iio: mma8452: Fix trigger reference couting

commit cd00822357 upstream.

The mma8452 driver directly assigns a trigger to the struct iio_dev. The
IIO core when done using this trigger will call `iio_trigger_put()` to drop
the reference count by 1.

Without the matching `iio_trigger_get()` in the driver the reference count
can reach 0 too early, the trigger gets freed while still in use and a
use-after-free occurs.

Fix this by getting a reference to the trigger before assigning it to the
IIO device.

Fixes: ae6d9ce056 ("iio: mma8452: Add support for interrupt driven triggers.")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211024092700.6844-1-lars@metafoo.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lars-Peter Clausen 2021-10-24 11:26:59 +02:00 committed by Greg Kroah-Hartman
parent 4e78529110
commit db12d95085

View file

@ -1473,7 +1473,7 @@ static int mma8452_trigger_setup(struct iio_dev *indio_dev)
if (ret)
return ret;
indio_dev->trig = trig;
indio_dev->trig = iio_trigger_get(trig);
return 0;
}