New StackRot Linux kernel flaw allows privilege escalation

5 comments

People who can find such bugs have always amazed me. The understanding of the kernel required seems so impossibly vast.
Specifically, the weak spot is in "maple tree," a new data structure system for VMAs introduced in Linux kernel 6.1 that replaced the "red-black trees" and relied on the read-copy-update (RCU) mechanism.

Maple Tree also recently caused intermittent failures in some of my CPU-intensive tasks, in such an obscure way that I only found out by dumb luck that it was a kernel bug. I expect it will be great eventually, but it's feeling pretty rough at the moment. I'm thinking this code should have had more testing and maturing before going mainline.
- Damn. If the Maple Tree code is bugging out under CPU-intensive tasks, that would explain a lot about how my system's been behaving since I moved to 6.1. Thanks for the heads-up, and I guess I should compile another new kernel.
- Rcu is mostly broken, it's been a nightmare for a decade, building on top of that seems suicidal.
  
  I know rcu failures are just symptoms of other issues, but building on top of it doesn't help matters.