Samsung Dealing With Wayland "Zombie Apocalypse" Bug

Samsung OSG developers have been investigating and dealing with a nasty Wayland bug whereby a Wayland event could be delivered to an incorrect file descriptor. This ends up being due to a shortcoming in the Wayland protocol, but as to not break all existing software out there built against the current Wayland protocol, a workaround has been devised.

Longtime Wayland developer Derek Foreman has written a blog post about the "Wayland Zombie Apocalypse" and talks about this issue that comes up since file descriptors aren't part of the main data stream that in some cases they get leaked when deleting a Wayland object. The bug could lead to the file descriptor being leaked to the Wayland client and counting against the number of allowed open file descriptors, but worse could lead to unknown behavior due to events going to incorrect FDs.

With not wanting to change the protocol and break existing software, Derek has been working on improvements around Wayland's handling of file descriptor leaks and replacing a single zombie object in the client library with "an army of bespoke zombies" -- creating a zombie each time an object is instantiated and will live on past the object's lifespan.

More details on the Wayland Zombie Apocalypse via the Samsung OSG blog.