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

MIT CSAIL researchers Daniël Trujillo and Mengjia Yan unveiled INTERRUPT INJECTION, a new attack that bypasses Spectre v2 defenses on Intel and AMD CPUs. An unprivileged Linux program times a hardware interrupt to re-poison the branch predictor after mitigation runs. On an AMD Zen 2 machine with Linux 6.14 and all default mitigations enabled, the attack succeeded.