Commit f5deab10 authored Oct 24, 2021 by Lars-Peter Clausen Committed by Greg Kroah-Hartman Dec 14, 2021

iio: mma8452: Fix trigger reference couting



commit cd0082235783f814241a1c9483fb89e405f4f892 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: ae6d9ce0 ("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>

parent ed04c87d

drivers/iio/accel/mma8452.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -1470,7 +1470,7 @@ static int mma8452_trigger_setup(struct iio_dev *indio_dev)
	if (ret)		if (ret)
	return ret;		return ret;

	indio_dev->trig = trig;		indio_dev->trig = iio_trigger_get(trig);

	return 0;		return 0;
	}		}