Hello Loïc,
On Tue, May 12, 2020 at 6:02 AM Loïc Yhuel <loic.yhuel@xxxxxxxxx> wrote:
>
> This fixes the boot issues since 5.3 on several Dell models when the TPM
> is enabled. Depending on the exact grub binary, booting the kernel would
> freeze early, or just report an error parsing the final events log.
>
> We get an event log in the SHA-1 format, which doesn't have a
> tcg_efi_specid_event_head in the first event, and there is a final events
> table which doesn't match the crypto agile format.
> __calc_tpm2_event_size reads bad "count" and "efispecid->num_algs", and
> either fails, or loops long enough for the machine to be appear frozen.
>
> So we now only parse the final events table, which is per the spec always
> supposed to be in the crypto agile format, when we got a event log in this
> format.
>
> Fixes: c46f3405692de ("tpm: Reserve the TPM final events table")
> Fixes: 166a2809d65b2 ("tpm: Don't duplicate events from the final event log in the TCG2 log")
> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1779611
> Signed-off-by: Loïc Yhuel <loic.yhuel@xxxxxxxxx>
> ---
As you mention, that's what the TCG EFI Protocol Specification says
about the EFI Final Events Table so I agree with your patch.
Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
Best regards,
Javier
