linux-kernel - [PATCH v2 1/1] nf_conntrack_ftp: Added nfct_seqadj_ext

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]

Message-ID: <20251016104802.567812-2-a.melnychenko@vyos.io>
Date: Thu, 16 Oct 2025 12:48:01 +0200
From: Andrii Melnychenko <a.melnychenko@...s.io>
To: pablo@...filter.org,
	kadlec@...filter.org,
	fw@...len.de,
	phil@....cc
Cc: davem@...emloft.net,
	edumazet@...gle.com,
	kuba@...nel.org,
	pabeni@...hat.com,
	horms@...nel.org,
	netfilter-devel@...r.kernel.org,
	coreteam@...filter.org,
	netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH v2 1/1] nf_conntrack_ftp: Added nfct_seqadj_ext_add() for ftp's conntrack.

There was an issue with NAT'ed ftp and replaced messages
for PASV/EPSV mode. "New" IP in the message may have a
different length that would require sequence adjustment.

Signed-off-by: Andrii Melnychenko <a.melnychenko@...s.io>
---
 net/netfilter/nf_conntrack_ftp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index 617f744a2..0216bc099 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -25,6 +25,7 @@
 #include <net/netfilter/nf_conntrack_ecache.h>
 #include <net/netfilter/nf_conntrack_helper.h>
 #include <linux/netfilter/nf_conntrack_ftp.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
 
 #define HELPER_NAME "ftp"
 
@@ -390,6 +391,8 @@ static int help(struct sk_buff *skb,
 	/* Until there's been traffic both ways, don't look in packets. */
 	if (ctinfo != IP_CT_ESTABLISHED &&
 	    ctinfo != IP_CT_ESTABLISHED_REPLY) {
+		if (!nf_ct_is_confirmed(ct))
+			nfct_seqadj_ext_add(ct);
 		pr_debug("ftp: Conntrackinfo = %u\n", ctinfo);
 		return NF_ACCEPT;
 	}
-- 
2.43.0