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
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
Fix CVE-2016-5131:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-5131
Patches copied from upstream source repository (the test suite fails
without the 2nd patch):
https://git.gnome.org/browse/libxml2/commit/?id=9ab01a277d71f54d3143c2cf333c5c2e9aaedd9e
https://git.gnome.org/browse/libxml2/commit/?id=a005199330b86dada19d162cae15ef9bdcb6baa8
From 9ab01a277d71f54d3143c2cf333c5c2e9aaedd9e Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Tue, 28 Jun 2016 14:22:23 +0200
Subject: [PATCH] Fix XPointer paths beginning with range-to
The old code would invoke the broken xmlXPtrRangeToFunction. range-to
isn't really a function but a special kind of location step. Remove
this function and always handle range-to in the XPath code.
The old xmlXPtrRangeToFunction could also be abused to trigger a
use-after-free error with the potential for remote code execution.
Found with afl-fuzz.
Fixes CVE-2016-5131.
---
result/XPath/xptr/vidbase | 13 ++++++++
test/XPath/xptr/vidbase | 1 +
xpath.c | 7 ++++-
xpointer.c | 76 ++++-------------------------------------------
4 files changed, 26 insertions(+), 71 deletions(-)
diff --git a/result/XPath/xptr/vidbase b/result/XPath/xptr/vidbase
index 8b9e92d6..f19193e7 100644
--- a/result/XPath/xptr/vidbase
+++ b/result/XPath/xptr/vidbase
@@ -17,3 +17,16 @@ Object is a Location Set:
To node
ELEMENT p
+
+========================
+Expression: xpointer(range-to(id('chapter2')))
+Object is a Location Set:
+1 : Object is a range :
+ From node
+ /
+ To node
+ ELEMENT chapter
+ ATTRIBUTE id
+ TEXT
+ content=chapter2
+
diff --git a/test/XPath/xptr/vidbase b/test/XPath/xptr/vidbase
index b1463830..884b1065 100644
--- a/test/XPath/xptr/vidbase
+++ b/test/XPath/xptr/vidbase
@@ -1,2 +1,3 @@
xpointer(id('chapter1')/p)
xpointer(id('chapter1')/p[1]/range-to(following-sibling::p[2]))
+xpointer(range-to(id('chapter2')))
diff --git a/xpath.c b/xpath.c
index d992841e..5a01b1b3 100644
--- a/xpath.c
+++ b/xpath.c
@@ -10691,13 +10691,18 @@ xmlXPathCompPathExpr(xmlXPathParserContextPtr ctxt) {
lc = 1;
break;
} else if ((NXT(len) == '(')) {
- /* Note Type or Function */
+ /* Node Type or Function */
if (xmlXPathIsNodeType(name)) {
#ifdef DEBUG_STEP
xmlGenericError(xmlGenericErrorContext,
"PathExpr: Type search\n");
#endif
lc = 1;
+#ifdef LIBXML_XPTR_ENABLED
+ } else if (ctxt->xptr &&
+ xmlStrEqual(name, BAD_CAST "range-to")) {
+ lc = 1;
+#endif
} else {
#ifdef DEBUG_STEP
xmlGenericError(xmlGenericErrorContext,
diff --git a/xpointer.c b/xpointer.c
index 676c5105..d74174a3 100644
--- a/xpointer.c
+++ b/xpointer.c
@@ -1332,8 +1332,6 @@ xmlXPtrNewContext(xmlDocPtr doc, xmlNodePtr here, xmlNodePtr origin) {
ret->here = here;
ret->origin = origin;
- xmlXPathRegisterFunc(ret, (xmlChar *)"range-to",
- xmlXPtrRangeToFunction);
xmlXPathRegisterFunc(ret, (xmlChar *)"range",
xmlXPtrRangeFunction);
xmlXPathRegisterFunc(ret, (xmlChar *)"range-inside",
@@ -2243,76 +2241,14 @@ xmlXPtrRangeInsideFunction(xmlXPathParserContextPtr ctxt, int nargs) {
* @nargs: the number of args
*
* Implement the range-to() XPointer function
+ *
+ * Obsolete. range-to is not a real function but a special type of location
+ * step which is handled in xpath.c.
*/
void
-xmlXPtrRangeToFunction(xmlXPathParserContextPtr ctxt, int nargs) {
- xmlXPathObjectPtr range;
- const xmlChar *cur;
- xmlXPathObjectPtr res, obj;
- xmlXPathObjectPtr tmp;
- xmlLocationSetPtr newset = NULL;
- xmlNodeSetPtr oldset;
- int i;
-
- if (ctxt == NULL) return;
- CHECK_ARITY(1);
- /*
- * Save the expression pointer since we will have to evaluate
- * it multiple times. Initialize the new set.
- */
- CHECK_TYPE(XPATH_NODESET);
- obj = valuePop(ctxt);
- oldset = obj->nodesetval;
- ctxt->context->node = NULL;
-
- cur = ctxt->cur;
- newset = xmlXPtrLocationSetCreate(NULL);
-
- for (i = 0; i < oldset->nodeNr; i++) {
- ctxt->cur = cur;
-
- /*
- * Run the evaluation with a node list made of a single item
- * in the nodeset.
- */
- ctxt->context->node = oldset->nodeTab[i];
- tmp = xmlXPathNewNodeSet(ctxt->context->node);
- valuePush(ctxt, tmp);
-
- xmlXPathEvalExpr(ctxt);
- CHECK_ERROR;
-
- /*
- * The result of the evaluation need to be tested to
- * decided whether the filter succeeded or not
- */
- res = valuePop(ctxt);
- range = xmlXPtrNewRangeNodeObject(oldset->nodeTab[i], res);
- if (range != NULL) {
- xmlXPtrLocationSetAdd(newset, range);
- }
-
- /*
- * Cleanup
- */
- if (res != NULL)
- xmlXPathFreeObject(res);
- if (ctxt->value == tmp) {
- res = valuePop(ctxt);
- xmlXPathFreeObject(res);
- }
-
- ctxt->context->node = NULL;
- }
-
- /*
- * The result is used as the new evaluation set.
- */
- xmlXPathFreeObject(obj);
- ctxt->context->node = NULL;
- ctxt->context->contextSize = -1;
- ctxt->context->proximityPosition = -1;
- valuePush(ctxt, xmlXPtrWrapLocationSet(newset));
+xmlXPtrRangeToFunction(xmlXPathParserContextPtr ctxt,
+ int nargs ATTRIBUTE_UNUSED) {
+ XP_ERROR(XPATH_EXPR_ERROR);
}
/**
--
2.11.0
From a005199330b86dada19d162cae15ef9bdcb6baa8 Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Tue, 28 Jun 2016 14:19:58 +0200
Subject: [PATCH] Fix comparison with root node in xmlXPathCmpNodes
This change has already been made in xmlXPathCmpNodesExt but not in
xmlXPathCmpNodes.
---
xpath.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/xpath.c b/xpath.c
index 751665b8..d992841e 100644
--- a/xpath.c
+++ b/xpath.c
@@ -3342,13 +3342,13 @@ xmlXPathCmpNodes(xmlNodePtr node1, xmlNodePtr node2) {
* compute depth to root
*/
for (depth2 = 0, cur = node2;cur->parent != NULL;cur = cur->parent) {
- if (cur == node1)
+ if (cur->parent == node1)
return(1);
depth2++;
}
root = cur;
for (depth1 = 0, cur = node1;cur->parent != NULL;cur = cur->parent) {
- if (cur == node2)
+ if (cur->parent == node2)
return(-1);
depth1++;
}
--
2.11.0
|