diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 7dbc4f308dbe..09722598994d 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -971,8 +971,14 @@ skip_family:
 	if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
 		entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
 
-	if (tb[MPTCP_PM_ADDR_ATTR_PORT])
+	if (tb[MPTCP_PM_ADDR_ATTR_PORT]) {
+		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
+			NL_SET_ERR_MSG_ATTR(info->extack, attr,
+					    "flags must have signal when using port");
+			return -EINVAL;
+		}
 		entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
+	}
 
 	return 0;
 }