diff options
Diffstat (limited to 'Objects/longobject.c')
| -rw-r--r-- | Objects/longobject.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/Objects/longobject.c b/Objects/longobject.c index 0701c494133..17274d01cec 100644 --- a/Objects/longobject.c +++ b/Objects/longobject.c @@ -36,7 +36,8 @@ medium_value(PyLongObject *x) #define IS_SMALL_INT(ival) (-_PY_NSMALLNEGINTS <= (ival) && (ival) < _PY_NSMALLPOSINTS) #define IS_SMALL_UINT(ival) ((ival) < _PY_NSMALLPOSINTS) -#define _MAX_STR_DIGITS_ERROR_FMT "Exceeds the limit (%d) for integer string conversion: value has %zd digits" +#define _MAX_STR_DIGITS_ERROR_FMT_TO_INT "Exceeds the limit (%d) for integer string conversion: value has %zd digits" +#define _MAX_STR_DIGITS_ERROR_FMT_TO_STR "Exceeds the limit (%d) for integer string conversion" static inline void _Py_DECREF_INT(PyLongObject *op) @@ -1726,6 +1727,23 @@ long_to_decimal_string_internal(PyObject *aa, size_a = Py_ABS(Py_SIZE(a)); negative = Py_SIZE(a) < 0; + /* quick and dirty pre-check for overflowing the decimal digit limit, + based on the inequality 10/3 >= log2(10) + + explanation in https://github.com/python/cpython/pull/96537 + */ + if (size_a >= 10 * _PY_LONG_MAX_STR_DIGITS_THRESHOLD + / (3 * PyLong_SHIFT) + 2) { + PyInterpreterState *interp = _PyInterpreterState_GET(); + int max_str_digits = interp->int_max_str_digits; + if ((max_str_digits > 0) && + (max_str_digits / (3 * PyLong_SHIFT) <= (size_a - 11) / 10)) { + PyErr_Format(PyExc_ValueError, _MAX_STR_DIGITS_ERROR_FMT_TO_STR, + max_str_digits); + return -1; + } + } + /* quick and dirty upper bound for the number of digits required to express a in base _PyLong_DECIMAL_BASE: @@ -1791,8 +1809,8 @@ long_to_decimal_string_internal(PyObject *aa, Py_ssize_t strlen_nosign = strlen - negative; if ((max_str_digits > 0) && (strlen_nosign > max_str_digits)) { Py_DECREF(scratch); - PyErr_Format(PyExc_ValueError, _MAX_STR_DIGITS_ERROR_FMT, - max_str_digits, strlen_nosign); + PyErr_Format(PyExc_ValueError, _MAX_STR_DIGITS_ERROR_FMT_TO_STR, + max_str_digits); return -1; } } @@ -2466,7 +2484,7 @@ digit beyond the first. PyInterpreterState *interp = _PyInterpreterState_GET(); int max_str_digits = interp->int_max_str_digits; if ((max_str_digits > 0) && (digits > max_str_digits)) { - PyErr_Format(PyExc_ValueError, _MAX_STR_DIGITS_ERROR_FMT, + PyErr_Format(PyExc_ValueError, _MAX_STR_DIGITS_ERROR_FMT_TO_INT, max_str_digits, digits); return NULL; } |