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Fix CVE-2021-3518 (#1957029)

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Resolves: #1957029
Resolves: CVE-2021-3518
This commit is contained in:
David King 2021-05-13 15:03:52 +01:00
parent 90e67115f4
commit 86430a8e54
2 changed files with 250 additions and 0 deletions
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247
libxml2-2.9.10-CVE-2021-3518.patch Normal file
View File

@ -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

3
libxml2.spec
View File

@ -26,6 +26,8 @@ Patch8: python-py_ssize_t.patch
Patch9: libxml2-2.9.10-CVE-2021-3516.patch Patch9: libxml2-2.9.10-CVE-2021-3516.patch
# https://bugzilla.redhat.com/show_bug.cgi?id=1957002 # https://bugzilla.redhat.com/show_bug.cgi?id=1957002
Patch10: libxml2-2.9.10-CVE-2021-3517.patch Patch10: libxml2-2.9.10-CVE-2021-3517.patch
# https://bugzilla.redhat.com/show_bug.cgi?id=1957029
Patch11: libxml2-2.9.10-CVE-2021-3518.patch
BuildRequires: gcc BuildRequires: gcc
BuildRequires: make BuildRequires: make
@ -160,6 +162,7 @@ gzip -9 -c doc/libxml2-api.xml > doc/libxml2-api.xml.gz
* Thu May 13 2021 David King <dking@redhat.com> - 2.9.10-12 * Thu May 13 2021 David King <dking@redhat.com> - 2.9.10-12
- Fix CVE-2021-3516 (#1956969) - Fix CVE-2021-3516 (#1956969)
- Fix CVE-2021-3517 (#1957002) - Fix CVE-2021-3517 (#1957002)
- Fix CVE-2021-3518 (#1957029)
* Fri Apr 16 2021 Mohan Boddu <mboddu@redhat.com> - 2.9.10-11 * Fri Apr 16 2021 Mohan Boddu <mboddu@redhat.com> - 2.9.10-11
- Rebuilt for RHEL 9 BETA on Apr 15th 2021. Related: rhbz#1947937 - Rebuilt for RHEL 9 BETA on Apr 15th 2021. Related: rhbz#1947937