blob: a7a5530e328a037668b09c71ea21e3043a7fe4d4 [file] [log] [blame]
// 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.
// This file is shared between executor and csource package.
// Implementation of syz_usb_* pseudo-syscalls.
#define USB_DEBUG 0
#define USB_MAX_IFACE_NUM 4
#define USB_MAX_EP_NUM 32
struct usb_iface_index {
struct usb_interface_descriptor* iface;
struct usb_endpoint_descriptor* eps[USB_MAX_EP_NUM];
unsigned eps_num;
};
struct usb_device_index {
struct usb_device_descriptor* dev;
struct usb_config_descriptor* config;
unsigned config_length;
struct usb_iface_index ifaces[USB_MAX_IFACE_NUM];
unsigned ifaces_num;
};
static bool parse_usb_descriptor(char* buffer, size_t length, struct usb_device_index* index)
{
if (length < sizeof(*index->dev) + sizeof(*index->config))
return false;
memset(index, 0, sizeof(*index));
index->dev = (struct usb_device_descriptor*)buffer;
index->config = (struct usb_config_descriptor*)(buffer + sizeof(*index->dev));
index->config_length = length - sizeof(*index->dev);
size_t offset = 0;
while (true) {
if (offset + 1 >= length)
break;
uint8 desc_length = buffer[offset];
uint8 desc_type = buffer[offset + 1];
if (desc_length <= 2)
break;
if (offset + desc_length > length)
break;
if (desc_type == USB_DT_INTERFACE && index->ifaces_num < USB_MAX_IFACE_NUM) {
struct usb_interface_descriptor* iface = (struct usb_interface_descriptor*)(buffer + offset);
debug("parse_usb_descriptor: found interface #%u (%d, %d) at %p\n",
index->ifaces_num, iface->bInterfaceNumber, iface->bAlternateSetting, iface);
index->ifaces[index->ifaces_num++].iface = iface;
}
if (desc_type == USB_DT_ENDPOINT && index->ifaces_num > 0) {
struct usb_iface_index* iface = &index->ifaces[index->ifaces_num - 1];
debug("parse_usb_descriptor: found endpoint #%u at %p\n", iface->eps_num, buffer + offset);
if (iface->eps_num < USB_MAX_EP_NUM)
iface->eps[iface->eps_num++] = (struct usb_endpoint_descriptor*)(buffer + offset);
}
offset += desc_length;
}
return true;
}
enum usb_fuzzer_event_type {
USB_FUZZER_EVENT_INVALID,
USB_FUZZER_EVENT_CONNECT,
USB_FUZZER_EVENT_DISCONNECT,
USB_FUZZER_EVENT_SUSPEND,
USB_FUZZER_EVENT_RESUME,
USB_FUZZER_EVENT_CONTROL,
};
struct usb_fuzzer_event {
uint32 type;
uint32 length;
char data[0];
};
struct usb_fuzzer_init {
uint64 speed;
const char* driver_name;
const char* device_name;
};
struct usb_fuzzer_ep_io {
uint16 ep;
uint16 flags;
uint32 length;
char data[0];
};
#define USB_FUZZER_IOCTL_INIT _IOW('U', 0, struct usb_fuzzer_init)
#define USB_FUZZER_IOCTL_RUN _IO('U', 1)
#define USB_FUZZER_IOCTL_EVENT_FETCH _IOR('U', 2, struct usb_fuzzer_event)
#define USB_FUZZER_IOCTL_EP0_WRITE _IOW('U', 3, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_EP0_READ _IOWR('U', 4, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_EP_ENABLE _IOW('U', 5, struct usb_endpoint_descriptor)
#define USB_FUZZER_IOCTL_EP_WRITE _IOW('U', 7, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_EP_READ _IOWR('U', 8, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_CONFIGURE _IO('U', 9)
#define USB_FUZZER_IOCTL_VBUS_DRAW _IOW('U', 10, uint32)
int usb_fuzzer_open()
{
return open("/sys/kernel/debug/usb-fuzzer", O_RDWR);
}
int usb_fuzzer_init(int fd, uint32 speed, const char* driver, const char* device)
{
struct usb_fuzzer_init arg;
arg.speed = speed;
arg.driver_name = driver;
arg.device_name = device;
return ioctl(fd, USB_FUZZER_IOCTL_INIT, &arg);
}
int usb_fuzzer_run(int fd)
{
return ioctl(fd, USB_FUZZER_IOCTL_RUN, 0);
}
int usb_fuzzer_event_fetch(int fd, struct usb_fuzzer_event* event)
{
return ioctl(fd, USB_FUZZER_IOCTL_EVENT_FETCH, event);
}
int usb_fuzzer_ep0_write(int fd, struct usb_fuzzer_ep_io* io)
{
return ioctl(fd, USB_FUZZER_IOCTL_EP0_WRITE, io);
}
int usb_fuzzer_ep0_read(int fd, struct usb_fuzzer_ep_io* io)
{
return ioctl(fd, USB_FUZZER_IOCTL_EP0_READ, io);
}
int usb_fuzzer_ep_write(int fd, struct usb_fuzzer_ep_io* io)
{
return ioctl(fd, USB_FUZZER_IOCTL_EP_WRITE, io);
}
int usb_fuzzer_ep_read(int fd, struct usb_fuzzer_ep_io* io)
{
return ioctl(fd, USB_FUZZER_IOCTL_EP_READ, io);
}
int usb_fuzzer_ep_enable(int fd, struct usb_endpoint_descriptor* desc)
{
return ioctl(fd, USB_FUZZER_IOCTL_EP_ENABLE, desc);
}
int usb_fuzzer_configure(int fd)
{
return ioctl(fd, USB_FUZZER_IOCTL_CONFIGURE, 0);
}
int usb_fuzzer_vbus_draw(int fd, uint32 power)
{
return ioctl(fd, USB_FUZZER_IOCTL_VBUS_DRAW, power);
}
#define USB_MAX_PACKET_SIZE 1024
struct usb_fuzzer_control_event {
struct usb_fuzzer_event inner;
struct usb_ctrlrequest ctrl;
char data[USB_MAX_PACKET_SIZE];
};
struct usb_fuzzer_ep_io_data {
struct usb_fuzzer_ep_io inner;
char data[USB_MAX_PACKET_SIZE];
};
struct vusb_connect_string_descriptor {
uint32 len;
char* str;
} __attribute__((packed));
struct vusb_connect_descriptors {
uint32 qual_len;
char* qual;
uint32 bos_len;
char* bos;
uint32 strs_len;
struct vusb_connect_string_descriptor strs[0];
} __attribute__((packed));
static const char default_string[] = {
8, USB_DT_STRING,
's', 0, 'y', 0, 'z', 0 // UTF16-encoded "syz"
};
static const char default_lang_id[] = {
4, USB_DT_STRING,
0x09, 0x04 // English (United States)
};
static bool lookup_connect_response(struct vusb_connect_descriptors* descs, struct usb_device_index* index,
struct usb_ctrlrequest* ctrl, char** response_data, uint32* response_length)
{
uint8 str_idx;
switch (ctrl->bRequestType & USB_TYPE_MASK) {
case USB_TYPE_STANDARD:
switch (ctrl->bRequest) {
case USB_REQ_GET_DESCRIPTOR:
switch (ctrl->wValue >> 8) {
case USB_DT_DEVICE:
*response_data = (char*)index->dev;
*response_length = sizeof(*index->dev);
return true;
case USB_DT_CONFIG:
*response_data = (char*)index->config;
*response_length = index->config_length;
return true;
case USB_DT_STRING:
str_idx = (uint8)ctrl->wValue;
if (descs && str_idx < descs->strs_len) {
*response_data = descs->strs[str_idx].str;
*response_length = descs->strs[str_idx].len;
return true;
}
if (str_idx == 0) {
*response_data = (char*)&default_lang_id[0];
*response_length = default_lang_id[0];
return true;
}
*response_data = (char*)&default_string[0];
*response_length = default_string[0];
return true;
case USB_DT_BOS:
*response_data = descs->bos;
*response_length = descs->bos_len;
return true;
case USB_DT_DEVICE_QUALIFIER:
if (!descs->qual) {
// Fill in DEVICE_QUALIFIER based on DEVICE if not provided.
struct usb_qualifier_descriptor* qual =
(struct usb_qualifier_descriptor*)response_data;
qual->bLength = sizeof(*qual);
qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
qual->bcdUSB = index->dev->bcdUSB;
qual->bDeviceClass = index->dev->bDeviceClass;
qual->bDeviceSubClass = index->dev->bDeviceSubClass;
qual->bDeviceProtocol = index->dev->bDeviceProtocol;
qual->bMaxPacketSize0 = index->dev->bMaxPacketSize0;
qual->bNumConfigurations = index->dev->bNumConfigurations;
qual->bRESERVED = 0;
*response_length = sizeof(*qual);
return true;
}
*response_data = descs->qual;
*response_length = descs->qual_len;
return true;
default:
fail("lookup_connect_response: no response");
return false;
}
break;
default:
fail("lookup_connect_response: no response");
return false;
}
break;
default:
fail("lookup_connect_response: no response");
return false;
}
return false;
}
static volatile long syz_usb_connect(volatile long a0, volatile long a1, volatile long a2, volatile long a3)
{
uint64 speed = a0;
uint64 dev_len = a1;
char* dev = (char*)a2;
struct vusb_connect_descriptors* descs = (struct vusb_connect_descriptors*)a3;
debug("syz_usb_connect: dev: %p\n", dev);
if (!dev) {
debug("syz_usb_connect: dev is null\n");
return -1;
}
debug("syz_usb_connect: device data:\n");
debug_dump_data(dev, dev_len);
struct usb_device_index index;
memset(&index, 0, sizeof(index));
int rv = 0;
NONFAILING(rv = parse_usb_descriptor(dev, dev_len, &index));
if (!rv) {
debug("syz_usb_connect: parse_usb_descriptor failed with %d\n", rv);
return rv;
}
debug("syz_usb_connect: parsed usb descriptor\n");
int fd = usb_fuzzer_open();
if (fd < 0) {
debug("syz_usb_connect: usb_fuzzer_open failed with %d\n", rv);
return fd;
}
debug("syz_usb_connect: usb_fuzzer_open success\n");
// TODO: consider creating two dummy_udc's per proc to increace the chance of
// triggering interaction between multiple USB devices within the same program.
char device[32];
sprintf(&device[0], "dummy_udc.%llu", procid);
rv = usb_fuzzer_init(fd, speed, "dummy_udc", &device[0]);
if (rv < 0) {
debug("syz_usb_connect: usb_fuzzer_init failed with %d\n", rv);
return rv;
}
debug("syz_usb_connect: usb_fuzzer_init success\n");
rv = usb_fuzzer_run(fd);
if (rv < 0) {
debug("syz_usb_connect: usb_fuzzer_run failed with %d\n", rv);
return rv;
}
debug("syz_usb_connect: usb_fuzzer_run success\n");
bool done = false;
while (!done) {
struct usb_fuzzer_control_event event;
event.inner.type = 0;
event.inner.length = sizeof(event.ctrl);
rv = usb_fuzzer_event_fetch(fd, (struct usb_fuzzer_event*)&event);
if (rv < 0) {
debug("syz_usb_connect: usb_fuzzer_event_fetch failed with %d\n", rv);
return rv;
}
if (event.inner.type != USB_FUZZER_EVENT_CONTROL)
continue;
debug("syz_usb_connect: bReqType: 0x%x (%s), bReq: 0x%x, wVal: 0x%x, wIdx: 0x%x, wLen: %d\n",
event.ctrl.bRequestType, (event.ctrl.bRequestType & USB_DIR_IN) ? "IN" : "OUT",
event.ctrl.bRequest, event.ctrl.wValue, event.ctrl.wIndex, event.ctrl.wLength);
bool response_found = false;
char* response_data = NULL;
uint32 response_length = 0;
if (event.ctrl.bRequestType & USB_DIR_IN) {
NONFAILING(response_found = lookup_connect_response(descs, &index, &event.ctrl, &response_data, &response_length));
if (!response_found) {
debug("syz_usb_connect: unknown control IN request\n");
return -1;
}
} else {
if ((event.ctrl.bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD ||
event.ctrl.bRequest != USB_REQ_SET_CONFIGURATION) {
fail("syz_usb_connect: unknown control OUT request");
return -1;
}
done = true;
}
if (done) {
rv = usb_fuzzer_vbus_draw(fd, index.config->bMaxPower);
if (rv < 0) {
debug("syz_usb_connect: usb_fuzzer_vbus_draw failed with %d\n", rv);
return rv;
}
rv = usb_fuzzer_configure(fd);
if (rv < 0) {
debug("syz_usb_connect: usb_fuzzer_configure failed with %d\n", rv);
return rv;
}
unsigned ep;
for (ep = 0; ep < index.ifaces[0].eps_num; ep++) {
rv = usb_fuzzer_ep_enable(fd, index.ifaces[0].eps[ep]);
if (rv < 0) {
debug("syz_usb_connect: usb_fuzzer_ep_enable(%d) failed with %d\n", ep, rv);
} else {
debug("syz_usb_connect: endpoint %d enabled\n", ep);
}
}
}
struct usb_fuzzer_ep_io_data response;
response.inner.ep = 0;
response.inner.flags = 0;
if (response_length > sizeof(response.data))
response_length = 0;
if (event.ctrl.wLength < response_length)
response_length = event.ctrl.wLength;
response.inner.length = response_length;
if (response_data)
memcpy(&response.data[0], response_data, response_length);
else
memset(&response.data[0], 0, response_length);
if (event.ctrl.bRequestType & USB_DIR_IN) {
debug("syz_usb_connect: writing %d bytes\n", response.inner.length);
rv = usb_fuzzer_ep0_write(fd, (struct usb_fuzzer_ep_io*)&response);
} else {
rv = usb_fuzzer_ep0_read(fd, (struct usb_fuzzer_ep_io*)&response);
debug("syz_usb_connect: read %d bytes\n", response.inner.length);
debug_dump_data(&event.data[0], response.inner.length);
}
if (rv < 0) {
debug("syz_usb_connect: usb_fuzzer_ep0_read/write failed with %d\n", rv);
return rv;
}
}
sleep_ms(200);
debug("syz_usb_connect: configured\n");
return fd;
}
#if SYZ_EXECUTOR || __NR_syz_usb_control_io
struct vusb_descriptor {
uint8 req_type;
uint8 desc_type;
uint32 len;
char data[0];
} __attribute__((packed));
struct vusb_descriptors {
uint32 len;
struct vusb_descriptor* generic;
struct vusb_descriptor* descs[0];
} __attribute__((packed));
struct vusb_response {
uint8 type;
uint8 req;
uint32 len;
char data[0];
} __attribute__((packed));
struct vusb_responses {
uint32 len;
struct vusb_response* generic;
struct vusb_response* resps[0];
} __attribute__((packed));
static bool lookup_control_response(struct vusb_descriptors* descs, struct vusb_responses* resps,
struct usb_ctrlrequest* ctrl, char** response_data, uint32* response_length)
{
int descs_num = 0;
int resps_num = 0;
if (descs)
descs_num = (descs->len - offsetof(struct vusb_descriptors, descs)) / sizeof(descs->descs[0]);
if (resps)
resps_num = (resps->len - offsetof(struct vusb_responses, resps)) / sizeof(resps->resps[0]);
uint8 req = ctrl->bRequest;
uint8 req_type = ctrl->bRequestType & USB_TYPE_MASK;
uint8 desc_type = ctrl->wValue >> 8;
if (req == USB_REQ_GET_DESCRIPTOR) {
int i;
for (i = 0; i < descs_num; i++) {
struct vusb_descriptor* desc = descs->descs[i];
if (!desc)
continue;
if (desc->req_type == req_type && desc->desc_type == desc_type) {
*response_length = desc->len;
if (*response_length != 0)
*response_data = &desc->data[0];
else
*response_data = NULL;
return true;
}
}
if (descs && descs->generic) {
*response_data = &descs->generic->data[0];
*response_length = descs->generic->len;
return true;
}
} else {
int i;
for (i = 0; i < resps_num; i++) {
struct vusb_response* resp = resps->resps[i];
if (!resp)
continue;
if (resp->type == req_type && resp->req == req) {
*response_length = resp->len;
if (*response_length != 0)
*response_data = &resp->data[0];
else
*response_data = NULL;
return true;
}
}
if (resps && resps->generic) {
*response_data = &resps->generic->data[0];
*response_length = resps->generic->len;
return true;
}
}
return false;
}
#if USB_DEBUG
#include <linux/hid.h>
#include <linux/usb/cdc.h>
#include <linux/usb/ch11.h>
#include <linux/usb/ch9.h>
static void analyze_control_request(struct usb_ctrlrequest* ctrl)
{
switch (ctrl->bRequestType & USB_TYPE_MASK) {
case USB_TYPE_STANDARD:
switch (ctrl->bRequest) {
case USB_REQ_GET_DESCRIPTOR:
switch (ctrl->wValue >> 8) {
case USB_DT_DEVICE:
case USB_DT_CONFIG:
case USB_DT_STRING:
case HID_DT_REPORT:
case USB_DT_BOS:
case USB_DT_HUB:
case USB_DT_SS_HUB:
return;
}
}
break;
case USB_TYPE_CLASS:
switch (ctrl->bRequest) {
case USB_REQ_GET_INTERFACE:
case USB_REQ_GET_CONFIGURATION:
case USB_REQ_GET_STATUS:
case USB_CDC_GET_NTB_PARAMETERS:
return;
}
}
fail("analyze_control_request: unknown control request (0x%x, 0x%x, 0x%x)",
ctrl->bRequestType, ctrl->bRequest, ctrl->wValue);
}
#endif
static volatile long syz_usb_control_io(volatile long a0, volatile long a1, volatile long a2)
{
int fd = a0;
struct vusb_descriptors* descs = (struct vusb_descriptors*)a1;
struct vusb_responses* resps = (struct vusb_responses*)a2;
struct usb_fuzzer_control_event event;
event.inner.type = 0;
event.inner.length = USB_MAX_PACKET_SIZE;
int rv = usb_fuzzer_event_fetch(fd, (struct usb_fuzzer_event*)&event);
if (rv < 0) {
debug("syz_usb_control_io: usb_fuzzer_ep0_read failed with %d\n", rv);
return rv;
}
if (event.inner.type != USB_FUZZER_EVENT_CONTROL) {
debug("syz_usb_control_io: wrong event type: %d\n", (int)event.inner.type);
return -1;
}
debug("syz_usb_control_io: bReqType: 0x%x (%s), bReq: 0x%x, wVal: 0x%x, wIdx: 0x%x, wLen: %d\n",
event.ctrl.bRequestType, (event.ctrl.bRequestType & USB_DIR_IN) ? "IN" : "OUT",
event.ctrl.bRequest, event.ctrl.wValue, event.ctrl.wIndex, event.ctrl.wLength);
bool response_found = false;
char* response_data = NULL;
uint32 response_length = 0;
if ((event.ctrl.bRequestType & USB_DIR_IN) && event.ctrl.wLength) {
NONFAILING(response_found = lookup_control_response(descs, resps, &event.ctrl, &response_data, &response_length));
if (!response_found) {
#if USB_DEBUG
analyze_control_request(&event.ctrl);
#endif
debug("syz_usb_control_io: unknown control IN request\n");
return -1;
}
} else {
response_length = event.ctrl.wLength;
}
struct usb_fuzzer_ep_io_data response;
response.inner.ep = 0;
response.inner.flags = 0;
if (response_length > sizeof(response.data))
response_length = 0;
if (event.ctrl.wLength < response_length)
response_length = event.ctrl.wLength;
if ((event.ctrl.bRequestType & USB_DIR_IN) && !event.ctrl.wLength) {
// Something fishy is going on, try to read more data.
response_length = USB_MAX_PACKET_SIZE;
}
response.inner.length = response_length;
if (response_data)
memcpy(&response.data[0], response_data, response_length);
else
memset(&response.data[0], 0, response_length);
if ((event.ctrl.bRequestType & USB_DIR_IN) && event.ctrl.wLength) {
debug("syz_usb_control_io: writing %d bytes\n", response.inner.length);
debug_dump_data(&response.data[0], response.inner.length);
rv = usb_fuzzer_ep0_write(fd, (struct usb_fuzzer_ep_io*)&response);
} else {
rv = usb_fuzzer_ep0_read(fd, (struct usb_fuzzer_ep_io*)&response);
debug("syz_usb_control_io: read %d bytes\n", response.inner.length);
debug_dump_data(&response.data[0], response.inner.length);
}
if (rv < 0) {
debug("syz_usb_control_io: usb_fuzzer_ep0_read/write failed with %d\n", rv);
return rv;
}
sleep_ms(200);
return 0;
}
#endif
#if SYZ_EXECUTOR || __NR_syz_usb_ep_write
static volatile long syz_usb_ep_write(volatile long a0, volatile long a1, volatile long a2, volatile long a3)
{
int fd = a0;
uint16 ep = a1;
uint32 len = a2;
char* data = (char*)a3;
struct usb_fuzzer_ep_io_data io_data;
io_data.inner.ep = ep;
io_data.inner.flags = 0;
if (len > sizeof(io_data.data))
len = sizeof(io_data.data);
io_data.inner.length = len;
NONFAILING(memcpy(&io_data.data[0], data, len));
int rv = usb_fuzzer_ep_write(fd, (struct usb_fuzzer_ep_io*)&io_data);
if (rv < 0) {
debug("syz_usb_ep_write: usb_fuzzer_ep_write failed with %d\n", rv);
return rv;
}
sleep_ms(200);
return 0;
}
#endif
#if SYZ_EXECUTOR || __NR_syz_usb_ep_read
static volatile long syz_usb_ep_read(volatile long a0, volatile long a1, volatile long a2, volatile long a3)
{
int fd = a0;
uint16 ep = a1;
uint32 len = a2;
char* data = (char*)a3;
struct usb_fuzzer_ep_io_data io_data;
io_data.inner.ep = ep;
io_data.inner.flags = 0;
if (len > sizeof(io_data.data))
len = sizeof(io_data.data);
io_data.inner.length = len;
int rv = usb_fuzzer_ep_read(fd, (struct usb_fuzzer_ep_io*)&io_data);
if (rv < 0) {
debug("syz_usb_ep_read: usb_fuzzer_ep_read failed with %d\n", rv);
return rv;
}
NONFAILING(memcpy(&data[0], &io_data.data[0], io_data.inner.length));
debug("syz_usb_ep_read: received data:\n");
debug_dump_data(&io_data.data[0], io_data.inner.length);
sleep_ms(200);
return 0;
}
#endif
#if SYZ_EXECUTOR || __NR_syz_usb_disconnect
static volatile long syz_usb_disconnect(volatile long a0)
{
int fd = a0;
int rv = close(fd);
sleep_ms(200);
return rv;
}
#endif