RE: Linux 2.4.27 SECURITY BUG - TCP Local and REMOTE(verified)Denial of Service Attack

Wolfpaw - Dale Corse
2004-09-12T18:42:06Z

Hi Alan,

My inetd is not the old one, it is in Slackware 10.0..
apparently 1.79s, still works here. (the s added by
The slackware group according to the readme:

/* $Slackware: inetd.c 1.79s 2001/02/06 13:18:00 volkerdi Exp $ */
/* $OpenBSD: inetd.c,v 1.79 2001/01/30 08:30:57 deraadt Exp $ */
/* $NetBSD: inetd.c,v 1.11 1996/02/22 11:14:41 mycroft Exp $ */
/*

It still dies pretty fast :( Willy is probably right, in that
the bug is application level in this case. Can you explain
though, how it is appropriate to have no timeout on CLOSE_WAIT.
Lets assume (such as the case with the mysql bug), that it is
created, and for some reason never addressed.. The end case being
mysql reporting "Too many Connections". That would make me assume
these connections are still "alive" (perhaps I am assuming wrong?)
and could still cause issues with other services, if the volume of
them was to get too high.

It still seems prudent to me to have some kind of timeout (2 hours,
or something?) to have it expuldge the connection, because obviously,
it isn't going to voluntarily close.

This bug also exists with Apache, the default config of SSH,
and anything controlled by inetd. This is the vast majority of
popular services on a regular internet server.. That is bad, no?

D.

> -----Original Message-----
> From: Alan Cox [mailto:alan@lxorguk.ukuu.org.uk]
> Sent: Sunday, September 12, 2004 11:17 AM
> To: Willy Tarreau
> Cc: Wolfpaw - Dale Corse; peter@mysql.com; Linux Kernel
> Mailing List; netdev@oss.sgi.com
> Subject: Re: Linux 2.4.27 SECURITY BUG - TCP Local and
> REMOTE(verified)Denial of Service Attack
>
>
> On Sul, 2004-09-12 at 18:59, Willy Tarreau wrote:
> > The problem is within inetd. In my case it could be because it was a
> > bit old (1999), but since you have it too,
>
> Ancient inetd had several fd leak bugs fixed over time and
> some other problems with built in services. Not much of a
> suprise that a 1999 inetd has it.
>
> Alan
>
>
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