Patch "cpufreq: amd-pstate: add check for cpufreq_cpu_get's return value" has been added to the 6.11-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    cpufreq: amd-pstate: add check for cpufreq_cpu_get's return value

to the 6.11-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     cpufreq-amd-pstate-add-check-for-cpufreq_cpu_get-s-r.patch
and it can be found in the queue-6.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit a5aef7e74d9144cf76e0648bb95729cdd743eaca
Author: Anastasia Belova <abelova@xxxxxxxxxxxxx>
Date:   Mon Aug 26 16:38:41 2024 +0300

    cpufreq: amd-pstate: add check for cpufreq_cpu_get's return value
    
    [ Upstream commit 5493f9714e4cdaf0ee7cec15899a231400cb1a9f ]
    
    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@xxxxxxxxxxxxx>
    Reviewed-by: Perry Yuan <perry.yuan@xxxxxxx>
    Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 073ca9caf52ac..589fde37ccd7a 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -659,7 +659,12 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 	unsigned long max_perf, min_perf, des_perf,
 		      cap_perf, lowest_nonlinear_perf;
 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
-	struct amd_cpudata *cpudata = policy->driver_data;
+	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);
@@ -873,11 +878,16 @@ static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata)
 static void amd_pstate_update_limits(unsigned int cpu)
 {
 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
-	struct amd_cpudata *cpudata = policy->driver_data;
+	struct amd_cpudata *cpudata;
 	u32 prev_high = 0, cur_high = 0;
 	int ret;
 	bool highest_perf_changed = false;
 
+	if (!policy)
+		return;
+
+	cpudata = policy->driver_data;
+
 	mutex_lock(&amd_pstate_driver_lock);
 	if ((!amd_pstate_prefcore) || (!cpudata->hw_prefcore))
 		goto free_cpufreq_put;