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
|
From ede41d1e186ed2aba88a06e84cac839b770af3a1 Mon Sep 17 00:00:00 2001
From: Sebastian Pipping <sebastian@pipping.org>
Date: Wed, 26 Jan 2022 02:36:43 +0100
Subject: [PATCH 1/2] lib: Prevent integer overflow in doProlog
(CVE-2022-23990)
The change from "int nameLen" to "size_t nameLen"
addresses the overflow on "nameLen++" in code
"for (; name[nameLen++];)" right above the second
change in the patch.
---
expat/lib/xmlparse.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/expat/lib/xmlparse.c b/expat/lib/xmlparse.c
index 5ce31402..d1d17005 100644
--- a/expat/lib/xmlparse.c
+++ b/expat/lib/xmlparse.c
@@ -5372,7 +5372,7 @@ doProlog(XML_Parser parser, const ENCODING *enc, const char *s, const char *end,
if (dtd->in_eldecl) {
ELEMENT_TYPE *el;
const XML_Char *name;
- int nameLen;
+ size_t nameLen;
const char *nxt
= (quant == XML_CQUANT_NONE ? next : next - enc->minBytesPerChar);
int myindex = nextScaffoldPart(parser);
@@ -5388,7 +5388,13 @@ doProlog(XML_Parser parser, const ENCODING *enc, const char *s, const char *end,
nameLen = 0;
for (; name[nameLen++];)
;
- dtd->contentStringLen += nameLen;
+
+ /* Detect and prevent integer overflow */
+ if (nameLen > UINT_MAX - dtd->contentStringLen) {
+ return XML_ERROR_NO_MEMORY;
+ }
+
+ dtd->contentStringLen += (unsigned)nameLen;
if (parser->m_elementDeclHandler)
handleDefault = XML_FALSE;
}
From 6e3449594fb2f61c92fc561f51f82196fdd15d63 Mon Sep 17 00:00:00 2001
From: Sebastian Pipping <sebastian@pipping.org>
Date: Wed, 26 Jan 2022 02:51:39 +0100
Subject: [PATCH 2/2] Changes: Document CVE-2022-23990
---
expat/Changes | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/expat/Changes b/expat/Changes
index 5ff5da5e..ec1f7604 100644
--- a/expat/Changes
+++ b/expat/Changes
@@ -10,12 +10,18 @@ Release x.x.x xxx xxxxxxx xx xxxx
for when XML_CONTEXT_BYTES is defined to >0 (which is both
common and default).
Impact is denial of service or more.
+ #551 CVE-2022-23990 -- Fix unsigned integer overflow in function
+ doProlog triggered by large content in element type
+ declarations when there is an element declaration handler
+ present (from a prior call to XML_SetElementDeclHandler).
+ Impact is denial of service or more.
Bug fixes:
#544 #545 xmlwf: Fix a memory leak on output file opening error
Special thanks to:
hwt0415
+ Roland Illig
Samanta Navarro
and
Clang LeakSan and the Clang team
|
