fix: add resource caps and DNS pointer-loop guard - #67
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…inter-loop guard - Add MAX_DISPATCH_PAYLOAD (64 MiB) check at top of dispatch() - Add MAX_FS_WRITE (16 MiB) check in fs_write and fs_write_bytes - Add MAX_TRUNCATE_LEN (1 GiB) check in fs_truncate - Add hop counter (max 128) in dns_read_name to prevent infinite loops from circular DNS compression pointers Signed-off-by: danbugs <danilochiarlone@gmail.com>
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Pull request overview
This PR hardens host-side dispatch and filesystem/DNS handling by adding resource caps and a DNS compression-pointer loop guard.
Changes:
- Adds payload limits for dispatch, filesystem writes, and truncation.
- Rejects oversized write/truncate operations with explicit errors.
- Adds a DNS name pointer hop counter to avoid infinite loops.
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| )); | ||
| } | ||
| let offset = args["offset"].as_u64(); | ||
| let append = args["append"].as_bool().unwrap_or(false); |
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| hops += 1; | ||
| if hops > 128 { | ||
| return None; |
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Linux Benchmarks
Details
| Benchmark suite | Current: 4611c78 | Previous: 5198570 | Ratio |
|---|---|---|---|
hello_world (median) |
20 ms |
20 ms |
1 |
pandas (median) |
110 ms |
110 ms |
1 |
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: 4611c78 | Previous: 5198570 | Ratio |
|---|---|---|---|
hello_world (median) |
228 ms |
191 ms |
1.19 |
pandas (median) |
655 ms |
540 ms |
1.21 |
density (per VM) |
6 MB |
6 MB |
1 |
snapshot (disk) |
392 MiB |
392 MiB |
1 |
This comment was automatically generated by workflow using github-action-benchmark.
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Summary
MAX_DISPATCH_PAYLOAD(64 MiB) — rejects oversized dispatch payloads before JSON parsing to prevent host OOMMAX_FS_WRITE(16 MiB) — capsfs_writeandfs_write_bytespayloads (matching the existingMAX_FS_READ)MAX_TRUNCATE_LEN(1 GiB) — prevents guest from creating extremely large sparse files viafs_truncatedns_read_nameto prevent infinite loops from circular DNS compression pointers in crafted responsesTest plan