diff options
| author | Hon Ching \(Vicky) Lo <honclo@linux.vnet.ibm.com> | 2017-03-15 01:28:07 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-24 07:11:17 +0200 |
| commit | 7dfe7ca9ec12b7dbd4fdefa7f3cc60e0ec08ba3b (patch) | |
| tree | 28f8c455d88b3e2dbb3c297b7843790fdd7027f8 | |
| parent | ecae47331a431b0295905add457a06e766310f71 (diff) | |
vTPM: Fix missing NULL check
commit 31574d321c70f6d3b40fe98f9b2eafd9a903fef9 upstream.
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")
Signed-off-by: Hon Ching(Vicky) Lo <honclo@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkine <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/char/tpm/tpm_ibmvtpm.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index 946025a7413b..84eca4f93b82 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.c +++ b/drivers/char/tpm/tpm_ibmvtpm.c @@ -295,6 +295,8 @@ static int tpm_ibmvtpm_remove(struct vio_dev *vdev) } kfree(ibmvtpm); + /* For tpm_ibmvtpm_get_desired_dma */ + dev_set_drvdata(&vdev->dev, NULL); return 0; } @@ -309,13 +311,16 @@ 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; - /* ibmvtpm initializes at probe time, so the data we are - * asking for may not be set yet. Estimate that 4K required - * for TCE-mapped buffer in addition to CRQ. - */ - if (!ibmvtpm) + /* + * ibmvtpm initializes at probe time, so the data we are + * asking for may not be set yet. Estimate that 4K required + * for TCE-mapped buffer in addition to CRQ. + */ + if (chip) + ibmvtpm = dev_get_drvdata(&chip->dev); + else return CRQ_RES_BUF_SIZE + PAGE_SIZE; return CRQ_RES_BUF_SIZE + ibmvtpm->rtce_size; |