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author | Qu Wenruo <quwenruo.btrfs@gmx.com> | 2017-08-23 16:57:58 +0900 |
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committer | David Sterba <dsterba@suse.com> | 2017-10-30 12:27:58 +0100 |
commit | 40c3c40947324d9f40bf47830c92c59a9bbadf4a (patch) | |
tree | 6d65f18cee5baf66afc7bd6b122c0b9cdc72ea94 /fs/btrfs/disk-io.c | |
parent | 7f43d4affb2a254d421ab20b0cf65ac2569909fb (diff) | |
download | linux-40c3c40947324d9f40bf47830c92c59a9bbadf4a.tar.bz2 |
btrfs: Add sanity check for EXTENT_DATA when reading out leaf
Add extra checks for item with EXTENT_DATA type. This checks the
following thing:
0) Key offset
All key offsets must be aligned to sectorsize.
Inline extent must have 0 for key offset.
1) Item size
Uncompressed inline file extent size must match item size.
(Compressed inline file extent has no information about its on-disk size.)
Regular/preallocated file extent size must be a fixed value.
2) Every member of regular file extent item
Including alignment for bytenr and offset, possible value for
compression/encryption/type.
3) Type/compression/encode must be one of the valid values.
This should be the most comprehensive and strict check in the context
of btrfs_item for EXTENT_DATA.
Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ switch to BTRFS_FILE_EXTENT_TYPES, similar to what
BTRFS_COMPRESS_TYPES does ]
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/disk-io.c')
-rw-r--r-- | fs/btrfs/disk-io.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index d1770b3e0385..b863d41f7d0a 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -549,6 +549,100 @@ static int check_tree_block_fsid(struct btrfs_fs_info *fs_info, btrfs_header_level(eb) == 0 ? "leaf" : "node", \ reason, btrfs_header_bytenr(eb), root->objectid, slot) +static int check_extent_data_item(struct btrfs_root *root, + struct extent_buffer *leaf, + struct btrfs_key *key, int slot) +{ + struct btrfs_file_extent_item *fi; + u32 sectorsize = root->fs_info->sectorsize; + u32 item_size = btrfs_item_size_nr(leaf, slot); + + if (!IS_ALIGNED(key->offset, sectorsize)) { + CORRUPT("unaligned key offset for file extent", + leaf, root, slot); + return -EUCLEAN; + } + + fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); + + if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) { + CORRUPT("invalid file extent type", leaf, root, slot); + return -EUCLEAN; + } + + /* + * Support for new compression/encrption must introduce incompat flag, + * and must be caught in open_ctree(). + */ + if (btrfs_file_extent_compression(leaf, fi) > BTRFS_COMPRESS_TYPES) { + CORRUPT("invalid file extent compression", leaf, root, slot); + return -EUCLEAN; + } + if (btrfs_file_extent_encryption(leaf, fi)) { + CORRUPT("invalid file extent encryption", leaf, root, slot); + return -EUCLEAN; + } + if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) { + /* Inline extent must have 0 as key offset */ + if (key->offset) { + CORRUPT("inline extent has non-zero key offset", + leaf, root, slot); + return -EUCLEAN; + } + + /* Compressed inline extent has no on-disk size, skip it */ + if (btrfs_file_extent_compression(leaf, fi) != + BTRFS_COMPRESS_NONE) + return 0; + + /* Uncompressed inline extent size must match item size */ + if (item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START + + btrfs_file_extent_ram_bytes(leaf, fi)) { + CORRUPT("plaintext inline extent has invalid size", + leaf, root, slot); + return -EUCLEAN; + } + return 0; + } + + /* Regular or preallocated extent has fixed item size */ + if (item_size != sizeof(*fi)) { + CORRUPT( + "regluar or preallocated extent data item size is invalid", + leaf, root, slot); + return -EUCLEAN; + } + if (!IS_ALIGNED(btrfs_file_extent_ram_bytes(leaf, fi), sectorsize) || + !IS_ALIGNED(btrfs_file_extent_disk_bytenr(leaf, fi), sectorsize) || + !IS_ALIGNED(btrfs_file_extent_disk_num_bytes(leaf, fi), sectorsize) || + !IS_ALIGNED(btrfs_file_extent_offset(leaf, fi), sectorsize) || + !IS_ALIGNED(btrfs_file_extent_num_bytes(leaf, fi), sectorsize)) { + CORRUPT( + "regular or preallocated extent data item has unaligned value", + leaf, root, slot); + return -EUCLEAN; + } + + return 0; +} + +/* + * Common point to switch the item-specific validation. + */ +static int check_leaf_item(struct btrfs_root *root, + struct extent_buffer *leaf, + struct btrfs_key *key, int slot) +{ + int ret = 0; + + switch (key->type) { + case BTRFS_EXTENT_DATA_KEY: + ret = check_extent_data_item(root, leaf, key, slot); + break; + } + return ret; +} + static noinline int check_leaf(struct btrfs_root *root, struct extent_buffer *leaf) { @@ -605,9 +699,13 @@ static noinline int check_leaf(struct btrfs_root *root, * 1) key order * 2) item offset and size * No overlap, no hole, all inside the leaf. + * 3) item content + * If possible, do comprehensive sanity check. + * NOTE: All checks must only rely on the item data itself. */ for (slot = 0; slot < nritems; slot++) { u32 item_end_expected; + int ret; btrfs_item_key_to_cpu(leaf, &key, slot); @@ -650,6 +748,11 @@ static noinline int check_leaf(struct btrfs_root *root, return -EUCLEAN; } + /* Check if the item size and content meet other criteria */ + ret = check_leaf_item(root, leaf, &key, slot); + if (ret < 0) + return ret; + prev_key.objectid = key.objectid; prev_key.type = key.type; prev_key.offset = key.offset; |