btrfs: fix possible memory leak in btrfs_get_dev_args_from_path()

In btrfs_get_dev_args_from_path(), btrfs_get_bdev_and_sb() can fail if
the path is invalid. In this case, btrfs_get_dev_args_from_path()
returns directly without freeing args->uuid and args->fsid allocated
before, which causes memory leak.

To fix these possible leaks, when btrfs_get_bdev_and_sb() fails,
btrfs_put_dev_args_from_path() is called to clean up the memory.
Reported-by: NTOTE Robot <oslab@tsinghua.edu.cn>
Fixes: faa775c4 ("btrfs: add a btrfs_get_dev_args_from_path helper")
CC: stable@vger.kernel.org # 5.16
Reviewed-by: NBoris Burkov <boris@bur.io>
Signed-off-by: NZixuan Fu <r33s3n6@gmail.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/volumes.c

@@ -2345,8 +2345,11 @@ int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info,
 
 	ret = btrfs_get_bdev_and_sb(path, FMODE_READ, fs_info->bdev_holder, 0,
 				    &bdev, &disk_super);
-	if (ret)
+	if (ret) {
+		btrfs_put_dev_args_from_path(args);
 		return ret;
+	}
+
 	args->devid = btrfs_stack_device_id(&disk_super->dev_item);
 	memcpy(args->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE);
 	if (btrfs_fs_incompat(fs_info, METADATA_UUID))