Apparmor profile for Keybase.io to prevent insecure and multi-user unfriendly use of /keybase; will prevent start unless run_keybase is modified.

usr.bin.run_keybase

#include <tunables/global>

# At the time of writing requires changing /usr/bin/run_keybase
# Partial diff, which may or may not work for your needs.
#
# -  if fusermount -uz /keybase &> /dev/null ; then
# +  if fusermount -uz $HOME/Keybase &> /dev/null ; then
#
# -  kbfsfuse -debug -log-to-file /keybase &>> "$logdir/keybase.start.log" &
# +  kbfsfuse -debug -log-to-file $HOME/Keybase &>> "$logdir/keybase.start.log" &
#
# Copy this file to /etc/apparmor.d/usr.bin.run_keybase and run:
#
# $ sudo aa-enforce usr.bin.run_keybase
# Setting /etc/apparmor.d/usr.bin.run_keybase to enforce mode.

/usr/bin/run_keybase {

  #include <abstractions/base>


  network,
  capability,
  file,
  umount,

  deny @{PROC}/* w,   # deny write for all files directly in /proc (not in a subdir)
  # deny write to files not in /proc/<number>/** or /proc/sys/**
  deny @{PROC}/{[^1-9],[^1-9][^0-9],[^1-9s][^0-9y][^0-9s],[^1-9][^0-9][^0-9][^0-9]*}/** w,
  deny @{PROC}/sys/[^k]** w,  # deny /proc/sys except /proc/sys/k* (effectively /proc/sys/kernel)
  deny @{PROC}/sys/kernel/{?,??,[^s][^h][^m]**} w,  # deny everything except shm* in /proc/sys/kernel/
  deny @{PROC}/sysrq-trigger rwklx,
  deny @{PROC}/mem rwklx,
  deny @{PROC}/kmem rwklx,
  deny @{PROC}/kcore rwklx,

  deny mount,

  deny /sys/[^f]*/** wklx,
  deny /sys/f[^s]*/** wklx,
  deny /sys/fs/[^c]*/** wklx,
  deny /sys/fs/c[^g]*/** wklx,
  deny /sys/fs/cg[^r]*/** wklx,
  deny /sys/firmware/efi/efivars/** rwklx,
  deny /sys/kernel/security/** rwklx,

  # deny access to keybase directory created in root.
  deny /keybase/** rwklx,
}