Re: [grsec] Linux 2.4.27 SECURITY BUG - TCP Local (probable Remote) Denial of Service

[Adam Majer <adamm@galacticasoftware.com>]

Wolfpaw - Dale Corse wrote:

>Greetings,
>
> My apologies if this is to the wrong place - it happens to be the
>first kernel bug I have found (or what appears to be one), and I'm
>not entirely sure how to properly inform the Linux community about
>it. 
>
>Anyway - on to the bug :)
>==========================
>Severity: HIGH
>Title: KERNEL: TCP Local (probable remote) Denial of Service
>Date: September 11, 2004
>  
>

Actually, it seems that the sockets that are not closing properly are
the ones opened by your proof of concept code, *NOT* the server. The
servers (mysql and Apache), close their sockets properly. I could verify
this over a network. Locally, I got

tcp        0      0 192.168.53.2:41440      192.168.53.1:3306      
TIME_WAIT
tcp        0      0 192.168.53.2:41442      192.168.53.1:3306      
TIME_WAIT
tcp        0      0 192.168.53.2:41443      192.168.53.1:3306      
TIME_WAIT
tcp        0      0 192.168.53.2:41452      192.168.53.1:3306      
TIME_WAIT
tcp        0      0 192.168.53.2:41468      192.168.53.1:80        
TIME_WAIT
tcp        0      0 192.168.53.2:41441      192.168.53.1:80        
TIME_WAIT
tcp        0      0 192.168.53.2:41447      192.168.53.1:80        
TIME_WAIT
tcp        0      0 192.168.53.2:41444      192.168.53.1:80         TIME

etc..

But on the server, only 1 or two ESTABISHED entries, nothing more.

I don't see much of a DOS, except maybe to DOS a localhost. And you can
do that already.

>The socket table looks like this while it is going on:
>
>http://www.ancients.org/LG.txt
>(it is 29,000+ lines, so I didn't put it here)
>  
>


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