diff --git a/include/linux/pid.h b/include/linux/pid.h
index f5476d7140a3..a0458c713e4e 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -273,7 +273,7 @@ static inline pid_t task_tgid_nr(struct task_struct *tsk)
  */
 static inline int pid_alive(const struct task_struct *p)
 {
-	return p->thread_pid != NULL;
+	return READ_ONCE(p->thread_pid) != NULL;
 }
 
 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
diff --git a/kernel/pid.c b/kernel/pid.c
index 95b8ccfa8269..adf721606768 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -411,7 +411,7 @@ static void __change_pid(struct pid **pids, struct task_struct *task,
 	pid = *pid_ptr;
 
 	hlist_del_rcu(&task->pid_links[type]);
-	*pid_ptr = new;
+	WRITE_ONCE(*pid_ptr, new);
 
 	for (tmp = PIDTYPE_MAX; --tmp >= 0; )
 		if (pid_has_task(pid, tmp))