On Fri Aug 16, 2024 at 2:55 PM EEST, Jonathan McDowell wrote:
> From: Jonathan McDowell <noodles@xxxxxxxx>
>
> tpm_dev_transmit prepares the TPM space before attempting command
> transmission. However if the command fails no rollback of this
> preparation is done. This can result in transient handles being leaked
> if the device is subsequently closed with no further commands performed.
>
> Fix this by flushing the space in the event of command transmission
> failure.
>
> Fixes: 745b361e989a ("tpm: infrastructure for TPM spaces")
> Signed-off-by: Jonathan McDowell <noodles@xxxxxxxx>
> ---
> v2:
> - Add 'Fixes:'
> - Cc James as one of the original authors
> - Add space sanity check in tpm2_flush_space
>
> drivers/char/tpm/tpm-dev-common.c | 2 ++
> drivers/char/tpm/tpm2-space.c | 3 +++
> 2 files changed, 5 insertions(+)
>
> diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c
> index 30b4c288c1bb..c3fbbf4d3db7 100644
> --- a/drivers/char/tpm/tpm-dev-common.c
> +++ b/drivers/char/tpm/tpm-dev-common.c
> @@ -47,6 +47,8 @@ static ssize_t tpm_dev_transmit(struct tpm_chip *chip, struct tpm_space *space,
>
> if (!ret)
> ret = tpm2_commit_space(chip, space, buf, &len);
> + else
> + tpm2_flush_space(chip);
>
> out_rc:
> return ret ? ret : len;
> diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
> index 4892d491da8d..25a66870c165 100644
> --- a/drivers/char/tpm/tpm2-space.c
> +++ b/drivers/char/tpm/tpm2-space.c
> @@ -169,6 +169,9 @@ void tpm2_flush_space(struct tpm_chip *chip)
> struct tpm_space *space = &chip->work_space;
> int i;
>
> + if (!space)
> + return;
> +
> for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++)
> if (space->context_tbl[i] && ~space->context_tbl[i])
> tpm2_flush_context(chip, space->context_tbl[i]);
I'll pick this for 6.12: I think it is a legit fix but not worth of
disturbing the in-progress release cycle (which is going almost rc4
already):
Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Thank you.
BR, Jarkko
