Cross posted with this coreos-status email.
The most recent kernel update to 5.16.13-200.fc35 has been reported
to cause failures for NFS clients connecting to some QNAP NASsystems.
Details of the issue as well as links to upstream forum posts and
downstream bug reports can be found in our issue tracker.
Fortunately this bug was caught in our
testing stream. Unfortunately,
we do need to proceed promoting this kernel into our
because the update will fix CVE-2022-0847 (known as “dirty pipe”).
If you will be affected by this bug, the easiest workaround is to switch
the mount options for the mount to add
vers=4.0 for NFS 4.0. You can
then follow progress in the tracker issue to know when to revert