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=-9.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 383F2C4727F for ; Tue, 29 Sep 2020 08:47:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA9302067D for ; Tue, 29 Sep 2020 08:47:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=konsulko.com header.i=@konsulko.com header.b="tO+PmyVt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727718AbgI2Ir4 (ORCPT ); Tue, 29 Sep 2020 04:47:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39890 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726064AbgI2Ir4 (ORCPT ); Tue, 29 Sep 2020 04:47:56 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 00B13C061755 for ; Tue, 29 Sep 2020 01:47:55 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id y15so3924019wmi.0 for ; Tue, 29 Sep 2020 01:47:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=konsulko.com; s=google; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-disposition:in-reply-to; bh=04NOm1CcnqBFH1lFELuJnkJP2M/KCWXwaUl0Wh9OcUc=; b=tO+PmyVtTbztmBizvLgCmAX4QG5q377A4oSC57bt1amxOb796KuKCoWdTtewoRDcFF xrlMO6QZd6X8lLgT5lrb5eFLu/Ra6uCxW7NKQyYNS/LmWwu5V1WgG32EXm6FaXx+7TAo 7X1w7o6HRAWI6ZE9lvKdfCledlYDRck0hynQE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :in-reply-to; bh=04NOm1CcnqBFH1lFELuJnkJP2M/KCWXwaUl0Wh9OcUc=; b=jpHeumt1w2evG7OJ+Df40JDImLLsP61b015kDM82n1sroBWP/SFHQLTUrr7dwcKna+ O+Vi6/3sjJYTCCP3IKxh6+hC3rcvn4ByUxOphjHTW5fFSbycMTV+hXPZoq88ReDsnlq2 2kOF7x7b89zPFwBZa68hGyJUxnR5TZfHoQo+b4jEUJcMDqHH3yYw3Th3jQEuYD58EbUS ypm752LGXEWKgzXIHALm3tTz/R98iZOWd9T1X1k0ECuCYY4LOlnswTHpOSvucH+/gbhm 9wFm+/0h06C75nGfehp5LQp9tv/OCZYB3uO3jL/Gr5KZnaG2TF4y2LkRnL+CFClWtamQ T6eQ== X-Gm-Message-State: AOAM533pD+YMksHHRbPiTe5gwywFq0UMTzgFW6au3ktrBJuNYYRyyNFe COupA6tBwwWZgKM48AYYWilbBw== X-Google-Smtp-Source: ABdhPJzCaYhOmzZGYjtY3NFO+dcWZjeq7anc17VA56qyI4ndCuaOwSJMJVZxvCxDqgu253DyYg8FFg== X-Received: by 2002:a1c:f612:: with SMTP id w18mr3235574wmc.47.1601369274642; Tue, 29 Sep 2020 01:47:54 -0700 (PDT) Received: from carbon ([94.26.108.4]) by smtp.gmail.com with ESMTPSA id m3sm5155328wrs.83.2020.09.29.01.47.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Sep 2020 01:47:54 -0700 (PDT) Date: Tue, 29 Sep 2020 11:47:52 +0300 From: Petko Manolov To: Anant Thazhemadam Cc: 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 Subject: Re: [Linux-kernel-mentees][PATCH] net: usb: rtl8150: prevent set_ethernet_addr from setting uninit address Message-ID: <20200929084752.GA8101@carbon> Mail-Followup-To: Anant Thazhemadam , 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200929082028.50540-1-anant.thazhemadam@gmail.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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