From mboxrd@z Thu Jan 1 00:00:00 1970 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 2A717CCA48D for ; Wed, 8 Jun 2022 01:29:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1385748AbiFHB0O (ORCPT ); Tue, 7 Jun 2022 21:26:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45910 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1383219AbiFGVwq (ORCPT ); Tue, 7 Jun 2022 17:52:46 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A11862431A2; Tue, 7 Jun 2022 12:10:44 -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 ams.source.kernel.org (Postfix) with ESMTPS id 2712CB823B1; Tue, 7 Jun 2022 19:10:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70CF6C385A2; Tue, 7 Jun 2022 19:10:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654629041; bh=EbUndU5aN6FSHQ/Au1vWjV4N7TDNpgYntN0GGYXZbew=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XviRhwEdy0Ut62+yizNm7QJAck2dpDv4TV+1aZMiYJvr5HpEPs+BjeYb9GJ+xEV6s s1pDVfxENANqpjmasRw8pSFus4P7iOdl6EAUNMgfCn8rUwaTp+Y9jF2zxkmGTaTCju b7OFMXH247njx33DlEHJxowJUjzxMToCaG5q3H8Y= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+92beb3d46aab498710fa@syzkaller.appspotmail.com, Vladimir Oltean , Jakub Kicinski , Hangbin Liu , Sasha Levin Subject: [PATCH 5.18 507/879] bonding: fix missed rcu protection Date: Tue, 7 Jun 2022 19:00:25 +0200 Message-Id: <20220607165017.592202504@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607165002.659942637@linuxfoundation.org> References: <20220607165002.659942637@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hangbin Liu [ Upstream commit 9b80ccda233fa6c59de411bf889cc4d0e028f2c7 ] 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 Link: https://lore.kernel.org/r/20220519020148.1058344-1-liuhangbin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- 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 = { -- 2.35.1