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=-5.2 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 1D1E5C3A5A3 for ; Tue, 27 Aug 2019 08:56:40 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E69082173E for ; Tue, 27 Aug 2019 08:56:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E69082173E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:48414 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i2XHK-0007Y7-Sj for qemu-devel@archiver.kernel.org; Tue, 27 Aug 2019 04:56:38 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41442) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i2XG3-0006cV-7J for qemu-devel@nongnu.org; Tue, 27 Aug 2019 04:55:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i2XG1-0008RI-TC for qemu-devel@nongnu.org; Tue, 27 Aug 2019 04:55:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47292) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i2XFy-0008QQ-Ip; Tue, 27 Aug 2019 04:55:14 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B039110F23E7; Tue, 27 Aug 2019 08:55:13 +0000 (UTC) Received: from redhat.com (ovpn-112-56.ams2.redhat.com [10.36.112.56]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A9F645D70D; Tue, 27 Aug 2019 08:55:08 +0000 (UTC) Date: Tue, 27 Aug 2019 09:55:05 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Maxim Levitsky Message-ID: <20190827085505.GC16500@redhat.com> References: <20190814202219.1870-1-mlevitsk@redhat.com> <20190814202219.1870-6-mlevitsk@redhat.com> <6019b9e3-a4a6-4780-9652-f7c2bec024a5@redhat.com> <20190822104945.GJ3267@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.66]); Tue, 27 Aug 2019 08:55:13 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 05/13] qcrypto-luks: clear the masterkey and password before freeing them always X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Kevin Wolf , Fam Zheng , qemu-block@nongnu.org, Markus Armbruster , qemu-devel@nongnu.org, Nir Soffer , Stefan Hajnoczi , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Sun, Aug 25, 2019 at 06:31:02PM +0300, Maxim Levitsky wrote: > On Thu, 2019-08-22 at 13:56 +0300, Maxim Levitsky wrote: > > On Thu, 2019-08-22 at 11:49 +0100, Daniel P. Berrang=C3=A9 wrote: > > > On Tue, Aug 20, 2019 at 08:12:51PM +0200, Max Reitz wrote: > > > > On 14.08.19 22:22, Maxim Levitsky wrote: > > > > > While there are other places where these are still stored in me= mory, > > > > > this is still one less key material area that can be sniffed wi= th > > > > > various side channel attacks > > > > >=20 > > > > >=20 > > > > >=20 > > > >=20 > > > > (Many empty lines here) > > > >=20 > > > > > Signed-off-by: Maxim Levitsky > > > > > --- > > > > > crypto/block-luks.c | 52 +++++++++++++++++++++++++++++++++++++= +------- > > > > > 1 file changed, 44 insertions(+), 8 deletions(-) > > > >=20 > > > > Wouldn=E2=80=99t it make sense to introduce a dedicated function = for this? > > >=20 > > > Yes, it would. > > >=20 > > > In fact I have a series pending which bumps min glib and introduces > > > use of auto-free functions in this code. > > >=20 > > > It would be desirable to have a autp-free func for memset+free > > > so we can just declare the variable > > >=20 > > > q_autowipefree char *password =3D NULL; > > >=20 > > > and have it result in memset+free > > >=20 > >=20 > > That is perfect. > > When do you think you could post the series so that I could rebase > > on top of it? >=20 >=20 > I am thinking that I will keep my patch as is, just so that code is > consistent in memsetting the secrets (even though as Nir pointed out, > that these will be probably optimized away anyway). > And then when you send your patch you will just remove all > of these memsets. I'm fine with you continuing to use memset, since this is a pre-existing problem in the code that you are not making worse. We'll figure out the fix separately. Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|