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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no 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 CF3C9C33C9E for ; Fri, 17 Jan 2020 04:44:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C7452072E for ; Fri, 17 Jan 2020 04:44:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="ZC2DR7zH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730151AbgAQEo4 (ORCPT ); Thu, 16 Jan 2020 23:44:56 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:35594 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726370AbgAQEo4 (ORCPT ); Thu, 16 Jan 2020 23:44:56 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 00H4cu8W123496; Fri, 17 Jan 2020 04:44:49 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-2019-08-05; bh=kei4/bh5MHiyU6Xb1JUCnPX298eNmKPXG3KGKMXdG2U=; b=ZC2DR7zHE/Z6E+kKSHYV3aSz6EfolElzN6YKOI3lzNNWoYFc68PweWCZP3oRkdx/PWs5 OZDL2668kyrUWwbwYlPjPgfHZEJH2URlqPu9I9DgNgyKEE0BQC2OdtwtNdF1ynOFzgq/ 4rbO+lthATkTFLpGdrHzmcZIWeewh8PEuinjRY/6kJK5tggZ7Wn493rwrbNfbyIoiM5s AzVbIZJleoS8BkcbraIAkLqlRO2EV8QmnsoL54gu+xB/odbZYFIv4yIzKYBusIWx1L5c JbaZmY9F5eZbQFmHDTtDLm5HALVxWOeo/2GxQf0gD+JWQjn8nTvnHH1XvkZt+TLfVnI0 vQ== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2130.oracle.com with ESMTP id 2xf74spexn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 17 Jan 2020 04:44:49 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 00H4d1Ss050604; Fri, 17 Jan 2020 04:44:48 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3030.oracle.com with ESMTP id 2xjxm85c5w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 17 Jan 2020 04:44:48 +0000 Received: from abhmp0003.oracle.com (abhmp0003.oracle.com [141.146.116.9]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 00H4il8S027494; Fri, 17 Jan 2020 04:44:47 GMT Received: from kadam (/129.205.23.165) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 16 Jan 2020 20:44:47 -0800 Date: Fri, 17 Jan 2020 07:46:30 +0300 From: Dan Carpenter To: Colin King Cc: Greg Kroah-Hartman , "Rafael J . Wysocki" , Simon Schwartz , kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH][next] driver core: platform: fix u32 greater or equal to zero comparison Message-ID: <20200117044629.GC19765@kadam> References: <20200116175758.88396-1-colin.king@canonical.com> <20200117044216.GC21151@kadam> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200117044216.GC21151@kadam> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9502 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=477 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001170035 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9502 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=537 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001170035 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 17, 2020 at 07:42:16AM +0300, Dan Carpenter wrote: > On Thu, Jan 16, 2020 at 05:57:58PM +0000, Colin King wrote: > > From: Colin Ian King > > > > Currently the check that a u32 variable i is >= 0 is always true because > > the unsigned variable will never be negative, causing the loop to run > > forever. Fix this by changing the pre-decrement check to a zero check on > > i followed by a decrement of i. > > > > Addresses-Coverity: ("Unsigned compared against 0") > > Fixes: 39cc539f90d0 ("driver core: platform: Prevent resouce overflow from causing infinite loops") > > A better fix would be to revert this patch. It doesn't fix a real bug. > The ->num_resources is typically under 5. It's not going to overflow > INT_MAX any time soon. There are "architectures with smaller ints." I left out a word. There are *no* "architectures with smaller ints."... I mean there used to be systems with 16 bit int but that was before I was born. You could never run linux on them. regards, dan carpenter