02 Feb 2023

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Xavier Mertens: This Blog Has 20 Years!

Twenty years ago… I decided to start a blog to share my thoughts! That's why I called it "/dev/random". How was the Internet twenty years ago? Well, they were good things and bad ones…

With the years, the blog content evolved, and I wrote a lot of technical stuff related to my job, experiences, tools, etc. Then, I had the opportunity to attend a lot of security conferences and started to write wrap-ups. With COVID, fewer conferences and no more reviews. For the last few months, I'm mainly writing diaries for the Internet Storm Center therefore, I publish less private stuff here, and just relay the content published on the ISC website. If you have read my stuff for a long time (or even if you are a newcomer), thank you very much!

A few stats about the site:

I know that these numbers might seem low for many of you but I'm proud of them!

The post This Blog Has 20 Years! appeared first on /dev/random.

02 Feb 2023 8:19pm GMT

Koen Vervloesem: How to stop brltty from claiming your USB UART interface on Linux

Today I wanted to program an ESP32 development board, the ESP-Pico-Kit v4, but when I connected it to my computer's USB port, the serial connection didn't appear in Linux. Suspecting a hardware issue, I tried another ESP32 board, the ESP32-DevKitC v4, but this didn't appear either, so then I tried another one, a NodeMCU ESP8266 board, which had the same problem. Time to investigate...

The dmesg output looked suspicious:

[14965.786079] usb 1-1: new full-speed USB device number 5 using xhci_hcd
[14965.939902] usb 1-1: New USB device found, idVendor=10c4, idProduct=ea60, bcdDevice= 1.00
[14965.939915] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[14965.939920] usb 1-1: Product: CP2102 USB to UART Bridge Controller
[14965.939925] usb 1-1: Manufacturer: Silicon Labs
[14965.939929] usb 1-1: SerialNumber: 0001
[14966.023629] usbcore: registered new interface driver usbserial_generic
[14966.023646] usbserial: USB Serial support registered for generic
[14966.026835] usbcore: registered new interface driver cp210x
[14966.026849] usbserial: USB Serial support registered for cp210x
[14966.026881] cp210x 1-1:1.0: cp210x converter detected
[14966.031460] usb 1-1: cp210x converter now attached to ttyUSB0
[14966.090714] input: PC Speaker as /devices/platform/pcspkr/input/input18
[14966.613388] input: BRLTTY 6.4 Linux Screen Driver Keyboard as /devices/virtual/input/input19
[14966.752131] usb 1-1: usbfs: interface 0 claimed by cp210x while 'brltty' sets config #1
[14966.753382] cp210x ttyUSB0: cp210x converter now disconnected from ttyUSB0
[14966.754671] cp210x 1-1:1.0: device disconnected

So the ESP32 board, with a Silicon Labs, CP2102 USB to UART controller chip, was recognized, and it was attached to the /dev/ttyUSB0 device, as it should normally do. But then suddenly the brltty command intervened and disconnected the serial device.

I looked up what brltty is doing, and apparently this is a system daemon that provides access to the console for a blind person using a braille display. When looking into the contents of the package on my Ubuntu 22.04 system (with dpkg -L brltty), I saw a udev rules file, so I grepped for the product ID of my USB device in the file:

$ grep ea60 /lib/udev/rules.d/85-brltty.rules
ENV{PRODUCT}=="10c4/ea60/*", ATTRS{manufacturer}=="Silicon Labs", ENV{BRLTTY_BRAILLE_DRIVER}="sk", GOTO="brltty_usb_run"

Looking at the context, this file shows:

# Device: 10C4:EA60
# Generic Identifier
# Vendor: Cygnal Integrated Products, Inc.
# Product: CP210x UART Bridge / myAVR mySmartUSB light
# BrailleMemo [Pocket]
# Seika [Braille Display]
ENV{PRODUCT}=="10c4/ea60/*", ATTRS{manufacturer}=="Silicon Labs", ENV{BRLTTY_BRAILLE_DRIVER}="sk", GOTO="brltty_usb_run"

So apparently there's a Braille display with the same CP210x USB to UART controller as a lot of microcontroller development boards have. And because this udev rule claims the interface for the brltty daemon, UART communication with all these development boards isn't possible anymore.

As I'm not using these Braille displays, the fix for me was easy: just find the systemd unit that loads these rules, mask and stop it.

$ systemctl list-units | grep brltty
brltty-udev.service loaded active running Braille Device Support
$ sudo systemctl mask brltty-udev.service
Created symlink /etc/systemd/system/brltty-udev.service → /dev/null.
$ sudo systemctl stop brltty-udev.service

After this, I was able to use the serial interface again on all my development boards.

02 Feb 2023 8:19pm GMT

Frederic Descamps: MySQL 8.0.32: thank you for the contributions

The latest MySQL release has been published on January 17th, 2023. MySQL 8.0.32 contains some new features and bug fixes. As usual, it also contains contributions from our great MySQL Community.

I would like to thank all contributors on behalf of the entire Oracle MySQL team !

MySQL 8.0.32 contains patches from Facebook/Meta, Alexander Reinert, Luke Weber, Vilnis Termanis, Naoki Someya, Maxim Masiutin, Casa Zhang from Tencent, Jared Lundell, Zhe Huang, Rahul Malik from Percona, Andrey Turbanov, Dimitry Kudryavtsev, Marcelo Altmann from Percona, Sander van de Graaf, Kamil Holubicki from Percona, Laurynas Biveinis, Seongman Yang, Yamasaki Tadashi, Octavio Valle, Zhao Rong, Henning Pöttker, Gabrielle Gervasi and Nico Pay.

Here is the list of the above contributions and related bugs, we can see that for this release, our connectors got several contributions, always a good sign of their increasing popularity.

We can also notice the return of a major contributor: Laurynas Biveinis!


Connector / NET

Connector / Python

Connector / J

Connector / C++

Clients & API


InnoDB and Clone


If you have patches and you also want to be part of the MySQL Contributors, it's easy, you can send Pull Requests from MySQL's GitHub repositories or send your patches on Bugs MySQL (signing the Oracle Contributor Agreement is required).

Thank you again to all our contributors !

02 Feb 2023 8:19pm GMT