Web lists-archives.com

Re: [DNG] Linux system can be brought down by sending SIGILL to Systemd




On Fri, 24 May 2019 23:43:49 +0200
arne <sp113438@xxxxxxxxxx> wrote:

> On Fri, 24 May 2019 14:01:35 -0700
> Fred <fred@xxxxxxxxxxxx> wrote:
> 
> > Hello,
> > I subscribe to the Devuan Linux mailing list.  This posting just
> > arrived and it appears quite important to Debian.
> > 
> > -------- Forwarded Message --------
> > Subject: 	[DNG] Linux system can be brought down by sending
> > SIGILL to Systemd
> > Date: 	Fri, 24 May 2019 22:04:34 +0200
> > From: 	Martin Steigerwald <martin@xxxxxxxxxxxx>
> > To: 	DNG <dng@xxxxxxxxxxxxxx>
> > 
> > 
> > 
> > Hi!
> > 
> > Today in a Linux training a participant attempted to bring down
> > Debian workstation with Systemd by sending signals to PID 1 as I
> > invited them to try to bring down PID 1 while thinking for myself
> > that this would not be possible from my past experiences about
> > trying to bring down PID 1 – init – myself.  
> 
> # while true; do kill -ILL 1 ; echo -n "." ;  sleep 0.5 ; done
> ...........................^C
> 
> no problem here
> kernel 5.1.4 stretch amd64 with systemd
> 

Perhaps that test was a little too short so I let it run a little
longer:

# while true; do kill -ILL 1 ; echo -n "." ;  sleep 0.5 ; done
..................................................................................................................................................................................................................................................................................................................................................................................................................................................^C

again no problem here.

I had no fear to run the script as I use systemd, so I know how to
use the SysReq keys very well ;)