Subject: Re: Bug#664064: linux-image-3.3.0-rc6-amd64: 4 messages every minute in syslog from netlink

From: Ben Hutchings <[email-masked]>
Date: Sun, 18 Mar 2012 03:15:54 +0000

[Please reply to all, not just to me.]

On Thu, 2012-03-15 at 19:01 +0100, Reinhard Karcher wrote:
> Am 15.03.2012 18:14, schrieb Ben Hutchings:
> > On Thu, 2012-03-15 at 13:00 +0100, Reinhard Karcher wrote:
> >> Package: linux-2.6
> >> Version: 3.3~rc6-1~experimental.1
> >> Severity: normal
> >>
> >> The kernel log says all!
> >> I have 2 laptops showing the messages, both amd64.
> >> One of them runs a 32-bit system in a VM with the linux-image-3.3.0-rc6-686-pae kernel,
> >> that does not have this problem.
> >> The amd64 kernel from unstable (3.2.0-2) does not show the messages.
> >>
> >> Reinhard
> >>
> >> -- Package-specific info:
> >> ** Version:
> >> Linux version 3.3.0-rc6-amd64 (Debian 3.3~rc6-1~experimental.1) ([email-masked]) (gcc version 4.6.3 (Debian 4.6.3-1) ) #1 SMP Mon Mar 5 20:53:11 UTC 2012
> >>
> >> ** Command line:
> >> BOOT_IMAGE=/boot/vmlinuz-3.3.0-rc6-amd64 root=UUID=9bb56ba6-3117-47d6-b07c-2cca477643e9 ro quiet cgroup_enable=memory
> >>
> >> ** Not tainted
> >>
> >> ** Kernel log:
> >> [46368.760279] netlink: 140 bytes leftover after parsing attributes.
[...]
> The same system, but using the kernel from unstable and not from 
> experimental does not show the messages, so they are related to the 
> experimetal kernel.
> Does this tell anything?
> root@apollon:/home/reinhard# lsof | grep netlink
> dnsmasq   1862     dnsmasq  mem       REG                8,2     24712 
>    7391593 /usr/lib/libnfnetlink.so.0.2.0 
> 
> kded4     2839    reinhard  mem       REG                8,2     12272 
>    9683029 /usr/lib/ntrack/modules/ntrack-rtnetlink.so 

Well, netlink is a protocol, not a file.  But most programs using
netlink will probably use a library with 'netlink' or 'libnl' in its
name, so this does provide some clues.

[later:]
> Some further investigation showed that the 1st occurrence of the message 
> is related to the start of KDE. After stopping X (and KDE) there are no 
> new messages logged.

OK, so it's something running in your KDE session.  And the results you
got from lsof suggest that it's some kind of network monitor that's
hosted by kded4, using the ntrack library
<https://launchpad.net/ntrack>.  I've never heard of this before.

ntrack appearently has the option to use either libnl or its own
built-in netlink protocol code, and is using the latter on your system.
If you install ntrack-module-libnl-0 and remove
ntrack-module-rtnetlink-0, does this fix the problem?

Ben.

-- 
Ben Hutchings
Larkinson's Law: All laws are basically false.