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=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 79DB3C43461 for ; Tue, 8 Sep 2020 17:29:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 42AE820738 for ; Tue, 8 Sep 2020 17:29:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599586179; bh=Mjj6isNwDffeAOtdV0P2jtlwiRjss5m7SJ9I3ziDE20=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=MyEL7KwTVX4dQ8PVv67WaqnoawB5zRZADDEXlaroNQOgex9qx1hrE2uAEptrVa9Zn YF4tI1z3lnAD2yEvb7ZSJU54AmC9MNJfeD0bQj0tilzDkx4+ompN5uKsngi39laEJj LoiBECoO5XSWCvmtNm1QBEcUwJ1HPL18P2d0dsf0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732047AbgIHR3c (ORCPT ); Tue, 8 Sep 2020 13:29:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:58192 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731548AbgIHQQJ (ORCPT ); Tue, 8 Sep 2020 12:16:09 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CE40222597; Tue, 8 Sep 2020 13:03:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599570205; bh=Mjj6isNwDffeAOtdV0P2jtlwiRjss5m7SJ9I3ziDE20=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tYB4yF899rvv7EuFVWA4A63efOaGo9YF6nOXNCWrneHHV+LlFHuwCpjtJNa/3tPLP mYVqIC/HBmH9ce9qyRQMgITuyG1GepgzcxT/XXbGDNgAOhojhyPcsMAZnVYZopJqK/ WYdl2OUrhmAhqd5BR+BEx/6/uKR8OVoajwV9XOWQ= Date: Tue, 8 Sep 2020 15:03:37 +0200 From: Greg KH To: Ajay Kaher Cc: sashal@kernel.org, alex.williamson@redhat.com, cohuck@redhat.com, peterx@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, srivatsab@vmware.com, srivatsa@csail.mit.edu, vsirnapalli@vmware.com Subject: Re: [PATCH v4.9.y 0/3] vfio: Fix for CVE-2020-12888 Message-ID: <20200908130337.GB3075407@kroah.com> References: <1599510917-23734-1-git-send-email-akaher@vmware.com> <1599510917-23734-4-git-send-email-akaher@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1599510917-23734-4-git-send-email-akaher@vmware.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 08, 2020 at 02:05:17AM +0530, Ajay Kaher wrote: > CVE-2020-12888 Kernel: vfio: access to disabled MMIO space of some > devices may lead to DoS scenario > > The VFIO modules allow users (guest VMs) to enable or disable access to the > devices' MMIO memory address spaces. If a user attempts to access (read/write) > the devices' MMIO address space when it is disabled, some h/w devices issue an > interrupt to the CPU to indicate a fatal error condition, crashing the system. > This flaw allows a guest user or process to crash the host system resulting in > a denial of service. > > Patch 1/ is to force the user fault if PFNMAP vma might be DMA mapped > before user access. > > Patch 2/ setup a vm_ops handler to support dynamic faulting instead of calling > remap_pfn_range(). Also provides a list of vmas actively mapping the area which > can later use to invalidate those mappings. > > Patch 3/ block the user from accessing memory spaces which is disabled by using > new vma list support to zap, or invalidate, those memory mappings in order to > force them to be faulted back in on access. > > Upstreamed patches link: > https://lore.kernel.org/kvm/158871401328.15589.17598154478222071285.stgit@gimli.home > > [PATCH v4.9.y 1/3]: > Backporting of upsream commit 41311242221e: > vfio/type1: Support faulting PFNMAP vmas > > [PATCH v4.9.y 2/3]: > Backporting of upsream commit 11c4cd07ba11: > vfio-pci: Fault mmaps to enable vma tracking > > [PATCH v4.9.y 3/3]: > Backporting of upsream commit abafbc551fdd: > vfio-pci: Invalidate mmaps and block MMIO access on disabled memory All now queued up, thanks. greg k-h