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