4.19-stable review patch. If anyone has any objections, please let me know.
------------------ From: Dmitry Osipenko <[email protected]> commit 3c587768271e9c20276522025729e4ebca51583b upstream. 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]> Acked-by: Viresh Kumar <[email protected]> Acked-by: Eduardo Valentin <[email protected]> Signed-off-by: Zhang Rui <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/thermal/thermal_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -1102,8 +1102,9 @@ void thermal_cooling_device_unregister(s 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);
