From 4020561368ab697fbef2c5d6a3585b7647298fd3 Mon Sep 17 00:00:00 2001
From: Franco Fichtner <franco@opnsense.org>
Date: Mon, 26 Jan 2026 11:05:35 +0100
Subject: [PATCH] isc-dhcp: check if device we try to configure exists in the
 system

PR: https://github.com/opnsense/plugins/issues/5169
---
 net/isc-dhcp/Makefile                            | 2 +-
 net/isc-dhcp/pkg-descr                           | 1 +
 net/isc-dhcp/src/etc/inc/plugins.inc.d/dhcpd.inc | 4 ++++
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/isc-dhcp/Makefile b/net/isc-dhcp/Makefile
index 93478a0aa..970944acb 100644
--- a/net/isc-dhcp/Makefile
+++ b/net/isc-dhcp/Makefile
@@ -1,6 +1,6 @@
 PLUGIN_NAME=		isc-dhcp
 PLUGIN_VERSION=		1.0
-PLUGIN_REVISION=	2
+PLUGIN_REVISION=	3
 PLUGIN_COMMENT=		ISC DHCPv4/v6 server
 PLUGIN_DEPENDS=		isc-dhcp44-server
 PLUGIN_MAINTAINER=	franco@opnsense.org
diff --git a/net/isc-dhcp/pkg-descr b/net/isc-dhcp/pkg-descr
index fe0e35dae..36f446184 100644
--- a/net/isc-dhcp/pkg-descr
+++ b/net/isc-dhcp/pkg-descr
@@ -14,4 +14,5 @@ Plugin Changelog
 * First release resembling the core state of 25.7.11
 * Minor changes due to "radvd" extraction out of DHCPv6 configuration
 * Minor changes regarding "track6" and "idassoc6" mode handling
+* Safeguard dhcpd_staticarp() from nonexistent interface configuration
 * Added DHCPv6 static mappings export
diff --git a/net/isc-dhcp/src/etc/inc/plugins.inc.d/dhcpd.inc b/net/isc-dhcp/src/etc/inc/plugins.inc.d/dhcpd.inc
index aaea6aff3..df22829e0 100644
--- a/net/isc-dhcp/src/etc/inc/plugins.inc.d/dhcpd.inc
+++ b/net/isc-dhcp/src/etc/inc/plugins.inc.d/dhcpd.inc
@@ -1310,6 +1310,10 @@ function dhcpd_staticarp($interface, $ifconfig_details)
 
     $device = $ifcfg['if'];
 
+    if (empty($ifconfig_details[$device])) {
+        return;
+    }
+
     $have = in_array('staticarp', $ifconfig_details[$device]['flags']);
     $want = isset($config['dhcpd'][$interface]['staticarp']);