From owner-freebsd-bugs  Fri Oct  6 14:20: 8 2000
Delivered-To: freebsd-bugs@freebsd.org
Received: from freefall.freebsd.org (freefall.FreeBSD.org [216.136.204.21])
	by hub.freebsd.org (Postfix) with ESMTP id 02F2837B66C
	for <freebsd-bugs@FreeBSD.org>; Fri,  6 Oct 2000 14:20:01 -0700 (PDT)
Received: (from gnats@localhost)
	by freefall.freebsd.org (8.9.3/8.9.2) id OAA16981;
	Fri, 6 Oct 2000 14:20:00 -0700 (PDT)
	(envelope-from gnats@FreeBSD.org)
Received: by hub.freebsd.org (Postfix, from userid 32767)
	id 3576C37B502; Fri,  6 Oct 2000 14:16:02 -0700 (PDT)
Message-Id: <20001006211602.3576C37B502@hub.freebsd.org>
Date: Fri,  6 Oct 2000 14:16:02 -0700 (PDT)
From: jd@dynw.com
To: freebsd-gnats-submit@FreeBSD.org
X-Send-Pr-Version: www-1.0
Subject: kern/21791: Hang on FIN_WAIT_2
Sender: owner-freebsd-bugs@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.org


>Number:         21791
>Category:       kern
>Synopsis:       Hang on FIN_WAIT_2
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Oct 06 14:20:00 PDT 2000
>Closed-Date:
>Last-Modified:
>Originator:     Jim Dogopoulos
>Release:        4.1.1-S 3.5-S BSDi
>Organization:
dwc
>Environment:
>Description:
Connecting to certain machines tcp stacks causes hang on FIN_WAIT_2, which never times out.
>How-To-Repeat:
telnet 216.105.145.50 80 and quit.
It is a Novell-HTTP-Server/3.1R1 server.

look at netstat, FIN_WAIT_2 will stay. It gets worse though, I wrote some code to initiate >2048 connections, which filled up the mbufs on the fbsd-3.5-s test machine (4.x will obviously behave differently), and permanently denied further connections until reboot. This could possibly be used as a local DoS attack from an ordinary user on a shell server, but at the least, the occasional hung FIN_WAIT_2s are annoying to look at...

>Fix:
Perhaps timeout FIN_WAIT_2 sometime?


>Release-Note:
>Audit-Trail:
>Unformatted:


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-bugs" in the body of the message