From d00a875ed2cba63637d768fdfab42bec20d989b4 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 25 Apr 2017 16:40:16 +0800 Subject: [PATCH] btrfs-progs: Use more strict check to read out tree root Fuzzed image bko-156811-bad-parent-ref-qgroup-verify.raw causes qgroup to report -ENOMEM. But the fact is, such image is heavily damaged so there is no valid root item for the extent tree. Normal extent tree key in root tree should be (EXTENT_TREE ROOT_ITEM 0), while in that fuzzed image, we got (EXTENT_TREE EXXTENT_DATA SOME_NUMBER). It's btrfs_find_last_root() that only checks the objectid, not caring about the key type leading to such problem. Fix it by doing extra check on key type. Signed-off-by: Qu Wenruo [ edit changelog ] Signed-off-by: David Sterba --- root-tree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/root-tree.c b/root-tree.c index ab01a140..6b8f8c1c 100644 --- a/root-tree.c +++ b/root-tree.c @@ -51,7 +51,8 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, l = path->nodes[0]; slot = path->slots[0] - 1; btrfs_item_key_to_cpu(l, &found_key, slot); - if (found_key.objectid != objectid) { + if (found_key.type != BTRFS_ROOT_ITEM_KEY || + found_key.objectid != objectid) { ret = -ENOENT; goto out; }