Likely its a leak around the front or rear breather hose off the airbox. You either end up with oil mist spray on the rear cylinder head or all around the front cylinder.
Sometimes the rear rubber hose splits or the front connector under the airbox isnt seated correctly, may need a new O ring. Quite a common problem. Ive replaced the rear hose on my bike and re seated the front with some heat resistant sealant to cure it.
If you follow the workshop manual instructions to remove and re-fit the airbox including lower part you will see the offending parts or search "breather hose leak" for many threads/pics/solutions.