From 625b22a8d7bece655216b926f1b4ce35e14ccb07 Mon Sep 17 00:00:00 2001
From: Simon Zolin <s.zolin@adguard.com>
Date: Fri, 23 Aug 2019 14:44:23 +0300
Subject: [PATCH] * dhcp: validate range_start/range_end values

---
 dhcpd/dhcpd.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/dhcpd/dhcpd.go b/dhcpd/dhcpd.go
index 3d3d0b33..a1a54b2e 100644
--- a/dhcpd/dhcpd.go
+++ b/dhcpd/dhcpd.go
@@ -129,6 +129,9 @@ func (s *Server) setConfig(config ServerConfig) error {
 	if err != nil {
 		return wrapErrPrint(err, "Failed to parse range end address %s", config.RangeEnd)
 	}
+	if dhcp4.IPRange(s.leaseStart, s.leaseStop) <= 0 {
+		return wrapErrPrint(err, "DHCP: Incorrect range_start/range_end values")
+	}
 
 	subnet, err := parseIPv4(config.SubnetMask)
 	if err != nil || !isValidSubnetMask(subnet) {