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Restrict the allowed syscalls in seccomp profiles

The Security Profiles Operator does not restrict syscalls in seccomp profiles by default. You can define the list of allowed syscalls in the spod configuration.

Procedure
  • To define the list of allowedSyscalls, adjust the spec parameter by running the following command:

    $ oc -n openshift-security-profiles patch spod spod --type merge \
        -p '{"spec":{"allowedSyscalls": ["exit", "exit_group", "futex", "nanosleep"]}}'

The Operator will install only the seccomp profiles, which have a subset of syscalls defined into the allowed list. All profiles not complying with this ruleset are rejected.

When the list of allowed syscalls is modified in the spod configuration, the Operator will identify the already installed profiles which are non-compliant and remove them automatically.

Base syscalls for a container runtime

You can use the baseProfileName attribute to establish the minimum required syscalls for a given runtime to start a container.

Procedure
  • Edit the SeccompProfile kind object and add baseProfileName: runc-v1.0.0 to the spec field:

    apiVersion: security-profiles-operator.x-k8s.io/v1beta1
    kind: SeccompProfile
    metadata:
      namespace: my-namespace
      name: example-name
    spec:
      defaultAction: SCMP_ACT_ERRNO
      baseProfileName: runc-v1.0.0
      syscalls:
        - action: SCMP_ACT_ALLOW
          names:
            - exit_group

Using metrics

The openshift-security-profiles namespace provides metrics endpoints, which are secured by the kube-rbac-proxy container. All metrics are exposed by the metrics service within the openshift-security-profiles namespace.

The Security Profiles Operator includes a cluster role and corresponding binding spo-metrics-client to retrieve the metrics from within the cluster. There are two metrics paths available:

  • metrics.openshift-security-profiles/metrics: for controller runtime metrics

  • metrics.openshift-security-profiles/metrics-spod: for the Operator daemon metrics

Procedure
  1. To view the status of the metrics service, run the following command:

    $ oc get svc/metrics -n openshift-security-profiles
    Example output
    NAME      TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
    metrics   ClusterIP   10.0.0.228   <none>        443/TCP   43s
  2. To retrieve the metrics, query the service endpoint using the default ServiceAccount token in the openshift-security-profiles namespace by running the following command:

    $ oc run --rm -i --restart=Never --image=registry.fedoraproject.org/fedora-minimal:latest \
        -n openshift-security-profiles metrics-test -- bash -c \
        'curl -ks -H "Authorization: Bearer $(cat /var/run/secrets/kubernetes.io/serviceaccount/token)" https://metrics.openshift-security-profiles/metrics-spod'
    Example output
    # HELP security_profiles_operator_seccomp_profile_total Counter about seccomp profile operations.
    # TYPE security_profiles_operator_seccomp_profile_total counter
    security_profiles_operator_seccomp_profile_total{operation="delete"} 1
    security_profiles_operator_seccomp_profile_total{operation="update"} 2
  3. To retrieve metrics from a different namespace, link the ServiceAccount to the spo-metrics-client ClusterRoleBinding by running the following command:

    $ oc get clusterrolebinding spo-metrics-client -o wide
    Example output
    NAME                 ROLE                             AGE   USERS   GROUPS   SERVICEACCOUNTS
    spo-metrics-client   ClusterRole/spo-metrics-client   35m                    openshift-security-profiles/default

controller-runtime metrics

The controller-runtime metrics and the DaemonSet endpoint metrics-spod provide a set of default metrics. Additional metrics are provided by the daemon, which are always prefixed with security_profiles_operator_.

Table 1. Available controller-runtime metrics
Metric key Possible labels Type Purpose

seccomp_profile_total

operation={delete,update}

Counter

Amount of seccomp profile operations.

seccomp_profile_audit_total

node, namespace, pod, container, executable, syscall

Counter

Amount of seccomp profile audit operations. Requires the log enricher to be enabled.

seccomp_profile_bpf_total

node, mount_namespace, profile

Counter

Amount of seccomp profile bpf operations. Requires the bpf recorder to be enabled.

seccomp_profile_error_total

reason={
SeccompNotSupportedOnNode,
InvalidSeccompProfile,
CannotSaveSeccompProfile,
CannotRemoveSeccompProfile,
CannotUpdateSeccompProfile,
CannotUpdateNodeStatus
}

Counter

Amount of seccomp profile errors.

selinux_profile_total

operation={delete,update}

Counter

Amount of SELinux profile operations.

selinux_profile_audit_total

node, namespace, pod, container, executable, scontext,tcontext

Counter

Amount of SELinux profile audit operations. Requires the log enricher to be enabled.

selinux_profile_error_total

reason={
CannotSaveSelinuxPolicy,
CannotUpdatePolicyStatus,
CannotRemoveSelinuxPolicy,
CannotContactSelinuxd,
CannotWritePolicyFile,
CannotGetPolicyStatus
}

Counter

Amount of SELinux profile errors.

Using the log enricher

The Security Profiles Operator contains a log enrichment feature, which is disabled by default. The log enricher container runs with privileged permissions to read the audit logs from the local node. The log enricher runs within the host PID namespace, hostPID.

The log enricher must have permissions to read the host processes.

Procedure
  1. Patch the spod configuration to enable the log enricher by running the following command:

    $ oc -n openshift-security-profiles patch spod spod \
        --type=merge -p '{"spec":{"enableLogEnricher":true}}'
    Example output
    securityprofilesoperatordaemon.security-profiles-operator.x-k8s.io/spod patched

    The Security Profiles Operator will re-deploy the spod daemon set automatically.

  2. View the audit logs by running the following command:

    $ oc -n openshift-security-profiles logs -f ds/spod log-enricher
    Example output
    I0623 12:51:04.257814 1854764 deleg.go:130] setup "msg"="starting component: log-enricher"  "buildDate"="1980-01-01T00:00:00Z" "compiler"="gc" "gitCommit"="unknown" "gitTreeState"="clean" "goVersion"="go1.16.2" "platform"="linux/amd64" "version"="0.4.0-dev"
    I0623 12:51:04.257890 1854764 enricher.go:44] log-enricher "msg"="Starting log-enricher on node: 127.0.0.1"
    I0623 12:51:04.257898 1854764 enricher.go:46] log-enricher "msg"="Connecting to local GRPC server"
    I0623 12:51:04.258061 1854764 enricher.go:69] log-enricher "msg"="Reading from file /var/log/audit/audit.log"
    2021/06/23 12:51:04 Seeked /var/log/audit/audit.log - &{Offset:0 Whence:2}

Using the log enricher to trace an application

You can use the Security Profiles Operator log enricher to trace an application.

Procedure
  1. To trace an application, create a SeccompProfile logging profile:

    apiVersion: security-profiles-operator.x-k8s.io/v1beta1
    kind: SeccompProfile
    metadata:
      name: log
      namespace: default
    spec:
      defaultAction: SCMP_ACT_LOG
  2. Create a pod object to use the profile:

    apiVersion: v1
    kind: Pod
    metadata:
      name: log-pod
    spec:
      securityContext:
        seccompProfile:
          type: Localhost
          localhostProfile: operator/default/log.json
      containers:
        - name: log-container
          image: quay.io/security-profiles-operator/test-nginx-unprivileged:1.21
  3. Examine the log enricher output by running the following command:

    $ oc -n openshift-security-profiles logs -f ds/spod log-enricher
    Example output
    …
    I0623 12:59:11.479869 1854764 enricher.go:111] log-enricher "msg"="audit"  "container"="log-container" "executable"="/" "namespace"="default" "node"="127.0.0.1" "pid"=1905792 "pod"="log-pod" "syscallID"=3 "syscallName"="close" "timestamp"="1624453150.205:1061" "type"="seccomp"
    I0623 12:59:11.487323 1854764 enricher.go:111] log-enricher "msg"="audit"  "container"="log-container" "executable"="/" "namespace"="default" "node"="127.0.0.1" "pid"=1905792 "pod"="log-pod" "syscallID"=157 "syscallName"="prctl" "timestamp"="1624453150.205:1062" "type"="seccomp"
    I0623 12:59:11.492157 1854764 enricher.go:111] log-enricher "msg"="audit"  "container"="log-container" "executable"="/" "namespace"="default" "node"="127.0.0.1" "pid"=1905792 "pod"="log-pod" "syscallID"=157 "syscallName"="prctl" "timestamp"="1624453150.205:1063" "type"="seccomp"
    …
    I0623 12:59:20.258523 1854764 enricher.go:111] log-enricher "msg"="audit"  "container"="log-container" "executable"="/usr/sbin/nginx" "namespace"="default" "node"="127.0.0.1" "pid"=1905792 "pod"="log-pod" "syscallID"=12 "syscallName"="brk" "timestamp"="1624453150.235:2873" "type"="seccomp"
    I0623 12:59:20.263349 1854764 enricher.go:111] log-enricher "msg"="audit"  "container"="log-container" "executable"="/usr/sbin/nginx" "namespace"="default" "node"="127.0.0.1" "pid"=1905792 "pod"="log-pod" "syscallID"=21 "syscallName"="access" "timestamp"="1624453150.235:2874" "type"="seccomp"
    I0623 12:59:20.354091 1854764 enricher.go:111] log-enricher "msg"="audit"  "container"="log-container" "executable"="/usr/sbin/nginx" "namespace"="default" "node"="127.0.0.1" "pid"=1905792 "pod"="log-pod" "syscallID"=257 "syscallName"="openat" "timestamp"="1624453150.235:2875" "type"="seccomp"
    I0623 12:59:20.358844 1854764 enricher.go:111] log-enricher "msg"="audit"  "container"="log-container" "executable"="/usr/sbin/nginx" "namespace"="default" "node"="127.0.0.1" "pid"=1905792 "pod"="log-pod" "syscallID"=5 "syscallName"="fstat" "timestamp"="1624453150.235:2876" "type"="seccomp"
    I0623 12:59:20.363510 1854764 enricher.go:111] log-enricher "msg"="audit"  "container"="log-container" "executable"="/usr/sbin/nginx" "namespace"="default" "node"="127.0.0.1" "pid"=1905792 "pod"="log-pod" "syscallID"=9 "syscallName"="mmap" "timestamp"="1624453150.235:2877" "type"="seccomp"
    I0623 12:59:20.454127 1854764 enricher.go:111] log-enricher "msg"="audit"  "container"="log-container" "executable"="/usr/sbin/nginx" "namespace"="default" "node"="127.0.0.1" "pid"=1905792 "pod"="log-pod" "syscallID"=3 "syscallName"="close" "timestamp"="1624453150.235:2878" "type"="seccomp"
    I0623 12:59:20.458654 1854764 enricher.go:111] log-enricher "msg"="audit"  "container"="log-container" "executable"="/usr/sbin/nginx" "namespace"="default" "node"="127.0.0.1" "pid"=1905792 "pod"="log-pod" "syscallID"=257 "syscallName"="openat" "timestamp"="1624453150.235:2879" "type"="seccomp"
    …

Configuring webhooks

Profile binding and profile recording objects can use webhooks. Profile binding and recording object configurations are MutatingWebhookConfiguration CRs, managed by the Security Profiles Operator.

To change the webhook configuration, the spod CR exposes a webhookOptions field that allows modification of the failurePolicy, namespaceSelector, and objectSelector variables. This allows you to set the webhooks to "soft-fail" or restrict them to a subset of a namespaces so that even if the webhooks failed, other namespaces or resources are not affected.

Procedure
  1. Set the recording.spo.io webhook configuration to record only pods labeled with spo-record=true by creating the following patch file:

    spec:
      webhookOptions:
        - name: recording.spo.io
          objectSelector:
            matchExpressions:
              - key: spo-record
                operator: In
                values:
                  - "true"
  2. Patch the spod/spod instance by running the following command:

    $ oc -n openshift-security-profiles patch spod \
        spod -p $(cat /tmp/spod-wh.patch) --type=merge
  3. To view the resulting MutatingWebhookConfiguration object, run the following command:

    $ oc get MutatingWebhookConfiguration \
        spo-mutating-webhook-configuration -oyaml