Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 2 Feb 2021 14:32:03 +0300
From:   Dan Carpenter <dan.carpenter@oracle.com>
To:     Mark Fasheh <mark@fasheh.com>
Cc:     Joel Becker <jlbec@evilplan.org>,
        Joseph Qi <joseph.qi@linux.alibaba.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Takashi Iwai <tiwai@suse.de>, Jens Axboe <axboe@kernel.dk>,
        Alex Shi <alex.shi@linux.alibaba.com>,
        Jiri Slaby <jirislaby@kernel.org>, ocfs2-devel@oss.oracle.com,
        linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH v2] ocfs2: Fix a use after free on error
Message-ID: <YBk4M6HUG8jB/jc7@mwanda>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Precedence: bulk

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 <dan.carpenter@oracle.com>
---
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, &reg->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(&reg->hr_handler_list);
+remove_item:
+	spin_lock(&o2hb_live_lock);
+	list_del(&reg->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);
-- 
2.30.0