Visitar URL original
fix: use-after-free in `get_data_from_buffer` by KowalskiThomas · Pull Request #677 · msgpack/msgpack-python · GitHub
Skip to content

fix: use-after-free in get_data_from_buffer #677

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
methane merged 3 commits into from
Jun 2, 2026
Merged

fix: use-after-free in get_data_from_buffer #677

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
9086469
test: add test
KowalskiThomas May 26, 2026
eae29a9
fix: use-after-free in get_data_from_buffer
KowalskiThomas May 26, 2026
7ee15a3
fix: address PR review comments
KowalskiThomas May 27, 2026
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
7 changes: 3 additions & 4 deletions msgpack/_unpacker.pyx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -129,10 +129,9 @@ cdef inline int get_data_from_buffer(object obj,
PyBuffer_Release(view)
# create a contiguous copy and get buffer
contiguous = PyMemoryView_GetContiguous(obj, PyBUF_READ, b'C')
PyObject_GetBuffer(contiguous, view, PyBUF_SIMPLE)
# view must hold the only reference to contiguous,
# so memory is freed when view is released
Py_DECREF(contiguous)
if PyObject_GetBuffer(contiguous, view, PyBUF_SIMPLE) == -1:
raise

Comment thread
KowalskiThomas marked this conversation as resolved.
buffer_len[0] = view.len
buf[0] = <char*> view.buf
return 1
Expand Down
2 changes: 1 addition & 1 deletion msgpack/fallback.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -328,7 +328,7 @@ def feed(self, next_bytes):
self._buf_checkpoint = 0

# Use extend here: INPLACE_ADD += doesn't reliably typecast memoryview in jython
self._buffer.extend(view)
self._buffer.extend(view if view.contiguous else view.tobytes())
view.release()
Comment thread
KowalskiThomas marked this conversation as resolved.

def _consume(self):
Expand Down
12 changes: 12 additions & 0 deletions test/test_memoryview.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -97,3 +97,15 @@ def test_multidim_memoryview():
data = view.cast(view.format, (3, 2))
packed = packb(data)
assert packed == b"\xc4\x06\x00\x00\x00\x00\x00\x00"


def test_unpack_noncontiguous_memoryview():
# Use a multi-byte value so the padded stride-2 view is non-contiguous.
packed = packb(2**32)
padded = bytearray()
for byte in packed:
padded.append(byte)
padded.append(0)
noncont = memoryview(bytes(padded))[::2]
assert not noncont.c_contiguous
assert unpackb(noncont) == 2**32
Loading