Btrfs: fix NULL pointer dereference in log_dir_items
authorLiu Bo <bo.liu@linux.alibaba.com>
Mon, 2 Apr 2018 17:59:47 +0000 (01:59 +0800)
committerDavid Sterba <dsterba@suse.com>
Thu, 5 Apr 2018 17:22:17 +0000 (19:22 +0200)
commit80c0b4210a963e31529e15bf90519708ec947596
tree526c3e6f1bdc12aabf541687a992c806576aaa5b
parent57599c7e7722daf5f8c2dba4b0e4628f5c500771
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: e02119d5a7b4 ("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>
fs/btrfs/tree-log.c