/usr/lib/python2.7/dist-packages/sigmask.so is in python-sigmask 2.4.1-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/qm/sigmask.so
/usr/lib/python2.7/dist-packages/qm/sigmask.so