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 85B67C433F5 for ; Mon, 27 Dec 2021 15:43:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238912AbhL0PnY (ORCPT ); Mon, 27 Dec 2021 10:43:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239867AbhL0Pkg (ORCPT ); Mon, 27 Dec 2021 10:40:36 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15457C0698CE; Mon, 27 Dec 2021 07:39:12 -0800 (PST) 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 6CAADCE1070; Mon, 27 Dec 2021 15:39:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FA8DC36AEA; Mon, 27 Dec 2021 15:39:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640619548; bh=t4jF6f4pwDtncnt8dOYqf1JCg2PCk199oTUJyuwiLXQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WV+noB+GouLAtUz4iRZULcon/1IA9OnkZhuSPO1sbauixrmgZvL0sUMKvQgec7L6L nn/5WXpTsbW+8ZJPAkVwiLt/6lr3OVLgN1eIesYHF+N/p/CtxmV4O11eEiItGwDuQj 4GJt8lKTXYOEdy4WE7YqvH4+mAgSfnxLdGpnXgv0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marian Postevca Subject: [PATCH 5.10 62/76] usb: gadget: u_ether: fix race in setting MAC address in setup phase Date: Mon, 27 Dec 2021 16:31:17 +0100 Message-Id: <20211227151326.844271951@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211227151324.694661623@linuxfoundation.org> References: <20211227151324.694661623@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marian Postevca 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(). Fixes: bcd4a1c40bee885e ("usb: gadget: u_ether: construct with default values and add setters/getters") Cc: stable@vger.kernel.org Signed-off-by: Marian Postevca Link: https://lore.kernel.org/r/20211204214912.17627-1-posteuca@mutex.one Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/u_ether.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -860,19 +860,23 @@ int gether_register_netdev(struct net_de { 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" @@ -880,15 +884,6 @@ int gether_register_netdev(struct net_de */ 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, NULL); - 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; }