wifi: mac80211: fix mesh forwarding

Linearize packets (needed for forwarding A-MSDU subframes).

Fixes: 986e43b19a ("wifi: mac80211: fix receiving A-MSDU frames on mesh interfaces")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20230324120924.38412-1-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rx.c

@@ -2833,6 +2833,9 @@ ieee80211_rx_mesh_data(struct ieee80211_sub_if_data *sdata, struct sta_info *sta
 
 		if (skb_cow_head(fwd_skb, hdrlen - sizeof(struct ethhdr)))
 			return RX_DROP_UNUSABLE;
+
+		if (skb_linearize(fwd_skb))
+			return RX_DROP_UNUSABLE;
 	}
 
 	fwd_hdr = skb_push(fwd_skb, hdrlen - sizeof(struct ethhdr));