Re: [PATCH net 1/1] net: l2tp: ignore multicast notification errors in netlink commands

On Mon, Aug 17, 2026 at 05:21:09PM +0000, Zihan Xi wrote:

l2tp_nl_cmd_tunnel_create(), l2tp_nl_cmd_session_create(), and
l2tp_nl_cmd_session_modify() update live state before sending their
multicast notifications. A notification helper can fail while allocating
or encoding the message, or while multicasting it. Returning any such
best-effort notification error after the state change makes a successful
command look like a failure and can cause retries to accumulate live
objects.

Is this a theoretical problem, or something that has been observed?

Keep sending notifications for listener visibility, but do not let their
best-effort status overwrite the command result. The explicit (void) casts
make this intentional for all notification helper failures.

I don't think the (void) cast is in keeping with the existing code
in this file.

Fixes: 33f72e6f0c67 ("l2tp : multicast notification to the registered listeners")
Cc: stable@vger.kernel.org
Reported-by: Vega <redacted>
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zihan Xi <redacted>

I am wondering if you considered extending this patch to
also cover l2tp_nl_cmd_tunnel_modify().

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