From 57100c86baa8451a568348646834380cd425b858 Mon Sep 17 00:00:00 2001 From: "Miss Islington (bot)" <31488909+miss-islington@users.noreply.github.com> Date: Fri, 26 Nov 2021 16:42:00 -0800 Subject: [3.10] bpo-41735: Fix thread lock in zlib.Decompress.flush() may go wrong (GH-29587) (GH-29811) * Fix thread lock in zlib.Decompress.flush() may go wrong Getting `.unconsumed_tail` before acquiring the thread lock may mix up decompress state. (cherry picked from commit 7edb6270a78c695e4c2ae2432797dc18105374fc) Co-authored-by: Ma Lin Automerge-Triggered-By: GH:gpshead --- Misc/NEWS.d/next/Library/2021-11-16-18-13-49.bpo-41735.D72UY1.rst | 1 + Modules/zlibmodule.c | 5 +++-- 2 files changed, 4 insertions(+), 2 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2021-11-16-18-13-49.bpo-41735.D72UY1.rst diff --git a/Misc/NEWS.d/next/Library/2021-11-16-18-13-49.bpo-41735.D72UY1.rst b/Misc/NEWS.d/next/Library/2021-11-16-18-13-49.bpo-41735.D72UY1.rst new file mode 100644 index 0000000..101da0e --- /dev/null +++ b/Misc/NEWS.d/next/Library/2021-11-16-18-13-49.bpo-41735.D72UY1.rst @@ -0,0 +1 @@ +Fix thread lock in ``zlib.Decompress.flush()`` method before ``PyObject_GetBuffer``. diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c index 68de701..a6940f2 100644 --- a/Modules/zlibmodule.c +++ b/Modules/zlibmodule.c @@ -1266,12 +1266,13 @@ zlib_Decompress_flush_impl(compobject *self, PyTypeObject *cls, return NULL; } + ENTER_ZLIB(self); + if (PyObject_GetBuffer(self->unconsumed_tail, &data, PyBUF_SIMPLE) == -1) { + LEAVE_ZLIB(self); return NULL; } - ENTER_ZLIB(self); - self->zst.next_in = data.buf; ibuflen = data.len; -- cgit v0.12