From 4507e6456e6170f92e14d7ecb68f2617a3b48412 Mon Sep 17 00:00:00 2001 From: Jesus Cea Date: Wed, 21 Sep 2011 03:53:25 +0200 Subject: Close #13022: _multiprocessing.recvfd() doesn't check that file descriptor was actually received --- Lib/test/test_multiprocessing.py | 17 +++++++++++++++++ Misc/NEWS | 3 +++ Modules/_multiprocessing/multiprocessing.c | 11 +++++++++++ 3 files changed, 31 insertions(+) diff --git a/Lib/test/test_multiprocessing.py b/Lib/test/test_multiprocessing.py index 5d734ed..1d84ca8 100644 --- a/Lib/test/test_multiprocessing.py +++ b/Lib/test/test_multiprocessing.py @@ -1632,6 +1632,23 @@ class _TestConnection(BaseTestCase): with open(test.support.TESTFN, "rb") as f: self.assertEqual(f.read(), b"bar") + @classmethod + def _send_data_without_fd(self, conn): + os.write(conn.fileno(), b"\0") + + @unittest.skipIf(sys.platform == "win32", "doesn't make sense on Windows") + def test_missing_fd_transfer(self): + # Check that exception is raised when received data is not + # accompanied by a file descriptor in ancillary data. + if self.TYPE != 'processes': + self.skipTest("only makes sense with processes") + conn, child_conn = self.Pipe(duplex=True) + + p = self.Process(target=self._send_data_without_fd, args=(child_conn,)) + p.daemon = True + p.start() + self.assertRaises(RuntimeError, reduction.recv_handle, conn) + p.join() class _TestListenerClient(BaseTestCase): diff --git a/Misc/NEWS b/Misc/NEWS index 1d03385..6f4cb0a 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -78,6 +78,9 @@ Tests Extension Modules ----------------- +- Issue #13022: Fix: _multiprocessing.recvfd() doesn't check that + file descriptor was actually received. + - Issue #12483: ctypes: Fix a crash when the destruction of a callback object triggers the garbage collector. diff --git a/Modules/_multiprocessing/multiprocessing.c b/Modules/_multiprocessing/multiprocessing.c index bc635da..83df1eb 100644 --- a/Modules/_multiprocessing/multiprocessing.c +++ b/Modules/_multiprocessing/multiprocessing.c @@ -177,6 +177,17 @@ multiprocessing_recvfd(PyObject *self, PyObject *args) if (res < 0) return PyErr_SetFromErrno(PyExc_OSError); + if (msg.msg_controllen < CMSG_LEN(sizeof(int)) || + (cmsg = CMSG_FIRSTHDR(&msg)) == NULL || + cmsg->cmsg_level != SOL_SOCKET || + cmsg->cmsg_type != SCM_RIGHTS || + cmsg->cmsg_len < CMSG_LEN(sizeof(int))) { + /* If at least one control message is present, there should be + no room for any further data in the buffer. */ + PyErr_SetString(PyExc_RuntimeError, "No file descriptor received"); + return NULL; + } + fd = * (int *) CMSG_DATA(cmsg); return Py_BuildValue("i", fd); } -- cgit v0.12