Merge pull request #32244 from tksm/fix-cache-race

Automatic merge from submit-queue

LRUExpireCache#Get requires write lock

**What this PR does / why we need it**:

[LRUExpireCache#Get](dbfad789e3/pkg/util/cache/lruexpirecache.go (L48)) requires write lock since [groupcache/lru#Get](a6b377e340/lru/lru.go (L74)) needs to manipulate its list to track recently used item. Currently it uses read lock so it may introduce race condition.

- [test code which introduces race condition with current LRUExpireCache#Get](https://gist.github.com/tksm/17c7a610ed0574c165e6f6edeca351b7#file-lru_race_test-go)

**Which issue this PR fixes** #31081

pkg/util/cache/lruexpirecache.go

@@ -25,7 +25,7 @@ import (
 
 type LRUExpireCache struct {
 	cache *lru.Cache
-	lock  sync.RWMutex
+	lock  sync.Mutex
 }
 
 func NewLRUExpireCache(maxSize int) *LRUExpireCache {
@@ -46,8 +46,8 @@ func (c *LRUExpireCache) Add(key lru.Key, value interface{}, ttl time.Duration)
 }
 
 func (c *LRUExpireCache) Get(key lru.Key) (interface{}, bool) {
-	c.lock.RLock()
-	defer c.lock.RUnlock()
+	c.lock.Lock()
+	defer c.lock.Unlock()
 	e, ok := c.cache.Get(key)
 	if !ok {
 		return nil, false