From: Johannes Berg <johannes.berg@intel.com>
Date: Mon, 3 Jan 2011 18:42:24 +0000 (+0100)
Subject: mac80211: add missing synchronize_rcu
X-Git-Tag: v2.6.36.4~132
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5efbd432c45ff09f0cafd8f1329693d3fb802fff;p=karo-tx-linux.git

mac80211: add missing synchronize_rcu

commit d2460f4b2fa6dbdeec800414f9cf5b1fc8b71197 upstream.

commit ad0e2b5a00dbec303e4682b403bb6703d11dcdb2
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Tue Jun 1 10:19:19 2010 +0200

    mac80211: simplify key locking

removed the synchronization against RCU and thus
opened a race window where we can use a key for
TX while it is already freed. Put a synchronisation
into the right place to close that window.

Reported-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---

diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index 1b9d87ed143a..3f76484221a2 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -323,6 +323,12 @@ static void __ieee80211_key_destroy(struct ieee80211_key *key)
 	if (!key)
 		return;
 
+	/*
+	 * Synchronize so the TX path can no longer be using
+	 * this key before we free/remove it.
+	 */
+	synchronize_rcu();
+
 	if (key->local)
 		ieee80211_key_disable_hw_accel(key);