diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index ce7cb87479fe..407d0e9adfaf 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -713,7 +713,7 @@ int chsc_determine_base_channel_path_desc(struct chp_id chpid,
 	ret = chsc_determine_channel_path_desc(chpid, 0, 0, 0, 0, chsc_resp);
 	if (ret)
 		goto out_free;
-	memcpy(desc, &chsc_resp->data, chsc_resp->length);
+	memcpy(desc, &chsc_resp->data, sizeof(*desc));
 out_free:
 	kfree(chsc_resp);
 	return ret;