diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 67fbf6e48a30..13052408a132 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -2953,6 +2953,8 @@ static int validate_set(const struct nlattr *a,
 	case OVS_KEY_ATTR_MPLS:
 		if (!eth_p_mpls(eth_type))
 			return -EINVAL;
+		if (key_len != sizeof(struct ovs_key_mpls))
+			return -EINVAL;
 		break;
 
 	case OVS_KEY_ATTR_SCTP: