From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753084Ab0AGPxD (ORCPT ); Thu, 7 Jan 2010 10:53:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752859Ab0AGPxB (ORCPT ); Thu, 7 Jan 2010 10:53:01 -0500 Received: from mail-ew0-f219.google.com ([209.85.219.219]:59622 "EHLO mail-ew0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752079Ab0AGPxA (ORCPT ); Thu, 7 Jan 2010 10:53:00 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject :content-type:content-transfer-encoding; b=RZiCsAVaRGht7AZUHB/5WIRc3QqTHAm0s10Fyi1IIjLrJCFnKVK/rI8nruzuC6Ffn7 6uVibhFkD2O2+SQr6YNzSXqRiNEXNKp5Dk6+mV6nvXKoqtbZBWERryHD7YfJreuE1Hv4 HxZBfCej2HGejD3uJbgyQ+JjzP1PBropx0KJM= Message-ID: <4B460441.6090602@gmail.com> Date: Thu, 07 Jan 2010 16:56:49 +0100 From: Roel Kluin User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-4.fc12 Thunderbird/3.0 MIME-Version: 1.0 To: Avi Kivity , Marcelo Tosatti , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] kvm: don't treat NULL parent_pte as multimapped in mmu_parent_walk() Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If a kvm_mmu_page is not multimapped but parent_pte is NULL don't treat it as multimapped and dereference it. Signed-off-by: Roel Kluin --- This wasn't tested and maybe I misunderstood so please review. diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 4c3e5b2..eb17287 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1031,10 +1031,12 @@ static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, struct kvm_mmu_page *parent_sp; int i; - if (!sp->multimapped && sp->parent_pte) { - parent_sp = page_header(__pa(sp->parent_pte)); - fn(vcpu, parent_sp); - mmu_parent_walk(vcpu, parent_sp, fn); + if (!sp->multimapped) { + if (sp->parent_pte) { + parent_sp = page_header(__pa(sp->parent_pte)); + fn(vcpu, parent_sp); + mmu_parent_walk(vcpu, parent_sp, fn); + } return; } hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)