[OE-core] [PATCH v2] busybox: Security fix CVE-2016-6301

[Andrej Valek]

ntpd: NTP server denial of service flaw

CVE: CVE-2016-6301
Signed-off-by: Andrej Valek <andrej.valek at siemens.com>
Signed-off-by: Pascal Bach <pascal.bach at siemens.com>
---
 .../busybox/busybox/CVE-2016-6301.patch            | 37 ++++++++++++++++++++++
 meta/recipes-core/busybox/busybox_1.24.1.bb        |  1 +
 2 files changed, 38 insertions(+)
 create mode 100644 meta/recipes-core/busybox/busybox/CVE-2016-6301.patch

diff --git a/meta/recipes-core/busybox/busybox/CVE-2016-6301.patch b/meta/recipes-core/busybox/busybox/CVE-2016-6301.patch
new file mode 100644
index 0000000..851bc20
--- /dev/null
+++ b/meta/recipes-core/busybox/busybox/CVE-2016-6301.patch
@@ -0,0 +1,37 @@
+busybox1.24.1: Fix CVE-2016-6301
+
+[No upstream tracking] -- https://bugzilla.redhat.com/show_bug.cgi?id=1363710
+
+ntpd: NTP server denial of service flaw
+
+The busybox NTP implementation doesn't check the NTP mode of packets
+received on the server port and responds to any packet with the right
+size. This includes responses from another NTP server. An attacker can
+send a packet with a spoofed source address in order to create an
+infinite loop of responses between two busybox NTP servers. Adding
+more packets to the loop increases the traffic between the servers
+until one of them has a fully loaded CPU and/or network.
+
+Upstream-Status: Backport [https://git.busybox.net/busybox/commit/?id=150dc7a2b483b8338a3e185c478b4b23ee884e71]
+CVE: CVE-2016-6301
+Signed-off-by: Andrej Valek <andrej.valek at siemens.com>
+Signed-off-by: Pascal Bach <pascal.bach at siemens.com>
+
+diff --git a/networking/ntpd.c b/networking/ntpd.c
+index 9732c9b..0f6a55f 100644
+--- a/networking/ntpd.c
++++ b/networking/ntpd.c
+@@ -1985,6 +1985,13 @@ recv_and_process_client_pkt(void /*int fd*/)
+ 		goto bail;
+ 	}
+ 
++	/* Respond only to client and symmetric active packets */
++	if ((msg.m_status & MODE_MASK) != MODE_CLIENT
++	 && (msg.m_status & MODE_MASK) != MODE_SYM_ACT
++	) {
++		goto bail;
++	}
++
+ 	query_status = msg.m_status;
+ 	query_xmttime = msg.m_xmttime;
+ 
diff --git a/meta/recipes-core/busybox/busybox_1.24.1.bb b/meta/recipes-core/busybox/busybox_1.24.1.bb
index 41fc641..6013ec9 100644
--- a/meta/recipes-core/busybox/busybox_1.24.1.bb
+++ b/meta/recipes-core/busybox/busybox_1.24.1.bb
@@ -47,6 +47,7 @@ SRC_URI = "http://www.busybox.net/downloads/busybox-${PV}.tar.bz2;name=tarball \
            file://CVE-2016-2148.patch \
            file://CVE-2016-2147.patch \
            file://CVE-2016-2147_2.patch \
+           file://CVE-2016-6301.patch \
            file://ip_fix_problem_on_mips64_n64_big_endian_musl_systems.patch \
            file://makefile-fix-backport.patch \
            file://0001-sed-fix-sed-n-flushes-pattern-space-terminates-early.patch \
-- 
2.1.4