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=-20.2 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, 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 9FB55C6377B for ; Mon, 19 Jul 2021 17:58:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D9986113C for ; Mon, 19 Jul 2021 17:58:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355549AbhGSRPJ (ORCPT ); Mon, 19 Jul 2021 13:15:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:35796 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236731AbhGSPhX (ORCPT ); Mon, 19 Jul 2021 11:37:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AAA7F610FB; Mon, 19 Jul 2021 16:17:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626711471; bh=zmOByIB8qMmfz787nQbKHYGg6IpOuowegXQdddHUonE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vR6/u7RE7OUM0zbORhJAW141pTA1zIT7maZSWFkbsdi7yqESWD4Xnf3MMZx/EpJ+P 8kznpARsE/y9ReSw4UblWO2no4RZbKrPGaUnwvTuUzsBw1T7/TkwaglaHTNI34N4uQ grtTH2RNo0SOWa20RGYICp5D2U9DVLl1NvFvIhbA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vitaly Kuznetsov , Maxim Levitsky , Paolo Bonzini Subject: [PATCH 5.12 007/292] KVM: nSVM: Check the value written to MSR_VM_HSAVE_PA Date: Mon, 19 Jul 2021 16:51:09 +0200 Message-Id: <20210719144942.758030410@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144942.514164272@linuxfoundation.org> References: <20210719144942.514164272@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vitaly Kuznetsov commit fce7e152ffc8f89d02a80617b16c7aa1527847c8 upstream. APM states that #GP is raised upon write to MSR_VM_HSAVE_PA when the supplied address is not page-aligned or is outside of "maximum supported physical address for this implementation". page_address_valid() check seems suitable. Also, forcefully page-align the address when it's written from VMM. Signed-off-by: Vitaly Kuznetsov Message-Id: <20210628104425.391276-2-vkuznets@redhat.com> Cc: stable@vger.kernel.org Reviewed-by: Maxim Levitsky [Add comment about behavior for host-provided values. - Paolo] Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm/svm.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2982,7 +2982,16 @@ static int svm_set_msr(struct kvm_vcpu * svm_disable_lbrv(vcpu); break; case MSR_VM_HSAVE_PA: - svm->nested.hsave_msr = data; + /* + * Old kernels did not validate the value written to + * MSR_VM_HSAVE_PA. Allow KVM_SET_MSR to set an invalid + * value to allow live migrating buggy or malicious guests + * originating from those kernels. + */ + if (!msr->host_initiated && !page_address_valid(vcpu, data)) + return 1; + + svm->nested.hsave_msr = data & PAGE_MASK; break; case MSR_VM_CR: return svm_set_vm_cr(vcpu, data);