Hello, I reproduced this bug and comfired it still existed in the latest net tree. Since I found there are no stable reproducer so far, I can confrim the repro.c and repro.txt can trigger the bug steadily. If you fix this issue, please add the following tag to the commit: Reported-by: xingwei lee <xrivendell7@xxxxxxxxx> kernel version: net 7c5e046bdcb2513f9decb3765d8bf92d604279cf kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=298e57794135adf0 compiler: gcc-12 syzkaller login: root Linux syzkaller 6.7.0-rc6-00157-g7c5e046bdcb2 #9 SMP PREEMPT_DYNAMIC Sat Dec 23 16:03:42 CST 2023 x86_64 TITLE: WARNING in __input_unregister_device ------------[ cut here ]------------ add_uevent_var: buffer size too small WARNING: CPU: 0 PID: 4483 at lib/kobject_uevent.c:671 add_uevent_var+0x200/0x210 lib/kobject_uevent.c:671 Modules linked in: CPU: 0 PID: 4483 Comm: kworker/0:3 Tainted: G W 6.7.0-rc6-00157-g7c5e046bdcb2 #4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014 Workqueue: usb_hub_wq hub_event RIP: 0010:add_uevent_var+0x200/0x210 lib/kobject_uevent.c:671 Code: d6 b7 9a fb 48 c7 c7 40 60 d6 86 e8 1a 8a 7e fb 0f 0b bb f4 ff ff ff eb af e8 bc b7 9a fb 48 c8 RSP: 0018:ffff88800df5f3b0 EFLAGS: 00010282 RAX: dffffc0000000000 RBX: ffff888028394000 RCX: ffffffff811f42a6 RDX: ffff88800e72b700 RSI: ffffffff811f42b0 RDI: 0000000000000001 RBP: ffff88800df5f480 R08: 0000000000000001 R09: ffffed10175850d9 R10: 0000000000000000 R11: 000000005f646461 R12: 1ffff11001bebe79 R13: 0000000000000022 R14: ffff888028394a1c R15: 00000000000007de FS: 0000000000000000(0000) GS:ffff8880bac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561cd67ae020 CR3: 000000000c8c5000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> kobject_uevent_env+0x803/0xc20 lib/kobject_uevent.c:605 kobject_uevent+0x23/0x30 lib/kobject_uevent.c:642 device_del+0x4a1/0x670 drivers/base/core.c:3832 __input_unregister_device+0x21c/0x280 drivers/input/input.c:2232 input_unregister_device+0x99/0xd0 drivers/input/input.c:2440 hidinput_disconnect+0xc8/0x1f0 drivers/hid/hid-input.c:2388 hid_disconnect+0xdf/0x110 drivers/hid/hid-core.c:2280 hid_hw_stop+0x1b/0x50 drivers/hid/hid-core.c:2329 ms_remove+0x1b/0x70 drivers/hid/hid-microsoft.c:409 hid_device_remove+0x96/0x150 drivers/hid/hid-core.c:2689 device_remove+0x7d/0xd0 drivers/base/dd.c:567 __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x319/0x3c0 drivers/base/dd.c:1295 device_release_driver+0x1d/0x30 drivers/base/dd.c:1318 bus_remove_device+0x163/0x1c0 drivers/base/bus.c:574 device_del+0x2b7/0x670 drivers/base/core.c:3814 hid_remove_device drivers/hid/hid-core.c:2867 [inline] hid_destroy_device+0x99/0xc0 drivers/hid/hid-core.c:2887 usbhid_disconnect+0x7f/0xb0 drivers/hid/usbhid/hid-core.c:1456 usb_unbind_interface+0x12c/0x500 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:569 [inline] device_remove+0xb9/0xd0 drivers/base/dd.c:561 __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x319/0x3c0 drivers/base/dd.c:1295 device_release_driver+0x1d/0x30 drivers/base/dd.c:1318 bus_remove_device+0x163/0x1c0 drivers/base/bus.c:574 device_del+0x2b7/0x670 drivers/base/core.c:3814 usb_disable_device+0x1f5/0x350 drivers/usb/core/message.c:1416 usb_disconnect+0x1df/0x530 drivers/usb/core/hub.c:2237 hub_port_connect drivers/usb/core/hub.c:5280 [inline] hub_port_connect_change drivers/usb/core/hub.c:5580 [inline] port_event drivers/usb/core/hub.c:5740 [inline] hub_event+0x161a/0x30d0 drivers/usb/core/hub.c:5822 process_one_work+0x391/0x5f0 kernel/workqueue.c:2627 process_scheduled_works kernel/workqueue.c:2700 [inline] worker_thread+0x4c2/0x7f0 kernel/workqueue.c:2781 kthread+0x1d6/0x230 kernel/kthread.c:388 ret_from_fork+0x4e/0x70 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 </TASK> =* repro.c =* #define _GNU_SOURCE #include <dirent.h> #include <endian.h> #include <errno.h> #include <fcntl.h> #include <linux/usb/ch9.h> #include <signal.h> #include <stdarg.h> #include <stdbool.h> #include <stddef.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/mount.h> #include <sys/prctl.h> #include <sys/stat.h> #include <sys/syscall.h> #include <sys/types.h> #include <sys/wait.h> #include <time.h> #include <unistd.h> static unsigned long long procid; static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } 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 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; } struct vusb_descriptor { uint8_t req_type; uint8_t desc_type; uint32_t len; char data[0]; } __attribute__((packed)); struct vusb_descriptors { uint32_t len; struct vusb_descriptor* generic; struct vusb_descriptor* descs[0]; } __attribute__((packed)); struct vusb_response { uint8_t type; uint8_t req; uint32_t len; char data[0]; } __attribute__((packed)); struct vusb_responses { uint32_t len; struct vusb_response* generic; struct vusb_response* resps[0]; } __attribute__((packed)); static bool lookup_control_response(const struct vusb_descriptors* descs, const struct vusb_responses* resps, struct usb_ctrlrequest* ctrl, char** response_data, uint32_t* response_length) { int descs_num = 0; int resps_num = 0; if (descs) descs_num = (descs->len - offsetof(struct vusb_descriptors, descs)) / sizeof(descs->descs[0]); if (resps) resps_num = (resps->len - offsetof(struct vusb_responses, resps)) / sizeof(resps->resps[0]); uint8_t req = ctrl->bRequest; uint8_t req_type = ctrl->bRequestType & USB_TYPE_MASK; uint8_t desc_type = ctrl->wValue >> 8; if (req == USB_REQ_GET_DESCRIPTOR) { int i; for (i = 0; i < descs_num; i++) { struct vusb_descriptor* desc = descs->descs[i]; if (!desc) continue; if (desc->req_type == req_type && desc->desc_type == desc_type) { *response_length = desc->len; if (*response_length != 0) *response_data = &desc->data[0]; else *response_data = NULL; return true; } } if (descs && descs->generic) { *response_data = &descs->generic->data[0]; *response_length = descs->generic->len; return true; } } else { int i; for (i = 0; i < resps_num; i++) { struct vusb_response* resp = resps->resps[i]; if (!resp) continue; if (resp->type == req_type && resp->req == req) { *response_length = resp->len; if (*response_length != 0) *response_data = &resp->data[0]; else *response_data = NULL; return true; } } if (resps && resps->generic) { *response_data = &resps->generic->data[0]; *response_length = resps->generic->len; return true; } } return false; } #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); } static int lookup_interface(int fd, uint8_t bInterfaceNumber, uint8_t bAlternateSetting) { struct usb_device_index* index = lookup_usb_index(fd); if (!index) return -1; for (int i = 0; i < index->ifaces_num; i++) { if (index->ifaces[i].bInterfaceNumber == bInterfaceNumber && index->ifaces[i].bAlternateSetting == bAlternateSetting) return i; } return -1; } #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_control_io(volatile long a0, volatile long a1, volatile long a2) { int fd = a0; const struct vusb_descriptors* descs = (const struct vusb_descriptors*)a1; const struct vusb_responses* resps = (const struct vusb_responses*)a2; struct usb_raw_control_event event; event.inner.type = 0; event.inner.length = USB_MAX_PACKET_SIZE; int rv = usb_raw_event_fetch(fd, (struct usb_raw_event*)&event); if (rv < 0) { return rv; } if (event.inner.type != USB_RAW_EVENT_CONTROL) { return -1; } char* response_data = NULL; uint32_t response_length = 0; if ((event.ctrl.bRequestType & USB_DIR_IN) && event.ctrl.wLength) { if (!lookup_control_response(descs, resps, &event.ctrl, &response_data, &response_length)) { usb_raw_ep0_stall(fd); return -1; } } else { if ((event.ctrl.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD || event.ctrl.bRequest == USB_REQ_SET_INTERFACE) { int iface_num = event.ctrl.wIndex; int alt_set = event.ctrl.wValue; int iface_index = lookup_interface(fd, iface_num, alt_set); if (iface_index < 0) { } else { set_interface(fd, iface_index); } } response_length = event.ctrl.wLength; } 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; if ((event.ctrl.bRequestType & USB_DIR_IN) && !event.ctrl.wLength) { response_length = USB_MAX_PACKET_SIZE; } response.inner.length = response_length; if (response_data) memcpy(&response.data[0], response_data, response_length); else memset(&response.data[0], 0, response_length); if ((event.ctrl.bRequestType & USB_DIR_IN) && event.ctrl.wLength) { 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 0; } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); for (int i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } } static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { setup_test(); execute_one(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } } } uint64_t r[1] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; memcpy((void*)0x20000040, "\x12\x01\x00\x00\x00\x00\x18\x10\x5e\x04\xda\x07\x07\x00\x00\x00\x00" "\x01\x09\x02\x24\x00\x01\x00\x00\x00\x00\x09\x04\x00\x00\x09\x03\x00" "\x00\x00\x09\x21\x00\x00\x00\x01\x22\x22\x00\x09\x05\x81\x03\x08", 50); res = -1; res = syz_usb_connect(/*speed=*/0, /*dev_len=*/0x36, /*dev=*/0x20000040, /*conn_descs=*/0); if (res != -1) r[0] = res; syz_usb_control_io(/*fd=*/r[0], /*descs=*/0, /*resps=*/0); *(uint32_t*)0x200001c0 = 0x24; *(uint64_t*)0x200001c4 = 0; *(uint64_t*)0x200001cc = 0; *(uint64_t*)0x200001d4 = 0x20000080; memcpy((void*)0x20000080, "\x00\x22\x22\x00\x00\x00\x96\x23\x13\x06\xe5\x3f\x07\x0c\xad\x00\x00" "\x2a\x90\x01\x07\x09\x00\xde\x00\x83", 26); *(uint64_t*)0x200001dc = 0; syz_usb_control_io(/*fd=*/r[0], /*descs=*/0x200001c0, /*resps=*/0); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=*/7ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul); for (procid = 0; procid < 4; procid++) { if (fork() == 0) { loop(); } } sleep(1000000); return 0; } =* repro.txt =* r0 = syz_usb_connect$hid(0x0, 0x36, &(0x7f0000000040)=ANY=[@ANYBLOB="12010000000018105e04da070700000000010902240001000000000904000009030000000921000000012222000905810308"], 0x0) syz_usb_control_io$hid(r0, 0x0, 0x0) syz_usb_control_io$hid(r0, &(0x7f00000001c0)={0x24, 0x0, 0x0, &(0x7f0000000080)=ANY=[@ANYBLOB="00222200000096231306e53f070cad00002a9001070900de0083"], 0x0}, 0x0) and see also in https://gist.github.com/xrivendell7/89889ed8dd8565675b11816a6aa1fbc3 I hope it helps. Merry Christmas! xingwei Lee