diff --git a/ddl/reorg.go b/ddl/reorg.go
index 3eaa8080f1f73..e0b60887104a4 100644
--- a/ddl/reorg.go
+++ b/ddl/reorg.go
@@ -277,10 +277,12 @@ func (w *worker) runReorgJob(rh *reorgHandler, reorgInfo *reorgInfo, tblInfo *mo
 func (w *worker) mergeWarningsIntoJob(job *model.Job) {
 	rc := w.getReorgCtx(job.ID)
 	rc.mu.Lock()
-	defer rc.mu.Unlock()
 	partWarnings := rc.mu.warnings
 	partWarningsCount := rc.mu.warningsCount
-	job.SetWarnings(mergeWarningsAndWarningsCount(partWarnings, job.ReorgMeta.Warnings, partWarningsCount, job.ReorgMeta.WarningsCount))
+	rc.mu.Unlock()
+	warnings, warningsCount := job.GetWarnings()
+	warnings, warningsCount = mergeWarningsAndWarningsCount(partWarnings, warnings, partWarningsCount, warningsCount)
+	job.SetWarnings(warnings, warningsCount)
 }
 
 func updateBackfillProgress(w *worker, reorgInfo *reorgInfo, tblInfo *model.TableInfo,
diff --git a/parser/model/ddl.go b/parser/model/ddl.go
index 7ca33341258c5..574e8d932193c 100644
--- a/parser/model/ddl.go
+++ b/parser/model/ddl.go
@@ -598,13 +598,18 @@ func (job *Job) GetRowCount() int64 {
 
 // SetWarnings sets the warnings of rows handled.
 func (job *Job) SetWarnings(warnings map[errors.ErrorID]*terror.Error, warningsCount map[errors.ErrorID]int64) {
+	job.Mu.Lock()
 	job.ReorgMeta.Warnings = warnings
 	job.ReorgMeta.WarningsCount = warningsCount
+	job.Mu.Unlock()
 }
 
 // GetWarnings gets the warnings of the rows handled.
 func (job *Job) GetWarnings() (map[errors.ErrorID]*terror.Error, map[errors.ErrorID]int64) {
-	return job.ReorgMeta.Warnings, job.ReorgMeta.WarningsCount
+	job.Mu.Lock()
+	w, wc := job.ReorgMeta.Warnings, job.ReorgMeta.WarningsCount
+	job.Mu.Unlock()
+	return w, wc
 }
 
 // Encode encodes job with json format.
@@ -672,7 +677,8 @@ func (job *Job) String() string {
 	ret := fmt.Sprintf("ID:%d, Type:%s, State:%s, SchemaState:%s, SchemaID:%d, TableID:%d, RowCount:%d, ArgLen:%d, start time: %v, Err:%v, ErrCount:%d, SnapshotVersion:%v",
 		job.ID, job.Type, job.State, job.SchemaState, job.SchemaID, job.TableID, rowCount, len(job.Args), TSConvert2Time(job.StartTS), job.Error, job.ErrorCount, job.SnapshotVer)
 	if job.ReorgMeta != nil {
-		ret += fmt.Sprintf(", UniqueWarnings:%d", len(job.ReorgMeta.Warnings))
+		warnings, _ := job.GetWarnings()
+		ret += fmt.Sprintf(", UniqueWarnings:%d", len(warnings))
 	}
 	if job.Type != ActionMultiSchemaChange && job.MultiSchemaInfo != nil {
 		ret += fmt.Sprintf(", Multi-Schema Change:true, Revertible:%v", job.MultiSchemaInfo.Revertible)