On Sun, Jan 11, 2026 at 10:23:16PM +0100, Günther Noack wrote:

Hello Matthieu!

On Fri, Dec 12, 2025 at 05:36:56PM +0100, Matthieu Buffet wrote:

quoted

Here is v3 of UDP support for Landlock. My apologies for the delay, I've
had to deal with unrelated problems. All feedback from v1/v2 should be
merged, thanks again for taking the time to review them.

Good to see the patch again. :)

Apologies for review delay as well.  There are many Landlock reviews
in flight at the moment, it might take some time to catch up with all
of them.

FYI: In [1], I have been sending a patch for controlling UNIX socket
lookup, which is restricting connect() and sendmsg() operations for
UNIX domain sockets of types SOCK_STREAM, SOCK_DGRAM and
SOCK_SEQPACKET.  I am bringing it up because it feels that the
semantics for the UDP and UNIX datagram access rights hook in similar
places and therefore should work similarly?

Thanks for bringing this up.

In the current UNIX socket patch set (v2), there is only one Landlock
access right which controls both connect() and sendmsg() when they are
done on a UNIX datagram socket.  This feels natural to be, because you
can reach the same recipient address whether that is done with
connect() or with sendmsg()...?

(Was there a previous discussion where it was decided that these
should be two different access rights for UDP sockets and UNIX dgram
sockets?)

The rationale for these three access rights (connect, bind, and sendto)
is in the related commit message and it was discussed here:
https://lore.kernel.org/all/3631edfd-7f41-4ff1-9f30-20dcaa17b726@buffet.re/ (local)

Access rights for UNIX sockets can be simpler because we always know the
peer process, which is not the case for IP requests.  For the later,
being able to filter on the socket type can help.

[1] https://lore.kernel.org/all/20260101134102.25938-1-gnoack3000@gmail.com/ (local)

Thanks,
–Günther