From:   Hangyu Hua <hbh25y@gmail.com>
To:     pshelar@ovn.org, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com, xiangxia.m.yue@gmail.com,
        echaudro@redhat.com
Cc:     netdev@vger.kernel.org, dev@openvswitch.org,
        linux-kernel@vger.kernel.org, Hangyu Hua <hbh25y@gmail.com>
Subject: [PATCH v2] net: openvswitch: fix possible memory leak in ovs_meter_cmd_set()
Date:   Thu,  9 Feb 2023 17:32:40 +0800
Message-Id: <20230209093240.14685-1-hbh25y@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

old_meter needs to be free after it is detached regardless of whether
the new meter is successfully attached.

Fixes: c7c4c44c9a95 ("net: openvswitch: expand the meters supported number")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
---

v2: use goto label and free old_meter outside of ovs lock.

 net/openvswitch/meter.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/net/openvswitch/meter.c b/net/openvswitch/meter.c
index 6e38f68f88c2..9b680f0894f1 100644
--- a/net/openvswitch/meter.c
+++ b/net/openvswitch/meter.c
@@ -417,6 +417,7 @@ static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
 	int err;
 	u32 meter_id;
 	bool failed;
+	bool locked = true;
 
 	if (!a[OVS_METER_ATTR_ID])
 		return -EINVAL;
@@ -448,11 +449,13 @@ static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
 		goto exit_unlock;
 
 	err = attach_meter(meter_tbl, meter);
-	if (err)
-		goto exit_unlock;
 
 	ovs_unlock();
 
+	if (err) {
+		locked = false;
+		goto exit_free_old_meter;
+	}
 	/* Build response with the meter_id and stats from
 	 * the old meter, if any.
 	 */
@@ -472,8 +475,11 @@ static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
 	genlmsg_end(reply, ovs_reply_header);
 	return genlmsg_reply(reply, info);
 
+exit_free_old_meter:
+	ovs_meter_free(old_meter);
 exit_unlock:
-	ovs_unlock();
+	if (locked)
+		ovs_unlock();
 	nlmsg_free(reply);
 exit_free_meter:
 	kfree(meter);
-- 
2.34.1