blob: 2e3f78c5a0c79833ee75f97b11f6786979a63250 [file] [log] [blame]
/*
*
* honggfuzz - fuzzing routines
* -----------------------------------------
*
* Authors: Robert Swiecki <swiecki@google.com>
* Felix Gröbert <groebert@google.com>
*
* Copyright 2010-2018 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 "fuzz.h"
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <libgen.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 <time.h>
#include <unistd.h>
#include "arch.h"
#include "honggfuzz.h"
#include "input.h"
#include "libhfcommon/common.h"
#include "libhfcommon/files.h"
#include "libhfcommon/log.h"
#include "libhfcommon/util.h"
#include "mangle.h"
#include "report.h"
#include "sanitizers.h"
#include "socketfuzzer.h"
#include "subproc.h"
static time_t termTimeStamp = 0;
bool fuzz_isTerminating(void) {
if (ATOMIC_GET(termTimeStamp) != 0) {
return true;
}
return false;
}
void fuzz_setTerminating(void) {
if (ATOMIC_GET(termTimeStamp) != 0) {
return;
}
ATOMIC_SET(termTimeStamp, time(NULL));
}
bool fuzz_shouldTerminate() {
if (ATOMIC_GET(termTimeStamp) == 0) {
return false;
}
if ((time(NULL) - ATOMIC_GET(termTimeStamp)) > 5) {
return true;
}
return false;
}
static fuzzState_t fuzz_getState(honggfuzz_t* hfuzz) {
return ATOMIC_GET(hfuzz->feedback.state);
}
static bool fuzz_writeCovFile(const char* dir, const uint8_t* data, size_t len) {
char fname[PATH_MAX];
uint64_t crc64f = util_CRC64(data, len);
uint64_t crc64r = util_CRC64Rev(data, len);
snprintf(fname, sizeof(fname), "%s/%016" PRIx64 "%016" PRIx64 ".%08" PRIx32 ".honggfuzz.cov",
dir, crc64f, crc64r, (uint32_t)len);
if (files_exists(fname)) {
LOG_D("File '%s' already exists in the output corpus directory '%s'", fname, dir);
return true;
}
LOG_D("Adding file '%s' to the corpus directory '%s'", fname, dir);
if (!files_writeBufToFile(fname, data, len, O_WRONLY | O_CREAT | O_EXCL | O_CLOEXEC)) {
LOG_W("Couldn't write buffer to file '%s'", fname);
return false;
}
return true;
}
static void fuzz_addFileToFileQ(honggfuzz_t* hfuzz, const uint8_t* data, size_t len) {
ATOMIC_SET(hfuzz->timing.lastCovUpdate, time(NULL));
struct dynfile_t* dynfile = (struct dynfile_t*)util_Malloc(sizeof(struct dynfile_t));
dynfile->size = len;
dynfile->data = (uint8_t*)util_Malloc(len);
memcpy(dynfile->data, data, len);
MX_SCOPED_RWLOCK_WRITE(&hfuzz->io.dynfileq_mutex);
TAILQ_INSERT_TAIL(&hfuzz->io.dynfileq, dynfile, pointers);
hfuzz->io.dynfileqCnt++;
if (hfuzz->socketFuzzer.enabled) {
/* Don't add coverage data to files in socketFuzzer mode */
return;
}
if (!fuzz_writeCovFile(hfuzz->io.covDirAll, data, len)) {
LOG_E("Couldn't save the coverage data to '%s'", hfuzz->io.covDirAll);
}
/* No need to add files to the new coverage dir, if this is just the dry-run phase */
if (fuzz_getState(hfuzz) == _HF_STATE_DYNAMIC_DRY_RUN || hfuzz->io.covDirNew == NULL) {
return;
}
if (!fuzz_writeCovFile(hfuzz->io.covDirNew, data, len)) {
LOG_E("Couldn't save the new coverage data to '%s'", hfuzz->io.covDirNew);
}
}
static void fuzz_setDynamicMainState(run_t* run) {
/* All threads need to indicate willingness to switch to the DYNAMIC_MAIN state. Count them! */
static uint32_t cnt = 0;
ATOMIC_PRE_INC(cnt);
static pthread_mutex_t state_mutex = PTHREAD_MUTEX_INITIALIZER;
MX_SCOPED_LOCK(&state_mutex);
if (fuzz_getState(run->global) == _HF_STATE_DYNAMIC_MAIN) {
return;
}
for (;;) {
/* Check if all threads have already reported in for changing state */
if (ATOMIC_GET(cnt) == run->global->threads.threadsMax) {
break;
}
if (fuzz_isTerminating()) {
return;
}
usleep(1000 * 10); /* Check every 10ms */
}
LOG_I("Entering phase 2/2: Dynamic Main");
snprintf(run->origFileName, sizeof(run->origFileName), "[DYNAMIC]");
ATOMIC_SET(run->global->feedback.state, _HF_STATE_DYNAMIC_MAIN);
/*
* If the initial fuzzing yielded no useful coverage, just add a single 1-byte file to the
* dynamic corpus, so the dynamic phase doesn't fail because of lack of useful inputs
*/
if (run->global->io.dynfileqCnt == 0) {
const char* single_byte = run->global->cfg.only_printable ? " " : "\0";
fuzz_addFileToFileQ(run->global, (const uint8_t*)single_byte, 1U);
}
}
static void fuzz_perfFeedback(run_t* run) {
if (run->global->feedback.skipFeedbackOnTimeout && run->tmOutSignaled) {
return;
}
LOG_D("New file size: %zu, Perf feedback new/cur (instr,branch): %" PRIu64 "/%" PRIu64
"/%" PRIu64 "/%" PRIu64 ", BBcnt new/total: %" PRIu64 "/%" PRIu64,
run->dynamicFileSz, run->linux.hwCnts.cpuInstrCnt, run->global->linux.hwCnts.cpuInstrCnt,
run->linux.hwCnts.cpuBranchCnt, run->global->linux.hwCnts.cpuBranchCnt,
run->linux.hwCnts.newBBCnt, run->global->linux.hwCnts.bbCnt);
MX_SCOPED_LOCK(&run->global->feedback.feedback_mutex);
uint64_t softCntPc = 0;
uint64_t softCntEdge = 0;
uint64_t softCntCmp = 0;
if (run->global->feedback.bbFd != -1) {
softCntPc = ATOMIC_GET(run->global->feedback.feedbackMap->pidFeedbackPc[run->fuzzNo]);
ATOMIC_CLEAR(run->global->feedback.feedbackMap->pidFeedbackPc[run->fuzzNo]);
softCntEdge = ATOMIC_GET(run->global->feedback.feedbackMap->pidFeedbackEdge[run->fuzzNo]);
ATOMIC_CLEAR(run->global->feedback.feedbackMap->pidFeedbackEdge[run->fuzzNo]);
softCntCmp = ATOMIC_GET(run->global->feedback.feedbackMap->pidFeedbackCmp[run->fuzzNo]);
ATOMIC_CLEAR(run->global->feedback.feedbackMap->pidFeedbackCmp[run->fuzzNo]);
}
int64_t diff0 = run->global->linux.hwCnts.cpuInstrCnt - run->linux.hwCnts.cpuInstrCnt;
int64_t diff1 = run->global->linux.hwCnts.cpuBranchCnt - run->linux.hwCnts.cpuBranchCnt;
/* Any increase in coverage (edge, pc, cmp, hw) counters forces adding input to the corpus */
if (run->linux.hwCnts.newBBCnt > 0 || softCntPc > 0 || softCntEdge > 0 || softCntCmp > 0 ||
diff0 < 0 || diff1 < 0) {
if (diff0 < 0) {
run->global->linux.hwCnts.cpuInstrCnt = run->linux.hwCnts.cpuInstrCnt;
}
if (diff1 < 0) {
run->global->linux.hwCnts.cpuBranchCnt = run->linux.hwCnts.cpuBranchCnt;
}
run->global->linux.hwCnts.bbCnt += run->linux.hwCnts.newBBCnt;
run->global->linux.hwCnts.softCntPc += softCntPc;
run->global->linux.hwCnts.softCntEdge += softCntEdge;
run->global->linux.hwCnts.softCntCmp += softCntCmp;
LOG_I("Size:%zu (i,b,hw,edge,ip,cmp): %" PRIu64 "/%" PRIu64 "/%" PRIu64 "/%" PRIu64
"/%" PRIu64 "/%" PRIu64 ", Tot:%" PRIu64 "/%" PRIu64 "/%" PRIu64 "/%" PRIu64
"/%" PRIu64 "/%" PRIu64,
run->dynamicFileSz, run->linux.hwCnts.cpuInstrCnt, run->linux.hwCnts.cpuBranchCnt,
run->linux.hwCnts.newBBCnt, softCntEdge, softCntPc, softCntCmp,
run->global->linux.hwCnts.cpuInstrCnt, run->global->linux.hwCnts.cpuBranchCnt,
run->global->linux.hwCnts.bbCnt, run->global->linux.hwCnts.softCntEdge,
run->global->linux.hwCnts.softCntPc, run->global->linux.hwCnts.softCntCmp);
fuzz_addFileToFileQ(run->global, run->dynamicFile, run->dynamicFileSz);
if (run->global->socketFuzzer.enabled) {
LOG_D("SocketFuzzer: fuzz: new BB (perf)");
fuzz_notifySocketFuzzerNewCov(run->global);
}
}
}
/* Return value indicates whether report file should be updated with the current verified crash */
static bool fuzz_runVerifier(run_t* run) {
if (!run->crashFileName[0] || !run->backtrace) {
return false;
}
uint64_t backtrace = run->backtrace;
char origCrashPath[PATH_MAX];
snprintf(origCrashPath, sizeof(origCrashPath), "%s", run->crashFileName);
/* Workspace is inherited, just append a extra suffix */
char verFile[PATH_MAX];
snprintf(verFile, sizeof(verFile), "%s.verified", origCrashPath);
if (files_exists(verFile)) {
LOG_D("Crash file to verify '%s' is already verified as '%s'", origCrashPath, verFile);
return false;
}
for (int i = 0; i < _HF_VERIFIER_ITER; i++) {
LOG_I("Launching verifier for HASH: %" PRIx64 " (iteration: %d out of %d)", run->backtrace,
i + 1, _HF_VERIFIER_ITER);
run->timeStartedMillis = 0;
run->backtrace = 0;
run->access = 0;
run->exception = 0;
run->mainWorker = false;
if (!subproc_Run(run)) {
LOG_F("subproc_Run()");
}
/* If stack hash doesn't match skip name tag and exit */
if (run->backtrace != backtrace) {
LOG_E("Verifier stack mismatch: (original) %" PRIx64 " != (new) %" PRIx64, backtrace,
run->backtrace);
run->backtrace = backtrace;
return true;
}
LOG_I("Verifier for HASH: %" PRIx64 " (iteration: %d, left: %d). MATCH!", run->backtrace,
i + 1, _HF_VERIFIER_ITER - i - 1);
}
/* Copy file with new suffix & remove original copy */
int fd = TEMP_FAILURE_RETRY(open(verFile, O_CREAT | O_EXCL | O_WRONLY, 0600));
if (fd == -1 && errno == EEXIST) {
LOG_I("It seems that '%s' already exists, skipping", verFile);
return false;
}
if (fd == -1) {
PLOG_E("Couldn't create '%s'", verFile);
return true;
}
defer {
close(fd);
};
if (!files_writeToFd(fd, run->dynamicFile, run->dynamicFileSz)) {
LOG_E("Couldn't save verified file as '%s'", verFile);
unlink(verFile);
return true;
}
LOG_I("Verified crash for HASH: %" PRIx64 " and saved it as '%s'", backtrace, verFile);
ATOMIC_POST_INC(run->global->cnts.verifiedCrashesCnt);
return true;
}
static bool fuzz_fetchInput(run_t* run) {
if (fuzz_getState(run->global) == _HF_STATE_DYNAMIC_DRY_RUN) {
run->mutationsPerRun = 0U;
if (input_prepareStaticFile(run, /* rewind= */ false)) {
return true;
}
fuzz_setDynamicMainState(run);
run->mutationsPerRun = run->global->mutate.mutationsPerRun;
}
if (fuzz_getState(run->global) == _HF_STATE_DYNAMIC_MAIN) {
if (run->global->exe.externalCommand) {
if (!input_prepareExternalFile(run)) {
LOG_E("input_prepareFileExternally() failed");
return false;
}
} else if (!input_prepareDynamicInput(run)) {
LOG_E("input_prepareFileDynamically() failed");
return false;
}
}
if (fuzz_getState(run->global) == _HF_STATE_STATIC) {
if (run->global->exe.externalCommand) {
if (!input_prepareExternalFile(run)) {
LOG_E("input_prepareFileExternally() failed");
return false;
}
} else if (!input_prepareStaticFile(run, true /* rewind */)) {
LOG_E("input_prepareFile() failed");
return false;
}
}
if (run->global->exe.postExternalCommand && !input_postProcessFile(run)) {
LOG_E("input_postProcessFile() failed");
return false;
}
return true;
}
static void fuzz_fuzzLoop(run_t* run) {
run->pid = 0;
run->timeStartedMillis = 0;
run->crashFileName[0] = '\0';
run->pc = 0;
run->backtrace = 0;
run->access = 0;
run->exception = 0;
run->report[0] = '\0';
run->mainWorker = true;
run->mutationsPerRun = run->global->mutate.mutationsPerRun;
run->dynamicFileSz = 0;
run->dynamicFileCopyFd = -1,
run->linux.hwCnts.cpuInstrCnt = 0;
run->linux.hwCnts.cpuBranchCnt = 0;
run->linux.hwCnts.bbCnt = 0;
run->linux.hwCnts.newBBCnt = 0;
if (!fuzz_fetchInput(run)) {
LOG_F("Cound't prepare input for fuzzing");
}
if (!subproc_Run(run)) {
LOG_F("Couldn't run fuzzed command");
}
if (run->global->feedback.dynFileMethod != _HF_DYNFILE_NONE) {
fuzz_perfFeedback(run);
}
if (run->global->cfg.useVerifier && !fuzz_runVerifier(run)) {
return;
}
report_Report(run);
}
static void fuzz_fuzzLoopSocket(run_t* run) {
run->pid = 0;
run->timeStartedMillis = 0;
run->crashFileName[0] = '\0';
run->pc = 0;
run->backtrace = 0;
run->access = 0;
run->exception = 0;
run->report[0] = '\0';
run->mainWorker = true;
run->mutationsPerRun = run->global->mutate.mutationsPerRun;
run->dynamicFileSz = 0;
run->dynamicFileCopyFd = -1,
run->linux.hwCnts.cpuInstrCnt = 0;
run->linux.hwCnts.cpuBranchCnt = 0;
run->linux.hwCnts.bbCnt = 0;
run->linux.hwCnts.newBBCnt = 0;
LOG_I("------------------------------------------------------");
/* First iteration: Start target
Other iterations: re-start target, if necessary
subproc_Run() will decide by itself if a restart is necessary, via
subproc_New()
*/
LOG_D("------[ 1: subproc_run");
if (!subproc_Run(run)) {
LOG_W("Couldn't run server");
}
/* Tell the external fuzzer to send data to target
The fuzzer will notify us when finished; block until then.
*/
LOG_D("------[ 2: fetch input");
if (!fuzz_waitForExternalInput(run)) {
/* Fuzzer could not connect to target, and told us to
restart it. Do it on the next iteration. */
LOG_D("------[ 2.1: Target down, will restart it");
run->hasCrashed = true;
return;
}
LOG_D("------[ 3: feedback");
if (run->global->feedback.dynFileMethod != _HF_DYNFILE_NONE) {
fuzz_perfFeedback(run);
}
if (run->global->cfg.useVerifier && !fuzz_runVerifier(run)) {
return;
}
report_Report(run);
}
static void* fuzz_threadNew(void* arg) {
honggfuzz_t* hfuzz = (honggfuzz_t*)arg;
unsigned int fuzzNo = ATOMIC_POST_INC(hfuzz->threads.threadsActiveCnt);
LOG_I("Launched new fuzzing thread, no. #%" PRId32, fuzzNo);
run_t run = {
.global = hfuzz,
.pid = 0,
.persistentPid = 0,
.dynfileqCurrent = NULL,
.dynamicFile = NULL,
.dynamicFileFd = -1,
.fuzzNo = fuzzNo,
.persistentSock = -1,
.tmOutSignaled = false,
.origFileName = "[DYNAMIC]",
.linux.attachedPid = 0,
.netbsd.attachedPid = 0,
};
/* Do not try to handle input files with socketfuzzer */
if (!hfuzz->socketFuzzer.enabled) {
if (!(run.dynamicFile = files_mapSharedMem(hfuzz->mutate.maxFileSz, &run.dynamicFileFd,
"hfuzz-input", run.global->io.workDir))) {
LOG_F("Couldn't create an input file of size: %zu", hfuzz->mutate.maxFileSz);
}
}
defer {
if (run.dynamicFileFd != -1) {
close(run.dynamicFileFd);
}
};
if (!arch_archThreadInit(&run)) {
LOG_F("Could not initialize the thread");
}
for (;;) {
/* Check if dry run mode with verifier enabled */
if (run.global->mutate.mutationsPerRun == 0U && run.global->cfg.useVerifier &&
!hfuzz->socketFuzzer.enabled) {
if (ATOMIC_POST_INC(run.global->cnts.mutationsCnt) >= run.global->io.fileCnt) {
ATOMIC_POST_INC(run.global->threads.threadsFinished);
break;
}
}
/* Check for max iterations limit if set */
else if ((ATOMIC_POST_INC(run.global->cnts.mutationsCnt) >=
run.global->mutate.mutationsMax) &&
run.global->mutate.mutationsMax) {
ATOMIC_POST_INC(run.global->threads.threadsFinished);
break;
}
input_setSize(&run, run.global->mutate.maxFileSz);
if (hfuzz->socketFuzzer.enabled) {
fuzz_fuzzLoopSocket(&run);
} else {
fuzz_fuzzLoop(&run);
}
if (fuzz_isTerminating()) {
break;
}
if (run.global->cfg.exitUponCrash && ATOMIC_GET(run.global->cnts.crashesCnt) > 0) {
LOG_I("Seen a crash. Terminating all fuzzing threads");
fuzz_setTerminating();
break;
}
}
LOG_I("Terminating thread no. #%" PRId32 ", left: %zu", fuzzNo,
hfuzz->threads.threadsMax - run.global->threads.threadsFinished);
ATOMIC_POST_INC(run.global->threads.threadsFinished);
pthread_kill(run.global->threads.mainThread, SIGALRM);
return NULL;
}
static void fuzz_runThread(honggfuzz_t* hfuzz, pthread_t* thread, void* (*thread_func)(void*)) {
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
pthread_attr_setstacksize(&attr, _HF_PTHREAD_STACKSIZE);
pthread_attr_setguardsize(&attr, (size_t)sysconf(_SC_PAGESIZE));
if (pthread_create(thread, &attr, thread_func, (void*)hfuzz) < 0) {
PLOG_F("Couldn't create a new thread");
}
pthread_attr_destroy(&attr);
return;
}
void fuzz_threadsStart(honggfuzz_t* hfuzz, pthread_t* threads) {
if (!arch_archInit(hfuzz)) {
LOG_F("Couldn't prepare arch for fuzzing");
}
if (!sanitizers_Init(hfuzz)) {
LOG_F("Couldn't prepare sanitizer options");
}
mangle_init(hfuzz->cfg.only_printable);
if (hfuzz->socketFuzzer.enabled) {
/* Don't do dry run with socketFuzzer */
LOG_I("Entering phase - Feedback Driven Mode (SocketFuzzer)");
hfuzz->feedback.state = _HF_STATE_DYNAMIC_MAIN;
} else if (hfuzz->feedback.dynFileMethod != _HF_DYNFILE_NONE) {
LOG_I("Entering phase 1/2: Dry Run");
hfuzz->feedback.state = _HF_STATE_DYNAMIC_DRY_RUN;
} else {
LOG_I("Entering phase: Static");
hfuzz->feedback.state = _HF_STATE_STATIC;
}
for (size_t i = 0; i < hfuzz->threads.threadsMax; i++) {
fuzz_runThread(hfuzz, &threads[i], fuzz_threadNew);
}
}
void fuzz_threadsStop(honggfuzz_t* hfuzz, pthread_t* threads) {
for (size_t i = 0; i < hfuzz->threads.threadsMax; i++) {
void* retval;
if (pthread_join(threads[i], &retval) != 0) {
PLOG_F("Couldn't pthread_join() thread: %zu", i);
}
}
LOG_I("All threads done");
}