Insyde InsydeH2O (NvmExpressDxe, incorrect pointer checks): The NVMe driver's pointer validation is wrong, allowing

Impact

The NVMe driver's pointer validation is wrong, allowing tampering with both SMRAM and OS memory. The driver reaches the NVMe data path - datasets, checkpoints, weights on a GPU node - and the bug hands an OS-level attacker ring -2 on top of it. Distinct from the DMA race in SA-2022055 and separately fixed; a node can carry one and not the other.

Who can reach it

Local admin/root on the host OS invoking the vulnerable software SMI with attacker-chosen pointers. On bare-metal GPU rental this is exactly the privilege the tenant already holds on their leased node.

What to do

Firmware flash from the server OEM, not from Insyde - the fixed Insyde kernel has to be rebased by Dell/HPE/Lenovo/Supermicro and re-qualified before it reaches you, which for this batch ran months behind Insyde's own release. One reboot per node, so schedule it against a GPU drain. Fixed in kernel 5.1 / 05.17.23 through 5.5 / 05.52.23. The compensating control that actually works here is the IOMMU, and Insyde says so in the advisory: enable VT-d/AMD-Vi with pre-boot DMA protection so the ACPI runtime buffer the handler reads is not reachable by an untrusted device. That is a BIOS setting, deployable fleet-wide without a flash, and it should be on already on any node that passes devices through to tenants. Patch the batch, not the CVE - Insyde filed one advisory per driver for the same defect, so fixing this one leaves every sibling handler reachable.

References