> Could they have submitted patches to fix the problems based on same tooling or was that not possible (I am not close to kernel development flow)?
Depends on what you mean: they knew exactly what they were patching, so they could easily have submitted inverse patches. On the other hand, the obverse research problem (patching existing UAFs rather than inserting new ones) is currently unsolved in the general case.
Could they have submitted patches to fix the problems based on same tooling or was that not possible (I am not close to kernel development flow)?