// https://syzkaller.appspot.com/bug?id=3cd92b1d85428b128503bfa7a250294c9ae00bd8 // 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 #include #include #include #include #include unsigned long long procid; static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } #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 == length) break; if (offset + 1 < length) break; uint8_t length = buffer[offset]; uint8_t type = buffer[offset + 1]; if (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 += 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_EP0_READ _IOWR('U', 2, struct usb_fuzzer_event) #define USB_FUZZER_IOCTL_EP0_WRITE _IOW('U', 3, struct usb_fuzzer_ep_io) #define USB_FUZZER_IOCTL_EP_ENABLE _IOW('U', 4, struct usb_endpoint_descriptor) #define USB_FUZZER_IOCTL_EP_WRITE _IOW('U', 6, struct usb_fuzzer_ep_io) #define USB_FUZZER_IOCTL_CONFIGURE _IO('U', 8) #define USB_FUZZER_IOCTL_VBUS_DRAW _IOW('U', 9, 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_ep0_read(int fd, struct usb_fuzzer_event* event) { return ioctl(fd, USB_FUZZER_IOCTL_EP0_READ, 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_ep_write(int fd, struct usb_fuzzer_ep_io* io) { return ioctl(fd, USB_FUZZER_IOCTL_EP_WRITE, 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; }; 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 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, bool* done) { 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) return false; *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; case USB_REQ_SET_CONFIGURATION: *response_length = 0; *response_data = NULL; *done = true; return true; 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) { int64_t speed = a0; int64_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 = false; rv = parse_usb_descriptor(dev, dev_len, &index); if (!rv) return -1; int fd = usb_fuzzer_open(); if (fd < 0) return -1; char device[32]; sprintf(&device[0], "dummy_udc.%llu", procid); rv = usb_fuzzer_init(fd, speed, "dummy_udc", &device[0]); if (rv < 0) return -1; rv = usb_fuzzer_run(fd); if (rv < 0) return -1; bool done = false; while (!done) { struct usb_fuzzer_control_event event; event.inner.type = 0; event.inner.length = sizeof(event.ctrl); rv = usb_fuzzer_ep0_read(fd, (struct usb_fuzzer_event*)&event); if (rv < 0) return -1; if (event.inner.type != USB_FUZZER_EVENT_CONTROL) continue; bool response_found = false; char* response_data = NULL; uint32_t response_length = 0; response_found = lookup_connect_response( descs, &index, &event.ctrl, &response_data, &response_length, &done); if (!response_found) return -1; if (done) { int rv = usb_fuzzer_vbus_draw(fd, index.config->bMaxPower); if (rv < 0) return -1; rv = usb_fuzzer_configure(fd); if (rv < 0) return -1; unsigned ep; for (ep = 0; ep < index.eps_num; ep++) { rv = usb_fuzzer_ep_enable(fd, index.eps[ep]); if (rv < 0) exit(1); } } struct usb_fuzzer_ep_io_data response; response.inner.ep = 0; response.inner.flags = 0; if (response_length > sizeof(response.data)) response_length = 0; response.inner.length = response_length; if (response_data) memcpy(&response.data[0], response_data, response_length); if (event.ctrl.wLength < response.inner.length) response.inner.length = event.ctrl.wLength; usb_fuzzer_ep0_write(fd, (struct usb_fuzzer_ep_io*)&response); } sleep_ms(200); return fd; } static void setup_common() { if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) { } } static void loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = (200 << 20); setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 32 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 136 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 0; setrlimit(RLIMIT_CORE, &rlim); rlim.rlim_cur = rlim.rlim_max = 256; setrlimit(RLIMIT_NOFILE, &rlim); if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } typedef struct { const char* name; const char* value; } sysctl_t; static const sysctl_t sysctls[] = { {"/proc/sys/kernel/shmmax", "16777216"}, {"/proc/sys/kernel/shmall", "536870912"}, {"/proc/sys/kernel/shmmni", "1024"}, {"/proc/sys/kernel/msgmax", "8192"}, {"/proc/sys/kernel/msgmni", "1024"}, {"/proc/sys/kernel/msgmnb", "1024"}, {"/proc/sys/kernel/sem", "1024 1048576 500 1024"}, }; unsigned i; for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++) write_file(sysctls[i].name, sysctls[i].value); } int wait_for_loop(int pid) { if (pid < 0) exit(1); int status = 0; while (waitpid(-1, &status, __WALL) != pid) { } return WEXITSTATUS(status); } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid != 0) return wait_for_loop(pid); setup_common(); sandbox_common(); if (unshare(CLONE_NEWNET)) { } loop(); exit(1); } void loop(void) { *(uint8_t*)0x20000000 = 0x12; *(uint8_t*)0x20000001 = 1; *(uint16_t*)0x20000002 = 0; *(uint8_t*)0x20000004 = 0x18; *(uint8_t*)0x20000005 = 0xc; *(uint8_t*)0x20000006 = 0x85; *(uint8_t*)0x20000007 = 8; *(uint16_t*)0x20000008 = 0x50d; *(uint16_t*)0x2000000a = 0x945a; *(uint16_t*)0x2000000c = 0xf1a1; *(uint8_t*)0x2000000e = 0; *(uint8_t*)0x2000000f = 0; *(uint8_t*)0x20000010 = 0; *(uint8_t*)0x20000011 = 1; *(uint8_t*)0x20000012 = 9; *(uint8_t*)0x20000013 = 2; *(uint16_t*)0x20000014 = 0x12; *(uint8_t*)0x20000016 = 1; *(uint8_t*)0x20000017 = 0; *(uint8_t*)0x20000018 = 0; *(uint8_t*)0x20000019 = 0; *(uint8_t*)0x2000001a = 0; *(uint8_t*)0x2000001b = 9; *(uint8_t*)0x2000001c = 4; *(uint8_t*)0x2000001d = 0xd4; *(uint8_t*)0x2000001e = 0; *(uint8_t*)0x2000001f = 0; *(uint8_t*)0x20000020 = 0x2c; *(uint8_t*)0x20000021 = 0x4a; *(uint8_t*)0x20000022 = 0xb6; *(uint8_t*)0x20000023 = 0; syz_usb_connect(1, 0x24, 0x20000000, 0); } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); do_sandbox_none(); return 0; }