diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index e62c118..5dbb39d 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4509,7 +4509,7 @@
     const int originPid = ipc->getCallingPid();
     const int originUid = ipc->getCallingUid();
     uint32_t permissions = LayerStatePermissions::getTransactionPermissions(originPid, originUid);
-    for (auto composerState : states) {
+    for (auto& composerState : states) {
         composerState.state.sanitize(permissions);
     }
 
diff --git a/services/surfaceflinger/tests/Credentials_test.cpp b/services/surfaceflinger/tests/Credentials_test.cpp
index 69e9a16..2d18166 100644
--- a/services/surfaceflinger/tests/Credentials_test.cpp
+++ b/services/surfaceflinger/tests/Credentials_test.cpp
@@ -401,8 +401,13 @@
                 .apply();
     }
 
-    // Called from non privileged process
-    Transaction().setTrustedOverlay(surfaceControl, true);
+    // Attempt to set a trusted overlay from a non-privileged process. This should fail silently.
+    {
+        UIDFaker f{AID_BIN};
+        Transaction().setTrustedOverlay(surfaceControl, true).apply(/*synchronous=*/true);
+    }
+
+    // Verify that the layer was not made a trusted overlay.
     {
         UIDFaker f(AID_SYSTEM);
         auto windowIsPresentAndNotTrusted = [&](const std::vector<WindowInfo>& windowInfos) {
@@ -413,12 +418,14 @@
             }
             return !foundWindowInfo->inputConfig.test(WindowInfo::InputConfig::TRUSTED_OVERLAY);
         };
-        windowInfosListenerUtils.waitForWindowInfosPredicate(windowIsPresentAndNotTrusted);
+        ASSERT_TRUE(
+                windowInfosListenerUtils.waitForWindowInfosPredicate(windowIsPresentAndNotTrusted));
     }
 
+    // Verify that privileged processes are able to set trusted overlays.
     {
         UIDFaker f(AID_SYSTEM);
-        Transaction().setTrustedOverlay(surfaceControl, true);
+        Transaction().setTrustedOverlay(surfaceControl, true).apply(/*synchronous=*/true);
         auto windowIsPresentAndTrusted = [&](const std::vector<WindowInfo>& windowInfos) {
             auto foundWindowInfo =
                     WindowInfosListenerUtils::findMatchingWindowInfo(windowInfo, windowInfos);
@@ -427,7 +434,8 @@
             }
             return foundWindowInfo->inputConfig.test(WindowInfo::InputConfig::TRUSTED_OVERLAY);
         };
-        windowInfosListenerUtils.waitForWindowInfosPredicate(windowIsPresentAndTrusted);
+        ASSERT_TRUE(
+                windowInfosListenerUtils.waitForWindowInfosPredicate(windowIsPresentAndTrusted));
     }
 }