From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2AB2C43334 for ; Thu, 30 Jun 2022 03:50:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231612AbiF3DuT (ORCPT ); Wed, 29 Jun 2022 23:50:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45876 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229449AbiF3DuS (ORCPT ); Wed, 29 Jun 2022 23:50:18 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF9FF2FFD8; Wed, 29 Jun 2022 20:50:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 1D89BCE12CC; Thu, 30 Jun 2022 03:50:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A735C34115; Thu, 30 Jun 2022 03:50:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1656561014; bh=JPEafwGbkT01ZireQUy4if9aNorRS7SSTX6HGDu0NUU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=TumKcmgOxp/Weth9ScUf8HZhBO8Iqw8JUF2hdWw0AlKmgYUROK7VCr7y4lw65qWMA Tnmj2CW1vxOy7Gw7sHp7Vu4VCUV1l5mgLzLd+a3LtLoNdpIuKcMyhQXyRIWBucwc5F SP5WL36dfRbbeseRwMvuELLEihbITMLKUi33PciE/CB99HDg0zvoH5vux0OQPeAO/w ow8zBGfbKxJZzzBkdMFkpNlnZM+jPzrOlfWUJvl5hlJkg44hN3EMBv96DXYBS3GU6z mTV/yHoGxFhwpi8TyUZR3Ta/EWT0o5+owsSHFlnvQHR1p2IWUXnqwYhSOCrcDXHGis +9sRUD9PDm4OQ== Date: Wed, 29 Jun 2022 20:50:13 -0700 From: Jakub Kicinski To: Oliver Neukum Cc: davem@davemloft.net, netdev@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [PATCH] usbnet: use each random address only once Message-ID: <20220629205013.6a7db024@kernel.org> In-Reply-To: <20220629142149.1298-1-oneukum@suse.com> References: <20220629142149.1298-1-oneukum@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 29 Jun 2022 16:21:49 +0200 Oliver Neukum wrote: > Even random MACs should be unique to a device. > Get a new one each time it is used. > > This bug is as old as the driver. > > Signed-off-by: Oliver Neukum > --- > drivers/net/usb/usbnet.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c > index 02b915b1e142..a90aece93f4a 100644 > --- a/drivers/net/usb/usbnet.c > +++ b/drivers/net/usb/usbnet.c > @@ -1797,8 +1797,11 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod) > } > > /* let userspace know we have a random address */ > - if (ether_addr_equal(net->dev_addr, node_id)) > + if (ether_addr_equal(net->dev_addr, node_id)) { > net->addr_assign_type = NET_ADDR_RANDOM; > + /* next device needs a new one*/ > + eth_random_addr(node_id); > + } > > if ((dev->driver_info->flags & FLAG_WLAN) != 0) > SET_NETDEV_DEVTYPE(net, &wlan_type); Why is that node_id thing even there, can we just delete it? Leave the address as all-zero and check if driver filled it in with: if (!is_valid_ether_addr(net->dev_addr)) eth_hw_addr_random(net->dev_addr);