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