macvlan: fix leak in macvlan_handle_frame

commit e639b8d8 upstream.

Reset pskb in macvlan_handle_frame in case skb_share_check returned a
clone.

Fixes: 8a4eb573 ("net: introduce rx_handler results and logic around that")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/net/macvlan.c

@@ -284,6 +284,7 @@ static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb)
 		skb = ip_check_defrag(skb, IP_DEFRAG_MACVLAN);
 		if (!skb)
 			return RX_HANDLER_CONSUMED;
+		*pskb = skb;
 		eth = eth_hdr(skb);
 		src = macvlan_hash_lookup(port, eth->h_source);
 		if (src && src->mode != MACVLAN_MODE_VEPA &&
@@ -319,6 +320,7 @@ static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb)
 	if (!skb)
 		goto out;
 
+	*pskb = skb;
 	skb->dev = dev;
 	skb->pkt_type = PACKET_HOST;