commit ef7b1333f0e87cd07af115719b94dd37e2de54dc
author Andrii Kulian <akulian@google.com> Fri Jul 31 18:46:28 2020 -0700
committer Charles Chen <charlesccchen@google.com> Tue Sep 01 05:24:41 2020 +0000
tree 38e6deb92a4a1010779d5fcbe99f8276df738d0f
parent 0ac2f4e4f7bd289274276f1222d9e81aa386e82f

Require permission to create trusted displays

Bug: 162627132
Test: atest VirtualDisplayTest#testTrustedVirtualDisplay
Test: atest
frameworks/base/packages/SystemUI/tests/src/com/android/systemui/bubbles
Test: atest DisplayTest
Test: atest VirtualDisplayTest#testTrustedVirtualDisplay
Test: atest VirtualDisplayTest#testUntrustedSysDecorVirtualDisplay
Test: adb logcat -b events

Change-Id: Id06b2013ef5fdeadf321f14f8b611c733031d54d
Merged-In: Id06b2013ef5fdeadf321f14f8b611c733031d54d

services/core/java/com/android/server/display/DisplayManagerService.java

diff --git a/services/core/java/com/android/server/display/DisplayManagerService.java b/services/core/java/com/android/server/display/DisplayManagerService.java
index 24661d6..8528686 100644
--- a/services/core/java/com/android/server/display/DisplayManagerService.java
+++ b/services/core/java/com/android/server/display/DisplayManagerService.java
@@ -86,6 +86,7 @@
 import android.os.UserManager;
 import android.provider.Settings;
 import android.text.TextUtils;
+import android.util.EventLog;
 import android.util.IntArray;
 import android.util.Pair;
 import android.util.Slog;
@@ -2191,10 +2192,16 @@
                 }
             }
 
-            if (callingUid == Process.SYSTEM_UID
-                    || checkCallingPermission(ADD_TRUSTED_DISPLAY, "createVirtualDisplay()")) {
-                flags |= VIRTUAL_DISPLAY_FLAG_TRUSTED;
-            } else {
+            if (callingUid != Process.SYSTEM_UID && (flags & VIRTUAL_DISPLAY_FLAG_TRUSTED) != 0) {
+                if (!checkCallingPermission(ADD_TRUSTED_DISPLAY, "createVirtualDisplay()")) {
+                    EventLog.writeEvent(0x534e4554, "162627132", callingUid,
+                            "Attempt to create a trusted display without holding permission!");
+                    throw new SecurityException("Requires ADD_TRUSTED_DISPLAY permission to "
+                            + "create a trusted virtual display.");
+                }
+            }
+
+            if ((flags & VIRTUAL_DISPLAY_FLAG_TRUSTED) == 0) {
                 flags &= ~VIRTUAL_DISPLAY_FLAG_SHOULD_SHOW_SYSTEM_DECORATIONS;
             }