From: Dmitry Rokosov DDRokosov@sberdevices.ru
stable inclusion from stable-v5.10.127 commit 42caf44906d6de02c4649e98e4a8bd03c4c53fa1 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5XDDK
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 9354c224c9b4f55847a0de3e968cba2ebf15af3b 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: 47196620c82f ("iio: mxc4005: add data ready trigger for mxc4005") Signed-off-by: Dmitry Rokosov ddrokosov@sberdevices.ru Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Link: https://lore.kernel.org/r/20220524181150.9240-4-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 Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Wei Li liwei391@huawei.com --- drivers/iio/accel/mxc4005.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c index 5a2b0ffbb145..ecd9d8ad5928 100644 --- a/drivers/iio/accel/mxc4005.c +++ b/drivers/iio/accel/mxc4005.c @@ -461,8 +461,6 @@ static int mxc4005_probe(struct i2c_client *client, data->dready_trig->dev.parent = &client->dev; data->dready_trig->ops = &mxc4005_trigger_ops; iio_trigger_set_drvdata(data->dready_trig, indio_dev); - indio_dev->trig = data->dready_trig; - iio_trigger_get(indio_dev->trig); ret = devm_iio_trigger_register(&client->dev, data->dready_trig); if (ret) { @@ -470,6 +468,8 @@ static int mxc4005_probe(struct i2c_client *client, "failed to register trigger\n"); return ret; } + + indio_dev->trig = iio_trigger_get(data->dready_trig); }
return devm_iio_device_register(&client->dev, indio_dev);