[issue #7] Validate host paths and container mounts

[Saber5656]

Summary

• add fail-closed validation for host files, directories, and relative sync paths
• parse and validate Docker/Podman volume, bind-mount, tmpfs, and device arguments
• block runtime sockets, configuration directories, ancestor mounts, symlink aliases, rootless containerd paths, and local volume-driver escapes
• keep internal mount provenance crate-controlled and validate normalized mount state

Validation

• cargo fmt --all -- --check
• cargo test --all-features --locked
• cargo clippy --all-targets --all-features --locked -- -D warnings
• git diff --check
• independent tech-security review: approve

Closes #7

Summary by CodeRabbit

• New Features

  • Added security validation for container mount arguments, including bind mounts, devices, named volumes, and temporary filesystems.
  • Added safeguards to block mounts targeting protected runtime and configuration paths.
  • Added validation for directory paths, file paths, and project-relative sync paths, including traversal and symlink escape checks.
  • Malformed or unsupported mount configurations are rejected safely.

• Tests

  • Added comprehensive coverage for mount parsing, path validation, and security boundary cases.

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Review details

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 0ca368a5-0ab8-44ed-b49a-6c6f6e75793c

📥 Commits

Reviewing files that changed from the base of the PR and between 8c09dc2 and f96f5f1.

📒 Files selected for processing (3)

• src/security/mod.rs
• src/security/mount.rs
• src/security/path.rs

📝 Walkthrough

Walkthrough

Adds security path validation and runtime mount parsing. It canonicalizes filesystem inputs, blocks protected runtime/config paths, validates relative sync destinations, normalizes supported mount flags, and enforces mount provenance and shape rules.

Changes

Security validation

Layer / File(s)	Summary
Path validation policy src/security/path.rs	Defines SecurityError, blocked-root policy checks, directory validation, canonicalization helpers, and filesystem path safety rules.
Relative sync path validation src/security/path.rs	Validates sync destinations against the canonical project root, including missing leaf files and symlink escapes.
Runtime mount parsing src/security/mount.rs	Adds mount types and parses -v, --volume, --mount, and --device forms, including named-volume and tmpfs handling.
Mount policy enforcement src/security/mount.rs, src/security/mod.rs	Validates mount shape, applies host-path checks to user mounts, preserves internal and named-volume bypasses, and re-exports the security API.

Estimated code review effort: 4 (Complex) | ~45 minutes

Sequence Diagram(s)

sequenceDiagram
  participant RuntimeArgs
  participant parse_runtime_mounts
  participant Mount
  participant validate_mounts
  participant PathPolicy
  participant Filesystem

  RuntimeArgs->>parse_runtime_mounts: recognized mount arguments
  parse_runtime_mounts->>Mount: normalized mount data
  Mount->>validate_mounts: parsed mounts
  validate_mounts->>PathPolicy: user host path
  PathPolicy->>Filesystem: canonicalize and inspect path
  Filesystem-->>PathPolicy: resolved path
  PathPolicy-->>validate_mounts: validation result

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🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: validating host paths and container mounts.
Linked Issues check	✅ Passed	The changes implement the requested security layer for path validation, mount parsing, internal mount handling, and runtime socket blocking.
Out of Scope Changes check	✅ Passed	The PR stays within the security validation scope and does not introduce unrelated changes.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch codex/issue-7-security-validation

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[chatgpt-codex-connector]

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