From 979f31172890fcfa45e5e23c461b1517a49dbf3b Mon Sep 17 00:00:00 2001
From: Benjamin Peterson <benjamin@python.org>
Date: Sun, 15 Jun 2008 00:05:44 +0000
Subject: [PATCH] #3114 fix a bus error when deallocated exceptions were used
---
Lib/test/test_exceptions.py | 19 +++++++++++++++++++
Python/ceval.c | 12 ++++++------
2 files changed, 25 insertions(+), 6 deletions(-)
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index 55a57baee1..753e33bab3 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -5,6 +5,8 @@ import sys
import unittest
import pickle
import weakref
+import gc
+import traceback
from test.support import TESTFN, unlink, run_unittest
@@ -551,6 +553,23 @@ class ExceptionTests(unittest.TestCase):
del g
self.assertEquals(sys.exc_info()[0], TypeError)
+ def test_crash_3114(self):
+ # Bug #3114: in its destructor, MyObject retrieves a pointer to a
+ # deallocated exception instance or traceback.
+ class MyObject:
+ def __del__(self):
+ nonlocal e
+ e = sys.exc_info()
+ e = ()
+ try:
+ raise Exception(MyObject())
+ except:
+ pass
+ gc.collect()
+ [0]*10000
+ # Do something with the exception and its traceback
+ traceback.format_exception(*e)
+
def test_main():
run_unittest(ExceptionTests)
diff --git a/Python/ceval.c b/Python/ceval.c
index 6aaa52dc6b..4b1478433b 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -704,11 +704,11 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
PyObject *v = POP(); \
Py_XDECREF(v); \
} \
- Py_XDECREF(tstate->exc_type); \
+ Py_CLEAR(tstate->exc_type); \
+ Py_CLEAR(tstate->exc_value); \
+ Py_CLEAR(tstate->exc_traceback); \
tstate->exc_type = POP(); \
- Py_XDECREF(tstate->exc_value); \
tstate->exc_value = POP(); \
- Py_XDECREF(tstate->exc_traceback); \
tstate->exc_traceback = POP();
#define SAVE_EXC_STATE() \
@@ -716,9 +716,9 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
Py_XINCREF(tstate->exc_type); \
Py_XINCREF(tstate->exc_value); \
Py_XINCREF(tstate->exc_traceback); \
- Py_XDECREF(f->f_exc_type); \
- Py_XDECREF(f->f_exc_value); \
- Py_XDECREF(f->f_exc_traceback); \
+ Py_CLEAR(f->f_exc_type); \
+ Py_CLEAR(f->f_exc_value); \
+ Py_CLEAR(f->f_exc_traceback); \
f->f_exc_type = tstate->exc_type; \
f->f_exc_value = tstate->exc_value; \
f->f_exc_traceback = tstate->exc_traceback; \
--
2.49.0