aboutsummaryrefslogtreecommitdiffstats
path: root/sys/linux/init_vusb.go
blob: 998aa9ff7ea574313576338b0cd9e97884bafb81 (plain)
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
// Copyright 2019 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 linux

import (
	"encoding/binary"
	"fmt"
	"strings"

	"github.com/google/syzkaller/prog"
)

const (
	USB_DEVICE_ID_MATCH_VENDOR = 1 << iota
	USB_DEVICE_ID_MATCH_PRODUCT
	USB_DEVICE_ID_MATCH_DEV_LO
	USB_DEVICE_ID_MATCH_DEV_HI
	USB_DEVICE_ID_MATCH_DEV_CLASS
	USB_DEVICE_ID_MATCH_DEV_SUBCLASS
	USB_DEVICE_ID_MATCH_DEV_PROTOCOL
	USB_DEVICE_ID_MATCH_INT_CLASS
	USB_DEVICE_ID_MATCH_INT_SUBCLASS
	USB_DEVICE_ID_MATCH_INT_PROTOCOL
	USB_DEVICE_ID_MATCH_INT_NUMBER

	BytesPerUsbID = 17
	BytesPerHidID = 12
)

type UsbDeviceID struct {
	MatchFlags         uint16
	IDVendor           uint16
	IDProduct          uint16
	BcdDeviceLo        uint16
	BcdDeviceHi        uint16
	BDeviceClass       uint8
	BDeviceSubClass    uint8
	BDeviceProtocol    uint8
	BInterfaceClass    uint8
	BInterfaceSubClass uint8
	BInterfaceProtocol uint8
	BInterfaceNumber   uint8
}

type HidDeviceID struct {
	Bus     uint16
	Group   uint16
	Vendor  uint32
	Product uint32
}

func (arch *arch) generateUsbDeviceDescriptor(g *prog.Gen, typ0 prog.Type, dir prog.Dir, old prog.Arg) (
	arg prog.Arg, calls []*prog.Call) {
	if old == nil {
		arg = g.GenerateSpecialArg(typ0, dir, &calls)
	} else {
		arg = prog.CloneArg(old)
		calls = g.MutateArg(arg)
	}
	if g.Target().ArgContainsAny(arg) {
		return
	}

	patchUsbDeviceID(g, &arg, calls, usbIdsAll, true)

	return
}

func (arch *arch) generateUsbPrinterDeviceDescriptor(g *prog.Gen, typ0 prog.Type, dir prog.Dir, old prog.Arg) (
	arg prog.Arg, calls []*prog.Call) {
	if old == nil {
		arg = g.GenerateSpecialArg(typ0, dir, &calls)
	} else {
		arg = prog.CloneArg(old)
		calls = g.MutateArg(arg)
	}
	if g.Target().ArgContainsAny(arg) {
		return
	}

	// Roll the dice to decide if and how we want to patch printer USB IDs.
	switch {
	case g.Rand().Intn(3) == 0:
		// Syzlang descriptions already contain passable IDs, leave them as is.
		return
	case g.Rand().Intn(2) == 0:
		// Patch in quirk IDs that are hardcoded in the USB printer class driver
		// (and thus are not auto-extractable) to allow exercising driver quirks;
		// see quirk_printers in drivers/usb/class/usblp.c.
		var idVendor int16
		var idProduct int16
		if g.Rand().Intn(2) == 0 { // USBLP_QUIRK_BIDIR
			idVendor = 0x03f0
			idProduct = 0x0004
		} else { // USBLP_QUIRK_BAD_CLASS
			idVendor = 0x04b8
			idProduct = 0x0202
		}
		devArg := arg.(*prog.GroupArg).Inner[0]
		patchGroupArg(devArg, 7, "idVendor", uint64(idVendor))
		patchGroupArg(devArg, 8, "idProduct", uint64(idProduct))
	default:
		// Patch in IDs auto-extracted from the matching rules for the USB printer class.
		// Do not patch IDs that are not used in the matching rules to avoid subverting
		// the kernel into matching the device to a different driver.
		if ids, ok := usbIds["usblp"]; ok {
			patchUsbDeviceID(g, &arg, calls, ids, false)
		}
	}

	return
}

func patchUsbDeviceID(g *prog.Gen, arg *prog.Arg, calls []*prog.Call, ids string, patchNonMatching bool) {
	id := randUsbDeviceID(g, ids, patchNonMatching)

	devArg := (*arg).(*prog.GroupArg).Inner[0]
	if (id.MatchFlags&USB_DEVICE_ID_MATCH_VENDOR) != 0 || patchNonMatching {
		patchGroupArg(devArg, 7, "idVendor", uint64(id.IDVendor))
	}
	if (id.MatchFlags&USB_DEVICE_ID_MATCH_PRODUCT) != 0 || patchNonMatching {
		patchGroupArg(devArg, 8, "idProduct", uint64(id.IDProduct))
	}
	if (id.MatchFlags&USB_DEVICE_ID_MATCH_DEV_LO) != 0 ||
		(id.MatchFlags&USB_DEVICE_ID_MATCH_DEV_HI) != 0 || patchNonMatching {
		bcdDevice := id.BcdDeviceLo + uint16(g.Rand().Intn(int(id.BcdDeviceHi-id.BcdDeviceLo)+1))
		patchGroupArg(devArg, 9, "bcdDevice", uint64(bcdDevice))
	}
	if (id.MatchFlags&USB_DEVICE_ID_MATCH_DEV_CLASS) != 0 || patchNonMatching {
		patchGroupArg(devArg, 3, "bDeviceClass", uint64(id.BDeviceClass))
	}
	if (id.MatchFlags&USB_DEVICE_ID_MATCH_DEV_SUBCLASS) != 0 || patchNonMatching {
		patchGroupArg(devArg, 4, "bDeviceSubClass", uint64(id.BDeviceSubClass))
	}
	if (id.MatchFlags&USB_DEVICE_ID_MATCH_DEV_PROTOCOL) != 0 || patchNonMatching {
		patchGroupArg(devArg, 5, "bDeviceProtocol", uint64(id.BDeviceProtocol))
	}

	configArg := devArg.(*prog.GroupArg).Inner[14].(*prog.GroupArg).Inner[0].(*prog.GroupArg).Inner[0]
	interfacesArg := configArg.(*prog.GroupArg).Inner[8]

	for i, interfaceArg := range interfacesArg.(*prog.GroupArg).Inner {
		interfaceArg = interfaceArg.(*prog.GroupArg).Inner[0]
		if i > 0 {
			// Generate new IDs for every interface after the first one.
			id = randUsbDeviceID(g, ids, patchNonMatching)
		}
		if (id.MatchFlags&USB_DEVICE_ID_MATCH_DEV_CLASS) != 0 || patchNonMatching {
			patchGroupArg(interfaceArg, 5, "bInterfaceClass", uint64(id.BInterfaceClass))
		}
		if (id.MatchFlags&USB_DEVICE_ID_MATCH_DEV_SUBCLASS) != 0 || patchNonMatching {
			patchGroupArg(interfaceArg, 6, "bInterfaceSubClass", uint64(id.BInterfaceSubClass))
		}
		if (id.MatchFlags&USB_DEVICE_ID_MATCH_DEV_PROTOCOL) != 0 || patchNonMatching {
			patchGroupArg(interfaceArg, 7, "bInterfaceProtocol", uint64(id.BInterfaceProtocol))
		}
		if (id.MatchFlags&USB_DEVICE_ID_MATCH_INT_NUMBER) != 0 || patchNonMatching {
			patchGroupArg(interfaceArg, 2, "bInterfaceNumber", uint64(id.BInterfaceNumber))
		}
	}
}

func randUsbDeviceID(g *prog.Gen, ids string, patchNonMatching bool) UsbDeviceID {
	totalIds := len(ids) / BytesPerUsbID
	idNum := g.Rand().Intn(totalIds)
	base := ids[idNum*BytesPerUsbID : (idNum+1)*BytesPerUsbID]

	p := strings.NewReader(base)
	var id UsbDeviceID
	if binary.Read(p, binary.LittleEndian, &id) != nil {
		panic("not enough data to read")
	}

	// Don't generate values for IDs that won't be patched in.
	if !patchNonMatching {
		return id
	}

	if (id.MatchFlags & USB_DEVICE_ID_MATCH_VENDOR) == 0 {
		id.IDVendor = uint16(g.Rand().Intn(0xffff + 1))
	}
	if (id.MatchFlags & USB_DEVICE_ID_MATCH_PRODUCT) == 0 {
		id.IDProduct = uint16(g.Rand().Intn(0xffff + 1))
	}
	if (id.MatchFlags & USB_DEVICE_ID_MATCH_DEV_LO) == 0 {
		id.BcdDeviceLo = 0x0
	}
	if (id.MatchFlags & USB_DEVICE_ID_MATCH_DEV_HI) == 0 {
		id.BcdDeviceHi = 0xffff
	}
	if (id.MatchFlags & USB_DEVICE_ID_MATCH_DEV_CLASS) == 0 {
		id.BDeviceClass = uint8(g.Rand().Intn(0xff + 1))
	}
	if (id.MatchFlags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) == 0 {
		id.BDeviceSubClass = uint8(g.Rand().Intn(0xff + 1))
	}
	if (id.MatchFlags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) == 0 {
		id.BDeviceProtocol = uint8(g.Rand().Intn(0xff + 1))
	}
	if (id.MatchFlags & USB_DEVICE_ID_MATCH_INT_CLASS) == 0 {
		id.BInterfaceClass = uint8(g.Rand().Intn(0xff + 1))
	}
	if (id.MatchFlags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) == 0 {
		id.BInterfaceSubClass = uint8(g.Rand().Intn(0xff + 1))
	}
	if (id.MatchFlags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) == 0 {
		id.BInterfaceProtocol = uint8(g.Rand().Intn(0xff + 1))
	}
	if (id.MatchFlags & USB_DEVICE_ID_MATCH_INT_NUMBER) == 0 {
		id.BInterfaceNumber = uint8(g.Rand().Intn(0xff + 1))
	}

	return id
}

func (arch *arch) generateUsbHidDeviceDescriptor(g *prog.Gen, typ0 prog.Type, dir prog.Dir, old prog.Arg) (
	arg prog.Arg, calls []*prog.Call) {
	if old == nil {
		arg = g.GenerateSpecialArg(typ0, dir, &calls)
	} else {
		arg = prog.CloneArg(old)
		calls = g.MutateArg(arg)
	}
	if g.Target().ArgContainsAny(arg) {
		return
	}

	totalIds := len(hidIdsAll) / BytesPerHidID
	idNum := g.Rand().Intn(totalIds)
	base := hidIdsAll[idNum*BytesPerHidID : (idNum+1)*BytesPerHidID]

	p := strings.NewReader(base)
	var id HidDeviceID
	if binary.Read(p, binary.LittleEndian, &id) != nil {
		panic("not enough data to read")
	}

	devArg := arg.(*prog.GroupArg).Inner[0]
	patchGroupArg(devArg, 7, "idVendor", uint64(id.Vendor))
	patchGroupArg(devArg, 8, "idProduct", uint64(id.Product))

	return
}

func patchGroupArg(arg prog.Arg, index int, field string, value uint64) {
	a := arg.(*prog.GroupArg)
	typ := a.Type().(*prog.StructType)
	if field != typ.Fields[index].Name {
		panic(fmt.Sprintf("bad field, expected %v, found %v", field, typ.Fields[index].Name))
	}
	a.Inner[index].(*prog.ConstArg).Val = value
}