3mo ago

USB Tethering from Android just stopped working

Upon upgrading from Fedora 41 to 42, I noticed that the USB tethering just doesn't work

networkctl recognizes the device as "wwan" now, instead of "ether". If I load up a previous kernel, USB tethering works normally.

This seems to be a change in the kernel, and probably won't be reverted in the future. What do I do?

More detail in this comment

You know what? Fuck this. I just backed my shit up and installed Debian. Still, please try to look into this, this could be a problem for many others

13 comments

I've been working on a phone tethering router so might have some insight here for you. Android can use CDC or RNDIS to tether. It depends on your phone which ones gonna be used. Try to figure out which one its using (can do this by watching logs when plugging in usb usually itll say there which type of device is connecting). When i was doing the router i had to make sure cdc_ether and rndis_host kernel modules were both loaded to ensure compatibility. It might be as simple as manually loading a module in the new kernel version. Although I'm not exactly sure how it'll work on fedora i was doing this all on OPNsense.
What i was doing was tethering the phone to a router (old thinkpad running router OS) then passing that connection on to its network and connecting to the Access Point on the network with my laptop. I still havent fully worked out the kinks yet but its going pretty well. Sorry i can't be more specific for your case, but hopefully it gives you some terms you can use to google more effectively at the least.
- Seems to be rndis for me.
  
  try to look up how to enable rndis in fedora manually and try it. Might work. Or you might need to download something too.
I have a similar problem on OpenSUSE. The solution for me is running modprobe rndis_host.
- This did nothing. I don't notice any change at all
This is why I try to wait at least a week to for release upgrades.
- Is week enough?
  
  It's my minimum. It's usually been fine in the past. I've gone from a beta to full release and been fine. But the last few years ya, I try to wait at least a week, up to about a month. I do have other PCs or VMs I'll test a bit more with before pulling the trigger on my main machine.
You're not alone in this:
https://discussion.fedoraproject.org/t/usb-tethering-stopped-working-after-f42-update/148809
https://discussion.fedoraproject.org/t/fedora-42-tethering-from-my-phone-stopped-working-after-upgrade-device-recognized-as-wwan/148927
https://bugzilla.kernel.org/show_bug.cgi?id=220002
https://lore.kernel.org/all/e0df2d85-1296-4317-b717-bd757e3ab928@heusel.eu/
When Debian upgrades to this kernel version you might run into the issue again. Unless there is a fix deployed before then.
- By that time, I don't think I'll have to rely on USB tethering anymore. Plus the problem might reach the right ears and get fixed by then, as you said.

13 comments