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=-18.8 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 7B0BCC43470 for ; Mon, 19 Apr 2021 13:30:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 640C861027 for ; Mon, 19 Apr 2021 13:30:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242709AbhDSN3i (ORCPT ); Mon, 19 Apr 2021 09:29:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:54232 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241553AbhDSNUy (ORCPT ); Mon, 19 Apr 2021 09:20:54 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 35B2E613D8; Mon, 19 Apr 2021 13:17:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1618838239; bh=OxV01kUvNRgHcTAQ6TWVRP8AMkFSj9AW+I1Xcfvm8vA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z+F7UgAA53dvLUlDv2LQITuY9joLPg8m82ea+138zZ3EP+E/8WiGB0/hgZKDurW/D 4j1vWdISjT8oap5yRwbl9E76BHpBYAtYACpYtFY4Cjsqn4aCWnNLN+NhLnx+2q1LLX XGl5RYPKGJKgRQQ1A6c5PgxTq0dlNQ2L9dkGrwSU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Reiji Watanabe , Jim Mattson , Paolo Bonzini , Sasha Levin Subject: [PATCH 5.10 094/103] KVM: VMX: Dont use vcpu->run->internal.ndata as an array index Date: Mon, 19 Apr 2021 15:06:45 +0200 Message-Id: <20210419130531.017872691@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210419130527.791982064@linuxfoundation.org> References: <20210419130527.791982064@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: Reiji Watanabe [ Upstream commit 04c4f2ee3f68c9a4bf1653d15f1a9a435ae33f7a ] __vmx_handle_exit() uses vcpu->run->internal.ndata as an index for an array access. Since vcpu->run is (can be) mapped to a user address space with a writer permission, the 'ndata' could be updated by the user process at anytime (the user process can set it to outside the bounds of the array). So, it is not safe that __vmx_handle_exit() uses the 'ndata' that way. Fixes: 1aa561b1a4c0 ("kvm: x86: Add "last CPU" to some KVM_EXIT information") Signed-off-by: Reiji Watanabe Reviewed-by: Jim Mattson Message-Id: <20210413154739.490299-1-reijiw@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/vmx/vmx.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 0b229282dd50..f8835cabf29f 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6006,19 +6006,19 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath) exit_reason.basic != EXIT_REASON_PML_FULL && exit_reason.basic != EXIT_REASON_APIC_ACCESS && exit_reason.basic != EXIT_REASON_TASK_SWITCH)) { + int ndata = 3; + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_DELIVERY_EV; - vcpu->run->internal.ndata = 3; vcpu->run->internal.data[0] = vectoring_info; vcpu->run->internal.data[1] = exit_reason.full; vcpu->run->internal.data[2] = vcpu->arch.exit_qualification; if (exit_reason.basic == EXIT_REASON_EPT_MISCONFIG) { - vcpu->run->internal.ndata++; - vcpu->run->internal.data[3] = + vcpu->run->internal.data[ndata++] = vmcs_read64(GUEST_PHYSICAL_ADDRESS); } - vcpu->run->internal.data[vcpu->run->internal.ndata++] = - vcpu->arch.last_vmentry_cpu; + vcpu->run->internal.data[ndata++] = vcpu->arch.last_vmentry_cpu; + vcpu->run->internal.ndata = ndata; return 0; } -- 2.30.2