From 9875111176f498e5a01fde2149140b8750a39b19 Mon Sep 17 00:00:00 2001
From: Arjan Bal <arjansbal@google.com>
Date: Thu, 16 Oct 2025 16:27:17 +0530
Subject: [PATCH 01/11] changes no tests

---
 internal/transport/http2_client.go   | 37 ++++++-----
 internal/transport/http2_server.go   | 37 ++++++-----
 internal/transport/http_util.go      | 91 +++++++++++++++++++++++++++-
 internal/transport/keepalive_test.go |  3 +-
 4 files changed, 134 insertions(+), 34 deletions(-)

diff --git a/internal/transport/http2_client.go b/internal/transport/http2_client.go
index 911d7e1ea4e3..7fa369d31e37 100644
--- a/internal/transport/http2_client.go
+++ b/internal/transport/http2_client.go
@@ -335,7 +335,7 @@ func NewHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 		writerDone:            make(chan struct{}),
 		goAway:                make(chan struct{}),
 		keepaliveDone:         make(chan struct{}),
-		framer:                newFramer(conn, writeBufSize, readBufSize, opts.SharedWriteBuffer, maxHeaderListSize),
+		framer:                newFramer(conn, writeBufSize, readBufSize, opts.SharedWriteBuffer, maxHeaderListSize, opts.BufferPool),
 		fc:                    &trInFlow{limit: uint32(icwz)},
 		scheme:                scheme,
 		activeStreams:         make(map[uint32]*ClientStream),
@@ -1177,7 +1177,12 @@ func (t *http2Client) updateFlowControl(n uint32) {
 	})
 }
 
-func (t *http2Client) handleData(f *http2.DataFrame) {
+func (t *http2Client) handleData(f *parsedDataFrame) {
+	defer func() {
+		if f.data != nil {
+			f.data.Free()
+		}
+	}()
 	size := f.Header().Length
 	var sendBDPPing bool
 	if t.bdpEst != nil {
@@ -1221,22 +1226,15 @@ func (t *http2Client) handleData(f *http2.DataFrame) {
 			t.closeStream(s, io.EOF, true, http2.ErrCodeFlowControl, status.New(codes.Internal, err.Error()), nil, false)
 			return
 		}
+		dataLen := f.data.Len()
 		if f.Header().Flags.Has(http2.FlagDataPadded) {
-			if w := s.fc.onRead(size - uint32(len(f.Data()))); w > 0 {
+			if w := s.fc.onRead(size - uint32(dataLen)); w > 0 {
 				t.controlBuf.put(&outgoingWindowUpdate{s.id, w})
 			}
 		}
-		// TODO(bradfitz, zhaoq): A copy is required here because there is no
-		// guarantee f.Data() is consumed before the arrival of next frame.
-		// Can this copy be eliminated?
-		if len(f.Data()) > 0 {
-			pool := t.bufferPool
-			if pool == nil {
-				// Note that this is only supposed to be nil in tests. Otherwise, stream is
-				// always initialized with a BufferPool.
-				pool = mem.DefaultBufferPool()
-			}
-			s.write(recvMsg{buffer: mem.Copy(f.Data(), pool)})
+		if dataLen > 0 {
+			s.write(recvMsg{buffer: f.data})
+			f.data = nil
 		}
 	}
 	// The server has closed the stream without sending trailers.  Record that
@@ -1656,6 +1654,13 @@ func (t *http2Client) reader(errCh chan<- error) {
 		}
 	}()
 
+	pool := t.bufferPool
+	if pool == nil {
+		// Note that this is only supposed to be nil in tests. Otherwise, stream
+		// is always initialized with a BufferPool.
+		pool = mem.DefaultBufferPool()
+	}
+
 	if err := t.readServerPreface(); err != nil {
 		errCh <- err
 		return
@@ -1668,7 +1673,7 @@ func (t *http2Client) reader(errCh chan<- error) {
 	// loop to keep reading incoming messages on this transport.
 	for {
 		t.controlBuf.throttle()
-		frame, err := t.framer.fr.ReadFrame()
+		frame, err := t.framer.readFrame()
 		if t.keepaliveEnabled {
 			atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 		}
@@ -1701,7 +1706,7 @@ func (t *http2Client) reader(errCh chan<- error) {
 		switch frame := frame.(type) {
 		case *http2.MetaHeadersFrame:
 			t.operateHeaders(frame)
-		case *http2.DataFrame:
+		case *parsedDataFrame:
 			t.handleData(frame)
 		case *http2.RSTStreamFrame:
 			t.handleRSTStream(frame)
diff --git a/internal/transport/http2_server.go b/internal/transport/http2_server.go
index bcedac32fed5..edcf9ecc8b9b 100644
--- a/internal/transport/http2_server.go
+++ b/internal/transport/http2_server.go
@@ -169,7 +169,8 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 	if config.MaxHeaderListSize != nil {
 		maxHeaderListSize = *config.MaxHeaderListSize
 	}
-	framer := newFramer(conn, writeBufSize, readBufSize, config.SharedWriteBuffer, maxHeaderListSize)
+
+	framer := newFramer(conn, writeBufSize, readBufSize, config.SharedWriteBuffer, maxHeaderListSize, config.BufferPool)
 	// Send initial settings as connection preface to client.
 	isettings := []http2.Setting{{
 		ID:  http2.SettingMaxFrameSize,
@@ -668,10 +669,16 @@ func (t *http2Server) HandleStreams(ctx context.Context, handle func(*ServerStre
 		close(t.readerDone)
 		<-t.loopyWriterDone
 	}()
+	pool := t.bufferPool
+	if pool == nil {
+		// Note that this is only supposed to be nil in tests. Otherwise, stream
+		// is always initialized with a BufferPool.
+		pool = mem.DefaultBufferPool()
+	}
 	for {
 		t.controlBuf.throttle()
-		frame, err := t.framer.fr.ReadFrame()
 		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
+		frame, err := t.framer.readFrame()
 		if err != nil {
 			if se, ok := err.(http2.StreamError); ok {
 				if t.logger.V(logLevel) {
@@ -707,7 +714,7 @@ func (t *http2Server) HandleStreams(ctx context.Context, handle func(*ServerStre
 				})
 				continue
 			}
-		case *http2.DataFrame:
+		case *parsedDataFrame:
 			t.handleData(frame)
 		case *http2.RSTStreamFrame:
 			t.handleRSTStream(frame)
@@ -788,7 +795,12 @@ func (t *http2Server) updateFlowControl(n uint32) {
 
 }
 
-func (t *http2Server) handleData(f *http2.DataFrame) {
+func (t *http2Server) handleData(f *parsedDataFrame) {
+	defer func() {
+		if f.data != nil {
+			f.data.Free()
+		}
+	}()
 	size := f.Header().Length
 	var sendBDPPing bool
 	if t.bdpEst != nil {
@@ -833,22 +845,15 @@ func (t *http2Server) handleData(f *http2.DataFrame) {
 			t.closeStream(s, true, http2.ErrCodeFlowControl, false)
 			return
 		}
+		dataLen := f.data.Len()
 		if f.Header().Flags.Has(http2.FlagDataPadded) {
-			if w := s.fc.onRead(size - uint32(len(f.Data()))); w > 0 {
+			if w := s.fc.onRead(size - uint32(dataLen)); w > 0 {
 				t.controlBuf.put(&outgoingWindowUpdate{s.id, w})
 			}
 		}
-		// TODO(bradfitz, zhaoq): A copy is required here because there is no
-		// guarantee f.Data() is consumed before the arrival of next frame.
-		// Can this copy be eliminated?
-		if len(f.Data()) > 0 {
-			pool := t.bufferPool
-			if pool == nil {
-				// Note that this is only supposed to be nil in tests. Otherwise, stream is
-				// always initialized with a BufferPool.
-				pool = mem.DefaultBufferPool()
-			}
-			s.write(recvMsg{buffer: mem.Copy(f.Data(), pool)})
+		if dataLen > 0 {
+			s.write(recvMsg{buffer: f.data})
+			f.data = nil
 		}
 	}
 	if f.StreamEnded() {
diff --git a/internal/transport/http_util.go b/internal/transport/http_util.go
index e3663f87f391..05c23827c2ef 100644
--- a/internal/transport/http_util.go
+++ b/internal/transport/http_util.go
@@ -37,6 +37,7 @@ import (
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
 	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/mem"
 )
 
 const (
@@ -388,15 +389,34 @@ func toIOError(err error) error {
 	return ioError{error: err}
 }
 
+type parsedDataFrame struct {
+	http2.FrameHeader
+	data mem.Buffer
+}
+
+func (df *parsedDataFrame) StreamEnded() bool {
+	return df.FrameHeader.Flags.Has(http2.FlagDataEndStream)
+}
+
 type framer struct {
 	writer *bufWriter
 	fr     *http2.Framer
+	reader io.Reader
+	// Cached data frame to avoid heap allocations.
+	dataFrame parsedDataFrame
+	pool      mem.BufferPool
 }
 
 var writeBufferPoolMap = make(map[int]*sync.Pool)
 var writeBufferMutex sync.Mutex
 
-func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, sharedWriteBuffer bool, maxHeaderListSize uint32) *framer {
+func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, sharedWriteBuffer bool, maxHeaderListSize uint32, memPool mem.BufferPool) *framer {
+	if memPool == nil {
+		// Note that this is only supposed to be nil in tests. Otherwise, stream
+		// is always initialized with a BufferPool.
+		memPool = mem.DefaultBufferPool()
+	}
+
 	if writeBufferSize < 0 {
 		writeBufferSize = 0
 	}
@@ -412,6 +432,8 @@ func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, sharedWriteBu
 	f := &framer{
 		writer: w,
 		fr:     http2.NewFramer(w, r),
+		reader: r,
+		pool:   memPool,
 	}
 	f.fr.SetMaxReadFrameSize(http2MaxFrameLen)
 	// Opt-in to Frame reuse API on framer to reduce garbage.
@@ -422,6 +444,73 @@ func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, sharedWriteBu
 	return f
 }
 
+func (f *framer) readFrame() (any, error) {
+	fh, err := f.fr.ReadFrameHeader()
+	if err != nil {
+		return nil, err
+	}
+	if fh.Type == http2.FrameData {
+		err = f.readDataFrame(fh, f.pool, &f.dataFrame)
+		return &f.dataFrame, err
+	} else {
+		return f.fr.ReadFrameForHeader(fh)
+	}
+}
+
+// readDataFrame reads and parses a data frame from the underlying io.Reader.
+// Frames aren't safe to read from after a subsequent call to ReadFrame.
+func (f *framer) readDataFrame(fh http2.FrameHeader, pool mem.BufferPool, df *parsedDataFrame) (err error) {
+	if fh.StreamID == 0 {
+		// DATA frames MUST be associated with a stream. If a
+		// DATA frame is received whose stream identifier
+		// field is 0x0, the recipient MUST respond with a
+		// connection error (Section 5.4.1) of type
+		// PROTOCOL_ERROR.
+		return fmt.Errorf("DATA frame with stream ID 0")
+	}
+	payload := pool.Get(int(fh.Length))
+	defer func() {
+		if err != nil {
+			f.pool.Put(payload)
+		}
+	}()
+	if fh.Flags.Has(http2.FlagDataPadded) {
+		if fh.Length == 0 {
+			return io.ErrUnexpectedEOF
+		}
+		// This initial 1-byte read can be inefficient for unbuffered readers,
+		// but it allows the rest of the payload to be read directly to the
+		// start of the destination slice. This makes it easy to return the
+		// original slice back to the buffer pool.
+		if _, err := io.ReadFull(f.reader, (*payload)[:1]); err != nil {
+			return err
+		}
+		padSize := (*payload)[0]
+		*payload = (*payload)[:len(*payload)-1]
+		if _, err := io.ReadFull(f.reader, *payload); err != nil {
+			return err
+		}
+		if int(padSize) > len(*payload) {
+			// If the length of the padding is greater than the
+			// length of the frame payload, the recipient MUST
+			// treat this as a connection error.
+			// Filed: https://github.com/http2/http2-spec/issues/610
+			return fmt.Errorf("pad size larger than data payload")
+		}
+		*payload = (*payload)[:len(*payload)-int(padSize)]
+	} else if _, err := io.ReadFull(f.reader, *payload); err != nil {
+		return err
+	}
+
+	df.FrameHeader = fh
+	df.data = mem.NewBuffer(payload, pool)
+	return nil
+}
+
+func (df *parsedDataFrame) Header() http2.FrameHeader {
+	return df.FrameHeader
+}
+
 func getWriteBufferPool(size int) *sync.Pool {
 	writeBufferMutex.Lock()
 	defer writeBufferMutex.Unlock()
diff --git a/internal/transport/keepalive_test.go b/internal/transport/keepalive_test.go
index 0bd7ba356b3c..962db8dfe583 100644
--- a/internal/transport/keepalive_test.go
+++ b/internal/transport/keepalive_test.go
@@ -40,6 +40,7 @@ import (
 	"google.golang.org/grpc/internal/grpctest"
 	"google.golang.org/grpc/internal/syscall"
 	"google.golang.org/grpc/keepalive"
+	"google.golang.org/grpc/mem"
 	"google.golang.org/grpc/testdata"
 )
 
@@ -192,7 +193,7 @@ func (s) TestKeepaliveServerClosesUnresponsiveClient(t *testing.T) {
 	if n, err := conn.Write(clientPreface); err != nil || n != len(clientPreface) {
 		t.Fatalf("conn.Write(clientPreface) failed: n=%v, err=%v", n, err)
 	}
-	framer := newFramer(conn, defaultWriteBufSize, defaultReadBufSize, false, 0)
+	framer := newFramer(conn, defaultWriteBufSize, defaultReadBufSize, false, 0, mem.DefaultBufferPool())
 	if err := framer.fr.WriteSettings(http2.Setting{}); err != nil {
 		t.Fatal("framer.WriteSettings(http2.Setting{}) failed:", err)
 	}

From a6f1b72e8c81bf11365457606523902aa71d3401 Mon Sep 17 00:00:00 2001
From: Arjan Bal <arjansbal@google.com>
Date: Thu, 16 Oct 2025 18:19:36 +0530
Subject: [PATCH 02/11] tests

---
 internal/transport/http_util.go      |  7 ++-
 internal/transport/http_util_test.go | 77 ++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+), 4 deletions(-)

diff --git a/internal/transport/http_util.go b/internal/transport/http_util.go
index 05c23827c2ef..7f924f3e4d5a 100644
--- a/internal/transport/http_util.go
+++ b/internal/transport/http_util.go
@@ -25,7 +25,6 @@ import (
 	"fmt"
 	"io"
 	"math"
-	"net"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -301,11 +300,11 @@ type bufWriter struct {
 	buf       []byte
 	offset    int
 	batchSize int
-	conn      net.Conn
+	conn      io.ReadWriter
 	err       error
 }
 
-func newBufWriter(conn net.Conn, batchSize int, pool *sync.Pool) *bufWriter {
+func newBufWriter(conn io.ReadWriter, batchSize int, pool *sync.Pool) *bufWriter {
 	w := &bufWriter{
 		batchSize: batchSize,
 		conn:      conn,
@@ -410,7 +409,7 @@ type framer struct {
 var writeBufferPoolMap = make(map[int]*sync.Pool)
 var writeBufferMutex sync.Mutex
 
-func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, sharedWriteBuffer bool, maxHeaderListSize uint32, memPool mem.BufferPool) *framer {
+func newFramer(conn io.ReadWriter, writeBufferSize, readBufferSize int, sharedWriteBuffer bool, maxHeaderListSize uint32, memPool mem.BufferPool) *framer {
 	if memPool == nil {
 		// Note that this is only supposed to be nil in tests. Otherwise, stream
 		// is always initialized with a BufferPool.
diff --git a/internal/transport/http_util_test.go b/internal/transport/http_util_test.go
index 7fb2cdf46100..69e631d8b215 100644
--- a/internal/transport/http_util_test.go
+++ b/internal/transport/http_util_test.go
@@ -19,6 +19,7 @@
 package transport
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"io"
@@ -27,6 +28,8 @@ import (
 	"reflect"
 	"testing"
 	"time"
+
+	"google.golang.org/grpc/mem"
 )
 
 func (s) TestDecodeTimeout(t *testing.T) {
@@ -295,3 +298,77 @@ func BenchmarkEncodeGrpcMessage(b *testing.B) {
 		}
 	}
 }
+
+func (s) TestFrame_ReadDataFrame(t *testing.T) {
+	tests := []struct {
+		name     string
+		w        func(fr *framer) error
+		wantData []byte
+		wantErr  bool
+	}{
+		{
+			name: "good_padded",
+			w: func(fr *framer) error {
+				return fr.fr.WriteDataPadded(1, false, []byte("foo"), []byte{0, 0})
+			},
+			wantData: []byte("foo"),
+		},
+		{
+			name: "good_unpadded",
+			w: func(fr *framer) error {
+				return fr.fr.WriteData(1, false, []byte("foo"))
+			},
+			wantData: []byte("foo"),
+		},
+		{
+			name: "padded_zero_data_some_padding",
+			w: func(fr *framer) error {
+				return fr.fr.WriteDataPadded(1, false, []byte{}, []byte{0, 0})
+			},
+			wantData: []byte{},
+		},
+		{
+			name: "stream_id_0",
+			w: func(fr *framer) error {
+				fr.fr.AllowIllegalWrites = true
+				return fr.fr.WriteData(0, false, []byte("foo"))
+			},
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			fr, _ := testFramer()
+			// Write the frame using the provided function.
+			writeErr := tt.w(fr)
+			if writeErr != nil {
+				t.Fatalf("tt.w() returned unexpected error: %v", writeErr)
+			}
+			fr.writer.Flush()
+
+			// Read the frame back.
+			f, err := fr.readFrame()
+			if gotErr := err != nil; gotErr != tt.wantErr {
+				t.Fatalf("ReadFrame() err = %v; want %t", err, tt.wantErr)
+			}
+			if tt.wantErr {
+				return
+			}
+
+			df, ok := f.(*parsedDataFrame)
+			if !ok {
+				t.Fatalf("ReadFrame() returned %T, want *parsedDataFrame", f)
+			}
+			if gotData := df.data.ReadOnlyData(); !bytes.Equal(gotData, tt.wantData) {
+				t.Fatalf("parsedDataFrame.Data() = %q, want %q", gotData, tt.wantData)
+			}
+			df.data.Free()
+		})
+	}
+}
+
+func testFramer() (*framer, *bytes.Buffer) {
+	buf := new(bytes.Buffer)
+	return newFramer(buf, defaultWriteBufSize, defaultReadBufSize, false, defaultClientMaxHeaderListSize, mem.DefaultBufferPool()), buf
+}

From 3f984714f6740db652da42decf1d60d413eac296 Mon Sep 17 00:00:00 2001
From: Arjan Bal <arjansbal@google.com>
Date: Thu, 16 Oct 2025 18:21:37 +0530
Subject: [PATCH 03/11] cleanup

---
 internal/transport/http2_client.go | 7 -------
 internal/transport/http2_server.go | 9 +--------
 internal/transport/http_util.go    | 9 +++++----
 3 files changed, 6 insertions(+), 19 deletions(-)

diff --git a/internal/transport/http2_client.go b/internal/transport/http2_client.go
index 7fa369d31e37..926a5d4f00d4 100644
--- a/internal/transport/http2_client.go
+++ b/internal/transport/http2_client.go
@@ -1654,13 +1654,6 @@ func (t *http2Client) reader(errCh chan<- error) {
 		}
 	}()
 
-	pool := t.bufferPool
-	if pool == nil {
-		// Note that this is only supposed to be nil in tests. Otherwise, stream
-		// is always initialized with a BufferPool.
-		pool = mem.DefaultBufferPool()
-	}
-
 	if err := t.readServerPreface(); err != nil {
 		errCh <- err
 		return
diff --git a/internal/transport/http2_server.go b/internal/transport/http2_server.go
index edcf9ecc8b9b..cd01dc82b470 100644
--- a/internal/transport/http2_server.go
+++ b/internal/transport/http2_server.go
@@ -169,7 +169,6 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 	if config.MaxHeaderListSize != nil {
 		maxHeaderListSize = *config.MaxHeaderListSize
 	}
-
 	framer := newFramer(conn, writeBufSize, readBufSize, config.SharedWriteBuffer, maxHeaderListSize, config.BufferPool)
 	// Send initial settings as connection preface to client.
 	isettings := []http2.Setting{{
@@ -669,16 +668,10 @@ func (t *http2Server) HandleStreams(ctx context.Context, handle func(*ServerStre
 		close(t.readerDone)
 		<-t.loopyWriterDone
 	}()
-	pool := t.bufferPool
-	if pool == nil {
-		// Note that this is only supposed to be nil in tests. Otherwise, stream
-		// is always initialized with a BufferPool.
-		pool = mem.DefaultBufferPool()
-	}
 	for {
 		t.controlBuf.throttle()
-		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 		frame, err := t.framer.readFrame()
+		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 		if err != nil {
 			if se, ok := err.(http2.StreamError); ok {
 				if t.logger.V(logLevel) {
diff --git a/internal/transport/http_util.go b/internal/transport/http_util.go
index 7f924f3e4d5a..c1ea41fc84cd 100644
--- a/internal/transport/http_util.go
+++ b/internal/transport/http_util.go
@@ -443,21 +443,22 @@ func newFramer(conn io.ReadWriter, writeBufferSize, readBufferSize int, sharedWr
 	return f
 }
 
+// readFrame reads a single frame. The returned Frame is only valid
+// until the next call to readFrame.
 func (f *framer) readFrame() (any, error) {
 	fh, err := f.fr.ReadFrameHeader()
 	if err != nil {
 		return nil, err
 	}
+	// Read the data frame directly from the underlying io.Reader to avoid
+	// copies.
 	if fh.Type == http2.FrameData {
 		err = f.readDataFrame(fh, f.pool, &f.dataFrame)
 		return &f.dataFrame, err
-	} else {
-		return f.fr.ReadFrameForHeader(fh)
 	}
+	return f.fr.ReadFrameForHeader(fh)
 }
 
-// readDataFrame reads and parses a data frame from the underlying io.Reader.
-// Frames aren't safe to read from after a subsequent call to ReadFrame.
 func (f *framer) readDataFrame(fh http2.FrameHeader, pool mem.BufferPool, df *parsedDataFrame) (err error) {
 	if fh.StreamID == 0 {
 		// DATA frames MUST be associated with a stream. If a

From 5fa01cd30b73cd2b3d638e56271c8df2ab83b09b Mon Sep 17 00:00:00 2001
From: Arjan Bal <arjansbal@google.com>
Date: Thu, 16 Oct 2025 23:35:48 +0530
Subject: [PATCH 04/11] eliminate extra heap alloc

---
 internal/transport/http2_client.go |  8 ++---
 internal/transport/http2_server.go |  8 ++---
 internal/transport/http_util.go    | 53 ++++++++++++++++++++----------
 3 files changed, 40 insertions(+), 29 deletions(-)

diff --git a/internal/transport/http2_client.go b/internal/transport/http2_client.go
index 926a5d4f00d4..cff2c616ad21 100644
--- a/internal/transport/http2_client.go
+++ b/internal/transport/http2_client.go
@@ -1178,11 +1178,6 @@ func (t *http2Client) updateFlowControl(n uint32) {
 }
 
 func (t *http2Client) handleData(f *parsedDataFrame) {
-	defer func() {
-		if f.data != nil {
-			f.data.Free()
-		}
-	}()
 	size := f.Header().Length
 	var sendBDPPing bool
 	if t.bdpEst != nil {
@@ -1233,8 +1228,8 @@ func (t *http2Client) handleData(f *parsedDataFrame) {
 			}
 		}
 		if dataLen > 0 {
+			f.data.Ref()
 			s.write(recvMsg{buffer: f.data})
-			f.data = nil
 		}
 	}
 	// The server has closed the stream without sending trailers.  Record that
@@ -1701,6 +1696,7 @@ func (t *http2Client) reader(errCh chan<- error) {
 			t.operateHeaders(frame)
 		case *parsedDataFrame:
 			t.handleData(frame)
+			frame.data.Free()
 		case *http2.RSTStreamFrame:
 			t.handleRSTStream(frame)
 		case *http2.SettingsFrame:
diff --git a/internal/transport/http2_server.go b/internal/transport/http2_server.go
index cd01dc82b470..d12c7af2f910 100644
--- a/internal/transport/http2_server.go
+++ b/internal/transport/http2_server.go
@@ -709,6 +709,7 @@ func (t *http2Server) HandleStreams(ctx context.Context, handle func(*ServerStre
 			}
 		case *parsedDataFrame:
 			t.handleData(frame)
+			frame.data.Free()
 		case *http2.RSTStreamFrame:
 			t.handleRSTStream(frame)
 		case *http2.SettingsFrame:
@@ -789,11 +790,6 @@ func (t *http2Server) updateFlowControl(n uint32) {
 }
 
 func (t *http2Server) handleData(f *parsedDataFrame) {
-	defer func() {
-		if f.data != nil {
-			f.data.Free()
-		}
-	}()
 	size := f.Header().Length
 	var sendBDPPing bool
 	if t.bdpEst != nil {
@@ -845,8 +841,8 @@ func (t *http2Server) handleData(f *parsedDataFrame) {
 			}
 		}
 		if dataLen > 0 {
+			f.data.Ref()
 			s.write(recvMsg{buffer: f.data})
-			f.data = nil
 		}
 	}
 	if f.StreamEnded() {
diff --git a/internal/transport/http_util.go b/internal/transport/http_util.go
index c1ea41fc84cd..f4159690a203 100644
--- a/internal/transport/http_util.go
+++ b/internal/transport/http_util.go
@@ -453,13 +453,13 @@ func (f *framer) readFrame() (any, error) {
 	// Read the data frame directly from the underlying io.Reader to avoid
 	// copies.
 	if fh.Type == http2.FrameData {
-		err = f.readDataFrame(fh, f.pool, &f.dataFrame)
+		err = f.readDataFrame(fh)
 		return &f.dataFrame, err
 	}
 	return f.fr.ReadFrameForHeader(fh)
 }
 
-func (f *framer) readDataFrame(fh http2.FrameHeader, pool mem.BufferPool, df *parsedDataFrame) (err error) {
+func (f *framer) readDataFrame(fh http2.FrameHeader) (err error) {
 	if fh.StreamID == 0 {
 		// DATA frames MUST be associated with a stream. If a
 		// DATA frame is received whose stream identifier
@@ -468,12 +468,25 @@ func (f *framer) readDataFrame(fh http2.FrameHeader, pool mem.BufferPool, df *pa
 		// PROTOCOL_ERROR.
 		return fmt.Errorf("DATA frame with stream ID 0")
 	}
-	payload := pool.Get(int(fh.Length))
-	defer func() {
-		if err != nil {
-			f.pool.Put(payload)
-		}
-	}()
+	// Converting a *[]byte to a mem.BufferSlice incurs a heap allocation. This
+	// conversion is performed by mem.NewBuffer. To avoid the extra allocation
+	// a []byte is allocated directly if required and casted to a
+	// mem.BufferSlice.
+	var buf []byte
+	// poolHandle is the pointer returned by the buffer pool (if it's used.).
+	var poolHandle *[]byte
+	useBufferPool := !mem.IsBelowBufferPoolingThreshold(int(fh.Length))
+	if useBufferPool {
+		poolHandle = f.pool.Get(int(fh.Length))
+		buf = *poolHandle
+		defer func() {
+			if err != nil {
+				f.pool.Put(poolHandle)
+			}
+		}()
+	} else {
+		buf = make([]byte, int(fh.Length))
+	}
 	if fh.Flags.Has(http2.FlagDataPadded) {
 		if fh.Length == 0 {
 			return io.ErrUnexpectedEOF
@@ -482,28 +495,34 @@ func (f *framer) readDataFrame(fh http2.FrameHeader, pool mem.BufferPool, df *pa
 		// but it allows the rest of the payload to be read directly to the
 		// start of the destination slice. This makes it easy to return the
 		// original slice back to the buffer pool.
-		if _, err := io.ReadFull(f.reader, (*payload)[:1]); err != nil {
+		if _, err := io.ReadFull(f.reader, buf[:1]); err != nil {
 			return err
 		}
-		padSize := (*payload)[0]
-		*payload = (*payload)[:len(*payload)-1]
-		if _, err := io.ReadFull(f.reader, *payload); err != nil {
+		padSize := buf[0]
+		buf = buf[:len(buf)-1]
+		if _, err := io.ReadFull(f.reader, buf); err != nil {
 			return err
 		}
-		if int(padSize) > len(*payload) {
+		if int(padSize) > len(buf) {
 			// If the length of the padding is greater than the
 			// length of the frame payload, the recipient MUST
 			// treat this as a connection error.
 			// Filed: https://github.com/http2/http2-spec/issues/610
 			return fmt.Errorf("pad size larger than data payload")
 		}
-		*payload = (*payload)[:len(*payload)-int(padSize)]
-	} else if _, err := io.ReadFull(f.reader, *payload); err != nil {
+		buf = buf[:len(buf)-int(padSize)]
+	} else if _, err := io.ReadFull(f.reader, buf); err != nil {
 		return err
 	}
 
-	df.FrameHeader = fh
-	df.data = mem.NewBuffer(payload, pool)
+	f.dataFrame.FrameHeader = fh
+	if useBufferPool {
+		// Update the handle to point to the (potentially re-sliced) buf.
+		*poolHandle = buf
+		f.dataFrame.data = mem.NewBuffer(poolHandle, f.pool)
+	} else {
+		f.dataFrame.data = mem.SliceBuffer(buf)
+	}
 	return nil
 }
 

From 5ec4a4eb851841fd2dc36c2cd53cc5780fb486b5 Mon Sep 17 00:00:00 2001
From: Arjan Bal <arjansbal@google.com>
Date: Fri, 17 Oct 2025 00:42:05 +0530
Subject: [PATCH 05/11] bump x/net to golang.org/x/net@63d1a51

---
 examples/go.mod                      | 2 +-
 examples/go.sum                      | 4 ++--
 gcp/observability/go.mod             | 2 +-
 gcp/observability/go.sum             | 4 ++--
 go.mod                               | 2 +-
 go.sum                               | 4 ++--
 interop/observability/go.mod         | 2 +-
 interop/observability/go.sum         | 4 ++--
 interop/xds/go.mod                   | 2 +-
 interop/xds/go.sum                   | 4 ++--
 security/advancedtls/examples/go.mod | 2 +-
 security/advancedtls/examples/go.sum | 4 ++--
 security/advancedtls/go.mod          | 2 +-
 security/advancedtls/go.sum          | 4 ++--
 stats/opencensus/go.mod              | 2 +-
 stats/opencensus/go.sum              | 4 ++--
 16 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/examples/go.mod b/examples/go.mod
index 1ce603d05832..8272a93043ac 100644
--- a/examples/go.mod
+++ b/examples/go.mod
@@ -74,7 +74,7 @@ require (
 	go.opentelemetry.io/otel/trace v1.38.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.3 // indirect
 	golang.org/x/crypto v0.43.0 // indirect
-	golang.org/x/net v0.46.0 // indirect
+	golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 // indirect
 	golang.org/x/sync v0.17.0 // indirect
 	golang.org/x/sys v0.37.0 // indirect
 	golang.org/x/text v0.30.0 // indirect
diff --git a/examples/go.sum b/examples/go.sum
index 642f08f234f4..bdaa5815653b 100644
--- a/examples/go.sum
+++ b/examples/go.sum
@@ -4122,8 +4122,8 @@ golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8=
 golang.org/x/net v0.43.0/go.mod h1:vhO1fvI4dGsIjh73sWfUVjj3N7CA9WkKJNQm2svM6Jg=
 golang.org/x/net v0.44.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
 golang.org/x/net v0.45.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
-golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
-golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20191202225959-858c2ad4c8b6/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
diff --git a/gcp/observability/go.mod b/gcp/observability/go.mod
index 175d3be745aa..a2214f32d32b 100644
--- a/gcp/observability/go.mod
+++ b/gcp/observability/go.mod
@@ -51,7 +51,7 @@ require (
 	go.opentelemetry.io/otel/metric v1.38.0 // indirect
 	go.opentelemetry.io/otel/trace v1.38.0 // indirect
 	golang.org/x/crypto v0.43.0 // indirect
-	golang.org/x/net v0.46.0 // indirect
+	golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 // indirect
 	golang.org/x/sync v0.17.0 // indirect
 	golang.org/x/sys v0.37.0 // indirect
 	golang.org/x/text v0.30.0 // indirect
diff --git a/gcp/observability/go.sum b/gcp/observability/go.sum
index a0fac0011fd9..e4037d61ac73 100644
--- a/gcp/observability/go.sum
+++ b/gcp/observability/go.sum
@@ -3810,8 +3810,8 @@ golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8=
 golang.org/x/net v0.43.0/go.mod h1:vhO1fvI4dGsIjh73sWfUVjj3N7CA9WkKJNQm2svM6Jg=
 golang.org/x/net v0.44.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
 golang.org/x/net v0.45.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
-golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
-golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20191202225959-858c2ad4c8b6/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
diff --git a/go.mod b/go.mod
index 282140722fdb..fd73ec7d9a94 100644
--- a/go.mod
+++ b/go.mod
@@ -18,7 +18,7 @@ require (
 	go.opentelemetry.io/otel/sdk v1.38.0
 	go.opentelemetry.io/otel/sdk/metric v1.38.0
 	go.opentelemetry.io/otel/trace v1.38.0
-	golang.org/x/net v0.46.0
+	golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82
 	golang.org/x/oauth2 v0.32.0
 	golang.org/x/sync v0.17.0
 	golang.org/x/sys v0.37.0
diff --git a/go.sum b/go.sum
index 93e1044da556..4196237e1ff1 100644
--- a/go.sum
+++ b/go.sum
@@ -57,8 +57,8 @@ go.opentelemetry.io/otel/trace v1.38.0 h1:Fxk5bKrDZJUH+AMyyIXGcFAPah0oRcT+LuNtJr
 go.opentelemetry.io/otel/trace v1.38.0/go.mod h1:j1P9ivuFsTceSWe1oY+EeW3sc+Pp42sO++GHkg4wwhs=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
-golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
-golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.32.0 h1:jsCblLleRMDrxMN29H3z/k1KliIvpLgCkE6R8FXXNgY=
 golang.org/x/oauth2 v0.32.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwEA=
 golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
diff --git a/interop/observability/go.mod b/interop/observability/go.mod
index 33a609634c11..963c9ee16c7a 100644
--- a/interop/observability/go.mod
+++ b/interop/observability/go.mod
@@ -50,7 +50,7 @@ require (
 	go.opentelemetry.io/otel/metric v1.38.0 // indirect
 	go.opentelemetry.io/otel/trace v1.38.0 // indirect
 	golang.org/x/crypto v0.43.0 // indirect
-	golang.org/x/net v0.46.0 // indirect
+	golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 // indirect
 	golang.org/x/oauth2 v0.32.0 // indirect
 	golang.org/x/sync v0.17.0 // indirect
 	golang.org/x/sys v0.37.0 // indirect
diff --git a/interop/observability/go.sum b/interop/observability/go.sum
index f146e0f9c1ba..493b7abefdd6 100644
--- a/interop/observability/go.sum
+++ b/interop/observability/go.sum
@@ -4092,8 +4092,8 @@ golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8=
 golang.org/x/net v0.43.0/go.mod h1:vhO1fvI4dGsIjh73sWfUVjj3N7CA9WkKJNQm2svM6Jg=
 golang.org/x/net v0.44.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
 golang.org/x/net v0.45.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
-golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
-golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20191202225959-858c2ad4c8b6/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
diff --git a/interop/xds/go.mod b/interop/xds/go.mod
index f88612750dc0..91766ca4b00b 100644
--- a/interop/xds/go.mod
+++ b/interop/xds/go.mod
@@ -38,7 +38,7 @@ require (
 	go.opentelemetry.io/otel/sdk v1.38.0 // indirect
 	go.opentelemetry.io/otel/trace v1.38.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.3 // indirect
-	golang.org/x/net v0.46.0 // indirect
+	golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 // indirect
 	golang.org/x/oauth2 v0.32.0 // indirect
 	golang.org/x/sync v0.17.0 // indirect
 	golang.org/x/sys v0.37.0 // indirect
diff --git a/interop/xds/go.sum b/interop/xds/go.sum
index f4ac6ac72af1..d2d0cc57219e 100644
--- a/interop/xds/go.sum
+++ b/interop/xds/go.sum
@@ -83,8 +83,8 @@ go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 go.yaml.in/yaml/v2 v2.4.3 h1:6gvOSjQoTB3vt1l+CU+tSyi/HOjfOjRLJ4YwYZGwRO0=
 go.yaml.in/yaml/v2 v2.4.3/go.mod h1:zSxWcmIDjOzPXpjlTTbAsKokqkDNAVtZO0WOMiT90s8=
-golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
-golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.32.0 h1:jsCblLleRMDrxMN29H3z/k1KliIvpLgCkE6R8FXXNgY=
 golang.org/x/oauth2 v0.32.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwEA=
 golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
diff --git a/security/advancedtls/examples/go.mod b/security/advancedtls/examples/go.mod
index 362458c29b69..5e89b35a7855 100644
--- a/security/advancedtls/examples/go.mod
+++ b/security/advancedtls/examples/go.mod
@@ -12,7 +12,7 @@ require (
 	github.com/go-jose/go-jose/v4 v4.1.3 // indirect
 	github.com/spiffe/go-spiffe/v2 v2.6.0 // indirect
 	golang.org/x/crypto v0.43.0 // indirect
-	golang.org/x/net v0.46.0 // indirect
+	golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 // indirect
 	golang.org/x/sys v0.37.0 // indirect
 	golang.org/x/text v0.30.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20251014184007-4626949a642f // indirect
diff --git a/security/advancedtls/examples/go.sum b/security/advancedtls/examples/go.sum
index 4ca2f35546c8..b89e389616c5 100644
--- a/security/advancedtls/examples/go.sum
+++ b/security/advancedtls/examples/go.sum
@@ -32,8 +32,8 @@ go.opentelemetry.io/otel/trace v1.38.0 h1:Fxk5bKrDZJUH+AMyyIXGcFAPah0oRcT+LuNtJr
 go.opentelemetry.io/otel/trace v1.38.0/go.mod h1:j1P9ivuFsTceSWe1oY+EeW3sc+Pp42sO++GHkg4wwhs=
 golang.org/x/crypto v0.43.0 h1:dduJYIi3A3KOfdGOHX8AVZ/jGiyPa3IbBozJ5kNuE04=
 golang.org/x/crypto v0.43.0/go.mod h1:BFbav4mRNlXJL4wNeejLpWxB7wMbc79PdRGhWKncxR0=
-golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
-golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/sys v0.37.0 h1:fdNQudmxPjkdUTPnLn5mdQv7Zwvbvpaxqs831goi9kQ=
 golang.org/x/sys v0.37.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.org/x/text v0.30.0 h1:yznKA/E9zq54KzlzBEAWn1NXSQ8DIp/NYMy88xJjl4k=
diff --git a/security/advancedtls/go.mod b/security/advancedtls/go.mod
index 8f8234562392..58649f15a8a4 100644
--- a/security/advancedtls/go.mod
+++ b/security/advancedtls/go.mod
@@ -12,7 +12,7 @@ require (
 require (
 	github.com/go-jose/go-jose/v4 v4.1.3 // indirect
 	github.com/spiffe/go-spiffe/v2 v2.6.0 // indirect
-	golang.org/x/net v0.46.0 // indirect
+	golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 // indirect
 	golang.org/x/sys v0.37.0 // indirect
 	golang.org/x/text v0.30.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20251014184007-4626949a642f // indirect
diff --git a/security/advancedtls/go.sum b/security/advancedtls/go.sum
index 4ca2f35546c8..b89e389616c5 100644
--- a/security/advancedtls/go.sum
+++ b/security/advancedtls/go.sum
@@ -32,8 +32,8 @@ go.opentelemetry.io/otel/trace v1.38.0 h1:Fxk5bKrDZJUH+AMyyIXGcFAPah0oRcT+LuNtJr
 go.opentelemetry.io/otel/trace v1.38.0/go.mod h1:j1P9ivuFsTceSWe1oY+EeW3sc+Pp42sO++GHkg4wwhs=
 golang.org/x/crypto v0.43.0 h1:dduJYIi3A3KOfdGOHX8AVZ/jGiyPa3IbBozJ5kNuE04=
 golang.org/x/crypto v0.43.0/go.mod h1:BFbav4mRNlXJL4wNeejLpWxB7wMbc79PdRGhWKncxR0=
-golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
-golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/sys v0.37.0 h1:fdNQudmxPjkdUTPnLn5mdQv7Zwvbvpaxqs831goi9kQ=
 golang.org/x/sys v0.37.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.org/x/text v0.30.0 h1:yznKA/E9zq54KzlzBEAWn1NXSQ8DIp/NYMy88xJjl4k=
diff --git a/stats/opencensus/go.mod b/stats/opencensus/go.mod
index 280fda54ff16..9422581971c3 100644
--- a/stats/opencensus/go.mod
+++ b/stats/opencensus/go.mod
@@ -10,7 +10,7 @@ require (
 
 require (
 	github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 // indirect
-	golang.org/x/net v0.46.0 // indirect
+	golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 // indirect
 	golang.org/x/sys v0.37.0 // indirect
 	golang.org/x/text v0.30.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20251014184007-4626949a642f // indirect
diff --git a/stats/opencensus/go.sum b/stats/opencensus/go.sum
index e292d4e53479..c121cb6bdf5e 100644
--- a/stats/opencensus/go.sum
+++ b/stats/opencensus/go.sum
@@ -3750,8 +3750,8 @@ golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8=
 golang.org/x/net v0.43.0/go.mod h1:vhO1fvI4dGsIjh73sWfUVjj3N7CA9WkKJNQm2svM6Jg=
 golang.org/x/net v0.44.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
 golang.org/x/net v0.45.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
-golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
-golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20191202225959-858c2ad4c8b6/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=

From 6820fee324dd5aa251a586b3ef4c4f00d43d584e Mon Sep 17 00:00:00 2001
From: Arjan Bal <arjansbal@google.com>
Date: Tue, 21 Oct 2025 14:14:07 +0530
Subject: [PATCH 06/11] fix error codes and interface types

---
 internal/transport/http_util.go      | 14 +++++++-------
 internal/transport/http_util_test.go | 27 ++++++++++++++-------------
 2 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/internal/transport/http_util.go b/internal/transport/http_util.go
index f4159690a203..ba81f7ab4509 100644
--- a/internal/transport/http_util.go
+++ b/internal/transport/http_util.go
@@ -300,11 +300,11 @@ type bufWriter struct {
 	buf       []byte
 	offset    int
 	batchSize int
-	conn      io.ReadWriter
+	conn      io.Writer
 	err       error
 }
 
-func newBufWriter(conn io.ReadWriter, batchSize int, pool *sync.Pool) *bufWriter {
+func newBufWriter(conn io.Writer, batchSize int, pool *sync.Pool) *bufWriter {
 	w := &bufWriter{
 		batchSize: batchSize,
 		conn:      conn,
@@ -466,7 +466,7 @@ func (f *framer) readDataFrame(fh http2.FrameHeader) (err error) {
 		// field is 0x0, the recipient MUST respond with a
 		// connection error (Section 5.4.1) of type
 		// PROTOCOL_ERROR.
-		return fmt.Errorf("DATA frame with stream ID 0")
+		return http2.ConnectionError(http2.ErrCodeProtocol)
 	}
 	// Converting a *[]byte to a mem.BufferSlice incurs a heap allocation. This
 	// conversion is performed by mem.NewBuffer. To avoid the extra allocation
@@ -500,15 +500,15 @@ func (f *framer) readDataFrame(fh http2.FrameHeader) (err error) {
 		}
 		padSize := buf[0]
 		buf = buf[:len(buf)-1]
-		if _, err := io.ReadFull(f.reader, buf); err != nil {
-			return err
-		}
 		if int(padSize) > len(buf) {
 			// If the length of the padding is greater than the
 			// length of the frame payload, the recipient MUST
 			// treat this as a connection error.
 			// Filed: https://github.com/http2/http2-spec/issues/610
-			return fmt.Errorf("pad size larger than data payload")
+			return http2.ConnectionError(http2.ErrCodeProtocol)
+		}
+		if _, err := io.ReadFull(f.reader, buf); err != nil {
+			return err
 		}
 		buf = buf[:len(buf)-int(padSize)]
 	} else if _, err := io.ReadFull(f.reader, buf); err != nil {
diff --git a/internal/transport/http_util_test.go b/internal/transport/http_util_test.go
index 69e631d8b215..901a7253398f 100644
--- a/internal/transport/http_util_test.go
+++ b/internal/transport/http_util_test.go
@@ -29,6 +29,7 @@ import (
 	"testing"
 	"time"
 
+	"golang.org/x/net/http2"
 	"google.golang.org/grpc/mem"
 )
 
@@ -301,39 +302,39 @@ func BenchmarkEncodeGrpcMessage(b *testing.B) {
 
 func (s) TestFrame_ReadDataFrame(t *testing.T) {
 	tests := []struct {
-		name     string
-		w        func(fr *framer) error
-		wantData []byte
-		wantErr  bool
+		name        string
+		writeFrames func(fr *framer) error
+		wantData    []byte
+		wantErr     error
 	}{
 		{
 			name: "good_padded",
-			w: func(fr *framer) error {
+			writeFrames: func(fr *framer) error {
 				return fr.fr.WriteDataPadded(1, false, []byte("foo"), []byte{0, 0})
 			},
 			wantData: []byte("foo"),
 		},
 		{
 			name: "good_unpadded",
-			w: func(fr *framer) error {
+			writeFrames: func(fr *framer) error {
 				return fr.fr.WriteData(1, false, []byte("foo"))
 			},
 			wantData: []byte("foo"),
 		},
 		{
 			name: "padded_zero_data_some_padding",
-			w: func(fr *framer) error {
+			writeFrames: func(fr *framer) error {
 				return fr.fr.WriteDataPadded(1, false, []byte{}, []byte{0, 0})
 			},
 			wantData: []byte{},
 		},
 		{
 			name: "stream_id_0",
-			w: func(fr *framer) error {
+			writeFrames: func(fr *framer) error {
 				fr.fr.AllowIllegalWrites = true
 				return fr.fr.WriteData(0, false, []byte("foo"))
 			},
-			wantErr: true,
+			wantErr: http2.ConnectionError(http2.ErrCodeProtocol),
 		},
 	}
 
@@ -341,7 +342,7 @@ func (s) TestFrame_ReadDataFrame(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			fr, _ := testFramer()
 			// Write the frame using the provided function.
-			writeErr := tt.w(fr)
+			writeErr := tt.writeFrames(fr)
 			if writeErr != nil {
 				t.Fatalf("tt.w() returned unexpected error: %v", writeErr)
 			}
@@ -349,10 +350,10 @@ func (s) TestFrame_ReadDataFrame(t *testing.T) {
 
 			// Read the frame back.
 			f, err := fr.readFrame()
-			if gotErr := err != nil; gotErr != tt.wantErr {
-				t.Fatalf("ReadFrame() err = %v; want %t", err, tt.wantErr)
+			if err != tt.wantErr {
+				t.Fatalf("ReadFrame() err = %v; want %v", err, tt.wantErr)
 			}
-			if tt.wantErr {
+			if tt.wantErr != nil {
 				return
 			}
 

From 00586ba7f105bc2ed12f4302c95cc333bc3aea47 Mon Sep 17 00:00:00 2001
From: Arjan Bal <arjansbal@google.com>
Date: Tue, 21 Oct 2025 15:09:55 +0530
Subject: [PATCH 07/11] Improve testing of error cases

---
 internal/transport/http2_client.go   |   2 +-
 internal/transport/http_util.go      |  22 ++++-
 internal/transport/http_util_test.go | 126 ++++++++++++++++++---------
 3 files changed, 105 insertions(+), 45 deletions(-)

diff --git a/internal/transport/http2_client.go b/internal/transport/http2_client.go
index cff2c616ad21..6394697032fa 100644
--- a/internal/transport/http2_client.go
+++ b/internal/transport/http2_client.go
@@ -1676,7 +1676,7 @@ func (t *http2Client) reader(errCh chan<- error) {
 				if s != nil {
 					// use error detail to provide better err message
 					code := http2ErrConvTab[se.Code]
-					errorDetail := t.framer.fr.ErrorDetail()
+					errorDetail := t.framer.errorDetail()
 					var msg string
 					if errorDetail != nil {
 						msg = errorDetail.Error()
diff --git a/internal/transport/http_util.go b/internal/transport/http_util.go
index ba81f7ab4509..e4257b5f5c3e 100644
--- a/internal/transport/http_util.go
+++ b/internal/transport/http_util.go
@@ -404,6 +404,7 @@ type framer struct {
 	// Cached data frame to avoid heap allocations.
 	dataFrame parsedDataFrame
 	pool      mem.BufferPool
+	errDetail error
 }
 
 var writeBufferPoolMap = make(map[int]*sync.Pool)
@@ -446,8 +447,10 @@ func newFramer(conn io.ReadWriter, writeBufferSize, readBufferSize int, sharedWr
 // readFrame reads a single frame. The returned Frame is only valid
 // until the next call to readFrame.
 func (f *framer) readFrame() (any, error) {
+	f.errDetail = nil
 	fh, err := f.fr.ReadFrameHeader()
 	if err != nil {
+		f.errDetail = f.fr.ErrorDetail()
 		return nil, err
 	}
 	// Read the data frame directly from the underlying io.Reader to avoid
@@ -456,7 +459,22 @@ func (f *framer) readFrame() (any, error) {
 		err = f.readDataFrame(fh)
 		return &f.dataFrame, err
 	}
-	return f.fr.ReadFrameForHeader(fh)
+	fr, err := f.fr.ReadFrameForHeader(fh)
+	if err != nil {
+		f.errDetail = f.fr.ErrorDetail()
+		return nil, err
+	}
+	return fr, err
+}
+
+// errorDetail returns a more detailed error of the last error
+// returned by framer.readFrame. For instance, if readFrame
+// returns a StreamError with code PROTOCOL_ERROR, errorDetail
+// will say exactly what was invalid. errorDetail is not guaranteed
+// to return a non-nil value.
+// errorDetail is reset after the next call to readFrame.
+func (f *framer) errorDetail() error {
+	return f.errDetail
 }
 
 func (f *framer) readDataFrame(fh http2.FrameHeader) (err error) {
@@ -466,6 +484,7 @@ func (f *framer) readDataFrame(fh http2.FrameHeader) (err error) {
 		// field is 0x0, the recipient MUST respond with a
 		// connection error (Section 5.4.1) of type
 		// PROTOCOL_ERROR.
+		f.errDetail = errors.New("DATA frame with stream ID 0")
 		return http2.ConnectionError(http2.ErrCodeProtocol)
 	}
 	// Converting a *[]byte to a mem.BufferSlice incurs a heap allocation. This
@@ -505,6 +524,7 @@ func (f *framer) readDataFrame(fh http2.FrameHeader) (err error) {
 			// length of the frame payload, the recipient MUST
 			// treat this as a connection error.
 			// Filed: https://github.com/http2/http2-spec/issues/610
+			f.errDetail = errors.New("pad size larger than data payload")
 			return http2.ConnectionError(http2.ErrCodeProtocol)
 		}
 		if _, err := io.ReadFull(f.reader, buf); err != nil {
diff --git a/internal/transport/http_util_test.go b/internal/transport/http_util_test.go
index 901a7253398f..bda6d777a001 100644
--- a/internal/transport/http_util_test.go
+++ b/internal/transport/http_util_test.go
@@ -26,6 +26,7 @@ import (
 	"math"
 	"net"
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 
@@ -300,76 +301,115 @@ func BenchmarkEncodeGrpcMessage(b *testing.B) {
 	}
 }
 
-func (s) TestFrame_ReadDataFrame(t *testing.T) {
+func buildDataFrame(h http2.FrameHeader, payload []byte) []byte {
+	buf := new(bytes.Buffer)
+	buf.Write([]byte{
+		byte(h.Length >> 16),
+		byte(h.Length >> 8),
+		byte(h.Length),
+		byte(h.Type),
+		byte(h.Flags),
+		byte(h.StreamID >> 24),
+		byte(h.StreamID >> 16),
+		byte(h.StreamID >> 8),
+		byte(h.StreamID),
+	})
+	buf.Write(payload)
+	return buf.Bytes()
+}
+
+func (s) TestFramer_ParseDataFrame(t *testing.T) {
 	tests := []struct {
-		name        string
-		writeFrames func(fr *framer) error
-		wantData    []byte
-		wantErr     error
+		name                string
+		wire                []byte // from frame header onward
+		wantData            []byte
+		wantErr             error
+		wantErrDetailSubstr string
 	}{
 		{
 			name: "good_padded",
-			writeFrames: func(fr *framer) error {
-				return fr.fr.WriteDataPadded(1, false, []byte("foo"), []byte{0, 0})
-			},
+			wire: buildDataFrame(http2.FrameHeader{
+				Type: http2.FrameData, Length: 6, StreamID: 1, Flags: http2.FlagDataPadded,
+			}, []byte{
+				2,             // pad length
+				'f', 'o', 'o', // data
+				0, 0, // padding
+			}),
 			wantData: []byte("foo"),
 		},
 		{
 			name: "good_unpadded",
-			writeFrames: func(fr *framer) error {
-				return fr.fr.WriteData(1, false, []byte("foo"))
-			},
+			wire: buildDataFrame(http2.FrameHeader{
+				Type: http2.FrameData, Length: 3, StreamID: 1, Flags: 0,
+			}, []byte("foo")),
 			wantData: []byte("foo"),
 		},
+		{
+			name: "stream_id_0",
+			wire: buildDataFrame(http2.FrameHeader{
+				Type: http2.FrameData, Length: 1, StreamID: 0, Flags: 0,
+			}, []byte{0}),
+			wantErr:             http2.ConnectionError(http2.ErrCodeProtocol),
+			wantErrDetailSubstr: "DATA frame with stream ID 0",
+		},
+		{
+			name: "pad_size_bigger_than_payload",
+			wire: buildDataFrame(http2.FrameHeader{
+				Type: http2.FrameData, Length: 4, StreamID: 1, Flags: http2.FlagDataPadded,
+			}, []byte{
+				4,        // pad length of 4
+				'f', 'o', // data 'fo' is 2 bytes
+				0, // padding 0 is 1 byte.
+			}), // pad length 4 but only 3 bytes for data+padding available in payload after pad length byte
+			wantErr:             http2.ConnectionError(http2.ErrCodeProtocol),
+			wantErrDetailSubstr: "pad size larger than data payload",
+		},
 		{
 			name: "padded_zero_data_some_padding",
-			writeFrames: func(fr *framer) error {
-				return fr.fr.WriteDataPadded(1, false, []byte{}, []byte{0, 0})
-			},
+			wire: buildDataFrame(http2.FrameHeader{
+				Type: http2.FrameData, Length: 3, StreamID: 1, Flags: http2.FlagDataPadded,
+			}, []byte{
+				2,    // pad length 2
+				0, 0, // padding
+			}),
 			wantData: []byte{},
 		},
 		{
-			name: "stream_id_0",
-			writeFrames: func(fr *framer) error {
-				fr.fr.AllowIllegalWrites = true
-				return fr.fr.WriteData(0, false, []byte("foo"))
-			},
-			wantErr: http2.ConnectionError(http2.ErrCodeProtocol),
+			name: "padded_short_payload_reading_pad_flag",
+			wire: buildDataFrame(http2.FrameHeader{
+				Type: http2.FrameData, Length: 0, StreamID: 1, Flags: http2.FlagDataPadded,
+			}, []byte{}),
+			wantErr: io.ErrUnexpectedEOF,
 		},
 	}
 
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			fr, _ := testFramer()
-			// Write the frame using the provided function.
-			writeErr := tt.writeFrames(fr)
-			if writeErr != nil {
-				t.Fatalf("tt.w() returned unexpected error: %v", writeErr)
-			}
-			fr.writer.Flush()
-
-			// Read the frame back.
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			fr := newFramer(bytes.NewBuffer(tc.wire), defaultWriteBufSize, defaultReadBufSize, false, defaultClientMaxHeaderListSize, mem.DefaultBufferPool())
 			f, err := fr.readFrame()
-			if err != tt.wantErr {
-				t.Fatalf("ReadFrame() err = %v; want %v", err, tt.wantErr)
+
+			if err != tc.wantErr {
+				t.Fatalf("readFrame() returned unexpected error: %v, want %v", err, tc.wantErr)
 			}
-			if tt.wantErr != nil {
-				return
+			gotErrDetailStr := ""
+			if fr.errDetail != nil {
+				gotErrDetailStr = fr.errDetail.Error()
+			}
+			if !strings.Contains(gotErrDetailStr, tc.wantErrDetailSubstr) {
+				t.Fatalf("errorDetail() returned unexpected error string: %q, want substring %q", gotErrDetailStr, tc.wantErrDetailSubstr)
 			}
 
+			if tc.wantErr != nil {
+				return
+			}
 			df, ok := f.(*parsedDataFrame)
 			if !ok {
-				t.Fatalf("ReadFrame() returned %T, want *parsedDataFrame", f)
+				t.Fatalf("readFrame() returned %T, want *parsedDataFrame", f)
 			}
-			if gotData := df.data.ReadOnlyData(); !bytes.Equal(gotData, tt.wantData) {
-				t.Fatalf("parsedDataFrame.Data() = %q, want %q", gotData, tt.wantData)
+			if gotData := df.data.ReadOnlyData(); !bytes.Equal(gotData, tc.wantData) {
+				t.Fatalf("parsedDataFrame.Data() = %q, want %q", gotData, tc.wantData)
 			}
 			df.data.Free()
 		})
 	}
 }
-
-func testFramer() (*framer, *bytes.Buffer) {
-	buf := new(bytes.Buffer)
-	return newFramer(buf, defaultWriteBufSize, defaultReadBufSize, false, defaultClientMaxHeaderListSize, mem.DefaultBufferPool()), buf
-}

From 8ef2d03f78c04c7cdd1ac3018126b5858e028ae3 Mon Sep 17 00:00:00 2001
From: Arjan Bal <arjansbal@google.com>
Date: Tue, 28 Oct 2025 21:26:28 +0530
Subject: [PATCH 08/11] doc comments

---
 internal/transport/http_util.go | 9 ++++-----
 mem/buffer_pool.go              | 3 +++
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/internal/transport/http_util.go b/internal/transport/http_util.go
index e4257b5f5c3e..76e6f21bc2f1 100644
--- a/internal/transport/http_util.go
+++ b/internal/transport/http_util.go
@@ -398,11 +398,10 @@ func (df *parsedDataFrame) StreamEnded() bool {
 }
 
 type framer struct {
-	writer *bufWriter
-	fr     *http2.Framer
-	reader io.Reader
-	// Cached data frame to avoid heap allocations.
-	dataFrame parsedDataFrame
+	writer    *bufWriter
+	fr        *http2.Framer
+	reader    io.Reader
+	dataFrame parsedDataFrame // Cached data frame to avoid heap allocations.
 	pool      mem.BufferPool
 	errDetail error
 }
diff --git a/mem/buffer_pool.go b/mem/buffer_pool.go
index c37c58c0233e..cd7f88615ade 100644
--- a/mem/buffer_pool.go
+++ b/mem/buffer_pool.go
@@ -32,6 +32,9 @@ type BufferPool interface {
 	Get(length int) *[]byte
 
 	// Put returns a buffer to the pool.
+	//
+	// The returned pointer must hold a prefix of the buffer obtained via [Get]
+	// to ensure the buffer's entire capacity can be re-used.
 	Put(*[]byte)
 }
 

From a121b1550cc1df610a2325ebc474dd6b5343fd2e Mon Sep 17 00:00:00 2001
From: Arjan Singh Bal <46515553+arjan-bal@users.noreply.github.com>
Date: Fri, 31 Oct 2025 11:13:43 +0530
Subject: [PATCH 09/11] Apply suggestions from code review

Co-authored-by: Doug Fawley <dfawley@google.com>
---
 mem/buffer_pool.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mem/buffer_pool.go b/mem/buffer_pool.go
index cd7f88615ade..939a81870f8f 100644
--- a/mem/buffer_pool.go
+++ b/mem/buffer_pool.go
@@ -33,7 +33,7 @@ type BufferPool interface {
 
 	// Put returns a buffer to the pool.
 	//
-	// The returned pointer must hold a prefix of the buffer obtained via [Get]
+	// The provided pointer must hold a prefix of the buffer obtained via [Get]
 	// to ensure the buffer's entire capacity can be re-used.
 	Put(*[]byte)
 }

From e7b6d3584d9594f80a407062e8624e22f8b68200 Mon Sep 17 00:00:00 2001
From: Arjan Bal <arjansbal@google.com>
Date: Fri, 31 Oct 2025 11:16:59 +0530
Subject: [PATCH 10/11] Fix comment

---
 internal/transport/http_util.go | 5 ++---
 mem/buffer_pool.go              | 4 ++--
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/internal/transport/http_util.go b/internal/transport/http_util.go
index 76e6f21bc2f1..0ba6c7e79941 100644
--- a/internal/transport/http_util.go
+++ b/internal/transport/http_util.go
@@ -486,10 +486,9 @@ func (f *framer) readDataFrame(fh http2.FrameHeader) (err error) {
 		f.errDetail = errors.New("DATA frame with stream ID 0")
 		return http2.ConnectionError(http2.ErrCodeProtocol)
 	}
-	// Converting a *[]byte to a mem.BufferSlice incurs a heap allocation. This
+	// Converting a *[]byte to a mem.SliceBuffer incurs a heap allocation. This
 	// conversion is performed by mem.NewBuffer. To avoid the extra allocation
-	// a []byte is allocated directly if required and casted to a
-	// mem.BufferSlice.
+	// a []byte is allocated directly if required and cast to a mem.SliceBuffer.
 	var buf []byte
 	// poolHandle is the pointer returned by the buffer pool (if it's used.).
 	var poolHandle *[]byte
diff --git a/mem/buffer_pool.go b/mem/buffer_pool.go
index 939a81870f8f..d455033ec968 100644
--- a/mem/buffer_pool.go
+++ b/mem/buffer_pool.go
@@ -33,8 +33,8 @@ type BufferPool interface {
 
 	// Put returns a buffer to the pool.
 	//
-	// The provided pointer must hold a prefix of the buffer obtained via [Get]
-	// to ensure the buffer's entire capacity can be re-used.
+	// The provided pointer must hold a prefix of the buffer obtained via
+	// BufferPool.Get to ensure the buffer's entire capacity can be re-used.
 	Put(*[]byte)
 }
 

From f0e9b133dc1cb06ac41aee3e4a05ac551752c6bc Mon Sep 17 00:00:00 2001
From: Arjan Bal <arjansbal@google.com>
Date: Fri, 31 Oct 2025 11:49:15 +0530
Subject: [PATCH 11/11] Fix merge conflicts

---
 examples/go.sum              | 1 +
 interop/observability/go.sum | 1 +
 2 files changed, 2 insertions(+)

diff --git a/examples/go.sum b/examples/go.sum
index 8855d98dd72e..0235a2850417 100644
--- a/examples/go.sum
+++ b/examples/go.sum
@@ -4126,6 +4126,7 @@ golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8=
 golang.org/x/net v0.43.0/go.mod h1:vhO1fvI4dGsIjh73sWfUVjj3N7CA9WkKJNQm2svM6Jg=
 golang.org/x/net v0.44.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
 golang.org/x/net v0.45.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
+golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
 golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
diff --git a/interop/observability/go.sum b/interop/observability/go.sum
index c4bf65abb5bf..4782e3921844 100644
--- a/interop/observability/go.sum
+++ b/interop/observability/go.sum
@@ -4096,6 +4096,7 @@ golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8=
 golang.org/x/net v0.43.0/go.mod h1:vhO1fvI4dGsIjh73sWfUVjj3N7CA9WkKJNQm2svM6Jg=
 golang.org/x/net v0.44.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
 golang.org/x/net v0.45.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
+golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
 golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=