diff --git a/common/buf/multi_buffer.go b/common/buf/multi_buffer.go
index 6f92717c..a93aa119 100644
--- a/common/buf/multi_buffer.go
+++ b/common/buf/multi_buffer.go
@@ -118,7 +118,7 @@ func (mb *MultiBuffer) ReadFrom(reader io.Reader) (int64, error) {
 
 // Read implements io.Reader.
 func (mb *MultiBuffer) Read(b []byte) (int, error) {
-	if mb.Len() == 0 {
+	if mb.IsEmpty() {
 		return 0, io.EOF
 	}
 	endIndex := len(*mb)
diff --git a/common/buf/reader.go b/common/buf/reader.go
index 5f3ac868..cd9d93a8 100644
--- a/common/buf/reader.go
+++ b/common/buf/reader.go
@@ -97,8 +97,9 @@ func (r *BufferedReader) ReadByte() (byte, error) {
 
 // Read implements io.Reader. It reads from internal buffer first (if available) and then reads from the underlying reader.
 func (r *BufferedReader) Read(b []byte) (int, error) {
-	if r.Buffer != nil {
-		nBytes, _ := r.Buffer.Read(b)
+	if !r.Buffer.IsEmpty() {
+		nBytes, err := r.Buffer.Read(b)
+		common.Must(err)
 		if r.Buffer.IsEmpty() {
 			r.Buffer.Release()
 			r.Buffer = nil
@@ -113,19 +114,21 @@ func (r *BufferedReader) Read(b []byte) (int, error) {
 	}
 
 	mb, err := r.Reader.ReadMultiBuffer()
-	if mb != nil {
-		nBytes, _ := mb.Read(b)
-		if !mb.IsEmpty() {
-			r.Buffer = mb
-		}
-		return nBytes, err
+	if err != nil {
+		return 0, err
 	}
-	return 0, err
+
+	nBytes, err := mb.Read(b)
+	common.Must(err)
+	if !mb.IsEmpty() {
+		r.Buffer = mb
+	}
+	return nBytes, err
 }
 
 // ReadMultiBuffer implements Reader.
 func (r *BufferedReader) ReadMultiBuffer() (MultiBuffer, error) {
-	if r.Buffer != nil {
+	if !r.Buffer.IsEmpty() {
 		mb := r.Buffer
 		r.Buffer = nil
 		return mb, nil
@@ -136,7 +139,7 @@ func (r *BufferedReader) ReadMultiBuffer() (MultiBuffer, error) {
 
 // ReadAtMost returns a MultiBuffer with at most size.
 func (r *BufferedReader) ReadAtMost(size int32) (MultiBuffer, error) {
-	if r.Buffer == nil {
+	if r.Buffer.IsEmpty() {
 		mb, err := r.Reader.ReadMultiBuffer()
 		if mb.IsEmpty() && err != nil {
 			return nil, err
diff --git a/transport/internet/kcp/receiving.go b/transport/internet/kcp/receiving.go
index d6a0d063..3bf5ee75 100644
--- a/transport/internet/kcp/receiving.go
+++ b/transport/internet/kcp/receiving.go
@@ -3,6 +3,7 @@ package kcp
 import (
 	"sync"
 
+	"v2ray.com/core/common"
 	"v2ray.com/core/common/buf"
 )
 
@@ -204,7 +205,8 @@ func (w *ReceivingWorker) ReadMultiBuffer() buf.MultiBuffer {
 
 func (w *ReceivingWorker) Read(b []byte) int {
 	mb := w.ReadMultiBuffer()
-	nBytes, _ := mb.Read(b)
+	nBytes, err := mb.Read(b)
+	common.Must(err)
 	if !mb.IsEmpty() {
 		w.leftOver = mb
 	}