wsl-enable-usb-storage.sh

#!/bin/bash

export WSLKERNEL=`uname -a | cut -d " "  -f3 | cut -d "-" -f1`
export CHECKOUT_DIR=`linux-msft-wsl-$WSLKERNEL`

git clone https://github.com/microsoft/WSL2-Linux-Kernel.git --depth=1 -b $CHECKOUT_DIR
cd $WSLKERNEL
sudo  make -j$(nproc) KCONFIG_CONFIG=Microsoft/config-wsl CONFIG_USB_STORAGE=m CONFIG_USB_UAS=m
sudo  make -j$(nproc) KCONFIG_CONFIG=Microsoft/config-wsl CONFIG_USB_STORAGE=m CONFIG_USB_UAS=m modules
sudo  make -j$(nproc) KCONFIG_CONFIG=Microsoft/config-wsl CONFIG_USB_STORAGE=m CONFIG_USB_UAS=m modules_install
cp arch/x86/boot/bzImage wsl-$WSLKERNEL  
echo "Copy the above to the root of your  USERPROFILE on the Windows sdie then Add in the [wsl] section of your .wslconfig the following, doubling all
kernel=c:\\users\\username\\wsl-$WSLKERNEL

Then run wsl --shutdown from Windows, wait a minut or so and star wsl again. Once you have your usb device passed you should see the storage device if not, try on the wsl side: modprobe usb-storage; modprobe uas"

@Komorebi-E what's strange: to make the USB mass storage actually work with USBIPD and that custom kernel, I have to execute modprobe vhci_hcd in WSL2, which succeeds.
(and docker is failing)

Install build-essential flex bison libssl-dev libelf-dev libncurses5-dev git bc pahole to get the dependencies.

This worked for me.