ipv6: Consider sk_bound_dev_if when binding a raw socket to an address

BugLink: https://bugs.launchpad.net/bugs/1832661

[ Upstream commit 72f7cfab ]

IPv6 does not consider if the socket is bound to a device when binding
to an address. The result is that a socket can be bound to eth0 and
then bound to the address of eth1. If the device is a VRF, the result
is that a socket can only be bound to an address in the default VRF.

Resolve by considering the device if sk_bound_dev_if is set.
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

net/ipv6/raw.c

@@ -284,7 +284,9 @@ static int rawv6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 			/* Binding to link-local address requires an interface */
 			if (!sk->sk_bound_dev_if)
 				goto out_unlock;
+		}
 
+		if (sk->sk_bound_dev_if) {
 			err = -ENODEV;
 			dev = dev_get_by_index_rcu(sock_net(sk),
 						   sk->sk_bound_dev_if);