From: Tejun Heo <tj@kernel.org>
To: Pavel Emelyanov <xemul@parallels.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Cyrill Gorcunov <gorcunov@openvz.org>,
Glauber Costa <glommer@parallels.com>,
Andi Kleen <andi@firstfloor.org>,
Andrew Morton <akpm@linux-foundation.org>,
Matt Helsley <matthltc@us.ibm.com>
Subject: Re: [PATCH 1/4] Routine for generating an safe ID for kernel pointer
Date: Tue, 15 Nov 2011 07:20:23 -0800 [thread overview]
Message-ID: <20111115152023.GA18919@google.com> (raw)
In-Reply-To: <4EC24EC1.7060203@parallels.com>
On Tue, Nov 15, 2011 at 03:36:33PM +0400, Pavel Emelyanov wrote:
> +unsigned long gen_object_id(void *ptr)
> +{
> + if (!ptr)
> + return 0;
> +
> + if (unlikely(!ptr_poison)) {
> + spin_lock(&ptr_poison_lock);
> + if (!ptr_poison)
> + get_random_bytes(&ptr_poison, sizeof(ptr_poison));
> + spin_unlock(&ptr_poison_lock);
> + }
One thing that worries me about this is that there's one ptr_poison
for all id's and any single leak of a pointer value will make all ids
vulnerable. If we're going to do this, let's segregate different id
spaces and use different poison values for each.
Thank you.
--
tejun
next prev parent reply other threads:[~2011-11-15 15:20 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-15 11:35 [PATCH 0/4] Checkpoint/Restore: Show in proc IDs of objects that can be shared between tasks Pavel Emelyanov
2011-11-15 11:36 ` [PATCH 1/4] Routine for generating an safe ID for kernel pointer Pavel Emelyanov
2011-11-15 11:38 ` Pekka Enberg
2011-11-15 11:44 ` Pavel Emelyanov
2011-11-15 11:51 ` Pekka Enberg
2011-11-15 15:13 ` Eric Dumazet
2011-11-15 15:20 ` Tejun Heo [this message]
2011-11-15 11:36 ` [PATCH 2/4] proc: Show namespaces IDs in /proc/pid/ns/* files Pavel Emelyanov
2011-11-15 11:37 ` [PATCH 3/4] proc: Show open file ID in /proc/pid/fdinfo/* Pavel Emelyanov
2011-11-16 5:44 ` [PATCH 0/4] Checkpoint/Restore: Show in proc IDs of objects that can be shared between tasks Matt Helsley
2011-11-16 6:19 ` Cyrill Gorcunov
2011-11-16 8:25 ` Pavel Emelyanov
2011-11-18 23:25 ` Matt Helsley
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