I've got this issue on
```
# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.2 LTS
Release: 20.04
Codename: focal
# uname -a
Linux ultima 5.4.0-80-generic #90-Ubuntu SMP Fri Jul 9 22:49:44 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
```
The message is
```
kernel:[864004.039343] unregister_netdevice: waiting for lo to become free. Usage count = 1
```
I've got this issue on
```
# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.2 LTS
Release: 20.04
Codename: focal
# uname -a
Linux ultima 5.4.0-80-generic #90-Ubuntu SMP Fri Jul 9 22:49:44 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
```
The message is
``` [864004. 039343] unregister_ netdevice: waiting for lo to become free. Usage count = 1
kernel:
```