linux-kernel - Re: [PATCH 2/3] tpm: ensure tpm is in known state at startup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <CZ9BYSWZVHLI.27ICPVJMGNHIM@seitikki>
Date: Mon, 19 Feb 2024 20:17:42 +0000
From: "Jarkko Sakkinen" <jarkko@...nel.org>
To: "Daniel P. Smith" <dpsmith@...rtussolutions.com>, "Jason Gunthorpe"
 <jgg@...pe.ca>, <linux-integrity@...r.kernel.org>,
 <linux-kernel@...r.kernel.org>
Cc: "Ross Philipson" <ross.philipson@...cle.com>, "Peter Huewe"
 <peterhuewe@....de>
Subject: Re: [PATCH 2/3] tpm: ensure tpm is in known state at startup

On Mon Feb 19, 2024 at 7:17 PM UTC, Daniel P. Smith wrote:
> On 2/1/24 17:33, Jarkko Sakkinen wrote:
> > On Wed Jan 31, 2024 at 7:08 PM EET, Daniel P. Smith wrote:
> >> When tis core initializes, it assumes all localities are closed. There
> >         ~~~~~~~~
> >         tpm_tis_core
> > 
> >> are cases when this may not be the case. This commit addresses this by
> >> ensuring all localities are closed before initializing begins.
> > 
> > Remove the last sentence and replace with this paragraph:
> > 
> > "Address this by ensuring all the localities are closed in the beginning
> > of tpm_tis_core_init(). There are environments, like Intel TXT, which
> > may leave a locality open. Close all localities to start from a known
> > state."
>
> okay.
>
> > BTW, why we should motivated to take this patch anyway?
>
> Without this change, in this scenario the driver is unnecessarily 
> thrashing the TPM with locality requests/relinquishes pairs for which 
> will never take effect and that the TPM must do state change tracking. 
> While I am confident that TPM chips are resilient to such abuse, I do 
> not think it would be good form to knowingly allow such behavior to occur.

This would a factor better motivation part for the commit. I can 
buy this argument instead the one right now, thanks :-)

BR, Jarkko