Description

assignee = None
closed_at = None
created_at = <Date 2021-05-19.02:08:10.843>
labels = ['3.8', '3.9', '3.10', '3.11', 'extension-modules', '3.7', 'type-crash']
title = 'curses module may call delwin() on original window before subwindows'
updated_at = <Date 2021-05-19.02:24:53.341>
user = 'https://github.com/michaelforney'

activity = <Date 2021-05-19.02:24:53.341>
actor = 'michaelforney'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Extension Modules']
creation = <Date 2021-05-19.02:08:10.843>
creator = 'michaelforney'
dependencies = []
files = []
hgrepos = []
issue_num = 44172
keywords = ['patch']
message_count = 1.0
messages = ['393916']
nosy_count = 1.0
nosy_names = ['michaelforney']
pr_nums = ['26226']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'crash'
url = 'https://bugs.python.org/issue44172'
versions = ['Python 3.6', 'Python 3.7', 'Python 3.8', 'Python 3.9', 'Python 3.10', 'Python 3.11']

Activity

1. michaelforney commented on May 19, 2021

   

   michaelforneymannequin

   on May 19, 2021

   MannequinAuthor

   More actions

   When subwin() is used to create a subwindow for an original window, it does not keep a reference to the original window object. This can result in the original window getting deleted with delwin() before the subwindow.

   According to the X/Open curses specification[0]:

   The application must delete subwindows before deleting the main window.

   This is also mentioned in the ncurses documentation[1]:

   Subwindows must be deleted before the main window can be deleted.

   When building the Python curses module against NetBSD's curses implementation, deleting the windows in the wrong order causes a double-free. This results in hanging or crashing when running test_curses.

   To fix this, window objects for subwindows should keep a reference to the original window object.

   [0] https://pubs.opengroup.org/onlinepubs/7908799/xcurses/delwin.html
   [1] https://invisible-island.net/ncurses/man/curs_window.3x.html
2. michaelforney

   added

   3.7 (EOL)end of lifeend of life

   3.8 (EOL)end of lifeend of life

   3.9 (EOL)end of lifeend of life

   3.10 (EOL)end of lifeend of life

   3.11only security fixesonly security fixes

   extension-modulesC modules in the Modules dirC modules in the Modules dir

   type-crashA hard crash of the interpreter, possibly with a core dumpA hard crash of the interpreter, possibly with a core dump

   on May 19, 2021
3. ezio-melotti

   transferred this issue fromon Apr 10, 2022
4. serhiy-storchaka

   added this to Curses issueson May 20, 2022
5. erlend-aasland

   moved this to Bugs in Curses issueson May 20, 2022
6. serhiy-storchaka

   closed this as completedon May 4, 2025
7. github-project-automation

   moved this from Bugs to Done in Curses issueson May 4, 2025
8. serhiy-storchaka

   added

   3.13only security fixesonly security fixes

   3.14bugs and security fixesbugs and security fixes

   and removed

   3.11only security fixesonly security fixes

   3.10 (EOL)end of lifeend of life

   3.9 (EOL)end of lifeend of life

   3.8 (EOL)end of lifeend of life

   3.7 (EOL)end of lifeend of life

   on May 4, 2025

Issue actions