From patchwork Mon Feb 21 20:19:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Alvin_=C5=A0ipraga?= X-Patchwork-Id: 12754106 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 A560CC433EF for ; Mon, 21 Feb 2022 20:19:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233573AbiBUUUO (ORCPT ); Mon, 21 Feb 2022 15:20:14 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:50486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231161AbiBUUUN (ORCPT ); Mon, 21 Feb 2022 15:20:13 -0500 Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A06717A87 for ; Mon, 21 Feb 2022 12:19:48 -0800 (PST) Received: by mail-wm1-x333.google.com with SMTP id i19so10138934wmq.5 for ; Mon, 21 Feb 2022 12:19:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pqrs.dk; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=bRYfBT7+YvPhgwvqbULWJpR1FaB2CXS8XAOJTniZzJ0=; b=Nz7JRt9+gUUEoCpSMIxeNgs57Qs4+F9d9kczEkKJqch+3gAyvgcOne8iEw4BzPftoK XjcO4rRzmjamT0awd61BrUHgXMUpj4CIz6YClD+E1MywZrQBZFam32NHBsyfsrnj/n/k bgPDTlHazLD5IYI1ujRemiD+wJRxRsGXZyHHw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=bRYfBT7+YvPhgwvqbULWJpR1FaB2CXS8XAOJTniZzJ0=; b=SZPS8bVUwTUsbx+xj9oU6wISmA00huVNLKprN5E0j0t7Bs4wXe97YPtoHa/PsZ3Up4 eBepxKdixMmCtIOlYJZMwQr3N9sowOPYkmyqiYUz2quoCYw+DqVYaFDpEjhOLuXPpFj4 YzF9Nhk26am0PHmAkCHf9Yz91W2iHKicZJrWx1fHeUnfBW6hpavG2+A60RP031cZuylO koHfE0NiB0L8or+9qfuumtkt6d+LWCJKAEGEZhSNoxvrlWmRXgyEnoZk8/IN6X13Z1/5 PCoILOII2LcffOg0DQh223QIiK9GUXgWxT/DZGajil4c7MPg14nInT+Q9ICHRPhfcAwE v8SQ== X-Gm-Message-State: AOAM533BmrO8oyYaSF+5gkiNR2gioFqUEu0be7oT6VYnuz5nOAPY10p/ mzrffaCeC04cubl6YCW226dryA== X-Google-Smtp-Source: ABdhPJzbyysYv4K2J8uCVgKrzj1ioT5n2LsRIQCL4yD0W/+uxQaHbGZWfESxpg+9QAk45WEAH23a3Q== X-Received: by 2002:a7b:c143:0:b0:37b:dacd:bf2f with SMTP id z3-20020a7bc143000000b0037bdacdbf2fmr565884wmi.16.1645474786592; Mon, 21 Feb 2022 12:19:46 -0800 (PST) Received: from capella.. (80.71.142.18.ipv4.parknet.dk. [80.71.142.18]) by smtp.gmail.com with ESMTPSA id o6-20020a05600c338600b0037c322d1425sm322567wmp.8.2022.02.21.12.19.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 21 Feb 2022 12:19:46 -0800 (PST) From: =?utf-8?q?Alvin_=C5=A0ipraga?= To: Andrew Lunn , Vivien Didelot , Florian Fainelli , Vladimir Oltean , "David S. Miller" , Jakub Kicinski , =?utf-8?q?Alvin_=C5=A0ipraga?= Cc: Vladimir Oltean , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net] net: dsa: fix panic when removing unoffloaded port from bridge Date: Mon, 21 Feb 2022 21:19:31 +0100 Message-Id: <20220221201931.296500-1-alvin@pqrs.dk> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Alvin Šipraga If a bridged port is not offloaded to the hardware - either because the underlying driver does not implement the port_bridge_{join,leave} ops, or because the operation failed - then its dp->bridge pointer will be NULL when dsa_port_bridge_leave() is called. Avoid dereferncing NULL. This fixes the following splat when removing a port from a bridge: Unable to handle kernel access to user memory outside uaccess routines at virtual address 0000000000000000 Internal error: Oops: 96000004 [#1] PREEMPT_RT SMP CPU: 3 PID: 1119 Comm: brctl Tainted: G O 5.17.0-rc4-rt4 #1 Call trace: dsa_port_bridge_leave+0x8c/0x1e4 dsa_slave_changeupper+0x40/0x170 dsa_slave_netdevice_event+0x494/0x4d4 notifier_call_chain+0x80/0xe0 raw_notifier_call_chain+0x1c/0x24 call_netdevice_notifiers_info+0x5c/0xac __netdev_upper_dev_unlink+0xa4/0x200 netdev_upper_dev_unlink+0x38/0x60 del_nbp+0x1b0/0x300 br_del_if+0x38/0x114 add_del_if+0x60/0xa0 br_ioctl_stub+0x128/0x2dc br_ioctl_call+0x68/0xb0 dev_ifsioc+0x390/0x554 dev_ioctl+0x128/0x400 sock_do_ioctl+0xb4/0xf4 sock_ioctl+0x12c/0x4e0 __arm64_sys_ioctl+0xa8/0xf0 invoke_syscall+0x4c/0x110 el0_svc_common.constprop.0+0x48/0xf0 do_el0_svc+0x28/0x84 el0_svc+0x1c/0x50 el0t_64_sync_handler+0xa8/0xb0 el0t_64_sync+0x17c/0x180 Code: f9402f00 f0002261 f9401302 913cc021 (a9401404) ---[ end trace 0000000000000000 ]--- Fixes: d3eed0e57d5d ("net: dsa: keep the bridge_dev and bridge_num as part of the same structure") Signed-off-by: Alvin Šipraga --- net/dsa/port.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/net/dsa/port.c b/net/dsa/port.c index eef4a98f2628..fc7a233653a0 100644 --- a/net/dsa/port.c +++ b/net/dsa/port.c @@ -395,10 +395,17 @@ void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br) .tree_index = dp->ds->dst->index, .sw_index = dp->ds->index, .port = dp->index, - .bridge = *dp->bridge, }; int err; + /* If the port could not be offloaded to begin with, then + * there is nothing to do. + */ + if (!dp->bridge) + return; + + info.bridge = *dp->bridge, + /* Here the port is already unbridged. Reflect the current configuration * so that drivers can program their chips accordingly. */