Bug#651199: iwlwifi WPA-TKIP crypto failure after group rekeying

[Johannes Berg <johannes@sipsolutions.net>]

Hi Ben,

Thanks for the report.

On Mon, 2012-02-27 at 05:33 +0000, Ben Hutchings wrote:
> Several Debian users (cc'd) have reported a regression in iwlagn in
> Linux 3.1, not fixed in 3.2.  The full bug log is at:
> 
> http://bugs.debian.org/651199
> 
> To summarise, a WPA-TKIP managed connection stops passing traffic and
> the kernel log shows the message "WPA: Group rekeying".  This apparently
> doesn't happen if the connection is in heavy use at the time or with
> module parameter swcrypto=1.  WPA2 is not affected either.

I think this is due to my patch "iwlagn: rewrite HW crypto" which
accidentally broke key *removal* (of all things), which causes issues
when the first GTK is removed on the second rekeying.

This patch
http://git.kernel.org/?p=linux/kernel/git/iwlwifi/iwlwifi.git;a=commitdiff;h=5dcbf480473f6c3f06ad2426b7517038a2a18911

should fix it. Wey has sent it to John, but he hasn't picked it up yet
for some reason -- it's also marked for stable.

It'd be great to get confirmation that this is the problem, I'm not sure
I'll find time today to reproduce the problem.

johannes