Memory leak in net80211 on FBSD 6.0

[Nate Nielsen]

I'm experiencing a memory leak in the net80211 code. I have two atheros
5213-A cards on two embedded systems running FreeBSD 6.0. They are setup
as IBSS (adhoc) stations. After roughly 15 seconds of ~14Mbps TCP
traffic (single stream) I promptly run out of memory:

> login: panic: kmem_malloc(4096): kmem_map too small: 25165824 total allocated
> Uptime: 3m0s
> Cannot dump. No dump device defined.
> Automatic reboot in 5 seconds - press a key on the console to abort
> Rebooting...

The boxes have 64MB of memory each.
vmstat -m reports the following just before the panic:

>          Type InUse MemUse HighUse Requests  Size(s)
> <snip>
>     80211node 20554 20554K       -    20559  512,1024

The cards are configured as follows (in other words, nothing special):

> ath0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>         inet 10.2.2.5 netmask 0xffffff00 broadcast 10.2.2.255
>         ether 00:15:6d:10:19:21
>         media: IEEE 802.11 Wireless Ethernet OFDM/24Mbps mode 11g <adhoc>
>         status: associated
>         ssid jumper channel 3 bssid 02:15:6d:10:19:21
>         authmode OPEN privacy OFF txpowmax 56 protmode CTS bintval 100

I've got this sorta thing in my kernel:

> device          wlan            # 802.11 support
> device          wlan_wep
> device          wlan_ccmp
> device          wlan_tkip
> device          wlan_xauth
> device          wlan_acl
> device          ath             # Atheros
> device          ath_hal
> device          ath_rate_onoe

I'll continue to hack away at this problem, but I don't have much
experience with the FreeBSD kernel. If anyone has any ideas, I'd love to
hear from you.

Cheers,
Nate