fix: AllowList DNS exemption for guest-hardcoded resolvers - #40
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Signed-off-by: danbugs <danilochiarlone@gmail.com>
The AllowList DNS exemption only covered the host's resolvers from /etc/resolv.conf, but the guest hardcodes 8.8.8.8/8.8.4.4 in its initrd. On any host with different resolvers, AllowList silently broke DNS resolution. Add Google (8.8.8.8, 8.8.4.4) and Cloudflare (1.1.1.1, 1.0.0.1) to the exempted resolver set. Port 53 to arbitrary IPs is still blocked, preserving the anti-exfiltration property. Signed-off-by: danbugs <danilochiarlone@gmail.com>
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Linux Benchmarks
Details
| Benchmark suite | Current: bf35761 | Previous: 110b50d | Ratio |
|---|---|---|---|
hello_world (median) |
20 ms |
10 ms |
2 |
pandas (median) |
100 ms |
80 ms |
1.25 |
density (per VM) |
7 MB |
7 MB |
1 |
snapshot (disk) |
385 MiB |
385 MiB |
1 |
This comment was automatically generated by workflow using github-action-benchmark.
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Windows Benchmarks
Details
| Benchmark suite | Current: bf35761 | Previous: 110b50d | Ratio |
|---|---|---|---|
hello_world (median) |
236 ms |
241 ms |
0.98 |
pandas (median) |
716 ms |
754 ms |
0.95 |
density (per VM) |
6 MB |
6 MB |
1 |
snapshot (disk) |
393 MiB |
393 MiB |
1 |
This comment was automatically generated by workflow using github-action-benchmark.
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Summary
Root cause
The guest's
/etc/resolv.confhardcodes8.8.8.8and8.8.4.4, but the AllowList DNS exemption only covered the host's resolvers (from/etc/resolv.conforipconfig /all). On any host where those don't match (CI runners, corporate networks, etc.), AllowList silently broke DNS resolution.Port 53 to arbitrary IPs is still blocked — preserving the anti-exfiltration property from the original audit fix (PR #32).
Test plan
cargo test --libpasses on Linux (48/48) and Windows (41/41)cargo clippy --all-targets -- -D warningsclean on both platformsnetworking-pywith--net