AMD Processor Security - Previous Updates
An Update on AMD Processor Security
The public disclosure on January 3rd that multiple research teams had discovered security issues related to how modern microprocessors handle speculative execution has brought to the forefront the constant vigilance needed to protect and secure data. These threats seek to circumvent the microprocessor architecture controls that preserve secure data.
At AMD, security is our top priority and we are continually working to ensure the safety of our users as new risks arise. As a part of that vigilance, I wanted to update the community on our actions to address the situation.
- Google Project Zero (GPZ) Variant 1 (Bounds Check Bypass or Spectre) is applicable to AMD processors.
- We believe this threat can be contained with an operating system (OS) patch and we have been working with OS providers to address this issue.
- Microsoft is distributing patches for the majority of AMD systems now. We are working closely with them to correct an issue that paused the distribution of patches for some older AMD processors (AMD Opteron, Athlon and AMD Turion X2 Ultra families) earlier this week. We expect this issue to be corrected shortly and Microsoft should resume updates for these older processors by next week. For the latest details, please see Microsoft’s website.
- Linux vendors are also rolling out patches across AMD products now.
- GPZ Variant 2 (Branch Target Injection or Spectre) is applicable to AMD processors.
- While we believe that AMD’s processor architectures make it difficult to exploit Variant 2, we continue to work closely with the industry on this threat. We have defined additional steps through a combination of processor microcode updates and OS patches that we will make available to AMD customers and partners to further mitigate the threat.
- AMD will make optional microcode updates available to our customers and partners for Ryzen and EPYC processors starting this week. We expect to make updates available for our previous generation products over the coming weeks. These software updates will be provided by system providers and OS vendors; please check with your supplier for the latest information on the available option for your configuration and requirements.
- Linux vendors have begun to roll out OS patches for AMD systems, and we are working closely with Microsoft on the timing for distributing their patches. We are also engaging closely with the Linux community on development of “return trampoline” (Retpoline) software mitigations.
- GPZ Variant 3 (Rogue Data Cache Load or Meltdown) is not applicable to AMD processors.
- We believe AMD processors are not susceptible due to our use of privilege level protections within paging architecture and no mitigation is required.
There have also been questions about GPU architectures. AMD Radeon GPU architectures do not use speculative execution and thus are not susceptible to these threats.
We will provide further updates as appropriate on this site as AMD and the industry continue our collaborative work to develop mitigation solutions to protect users from these latest security threats.
Senior Vice President and Chief Technology Officer
Information Security is a Priority at AMD
There has been recent press coverage regarding a potential security issue related to modern microprocessors and speculative execution. Information security is a priority at AMD, and our security architects follow the technology ecosystem closely for new threats.
It is important to understand how the speculative execution vulnerability described in the research relates to AMD products, but please keep in mind the following:
- The research described was performed in a controlled, dedicated lab environment by a highly knowledgeable team with detailed, non-public information about the processors targeted.
- The described threat has not been seen in the public domain.
When AMD learned that researchers had discovered a new CPU attack targeting the speculative execution functionality used by multiple chip companies’ products, we immediately engaged across the ecosystem to address the teams’ findings.
The research team identified three variants within the speculative execution research. The below grid details the specific variants detailed in the research and the AMD response details.
Variant / AMD Response Matrix
|Google Project Zero (GPZ) Research Title||Details|
|Variant One||Bounds Check Bypass||Resolved by software / OS updates to be made available by system vendors and manufacturers. Negligible performance impact expected.|
|Variant Two||Branch Target Injection||Differences in AMD architecture mean there is a near zero risk of exploitation of this variant. Vulnerability to Variant 2 has not been demonstrated on AMD processors to date.|
|Variant Three||Rogue Data Cache Load||Zero AMD vulnerability due to AMD architecture differences.|
As the security landscape continues to evolve, a collaborative effort of information sharing in the industry represents the strongest defense.
Total protection from all possible attacks remains an elusive goal and this latest example shows how effective industry collaboration can be.
As always, AMD strongly encourages its customers to consistently undertake safe computing practices, examples of which include: not clicking on unrecognized hyperlinks, following strong password protocols, using secure networks, and accepting regular software updates.