Segmentation fault when converting an uninitialized surface with argument (3519)

[GalacticEmperor1]

Issue №3519 opened by Matiiss at 2022-10-26 13:26:27

Environment:

• Windows 10
• Python 3.10.6
• pygame 2.1.3.dev9 (could reproduce on 2.1.2 and 2.1.0 too)

MRE:

import pygame


pygame.display.set_mode((1, 1))

pygame.Surface.__new__(pygame.Surface).convert(24)

It does not really matter what the argument is as long as it's a python object (except for pygame.Surface), it raises this Segmentation fault:

pygame 2.1.3.dev9 (SDL 2.0.22, Python 3.10.6)
Hello from the pygame community. https://www.pygame.org/contribute.html
Fatal Python error: pygame_parachute: (pygame parachute) Segmentation Fault
Python runtime state: initialized

Current thread 0x000017c8 (most recent call first):
  File "C:\Users\Matiiss\PycharmProjects\Something\for_so.py", line 6 in <module>

Extension modules: pygame.base, pygame.constants, pygame.rect, pygame.rwobject, pygame.surflock, pygame.bufferproxy, pygame.math, pygame.surface, pygame.display, pygame.draw, pygame.event, pygame.imageext, pygame.image, pygame.joystick, pygame.key, pygame.mouse, pygame.time, pygame.mask, pygame.pixelcopy, pygame.transform, pygame.font, pygame.mixer_music, pygame.mixer, pygame.scrap, numpy.core._multiarray_umath, numpy.core._multiarray_tests, numpy.linalg._umath_linalg, numpy.fft._pocketfft_internal, numpy.random._common, numpy.random.bit_generator, numpy.random._bounded_integers, numpy.random._mt19937, numpy.random.mtrand, numpy.random._philox, numpy.random._pcg64, numpy.random._sfc64, numpy.random._generator, win32api, _win32sysloader, pygame._freetype (total: 40)

The issue stems from this line https://github.com/pygame/pygame/blob/main/src_c/surface.c# L1449 where all it does is simply check if there is any argument given and then it checks if it is a surface and if it fails that, it tries to memcpy format which doesn't exist if the surface hasn't been initialized (at least how I understand it).

If it's nothing too complicated I'm down to fix this, I'd just like to know what the suggested way to do so would be.

Also I suppose the expected output should be the same as when doing it without an argument (or when it's a surface):

import pygame


pygame.display.set_mode((1, 1))

pygame.Surface.__new__(pygame.Surface).convert()

pygame 2.1.3.dev9 (SDL 2.0.22, Python 3.10.6)
Hello from the pygame community. https://www.pygame.org/contribute.html
Traceback (most recent call last):
  File "C:\Users\Matiiss\PycharmProjects\Something\for_so.py", line 6, in <module>
    pygame.Surface.__new__(pygame.Surface).convert()
pygame.error: Parameter 'surface' is invalid

---

Comments

# # Matiiss commented at 2022-11-12 23:54:38

This should also be fixed in pygame.transform and pygame.draw modules. Perhaps, other places where you pass a surface argument. As well as check if destination surfaces have been initialized.

---

# # Matiiss commented at 2022-11-13 08:05:47

Additionally, I suppose some test could be implemented that would iterate over all modules and pass an uninitialized (dead) surface to each method in that module (try/except those cases where such argument is not expected), special cases should be somehow added for when there is an optional destination surface (could just try simply passing as a keyword argument and hope that each method supporting a destination surface supports those), this would then allow to avoid such issues in the future when implementing new methods that deal with surfaces.

---

# # Starbuck5 commented at 2023-01-01 07:33:46

We've figured out that the display surface is set to NULL when the display is quit. So there is a time when a ->surf is supposed to be NULL, and that explains why some things have a check for this that emits "display surface quit"

[yunline]

Fixed by #1940