[142/200] mac80211: fix deauth before assoc

Greg KH
2010-07-01T21:37:35Z

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

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

From: Johannes Berg <johannes.berg@intel.com>

commit b054b747a694927879c94dd11af54d04346aed7d upstream.

When we receive a deauthentication frame before
having successfully associated, we neither print
a message nor abort assocation. The former makes
it hard to debug, while the latter later causes
a warning in cfg80211 when, as will typically be
the case, association timed out.

This warning was reported by many, e.g. in
https://bugzilla.kernel.org/show_bug.cgi?id=15981,
but I couldn't initially pinpoint it. I verified
the fix by hacking hostapd to send a deauth frame
instead of an association response.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Tested-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
net/mac80211/mlme.c | 40 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 38 insertions(+), 2 deletions(-)

--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1530,9 +1530,45 @@ static void ieee80211_sta_rx_queued_mgmt
mutex_unlock(&ifmgd->mtx);

if (skb->len >= 24 + 2 /* mgmt + deauth reason */ &&
- (fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_DEAUTH)
- cfg80211_send_deauth(sdata->dev, (u8 *)mgmt, skb->len);
+ (fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_DEAUTH) {
+ struct ieee80211_local *local = sdata->local;
+ struct ieee80211_work *wk;
+
+ mutex_lock(&local->work_mtx);
+ list_for_each_entry(wk, &local->work_list, list) {
+ if (wk->sdata != sdata)
+ continue;
+
+ if (wk->type != IEEE80211_WORK_ASSOC)
+ continue;
+
+ if (memcmp(mgmt->bssid, wk->filter_ta, ETH_ALEN))
+ continue;
+ if (memcmp(mgmt->sa, wk->filter_ta, ETH_ALEN))
+ continue;

+ /*
+ * Printing the message only here means we can't
+ * spuriously print it, but it also means that it
+ * won't be printed when the frame comes in before
+ * we even tried to associate or in similar cases.
+ *
+ * Ultimately, I suspect cfg80211 should print the
+ * messages instead.
+ */
+ printk(KERN_DEBUG
+ "%s: deauthenticated from %pM (Reason: %u)\n",
+ sdata->name, mgmt->bssid,
+ le16_to_cpu(mgmt->u.deauth.reason_code));
+
+ list_del_rcu(&wk->list);
+ free_work(wk);
+ break;
+ }
+ mutex_unlock(&local->work_mtx);
+
+ cfg80211_send_deauth(sdata->dev, (u8 *)mgmt, skb->len);
+ }
out:
kfree_skb(skb);
}