Mitigate the security vulnerability by sanitizing the transaction flags. am: 03d4458ea0

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/native/+/20892111

Change-Id: Id8c63fb401b3642ec7c3d765171a093bbebacdb7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index dfcef8fe7a..a76a21c5c4 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -276,6 +276,27 @@ void DisplayState::merge(const DisplayState& other) {
     }
 }
 
+void DisplayState::sanitize(bool privileged) {
+    if (what & DisplayState::eLayerStackChanged) {
+        if (!privileged) {
+            what &= ~DisplayState::eLayerStackChanged;
+            ALOGE("Stripped attempt to set eLayerStackChanged in sanitize");
+        }
+    }
+    if (what & DisplayState::eDisplayProjectionChanged) {
+        if (!privileged) {
+            what &= ~DisplayState::eDisplayProjectionChanged;
+            ALOGE("Stripped attempt to set eDisplayProjectionChanged in sanitize");
+        }
+    }
+    if (what & DisplayState::eSurfaceChanged) {
+        if (!privileged) {
+            what &= ~DisplayState::eSurfaceChanged;
+            ALOGE("Stripped attempt to set eSurfaceChanged in sanitize");
+        }
+    }
+}
+
 void layer_state_t::merge(const layer_state_t& other) {
     if (other.what & ePositionChanged) {
         what |= ePositionChanged;