-
Notifications
You must be signed in to change notification settings - Fork 1.2k
/
fuzzer.go
367 lines (334 loc) · 10.7 KB
/
fuzzer.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
// Copyright 2015 syzkaller project authors. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
package main
import (
"flag"
"fmt"
"net/http"
_ "net/http/pprof"
"os"
"path/filepath"
"runtime"
"runtime/debug"
"sync"
"sync/atomic"
"time"
"github.com/google/syzkaller/pkg/flatrpc"
"github.com/google/syzkaller/pkg/host"
"github.com/google/syzkaller/pkg/ipc"
"github.com/google/syzkaller/pkg/ipc/ipcconfig"
"github.com/google/syzkaller/pkg/log"
"github.com/google/syzkaller/pkg/osutil"
"github.com/google/syzkaller/pkg/rpctype"
"github.com/google/syzkaller/pkg/signal"
"github.com/google/syzkaller/pkg/tool"
"github.com/google/syzkaller/prog"
_ "github.com/google/syzkaller/sys"
"github.com/google/syzkaller/sys/targets"
)
type FuzzerTool struct {
name string
executor string
gate *ipc.Gate
manager *rpctype.RPCClient
// TODO: repair triagedCandidates logic, it's broken now.
triagedCandidates uint32
timeouts targets.Timeouts
leakFrames []string
noExecRequests atomic.Uint64
noExecDuration atomic.Uint64
requests chan rpctype.ExecutionRequest
results chan executionResult
signalMu sync.RWMutex
maxSignal signal.Signal
}
// executionResult offloads some computations from the proc loop
// to the communication thread.
type executionResult struct {
rpctype.ExecutionRequest
procID int
try int
info *ipc.ProgInfo
output []byte
err string
}
// Gate size controls how deep in the log the last executed by every proc
// program may be. The intent is to make sure that, given the output log,
// we always understand what was happening.
// Judging by the logs collected on syzbot, 32 should be a reasonable figure.
// It coincides with prog.MaxPids.
const gateSize = prog.MaxPids
// TODO: split into smaller methods.
// nolint: funlen, gocyclo
func main() {
debug.SetGCPercent(50)
var (
flagName = flag.String("name", "test", "unique name for manager")
flagOS = flag.String("os", runtime.GOOS, "target OS")
flagArch = flag.String("arch", runtime.GOARCH, "target arch")
flagManager = flag.String("manager", "", "manager rpc address")
flagProcs = flag.Int("procs", 1, "number of parallel test processes")
flagTest = flag.Bool("test", false, "enable image testing mode") // used by syz-ci
flagPprofPort = flag.Int("pprof_port", 0, "HTTP port for the pprof endpoint (disabled if 0)")
)
defer tool.Init()()
log.Logf(0, "fuzzer started")
target, err := prog.GetTarget(*flagOS, *flagArch)
if err != nil {
log.SyzFatal(err)
}
config, execOpts, err := ipcconfig.Default(target)
if err != nil {
log.SyzFatalf("failed to create default ipc config: %v", err)
}
timeouts := config.Timeouts
executor := config.Executor
shutdown := make(chan struct{})
osutil.HandleInterrupts(shutdown)
go func() {
// Handles graceful preemption on GCE.
<-shutdown
log.Logf(0, "SYZ-FUZZER: PREEMPTED")
os.Exit(1)
}()
if *flagPprofPort != 0 {
setupPprofHandler(*flagPprofPort)
}
if *flagTest {
checkArgs := &checkArgs{
target: target,
sandbox: ipc.FlagsToSandbox(execOpts.EnvFlags),
ipcConfig: config,
ipcExecOpts: execOpts,
gitRevision: prog.GitRevision,
targetRevision: target.Revision,
}
testImage(*flagManager, checkArgs)
return
}
log.Logf(0, "dialing manager at %v", *flagManager)
manager, err := rpctype.NewRPCClient(*flagManager)
if err != nil {
log.SyzFatalf("failed to create an RPC client: %v ", err)
}
log.Logf(1, "connecting to manager...")
a := &rpctype.ConnectArgs{
Name: *flagName,
GitRevision: prog.GitRevision,
SyzRevision: target.Revision,
}
a.ExecutorArch, a.ExecutorSyzRevision, a.ExecutorGitRevision, err = executorVersion(executor)
if err != nil {
log.SyzFatalf("failed to run executor version: %v ", err)
}
r := &rpctype.ConnectRes{}
if err := manager.Call("Manager.Connect", a, r); err != nil {
log.SyzFatalf("failed to call Manager.Connect(): %v ", err)
}
checkReq := &rpctype.CheckArgs{
Name: *flagName,
Files: host.ReadFiles(r.ReadFiles),
Globs: make(map[string][]string),
}
features, err := host.SetupFeatures(target, executor, r.Features, nil)
if err != nil {
log.SyzFatalf("failed to setup features: %v ", err)
}
checkReq.Features = features
for _, glob := range r.ReadGlobs {
files, err := filepath.Glob(filepath.FromSlash(glob))
if err != nil && checkReq.Error == "" {
checkReq.Error = fmt.Sprintf("failed to read glob %q: %v", glob, err)
}
checkReq.Globs[glob] = files
}
checkRes := new(rpctype.CheckRes)
if err := manager.Call("Manager.Check", checkReq, checkRes); err != nil {
log.SyzFatalf("Manager.Check call failed: %v", err)
}
if checkReq.Error != "" {
log.SyzFatalf("%v", checkReq.Error)
}
if checkRes.CoverFilterBitmap != nil {
if err := osutil.WriteFile("syz-cover-bitmap", checkRes.CoverFilterBitmap); err != nil {
log.SyzFatalf("failed to write syz-cover-bitmap: %v", err)
}
}
inputsCount := *flagProcs * 2
fuzzerTool := &FuzzerTool{
name: *flagName,
executor: executor,
manager: manager,
timeouts: timeouts,
leakFrames: r.MemoryLeakFrames,
requests: make(chan rpctype.ExecutionRequest, 2*inputsCount),
results: make(chan executionResult, 2*inputsCount),
}
fuzzerTool.filterDataRaceFrames(r.DataRaceFrames)
var gateCallback func()
for _, feat := range features {
if feat.Id == flatrpc.FeatureLeak && feat.Reason == "" {
gateCallback = fuzzerTool.leakGateCallback
}
}
fuzzerTool.gate = ipc.NewGate(gateSize, gateCallback)
log.Logf(0, "starting %v executor processes", *flagProcs)
for pid := 0; pid < *flagProcs; pid++ {
startProc(fuzzerTool, pid, config)
}
// Query enough inputs at the beginning.
fuzzerTool.exchangeDataCall(nil, 0)
go fuzzerTool.exchangeDataWorker()
fuzzerTool.exchangeDataWorker()
}
func (tool *FuzzerTool) leakGateCallback() {
// Leak checking is very slow so we don't do it while triaging the corpus
// (otherwise it takes infinity). When we have presumably triaged the corpus
// (triagedCandidates == 1), we run leak checking bug ignore the result
// to flush any previous leaks. After that (triagedCandidates == 2)
// we do actual leak checking and report leaks.
triagedCandidates := atomic.LoadUint32(&tool.triagedCandidates)
if triagedCandidates == 0 {
return
}
args := append([]string{"leak"}, tool.leakFrames...)
timeout := tool.timeouts.NoOutput * 9 / 10
output, err := osutil.RunCmd(timeout, "", tool.executor, args...)
if err != nil && triagedCandidates == 2 {
// If we exit right away, dying executors will dump lots of garbage to console.
os.Stdout.Write(output)
fmt.Printf("BUG: leak checking failed\n")
time.Sleep(time.Hour)
os.Exit(1)
}
if triagedCandidates == 1 {
atomic.StoreUint32(&tool.triagedCandidates, 2)
}
}
func (tool *FuzzerTool) filterDataRaceFrames(frames []string) {
if len(frames) == 0 {
return
}
args := append([]string{"setup_kcsan_filterlist"}, frames...)
timeout := time.Minute * tool.timeouts.Scale
output, err := osutil.RunCmd(timeout, "", tool.executor, args...)
if err != nil {
log.SyzFatalf("failed to set KCSAN filterlist: %v", err)
}
log.Logf(0, "%s", output)
}
func (tool *FuzzerTool) startExecutingCall(progID int64, pid, try int) {
tool.manager.AsyncCall("Manager.StartExecuting", &rpctype.ExecutingRequest{
Name: tool.name,
ID: progID,
ProcID: pid,
Try: try,
})
}
func (tool *FuzzerTool) exchangeDataCall(results []rpctype.ExecutionResult, latency time.Duration) time.Duration {
needProgs := max(0, cap(tool.requests)/2-len(tool.requests))
a := &rpctype.ExchangeInfoRequest{
Name: tool.name,
NeedProgs: needProgs,
Results: results,
StatsDelta: tool.grabStats(),
Latency: latency,
}
r := &rpctype.ExchangeInfoReply{}
start := osutil.MonotonicNano()
if err := tool.manager.Call("Manager.ExchangeInfo", a, r); err != nil {
log.SyzFatalf("Manager.ExchangeInfo call failed: %v", err)
}
latency = osutil.MonotonicNano() - start
tool.updateMaxSignal(r.NewMaxSignal, r.DropMaxSignal)
if len(r.Requests) == 0 {
// This is possible during initial checking stage, backoff a bit.
time.Sleep(100 * time.Millisecond)
}
for _, req := range r.Requests {
tool.requests <- req
}
return latency
}
func (tool *FuzzerTool) exchangeDataWorker() {
var latency time.Duration
ticker := time.NewTicker(3 * time.Second * tool.timeouts.Scale).C
for {
var results []rpctype.ExecutionResult
select {
case res := <-tool.results:
results = append(results, tool.convertExecutionResult(res))
case <-ticker:
// This is not expected to happen a lot,
// but this is required to resolve potential deadlock
// during initial checking stage when we may get
// no test requests from the host in some requests.
}
// Grab other finished calls, just in case there are any.
loop:
for {
select {
case res := <-tool.results:
results = append(results, tool.convertExecutionResult(res))
default:
break loop
}
}
// Replenish exactly the finished requests.
latency = tool.exchangeDataCall(results, latency)
}
}
func (tool *FuzzerTool) convertExecutionResult(res executionResult) rpctype.ExecutionResult {
ret := rpctype.ExecutionResult{
ID: res.ID,
ProcID: res.procID,
Try: res.try,
Output: res.output,
Error: res.err,
}
if res.info != nil {
if res.NewSignal {
tool.diffMaxSignal(res.info, res.SignalFilter, res.SignalFilterCall)
}
ret.Info = *res.info
}
return ret
}
func (tool *FuzzerTool) grabStats() map[string]uint64 {
return map[string]uint64{
"no exec requests": tool.noExecRequests.Swap(0),
"no exec duration": tool.noExecDuration.Swap(0),
}
}
func (tool *FuzzerTool) diffMaxSignal(info *ipc.ProgInfo, mask signal.Signal, maskCall int) {
tool.signalMu.RLock()
defer tool.signalMu.RUnlock()
diffMaxSignal(info, tool.maxSignal, mask, maskCall)
}
func diffMaxSignal(info *ipc.ProgInfo, max, mask signal.Signal, maskCall int) {
info.Extra.Signal = diffCallSignal(info.Extra.Signal, max, mask, -1, maskCall)
for i := 0; i < len(info.Calls); i++ {
info.Calls[i].Signal = diffCallSignal(info.Calls[i].Signal, max, mask, i, maskCall)
}
}
func diffCallSignal(raw []uint32, max, mask signal.Signal, call, maskCall int) []uint32 {
if mask != nil && call == maskCall {
return signal.FilterRaw(raw, max, mask)
}
return max.DiffFromRaw(raw)
}
func (tool *FuzzerTool) updateMaxSignal(add, drop []uint32) {
tool.signalMu.Lock()
defer tool.signalMu.Unlock()
tool.maxSignal.Subtract(signal.FromRaw(drop, 0))
tool.maxSignal.Merge(signal.FromRaw(add, 0))
}
func setupPprofHandler(port int) {
// Necessary for pprof handlers.
go func() {
err := http.ListenAndServe(fmt.Sprintf("0.0.0.0:%v", port), nil)
if err != nil {
log.SyzFatalf("failed to setup a server: %v", err)
}
}()
}