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, 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 */
mi_find_attr(struct mft_inode * mi,struct ATTRIB * attr,enum ATTR_TYPE type,const __le16 * name,u8 name_len,const __le16 * id)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
mi_write(struct mft_inode * mi,int wait)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
mi_format_new(struct mft_inode * mi,struct ntfs_sb_info * sbi,CLST rno,__le16 flags,bool is_mft)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 */
mi_insert_attr(struct mft_inode * mi,enum ATTR_TYPE type,const __le16 * name,u8 name_len,u32 asize,u16 name_off)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 */
mi_remove_attr(struct ntfs_inode * ni,struct mft_inode * mi,struct ATTRIB * attr)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" */
mi_resize_attr(struct mft_inode * mi,struct ATTRIB * attr,int bytes)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 */
mi_pack_runs(struct mft_inode * mi,struct ATTRIB * attr,struct runs_tree * run,CLST len)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