Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754796Ab2FERI6 (ORCPT ); Tue, 5 Jun 2012 13:08:58 -0400 Received: from s15943758.onlinehome-server.info ([217.160.130.188]:37555 "EHLO mail.x86-64.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753366Ab2FERI5 (ORCPT ); Tue, 5 Jun 2012 13:08:57 -0400 Date: Tue, 5 Jun 2012 19:09:21 +0200 From: Borislav Petkov To: Linus Torvalds Cc: Borislav Petkov , Christopher Yeoh , Andrew Morton , LKML , Randy Dunlap Subject: Re: [PATCH] CMA: Do no enable it by default Message-ID: <20120605170921.GO13495@aftab.osrc.amd.com> References: <20120531153512.GK14515@aftab.osrc.amd.com> <20120531154224.GL14515@aftab.osrc.amd.com> <20120601110647.2c446aa7@rockpopper> <20120605110541.GC13495@aftab.osrc.amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1663 Lines: 46 On Tue, Jun 05, 2012 at 09:46:49AM -0700, Linus Torvalds wrote: > On Tue, Jun 5, 2012 at 4:05 AM, Borislav Petkov wrote: > > > > Besides, in the config option it says "... which allow a process with > > the correct privileges to directly read from or write to to another > > process's address space.", which, if the reading process has somehow > > gained privileges (as that never happens) is your security issue right > > there. > > What? > > It's using the same privileges as ptrace. If you are allowed to ptrace > somebody, there's no security issue. It didn't sound to me like that from the text - to my paranoid mind this sounds like some process reading or writing some other process' address space and changing stuff arbitrarily. Maybe the text should be made more soothing so that no alarms go off while reading it :-). > Also, the reason it's "default y" is that the feature actually made it > in earlier (with no config option at all). I know, and it shouldn've been but it's too late now. > Now, I certainly agree that we could turn it off by default since > it's not that common, but at the same time none of your actual commit > comments make sense, so that would have to be fixed first. Sure, will do. -- Regards/Gruss, Boris. Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach GM: Alberto Bozzo Reg: Dornach, Landkreis Muenchen HRB Nr. 43632 WEEE Registernr: 129 19551 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/