systemd: fix CVE-2018-15688

Backport patch to fix the following CVE.

CVE: CVE-2018-15688

(From OE-Core rev: d490839e881f3ff30a4bde8137cb04cb0fd37acd)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

Cherry-picked from thud 13591d7224393dc0ae529a03cdf74aceb3540ce9

Signed-off-by: George McCollister <george.mccollister@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/systemd/systemd/0001-dhcp6-make-sure-we-have-enough-space-for-the-DHCP6-o.patch

@@ -0,0 +1,39 @@
+From a2622b8398ba026faf481f5eddeb53231d9de4a7 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 a vulnerability originally discovered by Felix Wilhelm from
+Google.
+
+CVE-2018-15688
+LP: #1795921
+https://bugzilla.redhat.com/show_bug.cgi?id=1639067
+
+(cherry picked from commit 4dac5eaba4e419b29c97da38a8b1f82336c2c892)
+
+CVE: CVE-2018-15688
+Upstream-Status: Backport
+
+Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
+---
+ 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 c4b402b..dcbaad0 100644
+--- a/src/libsystemd-network/dhcp6-option.c
++++ b/src/libsystemd-network/dhcp6-option.c
+@@ -103,7 +103,7 @@ 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;
+-- 
+2.7.4
+

meta/recipes-core/systemd/systemd_237.bb

@@ -56,6 +56,7 @@ SRC_URI += "file://touchscreen.rules \
            file://0035-Define-glibc-compatible-basename-for-non-glibc-syste.patch \
            file://0001-core-when-deserializing-state-always-use-read_line-L.patch \
            file://0001-chown-recursive-let-s-rework-the-recursive-logic-to-.patch \
+           file://0001-dhcp6-make-sure-we-have-enough-space-for-the-DHCP6-o.patch \
            "
 SRC_URI_append_qemuall = " file://0001-core-device.c-Change-the-default-device-timeout-to-2.patch"