From patchwork Mon Jun 28 22:00:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 468613 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=-15.7 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, URIBL_BLOCKED, 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 42035C11F65 for ; Mon, 28 Jun 2021 22:01:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 21C3761D00 for ; Mon, 28 Jun 2021 22:01:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238174AbhF1WEU (ORCPT ); Mon, 28 Jun 2021 18:04:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237227AbhF1WDQ (ORCPT ); Mon, 28 Jun 2021 18:03:16 -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 40F94C061760 for ; Mon, 28 Jun 2021 15:00:49 -0700 (PDT) Received: by mail-ed1-x535.google.com with SMTP id i5so28292200eds.1 for ; Mon, 28 Jun 2021 15:00:49 -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=J+t92kp2whfwaiecVe0FC6ct75iFu1mJ1vcqnv+uoxE=; b=n7+5JydTIYxLF/EALFinDyMia+4cL3sRl4to8Lt5fh9aptKuRp8p0+46NCVbpzAFZq cKSgTmNxFNLxUVn78xx3op2GULefD8dqmz9Guobq5TPJIuYdQhH7masm7ZSWQ1z8TAUX +vRi7FAMphlaZHv6SwWQkJaTo7IhuMB3o+JmfIId7Hww5jxza4IEYyJLHJA+55KjMnb/ QR+T+Z50aF0pATA9/Wp5sUvzLUgCSa7rK5mtup2er5Rp+bHQx2BQWQO4HuyqPlB3/HX/ tqD6GJPN+CkN49mjnKSBwkGDuv68RutU+Fq6DdN8btXO8Fa1Jl+I2yBHjrYj+nDETJxj LUfQ== 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=J+t92kp2whfwaiecVe0FC6ct75iFu1mJ1vcqnv+uoxE=; b=uXTRJTpNDvAj5H29KZF4a5bYeM5UvSwVtv0PHeg7GRx4w4IX2ZV2m39UeBf0w53OR8 T7nnu8sS2wEyA/AI9HXaJ3a/eHP7OsXKtgjALPiCowApp86eLiVj19ORb/xDQm2YsAzj Lp0eSpKxsCqadcsIYryHnEAGZlQH8wdAeHkXACscbyz4/NlFmPf+lX8MWZ0MlU17qEcM pawciNS3BSuYFghA68DYHInva9B1L4UB9zxPplrJ++5n1ZeW0IYbuL1EKjc1m7tiovyP v5lUh1QsK2Qd7plHaXjquZoDYX1PgyDXuhnUz0k6FpGkK5bcb4t+F75LT1zafGGqWies n8IQ== X-Gm-Message-State: AOAM532WjERtGSSQKOjDV/CYplRezoriJvDc61VfMdjjPcgeZmdiJWKT d0K6F4J2mXB/UAx7qmu7l+5pA7wYwDM= X-Google-Smtp-Source: ABdhPJwzBMKOO8OBrSlrLHfcRVpxR62ORqi9hXpeRYsTfsX34VtUG2xww0C/htUgLiBmWXGSUvCv2A== X-Received: by 2002:a05:6402:34c1:: with SMTP id w1mr29612730edc.104.1624917647766; Mon, 28 Jun 2021 15:00:47 -0700 (PDT) Received: from localhost.localdomain ([188.26.224.68]) by smtp.gmail.com with ESMTPSA id dn7sm10146615edb.29.2021.06.28.15.00.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Jun 2021 15:00:47 -0700 (PDT) From: Vladimir Oltean To: netdev@vger.kernel.org Cc: Andrew Lunn , Florian Fainelli , Vivien Didelot , Jiri Pirko , Ido Schimmel , Tobias Waldekranz , Roopa Prabhu , Nikolay Aleksandrov , Vladimir Oltean Subject: [PATCH v4 net-next 13/14] net: dsa: ensure during dsa_fdb_offload_notify that dev_hold and dev_put are on the same dev Date: Tue, 29 Jun 2021 01:00:10 +0300 Message-Id: <20210628220011.1910096-14-olteanv@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210628220011.1910096-1-olteanv@gmail.com> References: <20210628220011.1910096-1-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 --- 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: