$ uname -r
6.8.0-31-generic
ubuntu@ubuntu-noble:~$ ls -1 /proc/sys/kernel/unprivileged_userns_*
/proc/sys/kernel/unprivileged_userns_apparmor_policy
/proc/sys/kernel/unprivileged_userns_clone
Have you checked dmesg for apparmor denials? You could also disable apparmor to see if that makes a difference (add 'apparmor=0' to the kernel commandline).
Hm. I see that knob:
$ uname -r ubuntu- noble:~ $ ls -1 /proc/sys/ kernel/ unprivileged_ userns_ * kernel/ unprivileged_ userns_ apparmor_ policy kernel/ unprivileged_ userns_ clone
6.8.0-31-generic
ubuntu@
/proc/sys/
/proc/sys/
Have you checked dmesg for apparmor denials? You could also disable apparmor to see if that makes a difference (add 'apparmor=0' to the kernel commandline).