This merge adds the kernel-side bits around mitigating AMD’s Speculative Return Address Stack (RAS) overflow vulnerability for Zen 3 and Zen 4. See this earlier article for details on this AMD INCEPTION disclosure.

Linus also merged the kernel changes around Intel Gather Data Sampling (GDS) / DOWNFALL. See the Intel DOWNFALL vulnerability overview for details on that issue affecting Skylake through Ice Lake / Tigerlake processors.

These security patches are now in Linux Git for the Linux 6.5 kernel while they should also be back-ported to the Linux stable series over the next few days.

Update: Six New Stable Linux Kernel Updates For Intel DOWNFALL & AMD INCEPTION

  • pnutzh4x0rOPAEnglish
    4·
    1 year ago

    Here is the Downfall writeup, which includes videos of extracting information in various situations.

    [A] GDS is highly practical. It tooks me 2 weeks to develop an end-to-end attack stealing encryption keys from OpenSSL. It only requires the attacker and victim to share the same physical processor core, which frequently happens on modern-day computers, implementing preemptive multitasking and simultaneous multithreading.

    [A] In addition to normal isolation boundaries e.g., virtual machines, processes, user-kernel isolation, Intel SGX is also affected. Intel SGX is a hardware security feature available on Intel CPUs to protect user’s data against all form of malicious software.