Issue #17671: Fixed a crash when use non-initialized io.BufferedRWPair.

Based on patch by Stephen Tu.

diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index bc59af399d130f8ca37b596b1228a27b88f50533..936dbed64a47a421d0540404a74f4072946830ac 100644 (file)
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -793,6 +793,16 @@ class BufferedReaderTest(unittest.TestCase, CommonBufferedTests):
         bufio.__init__(rawio)
         self.assertEqual(b"abc", bufio.read())
 
+    def test_uninitialized(self):
+        bufio = self.tp.__new__(self.tp)
+        del bufio
+        bufio = self.tp.__new__(self.tp)
+        self.assertRaisesRegexp((ValueError, AttributeError),
+                                'uninitialized|has no attribute',
+                                bufio.read, 0)
+        bufio.__init__(self.MockRawIO())
+        self.assertEqual(bufio.read(0), b'')
+
     def test_read(self):
         for arg in (None, 7):
             rawio = self.MockRawIO((b"abc", b"d", b"efg"))
@@ -1029,6 +1039,16 @@ class BufferedWriterTest(unittest.TestCase, CommonBufferedTests):
         bufio.flush()
         self.assertEqual(b"".join(rawio._write_stack), b"abcghi")
 
+    def test_uninitialized(self):
+        bufio = self.tp.__new__(self.tp)
+        del bufio
+        bufio = self.tp.__new__(self.tp)
+        self.assertRaisesRegexp((ValueError, AttributeError),
+                                'uninitialized|has no attribute',
+                                bufio.write, b'')
+        bufio.__init__(self.MockRawIO())
+        self.assertEqual(bufio.write(b''), 0)
+
     def test_detach_flush(self):
         raw = self.MockRawIO()
         buf = self.tp(raw)
@@ -1313,6 +1333,20 @@ class BufferedRWPairTest(unittest.TestCase):
         pair = self.tp(self.MockRawIO(), self.MockRawIO())
         self.assertFalse(pair.closed)
 
+    def test_uninitialized(self):
+        pair = self.tp.__new__(self.tp)
+        del pair
+        pair = self.tp.__new__(self.tp)
+        self.assertRaisesRegexp((ValueError, AttributeError),
+                                'uninitialized|has no attribute',
+                                pair.read, 0)
+        self.assertRaisesRegexp((ValueError, AttributeError),
+                                'uninitialized|has no attribute',
+                                pair.write, b'')
+        pair.__init__(self.MockRawIO(), self.MockRawIO())
+        self.assertEqual(pair.read(0), b'')
+        self.assertEqual(pair.write(b''), 0)
+
     def test_detach(self):
         pair = self.tp(self.MockRawIO(), self.MockRawIO())
         self.assertRaises(self.UnsupportedOperation, pair.detach)
@@ -1440,6 +1474,10 @@ class BufferedRandomTest(BufferedReaderTest, BufferedWriterTest):
         BufferedReaderTest.test_constructor(self)
         BufferedWriterTest.test_constructor(self)
 
+    def test_uninitialized(self):
+        BufferedReaderTest.test_uninitialized(self)
+        BufferedWriterTest.test_uninitialized(self)
+
     def test_read_and_write(self):
         raw = self.MockRawIO((b"asdf", b"ghjk"))
         rw = self.tp(raw, 8)

diff --git a/Misc/NEWS b/Misc/NEWS
index d2ef384d0ba8eeef226ca33200b12d23b179331d..a823fa7692dcaabad2b1d1e94220219f944e5471 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -44,6 +44,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #17671: Fixed a crash when use non-initialized io.BufferedRWPair.
+  Based on patch by Stephen Tu.
+
 - Issue #20594: Avoid name clash with the libc function posix_close.
 
 - Issue #19856: shutil.move() failed to move a directory to other directory

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 411755c1ed4293c1f302dbb77f04723b516430d9..758edf4208718d50387ac401e1fc6c09570d33f7 100644 (file)
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -2129,9 +2129,14 @@ bufferedrwpair_dealloc(rwpair *self)
 static PyObject *
 _forward_call(buffered *self, const char *name, PyObject *args)
 {
-    PyObject *func = PyObject_GetAttrString((PyObject *)self, name);
-    PyObject *ret;
+    PyObject *func, *ret;
+    if (self == NULL) {
+        PyErr_SetString(PyExc_ValueError,
+                        "I/O operation on uninitialized object");
+        return NULL;
+    }
 
+    func = PyObject_GetAttrString((PyObject *)self, name);
     if (func == NULL) {
         PyErr_SetString(PyExc_AttributeError, name);
         return NULL;