From a8f751c0b51ed4bedfa7abd151492bec4e3832ea Mon Sep 17 00:00:00 2001
From: "weizhou.lan@daocloud.io" <weizhou.lan@daocloud.io>
Date: Thu, 14 May 2026 15:30:34 +0800
Subject: [PATCH] Fix kubelet startup failure when restoring legacy V3 CPU
 manager checkpoints

Signed-off-by: weizhou.lan@daocloud.io <weizhou.lan@daocloud.io>
---
 pkg/kubelet/cm/cpumanager/state/checkpoint.go | 19 ++++++++-
 .../cpumanager/state/state_checkpoint_test.go | 41 ++++++++++++++++++-
 2 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/pkg/kubelet/cm/cpumanager/state/checkpoint.go b/pkg/kubelet/cm/cpumanager/state/checkpoint.go
index eec993d9fae..8c7b6f99233 100644
--- a/pkg/kubelet/cm/cpumanager/state/checkpoint.go
+++ b/pkg/kubelet/cm/cpumanager/state/checkpoint.go
@@ -267,8 +267,25 @@ func (cp *CPUManagerCheckpointV3) VerifyChecksum() error {
 	ck := cp.Checksum
 	cp.Checksum = 0
 	err := ck.Verify(cp)
+	if err == nil {
+		cp.Checksum = ck
+		return nil
+	}
+
+	object := dump.ForHash(cp)
+	object = strings.Replace(object, "CPUManagerCheckpointV3", "CPUManagerCheckpoint", 1)
 	cp.Checksum = ck
-	return err
+
+	hash := fnv.New32a()
+	_, _ = fmt.Fprintf(hash, "%v", object)
+	actualCS := checksum.Checksum(hash.Sum32())
+	if cp.Checksum != actualCS {
+		return &errors.CorruptCheckpointError{
+			ActualCS:   uint64(actualCS),
+			ExpectedCS: uint64(cp.Checksum),
+		}
+	}
+	return nil
 }
 
 // VerifyChecksum verifies that current checksum of checkpoint is valid in v4 format
diff --git a/pkg/kubelet/cm/cpumanager/state/state_checkpoint_test.go b/pkg/kubelet/cm/cpumanager/state/state_checkpoint_test.go
index 6a45ded9eeb..ff62d6b6a24 100644
--- a/pkg/kubelet/cm/cpumanager/state/state_checkpoint_test.go
+++ b/pkg/kubelet/cm/cpumanager/state/state_checkpoint_test.go
@@ -322,7 +322,7 @@ func TestCheckpointStateRestore(t *testing.T) {
 						"cpuSet":"7-9"
 					}
 				},
-				"checksum": 2284712151
+				"checksum": 766259872
 			}`,
 			"static",
 			containermap.ContainerMap{},
@@ -354,7 +354,7 @@ func TestCheckpointStateRestore(t *testing.T) {
 						"cpuSet":"7-9"
 					}
 				},
-				"checksum": 2284712151
+				"checksum": 766259872
 			}`,
 			"static",
 			containermap.ContainerMap{},
@@ -775,6 +775,43 @@ func TestCPUManagerCheckpoint_MarshalCheckpoint_HashCompatibility(t *testing.T)
 	}
 }
 
+func TestCPUManagerCheckpointV3_VerifyChecksum_Compatibility(t *testing.T) {
+	testCases := []struct {
+		name     string
+		checksum checksum.Checksum
+	}{
+		{
+			name:     "accepts legacy v3 checksum",
+			checksum: 766259872,
+		},
+		{
+			name:     "accepts current v3 checksum",
+			checksum: 2284712151,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			cp := &CPUManagerCheckpointV3{
+				PolicyName:    "static",
+				DefaultCPUSet: "1-2",
+				Entries: map[string]map[string]string{
+					"pod1": {
+						"container1": "5-6",
+						"container2": "3-4",
+					},
+				},
+				PodEntries: PodCPUAssignments{
+					"pod2": {CPUSet: cpuset.New(7, 8, 9)},
+				},
+				Checksum: tc.checksum,
+			}
+
+			require.NoError(t, cp.VerifyChecksum())
+		})
+	}
+}
+
 func removeAll(dir string, t *testing.T) {
 	t.Helper()
 	if err := os.RemoveAll(dir); err != nil {