backport the security fix part of r67246

diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index a31a9f0cdf7ea4d9d23adf40fd1a449fd2a100d8..cd3d9526aad0e922a426331713251f85c71e792a 100644 (file)
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -4087,6 +4087,24 @@ def notimplemented():
                 check(iexpr, c, N1)
                 check(iexpr, c, N2)
 
+def test_lost_getattr():
+    # issue 4230
+    import gc
+    class EvilGetattribute(object):
+        def __getattr__(self, name):
+            raise AttributeError(name)
+        def __getattribute__(self, name):
+            del EvilGetattribute.__getattr__
+            for i in range(5):
+                gc.collect()
+            raise AttributeError(name)
+
+    try:
+        # This used to segfault
+        EvilGetattribute().attr
+    except AttributeError:
+        pass
+
 def test_main():
     weakref_segfault() # Must be first, somehow
     wrapper_segfault()
@@ -4183,6 +4201,7 @@ def test_main():
     vicious_descriptor_nonsense()
     test_init()
     notimplemented()
+    test_lost_getattr()
 
     if verbose: print "All OK"
 

diff --git a/Misc/NEWS b/Misc/NEWS
index 320e753ef5682d4d7d1ae15f10a96439679b0589..3d6a8014a08fdbe44351eb949ed51138d16ae07d 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@ What's New in Python 2.4.6c1?
 Core and builtins
 -----------------
 
+- Issue #4230: Fix a crash when a class has a custom __getattr__ and an
+  __getattribute__ method that deletes the __getattr__ attribute.
+
 - Apply security patches from Apple. CVE-2008-2315.
 
 - Issue #2620: Overflow checking when allocating or reallocating memory

diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 295634c0a831d610e3a66b9502865437c0da4c60..2618fb3ed285a7bdf6b19bcb9b0d5b6f586ea828 100644 (file)
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -4594,6 +4594,7 @@ slot_tp_getattr_hook(PyObject *self, PyObject *name)
                tp->tp_getattro = slot_tp_getattro;
                return slot_tp_getattro(self, name);
        }
+       Py_INCREF(getattr);
        getattribute = _PyType_Lookup(tp, getattribute_str);
        if (getattribute == NULL ||
            (getattribute->ob_type == &PyWrapperDescr_Type &&
@@ -4606,6 +4607,7 @@ slot_tp_getattr_hook(PyObject *self, PyObject *name)
                PyErr_Clear();
                res = PyObject_CallFunction(getattr, "OO", self, name);
        }
+       Py_DECREF(getattr);
        return res;
 }