From owner-freebsd-hackers  Sat Nov 23 21:26:19 1996
Return-Path: owner-hackers
Received: (from root@localhost)
          by freefall.freebsd.org (8.7.5/8.7.3) id VAA28980
          for hackers-outgoing; Sat, 23 Nov 1996 21:26:19 -0800 (PST)
Received: from spiff.cc.iastate.edu (spiff.cc.iastate.edu [129.186.142.89])
          by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id VAA28972
          for <hackers@freefall.freebsd.org>; Sat, 23 Nov 1996 21:26:16 -0800 (PST)
Received: by spiff.cc.iastate.edu with sendmail-5.65 
	id <AA18429@spiff.cc.iastate.edu>; Sat, 23 Nov 1996 23:26:15 -0600
Message-Id: <9611240526.AA18429@spiff.cc.iastate.edu>
To: hackers@freefall.freebsd.org
Reply-To: graphix@iastate.edu
Subject: ping and freebsd crashes
Date: Sat, 23 Nov 1996 23:26:15 CST
From: Kent Vander Velden <graphix@iastate.edu>
Sender: owner-hackers@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk


  After reading the url that was mentioned earlier about ping I tried to
crash an Irix 5.2 machine.  I used OSF/1 v3.2 'ping -q -f -l 200 -s
5000'.  The network appeared to take quite a beating.  Sort of related
to wanting to try this was that I have been working on a network packet
analyzer and wanted to see how much of a load this pinging would cause.
The network analyzer runs on a freebsd machine and uses libpcap.  The
interesting part of all this is the freebsd machine crashed and in fact
crashed really hard.  In the worst case a user's home directory and 50%
of /bin and misc. was removed.  I must point out that the freebsd
machine was not being pinged nor was it doing the pinging it was simply
a machine on the network with it's interface running in promiscuous mode.
I also tried tcpdump to make sure that it was not my program that was
causing problems with the same result.

  There where many 
"lnc0: missed packet -- no receive buffer"
and 
"lnc0: Framming error"
messages with the killer appearing to be
"panic brelse: free buffer onto another queue?"

  Perhaps this problems is no longer present.  I wish I could tell you
the version of the os that I had but that was lost when I installed the
961014 snap to reclaim the binaries lost during the crashes.  I will try
to find if this problem is present with this snapshot as soon as I am in
a position that I will not lose network connectivity if the machine does
not come back up.

  This would seem like a rather serious problem.
 
  Thanks.

---
Kent Vander Velden
graphix@iastate.edu