From patchwork Thu May 9 09:38:05 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilya Maximets X-Patchwork-Id: 1933379 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=openvswitch.org (client-ip=2605:bc80:3010::137; helo=smtp4.osuosl.org; envelope-from=ovs-dev-bounces@openvswitch.org; receiver=patchwork.ozlabs.org) Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4VZn9K0P3fz20fc for ; Thu, 9 May 2024 19:42:12 +1000 (AEST) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id E85464155D; Thu, 9 May 2024 09:42:05 +0000 (UTC) X-Virus-Scanned: amavis at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavis, port 10024) with ESMTP id 0-53hofMOt1i; Thu, 9 May 2024 09:42:04 +0000 (UTC) X-Comment: SPF check N/A for local connections - client-ip=140.211.9.56; helo=lists.linuxfoundation.org; envelope-from=ovs-dev-bounces@openvswitch.org; receiver= DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 6C7FC40325 Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp4.osuosl.org (Postfix) with ESMTPS id 6C7FC40325; Thu, 9 May 2024 09:42:04 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 46E26C0077; Thu, 9 May 2024 09:42:04 +0000 (UTC) X-Original-To: dev@openvswitch.org Delivered-To: ovs-dev@lists.linuxfoundation.org Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 33262C0037 for ; Thu, 9 May 2024 09:42:02 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 1A8964017B for ; Thu, 9 May 2024 09:42:02 +0000 (UTC) X-Virus-Scanned: amavis at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavis, port 10024) with ESMTP id UgKsZbVfXKiE for ; Thu, 9 May 2024 09:42:01 +0000 (UTC) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2001:4b98:dc4:8::229; helo=relay9-d.mail.gandi.net; envelope-from=i.maximets@ovn.org; receiver= DMARC-Filter: OpenDMARC Filter v1.4.2 smtp2.osuosl.org 8A7BA400AC Authentication-Results: smtp2.osuosl.org; dmarc=none (p=none dis=none) header.from=ovn.org DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 8A7BA400AC Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::229]) by smtp2.osuosl.org (Postfix) with ESMTPS id 8A7BA400AC for ; Thu, 9 May 2024 09:41:59 +0000 (UTC) Received: by mail.gandi.net (Postfix) with ESMTPSA id 7FE32FF804; Thu, 9 May 2024 09:41:55 +0000 (UTC) From: Ilya Maximets To: netdev@vger.kernel.org Date: Thu, 9 May 2024 11:38:05 +0200 Message-ID: <20240509094228.1035477-1-i.maximets@ovn.org> X-Mailer: git-send-email 2.44.0 MIME-Version: 1.0 X-GND-Sasl: i.maximets@ovn.org Cc: dev@openvswitch.org, Antonin Bas , linux-kernel@vger.kernel.org, Ilya Maximets , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "David S. Miller" Subject: [ovs-dev] [PATCH net] net: openvswitch: fix overwriting ct original tuple for ICMPv6 X-BeenThere: ovs-dev@openvswitch.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: ovs-dev-bounces@openvswitch.org Sender: "dev" OVS_PACKET_CMD_EXECUTE has 3 main attributes: - OVS_PACKET_ATTR_KEY - Packet metadata in a netlink format. - OVS_PACKET_ATTR_PACKET - Binary packet content. - OVS_PACKET_ATTR_ACTIONS - Actions to execute on the packet. OVS_PACKET_ATTR_KEY is parsed first to populate sw_flow_key structure with the metadata like conntrack state, input port, recirculation id, etc. Then the packet itself gets parsed to populate the rest of the keys from the packet headers. Whenever the packet parsing code starts parsing the ICMPv6 header, it first zeroes out fields in the key corresponding to Neighbor Discovery information even if it is not an ND packet. It is an 'ipv6.nd' field. However, the 'ipv6' is a union that shares the space between 'nd' and 'ct_orig' that holds the original tuple conntrack metadata parsed from the OVS_PACKET_ATTR_KEY. ND packets should not normally have conntrack state, so it's fine to share the space, but normal ICMPv6 Echo packets or maybe other types of ICMPv6 can have the state attached and it should not be overwritten. The issue results in all but the last 4 bytes of the destination address being wiped from the original conntrack tuple leading to incorrect packet matching and potentially executing wrong actions in case this packet recirculates within the datapath or goes back to userspace. ND fields should not be accessed in non-ND packets, so not clearing them should be fine. Executing memset() only for actual ND packets to avoid the issue. Initializing the whole thing before parsing is needed because ND packet may not contain all the options. The issue only affects the OVS_PACKET_CMD_EXECUTE path and doesn't affect packets entering OVS datapath from network interfaces, because in this case CT metadata is populated from skb after the packet is already parsed. Fixes: 9dd7f8907c37 ("openvswitch: Add original direction conntrack tuple to sw_flow_key.") Reported-by: Antonin Bas Closes: https://github.com/openvswitch/ovs-issues/issues/327 Signed-off-by: Ilya Maximets Acked-by: Aaron Conole Acked-by: Eelco Chaudron --- Note: I'm working on a selftest for this issue, but it requires some ground work first to add support for OVS_PACKET_CMD_EXECUTE into opnevswitch selftests as well as parsing of ct tuples. So it is going to be a separate patch set. net/openvswitch/flow.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c index 33b21a0c0548..8a848ce72e29 100644 --- a/net/openvswitch/flow.c +++ b/net/openvswitch/flow.c @@ -561,7 +561,6 @@ static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key, */ key->tp.src = htons(icmp->icmp6_type); key->tp.dst = htons(icmp->icmp6_code); - memset(&key->ipv6.nd, 0, sizeof(key->ipv6.nd)); if (icmp->icmp6_code == 0 && (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION || @@ -570,6 +569,8 @@ static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key, struct nd_msg *nd; int offset; + memset(&key->ipv6.nd, 0, sizeof(key->ipv6.nd)); + /* In order to process neighbor discovery options, we need the * entire packet. */