busybox: Security fix CVE-2016-6301

ntpd: NTP server denial of service flaw

CVE: CVE-2016-6301
(From OE-Core rev: dafbf8a9e9ed068ecbf22cc816f9a6a3a2da7aa9)

Signed-off-by: Andrej Valek <andrej.valek@siemens.com>
Signed-off-by: Pascal Bach <pascal.bach@siemens.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 301dc9df16cce1f4649f90af47159bc21be0de59)
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 38 insertions, 0 deletions

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 0000000000..851bc20f79
--- /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@siemens.com>
+Signed-off-by: Pascal Bach <pascal.bach@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 f6c759584f..cb4568854c 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 \