Re: [PATCH net] vxlan: reset the remote's dst cache when snooping moves a MAC

[CMGS <ilskdw@gmail.com>]

> [Severity: High]
> Should this branch also update rdst->remote_ifindex and clear
> rdst->offloaded, as vxlan_fdb_replace() does?

Yes. The early return compares remote_ifindex and vxlan_xmit_one()
uses it as the oif, so leaving it stale can refill the cache with a
route for the previous interface, and with this patch every later
packet from that peer would reset the cache. v2 will set
remote_ifindex and clear offloaded in the same branch, as
vxlan_fdb_replace() does.

> [Severity: Low]
> Can a concurrent transmitter still cache a route to the previous remote
> after this reset?

The window exists, but it is the same one vxlan_fdb_replace() and the
other dst_cache users that reset after a parameter change have. Closing
it needs a change to dst_cache invalidation, which is out of scope for
this fix.

pw-bot: cr