Install newer kernels in Debian stable

Prerequisites

Install Debian, all commands below run as root:

sudo su -

Enable backports

cat <<EOT >>/etc/apt/sources.list

deb http://deb.debian.org/debian/ stretch-backports main contrib non-free
deb-src http://deb.debian.org/debian/ stretch-backports main contrib non-free
EOT

Upgrade some packages

It's unclear why we need this or whether we need it at all

sudo apt-get -t stretch-backports upgrade

Search for new kernel

apt search linux-image

Install new kernel

apt-get -t stretch-backports install linux-image-4.19.0-0.bpo.2-amd64 linux-headers-4.19.0-0.bpo.2-amd64 firmware-linux-free

Reboot

reboot

aram@debian:~$ uname -a
Linux debian 4.19.0-0.bpo.2-amd64 #1 SMP Debian 4.19.16-1~bpo9+1 (2019-02-07) x86_64 GNU/Linux
aram@debian:~$