security/selinux/ss/services.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Implementation of the security services.
   4  *
   5  * Authors : Stephen Smalley, <sds@tycho.nsa.gov>
   6  *           James Morris <jmorris@redhat.com>
   7  *
   8  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
   9  *
  10  *      Support for enhanced MLS infrastructure.
  11  *      Support for context based audit filters.
  12  *
  13  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  14  *
  15  *      Added conditional policy language extensions
  16  *
  17  * Updated: Hewlett-Packard <paul@paul-moore.com>
  18  *
  19  *      Added support for NetLabel
  20  *      Added support for the policy capability bitmap
  21  *
  22  * Updated: Chad Sellers <csellers@tresys.com>
  23  *
  24  *  Added validation of kernel classes and permissions
  25  *
  26  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
  27  *
  28  *  Added support for bounds domain and audit messaged on masked permissions
  29  *
  30  * Updated: Guido Trentalancia <guido@trentalancia.com>
  31  *
  32  *  Added support for runtime switching of the policy type
  33  *
  34  * Copyright (C) 2008, 2009 NEC Corporation
  35  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  36  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  37  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  38  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  39  */
  40 #include <linux/kernel.h>
  41 #include <linux/slab.h>
  42 #include <linux/string.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/rcupdate.h>
  45 #include <linux/errno.h>
  46 #include <linux/in.h>
  47 #include <linux/sched.h>
  48 #include <linux/audit.h>
  49 #include <linux/vmalloc.h>
  50 #include <linux/lsm_hooks.h>
  51 #include <net/netlabel.h>
  52
  53 #include "flask.h"
  54 #include "avc.h"
  55 #include "avc_ss.h"
  56 #include "security.h"
  57 #include "context.h"
  58 #include "policydb.h"
  59 #include "sidtab.h"
  60 #include "services.h"
  61 #include "conditional.h"
  62 #include "mls.h"
  63 #include "objsec.h"
  64 #include "netlabel.h"
  65 #include "xfrm.h"
  66 #include "ebitmap.h"
  67 #include "audit.h"
  68 #include "policycap_names.h"
  69 #include "ima.h"
  70
  71 struct convert_context_args {
  72         struct selinux_state *state;
  73         struct policydb *oldp;
  74         struct policydb *newp;
  75 };
  76
  77 struct selinux_policy_convert_data {
  78         struct convert_context_args args;
  79         struct sidtab_convert_params sidtab_params;
  80 };
  81
  82 /* Forward declaration. */
  83 static int context_struct_to_string(struct policydb *policydb,
  84                                     struct context *context,
  85                                     char **scontext,
  86                                     u32 *scontext_len);
  87
  88 static int sidtab_entry_to_string(struct policydb *policydb,
  89                                   struct sidtab *sidtab,
  90                                   struct sidtab_entry *entry,
  91                                   char **scontext,
  92                                   u32 *scontext_len);
  93
  94 static void context_struct_compute_av(struct policydb *policydb,
  95                                       struct context *scontext,
  96                                       struct context *tcontext,
  97                                       u16 tclass,
  98                                       struct av_decision *avd,
  99                                       struct extended_perms *xperms);
 100
 101 static int selinux_set_mapping(struct policydb *pol,
 102                                const struct security_class_mapping *map,
 103                                struct selinux_map *out_map)
 104 {
 105         u16 i, j;
 106         unsigned k;
 107         bool print_unknown_handle = false;
 108
 109         /* Find number of classes in the input mapping */
 110         if (!map)
 111                 return -EINVAL;
 112         i = 0;
 113         while (map[i].name)
 114                 i++;
 115
 116         /* Allocate space for the class records, plus one for class zero */
 117         out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
 118         if (!out_map->mapping)
 119                 return -ENOMEM;
 120
 121         /* Store the raw class and permission values */
 122         j = 0;
 123         while (map[j].name) {
 124                 const struct security_class_mapping *p_in = map + (j++);
 125                 struct selinux_mapping *p_out = out_map->mapping + j;
 126
 127                 /* An empty class string skips ahead */
 128                 if (!strcmp(p_in->name, "")) {
 129                         p_out->num_perms = 0;
 130                         continue;
 131                 }
 132
 133                 p_out->value = string_to_security_class(pol, p_in->name);
 134                 if (!p_out->value) {
 135                         pr_info("SELinux:  Class %s not defined in policy.\n",
 136                                p_in->name);
 137                         if (pol->reject_unknown)
 138                                 goto err;
 139                         p_out->num_perms = 0;
 140                         print_unknown_handle = true;
 141                         continue;
 142                 }
 143
 144                 k = 0;
 145                 while (p_in->perms[k]) {
 146                         /* An empty permission string skips ahead */
 147                         if (!*p_in->perms[k]) {
 148                                 k++;
 149                                 continue;
 150                         }
 151                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 152                                                             p_in->perms[k]);
 153                         if (!p_out->perms[k]) {
 154                                 pr_info("SELinux:  Permission %s in class %s not defined in policy.\n",
 155                                        p_in->perms[k], p_in->name);
 156                                 if (pol->reject_unknown)
 157                                         goto err;
 158                                 print_unknown_handle = true;
 159                         }
 160
 161                         k++;
 162                 }
 163                 p_out->num_perms = k;
 164         }
 165
 166         if (print_unknown_handle)
 167                 pr_info("SELinux: the above unknown classes and permissions will be %s\n",
 168                        pol->allow_unknown ? "allowed" : "denied");
 169
 170         out_map->size = i;
 171         return 0;
 172 err:
 173         kfree(out_map->mapping);
 174         out_map->mapping = NULL;
 175         return -EINVAL;
 176 }
 177
 178 /*
 179  * Get real, policy values from mapped values
 180  */
 181
 182 static u16 unmap_class(struct selinux_map *map, u16 tclass)
 183 {
 184         if (tclass < map->size)
 185                 return map->mapping[tclass].value;
 186
 187         return tclass;
 188 }
 189
 190 /*
 191  * Get kernel value for class from its policy value
 192  */
 193 static u16 map_class(struct selinux_map *map, u16 pol_value)
 194 {
 195         u16 i;
 196
 197         for (i = 1; i < map->size; i++) {
 198                 if (map->mapping[i].value == pol_value)
 199                         return i;
 200         }
 201
 202         return SECCLASS_NULL;
 203 }
 204
 205 static void map_decision(struct selinux_map *map,
 206                          u16 tclass, struct av_decision *avd,
 207                          int allow_unknown)
 208 {
 209         if (tclass < map->size) {
 210                 struct selinux_mapping *mapping = &map->mapping[tclass];
 211                 unsigned int i, n = mapping->num_perms;
 212                 u32 result;
 213
 214                 for (i = 0, result = 0; i < n; i++) {
 215                         if (avd->allowed & mapping->perms[i])
 216                                 result |= 1<<i;
 217                         if (allow_unknown && !mapping->perms[i])
 218                                 result |= 1<<i;
 219                 }
 220                 avd->allowed = result;
 221
 222                 for (i = 0, result = 0; i < n; i++)
 223                         if (avd->auditallow & mapping->perms[i])
 224                                 result |= 1<<i;
 225                 avd->auditallow = result;
 226
 227                 for (i = 0, result = 0; i < n; i++) {
 228                         if (avd->auditdeny & mapping->perms[i])
 229                                 result |= 1<<i;
 230                         if (!allow_unknown && !mapping->perms[i])
 231                                 result |= 1<<i;
 232                 }
 233                 /*
 234                  * In case the kernel has a bug and requests a permission
 235                  * between num_perms and the maximum permission number, we
 236                  * should audit that denial
 237                  */
 238                 for (; i < (sizeof(u32)*8); i++)
 239                         result |= 1<<i;
 240                 avd->auditdeny = result;
 241         }
 242 }
 243
 244 int security_mls_enabled(struct selinux_state *state)
 245 {
 246         int mls_enabled;
 247         struct selinux_policy *policy;
 248
 249         if (!selinux_initialized(state))
 250                 return 0;
 251
 252         rcu_read_lock();
 253         policy = rcu_dereference(state->policy);
 254         mls_enabled = policy->policydb.mls_enabled;
 255         rcu_read_unlock();
 256         return 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  */
 270 static int constraint_expr_eval(struct policydb *policydb,
 271                                 struct context *scontext,
 272                                 struct context *tcontext,
 273                                 struct context *xcontext,
 274                                 struct constraint_expr *cexpr)
 275 {
 276         u32 val1, val2;
 277         struct context *c;
 278         struct role_datum *r1, *r2;
 279         struct mls_level *l1, *l2;
 280         struct constraint_expr *e;
 281         int s[CEXPR_MAXDEPTH];
 282         int sp = -1;
 283
 284         for (e = cexpr; e; e = e->next) {
 285                 switch (e->expr_type) {
 286                 case CEXPR_NOT:
 287                         BUG_ON(sp < 0);
 288                         s[sp] = !s[sp];
 289                         break;
 290                 case CEXPR_AND:
 291                         BUG_ON(sp < 1);
 292                         sp--;
 293                         s[sp] &= s[sp + 1];
 294                         break;
 295                 case CEXPR_OR:
 296                         BUG_ON(sp < 1);
 297                         sp--;
 298                         s[sp] |= s[sp + 1];
 299                         break;
 300                 case CEXPR_ATTR:
 301                         if (sp == (CEXPR_MAXDEPTH - 1))
 302                                 return 0;
 303                         switch (e->attr) {
 304                         case CEXPR_USER:
 305                                 val1 = scontext->user;
 306                                 val2 = tcontext->user;
 307                                 break;
 308                         case CEXPR_TYPE:
 309                                 val1 = scontext->type;
 310                                 val2 = tcontext->type;
 311                                 break;
 312                         case CEXPR_ROLE:
 313                                 val1 = scontext->role;
 314                                 val2 = tcontext->role;
 315                                 r1 = policydb->role_val_to_struct[val1 - 1];
 316                                 r2 = policydb->role_val_to_struct[val2 - 1];
 317                                 switch (e->op) {
 318                                 case CEXPR_DOM:
 319                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 320                                                                   val2 - 1);
 321                                         continue;
 322                                 case CEXPR_DOMBY:
 323                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 324                                                                   val1 - 1);
 325                                         continue;
 326                                 case CEXPR_INCOMP:
 327                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 328                                                                     val2 - 1) &&
 329                                                    !ebitmap_get_bit(&r2->dominates,
 330                                                                     val1 - 1));
 331                                         continue;
 332                                 default:
 333                                         break;
 334                                 }
 335                                 break;
 336                         case CEXPR_L1L2:
 337                                 l1 = &(scontext->range.level[0]);
 338                                 l2 = &(tcontext->range.level[0]);
 339                                 goto mls_ops;
 340                         case CEXPR_L1H2:
 341                                 l1 = &(scontext->range.level[0]);
 342                                 l2 = &(tcontext->range.level[1]);
 343                                 goto mls_ops;
 344                         case CEXPR_H1L2:
 345                                 l1 = &(scontext->range.level[1]);
 346                                 l2 = &(tcontext->range.level[0]);
 347                                 goto mls_ops;
 348                         case CEXPR_H1H2:
 349                                 l1 = &(scontext->range.level[1]);
 350                                 l2 = &(tcontext->range.level[1]);
 351                                 goto mls_ops;
 352                         case CEXPR_L1H1:
 353                                 l1 = &(scontext->range.level[0]);
 354                                 l2 = &(scontext->range.level[1]);
 355                                 goto mls_ops;
 356                         case CEXPR_L2H2:
 357                                 l1 = &(tcontext->range.level[0]);
 358                                 l2 = &(tcontext->range.level[1]);
 359                                 goto mls_ops;
 360 mls_ops:
 361                                 switch (e->op) {
 362                                 case CEXPR_EQ:
 363                                         s[++sp] = mls_level_eq(l1, l2);
 364                                         continue;
 365                                 case CEXPR_NEQ:
 366                                         s[++sp] = !mls_level_eq(l1, l2);
 367                                         continue;
 368                                 case CEXPR_DOM:
 369                                         s[++sp] = mls_level_dom(l1, l2);
 370                                         continue;
 371                                 case CEXPR_DOMBY:
 372                                         s[++sp] = mls_level_dom(l2, l1);
 373                                         continue;
 374                                 case CEXPR_INCOMP:
 375                                         s[++sp] = mls_level_incomp(l2, l1);
 376                                         continue;
 377                                 default:
 378                                         BUG();
 379                                         return 0;
 380                                 }
 381                                 break;
 382                         default:
 383                                 BUG();
 384                                 return 0;
 385                         }
 386
 387                         switch (e->op) {
 388                         case CEXPR_EQ:
 389                                 s[++sp] = (val1 == val2);
 390                                 break;
 391                         case CEXPR_NEQ:
 392                                 s[++sp] = (val1 != val2);
 393                                 break;
 394                         default:
 395                                 BUG();
 396                                 return 0;
 397                         }
 398                         break;
 399                 case CEXPR_NAMES:
 400                         if (sp == (CEXPR_MAXDEPTH-1))
 401                                 return 0;
 402                         c = scontext;
 403                         if (e->attr & CEXPR_TARGET)
 404                                 c = tcontext;
 405                         else if (e->attr & CEXPR_XTARGET) {
 406                                 c = xcontext;
 407                                 if (!c) {
 408                                         BUG();
 409                                         return 0;
 410                                 }
 411                         }
 412                         if (e->attr & CEXPR_USER)
 413                                 val1 = c->user;
 414                         else if (e->attr & CEXPR_ROLE)
 415                                 val1 = c->role;
 416                         else if (e->attr & CEXPR_TYPE)
 417                                 val1 = c->type;
 418                         else {
 419                                 BUG();
 420                                 return 0;
 421                         }
 422
 423                         switch (e->op) {
 424                         case CEXPR_EQ:
 425                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 426                                 break;
 427                         case CEXPR_NEQ:
 428                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 429                                 break;
 430                         default:
 431                                 BUG();
 432                                 return 0;
 433                         }
 434                         break;
 435                 default:
 436                         BUG();
 437                         return 0;
 438                 }
 439         }
 440
 441         BUG_ON(sp != 0);
 442         return s[0];
 443 }
 444
 445 /*
 446  * security_dump_masked_av - dumps masked permissions during
 447  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 448  */
 449 static int dump_masked_av_helper(void *k, void *d, void *args)
 450 {
 451         struct perm_datum *pdatum = d;
 452         char **permission_names = args;
 453
 454         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 455
 456         permission_names[pdatum->value - 1] = (char *)k;
 457
 458         return 0;
 459 }
 460
 461 static void security_dump_masked_av(struct policydb *policydb,
 462                                     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(policydb, scontext,
 498                                      &scontext_name, &length) < 0)
 499                 goto out;
 500
 501         if (context_struct_to_string(policydb, tcontext,
 502                                      &tcontext_name, &length) < 0)
 503                 goto out;
 504
 505         /* audit a message */
 506         ab = audit_log_start(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);
 528 out:
 529         /* release scontext/tcontext */
 530         kfree(tcontext_name);
 531         kfree(scontext_name);
 532 }
 533
 534 /*
 535  * security_boundary_permission - drops violated permissions
 536  * on boundary constraint.
 537  */
 538 static void type_attribute_bounds_av(struct policydb *policydb,
 539                                      struct context *scontext,
 540                                      struct context *tcontext,
 541                                      u16 tclass,
 542                                      struct av_decision *avd)
 543 {
 544         struct context lo_scontext;
 545         struct context lo_tcontext, *tcontextp = tcontext;
 546         struct av_decision lo_avd;
 547         struct type_datum *source;
 548         struct type_datum *target;
 549         u32 masked = 0;
 550
 551         source = policydb->type_val_to_struct[scontext->type - 1];
 552         BUG_ON(!source);
 553
 554         if (!source->bounds)
 555                 return;
 556
 557         target = policydb->type_val_to_struct[tcontext->type - 1];
 558         BUG_ON(!target);
 559
 560         memset(&lo_avd, 0, sizeof(lo_avd));
 561
 562         memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 563         lo_scontext.type = source->bounds;
 564
 565         if (target->bounds) {
 566                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 567                 lo_tcontext.type = target->bounds;
 568                 tcontextp = &lo_tcontext;
 569         }
 570
 571         context_struct_compute_av(policydb, &lo_scontext,
 572                                   tcontextp,
 573                                   tclass,
 574                                   &lo_avd,
 575                                   NULL);
 576
 577         masked = ~lo_avd.allowed & avd->allowed;
 578
 579         if (likely(!masked))
 580                 return;         /* no masked permission */
 581
 582         /* mask violated permissions */
 583         avd->allowed &= ~masked;
 584
 585         /* audit masked permissions */
 586         security_dump_masked_av(policydb, scontext, tcontext,
 587                                 tclass, masked, "bounds");
 588 }
 589
 590 /*
 591  * flag which drivers have permissions
 592  * only looking for ioctl based extended permssions
 593  */
 594 void services_compute_xperms_drivers(
 595                 struct extended_perms *xperms,
 596                 struct avtab_node *node)
 597 {
 598         unsigned int i;
 599
 600         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 601                 /* if one or more driver has all permissions allowed */
 602                 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
 603                         xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
 604         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 605                 /* if allowing permissions within a driver */
 606                 security_xperm_set(xperms->drivers.p,
 607                                         node->datum.u.xperms->driver);
 608         }
 609
 610         xperms->len = 1;
 611 }
 612
 613 /*
 614  * Compute access vectors and extended permissions based on a context
 615  * structure pair for the permissions in a particular class.
 616  */
 617 static void context_struct_compute_av(struct policydb *policydb,
 618                                       struct context *scontext,
 619                                       struct context *tcontext,
 620                                       u16 tclass,
 621                                       struct av_decision *avd,
 622                                       struct extended_perms *xperms)
 623 {
 624         struct constraint_node *constraint;
 625         struct role_allow *ra;
 626         struct avtab_key avkey;
 627         struct avtab_node *node;
 628         struct class_datum *tclass_datum;
 629         struct ebitmap *sattr, *tattr;
 630         struct ebitmap_node *snode, *tnode;
 631         unsigned int i, j;
 632
 633         avd->allowed = 0;
 634         avd->auditallow = 0;
 635         avd->auditdeny = 0xffffffff;
 636         if (xperms) {
 637                 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
 638                 xperms->len = 0;
 639         }
 640
 641         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
 642                 if (printk_ratelimit())
 643                         pr_warn("SELinux:  Invalid class %hu\n", tclass);
 644                 return;
 645         }
 646
 647         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 648
 649         /*
 650          * If a specific type enforcement rule was defined for
 651          * this permission check, then use it.
 652          */
 653         avkey.target_class = tclass;
 654         avkey.specified = AVTAB_AV | AVTAB_XPERMS;
 655         sattr = &policydb->type_attr_map_array[scontext->type - 1];
 656         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
 657         ebitmap_for_each_positive_bit(sattr, snode, i) {
 658                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 659                         avkey.source_type = i + 1;
 660                         avkey.target_type = j + 1;
 661                         for (node = avtab_search_node(&policydb->te_avtab,
 662                                                       &avkey);
 663                              node;
 664                              node = avtab_search_node_next(node, avkey.specified)) {
 665                                 if (node->key.specified == AVTAB_ALLOWED)
 666                                         avd->allowed |= node->datum.u.data;
 667                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 668                                         avd->auditallow |= node->datum.u.data;
 669                                 else if (node->key.specified == AVTAB_AUDITDENY)
 670                                         avd->auditdeny &= node->datum.u.data;
 671                                 else if (xperms && (node->key.specified & AVTAB_XPERMS))
 672                                         services_compute_xperms_drivers(xperms, node);
 673                         }
 674
 675                         /* Check conditional av table for additional permissions */
 676                         cond_compute_av(&policydb->te_cond_avtab, &avkey,
 677                                         avd, xperms);
 678
 679                 }
 680         }
 681
 682         /*
 683          * Remove any permissions prohibited by a constraint (this includes
 684          * the MLS policy).
 685          */
 686         constraint = tclass_datum->constraints;
 687         while (constraint) {
 688                 if ((constraint->permissions & (avd->allowed)) &&
 689                     !constraint_expr_eval(policydb, scontext, tcontext, NULL,
 690                                           constraint->expr)) {
 691                         avd->allowed &= ~(constraint->permissions);
 692                 }
 693                 constraint = constraint->next;
 694         }
 695
 696         /*
 697          * If checking process transition permission and the
 698          * role is changing, then check the (current_role, new_role)
 699          * pair.
 700          */
 701         if (tclass == policydb->process_class &&
 702             (avd->allowed & policydb->process_trans_perms) &&
 703             scontext->role != tcontext->role) {
 704                 for (ra = policydb->role_allow; ra; ra = ra->next) {
 705                         if (scontext->role == ra->role &&
 706                             tcontext->role == ra->new_role)
 707                                 break;
 708                 }
 709                 if (!ra)
 710                         avd->allowed &= ~policydb->process_trans_perms;
 711         }
 712
 713         /*
 714          * If the given source and target types have boundary
 715          * constraint, lazy checks have to mask any violated
 716          * permission and notice it to userspace via audit.
 717          */
 718         type_attribute_bounds_av(policydb, scontext, tcontext,
 719                                  tclass, avd);
 720 }
 721
 722 static int security_validtrans_handle_fail(struct selinux_state *state,
 723                                         struct selinux_policy *policy,
 724                                         struct sidtab_entry *oentry,
 725                                         struct sidtab_entry *nentry,
 726                                         struct sidtab_entry *tentry,
 727                                         u16 tclass)
 728 {
 729         struct policydb *p = &policy->policydb;
 730         struct sidtab *sidtab = policy->sidtab;
 731         char *o = NULL, *n = NULL, *t = NULL;
 732         u32 olen, nlen, tlen;
 733
 734         if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
 735                 goto out;
 736         if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
 737                 goto out;
 738         if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
 739                 goto out;
 740         audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
 741                   "op=security_validate_transition seresult=denied"
 742                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 743                   o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
 744 out:
 745         kfree(o);
 746         kfree(n);
 747         kfree(t);
 748
 749         if (!enforcing_enabled(state))
 750                 return 0;
 751         return -EPERM;
 752 }
 753
 754 static int security_compute_validatetrans(struct selinux_state *state,
 755                                           u32 oldsid, u32 newsid, u32 tasksid,
 756                                           u16 orig_tclass, bool user)
 757 {
 758         struct selinux_policy *policy;
 759         struct policydb *policydb;
 760         struct sidtab *sidtab;
 761         struct sidtab_entry *oentry;
 762         struct sidtab_entry *nentry;
 763         struct sidtab_entry *tentry;
 764         struct class_datum *tclass_datum;
 765         struct constraint_node *constraint;
 766         u16 tclass;
 767         int rc = 0;
 768
 769
 770         if (!selinux_initialized(state))
 771                 return 0;
 772
 773         rcu_read_lock();
 774
 775         policy = rcu_dereference(state->policy);
 776         policydb = &policy->policydb;
 777         sidtab = policy->sidtab;
 778
 779         if (!user)
 780                 tclass = unmap_class(&policy->map, orig_tclass);
 781         else
 782                 tclass = orig_tclass;
 783
 784         if (!tclass || tclass > policydb->p_classes.nprim) {
 785                 rc = -EINVAL;
 786                 goto out;
 787         }
 788         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 789
 790         oentry = sidtab_search_entry(sidtab, oldsid);
 791         if (!oentry) {
 792                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 793                         __func__, oldsid);
 794                 rc = -EINVAL;
 795                 goto out;
 796         }
 797
 798         nentry = sidtab_search_entry(sidtab, newsid);
 799         if (!nentry) {
 800                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 801                         __func__, newsid);
 802                 rc = -EINVAL;
 803                 goto out;
 804         }
 805
 806         tentry = sidtab_search_entry(sidtab, tasksid);
 807         if (!tentry) {
 808                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 809                         __func__, tasksid);
 810                 rc = -EINVAL;
 811                 goto out;
 812         }
 813
 814         constraint = tclass_datum->validatetrans;
 815         while (constraint) {
 816                 if (!constraint_expr_eval(policydb, &oentry->context,
 817                                           &nentry->context, &tentry->context,
 818                                           constraint->expr)) {
 819                         if (user)
 820                                 rc = -EPERM;
 821                         else
 822                                 rc = security_validtrans_handle_fail(state,
 823                                                                 policy,
 824                                                                 oentry,
 825                                                                 nentry,
 826                                                                 tentry,
 827                                                                 tclass);
 828                         goto out;
 829                 }
 830                 constraint = constraint->next;
 831         }
 832
 833 out:
 834         rcu_read_unlock();
 835         return rc;
 836 }
 837
 838 int security_validate_transition_user(struct selinux_state *state,
 839                                       u32 oldsid, u32 newsid, u32 tasksid,
 840                                       u16 tclass)
 841 {
 842         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 843                                               tclass, true);
 844 }
 845
 846 int security_validate_transition(struct selinux_state *state,
 847                                  u32 oldsid, u32 newsid, u32 tasksid,
 848                                  u16 orig_tclass)
 849 {
 850         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 851                                               orig_tclass, false);
 852 }
 853
 854 /*
 855  * security_bounded_transition - check whether the given
 856  * transition is directed to bounded, or not.
 857  * It returns 0, if @newsid is bounded by @oldsid.
 858  * Otherwise, it returns error code.
 859  *
 860  * @state: SELinux state
 861  * @oldsid : current security identifier
 862  * @newsid : destinated security identifier
 863  */
 864 int security_bounded_transition(struct selinux_state *state,
 865                                 u32 old_sid, u32 new_sid)
 866 {
 867         struct selinux_policy *policy;
 868         struct policydb *policydb;
 869         struct sidtab *sidtab;
 870         struct sidtab_entry *old_entry, *new_entry;
 871         struct type_datum *type;
 872         int index;
 873         int rc;
 874
 875         if (!selinux_initialized(state))
 876                 return 0;
 877
 878         rcu_read_lock();
 879         policy = rcu_dereference(state->policy);
 880         policydb = &policy->policydb;
 881         sidtab = policy->sidtab;
 882
 883         rc = -EINVAL;
 884         old_entry = sidtab_search_entry(sidtab, old_sid);
 885         if (!old_entry) {
 886                 pr_err("SELinux: %s: unrecognized SID %u\n",
 887                        __func__, old_sid);
 888                 goto out;
 889         }
 890
 891         rc = -EINVAL;
 892         new_entry = sidtab_search_entry(sidtab, new_sid);
 893         if (!new_entry) {
 894                 pr_err("SELinux: %s: unrecognized SID %u\n",
 895                        __func__, new_sid);
 896                 goto out;
 897         }
 898
 899         rc = 0;
 900         /* type/domain unchanged */
 901         if (old_entry->context.type == new_entry->context.type)
 902                 goto out;
 903
 904         index = new_entry->context.type;
 905         while (true) {
 906                 type = policydb->type_val_to_struct[index - 1];
 907                 BUG_ON(!type);
 908
 909                 /* not bounded anymore */
 910                 rc = -EPERM;
 911                 if (!type->bounds)
 912                         break;
 913
 914                 /* @newsid is bounded by @oldsid */
 915                 rc = 0;
 916                 if (type->bounds == old_entry->context.type)
 917                         break;
 918
 919                 index = type->bounds;
 920         }
 921
 922         if (rc) {
 923                 char *old_name = NULL;
 924                 char *new_name = NULL;
 925                 u32 length;
 926
 927                 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
 928                                             &old_name, &length) &&
 929                     !sidtab_entry_to_string(policydb, sidtab, new_entry,
 930                                             &new_name, &length)) {
 931                         audit_log(audit_context(),
 932                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 933                                   "op=security_bounded_transition "
 934                                   "seresult=denied "
 935                                   "oldcontext=%s newcontext=%s",
 936                                   old_name, new_name);
 937                 }
 938                 kfree(new_name);
 939                 kfree(old_name);
 940         }
 941 out:
 942         rcu_read_unlock();
 943
 944         return rc;
 945 }
 946
 947 static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
 948 {
 949         avd->allowed = 0;
 950         avd->auditallow = 0;
 951         avd->auditdeny = 0xffffffff;
 952         if (policy)
 953                 avd->seqno = policy->latest_granting;
 954         else
 955                 avd->seqno = 0;
 956         avd->flags = 0;
 957 }
 958
 959 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
 960                                         struct avtab_node *node)
 961 {
 962         unsigned int i;
 963
 964         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 965                 if (xpermd->driver != node->datum.u.xperms->driver)
 966                         return;
 967         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 968                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
 969                                         xpermd->driver))
 970                         return;
 971         } else {
 972                 BUG();
 973         }
 974
 975         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
 976                 xpermd->used |= XPERMS_ALLOWED;
 977                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 978                         memset(xpermd->allowed->p, 0xff,
 979                                         sizeof(xpermd->allowed->p));
 980                 }
 981                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 982                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
 983                                 xpermd->allowed->p[i] |=
 984                                         node->datum.u.xperms->perms.p[i];
 985                 }
 986         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
 987                 xpermd->used |= XPERMS_AUDITALLOW;
 988                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 989                         memset(xpermd->auditallow->p, 0xff,
 990                                         sizeof(xpermd->auditallow->p));
 991                 }
 992                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 993                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
 994                                 xpermd->auditallow->p[i] |=
 995                                         node->datum.u.xperms->perms.p[i];
 996                 }
 997         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
 998                 xpermd->used |= XPERMS_DONTAUDIT;
 999                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
1000                         memset(xpermd->dontaudit->p, 0xff,
1001                                         sizeof(xpermd->dontaudit->p));
1002                 }
1003                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
1004                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
1005                                 xpermd->dontaudit->p[i] |=
1006                                         node->datum.u.xperms->perms.p[i];
1007                 }
1008         } else {
1009                 BUG();
1010         }
1011 }
1012
1013 void security_compute_xperms_decision(struct selinux_state *state,
1014                                       u32 ssid,
1015                                       u32 tsid,
1016                                       u16 orig_tclass,
1017                                       u8 driver,
1018                                       struct extended_perms_decision *xpermd)
1019 {
1020         struct selinux_policy *policy;
1021         struct policydb *policydb;
1022         struct sidtab *sidtab;
1023         u16 tclass;
1024         struct context *scontext, *tcontext;
1025         struct avtab_key avkey;
1026         struct avtab_node *node;
1027         struct ebitmap *sattr, *tattr;
1028         struct ebitmap_node *snode, *tnode;
1029         unsigned int i, j;
1030
1031         xpermd->driver = driver;
1032         xpermd->used = 0;
1033         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1034         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1035         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1036
1037         rcu_read_lock();
1038         if (!selinux_initialized(state))
1039                 goto allow;
1040
1041         policy = rcu_dereference(state->policy);
1042         policydb = &policy->policydb;
1043         sidtab = policy->sidtab;
1044
1045         scontext = sidtab_search(sidtab, ssid);
1046         if (!scontext) {
1047                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1048                        __func__, ssid);
1049                 goto out;
1050         }
1051
1052         tcontext = sidtab_search(sidtab, tsid);
1053         if (!tcontext) {
1054                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1055                        __func__, tsid);
1056                 goto out;
1057         }
1058
1059         tclass = unmap_class(&policy->map, orig_tclass);
1060         if (unlikely(orig_tclass && !tclass)) {
1061                 if (policydb->allow_unknown)
1062                         goto allow;
1063                 goto out;
1064         }
1065
1066
1067         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1068                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1069                 goto out;
1070         }
1071
1072         avkey.target_class = tclass;
1073         avkey.specified = AVTAB_XPERMS;
1074         sattr = &policydb->type_attr_map_array[scontext->type - 1];
1075         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1076         ebitmap_for_each_positive_bit(sattr, snode, i) {
1077                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1078                         avkey.source_type = i + 1;
1079                         avkey.target_type = j + 1;
1080                         for (node = avtab_search_node(&policydb->te_avtab,
1081                                                       &avkey);
1082                              node;
1083                              node = avtab_search_node_next(node, avkey.specified))
1084                                 services_compute_xperms_decision(xpermd, node);
1085
1086                         cond_compute_xperms(&policydb->te_cond_avtab,
1087                                                 &avkey, xpermd);
1088                 }
1089         }
1090 out:
1091         rcu_read_unlock();
1092         return;
1093 allow:
1094         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1095         goto out;
1096 }
1097
1098 /**
1099  * security_compute_av - Compute access vector decisions.
1100  * @state: SELinux state
1101  * @ssid: source security identifier
1102  * @tsid: target security identifier
1103  * @orig_tclass: target security class
1104  * @avd: access vector decisions
1105  * @xperms: extended permissions
1106  *
1107  * Compute a set of access vector decisions based on the
1108  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1109  */
1110 void security_compute_av(struct selinux_state *state,
1111                          u32 ssid,
1112                          u32 tsid,
1113                          u16 orig_tclass,
1114                          struct av_decision *avd,
1115                          struct extended_perms *xperms)
1116 {
1117         struct selinux_policy *policy;
1118         struct policydb *policydb;
1119         struct sidtab *sidtab;
1120         u16 tclass;
1121         struct context *scontext = NULL, *tcontext = NULL;
1122
1123         rcu_read_lock();
1124         policy = rcu_dereference(state->policy);
1125         avd_init(policy, avd);
1126         xperms->len = 0;
1127         if (!selinux_initialized(state))
1128                 goto allow;
1129
1130         policydb = &policy->policydb;
1131         sidtab = policy->sidtab;
1132
1133         scontext = sidtab_search(sidtab, ssid);
1134         if (!scontext) {
1135                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1136                        __func__, ssid);
1137                 goto out;
1138         }
1139
1140         /* permissive domain? */
1141         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1142                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1143
1144         tcontext = sidtab_search(sidtab, tsid);
1145         if (!tcontext) {
1146                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1147                        __func__, tsid);
1148                 goto out;
1149         }
1150
1151         tclass = unmap_class(&policy->map, orig_tclass);
1152         if (unlikely(orig_tclass && !tclass)) {
1153                 if (policydb->allow_unknown)
1154                         goto allow;
1155                 goto out;
1156         }
1157         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1158                                   xperms);
1159         map_decision(&policy->map, orig_tclass, avd,
1160                      policydb->allow_unknown);
1161 out:
1162         rcu_read_unlock();
1163         return;
1164 allow:
1165         avd->allowed = 0xffffffff;
1166         goto out;
1167 }
1168
1169 void security_compute_av_user(struct selinux_state *state,
1170                               u32 ssid,
1171                               u32 tsid,
1172                               u16 tclass,
1173                               struct av_decision *avd)
1174 {
1175         struct selinux_policy *policy;
1176         struct policydb *policydb;
1177         struct sidtab *sidtab;
1178         struct context *scontext = NULL, *tcontext = NULL;
1179
1180         rcu_read_lock();
1181         policy = rcu_dereference(state->policy);
1182         avd_init(policy, avd);
1183         if (!selinux_initialized(state))
1184                 goto allow;
1185
1186         policydb = &policy->policydb;
1187         sidtab = policy->sidtab;
1188
1189         scontext = sidtab_search(sidtab, ssid);
1190         if (!scontext) {
1191                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1192                        __func__, ssid);
1193                 goto out;
1194         }
1195
1196         /* permissive domain? */
1197         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1198                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1199
1200         tcontext = sidtab_search(sidtab, tsid);
1201         if (!tcontext) {
1202                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1203                        __func__, tsid);
1204                 goto out;
1205         }
1206
1207         if (unlikely(!tclass)) {
1208                 if (policydb->allow_unknown)
1209                         goto allow;
1210                 goto out;
1211         }
1212
1213         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1214                                   NULL);
1215  out:
1216         rcu_read_unlock();
1217         return;
1218 allow:
1219         avd->allowed = 0xffffffff;
1220         goto out;
1221 }
1222
1223 /*
1224  * Write the security context string representation of
1225  * the context structure `context' into a dynamically
1226  * allocated string of the correct size.  Set `*scontext'
1227  * to point to this string and set `*scontext_len' to
1228  * the length of the string.
1229  */
1230 static int context_struct_to_string(struct policydb *p,
1231                                     struct context *context,
1232                                     char **scontext, u32 *scontext_len)
1233 {
1234         char *scontextp;
1235
1236         if (scontext)
1237                 *scontext = NULL;
1238         *scontext_len = 0;
1239
1240         if (context->len) {
1241                 *scontext_len = context->len;
1242                 if (scontext) {
1243                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1244                         if (!(*scontext))
1245                                 return -ENOMEM;
1246                 }
1247                 return 0;
1248         }
1249
1250         /* Compute the size of the context. */
1251         *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1252         *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1253         *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1254         *scontext_len += mls_compute_context_len(p, context);
1255
1256         if (!scontext)
1257                 return 0;
1258
1259         /* Allocate space for the context; caller must free this space. */
1260         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1261         if (!scontextp)
1262                 return -ENOMEM;
1263         *scontext = scontextp;
1264
1265         /*
1266          * Copy the user name, role name and type name into the context.
1267          */
1268         scontextp += sprintf(scontextp, "%s:%s:%s",
1269                 sym_name(p, SYM_USERS, context->user - 1),
1270                 sym_name(p, SYM_ROLES, context->role - 1),
1271                 sym_name(p, SYM_TYPES, context->type - 1));
1272
1273         mls_sid_to_context(p, context, &scontextp);
1274
1275         *scontextp = 0;
1276
1277         return 0;
1278 }
1279
1280 static int sidtab_entry_to_string(struct policydb *p,
1281                                   struct sidtab *sidtab,
1282                                   struct sidtab_entry *entry,
1283                                   char **scontext, u32 *scontext_len)
1284 {
1285         int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1286
1287         if (rc != -ENOENT)
1288                 return rc;
1289
1290         rc = context_struct_to_string(p, &entry->context, scontext,
1291                                       scontext_len);
1292         if (!rc && scontext)
1293                 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1294         return rc;
1295 }
1296
1297 #include "initial_sid_to_string.h"
1298
1299 int security_sidtab_hash_stats(struct selinux_state *state, char *page)
1300 {
1301         struct selinux_policy *policy;
1302         int rc;
1303
1304         if (!selinux_initialized(state)) {
1305                 pr_err("SELinux: %s:  called before initial load_policy\n",
1306                        __func__);
1307                 return -EINVAL;
1308         }
1309
1310         rcu_read_lock();
1311         policy = rcu_dereference(state->policy);
1312         rc = sidtab_hash_stats(policy->sidtab, page);
1313         rcu_read_unlock();
1314
1315         return rc;
1316 }
1317
1318 const char *security_get_initial_sid_context(u32 sid)
1319 {
1320         if (unlikely(sid > SECINITSID_NUM))
1321                 return NULL;
1322         return initial_sid_to_string[sid];
1323 }
1324
1325 static int security_sid_to_context_core(struct selinux_state *state,
1326                                         u32 sid, char **scontext,
1327                                         u32 *scontext_len, int force,
1328                                         int only_invalid)
1329 {
1330         struct selinux_policy *policy;
1331         struct policydb *policydb;
1332         struct sidtab *sidtab;
1333         struct sidtab_entry *entry;
1334         int rc = 0;
1335
1336         if (scontext)
1337                 *scontext = NULL;
1338         *scontext_len  = 0;
1339
1340         if (!selinux_initialized(state)) {
1341                 if (sid <= SECINITSID_NUM) {
1342                         char *scontextp;
1343                         const char *s = initial_sid_to_string[sid];
1344
1345                         if (!s)
1346                                 return -EINVAL;
1347                         *scontext_len = strlen(s) + 1;
1348                         if (!scontext)
1349                                 return 0;
1350                         scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1351                         if (!scontextp)
1352                                 return -ENOMEM;
1353                         *scontext = scontextp;
1354                         return 0;
1355                 }
1356                 pr_err("SELinux: %s:  called before initial "
1357                        "load_policy on unknown SID %d\n", __func__, sid);
1358                 return -EINVAL;
1359         }
1360         rcu_read_lock();
1361         policy = rcu_dereference(state->policy);
1362         policydb = &policy->policydb;
1363         sidtab = policy->sidtab;
1364
1365         if (force)
1366                 entry = sidtab_search_entry_force(sidtab, sid);
1367         else
1368                 entry = sidtab_search_entry(sidtab, sid);
1369         if (!entry) {
1370                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1371                         __func__, sid);
1372                 rc = -EINVAL;
1373                 goto out_unlock;
1374         }
1375         if (only_invalid && !entry->context.len)
1376                 goto out_unlock;
1377
1378         rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1379                                     scontext_len);
1380
1381 out_unlock:
1382         rcu_read_unlock();
1383         return rc;
1384
1385 }
1386
1387 /**
1388  * security_sid_to_context - Obtain a context for a given SID.
1389  * @state: SELinux state
1390  * @sid: security identifier, SID
1391  * @scontext: security context
1392  * @scontext_len: length in bytes
1393  *
1394  * Write the string representation of the context associated with @sid
1395  * into a dynamically allocated string of the correct size.  Set @scontext
1396  * to point to this string and set @scontext_len to the length of the string.
1397  */
1398 int security_sid_to_context(struct selinux_state *state,
1399                             u32 sid, char **scontext, u32 *scontext_len)
1400 {
1401         return security_sid_to_context_core(state, sid, scontext,
1402                                             scontext_len, 0, 0);
1403 }
1404
1405 int security_sid_to_context_force(struct selinux_state *state, u32 sid,
1406                                   char **scontext, u32 *scontext_len)
1407 {
1408         return security_sid_to_context_core(state, sid, scontext,
1409                                             scontext_len, 1, 0);
1410 }
1411
1412 /**
1413  * security_sid_to_context_inval - Obtain a context for a given SID if it
1414  *                                 is invalid.
1415  * @state: SELinux state
1416  * @sid: security identifier, SID
1417  * @scontext: security context
1418  * @scontext_len: length in bytes
1419  *
1420  * Write the string representation of the context associated with @sid
1421  * into a dynamically allocated string of the correct size, but only if the
1422  * context is invalid in the current policy.  Set @scontext to point to
1423  * this string (or NULL if the context is valid) and set @scontext_len to
1424  * the length of the string (or 0 if the context is valid).
1425  */
1426 int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
1427                                   char **scontext, u32 *scontext_len)
1428 {
1429         return security_sid_to_context_core(state, sid, scontext,
1430                                             scontext_len, 1, 1);
1431 }
1432
1433 /*
1434  * Caveat:  Mutates scontext.
1435  */
1436 static int string_to_context_struct(struct policydb *pol,
1437                                     struct sidtab *sidtabp,
1438                                     char *scontext,
1439                                     struct context *ctx,
1440                                     u32 def_sid)
1441 {
1442         struct role_datum *role;
1443         struct type_datum *typdatum;
1444         struct user_datum *usrdatum;
1445         char *scontextp, *p, oldc;
1446         int rc = 0;
1447
1448         context_init(ctx);
1449
1450         /* Parse the security context. */
1451
1452         rc = -EINVAL;
1453         scontextp = scontext;
1454
1455         /* Extract the user. */
1456         p = scontextp;
1457         while (*p && *p != ':')
1458                 p++;
1459
1460         if (*p == 0)
1461                 goto out;
1462
1463         *p++ = 0;
1464
1465         usrdatum = symtab_search(&pol->p_users, scontextp);
1466         if (!usrdatum)
1467                 goto out;
1468
1469         ctx->user = usrdatum->value;
1470
1471         /* Extract role. */
1472         scontextp = p;
1473         while (*p && *p != ':')
1474                 p++;
1475
1476         if (*p == 0)
1477                 goto out;
1478
1479         *p++ = 0;
1480
1481         role = symtab_search(&pol->p_roles, scontextp);
1482         if (!role)
1483                 goto out;
1484         ctx->role = role->value;
1485
1486         /* Extract type. */
1487         scontextp = p;
1488         while (*p && *p != ':')
1489                 p++;
1490         oldc = *p;
1491         *p++ = 0;
1492
1493         typdatum = symtab_search(&pol->p_types, scontextp);
1494         if (!typdatum || typdatum->attribute)
1495                 goto out;
1496
1497         ctx->type = typdatum->value;
1498
1499         rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1500         if (rc)
1501                 goto out;
1502
1503         /* Check the validity of the new context. */
1504         rc = -EINVAL;
1505         if (!policydb_context_isvalid(pol, ctx))
1506                 goto out;
1507         rc = 0;
1508 out:
1509         if (rc)
1510                 context_destroy(ctx);
1511         return rc;
1512 }
1513
1514 static int security_context_to_sid_core(struct selinux_state *state,
1515                                         const char *scontext, u32 scontext_len,
1516                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1517                                         int force)
1518 {
1519         struct selinux_policy *policy;
1520         struct policydb *policydb;
1521         struct sidtab *sidtab;
1522         char *scontext2, *str = NULL;
1523         struct context context;
1524         int rc = 0;
1525
1526         /* An empty security context is never valid. */
1527         if (!scontext_len)
1528                 return -EINVAL;
1529
1530         /* Copy the string to allow changes and ensure a NUL terminator */
1531         scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1532         if (!scontext2)
1533                 return -ENOMEM;
1534
1535         if (!selinux_initialized(state)) {
1536                 int i;
1537
1538                 for (i = 1; i < SECINITSID_NUM; i++) {
1539                         const char *s = initial_sid_to_string[i];
1540
1541                         if (s && !strcmp(s, scontext2)) {
1542                                 *sid = i;
1543                                 goto out;
1544                         }
1545                 }
1546                 *sid = SECINITSID_KERNEL;
1547                 goto out;
1548         }
1549         *sid = SECSID_NULL;
1550
1551         if (force) {
1552                 /* Save another copy for storing in uninterpreted form */
1553                 rc = -ENOMEM;
1554                 str = kstrdup(scontext2, gfp_flags);
1555                 if (!str)
1556                         goto out;
1557         }
1558 retry:
1559         rcu_read_lock();
1560         policy = rcu_dereference(state->policy);
1561         policydb = &policy->policydb;
1562         sidtab = policy->sidtab;
1563         rc = string_to_context_struct(policydb, sidtab, scontext2,
1564                                       &context, def_sid);
1565         if (rc == -EINVAL && force) {
1566                 context.str = str;
1567                 context.len = strlen(str) + 1;
1568                 str = NULL;
1569         } else if (rc)
1570                 goto out_unlock;
1571         rc = sidtab_context_to_sid(sidtab, &context, sid);
1572         if (rc == -ESTALE) {
1573                 rcu_read_unlock();
1574                 if (context.str) {
1575                         str = context.str;
1576                         context.str = NULL;
1577                 }
1578                 context_destroy(&context);
1579                 goto retry;
1580         }
1581         context_destroy(&context);
1582 out_unlock:
1583         rcu_read_unlock();
1584 out:
1585         kfree(scontext2);
1586         kfree(str);
1587         return rc;
1588 }
1589
1590 /**
1591  * security_context_to_sid - Obtain a SID for a given security context.
1592  * @state: SELinux state
1593  * @scontext: security context
1594  * @scontext_len: length in bytes
1595  * @sid: security identifier, SID
1596  * @gfp: context for the allocation
1597  *
1598  * Obtains a SID associated with the security context that
1599  * has the string representation specified by @scontext.
1600  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1601  * memory is available, or 0 on success.
1602  */
1603 int security_context_to_sid(struct selinux_state *state,
1604                             const char *scontext, u32 scontext_len, u32 *sid,
1605                             gfp_t gfp)
1606 {
1607         return security_context_to_sid_core(state, scontext, scontext_len,
1608                                             sid, SECSID_NULL, gfp, 0);
1609 }
1610
1611 int security_context_str_to_sid(struct selinux_state *state,
1612                                 const char *scontext, u32 *sid, gfp_t gfp)
1613 {
1614         return security_context_to_sid(state, scontext, strlen(scontext),
1615                                        sid, gfp);
1616 }
1617
1618 /**
1619  * security_context_to_sid_default - Obtain a SID for a given security context,
1620  * falling back to specified default if needed.
1621  *
1622  * @state: SELinux state
1623  * @scontext: security context
1624  * @scontext_len: length in bytes
1625  * @sid: security identifier, SID
1626  * @def_sid: default SID to assign on error
1627  * @gfp_flags: the allocator get-free-page (GFP) flags
1628  *
1629  * Obtains a SID associated with the security context that
1630  * has the string representation specified by @scontext.
1631  * The default SID is passed to the MLS layer to be used to allow
1632  * kernel labeling of the MLS field if the MLS field is not present
1633  * (for upgrading to MLS without full relabel).
1634  * Implicitly forces adding of the context even if it cannot be mapped yet.
1635  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1636  * memory is available, or 0 on success.
1637  */
1638 int security_context_to_sid_default(struct selinux_state *state,
1639                                     const char *scontext, u32 scontext_len,
1640                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1641 {
1642         return security_context_to_sid_core(state, scontext, scontext_len,
1643                                             sid, def_sid, gfp_flags, 1);
1644 }
1645
1646 int security_context_to_sid_force(struct selinux_state *state,
1647                                   const char *scontext, u32 scontext_len,
1648                                   u32 *sid)
1649 {
1650         return security_context_to_sid_core(state, scontext, scontext_len,
1651                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1652 }
1653
1654 static int compute_sid_handle_invalid_context(
1655         struct selinux_state *state,
1656         struct selinux_policy *policy,
1657         struct sidtab_entry *sentry,
1658         struct sidtab_entry *tentry,
1659         u16 tclass,
1660         struct context *newcontext)
1661 {
1662         struct policydb *policydb = &policy->policydb;
1663         struct sidtab *sidtab = policy->sidtab;
1664         char *s = NULL, *t = NULL, *n = NULL;
1665         u32 slen, tlen, nlen;
1666         struct audit_buffer *ab;
1667
1668         if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1669                 goto out;
1670         if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1671                 goto out;
1672         if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1673                 goto out;
1674         ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1675         if (!ab)
1676                 goto out;
1677         audit_log_format(ab,
1678                          "op=security_compute_sid invalid_context=");
1679         /* no need to record the NUL with untrusted strings */
1680         audit_log_n_untrustedstring(ab, n, nlen - 1);
1681         audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1682                          s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1683         audit_log_end(ab);
1684 out:
1685         kfree(s);
1686         kfree(t);
1687         kfree(n);
1688         if (!enforcing_enabled(state))
1689                 return 0;
1690         return -EACCES;
1691 }
1692
1693 static void filename_compute_type(struct policydb *policydb,
1694                                   struct context *newcontext,
1695                                   u32 stype, u32 ttype, u16 tclass,
1696                                   const char *objname)
1697 {
1698         struct filename_trans_key ft;
1699         struct filename_trans_datum *datum;
1700
1701         /*
1702          * Most filename trans rules are going to live in specific directories
1703          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1704          * if the ttype does not contain any rules.
1705          */
1706         if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1707                 return;
1708
1709         ft.ttype = ttype;
1710         ft.tclass = tclass;
1711         ft.name = objname;
1712
1713         datum = policydb_filenametr_search(policydb, &ft);
1714         while (datum) {
1715                 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1716                         newcontext->type = datum->otype;
1717                         return;
1718                 }
1719                 datum = datum->next;
1720         }
1721 }
1722
1723 static int security_compute_sid(struct selinux_state *state,
1724                                 u32 ssid,
1725                                 u32 tsid,
1726                                 u16 orig_tclass,
1727                                 u32 specified,
1728                                 const char *objname,
1729                                 u32 *out_sid,
1730                                 bool kern)
1731 {
1732         struct selinux_policy *policy;
1733         struct policydb *policydb;
1734         struct sidtab *sidtab;
1735         struct class_datum *cladatum;
1736         struct context *scontext, *tcontext, newcontext;
1737         struct sidtab_entry *sentry, *tentry;
1738         struct avtab_key avkey;
1739         struct avtab_datum *avdatum;
1740         struct avtab_node *node;
1741         u16 tclass;
1742         int rc = 0;
1743         bool sock;
1744
1745         if (!selinux_initialized(state)) {
1746                 switch (orig_tclass) {
1747                 case SECCLASS_PROCESS: /* kernel value */
1748                         *out_sid = ssid;
1749                         break;
1750                 default:
1751                         *out_sid = tsid;
1752                         break;
1753                 }
1754                 goto out;
1755         }
1756
1757 retry:
1758         cladatum = NULL;
1759         context_init(&newcontext);
1760
1761         rcu_read_lock();
1762
1763         policy = rcu_dereference(state->policy);
1764
1765         if (kern) {
1766                 tclass = unmap_class(&policy->map, orig_tclass);
1767                 sock = security_is_socket_class(orig_tclass);
1768         } else {
1769                 tclass = orig_tclass;
1770                 sock = security_is_socket_class(map_class(&policy->map,
1771                                                           tclass));
1772         }
1773
1774         policydb = &policy->policydb;
1775         sidtab = policy->sidtab;
1776
1777         sentry = sidtab_search_entry(sidtab, ssid);
1778         if (!sentry) {
1779                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1780                        __func__, ssid);
1781                 rc = -EINVAL;
1782                 goto out_unlock;
1783         }
1784         tentry = sidtab_search_entry(sidtab, tsid);
1785         if (!tentry) {
1786                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1787                        __func__, tsid);
1788                 rc = -EINVAL;
1789                 goto out_unlock;
1790         }
1791
1792         scontext = &sentry->context;
1793         tcontext = &tentry->context;
1794
1795         if (tclass && tclass <= policydb->p_classes.nprim)
1796                 cladatum = policydb->class_val_to_struct[tclass - 1];
1797
1798         /* Set the user identity. */
1799         switch (specified) {
1800         case AVTAB_TRANSITION:
1801         case AVTAB_CHANGE:
1802                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1803                         newcontext.user = tcontext->user;
1804                 } else {
1805                         /* notice this gets both DEFAULT_SOURCE and unset */
1806                         /* Use the process user identity. */
1807                         newcontext.user = scontext->user;
1808                 }
1809                 break;
1810         case AVTAB_MEMBER:
1811                 /* Use the related object owner. */
1812                 newcontext.user = tcontext->user;
1813                 break;
1814         }
1815
1816         /* Set the role to default values. */
1817         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1818                 newcontext.role = scontext->role;
1819         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1820                 newcontext.role = tcontext->role;
1821         } else {
1822                 if ((tclass == policydb->process_class) || sock)
1823                         newcontext.role = scontext->role;
1824                 else
1825                         newcontext.role = OBJECT_R_VAL;
1826         }
1827
1828         /* Set the type to default values. */
1829         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1830                 newcontext.type = scontext->type;
1831         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1832                 newcontext.type = tcontext->type;
1833         } else {
1834                 if ((tclass == policydb->process_class) || sock) {
1835                         /* Use the type of process. */
1836                         newcontext.type = scontext->type;
1837                 } else {
1838                         /* Use the type of the related object. */
1839                         newcontext.type = tcontext->type;
1840                 }
1841         }
1842
1843         /* Look for a type transition/member/change rule. */
1844         avkey.source_type = scontext->type;
1845         avkey.target_type = tcontext->type;
1846         avkey.target_class = tclass;
1847         avkey.specified = specified;
1848         avdatum = avtab_search(&policydb->te_avtab, &avkey);
1849
1850         /* If no permanent rule, also check for enabled conditional rules */
1851         if (!avdatum) {
1852                 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1853                 for (; node; node = avtab_search_node_next(node, specified)) {
1854                         if (node->key.specified & AVTAB_ENABLED) {
1855                                 avdatum = &node->datum;
1856                                 break;
1857                         }
1858                 }
1859         }
1860
1861         if (avdatum) {
1862                 /* Use the type from the type transition/member/change rule. */
1863                 newcontext.type = avdatum->u.data;
1864         }
1865
1866         /* if we have a objname this is a file trans check so check those rules */
1867         if (objname)
1868                 filename_compute_type(policydb, &newcontext, scontext->type,
1869                                       tcontext->type, tclass, objname);
1870
1871         /* Check for class-specific changes. */
1872         if (specified & AVTAB_TRANSITION) {
1873                 /* Look for a role transition rule. */
1874                 struct role_trans_datum *rtd;
1875                 struct role_trans_key rtk = {
1876                         .role = scontext->role,
1877                         .type = tcontext->type,
1878                         .tclass = tclass,
1879                 };
1880
1881                 rtd = policydb_roletr_search(policydb, &rtk);
1882                 if (rtd)
1883                         newcontext.role = rtd->new_role;
1884         }
1885
1886         /* Set the MLS attributes.
1887            This is done last because it may allocate memory. */
1888         rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1889                              &newcontext, sock);
1890         if (rc)
1891                 goto out_unlock;
1892
1893         /* Check the validity of the context. */
1894         if (!policydb_context_isvalid(policydb, &newcontext)) {
1895                 rc = compute_sid_handle_invalid_context(state, policy, sentry,
1896                                                         tentry, tclass,
1897                                                         &newcontext);
1898                 if (rc)
1899                         goto out_unlock;
1900         }
1901         /* Obtain the sid for the context. */
1902         rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1903         if (rc == -ESTALE) {
1904                 rcu_read_unlock();
1905                 context_destroy(&newcontext);
1906                 goto retry;
1907         }
1908 out_unlock:
1909         rcu_read_unlock();
1910         context_destroy(&newcontext);
1911 out:
1912         return rc;
1913 }
1914
1915 /**
1916  * security_transition_sid - Compute the SID for a new subject/object.
1917  * @state: SELinux state
1918  * @ssid: source security identifier
1919  * @tsid: target security identifier
1920  * @tclass: target security class
1921  * @qstr: object name
1922  * @out_sid: security identifier for new subject/object
1923  *
1924  * Compute a SID to use for labeling a new subject or object in the
1925  * class @tclass based on a SID pair (@ssid, @tsid).
1926  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1927  * if insufficient memory is available, or %0 if the new SID was
1928  * computed successfully.
1929  */
1930 int security_transition_sid(struct selinux_state *state,
1931                             u32 ssid, u32 tsid, u16 tclass,
1932                             const struct qstr *qstr, u32 *out_sid)
1933 {
1934         return security_compute_sid(state, ssid, tsid, tclass,
1935                                     AVTAB_TRANSITION,
1936                                     qstr ? qstr->name : NULL, out_sid, true);
1937 }
1938
1939 int security_transition_sid_user(struct selinux_state *state,
1940                                  u32 ssid, u32 tsid, u16 tclass,
1941                                  const char *objname, u32 *out_sid)
1942 {
1943         return security_compute_sid(state, ssid, tsid, tclass,
1944                                     AVTAB_TRANSITION,
1945                                     objname, out_sid, false);
1946 }
1947
1948 /**
1949  * security_member_sid - Compute the SID for member selection.
1950  * @state: SELinux state
1951  * @ssid: source security identifier
1952  * @tsid: target security identifier
1953  * @tclass: target security class
1954  * @out_sid: security identifier for selected member
1955  *
1956  * Compute a SID to use when selecting a member of a polyinstantiated
1957  * object of class @tclass based on a SID pair (@ssid, @tsid).
1958  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1959  * if insufficient memory is available, or %0 if the SID was
1960  * computed successfully.
1961  */
1962 int security_member_sid(struct selinux_state *state,
1963                         u32 ssid,
1964                         u32 tsid,
1965                         u16 tclass,
1966                         u32 *out_sid)
1967 {
1968         return security_compute_sid(state, ssid, tsid, tclass,
1969                                     AVTAB_MEMBER, NULL,
1970                                     out_sid, false);
1971 }
1972
1973 /**
1974  * security_change_sid - Compute the SID for object relabeling.
1975  * @state: SELinux state
1976  * @ssid: source security identifier
1977  * @tsid: target security identifier
1978  * @tclass: target security class
1979  * @out_sid: security identifier for selected member
1980  *
1981  * Compute a SID to use for relabeling an object of class @tclass
1982  * based on a SID pair (@ssid, @tsid).
1983  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1984  * if insufficient memory is available, or %0 if the SID was
1985  * computed successfully.
1986  */
1987 int security_change_sid(struct selinux_state *state,
1988                         u32 ssid,
1989                         u32 tsid,
1990                         u16 tclass,
1991                         u32 *out_sid)
1992 {
1993         return security_compute_sid(state,
1994                                     ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1995                                     out_sid, false);
1996 }
1997
1998 static inline int convert_context_handle_invalid_context(
1999         struct selinux_state *state,
2000         struct policydb *policydb,
2001         struct context *context)
2002 {
2003         char *s;
2004         u32 len;
2005
2006         if (enforcing_enabled(state))
2007                 return -EINVAL;
2008
2009         if (!context_struct_to_string(policydb, context, &s, &len)) {
2010                 pr_warn("SELinux:  Context %s would be invalid if enforcing\n",
2011                         s);
2012                 kfree(s);
2013         }
2014         return 0;
2015 }
2016
2017 /*
2018  * Convert the values in the security context
2019  * structure `oldc' from the values specified
2020  * in the policy `p->oldp' to the values specified
2021  * in the policy `p->newp', storing the new context
2022  * in `newc'.  Verify that the context is valid
2023  * under the new policy.
2024  */
2025 static int convert_context(struct context *oldc, struct context *newc, void *p,
2026                            gfp_t gfp_flags)
2027 {
2028         struct convert_context_args *args;
2029         struct ocontext *oc;
2030         struct role_datum *role;
2031         struct type_datum *typdatum;
2032         struct user_datum *usrdatum;
2033         char *s;
2034         u32 len;
2035         int rc;
2036
2037         args = p;
2038
2039         if (oldc->str) {
2040                 s = kstrdup(oldc->str, gfp_flags);
2041                 if (!s)
2042                         return -ENOMEM;
2043
2044                 rc = string_to_context_struct(args->newp, NULL, s,
2045                                               newc, SECSID_NULL);
2046                 if (rc == -EINVAL) {
2047                         /*
2048                          * Retain string representation for later mapping.
2049                          *
2050                          * IMPORTANT: We need to copy the contents of oldc->str
2051                          * back into s again because string_to_context_struct()
2052                          * may have garbled it.
2053                          */
2054                         memcpy(s, oldc->str, oldc->len);
2055                         context_init(newc);
2056                         newc->str = s;
2057                         newc->len = oldc->len;
2058                         return 0;
2059                 }
2060                 kfree(s);
2061                 if (rc) {
2062                         /* Other error condition, e.g. ENOMEM. */
2063                         pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
2064                                oldc->str, -rc);
2065                         return rc;
2066                 }
2067                 pr_info("SELinux:  Context %s became valid (mapped).\n",
2068                         oldc->str);
2069                 return 0;
2070         }
2071
2072         context_init(newc);
2073
2074         /* Convert the user. */
2075         usrdatum = symtab_search(&args->newp->p_users,
2076                                  sym_name(args->oldp,
2077                                           SYM_USERS, oldc->user - 1));
2078         if (!usrdatum)
2079                 goto bad;
2080         newc->user = usrdatum->value;
2081
2082         /* Convert the role. */
2083         role = symtab_search(&args->newp->p_roles,
2084                              sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2085         if (!role)
2086                 goto bad;
2087         newc->role = role->value;
2088
2089         /* Convert the type. */
2090         typdatum = symtab_search(&args->newp->p_types,
2091                                  sym_name(args->oldp,
2092                                           SYM_TYPES, oldc->type - 1));
2093         if (!typdatum)
2094                 goto bad;
2095         newc->type = typdatum->value;
2096
2097         /* Convert the MLS fields if dealing with MLS policies */
2098         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2099                 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2100                 if (rc)
2101                         goto bad;
2102         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2103                 /*
2104                  * Switching between non-MLS and MLS policy:
2105                  * ensure that the MLS fields of the context for all
2106                  * existing entries in the sidtab are filled in with a
2107                  * suitable default value, likely taken from one of the
2108                  * initial SIDs.
2109                  */
2110                 oc = args->newp->ocontexts[OCON_ISID];
2111                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2112                         oc = oc->next;
2113                 if (!oc) {
2114                         pr_err("SELinux:  unable to look up"
2115                                 " the initial SIDs list\n");
2116                         goto bad;
2117                 }
2118                 rc = mls_range_set(newc, &oc->context[0].range);
2119                 if (rc)
2120                         goto bad;
2121         }
2122
2123         /* Check the validity of the new context. */
2124         if (!policydb_context_isvalid(args->newp, newc)) {
2125                 rc = convert_context_handle_invalid_context(args->state,
2126                                                         args->oldp,
2127                                                         oldc);
2128                 if (rc)
2129                         goto bad;
2130         }
2131
2132         return 0;
2133 bad:
2134         /* Map old representation to string and save it. */
2135         rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2136         if (rc)
2137                 return rc;
2138         context_destroy(newc);
2139         newc->str = s;
2140         newc->len = len;
2141         pr_info("SELinux:  Context %s became invalid (unmapped).\n",
2142                 newc->str);
2143         return 0;
2144 }
2145
2146 static void security_load_policycaps(struct selinux_state *state,
2147                                 struct selinux_policy *policy)
2148 {
2149         struct policydb *p;
2150         unsigned int i;
2151         struct ebitmap_node *node;
2152
2153         p = &policy->policydb;
2154
2155         for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2156                 WRITE_ONCE(state->policycap[i],
2157                         ebitmap_get_bit(&p->policycaps, i));
2158
2159         for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2160                 pr_info("SELinux:  policy capability %s=%d\n",
2161                         selinux_policycap_names[i],
2162                         ebitmap_get_bit(&p->policycaps, i));
2163
2164         ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2165                 if (i >= ARRAY_SIZE(selinux_policycap_names))
2166                         pr_info("SELinux:  unknown policy capability %u\n",
2167                                 i);
2168         }
2169 }
2170
2171 static int security_preserve_bools(struct selinux_policy *oldpolicy,
2172                                 struct selinux_policy *newpolicy);
2173
2174 static void selinux_policy_free(struct selinux_policy *policy)
2175 {
2176         if (!policy)
2177                 return;
2178
2179         sidtab_destroy(policy->sidtab);
2180         kfree(policy->map.mapping);
2181         policydb_destroy(&policy->policydb);
2182         kfree(policy->sidtab);
2183         kfree(policy);
2184 }
2185
2186 static void selinux_policy_cond_free(struct selinux_policy *policy)
2187 {
2188         cond_policydb_destroy_dup(&policy->policydb);
2189         kfree(policy);
2190 }
2191
2192 void selinux_policy_cancel(struct selinux_state *state,
2193                            struct selinux_load_state *load_state)
2194 {
2195         struct selinux_policy *oldpolicy;
2196
2197         oldpolicy = rcu_dereference_protected(state->policy,
2198                                         lockdep_is_held(&state->policy_mutex));
2199
2200         sidtab_cancel_convert(oldpolicy->sidtab);
2201         selinux_policy_free(load_state->policy);
2202         kfree(load_state->convert_data);
2203 }
2204
2205 static void selinux_notify_policy_change(struct selinux_state *state,
2206                                         u32 seqno)
2207 {
2208         /* Flush external caches and notify userspace of policy load */
2209         avc_ss_reset(state->avc, seqno);
2210         selnl_notify_policyload(seqno);
2211         selinux_status_update_policyload(state, seqno);
2212         selinux_netlbl_cache_invalidate();
2213         selinux_xfrm_notify_policyload();
2214         selinux_ima_measure_state_locked(state);
2215 }
2216
2217 void selinux_policy_commit(struct selinux_state *state,
2218                            struct selinux_load_state *load_state)
2219 {
2220         struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
2221         unsigned long flags;
2222         u32 seqno;
2223
2224         oldpolicy = rcu_dereference_protected(state->policy,
2225                                         lockdep_is_held(&state->policy_mutex));
2226
2227         /* If switching between different policy types, log MLS status */
2228         if (oldpolicy) {
2229                 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
2230                         pr_info("SELinux: Disabling MLS support...\n");
2231                 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
2232                         pr_info("SELinux: Enabling MLS support...\n");
2233         }
2234
2235         /* Set latest granting seqno for new policy. */
2236         if (oldpolicy)
2237                 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
2238         else
2239                 newpolicy->latest_granting = 1;
2240         seqno = newpolicy->latest_granting;
2241
2242         /* Install the new policy. */
2243         if (oldpolicy) {
2244                 sidtab_freeze_begin(oldpolicy->sidtab, &flags);
2245                 rcu_assign_pointer(state->policy, newpolicy);
2246                 sidtab_freeze_end(oldpolicy->sidtab, &flags);
2247         } else {
2248                 rcu_assign_pointer(state->policy, newpolicy);
2249         }
2250
2251         /* Load the policycaps from the new policy */
2252         security_load_policycaps(state, newpolicy);
2253
2254         if (!selinux_initialized(state)) {
2255                 /*
2256                  * After first policy load, the security server is
2257                  * marked as initialized and ready to handle requests and
2258                  * any objects created prior to policy load are then labeled.
2259                  */
2260                 selinux_mark_initialized(state);
2261                 selinux_complete_init();
2262         }
2263
2264         /* Free the old policy */
2265         synchronize_rcu();
2266         selinux_policy_free(oldpolicy);
2267         kfree(load_state->convert_data);
2268
2269         /* Notify others of the policy change */
2270         selinux_notify_policy_change(state, seqno);
2271 }
2272
2273 /**
2274  * security_load_policy - Load a security policy configuration.
2275  * @state: SELinux state
2276  * @data: binary policy data
2277  * @len: length of data in bytes
2278  * @load_state: policy load state
2279  *
2280  * Load a new set of security policy configuration data,
2281  * validate it and convert the SID table as necessary.
2282  * This function will flush the access vector cache after
2283  * loading the new policy.
2284  */
2285 int security_load_policy(struct selinux_state *state, void *data, size_t len,
2286                          struct selinux_load_state *load_state)
2287 {
2288         struct selinux_policy *newpolicy, *oldpolicy;
2289         struct selinux_policy_convert_data *convert_data;
2290         int rc = 0;
2291         struct policy_file file = { data, len }, *fp = &file;
2292
2293         newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2294         if (!newpolicy)
2295                 return -ENOMEM;
2296
2297         newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2298         if (!newpolicy->sidtab) {
2299                 rc = -ENOMEM;
2300                 goto err_policy;
2301         }
2302
2303         rc = policydb_read(&newpolicy->policydb, fp);
2304         if (rc)
2305                 goto err_sidtab;
2306
2307         newpolicy->policydb.len = len;
2308         rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2309                                 &newpolicy->map);
2310         if (rc)
2311                 goto err_policydb;
2312
2313         rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2314         if (rc) {
2315                 pr_err("SELinux:  unable to load the initial SIDs\n");
2316                 goto err_mapping;
2317         }
2318
2319         if (!selinux_initialized(state)) {
2320                 /* First policy load, so no need to preserve state from old policy */
2321                 load_state->policy = newpolicy;
2322                 load_state->convert_data = NULL;
2323                 return 0;
2324         }
2325
2326         oldpolicy = rcu_dereference_protected(state->policy,
2327                                         lockdep_is_held(&state->policy_mutex));
2328
2329         /* Preserve active boolean values from the old policy */
2330         rc = security_preserve_bools(oldpolicy, newpolicy);
2331         if (rc) {
2332                 pr_err("SELinux:  unable to preserve booleans\n");
2333                 goto err_free_isids;
2334         }
2335
2336         convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2337         if (!convert_data) {
2338                 rc = -ENOMEM;
2339                 goto err_free_isids;
2340         }
2341
2342         /*
2343          * Convert the internal representations of contexts
2344          * in the new SID table.
2345          */
2346         convert_data->args.state = state;
2347         convert_data->args.oldp = &oldpolicy->policydb;
2348         convert_data->args.newp = &newpolicy->policydb;
2349
2350         convert_data->sidtab_params.func = convert_context;
2351         convert_data->sidtab_params.args = &convert_data->args;
2352         convert_data->sidtab_params.target = newpolicy->sidtab;
2353
2354         rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2355         if (rc) {
2356                 pr_err("SELinux:  unable to convert the internal"
2357                         " representation of contexts in the new SID"
2358                         " table\n");
2359                 goto err_free_convert_data;
2360         }
2361
2362         load_state->policy = newpolicy;
2363         load_state->convert_data = convert_data;
2364         return 0;
2365
2366 err_free_convert_data:
2367         kfree(convert_data);
2368 err_free_isids:
2369         sidtab_destroy(newpolicy->sidtab);
2370 err_mapping:
2371         kfree(newpolicy->map.mapping);
2372 err_policydb:
2373         policydb_destroy(&newpolicy->policydb);
2374 err_sidtab:
2375         kfree(newpolicy->sidtab);
2376 err_policy:
2377         kfree(newpolicy);
2378
2379         return rc;
2380 }
2381
2382 /**
2383  * ocontext_to_sid - Helper to safely get sid for an ocontext
2384  * @sidtab: SID table
2385  * @c: ocontext structure
2386  * @index: index of the context entry (0 or 1)
2387  * @out_sid: pointer to the resulting SID value
2388  *
2389  * For all ocontexts except OCON_ISID the SID fields are populated
2390  * on-demand when needed. Since updating the SID value is an SMP-sensitive
2391  * operation, this helper must be used to do that safely.
2392  *
2393  * WARNING: This function may return -ESTALE, indicating that the caller
2394  * must retry the operation after re-acquiring the policy pointer!
2395  */
2396 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
2397                            size_t index, u32 *out_sid)
2398 {
2399         int rc;
2400         u32 sid;
2401
2402         /* Ensure the associated sidtab entry is visible to this thread. */
2403         sid = smp_load_acquire(&c->sid[index]);
2404         if (!sid) {
2405                 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
2406                 if (rc)
2407                         return rc;
2408
2409                 /*
2410                  * Ensure the new sidtab entry is visible to other threads
2411                  * when they see the SID.
2412                  */
2413                 smp_store_release(&c->sid[index], sid);
2414         }
2415         *out_sid = sid;
2416         return 0;
2417 }
2418
2419 /**
2420  * security_port_sid - Obtain the SID for a port.
2421  * @state: SELinux state
2422  * @protocol: protocol number
2423  * @port: port number
2424  * @out_sid: security identifier
2425  */
2426 int security_port_sid(struct selinux_state *state,
2427                       u8 protocol, u16 port, u32 *out_sid)
2428 {
2429         struct selinux_policy *policy;
2430         struct policydb *policydb;
2431         struct sidtab *sidtab;
2432         struct ocontext *c;
2433         int rc;
2434
2435         if (!selinux_initialized(state)) {
2436                 *out_sid = SECINITSID_PORT;
2437                 return 0;
2438         }
2439
2440 retry:
2441         rc = 0;
2442         rcu_read_lock();
2443         policy = rcu_dereference(state->policy);
2444         policydb = &policy->policydb;
2445         sidtab = policy->sidtab;
2446
2447         c = policydb->ocontexts[OCON_PORT];
2448         while (c) {
2449                 if (c->u.port.protocol == protocol &&
2450                     c->u.port.low_port <= port &&
2451                     c->u.port.high_port >= port)
2452                         break;
2453                 c = c->next;
2454         }
2455
2456         if (c) {
2457                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2458                 if (rc == -ESTALE) {
2459                         rcu_read_unlock();
2460                         goto retry;
2461                 }
2462                 if (rc)
2463                         goto out;
2464         } else {
2465                 *out_sid = SECINITSID_PORT;
2466         }
2467
2468 out:
2469         rcu_read_unlock();
2470         return rc;
2471 }
2472
2473 /**
2474  * security_ib_pkey_sid - Obtain the SID for a pkey.
2475  * @state: SELinux state
2476  * @subnet_prefix: Subnet Prefix
2477  * @pkey_num: pkey number
2478  * @out_sid: security identifier
2479  */
2480 int security_ib_pkey_sid(struct selinux_state *state,
2481                          u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2482 {
2483         struct selinux_policy *policy;
2484         struct policydb *policydb;
2485         struct sidtab *sidtab;
2486         struct ocontext *c;
2487         int rc;
2488
2489         if (!selinux_initialized(state)) {
2490                 *out_sid = SECINITSID_UNLABELED;
2491                 return 0;
2492         }
2493
2494 retry:
2495         rc = 0;
2496         rcu_read_lock();
2497         policy = rcu_dereference(state->policy);
2498         policydb = &policy->policydb;
2499         sidtab = policy->sidtab;
2500
2501         c = policydb->ocontexts[OCON_IBPKEY];
2502         while (c) {
2503                 if (c->u.ibpkey.low_pkey <= pkey_num &&
2504                     c->u.ibpkey.high_pkey >= pkey_num &&
2505                     c->u.ibpkey.subnet_prefix == subnet_prefix)
2506                         break;
2507
2508                 c = c->next;
2509         }
2510
2511         if (c) {
2512                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2513                 if (rc == -ESTALE) {
2514                         rcu_read_unlock();
2515                         goto retry;
2516                 }
2517                 if (rc)
2518                         goto out;
2519         } else
2520                 *out_sid = SECINITSID_UNLABELED;
2521
2522 out:
2523         rcu_read_unlock();
2524         return rc;
2525 }
2526
2527 /**
2528  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2529  * @state: SELinux state
2530  * @dev_name: device name
2531  * @port_num: port number
2532  * @out_sid: security identifier
2533  */
2534 int security_ib_endport_sid(struct selinux_state *state,
2535                             const char *dev_name, u8 port_num, u32 *out_sid)
2536 {
2537         struct selinux_policy *policy;
2538         struct policydb *policydb;
2539         struct sidtab *sidtab;
2540         struct ocontext *c;
2541         int rc;
2542
2543         if (!selinux_initialized(state)) {
2544                 *out_sid = SECINITSID_UNLABELED;
2545                 return 0;
2546         }
2547
2548 retry:
2549         rc = 0;
2550         rcu_read_lock();
2551         policy = rcu_dereference(state->policy);
2552         policydb = &policy->policydb;
2553         sidtab = policy->sidtab;
2554
2555         c = policydb->ocontexts[OCON_IBENDPORT];
2556         while (c) {
2557                 if (c->u.ibendport.port == port_num &&
2558                     !strncmp(c->u.ibendport.dev_name,
2559                              dev_name,
2560                              IB_DEVICE_NAME_MAX))
2561                         break;
2562
2563                 c = c->next;
2564         }
2565
2566         if (c) {
2567                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2568                 if (rc == -ESTALE) {
2569                         rcu_read_unlock();
2570                         goto retry;
2571                 }
2572                 if (rc)
2573                         goto out;
2574         } else
2575                 *out_sid = SECINITSID_UNLABELED;
2576
2577 out:
2578         rcu_read_unlock();
2579         return rc;
2580 }
2581
2582 /**
2583  * security_netif_sid - Obtain the SID for a network interface.
2584  * @state: SELinux state
2585  * @name: interface name
2586  * @if_sid: interface SID
2587  */
2588 int security_netif_sid(struct selinux_state *state,
2589                        char *name, u32 *if_sid)
2590 {
2591         struct selinux_policy *policy;
2592         struct policydb *policydb;
2593         struct sidtab *sidtab;
2594         int rc;
2595         struct ocontext *c;
2596
2597         if (!selinux_initialized(state)) {
2598                 *if_sid = SECINITSID_NETIF;
2599                 return 0;
2600         }
2601
2602 retry:
2603         rc = 0;
2604         rcu_read_lock();
2605         policy = rcu_dereference(state->policy);
2606         policydb = &policy->policydb;
2607         sidtab = policy->sidtab;
2608
2609         c = policydb->ocontexts[OCON_NETIF];
2610         while (c) {
2611                 if (strcmp(name, c->u.name) == 0)
2612                         break;
2613                 c = c->next;
2614         }
2615
2616         if (c) {
2617                 rc = ocontext_to_sid(sidtab, c, 0, if_sid);
2618                 if (rc == -ESTALE) {
2619                         rcu_read_unlock();
2620                         goto retry;
2621                 }
2622                 if (rc)
2623                         goto out;
2624         } else
2625                 *if_sid = SECINITSID_NETIF;
2626
2627 out:
2628         rcu_read_unlock();
2629         return rc;
2630 }
2631
2632 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2633 {
2634         int i, fail = 0;
2635
2636         for (i = 0; i < 4; i++)
2637                 if (addr[i] != (input[i] & mask[i])) {
2638                         fail = 1;
2639                         break;
2640                 }
2641
2642         return !fail;
2643 }
2644
2645 /**
2646  * security_node_sid - Obtain the SID for a node (host).
2647  * @state: SELinux state
2648  * @domain: communication domain aka address family
2649  * @addrp: address
2650  * @addrlen: address length in bytes
2651  * @out_sid: security identifier
2652  */
2653 int security_node_sid(struct selinux_state *state,
2654                       u16 domain,
2655                       void *addrp,
2656                       u32 addrlen,
2657                       u32 *out_sid)
2658 {
2659         struct selinux_policy *policy;
2660         struct policydb *policydb;
2661         struct sidtab *sidtab;
2662         int rc;
2663         struct ocontext *c;
2664
2665         if (!selinux_initialized(state)) {
2666                 *out_sid = SECINITSID_NODE;
2667                 return 0;
2668         }
2669
2670 retry:
2671         rcu_read_lock();
2672         policy = rcu_dereference(state->policy);
2673         policydb = &policy->policydb;
2674         sidtab = policy->sidtab;
2675
2676         switch (domain) {
2677         case AF_INET: {
2678                 u32 addr;
2679
2680                 rc = -EINVAL;
2681                 if (addrlen != sizeof(u32))
2682                         goto out;
2683
2684                 addr = *((u32 *)addrp);
2685
2686                 c = policydb->ocontexts[OCON_NODE];
2687                 while (c) {
2688                         if (c->u.node.addr == (addr & c->u.node.mask))
2689                                 break;
2690                         c = c->next;
2691                 }
2692                 break;
2693         }
2694
2695         case AF_INET6:
2696                 rc = -EINVAL;
2697                 if (addrlen != sizeof(u64) * 2)
2698                         goto out;
2699                 c = policydb->ocontexts[OCON_NODE6];
2700                 while (c) {
2701                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2702                                                 c->u.node6.mask))
2703                                 break;
2704                         c = c->next;
2705                 }
2706                 break;
2707
2708         default:
2709                 rc = 0;
2710                 *out_sid = SECINITSID_NODE;
2711                 goto out;
2712         }
2713
2714         if (c) {
2715                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2716                 if (rc == -ESTALE) {
2717                         rcu_read_unlock();
2718                         goto retry;
2719                 }
2720                 if (rc)
2721                         goto out;
2722         } else {
2723                 *out_sid = SECINITSID_NODE;
2724         }
2725
2726         rc = 0;
2727 out:
2728         rcu_read_unlock();
2729         return rc;
2730 }
2731
2732 #define SIDS_NEL 25
2733
2734 /**
2735  * security_get_user_sids - Obtain reachable SIDs for a user.
2736  * @state: SELinux state
2737  * @fromsid: starting SID
2738  * @username: username
2739  * @sids: array of reachable SIDs for user
2740  * @nel: number of elements in @sids
2741  *
2742  * Generate the set of SIDs for legal security contexts
2743  * for a given user that can be reached by @fromsid.
2744  * Set *@sids to point to a dynamically allocated
2745  * array containing the set of SIDs.  Set *@nel to the
2746  * number of elements in the array.
2747  */
2748
2749 int security_get_user_sids(struct selinux_state *state,
2750                            u32 fromsid,
2751                            char *username,
2752                            u32 **sids,
2753                            u32 *nel)
2754 {
2755         struct selinux_policy *policy;
2756         struct policydb *policydb;
2757         struct sidtab *sidtab;
2758         struct context *fromcon, usercon;
2759         u32 *mysids = NULL, *mysids2, sid;
2760         u32 i, j, mynel, maxnel = SIDS_NEL;
2761         struct user_datum *user;
2762         struct role_datum *role;
2763         struct ebitmap_node *rnode, *tnode;
2764         int rc;
2765
2766         *sids = NULL;
2767         *nel = 0;
2768
2769         if (!selinux_initialized(state))
2770                 return 0;
2771
2772         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2773         if (!mysids)
2774                 return -ENOMEM;
2775
2776 retry:
2777         mynel = 0;
2778         rcu_read_lock();
2779         policy = rcu_dereference(state->policy);
2780         policydb = &policy->policydb;
2781         sidtab = policy->sidtab;
2782
2783         context_init(&usercon);
2784
2785         rc = -EINVAL;
2786         fromcon = sidtab_search(sidtab, fromsid);
2787         if (!fromcon)
2788                 goto out_unlock;
2789
2790         rc = -EINVAL;
2791         user = symtab_search(&policydb->p_users, username);
2792         if (!user)
2793                 goto out_unlock;
2794
2795         usercon.user = user->value;
2796
2797         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2798                 role = policydb->role_val_to_struct[i];
2799                 usercon.role = i + 1;
2800                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2801                         usercon.type = j + 1;
2802
2803                         if (mls_setup_user_range(policydb, fromcon, user,
2804                                                  &usercon))
2805                                 continue;
2806
2807                         rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2808                         if (rc == -ESTALE) {
2809                                 rcu_read_unlock();
2810                                 goto retry;
2811                         }
2812                         if (rc)
2813                                 goto out_unlock;
2814                         if (mynel < maxnel) {
2815                                 mysids[mynel++] = sid;
2816                         } else {
2817                                 rc = -ENOMEM;
2818                                 maxnel += SIDS_NEL;
2819                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2820                                 if (!mysids2)
2821                                         goto out_unlock;
2822                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2823                                 kfree(mysids);
2824                                 mysids = mysids2;
2825                                 mysids[mynel++] = sid;
2826                         }
2827                 }
2828         }
2829         rc = 0;
2830 out_unlock:
2831         rcu_read_unlock();
2832         if (rc || !mynel) {
2833                 kfree(mysids);
2834                 return rc;
2835         }
2836
2837         rc = -ENOMEM;
2838         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2839         if (!mysids2) {
2840                 kfree(mysids);
2841                 return rc;
2842         }
2843         for (i = 0, j = 0; i < mynel; i++) {
2844                 struct av_decision dummy_avd;
2845                 rc = avc_has_perm_noaudit(state,
2846                                           fromsid, mysids[i],
2847                                           SECCLASS_PROCESS, /* kernel value */
2848                                           PROCESS__TRANSITION, AVC_STRICT,
2849                                           &dummy_avd);
2850                 if (!rc)
2851                         mysids2[j++] = mysids[i];
2852                 cond_resched();
2853         }
2854         kfree(mysids);
2855         *sids = mysids2;
2856         *nel = j;
2857         return 0;
2858 }
2859
2860 /**
2861  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2862  * @policy: policy
2863  * @fstype: filesystem type
2864  * @path: path from root of mount
2865  * @orig_sclass: file security class
2866  * @sid: SID for path
2867  *
2868  * Obtain a SID to use for a file in a filesystem that
2869  * cannot support xattr or use a fixed labeling behavior like
2870  * transition SIDs or task SIDs.
2871  *
2872  * WARNING: This function may return -ESTALE, indicating that the caller
2873  * must retry the operation after re-acquiring the policy pointer!
2874  */
2875 static inline int __security_genfs_sid(struct selinux_policy *policy,
2876                                        const char *fstype,
2877                                        const char *path,
2878                                        u16 orig_sclass,
2879                                        u32 *sid)
2880 {
2881         struct policydb *policydb = &policy->policydb;
2882         struct sidtab *sidtab = policy->sidtab;
2883         int len;
2884         u16 sclass;
2885         struct genfs *genfs;
2886         struct ocontext *c;
2887         int cmp = 0;
2888
2889         while (path[0] == '/' && path[1] == '/')
2890                 path++;
2891
2892         sclass = unmap_class(&policy->map, orig_sclass);
2893         *sid = SECINITSID_UNLABELED;
2894
2895         for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2896                 cmp = strcmp(fstype, genfs->fstype);
2897                 if (cmp <= 0)
2898                         break;
2899         }
2900
2901         if (!genfs || cmp)
2902                 return -ENOENT;
2903
2904         for (c = genfs->head; c; c = c->next) {
2905                 len = strlen(c->u.name);
2906                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2907                     (strncmp(c->u.name, path, len) == 0))
2908                         break;
2909         }
2910
2911         if (!c)
2912                 return -ENOENT;
2913
2914         return ocontext_to_sid(sidtab, c, 0, sid);
2915 }
2916
2917 /**
2918  * security_genfs_sid - Obtain a SID for a file in a filesystem
2919  * @state: SELinux state
2920  * @fstype: filesystem type
2921  * @path: path from root of mount
2922  * @orig_sclass: file security class
2923  * @sid: SID for path
2924  *
2925  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2926  * it afterward.
2927  */
2928 int security_genfs_sid(struct selinux_state *state,
2929                        const char *fstype,
2930                        const char *path,
2931                        u16 orig_sclass,
2932                        u32 *sid)
2933 {
2934         struct selinux_policy *policy;
2935         int retval;
2936
2937         if (!selinux_initialized(state)) {
2938                 *sid = SECINITSID_UNLABELED;
2939                 return 0;
2940         }
2941
2942         do {
2943                 rcu_read_lock();
2944                 policy = rcu_dereference(state->policy);
2945                 retval = __security_genfs_sid(policy, fstype, path,
2946                                               orig_sclass, sid);
2947                 rcu_read_unlock();
2948         } while (retval == -ESTALE);
2949         return retval;
2950 }
2951
2952 int selinux_policy_genfs_sid(struct selinux_policy *policy,
2953                         const char *fstype,
2954                         const char *path,
2955                         u16 orig_sclass,
2956                         u32 *sid)
2957 {
2958         /* no lock required, policy is not yet accessible by other threads */
2959         return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2960 }
2961
2962 /**
2963  * security_fs_use - Determine how to handle labeling for a filesystem.
2964  * @state: SELinux state
2965  * @sb: superblock in question
2966  */
2967 int security_fs_use(struct selinux_state *state, struct super_block *sb)
2968 {
2969         struct selinux_policy *policy;
2970         struct policydb *policydb;
2971         struct sidtab *sidtab;
2972         int rc;
2973         struct ocontext *c;
2974         struct superblock_security_struct *sbsec = selinux_superblock(sb);
2975         const char *fstype = sb->s_type->name;
2976
2977         if (!selinux_initialized(state)) {
2978                 sbsec->behavior = SECURITY_FS_USE_NONE;
2979                 sbsec->sid = SECINITSID_UNLABELED;
2980                 return 0;
2981         }
2982
2983 retry:
2984         rcu_read_lock();
2985         policy = rcu_dereference(state->policy);
2986         policydb = &policy->policydb;
2987         sidtab = policy->sidtab;
2988
2989         c = policydb->ocontexts[OCON_FSUSE];
2990         while (c) {
2991                 if (strcmp(fstype, c->u.name) == 0)
2992                         break;
2993                 c = c->next;
2994         }
2995
2996         if (c) {
2997                 sbsec->behavior = c->v.behavior;
2998                 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
2999                 if (rc == -ESTALE) {
3000                         rcu_read_unlock();
3001                         goto retry;
3002                 }
3003                 if (rc)
3004                         goto out;
3005         } else {
3006                 rc = __security_genfs_sid(policy, fstype, "/",
3007                                         SECCLASS_DIR, &sbsec->sid);
3008                 if (rc == -ESTALE) {
3009                         rcu_read_unlock();
3010                         goto retry;
3011                 }
3012                 if (rc) {
3013                         sbsec->behavior = SECURITY_FS_USE_NONE;
3014                         rc = 0;
3015                 } else {
3016                         sbsec->behavior = SECURITY_FS_USE_GENFS;
3017                 }
3018         }
3019
3020 out:
3021         rcu_read_unlock();
3022         return rc;
3023 }
3024
3025 int security_get_bools(struct selinux_policy *policy,
3026                        u32 *len, char ***names, int **values)
3027 {
3028         struct policydb *policydb;
3029         u32 i;
3030         int rc;
3031
3032         policydb = &policy->policydb;
3033
3034         *names = NULL;
3035         *values = NULL;
3036
3037         rc = 0;
3038         *len = policydb->p_bools.nprim;
3039         if (!*len)
3040                 goto out;
3041
3042         rc = -ENOMEM;
3043         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
3044         if (!*names)
3045                 goto err;
3046
3047         rc = -ENOMEM;
3048         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
3049         if (!*values)
3050                 goto err;
3051
3052         for (i = 0; i < *len; i++) {
3053                 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3054
3055                 rc = -ENOMEM;
3056                 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3057                                       GFP_ATOMIC);
3058                 if (!(*names)[i])
3059                         goto err;
3060         }
3061         rc = 0;
3062 out:
3063         return rc;
3064 err:
3065         if (*names) {
3066                 for (i = 0; i < *len; i++)
3067                         kfree((*names)[i]);
3068                 kfree(*names);
3069         }
3070         kfree(*values);
3071         *len = 0;
3072         *names = NULL;
3073         *values = NULL;
3074         goto out;
3075 }
3076
3077
3078 int security_set_bools(struct selinux_state *state, u32 len, int *values)
3079 {
3080         struct selinux_policy *newpolicy, *oldpolicy;
3081         int rc;
3082         u32 i, seqno = 0;
3083
3084         if (!selinux_initialized(state))
3085                 return -EINVAL;
3086
3087         oldpolicy = rcu_dereference_protected(state->policy,
3088                                         lockdep_is_held(&state->policy_mutex));
3089
3090         /* Consistency check on number of booleans, should never fail */
3091         if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3092                 return -EINVAL;
3093
3094         newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3095         if (!newpolicy)
3096                 return -ENOMEM;
3097
3098         /*
3099          * Deep copy only the parts of the policydb that might be
3100          * modified as a result of changing booleans.
3101          */
3102         rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3103         if (rc) {
3104                 kfree(newpolicy);
3105                 return -ENOMEM;
3106         }
3107
3108         /* Update the boolean states in the copy */
3109         for (i = 0; i < len; i++) {
3110                 int new_state = !!values[i];
3111                 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3112
3113                 if (new_state != old_state) {
3114                         audit_log(audit_context(), GFP_ATOMIC,
3115                                 AUDIT_MAC_CONFIG_CHANGE,
3116                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3117                                 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3118                                 new_state,
3119                                 old_state,
3120                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3121                                 audit_get_sessionid(current));
3122                         newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3123                 }
3124         }
3125
3126         /* Re-evaluate the conditional rules in the copy */
3127         evaluate_cond_nodes(&newpolicy->policydb);
3128
3129         /* Set latest granting seqno for new policy */
3130         newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3131         seqno = newpolicy->latest_granting;
3132
3133         /* Install the new policy */
3134         rcu_assign_pointer(state->policy, newpolicy);
3135
3136         /*
3137          * Free the conditional portions of the old policydb
3138          * that were copied for the new policy, and the oldpolicy
3139          * structure itself but not what it references.
3140          */
3141         synchronize_rcu();
3142         selinux_policy_cond_free(oldpolicy);
3143
3144         /* Notify others of the policy change */
3145         selinux_notify_policy_change(state, seqno);
3146         return 0;
3147 }
3148
3149 int security_get_bool_value(struct selinux_state *state,
3150                             u32 index)
3151 {
3152         struct selinux_policy *policy;
3153         struct policydb *policydb;
3154         int rc;
3155         u32 len;
3156
3157         if (!selinux_initialized(state))
3158                 return 0;
3159
3160         rcu_read_lock();
3161         policy = rcu_dereference(state->policy);
3162         policydb = &policy->policydb;
3163
3164         rc = -EFAULT;
3165         len = policydb->p_bools.nprim;
3166         if (index >= len)
3167                 goto out;
3168
3169         rc = policydb->bool_val_to_struct[index]->state;
3170 out:
3171         rcu_read_unlock();
3172         return rc;
3173 }
3174
3175 static int security_preserve_bools(struct selinux_policy *oldpolicy,
3176                                 struct selinux_policy *newpolicy)
3177 {
3178         int rc, *bvalues = NULL;
3179         char **bnames = NULL;
3180         struct cond_bool_datum *booldatum;
3181         u32 i, nbools = 0;
3182
3183         rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3184         if (rc)
3185                 goto out;
3186         for (i = 0; i < nbools; i++) {
3187                 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3188                                         bnames[i]);
3189                 if (booldatum)
3190                         booldatum->state = bvalues[i];
3191         }
3192         evaluate_cond_nodes(&newpolicy->policydb);
3193
3194 out:
3195         if (bnames) {
3196                 for (i = 0; i < nbools; i++)
3197                         kfree(bnames[i]);
3198         }
3199         kfree(bnames);
3200         kfree(bvalues);
3201         return rc;
3202 }
3203
3204 /*
3205  * security_sid_mls_copy() - computes a new sid based on the given
3206  * sid and the mls portion of mls_sid.
3207  */
3208 int security_sid_mls_copy(struct selinux_state *state,
3209                           u32 sid, u32 mls_sid, u32 *new_sid)
3210 {
3211         struct selinux_policy *policy;
3212         struct policydb *policydb;
3213         struct sidtab *sidtab;
3214         struct context *context1;
3215         struct context *context2;
3216         struct context newcon;
3217         char *s;
3218         u32 len;
3219         int rc;
3220
3221         if (!selinux_initialized(state)) {
3222                 *new_sid = sid;
3223                 return 0;
3224         }
3225
3226 retry:
3227         rc = 0;
3228         context_init(&newcon);
3229
3230         rcu_read_lock();
3231         policy = rcu_dereference(state->policy);
3232         policydb = &policy->policydb;
3233         sidtab = policy->sidtab;
3234
3235         if (!policydb->mls_enabled) {
3236                 *new_sid = sid;
3237                 goto out_unlock;
3238         }
3239
3240         rc = -EINVAL;
3241         context1 = sidtab_search(sidtab, sid);
3242         if (!context1) {
3243                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3244                         __func__, sid);
3245                 goto out_unlock;
3246         }
3247
3248         rc = -EINVAL;
3249         context2 = sidtab_search(sidtab, mls_sid);
3250         if (!context2) {
3251                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3252                         __func__, mls_sid);
3253                 goto out_unlock;
3254         }
3255
3256         newcon.user = context1->user;
3257         newcon.role = context1->role;
3258         newcon.type = context1->type;
3259         rc = mls_context_cpy(&newcon, context2);
3260         if (rc)
3261                 goto out_unlock;
3262
3263         /* Check the validity of the new context. */
3264         if (!policydb_context_isvalid(policydb, &newcon)) {
3265                 rc = convert_context_handle_invalid_context(state, policydb,
3266                                                         &newcon);
3267                 if (rc) {
3268                         if (!context_struct_to_string(policydb, &newcon, &s,
3269                                                       &len)) {
3270                                 struct audit_buffer *ab;
3271
3272                                 ab = audit_log_start(audit_context(),
3273                                                      GFP_ATOMIC,
3274                                                      AUDIT_SELINUX_ERR);
3275                                 audit_log_format(ab,
3276                                                  "op=security_sid_mls_copy invalid_context=");
3277                                 /* don't record NUL with untrusted strings */
3278                                 audit_log_n_untrustedstring(ab, s, len - 1);
3279                                 audit_log_end(ab);
3280                                 kfree(s);
3281                         }
3282                         goto out_unlock;
3283                 }
3284         }
3285         rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3286         if (rc == -ESTALE) {
3287                 rcu_read_unlock();
3288                 context_destroy(&newcon);
3289                 goto retry;
3290         }
3291 out_unlock:
3292         rcu_read_unlock();
3293         context_destroy(&newcon);
3294         return rc;
3295 }
3296
3297 /**
3298  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3299  * @state: SELinux state
3300  * @nlbl_sid: NetLabel SID
3301  * @nlbl_type: NetLabel labeling protocol type
3302  * @xfrm_sid: XFRM SID
3303  * @peer_sid: network peer sid
3304  *
3305  * Description:
3306  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3307  * resolved into a single SID it is returned via @peer_sid and the function
3308  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
3309  * returns a negative value.  A table summarizing the behavior is below:
3310  *
3311  *                                 | function return |      @sid
3312  *   ------------------------------+-----------------+-----------------
3313  *   no peer labels                |        0        |    SECSID_NULL
3314  *   single peer label             |        0        |    <peer_label>
3315  *   multiple, consistent labels   |        0        |    <peer_label>
3316  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
3317  *
3318  */
3319 int security_net_peersid_resolve(struct selinux_state *state,
3320                                  u32 nlbl_sid, u32 nlbl_type,
3321                                  u32 xfrm_sid,
3322                                  u32 *peer_sid)
3323 {
3324         struct selinux_policy *policy;
3325         struct policydb *policydb;
3326         struct sidtab *sidtab;
3327         int rc;
3328         struct context *nlbl_ctx;
3329         struct context *xfrm_ctx;
3330
3331         *peer_sid = SECSID_NULL;
3332
3333         /* handle the common (which also happens to be the set of easy) cases
3334          * right away, these two if statements catch everything involving a
3335          * single or absent peer SID/label */
3336         if (xfrm_sid == SECSID_NULL) {
3337                 *peer_sid = nlbl_sid;
3338                 return 0;
3339         }
3340         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3341          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3342          * is present */
3343         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3344                 *peer_sid = xfrm_sid;
3345                 return 0;
3346         }
3347
3348         if (!selinux_initialized(state))
3349                 return 0;
3350
3351         rcu_read_lock();
3352         policy = rcu_dereference(state->policy);
3353         policydb = &policy->policydb;
3354         sidtab = policy->sidtab;
3355
3356         /*
3357          * We don't need to check initialized here since the only way both
3358          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3359          * security server was initialized and state->initialized was true.
3360          */
3361         if (!policydb->mls_enabled) {
3362                 rc = 0;
3363                 goto out;
3364         }
3365
3366         rc = -EINVAL;
3367         nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3368         if (!nlbl_ctx) {
3369                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3370                        __func__, nlbl_sid);
3371                 goto out;
3372         }
3373         rc = -EINVAL;
3374         xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3375         if (!xfrm_ctx) {
3376                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3377                        __func__, xfrm_sid);
3378                 goto out;
3379         }
3380         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3381         if (rc)
3382                 goto out;
3383
3384         /* at present NetLabel SIDs/labels really only carry MLS
3385          * information so if the MLS portion of the NetLabel SID
3386          * matches the MLS portion of the labeled XFRM SID/label
3387          * then pass along the XFRM SID as it is the most
3388          * expressive */
3389         *peer_sid = xfrm_sid;
3390 out:
3391         rcu_read_unlock();
3392         return rc;
3393 }
3394
3395 static int get_classes_callback(void *k, void *d, void *args)
3396 {
3397         struct class_datum *datum = d;
3398         char *name = k, **classes = args;
3399         int value = datum->value - 1;
3400
3401         classes[value] = kstrdup(name, GFP_ATOMIC);
3402         if (!classes[value])
3403                 return -ENOMEM;
3404
3405         return 0;
3406 }
3407
3408 int security_get_classes(struct selinux_policy *policy,
3409                          char ***classes, int *nclasses)
3410 {
3411         struct policydb *policydb;
3412         int rc;
3413
3414         policydb = &policy->policydb;
3415
3416         rc = -ENOMEM;
3417         *nclasses = policydb->p_classes.nprim;
3418         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3419         if (!*classes)
3420                 goto out;
3421
3422         rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3423                          *classes);
3424         if (rc) {
3425                 int i;
3426                 for (i = 0; i < *nclasses; i++)
3427                         kfree((*classes)[i]);
3428                 kfree(*classes);
3429         }
3430
3431 out:
3432         return rc;
3433 }
3434
3435 static int get_permissions_callback(void *k, void *d, void *args)
3436 {
3437         struct perm_datum *datum = d;
3438         char *name = k, **perms = args;
3439         int value = datum->value - 1;
3440
3441         perms[value] = kstrdup(name, GFP_ATOMIC);
3442         if (!perms[value])
3443                 return -ENOMEM;
3444
3445         return 0;
3446 }
3447
3448 int security_get_permissions(struct selinux_policy *policy,
3449                              char *class, char ***perms, int *nperms)
3450 {
3451         struct policydb *policydb;
3452         int rc, i;
3453         struct class_datum *match;
3454
3455         policydb = &policy->policydb;
3456
3457         rc = -EINVAL;
3458         match = symtab_search(&policydb->p_classes, class);
3459         if (!match) {
3460                 pr_err("SELinux: %s:  unrecognized class %s\n",
3461                         __func__, class);
3462                 goto out;
3463         }
3464
3465         rc = -ENOMEM;
3466         *nperms = match->permissions.nprim;
3467         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3468         if (!*perms)
3469                 goto out;
3470
3471         if (match->comdatum) {
3472                 rc = hashtab_map(&match->comdatum->permissions.table,
3473                                  get_permissions_callback, *perms);
3474                 if (rc)
3475                         goto err;
3476         }
3477
3478         rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3479                          *perms);
3480         if (rc)
3481                 goto err;
3482
3483 out:
3484         return rc;
3485
3486 err:
3487         for (i = 0; i < *nperms; i++)
3488                 kfree((*perms)[i]);
3489         kfree(*perms);
3490         return rc;
3491 }
3492
3493 int security_get_reject_unknown(struct selinux_state *state)
3494 {
3495         struct selinux_policy *policy;
3496         int value;
3497
3498         if (!selinux_initialized(state))
3499                 return 0;
3500
3501         rcu_read_lock();
3502         policy = rcu_dereference(state->policy);
3503         value = policy->policydb.reject_unknown;
3504         rcu_read_unlock();
3505         return value;
3506 }
3507
3508 int security_get_allow_unknown(struct selinux_state *state)
3509 {
3510         struct selinux_policy *policy;
3511         int value;
3512
3513         if (!selinux_initialized(state))
3514                 return 0;
3515
3516         rcu_read_lock();
3517         policy = rcu_dereference(state->policy);
3518         value = policy->policydb.allow_unknown;
3519         rcu_read_unlock();
3520         return value;
3521 }
3522
3523 /**
3524  * security_policycap_supported - Check for a specific policy capability
3525  * @state: SELinux state
3526  * @req_cap: capability
3527  *
3528  * Description:
3529  * This function queries the currently loaded policy to see if it supports the
3530  * capability specified by @req_cap.  Returns true (1) if the capability is
3531  * supported, false (0) if it isn't supported.
3532  *
3533  */
3534 int security_policycap_supported(struct selinux_state *state,
3535                                  unsigned int req_cap)
3536 {
3537         struct selinux_policy *policy;
3538         int rc;
3539
3540         if (!selinux_initialized(state))
3541                 return 0;
3542
3543         rcu_read_lock();
3544         policy = rcu_dereference(state->policy);
3545         rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3546         rcu_read_unlock();
3547
3548         return rc;
3549 }
3550
3551 struct selinux_audit_rule {
3552         u32 au_seqno;
3553         struct context au_ctxt;
3554 };
3555
3556 void selinux_audit_rule_free(void *vrule)
3557 {
3558         struct selinux_audit_rule *rule = vrule;
3559
3560         if (rule) {
3561                 context_destroy(&rule->au_ctxt);
3562                 kfree(rule);
3563         }
3564 }
3565
3566 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3567 {
3568         struct selinux_state *state = &selinux_state;
3569         struct selinux_policy *policy;
3570         struct policydb *policydb;
3571         struct selinux_audit_rule *tmprule;
3572         struct role_datum *roledatum;
3573         struct type_datum *typedatum;
3574         struct user_datum *userdatum;
3575         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3576         int rc = 0;
3577
3578         *rule = NULL;
3579
3580         if (!selinux_initialized(state))
3581                 return -EOPNOTSUPP;
3582
3583         switch (field) {
3584         case AUDIT_SUBJ_USER:
3585         case AUDIT_SUBJ_ROLE:
3586         case AUDIT_SUBJ_TYPE:
3587         case AUDIT_OBJ_USER:
3588         case AUDIT_OBJ_ROLE:
3589         case AUDIT_OBJ_TYPE:
3590                 /* only 'equals' and 'not equals' fit user, role, and type */
3591                 if (op != Audit_equal && op != Audit_not_equal)
3592                         return -EINVAL;
3593                 break;
3594         case AUDIT_SUBJ_SEN:
3595         case AUDIT_SUBJ_CLR:
3596         case AUDIT_OBJ_LEV_LOW:
3597         case AUDIT_OBJ_LEV_HIGH:
3598                 /* we do not allow a range, indicated by the presence of '-' */
3599                 if (strchr(rulestr, '-'))
3600                         return -EINVAL;
3601                 break;
3602         default:
3603                 /* only the above fields are valid */
3604                 return -EINVAL;
3605         }
3606
3607         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3608         if (!tmprule)
3609                 return -ENOMEM;
3610
3611         context_init(&tmprule->au_ctxt);
3612
3613         rcu_read_lock();
3614         policy = rcu_dereference(state->policy);
3615         policydb = &policy->policydb;
3616
3617         tmprule->au_seqno = policy->latest_granting;
3618
3619         switch (field) {
3620         case AUDIT_SUBJ_USER:
3621         case AUDIT_OBJ_USER:
3622                 rc = -EINVAL;
3623                 userdatum = symtab_search(&policydb->p_users, rulestr);
3624                 if (!userdatum)
3625                         goto out;
3626                 tmprule->au_ctxt.user = userdatum->value;
3627                 break;
3628         case AUDIT_SUBJ_ROLE:
3629         case AUDIT_OBJ_ROLE:
3630                 rc = -EINVAL;
3631                 roledatum = symtab_search(&policydb->p_roles, rulestr);
3632                 if (!roledatum)
3633                         goto out;
3634                 tmprule->au_ctxt.role = roledatum->value;
3635                 break;
3636         case AUDIT_SUBJ_TYPE:
3637         case AUDIT_OBJ_TYPE:
3638                 rc = -EINVAL;
3639                 typedatum = symtab_search(&policydb->p_types, rulestr);
3640                 if (!typedatum)
3641                         goto out;
3642                 tmprule->au_ctxt.type = typedatum->value;
3643                 break;
3644         case AUDIT_SUBJ_SEN:
3645         case AUDIT_SUBJ_CLR:
3646         case AUDIT_OBJ_LEV_LOW:
3647         case AUDIT_OBJ_LEV_HIGH:
3648                 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3649                                      GFP_ATOMIC);
3650                 if (rc)
3651                         goto out;
3652                 break;
3653         }
3654         rc = 0;
3655 out:
3656         rcu_read_unlock();
3657
3658         if (rc) {
3659                 selinux_audit_rule_free(tmprule);
3660                 tmprule = NULL;
3661         }
3662
3663         *rule = tmprule;
3664
3665         return rc;
3666 }
3667
3668 /* Check to see if the rule contains any selinux fields */
3669 int selinux_audit_rule_known(struct audit_krule *rule)
3670 {
3671         int i;
3672
3673         for (i = 0; i < rule->field_count; i++) {
3674                 struct audit_field *f = &rule->fields[i];
3675                 switch (f->type) {
3676                 case AUDIT_SUBJ_USER:
3677                 case AUDIT_SUBJ_ROLE:
3678                 case AUDIT_SUBJ_TYPE:
3679                 case AUDIT_SUBJ_SEN:
3680                 case AUDIT_SUBJ_CLR:
3681                 case AUDIT_OBJ_USER:
3682                 case AUDIT_OBJ_ROLE:
3683                 case AUDIT_OBJ_TYPE:
3684                 case AUDIT_OBJ_LEV_LOW:
3685                 case AUDIT_OBJ_LEV_HIGH:
3686                         return 1;
3687                 }
3688         }
3689
3690         return 0;
3691 }
3692
3693 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3694 {
3695         struct selinux_state *state = &selinux_state;
3696         struct selinux_policy *policy;
3697         struct context *ctxt;
3698         struct mls_level *level;
3699         struct selinux_audit_rule *rule = vrule;
3700         int match = 0;
3701
3702         if (unlikely(!rule)) {
3703                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3704                 return -ENOENT;
3705         }
3706
3707         if (!selinux_initialized(state))
3708                 return 0;
3709
3710         rcu_read_lock();
3711
3712         policy = rcu_dereference(state->policy);
3713
3714         if (rule->au_seqno < policy->latest_granting) {
3715                 match = -ESTALE;
3716                 goto out;
3717         }
3718
3719         ctxt = sidtab_search(policy->sidtab, sid);
3720         if (unlikely(!ctxt)) {
3721                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3722                           sid);
3723                 match = -ENOENT;
3724                 goto out;
3725         }
3726
3727         /* a field/op pair that is not caught here will simply fall through
3728            without a match */
3729         switch (field) {
3730         case AUDIT_SUBJ_USER:
3731         case AUDIT_OBJ_USER:
3732                 switch (op) {
3733                 case Audit_equal:
3734                         match = (ctxt->user == rule->au_ctxt.user);
3735                         break;
3736                 case Audit_not_equal:
3737                         match = (ctxt->user != rule->au_ctxt.user);
3738                         break;
3739                 }
3740                 break;
3741         case AUDIT_SUBJ_ROLE:
3742         case AUDIT_OBJ_ROLE:
3743                 switch (op) {
3744                 case Audit_equal:
3745                         match = (ctxt->role == rule->au_ctxt.role);
3746                         break;
3747                 case Audit_not_equal:
3748                         match = (ctxt->role != rule->au_ctxt.role);
3749                         break;
3750                 }
3751                 break;
3752         case AUDIT_SUBJ_TYPE:
3753         case AUDIT_OBJ_TYPE:
3754                 switch (op) {
3755                 case Audit_equal:
3756                         match = (ctxt->type == rule->au_ctxt.type);
3757                         break;
3758                 case Audit_not_equal:
3759                         match = (ctxt->type != rule->au_ctxt.type);
3760                         break;
3761                 }
3762                 break;
3763         case AUDIT_SUBJ_SEN:
3764         case AUDIT_SUBJ_CLR:
3765         case AUDIT_OBJ_LEV_LOW:
3766         case AUDIT_OBJ_LEV_HIGH:
3767                 level = ((field == AUDIT_SUBJ_SEN ||
3768                           field == AUDIT_OBJ_LEV_LOW) ?
3769                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3770                 switch (op) {
3771                 case Audit_equal:
3772                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3773                                              level);
3774                         break;
3775                 case Audit_not_equal:
3776                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3777                                               level);
3778                         break;
3779                 case Audit_lt:
3780                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3781                                                level) &&
3782                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3783                                                level));
3784                         break;
3785                 case Audit_le:
3786                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3787                                               level);
3788                         break;
3789                 case Audit_gt:
3790                         match = (mls_level_dom(level,
3791                                               &rule->au_ctxt.range.level[0]) &&
3792                                  !mls_level_eq(level,
3793                                                &rule->au_ctxt.range.level[0]));
3794                         break;
3795                 case Audit_ge:
3796                         match = mls_level_dom(level,
3797                                               &rule->au_ctxt.range.level[0]);
3798                         break;
3799                 }
3800         }
3801
3802 out:
3803         rcu_read_unlock();
3804         return match;
3805 }
3806
3807 static int aurule_avc_callback(u32 event)
3808 {
3809         if (event == AVC_CALLBACK_RESET)
3810                 return audit_update_lsm_rules();
3811         return 0;
3812 }
3813
3814 static int __init aurule_init(void)
3815 {
3816         int err;
3817
3818         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3819         if (err)
3820                 panic("avc_add_callback() failed, error %d\n", err);
3821
3822         return err;
3823 }
3824 __initcall(aurule_init);
3825
3826 #ifdef CONFIG_NETLABEL
3827 /**
3828  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3829  * @secattr: the NetLabel packet security attributes
3830  * @sid: the SELinux SID
3831  *
3832  * Description:
3833  * Attempt to cache the context in @ctx, which was derived from the packet in
3834  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3835  * already been initialized.
3836  *
3837  */
3838 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3839                                       u32 sid)
3840 {
3841         u32 *sid_cache;
3842
3843         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3844         if (sid_cache == NULL)
3845                 return;
3846         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3847         if (secattr->cache == NULL) {
3848                 kfree(sid_cache);
3849                 return;
3850         }
3851
3852         *sid_cache = sid;
3853         secattr->cache->free = kfree;
3854         secattr->cache->data = sid_cache;
3855         secattr->flags |= NETLBL_SECATTR_CACHE;
3856 }
3857
3858 /**
3859  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3860  * @state: SELinux state
3861  * @secattr: the NetLabel packet security attributes
3862  * @sid: the SELinux SID
3863  *
3864  * Description:
3865  * Convert the given NetLabel security attributes in @secattr into a
3866  * SELinux SID.  If the @secattr field does not contain a full SELinux
3867  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3868  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3869  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3870  * conversion for future lookups.  Returns zero on success, negative values on
3871  * failure.
3872  *
3873  */
3874 int security_netlbl_secattr_to_sid(struct selinux_state *state,
3875                                    struct netlbl_lsm_secattr *secattr,
3876                                    u32 *sid)
3877 {
3878         struct selinux_policy *policy;
3879         struct policydb *policydb;
3880         struct sidtab *sidtab;
3881         int rc;
3882         struct context *ctx;
3883         struct context ctx_new;
3884
3885         if (!selinux_initialized(state)) {
3886                 *sid = SECSID_NULL;
3887                 return 0;
3888         }
3889
3890 retry:
3891         rc = 0;
3892         rcu_read_lock();
3893         policy = rcu_dereference(state->policy);
3894         policydb = &policy->policydb;
3895         sidtab = policy->sidtab;
3896
3897         if (secattr->flags & NETLBL_SECATTR_CACHE)
3898                 *sid = *(u32 *)secattr->cache->data;
3899         else if (secattr->flags & NETLBL_SECATTR_SECID)
3900                 *sid = secattr->attr.secid;
3901         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3902                 rc = -EIDRM;
3903                 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3904                 if (ctx == NULL)
3905                         goto out;
3906
3907                 context_init(&ctx_new);
3908                 ctx_new.user = ctx->user;
3909                 ctx_new.role = ctx->role;
3910                 ctx_new.type = ctx->type;
3911                 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3912                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3913                         rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3914                         if (rc)
3915                                 goto out;
3916                 }
3917                 rc = -EIDRM;
3918                 if (!mls_context_isvalid(policydb, &ctx_new)) {
3919                         ebitmap_destroy(&ctx_new.range.level[0].cat);
3920                         goto out;
3921                 }
3922
3923                 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3924                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3925                 if (rc == -ESTALE) {
3926                         rcu_read_unlock();
3927                         goto retry;
3928                 }
3929                 if (rc)
3930                         goto out;
3931
3932                 security_netlbl_cache_add(secattr, *sid);
3933         } else
3934                 *sid = SECSID_NULL;
3935
3936 out:
3937         rcu_read_unlock();
3938         return rc;
3939 }
3940
3941 /**
3942  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3943  * @state: SELinux state
3944  * @sid: the SELinux SID
3945  * @secattr: the NetLabel packet security attributes
3946  *
3947  * Description:
3948  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3949  * Returns zero on success, negative values on failure.
3950  *
3951  */
3952 int security_netlbl_sid_to_secattr(struct selinux_state *state,
3953                                    u32 sid, struct netlbl_lsm_secattr *secattr)
3954 {
3955         struct selinux_policy *policy;
3956         struct policydb *policydb;
3957         int rc;
3958         struct context *ctx;
3959
3960         if (!selinux_initialized(state))
3961                 return 0;
3962
3963         rcu_read_lock();
3964         policy = rcu_dereference(state->policy);
3965         policydb = &policy->policydb;
3966
3967         rc = -ENOENT;
3968         ctx = sidtab_search(policy->sidtab, sid);
3969         if (ctx == NULL)
3970                 goto out;
3971
3972         rc = -ENOMEM;
3973         secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3974                                   GFP_ATOMIC);
3975         if (secattr->domain == NULL)
3976                 goto out;
3977
3978         secattr->attr.secid = sid;
3979         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3980         mls_export_netlbl_lvl(policydb, ctx, secattr);
3981         rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3982 out:
3983         rcu_read_unlock();
3984         return rc;
3985 }
3986 #endif /* CONFIG_NETLABEL */
3987
3988 /**
3989  * __security_read_policy - read the policy.
3990  * @policy: SELinux policy
3991  * @data: binary policy data
3992  * @len: length of data in bytes
3993  *
3994  */
3995 static int __security_read_policy(struct selinux_policy *policy,
3996                                   void *data, size_t *len)
3997 {
3998         int rc;
3999         struct policy_file fp;
4000
4001         fp.data = data;
4002         fp.len = *len;
4003
4004         rc = policydb_write(&policy->policydb, &fp);
4005         if (rc)
4006                 return rc;
4007
4008         *len = (unsigned long)fp.data - (unsigned long)data;
4009         return 0;
4010 }
4011
4012 /**
4013  * security_read_policy - read the policy.
4014  * @state: selinux_state
4015  * @data: binary policy data
4016  * @len: length of data in bytes
4017  *
4018  */
4019 int security_read_policy(struct selinux_state *state,
4020                          void **data, size_t *len)
4021 {
4022         struct selinux_policy *policy;
4023
4024         policy = rcu_dereference_protected(
4025                         state->policy, lockdep_is_held(&state->policy_mutex));
4026         if (!policy)
4027                 return -EINVAL;
4028
4029         *len = policy->policydb.len;
4030         *data = vmalloc_user(*len);
4031         if (!*data)
4032                 return -ENOMEM;
4033
4034         return __security_read_policy(policy, *data, len);
4035 }
4036
4037 /**
4038  * security_read_state_kernel - read the policy.
4039  * @state: selinux_state
4040  * @data: binary policy data
4041  * @len: length of data in bytes
4042  *
4043  * Allocates kernel memory for reading SELinux policy.
4044  * This function is for internal use only and should not
4045  * be used for returning data to user space.
4046  *
4047  * This function must be called with policy_mutex held.
4048  */
4049 int security_read_state_kernel(struct selinux_state *state,
4050                                void **data, size_t *len)
4051 {
4052         int err;
4053         struct selinux_policy *policy;
4054
4055         policy = rcu_dereference_protected(
4056                         state->policy, lockdep_is_held(&state->policy_mutex));
4057         if (!policy)
4058                 return -EINVAL;
4059
4060         *len = policy->policydb.len;
4061         *data = vmalloc(*len);
4062         if (!*data)
4063                 return -ENOMEM;
4064
4065         err = __security_read_policy(policy, *data, len);
4066         if (err) {
4067                 vfree(*data);
4068                 *data = NULL;
4069                 *len = 0;
4070         }
4071         return err;
4072 }