I'm experiencing the problem after updating my box from Fedora 35 to 36.
I'm not able to load all my old snapshots (the ones I made under Fedora 35) and also the fresh ones  I made after update.
My VMs did't use any usb devices.

Thanks for taking the time to report this bug.

QEMU's vmstate is failing on loading the usbredir's device. As you have pointed out you actually don't have a usb device connected, this probably means a incompatibility between source-host usbredirparser_serialize() to destination-host usbredirparser_unserialize().

Which usbredir version you have installed in your source-host? I've updated usbredir three times in Fedora 35, 0.8.0, 0.10.0 and 0.12.0...

(In reply to Victor Toso from comment #2)
> Thanks for taking the time to report this bug.
> 
> QEMU's vmstate is failing on loading the usbredir's device. As you have
> pointed out you actually don't have a usb device connected, this probably
> means a incompatibility between source-host usbredirparser_serialize() to
> destination-host usbredirparser_unserialize().
> 
> Which usbredir version you have installed in your source-host? I've updated
> usbredir three times in Fedora 35, 0.8.0, 0.10.0 and 0.12.0...

Hello,
I found this:
[root@localhost peppe]# dnf info usbredir
Ultima verifica della scadenza dei metadati: 2:33:46 fa il mar 21 giu 2022, 16:12:05.
Pacchetti installati
Name         : usbredir
Version      : 0.12.0
Rilascio     : 2.fc36
Architecture : x86_64
Size         : 115 k
Sorgente     : usbredir-0.12.0-2.fc36.src.rpm
Repository   : @System
Dal repo     : fedora
Summary      : USB network redirection protocol libraries
URL          : https://www.spice-space.org/usbredir.html
Licenza      : LGPLv2+
Description  : The usbredir libraries allow USB devices to be used on remote
             : and/or virtual hosts over TCP.  The following libraries are
             : provided:
             : 
             : usbredirparser:
             : A library containing the parser for the usbredir protocol
             : 
             : usbredirhost:
             : A library implementing the USB host side of a usbredir
             : connection. All that an application wishing to implement a USB
             : host needs to do is:
             : * Provide a libusb device handle for the device
             : * Provide write and read callbacks for the actual transport of
             :   usbredir data
             : * Monitor for usbredir and libusb read/write events and call
             :   their handlers

(In reply to Giuseppe Maugeri from comment #3)
> (In reply to Victor Toso from comment #2)
> > Thanks for taking the time to report this bug.
> > 
> > QEMU's vmstate is failing on loading the usbredir's device. As you have
> > pointed out you actually don't have a usb device connected, this probably
> > means a incompatibility between source-host usbredirparser_serialize() to
> > destination-host usbredirparser_unserialize().
> > 
> > Which usbredir version you have installed in your source-host? I've updated
> > usbredir three times in Fedora 35, 0.8.0, 0.10.0 and 0.12.0...
> 
> Hello,
> I found this:
> [root@localhost peppe]# dnf info usbredir
> Ultima verifica della scadenza dei metadati: 2:33:46 fa il mar 21 giu 2022,
> 16:12:05.
> Pacchetti installati
> Name         : usbredir
> Version      : 0.12.0
> Rilascio     : 2.fc36
> Architecture : x86_64
> Size         : 115 k
> Sorgente     : usbredir-0.12.0-2.fc36.src.rpm
> Repository   : @System
> Dal repo     : fedora
> Summary      : USB network redirection protocol libraries
> URL          : https://www.spice-space.org/usbredir.html
> Licenza      : LGPLv2+
> Description  : The usbredir libraries allow USB devices to be used on remote
>              : and/or virtual hosts over TCP.  The following libraries are
>              : provided:
>              : 
>              : usbredirparser:
>              : A library containing the parser for the usbredir protocol
>              : 
>              : usbredirhost:
>              : A library implementing the USB host side of a usbredir
>              : connection. All that an application wishing to implement a USB
>              : host needs to do is:
>              : * Provide a libusb device handle for the device
>              : * Provide write and read callbacks for the actual transport of
>              :   usbredir data
>              : * Monitor for usbredir and libusb read/write events and call
>              :   their handlers

Just to confirm your finding I also tried to compile Qemu from vanilla sources, both versions 7.0.0 and 6.1.1, but I have still experienced the same problem with both.

A fix was submitted upstream

https://gitlab.freedesktop.org/spice/usbredir/-/merge_requests/61

The issue is on 0.12.0 version only. unserialize() changed behavior while fixing a leak.

(In reply to Victor Toso from comment #5)
> A fix was submitted upstream
> 
> https://gitlab.freedesktop.org/spice/usbredir/-/merge_requests/61
> 
> The issue is on 0.12.0 version only. unserialize() changed behavior while
> fixing a leak.

Thanks!!

FEDORA-2022-d36a5e3f77 has been submitted as an update to Fedora 36. https://bodhi.fedoraproject.org/updates/FEDORA-2022-d36a5e3f77

FEDORA-2022-d36a5e3f77 has been pushed to the Fedora 36 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2022-d36a5e3f77`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2022-d36a5e3f77

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

FEDORA-2022-d36a5e3f77 has been pushed to the Fedora 36 stable repository.
If problem still persists, please make note of it in this bug report.

FEDORA-2022-32edf6bc3d has been submitted as an update to Fedora 38. https://bodhi.fedoraproject.org/updates/FEDORA-2022-32edf6bc3d

FEDORA-2022-32edf6bc3d has been pushed to the Fedora 38 stable repository.
If problem still persists, please make note of it in this bug report.