Dell TB18 dock ethernet corrupts data with hw checksum silently failing

Bug #1792574 reported by Matthias Haag on 2018-09-14
This bug affects 2 people
Affects Status Importance Assigned to Milestone
Dell Sputnik

Bug Description

It looks like TCP rx and tx checksum offloading is broken on the TB18 dock's ethernet adapter. For example downloading a large file such as the Ubuntu ISO, and then running an md5sum on it yields the incorrect md5sum. This is because
rx-checksumming: on
tx-checksumming: on
and both set to on by default.

Running sudo ethtool -K <TB18 eth device> tx off rx off, allows the download to complete correctly. This is very bad since this can cause very bad untrustworthy behavior.

This was conducted using an Dell Precision 7530 on Ubuntu 18.04.1 with kernel 4.15.0-34-generic.

Looks like the fix done with needs to be extended for the TB18 which has a different serial (see "lsusb -v" output):

Bus 004 Device 004: ID 0bda:8153 Realtek Semiconductor Corp.
Device Descriptor:
  bLength 18
  bDescriptorType 1
  bcdUSB 3.00
  bDeviceClass 0 (Defined at Interface level)
  bDeviceSubClass 0
  bDeviceProtocol 0
  bMaxPacketSize0 9
  idVendor 0x0bda Realtek Semiconductor Corp.
  idProduct 0x8153
  bcdDevice 30.11
  iManufacturer 1 Realtek
  iProduct 2 USB 10/100/1000 LAN
  iSerial 6 000002000000

This bug also affects

Matthias Haag (mahaag) on 2018-09-14
information type: Private Security → Public
description: updated
Kai-Heng Feng (kaihengfeng) wrote :

I think the serial is the same as LP: #1785780.

Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in ubuntu:
status: New → Confirmed
Matthias Haag (mahaag) wrote :

Looks like this bug was fixed with kernel version 4.15.0-36.39.

To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers