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

[Zihan Xi]

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.

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.

Fixes: 33f72e6f0c67 ("l2tp : multicast notification to the registered listeners")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Vega <vega@xxxxxxxxxx>
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zihan Xi <zihanx@xxxxxxxxxx>
---
 net/l2tp/l2tp_netlink.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index 59457c0c1..21160284f 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -248,8 +248,8 @@ static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info
 		kfree(tunnel);
 		goto out;
 	}
-	ret = l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel,
-				 L2TP_CMD_TUNNEL_CREATE);
+	(void)l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel,
+			      L2TP_CMD_TUNNEL_CREATE);
 	l2tp_tunnel_put(tunnel);
 
 out:
@@ -645,8 +645,8 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
 		session = l2tp_session_get(net, tunnel->sock, tunnel->version,
 					   tunnel_id, session_id);
 		if (session) {
-			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
-						  L2TP_CMD_SESSION_CREATE);
+			(void)l2tp_session_notify(&l2tp_nl_family, info, session,
+					   L2TP_CMD_SESSION_CREATE);
 			l2tp_session_put(session);
 		}
 	}
@@ -710,8 +710,8 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf
 	if (info->attrs[L2TP_ATTR_RECV_TIMEOUT])
 		session->reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]);
 
-	ret = l2tp_session_notify(&l2tp_nl_family, info,
-				  session, L2TP_CMD_SESSION_MODIFY);
+	(void)l2tp_session_notify(&l2tp_nl_family, info,
+				   session, L2TP_CMD_SESSION_MODIFY);
 
 	l2tp_session_put(session);
 
-- 
2.43.0