Re: [PATCH] ptrace: allow restriction of ptrace scope

James Morris
2010-06-17T13:46:37Z

On Wed, 16 Jun 2010, Kees Cook wrote:

[Note: it would be useful to cc: the LSM list on security discussions]

> Certainly. PTRACE can already be confined by SELinux and AppArmor. I'm
> looking for a general approach that doesn't require a system builder to
> create MAC policies for unknown software. I want to define a common core
> behavior.
>
> > And even if you don't care about using the same security stuff the rest
> > of the world is using to solve the problem this like the other half baked
> > stuff you posted for links belongs as a security module.
>
> The LSM isn't stackable, so I can't put it there and choose this and
> SELinux (for the case of software-without-a-policy).

SELinux already supports a global switch for ptrace via the allow_ptrace
boolean. You don't need to write any policy, just set it to 0.

Global behavior can be further customized and refined (e.g. create a
generic policy module for apps without an existing policy, which allows
everything except things like ptrace and dangerous symlinks).

SELinux users would not need the other LSM, and stacking is thus not
required.

- James
--
James Morris
<jmorris@namei.org>