security question

[mabbas <mabbas@linux.intel.com>]

Hi

When I connect to an AP with wpa, then I receive deauth frame, 
ieee80211_rx_mgmt_deauth will be called, which will call 
ieee80211_set_associated(dev, ifsta, 0); to disconnect. In function 
ieee80211_set_associated, it calls wireless_send_event with SIOCGIWAP 
event and memset(wrqu.ap_addr.sa_data, 0, ETH_ALEN). wpa_supplicant will 
receives this event then call mac80211 to remove any old security key, 
the problem it will pass 00:00:00:00:00:00 as station address. 
ieee80211_set_encryption will fail since there are no station with 
00:00:00:00:00:00. This will leave the old key which causes the problems 
in the next reconnection.

Below is the work around to this problem, I am not very familiar with 
security in mac80211 so I appreciate any comment on how to fix this 
problem the right way.

Mohamed

diff --git a/net/mac80211/ieee80211_ioctl.c b/net/mac80211/ieee80211_ioctl.c
index c84a26e..e08df5e 100644
--- a/net/mac80211/ieee80211_ioctl.c
+++ b/net/mac80211/ieee80211_ioctl.c
@@ -97,7 +97,10 @@ static int ieee80211_set_encryption(struct net_device *dev, u8 *sta_addr,
 			return -EINVAL;
 		}
 
-		sta = sta_info_get(local, sta_addr);
+		if (is_zero_ether_addr(sta_addr))
+			sta = sta_info_get(local, sdata->u.sta.bssid);
+		else
+			sta = sta_info_get(local, sta_addr);
 		if (!sta) {
 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 			printk(KERN_DEBUG "%s: set_encrypt - unknown addr "