[PATCH 6.6 11/43] cpufreq: amd-pstate: add check for cpufreq_cpu_gets return value

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Anastasia Belova <abelova@astralinux.ru>

commit 5493f9714e4cdaf0ee7cec15899a231400cb1a9f upstream.

cpufreq_cpu_get may return NULL. To avoid NULL-dereference check it
and return in case of error.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Anastasia Belova <abelova@astralinux.ru>
Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ Raj: on 6.6, there don't have function amd_pstate_update_limits()
  so applied the NULL checking in amd_pstate_adjust_perf() only ]
Signed-off-by: Rajani Kantha <rajanikantha@engineer.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/cpufreq/amd-pstate.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -579,8 +579,13 @@ static void amd_pstate_adjust_perf(unsig
 	unsigned long max_perf, min_perf, des_perf,
 		      cap_perf, lowest_nonlinear_perf, max_freq;
 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
-	struct amd_cpudata *cpudata = policy->driver_data;
 	unsigned int target_freq;
+	struct amd_cpudata *cpudata;
+
+	if (!policy)
+		return;
+
+	cpudata = policy->driver_data;
 
 	if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
 		amd_pstate_update_min_max_limit(policy);