aboutsummaryrefslogtreecommitdiff
path: root/gnu/packages/patches/libxml2-CVE-2016-4658.patch
blob: a4e1f31fae90466602c81b323b52dbf97489c885 (plain)
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
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
Fix CVE-2016-4658:

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-4658

Patch copied from upstream source repository:

https://git.gnome.org/browse/libxml2/commit/?id=c1d1f7121194036608bf555f08d3062a36fd344b

From c1d1f7121194036608bf555f08d3062a36fd344b Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Tue, 28 Jun 2016 18:34:52 +0200
Subject: [PATCH] Disallow namespace nodes in XPointer ranges

Namespace nodes must be copied to avoid use-after-free errors.
But they don't necessarily have a physical representation in a
document, so simply disallow them in XPointer ranges.

Found with afl-fuzz.

Fixes CVE-2016-4658.
---
 xpointer.c | 149 +++++++++++++++++++++++--------------------------------------
 1 file changed, 56 insertions(+), 93 deletions(-)

diff --git a/xpointer.c b/xpointer.c
index a7b03fbd..694d120e 100644
--- a/xpointer.c
+++ b/xpointer.c
@@ -320,6 +320,45 @@ xmlXPtrRangesEqual(xmlXPathObjectPtr range1, xmlXPathObjectPtr range2) {
 }
 
 /**
+ * xmlXPtrNewRangeInternal:
+ * @start:  the starting node
+ * @startindex:  the start index
+ * @end:  the ending point
+ * @endindex:  the ending index
+ *
+ * Internal function to create a new xmlXPathObjectPtr of type range
+ *
+ * Returns the newly created object.
+ */
+static xmlXPathObjectPtr
+xmlXPtrNewRangeInternal(xmlNodePtr start, int startindex,
+                        xmlNodePtr end, int endindex) {
+    xmlXPathObjectPtr ret;
+
+    /*
+     * Namespace nodes must be copied (see xmlXPathNodeSetDupNs).
+     * Disallow them for now.
+     */
+    if ((start != NULL) && (start->type == XML_NAMESPACE_DECL))
+	return(NULL);
+    if ((end != NULL) && (end->type == XML_NAMESPACE_DECL))
+	return(NULL);
+
+    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
+    if (ret == NULL) {
+        xmlXPtrErrMemory("allocating range");
+	return(NULL);
+    }
+    memset(ret, 0, sizeof(xmlXPathObject));
+    ret->type = XPATH_RANGE;
+    ret->user = start;
+    ret->index = startindex;
+    ret->user2 = end;
+    ret->index2 = endindex;
+    return(ret);
+}
+
+/**
  * xmlXPtrNewRange:
  * @start:  the starting node
  * @startindex:  the start index
@@ -344,17 +383,7 @@ xmlXPtrNewRange(xmlNodePtr start, int startindex,
     if (endindex < 0)
 	return(NULL);
 
-    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
-    if (ret == NULL) {
-        xmlXPtrErrMemory("allocating range");
-	return(NULL);
-    }
-    memset(ret, 0 , (size_t) sizeof(xmlXPathObject));
-    ret->type = XPATH_RANGE;
-    ret->user = start;
-    ret->index = startindex;
-    ret->user2 = end;
-    ret->index2 = endindex;
+    ret = xmlXPtrNewRangeInternal(start, startindex, end, endindex);
     xmlXPtrRangeCheckOrder(ret);
     return(ret);
 }
@@ -381,17 +410,8 @@ xmlXPtrNewRangePoints(xmlXPathObjectPtr start, xmlXPathObjectPtr end) {
     if (end->type != XPATH_POINT)
 	return(NULL);
 
-    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
-    if (ret == NULL) {
-        xmlXPtrErrMemory("allocating range");
-	return(NULL);
-    }
-    memset(ret, 0 , (size_t) sizeof(xmlXPathObject));
-    ret->type = XPATH_RANGE;
-    ret->user = start->user;
-    ret->index = start->index;
-    ret->user2 = end->user;
-    ret->index2 = end->index;
+    ret = xmlXPtrNewRangeInternal(start->user, start->index, end->user,
+                                  end->index);
     xmlXPtrRangeCheckOrder(ret);
     return(ret);
 }
@@ -416,17 +436,7 @@ xmlXPtrNewRangePointNode(xmlXPathObjectPtr start, xmlNodePtr end) {
     if (start->type != XPATH_POINT)
 	return(NULL);
 
-    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
-    if (ret == NULL) {
-        xmlXPtrErrMemory("allocating range");
-	return(NULL);
-    }
-    memset(ret, 0 , (size_t) sizeof(xmlXPathObject));
-    ret->type = XPATH_RANGE;
-    ret->user = start->user;
-    ret->index = start->index;
-    ret->user2 = end;
-    ret->index2 = -1;
+    ret = xmlXPtrNewRangeInternal(start->user, start->index, end, -1);
     xmlXPtrRangeCheckOrder(ret);
     return(ret);
 }
@@ -453,17 +463,7 @@ xmlXPtrNewRangeNodePoint(xmlNodePtr start, xmlXPathObjectPtr end) {
     if (end->type != XPATH_POINT)
 	return(NULL);
 
-    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
-    if (ret == NULL) {
-        xmlXPtrErrMemory("allocating range");
-	return(NULL);
-    }
-    memset(ret, 0 , (size_t) sizeof(xmlXPathObject));
-    ret->type = XPATH_RANGE;
-    ret->user = start;
-    ret->index = -1;
-    ret->user2 = end->user;
-    ret->index2 = end->index;
+    ret = xmlXPtrNewRangeInternal(start, -1, end->user, end->index);
     xmlXPtrRangeCheckOrder(ret);
     return(ret);
 }
@@ -486,17 +486,7 @@ xmlXPtrNewRangeNodes(xmlNodePtr start, xmlNodePtr end) {
     if (end == NULL)
 	return(NULL);
 
-    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
-    if (ret == NULL) {
-        xmlXPtrErrMemory("allocating range");
-	return(NULL);
-    }
-    memset(ret, 0 , (size_t) sizeof(xmlXPathObject));
-    ret->type = XPATH_RANGE;
-    ret->user = start;
-    ret->index = -1;
-    ret->user2 = end;
-    ret->index2 = -1;
+    ret = xmlXPtrNewRangeInternal(start, -1, end, -1);
     xmlXPtrRangeCheckOrder(ret);
     return(ret);
 }
@@ -516,17 +506,7 @@ xmlXPtrNewCollapsedRange(xmlNodePtr start) {
     if (start == NULL)
 	return(NULL);
 
-    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
-    if (ret == NULL) {
-        xmlXPtrErrMemory("allocating range");
-	return(NULL);
-    }
-    memset(ret, 0 , (size_t) sizeof(xmlXPathObject));
-    ret->type = XPATH_RANGE;
-    ret->user = start;
-    ret->index = -1;
-    ret->user2 = NULL;
-    ret->index2 = -1;
+    ret = xmlXPtrNewRangeInternal(start, -1, NULL, -1);
     return(ret);
 }
 
@@ -541,6 +521,8 @@ xmlXPtrNewCollapsedRange(xmlNodePtr start) {
  */
 xmlXPathObjectPtr
 xmlXPtrNewRangeNodeObject(xmlNodePtr start, xmlXPathObjectPtr end) {
+    xmlNodePtr endNode;
+    int endIndex;
     xmlXPathObjectPtr ret;
 
     if (start == NULL)
@@ -549,7 +531,12 @@ xmlXPtrNewRangeNodeObject(xmlNodePtr start, xmlXPathObjectPtr end) {
 	return(NULL);
     switch (end->type) {
 	case XPATH_POINT:
+	    endNode = end->user;
+	    endIndex = end->index;
+	    break;
 	case XPATH_RANGE:
+	    endNode = end->user2;
+	    endIndex = end->index2;
 	    break;
 	case XPATH_NODESET:
 	    /*
@@ -557,39 +544,15 @@ xmlXPtrNewRangeNodeObject(xmlNodePtr start, xmlXPathObjectPtr end) {
 	     */
 	    if (end->nodesetval->nodeNr <= 0)
 		return(NULL);
+	    endNode = end->nodesetval->nodeTab[end->nodesetval->nodeNr - 1];
+	    endIndex = -1;
 	    break;
 	default:
 	    /* TODO */
 	    return(NULL);
     }
 
-    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
-    if (ret == NULL) {
-        xmlXPtrErrMemory("allocating range");
-	return(NULL);
-    }
-    memset(ret, 0 , (size_t) sizeof(xmlXPathObject));
-    ret->type = XPATH_RANGE;
-    ret->user = start;
-    ret->index = -1;
-    switch (end->type) {
-	case XPATH_POINT:
-	    ret->user2 = end->user;
-	    ret->index2 = end->index;
-	    break;
-	case XPATH_RANGE:
-	    ret->user2 = end->user2;
-	    ret->index2 = end->index2;
-	    break;
-	case XPATH_NODESET: {
-	    ret->user2 = end->nodesetval->nodeTab[end->nodesetval->nodeNr - 1];
-	    ret->index2 = -1;
-	    break;
-	}
-	default:
-	    STRANGE
-	    return(NULL);
-    }
+    ret = xmlXPtrNewRangeInternal(start, -1, endNode, endIndex);
     xmlXPtrRangeCheckOrder(ret);
     return(ret);
 }
-- 
2.11.0