I run Fedora 25 on my laptop,on a dedicated partition,other OSs on other partitions,and a
strange thing happens:
On my Fedora 25 /boot/ directory I only have kernels 4.2.3 and 4.9.12 the most recent(and
a rescue kernel not numbered).However Grub2 shows 3 entries for kernel
4.8.6,4.2.3,4.9.12.I tried to get rid of 4.8.6 but rpm -qi kernel or rpm -qi kernel-core
only show kernels 4.2.3 and 4.9.12.The same using dnf.The kernel 4.8.6 does not appear on
/boot directory nor with rpm,dnf or anything I tried.This is really a stealth kernel and I
do not know where it stands,in the first place,to get rid of it.
When I choose the corresponding GRUB2 menu entry this kernel 4.8.6 shows that it is
real.With uname --all it appears as the active kernel.