From 7cd7b56037ae4cbdfe5e7fa9e41b67ba15199d7f Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Tue, 25 Apr 2017 15:57:08 +0530 Subject: [PATCH] thermal: cpu_cooling: Avoid accessing potentially freed structures 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 Reviewed-by: Lukasz Luba Tested-by: Lukasz Luba Signed-off-by: Eduardo Valentin Signed-off-by: Greg Kroah-Hartman --- 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 9ce0e9e..f49d298 100644 --- a/drivers/thermal/cpu_cooling.c +++ b/drivers/thermal/cpu_cooling.c @@ -191,8 +191,10 @@ 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); -- 2.7.4