Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933340AbdC3BmI (ORCPT ); Wed, 29 Mar 2017 21:42:08 -0400 Received: from mail.netline.ch ([148.251.143.178]:36836 "EHLO netline-mail3.netline.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754231AbdC3BmG (ORCPT ); Wed, 29 Mar 2017 21:42:06 -0400 Subject: Re: [PATCH] Fix IB va_start+ib_bytes range check on 32Bit systems To: =?UTF-8?Q?Christian_K=c3=b6nig?= , Jan Burgmeier Cc: airlied@linux.ie, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20170329091839.5246-1-jan.burgmeier@unicon-software.com> <20170329091839.5246-2-jan.burgmeier@unicon-software.com> <6dc2814c-c32b-220a-daa7-da530d13f20d@vodafone.de> <26c98d79-025c-bdf6-4bbe-bfd083cb6720@daenzer.net> From: =?UTF-8?Q?Michel_D=c3=a4nzer?= Message-ID: <07c31b2e-5dfa-0e6b-2961-44c1bdf47fe1@daenzer.net> Date: Thu, 30 Mar 2017 10:41:51 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1979 Lines: 45 On 30/03/17 12:18 AM, Christian König wrote: > Am 29.03.2017 um 16:54 schrieb Michel Dänzer: >> On 29/03/17 10:22 PM, Christian König wrote: >>> Am 29.03.2017 um 11:18 schrieb Jan Burgmeier: >>>> Signed-off-by: Jan Burgmeier >>>> --- >>>> drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 4 +++- >>>> 1 file changed, 3 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c >>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c >>>> index 99424cb8020b..583d22974e14 100644 >>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c >>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c >>>> @@ -908,6 +908,7 @@ static int amdgpu_cs_ib_fill(struct amdgpu_device >>>> *adev, >>>> struct amdgpu_bo *aobj = NULL; >>>> uint64_t offset; >>>> uint8_t *kptr; >>>> + uint64_t it_last; >>>> m = amdgpu_cs_find_mapping(parser, chunk_ib->va_start, >>>> &aobj); >>>> @@ -916,8 +917,9 @@ static int amdgpu_cs_ib_fill(struct amdgpu_device >>>> *adev, >>>> return -EINVAL; >>>> } >>>> + it_last = m->it.last; >>>> if ((chunk_ib->va_start + chunk_ib->ib_bytes) > >>>> - (m->it.last + 1) * AMDGPU_GPU_PAGE_SIZE) { >>>> + (it_last + 1) * AMDGPU_GPU_PAGE_SIZE) { >>> Nice catch, but just adding a u64 case should do here as well. E.g: >>> >>> if ((chunk_ib->va_start + chunk_ib->ib_bytes) > >>> (u64)(m->it.last + 1) * AMDGPU_GPU_PAGE_SIZE) { >> That won't work correctly if m->it.last == 0xffffffff ? Or is that not >> possible? > Hui, why? is it.last signed? No. If m->it.last == 0xffffffff, (m->it.last + 1) == 0, the u64 cast won't change that. I thought that would be bad, but maybe not? -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer