DJ Khalil: “I had this vocal of Kobe saying, ’Hold  up, wait a minute.’ I had that line and I saved it for like a year  because I knew it could be a dope club record for whoever. I remember I  was in the studio and I was playing the vocals, and Dre was like, 'Yo,  who is that?' I was like, ’That's Kobe.’ And he was like, 'Yo, that's a  hit already.' So I just started making the beat around it. We recorded  another hook before they put Akon on it, and another singer named  Blackthoven did the bridge. So we had a bunch of parts to it and I sent  it over to Dre. I still have the text in my phone where Dre was like,  'Yo, this ’Kush’ beat is incredible!' He was really excited about it  because he knew it was just a good party record. I'm not really known  for [party records], but that was my attempt for Dre. He just wanted a  buzz single. So I worked on that for a minute. We tried so many hooks on  that. That record went through so many stages.
“We actually sped it up  because it was much slower [originally]. But  Dre was like, 'We gotta  speed the joint up.' I remember Dre invited me  to the studio and he was  like, 'Yo, I want you to come listen to the  record.' So I listened to  it and he gave me a copy of it. There was just  so many things he added  to it, I was like, ’Wow, it doesn't even sound  like the record  anymore.’ [Laughs.] I was so married to the  original one. Dre  and I never argue, but I was like, ’I don't know man  about the new  hi-hats. I don't know man. Maybe you should give me a shot  at mixing  it.’ He gave me a shot at mixing it, but we ended up going  with his mix  because he knows how to mix for radio. I don't really know  how to do  that, so I learned a really important lesson: Dr. Dre knows  what he's  doing. [Laughs.]
”I've been at Aftermath for so long, when Dre first signed me he was already talking about Detox. I was like, ’Detox?   What is that?’ And he was like, 'That's my next album.' There's a lot   of stuff they've recorded to. I've worked on a few and I don't even  know  how many [will make the album] because I'm out of the loop. I  kinda pop  up, give Dre music, and then vanish back into my cave again.  That's why  I try not to speak on the album, it's not my place. I don't  know what  he's gonna end up using [on the album], so I don't really  wanna speak on  that. I don't wanna give some information that might  upset anybody,  especially Dre. I'm from the West Coast and I'm one of  Dre’s biggest  fans. I own everything Dre's ever done, even his swap  meet mixtapes. I  have all that stuff. So to actually have his blessing  on Detox and to be working with him on his album is insane to me.”
   
"I learned a really important lesson: Dr. Dre knows what he's doing."
Looks like Dre did have some involvement with this track afterall.
Source and full article, in which he discusses other previous records a produced for, including Eminem, Kayne West, Game, Nas and more.