Bugs
Bugs
Here is a list of all bugs found in each release of Lua since 4.0.
Each entry includes a minimal example that exhibits the bug and a patch or solution, when available. Larger fixes appear in Lua's GitHub repository, which is mirrored irregularly.Every Lua release fixes all listed bugs in previous releases, except where noted. Some bugs found in newer releases may have existed in older releases.
If you want to report a bug, please read this first.
Example:
-- In the REPL, enter something incomplete (e.g., "a.<newline>"), -- and then end-of-file (control-D on Linux) at the next prompt. > a. >> (error message not a string)
Example:
$ lua > _ENV[1 < 2] stdin:1: attempt to index a number value
Patch:
lcode.c:
@@ -985,7 985,7 @@
** or it is a constant.
*/
void luaK_exp2val (FuncState *fs, expdesc *e) {
- if (hasjumps(e))
if (e->k == VJMP || hasjumps(e))
luaK_exp2anyreg(fs, e);
else
luaK_dischargevars(fs, e);
Example:
local x = 10
Patch:
lparser.c:
@@ -198,7 198,7 @@ static int new_localvar (LexState *ls, TString *name) {
checklimit(fs, dyd->actvar.n 1 - fs->firstlocal,
MAXVARS, "local variables");
luaM_growvector(L, dyd->actvar.arr, dyd->actvar.n 1,
- dyd->actvar.size, Vardesc, USHRT_MAX, "local variables");
dyd->actvar.size, Vardesc, SHRT_MAX, "local variables");
var = &dyd->actvar.arr[dyd->actvar.n ];
var->vd.kind = VDKREG; /* default */
var->vd.name = name;
Example:
-- You must have the locale 'km_KH.UTF-8' installed
assert(os.setlocale("km_KH.UTF-8"))
local A = "\u{17A4}"
local B = "\u{17A2}\u{17B6}"
print(string.rep(B, 100000) .. "\0" <= string.rep(A, 100000) .. "\0")
Example:
/* The following program prints "Call hook: Lua" twice, while it
should print that only once. */
#include <stdio.h>
#include "lua.h"
#include "lauxlib.h"
static void hook (lua_State *L, lua_Debug *ar) {
if (ar->event == LUA_HOOKCALL) { /* call hook? */
lua_getinfo(L, "S", ar);
printf("Call hook: %s\n", ar->what);
}
else /* count hook */
lua_yield(L, 0);
}
int main (void) {
lua_State *L = luaL_newstate();
lua_State *l = lua_newthread(L);
luaL_loadstring(l, "(function(x) end)()");
lua_sethook(l, hook, LUA_MASKCOUNT | LUA_MASKCALL, 1);
int nres;
while (lua_resume(l, NULL, 0, &nres) == LUA_YIELD) { }
lua_close(L);
}
Example:
-- error should be at line 3 foo ( 0 ) --> lua: temp:2: attempt to call a nil value (global 'foo')
Example:
-- This code takes forever to run, and eventually it crashes
local a = {"local d = 1; d = d * _G"}
for i = 2, 1e7 do a[i] = "._G" end
a = table.concat(a)
a = load(a)
print(a())
Example:
a = {_ENV = {}}
print(a._ENV.x 1)
--> attempt to perform arithmetic on a nil value (global 'x')
Example:
-- segfault in 32-bit machines local a = 'Name' for b = -1000, 0 do a = a .. '____________' .. a .. '____________' .. a .. a .. '____________' end
Example:
*** yieldhook.c:
#include "lua.h"
#include "lauxlib.h"
#include "string.h"
static void hookf (lua_State *L, lua_Debug *ar) {
if (ar->currentline == 6)
lua_yield(L, 0);
}
static int db_sethook (lua_State *L) {
lua_sethook(L, hookf, LUA_MASKLINE, 0);
return 0;
}
int luaopen_yieldhook(lua_State *L) {
static luaL_Reg l[] = {
{ "sethook", db_sethook },
{ NULL, NULL },
};
luaL_checkversion(L);
luaL_newlib(L, l);
return 1;
}
*** test.lua:
local yieldhook = require 'yieldhook'
local function test()
local a1 = 1
local a2 = 2
local a3 = 3
local a4 = 4
return a1 a2 a3 a4
end
local function run()
yieldhook.sethook(coroutine.running())
return test()
end
local co = coroutine.create(run)
coroutine.resume(co)
local name
local i = 1
for i = 1, 20 do
local name, value = debug.getlocal(co, 0, i)
if name == nil then break end
i = i 1
print(name, value)
end
result:
a1 1
a2 2
--a3 3 is lost
Example:
sample = 'print("hello")'
stripped = load(string.dump(load(sample), true))
print(debug.getinfo(stripped, "L").activelines)
Example:
-- In the REPL. The "(null)" is generated by printf being called with
-- a NULL string; that is undefined behavior in ISO C.
> _PROMPT=setmetatable({}, {__tostring=error})
(null)
Example:
-- The code violates ISO C rule for assignments, but we don't know -- of any compiler where that is an issue.
Example:
-- Lua compiled with assertions on local _ENV <const> = 0 X=0
Example:
local _ = {"1","2","3","4","5","6","7","8","9","10","11","12",
"13","14","15","16","17","18","19","20","21","22","23","24","25","26",
"27","28","29","30","31","32","33","34","35","36","37","38",
"39","40","41","42","43","44","45","46","47","48","49","50",
"51","52","53","54","55","56","57","58","59","60","61","62","63","64",
"65","66","67","68","69","70","71","72","73","74","75","76","77","78",
"79","80","81","82","83","84","85","86","87","88","89","90","91","92",
"93","94","95","96","97","98","99","100","101","102","103","104",
"105","106","107","108","109","110","111","112","113","114",
"115","116","117","118","119","120","121","122","123","124",
"125","126","127","128","129","130","131","132","133","134",
"135","136","137","138","139","140","141","142","143","144",
"145","146","147","148","149","150","151","152","153","154",
"155","156","157","158","159","160","161","162","163","164",
"165","166","167","168","169","170","171","172","173","174",
"175","176","177","178","179","180","181","182","183","184",
"185","186","187","188","189","190","191","192","193","194",
"195","196","197","198","199","200","201","202","203","204",
"205","206","207","208","209","210","211","212","213","214",
"215","216","217","218","219","220","221","222","223","224",
"225","226","227","228","229","230","231","232","233","234",
"235","236","237","238","239","240","241","242","243","244",
"245","246","247","248","249","250","251","252","253","254",
"255","256", }
-- should print 3, but prints 2
print (1 | (2 or 3))
Example:
print(
xpcall((0),
function(...)
local f
if d[print(print(print(print(t[...]))))] then
end
end
)
)
Example:
-- (needs test library)
-- reduce stack size
collectgarbage(); collectgarbage(); collectgarbage()
-- force a stack reallocation
local function loop (n)
if n < 400 then loop(n 1) end
end
local o = setmetatable({}, {__close = function () loop(0) end})
local script = [[toclose 2; settop 1; return 1]]
assert(T.testC(script, o) == script)
Example:
local closed = false
local o1 = setmetatable({}, {__close=function() closed = true end})
local function test()
for k, v in next, {}, nil, o1 do
local function f() return k end -- just to use 'k'
break
end
assert(closed) -- should be closed here
end
test()
Example:
-- the following code should raise an error
for pos, cp in utf8.codes('in\xbfvalid') do
print(pos, cp)
end
Example:
-- Depending on the size of your C stack, you may need to increase the
-- limit of the loop.
local coro
for i = 1, 1e5 do
local previous = coro
coro = coroutine.create(function()
local cc <close> = setmetatable({}, {__close=function()
if previous then
assert(coroutine.close(previous))
end
end})
coroutine.yield()
end)
assert(coroutine.resume(coro))
end
print(coroutine.close(coro))
Example:
local a = 0 local b = 1 print(b // a) --> lua: temp:1: attempt to divide by zero
Example:
-- Binary files have different formats in different versions. This -- example is specific for Lua 5.4. local code = "\x1b\x4c\x75\x61\x54\x00\x19\x93\x0d\x0a\x1a\x0a\x04\x08\x08\x78\x56\z \x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x28\x77\x40\x00\x86\x40\z \x74\x65\x6d\x70\x81\x81\x01\x00\x02\x82\x48\x00\x02\x00\xc7\x00\x01\z \x00\x80\x80\x80\x82\x00\x00\x80\x81\x82\x78\x80\x82\x81\x86\x40\x74\z \x65\x6d\x70" assert(load(code))
Example:
local function iter ()
return function () return true end, 0, 0,
setmetatable({}, {__close = print})
end
local function tail() print("tail") end
local function foo ()
for k in iter() do return tail() end
end
foo()
Patch:
lvm.c:
@@ -1156,8 1156,10 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
Instruction i; /* instruction being executed */
StkId ra; /* instruction's A register */
vmfetch();
-// low-level line tracing for debugging Lua
-// printf("line: %d\n", luaG_getfuncline(cl->p, pcRel(pc, cl->p)));
#if 0
/* low-level line tracing for debugging Lua */
printf("line: %d\n", luaG_getfuncline(cl->p, pcRel(pc, cl->p)));
#endif
lua_assert(base == ci->func 1);
lua_assert(base <= L->top && L->top < L->stack_last);
/* invalidate top for instructions not expecting it */
Example:
-- The final 'print' should print nothing, as the 'print' inside 'test'
-- returns nothing.
local function test()
local x <close> = setmetatable({}, {
__close = coroutine.yield
})
return print("Return")
end
local c = coroutine.wrap(test)
c() -- runs until '__close'
print(c()) -- runs until end
Patch:
lvm.c:
@@ -847,10 847,19 @@ void luaV_finishOp (lua_State *L) {
luaV_concat(L, total); /* concat them (may yield again) */
break;
}
- case OP_CLOSE: case OP_RETURN: { /* yielded closing variables */
case OP_CLOSE: { /* yielded closing variables */
ci->u.l.savedpc--; /* repeat instruction to close other vars. */
break;
}
case OP_RETURN: { /* yielded closing variables */
StkId ra = base GETARG_A(inst);
/* correct top to signal correct number of returns (in case the
return is "in top" */
L->top = ra ci->u2.nres;
/* repeat instruction to close other vars. and complete the return */
ci->u.l.savedpc--;
break;
}
default: {
/* only these other opcodes can yield */
lua_assert(op == OP_TFORCALL || op == OP_CALL ||
@@ -1672,6 1681,7 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
n = cast_int(L->top - ra); /* get what is available */
savepc(ci);
if (TESTARG_k(i)) { /* may there be open upvalues? */
ci->u2.nres = n; /* save number of returns */
if (L->top < ci->top)
L->top = ci->top;
luaF_close(L, base, CLOSEKTOP, 1);
Example:
local x<const> = {}
function x() end -- should raise an error
print(x)
Example:
-- (must be run in interactive mode)
-- Both prints should show the same result
> debug.debug()
lua_debug> x = setmetatable({}, {__name="TABLE"})
lua_debug> print(x)
lua_debug> error(x)
Patch:
lauxlib.c:
@@ -881,6 881,7 @@ LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) {
LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
idx = lua_absindex(L,idx);
if (luaL_callmeta(L, idx, "__tostring")) { /* metafield? */
if (!lua_isstring(L, -1))
luaL_error(L, "'__tostring' must return a string");
Example:
-- Lua compiled in gcc with option '-fsanitize=undefined' print(1 >> math.mininteger)
Patch:
lvm.c:
@@ -766,7 766,7 @@ lua_Number luaV_modf (lua_State *L, lua_Number m, lua_Number n) {
/*
** Shift left operation. (Shift right just negates 'y'.)
*/
-#define luaV_shiftr(x,y) luaV_shiftl(x,-(y))
#define luaV_shiftr(x,y) luaV_shiftl(x,intop(-, 0, y))
lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y) {
if (y < 0) { /* shift right? */
Example:
local function func() pcall(1) coroutine.wrap(func)() end func()
Example:
-- Must be run with assertions on, valgrind, or sanitizer
co = coroutine.wrap(
function()
local x <close> = setmetatable(
{}, {__close = function() pcall(co) end}
)
error()
end
)
co()
Example:
-- The following chunk may segfault
function v (...)
return os.exit(0, true)
end
local x <close> = setmetatable({}, {__close = error})
v()
Example:
function func1 ()
local f = setmetatable({}, {__gc = function () collectgarbage("step") end})
collectgarbage("step" , 1)
end
for i = 0,1000 do
setmetatable({}, {__gc = func1})
end
Example:
local x = {}; for i=1, 2000 do x[i] = i end
local function f() end
local function g() return f(table.unpack(x)) end
collectgarbage("step")
setmetatable({}, {__gc = 1})
g()
Example:
-- The following code illustrates the problem. If finalizer 3 calls
-- a function from a dynamically loaded C module, the C module
-- will be closed by the time the function is called, generating
-- a segfault.
-- should be called last
print("creating 1")
setmetatable({}, {__gc = function () print(1) end})
print("creating 2")
setmetatable({}, {__gc = function ()
print("2")
print("creating 3")
setmetatable({}, {__gc = function () print(3) end})
os.exit(1, true)
end})
Example:
nan = 0/0
t = {nan, nan, 20, 10}
table.sort(t)
print(table.concat(t, ", "))
--> -nan, 20, -nan, 10
Patch: The manual is deceptive. It is necessary but not sufficient for the sort function to define a partial order.
Example:
-- with Lua compiled with option LUA_USE_APICHECK debug.getinfo(0, ">")
Patch:
ldblib.c:
@@ -152,6 152,7 @@ static int db_getinfo (lua_State *L) {
lua_State *L1 = getthread(L, &arg);
const char *options = luaL_optstring(L, arg 2, "flnSrtu");
checkstack(L, L1, 3);
luaL_argcheck(L, options[0] != '>', arg 2, "invalid option '>'");
if (lua_isfunction(L, arg 1)) { /* info about a function? */
options = lua_pushfstring(L, ">%s", options); /* add '>' to 'options' */
lua_pushvalue(L, arg 1); /* move function to 'L1' stack */
Example:
-- the following call gives an error message with a wrong index
table.concat({}, "", math.maxinteger, math.maxinteger)
Patch:
ltablib.c:
@@ -146,7 146,7 @@ static int tmove (lua_State *L) {
static void addfield (lua_State *L, luaL_Buffer *b, lua_Integer i) {
lua_geti(L, 1, i);
if (!lua_isstring(L, -1))
- luaL_error(L, "invalid value (%s) at index %d in table for 'concat'",
luaL_error(L, "invalid value (%s) at index %I in table for 'concat'",
luaL_typename(L, -1), i);
luaL_addvalue(b);
}
Example: This bug probably will not cause a failure in flat-memory architectures. We can force it by compiling Lua with the gcc option '-fsanitize=pointer-subtract' (plus what it needs to work) and running the following code:
print(setmetatable({}, {__index = 4}).x)
Example:
t = {}
t["no" .. "ref1"] = 1
t["no" .. "ref2"] = 2
for k, v in pairs(t) do
t[k] = nil
print(k, v)
collectgarbage("collect")
end
Example:
-- run this code with some memory checker, such as valgrind
-- or gcc's option -fsanitize=address
local A = {}
A[1] = false -- create an old anchor for an object
-- obj finalizer
local function gcf (obj)
A[1] = obj -- anchor object
obj = nil -- remove it from the stack
collectgarbage("step", 0) -- do a young collection
print(getmetatable(A[1]).x) -- metatable was collected!
end
collectgarbage() -- make A old
local obj = {} -- create a new object
collectgarbage("step", 0) -- make it a survival
setmetatable(obj, {__gc = gcf}) -- create its metatable
obj = nil -- clear object
collectgarbage("step", 0) -- will call obj's finalizer
Patch:
lgc.c:
@@ -1140,7 1140,7 @@ static void finishgencycle (lua_State *L, global_State *g) {
static void youngcollection (lua_State *L, global_State *g) {
GCObject **psurvival; /* to point to first non-dead survival object */
lua_assert(g->gcstate == GCSpropagate);
- markold(g, g->survival, g->reallyold);
markold(g, g->allgc, g->reallyold);
markold(g, g->finobj, g->finobjrold);
atomic(L);
Example:
local lim = 1000
local function stack (n)
if n > 0 then return stack(n - 1) 1
else coroutine.wrap(function ()
stack(lim)
end)()
end
end
print(xpcall(stack, function () return "ok" end, lim))
Patch:
ldo.c:
@@ -674,7 674,7 @@ LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
if (from == NULL)
L->nCcalls = CSTACKTHREAD;
else /* correct 'nCcalls' for this thread */
- L->nCcalls = getCcalls(from) from->nci - L->nci - CSTACKCF;
L->nCcalls = getCcalls(from) - L->nci - CSTACKCF;
if (L->nCcalls <= CSTACKERR)
return resume_error(L, "C stack overflow", nargs);
luai_userstateresume(L, nargs);
Example:
-- must compile Lua with option -DHARDMEMTESTS, to force -- emergency collections local s = string.dump(function () local x, y, z return function () return x y z end end) for i = 1, #s - 1 do assert(not load(string.sub(s, 1, i))) end
Patch:
lundump.c:
@@ -205,8 205,9 @@ static void loadUpvalues (LoadState *S, Proto *f) {
n = loadInt(S);
f->upvalues = luaM_newvectorchecked(S->L, n, Upvaldesc);
f->sizeupvalues = n;
- for (i = 0; i < n; i ) {
for (i = 0; i < n; i )
f->upvalues[i].name = NULL;
for (i = 0; i < n; i ) {
f->upvalues[i].instack = loadByte(S);
f->upvalues[i].idx = loadByte(S);
f->upvalues[i].kind = loadByte(S);
Example: See http://lua-users.org/lists/lua-l/2020-07/msg00053.html.
Patch:
ldo.c:
@@ -466,13 466,13 @@ void luaD_call (lua_State *L, StkId func, int nresults) {
f = fvalue(s2v(func));
Cfunc: {
int n; /* number of returns */
- CallInfo *ci = next_ci(L);
CallInfo *ci;
checkstackp(L, LUA_MINSTACK, func); /* ensure minimum stack size */
L->ci = ci = next_ci(L);
ci->nresults = nresults;
ci->callstatus = CIST_C;
ci->top = L->top LUA_MINSTACK;
ci->func = func;
- L->ci = ci;
lua_assert(ci->top <= L->stack_last);
if (L->hookmask & LUA_MASKCALL) {
int narg = cast_int(L->top - func) - 1;
@@ -486,18 486,18 @@ void luaD_call (lua_State *L, StkId func, int nresults) {
break;
}
case LUA_VLCL: { /* Lua function */
- CallInfo *ci = next_ci(L);
CallInfo *ci;
Proto *p = clLvalue(s2v(func))->p;
int narg = cast_int(L->top - func) - 1; /* number of real arguments */
int nfixparams = p->numparams;
int fsize = p->maxstacksize; /* frame size */
checkstackp(L, fsize, func);
L->ci = ci = next_ci(L);
ci->nresults = nresults;
ci->u.l.savedpc = p->code; /* starting point */
ci->callstatus = 0;
ci->top = func 1 fsize;
ci->func = func;
- L->ci = ci;
for (; narg < nfixparams; narg )
setnilvalue(s2v(L->top )); /* complete missing arguments */
lua_assert(ci->top <= L->stack_last);
Example: See http://lua-users.org/lists/lua-l/2020-07/msg00054.html.
Patch:
ldo.h:
@@ -44,7 44,7 @@
/* macro to check stack size and GC */
#define checkstackGC(L,fsize) \
- luaD_checkstackaux(L, (fsize), (void)0, luaC_checkGC(L))
luaD_checkstackaux(L, (fsize), luaC_checkGC(L), (void)0)
/* type of protected functions, to be ran by 'runprotected' */
Example: http://lua-users.org/lists/lua-l/2020-07/msg00078.html.
Patch:
lvm.c:
@@ -1104,7 1104,7 @@ void luaV_finishOp (lua_State *L) {
#define checkGC(L,c) \
- { luaC_condGC(L, L->top = (c), /* limit of live values */ \
{ luaC_condGC(L, (savepc(L), L->top = (c)), \
updatetrap(ci)); \
luai_threadyield(L); }
@@ -1792,8 1792,7 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
vmbreak;
}
vmcase(OP_VARARGPREP) {
- luaT_adjustvarargs(L, GETARG_A(i), ci, cl->p);
- updatetrap(ci);
ProtectNT(luaT_adjustvarargs(L, GETARG_A(i), ci, cl->p));
if (trap) {
luaD_hookcall(L, ci);
L->oldpc = pc 1; /* next opcode will be seen as a "new" line */
Example: (system dependent)
Patch:
liolib.c:
@@ -279,6 279,8 @@ static int io_popen (lua_State *L) {
const char *filename = luaL_checkstring(L, 1);
const char *mode = luaL_optstring(L, 2, "r");
LStream *p = newprefile(L);
luaL_argcheck(L, ((mode[0] == 'r' || mode[0] == 'w') && mode[1] == '\0'),
2, "invalid mode");
p->f = l_popen(L, filename, mode);
p->closef = &io_pclose;
return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
Example:
-- run this code under valgrind. (Error depends on details of dynamic
-- addresses.)
function foo ()
local f = load[[io.write(' ');
for i = 1, 10000 do local a = {}; debug.sethook(nil) end
io.write'-']]
local u = setmetatable({},
{__gc = assert(load[[debug.sethook(print, "l");
error('err');
]])})
u = nil
f()
end
for i = 1, 200 do
foo()
end
Patch:
lgc.c:
@@ -856,6 856,8 @@ static void GCTM (lua_State *L) {
if (unlikely(status != LUA_OK)) { /* error while running __gc? */
luaE_warnerror(L, "__gc metamethod");
L->top--; /* pops error object */
if (isLua(L->ci))
L->oldpc = L->ci->u.l.savedpc; /* update 'oldpc' */
}
}
}
Example:
function errfunc () return 10 xpcall(nil, errfunc) end coroutine.resume(coroutine.create(function() xpcall(nil, errfunc) end))
Example:
-- The following chunk, under a memory checker like valgrind,
-- produces a memory access violation.
local old = {10}
collectgarbage() -- make 'old' old
local co = coroutine.create(
function ()
local x = nil
local f = function ()
return x[1]
end
x = coroutine.yield(f)
coroutine.yield()
end
)
local _, f = coroutine.resume(co) -- create closure over x in thread
collectgarbage("step", 0) -- make upvalue a survival
old[1] = {"hello"} -- 'old' go to grayagain as 'touched1'
coroutine.resume(co, {123}) -- its value will be new
co = nil
-- next minor collection hits the barrier between upvalue and its
-- conent while sweeping the thread. This will mix the lists 'gray'
-- and 'grayagain' and will remove 'old' from 'grayagain'.
collectgarbage("step", 0)
assert(f() == 123 and old[1][1] == "hello") -- still ok
collectgarbage("step", 0) -- run the collector once more
-- now, as 'old' was not in 'grayagain', 'old[1]' was deleted
assert(f() == 123 and old[1][1] == "hello")
Example:
print(debug.getlocal(1, 2^31))
Example:
local function foo () local a = 1 local b = 2 local c = 3 end local s = load(string.dump(foo, true)) local line debug.sethook(function (e, l) line = l end, "l"); s(); debug.sethook(nil) print(line)
Example:
-- run this code under some memory checker
local function myload (s)
return load(function ()
if s == "" then return nil
else
local c = string.sub(s, 1, 1)
s = string.sub(s, 2)
collectgarbage()
return c
end
end)
end
local y = string.dump(function ()
return '01234567890123456789012345678901234567890123456789'
end)
y = myload(y)
assert(y() == '01234567890123456789012345678901234567890123456789')
That was the last release of Lua 5.3. Bugs reported later are most probably fixed in Lua 5.4.
Patch:
src/Makefile: @@ -104,2 104,2 @@ freebsd: - $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_LINUX -DLUA_USE_READLINE -I/usr/include/edit" SYSLIBS="-Wl,-E -ledit" CC="cc" $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_LINUX -I/usr/include/edit" SYSLIBS="-Wl,-E -ledit" CC="cc"
Patch:
Makefile: @@ -49 49 @@ -R= $V.4 R= $V.5
Example:
local eqs = string.rep("=", 0x3ffffffe)
local code = "return [" .. eqs .. "[a]" .. eqs .. "]"
print(#assert(load(code))())
Example:
-- the next code may crash the machine
f=load(function() end)
interesting={}
interesting[0]=string.rep("A",512)
debug.upvaluejoin(f,1,f,1)
Patch:
lapi.c:
@@ -1289,6 1289,8 @@
LUA_API void lua_upvaluejoin (lua_State *L, int fidx1, int n1,
LClosure *f1;
UpVal **up1 = getupvalref(L, fidx1, n1, &f1);
UpVal **up2 = getupvalref(L, fidx2, n2, NULL);
if (*up1 == *up2)
return;
luaC_upvdeccount(L, *up1);
*up1 = *up2;
(*up1)->refcount ;
Example:
-- should print 32323232..., but prints only '3' if true then goto LBL ::loop:: print(2) ::LBL:: print(3) goto loop end
Patch:
lparser.c:
@@ -1392,7 1392,7 @@
luaK_goiffalse(ls->fs, &v); /* will jump to label if condition is true */
enterblock(fs, &bl, 0); /* must enter block before 'goto' */
gotostat(ls, v.t); /* handle goto/break */
- skipnoopstat(ls); /* skip other no-op statements */
while (testnext(ls, ';')) {} /* skip semicolons */
if (block_follow(ls, 0)) { /* 'goto' is the entire block? */
leaveblock(fs);
return; /* and that is it */
Example:
-- crashes if machine has enough memory
local t = {}
for i = 1, 0x7fffffff do
t[i] = i
end
Patch:
ltable.c:
@@ -223,7 223,9 @@
unsigned int na = 0; /* number of elements to go to array part */
unsigned int optimal = 0; /* optimal size for array part */
/* loop while keys can fill more than half of total size */
- for (i = 0, twotoi = 1; *pna > twotoi / 2; i , twotoi *= 2) {
for (i = 0, twotoi = 1;
twotoi > 0 && *pna > twotoi / 2;
i , twotoi *= 2) {
if (nums[i] > 0) {
a = nums[i];
if (a > twotoi/2) { /* more than half elements present? */
Example:
-- on a machine with enough memory
local t = {}
for i = 1, 2147483681 do
t[i] = i
end
print(#t)
Patch:
ltable.h:
@@ -56,3 56,3 @@
LUAI_FUNC int luaH_next (lua_State *L, Table *t, StkId key);
-LUAI_FUNC int luaH_getn (Table *t);
LUAI_FUNC lua_Unsigned luaH_getn (Table *t);
ltable.c:
@@ -614,4 614,4 @@
-static int unbound_search (Table *t, unsigned int j) {
- unsigned int i = j; /* i is zero or a present index */
static lua_Unsigned unbound_search (Table *t, lua_Unsigned j) {
lua_Unsigned i = j; /* i is zero or a present index */
j ;
@@ -620,3 620,3 @@
i = j;
- if (j > cast(unsigned int, MAX_INT)/2) { /* overflow? */
if (j > l_castS2U(LUA_MAXINTEGER) / 2) { /* overflow? */
/* table was built with bad purposes: resort to linear search */
@@ -630,3 630,3 @@
while (j - i > 1) {
- unsigned int m = (i j)/2;
lua_Unsigned m = (i j)/2;
if (ttisnil(luaH_getint(t, m))) j = m;
@@ -642,3 642,3 @@
*/
-int luaH_getn (Table *t) {
lua_Unsigned luaH_getn (Table *t) {
unsigned int j = t->sizearray;
Example:
function test()
bob.joe.larry = 23
end
-- memory will grow steadly
for i = 1, math.huge do
pcall(test)
if i % 100000 == 0 then
io.write(collectgarbage'count'*1024, "\n")
end
end
Patch:
ldebug.c: @@ -653,6 653,7 @@ CallInfo *ci = L->ci; const char *msg; va_list argp; luaC_checkGC(L); /* error message uses memory */ va_start(argp, fmt); msg = luaO_pushvfstring(L, fmt, argp); /* format message */ va_end(argp);
Example:
-- The following chunk, under a memory checker like valgrind, produces a memory access violation.
local a = setmetatable({}, {__mode = 'kv'})
a['ABCDEFGHIJKLMNOPQRSTUVWXYZ' .. 'abcdefghijklmnopqrstuvwxyz'] = {}
a[next(a)] = nil
collectgarbage()
print(a['BCDEFGHIJKLMNOPQRSTUVWXYZ' .. 'abcdefghijklmnopqrstuvwxyz'])
Patch:
lgc.c:
@@ -643,8 643,9 @@
for (n = gnode(h, 0); n < limit; n ) {
if (!ttisnil(gval(n)) && (iscleared(g, gkey(n)))) {
setnilvalue(gval(n)); /* remove value ... */
- removeentry(n); /* and remove entry from table */
}
if (ttisnil(gval(n))) /* is entry empty? */
removeentry(n); /* remove entry from table */
}
}
}
lua_pushcclosure should not call the garbage collector when
n is zero.
Patch:
lapi.c:
@@ -533,6 533,7 @@
lua_lock(L);
if (n == 0) {
setfvalue(L->top, fn);
api_incr_top(L);
}
else {
CClosure *cl;
@@ -546,9 547,9 @@
/* does not need barrier because closure is white */
}
setclCvalue(L, L->top, cl);
api_incr_top(L);
luaC_checkGC(L);
}
- api_incr_top(L);
- luaC_checkGC(L);
lua_unlock(L);
}
Example:
local a = {x = 1, y = 1, z = 1}
a[1] = 10 -- goes to the hash part (which has 4 slots)
print(a[1]) --> 10
-- assume that the 2nd memory allocation from now fails
pcall(rawset, a, 2, 20) -- forces a rehash
-- a[1] now exists both in the array part (because the array part
-- grew) and in the hash part (because the allocation of the hash
-- part failed, keeping it as it was).
-- This makes the following traversal goes forever...
for k,v in pairs(a) do print(k,v) end
Patch:
ltable.c:
@@ -332,17 332,34 @@
}
typedef struct {
Table *t;
unsigned int nhsize;
} AuxsetnodeT;
static void auxsetnode (lua_State *L, void *ud) {
AuxsetnodeT *asn = cast(AuxsetnodeT *, ud);
setnodevector(L, asn->t, asn->nhsize);
}
void luaH_resize (lua_State *L, Table *t, unsigned int nasize,
unsigned int nhsize) {
unsigned int i;
int j;
AuxsetnodeT asn;
unsigned int oldasize = t->sizearray;
int oldhsize = allocsizenode(t);
Node *nold = t->node; /* save old hash ... */
if (nasize > oldasize) /* array part must grow? */
setarrayvector(L, t, nasize);
/* create new hash part with appropriate size */
- setnodevector(L, t, nhsize);
asn.t = t; asn.nhsize = nhsize;
if (luaD_rawrunprotected(L, auxsetnode, &asn) != LUA_OK) { /* mem. error? */
setarrayvector(L, t, oldasize); /* array back to its original size */
luaD_throw(L, LUA_ERRMEM); /* rethrow memory error */
}
if (nasize < oldasize) { /* array part must shrink? */
t->sizearray = nasize;
/* re-insert elements from vanishing slice */
Example:
-- the next loop will probably crash the interpreter repeat until load "for _ in _,_,_,_ do local function _() end"
Patch:
lparser.c:
@@ -323,6 323,8 @@
luaK_nil(fs, reg, extra);
}
}
if (nexps > nvars)
ls->fs->freereg -= nexps - nvars; /* remove extra values */
}
@@ -1160,11 1162,8 @@
int nexps;
checknext(ls, '=');
nexps = explist(ls, &e);
- if (nexps != nvars) {
if (nexps != nvars)
adjust_assign(ls, nvars, nexps, &e);
- if (nexps > nvars)
- ls->fs->freereg -= nexps - nvars; /* remove extra values */
- }
else {
luaK_setoneret(ls->fs, &e); /* close last expression */
luaK_storevar(ls->fs, &lh->v, &e);
os.date may read pass the format string.
Example: This bug does not seem to happen with regular compilers. It needs an "interceptor" 'memcmp' function that continues reading memory after a difference is found.
Patch:
loslib.c:
263c263,264
< for (option = LUA_STRFTIMEOPTIONS; *option != '\0'; option = oplen) {
---
> int convlen = (int)strlen(conv);
> for (option = LUA_STRFTIMEOPTIONS; *option != '\0' && oplen <= convlen; option = oplen) {
Example: See http://lua-users.org/lists/lua-l/2016-07/msg00303.html.
Patch:
lcode.c:
@@ -1018,8 1018,8 @@
*/
static void codebinexpval (FuncState *fs, OpCode op,
expdesc *e1, expdesc *e2, int line) {
- int rk1 = luaK_exp2RK(fs, e1); /* both operands are "RK" */
- int rk2 = luaK_exp2RK(fs, e2);
int rk2 = luaK_exp2RK(fs, e2); /* both operands are "RK" */
int rk1 = luaK_exp2RK(fs, e1);
freeexps(fs, e1, e2);
e1->u.info = luaK_codeABC(fs, op, 0, rk1, rk2); /* generate opcode */
e1->k = VRELOCABLE; /* all those operations are relocatable */
Example:
-- with C assertions on A = coroutine.running() B = coroutine.create(function() coroutine.resume(A) end) coroutine.resume(B) -- or A = coroutine.wrap(function() pcall(A, _) end) A()
Example:
local mt = {}
mt.__newindex = mt
local t = setmetatable({}, mt)
t[1] = 1 -- will segfault on some machines
Patch:
lvm.c:
@@ -190,18 190,19 @@
for (loop = 0; loop < MAXTAGLOOP; loop ) {
const TValue *tm;
if (oldval != NULL) {
- lua_assert(ttistable(t) && ttisnil(oldval));
Table *h = hvalue(t); /* save 't' table */
lua_assert(ttisnil(oldval));
/* must check the metamethod */
- if ((tm = fasttm(L, hvalue(t)->metatable, TM_NEWINDEX)) == NULL &&
if ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL &&
/* no metamethod; is there a previous entry in the table? */
(oldval != luaO_nilobject ||
/* no previous entry; must create one. (The next test is
always true; we only need the assignment.) */
- (oldval = luaH_newkey(L, hvalue(t), key), 1))) {
(oldval = luaH_newkey(L, h, key), 1))) {
/* no metamethod and (now) there is an entry with given key */
setobj2t(L, cast(TValue *, oldval), val);
- invalidateTMcache(hvalue(t));
- luaC_barrierback(L, hvalue(t), val);
invalidateTMcache(h);
luaC_barrierback(L, h, val);
return;
}
/* else will try the metamethod */
Example:
do local k = 0 local x ::foo:: local y -- should be reset to nil after goto, but it is not assert(not y) y = true k = k 1 if k < 2 then goto foo end end
Patch:
lparser.c:
@@ -1226,7 1226,7 @@
checkrepeated(fs, ll, label); /* check for repeated labels */
checknext(ls, TK_DBCOLON); /* skip double colon */
/* create new entry for this label */
- l = newlabelentry(ls, ll, label, line, fs->pc);
l = newlabelentry(ls, ll, label, line, luaK_getlabel(fs));
skipnoopstat(ls); /* skip other no-op statements */
if (block_follow(ls, 0)) { /* label is last no-op statement in the block? */
/* assume that locals are already out of scope */
gmatch iterator fails when called from a coroutine different from the one that created it.
Example:
local f = string.gmatch("1 2 3 4 5", "%d ")
print(f()) --> 1
co = coroutine.wrap(f)
print(co()) --> ??? (should be 2)
Patch:
lstrlib.c:
@@ -688,6 688,7 @@
static int gmatch_aux (lua_State *L) {
GMatchState *gm = (GMatchState *)lua_touserdata(L, lua_upvalueindex(3));
const char *src;
gm->ms.L = L;
for (src = gm->src; src <= gm->ms.src_end; src ) {
const char *e;
reprepstate(&gm->ms);
io.lines does not check maximum number of options.
Example:
-- can crash in some machines
t ={}; for i = 1, 253 do t[i] = 1 end
io.lines("someexistingfile", table.unpack(t))()
Patch:
liolib.c:
@@ -318,8 318,15 @@
static int io_readline (lua_State *L);
/*
** maximum number of arguments to 'f:lines'/'io.lines' (it 3 must fit
** in the limit for upvalues of a closure)
*/
#define MAXARGLINE 250
static void aux_lines (lua_State *L, int toclose) {
int n = lua_gettop(L) - 1; /* number of arguments to read */
luaL_argcheck(L, n <= MAXARGLINE, MAXARGLINE 2, "too many arguments");
lua_pushinteger(L, n); /* number of arguments to read */
lua_pushboolean(L, toclose); /* close/not close file when finished */
lua_rotate(L, 2, 2); /* move 'n' and 'toclose' to their positions */
string.format("%f") can cause a buffer overflow
(only when 'lua_Number' is long double!).
Example:
string.format("%.99f", 1e4000) -- when floats are long double
Patch:
lstrlib.c:
@@ -800,3 800,4 @@
/* maximum size of each formatted item (> len(format('�.99f', -1e308))) */
-#define MAX_ITEM 512
#define MAX_ITEM \
(sizeof(lua_Number) <= 4 ? 150 : sizeof(lua_Number) <= 8 ? 450 : 5050)
debug.getlocal on a coroutine suspended in a hook
can crash the interpreter.
Example: See http://lua-users.org/lists/lua-l/2015-02/msg00146.html.
Patch:
ldebug.c:
@@ -49,4 49,14 @@
static void swapextra (lua_State *L) {
if (L->status == LUA_YIELD) {
CallInfo *ci = L->ci; /* get function that yielded */
StkId temp = ci->func; /* exchange its 'func' and 'extra' values */
ci->func = restorestack(L, ci->extra);
ci->extra = savestack(L, temp);
}
}
/*
** this function can be called asynchronous (e.g. during a signal)
@@ -145,4 155,5 @@
const char *name;
lua_lock(L);
swapextra(L);
if (ar == NULL) { /* information about non-active function? */
if (!isLfunction(L->top - 1)) /* not a Lua function? */
@@ -159,4 170,5 @@
}
}
swapextra(L);
lua_unlock(L);
return name;
@@ -166,10 178,13 @@
LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
StkId pos = 0; /* to avoid warnings */
- const char *name = findlocal(L, ar->i_ci, n, &pos);
const char *name;
lua_lock(L);
swapextra(L);
name = findlocal(L, ar->i_ci, n, &pos);
if (name) {
setobjs2s(L, pos, L->top - 1);
L->top--; /* pop value */
}
swapextra(L);
lua_unlock(L);
return name;
@@ -271,4 286,5 @@
StkId func;
lua_lock(L);
swapextra(L);
if (*what == '>') {
ci = NULL;
@@ -289,4 305,5 @@
api_incr_top(L);
}
swapextra(L);
if (strchr(what, 'L'))
collectvalidlines(L, cl);
Example:
mt = {__le = function (a,b) coroutine.yield("yield"); return a.x <= b.x end}
t1 = setmetatable({x=1}, mt)
t2 = {x=2}
co = coroutine.wrap(function (a,b) return t2 <= t1 end)
co()
print(co()) --> true (should be false)
Patch:
lstate.h:
@@ -94,6 94,7 @@
#define CIST_YPCALL (1<<4) /* call is a yieldable protected call */
#define CIST_TAIL (1<<5) /* call was tail called */
#define CIST_HOOKYIELD (1<<6) /* last hook called yielded */
#define CIST_LEQ (1<<7) /* using __lt for __le */
#define isLua(ci) ((ci)->callstatus & CIST_LUA)
lvm.c:
@@ -292,9 292,14 @@
return l_strcmp(tsvalue(l), tsvalue(r)) <= 0;
else if ((res = luaT_callorderTM(L, l, r, TM_LE)) >= 0) /* first try 'le' */
return res;
- else if ((res = luaT_callorderTM(L, r, l, TM_LT)) < 0) /* else try 'lt' */
- luaG_ordererror(L, l, r);
- return !res;
else { /* try 'lt': */
L->ci->callstatus |= CIST_LEQ; /* mark it is doing 'lt' for 'le' */
res = luaT_callorderTM(L, r, l, TM_LT);
L->ci->callstatus ^= CIST_LEQ; /* clear mark */
if (res < 0)
luaG_ordererror(L, l, r);
return !res; /* result is negated */
}
}
@@ -553,11 558,11 @@
case OP_LE: case OP_LT: case OP_EQ: {
int res = !l_isfalse(L->top - 1);
L->top--;
- /* metamethod should not be called when operand is K */
- lua_assert(!ISK(GETARG_B(inst)));
- if (op == OP_LE && /* "<=" using "<" instead? */
- ttisnil(luaT_gettmbyobj(L, base GETARG_B(inst), TM_LE)))
- res = !res; /* invert result */
if (ci->callstatus & CIST_LEQ) { /* "<=" using "<" instead? */
lua_assert(op == OP_LE);
ci->callstatus ^= CIST_LEQ; /* clear mark */
res = !res; /* negate result */
}
lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP);
if (res != GETARG_A(inst)) /* condition failed? */
ci->u.l.savedpc ; /* skip jump instruction */
Example: See http://lua-users.org/lists/lua-l/2015-05/msg00376.html.
That was the last release of Lua 5.2. Bugs reported later are most probably fixed in Lua 5.3.
table.unpack.
Example:
unpack({}, 0, 2^31 - 1) -- crashes on some platforms with some compiler options
Patch:
ltablib.c:
@@ -134,13 135,14 @@
static int unpack (lua_State *L) {
- int i, e, n;
int i, e;
unsigned int n;
luaL_checktype(L, 1, LUA_TTABLE);
i = luaL_optint(L, 2, 1);
e = luaL_opt(L, luaL_checkint, 3, luaL_len(L, 1));
if (i > e) return 0; /* empty range */
- n = e - i 1; /* number of elements */
- if (n <= 0 || !lua_checkstack(L, n)) /* n <= 0 means arith. overflow */
n = (unsigned int)e - (unsigned int)i; /* number of elements minus 1 */
if (n > (INT_MAX - 10) || !lua_checkstack(L, n))
return luaL_error(L, "too many results to unpack");
lua_rawgeti(L, 1, i); /* push arg[i] (avoiding overflow problems) */
while (i < e) /* push arg[i 1...e] */
Example: This bug is very hard to reproduce, because it depends on a specific interleaving of events between the incremental collector and the program.
Patch:
lgc.c:
@@ -403,7 403,7 @@
reallymarkobject(g, gcvalue(gval(n))); /* mark it now */
}
}
- if (prop)
if (g->gcstate != GCSatomic || prop)
linktable(h, &g->ephemeron); /* have to propagate again */
else if (hasclears) /* does table have white keys? */
linktable(h, &g->allweak); /* may have to clean white keys */
Example: The cause of the bug is the use of an unitialized variable, so it cannot be reproduced reliably.
local s = string.rep("\n", 2^24)
print(load(function () return s end))
Patch:
llex.c:
@@ -153,5 153,5 @@
next(ls); /* skip `\n\r' or `\r\n' */
if ( ls->linenumber >= MAX_INT)
- luaX_syntaxerror(ls, "chunk has too many lines");
lexerror(ls, "chunk has too many lines", 0);
}
Example:
function f(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10,
p11, p12, p13, p14, p15, p16, p17, p18, p19, p20,
p21, p22, p23, p24, p25, p26, p27, p28, p29, p30,
p31, p32, p33, p34, p35, p36, p37, p38, p39, p40,
p41, p42, p43, p44, p45, p46, p48, p49, p50, ...)
local a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14
end
f() -- crashes on some machines
Patch:
ldo.c:
@@ -324,7 324,7 @@
case LUA_TLCL: { /* Lua function: prepare its call */
StkId base;
Proto *p = clLvalue(func)->p;
- luaD_checkstack(L, p->maxstacksize);
luaD_checkstack(L, p->maxstacksize p->numparams);
func = restorestack(L, funcr);
n = cast_int(L->top - func) - 1; /* number of real arguments */
for (; n < p->numparams; n )
Example:
function f() f() end f() -- it takes too long before a "stack overflow" error
Patch:
lgc.c:
@@ -495,2 495,3 @@
static lu_mem traversestack (global_State *g, lua_State *th) {
int n = 0;
StkId o = th->stack;
@@ -505,3 506,9 @@
}
- return sizeof(lua_State) sizeof(TValue) * th->stacksize;
else { /* count call infos to compute size */
CallInfo *ci;
for (ci = &th->base_ci; ci != th->ci; ci = ci->next)
n ;
}
return sizeof(lua_State) sizeof(TValue) * th->stacksize
sizeof(CallInfo) * n;
}
Example:
-- only with Lua compiled in debug mode
print({} .. 2)
Patch:
ldebug.c:
@@ -519,5 519,5 @@
l_noret luaG_concaterror (lua_State *L, StkId p1, StkId p2) {
if (ttisstring(p1) || ttisnumber(p1)) p1 = p2;
- lua_assert(!ttisstring(p1) && !ttisnumber(p2));
lua_assert(!ttisstring(p1) && !ttisnumber(p1));
luaG_typeerror(L, p1, "concatenate");
}
Example:
a,b,c = true,true,true
(a and b or c)('', '')
--> stdin:1: attempt to call a boolean value (global 'c')
-- it should be global 'b' instead of 'c'
Patch:
ldebug.c:
@@ -327,12 327,20 @@
}
static int filterpc (int pc, int jmptarget) {
if (pc < jmptarget) /* is code conditional (inside a jump)? */
return -1; /* cannot know who sets that register */
else return pc; /* current position sets that register */
}
/*
** try to find last instruction before 'lastpc' that modified register 'reg'
*/
static int findsetreg (Proto *p, int lastpc, int reg) {
int pc;
int setreg = -1; /* keep last instruction that changed 'reg' */
int jmptarget = 0; /* any code before this address is conditional */
for (pc = 0; pc < lastpc; pc ) {
Instruction i = p->code[pc];
OpCode op = GET_OPCODE(i);
@@ -341,33 349,38 @@
case OP_LOADNIL: {
int b = GETARG_B(i);
if (a <= reg && reg <= a b) /* set registers from 'a' to 'a b' */
- setreg = pc;
setreg = filterpc(pc, jmptarget);
break;
}
case OP_TFORCALL: {
- if (reg >= a 2) setreg = pc; /* affect all regs above its base */
if (reg >= a 2) /* affect all regs above its base */
setreg = filterpc(pc, jmptarget);
break;
}
case OP_CALL:
case OP_TAILCALL: {
- if (reg >= a) setreg = pc; /* affect all registers above base */
if (reg >= a) /* affect all registers above base */
setreg = filterpc(pc, jmptarget);
break;
}
case OP_JMP: {
int b = GETARG_sBx(i);
int dest = pc 1 b;
/* jump is forward and do not skip `lastpc'? */
- if (pc < dest && dest <= lastpc)
- pc = b; /* do the jump */
if (pc < dest && dest <= lastpc) {
if (dest > jmptarget)
jmptarget = dest; /* update 'jmptarget' */
}
break;
}
case OP_TEST: {
- if (reg == a) setreg = pc; /* jumped code can change 'a' */
if (reg == a) /* jumped code can change 'a' */
setreg = filterpc(pc, jmptarget);
break;
}
default:
if (testAMode(op) && reg == a) /* any instruction that set A */
- setreg = pc;
setreg = filterpc(pc, jmptarget);
break;
}
}
Example:
-- When you call 'luac -l' over this chunk, it chokes the output s="Lorem ipsum dolor sit amet, consectetur, "
Patch:
luac.c:
@@ -251,7 251,7 @@
static void PrintConstant(const Proto* f, int i)
{
const TValue* o=&f->k[i];
- switch (ttype(o))
switch (ttypenv(o))
{
case LUA_TNIL:
printf("nil");
Example: This bug is very difficult to happen (and to reproduce), because it depends on the GC running in a very specific way when parsing a source code with long (larger than 40 characters) identifiers.
Patch:
ltable.h:
@@ -18,4 18,8 @@
#define invalidateTMcache(t) ((t)->flags = 0)
/* returns the key, given the value of a table entry */
#define keyfromval(v) \
(gkey(cast(Node *, cast(char *, (v)) - offsetof(Node, i_val))))
LUAI_FUNC const TValue *luaH_getint (Table *t, int key);
llex.c:
@@ -134,4 134,7 @@
luaC_checkGC(L);
}
else { /* string already present */
ts = rawtsvalue(keyfromval(o)); /* re-use value previously stored */
}
L->top--; /* remove string from stack */
return ts;
luai_userstateclose should be done only
after the calls to __gc methods.
Patch:
lstate.c:
@@ -194,2 194,4 @@
g->gcrunning = 1; /* allow gc */
g->version = lua_version(NULL);
luai_userstateopen(L);
}
@@ -224,2 226,4 @@
luaC_freeallobjects(L); /* collect all objects */
if (g->version) /* closing a fully built state? */
luai_userstateclose(L);
luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size);
@@ -289,3 293,3 @@
g->panic = NULL;
- g->version = lua_version(NULL);
g->version = NULL;
g->gcstate = GCSpause;
@@ -308,4 312,2 @@
}
- else
- luai_userstateopen(L);
return L;
@@ -317,3 319,2 @@
lua_lock(L);
- luai_userstateclose(L);
close_state(L);
Example:
-- should print 'true' print(coroutine.resume(coroutine.create(function() coroutine.resume(coroutine.running()) coroutine.yield() end)))
Patch:
ldo.c: @@ -536,2 536,3 @@ int status; int oldnny = L->nny; /* save 'nny' */ lua_lock(L); @@ -557,3 558,3 @@ } - L->nny = 1; /* do not allow yields */ L->nny = oldnny; /* restore 'nny' */ L->nCcalls--;
Example:
print(string.find(string.rep("a", 2^20), string.rep(".?", 2^20)))
pcall may not restore previous error function when
inside coroutines.
Example:
function errfunc(x)
return 'errfunc'
end
function test(do_yield)
print(do_yield and "yielding" or "not yielding")
pcall(function() -- this pcall sets errfunc back to none
if do_yield then
coroutine.yield() -- stops errfunc from being restored
end
end)
error('fail!')
end
coro = coroutine.wrap(function()
print(xpcall(test, errfunc, false))
print(xpcall(test, errfunc, true))
print(xpcall(test, errfunc, false))
end)
coro()
--> not yielding
--> false errfunc
--> yielding
coro()
--> false temp:12: fail! <<<< should be 'errfunc' too
--> not yielding
--> false errfunc
Patch:
ldo.c:
@@ -403,7 403,11 @@
int n;
lua_assert(ci->u.c.k != NULL); /* must have a continuation */
lua_assert(L->nny == 0);
- /* finish 'lua_callk' */
if (ci->callstatus & CIST_YPCALL) { /* was inside a pcall? */
ci->callstatus &= ~CIST_YPCALL; /* finish 'lua_pcall' */
L->errfunc = ci->u.c.old_errfunc;
}
/* finish 'lua_callk'/'lua_pcall' */
adjustresults(L, ci->nresults);
/* call continuation function */
if (!(ci->callstatus & CIST_STAT)) /* no call status? */
Example: See http://lua-users.org/lists/lua-l/2012-08/msg00149.html.
Patch:
ldo.c:
@@ -311,6 311,7 @@
ci->top = L->top LUA_MINSTACK;
lua_assert(ci->top <= L->stack_last);
ci->callstatus = 0;
luaC_checkGC(L); /* stack grow uses memory */
if (L->hookmask & LUA_MASKCALL)
luaD_hook(L, LUA_HOOKCALL, -1);
lua_unlock(L);
@@ -338,6 339,7 @@
ci->u.l.savedpc = p->code; /* starting point */
ci->callstatus = CIST_LUA;
L->top = ci->top;
luaC_checkGC(L); /* stack grow uses memory */
if (L->hookmask & LUA_MASKCALL)
callhook(L, ci);
return 0;
@@ -393,7 395,6 @@
luaV_execute(L); /* call it */
if (!allowyield) L->nny--;
L->nCcalls--;
- luaC_checkGC(L);
}
load and loadfile return wrong result when given an environment
for a binary chunk with no upvalues.
Example:
f = load(string.dump(function () return 1 end), nil, "b", {})
print(type(f)) --> table (should be function)
Patch:
lbaselib.c:
@@ -244,5 244,11 @@
-static int load_aux (lua_State *L, int status) {
- if (status == LUA_OK)
static int load_aux (lua_State *L, int status, int envidx) {
if (status == LUA_OK) {
if (envidx != 0) { /* 'env' parameter? */
lua_pushvalue(L, envidx); /* environment for loaded function */
if (!lua_setupvalue(L, -2, 1)) /* set it as 1st upvalue */
lua_pop(L, 1); /* remove 'env' if not used by previous call */
}
return 1;
}
else {
@@ -258,9 264,5 @@
const char *mode = luaL_optstring(L, 2, NULL);
- int env = !lua_isnone(L, 3); /* 'env' parameter? */
int env = (!lua_isnone(L, 3) ? 3 : 0); /* 'env' index or 0 if no 'env' */
int status = luaL_loadfilex(L, fname, mode);
- if (status == LUA_OK && env) { /* 'env' parameter? */
- lua_pushvalue(L, 3);
- lua_setupvalue(L, -2, 1); /* set it as 1st upvalue of loaded chunk */
- }
- return load_aux(L, status);
return load_aux(L, status, env);
}
@@ -309,5 311,5 @@
size_t l;
- int top = lua_gettop(L);
const char *s = lua_tolstring(L, 1, &l);
const char *mode = luaL_optstring(L, 3, "bt");
int env = (!lua_isnone(L, 4) ? 4 : 0); /* 'env' index or 0 if no 'env' */
if (s != NULL) { /* loading a string? */
@@ -322,7 324,3 @@
}
- if (status == LUA_OK && top >= 4) { /* is there an 'env' argument */
- lua_pushvalue(L, 4); /* environment for loaded function */
- lua_setupvalue(L, -2, 1); /* set it as 1st upvalue */
- }
- return load_aux(L, status);
return load_aux(L, status, env);
}
Example:
collectgarbage(); print(collectgarbage'count' * 1024)
for i = 1, 100 do
local co = coroutine.create(function () end)
local x = {}
for j=1,1000 do x[j] = j end
debug.sethook(co, function () return x end, 'l')
end
collectgarbage(); print(collectgarbage'count' * 1024)
-- value should back to near the original level
Patch:
ldblib.c:
@@ -253,14 253,15 @@
}
-#define gethooktable(L) luaL_getsubtable(L, LUA_REGISTRYINDEX, HOOKKEY);
#define gethooktable(L) luaL_getsubtable(L, LUA_REGISTRYINDEX, HOOKKEY)
static void hookf (lua_State *L, lua_Debug *ar) {
static const char *const hooknames[] =
{"call", "return", "line", "count", "tail call"};
gethooktable(L);
- lua_rawgetp(L, -1, L);
lua_pushthread(L);
lua_rawget(L, -2);
if (lua_isfunction(L, -1)) {
lua_pushstring(L, hooknames[(int)ar->event]);
if (ar->currentline >= 0)
@@ -306,10 307,15 @@
count = luaL_optint(L, arg 3, 0);
func = hookf; mask = makemask(smask, count);
}
- gethooktable(L);
if (gethooktable(L) == 0) { /* creating hook table? */
lua_pushstring(L, "k");
lua_setfield(L, -2, "__mode"); /** hooktable.__mode = "k" */
lua_pushvalue(L, -1);
lua_setmetatable(L, -2); /* setmetatable(hooktable) = hooktable */
}
lua_pushthread(L1); lua_xmove(L1, L, 1);
lua_pushvalue(L, arg 1);
- lua_rawsetp(L, -2, L1); /* set new hook */
- lua_pop(L, 1); /* remove hook table */
lua_rawset(L, -3); /* set new hook */
lua_sethook(L1, func, mask, count); /* set hooks */
return 0;
}
@@ -325,7 331,8 @@
lua_pushliteral(L, "external hook");
else {
gethooktable(L);
- lua_rawgetp(L, -1, L1); /* get hook */
lua_pushthread(L1); lua_xmove(L1, L, 1);
lua_rawget(L, -2); /* get hook */
lua_remove(L, -2); /* remove hook table */
}
lua_pushstring(L, unmakemask(mask, buff));
Example:
print(0xE 1)
Patch:
llex.c:
@@ -223,12 223,19 @@
/* LUA_NUMBER */
static void read_numeral (LexState *ls, SemInfo *seminfo) {
const char *expo = "Ee";
int first = ls->current;
lua_assert(lisdigit(ls->current));
- do {
- save_and_next(ls);
- if (check_next(ls, "EePp")) /* exponent part? */
save_and_next(ls);
if (first == '0' && check_next(ls, "Xx")) /* hexadecimal? */
expo = "Pp";
for (;;) {
if (check_next(ls, expo)) /* exponent part? */
check_next(ls, " -"); /* optional exponent sign */
- } while (lislalnum(ls->current) || ls->current == '.');
if (lisxdigit(ls->current) || ls->current == '.')
save_and_next(ls);
else break;
}
save(ls, '\0');
buffreplace(ls, '.', ls->decpoint); /* follow locale for decimal point */
if (!buff2d(ls->buff, &seminfo->r)) /* format error? */
Example:
local u = setmetatable({}, {__gc = function () foo() end})
local m = require 'mod' -- 'mod' may be any dynamic library written in C
foo = m.foo -- 'foo' may be any function from 'mod'
-- end program; it crashes
Patch:
loadlib.c:
95c95
< #define LIBPREFIX "LOADLIB: "
---
> #define CLIBS "_CLIBS"
251,266c251,256
<
< static void **ll_register (lua_State *L, const char *path) {
< void **plib;
< lua_pushfstring(L, "%s%s", LIBPREFIX, path);
< lua_gettable(L, LUA_REGISTRYINDEX); /* check library in registry? */
< if (!lua_isnil(L, -1)) /* is there an entry? */
< plib = (void **)lua_touserdata(L, -1);
< else { /* no entry yet; create one */
< lua_pop(L, 1); /* remove result from gettable */
< plib = (void **)lua_newuserdata(L, sizeof(const void *));
< *plib = NULL;
< luaL_setmetatable(L, "_LOADLIB");
< lua_pushfstring(L, "%s%s", LIBPREFIX, path);
< lua_pushvalue(L, -2);
< lua_settable(L, LUA_REGISTRYINDEX);
< }
---
> static void *ll_checkclib (lua_State *L, const char *path) {
> void *plib;
> lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
> lua_getfield(L, -1, path);
> plib = lua_touserdata(L, -1); /* plib = CLIBS[path] */
> lua_pop(L, 2); /* pop CLIBS table and 'plib' */
270a261,270
> static void ll_addtoclib (lua_State *L, const char *path, void *plib) {
> lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
> lua_pushlightuserdata(L, plib);
> lua_pushvalue(L, -1);
> lua_setfield(L, -3, path); /* CLIBS[path] = plib */
> lua_rawseti(L, -2, luaL_len(L, -2) 1); /* CLIBS[#CLIBS 1] = plib */
> lua_pop(L, 1); /* pop CLIBS table */
> }
>
>
272,273c272,273
< ** __gc tag method: calls library's `ll_unloadlib' function with the lib
< ** handle
---
> ** __gc tag method for CLIBS table: calls 'll_unloadlib' for all lib
> ** handles in list CLIBS
276,278c276,281
< void **lib = (void **)luaL_checkudata(L, 1, "_LOADLIB");
< if (*lib) ll_unloadlib(*lib);
< *lib = NULL; /* mark library as closed */
---
> int n = luaL_len(L, 1);
> for (; n >= 1; n--) { /* for each handle, in reverse order */
> lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */
> ll_unloadlib(lua_touserdata(L, -1));
> lua_pop(L, 1); /* pop handle */
> }
284,286c287,292
< void **reg = ll_register(L, path);
< if (*reg == NULL) *reg = ll_load(L, path, *sym == '*');
< if (*reg == NULL) return ERRLIB; /* unable to load library */
---
> void *reg = ll_checkclib(L, path); /* check loaded C libraries */
> if (reg == NULL) { /* must load library? */
> reg = ll_load(L, path, *sym == '*');
> if (reg == NULL) return ERRLIB; /* unable to load library */
> ll_addtoclib(L, path, reg);
> }
292c298
< lua_CFunction f = ll_sym(L, *reg, sym);
---
> lua_CFunction f = ll_sym(L, reg, sym);
675,676c681,683
< /* create new type _LOADLIB */
< luaL_newmetatable(L, "_LOADLIB");
---
> /* create table CLIBS to keep track of loaded C libraries */
> luaL_getsubtable(L, LUA_REGISTRYINDEX, CLIBS);
> lua_createtable(L, 0, 1); /* metatable for CLIBS */
678a686
> lua_setmetatable(L, -2);
nCcalls in coroutines.
Example:
coroutine.wrap(function() print(pcall(pcall,pcall,pcall,pcall,pcall,error,3)) end)()
Patch:
ldo.c:
@@ -402,8 402,6 @@
int n;
lua_assert(ci->u.c.k != NULL); /* must have a continuation */
lua_assert(L->nny == 0);
- /* finish 'luaD_call' */
- L->nCcalls--;
/* finish 'lua_callk' */
adjustresults(L, ci->nresults);
/* call continuation function */
@@ -513,7 511,6 @@
api_checknelems(L, n);
firstArg = L->top - n; /* yield results come from continuation */
}
- L->nCcalls--; /* finish 'luaD_call' */
luaD_poscall(L, firstArg); /* finish 'luaD_precall' */
}
unroll(L, NULL);
Example:
local firsttime = true
local function foo ()
if firsttime then
firsttime = false
return "a = 1"
else
for i = 1, 10 do
print(debug.getlocal(2, i))
end
end
end
print(load(foo)) -- prints some lines and then crashes
Example: In C, set a line hook that simply yields, and then call any Lua function. You get an infinite loop of yields.
That was the last release of Lua 5.1. Bugs reported later are most probably fixed in Lua 5.2.
src/Makefile are not portable.
Example: This glitch happens when compiling Lua on some mingw systems; it does not seem to affect other systems.
Patch:
src/Makefile: @@ -50,3 50,3 @@ $(LUA_A): $(CORE_O) $(LIB_O) - $(AR) $@ $(CORE_O) $(LIB_O) # DLL needs all object files $(AR) $@ $(CORE_O) $(LIB_O) $(RANLIB) $@
Example:
load(function () print("called"); return nil end)
--> called
--> called (should be called only once!)
Patch:
lzio.h:
@@ -59,6 59,7 @@
lua_Reader reader;
void* data; /* additional data */
lua_State *L; /* Lua state (for reader) */
int eoz; /* true if reader has no more data */
};
lzio.c:
@@ -22,10 22,14 @@
size_t size;
lua_State *L = z->L;
const char *buff;
if (z->eoz) return EOZ;
lua_unlock(L);
buff = z->reader(L, z->data, &size);
lua_lock(L);
- if (buff == NULL || size == 0) return EOZ;
if (buff == NULL || size == 0) {
z->eoz = 1; /* avoid calling reader function next time */
return EOZ;
}
z->n = size - 1;
z->p = buff;
return char2int(*(z->p ));
@@ -51,6 55,7 @@
z->data = data;
z->n = 0;
z->p = NULL;
z->eoz = 0;
}
Solution: To avoid running precompiled code from untrusted sources, raise an error if the first byte in the stream is the escape character (decimal 27).
Example:
function lunpack(i, ...)
if i == 0 then
return ...
else
return lunpack(i-1, 1, ...)
end
end
Now, if C calls lunpack(n) with a huge n, it may end with
too many values in its stack and confuse its stack indices.
Example:
print(((1 or false) and true) or false) --> 1, but should be 'true'
Patch: (partial solution; see also 9)
lcode.c:
@@ -544,15 544,18 @@
pc = NO_JUMP; /* always true; do nothing */
break;
}
- case VFALSE: {
- pc = luaK_jump(fs); /* always jump */
- break;
- }
case VJMP: {
invertjump(fs, e);
pc = e->u.s.info;
break;
}
case VFALSE: {
if (!hasjumps(e)) {
pc = luaK_jump(fs); /* always jump */
break;
}
/* else go through */
}
default: {
pc = jumponcond(fs, e, 0);
break;
@@ -572,14 575,17 @@
pc = NO_JUMP; /* always false; do nothing */
break;
}
- case VTRUE: {
- pc = luaK_jump(fs); /* always jump */
- break;
- }
case VJMP: {
pc = e->u.s.info;
break;
}
case VTRUE: {
if (!hasjumps(e)) {
pc = luaK_jump(fs); /* always jump */
break;
}
/* else go through */
}
default: {
pc = jumponcond(fs, e, 1);
break;
luaV_settable may invalidate a reference to a table and try
to reuse it.
Example:
grandparent = {}
grandparent.__newindex = function(s,_,_) print(s) end
parent = {}
parent.__newindex = parent
setmetatable(parent, grandparent)
child = setmetatable({}, parent)
child.foo = 10 --> (crash on some machines)
Patch:
lvm.c:
@@ -133,6 133,7 @@
void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop;
TValue temp;
for (loop = 0; loop < MAXTAGLOOP; loop ) {
const TValue *tm;
if (ttistable(t)) { /* `t' is a table? */
@@ -152,7 153,9 @@
callTM(L, tm, t, key, val);
return;
}
- t = tm; /* else repeat with `tm' */
/* else repeat with `tm' */
setobj(L, &temp, tm); /* avoid pointing inside table (may rehash) */
t = &temp;
}
luaG_runerror(L, "loop in settable");
}
debug.getfenv does not check whether it has an argument.
Example:
debug.getfenv() -- should raise an error
Patch:
ldblib.c:
@@ -45,6 45,7 @@
static int db_getfenv (lua_State *L) {
luaL_checkany(L, 1);
lua_getfenv(L, 1);
return 1;
}
Example: See http://lua-users.org/lists/lua-l/2009-11/msg00463.html.
Patch:
llex.c:
@@ -118,8 118,10 @@
lua_State *L = ls->L;
TString *ts = luaS_newlstr(L, str, l);
TValue *o = luaH_setstr(L, ls->fs->h, ts); /* entry for `str' */
- if (ttisnil(o))
if (ttisnil(o)) {
setbvalue(o, 1); /* make sure `str' will not be collected */
luaC_checkGC(L);
}
return ts;
}
string.format may get buffer as an argument when there are
missing arguments and format string is too long.
Example:
x = string.rep("x", 10000) .. "%d"
print(string.format(x)) -- gives wrong error message
Patch:
lstrlib.c:
@@ -754,6 754,7 @@
static int str_format (lua_State *L) {
int top = lua_gettop(L);
int arg = 1;
size_t sfl;
const char *strfrmt = luaL_checklstring(L, arg, &sfl);
@@ -768,7 769,8 @@
else { /* format item */
char form[MAX_FORMAT]; /* to store the format (`%...') */
char buff[MAX_ITEM]; /* to store the formatted item */
- arg ;
if ( arg > top)
luaL_argerror(L, arg, "no value");
strfrmt = scanformat(L, strfrmt, form);
switch (*strfrmt ) {
case 'c': {
io.read("*n","*n") may return garbage if second read fails.
Example:
print(io.read("*n", "*n")) --<< enter "10 hi"
--> file (0x884420) nil
Patch:
liolib.c:
@@ -276,7 276,10 @@
lua_pushnumber(L, d);
return 1;
}
- else return 0; /* read fails */
else {
lua_pushnil(L); /* "result" to be removed */
return 0; /* read fails */
}
}
Example:
print((('hi' or true) and true) or true)
--> hi (should be true)
print(((nil and nil) or false) and true)
--> nil (should be false)
Patch: (to be applied after the patch in 3)
lcode.c:
@@ -549,13 549,6 @@
pc = e->u.s.info;
break;
}
- case VFALSE: {
- if (!hasjumps(e)) {
- pc = luaK_jump(fs); /* always jump */
- break;
- }
- /* else go through */
- }
default: {
pc = jumponcond(fs, e, 0);
break;
@@ -579,13 572,6 @@
pc = e->u.s.info;
break;
}
- case VTRUE: {
- if (!hasjumps(e)) {
- pc = luaK_jump(fs); /* always jump */
- break;
- }
- /* else go through */
- }
default: {
pc = jumponcond(fs, e, 1);
break;
Example:
meta={}
setmetatable(meta, meta)
meta.__newindex = function(t, key, value) print("set") end
o = setmetatable({}, meta)
o.x = 10 -- should print 'set'
Patch:
lvm.c:
@@ -142,6 142,7 @@
if (!ttisnil(oldval) || /* result is no nil? */
(tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
setobj2t(L, oldval, val);
h->flags = 0;
luaC_barriert(L, h, val);
return;
}
Patch:
lparser.c: @@ -374,9 374,9 @@ lua_assert(luaG_checkcode(f)); lua_assert(fs->bl == NULL); ls->fs = fs->prev; - L->top -= 2; /* remove table and prototype from the stack */ /* last token read was anchored in defunct function; must reanchor it */ if (fs) anchor_token(ls); L->top -= 2; /* remove table and prototype from the stack */ }
LUAI_MAXCSTACK must be smaller than -LUA_REGISTRYINDEX.
Example:
j = 1e4
co = coroutine.create(function()
t = {}
for i = 1, j do t[i] = i end
return unpack(t)
end)
print(coroutine.resume(co))
Patch:
luaconf.h: 443c443,444 < ** functions to consume unlimited stack space. --- > ** functions to consume unlimited stack space. (must be smaller than > ** -LUA_REGISTRYINDEX) 445,446c446 < #define LUAI_MCS_AUX ((int)(INT_MAX / (4*sizeof(LUA_NUMBER)))) < #define LUAI_MAXCSTACK (LUAI_MCS_AUX > SHRT_MAX ? SHRT_MAX : LUAI_MCS_AUX) --- > #define LUAI_MAXCSTACK 8000
coroutine.resume pushes element without ensuring stack size.
Example: This bug cannot be detected without internal assertions.
Patch:
lbaselib.c:
@@ -526,7 526,7 @@
status = lua_resume(co, narg);
if (status == 0 || status == LUA_YIELD) {
int nres = lua_gettop(co);
- if (!lua_checkstack(L, nres))
if (!lua_checkstack(L, nres 1))
luaL_error(L, "too many results to resume");
lua_xmove(co, L, nres); /* move yielded values */
return nres;
lua_checkstack may have arithmetic overflow for large 'size'.
Example:
print(unpack({1,2,3}, 0, 2^31-3))
Patch:
lapi.c:
@@ -93,15 93,14 @@
LUA_API int lua_checkstack (lua_State *L, int size) {
- int res;
int res = 1;
lua_lock(L);
- if ((L->top - L->base size) > LUAI_MAXCSTACK)
if (size > LUAI_MAXCSTACK || (L->top - L->base size) > LUAI_MAXCSTACK)
res = 0; /* stack overflow */
- else {
else if (size > 0) {
luaD_checkstack(L, size);
if (L->ci->top < L->top size)
L->ci->top = L->top size;
- res = 1;
}
lua_unlock(L);
return res;
unpack with maximum indices may crash due to arithmetic overflow.
Example:
print(unpack({1,2,3}, 2^31-1, 2^31-1))
Patch:
lbaselib.c:
@@ -344,10 344,12 @@
luaL_checktype(L, 1, LUA_TTABLE);
i = luaL_optint(L, 2, 1);
e = luaL_opt(L, luaL_checkint, 3, luaL_getn(L, 1));
if (i > e) return 0; /* empty range */
n = e - i 1; /* number of elements */
- if (n <= 0) return 0; /* empty range */
- luaL_checkstack(L, n, "table too big to unpack");
- for (; i<=e; i ) /* push arg[i...e] */
if (n <= 0 || !lua_checkstack(L, n)) /* n <= 0 means arith. overflow */
return luaL_error(L, "too many results to unpack");
lua_rawgeti(L, 1, i); /* push arg[i] (avoiding overflow problems) */
while (i < e) /* push arg[i 1...e] */
lua_rawgeti(L, 1, i);
return n;
}
Example:
a = string.dump(function()return;end) a = a:gsub(string.char(30,37,122,128), string.char(34,0,0), 1) loadstring(a)()
Patch:
ldebug.c:
@@ -275,12 275,12 @@
static int precheck (const Proto *pt) {
check(pt->maxstacksize <= MAXSTACK);
- lua_assert(pt->numparams (pt->is_vararg & VARARG_HASARG) <= pt->maxstacksize);
- lua_assert(!(pt->is_vararg & VARARG_NEEDSARG) ||
check(pt->numparams (pt->is_vararg & VARARG_HASARG) <= pt->maxstacksize);
check(!(pt->is_vararg & VARARG_NEEDSARG) ||
(pt->is_vararg & VARARG_HASARG));
check(pt->sizeupvalues <= pt->nups);
check(pt->sizelineinfo == pt->sizecode || pt->sizelineinfo == 0);
- check(GET_OPCODE(pt->code[pt->sizecode-1]) == OP_RETURN);
check(pt->sizecode > 0 && GET_OPCODE(pt->code[pt->sizecode-1]) == OP_RETURN);
return 1;
}
@@ -363,7 363,11 @@
}
switch (op) {
case OP_LOADBOOL: {
- check(c == 0 || pc 2 < pt->sizecode); /* check its jump */
if (c == 1) { /* does it jump? */
check(pc 2 < pt->sizecode); /* check its jump */
check(GET_OPCODE(pt->code[pc 1]) != OP_SETLIST ||
GETARG_C(pt->code[pc 1]) != 0);
}
break;
}
case OP_LOADNIL: {
@@ -428,7 432,10 @@
}
case OP_SETLIST: {
if (b > 0) checkreg(pt, a b);
- if (c == 0) pc ;
if (c == 0) {
pc ;
check(pc < pt->sizecode - 1);
}
break;
}
case OP_CLOSURE: {
Example:
function crash(depth)
local init = '\27\76\117\97\81\0\1\4\4\4\8\0\7\0\0\0\61\115\116' ..
'\100\105\110\0\1\0\0\0\1\0\0\0\0\0\0\2\2\0\0\0\36' ..
'\0\0\0\30\0\128\0\0\0\0\0\1\0\0\0\0\0\0\0\1\0\0\0' ..
'\1\0\0\0\0\0\0\2'
local mid = '\1\0\0\0\30\0\128\0\0\0\0\0\0\0\0\0\1\0\0\0\1\0\0\0\0'
local fin = '\0\0\0\0\0\0\0\2\0\0\0\1\0\0\0\1\0\0\0\1\0\0\0\2\0' ..
'\0\0\97\0\1\0\0\0\1\0\0\0\0\0\0\0'
local lch = '\2\0\0\0\36\0\0\0\30\0\128\0\0\0\0\0\1\0\0\0\0\0\0' ..
'\0\1\0\0\0\1\0\0\0\0\0\0\2'
local rch = '\0\0\0\0\0\0\0\2\0\0\0\1\0\0\0\1\0\0\0\1\0\0\0\2\0' ..
'\0\0\97\0\1\0\0\0\1'
for i=1,depth do lch,rch = lch..lch,rch..rch end
loadstring(init .. lch .. mid .. rch .. fin)
end
for i=1,25 do print(i); crash(i) end
Patch:
lundump.c:
@@ -161,7 160,9 @@
static Proto* LoadFunction(LoadState* S, TString* p)
{
- Proto* f=luaF_newproto(S->L);
Proto* f;
if ( S->L->nCcalls > LUAI_MAXCCALLS) error(S,"code too deep");
f=luaF_newproto(S->L);
setptvalue2s(S->L,S->L->top,f); incr_top(S->L);
f->source=LoadString(S); if (f->source==NULL) f->source=p;
f->linedefined=LoadInt(S);
@@ -175,6 176,7 @@
LoadDebug(S,f);
IF (!luaG_checkcode(f), "bad code");
S->L->top--;
S->L->nCcalls--;
return f;
}
Example:
z={}
for i=1,27290 do z[i]='1,' end
z = 'if 1 1==2 then local a={' .. table.concat(z) .. '} end'
func = loadstring(z)
print(loadstring(string.dump(func)))
Patch:
ldebug.c:
@@ -346,9 346,18 @@
int dest = pc 1 b;
check(0 <= dest && dest < pt->sizecode);
if (dest > 0) {
- /* cannot jump to a setlist count */
- Instruction d = pt->code[dest-1];
- check(!(GET_OPCODE(d) == OP_SETLIST && GETARG_C(d) == 0));
int j;
/* check that it does not jump to a setlist count; this
is tricky, because the count from a previous setlist may
have the same value of an invalid setlist; so, we must
go all the way back to the first of them (if any) */
for (j = 0; j < dest; j ) {
Instruction d = pt->code[dest-1-j];
if (!(GET_OPCODE(d) == OP_SETLIST && GETARG_C(d) == 0)) break;
}
/* if 'j' is even, previous value is not a setlist (even if
it looks like one) */
check((j&1) == 0);
}
}
break;
Example:
maybe = string.dump(function() return ({[true]=true})[true] end)
maybe = maybe:gsub('\1\1','\1\2')
maybe = loadstring(maybe)()
assert(type(maybe) == "boolean" and maybe ~= true and maybe ~= false)
Patch:
lundump.c:
@@ -115,7 115,7 @@
setnilvalue(o);
break;
case LUA_TBOOLEAN:
- setbvalue(o,LoadChar(S));
setbvalue(o,LoadChar(S)!=0);
break;
case LUA_TNUMBER:
setnvalue(o,LoadNumber(S));
string.byte gets confused with some out-of-range negative indices.
Example:
print(string.byte("abc", -5)) --> 97 98 99 (should print nothing)
Patch:
lstrlib.c:
@@ -35,7 35,8 @@
static ptrdiff_t posrelat (ptrdiff_t pos, size_t len) {
/* relative string position: negative means back from end */
- return (pos>=0) ? pos : (ptrdiff_t)len pos 1;
if (pos < 0) pos = (ptrdiff_t)len 1;
return (pos >= 0) ? pos : 0;
}
Example:
collectgarbage("setpause", 100) -- small value
collectgarbage("setstepmul", 2000) -- large value
collectgarbage("step",0)
Patch:
lapi.c:
@@ -929,10 929,13 @@
g->GCthreshold = g->totalbytes - a;
else
g->GCthreshold = 0;
- while (g->GCthreshold <= g->totalbytes)
while (g->GCthreshold <= g->totalbytes) {
luaC_step(L);
- if (g->gcstate == GCSpause) /* end of cycle? */
- res = 1; /* signal it */
if (g->gcstate == GCSpause) { /* end of cycle? */
res = 1; /* signal it */
break;
}
}
break;
}
case LUA_GCSETPAUSE: {
module may change the environment of a C function.
Example:
pcall(module, "xuxu") assert(debug.getfenv(pcall) == xuxu)
Patch:
loadlib.c:
@@ -506,8 506,11 @@
static void setfenv (lua_State *L) {
lua_Debug ar;
- lua_getstack(L, 1, &ar);
- lua_getinfo(L, "f", &ar);
if (lua_getstack(L, 1, &ar) == 0 ||
lua_getinfo(L, "f", &ar) == 0 || /* get calling function */
lua_iscfunction(L, -1))
luaL_error(L, "function " LUA_QL("module")
" not called from a Lua function");
lua_pushvalue(L, -2);
lua_setfenv(L, -2);
lua_pop(L, 1);
svalue is wrong.
Example:
/* in luaconf.h */
#define LUAI_USER_ALIGNMENT_T union { char b[32]; }
Patch:
lobject.h: @@ -210,3 210,3 @@ #define getstr(ts) cast(const char *, (ts) 1) -#define svalue(o) getstr(tsvalue(o)) #define svalue(o) getstr(rawtsvalue(o))
-nil, -true, and -false is wrong.
Example:
print(-nil)
Patch:
lcode.c:
@@ -699,7 699,7 @@
e2.t = e2.f = NO_JUMP; e2.k = VKNUM; e2.u.nval = 0;
switch (op) {
case OPR_MINUS: {
- if (e->k == VK)
if (!isnumeral(e))
luaK_exp2anyreg(fs, e); /* cannot operate on non-numeric constants */
codearith(fs, OP_UNM, e, &e2);
break;
Patch:
lvm.c:
@@ -61,11 61,9 @@
lu_byte mask = L->hookmask;
const Instruction *oldpc = L->savedpc;
L->savedpc = pc;
- if (mask > LUA_MASKLINE) { /* instruction-hook set? */
- if (L->hookcount == 0) {
- resethookcount(L);
- luaD_callhook(L, LUA_HOOKCOUNT, -1);
- }
if ((mask & LUA_MASKCOUNT) && L->hookcount == 0) {
resethookcount(L);
luaD_callhook(L, LUA_HOOKCOUNT, -1);
}
if (mask & LUA_MASKLINE) {
Proto *p = ci_func(L->ci)->l.p;
Example:
a = function(a) coroutine.wrap(a)(a) end a(a)
Patch: The 'nCcalls' counter should be shared by all threads. (That is, it should be declared in the 'global_State' structure, not in 'lua_State'.)
Example:
a = nil; a = (1)..a
Patch:
ldebug.c:
@@ -563,8 563,8 @@
void luaG_concaterror (lua_State *L, StkId p1, StkId p2) {
- if (ttisstring(p1)) p1 = p2;
- lua_assert(!ttisstring(p1));
if (ttisstring(p1) || ttisnumber(p1)) p1 = p2;
lua_assert(!ttisstring(p1) && !ttisnumber(p1));
luaG_typeerror(L, p1, "concatenate");
}
Patch:
ltable.c: 87,88c87,88 < n = 1; /* normalize number (avoid -0) */ < lua_assert(sizeof(a) <= sizeof(n)); --- > if (luai_numeq(n, 0)) /* avoid problems with -0 */ > return gnode(t, 0);
Example:
$ ulimit -s 1024 # Reduce C stack to 1MB for quicker results
$ lua -e 'local s = "a,"; for i=1,18 do s = s..s end print(loadstring("local a;"..s.."a=nil", ""))'
Patch:
lparser.c:
@@ -938,6 938,8 @@
primaryexp(ls, &nv.v);
if (nv.v.k == VLOCAL)
check_conflict(ls, lh, &nv.v);
luaY_checklimit(ls->fs, nvars, LUAI_MAXCCALLS - ls->L->nCcalls,
"variable names");
assignment(ls, &nv, nvars 1);
}
else { /* assignment -> `=' explist1 */
Example:
lua -ltemp (assuming temp.lua has an error)
Patch:
lua.c:
@@ -144,7 144,7 @@
static int dolibrary (lua_State *L, const char *name) {
lua_getglobal(L, "require");
lua_pushstring(L, name);
- return report(L, lua_pcall(L, 1, 0, 0));
return report(L, docall(L, 1, 1));
}
gsub may go wild when wrongly called without its third
argument and with a large subject.
Example:
x = string.rep('a', 10000) .. string.rep('b', 10000)
print(#string.gsub(x, 'b'))
Patch:
lstrlib.c:
@@ -631,6 631,2 @@
}
- default: {
- luaL_argerror(L, 3, "string/function/table expected");
- return;
- }
}
@@ -650,2 646,3 @@
const char *p = luaL_checkstring(L, 2);
int tr = lua_type(L, 3);
int max_s = luaL_optint(L, 4, srcl 1);
@@ -655,2 652,5 @@
luaL_Buffer b;
luaL_argcheck(L, tr == LUA_TNUMBER || tr == LUA_TSTRING ||
tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3,
"string/function/table expected");
luaL_buffinit(L, &b);
table.remove removes last element of a table when given
an out-of-bound index.
Example:
a = {1,2,3}
table.remove(a, 4)
print(a[3]) --> nil (should be 3)
Patch:
ltablib.c:
@@ -118,7 118,8 @@
static int tremove (lua_State *L) {
int e = aux_getn(L, 1);
int pos = luaL_optint(L, 2, e);
- if (e == 0) return 0; /* table is `empty' */
if (!(1 <= pos && pos <= e)) /* position is outside bounds? */
return 0; /* nothing to remove */
luaL_setn(L, 1, e - 1); /* t.n = n-1 */
lua_rawgeti(L, 1, pos); /* result = t[pos] */
for ( ;pos<e; pos ) {
lua_setfenv may crash if called over an invalid object.
Example:
> debug.setfenv(3, {})
Patch:
lapi.c:
@@ -749,7 749,7 @@
res = 0;
break;
}
- luaC_objbarrier(L, gcvalue(o), hvalue(L->top - 1));
if (res) luaC_objbarrier(L, gcvalue(o), hvalue(L->top - 1));
L->top--;
lua_unlock(L);
return res;
Example:
> error(coroutine.create(function() end))
Patch:
lua.c:
@@ -74,6 74,8 @@
static int traceback (lua_State *L) {
if (!lua_isstring(L, 1)) /* 'message' not a string? */
return 1; /* keep it intact */
lua_getfield(L, LUA_GLOBALSINDEX, "debug");
if (!lua_istable(L, -1)) {
lua_pop(L, 1);
debug.sethook/gethook may overflow the thread's stack.
Example:
a = coroutine.create(function() yield() end) coroutine.resume(a) debug.sethook(a) -- may overflow the stack of 'a'
Patch:
ldblib.c:
@@ -268,12 268,11 @@
count = luaL_optint(L, arg 3, 0);
func = hookf; mask = makemask(smask, count);
}
- gethooktable(L1);
- lua_pushlightuserdata(L1, L1);
gethooktable(L);
lua_pushlightuserdata(L, L1);
lua_pushvalue(L, arg 1);
- lua_xmove(L, L1, 1);
- lua_rawset(L1, -3); /* set new hook */
- lua_pop(L1, 1); /* remove hook table */
lua_rawset(L, -3); /* set new hook */
lua_pop(L, 1); /* remove hook table */
lua_sethook(L1, func, mask, count); /* set hooks */
return 0;
}
@@ -288,11 287,10 @@
if (hook != NULL && hook != hookf) /* external hook? */
lua_pushliteral(L, "external hook");
else {
- gethooktable(L1);
- lua_pushlightuserdata(L1, L1);
- lua_rawget(L1, -2); /* get hook */
- lua_remove(L1, -2); /* remove hook table */
- lua_xmove(L1, L, 1);
gethooktable(L);
lua_pushlightuserdata(L, L1);
lua_rawget(L, -2); /* get hook */
lua_remove(L, -2); /* remove hook table */
}
lua_pushstring(L, unmakemask(mask, buff));
lua_pushinteger(L, lua_gethookcount(L1));
Example:
a = {}
a[1] = "x={1"
for i = 2, 2^20 do
a[i] = 1
end
a[#a 1] = "}"
s = table.concat(a, ",")
assert(loadstring(s))()
print(#x)
Patch:
lparser.c:
@@ -489,7 489,7 @@
static void listfield (LexState *ls, struct ConsControl *cc) {
expr(ls, &cc->v);
- luaY_checklimit(ls->fs, cc->na, MAXARG_Bx, "items in a constructor");
luaY_checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor");
cc->na ;
cc->tostore ;
}
Example:
local Var local function main() NoSuchName (function() Var=0 end) end main()The error message is attempt to call upvalue 'Var' (a nil value). It should be attempt to call global 'NoSuchName' (a nil value).
Patch:
ldebug.c:
@@ -435,14 435,16 @@
break;
}
case OP_CLOSURE: {
- int nup;
int nup, j;
check(b < pt->sizep);
nup = pt->p[b]->nups;
check(pc nup < pt->sizecode);
- for (; nup>0; nup--) {
- OpCode op1 = GET_OPCODE(pt->code[pc nup]);
for (j = 1; j <= nup; j ) {
OpCode op1 = GET_OPCODE(pt->code[pc j]);
check(op1 == OP_GETUPVAL || op1 == OP_MOVE);
}
if (reg != NO_REG) /* tracing? */
pc = nup; /* do not 'execute' these pseudo-instructions */
break;
}
case OP_VARARG: {
string.format("%") may read past the string.
Example:
print(string.format("%"))
Patch:
lstrlib.c:
@@ -723,7 723,7 @@
static const char *scanformat (lua_State *L, const char *strfrmt, char *form) {
const char *p = strfrmt;
- while (strchr(FLAGS, *p)) p ; /* skip flags */
while (*p != '\0' && strchr(FLAGS, *p) != NULL) p ; /* skip flags */
if ((size_t)(p - strfrmt) >= sizeof(FLAGS))
luaL_error(L, "invalid format (repeated flags)");
if (isdigit(uchar(*p))) p ; /* skip width */
os.date throws an error when result is the empty string.
Example:
print(os.date(""))
Patch:
loslib.c:
@@ -148,7 148,18 @@
else {
- char b[256];
- if (strftime(b, sizeof(b), s, stm))
- lua_pushstring(L, b);
- else
- return luaL_error(L, LUA_QL("date") " format too long");
char cc[3];
luaL_Buffer b;
cc[0] = '%'; cc[2] = '\0';
luaL_buffinit(L, &b);
for (; *s; s ) {
if (*s != '%' || *(s 1) == '\0') /* no conversion specifier? */
luaL_addchar(&b, *s);
else {
size_t reslen;
char buff[200]; /* should be big enough for any conversion result */
cc[1] = *( s);
reslen = strftime(buff, sizeof(buff), cc, stm);
luaL_addlstring(&b, buff, reslen);
}
}
luaL_pushresult(&b);
}
setfenv accepts invalid first argument.
Example:
setfenv(nil, {}) -- should throw an error
Patch:
lbaselib.c:
@@ -116,3 116,3 @@
-static void getfunc (lua_State *L) {
static void getfunc (lua_State *L, int opt) {
if (lua_isfunction(L, 1)) lua_pushvalue(L, 1);
@@ -120,3 120,3 @@
lua_Debug ar;
- int level = luaL_optint(L, 1, 1);
int level = opt ? luaL_optint(L, 1, 1) : luaL_checkint(L, 1);
luaL_argcheck(L, level >= 0, 1, "level must be non-negative");
@@ -133,3 133,3 @@
static int luaB_getfenv (lua_State *L) {
- getfunc(L);
getfunc(L, 1);
if (lua_iscfunction(L, -1)) /* is a C function? */
@@ -144,3 144,3 @@
luaL_checktype(L, 2, LUA_TTABLE);
- getfunc(L);
getfunc(L, 0);
lua_pushvalue(L, 2);
Example:
-- use a large number of names (almost 256)
v1=1; v2=1; v3=1; v4=1; v5=1; v6=1; v7=1; v8=1; v9=1;
v10=1; v11=1; v12=1; v13=1; v14=1; v15=1; v16=1; v17=1;
v18=1; v19=1; v20=1; v21=1; v22=1; v23=1; v24=1; v25=1;
v26=1; v27=1; v28=1; v29=1; v30=1; v31=1; v32=1; v33=1;
v34=1; v35=1; v36=1; v37=1; v38=1; v39=1; v40=1; v41=1;
v42=1; v43=1; v44=1; v45=1; v46=1; v47=1; v48=1; v49=1;
v50=1; v51=1; v52=1; v53=1; v54=1; v55=1; v56=1; v57=1;
v58=1; v59=1; v60=1; v61=1; v62=1; v63=1; v64=1; v65=1;
v66=1; v67=1; v68=1; v69=1; v70=1; v71=1; v72=1; v73=1;
v74=1; v75=1; v76=1; v77=1; v78=1; v79=1; v80=1; v81=1;
v82=1; v83=1; v84=1; v85=1; v86=1; v87=1; v88=1; v89=1;
v90=1; v91=1; v92=1; v93=1; v94=1; v95=1; v96=1; v97=1;
v98=1; v99=1; v100=1; v101=1; v102=1; v103=1; v104=1; v105=1;
v106=1; v107=1; v108=1; v109=1; v110=1; v111=1; v112=1; v113=1;
v114=1; v115=1; v116=1; v117=1; v118=1; v119=1; v120=1; v121=1;
v122=1; v123=1; v124=1; v125=1; v126=1; v127=1; v128=1; v129=1;
v130=1; v131=1; v132=1; v133=1; v134=1; v135=1; v136=1; v137=1;
v138=1; v139=1; v140=1; v141=1; v142=1; v143=1; v144=1; v145=1;
v146=1; v147=1; v148=1; v149=1; v150=1; v151=1; v152=1; v153=1;
v154=1; v155=1; v156=1; v157=1; v158=1; v159=1; v160=1; v161=1;
v162=1; v163=1; v164=1; v165=1; v166=1; v167=1; v168=1; v169=1;
v170=1; v171=1; v172=1; v173=1; v174=1; v175=1; v176=1; v177=1;
v178=1; v179=1; v180=1; v181=1; v182=1; v183=1; v184=1; v185=1;
v186=1; v187=1; v188=1; v189=1; v190=1; v191=1; v192=1; v193=1;
v194=1; v195=1; v196=1; v197=1; v198=1; v199=1; v200=1; v201=1;
v202=1; v203=1; v204=1; v205=1; v206=1; v207=1; v208=1; v209=1;
v210=1; v211=1; v212=1; v213=1; v214=1; v215=1; v216=1; v217=1;
v218=1; v219=1; v220=1; v221=1; v222=1; v223=1; v224=1; v225=1;
v226=1; v227=1; v228=1; v229=1; v230=1; v231=1; v232=1; v233=1;
v234=1; v235=1; v236=1; v237=1; v238=1; v239=1; v240=1; v241=1;
v242=1; v243=1; v244=1; v245=1; v246=1; v247=1; v248=1; v249=1;
v250=1;
v251={k1 = 1};
v252=1;
print(2 * v251.k1, v251.k1 * 2); -- 2 2, OK
v253=1;
print(2 * v251.k1, v251.k1 * 2); -- 1 2, ???
Patch:
lcode.c:
@@ -657,10 657,16 @@
if (constfolding(op, e1, e2))
return;
else {
- int o1 = luaK_exp2RK(fs, e1);
int o2 = (op != OP_UNM && op != OP_LEN) ? luaK_exp2RK(fs, e2) : 0;
- freeexp(fs, e2);
- freeexp(fs, e1);
int o1 = luaK_exp2RK(fs, e1);
if (o1 > o2) {
freeexp(fs, e1);
freeexp(fs, e2);
}
else {
freeexp(fs, e2);
freeexp(fs, e1);
}
e1->u.s.info = luaK_codeABC(fs, op, 0, o1, o2);
e1->k = VRELOCABLE;
}
@@ -718,10 724,15 @@
luaK_exp2nextreg(fs, v); /* operand must be on the `stack' */
break;
}
- default: {
case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV:
case OPR_MOD: case OPR_POW: {
if (!isnumeral(v)) luaK_exp2RK(fs, v);
break;
}
default: {
luaK_exp2RK(fs, v);
break;
}
}
}
Example:
function f (a)
a=nil
return a
end
print(f("test"))
Patch:
lcode.c:
@@ -35,16 35,20 @@
void luaK_nil (FuncState *fs, int from, int n) {
Instruction *previous;
if (fs->pc > fs->lasttarget) { /* no jumps to current position? */
- if (fs->pc == 0) /* function start? */
- return; /* positions are already clean */
- previous = &fs->f->code[fs->pc-1];
- if (GET_OPCODE(*previous) == OP_LOADNIL) {
- int pfrom = GETARG_A(*previous);
- int pto = GETARG_B(*previous);
- if (pfrom <= from && from <= pto 1) { /* can connect both? */
- if (from n-1 > pto)
- SETARG_B(*previous, from n-1);
- return;
if (fs->pc == 0) { /* function start? */
if (from >= fs->nactvar)
return; /* positions are already clean */
}
else {
previous = &fs->f->code[fs->pc-1];
if (GET_OPCODE(*previous) == OP_LOADNIL) {
int pfrom = GETARG_A(*previous);
int pto = GETARG_B(*previous);
if (pfrom <= from && from <= pto 1) { /* can connect both? */
if (from n-1 > pto)
SETARG_B(*previous, from n-1);
return;
}
}
}
}
Example:
a = {}
setmetatable(a, {__concat = function (a,b) print(type(a), type(b)) end})
a = 4 .. a
Patch:
lvm.c:
@@ -281,10 281,12 @@
do {
StkId top = L->base last 1;
int n = 2; /* number of elements handled in this pass (at least 2) */
- if (!tostring(L, top-2) || !tostring(L, top-1)) {
if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
luaG_concaterror(L, top-2, top-1);
- } else if (tsvalue(top-1)->len > 0) { /* if len=0, do nothing */
} else if (tsvalue(top-1)->len == 0) /* second op is empty? */
(void)tostring(L, top - 2); /* result is first op (as string) */
else {
/* at least two string values; get as many as possible */
size_t tl = tsvalue(top-1)->len;
char *buffer;
loadlib.c is a library and should not access Lua internals (via lobject.h).
Example: The bug has no effect on external behavior.
Patch:
In loadlib.c, change all ocurrences of luaO_pushfstring to
lua_pushfstring.
Example:
print(false or 0) -- on 16-bit machines
Patch:
lcode.c:
@@ -731,17 731,15 @@
case OPR_AND: {
lua_assert(e1->t == NO_JUMP); /* list must be closed */
luaK_dischargevars(fs, e2);
- luaK_concat(fs, &e1->f, e2->f);
- e1->k = e2->k; e1->u.s.info = e2->u.s.info;
- e1->u.s.aux = e2->u.s.aux; e1->t = e2->t;
luaK_concat(fs, &e2->f, e1->f);
*e1 = *e2;
break;
}
case OPR_OR: {
lua_assert(e1->f == NO_JUMP); /* list must be closed */
luaK_dischargevars(fs, e2);
- luaK_concat(fs, &e1->t, e2->t);
- e1->k = e2->k; e1->u.s.info = e2->u.s.info;
- e1->u.s.aux = e2->u.s.aux; e1->f = e2->f;
luaK_concat(fs, &e2->t, e1->t);
*e1 = *e2;
break;
}
luaL_checkudata may produce wrong error message.
Example:
getmetatable(io.stdin).__gc() --> bad argument #1 to '__gc' (FILE* expected, got table)
Patch:
lauxlib.c:
@@ -123,11 123,17 @@
LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {
void *p = lua_touserdata(L, ud);
- lua_getfield(L, LUA_REGISTRYINDEX, tname); /* get correct metatable */
- if (p == NULL || !lua_getmetatable(L, ud) || !lua_rawequal(L, -1, -2))
- luaL_typerror(L, ud, tname);
- lua_pop(L, 2); /* remove both metatables */
- return p;
if (p != NULL) { /* value is a userdata? */
if (lua_getmetatable(L, ud)) { /* does it have a metatable? */
lua_getfield(L, LUA_REGISTRYINDEX, tname); /* get correct metatable */
if (lua_rawequal(L, -1, -2)) { /* does it have the correct mt? */
lua_pop(L, 2); /* remove both metatables */
return p;
}
}
}
luaL_typerror(L, ud, tname); /* else error */
return NULL; /* to avoid warnings */
}
Patch:
The simplest solution is to use DirectX with
the D3DCREATE_FPU_PRESERVE flag.
Otherwise, you can change the definition of lua_number2int
in luaconf.h to this one:
#define lua_number2int(i,d) __asm fld d __asm fistp i
string.formatE does not handle '\r' correctly.
Example:
local s = "a string with \r and \n and \r\n and \n\r"
local c = string.format("return %q", s)
assert(assert(loadstring(c))() == s)
Patch:
lstrlib.c:
@@ -703,6 703,10 @@
luaL_addchar(b, *s);
break;
}
case '\r': {
luaL_addlstring(b, "\\r", 2);
break;
}
case '\0': {
luaL_addlstring(b, "\\000", 4);
break;
luaL_dofile and luaL_dostring
should return all values returned by the chunk.
Patch:
lauxlib.h:
@@ -108,9 108,11 @@
#define luaL_typename(L,i) lua_typename(L, lua_type(L,(i)))
-#define luaL_dofile(L, fn) (luaL_loadfile(L, fn) || lua_pcall(L, 0, 0, 0))
#define luaL_dofile(L, fn) \
(luaL_loadfile(L, fn) || lua_pcall(L, 0, LUA_MULTRET, 0))
-#define luaL_dostring(L, s) (luaL_loadstring(L, s) || lua_pcall(L, 0, 0, 0))
#define luaL_dostring(L, s) \
(luaL_loadstring(L, s) || lua_pcall(L, 0, LUA_MULTRET, 0))
#define luaL_getmetatable(L,n) (lua_getfield(L, LUA_REGISTRYINDEX, (n)))
Patch:
lgc.c:
@@ -322,4 322,6 @@
-static void propagateall (global_State *g) {
- while (g->gray) propagatemark(g);
static size_t propagateall (global_State *g) {
size_t m = 0;
while (g->gray) m = propagatemark(g);
return m;
}
@@ -542,3 544,3 @@
marktmu(g); /* mark `preserved' userdata */
- propagateall(g); /* remark, to propagate `preserveness' */
udsize = propagateall(g); /* remark, to propagate `preserveness' */
cleartable(g->weak); /* remove collected objects from weak tables */
@@ -592,2 863,4 @@
GCTM(L);
if (g->estimate > GCFINALIZECOST)
g->estimate -= GCFINALIZECOST;
Example:
co = coroutine.create(function () coroutine.yield() end) debug.sethook(co, function() end, "lr") coroutine.resume(co) coroutine.resume(co)
Patch:
ldo.c:
@@ -389,6 389,7 @@
return;
}
else { /* resuming from previous yield */
L->status = 0;
if (!f_isLua(ci)) { /* `common' yield? */
/* finish interrupted execution of `OP_CALL' */
lua_assert(GET_OPCODE(*((ci-1)->savedpc - 1)) == OP_CALL ||
@@ -399,7 400,6 @@
else /* yielded inside a hook: just continue its execution */
L->base = L->ci->base;
}
- L->status = 0;
luaV_execute(L, cast_int(L->ci - L->base_ci));
}
That was the last release of Lua 5.0. Bugs reported later are most probably fixed in Lua 5.1.
Example:
longs = string.rep("\0", 2^25)
function catter(i)
return assert(loadstring(
string.format("return function(a) return a%s end",
string.rep("..a", i-1))))()
end
rep129 = catter(129)
rep129(longs)
Patch:
lvm.c:
@@ -321,15 321,15 @@
luaG_concaterror(L, top-2, top-1);
} else if (tsvalue(top-1)->tsv.len > 0) { /* if len=0, do nothing */
/* at least two string values; get as many as possible */
- lu_mem tl = cast(lu_mem, tsvalue(top-1)->tsv.len)
- cast(lu_mem, tsvalue(top-2)->tsv.len);
size_t tl = tsvalue(top-1)->tsv.len;
char *buffer;
int i;
- while (n < total && tostring(L, top-n-1)) { /* collect total length */
- tl = tsvalue(top-n-1)->tsv.len;
- n ;
/* collect total length */
for (n = 1; n < total && tostring(L, top-n-1); n ) {
size_t l = tsvalue(top-n-1)->tsv.len;
if (l >= MAX_SIZET - tl) luaG_runerror(L, "string length overflow");
tl = l;
}
- if (tl > MAX_SIZET) luaG_runerror(L, "string size overflow");
buffer = luaZ_openspace(L, &G(L)->buff, tl);
tl = 0;
for (i=n; i>0; i--) { /* concat all strings */
lua_getupvalue and lua_setupvalue do not check for index too small.
Example:
debug.getupvalue(function() end, 0)
Patch:
lapi.c 941c941 < if (n > f->c.nupvalues) return NULL; --- > if (!(1 <= n && n <= f->c.nupvalues)) return NULL; 947c947 < if (n > p->sizeupvalues) return NULL; --- > if (!(1 <= n && n <= p->sizeupvalues)) return NULL;
Example:
local thread_id = 0
local threads = {}
function fn(thread)
thread_id = thread_id 1
threads[thread_id] = function()
thread = nil
end
coroutine.yield()
end
while true do
local thread = coroutine.create(fn)
coroutine.resume(thread, thread)
end
Patch:
lgc.c:
221,224c221,222
< if (!u->marked) {
< markobject(st, &u->value);
< u->marked = 1;
< }
---
> markobject(st, u->v);
> u->marked = 1;
rawset and rawget do not ignore extra arguments.
Example:
a = {}
rawset(a, 1, 2, 3)
print(a[1], a[2]) -- should be 2 and nil
Patch:
lbaselib.c: 175a176 > lua_settop(L, 2); 183a185 > lua_settop(L, 3);
Example:
a = {}
print(gcinfo())
for i = 1, 10000 do
a[i] = setmetatable({}, {__mode = "v"})
end
collectgarbage()
a = nil
collectgarbage()
print(gcinfo())
Patch:
lgc.c
@@ -366,7 366,7 @@
GCObject *curr;
int count = 0; /* number of collected items */
while ((curr = *p) != NULL) {
- if (curr->gch.marked > limit) {
if ((curr->gch.marked & ~(KEYWEAK | VALUEWEAK)) > limit) {
unmark(curr);
p = &curr->gch.next;
}
Example:
-- should print false, but prints nil print(not not (nil and 4))
io.popen) may crash Lua.
Example:
f = io.popen("ls")
f:close()
lua_closethread exists only in the manual.
Solution: The manual is wrong: threads are subject to garbage collection.
Example:
function co_func (current_co) coroutine.resume(co) end co = coroutine.create(co_func) coroutine.resume(co) coroutine.resume(co) --> crash
Patch:
ldo.c:
325,326c325
< if (nargs >= L->top - L->base)
< luaG_runerror(L, "cannot resume dead coroutine");
---
> lua_assert(nargs < L->top - L->base);
329c328,329
< else if (ci->state & CI_YIELD) { /* inside a yield? */
---
> else { /* inside a yield */
> lua_assert(ci->state & CI_YIELD);
344,345d343
< else
< luaG_runerror(L, "cannot resume non-suspended coroutine");
351a350,358
> static int resume_error (lua_State *L, const char *msg) {
> L->top = L->ci->base;
> setsvalue2s(L->top, luaS_new(L, msg));
> incr_top(L);
> lua_unlock(L);
> return LUA_ERRRUN;
> }
>
>
355a363,368
> if (L->ci == L->base_ci) {
> if (nargs >= L->top - L->base)
> return resume_error(L, "cannot resume dead coroutine");
> }
> else if (!(L->ci->state & CI_YIELD)) /* not inside a yield? */
> return resume_error(L, "cannot resume non-suspended coroutine");
file:close cannot be called without a file (results a crash).
Example:
> io.stdin.close() -- correct call should be io.stdin:close()
Patch:
liolib.c:
161c161
< if (lua_isnone(L, 1)) {
---
> if (lua_isnone(L, 1) && lua_type(L, lua_upvalueindex(1)) == LUA_TTABLE) {
Example:
Must recompile Lua with a change in lua.c and with lua_assert defined:
lua.c: 381a382 > lua_checkstack(l, 1000);
Patch:
lgc.c: 247c247 < if (!(ci->state & CI_C) && lim < ci->top) --- > if (lim < ci->top)
Example:
function g(x)
coroutine.yield(x)
end
function f (i)
debug.sethook(print, "l")
for j=1,1000 do
g(i j)
end
end
co = coroutine.wrap(f)
co(10)
pcall(co)
pcall(co)
Patch:
lvm.c: 402d401 < L->ci->u.l.pc = &pc; 405a405 > L->ci->u.l.pc = &pc; 676,678c676 < lua_assert(ci->u.l.pc == &pc && < ttisfunction(ci->base - 1) && < (ci->state & CI_SAVEDPC)); --- > lua_assert(ttisfunction(ci->base - 1) && (ci->state & CI_SAVEDPC));
Example:
a = newproxy(true) getmetatable(a).__gc = function () end for i=1,10000000 do newproxy(a) if math.mod(i, 10000) == 0 then print(gcinfo()) end end
Patch:
lgc.h:
18c18
< void luaC_separateudata (lua_State *L);
---
> size_t luaC_separateudata (lua_State *L);
lgc.c:
113c113,114
< void luaC_separateudata (lua_State *L) {
---
> size_t luaC_separateudata (lua_State *L) {
> size_t deadmem = 0;
127a129
> deadmem = sizeudata(gcotou(curr)->uv.len);
136a139
> return deadmem;
390c393
< static void checkSizes (lua_State *L) {
---
> static void checkSizes (lua_State *L, size_t deadmem) {
400c403
< G(L)->GCthreshold = 2*G(L)->nblocks; /* new threshold */
---
> G(L)->GCthreshold = 2*G(L)->nblocks - deadmem; /* new threshold */
454c457,458
< static void mark (lua_State *L) {
---
> static size_t mark (lua_State *L) {
> size_t deadmem;
467c471
< luaC_separateudata(L); /* separate userdata to be preserved */
---
> deadmem = luaC_separateudata(L); /* separate userdata to be preserved */
475a480
> return deadmem;
480c485
< mark(L);
---
> size_t deadmem = mark(L);
482c487
< checkSizes(L);
---
> checkSizes(L, deadmem);
tostring.
Example:
print{} -- on an AS400 machine
Patch:
liolib.c: 178c178 < char buff[32]; --- > char buff[128]; lbaselib.c: 327c327 < char buff[64]; --- > char buff[128];
local function does not increment stack size.
Example:
-- must run this with precompiled code local a,b,c local function d () end
Patch:
lparser.c: 1143a1144 > FuncState *fs = ls->fs; 1145c1146,1147 < init_exp(&v, VLOCAL, ls->fs->freereg ); --- > init_exp(&v, VLOCAL, fs->freereg); > luaK_reserveregs(fs, 1); 1148c1150,1152 < luaK_storevar(ls->fs, &v, &b); --- > luaK_storevar(fs, &v, &b); > /* debug information will only see the variable after this point! */ > getlocvar(fs, fs->nactvar - 1).startpc = fs->pc;
Example:
Set your hooks as below.
It is weird to use a positive count without setting the count hook,
but it is not wrong.
lua_sethook(L, my_hook, LUA_MASKLINE | LUA_MASKRET, 1);
Patch:
lvm.c:
69c69
< if (mask > LUA_MASKLINE) { /* instruction-hook set? */
---
> if (mask & LUA_MASKCOUNT) { /* instruction-hook set? */
dofile eats one return value when called without arguments.
Example:
a,b = dofile() --< here you enter `return 1,2,3 <eof>' print(a,b) --> 2 3 (should be 1 and 2)
Patch:
lbaselib.c: 313a314 > int n = lua_gettop(L); 317c318 < return lua_gettop(L) - 1; --- > return lua_gettop(L) - n;
lua_getupvalue and lua_setupvalue do not check for index too small.
rawset and rawget do not ignore extra arguments.
Most bugs in Lua 4.0 have been fixed in Lua 4.0.1 and later versions.
lua_pushuserdata(L,NULL) does not work.
while 1 dostring[[print('hello\n')]] end never reclaims memory.
ULONG_MAX>>10 may not fit into an int.