A C++ tool that writes random data into open file descriptors of targeted Linux processes, using the pidfd_open and pidfd_getfd system calls.
Useful for testing, fuzzing, or demonstrating concepts related to file descriptors and processes.
- Features
- Requirements
- Compilation
- Usage
- Detailed Options
- Examples
- Important Notes
- Limitations and Security
- License
- Lists open files for one or multiple specified PIDs, or for all processes on the system.
- Uses modern Linux system calls
pidfd_openandpidfd_getfd(Linux kernel 5.6+). - Sends random-sized data to each file descriptor.
- Supports repeated sending in a loop with configurable delay.
- Ignores SIGPIPE signals to prevent crashes on broken pipes.
- Debug mode with detailed logs.
- Built-in help with
-hor--help.
- Linux kernel 5.6 or newer (for
pidfd_openandpidfd_getfdsupport). - C++17 compiler (e.g., g++ 7 or later).
- Sufficient privileges to access other processes’ file descriptors (usually root).
g++ -std=c++17 -O2 -o fault fault.cppOr
makesudo ./fault <pid[,pid2,...]> [options]
sudo ./fault --lol [options]<pid[,pid2,...]>: comma-separated list of PIDs to target.--lol: target all processes on the system.
| Option | Description | Default |
|---|---|---|
--min N |
Minimum size of random data sent (bytes) | 1 |
--max N |
Maximum size of random data sent (bytes) | 1048576 (1 MiB) |
--limit N |
Maximum number of iterations (loops) | Unlimited |
--delay S |
Delay between each iteration (seconds) | 0 (no delay) |
--debug |
Enable detailed debug output | Disabled |
-h, --help |
Show help message | N/A |
- Target PIDs
1234and5678, send between 10 and 4096 bytes, repeat 10 times, with 0.5 seconds delay, debug enabled:
sudo ./fault 1234,5678 --min 10 --max 4096 --limit 10 --delay 0.5 --debug- Target all processes on the system, unlimited loops, no delay, silent mode:
sudo ./fault --lol- Show help:
./fault --help- Privileges: Accessing other processes’ file descriptors usually requires root or special capabilities.
- Security: This tool can write into file descriptors of other processes, potentially causing unexpected behavior, crashes, or corruption. Use with caution.
- Compatibility: Requires Linux kernel 5.6+ with
pidfd_openandpidfd_getfdsupport. - SIGPIPE Signal: Ignored globally to prevent the program from crashing on writing to closed pipes.
- Intended for experimental or testing use in controlled environments only.