u32: negative offset fix

[net-next-2.6.git] / net / sched / cls_u32.c

diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 4f522143811e467fe70e7e4b13db47f979b11b8a..7416a5c73b2a993550991ac66eca7cc254c6f2e6 100644 (file)
--- 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;