From: David Leadbeater <dgl@dgl.cx> 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=... --------------------------- [ 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); -- 2.20.1