Re: [PATCH v2] wifi: mac80211: fix the issue of NULL pointer access when deleting the virtual interface

[Óscar Alfonso Díaz]

Hello everyone, a member of the airgeddon team made a kernel
modification that seems to work. I’ve tested it on VMware and also on
bare metal with a 7.0.0-rc5 kernel, using both a Fenvi AX1800
(MT7921U) and an Alfa AWUS036AXML (MT7921AUN), and it appears to work
well. Deauthentication during VIF operation (evil twin attack) is now
working for MediaTek.

Everything is documented at this comment in the GitHub thread
(https://github.com/morrownr/USB-WiFi/issues/682#issuecomment-4167080451),
including the patch used. A patch that is modifying these three files
(tx.c, chan.c and ieee80211_i.h). Take a look at it  on the Github
thread please.

Regards.
--
Oscar

OpenPGP Key: DA9C60E9 ||
https://pgp.mit.edu/pks/lookup?op=get&search=0x79B17260DA9C60E9
4F74 B302 354D 817D DE38 0A43 79B1 7260 DA9C 60E9
--

El dom, 29 mar 2026 a las 23:55, Óscar Alfonso Díaz
(<oscar.alfonso.diaz@xxxxxxxxx>) escribió:
>
> Please review my latest messages in the GitHub thread.
> https://github.com/morrownr/USB-WiFi/issues/682
>
> There you’ll even find a link to a video I recorded so you can see
> that even on bare metal with Kali Linux installed natively, it still
> doesn’t work. It behaves exactly the same as it does in the VM.
>
> Here is the link
> https://www.dropbox.com/scl/fi/i6h8xbls5xkvae0pitrbg/video_2026-03-29_23-44-36.mp4?rlkey=jm48ly9tjwbhsi4aauml2auh9&dl=1
>
> Regards.
> --
> Oscar
>
> OpenPGP Key: DA9C60E9 ||
> https://pgp.mit.edu/pks/lookup?op=get&search=0x79B17260DA9C60E9
> 4F74 B302 354D 817D DE38 0A43 79B1 7260 DA9C 60E9
> --
>
> El jue, 26 mar 2026 a las 13:16, Óscar Alfonso Díaz
> (<oscar.alfonso.diaz@xxxxxxxxx>) escribió:
> >
> > Hi, in response to the three points:
> >
> > 1. VMware
> >
> > 2. This is the output of the lsusb command: "Bus 004 Device 002: ID
> > 0e8d:7961 MediaTek Inc. Wireless_Device". The adapter is very cheap,
> > it’s a Fenvi AX1800 (MT7921U), this one:
> > https://s.click.aliexpress.com/e/_okxhxNl . But as I said, the bug
> > also happens when using the Alfa AWUS036AXML (MT7921AUN).
> >
> > 3. I’m not sure about this right now. I’d say everything dies. I’ll
> > test that to see if SSH is still available (I don’t think so, but I’m
> > not 100% sure at the moment).
> >
> > Give me a few days. I’ll test this again over the weekend. I’ll also
> > run a test on bare metal (not in a VM). That said, like me, many
> > people use VMs for pentesting. So even if it works on bare metal,
> > which I’ll test this weekend, I think it would still be worth
> > investigating whether it can be fixed for VMs, since many people,
> > myself included, use them for work. If it works with other WiFi
> > adapters, it would be a big drawback if it didn’t work with MediaTek
> > adapters.
> >
> > I’ll also reply with a similar message in the thread.
> >
> > Thanks and regards.
> > --
> > Oscar
> >
> > OpenPGP Key: DA9C60E9 ||
> > https://pgp.mit.edu/pks/lookup?op=get&search=0x79B17260DA9C60E9
> > 4F74 B302 354D 817D DE38 0A43 79B1 7260 DA9C 60E9
> > --
> >
> > El jue, 26 mar 2026 a las 2:37, 傅继晗 (<fjhhz1997@xxxxxxxxx>) escribió:
> > >
> > > Hi Óscar,
> > >
> > > Lucid-Duck spent some time trying to reproduce your crash and wasn't able
> > > to trigger it. Here's a summary of what was tested:
> > >
> > > - Kali 2025.4 (kernel 6.18.12+kali-amd64) VM on QEMU/KVM, with my v2
> > >   patch applied
> > > - MT7921AU USB adapter, passthrough to VM
> > > - Full airgeddon evil twin flow: monitor VIF + hostapd AP + continuous
> > >   deauth via aireplay-ng
> > > - Also tested on bare metal Fedora 6.19.8 with the same adapter
> > >
> > > All tests were stable -- no crash, no dmesg errors, load stayed low. The
> > > deauth frames were confirmed sending for 30+ seconds under the v2 patch
> > > without issues.
> > >
> > > The one variable that couldn't be matched was the VM hypervisor.
> > > Lucid-Duck used QEMU/KVM, which handles USB passthrough at the kernel
> > > level (xHCI). If you're using VirtualBox or VMware, the USB passthrough
> > > path is quite different (userspace proxy), and that could potentially
> > > explain a total VM freeze that isn't a kernel panic.
> > >
> > > Could you please reply to Lucid-Duck directly on GitHub with the
> > > following information? Here's the link:
> > > https://github.com/morrownr/USB-WiFi/issues/682#issuecomment-4129198757
> > >
> > > 1. Which hypervisor are you using? (VirtualBox, VMware, QEMU/KVM, etc.)
> > > 2. Your exact USB adapter model and ID? (0e8d:7961 covers several
> > >    MT7921 variants)
> > > 3. If possible, try SSHing into the VM from the host while the display
> > >    is frozen -- if SSH still works, the issue is at the hypervisor/display
> > >    level, not the kernel.
> > >
> > > Thanks,
> > > 傅继晗