From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752671AbcEVTmo (ORCPT ); Sun, 22 May 2016 15:42:44 -0400 Received: from mail-lb0-f177.google.com ([209.85.217.177]:34079 "EHLO mail-lb0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752496AbcEVTmj (ORCPT ); Sun, 22 May 2016 15:42:39 -0400 Date: Sun, 22 May 2016 22:42:28 +0300 From: Max Filippov To: Colin King Cc: "David S . Miller" , Andrew Lunn , Florian Fainelli , Tobias Klauser , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net/ethoc: fix null dereference on error exit path Message-ID: <20160522194228.GA11011@octofox.metropolis> References: <1463944098-7061-1-git-send-email-colin.king@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1463944098-7061-1-git-send-email-colin.king@canonical.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Colin, On Sun, May 22, 2016 at 08:08:18PM +0100, Colin King wrote: > From: Colin Ian King > > priv is assigned to NULL however all the error exit paths to label 'free' > dereference priv, causing a null pointer dereference. > > Examination of the code shows that all error exits via the 'free' > label path occur before priv is assigned to netdev_priv(netdev), hence > there is no need to call clk_disable_unprepare and so the location of > the label should be moved to free_netdev statement to avoid this null > dereference on priv. This description is a bit inaccurate. Indeed all 'goto free' above the 'priv = netdev_priv(netdev);' need to skip 'if (priv->clk)' check, but there are two more 'goto free' below that line, and they look correct now, but after this patch they'll leave the clock enabled. -- Thanks. -- Max