From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-la0-f50.google.com (mail-la0-f50.google.com [209.85.215.50]) by kanga.kvack.org (Postfix) with ESMTP id 9DB2D6B0038 for ; Thu, 19 Mar 2015 09:24:44 -0400 (EDT) Received: by lagg8 with SMTP id g8so61979117lag.1 for ; Thu, 19 Mar 2015 06:24:43 -0700 (PDT) Received: from forward-corp1g.mail.yandex.net (forward-corp1g.mail.yandex.net. [95.108.253.251]) by mx.google.com with ESMTPS id uq10si976389lbb.86.2015.03.19.06.24.42 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 19 Mar 2015 06:24:42 -0700 (PDT) Message-ID: <550ACE17.9040600@yandex-team.ru> Date: Thu, 19 Mar 2015 16:24:39 +0300 From: Konstantin Khlebnikov MIME-Version: 1.0 Subject: Re: [PATCH RFC] mm: protect suid binaries against rowhammer with copy-on-read mappings References: <20150318083040.7838.76933.stgit@zurg> <20150318095702.GA2479@node.dhcp.inet.fi> <5509644C.40502@yandex-team.ru> <550AC958.9010502@suse.cz> In-Reply-To: <550AC958.9010502@suse.cz> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka , "Kirill A. Shutemov" , Konstantin Khlebnikov Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Andrew Morton , Linus Torvalds , Andy Lutomirski On 19.03.2015 16:04, Vlastimil Babka wrote: > On 03/18/2015 12:41 PM, Konstantin Khlebnikov wrote: >> On 18.03.2015 12:57, Kirill A. Shutemov wrote: >>> >>> I don't think it worth it. The only right way to fix the problem is ECC >>> memory. >>> >> >> ECC seems good protection until somebody figure out how to break it too. > > I doubt that kind of attitude can get us very far. If we can't trust the > hardware, we lose sooner or later. > Obviously ECC was designed for protecting against cosmic rays which flips several bits. If attacker modifies whole cacheline he can chose value which have the same ECC. I hope next generation of DRAM (or PRAM) wouldn't be affected. Software solution is possible: we can put untrusted applications into special ghetto memory zone. This is relatively easy for virtual machines. And it seems might work for normal tasks too (page-cache pages should be doubled or handled in the way similar to copy-on-read from that patch). -- Konstantin -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org