--- a/net/netfilter/nf_conntrack_sip.c	2017-05-25 07:54:45.000000000 +0200
+++ b/net/netfilter/nf_conntrack_sip.c	2017-05-25 19:25:51.771419668 +0200
@@ -1624,13 +1624,14 @@
 
 static int __init nf_conntrack_sip_init(void)
 {
-	int i, ret;
+	int i, j, ret;
 
 	if (ports_c == 0)
 		ports[ports_c++] = SIP_PORT;
 
 	for (i = 0; i < ports_c; i++) {
-		memset(&sip[i], 0, sizeof(sip[i]));
+		for (j = 0; j < 3; j++)
+			memset(&sip[4 * i + j], 0, sizeof(sip[0]));
 
 		nf_ct_helper_init(&sip[4 * i], AF_INET, IPPROTO_UDP, "sip",
 				  SIP_PORT, ports[i], ports[i], sip_exp_policy,