iwlwifi: mvm: avoid possible access out of array.

The value in txq_id can be out of array scope,
validate it before accessing the array.

Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Fixes: cf961e16620f ("iwlwifi: mvm: support dqa-mode agg on non-shared queue")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index 09f294c..5f42897 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -2702,7 +2702,7 @@ int iwl_mvm_sta_tx_agg_start(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
        struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
        struct iwl_mvm_tid_data *tid_data;
        u16 normalized_ssn;
-       int txq_id;
+       u16 txq_id;
        int ret;
 
        if (WARN_ON_ONCE(tid >= IWL_MAX_TID_COUNT))
@@ -2744,17 +2744,24 @@ int iwl_mvm_sta_tx_agg_start(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
         */
        txq_id = mvmsta->tid_data[tid].txq_id;
        if (txq_id == IWL_MVM_INVALID_QUEUE) {
-               txq_id = iwl_mvm_find_free_queue(mvm, mvmsta->sta_id,
-                                                IWL_MVM_DQA_MIN_DATA_QUEUE,
-                                                IWL_MVM_DQA_MAX_DATA_QUEUE);
-               if (txq_id < 0) {
-                       ret = txq_id;
+               ret = iwl_mvm_find_free_queue(mvm, mvmsta->sta_id,
+                                             IWL_MVM_DQA_MIN_DATA_QUEUE,
+                                             IWL_MVM_DQA_MAX_DATA_QUEUE);
+               if (ret < 0) {
                        IWL_ERR(mvm, "Failed to allocate agg queue\n");
                        goto out;
                }
 
+               txq_id = ret;
+
                /* TXQ hasn't yet been enabled, so mark it only as reserved */
                mvm->queue_info[txq_id].status = IWL_MVM_QUEUE_RESERVED;
+       } else if (WARN_ON(txq_id >= IWL_MAX_HW_QUEUES)) {
+               ret = -ENXIO;
+               IWL_ERR(mvm, "tid_id %d out of range (0, %d)!\n",
+                       tid, IWL_MAX_HW_QUEUES - 1);
+               goto out;
+
        } else if (unlikely(mvm->queue_info[txq_id].status ==
                            IWL_MVM_QUEUE_SHARED)) {
                ret = -ENXIO;