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 0E9DDC2BB55 for ; Thu, 16 Apr 2020 13:09:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1377214AF for ; Thu, 16 Apr 2020 13:09:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="kKM3XCkJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2894829AbgDPNJZ (ORCPT ); Thu, 16 Apr 2020 09:09:25 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:41712 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2894692AbgDPNJP (ORCPT ); Thu, 16 Apr 2020 09:09:15 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 03GD8Bhi030563; Thu, 16 Apr 2020 13:09:03 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-2020-01-29; bh=JVRFfnFS+OgWj7u5UNa3ISrw5T9J6EGkJSXP5AV0oP4=; b=kKM3XCkJV1xc4zUZKFip7MGr/drhgl31vuH/o+h5t35tdgm/gCgIaCAWFMs2H5nJEfrf 5Eq+H9EQuNAVqB7LKcUcqK5e37QC/1iIiYGsKKDA4NBfOnhoO+116xwjwIHU9UEFbLTT zY0z8Y425XQ4cJC2CpzsLuzafOBa49ie4JVWzzxmUixlNFQUHy9Vp/vtsOxHpL43RTQ+ 8Yz+lxUZ2q8bxADDxZslpeAsDjFJ8TrpKLcnlmOJry0MQZ2F8Gj9TI2E5l/Hc47IgJY/ J3fKyBgIw7DoBWzJN2JMeO7gA3gI7v774Tp9xsqLVkToKEQoGIJsHsKf6S1IkS/o61iW xg== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 30dn95s9mp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 Apr 2020 13:09:03 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 03GD7F8s117906; Thu, 16 Apr 2020 13:09:02 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 30emen0dbx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 Apr 2020 13:09:02 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 03GD8wWc001606; Thu, 16 Apr 2020 13:08:58 GMT Received: from kadam (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 16 Apr 2020 06:08:58 -0700 Date: Thu, 16 Apr 2020 16:08:47 +0300 From: Dan Carpenter To: Jason Gunthorpe Cc: Christophe JAILLET , selvin.xavier@broadcom.com, devesh.sharma@broadcom.com, dledford@redhat.com, leon@kernel.org, colin.king@canonical.com, roland@purestorage.com, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] RDMA/ocrdma: Fix an off-by-one issue in 'ocrdma_add_stat' Message-ID: <20200416130847.GP1163@kadam> References: <20200328073040.24429-1-christophe.jaillet@wanadoo.fr> <20200414183441.GA28870@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200414183441.GA28870@ziepe.ca> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9592 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxscore=0 suspectscore=0 mlxlogscore=999 phishscore=0 spamscore=0 bulkscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004160093 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9592 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 clxscore=1011 malwarescore=0 bulkscore=0 priorityscore=1501 lowpriorityscore=0 mlxscore=0 phishscore=0 spamscore=0 impostorscore=0 suspectscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004160093 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 14, 2020 at 03:34:41PM -0300, Jason Gunthorpe wrote: > The memcpy is still kind of silly right? What about this: > > static int ocrdma_add_stat(char *start, char *pcur, char *name, u64 count) > { > size_t len = (start + OCRDMA_MAX_DBGFS_MEM) - pcur; > int cpy_len; > > cpy_len = snprintf(pcur, len, "%s: %llu\n", name, count); > if (cpy_len >= len || cpy_len < 0) { The kernel version of snprintf() doesn't and will never return negatives. It would cause a huge security headache if it started returning negatives. > pr_err("%s: No space in stats buff\n", __func__); > return 0; > } regards, dan carpenter