ubus: Fix imbalance in lua stack push/pop of values.

The lua getglobal and rawgeti both push a value onto the lua stack,
but they weren't being removed by the ubus_method_handler function,
thus corrupting the lua stack.

In case the specified method wasn't a function, the stack was also
corrupted as the method name remained on the stack.

Signed-off-by: Karl Vogel <karl.vogel@gmail.com>

diff --git a/lua/ubus.c b/lua/ubus.c
index 6da935d39a1976b157fd103168c197e6eb26d0bb..0f2338c9420d6d323c637717283182c6fc3fb6d4 100644 (file)
--- a/lua/ubus.c
+++ b/lua/ubus.c
@@ -289,6 +289,8 @@ ubus_method_handler(struct ubus_context *ctx, struct ubus_object *obj,
        lua_getglobal(state, "__ubus_cb");
        lua_rawgeti(state, -1, o->r);
        lua_getfield(state, -1, method);
+       lua_remove(state, -2);
+       lua_remove(state, -2);
 
        if (lua_isfunction(state, -1)) {
                lua_pushlightuserdata(state, req);
@@ -297,7 +299,9 @@ ubus_method_handler(struct ubus_context *ctx, struct ubus_object *obj,
                else
                        ubus_lua_parse_blob_array(state, blob_data(msg), blob_len(msg), true);
                lua_call(state, 2, 0);
-       }
+       } else
+               lua_pop(state, 1);
+
        return 0;
 }