Re: [PATCH][next] efi/tpm: fix sanity check of unsigned tbl_size being less than zero

[Jerry Snitselaar]

On Tue Oct 08 19, Dan Carpenter wrote:
> On Tue, Oct 08, 2019 at 11:01:53AM +0100, Colin King wrote:
> > From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> >
> > Currently the check for tbl_size being less than zero is always false
> > because tbl_size is unsigned. Fix this by making it a signed int.
> >
> > Addresses-Coverity: ("Unsigned compared against 0")
> > Fixes: e658c82be556 ("efi/tpm: Only set 'efi_tpm_final_log_size' after successful event log parsing")
> > Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> > ---
> >  drivers/firmware/efi/tpm.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c
> > index 703469c1ab8e..ebd7977653a8 100644
> > --- a/drivers/firmware/efi/tpm.c
> > +++ b/drivers/firmware/efi/tpm.c
> > @@ -40,7 +40,7 @@ int __init efi_tpm_eventlog_init(void)
> >  {
> >  	struct linux_efi_tpm_eventlog *log_tbl;
> >  	struct efi_tcg2_final_events_table *final_tbl;
> > -	unsigned int tbl_size;
> > +	int tbl_size;
> >  	int ret = 0;
>
>
> Do we need to do a "ret = tbl_size;"?  Currently we return success.
> It's a pitty that tpm2_calc_event_log_size() returns a -1 instead of
> -EINVAL.
>
> regards,
> dan carpenter

perhaps "ret = -EINVAL;"? Currently nothing checks the return value of efi_tpm_eventlog_init though.