* fix GetVolumeLimits log flushing issue ([#69558](https://github.com/kubernetes/kubernetes/pull/69558), [@andyzhangx](https://github.com/andyzhangx))
* kube-apiserver: fixes `procMount` field incorrectly being marked as required in openapi schema ([#69744](https://github.com/kubernetes/kubernetes/pull/69744), [@jessfraz](https://github.com/jessfraz))

- Fixed performance issue when creating large objects using SSA with fully unspecified schemas ( preserveUnknownFields ). ([#111557](https://github.com/kubernetes/kubernetes/pull/111557), [@alexzielenski](https://github.com/alexzielenski))

## Changelog since v1.20.11

## Changes by Kind

### API Change

- Kube-apiserver: Fixes handling of CRD schemas containing literal null values in enums (#104990, @liggitt) [SIG API Machinery, Apps and Network]

### Bug or Regression

		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMalformedXML: {
		Code:           "MalformedXML",
		Description:    "The XML you provided was not well-formed or did not validate against our published schema.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMissingContentLength: {
		Code:           "MissingContentLength",
		Description:    "You must provide the Content-Length HTTP header.",

- Fix performance issue when creating large objects using SSA with fully unspecified schemas (preserveUnknownFields). ([#111915](https://github.com/kubernetes/kubernetes/pull/111915), [@aojea](https://github.com/aojea)) [SIG API Machinery, Architecture, Auth, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation, Storage and Testing]

- Kube-apiserver: fixes a potential crash serving CustomResourceDefinitions that combine an invalid schema and CEL validation rules. ([#126167](https://github.com/kubernetes/kubernetes/pull/126167), [@cici37](https://github.com/cici37)) [SIG API Machinery and Testing]

- Fixed nil pointer error in `NodeVolumeLimits` csi logging ([#115179](https://github.com/kubernetes/kubernetes/pull/115179), [@sunnylovestiramisu](https://github.com/sunnylovestiramisu))
- Fixed panic validating custom resource definition schemas that set `multipleOf` to 0 ([#114869](https://github.com/kubernetes/kubernetes/pull/114869), [@liggitt](https://github.com/liggitt))

- Added support for CEL(Common Expression Language) expressions and `additionalProperties` to be used under nested quantifiers in CRD schemas. ([#124381](https://github.com/kubernetes/kubernetes/pull/124381), [@alexzielenski](https://github.com/alexzielenski)) [SIG API Machinery]
- Added support for building Windows kube-proxy container image.

- Kube-apiserver: openapi schemas published for custom resources now reference standard ListMeta schema definitions ([#92546](https://github.com/kubernetes/kubernetes/pull/92546), [@liggitt](https://github.com/liggitt)) [SIG API Machinery]

## Changelog since v1.21.5

## Changes by Kind

### API Change

- Kube-apiserver: Fixes handling of CRD schemas containing literal null values in enums (#104989, @liggitt) [SIG API Machinery, Apps and Network]

### Feature