netfilter: Validate the sequence number of dataless ACK packets as well
authorJozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Fri, 31 Aug 2012 09:55:54 +0000 (09:55 +0000)
committerPablo Neira Ayuso <pablo@netfilter.org>
Sun, 9 Sep 2012 20:13:49 +0000 (22:13 +0200)
commit4a70bbfaef0361d27272629d1a250a937edcafe4
tree8389e2f3b55cfcec5770a9fd83b9a52c31e4128b
parent64f509ce71b08d037998e93dd51180c19b2f464c
netfilter: Validate the sequence number of dataless ACK packets as well

We spare nothing by not validating the sequence number of dataless
ACK packets and enabling it makes harder off-path attacks.

See: "Reflection scan: an Off-Path Attack on TCP" by Jan Wrobel,
http://arxiv.org/abs/1201.2074

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
net/netfilter/nf_conntrack_proto_tcp.c