Merge tag 'ipvs-fixes-for-v4.12' of http://git.kernel.org/pub/scm/linux/kernel/git/horms/ipvs

Simon Horman says:

====================
IPVS Fixes for v4.12

please consider this fix to IPVS for v4.12.

* It is a fix from Julian Anastasov to only SNAT SNAT packet replies only for
NATed connections

My understanding is that this fix is appropriate for 4.9.25, 4.10.13, 4.11
as well as the nf tree. Julian has separately posted backports for other
-stable kernels; please see:

* [PATCH 3.2.88,3.4.113 -stable 1/3] ipvs: SNAT packet replies only for
NATed connections
* [PATCH 3.10.105,3.12.73,3.16.43,4.1.39 -stable 2/3] ipvs: SNAT packet
replies only for NATed connections
* [PATCH 4.4.65 -stable 3/3] ipvs: SNAT packet replies only for NATed
connections
====================

Signed-off-by: Pablo Neira Ayuso <[e-mail]>

net/netfilter/ipvs/ip_vs_core.c

···
 {
 	unsigned int verdict = NF_DROP;
 
-	if (IP_VS_FWD_METHOD(cp) != 0) {
-		pr_err("shouldn't reach here, because the box is on the "
-		       "half connection in the tun/dr module.\n");
-	}
+	if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
+		goto ignore_cp;
 
 	/* Ensure the checksum is correct */
 	if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
···
 		ip_vs_notrack(skb);
 	else
 		ip_vs_update_conntrack(skb, cp, 0);
+
+ignore_cp:
 	verdict = NF_ACCEPT;
 
 out:
···
 	 */
 	cp = pp->conn_out_get(ipvs, af, skb, &iph);
 
-	if (likely(cp))
+	if (likely(cp)) {
+		if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
+			goto ignore_cp;
 		return handle_response(af, skb, pd, cp, &iph, hooknum);
+	}
 
 	/* Check for real-server-started requests */
 	if (atomic_read(&ipvs->conn_out_counter)) {
···
 			}
 		}
 	}
+
+out:
 	IP_VS_DBG_PKT(12, af, pp, skb, iph.off,
 		      "ip_vs_out: packet continues traversal as normal");
 	return NF_ACCEPT;
+
+ignore_cp:
+	__ip_vs_conn_put(cp);
+	goto out;
 }
 
 /*