avahi: fix CVE-2017-6519

Backport patch to fix CVE-2017-6519.

CVE: CVE-2017-6519

(From OE-Core rev: cf787f8eab1c85dbafb5e74bf12eb4ddb5c5cbf7)

Signed-off-by: Kai Kang <kai.kang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 51 insertions, 1 deletions

diff --git a/meta/recipes-connectivity/avahi/avahi.inc b/meta/recipes-connectivity/avahi/avahi.inc
index 11846849f0..8339e451f5 100644
--- a/meta/recipes-connectivity/avahi/avahi.inc
+++ b/meta/recipes-connectivity/avahi/avahi.inc
@@ -19,7 +19,9 @@ LIC_FILES_CHKSUM = "file://LICENSE;md5=2d5025d4aa3495befef8f17206a5b0a1 \
                     file://avahi-daemon/main.c;endline=21;md5=9ee77368c5407af77caaef1b07285969 \
                     file://avahi-client/client.h;endline=23;md5=f4ac741a25c4f434039ba3e18c8674cf"
 
-SRC_URI = "https://github.com/lathiat/avahi/releases/download/v${PV}/avahi-${PV}.tar.gz"
+SRC_URI = "https://github.com/lathiat/avahi/releases/download/v${PV}/avahi-${PV}.tar.gz \
+           file://fix-CVE-2017-6519.patch \
+           "
 
 UPSTREAM_CHECK_URI = "https://github.com/lathiat/avahi/releases/"
 SRC_URI[md5sum] = "d76c59d0882ac6c256d70a2a585362a6"
diff --git a/meta/recipes-connectivity/avahi/files/fix-CVE-2017-6519.patch b/meta/recipes-connectivity/avahi/files/fix-CVE-2017-6519.patch
new file mode 100644
index 0000000000..7461fe193d
--- /dev/null
+++ b/meta/recipes-connectivity/avahi/files/fix-CVE-2017-6519.patch
@@ -0,0 +1,48 @@
+Upstream-Status: Backport [https://github.com/lathiat/avahi/commit/e111def]
+
+CVE: CVE-2017-6519
+
+Signed-off-by: Kai Kang <kai.kang@windriver.com>
+
+From e111def44a7df4624a4aa3f85fe98054bffb6b4f Mon Sep 17 00:00:00 2001
+From: Trent Lloyd <trent@lloyd.id.au>
+Date: Sat, 22 Dec 2018 09:06:07 +0800
+Subject: [PATCH] Drop legacy unicast queries from address not on local link
+
+When handling legacy unicast queries, ensure that the source IP is
+inside a subnet on the local link, otherwise drop the packet.
+
+Fixes #145
+Fixes #203
+CVE-2017-6519
+CVE-2018-1000845
+---
+ avahi-core/server.c | 8 ++++++++
+ 1 file changed, 8 insertions(+)
+
+diff --git a/avahi-core/server.c b/avahi-core/server.c
+index a2cb19a8..a2580e38 100644
+--- a/avahi-core/server.c
++++ b/avahi-core/server.c
+@@ -930,6 +930,7 @@ static void dispatch_packet(AvahiServer *s, AvahiDnsPacket *p, const AvahiAddres
+ 
+     if (avahi_dns_packet_is_query(p)) {
+         int legacy_unicast = 0;
++        char t[AVAHI_ADDRESS_STR_MAX];
+ 
+         /* For queries EDNS0 might allow ARCOUNT != 0. We ignore the
+          * AR section completely here, so far. Until the day we add
+@@ -947,6 +948,13 @@ static void dispatch_packet(AvahiServer *s, AvahiDnsPacket *p, const AvahiAddres
+             legacy_unicast = 1;
+         }
+ 
++        if (!is_mdns_mcast_address(dst_address) &&
++            !avahi_interface_address_on_link(i, src_address)) {
++
++            avahi_log_debug("Received non-local unicast query from host %s on interface '%s.%i'.", avahi_address_snprint(t, sizeof(t), src_address), i->hardware->name, i->protocol);
++            return;
++        }
++
+         if (legacy_unicast)
+             reflect_legacy_unicast_query_packet(s, p, i, src_address, port);
+