1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * 4 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved. 5 * 6 */ 7 8 #include <linux/fs.h> 9 10 #include "debug.h" 11 #include "ntfs.h" 12 #include "ntfs_fs.h" 13 14 static inline int compare_attr(const struct ATTRIB *left, enum ATTR_TYPE type, 15 const __le16 *name, u8 name_len, 16 const u16 *upcase) 17 { 18 /* First, compare the type codes. */ 19 int diff = le32_to_cpu(left->type) - le32_to_cpu(type); 20 21 if (diff) 22 return diff; 23 24 /* They have the same type code, so we have to compare the names. */ 25 return ntfs_cmp_names(attr_name(left), left->name_len, name, name_len, 26 upcase, true); 27 } 28 29 /* 30 * mi_new_attt_id 31 * 32 * Return: Unused attribute id that is less than mrec->next_attr_id. 33 */ 34 static __le16 mi_new_attt_id(struct mft_inode *mi) 35 { 36 u16 free_id, max_id, t16; 37 struct MFT_REC *rec = mi->mrec; 38 struct ATTRIB *attr; 39 __le16 id; 40 41 id = rec->next_attr_id; 42 free_id = le16_to_cpu(id); 43 if (free_id < 0x7FFF) { 44 rec->next_attr_id = cpu_to_le16(free_id + 1); 45 return id; 46 } 47 48 /* One record can store up to 1024/24 ~= 42 attributes. */ 49 free_id = 0; 50 max_id = 0; 51 52 attr = NULL; 53 54 for (;;) { 55 attr = mi_enum_attr(mi, attr); 56 if (!attr) { 57 rec->next_attr_id = cpu_to_le16(max_id + 1); 58 mi->dirty = true; 59 return cpu_to_le16(free_id); 60 } 61 62 t16 = le16_to_cpu(attr->id); 63 if (t16 == free_id) { 64 free_id += 1; 65 attr = NULL; 66 } else if (max_id < t16) 67 max_id = t16; 68 } 69 } 70 71 int mi_get(struct ntfs_sb_info *sbi, CLST rno, struct mft_inode **mi) 72 { 73 int err; 74 struct mft_inode *m = kzalloc(sizeof(struct mft_inode), GFP_NOFS); 75 76 if (!m) 77 return -ENOMEM; 78 79 err = mi_init(m, sbi, rno); 80 if (err) { 81 kfree(m); 82 return err; 83 } 84 85 err = mi_read(m, false); 86 if (err) { 87 mi_put(m); 88 return err; 89 } 90 91 *mi = m; 92 return 0; 93 } 94 95 void mi_put(struct mft_inode *mi) 96 { 97 mi_clear(mi); 98 kfree(mi); 99 } 100 101 int mi_init(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno) 102 { 103 mi->sbi = sbi; 104 mi->rno = rno; 105 mi->mrec = kmalloc(sbi->record_size, GFP_NOFS); 106 if (!mi->mrec) 107 return -ENOMEM; 108 109 return 0; 110 } 111 112 /* 113 * mi_read - Read MFT data. 114 */ 115 int mi_read(struct mft_inode *mi, bool is_mft) 116 { 117 int err; 118 struct MFT_REC *rec = mi->mrec; 119 struct ntfs_sb_info *sbi = mi->sbi; 120 u32 bpr = sbi->record_size; 121 u64 vbo = (u64)mi->rno << sbi->record_bits; 122 struct ntfs_inode *mft_ni = sbi->mft.ni; 123 struct runs_tree *run = mft_ni ? &mft_ni->file.run : NULL; 124 struct rw_semaphore *rw_lock = NULL; 125 126 if (is_mounted(sbi)) { 127 if (!is_mft && mft_ni) { 128 rw_lock = &mft_ni->file.run_lock; 129 down_read(rw_lock); 130 } 131 } 132 133 err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb); 134 if (rw_lock) 135 up_read(rw_lock); 136 if (!err) 137 goto ok; 138 139 if (err == -E_NTFS_FIXUP) { 140 mi->dirty = true; 141 goto ok; 142 } 143 144 if (err != -ENOENT) 145 goto out; 146 147 if (rw_lock) { 148 ni_lock(mft_ni); 149 down_write(rw_lock); 150 } 151 err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, run, 152 vbo >> sbi->cluster_bits); 153 if (rw_lock) { 154 up_write(rw_lock); 155 ni_unlock(mft_ni); 156 } 157 if (err) 158 goto out; 159 160 if (rw_lock) 161 down_read(rw_lock); 162 err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb); 163 if (rw_lock) 164 up_read(rw_lock); 165 166 if (err == -E_NTFS_FIXUP) { 167 mi->dirty = true; 168 goto ok; 169 } 170 if (err) 171 goto out; 172 173 ok: 174 /* Check field 'total' only here. */ 175 if (le32_to_cpu(rec->total) != bpr) { 176 err = -EINVAL; 177 goto out; 178 } 179 180 return 0; 181 182 out: 183 if (err == -E_NTFS_CORRUPT) { 184 ntfs_err(sbi->sb, "mft corrupted"); 185 ntfs_set_state(sbi, NTFS_DIRTY_ERROR); 186 err = -EINVAL; 187 } 188 189 return err; 190 } 191 192 /* 193 * mi_enum_attr - start/continue attributes enumeration in record. 194 * 195 * NOTE: mi->mrec - memory of size sbi->record_size 196 * here we sure that mi->mrec->total == sbi->record_size (see mi_read) 197 */ 198 struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr) 199 { 200 const struct MFT_REC *rec = mi->mrec; 201 u32 used = le32_to_cpu(rec->used); 202 u32 t32, off, asize, prev_type; 203 u16 t16; 204 u64 data_size, alloc_size, tot_size; 205 206 if (!attr) { 207 u32 total = le32_to_cpu(rec->total); 208 209 off = le16_to_cpu(rec->attr_off); 210 211 if (used > total) 212 return NULL; 213 214 if (off >= used || off < MFTRECORD_FIXUP_OFFSET_1 || 215 !IS_ALIGNED(off, 4)) { 216 return NULL; 217 } 218 219 /* Skip non-resident records. */ 220 if (!is_rec_inuse(rec)) 221 return NULL; 222 223 prev_type = 0; 224 attr = Add2Ptr(rec, off); 225 } else { 226 /* 227 * We don't need to check previous attr here. There is 228 * a bounds checking in the previous round. 229 */ 230 off = PtrOffset(rec, attr); 231 232 asize = le32_to_cpu(attr->size); 233 234 prev_type = le32_to_cpu(attr->type); 235 attr = Add2Ptr(attr, asize); 236 off += asize; 237 } 238 239 /* Can we use the first field (attr->type). */ 240 /* NOTE: this code also checks attr->size availability. */ 241 if (off + 8 > used) { 242 static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8); 243 return NULL; 244 } 245 246 if (attr->type == ATTR_END) { 247 /* End of enumeration. */ 248 return NULL; 249 } 250 251 /* 0x100 is last known attribute for now. */ 252 t32 = le32_to_cpu(attr->type); 253 if (!t32 || (t32 & 0xf) || (t32 > 0x100)) 254 return NULL; 255 256 /* attributes in record must be ordered by type */ 257 if (t32 < prev_type) 258 return NULL; 259 260 asize = le32_to_cpu(attr->size); 261 262 /* Check overflow and boundary. */ 263 if (off + asize < off || off + asize > used) 264 return NULL; 265 266 /* Check size of attribute. */ 267 if (!attr->non_res) { 268 /* Check resident fields. */ 269 if (asize < SIZEOF_RESIDENT) 270 return NULL; 271 272 t16 = le16_to_cpu(attr->res.data_off); 273 if (t16 > asize) 274 return NULL; 275 276 if (le32_to_cpu(attr->res.data_size) > asize - t16) 277 return NULL; 278 279 t32 = sizeof(short) * attr->name_len; 280 if (t32 && le16_to_cpu(attr->name_off) + t32 > t16) 281 return NULL; 282 283 return attr; 284 } 285 286 /* Check nonresident fields. */ 287 if (attr->non_res != 1) 288 return NULL; 289 290 /* Can we use memory including attr->nres.valid_size? */ 291 if (asize < SIZEOF_NONRESIDENT) 292 return NULL; 293 294 t16 = le16_to_cpu(attr->nres.run_off); 295 if (t16 > asize) 296 return NULL; 297 298 t32 = sizeof(short) * attr->name_len; 299 if (t32 && le16_to_cpu(attr->name_off) + t32 > t16) 300 return NULL; 301 302 /* Check start/end vcn. */ 303 if (le64_to_cpu(attr->nres.svcn) > le64_to_cpu(attr->nres.evcn) + 1) 304 return NULL; 305 306 data_size = le64_to_cpu(attr->nres.data_size); 307 if (le64_to_cpu(attr->nres.valid_size) > data_size) 308 return NULL; 309 310 alloc_size = le64_to_cpu(attr->nres.alloc_size); 311 if (data_size > alloc_size) 312 return NULL; 313 314 t32 = mi->sbi->cluster_mask; 315 if (alloc_size & t32) 316 return NULL; 317 318 if (!attr->nres.svcn && is_attr_ext(attr)) { 319 /* First segment of sparse/compressed attribute */ 320 /* Can we use memory including attr->nres.total_size? */ 321 if (asize < SIZEOF_NONRESIDENT_EX) 322 return NULL; 323 324 tot_size = le64_to_cpu(attr->nres.total_size); 325 if (tot_size & t32) 326 return NULL; 327 328 if (tot_size > alloc_size) 329 return NULL; 330 } else { 331 if (attr->nres.c_unit) 332 return NULL; 333 334 if (alloc_size > mi->sbi->volume.size) 335 return NULL; 336 } 337 338 return attr; 339 } 340 341 /* 342 * mi_find_attr - Find the attribute by type and name and id. 343 */ 344 struct ATTRIB *mi_find_attr(struct mft_inode *mi, struct ATTRIB *attr, 345 enum ATTR_TYPE type, const __le16 *name, 346 u8 name_len, const __le16 *id) 347 { 348 u32 type_in = le32_to_cpu(type); 349 u32 atype; 350 351 next_attr: 352 attr = mi_enum_attr(mi, attr); 353 if (!attr) 354 return NULL; 355 356 atype = le32_to_cpu(attr->type); 357 if (atype > type_in) 358 return NULL; 359 360 if (atype < type_in) 361 goto next_attr; 362 363 if (attr->name_len != name_len) 364 goto next_attr; 365 366 if (name_len && memcmp(attr_name(attr), name, name_len * sizeof(short))) 367 goto next_attr; 368 369 if (id && *id != attr->id) 370 goto next_attr; 371 372 return attr; 373 } 374 375 int mi_write(struct mft_inode *mi, int wait) 376 { 377 struct MFT_REC *rec; 378 int err; 379 struct ntfs_sb_info *sbi; 380 381 if (!mi->dirty) 382 return 0; 383 384 sbi = mi->sbi; 385 rec = mi->mrec; 386 387 err = ntfs_write_bh(sbi, &rec->rhdr, &mi->nb, wait); 388 if (err) 389 return err; 390 391 if (mi->rno < sbi->mft.recs_mirr) 392 sbi->flags |= NTFS_FLAGS_MFTMIRR; 393 394 mi->dirty = false; 395 396 return 0; 397 } 398 399 int mi_format_new(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno, 400 __le16 flags, bool is_mft) 401 { 402 int err; 403 u16 seq = 1; 404 struct MFT_REC *rec; 405 u64 vbo = (u64)rno << sbi->record_bits; 406 407 err = mi_init(mi, sbi, rno); 408 if (err) 409 return err; 410 411 rec = mi->mrec; 412 413 if (rno == MFT_REC_MFT) { 414 ; 415 } else if (rno < MFT_REC_FREE) { 416 seq = rno; 417 } else if (rno >= sbi->mft.used) { 418 ; 419 } else if (mi_read(mi, is_mft)) { 420 ; 421 } else if (rec->rhdr.sign == NTFS_FILE_SIGNATURE) { 422 /* Record is reused. Update its sequence number. */ 423 seq = le16_to_cpu(rec->seq) + 1; 424 if (!seq) 425 seq = 1; 426 } 427 428 memcpy(rec, sbi->new_rec, sbi->record_size); 429 430 rec->seq = cpu_to_le16(seq); 431 rec->flags = RECORD_FLAG_IN_USE | flags; 432 if (MFTRECORD_FIXUP_OFFSET == MFTRECORD_FIXUP_OFFSET_3) 433 rec->mft_record = cpu_to_le32(rno); 434 435 mi->dirty = true; 436 437 if (!mi->nb.nbufs) { 438 struct ntfs_inode *ni = sbi->mft.ni; 439 bool lock = false; 440 441 if (is_mounted(sbi) && !is_mft) { 442 down_read(&ni->file.run_lock); 443 lock = true; 444 } 445 446 err = ntfs_get_bh(sbi, &ni->file.run, vbo, sbi->record_size, 447 &mi->nb); 448 if (lock) 449 up_read(&ni->file.run_lock); 450 } 451 452 return err; 453 } 454 455 /* 456 * mi_insert_attr - Reserve space for new attribute. 457 * 458 * Return: Not full constructed attribute or NULL if not possible to create. 459 */ 460 struct ATTRIB *mi_insert_attr(struct mft_inode *mi, enum ATTR_TYPE type, 461 const __le16 *name, u8 name_len, u32 asize, 462 u16 name_off) 463 { 464 size_t tail; 465 struct ATTRIB *attr; 466 __le16 id; 467 struct MFT_REC *rec = mi->mrec; 468 struct ntfs_sb_info *sbi = mi->sbi; 469 u32 used = le32_to_cpu(rec->used); 470 const u16 *upcase = sbi->upcase; 471 472 /* Can we insert mi attribute? */ 473 if (used + asize > sbi->record_size) 474 return NULL; 475 476 /* 477 * Scan through the list of attributes to find the point 478 * at which we should insert it. 479 */ 480 attr = NULL; 481 while ((attr = mi_enum_attr(mi, attr))) { 482 int diff = compare_attr(attr, type, name, name_len, upcase); 483 484 if (diff < 0) 485 continue; 486 487 if (!diff && !is_attr_indexed(attr)) 488 return NULL; 489 break; 490 } 491 492 if (!attr) { 493 /* Append. */ 494 tail = 8; 495 attr = Add2Ptr(rec, used - 8); 496 } else { 497 /* Insert before 'attr'. */ 498 tail = used - PtrOffset(rec, attr); 499 } 500 501 id = mi_new_attt_id(mi); 502 503 memmove(Add2Ptr(attr, asize), attr, tail); 504 memset(attr, 0, asize); 505 506 attr->type = type; 507 attr->size = cpu_to_le32(asize); 508 attr->name_len = name_len; 509 attr->name_off = cpu_to_le16(name_off); 510 attr->id = id; 511 512 memmove(Add2Ptr(attr, name_off), name, name_len * sizeof(short)); 513 rec->used = cpu_to_le32(used + asize); 514 515 mi->dirty = true; 516 517 return attr; 518 } 519 520 /* 521 * mi_remove_attr - Remove the attribute from record. 522 * 523 * NOTE: The source attr will point to next attribute. 524 */ 525 bool mi_remove_attr(struct ntfs_inode *ni, struct mft_inode *mi, 526 struct ATTRIB *attr) 527 { 528 struct MFT_REC *rec = mi->mrec; 529 u32 aoff = PtrOffset(rec, attr); 530 u32 used = le32_to_cpu(rec->used); 531 u32 asize = le32_to_cpu(attr->size); 532 533 if (aoff + asize > used) 534 return false; 535 536 if (ni && is_attr_indexed(attr) && attr->type == ATTR_NAME) { 537 u16 links = le16_to_cpu(ni->mi.mrec->hard_links); 538 if (!links) { 539 /* minor error. Not critical. */ 540 } else { 541 ni->mi.mrec->hard_links = cpu_to_le16(links - 1); 542 ni->mi.dirty = true; 543 } 544 } 545 546 used -= asize; 547 memmove(attr, Add2Ptr(attr, asize), used - aoff); 548 rec->used = cpu_to_le32(used); 549 mi->dirty = true; 550 551 return true; 552 } 553 554 /* bytes = "new attribute size" - "old attribute size" */ 555 bool mi_resize_attr(struct mft_inode *mi, struct ATTRIB *attr, int bytes) 556 { 557 struct MFT_REC *rec = mi->mrec; 558 u32 aoff = PtrOffset(rec, attr); 559 u32 total, used = le32_to_cpu(rec->used); 560 u32 nsize, asize = le32_to_cpu(attr->size); 561 u32 rsize = le32_to_cpu(attr->res.data_size); 562 int tail = (int)(used - aoff - asize); 563 int dsize; 564 char *next; 565 566 if (tail < 0 || aoff >= used) 567 return false; 568 569 if (!bytes) 570 return true; 571 572 total = le32_to_cpu(rec->total); 573 next = Add2Ptr(attr, asize); 574 575 if (bytes > 0) { 576 dsize = ALIGN(bytes, 8); 577 if (used + dsize > total) 578 return false; 579 nsize = asize + dsize; 580 /* Move tail */ 581 memmove(next + dsize, next, tail); 582 memset(next, 0, dsize); 583 used += dsize; 584 rsize += dsize; 585 } else { 586 dsize = ALIGN(-bytes, 8); 587 if (dsize > asize) 588 return false; 589 nsize = asize - dsize; 590 memmove(next - dsize, next, tail); 591 used -= dsize; 592 rsize -= dsize; 593 } 594 595 rec->used = cpu_to_le32(used); 596 attr->size = cpu_to_le32(nsize); 597 if (!attr->non_res) 598 attr->res.data_size = cpu_to_le32(rsize); 599 mi->dirty = true; 600 601 return true; 602 } 603 604 /* 605 * Pack runs in MFT record. 606 * If failed record is not changed. 607 */ 608 int mi_pack_runs(struct mft_inode *mi, struct ATTRIB *attr, 609 struct runs_tree *run, CLST len) 610 { 611 int err = 0; 612 struct ntfs_sb_info *sbi = mi->sbi; 613 u32 new_run_size; 614 CLST plen; 615 struct MFT_REC *rec = mi->mrec; 616 CLST svcn = le64_to_cpu(attr->nres.svcn); 617 u32 used = le32_to_cpu(rec->used); 618 u32 aoff = PtrOffset(rec, attr); 619 u32 asize = le32_to_cpu(attr->size); 620 char *next = Add2Ptr(attr, asize); 621 u16 run_off = le16_to_cpu(attr->nres.run_off); 622 u32 run_size = asize - run_off; 623 u32 tail = used - aoff - asize; 624 u32 dsize = sbi->record_size - used; 625 626 /* Make a maximum gap in current record. */ 627 memmove(next + dsize, next, tail); 628 629 /* Pack as much as possible. */ 630 err = run_pack(run, svcn, len, Add2Ptr(attr, run_off), run_size + dsize, 631 &plen); 632 if (err < 0) { 633 memmove(next, next + dsize, tail); 634 return err; 635 } 636 637 new_run_size = ALIGN(err, 8); 638 639 memmove(next + new_run_size - run_size, next + dsize, tail); 640 641 attr->size = cpu_to_le32(asize + new_run_size - run_size); 642 attr->nres.evcn = cpu_to_le64(svcn + plen - 1); 643 rec->used = cpu_to_le32(used + new_run_size - run_size); 644 mi->dirty = true; 645 646 return 0; 647 } 648