From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935252AbeEXAhB (ORCPT ); Wed, 23 May 2018 20:37:01 -0400 Received: from mail-oi0-f66.google.com ([209.85.218.66]:35935 "EHLO mail-oi0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935112AbeEXAg7 (ORCPT ); Wed, 23 May 2018 20:36:59 -0400 X-Google-Smtp-Source: AB8JxZpKO7e7WJ+S93dJuS8dFcm1GWgg937rsR+IHpUhVLvh36GOpb0is47F+V4dwHXgLFxJ/+tNYXM5XCC3uthD/s8= MIME-Version: 1.0 In-Reply-To: References: <20180313162411.GA1983@embeddedgus> <20180314110834.GB8564@ulmo> From: Ben Skeggs Date: Thu, 24 May 2018 10:36:58 +1000 Message-ID: Subject: Re: [PATCH v2] drm/nouveau/secboot: remove VLA usage To: Kees Cook Cc: Ben Skeggs , Daniel Vetter , Thierry Reding , "Gustavo A. R. Silva" , David Airlie , nouveau , LKML , Maling list - DRI developers , David Laight Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 24, 2018 at 8:48 AM, Kees Cook wrote: > On Thu, Apr 26, 2018 at 4:25 PM, Kees Cook wrote: >> On Thu, Mar 15, 2018 at 7:05 PM, Ben Skeggs wrote: >>> On 14 March 2018 at 21:08, Thierry Reding wrote: >>>> On Tue, Mar 13, 2018 at 11:24:11AM -0500, Gustavo A. R. Silva wrote: >>>>> In preparation to enabling -Wvla, remove VLA. In this particular >>>>> case directly use macro NVKM_MSGQUEUE_CMDLINE_SIZE instead of local >>>>> variable cmdline_size. Also, remove cmdline_size as it is not >>>>> actually useful anymore. >>>>> >>>>> The use of stack Variable Length Arrays needs to be avoided, as they >>>>> can be a vector for stack exhaustion, which can be both a runtime bug >>>>> or a security flaw. Also, in general, as code evolves it is easy to >>>>> lose track of how big a VLA can get. Thus, we can end up having runtime >>>>> failures that are hard to debug. >>>>> >>>>> Also, fixed as part of the directive to remove all VLAs from >>>>> the kernel: https://lkml.org/lkml/2018/3/7/621 >>>>> >>>>> Signed-off-by: Gustavo A. R. Silva >>>>> --- >>>>> Changes in v2: >>>>> - Use sizeof(buf) instead of NVKM_MSGQUEUE_CMDLINE_SIZE. This change >>>>> is based on the feedback provided by David Laight. Thanks David. >>>>> >>>>> drivers/gpu/drm/nouveau/nvkm/subdev/secboot/ls_ucode_msgqueue.c | 7 +++---- >>>>> 1 file changed, 3 insertions(+), 4 deletions(-) >>>> >>>> Reviewed-by: Thierry Reding >>> Thanks everyone. I've taken the patch in my tree. >> >> Hi! >> >> Just checking in on this -- I don't see this patch in linux-next. Is >> this queued somewhere else? > > Hi, it's been another month; I still don't see this in linux-next. > Daniel, can this go via drm-misc? It's already queued in drm-next. > > -Kees > > -- > Kees Cook > Pixel Security