public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Tejun Heo <tj@kernel.org>
To: Kyle Moffett <kyle@moffetthome.net>
Cc: Pekka Enberg <penberg@kernel.org>,
	Cyrill Gorcunov <gorcunov@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Pavel Emelyanov <xemul@parallels.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Glauber Costa <glommer@parallels.com>,
	Andi Kleen <andi@firstfloor.org>,
	Matt Helsley <matthltc@us.ibm.com>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	Vasiliy Kulikov <segoon@openwall.com>
Subject: Re: [PATCH v2 0/4] Checkpoint/Restore: Show in proc IDs of objects that can be shared between tasks
Date: Fri, 18 Nov 2011 15:46:35 -0800	[thread overview]
Message-ID: <20111118234635.GB29378@google.com> (raw)
In-Reply-To: <CAGZ=bqJBWboHrh_zc4mWNK5DuY3vy1+QhrMosXK4nusfqDbRSQ@mail.gmail.com>

Hello,

On Fri, Nov 18, 2011 at 05:10:37PM -0500, Kyle Moffett wrote:
> The #1 rule of one-time pads is never use it for more than one thing,
> and you use it here for every object in the system.

The new version is using different poison for different types of
objects.

> If you actually want to be able to compare uniqueness without exposing
> anything vulnerable to various kinds of guessing, you should generate
> a random 64-bit value for each class of object and then use a proper
> cryptographic hash function on it:
>   crypto_hash(concat(object_ptr, random_value))
> 
> Even given the best possible practical attacks against SHA1 or MD5
> today both still provides more than enough security to prevent someone
> from guessing "object_ptr" in less than an absurd amount of time.

So, per-type poison + crypto hash, it is then.

Thank you very much.

-- 
tejun

  reply	other threads:[~2011-11-18 23:46 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-17  9:55 [PATCH v2 0/4] Checkpoint/Restore: Show in proc IDs of objects that can be shared between tasks Pavel Emelyanov
2011-11-17  9:56 ` [PATCH 1/4] Routine for generating a safe ID for kernel pointer Pavel Emelyanov
2011-11-17  9:56 ` [PATCH 2/4] proc: Show namespaces IDs in /proc/pid/ns/* files Pavel Emelyanov
2011-11-17  9:56 ` [PATCH 3/4] proc: Show open file ID in /proc/pid/fdinfo/* Pavel Emelyanov
2011-11-17 20:48 ` [PATCH v2 0/4] Checkpoint/Restore: Show in proc IDs of objects that can be shared between tasks Andrew Morton
2011-11-18  9:24   ` Pavel Emelyanov
2011-11-18 19:07     ` Andrew Morton
2011-11-18 20:03       ` Cyrill Gorcunov
2011-11-18 20:37         ` Andrew Morton
2011-11-18 21:03           ` Cyrill Gorcunov
2011-11-18 21:09             ` Pekka Enberg
2011-11-18 22:10               ` Kyle Moffett
2011-11-18 23:46                 ` Tejun Heo [this message]
2011-11-19  1:09                   ` Kyle Moffett
2011-11-19  5:30                     ` Cyrill Gorcunov
2011-11-18 23:38             ` Matt Helsley
2011-11-19  5:35               ` Cyrill Gorcunov
2011-11-19  7:57       ` Vasiliy Kulikov
2011-11-19  8:10         ` Vasiliy Kulikov
2011-11-19  8:18           ` Vasiliy Kulikov
2011-11-19 15:34           ` Cyrill Gorcunov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20111118234635.GB29378@google.com \
    --to=tj@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=andi@firstfloor.org \
    --cc=eric.dumazet@gmail.com \
    --cc=glommer@parallels.com \
    --cc=gorcunov@gmail.com \
    --cc=kyle@moffetthome.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=matthltc@us.ibm.com \
    --cc=penberg@kernel.org \
    --cc=segoon@openwall.com \
    --cc=xemul@parallels.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox