On Thu, 25 Jun 2026 06:59:37 +0000 Eric Dumazet wrote:

These flags can be modified concurrently from different contexts:
- RTNL-locked paths (like add_port/del_port) write to need_sync and
  work_pending.

These should hold utn->lock. Not sure why udp_tunnel_nic_lock() 
is locking in the callers rather than directly in
__udp_tunnel_nic_add_port() / __udp_tunnel_nic_del_port()..

- The RTNL-less reset path (reset_ntf, used by netdevsim) writes to
  need_sync and need_replay under utn->lock.

I'd rather add asserts to confirm utn lock is held everywhere.
This code is hard enough to follow as is, without having to
think through potential concurrent accesses.