From b44e83f14fbe440f9af96acd6d07ca7d64f8cd3f Mon Sep 17 00:00:00 2001 From: Jelle Zijlstra Date: Mon, 19 Oct 2026 19:29:25 -0700 Subject: [PATCH] gh-159739: Check character formatting allocation failure (GH-159746) Propagate the error from PyUnicode_FromOrdinal() before using the result. (cherry picked from commit 5b0ab21364813b4f78e04a1a6b2805f6bdcc5d46) Co-authored-by: Jelle Zijlstra --- .../2026-10-19-19-33-35.gh-issue-159739.173d49.rst | 2 ++ Objects/unicode_formatter.c | 3 +++ 2 files changed, 5 insertions(+) create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-19-33-35.gh-issue-159739.173d49.rst diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-19-33-35.gh-issue-159739.173d49.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-19-33-35.gh-issue-159739.173d49.rst new file mode 100644 index 000000000000000..a552d06ff7bb898 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-19-33-35.gh-issue-159739.173d49.rst @@ -0,0 +1,2 @@ +Avoid a crash if formatting an integer with the ``c`` presentation type runs +out of memory. diff --git a/Objects/unicode_formatter.c b/Objects/unicode_formatter.c index b8604d1355940a5..252c317b0f6909f 100644 --- a/Objects/unicode_formatter.c +++ b/Objects/unicode_formatter.c @@ -1256,6 +1256,9 @@ format_long_internal(PyObject *value, const InternalFormatSpec *format, goto done; } tmp = PyUnicode_FromOrdinal(x); + if (tmp == NULL) { + goto done; + } inumeric_chars = 0; n_digits = 1; maxchar = Py_MAX(maxchar, (Py_UCS4)x);