Will Rowhammer Ever Be in the Rear View?

David Blankenbeckler

"Will Rowhammer ever be in the rear view? When I first started working on Rowhammer in 2012, I would have never guessed that I'd still be working on Rowhammer in 2023!" --- This talk summarizes the history of Rowhammer from the very beginning, when Intel encountered it in 2011, to date. We'll begin with an inside look at how Rowhammer was identified and debugged. We will discuss the mitigations Intel and the industry put into place for DDR3 and early DDR4 devices. We then highlight existing defenses by delving into recent mitigations for DDR5 and LPDDR5 that are part of the JEDEC standard. We focus on refresh management (RFM) and its derivatives -- namely adaptive RFM and directed RFM. We will discuss more defensible approaches that are being investigated for future memory technologies, whereby the DRAM perfectly tracks row activations. We provide an overview of the concept and briefly touch on its fundamental challenges. The talk concludes with a short overview of emerging memory security challenges and actions we, as a security community, must take to address them.

Bio: David Blankenbeckler has worked in the computer industry for 32 years and at Intel for the last 28 years. For much of his career, David worked on validation of I/O and memory buses, including PCI Express Gen 1, 2, 3, and 4 and DDR2, DDR3, DDR4, and DDR5. When Intel first discovered Rowhammer in 2012, David was asked to lead the Intel-wide cross-functional team to drive mitigations for Intel products. Each time the issue has reappeared, David has ramped up a technical team to address. Once it was clear that DDR4 was not Rowhammer free, David decided to focus exclusively on memory security. He now leads a memory security team, driving mitigation actions to memory security issues, doing memory security research, and proactively driving memory security improvements for Intel products. When not pondering why Rowhammer is still around, David likes to spend his time sailing, running, mountain biking and spending time with his family.

Based on the Researcher theme