From 91a6a12dbeea3169ed03355a3203e6af9a589ded Mon Sep 17 00:00:00 2001
From: Catena cyber <35799796+catenacyber@users.noreply.github.com>
Date: Sun, 22 Nov 2020 20:05:32 +0100
Subject: [PATCH] Go json coverage (#4689)

* Good fuzz target for golang coverage with modules

* Place target in right directory for go-json-iterator

So that coverage gets access to the right package
---
 infra/base-images/base-builder/compile_go_fuzzer |  8 +++++++-
 projects/go-json-iterator/Dockerfile             |  4 +---
 projects/go-json-iterator/build.sh               |  3 +--
 projects/go-json-iterator/fuzz_json.go           | 13 ++++++-------
 4 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/infra/base-images/base-builder/compile_go_fuzzer b/infra/base-images/base-builder/compile_go_fuzzer
index 0abd2c07e..925a29ec0 100755
--- a/infra/base-images/base-builder/compile_go_fuzzer
+++ b/infra/base-images/base-builder/compile_go_fuzzer
@@ -38,7 +38,13 @@ if [[ $SANITIZER = *coverage* ]]; then
   sed -i -e 's/TestFuzzCorpus/Test'$function'Corpus/' ./"${function,,}"_test.go
 
   echo "#/bin/sh" > $OUT/$fuzzer
-  echo "cd $path" >> $OUT/$fuzzer
+  if [[ ${GO111MODULE:-} = on ]]; then
+    echo "export GO111MODULE=on" >> $OUT/$fuzzer
+    echo "cd ../pkg/mod/"`go list -m $basemod | sed 's/ /@/'` >> $OUT/$fuzzer
+    echo "cd ./"`echo $path | cut -d/ -f4-` >> $OUT/$fuzzer
+  else
+    echo "cd $path" >> $OUT/$fuzzer
+  fi
   echo "go test -run Test${function}Corpus -v $tags -coverprofile \$1 " >> $OUT/$fuzzer
   chmod +x $OUT/$fuzzer
 
diff --git a/projects/go-json-iterator/Dockerfile b/projects/go-json-iterator/Dockerfile
index bcbb635f8..3d6a90c56 100644
--- a/projects/go-json-iterator/Dockerfile
+++ b/projects/go-json-iterator/Dockerfile
@@ -17,7 +17,5 @@
 FROM gcr.io/oss-fuzz-base/base-builder
 RUN go get github.com/json-iterator/go
 
-RUN mkdir fuzz
-COPY fuzz_json.go fuzz
+COPY fuzz_json.go $GOPATH/src/github.com/json-iterator/go/
 COPY build.sh $SRC/
-WORKDIR fuzz
diff --git a/projects/go-json-iterator/build.sh b/projects/go-json-iterator/build.sh
index 060bb7c76..f247b2422 100755
--- a/projects/go-json-iterator/build.sh
+++ b/projects/go-json-iterator/build.sh
@@ -16,5 +16,4 @@
 ################################################################################
 
 
-
-compile_go_fuzzer . Fuzz fuzz_json
+compile_go_fuzzer github.com/json-iterator/go Fuzz fuzz_json
diff --git a/projects/go-json-iterator/fuzz_json.go b/projects/go-json-iterator/fuzz_json.go
index c057a63bf..e5236be2e 100644
--- a/projects/go-json-iterator/fuzz_json.go
+++ b/projects/go-json-iterator/fuzz_json.go
@@ -2,12 +2,11 @@
 // Use of this source code is governed by Apache 2 LICENSE.
 // Modified from original file https://github.com/dvyukov/go-fuzz-corpus/blob/master/json/json.go
 
-package jsonfuzz
+package jsoniter
 
 import (
 	"encoding/json"
 	"fmt"
-	jsoniter "github.com/json-iterator/go"
 	"reflect"
 )
 
@@ -21,7 +20,7 @@ func Fuzz(data []byte) int {
 		func() interface{} { return new(S) },
 	} {
 		v := ctor()
-		if jsoniter.ConfigCompatibleWithStandardLibrary.Unmarshal(data, v) != nil {
+		if ConfigCompatibleWithStandardLibrary.Unmarshal(data, v) != nil {
 			continue
 		}
 		score = 1
@@ -36,12 +35,12 @@ func Fuzz(data []byte) int {
 			panic("not equal")
 		}
 
-		data1, err := jsoniter.ConfigCompatibleWithStandardLibrary.Marshal(v)
+		data1, err := ConfigCompatibleWithStandardLibrary.Marshal(v)
 		if err != nil {
 			panic(err)
 		}
 		v1 := ctor()
-		if jsoniter.ConfigCompatibleWithStandardLibrary.Unmarshal(data1, v1) != nil {
+		if ConfigCompatibleWithStandardLibrary.Unmarshal(data1, v1) != nil {
 			continue
 		}
 		if !reflect.DeepEqual(v, v1) {
@@ -85,9 +84,9 @@ type Marshaller struct {
 }
 
 func (m *Marshaller) MarshalJSON() ([]byte, error) {
-	return jsoniter.ConfigCompatibleWithStandardLibrary.Marshal(m.v)
+	return ConfigCompatibleWithStandardLibrary.Marshal(m.v)
 }
 
 func (m *Marshaller) UnmarshalJSON(data []byte) error {
-	return jsoniter.ConfigCompatibleWithStandardLibrary.Unmarshal(data, &m.v)
+	return ConfigCompatibleWithStandardLibrary.Unmarshal(data, &m.v)
 }