From patchwork Tue Jun 29 14:06:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 469054 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28D24C11F66 for ; Tue, 29 Jun 2021 14:08:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0ED6361DC4 for ; Tue, 29 Jun 2021 14:08:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234302AbhF2OK3 (ORCPT ); Tue, 29 Jun 2021 10:10:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233843AbhF2OKH (ORCPT ); Tue, 29 Jun 2021 10:10:07 -0400 Received: from mail-ed1-x535.google.com (mail-ed1-x535.google.com [IPv6:2a00:1450:4864:20::535]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A38BC061226 for ; Tue, 29 Jun 2021 07:07:32 -0700 (PDT) Received: by mail-ed1-x535.google.com with SMTP id i5so31540005eds.1 for ; Tue, 29 Jun 2021 07:07:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=BOMzh8BvHskVBrXcwAoloE2yOIC+E69XRfT1jHkRC1Q=; b=fO/0/fnnnR63NQyNWELQzWLeqGg3F+vEXP6dbYjC8bNeQw7J3Bjmb4WxBhj3tjx/ns s2okUXZC6wkt2i96ClUKWd69J+f33i+V5l9LVv2nLe8JOUftGJVogTJTm/yD3rxp2Cn5 ZDLL26CuapdYY9r2iLrozwTnVHdLYy2+/4fSuJbUyfiitKny6iCdiXhvaa7TWAkXIWYM z0qgN4O/f+mQA0xQoEdZpDeuoMtLicmD3kENRvCOefpqnb/Wjt/ewL+AhLGjpbDCuY0v bxkBsWzh1s84j/IQZaKo//A7+yM6sQxdx5DQKIMpGlzQRF6tiaeZ/BPjFUJni0X9D4IH mSiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=BOMzh8BvHskVBrXcwAoloE2yOIC+E69XRfT1jHkRC1Q=; b=rL+2d7IopjVxIAVJysyRpBQYj5+ZM87O3qITJefFVSocb4PNOsg6XqLcFqhIptj//V LqpflAQRddZnk1BcPoC068PYm19NVMgyU7wb9a4pWjMNcwntkprUa3qEWzLoN/hZuQS6 1FzGSTIgJne5rfNOPkKWXQrq7w8rEwzB2lMVOIopuOcgsIk+2gcFR0zk33Go13yjmtgI PawY5IZNvHry81hffxgp1zV0/0m6cQ/WPYDWP8I2U+kh/eycYaybh2Lk9SQcT2gfvJuL 6SaIn3xvQQ0FNXZcA+jOwn/gcjRIO5ADNx9Ip1R2xMAoYBNcjWU1Zk2auR/W/kW59k4Y DLQQ== X-Gm-Message-State: AOAM532jTsU2PbtczZlde894IFP8sjRgMF7xnkarCWg16CegRpijOS2m GsmWdmicZ8fuLI8RlfuS+09Y1m1RHwE= X-Google-Smtp-Source: ABdhPJxodBWegIv9JxWdAxD3DDeD8A6DYVxOsxaHi9l21ZpnZLIkC/D/5eejp45sFGwnHFlrcqFvww== X-Received: by 2002:aa7:d78b:: with SMTP id s11mr5813879edq.280.1624975651063; Tue, 29 Jun 2021 07:07:31 -0700 (PDT) Received: from localhost.localdomain ([188.26.224.68]) by smtp.gmail.com with ESMTPSA id b27sm8220121ejl.10.2021.06.29.07.07.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Jun 2021 07:07:30 -0700 (PDT) From: Vladimir Oltean To: netdev@vger.kernel.org, Jakub Kicinski , "David S. Miller" Cc: Andrew Lunn , Florian Fainelli , Vivien Didelot , Jiri Pirko , Ido Schimmel , Tobias Waldekranz , Roopa Prabhu , Nikolay Aleksandrov , bridge@lists.linux-foundation.org, Vladimir Oltean Subject: [PATCH v5 net-next 14/15] net: dsa: ensure during dsa_fdb_offload_notify that dev_hold and dev_put are on the same dev Date: Tue, 29 Jun 2021 17:06:57 +0300 Message-Id: <20210629140658.2510288-15-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210629140658.2510288-1-olteanv@gmail.com> References: <20210629140658.2510288-1-olteanv@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Vladimir Oltean When (a) "dev" is a bridge port which the DSA switch tree offloads, but is otherwise not a dsa slave (such as a LAG netdev), or (b) "dev" is the bridge net device itself then strange things happen to the dev_hold/dev_put pair: dsa_schedule_work() will still be called with a DSA port that offloads that netdev, but dev_hold() will be called on the non-DSA netdev. Then the "if" condition in dsa_slave_switchdev_event_work() does not pass, because "dev" is not a DSA netdev, so dev_put() is not called. This results in the simple fact that we have a reference counting mismatch on the "dev" net device. This can be seen when we add support for host addresses installed on the bridge net device. ip link add br1 type bridge ip link set br1 address 00:01:02:03:04:05 ip link set swp0 master br1 ip link del br1 [ 968.512278] unregister_netdevice: waiting for br1 to become free. Usage count = 5 It seems foolish to do penny pinching and not add the net_device pointer in the dsa_switchdev_event_work structure, so let's finally do that. As an added bonus, when we start offloading local entries pointing towards the bridge, these will now properly appear as 'offloaded' in 'bridge fdb' (this was not possible before, because 'dev' was assumed to only be a DSA net device): 00:01:02:03:04:05 dev br0 vlan 1 offload master br0 permanent 00:01:02:03:04:05 dev br0 offload master br0 permanent Signed-off-by: Vladimir Oltean --- v4->v5: none net/dsa/dsa_priv.h | 1 + net/dsa/slave.c | 9 ++++----- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h index 36e667ea94db..f201c33980bf 100644 --- a/net/dsa/dsa_priv.h +++ b/net/dsa/dsa_priv.h @@ -116,6 +116,7 @@ struct dsa_notifier_mrp_ring_role_info { struct dsa_switchdev_event_work { struct dsa_switch *ds; int port; + struct net_device *dev; struct work_struct work; unsigned long event; /* Specific for SWITCHDEV_FDB_ADD_TO_DEVICE and diff --git a/net/dsa/slave.c b/net/dsa/slave.c index a7b5d2a41472..ffbba1e71551 100644 --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -2349,9 +2349,8 @@ static void dsa_slave_switchdev_event_work(struct work_struct *work) } rtnl_unlock(); + dev_put(switchdev_work->dev); kfree(switchdev_work); - if (dsa_is_user_port(ds, dp->index)) - dev_put(dp->slave); } static int dsa_lower_dev_walk(struct net_device *lower_dev, @@ -2469,15 +2468,15 @@ static int dsa_slave_switchdev_event(struct notifier_block *unused, switchdev_work->ds = dp->ds; switchdev_work->port = dp->index; switchdev_work->event = event; + switchdev_work->dev = dev; ether_addr_copy(switchdev_work->addr, fdb_info->addr); switchdev_work->vid = fdb_info->vid; switchdev_work->host_addr = host_addr; - /* Hold a reference on the slave for dsa_fdb_offload_notify */ - if (dsa_is_user_port(dp->ds, dp->index)) - dev_hold(dev); + /* Hold a reference for dsa_fdb_offload_notify */ + dev_hold(dev); dsa_schedule_work(&switchdev_work->work); break; default: