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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 C04D6C43331 for ; Sat, 9 Nov 2019 11:39:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 94CF721882 for ; Sat, 9 Nov 2019 11:39:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726399AbfKILju (ORCPT ); Sat, 9 Nov 2019 06:39:50 -0500 Received: from lb2-smtp-cloud7.xs4all.net ([194.109.24.28]:34293 "EHLO lb2-smtp-cloud7.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726146AbfKILju (ORCPT ); Sat, 9 Nov 2019 06:39:50 -0500 Received: from [192.168.2.10] ([46.9.232.237]) by smtp-cloud7.xs4all.net with ESMTPA id TP5kiwap4PMT8TP5niPDcx; Sat, 09 Nov 2019 12:39:48 +0100 Subject: Re: [PATCH] media:usb:cpia2: Properly check framebuffer mmap offsets To: Greg Kroah-Hartman , Omer Shalev Cc: Mauro Carvalho Chehab , Kate Stewart , Richard Fontana , Allison Randal , Thomas Gleixner , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org References: <20191108215038.59170-1-omerdeshalev@gmail.com> <20191108204949.GA1277001@kroah.com> From: Hans Verkuil Message-ID: Date: Sat, 9 Nov 2019 12:39:43 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191108204949.GA1277001@kroah.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4wfNAeKckKDRAZWl52xYYip05gsvA0m/eTA2Ae9CdaDm8OEnv7tiZbBlho0EmZRCVrcxlSEjXi5AZT2PF+bk0hXDYCQbNPr8Ws4Gg9Z6JGXgGVjcp+6hXC l3sQW6V9d8gxaloV2xX76pjm0Fee6MKjnnFn7+KnM9A+lqrc8LeksfmGAO9hB9IOv81nBJAh+9zJrjVpmTeHXfL6mAOHVh0C+4uxEb/2akxj+CgVWQd3rKHJ YV63xfKqufxTe18e1vlGKhPuV0AxHKXCdNHq3Fmf1rqvL0ax/UYORhm9tCxCI0hg2UM+KJ6lFSMKSbKYCAm2gznHObJZeVkErrBpiz95QT1YG46YY9YyeFaY 0YmbCh16mNBsRXN/dBgHawYJotU6d3TiCv7KQmYdLCydW2BAEg63p/SMatHse8Annyo9+TWYSgPLpDbfXmlKp3NlyXxqgM65NcX9mxM30Ff2OZxMyTk= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, On 11/8/19 9:49 PM, Greg Kroah-Hartman wrote: > On Fri, Nov 08, 2019 at 09:50:36PM +0000, Omer Shalev wrote: >> The cpai2 driver's mmap implementation wasn't properly check for all >> possible offset values. Given a huge offset value , the calculation >> start_offset + size can wrap around to a low value and pass the check > > I thought we checked that in the core of the kernel now, to keep all > drivers from not having to do this type of thing (as they obviously all > forgot to.) Why is this still needed here as well? Where is that checked in the core? I couldn't find anything, but I might have been looking in the wrong place. Regards, Hans > > thanks, > > greg k-h >