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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 768FFC3A59E for ; Wed, 21 Aug 2019 23:12:49 +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 4B5AA2332A for ; Wed, 21 Aug 2019 23:12:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4B5AA2332A 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]:36988 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i0Zma-0001TN-DX for qemu-devel@archiver.kernel.org; Wed, 21 Aug 2019 19:12:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47374) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i0Zlg-0000aQ-FA for qemu-devel@nongnu.org; Wed, 21 Aug 2019 19:11:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i0Zlf-0007zM-A9 for qemu-devel@nongnu.org; Wed, 21 Aug 2019 19:11:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36168) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i0Zlc-0007xo-Vm; Wed, 21 Aug 2019 19:11:49 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F06DB10F23E1; Wed, 21 Aug 2019 23:11:47 +0000 (UTC) Received: from maximlenovopc.usersys.redhat.com (unknown [10.35.206.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id 859BC60C05; Wed, 21 Aug 2019 23:11:43 +0000 (UTC) Message-ID: From: Maxim Levitsky To: Nir Soffer Date: Thu, 22 Aug 2019 02:11:42 +0300 In-Reply-To: References: <20190814202219.1870-1-mlevitsk@redhat.com> <20190814202219.1870-6-mlevitsk@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.66]); Wed, 21 Aug 2019 23:11:48 +0000 (UTC) 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] [Qemu-block] [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: , Cc: Kevin Wolf , Fam Zheng , "Daniel P. =?ISO-8859-1?Q?Berrang=E9?=" , qemu-block@nongnu.org, QEMU Developers , Markus Armbruster , Stefan Hajnoczi , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 2019-08-22 at 02:01 +0300, Nir Soffer wrote: > On Wed, Aug 14, 2019, 23:23 Maxim Levitsky wrote: > > > While there are other places where these are still stored in memory, > > this is still one less key material area that can be sniffed with > > various side channel attacks > > > > > > > > Signed-off-by: Maxim Levitsky > > --- > > crypto/block-luks.c | 52 ++++++++++++++++++++++++++++++++++++++------- > > 1 file changed, 44 insertions(+), 8 deletions(-) > > > > diff --git a/crypto/block-luks.c b/crypto/block-luks.c > > index e1a4df94b7..336e633df4 100644 > > --- a/crypto/block-luks.c > > +++ b/crypto/block-luks.c > > @@ -1023,8 +1023,18 @@ qcrypto_block_luks_load_key(QCryptoBlock *block, > > cleanup: > > qcrypto_ivgen_free(ivgen); > > qcrypto_cipher_free(cipher); > > - g_free(splitkey); > > - g_free(possiblekey); > > + > > + if (splitkey) { > > + memset(splitkey, 0, splitkeylen); > > > > I think we need memset_s() or similar replacement, see > > https://www.cryptologie.net/article/419/zeroing-memory-compiler-optimizations-and-memset_s/ You raise a very very good point here! Thanks!! Best regards, Maxim Levitsky