diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 4f522143811e..7416a5c73b2a 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -134,10 +134,12 @@ next_knode:
 #endif
 
 		for (i = n->sel.nkeys; i>0; i--, key++) {
-			unsigned int toff;
+			int toff = off + key->off + (off2 & key->offmask);
 			__be32 *data, _data;
 
-			toff = off + key->off + (off2 & key->offmask);
+			if (skb_headroom(skb) + toff < 0)
+				goto out;
+
 			data = skb_header_pointer(skb, toff, 4, &_data);
 			if (!data)
 				goto out;