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authorDavid Leadbeater <dgl@dgl.cx>2022-08-26 14:56:58 +1000
committerPablo Neira Ayuso <pablo@netfilter.org>2022-09-01 02:01:56 +0200
commit0efe125cfb99e6773a7434f3463f7c2fa28f3a43 (patch)
tree330bb73faf138404fc0b687822fbb8342521069b /net/netfilter
parent77972a36ecc4db7fc7c68f0e80714263c5f03f65 (diff)
netfilter: nf_conntrack_irc: Fix forged IP logic
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>
Diffstat (limited to 'net/netfilter')
-rw-r--r--net/netfilter/nf_conntrack_irc.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/net/netfilter/nf_conntrack_irc.c b/net/netfilter/nf_conntrack_irc.c
index 1796c456ac98..992decbcaa5c 100644
--- a/net/netfilter/nf_conntrack_irc.c
+++ b/net/netfilter/nf_conntrack_irc.c
@@ -194,8 +194,9 @@ 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);