Realtek Wifi Dongle RTL8188EUS

[drjdmartin]

Hi,

I'm running Ubuntu 20.10. I have a realtek wifi dongle, lsusb:

Bus 003 Device 002: ID 0bda:8179 Realtek Semiconductor Corp. RTL8188EUS 802.11n Wireless Network Adapter

It didn't work out of the box (no wifi option in gui), so I blacklisted the in-built r8188eu and tried to install the one from lwfinger at https://github.com/lwfinger/rtl8188eu. Now wifi is an option in the gui but I see no networks. sudo dmesg | grep 8188:

[    4.609546] 8188eu: loading out-of-tree module taints kernel.
[    4.609796] 8188eu: module verification failed: signature and/or required key missing - tainting kernel
[    4.611947] Chip Version Info: CHIP_8188E_Normal_Chip_TSMC_UNKNOWN_CUT(10)_1T1R_RomVer(0)
[    4.646007] usbcore: registered new interface driver r8188eu
[    5.077610] r8188eu 3-1:1.0 wlx28f366942c60: renamed from wlan0
[   10.775359] R8188EU: Firmware Version 11, SubVersion 1, Signature 0x88e1
[   12.561851] R8188EU: INFO indicate disassoc

So I thought the module signing was probably the problem, but the confusion is that I'm not running secure boot so I can't sign the modules on my system, and surely module signing shouldn't be a problem in the first place? I thought maybe it would work if I installed via DKMS so I wrote a simple dkms.conf and installed the lwfinger driver that way instead. But I still have this error message. Here is the output of iwconfig:

lo        no wireless extensions.


eno1      no wireless extensions.


wlx28f366942c60  unassociated  ESSID:""  Nickname:"<WIFI@REALTEK>"
          Mode:Managed  Frequency=2.412 GHz  Access Point: Not-Associated   
          Sensitivity:0/0  
          Retry:off   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=0/100  Signal level=0 dBm  Noise level=0 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

I've read around a bit and people are suggesting I'd have to recompile the kernel to turn off the module signing as I'm not on a UEFI system. Seems a bit drastic but I probably could have a stab. Do you think this error the source of the problem? Is there another way to fix it?

Thanks,

James

[drjdmartin]

I bought one of these which works out of the box and is cheap!

https://www.amazon.co.uk/Wireless-80...mputers&sr=1-5

Still interested in working out whether I could get the realtek ones working though.

[CelticWarrior]

https://askubuntu.com/questions/1170...n-ubuntu-18-04

[drjdmartin]

Thanks - but unfortunately that's basically what I already did (and the dkms instructions don't work anymore for that driver unless you do it yourself, which I did).

I have another realtek dongle using the RTL8188FU driver and that shows me networks on my Debian 10 install but won't connect. I'm forced to conclude realtek are a pain in the neck and not to be recommended!

Re the module signing issue suggested by my earlier post is this a bug in Ubuntu? As I say I am not using secure boot - I'm using bios boot and grub.

[slickymaster]

Thread moved to Networking & Wireless.

[drjdmartin]

Thanks for moving to the correct part of the forum. I think the following question is still open. From the dmesg output I think the module signing is preventing the lwfinger driver working. Is this a bug given my system is not secure boot? Is there any way around it given I can't sign the module on my system?

[    4.609546] 8188eu: loading out-of-tree module taints kernel.
[    4.609796] 8188eu: module verification failed: signature and/or required key missing - tainting kernel
[    4.611947] Chip Version Info: CHIP_8188E_Normal_Chip_TSMC_UNKNOWN_CUT(10)_1T1R_RomVer(0)
[    4.646007] usbcore: registered new interface driver r8188eu
[    5.077610] r8188eu 3-1:1.0 wlx28f366942c60: renamed from wlan0
[   10.775359] R8188EU: Firmware Version 11, SubVersion 1, Signature 0x88e1
[   12.561851] R8188EU: INFO indicate disassoc

[CelticWarrior]

Systems aren't "Secure Boot". Secure Boot is a UEFI feature that may or may not be enabled and if using an old BIOS system or a UEFI one in Legacy/CSM mode, not applicable.

I suggest you check which one you have and confirm that Secure Boot, if applicable, is really disabled.

[drjdmartin]

Thanks - so checking the BIOS it says UEFI enabled, legacy mode. This is on a Dell Optiplex 7010. So I think secure boot is at least disabled in the BIOS - is there anywhere else I should check?

When I tried to use mokutil to sign the 8188eu module as suggested in a few other posts I browsed I also got the error "EFI variables are not supported on this system". So I can't sign the module to fix the verification error.

[jeremy31]

How far away from the router are you and what manufacturer/model is the dongle? I have a small TP-Link one and it works on Ubuntu 18.04 with the 5.4 kernels but it doesn't have much range

The EFI variables not supported means that Secure Boot has nothing to do with the problem and the module doesn't need to be signed, if that was the issue, you would not see a wireless interface in iwconfig results as the kernel wouldn't load the driver

[chili555]

From the dmesg output I think the module signing is preventing the lwfinger driver working.

Not really. This message:

module verification failed: signature and/or required key missing - tainting kernel

...simply means that there was no provided verification that the driver is well and truly verified and free and open source. The driver code simply lacks a signature key. The kernel is no longer pure and verified open source.

Actually it is, you just can't prove it!

Secure boot, mokutil, etc. have nothing to say here.

Of greater interest is that you seem to have both the lwfinger 8188eu compiled version and the in-tree verified r8188eu version loaded. Verify:

lsmod | grep 8188

Two possibly conflicting drivers won't help here.

Let's look a bit further:

rfkill list all
dmesg | grep wlx
nmcli device wifi list

The EFI variables not supported means that Secure Boot has nothing to do with the problem and the module doesn't need to be signed, if that was the issue, you would not see a wireless interface in iwconfig results as the kernel wouldn't load the driver

Amen, my friend!!!