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=-8.2 required=3.0 tests=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 9C786C433FF for ; Mon, 5 Aug 2019 02:39:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 76DCF20B1F for ; Mon, 5 Aug 2019 02:39:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727026AbfHECi7 (ORCPT ); Sun, 4 Aug 2019 22:38:59 -0400 Received: from out4436.biz.mail.alibaba.com ([47.88.44.36]:17597 "EHLO out4436.biz.mail.alibaba.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726767AbfHECi6 (ORCPT ); Sun, 4 Aug 2019 22:38:58 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e07417;MF=chge@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0TYeMK0t_1564972735; Received: from IT-C02YD3Q7JG5H.local(mailfrom:chge@linux.alibaba.com fp:SMTPD_---0TYeMK0t_1564972735) by smtp.aliyun-inc.com(127.0.0.1); Mon, 05 Aug 2019 10:38:56 +0800 Subject: Re: [Ocfs2-devel] [PATCH 2/3] fs: ocfs2: Fix a possible null-pointer dereference in ocfs2_write_end_nolock() To: Joseph Qi , Jia-Ju Bai , mark@fasheh.com, jlbec@evilplan.org Cc: linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com, Andrew Morton References: <20190726033705.32307-1-baijiaju1990@gmail.com> From: Changwei Ge Message-ID: <20d02767-6e14-c04f-4fcf-11ed2cbd63a2@linux.alibaba.com> Date: Mon, 5 Aug 2019 10:38:55 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jia-ju, Could you please point out how ->w_handle can be NULL if we are changing disk inode? I just checked the ocfs2 code but can't find any clue ... In my opinion, it's impossible to change disk inode without an existed journal transaction. If truly so, it's a another problem. Thanks, Changwei On 2019/7/26 5:38 下午, Joseph Qi wrote: > > On 19/7/26 11:37, Jia-Ju Bai wrote: >> In ocfs2_write_end_nolock(), there are an if statement on lines 1976, >> 2047 and 2058, to check whether handle is NULL: >> if (handle) >> >> When handle is NULL, it is used on line 2045: >> ocfs2_update_inode_fsync_trans(handle, inode, 1); >> oi->i_sync_tid = handle->h_transaction->t_tid; >> >> Thus, a possible null-pointer dereference may occur. >> >> To fix this bug, handle is checked before calling >> ocfs2_update_inode_fsync_trans(). >> >> This bug is found by a static analysis tool STCheck written by us. >> >> Signed-off-by: Jia-Ju Bai > Looks good. > Reviewed-by: Joseph Qi > >> --- >> fs/ocfs2/aops.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c >> index a4c905d6b575..5473bd99043e 100644 >> --- a/fs/ocfs2/aops.c >> +++ b/fs/ocfs2/aops.c >> @@ -2042,7 +2042,8 @@ int ocfs2_write_end_nolock(struct address_space *mapping, >> inode->i_mtime = inode->i_ctime = current_time(inode); >> di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec); >> di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec); >> - ocfs2_update_inode_fsync_trans(handle, inode, 1); >> + if (handle) >> + ocfs2_update_inode_fsync_trans(handle, inode, 1); >> } >> if (handle) >> ocfs2_journal_dirty(handle, wc->w_di_bh); >> > _______________________________________________ > Ocfs2-devel mailing list > Ocfs2-devel@oss.oracle.com > https://oss.oracle.com/mailman/listinfo/ocfs2-devel