It might be senility or I suddenly can not understand English, so I will just
copy and paste here..
The bounds check bypass has also been shown to read kernel memory on Intel
and AMD processors. Importantly, this does not work on AMD processors in
default configurations. The proof-of-concept requires BPF JIT to be manually
enabled in the Linux kernel for AMD processors. (It is not, by default.) The
tested Intel processor was vulnerable independent of the BPF JIT setting.
https://www.techrepublic.com/article/massive-intel-cpu-flaw-understanding-the-technical-details-of-meltdown-and-spectre/
And this is from the goobles zero study directly:
A PoC for variant 1 that, when running with normal user privileges under a
modern Linux kernel with a distro-standard config, can perform arbitrary
reads in a 4GiB range [3] in kernel virtual memory on the Intel Haswell Xeon
CPU. If the kernel's BPF JIT is enabled (non-default configuration), it also
works on the AMD PRO CPU.
And yep, the variant one is -> Variant 1: bounds check bypass (CVE-2017-5753)
That is the only one exploit AMD says it can represent a problem for their
CPUs, meltdown does not affect it due to architecture differences and the
second variant according to AMD has "near zero risk of exploitation".
If so, I am a happy guy :)
Well, in each case it would appear that exploiting spectre is quite tough and
to my understanding nowhere near as grave as meltdown.
Imagine how nice must it be to have a ready cross-platform exploit for every
single Intel CPU ever made for 20 years.. Not that I wish to imply that Intel
did this on purpose or to gain single core performance advantage over AMD. :P
