security/tomoyo/file.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * security/tomoyo/file.c
   4  *
   5  * Copyright (C) 2005-2011  NTT DATA CORPORATION
   6  */
   7
   8 #include "common.h"
   9 #include <linux/slab.h>
  10
  11 /*
  12  * Mapping table from "enum tomoyo_path_acl_index" to "enum tomoyo_mac_index".
  13  */
  14 static const u8 tomoyo_p2mac[TOMOYO_MAX_PATH_OPERATION] = {
  15         [TOMOYO_TYPE_EXECUTE]    = TOMOYO_MAC_FILE_EXECUTE,
  16         [TOMOYO_TYPE_READ]       = TOMOYO_MAC_FILE_OPEN,
  17         [TOMOYO_TYPE_WRITE]      = TOMOYO_MAC_FILE_OPEN,
  18         [TOMOYO_TYPE_APPEND]     = TOMOYO_MAC_FILE_OPEN,
  19         [TOMOYO_TYPE_UNLINK]     = TOMOYO_MAC_FILE_UNLINK,
  20         [TOMOYO_TYPE_GETATTR]    = TOMOYO_MAC_FILE_GETATTR,
  21         [TOMOYO_TYPE_RMDIR]      = TOMOYO_MAC_FILE_RMDIR,
  22         [TOMOYO_TYPE_TRUNCATE]   = TOMOYO_MAC_FILE_TRUNCATE,
  23         [TOMOYO_TYPE_SYMLINK]    = TOMOYO_MAC_FILE_SYMLINK,
  24         [TOMOYO_TYPE_CHROOT]     = TOMOYO_MAC_FILE_CHROOT,
  25         [TOMOYO_TYPE_UMOUNT]     = TOMOYO_MAC_FILE_UMOUNT,
  26 };
  27
  28 /*
  29  * Mapping table from "enum tomoyo_mkdev_acl_index" to "enum tomoyo_mac_index".
  30  */
  31 const u8 tomoyo_pnnn2mac[TOMOYO_MAX_MKDEV_OPERATION] = {
  32         [TOMOYO_TYPE_MKBLOCK] = TOMOYO_MAC_FILE_MKBLOCK,
  33         [TOMOYO_TYPE_MKCHAR]  = TOMOYO_MAC_FILE_MKCHAR,
  34 };
  35
  36 /*
  37  * Mapping table from "enum tomoyo_path2_acl_index" to "enum tomoyo_mac_index".
  38  */
  39 const u8 tomoyo_pp2mac[TOMOYO_MAX_PATH2_OPERATION] = {
  40         [TOMOYO_TYPE_LINK]       = TOMOYO_MAC_FILE_LINK,
  41         [TOMOYO_TYPE_RENAME]     = TOMOYO_MAC_FILE_RENAME,
  42         [TOMOYO_TYPE_PIVOT_ROOT] = TOMOYO_MAC_FILE_PIVOT_ROOT,
  43 };
  44
  45 /*
  46  * Mapping table from "enum tomoyo_path_number_acl_index" to
  47  * "enum tomoyo_mac_index".
  48  */
  49 const u8 tomoyo_pn2mac[TOMOYO_MAX_PATH_NUMBER_OPERATION] = {
  50         [TOMOYO_TYPE_CREATE] = TOMOYO_MAC_FILE_CREATE,
  51         [TOMOYO_TYPE_MKDIR]  = TOMOYO_MAC_FILE_MKDIR,
  52         [TOMOYO_TYPE_MKFIFO] = TOMOYO_MAC_FILE_MKFIFO,
  53         [TOMOYO_TYPE_MKSOCK] = TOMOYO_MAC_FILE_MKSOCK,
  54         [TOMOYO_TYPE_IOCTL]  = TOMOYO_MAC_FILE_IOCTL,
  55         [TOMOYO_TYPE_CHMOD]  = TOMOYO_MAC_FILE_CHMOD,
  56         [TOMOYO_TYPE_CHOWN]  = TOMOYO_MAC_FILE_CHOWN,
  57         [TOMOYO_TYPE_CHGRP]  = TOMOYO_MAC_FILE_CHGRP,
  58 };
  59
  60 /**
  61  * tomoyo_put_name_union - Drop reference on "struct tomoyo_name_union".
  62  *
  63  * @ptr: Pointer to "struct tomoyo_name_union".
  64  *
  65  * Returns nothing.
  66  */
  67 void tomoyo_put_name_union(struct tomoyo_name_union *ptr)
  68 {
  69         tomoyo_put_group(ptr->group);
  70         tomoyo_put_name(ptr->filename);
  71 }
  72
  73 /**
  74  * tomoyo_compare_name_union - Check whether a name matches "struct tomoyo_name_union" or not.
  75  *
  76  * @name: Pointer to "struct tomoyo_path_info".
  77  * @ptr:  Pointer to "struct tomoyo_name_union".
  78  *
  79  * Returns "struct tomoyo_path_info" if @name matches @ptr, NULL otherwise.
  80  */
  81 const struct tomoyo_path_info *
  82 tomoyo_compare_name_union(const struct tomoyo_path_info *name,
  83                           const struct tomoyo_name_union *ptr)
  84 {
  85         if (ptr->group)
  86                 return tomoyo_path_matches_group(name, ptr->group);
  87         if (tomoyo_path_matches_pattern(name, ptr->filename))
  88                 return ptr->filename;
  89         return NULL;
  90 }
  91
  92 /**
  93  * tomoyo_put_number_union - Drop reference on "struct tomoyo_number_union".
  94  *
  95  * @ptr: Pointer to "struct tomoyo_number_union".
  96  *
  97  * Returns nothing.
  98  */
  99 void tomoyo_put_number_union(struct tomoyo_number_union *ptr)
 100 {
 101         tomoyo_put_group(ptr->group);
 102 }
 103
 104 /**
 105  * tomoyo_compare_number_union - Check whether a value matches "struct tomoyo_number_union" or not.
 106  *
 107  * @value: Number to check.
 108  * @ptr:   Pointer to "struct tomoyo_number_union".
 109  *
 110  * Returns true if @value matches @ptr, false otherwise.
 111  */
 112 bool tomoyo_compare_number_union(const unsigned long value,
 113                                  const struct tomoyo_number_union *ptr)
 114 {
 115         if (ptr->group)
 116                 return tomoyo_number_matches_group(value, value, ptr->group);
 117         return value >= ptr->values[0] && value <= ptr->values[1];
 118 }
 119
 120 /**
 121  * tomoyo_add_slash - Add trailing '/' if needed.
 122  *
 123  * @buf: Pointer to "struct tomoyo_path_info".
 124  *
 125  * Returns nothing.
 126  *
 127  * @buf must be generated by tomoyo_encode() because this function does not
 128  * allocate memory for adding '/'.
 129  */
 130 static void tomoyo_add_slash(struct tomoyo_path_info *buf)
 131 {
 132         if (buf->is_dir)
 133                 return;
 134         /*
 135          * This is OK because tomoyo_encode() reserves space for appending "/".
 136          */
 137         strcat((char *) buf->name, "/");
 138         tomoyo_fill_path_info(buf);
 139 }
 140
 141 /**
 142  * tomoyo_get_realpath - Get realpath.
 143  *
 144  * @buf:  Pointer to "struct tomoyo_path_info".
 145  * @path: Pointer to "struct path".
 146  *
 147  * Returns true on success, false otherwise.
 148  */
 149 static bool tomoyo_get_realpath(struct tomoyo_path_info *buf, const struct path *path)
 150 {
 151         buf->name = tomoyo_realpath_from_path(path);
 152         if (buf->name) {
 153                 tomoyo_fill_path_info(buf);
 154                 return true;
 155         }
 156         return false;
 157 }
 158
 159 /**
 160  * tomoyo_audit_path_log - Audit path request log.
 161  *
 162  * @r: Pointer to "struct tomoyo_request_info".
 163  *
 164  * Returns 0 on success, negative value otherwise.
 165  */
 166 static int tomoyo_audit_path_log(struct tomoyo_request_info *r)
 167 {
 168         return tomoyo_supervisor(r, "file %s %s\n", tomoyo_path_keyword
 169                                  [r->param.path.operation],
 170                                  r->param.path.filename->name);
 171 }
 172
 173 /**
 174  * tomoyo_audit_path2_log - Audit path/path request log.
 175  *
 176  * @r: Pointer to "struct tomoyo_request_info".
 177  *
 178  * Returns 0 on success, negative value otherwise.
 179  */
 180 static int tomoyo_audit_path2_log(struct tomoyo_request_info *r)
 181 {
 182         return tomoyo_supervisor(r, "file %s %s %s\n", tomoyo_mac_keywords
 183                                  [tomoyo_pp2mac[r->param.path2.operation]],
 184                                  r->param.path2.filename1->name,
 185                                  r->param.path2.filename2->name);
 186 }
 187
 188 /**
 189  * tomoyo_audit_mkdev_log - Audit path/number/number/number request log.
 190  *
 191  * @r: Pointer to "struct tomoyo_request_info".
 192  *
 193  * Returns 0 on success, negative value otherwise.
 194  */
 195 static int tomoyo_audit_mkdev_log(struct tomoyo_request_info *r)
 196 {
 197         return tomoyo_supervisor(r, "file %s %s 0%o %u %u\n",
 198                                  tomoyo_mac_keywords
 199                                  [tomoyo_pnnn2mac[r->param.mkdev.operation]],
 200                                  r->param.mkdev.filename->name,
 201                                  r->param.mkdev.mode, r->param.mkdev.major,
 202                                  r->param.mkdev.minor);
 203 }
 204
 205 /**
 206  * tomoyo_audit_path_number_log - Audit path/number request log.
 207  *
 208  * @r: Pointer to "struct tomoyo_request_info".
 209  *
 210  * Returns 0 on success, negative value otherwise.
 211  */
 212 static int tomoyo_audit_path_number_log(struct tomoyo_request_info *r)
 213 {
 214         const u8 type = r->param.path_number.operation;
 215         u8 radix;
 216         char buffer[64];
 217
 218         switch (type) {
 219         case TOMOYO_TYPE_CREATE:
 220         case TOMOYO_TYPE_MKDIR:
 221         case TOMOYO_TYPE_MKFIFO:
 222         case TOMOYO_TYPE_MKSOCK:
 223         case TOMOYO_TYPE_CHMOD:
 224                 radix = TOMOYO_VALUE_TYPE_OCTAL;
 225                 break;
 226         case TOMOYO_TYPE_IOCTL:
 227                 radix = TOMOYO_VALUE_TYPE_HEXADECIMAL;
 228                 break;
 229         default:
 230                 radix = TOMOYO_VALUE_TYPE_DECIMAL;
 231                 break;
 232         }
 233         tomoyo_print_ulong(buffer, sizeof(buffer), r->param.path_number.number,
 234                            radix);
 235         return tomoyo_supervisor(r, "file %s %s %s\n", tomoyo_mac_keywords
 236                                  [tomoyo_pn2mac[type]],
 237                                  r->param.path_number.filename->name, buffer);
 238 }
 239
 240 /**
 241  * tomoyo_check_path_acl - Check permission for path operation.
 242  *
 243  * @r:   Pointer to "struct tomoyo_request_info".
 244  * @ptr: Pointer to "struct tomoyo_acl_info".
 245  *
 246  * Returns true if granted, false otherwise.
 247  *
 248  * To be able to use wildcard for domain transition, this function sets
 249  * matching entry on success. Since the caller holds tomoyo_read_lock(),
 250  * it is safe to set matching entry.
 251  */
 252 static bool tomoyo_check_path_acl(struct tomoyo_request_info *r,
 253                                   const struct tomoyo_acl_info *ptr)
 254 {
 255         const struct tomoyo_path_acl *acl = container_of(ptr, typeof(*acl),
 256                                                          head);
 257
 258         if (acl->perm & (1 << r->param.path.operation)) {
 259                 r->param.path.matched_path =
 260                         tomoyo_compare_name_union(r->param.path.filename,
 261                                                   &acl->name);
 262                 return r->param.path.matched_path != NULL;
 263         }
 264         return false;
 265 }
 266
 267 /**
 268  * tomoyo_check_path_number_acl - Check permission for path number operation.
 269  *
 270  * @r:   Pointer to "struct tomoyo_request_info".
 271  * @ptr: Pointer to "struct tomoyo_acl_info".
 272  *
 273  * Returns true if granted, false otherwise.
 274  */
 275 static bool tomoyo_check_path_number_acl(struct tomoyo_request_info *r,
 276                                          const struct tomoyo_acl_info *ptr)
 277 {
 278         const struct tomoyo_path_number_acl *acl =
 279                 container_of(ptr, typeof(*acl), head);
 280
 281         return (acl->perm & (1 << r->param.path_number.operation)) &&
 282                 tomoyo_compare_number_union(r->param.path_number.number,
 283                                             &acl->number) &&
 284                 tomoyo_compare_name_union(r->param.path_number.filename,
 285                                           &acl->name);
 286 }
 287
 288 /**
 289  * tomoyo_check_path2_acl - Check permission for path path operation.
 290  *
 291  * @r:   Pointer to "struct tomoyo_request_info".
 292  * @ptr: Pointer to "struct tomoyo_acl_info".
 293  *
 294  * Returns true if granted, false otherwise.
 295  */
 296 static bool tomoyo_check_path2_acl(struct tomoyo_request_info *r,
 297                                    const struct tomoyo_acl_info *ptr)
 298 {
 299         const struct tomoyo_path2_acl *acl =
 300                 container_of(ptr, typeof(*acl), head);
 301
 302         return (acl->perm & (1 << r->param.path2.operation)) &&
 303                 tomoyo_compare_name_union(r->param.path2.filename1, &acl->name1)
 304                 && tomoyo_compare_name_union(r->param.path2.filename2,
 305                                              &acl->name2);
 306 }
 307
 308 /**
 309  * tomoyo_check_mkdev_acl - Check permission for path number number number operation.
 310  *
 311  * @r:   Pointer to "struct tomoyo_request_info".
 312  * @ptr: Pointer to "struct tomoyo_acl_info".
 313  *
 314  * Returns true if granted, false otherwise.
 315  */
 316 static bool tomoyo_check_mkdev_acl(struct tomoyo_request_info *r,
 317                                    const struct tomoyo_acl_info *ptr)
 318 {
 319         const struct tomoyo_mkdev_acl *acl =
 320                 container_of(ptr, typeof(*acl), head);
 321
 322         return (acl->perm & (1 << r->param.mkdev.operation)) &&
 323                 tomoyo_compare_number_union(r->param.mkdev.mode,
 324                                             &acl->mode) &&
 325                 tomoyo_compare_number_union(r->param.mkdev.major,
 326                                             &acl->major) &&
 327                 tomoyo_compare_number_union(r->param.mkdev.minor,
 328                                             &acl->minor) &&
 329                 tomoyo_compare_name_union(r->param.mkdev.filename,
 330                                           &acl->name);
 331 }
 332
 333 /**
 334  * tomoyo_same_path_acl - Check for duplicated "struct tomoyo_path_acl" entry.
 335  *
 336  * @a: Pointer to "struct tomoyo_acl_info".
 337  * @b: Pointer to "struct tomoyo_acl_info".
 338  *
 339  * Returns true if @a == @b except permission bits, false otherwise.
 340  */
 341 static bool tomoyo_same_path_acl(const struct tomoyo_acl_info *a,
 342                                  const struct tomoyo_acl_info *b)
 343 {
 344         const struct tomoyo_path_acl *p1 = container_of(a, typeof(*p1), head);
 345         const struct tomoyo_path_acl *p2 = container_of(b, typeof(*p2), head);
 346
 347         return tomoyo_same_name_union(&p1->name, &p2->name);
 348 }
 349
 350 /**
 351  * tomoyo_merge_path_acl - Merge duplicated "struct tomoyo_path_acl" entry.
 352  *
 353  * @a:         Pointer to "struct tomoyo_acl_info".
 354  * @b:         Pointer to "struct tomoyo_acl_info".
 355  * @is_delete: True for @a &= ~@b, false for @a |= @b.
 356  *
 357  * Returns true if @a is empty, false otherwise.
 358  */
 359 static bool tomoyo_merge_path_acl(struct tomoyo_acl_info *a,
 360                                   struct tomoyo_acl_info *b,
 361                                   const bool is_delete)
 362 {
 363         u16 * const a_perm = &container_of(a, struct tomoyo_path_acl, head)
 364                 ->perm;
 365         u16 perm = READ_ONCE(*a_perm);
 366         const u16 b_perm = container_of(b, struct tomoyo_path_acl, head)->perm;
 367
 368         if (is_delete)
 369                 perm &= ~b_perm;
 370         else
 371                 perm |= b_perm;
 372         WRITE_ONCE(*a_perm, perm);
 373         return !perm;
 374 }
 375
 376 /**
 377  * tomoyo_update_path_acl - Update "struct tomoyo_path_acl" list.
 378  *
 379  * @perm:  Permission.
 380  * @param: Pointer to "struct tomoyo_acl_param".
 381  *
 382  * Returns 0 on success, negative value otherwise.
 383  *
 384  * Caller holds tomoyo_read_lock().
 385  */
 386 static int tomoyo_update_path_acl(const u16 perm,
 387                                   struct tomoyo_acl_param *param)
 388 {
 389         struct tomoyo_path_acl e = {
 390                 .head.type = TOMOYO_TYPE_PATH_ACL,
 391                 .perm = perm
 392         };
 393         int error;
 394
 395         if (!tomoyo_parse_name_union(param, &e.name))
 396                 error = -EINVAL;
 397         else
 398                 error = tomoyo_update_domain(&e.head, sizeof(e), param,
 399                                              tomoyo_same_path_acl,
 400                                              tomoyo_merge_path_acl);
 401         tomoyo_put_name_union(&e.name);
 402         return error;
 403 }
 404
 405 /**
 406  * tomoyo_same_mkdev_acl - Check for duplicated "struct tomoyo_mkdev_acl" entry.
 407  *
 408  * @a: Pointer to "struct tomoyo_acl_info".
 409  * @b: Pointer to "struct tomoyo_acl_info".
 410  *
 411  * Returns true if @a == @b except permission bits, false otherwise.
 412  */
 413 static bool tomoyo_same_mkdev_acl(const struct tomoyo_acl_info *a,
 414                                          const struct tomoyo_acl_info *b)
 415 {
 416         const struct tomoyo_mkdev_acl *p1 = container_of(a, typeof(*p1), head);
 417         const struct tomoyo_mkdev_acl *p2 = container_of(b, typeof(*p2), head);
 418
 419         return tomoyo_same_name_union(&p1->name, &p2->name) &&
 420                 tomoyo_same_number_union(&p1->mode, &p2->mode) &&
 421                 tomoyo_same_number_union(&p1->major, &p2->major) &&
 422                 tomoyo_same_number_union(&p1->minor, &p2->minor);
 423 }
 424
 425 /**
 426  * tomoyo_merge_mkdev_acl - Merge duplicated "struct tomoyo_mkdev_acl" entry.
 427  *
 428  * @a:         Pointer to "struct tomoyo_acl_info".
 429  * @b:         Pointer to "struct tomoyo_acl_info".
 430  * @is_delete: True for @a &= ~@b, false for @a |= @b.
 431  *
 432  * Returns true if @a is empty, false otherwise.
 433  */
 434 static bool tomoyo_merge_mkdev_acl(struct tomoyo_acl_info *a,
 435                                    struct tomoyo_acl_info *b,
 436                                    const bool is_delete)
 437 {
 438         u8 *const a_perm = &container_of(a, struct tomoyo_mkdev_acl,
 439                                          head)->perm;
 440         u8 perm = READ_ONCE(*a_perm);
 441         const u8 b_perm = container_of(b, struct tomoyo_mkdev_acl, head)
 442                 ->perm;
 443
 444         if (is_delete)
 445                 perm &= ~b_perm;
 446         else
 447                 perm |= b_perm;
 448         WRITE_ONCE(*a_perm, perm);
 449         return !perm;
 450 }
 451
 452 /**
 453  * tomoyo_update_mkdev_acl - Update "struct tomoyo_mkdev_acl" list.
 454  *
 455  * @perm:  Permission.
 456  * @param: Pointer to "struct tomoyo_acl_param".
 457  *
 458  * Returns 0 on success, negative value otherwise.
 459  *
 460  * Caller holds tomoyo_read_lock().
 461  */
 462 static int tomoyo_update_mkdev_acl(const u8 perm,
 463                                    struct tomoyo_acl_param *param)
 464 {
 465         struct tomoyo_mkdev_acl e = {
 466                 .head.type = TOMOYO_TYPE_MKDEV_ACL,
 467                 .perm = perm
 468         };
 469         int error;
 470
 471         if (!tomoyo_parse_name_union(param, &e.name) ||
 472             !tomoyo_parse_number_union(param, &e.mode) ||
 473             !tomoyo_parse_number_union(param, &e.major) ||
 474             !tomoyo_parse_number_union(param, &e.minor))
 475                 error = -EINVAL;
 476         else
 477                 error = tomoyo_update_domain(&e.head, sizeof(e), param,
 478                                              tomoyo_same_mkdev_acl,
 479                                              tomoyo_merge_mkdev_acl);
 480         tomoyo_put_name_union(&e.name);
 481         tomoyo_put_number_union(&e.mode);
 482         tomoyo_put_number_union(&e.major);
 483         tomoyo_put_number_union(&e.minor);
 484         return error;
 485 }
 486
 487 /**
 488  * tomoyo_same_path2_acl - Check for duplicated "struct tomoyo_path2_acl" entry.
 489  *
 490  * @a: Pointer to "struct tomoyo_acl_info".
 491  * @b: Pointer to "struct tomoyo_acl_info".
 492  *
 493  * Returns true if @a == @b except permission bits, false otherwise.
 494  */
 495 static bool tomoyo_same_path2_acl(const struct tomoyo_acl_info *a,
 496                                   const struct tomoyo_acl_info *b)
 497 {
 498         const struct tomoyo_path2_acl *p1 = container_of(a, typeof(*p1), head);
 499         const struct tomoyo_path2_acl *p2 = container_of(b, typeof(*p2), head);
 500
 501         return tomoyo_same_name_union(&p1->name1, &p2->name1) &&
 502                 tomoyo_same_name_union(&p1->name2, &p2->name2);
 503 }
 504
 505 /**
 506  * tomoyo_merge_path2_acl - Merge duplicated "struct tomoyo_path2_acl" entry.
 507  *
 508  * @a:         Pointer to "struct tomoyo_acl_info".
 509  * @b:         Pointer to "struct tomoyo_acl_info".
 510  * @is_delete: True for @a &= ~@b, false for @a |= @b.
 511  *
 512  * Returns true if @a is empty, false otherwise.
 513  */
 514 static bool tomoyo_merge_path2_acl(struct tomoyo_acl_info *a,
 515                                    struct tomoyo_acl_info *b,
 516                                    const bool is_delete)
 517 {
 518         u8 * const a_perm = &container_of(a, struct tomoyo_path2_acl, head)
 519                 ->perm;
 520         u8 perm = READ_ONCE(*a_perm);
 521         const u8 b_perm = container_of(b, struct tomoyo_path2_acl, head)->perm;
 522
 523         if (is_delete)
 524                 perm &= ~b_perm;
 525         else
 526                 perm |= b_perm;
 527         WRITE_ONCE(*a_perm, perm);
 528         return !perm;
 529 }
 530
 531 /**
 532  * tomoyo_update_path2_acl - Update "struct tomoyo_path2_acl" list.
 533  *
 534  * @perm:  Permission.
 535  * @param: Pointer to "struct tomoyo_acl_param".
 536  *
 537  * Returns 0 on success, negative value otherwise.
 538  *
 539  * Caller holds tomoyo_read_lock().
 540  */
 541 static int tomoyo_update_path2_acl(const u8 perm,
 542                                    struct tomoyo_acl_param *param)
 543 {
 544         struct tomoyo_path2_acl e = {
 545                 .head.type = TOMOYO_TYPE_PATH2_ACL,
 546                 .perm = perm
 547         };
 548         int error;
 549
 550         if (!tomoyo_parse_name_union(param, &e.name1) ||
 551             !tomoyo_parse_name_union(param, &e.name2))
 552                 error = -EINVAL;
 553         else
 554                 error = tomoyo_update_domain(&e.head, sizeof(e), param,
 555                                              tomoyo_same_path2_acl,
 556                                              tomoyo_merge_path2_acl);
 557         tomoyo_put_name_union(&e.name1);
 558         tomoyo_put_name_union(&e.name2);
 559         return error;
 560 }
 561
 562 /**
 563  * tomoyo_path_permission - Check permission for single path operation.
 564  *
 565  * @r:         Pointer to "struct tomoyo_request_info".
 566  * @operation: Type of operation.
 567  * @filename:  Filename to check.
 568  *
 569  * Returns 0 on success, negative value otherwise.
 570  *
 571  * Caller holds tomoyo_read_lock().
 572  */
 573 static int tomoyo_path_permission(struct tomoyo_request_info *r, u8 operation,
 574                                   const struct tomoyo_path_info *filename)
 575 {
 576         int error;
 577
 578         r->type = tomoyo_p2mac[operation];
 579         r->mode = tomoyo_get_mode(r->domain->ns, r->profile, r->type);
 580         if (r->mode == TOMOYO_CONFIG_DISABLED)
 581                 return 0;
 582         r->param_type = TOMOYO_TYPE_PATH_ACL;
 583         r->param.path.filename = filename;
 584         r->param.path.operation = operation;
 585         do {
 586                 tomoyo_check_acl(r, tomoyo_check_path_acl);
 587                 error = tomoyo_audit_path_log(r);
 588         } while (error == TOMOYO_RETRY_REQUEST);
 589         return error;
 590 }
 591
 592 /**
 593  * tomoyo_execute_permission - Check permission for execute operation.
 594  *
 595  * @r:         Pointer to "struct tomoyo_request_info".
 596  * @filename:  Filename to check.
 597  *
 598  * Returns 0 on success, negative value otherwise.
 599  *
 600  * Caller holds tomoyo_read_lock().
 601  */
 602 int tomoyo_execute_permission(struct tomoyo_request_info *r,
 603                               const struct tomoyo_path_info *filename)
 604 {
 605         /*
 606          * Unlike other permission checks, this check is done regardless of
 607          * profile mode settings in order to check for domain transition
 608          * preference.
 609          */
 610         r->type = TOMOYO_MAC_FILE_EXECUTE;
 611         r->mode = tomoyo_get_mode(r->domain->ns, r->profile, r->type);
 612         r->param_type = TOMOYO_TYPE_PATH_ACL;
 613         r->param.path.filename = filename;
 614         r->param.path.operation = TOMOYO_TYPE_EXECUTE;
 615         tomoyo_check_acl(r, tomoyo_check_path_acl);
 616         r->ee->transition = r->matched_acl && r->matched_acl->cond ?
 617                 r->matched_acl->cond->transit : NULL;
 618         if (r->mode != TOMOYO_CONFIG_DISABLED)
 619                 return tomoyo_audit_path_log(r);
 620         return 0;
 621 }
 622
 623 /**
 624  * tomoyo_same_path_number_acl - Check for duplicated "struct tomoyo_path_number_acl" entry.
 625  *
 626  * @a: Pointer to "struct tomoyo_acl_info".
 627  * @b: Pointer to "struct tomoyo_acl_info".
 628  *
 629  * Returns true if @a == @b except permission bits, false otherwise.
 630  */
 631 static bool tomoyo_same_path_number_acl(const struct tomoyo_acl_info *a,
 632                                         const struct tomoyo_acl_info *b)
 633 {
 634         const struct tomoyo_path_number_acl *p1 = container_of(a, typeof(*p1),
 635                                                                head);
 636         const struct tomoyo_path_number_acl *p2 = container_of(b, typeof(*p2),
 637                                                                head);
 638
 639         return tomoyo_same_name_union(&p1->name, &p2->name) &&
 640                 tomoyo_same_number_union(&p1->number, &p2->number);
 641 }
 642
 643 /**
 644  * tomoyo_merge_path_number_acl - Merge duplicated "struct tomoyo_path_number_acl" entry.
 645  *
 646  * @a:         Pointer to "struct tomoyo_acl_info".
 647  * @b:         Pointer to "struct tomoyo_acl_info".
 648  * @is_delete: True for @a &= ~@b, false for @a |= @b.
 649  *
 650  * Returns true if @a is empty, false otherwise.
 651  */
 652 static bool tomoyo_merge_path_number_acl(struct tomoyo_acl_info *a,
 653                                          struct tomoyo_acl_info *b,
 654                                          const bool is_delete)
 655 {
 656         u8 * const a_perm = &container_of(a, struct tomoyo_path_number_acl,
 657                                           head)->perm;
 658         u8 perm = READ_ONCE(*a_perm);
 659         const u8 b_perm = container_of(b, struct tomoyo_path_number_acl, head)
 660                 ->perm;
 661
 662         if (is_delete)
 663                 perm &= ~b_perm;
 664         else
 665                 perm |= b_perm;
 666         WRITE_ONCE(*a_perm, perm);
 667         return !perm;
 668 }
 669
 670 /**
 671  * tomoyo_update_path_number_acl - Update ioctl/chmod/chown/chgrp ACL.
 672  *
 673  * @perm:  Permission.
 674  * @param: Pointer to "struct tomoyo_acl_param".
 675  *
 676  * Returns 0 on success, negative value otherwise.
 677  */
 678 static int tomoyo_update_path_number_acl(const u8 perm,
 679                                          struct tomoyo_acl_param *param)
 680 {
 681         struct tomoyo_path_number_acl e = {
 682                 .head.type = TOMOYO_TYPE_PATH_NUMBER_ACL,
 683                 .perm = perm
 684         };
 685         int error;
 686
 687         if (!tomoyo_parse_name_union(param, &e.name) ||
 688             !tomoyo_parse_number_union(param, &e.number))
 689                 error = -EINVAL;
 690         else
 691                 error = tomoyo_update_domain(&e.head, sizeof(e), param,
 692                                              tomoyo_same_path_number_acl,
 693                                              tomoyo_merge_path_number_acl);
 694         tomoyo_put_name_union(&e.name);
 695         tomoyo_put_number_union(&e.number);
 696         return error;
 697 }
 698
 699 /**
 700  * tomoyo_path_number_perm - Check permission for "create", "mkdir", "mkfifo", "mksock", "ioctl", "chmod", "chown", "chgrp".
 701  *
 702  * @type:   Type of operation.
 703  * @path:   Pointer to "struct path".
 704  * @number: Number.
 705  *
 706  * Returns 0 on success, negative value otherwise.
 707  */
 708 int tomoyo_path_number_perm(const u8 type, const struct path *path,
 709                             unsigned long number)
 710 {
 711         struct tomoyo_request_info r;
 712         struct tomoyo_obj_info obj = {
 713                 .path1 = { .mnt = path->mnt, .dentry = path->dentry },
 714         };
 715         int error = -ENOMEM;
 716         struct tomoyo_path_info buf;
 717         int idx;
 718
 719         if (tomoyo_init_request_info(&r, NULL, tomoyo_pn2mac[type])
 720             == TOMOYO_CONFIG_DISABLED)
 721                 return 0;
 722         idx = tomoyo_read_lock();
 723         if (!tomoyo_get_realpath(&buf, path))
 724                 goto out;
 725         r.obj = &obj;
 726         if (type == TOMOYO_TYPE_MKDIR)
 727                 tomoyo_add_slash(&buf);
 728         r.param_type = TOMOYO_TYPE_PATH_NUMBER_ACL;
 729         r.param.path_number.operation = type;
 730         r.param.path_number.filename = &buf;
 731         r.param.path_number.number = number;
 732         do {
 733                 tomoyo_check_acl(&r, tomoyo_check_path_number_acl);
 734                 error = tomoyo_audit_path_number_log(&r);
 735         } while (error == TOMOYO_RETRY_REQUEST);
 736         kfree(buf.name);
 737  out:
 738         tomoyo_read_unlock(idx);
 739         if (r.mode != TOMOYO_CONFIG_ENFORCING)
 740                 error = 0;
 741         return error;
 742 }
 743
 744 /**
 745  * tomoyo_check_open_permission - Check permission for "read" and "write".
 746  *
 747  * @domain: Pointer to "struct tomoyo_domain_info".
 748  * @path:   Pointer to "struct path".
 749  * @flag:   Flags for open().
 750  *
 751  * Returns 0 on success, negative value otherwise.
 752  */
 753 int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
 754                                  const struct path *path, const int flag)
 755 {
 756         const u8 acc_mode = ACC_MODE(flag);
 757         int error = 0;
 758         struct tomoyo_path_info buf;
 759         struct tomoyo_request_info r;
 760         struct tomoyo_obj_info obj = {
 761                 .path1 = { .mnt = path->mnt, .dentry = path->dentry },
 762         };
 763         int idx;
 764
 765         buf.name = NULL;
 766         r.mode = TOMOYO_CONFIG_DISABLED;
 767         idx = tomoyo_read_lock();
 768         if (acc_mode &&
 769             tomoyo_init_request_info(&r, domain, TOMOYO_MAC_FILE_OPEN)
 770             != TOMOYO_CONFIG_DISABLED) {
 771                 if (!tomoyo_get_realpath(&buf, path)) {
 772                         error = -ENOMEM;
 773                         goto out;
 774                 }
 775                 r.obj = &obj;
 776                 if (acc_mode & MAY_READ)
 777                         error = tomoyo_path_permission(&r, TOMOYO_TYPE_READ,
 778                                                        &buf);
 779                 if (!error && (acc_mode & MAY_WRITE))
 780                         error = tomoyo_path_permission(&r, (flag & O_APPEND) ?
 781                                                        TOMOYO_TYPE_APPEND :
 782                                                        TOMOYO_TYPE_WRITE,
 783                                                        &buf);
 784         }
 785  out:
 786         kfree(buf.name);
 787         tomoyo_read_unlock(idx);
 788         if (r.mode != TOMOYO_CONFIG_ENFORCING)
 789                 error = 0;
 790         return error;
 791 }
 792
 793 /**
 794  * tomoyo_path_perm - Check permission for "unlink", "rmdir", "truncate", "symlink", "append", "chroot" and "unmount".
 795  *
 796  * @operation: Type of operation.
 797  * @path:      Pointer to "struct path".
 798  * @target:    Symlink's target if @operation is TOMOYO_TYPE_SYMLINK,
 799  *             NULL otherwise.
 800  *
 801  * Returns 0 on success, negative value otherwise.
 802  */
 803 int tomoyo_path_perm(const u8 operation, const struct path *path, const char *target)
 804 {
 805         struct tomoyo_request_info r;
 806         struct tomoyo_obj_info obj = {
 807                 .path1 = { .mnt = path->mnt, .dentry = path->dentry },
 808         };
 809         int error;
 810         struct tomoyo_path_info buf;
 811         bool is_enforce;
 812         struct tomoyo_path_info symlink_target;
 813         int idx;
 814
 815         if (tomoyo_init_request_info(&r, NULL, tomoyo_p2mac[operation])
 816             == TOMOYO_CONFIG_DISABLED)
 817                 return 0;
 818         is_enforce = (r.mode == TOMOYO_CONFIG_ENFORCING);
 819         error = -ENOMEM;
 820         buf.name = NULL;
 821         idx = tomoyo_read_lock();
 822         if (!tomoyo_get_realpath(&buf, path))
 823                 goto out;
 824         r.obj = &obj;
 825         switch (operation) {
 826         case TOMOYO_TYPE_RMDIR:
 827         case TOMOYO_TYPE_CHROOT:
 828                 tomoyo_add_slash(&buf);
 829                 break;
 830         case TOMOYO_TYPE_SYMLINK:
 831                 symlink_target.name = tomoyo_encode(target);
 832                 if (!symlink_target.name)
 833                         goto out;
 834                 tomoyo_fill_path_info(&symlink_target);
 835                 obj.symlink_target = &symlink_target;
 836                 break;
 837         }
 838         error = tomoyo_path_permission(&r, operation, &buf);
 839         if (operation == TOMOYO_TYPE_SYMLINK)
 840                 kfree(symlink_target.name);
 841  out:
 842         kfree(buf.name);
 843         tomoyo_read_unlock(idx);
 844         if (!is_enforce)
 845                 error = 0;
 846         return error;
 847 }
 848
 849 /**
 850  * tomoyo_mkdev_perm - Check permission for "mkblock" and "mkchar".
 851  *
 852  * @operation: Type of operation. (TOMOYO_TYPE_MKCHAR or TOMOYO_TYPE_MKBLOCK)
 853  * @path:      Pointer to "struct path".
 854  * @mode:      Create mode.
 855  * @dev:       Device number.
 856  *
 857  * Returns 0 on success, negative value otherwise.
 858  */
 859 int tomoyo_mkdev_perm(const u8 operation, const struct path *path,
 860                       const unsigned int mode, unsigned int dev)
 861 {
 862         struct tomoyo_request_info r;
 863         struct tomoyo_obj_info obj = {
 864                 .path1 = { .mnt = path->mnt, .dentry = path->dentry },
 865         };
 866         int error = -ENOMEM;
 867         struct tomoyo_path_info buf;
 868         int idx;
 869
 870         if (tomoyo_init_request_info(&r, NULL, tomoyo_pnnn2mac[operation])
 871             == TOMOYO_CONFIG_DISABLED)
 872                 return 0;
 873         idx = tomoyo_read_lock();
 874         error = -ENOMEM;
 875         if (tomoyo_get_realpath(&buf, path)) {
 876                 r.obj = &obj;
 877                 dev = new_decode_dev(dev);
 878                 r.param_type = TOMOYO_TYPE_MKDEV_ACL;
 879                 r.param.mkdev.filename = &buf;
 880                 r.param.mkdev.operation = operation;
 881                 r.param.mkdev.mode = mode;
 882                 r.param.mkdev.major = MAJOR(dev);
 883                 r.param.mkdev.minor = MINOR(dev);
 884                 tomoyo_check_acl(&r, tomoyo_check_mkdev_acl);
 885                 error = tomoyo_audit_mkdev_log(&r);
 886                 kfree(buf.name);
 887         }
 888         tomoyo_read_unlock(idx);
 889         if (r.mode != TOMOYO_CONFIG_ENFORCING)
 890                 error = 0;
 891         return error;
 892 }
 893
 894 /**
 895  * tomoyo_path2_perm - Check permission for "rename", "link" and "pivot_root".
 896  *
 897  * @operation: Type of operation.
 898  * @path1:      Pointer to "struct path".
 899  * @path2:      Pointer to "struct path".
 900  *
 901  * Returns 0 on success, negative value otherwise.
 902  */
 903 int tomoyo_path2_perm(const u8 operation, const struct path *path1,
 904                       const struct path *path2)
 905 {
 906         int error = -ENOMEM;
 907         struct tomoyo_path_info buf1;
 908         struct tomoyo_path_info buf2;
 909         struct tomoyo_request_info r;
 910         struct tomoyo_obj_info obj = {
 911                 .path1 = { .mnt = path1->mnt, .dentry = path1->dentry },
 912                 .path2 = { .mnt = path2->mnt, .dentry = path2->dentry }
 913         };
 914         int idx;
 915
 916         if (tomoyo_init_request_info(&r, NULL, tomoyo_pp2mac[operation])
 917             == TOMOYO_CONFIG_DISABLED)
 918                 return 0;
 919         buf1.name = NULL;
 920         buf2.name = NULL;
 921         idx = tomoyo_read_lock();
 922         if (!tomoyo_get_realpath(&buf1, path1) ||
 923             !tomoyo_get_realpath(&buf2, path2))
 924                 goto out;
 925         switch (operation) {
 926         case TOMOYO_TYPE_RENAME:
 927         case TOMOYO_TYPE_LINK:
 928                 if (!d_is_dir(path1->dentry))
 929                         break;
 930                 fallthrough;
 931         case TOMOYO_TYPE_PIVOT_ROOT:
 932                 tomoyo_add_slash(&buf1);
 933                 tomoyo_add_slash(&buf2);
 934                 break;
 935         }
 936         r.obj = &obj;
 937         r.param_type = TOMOYO_TYPE_PATH2_ACL;
 938         r.param.path2.operation = operation;
 939         r.param.path2.filename1 = &buf1;
 940         r.param.path2.filename2 = &buf2;
 941         do {
 942                 tomoyo_check_acl(&r, tomoyo_check_path2_acl);
 943                 error = tomoyo_audit_path2_log(&r);
 944         } while (error == TOMOYO_RETRY_REQUEST);
 945  out:
 946         kfree(buf1.name);
 947         kfree(buf2.name);
 948         tomoyo_read_unlock(idx);
 949         if (r.mode != TOMOYO_CONFIG_ENFORCING)
 950                 error = 0;
 951         return error;
 952 }
 953
 954 /**
 955  * tomoyo_same_mount_acl - Check for duplicated "struct tomoyo_mount_acl" entry.
 956  *
 957  * @a: Pointer to "struct tomoyo_acl_info".
 958  * @b: Pointer to "struct tomoyo_acl_info".
 959  *
 960  * Returns true if @a == @b, false otherwise.
 961  */
 962 static bool tomoyo_same_mount_acl(const struct tomoyo_acl_info *a,
 963                                   const struct tomoyo_acl_info *b)
 964 {
 965         const struct tomoyo_mount_acl *p1 = container_of(a, typeof(*p1), head);
 966         const struct tomoyo_mount_acl *p2 = container_of(b, typeof(*p2), head);
 967
 968         return tomoyo_same_name_union(&p1->dev_name, &p2->dev_name) &&
 969                 tomoyo_same_name_union(&p1->dir_name, &p2->dir_name) &&
 970                 tomoyo_same_name_union(&p1->fs_type, &p2->fs_type) &&
 971                 tomoyo_same_number_union(&p1->flags, &p2->flags);
 972 }
 973
 974 /**
 975  * tomoyo_update_mount_acl - Write "struct tomoyo_mount_acl" list.
 976  *
 977  * @param: Pointer to "struct tomoyo_acl_param".
 978  *
 979  * Returns 0 on success, negative value otherwise.
 980  *
 981  * Caller holds tomoyo_read_lock().
 982  */
 983 static int tomoyo_update_mount_acl(struct tomoyo_acl_param *param)
 984 {
 985         struct tomoyo_mount_acl e = { .head.type = TOMOYO_TYPE_MOUNT_ACL };
 986         int error;
 987
 988         if (!tomoyo_parse_name_union(param, &e.dev_name) ||
 989             !tomoyo_parse_name_union(param, &e.dir_name) ||
 990             !tomoyo_parse_name_union(param, &e.fs_type) ||
 991             !tomoyo_parse_number_union(param, &e.flags))
 992                 error = -EINVAL;
 993         else
 994                 error = tomoyo_update_domain(&e.head, sizeof(e), param,
 995                                              tomoyo_same_mount_acl, NULL);
 996         tomoyo_put_name_union(&e.dev_name);
 997         tomoyo_put_name_union(&e.dir_name);
 998         tomoyo_put_name_union(&e.fs_type);
 999         tomoyo_put_number_union(&e.flags);
1000         return error;
1001 }
1002
1003 /**
1004  * tomoyo_write_file - Update file related list.
1005  *
1006  * @param: Pointer to "struct tomoyo_acl_param".
1007  *
1008  * Returns 0 on success, negative value otherwise.
1009  *
1010  * Caller holds tomoyo_read_lock().
1011  */
1012 int tomoyo_write_file(struct tomoyo_acl_param *param)
1013 {
1014         u16 perm = 0;
1015         u8 type;
1016         const char *operation = tomoyo_read_token(param);
1017
1018         for (type = 0; type < TOMOYO_MAX_PATH_OPERATION; type++)
1019                 if (tomoyo_permstr(operation, tomoyo_path_keyword[type]))
1020                         perm |= 1 << type;
1021         if (perm)
1022                 return tomoyo_update_path_acl(perm, param);
1023         for (type = 0; type < TOMOYO_MAX_PATH2_OPERATION; type++)
1024                 if (tomoyo_permstr(operation,
1025                                    tomoyo_mac_keywords[tomoyo_pp2mac[type]]))
1026                         perm |= 1 << type;
1027         if (perm)
1028                 return tomoyo_update_path2_acl(perm, param);
1029         for (type = 0; type < TOMOYO_MAX_PATH_NUMBER_OPERATION; type++)
1030                 if (tomoyo_permstr(operation,
1031                                    tomoyo_mac_keywords[tomoyo_pn2mac[type]]))
1032                         perm |= 1 << type;
1033         if (perm)
1034                 return tomoyo_update_path_number_acl(perm, param);
1035         for (type = 0; type < TOMOYO_MAX_MKDEV_OPERATION; type++)
1036                 if (tomoyo_permstr(operation,
1037                                    tomoyo_mac_keywords[tomoyo_pnnn2mac[type]]))
1038                         perm |= 1 << type;
1039         if (perm)
1040                 return tomoyo_update_mkdev_acl(perm, param);
1041         if (tomoyo_permstr(operation,
1042                            tomoyo_mac_keywords[TOMOYO_MAC_FILE_MOUNT]))
1043                 return tomoyo_update_mount_acl(param);
1044         return -EINVAL;
1045 }