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
|
// 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 vm provides an abstract test machine (VM, physical machine, etc)
// interface for the rest of the system.
// For convenience test machines are subsequently collectively called VMs.
// Package wraps vmimpl package interface with some common functionality
// and higher-level interface.
package vm
import (
"bytes"
"fmt"
"os"
"regexp"
"time"
"github.com/google/syzkaller/pkg/fileutil"
"github.com/google/syzkaller/report"
"github.com/google/syzkaller/vm/vmimpl"
_ "github.com/google/syzkaller/vm/adb"
_ "github.com/google/syzkaller/vm/gce"
_ "github.com/google/syzkaller/vm/kvm"
_ "github.com/google/syzkaller/vm/odroid"
_ "github.com/google/syzkaller/vm/qemu"
)
type Pool struct {
impl vmimpl.Pool
workdir string
}
type Instance struct {
impl vmimpl.Instance
workdir string
index int
}
type Env vmimpl.Env
var (
Shutdown = vmimpl.Shutdown
TimeoutErr = vmimpl.TimeoutErr
)
func Create(typ string, env *Env) (*Pool, error) {
impl, err := vmimpl.Create(typ, (*vmimpl.Env)(env))
if err != nil {
return nil, err
}
return &Pool{
impl: impl,
workdir: env.Workdir,
}, nil
}
func (pool *Pool) Count() int {
return pool.impl.Count()
}
func (pool *Pool) Create(index int) (*Instance, error) {
if index < 0 || index >= pool.Count() {
return nil, fmt.Errorf("invalid VM index %v (count %v)", index, pool.Count())
}
workdir, err := fileutil.ProcessTempDir(pool.workdir)
if err != nil {
return nil, fmt.Errorf("failed to create instance temp dir: %v", err)
}
impl, err := pool.impl.Create(workdir, index)
if err != nil {
os.RemoveAll(workdir)
return nil, err
}
return &Instance{
impl: impl,
workdir: workdir,
index: index,
}, nil
}
func (inst *Instance) Copy(hostSrc string) (string, error) {
return inst.impl.Copy(hostSrc)
}
func (inst *Instance) Forward(port int) (string, error) {
return inst.impl.Forward(port)
}
func (inst *Instance) Run(timeout time.Duration, stop <-chan bool, command string) (outc <-chan []byte, errc <-chan error, err error) {
return inst.impl.Run(timeout, stop, command)
}
func (inst *Instance) Close() {
inst.impl.Close()
os.RemoveAll(inst.workdir)
}
func MonitorExecution(outc <-chan []byte, errc <-chan error, needOutput bool, ignores []*regexp.Regexp) (desc string, text, output []byte, crashed, timedout bool) {
waitForOutput := func() {
dur := time.Second
if needOutput {
dur = 10 * time.Second
}
timer := time.NewTimer(dur).C
for {
select {
case out, ok := <-outc:
if !ok {
return
}
output = append(output, out...)
case <-timer:
return
}
}
}
matchPos := 0
const (
beforeContext = 256 << 10
afterContext = 128 << 10
)
extractError := func(defaultError string) (string, []byte, []byte, bool, bool) {
// Give it some time to finish writing the error message.
waitForOutput()
if bytes.Contains(output, []byte("SYZ-FUZZER: PREEMPTED")) {
return "preempted", nil, nil, false, true
}
if !report.ContainsCrash(output[matchPos:], ignores) {
return defaultError, nil, output, defaultError != "", false
}
desc, text, start, end := report.Parse(output[matchPos:], ignores)
start = start + matchPos - beforeContext
if start < 0 {
start = 0
}
end = end + matchPos + afterContext
if end > len(output) {
end = len(output)
}
return desc, text, output[start:end], true, false
}
lastExecuteTime := time.Now()
ticker := time.NewTimer(3 * time.Minute)
tickerFired := false
for {
if !tickerFired && !ticker.Stop() {
<-ticker.C
}
tickerFired = false
ticker.Reset(3 * time.Minute)
select {
case err := <-errc:
switch err {
case nil:
// The program has exited without errors,
// but wait for kernel output in case there is some delayed oops.
return extractError("")
case TimeoutErr:
return err.Error(), nil, nil, false, true
default:
// Note: connection lost can race with a kernel oops message.
// In such case we want to return the kernel oops.
return extractError("lost connection to test machine")
}
case out := <-outc:
output = append(output, out...)
if bytes.Index(output[matchPos:], []byte("executing program")) != -1 { // syz-fuzzer output
lastExecuteTime = time.Now()
}
if bytes.Index(output[matchPos:], []byte("executed programs:")) != -1 { // syz-execprog output
lastExecuteTime = time.Now()
}
if report.ContainsCrash(output[matchPos:], ignores) {
return extractError("unknown error")
}
if len(output) > 2*beforeContext {
copy(output, output[len(output)-beforeContext:])
output = output[:beforeContext]
}
matchPos = len(output) - 128
if matchPos < 0 {
matchPos = 0
}
// In some cases kernel constantly prints something to console,
// but fuzzer is not actually executing programs.
if time.Since(lastExecuteTime) > 3*time.Minute {
return "test machine is not executing programs", nil, output, true, false
}
case <-ticker.C:
tickerFired = true
return "no output from test machine", nil, output, true, false
case <-Shutdown:
return "", nil, nil, false, false
}
}
}
|
