/usr/lib/gcc/arm-linux-gnueabihf/4.6/sf/libgfortran.so is in gfortran-4.6-multilib-arm-linux-gnueabihf 4.6.3-1ubuntu5cross1.63.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/gcc/arm-linux-gnueabihf/4.6/sf/../../../../../arm-linux-gnueabihf/lib/arm-linux-gnueabi/libgfortran.so.3