On Mon, Aug 26, 2019 at 9:30 AM Jarkko Sakkinen
<jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote:
>
> On Mon, Aug 26, 2019 at 11:30:28AM -0400, Peter Jones wrote:
> > When there are no entries to put into the final event log, some machines
> > will return the template they would have populated anyway. In this case
> > the nr_events field is 0, but the rest of the log is just garbage.
> >
> > This patch stops us from trying to iterate the table with
> > __calc_tpm2_event_size() when the number of events in the table is 0.
> >
> > Signed-off-by: Peter Jones <pjones@xxxxxxxxxx>
> > Tested-by: Lyude Paul <lyude@xxxxxxxxxx>
> > ---
> > drivers/firmware/efi/tpm.c | 14 +++++++++-----
> > 1 file changed, 9 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c
> > index 1d3f5ca3eaa..be51ed17c6e 100644
> > --- a/drivers/firmware/efi/tpm.c
> > +++ b/drivers/firmware/efi/tpm.c
> > @@ -75,11 +75,15 @@ int __init efi_tpm_eventlog_init(void)
> > goto out;
> > }
> >
> > - tbl_size = tpm2_calc_event_log_size((void *)efi.tpm_final_log
> > - + sizeof(final_tbl->version)
> > - + sizeof(final_tbl->nr_events),
> > - final_tbl->nr_events,
> > - log_tbl->log);
> > + tbl_size = 0;
> > + if (final_tbl->nr_events != 0) {
> > + void *events = (void *)efi.tpm_final_log
> > + + sizeof(final_tbl->version)
> > + + sizeof(final_tbl->nr_events);
> > + tbl_size = tpm2_calc_event_log_size(events,
> > + final_tbl->nr_events,
> > + log_tbl->log);
> > + }
>
> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Acked-by: Matthew Garrett <mjg59@xxxxxxxxxx>
