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| author | Hon Ching \(Vicky\) Lo <honclo@linux.vnet.ibm.com> | 2017-03-15 08:28:07 +0300 |
|---|---|---|
| committer | Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> | 2017-04-03 22:46:02 +0300 |
| commit | 31574d321c70f6d3b40fe98f9b2eafd9a903fef9 (patch) | |
| tree | 9b87dc75357ad6ad4d4fc4bee8361b968e6b4c5f /drivers/char/tpm | |
| parent | 8569defde8057258835c51ce01a33de82e14b148 (diff) | |
| download | linux-31574d321c70f6d3b40fe98f9b2eafd9a903fef9.tar.xz | |
vTPM: Fix missing NULL check
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>
Reviewed-by: Jarkko Sakkine <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Diffstat (limited to 'drivers/char/tpm')
| -rw-r--r-- | drivers/char/tpm/tpm_ibmvtpm.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index 1b9d61ffe991..f01d083eced2 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.c +++ b/drivers/char/tpm/tpm_ibmvtpm.c @@ -299,6 +299,8 @@ 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; } @@ -313,14 +315,16 @@ 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) + if (chip) + ibmvtpm = dev_get_drvdata(&chip->dev); + else return CRQ_RES_BUF_SIZE + PAGE_SIZE; return CRQ_RES_BUF_SIZE + ibmvtpm->rtce_size; |