Confined sysadm users cannot execute administrative commands using `sudo`, "sesh: unable to execute <command>: Permission denied" is printed

Issue

• When a user is confined to staff_u SELinux user and switches role to sysadm_r while trying to execute an administrative command under sudo, e.g. /sbin/postsuper, the following error is returned

  $ sudo -r sysadm_r /sbin/postsuper
  sesh: unable to execute /sbin/postsuper: Permission denied
  

• Same issue happens for staff_u SELinux users which automatically switch role to sysadm_r when executing sudo