Explore a groundbreaking Black Hat conference talk unveiling a novel exploit capable of bypassing advanced rowhammer defenses. Delve into the intricacies of this 40-minute presentation, which demonstrates how an unprivileged user application can gain root and kernel privileges. Learn about the exploit's stealthy and efficient nature compared to existing rowhammer techniques. Examine key topics including memory access, raw ham attacks, performance counters, tab ownership, privilege escalation, exploitable buffers, and potential limitations. Gain insights from security experts Yueqiang Cheng, Zhi Zhang, Surya Nepal, and Zhi Wang as they discuss the implications of this exploit and potential countermeasures.