diff -up lua-5.4.0/src/ldebug.c.CVE-2020-24369 lua-5.4.0/src/ldebug.c
--- lua-5.4.0/src/ldebug.c.CVE-2020-24369	2020-08-19 12:43:01.995387723 -0400
+++ lua-5.4.0/src/ldebug.c	2020-08-19 12:43:42.191333666 -0400
@@ -783,11 +783,13 @@ l_noret luaG_runerror (lua_State *L, con
 ** previous instruction 'oldpc'.
 */
 static int changedline (const Proto *p, int oldpc, int newpc) {
+  if (p->lineinfo == NULL)  /* no debug information? */
+    return 0;
   while (oldpc++ < newpc) {
     if (p->lineinfo[oldpc] != 0)
       return (luaG_getfuncline(p, oldpc - 1) != luaG_getfuncline(p, newpc));
   }
-  return 0;  /* no line changes in the way */
+  return 0;  /* no line changes between positions */
 }
 
 /*