1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2018 Samsung Electronics Co., Ltd. 4 * Copyright (C) 2018 Namjae Jeon <linkinjeon@kernel.org> 5 */ 6 7 #include <linux/user_namespace.h> 8 9 #include "smb_common.h" 10 #include "server.h" 11 #include "misc.h" 12 #include "smbstatus.h" 13 #include "connection.h" 14 #include "ksmbd_work.h" 15 #include "mgmt/user_session.h" 16 #include "mgmt/user_config.h" 17 #include "mgmt/tree_connect.h" 18 #include "mgmt/share_config.h" 19 20 /*for shortname implementation */ 21 static const char basechars[43] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%"; 22 #define MANGLE_BASE (sizeof(basechars) / sizeof(char) - 1) 23 #define MAGIC_CHAR '~' 24 #define PERIOD '.' 25 #define mangle(V) ((char)(basechars[(V) % MANGLE_BASE])) 26 27 struct smb_protocol { 28 int index; 29 char *name; 30 char *prot; 31 __u16 prot_id; 32 }; 33 34 static struct smb_protocol smb1_protos[] = { 35 { 36 SMB21_PROT, 37 "\2SMB 2.1", 38 "SMB2_10", 39 SMB21_PROT_ID 40 }, 41 { 42 SMB2X_PROT, 43 "\2SMB 2.???", 44 "SMB2_22", 45 SMB2X_PROT_ID 46 }, 47 }; 48 49 static struct smb_protocol smb2_protos[] = { 50 { 51 SMB21_PROT, 52 "\2SMB 2.1", 53 "SMB2_10", 54 SMB21_PROT_ID 55 }, 56 { 57 SMB30_PROT, 58 "\2SMB 3.0", 59 "SMB3_00", 60 SMB30_PROT_ID 61 }, 62 { 63 SMB302_PROT, 64 "\2SMB 3.02", 65 "SMB3_02", 66 SMB302_PROT_ID 67 }, 68 { 69 SMB311_PROT, 70 "\2SMB 3.1.1", 71 "SMB3_11", 72 SMB311_PROT_ID 73 }, 74 }; 75 76 unsigned int ksmbd_server_side_copy_max_chunk_count(void) 77 { 78 return 256; 79 } 80 81 unsigned int ksmbd_server_side_copy_max_chunk_size(void) 82 { 83 return (2U << 30) - 1; 84 } 85 86 unsigned int ksmbd_server_side_copy_max_total_size(void) 87 { 88 return (2U << 30) - 1; 89 } 90 91 inline int ksmbd_min_protocol(void) 92 { 93 return SMB21_PROT; 94 } 95 96 inline int ksmbd_max_protocol(void) 97 { 98 return SMB311_PROT; 99 } 100 101 int ksmbd_lookup_protocol_idx(char *str) 102 { 103 int offt = ARRAY_SIZE(smb1_protos) - 1; 104 int len = strlen(str); 105 106 while (offt >= 0) { 107 if (!strncmp(str, smb1_protos[offt].prot, len)) { 108 ksmbd_debug(SMB, "selected %s dialect idx = %d\n", 109 smb1_protos[offt].prot, offt); 110 return smb1_protos[offt].index; 111 } 112 offt--; 113 } 114 115 offt = ARRAY_SIZE(smb2_protos) - 1; 116 while (offt >= 0) { 117 if (!strncmp(str, smb2_protos[offt].prot, len)) { 118 ksmbd_debug(SMB, "selected %s dialect idx = %d\n", 119 smb2_protos[offt].prot, offt); 120 return smb2_protos[offt].index; 121 } 122 offt--; 123 } 124 return -1; 125 } 126 127 /** 128 * ksmbd_verify_smb_message() - check for valid smb2 request header 129 * @work: smb work 130 * 131 * check for valid smb signature and packet direction(request/response) 132 * 133 * Return: 0 on success, otherwise -EINVAL 134 */ 135 int ksmbd_verify_smb_message(struct ksmbd_work *work) 136 { 137 struct smb2_hdr *smb2_hdr = ksmbd_req_buf_next(work); 138 struct smb_hdr *hdr; 139 140 if (smb2_hdr->ProtocolId == SMB2_PROTO_NUMBER) 141 return ksmbd_smb2_check_message(work); 142 143 hdr = work->request_buf; 144 if (*(__le32 *)hdr->Protocol == SMB1_PROTO_NUMBER && 145 hdr->Command == SMB_COM_NEGOTIATE) { 146 work->conn->outstanding_credits++; 147 return 0; 148 } 149 150 return -EINVAL; 151 } 152 153 /** 154 * ksmbd_smb_request() - check for valid smb request type 155 * @conn: connection instance 156 * 157 * Return: true on success, otherwise false 158 */ 159 bool ksmbd_smb_request(struct ksmbd_conn *conn) 160 { 161 __le32 *proto = (__le32 *)smb2_get_msg(conn->request_buf); 162 163 if (*proto == SMB2_COMPRESSION_TRANSFORM_ID) { 164 pr_err_ratelimited("smb2 compression not support yet"); 165 return false; 166 } 167 168 if (*proto != SMB1_PROTO_NUMBER && 169 *proto != SMB2_PROTO_NUMBER && 170 *proto != SMB2_TRANSFORM_PROTO_NUM) 171 return false; 172 173 return true; 174 } 175 176 static bool supported_protocol(int idx) 177 { 178 if (idx == SMB2X_PROT && 179 (server_conf.min_protocol >= SMB21_PROT || 180 server_conf.max_protocol <= SMB311_PROT)) 181 return true; 182 183 return (server_conf.min_protocol <= idx && 184 idx <= server_conf.max_protocol); 185 } 186 187 static char *next_dialect(char *dialect, int *next_off, int bcount) 188 { 189 dialect = dialect + *next_off; 190 *next_off = strnlen(dialect, bcount); 191 if (dialect[*next_off] != '\0') 192 return NULL; 193 return dialect; 194 } 195 196 static int ksmbd_lookup_dialect_by_name(char *cli_dialects, __le16 byte_count) 197 { 198 int i, seq_num, bcount, next; 199 char *dialect; 200 201 for (i = ARRAY_SIZE(smb1_protos) - 1; i >= 0; i--) { 202 seq_num = 0; 203 next = 0; 204 dialect = cli_dialects; 205 bcount = le16_to_cpu(byte_count); 206 do { 207 dialect = next_dialect(dialect, &next, bcount); 208 if (!dialect) 209 break; 210 ksmbd_debug(SMB, "client requested dialect %s\n", 211 dialect); 212 if (!strcmp(dialect, smb1_protos[i].name)) { 213 if (supported_protocol(smb1_protos[i].index)) { 214 ksmbd_debug(SMB, 215 "selected %s dialect\n", 216 smb1_protos[i].name); 217 if (smb1_protos[i].index == SMB1_PROT) 218 return seq_num; 219 return smb1_protos[i].prot_id; 220 } 221 } 222 seq_num++; 223 bcount -= (++next); 224 } while (bcount > 0); 225 } 226 227 return BAD_PROT_ID; 228 } 229 230 int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count) 231 { 232 int i; 233 int count; 234 235 for (i = ARRAY_SIZE(smb2_protos) - 1; i >= 0; i--) { 236 count = le16_to_cpu(dialects_count); 237 while (--count >= 0) { 238 ksmbd_debug(SMB, "client requested dialect 0x%x\n", 239 le16_to_cpu(cli_dialects[count])); 240 if (le16_to_cpu(cli_dialects[count]) != 241 smb2_protos[i].prot_id) 242 continue; 243 244 if (supported_protocol(smb2_protos[i].index)) { 245 ksmbd_debug(SMB, "selected %s dialect\n", 246 smb2_protos[i].name); 247 return smb2_protos[i].prot_id; 248 } 249 } 250 } 251 252 return BAD_PROT_ID; 253 } 254 255 static int ksmbd_negotiate_smb_dialect(void *buf) 256 { 257 int smb_buf_length = get_rfc1002_len(buf); 258 __le32 proto = ((struct smb2_hdr *)smb2_get_msg(buf))->ProtocolId; 259 260 if (proto == SMB2_PROTO_NUMBER) { 261 struct smb2_negotiate_req *req; 262 int smb2_neg_size = 263 offsetof(struct smb2_negotiate_req, Dialects); 264 265 req = (struct smb2_negotiate_req *)smb2_get_msg(buf); 266 if (smb2_neg_size > smb_buf_length) 267 goto err_out; 268 269 if (struct_size(req, Dialects, le16_to_cpu(req->DialectCount)) > 270 smb_buf_length) 271 goto err_out; 272 273 return ksmbd_lookup_dialect_by_id(req->Dialects, 274 req->DialectCount); 275 } 276 277 proto = *(__le32 *)((struct smb_hdr *)buf)->Protocol; 278 if (proto == SMB1_PROTO_NUMBER) { 279 struct smb_negotiate_req *req; 280 281 req = (struct smb_negotiate_req *)buf; 282 if (le16_to_cpu(req->ByteCount) < 2) 283 goto err_out; 284 285 if (offsetof(struct smb_negotiate_req, DialectsArray) - 4 + 286 le16_to_cpu(req->ByteCount) > smb_buf_length) { 287 goto err_out; 288 } 289 290 return ksmbd_lookup_dialect_by_name(req->DialectsArray, 291 req->ByteCount); 292 } 293 294 err_out: 295 return BAD_PROT_ID; 296 } 297 298 #define SMB_COM_NEGOTIATE_EX 0x0 299 300 /** 301 * get_smb1_cmd_val() - get smb command value from smb header 302 * @work: smb work containing smb header 303 * 304 * Return: smb command value 305 */ 306 static u16 get_smb1_cmd_val(struct ksmbd_work *work) 307 { 308 return SMB_COM_NEGOTIATE_EX; 309 } 310 311 /** 312 * init_smb1_rsp_hdr() - initialize smb negotiate response header 313 * @work: smb work containing smb request 314 * 315 * Return: 0 on success, otherwise -EINVAL 316 */ 317 static int init_smb1_rsp_hdr(struct ksmbd_work *work) 318 { 319 struct smb_hdr *rsp_hdr = (struct smb_hdr *)work->response_buf; 320 struct smb_hdr *rcv_hdr = (struct smb_hdr *)work->request_buf; 321 322 rsp_hdr->Command = SMB_COM_NEGOTIATE; 323 *(__le32 *)rsp_hdr->Protocol = SMB1_PROTO_NUMBER; 324 rsp_hdr->Flags = SMBFLG_RESPONSE; 325 rsp_hdr->Flags2 = SMBFLG2_UNICODE | SMBFLG2_ERR_STATUS | 326 SMBFLG2_EXT_SEC | SMBFLG2_IS_LONG_NAME; 327 rsp_hdr->Pid = rcv_hdr->Pid; 328 rsp_hdr->Mid = rcv_hdr->Mid; 329 return 0; 330 } 331 332 /** 333 * smb1_check_user_session() - check for valid session for a user 334 * @work: smb work containing smb request buffer 335 * 336 * Return: 0 on success, otherwise error 337 */ 338 static int smb1_check_user_session(struct ksmbd_work *work) 339 { 340 unsigned int cmd = work->conn->ops->get_cmd_val(work); 341 342 if (cmd == SMB_COM_NEGOTIATE_EX) 343 return 0; 344 345 return -EINVAL; 346 } 347 348 /** 349 * smb1_allocate_rsp_buf() - allocate response buffer for a command 350 * @work: smb work containing smb request 351 * 352 * Return: 0 on success, otherwise -ENOMEM 353 */ 354 static int smb1_allocate_rsp_buf(struct ksmbd_work *work) 355 { 356 work->response_buf = kzalloc(MAX_CIFS_SMALL_BUFFER_SIZE, 357 GFP_KERNEL); 358 work->response_sz = MAX_CIFS_SMALL_BUFFER_SIZE; 359 360 if (!work->response_buf) { 361 pr_err("Failed to allocate %u bytes buffer\n", 362 MAX_CIFS_SMALL_BUFFER_SIZE); 363 return -ENOMEM; 364 } 365 366 return 0; 367 } 368 369 static struct smb_version_ops smb1_server_ops = { 370 .get_cmd_val = get_smb1_cmd_val, 371 .init_rsp_hdr = init_smb1_rsp_hdr, 372 .allocate_rsp_buf = smb1_allocate_rsp_buf, 373 .check_user_session = smb1_check_user_session, 374 }; 375 376 static int smb1_negotiate(struct ksmbd_work *work) 377 { 378 return ksmbd_smb_negotiate_common(work, SMB_COM_NEGOTIATE); 379 } 380 381 static struct smb_version_cmds smb1_server_cmds[1] = { 382 [SMB_COM_NEGOTIATE_EX] = { .proc = smb1_negotiate, }, 383 }; 384 385 static int init_smb1_server(struct ksmbd_conn *conn) 386 { 387 conn->ops = &smb1_server_ops; 388 conn->cmds = smb1_server_cmds; 389 conn->max_cmds = ARRAY_SIZE(smb1_server_cmds); 390 return 0; 391 } 392 393 int ksmbd_init_smb_server(struct ksmbd_work *work) 394 { 395 struct ksmbd_conn *conn = work->conn; 396 __le32 proto; 397 398 proto = *(__le32 *)((struct smb_hdr *)work->request_buf)->Protocol; 399 if (conn->need_neg == false) { 400 if (proto == SMB1_PROTO_NUMBER) 401 return -EINVAL; 402 return 0; 403 } 404 405 if (proto == SMB1_PROTO_NUMBER) 406 return init_smb1_server(conn); 407 return init_smb3_11_server(conn); 408 } 409 410 int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level, 411 struct ksmbd_file *dir, 412 struct ksmbd_dir_info *d_info, 413 char *search_pattern, 414 int (*fn)(struct ksmbd_conn *, int, 415 struct ksmbd_dir_info *, 416 struct ksmbd_kstat *)) 417 { 418 int i, rc = 0; 419 struct ksmbd_conn *conn = work->conn; 420 struct mnt_idmap *idmap = file_mnt_idmap(dir->filp); 421 422 for (i = 0; i < 2; i++) { 423 struct kstat kstat; 424 struct ksmbd_kstat ksmbd_kstat; 425 struct dentry *dentry; 426 427 if (!dir->dot_dotdot[i]) { /* fill dot entry info */ 428 if (i == 0) { 429 d_info->name = "."; 430 d_info->name_len = 1; 431 dentry = dir->filp->f_path.dentry; 432 } else { 433 d_info->name = ".."; 434 d_info->name_len = 2; 435 dentry = dir->filp->f_path.dentry->d_parent; 436 } 437 438 if (!match_pattern(d_info->name, d_info->name_len, 439 search_pattern)) { 440 dir->dot_dotdot[i] = 1; 441 continue; 442 } 443 444 ksmbd_kstat.kstat = &kstat; 445 ksmbd_vfs_fill_dentry_attrs(work, 446 idmap, 447 dentry, 448 &ksmbd_kstat); 449 rc = fn(conn, info_level, d_info, &ksmbd_kstat); 450 if (rc) 451 break; 452 if (d_info->out_buf_len <= 0) 453 break; 454 455 dir->dot_dotdot[i] = 1; 456 if (d_info->flags & SMB2_RETURN_SINGLE_ENTRY) { 457 d_info->out_buf_len = 0; 458 break; 459 } 460 } 461 } 462 463 return rc; 464 } 465 466 /** 467 * ksmbd_extract_shortname() - get shortname from long filename 468 * @conn: connection instance 469 * @longname: source long filename 470 * @shortname: destination short filename 471 * 472 * Return: shortname length or 0 when source long name is '.' or '..' 473 * TODO: Though this function comforms the restriction of 8.3 Filename spec, 474 * but the result is different with Windows 7's one. need to check. 475 */ 476 int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname, 477 char *shortname) 478 { 479 const char *p; 480 char base[9], extension[4]; 481 char out[13] = {0}; 482 int baselen = 0; 483 int extlen = 0, len = 0; 484 unsigned int csum = 0; 485 const unsigned char *ptr; 486 bool dot_present = true; 487 488 p = longname; 489 if ((*p == '.') || (!(strcmp(p, "..")))) { 490 /*no mangling required */ 491 return 0; 492 } 493 494 p = strrchr(longname, '.'); 495 if (p == longname) { /*name starts with a dot*/ 496 strscpy(extension, "___", strlen("___")); 497 } else { 498 if (p) { 499 p++; 500 while (*p && extlen < 3) { 501 if (*p != '.') 502 extension[extlen++] = toupper(*p); 503 p++; 504 } 505 extension[extlen] = '\0'; 506 } else { 507 dot_present = false; 508 } 509 } 510 511 p = longname; 512 if (*p == '.') { 513 p++; 514 longname++; 515 } 516 while (*p && (baselen < 5)) { 517 if (*p != '.') 518 base[baselen++] = toupper(*p); 519 p++; 520 } 521 522 base[baselen] = MAGIC_CHAR; 523 memcpy(out, base, baselen + 1); 524 525 ptr = longname; 526 len = strlen(longname); 527 for (; len > 0; len--, ptr++) 528 csum += *ptr; 529 530 csum = csum % (MANGLE_BASE * MANGLE_BASE); 531 out[baselen + 1] = mangle(csum / MANGLE_BASE); 532 out[baselen + 2] = mangle(csum); 533 out[baselen + 3] = PERIOD; 534 535 if (dot_present) 536 memcpy(out + baselen + 4, extension, 4); 537 else 538 out[baselen + 4] = '\0'; 539 smbConvertToUTF16((__le16 *)shortname, out, PATH_MAX, 540 conn->local_nls, 0); 541 len = strlen(out) * 2; 542 return len; 543 } 544 545 static int __smb2_negotiate(struct ksmbd_conn *conn) 546 { 547 return (conn->dialect >= SMB20_PROT_ID && 548 conn->dialect <= SMB311_PROT_ID); 549 } 550 551 static int smb_handle_negotiate(struct ksmbd_work *work) 552 { 553 struct smb_negotiate_rsp *neg_rsp = work->response_buf; 554 555 ksmbd_debug(SMB, "Unsupported SMB1 protocol\n"); 556 557 if (ksmbd_iov_pin_rsp(work, (void *)neg_rsp, 558 sizeof(struct smb_negotiate_rsp) - 4)) 559 return -ENOMEM; 560 561 neg_rsp->hdr.Status.CifsError = STATUS_SUCCESS; 562 neg_rsp->hdr.WordCount = 1; 563 neg_rsp->DialectIndex = cpu_to_le16(work->conn->dialect); 564 neg_rsp->ByteCount = 0; 565 return 0; 566 } 567 568 int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command) 569 { 570 struct ksmbd_conn *conn = work->conn; 571 int ret; 572 573 conn->dialect = 574 ksmbd_negotiate_smb_dialect(work->request_buf); 575 ksmbd_debug(SMB, "conn->dialect 0x%x\n", conn->dialect); 576 577 if (command == SMB2_NEGOTIATE_HE) { 578 ret = smb2_handle_negotiate(work); 579 return ret; 580 } 581 582 if (command == SMB_COM_NEGOTIATE) { 583 if (__smb2_negotiate(conn)) { 584 init_smb3_11_server(conn); 585 init_smb2_neg_rsp(work); 586 ksmbd_debug(SMB, "Upgrade to SMB2 negotiation\n"); 587 return 0; 588 } 589 return smb_handle_negotiate(work); 590 } 591 592 pr_err("Unknown SMB negotiation command: %u\n", command); 593 return -EINVAL; 594 } 595 596 enum SHARED_MODE_ERRORS { 597 SHARE_DELETE_ERROR, 598 SHARE_READ_ERROR, 599 SHARE_WRITE_ERROR, 600 FILE_READ_ERROR, 601 FILE_WRITE_ERROR, 602 FILE_DELETE_ERROR, 603 }; 604 605 static const char * const shared_mode_errors[] = { 606 "Current access mode does not permit SHARE_DELETE", 607 "Current access mode does not permit SHARE_READ", 608 "Current access mode does not permit SHARE_WRITE", 609 "Desired access mode does not permit FILE_READ", 610 "Desired access mode does not permit FILE_WRITE", 611 "Desired access mode does not permit FILE_DELETE", 612 }; 613 614 static void smb_shared_mode_error(int error, struct ksmbd_file *prev_fp, 615 struct ksmbd_file *curr_fp) 616 { 617 ksmbd_debug(SMB, "%s\n", shared_mode_errors[error]); 618 ksmbd_debug(SMB, "Current mode: 0x%x Desired mode: 0x%x\n", 619 prev_fp->saccess, curr_fp->daccess); 620 } 621 622 int ksmbd_smb_check_shared_mode(struct file *filp, struct ksmbd_file *curr_fp) 623 { 624 int rc = 0; 625 struct ksmbd_file *prev_fp; 626 627 /* 628 * Lookup fp in master fp list, and check desired access and 629 * shared mode between previous open and current open. 630 */ 631 read_lock(&curr_fp->f_ci->m_lock); 632 list_for_each_entry(prev_fp, &curr_fp->f_ci->m_fp_list, node) { 633 if (file_inode(filp) != file_inode(prev_fp->filp)) 634 continue; 635 636 if (filp == prev_fp->filp) 637 continue; 638 639 if (ksmbd_stream_fd(prev_fp) && ksmbd_stream_fd(curr_fp)) 640 if (strcmp(prev_fp->stream.name, curr_fp->stream.name)) 641 continue; 642 643 if (prev_fp->attrib_only != curr_fp->attrib_only) 644 continue; 645 646 if (!(prev_fp->saccess & FILE_SHARE_DELETE_LE) && 647 curr_fp->daccess & FILE_DELETE_LE) { 648 smb_shared_mode_error(SHARE_DELETE_ERROR, 649 prev_fp, 650 curr_fp); 651 rc = -EPERM; 652 break; 653 } 654 655 /* 656 * Only check FILE_SHARE_DELETE if stream opened and 657 * normal file opened. 658 */ 659 if (ksmbd_stream_fd(prev_fp) && !ksmbd_stream_fd(curr_fp)) 660 continue; 661 662 if (!(prev_fp->saccess & FILE_SHARE_READ_LE) && 663 curr_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE)) { 664 smb_shared_mode_error(SHARE_READ_ERROR, 665 prev_fp, 666 curr_fp); 667 rc = -EPERM; 668 break; 669 } 670 671 if (!(prev_fp->saccess & FILE_SHARE_WRITE_LE) && 672 curr_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE)) { 673 smb_shared_mode_error(SHARE_WRITE_ERROR, 674 prev_fp, 675 curr_fp); 676 rc = -EPERM; 677 break; 678 } 679 680 if (prev_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE) && 681 !(curr_fp->saccess & FILE_SHARE_READ_LE)) { 682 smb_shared_mode_error(FILE_READ_ERROR, 683 prev_fp, 684 curr_fp); 685 rc = -EPERM; 686 break; 687 } 688 689 if (prev_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE) && 690 !(curr_fp->saccess & FILE_SHARE_WRITE_LE)) { 691 smb_shared_mode_error(FILE_WRITE_ERROR, 692 prev_fp, 693 curr_fp); 694 rc = -EPERM; 695 break; 696 } 697 698 if (prev_fp->daccess & FILE_DELETE_LE && 699 !(curr_fp->saccess & FILE_SHARE_DELETE_LE)) { 700 smb_shared_mode_error(FILE_DELETE_ERROR, 701 prev_fp, 702 curr_fp); 703 rc = -EPERM; 704 break; 705 } 706 } 707 read_unlock(&curr_fp->f_ci->m_lock); 708 709 return rc; 710 } 711 712 bool is_asterisk(char *p) 713 { 714 return p && p[0] == '*'; 715 } 716 717 int ksmbd_override_fsids(struct ksmbd_work *work) 718 { 719 struct ksmbd_session *sess = work->sess; 720 struct ksmbd_share_config *share = work->tcon->share_conf; 721 struct cred *cred; 722 struct group_info *gi; 723 unsigned int uid; 724 unsigned int gid; 725 726 uid = user_uid(sess->user); 727 gid = user_gid(sess->user); 728 if (share->force_uid != KSMBD_SHARE_INVALID_UID) 729 uid = share->force_uid; 730 if (share->force_gid != KSMBD_SHARE_INVALID_GID) 731 gid = share->force_gid; 732 733 cred = prepare_kernel_cred(&init_task); 734 if (!cred) 735 return -ENOMEM; 736 737 cred->fsuid = make_kuid(&init_user_ns, uid); 738 cred->fsgid = make_kgid(&init_user_ns, gid); 739 740 gi = groups_alloc(0); 741 if (!gi) { 742 abort_creds(cred); 743 return -ENOMEM; 744 } 745 set_groups(cred, gi); 746 put_group_info(gi); 747 748 if (!uid_eq(cred->fsuid, GLOBAL_ROOT_UID)) 749 cred->cap_effective = cap_drop_fs_set(cred->cap_effective); 750 751 WARN_ON(work->saved_cred); 752 work->saved_cred = override_creds(cred); 753 if (!work->saved_cred) { 754 abort_creds(cred); 755 return -EINVAL; 756 } 757 return 0; 758 } 759 760 void ksmbd_revert_fsids(struct ksmbd_work *work) 761 { 762 const struct cred *cred; 763 764 WARN_ON(!work->saved_cred); 765 766 cred = current_cred(); 767 revert_creds(work->saved_cred); 768 put_cred(cred); 769 work->saved_cred = NULL; 770 } 771 772 __le32 smb_map_generic_desired_access(__le32 daccess) 773 { 774 if (daccess & FILE_GENERIC_READ_LE) { 775 daccess |= cpu_to_le32(GENERIC_READ_FLAGS); 776 daccess &= ~FILE_GENERIC_READ_LE; 777 } 778 779 if (daccess & FILE_GENERIC_WRITE_LE) { 780 daccess |= cpu_to_le32(GENERIC_WRITE_FLAGS); 781 daccess &= ~FILE_GENERIC_WRITE_LE; 782 } 783 784 if (daccess & FILE_GENERIC_EXECUTE_LE) { 785 daccess |= cpu_to_le32(GENERIC_EXECUTE_FLAGS); 786 daccess &= ~FILE_GENERIC_EXECUTE_LE; 787 } 788 789 if (daccess & FILE_GENERIC_ALL_LE) { 790 daccess |= cpu_to_le32(GENERIC_ALL_FLAGS); 791 daccess &= ~FILE_GENERIC_ALL_LE; 792 } 793 794 return daccess; 795 } 796