Comment by peri-cl
5 days ago
The OP says they discovered this on a Zen 2, which is not covered by that bulletin (?)
[edit to add]: Also, the bulletin is solely about RDSEED zeros, whereas the OP is also reporting RDRAND zeroes.
5 days ago
The OP says they discovered this on a Zen 2, which is not covered by that bulletin (?)
[edit to add]: Also, the bulletin is solely about RDSEED zeros, whereas the OP is also reporting RDRAND zeroes.
Older AMD processors had issues as well:
https://github.com/systemd/systemd/pull/12536/commits/1c53d4...
That one's insidious!
I found the thread about it,
https://news.ycombinator.com/item?id=19848953
Yikes at this: "I am so glad I resisted pressure from engineers working at Intel to let /dev/random in Linux rely blindly on the output of the RDRAND instructure." -Theodore Ts'o (2013)
Why does systemd use architecture-specific instructions rather than using the kernel-provided random interface in the first place?
It was removed later https://github.com/systemd/systemd/commit/ffa047a03e4c5f6bd3...