5.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> commit 669e859b5ea7c6f4fce0149d3907c64e550c294b upstream. We should drop the lock on this error path. This has been found by a static tool. The lock needs to be released, it's there to protect access to the dev_replace members and is not supposed to be left locked. The value of state that's being switched would need to be artifically changed to an invalid value so the default: branch is taken. Fixes: d189dd70e255 ("btrfs: fix use-after-free due to race between replace start and cancel") CC: stable@xxxxxxxxxxxxxxx # 5.0+ Reviewed-by: Anand Jain <anand.jain@xxxxxxxxxx> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/dev-replace.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -862,6 +862,7 @@ int btrfs_dev_replace_cancel(struct btrf btrfs_destroy_dev_replace_tgtdev(tgt_device); break; default: + up_write(&dev_replace->rwsem); result = -EINVAL; }