Re: [PATCH] tpm: fixes uninitialized allocated banks for IBM vtpm driver

Jarkko Sakkinen
2019-07-05T10:42:26Z

On Wed, 2019-07-03 at 23:32 -0400, Nayna Jain wrote:
> The nr_allocated_banks and allocated banks are initialized as part of
> tpm_chip_register. Currently, this is done as part of auto startup
> function. However, some drivers, like the ibm vtpm driver, do not run
> auto startup during initialization. This results in uninitialized memory
> issue and causes a kernel panic during boot.
>
> This patch moves the pcr allocation outside the auto startup function
> into tpm_chip_register. This ensures that allocated banks are initialized
> in any case.
>
> Fixes: 879b589210a9 ("tpm: retrieve digest size of unknown algorithms with
> PCR read")
> Signed-off-by: Nayna Jain <nayna@linux.ibm.com>

Please add

Reported-by: Michal Suchanek <msuchanek@suse.de>

It is missing. Michal is there a chance you could try this out once
Nayna send a new version?

> ---
> drivers/char/tpm/tpm-chip.c | 37 +++++++++++++++++++++++++++++++++++++
> drivers/char/tpm/tpm.h | 1 +
> drivers/char/tpm/tpm1-cmd.c | 12 ------------
> drivers/char/tpm/tpm2-cmd.c | 6 +-----
> 4 files changed, 39 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index 8804c9e916fd..958508bb8379 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -550,6 +550,39 @@ static int tpm_add_hwrng(struct tpm_chip *chip)
> return hwrng_register(&chip->hwrng);
> }
>
> +/*
> + * tpm_pcr_allocation() - initializes the chip allocated banks for PCRs
> + */
> +static int tpm_pcr_allocation(struct tpm_chip *chip)

Why that name and not tpm_get_pcr_allocation()? Do not get why
"get_" has been dropped. Please add it back.

Would be senseful to create tpm1_get_pcr_allocation() to tpm1-cmd.c
now that a new function needs to be introduced anyway. Please do
it for that for TPM 1.x part.

/Jarkko