Fix potential integer overflow in getnum (#3633)

This commit is contained in:
Yiheng Cao 2024-02-18 18:18:07 +08:00 committed by Marcel Stör
parent 6038307bbf
commit 1c3cc2b6a4
1 changed files with 6 additions and 4 deletions

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@ -99,12 +99,14 @@ typedef struct Header {
} Header; } Header;
static int getnum (const char **fmt, int df) { static int getnum (lua_State *L, const char **fmt, int df) {
if (!isdigit(**fmt)) /* no number? */ if (!isdigit(**fmt)) /* no number? */
return df; /* return default value */ return df; /* return default value */
else { else {
int a = 0; int a = 0;
do { do {
if (a > (INT_MAX / 10) || a * 10 > (INT_MAX - (**fmt - '0')))
luaL_error(L, "integral size overflow");
a = a*10 + *((*fmt)++) - '0'; a = a*10 + *((*fmt)++) - '0';
} while (isdigit(**fmt)); } while (isdigit(**fmt));
return a; return a;
@ -127,9 +129,9 @@ static size_t optsize (lua_State *L, char opt, const char **fmt) {
case 'd': return sizeof(double); case 'd': return sizeof(double);
#endif #endif
case 'x': return 1; case 'x': return 1;
case 'c': return getnum(fmt, 1); case 'c': return getnum(L, fmt, 1);
case 'i': case 'I': { case 'i': case 'I': {
int sz = getnum(fmt, sizeof(int)); int sz = getnum(L, fmt, sizeof(int));
if (sz > MAXINTSIZE) if (sz > MAXINTSIZE)
luaL_error(L, "integral size %d is larger than limit of %d", luaL_error(L, "integral size %d is larger than limit of %d",
sz, MAXINTSIZE); sz, MAXINTSIZE);
@ -162,7 +164,7 @@ static void controloptions (lua_State *L, int opt, const char **fmt,
case '>': h->endian = BIG; return; case '>': h->endian = BIG; return;
case '<': h->endian = LITTLE; return; case '<': h->endian = LITTLE; return;
case '!': { case '!': {
int a = getnum(fmt, MAXALIGN); int a = getnum(L, fmt, MAXALIGN);
if (!isp2(a)) if (!isp2(a))
luaL_error(L, "alignment %d is not a power of 2", a); luaL_error(L, "alignment %d is not a power of 2", a);
h->align = a; h->align = a;