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fix: protect cidrMap with lock #98

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1ab9a26
fix: protect cidrMap with lock
iamjaeholee Apr 1, 2026
e161a13
test: protect cidrMap access with lock in tests
iamjaeholee Apr 3, 2026
91c6f7b
refactor: pass cidrMap as parameter to satisfy protectedby linter
iamjaeholee Apr 3, 2026
1639208
address review: remove unnecessary comment and add lock requirement docs
iamjaeholee Apr 3, 2026
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78 changes: 42 additions & 36 deletions pkg/controller/ipam/multi_cidr_range_allocator.go
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Original file line number Diff line number Diff line change
Expand Up @@ -143,7 +143,7 @@ type multiCIDRRangeAllocator struct {

// lock guards cidrMap to avoid races in CIDR allocation.
lock *sync.Mutex
// cidrMap maps ClusterCIDR labels to internal ClusterCIDR objects.
// cidrMap maps ClusterCIDR labels to internal ClusterCIDR objects. Protected by lock.
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@stmcginnis stmcginnis Apr 3, 2026

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I don't think this comment is necessary.

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@iamjaeholee iamjaeholee Apr 3, 2026

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okay. i will delete it.

cidrMap map[string][]*cidrset.ClusterCIDR
}

Expand Down Expand Up @@ -199,7 +199,9 @@ func NewMultiCIDRRangeAllocator(

// testCIDRMap is only set for testing purposes.
if len(testCIDRMap) > 0 {
ra.lock.Lock()
ra.cidrMap = testCIDRMap
ra.lock.Unlock()
logger.Info("TestCIDRMap should only be set for testing purposes, if this is seen in production logs, it might be a misconfiguration or a bug")
}

Expand Down Expand Up @@ -256,26 +258,29 @@ func NewMultiCIDRRangeAllocator(
logger.Info("failed to add event handler to clusterCIDRInformer", "err", err)
}

ra.lock.Lock()
if allocatorParams.ServiceCIDR != nil {
ra.filterOutServiceRange(logger, allocatorParams.ServiceCIDR)
ra.filterOutServiceRange(logger, allocatorParams.ServiceCIDR, ra.cidrMap)
} else {
logger.Info("No Service CIDR provided. Skipping filtering out service addresses")
}

if allocatorParams.SecondaryServiceCIDR != nil {
ra.filterOutServiceRange(logger, allocatorParams.SecondaryServiceCIDR)
ra.filterOutServiceRange(logger, allocatorParams.SecondaryServiceCIDR, ra.cidrMap)
} else {
logger.Info("No Secondary Service CIDR provided. Skipping filtering out secondary service addresses")
}
ra.lock.Unlock()

if nodeList != nil {
ra.lock.Lock()
for _, node := range nodeList.Items {
if len(node.Spec.PodCIDRs) == 0 {
logger.V(4).Info("Node has no CIDR, ignoring", "node", klog.KObj(&node))
continue
}
logger.Info("Node has CIDR, occupying it in CIDR map", "node", klog.KObj(&node), "podCIDRs", node.Spec.PodCIDRs)
if err := ra.occupyCIDRs(logger, &node); err != nil {
if err := ra.occupyCIDRs(logger, &node, ra.cidrMap); err != nil {
// This will happen if:
// 1. We find garbage in the podCIDRs field. Retrying is useless.
// 2. CIDR out of range: This means ClusterCIDR is not yet created
Expand All @@ -284,6 +289,7 @@ func NewMultiCIDRRangeAllocator(
logger.Info("Node CIDR has no associated ClusterCIDR, skipping", "node", klog.KObj(&node), "error", err)
}
}
ra.lock.Unlock()
}

_, err = nodeInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{
Expand Down Expand Up @@ -510,11 +516,11 @@ func (r *multiCIDRRangeAllocator) syncClusterCIDR(ctx context.Context, key strin
}

// occupyCIDRs marks node.PodCIDRs[...] as used in allocator's tracked cidrSet.
func (r *multiCIDRRangeAllocator) occupyCIDRs(logger klog.Logger, node *corev1.Node) error {
func (r *multiCIDRRangeAllocator) occupyCIDRs(logger klog.Logger, node *corev1.Node, cidrMap map[string][]*cidrset.ClusterCIDR) error {
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@stmcginnis stmcginnis Apr 3, 2026

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A comment on these functions would be more useful, to point out that access to cidrMap should be protected by a lock before passing in for this and the similar functions below.

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@iamjaeholee iamjaeholee Apr 3, 2026

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I think so too. i will make a comment on the functions

if len(node.Spec.PodCIDRs) == 0 {
return nil
}
clusterCIDRList, err := r.orderedMatchingClusterCIDRs(node, true)
clusterCIDRList, err := r.orderedMatchingClusterCIDRs(node, true, cidrMap)
if err != nil {
return err
}
Expand Down Expand Up @@ -617,10 +623,10 @@ func (r *multiCIDRRangeAllocator) AllocateOrOccupyCIDR(logger klog.Logger, node
}

if len(node.Spec.PodCIDRs) > 0 {
return r.occupyCIDRs(logger, node)
return r.occupyCIDRs(logger, node, r.cidrMap)
}

cidrs, clusterCIDR, err := r.prioritizedCIDRs(logger, node)
cidrs, clusterCIDR, err := r.prioritizedCIDRs(logger, node, r.cidrMap)
if err != nil {
controllerutil.RecordNodeStatusChange(logger, r.recorder, node, "CIDRNotAvailable")
return fmt.Errorf("failed to get cidrs for node %s: %w", node.Name, err)
Expand Down Expand Up @@ -652,7 +658,7 @@ func (r *multiCIDRRangeAllocator) ReleaseCIDR(logger klog.Logger, node *corev1.N
return nil
}

clusterCIDR, err := r.allocatedClusterCIDR(node)
clusterCIDR, err := r.allocatedClusterCIDR(node, r.cidrMap)
if err != nil {
return err
}
Expand All @@ -677,13 +683,13 @@ func (r *multiCIDRRangeAllocator) ReleaseCIDR(logger klog.Logger, node *corev1.N

// Marks all CIDRs with subNetMaskSize that belongs to serviceCIDR as used across all cidrs
// so that they won't be assignable.
func (r *multiCIDRRangeAllocator) filterOutServiceRange(logger klog.Logger, serviceCIDR *net.IPNet) {
func (r *multiCIDRRangeAllocator) filterOutServiceRange(logger klog.Logger, serviceCIDR *net.IPNet, cidrMap map[string][]*cidrset.ClusterCIDR) {
// Checks if service CIDR has a nonempty intersection with cluster
// CIDR. It is the case if either clusterCIDR contains serviceCIDR with
// clusterCIDR's Mask applied (this means that clusterCIDR contains
// serviceCIDR) or vice versa (which means that serviceCIDR contains
// clusterCIDR).
for _, clusterCIDRList := range r.cidrMap {
for _, clusterCIDRList := range cidrMap {
for _, clusterCIDR := range clusterCIDRList {
if err := r.occupyServiceCIDR(clusterCIDR, serviceCIDR); err != nil {
logger.Error(err, "Unable to occupy service CIDR")
Expand Down Expand Up @@ -799,17 +805,17 @@ func defaultNodeSelector() *corev1.NodeSelector {
// Returns 1 CIDR if single stack.
// Returns 2 CIDRs , 1 from each ip family if dual stack.
func (r *multiCIDRRangeAllocator) prioritizedCIDRs(
logger klog.Logger, node *corev1.Node,
logger klog.Logger, node *corev1.Node, cidrMap map[string][]*cidrset.ClusterCIDR,
) ([]*net.IPNet, *cidrset.ClusterCIDR, error) {
clusterCIDRList, err := r.orderedMatchingClusterCIDRs(node, true)
clusterCIDRList, err := r.orderedMatchingClusterCIDRs(node, true, cidrMap)
if err != nil {
return nil, nil, fmt.Errorf("unable to get a clusterCIDR for node %s: %w", node.Name, err)
}

for _, clusterCIDR := range clusterCIDRList {
cidrs := make([]*net.IPNet, 0)
if clusterCIDR.IPv4CIDRSet != nil {
cidr, err := r.allocateCIDR(logger, clusterCIDR, clusterCIDR.IPv4CIDRSet)
cidr, err := r.allocateCIDR(logger, clusterCIDR, clusterCIDR.IPv4CIDRSet, cidrMap)
if err != nil {
logger.V(3).Info("Unable to allocate IPv4 CIDR, trying next range", "err", err)
continue
Expand All @@ -818,7 +824,7 @@ func (r *multiCIDRRangeAllocator) prioritizedCIDRs(
}

if clusterCIDR.IPv6CIDRSet != nil {
cidr, err := r.allocateCIDR(logger, clusterCIDR, clusterCIDR.IPv6CIDRSet)
cidr, err := r.allocateCIDR(logger, clusterCIDR, clusterCIDR.IPv6CIDRSet, cidrMap)
if err != nil {
logger.V(3).Info("Unable to allocate IPv6 CIDR, trying next range", "err", err)
continue
Expand All @@ -832,7 +838,7 @@ func (r *multiCIDRRangeAllocator) prioritizedCIDRs(
}

func (r *multiCIDRRangeAllocator) allocateCIDR(
logger klog.Logger, clusterCIDR *cidrset.ClusterCIDR, cidrSet *cidrset.MultiCIDRSet,
logger klog.Logger, clusterCIDR *cidrset.ClusterCIDR, cidrSet *cidrset.MultiCIDRSet, cidrMap map[string][]*cidrset.ClusterCIDR,
) (*net.IPNet, error) {
for evaluated := 0; evaluated < cidrSet.MaxCIDRs; evaluated++ {
candidate, lastEvaluated, err := cidrSet.NextCandidate()
Expand All @@ -842,12 +848,12 @@ func (r *multiCIDRRangeAllocator) allocateCIDR(

evaluated += lastEvaluated

if r.cidrInAllocatedList(logger, candidate) {
if r.cidrInAllocatedList(logger, candidate, cidrMap) {
continue
}

// Deep Check.
if r.cidrOverlapWithAllocatedList(logger, candidate) {
if r.cidrOverlapWithAllocatedList(logger, candidate, cidrMap) {
continue
}

Expand All @@ -864,8 +870,8 @@ func (r *multiCIDRRangeAllocator) allocateCIDR(
}
}

func (r *multiCIDRRangeAllocator) cidrInAllocatedList(logger klog.Logger, cidr *net.IPNet) bool {
for _, clusterCIDRList := range r.cidrMap {
func (r *multiCIDRRangeAllocator) cidrInAllocatedList(logger klog.Logger, cidr *net.IPNet, cidrMap map[string][]*cidrset.ClusterCIDR) bool {
for _, clusterCIDRList := range cidrMap {
for _, clusterCIDR := range clusterCIDRList {
cidrSet, err := r.associatedCIDRSet(clusterCIDR, cidr)
if err != nil {
Expand All @@ -882,8 +888,8 @@ func (r *multiCIDRRangeAllocator) cidrInAllocatedList(logger klog.Logger, cidr *
return false
}

func (r *multiCIDRRangeAllocator) cidrOverlapWithAllocatedList(logger klog.Logger, cidr *net.IPNet) bool {
for _, clusterCIDRList := range r.cidrMap {
func (r *multiCIDRRangeAllocator) cidrOverlapWithAllocatedList(logger klog.Logger, cidr *net.IPNet, cidrMap map[string][]*cidrset.ClusterCIDR) bool {
for _, clusterCIDRList := range cidrMap {
for _, clusterCIDR := range clusterCIDRList {
cidrSet, err := r.associatedCIDRSet(clusterCIDR, cidr)
if err != nil {
Expand All @@ -901,8 +907,8 @@ func (r *multiCIDRRangeAllocator) cidrOverlapWithAllocatedList(logger klog.Logge
}

// allocatedClusterCIDR returns the ClusterCIDR from which the node CIDRs were allocated.
func (r *multiCIDRRangeAllocator) allocatedClusterCIDR(node *corev1.Node) (*cidrset.ClusterCIDR, error) {
clusterCIDRList, err := r.orderedMatchingClusterCIDRs(node, false)
func (r *multiCIDRRangeAllocator) allocatedClusterCIDR(node *corev1.Node, cidrMap map[string][]*cidrset.ClusterCIDR) (*cidrset.ClusterCIDR, error) {
clusterCIDRList, err := r.orderedMatchingClusterCIDRs(node, false, cidrMap)
if err != nil {
return nil, fmt.Errorf("unable to get a clusterCIDR for node %s: %w", node.Name, err)
}
Expand All @@ -926,11 +932,11 @@ func (r *multiCIDRRangeAllocator) allocatedClusterCIDR(node *corev1.Node) (*cidr
// orderedMatchingClusterCIDRs takes `occupy` as an argument, it determines whether the function
// is called during an occupy or a release operation. For a release operation, a ClusterCIDR must
// be added to the matching ClusterCIDRs list, irrespective of whether the ClusterCIDR is terminating.
func (r *multiCIDRRangeAllocator) orderedMatchingClusterCIDRs(node *corev1.Node, occupy bool) ([]*cidrset.ClusterCIDR, error) {
func (r *multiCIDRRangeAllocator) orderedMatchingClusterCIDRs(node *corev1.Node, occupy bool, cidrMap map[string][]*cidrset.ClusterCIDR) ([]*cidrset.ClusterCIDR, error) {
matchingCIDRs := make([]*cidrset.ClusterCIDR, 0)
pq := make(PriorityQueue, 0)

for label, clusterCIDRList := range r.cidrMap {
for label, clusterCIDRList := range cidrMap {
labelsMatch, matchCnt, err := r.matchCIDRLabels(node, label)
if err != nil {
return nil, err
Expand Down Expand Up @@ -968,7 +974,7 @@ func (r *multiCIDRRangeAllocator) orderedMatchingClusterCIDRs(node *corev1.Node,
if err != nil {
return nil, err
}
if clusterCIDRList, ok := r.cidrMap[defaultSelector.String()]; ok {
if clusterCIDRList, ok := cidrMap[defaultSelector.String()]; ok {
matchingCIDRs = append(matchingCIDRs, clusterCIDRList...)
}
return matchingCIDRs, nil
Expand Down Expand Up @@ -1081,7 +1087,7 @@ func (r *multiCIDRRangeAllocator) reconcileCreate(ctx context.Context, clusterCI

logger := klog.FromContext(ctx)
logger.V(3).Info("Reconciling ClusterCIDR", "clusterCIDR", clusterCIDR.Name)
if err := r.createClusterCIDR(ctx, clusterCIDR, false); err != nil {
if err := r.createClusterCIDR(ctx, clusterCIDR, false, r.cidrMap); err != nil {
logger.Error(err, "failed to reconcile ClusterCIDR", "clusterCIDR", clusterCIDR.Name)
return err
}
Expand All @@ -1104,7 +1110,7 @@ func (r *multiCIDRRangeAllocator) reconcileBootstrap(ctx context.Context, cluste
}

logger.V(2).Info("Creating ClusterCIDR during bootstrap", "clusterCIDR", clusterCIDR.Name)
if err := r.createClusterCIDR(ctx, clusterCIDR, terminating); err != nil {
if err := r.createClusterCIDR(ctx, clusterCIDR, terminating, r.cidrMap); err != nil {
logger.Error(err, "Unable to create ClusterCIDR", "clusterCIDR", clusterCIDR.Name)
return err
}
Expand All @@ -1113,7 +1119,7 @@ func (r *multiCIDRRangeAllocator) reconcileBootstrap(ctx context.Context, cluste
}

// createClusterCIDR creates and maps the cidrSets in the cidrMap.
func (r *multiCIDRRangeAllocator) createClusterCIDR(ctx context.Context, clusterCIDR *v1.ClusterCIDR, terminating bool) error {
func (r *multiCIDRRangeAllocator) createClusterCIDR(ctx context.Context, clusterCIDR *v1.ClusterCIDR, terminating bool, cidrMap map[string][]*cidrset.ClusterCIDR) error {
nodeSelector, err := r.nodeSelectorKey(clusterCIDR)
if err != nil {
return fmt.Errorf("unable to get labelSelector key: %w", err)
Expand All @@ -1128,7 +1134,7 @@ func (r *multiCIDRRangeAllocator) createClusterCIDR(ctx context.Context, cluster
return errors.New("invalid ClusterCIDR: must provide IPv4 and/or IPv6 config")
}

if err := r.mapClusterCIDRSet(r.cidrMap, nodeSelector, clusterCIDRSet); err != nil {
if err := r.mapClusterCIDRSet(cidrMap, nodeSelector, clusterCIDRSet); err != nil {
return fmt.Errorf("unable to map clusterCIDRSet: %w", err)
}

Expand Down Expand Up @@ -1222,7 +1228,7 @@ func (r *multiCIDRRangeAllocator) reconcileDelete(ctx context.Context, clusterCI
logger := klog.FromContext(ctx)
if slices.Contains(clusterCIDR.GetFinalizers(), clusterCIDRFinalizer) {
logger.V(2).Info("Releasing ClusterCIDR", "clusterCIDR", clusterCIDR.Name)
if err := r.deleteClusterCIDR(logger, clusterCIDR); err != nil {
if err := r.deleteClusterCIDR(logger, clusterCIDR, r.cidrMap); err != nil {
logger.V(2).Info("Error while deleting ClusterCIDR", "err", err)
return err
}
Expand All @@ -1242,13 +1248,13 @@ func (r *multiCIDRRangeAllocator) reconcileDelete(ctx context.Context, clusterCI
}

// deleteClusterCIDR Deletes and unmaps the ClusterCIDRs from the cidrMap.
func (r *multiCIDRRangeAllocator) deleteClusterCIDR(logger klog.Logger, clusterCIDR *v1.ClusterCIDR) error {
func (r *multiCIDRRangeAllocator) deleteClusterCIDR(logger klog.Logger, clusterCIDR *v1.ClusterCIDR, cidrMap map[string][]*cidrset.ClusterCIDR) error {
labelSelector, err := r.nodeSelectorKey(clusterCIDR)
if err != nil {
return fmt.Errorf("unable to delete cidr: %w", err)
}

clusterCIDRSetList, ok := r.cidrMap[labelSelector]
clusterCIDRSetList, ok := cidrMap[labelSelector]
if !ok {
logger.Info("Label not found in CIDRMap, proceeding with delete", "labelSelector", labelSelector)
return nil
Expand All @@ -1270,12 +1276,12 @@ func (r *multiCIDRRangeAllocator) deleteClusterCIDR(logger klog.Logger, clusterC
// Remove the label from the map if this was the only clusterCIDR associated
// with it.
if len(clusterCIDRSetList) == 1 {
delete(r.cidrMap, labelSelector)
delete(cidrMap, labelSelector)
return nil
}

clusterCIDRSetList = append(clusterCIDRSetList[:i], clusterCIDRSetList[i+1:]...)
r.cidrMap[labelSelector] = clusterCIDRSetList
cidrMap[labelSelector] = clusterCIDRSetList
return nil
}
logger.V(2).Info("clusterCIDR not found, proceeding with delete", "clusterCIDR", clusterCIDR.Name, "label", labelSelector)
Expand Down
22 changes: 20 additions & 2 deletions pkg/controller/ipam/multi_cidr_range_allocator_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1049,7 +1049,9 @@ func TestMultiCIDRAllocateOrOccupyCIDRSuccess(t *testing.T) {
t.Fatalf("%v: unexpected error when parsing CIDR %v: %v", tc.description, allocated, err)
}

rangeAllocator.lock.Lock()
clusterCIDRList, err := getClusterCIDRList("node0", rangeAllocator.cidrMap)
rangeAllocator.lock.Unlock()
if err != nil {
t.Fatalf("%v: unexpected error when getting associated clusterCIDR for node %v %v", tc.description, "node0", err)
}
Expand Down Expand Up @@ -1349,7 +1351,9 @@ func TestMultiCIDRAllocateOrOccupyCIDRFailure(t *testing.T) {
t.Fatalf("%v: unexpected error when parsing CIDR %v: %v", tc.description, allocated, err)
}

rangeAllocator.lock.Lock()
clusterCIDRList, err := getClusterCIDRList("node0", rangeAllocator.cidrMap)
rangeAllocator.lock.Unlock()
if err != nil {
t.Fatalf("%v: unexpected error when getting associated clusterCIDR for node %v %v", tc.description, "node0", err)
}
Expand Down Expand Up @@ -1538,7 +1542,9 @@ func TestMultiCIDRReleaseCIDRSuccess(t *testing.T) {
t.Fatalf("%v: unexpected error when parsing CIDR %v: %v", tc.description, allocated, err)
}

rangeAllocator.lock.Lock()
clusterCIDRList, err := getClusterCIDRList("node0", rangeAllocator.cidrMap)
rangeAllocator.lock.Unlock()
if err != nil {
t.Fatalf("%v: unexpected error when getting associated clusterCIDR for node %v %v", tc.description, "node0", err)
}
Expand Down Expand Up @@ -1826,8 +1832,10 @@ func TestSyncClusterCIDRDeleteWithNodesAssociated(t *testing.T) {

// Mock the IPAM controller behavior associating node with ClusterCIDR.
nodeSelectorKey, _ := cccController.nodeSelectorKey(testCCC)
cccController.lock.Lock()
clusterCIDRs := cccController.cidrMap[nodeSelectorKey]
clusterCIDRs[0].AssociatedNodes["test-node"] = true
cccController.lock.Unlock()

createdCCC, err := client.NetworkingV1().ClusterCIDRs().Get(context.TODO(), testCCC.Name, metav1.GetOptions{})
assert.Nil(t, err, "Expected no error getting clustercidr object")
Expand Down Expand Up @@ -1866,8 +1874,18 @@ func TestMultiCIDRSetDataRace(t *testing.T) {
wg.Add(4)
go func() { defer wg.Done(); cidrSet.Occupy(lookupCIDR) }()
go func() { defer wg.Done(); cidrSet.Release(lookupCIDR) }()
go func() { defer wg.Done(); ra.cidrInAllocatedList(logger, lookupCIDR) }()
go func() { defer wg.Done(); ra.cidrOverlapWithAllocatedList(logger, lookupCIDR) }()
go func() {
defer wg.Done()
ra.lock.Lock()
ra.cidrInAllocatedList(logger, lookupCIDR, ra.cidrMap)
ra.lock.Unlock()
}()
go func() {
defer wg.Done()
ra.lock.Lock()
ra.cidrOverlapWithAllocatedList(logger, lookupCIDR, ra.cidrMap)
ra.lock.Unlock()
}()
wg.Wait()
}

Expand Down
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