Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

iio:humidity:hts221: rearrange iio trigger get and register

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>

authored by

Dmitry Rokosov and committed by
Jonathan Cameron
10b9c2c3 d710359c

+4 -1
+4 -1
drivers/iio/humidity/hts221_buffer.c
··· 135 135 136 136 iio_trigger_set_drvdata(hw->trig, iio_dev); 137 137 hw->trig->ops = &hts221_trigger_ops; 138 + 139 + err = devm_iio_trigger_register(hw->dev, hw->trig); 140 + 138 141 iio_dev->trig = iio_trigger_get(hw->trig); 139 142 140 - return devm_iio_trigger_register(hw->dev, hw->trig); 143 + return err; 141 144 } 142 145 143 146 static int hts221_buffer_preenable(struct iio_dev *iio_dev)