From: Dmitry Rokosov DDRokosov@sberdevices.ru
commit 10b9c2c33ac706face458feab8965f11743c98c0 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: e4a70e3e7d84 ("iio: humidity: add support to hts221 rh/temp combo device") Signed-off-by: Dmitry Rokosov ddrokosov@sberdevices.ru Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Link: https://lore.kernel.org/r/20220524181150.9240-6-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/humidity/hts221_buffer.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/iio/humidity/hts221_buffer.c +++ b/drivers/iio/humidity/hts221_buffer.c @@ -135,9 +135,12 @@ int hts221_allocate_trigger(struct iio_d
iio_trigger_set_drvdata(hw->trig, iio_dev); hw->trig->ops = &hts221_trigger_ops; + + err = devm_iio_trigger_register(hw->dev, hw->trig); + iio_dev->trig = iio_trigger_get(hw->trig);
- return devm_iio_trigger_register(hw->dev, hw->trig); + return err; }
static int hts221_buffer_preenable(struct iio_dev *iio_dev)