Date:   Fri,  3 Feb 2023 17:39:36 +0800
Mime-Version: 1.0
Message-ID: <20230203173900.1.I9ca803e2f809e339da43c103860118e7381e4871@changeid>
Subject: [PATCH] Bluetooth: Make sure LE create conn cancel is sent when timeout
From:   Archie Pusaka <apusaka@google.com>
To:     linux-bluetooth <linux-bluetooth@vger.kernel.org>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
        Marcel Holtmann <marcel@holtmann.org>
Cc:     CrosBT Upstreaming <chromeos-bluetooth-upstreaming@chromium.org>,
        Archie Pusaka <apusaka@chromium.org>,
        Ying Hsu <yinghsu@chromium.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Paolo Abeni <pabeni@redhat.com>, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

From: Archie Pusaka <apusaka@chromium.org>

When sending LE create conn command, we set a timer with a duration of
HCI_LE_CONN_TIMEOUT before timing out and calling
create_le_conn_complete. Additionally, when receiving the command
complete, we also set a timer with the same duration to call
le_conn_timeout.

Usually the latter will be triggered first, which then sends a LE
create conn cancel command. However, due to the nature of racing, it
is possible for the former to be called first, thereby calling the
chain hci_conn_failed -> hci_conn_del -> cancel_delayed_work, thereby
preventing LE create conn cancel to be sent. In this situation, the
controller will be stuck in trying the LE connection.

This patch flushes le_conn_timeout on create_le_conn_complete to make
sure we always send LE create connection cancel, if necessary.

Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Ying Hsu <yinghsu@chromium.org>

---

 net/bluetooth/hci_conn.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 61a34801e61e..f2c7edaa7145 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1243,6 +1243,8 @@ static void create_le_conn_complete(struct hci_dev *hdev, void *data, int err)
 	if (conn != hci_lookup_le_connect(hdev))
 		goto done;
 
+	/* Flush to make sure we send create conn cancel command if needed */
+	flush_delayed_work(&conn->le_conn_timeout);
 	hci_conn_failed(conn, bt_status(err));
 
 done:
-- 
2.39.1.519.gcb327c4b5f-goog