From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Subject: Re: [tpmdd-devel] [PATCH] tpm: remove chip_num parameter from
 in-kernel API
Date: Tue, 24 Oct 2017 09:55:26 -0600
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Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
        Stefan Berger <stefanb@linux.vnet.ibm.com>,
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        David Howells <dhowells@redhat.com>,
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        James Morris <james.l.morris@oracle.com>,
        Matt Mackall <mpm@selenic.com>,
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To: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
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On Tue, Oct 24, 2017 at 09:21:15PM +0530, PrasannaKumar Muralidharan wrote:

> Please check the RFC [1]. It does use chip id. The rfc has issues and
> has to be fixed but still there could be users of the API.
> 
> 1. https://www.spinics.net/lists/linux-crypto/msg28282.html

That patch isn't safe at all. You need to store a kref to th chip in
the hwrng, not parse a string.

Jason