Ruling on telling bosses about a worker who is doing something wrong or is negligent
Question

                If I find out that one of the workers is falling short in his work or is doing something wrong, is it permissible for me to tell the boss about that?
Praise be to Allah.What is prescribed in sharee’ah is for you to advise him 
          and point him in the right direction, and urge him to fulfil the trust. 
          If he does not respond, then you have to refer the matter to the appropriate 
          people, because Allaah says (interpretation of the meaning); 
“Help you one another in Al Birr and At Taqwa (virtue, righteousness 
          and piety)” [al-Maa’idah 5:2] 
 And the Prophet  
          (peace and blessings of Allaah be upon him) said: 
“Religion is sincerity (naseehah)” three times. It was asked, 
          “To whom, O Messenger of Allaah?” He said, “To Allaah, to His Book, 
          to His Messenger, to the leaders of the Muslims and to their common 
          folk.” (Narrated by Muslim in his Saheeh). 
And Allaah is the Source of strength.