4.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Viresh Kumar <viresh.kumar@xxxxxxxxxx> commit 289d72afddf83440117c35d864bf0c6309c1d011 upstream. After the lock is dropped, it is possible that the cpufreq_dev gets freed before we call get_level() and that can cause kernel to crash. Drop the lock after we are done using the structure. Fixes: 02373d7c69b4 ("thermal: cpu_cooling: fix lockdep problems in cpu_cooling") Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx> Reviewed-by: Lukasz Luba <lukasz.luba@xxxxxxx> Tested-by: Lukasz Luba <lukasz.luba@xxxxxxx> Signed-off-by: Eduardo Valentin <edubezval@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/thermal/cpu_cooling.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/thermal/cpu_cooling.c +++ b/drivers/thermal/cpu_cooling.c @@ -153,8 +153,10 @@ unsigned long cpufreq_cooling_get_level( mutex_lock(&cooling_list_lock); list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) { if (cpumask_test_cpu(cpu, &cpufreq_dev->allowed_cpus)) { + unsigned long level = get_level(cpufreq_dev, freq); + mutex_unlock(&cooling_list_lock); - return get_level(cpufreq_dev, freq); + return level; } } mutex_unlock(&cooling_list_lock);