Skip to content

[3.12] gh-111049: Fix crash during garbage collection of the BytesIO buffer object (GH-111221) #113096

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Dec 14, 2023
+27 −10
Merged

[3.12] gh-111049: Fix crash during garbage collection of the BytesIO buffer object (GH-111221) #113096

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
21 changes: 21 additions & 0 deletions Lib/test/test_memoryio.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,10 +6,12 @@
import unittest
from test import support

import gc
import io
import _pyio as pyio
import pickle
import sys
import weakref

class IntLike:
def __init__(self, num):
Expand Down Expand Up @@ -477,6 +479,25 @@ def test_getbuffer_empty(self):
buf2.release()
memio.write(b'x')

def test_getbuffer_gc_collect(self):
memio = self.ioclass(b"1234567890")
buf = memio.getbuffer()
memiowr = weakref.ref(memio)
bufwr = weakref.ref(buf)
# Create a reference loop.
a = [buf]
a.append(a)
# The Python implementation emits an unraisable exception.
with support.catch_unraisable_exception():
del memio
del buf
del a
# The C implementation emits an unraisable exception.
with support.catch_unraisable_exception():
gc.collect()
self.assertIsNone(memiowr())
self.assertIsNone(bufwr())

def test_read1(self):
buf = self.buftype("1234567890")
self.assertEqual(self.ioclass(buf).read1(), buf)
Expand Down
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Library/2023-10-23-18-42-26.gh-issue-111049.Ys7-o_.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Fix crash during garbage collection of the :class:`io.BytesIO` buffer
object.
14 changes: 4 additions & 10 deletions Modules/_io/bytesio.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -988,7 +988,9 @@ static int
bytesio_clear(bytesio *self)
{
Py_CLEAR(self->dict);
Py_CLEAR(self->buf);
if (self->exports == 0) {
Py_CLEAR(self->buf);
}
return 0;
}

Expand Down Expand Up @@ -1093,13 +1095,6 @@ bytesiobuf_releasebuffer(bytesiobuf *obj, Py_buffer *view)
b->exports--;
}

static int
bytesiobuf_clear(bytesiobuf *self)
{
Py_CLEAR(self->source);
return 0;
}

static int
bytesiobuf_traverse(bytesiobuf *self, visitproc visit, void *arg)
{
Expand All @@ -1114,15 +1109,14 @@ bytesiobuf_dealloc(bytesiobuf *self)
PyTypeObject *tp = Py_TYPE(self);
/* bpo-31095: UnTrack is needed before calling any callbacks */
PyObject_GC_UnTrack(self);
(void)bytesiobuf_clear(self);
Py_CLEAR(self->source);
tp->tp_free(self);
Py_DECREF(tp);
}

static PyType_Slot bytesiobuf_slots[] = {
{Py_tp_dealloc, bytesiobuf_dealloc},
{Py_tp_traverse, bytesiobuf_traverse},
{Py_tp_clear, bytesiobuf_clear},

// Buffer protocol
{Py_bf_getbuffer, bytesiobuf_getbuffer},
Expand Down