Re: [PATCH] tpm: do handle area size validation only when TPM space used

From: Jarkko Sakkinen
Date: Tue Mar 28 2017 - 06:25:26 EST


So do you need this or not?

/Jarkko

On Mon, Mar 27, 2017 at 12:08:15AM +0300, Jarkko Sakkinen wrote:
> In order to not cause backwards compatibility issues with
> /dev/tpm0 disable handle area size validation if tpm_transmit
> is not called with a TPM space.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxx>
> ---
> drivers/char/tpm/tpm-interface.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index bf0c3fa..158c1db 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -328,7 +328,9 @@ unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
> }
> EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
>
> -static bool tpm_validate_command(struct tpm_chip *chip, const u8 *cmd,
> +static bool tpm_validate_command(struct tpm_chip *chip,
> + struct tpm_space *space,
> + const u8 *cmd,
> size_t len)
> {
> const struct tpm_input_header *header = (const void *)cmd;
> @@ -340,6 +342,9 @@ static bool tpm_validate_command(struct tpm_chip *chip, const u8 *cmd,
> if (len < TPM_HEADER_SIZE)
> return false;
>
> + if (!space)
> + return true;
> +
> if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
> cc = be32_to_cpu(header->ordinal);
>
> @@ -386,7 +391,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
> unsigned long stop;
> bool need_locality;
>
> - if (!tpm_validate_command(chip, buf, bufsiz))
> + if (!tpm_validate_command(chip, space, buf, bufsiz))
> return -EINVAL;
>
> if (bufsiz > TPM_BUFSIZE)
> --
> 2.9.3
>