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

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Date:   Tue, 23 Feb 2021 19:02:25 -0500
From:   Paul Moore <paul@...l-moore.com>
To:     Tyler Hicks <tyhicks@...ux.microsoft.com>
Cc:     Stephen Smalley <stephen.smalley.work@...il.com>,
        Ondrej Mosnacek <omosnace@...hat.com>, selinux@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [BUG] Race between policy reload sidtab conversion and live conversion

On Tue, Feb 23, 2021 at 5:36 PM Tyler Hicks <tyhicks@...ux.microsoft.com> 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@redhat.com/
>
> 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