cpufreq: CPPC: Fix possible null-ptr-deref for cpufreq_cpu_get_raw()

cpufreq_cpu_get_raw() may return NULL if the cpu is not in
policy->cpus cpu mask and it will cause null pointer dereference.

Fixes: 740fcdc2c20e ("cpufreq: CPPC: Register EM based on efficiency class information")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index fd3e328a2d578835a370579bc50608f14038a2be..309cca11b2396ebe3f540e91f2d25b88119a6125 100644 (file)
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -404,6 +404,9 @@ static int cppc_get_cpu_power(struct device *cpu_dev,
        struct cppc_cpudata *cpu_data;
 
        policy = cpufreq_cpu_get_raw(cpu_dev->id);
+       if (!policy)
+               return 0;
+
        cpu_data = policy->driver_data;
        perf_caps = &cpu_data->perf_caps;
        max_cap = arch_scale_cpu_capacity(cpu_dev->id);