bin/98218: wpa_supplicant blacklist not working

[Kevin Oberman]

>Number:         98218
>Category:       bin
>Synopsis:       wpa_supplicant blacklist not working
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed May 31 14:50:15 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Kevin Oberman
>Release:        FreeBSD 7.0-CURRENT i386
>Organization:
ESnet-The Energy Sciences Network
>Environment:
System: FreeBSD slan.es.net 7.0-CURRENT FreeBSD 7.0-CURRENT #15: Tue May 23 14:19:22 PDT 2006 root at slan.es.net:/usr/obj/usr/src/sys/IBM-T43 i386


	
>Description:
	If multiple BSSes match an entry in the wpa_supplicant.conf
file, it is possible that the BSS chosen will not associate, but
instead of blacklisting the BSS and trying another, the wpa_supplicant
continues to try to attach to the unusable BSS with a new attempt every
10 seconds.

This was observed in a non-secured situation. That is there were
multiple BSSes showing in the scan and the first had a very low signal
strength. The supplicant would try to associate with that BSS, but
could not. ifconfig always showed the interface with no carrier.

I believe that the supplicant should have blacklisted that BSS and
tried another on the list, but would keep trying the same one over and
over. Restarting the supplicant would cause a new list of BSSes to be
generated which was identical to the first except for order. If the
first BSS on the list proved functional, association would take place
and things progressed normally. If the first entry would not
associate, the same thing, re-attempts to associate with the same BSS
every 10 seconds would repeat.

For the record, the configuration file in question was my generic
wireless of:
network={
	ssid=""
	key_mgmt=NONE
	priority=0
}

My wireless card is an Atheros 5212, although inspection of the code
leads me to believe that this is not related to the card chosen.

>How-To-Repeat:
	Attempt to use the wpa_supplicant in an environment where
several APs are available, some of which have poor signals and will
not associate.
>Fix:
Modify the supplicant to blacklist a BSS that fails to associate so
that other available APs will be tried.


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