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Joachim Wiberg
c28acf21a1
__msg_parse() turns bytes off a socket into pointers, before anything has vouched for the peer, and it is the only place in libink that does. It had no test of its own beyond whatever the other tests happened to send it, all of it well-formed. The target checks the parser's contract, not merely that it survived. A header field must point into the header field array, and terminate inside it, and the parse must never claim more bytes than it was handed. Crash-only would pass a parser that walked into the body and returned fields from there, since those bytes were handed over too. The expected bounds are derived from the raw header rather than from the parser, so the two have to agree independently. Every input is copied into an allocation sized to it first. Reading past the end of a roomy buffer stays inside the allocation and the sanitizer never sees it; against an exact one the same read is a fault, which is where the sharpest findings come from. Under libFuzzer it is an ordinary fuzz target and named files replay, which is how a find gets reproduced. With no arguments it runs a fixed sweep -- every truncation, every single-byte corruption, every value of the length that decides where the header ends, and seeded garbage -- so the suite covers the same contract on every build, without clang or a corpus in the tree. It takes 40 ms. CI fuzzes it properly on every pull request, keeps the crashers, and carries the corpus between runs so it reaches deeper over time than any single run can. Note that clang links the fuzzer runtime against the newest GCC tree it finds, so the libstdc++ headers have to match that one and not the default compiler, which is worth saying since installing the obvious package leaves you exactly where you started. Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Introduction
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Reverse engineered from the EeePC fastinit
"gaps filled with frog DNA …"
— Claudio Matsuoka
Finit is a process starter and supervisor designed to run as PID 1 on Linux systems. It consists of a set of plugins and can be set up using configuration files. Plugins start at hook points and can run various set up tasks and/or install event handlers that later provide runtime services, e.g., PID file monitoring, or conditions.
Features
- Runlevels, defined per service
- One-shot tasks, services (daemons), or SysV init start/stop scripts
- Runparts and
/etc/rc.localsupport - Process supervision similar to systemd
- Fine-grained privilege control:
- Linux capabilities for minimal required privileges
- Supplementary groups for multi-group resource access
- Sourcing environment files
- Conditions for network/process/custom dependencies
- Readiness notification; PID files (native) for synchronizing system startup, support for systemd sd_notify(), or s6 style too
- Limited support for tmpfiles.d(5) (no aging, attributes, or subvolumes)
- Pre/Post script actions
- Rudimentary templating support
- Tooling to enable/disable services
- Automatic reload of modified configuration files (optional)
- Built-in getty
- Built-in watchdog, with support for hand-over to watchdogd
- Built-in support for Debian/BusyBox
/etc/network/interfaces - Cgroups v2, both configuration and monitoring in
initctl top - Plugin support for customization
- Proper rescue mode with bundled
suloginfor protected maintenance shell - Switch root support for initramfs-to-real-root transitions
- Integration with watchdogd for full system supervision
- Logging to kernel ring buffer before
syslogdhas started, see the recommended sysklogd project for complete logging integration and how to log to the kernel ring buffer from scripts usinglogger
For a more thorough overview, see the Features section.
Tip
See SysV Init Compatibility for help to quickly get going with an existing SysV or BusyBox init setup.
Origin
This project is based on the original finit by Claudio Matsuoka which was reverse engineered from syscalls of the EeePC fastinit.
Finit is developed and maintained by Joachim Wiberg at GitHub. Please file bug reports, clone it, or send pull requests for bug fixes and proposed extensions.