get_bit(&p->policycaps, i));
2130
2131 ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2132 if (i >= ARRAY_SIZE(selinux_policycap_names))
2133 pr_info("SELinux: unknown policy capability %u\n",
2134 i);
2135 }
2136}
2137
2138static int security_preserve_bools(struct selinux_policy *oldpolicy,
2139 struct selinux_policy *newpolicy);
2140
2141static void selinux_policy_free(struct selinux_policy *policy)
2142{
2143 if (!policy)
2144 return;
2145
2146 sidtab_destroy(policy->sidtab);
2147 kfree(policy->map.mapping);
2148 policydb_destroy(&policy->policydb);
2149 kfree(policy->sidtab);
2150 kfree(policy);
2151}
2152
2153static void selinux_policy_cond_free(struct selinux_policy *policy)
2154{
2155 cond_policydb_destroy_dup(&policy->policydb);
2156 kfree(policy);
2157}
2158
2159void selinux_policy_cancel(struct selinux_load_state *load_state)
2160{
2161 struct selinux_state *state = &selinux_state;
2162 struct selinux_policy *oldpolicy;
2163
2164 oldpolicy = rcu_dereference_protected(state->policy,
2165 lockdep_is_held(&state->policy_mutex));
2166
2167 sidtab_cancel_convert(oldpolicy->sidtab);
2168 selinux_policy_free(load_state->policy);
2169 kfree(load_state->convert_data);
2170}
2171
2172static void selinux_notify_policy_change(u32 seqno)
2173{
2174 /* Flush external caches and notify userspace of policy load */
2175 avc_ss_reset(seqno);
2176 selnl_notify_policyload(seqno);
2177 selinux_status_update_policyload(seqno);
2178 selinux_netlbl_cache_invalidate();
2179 selinux_xfrm_notify_policyload();
2180 selinux_ima_measure_state_locked();
2181}
2182
2183void selinux_policy_commit(struct selinux_load_state *load_state)
2184{
2185 struct selinux_state *state = &selinux_state;
2186 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
2187 unsigned long flags;
2188 u32 seqno;
2189
2190 oldpolicy = rcu_dereference_protected(state->policy,
2191 lockdep_is_held(&state->policy_mutex));
2192
2193 /* If switching between different policy types, log MLS status */
2194 if (oldpolicy) {
2195 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
2196 pr_info("SELinux: Disabling MLS support...\n");
2197 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
2198 pr_info("SELinux: Enabling MLS support...\n");
2199 }
2200
2201 /* Set latest granting seqno for new policy. */
2202 if (oldpolicy)
2203 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
2204 else
2205 newpolicy->latest_granting = 1;
2206 seqno = newpolicy->latest_granting;
2207
2208 /* Install the new policy. */
2209 if (oldpolicy) {
2210 sidtab_freeze_begin(oldpolicy->sidtab, &flags);
2211 rcu_assign_pointer(state->policy, newpolicy);
2212 sidtab_freeze_end(oldpolicy->sidtab, &flags);
2213 } else {
2214 rcu_assign_pointer(state->policy, newpolicy);
2215 }
2216
2217 /* Load the policycaps from the new policy */
2218 security_load_policycaps(newpolicy);
2219
2220 if (!selinux_initialized()) {
2221 /*
2222 * After first policy load, the security server is
2223 * marked as initialized and ready to handle requests and
2224 * any objects created prior to policy load are then labeled.
2225 */
2226 selinux_mark_initialized();
2227 selinux_complete_init();
2228 }
2229
2230 /* Free the old policy */
2231 synchronize_rcu();
2232 selinux_policy_free(oldpolicy);
2233 kfree(load_state->convert_data);
2234
2235 /* Notify others of the policy change */
2236 selinux_notify_policy_change(seqno);
2237}
2238
2239/**
2240 * security_load_policy - Load a security policy configuration.
2241 * @data: binary policy data
2242 * @len: length of data in bytes
2243 * @load_state: policy load state
2244 *
2245 * Load a new set of security policy configuration data,
2246 * validate it and convert the SID table as necessary.
2247 * This function will flush the access vector cache after
2248 * loading the new policy.
2249 */
2250int security_load_policy(void *data, size_t len,
2251 struct selinux_load_state *load_state)
2252{
2253 struct selinux_state *state = &selinux_state;
2254 struct selinux_policy *newpolicy, *oldpolicy;
2255 struct selinux_policy_convert_data *convert_data;
2256 int rc = 0;
2257 struct policy_file file = { data, len }, *fp = &file;
2258
2259 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2260 if (!newpolicy)
2261 return -ENOMEM;
2262
2263 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2264 if (!newpolicy->sidtab) {
2265 rc = -ENOMEM;
2266 goto err_policy;
2267 }
2268
2269 rc = policydb_read(&newpolicy->policydb, fp);
2270 if (rc)
2271 goto err_sidtab;
2272
2273 newpolicy->policydb.len = len;
2274 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2275 &newpolicy->map);
2276 if (rc)
2277 goto err_policydb;
2278
2279 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2280 if (rc) {
2281 pr_err("SELinux: unable to load the initial SIDs\n");
2282 goto err_mapping;
2283 }
2284
2285 if (!selinux_initialized()) {
2286 /* First policy load, so no need to preserve state from old policy */
2287 load_state->policy = newpolicy;
2288 load_state->convert_data = NULL;
2289 return 0;
2290 }
2291
2292 oldpolicy = rcu_dereference_protected(state->policy,
2293 lockdep_is_held(&state->policy_mutex));
2294
2295 /* Preserve active boolean values from the old policy */
2296 rc = security_preserve_bools(oldpolicy, newpolicy);
2297 if (rc) {
2298 pr_err("SELinux: unable to preserve booleans\n");
2299 goto err_free_isids;
2300 }
2301
2302 /*
2303 * Convert the internal representations of contexts
2304 * in the new SID table.
2305 */
2306
2307 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2308 if (!convert_data) {
2309 rc = -ENOMEM;
2310 goto err_free_isids;
2311 }
2312
2313 convert_data->args.oldp = &oldpolicy->policydb;
2314 convert_data->args.newp = &newpolicy->policydb;
2315
2316 convert_data->sidtab_params.args = &convert_data->args;
2317 convert_data->sidtab_params.target = newpolicy->sidtab;
2318
2319 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2320 if (rc) {
2321 pr_err("SELinux: unable to convert the internal"
2322 " representation of contexts in the new SID"
2323 " table\n");
2324 goto err_free_convert_data;
2325 }
2326
2327 load_state->policy = newpolicy;
2328 load_state->convert_data = convert_data;
2329 return 0;
2330
2331err_free_convert_data:
2332 kfree(convert_data);
2333err_free_isids:
2334 sidtab_destroy(newpolicy->sidtab);
2335err_mapping:
2336 kfree(newpolicy->map.mapping);
2337err_policydb:
2338 policydb_destroy(&newpolicy->policydb);
2339err_sidtab:
2340 kfree(newpolicy->sidtab);
2341err_policy:
2342 kfree(newpolicy);
2343
2344 return rc;
2345}
2346
2347/**
2348 * ocontext_to_sid - Helper to safely get sid for an ocontext
2349 * @sidtab: SID table
2350 * @c: ocontext structure
2351 * @index: index of the context entry (0 or 1)
2352 * @out_sid: pointer to the resulting SID value
2353 *
2354 * For all ocontexts except OCON_ISID the SID fields are populated
2355 * on-demand when needed. Since updating the SID value is an SMP-sensitive
2356 * operation, this helper must be used to do that safely.
2357 *
2358 * WARNING: This function may return -ESTALE, indicating that the caller
2359 * must retry the operation after re-acquiring the policy pointer!
2360 */
2361static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
2362 size_t index, u32 *out_sid)
2363{
2364 int rc;
2365 u32 sid;
2366
2367 /* Ensure the associated sidtab entry is visible to this thread. */
2368 sid = smp_load_acquire(&c->sid[index]);
2369 if (!sid) {
2370 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
2371 if (rc)
2372 return rc;
2373
2374 /*
2375 * Ensure the new sidtab entry is visible to other threads
2376 * when they see the SID.
2377 */
2378 smp_store_release(&c->sid[index], sid);
2379 }
2380 *out_sid = sid;
2381 return 0;
2382}
2383
2384/**
2385 * security_port_sid - Obtain the SID for a port.
2386 * @protocol: protocol number
2387 * @port: port number
2388 * @out_sid: security identifier
2389 */
2390int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2391{
2392 struct selinux_policy *policy;
2393 struct policydb *policydb;
2394 struct sidtab *sidtab;
2395 struct ocontext *c;
2396 int rc;
2397
2398 if (!selinux_initialized()) {
2399 *out_sid = SECINITSID_PORT;
2400 return 0;
2401 }
2402
2403retry:
2404 rc = 0;
2405 rcu_read_lock();
2406 policy = rcu_dereference(selinux_state.policy);
2407 policydb = &policy->policydb;
2408 sidtab = policy->sidtab;
2409
2410 c = policydb->ocontexts[OCON_PORT];
2411 while (c) {
2412 if (c->u.port.protocol == protocol &&
2413 c->u.port.low_port <= port &&
2414 c->u.port.high_port >= port)
2415 break;
2416 c = c->next;
2417 }
2418
2419 if (c) {
2420 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2421 if (rc == -ESTALE) {
2422 rcu_read_unlock();
2423 goto retry;
2424 }
2425 if (rc)
2426 goto out;
2427 } else {
2428 *out_sid = SECINITSID_PORT;
2429 }
2430
2431out:
2432 rcu_read_unlock();
2433 return rc;
2434}
2435
2436/**
2437 * security_ib_pkey_sid - Obtain the SID for a pkey.
2438 * @subnet_prefix: Subnet Prefix
2439 * @pkey_num: pkey number
2440 * @out_sid: security identifier
2441 */
2442int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2443{
2444 struct selinux_policy *policy;
2445 struct policydb *policydb;
2446 struct sidtab *sidtab;
2447 struct ocontext *c;
2448 int rc;
2449
2450 if (!selinux_initialized()) {
2451 *out_sid = SECINITSID_UNLABELED;
2452 return 0;
2453 }
2454
2455retry:
2456 rc = 0;
2457 rcu_read_lock();
2458 policy = rcu_dereference(selinux_state.policy);
2459 policydb = &policy->policydb;
2460 sidtab = policy->sidtab;
2461
2462 c = policydb->ocontexts[OCON_IBPKEY];
2463 while (c) {
2464 if (c->u.ibpkey.low_pkey <= pkey_num &&
2465 c->u.ibpkey.high_pkey >= pkey_num &&
2466 c->u.ibpkey.subnet_prefix == subnet_prefix)
2467 break;
2468
2469 c = c->next;
2470 }
2471
2472 if (c) {
2473 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2474 if (rc == -ESTALE) {
2475 rcu_read_unlock();
2476 goto retry;
2477 }
2478 if (rc)
2479 goto out;
2480 } else
2481 *out_sid = SECINITSID_UNLABELED;
2482
2483out:
2484 rcu_read_unlock();
2485 return rc;
2486}
2487
2488/**
2489 * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2490 * @dev_name: device name
2491 * @port_num: port number
2492 * @out_sid: security identifier
2493 */
2494int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid)
2495{
2496 struct selinux_policy *policy;
2497 struct policydb *policydb;
2498 struct sidtab *sidtab;
2499 struct ocontext *c;
2500 int rc;
2501
2502 if (!selinux_initialized()) {
2503 *out_sid = SECINITSID_UNLABELED;
2504 return 0;
2505 }
2506
2507retry:
2508 rc = 0;
2509 rcu_read_lock();
2510 policy = rcu_dereference(selinux_state.policy);
2511 policydb = &policy->policydb;
2512 sidtab = policy->sidtab;
2513
2514 c = policydb->ocontexts[OCON_IBENDPORT];
2515 while (c) {
2516 if (c->u.ibendport.port == port_num &&
2517 !strncmp(c->u.ibendport.dev_name,
2518 dev_name,
2519 IB_DEVICE_NAME_MAX))
2520 break;
2521
2522 c = c->next;
2523 }
2524
2525 if (c) {
2526 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2527 if (rc == -ESTALE) {
2528 rcu_read_unlock();
2529 goto retry;
2530 }
2531 if (rc)
2532 goto out;
2533 } else
2534 *out_sid = SECINITSID_UNLABELED;
2535
2536out:
2537 rcu_read_unlock();
2538 return rc;
2539}
2540
2541/**
2542 * security_netif_sid - Obtain the SID for a network interface.
2543 * @name: interface name
2544 * @if_sid: interface SID
2545 */
2546int security_netif_sid(char *name, u32 *if_sid)
2547{
2548 struct selinux_policy *policy;
2549 struct policydb *policydb;
2550 struct sidtab *sidtab;
2551 int rc;
2552 struct ocontext *c;
2553
2554 if (!selinux_initialized()) {
2555 *if_sid = SECINITSID_NETIF;
2556 return 0;
2557 }
2558
2559retry:
2560 rc = 0;
2561 rcu_read_lock();
2562 policy = rcu_dereference(selinux_state.policy);
2563 policydb = &policy->policydb;
2564 sidtab = policy->sidtab;
2565
2566 c = policydb->ocontexts[OCON_NETIF];
2567 while (c) {
2568 if (strcmp(name, c->u.name) == 0)
2569 break;
2570 c = c->next;
2571 }
2572
2573 if (c) {
2574 rc = ocontext_to_sid(sidtab, c, 0, if_sid);
2575 if (rc == -ESTALE) {
2576 rcu_read_unlock();
2577 goto retry;
2578 }
2579 if (rc)
2580 goto out;
2581 } else
2582 *if_sid = SECINITSID_NETIF;
2583
2584out:
2585 rcu_read_unlock();
2586 return rc;
2587}
2588
2589static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2590{
2591 int i, fail = 0;
2592
2593 for (i = 0; i < 4; i++)
2594 if (addr[i] != (input[i] & mask[i])) {
2595 fail = 1;
2596 break;
2597 }
2598
2599 return !fail;
2600}
2601
2602/**
2603 * security_node_sid - Obtain the SID for a node (host).
2604 * @domain: communication domain aka address family
2605 * @addrp: address
2606 * @addrlen: address length in bytes
2607 * @out_sid: security identifier
2608 */
2609int security_node_sid(u16 domain,
2610 void *addrp,
2611 u32 addrlen,
2612 u32 *out_sid)
2613{
2614 struct selinux_policy *policy;
2615 struct policydb *policydb;
2616 struct sidtab *sidtab;
2617 int rc;
2618 struct ocontext *c;
2619
2620 if (!selinux_initialized()) {
2621 *out_sid = SECINITSID_NODE;
2622 return 0;
2623 }
2624
2625retry:
2626 rcu_read_lock();
2627 policy = rcu_dereference(selinux_state.policy);
2628 policydb = &policy->policydb;
2629 sidtab = policy->sidtab;
2630
2631 switch (domain) {
2632 case AF_INET: {
2633 u32 addr;
2634
2635 rc = -EINVAL;
2636 if (addrlen != sizeof(u32))
2637 goto out;
2638
2639 addr = *((u32 *)addrp);
2640
2641 c = policydb->ocontexts[OCON_NODE];
2642 while (c) {
2643 if (c->u.node.addr == (addr & c->u.node.mask))
2644 break;
2645 c = c->next;
2646 }
2647 break;
2648 }
2649
2650 case AF_INET6:
2651 rc = -EINVAL;
2652 if (addrlen != sizeof(u64) * 2)
2653 goto out;
2654 c = policydb->ocontexts[OCON_NODE6];
2655 while (c) {
2656 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2657 c->u.node6.mask))
2658 break;
2659 c = c->next;
2660 }
2661 break;
2662
2663 default:
2664 rc = 0;
2665 *out_sid = SECINITSID_NODE;
2666 goto out;
2667 }
2668
2669 if (c) {
2670 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2671 if (rc == -ESTALE) {
2672 rcu_read_unlock();
2673 goto retry;
2674 }
2675 if (rc)
2676 goto out;
2677 } else {
2678 *out_sid = SECINITSID_NODE;
2679 }
2680
2681 rc = 0;
2682out:
2683 rcu_read_unlock();
2684 return rc;
2685}
2686
2687#define SIDS_NEL 25
2688
2689/**
2690 * security_get_user_sids - Obtain reachable SIDs for a user.
2691 * @fromsid: starting SID
2692 * @username: username
2693 * @sids: array of reachable SIDs for user
2694 * @nel: number of elements in @sids
2695 *
2696 * Generate the set of SIDs for legal security contexts
2697 * for a given user that can be reached by @fromsid.
2698 * Set *@sids to point to a dynamically allocated
2699 * array containing the set of SIDs. Set *@nel to the
2700 * number of elements in the array.
2701 */
2702
2703int security_get_user_sids(u32 fromsid,
2704 char *username,
2705 u32 **sids,
2706 u32 *nel)
2707{
2708 struct selinux_policy *policy;
2709 struct policydb *policydb;
2710 struct sidtab *sidtab;
2711 struct context *fromcon, usercon;
2712 u32 *mysids = NULL, *mysids2, sid;
2713 u32 i, j, mynel, maxnel = SIDS_NEL;
2714 struct user_datum *user;
2715 struct role_datum *role;
2716 struct ebitmap_node *rnode, *tnode;
2717 int rc;
2718
2719 *sids = NULL;
2720 *nel = 0;
2721
2722 if (!selinux_initialized())
2723 return 0;
2724
2725 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2726 if (!mysids)
2727 return -ENOMEM;
2728
2729retry:
2730 mynel = 0;
2731 rcu_read_lock();
2732 policy = rcu_dereference(selinux_state.policy);
2733 policydb = &policy->policydb;
2734 sidtab = policy->sidtab;
2735
2736 context_init(&usercon);
2737
2738 rc = -EINVAL;
2739 fromcon = sidtab_search(sidtab, fromsid);
2740 if (!fromcon)
2741 goto out_unlock;
2742
2743 rc = -EINVAL;
2744 user = symtab_search(&policydb->p_users, username);
2745 if (!user)
2746 goto out_unlock;
2747
2748 usercon.user = user->value;
2749
2750 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2751 role = policydb->role_val_to_struct[i];
2752 usercon.role = i + 1;
2753 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2754 usercon.type = j + 1;
2755
2756 if (mls_setup_user_range(policydb, fromcon, user,
2757 &usercon))
2758 continue;
2759
2760 rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2761 if (rc == -ESTALE) {
2762 rcu_read_unlock();
2763 goto retry;
2764 }
2765 if (rc)
2766 goto out_unlock;
2767 if (mynel < maxnel) {
2768 mysids[mynel++] = sid;
2769 } else {
2770 rc = -ENOMEM;
2771 maxnel += SIDS_NEL;
2772 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2773 if (!mysids2)
2774 goto out_unlock;
2775 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2776 kfree(mysids);
2777 mysids = mysids2;
2778 mysids[mynel++] = sid;
2779 }
2780 }
2781 }
2782 rc = 0;
2783out_unlock:
2784 rcu_read_unlock();
2785 if (rc || !mynel) {
2786 kfree(mysids);
2787 return rc;
2788 }
2789
2790 rc = -ENOMEM;
2791 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2792 if (!mysids2) {
2793 kfree(mysids);
2794 return rc;
2795 }
2796 for (i = 0, j = 0; i < mynel; i++) {
2797 struct av_decision dummy_avd;
2798 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2799 SECCLASS_PROCESS, /* kernel value */
2800 PROCESS__TRANSITION, AVC_STRICT,
2801 &dummy_avd);
2802 if (!rc)
2803 mysids2[j++] = mysids[i];
2804 cond_resched();
2805 }
2806 kfree(mysids);
2807 *sids = mysids2;
2808 *nel = j;
2809 return 0;
2810}
2811
2812/**
2813 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2814 * @policy: policy
2815 * @fstype: filesystem type
2816 * @path: path from root of mount
2817 * @orig_sclass: file security class
2818 * @sid: SID for path
2819 *
2820 * Obtain a SID to use for a file in a filesystem that
2821 * cannot support xattr or use a fixed labeling behavior like
2822 * transition SIDs or task SIDs.
2823 *
2824 * WARNING: This function may return -ESTALE, indicating that the caller
2825 * must retry the operation after re-acquiring the policy pointer!
2826 */
2827static inline int __security_genfs_sid(struct selinux_policy *policy,
2828 const char *fstype,
2829 const char *path,
2830 u16 orig_sclass,
2831 u32 *sid)
2832{
2833 struct policydb *policydb = &policy->policydb;
2834 struct sidtab *sidtab = policy->sidtab;
2835 u16 sclass;
2836 struct genfs *genfs;
2837 struct ocontext *c;
2838 int cmp = 0;
2839
2840 while (path[0] == '/' && path[1] == '/')
2841 path++;
2842
2843 sclass = unmap_class(&policy->map, orig_sclass);
2844 *sid = SECINITSID_UNLABELED;
2845
2846 for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2847 cmp = strcmp(fstype, genfs->fstype);
2848 if (cmp <= 0)
2849 break;
2850 }
2851
2852 if (!genfs || cmp)
2853 return -ENOENT;
2854
2855 for (c = genfs->head; c; c = c->next) {
2856 size_t len = strlen(c->u.name);
2857 if ((!c->v.sclass || sclass == c->v.sclass) &&
2858 (strncmp(c->u.name, path, len) == 0))
2859 break;
2860 }
2861
2862 if (!c)
2863 return -ENOENT;
2864
2865 return ocontext_to_sid(sidtab, c, 0, sid);
2866}
2867
2868/**
2869 * security_genfs_sid - Obtain a SID for a file in a filesystem
2870 * @fstype: filesystem type
2871 * @path: path from root of mount
2872 * @orig_sclass: file security class
2873 * @sid: SID for path
2874 *
2875 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2876 * it afterward.
2877 */
2878int security_genfs_sid(const char *fstype,
2879 const char *path,
2880 u16 orig_sclass,
2881 u32 *sid)
2882{
2883 struct selinux_policy *policy;
2884 int retval;
2885
2886 if (!selinux_initialized()) {
2887 *sid = SECINITSID_UNLABELED;
2888 return 0;
2889 }
2890
2891 do {
2892 rcu_read_lock();
2893 policy = rcu_dereference(selinux_state.policy);
2894 retval = __security_genfs_sid(policy, fstype, path,
2895 orig_sclass, sid);
2896 rcu_read_unlock();
2897 } while (retval == -ESTALE);
2898 return retval;
2899}
2900
2901int selinux_policy_genfs_sid(struct selinux_policy *policy,
2902 const char *fstype,
2903 const char *path,
2904 u16 orig_sclass,
2905 u32 *sid)
2906{
2907 /* no lock required, policy is not yet accessible by other threads */
2908 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2909}
2910
2911/**
2912 * security_fs_use - Determine how to handle labeling for a filesystem.
2913 * @sb: superblock in question
2914 */
2915int security_fs_use(struct super_block *sb)
2916{
2917 struct selinux_policy *policy;
2918 struct policydb *policydb;
2919 struct sidtab *sidtab;
2920 int rc;
2921 struct ocontext *c;
2922 struct superblock_security_struct *sbsec = selinux_superblock(sb);
2923 const char *fstype = sb->s_type->name;
2924
2925 if (!selinux_initialized()) {
2926 sbsec->behavior = SECURITY_FS_USE_NONE;
2927 sbsec->sid = SECINITSID_UNLABELED;
2928 return 0;
2929 }
2930
2931retry:
2932 rcu_read_lock();
2933 policy = rcu_dereference(selinux_state.policy);
2934 policydb = &policy->policydb;
2935 sidtab = policy->sidtab;
2936
2937 c = policydb->ocontexts[OCON_FSUSE];
2938 while (c) {
2939 if (strcmp(fstype, c->u.name) == 0)
2940 break;
2941 c = c->next;
2942 }
2943
2944 if (c) {
2945 sbsec->behavior = c->v.behavior;
2946 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
2947 if (rc == -ESTALE) {
2948 rcu_read_unlock();
2949 goto retry;
2950 }
2951 if (rc)
2952 goto out;
2953 } else {
2954 rc = __security_genfs_sid(policy, fstype, "/",
2955 SECCLASS_DIR, &sbsec->sid);
2956 if (rc == -ESTALE) {
2957 rcu_read_unlock();
2958 goto retry;
2959 }
2960 if (rc) {
2961 sbsec->behavior = SECURITY_FS_USE_NONE;
2962 rc = 0;
2963 } else {
2964 sbsec->behavior = SECURITY_FS_USE_GENFS;
2965 }
2966 }
2967
2968out:
2969 rcu_read_unlock();
2970 return rc;
2971}
2972
2973int security_get_bools(struct selinux_policy *policy,
2974 u32 *len, char ***names, int **values)
2975{
2976 struct policydb *policydb;
2977 u32 i;
2978 int rc;
2979
2980 policydb = &policy->policydb;
2981
2982 *names = NULL;
2983 *values = NULL;
2984
2985 rc = 0;
2986 *len = policydb->p_bools.nprim;
2987 if (!*len)
2988 goto out;
2989
2990 rc = -ENOMEM;
2991 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2992 if (!*names)
2993 goto err;
2994
2995 rc = -ENOMEM;
2996 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2997 if (!*values)
2998 goto err;
2999
3000 for (i = 0; i < *len; i++) {
3001 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3002
3003 rc = -ENOMEM;
3004 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3005 GFP_ATOMIC);
3006 if (!(*names)[i])
3007 goto err;
3008 }
3009 rc = 0;
3010out:
3011 return rc;
3012err:
3013 if (*names) {
3014 for (i = 0; i < *len; i++)
3015 kfree((*names)[i]);
3016 kfree(*names);
3017 }
3018 kfree(*values);
3019 *len = 0;
3020 *names = NULL;
3021 *values = NULL;
3022 goto out;
3023}
3024
3025
3026int security_set_bools(u32 len, int *values)
3027{
3028 struct selinux_state *state = &selinux_state;
3029 struct selinux_policy *newpolicy, *oldpolicy;
3030 int rc;
3031 u32 i, seqno = 0;
3032
3033 if (!selinux_initialized())
3034 return -EINVAL;
3035
3036 oldpolicy = rcu_dereference_protected(state->policy,
3037 lockdep_is_held(&state->policy_mutex));
3038
3039 /* Consistency check on number of booleans, should never fail */
3040 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3041 return -EINVAL;
3042
3043 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3044 if (!newpolicy)
3045 return -ENOMEM;
3046
3047 /*
3048 * Deep copy only the parts of the policydb that might be
3049 * modified as a result of changing booleans.
3050 */
3051 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3052 if (rc) {
3053 kfree(newpolicy);
3054 return -ENOMEM;
3055 }
3056
3057 /* Update the boolean states in the copy */
3058 for (i = 0; i < len; i++) {
3059 int new_state = !!values[i];
3060 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3061
3062 if (new_state != old_state) {
3063 audit_log(audit_context(), GFP_ATOMIC,
3064 AUDIT_MAC_CONFIG_CHANGE,
3065 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3066 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3067 new_state,
3068 old_state,
3069 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3070 audit_get_sessionid(current));
3071 newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3072 }
3073 }
3074
3075 /* Re-evaluate the conditional rules in the copy */
3076 evaluate_cond_nodes(&newpolicy->policydb);
3077
3078 /* Set latest granting seqno for new policy */
3079 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3080 seqno = newpolicy->latest_granting;
3081
3082 /* Install the new policy */
3083 rcu_assign_pointer(state->policy, newpolicy);
3084
3085 /*
3086 * Free the conditional portions of the old policydb
3087 * that were copied for the new policy, and the oldpolicy
3088 * structure itself but not what it references.
3089 */
3090 synchronize_rcu();
3091 selinux_policy_cond_free(oldpolicy);
3092
3093 /* Notify others of the policy change */
3094 selinux_notify_policy_change(seqno);
3095 return 0;
3096}
3097
3098int security_get_bool_value(u32 index)
3099{
3100 struct selinux_policy *policy;
3101 struct policydb *policydb;
3102 int rc;
3103 u32 len;
3104
3105 if (!selinux_initialized())
3106 return 0;
3107
3108 rcu_read_lock();
3109 policy = rcu_dereference(selinux_state.policy);
3110 policydb = &policy->policydb;
3111
3112 rc = -EFAULT;
3113 len = policydb->p_bools.nprim;
3114 if (index >= len)
3115 goto out;
3116
3117 rc = policydb->bool_val_to_struct[index]->state;
3118out:
3119 rcu_read_unlock();
3120 return rc;
3121}
3122
3123static int security_preserve_bools(struct selinux_policy *oldpolicy,
3124 struct selinux_policy *newpolicy)
3125{
3126 int rc, *bvalues = NULL;
3127 char **bnames = NULL;
3128 struct cond_bool_datum *booldatum;
3129 u32 i, nbools = 0;
3130
3131 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3132 if (rc)
3133 goto out;
3134 for (i = 0; i < nbools; i++) {
3135 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3136 bnames[i]);
3137 if (booldatum)
3138 booldatum->state = bvalues[i];
3139 }
3140 evaluate_cond_nodes(&newpolicy->policydb);
3141
3142out:
3143 if (bnames) {
3144 for (i = 0; i < nbools; i++)
3145 kfree(bnames[i]);
3146 }
3147 kfree(bnames);
3148 kfree(bvalues);
3149 return rc;
3150}
3151
3152/*
3153 * security_sid_mls_copy() - computes a new sid based on the given
3154 * sid and the mls portion of mls_sid.
3155 */
3156int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
3157{
3158 struct selinux_policy *policy;
3159 struct policydb *policydb;
3160 struct sidtab *sidtab;
3161 struct context *context1;
3162 struct context *context2;
3163 struct context newcon;
3164 char *s;
3165 u32 len;
3166 int rc;
3167
3168 if (!selinux_initialized()) {
3169 *new_sid = sid;
3170 return 0;
3171 }
3172
3173retry:
3174 rc = 0;
3175 context_init(&newcon);
3176
3177 rcu_read_lock();
3178 policy = rcu_dereference(selinux_state.policy);
3179 policydb = &policy->policydb;
3180 sidtab = policy->sidtab;
3181
3182 if (!policydb->mls_enabled) {
3183 *new_sid = sid;
3184 goto out_unlock;
3185 }
3186
3187 rc = -EINVAL;
3188 context1 = sidtab_search(sidtab, sid);
3189 if (!context1) {
3190 pr_err("SELinux: %s: unrecognized SID %d\n",
3191 __func__, sid);
3192 goto out_unlock;
3193 }
3194
3195 rc = -EINVAL;
3196 context2 = sidtab_search(sidtab, mls_sid);
3197 if (!context2) {
3198 pr_err("SELinux: %s: unrecognized SID %d\n",
3199 __func__, mls_sid);
3200 goto out_unlock;
3201 }
3202
3203 newcon.user = context1->user;
3204 newcon.role = context1->role;
3205 newcon.type = context1->type;
3206 rc = mls_context_cpy(&newcon, context2);
3207 if (rc)
3208 goto out_unlock;
3209
3210 /* Check the validity of the new context. */
3211 if (!policydb_context_isvalid(policydb, &newcon)) {
3212 rc = convert_context_handle_invalid_context(policydb,
3213 &newcon);
3214 if (rc) {
3215 if (!context_struct_to_string(policydb, &newcon, &s,
3216 &len)) {
3217 struct audit_buffer *ab;
3218
3219 ab = audit_log_start(audit_context(),
3220 GFP_ATOMIC,
3221 AUDIT_SELINUX_ERR);
3222 audit_log_format(ab,
3223 "op=security_sid_mls_copy invalid_context=");
3224 /* don't record NUL with untrusted strings */
3225 audit_log_n_untrustedstring(ab, s, len - 1);
3226 audit_log_end(ab);
3227 kfree(s);
3228 }
3229 goto out_unlock;
3230 }
3231 }
3232 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3233 if (rc == -ESTALE) {
3234 rcu_read_unlock();
3235 context_destroy(&newcon);
3236 goto retry;
3237 }
3238out_unlock:
3239 rcu_read_unlock();
3240 context_destroy(&newcon);
3241 return rc;
3242}
3243
3244/**
3245 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3246 * @nlbl_sid: NetLabel SID
3247 * @nlbl_type: NetLabel labeling protocol type
3248 * @xfrm_sid: XFRM SID
3249 * @peer_sid: network peer sid
3250 *
3251 * Description:
3252 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3253 * resolved into a single SID it is returned via @peer_sid and the function
3254 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
3255 * returns a negative value. A table summarizing the behavior is below:
3256 *
3257 * | function return | @sid
3258 * ------------------------------+-----------------+-----------------
3259 * no peer labels | 0 | SECSID_NULL
3260 * single peer label | 0 | <peer_label>
3261 * multiple, consistent labels | 0 | <peer_label>
3262 * multiple, inconsistent labels | -<errno> | SECSID_NULL
3263 *
3264 */
3265int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
3266 u32 xfrm_sid,
3267 u32 *peer_sid)
3268{
3269 struct selinux_policy *policy;
3270 struct policydb *policydb;
3271 struct sidtab *sidtab;
3272 int rc;
3273 struct context *nlbl_ctx;
3274 struct context *xfrm_ctx;
3275
3276 *peer_sid = SECSID_NULL;
3277
3278 /* handle the common (which also happens to be the set of easy) cases
3279 * right away, these two if statements catch everything involving a
3280 * single or absent peer SID/label */
3281 if (xfrm_sid == SECSID_NULL) {
3282 *peer_sid = nlbl_sid;
3283 return 0;
3284 }
3285 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3286 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3287 * is present */
3288 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3289 *peer_sid = xfrm_sid;
3290 return 0;
3291 }
3292
3293 if (!selinux_initialized())
3294 return 0;
3295
3296 rcu_read_lock();
3297 policy = rcu_dereference(selinux_state.policy);
3298 policydb = &policy->policydb;
3299 sidtab = policy->sidtab;
3300
3301 /*
3302 * We don't need to check initialized here since the only way both
3303 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3304 * security server was initialized and state->initialized was true.
3305 */
3306 if (!policydb->mls_enabled) {
3307 rc = 0;
3308 goto out;
3309 }
3310
3311 rc = -EINVAL;
3312 nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3313 if (!nlbl_ctx) {
3314 pr_err("SELinux: %s: unrecognized SID %d\n",
3315 __func__, nlbl_sid);
3316 goto out;
3317 }
3318 rc = -EINVAL;
3319 xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3320 if (!xfrm_ctx) {
3321 pr_err("SELinux: %s: unrecognized SID %d\n",
3322 __func__, xfrm_sid);
3323 goto out;
3324 }
3325 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3326 if (rc)
3327 goto out;
3328
3329 /* at present NetLabel SIDs/labels really only carry MLS
3330 * information so if the MLS portion of the NetLabel SID
3331 * matches the MLS portion of the labeled XFRM SID/label
3332 * then pass along the XFRM SID as it is the most
3333 * expressive */
3334 *peer_sid = xfrm_sid;
3335out:
3336 rcu_read_unlock();
3337 return rc;
3338}
3339
3340static int get_classes_callback(void *k, void *d, void *args)
3341{
3342 struct class_datum *datum = d;
3343 char *name = k, **classes = args;
3344 u32 value = datum->value - 1;
3345
3346 classes[value] = kstrdup(name, GFP_ATOMIC);
3347 if (!classes[value])
3348 return -ENOMEM;
3349
3350 return 0;
3351}
3352
3353int security_get_classes(struct selinux_policy *policy,
3354 char ***classes, u32 *nclasses)
3355{
3356 struct policydb *policydb;
3357 int rc;
3358
3359 policydb = &policy->policydb;
3360
3361 rc = -ENOMEM;
3362 *nclasses = policydb->p_classes.nprim;
3363 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3364 if (!*classes)
3365 goto out;
3366
3367 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3368 *classes);
3369 if (rc) {
3370 u32 i;
3371
3372 for (i = 0; i < *nclasses; i++)
3373 kfree((*classes)[i]);
3374 kfree(*classes);
3375 }
3376
3377out:
3378 return rc;
3379}
3380
3381static int get_permissions_callback(void *k, void *d, void *args)
3382{
3383 struct perm_datum *datum = d;
3384 char *name = k, **perms = args;
3385 u32 value = datum->value - 1;
3386
3387 perms[value] = kstrdup(name, GFP_ATOMIC);
3388 if (!perms[value])
3389 return -ENOMEM;
3390
3391 return 0;
3392}
3393
3394int security_get_permissions(struct selinux_policy *policy,
3395 const char *class, char ***perms, u32 *nperms)
3396{
3397 struct policydb *policydb;
3398 u32 i;
3399 int rc;
3400 struct class_datum *match;
3401
3402 policydb = &policy->policydb;
3403
3404 rc = -EINVAL;
3405 match = symtab_search(&policydb->p_classes, class);
3406 if (!match) {
3407 pr_err("SELinux: %s: unrecognized class %s\n",
3408 __func__, class);
3409 goto out;
3410 }
3411
3412 rc = -ENOMEM;
3413 *nperms = match->permissions.nprim;
3414 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3415 if (!*perms)
3416 goto out;
3417
3418 if (match->comdatum) {
3419 rc = hashtab_map(&match->comdatum->permissions.table,
3420 get_permissions_callback, *perms);
3421 if (rc)
3422 goto err;
3423 }
3424
3425 rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3426 *perms);
3427 if (rc)
3428 goto err;
3429
3430out:
3431 return rc;
3432
3433err:
3434 for (i = 0; i < *nperms; i++)
3435 kfree((*perms)[i]);
3436 kfree(*perms);
3437 return rc;
3438}
3439
3440int security_get_reject_unknown(void)
3441{
3442 struct selinux_policy *policy;
3443 int value;
3444
3445 if (!selinux_initialized())
3446 return 0;
3447
3448 rcu_read_lock();
3449 policy = rcu_dereference(selinux_state.policy);
3450 value = policy->policydb.reject_unknown;
3451 rcu_read_unlock();
3452 return value;
3453}
3454
3455int security_get_allow_unknown(void)
3456{
3457 struct selinux_policy *policy;
3458 int value;
3459
3460 if (!selinux_initialized())
3461 return 0;
3462
3463 rcu_read_lock();
3464 policy = rcu_dereference(selinux_state.policy);
3465 value = policy->policydb.allow_unknown;
3466 rcu_read_unlock();
3467 return value;
3468}
3469
3470/**
3471 * security_policycap_supported - Check for a specific policy capability
3472 * @req_cap: capability
3473 *
3474 * Description:
3475 * This function queries the currently loaded policy to see if it supports the
3476 * capability specified by @req_cap. Returns true (1) if the capability is
3477 * supported, false (0) if it isn't supported.
3478 *
3479 */
3480int security_policycap_supported(unsigned int req_cap)
3481{
3482 struct selinux_policy *policy;
3483 int rc;
3484
3485 if (!selinux_initialized())
3486 return 0;
3487
3488 rcu_read_lock();
3489 policy = rcu_dereference(selinux_state.policy);
3490 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3491 rcu_read_unlock();
3492
3493 return rc;
3494}
3495
3496struct selinux_audit_rule {
3497 u32 au_seqno;
3498 struct context au_ctxt;
3499};
3500
3501void selinux_audit_rule_free(void *vrule)
3502{
3503 struct selinux_audit_rule *rule = vrule;
3504
3505 if (rule) {
3506 context_destroy(&rule->au_ctxt);
3507 kfree(rule);
3508 }
3509}
3510
3511int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3512{
3513 struct selinux_state *state = &selinux_state;
3514 struct selinux_policy *policy;
3515 struct policydb *policydb;
3516 struct selinux_audit_rule *tmprule;
3517 struct role_datum *roledatum;
3518 struct type_datum *typedatum;
3519 struct user_datum *userdatum;
3520 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3521 int rc = 0;
3522
3523 *rule = NULL;
3524
3525 if (!selinux_initialized())
3526 return -EOPNOTSUPP;
3527
3528 switch (field) {
3529 case AUDIT_SUBJ_USER:
3530 case AUDIT_SUBJ_ROLE:
3531 case AUDIT_SUBJ_TYPE:
3532 case AUDIT_OBJ_USER:
3533 case AUDIT_OBJ_ROLE:
3534 case AUDIT_OBJ_TYPE:
3535 /* only 'equals' and 'not equals' fit user, role, and type */
3536 if (op != Audit_equal && op != Audit_not_equal)
3537 return -EINVAL;
3538 break;
3539 case AUDIT_SUBJ_SEN:
3540 case AUDIT_SUBJ_CLR:
3541 case AUDIT_OBJ_LEV_LOW:
3542 case AUDIT_OBJ_LEV_HIGH:
3543 /* we do not allow a range, indicated by the presence of '-' */
3544 if (strchr(rulestr, '-'))
3545 return -EINVAL;
3546 break;
3547 default:
3548 /* only the above fields are valid */
3549 return -EINVAL;
3550 }
3551
3552 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3553 if (!tmprule)
3554 return -ENOMEM;
3555 context_init(&tmprule->au_ctxt);
3556
3557 rcu_read_lock();
3558 policy = rcu_dereference(state->policy);
3559 policydb = &policy->policydb;
3560 tmprule->au_seqno = policy->latest_granting;
3561 switch (field) {
3562 case AUDIT_SUBJ_USER:
3563 case AUDIT_OBJ_USER:
3564 userdatum = symtab_search(&policydb->p_users, rulestr);
3565 if (!userdatum) {
3566 rc = -EINVAL;
3567 goto err;
3568 }
3569 tmprule->au_ctxt.user = userdatum->value;
3570 break;
3571 case AUDIT_SUBJ_ROLE:
3572 case AUDIT_OBJ_ROLE:
3573 roledatum = symtab_search(&policydb->p_roles, rulestr);
3574 if (!roledatum) {
3575 rc = -EINVAL;
3576 goto err;
3577 }
3578 tmprule->au_ctxt.role = roledatum->value;
3579 break;
3580 case AUDIT_SUBJ_TYPE:
3581 case AUDIT_OBJ_TYPE:
3582 typedatum = symtab_search(&policydb->p_types, rulestr);
3583 if (!typedatum) {
3584 rc = -EINVAL;
3585 goto err;
3586 }
3587 tmprule->au_ctxt.type = typedatum->value;
3588 break;
3589 case AUDIT_SUBJ_SEN:
3590 case AUDIT_SUBJ_CLR:
3591 case AUDIT_OBJ_LEV_LOW:
3592 case AUDIT_OBJ_LEV_HIGH:
3593 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3594 GFP_ATOMIC);
3595 if (rc)
3596 goto err;
3597 break;
3598 }
3599 rcu_read_unlock();
3600
3601 *rule = tmprule;
3602 return 0;
3603
3604err:
3605 rcu_read_unlock();
3606 selinux_audit_rule_free(tmprule);
3607 *rule = NULL;
3608 return rc;
3609}
3610
3611/* Check to see if the rule contains any selinux fields */
3612int selinux_audit_rule_known(struct audit_krule *rule)
3613{
3614 u32 i;
3615
3616 for (i = 0; i < rule->field_count; i++) {
3617 struct audit_field *f = &rule->fields[i];
3618 switch (f->type) {
3619 case AUDIT_SUBJ_USER:
3620 case AUDIT_SUBJ_ROLE:
3621 case AUDIT_SUBJ_TYPE:
3622 case AUDIT_SUBJ_SEN:
3623 case AUDIT_SUBJ_CLR:
3624 case AUDIT_OBJ_USER:
3625 case AUDIT_OBJ_ROLE:
3626 case AUDIT_OBJ_TYPE:
3627 case AUDIT_OBJ_LEV_LOW:
3628 case AUDIT_OBJ_LEV_HIGH:
3629 return 1;
3630 }
3631 }
3632
3633 return 0;
3634}
3635
3636int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3637{
3638 struct selinux_state *state = &selinux_state;
3639 struct selinux_policy *policy;
3640 struct context *ctxt;
3641 struct mls_level *level;
3642 struct selinux_audit_rule *rule = vrule;
3643 int match = 0;
3644
3645 if (unlikely(!rule)) {
3646 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3647 return -ENOENT;
3648 }
3649
3650 if (!selinux_initialized())
3651 return 0;
3652
3653 rcu_read_lock();
3654
3655 policy = rcu_dereference(state->policy);
3656
3657 if (rule->au_seqno < policy->latest_granting) {
3658 match = -ESTALE;
3659 goto out;
3660 }
3661
3662 ctxt = sidtab_search(policy->sidtab, sid);
3663 if (unlikely(!ctxt)) {
3664 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3665 sid);
3666 match = -ENOENT;
3667 goto out;
3668 }
3669
3670 /* a field/op pair that is not caught here will simply fall through
3671 without a match */
3672 switch (field) {
3673 case AUDIT_SUBJ_USER:
3674 case AUDIT_OBJ_USER:
3675 switch (op) {
3676 case Audit_equal:
3677 match = (ctxt->user == rule->au_ctxt.user);
3678 break;
3679 case Audit_not_equal:
3680 match = (ctxt->user != rule->au_ctxt.user);
3681 break;
3682 }
3683 break;
3684 case AUDIT_SUBJ_ROLE:
3685 case AUDIT_OBJ_ROLE:
3686 switch (op) {
3687 case Audit_equal:
3688 match = (ctxt->role == rule->au_ctxt.role);
3689 break;
3690 case Audit_not_equal:
3691 match = (ctxt->role != rule->au_ctxt.role);
3692 break;
3693 }
3694 break;
3695 case AUDIT_SUBJ_TYPE:
3696 case AUDIT_OBJ_TYPE:
3697 switch (op) {
3698 case Audit_equal:
3699 match = (ctxt->type == rule->au_ctxt.type);
3700 break;
3701 case Audit_not_equal:
3702 match = (ctxt->type != rule->au_ctxt.type);
3703 break;
3704 }
3705 break;
3706 case AUDIT_SUBJ_SEN:
3707 case AUDIT_SUBJ_CLR:
3708 case AUDIT_OBJ_LEV_LOW:
3709 case AUDIT_OBJ_LEV_HIGH:
3710 level = ((field == AUDIT_SUBJ_SEN ||
3711 field == AUDIT_OBJ_LEV_LOW) ?
3712 &ctxt->range.level[0] : &ctxt->range.level[1]);
3713 switch (op) {
3714 case Audit_equal:
3715 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3716 level);
3717 break;
3718 case Audit_not_equal:
3719 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3720 level);
3721 break;
3722 case Audit_lt:
3723 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3724 level) &&
3725 !mls_level_eq(&rule->au_ctxt.range.level[0],
3726 level));
3727 break;
3728 case Audit_le:
3729 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3730 level);
3731 break;
3732 case Audit_gt:
3733 match = (mls_level_dom(level,
3734 &rule->au_ctxt.range.level[0]) &&
3735 !mls_level_eq(level,
3736 &rule->au_ctxt.range.level[0]));
3737 break;
3738 case Audit_ge:
3739 match = mls_level_dom(level,
3740 &rule->au_ctxt.range.level[0]);
3741 break;
3742 }
3743 }
3744
3745out:
3746 rcu_read_unlock();
3747 return match;
3748}
3749
3750static int aurule_avc_callback(u32 event)
3751{
3752 if (event == AVC_CALLBACK_RESET)
3753 return audit_update_lsm_rules();
3754 return 0;
3755}
3756
3757static int __init aurule_init(void)
3758{
3759 int err;
3760
3761 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3762 if (err)
3763 panic("avc_add_callback() failed, error %d\n", err);
3764
3765 return err;
3766}
3767__initcall(aurule_init);
3768
3769#ifdef CONFIG_NETLABEL
3770/**
3771 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3772 * @secattr: the NetLabel packet security attributes
3773 * @sid: the SELinux SID
3774 *
3775 * Description:
3776 * Attempt to cache the context in @ctx, which was derived from the packet in
3777 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3778 * already been initialized.
3779 *
3780 */
3781static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3782 u32 sid)
3783{
3784 u32 *sid_cache;
3785
3786 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3787 if (sid_cache == NULL)
3788 return;
3789 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3790 if (secattr->cache == NULL) {
3791 kfree(sid_cache);
3792 return;
3793 }
3794
3795 *sid_cache = sid;
3796 secattr->cache->free = kfree;
3797 secattr->cache->data = sid_cache;
3798 secattr->flags |= NETLBL_SECATTR_CACHE;
3799}
3800
3801/**
3802 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3803 * @secattr: the NetLabel packet security attributes
3804 * @sid: the SELinux SID
3805 *
3806 * Description:
3807 * Convert the given NetLabel security attributes in @secattr into a
3808 * SELinux SID. If the @secattr field does not contain a full SELinux
3809 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3810 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3811 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3812 * conversion for future lookups. Returns zero on success, negative values on
3813 * failure.
3814 *
3815 */
3816int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3817 u32 *sid)
3818{
3819 struct selinux_policy *policy;
3820 struct policydb *policydb;
3821 struct sidtab *sidtab;
3822 int rc;
3823 struct context *ctx;
3824 struct context ctx_new;
3825
3826 if (!selinux_initialized()) {
3827 *sid = SECSID_NULL;
3828 return 0;
3829 }
3830
3831retry:
3832 rc = 0;
3833 rcu_read_lock();
3834 policy = rcu_dereference(selinux_state.policy);
3835 policydb = &policy->policydb;
3836 sidtab = policy->sidtab;
3837
3838 if (secattr->flags & NETLBL_SECATTR_CACHE)
3839 *sid = *(u32 *)secattr->cache->data;
3840 else if (secattr->flags & NETLBL_SECATTR_SECID)
3841 *sid = secattr->attr.secid;
3842 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3843 rc = -EIDRM;
3844 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3845 if (ctx == NULL)
3846 goto out;
3847
3848 context_init(&ctx_new);
3849 ctx_new.user = ctx->user;
3850 ctx_new.role = ctx->role;
3851 ctx_new.type = ctx->type;
3852 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3853 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3854 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3855 if (rc)
3856 goto out;
3857 }
3858 rc = -EIDRM;
3859 if (!mls_context_isvalid(policydb, &ctx_new)) {
3860 ebitmap_destroy(&ctx_new.range.level[0].cat);
3861 goto out;
3862 }
3863
3864 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3865 ebitmap_destroy(&ctx_new.range.level[0].cat);
3866 if (rc == -ESTALE) {
3867 rcu_read_unlock();
3868 goto retry;
3869 }
3870 if (rc)
3871 goto out;
3872
3873 security_netlbl_cache_add(secattr, *sid);
3874 } else
3875 *sid = SECSID_NULL;
3876
3877out:
3878 rcu_read_unlock();
3879 return rc;
3880}
3881
3882/**
3883 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3884 * @sid: the SELinux SID
3885 * @secattr: the NetLabel packet security attributes
3886 *
3887 * Description:
3888 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3889 * Returns zero on success, negative values on failure.
3890 *
3891 */
3892int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3893{
3894 struct selinux_policy *policy;
3895 struct policydb *policydb;
3896 int rc;
3897 struct context *ctx;
3898
3899 if (!selinux_initialized())
3900 return 0;
3901
3902 rcu_read_lock();
3903 policy = rcu_dereference(selinux_state.policy);
3904 policydb = &policy->policydb;
3905
3906 rc = -ENOENT;
3907 ctx = sidtab_search(policy->sidtab, sid);
3908 if (ctx == NULL)
3909 goto out;
3910
3911 rc = -ENOMEM;
3912 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3913 GFP_ATOMIC);
3914 if (secattr->domain == NULL)
3915 goto out;
3916
3917 secattr->attr.secid = sid;
3918 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3919 mls_export_netlbl_lvl(policydb, ctx, secattr);
3920 rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3921out:
3922 rcu_read_unlock();
3923 return rc;
3924}
3925#endif /* CONFIG_NETLABEL */
3926
3927/**
3928 * __security_read_policy - read the policy.
3929 * @policy: SELinux policy
3930 * @data: binary policy data
3931 * @len: length of data in bytes
3932 *
3933 */
3934static int __security_read_policy(struct selinux_policy *policy,
3935 void *data, size_t *len)
3936{
3937 int rc;
3938 struct policy_file fp;
3939
3940 fp.data = data;
3941 fp.len = *len;
3942
3943 rc = policydb_write(&policy->policydb, &fp);
3944 if (rc)
3945 return rc;
3946
3947 *len = (unsigned long)fp.data - (unsigned long)data;
3948 return 0;
3949}
3950
3951/**
3952 * security_read_policy - read the policy.
3953 * @data: binary policy data
3954 * @len: length of data in bytes
3955 *
3956 */
3957int security_read_policy(void **data, size_t *len)
3958{
3959 struct selinux_state *state = &selinux_state;
3960 struct selinux_policy *policy;
3961
3962 policy = rcu_dereference_protected(
3963 state->policy, lockdep_is_held(&state->policy_mutex));
3964 if (!policy)
3965 return -EINVAL;
3966
3967 *len = policy->policydb.len;
3968 *data = vmalloc_user(*len);
3969 if (!*data)
3970 return -ENOMEM;
3971
3972 return __security_read_policy(policy, *data, len);
3973}
3974
3975/**
3976 * security_read_state_kernel - read the policy.
3977 * @data: binary policy data
3978 * @len: length of data in bytes
3979 *
3980 * Allocates kernel memory for reading SELinux policy.
3981 * This function is for internal use only and should not
3982 * be used for returning data to user space.
3983 *
3984 * This function must be called with policy_mutex held.
3985 */
3986int security_read_state_kernel(void **data, size_t *len)
3987{
3988 int err;
3989 struct selinux_state *state = &selinux_state;
3990 struct selinux_policy *policy;
3991
3992 policy = rcu_dereference_protected(
3993 state->policy, lockdep_is_held(&state->policy_mutex));
3994 if (!policy)
3995 return -EINVAL;
3996
3997 *len = policy->policydb.len;
3998 *data = vmalloc(*len);
3999 if (!*data)
4000 return -ENOMEM;
4001
4002 err = __security_read_policy(policy, *data, len);
4003 if (err) {
4004 vfree(*data);
4005 *data = NULL;
4006 *len = 0;
4007 }
4008 return err;
4009}