team: loadbalance: push lacpdus to exact delivery

When team is in bridge and LACP is utilized, LACPDU packets are pushed
to userspace using raw socket and there they are processed. However,
since 8626c56c, LACPDU skbs are dropped by bridge rx_handler so
they never reach packet handlers in rx path. Fix this by explicity treat
LACPDUs to be pushed to exact delivery in team rx_handler.
Reported-by: Ido Schimmel <idosch@mellanox.com>
Fixes: 8626c56c ("bridge: fix potential use-after-free when hook returns QUEUE or STOLEN verdict")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/team/team_mode_loadbalance.c

@@ -14,9 +14,23 @@
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/netdevice.h>
+#include <linux/etherdevice.h>
 #include <linux/filter.h>
 #include <linux/if_team.h>
 
+static rx_handler_result_t lb_receive(struct team *team, struct team_port *port,
+				      struct sk_buff *skb)
+{
+	if (unlikely(skb->protocol == htons(ETH_P_SLOW))) {
+		/* LACPDU packets should go to exact delivery */
+		const unsigned char *dest = eth_hdr(skb)->h_dest;
+
+		if (is_link_local_ether_addr(dest) && dest[5] == 0x02)
+			return RX_HANDLER_EXACT;
+	}
+	return RX_HANDLER_ANOTHER;
+}
+
 struct lb_priv;
 
 typedef struct team_port *lb_select_tx_port_func_t(struct team *,
@@ -652,6 +666,7 @@ static const struct team_mode_ops lb_mode_ops = {
 	.port_enter		= lb_port_enter,
 	.port_leave		= lb_port_leave,
 	.port_disabled		= lb_port_disabled,
+	.receive		= lb_receive,
 	.transmit		= lb_transmit,
 };