/usr/share/doc/libdmalloc-dev/examples/contrib/ is in libdmalloc-dev 5.5.2-8.
This file is owned by root:root, with mode 0o755.
..
/usr/share/doc/libdmalloc-dev/examples/contrib/README
/usr/share/doc/libdmalloc-dev/examples/contrib/Xmalloc.c
/usr/share/doc/libdmalloc-dev/examples/contrib/aix_5l_notes
/usr/share/doc/libdmalloc-dev/examples/contrib/aix_notes
/usr/share/doc/libdmalloc-dev/examples/contrib/atexit.c
/usr/share/doc/libdmalloc-dev/examples/contrib/dec_notes
/usr/share/doc/libdmalloc-dev/examples/contrib/dgux_notes
/usr/share/doc/libdmalloc-dev/examples/contrib/dmalloc.gdb
/usr/share/doc/libdmalloc-dev/examples/contrib/dmalloc_summarize.pl
/usr/share/doc/libdmalloc-dev/examples/contrib/next_notes
/usr/share/doc/libdmalloc-dev/examples/contrib/ra_info.pl
/usr/share/doc/libdmalloc-dev/examples/contrib/stratus_ftx_notes
/usr/share/doc/libdmalloc-dev/examples/contrib/tsecs
/usr/share/doc/libdmalloc-dev/examples/contrib/z_os_notes