Re: [RFC PATCH v19 2/5] security: Add new SHOULD_EXEC_CHECK and SHOULD_EXEC_RESTRICT securebits

Mickaël Salaün <[email protected]> Sat, 6 Jul 2024 16:56:53 +0200
Newsgroups com.openwall.lists.kernel-hardening,org.kernel.vger.linux-api,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-integrity,org.kernel.vger.linux-kernel,org.kernel.vger.linux-security-module
Message-ID <[email protected]>
On Sat, Jul 06, 2024 at 01:22:06AM +0300, Jarkko Sakkinen wrote:
> On Sat Jul 6, 2024 at 12:44 AM EEST, Kees Cook wrote:
> > > As explained in the UAPI comments, all parent processes need to be
> > > trusted.  This meeans that their code is trusted, their seccomp filters
> > > are trusted, and that they are patched, if needed, to check file
> > > executability.
> >
> > But we have launchers that apply arbitrary seccomp policy, e.g. minijail
> > on Chrome OS, or even systemd on regular distros. In theory, this should
> > be handled via other ACLs.
> 
> Or a regular web browser? AFAIK seccomp filtering was the tool to make
> secure browser tabs in the first place.

Yes, and that't OK.  Web browsers embedded their own seccomp filters and
they are then as trusted as the browser code.