2026-03-12, 17:47:45 +0100, Paolo Abeni wrote:

On 3/12/26 4:58 PM, Sabrina Dubroca wrote:

quoted

2026-03-12, 14:34:44 +0000, Hangbin Liu wrote:

quoted

On Thu, Mar 12, 2026 at 12:13:52PM +0100, Sabrina Dubroca wrote:

quoted

Proper fix (so that the notification we're sending during
upper_dev_link has full linkinfo) would be to move
netdev_upper_dev_link() to after macsec_changelink_common() and fix up
the error handling. I don't see anything in macsec_add_dev or
macsec_changelink_common that needs the device to be linked. But

If we move the netdev_upper_dev_link() after macsec_changelink_common(),
we will not goto nla_put_failure via default, right?

Yes.

quoted

quoted

anyway it doesn't make sense for macsec_fill_info to return -EMSGSIZE
on invalid data, so the "bandaid" should be included as well.

Should this be part of this series (either just the "bandaid" or the
"proper fix"+bandaid), since we never saw a problem before?

Since macsec need the "bandaid" fix either way. How about you post the
"bandaid" fix to net. And I include the "proper fix" in this series for
net-next?

But I don't think it's needed in net. Am I missing a codepath (before
your series) where macsec_fill_info could be called for the new device
before macsec_newlink returns? If not, it doesn't really qualify as a
fix, that's why I was asking Paolo.

FWIW, I don't see a codepath calling into rtmsg_ifinfo_build_skb()
before device initialization, so I would be fine targeting net-next with
the EMSGSIZE-related change.

Side note, it looks like that the WARN() in the rnnetlink code here
helped identifying a real problem and correctly returning 0 when the
key_len is not yet initialized will silence it forever, what about
preserving a warning for this kind of race? something alike:

Right, I was thinking about putting a DEBUG_NET_WARN_ON_ONCE there.

-- 
Sabrina