diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fd172a93d11a..1a508fff7afe 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2206,7 +2206,7 @@ static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
 	if (!path)
 		return -ENOMEM;
 
-	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
+	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
 
 	key.objectid = tree_id;
 	key.type = BTRFS_ROOT_ITEM_KEY;