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=-2.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, T_DKIMWL_WL_HIGH,URIBL_BLOCKED,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 BF204C282CE for ; Tue, 4 Jun 2019 07:46:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9434124C99 for ; Tue, 4 Jun 2019 07:46:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559634388; bh=urzh/xDYEkBK23VDNPCtMBq+mujqArs+fOmkoAeT0H8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Pepy0rrkx+6kp0mb6Qp6vfzMYcMp26/yO0/pE7m02PGfwpjPIjmhZBRfy1VmcOxeS Xgagiaa2/Csoj0h0FPOUJVe6TVALK8vvcoMG8r1C5AVnVHW65fFwUKwnD+7doqeEP9 Zg/hvqqX6iIpHaKG6/MrnqjA/EY2Mka/yBtretc8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726697AbfFDHq1 (ORCPT ); Tue, 4 Jun 2019 03:46:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:41782 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726637AbfFDHq1 (ORCPT ); Tue, 4 Jun 2019 03:46:27 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 60D1B24C98; Tue, 4 Jun 2019 07:46:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559634386; bh=urzh/xDYEkBK23VDNPCtMBq+mujqArs+fOmkoAeT0H8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=E1bb0IxBNIZ594TsygB7KkKwwLXkgLaN46EykQ+vzsNlsRVtl1fxjCGoBOjfjuCdf MreLfF+CPghCIaZ9mzXHvlINJtqZfOUe+6ubKxE6/c2pj1tTBCu2VZQlZtgbn3EhYZ zgDmyq7jKZnn56rZjL7MM+LJSPEZmyrm02ns1heI= Date: Tue, 4 Jun 2019 09:46:24 +0200 From: Greg Kroah-Hartman To: Ard Biesheuvel Cc: Zubin Mithra , stable , groeck@chromium.org, Gen Zhang , Darren Hart , Andy Shevchenko , Thomas Gleixner , Ingo Molnar , Borislav Petkov Subject: Re: 4e78921ba4dd ("efi/x86/Add missing error handling to old_memmap 1:1 mapping code") Message-ID: <20190604074624.GA6840@kroah.com> References: <20190603223851.GA162395@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.0 (2019-05-25) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Jun 04, 2019 at 09:38:27AM +0200, Ard Biesheuvel wrote: > On Tue, 4 Jun 2019 at 00:38, Zubin Mithra wrote: > > > > Hello, > > > > CVE-2019-12380 was fixed in the upstream linux kernel with the commit :- > > * 4e78921ba4dd ("efi/x86/Add missing error handling to old_memmap 1:1 mapping code") > > > > Could the patch be applied in order to v4.19.y? > > > > Tests run: > > * Chrome OS tryjob > > > > Unless I am missing something, it seems to me that there is some > inflation going on when it comes to CVE number assignments. > > The code in question only affects systems that are explicitly booted > with efi=old_map, and the memory allocation occurs so early during the > boot sequence that even if we fail and handle it gracefully, it is > highly unlikely that we can get to a point where the system is usable > at all. > > Does Chrome OS boot in EFI mode? Does it use efi=old_map? Is the > kernel built with 5 level paging enabled? Did you run it on 5 level > paging hardware? > > Or is this just a tick the box exercise? > > Also, I am annoyed (does it show? :-)) that nobody mentioned the CVE > at any point when the patch was under review (not even privately) CVEs are almost always asked for _after_ the patch is merged, as the average fix-to-CVE request timeframe is -100 days. Also, for the kernel, CVEs almost mean nothing, so if this really isn't an issue, I'll not backport this. And I really doubt that any chromeos device has 5 level page tables just yet :) thanks, greg k-h