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 (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) > 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 /* 323 * Remove 4 byte direct TCP header. 324 */ 325 *(__be32 *)work->response_buf = 326 cpu_to_be32(sizeof(struct smb_hdr) - 4); 327 328 rsp_hdr->Command = SMB_COM_NEGOTIATE; 329 *(__le32 *)rsp_hdr->Protocol = SMB1_PROTO_NUMBER; 330 rsp_hdr->Flags = SMBFLG_RESPONSE; 331 rsp_hdr->Flags2 = SMBFLG2_UNICODE | SMBFLG2_ERR_STATUS | 332 SMBFLG2_EXT_SEC | SMBFLG2_IS_LONG_NAME; 333 rsp_hdr->Pid = rcv_hdr->Pid; 334 rsp_hdr->Mid = rcv_hdr->Mid; 335 return 0; 336 } 337 338 /** 339 * smb1_check_user_session() - check for valid session for a user 340 * @work: smb work containing smb request buffer 341 * 342 * Return: 0 on success, otherwise error 343 */ 344 static int smb1_check_user_session(struct ksmbd_work *work) 345 { 346 unsigned int cmd = work->conn->ops->get_cmd_val(work); 347 348 if (cmd == SMB_COM_NEGOTIATE_EX) 349 return 0; 350 351 return -EINVAL; 352 } 353 354 /** 355 * smb1_allocate_rsp_buf() - allocate response buffer for a command 356 * @work: smb work containing smb request 357 * 358 * Return: 0 on success, otherwise -ENOMEM 359 */ 360 static int smb1_allocate_rsp_buf(struct ksmbd_work *work) 361 { 362 work->response_buf = kmalloc(MAX_CIFS_SMALL_BUFFER_SIZE, 363 GFP_KERNEL | __GFP_ZERO); 364 work->response_sz = MAX_CIFS_SMALL_BUFFER_SIZE; 365 366 if (!work->response_buf) { 367 pr_err("Failed to allocate %u bytes buffer\n", 368 MAX_CIFS_SMALL_BUFFER_SIZE); 369 return -ENOMEM; 370 } 371 372 return 0; 373 } 374 375 static struct smb_version_ops smb1_server_ops = { 376 .get_cmd_val = get_smb1_cmd_val, 377 .init_rsp_hdr = init_smb1_rsp_hdr, 378 .allocate_rsp_buf = smb1_allocate_rsp_buf, 379 .check_user_session = smb1_check_user_session, 380 }; 381 382 static int smb1_negotiate(struct ksmbd_work *work) 383 { 384 return ksmbd_smb_negotiate_common(work, SMB_COM_NEGOTIATE); 385 } 386 387 static struct smb_version_cmds smb1_server_cmds[1] = { 388 [SMB_COM_NEGOTIATE_EX] = { .proc = smb1_negotiate, }, 389 }; 390 391 static void init_smb1_server(struct ksmbd_conn *conn) 392 { 393 conn->ops = &smb1_server_ops; 394 conn->cmds = smb1_server_cmds; 395 conn->max_cmds = ARRAY_SIZE(smb1_server_cmds); 396 } 397 398 void ksmbd_init_smb_server(struct ksmbd_work *work) 399 { 400 struct ksmbd_conn *conn = work->conn; 401 __le32 proto; 402 403 if (conn->need_neg == false) 404 return; 405 406 proto = *(__le32 *)((struct smb_hdr *)work->request_buf)->Protocol; 407 if (proto == SMB1_PROTO_NUMBER) 408 init_smb1_server(conn); 409 else 410 init_smb3_11_server(conn); 411 } 412 413 int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level, 414 struct ksmbd_file *dir, 415 struct ksmbd_dir_info *d_info, 416 char *search_pattern, 417 int (*fn)(struct ksmbd_conn *, int, 418 struct ksmbd_dir_info *, 419 struct ksmbd_kstat *)) 420 { 421 int i, rc = 0; 422 struct ksmbd_conn *conn = work->conn; 423 struct mnt_idmap *idmap = file_mnt_idmap(dir->filp); 424 425 for (i = 0; i < 2; i++) { 426 struct kstat kstat; 427 struct ksmbd_kstat ksmbd_kstat; 428 struct dentry *dentry; 429 430 if (!dir->dot_dotdot[i]) { /* fill dot entry info */ 431 if (i == 0) { 432 d_info->name = "."; 433 d_info->name_len = 1; 434 dentry = dir->filp->f_path.dentry; 435 } else { 436 d_info->name = ".."; 437 d_info->name_len = 2; 438 dentry = dir->filp->f_path.dentry->d_parent; 439 } 440 441 if (!match_pattern(d_info->name, d_info->name_len, 442 search_pattern)) { 443 dir->dot_dotdot[i] = 1; 444 continue; 445 } 446 447 ksmbd_kstat.kstat = &kstat; 448 ksmbd_vfs_fill_dentry_attrs(work, 449 idmap, 450 dentry, 451 &ksmbd_kstat); 452 rc = fn(conn, info_level, d_info, &ksmbd_kstat); 453 if (rc) 454 break; 455 if (d_info->out_buf_len <= 0) 456 break; 457 458 dir->dot_dotdot[i] = 1; 459 if (d_info->flags & SMB2_RETURN_SINGLE_ENTRY) { 460 d_info->out_buf_len = 0; 461 break; 462 } 463 } 464 } 465 466 return rc; 467 } 468 469 /** 470 * ksmbd_extract_shortname() - get shortname from long filename 471 * @conn: connection instance 472 * @longname: source long filename 473 * @shortname: destination short filename 474 * 475 * Return: shortname length or 0 when source long name is '.' or '..' 476 * TODO: Though this function comforms the restriction of 8.3 Filename spec, 477 * but the result is different with Windows 7's one. need to check. 478 */ 479 int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname, 480 char *shortname) 481 { 482 const char *p; 483 char base[9], extension[4]; 484 char out[13] = {0}; 485 int baselen = 0; 486 int extlen = 0, len = 0; 487 unsigned int csum = 0; 488 const unsigned char *ptr; 489 bool dot_present = true; 490 491 p = longname; 492 if ((*p == '.') || (!(strcmp(p, "..")))) { 493 /*no mangling required */ 494 return 0; 495 } 496 497 p = strrchr(longname, '.'); 498 if (p == longname) { /*name starts with a dot*/ 499 strscpy(extension, "___", strlen("___")); 500 } else { 501 if (p) { 502 p++; 503 while (*p && extlen < 3) { 504 if (*p != '.') 505 extension[extlen++] = toupper(*p); 506 p++; 507 } 508 extension[extlen] = '\0'; 509 } else { 510 dot_present = false; 511 } 512 } 513 514 p = longname; 515 if (*p == '.') { 516 p++; 517 longname++; 518 } 519 while (*p && (baselen < 5)) { 520 if (*p != '.') 521 base[baselen++] = toupper(*p); 522 p++; 523 } 524 525 base[baselen] = MAGIC_CHAR; 526 memcpy(out, base, baselen + 1); 527 528 ptr = longname; 529 len = strlen(longname); 530 for (; len > 0; len--, ptr++) 531 csum += *ptr; 532 533 csum = csum % (MANGLE_BASE * MANGLE_BASE); 534 out[baselen + 1] = mangle(csum / MANGLE_BASE); 535 out[baselen + 2] = mangle(csum); 536 out[baselen + 3] = PERIOD; 537 538 if (dot_present) 539 memcpy(&out[baselen + 4], extension, 4); 540 else 541 out[baselen + 4] = '\0'; 542 smbConvertToUTF16((__le16 *)shortname, out, PATH_MAX, 543 conn->local_nls, 0); 544 len = strlen(out) * 2; 545 return len; 546 } 547 548 static int __smb2_negotiate(struct ksmbd_conn *conn) 549 { 550 return (conn->dialect >= SMB20_PROT_ID && 551 conn->dialect <= SMB311_PROT_ID); 552 } 553 554 static int smb_handle_negotiate(struct ksmbd_work *work) 555 { 556 struct smb_negotiate_rsp *neg_rsp = work->response_buf; 557 558 ksmbd_debug(SMB, "Unsupported SMB1 protocol\n"); 559 560 /* Add 2 byte bcc and 2 byte DialectIndex. */ 561 inc_rfc1001_len(work->response_buf, 4); 562 neg_rsp->hdr.Status.CifsError = STATUS_SUCCESS; 563 564 neg_rsp->hdr.WordCount = 1; 565 neg_rsp->DialectIndex = cpu_to_le16(work->conn->dialect); 566 neg_rsp->ByteCount = 0; 567 return 0; 568 } 569 570 int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command) 571 { 572 struct ksmbd_conn *conn = work->conn; 573 int ret; 574 575 conn->dialect = 576 ksmbd_negotiate_smb_dialect(work->request_buf); 577 ksmbd_debug(SMB, "conn->dialect 0x%x\n", conn->dialect); 578 579 if (command == SMB2_NEGOTIATE_HE) { 580 ret = smb2_handle_negotiate(work); 581 return ret; 582 } 583 584 if (command == SMB_COM_NEGOTIATE) { 585 if (__smb2_negotiate(conn)) { 586 init_smb3_11_server(conn); 587 init_smb2_neg_rsp(work); 588 ksmbd_debug(SMB, "Upgrade to SMB2 negotiation\n"); 589 return 0; 590 } 591 return smb_handle_negotiate(work); 592 } 593 594 pr_err("Unknown SMB negotiation command: %u\n", command); 595 return -EINVAL; 596 } 597 598 enum SHARED_MODE_ERRORS { 599 SHARE_DELETE_ERROR, 600 SHARE_READ_ERROR, 601 SHARE_WRITE_ERROR, 602 FILE_READ_ERROR, 603 FILE_WRITE_ERROR, 604 FILE_DELETE_ERROR, 605 }; 606 607 static const char * const shared_mode_errors[] = { 608 "Current access mode does not permit SHARE_DELETE", 609 "Current access mode does not permit SHARE_READ", 610 "Current access mode does not permit SHARE_WRITE", 611 "Desired access mode does not permit FILE_READ", 612 "Desired access mode does not permit FILE_WRITE", 613 "Desired access mode does not permit FILE_DELETE", 614 }; 615 616 static void smb_shared_mode_error(int error, struct ksmbd_file *prev_fp, 617 struct ksmbd_file *curr_fp) 618 { 619 ksmbd_debug(SMB, "%s\n", shared_mode_errors[error]); 620 ksmbd_debug(SMB, "Current mode: 0x%x Desired mode: 0x%x\n", 621 prev_fp->saccess, curr_fp->daccess); 622 } 623 624 int ksmbd_smb_check_shared_mode(struct file *filp, struct ksmbd_file *curr_fp) 625 { 626 int rc = 0; 627 struct ksmbd_file *prev_fp; 628 629 /* 630 * Lookup fp in master fp list, and check desired access and 631 * shared mode between previous open and current open. 632 */ 633 read_lock(&curr_fp->f_ci->m_lock); 634 list_for_each_entry(prev_fp, &curr_fp->f_ci->m_fp_list, node) { 635 if (file_inode(filp) != file_inode(prev_fp->filp)) 636 continue; 637 638 if (filp == prev_fp->filp) 639 continue; 640 641 if (ksmbd_stream_fd(prev_fp) && ksmbd_stream_fd(curr_fp)) 642 if (strcmp(prev_fp->stream.name, curr_fp->stream.name)) 643 continue; 644 645 if (prev_fp->attrib_only != curr_fp->attrib_only) 646 continue; 647 648 if (!(prev_fp->saccess & FILE_SHARE_DELETE_LE) && 649 curr_fp->daccess & FILE_DELETE_LE) { 650 smb_shared_mode_error(SHARE_DELETE_ERROR, 651 prev_fp, 652 curr_fp); 653 rc = -EPERM; 654 break; 655 } 656 657 /* 658 * Only check FILE_SHARE_DELETE if stream opened and 659 * normal file opened. 660 */ 661 if (ksmbd_stream_fd(prev_fp) && !ksmbd_stream_fd(curr_fp)) 662 continue; 663 664 if (!(prev_fp->saccess & FILE_SHARE_READ_LE) && 665 curr_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE)) { 666 smb_shared_mode_error(SHARE_READ_ERROR, 667 prev_fp, 668 curr_fp); 669 rc = -EPERM; 670 break; 671 } 672 673 if (!(prev_fp->saccess & FILE_SHARE_WRITE_LE) && 674 curr_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE)) { 675 smb_shared_mode_error(SHARE_WRITE_ERROR, 676 prev_fp, 677 curr_fp); 678 rc = -EPERM; 679 break; 680 } 681 682 if (prev_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE) && 683 !(curr_fp->saccess & FILE_SHARE_READ_LE)) { 684 smb_shared_mode_error(FILE_READ_ERROR, 685 prev_fp, 686 curr_fp); 687 rc = -EPERM; 688 break; 689 } 690 691 if (prev_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE) && 692 !(curr_fp->saccess & FILE_SHARE_WRITE_LE)) { 693 smb_shared_mode_error(FILE_WRITE_ERROR, 694 prev_fp, 695 curr_fp); 696 rc = -EPERM; 697 break; 698 } 699 700 if (prev_fp->daccess & FILE_DELETE_LE && 701 !(curr_fp->saccess & FILE_SHARE_DELETE_LE)) { 702 smb_shared_mode_error(FILE_DELETE_ERROR, 703 prev_fp, 704 curr_fp); 705 rc = -EPERM; 706 break; 707 } 708 } 709 read_unlock(&curr_fp->f_ci->m_lock); 710 711 return rc; 712 } 713 714 bool is_asterisk(char *p) 715 { 716 return p && p[0] == '*'; 717 } 718 719 int ksmbd_override_fsids(struct ksmbd_work *work) 720 { 721 struct ksmbd_session *sess = work->sess; 722 struct ksmbd_share_config *share = work->tcon->share_conf; 723 struct cred *cred; 724 struct group_info *gi; 725 unsigned int uid; 726 unsigned int gid; 727 728 uid = user_uid(sess->user); 729 gid = user_gid(sess->user); 730 if (share->force_uid != KSMBD_SHARE_INVALID_UID) 731 uid = share->force_uid; 732 if (share->force_gid != KSMBD_SHARE_INVALID_GID) 733 gid = share->force_gid; 734 735 cred = prepare_kernel_cred(&init_task); 736 if (!cred) 737 return -ENOMEM; 738 739 cred->fsuid = make_kuid(&init_user_ns, uid); 740 cred->fsgid = make_kgid(&init_user_ns, gid); 741 742 gi = groups_alloc(0); 743 if (!gi) { 744 abort_creds(cred); 745 return -ENOMEM; 746 } 747 set_groups(cred, gi); 748 put_group_info(gi); 749 750 if (!uid_eq(cred->fsuid, GLOBAL_ROOT_UID)) 751 cred->cap_effective = cap_drop_fs_set(cred->cap_effective); 752 753 WARN_ON(work->saved_cred); 754 work->saved_cred = override_creds(cred); 755 if (!work->saved_cred) { 756 abort_creds(cred); 757 return -EINVAL; 758 } 759 return 0; 760 } 761 762 void ksmbd_revert_fsids(struct ksmbd_work *work) 763 { 764 const struct cred *cred; 765 766 WARN_ON(!work->saved_cred); 767 768 cred = current_cred(); 769 revert_creds(work->saved_cred); 770 put_cred(cred); 771 work->saved_cred = NULL; 772 } 773 774 __le32 smb_map_generic_desired_access(__le32 daccess) 775 { 776 if (daccess & FILE_GENERIC_READ_LE) { 777 daccess |= cpu_to_le32(GENERIC_READ_FLAGS); 778 daccess &= ~FILE_GENERIC_READ_LE; 779 } 780 781 if (daccess & FILE_GENERIC_WRITE_LE) { 782 daccess |= cpu_to_le32(GENERIC_WRITE_FLAGS); 783 daccess &= ~FILE_GENERIC_WRITE_LE; 784 } 785 786 if (daccess & FILE_GENERIC_EXECUTE_LE) { 787 daccess |= cpu_to_le32(GENERIC_EXECUTE_FLAGS); 788 daccess &= ~FILE_GENERIC_EXECUTE_LE; 789 } 790 791 if (daccess & FILE_GENERIC_ALL_LE) { 792 daccess |= cpu_to_le32(GENERIC_ALL_FLAGS); 793 daccess &= ~FILE_GENERIC_ALL_LE; 794 } 795 796 return daccess; 797 } 798