Hi there, OK, for me it’s nothing to do with the docker socket file itself, or the permissions or the owner or the group.
I added:
in each ‘service’ in a docker-compose.yaml file and the docker services started again.
And I added --security-opt apparmor=unconfined on the command line for docker run commands and everything works again as it should.
What changed: Debian 12 → 13 upgrade.
Why did I go down this route of adding the security-opt?
Because dmesg was saying stuff like this: [Sat Sep 27 17:14:03 2025] audit: type=1400 audit(1758986043.532:1869722223): apparmor=“DENIED” operation=“create” class=“net” info=“failed protocol match” error=-13 profile=“docker-default” pid=18 2641 comm=“su-exec” family=“unix” sock_type=“stream” protocol=0 requested=“create” denied=“create” addr=none as pointed out by yourself.