From 8b962f23d194ae0999c296a5a3250d0e77dadf57 Mon Sep 17 00:00:00 2001
From: Fran Bull <fran@tailscale.com>
Date: Tue, 17 Sep 2024 09:23:33 -0700
Subject: [PATCH] cmd/natc: fix nil pointer

Fixes #13495

Signed-off-by: Fran Bull <fran@tailscale.com>
---
 cmd/natc/natc.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/cmd/natc/natc.go b/cmd/natc/natc.go
index df458755c..d94523c6e 100644
--- a/cmd/natc/natc.go
+++ b/cmd/natc/natc.go
@@ -456,6 +456,11 @@ func (c *connector) ignoreDestination(dstAddrs []netip.Addr) bool {
 }
 
 func proxyTCPConn(c net.Conn, dest string) {
+	if c.RemoteAddr() == nil {
+		log.Printf("proxyTCPConn: nil RemoteAddr")
+		c.Close()
+		return
+	}
 	addrPortStr := c.LocalAddr().String()
 	_, port, err := net.SplitHostPort(addrPortStr)
 	if err != nil {