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=-11.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 65C39C4727F for ; Wed, 30 Sep 2020 04:02:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 105D7208D5 for ; Wed, 30 Sep 2020 04:02:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FOUG2k8+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725790AbgI3ECW (ORCPT ); Wed, 30 Sep 2020 00:02:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49432 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725306AbgI3ECV (ORCPT ); Wed, 30 Sep 2020 00:02:21 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D82FFC061755; Tue, 29 Sep 2020 21:02:21 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id x16so277301pgj.3; Tue, 29 Sep 2020 21:02:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-transfer-encoding:content-language; bh=A6Iu8CK+fvMEAi5WAmBNnIyxewSXT0brLKenSVEGXL4=; b=FOUG2k8+MaztgIzts4HwDlrGsCudjd56IKZWBLbgBRGW/+cSpuwEsCSWMlu5X5nBBu 8v6RNE3ofy5cTam6TcIjkuItXIvPyc7BnaDjbojyP6bpWtePhAM6lThFjdqzXAhLVzGv rJbQKjncIrbIlyRWHDJ29BFUMMRVe0Y5VsBPbLsl3Bst+P8Ktaa043qBw5dyOe+/kXhe UYwVUTDrG5ZOP70fROR05CZtKDJ9zhOZyHz1hblG2GGXhyuRq1b96FSREuL9ukVIUWXe 18YjjTXSkaJR3uRKRYnMtw/wPv5ezudgB2hkwL7x8DllO4HhtpI+cExOxnfKNgTAw4d1 a28Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=A6Iu8CK+fvMEAi5WAmBNnIyxewSXT0brLKenSVEGXL4=; b=VcRc6mu+7brWc75q6ILlvYGzEL6KabQ23PT5qCQEAUJ26350zKIcCrIa9ueDPpQl7g tmauz128WqxRYuV0/aJSrrs03p+GWwlUrLn34I3Q4/mKCh7dMapxTNeGAaD5LHKbO9R8 BdGwSp8Mq+z4wrccAaXtIvIZnHX8YBYi7y3qqrAKN3NeoZc3QkALRfZESJFG3Wj3kaql gSiKk7QOXWogOwuXeBkvq5oBvKVwClUsYV6V0YoQEohOGkLD2uNd9SdTcq1A8RMjShMG 5suLpl9qAgM+7SRmLg10aAlvHqU+0UX1wYr5OoAV0PEEURvumOeeTrR9AGeOMfRrabc2 y94A== X-Gm-Message-State: AOAM5331xaOuVIzMSKRR4G7p4gGVGfROG5u3spkiwnjHBM2RJ0eB6eLQ Nt71zBF5XpISpvpn6TzuX0wxGR7licyYlqdzwoQ= X-Google-Smtp-Source: ABdhPJyA5nA4I3XO3XKaf/fb/M89xL8cx8S1ztqnn2lD6/kSbg6onBEyGX/DZDqqLsywchH+AQJnXQ== X-Received: by 2002:a63:a51a:: with SMTP id n26mr624314pgf.1.1601438540777; Tue, 29 Sep 2020 21:02:20 -0700 (PDT) Received: from [192.168.0.104] ([49.207.218.220]) by smtp.gmail.com with ESMTPSA id f19sm354554pfd.45.2020.09.29.21.02.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 29 Sep 2020 21:02:19 -0700 (PDT) Subject: Re: [Linux-kernel-mentees][PATCH] net: usb: rtl8150: prevent set_ethernet_addr from setting uninit address To: linux-kernel-mentees@lists.linuxfoundation.org, syzbot+abbc768b560c84d92fd3@syzkaller.appspotmail.com, Petko Manolov , "David S. Miller" , Jakub Kicinski , linux-usb@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20200929082028.50540-1-anant.thazhemadam@gmail.com> <20200929084752.GA8101@carbon> From: Anant Thazhemadam Message-ID: Date: Wed, 30 Sep 2020 09:32:15 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200929084752.GA8101@carbon> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On 29/09/20 2:17 pm, Petko Manolov wrote: > On 20-09-29 13:50:28, Anant Thazhemadam wrote: >> When get_registers() fails (which happens when usb_control_msg() fails) >> in set_ethernet_addr(), the uninitialized value of node_id gets copied >> as the address. >> >> Checking for the return values appropriately, and handling the case >> wherein set_ethernet_addr() fails like this, helps in avoiding the >> mac address being incorrectly set in this manner. >> >> Reported-by: syzbot+abbc768b560c84d92fd3@syzkaller.appspotmail.com >> Tested-by: syzbot+abbc768b560c84d92fd3@syzkaller.appspotmail.com >> Signed-off-by: Anant Thazhemadam >> --- >> drivers/net/usb/rtl8150.c | 24 ++++++++++++++++-------- >> 1 file changed, 16 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c >> index 733f120c852b..e542a9ab2ff8 100644 >> --- a/drivers/net/usb/rtl8150.c >> +++ b/drivers/net/usb/rtl8150.c >> @@ -150,7 +150,7 @@ static const char driver_name [] = "rtl8150"; >> ** device related part of the code >> ** >> */ >> -static int get_registers(rtl8150_t * dev, u16 indx, u16 size, void *data) >> +static int get_registers(rtl8150_t *dev, u16 indx, u16 size, void *data) >> { >> void *buf; >> int ret; >> @@ -274,12 +274,17 @@ 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 bool set_ethernet_addr(rtl8150_t *dev) >> { >> u8 node_id[6]; >> + int ret; >> >> - get_registers(dev, IDR, sizeof(node_id), node_id); >> - memcpy(dev->netdev->dev_addr, node_id, sizeof(node_id)); >> + ret = get_registers(dev, IDR, sizeof(node_id), node_id); >> + if (ret > 0 && ret <= sizeof(node_id)) { > get_registers() was recently modified to use usb_control_msg_recv() which does > not return partial reads. IOW you'll either get negative value or > sizeof(node_id). Since it is good to be paranoid i'd convert the above check > to: > > if (ret == sizeof(node_id)) { > > and fail in any other case. Apart from this minor detail the rest of the patch > looks good to me. > > Acked-by: Petko Manolov Got it. I'll be sure to include this in a v2, and send that in soon enough. Thanks for pointing that out. :) Thanks, Anant