3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stanislaw Gruszka <redacted>

commit 1140afa862842ac3e56678693050760edc4ecde9 upstream.

Since:

commit 816c04fe7ef01dd9649f5ccfe796474db8708be5
Author: Christian Lamparter [off-list ref]
Date:   Sat Apr 30 15:24:30 2011 +0200

    mac80211: consolidate MIC failure report handling

is possible to that we dereference rx->key == NULL when driver set
RX_FLAG_MMIC_STRIPPED and not RX_FLAG_IV_STRIPPED and we are in
promiscuous mode. This happen with rt73usb and rt61pci at least.

Before the commit we always check rx->key against NULL, so I assume
fix should be done in mac80211 (also mic_fail path has similar check).

References:
https://bugzilla.redhat.com/show_bug.cgi?id=769766
http://rt2x00.serialmonkey.com/pipermail/users_rt2x00.serialmonkey.com/2012-January/004395.html

Reported-by: Stuart D Gathman <redacted>
Reported-by: Kai Wohlfahrt <redacted>
Signed-off-by: Stanislaw Gruszka <redacted>
Signed-off-by: John W. Linville <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 net/mac80211/wpa.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c

@@ -109,7 +109,7 @@ ieee80211_rx_h_michael_mic_verify(struct
 		if (status->flag & RX_FLAG_MMIC_ERROR)
 			goto mic_fail;
 
-		if (!(status->flag & RX_FLAG_IV_STRIPPED))
+		if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key)
 			goto update_iv;
 
 		return RX_CONTINUE;