From 671360161f0b7a5ff4c1d062e570962e851b4bde Mon Sep 17 00:00:00 2001 From: kcatss Date: Thu, 15 Feb 2024 01:08:26 +0900 Subject: [PATCH] gh-115243: Fix crash in deque.index() when the deque is concurrently modified (GH-115247) --- Lib/test/test_deque.py | 6 +++++- .../Security/2024-02-12-00-33-01.gh-issue-115243.e1oGX8.rst | 1 + Modules/_collectionsmodule.c | 3 ++- 3 files changed, 8 insertions(+), 2 deletions(-) create mode 100644 Misc/NEWS.d/next/Security/2024-02-12-00-33-01.gh-issue-115243.e1oGX8.rst diff --git a/Lib/test/test_deque.py b/Lib/test/test_deque.py index ae1dfacd726..4679f297fd7 100644 --- a/Lib/test/test_deque.py +++ b/Lib/test/test_deque.py @@ -166,7 +166,7 @@ class TestBasic(unittest.TestCase): with self.assertRaises(RuntimeError): n in d - def test_contains_count_stop_crashes(self): + def test_contains_count_index_stop_crashes(self): class A: def __eq__(self, other): d.clear() @@ -178,6 +178,10 @@ class TestBasic(unittest.TestCase): with self.assertRaises(RuntimeError): _ = d.count(3) + d = deque([A()]) + with self.assertRaises(RuntimeError): + d.index(0) + def test_extend(self): d = deque('a') self.assertRaises(TypeError, d.extend, 1) diff --git a/Misc/NEWS.d/next/Security/2024-02-12-00-33-01.gh-issue-115243.e1oGX8.rst b/Misc/NEWS.d/next/Security/2024-02-12-00-33-01.gh-issue-115243.e1oGX8.rst new file mode 100644 index 00000000000..ae0e910c7d1 --- /dev/null +++ b/Misc/NEWS.d/next/Security/2024-02-12-00-33-01.gh-issue-115243.e1oGX8.rst @@ -0,0 +1 @@ +Fix possible crashes in :meth:`collections.deque.index` when the deque is concurrently modified. diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c index ef77d34b10e..4fa76d62bc3 100644 --- a/Modules/_collectionsmodule.c +++ b/Modules/_collectionsmodule.c @@ -1218,8 +1218,9 @@ deque_index_impl(dequeobject *deque, PyObject *v, Py_ssize_t start, n = stop - i; while (--n >= 0) { CHECK_NOT_END(b); - item = b->data[index]; + item = Py_NewRef(b->data[index]); cmp = PyObject_RichCompareBool(item, v, Py_EQ); + Py_DECREF(item); if (cmp > 0) return PyLong_FromSsize_t(stop - n - 1); if (cmp < 0)