Prevent Int64 Overflow (#3605)

* Prevent Int64 Overflow

* Necessary changes

* Modify Counter count

* Review changes

* update unit test

* use big.Int

* Review changes

* changes in controller_test.go

pkg/apis/agones/v1/common.go

@@ -15,6 +15,8 @@
 package v1
 
 import (
+	"math"
+
 	apivalidation "k8s.io/apimachinery/pkg/api/validation"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	metav1validation "k8s.io/apimachinery/pkg/apis/meta/v1/validation"
@@ -183,3 +185,11 @@ type Priority struct {
 	// "Ascending" would be smaller Capacity is preferred.
 	Order string `json:"order"`
 }
+
+// SafeAdd prevents overflow by limiting the sum to math.MaxInt64.
+func SafeAdd(x, y int64) int64 {
+	if x > math.MaxInt64-y {
+		return math.MaxInt64
+	}
+	return x + y
+}

pkg/fleets/controller.go

@@ -730,10 +730,10 @@ func mergeCounters(c1, c2 map[string]agonesv1.AggregatedCounterStatus) map[strin
 	for key, val := range c2 {
 		// If the Counter exists in both maps, aggregate the values.
 		if counter, ok := c1[key]; ok {
-			counter.AllocatedCapacity += val.AllocatedCapacity
-			counter.AllocatedCount += val.AllocatedCount
-			counter.Capacity += val.Capacity
-			counter.Count += val.Count
+			counter.AllocatedCapacity = agonesv1.SafeAdd(counter.AllocatedCapacity, val.AllocatedCapacity)
+			counter.AllocatedCount = agonesv1.SafeAdd(counter.AllocatedCount, val.AllocatedCount)
+			counter.Capacity = agonesv1.SafeAdd(counter.Capacity, val.Capacity)
+			counter.Count = agonesv1.SafeAdd(counter.Count, val.Count)
 			c1[key] = counter
 		} else {
 			c1[key] = *val.DeepCopy()

pkg/fleets/controller_test.go

@@ -704,10 +704,10 @@ func TestControllerUpdateFleetCounterStatus(t *testing.T) {
 	gsSet1.ObjectMeta.Name = "gsSet1"
 	gsSet1.Status.Counters = map[string]agonesv1.AggregatedCounterStatus{
 		"fullCounter": {
-			AllocatedCount:    1000,
-			AllocatedCapacity: 1000,
-			Capacity:          1000,
-			Count:             1000,
+            AllocatedCount:    9223372036854775807,
+            AllocatedCapacity: 9223372036854775807,
+            Capacity:          9223372036854775807,
+            Count:             9223372036854775807,
 		},
 		"anotherCounter": {
 			AllocatedCount:    11,
@@ -752,10 +752,10 @@ func TestControllerUpdateFleetCounterStatus(t *testing.T) {
 			ua := action.(k8stesting.UpdateAction)
 			fleet := ua.GetObject().(*agonesv1.Fleet)
 
-			assert.Equal(t, int64(1100), fleet.Status.Counters["fullCounter"].AllocatedCount)
-			assert.Equal(t, int64(1100), fleet.Status.Counters["fullCounter"].AllocatedCapacity)
-			assert.Equal(t, int64(1100), fleet.Status.Counters["fullCounter"].Capacity)
-			assert.Equal(t, int64(1100), fleet.Status.Counters["fullCounter"].Count)
+            assert.Equal(t, int64(9223372036854775807), fleet.Status.Counters["fullCounter"].AllocatedCount)
+            assert.Equal(t, int64(9223372036854775807), fleet.Status.Counters["fullCounter"].AllocatedCapacity)
+            assert.Equal(t, int64(9223372036854775807), fleet.Status.Counters["fullCounter"].Capacity)
+            assert.Equal(t, int64(9223372036854775807), fleet.Status.Counters["fullCounter"].Count)
 
 			assert.Equal(t, int64(11), fleet.Status.Counters["anotherCounter"].AllocatedCount)
 			assert.Equal(t, int64(20), fleet.Status.Counters["anotherCounter"].AllocatedCapacity)

pkg/gameserversets/controller.go

@@ -679,12 +679,13 @@ func aggregateCounters(aggCounterStatus map[string]agonesv1.AggregatedCounterSta
 		// If the Counter exists in both maps, aggregate the values.
 		if counter, ok := aggCounterStatus[key]; ok {
 			// Aggregate for all game server statuses (expected IsBeingDeleted)
-			counter.Count += val.Count
-			counter.Capacity += val.Capacity
+			counter.Count = agonesv1.SafeAdd(counter.Count, val.Count)
+			counter.Capacity = agonesv1.SafeAdd(counter.Capacity, val.Capacity)
+
 			// Aggregate for Allocated game servers only
 			if gsState == agonesv1.GameServerStateAllocated {
-				counter.AllocatedCount += val.Count
-				counter.AllocatedCapacity += val.Capacity
+				counter.AllocatedCount = agonesv1.SafeAdd(counter.AllocatedCount, val.Count)
+				counter.AllocatedCapacity = agonesv1.SafeAdd(counter.AllocatedCapacity, val.Capacity)
 			}
 			aggCounterStatus[key] = counter
 		} else {

pkg/gameserversets/controller_test.go

@@ -356,20 +356,24 @@ func TestComputeStatus(t *testing.T) {
 		gs1.Status.Counters = map[string]agonesv1.CounterStatus{
 			"firstCounter":  {Count: 5, Capacity: 10},
 			"secondCounter": {Count: 100, Capacity: 1000},
+			"fullCounter":   {Count: 9223372036854775807, Capacity: 9223372036854775807},
 		}
 		gs2 := gsWithState(agonesv1.GameServerStateReserved)
 		gs2.Status.Counters = map[string]agonesv1.CounterStatus{
 			"firstCounter": {Count: 10, Capacity: 15},
+			"fullCounter":  {Count: 9223372036854775807, Capacity: 9223372036854775807},
 		}
 		gs3 := gsWithState(agonesv1.GameServerStateCreating)
 		gs3.Status.Counters = map[string]agonesv1.CounterStatus{
 			"firstCounter":  {Count: 20, Capacity: 30},
 			"secondCounter": {Count: 100, Capacity: 1000},
+			"fullCounter":   {Count: 9223372036854775807, Capacity: 9223372036854775807},
 		}
 		gs4 := gsWithState(agonesv1.GameServerStateReady)
 		gs4.Status.Counters = map[string]agonesv1.CounterStatus{
 			"firstCounter":  {Count: 15, Capacity: 30},
 			"secondCounter": {Count: 20, Capacity: 200},
+			"fullCounter":   {Count: 9223372036854775807, Capacity: 9223372036854775807},
 		}
 		list = append(list, gs1, gs2, gs3, gs4)
 
@@ -391,6 +395,12 @@ func TestComputeStatus(t *testing.T) {
 					Count:             220,
 					Capacity:          2200,
 				},
+				"fullCounter": {
+					AllocatedCount:    9223372036854775807,
+					AllocatedCapacity: 9223372036854775807,
+					Count:             9223372036854775807,
+					Capacity:          9223372036854775807,
+				},
 			},
 			Lists: map[string]agonesv1.AggregatedListStatus{},
 		}