From 05ac8952bc2b1546ed28b4d032a92583a1573e8d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marta=20G=C3=B3mez=20Mac=C3=ADas?= Date: Sun, 5 Mar 2023 12:00:41 +0100 Subject: [PATCH] gh-102356: Add thrashcan macros to filter object dealloc (GH-102426) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add thrashcan macros to the deallocator of the filter objects to protect against deeply nested destruction of chains of nested filters. (cherry picked from commit 66aa78cbe604a7c5731f074b869f92174a8e3b64) Co-authored-by: Marta Gómez Macías --- Lib/test/test_builtin.py | 10 ++++++++++ Misc/ACKS | 1 + .../2023-03-04-20-56-12.gh-issue-102356.07KvUd.rst | 2 ++ Python/bltinmodule.c | 2 ++ 4 files changed, 15 insertions(+) create mode 100644 Misc/NEWS.d/next/Core and Builtins/2023-03-04-20-56-12.gh-issue-102356.07KvUd.rst diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py index aabf0ab5a92a1b..f31ab72c02094c 100644 --- a/Lib/test/test_builtin.py +++ b/Lib/test/test_builtin.py @@ -799,6 +799,16 @@ def test_filter_pickle(self): f2 = filter(filter_char, "abcdeabcde") self.check_iter_pickle(f1, list(f2), proto) + def test_filter_dealloc(self): + # Tests recursive deallocation of nested filter objects using the + # thrashcan mechanism. See gh-102356 for more details. + max_iters = 1000000 + i = filter(bool, range(max_iters)) + for _ in range(max_iters): + i = filter(bool, i) + del i + gc.collect() + def test_getattr(self): self.assertTrue(getattr(sys, 'stdout') is sys.stdout) self.assertRaises(TypeError, getattr, sys, 1) diff --git a/Misc/ACKS b/Misc/ACKS index b4be8af3d99f6c..de1fb148e926cc 100644 --- a/Misc/ACKS +++ b/Misc/ACKS @@ -627,6 +627,7 @@ Tim Golden Yonatan Goldschmidt Mark Gollahon Mikhail Golubev +Marta Gómez Macías Guilherme Gonçalves Tiago Gonçalves Chris Gonnerman diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-03-04-20-56-12.gh-issue-102356.07KvUd.rst b/Misc/NEWS.d/next/Core and Builtins/2023-03-04-20-56-12.gh-issue-102356.07KvUd.rst new file mode 100644 index 00000000000000..c03fd5266bc301 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2023-03-04-20-56-12.gh-issue-102356.07KvUd.rst @@ -0,0 +1,2 @@ +Fix a bug that caused a crash when deallocating deeply nested filter +objects. Patch by Marta Gómez Macías. diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c index 659b78edc3de43..6ea20bfc5f7c94 100644 --- a/Python/bltinmodule.c +++ b/Python/bltinmodule.c @@ -567,9 +567,11 @@ static void filter_dealloc(filterobject *lz) { PyObject_GC_UnTrack(lz); + Py_TRASHCAN_BEGIN(lz, filter_dealloc) Py_XDECREF(lz->func); Py_XDECREF(lz->it); Py_TYPE(lz)->tp_free(lz); + Py_TRASHCAN_END } static int