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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 92BE0C433DF for ; Wed, 20 May 2020 14:22:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64266205CB for ; Wed, 20 May 2020 14:22:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727918AbgETOWy (ORCPT ); Wed, 20 May 2020 10:22:54 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33090 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727034AbgETOW1 (ORCPT ); Wed, 20 May 2020 10:22:27 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jbPbz-00037g-QF; Wed, 20 May 2020 15:22:23 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jbPbw-007DV5-Vk; Wed, 20 May 2020 15:22:21 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Paolo Bonzini" , "Andrew Honig" , "Nick Finco" , "Marios Pomonis" , "Jim Mattson" Date: Wed, 20 May 2020 15:14:45 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 77/99] KVM: x86: Refactor picdev_write() to prevent Spectre-v1/L1TF attacks In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.84-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Marios Pomonis commit 14e32321f3606e4b0970200b6e5e47ee6f1e6410 upstream. This fixes a Spectre-v1/L1TF vulnerability in picdev_write(). It replaces index computations based on the (attacked-controlled) port number with constants through a minor refactoring. Fixes: 85f455f7ddbe ("KVM: Add support for in-kernel PIC emulation") Signed-off-by: Nick Finco Signed-off-by: Marios Pomonis Reviewed-by: Andrew Honig Reviewed-by: Jim Mattson Signed-off-by: Paolo Bonzini [bwh: Backported to 3.16: pic_{,un}lock() are called outside the switch] Signed-off-by: Ben Hutchings --- --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -486,9 +486,11 @@ static int picdev_write(struct kvm_pic * switch (addr) { case 0x20: case 0x21: + pic_ioport_write(&s->pics[0], addr, data); + break; case 0xa0: case 0xa1: - pic_ioport_write(&s->pics[addr >> 7], addr, data); + pic_ioport_write(&s->pics[1], addr, data); break; case 0x4d0: case 0x4d1: