Diddy Head Injury From Prison Fight with Jamaican Drug Lord Dudus

Diddy busted his head during a fight with another famous, or infamous, inmate ... a Jamaican drug lord known as "Dudus," and TMZ has learned the fight was over Diddy getting all the inmates in trouble.

Multiple sources inside Fort Dix FCI tell us ... Diddy and "Dudus" -- real name Christopher Coke -- came to blows last Friday, and Diddy got the worst of it ... suffering a head injury so severe, prison officials rushed him to an outside facility for treatment.

We're told the two men were fighting because Dudus, and many other inmates, are pissed at Diddy for getting exposed in that NBC News report about his luxurious life behind bars. As a result, prison officials have conducted at least 2 raids and confiscated cell phones from inmates ... including Dudus.

Now, while Diddy is clearly the biggest celebrity at Fort Dix, our sources describe Dudus -- who's been serving a 23-year sentence since 2012 -- as the real kingpin, and he's none too pleased all his fringe benefits vanished after the raids.

We're told after the fight ... both men were placed in the Special Housing Unit -- aka solitary confinement -- for 2 weeks' punishment. To be clear, Diddy was already in the SHU due to the NBC report, and the fight went down when he was out for his daily break.