From 49653743f69658aeeebdb14faf1ab158f1f2cb20 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 19 Oct 2018 12:12:33 +0200
Subject: [PATCH] dhcp6: make sure we have enough space for the DHCP6 option
 header

Fixes CVE-2018-15688:
https://security-tracker.debian.org/tracker/CVE-2018-15688

Patch downloaded from upstream commit:
https://github.com/systemd/systemd/commit/49653743f69658aeeebdb14faf1ab158f1f2cb20

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
---
 src/libsystemd-network/dhcp6-option.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c
index cbd4bc7a2a3..2806415100c 100644
--- a/src/libsystemd-network/dhcp6-option.c
+++ b/src/libsystemd-network/dhcp6-option.c
@@ -106,7 +106,7 @@ int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, const DHCP6IA *ia) {
                 return -EINVAL;
         }
 
-        if (*buflen < len)
+        if (*buflen < offsetof(DHCP6Option, data) + len)
                 return -ENOBUFS;
 
         ia_hdr = *buf;