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bpo-31619: Fixed integer overflow in converting huge strings to int. #3884

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Merged
merged 1 commit into from
Dec 3, 2017
Merged

bpo-31619: Fixed integer overflow in converting huge strings to int. #3884

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14 changes: 11 additions & 3 deletions Objects/longobject.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2024,7 +2024,7 @@ long_from_binary_base(const char **str, int base, PyLongObject **res)
const char *p = *str;
const char *start = p;
char prev = 0;
int digits = 0;
Py_ssize_t digits = 0;
int bits_per_char;
Py_ssize_t n;
PyLongObject *z;
Expand Down Expand Up @@ -2267,8 +2267,9 @@ just 1 digit at the start, so that the copying code was exercised for every
digit beyond the first.
***/
twodigits c; /* current input character */
double fsize_z;
Py_ssize_t size_z;
int digits = 0;
Py_ssize_t digits = 0;
int i;
int convwidth;
twodigits convmultmax, convmult;
Expand Down Expand Up @@ -2330,7 +2331,14 @@ digit beyond the first.
* need to initialize z->ob_digit -- no slot is read up before
* being stored into.
*/
size_z = (Py_ssize_t)(digits * log_base_BASE[base]) + 1;
fsize_z = digits * log_base_BASE[base] + 1;
if (fsize_z > MAX_LONG_DIGITS) {
/* The same exception as in _PyLong_New(). */
PyErr_SetString(PyExc_OverflowError,
"too many digits in integer");
return NULL;
}
size_z = (Py_ssize_t)fsize_z;
/* Uncomment next line to test exceedingly rare copy code */
/* size_z = 1; */
assert(size_z > 0);
Expand Down