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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 0EC69C43441 for ; Mon, 12 Nov 2018 10:19:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BF8BB223D8 for ; Mon, 12 Nov 2018 10:19:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BK4i63bU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BF8BB223D8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728231AbeKLUMS (ORCPT ); Mon, 12 Nov 2018 15:12:18 -0500 Received: from mail-wm1-f67.google.com ([209.85.128.67]:53123 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725873AbeKLUMS (ORCPT ); Mon, 12 Nov 2018 15:12:18 -0500 Received: by mail-wm1-f67.google.com with SMTP id r11-v6so7865479wmb.2; Mon, 12 Nov 2018 02:19:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:subject:to:references:from:openpgp:autocrypt:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=PIW2d66vHTApqG4+T89kd3a3Y0+9UA9ghJAF2Ej0Thk=; b=BK4i63bUfRSgN+h2pkCIRKekrCxh+BW3d26O/cx+fL1d9byICV17rogfRrT4ZXvXIV UHQpsh5wBgNY6NxC3tHMKwZjkwmyw2s2YZFSTe1TvBfiTMs0RKd4DumOsznUspyGgmzp pA0AzBvHZxSGQt4QaHrvvzhbnQT9p2GLcHA4qtCDcjEHlHFmkqMdR9fmVfBI+36jAPQc /fPMyMF+VV1oSSsaVt1+eczYqz+o0+D9N58XMpNVfwU96OQTpM+49QgpoEpdckz1cdiU dajaSD+Wy8gJXBIJlgFfHB9f6KdSzGLUgMYXSwo0e6KcHBTeYlEjAWrBBnN+LpHiiXkA 9mjg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:subject:to:references:from:openpgp :autocrypt:message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=PIW2d66vHTApqG4+T89kd3a3Y0+9UA9ghJAF2Ej0Thk=; b=VT5rA+eg13Lc+5LtfumiZvEbFbe46PyxXPiwa3Rmj0LiDlNqj9yw/jbsil5jecXA3R kNRBjnBskQKmVNXiw44HW4OIdnzOr46ocy8SphjRvWmlHzPI3oAfz7vVyV+2sghvl2/M KZoSKChIG/JXLjaFj1mWK5+6xam051173jwImjsLWVZ6kZx/ExQa+KpZbbzwb/9QJwtv K87IA5ODB11I3r3MJh6ZHW7JJxrpM2vacy9XE9stbphWnXvV5DlVkzfeneVuH2cq0Sd4 8eMjlyEgOpchhLqNIKkk7YTSZuFYL3ZXuTsXlfZHGCtLM5FiPsdGst2ssLF4B/aw1Tzl 7OJg== X-Gm-Message-State: AGRZ1gIIOn/jbWix5CfAoMH9va8DAELtEX4lO+FoMVMAf6jLARMkcJpP s50WKm+8fXSRKFRMuBjm+lU= X-Google-Smtp-Source: AJdET5fbR7BAyD2OUMb2o5ms+U8dCYlVY9c3jyCzGvOWGAg0Pbi57JbZSVSa1tmVG56u3iDGsc9XMw== X-Received: by 2002:a1c:c483:: with SMTP id u125mr836794wmf.14.1542017981853; Mon, 12 Nov 2018 02:19:41 -0800 (PST) Received: from [192.168.10.165] ([93.56.166.5]) by smtp.googlemail.com with ESMTPSA id y138sm1141586wmc.16.2018.11.12.02.19.40 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 12 Nov 2018 02:19:41 -0800 (PST) Subject: Re: [PATCH 0/3] SG_IO command filtering via sysfs To: Christoph Hellwig , "Theodore Y. Ts'o" , linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, Hannes Reinecke , "Martin K. Petersen" , James Bottomley References: <1541867733-7836-1-git-send-email-pbonzini@redhat.com> <20181111131445.GB25441@infradead.org> <20181111134241.GA2447@thunk.org> <20181112082013.GA9307@infradead.org> From: Paolo Bonzini Openpgp: preference=signencrypt Autocrypt: addr=pbonzini@redhat.com; keydata= xsEhBFRCcBIBDqDGsz4K0zZun3jh+U6Z9wNGLKQ0kSFyjN38gMqU1SfP+TUNQepFHb/Gc0E2 CxXPkIBTvYY+ZPkoTh5xF9oS1jqI8iRLzouzF8yXs3QjQIZ2SfuCxSVwlV65jotcjD2FTN04 hVopm9llFijNZpVIOGUTqzM4U55sdsCcZUluWM6x4HSOdw5F5Utxfp1wOjD/v92Lrax0hjiX DResHSt48q+8FrZzY+AUbkUS+Jm34qjswdrgsC5uxeVcLkBgWLmov2kMaMROT0YmFY6A3m1S P/kXmHDXxhe23gKb3dgwxUTpENDBGcfEzrzilWueOeUWiOcWuFOed/C3SyijBx3Av/lbCsHU Vx6pMycNTdzU1BuAroB+Y3mNEuW56Yd44jlInzG2UOwt9XjjdKkJZ1g0P9dwptwLEgTEd3Fo UdhAQyRXGYO8oROiuh+RZ1lXp6AQ4ZjoyH8WLfTLf5g1EKCTc4C1sy1vQSdzIRu3rBIjAvnC tGZADei1IExLqB3uzXKzZ1BZ+Z8hnt2og9hb7H0y8diYfEk2w3R7wEr+Ehk5NQsT2MPI2QBd wEv1/Aj1DgUHZAHzG1QN9S8wNWQ6K9DqHZTBnI1hUlkp22zCSHK/6FwUCuYp1zcAEQEAAc0f UGFvbG8gQm9uemluaSA8Ym9uemluaUBnbnUub3JnPsLBTQQTAQIAIwUCVEJ7AwIbAwcLCQgH AwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEH4VEAzNNmmxNcwOniaZVLsuy1lW/ntYCA0Caz0i sHpmecK8aWlvL9wpQCk4GlOX9L1emyYXZPmzIYB0IRqmSzAlZxi+A2qm9XOxs5gJ2xqMEXX5 FMtUH3kpkWWJeLqe7z0EoQdUI4EG988uv/tdZyqjUn2XJE+K01x7r3MkUSFz/HZKZiCvYuze VlS0NTYdUt5jBXualvAwNKfxEkrxeHjxgdFHjYWhjflahY7TNRmuqPM/Lx7wAuyoDjlYNE40 Z+Kun4/KjMbjgpcF4Nf3PJQR8qXI6p3so2qsSn91tY7DFSJO6v2HwFJkC2jU95wxfNmTEUZc znXahYbVOwCDJRuPrE5GKFd/XJU9u5hNtr/uYipHij01WXal2cce1S5mn1/HuM1yo1u8xdHy IupCd57EWI948e8BlhpujUCU2tzOb2iYS0kpmJ9/oLVZrOcSZCcCl2P0AaCAsj59z2kwQS9D du0WxUs8waso0Qq6tDEHo8yLCOJDzSz4oojTtWe4zsulVnWV+wu70AioemAT8S6JOtlu60C5 dHgQUD1Tp+ReXpDKXmjbASJx4otvW0qah3o6JaqO79tbDqIvncu3tewwp6c85uZd48JnIOh3 utBAu684nJakbbvZUGikJfxd887ATQRUQnHuAQgAx4dxXO6/Zun0eVYOnr5GRl76+2UrAAem Vv9Yfn2PbDIbxXqLff7oyVJIkw4WdhQIIvvtu5zH24iYjmdfbg8iWpP7NqxUQRUZJEWbx2CR wkMHtOmzQiQ2tSLjKh/cHeyFH68xjeLcinR7jXMrHQK+UCEw6jqi1oeZzGvfmxarUmS0uRuf fAb589AJW50kkQK9VD/9QC2FJISSUDnRC0PawGSZDXhmvITJMdD4TjYrePYhSY4uuIV02v02 8TVAaYbIhxvDY0hUQE4r8ZbGRLn52bEzaIPgl1p/adKfeOUeMReg/CkyzQpmyB1TSk8lDMxQ zCYHXAzwnGi8WU9iuE1P0wARAQABwsEzBBgBAgAJBQJUQnHuAhsMAAoJEH4VEAzNNmmxp1EO oJy0uZggJm7gZKeJ7iUpeX4eqUtqelUw6gU2daz2hE/jsxsTbC/w5piHmk1H1VWDKEM4bQBT uiJ0bfo55SWsUNN+c9hhIX+Y8LEe22izK3w7mRpvGcg+/ZRG4DEMHLP6JVsv5GMpoYwYOmHn plOzCXHvmdlW0i6SrMsBDl9rw4AtIa6bRwWLim1lQ6EM3PWifPrWSUPrPcw4OLSwFk0CPqC4 HYv/7ZnASVkR5EERFF3+6iaaVi5OgBd81F1TCvCX2BEyIDRZLJNvX3TOd5FEN+lIrl26xecz 876SvcOb5SL5SKg9/rCBufdPSjojkGFWGziHiFaYhbuI2E+NfWLJtd+ZvWAAV+O0d8vFFSvr iy9enJ8kxJwhC0ECbSKFY+W1eTIhMD3aeAKY90drozWEyHhENf4l/V+Ja5vOnW+gCDQkGt2Y 1lJAPPSIqZKvHzGShdh8DduC0U3xYkfbGAUvbxeepjgzp0uEnBXfPTy09JGpgWbg0w91GyfT /ujKaGd4vxG2Ei+MMNDmS1SMx7wu0evvQ5kT9NPzyq8R2GIhVSiAd2jioGuTjX6AZCFv3ToO 53DliFMkVTecLptsXaesuUHgL9dKIfvpm+rNXRn9wAwGjk0X/A== Message-ID: <79d7d4b2-e9b3-00b4-2ad0-789888f7ee36@redhat.com> Date: Mon, 12 Nov 2018 11:17:29 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <20181112082013.GA9307@infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/11/2018 09:20, Christoph Hellwig wrote: > On Sun, Nov 11, 2018 at 08:42:42AM -0500, Theodore Y. Ts'o wrote: >> It really depends on the security model being used on a particular >> system. I can easily imagine scenarios where userspace is allowed >> full access to the device with respect to read/write/open, but the >> security model doesn't want to allow access to various SCSI commands >> such as firmware upload commands, TCG commads, the >> soon-to-be-standardized Zone Activation Commands (which allow dynamic >> conversion of HDD recording modes between CMR and SMR), etc. > > Well, that's what we have the security_file_ioctl() LSM hook for so that > your security model can arbitrate access to ioctls. Doesn't that have TOC-TOU races by design? Also, what about SG_IO giving write access to files that are only opened read-only (and only have read permissions)? Paolo