From 6fb99d6b1ebc5bf3bbd8edef199fd0bc8b34100f Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Fri, 29 Dec 2023 09:45:38 +1100
Subject: [PATCH] AP_Scripting: fixed use after free bug

found with valgrind
---
 libraries/AP_Scripting/lua_scripts.cpp | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/libraries/AP_Scripting/lua_scripts.cpp b/libraries/AP_Scripting/lua_scripts.cpp
index d1c8badff71d95..b1b60a29c8a711 100644
--- a/libraries/AP_Scripting/lua_scripts.cpp
+++ b/libraries/AP_Scripting/lua_scripts.cpp
@@ -402,19 +402,18 @@ void lua_scripts::remove_script(lua_State *L, script_info *script) {
         }
     }
 
+    {
+        // Remove from running checksum
+        WITH_SEMAPHORE(crc_sem);
+        running_checksum ^= script->crc;
+    }
+    
     if (L != nullptr) {
         // state could be null if we are force killing all scripts
         luaL_unref(L, LUA_REGISTRYINDEX, script->lua_ref);
     }
     _heap.deallocate(script->name);
     _heap.deallocate(script);
-
-    {
-        // Remove from running checksum
-        WITH_SEMAPHORE(crc_sem);
-        running_checksum ^= script->crc;
-    }
-
 }
 
 void lua_scripts::reschedule_script(script_info *script) {