| Message ID | 1488839535-11822-1-git-send-email-honclo@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index 1b9d61f..a88ee25 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.c +++ b/drivers/char/tpm/tpm_ibmvtpm.c @@ -313,7 +313,10 @@ static int tpm_ibmvtpm_remove(struct vio_dev *vdev) static unsigned long tpm_ibmvtpm_get_desired_dma(struct vio_dev *vdev) { struct tpm_chip *chip = dev_get_drvdata(&vdev->dev); - struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev); + struct ibmvtpm_dev *ibmvtpm = NULL; + + if (chip) + ibmvtpm = dev_get_drvdata(&chip->dev); /* * ibmvtpm initializes at probe time, so the data we are
The current code passes the address of tpm_chip as the argument to dev_get_drvdata() without prior NULL check in tpm_ibmvtpm_get_desired_dma. This resulted an oops during kernel boot when vTPM is enabled in Power partition configured in active memory sharing mode. The vio_driver's get_desired_dma() is called before the probe(), which for vtpm is tpm_ibmvtpm_probe, and it's this latter function that initializes the driver and set data. Attempting to get data before the probe() caused the problem. This patch adds a NULL check to the tpm_ibmvtpm_get_desired_dma. fixes: 9e0d39d8a6a0 ("tpm: Remove useless priv field in struct tpm_vendor_specific") Cc: <stable@vger.kernel.org> Signed-off-by: Hon Ching(Vicky) Lo <honclo@linux.vnet.ibm.com> --- drivers/char/tpm/tpm_ibmvtpm.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-)