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.
Cc: 4.2+ <stable@xxxxxxxxxxxxxxx> # 4.2+
Fixes: 02373d7c69b4 ("thermal: cpu_cooling: fix lockdep problems in cpu_cooling")
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Tested-by: Lukasz Luba <lukasz.luba@xxxxxxx>
---
drivers/thermal/cpu_cooling.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index 69d0f430b2d1..be29489dd247 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -153,8 +153,10 @@ unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
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);
--
2.12.0.432.g71c3a4f4ba37