[PATCH v4 3/3] tpm: Fix TPM 1.2 Shutdown sequence to prevent future TPM operations

[PATCH v4 3/3] tpm: Fix TPM 1.2 Shutdown sequence to prevent future TPM operations

[Jarkko Sakkinen]

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.

Fixes: d1bd4a792d39 ("tpm: Issue a TPM2_Shutdown for TPM2 devices.")
Cc: stable@vger.kernel.org
Signed-off-by: Vadim Sukhomlinov <sukhomlinov@google.com>
[dianders: resolved merge conflicts with mainline]
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/char/tpm/tpm-chip.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 0eca20c5a80c..ac8a3812fbcd 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -158,12 +158,11 @@ static int tpm_class_shutdown(struct device *dev)
 {
 	struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
 
-	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
-		down_write(&chip->ops_sem);
+	down_write(&chip->ops_sem);
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
 		tpm2_shutdown(chip, TPM2_SU_CLEAR);
-		chip->ops = NULL;
-		up_write(&chip->ops_sem);
-	}
+	chip->ops = NULL;
+	up_write(&chip->ops_sem);
 
 	return 0;
 }
-- 
2.20.1

Re: [PATCH v4 3/3] tpm: Fix TPM 1.2 Shutdown sequence to prevent future TPM operations

[Greg Kroah-Hartman]

On Thu, Oct 10, 2019 at 12:28:31AM +0300, Jarkko Sakkinen 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.
> 
> Fixes: d1bd4a792d39 ("tpm: Issue a TPM2_Shutdown for TPM2 devices.")
> Cc: stable@vger.kernel.org
> Signed-off-by: Vadim Sukhomlinov <sukhomlinov@google.com>
> [dianders: resolved merge conflicts with mainline]
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
>  drivers/char/tpm/tpm-chip.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)

This is already in the 4.14.148 4.19.78 5.1.18 5.2.1 5.3 releases.

thansk,

greg k-h

Re: [PATCH v4 3/3] tpm: Fix TPM 1.2 Shutdown sequence to prevent future TPM operations

[Jarkko Sakkinen]

On Thu, Oct 10, 2019 at 10:28:07AM +0200, Greg Kroah-Hartman wrote:
> On Thu, Oct 10, 2019 at 12:28:31AM +0300, Jarkko Sakkinen 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.
> > 
> > Fixes: d1bd4a792d39 ("tpm: Issue a TPM2_Shutdown for TPM2 devices.")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Vadim Sukhomlinov <sukhomlinov@google.com>
> > [dianders: resolved merge conflicts with mainline]
> > Signed-off-by: Douglas Anderson <dianders@chromium.org>
> > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > ---
> >  drivers/char/tpm/tpm-chip.c | 9 ++++-----
> >  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> This is already in the 4.14.148 4.19.78 5.1.18 5.2.1 5.3 releases.

There was one extra NULL assigment (non op). Nothing critical.

/Jarkko