apt-mark hold packages e.g. kernel

 Suppose the kernel version  5.15.0-121 to be held.

1. dpkg -l linux-* | grep ^ii | grep 5.15.0-121
   Will list all the packages installed, 
2. sudo apt-mark hold linux-headers-5.15.0-121 linux-headers-5.15.0-121-generic linux-image-5.15.0-121-generic linux-modules-extra-5.15.0-121-generic
3. apt-mark showhold
   Will list the held packages,e.g
   linux-headers-5.15.0-121
   linux-headers-5.15.0-121-generic
   linux-image-5.15.0-121-generic
   linux-modules-extra-5.15.0-121-generic
   
4. Done.