While implementing a ray tracing renderer with the new Vulkan ray tracing extensions I found that the acceleration structure size returned by vkGetAccelerationStructureBuildSizesKHR seems to be too small to correctly work, causing part of the acceleration structure data to exceed the buffer allocation and overwriting other data.
To observe this issue it is crucial to have the allocations be contiguous and to be placed after the acceleration structure storage buffer to be affected. Multiplying the returned size by two seems to provide enough padding for this not to be an issue, but I’m pretty certain this is a bug.
NVIDIA Beta Vulkan Driver 457.67, on Windows 10.