[fix] Add input parameter validation for GetUserList

Change-Id: Ide73c817315e939ffffc92e96f2b608ec85b482b

diff --git a/sessiond/src/main.cpp b/sessiond/src/main.cpp
index 74bd6214954d40d29a00ead7a1e02280a5aed022..5fb4f39ee6b6ec9ef27478780f16d16a799f45eb 100644 (file)
--- a/sessiond/src/main.cpp
+++ b/sessiond/src/main.cpp
@@ -276,6 +276,11 @@ struct sessiond_context {
        {
                auto [ session_uid ] = tuple_from_g_variant<int>(parameters);
 
+               if (session_uid <= 0) {
+                       g_dbus_method_invocation_return_dbus_error(invocation, "org.freedesktop.DBus.Error.InvalidArgs", "Negative UID passed");
+                       return;
+               }
+
                auto users = fs_helpers::get_user_list(session_uid);
 
                // TODO: It would be cool to be able to use vals_to_g_variant here.