From: Changli Gao <xiaosuo@gmail.com>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Patrick McHardy <kaber@trash.net>,
"David S. Miller" <davem@davemloft.net>,
netfilter-devel@vger.kernel.org, netdev@vger.kernel.org,
Changli Gao <xiaosuo@gmail.com>
Subject: [PATCH] netfilter: check the length of the data before dereferencing it
Date: Sun, 1 Apr 2012 22:22:50 +0800 [thread overview]
Message-ID: <1333290170-26898-1-git-send-email-xiaosuo@gmail.com> (raw)
We should check the length of the data before dereferencing it when parsing
the TCP options.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
---
net/netfilter/nf_conntrack_proto_tcp.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 361eade..9e446c5 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -404,6 +404,8 @@ static void tcp_options(const struct sk_buff *skb,
length--;
continue;
default:
+ if (length < 2)
+ return;
opsize=*ptr++;
if (opsize < 2) /* "silly options" */
return;
@@ -464,6 +466,8 @@ static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
length--;
continue;
default:
+ if (length < 2)
+ return;
opsize = *ptr++;
if (opsize < 2) /* "silly options" */
return;
next reply other threads:[~2012-04-01 14:25 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-01 14:22 Changli Gao [this message]
2012-04-01 16:43 ` [PATCH] netfilter: check the length of the data before dereferencing it Pablo Neira Ayuso
2012-04-01 16:55 ` Eric Dumazet
2012-04-01 17:02 ` Pablo Neira Ayuso
2012-04-02 3:05 ` Changli Gao
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