AMD SEV-SNP: privileged attacker can overlap MMIO regions with DRAM, breaking guest memory integrity

Impact

SEV-SNP does not check for MMIO regions that overlap DRAM. A privileged attacker who sets up such an overlap can undermine the integrity of SEV-SNP guest memory. The record names integrity loss only. Most EPYC generations in GPU fleets are listed (7003, 8004, 8005, 9004, 9005 and the Embedded variants), so any host offering confidential VMs is likely affected.

Who can reach it

Requires high privilege on the host (hypervisor or host root). Not reachable from a guest or the network.

What to do

Apply the fix from AMD-SB-3038 for the affected EPYC generation. The record gives no fixed version or delivery mechanism. Get the platform firmware release from the bulletin and your OEM, and schedule host maintenance for SEV-SNP nodes.

References

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