// https://syzkaller.appspot.com/bug?id=19fb554305ab534dc6183a3986d5fc1579be1677 // 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 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); } static volatile long syz_usb_disconnect(volatile long a0) { int fd = a0; int rv = close(fd); sleep_ms(200); return rv; } static long syz_open_dev(volatile long a0, volatile long a1, volatile long a2) { if (a0 == 0xc || a0 == 0xb) { char buf[128]; sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1, (uint8_t)a2); return open(buf, O_RDWR, 0); } else { unsigned long nb = a1; char buf[1024]; char* hash; strncpy(buf, (char*)a0, sizeof(buf) - 1); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(nb % 10); nb /= 10; } return open(buf, a2, 0); } } #define noinline __attribute__((noinline)) #define __no_stack_protector #define __addrspace_guest #define GUEST_CODE \ __attribute__((section("guest"))) __no_stack_protector __addrspace_guest extern char *__start_guest, *__stop_guest; #define X86_ADDR_TEXT 0x0000 #define X86_ADDR_PD_IOAPIC 0x0000 #define X86_ADDR_GDT 0x1000 #define X86_ADDR_LDT 0x1800 #define X86_ADDR_PML4 0x2000 #define X86_ADDR_PDP 0x3000 #define X86_ADDR_PD 0x4000 #define X86_ADDR_STACK0 0x0f80 #define X86_ADDR_VAR_HLT 0x2800 #define X86_ADDR_VAR_SYSRET 0x2808 #define X86_ADDR_VAR_SYSEXIT 0x2810 #define X86_ADDR_VAR_IDT 0x3800 #define X86_ADDR_VAR_TSS64 0x3a00 #define X86_ADDR_VAR_TSS64_CPL3 0x3c00 #define X86_ADDR_VAR_TSS16 0x3d00 #define X86_ADDR_VAR_TSS16_2 0x3e00 #define X86_ADDR_VAR_TSS16_CPL3 0x3f00 #define X86_ADDR_VAR_TSS32 0x4800 #define X86_ADDR_VAR_TSS32_2 0x4a00 #define X86_ADDR_VAR_TSS32_CPL3 0x4c00 #define X86_ADDR_VAR_TSS32_VM86 0x4e00 #define X86_ADDR_VAR_VMXON_PTR 0x5f00 #define X86_ADDR_VAR_VMCS_PTR 0x5f08 #define X86_ADDR_VAR_VMEXIT_PTR 0x5f10 #define X86_ADDR_VAR_VMWRITE_FLD 0x5f18 #define X86_ADDR_VAR_VMWRITE_VAL 0x5f20 #define X86_ADDR_VAR_VMXON 0x6000 #define X86_ADDR_VAR_VMCS 0x7000 #define X86_ADDR_VAR_VMEXIT_CODE 0x9000 #define X86_ADDR_VAR_USER_CODE 0x9100 #define X86_ADDR_VAR_USER_CODE2 0x9120 #define X86_SYZOS_ADDR_ZERO 0x0 #define X86_SYZOS_ADDR_GDT 0x1000 #define X86_SYZOS_ADDR_PML4 0x2000 #define X86_SYZOS_ADDR_PDP 0x3000 #define X86_SYZOS_ADDR_PT_POOL 0x5000 #define X86_SYZOS_ADDR_VAR_IDT 0x25000 #define X86_SYZOS_ADDR_SMRAM 0x30000 #define X86_SYZOS_ADDR_EXIT 0x40000 #define X86_SYZOS_ADDR_UEXIT (X86_SYZOS_ADDR_EXIT + 256) #define X86_SYZOS_ADDR_DIRTY_PAGES 0x41000 #define X86_SYZOS_ADDR_USER_CODE 0x50000 #define SYZOS_ADDR_EXECUTOR_CODE 0x54000 #define X86_SYZOS_ADDR_SCRATCH_CODE 0x58000 #define X86_SYZOS_ADDR_STACK_BOTTOM 0x90000 #define X86_SYZOS_ADDR_STACK0 0x90f80 #define X86_SYZOS_ADDR_UNUSED 0x200000 #define X86_SYZOS_ADDR_IOAPIC 0xfec00000 #define X86_SYZOS_SEL_CODE 0x8 #define X86_SYZOS_SEL_DATA 0x10 #define X86_CR0_PE 1ULL #define X86_CR0_MP (1ULL << 1) #define X86_CR0_EM (1ULL << 2) #define X86_CR0_TS (1ULL << 3) #define X86_CR0_ET (1ULL << 4) #define X86_CR0_NE (1ULL << 5) #define X86_CR0_WP (1ULL << 16) #define X86_CR0_AM (1ULL << 18) #define X86_CR0_NW (1ULL << 29) #define X86_CR0_CD (1ULL << 30) #define X86_CR0_PG (1ULL << 31) #define X86_CR4_VME 1ULL #define X86_CR4_PVI (1ULL << 1) #define X86_CR4_TSD (1ULL << 2) #define X86_CR4_DE (1ULL << 3) #define X86_CR4_PSE (1ULL << 4) #define X86_CR4_PAE (1ULL << 5) #define X86_CR4_MCE (1ULL << 6) #define X86_CR4_PGE (1ULL << 7) #define X86_CR4_PCE (1ULL << 8) #define X86_CR4_OSFXSR (1ULL << 8) #define X86_CR4_OSXMMEXCPT (1ULL << 10) #define X86_CR4_UMIP (1ULL << 11) #define X86_CR4_VMXE (1ULL << 13) #define X86_CR4_SMXE (1ULL << 14) #define X86_CR4_FSGSBASE (1ULL << 16) #define X86_CR4_PCIDE (1ULL << 17) #define X86_CR4_OSXSAVE (1ULL << 18) #define X86_CR4_SMEP (1ULL << 20) #define X86_CR4_SMAP (1ULL << 21) #define X86_CR4_PKE (1ULL << 22) #define X86_EFER_SCE 1ULL #define X86_EFER_LME (1ULL << 8) #define X86_EFER_LMA (1ULL << 10) #define X86_EFER_NXE (1ULL << 11) #define X86_EFER_SVME (1ULL << 12) #define X86_EFER_LMSLE (1ULL << 13) #define X86_EFER_FFXSR (1ULL << 14) #define X86_EFER_TCE (1ULL << 15) #define X86_PDE32_PRESENT 1UL #define X86_PDE32_RW (1UL << 1) #define X86_PDE32_USER (1UL << 2) #define X86_PDE32_PS (1UL << 7) #define X86_PDE64_PRESENT 1 #define X86_PDE64_RW (1ULL << 1) #define X86_PDE64_USER (1ULL << 2) #define X86_PDE64_ACCESSED (1ULL << 5) #define X86_PDE64_DIRTY (1ULL << 6) #define X86_PDE64_PS (1ULL << 7) #define X86_PDE64_G (1ULL << 8) #define X86_SEL_LDT (1 << 3) #define X86_SEL_CS16 (2 << 3) #define X86_SEL_DS16 (3 << 3) #define X86_SEL_CS16_CPL3 ((4 << 3) + 3) #define X86_SEL_DS16_CPL3 ((5 << 3) + 3) #define X86_SEL_CS32 (6 << 3) #define X86_SEL_DS32 (7 << 3) #define X86_SEL_CS32_CPL3 ((8 << 3) + 3) #define X86_SEL_DS32_CPL3 ((9 << 3) + 3) #define X86_SEL_CS64 (10 << 3) #define X86_SEL_DS64 (11 << 3) #define X86_SEL_CS64_CPL3 ((12 << 3) + 3) #define X86_SEL_DS64_CPL3 ((13 << 3) + 3) #define X86_SEL_CGATE16 (14 << 3) #define X86_SEL_TGATE16 (15 << 3) #define X86_SEL_CGATE32 (16 << 3) #define X86_SEL_TGATE32 (17 << 3) #define X86_SEL_CGATE64 (18 << 3) #define X86_SEL_CGATE64_HI (19 << 3) #define X86_SEL_TSS16 (20 << 3) #define X86_SEL_TSS16_2 (21 << 3) #define X86_SEL_TSS16_CPL3 ((22 << 3) + 3) #define X86_SEL_TSS32 (23 << 3) #define X86_SEL_TSS32_2 (24 << 3) #define X86_SEL_TSS32_CPL3 ((25 << 3) + 3) #define X86_SEL_TSS32_VM86 (26 << 3) #define X86_SEL_TSS64 (27 << 3) #define X86_SEL_TSS64_HI (28 << 3) #define X86_SEL_TSS64_CPL3 ((29 << 3) + 3) #define X86_SEL_TSS64_CPL3_HI (30 << 3) #define X86_MSR_IA32_FEATURE_CONTROL 0x3a #define X86_MSR_IA32_VMX_BASIC 0x480 #define X86_MSR_IA32_SMBASE 0x9e #define X86_MSR_IA32_SYSENTER_CS 0x174 #define X86_MSR_IA32_SYSENTER_ESP 0x175 #define X86_MSR_IA32_SYSENTER_EIP 0x176 #define X86_MSR_IA32_STAR 0xC0000081 #define X86_MSR_IA32_LSTAR 0xC0000082 #define X86_MSR_IA32_VMX_PROCBASED_CTLS2 0x48B #define X86_NEXT_INSN $0xbadc0de #define X86_PREFIX_SIZE 0xba1d #define KVM_MAX_VCPU 4 #define KVM_PAGE_SIZE (1 << 12) #define KVM_GUEST_PAGES 1024 #define KVM_GUEST_MEM_SIZE (KVM_GUEST_PAGES * KVM_PAGE_SIZE) #define SZ_4K 0x00001000 #define SZ_64K 0x00010000 #define GENMASK_ULL(h, l) \ (((~0ULL) - (1ULL << (l)) + 1ULL) & (~0ULL >> (63 - (h)))) extern char* __start_guest; static inline uintptr_t executor_fn_guest_addr(void* fn) { volatile uintptr_t start = (uintptr_t)&__start_guest; volatile uintptr_t offset = SYZOS_ADDR_EXECUTOR_CODE; return (uintptr_t)fn - start + offset; } #define noinline __attribute__((noinline)) #define __no_stack_protector #define __addrspace_guest #define GUEST_CODE \ __attribute__((section("guest"))) __no_stack_protector __addrspace_guest extern char *__start_guest, *__stop_guest; #define X86_ADDR_TEXT 0x0000 #define X86_ADDR_PD_IOAPIC 0x0000 #define X86_ADDR_GDT 0x1000 #define X86_ADDR_LDT 0x1800 #define X86_ADDR_PML4 0x2000 #define X86_ADDR_PDP 0x3000 #define X86_ADDR_PD 0x4000 #define X86_ADDR_STACK0 0x0f80 #define X86_ADDR_VAR_HLT 0x2800 #define X86_ADDR_VAR_SYSRET 0x2808 #define X86_ADDR_VAR_SYSEXIT 0x2810 #define X86_ADDR_VAR_IDT 0x3800 #define X86_ADDR_VAR_TSS64 0x3a00 #define X86_ADDR_VAR_TSS64_CPL3 0x3c00 #define X86_ADDR_VAR_TSS16 0x3d00 #define X86_ADDR_VAR_TSS16_2 0x3e00 #define X86_ADDR_VAR_TSS16_CPL3 0x3f00 #define X86_ADDR_VAR_TSS32 0x4800 #define X86_ADDR_VAR_TSS32_2 0x4a00 #define X86_ADDR_VAR_TSS32_CPL3 0x4c00 #define X86_ADDR_VAR_TSS32_VM86 0x4e00 #define X86_ADDR_VAR_VMXON_PTR 0x5f00 #define X86_ADDR_VAR_VMCS_PTR 0x5f08 #define X86_ADDR_VAR_VMEXIT_PTR 0x5f10 #define X86_ADDR_VAR_VMWRITE_FLD 0x5f18 #define X86_ADDR_VAR_VMWRITE_VAL 0x5f20 #define X86_ADDR_VAR_VMXON 0x6000 #define X86_ADDR_VAR_VMCS 0x7000 #define X86_ADDR_VAR_VMEXIT_CODE 0x9000 #define X86_ADDR_VAR_USER_CODE 0x9100 #define X86_ADDR_VAR_USER_CODE2 0x9120 #define X86_SYZOS_ADDR_ZERO 0x0 #define X86_SYZOS_ADDR_GDT 0x1000 #define X86_SYZOS_ADDR_PML4 0x2000 #define X86_SYZOS_ADDR_PDP 0x3000 #define X86_SYZOS_ADDR_PT_POOL 0x5000 #define X86_SYZOS_ADDR_VAR_IDT 0x25000 #define X86_SYZOS_ADDR_SMRAM 0x30000 #define X86_SYZOS_ADDR_EXIT 0x40000 #define X86_SYZOS_ADDR_UEXIT (X86_SYZOS_ADDR_EXIT + 256) #define X86_SYZOS_ADDR_DIRTY_PAGES 0x41000 #define X86_SYZOS_ADDR_USER_CODE 0x50000 #define SYZOS_ADDR_EXECUTOR_CODE 0x54000 #define X86_SYZOS_ADDR_SCRATCH_CODE 0x58000 #define X86_SYZOS_ADDR_STACK_BOTTOM 0x90000 #define X86_SYZOS_ADDR_STACK0 0x90f80 #define X86_SYZOS_ADDR_UNUSED 0x200000 #define X86_SYZOS_ADDR_IOAPIC 0xfec00000 #define X86_SYZOS_SEL_CODE 0x8 #define X86_SYZOS_SEL_DATA 0x10 #define X86_CR0_PE 1ULL #define X86_CR0_MP (1ULL << 1) #define X86_CR0_EM (1ULL << 2) #define X86_CR0_TS (1ULL << 3) #define X86_CR0_ET (1ULL << 4) #define X86_CR0_NE (1ULL << 5) #define X86_CR0_WP (1ULL << 16) #define X86_CR0_AM (1ULL << 18) #define X86_CR0_NW (1ULL << 29) #define X86_CR0_CD (1ULL << 30) #define X86_CR0_PG (1ULL << 31) #define X86_CR4_VME 1ULL #define X86_CR4_PVI (1ULL << 1) #define X86_CR4_TSD (1ULL << 2) #define X86_CR4_DE (1ULL << 3) #define X86_CR4_PSE (1ULL << 4) #define X86_CR4_PAE (1ULL << 5) #define X86_CR4_MCE (1ULL << 6) #define X86_CR4_PGE (1ULL << 7) #define X86_CR4_PCE (1ULL << 8) #define X86_CR4_OSFXSR (1ULL << 8) #define X86_CR4_OSXMMEXCPT (1ULL << 10) #define X86_CR4_UMIP (1ULL << 11) #define X86_CR4_VMXE (1ULL << 13) #define X86_CR4_SMXE (1ULL << 14) #define X86_CR4_FSGSBASE (1ULL << 16) #define X86_CR4_PCIDE (1ULL << 17) #define X86_CR4_OSXSAVE (1ULL << 18) #define X86_CR4_SMEP (1ULL << 20) #define X86_CR4_SMAP (1ULL << 21) #define X86_CR4_PKE (1ULL << 22) #define X86_EFER_SCE 1ULL #define X86_EFER_LME (1ULL << 8) #define X86_EFER_LMA (1ULL << 10) #define X86_EFER_NXE (1ULL << 11) #define X86_EFER_SVME (1ULL << 12) #define X86_EFER_LMSLE (1ULL << 13) #define X86_EFER_FFXSR (1ULL << 14) #define X86_EFER_TCE (1ULL << 15) #define X86_PDE32_PRESENT 1UL #define X86_PDE32_RW (1UL << 1) #define X86_PDE32_USER (1UL << 2) #define X86_PDE32_PS (1UL << 7) #define X86_PDE64_PRESENT 1 #define X86_PDE64_RW (1ULL << 1) #define X86_PDE64_USER (1ULL << 2) #define X86_PDE64_ACCESSED (1ULL << 5) #define X86_PDE64_DIRTY (1ULL << 6) #define X86_PDE64_PS (1ULL << 7) #define X86_PDE64_G (1ULL << 8) #define X86_SEL_LDT (1 << 3) #define X86_SEL_CS16 (2 << 3) #define X86_SEL_DS16 (3 << 3) #define X86_SEL_CS16_CPL3 ((4 << 3) + 3) #define X86_SEL_DS16_CPL3 ((5 << 3) + 3) #define X86_SEL_CS32 (6 << 3) #define X86_SEL_DS32 (7 << 3) #define X86_SEL_CS32_CPL3 ((8 << 3) + 3) #define X86_SEL_DS32_CPL3 ((9 << 3) + 3) #define X86_SEL_CS64 (10 << 3) #define X86_SEL_DS64 (11 << 3) #define X86_SEL_CS64_CPL3 ((12 << 3) + 3) #define X86_SEL_DS64_CPL3 ((13 << 3) + 3) #define X86_SEL_CGATE16 (14 << 3) #define X86_SEL_TGATE16 (15 << 3) #define X86_SEL_CGATE32 (16 << 3) #define X86_SEL_TGATE32 (17 << 3) #define X86_SEL_CGATE64 (18 << 3) #define X86_SEL_CGATE64_HI (19 << 3) #define X86_SEL_TSS16 (20 << 3) #define X86_SEL_TSS16_2 (21 << 3) #define X86_SEL_TSS16_CPL3 ((22 << 3) + 3) #define X86_SEL_TSS32 (23 << 3) #define X86_SEL_TSS32_2 (24 << 3) #define X86_SEL_TSS32_CPL3 ((25 << 3) + 3) #define X86_SEL_TSS32_VM86 (26 << 3) #define X86_SEL_TSS64 (27 << 3) #define X86_SEL_TSS64_HI (28 << 3) #define X86_SEL_TSS64_CPL3 ((29 << 3) + 3) #define X86_SEL_TSS64_CPL3_HI (30 << 3) #define X86_MSR_IA32_FEATURE_CONTROL 0x3a #define X86_MSR_IA32_VMX_BASIC 0x480 #define X86_MSR_IA32_SMBASE 0x9e #define X86_MSR_IA32_SYSENTER_CS 0x174 #define X86_MSR_IA32_SYSENTER_ESP 0x175 #define X86_MSR_IA32_SYSENTER_EIP 0x176 #define X86_MSR_IA32_STAR 0xC0000081 #define X86_MSR_IA32_LSTAR 0xC0000082 #define X86_MSR_IA32_VMX_PROCBASED_CTLS2 0x48B #define X86_NEXT_INSN $0xbadc0de #define X86_PREFIX_SIZE 0xba1d #define KVM_MAX_VCPU 4 #define KVM_PAGE_SIZE (1 << 12) #define KVM_GUEST_PAGES 1024 #define KVM_GUEST_MEM_SIZE (KVM_GUEST_PAGES * KVM_PAGE_SIZE) #define SZ_4K 0x00001000 #define SZ_64K 0x00010000 #define GENMASK_ULL(h, l) \ (((~0ULL) - (1ULL << (l)) + 1ULL) & (~0ULL >> (63 - (h)))) typedef enum { SYZOS_API_UEXIT = 0, SYZOS_API_CODE = 10, SYZOS_API_CPUID = 20, SYZOS_API_WRMSR = 30, SYZOS_API_RDMSR = 50, SYZOS_API_WR_CRN = 70, SYZOS_API_WR_DRN = 110, SYZOS_API_IN_DX = 130, SYZOS_API_OUT_DX = 170, SYZOS_API_SET_IRQ_HANDLER = 190, SYZOS_API_STOP, } syzos_api_id; struct api_call_header { uint64_t call; uint64_t size; }; struct api_call_uexit { struct api_call_header header; uint64_t exit_code; }; struct api_call_code { struct api_call_header header; uint8_t insns[]; }; struct api_call_cpuid { struct api_call_header header; uint32_t eax; uint32_t ecx; }; struct api_call_1 { struct api_call_header header; uint64_t arg; }; struct api_call_2 { struct api_call_header header; uint64_t args[2]; }; struct api_call_3 { struct api_call_header header; uint64_t args[3]; }; GUEST_CODE static void guest_uexit(uint64_t exit_code); GUEST_CODE static void guest_execute_code(uint8_t* insns, uint64_t size); GUEST_CODE static void guest_handle_cpuid(uint32_t eax, uint32_t ecx); GUEST_CODE static void guest_handle_wrmsr(uint64_t reg, uint64_t val); GUEST_CODE static void guest_handle_rdmsr(uint64_t reg); GUEST_CODE static void guest_handle_wr_crn(struct api_call_2* cmd); GUEST_CODE static void guest_handle_wr_drn(struct api_call_2* cmd); GUEST_CODE static void guest_handle_in_dx(struct api_call_2* cmd); GUEST_CODE static void guest_handle_out_dx(struct api_call_3* cmd); GUEST_CODE static void guest_handle_set_irq_handler(struct api_call_2* cmd); typedef enum { UEXIT_END = (uint64_t)-1, UEXIT_IRQ = (uint64_t)-2, UEXIT_ASSERT = (uint64_t)-3, } uexit_code; __attribute__((naked)) GUEST_CODE static void dummy_null_handler() { asm("iretq"); } __attribute__((naked)) GUEST_CODE static void uexit_irq_handler() { asm volatile(R"( movq $-2, %rdi call guest_uexit iretq )"); } __attribute__((used)) GUEST_CODE static void guest_main(uint64_t size, uint64_t cpu) { uint64_t addr = X86_SYZOS_ADDR_USER_CODE + cpu * KVM_PAGE_SIZE; while (size >= sizeof(struct api_call_header)) { struct api_call_header* cmd = (struct api_call_header*)addr; if (cmd->call >= SYZOS_API_STOP) return; if (cmd->size > size) return; volatile uint64_t call = cmd->call; if (call == SYZOS_API_UEXIT) { struct api_call_uexit* ucmd = (struct api_call_uexit*)cmd; guest_uexit(ucmd->exit_code); } else if (call == SYZOS_API_CODE) { struct api_call_code* ccmd = (struct api_call_code*)cmd; guest_execute_code(ccmd->insns, cmd->size - sizeof(struct api_call_header)); } else if (call == SYZOS_API_CPUID) { struct api_call_cpuid* ccmd = (struct api_call_cpuid*)cmd; guest_handle_cpuid(ccmd->eax, ccmd->ecx); } else if (call == SYZOS_API_WRMSR) { struct api_call_2* ccmd = (struct api_call_2*)cmd; guest_handle_wrmsr(ccmd->args[0], ccmd->args[1]); } else if (call == SYZOS_API_RDMSR) { struct api_call_1* ccmd = (struct api_call_1*)cmd; guest_handle_rdmsr(ccmd->arg); } else if (call == SYZOS_API_WR_CRN) { guest_handle_wr_crn((struct api_call_2*)cmd); } else if (call == SYZOS_API_WR_DRN) { guest_handle_wr_drn((struct api_call_2*)cmd); } else if (call == SYZOS_API_IN_DX) { guest_handle_in_dx((struct api_call_2*)cmd); } else if (call == SYZOS_API_OUT_DX) { guest_handle_out_dx((struct api_call_3*)cmd); } else if (call == SYZOS_API_SET_IRQ_HANDLER) { guest_handle_set_irq_handler((struct api_call_2*)cmd); } addr += cmd->size; size -= cmd->size; }; guest_uexit((uint64_t)-1); } GUEST_CODE static noinline void guest_execute_code(uint8_t* insns, uint64_t size) { volatile void (*fn)() = (volatile void (*)())insns; fn(); } __attribute__((used)) GUEST_CODE static noinline void guest_uexit(uint64_t exit_code) { volatile uint64_t* ptr = (volatile uint64_t*)X86_SYZOS_ADDR_UEXIT; *ptr = exit_code; } GUEST_CODE static noinline void guest_handle_cpuid(uint32_t eax, uint32_t ecx) { asm volatile("cpuid\n" : : "a"(eax), "c"(ecx) : "rbx", "rdx"); } GUEST_CODE static noinline void guest_handle_wrmsr(uint64_t reg, uint64_t val) { asm volatile("wrmsr" : : "c"(reg), "a"((uint32_t)val), "d"((uint32_t)(val >> 32)) : "memory"); } GUEST_CODE static noinline void guest_handle_rdmsr(uint64_t reg) { uint32_t low = 0, high = 0; asm volatile("rdmsr" : "=a"(low), "=d"(high) : "c"(reg) :); } GUEST_CODE static noinline void guest_handle_wr_crn(struct api_call_2* cmd) { uint64_t value = cmd->args[1]; volatile uint64_t reg = cmd->args[0]; if (reg == 0) { asm volatile("movq %0, %%cr0" ::"r"(value) : "memory"); return; } if (reg == 2) { asm volatile("movq %0, %%cr2" ::"r"(value) : "memory"); return; } if (reg == 3) { asm volatile("movq %0, %%cr3" ::"r"(value) : "memory"); return; } if (reg == 4) { asm volatile("movq %0, %%cr4" ::"r"(value) : "memory"); return; } if (reg == 8) { asm volatile("movq %0, %%cr8" ::"r"(value) : "memory"); return; } } GUEST_CODE static noinline void guest_handle_wr_drn(struct api_call_2* cmd) { uint64_t value = cmd->args[1]; volatile uint64_t reg = cmd->args[0]; if (reg == 0) { asm volatile("movq %0, %%dr0" ::"r"(value) : "memory"); return; } if (reg == 1) { asm volatile("movq %0, %%dr1" ::"r"(value) : "memory"); return; } if (reg == 2) { asm volatile("movq %0, %%dr2" ::"r"(value) : "memory"); return; } if (reg == 3) { asm volatile("movq %0, %%dr3" ::"r"(value) : "memory"); return; } if (reg == 4) { asm volatile("movq %0, %%dr4" ::"r"(value) : "memory"); return; } if (reg == 5) { asm volatile("movq %0, %%dr5" ::"r"(value) : "memory"); return; } if (reg == 6) { asm volatile("movq %0, %%dr6" ::"r"(value) : "memory"); return; } if (reg == 7) { asm volatile("movq %0, %%dr7" ::"r"(value) : "memory"); return; } } GUEST_CODE static noinline void guest_handle_in_dx(struct api_call_2* cmd) { uint16_t port = cmd->args[0]; volatile int size = cmd->args[1]; if (size == 1) { uint8_t unused; asm volatile("inb %1, %0" : "=a"(unused) : "d"(port)); return; } if (size == 2) { uint16_t unused; asm volatile("inw %1, %0" : "=a"(unused) : "d"(port)); return; } if (size == 4) { uint32_t unused; asm volatile("inl %1, %0" : "=a"(unused) : "d"(port)); } return; } GUEST_CODE static noinline void guest_handle_out_dx(struct api_call_3* cmd) { uint16_t port = cmd->args[0]; volatile int size = cmd->args[1]; uint32_t data = (uint32_t)cmd->args[2]; if (size == 1) { asm volatile("outb %b0, %w1" ::"a"(data), "d"(port)); return; } if (size == 2) { asm volatile("outw %w0, %w1" ::"a"(data), "d"(port)); return; } if (size == 4) { asm volatile("outl %k0, %w1" ::"a"(data), "d"(port)); return; } } struct idt_entry_64 { uint16_t offset_low; uint16_t selector; uint8_t ist; uint8_t type_attr; uint16_t offset_mid; uint32_t offset_high; uint32_t reserved; } __attribute__((packed)); GUEST_CODE static void set_idt_gate(uint8_t vector, uint64_t handler) { volatile struct idt_entry_64* idt = (volatile struct idt_entry_64*)(X86_SYZOS_ADDR_VAR_IDT); volatile struct idt_entry_64* idt_entry = &idt[vector]; idt_entry->offset_low = (uint16_t)handler; idt_entry->offset_mid = (uint16_t)(handler >> 16); idt_entry->offset_high = (uint32_t)(handler >> 32); idt_entry->selector = X86_SYZOS_SEL_CODE; idt_entry->type_attr = 0x8E; idt_entry->ist = 0; idt_entry->reserved = 0; } GUEST_CODE static noinline void guest_handle_set_irq_handler(struct api_call_2* cmd) { uint8_t vector = (uint8_t)cmd->args[0]; uint64_t type = cmd->args[1]; volatile uint64_t handler_addr = 0; if (type == 1) handler_addr = executor_fn_guest_addr(dummy_null_handler); else if (type == 2) handler_addr = executor_fn_guest_addr(uexit_irq_handler); set_idt_gate(vector, handler_addr); } #define X86_ADDR_TEXT 0x0000 #define X86_ADDR_PD_IOAPIC 0x0000 #define X86_ADDR_GDT 0x1000 #define X86_ADDR_LDT 0x1800 #define X86_ADDR_PML4 0x2000 #define X86_ADDR_PDP 0x3000 #define X86_ADDR_PD 0x4000 #define X86_ADDR_STACK0 0x0f80 #define X86_ADDR_VAR_HLT 0x2800 #define X86_ADDR_VAR_SYSRET 0x2808 #define X86_ADDR_VAR_SYSEXIT 0x2810 #define X86_ADDR_VAR_IDT 0x3800 #define X86_ADDR_VAR_TSS64 0x3a00 #define X86_ADDR_VAR_TSS64_CPL3 0x3c00 #define X86_ADDR_VAR_TSS16 0x3d00 #define X86_ADDR_VAR_TSS16_2 0x3e00 #define X86_ADDR_VAR_TSS16_CPL3 0x3f00 #define X86_ADDR_VAR_TSS32 0x4800 #define X86_ADDR_VAR_TSS32_2 0x4a00 #define X86_ADDR_VAR_TSS32_CPL3 0x4c00 #define X86_ADDR_VAR_TSS32_VM86 0x4e00 #define X86_ADDR_VAR_VMXON_PTR 0x5f00 #define X86_ADDR_VAR_VMCS_PTR 0x5f08 #define X86_ADDR_VAR_VMEXIT_PTR 0x5f10 #define X86_ADDR_VAR_VMWRITE_FLD 0x5f18 #define X86_ADDR_VAR_VMWRITE_VAL 0x5f20 #define X86_ADDR_VAR_VMXON 0x6000 #define X86_ADDR_VAR_VMCS 0x7000 #define X86_ADDR_VAR_VMEXIT_CODE 0x9000 #define X86_ADDR_VAR_USER_CODE 0x9100 #define X86_ADDR_VAR_USER_CODE2 0x9120 #define X86_SYZOS_ADDR_ZERO 0x0 #define X86_SYZOS_ADDR_GDT 0x1000 #define X86_SYZOS_ADDR_PML4 0x2000 #define X86_SYZOS_ADDR_PDP 0x3000 #define X86_SYZOS_ADDR_PT_POOL 0x5000 #define X86_SYZOS_ADDR_VAR_IDT 0x25000 #define X86_SYZOS_ADDR_SMRAM 0x30000 #define X86_SYZOS_ADDR_EXIT 0x40000 #define X86_SYZOS_ADDR_UEXIT (X86_SYZOS_ADDR_EXIT + 256) #define X86_SYZOS_ADDR_DIRTY_PAGES 0x41000 #define X86_SYZOS_ADDR_USER_CODE 0x50000 #define SYZOS_ADDR_EXECUTOR_CODE 0x54000 #define X86_SYZOS_ADDR_SCRATCH_CODE 0x58000 #define X86_SYZOS_ADDR_STACK_BOTTOM 0x90000 #define X86_SYZOS_ADDR_STACK0 0x90f80 #define X86_SYZOS_ADDR_UNUSED 0x200000 #define X86_SYZOS_ADDR_IOAPIC 0xfec00000 #define X86_SYZOS_SEL_CODE 0x8 #define X86_SYZOS_SEL_DATA 0x10 #define X86_CR0_PE 1ULL #define X86_CR0_MP (1ULL << 1) #define X86_CR0_EM (1ULL << 2) #define X86_CR0_TS (1ULL << 3) #define X86_CR0_ET (1ULL << 4) #define X86_CR0_NE (1ULL << 5) #define X86_CR0_WP (1ULL << 16) #define X86_CR0_AM (1ULL << 18) #define X86_CR0_NW (1ULL << 29) #define X86_CR0_CD (1ULL << 30) #define X86_CR0_PG (1ULL << 31) #define X86_CR4_VME 1ULL #define X86_CR4_PVI (1ULL << 1) #define X86_CR4_TSD (1ULL << 2) #define X86_CR4_DE (1ULL << 3) #define X86_CR4_PSE (1ULL << 4) #define X86_CR4_PAE (1ULL << 5) #define X86_CR4_MCE (1ULL << 6) #define X86_CR4_PGE (1ULL << 7) #define X86_CR4_PCE (1ULL << 8) #define X86_CR4_OSFXSR (1ULL << 8) #define X86_CR4_OSXMMEXCPT (1ULL << 10) #define X86_CR4_UMIP (1ULL << 11) #define X86_CR4_VMXE (1ULL << 13) #define X86_CR4_SMXE (1ULL << 14) #define X86_CR4_FSGSBASE (1ULL << 16) #define X86_CR4_PCIDE (1ULL << 17) #define X86_CR4_OSXSAVE (1ULL << 18) #define X86_CR4_SMEP (1ULL << 20) #define X86_CR4_SMAP (1ULL << 21) #define X86_CR4_PKE (1ULL << 22) #define X86_EFER_SCE 1ULL #define X86_EFER_LME (1ULL << 8) #define X86_EFER_LMA (1ULL << 10) #define X86_EFER_NXE (1ULL << 11) #define X86_EFER_SVME (1ULL << 12) #define X86_EFER_LMSLE (1ULL << 13) #define X86_EFER_FFXSR (1ULL << 14) #define X86_EFER_TCE (1ULL << 15) #define X86_PDE32_PRESENT 1UL #define X86_PDE32_RW (1UL << 1) #define X86_PDE32_USER (1UL << 2) #define X86_PDE32_PS (1UL << 7) #define X86_PDE64_PRESENT 1 #define X86_PDE64_RW (1ULL << 1) #define X86_PDE64_USER (1ULL << 2) #define X86_PDE64_ACCESSED (1ULL << 5) #define X86_PDE64_DIRTY (1ULL << 6) #define X86_PDE64_PS (1ULL << 7) #define X86_PDE64_G (1ULL << 8) #define X86_SEL_LDT (1 << 3) #define X86_SEL_CS16 (2 << 3) #define X86_SEL_DS16 (3 << 3) #define X86_SEL_CS16_CPL3 ((4 << 3) + 3) #define X86_SEL_DS16_CPL3 ((5 << 3) + 3) #define X86_SEL_CS32 (6 << 3) #define X86_SEL_DS32 (7 << 3) #define X86_SEL_CS32_CPL3 ((8 << 3) + 3) #define X86_SEL_DS32_CPL3 ((9 << 3) + 3) #define X86_SEL_CS64 (10 << 3) #define X86_SEL_DS64 (11 << 3) #define X86_SEL_CS64_CPL3 ((12 << 3) + 3) #define X86_SEL_DS64_CPL3 ((13 << 3) + 3) #define X86_SEL_CGATE16 (14 << 3) #define X86_SEL_TGATE16 (15 << 3) #define X86_SEL_CGATE32 (16 << 3) #define X86_SEL_TGATE32 (17 << 3) #define X86_SEL_CGATE64 (18 << 3) #define X86_SEL_CGATE64_HI (19 << 3) #define X86_SEL_TSS16 (20 << 3) #define X86_SEL_TSS16_2 (21 << 3) #define X86_SEL_TSS16_CPL3 ((22 << 3) + 3) #define X86_SEL_TSS32 (23 << 3) #define X86_SEL_TSS32_2 (24 << 3) #define X86_SEL_TSS32_CPL3 ((25 << 3) + 3) #define X86_SEL_TSS32_VM86 (26 << 3) #define X86_SEL_TSS64 (27 << 3) #define X86_SEL_TSS64_HI (28 << 3) #define X86_SEL_TSS64_CPL3 ((29 << 3) + 3) #define X86_SEL_TSS64_CPL3_HI (30 << 3) #define X86_MSR_IA32_FEATURE_CONTROL 0x3a #define X86_MSR_IA32_VMX_BASIC 0x480 #define X86_MSR_IA32_SMBASE 0x9e #define X86_MSR_IA32_SYSENTER_CS 0x174 #define X86_MSR_IA32_SYSENTER_ESP 0x175 #define X86_MSR_IA32_SYSENTER_EIP 0x176 #define X86_MSR_IA32_STAR 0xC0000081 #define X86_MSR_IA32_LSTAR 0xC0000082 #define X86_MSR_IA32_VMX_PROCBASED_CTLS2 0x48B #define X86_NEXT_INSN $0xbadc0de #define X86_PREFIX_SIZE 0xba1d #define KVM_MAX_VCPU 4 #define KVM_PAGE_SIZE (1 << 12) #define KVM_GUEST_PAGES 1024 #define KVM_GUEST_MEM_SIZE (KVM_GUEST_PAGES * KVM_PAGE_SIZE) #define SZ_4K 0x00001000 #define SZ_64K 0x00010000 #define GENMASK_ULL(h, l) \ (((~0ULL) - (1ULL << (l)) + 1ULL) & (~0ULL >> (63 - (h)))) const char kvm_asm16_cpl3[] = "\x0f\x20\xc0\x66\x83\xc8\x01\x0f\x22\xc0\xb8\xa0\x00\x0f\x00\xd8\xb8\x2b" "\x00\x8e\xd8\x8e\xc0\x8e\xe0\x8e\xe8\xbc\x00\x01\xc7\x06\x00\x01\x1d\xba" "\xc7\x06\x02\x01\x23\x00\xc7\x06\x04\x01\x00\x01\xc7\x06\x06\x01\x2b\x00" "\xcb"; const char kvm_asm32_paged[] = "\x0f\x20\xc0\x0d\x00\x00\x00\x80\x0f\x22\xc0"; const char kvm_asm32_vm86[] = "\x66\xb8\xb8\x00\x0f\x00\xd8\xea\x00\x00\x00\x00\xd0\x00"; const char kvm_asm32_paged_vm86[] = "\x0f\x20\xc0\x0d\x00\x00\x00\x80\x0f\x22\xc0\x66\xb8\xb8\x00\x0f\x00\xd8" "\xea\x00\x00\x00\x00\xd0\x00"; const char kvm_asm64_enable_long[] = "\x0f\x20\xc0\x0d\x00\x00\x00\x80\x0f\x22\xc0\xea\xde\xc0\xad\x0b\x50\x00" "\x48\xc7\xc0\xd8\x00\x00\x00\x0f\x00\xd8"; const char kvm_asm64_init_vm[] = "\x0f\x20\xc0\x0d\x00\x00\x00\x80\x0f\x22\xc0\xea\xde\xc0\xad\x0b\x50\x00" "\x48\xc7\xc0\xd8\x00\x00\x00\x0f\x00\xd8\x48\xc7\xc1\x3a\x00\x00\x00\x0f" "\x32\x48\x83\xc8\x05\x0f\x30\x0f\x20\xe0\x48\x0d\x00\x20\x00\x00\x0f\x22" "\xe0\x48\xc7\xc1\x80\x04\x00\x00\x0f\x32\x48\xc7\xc2\x00\x60\x00\x00\x89" "\x02\x48\xc7\xc2\x00\x70\x00\x00\x89\x02\x48\xc7\xc0\x00\x5f\x00\x00\xf3" "\x0f\xc7\x30\x48\xc7\xc0\x08\x5f\x00\x00\x66\x0f\xc7\x30\x0f\xc7\x30\x48" "\xc7\xc1\x81\x04\x00\x00\x0f\x32\x48\x83\xc8\x00\x48\x21\xd0\x48\xc7\xc2" "\x00\x40\x00\x00\x0f\x79\xd0\x48\xc7\xc1\x82\x04\x00\x00\x0f\x32\x48\x83" "\xc8\x00\x48\x21\xd0\x48\xc7\xc2\x02\x40\x00\x00\x0f\x79\xd0\x48\xc7\xc2" "\x1e\x40\x00\x00\x48\xc7\xc0\x81\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc1\x83" "\x04\x00\x00\x0f\x32\x48\x0d\xff\x6f\x03\x00\x48\x21\xd0\x48\xc7\xc2\x0c" "\x40\x00\x00\x0f\x79\xd0\x48\xc7\xc1\x84\x04\x00\x00\x0f\x32\x48\x0d\xff" "\x17\x00\x00\x48\x21\xd0\x48\xc7\xc2\x12\x40\x00\x00\x0f\x79\xd0\x48\xc7" "\xc2\x04\x2c\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2" "\x00\x28\x00\x00\x48\xc7\xc0\xff\xff\xff\xff\x0f\x79\xd0\x48\xc7\xc2\x02" "\x0c\x00\x00\x48\xc7\xc0\x50\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc0\x58\x00" "\x00\x00\x48\xc7\xc2\x00\x0c\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x04\x0c\x00" "\x00\x0f\x79\xd0\x48\xc7\xc2\x06\x0c\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x08" "\x0c\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x0a\x0c\x00\x00\x0f\x79\xd0\x48\xc7" "\xc0\xd8\x00\x00\x00\x48\xc7\xc2\x0c\x0c\x00\x00\x0f\x79\xd0\x48\xc7\xc2" "\x02\x2c\x00\x00\x48\xc7\xc0\x00\x05\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x00" "\x4c\x00\x00\x48\xc7\xc0\x50\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x10\x6c" "\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x12\x6c\x00" "\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x0f\x20\xc0\x48\xc7\xc2\x00" "\x6c\x00\x00\x48\x89\xc0\x0f\x79\xd0\x0f\x20\xd8\x48\xc7\xc2\x02\x6c\x00" "\x00\x48\x89\xc0\x0f\x79\xd0\x0f\x20\xe0\x48\xc7\xc2\x04\x6c\x00\x00\x48" "\x89\xc0\x0f\x79\xd0\x48\xc7\xc2\x06\x6c\x00\x00\x48\xc7\xc0\x00\x00\x00" "\x00\x0f\x79\xd0\x48\xc7\xc2\x08\x6c\x00\x00\x48\xc7\xc0\x00\x00\x00\x00" "\x0f\x79\xd0\x48\xc7\xc2\x0a\x6c\x00\x00\x48\xc7\xc0\x00\x3a\x00\x00\x0f" "\x79\xd0\x48\xc7\xc2\x0c\x6c\x00\x00\x48\xc7\xc0\x00\x10\x00\x00\x0f\x79" "\xd0\x48\xc7\xc2\x0e\x6c\x00\x00\x48\xc7\xc0\x00\x38\x00\x00\x0f\x79\xd0" "\x48\xc7\xc2\x14\x6c\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48" "\xc7\xc2\x16\x6c\x00\x00\x48\x8b\x04\x25\x10\x5f\x00\x00\x0f\x79\xd0\x48" "\xc7\xc2\x00\x00\x00\x00\x48\xc7\xc0\x01\x00\x00\x00\x0f\x79\xd0\x48\xc7" "\xc2\x02\x00\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2" "\x00\x20\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x02" "\x20\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x04\x20" "\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x06\x20\x00" "\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc1\x77\x02\x00\x00" "\x0f\x32\x48\xc1\xe2\x20\x48\x09\xd0\x48\xc7\xc2\x00\x2c\x00\x00\x48\x89" "\xc0\x0f\x79\xd0\x48\xc7\xc2\x04\x40\x00\x00\x48\xc7\xc0\x00\x00\x00\x00" "\x0f\x79\xd0\x48\xc7\xc2\x0a\x40\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f" "\x79\xd0\x48\xc7\xc2\x0e\x40\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79" "\xd0\x48\xc7\xc2\x10\x40\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0" "\x48\xc7\xc2\x16\x40\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48" "\xc7\xc2\x14\x40\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7" "\xc2\x00\x60\x00\x00\x48\xc7\xc0\xff\xff\xff\xff\x0f\x79\xd0\x48\xc7\xc2" "\x02\x60\x00\x00\x48\xc7\xc0\xff\xff\xff\xff\x0f\x79\xd0\x48\xc7\xc2\x1c" "\x20\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x1e\x20" "\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x20\x20\x00" "\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x22\x20\x00\x00" "\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x00\x08\x00\x00\x48" "\xc7\xc0\x58\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x02\x08\x00\x00\x48\xc7" "\xc0\x50\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x04\x08\x00\x00\x48\xc7\xc0" "\x58\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x06\x08\x00\x00\x48\xc7\xc0\x58" "\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x08\x08\x00\x00\x48\xc7\xc0\x58\x00" "\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x0a\x08\x00\x00\x48\xc7\xc0\x58\x00\x00" "\x00\x0f\x79\xd0\x48\xc7\xc2\x0c\x08\x00\x00\x48\xc7\xc0\x00\x00\x00\x00" "\x0f\x79\xd0\x48\xc7\xc2\x0e\x08\x00\x00\x48\xc7\xc0\xd8\x00\x00\x00\x0f" "\x79\xd0\x48\xc7\xc2\x12\x68\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79" "\xd0\x48\xc7\xc2\x14\x68\x00\x00\x48\xc7\xc0\x00\x3a\x00\x00\x0f\x79\xd0" "\x48\xc7\xc2\x16\x68\x00\x00\x48\xc7\xc0\x00\x10\x00\x00\x0f\x79\xd0\x48" "\xc7\xc2\x18\x68\x00\x00\x48\xc7\xc0\x00\x38\x00\x00\x0f\x79\xd0\x48\xc7" "\xc2\x00\x48\x00\x00\x48\xc7\xc0\xff\xff\x0f\x00\x0f\x79\xd0\x48\xc7\xc2" "\x02\x48\x00\x00\x48\xc7\xc0\xff\xff\x0f\x00\x0f\x79\xd0\x48\xc7\xc2\x04" "\x48\x00\x00\x48\xc7\xc0\xff\xff\x0f\x00\x0f\x79\xd0\x48\xc7\xc2\x06\x48" "\x00\x00\x48\xc7\xc0\xff\xff\x0f\x00\x0f\x79\xd0\x48\xc7\xc2\x08\x48\x00" "\x00\x48\xc7\xc0\xff\xff\x0f\x00\x0f\x79\xd0\x48\xc7\xc2\x0a\x48\x00\x00" "\x48\xc7\xc0\xff\xff\x0f\x00\x0f\x79\xd0\x48\xc7\xc2\x0c\x48\x00\x00\x48" "\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x0e\x48\x00\x00\x48\xc7" "\xc0\xff\x1f\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x10\x48\x00\x00\x48\xc7\xc0" "\xff\x1f\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x12\x48\x00\x00\x48\xc7\xc0\xff" "\x1f\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x14\x48\x00\x00\x48\xc7\xc0\x93\x40" "\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x16\x48\x00\x00\x48\xc7\xc0\x9b\x20\x00" "\x00\x0f\x79\xd0\x48\xc7\xc2\x18\x48\x00\x00\x48\xc7\xc0\x93\x40\x00\x00" "\x0f\x79\xd0\x48\xc7\xc2\x1a\x48\x00\x00\x48\xc7\xc0\x93\x40\x00\x00\x0f" "\x79\xd0\x48\xc7\xc2\x1c\x48\x00\x00\x48\xc7\xc0\x93\x40\x00\x00\x0f\x79" "\xd0\x48\xc7\xc2\x1e\x48\x00\x00\x48\xc7\xc0\x93\x40\x00\x00\x0f\x79\xd0" "\x48\xc7\xc2\x20\x48\x00\x00\x48\xc7\xc0\x82\x00\x00\x00\x0f\x79\xd0\x48" "\xc7\xc2\x22\x48\x00\x00\x48\xc7\xc0\x8b\x00\x00\x00\x0f\x79\xd0\x48\xc7" "\xc2\x1c\x68\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2" "\x1e\x68\x00\x00\x48\xc7\xc0\x00\x91\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x20" "\x68\x00\x00\x48\xc7\xc0\x02\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x06\x28" "\x00\x00\x48\xc7\xc0\x00\x05\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x0a\x28\x00" "\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x0c\x28\x00\x00" "\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x0e\x28\x00\x00\x48" "\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x10\x28\x00\x00\x48\xc7" "\xc0\x00\x00\x00\x00\x0f\x79\xd0\x0f\x20\xc0\x48\xc7\xc2\x00\x68\x00\x00" "\x48\x89\xc0\x0f\x79\xd0\x0f\x20\xd8\x48\xc7\xc2\x02\x68\x00\x00\x48\x89" "\xc0\x0f\x79\xd0\x0f\x20\xe0\x48\xc7\xc2\x04\x68\x00\x00\x48\x89\xc0\x0f" "\x79\xd0\x48\xc7\xc0\x18\x5f\x00\x00\x48\x8b\x10\x48\xc7\xc0\x20\x5f\x00" "\x00\x48\x8b\x08\x48\x31\xc0\x0f\x78\xd0\x48\x31\xc8\x0f\x79\xd0\x0f\x01" "\xc2\x48\xc7\xc2\x00\x44\x00\x00\x0f\x78\xd0\xf4"; const char kvm_asm64_vm_exit[] = "\x48\xc7\xc3\x00\x44\x00\x00\x0f\x78\xda\x48\xc7\xc3\x02\x44\x00\x00\x0f" "\x78\xd9\x48\xc7\xc0\x00\x64\x00\x00\x0f\x78\xc0\x48\xc7\xc3\x1e\x68\x00" "\x00\x0f\x78\xdb\xf4"; const char kvm_asm64_cpl3[] = "\x0f\x20\xc0\x0d\x00\x00\x00\x80\x0f\x22\xc0\xea\xde\xc0\xad\x0b\x50\x00" "\x48\xc7\xc0\xd8\x00\x00\x00\x0f\x00\xd8\x48\xc7\xc0\x6b\x00\x00\x00\x8e" "\xd8\x8e\xc0\x8e\xe0\x8e\xe8\x48\xc7\xc4\x80\x0f\x00\x00\x48\xc7\x04\x24" "\x1d\xba\x00\x00\x48\xc7\x44\x24\x04\x63\x00\x00\x00\x48\xc7\x44\x24\x08" "\x80\x0f\x00\x00\x48\xc7\x44\x24\x0c\x6b\x00\x00\x00\xcb"; #define KVM_SMI _IO(KVMIO, 0xb7) struct tss16 { uint16_t prev; uint16_t sp0; uint16_t ss0; uint16_t sp1; uint16_t ss1; uint16_t sp2; uint16_t ss2; uint16_t ip; uint16_t flags; uint16_t ax; uint16_t cx; uint16_t dx; uint16_t bx; uint16_t sp; uint16_t bp; uint16_t si; uint16_t di; uint16_t es; uint16_t cs; uint16_t ss; uint16_t ds; uint16_t ldt; } __attribute__((packed)); struct tss32 { uint16_t prev, prevh; uint32_t sp0; uint16_t ss0, ss0h; uint32_t sp1; uint16_t ss1, ss1h; uint32_t sp2; uint16_t ss2, ss2h; uint32_t cr3; uint32_t ip; uint32_t flags; uint32_t ax; uint32_t cx; uint32_t dx; uint32_t bx; uint32_t sp; uint32_t bp; uint32_t si; uint32_t di; uint16_t es, esh; uint16_t cs, csh; uint16_t ss, ssh; uint16_t ds, dsh; uint16_t fs, fsh; uint16_t gs, gsh; uint16_t ldt, ldth; uint16_t trace; uint16_t io_bitmap; } __attribute__((packed)); struct tss64 { uint32_t reserved0; uint64_t rsp[3]; uint64_t reserved1; uint64_t ist[7]; uint64_t reserved2; uint16_t reserved3; uint16_t io_bitmap; } __attribute__((packed)); static void fill_segment_descriptor(uint64_t* dt, uint64_t* lt, struct kvm_segment* seg) { uint16_t index = seg->selector >> 3; uint64_t limit = seg->g ? seg->limit >> 12 : seg->limit; uint64_t sd = (limit & 0xffff) | (seg->base & 0xffffff) << 16 | (uint64_t)seg->type << 40 | (uint64_t)seg->s << 44 | (uint64_t)seg->dpl << 45 | (uint64_t)seg->present << 47 | (limit & 0xf0000ULL) << 48 | (uint64_t)seg->avl << 52 | (uint64_t)seg->l << 53 | (uint64_t)seg->db << 54 | (uint64_t)seg->g << 55 | (seg->base & 0xff000000ULL) << 56; dt[index] = sd; lt[index] = sd; } static void fill_segment_descriptor_dword(uint64_t* dt, uint64_t* lt, struct kvm_segment* seg) { fill_segment_descriptor(dt, lt, seg); uint16_t index = seg->selector >> 3; dt[index + 1] = 0; lt[index + 1] = 0; } static void setup_syscall_msrs(int cpufd, uint16_t sel_cs, uint16_t sel_cs_cpl3) { char buf[sizeof(struct kvm_msrs) + 5 * sizeof(struct kvm_msr_entry)]; memset(buf, 0, sizeof(buf)); struct kvm_msrs* msrs = (struct kvm_msrs*)buf; struct kvm_msr_entry* entries = msrs->entries; msrs->nmsrs = 5; entries[0].index = X86_MSR_IA32_SYSENTER_CS; entries[0].data = sel_cs; entries[1].index = X86_MSR_IA32_SYSENTER_ESP; entries[1].data = X86_ADDR_STACK0; entries[2].index = X86_MSR_IA32_SYSENTER_EIP; entries[2].data = X86_ADDR_VAR_SYSEXIT; entries[3].index = X86_MSR_IA32_STAR; entries[3].data = ((uint64_t)sel_cs << 32) | ((uint64_t)sel_cs_cpl3 << 48); entries[4].index = X86_MSR_IA32_LSTAR; entries[4].data = X86_ADDR_VAR_SYSRET; ioctl(cpufd, KVM_SET_MSRS, msrs); } static void setup_32bit_idt(struct kvm_sregs* sregs, char* host_mem, uintptr_t guest_mem) { sregs->idt.base = guest_mem + X86_ADDR_VAR_IDT; sregs->idt.limit = 0x1ff; uint64_t* idt = (uint64_t*)(host_mem + sregs->idt.base); for (int i = 0; i < 32; i++) { struct kvm_segment gate; gate.selector = i << 3; switch (i % 6) { case 0: gate.type = 6; gate.base = X86_SEL_CS16; break; case 1: gate.type = 7; gate.base = X86_SEL_CS16; break; case 2: gate.type = 3; gate.base = X86_SEL_TGATE16; break; case 3: gate.type = 14; gate.base = X86_SEL_CS32; break; case 4: gate.type = 15; gate.base = X86_SEL_CS32; break; case 5: gate.type = 11; gate.base = X86_SEL_TGATE32; break; } gate.limit = guest_mem + X86_ADDR_VAR_USER_CODE2; gate.present = 1; gate.dpl = 0; gate.s = 0; gate.g = 0; gate.db = 0; gate.l = 0; gate.avl = 0; fill_segment_descriptor(idt, idt, &gate); } } static void setup_64bit_idt(struct kvm_sregs* sregs, char* host_mem, uintptr_t guest_mem) { sregs->idt.base = guest_mem + X86_ADDR_VAR_IDT; sregs->idt.limit = 0x1ff; uint64_t* idt = (uint64_t*)(host_mem + sregs->idt.base); for (int i = 0; i < 32; i++) { struct kvm_segment gate; gate.selector = (i * 2) << 3; gate.type = (i & 1) ? 14 : 15; gate.base = X86_SEL_CS64; gate.limit = guest_mem + X86_ADDR_VAR_USER_CODE2; gate.present = 1; gate.dpl = 0; gate.s = 0; gate.g = 0; gate.db = 0; gate.l = 0; gate.avl = 0; fill_segment_descriptor_dword(idt, idt, &gate); } } struct kvm_syz_vm { int vmfd; int next_cpu_id; void* host_mem; size_t total_pages; void* user_text; void* gpa0_mem; }; struct kvm_text { uintptr_t typ; const void* text; uintptr_t size; }; struct kvm_opt { uint64_t typ; uint64_t val; }; #define KVM_SETUP_PAGING (1 << 0) #define KVM_SETUP_PAE (1 << 1) #define KVM_SETUP_PROTECTED (1 << 2) #define KVM_SETUP_CPL3 (1 << 3) #define KVM_SETUP_VIRT86 (1 << 4) #define KVM_SETUP_SMM (1 << 5) #define KVM_SETUP_VM (1 << 6) static volatile long syz_kvm_setup_cpu(volatile long a0, volatile long a1, volatile long a2, volatile long a3, volatile long a4, volatile long a5, volatile long a6, volatile long a7) { const int vmfd = a0; const int cpufd = a1; char* const host_mem = (char*)a2; const struct kvm_text* const text_array_ptr = (struct kvm_text*)a3; const uintptr_t text_count = a4; const uintptr_t flags = a5; const struct kvm_opt* const opt_array_ptr = (struct kvm_opt*)a6; uintptr_t opt_count = a7; const uintptr_t page_size = 4 << 10; const uintptr_t ioapic_page = 10; const uintptr_t guest_mem_size = 24 * page_size; const uintptr_t guest_mem = 0; (void)text_count; int text_type = text_array_ptr[0].typ; const void* text = text_array_ptr[0].text; uintptr_t text_size = text_array_ptr[0].size; for (uintptr_t i = 0; i < guest_mem_size / page_size; i++) { struct kvm_userspace_memory_region memreg; memreg.slot = i; memreg.flags = 0; memreg.guest_phys_addr = guest_mem + i * page_size; if (i == ioapic_page) memreg.guest_phys_addr = 0xfec00000; memreg.memory_size = page_size; memreg.userspace_addr = (uintptr_t)host_mem + i * page_size; ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &memreg); } struct kvm_userspace_memory_region memreg; memreg.slot = 1 + (1 << 16); memreg.flags = 0; memreg.guest_phys_addr = 0x30000; memreg.memory_size = 64 << 10; memreg.userspace_addr = (uintptr_t)host_mem; ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &memreg); struct kvm_sregs sregs; if (ioctl(cpufd, KVM_GET_SREGS, &sregs)) return -1; struct kvm_regs regs; memset(®s, 0, sizeof(regs)); regs.rip = guest_mem + X86_ADDR_TEXT; regs.rsp = X86_ADDR_STACK0; sregs.gdt.base = guest_mem + X86_ADDR_GDT; sregs.gdt.limit = 256 * sizeof(uint64_t) - 1; uint64_t* gdt = (uint64_t*)(host_mem + sregs.gdt.base); struct kvm_segment seg_ldt; memset(&seg_ldt, 0, sizeof(seg_ldt)); seg_ldt.selector = X86_SEL_LDT; seg_ldt.type = 2; seg_ldt.base = guest_mem + X86_ADDR_LDT; seg_ldt.limit = 256 * sizeof(uint64_t) - 1; seg_ldt.present = 1; seg_ldt.dpl = 0; seg_ldt.s = 0; seg_ldt.g = 0; seg_ldt.db = 1; seg_ldt.l = 0; sregs.ldt = seg_ldt; uint64_t* ldt = (uint64_t*)(host_mem + sregs.ldt.base); struct kvm_segment seg_cs16; memset(&seg_cs16, 0, sizeof(seg_cs16)); seg_cs16.selector = X86_SEL_CS16; seg_cs16.type = 11; seg_cs16.base = 0; seg_cs16.limit = 0xfffff; seg_cs16.present = 1; seg_cs16.dpl = 0; seg_cs16.s = 1; seg_cs16.g = 0; seg_cs16.db = 0; seg_cs16.l = 0; struct kvm_segment seg_ds16 = seg_cs16; seg_ds16.selector = X86_SEL_DS16; seg_ds16.type = 3; struct kvm_segment seg_cs16_cpl3 = seg_cs16; seg_cs16_cpl3.selector = X86_SEL_CS16_CPL3; seg_cs16_cpl3.dpl = 3; struct kvm_segment seg_ds16_cpl3 = seg_ds16; seg_ds16_cpl3.selector = X86_SEL_DS16_CPL3; seg_ds16_cpl3.dpl = 3; struct kvm_segment seg_cs32 = seg_cs16; seg_cs32.selector = X86_SEL_CS32; seg_cs32.db = 1; struct kvm_segment seg_ds32 = seg_ds16; seg_ds32.selector = X86_SEL_DS32; seg_ds32.db = 1; struct kvm_segment seg_cs32_cpl3 = seg_cs32; seg_cs32_cpl3.selector = X86_SEL_CS32_CPL3; seg_cs32_cpl3.dpl = 3; struct kvm_segment seg_ds32_cpl3 = seg_ds32; seg_ds32_cpl3.selector = X86_SEL_DS32_CPL3; seg_ds32_cpl3.dpl = 3; struct kvm_segment seg_cs64 = seg_cs16; seg_cs64.selector = X86_SEL_CS64; seg_cs64.l = 1; struct kvm_segment seg_ds64 = seg_ds32; seg_ds64.selector = X86_SEL_DS64; struct kvm_segment seg_cs64_cpl3 = seg_cs64; seg_cs64_cpl3.selector = X86_SEL_CS64_CPL3; seg_cs64_cpl3.dpl = 3; struct kvm_segment seg_ds64_cpl3 = seg_ds64; seg_ds64_cpl3.selector = X86_SEL_DS64_CPL3; seg_ds64_cpl3.dpl = 3; struct kvm_segment seg_tss32; memset(&seg_tss32, 0, sizeof(seg_tss32)); seg_tss32.selector = X86_SEL_TSS32; seg_tss32.type = 9; seg_tss32.base = X86_ADDR_VAR_TSS32; seg_tss32.limit = 0x1ff; seg_tss32.present = 1; seg_tss32.dpl = 0; seg_tss32.s = 0; seg_tss32.g = 0; seg_tss32.db = 0; seg_tss32.l = 0; struct kvm_segment seg_tss32_2 = seg_tss32; seg_tss32_2.selector = X86_SEL_TSS32_2; seg_tss32_2.base = X86_ADDR_VAR_TSS32_2; struct kvm_segment seg_tss32_cpl3 = seg_tss32; seg_tss32_cpl3.selector = X86_SEL_TSS32_CPL3; seg_tss32_cpl3.base = X86_ADDR_VAR_TSS32_CPL3; struct kvm_segment seg_tss32_vm86 = seg_tss32; seg_tss32_vm86.selector = X86_SEL_TSS32_VM86; seg_tss32_vm86.base = X86_ADDR_VAR_TSS32_VM86; struct kvm_segment seg_tss16 = seg_tss32; seg_tss16.selector = X86_SEL_TSS16; seg_tss16.base = X86_ADDR_VAR_TSS16; seg_tss16.limit = 0xff; seg_tss16.type = 1; struct kvm_segment seg_tss16_2 = seg_tss16; seg_tss16_2.selector = X86_SEL_TSS16_2; seg_tss16_2.base = X86_ADDR_VAR_TSS16_2; seg_tss16_2.dpl = 0; struct kvm_segment seg_tss16_cpl3 = seg_tss16; seg_tss16_cpl3.selector = X86_SEL_TSS16_CPL3; seg_tss16_cpl3.base = X86_ADDR_VAR_TSS16_CPL3; seg_tss16_cpl3.dpl = 3; struct kvm_segment seg_tss64 = seg_tss32; seg_tss64.selector = X86_SEL_TSS64; seg_tss64.base = X86_ADDR_VAR_TSS64; seg_tss64.limit = 0x1ff; struct kvm_segment seg_tss64_cpl3 = seg_tss64; seg_tss64_cpl3.selector = X86_SEL_TSS64_CPL3; seg_tss64_cpl3.base = X86_ADDR_VAR_TSS64_CPL3; seg_tss64_cpl3.dpl = 3; struct kvm_segment seg_cgate16; memset(&seg_cgate16, 0, sizeof(seg_cgate16)); seg_cgate16.selector = X86_SEL_CGATE16; seg_cgate16.type = 4; seg_cgate16.base = X86_SEL_CS16 | (2 << 16); seg_cgate16.limit = X86_ADDR_VAR_USER_CODE2; seg_cgate16.present = 1; seg_cgate16.dpl = 0; seg_cgate16.s = 0; seg_cgate16.g = 0; seg_cgate16.db = 0; seg_cgate16.l = 0; seg_cgate16.avl = 0; struct kvm_segment seg_tgate16 = seg_cgate16; seg_tgate16.selector = X86_SEL_TGATE16; seg_tgate16.type = 3; seg_cgate16.base = X86_SEL_TSS16_2; seg_tgate16.limit = 0; struct kvm_segment seg_cgate32 = seg_cgate16; seg_cgate32.selector = X86_SEL_CGATE32; seg_cgate32.type = 12; seg_cgate32.base = X86_SEL_CS32 | (2 << 16); struct kvm_segment seg_tgate32 = seg_cgate32; seg_tgate32.selector = X86_SEL_TGATE32; seg_tgate32.type = 11; seg_tgate32.base = X86_SEL_TSS32_2; seg_tgate32.limit = 0; struct kvm_segment seg_cgate64 = seg_cgate16; seg_cgate64.selector = X86_SEL_CGATE64; seg_cgate64.type = 12; seg_cgate64.base = X86_SEL_CS64; int kvmfd = open("/dev/kvm", O_RDWR); char buf[sizeof(struct kvm_cpuid2) + 128 * sizeof(struct kvm_cpuid_entry2)]; memset(buf, 0, sizeof(buf)); struct kvm_cpuid2* cpuid = (struct kvm_cpuid2*)buf; cpuid->nent = 128; ioctl(kvmfd, KVM_GET_SUPPORTED_CPUID, cpuid); ioctl(cpufd, KVM_SET_CPUID2, cpuid); close(kvmfd); const char* text_prefix = 0; int text_prefix_size = 0; char* host_text = host_mem + X86_ADDR_TEXT; if (text_type == 8) { if (flags & KVM_SETUP_SMM) { if (flags & KVM_SETUP_PROTECTED) { sregs.cs = seg_cs16; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds16; sregs.cr0 |= X86_CR0_PE; } else { sregs.cs.selector = 0; sregs.cs.base = 0; } *(host_mem + X86_ADDR_TEXT) = 0xf4; host_text = host_mem + 0x8000; ioctl(cpufd, KVM_SMI, 0); } else if (flags & KVM_SETUP_VIRT86) { sregs.cs = seg_cs32; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32; sregs.cr0 |= X86_CR0_PE; sregs.efer |= X86_EFER_SCE; setup_syscall_msrs(cpufd, X86_SEL_CS32, X86_SEL_CS32_CPL3); setup_32bit_idt(&sregs, host_mem, guest_mem); if (flags & KVM_SETUP_PAGING) { uint64_t pd_addr = guest_mem + X86_ADDR_PD; uint64_t* pd = (uint64_t*)(host_mem + X86_ADDR_PD); pd[0] = X86_PDE32_PRESENT | X86_PDE32_RW | X86_PDE32_USER | X86_PDE32_PS; sregs.cr3 = pd_addr; sregs.cr4 |= X86_CR4_PSE; text_prefix = kvm_asm32_paged_vm86; text_prefix_size = sizeof(kvm_asm32_paged_vm86) - 1; } else { text_prefix = kvm_asm32_vm86; text_prefix_size = sizeof(kvm_asm32_vm86) - 1; } } else { sregs.cs.selector = 0; sregs.cs.base = 0; } } else if (text_type == 16) { if (flags & KVM_SETUP_CPL3) { sregs.cs = seg_cs16; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds16; text_prefix = kvm_asm16_cpl3; text_prefix_size = sizeof(kvm_asm16_cpl3) - 1; } else { sregs.cr0 |= X86_CR0_PE; sregs.cs = seg_cs16; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds16; } } else if (text_type == 32) { sregs.cr0 |= X86_CR0_PE; sregs.efer |= X86_EFER_SCE; setup_syscall_msrs(cpufd, X86_SEL_CS32, X86_SEL_CS32_CPL3); setup_32bit_idt(&sregs, host_mem, guest_mem); if (flags & KVM_SETUP_SMM) { sregs.cs = seg_cs32; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32; *(host_mem + X86_ADDR_TEXT) = 0xf4; host_text = host_mem + 0x8000; ioctl(cpufd, KVM_SMI, 0); } else if (flags & KVM_SETUP_PAGING) { sregs.cs = seg_cs32; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32; uint64_t pd_addr = guest_mem + X86_ADDR_PD; uint64_t* pd = (uint64_t*)(host_mem + X86_ADDR_PD); pd[0] = X86_PDE32_PRESENT | X86_PDE32_RW | X86_PDE32_USER | X86_PDE32_PS; sregs.cr3 = pd_addr; sregs.cr4 |= X86_CR4_PSE; text_prefix = kvm_asm32_paged; text_prefix_size = sizeof(kvm_asm32_paged) - 1; } else if (flags & KVM_SETUP_CPL3) { sregs.cs = seg_cs32_cpl3; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32_cpl3; } else { sregs.cs = seg_cs32; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32; } } else { sregs.efer |= X86_EFER_LME | X86_EFER_SCE; sregs.cr0 |= X86_CR0_PE; setup_syscall_msrs(cpufd, X86_SEL_CS64, X86_SEL_CS64_CPL3); setup_64bit_idt(&sregs, host_mem, guest_mem); sregs.cs = seg_cs32; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32; uint64_t pml4_addr = guest_mem + X86_ADDR_PML4; uint64_t* pml4 = (uint64_t*)(host_mem + X86_ADDR_PML4); uint64_t pdpt_addr = guest_mem + X86_ADDR_PDP; uint64_t* pdpt = (uint64_t*)(host_mem + X86_ADDR_PDP); uint64_t pd_addr = guest_mem + X86_ADDR_PD; uint64_t* pd = (uint64_t*)(host_mem + X86_ADDR_PD); pml4[0] = X86_PDE64_PRESENT | X86_PDE64_RW | X86_PDE64_USER | pdpt_addr; pdpt[0] = X86_PDE64_PRESENT | X86_PDE64_RW | X86_PDE64_USER | pd_addr; pd[0] = X86_PDE64_PRESENT | X86_PDE64_RW | X86_PDE64_USER | X86_PDE64_PS; sregs.cr3 = pml4_addr; sregs.cr4 |= X86_CR4_PAE; if (flags & KVM_SETUP_VM) { sregs.cr0 |= X86_CR0_NE; *((uint64_t*)(host_mem + X86_ADDR_VAR_VMXON_PTR)) = X86_ADDR_VAR_VMXON; *((uint64_t*)(host_mem + X86_ADDR_VAR_VMCS_PTR)) = X86_ADDR_VAR_VMCS; memcpy(host_mem + X86_ADDR_VAR_VMEXIT_CODE, kvm_asm64_vm_exit, sizeof(kvm_asm64_vm_exit) - 1); *((uint64_t*)(host_mem + X86_ADDR_VAR_VMEXIT_PTR)) = X86_ADDR_VAR_VMEXIT_CODE; text_prefix = kvm_asm64_init_vm; text_prefix_size = sizeof(kvm_asm64_init_vm) - 1; } else if (flags & KVM_SETUP_CPL3) { text_prefix = kvm_asm64_cpl3; text_prefix_size = sizeof(kvm_asm64_cpl3) - 1; } else { text_prefix = kvm_asm64_enable_long; text_prefix_size = sizeof(kvm_asm64_enable_long) - 1; } } struct tss16 tss16; memset(&tss16, 0, sizeof(tss16)); tss16.ss0 = tss16.ss1 = tss16.ss2 = X86_SEL_DS16; tss16.sp0 = tss16.sp1 = tss16.sp2 = X86_ADDR_STACK0; tss16.ip = X86_ADDR_VAR_USER_CODE2; tss16.flags = (1 << 1); tss16.cs = X86_SEL_CS16; tss16.es = tss16.ds = tss16.ss = X86_SEL_DS16; tss16.ldt = X86_SEL_LDT; struct tss16* tss16_addr = (struct tss16*)(host_mem + seg_tss16_2.base); memcpy(tss16_addr, &tss16, sizeof(tss16)); memset(&tss16, 0, sizeof(tss16)); tss16.ss0 = tss16.ss1 = tss16.ss2 = X86_SEL_DS16; tss16.sp0 = tss16.sp1 = tss16.sp2 = X86_ADDR_STACK0; tss16.ip = X86_ADDR_VAR_USER_CODE2; tss16.flags = (1 << 1); tss16.cs = X86_SEL_CS16_CPL3; tss16.es = tss16.ds = tss16.ss = X86_SEL_DS16_CPL3; tss16.ldt = X86_SEL_LDT; struct tss16* tss16_cpl3_addr = (struct tss16*)(host_mem + seg_tss16_cpl3.base); memcpy(tss16_cpl3_addr, &tss16, sizeof(tss16)); struct tss32 tss32; memset(&tss32, 0, sizeof(tss32)); tss32.ss0 = tss32.ss1 = tss32.ss2 = X86_SEL_DS32; tss32.sp0 = tss32.sp1 = tss32.sp2 = X86_ADDR_STACK0; tss32.ip = X86_ADDR_VAR_USER_CODE; tss32.flags = (1 << 1) | (1 << 17); tss32.ldt = X86_SEL_LDT; tss32.cr3 = sregs.cr3; tss32.io_bitmap = offsetof(struct tss32, io_bitmap); struct tss32* tss32_addr = (struct tss32*)(host_mem + seg_tss32_vm86.base); memcpy(tss32_addr, &tss32, sizeof(tss32)); memset(&tss32, 0, sizeof(tss32)); tss32.ss0 = tss32.ss1 = tss32.ss2 = X86_SEL_DS32; tss32.sp0 = tss32.sp1 = tss32.sp2 = X86_ADDR_STACK0; tss32.ip = X86_ADDR_VAR_USER_CODE; tss32.flags = (1 << 1); tss32.cr3 = sregs.cr3; tss32.es = tss32.ds = tss32.ss = tss32.gs = tss32.fs = X86_SEL_DS32; tss32.cs = X86_SEL_CS32; tss32.ldt = X86_SEL_LDT; tss32.cr3 = sregs.cr3; tss32.io_bitmap = offsetof(struct tss32, io_bitmap); struct tss32* tss32_cpl3_addr = (struct tss32*)(host_mem + seg_tss32_2.base); memcpy(tss32_cpl3_addr, &tss32, sizeof(tss32)); struct tss64 tss64; memset(&tss64, 0, sizeof(tss64)); tss64.rsp[0] = X86_ADDR_STACK0; tss64.rsp[1] = X86_ADDR_STACK0; tss64.rsp[2] = X86_ADDR_STACK0; tss64.io_bitmap = offsetof(struct tss64, io_bitmap); struct tss64* tss64_addr = (struct tss64*)(host_mem + seg_tss64.base); memcpy(tss64_addr, &tss64, sizeof(tss64)); memset(&tss64, 0, sizeof(tss64)); tss64.rsp[0] = X86_ADDR_STACK0; tss64.rsp[1] = X86_ADDR_STACK0; tss64.rsp[2] = X86_ADDR_STACK0; tss64.io_bitmap = offsetof(struct tss64, io_bitmap); struct tss64* tss64_cpl3_addr = (struct tss64*)(host_mem + seg_tss64_cpl3.base); memcpy(tss64_cpl3_addr, &tss64, sizeof(tss64)); if (text_size > 1000) text_size = 1000; if (text_prefix) { memcpy(host_text, text_prefix, text_prefix_size); void* patch = memmem(host_text, text_prefix_size, "\xde\xc0\xad\x0b", 4); if (patch) *((uint32_t*)patch) = guest_mem + X86_ADDR_TEXT + ((char*)patch - host_text) + 6; uint16_t magic = X86_PREFIX_SIZE; patch = memmem(host_text, text_prefix_size, &magic, sizeof(magic)); if (patch) *((uint16_t*)patch) = guest_mem + X86_ADDR_TEXT + text_prefix_size; } memcpy((void*)(host_text + text_prefix_size), text, text_size); *(host_text + text_prefix_size + text_size) = 0xf4; memcpy(host_mem + X86_ADDR_VAR_USER_CODE, text, text_size); *(host_mem + X86_ADDR_VAR_USER_CODE + text_size) = 0xf4; *(host_mem + X86_ADDR_VAR_HLT) = 0xf4; memcpy(host_mem + X86_ADDR_VAR_SYSRET, "\x0f\x07\xf4", 3); memcpy(host_mem + X86_ADDR_VAR_SYSEXIT, "\x0f\x35\xf4", 3); *(uint64_t*)(host_mem + X86_ADDR_VAR_VMWRITE_FLD) = 0; *(uint64_t*)(host_mem + X86_ADDR_VAR_VMWRITE_VAL) = 0; if (opt_count > 2) opt_count = 2; for (uintptr_t i = 0; i < opt_count; i++) { uint64_t typ = opt_array_ptr[i].typ; uint64_t val = opt_array_ptr[i].val; switch (typ % 9) { case 0: sregs.cr0 ^= val & (X86_CR0_MP | X86_CR0_EM | X86_CR0_ET | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | X86_CR0_NW | X86_CR0_CD); break; case 1: sregs.cr4 ^= val & (X86_CR4_VME | X86_CR4_PVI | X86_CR4_TSD | X86_CR4_DE | X86_CR4_MCE | X86_CR4_PGE | X86_CR4_PCE | X86_CR4_OSFXSR | X86_CR4_OSXMMEXCPT | X86_CR4_UMIP | X86_CR4_VMXE | X86_CR4_SMXE | X86_CR4_FSGSBASE | X86_CR4_PCIDE | X86_CR4_OSXSAVE | X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE); break; case 2: sregs.efer ^= val & (X86_EFER_SCE | X86_EFER_NXE | X86_EFER_SVME | X86_EFER_LMSLE | X86_EFER_FFXSR | X86_EFER_TCE); break; case 3: val &= ((1 << 8) | (1 << 9) | (1 << 10) | (1 << 12) | (1 << 13) | (1 << 14) | (1 << 15) | (1 << 18) | (1 << 19) | (1 << 20) | (1 << 21)); regs.rflags ^= val; tss16_addr->flags ^= val; tss16_cpl3_addr->flags ^= val; tss32_addr->flags ^= val; tss32_cpl3_addr->flags ^= val; break; case 4: seg_cs16.type = val & 0xf; seg_cs32.type = val & 0xf; seg_cs64.type = val & 0xf; break; case 5: seg_cs16_cpl3.type = val & 0xf; seg_cs32_cpl3.type = val & 0xf; seg_cs64_cpl3.type = val & 0xf; break; case 6: seg_ds16.type = val & 0xf; seg_ds32.type = val & 0xf; seg_ds64.type = val & 0xf; break; case 7: seg_ds16_cpl3.type = val & 0xf; seg_ds32_cpl3.type = val & 0xf; seg_ds64_cpl3.type = val & 0xf; break; case 8: *(uint64_t*)(host_mem + X86_ADDR_VAR_VMWRITE_FLD) = (val & 0xffff); *(uint64_t*)(host_mem + X86_ADDR_VAR_VMWRITE_VAL) = (val >> 16); break; default: exit(1); } } regs.rflags |= 2; fill_segment_descriptor(gdt, ldt, &seg_ldt); fill_segment_descriptor(gdt, ldt, &seg_cs16); fill_segment_descriptor(gdt, ldt, &seg_ds16); fill_segment_descriptor(gdt, ldt, &seg_cs16_cpl3); fill_segment_descriptor(gdt, ldt, &seg_ds16_cpl3); fill_segment_descriptor(gdt, ldt, &seg_cs32); fill_segment_descriptor(gdt, ldt, &seg_ds32); fill_segment_descriptor(gdt, ldt, &seg_cs32_cpl3); fill_segment_descriptor(gdt, ldt, &seg_ds32_cpl3); fill_segment_descriptor(gdt, ldt, &seg_cs64); fill_segment_descriptor(gdt, ldt, &seg_ds64); fill_segment_descriptor(gdt, ldt, &seg_cs64_cpl3); fill_segment_descriptor(gdt, ldt, &seg_ds64_cpl3); fill_segment_descriptor(gdt, ldt, &seg_tss32); fill_segment_descriptor(gdt, ldt, &seg_tss32_2); fill_segment_descriptor(gdt, ldt, &seg_tss32_cpl3); fill_segment_descriptor(gdt, ldt, &seg_tss32_vm86); fill_segment_descriptor(gdt, ldt, &seg_tss16); fill_segment_descriptor(gdt, ldt, &seg_tss16_2); fill_segment_descriptor(gdt, ldt, &seg_tss16_cpl3); fill_segment_descriptor_dword(gdt, ldt, &seg_tss64); fill_segment_descriptor_dword(gdt, ldt, &seg_tss64_cpl3); fill_segment_descriptor(gdt, ldt, &seg_cgate16); fill_segment_descriptor(gdt, ldt, &seg_tgate16); fill_segment_descriptor(gdt, ldt, &seg_cgate32); fill_segment_descriptor(gdt, ldt, &seg_tgate32); fill_segment_descriptor_dword(gdt, ldt, &seg_cgate64); if (ioctl(cpufd, KVM_SET_SREGS, &sregs)) return -1; if (ioctl(cpufd, KVM_SET_REGS, ®s)) return -1; return 0; } uint64_t r[4] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); const char* reason; (void)reason; intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } // openat$kvm arguments: [ // fd: const = 0xffffffffffffff9c (8 bytes) // file: ptr[in, buffer] { // buffer: {2f 64 65 76 2f 6b 76 6d 00} (length 0x9) // } // flags: open_flags = 0x0 (4 bytes) // mode: const = 0x0 (2 bytes) // ] // returns fd_kvm memcpy((void*)0x200000000240, "/dev/kvm\000", 9); res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x200000000240ul, /*flags=*/0, /*mode=*/0); if (res != -1) r[0] = res; // ioctl$KVM_CREATE_VM arguments: [ // fd: fd_kvm (resource) // cmd: const = 0xae01 (4 bytes) // type: intptr = 0x0 (8 bytes) // ] // returns fd_kvmvm res = syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0xae01, /*type=*/0ul); if (res != -1) r[1] = res; // ioctl$KVM_CREATE_VCPU arguments: [ // fd: fd_kvmvm (resource) // cmd: const = 0xae41 (4 bytes) // id: intptr = 0x2 (8 bytes) // ] // returns fd_kvmcpu res = syscall(__NR_ioctl, /*fd=*/r[1], /*cmd=*/0xae41, /*id=*/2ul); if (res != -1) r[2] = res; // syz_kvm_setup_cpu$x86 arguments: [ // fd: fd_kvmvm (resource) // cpufd: fd_kvmcpu (resource) // usermem: VMA[0x18000] // text: ptr[in, array[kvm_text_x86]] { // array[kvm_text_x86] { // union kvm_text_x86 { // text64: kvm_text_x86_64 { // typ: const = 0x40 (8 bytes) // text: nil // size: len = 0x0 (8 bytes) // } // } // } // } // ntext: len = 0x1 (8 bytes) // flags: kvm_setup_flags = 0xe8 (8 bytes) // opts: nil // nopt: len = 0x0 (8 bytes) // ] *(uint64_t*)0x200000000140 = 0x40; *(uint64_t*)0x200000000148 = 0; *(uint64_t*)0x200000000150 = 0; syz_kvm_setup_cpu( /*fd=*/-1, /*cpufd=*/r[2], /*usermem=*/0x200000000000, /*text=*/0x200000000140, /*ntext=*/1, /*flags=KVM_SETUP_VM|KVM_SETUP_SMM|KVM_SETUP_CPL3|0x80*/ 0xe8, /*opts=*/0, /*nopt=*/0); // syz_open_dev$evdev arguments: [ // dev: ptr[in, buffer] { // buffer: {2f 64 65 76 2f 69 6e 70 75 74 2f 65 76 65 6e 74 23 00} // (length 0x12) // } // id: intptr = 0x0 (8 bytes) // flags: open_flags = 0x0 (8 bytes) // ] // returns fd_evdev memcpy((void*)0x200000000040, "/dev/input/event#\000", 18); res = -1; res = syz_open_dev(/*dev=*/0x200000000040, /*id=*/0, /*flags=*/0); if (res != -1) r[3] = res; // syz_usb_disconnect arguments: [ // fd: fd_usb (resource) // ] syz_usb_disconnect(/*fd=*/r[3]); // syz_usb_connect arguments: [ // speed: usb_device_speed = 0x4 (8 bytes) // dev_len: len = 0x24 (8 bytes) // dev: ptr[inout, array[ANYUNION]] { // array[ANYUNION] { // } // } // conn_descs: nil // ] // returns fd_usb syz_usb_connect(/*speed=USB_SPEED_WIRELESS*/ 4, /*dev_len=*/0x24, /*dev=*/0x200000000400, /*conn_descs=*/0); // ioctl$EVIOCRMFF arguments: [ // fd: fd_evdev (resource) // cmd: const = 0xc0085504 (4 bytes) // arg: ptr[in, int32] { // int32 = 0x3 (4 bytes) // } // ] *(uint32_t*)0x200000000080 = 3; syscall(__NR_ioctl, /*fd=*/r[3], /*cmd=*/0xc0085504, /*arg=*/0x200000000080ul); return 0; }