Computer Forums - Compiling kernel 2.6.14.6 with grsec Centos 4.2

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Compiling kernel 2.6.14.6 with grsec Centos 4.2

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.

Code:

yum install gcc

ncurses-devel package is needed while compiling kernel

Code:

yum install ncurses-devel

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

Code:

CD /usr/local/src

down Load kernel 2.6.14.6

Code:

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

untar the kernel

Code:

tar -zxf linux-2.6.14.6.tar.gz

download the grsecurity patch

Code:

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

patch the kernel

Code:

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

cd to the kernel

Code:

cd linux-2.6.14.6

clean your kernel source configuration etc

Code:

make clean && make mrproper

use your current configuration to configure your new kernel

Code:

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

go into into the menu

Code:

make menuconfig

go to the grsecsecurity option select medium

now to actually compile the kernel

Code:

make bzImage

Code:

make modules

Code:

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.

Code:

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.

Code:

/boot/grub/grub.conf

add the following line

Code:

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.

kernel is a security thing, right? what does it actually do?

The kernel is the brain of the OS. With out it, Linux wouldn't run. Adding grsec to the kernel helps prevent the kernel from being hacked.

I'm going to give this a go...

[QUOTE=Soulwatcher]
you need gcc to compile kernel.
[/QUTOE]
Already have it for some Perl modules I installed...

Quote: