Re: Emergency Unmount...

[Perego Paolo <sponge@tiscalinet.it>]

On Wed, Apr 04, 2001 at 03:05:05PM +0200, Erik Mouw wrote:
> > I can't figure out what do you means talking about obscurity :)
> 
> Obscure (and/or undocumented) ways to protect a system are not going to
In documentation I will exlain that you need to enter the password twice in
the char dev. The point is that just the legal root, knows which is the
password to use. The password is however stored hashed using MD5.

I agree that, a skilled cracker could bypass my work playing along /dev/kmem.
Who needs writing ( except kernel of course ) in /dev/kmem?

> I think you can do it very simple by using the exported function
> handle_sysrq():
Maybe I'm wrong, but I'm newbie in kernel hacking.
I've included linux/sysrq.h. I've compiled the module correctly but, during
insmod, sysrq_enabled and handle_sysrq are signaled as unresolved symbol...

zion:~/tesi# insmod angel.o password=paolo
angel.o: unresolved symbol sysrq_enabled
angel.o: unresolved symbol handle_sysrq
zion:~/tesi#

They appear in System.map:
c01744f0 T handle_sysrq
c022c878 D sysrq_enabled

But don't in /proc/ksyms:
zion:~/tesi# grep sysrq /proc/ksyms
c028c624 sysrq_power_off_R0c257849
zion:~/tesi#

-- 
$>cd /pub
$>more beer

(0>
//\  Perego Paolo <sponge@tiscalinet.it> Tutor at D.S.I. University of Milan
V_/_ 'The future will not remember, the past doesn't forget.'
I'm Linux zion 2.4.3 #4 Wed Apr 4 16:14:35 CEST 2001 i586

PGP signature