commit b337af3a4d6147000b7ca6b3438bf5c820849b37 upstream.

In systemd systems setting a fixed MAC address through the "dev_addr" module argument fails systematically. When checking the MAC address after the interface is created it always has the same but different MAC address to the one supplied as argument.

This is partially caused by systemd which by default will set an internally generated permanent MAC address for interfaces that are marked as having a randomly generated address.

Commit 890d5b40908bfd1a ("usb: gadget: u_ether: fix race in setting MAC address in setup phase") didn't take into account the fact that the interface must be marked as having a set MAC address when it's set as module argument.

Fixed by marking the interface with NET_ADDR_SET when the "dev_addr" module argument is supplied.

Reported-by: Maximilian Senftleben kernel@mail.msdigital.de Cc: stable@vger.kernel.org Fixes: 890d5b40908bfd1a ("usb: gadget: u_ether: fix race in setting MAC address in setup phase") Signed-off-by: Marian Postevca posteuca@mutex.one --- drivers/usb/gadget/function/u_ether.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index d15a54f6c24b9..ef253599dcf96 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -774,9 +774,13 @@ struct eth_dev *gether_setup_name(struct usb_gadget *g, dev->qmult = qmult; snprintf(net->name, sizeof(net->name), "%s%%d", netname);

- if (get_ether_addr(dev_addr, net->dev_addr)) + if (get_ether_addr(dev_addr, net->dev_addr)) { + net->addr_assign_type = NET_ADDR_RANDOM; dev_warn(&g->dev, "using random %s ethernet address\n", "self"); + } else { + net->addr_assign_type = NET_ADDR_SET; + } if (get_ether_addr(host_addr, dev->host_mac)) dev_warn(&g->dev, "using random %s ethernet address\n", "host"); @@ -833,6 +837,9 @@ struct net_device *gether_setup_name_default(const char *netname) INIT_LIST_HEAD(&dev->tx_reqs); INIT_LIST_HEAD(&dev->rx_reqs);

+ /* by default we always have a random MAC address */ + net->addr_assign_type = NET_ADDR_RANDOM; + skb_queue_head_init(&dev->rx_frames);

/* network device setup */ @@ -869,7 +876,6 @@ int gether_register_netdev(struct net_device *net) dev = netdev_priv(net); g = dev->gadget;

- net->addr_assign_type = NET_ADDR_RANDOM; eth_hw_addr_set(net, dev->dev_mac);

status = register_netdev(net); @@ -910,6 +916,7 @@ int gether_set_dev_addr(struct net_device *net, const char *dev_addr) if (get_ether_addr(dev_addr, new_addr)) return -EINVAL; memcpy(dev->dev_mac, new_addr, ETH_ALEN); + net->addr_assign_type = NET_ADDR_SET; return 0; } EXPORT_SYMBOL_GPL(gether_set_dev_addr);