Miss Alabama Madeline Mitchell -- Boobie Pics Being Shopped

Beauty queens and nudie pics go together like Farrah Abraham and porn ... the latest example, a photo of Miss Alabama flashing her giant knockers -- which is being shopped to the highest bidder.

Our sources tell us ... someone is hocking a pic of Madeline Mitchell, who repped Alabama in the 2011 Miss USA pageant. At the time she was known as the hot chick who was in a horrific car crash.

As for the pic -- we've seen it. It's a selfie and she's topless -- showing off her HUGE southern melons -- smiling from ear to ear. Her hoo ha is covered.

It's unclear how the seller got the pic ...or if there have been any offers.