feat(lab12): kata vs runc isolation + perf + escape PoC

[Maflock]

Goal

Install Kata as a containerd runtime, run the same workload on runc and kata to compare kernel isolation + performance overhead, then (bonus) demonstrate a real container-escape PoC succeeds on runc and fails on kata — the headline value-prop made concrete.

Changes

• Added submissions/lab12.md
• Added labs/lab12/results/

Testing

# 1. Verify KVM access and Kata installation
ls -la /dev/kvm && cat /opt/kata/VERSION
# Found: /dev/kvm accessible (crw-rw----+ 1 root kvm), Kata v3.32.0 installed


# 2. Verify both runtimes registered in containerd
grep -A 2 'runtimes.kata' /etc/containerd/config.toml
# Found: kata runtime registered as io.containerd.kata.v2


# 3. Verify kernel isolation — runc shares host kernel, kata uses guest kernel
sudo nerdctl run --rm alpine:3.20 uname -r && sudo nerdctl run --rm --runtime=io.containerd.kata.v2 alpine:3.20 uname -r
# Found: runc shows 6.17.0-40-generic (host kernel), kata shows 6.18.35-kata (guest VM kernel) — separate kernels confirmed


# 4. Verify performance overhead — cold start and I/O throughput
for r in runc kata; do echo "=== $r ==="; for i in 1 2 3 4 5; do START=$(date +%s.%N); sudo nerdctl run --rm ${FLAG} alpine:3.20 echo ok > /dev/null; END=$(date +%s.%N); echo "$(echo "$END - $START" | bc)s"; done; done
# Found: runc avg 0.657s, kata avg 2.152s — ~3.3× cold start overhead, better than Reading 12's expected ~5×


# 5. Verify container escape PoC — runc succeeds, kata fails
sudo nerdctl run --rm --privileged -v /tmp:/host_tmp alpine:3.20 sh -c 'echo "ESCAPED" > /host_tmp/lab12-target' && sudo cat /tmp/lab12-target
# Found: runc container writes directly to host filesystem — ESCAPED confirmed on host

sudo nerdctl run --rm --runtime=io.containerd.kata.v2 --privileged -v /tmp:/host_tmp alpine:3.20 sh -c 'echo "FAILED" > /host_tmp/lab12-target' 2>&1; sudo cat /tmp/lab12-target
# Found: Kata refuses to create container with full host device set — host file unchanged, escape blocked at hypervisor layer


# 6. Cleanup
sudo rm -f /tmp/lab12-target && sudo nerdctl ps -a -q | xargs -r sudo nerdctl rm -f
# All containers removed, host filesystem clean

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Artifacts & Screenshots

• submissions/lab12.md

Checklist

• Title is clear (feat(lab12): kata vs runc isolation + perf + escape PoC)
• No secrets/large temp files committed
• submissions/lab12.md exists
• Task 1 — Kata installed; both runtimes run; kernel diff documented
• Task 2 — Isolation + 5-run startup + I/O benchmark with trade-off analysis
• Bonus — Escape PoC succeeds on runc, fails on Kata (with host-side verification)