HDCP: buffer over flow check -- DO NOT MERGE

bug: 20222489
Change-Id: I3a64a5999d68ea243d187f12ec7717b7f26d93a3
(cherry picked from commit 532cd7b86a5fdc7b9a30a45d8ae2d16ef7660a72)

media/libmedia/IHDCP.cpp

diff --git a/media/libmedia/IHDCP.cpp b/media/libmedia/IHDCP.cpp
index 1cf987a..9d93320 100644
--- a/media/libmedia/IHDCP.cpp
+++ b/media/libmedia/IHDCP.cpp
@@ -241,8 +241,19 @@
         case HDCP_ENCRYPT:
         {
             size_t size = data.readInt32();
+            size_t bufSize = 2 * size;
 
-            void *inData = malloc(2 * size);
+            // watch out for overflow
+            void *inData = NULL;
+            if (bufSize > size) {
+                inData = malloc(bufSize);
+            }
+
+            if (inData == NULL) {
+                reply->writeInt32(ERROR_OUT_OF_RANGE);
+                return OK;
+            }
+
             void *outData = (uint8_t *)inData + size;
 
             data.read(inData, size);
@@ -295,8 +306,19 @@
         case HDCP_DECRYPT:
         {
             size_t size = data.readInt32();
+            size_t bufSize = 2 * size;
 
-            void *inData = malloc(2 * size);
+            // watch out for overflow
+            void *inData = NULL;
+            if (bufSize > size) {
+                inData = malloc(bufSize);
+            }
+
+            if (inData == NULL) {
+                reply->writeInt32(ERROR_OUT_OF_RANGE);
+                return OK;
+            }
+
             void *outData = (uint8_t *)inData + size;
 
             data.read(inData, size);