Linux kernel (drivers/gpu/drm/xe): Every exec ioctl that bails on an input-validation error leaves an exec-queue

Impact

Every exec ioctl that bails on an input-validation error leaves an exec-queue reference permanently pinned. A tenant loops the ioctl with deliberately bad arguments and exhausts the finite GuC context id space and the GPU memory backing those queues, after which co-tenants can no longer create queues on that device.

Who can reach it

Tenant container holding /dev/dri/renderD* on Intel xe calls DRM_IOCTL_XE_EXEC in a loop with arguments chosen to fail validation after the exec-queue lookup. Deterministic, unprivileged, no race required.

What to do

Update to a kernel carrying the fix (stable commits below; no fixed_in published). Interim: cap per-tenant GPU context counts if your runtime supports it; otherwise a node reboot is the only way to reclaim the leaked queues.

References