webp: fix panic in case of invalid chunkID

At the time of decoding webp file, if chunkID is not one of {'ALPH', 'VP8', 'VP8L', 'VP8X'} return errInvalidFormat Fixes golang/go#10384 Change-Id: I167909b5ddef174d161f806297a08fac6aabcf19 Reviewed-on: https://go-review.googlesource.com/9839 Reviewed-by: Nigel Tao <[email protected]>
balloontmz6 · Feb 10, 2022 · 034113b · 034113b
1 parent 8409dd7
commit 034113b
Show file tree

Hide file tree

Showing 2 changed files with 6 additions and 4 deletions.
diff --git a/riff/riff.go b/riff/riff.go
@@ -136,11 +136,10 @@ func (z *Reader) Next() (chunkID FourCC, chunkLen uint32, chunkData io.Reader, e
 		return FourCC{}, 0, nil, z.err
 	}
 	chunkID = FourCC{z.buf[0], z.buf[1], z.buf[2], z.buf[3]}
-	chunkLen = u32(z.buf[4:])
-	z.chunkLen = chunkLen
-	z.padded = chunkLen&1 == 1
+	z.chunkLen = u32(z.buf[4:])
+	z.padded = z.chunkLen&1 == 1
 	z.chunkReader = &chunkReader{z}
-	return chunkID, chunkLen, z.chunkReader, nil
+	return chunkID, z.chunkLen, z.chunkReader, nil
 }
 
 type chunkReader struct {

diff --git a/webp/decode.go b/webp/decode.go
@@ -144,6 +144,9 @@ func decode(r io.Reader, configOnly bool) (image.Image, image.Config, error) {
 				}, nil
 			}
 			wantAlpha = true
+
+		default:
+			return nil, image.Config{}, errInvalidFormat
 		}
 	}
 }
-Original file line number
+Diff line change
@@ Expand Up @@
     				}, nil
     			}
     			wantAlpha = true
+    		default:
+    			return nil, image.Config{}, errInvalidFormat
     		}
     	}
     }
@@ Expand Down @@