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seccomp: block socket calls to AF_VSOCK in default profile
This syncs the seccomp-profile with the latest changes in containerd's profile, applying the same changes as containerd/containerd@17a9324 Some background from the associated ticket: > We want to use vsock for guest-host communication on KubeVirt > (https://github.com/kubevirt/kubevirt). In KubeVirt we run VMs in pods. > > However since anyone can just connect from any pod to any VM with the > default seccomp settings, we cannot limit connection attempts to our > privileged node-agent. > > ### Describe the solution you'd like > We want to deny the `socket` syscall for the `AF_VSOCK` family by default. > > I see in [1] and [2] that AF_VSOCK was actually already blocked for some > time, but that got reverted since some architectures support the `socketcall` > syscall which can't be restricted properly. However we are mostly interested > in `arm64` and `amd64` where limiting `socket` would probably be enough. > > ### Additional context > I know that in theory we could use our own seccomp profiles, but we would want > to provide security for as many users as possible which use KubeVirt, and there > it would be very helpful if this protection could be added by being part of the > DefaultRuntime profile to easily ensure that it is active for all pods [3]. > > Impact on existing workloads: It is unlikely that this will disturb any existing > workload, becuase VSOCK is almost exclusively used for host-guest commmunication. > However if someone would still use it: Privileged pods would still be able to > use `socket` for `AF_VSOCK`, custom seccomp policies could be applied too. > Further it was already blocked for quite some time and the blockade got lifted > due to reasons not related to AF_VSOCK. > > The PR in KubeVirt which adds VSOCK support for additional context: [4] > > [1]: moby#29076 (comment) > [2]: moby@dcf2632 > [3]: https://kubernetes.io/docs/tutorials/security/seccomp/#enable-the-use-of-runtimedefault-as-the-default-seccomp-profile-for-all-workloads > [4]: kubevirt/kubevirt#8546 Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
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