Dear Jakub,

Following your instruction, we read the documentation at https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html.
We found that the stable documentation normally requires an upstream commit before inclusion in stable, but here an upstream commit 
cannot exist because the subsystem was removed. Could you please confirm that this can proceed as a stable-only fix for the affected LTS branches?

Thanks for your guidance on the correct path here.

Yours Sincerely,
Yizhou Zhao