[issue599] 1.9.0 reproducable panic

[Matthew Dillon]

:New submission from Peter Avalos <pavalos at theshell.com>:
:
:Here's a panic I'm getting with some pretty serious network (www) load, then 
:doing a netstat -an:
:
:Unread portion of the kernel message buffer:
:panic: m_copydata, negative off -1
:mp_lock = 00000000; cpuid = 0; lapic.id = 00000000
:boot() called on cpu#0
:
:syncing disks... 5
:done
:Uptime: 12d22h0m32s

    Woa.  You mean the panic occurs only when you do the netstat -an command
    under heavy network load?  It doesn't happen any other time?

    This is a really odd crash.  Somehow tp->snd_nxt has become less
    then tp->snd_una, causing 'off' to be calculated as -1.

 	 				-Matt