/usr/arm-linux-gnueabihf/lib/sf is in libc6-dev-armel-cross 2.27-3ubuntu1cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/arm-linux-gnueabihf/lib/../../arm-linux-gnueabi/lib
/usr/arm-linux-gnueabihf/lib/../../arm-linux-gnueabi/lib