Re: Is this the ultimate stack-smash fix?

[ebiederm@xmission.com (Eric W. Biederman)]

Jeremy Jackson <jeremy.jackson@sympatico.ca> writes:

> Greetings.  This is my first post on linux-kernel, I hope this is
> appropriate.
> 
> The recent CERT IN-2001-01 's massive repercussions and CA-2001-02's
> re-releasing
> old material in an attempt to coerce admins to update their OS, has led
> me to think about
> buffer overrun exploits.   I have gained a new appreciation after being
> rooted twice this month.
> 
> I believe there is a solution that can be implemented in the kernel
> (Linux and probably most Unix)
> that can prevent this type of exploit, has no effect on userspace code,
> and is minimally obtrusive
> for the kernel.

There is another much more effective solution in the works.  The C
standard allows bounds checking of arrays.  So it is quite possible
for the compiler itself to check this in a combination of run-time and
compile-time checks.   I haven't followed up but not too long ago
there was an effort to add this as an option to gcc.  If you really
want this fixed that is the direction to go.  Then buffer overflow
exploits become virtually impossible.

Eric