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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 4ED96C4320A for ; Mon, 16 Aug 2021 14:02:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33BBA60F21 for ; Mon, 16 Aug 2021 14:02:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231841AbhHPODV (ORCPT ); Mon, 16 Aug 2021 10:03:21 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:46185 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231718AbhHPODT (ORCPT ); Mon, 16 Aug 2021 10:03:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1629122567; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=W0UeGbAy2o6lV9kmLNnb/cV+5YrfIcgJb8Ddk815S4I=; b=PP5gunHTc5aOcCQ/4fkgcA4r2pBXHzYyWG1u/Oyq8OMaKh3LUpyD+idOaaRn4cvaHoBrwl LwC4f4dZkTcBLv+Wy0NBkmxJANU3YxBonnnPJ1mEuIX16uxj/H8mkouPLvCGHmZg11mS2N tLiNT9OJkr6vtmGg34T0aG4apYGK7cA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-392-3Y2yI340OW-3wb_5Cg-GGA-1; Mon, 16 Aug 2021 10:02:45 -0400 X-MC-Unique: 3Y2yI340OW-3wb_5Cg-GGA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id F14F2100F768; Mon, 16 Aug 2021 14:02:44 +0000 (UTC) Received: from avogadro.lan (unknown [10.39.192.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id A360C5C23A; Mon, 16 Aug 2021 14:02:43 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: stable@vger.kernel.org, Maxim Levitsky Subject: [PATCH 4.19.y] KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl (CVE-2021-3653) Date: Mon, 16 Aug 2021 16:02:30 +0200 Message-Id: <20210816140240.11399-2-pbonzini@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Maxim Levitsky [ upstream commit 0f923e07124df069ba68d8bb12324398f4b6b709 ] * Invert the mask of bits that we pick from L2 in nested_vmcb02_prepare_control * Invert and explicitly use VIRQ related bits bitmask in svm_clear_vintr This fixes a security issue that allowed a malicious L1 to run L2 with AVIC enabled, which allowed the L2 to exploit the uninitialized and enabled AVIC to read/write the host physical memory at some offsets. Fixes: 3d6368ef580a ("KVM: SVM: Add VMRUN handler") Signed-off-by: Maxim Levitsky Signed-off-by: Paolo Bonzini --- The above upstream SHA1 is still on its way to Linus arch/x86/include/asm/svm.h | 2 ++ arch/x86/kvm/svm.c | 15 ++++++++------- 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index 93b462e48067..b6dedf6c835c 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -118,6 +118,8 @@ struct __attribute__ ((__packed__)) vmcb_control_area { #define V_IGN_TPR_SHIFT 20 #define V_IGN_TPR_MASK (1 << V_IGN_TPR_SHIFT) +#define V_IRQ_INJECTION_BITS_MASK (V_IRQ_MASK | V_INTR_PRIO_MASK | V_IGN_TPR_MASK) + #define V_INTR_MASKING_SHIFT 24 #define V_INTR_MASKING_MASK (1 << V_INTR_MASKING_SHIFT) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index bd463d684237..5ddf63896d01 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1394,12 +1394,7 @@ static __init int svm_hardware_setup(void) } } - if (vgif) { - if (!boot_cpu_has(X86_FEATURE_VGIF)) - vgif = false; - else - pr_info("Virtual GIF supported\n"); - } + vgif = false; /* Disabled for CVE-2021-3653 */ return 0; @@ -3590,7 +3590,13 @@ static void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa, svm->nested.intercept = nested_vmcb->control.intercept; svm_flush_tlb(&svm->vcpu, true); - svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl | V_INTR_MASKING_MASK; + + svm->vmcb->control.int_ctl &= + V_INTR_MASKING_MASK | V_GIF_ENABLE_MASK | V_GIF_MASK; + + svm->vmcb->control.int_ctl |= nested_vmcb->control.int_ctl & + (V_TPR_MASK | V_IRQ_INJECTION_BITS_MASK); + if (nested_vmcb->control.int_ctl & V_INTR_MASKING_MASK) svm->vcpu.arch.hflags |= HF_VINTR_MASK; else -- 2.26.3