From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linutronix.de (146.0.238.70:993) by crypto-ml.lab.linutronix.de with IMAP4-SSL for ; 12 Jun 2018 17:30:04 -0000 Received: from mx3-rdu2.redhat.com ([66.187.233.73] helo=mx1.redhat.com) by Galois.linutronix.de with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1fSn7L-0001yo-Bo for speck@linutronix.de; Tue, 12 Jun 2018 19:30:03 +0200 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 80E35402178A for ; Tue, 12 Jun 2018 17:29:56 +0000 (UTC) Received: from washington.bos.jonmasters.org (ovpn-124-149.rdu2.redhat.com [10.10.124.149]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5D2DB7C57 for ; Tue, 12 Jun 2018 17:29:56 +0000 (UTC) From: Jon Masters Subject: [MODERATED] FYI - Reading uncached memory Message-ID: Date: Tue, 12 Jun 2018 13:29:56 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit To: speck@linutronix.de List-ID: FYI Graz have been able to prove the Intel processors will allow speculative reads of /explicitly/ UC memory (e.g. marked in MTRR). I believe they actually use the QPI SAD table to determine what memory is speculation safe and what memory has side effects (i.e. if it's HA'able memory then it's deemed ok to rampantly speculate from it). Just in case anyone thought UC was safe against attacks. Jon. -- Computer Architect | Sent from my Fedora powered laptop