4.19-stable review patch. If anyone has any objections, please let me know.
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From: Dmitry Osipenko digetx@gmail.com
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: stable@vger.kernel.org # v4.17+ Fixes: 8ea229511e06 ("thermal: Add cooling device's statistics in sysfs") Signed-off-by: Dmitry Osipenko digetx@gmail.com Acked-by: Viresh Kumar viresh.kumar@linaro.org Acked-by: Eduardo Valentin edubezval@gmail.com Signed-off-by: Zhang Rui rui.zhang@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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);