Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756844AbcLPBSc (ORCPT ); Thu, 15 Dec 2016 20:18:32 -0500 Received: from out3-smtp.messagingengine.com ([66.111.4.27]:49190 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753132AbcLPBSZ (ORCPT ); Thu, 15 Dec 2016 20:18:25 -0500 X-ME-Sender: X-Sasl-enc: wimgCIzoFBkOyKyVpLWZqV3ecU3/OaB39OIOfnCjSO7U 1481851103 Date: Thu, 15 Dec 2016 18:18:23 -0700 From: Mark Greer To: Geoff Lansberry Cc: linux-wireless@vger.kernel.org, lauro.venancio@openbossa.org, aloisio.almeida@openbossa.org, sameo@linux.intel.com, robh+dt@kernel.org, mark.rutland@arm.com, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, justin@kuvee.com, Jaret Cantu Subject: Re: [PATCH 3/3] nfc: trf7970a: Prevent repeated polling from crashing the kernel Message-ID: <20161216011823.GC25227@animalcreek.com> References: <1481841044-4314-1-git-send-email-glansberry@gmail.com> <1481841044-4314-3-git-send-email-glansberry@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1481841044-4314-3-git-send-email-glansberry@gmail.com> Organization: Animal Creek Technologies, Inc. User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 531 Lines: 19 On Thu, Dec 15, 2016 at 05:30:44PM -0500, Geoff Lansberry wrote: > From: Jaret Cantu > > Repeated polling attempts cause a NULL dereference error to occur. > This is because the curent state of the trf7970a is reading but > a request has been made to send a command. > > The solution is to properly kill the waiting reading (workqueue) > before failing on the send. Maybe its just me but I find this description a little hard to grok. Mind reworking it? The patch itself looks fine. Thanks, Mark --