Compiling kernel 2.6.14.6 with grsec Centos 4.2

[Soulwatcher]

Warning use this guide at your own risk! It works on my server it doesn't mean it will work on yours.

you need gcc to compile kernel.

yum install gcc

ncurses-devel package is needed while compiling kernel

yum install ncurses-devel

I like to build my kernels in /usr/local/src

CD /usr/local/src

down Load kernel 2.6.14.6

wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.14.6.tar.gz

untar the kernel

tar -zxf linux-2.6.14.6.tar.gz

download the grsecurity patch

wget http://grsecurity.net/grsecurity-2.1.8-2.6.14.6-200601211647.patch.gz

patch the kernel

gunzip < grsecurity-2.1.8-2.6.14.6-200601211647.patch.gz | patch -p0

cd to the kernel

cd linux-2.6.14.6

clean your kernel source configuration etc

make clean && make mrproper

use your current configuration to configure your new kernel

cp /boot/config-`uname -r` .config

go into into the menu

make menuconfig

go to the grsecsecurity option select medium

now to actually compile the kernel

make bzImage

make modules

make modules_install

make sure there are *NO* errors after this! If you do get errors the below is not going to work.

copy the new files into your /boot directory.

cp .config /boot/config-2.6.14.6-grsec
cp arch/i386/boot/bzImage /boot/vmlinuz-2.6.14.6-grsec
cp System.map /boot/System.map-2.6.14.6-grsec
mkinitrd /boot/initrd-2.6.14.6-grsec.img 2.6.14.6-grsec

using your favorite editor edit the grub config file.

/boot/grub/grub.conf

add the following line

title CentOS (2.6.14.6-grsec)
	root (hd0,0)
	kernel /vmlinuz-2.6.14.6-grsec ro root=LABEL=/
	initrd /initrd-2.6.14.6-grsec.img

Edit: make sure you check the root=LABEL=/ in grub as it may be different than mine. Make sure you use your servers own root=LABEL=/

thats it your done save and exit.