From mboxrd@z Thu Jan 1 00:00:00 1970 From: Colin Ian King Subject: Re: [PATCH] net/ethoc: fix null dereference on error exit path Date: Sun, 22 May 2016 22:20:21 +0100 Message-ID: <57422295.4050007@canonical.com> References: <1463944098-7061-1-git-send-email-colin.king@canonical.com> <20160522194228.GA11011@octofox.metropolis> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: "David S . Miller" , Andrew Lunn , Florian Fainelli , Tobias Klauser , netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Max Filippov Return-path: In-Reply-To: <20160522194228.GA11011@octofox.metropolis> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 22/05/16 20:42, Max Filippov wrote: > 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. > Oops, I'll resend a corrected fix tomorrow