1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
From 9d339f1d0f53c4116a7cb4acfa895f31a07212ee Mon Sep 17 00:00:00 2001
From: Damien Neil <dneil@google.com>
Date: Fri, 2 Sep 2022 20:45:18 -0700
Subject: [PATCH] archive/tar: limit size of headers
Set a 1MiB limit on special file blocks (PAX headers, GNU long names,
GNU link names), to avoid reading arbitrarily large amounts of data
into memory.
Thanks to Adam Korczynski (ADA Logics) and OSS-Fuzz for reporting
this issue.
Fixes CVE-2022-2879
Updates #54853
Fixes #55926
Change-Id: I85136d6ff1e0af101a112190e027987ab4335680
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1565555
Reviewed-by: Tatiana Bradley <tatianabradley@google.com>
Run-TryBot: Roland Shoemaker <bracewell@google.com>
Reviewed-by: Roland Shoemaker <bracewell@google.com>
(cherry picked from commit 6ee768cef6b82adf7a90dcf367a1699ef694f3b2)
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1591053
Reviewed-by: Julie Qiu <julieqiu@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/438498
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Carlos Amedee <carlos@golang.org>
Upstream-Status: Backport [https://github.com/golang/go/commit/0a723816cd2]
CVE: CVE-2022-2879
Signed-off-by: Sunil Kumar <sukumar@mvista.com>
---
src/archive/tar/format.go | 4 ++++
src/archive/tar/reader.go | 14 ++++++++++++--
src/archive/tar/writer.go | 3 +++
3 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/src/archive/tar/format.go b/src/archive/tar/format.go
index cfe24a5..6642364 100644
--- a/src/archive/tar/format.go
+++ b/src/archive/tar/format.go
@@ -143,6 +143,10 @@ const (
blockSize = 512 // Size of each block in a tar stream
nameSize = 100 // Max length of the name field in USTAR format
prefixSize = 155 // Max length of the prefix field in USTAR format
+
+ // Max length of a special file (PAX header, GNU long name or link).
+ // This matches the limit used by libarchive.
+ maxSpecialFileSize = 1 << 20
)
// blockPadding computes the number of bytes needed to pad offset up to the
diff --git a/src/archive/tar/reader.go b/src/archive/tar/reader.go
index 4f9135b..e996595 100644
--- a/src/archive/tar/reader.go
+++ b/src/archive/tar/reader.go
@@ -104,7 +104,7 @@ func (tr *Reader) next() (*Header, error) {
continue // This is a meta header affecting the next header
case TypeGNULongName, TypeGNULongLink:
format.mayOnlyBe(FormatGNU)
- realname, err := ioutil.ReadAll(tr)
+ realname, err := readSpecialFile(tr)
if err != nil {
return nil, err
}
@@ -294,7 +294,7 @@ func mergePAX(hdr *Header, paxHdrs map[string]string) (err error) {
// parsePAX parses PAX headers.
// If an extended header (type 'x') is invalid, ErrHeader is returned
func parsePAX(r io.Reader) (map[string]string, error) {
- buf, err := ioutil.ReadAll(r)
+ buf, err := readSpecialFile(r)
if err != nil {
return nil, err
}
@@ -827,6 +827,16 @@ func tryReadFull(r io.Reader, b []byte) (n int, err error) {
return n, err
}
+// readSpecialFile is like ioutil.ReadAll except it returns
+// ErrFieldTooLong if more than maxSpecialFileSize is read.
+func readSpecialFile(r io.Reader) ([]byte, error) {
+ buf, err := ioutil.ReadAll(io.LimitReader(r, maxSpecialFileSize+1))
+ if len(buf) > maxSpecialFileSize {
+ return nil, ErrFieldTooLong
+ }
+ return buf, err
+}
+
// discard skips n bytes in r, reporting an error if unable to do so.
func discard(r io.Reader, n int64) error {
// If possible, Seek to the last byte before the end of the data section.
diff --git a/src/archive/tar/writer.go b/src/archive/tar/writer.go
index e80498d..893eac0 100644
--- a/src/archive/tar/writer.go
+++ b/src/archive/tar/writer.go
@@ -199,6 +199,9 @@ func (tw *Writer) writePAXHeader(hdr *Header, paxHdrs map[string]string) error {
flag = TypeXHeader
}
data := buf.String()
+ if len(data) > maxSpecialFileSize {
+ return ErrFieldTooLong
+ }
if err := tw.writeRawFile(name, data, flag, FormatPAX); err != nil || isGlobal {
return err // Global headers return here
}
--
2.7.4
|
