create net_namespace failed: Operation not permitted

[wholenewx]

Hello nlzy

I use nsproxy in a debian 10 and when I exec ./nsproxy -x xxx -x xxx ... , it shows :

nsproxy: create net_namespace failed: Operation not permitted
nsproxy: nsproxy can't run on this system.
The OS is debian 10

uname -r
4.19.0-25-amd64

Is there a dependency missing? Please help me, thanks

[nlzy]

Hi,

Unprivileged user-namespace is disabled by defualt on Debian 10.

Use this command to enable it, then nsproxy should work:

sudo sysctl -w kernel.unprivileged_userns_clone=1

This setting will be discarded on next reboot, use this command to save permanently:

echo 'kernel.unprivileged_userns_clone=1' | sudo tee /etc/sysctl.d/00-local-userns.conf

Or consider upgrading your OS to Debian 11+, which enable this feature by default, see
https://www.debian.org/releases/bullseye/amd64/release-notes/ch-information.en.html#linux-user-namespaces

[wholenewx]

Hi nlzy

Thanks a lot!

I had updated the kernel of Debian 10 from 4.19 to 5.10 and now nsproxy works good.

Next time, with your advice, no kernel update is needed, it's more convenient.

Thanks again!