hang after using util badblocks

[Vladimir]

sudo badblocks -v /dev/sdb2 > badsectors.txt

after this command my computer hang, keyboard/mouse not working, no reaction, no ping in local network

only hardreset can help

sudo fdisk -l | grep /dev/sdb2
/dev/sdb2 206848 1422700543 1422493696 678,3G 7 HPFS/NTFS/exFAT

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: e2fsprogs 1.44.1-1ubuntu1.3
ProcVersionSignature: Ubuntu 5.4.0-48.52~18.04.1-generic 5.4.60
Uname: Linux 5.4.0-48-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.17
Architecture: amd64
CurrentDesktop: XFCE
Date: Tue Sep 29 16:00:24 2020
InstallationDate: Installed on 2020-03-09 (204 days ago)
InstallationMedia: Xubuntu 18.04.4 LTS "Bionic Beaver" - Release amd64 (20200203.1)
SourcePackage: e2fsprogs
UpgradeStatus: No upgrade log present (probably fresh install)

[Theodore Ts'o (tytso)]

If the computer is hanging as you describe, this is a kernel bug, possibly exacerbated by a hardware bug. It isn't a userspace bug; e2fsprogs is just reading from the block device. If that is causing the computer hang, it's by definition not a userspace bug.

So this needs to be a kernel investigation; can it be reliably reproduced? What kernel version is it? What is the hardware --- especially what kind of storage device, and how is it connected to the computer? If you hook up a serial console, are there any interesting kernel messages, including potentially device driver messages indicating some kind of hardware issue (e.g., media errors, etc.)

In any case, this needs to be redirected to the kernel, and if you have an LTS support contract, I'd suggest contacting Canonical's enterprise support to work the kernel issue.