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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 44C1BC352A3 for ; Mon, 10 Feb 2020 12:49:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1439320842 for ; Mon, 10 Feb 2020 12:49:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581338967; bh=XKdpO/y2Hk77eZTPZ2JTfZ3rGi2Q8YTeuWqG9Y6WOhk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GZcqZBXDKh+ApaA45g95y8Iq56VGJN2B1Ich/KJZ968CSMeMdDjTFHpv+GxpLLg8L n0wSWNGBt1ASSjzehacPf/qNVNmWTWzgE1UWaP0SjrM9F0Nco4vOeWbHTaFSIkbAZO c98Tkb6BJSnpLHAPGZHCfuzIcZJhIEmqsUp78ddE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730822AbgBJMpy (ORCPT ); Mon, 10 Feb 2020 07:45:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:42698 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728156AbgBJMlJ (ORCPT ); Mon, 10 Feb 2020 07:41:09 -0500 Received: from localhost (unknown [209.37.97.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 53BF920733; Mon, 10 Feb 2020 12:41:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581338468; bh=XKdpO/y2Hk77eZTPZ2JTfZ3rGi2Q8YTeuWqG9Y6WOhk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vvQNzW1UL0GBR8P66E+yukQBA+Hb0EAWqFb2UXqB/Rsf0x1rXKX+URXfc48HE+qLz k/nn6vuZAQOns7yGpdV+jWNmoXmGAmN3jOnVu6hlxbT4kZXX3p9ToupnDaukpYltKB QYjIkl+h2mSAE2MwLUm7SZmGyYY7GWtgdn83OcJE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nick Finco , Marios Pomonis , Andrew Honig , Jim Mattson , Paolo Bonzini Subject: [PATCH 5.5 231/367] KVM: x86: Protect kvm_lapic_reg_write() from Spectre-v1/L1TF attacks Date: Mon, 10 Feb 2020 04:32:24 -0800 Message-Id: <20200210122445.594617647@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200210122423.695146547@linuxfoundation.org> References: <20200210122423.695146547@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marios Pomonis commit 4bf79cb089f6b1c6c632492c0271054ce52ad766 upstream. This fixes a Spectre-v1/L1TF vulnerability in kvm_lapic_reg_write(). This function contains index computations based on the (attacker-controlled) MSR number. Fixes: 0105d1a52640 ("KVM: x2apic interface to lapic") Signed-off-by: Nick Finco Signed-off-by: Marios Pomonis Reviewed-by: Andrew Honig Cc: stable@vger.kernel.org Reviewed-by: Jim Mattson Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/lapic.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1963,15 +1963,20 @@ int kvm_lapic_reg_write(struct kvm_lapic case APIC_LVTTHMR: case APIC_LVTPC: case APIC_LVT1: - case APIC_LVTERR: + case APIC_LVTERR: { /* TODO: Check vector */ + size_t size; + u32 index; + if (!kvm_apic_sw_enabled(apic)) val |= APIC_LVT_MASKED; - - val &= apic_lvt_mask[(reg - APIC_LVTT) >> 4]; + size = ARRAY_SIZE(apic_lvt_mask); + index = array_index_nospec( + (reg - APIC_LVTT) >> 4, size); + val &= apic_lvt_mask[index]; kvm_lapic_set_reg(apic, reg, val); - break; + } case APIC_LVTT: if (!kvm_apic_sw_enabled(apic))