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