From: Brad Fitzpatrick <bradfitz@golang.org>
Date: Mon, 6 Jan 2014 18:43:56 +0000 (-0800)
Subject: archive/zip: fix bug reading zip64 files
X-Git-Tag: go1.3beta1~1048
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=02a15e716519b71aca6b74a0a388b30e83892e08;p=gostls13.git

archive/zip: fix bug reading zip64 files

ZIP64 Extra records are variably sized, but we weren't capping
our reading of the extra fields at its previously-declared
size.

No test because I don't know how to easily create such files
and don't feel like manually construction one.  But all
existing tests pass, and this is "obviously correct" (queue
laughter).

Fixes #7069

R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/48150043
---

diff --git a/src/pkg/archive/zip/reader.go b/src/pkg/archive/zip/reader.go
index 116737337f..80ee03006f 100644
--- a/src/pkg/archive/zip/reader.go
+++ b/src/pkg/archive/zip/reader.go
@@ -253,7 +253,7 @@ func readDirectoryHeader(f *File, r io.Reader) error {
 			}
 			if tag == zip64ExtraId {
 				// update directory values from the zip64 extra block
-				eb := readBuf(b)
+				eb := readBuf(b[:size])
 				if len(eb) >= 8 {
 					f.UncompressedSize64 = eb.uint64()
 				}