Fix overflow in unpacking timestamp to datetime (msgpack#452)

methane · web-flow · commit 753b3706d80a · 2020-12-18T14:21:27.000+09:00
diff --git a/msgpack/unpack.h b/msgpack/unpack.h
@@ -342,21 +342,21 @@ static int unpack_callback_ext(unpack_user* u, const char* base, const char* pos
             py = PyObject_CallFunction(u->timestamp_t, "(Lk)", ts.tv_sec, ts.tv_nsec);
         }
         else if (u->timestamp == 3) {  // datetime
-            // Calculate datetime using epoch + delta 
+            // Calculate datetime using epoch + delta
             // due to limitations PyDateTime_FromTimestamp on Windows with negative timestamps
             PyObject *epoch = PyDateTimeAPI->DateTime_FromDateAndTime(1970, 1, 1, 0, 0, 0, 0, u->utc, PyDateTimeAPI->DateTimeType);
             if (epoch == NULL) {
                 return -1;
             }
 
-            PyObject* d = PyDelta_FromDSU(0, ts.tv_sec, ts.tv_nsec / 1000);
+            PyObject* d = PyDelta_FromDSU(ts.tv_sec/(24*3600), ts.tv_sec%(24*3600), ts.tv_nsec / 1000);
             if (d == NULL) {
                 Py_DECREF(epoch);
                 return -1;
             }
 
             py = PyNumber_Add(epoch, d);
-            
+
             Py_DECREF(epoch);
             Py_DECREF(d);
         }
diff --git a/test/test_timestamp.py b/test/test_timestamp.py
@@ -129,3 +129,14 @@ def test_pack_datetime():
     assert x
     assert x[0] == dt
     assert msgpack.unpackb(packed) is None
+
+
+@pytest.mark.skipif(sys.version_info[0] == 2, reason="datetime support is PY3+ only")
+def test_issue451():
+    # https://github.com/msgpack/msgpack-python/issues/451
+    dt = datetime.datetime(2100, 1, 1, 1, 1, tzinfo=_utc)
+    packed = msgpack.packb(dt, datetime=True)
+    assert packed == b"\xd6\xff\xf4\x86eL"
+
+    unpacked = msgpack.unpackb(packed, timestamp=3)
+    assert dt == unpacked

Original file line number	Diff line number	Diff line change
`@@ -342,21 +342,21 @@ static int unpack_callback_ext(unpack_user* u, const char* base, const char* pos`
`342`	`342`	`py = PyObject_CallFunction(u->timestamp_t, "(Lk)", ts.tv_sec, ts.tv_nsec);`
`343`	`343`	`}`
`344`	`344`	`else if (u->timestamp == 3) { // datetime`
`345`		`- // Calculate datetime using epoch + delta`
	`345`	`+ // Calculate datetime using epoch + delta`
`346`	`346`	`// due to limitations PyDateTime_FromTimestamp on Windows with negative timestamps`
`347`	`347`	`PyObject *epoch = PyDateTimeAPI->DateTime_FromDateAndTime(1970, 1, 1, 0, 0, 0, 0, u->utc, PyDateTimeAPI->DateTimeType);`
`348`	`348`	`if (epoch == NULL) {`
`349`	`349`	`return -1;`
`350`	`350`	`}`
`351`	`351`
`352`		`- PyObject* d = PyDelta_FromDSU(0, ts.tv_sec, ts.tv_nsec / 1000);`
	`352`	`+ PyObject* d = PyDelta_FromDSU(ts.tv_sec/(243600), ts.tv_sec%(243600), ts.tv_nsec / 1000);`
`353`	`353`	`if (d == NULL) {`
`354`	`354`	`Py_DECREF(epoch);`
`355`	`355`	`return -1;`
`356`	`356`	`}`
`357`	`357`
`358`	`358`	`py = PyNumber_Add(epoch, d);`
`359`		`-`
	`359`	`+`
`360`	`360`	`Py_DECREF(epoch);`
`361`	`361`	`Py_DECREF(d);`
`362`	`362`	`}`