Re: [BUG] Race between policy reload sidtab conversion and live conversion

From: Paul Moore
Date: Tue Feb 23 2021 - 19:45:39 EST


On Tue, Feb 23, 2021 at 5:36 PM Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx> wrote:
> On 2021-02-23 15:50:56, Tyler Hicks wrote:
> > On 2021-02-23 15:43:48, Tyler Hicks wrote:
> > > I'm seeing a race during policy load while the "regular" sidtab
> > > conversion is happening and a live conversion starts to take place in
> > > sidtab_context_to_sid().
> > >
> > > We have an initial policy that's loaded by systemd ~0.6s into boot and
> > > then another policy gets loaded ~2-3s into boot. That second policy load
> > > is what hits the race condition situation because the sidtab is only
> > > partially populated and there's a decent amount of filesystem operations
> > > happening, at the same time, which are triggering live conversions.
>
> Hmm, perhaps this is the same problem that's fixed by Ondrej's proposed
> change here:
>
> https://lore.kernel.org/selinux/20210212185930.130477-3-omosnace@xxxxxxxxxx/
>
> I'll put these changes through a validation run (the only place that I
> can seem to reproduce this crash) and see how it looks.

Thanks, please let us know what you find out.

--
paul moore
www.paul-moore.com