Bluetooth: hci_conn: hold conn references in hci_sync tasks

index 1966cd153d97..6036ff66d8d9 100644
@@ -3163,6 +3163,13 @@ static int abort_conn_sync(struct hci_dev *hdev, void *data)
 	return hci_abort_conn_sync(hdev, conn, conn->abort_reason);
 }
 
+static void abort_conn_destroy(struct hci_dev *hdev, void *data, int err)
+{
+	struct hci_conn *conn = data;
+
+	hci_conn_put(conn);
+}
+
 int hci_abort_conn(struct hci_conn *conn, u8 reason)
 {
 	struct hci_dev *hdev = conn->hdev;

@@ -3188,7 +3195,10 @@ int hci_abort_conn(struct hci_conn *conn, u8 reason)
 	 * as a result to MGMT_OP_DISCONNECT/MGMT_OP_UNPAIR which does
 	 * already queue its callback on cmd_sync_work.
 	 */
-	err = hci_cmd_sync_run_once(hdev, abort_conn_sync, conn, NULL);
+	err = hci_cmd_sync_run_once(hdev, abort_conn_sync, hci_conn_get(conn),
+				    abort_conn_destroy);
+	if (err)
+		hci_conn_put(conn);
 	return (err == -EEXIST) ? 0 : err;
 }
 

index a693259dd3ee..66f42a3dc5a1 100644
@@ -7014,12 +7014,23 @@ static int hci_acl_create_conn_sync(struct hci_dev *hdev, void *data)
 	return err;
 }
 
+static void hci_acl_create_conn_sync_complete(struct hci_dev *hdev, void *data,
+					      int err)
+{
+	struct hci_conn *conn = data;
+
+	hci_conn_put(conn);
+}
+
 int hci_connect_acl_sync(struct hci_dev *hdev, struct hci_conn *conn)
 {
 	int err;
 
-	err = hci_cmd_sync_queue_once(hdev, hci_acl_create_conn_sync, conn,
-				      NULL);
+	err = hci_cmd_sync_queue_once(hdev, hci_acl_create_conn_sync,
+				      hci_conn_get(conn),
+				      hci_acl_create_conn_sync_complete);
+	if (err)
+		hci_conn_put(conn);
 	return (err == -EEXIST) ? 0 : err;
 }
 

@@ -7030,36 +7041,41 @@ static void create_le_conn_complete(struct hci_dev *hdev, void *data, int err)
 	bt_dev_dbg(hdev, "err %d", err);
 
 	if (err == -ECANCELED)
-		return;
+		goto done;
 
 	hci_dev_lock(hdev);
 
 	if (!hci_conn_valid(hdev, conn))
-		goto done;
+		goto unlock;
 
 	if (!err) {
 		hci_connect_le_scan_cleanup(conn, 0x00);
-		goto done;
+		goto unlock;
 	}
 
 	/* Check if connection is still pending */
 	if (conn != hci_lookup_le_connect(hdev))
-		goto done;
+		goto unlock;
 
 	/* 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:
+unlock:
 	hci_dev_unlock(hdev);
+done:
+	hci_conn_put(conn);
 }
 
 int hci_connect_le_sync(struct hci_dev *hdev, struct hci_conn *conn)
 {
 	int err;
 
-	err = hci_cmd_sync_queue_once(hdev, hci_le_create_conn_sync, conn,
+	err = hci_cmd_sync_queue_once(hdev, hci_le_create_conn_sync,
+				      hci_conn_get(conn),
 				      create_le_conn_complete);
+	if (err)
+		hci_conn_put(conn);
 	return (err == -EEXIST) ? 0 : err;
 }
 

index 66f42a3dc5a1..d8efd143135a 100644
@@ -7372,10 +7372,17 @@ static void create_big_complete(struct hci_dev *hdev, void *data, int err)
 	bt_dev_dbg(hdev, "err %d", err);
 
 	if (err == -ECANCELED)
-		return;
+		goto done;
+
+	rcu_read_lock();
 
 	if (hci_conn_valid(hdev, conn))
 		clear_bit(HCI_CONN_CREATE_BIG_SYNC, &conn->flags);
+
+	rcu_read_unlock();
+
+done:
+	hci_conn_put(conn);
 }
 
 static int hci_le_big_create_sync(struct hci_dev *hdev, void *data)

@@ -7427,8 +7434,14 @@ int hci_connect_big_sync(struct hci_dev *hdev, struct hci_conn *conn)
 {
 	int err;
 
-	err = hci_cmd_sync_queue_once(hdev, hci_le_big_create_sync, conn,
+	if (!conn)
+		return 0;
+
+	err = hci_cmd_sync_queue_once(hdev, hci_le_big_create_sync,
+				      hci_conn_get(conn),
 				      create_big_complete);
+	if (err)
+		hci_conn_put(conn);
 	return (err == -EEXIST) ? 0 : err;
 }
 

index d8efd143135a..56018214120b 100644
@@ -7198,7 +7198,7 @@ static void create_pa_complete(struct hci_dev *hdev, void *data, int err)
 	bt_dev_dbg(hdev, "err %d", err);
 
 	if (err == -ECANCELED)
-		return;
+		goto done;
 
 	hci_dev_lock(hdev);
 

@@ -7222,6 +7222,8 @@ static void create_pa_complete(struct hci_dev *hdev, void *data, int err)
 
 unlock:
 	hci_dev_unlock(hdev);
+done:
+	hci_conn_put(conn);
 }
 
 static int hci_le_past_params_sync(struct hci_dev *hdev, struct hci_conn *conn,

@@ -7360,8 +7362,11 @@ int hci_connect_pa_sync(struct hci_dev *hdev, struct hci_conn *conn)
 {
 	int err;
 
-	err = hci_cmd_sync_queue_once(hdev, hci_le_pa_create_sync, conn,
+	err = hci_cmd_sync_queue_once(hdev, hci_le_pa_create_sync,
+				      hci_conn_get(conn),
 				      create_pa_complete);
+	if (err)
+		hci_conn_put(conn);
 	return (err == -EEXIST) ? 0 : err;
 }
 

index 56018214120b..88572e52c860 100644
@@ -7461,6 +7461,8 @@ static void past_complete(struct hci_dev *hdev, void *data, int err)
 
 	bt_dev_dbg(hdev, "err %d", err);
 
+	hci_conn_put(past->conn);
+	hci_conn_put(past->le);
 	kfree(past);
 }
 

@@ -7525,8 +7527,8 @@ int hci_past_sync(struct hci_conn *conn, struct hci_conn *le)
 	if (!data)
 		return -ENOMEM;
 
-	data->conn = conn;
-	data->le = le;
+	data->conn = hci_conn_get(conn);
+	data->le = hci_conn_get(le);
 
 	if (conn->role == HCI_ROLE_MASTER)
 		err = hci_cmd_sync_queue_once(conn->hdev,

@@ -7536,8 +7538,11 @@ int hci_past_sync(struct hci_conn *conn, struct hci_conn *le)
 		err = hci_cmd_sync_queue_once(conn->hdev, hci_le_past_sync,
 					      data, past_complete);
 
-	if (err)
+	if (err) {
+		hci_conn_put(data->conn);
+		hci_conn_put(data->le);
 		kfree(data);
+	}
 
 	return (err == -EEXIST) ? 0 : err;
 }

index 88572e52c860..11d0c2033c6a 100644
@@ -6623,7 +6623,9 @@ static int hci_le_create_conn_sync(struct hci_dev *hdev, void *data)
 		if (hci_dev_test_flag(hdev, HCI_LE_SCAN) &&
 		    hdev->le_scan_type == LE_SCAN_ACTIVE &&
 		    !hci_dev_test_flag(hdev, HCI_LE_SIMULTANEOUS_ROLES)) {
-			hci_conn_del(conn);
+			conn->state = BT_OPEN;
+			hci_abort_conn_sync(hdev, conn,
+					    HCI_ERROR_REJ_LIMITED_RESOURCES);
 			hci_conn_put(conn);
 			return -EBUSY;
 		}

index 11d0c2033c6a..7cc3cb12436d 100644
@@ -6607,11 +6607,6 @@ static int hci_le_create_conn_sync(struct hci_dev *hdev, void *data)
 
 	bt_dev_dbg(hdev, "conn %p", conn);
 
-	/* Hold a reference so conn stays valid for the HCI_CONN_CREATE
-	 * clear_bit() at done.
-	 */
-	hci_conn_get(conn);
-
 	clear_bit(HCI_CONN_SCANNING, &conn->flags);
 	conn->state = BT_CONNECT;
 

@@ -6626,7 +6621,6 @@ static int hci_le_create_conn_sync(struct hci_dev *hdev, void *data)
 			conn->state = BT_OPEN;
 			hci_abort_conn_sync(hdev, conn,
 					    HCI_ERROR_REJ_LIMITED_RESOURCES);
-			hci_conn_put(conn);
 			return -EBUSY;
 		}
 

@@ -6720,7 +6714,6 @@ static int hci_le_create_conn_sync(struct hci_dev *hdev, void *data)
 
 	/* Re-enable advertising after the connection attempt is finished. */
 	hci_resume_advertising_sync(hdev);
-	hci_conn_put(conn);
 	return err;
 }
 

@@ -6995,11 +6988,6 @@ static int hci_acl_create_conn_sync(struct hci_dev *hdev, void *data)
 	else
 		cp.role_switch = 0x00;
 
-	/* Hold a reference so conn stays valid for the HCI_CONN_CREATE
-	 * clear_bit() below.
-	 */
-	hci_conn_get(conn);
-
 	/* Mark create connection in flight so hci_cancel_connect_sync() can
 	 * cancel it while blocking on the connection complete event.
 	 */

@@ -7011,7 +6999,6 @@ static int hci_acl_create_conn_sync(struct hci_dev *hdev, void *data)
 				       conn->conn_timeout, NULL);
 
 	clear_bit(HCI_CONN_CREATE, &conn->flags);
-	hci_conn_put(conn);
 
 	return err;
 }