diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index c466d255f786..2a4331a08494 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -408,7 +408,7 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 	bool existing = false;
 	struct nlattr *tb[TCA_QFQ_MAX + 1];
 	struct qfq_aggregate *new_agg = NULL;
-	u32 weight, lmax, inv_w;
+	u32 weight, lmax, inv_w, old_weight, old_lmax;
 	int err;
 	int delta_w;
 
@@ -444,12 +444,16 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 	inv_w = ONE_FP / weight;
 	weight = ONE_FP / inv_w;
 
-	if (cl != NULL &&
-	    lmax == cl->agg->lmax &&
-	    weight == cl->agg->class_weight)
-		return 0; /* nothing to change */
+	if (cl != NULL) {
+		sch_tree_lock(sch);
+		old_weight = cl->agg->class_weight;
+		old_lmax   = cl->agg->lmax;
+		sch_tree_unlock(sch);
+		if (lmax == old_lmax && weight == old_weight)
+			return 0; /* nothing to change */
+	}
 
-	delta_w = weight - (cl ? cl->agg->class_weight : 0);
+	delta_w = weight - (cl ? old_weight : 0);
 
 	if (q->wsum + delta_w > QFQ_MAX_WSUM) {
 		pr_notice("qfq: total weight out of range (%d + %u)\n",
@@ -550,10 +554,10 @@ static int qfq_delete_class(struct Qdisc *sch, unsigned long arg)
 
 	qdisc_purge_queue(cl->qdisc);
 	qdisc_class_hash_remove(&q->clhash, &cl->common);
+	qfq_destroy_class(sch, cl);
 
 	sch_tree_unlock(sch);
 
-	qfq_destroy_class(sch, cl);
 	return 0;
 }
 
@@ -620,6 +624,7 @@ static int qfq_dump_class(struct Qdisc *sch, unsigned long arg,
 {
 	struct qfq_class *cl = (struct qfq_class *)arg;
 	struct nlattr *nest;
+	u32 class_weight, lmax;
 
 	tcm->tcm_parent	= TC_H_ROOT;
 	tcm->tcm_handle	= cl->common.classid;
@@ -628,8 +633,13 @@ static int qfq_dump_class(struct Qdisc *sch, unsigned long arg,
 	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 	if (nest == NULL)
 		goto nla_put_failure;
-	if (nla_put_u32(skb, TCA_QFQ_WEIGHT, cl->agg->class_weight) ||
-	    nla_put_u32(skb, TCA_QFQ_LMAX, cl->agg->lmax))
+
+	sch_tree_lock(sch);
+	class_weight	= cl->agg->class_weight;
+	lmax		= cl->agg->lmax;
+	sch_tree_unlock(sch);
+	if (nla_put_u32(skb, TCA_QFQ_WEIGHT, class_weight) ||
+	    nla_put_u32(skb, TCA_QFQ_LMAX, lmax))
 		goto nla_put_failure;
 	return nla_nest_end(skb, nest);
 
@@ -646,8 +656,10 @@ static int qfq_dump_class_stats(struct Qdisc *sch, unsigned long arg,
 
 	memset(&xstats, 0, sizeof(xstats));
 
+	sch_tree_lock(sch);
 	xstats.weight = cl->agg->class_weight;
 	xstats.lmax = cl->agg->lmax;
+	sch_tree_unlock(sch);
 
 	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
 				  d, NULL, &cl->bstats) < 0 ||