vrf: prevent adding upper devices

[ Upstream commit 1017e0987117c32783ba7c10fe2e7ff1456ba1dc ]

VRF devices don't work with upper devices. Currently, it's possible to
add a VRF device to a bridge or team, and to create macvlan, macsec, or
ipvlan devices on top of a VRF (bond and vlan are prevented respectively
by the lack of an ndo_set_mac_address op and the NETIF_F_VLAN_CHALLENGED
feature flag).

Fix this by setting the IFF_NO_RX_HANDLER flag (introduced in commit
f5426250 ("net: introduce IFF_NO_RX_HANDLER")).

Cc: David Ahern <dsahern@gmail.com>
Fixes: 193125db ("net: Introduce VRF device driver")
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/vrf.c

@@ -1262,6 +1262,7 @@ static void vrf_setup(struct net_device *dev)
 
 	/* default to no qdisc; user can add if desired */
 	dev->priv_flags |= IFF_NO_QUEUE;
+	dev->priv_flags |= IFF_NO_RX_HANDLER;
 }
 
 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],