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author | Viresh Kumar <viresh.kumar@linaro.org> | 2017-04-25 12:27:08 +0200 |
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committer | Eduardo Valentin <edubezval@gmail.com> | 2017-05-28 02:31:05 +0200 |
commit | 289d72afddf83440117c35d864bf0c6309c1d011 (patch) | |
tree | 2a3db987ebd7578a074d15c1aafe8680250f3557 /drivers/thermal/cpu_cooling.c | |
parent | Linux 4.12-rc1 (diff) | |
download | linux-289d72afddf83440117c35d864bf0c6309c1d011.tar.xz linux-289d72afddf83440117c35d864bf0c6309c1d011.zip |
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: 02373d7c69b4 ("thermal: cpu_cooling: fix lockdep problems in cpu_cooling")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Diffstat (limited to 'drivers/thermal/cpu_cooling.c')
-rw-r--r-- | drivers/thermal/cpu_cooling.c | 4 |
1 files changed, 3 insertions, 1 deletions
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); |