From 94cf2854a93575db75aed221ec4ecb24a609a85b Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Wed, 18 Sep 2019 14:05:18 +0100
Subject: [PATCH] Fix panic where slice goes out of bounds because iface.Read
 returns less than zero (which might happen when the TUN/TAP interface is
 closed)

---
 src/tuntap/iface.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tuntap/iface.go b/src/tuntap/iface.go
index 92ba36ab..753a8d02 100644
--- a/src/tuntap/iface.go
+++ b/src/tuntap/iface.go
@@ -111,7 +111,7 @@ func (r *tunReader) _read() {
 	recvd := util.ResizeBytes(util.GetBytes(), 65535+tun_ETHER_HEADER_LENGTH)
 	// Wait for a packet to be delivered to us through the TUN/TAP adapter
 	n, err := r.tun.iface.Read(recvd)
-	if n == 0 {
+	if n <= 0 {
 		util.PutBytes(recvd)
 	} else {
 		r.tun.handlePacketFrom(r, recvd[:n], err)