diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 1da5f4980b92..a373654da841 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -378,12 +378,15 @@ static inline bool is_in_v2_mode(void)
 static void guarantee_online_cpus(struct task_struct *tsk,
 				  struct cpumask *pmask)
 {
-	struct cpuset *cs = task_cs(tsk);
 	const struct cpumask *possible_mask = task_cpu_possible_mask(tsk);
+	struct cpuset *cs;
 
 	if (WARN_ON(!cpumask_and(pmask, possible_mask, cpu_active_mask)))
 		cpumask_copy(pmask, cpu_active_mask);
 
+	rcu_read_lock();
+	cs = task_cs(tsk);
+
 	while (!cpumask_intersects(cs->effective_cpus, pmask)) {
 		cs = parent_cs(cs);
 		if (unlikely(!cs)) {
@@ -394,10 +397,13 @@ static void guarantee_online_cpus(struct task_struct *tsk,
 			 * cpuset's effective_cpus is on its way to be
 			 * identical to cpu_online_mask.
 			 */
-			return;
+			goto out_unlock;
 		}
 	}
 	cpumask_and(pmask, pmask, cs->effective_cpus);
+
+out_unlock:
+	rcu_read_unlock();
 }
 
 /*