AMD Zen Safe RET Vulnerability Fixed in Linux Kernel 7.1.7

The Linux Kernel 7.1.7 release adds a critical security patch that hardens the Safe‑RET mitigation on AMD Zen 1‑through‑Zen 4 processors. The fix, authored by AMD engineer Borislav Petkov, prevents local attackers from injecting timed interrupts into the return‑stack protection sequence, a Spectre‑class flaw that could leak kernel memory at roughly 5.47 bytes per second.

The update contains only this security modification, making it a low‑risk upgrade for administrators of AMD‑based servers and desktops. It masks interrupts while the Safe‑RET sequence runs, ensuring the protection completes atomically. The patch is essential for systems that run untrusted local code, though it does not affect remote exploitation scenarios.