image/jpeg: reject multiple Start-Of-Frame markers.

Fixes #10389

Change-Id: Id1c687122751f9317041d9e425d03b267a26c6de
Reviewed-on: https://go-review.googlesource.com/8681
Reviewed-by: Rob Pike <r@golang.org>

diff --git a/src/image/jpeg/reader.go b/src/image/jpeg/reader.go
index 6a8647204627c5a38d5dcafcfff0acee73ff6643..2c3c2f72f8dbd6af93a15a782f75ed1f598adbb5 100644 (file)
--- a/src/image/jpeg/reader.go
+++ b/src/image/jpeg/reader.go
@@ -298,6 +298,9 @@ func (d *decoder) ignore(n int) error {
 
 // Specified in section B.2.2.
 func (d *decoder) processSOF(n int) error {
+       if d.nComp != 0 {
+               return FormatError("multiple SOF markers")
+       }
        switch n {
        case 6 + 3*1: // Grayscale image.
                d.nComp = 1