iwlwifi: serialize station management actions

We are seeing some race conditions between incoming station management
requests (station add/remove) and the internal unassoc RXON command that
modifies station table. Modify these flows to require the mutex to be held
and thus serializing them.

This fixes http://bugzilla.intellinuxwireless.org/show_bug.cgi?id=2207

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-sta.c b/drivers/net/wireless/iwlwifi/iwl-sta.c
index 83a26361a9b5..c27c13fbb1ae 100644
--- a/drivers/net/wireless/iwlwifi/iwl-sta.c
+++ b/drivers/net/wireless/iwlwifi/iwl-sta.c
@@ -1373,10 +1373,14 @@ int iwl_mac_sta_remove(struct ieee80211_hw *hw,
 
         IWL_DEBUG_INFO(priv, "received request to remove station %pM\n",
                         sta->addr);
+        mutex_lock(&priv->mutex);
+        IWL_DEBUG_INFO(priv, "proceeding to remove station %pM\n",
+                        sta->addr);
         ret = iwl_remove_station(priv, sta_common->sta_id, sta->addr);
         if (ret)
                 IWL_ERR(priv, "Error removing station %pM\n",
                         sta->addr);
+        mutex_unlock(&priv->mutex);
         return ret;
 }
 EXPORT_SYMBOL(iwl_mac_sta_remove);