On יום רביעי, 6 בדצמבר 2017 22:52:17 IST Urs Thuermann wrote: > Yesterday, my 10 years old son logged into my laptop running Debian > jessie using his account, and curiously asked if he is allowed to try > the /sbin/reboot command. Knowing I have a Linux system as opposed to > some crappy Win machine, I replied "sure, go ahead and try". Seconds > later I was completely shocked when the machine actually rebooted... > > Of course, my son doesn't have any special privileges, no entry in > /etc/sudoers, etc. But then I see > > $ ls -l /sbin/reboot > lrwxrwxrwx 1 root root 14 Apr 8 2017 /sbin/reboot -> /bin/systemctl > $ ls -l /bin/systemctl > -rwxr-xr-x 1 root root 538904 Apr 8 2017 /bin/systemctl > $ dpkg -S /bin/systemctl > systemd: /bin/systemctl > > The /bin/systemctl binary is not suid root, so I assume[1] it > communicates to systemd which then reboots the machine without > checking what user the request comes from. > > I wonder how can such a severe bug make it into a Debian stable > distribution? And is this just an insane default setting on Debian's > side or is it yet another instance of brain-dead systemd behavior? > > Searching the man pages I couldn't find a way to fix this. How can > that be stopped? > > [1] Of course, this is not docuemented in systemctl(1) as usual with > systemd. Also, according to the man page, systemctl must be > called with a "COMMAND" argument which /sbin/reboot doesn't do. > Obviously, systemctl looks at the name it was called and somehow > uses that as command. The admin shall guess about this. > > > urs
I find I need to use "sudo" to shutdown or reboot. That is using those (pseudo?) commands. Maybe their scripts check before going to sysemctl