diff --git a/util/execdetails/execdetails.go b/util/execdetails/execdetails.go
index a5a603b447947..f54614a0b434c 100644
--- a/util/execdetails/execdetails.go
+++ b/util/execdetails/execdetails.go
@@ -911,6 +911,7 @@ func NewRuntimeStatsColl(reuse *RuntimeStatsColl) *RuntimeStatsColl {
 // RegisterStats register execStat for a executor.
 func (e *RuntimeStatsColl) RegisterStats(planID int, info RuntimeStats) {
 	e.mu.Lock()
+	defer e.mu.Unlock()
 	stats, ok := e.rootStats[planID]
 	if !ok {
 		stats = NewRootRuntimeStats()
@@ -928,7 +929,6 @@ func (e *RuntimeStatsColl) RegisterStats(planID int, info RuntimeStats) {
 	if !found {
 		stats.groupRss = append(stats.groupRss, info.Clone())
 	}
-	e.mu.Unlock()
 }
 
 // GetBasicRuntimeStats gets basicRuntimeStats for a executor.