Unable to reproduce on many systems

I've been testing out a few of my systems, both work and personal. They seem unaffected. On the work Ubuntu 24.04 systems, both with AWS and generic kernels, I get ``` ~/dirtyfrag $ uname -r 6.17.0-1023-aws ~/dirtyfrag $ ./exp Password: su: Authentication failure ``` ``` ~$ uname -r 6.8.0-111-generic ~/dirtyfrag $ ./exp Password: su: Authentication failure ``` **Update:** I was able to make it work by logging out from my SSH session for a while and logging in back in - seems like once it fails it needs a moment to recover. Maybe it needs to get the `su` binary out of page cache? On my ArchLinux desktop: ``` max-p@desktop /t/dirtyfrag (master) [4]> uname -r 6.19.13-zen1-1-zen max-p@desktop /t/dirtyfrag (master)> ./exp dirtyfrag: failed (rc=4) ``` This one just never works, ran it dozens of times. Maybe `linux-zen` is not exploitable? In all those cases I can definitely see XFRM and RXRPC being loaded in dmesg, but the exploit fails. My other Arch machine with the regular `linux` package does appear exploitable: ``` max-p@nas ~/dirtyfrag (master)> uname -r 7.0.3-arch1-2 max-p@nas ~/dirtyfrag (master)> gcc -o exp -Wall -O0 -lutil exp.c max-p@nas ~/dirtyfrag (master)> ./exp [root@nas dirtyfrag]# ```