@@ -2179,7 +2179,7 @@ static void scrub_missing_raid56_pages(struct scrub_block *sblock)
struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
u64 length = sblock->page_count * PAGE_SIZE;
u64 logical = sblock->pagev[0]->logical;
- struct btrfs_bio *bbio;
+ struct btrfs_bio *bbio = NULL;
struct bio *bio;
struct btrfs_raid_bio *rbio;
int ret;
@@ -2980,6 +2980,7 @@ again:
extent_len);
mapped_length = extent_len;
+ bbio = NULL;
ret = btrfs_map_block(fs_info, READ, extent_logical,
&mapped_length, &bbio, 0);
if (!ret) {
We usually call btrfs_put_bbio() when btrfs_map_block() failed, btrfs_put_bbio() works right whether bbio is a valid value, or NULL. But there is a exception, in some case, btrfs_map_block() will return fail without touching *bbio(keeping its original value), and if bbio was not initialized yet, invalid memory accessing will happened. Above case is in scrub_missing_raid56_pages(), and similar case in scrub_raid56_parity(). Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> --- fs/btrfs/scrub.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)