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Date: Wed, 21 May 2003 10:03:08 +0800
From: Eugene Grosbein <eugen@kuzbass.ru>
To: "Saulius Menkeviius" <razzmatazz@mail.lt>
Cc: freebsd-stable@freebsd.org, net@freebsd.org,
	bug-followup@freebsd.org
Subject: Re: lots of sockets in TIME_WAIT
References: <E19IDku-0000CA-Et@midway.tamsa>

>Number:         52510
>Category:       kern
>Synopsis:       Re: lots of sockets in TIME_WAIT
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    ceri
>State:          closed
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue May 20 19:10:12 PDT 2003
>Closed-Date:    Sun May 25 11:00:45 PDT 2003
>Last-Modified:  Wed Aug 13 13:07:10 PDT 2003
>Originator:     Eugene Grosbein
>Release:        
>Organization:
>Environment:
>Description:
 "Saulius Menkeviius" wrote:
 > 
 >         Hi there,
 > 
 > I have some DDOS(?) attack on my router going where my apache HTTP
 > server is flooded with short-timed connections from some host. This
 > results in LOTS of sockets in TIME_WAIT/LAST_ACK/CLOSING states and
 > eventually I'm out of mbufs, which, consequently means I can't even
 > connect to the router from LAN. The kern.ipc.nmbclusters is 2560, (I
 > guess high enough for router with DSL connection).
 >         After some time all mbufs are depleted (system says "All mbuf
 > cluster exhausted"). However, unexpectedly the system panics shortly
 > in about 10 minutes (+/-) with:
 > /kernel: All mbuf cluster exhausted, please see tuning(7)
 > /kernel: looutput: mbuf allocation failed
 > /kernel: panic: sbappendaddr
 > /kernel:
 > /kernel: syncing disks....
 > .
 > .
 >         I don't think this behaviour (a panic) is normal. This crash is
 > happens often when I'm under such attack and I guess I can easily
 > give crash dump, kgdb output or something like, if you need.
 >         System is running 4.8-RELEASE, on iPentium166/mmx with 64MB of RAM.
 > 4 NICs, BRIDGE on two of them.
 > 
 >         Thanks for any response..
 
 I agree with you. I've got crashdump for mbuf-related kernel panic 
 (sbappendaddr), see http://www.FreeBSD.org/cgi/query-pr.cgi?pr=kern/50803
 I believe a kernel must not panic due to DoS.
 
 Eugene Grosbein
>How-To-Repeat:
>Fix:
>Release-Note:
>Audit-Trail:
State-Changed-From-To: open->closed 
State-Changed-By: ceri 
State-Changed-When: Sun May 25 10:59:40 PDT 2003 
State-Changed-Why:  
Looks like a follow-up to kern/50803, but actually isn't. 


Responsible-Changed-From-To: gnats-admin->ceri 
Responsible-Changed-By: ceri 
Responsible-Changed-When: Sun May 25 10:59:40 PDT 2003 
Responsible-Changed-Why:  
Take from gnats-admin. 

http://www.freebsd.org/cgi/query-pr.cgi?pr=52510 
>Unformatted:
