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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 4A65EC38145 for ; Tue, 6 Sep 2022 09:53:41 +0000 (UTC) Received: from localhost ([::1]:51436 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oVVH2-00062c-Ae for qemu-devel@archiver.kernel.org; Tue, 06 Sep 2022 05:53:40 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34508) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oVUZy-0005m4-8q for qemu-devel@nongnu.org; Tue, 06 Sep 2022 05:09:11 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:46071) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oVUZv-00029c-SE for qemu-devel@nongnu.org; Tue, 06 Sep 2022 05:09:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1662455345; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YEjZ/T0ghzKpuF0oXKubkqWEaEbFCF+OPb5bII70OZQ=; b=EZ6ZZ9aDTb3oLFGRrp2Dl1QGib6DtoG7Y8162Th3NPzqTAo67tL/NRrR8xIinaom9wUU3y Cvfum1lxAZWdrkkHIe29R2wC0l8YrknwpJgEMAm2Vi/w67eqMUAElHDsoTZk7Wbmin2GXU tFiaYCLIH+lq4A76BsUzQ0yigl7BnyY= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-597-jPAdOmcROnGp-5JCbE20yg-1; Tue, 06 Sep 2022 05:09:04 -0400 X-MC-Unique: jPAdOmcROnGp-5JCbE20yg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B38673C01DF8 for ; Tue, 6 Sep 2022 09:09:03 +0000 (UTC) Received: from localhost (unknown [10.39.193.165]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7600EC15BB3; Tue, 6 Sep 2022 09:09:03 +0000 (UTC) Date: Tue, 6 Sep 2022 10:09:02 +0100 From: "Richard W.M. Jones" To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= Cc: qemu-devel@nongnu.org Subject: Re: [PATCH 02/11] crypto: enforce that LUKS stripes is always a fixed value Message-ID: <20220906090902.GK7484@redhat.com> References: <20220906084147.1423045-1-berrange@redhat.com> <20220906084147.1423045-3-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220906084147.1423045-3-berrange@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; envelope-from=rjones@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Sep 06, 2022 at 09:41:38AM +0100, Daniel P. Berrangé wrote: > Although the LUKS stripes are encoded in the keyslot header and so > potentially configurable, in pratice the cryptsetup impl mandates > this has the fixed value 4000. To avoid incompatibility apply the > same enforcement in QEMU too. This also caps the memory usage for > key material when QEMU tries to open a LUKS volume. > > Signed-off-by: Daniel P. Berrangé > --- > crypto/block-luks.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/crypto/block-luks.c b/crypto/block-luks.c > index 27d1b34c1d..81744e2a8e 100644 > --- a/crypto/block-luks.c > +++ b/crypto/block-luks.c > @@ -582,8 +582,9 @@ qcrypto_block_luks_check_header(const QCryptoBlockLUKS *luks, Error **errp) > header_sectors, > slot1->stripes); > > - if (slot1->stripes == 0) { > - error_setg(errp, "Keyslot %zu is corrupted (stripes == 0)", i); > + if (slot1->stripes != QCRYPTO_BLOCK_LUKS_STRIPES) { > + error_setg(errp, "Keyslot %zu is corrupted (stripes %d != %d)", > + i, slot1->stripes, QCRYPTO_BLOCK_LUKS_STRIPES); > return -1; > } In nbdkit I decided to just check that this number < 10000, but I agree that the only important implementation (the kernel) always fixes this at 4000 (cryptsetup.git/lib/keymanage.c), so: Reviewed-by: Richard W.M. Jones Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html