From 64383aae90fe4a1c1b5c4e4098e924c0e2623471 Mon Sep 17 00:00:00 2001

From: Jan Synacek <jsynacek@redhat.com>

Date: Thu, 1 Nov 2018 13:11:11 +0100

Subject: [PATCH] dhcp6: make sure we have enough space for the DHCP6 option

 header

Fixes a vulnerability originally discovered by Felix Wilhelm from Google.

(cherry picked from commit 01ca2053bbea09f35b958c8cc7631e15469acb79)

Resolves: CVE-2018-15688

---

 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 ea863f45e4..649bbea304 100644

--- a/src/libsystemd-network/dhcp6-option.c

+++ b/src/libsystemd-network/dhcp6-option.c

@@ -100,7 +100,7 @@ int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, DHCP6IA *ia) {

                 return -EINVAL;

         }

-        if (*buflen < len)

+        if (*buflen < offsetof(DHCP6Option, data) + len)

                 return -ENOBUFS;

         ia_hdr = *buf;