From patchwork Thu May 19 02:01:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hangbin Liu X-Patchwork-Id: 12854454 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 23A29C433F5 for ; Thu, 19 May 2022 02:02:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232635AbiESCCH (ORCPT ); Wed, 18 May 2022 22:02:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229702AbiESCCF (ORCPT ); Wed, 18 May 2022 22:02:05 -0400 Received: from mail-pf1-x431.google.com (mail-pf1-x431.google.com [IPv6:2607:f8b0:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BCEB488B3 for ; Wed, 18 May 2022 19:02:04 -0700 (PDT) Received: by mail-pf1-x431.google.com with SMTP id x143so3798855pfc.11 for ; Wed, 18 May 2022 19:02:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=mixIM/X9SqDqcozkIvhX3jb18PG1z7mGFG3QeoXd6QQ=; b=foX4lGMsp8Qkvucb3dFYKfFKOcFlzIrj3/SUl2oUryso52aRYNIs/zFMWvCYglULem MFXE2EkKQtgQ0T2L5HW9yXzRJYZIiAL6h0WAPRzCdkRPFeOLnWCesdD1ryGw8nSkauBO SpTURtcGWoKiK4k4eup9fIpLHbeo5ubjvpJhZjbt8VyXkC4VyGH3urivA2gFrevJh9wu L6LHp0Xo7i8F87lNh6IApmW/llZjH7GHRe6tO3kZ4W1stnp/VzUcKiypUxye+s65R2NO C+nyBTxI/uxKUOAR0qRC8eXSutTh1UK4xnzTmBRd2toXCg8oDDshrqxldqpVvcOv+Q7L L2GQ== 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=mixIM/X9SqDqcozkIvhX3jb18PG1z7mGFG3QeoXd6QQ=; b=nOgNmiN0aJqyfLTgIyCbNokQS9FC7EUGQQBU3UMj91xaJxZNmQJmRr+9BTaCDLb5l7 VSHVRKdzR7q09PJG7bOm0miyHKVhDIS56grsC6wuTp91CW/xU2ibS5wzIXym13o+uX2D rvVTtTcWZuSaFtwuYpc5qStnLY3RUY4jABMjmB4EW6Ex9HTFEQsRer1eelkByEo/5J2c TbN89hRdsWCuax/Q1cnpWHXg5PNG/n4j2hy1e/HANoPmlzqOobNdlEamyMxqgmeWWD/Z mPjvXVCtlXsq6QMAah0wUG0gKT94JvG+lb+pQWnPGHSqVg78iFASifjy6Az7DGLChAcr zlwA== X-Gm-Message-State: AOAM5304MC0gx14tw4f7J3aCSLJjIiv4m5jf5czcWLBplf8nxH2oKW77 Gc3e8Af6zkoFysB0n050g2iT90cVTIBW9A== X-Google-Smtp-Source: ABdhPJwbJjgT+DqXnbl7MzZMkAMBDLC6j3Ji7TDO3CRx+ci7ejAIaqTF2jTMMjcSf1Obep7B5ufRDQ== X-Received: by 2002:a63:6846:0:b0:3c6:cb42:cdb2 with SMTP id d67-20020a636846000000b003c6cb42cdb2mr1940020pgc.511.1652925723466; Wed, 18 May 2022 19:02:03 -0700 (PDT) Received: from Laptop-X1.redhat.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id z7-20020a655a47000000b003c67e472338sm2181215pgs.42.2022.05.18.19.01.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 May 2022 19:02:02 -0700 (PDT) From: Hangbin Liu To: netdev@vger.kernel.org Cc: Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , "David S . Miller" , Jakub Kicinski , David Ahern , Jonathan Toppins , Eric Dumazet , Paolo Abeni , Hangbin Liu , syzbot+92beb3d46aab498710fa@syzkaller.appspotmail.com, Vladimir Oltean Subject: [PATCHv3 net] bonding: fix missed rcu protection Date: Thu, 19 May 2022 10:01:48 +0800 Message-Id: <20220519020148.1058344-1-liuhangbin@gmail.com> 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 When removing the rcu_read_lock in bond_ethtool_get_ts_info() as discussed [1], I didn't notice it could be called via setsockopt, which doesn't hold rcu lock, as syzbot pointed: stack backtrace: CPU: 0 PID: 3599 Comm: syz-executor317 Not tainted 5.18.0-rc5-syzkaller-01392-g01f4685797a5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 bond_option_active_slave_get_rcu include/net/bonding.h:353 [inline] bond_ethtool_get_ts_info+0x32c/0x3a0 drivers/net/bonding/bond_main.c:5595 __ethtool_get_ts_info+0x173/0x240 net/ethtool/common.c:554 ethtool_get_phc_vclocks+0x99/0x110 net/ethtool/common.c:568 sock_timestamping_bind_phc net/core/sock.c:869 [inline] sock_set_timestamping+0x3a3/0x7e0 net/core/sock.c:916 sock_setsockopt+0x543/0x2ec0 net/core/sock.c:1221 __sys_setsockopt+0x55e/0x6a0 net/socket.c:2223 __do_sys_setsockopt net/socket.c:2238 [inline] __se_sys_setsockopt net/socket.c:2235 [inline] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2235 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f8902c8eb39 Fix it by adding rcu_read_lock and take a ref on the real_dev. Since dev_hold() and dev_put() can take NULL these days, we can skip checking if real_dev exist. [1] https://lore.kernel.org/netdev/27565.1642742439@famine/ Reported-by: syzbot+92beb3d46aab498710fa@syzkaller.appspotmail.com Fixes: aa6034678e87 ("bonding: use rcu_dereference_rtnl when get bonding active slave") Suggested-by: Vladimir Oltean Suggested-by: Jakub Kicinski Signed-off-by: Hangbin Liu Reviewed-by: Vladimir Oltean --- v3: skip checking if real_dev exist since dev_hold/put could take NULL. v2: add ref on the real_dev as Jakub and Paolo suggested. --- drivers/net/bonding/bond_main.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 38e152548126..b5c5196e03ee 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -5591,16 +5591,23 @@ static int bond_ethtool_get_ts_info(struct net_device *bond_dev, const struct ethtool_ops *ops; struct net_device *real_dev; struct phy_device *phydev; + int ret = 0; + rcu_read_lock(); real_dev = bond_option_active_slave_get_rcu(bond); + dev_hold(real_dev); + rcu_read_unlock(); + if (real_dev) { ops = real_dev->ethtool_ops; phydev = real_dev->phydev; if (phy_has_tsinfo(phydev)) { - return phy_ts_info(phydev, info); + ret = phy_ts_info(phydev, info); + goto out; } else if (ops->get_ts_info) { - return ops->get_ts_info(real_dev, info); + ret = ops->get_ts_info(real_dev, info); + goto out; } } @@ -5608,7 +5615,9 @@ static int bond_ethtool_get_ts_info(struct net_device *bond_dev, SOF_TIMESTAMPING_SOFTWARE; info->phc_index = -1; - return 0; +out: + dev_put(real_dev); + return ret; } static const struct ethtool_ops bond_ethtool_ops = {