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=-12.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D28B4C433E2 for ; Wed, 16 Sep 2020 06:22:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9915D2067C for ; Wed, 16 Sep 2020 06:22:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600237327; bh=uJRg3V5jemoM77QzifyzTeMiwLxju00kO9REccN1WMY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=D5cWL517wafp7xitPe/qO0Gm4XJCYN5e+8bWitYZPii0XXyICHySRlXQj7OsELAwB 8P7HR4TWClRuLkJhkBFlBfdTcxNXiDHhMHlwJ9VhPhZllhxH4FdorKSxLUgNSlbVKH j9+TJHOh8EGZ+cKxejWkodXudsqSr3h99RzCIOjk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726533AbgIPGWE (ORCPT ); Wed, 16 Sep 2020 02:22:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:44604 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726510AbgIPGVx (ORCPT ); Wed, 16 Sep 2020 02:21:53 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1419A2067C; Wed, 16 Sep 2020 06:21:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600237312; bh=uJRg3V5jemoM77QzifyzTeMiwLxju00kO9REccN1WMY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DujFdqAhT1OQ3IRITXYlfsxdYOZL2VkULfVuEtbvzYXPW/m7rri6WMT2RUJjzFf6b eTQtttNQmPq5MX9cyCYupPwWkn9T5Q1EBSBt/mh82kezqtg+pW35+r9TK/Egnxy1F3 x/tXW4WOzOHx+Yx7GuP8z3svgmc6aeMtJvg315zo= Date: Wed, 16 Sep 2020 08:22:27 +0200 From: Greg KH 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] rtl8150: set memory to all 0xFFs on failed register reads Message-ID: <20200916062227.GD142621@kroah.com> References: <20200916050540.15290-1-anant.thazhemadam@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200916050540.15290-1-anant.thazhemadam@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Sep 16, 2020 at 10:35:40AM +0530, Anant Thazhemadam wrote: > get_registers() copies whatever memory is written by the > usb_control_msg() call even if the underlying urb call ends up failing. > > If get_registers() fails, or ends up reading 0 bytes, meaningless and > junk register values would end up being copied over (and eventually read > by the driver), and since most of the callers of get_registers() don't > check the return values of get_registers() either, this would go unnoticed. > > It might be a better idea to try and mirror the PCI master abort > termination and set memory to 0xFFs instead in such cases. It would be better to use this new api call instead of usb_control_msg(): https://lore.kernel.org/r/20200914153756.3412156-1-gregkh@linuxfoundation.org How about porting this patch to run on top of that series instead? That should make this logic much simpler. > > Fixes: https://syzkaller.appspot.com/bug?extid=abbc768b560c84d92fd3 > Reported-by: syzbot+abbc768b560c84d92fd3@syzkaller.appspotmail.com > Tested-by: syzbot+abbc768b560c84d92fd3@syzkaller.appspotmail.com > Signed-off-by: Anant Thazhemadam > --- > drivers/net/usb/rtl8150.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c > index 733f120c852b..04fca7bfcbcb 100644 > --- a/drivers/net/usb/rtl8150.c > +++ b/drivers/net/usb/rtl8150.c > @@ -162,8 +162,13 @@ static int get_registers(rtl8150_t * dev, u16 indx, u16 size, void *data) > ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0), > RTL8150_REQ_GET_REGS, RTL8150_REQT_READ, > indx, 0, buf, size, 500); > - if (ret > 0 && ret <= size) > + > + if (ret < 0) > + memset(data, 0xff, size); > + > + else > memcpy(data, buf, ret); > + > kfree(buf); > return ret; > } > @@ -276,7 +281,7 @@ static int write_mii_word(rtl8150_t * dev, u8 phy, __u8 indx, u16 reg) > > static inline void set_ethernet_addr(rtl8150_t * dev) > { > - u8 node_id[6]; > + u8 node_id[6] = {0}; This should not be needed to be done. thanks, greg k-h