Trying to take advantage of the kernel from 6.7 onwards adding support for the mounting of binfmt_misc inside unprivileged containers. The purpose is to run box86/box64 on an aarch64 system to emulate amd64.
However, systemd-binfmt complains of “permission denied”.
root@ampx64:~# systemctl status systemd-binfmt.service
× systemd-binfmt.service - Set Up Additional Binary Formats
Loaded: loaded (/usr/lib/systemd/system/systemd-binfmt.service; static)
Active: failed (Result: exit-code) since Sun 2024-04-28 14:29:17 AEST; 24min ago
Docs: man:systemd-binfmt.service(8)
man:binfmt.d(5)
https://docs.kernel.org/admin-guide/binfmt-misc.html
https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
Process: 2337 ExecStart=/usr/lib/systemd/systemd-binfmt (code=exited, status=1/FAILURE)
Main PID: 2337 (code=exited, status=1/FAILURE)
CPU: 10ms
Apr 28 14:29:17 ampx64 systemd[1]: Starting systemd-binfmt.service - Set Up Additional Binary Formats...
Apr 28 14:29:17 ampx64 systemd-binfmt[2337]: Failed to flush binfmt_misc rules, ignoring: Permission denied
Apr 28 14:29:17 ampx64 systemd-binfmt[2337]: /etc/binfmt.d/box64.conf:2: Failed to add binary format 'box64': Permission denied
Apr 28 14:29:17 ampx64 systemd-binfmt[2337]: /etc/binfmt.d/box86.conf:2: Failed to add binary format 'x86': Permission denied
Apr 28 14:29:17 ampx64 systemd-binfmt[2337]: /usr/lib/binfmt.d/python3.10.conf:1: Failed to add binary format 'python3.10': Permission denied
Apr 28 14:29:17 ampx64 systemd-binfmt[2337]: /usr/lib/binfmt.d/python3.12.conf:1: Failed to add binary format 'python3.12': Permission denied
Apr 28 14:29:17 ampx64 systemd[1]: systemd-binfmt.service: Main process exited, code=exited, status=1/FAILURE
Apr 28 14:29:17 ampx64 systemd[1]: systemd-binfmt.service: Failed with result 'exit-code'.
Apr 28 14:29:17 ampx64 systemd[1]: Failed to start systemd-binfmt.service - Set Up Additional Binary Formats.
Relevant info:
root@ampx64:~# uname -a
Linux ampx64 6.8.0-31-generic #31-Ubuntu SMP PREEMPT_DYNAMIC Sat Apr 20 02:32:42 UTC 2024 aarch64 aarch64 aarch64 GNU/Linux
root@ampx64:~# mount | grep binfmt
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,relatime)
root@ampx64:~# ls -la /proc/sys/fs/binfmt_misc/
total 0
drwxr-xr-x 2 root root 0 Apr 28 12:49 .
dr-xr-xr-x 1 nobody nogroup 0 Apr 28 12:49 ..
--w------- 1 root root 0 Apr 28 12:49 register
-rw-r--r-- 1 root root 0 Apr 28 12:49 status
root@ampx64:~# ls -la /etc/binfmt.d/
total 18
drwxr-xr-x 2 root root 4 Apr 28 07:49 .
drwxr-xr-x 115 root root 219 Apr 28 12:48 ..
-rw-r--r-- 1 root root 212 Apr 28 07:45 box64.conf
-rw-r--r-- 1 root root 210 Feb 3 01:33 box86.conf
And on the host:
ubuntu@cloudvm:~$ incus version
Client version: 6.0.0
Server version: 6.0.0
Any hints appreciated.