From patchwork Thu Nov 3 13:57:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 13030033 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77B8FC4332F for ; Thu, 3 Nov 2022 13:59:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231682AbiKCN7A (ORCPT ); Thu, 3 Nov 2022 09:59:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231419AbiKCN6y (ORCPT ); Thu, 3 Nov 2022 09:58:54 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D4F916580 for ; Thu, 3 Nov 2022 06:57:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667483873; 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: in-reply-to:in-reply-to:references:references; bh=ZLirfmVsMl7Z8L0J+XcE1Zsp+gCHNtOKzvKZLLJ8RdA=; b=PliTro3xAmx+SWUzrtL8cosxDFNc06zRCkRtjqpzztYrEyqB5HDboxOdb7dYtTigS8Vb0q OrmHmBvYadTnkp/+glHH3cZtzAn+KeZFXM38pb+8i/sRauMZLtkG+rVyzrzmFnBkXR5lN8 cdGNRV7cKze9AVNmxKmRme814E+zpoo= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-271-J74K2mJrOAGRjdR_58cgEA-1; Thu, 03 Nov 2022 09:57:50 -0400 X-MC-Unique: J74K2mJrOAGRjdR_58cgEA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2F6B33C0DDD0; Thu, 3 Nov 2022 13:57:49 +0000 (UTC) Received: from amdlaptop.tlv.redhat.com (dhcp-4-238.tlv.redhat.com [10.35.4.238]) by smtp.corp.redhat.com (Postfix) with ESMTP id C1F3040C2087; Thu, 3 Nov 2022 13:57:44 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: Paolo Bonzini , "H. Peter Anvin" , Shuah Khan , Yang Zhong , Wei Wang , Colton Lewis , Sean Christopherson , Jim Mattson , Chenyi Qiang , Borislav Petkov , linux-kernel@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Dave Hansen , Ingo Molnar , David Matlack , Peter Xu , Maxim Levitsky , linux-kselftest@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 2/9] KVM: x86: nSVM: harden svm_free_nested against freeing vmcb02 while still in use Date: Thu, 3 Nov 2022 15:57:29 +0200 Message-Id: <20221103135736.42295-3-mlevitsk@redhat.com> In-Reply-To: <20221103135736.42295-1-mlevitsk@redhat.com> References: <20221103135736.42295-1-mlevitsk@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Make sure that KVM uses vmcb01 before freeing nested state, and warn if that is not the case. This is a minimal fix for CVE-2022-3344 making the kernel print a warning instead of a kernel panic. Cc: stable@vger.kernel.org Signed-off-by: Maxim Levitsky --- arch/x86/kvm/svm/nested.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index b258d6988f5dde..b74da40c1fc40c 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1126,6 +1126,9 @@ void svm_free_nested(struct vcpu_svm *svm) if (!svm->nested.initialized) return; + if (WARN_ON_ONCE(svm->vmcb != svm->vmcb01.ptr)) + svm_switch_vmcb(svm, &svm->vmcb01); + svm_vcpu_free_msrpm(svm->nested.msrpm); svm->nested.msrpm = NULL;