Updating from custom linux-source-2.6.18-2.6.18.dfsg.1-23etch1 to lastest 2.6.18 kernel by appying the diff file from Etch's linux-image-2.6.18-6-686 ?

[Vianney Lejeune <via.lej@free.fr>]

Hello,

	I have a custom linux-source-2.6.18-2.6.18.dfsg.1-23etch1 (just  
patched for hardware support etc). I'm concerned with the lastest  
CVE-2009-2692 so I would like to update my kernel. As it was a lot of  
work to apply the hardware patches to the initial Etch's linux-source,  
I wonder if it's possible to update my already-patched-for-hardware- 
support-2.6.18-linux-source by applying the diff file from the lastest  
linux-image-2.6.18 package available for Etch ?

Regards,
Vianney