// https://syzkaller.appspot.com/bug?id=d44fa8c0e98bf067adc81dad14e4ac020aac7de5 // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef __NR_mmap #define __NR_mmap 222 #endif static unsigned long long procid; static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } #define MAX_FDS 30 #define USB_MAX_IFACE_NUM 4 #define USB_MAX_EP_NUM 32 #define USB_MAX_FDS 6 struct usb_endpoint_index { struct usb_endpoint_descriptor desc; int handle; }; struct usb_iface_index { struct usb_interface_descriptor* iface; uint8_t bInterfaceNumber; uint8_t bAlternateSetting; uint8_t bInterfaceClass; struct usb_endpoint_index eps[USB_MAX_EP_NUM]; int eps_num; }; struct usb_device_index { struct usb_device_descriptor* dev; struct usb_config_descriptor* config; uint8_t bDeviceClass; uint8_t bMaxPower; int config_length; struct usb_iface_index ifaces[USB_MAX_IFACE_NUM]; int ifaces_num; int iface_cur; }; struct usb_info { int fd; struct usb_device_index index; }; static struct usb_info usb_devices[USB_MAX_FDS]; static struct usb_device_index* lookup_usb_index(int fd) { for (int i = 0; i < USB_MAX_FDS; i++) { if (__atomic_load_n(&usb_devices[i].fd, __ATOMIC_ACQUIRE) == fd) return &usb_devices[i].index; } return NULL; } static int usb_devices_num; static bool parse_usb_descriptor(const 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->bDeviceClass = index->dev->bDeviceClass; index->bMaxPower = index->config->bMaxPower; index->config_length = length - sizeof(*index->dev); index->iface_cur = -1; size_t offset = 0; while (true) { if (offset + 1 >= length) break; uint8_t desc_length = buffer[offset]; uint8_t 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); index->ifaces[index->ifaces_num].iface = iface; index->ifaces[index->ifaces_num].bInterfaceNumber = iface->bInterfaceNumber; index->ifaces[index->ifaces_num].bAlternateSetting = iface->bAlternateSetting; index->ifaces[index->ifaces_num].bInterfaceClass = iface->bInterfaceClass; index->ifaces_num++; } if (desc_type == USB_DT_ENDPOINT && index->ifaces_num > 0) { struct usb_iface_index* iface = &index->ifaces[index->ifaces_num - 1]; if (iface->eps_num < USB_MAX_EP_NUM) { memcpy(&iface->eps[iface->eps_num].desc, buffer + offset, sizeof(iface->eps[iface->eps_num].desc)); iface->eps_num++; } } offset += desc_length; } return true; } static struct usb_device_index* add_usb_index(int fd, const char* dev, size_t dev_len) { int i = __atomic_fetch_add(&usb_devices_num, 1, __ATOMIC_RELAXED); if (i >= USB_MAX_FDS) return NULL; if (!parse_usb_descriptor(dev, dev_len, &usb_devices[i].index)) return NULL; __atomic_store_n(&usb_devices[i].fd, fd, __ATOMIC_RELEASE); return &usb_devices[i].index; } struct vusb_connect_string_descriptor { uint32_t len; char* str; } __attribute__((packed)); struct vusb_connect_descriptors { uint32_t qual_len; char* qual; uint32_t bos_len; char* bos; uint32_t 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}; static const char default_lang_id[] = {4, USB_DT_STRING, 0x09, 0x04}; static bool lookup_connect_response_in(int fd, const struct vusb_connect_descriptors* descs, const struct usb_ctrlrequest* ctrl, struct usb_qualifier_descriptor* qual, char** response_data, uint32_t* response_length) { struct usb_device_index* index = lookup_usb_index(fd); uint8_t str_idx; if (!index) return false; 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_t)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) { 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_data = (char*)qual; *response_length = sizeof(*qual); return true; } *response_data = descs->qual; *response_length = descs->qual_len; return true; default: break; } break; default: break; } break; default: break; } return false; } typedef bool (*lookup_connect_out_response_t)( int fd, const struct vusb_connect_descriptors* descs, const struct usb_ctrlrequest* ctrl, bool* done); static bool lookup_connect_response_out_generic( int fd, const struct vusb_connect_descriptors* descs, const struct usb_ctrlrequest* ctrl, bool* done) { switch (ctrl->bRequestType & USB_TYPE_MASK) { case USB_TYPE_STANDARD: switch (ctrl->bRequest) { case USB_REQ_SET_CONFIGURATION: *done = true; return true; default: break; } break; } return false; } #define UDC_NAME_LENGTH_MAX 128 struct usb_raw_init { __u8 driver_name[UDC_NAME_LENGTH_MAX]; __u8 device_name[UDC_NAME_LENGTH_MAX]; __u8 speed; }; enum usb_raw_event_type { USB_RAW_EVENT_INVALID = 0, USB_RAW_EVENT_CONNECT = 1, USB_RAW_EVENT_CONTROL = 2, }; struct usb_raw_event { __u32 type; __u32 length; __u8 data[0]; }; struct usb_raw_ep_io { __u16 ep; __u16 flags; __u32 length; __u8 data[0]; }; #define USB_RAW_EPS_NUM_MAX 30 #define USB_RAW_EP_NAME_MAX 16 #define USB_RAW_EP_ADDR_ANY 0xff struct usb_raw_ep_caps { __u32 type_control : 1; __u32 type_iso : 1; __u32 type_bulk : 1; __u32 type_int : 1; __u32 dir_in : 1; __u32 dir_out : 1; }; struct usb_raw_ep_limits { __u16 maxpacket_limit; __u16 max_streams; __u32 reserved; }; struct usb_raw_ep_info { __u8 name[USB_RAW_EP_NAME_MAX]; __u32 addr; struct usb_raw_ep_caps caps; struct usb_raw_ep_limits limits; }; struct usb_raw_eps_info { struct usb_raw_ep_info eps[USB_RAW_EPS_NUM_MAX]; }; #define USB_RAW_IOCTL_INIT _IOW('U', 0, struct usb_raw_init) #define USB_RAW_IOCTL_RUN _IO('U', 1) #define USB_RAW_IOCTL_EVENT_FETCH _IOR('U', 2, struct usb_raw_event) #define USB_RAW_IOCTL_EP0_WRITE _IOW('U', 3, struct usb_raw_ep_io) #define USB_RAW_IOCTL_EP0_READ _IOWR('U', 4, struct usb_raw_ep_io) #define USB_RAW_IOCTL_EP_ENABLE _IOW('U', 5, struct usb_endpoint_descriptor) #define USB_RAW_IOCTL_EP_DISABLE _IOW('U', 6, __u32) #define USB_RAW_IOCTL_EP_WRITE _IOW('U', 7, struct usb_raw_ep_io) #define USB_RAW_IOCTL_EP_READ _IOWR('U', 8, struct usb_raw_ep_io) #define USB_RAW_IOCTL_CONFIGURE _IO('U', 9) #define USB_RAW_IOCTL_VBUS_DRAW _IOW('U', 10, __u32) #define USB_RAW_IOCTL_EPS_INFO _IOR('U', 11, struct usb_raw_eps_info) #define USB_RAW_IOCTL_EP0_STALL _IO('U', 12) #define USB_RAW_IOCTL_EP_SET_HALT _IOW('U', 13, __u32) #define USB_RAW_IOCTL_EP_CLEAR_HALT _IOW('U', 14, __u32) #define USB_RAW_IOCTL_EP_SET_WEDGE _IOW('U', 15, __u32) static int usb_raw_open() { return open("/dev/raw-gadget", O_RDWR); } static int usb_raw_init(int fd, uint32_t speed, const char* driver, const char* device) { struct usb_raw_init arg; strncpy((char*)&arg.driver_name[0], driver, sizeof(arg.driver_name)); strncpy((char*)&arg.device_name[0], device, sizeof(arg.device_name)); arg.speed = speed; return ioctl(fd, USB_RAW_IOCTL_INIT, &arg); } static int usb_raw_run(int fd) { return ioctl(fd, USB_RAW_IOCTL_RUN, 0); } static int usb_raw_configure(int fd) { return ioctl(fd, USB_RAW_IOCTL_CONFIGURE, 0); } static int usb_raw_vbus_draw(int fd, uint32_t power) { return ioctl(fd, USB_RAW_IOCTL_VBUS_DRAW, power); } static int usb_raw_ep0_write(int fd, struct usb_raw_ep_io* io) { return ioctl(fd, USB_RAW_IOCTL_EP0_WRITE, io); } static int usb_raw_ep0_read(int fd, struct usb_raw_ep_io* io) { return ioctl(fd, USB_RAW_IOCTL_EP0_READ, io); } static int usb_raw_event_fetch(int fd, struct usb_raw_event* event) { return ioctl(fd, USB_RAW_IOCTL_EVENT_FETCH, event); } static int usb_raw_ep_enable(int fd, struct usb_endpoint_descriptor* desc) { return ioctl(fd, USB_RAW_IOCTL_EP_ENABLE, desc); } static int usb_raw_ep_disable(int fd, int ep) { return ioctl(fd, USB_RAW_IOCTL_EP_DISABLE, ep); } static int usb_raw_ep0_stall(int fd) { return ioctl(fd, USB_RAW_IOCTL_EP0_STALL, 0); } #define USB_MAX_PACKET_SIZE 4096 struct usb_raw_control_event { struct usb_raw_event inner; struct usb_ctrlrequest ctrl; char data[USB_MAX_PACKET_SIZE]; }; struct usb_raw_ep_io_data { struct usb_raw_ep_io inner; char data[USB_MAX_PACKET_SIZE]; }; static void set_interface(int fd, int n) { struct usb_device_index* index = lookup_usb_index(fd); if (!index) return; if (index->iface_cur >= 0 && index->iface_cur < index->ifaces_num) { for (int ep = 0; ep < index->ifaces[index->iface_cur].eps_num; ep++) { int rv = usb_raw_ep_disable( fd, index->ifaces[index->iface_cur].eps[ep].handle); if (rv < 0) { } else { } } } if (n >= 0 && n < index->ifaces_num) { for (int ep = 0; ep < index->ifaces[n].eps_num; ep++) { int rv = usb_raw_ep_enable(fd, &index->ifaces[n].eps[ep].desc); if (rv < 0) { } else { index->ifaces[n].eps[ep].handle = rv; } } index->iface_cur = n; } } static int configure_device(int fd) { struct usb_device_index* index = lookup_usb_index(fd); if (!index) return -1; int rv = usb_raw_vbus_draw(fd, index->bMaxPower); if (rv < 0) { return rv; } rv = usb_raw_configure(fd); if (rv < 0) { return rv; } set_interface(fd, 0); return 0; } static volatile long syz_usb_connect_impl(uint64_t speed, uint64_t dev_len, const char* dev, const struct vusb_connect_descriptors* descs, lookup_connect_out_response_t lookup_connect_response_out) { if (!dev) { return -1; } int fd = usb_raw_open(); if (fd < 0) { return fd; } if (fd >= MAX_FDS) { close(fd); return -1; } struct usb_device_index* index = add_usb_index(fd, dev, dev_len); if (!index) { return -1; } char device[32]; sprintf(&device[0], "dummy_udc.%llu", procid); int rv = usb_raw_init(fd, speed, "dummy_udc", &device[0]); if (rv < 0) { return rv; } rv = usb_raw_run(fd); if (rv < 0) { return rv; } bool done = false; while (!done) { struct usb_raw_control_event event; event.inner.type = 0; event.inner.length = sizeof(event.ctrl); rv = usb_raw_event_fetch(fd, (struct usb_raw_event*)&event); if (rv < 0) { return rv; } if (event.inner.type != USB_RAW_EVENT_CONTROL) continue; char* response_data = NULL; uint32_t response_length = 0; struct usb_qualifier_descriptor qual; if (event.ctrl.bRequestType & USB_DIR_IN) { if (!lookup_connect_response_in(fd, descs, &event.ctrl, &qual, &response_data, &response_length)) { usb_raw_ep0_stall(fd); continue; } } else { if (!lookup_connect_response_out(fd, descs, &event.ctrl, &done)) { usb_raw_ep0_stall(fd); continue; } response_data = NULL; response_length = event.ctrl.wLength; } if ((event.ctrl.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD && event.ctrl.bRequest == USB_REQ_SET_CONFIGURATION) { rv = configure_device(fd); if (rv < 0) { return rv; } } struct usb_raw_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) { rv = usb_raw_ep0_write(fd, (struct usb_raw_ep_io*)&response); } else { rv = usb_raw_ep0_read(fd, (struct usb_raw_ep_io*)&response); } if (rv < 0) { return rv; } } sleep_ms(200); return fd; } static volatile long syz_usb_connect(volatile long a0, volatile long a1, volatile long a2, volatile long a3) { uint64_t speed = a0; uint64_t dev_len = a1; const char* dev = (const char*)a2; const struct vusb_connect_descriptors* descs = (const struct vusb_connect_descriptors*)a3; return syz_usb_connect_impl(speed, dev_len, dev, descs, &lookup_connect_response_out_generic); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); memcpy((void*)0x20000300, "\x12\x01\x00\x00\x76\x58\x2a\x40\xde\x0c\x12\x00\xd6\x1e\x01\x02\x03" "\x01\x09\x02\x22\x00\x01\x00\x00\x00\x00\x09\x04\x00\x00\x01\x03\x9c" "\x79\x00\x09\x05\x00\x00\x00\x02\x00\x00\x00\x07\x05\x81\x37\xa5", 50); syz_usb_connect(/*speed=*/0, /*dev_len=*/0x34, /*dev=*/0x20000300, /*conn_descs=*/0); return 0; }