AMD’s Counter to “ZENHAMMER: Rowhammer Attacks on Zen-Based AMD Platforms” Raises Eyebrows

In a recent development, AMD has received research from ETH Zurich regarding a concerning DRAM issue known as “ZENHAMMER: Rowhammering Attacks on AMD Zen-based Platforms.” This research sheds light on the vulnerability of AMD “Zen” platforms to Rowhammer attacks on DDR4 and DDR5 memory.

While Rowhammer attacks are not a novel concern, the researchers at ETH Zurich have demonstrated the ability to perform bit flips using Rowhammer on a DDR5 device for the first time. AMD is currently evaluating these findings and will provide an update once their assessment is complete.

It’s important to note that susceptibility to Rowhammer attacks can vary depending on factors such as the specific DRAM device, vendor, technology, and system settings. To determine if your system is vulnerable to this new variant of Rowhammer, AMD advises reaching out to your DRAM or system manufacturer for further guidance.

In light of these findings, AMD recommends implementing existing DRAM mitigations to protect against Rowhammer-style attacks. These include utilizing DRAM with Error Correcting Codes (ECC), employing memory refresh rates above 1x, and disabling Memory Burst/Postponed Refresh. Additionally, AMD CPUs with memory controllers that support a Maximum Activate Count (Mac) can provide an added layer of protection (applicable to DDR4) with processors like the 1st Gen AMD EPYC (codenamed “Naples”), 2nd Gen AMD EPYC (codenamed “Rome”), and 3rd Gen AMD EPYC (codenamed “Milan”). For DDR5, AMD CPUs with memory controllers supporting Refresh Management (RFM) like the upcoming 4th Gen AMD EPYC (codenamed “Genoa”) offer enhanced security.

AMD would like to express its gratitude to the researchers at ETH Zurich, including Patrick Jattke, Max Wipfli, Flavien Solt, Michele Marazzi, Matej Boleskei, and Kaveh Razavi, for their diligent work in reporting these findings and engaging in coordinated vulnerability disclosure. This collaborative effort is crucial in addressing security concerns and ensuring the continued safety of AMD platforms.

Background Information

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About AMD: AMD, a large player in the semiconductor industry is known for its powerful processors and graphic solutions, AMD has consistently pushed the boundaries of performance, efficiency, and user experience. With a customer-centric approach, the company has cultivated a reputation for delivering high-performance solutions that cater to the needs of gamers, professionals, and general users. AMD's Ryzen series of processors have redefined the landscape of desktop and laptop computing, offering impressive multi-core performance and competitive pricing that has challenged the dominance of its competitors. Complementing its processor expertise, AMD's Radeon graphics cards have also earned accolades for their efficiency and exceptional graphical capabilities, making them a favored choice among gamers and content creators. The company's commitment to innovation and technology continues to shape the client computing landscape, providing users with powerful tools to fuel their digital endeavors.

  

Technology Explained

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DDR4: DDR4 is a generation of Double Data Rate (DDR) dynamic random access memory (RAM) technology. It is a type of RAM that utilizes a higher clock frequency and is more power-efficient than its predecessors. As a result, it is capable of processing data more quickly than other RAM in the computer industry. Its increased speed and power efficiency are beneficial for applications such as gaming, rendering, and machine learning. It is designed for high-performance computing and enables faster access to stored information, resulting in better overall performance for the user. Furthermore, because of its low voltage requirements it requires less power consumption, making it an attractive option for many computer systems. DDR4 is set to become the primary RAM in most computer systems as the industry transitions away from its predecessors.

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DDR5: DDR5 (Double Data Rate 5) is the next generation of memory technology for the computer industry. It is a modern day improvement on earlier DDR technologies, with faster speeds, greater bandwidth and higher capacities. DDR5 enables higher resolution, seamless gaming experiences and faster data transfer rates, making it an ideal choice for high-performance computing and 4K gaming. With its greater RAM compatibility, DDR5 provides faster buffering times and raised clock speeds, giving users an improved overall work system. DDR5 is also optimized for multi-tasking, allowing users to multitask without experiencing a significant drop in performance, increasing the productivity of digital tasks. As an ever-evolving technology, DDR5 is paving the way for the computer industry into a new and powerful era.

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EPYC: EPYC is a technology designed by computer chip manufacturer AMD for use in the server and data center industry. It was introduced in June 2017 and features an innovative design to improve performance and power efficiency. EPYC processor technology is based on an innovative 14nm processor architecture, allowing up to 32 high-performance cores in a single socket. This allows for more efficient processing power, increased memory bandwidth, and greater compute density. EPYC is now widely used in the data center and cloud computing industry and provides benefits such as greater scalability, increased resource efficiency, and advanced virtualization capabilities. Additionally, EPYC technology is used in data intensive servers like server farms, gaming, and virtualization platforms. EPYC ensures that even with large deployments in multi-processor environments, power consumption and performance levels are optimized to ensure maximum efficiency.