iwlwifi: tighten boundary checks

The driver assumes certain sizes and lengths aren't crossed in some
places.  Make sure this indeed happens.

Found by Klocwork.
Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/fw/dbg.c

@@ -835,6 +835,8 @@ _iwl_fw_error_dump(struct iwl_fw_runtime *fwrt,
 	if (!fwrt->trans->cfg->dccm_offset || !fwrt->trans->cfg->dccm_len) {
 		const struct fw_img *img;
 
+		if (fwrt->cur_fw_img >= IWL_UCODE_TYPE_MAX)
+			return NULL;
 		img = &fwrt->fw->img[fwrt->cur_fw_img];
 		sram_ofs = img->sec[IWL_UCODE_SECTION_DATA].offset;
 		sram_len = img->sec[IWL_UCODE_SECTION_DATA].len;

drivers/net/wireless/intel/iwlwifi/mvm/tx.c

@@ -1024,7 +1024,12 @@ static void iwl_mvm_tx_airtime(struct iwl_mvm *mvm,
 			       int airtime)
 {
 	int mac = mvmsta->mac_id_n_color & FW_CTXT_ID_MSK;
-	struct iwl_mvm_tcm_mac *mdata = &mvm->tcm.data[mac];
+	struct iwl_mvm_tcm_mac *mdata;
+
+	if (mac >= NUM_MAC_INDEX_DRIVER)
+		return;
+
+	mdata = &mvm->tcm.data[mac];
 
 	if (mvm->tcm.paused)
 		return;
@@ -1035,14 +1040,21 @@ static void iwl_mvm_tx_airtime(struct iwl_mvm *mvm,
 	mdata->tx.airtime += airtime;
 }
 
-static void iwl_mvm_tx_pkt_queued(struct iwl_mvm *mvm,
-				  struct iwl_mvm_sta *mvmsta, int tid)
+static int iwl_mvm_tx_pkt_queued(struct iwl_mvm *mvm,
+				 struct iwl_mvm_sta *mvmsta, int tid)
 {
 	u32 ac = tid_to_mac80211_ac[tid];
 	int mac = mvmsta->mac_id_n_color & FW_CTXT_ID_MSK;
-	struct iwl_mvm_tcm_mac *mdata = &mvm->tcm.data[mac];
+	struct iwl_mvm_tcm_mac *mdata;
+
+	if (mac >= NUM_MAC_INDEX_DRIVER)
+		return -EINVAL;
+
+	mdata = &mvm->tcm.data[mac];
 
 	mdata->tx.pkts[ac]++;
+
+	return 0;
 }
 
 /*
@@ -1162,7 +1174,9 @@ static int iwl_mvm_tx_mpdu(struct iwl_mvm *mvm, struct sk_buff *skb,
 
 	spin_unlock(&mvmsta->lock);
 
-	iwl_mvm_tx_pkt_queued(mvm, mvmsta, tid == IWL_MAX_TID_COUNT ? 0 : tid);
+	if (iwl_mvm_tx_pkt_queued(mvm, mvmsta,
+				  tid == IWL_MAX_TID_COUNT ? 0 : tid))
+		goto drop;
 
 	return 0;
 

drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c

@@ -214,7 +214,11 @@ static int iwl_pcie_gen2_set_tb(struct iwl_trans *trans,
 {
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	int idx = iwl_pcie_gen2_get_num_tbs(trans, tfd);
-	struct iwl_tfh_tb *tb = &tfd->tbs[idx];
+	struct iwl_tfh_tb *tb;
+
+	if (WARN_ON(idx >= IWL_NUM_OF_TBS))
+		return -EINVAL;
+	tb = &tfd->tbs[idx];
 
 	/* Each TFD can point to a maximum max_tbs Tx buffers */
 	if (le16_to_cpu(tfd->num_tbs) >= trans_pcie->max_tbs) {