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=-10.1 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_PASS,UNPARSEABLE_RELAY,USER_AGENT_MUTT 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 A582FC43441 for ; Mon, 26 Nov 2018 09:48:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6C2992086B for ; Mon, 26 Nov 2018 09:48:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="3l2SdiMo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6C2992086B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726512AbeKZUle (ORCPT ); Mon, 26 Nov 2018 15:41:34 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:51860 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726280AbeKZUle (ORCPT ); Mon, 26 Nov 2018 15:41:34 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id wAQ9gwAq150245; Mon, 26 Nov 2018 09:47:56 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2018-07-02; bh=Fa5xW9Cxynbl4UAT5xsxSvfem6iGLOlMnOMw99xSS+A=; b=3l2SdiMorebgo9Vr8WCttLobCnlSqF/zd1HEmax1G21hQoiajbLxCHLTp7fAmoavmwdz gGV43XITJau5HDNN/PDCsPUbitVVlAzcNiwH5z2kLkNCRcg98jVm1JJdc+Gxv+y9qt9A IouBuCKaGoXi847RDHSr7OLhN2/Zr5CzRGCoTuhd7mcwietYsEmAxgb74/L55mE9tqCQ +f+8tZG3sjEHHs0G9+cfr0h2+xMr8FyfxYuvqeBFmd3ZHqw95o5FzEfBABVCVS7+ygss YUFXHh9Kh2KEuUOoGGicKAxIxC2smafhrCL4cmXeo67ZdJrrCRckpye3xvm0f1iBaNZV VQ== Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by userp2120.oracle.com with ESMTP id 2nxy9qvn6a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 26 Nov 2018 09:47:56 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id wAQ9ltgW028062 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 26 Nov 2018 09:47:56 GMT Received: from abhmp0002.oracle.com (abhmp0002.oracle.com [141.146.116.8]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id wAQ9lsG9000830; Mon, 26 Nov 2018 09:47:54 GMT Received: from unbuntlaptop (/41.202.241.51) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 26 Nov 2018 01:47:54 -0800 Date: Mon, 26 Nov 2018 12:47:45 +0300 From: Dan Carpenter To: Michael Straube Cc: gregkh@linuxfoundation.org, devel@driverdev.osuosl.org, linux@wolf-entwicklungen.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH] staging: pi433: fix potential null dereference Message-ID: <20181126094745.GF3088@unbuntlaptop> References: <20181125092225.10188-1-straube.linux@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181125092225.10188-1-straube.linux@gmail.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9088 signatures=668685 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=8.0.1-1810050000 definitions=main-1811260090 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Nov 25, 2018 at 10:22:25AM +0100, Michael Straube wrote: > Add a test for successful call to cdev_alloc() to avoid > potential null dereference. Issue reported by smatch. > Fixes: 874bcba65f9a ("staging: pi433: New driver") > Signed-off-by: Michael Straube > --- > drivers/staging/pi433/pi433_if.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/staging/pi433/pi433_if.c b/drivers/staging/pi433/pi433_if.c > index 786478671190..d72de2105053 100644 > --- a/drivers/staging/pi433/pi433_if.c > +++ b/drivers/staging/pi433/pi433_if.c > @@ -1245,6 +1245,10 @@ static int pi433_probe(struct spi_device *spi) > > /* create cdev */ > device->cdev = cdev_alloc(); > + if (!device->cdev) { > + dev_dbg(device->dev, "allocation of cdev failed"); > + goto cdev_failed; > + } > device->cdev->owner = THIS_MODULE; > cdev_init(device->cdev, &pi433_fops); > retval = cdev_add(device->cdev, device->devt, 1); There is a second related bug here if we cdev_add() fails then we should call cdev_del(device->cdev). (cdev_del() does not take a NULL cdev pointer). regards, dan carpenter