Re: [PATCH v2 1/1] tpm: reject duplicate PCR banks in tpm2_get_pcr_allocation

[Jarkko Sakkinen <jarkko@kernel.org>]

On Wed, Oct 21, 2026 at 04:49:34PM +0800, Yuqi Xu wrote:
> Hi Jarkko,
> 
> On Tue, Oct 20, 2026 at 06:30:11PM +0300, Jarkko Sakkinen wrote:
> > OK, so now that I was writing summary of TPM pull request changes, I
> > came into conclusion that this is not a bug fix, unless you can show
> > from TCG specifications that this is possible spec allowed behaviour.
> 
> I cannot. Part 1 identifies a PCR bank by its hash algorithm, so one
> hash is one bank. In the TCG reference implementation, TPM2_PCR_Allocate
> keeps only the last selection when the same hash appears more than once,
> and TPM2_GetCapability(TPM_CAP_PCRS) returns that allocation. A
> conformant TPM will not report a duplicate.
> 
> > So I can keep the commit but would remove fixes and bug related tags
> > from this. It is essentially hardening and safety measure but not a
> > bug fix.
> 
> Please do. Drop Fixes:, Cc: stable, Reported-by:, and Closes:. The code
> change can stay as hardening.
> 
> > Do you have something to say that I might have missed?
> 
> Only that the commit is not on the current master after the rebase. I
> can send a v3 without those tags if that is easier than reapplying it
> yourself.

Thanks for quick reaction. I can still get it to the pull request.

This was just a question of taxonomy. I think it is otherwise
useful to have this validation in place (i.e. not disregarding
the change overall).

> 
> Thanks,
> Yuqi
> 

Br, Jarkko