[Python-checkins] bpo-31752: Fix possible crash in timedelta constructor called with custom integers. (#3947)
Serhiy Storchaka
webhook-mailer at python.org
Mon Oct 23 10:12:35 EDT 2017
https://github.com/python/cpython/commit/4ffd4653a7ec9c97775472276cf5e159e2366bb2
commit: 4ffd4653a7ec9c97775472276cf5e159e2366bb2
branch: master
author: Serhiy Storchaka <storchaka at gmail.com>
committer: GitHub <noreply at github.com>
date: 2017-10-23T17:12:28+03:00
summary:
bpo-31752: Fix possible crash in timedelta constructor called with custom integers. (#3947)
Bad remainder in divmod() in intermediate calculations caused an assertion failure.
files:
A Misc/NEWS.d/next/Library/2017-10-11-00-45-01.bpo-31752.DhWevN.rst
M Lib/test/datetimetester.py
M Modules/_datetimemodule.c
diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index a042efd878b..4edfb42d355 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -886,6 +886,26 @@ def as_integer_ratio(self):
with self.assertRaises(ValueError):
timedelta() * get_bad_float(bad_ratio)
+ def test_issue31752(self):
+ # The interpreter shouldn't crash because divmod() returns negative
+ # remainder.
+ class BadInt(int):
+ def __mul__(self, other):
+ return Prod()
+
+ class Prod:
+ def __radd__(self, other):
+ return Sum()
+
+ class Sum(int):
+ def __divmod__(self, other):
+ # negative remainder
+ return (0, -1)
+
+ timedelta(microseconds=BadInt(1))
+ timedelta(hours=BadInt(1))
+ timedelta(weeks=BadInt(1))
+
#############################################################################
# date tests
diff --git a/Misc/NEWS.d/next/Library/2017-10-11-00-45-01.bpo-31752.DhWevN.rst b/Misc/NEWS.d/next/Library/2017-10-11-00-45-01.bpo-31752.DhWevN.rst
new file mode 100644
index 00000000000..4ec140b5361
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2017-10-11-00-45-01.bpo-31752.DhWevN.rst
@@ -0,0 +1 @@
+Fix possible crash in timedelta constructor called with custom integers.
diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index fc2cdba70c5..09b557958a0 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -1537,6 +1537,7 @@ delta_to_microseconds(PyDateTime_Delta *self)
if (x2 == NULL)
goto Done;
result = PyNumber_Add(x1, x2);
+ assert(result == NULL || PyLong_CheckExact(result));
Done:
Py_XDECREF(x1);
@@ -1559,6 +1560,7 @@ microseconds_to_delta_ex(PyObject *pyus, PyTypeObject *type)
PyObject *num = NULL;
PyObject *result = NULL;
+ assert(PyLong_CheckExact(pyus));
tuple = PyNumber_Divmod(pyus, us_per_second);
if (tuple == NULL)
goto Done;
@@ -2081,11 +2083,13 @@ accum(const char* tag, PyObject *sofar, PyObject *num, PyObject *factor,
assert(num != NULL);
if (PyLong_Check(num)) {
- prod = PyNumber_Multiply(num, factor);
+ prod = PyNumber_Multiply(factor, num);
if (prod == NULL)
return NULL;
+ assert(PyLong_CheckExact(prod));
sum = PyNumber_Add(sofar, prod);
Py_DECREF(prod);
+ assert(sum == NULL || PyLong_CheckExact(sum));
return sum;
}
@@ -2128,7 +2132,7 @@ accum(const char* tag, PyObject *sofar, PyObject *num, PyObject *factor,
* fractional part requires float arithmetic, and may
* lose a little info.
*/
- assert(PyLong_Check(factor));
+ assert(PyLong_CheckExact(factor));
dnum = PyLong_AsDouble(factor);
dnum *= fracpart;
@@ -2143,6 +2147,7 @@ accum(const char* tag, PyObject *sofar, PyObject *num, PyObject *factor,
Py_DECREF(sum);
Py_DECREF(x);
*leftover += fracpart;
+ assert(y == NULL || PyLong_CheckExact(y));
return y;
}
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