From b224c946835e9523bb8cd125718027f68843d30e Mon Sep 17 00:00:00 2001
From: Nick Khyl <nickk@tailscale.com>
Date: Wed, 23 Apr 2025 09:35:14 -0500
Subject: [PATCH] net/portmapper: fix nil pointer dereference in
 Client.createMapping

The EventBus in net/portmapper.Config is still optional and Client.updates can be nil.

Updates #15772

Signed-off-by: Nick Khyl <nickk@tailscale.com>
---
 net/portmapper/portmapper.go | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/net/portmapper/portmapper.go b/net/portmapper/portmapper.go
index f95d6503a..59f88e966 100644
--- a/net/portmapper/portmapper.go
+++ b/net/portmapper/portmapper.go
@@ -508,11 +508,13 @@ func (c *Client) createMapping() {
 		}
 		return
 	}
-	c.updates.Publish(Mapping{
-		External:  mapping.External(),
-		Type:      mapping.MappingType(),
-		GoodUntil: mapping.GoodUntil(),
-	})
+	if c.updates != nil {
+		c.updates.Publish(Mapping{
+			External:  mapping.External(),
+			Type:      mapping.MappingType(),
+			GoodUntil: mapping.GoodUntil(),
+		})
+	}
 	if c.onChange != nil {
 		go c.onChange()
 	}