Argo Workflows (controller pod informer, pod-gc-strategy annotation parsing): A malformed

Impact

A malformed workflows.argoproj.io/pod-gc-strategy annotation makes the pod informer index past the end of a split, and the panic happens in an informer goroutine outside the controller's recover, killing the whole process. The poisoned pod survives restarts, so the controller crash-loops and every tenant's workflow scheduling stops until an operator manually finds and deletes that one pod.

Who can reach it

Anyone who can create or annotate a pod in a namespace the controller watches - which includes any tenant with normal pod-create rights, not just workflow submitters.

What to do

Upgrade the controller to 3.7.14 or 4.0.5 and restart it. To recover a cluster already in the crash loop, find the pod carrying the malformed annotation and delete it before or during the upgrade, otherwise the new controller crashes on the same object.

References