diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index fb36f85..410db90 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -1178,6 +1178,7 @@
 		if (type > OVS_KEY_ATTR_MAX) {
 			OVS_NLERR("Unknown key attribute (type=%d, max=%d).\n",
 				  type, OVS_KEY_ATTR_MAX);
+			return -EINVAL;
 		}
 
 		if (attrs & (1 << type)) {