From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.70.190.124 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793581033; b=vqpVbXGe4y1B56QKpWy2eZT/wVlu4rJElJsVR/QtetdCHexOg0bvQj91Sght8s3ikHJB gtdH2aQu/A3E53vESNQUGXTKKqadSoPZx1t5uicuQ3CQvtvClX8pIXdBTy72D8AORHdO2 v1QJ6rJzkWriVaLuAeeSSqY8jkT7g0IC8NCMHQrMK6VVHWLRduBTYhe9Hs+R83LSyzvCZ AJ5ojeIQKez9wJPTFojL6tfPTgiPt6+MnYbKxU73nELsOdXp3p2Q47Rt5U/hqDOYMleKh pJGgPWDaf4bTH1dKSEtp3bjnX1u1jQ8ecm5p4TuVfxoNNhs2AB845U+DU6a6azomXZQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793581033; h=DMARC-Filter:DKIM-Signature:Received:From:To:Cc:Subject:Date: Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding:X-Spam-Status:X-Spam-Checker-Version; bh=rtTKULpTnN+Nv7hj6YAwU1fNR5t0PXlCdJ7mWoX/Fc0=; b=WxBjikcx7Pg6N7G+/YQXTxZgG9SMZg1Z6YR+YOcxjAy8x1ZWkq/vtD7XNz1HrwdZnBYc nwarPkaoSE2D+WqEcAv6o6UET8658wg7borQQrN3uDQSdlMGSyGrZ7BZClkeqK9sIQAAw 5/Bre3ebDJziOawgmxP4RfYl8eoLrFeCeaNVdHhHIWq9HUifJIiTJYRCiyq0djF8JHY4x 12Vh10tMHoAMXxdVc5wXFUUJAr/rXIckgILgfdA1Pgi0+VnutDJ4EE1uzTRcl1+cCQY5g nbNqp+Xlh5+BSDVw8wofEIvj3fQ5I0h22FzCHkbVH+EbVWK2yVZBy+7y624e52tbhpg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; dkim=pass header.d=netfilter.org header.i=@netfilter.org header.a=rsa-sha256 header.s=2025 header.b=dknDax5a; arc=none smtp.remote-ip=217.70.190.124 Received: from mail.netfilter.org (mail.netfilter.org [217.70.190.124]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 458E3606A339; Mon, 2 Nov 2026 00:57:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 458E3606A339 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=netfilter.org header.i=@netfilter.org header.a=rsa-sha256 header.s=2025 header.b=dknDax5a DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1793581031; bh=rtTKULpTnN+Nv7hj6YAwU1fNR5t0PXlCdJ7mWoX/Fc0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dknDax5a3I6aEl7RHVBfToDG422Jq93z0IhckCyIkXFlQnCvTsaCYWx6PxLr8Yduy JfJfMKltm8lUsnxF/rUIF5zuICC3ZAsGNr3kJiJOUhDFq7BiO20fXbqrDOBj2Fmlv3 i4TnM4nD+tPkZ4UgpirS6gsTVwP/rRZ7h1oS2DEsuo2MQhg9Dz9C8DFH5pH651qZge +vIZPmb/WlxaYfcjBCT8VGLkXEGaCk8pF3AMfZ35wHcOCctSE4beBB4lbmXRsRpDGt resfnev4M6/cBgSgv9xcbk8RriqgfUyayTGhxSJ0dB2R7dvhgn73fBtTvw1akRYJt/ RI0X20/hEXl4g== Received: from localhost.localdomain (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with ESMTPSA id CEE786007A; Mon, 2 Nov 2026 01:57:10 +0100 (CET) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@kernel.org, horms@kernel.org, fw@strlen.de, ja@ssi.bg Subject: [PATCH net 05/15] ipvs: do not create conns from packets with port 0 Date: Mon, 2 Nov 2026 01:56:44 +0100 Message-ID: <20261102005654.532438-6-pablo@netfilter.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261102005654.532438-1-pablo@netfilter.org> References: <20261102005654.532438-1-pablo@netfilter.org> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Julian Anastasov We should disallow normal connections with cport 0 to be created from packets by the scheduler (from clients) or by ip_vs_new_conn_out (from real servers) because later such traffic can not hit the connection due to the NO_CPORT requirement. As result, it can lead to duplicate connection for every packet. Do the same for vport 0. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Link: https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260925141115.16126-1-axel.mierczuk%401password.com Signed-off-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipvs/ip_vs_core.c | 3 ++- net/netfilter/ipvs/ip_vs_proto_sctp.c | 5 +++++ net/netfilter/ipvs/ip_vs_proto_tcp.c | 5 +++++ net/netfilter/ipvs/ip_vs_proto_udp.c | 4 ++++ 4 files changed, 16 insertions(+), 1 deletion(-) diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 8a3c880fdb26..f3eb72e95024 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -1305,6 +1305,7 @@ static inline bool is_new_conn_expected(const struct ip_vs_conn *cp, * In fwmark-VS actual vaddr and vport are unknown to IPVS * 2) Real Server and Virtual Service were NOT configured without port: * This is to allow match of different VS to the same RS ip-addr + * 3) Client port is not 0 */ struct ip_vs_conn *ip_vs_new_conn_out(struct ip_vs_service *svc, struct ip_vs_dest *dest, @@ -1328,7 +1329,7 @@ struct ip_vs_conn *ip_vs_new_conn_out(struct ip_vs_service *svc, /* check pre-requisites are satisfied */ if (svc->fwmark) return NULL; - if (!vport || !dport) + if (!vport || !dport || !cport) return NULL; /* for persistent service first create connection template */ diff --git a/net/netfilter/ipvs/ip_vs_proto_sctp.c b/net/netfilter/ipvs/ip_vs_proto_sctp.c index fb8af6b15a39..83d1443ebe01 100644 --- a/net/netfilter/ipvs/ip_vs_proto_sctp.c +++ b/net/netfilter/ipvs/ip_vs_proto_sctp.c @@ -30,6 +30,7 @@ sctp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb, sch = skb_header_pointer(skb, iph->len + sizeof(_sctph), sizeof(_schunkh), &_schunkh); if (sch) { + /* Accept packet without scheduling? */ if (sch->type == SCTP_CID_ABORT || !(sysctl_sloppy_sctp(ipvs) || sch->type == SCTP_CID_INIT)) @@ -47,6 +48,10 @@ sctp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb, return 0; } + /* Do not create connection for port 0, skip the packet */ + if (!ports[0] || !ports[1]) + return 1; + if (likely(!ip_vs_iph_inverse(iph))) svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol, &iph->daddr, ports[1]); diff --git a/net/netfilter/ipvs/ip_vs_proto_tcp.c b/net/netfilter/ipvs/ip_vs_proto_tcp.c index fec0e8b47b71..2e55b62445c6 100644 --- a/net/netfilter/ipvs/ip_vs_proto_tcp.c +++ b/net/netfilter/ipvs/ip_vs_proto_tcp.c @@ -48,6 +48,7 @@ tcp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb, if (likely(!ip_vs_iph_icmp(iph))) { th = skb_header_pointer(skb, iph->len, sizeof(_tcph), &_tcph); if (th) { + /* Accept packet without scheduling? */ if (th->rst || !(sysctl_sloppy_tcp(ipvs) || th->syn)) return 1; ports = &th->source; @@ -62,6 +63,10 @@ tcp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb, return 0; } + /* Do not create connection for port 0, skip the packet */ + if (!ports[0] || !ports[1]) + return 1; + /* No !th->ack check to allow scheduling on SYN+ACK for Active FTP */ if (likely(!ip_vs_iph_inverse(iph))) diff --git a/net/netfilter/ipvs/ip_vs_proto_udp.c b/net/netfilter/ipvs/ip_vs_proto_udp.c index f32785682402..92c0b76c1a02 100644 --- a/net/netfilter/ipvs/ip_vs_proto_udp.c +++ b/net/netfilter/ipvs/ip_vs_proto_udp.c @@ -52,6 +52,10 @@ udp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb, return 0; } + /* Do not create connection for port 0, skip the packet */ + if (!ports[0] || !ports[1]) + return 1; + if (likely(!ip_vs_iph_inverse(iph))) svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol, &iph->daddr, ports[1]); -- 2.47.3