From: Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
To: Jarkko Sakkinen
<jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Cc: linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: Re: [PATCH] tpm: check size of response before accessing data
Date: Mon, 9 Jan 2017 09:15:25 -0700 [thread overview]
Message-ID: <20170109161525.GA13903@obsidianresearch.com> (raw)
In-Reply-To: <20170109160538.gwvksj253wl2v5oy-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
On Mon, Jan 09, 2017 at 06:05:38PM +0200, Jarkko Sakkinen wrote:
> On Thu, Jan 05, 2017 at 07:11:24AM -0500, Stefan Berger wrote:
> > Check the size of the response before accesing data in
> > the response packet. This is to avoid accessing data beyond
> > the end of the response.
> >
> > Signed-off-by: Stefan Berger <stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
>
> How on earth this could happen if we request only one property?
His (software) TPM is broken.
Now that we have the vtpm stuff it is super-critical that the kernel
unmarshal path be bomb proof - it needs to treat the TPM itself as a
hostile entity.
You should look at all of it and make sure the proper bounds checks
are done, multiples can't overflow, and so forth.
Jason
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next prev parent reply other threads:[~2017-01-09 16:15 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-05 12:11 [PATCH] tpm: check size of response before accessing data Stefan Berger
[not found] ` <1483618284-3470-1-git-send-email-stefanb-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2017-01-05 12:14 ` [PATCH] tpm: check size of response before accessingdata Stefan Berger
2017-01-09 16:05 ` [PATCH] tpm: check size of response before accessing data Jarkko Sakkinen
[not found] ` <20170109160538.gwvksj253wl2v5oy-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-01-09 16:15 ` Jason Gunthorpe [this message]
2017-01-09 18:09 ` Stefan Berger
2017-01-09 22:59 ` Jarkko Sakkinen
2017-01-10 0:15 ` Stefan Berger
2017-01-10 8:55 ` Jarkko Sakkinen
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