From b1cd6cec19de46540db497137e2b93fee5c9ff17 Mon Sep 17 00:00:00 2001 From: Liam Date: Mon, 10 Oct 2022 19:22:26 -0400 Subject: [PATCH] syncpoint_manager: ensure handle is removable before removing --- src/video_core/host1x/syncpoint_manager.cpp | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/src/video_core/host1x/syncpoint_manager.cpp b/src/video_core/host1x/syncpoint_manager.cpp index 326e8355ad..a44fc83d3d 100644 --- a/src/video_core/host1x/syncpoint_manager.cpp +++ b/src/video_core/host1x/syncpoint_manager.cpp @@ -36,7 +36,17 @@ SyncpointManager::ActionHandle SyncpointManager::RegisterAction( void SyncpointManager::DeregisterAction(std::list& action_storage, ActionHandle& handle) { std::unique_lock lk(guard); - action_storage.erase(handle); + + // We want to ensure the iterator still exists prior to erasing it + // Otherwise, if an invalid iterator was passed in then it could lead to UB + // It is important to avoid UB in that case since the deregister isn't called from a locked + // context + for (auto it = action_storage.begin(); it != action_storage.end(); it++) { + if (it == handle) { + action_storage.erase(it); + return; + } + } } void SyncpointManager::DeregisterGuestAction(u32 syncpoint_id, ActionHandle& handle) {