[PATCH v3 1/2] HID: sensor: custom: Fix use-after-free in enable_sensor

[Haoxiang Li <haoxiang_li2024@163.com>]

enable_sensor_store() can call set_power_report_state(), which
dereferences sensor_inst->power_state and sensor_inst->report_state.
These pointers refer to entries in sensor_inst->fields.

Create the field attributes before exposing the enable_sensor sysfs
attribute, so enable_sensor cannot be accessed before the state it
depends on has been initialized.

On remove, delete enable_sensor before freeing the field attributes,
so a concurrent sysfs write cannot dereference freed memory through
power_state or report_state.

Reported-by: Sashiko AI Review <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260623021950.1736413-1-haoxiang_li2024@163.com?part=1
Fixes: 4a7de0519df5 ("HID: sensor: Custom and Generic sensor support")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
---
 drivers/hid/hid-sensor-custom.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/hid/hid-sensor-custom.c b/drivers/hid/hid-sensor-custom.c
index afffea894021..6b0da2e0e1c9 100644
--- a/drivers/hid/hid-sensor-custom.c
+++ b/drivers/hid/hid-sensor-custom.c
@@ -1005,26 +1005,26 @@ static int hid_sensor_custom_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	ret = sysfs_create_group(&sensor_inst->pdev->dev.kobj,
-				 &enable_sensor_attr_group);
+	ret = hid_sensor_custom_add_attributes(sensor_inst);
 	if (ret)
 		goto err_remove_callback;
 
-	ret = hid_sensor_custom_add_attributes(sensor_inst);
+	ret = sysfs_create_group(&sensor_inst->pdev->dev.kobj,
+				 &enable_sensor_attr_group);
 	if (ret)
-		goto err_remove_group;
+		goto err_remove_attributes;
 
 	ret = hid_sensor_custom_dev_if_add(sensor_inst);
 	if (ret)
-		goto err_remove_attributes;
+		goto err_remove_group;
 
 	return 0;
 
-err_remove_attributes:
-	hid_sensor_custom_remove_attributes(sensor_inst);
 err_remove_group:
 	sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
 			   &enable_sensor_attr_group);
+err_remove_attributes:
+	hid_sensor_custom_remove_attributes(sensor_inst);
 err_remove_callback:
 	sensor_hub_remove_callback(hsdev, hsdev->usage);
 
@@ -1042,9 +1042,10 @@ static void hid_sensor_custom_remove(struct platform_device *pdev)
 	}
 
 	hid_sensor_custom_dev_if_remove(sensor_inst);
-	hid_sensor_custom_remove_attributes(sensor_inst);
+	/* Remove enable_sensor first as it uses fields via power_state/report_state. */
 	sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
 			   &enable_sensor_attr_group);
+	hid_sensor_custom_remove_attributes(sensor_inst);
 	sensor_hub_remove_callback(hsdev, hsdev->usage);
 }
 
-- 
2.25.1