Merge "[DO NOT MERGE] Verify URI Permissions in Autofill RemoteViews" into sc-dev

services/autofill/java/com/android/server/autofill/Helper.java

@@ -18,6 +18,8 @@ package com.android.server.autofill;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.annotation.UserIdInt;
+import android.app.ActivityManager;
 import android.app.assist.AssistStructure;
 import android.app.assist.AssistStructure.ViewNode;
 import android.app.assist.AssistStructure.WindowNode;
@@ -34,6 +36,7 @@ import android.view.View;
 import android.view.WindowManager;
 import android.view.autofill.AutofillId;
 import android.view.autofill.AutofillValue;
+import android.widget.RemoteViews;
 
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
 import com.android.internal.util.ArrayUtils;
@@ -42,6 +45,8 @@ import java.io.PrintWriter;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.concurrent.atomic.AtomicBoolean;
+
 
 public final class Helper {
 
@@ -75,6 +80,44 @@ public final class Helper {
         throw new UnsupportedOperationException("contains static members only");
     }
 
+    private static boolean checkRemoteViewUriPermissions(
+            @UserIdInt int userId, @NonNull RemoteViews rView) {
+        final AtomicBoolean permissionsOk = new AtomicBoolean(true);
+
+        rView.visitUris(uri -> {
+            int uriOwnerId = android.content.ContentProvider.getUserIdFromUri(uri);
+            boolean allowed = uriOwnerId == userId;
+            permissionsOk.set(allowed && permissionsOk.get());
+        });
+
+        return permissionsOk.get();
+    }
+
+    /**
+     * Checks the URI permissions of the remote view,
+     * to see if the current userId is able to access it.
+     *
+     * Returns the RemoteView that is passed if user is able, null otherwise.
+     *
+     * TODO: instead of returning a null remoteview when
+     * the current userId cannot access an URI,
+     * return a new RemoteView with the URI removed.
+     */
+    public static @Nullable RemoteViews sanitizeRemoteView(RemoteViews rView) {
+        if (rView == null) return null;
+
+        int userId = ActivityManager.getCurrentUser();
+
+        boolean ok = checkRemoteViewUriPermissions(userId, rView);
+        if (!ok) {
+            Slog.w(TAG,
+                    "sanitizeRemoteView() user: " + userId
+                    + " tried accessing resource that does not belong to them");
+        }
+        return (ok ? rView : null);
+    }
+
+
     @Nullable
     static AutofillId[] toArray(@Nullable ArraySet<AutofillId> set) {
         if (set == null) return null;

services/autofill/java/com/android/server/autofill/ui/FillUi.java

@@ -141,8 +141,9 @@ final class FillUi {
 
         final LayoutInflater inflater = LayoutInflater.from(mContext);
 
-        final RemoteViews headerPresentation = response.getHeader();
+        final RemoteViews headerPresentation = Helper.sanitizeRemoteView(response.getHeader());
-        final RemoteViews footerPresentation = response.getFooter();
+        final RemoteViews footerPresentation = Helper.sanitizeRemoteView(response.getFooter());
+
         final ViewGroup decor;
         if (mFullScreen) {
             decor = (ViewGroup) inflater.inflate(R.layout.autofill_dataset_picker_fullscreen, null);
@@ -220,6 +221,9 @@ final class FillUi {
             ViewGroup container = decor.findViewById(R.id.autofill_dataset_picker);
             final View content;
             try {
+                if (Helper.sanitizeRemoteView(response.getPresentation()) == null) {
+                    throw new RuntimeException("Permission error accessing RemoteView");
+                }
                 content = response.getPresentation().applyWithTheme(
                         mContext, decor, interceptionHandler, mThemeId);
                 container.addView(content);
@@ -299,7 +303,8 @@ final class FillUi {
                 final Dataset dataset = response.getDatasets().get(i);
                 final int index = dataset.getFieldIds().indexOf(focusedViewId);
                 if (index >= 0) {
-                    final RemoteViews presentation = dataset.getFieldPresentation(index);
+                    final RemoteViews presentation = Helper.sanitizeRemoteView(
+                            dataset.getFieldPresentation(index));
                     if (presentation == null) {
                         Slog.w(TAG, "not displaying UI on field " + focusedViewId + " because "
                                 + "service didn't provide a presentation for it on " + dataset);

services/autofill/java/com/android/server/autofill/ui/SaveUi.java

@@ -368,8 +368,7 @@ final class SaveUi {
             return false;
         }
         writeLog(MetricsEvent.AUTOFILL_SAVE_CUSTOM_DESCRIPTION);
-
+        final RemoteViews template = Helper.sanitizeRemoteView(customDescription.getPresentation());
-        final RemoteViews template = customDescription.getPresentation();
         if (template == null) {
             Slog.w(TAG, "No remote view on custom description");
             return false;