iwlwifi: fix and add missing sta_lock usage

There are a few places where sta_lock is used, but the
station information protected by it is accessed outside
of the lock. Address this in two ways, if the access
won't sleep then just move the access into the lock, if
the access can sleep then copy the needed station
information to the stack to be accessed without risk of
it changing while access in progress.

Additionally, a number of other places access station
station information without holding the sta_lock, fix
those as well.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
index 5f07bc2e14e9..4857b5f62481 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
@@ -184,6 +184,7 @@ static void iwlagn_rx_reply_tx(struct iwl_priv *priv,
         int tid;
         int sta_id;
         int freed;
+        unsigned long flags;
 
         if ((index >= txq->q.n_bd) || (iwl_queue_used(&txq->q, index) == 0)) {
                 IWL_ERR(priv, "Read index for DMA queue txq_id (%d) index %d "
@@ -199,9 +200,10 @@ static void iwlagn_rx_reply_tx(struct iwl_priv *priv,
         tid = (tx_resp->ra_tid & IWL50_TX_RES_TID_MSK) >> IWL50_TX_RES_TID_POS;
         sta_id = (tx_resp->ra_tid & IWL50_TX_RES_RA_MSK) >> IWL50_TX_RES_RA_POS;
 
+        spin_lock_irqsave(&priv->sta_lock, flags);
         if (txq->sched_retry) {
                 const u32 scd_ssn = iwlagn_get_scd_ssn(tx_resp);
-                struct iwl_ht_agg *agg = NULL;
+                struct iwl_ht_agg *agg;
 
                 agg = &priv->stations[sta_id].tid[tid].agg;
 
@@ -256,6 +258,7 @@ static void iwlagn_rx_reply_tx(struct iwl_priv *priv,
         iwlagn_txq_check_empty(priv, sta_id, tid, txq_id);
 
         iwl_check_abort_status(priv, tx_resp->frame_count, status);
+        spin_unlock_irqrestore(&priv->sta_lock, flags);
 }
 
 void iwlagn_rx_handler_setup(struct iwl_priv *priv)
@@ -1533,6 +1536,8 @@ int iwlagn_manage_ibss_station(struct iwl_priv *priv,
 void iwl_free_tfds_in_queue(struct iwl_priv *priv,
                             int sta_id, int tid, int freed)
 {
+        WARN_ON(!spin_is_locked(&priv->sta_lock));
+
         if (priv->stations[sta_id].tid[tid].tfds_in_queue >= freed)
                 priv->stations[sta_id].tid[tid].tfds_in_queue -= freed;
         else {