3 files changed, 53 insertions, 9 deletions

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 5236faa397fa..beda5dac1658 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3990,6 +3990,7 @@ int hci_register_dev(struct hci_dev *hdev)
 	queue_work(hdev->req_workqueue, &hdev->power_on);
 
 	idr_init(&hdev->adv_monitors_idr);
+	msft_register(hdev);
 
 	return id;
 
@@ -4022,6 +4023,8 @@ void hci_unregister_dev(struct hci_dev *hdev)
 		cancel_work_sync(&hdev->suspend_prepare);
 	}
 
+	msft_unregister(hdev);
+
 	hci_dev_do_close(hdev);
 
 	if (!test_bit(HCI_INIT, &hdev->flags) &&
diff --git a/net/bluetooth/msft.c b/net/bluetooth/msft.c
index b4bfae41e8a5..21b1787e7893 100644
--- a/net/bluetooth/msft.c
+++ b/net/bluetooth/msft.c
@@ -184,28 +184,36 @@ static void reregister_monitor_on_restart(struct hci_dev *hdev, int handle)
 
 void msft_do_open(struct hci_dev *hdev)
 {
-	struct msft_data *msft;
+	struct msft_data *msft = hdev->msft_data;
 
 	if (hdev->msft_opcode == HCI_OP_NOP)
 		return;
 
+	if (!msft) {
+		bt_dev_err(hdev, "MSFT extension not registered");
+		return;
+	}
+
 	bt_dev_dbg(hdev, "Initialize MSFT extension");
 
-	msft = kzalloc(sizeof(*msft), GFP_KERNEL);
-	if (!msft)
-		return;
+	/* Reset existing MSFT data before re-reading */
+	kfree(msft->evt_prefix);
+	msft->evt_prefix = NULL;
+	msft->evt_prefix_len = 0;
+	msft->features = 0;
 
 	if (!read_supported_features(hdev, msft)) {
+		hdev->msft_data = NULL;
 		kfree(msft);
 		return;
 	}
 
-	INIT_LIST_HEAD(&msft->handle_map);
-	hdev->msft_data = msft;
-
 	if (msft_monitor_supported(hdev)) {
 		msft->reregistering = true;
 		msft_set_filter_enable(hdev, true);
+		/* Monitors get removed on power off, so we need to explicitly
+		 * tell the controller to re-monitor.
+		 */
 		reregister_monitor_on_restart(hdev, 0);
 	}
 }
@@ -221,8 +229,9 @@ void msft_do_close(struct hci_dev *hdev)
 
 	bt_dev_dbg(hdev, "Cleanup of MSFT extension");
 
-	hdev->msft_data = NULL;
-
+	/* The controller will silently remove all monitors on power off.
+	 * Therefore, remove handle_data mapping and reset monitor state.
+	 */
 	list_for_each_entry_safe(handle_data, tmp, &msft->handle_map, list) {
 		monitor = idr_find(&hdev->adv_monitors_idr,
 				   handle_data->mgmt_handle);
@@ -233,6 +242,34 @@ void msft_do_close(struct hci_dev *hdev)
 		list_del(&handle_data->list);
 		kfree(handle_data);
 	}
+}
+
+void msft_register(struct hci_dev *hdev)
+{
+	struct msft_data *msft = NULL;
+
+	bt_dev_dbg(hdev, "Register MSFT extension");
+
+	msft = kzalloc(sizeof(*msft), GFP_KERNEL);
+	if (!msft) {
+		bt_dev_err(hdev, "Failed to register MSFT extension");
+		return;
+	}
+
+	INIT_LIST_HEAD(&msft->handle_map);
+	hdev->msft_data = msft;
+}
+
+void msft_unregister(struct hci_dev *hdev)
+{
+	struct msft_data *msft = hdev->msft_data;
+
+	if (!msft)
+		return;
+
+	bt_dev_dbg(hdev, "Unregister MSFT extension");
+
+	hdev->msft_data = NULL;
 
 	kfree(msft->evt_prefix);
 	kfree(msft);
diff --git a/net/bluetooth/msft.h b/net/bluetooth/msft.h
index 6e56d94b88d8..8018948c5975 100644
--- a/net/bluetooth/msft.h
+++ b/net/bluetooth/msft.h
@@ -13,6 +13,8 @@
 #if IS_ENABLED(CONFIG_BT_MSFTEXT)
 
 bool msft_monitor_supported(struct hci_dev *hdev);
+void msft_register(struct hci_dev *hdev);
+void msft_unregister(struct hci_dev *hdev);
 void msft_do_open(struct hci_dev *hdev);
 void msft_do_close(struct hci_dev *hdev);
 void msft_vendor_evt(struct hci_dev *hdev, struct sk_buff *skb);
@@ -31,6 +33,8 @@ static inline bool msft_monitor_supported(struct hci_dev *hdev)
 	return false;
 }
 
+static inline void msft_register(struct hci_dev *hdev) {}
+static inline void msft_unregister(struct hci_dev *hdev) {}
 static inline void msft_do_open(struct hci_dev *hdev) {}
 static inline void msft_do_close(struct hci_dev *hdev) {}
 static inline void msft_vendor_evt(struct hci_dev *hdev, struct sk_buff *skb) {}