[Beowulf] A careful exploit?

John Hearns hearnsj at googlemail.com
Thu Jun 13 22:24:50 PDT 2019


Regarding serial ports - if you have IPMI then of course you have a virtual
serial port.

I learned something new about serial ports and IPMI Serial Over LAN
recently..
First of all you have to use the kernel config option     console=ttyy0
console=ttyS1,115200
This is well known.

In the bad old days you had to edit the /etc/inittab and arrange a spawn of
a getty process on /dev/ttyS1
One gotcha - /dev/ttyS1 usualy corresponds to serial port 0 in the BIOS. (I
may have that work=g but there is a mismatch)

These days there is a service which is managed under system and will
automatically detect and configure the serial terminal.
You still need the kernel console= option of course.
system enable serial-getty

The youth of today etc. Not having to solder up RS232 plugs and find the
baud rate by listening to a modem...

Blog here on serial consoles in system
http://0pointer.de/blog/projects/serial-console.html
I am genuinely impressed at how good this is - it worked first time on
Debian system













On Fri, 14 Jun 2019 at 02:39, Robert G. Brown <rgb at phy.duke.edu> wrote:

> On Thu, 13 Jun 2019, Jonathan Engwall wrote:
>
> > I did not see Robert Brown's reply until J?rg Sa?manshausen quote the
> entire
> > thing.It's all gone now. I got rid of the netgear router too. My policies
> > are Drop and my rsa keys are specific. It works perfectly when nobody
> slips
> > in.
> > "Hang a console on it" this sound fscinationg. Consoles give me trouble.
> > I will read up on it.
>
> In the old days -- and I'm a relic of the old days;-) -- one did
> EVERYTHING from a console.  Even now I do most of my systems work from a
> tty interface, basically an xterm.
>
> It's a lot harder to manage now, since serial ports are dead... if the
> particular problem you're trying to debug is the network...
>
>     rgb
>
> > Thank you.
> > Jonathan Engwall.
> >
> >
>
> Robert G. Brown                        http://www.phy.duke.edu/~rgb/
> Duke University Dept. of Physics, Box 90305
> Durham, N.C. 27708-0305
> Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu
>
>
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