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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 03709C64EBC for ; Thu, 4 Oct 2018 08:43:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB8F22147C for ; Thu, 4 Oct 2018 08:43:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=8bytes.org header.i=@8bytes.org header.b="Nn22gchn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB8F22147C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727536AbeJDPfa (ORCPT ); Thu, 4 Oct 2018 11:35:30 -0400 Received: from 8bytes.org ([81.169.241.247]:33924 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726857AbeJDPfa (ORCPT ); Thu, 4 Oct 2018 11:35:30 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id B2E1E345; Thu, 4 Oct 2018 10:43:18 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=8bytes.org; s=mail-1; t=1538642598; bh=Dzfuf26mksisVVIFmA4NBA/y4HXmc3fmhZ+czV6QpNY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Nn22gchnUhc8lyRznvtNoXj5vHJAQFJ6YZ2kUmA09ht8JFV/ySM83GgvPiXvZcM5b 5OQ5g+rpSIY0snAeyRaaDTNtIPx7wmmUjLCg/003rEgINDoKkJOcUOooz0cb3dIdas s+6hRQzASnOl1654km8RRxQaZmAPs62jM2SeXUkAp/j0MnhGatu/5tq8JM9u5M3FBg ZRnVc2s6lo9yXcUKq7JOWAjjCIod0uJJ/N6jVYCFUBgW3iFasrdoRmRTnO+MzFRdHH toT9MPwSyp6Zafr7ZzqYZElfEoa0eVIhWFKAE9nxw3Ns6fWgH337YKq0qH0euWf59H ch/ZFmHOLOzbA== Date: Thu, 4 Oct 2018 10:43:18 +0200 From: Joerg Roedel To: Borislav Petkov Cc: Thomas Gleixner , Paul Menzel , linux-mm@kvack.org, x86@kernel.org, lkml Subject: Re: x86/mm: Found insecure W+X mapping at address (ptrval)/0xc00a0000 Message-ID: <20181004084318.GB3630@8bytes.org> References: <0922cc1b-ed51-06e9-df81-57fd5aa8e7de@molgen.mpg.de> <20181003212255.GB28361@zn.tnic> <20181004080321.GA3630@8bytes.org> <20181004081429.GB1864@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181004081429.GB1864@zn.tnic> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 04, 2018 at 10:14:38AM +0200, Borislav Petkov wrote: > So looking at this, BIOS_BEGIN and BIOS_END is the same range as the ISA > range: > > #define ISA_START_ADDRESS 0x000a0000 > #define ISA_END_ADDRESS 0x00100000 > > #define BIOS_BEGIN 0x000a0000 > #define BIOS_END 0x00100000 > > > and I did try marking the ISA range RO in mark_rodata_ro() but the > machine wouldn't boot after. So I'm guessing BIOS needs to write there > some crap. Yeah, that's what I also found out back then, the region needs to be WX. So we can either leave with the warning, as we know it is harmless and where it comes from or implement an exception in the checking code for that region. Regards, Joerg