cpython/b$ ./python 
Python 3.11.0a3+ (heads/main-dirty:081a214008, Jan 11 2022, 02:48:22) [GCC 11.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ast
>>> ast.literal_eval('''F"""
... 
... 
... {6
... 0="""''')
Segmentation fault

this was discovered by oss-fuzz.

This may be a recent regression?  It didn't happen on my build from a few weeks ago.  worth testing on older versions.

I tested it on 3.10.1 and it didn't segfault on Windows 11 so seems like 3.11 regression.

Seems that the regression is caused by this commit:

6fa8b2ceee38187b0ae96aee12fe4f0a5c8a2ce7 is the first bad commit
commit 6fa8b2ceee38187b0ae96aee12fe4f0a5c8a2ce7
Author: Pablo Galindo Salgado <Pablogsal@gmail.com>
Date:   Sat Jan 8 00:23:40 2022 +0000

    bpo-46237: Fix the line number of tokenizer errors inside f-strings (GH-30463)

 Lib/test/test_exceptions.py                                  | 12 ++++++++++++
 .../2022-01-07-19-33-05.bpo-46237.9A6Hpq.rst                 |  2 ++
 Parser/pegen.c                                               |  8 ++++----
 Parser/string_parser.c                                       |  5 ++++-
 4 files changed, 22 insertions(+), 5 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2022-01-07-19-33-05.bpo-46237.9A6Hpq.rst

The reason is that the line numbers are now correctly identified, and that causes existing code to not work correctly :(

New changeset cedec19be81e6bd153678bfb28c8e217af8bda58 by Pablo Galindo Salgado in branch 'main':
bpo-46339: Fix crash in the parser when computing error text for multi-line f-strings (GH-30529)
https://github.com/python/cpython/commit/cedec19be81e6bd153678bfb28c8e217af8bda58

New changeset 8c2fd09f365e082cfceb29afdf38953cdd670946 by Pablo Galindo Salgado in branch 'main':
bpo-46339: Include clarification on assert in 'get_error_line_from_tokenizer_buffers' (#30545)
https://github.com/python/cpython/commit/8c2fd09f365e082cfceb29afdf38953cdd670946

New changeset 1fb1f5d8bd084c20f0a5fde547b563c08d103f09 by Miss Islington (bot) in branch '3.10':
[3.10] bpo-46339: Fix crash in the parser when computing error text for multi-line f-strings (GH-30529) (GH-30542)
https://github.com/python/cpython/commit/1fb1f5d8bd084c20f0a5fde547b563c08d103f09