iwlwifi: mvm: fix RFH config command with >=10 CPUs

If we have >=10 (logical) CPUs, our command size exceeds the
internal buffer size and the command fails; fix that by using
IWL_HCMD_DFL_NOCOPY for the command that's allocated anyway.

While at it, also fix the leak of cmd, and use struct_size()
to calculate its size.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Fixes: 8edbfaa1 ("iwlwifi: mvm: configure multi RX queue")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

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

@@ -127,13 +127,17 @@ static int iwl_send_rss_cfg_cmd(struct iwl_mvm *mvm)
 
 static int iwl_configure_rxq(struct iwl_mvm *mvm)
 {
-	int i, num_queues, size;
+	int i, num_queues, size, ret;
 	struct iwl_rfh_queue_config *cmd;
+	struct iwl_host_cmd hcmd = {
+		.id = WIDE_ID(DATA_PATH_GROUP, RFH_QUEUE_CONFIG_CMD),
+		.dataflags[0] = IWL_HCMD_DFL_NOCOPY,
+	};
 
 	/* Do not configure default queue, it is configured via context info */
 	num_queues = mvm->trans->num_rx_queues - 1;
 
-	size = sizeof(*cmd) + num_queues * sizeof(struct iwl_rfh_queue_data);
+	size = struct_size(cmd, data, num_queues);
 
 	cmd = kzalloc(size, GFP_KERNEL);
 	if (!cmd)
@@ -154,10 +158,14 @@ static int iwl_configure_rxq(struct iwl_mvm *mvm)
 		cmd->data[i].fr_bd_wid = cpu_to_le32(data.fr_bd_wid);
 	}
 
-	return iwl_mvm_send_cmd_pdu(mvm,
-				    WIDE_ID(DATA_PATH_GROUP,
-					    RFH_QUEUE_CONFIG_CMD),
-				    0, size, cmd);
+	hcmd.data[0] = cmd;
+	hcmd.len[0] = size;
+
+	ret = iwl_mvm_send_cmd(mvm, &hcmd);
+
+	kfree(cmd);
+
+	return ret;
 }
 
 static int iwl_mvm_send_dqa_cmd(struct iwl_mvm *mvm)