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 47612C0650F for ; Tue, 30 Jul 2019 14:41:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1E498206E0 for ; Tue, 30 Jul 2019 14:41:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="ZF9cgKZT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731512AbfG3Ole (ORCPT ); Tue, 30 Jul 2019 10:41:34 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:35456 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729908AbfG3Old (ORCPT ); Tue, 30 Jul 2019 10:41:33 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x6UEdMY9116600; Tue, 30 Jul 2019 14:41:25 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=cuzaUqVFKfxxZPrtZonQ6fI4cI9Il+2XFjdS69q+tWY=; b=ZF9cgKZTjiF4K1t1gX24TwYiZmDNrvK+GkJc4+W+KYmHsP+EkXGJ4XX6fILYt0hBJaBo 460RLDUj5dikrtkDucOLKdo5apn3AsDDD3B9jgutESX5v9qOXUql0hR4vnYt97z4vZLY SC2zn2CAAG8V+dTypLtL1yfs1/rSmRmtny9UmnRpUaKuUEN8OzFZMbRYo8m6x7i0//Xg qrgxK+bnHs4WL+sLZbkX6g0r8tvL048H4Y+jtxmIjSlaLXtgOq6fpQKEYq3dbf3aywRx 2befN7v5l/hi0NH1mc+wQ670USAh/fsUWnXO33VvxnTDs93+7eT6QEymymxENKOPsr4p +Q== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 2u0f8qxw1a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Jul 2019 14:41:25 +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 x6UEbv0B083346; Tue, 30 Jul 2019 14:41:24 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 2u0bqu75nj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Jul 2019 14:41:24 +0000 Received: from abhmp0009.oracle.com (abhmp0009.oracle.com [141.146.116.15]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x6UEfNOR030003; Tue, 30 Jul 2019 14:41:23 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 30 Jul 2019 07:41:22 -0700 Date: Tue, 30 Jul 2019 07:41:22 -0700 From: "Darrick J. Wong" To: Jia-Ju Bai Cc: bfoster@redhat.com, sandeen@sandeen.net, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] fs: xfs: Fix possible null-pointer dereferences in xchk_da_btree_block_check_sibling() Message-ID: <20190730144122.GP1561054@magnolia> References: <20190730023206.14587-1-baijiaju1990@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190730023206.14587-1-baijiaju1990@gmail.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9334 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=8.0.1-1906280000 definitions=main-1907300151 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9334 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=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1907300152 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 30, 2019 at 10:32:06AM +0800, Jia-Ju Bai wrote: > In xchk_da_btree_block_check_sibling(), there is an if statement on > line 274 to check whether ds->state->altpath.blk[level].bp is NULL: > if (ds->state->altpath.blk[level].bp) > > When ds->state->altpath.blk[level].bp is NULL, it is used on line 281: > xfs_trans_brelse(..., ds->state->altpath.blk[level].bp); > struct xfs_buf_log_item *bip = bp->b_log_item; > ASSERT(bp->b_transp == tp); > > Thus, possible null-pointer dereferences may occur. > > To fix these bugs, ds->state->altpath.blk[level].bp is checked before > being used. > > These bugs are found by a static analysis tool STCheck written by us. > > Signed-off-by: Jia-Ju Bai Looks ok, Reviewed-by: Darrick J. Wong --D > --- > v2: > * Adjust the code and add an assignment. > Thank Darrick J. Wong for helpful advice. > > --- > fs/xfs/scrub/dabtree.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/scrub/dabtree.c b/fs/xfs/scrub/dabtree.c > index 94c4f1de1922..77ff9f97bcda 100644 > --- a/fs/xfs/scrub/dabtree.c > +++ b/fs/xfs/scrub/dabtree.c > @@ -278,7 +278,11 @@ xchk_da_btree_block_check_sibling( > /* Compare upper level pointer to sibling pointer. */ > if (ds->state->altpath.blk[level].blkno != sibling) > xchk_da_set_corrupt(ds, level); > - xfs_trans_brelse(ds->dargs.trans, ds->state->altpath.blk[level].bp); > + if (ds->state->altpath.blk[level].bp) { > + xfs_trans_brelse(ds->dargs.trans, > + ds->state->altpath.blk[level].bp); > + ds->state->altpath.blk[level].bp = NULL; > + } > out: > return error; > } > -- > 2.17.0 >