Btrfs: fix NULL pointer dereference in log_dir_items

0, 1 and <0 can be returned by btrfs_next_leaf(), and when <0 is
returned, path->nodes[0] could be NULL, log_dir_items lacks such a
check for <0 and we may run into a null pointer dereference panic.

Fixes: e02119d5a7 ("Btrfs: Add a write ahead tree log to optimize synchronous operations")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Liu Bo 2018-04-03 01:59:47 +08:00 committed by David Sterba
parent 57599c7e77
commit 80c0b4210a
1 changed files with 5 additions and 2 deletions

View File

@ -3520,8 +3520,11 @@ static noinline int log_dir_items(struct btrfs_trans_handle *trans,
* from this directory and from this transaction
*/
ret = btrfs_next_leaf(root, path);
if (ret == 1) {
last_offset = (u64)-1;
if (ret) {
if (ret == 1)
last_offset = (u64)-1;
else
err = ret;
goto done;
}
btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);