Issue #15989: Fix several occurrences of integer overflow

when result of PyInt_AsLong() or PyLong_AsLong() narrowed
to int without checks.

This is a backport of changesets 13e2e44db99d and 525407d89277.

Include/intobject.h

@@ -40,6 +40,7 @@ PyAPI_FUNC(PyObject *) PyInt_FromSize_t(size_t);
 PyAPI_FUNC(PyObject *) PyInt_FromSsize_t(Py_ssize_t);
 PyAPI_FUNC(long) PyInt_AsLong(PyObject *);
 PyAPI_FUNC(Py_ssize_t) PyInt_AsSsize_t(PyObject *);
+PyAPI_FUNC(int) _PyInt_AsInt(PyObject *);
 PyAPI_FUNC(unsigned long) PyInt_AsUnsignedLongMask(PyObject *);
 #ifdef HAVE_LONG_LONG
 PyAPI_FUNC(unsigned PY_LONG_LONG) PyInt_AsUnsignedLongLongMask(PyObject *);

Include/longobject.h

@@ -25,6 +25,7 @@ PyAPI_FUNC(long) PyLong_AsLongAndOverflow(PyObject *, int *);
 PyAPI_FUNC(unsigned long) PyLong_AsUnsignedLong(PyObject *);
 PyAPI_FUNC(unsigned long) PyLong_AsUnsignedLongMask(PyObject *);
 PyAPI_FUNC(Py_ssize_t) PyLong_AsSsize_t(PyObject *);
+PyAPI_FUNC(int) _PyLong_AsInt(PyObject *);
 PyAPI_FUNC(PyObject *) PyLong_GetInfo(void);
 
 /* For use by intobject.c only */

Lib/ctypes/test/test_structures.py

@@ -1,6 +1,7 @@
 import unittest
 from ctypes import *
 from struct import calcsize
+import _testcapi
 
 class SubclassesTest(unittest.TestCase):
     def test_subclass(self):
@@ -199,6 +200,14 @@ class X(Structure):
              "_pack_": -1}
         self.assertRaises(ValueError, type(Structure), "X", (Structure,), d)
 
+        # Issue 15989
+        d = {"_fields_": [("a", c_byte)],
+             "_pack_": _testcapi.INT_MAX + 1}
+        self.assertRaises(ValueError, type(Structure), "X", (Structure,), d)
+        d = {"_fields_": [("a", c_byte)],
+             "_pack_": _testcapi.UINT_MAX + 2}
+        self.assertRaises(ValueError, type(Structure), "X", (Structure,), d)
+
     def test_initializers(self):
         class Person(Structure):
             _fields_ = [("name", c_char*6),

Lib/test/string_tests.py

@@ -5,6 +5,7 @@
 import unittest, string, sys, struct
 from test import test_support
 from UserList import UserList
+import _testcapi
 
 class Sequence:
     def __init__(self, seq='wxyz'): self.seq = seq
@@ -1113,6 +1114,20 @@ def test_formatting(self):
         self.checkraises(TypeError, '%10.*f', '__mod__', ('foo', 42.))
         self.checkraises(ValueError, '%10', '__mod__', (42,))
 
+        if _testcapi.PY_SSIZE_T_MAX < sys.maxint:
+            self.checkraises(OverflowError, '%*s', '__mod__',
+                            (_testcapi.PY_SSIZE_T_MAX + 1, ''))
+        if _testcapi.INT_MAX < sys.maxint:
+            self.checkraises(OverflowError, '%.*f', '__mod__',
+                            (_testcapi.INT_MAX + 1, 1. / 7))
+        # Issue 15989
+        if 1 << (_testcapi.PY_SSIZE_T_MAX.bit_length() + 1) <= sys.maxint:
+            self.checkraises(OverflowError, '%*s', '__mod__',
+                            (1 << (_testcapi.PY_SSIZE_T_MAX.bit_length() + 1), ''))
+        if _testcapi.UINT_MAX < sys.maxint:
+            self.checkraises(OverflowError, '%.*f', '__mod__',
+                            (_testcapi.UINT_MAX + 1, 1. / 7))
+
         class X(object): pass
         self.checkraises(TypeError, 'abc', '__mod__', X())
 

Lib/test/test_fcntl.py

@@ -6,6 +6,7 @@
 import os
 import struct
 import sys
+import _testcapi
 import unittest
 from test.test_support import (verbose, TESTFN, unlink, run_unittest,
     import_module)
@@ -81,6 +82,26 @@ def test_fcntl_file_descriptor(self):
             rv = fcntl.fcntl(self.f, fcntl.F_SETLKW, lockdata)
         self.f.close()
 
+    def test_fcntl_bad_file(self):
+        class F:
+            def __init__(self, fn):
+                self.fn = fn
+            def fileno(self):
+                return self.fn
+        self.assertRaises(ValueError, fcntl.fcntl, -1, fcntl.F_SETFL, os.O_NONBLOCK)
+        self.assertRaises(ValueError, fcntl.fcntl, F(-1), fcntl.F_SETFL, os.O_NONBLOCK)
+        self.assertRaises(TypeError, fcntl.fcntl, 'spam', fcntl.F_SETFL, os.O_NONBLOCK)
+        self.assertRaises(TypeError, fcntl.fcntl, F('spam'), fcntl.F_SETFL, os.O_NONBLOCK)
+        # Issue 15989
+        self.assertRaises(ValueError, fcntl.fcntl, _testcapi.INT_MAX + 1,
+                                                   fcntl.F_SETFL, os.O_NONBLOCK)
+        self.assertRaises(ValueError, fcntl.fcntl, F(_testcapi.INT_MAX + 1),
+                                                   fcntl.F_SETFL, os.O_NONBLOCK)
+        self.assertRaises(ValueError, fcntl.fcntl, _testcapi.INT_MIN - 1,
+                                                   fcntl.F_SETFL, os.O_NONBLOCK)
+        self.assertRaises(ValueError, fcntl.fcntl, F(_testcapi.INT_MIN - 1),
+                                                   fcntl.F_SETFL, os.O_NONBLOCK)
+
     def test_fcntl_64_bit(self):
         # Issue #1309352: fcntl shouldn't fail when the third arg fits in a
         # C 'long' but not in a C 'int'.

Lib/test/test_fileio.py

@@ -10,6 +10,7 @@
 from weakref import proxy
 from functools import wraps
 from UserList import UserList
+import _testcapi
 
 from test.test_support import TESTFN, check_warnings, run_unittest, make_bad_fd
 from test.test_support import py3k_bytes as bytes
@@ -343,6 +344,9 @@ def testInvalidFd(self):
         if sys.platform == 'win32':
             import msvcrt
             self.assertRaises(IOError, msvcrt.get_osfhandle, make_bad_fd())
+        # Issue 15989
+        self.assertRaises(TypeError, _FileIO, _testcapi.INT_MAX + 1)
+        self.assertRaises(TypeError, _FileIO, _testcapi.INT_MIN - 1)
 
     def testBadModeArgument(self):
         # verify that we get a sensible error message for bad mode argument

Lib/test/test_poll.py

@@ -1,6 +1,7 @@
 # Test case for the os.poll() function
 
 import os, select, random, unittest
+import _testcapi
 from test.test_support import TESTFN, run_unittest
 
 try:
@@ -150,6 +151,15 @@ def test_poll3(self):
         if x != 5:
             self.fail('Overflow must have occurred')
 
+        pollster = select.poll()
+        # Issue 15989
+        self.assertRaises(OverflowError, pollster.register, 0,
+                          _testcapi.SHRT_MAX + 1)
+        self.assertRaises(OverflowError, pollster.register, 0,
+                          _testcapi.USHRT_MAX + 1)
+        self.assertRaises(OverflowError, pollster.poll, _testcapi.INT_MAX + 1)
+        self.assertRaises(OverflowError, pollster.poll, _testcapi.UINT_MAX + 1)
+
 def test_main():
     run_unittest(PollTests)
 

Lib/test/test_socket.py

@@ -6,6 +6,7 @@
 import errno
 import socket
 import select
+import _testcapi
 import time
 import traceback
 import Queue
@@ -700,11 +701,17 @@ def test_sendall_interrupted(self):
     def test_sendall_interrupted_with_timeout(self):
         self.check_sendall_interrupted(True)
 
-    def testListenBacklog0(self):
+    def test_listen_backlog(self):
+        for backlog in 0, -1:
+            srv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            srv.bind((HOST, 0))
+            srv.listen(backlog)
+            srv.close()
+
+        # Issue 15989
         srv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         srv.bind((HOST, 0))
-        # backlog = 0
-        srv.listen(0)
+        self.assertRaises(OverflowError, srv.listen, _testcapi.INT_MAX + 1)
         srv.close()
 
     @unittest.skipUnless(SUPPORTS_IPV6, 'IPv6 required for this test.')
@@ -808,6 +815,11 @@ def testShutdown(self):
 
     def _testShutdown(self):
         self.serv_conn.send(MSG)
+        # Issue 15989
+        self.assertRaises(OverflowError, self.serv_conn.shutdown,
+                          _testcapi.INT_MAX + 1)
+        self.assertRaises(OverflowError, self.serv_conn.shutdown,
+                          2 + (_testcapi.UINT_MAX + 1))
         self.serv_conn.shutdown(2)
 
 @unittest.skipUnless(thread, 'Threading required for this test.')
@@ -883,14 +895,21 @@ def __init__(self, methodName='runTest'):
 
     def testSetBlocking(self):
         # Testing whether set blocking works
-        self.serv.setblocking(0)
+        self.serv.setblocking(True)
+        self.assertIsNone(self.serv.gettimeout())
+        self.serv.setblocking(False)
+        self.assertEqual(self.serv.gettimeout(), 0.0)
         start = time.time()
         try:
             self.serv.accept()
         except socket.error:
             pass
         end = time.time()
         self.assertTrue((end - start) < 1.0, "Error setting non-blocking mode.")
+        # Issue 15989
+        if _testcapi.UINT_MAX < _testcapi.ULONG_MAX:
+            self.serv.setblocking(_testcapi.UINT_MAX + 1)
+            self.assertIsNone(self.serv.gettimeout())
 
     def _testSetBlocking(self):
         pass

Modules/_ctypes/stgdict.c

@@ -343,7 +343,7 @@ PyCStructUnionType_update_stgdict(PyObject *type, PyObject *fields, int isStruct
 
     isPacked = PyObject_GetAttrString(type, "_pack_");
     if (isPacked) {
-        pack = PyInt_AsLong(isPacked);
+        pack = _PyInt_AsInt(isPacked);
         if (pack < 0 || PyErr_Occurred()) {
             Py_XDECREF(isPacked);
             PyErr_SetString(PyExc_ValueError,

Modules/_io/_iomodule.c

@@ -300,7 +300,8 @@ io_open(PyObject *self, PyObject *args, PyObject *kwds)
     int text = 0, binary = 0, universal = 0;
 
     char rawmode[5], *m;
-    int line_buffering, isatty;
+    int line_buffering;
+    long isatty;
 
     PyObject *raw, *modeobj = NULL, *buffer = NULL, *wrapper = NULL;
 
@@ -443,12 +444,12 @@ io_open(PyObject *self, PyObject *args, PyObject *kwds)
 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
         {
             struct stat st;
-            long fileno;
+            int fileno;
             PyObject *res = PyObject_CallMethod(raw, "fileno", NULL);
             if (res == NULL)
                 goto error;
 
-            fileno = PyInt_AsLong(res);
+            fileno = _PyInt_AsInt(res);
             Py_DECREF(res);
             if (fileno == -1 && PyErr_Occurred())
                 goto error;

Modules/_io/fileio.c

@@ -211,7 +211,7 @@ fileio_init(PyObject *oself, PyObject *args, PyObject *kwds)
         return -1;
     }
 
-    fd = PyLong_AsLong(nameobj);
+    fd = _PyLong_AsInt(nameobj);
     if (fd < 0) {
         if (!PyErr_Occurred()) {
             PyErr_SetString(PyExc_ValueError,

Modules/selectmodule.c

@@ -343,10 +343,13 @@ update_ufd_array(pollObject *self)
 
     i = pos = 0;
     while (PyDict_Next(self->dict, &pos, &key, &value)) {
-        self->ufds[i].fd = PyInt_AsLong(key);
+        assert(i < self->ufd_len);
+        /* Never overflow */
+        self->ufds[i].fd = (int)PyInt_AsLong(key);
         self->ufds[i].events = (short)PyInt_AsLong(value);
         i++;
     }
+    assert(i == self->ufd_len);
     self->ufd_uptodate = 1;
     return 1;
 }
@@ -362,10 +365,11 @@ static PyObject *
 poll_register(pollObject *self, PyObject *args)
 {
     PyObject *o, *key, *value;
-    int fd, events = POLLIN | POLLPRI | POLLOUT;
+    int fd;
+    short events = POLLIN | POLLPRI | POLLOUT;
     int err;
 
-    if (!PyArg_ParseTuple(args, "O|i:register", &o, &events)) {
+    if (!PyArg_ParseTuple(args, "O|h:register", &o, &events)) {
         return NULL;
     }
 
@@ -503,7 +507,7 @@ poll_poll(pollObject *self, PyObject *args)
         tout = PyNumber_Int(tout);
         if (!tout)
             return NULL;
-        timeout = PyInt_AsLong(tout);
+        timeout = _PyInt_AsInt(tout);
         Py_DECREF(tout);
         if (timeout == -1 && PyErr_Occurred())
             return NULL;

Modules/socketmodule.c

@@ -1713,7 +1713,7 @@ info is a pair (hostaddr, port).");
 static PyObject *
 sock_setblocking(PySocketSockObject *s, PyObject *arg)
 {
-    int block;
+    long block;
 
     block = PyInt_AsLong(arg);
     if (block == -1 && PyErr_Occurred())
@@ -2243,7 +2243,7 @@ sock_listen(PySocketSockObject *s, PyObject *arg)
     int backlog;
     int res;
 
-    backlog = PyInt_AsLong(arg);
+    backlog = _PyInt_AsInt(arg);
     if (backlog == -1 && PyErr_Occurred())
         return NULL;
     Py_BEGIN_ALLOW_THREADS
@@ -2894,7 +2894,7 @@ sock_shutdown(PySocketSockObject *s, PyObject *arg)
     int how;
     int res;
 
-    how = PyInt_AsLong(arg);
+    how = _PyInt_AsInt(arg);
     if (how == -1 && PyErr_Occurred())
         return NULL;
     Py_BEGIN_ALLOW_THREADS

Objects/fileobject.c

@@ -2659,10 +2659,10 @@ int PyObject_AsFileDescriptor(PyObject *o)
     PyObject *meth;
 
     if (PyInt_Check(o)) {
-        fd = PyInt_AsLong(o);
+        fd = _PyInt_AsInt(o);
     }
     else if (PyLong_Check(o)) {
-        fd = PyLong_AsLong(o);
+        fd = _PyLong_AsInt(o);
     }
     else if ((meth = PyObject_GetAttrString(o, "fileno")) != NULL)
     {
@@ -2672,11 +2672,11 @@ int PyObject_AsFileDescriptor(PyObject *o)
             return -1;
 
         if (PyInt_Check(fno)) {
-            fd = PyInt_AsLong(fno);
+            fd = _PyInt_AsInt(fno);
             Py_DECREF(fno);
         }
         else if (PyLong_Check(fno)) {
-            fd = PyLong_AsLong(fno);
+            fd = _PyLong_AsInt(fno);
             Py_DECREF(fno);
         }
         else {

Objects/intobject.c

@@ -189,6 +189,20 @@ PyInt_AsLong(register PyObject *op)
     return val;
 }
 
+int
+_PyInt_AsInt(PyObject *obj)
+{
+    long result = PyInt_AsLong(obj);
+    if (result == -1 && PyErr_Occurred())
+        return -1;
+    if (result > INT_MAX || result < INT_MIN) {
+        PyErr_SetString(PyExc_OverflowError,
+                        "Python int too large to convert to C int");
+        return -1;
+    }
+    return (int)result;
+}
+
 Py_ssize_t
 PyInt_AsSsize_t(register PyObject *op)
 {

Objects/longobject.c

@@ -339,6 +339,24 @@ PyLong_AsLong(PyObject *obj)
     return result;
 }
 
+/* Get a C int from a long int object or any object that has an __int__
+   method.  Return -1 and set an error if overflow occurs. */
+
+int
+_PyLong_AsInt(PyObject *obj)
+{
+    int overflow;
+    long result = PyLong_AsLongAndOverflow(obj, &overflow);
+    if (overflow || result > INT_MAX || result < INT_MIN) {
+        /* XXX: could be cute and give a different
+           message for overflow == -1 */
+        PyErr_SetString(PyExc_OverflowError,
+                        "Python int too large to convert to C int");
+        return -1;
+    }
+    return (int)result;
+}
+
 /* Get a Py_ssize_t from a long int object.
    Returns -1 and sets an error condition if overflow occurs. */