[PATCH 5.15 097/135] iio:accel:kxcjk-1013: rearrange iio trigger get and register

Greg Kroah-Hartman
2022-06-27T11:44:20Z

From: Dmitry Rokosov <DDRokosov@sberdevices.ru>

commit ed302925d708f2f97ae5e9fd6c56c16bb34f6629 upstream.

IIO trigger interface function iio_trigger_get() should be called after
iio_trigger_register() (or its devm analogue) strictly, because of
iio_trigger_get() acquires module refcnt based on the trigger->owner
pointer, which is initialized inside iio_trigger_register() to
THIS_MODULE.
If this call order is wrong, the next iio_trigger_put() (from sysfs
callback or "delete module" path) will dereference "default" module
refcnt, which is incorrect behaviour.

Fixes: c1288b833881 ("iio: accel: kxcjk-1013: Increment ref counter for indio_dev->trig")
Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220524181150.9240-3-ddrokosov@sberdevices.ru
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iio/accel/kxcjk-1013.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/iio/accel/kxcjk-1013.c
+++ b/drivers/iio/accel/kxcjk-1013.c
@@ -1553,12 +1553,12 @@ static int kxcjk1013_probe(struct i2c_cl

data->dready_trig->ops = &kxcjk1013_trigger_ops;
iio_trigger_set_drvdata(data->dready_trig, indio_dev);
- indio_dev->trig = data->dready_trig;
- iio_trigger_get(indio_dev->trig);
ret = iio_trigger_register(data->dready_trig);
if (ret)
goto err_poweroff;

+ indio_dev->trig = iio_trigger_get(data->dready_trig);
+
data->motion_trig->ops = &kxcjk1013_trigger_ops;
iio_trigger_set_drvdata(data->motion_trig, indio_dev);
ret = iio_trigger_register(data->motion_trig);