tpm: fix up the tpm_class shutdown_pre pointer when created

Do not wait until long after the struct class has been created to set
the shutdown_pre pointer for the tpm_class, assign it right away.

This is the only in-kernel offender that tries to modify the
device->class pointer contents after it has been assigned to a device,
so fix that up by doing the function pointer assignment before it is
matched with the device.  Because of this, the patch should go through
the driver core tree to allow later changes to struct device to be
possible.

Cc: Peter Huewe <peterhuewe@gmx.de>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-integrity@vger.kernel.org
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-10-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index b99f55f2d4fd..7c444209a256 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -282,7 +282,7 @@ static void tpm_dev_release(struct device *dev)
  *
  * Return: always 0 (i.e. success)
  */
-static int tpm_class_shutdown(struct device *dev)
+int tpm_class_shutdown(struct device *dev)
 {
 	struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
 
@@ -337,7 +337,6 @@ struct tpm_chip *tpm_chip_alloc(struct device *pdev,
 	device_initialize(&chip->dev);
 
 	chip->dev.class = tpm_class;
-	chip->dev.class->shutdown_pre = tpm_class_shutdown;
 	chip->dev.release = tpm_dev_release;
 	chip->dev.parent = pdev;
 	chip->dev.groups = chip->groups;