New Interrupt Injection Attack Can Bypass Spectre v2 Defenses on Intel and AMD CPUs

Researchers at MIT have discovered a new vulnerability, dubbed INTERRUPT INJECTION, that allows an unprivileged Linux program to bypass Spectre v2 defenses on Intel and AMD CPUs. By precisely timing a hardware interrupt, attackers can re-poison a processor's branch predictor, leading to data leakage. While Intel does not consider a mitigation necessary, AMD has released a bulletin and a kernel patch to address the issue. The vulnerability exploits a window of time between branch prediction neutralization and use, and requires careful manipulation of interrupt handling to achieve a successful attack.