[BUG] pdbminavailable check crashes on PDB with minAvailable and no selector #1041
Description
System info:
Using kube-linter CLI v0.7.6 on Fedora Linux 42, but also observed this behavior with a downstream consumer (Deployment Validation Operator)
Describe the bug
kube-linter panics with a "nil pointer dereference" when its pdbminavailable check encounters a PodDisruptionBudget that has spec.minAvailable defined but is missing the required spec.selector field.
To Reproduce
- Create a file named
bad-pdb.yamlwith the content below. - Run
kube-linter lint bad-pdb.yaml.
Sample YAML input
apiVersion: policy/v1
kind: PodDisruptionBudget
spec:
minAvailable: 40%Expected behavior
kube-linter should not panic. It should report a linting error because the PDB is invalid due to the missing spec.selector.
Additional context
Full stack trace from the panic:
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x19e533d]
goroutine 1 [running]:
golang.stackrox.io/kube-linter/pkg/templates/pdbminavailable.minAvailableCheck({0x220f368, 0xc0006338c0}, {{{0xc0004abc40, 0x34}, {0xc000540280, 0x49, 0x80}}, {0x224b1f8, 0xc0006bf340}})
golang.stackrox.io/kube-linter/pkg/templates/pdbminavailable/template.go:81 +0x1bd
golang.stackrox.io/kube-linter/pkg/run.Run({0xc00032fd90, 0x1, 0x0?}, {0x220efa8, 0xc00067b020}, {0xc0001b8a00?, 0x1f?, 0x0?})
golang.stackrox.io/kube-linter/pkg/run/run.go:63 +0x8a3
golang.stackrox.io/kube-linter/pkg/command/lint.Command.func1(0xc000167600?, {0xc00071b660, 0x1, 0x1eb2620?})
golang.stackrox.io/kube-linter/pkg/command/lint/command.go:129 +0x7b2
github.com/spf13/cobra.(*Command).execute(0xc0006c0c08, {0xc00071b630, 0x1, 0x1})
github.com/spf13/[email protected]/command.go:1015 +0xb02
github.com/spf13/cobra.(*Command).ExecuteC(0xc0006c0308)
github.com/spf13/[email protected]/command.go:1148 +0x465
github.com/spf13/cobra.(*Command).Execute(0x0?)
github.com/spf13/[email protected]/command.go:1071 +0x13
main.main()
golang.stackrox.io/kube-linter/cmd/kube-linter/kube-linter.go:14 +0x18