2 * Copyright (C) Qu Wenruo 2017. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program.
18 * The module is used to catch unexpected/corrupted tree block data.
19 * Such behavior can be caused either by a fuzzed image or bugs.
21 * The objective is to do leaf/node validation checks when tree block is read
22 * from disk, and check *every* possible member, so other code won't
23 * need to checking them again.
25 * Due to the potential and unwanted damage, every checker needs to be
26 * carefully reviewed otherwise so it does not prevent mount of valid images.
30 #include "tree-checker.h"
32 #include "compression.h"
35 * Error message should follow the following format:
36 * corrupt <type>: <identifier>, <reason>[, <bad_value>]
39 * @identifier: the necessary info to locate the leaf/node.
40 * It's recommened to decode key.objecitd/offset if it's
42 * @reason: describe the error
43 * @bad_value: optional, it's recommened to output bad value and its
44 * expected value (range).
46 * Since comma is used to separate the components, only space is allowed
47 * inside each component.
51 * Append generic "corrupt leaf/node root=%llu block=%llu slot=%d: " to @fmt.
52 * Allows callers to customize the output.
56 static void generic_err(const struct btrfs_fs_info *fs_info,
57 const struct extent_buffer *eb, int slot,
69 "corrupt %s: root=%llu block=%llu slot=%d, %pV",
70 btrfs_header_level(eb) == 0 ? "leaf" : "node",
71 btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot, &vaf);
76 * Customized reporter for extent data item, since its key objectid and
77 * offset has its own meaning.
81 static void file_extent_err(const struct btrfs_fs_info *fs_info,
82 const struct extent_buffer *eb, int slot,
89 btrfs_item_key_to_cpu(eb, &key, slot);
96 "corrupt %s: root=%llu block=%llu slot=%d ino=%llu file_offset=%llu, %pV",
97 btrfs_header_level(eb) == 0 ? "leaf" : "node",
98 btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
99 key.objectid, key.offset, &vaf);
104 * Return 0 if the btrfs_file_extent_##name is aligned to @alignment
107 #define CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, name, alignment) \
109 if (!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment))) \
110 file_extent_err((fs_info), (leaf), (slot), \
111 "invalid %s for file extent, have %llu, should be aligned to %u", \
112 (#name), btrfs_file_extent_##name((leaf), (fi)), \
114 (!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment))); \
117 static int check_extent_data_item(struct btrfs_fs_info *fs_info,
118 struct extent_buffer *leaf,
119 struct btrfs_key *key, int slot)
121 struct btrfs_file_extent_item *fi;
122 u32 sectorsize = fs_info->sectorsize;
123 u32 item_size = btrfs_item_size_nr(leaf, slot);
125 if (!IS_ALIGNED(key->offset, sectorsize)) {
126 file_extent_err(fs_info, leaf, slot,
127 "unaligned file_offset for file extent, have %llu should be aligned to %u",
128 key->offset, sectorsize);
132 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
134 if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) {
135 file_extent_err(fs_info, leaf, slot,
136 "invalid type for file extent, have %u expect range [0, %u]",
137 btrfs_file_extent_type(leaf, fi),
138 BTRFS_FILE_EXTENT_TYPES);
143 * Support for new compression/encrption must introduce incompat flag,
144 * and must be caught in open_ctree().
146 if (btrfs_file_extent_compression(leaf, fi) > BTRFS_COMPRESS_TYPES) {
147 file_extent_err(fs_info, leaf, slot,
148 "invalid compression for file extent, have %u expect range [0, %u]",
149 btrfs_file_extent_compression(leaf, fi),
150 BTRFS_COMPRESS_TYPES);
153 if (btrfs_file_extent_encryption(leaf, fi)) {
154 file_extent_err(fs_info, leaf, slot,
155 "invalid encryption for file extent, have %u expect 0",
156 btrfs_file_extent_encryption(leaf, fi));
159 if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
160 /* Inline extent must have 0 as key offset */
162 file_extent_err(fs_info, leaf, slot,
163 "invalid file_offset for inline file extent, have %llu expect 0",
168 /* Compressed inline extent has no on-disk size, skip it */
169 if (btrfs_file_extent_compression(leaf, fi) !=
173 /* Uncompressed inline extent size must match item size */
174 if (item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START +
175 btrfs_file_extent_ram_bytes(leaf, fi)) {
176 file_extent_err(fs_info, leaf, slot,
177 "invalid ram_bytes for uncompressed inline extent, have %u expect %llu",
178 item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START +
179 btrfs_file_extent_ram_bytes(leaf, fi));
185 /* Regular or preallocated extent has fixed item size */
186 if (item_size != sizeof(*fi)) {
187 file_extent_err(fs_info, leaf, slot,
188 "invalid item size for reg/prealloc file extent, have %u expect %zu",
189 item_size, sizeof(*fi));
192 if (CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, ram_bytes, sectorsize) ||
193 CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, disk_bytenr, sectorsize) ||
194 CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, disk_num_bytes, sectorsize) ||
195 CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, offset, sectorsize) ||
196 CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, num_bytes, sectorsize))
201 static int check_csum_item(struct btrfs_fs_info *fs_info,
202 struct extent_buffer *leaf, struct btrfs_key *key,
205 u32 sectorsize = fs_info->sectorsize;
206 u32 csumsize = btrfs_super_csum_size(fs_info->super_copy);
208 if (key->objectid != BTRFS_EXTENT_CSUM_OBJECTID) {
209 generic_err(fs_info, leaf, slot,
210 "invalid key objectid for csum item, have %llu expect %llu",
211 key->objectid, BTRFS_EXTENT_CSUM_OBJECTID);
214 if (!IS_ALIGNED(key->offset, sectorsize)) {
215 generic_err(fs_info, leaf, slot,
216 "unaligned key offset for csum item, have %llu should be aligned to %u",
217 key->offset, sectorsize);
220 if (!IS_ALIGNED(btrfs_item_size_nr(leaf, slot), csumsize)) {
221 generic_err(fs_info, leaf, slot,
222 "unaligned item size for csum item, have %u should be aligned to %u",
223 btrfs_item_size_nr(leaf, slot), csumsize);
230 * Customized reported for dir_item, only important new info is key->objectid,
231 * which represents inode number
235 static void dir_item_err(const struct btrfs_fs_info *fs_info,
236 const struct extent_buffer *eb, int slot,
237 const char *fmt, ...)
239 struct btrfs_key key;
240 struct va_format vaf;
243 btrfs_item_key_to_cpu(eb, &key, slot);
250 "corrupt %s: root=%llu block=%llu slot=%d ino=%llu, %pV",
251 btrfs_header_level(eb) == 0 ? "leaf" : "node",
252 btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot,
257 static int check_dir_item(struct btrfs_fs_info *fs_info,
258 struct extent_buffer *leaf,
259 struct btrfs_key *key, int slot)
261 struct btrfs_dir_item *di;
262 u32 item_size = btrfs_item_size_nr(leaf, slot);
265 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
266 while (cur < item_size) {
274 /* header itself should not cross item boundary */
275 if (cur + sizeof(*di) > item_size) {
276 dir_item_err(fs_info, leaf, slot,
277 "dir item header crosses item boundary, have %zu boundary %u",
278 cur + sizeof(*di), item_size);
283 dir_type = btrfs_dir_type(leaf, di);
284 if (dir_type >= BTRFS_FT_MAX) {
285 dir_item_err(fs_info, leaf, slot,
286 "invalid dir item type, have %u expect [0, %u)",
287 dir_type, BTRFS_FT_MAX);
291 if (key->type == BTRFS_XATTR_ITEM_KEY &&
292 dir_type != BTRFS_FT_XATTR) {
293 dir_item_err(fs_info, leaf, slot,
294 "invalid dir item type for XATTR key, have %u expect %u",
295 dir_type, BTRFS_FT_XATTR);
298 if (dir_type == BTRFS_FT_XATTR &&
299 key->type != BTRFS_XATTR_ITEM_KEY) {
300 dir_item_err(fs_info, leaf, slot,
301 "xattr dir type found for non-XATTR key");
304 if (dir_type == BTRFS_FT_XATTR)
305 max_name_len = XATTR_NAME_MAX;
307 max_name_len = BTRFS_NAME_LEN;
309 /* Name/data length check */
310 name_len = btrfs_dir_name_len(leaf, di);
311 data_len = btrfs_dir_data_len(leaf, di);
312 if (name_len > max_name_len) {
313 dir_item_err(fs_info, leaf, slot,
314 "dir item name len too long, have %u max %u",
315 name_len, max_name_len);
318 if (name_len + data_len > BTRFS_MAX_XATTR_SIZE(fs_info)) {
319 dir_item_err(fs_info, leaf, slot,
320 "dir item name and data len too long, have %u max %u",
322 BTRFS_MAX_XATTR_SIZE(fs_info));
326 if (data_len && dir_type != BTRFS_FT_XATTR) {
327 dir_item_err(fs_info, leaf, slot,
328 "dir item with invalid data len, have %u expect 0",
333 total_size = sizeof(*di) + name_len + data_len;
335 /* header and name/data should not cross item boundary */
336 if (cur + total_size > item_size) {
337 dir_item_err(fs_info, leaf, slot,
338 "dir item data crosses item boundary, have %u boundary %u",
339 cur + total_size, item_size);
344 * Special check for XATTR/DIR_ITEM, as key->offset is name
345 * hash, should match its name
347 if (key->type == BTRFS_DIR_ITEM_KEY ||
348 key->type == BTRFS_XATTR_ITEM_KEY) {
349 char namebuf[max(BTRFS_NAME_LEN, XATTR_NAME_MAX)];
351 read_extent_buffer(leaf, namebuf,
352 (unsigned long)(di + 1), name_len);
353 name_hash = btrfs_name_hash(namebuf, name_len);
354 if (key->offset != name_hash) {
355 dir_item_err(fs_info, leaf, slot,
356 "name hash mismatch with key, have 0x%016x expect 0x%016llx",
357 name_hash, key->offset);
362 di = (struct btrfs_dir_item *)((void *)di + total_size);
368 * Common point to switch the item-specific validation.
370 static int check_leaf_item(struct btrfs_fs_info *fs_info,
371 struct extent_buffer *leaf,
372 struct btrfs_key *key, int slot)
377 case BTRFS_EXTENT_DATA_KEY:
378 ret = check_extent_data_item(fs_info, leaf, key, slot);
380 case BTRFS_EXTENT_CSUM_KEY:
381 ret = check_csum_item(fs_info, leaf, key, slot);
383 case BTRFS_DIR_ITEM_KEY:
384 case BTRFS_DIR_INDEX_KEY:
385 case BTRFS_XATTR_ITEM_KEY:
386 ret = check_dir_item(fs_info, leaf, key, slot);
392 static int check_leaf(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf,
393 bool check_item_data)
395 /* No valid key type is 0, so all key should be larger than this key */
396 struct btrfs_key prev_key = {0, 0, 0};
397 struct btrfs_key key;
398 u32 nritems = btrfs_header_nritems(leaf);
402 * Extent buffers from a relocation tree have a owner field that
403 * corresponds to the subvolume tree they are based on. So just from an
404 * extent buffer alone we can not find out what is the id of the
405 * corresponding subvolume tree, so we can not figure out if the extent
406 * buffer corresponds to the root of the relocation tree or not. So
407 * skip this check for relocation trees.
409 if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) {
410 struct btrfs_root *check_root;
412 key.objectid = btrfs_header_owner(leaf);
413 key.type = BTRFS_ROOT_ITEM_KEY;
414 key.offset = (u64)-1;
416 check_root = btrfs_get_fs_root(fs_info, &key, false);
418 * The only reason we also check NULL here is that during
419 * open_ctree() some roots has not yet been set up.
421 if (!IS_ERR_OR_NULL(check_root)) {
422 struct extent_buffer *eb;
424 eb = btrfs_root_node(check_root);
425 /* if leaf is the root, then it's fine */
427 generic_err(fs_info, leaf, 0,
428 "invalid nritems, have %u should not be 0 for non-root leaf",
430 free_extent_buffer(eb);
433 free_extent_buffer(eb);
442 * Check the following things to make sure this is a good leaf, and
443 * leaf users won't need to bother with similar sanity checks:
446 * 2) item offset and size
447 * No overlap, no hole, all inside the leaf.
449 * If possible, do comprehensive sanity check.
450 * NOTE: All checks must only rely on the item data itself.
452 for (slot = 0; slot < nritems; slot++) {
453 u32 item_end_expected;
456 btrfs_item_key_to_cpu(leaf, &key, slot);
458 /* Make sure the keys are in the right order */
459 if (btrfs_comp_cpu_keys(&prev_key, &key) >= 0) {
460 generic_err(fs_info, leaf, slot,
461 "bad key order, prev (%llu %u %llu) current (%llu %u %llu)",
462 prev_key.objectid, prev_key.type,
463 prev_key.offset, key.objectid, key.type,
469 * Make sure the offset and ends are right, remember that the
470 * item data starts at the end of the leaf and grows towards the
474 item_end_expected = BTRFS_LEAF_DATA_SIZE(fs_info);
476 item_end_expected = btrfs_item_offset_nr(leaf,
478 if (btrfs_item_end_nr(leaf, slot) != item_end_expected) {
479 generic_err(fs_info, leaf, slot,
480 "unexpected item end, have %u expect %u",
481 btrfs_item_end_nr(leaf, slot),
487 * Check to make sure that we don't point outside of the leaf,
488 * just in case all the items are consistent to each other, but
489 * all point outside of the leaf.
491 if (btrfs_item_end_nr(leaf, slot) >
492 BTRFS_LEAF_DATA_SIZE(fs_info)) {
493 generic_err(fs_info, leaf, slot,
494 "slot end outside of leaf, have %u expect range [0, %u]",
495 btrfs_item_end_nr(leaf, slot),
496 BTRFS_LEAF_DATA_SIZE(fs_info));
500 /* Also check if the item pointer overlaps with btrfs item. */
501 if (btrfs_item_nr_offset(slot) + sizeof(struct btrfs_item) >
502 btrfs_item_ptr_offset(leaf, slot)) {
503 generic_err(fs_info, leaf, slot,
504 "slot overlaps with its data, item end %lu data start %lu",
505 btrfs_item_nr_offset(slot) +
506 sizeof(struct btrfs_item),
507 btrfs_item_ptr_offset(leaf, slot));
511 if (check_item_data) {
513 * Check if the item size and content meet other
516 ret = check_leaf_item(fs_info, leaf, &key, slot);
521 prev_key.objectid = key.objectid;
522 prev_key.type = key.type;
523 prev_key.offset = key.offset;
529 int btrfs_check_leaf_full(struct btrfs_fs_info *fs_info,
530 struct extent_buffer *leaf)
532 return check_leaf(fs_info, leaf, true);
535 int btrfs_check_leaf_relaxed(struct btrfs_fs_info *fs_info,
536 struct extent_buffer *leaf)
538 return check_leaf(fs_info, leaf, false);
541 int btrfs_check_node(struct btrfs_fs_info *fs_info, struct extent_buffer *node)
543 unsigned long nr = btrfs_header_nritems(node);
544 struct btrfs_key key, next_key;
549 if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(fs_info)) {
551 "corrupt node: root=%llu block=%llu, nritems too %s, have %lu expect range [1,%u]",
552 btrfs_header_owner(node), node->start,
553 nr == 0 ? "small" : "large", nr,
554 BTRFS_NODEPTRS_PER_BLOCK(fs_info));
558 for (slot = 0; slot < nr - 1; slot++) {
559 bytenr = btrfs_node_blockptr(node, slot);
560 btrfs_node_key_to_cpu(node, &key, slot);
561 btrfs_node_key_to_cpu(node, &next_key, slot + 1);
564 generic_err(fs_info, node, slot,
565 "invalid NULL node pointer");
569 if (!IS_ALIGNED(bytenr, fs_info->sectorsize)) {
570 generic_err(fs_info, node, slot,
571 "unaligned pointer, have %llu should be aligned to %u",
572 bytenr, fs_info->sectorsize);
577 if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) {
578 generic_err(fs_info, node, slot,
579 "bad key order, current (%llu %u %llu) next (%llu %u %llu)",
580 key.objectid, key.type, key.offset,
581 next_key.objectid, next_key.type,