From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751773AbdAYNnB (ORCPT ); Wed, 25 Jan 2017 08:43:01 -0500 Received: from mx2.suse.de ([195.135.220.15]:59065 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751595AbdAYNnA (ORCPT ); Wed, 25 Jan 2017 08:43:00 -0500 Date: Wed, 25 Jan 2017 14:42:50 +0100 From: "Luis R. Rodriguez" To: "Luis R. Rodriguez" Cc: Greg KH , ming.lei@canonical.com, keescook@chromium.org, linux-kernel-dev@beckhoff.com, jakub.kicinski@netronome.com, chris@chris-wilson.co.uk, oss-drivers@netronome.com, johannes@sipsolutions.net, j@w1.fi, teg@jklm.no, kay@vrfy.org, jwboyer@fedoraproject.org, dmitry.torokhov@gmail.com, seth.forshee@canonical.com, bjorn.andersson@linaro.org, linux-kernel@vger.kernel.org, wagi@monom.org, stephen.boyd@linaro.org, zohar@linux.vnet.ibm.com, tiwai@suse.de, dwmw2@infradead.org, fengguang.wu@intel.com, dhowells@redhat.com, arend.vanspriel@broadcom.com, kvalo@codeaurora.org, "[3.10+]" Subject: Re: [PATCH 7/7] firmware: firmware: fix NULL pointer dereference in __fw_load_abort() Message-ID: <20170125134250.GQ13946@wotan.suse.de> References: <20170118200141.GH13946@wotan.suse.de> <20170123161111.5925-1-mcgrof@kernel.org> <20170123161111.5925-8-mcgrof@kernel.org> <20170125105204.GA5919@kroah.com> <20170125133631.GP13946@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170125133631.GP13946@wotan.suse.de> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 25, 2017 at 02:36:31PM +0100, Luis R. Rodriguez wrote: > On Wed, Jan 25, 2017 at 11:52:04AM +0100, Greg KH wrote: > > On Mon, Jan 23, 2017 at 08:11:11AM -0800, Luis R. Rodriguez wrote: > > > Since commit 5d47ec02c37ea632398cb251c884e3a488dff794 > > > ("firmware: Correct handling of fw_state_wait() return value") > > > fw_load_abort(fw_priv) could be called twice and lead us to a > > > kernel crash. This happens only when the firmware fallback mechanism > > > (regular or custom) is used. The fallback mechanism exposes a sysfs > > > interface for userspace to upload a file and notify the kernel when > > > the file is loaded and ready, or to cancel an upload by echo'ing -1 > > > into on the loading file: > > > > > > echo -n "-1" > /sys/$DEVPATH/loading > > > > > > This will call fw_load_abort(). Some distributions actually have > > > a udev rule in place to *always* immediately cancel all firmware > > > fallback mechanism requests (Debian, OpenSUSE), they have: I made a typo here, OpenSUSE in fact does not carry this. Its so far only Debian I am aware of. > > > $ cat /lib/udev/rules.d/50-firmware.rules > > > # stub for immediately telling the kernel that userspace firmware loading > > > # failed; necessary to avoid long timeouts with CONFIG_FW_LOADER_USER_HELPER=y > > > SUBSYSTEM=="firmware", ACTION=="add", ATTR{loading}="-1 Luis