mac80211: Ensure enough headroom when forwarding mesh pkt

When a buffer is duplicated during MESH packet forwarding,
this patch ensures that the new buffer has enough headroom.
Signed-off-by: Cedric Izoard <cedric.izoard@ceva-dsp.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rx.c

@@ -2472,7 +2472,7 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
 	if (!ifmsh->mshcfg.dot11MeshForwarding)
 		goto out;
 
-	fwd_skb = skb_copy(skb, GFP_ATOMIC);
+	fwd_skb = skb_copy_expand(skb, local->tx_headroom, 0, GFP_ATOMIC);
 	if (!fwd_skb) {
 		net_info_ratelimited("%s: failed to clone mesh frame\n",
 				    sdata->name);