Some btrfs created by old mkfs.btrfs can have tree block with 0 bytenr.
In fact, any aligned bytenr is allowed in btrfs, and in some case it can
cause problem if the valid tree block at 0 bytenr can't be read.
Currently, the superblock checker and bytenr alignment checker can
already handle the case so there is no need to check bytenr < sectorsize
in read_tree_block().
Reported-by: Benjamin Beichler <hadrian2002@xxxxxxxxxxxxxx>
Fixes: 6cca2ea9bea9 ("btrfs-progs: more sanity checks in read_tree_block_fs_info")
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
---
disk-io.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/disk-io.c b/disk-io.c
index f5edc4796619..7f13f05ac600 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -318,7 +318,7 @@ struct extent_buffer* read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
* Such unaligned tree block will free overlapping extent buffer,
* causing use-after-free bugs for fuzzed images.
*/
- if (bytenr < sectorsize || !IS_ALIGNED(bytenr, sectorsize)) {
+ if (!IS_ALIGNED(bytenr, sectorsize)) {
error("tree block bytenr %llu is not aligned to sectorsize %u",
bytenr, sectorsize);
return ERR_PTR(-EIO);
--
2.15.1
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