mac80211: fix a race condition during key deletion

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@24895 3c298f89-4303-0410-b956-a3cf2f4a3e73

diff --git a/package/mac80211/patches/320-mac80211_fix_key_del_race.patch b/package/mac80211/patches/320-mac80211_fix_key_del_race.patch
new file mode 100644 (file)
index 0000000..52803e1
--- /dev/null
+++ b/package/mac80211/patches/320-mac80211_fix_key_del_race.patch
@@ -0,0 +1,32 @@
+From: Johannes Berg <johannes.berg@intel.com>
+
+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>
+Cc: stable@kernel.org [2.6.36+]
+Signed-off-by: Johannes Berg <johannes.berg@intel.com>
+
+--- a/net/mac80211/key.c
++++ b/net/mac80211/key.c
+@@ -382,6 +382,12 @@ static void __ieee80211_key_destroy(stru
+       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);
+