Fix CVE-2021-3516, CVE-2021-3517 and CVE-2021-3518

Fix CVE-2021-3516 (#1954227), CVE-2021-3517 (#1954234) and CVE-2021-3518
(#1954243).
This commit is contained in:
David King 2021-05-05 09:49:39 +01:00
parent aef32771cd
commit 68f382363e
4 changed files with 339 additions and 1 deletions

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@ -0,0 +1,31 @@
From 1358d157d0bd83be1dfe356a69213df9fac0b539 Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Wed, 21 Apr 2021 13:23:27 +0200
Subject: [PATCH] Fix use-after-free with `xmllint --html --push`
Call htmlCtxtUseOptions to make sure that names aren't stored in
dictionaries.
Note that this issue only affects xmllint using the HTML push parser.
Fixes #230.
---
xmllint.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/xmllint.c b/xmllint.c
index 6ca1bf54..dbef273a 100644
--- a/xmllint.c
+++ b/xmllint.c
@@ -2213,7 +2213,7 @@ static void parseAndPrintFile(char *filename, xmlParserCtxtPtr rectxt) {
if (res > 0) {
ctxt = htmlCreatePushParserCtxt(NULL, NULL,
chars, res, filename, XML_CHAR_ENCODING_NONE);
- xmlCtxtUseOptions(ctxt, options);
+ htmlCtxtUseOptions(ctxt, options);
while ((res = fread(chars, 1, pushsize, f)) > 0) {
htmlParseChunk(ctxt, chars, res, 0);
}
--
GitLab

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@ -0,0 +1,49 @@
From bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2 Mon Sep 17 00:00:00 2001
From: Joel Hockey <joel.hockey@gmail.com>
Date: Sun, 16 Aug 2020 17:19:35 -0700
Subject: [PATCH] Validate UTF8 in xmlEncodeEntities
Code is currently assuming UTF-8 without validating. Truncated UTF-8
input can cause out-of-bounds array access.
Adds further checks to partial fix in 50f06b3e.
Fixes #178
---
entities.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/entities.c b/entities.c
index 37b99a56..1a8f86f0 100644
--- a/entities.c
+++ b/entities.c
@@ -704,11 +704,25 @@ xmlEncodeEntitiesInternal(xmlDocPtr doc, const xmlChar *input, int attr) {
} else {
/*
* We assume we have UTF-8 input.
+ * It must match either:
+ * 110xxxxx 10xxxxxx
+ * 1110xxxx 10xxxxxx 10xxxxxx
+ * 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+ * That is:
+ * cur[0] is 11xxxxxx
+ * cur[1] is 10xxxxxx
+ * cur[2] is 10xxxxxx if cur[0] is 111xxxxx
+ * cur[3] is 10xxxxxx if cur[0] is 1111xxxx
+ * cur[0] is not 11111xxx
*/
char buf[11], *ptr;
int val = 0, l = 1;
- if (*cur < 0xC0) {
+ if (((cur[0] & 0xC0) != 0xC0) ||
+ ((cur[1] & 0xC0) != 0x80) ||
+ (((cur[0] & 0xE0) == 0xE0) && ((cur[2] & 0xC0) != 0x80)) ||
+ (((cur[0] & 0xF0) == 0xF0) && ((cur[3] & 0xC0) != 0x80)) ||
+ (((cur[0] & 0xF8) == 0xF8))) {
xmlEntitiesErr(XML_CHECK_NOT_UTF8,
"xmlEncodeEntities: input not UTF-8");
if (doc != NULL)
--
GitLab

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@ -0,0 +1,247 @@
From 752e5f71d7cea2ca5a7e7c0b8f72ed04ce654be4 Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Wed, 10 Jun 2020 16:34:52 +0200
Subject: [PATCH 1/2] Don't recurse into xi:include children in
xmlXIncludeDoProcess
Otherwise, nested xi:include nodes might result in a use-after-free
if XML_PARSE_NOXINCNODE is specified.
Found with libFuzzer and ASan.
---
result/XInclude/fallback3.xml | 8 ++++++++
result/XInclude/fallback3.xml.err | 0
result/XInclude/fallback3.xml.rdr | 25 +++++++++++++++++++++++++
result/XInclude/fallback4.xml | 10 ++++++++++
result/XInclude/fallback4.xml.err | 0
result/XInclude/fallback4.xml.rdr | 29 +++++++++++++++++++++++++++++
test/XInclude/docs/fallback3.xml | 9 +++++++++
test/XInclude/docs/fallback4.xml | 7 +++++++
xinclude.c | 24 ++++++++++--------------
9 files changed, 98 insertions(+), 14 deletions(-)
create mode 100644 result/XInclude/fallback3.xml
create mode 100644 result/XInclude/fallback3.xml.err
create mode 100644 result/XInclude/fallback3.xml.rdr
create mode 100644 result/XInclude/fallback4.xml
create mode 100644 result/XInclude/fallback4.xml.err
create mode 100644 result/XInclude/fallback4.xml.rdr
create mode 100644 test/XInclude/docs/fallback3.xml
create mode 100644 test/XInclude/docs/fallback4.xml
diff --git a/result/XInclude/fallback3.xml b/result/XInclude/fallback3.xml
new file mode 100644
index 00000000..b4235514
--- /dev/null
+++ b/result/XInclude/fallback3.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0"?>
+<a>
+ <doc xml:base="../ents/something.xml">
+<p>something</p>
+<p>really</p>
+<p>simple</p>
+</doc>
+</a>
diff --git a/result/XInclude/fallback3.xml.err b/result/XInclude/fallback3.xml.err
new file mode 100644
index 00000000..e69de29b
diff --git a/result/XInclude/fallback3.xml.rdr b/result/XInclude/fallback3.xml.rdr
new file mode 100644
index 00000000..aa2f1374
--- /dev/null
+++ b/result/XInclude/fallback3.xml.rdr
@@ -0,0 +1,25 @@
+0 1 a 0 0
+1 14 #text 0 1
+
+1 1 doc 0 0
+2 14 #text 0 1
+
+2 1 p 0 0
+3 3 #text 0 1 something
+2 15 p 0 0
+2 14 #text 0 1
+
+2 1 p 0 0
+3 3 #text 0 1 really
+2 15 p 0 0
+2 14 #text 0 1
+
+2 1 p 0 0
+3 3 #text 0 1 simple
+2 15 p 0 0
+2 14 #text 0 1
+
+1 15 doc 0 0
+1 14 #text 0 1
+
+0 15 a 0 0
diff --git a/result/XInclude/fallback4.xml b/result/XInclude/fallback4.xml
new file mode 100644
index 00000000..9883fd54
--- /dev/null
+++ b/result/XInclude/fallback4.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<a>
+
+ <doc xml:base="../ents/something.xml">
+<p>something</p>
+<p>really</p>
+<p>simple</p>
+</doc>
+
+</a>
diff --git a/result/XInclude/fallback4.xml.err b/result/XInclude/fallback4.xml.err
new file mode 100644
index 00000000..e69de29b
diff --git a/result/XInclude/fallback4.xml.rdr b/result/XInclude/fallback4.xml.rdr
new file mode 100644
index 00000000..628b9513
--- /dev/null
+++ b/result/XInclude/fallback4.xml.rdr
@@ -0,0 +1,29 @@
+0 1 a 0 0
+1 14 #text 0 1
+
+1 14 #text 0 1
+
+1 1 doc 0 0
+2 14 #text 0 1
+
+2 1 p 0 0
+3 3 #text 0 1 something
+2 15 p 0 0
+2 14 #text 0 1
+
+2 1 p 0 0
+3 3 #text 0 1 really
+2 15 p 0 0
+2 14 #text 0 1
+
+2 1 p 0 0
+3 3 #text 0 1 simple
+2 15 p 0 0
+2 14 #text 0 1
+
+1 15 doc 0 0
+1 14 #text 0 1
+
+1 14 #text 0 1
+
+0 15 a 0 0
diff --git a/test/XInclude/docs/fallback3.xml b/test/XInclude/docs/fallback3.xml
new file mode 100644
index 00000000..0c8b6c9e
--- /dev/null
+++ b/test/XInclude/docs/fallback3.xml
@@ -0,0 +1,9 @@
+<a>
+ <xi:include href="../ents/something.xml" xmlns:xi="http://www.w3.org/2001/XInclude">
+ <xi:fallback>
+ <xi:include href="c.xml">
+ <xi:fallback>There is no c.xml ... </xi:fallback>
+ </xi:include>
+ </xi:fallback>
+ </xi:include>
+</a>
diff --git a/test/XInclude/docs/fallback4.xml b/test/XInclude/docs/fallback4.xml
new file mode 100644
index 00000000..b500a635
--- /dev/null
+++ b/test/XInclude/docs/fallback4.xml
@@ -0,0 +1,7 @@
+<a>
+ <xi:include href="c.xml" xmlns:xi="http://www.w3.org/2001/XInclude">
+ <xi:fallback>
+ <xi:include href="../ents/something.xml"/>
+ </xi:fallback>
+ </xi:include>
+</a>
diff --git a/xinclude.c b/xinclude.c
index ba850fa5..f260c1a7 100644
--- a/xinclude.c
+++ b/xinclude.c
@@ -2392,21 +2392,19 @@ xmlXIncludeDoProcess(xmlXIncludeCtxtPtr ctxt, xmlDocPtr doc, xmlNodePtr tree) {
* First phase: lookup the elements in the document
*/
cur = tree;
- if (xmlXIncludeTestNode(ctxt, cur) == 1)
- xmlXIncludePreProcessNode(ctxt, cur);
while ((cur != NULL) && (cur != tree->parent)) {
/* TODO: need to work on entities -> stack */
- if ((cur->children != NULL) &&
- (cur->children->type != XML_ENTITY_DECL) &&
- (cur->children->type != XML_XINCLUDE_START) &&
- (cur->children->type != XML_XINCLUDE_END)) {
- cur = cur->children;
- if (xmlXIncludeTestNode(ctxt, cur))
- xmlXIncludePreProcessNode(ctxt, cur);
- } else if (cur->next != NULL) {
+ if (xmlXIncludeTestNode(ctxt, cur) == 1) {
+ xmlXIncludePreProcessNode(ctxt, cur);
+ } else if ((cur->children != NULL) &&
+ (cur->children->type != XML_ENTITY_DECL) &&
+ (cur->children->type != XML_XINCLUDE_START) &&
+ (cur->children->type != XML_XINCLUDE_END)) {
+ cur = cur->children;
+ continue;
+ }
+ if (cur->next != NULL) {
cur = cur->next;
- if (xmlXIncludeTestNode(ctxt, cur))
- xmlXIncludePreProcessNode(ctxt, cur);
} else {
if (cur == tree)
break;
@@ -2416,8 +2414,6 @@ xmlXIncludeDoProcess(xmlXIncludeCtxtPtr ctxt, xmlDocPtr doc, xmlNodePtr tree) {
break; /* do */
if (cur->next != NULL) {
cur = cur->next;
- if (xmlXIncludeTestNode(ctxt, cur))
- xmlXIncludePreProcessNode(ctxt, cur);
break; /* do */
}
} while (cur != NULL);
--
2.31.1
From 49cc4182543dba73216add4021994a81678763bd Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Thu, 22 Apr 2021 19:26:28 +0200
Subject: [PATCH 2/2] Fix user-after-free with `xmllint --xinclude --dropdtd`
The --dropdtd option can leave dangling pointers in entity reference
nodes. Make sure to skip these nodes when processing XIncludes.
This also avoids scanning entity declarations and even modifying
them inadvertently during XInclude processing.
Move from a block list to an allow list approach to avoid descending
into other node types that can't contain elements.
Fixes #237.
---
xinclude.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/xinclude.c b/xinclude.c
index f260c1a7..d7648529 100644
--- a/xinclude.c
+++ b/xinclude.c
@@ -2397,9 +2397,8 @@ xmlXIncludeDoProcess(xmlXIncludeCtxtPtr ctxt, xmlDocPtr doc, xmlNodePtr tree) {
if (xmlXIncludeTestNode(ctxt, cur) == 1) {
xmlXIncludePreProcessNode(ctxt, cur);
} else if ((cur->children != NULL) &&
- (cur->children->type != XML_ENTITY_DECL) &&
- (cur->children->type != XML_XINCLUDE_START) &&
- (cur->children->type != XML_XINCLUDE_END)) {
+ ((cur->type == XML_DOCUMENT_NODE) ||
+ (cur->type == XML_ELEMENT_NODE))) {
cur = cur->children;
continue;
}
--
2.31.1

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@ -1,6 +1,6 @@
Name: libxml2
Version: 2.9.10
Release: 10%{?dist}
Release: 11%{?dist}
Summary: Library providing XML and HTML support
License: MIT
@ -22,6 +22,12 @@ Patch6: libxml2-2.9.10-fix-integer-overflow.patch
Patch7: libxml2-2.9.10-CVE-2020-24977.patch
# https://gitlab.gnome.org/GNOME/libxml2/-/merge_requests/87
Patch8: python-py_ssize_t.patch
# https://bugzilla.redhat.com/show_bug.cgi?id=1954227
Patch9: libxml2-2.9.10-CVE-2021-3516.patch
# https://bugzilla.redhat.com/show_bug.cgi?id=1954234
Patch10: libxml2-2.9.10-CVE-2021-3517.patch
# https://bugzilla.redhat.com/show_bug.cgi?id=1954243
Patch11: libxml2-2.9.10-CVE-2021-3518.patch
BuildRequires: gcc
BuildRequires: make
@ -153,6 +159,11 @@ gzip -9 -c doc/libxml2-api.xml > doc/libxml2-api.xml.gz
%{python3_sitearch}/libxml2mod.so
%changelog
* Wed May 05 2021 David King <amigadave@amigadave.com> - 2.9.10-11
- Fix CVE-2021-3516 (#1954227)
- Fix CVE-2021-3517 (#1954234)
- Fix CVE-2021-3518 (#1954243)
* Tue Jan 26 2021 Fedora Release Engineering <releng@fedoraproject.org> - 2.9.10-10
- Rebuilt for https://fedoraproject.org/wiki/Fedora_34_Mass_Rebuild