mm-base-manager: ref MMDevice before releasing port

Releasing the port on the device looks benign but because it emits
a signal, it could call device_context_port_released and unref the
MMDevice in port_context_unref. This means the MMDevice might be
disposed before we get to the g_object_ref and the subsequent call
to g_hash_table_remove will try to hash a null string, which makes
MM crash.
This commit is contained in:
Eric Caruso
2018-02-21 13:49:34 -08:00
committed by Aleksander Morgado
parent d416ea491d
commit 402559bb62

View File

@@ -220,28 +220,28 @@ device_removed (MMBaseManager *self,
/* Handle tty/net/wdm port removal */
device = find_device_by_port (self, kernel_device);
if (device) {
/* The callbacks triggered when the port is released or device support is
* cancelled may end up unreffing the device or removing it from the HT, and
* so in order to make sure the reference is still valid when we call
* support_check_cancel() and g_hash_table_remove(), we hold a full reference
* ourselves. */
g_object_ref (device);
mm_info ("(%s/%s): released by device '%s'", subsys, name, mm_device_get_uid (device));
mm_device_release_port (device, kernel_device);
/* If port probe list gets empty, remove the device object iself */
if (!mm_device_peek_port_probe_list (device)) {
/* The callback triggered when the device support is cancelled may end up
* removing the device from the HT, and that was the last full reference
* we kept. So, in order to make sure the reference is still valid after
* support_check_cancel(), we hold a full reference ourselves. */
mm_dbg ("Removing empty device '%s'", mm_device_get_uid (device));
g_object_ref (device);
{
if (mm_plugin_manager_device_support_check_cancel (self->priv->plugin_manager, device))
mm_dbg ("Device support check has been cancelled");
if (mm_plugin_manager_device_support_check_cancel (self->priv->plugin_manager, device))
mm_dbg ("Device support check has been cancelled");
/* The device may have already been removed from the tracking HT, we
* just try to remove it and if it fails, we ignore it */
mm_device_remove_modem (device);
g_hash_table_remove (self->priv->devices, mm_device_get_uid (device));
}
g_object_unref (device);
/* The device may have already been removed from the tracking HT, we
* just try to remove it and if it fails, we ignore it */
mm_device_remove_modem (device);
g_hash_table_remove (self->priv->devices, mm_device_get_uid (device));
}
g_object_unref (device);
}
return;