// https://syzkaller.appspot.com/bug?id=3ec1dad62657fef22282536d7532dbb65eee778a // 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 unsigned long long procid; static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } #define USB_DEBUG 0 #define USB_MAX_EP_NUM 32 struct usb_device_index { struct usb_device_descriptor* dev; struct usb_config_descriptor* config; unsigned config_length; struct usb_interface_descriptor* iface; struct usb_endpoint_descriptor* eps[USB_MAX_EP_NUM]; unsigned eps_num; }; static bool parse_usb_descriptor(char* buffer, size_t length, struct usb_device_index* index) { if (length < sizeof(*index->dev) + sizeof(*index->config) + sizeof(*index->iface)) return false; index->dev = (struct usb_device_descriptor*)buffer; index->config = (struct usb_config_descriptor*)(buffer + sizeof(*index->dev)); index->config_length = length - sizeof(*index->dev); index->iface = (struct usb_interface_descriptor*)(buffer + sizeof(*index->dev) + sizeof(*index->config)); index->eps_num = 0; 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_ENDPOINT) { index->eps[index->eps_num] = (struct usb_endpoint_descriptor*)(buffer + offset); index->eps_num++; } if (index->eps_num == USB_MAX_EP_NUM) break; 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_t type; uint32_t length; char data[0]; }; struct usb_fuzzer_init { uint64_t speed; const char* driver_name; const char* device_name; }; struct usb_fuzzer_ep_io { uint16_t ep; uint16_t flags; uint32_t 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_t) int usb_fuzzer_open() { return open("/sys/kernel/debug/usb-fuzzer", O_RDWR); } int usb_fuzzer_init(int fd, uint32_t 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_t 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_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 = "syzkaller"; static bool lookup_connect_response(struct vusb_connect_descriptors* descs, struct usb_device_index* index, struct usb_ctrlrequest* ctrl, char** response_data, uint32_t* response_length) { uint8_t 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_t)ctrl->wValue; if (str_idx >= descs->strs_len) { *response_data = (char*)default_string; *response_length = strlen(default_string); } else { *response_data = descs->strs[str_idx].str; *response_length = descs->strs[str_idx].len; } return true; case USB_DT_BOS: *response_data = descs->bos; *response_length = descs->bos_len; return true; case USB_DT_DEVICE_QUALIFIER: *response_data = descs->qual; *response_length = descs->qual_len; return true; default: exit(1); return false; } break; default: exit(1); return false; } break; default: exit(1); return false; } return false; } 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; char* dev = (char*)a2; struct vusb_connect_descriptors* descs = (struct vusb_connect_descriptors*)a3; if (!dev) { return -1; } struct usb_device_index index; memset(&index, 0, sizeof(index)); int rv = 0; rv = parse_usb_descriptor(dev, dev_len, &index); if (!rv) { return rv; } int fd = usb_fuzzer_open(); if (fd < 0) { return fd; } char device[32]; sprintf(&device[0], "dummy_udc.%llu", procid); rv = usb_fuzzer_init(fd, speed, "dummy_udc", &device[0]); if (rv < 0) { return rv; } rv = usb_fuzzer_run(fd); if (rv < 0) { return rv; } 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) { return rv; } if (event.inner.type != USB_FUZZER_EVENT_CONTROL) continue; bool response_found = false; char* response_data = NULL; uint32_t response_length = 0; if (event.ctrl.bRequestType & USB_DIR_IN) { response_found = lookup_connect_response( descs, &index, &event.ctrl, &response_data, &response_length); if (!response_found) { return -1; } } else { if ((event.ctrl.bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD || event.ctrl.bRequest != USB_REQ_SET_CONFIGURATION) { exit(1); return -1; } done = true; } if (done) { rv = usb_fuzzer_vbus_draw(fd, index.config->bMaxPower); if (rv < 0) { return rv; } rv = usb_fuzzer_configure(fd); if (rv < 0) { return rv; } unsigned ep; for (ep = 0; ep < index.eps_num; ep++) { rv = usb_fuzzer_ep_enable(fd, index.eps[ep]); if (rv < 0) { } else { } } } 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) 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); if (rv < 0) { return rv; } } sleep_ms(200); return fd; } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); memcpy((void*)0x20000000, "\x12\x01\x00\x00\x9e\xf9\xce\x40\xfd\x07\x04\x00" "\x94\xdc\x00\x00\x00\x01\x09\x02\x1b\x00\x01\x00" "\x00\x00\x00\x09\x04\x59\x00\x01\xce\x76\xfa\x00" "\xf3\xf5\x30\xd0\x09\x05\x01\x1b\x00", 45); syz_usb_connect(0, 0x2d, 0x20000000, 0); return 0; }