[PATCH v6] lsm: Add LSM hook security_unix_find

[Paul Moore]

On Thu, Feb 19, 2026 at 3:26 PM Günther Noack <gnoack3000 at gmail.com> wrote:
> On Thu, Feb 19, 2026 at 03:04:59PM -0500, Justin Suess wrote:
> > Add a LSM hook security_unix_find.
> >
> > This hook is called to check the path of a named unix socket before a
> > connection is initiated. The peer socket may be inspected as well.
> >
> > Why existing hooks are unsuitable:
> >
> > Existing socket hooks, security_unix_stream_connect(),
> > security_unix_may_send(), and security_socket_connect() don't provide
> > TOCTOU-free / namespace independent access to the paths of sockets.
> >
> > (1) We cannot resolve the path from the struct sockaddr in existing hooks.
> > This requires another path lookup. A change in the path between the
> > two lookups will cause a TOCTOU bug.
> >
> > (2) We cannot use the struct path from the listening socket, because it
> > may be bound to a path in a different namespace than the caller,
> > resulting in a path that cannot be referenced at policy creation time.
> >
> > Cc: Günther Noack <gnoack3000 at gmail.com>
> > Cc: Tingmao Wang <m at maowtm.org>
> > Signed-off-by: Justin Suess <utilityemal77 at gmail.com>
> > ---
> >  include/linux/lsm_hook_defs.h |  5 +++++
> >  include/linux/security.h      | 11 +++++++++++
> >  net/unix/af_unix.c            | 13 ++++++++++---
> >  security/security.c           | 20 ++++++++++++++++++++
> >  4 files changed, 46 insertions(+), 3 deletions(-)

...

> Reviewed-by: Günther Noack <gnoack3000 at gmail.com>
>
> Thank you, this looks good. I'll include it in the next version of the
> Unix connect patch set again.

I'm looking for this patchset to review/ACK the new hook in context,
but I'm not seeing it in my inbox or lore.  Did I simply miss the
patchset or is it still a work in progress?  No worries if it hasn't
been posted yet, I just wanted to make sure I wasn't holding this up
any more than I already may have :)

-- 
paul-moore.com