Fix issue #8470131: Process thrash kills battery

Protect app widget broadcasts from abuse.

In this case the app was sending an APPWIDGET_UPDATE broadcast
without specifying a target, which (a) should not be allowed (you
should not be able to send updates to other apps), and (b) resulted
in every single potential app widget in the system being launched...
which was about 75 of them.

Change-Id: I9d48733610ce6d5a7c32e69a3e06b9f33bd79a34

1 files changed, 16 insertions, 4 deletions

diff --git a/core/java/android/appwidget/AppWidgetManager.java b/core/java/android/appwidget/AppWidgetManager.java
index e68d23aff721..1166e4b80319 100644
--- a/core/java/android/appwidget/AppWidgetManager.java
+++ b/core/java/android/appwidget/AppWidgetManager.java
@@ -49,8 +49,8 @@ public class AppWidgetManager {
     static final String TAG = "AppWidgetManager";
 
     /**
-     * Send this from your {@link AppWidgetHost} activity when you want to pick an AppWidget to display.
-     * The AppWidget picker activity will be launched.
+     * Activity action to launch from your {@link AppWidgetHost} activity when you want to
+     * pick an AppWidget to display.  The AppWidget picker activity will be launched.
      * <p>
      * You must supply the following extras:
      * <table>
@@ -89,8 +89,8 @@ public class AppWidgetManager {
             ACTION_KEYGUARD_APPWIDGET_PICK = "android.appwidget.action.KEYGUARD_APPWIDGET_PICK";
 
     /**
-     * Send this from your {@link AppWidgetHost} activity when you want to bind an AppWidget to
-     * display and bindAppWidgetIdIfAllowed returns false.
+     * Activity action to launch from your {@link AppWidgetHost} activity when you want to bind
+     * an AppWidget to display and bindAppWidgetIdIfAllowed returns false.
      * <p>
      * You must supply the following extras:
      * <table>
@@ -269,6 +269,9 @@ public class AppWidgetManager {
     /**
      * Sent when the custom extras for an AppWidget change.
      *
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
+     *
      * @see AppWidgetProvider#onAppWidgetOptionsChanged
      *      AppWidgetProvider.onAppWidgetOptionsChanged(Context context,
      *      AppWidgetManager appWidgetManager, int appWidgetId, Bundle newExtras)
@@ -278,6 +281,9 @@ public class AppWidgetManager {
     /**
      * Sent when an instance of an AppWidget is deleted from its host.
      *
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
+     *
      * @see AppWidgetProvider#onDeleted AppWidgetProvider.onDeleted(Context context, int[] appWidgetIds)
      */
     public static final String ACTION_APPWIDGET_DELETED = "android.appwidget.action.APPWIDGET_DELETED";
@@ -285,6 +291,9 @@ public class AppWidgetManager {
     /**
      * Sent when an instance of an AppWidget is removed from the last host.
      *
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
+     *
      * @see AppWidgetProvider#onEnabled AppWidgetProvider.onEnabled(Context context)
      */
     public static final String ACTION_APPWIDGET_DISABLED = "android.appwidget.action.APPWIDGET_DISABLED";
@@ -294,6 +303,9 @@ public class AppWidgetManager {
      * This broadcast is sent at boot time if there is a AppWidgetHost installed with
      * an instance for this provider.
      *
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
+     *
      * @see AppWidgetProvider#onEnabled AppWidgetProvider.onEnabled(Context context)
      */
     public static final String ACTION_APPWIDGET_ENABLED = "android.appwidget.action.APPWIDGET_ENABLED";