linux-kernel - [PATCH 5.4 095/108] netfilter: nf_conntrack

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 13 Sep 2022 16:07:06 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, David Leadbeater <dgl@....cx>,
        Pablo Neira Ayuso <pablo@...filter.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.4 095/108] netfilter: nf_conntrack_irc: Fix forged IP logic

From: David Leadbeater <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@....cx>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
Signed-off-by: Sasha Levin <sashal@...nel.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 e40988a2f22fb..26245419ef4a9 100644
--- a/net/netfilter/nf_conntrack_irc.c
+++ b/net/netfilter/nf_conntrack_irc.c
@@ -185,8 +185,9 @@ 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);
-- 
2.35.1