[PATCH] cpufreq: initialize policy rwsem before sysfs publication

[Runyu Xiao]

cpufreq_policy_alloc() initializes policy->rwsem after
kobject_init_and_add() has created the policy sysfs directory and its
default attributes. A sysfs access can therefore reach a policy callback
before the semaphore has been initialized.

Initialize policy->rwsem before publishing the policy kobject so sysfs
callbacks always see an initialized semaphore.

Fixes: ad7722dab729 ("cpufreq: create per policy rwsem instead of per CPU cpu_policy_rwsem")
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: Codex:GPT-5
Signed-off-by: Runyu Xiao <runyu.xiao@xxxxxxxxxx>
---
 drivers/cpufreq/cpufreq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 0d0df986f..9efbf5b17 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1258,6 +1258,8 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
 	if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
 		goto err_free_rcpumask;
 
+	init_rwsem(&policy->rwsem);
+
 	init_completion(&policy->kobj_unregister);
 	ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
 				   cpufreq_global_kobject, "policy%u", cpu);
@@ -1272,8 +1274,6 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
 		goto err_free_real_cpus;
 	}
 
-	init_rwsem(&policy->rwsem);
-
 	freq_constraints_init(&policy->constraints);
 
 	policy->nb_min.notifier_call = cpufreq_notifier_min;
-- 
2.34.1