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From:   Jianglei Nie <niejianglei2021@163.com>
To:     marcel@holtmann.org, johan.hedberg@gmail.com, luiz.dentz@gmail.com,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com
Cc:     linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Jianglei Nie <niejianglei2021@163.com>
Subject: [PATCH] Bluetooth: hci_conn: fix potential double free in le_scan_cleanup()
Date:   Thu, 26 May 2022 17:49:18 +0800
Message-Id: <20220526094918.482971-1-niejianglei2021@163.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

When "c == conn" is true, hci_conn_cleanup() is called. The
hci_conn_cleanup() calls hci_dev_put() and hci_conn_put() in
its function implementation. hci_dev_put() and hci_conn_put()
will free the relevant resource if the reference count reaches
zero, which may lead to a double free when hci_dev_put() and
hci_conn_put() are called again.

We should add a return to this function after hci_conn_cleanup()
is called.

Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
---
 net/bluetooth/hci_conn.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index fe803bee419a..7b3e91eb9fa3 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -166,6 +166,7 @@ static void le_scan_cleanup(struct work_struct *work)
 	if (c == conn) {
 		hci_connect_le_scan_cleanup(conn);
 		hci_conn_cleanup(conn);
+		return;
 	}
 
 	hci_dev_unlock(hdev);
-- 
2.25.1