rebase: update kubernetes to v1.25.0

update kubernetes to latest v1.25.0
release.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/k8s.io/pod-security-admission/policy/check_sysctls.go

@@ -0,0 +1,96 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package policy
+
+import (
+	"strings"
+
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/pod-security-admission/api"
+)
+
+/*
+
+Sysctls can disable security mechanisms or affect all containers on a host,
+and should be disallowed except for an allowed "safe" subset.
+
+A sysctl is considered safe if it is namespaced in the container or the Pod,
+and it is isolated from other Pods or processes on the same Node.
+
+**Restricted Fields:**
+spec.securityContext.sysctls[*].name
+
+**Allowed Values:**
+'kernel.shm_rmid_forced'
+'net.ipv4.ip_local_port_range'
+'net.ipv4.tcp_syncookies'
+'net.ipv4.ping_group_range'
+'net.ipv4.ip_unprivileged_port_start'
+
+*/
+
+func init() {
+	addCheck(CheckSysctls)
+}
+
+// CheckSysctls returns a baseline level check
+// that limits the value of sysctls in 1.0+
+func CheckSysctls() Check {
+	return Check{
+		ID:    "sysctls",
+		Level: api.LevelBaseline,
+		Versions: []VersionedCheck{
+			{
+				MinimumVersion: api.MajorMinorVersion(1, 0),
+				CheckPod:       sysctls_1_0,
+			},
+		},
+	}
+}
+
+var (
+	sysctls_allowed_1_0 = sets.NewString(
+		"kernel.shm_rmid_forced",
+		"net.ipv4.ip_local_port_range",
+		"net.ipv4.tcp_syncookies",
+		"net.ipv4.ping_group_range",
+		"net.ipv4.ip_unprivileged_port_start",
+	)
+)
+
+func sysctls_1_0(podMetadata *metav1.ObjectMeta, podSpec *corev1.PodSpec) CheckResult {
+	var forbiddenSysctls []string
+
+	if podSpec.SecurityContext != nil {
+		for _, sysctl := range podSpec.SecurityContext.Sysctls {
+			if !sysctls_allowed_1_0.Has(sysctl.Name) {
+				forbiddenSysctls = append(forbiddenSysctls, sysctl.Name)
+			}
+		}
+	}
+
+	if len(forbiddenSysctls) > 0 {
+		return CheckResult{
+			Allowed:         false,
+			ForbiddenReason: "forbidden sysctls",
+			ForbiddenDetail: strings.Join(forbiddenSysctls, ", "),
+		}
+	}
+	return CheckResult{Allowed: true}
+}