ipv6: Consider sk_bound_dev_if when binding a socket to an address

dsahern · davem330 · commit c5ee066333eb · 2019-01-02T20:16:37.000-08:00
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.

This problem exists from the beginning of git history.

Signed-off-by: David Ahern &lt;dsahern@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
@@ -350,6 +350,9 @@ static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
 					err = -EINVAL;
 					goto out_unlock;
 				}
+			}
+
+			if (sk->sk_bound_dev_if) {
 				dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
 				if (!dev) {
 					err = -ENODEV;
