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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,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 56E1EC433DF for ; Sun, 11 Oct 2020 19:31:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1EB252145D for ; Sun, 11 Oct 2020 19:31:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=nucleusys.com header.i=@nucleusys.com header.b="nPqyL0SK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728833AbgJKTbi (ORCPT ); Sun, 11 Oct 2020 15:31:38 -0400 Received: from lan.nucleusys.com ([92.247.61.126]:36238 "EHLO zztop.nucleusys.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726333AbgJKTbi (ORCPT ); Sun, 11 Oct 2020 15:31:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=nucleusys.com; s=x; h=In-Reply-To:Content-Type:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=lfk8Bx8ZAaoT2rdzuE84wdKCTPTT1fgZZGAXDO2auPE=; b=nPqyL0SK9P/XrtyKOaMoUKTbsZ xRYgVjG8lNxwEy1FVQuILLK6LVFkNT/94RWWgrAA/k77UvxU3yrKlBY9HOozL6Qf5vZF6+nFO0Pce KyKp6tbXGyNRzOl/OpmTfvS/Bw+c79ZjIMEqJyenZ8b5RTfuh1hNzw75fV1Cxn1Da/pU=; Received: from 78-83-68-78.spectrumnet.bg ([78.83.68.78] helo=p310) by zztop.nucleusys.com with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kRh3v-0007ru-He; Sun, 11 Oct 2020 22:31:19 +0300 Date: Sun, 11 Oct 2020 22:31:19 +0300 From: Petko Manolov To: Joe Perches Cc: Jakub Kicinski , Anant Thazhemadam , davem@davemloft.net, linux-usb@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-next@vger.kernel.org, sfr@canb.auug.org.au Subject: Re: [PATCH v2] net: usb: rtl8150: don't incorrectly assign random MAC addresses Message-ID: <20201011193119.GA4061@p310> References: <20201010064459.6563-1-anant.thazhemadam@gmail.com> <20201011173030.141582-1-anant.thazhemadam@gmail.com> <20201011105934.5c988cd3@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <6307397bd43636fea2e7341d24417cbbc3aaf922.camel@perches.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6307397bd43636fea2e7341d24417cbbc3aaf922.camel@perches.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On 20-10-11 11:33:00, Joe Perches wrote: > On Sun, 2020-10-11 at 10:59 -0700, Jakub Kicinski wrote: > > On Sun, 11 Oct 2020 23:00:30 +0530 Anant Thazhemadam wrote: > > > In set_ethernet_addr(), if get_registers() succeeds, the ethernet address > > > that was read must be copied over. Otherwise, a random ethernet address > > > must be assigned. > > > > > > get_registers() returns 0 if successful, and negative error number > > > otherwise. However, in set_ethernet_addr(), this return value is > > > incorrectly checked. > > > > > > Since this return value will never be equal to sizeof(node_id), a > > > random MAC address will always be generated and assigned to the > > > device; even in cases when get_registers() is successful. > > > > > > Correctly modifying the condition that checks if get_registers() was > > > successful or not fixes this problem, and copies the ethernet address > > > appropriately. > > There are many unchecked uses of set_registers and get_registers > in this file. > > If failures are really expected, then it might be better to fix > them up too. Checking the return value of each get/set_registers() is going to be a PITA and not very helpful. Doing so when setting the MAC address _does_ make sense as in that case it is not a hard error. In almost all other occasions if usb_control_msg_send/recv() return an error i'd rather dump an error message (from within get/set_registers()) and let the user decide whether to get rid of this adapter or start debugging it. cheers, Petko > $ git grep -w '[gs]et_registers' drivers/net/usb/rtl8150.c > drivers/net/usb/rtl8150.c:static int get_registers(rtl8150_t * dev, u16 indx, u16 size, void *data) > drivers/net/usb/rtl8150.c:static int set_registers(rtl8150_t * dev, u16 indx, u16 size, const void *data) > drivers/net/usb/rtl8150.c: set_registers(dev, PHYADD, sizeof(data), data); > drivers/net/usb/rtl8150.c: set_registers(dev, PHYCNT, 1, &tmp); > drivers/net/usb/rtl8150.c: get_registers(dev, PHYCNT, 1, data); > drivers/net/usb/rtl8150.c: get_registers(dev, PHYDAT, 2, data); > drivers/net/usb/rtl8150.c: set_registers(dev, PHYADD, sizeof(data), data); > drivers/net/usb/rtl8150.c: set_registers(dev, PHYCNT, 1, &tmp); > drivers/net/usb/rtl8150.c: get_registers(dev, PHYCNT, 1, data); > drivers/net/usb/rtl8150.c: ret = get_registers(dev, IDR, sizeof(node_id), node_id); > drivers/net/usb/rtl8150.c: set_registers(dev, IDR, netdev->addr_len, netdev->dev_addr); > drivers/net/usb/rtl8150.c: get_registers(dev, CR, 1, &cr); > drivers/net/usb/rtl8150.c: set_registers(dev, CR, 1, &cr); > drivers/net/usb/rtl8150.c: set_registers(dev, IDR_EEPROM + (i * 2), 2, > drivers/net/usb/rtl8150.c: set_registers(dev, CR, 1, &cr); > drivers/net/usb/rtl8150.c: set_registers(dev, CR, 1, &data); > drivers/net/usb/rtl8150.c: get_registers(dev, CR, 1, &data); > drivers/net/usb/rtl8150.c: set_registers(dev, RCR, 1, &rcr); > drivers/net/usb/rtl8150.c: set_registers(dev, TCR, 1, &tcr); > drivers/net/usb/rtl8150.c: set_registers(dev, CR, 1, &cr); > drivers/net/usb/rtl8150.c: get_registers(dev, MSR, 1, &msr); > drivers/net/usb/rtl8150.c: get_registers(dev, CR, 1, &cr); > drivers/net/usb/rtl8150.c: set_registers(dev, CR, 1, &cr); > drivers/net/usb/rtl8150.c: get_registers(dev, CSCR, 2, &tmp); > drivers/net/usb/rtl8150.c: set_registers(dev, IDR, 6, netdev->dev_addr); > drivers/net/usb/rtl8150.c: get_registers(dev, BMCR, 2, &bmcr); > drivers/net/usb/rtl8150.c: get_registers(dev, ANLP, 2, &lpa); > > >