From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Fri, 11 Oct 2019 13:58:56 +0000 Subject: Re: [PATCH] USB: legousbtower: fix a signedness bug in tower_probe() Message-Id: <20191011135855.GE4774@kadam> List-Id: References: <20191011133525.GB22905@mwanda> <5DA088DE.5040902@bfs.de> In-Reply-To: <5DA088DE.5040902@bfs.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: walter harms Cc: Juergen Stuber , Johan Hovold , Greg Kroah-Hartman , legousb-devel@lists.sourceforge.net, linux-usb@vger.kernel.org, kernel-janitors@vger.kernel.org On Fri, Oct 11, 2019 at 03:51:26PM +0200, walter harms wrote: > > > Am 11.10.2019 15:35, schrieb Dan Carpenter: > > The problem is that sizeof() is unsigned long so negative error codes > > are type promoted to high positive values and the condition becomes > > false. > > > > Fixes: 1d427be4a39d ("USB: legousbtower: fix slab info leak at probe") > > Signed-off-by: Dan Carpenter > > --- > > drivers/usb/misc/legousbtower.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c > > index 9d4c52a7ebe0..835908fe1e65 100644 > > --- a/drivers/usb/misc/legousbtower.c > > +++ b/drivers/usb/misc/legousbtower.c > > @@ -881,7 +881,7 @@ static int tower_probe (struct usb_interface *interface, const struct usb_device > > get_version_reply, > > sizeof(*get_version_reply), > > 1000); > > - if (result < sizeof(*get_version_reply)) { > > + if (result < 0 || result < sizeof(*get_version_reply)) { > > if (result >= 0) > > result = -EIO; > > dev_err(idev, "get version request failed: %d\n", result); > > i am not an USB expert but it seems that this is a complicated way > to check for result != sizeof(*get_version_reply). Yeah. You're right. That would look nicer. I will resend. regards, dan carpenter 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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, USER_AGENT_SANE_1 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 AD91EC47404 for ; Fri, 11 Oct 2019 13:59:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8168820673 for ; Fri, 11 Oct 2019 13:59:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="RHtJ2w9G" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728151AbfJKN7d (ORCPT ); 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Fri, 11 Oct 2019 13:59:15 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x9BDvig5046591; Fri, 11 Oct 2019 13:59:15 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3020.oracle.com with ESMTP id 2vje2y2dys-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 11 Oct 2019 13:59:15 +0000 Received: from abhmp0016.oracle.com (abhmp0016.oracle.com [141.146.116.22]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x9BDxDuq000425; Fri, 11 Oct 2019 13:59:13 GMT Received: from kadam (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 11 Oct 2019 13:59:12 +0000 Date: Fri, 11 Oct 2019 16:58:56 +0300 From: Dan Carpenter To: walter harms Cc: Juergen Stuber , Johan Hovold , Greg Kroah-Hartman , legousb-devel@lists.sourceforge.net, linux-usb@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] USB: legousbtower: fix a signedness bug in tower_probe() Message-ID: <20191011135855.GE4774@kadam> References: <20191011133525.GB22905@mwanda> <5DA088DE.5040902@bfs.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5DA088DE.5040902@bfs.de> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9406 signatures=668684 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910110131 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9406 signatures=668684 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910110131 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Fri, Oct 11, 2019 at 03:51:26PM +0200, walter harms wrote: > > > Am 11.10.2019 15:35, schrieb Dan Carpenter: > > The problem is that sizeof() is unsigned long so negative error codes > > are type promoted to high positive values and the condition becomes > > false. > > > > Fixes: 1d427be4a39d ("USB: legousbtower: fix slab info leak at probe") > > Signed-off-by: Dan Carpenter > > --- > > drivers/usb/misc/legousbtower.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c > > index 9d4c52a7ebe0..835908fe1e65 100644 > > --- a/drivers/usb/misc/legousbtower.c > > +++ b/drivers/usb/misc/legousbtower.c > > @@ -881,7 +881,7 @@ static int tower_probe (struct usb_interface *interface, const struct usb_device > > get_version_reply, > > sizeof(*get_version_reply), > > 1000); > > - if (result < sizeof(*get_version_reply)) { > > + if (result < 0 || result < sizeof(*get_version_reply)) { > > if (result >= 0) > > result = -EIO; > > dev_err(idev, "get version request failed: %d\n", result); > > i am not an USB expert but it seems that this is a complicated way > to check for result != sizeof(*get_version_reply). Yeah. You're right. That would look nicer. I will resend. regards, dan carpenter