From: David Leadbeater dgl@dgl.cx
[ Upstream commit 0efe125cfb99e6773a7434f3463f7c2fa28f3a43 ]
Ensure the match happens in the right direction, previously the destination used was the server, not the NAT host, as the comment shows the code intended.
Additionally nf_nat_irc uses port 0 as a signal and there's no valid way it can appear in a DCC message, so consider port 0 also forged.
Fixes: 869f37d8e48f ("[NETFILTER]: nf_conntrack/nf_nat: add IRC helper port") Signed-off-by: David Leadbeater dgl@dgl.cx Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nf_conntrack_irc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/nf_conntrack_irc.c b/net/netfilter/nf_conntrack_irc.c index 5523acce9d699..814220f7be676 100644 --- a/net/netfilter/nf_conntrack_irc.c +++ b/net/netfilter/nf_conntrack_irc.c @@ -187,8 +187,9 @@ static int help(struct sk_buff *skb, unsigned int protoff,
/* dcc_ip can be the internal OR external (NAT'ed) IP */ tuple = &ct->tuplehash[dir].tuple; - if (tuple->src.u3.ip != dcc_ip && - tuple->dst.u3.ip != dcc_ip) { + if ((tuple->src.u3.ip != dcc_ip && + ct->tuplehash[!dir].tuple.dst.u3.ip != dcc_ip) || + dcc_port == 0) { net_warn_ratelimited("Forged DCC command from %pI4: %pI4:%u\n", &tuple->src.u3.ip, &dcc_ip, dcc_port);