Crash report

What happened?

The following code will cause an abort due tobyte_size not matching the size ofctypes.c_byte, failing an assertion thatbyte_size == info->size.

importctypesctypes.CField(name="a",type=ctypes.c_byte,byte_size=2,byte_offset=2,index=1,_internal_use=True)

Abort message:

python: ./Modules/_ctypes/cfield.c:102: PyCField_new_impl: Assertion `byte_size == info->size' failed.Aborted (core dumped)

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Output from running 'python -VV' on the command line:

Python 3.14.0a6+ (heads/main:be2d2181e62, Mar 31 2025, 07:30:17) [GCC 11.4.0]

Linked PRs

• gh-132470: Prevent crash in ctypes.CField whenbyte_size is incorrect #132475