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Diffstat (limited to 'docs/internals.md')
| -rw-r--r-- | docs/internals.md | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/docs/internals.md b/docs/internals.md index c672e04e7..0697c887f 100644 --- a/docs/internals.md +++ b/docs/internals.md @@ -1,7 +1,8 @@ # How syzkaller works -Below is the generic descriptions of how syzkaller works. -Check [this](linux/internals.md) for Linux kernel specific things. +Generic description of how syzkaller works are [below](internals.md#overview). + +Linux kernel specific internals can be found [here](linux/internals.md). ## Overview @@ -11,11 +12,11 @@ red labels indicate corresponding configuration options.  The `syz-manager` process starts, monitors and restarts several VM instances, and starts a `syz-fuzzer` process inside of the VMs. -It is responsible for persistent corpus and crash storage. -As opposed to `syz-fuzzer` processes, it runs on a host with stable kernel which does not experience white-noise fuzzer load. +`syz-manager` is responsible for persistent corpus and crash storage. +It runs on a host with stable kernel which does not experience white-noise fuzzer load. The `syz-fuzzer` process runs inside of presumably unstable VMs. -The `syz-fuzzer` guides fuzzing process itself (input generation, mutation, minimization, etc) and sends inputs that trigger new coverage back to the `syz-manager` process via RPC. +The `syz-fuzzer` guides fuzzing process (input generation, mutation, minimization, etc.) and sends inputs that trigger new coverage back to the `syz-manager` process via RPC. It also starts transient `syz-executor` processes. Each `syz-executor` process executes a single input (a sequence of syscalls). @@ -26,6 +27,10 @@ It is designed to be as simple as possible (to not interfere with fuzzing proces The `syz-fuzzer` process generates programs to be executed by `syz-executor` based on syscall descriptions described [here](syscall_descriptions.md). +## Coverage + +Syzkaller is a coverage-guided fuzzer. The details about coverage collection can be found [here](coverage.md). + ## Crash reports When `syzkaller` finds a crasher, it saves information about it into `workdir/crashes` directory. @@ -48,7 +53,7 @@ and up to 100 `logN` and `reportN` files, one pair per test machine crash: ... ``` -Descriptions are extracted using a set of [regular expressions](/pkg/report/report.go#L33). +Descriptions are extracted using a set of [regular expressions](/pkg/report/). This set may need to be extended if you are using a different kernel architecture, or are just seeing a previously unseen kernel error messages. `logN` files contain raw `syzkaller` logs and include kernel console output as well as programs executed before the crash. @@ -69,7 +74,3 @@ However, frequently they mean a kernel lockup or something similarly bad (here a [1](https://groups.google.com/d/msg/syzkaller/zfuHHRXL7Zg/Tc5rK8bdCAAJ), [2](https://groups.google.com/d/msg/syzkaller/kY_ml6TCm9A/wDd5fYFXBQAJ), [3](https://groups.google.com/d/msg/syzkaller/OM7CXieBCoY/etzvFPX3AQAJ)). - -## Coverage - -Syzkaller coverage description can be found from [here](coverage.md). |