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 X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 D97CEC2D0A3 for ; Sun, 1 Nov 2020 22:36:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 955BE2225B for ; Sun, 1 Nov 2020 22:36:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727397AbgKAWf7 (ORCPT ); Sun, 1 Nov 2020 17:35:59 -0500 Received: from 95-31-39-132.broadband.corbina.ru ([95.31.39.132]:56408 "EHLO blackbox.su" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727081AbgKAWf6 (ORCPT ); Sun, 1 Nov 2020 17:35:58 -0500 Received: from metamini.metanet (metamini.metanet [192.168.2.5]) by blackbox.su (Postfix) with ESMTP id 20A2882D0D; Mon, 2 Nov 2020 01:35:59 +0300 (MSK) From: Sergej Bauer Cc: andrew@lunn.ch, Markus.Elfring@web.de, sbauer@blackbox.su, Bryan Whitehead , Microchip Linux Driver Support , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] lan743x: fix for potential NULL pointer dereference with bare card Date: Mon, 2 Nov 2020 01:35:55 +0300 Message-Id: <20201101223556.16116-1-sbauer@blackbox.su> X-Mailer: git-send-email 2.20.1 In-Reply-To: <220201101203820.GD1109407@lunn.ch> References: <220201101203820.GD1109407@lunn.ch> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is the 3rd revision of the patch fix for potential null pointer dereference with lan743x card. The simpliest way to reproduce: boot with bare lan743x and issue "ethtool ethN" commant where ethN is the interface with lan743x card. Example: $ sudo ethtool eth7 dmesg: [ 103.510336] BUG: kernel NULL pointer dereference, address: 0000000000000340 ... [ 103.510836] RIP: 0010:phy_ethtool_get_wol+0x5/0x30 [libphy] ... [ 103.511629] Call Trace: [ 103.511666] lan743x_ethtool_get_wol+0x21/0x40 [lan743x] [ 103.511724] dev_ethtool+0x1507/0x29d0 [ 103.511769] ? avc_has_extended_perms+0x17f/0x440 [ 103.511820] ? tomoyo_init_request_info+0x84/0x90 [ 103.511870] ? tomoyo_path_number_perm+0x68/0x1e0 [ 103.511919] ? tty_insert_flip_string_fixed_flag+0x82/0xe0 [ 103.511973] ? inet_ioctl+0x187/0x1d0 [ 103.512016] dev_ioctl+0xb5/0x560 [ 103.512055] sock_do_ioctl+0xa0/0x140 [ 103.512098] sock_ioctl+0x2cb/0x3c0 [ 103.512139] __x64_sys_ioctl+0x84/0xc0 [ 103.512183] do_syscall_64+0x33/0x80 [ 103.512224] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 103.512274] RIP: 0033:0x7f54a9cba427 ... Previous versions can be found at: v1: initial version https://lkml.org/lkml/2020/10/28/921 v2: do not return from lan743x_ethtool_set_wol if netdev->phydev == NULL, just skip the call of phy_ethtool_set_wol() instead. https://lkml.org/lkml/2020/10/31/380 v3: in function lan743x_ethtool_set_wol: use ternary operator instead of if-else sentence (review by Markus Elfring) return -ENETDOWN insted of -EIO (review by Andrew Lunn) Signed-off-by: Sergej Bauer --- diff --git a/drivers/net/ethernet/microchip/lan743x_ethtool.c b/drivers/net/ethernet/microchip/lan743x_ethtool.c index dcde496da7fb..c5de8f46cdd3 100644 --- a/drivers/net/ethernet/microchip/lan743x_ethtool.c +++ b/drivers/net/ethernet/microchip/lan743x_ethtool.c @@ -780,7 +780,9 @@ static void lan743x_ethtool_get_wol(struct net_device *netdev, wol->supported = 0; wol->wolopts = 0; - phy_ethtool_get_wol(netdev->phydev, wol); + + if (netdev->phydev) + phy_ethtool_get_wol(netdev->phydev, wol); wol->supported |= WAKE_BCAST | WAKE_UCAST | WAKE_MCAST | WAKE_MAGIC | WAKE_PHY | WAKE_ARP; @@ -809,9 +811,8 @@ static int lan743x_ethtool_set_wol(struct net_device *netdev, device_set_wakeup_enable(&adapter->pdev->dev, (bool)wol->wolopts); - phy_ethtool_set_wol(netdev->phydev, wol); - - return 0; + return netdev->phydev ? phy_ethtool_set_wol(netdev->phydev, wol) + : -ENETDOWN; } #endif /* CONFIG_PM */