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author | Roberto Ierusalimschy <roberto@inf.puc-rio.br> | 2013-04-19 18:03:23 -0300 |
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committer | Roberto Ierusalimschy <roberto@inf.puc-rio.br> | 2013-04-19 18:03:23 -0300 |
commit | c2ea18726a466fd3c84446eb002e060c04815521 (patch) | |
tree | f495c4ec0961deb02fb29782e0764c4922a999fd | |
parent | 2ca518141350667e38941eac35b76980095d2fdc (diff) | |
download | lua-github-c2ea18726a466fd3c84446eb002e060c04815521.tar.gz |
BUG: stack overflow in vararg functions with many fixed
parameters called with few arguments
-rw-r--r-- | ldo.c | 15 |
1 files changed, 11 insertions, 4 deletions
@@ -1,5 +1,5 @@ /* -** $Id: ldo.c,v 2.108 2012/10/01 14:05:04 roberto Exp $ +** $Id: ldo.c,v 2.108.1.1 2013/04/12 18:48:47 roberto Exp roberto $ ** Stack and Call structure of Lua ** See Copyright Notice in lua.h */ @@ -260,6 +260,7 @@ static StkId adjust_varargs (lua_State *L, Proto *p, int actual) { StkId base, fixed; lua_assert(actual >= nfixargs); /* move fixed parameters to final position */ + luaD_checkstack(L, p->maxstacksize); /* check again for new 'base' */ fixed = L->top - actual; /* first fixed argument */ base = L->top; /* final position of first argument */ for (i=0; i<nfixargs; i++) { @@ -324,12 +325,18 @@ int luaD_precall (lua_State *L, StkId func, int nresults) { case LUA_TLCL: { /* Lua function: prepare its call */ StkId base; Proto *p = clLvalue(func)->p; - luaD_checkstack(L, p->maxstacksize); - func = restorestack(L, funcr); n = cast_int(L->top - func) - 1; /* number of real arguments */ + luaD_checkstack(L, p->maxstacksize); for (; n < p->numparams; n++) setnilvalue(L->top++); /* complete missing arguments */ - base = (!p->is_vararg) ? func + 1 : adjust_varargs(L, p, n); + if (!p->is_vararg) { + func = restorestack(L, funcr); + base = func + 1; + } + else { + base = adjust_varargs(L, p, n); + func = restorestack(L, funcr); /* previous call can change stack */ + } ci = next_ci(L); /* now 'enter' new function */ ci->nresults = nresults; ci->func = func; |