REDHAT-BUG-2270717: Medium severity Podman Podman vulnerability

Summary: We received a report of an attack vector on containers which share an IPC namespace (definitely Podman, but likely also applicable to Kubernetes, Docker, and other container runtimes). At least two containers are configured with a shared IPC namespace and a cgroup limiting memory. One of those containers is malicious, and contains a binary which creates a large number of IPC resources in /dev/shm, and continues doing so until it is OOM killed. The malicious container is now dead, its cgroup removed, but the IPC resources it created are not; they are tied to the IPC namespace that will not be removed until all containers using it are stopped, and one non-malicious container is holding the namespace open. The malicious container is restarted (either automatically or by attacker control), repeating the process and increasing the amount of memory consumed. With a container configured to restart always (e.g. podman run --restart=always) this results in a memory-based denial of service of the system.

Podman Version: Version 5.0.0-dev and before