diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index 572fe25..c403c87 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -572,8 +572,10 @@
 	struct atm_flow_data *flow, *tmp;
 
 	pr_debug("atm_tc_destroy(sch %p,[qdisc %p])\n", sch, p);
-	list_for_each_entry(flow, &p->flows, list)
+	list_for_each_entry(flow, &p->flows, list) {
 		tcf_block_put(flow->block);
+		flow->block = NULL;
+	}
 
 	list_for_each_entry_safe(flow, tmp, &p->flows, list) {
 		if (flow->ref > 1)