From patchwork Wed Jun 8 09:19:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrea Mayer X-Patchwork-Id: 12873129 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F02FC43334 for ; Wed, 8 Jun 2022 09:52:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235308AbiFHJw2 (ORCPT ); Wed, 8 Jun 2022 05:52:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235545AbiFHJwO (ORCPT ); Wed, 8 Jun 2022 05:52:14 -0400 Received: from smtp.uniroma2.it (smtp.uniroma2.it [160.80.6.16]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5137B40FD2F; Wed, 8 Jun 2022 02:22:23 -0700 (PDT) Received: from localhost.localdomain ([160.80.103.126]) by smtp-2015.uniroma2.it (8.14.4/8.14.4/Debian-8) with ESMTP id 2589Jjp3001157 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Wed, 8 Jun 2022 11:19:45 +0200 From: Andrea Mayer To: "David S. Miller" , Hideaki YOSHIFUJI , David Ahern , Eric Dumazet , Jakub Kicinski , Paolo Abeni , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: Stefano Salsano , Paolo Lungaroni , Ahmed Abdelsalam , Andrea Mayer , Anton Makarov Subject: [net] net: seg6: fix seg6_lookup_any_nexthop() to handle VRFs using flowi_l3mdev Date: Wed, 8 Jun 2022 11:19:17 +0200 Message-Id: <20220608091917.20345-1-andrea.mayer@uniroma2.it> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.100.0 at smtp-2015 X-Virus-Status: Clean Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Commit 40867d74c374 ("net: Add l3mdev index to flow struct and avoid oif reset for port devices") adds a new entry (flowi_l3mdev) in the common flow struct used for indicating the l3mdev index for later rule and table matching. The l3mdev_update_flow() has been adapted to properly set the flowi_l3mdev based on the flowi_oif/flowi_iif. In fact, when a valid flowi_iif is supplied to the l3mdev_update_flow(), this function can update the flowi_l3mdev entry only if it has not yet been set (i.e., the flowi_l3mdev entry is equal to 0). The SRv6 End.DT6 behavior in VRF mode leverages a VRF device in order to force the routing lookup into the associated routing table. This routing operation is performed by seg6_lookup_any_nextop() preparing a flowi6 data structure used by ip6_route_input_lookup() which, in turn, (indirectly) invokes l3mdev_update_flow(). However, seg6_lookup_any_nexthop() does not initialize the new flowi_l3mdev entry which is filled with random garbage data. This prevents l3mdev_update_flow() from properly updating the flowi_l3mdev with the VRF index, and thus SRv6 End.DT6 (VRF mode)/DT46 behaviors are broken. This patch correctly initializes the flowi6 instance allocated and used by seg6_lookup_any_nexhtop(). Specifically, the entire flowi6 instance is wiped out: in case new entries are added to flowi/flowi6 (as happened with the flowi_l3mdev entry), we should no longer have incorrectly initialized values. As a result of this operation, the value of flowi_l3mdev is also set to 0. The proposed fix can be tested easily. Starting from the commit referenced in the Fixes, selftests [1],[2] indicate that the SRv6 End.DT6 (VRF mode)/DT46 behaviors no longer work correctly. By applying this patch, those behaviors are back to work properly again. [1] - tools/testing/selftests/net/srv6_end_dt46_l3vpn_test.sh [2] - tools/testing/selftests/net/srv6_end_dt6_l3vpn_test.sh Fixes: 40867d74c374 ("net: Add l3mdev index to flow struct and avoid oif reset for port devices") Reported-by: Anton Makarov Signed-off-by: Andrea Mayer Reviewed-by: David Ahern --- net/ipv6/seg6_local.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c index 9fbe243a0e81..98a34287439c 100644 --- a/net/ipv6/seg6_local.c +++ b/net/ipv6/seg6_local.c @@ -218,6 +218,7 @@ seg6_lookup_any_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, struct flowi6 fl6; int dev_flags = 0; + memset(&fl6, 0, sizeof(fl6)); fl6.flowi6_iif = skb->dev->ifindex; fl6.daddr = nhaddr ? *nhaddr : hdr->daddr; fl6.saddr = hdr->saddr;