Merge cherrypicks of [3276508, 3277765, 3277766, 3277904, 3276473, 3278009, 3278010, 3277767, 3277768, 3277769, 3277770, 3276509, 3276510, 3278011, 3278012, 3278013, 3278014, 3278099, 3278100, 3278101, 3278102, 3278103, 3278104, 3278105, 3278106, 3277800, 3276474, 3278015, 3278016, 3278017, 3278118, 3278119, 3278120, 3278121, 3278122, 3277946, 3277905, 3277947, 3277906, 3277751, 3278123, 3277752, 3278110, 3277771, 3277907, 3278095, 3277908, 3278111, 3277772, 3276475, 3276476] into oc-mr1-release

Change-Id: Ifa8110f04f5c0940ec625f48d536bfccb3613183

libnetutils/packet.c

diff --git a/libnetutils/packet.c b/libnetutils/packet.c
index e53a4c8..9ecdd4f 100644
--- a/libnetutils/packet.c
+++ b/libnetutils/packet.c
@@ -218,6 +218,20 @@
      * to construct the pseudo header used in the checksum calculation.
      */
     dhcp_size = ntohs(packet.udp.len) - sizeof(packet.udp);
+    /*
+     * check validity of dhcp_size.
+     * 1) cannot be negative or zero.
+     * 2) src buffer contains enough bytes to copy
+     * 3) cannot exceed destination buffer
+     */
+    if ((dhcp_size <= 0) ||
+        ((int)(nread - sizeof(struct iphdr) - sizeof(struct udphdr)) < dhcp_size) ||
+        ((int)sizeof(struct dhcp_msg) < dhcp_size)) {
+#if VERBOSE
+        ALOGD("Malformed Packet");
+#endif
+        return -1;
+    }
     saddr = packet.ip.saddr;
     daddr = packet.ip.daddr;
     nread = ntohs(packet.ip.tot_len);