EDK2 SMM MCE Enablement Issue
Summary
A researcher reported a bug in the open source EDK2 system management interrupt (SMI) entry code when an MCE occurs near the start of the SMI handler. An attacker who can inject a machine check exception (MCE) could cause execution to jump to an attacker-controlled interrupt handler, leading to arbitration code execution.
AMD believes the EDK2 bug does not affect non-EOL AMD products because modern AMD EPYC™ and Ryzen™ processors are designed to prohibit software from injecting asynchronous MCEs, and physical attacks are outside the system management mode (SMM) threat model. For AMD products that have been discontinued (EOL), customers concerned with the physical attack vector should apply the EDK2 mitigation once it is available.
Acknowledgement
External researcher declined acknowledgement
Revisions
| Revision Date | Description |
| 2025-08-06 | Initial publication |
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