Messages in this thread | | | Date | Mon, 30 Sep 2019 08:57:12 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH 4.19 33/63] tpm: Fix TPM 1.2 Shutdown sequence to prevent future TPM operations |
| |
On Mon, Sep 30, 2019 at 08:13:46AM +0200, Pavel Machek wrote: >> From: Vadim Sukhomlinov <sukhomlinov@google.com> >> >> commit db4d8cb9c9f2af71c4d087817160d866ed572cc9 upstream >> >> TPM 2.0 Shutdown involve sending TPM2_Shutdown to TPM chip and disabling >> future TPM operations. TPM 1.2 behavior was different, future TPM >> operations weren't disabled, causing rare issues. This patch ensures >> that future TPM operations are disabled. > >> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c >> index 46caadca916a0..dccc61af9ffab 100644 >> --- a/drivers/char/tpm/tpm-chip.c >> +++ b/drivers/char/tpm/tpm-chip.c >> @@ -187,12 +187,15 @@ static int tpm_class_shutdown(struct device *dev) >> { >> struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev); >> >> + down_write(&chip->ops_sem); >> if (chip->flags & TPM_CHIP_FLAG_TPM2) { >> down_write(&chip->ops_sem); >> tpm2_shutdown(chip, TPM2_SU_CLEAR); >> chip->ops = NULL; >> up_write(&chip->ops_sem); >> } >> + chip->ops = NULL; >> + up_write(&chip->ops_sem); > >This is wrong, it takes &chip->ops_sem twice, that can't be >good. db4d8cb9c9f2af71c4d087817160d866ed572cc9 does not have that >problem.
I agree. I've dropped it from 4.19 and 4.14.
Jarkko, can you take a look at this again please?
-- Thanks, Sasha
| |