On Wed, 2022-05-04 at 00:44 +0300, IL Ka wrote: > Linux kernel is backward compatible. Linus calls it "we do not break > userspace". > That means _old_ applications should work on new kernel
There's also the issue of what config options the kernel is built with. I'm sure there's been at least one time in the past where for a new Debian release they've had to enable a kernel feature that the new systemd (or udev?) wanted. But again, a case like that would stop a new Debian working on and old kernel, not the other way around as the OP is intending. I don't expect the Debian kernel maintainers would _remove_ kernel config options needed in a prior release. -- Tixy