/usr/src/linux-source-4.4.0/debian.master/config/ is in linux-source-4.4.0 4.4.0-137.163.
This file is owned by root:root, with mode 0o755.
..
/usr/src/linux-source-4.4.0/debian.master/config/amd64/
/usr/src/linux-source-4.4.0/debian.master/config/amd64/config.common.amd64
/usr/src/linux-source-4.4.0/debian.master/config/amd64/config.flavour.generic
/usr/src/linux-source-4.4.0/debian.master/config/amd64/config.flavour.lowlatency
/usr/src/linux-source-4.4.0/debian.master/config/annotations
/usr/src/linux-source-4.4.0/debian.master/config/arm64/
/usr/src/linux-source-4.4.0/debian.master/config/arm64/config.common.arm64
/usr/src/linux-source-4.4.0/debian.master/config/arm64/config.flavour.generic
/usr/src/linux-source-4.4.0/debian.master/config/armhf/
/usr/src/linux-source-4.4.0/debian.master/config/armhf/config.common.armhf
/usr/src/linux-source-4.4.0/debian.master/config/armhf/config.flavour.generic
/usr/src/linux-source-4.4.0/debian.master/config/armhf/config.flavour.generic-lpae
/usr/src/linux-source-4.4.0/debian.master/config/config.common.ports
/usr/src/linux-source-4.4.0/debian.master/config/config.common.ubuntu
/usr/src/linux-source-4.4.0/debian.master/config/i386/
/usr/src/linux-source-4.4.0/debian.master/config/i386/config.common.i386
/usr/src/linux-source-4.4.0/debian.master/config/i386/config.flavour.generic
/usr/src/linux-source-4.4.0/debian.master/config/i386/config.flavour.lowlatency
/usr/src/linux-source-4.4.0/debian.master/config/powerpc/
/usr/src/linux-source-4.4.0/debian.master/config/powerpc/config.common.powerpc
/usr/src/linux-source-4.4.0/debian.master/config/powerpc/config.flavour.powerpc-e500mc
/usr/src/linux-source-4.4.0/debian.master/config/powerpc/config.flavour.powerpc-smp
/usr/src/linux-source-4.4.0/debian.master/config/powerpc/config.flavour.powerpc64-emb
/usr/src/linux-source-4.4.0/debian.master/config/powerpc/config.flavour.powerpc64-smp
/usr/src/linux-source-4.4.0/debian.master/config/ppc64el/
/usr/src/linux-source-4.4.0/debian.master/config/ppc64el/config.common.ppc64el
/usr/src/linux-source-4.4.0/debian.master/config/ppc64el/config.flavour.generic
/usr/src/linux-source-4.4.0/debian.master/config/s390x/
/usr/src/linux-source-4.4.0/debian.master/config/s390x/config.common.s390x
/usr/src/linux-source-4.4.0/debian.master/config/s390x/config.flavour.generic
/usr/src/linux-source-4.4.0/debian.master/config/x32/
/usr/src/linux-source-4.4.0/debian.master/config/x32/config.common.x32
/usr/src/linux-source-4.4.0/debian.master/config/x32/config.flavour.generic