[PATCH] cpufreq: scpi: Prevent null pointer dereference in scpi_cpufreq_get_rate()

[Charles Han]

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

Fixes: 343a8d17fa8d ("cpufreq: scpi: remove arm_big_little dependency")
Signed-off-by: Charles Han <hanchunchao at inspur.com>
---
 drivers/cpufreq/scpi-cpufreq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
index cd89c1b9832c..c888ed3a0de9 100644
--- a/drivers/cpufreq/scpi-cpufreq.c
+++ b/drivers/cpufreq/scpi-cpufreq.c
@@ -30,6 +30,9 @@ static struct scpi_ops *scpi_ops;
 static unsigned int scpi_cpufreq_get_rate(unsigned int cpu)
 {
 	struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
+	if (unlikely(!policy))
+		return 0;
+
 	struct scpi_data *priv = policy->driver_data;
 	unsigned long rate = clk_get_rate(priv->clk);
 
-- 
2.31.1