libqmi-glib,device: avoid invalid reads in the sync indication callback

If we don't disconnect the signal handler when we clear the private
QmiClientCtl, we may end up in the situation where we try to use the
already disposed QmiDevice object.

1 files changed, 12 insertions, 4 deletions

diff --git a/libqmi-glib/qmi-device.c b/libqmi-glib/qmi-device.c
index e8d801c..1c4c567 100644
--- a/libqmi-glib/qmi-device.c
+++ b/libqmi-glib/qmi-device.c
@@ -71,6 +71,7 @@ struct _QmiDevicePrivate {
 
     /* Implicit CTL client */
     QmiClientCtl *client_ctl;
+    guint sync_indication_id;
 
     /* Supported services */
     GArray *supported_services;
@@ -1927,10 +1928,11 @@ query_info_async_ready (GFile *file,
     g_assert_no_error (error);
 
     /* Connect to 'Sync' indications */
-    g_signal_connect (ctx->self->priv->client_ctl,
-                      "sync",
-                      G_CALLBACK (sync_indication_cb),
-                      ctx->self);
+    ctx->self->priv->sync_indication_id =
+        g_signal_connect (ctx->self->priv->client_ctl,
+                          "sync",
+                          G_CALLBACK (sync_indication_cb),
+                          ctx->self);
 
     /* Done we are */
     g_simple_async_result_set_op_res_gboolean (ctx->result, TRUE);
@@ -2061,6 +2063,12 @@ dispose (GObject *object)
                                  (GHRFunc)foreach_warning,
                                  self);
 
+    if (self->priv->sync_indication_id &&
+        self->priv->client_ctl) {
+        g_signal_handler_disconnect (self->priv->client_ctl,
+                                     self->priv->sync_indication_id);
+        self->priv->sync_indication_id = 0;
+    }
     g_clear_object (&self->priv->client_ctl);
 
     G_OBJECT_CLASS (qmi_device_parent_class)->dispose (object);