Don't allow clients to update or insert _data column data

Bug 8214355

Change-Id: I45c93047ced465277a46c6a33d6ef590ab0bf8bb
diff --git a/src/com/android/providers/telephony/MmsProvider.java b/src/com/android/providers/telephony/MmsProvider.java
index bddce1d..3b17003 100644
--- a/src/com/android/providers/telephony/MmsProvider.java
+++ b/src/com/android/providers/telephony/MmsProvider.java
@@ -266,6 +266,10 @@
 
     @Override
     public Uri insert(Uri uri, ContentValues values) {
+        // Don't let anyone insert anything with the _data column
+        if (values != null && values.containsKey(Part._DATA)) {
+            return null;
+        }
         int msgBox = Mms.MESSAGE_BOX_ALL;
         boolean notify = true;
 
@@ -680,6 +684,10 @@
     @Override
     public int update(Uri uri, ContentValues values,
             String selection, String[] selectionArgs) {
+        // Don't let anyone update the _data column
+        if (values != null && values.containsKey(Part._DATA)) {
+            return 0;
+        }
         int match = sURLMatcher.match(uri);
         if (LOCAL_LOGV) {
             Log.v(TAG, "Update uri=" + uri + ", match=" + match);