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
compare_attr(const struct ATTRIB * left,enum ATTR_TYPE type,const __le16 * name,u8 name_len,const u16 * upcase)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 */
mi_new_attt_id(struct ntfs_inode * ni,struct mft_inode * mi)34 static __le16 mi_new_attt_id(struct ntfs_inode *ni, 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(ni, 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
mi_get(struct ntfs_sb_info * sbi,CLST rno,struct mft_inode ** mi)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_obj(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
mi_put(struct mft_inode * mi)95 void mi_put(struct mft_inode *mi)
96 {
97 mi_clear(mi);
98 kfree(mi);
99 }
100
mi_init(struct mft_inode * mi,struct ntfs_sb_info * sbi,CLST rno)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 */
mi_read(struct mft_inode * mi,bool is_mft)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 */
mi_enum_attr(struct ntfs_inode * ni,struct mft_inode * mi,struct ATTRIB * attr)198 struct ATTRIB *mi_enum_attr(struct ntfs_inode *ni, struct mft_inode *mi,
199 struct ATTRIB *attr)
200 {
201 const struct MFT_REC *rec = mi->mrec;
202 u32 used = le32_to_cpu(rec->used);
203 u32 t32, off, asize, prev_type;
204 u16 t16;
205 u64 svcn, evcn, data_size, alloc_size, tot_size;
206
207 if (!attr) {
208 u32 total = le32_to_cpu(rec->total);
209
210 off = le16_to_cpu(rec->attr_off);
211
212 if (used > total)
213 goto out;
214
215 if (off >= used || off < MFTRECORD_FIXUP_OFFSET_1 ||
216 !IS_ALIGNED(off, 8)) {
217 goto out;
218 }
219
220 /* Skip non-resident records. */
221 if (!is_rec_inuse(rec))
222 return NULL;
223
224 prev_type = 0;
225 attr = Add2Ptr(rec, off);
226 } else {
227 /*
228 * We don't need to check previous attr here. There is
229 * a bounds checking in the previous round.
230 */
231 off = PtrOffset(rec, attr);
232
233 asize = le32_to_cpu(attr->size);
234
235 prev_type = le32_to_cpu(attr->type);
236 attr = Add2Ptr(attr, asize);
237 off += asize;
238 }
239
240 /*
241 * Can we use the first fields:
242 * attr->type,
243 * attr->size
244 */
245 if (off + 8 > used) {
246 static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8);
247 goto out;
248 }
249
250 if (attr->type == ATTR_END) {
251 /* End of enumeration. */
252 return NULL;
253 }
254
255 /* 0x100 is last known attribute for now. */
256 t32 = le32_to_cpu(attr->type);
257 if (!t32 || (t32 & 0xf) || (t32 > 0x100))
258 goto out;
259
260 /* attributes in record must be ordered by type */
261 if (t32 < prev_type)
262 goto out;
263
264 asize = le32_to_cpu(attr->size);
265
266 if (!IS_ALIGNED(asize, 8))
267 goto out;
268
269 /* Check overflow and boundary. */
270 if (off + asize < off || off + asize > used)
271 goto out;
272
273 /* Can we use the field attr->non_res. */
274 if (off + 9 > used)
275 goto out;
276
277 /* Check size of attribute. */
278 if (!attr->non_res) {
279 /* Check resident fields. */
280 if (asize < SIZEOF_RESIDENT)
281 goto out;
282
283 t16 = le16_to_cpu(attr->res.data_off);
284 if (t16 > asize)
285 goto out;
286
287 if (le32_to_cpu(attr->res.data_size) > asize - t16)
288 goto out;
289
290 t32 = sizeof(short) * attr->name_len;
291 if (t32 && le16_to_cpu(attr->name_off) + t32 > t16)
292 goto out;
293
294 return attr;
295 }
296
297 /* Check nonresident fields. */
298 if (attr->non_res != 1)
299 goto out;
300
301 /* Can we use memory including attr->nres.valid_size? */
302 if (asize < SIZEOF_NONRESIDENT)
303 goto out;
304
305 t16 = le16_to_cpu(attr->nres.run_off);
306 if (t16 > asize)
307 goto out;
308
309 t32 = sizeof(short) * attr->name_len;
310 if (t32 && le16_to_cpu(attr->name_off) + t32 > t16)
311 goto out;
312
313 /*
314 * Check start/end vcn. svcn == 0 with evcn == -1 (U64_MAX) is the
315 * sentinel for an empty non-resident attribute (no allocated
316 * clusters) and must be accepted: "svcn > evcn + 1" tolerates it,
317 * since "(u64)-1 + 1" is 0 and "0 > 0" is false.
318 *
319 * For a non-empty attribute evcn is a cluster index and must lie
320 * within the volume (sbi->used.bitmap.nbits, set up in
321 * ntfs_init_from_boot() before any caller of mi_enum_attr() runs).
322 * Bounding evcn also prevents a malformed value close to U64_MAX
323 * from slipping through the near-wrap "evcn + 1" upper bound.
324 */
325 svcn = le64_to_cpu(attr->nres.svcn);
326 evcn = le64_to_cpu(attr->nres.evcn);
327 if (svcn > evcn + 1)
328 goto out;
329
330 if (is_attr_ext(attr)) {
331 /* sparsed/compressed attribute. */
332 #ifdef CONFIG_NTFS3_64BIT_CLUSTER
333 /* No limits. */
334 #else
335 /* Check evcn fits into 32 bits. */
336 if (evcn != U64_MAX && evcn >= (1ull << 32))
337 goto out;
338 #endif
339 } else {
340 /* Check out of volume for normal attribute. */
341 if (evcn != U64_MAX && evcn >= mi->sbi->used.bitmap.nbits)
342 goto out;
343 }
344
345 data_size = le64_to_cpu(attr->nres.data_size);
346 if (le64_to_cpu(attr->nres.valid_size) > data_size)
347 goto out;
348
349 alloc_size = le64_to_cpu(attr->nres.alloc_size);
350 if (data_size > alloc_size)
351 goto out;
352
353 t32 = mi->sbi->cluster_mask;
354 if (alloc_size & t32)
355 goto out;
356
357 if (!attr->nres.svcn && is_attr_ext(attr)) {
358 /* First segment of sparse/compressed attribute */
359 /* Can we use memory including attr->nres.total_size? */
360 if (asize < SIZEOF_NONRESIDENT_EX)
361 goto out;
362
363 tot_size = le64_to_cpu(attr->nres.total_size);
364 if (tot_size & t32)
365 goto out;
366
367 if (tot_size > alloc_size)
368 goto out;
369 } else {
370 if (attr->nres.c_unit)
371 goto out;
372
373 if (alloc_size > mi->sbi->volume.size)
374 goto out;
375 }
376
377 return attr;
378
379 out:
380 _ntfs_bad_inode(&ni->vfs_inode);
381 return NULL;
382 }
383
384 /*
385 * mi_find_attr - Find the attribute by type and name and id.
386 */
mi_find_attr(struct ntfs_inode * ni,struct mft_inode * mi,struct ATTRIB * attr,enum ATTR_TYPE type,const __le16 * name,u8 name_len,const __le16 * id)387 struct ATTRIB *mi_find_attr(struct ntfs_inode *ni, struct mft_inode *mi,
388 struct ATTRIB *attr, enum ATTR_TYPE type,
389 const __le16 *name, u8 name_len, const __le16 *id)
390 {
391 u32 type_in = le32_to_cpu(type);
392 u32 atype;
393
394 next_attr:
395 attr = mi_enum_attr(ni, mi, attr);
396 if (!attr)
397 return NULL;
398
399 atype = le32_to_cpu(attr->type);
400 if (atype > type_in)
401 return NULL;
402
403 if (atype < type_in)
404 goto next_attr;
405
406 if (attr->name_len != name_len)
407 goto next_attr;
408
409 if (name_len && memcmp(attr_name(attr), name, name_len * sizeof(short)))
410 goto next_attr;
411
412 if (id && *id != attr->id)
413 goto next_attr;
414
415 return attr;
416 }
417
mi_write(struct mft_inode * mi,int wait)418 int mi_write(struct mft_inode *mi, int wait)
419 {
420 struct MFT_REC *rec;
421 int err;
422 struct ntfs_sb_info *sbi;
423
424 if (!mi->dirty)
425 return 0;
426
427 sbi = mi->sbi;
428 rec = mi->mrec;
429
430 err = ntfs_write_bh(sbi, &rec->rhdr, &mi->nb, wait);
431 if (err)
432 return err;
433
434 if (mi->rno < sbi->mft.recs_mirr)
435 sbi->flags |= NTFS_FLAGS_MFTMIRR;
436
437 mi->dirty = false;
438
439 return 0;
440 }
441
mi_format_new(struct mft_inode * mi,struct ntfs_sb_info * sbi,CLST rno,__le16 flags,bool is_mft)442 int mi_format_new(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno,
443 __le16 flags, bool is_mft)
444 {
445 int err;
446 u16 seq = 1;
447 struct MFT_REC *rec;
448 u64 vbo = (u64)rno << sbi->record_bits;
449
450 err = mi_init(mi, sbi, rno);
451 if (err)
452 return err;
453
454 rec = mi->mrec;
455
456 if (rno == MFT_REC_MFT) {
457 ;
458 } else if (rno < MFT_REC_FREE) {
459 seq = rno;
460 } else if (rno >= sbi->mft.used) {
461 ;
462 } else if (mi_read(mi, is_mft)) {
463 ;
464 } else if (rec->rhdr.sign == NTFS_FILE_SIGNATURE) {
465 /* Record is reused. Update its sequence number. */
466 seq = le16_to_cpu(rec->seq) + 1;
467 if (!seq)
468 seq = 1;
469 }
470
471 memcpy(rec, sbi->new_rec, sbi->record_size);
472
473 rec->seq = cpu_to_le16(seq);
474 rec->flags = RECORD_FLAG_IN_USE | flags;
475 if (MFTRECORD_FIXUP_OFFSET == MFTRECORD_FIXUP_OFFSET_3)
476 rec->mft_record = cpu_to_le32(rno);
477
478 mi->dirty = true;
479
480 if (!mi->nb.nbufs) {
481 struct ntfs_inode *ni = sbi->mft.ni;
482 bool lock = false;
483
484 if (is_mounted(sbi) && !is_mft) {
485 down_read(&ni->file.run_lock);
486 lock = true;
487 }
488
489 err = ntfs_get_bh(sbi, &ni->file.run, vbo, sbi->record_size,
490 &mi->nb);
491 if (lock)
492 up_read(&ni->file.run_lock);
493 }
494
495 return err;
496 }
497
498 /*
499 * mi_insert_attr - Reserve space for new attribute.
500 *
501 * Return: Not full constructed attribute or NULL if not possible to create.
502 */
mi_insert_attr(struct ntfs_inode * ni,struct mft_inode * mi,enum ATTR_TYPE type,const __le16 * name,u8 name_len,u32 asize,u16 name_off)503 struct ATTRIB *mi_insert_attr(struct ntfs_inode *ni, struct mft_inode *mi,
504 enum ATTR_TYPE type, const __le16 *name,
505 u8 name_len, u32 asize, u16 name_off)
506 {
507 size_t tail;
508 struct ATTRIB *attr;
509 __le16 id;
510 struct MFT_REC *rec = mi->mrec;
511 struct ntfs_sb_info *sbi = mi->sbi;
512 u32 used = le32_to_cpu(rec->used);
513 const u16 *upcase = sbi->upcase;
514
515 /* Can we insert mi attribute? */
516 if (used + asize > sbi->record_size)
517 return NULL;
518
519 /*
520 * Scan through the list of attributes to find the point
521 * at which we should insert it.
522 */
523 attr = NULL;
524 while ((attr = mi_enum_attr(ni, mi, attr))) {
525 int diff = compare_attr(attr, type, name, name_len, upcase);
526
527 if (diff < 0)
528 continue;
529
530 if (!diff && !is_attr_indexed(attr))
531 return NULL;
532 break;
533 }
534
535 if (!attr) {
536 /* Append. */
537 tail = 8;
538 attr = Add2Ptr(rec, used - 8);
539 } else {
540 /* Insert before 'attr'. */
541 tail = used - PtrOffset(rec, attr);
542 }
543
544 id = mi_new_attt_id(ni, mi);
545
546 memmove(Add2Ptr(attr, asize), attr, tail);
547 memset(attr, 0, asize);
548
549 attr->type = type;
550 attr->size = cpu_to_le32(asize);
551 attr->name_len = name_len;
552 attr->name_off = cpu_to_le16(name_off);
553 attr->id = id;
554
555 memmove(Add2Ptr(attr, name_off), name, name_len * sizeof(short));
556 rec->used = cpu_to_le32(used + asize);
557
558 mi->dirty = true;
559
560 return attr;
561 }
562
563 /*
564 * mi_remove_attr - Remove the attribute from record.
565 *
566 * NOTE: The source attr will point to next attribute.
567 */
mi_remove_attr(struct ntfs_inode * ni,struct mft_inode * mi,struct ATTRIB * attr)568 bool mi_remove_attr(struct ntfs_inode *ni, struct mft_inode *mi,
569 struct ATTRIB *attr)
570 {
571 struct MFT_REC *rec = mi->mrec;
572 u32 aoff = PtrOffset(rec, attr);
573 u32 used = le32_to_cpu(rec->used);
574 u32 asize = le32_to_cpu(attr->size);
575
576 if (aoff + asize > used)
577 return false;
578
579 if (ni && is_attr_indexed(attr) && attr->type == ATTR_NAME) {
580 u16 links = le16_to_cpu(ni->mi.mrec->hard_links);
581 if (!links) {
582 /* minor error. Not critical. */
583 } else {
584 ni->mi.mrec->hard_links = cpu_to_le16(links - 1);
585 ni->mi.dirty = true;
586 }
587 }
588
589 used -= asize;
590 memmove(attr, Add2Ptr(attr, asize), used - aoff);
591 rec->used = cpu_to_le32(used);
592 mi->dirty = true;
593
594 return true;
595 }
596
597 /* bytes = "new attribute size" - "old attribute size" */
mi_resize_attr(struct mft_inode * mi,struct ATTRIB * attr,int bytes)598 bool mi_resize_attr(struct mft_inode *mi, struct ATTRIB *attr, int bytes)
599 {
600 struct MFT_REC *rec = mi->mrec;
601 u32 aoff = PtrOffset(rec, attr);
602 u32 total, used = le32_to_cpu(rec->used);
603 u32 nsize, asize = le32_to_cpu(attr->size);
604 u32 rsize = le32_to_cpu(attr->res.data_size);
605 int tail = (int)(used - aoff - asize);
606 int dsize;
607 char *next;
608
609 if (tail < 0 || aoff >= used)
610 return false;
611
612 if (!bytes)
613 return true;
614
615 total = le32_to_cpu(rec->total);
616 next = Add2Ptr(attr, asize);
617
618 if (bytes > 0) {
619 dsize = ALIGN(bytes, 8);
620 if (used + dsize > total)
621 return false;
622 nsize = asize + dsize;
623 /* Move tail */
624 memmove(next + dsize, next, tail);
625 memset(next, 0, dsize);
626 used += dsize;
627 rsize += dsize;
628 } else {
629 dsize = ALIGN(-bytes, 8);
630 if (dsize > asize)
631 return false;
632 nsize = asize - dsize;
633 memmove(next - dsize, next, tail);
634 used -= dsize;
635 rsize -= dsize;
636 }
637
638 rec->used = cpu_to_le32(used);
639 attr->size = cpu_to_le32(nsize);
640 if (!attr->non_res)
641 attr->res.data_size = cpu_to_le32(rsize);
642 mi->dirty = true;
643
644 return true;
645 }
646
647 /*
648 * Pack runs in MFT record.
649 * If failed record is not changed.
650 */
mi_pack_runs(struct mft_inode * mi,struct ATTRIB * attr,const struct runs_tree * run,CLST len)651 int mi_pack_runs(struct mft_inode *mi, struct ATTRIB *attr,
652 const struct runs_tree *run, CLST len)
653 {
654 int err = 0;
655 struct ntfs_sb_info *sbi = mi->sbi;
656 u32 new_run_size;
657 CLST plen;
658 struct MFT_REC *rec = mi->mrec;
659 CLST svcn = le64_to_cpu(attr->nres.svcn);
660 u32 used = le32_to_cpu(rec->used);
661 u32 aoff = PtrOffset(rec, attr);
662 u32 asize = le32_to_cpu(attr->size);
663 char *next = Add2Ptr(attr, asize);
664 u16 run_off = le16_to_cpu(attr->nres.run_off);
665 u32 run_size = asize - run_off;
666 u32 tail = used - aoff - asize;
667 u32 dsize = sbi->record_size - used;
668
669 /* Make a maximum gap in current record. */
670 memmove(next + dsize, next, tail);
671
672 /* Pack as much as possible. */
673 err = run_pack(run, svcn, len, Add2Ptr(attr, run_off), run_size + dsize,
674 &plen);
675 if (err < 0) {
676 memmove(next, next + dsize, tail);
677 return err;
678 }
679
680 new_run_size = ALIGN(err, 8);
681
682 memmove(next + new_run_size - run_size, next + dsize, tail);
683
684 attr->size = cpu_to_le32(asize + new_run_size - run_size);
685 attr->nres.evcn = cpu_to_le64(svcn + plen - 1);
686 rec->used = cpu_to_le32(used + new_run_size - run_size);
687 mi->dirty = true;
688
689 return 0;
690 }
691