From 4af03c5ae10cfae115069dc5de8ec13b771df749 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Sat, 4 Jul 2015 13:35:14 -0300
Subject: better treatment for integer overflows + all errors throw an error
(instead of returning nil)
---
loslib.c | 60 +++++++++++++++++++++++++++++++++++++-----------------------
1 file changed, 37 insertions(+), 23 deletions(-)
diff --git a/loslib.c b/loslib.c
index bf436b81..eb444bb2 100644
--- a/loslib.c
+++ b/loslib.c
@@ -1,5 +1,5 @@
/*
-** $Id: loslib.c,v 1.56 2015/02/09 17:41:54 roberto Exp roberto $
+** $Id: loslib.c,v 1.57 2015/04/10 17:41:04 roberto Exp roberto $
** Standard Operating System library
** See Copyright Notice in lua.h
*/
@@ -54,7 +54,12 @@
*/
#define l_timet lua_Integer
#define l_pushtime(L,t) lua_pushinteger(L,(lua_Integer)(t))
-#define l_checktime(L,a) ((time_t)luaL_checkinteger(L,a))
+
+static time_t l_checktime (lua_State *L, int arg) {
+ lua_Integer t = luaL_checkinteger(L, arg);
+ luaL_argcheck(L, (time_t)t == t, arg, "time out-of-bounds");
+ return (time_t)t;
+}
#endif /* } */
@@ -198,17 +203,29 @@ static int getboolfield (lua_State *L, const char *key) {
}
-static int getfield (lua_State *L, const char *key, int d) {
- int res, isnum;
- lua_getfield(L, -1, key);
- res = (int)lua_tointegerx(L, -1, &isnum);
- if (!isnum) {
- if (d < 0)
+/* maximum value for date fields (to avoid arithmetic overflows with 'int') */
+#if !defined(L_MAXDATEFIELD)
+#define L_MAXDATEFIELD (INT_MAX / 2)
+#endif
+
+static int getfield (lua_State *L, const char *key, int d, int delta) {
+ int isnum;
+ int t = lua_getfield(L, -1, key);
+ lua_Integer res = lua_tointegerx(L, -1, &isnum);
+ if (!isnum) { /* field is not a number? */
+ if (t != LUA_TNIL) /* some other value? */
+ return luaL_error(L, "field '%s' not an integer", key);
+ else if (d < 0) /* abssent field; no default? */
return luaL_error(L, "field '%s' missing in date table", key);
res = d;
}
+ else {
+ if (!(-L_MAXDATEFIELD <= res && res <= L_MAXDATEFIELD))
+ return luaL_error(L, "field '%s' out-of-bounds", key);
+ res -= delta;
+ }
lua_pop(L, 1);
- return res;
+ return (int)res;
}
@@ -247,8 +264,8 @@ static int os_date (lua_State *L) {
else
stm = l_localtime(&t, &tmr);
if (stm == NULL) /* invalid date? */
- lua_pushnil(L);
- else if (strcmp(s, "*t") == 0) {
+ luaL_error(L, "time result cannot be represented in this installation");
+ if (strcmp(s, "*t") == 0) {
lua_createtable(L, 0, 9); /* 9 = number of fields */
setfield(L, "sec", stm->tm_sec);
setfield(L, "min", stm->tm_min);
@@ -290,21 +307,18 @@ static int os_time (lua_State *L) {
struct tm ts;
luaL_checktype(L, 1, LUA_TTABLE);
lua_settop(L, 1); /* make sure table is at the top */
- ts.tm_sec = getfield(L, "sec", 0);
- ts.tm_min = getfield(L, "min", 0);
- ts.tm_hour = getfield(L, "hour", 12);
- ts.tm_mday = getfield(L, "day", -1);
- ts.tm_mon = getfield(L, "month", -1) - 1;
- ts.tm_year = getfield(L, "year", -1) - 1900;
+ ts.tm_sec = getfield(L, "sec", 0, 0);
+ ts.tm_min = getfield(L, "min", 0, 0);
+ ts.tm_hour = getfield(L, "hour", 12, 0);
+ ts.tm_mday = getfield(L, "day", -1, 0);
+ ts.tm_mon = getfield(L, "month", -1, 1);
+ ts.tm_year = getfield(L, "year", -1, 1900);
ts.tm_isdst = getboolfield(L, "isdst");
t = mktime(&ts);
}
- if (t != (time_t)(l_timet)t)
- luaL_error(L, "time result cannot be represented in this Lua installation");
- else if (t == (time_t)(-1))
- lua_pushnil(L);
- else
- l_pushtime(L, t);
+ if (t != (time_t)(l_timet)t || t == (time_t)(-1))
+ luaL_error(L, "time result cannot be represented in this installation");
+ l_pushtime(L, t);
return 1;
}
--
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