From nobody Sun Feb 8 21:46:36 2026 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 C2FECC46467 for ; Mon, 23 May 2022 17:43:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243570AbiEWRmK (ORCPT ); Mon, 23 May 2022 13:42:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242535AbiEWR1r (ORCPT ); Mon, 23 May 2022 13:27:47 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF18C7DE24; Mon, 23 May 2022 10:23:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E1AEA61528; Mon, 23 May 2022 17:14:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E56A6C385A9; Mon, 23 May 2022 17:14:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1653326063; bh=jaBttUhe7e1U2JTkC+nmJw+Yb1tL2Jbpq5RqVccsWhI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=v8h7DVmrS1od2xGP6DjxwyiwJqwSaEeIdcjYTQGGVsshvtkC8skVoyU2Vy03kd2vG q0pM7s/3aqcmm4HcI38clEHGemhrmnYtJuJpg8UO7oHJfzlZOGSRnBU+gQCE1LwAEC cLHRqMbmVhAXJRC0kRjUpP1fNNDg5+UD5I2in8vw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrew Lunn , Ido Schimmel , Nikolay Aleksandrov , Paolo Abeni , Sasha Levin Subject: [PATCH 5.4 49/68] net: bridge: Clear offload_fwd_mark when passing frame up bridge interface. Date: Mon, 23 May 2022 19:05:16 +0200 Message-Id: <20220523165810.648913035@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220523165802.500642349@linuxfoundation.org> References: <20220523165802.500642349@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Andrew Lunn [ Upstream commit fbb3abdf2223cd0dfc07de85fe5a43ba7f435bdf ] It is possible to stack bridges on top of each other. Consider the following which makes use of an Ethernet switch: br1 / \ / \ / \ br0.11 wlan0 | br0 / | \ p1 p2 p3 br0 is offloaded to the switch. Above br0 is a vlan interface, for vlan 11. This vlan interface is then a slave of br1. br1 also has a wireless interface as a slave. This setup trunks wireless lan traffic over the copper network inside a VLAN. A frame received on p1 which is passed up to the bridge has the skb->offload_fwd_mark flag set to true, indicating that the switch has dealt with forwarding the frame out ports p2 and p3 as needed. This flag instructs the software bridge it does not need to pass the frame back down again. However, the flag is not getting reset when the frame is passed upwards. As a result br1 sees the flag, wrongly interprets it, and fails to forward the frame to wlan0. When passing a frame upwards, clear the flag. This is the Rx equivalent of br_switchdev_frame_unmark() in br_dev_xmit(). Fixes: f1c2eddf4cb6 ("bridge: switchdev: Use an helper to clear forward mar= k") Signed-off-by: Andrew Lunn Reviewed-by: Ido Schimmel Tested-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/20220518005840.771575-1-andrew@lunn.ch Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/bridge/br_input.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 09b1dd8cd853..464f6a619444 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -42,6 +42,13 @@ static int br_pass_frame_up(struct sk_buff *skb) u64_stats_update_end(&brstats->syncp); =20 vg =3D br_vlan_group_rcu(br); + + /* Reset the offload_fwd_mark because there could be a stacked + * bridge above, and it should not think this bridge it doing + * that bridge's work forwarding out its ports. + */ + br_switchdev_frame_unmark(skb); + /* Bridge is just like any other port. Make sure the * packet is allowed except in promisc modue when someone * may be running packet capture. --=20 2.35.1