/usr/share/pyshared/sphinx/ext/ is in python-sphinx 1.1.3+dfsg-2ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/pyshared/sphinx/ext/__init__.py
/usr/share/pyshared/sphinx/ext/autodoc.py
/usr/share/pyshared/sphinx/ext/autosummary/
/usr/share/pyshared/sphinx/ext/autosummary/__init__.py
/usr/share/pyshared/sphinx/ext/autosummary/generate.py
/usr/share/pyshared/sphinx/ext/coverage.py
/usr/share/pyshared/sphinx/ext/doctest.py
/usr/share/pyshared/sphinx/ext/extlinks.py
/usr/share/pyshared/sphinx/ext/graphviz.py
/usr/share/pyshared/sphinx/ext/ifconfig.py
/usr/share/pyshared/sphinx/ext/inheritance_diagram.py
/usr/share/pyshared/sphinx/ext/intersphinx.py
/usr/share/pyshared/sphinx/ext/jsmath.py
/usr/share/pyshared/sphinx/ext/mathbase.py
/usr/share/pyshared/sphinx/ext/mathjax.py
/usr/share/pyshared/sphinx/ext/oldcmarkup.py
/usr/share/pyshared/sphinx/ext/pngmath.py
/usr/share/pyshared/sphinx/ext/refcounting.py
/usr/share/pyshared/sphinx/ext/todo.py
/usr/share/pyshared/sphinx/ext/viewcode.py