提交 49f817d7 编写于 作者: L Lin Zhang 提交者: Pablo Neira Ayuso

netfilter: SYNPROXY: skip non-tcp packet in {ipv4, ipv6}_synproxy_hook

In function {ipv4,ipv6}_synproxy_hook we expect a normal tcp packet, but
the real server maybe reply an icmp error packet related to the exist
tcp conntrack, so we will access wrong tcp data.

Fix it by checking for the protocol field and only process tcp traffic.
Signed-off-by: NLin Zhang <xiaolou4617@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
上级 e466af75
......@@ -330,7 +330,8 @@ static unsigned int ipv4_synproxy_hook(void *priv,
if (synproxy == NULL)
return NF_ACCEPT;
if (nf_is_loopback_packet(skb))
if (nf_is_loopback_packet(skb) ||
ip_hdr(skb)->protocol != IPPROTO_TCP)
return NF_ACCEPT;
thoff = ip_hdrlen(skb);
......
......@@ -353,7 +353,7 @@ static unsigned int ipv6_synproxy_hook(void *priv,
nexthdr = ipv6_hdr(skb)->nexthdr;
thoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
&frag_off);
if (thoff < 0)
if (thoff < 0 || nexthdr != IPPROTO_TCP)
return NF_ACCEPT;
th = skb_header_pointer(skb, thoff, sizeof(_th), &_th);
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册