Snap for 4485699 from 9f30f3bbf30b7de0ad3850171db968ae12a6caf0 to oc-m2-release
Change-Id: Ia84c5d6f459736d07f4ec01dbb5c0b721b5f10e0
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);
