ACPI: video - fix potential crash when unloading
thermal_cooling_device_register() returns error encoded in a pointer
when it fails in which case we need to explictly set device->cdev
to NULL so we don't try to unregister it when unloading.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 2020907..aab3851 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -997,8 +997,18 @@
device->cdev = thermal_cooling_device_register("LCD",
device->dev, &video_cooling_ops);
- if (IS_ERR(device->cdev))
+ if (IS_ERR(device->cdev)) {
+ /*
+ * Set cdev to NULL so we don't crash trying to
+ * free it.
+ * Also, why the hell we are returning early and
+ * not attempt to register video output if cooling
+ * device registration failed?
+ * -- dtor
+ */
+ device->cdev = NULL;
return;
+ }
dev_info(&device->dev->dev, "registered as cooling_device%d\n",
device->cdev->id);