This is a note to let you know that I've just added the patch titled
vTPM: Fix missing NULL check
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
vtpm-fix-missing-null-check.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 31574d321c70f6d3b40fe98f9b2eafd9a903fef9 Mon Sep 17 00:00:00 2001
From: "Hon Ching \\(Vicky\\) Lo" <honclo@xxxxxxxxxxxxxxxxxx>
Date: Wed, 15 Mar 2017 01:28:07 -0400
Subject: vTPM: Fix missing NULL check
From: Hon Ching \(Vicky\) Lo <honclo@xxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Jarkko Sakkine <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm_ibmvtpm.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
--- 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
}
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
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;
Patches currently in stable-queue which might be from honclo@xxxxxxxxxxxxxxxxxx are
queue-4.9/vtpm-fix-missing-null-check.patch