Linux i915 GVT-g mediated GPU virtualisation: Unsafe cleanup of per-vGPU debugfs state when a mediated vGPU is

Impact

Unsafe cleanup of per-vGPU debugfs state when a mediated vGPU is destroyed. GVT-g is the mechanism that carves one physical Intel GPU into vGPUs handed to different VMs, so bugs in its lifecycle paths sit directly on the tenant boundary. Practical effect here is a host kernel crash triggered by a vGPU teardown.

Who can reach it

Reachable by whoever can cause a vGPU to be created and destroyed - the virtualisation control plane, or a tenant that can start and stop VMs.

What to do

Fix ships in the Linux kernel. Update the kernel and reboot the node - in practice this is a drain plus reboot because the accelerator driver cannot be unloaded while jobs hold device file descriptors. No BIOS or firmware update needed.

References