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