https://github.com/python/cpython/commit/f7cc8623457ed0f79bddd32dd680303584684641 commit: f7cc8623457ed0f79bddd32dd680303584684641 branch: 3.13 author: Sam Gross <[email protected]> committer: colesbury <[email protected]> date: 2025-02-06T14:30:16-05:00 summary:
[3.13] gh-129732: Fix race on `shared->array` in qsbr code under free-threading (gh-129738) (gh-129747) The read of `shared->array` should happen under the lock to avoid a race. (cherry picked from commit b4ff8b22b3066b814c3758f87eaddfa923e657ed) Co-authored-by: Peter Hawkins <[email protected]> files: A Misc/NEWS.d/next/Core and Builtins/2025-02-06-17-57-33.gh-issue-129732.yl97oq.rst M Python/qsbr.c diff --git a/Misc/NEWS.d/next/Core and Builtins/2025-02-06-17-57-33.gh-issue-129732.yl97oq.rst b/Misc/NEWS.d/next/Core and Builtins/2025-02-06-17-57-33.gh-issue-129732.yl97oq.rst new file mode 100644 index 00000000000000..a4b104af61692a --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2025-02-06-17-57-33.gh-issue-129732.yl97oq.rst @@ -0,0 +1 @@ +Fixed a race in ``_Py_qsbr_reserve`` in the free threading build. diff --git a/Python/qsbr.c b/Python/qsbr.c index a40219acfe2c29..0df1285cc8e063 100644 --- a/Python/qsbr.c +++ b/Python/qsbr.c @@ -205,15 +205,15 @@ _Py_qsbr_reserve(PyInterpreterState *interp) } _PyEval_StartTheWorld(interp); } - PyMutex_Unlock(&shared->mutex); - - if (qsbr == NULL) { - return -1; - } // Return an index rather than the pointer because the array may be // resized and the pointer invalidated. - return (struct _qsbr_pad *)qsbr - shared->array; + Py_ssize_t index = -1; + if (qsbr != NULL) { + index = (struct _qsbr_pad *)qsbr - shared->array; + } + PyMutex_Unlock(&shared->mutex); + return index; } void _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: [email protected]
