commit d152126bb0293c321cae437bdf7437c393ee3619
author Luca Weiss <luca@z3ntu.xyz> Fri Dec 24 11:28:12 2021 +0100
committer David Gibson <david@gibson.dropbear.id.au> Sun Dec 26 15:44:32 2021 +1100
tree 3662ee5f6299d774c54e753c6a697f07b0622d62
parent 17739b7ef510917471409d71fb45d8eaf6a1e1fb

Fix Python crash on getprop deallocation

Fatal Python error: none_dealloc: deallocating None
Python runtime state: finalizing (tstate=0x000055c9bac70920)

Current thread 0x00007fbe34e47740 (most recent call first):
  <no Python frame>
Aborted (core dumped)

This is caused by a missing Py_INCREF on the returned Py_None, as
demonstrated e.g. in https://github.com/mythosil/swig-python-incref or
described at https://edcjones.tripod.com/refcount.html ("Remember to
INCREF Py_None!")

A PoC for triggering this crash is uploaded to
https://github.com/z3ntu/pylibfdt-crash .
With this patch applied to pylibfdt the crash does not happen.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Message-Id: <20211224102811.70695-1-luca@z3ntu.xyz>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>