From: Karl Vogel <karl.vogel@gmail.com>
Date: Tue, 11 Feb 2014 08:27:36 +0000 (+0100)
Subject: ubus: Fix imbalance in lua stack push/pop of values.
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=334c38918063b5ece164624e20490021b2bff38a;p=project%2Fubus.git

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 6da935d..0f2338c 100644
--- 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;
 }