API asserts for illegal pops of to-be-closed variables

This commit is contained in:
Roberto Ierusalimschy 2024-03-11 14:05:06 -03:00
parent 7237eb3f1c
commit 65b07dd53d
5 changed files with 45 additions and 30 deletions

52
lapi.c
View File

@ -139,7 +139,7 @@ LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
int i;
if (from == to) return;
lua_lock(to);
api_checknelems(from, n);
api_checkpop(from, n);
api_check(from, G(from) == G(to), "moving among independent states");
api_check(from, to->ci->top.p - to->top.p >= n, "stack overflow");
from->top.p -= n;
@ -205,7 +205,6 @@ LUA_API void lua_settop (lua_State *L, int idx) {
api_check(L, -(idx+1) <= (L->top.p - (func + 1)), "invalid new top");
diff = idx + 1; /* will "subtract" index (as it is negative) */
}
api_check(L, L->tbclist.p < L->top.p, "previous pop of an unclosed slot");
newtop = L->top.p + diff;
if (diff < 0 && L->tbclist.p >= newtop) {
lua_assert(hastocloseCfunc(ci->nresults));
@ -253,6 +252,7 @@ LUA_API void lua_rotate (lua_State *L, int idx, int n) {
lua_lock(L);
t = L->top.p - 1; /* end of stack segment being rotated */
p = index2stack(L, idx); /* start of segment */
api_check(L, L->tbclist.p < p, "moving a to-be-closed slot");
api_check(L, (n >= 0 ? n : -n) <= (t - p + 1), "invalid 'n'");
m = (n >= 0 ? t - n : p - n - 1); /* end of prefix */
reverse(L, p, m); /* reverse the prefix with length 'n' */
@ -345,9 +345,9 @@ LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
LUA_API void lua_arith (lua_State *L, int op) {
lua_lock(L);
if (op != LUA_OPUNM && op != LUA_OPBNOT)
api_checknelems(L, 2); /* all other operations expect two operands */
api_checkpop(L, 2); /* all other operations expect two operands */
else { /* for unary operations, add fake 2nd operand */
api_checknelems(L, 1);
api_checkpop(L, 1);
setobjs2s(L, L->top.p, L->top.p - 1);
api_incr_top(L);
}
@ -611,17 +611,18 @@ LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
api_incr_top(L);
}
else {
int i;
CClosure *cl;
api_checknelems(L, n);
api_checkpop(L, n);
api_check(L, n <= MAXUPVAL, "upvalue index too large");
cl = luaF_newCclosure(L, n);
cl->f = fn;
L->top.p -= n;
while (n--) {
setobj2n(L, &cl->upvalue[n], s2v(L->top.p + n));
for (i = 0; i < n; i++) {
setobj2n(L, &cl->upvalue[i], s2v(L->top.p - n + i));
/* does not need barrier because closure is white */
lua_assert(iswhite(cl));
}
L->top.p -= n;
setclCvalue(L, s2v(L->top.p), cl);
api_incr_top(L);
luaC_checkGC(L);
@ -701,6 +702,7 @@ LUA_API int lua_gettable (lua_State *L, int idx) {
int hres;
TValue *t;
lua_lock(L);
api_checkpop(L, 1);
t = index2value(L, idx);
luaV_fastget(t, s2v(L->top.p - 1), s2v(L->top.p - 1), luaH_get, hres);
if (hres != HOK)
@ -751,13 +753,13 @@ l_sinline Table *gettable (lua_State *L, int idx) {
LUA_API int lua_rawget (lua_State *L, int idx) {
Table *t;
int hres;
lua_lock(L);
api_checknelems(L, 1);
api_checkpop(L, 1);
t = gettable(L, idx);
hres = luaH_get(t, s2v(L->top.p - 1), s2v(L->top.p - 1));
L->top.p--; /* remove key */
return finishrawget(L, hres);
if (luaH_get(t, s2v(L->top.p - 1), s2v(L->top.p - 1)) != HOK)
setnilvalue(s2v(L->top.p - 1));
lua_unlock(L);
return ttype(s2v(L->top.p - 1));
}
@ -851,7 +853,7 @@ LUA_API int lua_getiuservalue (lua_State *L, int idx, int n) {
static void auxsetstr (lua_State *L, const TValue *t, const char *k) {
int hres;
TString *str = luaS_new(L, k);
api_checknelems(L, 1);
api_checkpop(L, 1);
luaV_fastset(t, str, s2v(L->top.p - 1), hres, luaH_psetstr);
if (hres == HOK) {
luaV_finishfastset(L, t, s2v(L->top.p - 1));
@ -879,7 +881,7 @@ LUA_API void lua_settable (lua_State *L, int idx) {
TValue *t;
int hres;
lua_lock(L);
api_checknelems(L, 2);
api_checkpop(L, 2);
t = index2value(L, idx);
luaV_fastset(t, s2v(L->top.p - 2), s2v(L->top.p - 1), hres, luaH_pset);
if (hres == HOK) {
@ -902,7 +904,7 @@ LUA_API void lua_seti (lua_State *L, int idx, lua_Integer n) {
TValue *t;
int hres;
lua_lock(L);
api_checknelems(L, 1);
api_checkpop(L, 1);
t = index2value(L, idx);
luaV_fastseti(t, n, s2v(L->top.p - 1), hres);
if (hres == HOK)
@ -920,7 +922,7 @@ LUA_API void lua_seti (lua_State *L, int idx, lua_Integer n) {
static void aux_rawset (lua_State *L, int idx, TValue *key, int n) {
Table *t;
lua_lock(L);
api_checknelems(L, n);
api_checkpop(L, n);
t = gettable(L, idx);
luaH_set(L, t, key, s2v(L->top.p - 1));
invalidateTMcache(t);
@ -945,7 +947,7 @@ LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) {
LUA_API void lua_rawseti (lua_State *L, int idx, lua_Integer n) {
Table *t;
lua_lock(L);
api_checknelems(L, 1);
api_checkpop(L, 1);
t = gettable(L, idx);
luaH_setint(L, t, n, s2v(L->top.p - 1));
luaC_barrierback(L, obj2gco(t), s2v(L->top.p - 1));
@ -958,7 +960,7 @@ LUA_API int lua_setmetatable (lua_State *L, int objindex) {
TValue *obj;
Table *mt;
lua_lock(L);
api_checknelems(L, 1);
api_checkpop(L, 1);
obj = index2value(L, objindex);
if (ttisnil(s2v(L->top.p - 1)))
mt = NULL;
@ -998,7 +1000,7 @@ LUA_API int lua_setiuservalue (lua_State *L, int idx, int n) {
TValue *o;
int res;
lua_lock(L);
api_checknelems(L, 1);
api_checkpop(L, 1);
o = index2value(L, idx);
api_check(L, ttisfulluserdata(o), "full userdata expected");
if (!(cast_uint(n) - 1u < cast_uint(uvalue(o)->nuvalue)))
@ -1031,7 +1033,7 @@ LUA_API void lua_callk (lua_State *L, int nargs, int nresults,
lua_lock(L);
api_check(L, k == NULL || !isLua(L->ci),
"cannot use continuations inside hooks");
api_checknelems(L, nargs+1);
api_checkpop(L, nargs + 1);
api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
checkresults(L, nargs, nresults);
func = L->top.p - (nargs+1);
@ -1072,7 +1074,7 @@ LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
lua_lock(L);
api_check(L, k == NULL || !isLua(L->ci),
"cannot use continuations inside hooks");
api_checknelems(L, nargs+1);
api_checkpop(L, nargs + 1);
api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
checkresults(L, nargs, nresults);
if (errfunc == 0)
@ -1141,7 +1143,7 @@ LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data, int strip) {
ptrdiff_t otop = savestack(L, L->top.p); /* original top */
TValue *f = s2v(L->top.p - 1); /* function to be dumped */
lua_lock(L);
api_checknelems(L, 1);
api_checkpop(L, 1);
api_check(L, isLfunction(f), "Lua function expected");
status = luaU_dump(L, clLvalue(f)->p, writer, data, strip);
L->top.p = restorestack(L, otop); /* restore top */
@ -1244,7 +1246,7 @@ LUA_API int lua_error (lua_State *L) {
TValue *errobj;
lua_lock(L);
errobj = s2v(L->top.p - 1);
api_checknelems(L, 1);
api_checkpop(L, 1);
/* error object is the memory error message? */
if (ttisshrstring(errobj) && eqshrstr(tsvalue(errobj), G(L)->memerrmsg))
luaM_error(L); /* raise a memory error */
@ -1259,7 +1261,7 @@ LUA_API int lua_next (lua_State *L, int idx) {
Table *t;
int more;
lua_lock(L);
api_checknelems(L, 1);
api_checkpop(L, 1);
t = gettable(L, idx);
more = luaH_next(L, t, L->top.p - 1);
if (more)

14
lapi.h
View File

@ -29,8 +29,18 @@
/* Ensure the stack has at least 'n' elements */
#define api_checknelems(L,n) \
api_check(L, (n) < (L->top.p - L->ci->func.p), \
"not enough elements in the stack")
api_check(L, (n) < (L->top.p - L->ci->func.p), \
"not enough elements in the stack")
/* Ensure the stack has at least 'n' elements to be popped. (Some
** functions only update a slot after checking it for popping, but that
** is only an optimization for a pop followed by a push.)
*/
#define api_checkpop(L,n) \
api_check(L, (n) < L->top.p - L->ci->func.p && \
L->tbclist.p < L->top.p - (n), \
"not enough free elements in the stack")
/*

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@ -245,6 +245,7 @@ LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
lua_lock(L);
name = luaG_findlocal(L, ar->i_ci, n, &pos);
if (name) {
api_checkpop(L, 1);
setobjs2s(L, pos, L->top.p - 1);
L->top.p--; /* pop value */
}

5
ldo.c
View File

@ -767,6 +767,7 @@ static CallInfo *findpcall (lua_State *L) {
** coroutine error handler and should not kill the coroutine.)
*/
static int resume_error (lua_State *L, const char *msg, int narg) {
api_checkpop(L, narg);
L->top.p -= narg; /* remove args from the stack */
setsvalue2s(L, L->top.p, luaS_new(L, msg)); /* push error message */
api_incr_top(L);
@ -849,7 +850,7 @@ LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
return resume_error(L, "C stack overflow", nargs);
L->nCcalls++;
luai_userstateresume(L, nargs);
api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs);
api_checkpop(L, (L->status == LUA_OK) ? nargs + 1 : nargs);
status = luaD_rawrunprotected(L, resume, &nargs);
/* continue running after recoverable errors */
status = precover(L, status);
@ -878,7 +879,7 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
luai_userstateyield(L, nresults);
lua_lock(L);
ci = L->ci;
api_checknelems(L, nresults);
api_checkpop(L, nresults);
if (l_unlikely(!yieldable(L))) {
if (L != G(L)->mainthread)
luaG_runerror(L, "attempt to yield across a C-call boundary");

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@ -1193,7 +1193,8 @@ do
local a, b = pcall(T.makeCfunc[[
call 0 1 # create resource
toclose -1 # mark it to be closed
error # resource is the error object
pushvalue -1 # replicate it as error object
error # resource right after error object
]], newresource)
assert(a == false and b[1] == 11)
assert(#openresource == 0) -- was closed