[PATCH 5.10 365/798] iio: orientation: hid-sensor-rotation: Avoid race between callback setup and device exposure
flat view
COLD37d
REVIEWED: 2 (1M)
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2026-09-12 19:45:28
Also in:
linux-patches
Subsystem:
hid sensor hub drivers, iio subsystem and drivers, the rest · Maintainers:
Jiri Kosina, Jonathan Cameron, Srinivas Pandruvada, Linus Torvalds
2 review trailers (1 from subsystem maintainers).
5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sanjay Chitroda <redacted>
[ Upstream commit 0e32649a7cf3cd784862f8dc0c68a5134731bfff ]
The driver currently exposes the IIO device to userspace before
completing sensor hub callback registration, and similarly removes
callbacks while the device can still be accessed during teardown.
This creates a timing window where userspace may enable the buffer
before callbacks are available. In such cases:
- samples can be dropped,
- buffered reads may observe stale or no data.
Reorder probe and remove paths to ensure callbacks are active before
device exposure and are removed after device is no longer accessible.
This avoids a race window leading to data loss.
Signed-off-by: Sanjay Chitroda <redacted>
Fixes: fc18dddc0625 ("iio: hid-sensors: Added device rotation support")
Reviewed-by: Andy Shevchenko <redacted>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iio/orientation/hid-sensor-rotation.c | 20 +++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/iio/orientation/hid-sensor-rotation.c b/drivers/iio/orientation/hid-sensor-rotation.c
index b10204c147baf..2993db10582b1 100644
--- a/drivers/iio/orientation/hid-sensor-rotation.c
+++ b/drivers/iio/orientation/hid-sensor-rotation.c@@ -330,12 +330,6 @@ static int hid_dev_rot_probe(struct platform_device *pdev) return ret; } - ret = iio_device_register(indio_dev); - if (ret) { - dev_err(&pdev->dev, "device register failed\n"); - goto error_remove_trigger; - } - rot_state->callbacks.send_event = dev_rot_proc_event; rot_state->callbacks.capture_sample = dev_rot_capture_sample; rot_state->callbacks.pdev = pdev;
@@ -343,13 +337,19 @@ static int hid_dev_rot_probe(struct platform_device *pdev) &rot_state->callbacks); if (ret) { dev_err(&pdev->dev, "callback reg failed\n"); - goto error_iio_unreg; + goto error_remove_trigger; + } + + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(&pdev->dev, "device register failed\n"); + goto error_remove_callback; } return 0; -error_iio_unreg: - iio_device_unregister(indio_dev); +error_remove_callback: + sensor_hub_remove_callback(hsdev, hsdev->usage); error_remove_trigger: hid_sensor_remove_trigger(indio_dev, &rot_state->common_attributes); return ret;
@@ -362,8 +362,8 @@ static int hid_dev_rot_remove(struct platform_device *pdev) struct iio_dev *indio_dev = platform_get_drvdata(pdev); struct dev_rot_state *rot_state = iio_priv(indio_dev); - sensor_hub_remove_callback(hsdev, hsdev->usage); iio_device_unregister(indio_dev); + sensor_hub_remove_callback(hsdev, hsdev->usage); hid_sensor_remove_trigger(indio_dev, &rot_state->common_attributes); return 0;
--
2.53.0