Do not allow updates to the _data column.

Fixes a security hole where applications can update the data location of
voicemail files to point to arbitrary file paths.

Voicemail provider stores the location of the data file in the _data column.
Applications can update this with an arbitrary file path as long as they
have the ADD_VOICEMAIL permission.  Then they can subsequently read that
voicemail and obtain access to the file. This location is generated by the
provider and does not need to be updated by the applications.

Bug: 9674953
Change-Id: I9c8fc45071a06d627574a52bafbd9e6e172b4bf8

2 files changed, 33 insertions, 3 deletions

diff --git a/src/com/android/providers/contacts/VoicemailContentTable.java b/src/com/android/providers/contacts/VoicemailContentTable.java
index 3f00b262..5ef5ebba 100644
--- a/src/com/android/providers/contacts/VoicemailContentTable.java
+++ b/src/com/android/providers/contacts/VoicemailContentTable.java
@@ -34,6 +34,8 @@ import android.provider.OpenableColumns;
 import android.provider.VoicemailContract.Voicemails;
 import android.util.Log;
 
+import com.google.common.collect.ImmutableSet;
+
 import com.android.common.content.ProjectionMap;
 import com.android.providers.contacts.VoicemailContentProvider.UriData;
 import com.android.providers.contacts.util.CloseUtils;
@@ -54,6 +56,21 @@ public class VoicemailContentTable implements VoicemailTable.Delegate {
 
     private static final String[] FILENAME_ONLY_PROJECTION = new String[] { Voicemails._DATA };
 
+    private static final ImmutableSet<String> ALLOWED_COLUMNS = new ImmutableSet.Builder<String>()
+            .add(Voicemails._ID)
+            .add(Voicemails.NUMBER)
+            .add(Voicemails.DATE)
+            .add(Voicemails.DURATION)
+            .add(Voicemails.IS_READ)
+            .add(Voicemails.STATE)
+            .add(Voicemails.SOURCE_DATA)
+            .add(Voicemails.SOURCE_PACKAGE)
+            .add(Voicemails.HAS_CONTENT)
+            .add(Voicemails.MIME_TYPE)
+            .add(OpenableColumns.DISPLAY_NAME)
+            .add(OpenableColumns.SIZE)
+            .build();
+
     private final String mTableName;
     private final SQLiteOpenHelper mDbHelper;
     private final Context mContext;
@@ -211,8 +228,10 @@ public class VoicemailContentTable implements VoicemailTable.Delegate {
     @Override
     public int update(UriData uriData, ContentValues values, String selection,
             String[] selectionArgs) {
-        checkForSupportedColumns(mVoicemailProjectionMap, values);
+
+        checkForSupportedColumns(ALLOWED_COLUMNS, values, "Updates are not allowed.");
         checkUpdateSupported(uriData);
+
         final SQLiteDatabase db = mDbHelper.getWritableDatabase();
         // TODO: This implementation does not allow bulk update because it only accepts
         // URI that include message Id. I think we do want to support bulk update.
diff --git a/src/com/android/providers/contacts/util/DbQueryUtils.java b/src/com/android/providers/contacts/util/DbQueryUtils.java
index c184613f..d719313a 100644
--- a/src/com/android/providers/contacts/util/DbQueryUtils.java
+++ b/src/com/android/providers/contacts/util/DbQueryUtils.java
@@ -20,6 +20,7 @@ import android.database.DatabaseUtils;
 import android.text.TextUtils;
 
 import java.util.HashMap;
+import java.util.Set;
 
 /**
  * Static methods for helping us build database query selection strings.
@@ -83,14 +84,24 @@ public class DbQueryUtils {
     /**
      * Checks if the given ContentValues contains values within the projection
      * map.
+     *
      * @throws IllegalArgumentException if any value in values is not found in
      * the projection map.
      */
     public static void checkForSupportedColumns(HashMap<String, String> projectionMap,
             ContentValues values) {
+        checkForSupportedColumns(projectionMap.keySet(), values, "Is invalid.");
+    }
+
+    /**
+     * @see #checkForSupportedColumns(HashMap, ContentValues)
+     */
+    public static void checkForSupportedColumns(Set<String> allowedColumns, ContentValues values,
+            String msgSuffix) {
         for (String requestedColumn : values.keySet()) {
-            if (!projectionMap.keySet().contains(requestedColumn)) {
-                throw new IllegalArgumentException("Column '" + requestedColumn + "' is invalid.");
+            if (!allowedColumns.contains(requestedColumn)) {
+                throw new IllegalArgumentException("Column '" + requestedColumn + "'. " +
+                        msgSuffix);
             }
         }
     }