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: 869f37d8 ("[NETFILTER]: nf_conntrack/nf_nat: add IRC helper port")
Signed-off-by: David Leadbeater <dgl@xxxxxx>
---
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 3b9d6f8ba436..5703846bea3b 100644
--- a/net/netfilter/nf_conntrack_irc.c
+++ b/net/netfilter/nf_conntrack_irc.c
@@ -216,8 +216,9 @@ 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);
--
2.37.1
