gdbus: Fix invalid memory access while unregistering

If an interface is added and removed on the same mailoop iteration,
ObjectManager would try to send InterfacesAdded signal while running the
idler because the interface was added to data->added list.

This is easily reproduced by forcing an error path in a plugin
registration, like on sap_server_register(), resulting in the following
error:

==11795== Invalid read of size 4
==11795==    at 0x496F592: dbus_message_iter_append_basic (dbus-message.c:2598)
==11795==    by 0x117B39: append_interface (object.c:554)
==11795==    by 0x48955E7: g_slist_foreach (gslist.c:840)
==11795==    by 0x11923B: process_changes (object.c:592)
==11795==    by 0x11956D: generic_unregister (object.c:980)
==11795==    by 0x4973BAC: _dbus_object_tree_unregister_and_unlock (dbus-object-tree.c:516)
==11795==    by 0x4965240: dbus_connection_unregister_object_path (dbus-connection.c:5776)
==11795==    by 0x1178A5: object_path_unref (object.c:1219)
==11795==    by 0x118517: g_dbus_unregister_interface (object.c:1344)
==11795==    by 0x19AF5B: sap_exit (sap.c:385)
==11795==    by 0x13E9E2: sap_server_register (server.c:1428)
==11795==    by 0x13C092: sap_server_probe (manager.c:44)

With this patch we don't send the InterfacesAdded signal, removing it
from data->added while unregistering.
This commit is contained in:
Lucas De Marchi 2012-10-04 17:42:33 -03:00 committed by Marcel Holtmann
parent a8e02420b4
commit 7071d8a28e
1 changed files with 11 additions and 0 deletions

View File

@ -657,6 +657,17 @@ static gboolean remove_interface(struct generic_data *data, const char *name)
return TRUE;
}
/*
* Interface being removed was just added, on the same mainloop
* iteration? Don't send any signal
*/
if (g_slist_find(data->added, iface)) {
data->added = g_slist_remove(data->added, iface);
g_free(iface->name);
g_free(iface);
return TRUE;
}
data->removed = g_slist_prepend(data->removed, iface->name);
g_free(iface);