Re: [PATCHv3 2/3] kernel: add support for live patching

[Thomas Gleixner <tglx@linutronix.de>]

On Thu, 20 Nov 2014, Seth Jennings wrote:
> This commit introduces code for the live patching core.  It implements
> an ftrace-based mechanism and kernel interface for doing live patching
> of kernel and kernel module functions.
> 
> It represents the greatest common functionality set between kpatch and
> kgraft and can accept patches built using either method.
> 
> This first version does not implement any consistency mechanism that
> ensures that old and new code do not run together.  In practice, ~90% of
> CVEs are safe to apply in this way, since they simply add a conditional
> check.  However, any function change that can not execute safely with
> the old version of the function can _not_ be safely applied in this
> version.

To be honest this sounds frightening.

How is determined whether a change can be applied w/o a consistency
mechanism or not?

Thanks,

	tglx