iio: imu: Use iio_trigger_get for indio_dev->trig assignment

This patch uses iio_trigger_get to increment the reference
count of trigger device, to avoid incorrect assignment.
Can result in a null pointer dereference during removal if the
trigger has been changed before removal.

This patch refers to a similar situation encountered through the
following discussion:
http://www.spinics.net/lists/linux-iio/msg13669.html

Signed-off-by: Darshana Padmadas <darshanapadmadas@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/imu/adis_trigger.c b/drivers/iio/imu/adis_trigger.c
index e0017c22bb9c6ce3b4f4f9c753a8ce1364621b19..f53e9a803a0e1ec1589a5b0ad25d7aa1f8d54e70 100644 (file)
--- a/drivers/iio/imu/adis_trigger.c
+++ b/drivers/iio/imu/adis_trigger.c
@@ -60,7 +60,7 @@ int adis_probe_trigger(struct adis *adis, struct iio_dev *indio_dev)
        iio_trigger_set_drvdata(adis->trig, adis);
        ret = iio_trigger_register(adis->trig);
 
-       indio_dev->trig = adis->trig;
+       indio_dev->trig = iio_trigger_get(adis->trig);
        if (ret)
                goto error_free_irq;