iwlwifi: add missing rcu_read_lock

Using ieee80211_find_sta() needs to be under
RCU read lock, which iwlwifi currently misses,
so fix it.

Cc: stable@kernel.org
Reported-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
index c402bfc..a732f10 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
@@ -1125,6 +1125,7 @@ static void iwlagn_tx_status(struct iwl_priv *priv, struct sk_buff *skb)
        struct ieee80211_sta *sta;
        struct iwl_station_priv *sta_priv;
 
+       rcu_read_lock();
        sta = ieee80211_find_sta(priv->vif, hdr->addr1);
        if (sta) {
                sta_priv = (void *)sta->drv_priv;
@@ -1133,6 +1134,7 @@ static void iwlagn_tx_status(struct iwl_priv *priv, struct sk_buff *skb)
                    atomic_dec_return(&sta_priv->pending_frames) == 0)
                        ieee80211_sta_block_awake(priv->hw, sta, false);
        }
+       rcu_read_unlock();
 
        ieee80211_tx_status_irqsafe(priv->hw, skb);
 }