Re: [RFC PATCH] tpm: don't return -EINVAL if TPM command validation fails

Jarkko Sakkinen
2017-11-26T14:06:52Z

On Tue, Nov 21, 2017 at 08:29:07PM +0000, Roberts, William C wrote:
> > TPM specification is not a formal specification AFAIK.
>
> The published parts are, granted many things are changing.

Yes, how it defines the protocol, you are correct. It does not have a
formal definition of RM behavior or at least I haven't found it.

> > > Yes, sorry for that. It wasn't clear to me that there was a sandbox
> > > and my lack of familiarity with the code was the reason why I posted
> > > as a RFC in the first place.
> > >
> > > Do you agree with Jason's suggestion to send a synthesized TPM command
> > > in the that the command isn't supported?
> >
> > Nope.
>
> We should update the elf loader to make sure that ELF files don't contain
> Incorrect instructions. We shouldn't have this type of policy in the driver
> considering that the tpm is designed to handle it. Obviously you disagree,
> just understand you're wrong :-P

I think -EINVAL is better than synthetizing commands that are not really
from the TPM. And we would break backwards compatability by doing this.

As I said in an earlier response I would rather compare resource
manager to virtual memory than virtual machine.

/Jarkko