diff --git a/common/bufio/reader.go b/common/bufio/reader.go
index c9e430f0c..182323a37 100644
--- a/common/bufio/reader.go
+++ b/common/bufio/reader.go
@@ -25,8 +25,10 @@ func NewReader(rawReader io.Reader) *BufferedReader {
 
 // Release implements Releasable.Release().
 func (v *BufferedReader) Release() {
-	v.buffer.Release()
-	v.buffer = nil
+	if v.buffer != nil {
+		v.buffer.Release()
+		v.buffer = nil
+	}
 
 	common.Release(v.reader)
 }
diff --git a/common/crypto/io.go b/common/crypto/io.go
index 98ed242bf..1f7bc7420 100644
--- a/common/crypto/io.go
+++ b/common/crypto/io.go
@@ -31,8 +31,8 @@ func (v *CryptionReader) Read(data []byte) (int, error) {
 }
 
 func (v *CryptionReader) Release() {
-	v.reader = nil
-	v.stream = nil
+	common.Release(v.reader)
+	common.Release(v.stream)
 }
 
 type CryptionWriter struct {
@@ -56,6 +56,6 @@ func (v *CryptionWriter) Write(data []byte) (int, error) {
 }
 
 func (v *CryptionWriter) Release() {
-	v.writer = nil
-	v.stream = nil
+	common.Release(v.writer)
+	common.Release(v.stream)
 }
diff --git a/common/log/internal/log_entry.go b/common/log/internal/log_entry.go
index c9db04088..6f46bb6c2 100644
--- a/common/log/internal/log_entry.go
+++ b/common/log/internal/log_entry.go
@@ -19,10 +19,9 @@ type ErrorLog struct {
 }
 
 func (v *ErrorLog) Release() {
-	for index := range v.Values {
-		v.Values[index] = nil
+	for _, val := range v.Values {
+		common.Release(val)
 	}
-	v.Values = nil
 }
 
 func (v *ErrorLog) String() string {
@@ -37,9 +36,9 @@ type AccessLog struct {
 }
 
 func (v *AccessLog) Release() {
-	v.From = nil
-	v.To = nil
-	v.Reason = nil
+	common.Release(v.From)
+	common.Release(v.To)
+	common.Release(v.Reason)
 }
 
 func (v *AccessLog) String() string {
diff --git a/common/net/timed_io.go b/common/net/timed_io.go
index a56127e17..1ceca42e0 100644
--- a/common/net/timed_io.go
+++ b/common/net/timed_io.go
@@ -4,6 +4,8 @@ import (
 	"io"
 	"net"
 	"time"
+
+	"v2ray.com/core/common"
 )
 
 var (
@@ -51,8 +53,8 @@ func (reader *TimeOutReader) SetTimeOut(value uint32) {
 }
 
 func (reader *TimeOutReader) Release() {
-	reader.connection = nil
-	reader.worker = nil
+	common.Release(reader.connection)
+	common.Release(reader.worker)
 }
 
 type timedReaderWorker struct {
diff --git a/proxy/shadowsocks/ota.go b/proxy/shadowsocks/ota.go
index 6794cf218..26c202af3 100644
--- a/proxy/shadowsocks/ota.go
+++ b/proxy/shadowsocks/ota.go
@@ -6,6 +6,7 @@ import (
 	"crypto/sha1"
 	"io"
 
+	"v2ray.com/core/common"
 	"v2ray.com/core/common/buf"
 	"v2ray.com/core/common/errors"
 	"v2ray.com/core/common/serial"
@@ -70,8 +71,8 @@ func NewChunkReader(reader io.Reader, auth *Authenticator) *ChunkReader {
 }
 
 func (v *ChunkReader) Release() {
-	v.reader = nil
-	v.auth = nil
+	common.Release(v.reader)
+	common.Release(v.auth)
 }
 
 func (v *ChunkReader) Read() (*buf.Buffer, error) {
@@ -124,8 +125,8 @@ func NewChunkWriter(writer io.Writer, auth *Authenticator) *ChunkWriter {
 }
 
 func (v *ChunkWriter) Release() {
-	v.writer = nil
-	v.auth = nil
+	common.Release(v.writer)
+	common.Release(v.auth)
 }
 
 func (v *ChunkWriter) Write(payload *buf.Buffer) error {
diff --git a/proxy/vmess/vmess.go b/proxy/vmess/vmess.go
index cfeaaa4f4..68832d83a 100644
--- a/proxy/vmess/vmess.go
+++ b/proxy/vmess/vmess.go
@@ -69,11 +69,6 @@ func (v *TimedUserValidator) Release() {
 	}
 
 	v.running = false
-	v.validUsers = nil
-	v.userHash = nil
-	v.ids = nil
-	v.hasher = nil
-	v.cancel = nil
 }
 
 func (v *TimedUserValidator) generateNewHashes(nowSec protocol.Timestamp, idx int, entry *idEntry) {
@@ -89,10 +84,8 @@ func (v *TimedUserValidator) generateNewHashes(nowSec protocol.Timestamp, idx in
 		idHash.Sum(hashValueRemoval[:0])
 		idHash.Reset()
 
-		v.Lock()
 		v.userHash[hashValue] = &indexTimePair{idx, entry.lastSec}
 		delete(v.userHash, hashValueRemoval)
-		v.Unlock()
 
 		entry.lastSec++
 		entry.lastSecRemoval++
@@ -107,9 +100,11 @@ func (v *TimedUserValidator) updateUserHash(interval time.Duration) {
 		select {
 		case now := <-time.After(interval):
 			nowSec := protocol.Timestamp(now.Unix() + cacheDurationSec)
+			v.Lock()
 			for _, entry := range v.ids {
 				v.generateNewHashes(nowSec, entry.userIdx, entry)
 			}
+			v.Unlock()
 		case <-v.cancel.WaitForCancel():
 			return
 		}
@@ -117,6 +112,9 @@ func (v *TimedUserValidator) updateUserHash(interval time.Duration) {
 }
 
 func (v *TimedUserValidator) Add(user *protocol.User) error {
+	v.Lock()
+	defer v.Unlock()
+
 	idx := len(v.validUsers)
 	v.validUsers = append(v.validUsers, user)
 	rawAccount, err := user.GetTypedAccount()