Merge pull request opencontainers#2841 from AdamKorcz/fuzz1

tests: Move fuzzers upstream

libcontainer/configs/configs_fuzzer.go

@@ -0,0 +1,9 @@
+// +build gofuzz
+
+package configs
+
+func FuzzUnmarshalJSON(data []byte) int {
+	hooks := Hooks{}
+	_ = hooks.UnmarshalJSON(data)
+	return 1
+}

libcontainer/system/system_fuzzer.go

@@ -0,0 +1,15 @@
+// +build gofuzz
+
+package system
+
+import (
+	"strings"
+
+	"github.com/opencontainers/runc/libcontainer/user"
+)
+
+func FuzzUIDMap(data []byte) int {
+	uidmap, _ := user.ParseIDMap(strings.NewReader(string(data)))
+	_ = UIDMapInUserNS(uidmap)
+	return 1
+}

libcontainer/user/user_fuzzer.go

@@ -0,0 +1,42 @@
+// +build gofuzz
+
+package user
+
+import (
+	"io"
+	"strings"
+)
+
+func IsDivisbleBy(n int, divisibleby int) bool {
+	return (n % divisibleby) == 0
+}
+
+func FuzzUser(data []byte) int {
+	if len(data) == 0 {
+		return -1
+	}
+	if !IsDivisbleBy(len(data), 5) {
+		return -1
+	}
+
+	var divided [][]byte
+
+	chunkSize := len(data) / 5
+
+	for i := 0; i < len(data); i += chunkSize {
+		end := i + chunkSize
+
+		divided = append(divided, data[i:end])
+	}
+
+	_, _ = ParsePasswdFilter(strings.NewReader(string(divided[0])), nil)
+
+	var passwd, group io.Reader
+
+	group = strings.NewReader(string(divided[1]))
+	_, _ = GetAdditionalGroups([]string{string(divided[2])}, group)
+
+	passwd = strings.NewReader(string(divided[3]))
+	_, _ = GetExecUser(string(divided[4]), nil, passwd, group)
+	return 1
+}

tests/fuzzing/oss_fuzz_build.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+# This file is only meant to be run by OSS-fuzz and will not work
+# if run outside of it.
+# The api, compile_go_fuzzer() is provided by the OSS-fuzz
+# environment and is a high level helper function for a series
+# of compilation and linking steps to build the fuzzers in the 
+# OSS-fuzz environment.
+# More info about compile_go_fuzzer() can be found here:
+#     https://google.github.io/oss-fuzz/getting-started/new-project-guide/go-lang/#buildsh
+compile_go_fuzzer ./libcontainer/system FuzzUIDMap id_map_fuzzer linux
+compile_go_fuzzer ./libcontainer/user FuzzUser user_fuzzer
+compile_go_fuzzer ./libcontainer/configs FuzzUnmarshalJSON configs_fuzzer