From: Sanjay Chitroda <redacted>
Avoid using devm_iio_device_register(), as this driver requires explicit
error handling and teardown ordering.
With devm_iio_device_register(), IIO device remains registered until the
devres cleanup phase. However, driver's remove() callback removes the
sensor hub callback and trigger support. This can create a race window
where IIO device is still visible and read_raw() requests are issued.
These requests might call sensor_hub_input_attr_get_raw_value(), which
waits up to 5 seconds for a response from the sensor hub callback that
has already been removed.
Add an explicit iio_device_unregister() call in the teardown path to
ensure deterministic cleanup, so that userspace can no longer access the
device once backend resources begin to be dismantled.
Fixes: 59d0f2da3569 ("iio: hid: Add temperature sensor support")
Cc: stable@vger.kernel.org
Reviewed-by: Maxwell Doose <m32285159@gmail.com>
Reviewed-by: Andy Shevchenko <redacted>
Signed-off-by: Sanjay Chitroda <redacted>
---
Changes in v2:
- Added review tags of Maxwell and Andy along with stable Cc
- Based on input from Srinivas and investigation use-after-free
explanation was not sufficiently justified so updated the commit
message with appropriate information and kept Fixes tag
- Link to v1: https://lore.kernel.org/all/20260622052135.1804135-1-sanjayembedded@gmail.com (local)
---
drivers/iio/temperature/hid-sensor-temperature.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/temperature/hid-sensor-temperature.c b/drivers/iio/temperature/hid-sensor-temperature.c
index a8d3a15f9c53..ab6ec8f659b8 100644
--- a/drivers/iio/temperature/hid-sensor-temperature.c
+++ b/drivers/iio/temperature/hid-sensor-temperature.c
@@ -244,7 +244,7 @@ static int hid_temperature_probe(struct platform_device *pdev)
if (ret)
goto error_remove_trigger;
- ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
+ ret = iio_device_register(indio_dev);
if (ret)
goto error_remove_callback;
@@ -264,6 +264,7 @@ static void hid_temperature_remove(struct platform_device *pdev)
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
struct temperature_state *temp_st = iio_priv(indio_dev);
+ iio_device_unregister(indio_dev);
sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TEMPERATURE);
hid_sensor_remove_trigger(indio_dev, &temp_st->common_attributes);
}
--
--