net: usb: usbnet: fix name regression

[ Upstream commit 8a7d12d674ac6f2147c18f36d1e15f1a48060edf ]

The fix for MAC addresses broke detection of the naming convention
because it gave network devices no random MAC before bind()
was called. This means that the check for the local assignment bit
was always negative as the address was zeroed from allocation,
instead of from overwriting the MAC with a unique hardware address.

The correct check for whether bind() has altered the MAC is
done with is_zero_ether_addr

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reported-by: Greg Thelen <gthelen@google.com>
Diagnosed-by: John Sperbeck <jsperbeck@google.com>
Fixes: bab8eb0dd4cb9 ("usbnet: modern method to get random MAC")
Link: https://patch.msgid.link/20241017071849.389636-1-oneukum@suse.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 2945e336505bf88c36b0b5af9b96d5479f761dc8..f66975c452aa1bdf713e1d30342c8d723c8078ee 100644 (file)
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1769,7 +1769,8 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
                // can rename the link if it knows better.
                if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
                    ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
-                    (net->dev_addr [0] & 0x02) == 0))
+                    /* somebody touched it*/
+                    !is_zero_ether_addr(net->dev_addr)))
                        strscpy(net->name, "eth%d", sizeof(net->name));
                /* WLAN devices should always be named "wlan%d" */
                if ((dev->driver_info->flags & FLAG_WLAN) != 0)