[Tarantool-patches] [PATCH] Stack use after scope

[Maria]

Json decode method allocated serializer struct on stack and referenced
it after scope.

Thanks to @Korablev77 for the initial investigation.

Closes #4637
---
 third_party/lua-cjson/lua_cjson.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/third_party/lua-cjson/lua_cjson.c b/third_party/lua-cjson/lua_cjson.c
index 3d7edbf28..3d25814f3 100644
--- a/third_party/lua-cjson/lua_cjson.c
+++ b/third_party/lua-cjson/lua_cjson.c
@@ -1005,10 +1005,10 @@ static int json_decode(lua_State *l)
                   "expected 1 or 2 arguments");
 
     if (lua_gettop(l) == 2) {
-        struct luaL_serializer user_cfg = *luaL_checkserializer(l);
-        luaL_serializer_parse_options(l, &user_cfg);
+        struct luaL_serializer *user_cfg = luaL_checkserializer(l);
+        luaL_serializer_parse_options(l, user_cfg);
         lua_pop(l, 1);
-        json.cfg = &user_cfg;
+        json.cfg = user_cfg;
     } else {
         json.cfg = luaL_checkserializer(l);
     }
-- 
2.20.1 (Apple Git-117)