Re: [PATCH v2 1/2] efi+tpm: Don't access event->count when it isn't mapped.

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

On Wed, Sep 25, 2019 at 12:25:05PM +0200, Ard Biesheuvel wrote:
> On Wed, 25 Sep 2019 at 12:16, Jarkko Sakkinen
> <jarkko.sakkinen@linux.intel.com> wrote:
> >
> > From: Peter Jones <pjones@redhat.com>
> >
> > Some machines generate a lot of event log entries.  When we're
> > iterating over them, the code removes the old mapping and adds a
> > new one, so once we cross the page boundary we're unmapping the page
> > with the count on it.  Hilarity ensues.
> >
> > This patch keeps the info from the header in local variables so we don't
> > need to access that page again or keep track of if it's mapped.
> >
> > Fixes: 44038bc514a2 ("tpm: Abstract crypto agile event size calculations")
> > Cc: linux-efi@vger.kernel.org
> > Cc: linux-integrity@vger.kernel.org
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Peter Jones <pjones@redhat.com>
> > Tested-by: Lyude Paul <lyude@redhat.com>
> > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > Acked-by: Matthew Garrett <mjg59@google.com>
> > Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> 
> Thanks Jarkko.
> 
> Shall I take these through the EFI tree?

Would be great, if you could because I already sent one PR with fixes for
v5.4-rc1 yesterday.

/Jarkko