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e204d863a5
* Update Kubernetes to v1.22.1 * Update dependent modules to track with upstream Signed-off-by: Brad Davidson <brad.davidson@rancher.com>
97 lines
2.4 KiB
Go
97 lines
2.4 KiB
Go
/*
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Copyright 2021 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package policy
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import (
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"strings"
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corev1 "k8s.io/api/core/v1"
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metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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"k8s.io/apimachinery/pkg/util/sets"
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"k8s.io/pod-security-admission/api"
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)
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/*
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Sysctls can disable security mechanisms or affect all containers on a host,
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and should be disallowed except for an allowed "safe" subset.
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A sysctl is considered safe if it is namespaced in the container or the Pod,
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and it is isolated from other Pods or processes on the same Node.
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**Restricted Fields:**
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spec.securityContext.sysctls[*].name
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**Allowed Values:**
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'kernel.shm_rmid_forced'
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'net.ipv4.ip_local_port_range'
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'net.ipv4.tcp_syncookies'
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'net.ipv4.ping_group_range'
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'net.ipv4.ip_unprivileged_port_start'
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*/
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func init() {
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addCheck(CheckSysctls)
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}
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// CheckSysctls returns a baseline level check
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// that limits the value of sysctls in 1.0+
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func CheckSysctls() Check {
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return Check{
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ID: "sysctls",
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Level: api.LevelBaseline,
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Versions: []VersionedCheck{
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{
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MinimumVersion: api.MajorMinorVersion(1, 0),
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CheckPod: sysctls_1_0,
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},
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},
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}
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}
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var (
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sysctls_allowed_1_0 = sets.NewString(
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"kernel.shm_rmid_forced",
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"net.ipv4.ip_local_port_range",
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"net.ipv4.tcp_syncookies",
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"net.ipv4.ping_group_range",
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"net.ipv4.ip_unprivileged_port_start",
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)
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)
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func sysctls_1_0(podMetadata *metav1.ObjectMeta, podSpec *corev1.PodSpec) CheckResult {
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var forbiddenSysctls []string
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if podSpec.SecurityContext != nil {
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for _, sysctl := range podSpec.SecurityContext.Sysctls {
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if !sysctls_allowed_1_0.Has(sysctl.Name) {
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forbiddenSysctls = append(forbiddenSysctls, sysctl.Name)
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}
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}
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}
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if len(forbiddenSysctls) > 0 {
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return CheckResult{
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Allowed: false,
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ForbiddenReason: "forbidden sysctls",
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ForbiddenDetail: strings.Join(forbiddenSysctls, ", "),
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}
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}
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return CheckResult{Allowed: true}
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}
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