@@ -18,9 +18,11 @@ Improper use of kernel arguments can result in your systems becoming unbootable.
1818
1919Examples of kernel arguments you could set include:
2020
21- * **selinux=0**: Disables Security Enhanced Linux (SELinux).
22- While not recommended for production, disabling SELinux can
23- improve performance by 2% - 3%.
21+ * **enforcing=0**: Configures Security Enhanced Linux (SELinux) to run in permissive mode.
22+ In permissive mode, the system acts as if SELinux is enforcing the loaded security policy,
23+ including labeling objects and emitting access denial entries in the logs,
24+ but it does not actually deny any operations. While not recommended for production systems,
25+ permissive mode can be helpful for debugging.
2426
2527* **nosmt**: Disables symmetric multithreading (SMT) in the kernel.
2628Multithreading allows multiple logical threads for each CPU.
@@ -68,7 +70,7 @@ rendered-master-23e785de7587df95a4b517e0647e5ab7 52dd3ba6a9a527fc3ab42afac8d12
6870rendered-worker-5d596d9293ca3ea80c896a1191735bb1 52dd3ba6a9a527fc3ab42afac8d12b693534c8c9 3.2.0 33m
6971----
7072
71- . Create a `MachineConfig` object file that identifies the kernel argument (for example, `05-worker-kernelarg-selinuxoff .yaml`)
73+ . Create a `MachineConfig` object file that identifies the kernel argument (for example, `05-worker-kernelarg-selinuxpermissive .yaml`)
7274+
7375[source,yaml]
7476----
@@ -77,25 +79,25 @@ kind: MachineConfig
7779metadata:
7880 labels:
7981 machineconfiguration.openshift.io/role: worker<1>
80- name: 05-worker-kernelarg-selinuxoff <2>
82+ name: 05-worker-kernelarg-selinuxpermissive <2>
8183spec:
8284 config:
8385 ignition:
8486 version: 3.1.0
8587 kernelArguments:
86- - selinux =0<3>
88+ - enforcing =0<3>
8789----
8890+
8991<1> Applies the new kernel argument only to worker nodes.
9092<2> Named to identify where it fits among the machine configs (05) and what it does (adds
91- a kernel argument to turn off SELinux).
92- <3> Identifies the exact kernel argument as `selinux =0`.
93+ a kernel argument to configure SELinux permissive mode ).
94+ <3> Identifies the exact kernel argument as `enforcing =0`.
9395
9496. Create the new machine config:
9597+
9698[source,terminal]
9799----
98- $ oc create -f 05-worker-kernelarg-selinuxoff .yaml
100+ $ oc create -f 05-worker-kernelarg-selinuxpermissive .yaml
99101----
100102
101103. Check the machine configs to see that the new one was added:
@@ -116,7 +118,7 @@ NAME GENERATEDBYCONTROLLER
11611801-worker-container-runtime 52dd3ba6a9a527fc3ab42afac8d12b693534c8c9 3.2.0 33m
11711901-worker-kubelet 52dd3ba6a9a527fc3ab42afac8d12b693534c8c9 3.2.0 33m
118120
119- 05-worker-kernelarg-selinuxoff 3.1.0 105s
121+ 05-worker-kernelarg-selinuxpermissive 3.1.0 105s
120122
12112399-master-generated-registries 52dd3ba6a9a527fc3ab42afac8d12b693534c8c9 3.2.0 33m
12212499-master-ssh 3.1.0 40m
@@ -164,9 +166,9 @@ To use host binaries, run `chroot /host`
164166sh-4.2# cat /host/proc/cmdline
165167BOOT_IMAGE=/ostree/rhcos-... console=tty0 console=ttyS0,115200n8
166168rootflags=defaults,prjquota rw root=UUID=fd0... ostree=/ostree/boot.0/rhcos/16...
167- coreos.oem.id=qemu coreos.oem.id=ec2 ignition.platform.id=ec2 selinux =0
169+ coreos.oem.id=qemu coreos.oem.id=ec2 ignition.platform.id=ec2 enforcing =0
168170
169171sh-4.2# exit
170172----
171173+
172- You should see the `selinux =0` argument added to the other kernel arguments.
174+ You should see the `enforcing =0` argument added to the other kernel arguments.
0 commit comments