From patchwork Thu Oct 20 09:30:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 13012906 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 46107C433FE for ; Thu, 20 Oct 2022 09:31:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230383AbiJTJbi (ORCPT ); Thu, 20 Oct 2022 05:31:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230331AbiJTJbW (ORCPT ); Thu, 20 Oct 2022 05:31:22 -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 6E2F01552E3 for ; Thu, 20 Oct 2022 02:31:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666258277; 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=NO7cWLyVclWMKKTiYZzmBycykjfaB0P86+4KIdCX/tM=; b=Mv+5h66M3hORBahuXEiyOg1SJdRNH2XzNc5UICdsEqcO8HDWmp9FsEbUr2ac8vU1tP+prB YOPH26A3aE/pCRKjWRdF0FQTQNwuwpcJsxbqvsjXkOvpPjP9fZrSpW4QT9CltFJxO4BxDm 7IqtjW1ZieUE9cfNqXmszl2TaRRZW7w= 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-201-si_bzrwCPsqHWe6dAUaoPQ-1; Thu, 20 Oct 2022 05:31:11 -0400 X-MC-Unique: si_bzrwCPsqHWe6dAUaoPQ-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3B30138012DD; Thu, 20 Oct 2022 09:31:11 +0000 (UTC) Received: from localhost.localdomain (ovpn-192-51.brq.redhat.com [10.40.192.51]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6D32649BB60; Thu, 20 Oct 2022 09:31:08 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Paolo Bonzini , Borislav Petkov , Ingo Molnar , Sean Christopherson , x86@kernel.org, Thomas Gleixner , Dave Hansen , "H. Peter Anvin" , Maxim Levitsky , stable@vger.kernel.org Subject: [PATCH 2/4] KVM: x86: nSVM: harden svm_free_nested against freeing vmcb02 while still in use Date: Thu, 20 Oct 2022 12:30:53 +0300 Message-Id: <20221020093055.224317-3-mlevitsk@redhat.com> In-Reply-To: <20221020093055.224317-1-mlevitsk@redhat.com> References: <20221020093055.224317-1-mlevitsk@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 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 4c620999d230a5..b02a3a1792f194 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1125,6 +1125,9 @@ 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;