blob: dbd68c65d8de9a1082900d6280b263b79c145763 [file] [log] [blame]
/*
*
* honggfuzz - fuzzing routines
* -----------------------------------------
*
* Author:
* Robert Swiecki <swiecki@google.com>
* Felix Gröbert <groebert@google.com>
*
* Copyright 2010-2015 by Google Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License. You may obtain
* a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License.
*
*/
#include "common.h"
#include "fuzz.h"
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <pthread.h>
#include <signal.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include "arch.h"
#include "files.h"
#include "log.h"
#include "mangle.h"
#include "report.h"
#include "util.h"
static void fuzz_getFileName(honggfuzz_t * hfuzz, char *fileName)
{
struct timeval tv;
gettimeofday(&tv, NULL);
snprintf(fileName, PATH_MAX, ".honggfuzz.%d.%lu.%llx.%s", (int)getpid(),
(unsigned long int)tv.tv_sec, (unsigned long long int)util_rndGet(0, 1ULL << 62),
hfuzz->fileExtn);
return;
}
static bool fuzz_prepareFileDynamically(honggfuzz_t * hfuzz, fuzzer_t * fuzzer, int rnd_index)
{
while (pthread_mutex_lock(&hfuzz->dynamicFile_mutex)) ;
if (hfuzz->inputFile && hfuzz->branchBestCnt == 0) {
size_t fileSz = files_readFileToBufMax(hfuzz->files[rnd_index], hfuzz->dynamicFileBest,
hfuzz->maxFileSz);
if (fileSz == 0) {
while (pthread_mutex_unlock(&hfuzz->dynamicFile_mutex)) ;
LOGMSG(l_ERROR, "Couldn't read '%s'", hfuzz->files[rnd_index]);
return false;
}
hfuzz->dynamicFileBestSz = fileSz;
}
if (hfuzz->dynamicFileBestSz > hfuzz->maxFileSz) {
LOGMSG(l_FATAL, "Current BEST file Sz > maxFileSz (%zu > %zu)", hfuzz->dynamicFileBestSz,
hfuzz->maxFileSz);
}
fuzzer->dynamicFileSz = hfuzz->dynamicFileBestSz;
memcpy(fuzzer->dynamicFile, hfuzz->dynamicFileBest, hfuzz->dynamicFileBestSz);
while (pthread_mutex_unlock(&hfuzz->dynamicFile_mutex)) ;
/* The first pass should be on an empty/initial file */
if (hfuzz->branchBestCnt > 0) {
mangle_Resize(hfuzz, &fuzzer->dynamicFileSz);
mangle_mangleContent(hfuzz, fuzzer->dynamicFile, fuzzer->dynamicFileSz);
}
if (files_writeBufToFile
(fuzzer->fileName, fuzzer->dynamicFile, fuzzer->dynamicFileSz,
O_WRONLY | O_CREAT | O_EXCL | O_TRUNC) == false) {
LOGMSG(l_ERROR, "Couldn't write buffer to file '%s'", fuzzer->fileName);
return false;
}
return true;
}
static bool fuzz_prepareFile(honggfuzz_t * hfuzz, fuzzer_t * fuzzer, int rnd_index)
{
size_t fileSz =
files_readFileToBufMax(hfuzz->files[rnd_index], fuzzer->dynamicFile, hfuzz->maxFileSz);
if (fileSz == 0UL) {
LOGMSG(l_ERROR, "Couldn't read contents of '%s'", hfuzz->files[rnd_index]);
return false;
}
mangle_Resize(hfuzz, &fileSz);
mangle_mangleContent(hfuzz, fuzzer->dynamicFile, fileSz);
if (files_writeBufToFile
(fuzzer->fileName, fuzzer->dynamicFile, fileSz, O_WRONLY | O_CREAT | O_EXCL) == false) {
LOGMSG(l_ERROR, "Couldn't write buffer to file '%s'", fuzzer->fileName);
return false;
}
return true;
}
static bool fuzz_prepareFileExternally(honggfuzz_t * hfuzz, fuzzer_t * fuzzer, int rnd_index)
{
int dstfd = open(fuzzer->fileName, O_CREAT | O_EXCL | O_RDWR, 0644);
if (dstfd == -1) {
LOGMSG_P(l_ERROR, "Couldn't create a temporary file '%s' in the current directory",
fuzzer->fileName);
return false;
}
LOGMSG(l_DEBUG, "Created '%f' as an input file", fuzzer->fileName);
if (hfuzz->inputFile) {
size_t fileSz =
files_readFileToBufMax(hfuzz->files[rnd_index], fuzzer->dynamicFile, hfuzz->maxFileSz);
if (fileSz == 0UL) {
LOGMSG(l_ERROR, "Couldn't read '%s'", hfuzz->files[rnd_index]);
unlink(fuzzer->fileName);
return false;
}
if (files_writeToFd(dstfd, fuzzer->dynamicFile, fileSz) == false) {
close(dstfd);
unlink(fuzzer->fileName);
return false;
}
}
close(dstfd);
pid_t pid = vfork();
if (pid == -1) {
LOGMSG_P(l_ERROR, "Couldn't vfork");
return false;
}
if (!pid) {
/*
* child performs the external file modifications
*/
execl(hfuzz->externalCommand, hfuzz->externalCommand, fuzzer->fileName, NULL);
LOGMSG_P(l_FATAL, "Couldn't execute '%s %s'", hfuzz->externalCommand, fuzzer->fileName);
return false;
}
/*
* parent waits until child is done fuzzing the input file
*/
int childStatus;
int flags = 0;
#if defined(__WNOTHREAD)
flags |= __WNOTHREAD;
#endif /* defined(__WNOTHREAD) */
while (wait4(pid, &childStatus, flags, NULL) != pid) ;
if (WIFEXITED(childStatus)) {
LOGMSG(l_DEBUG, "External command exited with status %d", WEXITSTATUS(childStatus));
return true;
}
if (WIFSIGNALED(childStatus)) {
LOGMSG(l_ERROR, "External command terminated with signal %d", WTERMSIG(childStatus));
return false;
}
LOGMSG(l_FATAL, "External command terminated abnormally, status: %d", childStatus);
return false;
abort(); /* NOTREACHED */
}
static int fuzz_numOfProc(honggfuzz_t * hfuzz)
{
int i;
sem_getvalue(hfuzz->sem, &i);
return hfuzz->threadsMax - i;
}
static void *fuzz_threadNew(void *arg)
{
honggfuzz_t *hfuzz = (honggfuzz_t *) arg;
fuzzer_t fuzzer = {
.pid = 0,
.timeStarted = time(NULL),
.pc = 0ULL,
.backtrace = 0ULL,
.access = 0ULL,
.exception = 0,
.dynamicFileSz = 0,
.dynamicFile = malloc(hfuzz->maxFileSz),
.branchCnt = 0,
.report = {'\0'}
};
if (fuzzer.dynamicFile == NULL) {
LOGMSG(l_FATAL, "malloc(%zu) failed", hfuzz->maxFileSz);
}
int rnd_index = util_rndGet(0, hfuzz->fileCnt - 1);
strncpy(fuzzer.origFileName, files_basename(hfuzz->files[rnd_index]), PATH_MAX);
fuzz_getFileName(hfuzz, fuzzer.fileName);
if (hfuzz->dynFileMethod != _HF_DYNFILE_NONE) {
if (!fuzz_prepareFileDynamically(hfuzz, &fuzzer, rnd_index)) {
exit(EXIT_FAILURE);
}
} else if (hfuzz->externalCommand != NULL) {
if (!fuzz_prepareFileExternally(hfuzz, &fuzzer, rnd_index)) {
exit(EXIT_FAILURE);
}
} else {
if (!fuzz_prepareFile(hfuzz, &fuzzer, rnd_index)) {
exit(EXIT_FAILURE);
}
}
#if defined(_HF_ARCH_LINUX)
#include <unistd.h>
#include <sys/syscall.h>
fuzzer.pid = syscall(__NR_fork);
#else /* defined(_HF_ARCH_LINUX) */
fuzzer.pid = fork();
#endif /* defined(_HF_ARCH_LINUX) */
if (fuzzer.pid == -1) {
LOGMSG_P(l_FATAL, "Couldn't fork");
exit(EXIT_FAILURE);
}
if (!fuzzer.pid) {
/*
* Ok, kill the parent if this fails
*/
if (!arch_launchChild(hfuzz, fuzzer.fileName)) {
LOGMSG(l_ERROR, "Error launching child process, killing parent");
exit(EXIT_FAILURE);
}
}
LOGMSG(l_INFO, "Launched new process, pid: %d, (%d/%d)", fuzzer.pid, fuzz_numOfProc(hfuzz),
hfuzz->threadsMax);
arch_reapChild(hfuzz, &fuzzer);
unlink(fuzzer.fileName);
if (hfuzz->dynFileMethod != _HF_DYNFILE_NONE) {
while (pthread_mutex_lock(&hfuzz->dynamicFile_mutex)) ;
if (fuzzer.branchCnt >= hfuzz->branchBestCnt) {
LOGMSG(l_INFO,
"New BEST feedback: File Size (New/Old): %zu/%zu', Perf feedback (Curr/High): %"
PRId64 "/%" PRId64, fuzzer.dynamicFileSz, hfuzz->dynamicFileBestSz,
fuzzer.branchCnt, hfuzz->branchBestCnt);
memcpy(hfuzz->dynamicFileBest, fuzzer.dynamicFile, fuzzer.dynamicFileSz);
hfuzz->dynamicFileBestSz = fuzzer.dynamicFileSz;
hfuzz->branchBestCnt = fuzzer.branchCnt;
#define _HF_CURRENT_BEST "CURRENT_BEST"
#define _HF_CURRENT_BEST_TMP ".tmp.CURRENT_BEST"
if (files_writeBufToFile
(_HF_CURRENT_BEST_TMP, fuzzer.dynamicFile, fuzzer.dynamicFileSz,
O_WRONLY | O_CREAT | O_TRUNC)) {
rename(_HF_CURRENT_BEST_TMP, _HF_CURRENT_BEST);
} else {
unlink(_HF_CURRENT_BEST_TMP);
}
}
while (pthread_mutex_unlock(&hfuzz->dynamicFile_mutex)) ;
}
report_Report(hfuzz, fuzzer.report);
free(fuzzer.dynamicFile);
sem_post(hfuzz->sem);
return NULL;
}
static void *fuzz_threadPid(void *arg)
{
honggfuzz_t *hfuzz = (honggfuzz_t *) arg;
if (!arch_archInit(hfuzz)) {
LOGMSG(l_FATAL, "Couldn't prepare parent for fuzzing");
}
fuzzer_t fuzzer = {
.pid = hfuzz->pid,
.timeStarted = time(NULL),
.pc = 0ULL,
.backtrace = 0ULL,
.access = 0ULL,
.exception = 0,
.dynamicFileSz = 0,
.dynamicFile = malloc(hfuzz->maxFileSz),
.branchCnt = 0,
.report = {'\0'}
};
if (fuzzer.dynamicFile == NULL) {
LOGMSG(l_FATAL, "malloc(%zu) failed", hfuzz->maxFileSz);
}
char fileName[] = ".honggfuzz.empty.XXXXXX";
int fd;
if ((fd = mkstemp(fileName)) == -1) {
free(fuzzer.dynamicFile);
LOGMSG_P(l_ERROR, "Couldn't create a temporary file");
return NULL;
}
close(fd);
strncpy(fuzzer.origFileName, "PID_FUZZING", PATH_MAX);
strncpy(fuzzer.fileName, fileName, PATH_MAX);
arch_reapChild(hfuzz, &fuzzer);
unlink(fuzzer.fileName);
report_Report(hfuzz, fuzzer.report);
free(fuzzer.dynamicFile);
// There's no more hfuzz->pid to analyze. Just exit
LOGMSG(l_INFO, "PID: %d exited. Exiting", fuzzer.pid);
exit(EXIT_SUCCESS);
return NULL;
}
static void fuzz_runThread(honggfuzz_t * hfuzz, void *(*thread) (void *))
{
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
pthread_attr_setstacksize(&attr, _HF_PTHREAD_STACKSIZE);
pthread_attr_setguardsize(&attr, (size_t) sysconf(_SC_PAGESIZE));
pthread_t t;
if (pthread_create(&t, &attr, thread, (void *)hfuzz) < 0) {
LOGMSG_P(l_FATAL, "Couldn't create a new thread");
}
return;
}
void fuzz_main(honggfuzz_t * hfuzz)
{
char semName[PATH_MAX];
snprintf(semName, sizeof(semName), "/honggfuzz.%d.%d.%" PRIx64, getpid(),
(int)time(NULL), util_rndGet(1, 1ULL << 62));
hfuzz->sem = sem_open(semName, O_CREAT, 0644, hfuzz->threadsMax);
if (hfuzz->sem == SEM_FAILED) {
LOGMSG_P(l_FATAL, "sem_open() failed");
}
// If we're doing a PID fuzzing, the parent of the PID will be a
// dedicated thread anyway
if (hfuzz->pid) {
fuzz_runThread(hfuzz, fuzz_threadPid);
} else {
if (!arch_archInit(hfuzz)) {
LOGMSG(l_FATAL, "Couldn't prepare parent for fuzzing");
}
}
for (;;) {
if (sem_wait(hfuzz->sem) == -1) {
LOGMSG_P(l_FATAL, "sem_wait() failed");
}
if (hfuzz->mutationsMax && (hfuzz->mutationsCnt >= hfuzz->mutationsMax)) {
#if defined(_HF_ARCH_DARWIN)
/*
* Sleep a bit to let any running fuzzers terminate
*/
usleep(1.2 * hfuzz->tmOut * 1000000);
#else /* defined(_HF_ARCH_DARWIN) */
while (fuzz_numOfProc(hfuzz) > 1) {
usleep(10000);
}
#endif /* defined(_HF_ARCH_DARWIN) */
LOGMSG(l_INFO, "Finished fuzzing %ld times.", hfuzz->mutationsMax);
sem_destroy(hfuzz->sem);
exit(EXIT_SUCCESS);
}
hfuzz->mutationsCnt++;
fuzz_runThread(hfuzz, fuzz_threadNew);
}
}