tests/fuzzers/abi: add fuzzer for fuzzing package accounts/abi (#21217)

* tests/fuzzers/abi: added abi fuzzer

* accounts/abi: fixed issues found by fuzzing

* tests/fuzzers/abi: update fuzzers, added repro test

* tests/fuzzers/abi: renamed abi_fuzzer to abifuzzer

* tests/fuzzers/abi: updated abi fuzzer

* tests/fuzzers/abi: updated abi fuzzer

* accounts/abi: minor style fix

* go.mod: added go-fuzz dependency

* tests/fuzzers/abi: updated abi fuzzer

* tests/fuzzers/abi: make linter happy

* tests/fuzzers/abi: make linter happy

* tests/fuzzers/abi: comment out false positives

accounts/abi/abi_test.go

@@ -33,7 +33,7 @@ import (
 
 const jsondata = `
 [
-	{ "type" : "function", "name" : "", "stateMutability" : "view" },
+	{ "type" : "function", "name" : ""},
 	{ "type" : "function", "name" : "balance", "stateMutability" : "view" },
 	{ "type" : "function", "name" : "send", "inputs" : [ { "name" : "amount", "type" : "uint256" } ] },
 	{ "type" : "function", "name" : "test", "inputs" : [ { "name" : "number", "type" : "uint32" } ] },
@@ -88,7 +88,7 @@ var (
 )
 
 var methods = map[string]Method{
-	"":                    NewMethod("", "", Function, "view", false, false, nil, nil),
+	"":                    NewMethod("", "", Function, "", false, false, nil, nil),
 	"balance":             NewMethod("balance", "balance", Function, "view", false, false, nil, nil),
 	"send":                NewMethod("send", "send", Function, "", false, false, []Argument{{"amount", Uint256, false}}, nil),
 	"test":                NewMethod("test", "test", Function, "", false, false, []Argument{{"number", Uint32, false}}, nil),

accounts/abi/error.go

@@ -52,7 +52,7 @@ func sliceTypeCheck(t Type, val reflect.Value) error {
 		}
 	}
 
-	if elemKind := val.Type().Elem().Kind(); elemKind != t.Elem.GetType().Kind() {
+	if val.Type().Elem().Kind() != t.Elem.GetType().Kind() {
 		return typeErr(formatSliceString(t.Elem.GetType().Kind(), t.Size), val.Type())
 	}
 	return nil

accounts/abi/pack.go

@@ -17,6 +17,8 @@
 package abi
 
 import (
+	"errors"
+	"fmt"
 	"math/big"
 	"reflect"
 
@@ -33,35 +35,38 @@ func packBytesSlice(bytes []byte, l int) []byte {
 
 // packElement packs the given reflect value according to the abi specification in
 // t.
-func packElement(t Type, reflectValue reflect.Value) []byte {
+func packElement(t Type, reflectValue reflect.Value) ([]byte, error) {
 	switch t.T {
 	case IntTy, UintTy:
-		return packNum(reflectValue)
+		return packNum(reflectValue), nil
 	case StringTy:
-		return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len())
+		return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len()), nil
 	case AddressTy:
 		if reflectValue.Kind() == reflect.Array {
 			reflectValue = mustArrayToByteSlice(reflectValue)
 		}
 
-		return common.LeftPadBytes(reflectValue.Bytes(), 32)
+		return common.LeftPadBytes(reflectValue.Bytes(), 32), nil
 	case BoolTy:
 		if reflectValue.Bool() {
-			return math.PaddedBigBytes(common.Big1, 32)
+			return math.PaddedBigBytes(common.Big1, 32), nil
 		}
-		return math.PaddedBigBytes(common.Big0, 32)
+		return math.PaddedBigBytes(common.Big0, 32), nil
 	case BytesTy:
 		if reflectValue.Kind() == reflect.Array {
 			reflectValue = mustArrayToByteSlice(reflectValue)
 		}
-		return packBytesSlice(reflectValue.Bytes(), reflectValue.Len())
+		if reflectValue.Type() != reflect.TypeOf([]byte{}) {
+			return []byte{}, errors.New("Bytes type is neither slice nor array")
+		}
+		return packBytesSlice(reflectValue.Bytes(), reflectValue.Len()), nil
 	case FixedBytesTy, FunctionTy:
 		if reflectValue.Kind() == reflect.Array {
 			reflectValue = mustArrayToByteSlice(reflectValue)
 		}
-		return common.RightPadBytes(reflectValue.Bytes(), 32)
+		return common.RightPadBytes(reflectValue.Bytes(), 32), nil
 	default:
-		panic("abi: fatal error")
+		return []byte{}, fmt.Errorf("Could not pack element, unknown type: %v", t.T)
 	}
 }
 

accounts/abi/type.go

@@ -346,7 +346,7 @@ func (t Type) pack(v reflect.Value) ([]byte, error) {
 		return append(ret, tail...), nil
 
 	default:
-		return packElement(t, v), nil
+		return packElement(t, v)
 	}
 }
 

accounts/abi/unpack.go

@@ -224,7 +224,10 @@ func toGoType(index int, t Type, output []byte) (interface{}, error) {
 		return forEachUnpack(t, output[begin:], 0, length)
 	case ArrayTy:
 		if isDynamicType(*t.Elem) {
-			offset := int64(binary.BigEndian.Uint64(returnOutput[len(returnOutput)-8:]))
+			offset := binary.BigEndian.Uint64(returnOutput[len(returnOutput)-8:])
+			if offset > uint64(len(output)) {
+				return nil, fmt.Errorf("abi: toGoType offset greater than output length: offset: %d, len(output): %d", offset, len(output))
+			}
 			return forEachUnpack(t, output[offset:], 0, t.Size)
 		}
 		return forEachUnpack(t, output[index:], 0, t.Size)

go.mod

@@ -18,6 +18,7 @@ require (
 	github.com/dlclark/regexp2 v1.2.0 // indirect
 	github.com/docker/docker v1.4.2-0.20180625184442-8e610b2b55bf
 	github.com/dop251/goja v0.0.0-20200721192441-a695b0cdd498
+	github.com/dvyukov/go-fuzz v0.0.0-20200318091601-be3528f3a813 // indirect
 	github.com/edsrzf/mmap-go v0.0.0-20160512033002-935e0e8a636c
 	github.com/fatih/color v1.3.0
 	github.com/fjl/memsize v0.0.0-20180418122429-ca190fb6ffbc
@@ -27,6 +28,7 @@ require (
 	github.com/go-stack/stack v1.8.0
 	github.com/golang/protobuf v1.4.2
 	github.com/golang/snappy v0.0.2-0.20200707131729-196ae77b8a26
+	github.com/google/gofuzz v1.1.1-0.20200604201612-c04b05f3adfa
 	github.com/gorilla/websocket v1.4.1-0.20190629185528-ae1634f6a989
 	github.com/graph-gophers/graphql-go v0.0.0-20191115155744-f33e81362277
 	github.com/hashicorp/golang-lru v0.5.4

go.sum

@@ -59,6 +59,8 @@ github.com/docker/docker v1.4.2-0.20180625184442-8e610b2b55bf h1:sh8rkQZavChcmak
 github.com/docker/docker v1.4.2-0.20180625184442-8e610b2b55bf/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
 github.com/dop251/goja v0.0.0-20200721192441-a695b0cdd498 h1:Y9vTBSsV4hSwPSj4bacAU/eSnV3dAxVpepaghAdhGoQ=
 github.com/dop251/goja v0.0.0-20200721192441-a695b0cdd498/go.mod h1:Mw6PkjjMXWbTj+nnj4s3QPXq1jaT0s5pC0iFD4+BOAA=
+github.com/dvyukov/go-fuzz v0.0.0-20200318091601-be3528f3a813 h1:NgO45/5mBLRVfiXerEFzH6ikcZ7DNRPS639xFg3ENzU=
+github.com/dvyukov/go-fuzz v0.0.0-20200318091601-be3528f3a813/go.mod h1:11Gm+ccJnvAhCNLlf5+cS9KjtbaD5I5zaZpFMsTHWTw=
 github.com/edsrzf/mmap-go v0.0.0-20160512033002-935e0e8a636c h1:JHHhtb9XWJrGNMcrVP6vyzO4dusgi/HnceHTgxSejUM=
 github.com/edsrzf/mmap-go v0.0.0-20160512033002-935e0e8a636c/go.mod h1:YO35OhQPt3KJa3ryjFM5Bs14WD66h8eGKpfaBNrHW5M=
 github.com/fatih/color v1.3.0 h1:YehCCcyeQ6Km0D6+IapqPinWBK6y+0eB5umvZXK9WPs=
@@ -99,6 +101,10 @@ github.com/google/go-cmp v0.3.1 h1:Xye71clBPdm5HgqGwUkwhbynsUJZhDbS20FvLhQ2izg=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/gofuzz v1.1.0 h1:Hsa8mG0dQ46ij8Sl2AYJDUv1oA9/d6Vk+3LG99Oe02g=
+github.com/google/gofuzz v1.1.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/google/gofuzz v1.1.1-0.20200604201612-c04b05f3adfa h1:Q75Upo5UN4JbPFURXZ8nLKYUvF85dyFRop/vQ0Rv+64=
+github.com/google/gofuzz v1.1.1-0.20200604201612-c04b05f3adfa/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/gorilla/websocket v1.4.1-0.20190629185528-ae1634f6a989 h1:giknQ4mEuDFmmHSrGcbargOuLHQGtywqo4mheITex54=
 github.com/gorilla/websocket v1.4.1-0.20190629185528-ae1634f6a989/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
 github.com/graph-gophers/graphql-go v0.0.0-20191115155744-f33e81362277 h1:E0whKxgp2ojts0FDgUA8dl62bmH0LxKanMoBr6MDTDM=

tests/fuzzers/abi/abifuzzer.go

@@ -0,0 +1,186 @@
+// Copyright 2020 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"bytes"
+	"fmt"
+	"math/rand"
+	"reflect"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/ethereum/go-ethereum/crypto"
+	fuzz "github.com/google/gofuzz"
+)
+
+func unpackPack(abi abi.ABI, method string, inputType []interface{}, input []byte) bool {
+	outptr := reflect.New(reflect.TypeOf(inputType))
+	if err := abi.Unpack(outptr.Interface(), method, input); err == nil {
+		output, err := abi.Pack(method, input)
+		if err != nil {
+			// We have some false positives as we can unpack these type successfully, but not pack them
+			if err.Error() == "abi: cannot use []uint8 as type [0]int8 as argument" ||
+				err.Error() == "abi: cannot use uint8 as type int8 as argument" {
+				return false
+			}
+			panic(err)
+		}
+		if !bytes.Equal(input, output[4:]) {
+			panic(fmt.Sprintf("unpackPack is not equal, \ninput : %x\noutput: %x", input, output[4:]))
+		}
+		return true
+	}
+	return false
+}
+
+func packUnpack(abi abi.ABI, method string, input []interface{}) bool {
+	if packed, err := abi.Pack(method, input); err == nil {
+		outptr := reflect.New(reflect.TypeOf(input))
+		err := abi.Unpack(outptr.Interface(), method, packed)
+		if err != nil {
+			panic(err)
+		}
+		out := outptr.Elem().Interface()
+		if !reflect.DeepEqual(input, out) {
+			panic(fmt.Sprintf("unpackPack is not equal, \ninput : %x\noutput: %x", input, out))
+		}
+		return true
+	}
+	return false
+}
+
+type args struct {
+	name string
+	typ  string
+}
+
+func createABI(name string, stateMutability, payable *string, inputs []args) (abi.ABI, error) {
+	sig := fmt.Sprintf(`[{ "type" : "function", "name" : "%v" `, name)
+	if stateMutability != nil {
+		sig += fmt.Sprintf(`, "stateMutability": "%v" `, *stateMutability)
+	}
+	if payable != nil {
+		sig += fmt.Sprintf(`, "payable": %v `, *payable)
+	}
+	if len(inputs) > 0 {
+		sig += `, "inputs" : [ {`
+		for i, inp := range inputs {
+			sig += fmt.Sprintf(`"name" : "%v", "type" : "%v" `, inp.name, inp.typ)
+			if i+1 < len(inputs) {
+				sig += ","
+			}
+		}
+		sig += "} ]"
+		sig += `, "outputs" : [ {`
+		for i, inp := range inputs {
+			sig += fmt.Sprintf(`"name" : "%v", "type" : "%v" `, inp.name, inp.typ)
+			if i+1 < len(inputs) {
+				sig += ","
+			}
+		}
+		sig += "} ]"
+	}
+	sig += `}]`
+
+	return abi.JSON(strings.NewReader(sig))
+}
+
+func fillStruct(structs []interface{}, data []byte) {
+	if structs != nil && len(data) != 0 {
+		fuzz.NewFromGoFuzz(data).Fuzz(&structs)
+	}
+}
+
+func createStructs(args []args) []interface{} {
+	structs := make([]interface{}, len(args))
+	for i, arg := range args {
+		t, err := abi.NewType(arg.typ, "", nil)
+		if err != nil {
+			panic(err)
+		}
+		structs[i] = reflect.New(t.GetType()).Elem()
+	}
+	return structs
+}
+
+func runFuzzer(input []byte) int {
+	good := false
+
+	names := []string{"_name", "name", "NAME", "name_", "__", "_name_", "n"}
+	stateMut := []string{"", "pure", "view", "payable"}
+	stateMutabilites := []*string{nil, &stateMut[0], &stateMut[1], &stateMut[2], &stateMut[3]}
+	pays := []string{"true", "false"}
+	payables := []*string{nil, &pays[0], &pays[1]}
+	varNames := []string{"a", "b", "c", "d", "e", "f", "g"}
+	varNames = append(varNames, names...)
+	varTypes := []string{"bool", "address", "bytes", "string",
+		"uint8", "int8", "uint8", "int8", "uint16", "int16",
+		"uint24", "int24", "uint32", "int32", "uint40", "int40", "uint48", "int48", "uint56", "int56",
+		"uint64", "int64", "uint72", "int72", "uint80", "int80", "uint88", "int88", "uint96", "int96",
+		"uint104", "int104", "uint112", "int112", "uint120", "int120", "uint128", "int128", "uint136", "int136",
+		"uint144", "int144", "uint152", "int152", "uint160", "int160", "uint168", "int168", "uint176", "int176",
+		"uint184", "int184", "uint192", "int192", "uint200", "int200", "uint208", "int208", "uint216", "int216",
+		"uint224", "int224", "uint232", "int232", "uint240", "int240", "uint248", "int248", "uint256", "int256",
+		"bytes1", "bytes2", "bytes3", "bytes4", "bytes5", "bytes6", "bytes7", "bytes8", "bytes9", "bytes10", "bytes11",
+		"bytes12", "bytes13", "bytes14", "bytes15", "bytes16", "bytes17", "bytes18", "bytes19", "bytes20", "bytes21",
+		"bytes22", "bytes23", "bytes24", "bytes25", "bytes26", "bytes27", "bytes28", "bytes29", "bytes30", "bytes31",
+		"bytes32", "bytes"}
+	rnd := rand.New(rand.NewSource(123456))
+	if len(input) > 0 {
+		kec := crypto.Keccak256(input)
+		rnd = rand.New(rand.NewSource(int64(kec[0])))
+	}
+	name := names[rnd.Intn(len(names))]
+	stateM := stateMutabilites[rnd.Intn(len(stateMutabilites))]
+	payable := payables[rnd.Intn(len(payables))]
+	maxLen := 5
+	for k := 1; k < maxLen; k++ {
+		var arg []args
+		for i := k; i > 0; i-- {
+			argName := varNames[i]
+			argTyp := varTypes[rnd.Int31n(int32(len(varTypes)))]
+			if rnd.Int31n(10) == 0 {
+				argTyp += "[]"
+			} else if rnd.Int31n(10) == 0 {
+				arrayArgs := rnd.Int31n(30) + 1
+				argTyp += fmt.Sprintf("[%d]", arrayArgs)
+			}
+			arg = append(arg, args{
+				name: argName,
+				typ:  argTyp,
+			})
+		}
+		abi, err := createABI(name, stateM, payable, arg)
+		if err != nil {
+			continue
+		}
+		structs := createStructs(arg)
+		b := unpackPack(abi, name, structs, input)
+		fillStruct(structs, input)
+		c := packUnpack(abi, name, structs)
+		good = good || b || c
+	}
+	if good {
+		return 1
+	}
+	return 0
+}
+
+func Fuzz(input []byte) int {
+	return runFuzzer(input)
+}

tests/fuzzers/abi/abifuzzer_test.go

@@ -0,0 +1,50 @@
+// Copyright 2020 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"testing"
+)
+
+// TestReplicate can be used to replicate crashers from the fuzzing tests.
+// Just replace testString with the data in .quoted
+func TestReplicate(t *testing.T) {
+	testString := "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" +
+		"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00 \x00\x00\x00\x00\x00\x00\x00\x00" +
+		"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" +
+		"\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00000000000" +
+		"00000000000000000000" +
+		"00000000000000000000" +
+		"00000001"
+
+	data := []byte(testString)
+	runFuzzer(data)
+}
+
+// TestGenerateCorpus can be used to add corpus for the fuzzer.
+// Just replace corpusHex with the hexEncoded output you want to add to the fuzzer.
+func TestGenerateCorpus(t *testing.T) {
+	/*
+		corpusHex := "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
+		data := common.FromHex(corpusHex)
+		checksum := sha1.Sum(data)
+		outf := fmt.Sprintf("corpus/%x", checksum)
+		if err := ioutil.WriteFile(outf, data, 0777); err != nil {
+			panic(err)
+		}
+	*/
+}