Rust Safety

Overview

This skill provides a checklist and best practices for ensuring Rust code is secure, robust, and free from common vulnerabilities. While Rust provides strong safety guarantees, logic errors, unsafe blocks, and dependency risks still require careful attention.

Security Checklist

1. Memory Safety & unsafe

• Minimize unsafe: Always look for safe alternatives first.
• Audit unsafe blocks: Ensure they uphold safety invariants. Use miri for testing.
• Avoid raw pointers: Prefer references or smart pointers (Box, Rc, Arc).

2. Integer & Arithmetic Safety

• Overflows: Be cautious with arithmetic operations. Use checked_, saturating_, or wrapping_ methods where appropriate.
• Casting: Use try_from instead of as when lossy conversions could lead to security issues.

3. Error Handling

• No unwrap()/expect(): Use proper error handling (Result, Option) in production code. Avoid panicking in libraries.
• Sensitive Data: Ensure error messages do not leak sensitive information (e.g., file paths, internal state).

4. Dependency Management

• Audit dependencies: Use cargo audit to check for known vulnerabilities.
• Pin versions: Be careful with * or wide version ranges in Cargo.toml.
• Minimal dependencies: Only include what is strictly necessary.

5. Concurrency

• Deadlocks: Ensure lock ordering is consistent.
• Shared State: Use Arc<Mutex<T>> or Arc<RwLock<T>> correctly, and keep critical sections small.

Tools

• cargo audit: Audit dependencies for crates.io vulnerabilities.
• cargo clippy: Linter for catching common mistakes and non-idiomatic code.
• miri: An interpreter for Rust's mid-level intermediate representation, capable of detecting many types of undefined behavior.