[lxc-users] Block devices not permitted on file system

[Christian Brauner]

Hello,

booting unprivileged ubuntu trusty and vivid container I get the
following messaged when shutting them down:

    umount: /dev/zero: block devices are not permitted on filesystem
    umount: /dev/urandom: block devices are not permitted on filesystem
    umount: /dev/tty: block devices are not permitted on filesystem
    umount: /dev/random: block devices are not permitted on filesystem
    umount: /dev/null: block devices are not permitted on filesystem
    umount: /dev/full: block devices are not permitted on filesystem
    umount: /dev/console: block devices are not permitted on filesystem

that goes for basically all device bind-mounts:

    umount: /dev/fb0: block devices are not permitted on filesystem
    umount: /dev/video0: block devices are not permitted on filesystem
    umount: /dev/dri: block devices are not permitted on filesystem
    umount: /dev/snd: block devices are not permitted on filesystem
    umount: /dev/zero: block devices are not permitted on filesystem
    umount: /dev/urandom: block devices are not permitted on filesystem
    umount: /dev/tty: block devices are not permitted on filesystem
    umount: /dev/random: block devices are not permitted on filesystem
    umount: /dev/null: block devices are not permitted on filesystem
    umount: /dev/full: block devices are not permitted on filesystem
    umount: /dev/console: block devices are not permitted on filesystem

Can someone explain this?

Best,
Christian