From: Alexander Yastrebov <yastrebov.alex@gmail.com>
Date: Sat, 4 Feb 2023 14:52:55 +0000 (+0000)
Subject: image/jpeg: return io.ErrUnexpectedEOF on truncated data
X-Git-Tag: go1.21rc1~1491
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=f684f3dc434f9199ceee175c07d28e8b2b0f28dc;p=gostls13.git

image/jpeg: return io.ErrUnexpectedEOF on truncated data

Decoder calls fill from readFull, ignore and readByte and
readByte did not check returned io.EOF.

This change moves io.EOF translation inside fill.

name                 old speed      new speed      delta
DecodeBaseline-8     67.4MB/s ± 0%  67.3MB/s ± 0%  -0.20%  (p=0.000 n=16+19)
DecodeProgressive-8  43.7MB/s ± 0%  43.6MB/s ± 0%  -0.06%  (p=0.013 n=17+19)

Fixes #56724

Change-Id: Ia0d5cc561f3c2050e25ec3f2b5e6866c3b4941c7
GitHub-Last-Rev: 470154373bc1452dffc5293d9a840e972749a76d
GitHub-Pull-Request: golang/go#56863
Reviewed-on: https://go-review.googlesource.com/c/go/+/452335
Run-TryBot: Rob Pike <r@golang.org>
Reviewed-by: Nigel Tao <nigeltao@golang.org>
Reviewed-by: Nigel Tao (INACTIVE; USE @golang.org INSTEAD) <nigeltao@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
---

diff --git a/src/image/jpeg/huffman.go b/src/image/jpeg/huffman.go
index 95aaf71e2f..72444369ab 100644
--- a/src/image/jpeg/huffman.go
+++ b/src/image/jpeg/huffman.go
@@ -49,7 +49,7 @@ func (d *decoder) ensureNBits(n int32) error {
 	for {
 		c, err := d.readByteStuffedByte()
 		if err != nil {
-			if err == io.EOF {
+			if err == io.ErrUnexpectedEOF {
 				return errShortHuffmanData
 			}
 			return err
diff --git a/src/image/jpeg/reader.go b/src/image/jpeg/reader.go
index b34072396c..61f2b4020d 100644
--- a/src/image/jpeg/reader.go
+++ b/src/image/jpeg/reader.go
@@ -164,7 +164,10 @@ func (d *decoder) fill() error {
 	n, err := d.r.Read(d.bytes.buf[d.bytes.j:])
 	d.bytes.j += n
 	if n > 0 {
-		err = nil
+		return nil
+	}
+	if err == io.EOF {
+		err = io.ErrUnexpectedEOF
 	}
 	return err
 }
@@ -261,9 +264,6 @@ func (d *decoder) readFull(p []byte) error {
 			break
 		}
 		if err := d.fill(); err != nil {
-			if err == io.EOF {
-				err = io.ErrUnexpectedEOF
-			}
 			return err
 		}
 	}
@@ -291,9 +291,6 @@ func (d *decoder) ignore(n int) error {
 			break
 		}
 		if err := d.fill(); err != nil {
-			if err == io.EOF {
-				err = io.ErrUnexpectedEOF
-			}
 			return err
 		}
 	}
diff --git a/src/image/jpeg/reader_test.go b/src/image/jpeg/reader_test.go
index 02a2eb6509..cdac2dd756 100644
--- a/src/image/jpeg/reader_test.go
+++ b/src/image/jpeg/reader_test.go
@@ -490,6 +490,20 @@ func TestExtraneousData(t *testing.T) {
 	}
 }
 
+func TestIssue56724(t *testing.T) {
+	b, err := os.ReadFile("../testdata/video-001.jpeg")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	b = b[:24] // truncate image data
+
+	_, err = Decode(bytes.NewReader(b))
+	if err != io.ErrUnexpectedEOF {
+		t.Errorf("got: %v, want: %v", err, io.ErrUnexpectedEOF)
+	}
+}
+
 func benchmarkDecode(b *testing.B, filename string) {
 	data, err := os.ReadFile(filename)
 	if err != nil {