Play a joke on X....

Play a joke on X....

Post by James Yo » Wed, 26 Jun 1996 04:00:00



Hi, all there:

        I have Linux 3.0.0 and X11R6 on my machine.
Some day, while I was doing something, an user
login on my host and used 'startx'.... then I entered

        And another time, an user used 'repeat 1000 joke'
to start MANY xclocks (of course, there are xclock & command
in the file joke), so I got into trouble....

        How to prevent users from playing such jokes on me??

Thanx..

--
-------------------------------------------------
James Yong (Chuo-han Yang)


-------------------------------------------------

 
 
 

Play a joke on X....

Post by Geoff Sho » Wed, 26 Jun 1996 04:00:00


:       How to prevent users from playing such jokes on me??

Change their passwords to '*'

        Geoff

ps If you are using X, then `xhost -` will prevent others from writing to
your screen.  You could make it so that only root can run X, maybe using
xdm to display a login screen.
--
---------------------------------------------------------------------------


can't identify with that kind of work ethic.  http://www.york.ac.uk/~grs100

 
 
 

Play a joke on X....

Post by Filipe Custodi » Wed, 26 Jun 1996 04:00:00



> =
> Hi, all there:
> =
>         I have Linux 3.0.0 and X11R6 on my machine.
> Some day, while I was doing something, an user
> login on my host and used 'startx'.... then I entered

> =
>         And another time, an user used 'repeat 1000 joke'
> to start MANY xclocks (of course, there are xclock & command
> in the file joke), so I got into trouble....
> =
>         How to prevent users from playing such jokes on me??
> =
> Thanx..

While using XWindows, type 'xhost -'.

-- =

---------------------------------------

---------------------------------------

 
 
 

Play a joke on X....

Post by Joni K?m?r?ine » Wed, 26 Jun 1996 04:00:00



> Hi, all there:

>         I have Linux 3.0.0 and X11R6 on my machine.
> Some day, while I was doing something, an user
> login on my host and used 'startx'.... then I entered

>         And another time, an user used 'repeat 1000 joke'
> to start MANY xclocks (of course, there are xclock & command
> in the file joke), so I got into trouble....

>         How to prevent users from playing such jokes on me??

add star(*) in passwd -file for them  ;-)
 
 
 

Play a joke on X....

Post by James Yo » Thu, 27 Jun 1996 04:00:00


: Change their passwords to '*'

Good solution.. but not practicable..

: ps If you are using X, then `xhost -` will prevent others from writing to

  First, I have tried to use it.. but it is no use for an user who had been
logined on my host. He can run 'host +' by himself. So still no answer??

  On the other hand, this cammand can't prevent users from using 'startx'.
Are there any options for X server that can set the login tty?? I think
this is the best way to solve such a problem..

--
-------------------------------------------------
James Yong (Chuo-han Yang)


-------------------------------------------------

 
 
 

Play a joke on X....

Post by Jo » Thu, 27 Jun 1996 04:00:00





>: Change their passwords to '*'

>Good solution.. but not practicable..

>: ps If you are using X, then `xhost -` will prevent others from writing to

>  First, I have tried to use it.. but it is no use for an user who had been
>logined on my host. He can run 'host +' by himself. So still no answer??

>  On the other hand, this cammand can't prevent users from using 'startx'.
>Are there any options for X server that can set the login tty?? I think
>this is the best way to solve such a problem..

>--
>-------------------------------------------------
>James Yong (Chuo-han Yang)


>-------------------------------------------------

Why not just make those files only accessible to root or whatever
group you feel secure with?

Life is grand, don't mess it up..
Existence is meaningless, buck up!
----------


Web Page:  http://blackhole.dorms.tamu.edu
Ftp Site:  ftp://blackhole.dorms.tamu.edu

 
 
 

Play a joke on X....

Post by James Yo » Thu, 27 Jun 1996 04:00:00


: Why not just make those files only accessible to root or whatever
: group you feel secure with?

: Life is grand, don't mess it up..
: Existence is meaningless, buck up!

Yeah.... I think you are right....
But I just expect X window for being better....

Hummm.. Maybe I've to get myself better.

--
-------------------------------------------------
James Yong (Chuo-han Yang)


-------------------------------------------------

 
 
 

Play a joke on X....

Post by Marc A. Sel » Thu, 27 Jun 1996 04:00:00



>    I have Linux 3.0.0 and X11R6 on my machine.
>Some day, while I was doing something, an user
>login on my host and used 'startx'.... then I entered


Fix your scripts permissions.  Nobody who is not working on the console
should be able to bring up X on the localhost.  My preferred alternative
is to get rid of startx altogether and manage X (both for the console
and for peers connected via some Net) via xdm.  Be sure to use a current
release of XFree (if it is XFree you are using), for older versions of
xdm had security problems.

Quote:>    And another time, an user used 'repeat 1000 joke'
>to start MANY xclocks (of course, there are xclock & command
>in the file joke), so I got into trouble....

No way to prevent this under Linux, as far as I know.  (Let me know if
you should find one.)  Linux was not really made for users competing for
resources, and that is what is going on here.  (The man page for
ulimit(2) is unimplemented(2), as of 1.2.13.  On systems that do support
it, however, ulimit can be used to limit such things as maximum size of
files created, memory and cpu time used and number of processes started.
These limits can be set for a process and all its children.)

Quote:>    How to prevent users from playing such jokes on me??

There are methods that usually work, but they do not have much to do
with software configuration.  Anybody who plays these "jokes" is kicked
out of the system.  If your system is used in a professional environment
(as opposed to some hobby server that probably does not take any real
damage from this), make them pay for all damages incurred (loss of cpu
time, loss of availability, administrator's time).  This tends to
discourage "jokers", although it is no "clean" solution, of course.

cu
   Marc

--

Please cc public responses to email.
Get my pgp key: http://www.fak14.uni-muenchen.de/~mselig/mykey.asc

 
 
 

Play a joke on X....

Post by Anthony J. Stuck » Sat, 29 Jun 1996 04:00:00



>: ps If you are using X, then `xhost -` will prevent others from writing to
>  First, I have tried to use it.. but it is no use for an user who had been
>logined on my host. He can run 'host +' by himself. So still no answer??

        If xauth is active, you cannot run xhost + effectively on someone
else's display.  The ability to break xauth is still debatable.  Manypeople
leave their key files around in places they shouldn't.

Quote:>  On the other hand, this cammand can't prevent users from using 'startx'.
>Are there any options for X server that can set the login tty?? I think
>this is the best way to solve such a problem..

        It's not hard to wrap startx in a script or program that checks (in the
same manner as /etc/securettys, or just on naming convention basis) who is
allowed to run X.  It's not done normally.
--

"And if you frisbee-throw a universe where does it go?" -- Steve Blunt.

KiboNumber == 1
 
 
 

Play a joke on X....

Post by stev » Sun, 30 Jun 1996 04:00:00




: >: ps If you are using X, then `xhost -` will prevent others from writing to
:       It's not hard to wrap startx in a script or program that checks (in the
: same manner as /etc/securettys, or just on naming convention basis) who is
: allowed to run X.  It's not done normally.

        You could always use the solution of setting an X group and only allow
startx (or whatever) to be executable by members of that group. There is
also a directive in etc/inittab that allows atleast one text only
terminal (i *think*)....

--
_____
steve\___________________
www.seas.upenn.edu/~sdm  |
___/_\_________/_\______/
   \_/         \_/

 
 
 

1. Yggdrasil Fall 94 Plug 'n' Play doesn't want to play.

I'm not able to boot and install the Fall 1994 Yggdrasil Linux CD-ROM
on my system. When I boot from the supplied floppy, LILO seems to load
the kernel OK, recognize my hardware devices properly during probing
and calculate my BogoMIPS for me, but the kernel crashes after trying
to mount filesystems. I've checked cabling, I/O address and IRQ
conflicts, tried removing unnecessary boards, made sure all of the
devices were configured as the manual suggested, etc., but nothing
helped. I'm pretty sure that everything I have is supposed to be
supported by the Yggdrasil kernel. Everything works OK under DOS, for
whatever that's worth.

From the error messages, it looks to me like the kernel isn't happy
about the block size on some device (the CD-ROM?), so it can't mount
the filesystem on the CD-ROM.

I booted Slackware Linux from a boot disk and root disk I borrowed
from a friend, and successfully partitioned my hard disk. His kernel
didn't have support for my CD-ROM compiled in, though, so I couldn't
get any further.

I've installed/maintained/used SunOS systems for years, but I'm new to
Linux, and I'm fresh out of ideas. Any help would be appreciated!

-------------

Here are the gory details:

My system configuration is:
        Intel Premiere II 90 MHz Pentium PCI motherboard with
                PCI EIDE, second IDE, 2 serial ports, par port and
                floppy i/f on board
        ATI mach32 video
        Sound Blaster 16 with CD-ROM interface and Sony CDU-33A drive
        3Com 3C509 ethernet board
        1G EIDE hard disk
        16M RAM

I typed "linux hd=2100,16,63" at the "boot:" prompt.

The part of the boot-time messages that seemed relevant to me said:

[stuff before here deleted]

Partition check:
  hda: WDC AC31000H, 1033MB w/128KB Cache, CHS=2100/16/63, MaxMult=16
  hda: hda1
RAMDISK: 104960 bytes, starting at 0x248b48
VFS: Disk change detected on device 15/0
ll_rw_block: only 2048-char blocks implemented (1024)
MINIX-fs: unable to read superblock
Unable to handle kernel NULL pointer dereference at virtual address
c0000000
current->tss.cr3 - 0001d000, %cr3 = 0001d000
*pde = 00102027
*pte = 00000027
Oops: 0000
[stack and register frame info deleted]

Thanks in advance for any advice....

--
Mark J. Blair   KE6MYK
Design Engineer
Silicon Systems, Inc.

2. help for unix filename size.

3. play mp3 using command play in RH8

4. trn: Setting NewsServer ? (Slackware]

5. Can't use 'play' to play .wav file

6. Where did Terminal Option go?

7. need "play" to play sound files

8. Unix - Frequently Asked Questions (Contents) [Frequent posting]

9. I can play CD but fail to play .wav

10. ATI Xpert@Play AGP vs. ATI Xpert@Play 98 AGP

11. "au-play" (plays *.au's thru speaker, no sound card needed)

12. Yggrasil's Plug and Play won't play.

13. A Joke?