libxml2/fuzz/valid.c
Nick Wellnhofer 6f903d434f fuzz: Rework fixed parser options
Remove XML_PARSE_XINCLUDE. This is only honored by the XML Reader
interface which is now fuzzed in reader.c.

Don't validate in XInclude fuzzer. This doesn't increase coverage after
moving the Reader fuzzer.
2025-02-20 12:22:12 +01:00

140 lines
4.2 KiB
C

/*
* valid.c: a libFuzzer target to test DTD validation.
*
* 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 "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;
xmlFuzzDataInit(data, size);
opts = (int) xmlFuzzReadInt(4);
opts |= XML_PARSE_DTDVALID;
failurePos = xmlFuzzReadInt(4) % (size + 100);
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",
ctxt->errNo == XML_ERR_NO_MEMORY,
ctxt->errNo == XML_IO_EIO);
xmlFreeDoc(doc);
xmlFreeParserCtxt(ctxt);
}
/* Post validation */
xmlFuzzInjectFailure(failurePos);
ctxt = xmlNewParserCtxt();
if (ctxt != NULL) {
xmlCtxtSetErrorHandler(ctxt, xmlFuzzSErrorFunc, NULL);
xmlCtxtSetResourceLoader(ctxt, xmlFuzzResourceLoader, NULL);
doc = xmlCtxtReadMemory(ctxt, docBuffer, docSize, docUrl, NULL,
opts & ~XML_PARSE_DTDVALID);
xmlFuzzCheckFailureReport("xmlCtxtReadMemory",
doc == NULL && ctxt->errNo == XML_ERR_NO_MEMORY,
doc == NULL && ctxt->errNo == XML_IO_EIO);
if (doc != NULL) {
int valid = xmlCtxtValidateDocument(ctxt, doc);
xmlFuzzCheckFailureReport("xmlCtxtValidateDocument",
!valid && ctxt->errNo == XML_ERR_NO_MEMORY,
!valid && ctxt->errNo == XML_IO_EIO);
}
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);
}
size_t
LLVMFuzzerCustomMutator(char *data, size_t size, size_t maxSize,
unsigned seed) {
static const xmlFuzzChunkDesc chunks[] = {
{ 4, XML_FUZZ_PROB_ONE / 10 }, /* opts */
{ 4, XML_FUZZ_PROB_ONE / 10 }, /* failurePos */
{ 0, 0 }
};
return xmlFuzzMutateChunks(chunks, data, size, maxSize, seed,
LLVMFuzzerMutate);
}