From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Subject: [PATCH 2/2] Bluetooth: L2CAP: Delay identity address updates
Date:   Thu,  9 Mar 2023 16:00:55 -0800
Message-Id: <20230310000055.3396026-2-luiz.dentz@gmail.com>
In-Reply-To: <20230310000055.3396026-1-luiz.dentz@gmail.com>
References: <20230310000055.3396026-1-luiz.dentz@gmail.com>
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From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This delays the identity address updates to give time for userspace to
process the new address otherwise there is a risk that userspace
creates a duplicated device if the MGMT event is delayed for some
reason.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 include/net/bluetooth/l2cap.h | 2 +-
 net/bluetooth/l2cap_core.c    | 7 +++----
 net/bluetooth/smp.c           | 9 ++++++++-
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 2f766e3437ce..cf393e72d6ed 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -694,7 +694,7 @@ struct l2cap_conn {
 	struct sk_buff_head	pending_rx;
 	struct work_struct	pending_rx_work;
 
-	struct work_struct	id_addr_update_work;
+	struct delayed_work	id_addr_timer;
 
 	__u8			disc_reason;
 
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 49926f59cc12..8153293b9a45 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -745,7 +745,7 @@ EXPORT_SYMBOL_GPL(l2cap_chan_list);
 static void l2cap_conn_update_id_addr(struct work_struct *work)
 {
 	struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
-					       id_addr_update_work);
+					       id_addr_timer.work);
 	struct hci_conn *hcon = conn->hcon;
 	struct l2cap_chan *chan;
 
@@ -1907,8 +1907,7 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
 	if (work_pending(&conn->pending_rx_work))
 		cancel_work_sync(&conn->pending_rx_work);
 
-	if (work_pending(&conn->id_addr_update_work))
-		cancel_work_sync(&conn->id_addr_update_work);
+	cancel_delayed_work_sync(&conn->id_addr_timer);
 
 	l2cap_unregister_all_users(conn);
 
@@ -7886,7 +7885,7 @@ static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon)
 
 	skb_queue_head_init(&conn->pending_rx);
 	INIT_WORK(&conn->pending_rx_work, process_pending_rx);
-	INIT_WORK(&conn->id_addr_update_work, l2cap_conn_update_id_addr);
+	INIT_DELAYED_WORK(&conn->id_addr_timer, l2cap_conn_update_id_addr);
 
 	conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
 
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 70663229b3cc..f1a9fc0012f0 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -58,6 +58,8 @@
 
 #define SMP_TIMEOUT	msecs_to_jiffies(30000)
 
+#define ID_ADDR_TIMEOUT	msecs_to_jiffies(200)
+
 #define AUTH_REQ_MASK(dev)	(hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \
 				 0x3f : 0x07)
 #define KEY_DIST_MASK		0x07
@@ -1067,7 +1069,12 @@ static void smp_notify_keys(struct l2cap_conn *conn)
 		if (hcon->type == LE_LINK) {
 			bacpy(&hcon->dst, &smp->remote_irk->bdaddr);
 			hcon->dst_type = smp->remote_irk->addr_type;
-			queue_work(hdev->workqueue, &conn->id_addr_update_work);
+			/* Use a short delay to make sure the new address is
+			 * propagated _before_ the channels.
+			 */
+			queue_delayed_work(hdev->workqueue,
+					   &conn->id_addr_timer,
+					   ID_ADDR_TIMEOUT);
 		}
 	}
 
-- 
2.39.2