lua

commit cf613cdc6fa367257fc61c256f63d917350858b5
parent 066e0f93c4901e601d93e31fb700f8f66f95feb8
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date:   Wed, 15 Dec 2021 11:28:40 -0300

Bug: finalizers can be called with an invalid stack

The call to 'checkstackGC' can run finalizers, which will find an
inconsistent CallInfo, as 'ci' is half updated at the point of call.

Diffstat:
M
ldo.c
 | 
2
+-

1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/ldo.c b/ldo.c
@@ -530,10 +530,10 @@ int luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func,
       int fsize = p->maxstacksize;  /* frame size */
       int nfixparams = p->numparams;
       int i;
+      checkstackGCp(L, fsize - delta, func);
       ci->func -= delta;  /* restore 'func' (if vararg) */
       for (i = 0; i < narg1; i++)  /* move down function and arguments */
         setobjs2s(L, ci->func + i, func + i);
-      checkstackGC(L, fsize);
       func = ci->func;  /* moved-down function */
       for (; narg1 <= nfixparams; narg1++)
         setnilvalue(s2v(func + narg1));  /* complete missing arguments */