From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758172Ab0JLTEn (ORCPT ); Tue, 12 Oct 2010 15:04:43 -0400 Received: from out1.smtp.messagingengine.com ([66.111.4.25]:42667 "EHLO out1.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751979Ab0JLTEm (ORCPT ); Tue, 12 Oct 2010 15:04:42 -0400 X-Sasl-enc: d9Xz50lzVNdHqUPAEaf/8NXBAUVsiIWQhuCbVGi8CpRF 1286910281 Date: Tue, 12 Oct 2010 16:04:38 -0300 From: Henrique de Moraes Holschuh To: Greg KH Cc: linux-kernel@vger.kernel.org, stable@kernel.org, Alasdair G Kergon , Milan Broz Subject: Re: [stable] dm-crypt: plain64 IV support for -stable? Message-ID: <20101012190438.GB16717@khazad-dum.debian.net> References: <20101012132511.GA24455@khazad-dum.debian.net> <20101012141143.GA12143@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101012141143.GA12143@kroah.com> X-GPG-Fingerprint: 1024D/1CDB0FE3 5422 5C61 F6B7 06FB 7E04 3738 EE25 DE3F 1CDB 0FE3 User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 12 Oct 2010, Greg KH wrote: > Which -stable tree? .27, .32, .35, or any/all of them? Please be more > specific when asking for this in the future. Just 2.6.32. It is already in 2.6.35, and 2.6.27 is too old for it to matter. > > Without it, users of LTS kernels like 2.6.32 are missing important > > functionality (as in: might not be able to mount some LUKS volumes > > created on newer kernels). > > Also note that this patch really looks like a "new feature", not a > bugfix or anything that matches up with what > Documentation/stable_kernel_rules.txt defines. So I don't think that it > really is something to add to a stable kernel. Using "plain" for IVs on block devices with more than 2^32 blocks will cause the same IV to be used twice due to roll-over. This is not a good thing, although it might be not bad enough to matter much (or it could be a terrible problem. Someone who groks crypto for real would have to answer that). One cannot fix "plain", or data after the roll-over point becomes unreadable on any already-existing devices. Thus, a new IV was added with the fix, "plain64". Distros will probably need to backport this, as userspace and docs are already starting to tell users to use aes-xts-plain64 and not aes-xts-plain. They will use them in their portable HDs, and then will not be able to read them back in various stable distros. Might as well do it upstream where it will benefit everybody... -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh