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From: David Lang <david.lang@digitalinsight.com>
To: Roman Zippel <zippel@linux-m68k.org>
Cc: David Howells <dhowells@redhat.com>,
	torvalds@osdl.org, akpm@osdl.org, herbert.xu@redhat.com,
	linux-kernel@vger.kernel.org, davej@redhat.com,
	arjan@infradead.org, linux-crypto@vger.kernel.org
Subject: Re: [PATCH 0/6] MODSIGN: Kernel module signing
Date: Thu, 15 Feb 2007 12:01:22 -0800 (PST)	[thread overview]
Message-ID: <Pine.LNX.4.63.0702151155330.9862@qynat.qvtvafvgr.pbz> (raw)
In-Reply-To: <Pine.LNX.4.64.0702151901380.14458@scrub.home>

On Thu, 15 Feb 2007, Roman Zippel wrote:

> On Thu, 15 Feb 2007, David Howells wrote:
>
>> It is possible to protect /dev/mem and /dev/kmem or make them unavailable and
>> it is possible to protect the kernel's memory whilst it is running (provided
>> you don't have nommu or broken hardware and you don't let userspace concoct any
>> DMA request it likes) which mostly closes those other vectors I mentioned.
>> This isn't something I intended to look at with this patch.  Those are separate
>> holes.
>
> Exactly and as long as there are these holes, these patches are only
> kernel bloat. The simple verification can also be done in userspace and
> module signing offers no real security.
> What real value do these patches provide, that can't be reached via other
> means? Who else than distributions would be interested in this? Pretty
> much any use you initially mentioned can be done in simpler ways, e.g.
> anyone afraid of modules simply disables module loading completely.

this issue, and these holes keep comeing up in discussions, why can't these 
holes be closed? I seem to remember seeing patches that would remove /dev/kmem 
being sent to the list, but they weren't accepted into the kernel (and I seem to 
remember people being against the concept of removeing them, not against 
techincal details of the patches. but this was many years ago)

at one point I remember hearing that X required raw /dev/kmem, but for servers 
you don't need/want X anyway, so this is a useful option even if X doesn't get 
fixed.

David Lang

  reply	other threads:[~2007-02-15 20:17 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-14 19:09 David Howells
2007-02-14 19:09 ` [PATCH 2/6] MODSIGN: In-kernel crypto extensions David Howells
2007-02-14 19:09 ` [PATCH 3/6] MODSIGN: Add indications of module ELF types David Howells
2007-02-14 19:09 ` [PATCH 4/6] MODSIGN: Module ELF verifier David Howells
2007-02-14 19:10 ` [PATCH 5/6] MODSIGN: Module signature checker and key manager David Howells
2007-02-14 19:10 ` [PATCH 6/6] MODSIGN: Apply signature checking to modules on module load David Howells
2007-02-14 19:26 ` [PATCH 0/6] MODSIGN: Kernel module signing Linus Torvalds
2007-02-14 19:40 ` David Howells
2007-02-14 21:32   ` Michael Halcrow
2007-02-14 21:59   ` David Howells
2007-02-14 22:21     ` Michael Halcrow
2007-02-15 21:31   ` Indan Zupancic
2007-02-15  3:41 ` Andrew Morton
2007-02-15  4:13   ` Dave Jones
2007-02-15  5:35     ` Andreas Gruenbacher
2007-02-15  5:45       ` Dave Jones
2007-02-15  6:14         ` Andreas Gruenbacher
2007-02-15  6:22           ` Dave Jones
2007-02-15 20:34           ` Valdis.Kletnieks
2007-02-15 22:12             ` Andreas Gruenbacher
2007-02-16  0:15               ` Olaf Kirch
2007-02-15 22:10           ` Pavel Machek
2007-02-15 20:55     ` Valdis.Kletnieks
2007-02-15 21:32       ` Adrian Bunk
2007-02-15 22:12         ` Valdis.Kletnieks
2007-02-15 14:35 ` Roman Zippel
2007-02-15 17:32 ` David Howells
2007-02-15 18:33   ` Roman Zippel
2007-02-15 20:01     ` David Lang [this message]
2007-02-15 21:01       ` Roman Zippel
2007-02-15 21:03 ` Adrian Bunk
2007-02-15 22:13 ` Pavel Machek
2007-02-16 20:21   ` Dave Jones
2007-02-16 20:27     ` Arjan van de Ven
     [not found] <7OPWh-470-9@gated-at.bofh.it>
     [not found] ` <7OxPF-16i-7@gated-at.bofh.it>
     [not found]   ` <7OSKA-8A-17@gated-at.bofh.it>
     [not found]     ` <7OTGJ-1G5-23@gated-at.bofh.it>
2007-02-16 15:38       ` Bodo Eggert

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