From patchwork Mon Aug 16 14:02:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 498709 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=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 E32B3C4320A for ; Mon, 16 Aug 2021 14:02:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C6FAA60F21 for ; Mon, 16 Aug 2021 14:02:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236242AbhHPODY (ORCPT ); Mon, 16 Aug 2021 10:03:24 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:51602 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231959AbhHPODX (ORCPT ); Mon, 16 Aug 2021 10:03:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1629122571; 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=z7bgEj7pf0qR83AdLpsnYV0+Zd/w/LzG4EMhM5bKSNM=; b=UUBR68Fll98eW26sINAbnkuTfIP3PrfQeQxZORu7cDAZ5czeM+EEVvBjeA3lG1J0Sj04qK PMYMZZdqKjdKO32TOwQMu1dcYHUpqemk3yAclPM7hHaM+zWg6fOxzR5NB9Aw2bQr+CqOIC vrh4dUc+UVfZkgXYWAtCrOZqNvP0Azg= 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-557-h1L_Uep4MDanTClylLgAww-1; Mon, 16 Aug 2021 10:02:49 -0400 X-MC-Unique: h1L_Uep4MDanTClylLgAww-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 2FA0D1853027; Mon, 16 Aug 2021 14:02:48 +0000 (UTC) Received: from avogadro.lan (unknown [10.39.192.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id E7E652CD33; Mon, 16 Aug 2021 14:02:46 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: stable@vger.kernel.org, Maxim Levitsky Subject: [PATCH 4.9.y] KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl (CVE-2021-3653) Date: Mon, 16 Aug 2021 16:02:32 +0200 Message-Id: <20210816140240.11399-4-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: stable@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 | 6 +++++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index 14824fc78f7e..509b9f3307e4 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -113,6 +113,8 @@ 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 cbc7f177bbd8..03fdeab057d2 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3048,7 +3048,11 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm) svm->nested.intercept = nested_vmcb->control.intercept; svm_flush_tlb(&svm->vcpu); - svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl | V_INTR_MASKING_MASK; + svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl & + (V_TPR_MASK | V_IRQ_INJECTION_BITS_MASK); + + svm->vmcb->control.int_ctl |= V_INTR_MASKING_MASK; + if (nested_vmcb->control.int_ctl & V_INTR_MASKING_MASK) svm->vcpu.arch.hflags |= HF_VINTR_MASK; else