diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 24f6404..84d693d 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -299,6 +299,9 @@
 	struct cred *override_cred;
 	char *link = NULL;
 
+	if (WARN_ON(!workdir))
+		return -EROFS;
+
 	ovl_path_upper(parent, &parentpath);
 	upperdir = parentpath.dentry;