From: Derek Schrock <dereks@lifeofadishwasher.com>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: Stefano Brivio <sbrivio@redhat.com>, passt-dev@passt.top
Subject: Re: [PATCH] selinux: Allow access to user_devpts
Date: Tue, 28 May 2024 14:11:37 -0400 [thread overview]
Message-ID: <ZlYeWaAi8tdWHF2v@ircbsd.lifeofadishwasher.com> (raw)
In-Reply-To: <ZlWi-xzaaXhh3STJ@zatzit>
On Tue, May 28, 2024 at 05:25:15AM EDT, David Gibson wrote:
> On Tue, May 28, 2024 at 10:12:56AM +0200, Stefano Brivio wrote:
> > On Tue, 28 May 2024 16:55:55 +1000
> > David Gibson <david@gibson.dropbear.id.au> wrote:
> >
> > > On Sun, May 26, 2024 at 06:28:42PM -0400, Derek Schrock wrote:
> > > > Allow access to user_devpts.
> > > >
> > > > $ pasta --version
> > > > pasta 0^20240510.g7288448-1.fc40.x86_64
> > > > ...
> > > > $ awk '' < /dev/null
> > > > $ pasta --version
> > > > $
> > > >
> > > > While this might be a awk bug it appears pasta should still have access
> > > > to devpts.
> >
> > Derek, thanks for the patch!
> >
> > > It's not clear to me why pasta would need any access to /dev/pts. The
> > > shell that pasta spawns does, of course, but it should already live in
> > > a difference security context.
> >
> > Note that that doesn't happen in a shell pasta spawned: pasta --version
> > doesn't do that.
>
> Oh, good point. I missed what was going on in that example.
>
> > It's just that after that awk comamnd, enabling access to
> > user_tty_device_t doesn't seem to be enough anymore, we need
> > user_devpts_t then. Which is probably something reasonable to enable
> > anyway.
>
> Hmmm.. this still doesn't make sense to me. AFAIK, /dev/pts is about
> managing pseudo-ttys, I see no reason we'd need to do that. Our
> stdout *could* be a pseudo-tty, I suppose. But surely selinux can't
> be requiring us to explicitly allow for any possible stdout/stderr
> target? Especially not one as completely routine as a pseudo-tty -
> that will be the case for anything run in an xterm.
>
> I also can't fathom why running awk would change anything. Could
> there be something bogus in the selinux profile of the original shell
> which allows the awk invocation to change the context somehow?
Don't know if it means anything but stdout still works just not to the
interactive shell with pasta post awk:
$ awk '' < /dev/null
$ pasta --version | wc -l
7
$
This is also reproducible in rocky9 (most likely RHEL9 too). If that's
the case do you want me a ticket with Red Hat?
create a case with Red Hat
next prev parent reply other threads:[~2024-05-28 18:11 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-26 22:28 [PATCH] selinux: Allow access to user_devpts Derek Schrock
2024-05-28 6:55 ` David Gibson
2024-05-28 8:12 ` Stefano Brivio
2024-05-28 9:25 ` David Gibson
2024-05-28 18:11 ` Derek Schrock [this message]
2024-05-29 13:16 ` Stefano Brivio
2024-06-05 16:23 ` Stefano Brivio
2024-06-07 18:48 ` Stefano Brivio
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