Re: Buffer overflow?

[Richard Coleman <richardcoleman@xxxxxxxxxxxxxx>]

Matthew Dillon wrote:
>     Well, I am neutral on the topic.  I generally consider these
>     sorts of security fixes as masking the problem rather then
>     fixing it.  What I would like to see (and another reason for
>     doing the VFS layer and syscall emulation) is a way to limit
>     a program's ability to manipulate its environment to just
>     the files that we say it can access/modify.  Also, the ability
>     to wrap a program with another program which takes control of
>     its syscalls (another reason for doing syscall messaging).
>
>     As an extreme example take a program like 'ls'.  There is
>     no reason under the sun for the system to allow a program
>     like 'ls' to exec(), yet nearly all UNIX systems do allow
>     this.  You get the drift of where I'm going...
>
>     The key is to make this all doable in userland.  Restricting
>     these sorts of features to the kernel greatly reduces the
>     number of people who can potentially develop code up 
>     related projects.

Aren't these exactly the reason that people added Mandatory Access 
Controls (MAC)?  It sounds like you want a user space version of MAC's.

Also "systrace" does something similar.  I know that OpenBSD has this.

Richard Coleman
richardcoleman@xxxxxxxxxxxxxx