This patch fixes use-after-free that was detected by KASAN. The bug is triggered on a CPUFreq driver module unload by freeing 'cdev' on device unregister and then using the freed structure during of the cdev's sysfs data destruction. The solution is to unregister the sysfs at first, then destroy sysfs data and finally release the cooling device.
Cc: <[email protected]> # v4.17+ Fixes: 8ea229511e06 ("thermal: Add cooling device's statistics in sysfs") Signed-off-by: Dmitry Osipenko <[email protected]> --- drivers/thermal/thermal_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index 6ab982309e6a..441778100887 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -1102,8 +1102,9 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev) mutex_unlock(&thermal_list_lock); ida_simple_remove(&thermal_cdev_ida, cdev->id); - device_unregister(&cdev->device); + device_del(&cdev->device); thermal_cooling_device_destroy_sysfs(cdev); + put_device(&cdev->device); } EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister); -- 2.18.0
