Commit 289d72af authored by Viresh Kumar's avatar Viresh Kumar Committed by Eduardo Valentin

thermal: cpu_cooling: Avoid accessing potentially freed structures

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@vger.kernel.org> # 4.2+
Fixes: 02373d7c ("thermal: cpu_cooling: fix lockdep problems in cpu_cooling")
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: default avatarLukasz Luba <lukasz.luba@arm.com>
Tested-by: default avatarLukasz Luba <lukasz.luba@arm.com>
Signed-off-by: default avatarEduardo Valentin <edubezval@gmail.com>
parent 2ea659a9
...@@ -153,8 +153,10 @@ unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq) ...@@ -153,8 +153,10 @@ unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
mutex_lock(&cooling_list_lock); mutex_lock(&cooling_list_lock);
list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) { list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) {
if (cpumask_test_cpu(cpu, &cpufreq_dev->allowed_cpus)) { if (cpumask_test_cpu(cpu, &cpufreq_dev->allowed_cpus)) {
unsigned long level = get_level(cpufreq_dev, freq);
mutex_unlock(&cooling_list_lock); mutex_unlock(&cooling_list_lock);
return get_level(cpufreq_dev, freq); return level;
} }
} }
mutex_unlock(&cooling_list_lock); mutex_unlock(&cooling_list_lock);
......
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