qubes-qube-manager crashes due to python TypeError when changing netvm property

[Justasic]

Qubes OS release

Qubes OS 4.2

Brief summary

Hello!

I recently performed an update and tried to set the netvm of an already running disposable qube and the qube manager would crash with the following message:

Traceback (most recent call last):
  File "/usr/lib/python3.11/site-packages/qubesadmin/base.py", line 376, in __setattr__
    self.qubesd_call(
  File "/usr/lib/python3.11/site-packages/qubesadmin/base.py", line 76, in qubesd_call
    return self.app.qubesd_call(dest, method, arg, payload,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/site-packages/qubesadmin/app.py", line 789, in qubesd_call
    return self._parse_qubesd_response(return_data)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/site-packages/qubesadmin/base.py", line 89, in _parse_qubesd_response
    raise qubesadmin.exc.QubesDaemonAccessError(
qubesadmin.exc.QubesDaemonAccessError: Got empty response from qubesd. See journalctl in dom0 for details.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.11/site-packages/qubesmanager/qube_manager.py", line 929, in change_network
    info.vm.netvm = netvm_name
    ^^^^^^^^^^^^^
  File "/usr/lib/python3.11/site-packages/qubesadmin/base.py", line 383, in __setattr__
    raise qubesadmin.exc.QubesPropertyAccessError(key)
qubesadmin.exc.QubesPropertyAccessError: Failed to access 'netvm' property
Aborted (core dumped)

Reading the journalctl output of qubesd, I get the following exception:

Jan 21 17:04:44 dom0 qubesd[12640]: unhandled exception while calling src=b'dom0' meth=b'admin.vm.property.Set' dest=b'disp6189' arg=b'netvm' len(untrusted_payload)=16
Jan 21 17:04:44 dom0 qubesd[12640]: Traceback (most recent call last):
Jan 21 17:04:44 dom0 qubesd[12640]:   File "/usr/lib/python3.11/site-packages/qubes/api/__init__.py", line 297, in respond
Jan 21 17:04:44 dom0 qubesd[12640]:     response = await self.mgmt.execute(
Jan 21 17:04:44 dom0 qubesd[12640]:                ^^^^^^^^^^^^^^^^^^^^^^^^
Jan 21 17:04:44 dom0 qubesd[12640]:   File "/usr/lib/python3.11/site-packages/qubes/api/admin.py", line 267, in vm_property_set
Jan 21 17:04:44 dom0 qubesd[12640]:     return self._property_set(self.dest,
Jan 21 17:04:44 dom0 qubesd[12640]:            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Jan 21 17:04:44 dom0 qubesd[12640]:   File "/usr/lib/python3.11/site-packages/qubes/api/admin.py", line 287, in _property_set
Jan 21 17:04:44 dom0 qubesd[12640]:     setattr(dest, self.arg, newvalue)
Jan 21 17:04:44 dom0 qubesd[12640]:   File "/usr/lib/python3.11/site-packages/qubes/vm/__init__.py", line 502, in __set__
Jan 21 17:04:44 dom0 qubesd[12640]:     super().__set__(instance, vm)
Jan 21 17:04:44 dom0 qubesd[12640]:   File "/usr/lib/python3.11/site-packages/qubes/__init__.py", line 273, in __set__
Jan 21 17:04:44 dom0 qubesd[12640]:     instance.fire_event('property-set:' + self.__name__,
Jan 21 17:04:44 dom0 qubesd[12640]:   File "/usr/lib/python3.11/site-packages/qubes/events.py", line 195, in fire_event
Jan 21 17:04:44 dom0 qubesd[12640]:     sync_effects, async_effects = self._fire_event(event, kwargs,
Jan 21 17:04:44 dom0 qubesd[12640]:                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Jan 21 17:04:44 dom0 qubesd[12640]:   File "/usr/lib/python3.11/site-packages/qubes/events.py", line 164, in _fire_event
Jan 21 17:04:44 dom0 qubesd[12640]:     effect = func(self, event, **kwargs)
Jan 21 17:04:44 dom0 qubesd[12640]:              ^^^^^^^^^^^^^^^^^^^^^^^^^^^
Jan 21 17:04:44 dom0 qubesd[12640]:   File "/usr/lib/python3.11/site-packages/qubes/vm/mix/net.py", line 489, in on_property_set_netvm
Jan 21 17:04:44 dom0 qubesd[12640]:     newvalue.fire_event('net-domain-connect', vm=self)
Jan 21 17:04:44 dom0 qubesd[12640]:   File "/usr/lib/python3.11/site-packages/qubes/events.py", line 195, in fire_event
Jan 21 17:04:44 dom0 qubesd[12640]:     sync_effects, async_effects = self._fire_event(event, kwargs,
Jan 21 17:04:44 dom0 qubesd[12640]:                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Jan 21 17:04:44 dom0 qubesd[12640]:   File "/usr/lib/python3.11/site-packages/qubes/events.py", line 164, in _fire_event
Jan 21 17:04:44 dom0 qubesd[12640]:     effect = func(self, event, **kwargs)
Jan 21 17:04:44 dom0 qubesd[12640]:              ^^^^^^^^^^^^^^^^^^^^^^^^^^^
Jan 21 17:04:44 dom0 qubesd[12640]: TypeError: QubesNetworkServerExtension.on_net_domain_connect() got multiple values for argument 'vm'

When running qvm-prefs <disposable vm> netvm <desired netvm>, I get the following output:

qvm-prefs: error: Failed to access 'netvm' property

Steps to reproduce

1. Open Qube Manager
2. Right click vm -> Network -> select desired net qube
3. Click "Yes" to confirmation prompt.

Alternatively:

1. Open dom0 terminal
2. Run qvm-prefs <disposable vm> netvm sys-net

Expected behavior

Netvm changes without the qube manager crashing or the qvm-prefs giving a failure message.

Actual behavior

Qube Manager crashes, qvm-prefs displays a failure message, netvm does not change.

Additional information

I included the details of qube-manager crashing as I'm not sure it giving a coredump is expected behavior (as opposed to displaying an error to the user). I would debug this problem further as I am familiar with python but this appears related to an event within the code for qubesd and I wasn't able to follow it's execution path as I am unfamiliar with the codebase.