Comment on Encryption-breaking, password-leaking bug in many AMD CPUs could take months to fix
Jane2187@lemmy.world 11 months ago
How come branch prediction seems so vulnerable to exploits? Both spectre and meltdown were also caused by branch prediction not working quite right.
anlumo@feddit.de 11 months ago
It wasn’t branch prediction alone, it was the cache combined with branch prediction. The problem is that even discarded outcomes fill the cache with data. Those older vulnerabilities also had the problem that the access permissions check was done after the branch prediction. It’s probably too expensive to do when it’s not even clear yet whether the branch is going to be taken (that’s just speculation on my part though).