Help with grabbing object code

Hey there! I am working on grabbing some objects. I am using this script and my problem is that when i grab something it can go through walls floor etc, as it doesn't have box collider. Any solution to that?

 using UnityEngine;
 using System.Collections;
 
 public class Grab : MonoBehaviour {
     
     GameObject grabbedObject;
     float grabbedObjectSize;
     GameObject GetMouseHoverObject(float range)
     {
         Vector3 position = gameObject.transform.position;
         RaycastHit raycastHit;
         Vector3 target = position + Camera.main.transform.forward * range;
         
         if (Physics.Linecast(position, target, out raycastHit))
             return raycastHit.collider.gameObject;
         return null;
         
     }
     
     void TryGrabObject(GameObject grabObject)
     {
         if (grabObject == null || !CanGrab(grabObject))
             return;
         grabbedObject = grabObject;
         grabbedObjectSize = grabObject.GetComponent<Renderer>().bounds.size.magnitude;
     }
     bool CanGrab(GameObject canidate)
     {
         return canidate.GetComponent<Rigidbody> () != null;
     }
     void DropObject()
     {
         if (grabbedObject == null)
             return;
         
         
         if (grabbedObject.GetComponent<Rigidbody> () != null)
             grabbedObject.GetComponent<Rigidbody> ().velocity = Vector3.zero;
         grabbedObject = null;
     }
     
     void Update () {
         if (Input.GetMouseButtonDown(1)) 
         {
             if (grabbedObject == null)
                 TryGrabObject(GetMouseHoverObject(5));
             else
                 DropObject();
         }
         
         if (grabbedObject != null) 
         {
             Vector3 newPosition = gameObject.transform.position+Camera.main.transform.forward*grabbedObjectSize;
             grabbedObject.transform.position = newPosition;
         }
         
     }
 }