File size: 4,028 Bytes
6aaf86c
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
/*
 * xml.c: a libFuzzer target to test several XML parser interfaces.
 *
 * See Copyright for the status of this software.
 */

#include <libxml/catalog.h>
#include <libxml/parser.h>
#include <libxml/tree.h>
#include <libxml/xmlerror.h>
#include <libxml/xmlsave.h>
#include "fuzz.h"

int
LLVMFuzzerInitialize(int *argc ATTRIBUTE_UNUSED,
                     char ***argv ATTRIBUTE_UNUSED) {
    xmlFuzzMemSetup();
    xmlInitParser();
#ifdef LIBXML_CATALOG_ENABLED
    xmlInitializeCatalog();
    xmlCatalogSetDefaults(XML_CATA_ALLOW_NONE);
#endif

    return 0;
}

int
LLVMFuzzerTestOneInput(const char *data, size_t size) {
    xmlParserCtxtPtr ctxt;
    xmlDocPtr doc;
    const char *docBuffer, *docUrl;
    size_t failurePos, docSize;
    int opts;
#ifdef LIBXML_OUTPUT_ENABLED
    const char *saveEncoding;
    int saveOpts;
#endif

    xmlFuzzDataInit(data, size);
    opts = (int) xmlFuzzReadInt(4);
    /*
     * Disable options that are known to cause timeouts
     */
    opts &= ~XML_PARSE_XINCLUDE &
            ~XML_PARSE_DTDVALID &
            ~XML_PARSE_SAX1;
    failurePos = xmlFuzzReadInt(4) % (size + 100);

#ifdef LIBXML_OUTPUT_ENABLED
    /* TODO: Take from fuzz data */
    saveOpts = 0;
    saveEncoding = NULL;
#endif

    xmlFuzzReadEntities();
    docBuffer = xmlFuzzMainEntity(&docSize);
    docUrl = xmlFuzzMainUrl();
    if (docBuffer == NULL)
        goto exit;

    /* Pull parser */

    xmlFuzzInjectFailure(failurePos);
    ctxt = xmlNewParserCtxt();
    if (ctxt != NULL) {
        xmlCtxtSetErrorHandler(ctxt, xmlFuzzSErrorFunc, NULL);
        xmlCtxtSetResourceLoader(ctxt, xmlFuzzResourceLoader, NULL);
        doc = xmlCtxtReadMemory(ctxt, docBuffer, docSize, docUrl, NULL, opts);
        xmlFuzzCheckFailureReport("xmlCtxtReadMemory",
                doc == NULL && ctxt->errNo == XML_ERR_NO_MEMORY,
                doc == NULL && ctxt->errNo == XML_IO_EIO);

        if (doc != NULL) {
#ifdef LIBXML_OUTPUT_ENABLED
            xmlSaveCtxtPtr save;

            /* Also test the serializer. */
            save = xmlSaveToIO(xmlFuzzOutputWrite, xmlFuzzOutputClose, NULL,
                               saveEncoding, saveOpts);

            if (save != NULL) {
                int errNo;

                xmlSaveDoc(save, doc);
                errNo = xmlSaveFinish(save);
                xmlFuzzCheckFailureReport("xmlSaveDoc",
                                          errNo == XML_ERR_NO_MEMORY,
                                          errNo == XML_IO_EIO);
            }
#endif
            xmlFreeDoc(doc);
        }

        xmlFreeParserCtxt(ctxt);
    }

    /* Push parser */

#ifdef LIBXML_PUSH_ENABLED
    {
        static const size_t maxChunkSize = 128;
        size_t consumed, chunkSize;

        xmlFuzzInjectFailure(failurePos);
        /*
         * FIXME: xmlCreatePushParserCtxt can still report OOM errors
         * to stderr.
         */
        xmlSetGenericErrorFunc(NULL, xmlFuzzErrorFunc);
        ctxt = xmlCreatePushParserCtxt(NULL, NULL, NULL, 0, docUrl);
        xmlSetGenericErrorFunc(NULL, NULL);
        if (ctxt != NULL) {
            xmlCtxtSetErrorHandler(ctxt, xmlFuzzSErrorFunc, NULL);
            xmlCtxtSetResourceLoader(ctxt, xmlFuzzResourceLoader, NULL);
            xmlCtxtUseOptions(ctxt, opts);

            for (consumed = 0; consumed < docSize; consumed += chunkSize) {
                chunkSize = docSize - consumed;
                if (chunkSize > maxChunkSize)
                    chunkSize = maxChunkSize;
                xmlParseChunk(ctxt, docBuffer + consumed, chunkSize, 0);
            }

            xmlParseChunk(ctxt, NULL, 0, 1);
            xmlFuzzCheckFailureReport("xmlParseChunk",
                                      ctxt->errNo == XML_ERR_NO_MEMORY,
                                      ctxt->errNo == XML_IO_EIO);
            xmlFreeDoc(ctxt->myDoc);
            xmlFreeParserCtxt(ctxt);
        }
    }
#endif

exit:
    xmlFuzzInjectFailure(0);
    xmlFuzzDataCleanup();
    xmlResetLastError();
    return(0);
}