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 617ACCA9EB6 for ; Wed, 23 Oct 2019 13:06:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2E9D421872 for ; Wed, 23 Oct 2019 13:06:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="WI8R13my" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390775AbfJWNGk (ORCPT ); Wed, 23 Oct 2019 09:06:40 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:40350 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390642AbfJWNGk (ORCPT ); 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Wed, 23 Oct 2019 13:06:38 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3030.oracle.com with ESMTP id 2vtjkfqqyy-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 23 Oct 2019 13:06:38 +0000 Received: from abhmp0004.oracle.com (abhmp0004.oracle.com [141.146.116.10]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x9ND6aql028538; Wed, 23 Oct 2019 13:06:37 GMT Received: from mwanda (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 23 Oct 2019 06:06:36 -0700 Date: Wed, 23 Oct 2019 16:06:24 +0300 From: Dan Carpenter To: ajay.joshi@wdc.com Cc: linux-block@vger.kernel.org Subject: [bug report] null_blk: return fixed zoned reads > write pointer Message-ID: <20191023130623.GA3196@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9418 signatures=668684 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 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-1910230134 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9418 signatures=668684 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=1 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-1910230134 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hello Ajay Joshi, The patch dd85b4922de1: "null_blk: return fixed zoned reads > write pointer" from Oct 17, 2019, leads to the following static checker warning: drivers/block/null_blk_zoned.c:91 null_zone_valid_read_len() warn: uncapped user index 'dev->zones[null_zone_no(dev, sector)]' drivers/block/null_blk_zoned.c 87 size_t null_zone_valid_read_len(struct nullb *nullb, 88 sector_t sector, unsigned int len) 89 { 90 struct nullb_device *dev = nullb->dev; 91 struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)]; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 92 unsigned int nr_sectors = len >> SECTOR_SHIFT; 93 94 /* Read must be below the write pointer position */ 95 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL || ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 96 sector + nr_sectors <= zone->wp) 97 return len; 98 99 if (sector > zone->wp) ^^^^^^^^^^^^^^^^^ Smatch complains about "sector" being from the untrusted all the time and I kind of just ignore it these days. But here it looks like we're checking "sector" after we already used it so that seems very suspicious. It feels like "sector > zone->wp" should come at the very start of the function. 100 return 0; 101 102 return (zone->wp - sector) << SECTOR_SHIFT; 103 } regards, dan carpenter