Re: [PATCH v3] killswitch: add per-function short-circuit mitigation primitive

[Sasha Levin]

On Tue, May 19, 2026 at 03:00:15PM -0700, Song Liu wrote:
> On Tue, May 19, 2026 at 12:57 PM Sasha Levin <sashal@xxxxxxxxxx> wrote:
> [...]
> > >Fully agree with Song here that there is no clear boundary, and that the
> > >killswitch could lead to arbitrary, hard to debug breakage if applied to
> > >the wrong function.. introducing worse bugs than the one being mitigated
> > >or even /short-circuit LSM enforcement/ (engage security_file_open 0,
> > >engage cap_capable 0, engage apparmor_* etc).
> >
> > This is similar to livepatch, right? Do we need guardrails there too?
>
> livepatch has the same guardrails as other kernel modules:
> CONFIG_MODULE_SIG, CONFIG_MODULE_SIG_FORCE, etc.

Which the user can choose to enable or disable. Livepatches will work just fine
with CONFIG_MODULE_SIG=n, right?

With the whitelist approach, the user has no choice but to accept it.

Would it make sense to allow disabling the whitelist via a kernel config or
some runtime flag?

--
Thanks,
Sasha