From: Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
To: Jarkko Sakkinen
<jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Cc: "moderated list:TPM DEVICE DRIVER"
<tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>,
open list <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH] tpm: fix buffer overflow in /dev/tpm0
Date: Sun, 11 Sep 2016 22:05:46 -0600 [thread overview]
Message-ID: <20160912040546.GA14625@obsidianresearch.com> (raw)
In-Reply-To: <1473596340-11376-1-git-send-email-jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
On Sun, Sep 11, 2016 at 03:19:00PM +0300, Jarkko Sakkinen wrote:
> tpm_write() does not check whether the buffer has at least enough space
> for the header before passing it to tpm_transmit() so an overflow can
> happen.
Eh?
tpm_write uses a hard wired buffer size of TPM_BUFSIZE when working
with tpm_transmit.
in_size is never used except for the copy. We should probably fix that
to sanity check the header length vs in_size.
That doesn't seem to be a security issue however because the header
length is propery limited to TPM_BUFSIZE and the data buffer is
allocated specifically for that process using kzalloc.
Jason
------------------------------------------------------------------------------
WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Peter Huewe <peterhuewe@gmx.de>,
Marcel Selhorst <tpmdd@selhorst.net>,
"moderated list:TPM DEVICE DRIVER"
<tpmdd-devel@lists.sourceforge.net>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] tpm: fix buffer overflow in /dev/tpm0
Date: Sun, 11 Sep 2016 22:05:46 -0600 [thread overview]
Message-ID: <20160912040546.GA14625@obsidianresearch.com> (raw)
In-Reply-To: <1473596340-11376-1-git-send-email-jarkko.sakkinen@linux.intel.com>
On Sun, Sep 11, 2016 at 03:19:00PM +0300, Jarkko Sakkinen wrote:
> tpm_write() does not check whether the buffer has at least enough space
> for the header before passing it to tpm_transmit() so an overflow can
> happen.
Eh?
tpm_write uses a hard wired buffer size of TPM_BUFSIZE when working
with tpm_transmit.
in_size is never used except for the copy. We should probably fix that
to sanity check the header length vs in_size.
That doesn't seem to be a security issue however because the header
length is propery limited to TPM_BUFSIZE and the data buffer is
allocated specifically for that process using kzalloc.
Jason
next prev parent reply other threads:[~2016-09-12 4:05 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-11 12:19 [PATCH] tpm: fix buffer overflow in /dev/tpm0 Jarkko Sakkinen
2016-09-11 12:19 ` Jarkko Sakkinen
2016-09-11 12:51 ` Jarkko Sakkinen
[not found] ` <20160911125142.GA20191-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2016-09-11 18:57 ` Jarkko Sakkinen
2016-09-11 18:57 ` Jarkko Sakkinen
[not found] ` <1473596340-11376-1-git-send-email-jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2016-09-12 4:05 ` Jason Gunthorpe [this message]
2016-09-12 4:05 ` Jason Gunthorpe
[not found] ` <20160912040546.GA14625-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2016-09-12 7:50 ` Jarkko Sakkinen
2016-09-12 7:50 ` Jarkko Sakkinen
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