BUG: Segfault When __array_ufunc__ Called With Garbage #24023
Description
Describe the issue:
Thanks for the great work!
To try to detect bugs in a system which caches off numpy arrays, I have a test which calls every method returned by dir on a numpy array with many permutations of random data of various types. In the last few days CI has started segfaulting and I have been able to reproduce locally after upgrading to numpy=1.25.0 when calling array.__array_ufunc__(2.3, 1).
Admittedly calling every function with every permutation of random garbage data isn't real use case and happy to close this and just skip the __array_ufunc__ in this test (after which my test went back to passing). But it just started happening, reproduced pretty well and none of the other methods segfault under any inputs I could put together so I thought it might be interesting.
Reproduce the code example:
mikedh@luna:tests$ python -X faulthandler
Python 3.11.0rc1 (main, Aug 12 2022, 10:02:14) [GCC 11.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy as np
>>> a = np.empty(1)
>>> a.__array_ufunc__(2.3, 1)
Fatal Python error: Segmentation fault
Current thread 0x00007efca4ce1000 (most recent call first):
File "<stdin>", line 1 in <module>
Extension modules: 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 (total: 13)
Segmentation fault (core dumped)Error message:
Fatal Python error: Segmentation fault
Current thread 0x00007efca4ce1000 (most recent call first):
File "<stdin>", line 1 in <module>
Extension modules: 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 (total: 13)
Segmentation fault (core dumped)Runtime information:
I have seen this in Github actions, Docker, and my Parallels desktop Ubuntu 22.04 virtual.
My desktop VM:
In [7]: import sys, numpy; print(numpy.__version__); print(sys.version)
1.25.0
3.11.0rc1 (main, Aug 12 2022, 10:02:14) [GCC 11.2.0]
In [8]: print(numpy.show_runtime())
WARNING: `threadpoolctl` not found in system! Install it by `pip install threadpoolctl`. Once installed, try `np.show_runtime` again for more detailed build information
[{'numpy_version': '1.25.0',
'python': '3.11.0rc1 (main, Aug 12 2022, 10:02:14) [GCC 11.2.0]',
'uname': uname_result(system='Linux', node='luna', release='5.19.0-45-generic', version='#46~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Jun 7 15:06:04 UTC 20', machine='x86_64')},
{'simd_extensions': {'baseline': ['SSE', 'SSE2', 'SSE3'],
'found': ['SSSE3',
'SSE41',
'POPCNT',
'SSE42',
'AVX',
'F16C',
'FMA3',
'AVX2'],
'not_found': ['AVX512F',
'AVX512CD',
'AVX512_KNL',
'AVX512_KNM',
'AVX512_SKX',
'AVX512_CLX',
'AVX512_CNL',
'AVX512_ICL']}}]
None
Context for the issue:
It doesn't effect my work, I already skipped this in tests, I thought the team might find inducable hard segfaults interesting.
Here is the "call every method with garbage" test that induced the segfault