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| author | Gregory P. Smith <greg@krypto.org> | 2018-08-25 01:08:50 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2018-08-25 01:08:50 (GMT) |
| commit | 76be0fffff8b7dbe649ad4821144461800ffb0d0 (patch) | |
| tree | 9ef8e6646a08ddf8ae63a2600945b3c47f3ab79b | |
| parent | eb746dbae8b320758ee08f811316d7f283435cc0 (diff) | |
| download | cpython-76be0fffff8b7dbe649ad4821144461800ffb0d0.zip cpython-76be0fffff8b7dbe649ad4821144461800ffb0d0.tar.gz cpython-76be0fffff8b7dbe649ad4821144461800ffb0d0.tar.bz2 | |
bpo-13312: Avoid int underflow in time year. (GH-8912)
Avoids an integer underflow in the time module's year handling code.
| -rw-r--r-- | Lib/test/test_time.py | 11 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2018-08-24-17-31-27.bpo-13312.6hA5La.rst | 2 | ||||
| -rw-r--r-- | Modules/timemodule.c | 6 |
3 files changed, 13 insertions, 6 deletions
diff --git a/Lib/test/test_time.py b/Lib/test/test_time.py index 7354b96..9acd1d4 100644 --- a/Lib/test/test_time.py +++ b/Lib/test/test_time.py @@ -19,7 +19,7 @@ except ImportError: # Max year is only limited by the size of C int. SIZEOF_INT = sysconfig.get_config_var('SIZEOF_INT') or 4 TIME_MAXYEAR = (1 << 8 * SIZEOF_INT - 1) - 1 -TIME_MINYEAR = -TIME_MAXYEAR - 1 +TIME_MINYEAR = -TIME_MAXYEAR - 1 + 1900 SEC_TO_US = 10 ** 6 US_TO_NS = 10 ** 3 @@ -714,12 +714,11 @@ class _Test4dYear: self.assertEqual(self.yearstr(-123456), '-123456') self.assertEqual(self.yearstr(-123456789), str(-123456789)) self.assertEqual(self.yearstr(-1234567890), str(-1234567890)) - self.assertEqual(self.yearstr(TIME_MINYEAR + 1900), str(TIME_MINYEAR + 1900)) - # Issue #13312: it may return wrong value for year < TIME_MINYEAR + 1900 - # Skip the value test, but check that no error is raised - self.yearstr(TIME_MINYEAR) - # self.assertEqual(self.yearstr(TIME_MINYEAR), str(TIME_MINYEAR)) + self.assertEqual(self.yearstr(TIME_MINYEAR), str(TIME_MINYEAR)) + # Modules/timemodule.c checks for underflow self.assertRaises(OverflowError, self.yearstr, TIME_MINYEAR - 1) + with self.assertRaises(OverflowError): + self.yearstr(-TIME_MAXYEAR - 1) class TestAsctime4dyear(_TestAsctimeYear, _Test4dYear, unittest.TestCase): diff --git a/Misc/NEWS.d/next/Library/2018-08-24-17-31-27.bpo-13312.6hA5La.rst b/Misc/NEWS.d/next/Library/2018-08-24-17-31-27.bpo-13312.6hA5La.rst new file mode 100644 index 0000000..dc90669 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2018-08-24-17-31-27.bpo-13312.6hA5La.rst @@ -0,0 +1,2 @@ +Avoids a possible integer underflow (undefined behavior) in the time +module's year handling code when passed a very low negative year value. diff --git a/Modules/timemodule.c b/Modules/timemodule.c index 998216c..dbe2fba 100644 --- a/Modules/timemodule.c +++ b/Modules/timemodule.c @@ -551,6 +551,12 @@ gettmarg(PyObject *args, struct tm *p, const char *format) &p->tm_hour, &p->tm_min, &p->tm_sec, &p->tm_wday, &p->tm_yday, &p->tm_isdst)) return 0; + + if (y < INT_MIN + 1900) { + PyErr_SetString(PyExc_OverflowError, "year out of range"); + return 0; + } + p->tm_year = y - 1900; p->tm_mon--; p->tm_wday = (p->tm_wday + 1) % 7; |