NVIDIA vGPU software - Virtual GPU Manager (host-side vGPU plugin / nvidia.ko): A user inside a guest VM triggers a GPU

Impact

A user inside a guest VM triggers a GPU interrupt storm that lands on the hypervisor host, wedging the physical GPU. The attacker sits inside a tenant guest VM and the blast radius is the hypervisor host, which is running every other tenant's vGPU on the same physical GPU. This is precisely the boundary a vGPU-based multi-tenant offering is sold on. One tenant can take down every other tenant sharing that GPU with no memory-corruption skill required - it is a pure availability attack that any guest user can run.

Who can reach it

A tenant inside their own guest VM, driving the paravirtualised vGPU control interface. Several of these need only an unprivileged process in the guest; the rest need guest root, which a tenant already has on a VM they rented. No host credentials are involved at any point.

What to do

Patch the vGPU Manager on the hypervisor host per bulletin 5312. Cost: the highest of any class here. The host driver cannot be reloaded while vGPUs are attached, so every tenant VM on that hypervisor must be live-migrated or powered off - a full host drain. NVIDIA also enforces a supported host/guest driver skew, so budget a matching guest-driver campaign in the same window or tenants lose their vGPU on next boot.

References