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 3B568C433F5 for ; Sat, 4 Dec 2021 21:49:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355822AbhLDVws (ORCPT ); Sat, 4 Dec 2021 16:52:48 -0500 Received: from mail.mutex.one ([62.77.152.124]:33710 "EHLO mail.mutex.one" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231646AbhLDVwr (ORCPT ); Sat, 4 Dec 2021 16:52:47 -0500 Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.mutex.one (Postfix) with ESMTP id F3E0A16C27F2; Sat, 4 Dec 2021 23:49:16 +0200 (EET) X-Virus-Scanned: Debian amavisd-new at mail.mutex.one Received: from mail.mutex.one ([127.0.0.1]) by localhost (mail.mutex.one [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id eMoWQPvIqDML; Sat, 4 Dec 2021 23:49:16 +0200 (EET) Received: [127.0.0.1] (localhost [127.0.0.1])nknown [109.103.89.101]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.mutex.one (Postfix) with ESMTPSA id 9D94F16C08F2; Sat, 4 Dec 2021 23:49:15 +0200 (EET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mutex.one; s=default; t=1638654556; bh=EVhTg8nYuNCbP3r7ALG6+8NWgoFsT6iIYwfUXSTMBzA=; h=From:To:Cc:Subject:Date:From; b=Mz7Lx+o60D1QKd4Ke8Rslyqwui25ukjc13FPs/g2VZZuVW/0ZycSp+s908bnzbcG3 On7euWIxjhLt+/shYmapUmW1J8uHvRTmJxkPEs01vyFuitg3uER8hY/0WNUZ6b7Y6F BbFlkF3cwoP7b3pgsbncHABJbTyQnpKg/BcLB/aE= From: Marian Postevca To: Greg Kroah-Hartman , Felipe Balbi Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, Marian Postevca , stable@vger.kernel.org Subject: [PATCH v2] usb: gadget: u_ether: fix race in setting MAC address in setup phase Date: Sat, 4 Dec 2021 23:49:12 +0200 Message-Id: <20211204214912.17627-1-posteuca@mutex.one> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(). Signed-off-by: Marian Postevca Fixes: bcd4a1c40bee885e ("usb: gadget: u_ether: construct with default values and add setters/getters") Cc: stable@vger.kernel.org --- v2: Added Fixes and Cc tags to commit message. drivers/usb/gadget/function/u_ether.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index e0ad5aed6ac9..6f5d45ef2e39 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -17,6 +17,7 @@ #include #include #include +#include #include "u_ether.h" @@ -863,19 +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; + + net->addr_assign_type = NET_ADDR_RANDOM; + eth_hw_addr_set(net, dev->dev_mac); + 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" @@ -883,15 +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, 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; } -- 2.32.0