Re: [PATCHv4 RESEND 0/3] syscalls,x86: Add execveat() system call

On Thu, Jun 5, 2014 at 6:40 AM, David Drysdale [off-list ref] wrote:

Resending, adding cc:linux-api.

Also, it may help to add a little more background -- this patch is
needed as a (small) part of implementing Capsicum in the Linux kernel.

Capsicum is a security framework that has been present in FreeBSD since
version 9.0 (Jan 2012), and is based on concepts from object-capability
security [1].

One of the features of Capsicum is capability mode, which locks down
access to global namespaces such as the filesystem hierarchy.  In
capability mode, /proc is thus inaccessible and so fexecve(3) doesn't
work -- hence the need for a kernel-space alternative.

[1] http://www.cl.cam.ac.uk/research/security/capsicum/papers/2010usenix-security-capsicum-website.pdf

Thanks for reposting!

I think it'd be quite helpful to have this available for very tightly
confined sandboxes. And in a larger sense, Capsicum itself is an
interesting way to do programmatic isolation.

-Kees

-- 
Kees Cook
Chrome OS Security