mirror of
https://gitlab.gnome.org/GNOME/libxml2.git
synced 2024-12-25 23:21:26 +03:00
484 lines
10 KiB
C
484 lines
10 KiB
C
/*
|
|
* fuzz.c: Common functions for fuzzing.
|
|
*
|
|
* See Copyright for the status of this software.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/stat.h>
|
|
|
|
#include <libxml/hash.h>
|
|
#include <libxml/parser.h>
|
|
#include <libxml/parserInternals.h>
|
|
#include <libxml/tree.h>
|
|
#include <libxml/xmlIO.h>
|
|
#include "fuzz.h"
|
|
|
|
typedef struct {
|
|
const char *data;
|
|
size_t size;
|
|
} xmlFuzzEntityInfo;
|
|
|
|
/* Single static instance for now */
|
|
static struct {
|
|
/* Original data */
|
|
const char *data;
|
|
size_t size;
|
|
|
|
/* Remaining data */
|
|
const char *ptr;
|
|
size_t remaining;
|
|
|
|
/* Buffer for unescaped strings */
|
|
char *outBuf;
|
|
char *outPtr; /* Free space at end of buffer */
|
|
|
|
xmlHashTablePtr entities; /* Maps URLs to xmlFuzzEntityInfos */
|
|
|
|
/* The first entity is the main entity. */
|
|
const char *mainUrl;
|
|
xmlFuzzEntityInfo *mainEntity;
|
|
} fuzzData;
|
|
|
|
size_t fuzzNumAllocs;
|
|
size_t fuzzMaxAllocs;
|
|
int fuzzAllocFailed;
|
|
|
|
/**
|
|
* xmlFuzzErrorFunc:
|
|
*
|
|
* An error function that simply discards all errors.
|
|
*/
|
|
void
|
|
xmlFuzzErrorFunc(void *ctx ATTRIBUTE_UNUSED, const char *msg ATTRIBUTE_UNUSED,
|
|
...) {
|
|
}
|
|
|
|
/*
|
|
* Malloc failure injection.
|
|
*
|
|
* To debug issues involving malloc failures, it's often helpful to set
|
|
* MALLOC_ABORT to 1. This should provide a backtrace of the failed
|
|
* allocation.
|
|
*/
|
|
|
|
#define XML_FUZZ_MALLOC_ABORT 0
|
|
|
|
static void *
|
|
xmlFuzzMalloc(size_t size) {
|
|
void *ret;
|
|
|
|
if (fuzzMaxAllocs > 0) {
|
|
fuzzNumAllocs += 1;
|
|
if (fuzzNumAllocs == fuzzMaxAllocs) {
|
|
#if XML_FUZZ_MALLOC_ABORT
|
|
abort();
|
|
#endif
|
|
fuzzAllocFailed = 1;
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
ret = malloc(size);
|
|
if (ret == NULL)
|
|
fuzzAllocFailed = 1;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void *
|
|
xmlFuzzRealloc(void *ptr, size_t size) {
|
|
void *ret;
|
|
|
|
if (fuzzMaxAllocs > 0) {
|
|
fuzzNumAllocs += 1;
|
|
if (fuzzNumAllocs == fuzzMaxAllocs) {
|
|
#if XML_FUZZ_MALLOC_ABORT
|
|
abort();
|
|
#endif
|
|
fuzzAllocFailed = 1;
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
ret = realloc(ptr, size);
|
|
if (ret == NULL)
|
|
fuzzAllocFailed = 1;
|
|
|
|
return ret;
|
|
}
|
|
|
|
void
|
|
xmlFuzzMemSetup(void) {
|
|
xmlMemSetup(free, xmlFuzzMalloc, xmlFuzzRealloc, xmlMemStrdup);
|
|
}
|
|
|
|
void
|
|
xmlFuzzMemSetLimit(size_t limit) {
|
|
fuzzNumAllocs = 0;
|
|
fuzzMaxAllocs = limit;
|
|
fuzzAllocFailed = 0;
|
|
}
|
|
|
|
int
|
|
xmlFuzzMallocFailed(void) {
|
|
return fuzzAllocFailed;
|
|
}
|
|
|
|
void
|
|
xmlFuzzResetMallocFailed(void) {
|
|
fuzzAllocFailed = 0;
|
|
}
|
|
|
|
void
|
|
xmlFuzzCheckMallocFailure(const char *func, int error) {
|
|
if (error >= 0 && fuzzAllocFailed != error) {
|
|
fprintf(stderr, "%s: malloc failure %s reported\n",
|
|
func, fuzzAllocFailed ? "not" : "erroneously");
|
|
abort();
|
|
}
|
|
fuzzAllocFailed = 0;
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzDataInit:
|
|
*
|
|
* Initialize fuzz data provider.
|
|
*/
|
|
void
|
|
xmlFuzzDataInit(const char *data, size_t size) {
|
|
fuzzData.data = data;
|
|
fuzzData.size = size;
|
|
fuzzData.ptr = data;
|
|
fuzzData.remaining = size;
|
|
|
|
fuzzData.outBuf = xmlMalloc(size + 1);
|
|
fuzzData.outPtr = fuzzData.outBuf;
|
|
|
|
fuzzData.entities = xmlHashCreate(8);
|
|
fuzzData.mainUrl = NULL;
|
|
fuzzData.mainEntity = NULL;
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzDataFree:
|
|
*
|
|
* Cleanup fuzz data provider.
|
|
*/
|
|
void
|
|
xmlFuzzDataCleanup(void) {
|
|
xmlFree(fuzzData.outBuf);
|
|
xmlHashFree(fuzzData.entities, xmlHashDefaultDeallocator);
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzWriteInt:
|
|
* @out: output file
|
|
* @v: integer to write
|
|
* @size: size of integer in bytes
|
|
*
|
|
* Write an integer to the fuzz data.
|
|
*/
|
|
void
|
|
xmlFuzzWriteInt(FILE *out, size_t v, int size) {
|
|
int shift;
|
|
|
|
while (size > (int) sizeof(size_t)) {
|
|
putc(0, out);
|
|
size--;
|
|
}
|
|
|
|
shift = size * 8;
|
|
while (shift > 0) {
|
|
shift -= 8;
|
|
putc((v >> shift) & 255, out);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzReadInt:
|
|
* @size: size of integer in bytes
|
|
*
|
|
* Read an integer from the fuzz data.
|
|
*/
|
|
size_t
|
|
xmlFuzzReadInt(int size) {
|
|
size_t ret = 0;
|
|
|
|
while ((size > 0) && (fuzzData.remaining > 0)) {
|
|
unsigned char c = (unsigned char) *fuzzData.ptr++;
|
|
fuzzData.remaining--;
|
|
ret = (ret << 8) | c;
|
|
size--;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzBytesRemaining:
|
|
*
|
|
* Return number of remaining bytes in fuzz data.
|
|
*/
|
|
size_t
|
|
xmlFuzzBytesRemaining(void) {
|
|
return(fuzzData.remaining);
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzReadRemaining:
|
|
* @size: size of string in bytes
|
|
*
|
|
* Read remaining bytes from fuzz data.
|
|
*/
|
|
const char *
|
|
xmlFuzzReadRemaining(size_t *size) {
|
|
const char *ret = fuzzData.ptr;
|
|
|
|
*size = fuzzData.remaining;
|
|
fuzzData.ptr += fuzzData.remaining;
|
|
fuzzData.remaining = 0;
|
|
|
|
return(ret);
|
|
}
|
|
|
|
/*
|
|
* xmlFuzzWriteString:
|
|
* @out: output file
|
|
* @str: string to write
|
|
*
|
|
* Write a random-length string to file in a format similar to
|
|
* FuzzedDataProvider. Backslash followed by newline marks the end of the
|
|
* string. Two backslashes are used to escape a backslash.
|
|
*/
|
|
void
|
|
xmlFuzzWriteString(FILE *out, const char *str) {
|
|
for (; *str; str++) {
|
|
int c = (unsigned char) *str;
|
|
putc(c, out);
|
|
if (c == '\\')
|
|
putc(c, out);
|
|
}
|
|
putc('\\', out);
|
|
putc('\n', out);
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzReadString:
|
|
* @size: size of string in bytes
|
|
*
|
|
* Read a random-length string from the fuzz data.
|
|
*
|
|
* The format is similar to libFuzzer's FuzzedDataProvider but treats
|
|
* backslash followed by newline as end of string. This makes the fuzz data
|
|
* more readable. A backslash character is escaped with another backslash.
|
|
*
|
|
* Returns a zero-terminated string or NULL if the fuzz data is exhausted.
|
|
*/
|
|
const char *
|
|
xmlFuzzReadString(size_t *size) {
|
|
const char *out = fuzzData.outPtr;
|
|
|
|
while (fuzzData.remaining > 0) {
|
|
int c = *fuzzData.ptr++;
|
|
fuzzData.remaining--;
|
|
|
|
if ((c == '\\') && (fuzzData.remaining > 0)) {
|
|
int c2 = *fuzzData.ptr;
|
|
|
|
if (c2 == '\n') {
|
|
fuzzData.ptr++;
|
|
fuzzData.remaining--;
|
|
if (size != NULL)
|
|
*size = fuzzData.outPtr - out;
|
|
*fuzzData.outPtr++ = '\0';
|
|
return(out);
|
|
}
|
|
if (c2 == '\\') {
|
|
fuzzData.ptr++;
|
|
fuzzData.remaining--;
|
|
}
|
|
}
|
|
|
|
*fuzzData.outPtr++ = c;
|
|
}
|
|
|
|
if (fuzzData.outPtr > out) {
|
|
if (size != NULL)
|
|
*size = fuzzData.outPtr - out;
|
|
*fuzzData.outPtr++ = '\0';
|
|
return(out);
|
|
}
|
|
|
|
if (size != NULL)
|
|
*size = 0;
|
|
return(NULL);
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzReadEntities:
|
|
*
|
|
* Read entities like the main XML file, external DTDs, external parsed
|
|
* entities from fuzz data.
|
|
*/
|
|
void
|
|
xmlFuzzReadEntities(void) {
|
|
size_t num = 0;
|
|
|
|
while (1) {
|
|
const char *url, *entity;
|
|
size_t urlSize, entitySize;
|
|
xmlFuzzEntityInfo *entityInfo;
|
|
|
|
url = xmlFuzzReadString(&urlSize);
|
|
if (url == NULL) break;
|
|
|
|
entity = xmlFuzzReadString(&entitySize);
|
|
if (entity == NULL) break;
|
|
|
|
/*
|
|
* Cap URL size to avoid quadratic behavior when generating
|
|
* error messages or looking up entities.
|
|
*/
|
|
if (urlSize < 50 &&
|
|
xmlHashLookup(fuzzData.entities, (xmlChar *)url) == NULL) {
|
|
entityInfo = xmlMalloc(sizeof(xmlFuzzEntityInfo));
|
|
if (entityInfo == NULL)
|
|
break;
|
|
entityInfo->data = entity;
|
|
entityInfo->size = entitySize;
|
|
|
|
xmlHashAddEntry(fuzzData.entities, (xmlChar *)url, entityInfo);
|
|
|
|
if (num == 0) {
|
|
fuzzData.mainUrl = url;
|
|
fuzzData.mainEntity = entityInfo;
|
|
}
|
|
|
|
num++;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzMainUrl:
|
|
*
|
|
* Returns the main URL.
|
|
*/
|
|
const char *
|
|
xmlFuzzMainUrl(void) {
|
|
return(fuzzData.mainUrl);
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzMainEntity:
|
|
* @size: size of the main entity in bytes
|
|
*
|
|
* Returns the main entity.
|
|
*/
|
|
const char *
|
|
xmlFuzzMainEntity(size_t *size) {
|
|
if (fuzzData.mainEntity == NULL)
|
|
return(NULL);
|
|
*size = fuzzData.mainEntity->size;
|
|
return(fuzzData.mainEntity->data);
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzResourceLoader:
|
|
*
|
|
* The resource loader for fuzz data.
|
|
*/
|
|
int
|
|
xmlFuzzResourceLoader(void *data ATTRIBUTE_UNUSED, const char *URL,
|
|
const char *ID ATTRIBUTE_UNUSED,
|
|
int type ATTRIBUTE_UNUSED, int flags ATTRIBUTE_UNUSED,
|
|
xmlParserInputPtr *out) {
|
|
xmlParserInputPtr input;
|
|
xmlFuzzEntityInfo *entity;
|
|
|
|
entity = xmlHashLookup(fuzzData.entities, (xmlChar *) URL);
|
|
if (entity == NULL)
|
|
return(XML_IO_ENOENT);
|
|
|
|
input = xmlInputCreateMemory(URL, entity->data, entity->size,
|
|
XML_INPUT_BUF_STATIC |
|
|
XML_INPUT_BUF_ZERO_TERMINATED);
|
|
if (input == NULL)
|
|
return(XML_ERR_NO_MEMORY);
|
|
|
|
*out = input;
|
|
return(XML_ERR_OK);
|
|
}
|
|
|
|
/**
|
|
* xmlFuzzEntityLoader:
|
|
*
|
|
* The entity loader for fuzz data.
|
|
*/
|
|
xmlParserInputPtr
|
|
xmlFuzzEntityLoader(const char *URL, const char *ID ATTRIBUTE_UNUSED,
|
|
xmlParserCtxtPtr ctxt) {
|
|
xmlParserInputPtr input;
|
|
xmlFuzzEntityInfo *entity;
|
|
|
|
if (URL == NULL)
|
|
return(NULL);
|
|
entity = xmlHashLookup(fuzzData.entities, (xmlChar *) URL);
|
|
if (entity == NULL)
|
|
return(NULL);
|
|
|
|
input = xmlNewInputStream(ctxt);
|
|
if (input == NULL)
|
|
return(NULL);
|
|
input->filename = (char *) xmlCharStrdup(URL);
|
|
if (input->filename == NULL) {
|
|
xmlCtxtErrMemory(ctxt);
|
|
xmlFreeInputStream(input);
|
|
return(NULL);
|
|
}
|
|
input->buf = xmlParserInputBufferCreateMem(entity->data, entity->size,
|
|
XML_CHAR_ENCODING_NONE);
|
|
if (input->buf == NULL) {
|
|
xmlCtxtErrMemory(ctxt);
|
|
xmlFreeInputStream(input);
|
|
return(NULL);
|
|
}
|
|
input->base = input->cur = xmlBufContent(input->buf->buffer);
|
|
input->end = input->base + xmlBufUse(input->buf->buffer);
|
|
|
|
return input;
|
|
}
|
|
|
|
char *
|
|
xmlSlurpFile(const char *path, size_t *sizeRet) {
|
|
FILE *file;
|
|
struct stat statbuf;
|
|
char *data;
|
|
size_t size;
|
|
|
|
if ((stat(path, &statbuf) != 0) || (!S_ISREG(statbuf.st_mode)))
|
|
return(NULL);
|
|
size = statbuf.st_size;
|
|
file = fopen(path, "rb");
|
|
if (file == NULL)
|
|
return(NULL);
|
|
data = xmlMalloc(size + 1);
|
|
if (data != NULL) {
|
|
if (fread(data, 1, size, file) != size) {
|
|
xmlFree(data);
|
|
data = NULL;
|
|
} else {
|
|
data[size] = 0;
|
|
if (sizeRet != NULL)
|
|
*sizeRet = size;
|
|
}
|
|
}
|
|
fclose(file);
|
|
|
|
return(data);
|
|
}
|
|
|