Re: [PATCH 2/3] tpm: Get rid of chip->pdev

[Jason Gunthorpe]

On Fri, Feb 12, 2016 at 08:31:21PM -0500, Stefan Berger wrote:
> > I'll send you something else that might work for vtpm...'
> 
> The vtpm driver will introduce chip->priv, which will point to vtpm_dev. For
> this reason we need to hold a reference to the vtpm_dev->dev in the
> front end.

This should take care of it for all drivers including vtpm.

https://github.com/jgunthorpe/linux/commits/for-jarkko

At the very least this turns silent use after free into a null pointer
oops.

We should also discuss if we want to continue to have the driver
module locked while /dev/tpmX is open, that is no longer needed for
corectness.