fuzz/xinclude.c

/*
 * xinclude.c: a libFuzzer target to test the XInclude engine.
 *
 * 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/xinclude.h>
#include <libxml/xmlreader.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
    xmlSetGenericErrorFunc(NULL, xmlFuzzErrorFunc);
    xmlSetExternalEntityLoader(xmlFuzzEntityLoader);

    return 0;
}

int
LLVMFuzzerTestOneInput(const char *data, size_t size) {
    xmlParserCtxtPtr ctxt;
    xmlDocPtr doc;
    const char *docBuffer, *docUrl;
    size_t maxAlloc, docSize;
    int opts;

    xmlFuzzDataInit(data, size);
    opts = (int) xmlFuzzReadInt(4);
    opts |= XML_PARSE_XINCLUDE;
    maxAlloc = xmlFuzzReadInt(4) % (size + 100);

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

    /* Pull parser */

    xmlFuzzMemSetLimit(maxAlloc);
    ctxt = xmlNewParserCtxt();
    if (ctxt != NULL) {
        xmlXIncludeCtxtPtr xinc;
        xmlDocPtr copy;

        doc = xmlCtxtReadMemory(ctxt, docBuffer, docSize, docUrl, NULL, opts);
        xmlFuzzCheckMallocFailure("xmlCtxtReadMemory",
                                  ctxt->errNo == XML_ERR_NO_MEMORY);

        xinc = xmlXIncludeNewContext(doc);
        xmlXIncludeSetFlags(xinc, opts);
        xmlXIncludeProcessNode(xinc, (xmlNodePtr) doc);
        if (doc != NULL) {
            xmlFuzzCheckMallocFailure("xmlXIncludeProcessNode",
                    xinc == NULL ||
                    xmlXIncludeGetLastError(xinc) == XML_ERR_NO_MEMORY);
        }
        xmlXIncludeFreeContext(xinc);

        xmlFuzzResetMallocFailed();
        copy = xmlCopyDoc(doc, 1);
        if (doc != NULL)
            xmlFuzzCheckMallocFailure("xmlCopyNode", copy == NULL);
        xmlFreeDoc(copy);

        xmlFreeDoc(doc);
        xmlFreeParserCtxt(ctxt);
    }

    /* Reader */

#ifdef LIBXML_READER_ENABLED
    {
        xmlTextReaderPtr reader;
        int j;

        xmlFuzzMemSetLimit(maxAlloc);
        reader = xmlReaderForMemory(docBuffer, docSize, NULL, NULL, opts);
        if (reader == NULL)
            goto exit;
        while (xmlTextReaderRead(reader) == 1) {
            if (xmlTextReaderNodeType(reader) == XML_ELEMENT_NODE) {
                int i, n = xmlTextReaderAttributeCount(reader);
                for (i=0; i<n; i++) {
                    xmlTextReaderMoveToAttributeNo(reader, i);
                    while (xmlTextReaderReadAttributeValue(reader) == 1);
                }
            }
        }
        for (j = 0; j < 10; j++)
            xmlTextReaderRead(reader);
        xmlFreeTextReader(reader);
    }
#endif

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