Re: [PATCH v2 3/6] landlock: Bump ABI for LANDLOCK_SCOPE_SYSV_MSG_QUEUE

[Justin Suess <utilityemal77@gmail.com>]

On Fri, Aug 21, 2026 at 02:38:15PM +0200, Günther Noack wrote:
> On Mon, Jul 27, 2026 at 07:08:30PM -0400, Justin Suess wrote:
> > Bump the ABI version for Landlock SysV message queue scoping.
> > 
> > Signed-off-by: Justin Suess <utilityemal77@gmail.com>
> 
> The ABI bump is normally put into the same commit as the
> implementation for easier backporting. Otherwise, looks good.
I'll squash them.

>
Thanks,

I did wonder about if we need to use the landlock_object here?

I'm pretty sure SysV message queues stay open after process exit,
which could cause the domain to be pinned by landlock_cred_security,
if programs are lazy and don't close them.

So it probably needs to be a weak reference. 

But it's unclear what should be the behavior there when the domain
is dropped:

1. Should it become inaccessible and belong to *nobody's* domain?

(i.e when owning domain is dropped, the queue belongs to no domain and is inaccessible to
all LANDLOCK_SCOPE_SYSV_MSG_QUEUE scoped domains)

2. Should it be moved to the parent's domain?

(i.e when owning domain is dropped, the parent domain is the new scope,
and then it's parent, so on and so forth, more complicated, but more correct)

3. Or be kept as is.

(i.e Allow an open sysv message queue to pin a domain
for it's lifetime)

Either way this almost certainly needs to be rebased since it's been
a little bit and there were significant refactorings of the domain and
ruleset structures since the tracepoints series.

Justin

> –Günther