I'm a coding noob. For the life of me I'm not able to figure out why the while loop is going infinitely? Any and all help is appreciated. Here is the code.

using System.Collections; using System.Collections.Generic; using UnityEngine;

public class LaserScript : MonoBehaviour {

 LineRenderer laser;
 int count;
 //Vector3[] laserPoints = new Vector3[10];

 void Start ()
 {
     laser = GetComponent<LineRenderer> ();
     laser.enabled = false;
     //laserPoints [2] = new Vector3 (10,0,5);
 }

 void Update () {
     if (Input.GetKeyDown (KeyCode.LeftControl)) 
     {
             StopCoroutine ("Firing");
             StartCoroutine ("Firing");
         //Debug.DrawRay (transform.position, transform.forward, Color.red);
     }
 }

 IEnumerator Firing()
 {
     laser.enabled = true;
     while (Input.GetKey(KeyCode.LeftControl))
     {
         Ray ray = new Ray (transform.position, transform.forward);
         RaycastHit hit;
         laser.positionCount = 10;
         laser.SetPosition (0, ray.origin);

         if (Physics.Raycast (ray, out hit, 100))
         {
             laser.SetPosition (1, hit.point);
             Debug.Log (hit.point);
             if (hit.collider.tag == "Mirror")
             {
                 laser.SetPosition (2, hit.point + 100.0f * Vector3.Reflect (transform.forward, hit.normal));
             }
         }
         else
             laser.SetPosition (1, ray.GetPoint (100));

         if (Input.GetKeyDown (KeyCode.Space))
             break;
     }
     yield return null;
     laser.enabled = false;
 }

}