kern/157449: MAC address conflict causes system to freeze

[Yuri]

>Number:         157449
>Category:       kern
>Synopsis:       MAC address conflict causes system to freeze
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue May 31 01:10:09 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Yuri
>Release:        8.2-STABLE
>Organization:
n/a
>Environment:
>Description:
I had a bug in my setup script that was setting the same MAC address to several computers. This situation of course is not normal and should not normally occur.

But I noticed the side effect that causes me to worry:
8.2-STABLE host was periodically freezing in such situation.

My understanding is that such situation will cause all packets sent to this MAC address be accepted by every host in conflict and for example many garbage TCP packets will arrive to each machine. But why should it freeze the system?

It looks like there is some bug in the code rejecting garbage traffic and my setup exposed it.

This could also be a security issue when some other host on the same network can cause FreeBSD to freeze by sending some rogue packets to it.

I should also note that I am talking about the wireless device ath0 and passwordless WEP network. 
>How-To-Repeat:

>Fix:


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