2018-11-27, 14:05:42 +0100, Alexis Bauvin wrote:
> diff --git a/net/ipv4/udp_tunnel.c b/net/ipv4/udp_tunnel.c
> index 6539ff15e9a3..dc68e15a4f72 100644
> --- a/net/ipv4/udp_tunnel.c
> +++ b/net/ipv4/udp_tunnel.c
> @@ -20,6 +20,16 @@ int udp_sock_create4(struct net *net, struct udp_port_cfg
> *cfg,
> if (err < 0)
> goto error;
>
> + if (cfg->bind_ifindex) {
> + struct net_device *dev;
> +
> + dev = __dev_get_by_index(net, cfg->bind_ifindex);
Quoting from net/core/dev.c:
* [...] The device has not
* had its reference counter increased so the caller must be careful
* about locking. The caller must hold either the RTNL semaphore
* or @dev_base_lock.
*/
which is the case for VXLAN (and GENEVE) during ndo_open, but I don't
think other UDP tunnels (FOU, L2TP) are holding RTNL when they call
udp_sock_create(). dev_get_by_index() + dev_put() should be safe.
Also, I don't think it's a problem with vxlan, but this could handle
the case where __dev_get_by_index returns NULL.
> + err = kernel_setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE,
> + dev->name, strlen(dev->name) + 1);
> + if (err < 0)
> + goto error;
> + }
> +
> udp_addr.sin_family = AF_INET;
> udp_addr.sin_addr = cfg->local_ip;
> udp_addr.sin_port = cfg->local_udp_port;
--
Sabrina
