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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 BF85EC433E0 for ; Thu, 30 Jul 2020 08:15:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A50382074B for ; Thu, 30 Jul 2020 08:15:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729842AbgG3IPv (ORCPT ); Thu, 30 Jul 2020 04:15:51 -0400 Received: from mout.kundenserver.de ([217.72.192.73]:45173 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729032AbgG3IPp (ORCPT ); Thu, 30 Jul 2020 04:15:45 -0400 Received: from mail-qt1-f176.google.com ([209.85.160.176]) by mrelayeu.kundenserver.de (mreue106 [212.227.15.145]) with ESMTPSA (Nemesis) id 1MY6TD-1kHxuV1Fsr-00YUKZ; Thu, 30 Jul 2020 10:15:42 +0200 Received: by mail-qt1-f176.google.com with SMTP id x12so11210249qtp.1; Thu, 30 Jul 2020 01:15:42 -0700 (PDT) X-Gm-Message-State: AOAM532Ly3J/00BP5r02+s9oIEYyILDMBnNb6VdzpkVQjuqGGB2a34S/ HjU5XYYp2T2kz62PUS2Y/MOmGn9GZbML1uu8iY8= X-Google-Smtp-Source: ABdhPJy9qE8d6D2vfgEVw6kVbtwQLGW5Rqh6b1z9O7UyiXPqU5prrGsm5t9N2iViOWRfC5+t73qPilDnnD91WD12O3g= X-Received: by 2002:ac8:5195:: with SMTP id c21mr1813995qtn.304.1596096941108; Thu, 30 Jul 2020 01:15:41 -0700 (PDT) MIME-Version: 1.0 References: <20200726220557.102300-1-yepeilin.cs@gmail.com> <20200726222703.102701-1-yepeilin.cs@gmail.com> <20200727131608.GD1913@kadam> <20200728130632.GI1913@kadam> In-Reply-To: From: Arnd Bergmann Date: Thu, 30 Jul 2020 10:15:24 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [Linux-kernel-mentees] [PATCH v3] media/v4l2-core: Fix kernel-infoleak in video_put_user() To: Bartosz Golaszewski Cc: Dan Carpenter , Linus Walleij , Peilin Ye , Mauro Carvalho Chehab , Greg Kroah-Hartman , syzkaller-bugs , Hans Verkuil , Sakari Ailus , Laurent Pinchart , Vandana BN , Ezequiel Garcia , =?UTF-8?Q?Niklas_S=C3=B6derlund?= , linux-kernel-mentees@lists.linuxfoundation.org, Linux Media Mailing List , "linux-kernel@vger.kernel.org" , Andy Shevchenko Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:rvPNdbTTV7PaspPk9G0gnb1jPuuq8fWQC4VHq/Sx6CBresvnL3l tNEWWc3/5FJzPB5NxQZx9mprgop9zm6vIYT5oXYqyEcivzLtClTQcMNu/tKCSRttoPHeW5R ZuUWB9ACTR2fx6p6M7ebBmo3KoffQQz386BmQQsmVmjnQdGrbpuqUvIf5JRzH14mKa3ijSy xcBemIrm27HsLeX/n3ItA== X-UI-Out-Filterresults: notjunk:1;V03:K0:Q+oEQ8b4lzY=:voa7ymqcQ0Gw85U92BLmZd WleBmJHJhjeTVct+sGqSmb5VHOd9vg/U8wdBAajs7qrFZlt5qlTnFYS0gEzA2TPN1V3+MCz+B F2weSfp8HPvbWAYsDOXAY6eellq9j4sfriTaNJDqavBrMHbMK7qAk2mKSCeYrElM9qncJVGhs gSBugGNqB/cAUCuXqpRhxDPRlMCgqO7k3bzV1aArzMLf+fScjWRoSY2CKrashR7z3WMtYJQiL hmLMFkddnSYtCbc/lEh/u+FnpY8265y5v942dBKeIYaq5J4/b+7QbMAKdZRBd0zZVgR1jv3if scHZqcDhQdXcBSnseeIM7QvwoFSt4yZXkPvfQ5LH/u2kYlm1MVK645BYoP5QD4v7OuKNdIiiZ uaD+iWMR4ovnrAG77oGPD6kvi1TGxQVxQyehqSGGXjyE05DEy9TQWFVbSlUUf0ELKtM5bCjky xDmS6Sqxo1kB0HTrQIRC9b7/qKRi3IC03hJlJBm+YXPBDYMgZKmvWF40Wmu7p57jRVDtIxGcM pCUrFhaN+QbqaJxd7Ub+UTdAKEXU/5F++8RcdCaJw+ZLB8jhvx/3d7C0uvdHX1GOLCfcb+0T1 k8+zFwM89tRfQuePNbzt9ogYNtRS+RfCoAA9A7ygXGG1wzgQ8nKP4HvIFUQUTAihBxLLqHSPc itxHa+B64V/nQfYUCwsaZ4EQaUd1b9Da0eOMnAwNwBKVRPeoDOCDrODICrtfv9RTcTyCqorYN CX+K0IeMEqYdL/0bIRzuCsHZ9znEv6HWH7UiwebHXDhwP4lJ8i6Im22pjADK8uaOP5ewBLwUt OIrbKzXqm/X6PVa3IbYFofodkpjo3u4J0ZcKMkdODwvzNuOiHZ7OZYGaCbcFgWV2w0nqdlDxM V5Kb2oeCEUBcuTO2tlxOomO6jn3uPi5qy2R3EnWRWcAHXKcCxZlxNgVgTyYMWwOgj33bIWeMZ d/5pBDqXZl/6R+B4jZMeQcM12vo4bAdVRIj6RYOjpGJQBwQo3Lj5b Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 30, 2020 at 10:07 AM Bartosz Golaszewski wrote: > > On Tue, Jul 28, 2020 at 3:58 PM Arnd Bergmann wrote: > > > > On Tue, Jul 28, 2020 at 3:06 PM Dan Carpenter wrote: > > Something like > > > > static int lineevent_put_data(void __user *uptr, struct gpioevent_data *ge) > > { > > #ifdef __x86_64__ > > /* i386 has no padding after 'id' */ > > if (in_ia32_syscall()) { > > struct { > > compat_u64 timestamp __packed; > > u32 id; > > } compat_ge = { ge->timestamp, ge->id }; > > > > if (copy_to_user(uptr, &compat_ge, sizeof(compat_ge))) > > return -EFAULT; > > > > return sizeof(compat_ge); > > } > > #endif > > > > if (copy_to_user(uptr, ge, sizeof(*ge)) > > return -EFAULT; > > > > return sizeof(*ge); > > } > > > > Arnd > > Hi Arnd, > > Andy actually had a patch for that but since this isn't a regression > (it never worked), we decided to leave it as it is and get it right in > v2 API. I would argue that it needs to be fixed anyway, unless you also want to remove the v1 interface for native mode. If this works on 32-bit kernels, on 64-bit kernels with 64-bit user space and on compat 32-bit user space on 64-bit non-x86 architectures, I see no reason to leave it broken specifically on x86 compat user space. There are still reasons to use 32-bit x86 user space for low-memory machines even though native i386 kernels are getting increasingly silly. Arnd 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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 D9066C433DF for ; Thu, 30 Jul 2020 08:15:48 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AFAC22074B for ; Thu, 30 Jul 2020 08:15:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AFAC22074B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arndb.de Authentication-Results: mail.kernel.org; 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Thu, 30 Jul 2020 01:15:41 -0700 (PDT) MIME-Version: 1.0 References: <20200726220557.102300-1-yepeilin.cs@gmail.com> <20200726222703.102701-1-yepeilin.cs@gmail.com> <20200727131608.GD1913@kadam> <20200728130632.GI1913@kadam> In-Reply-To: From: Arnd Bergmann Date: Thu, 30 Jul 2020 10:15:24 +0200 X-Gmail-Original-Message-ID: Message-ID: To: Bartosz Golaszewski X-Provags-ID: V03:K1:RnDqqp2+PgC+fX5ZG0CHuQhdu8DjS68FWEwdOuvZI4jH6G3BGjo Fy4AqeSs1MUs8+wuiUk9KiqBIWnyRNIzWK/WWRvdehuaYYdTz9lnPksUAsyThSkiHNyUt33 gK5NNY03xeg2QsbhKn28X4Wfn2Hh17p4ZXyg7diROBHFuImXD1DqRlMHGe1Nn/X704MFnnB 07g1oE9Fpds3gy+bDaRKw== X-UI-Out-Filterresults: notjunk:1;V03:K0:+i19WcfOYSI=:2decvDUGA3lFyTtlvj0KNf gsdxrsmCHg80hkv73uHCbs/GZ6JKYwrigyrwIzNRs/mEeJVZES2rM8LpK0XYIzmDOz3b+Pwe3 3YvDchSz9WGyiZzWiovmYVZUhYGToUwXDEIHMgrWCxfe1+xhBKbPKHWRhxV+HxUOhLNff43qn v4i188rHKhhwrjgScljN9ynrlTkWa0oYJFjwcUJ99YqALcAUddbrDgJIKBwox7rf7GTDbzysL pheRiwD2eIEu/XWZ/50nXd1Hi7fbqjOwW5lZWkwWpneOF8pT/hKrFd/rO8A2SSpcUn0jm35yx TIFpLw+SdmCbc8Y9qZe/Pix0/2DzSBrlPwdIaKCvuP8MuCJQTI5N6g6WI3Fd7ZyeTUxFkyf3S +pIaasamwmSPc5xSYlv20O8z8qOJHgFjtUngpnwDrHc7ZLv4OGFRaoNHW6hIDlkGLXx/lyRbE dsmsguYvrl2CiQGwZStiuBMfQTsd/zPgggvTxmYlS13X3c9f9CTF4aPc6E/j6EzmvSpQyG1n1 Dkh3c6lTCZH8o+Br/F0er1Ypst7RSjnsQDieRgYf2eQ6fdoQhuh90+2b1E5FbL7yftTKwTWvk h86NnTYZoLcAlTqQih6FS6H7nSnQ9Q/dEZE7WFzk25iLD2hGADM7cAuBmGP61yJFLvqWKONad vG0w2h9zfUzdqB7WOC1C8nOAY2zBHUdWZHckYI1zEgvLRBa//OkVix0F5cgYzGChOiI91NX1G yEFjXiOqw71KrOXUY592yJdLOU6HUqFM7fndZeNdYbyomVcFine3hUUGBpbEN2WWmubR7gvWR +gOuIY+cIMubWXE4dA39ecJ3ZWTcMVG9qN6ltguk+0OSJpM6Ga9xS5Qq6z6H2iZqSUPjub9P3 8vQnSA37qddGYfWKJlKE3TcCqEwjdu/y4tW4ZA6BMMN0OfGRDgQ9ueMFIS9pqj/kWYcS1hDoG 5rrqGOxf4RP0/knwae/bldzYU/+opJqO59eisODfTbB9jtjlFOkRc Cc: =?UTF-8?Q?Niklas_S=C3=B6derlund?= , Andy Shevchenko , Linus Walleij , syzkaller-bugs , Linux Media Mailing List , "linux-kernel@vger.kernel.org" , Laurent Pinchart , Sakari Ailus , Vandana BN , Hans Verkuil , Mauro Carvalho Chehab , Ezequiel Garcia , Peilin Ye , Dan Carpenter , linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [Linux-kernel-mentees] [PATCH v3] media/v4l2-core: Fix kernel-infoleak in video_put_user() X-BeenThere: linux-kernel-mentees@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-kernel-mentees-bounces@lists.linuxfoundation.org Sender: "Linux-kernel-mentees" On Thu, Jul 30, 2020 at 10:07 AM Bartosz Golaszewski wrote: > > On Tue, Jul 28, 2020 at 3:58 PM Arnd Bergmann wrote: > > > > On Tue, Jul 28, 2020 at 3:06 PM Dan Carpenter wrote: > > Something like > > > > static int lineevent_put_data(void __user *uptr, struct gpioevent_data *ge) > > { > > #ifdef __x86_64__ > > /* i386 has no padding after 'id' */ > > if (in_ia32_syscall()) { > > struct { > > compat_u64 timestamp __packed; > > u32 id; > > } compat_ge = { ge->timestamp, ge->id }; > > > > if (copy_to_user(uptr, &compat_ge, sizeof(compat_ge))) > > return -EFAULT; > > > > return sizeof(compat_ge); > > } > > #endif > > > > if (copy_to_user(uptr, ge, sizeof(*ge)) > > return -EFAULT; > > > > return sizeof(*ge); > > } > > > > Arnd > > Hi Arnd, > > Andy actually had a patch for that but since this isn't a regression > (it never worked), we decided to leave it as it is and get it right in > v2 API. I would argue that it needs to be fixed anyway, unless you also want to remove the v1 interface for native mode. If this works on 32-bit kernels, on 64-bit kernels with 64-bit user space and on compat 32-bit user space on 64-bit non-x86 architectures, I see no reason to leave it broken specifically on x86 compat user space. There are still reasons to use 32-bit x86 user space for low-memory machines even though native i386 kernels are getting increasingly silly. Arnd _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees