From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753947AbcEWM4q (ORCPT ); Mon, 23 May 2016 08:56:46 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:35154 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753903AbcEWM4p (ORCPT ); Mon, 23 May 2016 08:56:45 -0400 Date: Mon, 23 May 2016 14:56:45 +0200 From: Daniel Vetter To: Eric Engestrom Cc: Heinrich Schuchardt , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH] drm/mm: avoid possible null pointer dereference Message-ID: <20160523125645.GY27098@phenom.ffwll.local> Mail-Followup-To: Eric Engestrom , Heinrich Schuchardt , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org References: <1463602639-4861-1-git-send-email-xypron.glpk@gmx.de> <20160523102714.GA13596@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160523102714.GA13596@imgtec.com> X-Operating-System: Linux phenom 4.6.0-rc5+ 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 On Mon, May 23, 2016 at 11:27:14AM +0100, Eric Engestrom wrote: > On Wed, May 18, 2016 at 10:17:19PM +0200, Heinrich Schuchardt wrote: > > Do not dereference node before the check if node is NULL. > > > > Signed-off-by: Heinrich Schuchardt > > --- > > drivers/gpu/drm/drm_mm.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c > > index 04de6fd..cb39f45 100644 > > --- a/drivers/gpu/drm/drm_mm.c > > +++ b/drivers/gpu/drm/drm_mm.c > > @@ -179,12 +179,14 @@ static void drm_mm_insert_helper(struct drm_mm_node *hole_node, > > int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node) > > { > > struct drm_mm_node *hole; > > - u64 end = node->start + node->size; > > + u64 end; > > u64 hole_start; > > u64 hole_end; > > > > BUG_ON(node == NULL); > > > > + end = node->start + node->size; > > + > > /* Find the relevant hole to add our node to */ > > drm_mm_for_each_hole(hole, mm, hole_start, hole_end) { > > if (hole_start > node->start || hole_end < end) > > -- > > 2.1.4 > > Reviewed-by: Eric Engestrom Applied to drm-misc, thanks. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch