- The `TerminationGracePeriodSeconds` on pod specs and container probes should not be negative. Negative values of `TerminationGracePeriodSeconds` will be treated as the value `1s` on the delete path. Immutable field validation will be relaxed in order to update negative values. In a future release, negative values will not be permitted. ([#98866](https://github.com/kubernetes/kubernetes/pull/98866), [@wzshiming](https://github.com/wzshiming))

- Fixes a panic in kube-controller-manager handling StatefulSet objects when revisionHistoryLimit is negative ([#129325](https://github.com/kubernetes/kubernetes/pull/129325), [@ardaguclu](https://github.com/ardaguclu)) [SIG Apps]

  The `skippedScorePlugins` number might be greater than `enabledScorePlugins`, 
  so when initializing a slice the cap(len(skippedScorePlugins) - len(enabledScorePlugins)) is negative, 
  which is not allowed. ([#121666](https://github.com/kubernetes/kubernetes/pull/121666), [@kerthcet](https://github.com/kerthcet)) [SIG Scheduling]

- Added a validation for the `revisionHistoryLimit` field in the `.spec` of a StatefulSet, to prevent it from being set to a negative value. ([#129017](https://github.com/kubernetes/kubernetes/pull/129017), [@ardaguclu](https://github.com/ardaguclu))

- Set kubelet option `--volume-stats-agg-period` to negative value to disable volume calculations. ([#96675](https://github.com/kubernetes/kubernetes/pull/96675), [@pacoxu](https://github.com/pacoxu)) [SIG Node]

### Failing Test

### Network

- Reduces the cache TTL for negative responses to 5s minimum. ([#74093](https://github.com/kubernetes/kubernetes/pull/74093), [@blakebarnett](https://github.com/blakebarnett))

### Node

- Since golang 1.17 both net.ParseIP and net.ParseCIDR rejects leading zeros in the dot-decimal notation of IPv4 addresses,
  Kubernetes will keep allowing leading zeros on IPv4 address to not break the compatibility.

- Fixed binding of block PersistentVolumes / PersistentVolumeClaims when BlockVolume feature is off. ([#84049](https://github.com/kubernetes/kubernetes/pull/84049), [@jsafrane](https://github.com/jsafrane))
- Report non-confusing error for negative storage size in PVC spec. ([#82759](https://github.com/kubernetes/kubernetes/pull/82759), [@sttts](https://github.com/sttts))

- in an `--encryption-provider-config` config file, an explicit `cacheSize: 0` parameter previously silently defaulted to caching 1000 keys. In Kubernetes 1.18, this now returns a config validation error. To disable caching, you can specify a negative cacheSize value in Kubernetes 1.18+.

### Juju
* The kubernetes-master, kubernetes-worker and kubeapi-load-balancer charms have gained an nrpe-external-master relation, allowing the integration of their monitoring in an external Nagios server. ([#41923](https://github.com/kubernetes/kubernetes/pull/41923), [@Cynerva](https://github.com/Cynerva))