On Sat, Dec 25, 2021 at 08:46:01PM +0200, Marian Postevca wrote:
> commit 890d5b40908bfd1a79be018d2d297cf9df60f4ee upstream.
>
> When listening for notifications through netlink of a new interface being
> registered, sporadically, it is possible for the MAC to be read as zero.
> The zero MAC address lasts a short period of time and then switches to a
> valid random MAC address.
>
> This causes problems for netd in Android, which assumes that the interface
> is malfunctioning and will not use it.
>
> In the good case we get this log:
> InterfaceController::getCfg() ifName usb0
> hwAddr 92:a8:f0:73:79:5b ipv4Addr 0.0.0.0 flags 0x1002
>
> In the error case we get these logs:
> InterfaceController::getCfg() ifName usb0
> hwAddr 00:00:00:00:00:00 ipv4Addr 0.0.0.0 flags 0x1002
>
> netd : interfaceGetCfg("usb0")
> netd : interfaceSetCfg() -> ServiceSpecificException
> (99, "[Cannot assign requested address] : ioctl() failed")
>
> The reason for the issue is the order in which the interface is setup,
> it is first registered through register_netdev() and after the MAC
> address is set.
>
> Fixed by first setting the MAC address of the net_device and after that
> calling register_netdev().
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Marian Postevca <posteuca@xxxxxxxxx>
> Fixes: bcd4a1c40bee885e ("usb: gadget: u_ether: construct with default values and add setters/getters")
> ---
> drivers/usb/gadget/function/u_ether.c | 15 +++++----------
> 1 file changed, 5 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c
> index 38a35f57b22c0..f59c20457e658 100644
> --- a/drivers/usb/gadget/function/u_ether.c
> +++ b/drivers/usb/gadget/function/u_ether.c
> @@ -864,19 +864,23 @@ int gether_register_netdev(struct net_device *net)
> {
> struct eth_dev *dev;
> struct usb_gadget *g;
> - struct sockaddr sa;
> int status;
>
> if (!net->dev.parent)
> return -EINVAL;
> dev = netdev_priv(net);
> g = dev->gadget;
> +
> + memcpy(net->dev_addr, dev->dev_mac, ETH_ALEN);
> + net->addr_assign_type = NET_ADDR_RANDOM;
> +
> status = register_netdev(net);
> if (status < 0) {
> dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
> return status;
> } else {
> INFO(dev, "HOST MAC %pM\n", dev->host_mac);
> + INFO(dev, "MAC %pM\n", dev->dev_mac);
>
> /* two kinds of host-initiated state changes:
> * - iff DATA transfer is active, carrier is "on"
> @@ -884,15 +888,6 @@ int gether_register_netdev(struct net_device *net)
> */
> netif_carrier_off(net);
> }
> - sa.sa_family = net->type;
> - memcpy(sa.sa_data, dev->dev_mac, ETH_ALEN);
> - rtnl_lock();
> - status = dev_set_mac_address(net, &sa);
> - rtnl_unlock();
> - if (status)
> - pr_warn("cannot set self ethernet address: %d\n", status);
> - else
> - INFO(dev, "MAC %pM\n", dev->dev_mac);
>
> return status;
> }
> --
> 2.32.0
>
All now queued up, thanks.
greg k-h
