- Implemented logging and event recording for probe results with an `Unknown` status in the kubelet's prober module. This helped improve the diagnosis and monitoring of cases where container probes returned an `Unknown` result, enhancing the observability and reliability of health checks. ([#125901](https://github.com/kubernetes/kubernetes/pull/125901), [@jralmaraz](https://github.com/jralmaraz))...

  - The issuer of the certificate was unknown (`x509.UnknownAuthorityError`)
  - The requested name did not match the set of authorized names (`x509.HostnameError`)

				t.Errorf("ReadLine returned both data and error: %s", err)
			}
			if isPrefix {
				t.Errorf("ReadLine returned prefix")
			}
			if err != nil {
				if err != io.EOF {
					t.Fatalf("Got unknown error: %s", err)
				}
				break
			}
			if want := testOutput[done : done+len(line)]; !bytes.Equal(want, line) {
				t.Errorf("Bad line at stride %d: want: %x got: %x", stride, want, line)
			}

	FMOVD	0x1006ff8(R1), F2	// FMOVD	16805880(R1), F2	// 3bfc7f9162ff7ffd

// very large or unaligned offset uses constant pool.
// the encoding cannot be checked as the address of the constant pool is unknown.
// here we only test that they can be assembled.
	MOVB	R1, 0x1000000(R2)	// MOVB		R1, 16777216(R2)
	MOVB	R1, 0x44332211(R2)	// MOVB		R1, 1144201745(R2)
	MOVH	R1, 0x1001000(R2)	// MOVH		R1, 16781312(R2)

	case siteResyncMetaFormat:
	default:
		return rs, fmt.Errorf("resyncMeta: unknown format: %d", binary.LittleEndian.Uint16(data[0:2]))
	}
	switch binary.LittleEndian.Uint16(data[2:4]) {
	case siteResyncMetaVersion:
	default:
		return rs, fmt.Errorf("resyncMeta: unknown version: %d", binary.LittleEndian.Uint16(data[2:4]))
	}
	// OK, parse data.

  - The issuer of the certificate is unknown (x509.UnknownAuthorityError)
  - The requested name does not match the set of authorized names (x509.HostnameError)

- Fixed a bug that prevents kubectl to validate CRDs with schema using x-kubernetes-preserve-unknown-fields on object fields.
  Fix kubectl SchemaError on CRDs with schema using x-kubernetes-preserve-unknown-fields on array types. ([#96562](https://github.com/kubernetes/kubernetes/pull/96562), [@gautierdelorme](https://github.com/gautierdelorme)) [SIG API Machinery and Testing]

* Fixes a bug in openapi published for custom resources using x-kubernetes-preserve-unknown-fields extensions, so that kubectl will allow sending unknown fields for that portion of the object. ([#79636](https://github.com/kubernetes/kubernetes/pull/79636), [@liggitt](https://github.com/liggitt))

- Kubeadm: improve the strict parsing of user YAML/JSON configuration files. Next to printing warnings for unknown and duplicate fields (current state), also print warnings for fields with incorrect case sensitivity - e.g. `controlPlaneEndpoint` (valid), `ControlPlaneEndpoint` (invalid). Instead of only printing warnings during `init` and `join` also print warnings...

                        }
                    }
                }
            }

            this.isExists = true;

        } catch (final UnknownHostException uhe) {
            log.debug("Unknown host", uhe);
            // Cache negative result for host resolution failures
            this.attrExpiration = currentTime + Math.min(getContext().getConfig().getAttributeCacheTimeout(), 30000);
            return false;