[PATCH] tpm: check the chip reference before using it

Andi Shyti
2012-05-28T16:23:24Z

If a driver calls tpm_dev_vendor_release for a device already released
then the driver will oops.

Signed-off-by: Andi Shyti <andi.shyti@gmail.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
---
drivers/char/tpm/tpm.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index ad7c732..66e4c12 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -1322,6 +1322,9 @@ EXPORT_SYMBOL_GPL(tpm_pm_resume);

void tpm_dev_vendor_release(struct tpm_chip *chip)
{
+ if (!chip)
+ return;
+
if (chip->vendor.release)
chip->vendor.release(chip->dev);

@@ -1337,6 +1340,9 @@ EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
*/
void tpm_dev_release(struct device *dev)
{
+ if (!chip)
+ return;
+
struct tpm_chip *chip = dev_get_drvdata(dev);

tpm_dev_vendor_release(chip);
--
1.7.10