fix(client_openxr): 🐛 Fix crash caused by undefined behavior #2391
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The-personified-devil
approved these changes
Sep 13, 2024
zmerp
added a commit
that referenced
this pull request
Sep 20, 2024
zmerp
added a commit
that referenced
this pull request
Sep 20, 2024
Merged
zmerp
added a commit
that referenced
this pull request
Sep 21, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR attempts to fix a crash reported when enabling face tracking on the Quest Pro.
This PR fixes undefined behavior using a specific solution. Before we were calling
System<props>::out()which returns aMaybeUninit, and immediately callassume_uninit(). Doing so only the correspondingBaseOutStructurefields are initialized, that istyandnext. The other fields are filled with random values. Beside this, callingassume_uninit()after attempting to get the properties withget_system_propertiesis not enough. The OpenXR spec doesn't say to return an error if thenextpointer is populated with an unknown structure. So after theget_system_propertiescall, theSystem<props>struct might still contain random values. Because of this we should ditch theout()method and manually initialize the structure. The upstreamopenxrscrate suffers from the same bug, but only concerning the hand tracking extension. That instance of the bug hasn't surfaced yet.