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=-15.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 8656AC433DB for ; Tue, 2 Feb 2021 12:10:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C19864DDC for ; Tue, 2 Feb 2021 12:10:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231201AbhBBMKU (ORCPT ); Tue, 2 Feb 2021 07:10:20 -0500 Received: from out30-57.freemail.mail.aliyun.com ([115.124.30.57]:59406 "EHLO out30-57.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231299AbhBBMJW (ORCPT ); Tue, 2 Feb 2021 07:09:22 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04420;MF=joseph.qi@linux.alibaba.com;NM=1;PH=DS;RN=11;SR=0;TI=SMTPD_---0UNgkalg_1612267708; Received: from B-D1K7ML85-0059.local(mailfrom:joseph.qi@linux.alibaba.com fp:SMTPD_---0UNgkalg_1612267708) by smtp.aliyun-inc.com(127.0.0.1); Tue, 02 Feb 2021 20:08:29 +0800 Subject: Re: [PATCH v2] ocfs2: Fix a use after free on error To: Dan Carpenter , Mark Fasheh Cc: Joel Becker , Andrew Morton , Takashi Iwai , Jens Axboe , Alex Shi , Jiri Slaby , ocfs2-devel@oss.oracle.com, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org References: From: Joseph Qi Message-ID: <56634c6b-1c68-83dc-e372-09fd4bda3c7d@linux.alibaba.com> Date: Tue, 2 Feb 2021 20:08:28 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/2/21 7:32 PM, Dan Carpenter wrote: > The error handling in this function frees "reg" but it is still on the > "o2hb_all_regions" list so it will lead to a use after freew. Joseph Qi > points out that we need to clear the bit in the "o2hb_region_bitmap" as > well > > Fixes: 1cf257f51191 ("ocfs2: fix memory leak") > Signed-off-by: Dan Carpenter Looks good. Reviewed-by: Joseph Qi > --- > v2: The first version didn't clear the bit. > > fs/ocfs2/cluster/heartbeat.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c > index 0179a73a3fa2..12a7590601dd 100644 > --- a/fs/ocfs2/cluster/heartbeat.c > +++ b/fs/ocfs2/cluster/heartbeat.c > @@ -2042,7 +2042,7 @@ static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *g > o2hb_nego_timeout_handler, > reg, NULL, ®->hr_handler_list); > if (ret) > - goto free; > + goto remove_item; > > ret = o2net_register_handler(O2HB_NEGO_APPROVE_MSG, reg->hr_key, > sizeof(struct o2hb_nego_msg), > @@ -2057,6 +2057,12 @@ static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *g > > unregister_handler: > o2net_unregister_handler_list(®->hr_handler_list); > +remove_item: > + spin_lock(&o2hb_live_lock); > + list_del(®->hr_all_item); > + if (o2hb_global_heartbeat_active()) > + clear_bit(reg->hr_region_num, o2hb_region_bitmap); > + spin_unlock(&o2hb_live_lock); > free: > kfree(reg); > return ERR_PTR(ret); >