--- x/net/sched/sch_sfq.c
+++ y/net/sched/sch_sfq.c
@@ -720,6 +720,8 @@ static void sfq_destroy(struct Qdisc *sc
 {
 	struct sfq_sched_data *q = qdisc_priv(sch);
 
+	if (q->sch != sch)
+		return;
 	tcf_block_put(q->block);
 	q->perturb_period = 0;
 	del_timer_sync(&q->perturb_timer);