From e3d35e92db274383676eb003cb6dabaf8abbc40d Mon Sep 17 00:00:00 2001
From: David Leadbeater <dgl@dgl.cx>
Date: Thu, 13 Oct 2022 14:51:14 +0800
Subject: [PATCH] netfilter: nf_conntrack_irc: Fix forged IP logic
stable inclusion
from stable-v5.10.143
commit e12ce30fe593dd438c5b392290ad7316befc11ca
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5OWZ7
CVE: CVE-2022-2663
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e12ce30fe593dd438c5b392290ad7316befc11ca
---------------------------
[ 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>
Signed-off-by: Liu Jian <liujian56@huawei.com>
Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
---
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 c745dd19d42f..65b5b05fe38d 100644
--- a/net/netfilter/nf_conntrack_irc.c
+++ b/net/netfilter/nf_conntrack_irc.c
@@ -207,8 +207,9 @@ 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);
--
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