#1095554 snapd: kernel features are missing: dbus, network (proper kernel dependency missing?)

Package:
snapd
Source:
snapd
Description:
Daemon and tooling that enable snap packages
Submitter:
Ralf Bergs
Date:
2025-02-09 12:06:03 UTC
Severity:
normal
#1095554#5
Date:
2025-02-09 10:12:48 UTC
From:
To:
Dear Maintainer,

every time I reboot my machine I can spot the below error messages in
syslog:

snapd[975]: AppArmor status: apparmor is enabled but some kernel
features are missing: dbus, network
snapd[975]: backends.go:58: AppArmor status: apparmor is enabled but
some kernel features are missing: dbus, network

It seems that snapd needs some kernel features that are not present in
the currently running kernel. However, if that is the case, then it
should depend on a kernel that *has* these features.

Or am I misunderstanding anything?

Many thanks for listening.

Kind regards,

Ralf
#1095554#10
Date:
2025-02-09 10:55:06 UTC
From:
To:
Those are kernel-level apparmor features that depend on the evolution of apparmor in the upstream kernel. Snapd can detect all such features and actively looks for several, mostly related to UNIX sockets that allow DBus message mediation. The process of landing those features in the upstream kernel has been long and complicated and is AFAIK still ongoing.

Snapd detects absence of those features and gracefully degrades functionality. There is no way to depend on any kernel that would have all the features in Debian. At some point the upstream kernel release should have all of them so the messages will go away.

Best regards
ZK
#1095554#15
Date:
2025-02-09 10:55:06 UTC
From:
To:
Those are kernel-level apparmor features that depend on the evolution of apparmor in the upstream kernel. Snapd can detect all such features and actively looks for several, mostly related to UNIX sockets that allow DBus message mediation. The process of landing those features in the upstream kernel has been long and complicated and is AFAIK still ongoing.

Snapd detects absence of those features and gracefully degrades functionality. There is no way to depend on any kernel that would have all the features in Debian. At some point the upstream kernel release should have all of them so the messages will go away.

Best regards
ZK
#1095554#20
Date:
2025-02-09 11:41:55 UTC
From:
To:
Thanks, Zygmunt, for elaborating and providing some background. That
completely makes sense.
Would it not be possible to compile a kernel with all the required
features enabled, give the package a name following a specific scheme
(e.g. "linux-image-snap", you get the idea...), and then depend on or
"recommend" such kernels?

Or is it simply that the features may not even be available in a kernel
that has been approved for "stable?"

Thanks again.