AD5020: RustEnableSanitizersMachO¶

Summary¶

Property	Value
ID	AD5020
Name	RustEnableSanitizersMachO
Category	Security
Severity	Note
Applies to	Mach-O (macOS, iOS)

Description¶

Rust Mach-O binaries used for testing should consider using sanitizers to detect memory safety issues in unsafe code and FFI.

Note: This is an informational rule. Sanitizers are for development and testing.

How It Works¶

The rule checks for sanitizer runtime symbols:

AddressSanitizer (__asan_*) symbols
ThreadSanitizer (__tsan_*) symbols
UndefinedBehaviorSanitizer runtime

Why This Matters¶

While Rust provides memory safety for safe code, unsafe blocks and C/C++ FFI can introduce bugs that sanitizers catch.

Sanitizer Support in Rust¶

Sanitizer	macOS Support	Use Case
ASAN	Yes	Memory errors
TSAN	Yes	Data races
MSAN	No	Uninitialized memory
LSAN	With ASAN	Memory leaks

Unsafe Code Coverage¶

unsafe {
    // This code bypasses Rust's safety guarantees
    // Sanitizers can catch bugs here
    let ptr = libc::malloc(100);
    std::ptr::write(ptr as *mut u8, 42);
    libc::free(ptr);
    // ASAN would catch use-after-free here:
    // std::ptr::read(ptr as *mut u8);
}

FFI Considerations¶

FFI Pattern	Risk	Sanitizer
C library calls	Memory errors	ASAN
Shared mutable state	Data races	TSAN
Custom allocators	Memory leaks	LSAN

Resolution¶

Enable sanitizers in test builds:

# Nightly Rust with ASAN
RUSTFLAGS="-Zsanitizer=address" cargo +nightly build --target aarch64-apple-darwin

# Run tests with sanitizer
RUSTFLAGS="-Zsanitizer=address" cargo +nightly test

Build Configuration¶

# .cargo/config.toml
[target.aarch64-apple-darwin]
rustflags = ["-Zsanitizer=address"]

[target.x86_64-apple-darwin]
rustflags = ["-Zsanitizer=address"]