From c5cc58d0de6663627f4826ad808d82ea38b28635 Mon Sep 17 00:00:00 2001
From: googs1025 <googs1025@gmail.com>
Date: Sun, 1 Jun 2025 13:44:23 +0800
Subject: [PATCH] fix: data race for patchResource func

Signed-off-by: googs1025 <googs1025@gmail.com>

Kubernetes-commit: 2fd93c0898856ba764adef8efcaace9ff0c49f23
---
 pkg/endpoints/handlers/patch.go     |  8 +++++
 pkg/endpoints/handlers/rest_test.go | 48 +++++++++++++++++++++++++++--
 2 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/pkg/endpoints/handlers/patch.go b/pkg/endpoints/handlers/patch.go
index 0dc9ffb33..060c7cc30 100644
--- a/pkg/endpoints/handlers/patch.go
+++ b/pkg/endpoints/handlers/patch.go
@@ -726,6 +726,14 @@ func (p *patcher) patchResource(ctx context.Context, scope *RequestScope) (runti
 		}
 		return result, err
 	})
+
+	// In case of a timeout error, the goroutine handling the request is still running.
+	// https://github.com/kubernetes/kubernetes/blob/d2c12afa4593e50a187075157d38748292b02733/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/finisher/finisher.go#L127-L146
+	// We cannot reliably read the variable (data race!) and have to assume that
+	// the object was not created.
+	if errors.IsTimeout(err) {
+		return result, false, err
+	}
 	return result, wasCreated, err
 }
 
diff --git a/pkg/endpoints/handlers/rest_test.go b/pkg/endpoints/handlers/rest_test.go
index 7f4b1f3e6..1429977fc 100644
--- a/pkg/endpoints/handlers/rest_test.go
+++ b/pkg/endpoints/handlers/rest_test.go
@@ -323,6 +323,25 @@ func TestPatchCustomResource(t *testing.T) {
 	}
 }
 
+type testTimeoutPatcher struct {
+	t *testing.T
+}
+
+func (p *testTimeoutPatcher) New() runtime.Object {
+	return &example.Pod{}
+}
+
+func (p *testTimeoutPatcher) Update(ctx context.Context, _ string, _ rest.UpdatedObjectInfo, _ rest.ValidateObjectFunc, _ rest.ValidateObjectUpdateFunc, _ bool, _ *metav1.UpdateOptions) (runtime.Object, bool, error) {
+	// Block until the context is canceled to simulate a timeout scenario.
+	<-ctx.Done()
+	return nil, false, ctx.Err()
+}
+
+func (p *testTimeoutPatcher) Get(ctx context.Context, name string, options *metav1.GetOptions) (runtime.Object, error) {
+	p.t.Fatal("unexpected call to testPatcher.Get")
+	return nil, errors.New("unexpected call to testPatcher.Get")
+}
+
 type testPatcher struct {
 	t *testing.T
 
@@ -432,6 +451,9 @@ type patchTestCase struct {
 	expectedError string
 	// if set, indicates the number of times patching was expected to be attempted
 	expectedTries int
+
+	// isTimeout for this test case
+	isTimeout bool
 }
 
 func (tc *patchTestCase) Run(t *testing.T) {
@@ -564,8 +586,16 @@ func (tc *patchTestCase) Run(t *testing.T) {
 				FieldManager: "test-manager",
 			},
 		}
-
-		ctx, cancel := context.WithTimeout(ctx, time.Second)
+		var timeout time.Duration
+		if tc.isTimeout {
+			// Simulate timeout by using a zero-duration timeout and the timeout patcher
+			// replace testPatcher with the timeout simulator
+			timeout = 0
+			p.restPatcher = &testTimeoutPatcher{t: t}
+		} else {
+			timeout = time.Second
+		}
+		ctx, cancel := context.WithTimeout(ctx, timeout)
 		resultObj, _, err := p.patchResource(ctx, &RequestScope{
 			FieldManager: fieldmanager,
 		})
@@ -679,6 +709,20 @@ func TestPatchResourceNumberConversion(t *testing.T) {
 	tc.Run(t)
 }
 
+func TestPatchResourceTimeout(t *testing.T) {
+	tc := &patchTestCase{
+		name:          "TestPatchResourceTimeout",
+		startingPod:   &example.Pod{},
+		changedPod:    &example.Pod{},
+		updatePod:     &example.Pod{},
+		expectedPod:   nil,
+		isTimeout:     true,
+		expectedError: "Timeout: request did not complete within requested timeout - context deadline exceeded",
+	}
+
+	tc.Run(t)
+}
+
 func TestPatchResourceWithVersionConflict(t *testing.T) {
 	namespace := "bar"
 	name := "foo"