FFIChecker: A Static Analysis Tool For Detecting Memory Management Bugs Between Rust and C/C++

This tool generates and analyzes LLVM bitcode to detect potential bugs caused by incorrect use of Rust FFI.

Information about bugs detected by this tool are listed in Trophy Case.

Requirements

• Rust nightly, as specified in rust-toolchain.

• rustc-dev and llvm-tools-preview:

  $ rustup component add rustc-dev llvm-tools-preview

• LLVM 13:

  # Some required libraries are included in 'libclang-common-13-dev'
  $ sudo apt-get install llvm-13-dev libclang-common-13-dev

Build

1. Clone the repository

   $ git clone https://github.com/lizhuohua/rust-ffi-checker.git
   
   $ cd rust-ffi-checker

2. Build & Install

   # You can build and install the cargo subcommand:
   $ cargo install --path .
   
   # Or, you can only build the checker itself:
   $ cargo build

Example

The following is a contrived example which contains a use-after-free bug. For more examples, please see examples and trophy-case.

use libc::{c_void, free};

fn main() {
    let mut n = Box::new(1);
    unsafe {
        free(&mut *n as *const _ as *mut c_void);
    }

    *n = 2;
}

It compiles but will crash at runtime. Our checker can detect it at compile time.

Usage

Before using this tool, make sure your Rust project compiles without any errors or warnings.

# If you have installed the cargo subcommand:
$ cargo clean; cargo ffi-checker

# Or, you can directly run the checker binary
$ cargo clean; path/to/cargo-ffi-checker ffi-checker

You can also set the threshold of warnings to filter out false positives.

# Only output warnings with at least medium severity
# Available options: "high", "mid", and "low"
$ cargo clean; cargo ffi-checker -- --precision_filter mid

Debug

Set RUST_LOG environment variable to enable logging:

# Enable all logging
$ export RUST_LOG=rust_ffi_checker

# Can also set logging level
$ export RUST_LOG=rust_ffi_checker=debug

For more settings, please see the documents of env_logger.

Troubleshooting

For macOS, you may encounter dyld: Library not loaded error, try setting:

$ export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$LD_LIBRARY_PATH

License

See LICENSE