Linux Patched For New Intel "MMIO Stale Data" Vulnerabilities

[phoronix]

Phoronix: Linux Patched For New Intel "MMIO Stale Data" Vulnerabilities

In addition to the Hertzbleed frequency scaling side-channel attack being made public today as part of "Patch Tuesday" and affecting both Intel and AMD CPUs, Intel is additionally disclosing a set of "MMIO Stale Data" vulnerabilities. The Linux kernel has already been patched for these new vulnerabilities affecting multiple generations of Intel CPUs from Rocket Lake back to Haswell X and Skylake...

https://www.phoronix.com/scan.php?page=news_item&px=MMIO-Stale-Data-Vulnerabilities

[Lbibass]

oh boy!

[mb_q]

For hertzbleed, Intel asked for embargo extension with no particular reason. And, by a pure coincidence, we have news about this actual Intel microcode bug diluted by the news about novel exploitation of general side-channels.

[ms178]

One more flag to add to the command line...

[OpenSourceAnarchist]

So just to be clear,

mitigations=off

is no longer the only kernel parameter necessary to fully disable all mitigations (on hardware where it is safe to do so, like offline computers)? Or is

mmio_stale_data=off

now also mandatory for this?

[numacross]

So just to be clear,

mitigations=off

is no longer the only kernel parameter necessary to fully disable all mitigations (on hardware where it is safe to do so, like offline computers)? Or is

mmio_stale_data=off

now also mandatory for this?

mitigations=off

disables all mitigations that can be disabled including this one, while

mmio_stale_data=off

disables only this specific one.

Basically you can choose which mitigations you want to disable (or configure since some have more parameters than just "off") by using their specific kernel parameters.

[Vorpal]

I'd like to see Phoronix do the usual benchmarks with regards to this one.

[CTTY]

Is qemu/kvm affected?