diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 36fc0ff506c349d53f4f495aacdceef4702de470..78f6d18ff0af5f880d1b7085e11f5f6b527537ac 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -6162,7 +6162,7 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
 struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss)
 {
 	WARN_ON_ONCE(!rcu_read_lock_held());
-	return id > 0 ? idr_find(&ss->css_idr, id) : NULL;
+	return idr_find(&ss->css_idr, id);
 }
 
 /**