diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index b44eaf40bb29..4a2412127d8f 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -715,8 +715,11 @@ static void backend_changed(struct xenbus_watch *watch,
 
 	/* Front end dir is a number, which is used as the handle. */
 	err = kstrtoul(strrchr(dev->otherend, '/') + 1, 0, &handle);
-	if (err)
+	if (err) {
+		kfree(be->mode);
+		be->mode = NULL;
 		return;
+	}
 
 	be->major = major;
 	be->minor = minor;