diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 29a8292..801e8dd 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2656,8 +2656,13 @@
         if (parent == nullptr) {
             mCurrentState.layersSortedByZ.add(lbc);
         } else {
+            if (mCurrentState.layersSortedByZ.indexOf(parent) < 0) {
+                ALOGE("addClientLayer called with a removed parent");
+                return NAME_NOT_FOUND;
+            }
             parent->addChild(lbc);
         }
+
         mGraphicBufferProducerList.add(IInterface::asBinder(gbc));
         mLayersAdded = true;
         mNumLayers++;
@@ -2676,6 +2681,17 @@
     const ssize_t index = (p != nullptr) ? p->removeChild(layer) :
         mCurrentState.layersSortedByZ.remove(layer);
 
+    if (p != nullptr) {
+        sp<Layer> ancestor = p;
+        while (ancestor->getParent() != nullptr) {
+            ancestor = ancestor->getParent();
+        }
+        if (mCurrentState.layersSortedByZ.indexOf(ancestor) < 0) {
+            ALOGE("removeLayer called with a layer whose parent has been removed");
+            return NAME_NOT_FOUND;
+        }
+    }
+
     // As a matter of normal operation, the LayerCleaner will produce a second
     // attempt to remove the surface. The Layer will be kept alive in mDrawingState
     // so we will succeed in promoting it, but it's already been removed
@@ -2692,7 +2708,7 @@
 
     mLayersPendingRemoval.add(layer);
     mLayersRemoved = true;
-    mNumLayers--;
+    mNumLayers -= 1 + layer->getChildrenCount();
     setTransactionFlags(eTransactionNeeded);
     return NO_ERROR;
 }