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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C2E1C433DF for ; Mon, 12 Oct 2020 19:11:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46E69214DB for ; Mon, 12 Oct 2020 19:11:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391219AbgJLTLX (ORCPT ); Mon, 12 Oct 2020 15:11:23 -0400 Received: from smtprelay0133.hostedemail.com ([216.40.44.133]:37514 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388013AbgJLTLX (ORCPT ); Mon, 12 Oct 2020 15:11:23 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay01.hostedemail.com (Postfix) with ESMTP id E3DE9100E7B44; Mon, 12 Oct 2020 19:11:20 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: lamp55_0c0ae3f271fc X-Filterd-Recvd-Size: 2942 Received: from XPS-9350.home (unknown [47.151.133.149]) (Authenticated sender: joe@perches.com) by omf03.hostedemail.com (Postfix) with ESMTPA; Mon, 12 Oct 2020 19:11:19 +0000 (UTC) Message-ID: Subject: Re: [PATCH AUTOSEL 5.8 18/24] net: usb: rtl8150: set random MAC address when set_ethernet_addr() fails From: Joe Perches To: Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Anant Thazhemadam , syzbot+abbc768b560c84d92fd3@syzkaller.appspotmail.com, Petko Manolov , "David S . Miller" , linux-usb@vger.kernel.org, netdev@vger.kernel.org Date: Mon, 12 Oct 2020 12:11:18 -0700 In-Reply-To: <20201012190239.3279198-18-sashal@kernel.org> References: <20201012190239.3279198-1-sashal@kernel.org> <20201012190239.3279198-18-sashal@kernel.org> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.36.4-0ubuntu1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2020-10-12 at 15:02 -0400, Sasha Levin wrote: > From: Anant Thazhemadam > > [ Upstream commit f45a4248ea4cc13ed50618ff066849f9587226b2 ] > > When get_registers() fails in set_ethernet_addr(),the uninitialized > value of node_id gets copied over as the address. > So, check the return value of get_registers(). > > If get_registers() executed successfully (i.e., it returns > sizeof(node_id)), copy over the MAC address using ether_addr_copy() > (instead of using memcpy()). > > Else, if get_registers() failed instead, a randomly generated MAC > address is set as the MAC address instead. This autosel is premature. This patch always sets a random MAC. See the follow on patch: https://lkml.org/lkml/2020/10/11/131 To my knowledge, this follow-ob has yet to be applied: > diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c [] > @@ -274,12 +274,20 @@ static int write_mii_word(rtl8150_t * dev, u8 phy, __u8 indx, u16 reg) > return 1; > } > > -static inline void set_ethernet_addr(rtl8150_t * dev) > +static void set_ethernet_addr(rtl8150_t *dev) > { > - u8 node_id[6]; > + u8 node_id[ETH_ALEN]; > + int ret; > + > + ret = get_registers(dev, IDR, sizeof(node_id), node_id); > > - get_registers(dev, IDR, sizeof(node_id), node_id); > - memcpy(dev->netdev->dev_addr, node_id, sizeof(node_id)); > + if (ret == sizeof(node_id)) { So this needs to use if (!ret) { or if (ret < 0) and reversed code blocks > + ether_addr_copy(dev->netdev->dev_addr, node_id); > + } else { > + eth_hw_addr_random(dev->netdev); > + netdev_notice(dev->netdev, "Assigned a random MAC address: %pM\n", > + dev->netdev->dev_addr); > + } > } > > static int rtl8150_set_mac_address(struct net_device *netdev, void *p)