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.
This commit is contained in:
Roberto Ierusalimschy 2021-12-15 11:29:07 -03:00
parent 066e0f93c4
commit cf613cdc6f

2
ldo.c
View File

@ -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 */