Received: by 2002:a05:6a10:22f:0:0:0:0 with SMTP id 15csp1695395pxk; Fri, 2 Oct 2020 17:05:35 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxkJMGokLs6/RUPszW7QClU2217pDvrpc8I/onu6VhCdn6Py5Zh52EovTaug8+4TP15x7uw X-Received: by 2002:a50:cd51:: with SMTP id d17mr5197889edj.93.1601683535316; Fri, 02 Oct 2020 17:05:35 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1601683535; cv=none; d=google.com; s=arc-20160816; b=IEZ9STu5UfXjG4Wulerllb18d3Mu+fgd/qT9MJaPxzEuLnOhw/Bxs6L+6qJKK31B37 5DzW9Apam6n5LgsBdULK22r5ABiiPUCIuYXe2PUGZSOurhnNQ4RBrLju/QmMozW5kmyt uhUEZrNYg69iCTMYzA7Be4YIE0iTYD9KenrQ/G97/hZ295tzz99JVfo014xK9De1rBUP QfNLBDOCmxbzIdvTTdG2OWcMHT+TX8H1ltqJ6LftVH8puPiDvJNT249YfUd4ktpP1xHa m0dKIKWJOf2pBWhMD2PMQsaHKPOfZHL3YwAVaS5YhNhrl9fRaWT6dNQ7SutVaOZd5k6Y 1GCw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:user-agent:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :dkim-signature; bh=5NrctcE0AoC02LQFJ/hz9FFzGw+TpSiTB2qeUuK0M3M=; b=DrfvOGGHEc97lhVqnygduYqOpmEUc4/rvLLp82s/zwiwzvgeYWMliR91bEKcxZr0Hr 8TUZKPt3T7JnAaw8Gb7/ssH1sEuEc/J0emwHtC2Dx7J+bcIIvlB4G7K7wWeBoQ4fzH+T 0In2NMsXaylRpuf8s2Tjvdzz7j5alFA0GYQOC2QM82ORSqNeR6N/fEWYfWXFEeMSUVkS OBnihXS9f65p2Oqp9zsfn+TZiM66tKxLUANk2Hf2DKp3JJ9QSbTKddX8nP8EEOeCVwhp w8/riQe5Y3tm+fstlTYSzHIY8FK0IOICEGt7VCCZgWvU3QjK97p6sMLBWdN4KQC9sJij IO6A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=Kg4snDc1; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id d21si2098047edp.484.2020.10.02.17.05.12; Fri, 02 Oct 2020 17:05:35 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=Kg4snDc1; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725747AbgJCACA (ORCPT + 99 others); Fri, 2 Oct 2020 20:02:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:50740 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725283AbgJCAB7 (ORCPT ); Fri, 2 Oct 2020 20:01:59 -0400 Received: from embeddedor (187-162-31-110.static.axtel.net [187.162.31.110]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EEEA5206DB; Sat, 3 Oct 2020 00:01:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601683319; bh=YarLC7J+uN1jSYC1aDZSX885mquzRD1NzzjMUASoJ7Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Kg4snDc1gpLzKh+ReaG+iKy3IPg5KJiK/YD1x3IDWjC8loKB2qKN1BxoN3ybnXYtO 6C55n9psbbELbqSRFSacLtCBgQ+GdTCrRbVc/Q0HQ7GzH5uG6+v2qJSuVCrnSgE0FZ rbWsjjtaE8EDKhYlHWRz0hMsGrHVH/s4SMG1qSUM= Date: Fri, 2 Oct 2020 19:07:48 -0500 From: "Gustavo A. R. Silva" To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Kees Cook Subject: Re: [PATCH][next] block: scsi_ioctl: Avoid the use of one-element arrays Message-ID: <20201003000748.GB13557@embeddedor> References: <20201002231033.GA6273@embeddedor> <20201003000338.GA13557@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 02, 2020 at 05:58:33PM -0600, Jens Axboe wrote: > >>> - void __user *reserved[1]; /* unused, actually */ > >>> + union { > >>> + void __user *reserved[1]; /* unused, actually */ > >>> + void __user *unused; > >>> + }; > >> > >> What's the point of this union, why not just turn it into > >> > >> void * __user *unused; > >> > >> ? > > > > I just don't want to take any chances of breaking any user-space > > application that, for some reason, may be considering that field. > > I guess that's a valid concern, who knows what applications are doing > to an ignored field. > > I'll apply it, thanks. Awesome. :) Thanks. -- Gustavo