Restarting init without restarting the system

Question

In this question, the accepted answers states that

For example, /sbin/init uses glibc [the vulnerable lib], and restarting that without a reboot is non-trivial.

Now, non-trivial is engineer'ish for impossible, but I'm still curious:

Is it possible to restart init without restarting the whole system?

In this case, “non-trivial” is engineerish for “I don't know how to do it”. — Gilles 'SO- stop being evil', Jan 29 '15 at 21:55

score 18 · Accepted Answer · answered Jan 29 '15 at 11:45

18

telinit u

will restart init without affecting the rest of the system.

answered Jan 29 '15 at 11:45

Stephen Kitt

Not a that crazy work arround as I expected/hoped for, but correct. Thank you :) – Sebb Jan 29 '15 at 11:58
5

I can't imagine that the sysv init does any calls to gethostbyname() etc., and certainly not with data that comes from outside of the system so I don't consider restarting init a priority in the context of the ghost bug. – wurtel Jan 29 '15 at 13:46
5

This works for sysvinit and systemd (equivalent to systemd daemon-reexec). – Braiam Jan 29 '15 at 15:30
2

This doesn't work with all init implementations on all Unix variants (IIRC on AIX you're out of work), but as far as I know it does work with all init implementations that might be linked with glibc. – Gilles 'SO- stop being evil' Jan 29 '15 at 21:51

score 3 · Answer 2 · edited Mar 03 '16 at 15:02

3

A simple init u does the trick!

Afterwards, zypper ps doesn't report deleted files of the init process any more.

edited Mar 03 '16 at 15:02

don_crissti

answered Mar 03 '16 at 14:21

Thomas

2 Answers2