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 2D426C433E0 for ; Wed, 20 May 2020 14:26:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00E2E207D3 for ; Wed, 20 May 2020 14:26:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728436AbgETO0E (ORCPT ); Wed, 20 May 2020 10:26:04 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33112 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727045AbgETOW1 (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 1jbPby-00037O-Ge; Wed, 20 May 2020 15:22:22 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jbPbx-007DVA-1q; 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 , "Jim Mattson" , "Marios Pomonis" , "Nick Finco" , "Andrew Honig" , "Paolo Bonzini" Date: Wed, 20 May 2020 15:14:46 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 78/99] KVM: x86: Protect ioapic_read_indirect() from 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 8c86405f606ca8508b8d9280680166ca26723695 upstream. This fixes a Spectre-v1/L1TF vulnerability in ioapic_read_indirect(). This function contains index computations based on the (attacker-controlled) IOREGSEL register. Fixes: a2c118bfab8b ("KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798)") 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: adjust filename] Signed-off-by: Ben Hutchings --- virt/kvm/ioapic.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include #include @@ -73,13 +74,14 @@ static unsigned long ioapic_read_indirec default: { u32 redir_index = (ioapic->ioregsel - 0x10) >> 1; - u64 redir_content; + u64 redir_content = ~0ULL; - if (redir_index < IOAPIC_NUM_PINS) - redir_content = - ioapic->redirtbl[redir_index].bits; - else - redir_content = ~0ULL; + if (redir_index < IOAPIC_NUM_PINS) { + u32 index = array_index_nospec( + redir_index, IOAPIC_NUM_PINS); + + redir_content = ioapic->redirtbl[index].bits; + } result = (ioapic->ioregsel & 0x1) ? (redir_content >> 32) & 0xffffffff :