From nobody Sat May 10 06:29:17 2025 Delivered-To: importer2@patchew.org Received-SPF: pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; envelope-from=linux-kernel-owner@vger.kernel.org; helo=vger.kernel.org; Received-SPF: pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; envelope-from=linux-kernel-owner@vger.kernel.org; helo=vger.kernel.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail(p=quarantine dis=quarantine) header.from=blackbox.su ARC-Seal: i=1; a=rsa-sha256; t=1604270169; cv=none; d=zohomail.com; s=zohoarc; b=BeF9K9ihevRRTgKOf3SRTKOUY1mdfvlZ+5/PbXyFq+a7xoCTAxMea47ki9PTmBqvZdstsOJhlsRZNIpwXARciwnJOD7D3NxHks/mWCE4eIjUnnJ2l1Yo3GY9yRYuuegfIZJdrRGOJvF0GsyI8edT26kprbAdfHkAHqO+83kATEo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1604270169; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Id:MIME-Version:Message-ID:References:Subject:To; bh=PXj7EDBkGUAfN8r9ZP4uXfeieXhVOfdaG4Puv5kZGgQ=; b=G/cwFC/DLpLJ5x853xHzz2xj9MdYCVepYpX8Vbs2tK8Ynv/H6NuhuoKpWrl+aSvs31gMushByThMAnewbByhwHUqC/7QPysr04+5VPP5TMWJeRlXmBIJ+iEI5r9EgQjhfyM3gWXEWz0NUA/aTyBZKwSx21se0Bhxf3C2n5r7D8U= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail header.from= (p=quarantine dis=quarantine) header.from= Return-Path: Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mx.zohomail.com with SMTP id 1604270169760490.1720904014404; Sun, 1 Nov 2020 14:36:09 -0800 (PST) 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: quoted-printable To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This is the 3rd revision of the patch fix for potential null pointer derefe= rence with lan743x card. The simpliest way to reproduce: boot with bare lan743x and issue "ethtool e= thN" commant where ethN is the interface with lan743x card. Example: $ sudo ethtool eth7 dmesg: [ 103.510336] BUG: kernel NULL pointer dereference, address: 0000000000000= 340 ... [ 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 =3D=3D NULL, j= ust 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, =20 wol->supported =3D 0; wol->wolopts =3D 0; - phy_ethtool_get_wol(netdev->phydev, wol); + + if (netdev->phydev) + phy_ethtool_get_wol(netdev->phydev, wol); =20 wol->supported |=3D 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 *n= etdev, =20 device_set_wakeup_enable(&adapter->pdev->dev, (bool)wol->wolopts); =20 - phy_ethtool_set_wol(netdev->phydev, wol); - - return 0; + return netdev->phydev ? phy_ethtool_set_wol(netdev->phydev, wol) + : -ENETDOWN; } #endif /* CONFIG_PM */ =20