Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next

Pablo Neira Ayuso says:

====================
The following batch contains:

* Three fixes for the new synproxy target available in your
  net-next tree, from Jesper D. Brouer and Patrick McHardy.

* One fix for TCPMSS to correctly handling the fragmentation
  case, from Phil Oester. I'll pass this one to -stable.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/netfilter/ipt_SYNPROXY.c

@@ -269,7 +269,7 @@ synproxy_tg4(struct sk_buff *skb, const struct xt_action_param *par)
 
 	synproxy_parse_options(skb, par->thoff, th, &opts);
 
-	if (th->syn && !th->ack) {
+	if (th->syn && !(th->ack || th->fin || th->rst)) {
 		/* Initial SYN from client */
 		this_cpu_inc(snet->stats->syn_received);
 
@@ -285,11 +285,15 @@ synproxy_tg4(struct sk_buff *skb, const struct xt_action_param *par)
 					  XT_SYNPROXY_OPT_ECN);
 
 		synproxy_send_client_synack(skb, th, &opts);
-	} else if (th->ack && !(th->fin || th->rst))
+		return NF_DROP;
+
+	} else if (th->ack && !(th->fin || th->rst || th->syn)) {
 		/* ACK from client */
 		synproxy_recv_client_ack(snet, skb, th, &opts, ntohl(th->seq));
+		return NF_DROP;
+	}
 
-	return NF_DROP;
+	return XT_CONTINUE;
 }
 
 static unsigned int ipv4_synproxy_hook(unsigned int hooknum,

net/ipv6/netfilter/ip6t_SYNPROXY.c

@@ -284,7 +284,7 @@ synproxy_tg6(struct sk_buff *skb, const struct xt_action_param *par)
 
 	synproxy_parse_options(skb, par->thoff, th, &opts);
 
-	if (th->syn) {
+	if (th->syn && !(th->ack || th->fin || th->rst)) {
 		/* Initial SYN from client */
 		this_cpu_inc(snet->stats->syn_received);
 
@@ -300,11 +300,15 @@ synproxy_tg6(struct sk_buff *skb, const struct xt_action_param *par)
 					  XT_SYNPROXY_OPT_ECN);
 
 		synproxy_send_client_synack(skb, th, &opts);
-	} else if (th->ack && !(th->fin || th->rst))
+		return NF_DROP;
+
+	} else if (th->ack && !(th->fin || th->rst || th->syn)) {
 		/* ACK from client */
 		synproxy_recv_client_ack(snet, skb, th, &opts, ntohl(th->seq));
+		return NF_DROP;
+	}
 
-	return NF_DROP;
+	return XT_CONTINUE;
 }
 
 static unsigned int ipv6_synproxy_hook(unsigned int hooknum,

net/netfilter/nf_synproxy_core.c

@@ -356,12 +356,12 @@ static int __net_init synproxy_net_init(struct net *net)
 		goto err1;
 	}
 
-	__set_bit(IPS_TEMPLATE_BIT, &ct->status);
-	__set_bit(IPS_CONFIRMED_BIT, &ct->status);
 	if (!nfct_seqadj_ext_add(ct))
 		goto err2;
 	if (!nfct_synproxy_ext_add(ct))
 		goto err2;
+	__set_bit(IPS_TEMPLATE_BIT, &ct->status);
+	__set_bit(IPS_CONFIRMED_BIT, &ct->status);
 
 	snet->tmpl = ct;
 

net/netfilter/xt_TCPMSS.c

@@ -60,7 +60,7 @@ tcpmss_mangle_packet(struct sk_buff *skb,
 
 	/* This is a fragment, no TCP header is available */
 	if (par->fragoff != 0)
-		return XT_CONTINUE;
+		return 0;
 
 	if (!skb_make_writable(skb, skb->len))
 		return -1;