diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 04e9ef088535..4b8710a266cc 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -847,7 +847,7 @@ static struct tc_u_knode *u32_init_knode(struct net *net, struct tcf_proto *tp,
 	/* Similarly success statistics must be moved as pointers */
 	new->pcpu_success = n->pcpu_success;
 #endif
-	memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
+	memcpy(&new->sel, s, struct_size(s, keys, s->nkeys));
 
 	if (tcf_exts_init(&new->exts, net, TCA_U32_ACT, TCA_U32_POLICE)) {
 		kfree(new);