1 // SPDX-License-Identifier: LGPL-2.1+ 2 /* 3 * Copyright (C) International Business Machines Corp., 2007,2008 4 * Author(s): Steve French (sfrench@us.ibm.com) 5 * Copyright (C) 2020 Samsung Electronics Co., Ltd. 6 * Author(s): Namjae Jeon <linkinjeon@kernel.org> 7 */ 8 9 #include <linux/fs.h> 10 #include <linux/slab.h> 11 #include <linux/string.h> 12 #include <linux/mnt_idmapping.h> 13 14 #include "smbacl.h" 15 #include "smb_common.h" 16 #include "server.h" 17 #include "misc.h" 18 #include "mgmt/share_config.h" 19 20 static const struct smb_sid domain = {1, 4, {0, 0, 0, 0, 0, 5}, 21 {cpu_to_le32(21), cpu_to_le32(1), cpu_to_le32(2), cpu_to_le32(3), 22 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; 23 24 /* security id for everyone/world system group */ 25 static const struct smb_sid creator_owner = { 26 1, 1, {0, 0, 0, 0, 0, 3}, {0} }; 27 /* security id for everyone/world system group */ 28 static const struct smb_sid creator_group = { 29 1, 1, {0, 0, 0, 0, 0, 3}, {cpu_to_le32(1)} }; 30 31 /* security id for everyone/world system group */ 32 static const struct smb_sid sid_everyone = { 33 1, 1, {0, 0, 0, 0, 0, 1}, {0} }; 34 /* security id for Authenticated Users system group */ 35 static const struct smb_sid sid_authusers = { 36 1, 1, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(11)} }; 37 38 /* S-1-22-1 Unmapped Unix users */ 39 static const struct smb_sid sid_unix_users = {1, 1, {0, 0, 0, 0, 0, 22}, 40 {cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; 41 42 /* S-1-22-2 Unmapped Unix groups */ 43 static const struct smb_sid sid_unix_groups = { 1, 1, {0, 0, 0, 0, 0, 22}, 44 {cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; 45 46 /* 47 * See http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx 48 */ 49 50 /* S-1-5-88 MS NFS and Apple style UID/GID/mode */ 51 52 /* S-1-5-88-1 Unix uid */ 53 static const struct smb_sid sid_unix_NFS_users = { 1, 2, {0, 0, 0, 0, 0, 5}, 54 {cpu_to_le32(88), 55 cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; 56 57 /* S-1-5-88-2 Unix gid */ 58 static const struct smb_sid sid_unix_NFS_groups = { 1, 2, {0, 0, 0, 0, 0, 5}, 59 {cpu_to_le32(88), 60 cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; 61 62 /* S-1-5-88-3 Unix mode */ 63 static const struct smb_sid sid_unix_NFS_mode = { 1, 2, {0, 0, 0, 0, 0, 5}, 64 {cpu_to_le32(88), 65 cpu_to_le32(3), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} }; 66 67 /* 68 * if the two SIDs (roughly equivalent to a UUID for a user or group) are 69 * the same returns zero, if they do not match returns non-zero. 70 */ 71 int compare_sids(const struct smb_sid *ctsid, const struct smb_sid *cwsid) 72 { 73 int i; 74 int num_subauth, num_sat, num_saw; 75 76 if (!ctsid || !cwsid) 77 return 1; 78 79 /* compare the revision */ 80 if (ctsid->revision != cwsid->revision) { 81 if (ctsid->revision > cwsid->revision) 82 return 1; 83 else 84 return -1; 85 } 86 87 /* compare all of the six auth values */ 88 for (i = 0; i < NUM_AUTHS; ++i) { 89 if (ctsid->authority[i] != cwsid->authority[i]) { 90 if (ctsid->authority[i] > cwsid->authority[i]) 91 return 1; 92 else 93 return -1; 94 } 95 } 96 97 /* compare all of the subauth values if any */ 98 num_sat = ctsid->num_subauth; 99 num_saw = cwsid->num_subauth; 100 num_subauth = min(num_sat, num_saw); 101 if (num_subauth) { 102 for (i = 0; i < num_subauth; ++i) { 103 if (ctsid->sub_auth[i] != cwsid->sub_auth[i]) { 104 if (le32_to_cpu(ctsid->sub_auth[i]) > 105 le32_to_cpu(cwsid->sub_auth[i])) 106 return 1; 107 else 108 return -1; 109 } 110 } 111 } 112 113 return 0; /* sids compare/match */ 114 } 115 116 static void smb_copy_sid(struct smb_sid *dst, const struct smb_sid *src) 117 { 118 int i; 119 120 dst->revision = src->revision; 121 dst->num_subauth = min_t(u8, src->num_subauth, SID_MAX_SUB_AUTHORITIES); 122 for (i = 0; i < NUM_AUTHS; ++i) 123 dst->authority[i] = src->authority[i]; 124 for (i = 0; i < dst->num_subauth; ++i) 125 dst->sub_auth[i] = src->sub_auth[i]; 126 } 127 128 /* 129 * change posix mode to reflect permissions 130 * pmode is the existing mode (we only want to overwrite part of this 131 * bits to set can be: S_IRWXU, S_IRWXG or S_IRWXO ie 00700 or 00070 or 00007 132 */ 133 static umode_t access_flags_to_mode(struct smb_fattr *fattr, __le32 ace_flags, 134 int type) 135 { 136 __u32 flags = le32_to_cpu(ace_flags); 137 umode_t mode = 0; 138 139 if (flags & GENERIC_ALL) { 140 mode = 0777; 141 ksmbd_debug(SMB, "all perms\n"); 142 return mode; 143 } 144 145 if ((flags & GENERIC_READ) || (flags & FILE_READ_RIGHTS)) 146 mode = 0444; 147 if ((flags & GENERIC_WRITE) || (flags & FILE_WRITE_RIGHTS)) { 148 mode |= 0222; 149 if (S_ISDIR(fattr->cf_mode)) 150 mode |= 0111; 151 } 152 if ((flags & GENERIC_EXECUTE) || (flags & FILE_EXEC_RIGHTS)) 153 mode |= 0111; 154 155 if (type == ACCESS_DENIED_ACE_TYPE || type == ACCESS_DENIED_OBJECT_ACE_TYPE) 156 mode = ~mode; 157 158 ksmbd_debug(SMB, "access flags 0x%x mode now %04o\n", flags, mode); 159 160 return mode; 161 } 162 163 /* 164 * Generate access flags to reflect permissions mode is the existing mode. 165 * This function is called for every ACE in the DACL whose SID matches 166 * with either owner or group or everyone. 167 */ 168 static void mode_to_access_flags(umode_t mode, umode_t bits_to_use, 169 __u32 *pace_flags) 170 { 171 /* reset access mask */ 172 *pace_flags = 0x0; 173 174 /* bits to use are either S_IRWXU or S_IRWXG or S_IRWXO */ 175 mode &= bits_to_use; 176 177 /* 178 * check for R/W/X UGO since we do not know whose flags 179 * is this but we have cleared all the bits sans RWX for 180 * either user or group or other as per bits_to_use 181 */ 182 if (mode & 0444) 183 *pace_flags |= SET_FILE_READ_RIGHTS; 184 if (mode & 0222) 185 *pace_flags |= FILE_WRITE_RIGHTS; 186 if (mode & 0111) 187 *pace_flags |= SET_FILE_EXEC_RIGHTS; 188 189 ksmbd_debug(SMB, "mode: %o, access flags now 0x%x\n", 190 mode, *pace_flags); 191 } 192 193 static __u16 fill_ace_for_sid(struct smb_ace *pntace, 194 const struct smb_sid *psid, int type, int flags, 195 umode_t mode, umode_t bits) 196 { 197 int i; 198 __u16 size = 0; 199 __u32 access_req = 0; 200 201 pntace->type = type; 202 pntace->flags = flags; 203 mode_to_access_flags(mode, bits, &access_req); 204 if (!access_req) 205 access_req = SET_MINIMUM_RIGHTS; 206 pntace->access_req = cpu_to_le32(access_req); 207 208 pntace->sid.revision = psid->revision; 209 pntace->sid.num_subauth = psid->num_subauth; 210 for (i = 0; i < NUM_AUTHS; i++) 211 pntace->sid.authority[i] = psid->authority[i]; 212 for (i = 0; i < psid->num_subauth; i++) 213 pntace->sid.sub_auth[i] = psid->sub_auth[i]; 214 215 size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth * 4); 216 pntace->size = cpu_to_le16(size); 217 218 return size; 219 } 220 221 void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid) 222 { 223 switch (sidtype) { 224 case SIDOWNER: 225 smb_copy_sid(ssid, &server_conf.domain_sid); 226 break; 227 case SIDUNIX_USER: 228 smb_copy_sid(ssid, &sid_unix_users); 229 break; 230 case SIDUNIX_GROUP: 231 smb_copy_sid(ssid, &sid_unix_groups); 232 break; 233 case SIDCREATOR_OWNER: 234 smb_copy_sid(ssid, &creator_owner); 235 return; 236 case SIDCREATOR_GROUP: 237 smb_copy_sid(ssid, &creator_group); 238 return; 239 case SIDNFS_USER: 240 smb_copy_sid(ssid, &sid_unix_NFS_users); 241 break; 242 case SIDNFS_GROUP: 243 smb_copy_sid(ssid, &sid_unix_NFS_groups); 244 break; 245 case SIDNFS_MODE: 246 smb_copy_sid(ssid, &sid_unix_NFS_mode); 247 break; 248 default: 249 return; 250 } 251 252 /* RID */ 253 ssid->sub_auth[ssid->num_subauth] = cpu_to_le32(cid); 254 ssid->num_subauth++; 255 } 256 257 static int sid_to_id(struct mnt_idmap *idmap, 258 struct smb_sid *psid, uint sidtype, 259 struct smb_fattr *fattr) 260 { 261 const struct smb_sid *sid_prefix; 262 int rc = -EINVAL; 263 264 /* 265 * If we have too many subauthorities, then something is really wrong. 266 * Just return an error. 267 */ 268 if (unlikely(psid->num_subauth > SID_MAX_SUB_AUTHORITIES)) { 269 pr_err("%s: %u subauthorities is too many!\n", 270 __func__, psid->num_subauth); 271 return -EIO; 272 } 273 274 if (psid->num_subauth == 0) { 275 pr_err("%s: zero subauthorities!\n", __func__); 276 return -EIO; 277 } 278 279 if (sidtype == SIDOWNER) { 280 kuid_t uid; 281 uid_t id; 282 283 /* Only the server domain RID has a local uid representation. */ 284 sid_prefix = &server_conf.domain_sid; 285 if (psid->num_subauth != sid_prefix->num_subauth + 1 || 286 compare_sids(psid, sid_prefix)) 287 return -EINVAL; 288 289 id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]); 290 uid = KUIDT_INIT(id); 291 uid = from_vfsuid(idmap, &init_user_ns, VFSUIDT_INIT(uid)); 292 if (uid_valid(uid)) { 293 fattr->cf_uid = uid; 294 rc = 0; 295 } 296 } else { 297 kgid_t gid; 298 gid_t id; 299 300 /* Local gids are represented by S-1-22-2-<gid>. */ 301 sid_prefix = &sid_unix_groups; 302 if (psid->num_subauth != sid_prefix->num_subauth + 1 || 303 compare_sids(psid, sid_prefix)) 304 return -EINVAL; 305 306 id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]); 307 gid = KGIDT_INIT(id); 308 gid = from_vfsgid(idmap, &init_user_ns, VFSGIDT_INIT(gid)); 309 if (gid_valid(gid)) { 310 fattr->cf_gid = gid; 311 rc = 0; 312 } 313 } 314 315 return rc; 316 } 317 318 void posix_state_to_acl(struct posix_acl_state *state, 319 struct posix_acl_entry *pace) 320 { 321 int i; 322 323 pace->e_tag = ACL_USER_OBJ; 324 pace->e_perm = state->owner.allow; 325 for (i = 0; i < state->users->n; i++) { 326 pace++; 327 pace->e_tag = ACL_USER; 328 pace->e_uid = state->users->aces[i].uid; 329 pace->e_perm = state->users->aces[i].perms.allow; 330 } 331 332 pace++; 333 pace->e_tag = ACL_GROUP_OBJ; 334 pace->e_perm = state->group.allow; 335 336 for (i = 0; i < state->groups->n; i++) { 337 pace++; 338 pace->e_tag = ACL_GROUP; 339 pace->e_gid = state->groups->aces[i].gid; 340 pace->e_perm = state->groups->aces[i].perms.allow; 341 } 342 343 if (state->users->n || state->groups->n) { 344 pace++; 345 pace->e_tag = ACL_MASK; 346 pace->e_perm = state->mask.allow; 347 } 348 349 pace++; 350 pace->e_tag = ACL_OTHER; 351 pace->e_perm = state->other.allow; 352 } 353 354 int init_acl_state(struct posix_acl_state *state, u16 cnt) 355 { 356 int alloc; 357 358 memset(state, 0, sizeof(struct posix_acl_state)); 359 /* 360 * In the worst case, each individual acl could be for a distinct 361 * named user or group, but we don't know which, so we allocate 362 * enough space for either: 363 */ 364 alloc = sizeof(struct posix_ace_state_array) 365 + cnt * sizeof(struct posix_user_ace_state); 366 state->users = kzalloc(alloc, KSMBD_DEFAULT_GFP); 367 if (!state->users) 368 return -ENOMEM; 369 state->groups = kzalloc(alloc, KSMBD_DEFAULT_GFP); 370 if (!state->groups) { 371 kfree(state->users); 372 return -ENOMEM; 373 } 374 return 0; 375 } 376 377 void free_acl_state(struct posix_acl_state *state) 378 { 379 kfree(state->users); 380 kfree(state->groups); 381 } 382 383 static void parse_dacl(struct mnt_idmap *idmap, 384 struct smb_acl *pdacl, char *end_of_acl, 385 struct smb_sid *pownersid, struct smb_sid *pgrpsid, 386 struct smb_fattr *fattr) 387 { 388 int i, ret; 389 u16 num_aces = 0; 390 u16 dacl_size; 391 unsigned int acl_size; 392 char *acl_base; 393 struct smb_ace **ppace; 394 struct posix_acl_entry *cf_pace, *cf_pdace; 395 struct posix_acl_state acl_state, default_acl_state; 396 umode_t mode = 0, acl_mode; 397 bool owner_found = false, group_found = false, others_found = false; 398 399 if (!pdacl) 400 return; 401 402 /* validate that we do not go past end of acl */ 403 if (end_of_acl < (char *)pdacl + sizeof(struct smb_acl) || 404 end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) { 405 pr_err("ACL too small to parse DACL\n"); 406 return; 407 } 408 409 ksmbd_debug(SMB, "DACL revision %d size %d num aces %d\n", 410 le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size), 411 le16_to_cpu(pdacl->num_aces)); 412 413 acl_base = (char *)pdacl; 414 acl_size = sizeof(struct smb_acl); 415 416 num_aces = le16_to_cpu(pdacl->num_aces); 417 if (num_aces <= 0) 418 return; 419 420 dacl_size = le16_to_cpu(pdacl->size); 421 if (dacl_size < sizeof(struct smb_acl)) 422 return; 423 424 if (num_aces > (dacl_size - sizeof(struct smb_acl)) / 425 (offsetof(struct smb_ace, sid) + 426 offsetof(struct smb_sid, sub_auth) + sizeof(__le16))) 427 return; 428 429 ret = init_acl_state(&acl_state, num_aces); 430 if (ret) 431 return; 432 ret = init_acl_state(&default_acl_state, num_aces); 433 if (ret) { 434 free_acl_state(&acl_state); 435 return; 436 } 437 438 ppace = kmalloc_objs(struct smb_ace *, num_aces, KSMBD_DEFAULT_GFP); 439 if (!ppace) { 440 free_acl_state(&default_acl_state); 441 free_acl_state(&acl_state); 442 return; 443 } 444 445 /* 446 * reset rwx permissions for user/group/other. 447 * Also, if num_aces is 0 i.e. DACL has no ACEs, 448 * user/group/other have no permissions 449 */ 450 for (i = 0; i < num_aces; ++i) { 451 if (end_of_acl - acl_base < acl_size) 452 break; 453 454 ppace[i] = (struct smb_ace *)(acl_base + acl_size); 455 acl_base = (char *)ppace[i]; 456 acl_size = offsetof(struct smb_ace, sid) + 457 offsetof(struct smb_sid, sub_auth); 458 459 if (end_of_acl - acl_base < acl_size || 460 ppace[i]->sid.num_subauth == 0 || 461 ppace[i]->sid.num_subauth > SID_MAX_SUB_AUTHORITIES || 462 (end_of_acl - acl_base < 463 acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth) || 464 (le16_to_cpu(ppace[i]->size) < 465 acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth)) 466 break; 467 468 acl_size = le16_to_cpu(ppace[i]->size); 469 ppace[i]->access_req = 470 smb_map_generic_desired_access(ppace[i]->access_req); 471 472 if (ppace[i]->sid.num_subauth >= 3 && 473 !(compare_sids(&ppace[i]->sid, &sid_unix_NFS_mode))) { 474 fattr->cf_mode = 475 le32_to_cpu(ppace[i]->sid.sub_auth[2]); 476 break; 477 } else if (!compare_sids(&ppace[i]->sid, pownersid)) { 478 acl_mode = access_flags_to_mode(fattr, 479 ppace[i]->access_req, 480 ppace[i]->type); 481 acl_mode &= 0700; 482 483 if (!owner_found) { 484 mode &= ~(0700); 485 mode |= acl_mode; 486 } 487 owner_found = true; 488 } else if (!compare_sids(&ppace[i]->sid, pgrpsid) || 489 ppace[i]->sid.sub_auth[ppace[i]->sid.num_subauth - 1] == 490 DOMAIN_USER_RID_LE) { 491 acl_mode = access_flags_to_mode(fattr, 492 ppace[i]->access_req, 493 ppace[i]->type); 494 acl_mode &= 0070; 495 if (!group_found) { 496 mode &= ~(0070); 497 mode |= acl_mode; 498 } 499 group_found = true; 500 } else if (!compare_sids(&ppace[i]->sid, &sid_everyone)) { 501 acl_mode = access_flags_to_mode(fattr, 502 ppace[i]->access_req, 503 ppace[i]->type); 504 acl_mode &= 0007; 505 if (!others_found) { 506 mode &= ~(0007); 507 mode |= acl_mode; 508 } 509 others_found = true; 510 } else if (!compare_sids(&ppace[i]->sid, &creator_owner)) { 511 continue; 512 } else if (!compare_sids(&ppace[i]->sid, &creator_group)) { 513 continue; 514 } else if (!compare_sids(&ppace[i]->sid, &sid_authusers)) { 515 continue; 516 } else { 517 struct smb_fattr temp_fattr; 518 519 acl_mode = access_flags_to_mode(fattr, ppace[i]->access_req, 520 ppace[i]->type); 521 temp_fattr.cf_uid = INVALID_UID; 522 ret = sid_to_id(idmap, &ppace[i]->sid, SIDOWNER, &temp_fattr); 523 if (ret || uid_eq(temp_fattr.cf_uid, INVALID_UID)) { 524 pr_err("%s: Error %d mapping Owner SID to uid\n", 525 __func__, ret); 526 continue; 527 } 528 529 acl_state.owner.allow = ((acl_mode & 0700) >> 6) | 0004; 530 acl_state.users->aces[acl_state.users->n].uid = 531 temp_fattr.cf_uid; 532 acl_state.users->aces[acl_state.users->n++].perms.allow = 533 ((acl_mode & 0700) >> 6) | 0004; 534 default_acl_state.owner.allow = ((acl_mode & 0700) >> 6) | 0004; 535 default_acl_state.users->aces[default_acl_state.users->n].uid = 536 temp_fattr.cf_uid; 537 default_acl_state.users->aces[default_acl_state.users->n++].perms.allow = 538 ((acl_mode & 0700) >> 6) | 0004; 539 } 540 } 541 kfree(ppace); 542 543 if (owner_found) { 544 /* The owner must be set to at least read-only. */ 545 acl_state.owner.allow = ((mode & 0700) >> 6) | 0004; 546 acl_state.users->aces[acl_state.users->n].uid = fattr->cf_uid; 547 acl_state.users->aces[acl_state.users->n++].perms.allow = 548 ((mode & 0700) >> 6) | 0004; 549 default_acl_state.owner.allow = ((mode & 0700) >> 6) | 0004; 550 default_acl_state.users->aces[default_acl_state.users->n].uid = 551 fattr->cf_uid; 552 default_acl_state.users->aces[default_acl_state.users->n++].perms.allow = 553 ((mode & 0700) >> 6) | 0004; 554 } 555 556 if (group_found) { 557 acl_state.group.allow = (mode & 0070) >> 3; 558 acl_state.groups->aces[acl_state.groups->n].gid = 559 fattr->cf_gid; 560 acl_state.groups->aces[acl_state.groups->n++].perms.allow = 561 (mode & 0070) >> 3; 562 default_acl_state.group.allow = (mode & 0070) >> 3; 563 default_acl_state.groups->aces[default_acl_state.groups->n].gid = 564 fattr->cf_gid; 565 default_acl_state.groups->aces[default_acl_state.groups->n++].perms.allow = 566 (mode & 0070) >> 3; 567 } 568 569 if (others_found) { 570 fattr->cf_mode &= ~(0007); 571 fattr->cf_mode |= mode & 0007; 572 573 acl_state.other.allow = mode & 0007; 574 default_acl_state.other.allow = mode & 0007; 575 } 576 577 if (acl_state.users->n || acl_state.groups->n) { 578 acl_state.mask.allow = 0x07; 579 580 if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) { 581 fattr->cf_acls = 582 posix_acl_alloc(acl_state.users->n + 583 acl_state.groups->n + 4, KSMBD_DEFAULT_GFP); 584 if (fattr->cf_acls) { 585 cf_pace = fattr->cf_acls->a_entries; 586 posix_state_to_acl(&acl_state, cf_pace); 587 } 588 } 589 } 590 591 if (default_acl_state.users->n || default_acl_state.groups->n) { 592 default_acl_state.mask.allow = 0x07; 593 594 if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) { 595 fattr->cf_dacls = 596 posix_acl_alloc(default_acl_state.users->n + 597 default_acl_state.groups->n + 4, KSMBD_DEFAULT_GFP); 598 if (fattr->cf_dacls) { 599 cf_pdace = fattr->cf_dacls->a_entries; 600 posix_state_to_acl(&default_acl_state, cf_pdace); 601 } 602 } 603 } 604 free_acl_state(&acl_state); 605 free_acl_state(&default_acl_state); 606 } 607 608 static void set_posix_acl_entries_dacl(struct mnt_idmap *idmap, 609 struct smb_ace *pndace, 610 struct smb_fattr *fattr, u16 *num_aces, 611 u16 *size, u32 nt_aces_num) 612 { 613 struct posix_acl_entry *pace; 614 struct smb_sid *sid; 615 struct smb_ace *ntace; 616 int i, j; 617 u16 ace_sz; 618 619 if (!fattr->cf_acls) 620 goto posix_default_acl; 621 622 pace = fattr->cf_acls->a_entries; 623 for (i = 0; i < fattr->cf_acls->a_count; i++, pace++) { 624 int flags = 0; 625 626 sid = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP); 627 if (!sid) 628 break; 629 630 if (pace->e_tag == ACL_USER) { 631 uid_t uid; 632 unsigned int sid_type = SIDOWNER; 633 634 uid = posix_acl_uid_translate(idmap, pace); 635 if (!uid) 636 sid_type = SIDUNIX_USER; 637 id_to_sid(uid, sid_type, sid); 638 } else if (pace->e_tag == ACL_GROUP) { 639 gid_t gid; 640 641 gid = posix_acl_gid_translate(idmap, pace); 642 id_to_sid(gid, SIDUNIX_GROUP, sid); 643 } else if (pace->e_tag == ACL_OTHER && !nt_aces_num) { 644 smb_copy_sid(sid, &sid_everyone); 645 } else { 646 kfree(sid); 647 continue; 648 } 649 ntace = pndace; 650 for (j = 0; j < nt_aces_num; j++) { 651 if (ntace->sid.sub_auth[ntace->sid.num_subauth - 1] == 652 sid->sub_auth[sid->num_subauth - 1]) 653 goto pass_same_sid; 654 ntace = (struct smb_ace *)((char *)ntace + 655 le16_to_cpu(ntace->size)); 656 } 657 658 if (S_ISDIR(fattr->cf_mode) && pace->e_tag == ACL_OTHER) 659 flags = 0x03; 660 661 ntace = (struct smb_ace *)((char *)pndace + *size); 662 ace_sz = fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, flags, 663 pace->e_perm, 0777); 664 if (check_add_overflow(*size, ace_sz, size)) { 665 kfree(sid); 666 break; 667 } 668 (*num_aces)++; 669 if (pace->e_tag == ACL_USER) 670 ntace->access_req |= 671 FILE_DELETE_LE | FILE_DELETE_CHILD_LE; 672 673 if (S_ISDIR(fattr->cf_mode) && 674 (pace->e_tag == ACL_USER || pace->e_tag == ACL_GROUP)) { 675 ntace = (struct smb_ace *)((char *)pndace + *size); 676 ace_sz = fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, 677 0x03, pace->e_perm, 0777); 678 if (check_add_overflow(*size, ace_sz, size)) { 679 kfree(sid); 680 break; 681 } 682 (*num_aces)++; 683 if (pace->e_tag == ACL_USER) 684 ntace->access_req |= 685 FILE_DELETE_LE | FILE_DELETE_CHILD_LE; 686 } 687 688 pass_same_sid: 689 kfree(sid); 690 } 691 692 if (nt_aces_num) 693 return; 694 695 posix_default_acl: 696 if (!fattr->cf_dacls) 697 return; 698 699 pace = fattr->cf_dacls->a_entries; 700 for (i = 0; i < fattr->cf_dacls->a_count; i++, pace++) { 701 sid = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP); 702 if (!sid) 703 break; 704 705 if (pace->e_tag == ACL_USER) { 706 uid_t uid; 707 708 uid = posix_acl_uid_translate(idmap, pace); 709 id_to_sid(uid, SIDCREATOR_OWNER, sid); 710 } else if (pace->e_tag == ACL_GROUP) { 711 gid_t gid; 712 713 gid = posix_acl_gid_translate(idmap, pace); 714 id_to_sid(gid, SIDCREATOR_GROUP, sid); 715 } else { 716 kfree(sid); 717 continue; 718 } 719 720 ntace = (struct smb_ace *)((char *)pndace + *size); 721 ace_sz = fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, 0x0b, 722 pace->e_perm, 0777); 723 if (check_add_overflow(*size, ace_sz, size)) { 724 kfree(sid); 725 break; 726 } 727 (*num_aces)++; 728 if (pace->e_tag == ACL_USER) 729 ntace->access_req |= 730 FILE_DELETE_LE | FILE_DELETE_CHILD_LE; 731 kfree(sid); 732 } 733 } 734 735 static void set_ntacl_dacl(struct mnt_idmap *idmap, 736 struct smb_acl *pndacl, 737 struct smb_acl *nt_dacl, 738 unsigned int aces_size, 739 const struct smb_sid *pownersid, 740 const struct smb_sid *pgrpsid, 741 struct smb_fattr *fattr) 742 { 743 struct smb_ace *ntace, *pndace; 744 u16 nt_num_aces = le16_to_cpu(nt_dacl->num_aces), num_aces = 0; 745 unsigned short size = 0; 746 int i; 747 748 pndace = (struct smb_ace *)((char *)pndacl + sizeof(struct smb_acl)); 749 if (nt_num_aces) { 750 ntace = (struct smb_ace *)((char *)nt_dacl + sizeof(struct smb_acl)); 751 for (i = 0; i < nt_num_aces; i++) { 752 unsigned short nt_ace_size; 753 754 if (offsetof(struct smb_ace, access_req) > aces_size) 755 break; 756 757 nt_ace_size = le16_to_cpu(ntace->size); 758 if (nt_ace_size > aces_size) 759 break; 760 761 if (ntace->sid.num_subauth == 0 || 762 ntace->sid.num_subauth > SID_MAX_SUB_AUTHORITIES) 763 goto next_ace; 764 765 memcpy((char *)pndace + size, ntace, nt_ace_size); 766 if (check_add_overflow(size, nt_ace_size, &size)) 767 break; 768 num_aces++; 769 770 next_ace: 771 aces_size -= nt_ace_size; 772 ntace = (struct smb_ace *)((char *)ntace + nt_ace_size); 773 } 774 } 775 776 set_posix_acl_entries_dacl(idmap, pndace, fattr, 777 &num_aces, &size, nt_num_aces); 778 pndacl->num_aces = cpu_to_le16(num_aces); 779 pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size); 780 } 781 782 static void set_mode_dacl(struct mnt_idmap *idmap, 783 struct smb_acl *pndacl, struct smb_fattr *fattr) 784 { 785 struct smb_ace *pace, *pndace; 786 u16 num_aces = 0; 787 u16 size = 0, ace_size = 0; 788 uid_t uid; 789 const struct smb_sid *sid; 790 791 pace = pndace = (struct smb_ace *)((char *)pndacl + sizeof(struct smb_acl)); 792 793 if (fattr->cf_acls) { 794 set_posix_acl_entries_dacl(idmap, pndace, fattr, 795 &num_aces, &size, num_aces); 796 goto out; 797 } 798 799 /* owner RID */ 800 uid = from_kuid(&init_user_ns, fattr->cf_uid); 801 if (uid) 802 sid = &server_conf.domain_sid; 803 else 804 sid = &sid_unix_users; 805 ace_size = fill_ace_for_sid(pace, sid, ACCESS_ALLOWED, 0, 806 fattr->cf_mode, 0700); 807 pace->sid.sub_auth[pace->sid.num_subauth++] = cpu_to_le32(uid); 808 pace->size = cpu_to_le16(ace_size + 4); 809 size += le16_to_cpu(pace->size); 810 pace = (struct smb_ace *)((char *)pndace + size); 811 812 /* Group RID */ 813 ace_size = fill_ace_for_sid(pace, &sid_unix_groups, 814 ACCESS_ALLOWED, 0, fattr->cf_mode, 0070); 815 pace->sid.sub_auth[pace->sid.num_subauth++] = 816 cpu_to_le32(from_kgid(&init_user_ns, fattr->cf_gid)); 817 pace->size = cpu_to_le16(ace_size + 4); 818 size += le16_to_cpu(pace->size); 819 pace = (struct smb_ace *)((char *)pndace + size); 820 num_aces = 3; 821 822 if (S_ISDIR(fattr->cf_mode)) { 823 pace = (struct smb_ace *)((char *)pndace + size); 824 825 /* creator owner */ 826 size += fill_ace_for_sid(pace, &creator_owner, ACCESS_ALLOWED, 827 0x0b, fattr->cf_mode, 0700); 828 pace = (struct smb_ace *)((char *)pndace + size); 829 830 /* creator group */ 831 size += fill_ace_for_sid(pace, &creator_group, ACCESS_ALLOWED, 832 0x0b, fattr->cf_mode, 0070); 833 pace = (struct smb_ace *)((char *)pndace + size); 834 num_aces = 5; 835 } 836 837 /* other */ 838 size += fill_ace_for_sid(pace, &sid_everyone, ACCESS_ALLOWED, 0, 839 fattr->cf_mode, 0007); 840 841 out: 842 pndacl->num_aces = cpu_to_le16(num_aces); 843 pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size); 844 } 845 846 static int parse_sid(struct smb_sid *psid, char *end_of_acl) 847 { 848 /* 849 * validate that we do not go past end of ACL - sid must be at least 8 850 * bytes long (assuming no sub-auths - e.g. the null SID 851 */ 852 if (end_of_acl < (char *)psid + 8) { 853 pr_err("ACL too small to parse SID %p\n", psid); 854 return -EINVAL; 855 } 856 857 if (!psid->num_subauth) 858 return 0; 859 860 if (psid->num_subauth > SID_MAX_SUB_AUTHORITIES || 861 end_of_acl < (char *)psid + 8 + sizeof(__le32) * psid->num_subauth) 862 return -EINVAL; 863 864 return 0; 865 } 866 867 /* Convert CIFS ACL to POSIX form */ 868 int parse_sec_desc(struct mnt_idmap *idmap, struct smb_ntsd *pntsd, 869 int acl_len, struct smb_fattr *fattr) 870 { 871 int rc = 0; 872 struct smb_sid *owner_sid_ptr, *group_sid_ptr; 873 struct smb_acl *dacl_ptr; /* no need for SACL ptr */ 874 char *end_of_acl = ((char *)pntsd) + acl_len; 875 __u32 dacloffset; 876 int pntsd_type; 877 878 if (!pntsd) 879 return -EIO; 880 881 if (acl_len < sizeof(struct smb_ntsd)) 882 return -EINVAL; 883 884 owner_sid_ptr = (struct smb_sid *)((char *)pntsd + 885 le32_to_cpu(pntsd->osidoffset)); 886 group_sid_ptr = (struct smb_sid *)((char *)pntsd + 887 le32_to_cpu(pntsd->gsidoffset)); 888 dacloffset = le32_to_cpu(pntsd->dacloffset); 889 dacl_ptr = (struct smb_acl *)((char *)pntsd + dacloffset); 890 ksmbd_debug(SMB, 891 "revision %d type 0x%x ooffset 0x%x goffset 0x%x sacloffset 0x%x dacloffset 0x%x\n", 892 pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset), 893 le32_to_cpu(pntsd->gsidoffset), 894 le32_to_cpu(pntsd->sacloffset), dacloffset); 895 896 pntsd_type = le16_to_cpu(pntsd->type); 897 if (!(pntsd_type & DACL_PRESENT)) { 898 ksmbd_debug(SMB, "DACL_PRESENT in DACL type is not set\n"); 899 return rc; 900 } 901 902 pntsd->type = cpu_to_le16(DACL_PRESENT); 903 904 if (pntsd->osidoffset) { 905 if (le32_to_cpu(pntsd->osidoffset) < sizeof(struct smb_ntsd)) 906 return -EINVAL; 907 908 rc = parse_sid(owner_sid_ptr, end_of_acl); 909 if (rc) { 910 pr_err("%s: Error %d parsing Owner SID\n", __func__, rc); 911 return rc; 912 } 913 914 rc = sid_to_id(idmap, owner_sid_ptr, SIDOWNER, fattr); 915 if (rc) { 916 ksmbd_debug(SMB, "Owner SID has no Unix uid mapping\n"); 917 owner_sid_ptr = NULL; 918 rc = 0; 919 } 920 } 921 922 if (pntsd->gsidoffset) { 923 if (le32_to_cpu(pntsd->gsidoffset) < sizeof(struct smb_ntsd)) 924 return -EINVAL; 925 926 rc = parse_sid(group_sid_ptr, end_of_acl); 927 if (rc) { 928 pr_err("%s: Error %d mapping Owner SID to gid\n", 929 __func__, rc); 930 return rc; 931 } 932 rc = sid_to_id(idmap, group_sid_ptr, SIDUNIX_GROUP, fattr); 933 if (rc) { 934 ksmbd_debug(SMB, "Group SID has no Unix gid mapping\n"); 935 group_sid_ptr = NULL; 936 rc = 0; 937 } 938 } 939 940 if ((pntsd_type & (DACL_AUTO_INHERITED | DACL_AUTO_INHERIT_REQ)) == 941 (DACL_AUTO_INHERITED | DACL_AUTO_INHERIT_REQ)) 942 pntsd->type |= cpu_to_le16(DACL_AUTO_INHERITED); 943 if (pntsd_type & DACL_PROTECTED) 944 pntsd->type |= cpu_to_le16(DACL_PROTECTED); 945 946 if (dacloffset) { 947 if (dacloffset < sizeof(struct smb_ntsd)) 948 return -EINVAL; 949 950 parse_dacl(idmap, dacl_ptr, end_of_acl, 951 owner_sid_ptr, group_sid_ptr, fattr); 952 } 953 954 return 0; 955 } 956 957 size_t smb_acl_sec_desc_scratch_len(struct smb_fattr *fattr, 958 struct smb_ntsd *ppntsd, int ppntsd_size, int addition_info) 959 { 960 size_t len = sizeof(struct smb_ntsd); 961 size_t tmp; 962 963 if (addition_info & OWNER_SECINFO) 964 len += sizeof(struct smb_sid); 965 if (addition_info & GROUP_SECINFO) 966 len += sizeof(struct smb_sid); 967 if (!(addition_info & DACL_SECINFO)) 968 return len; 969 970 len += sizeof(struct smb_acl); 971 if (ppntsd && ppntsd_size > 0) { 972 unsigned int dacl_offset = le32_to_cpu(ppntsd->dacloffset); 973 974 if (dacl_offset < ppntsd_size && 975 check_add_overflow(len, ppntsd_size - dacl_offset, &len)) 976 return 0; 977 } 978 979 if (fattr->cf_acls) { 980 if (check_mul_overflow((size_t)fattr->cf_acls->a_count, 981 2 * sizeof(struct smb_ace), &tmp) || 982 check_add_overflow(len, tmp, &len)) 983 return 0; 984 } else { 985 /* default/minimum DACL */ 986 if (check_add_overflow(len, 5 * sizeof(struct smb_ace), &len)) 987 return 0; 988 } 989 990 if (fattr->cf_dacls) { 991 if (check_mul_overflow((size_t)fattr->cf_dacls->a_count, 992 sizeof(struct smb_ace), &tmp) || 993 check_add_overflow(len, tmp, &len)) 994 return 0; 995 } 996 997 return len; 998 } 999 1000 /* Convert permission bits from mode to equivalent CIFS ACL */ 1001 int build_sec_desc(struct mnt_idmap *idmap, 1002 struct smb_ntsd *pntsd, struct smb_ntsd *ppntsd, 1003 int ppntsd_size, int addition_info, __u32 *secdesclen, 1004 struct smb_fattr *fattr) 1005 { 1006 int rc = 0; 1007 __u32 offset; 1008 struct smb_sid *owner_sid_ptr, *group_sid_ptr; 1009 struct smb_sid *nowner_sid_ptr, *ngroup_sid_ptr; 1010 struct smb_acl *dacl_ptr = NULL; /* no need for SACL ptr */ 1011 uid_t uid; 1012 gid_t gid; 1013 unsigned int sid_type = SIDOWNER; 1014 1015 nowner_sid_ptr = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP); 1016 if (!nowner_sid_ptr) 1017 return -ENOMEM; 1018 1019 uid = from_kuid(&init_user_ns, fattr->cf_uid); 1020 if (!uid) 1021 sid_type = SIDUNIX_USER; 1022 id_to_sid(uid, sid_type, nowner_sid_ptr); 1023 1024 ngroup_sid_ptr = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP); 1025 if (!ngroup_sid_ptr) { 1026 kfree(nowner_sid_ptr); 1027 return -ENOMEM; 1028 } 1029 1030 gid = from_kgid(&init_user_ns, fattr->cf_gid); 1031 id_to_sid(gid, SIDUNIX_GROUP, ngroup_sid_ptr); 1032 1033 offset = sizeof(struct smb_ntsd); 1034 pntsd->sacloffset = 0; 1035 pntsd->revision = cpu_to_le16(1); 1036 pntsd->type = cpu_to_le16(SELF_RELATIVE); 1037 if (ppntsd) 1038 pntsd->type |= ppntsd->type; 1039 1040 if (addition_info & OWNER_SECINFO) { 1041 pntsd->osidoffset = cpu_to_le32(offset); 1042 owner_sid_ptr = (struct smb_sid *)((char *)pntsd + offset); 1043 smb_copy_sid(owner_sid_ptr, nowner_sid_ptr); 1044 offset += 1 + 1 + 6 + (nowner_sid_ptr->num_subauth * 4); 1045 } 1046 1047 if (addition_info & GROUP_SECINFO) { 1048 pntsd->gsidoffset = cpu_to_le32(offset); 1049 group_sid_ptr = (struct smb_sid *)((char *)pntsd + offset); 1050 smb_copy_sid(group_sid_ptr, ngroup_sid_ptr); 1051 offset += 1 + 1 + 6 + (ngroup_sid_ptr->num_subauth * 4); 1052 } 1053 1054 if (addition_info & DACL_SECINFO) { 1055 pntsd->type |= cpu_to_le16(DACL_PRESENT); 1056 dacl_ptr = (struct smb_acl *)((char *)pntsd + offset); 1057 dacl_ptr->revision = cpu_to_le16(2); 1058 dacl_ptr->size = cpu_to_le16(sizeof(struct smb_acl)); 1059 dacl_ptr->num_aces = 0; 1060 1061 if (!ppntsd) { 1062 set_mode_dacl(idmap, dacl_ptr, fattr); 1063 } else { 1064 struct smb_acl *ppdacl_ptr; 1065 unsigned int dacl_offset = le32_to_cpu(ppntsd->dacloffset); 1066 int ppdacl_size, ntacl_size = ppntsd_size - dacl_offset; 1067 1068 if (!dacl_offset || 1069 (dacl_offset + sizeof(struct smb_acl) > ppntsd_size)) 1070 goto out; 1071 1072 ppdacl_ptr = (struct smb_acl *)((char *)ppntsd + dacl_offset); 1073 ppdacl_size = le16_to_cpu(ppdacl_ptr->size); 1074 if (ppdacl_size > ntacl_size || 1075 ppdacl_size < sizeof(struct smb_acl)) 1076 goto out; 1077 1078 set_ntacl_dacl(idmap, dacl_ptr, ppdacl_ptr, 1079 ntacl_size - sizeof(struct smb_acl), 1080 nowner_sid_ptr, ngroup_sid_ptr, 1081 fattr); 1082 } 1083 pntsd->dacloffset = cpu_to_le32(offset); 1084 offset += le16_to_cpu(dacl_ptr->size); 1085 } 1086 1087 out: 1088 kfree(nowner_sid_ptr); 1089 kfree(ngroup_sid_ptr); 1090 *secdesclen = offset; 1091 return rc; 1092 } 1093 1094 static void smb_set_ace(struct smb_ace *ace, const struct smb_sid *sid, u8 type, 1095 u8 flags, __le32 access_req) 1096 { 1097 ace->type = type; 1098 ace->flags = flags; 1099 ace->access_req = access_req; 1100 smb_copy_sid(&ace->sid, sid); 1101 ace->size = cpu_to_le16(1 + 1 + 2 + 4 + 1 + 1 + 6 + 1102 (ace->sid.num_subauth * 4)); 1103 } 1104 1105 static int smb_append_inherited_ace(struct smb_ace **ace, int *nt_size, 1106 u16 *ace_cnt, const struct smb_sid *sid, 1107 u8 type, u8 flags, __le32 access_req) 1108 { 1109 int ace_size; 1110 1111 smb_set_ace(*ace, sid, type, flags, access_req); 1112 ace_size = le16_to_cpu((*ace)->size); 1113 /* pdacl->size is __le16 and includes struct smb_acl. */ 1114 if (check_add_overflow(*nt_size, ace_size, nt_size) || 1115 *nt_size > U16_MAX - (int)sizeof(struct smb_acl)) 1116 return -EINVAL; 1117 1118 (*ace_cnt)++; 1119 *ace = (struct smb_ace *)((char *)*ace + ace_size); 1120 return 0; 1121 } 1122 1123 static int smb_validate_ntsd_sid(struct smb_ntsd *pntsd, size_t pntsd_size, 1124 unsigned int sid_offset, struct smb_sid **sid, 1125 size_t *sid_size) 1126 { 1127 size_t sid_end; 1128 1129 *sid = NULL; 1130 *sid_size = 0; 1131 1132 if (!sid_offset) 1133 return 0; 1134 1135 if (sid_offset < sizeof(struct smb_ntsd) || 1136 check_add_overflow(sid_offset, (size_t)CIFS_SID_BASE_SIZE, 1137 &sid_end) || 1138 sid_end > pntsd_size) 1139 return -EINVAL; 1140 1141 *sid = (struct smb_sid *)((char *)pntsd + sid_offset); 1142 if ((*sid)->num_subauth > SID_MAX_SUB_AUTHORITIES) 1143 return -EINVAL; 1144 1145 if (check_add_overflow((size_t)CIFS_SID_BASE_SIZE, 1146 sizeof(__le32) * (size_t)(*sid)->num_subauth, 1147 &sid_end)) 1148 return -EINVAL; 1149 1150 if (sid_offset > pntsd_size || sid_end > pntsd_size - sid_offset) 1151 return -EINVAL; 1152 1153 *sid_size = sid_end; 1154 return 0; 1155 } 1156 1157 int smb_inherit_dacl(struct ksmbd_conn *conn, 1158 const struct path *path, 1159 unsigned int uid, unsigned int gid) 1160 { 1161 const struct smb_sid *psid, *creator = NULL; 1162 struct smb_ace *parent_aces, *aces; 1163 struct smb_acl *parent_pdacl; 1164 struct smb_ntsd *parent_pntsd = NULL; 1165 struct smb_sid owner_sid, group_sid; 1166 struct dentry *parent = path->dentry->d_parent; 1167 struct mnt_idmap *idmap = mnt_idmap(path->mnt); 1168 int inherited_flags = 0, flags = 0, i, nt_size = 0, pdacl_size; 1169 int rc = 0, pntsd_type, ppntsd_size, acl_len, aces_size; 1170 unsigned int dacloffset; 1171 size_t dacl_struct_end; 1172 u16 num_aces, ace_cnt = 0; 1173 char *aces_base; 1174 bool is_dir = S_ISDIR(d_inode(path->dentry)->i_mode); 1175 1176 ppntsd_size = ksmbd_vfs_get_sd_xattr(conn, idmap, 1177 parent, &parent_pntsd); 1178 if (ppntsd_size <= 0) 1179 return -ENOENT; 1180 1181 dacloffset = le32_to_cpu(parent_pntsd->dacloffset); 1182 if (!dacloffset || 1183 check_add_overflow(dacloffset, sizeof(struct smb_acl), &dacl_struct_end) || 1184 dacl_struct_end > (size_t)ppntsd_size) { 1185 rc = -EINVAL; 1186 goto free_parent_pntsd; 1187 } 1188 1189 parent_pdacl = (struct smb_acl *)((char *)parent_pntsd + dacloffset); 1190 acl_len = ppntsd_size - dacloffset; 1191 num_aces = le16_to_cpu(parent_pdacl->num_aces); 1192 pntsd_type = le16_to_cpu(parent_pntsd->type); 1193 pdacl_size = le16_to_cpu(parent_pdacl->size); 1194 1195 if (pdacl_size > acl_len || pdacl_size < sizeof(struct smb_acl)) { 1196 rc = -EINVAL; 1197 goto free_parent_pntsd; 1198 } 1199 1200 aces_size = pdacl_size - sizeof(struct smb_acl); 1201 1202 /* 1203 * Validate num_aces against the DACL payload before allocating. 1204 * Each ACE must be at least as large as its fixed-size header 1205 * (up to the SID base), so num_aces cannot exceed the payload 1206 * divided by the minimum ACE size. This mirrors the existing 1207 * check in parse_dacl(). 1208 */ 1209 if (num_aces > aces_size / (offsetof(struct smb_ace, sid) + 1210 offsetof(struct smb_sid, sub_auth) + 1211 sizeof(__le16))) { 1212 rc = -EINVAL; 1213 goto free_parent_pntsd; 1214 } 1215 1216 aces_base = kmalloc_array(num_aces * 2, sizeof(struct smb_ace), 1217 KSMBD_DEFAULT_GFP); 1218 if (!aces_base) { 1219 rc = -ENOMEM; 1220 goto free_parent_pntsd; 1221 } 1222 1223 aces = (struct smb_ace *)aces_base; 1224 parent_aces = (struct smb_ace *)((char *)parent_pdacl + 1225 sizeof(struct smb_acl)); 1226 1227 if (pntsd_type & DACL_AUTO_INHERITED) 1228 inherited_flags = INHERITED_ACE; 1229 1230 for (i = 0; i < num_aces; i++) { 1231 int pace_size; 1232 1233 if (aces_size < offsetof(struct smb_ace, sid) + 1234 CIFS_SID_BASE_SIZE) 1235 break; 1236 1237 pace_size = le16_to_cpu(parent_aces->size); 1238 if (pace_size > aces_size || 1239 pace_size < offsetof(struct smb_ace, sid) + 1240 CIFS_SID_BASE_SIZE) 1241 break; 1242 1243 if (parent_aces->sid.num_subauth > SID_MAX_SUB_AUTHORITIES || 1244 pace_size < offsetof(struct smb_ace, sid) + 1245 CIFS_SID_BASE_SIZE + 1246 sizeof(__le32) * parent_aces->sid.num_subauth) 1247 break; 1248 1249 aces_size -= pace_size; 1250 1251 flags = parent_aces->flags; 1252 if (!smb_inherit_flags(flags, is_dir)) 1253 goto pass; 1254 if (is_dir) { 1255 flags &= ~(INHERIT_ONLY_ACE | INHERITED_ACE); 1256 if (!(flags & CONTAINER_INHERIT_ACE)) 1257 flags |= INHERIT_ONLY_ACE; 1258 if (flags & NO_PROPAGATE_INHERIT_ACE) 1259 flags = 0; 1260 } else { 1261 flags = 0; 1262 } 1263 1264 if (!compare_sids(&creator_owner, &parent_aces->sid)) { 1265 creator = &creator_owner; 1266 id_to_sid(uid, SIDOWNER, &owner_sid); 1267 psid = &owner_sid; 1268 } else if (!compare_sids(&creator_group, &parent_aces->sid)) { 1269 creator = &creator_group; 1270 id_to_sid(gid, SIDUNIX_GROUP, &group_sid); 1271 psid = &group_sid; 1272 } else { 1273 creator = NULL; 1274 psid = &parent_aces->sid; 1275 } 1276 1277 if (is_dir && creator && flags & CONTAINER_INHERIT_ACE) { 1278 rc = smb_append_inherited_ace(&aces, &nt_size, &ace_cnt, 1279 psid, parent_aces->type, 1280 inherited_flags, 1281 parent_aces->access_req); 1282 if (rc) 1283 goto free_aces_base; 1284 flags |= INHERIT_ONLY_ACE; 1285 psid = creator; 1286 } else if (is_dir && !(parent_aces->flags & NO_PROPAGATE_INHERIT_ACE)) { 1287 psid = &parent_aces->sid; 1288 } 1289 1290 rc = smb_append_inherited_ace(&aces, &nt_size, &ace_cnt, psid, 1291 parent_aces->type, 1292 flags | inherited_flags, 1293 parent_aces->access_req); 1294 if (rc) 1295 goto free_aces_base; 1296 pass: 1297 parent_aces = (struct smb_ace *)((char *)parent_aces + pace_size); 1298 } 1299 1300 if (nt_size > 0) { 1301 struct smb_ntsd *pntsd; 1302 struct smb_acl *pdacl; 1303 struct smb_sid *powner_sid = NULL, *pgroup_sid = NULL; 1304 size_t powner_sid_size = 0, pgroup_sid_size = 0, pntsd_size; 1305 size_t pntsd_alloc_size; 1306 1307 rc = smb_validate_ntsd_sid(parent_pntsd, ppntsd_size, 1308 le32_to_cpu(parent_pntsd->osidoffset), 1309 &powner_sid, &powner_sid_size); 1310 if (rc) 1311 goto free_aces_base; 1312 rc = smb_validate_ntsd_sid(parent_pntsd, ppntsd_size, 1313 le32_to_cpu(parent_pntsd->gsidoffset), 1314 &pgroup_sid, &pgroup_sid_size); 1315 if (rc) 1316 goto free_aces_base; 1317 1318 if (check_add_overflow(sizeof(struct smb_ntsd), 1319 (size_t)powner_sid_size, 1320 &pntsd_alloc_size) || 1321 check_add_overflow(pntsd_alloc_size, 1322 (size_t)pgroup_sid_size, 1323 &pntsd_alloc_size) || 1324 check_add_overflow(pntsd_alloc_size, sizeof(struct smb_acl), 1325 &pntsd_alloc_size) || 1326 check_add_overflow(pntsd_alloc_size, (size_t)nt_size, 1327 &pntsd_alloc_size)) { 1328 rc = -EINVAL; 1329 goto free_aces_base; 1330 } 1331 1332 pntsd = kzalloc(pntsd_alloc_size, KSMBD_DEFAULT_GFP); 1333 if (!pntsd) { 1334 rc = -ENOMEM; 1335 goto free_aces_base; 1336 } 1337 1338 pntsd->revision = cpu_to_le16(1); 1339 pntsd->type = cpu_to_le16(SELF_RELATIVE | DACL_PRESENT); 1340 if (le16_to_cpu(parent_pntsd->type) & DACL_AUTO_INHERITED) 1341 pntsd->type |= cpu_to_le16(DACL_AUTO_INHERITED); 1342 pntsd_size = sizeof(struct smb_ntsd); 1343 pntsd->osidoffset = parent_pntsd->osidoffset; 1344 pntsd->gsidoffset = parent_pntsd->gsidoffset; 1345 pntsd->dacloffset = parent_pntsd->dacloffset; 1346 1347 if ((u64)le32_to_cpu(pntsd->osidoffset) + powner_sid_size > 1348 pntsd_alloc_size) { 1349 rc = -EINVAL; 1350 kfree(pntsd); 1351 goto free_aces_base; 1352 } 1353 1354 if ((u64)le32_to_cpu(pntsd->gsidoffset) + pgroup_sid_size > 1355 pntsd_alloc_size) { 1356 rc = -EINVAL; 1357 kfree(pntsd); 1358 goto free_aces_base; 1359 } 1360 1361 if ((u64)le32_to_cpu(pntsd->dacloffset) + sizeof(struct smb_acl) + nt_size > 1362 pntsd_alloc_size) { 1363 rc = -EINVAL; 1364 kfree(pntsd); 1365 goto free_aces_base; 1366 } 1367 1368 if (pntsd->osidoffset) { 1369 struct smb_sid *owner_sid = (struct smb_sid *)((char *)pntsd + 1370 le32_to_cpu(pntsd->osidoffset)); 1371 memcpy(owner_sid, powner_sid, powner_sid_size); 1372 pntsd_size += powner_sid_size; 1373 } 1374 1375 if (pntsd->gsidoffset) { 1376 struct smb_sid *group_sid = (struct smb_sid *)((char *)pntsd + 1377 le32_to_cpu(pntsd->gsidoffset)); 1378 memcpy(group_sid, pgroup_sid, pgroup_sid_size); 1379 pntsd_size += pgroup_sid_size; 1380 } 1381 1382 if (pntsd->dacloffset) { 1383 struct smb_ace *pace; 1384 1385 pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset)); 1386 pdacl->revision = cpu_to_le16(2); 1387 pdacl->size = cpu_to_le16(sizeof(struct smb_acl) + nt_size); 1388 pdacl->num_aces = cpu_to_le16(ace_cnt); 1389 pace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl)); 1390 memcpy(pace, aces_base, nt_size); 1391 pntsd_size += sizeof(struct smb_acl) + nt_size; 1392 } 1393 1394 ksmbd_vfs_set_sd_xattr(conn, idmap, path, pntsd, pntsd_size, false); 1395 kfree(pntsd); 1396 } 1397 1398 free_aces_base: 1399 kfree(aces_base); 1400 free_parent_pntsd: 1401 kfree(parent_pntsd); 1402 return rc; 1403 } 1404 1405 bool smb_inherit_flags(int flags, bool is_dir) 1406 { 1407 if (!is_dir) 1408 return (flags & OBJECT_INHERIT_ACE) != 0; 1409 1410 if (flags & OBJECT_INHERIT_ACE && !(flags & NO_PROPAGATE_INHERIT_ACE)) 1411 return true; 1412 1413 if (flags & CONTAINER_INHERIT_ACE) 1414 return true; 1415 return false; 1416 } 1417 1418 int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path, 1419 __le32 *pdaccess, int uid) 1420 { 1421 struct mnt_idmap *idmap = mnt_idmap(path->mnt); 1422 struct smb_ntsd *pntsd = NULL; 1423 struct smb_acl *pdacl; 1424 struct posix_acl *posix_acls; 1425 int rc = 0, pntsd_size, acl_size, aces_size, pdacl_size; 1426 unsigned int dacl_offset; 1427 size_t dacl_struct_end; 1428 struct smb_sid sid; 1429 int granted = le32_to_cpu(*pdaccess & ~FILE_MAXIMAL_ACCESS_LE); 1430 struct smb_ace *ace; 1431 int i, found = 0; 1432 unsigned int access_bits = 0; 1433 struct smb_ace *others_ace = NULL; 1434 struct posix_acl_entry *pa_entry; 1435 unsigned int sid_type = SIDOWNER; 1436 unsigned short ace_size; 1437 1438 ksmbd_debug(SMB, "check permission using windows acl\n"); 1439 pntsd_size = ksmbd_vfs_get_sd_xattr(conn, idmap, 1440 path->dentry, &pntsd); 1441 if (pntsd_size <= 0 || !pntsd) 1442 goto err_out; 1443 1444 dacl_offset = le32_to_cpu(pntsd->dacloffset); 1445 if (!dacl_offset || 1446 check_add_overflow(dacl_offset, sizeof(struct smb_acl), &dacl_struct_end) || 1447 dacl_struct_end > (size_t)pntsd_size) 1448 goto err_out; 1449 1450 pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset)); 1451 acl_size = pntsd_size - dacl_offset; 1452 pdacl_size = le16_to_cpu(pdacl->size); 1453 1454 if (pdacl_size > acl_size || pdacl_size < sizeof(struct smb_acl)) 1455 goto err_out; 1456 1457 if (!pdacl->num_aces) { 1458 if (!(pdacl_size - sizeof(struct smb_acl)) && 1459 *pdaccess & ~(FILE_READ_CONTROL_LE | FILE_WRITE_DAC_LE)) { 1460 rc = -EACCES; 1461 goto err_out; 1462 } 1463 goto err_out; 1464 } 1465 1466 if (*pdaccess & FILE_MAXIMAL_ACCESS_LE) { 1467 granted = READ_CONTROL | WRITE_DAC | FILE_READ_ATTRIBUTES | 1468 DELETE; 1469 1470 ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl)); 1471 aces_size = acl_size - sizeof(struct smb_acl); 1472 for (i = 0; i < le16_to_cpu(pdacl->num_aces); i++) { 1473 if (aces_size < offsetof(struct smb_ace, sid) + 1474 CIFS_SID_BASE_SIZE) 1475 break; 1476 ace_size = le16_to_cpu(ace->size); 1477 if (ace_size > aces_size || 1478 ace_size < offsetof(struct smb_ace, sid) + 1479 CIFS_SID_BASE_SIZE) 1480 break; 1481 aces_size -= ace_size; 1482 granted |= le32_to_cpu(ace->access_req); 1483 ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size)); 1484 } 1485 } 1486 1487 if (!uid) 1488 sid_type = SIDUNIX_USER; 1489 id_to_sid(uid, sid_type, &sid); 1490 1491 ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl)); 1492 aces_size = acl_size - sizeof(struct smb_acl); 1493 for (i = 0; i < le16_to_cpu(pdacl->num_aces); i++) { 1494 if (aces_size < offsetof(struct smb_ace, sid) + 1495 CIFS_SID_BASE_SIZE) 1496 break; 1497 ace_size = le16_to_cpu(ace->size); 1498 if (ace_size > aces_size || 1499 ace_size < offsetof(struct smb_ace, sid) + 1500 CIFS_SID_BASE_SIZE) 1501 break; 1502 aces_size -= ace_size; 1503 1504 if (ace->sid.num_subauth > SID_MAX_SUB_AUTHORITIES || 1505 ace_size < offsetof(struct smb_ace, sid) + CIFS_SID_BASE_SIZE + 1506 sizeof(__le32) * ace->sid.num_subauth) 1507 break; 1508 1509 if (!compare_sids(&sid, &ace->sid) || 1510 !compare_sids(&sid_unix_NFS_mode, &ace->sid)) { 1511 found = 1; 1512 break; 1513 } 1514 if (!compare_sids(&sid_everyone, &ace->sid)) 1515 others_ace = ace; 1516 1517 ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size)); 1518 } 1519 1520 if (*pdaccess & FILE_MAXIMAL_ACCESS_LE && found) { 1521 granted = READ_CONTROL | WRITE_DAC | FILE_READ_ATTRIBUTES | 1522 DELETE; 1523 1524 granted |= le32_to_cpu(ace->access_req); 1525 1526 if (!pdacl->num_aces) 1527 granted = GENERIC_ALL_FLAGS; 1528 } 1529 1530 if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) { 1531 posix_acls = get_inode_acl(d_inode(path->dentry), ACL_TYPE_ACCESS); 1532 if (!IS_ERR_OR_NULL(posix_acls) && !found) { 1533 unsigned int id = -1; 1534 1535 pa_entry = posix_acls->a_entries; 1536 for (i = 0; i < posix_acls->a_count; i++, pa_entry++) { 1537 if (pa_entry->e_tag == ACL_USER) 1538 id = posix_acl_uid_translate(idmap, pa_entry); 1539 else if (pa_entry->e_tag == ACL_GROUP) 1540 id = posix_acl_gid_translate(idmap, pa_entry); 1541 else 1542 continue; 1543 1544 if (id == uid) { 1545 mode_to_access_flags(pa_entry->e_perm, 1546 0777, 1547 &access_bits); 1548 if (!access_bits) 1549 access_bits = 1550 SET_MINIMUM_RIGHTS; 1551 posix_acl_release(posix_acls); 1552 goto check_access_bits; 1553 } 1554 } 1555 } 1556 if (!IS_ERR_OR_NULL(posix_acls)) 1557 posix_acl_release(posix_acls); 1558 } 1559 1560 if (!found) { 1561 if (others_ace) { 1562 ace = others_ace; 1563 } else { 1564 ksmbd_debug(SMB, "Can't find corresponding sid\n"); 1565 rc = -EACCES; 1566 goto err_out; 1567 } 1568 } 1569 1570 switch (ace->type) { 1571 case ACCESS_ALLOWED_ACE_TYPE: 1572 access_bits = le32_to_cpu(ace->access_req); 1573 break; 1574 case ACCESS_DENIED_ACE_TYPE: 1575 case ACCESS_DENIED_CALLBACK_ACE_TYPE: 1576 access_bits = le32_to_cpu(~ace->access_req); 1577 break; 1578 } 1579 1580 check_access_bits: 1581 if (granted & 1582 ~(access_bits | FILE_READ_ATTRIBUTES | READ_CONTROL | WRITE_DAC | DELETE)) { 1583 ksmbd_debug(SMB, "Access denied with winACL, granted : %x, access_req : %x\n", 1584 granted, le32_to_cpu(ace->access_req)); 1585 rc = -EACCES; 1586 goto err_out; 1587 } 1588 1589 *pdaccess = cpu_to_le32(granted); 1590 err_out: 1591 kfree(pntsd); 1592 return rc; 1593 } 1594 1595 int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon, 1596 const struct path *path, struct smb_ntsd *pntsd, int ntsd_len, 1597 bool type_check, bool get_write) 1598 { 1599 int rc; 1600 struct smb_fattr fattr = {{0}}; 1601 struct inode *inode = d_inode(path->dentry); 1602 struct mnt_idmap *idmap = mnt_idmap(path->mnt); 1603 struct iattr newattrs; 1604 1605 fattr.cf_uid = INVALID_UID; 1606 fattr.cf_gid = INVALID_GID; 1607 fattr.cf_mode = inode->i_mode; 1608 1609 rc = parse_sec_desc(idmap, pntsd, ntsd_len, &fattr); 1610 if (rc) 1611 goto out; 1612 1613 newattrs.ia_valid = ATTR_CTIME; 1614 if (!uid_eq(fattr.cf_uid, INVALID_UID)) { 1615 newattrs.ia_valid |= ATTR_UID; 1616 newattrs.ia_uid = fattr.cf_uid; 1617 } 1618 if (!gid_eq(fattr.cf_gid, INVALID_GID)) { 1619 newattrs.ia_valid |= ATTR_GID; 1620 newattrs.ia_gid = fattr.cf_gid; 1621 } 1622 newattrs.ia_valid |= ATTR_MODE; 1623 newattrs.ia_mode = (inode->i_mode & ~0777) | (fattr.cf_mode & 0777); 1624 1625 ksmbd_vfs_remove_acl_xattrs(idmap, path); 1626 /* Update posix acls */ 1627 if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && fattr.cf_dacls) { 1628 rc = set_posix_acl(idmap, path->dentry, 1629 ACL_TYPE_ACCESS, fattr.cf_acls); 1630 if (rc < 0) 1631 ksmbd_debug(SMB, 1632 "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n", 1633 rc); 1634 if (S_ISDIR(inode->i_mode) && fattr.cf_dacls) { 1635 rc = set_posix_acl(idmap, path->dentry, 1636 ACL_TYPE_DEFAULT, fattr.cf_dacls); 1637 if (rc) 1638 ksmbd_debug(SMB, 1639 "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n", 1640 rc); 1641 } 1642 } 1643 1644 inode_lock(inode); 1645 rc = notify_change(idmap, path->dentry, &newattrs, NULL); 1646 inode_unlock(inode); 1647 if (rc) 1648 goto out; 1649 1650 /* Check it only calling from SD BUFFER context */ 1651 if (type_check && !(le16_to_cpu(pntsd->type) & DACL_PRESENT)) 1652 goto out; 1653 1654 if (test_share_config_flag(tcon->share_conf, KSMBD_SHARE_FLAG_ACL_XATTR)) { 1655 /* Update WinACL in xattr */ 1656 ksmbd_vfs_remove_sd_xattrs(idmap, path); 1657 ksmbd_vfs_set_sd_xattr(conn, idmap, path, pntsd, ntsd_len, 1658 get_write); 1659 } 1660 1661 out: 1662 posix_acl_release(fattr.cf_acls); 1663 posix_acl_release(fattr.cf_dacls); 1664 return rc; 1665 } 1666 1667 void ksmbd_init_domain(u32 *sub_auth) 1668 { 1669 int i; 1670 1671 memcpy(&server_conf.domain_sid, &domain, sizeof(struct smb_sid)); 1672 for (i = 0; i < 3; ++i) 1673 server_conf.domain_sid.sub_auth[i + 1] = cpu_to_le32(sub_auth[i]); 1674 } 1675