From: Qu Wenruo wqu@suse.com
[ Upstream commit f6d2a5c263afca84646cf3300dc13061bedbd99e ]
Inspired by btrfs-progs github issue #208, where chunk item in chunk tree has invalid num_stripes (0).
Although that can already be caught by current btrfs_check_chunk_valid(), that function doesn't really check item size as it needs to handle chunk item in super block sys_chunk_array().
This patch will add two extra checks for chunk items in chunk tree:
- Basic chunk item size If the item is smaller than btrfs_chunk (which already contains one stripe), exit right now as reading num_stripes may even go beyond eb boundary.
- Item size check against num_stripes If item size doesn't match with calculated chunk size, then either the item size or the num_stripes is corrupted. Error out anyway.
Reviewed-by: Josef Bacik josef@toxicpanda.com Signed-off-by: Qu Wenruo wqu@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/tree-checker.c | 40 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c index 91ea38506fbb7..84b8d6ebf98f3 100644 --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -674,6 +674,44 @@ int btrfs_check_chunk_valid(struct extent_buffer *leaf, return 0; }
+/* + * Enhanced version of chunk item checker. + * + * The common btrfs_check_chunk_valid() doesn't check item size since it needs + * to work on super block sys_chunk_array which doesn't have full item ptr. + */ +static int check_leaf_chunk_item(struct extent_buffer *leaf, + struct btrfs_chunk *chunk, + struct btrfs_key *key, int slot) +{ + int num_stripes; + + if (btrfs_item_size_nr(leaf, slot) < sizeof(struct btrfs_chunk)) { + chunk_err(leaf, chunk, key->offset, + "invalid chunk item size: have %u expect [%zu, %u)", + btrfs_item_size_nr(leaf, slot), + sizeof(struct btrfs_chunk), + BTRFS_LEAF_DATA_SIZE(leaf->fs_info)); + return -EUCLEAN; + } + + num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + /* Let btrfs_check_chunk_valid() handle this error type */ + if (num_stripes == 0) + goto out; + + if (btrfs_chunk_item_size(num_stripes) != + btrfs_item_size_nr(leaf, slot)) { + chunk_err(leaf, chunk, key->offset, + "invalid chunk item size: have %u expect %lu", + btrfs_item_size_nr(leaf, slot), + btrfs_chunk_item_size(num_stripes)); + return -EUCLEAN; + } +out: + return btrfs_check_chunk_valid(leaf, chunk, key->offset); +} + __printf(3, 4) __cold static void dev_item_err(const struct extent_buffer *eb, int slot, @@ -1265,7 +1303,7 @@ static int check_leaf_item(struct extent_buffer *leaf, break; case BTRFS_CHUNK_ITEM_KEY: chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); - ret = btrfs_check_chunk_valid(leaf, chunk, key->offset); + ret = check_leaf_chunk_item(leaf, chunk, key, slot); break; case BTRFS_DEV_ITEM_KEY: ret = check_dev_item(leaf, key, slot);