[2.7] bpo-31752: Fix possible crash in timedelta constructor called with custom integers. (GH-3947) (#4088)
Bad remainder in divmod() in intermediate calculations caused an assertion failure..
(cherry picked from commit 4ffd4653a7ec9c97775472276cf5e159e2366bb2)
diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py
index 20abe74..f56c3f5 100644
--- a/Lib/test/test_datetime.py
+++ b/Lib/test/test_datetime.py
@@ -492,6 +492,46 @@
self.assertEqual(str(t3), str(t4))
self.assertEqual(t4.as_hours(), -1)
+ def test_issue31752(self):
+ # The interpreter shouldn't crash because divmod() returns negative
+ # remainder.
+ class BadInt(int):
+ def __mul__(self, other):
+ return Prod()
+
+ class BadLong(long):
+ 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))
+ timedelta(microseconds=BadLong(1))
+ timedelta(hours=BadLong(1))
+ timedelta(weeks=BadLong(1))
+
+ class Sum(long):
+ def __divmod__(self, other):
+ # negative remainder
+ return (0, -1)
+
+ timedelta(microseconds=BadInt(1))
+ timedelta(hours=BadInt(1))
+ timedelta(weeks=BadInt(1))
+ timedelta(microseconds=BadLong(1))
+ timedelta(hours=BadLong(1))
+ timedelta(weeks=BadLong(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 0000000..4ec140b
--- /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 34b8ed4..e818c5c 100644
--- a/Modules/datetimemodule.c
+++ b/Modules/datetimemodule.c
@@ -1537,6 +1537,7 @@
if (x2 == NULL)
goto Done;
result = PyNumber_Add(x1, x2);
+ assert(result == NULL || PyInt_CheckExact(result) || PyLong_CheckExact(result));
Done:
Py_XDECREF(x1);
@@ -1559,6 +1560,7 @@
PyObject *num = NULL;
PyObject *result = NULL;
+ assert(PyInt_CheckExact(pyus) || PyLong_CheckExact(pyus));
tuple = PyNumber_Divmod(pyus, us_per_second);
if (tuple == NULL)
goto Done;
@@ -1851,11 +1853,13 @@
assert(num != NULL);
if (PyInt_Check(num) || PyLong_Check(num)) {
- prod = PyNumber_Multiply(num, factor);
+ prod = PyNumber_Multiply(factor, num);
if (prod == NULL)
return NULL;
+ assert(PyInt_CheckExact(prod) || PyLong_CheckExact(prod));
sum = PyNumber_Add(sofar, prod);
Py_DECREF(prod);
+ assert(sum == NULL || PyInt_CheckExact(sum) || PyLong_CheckExact(sum));
return sum;
}
@@ -1898,7 +1902,7 @@
* fractional part requires float arithmetic, and may
* lose a little info.
*/
- assert(PyInt_Check(factor) || PyLong_Check(factor));
+ assert(PyInt_CheckExact(factor) || PyLong_CheckExact(factor));
if (PyInt_Check(factor))
dnum = (double)PyInt_AsLong(factor);
else
@@ -1916,6 +1920,7 @@
Py_DECREF(sum);
Py_DECREF(x);
*leftover += fracpart;
+ assert(y == NULL || PyInt_CheckExact(y) || PyLong_CheckExact(y));
return y;
}