Проблема после обновления 18.04 - > 18,10

Вчера я обновил Ubuntu 18.04. до 18.10. При обновлении были некоторые ошибки / предупреждения, которые я не мог вспомнить или скопировать. Тем не менее, если я сейчас apt update & apt upgrade, я получаю следующую ошибку:

The following packages will be upgraded:
  linux-image-4.18.0-17-generic linux-modules-4.18.0-17-generic
2 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/21.6 MB of archives.
After this operation, 1,136 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
(Reading database ... 321219 files and directories currently installed.)
Preparing to unpack .../linux-modules-4.18.0-17-generic_4.18.0-17.18_amd64.deb ...
Unpacking linux-modules-4.18.0-17-generic (4.18.0-17.18) over (4.18.0-17.18~18.04.1) ...
dpkg: error processing archive /var/cache/apt/archives/linux-modules-4.18.0-17-generic_4.18.0-17.18_amd64.deb (--unpack):
 unable to make backup link of './boot/System.map-4.18.0-17-generic' before installing new version: Operation not permitted
dpkg-deb: error: paste subprocess was killed by signal (Broken pipe)
Preparing to unpack .../linux-image-4.18.0-17-generic_4.18.0-17.18_amd64.deb ...
Unpacking linux-image-4.18.0-17-generic (4.18.0-17.18) over (4.18.0-17.18~18.04.1) ...
dpkg: error processing archive /var/cache/apt/archives/linux-image-4.18.0-17-generic_4.18.0-17.18_amd64.deb (--unpack):
 unable to make backup link of './boot/vmlinuz-4.18.0-17-generic' before installing new version: Operation not permitted
Errors were encountered while processing:
 /var/cache/apt/archives/linux-modules-4.18.0-17-generic_4.18.0-17.18_amd64.deb
 /var/cache/apt/archives/linux-image-4.18.0-17-generic_4.18.0-17.18_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

a uname -a показывает мне, что установлено новое ядро:

Linux 4.18.0-20-generic #21-Ubuntu SMP Mon May 6 18:45:52 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Поэтому мне интересно, почему apt пытается установить пакеты 4.18.0-17 ...

Есть какие-нибудь мысли?

Редактировать: ничего необычного в sources.list

root@pumpkin:~# cat /etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu/ cosmic main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu/ cosmic-security main restricted universe multiverse

# deb https://packages.grafana.com/oss/deb stable main
# deb-src https://packages.grafana.com/oss/deb stable main