From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE253C43387 for ; Fri, 21 Dec 2018 09:09:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A3EA6218F0 for ; Fri, 21 Dec 2018 09:09:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731119AbeLUJJ2 (ORCPT ); Fri, 21 Dec 2018 04:09:28 -0500 Received: from mail.netline.ch ([148.251.143.178]:57159 "EHLO netline-mail3.netline.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725845AbeLUJJ2 (ORCPT ); Fri, 21 Dec 2018 04:09:28 -0500 Received: from localhost (localhost [127.0.0.1]) by netline-mail3.netline.ch (Postfix) with ESMTP id B5C672A6056; Fri, 21 Dec 2018 10:09:25 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at netline-mail3.netline.ch Received: from netline-mail3.netline.ch ([127.0.0.1]) by localhost (netline-mail3.netline.ch [127.0.0.1]) (amavisd-new, port 10024) with LMTP id Few-6Rukxvrp; Fri, 21 Dec 2018 10:09:25 +0100 (CET) Received: from thor (39.1.199.178.dynamic.wline.res.cust.swisscom.ch [178.199.1.39]) by netline-mail3.netline.ch (Postfix) with ESMTPSA id 16B992A6055; Fri, 21 Dec 2018 10:09:25 +0100 (CET) Received: from localhost ([::1]) by thor with esmtp (Exim 4.91) (envelope-from ) id 1gaGo8-0001Lw-Pi; Fri, 21 Dec 2018 10:09:24 +0100 Subject: Re: [PATCH 3/3] drm/amd: validate user GEM object size To: Yu Zhao , David Airlie , Daniel Vetter , =?UTF-8?Q?Christian_K=c3=b6nig?= , Alex Deucher Cc: David Zhou , Daniel Stone , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, Samuel Li , Junwei Zhang , Harry Wentland References: <20181221031053.240161-1-yuzhao@google.com> <20181221031053.240161-3-yuzhao@google.com> From: =?UTF-8?Q?Michel_D=c3=a4nzer?= Openpgp: preference=signencrypt Autocrypt: addr=michel@daenzer.net; prefer-encrypt=mutual; keydata= mQGiBDsehS8RBACbsIQEX31aYSIuEKxEnEX82ezMR8z3LG8ktv1KjyNErUX9Pt7AUC7W3W0b LUhu8Le8S2va6hi7GfSAifl0ih3k6Bv1Itzgnd+7ZmSrvCN8yGJaHNQfAevAuEboIb+MaVHo 9EMJj4ikOcRZCmQWw7evu/D9uQdtkCnRY9iJiAGxbwCguBHtpoGMxDOINCr5UU6qt+m4O+UD /355ohBBzzyh49lTj0kTFKr0Ozd20G2FbcqHgfFL1dc1MPyigej2gLga2osu2QY0ObvAGkOu WBi3LTY8Zs8uqFGDC4ZAwMPoFy3yzu3ne6T7d/68rJil0QcdQjzzHi6ekqHuhst4a+/+D23h Za8MJBEcdOhRhsaDVGAJSFEQB1qLBACOs0xN+XblejO35gsDSVVk8s+FUUw3TSWJBfZa3Imp V2U2tBO4qck+wqbHNfdnU/crrsHahjzBjvk8Up7VoY8oT+z03sal2vXEonS279xN2B92Tttr AgwosujguFO/7tvzymWC76rDEwue8TsADE11ErjwaBTs8ZXfnN/uAANgPLQjTWljaGVsIERh ZW56ZXIgPG1pY2hlbEBkYWVuemVyLm5ldD6IXgQTEQIAHgUCQFXxJgIbAwYLCQgHAwIDFQID AxYCAQIeAQIXgAAKCRBaga+OatuyAIrPAJ9ykonXI3oQcX83N2qzCEStLNW47gCeLWm/QiPY jqtGUnnSbyuTQfIySkK5AQ0EOx6FRRAEAJZkcvklPwJCgNiw37p0GShKmFGGqf/a3xZZEpjI qNxzshFRFneZze4f5LhzbX1/vIm5+ZXsEWympJfZzyCmYPw86QcFxyZflkAxHx9LeD+89Elx bw6wT0CcLvSv8ROfU1m8YhGbV6g2zWyLD0/naQGVb8e4FhVKGNY2EEbHgFBrAAMGA/0VktFO CxFBdzLQ17RCTwCJ3xpyP4qsLJH0yCoA26rH2zE2RzByhrTFTYZzbFEid3ddGiHOBEL+bO+2 GNtfiYKmbTkj1tMZJ8L6huKONaVrASFzLvZa2dlc2zja9ZSksKmge5BOTKWgbyepEc5qxSju YsYrX5xfLgTZC5abhhztpYhGBBgRAgAGBQI7HoVFAAoJEFqBr45q27IAlscAn2Ufk2d6/3p4 Cuyz/NX7KpL2dQ8WAJ9UD5JEakhfofed8PSqOM7jOO3LCA== Message-ID: <1e804635-e7a4-2cf6-956a-3e140f8d0e7d@daenzer.net> Date: Fri, 21 Dec 2018 10:09:24 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <20181221031053.240161-3-yuzhao@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-CA Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-12-21 4:10 a.m., Yu Zhao wrote: > When creating frame buffer, userspace may request to attach to a > previously allocated GEM object that is smaller than what GPU > requires. Validation must be done to prevent out-of-bound DMA, > which could not only corrupt memory but also reveal sensitive data. > > This fix is not done in a common code path because individual > driver might have different requirement. > > Signed-off-by: Yu Zhao > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > index 755daa332f8a..bb48b016cc68 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > @@ -527,6 +527,7 @@ amdgpu_display_user_framebuffer_create(struct drm_device *dev, > struct drm_gem_object *obj; > struct amdgpu_framebuffer *amdgpu_fb; > int ret; > + int height; > struct amdgpu_device *adev = dev->dev_private; > int cpp = drm_format_plane_cpp(mode_cmd->pixel_format, 0); > int pitch = amdgpu_align_pitch(adev, mode_cmd->width, cpp, false); > @@ -550,6 +551,13 @@ amdgpu_display_user_framebuffer_create(struct drm_device *dev, > return ERR_PTR(-EINVAL); > } > > + height = ALIGN(mode_cmd->height, 8); > + if (obj->size < pitch * height) { > + dev_err(&dev->pdev->dev, "Invalid GEM size: expecting %d but got %d\n", > + pitch * height, obj->size); Same comment as patch 2, and maybe write "expecting >= %d but got %d" for clarity. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer