// https://syzkaller.appspot.com/bug?id=e1b5cfc4d5f351d479d66e3c91ddf926d503b1ef
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.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>

#include <linux/futex.h>

#ifndef __NR_io_uring_setup
#define __NR_io_uring_setup 425
#endif

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 void thread_start(void* (*fn)(void*), void* arg)
{
  pthread_t th;
  pthread_attr_t attr;
  pthread_attr_init(&attr);
  pthread_attr_setstacksize(&attr, 128 << 10);
  int i = 0;
  for (; i < 100; i++) {
    if (pthread_create(&th, &attr, fn, arg) == 0) {
      pthread_attr_destroy(&attr);
      return;
    }
    if (errno == EAGAIN) {
      usleep(50);
      continue;
    }
    break;
  }
  exit(1);
}

typedef struct {
  int state;
} event_t;

static void event_init(event_t* ev)
{
  ev->state = 0;
}

static void event_reset(event_t* ev)
{
  ev->state = 0;
}

static void event_set(event_t* ev)
{
  if (ev->state)
    exit(1);
  __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE);
  syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000);
}

static void event_wait(event_t* ev)
{
  while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0);
}

static int event_isset(event_t* ev)
{
  return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE);
}

static int event_timedwait(event_t* ev, uint64_t timeout)
{
  uint64_t start = current_time_ms();
  uint64_t now = start;
  for (;;) {
    uint64_t remain = timeout - (now - start);
    struct timespec ts;
    ts.tv_sec = remain / 1000;
    ts.tv_nsec = (remain % 1000) * 1000 * 1000;
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts);
    if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
      return 1;
    now = current_time_ms();
    if (now - start > timeout)
      return 0;
  }
}

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 SIZEOF_IO_URING_SQE 64
#define SIZEOF_IO_URING_CQE 16
#define SQ_HEAD_OFFSET 0
#define SQ_TAIL_OFFSET 64
#define SQ_RING_MASK_OFFSET 256
#define SQ_RING_ENTRIES_OFFSET 264
#define SQ_FLAGS_OFFSET 276
#define SQ_DROPPED_OFFSET 272
#define CQ_HEAD_OFFSET 128
#define CQ_TAIL_OFFSET 192
#define CQ_RING_MASK_OFFSET 260
#define CQ_RING_ENTRIES_OFFSET 268
#define CQ_RING_OVERFLOW_OFFSET 284
#define CQ_FLAGS_OFFSET 280
#define CQ_CQES_OFFSET 320

struct io_sqring_offsets {
  uint32_t head;
  uint32_t tail;
  uint32_t ring_mask;
  uint32_t ring_entries;
  uint32_t flags;
  uint32_t dropped;
  uint32_t array;
  uint32_t resv1;
  uint64_t resv2;
};

struct io_cqring_offsets {
  uint32_t head;
  uint32_t tail;
  uint32_t ring_mask;
  uint32_t ring_entries;
  uint32_t overflow;
  uint32_t cqes;
  uint64_t resv[2];
};

struct io_uring_params {
  uint32_t sq_entries;
  uint32_t cq_entries;
  uint32_t flags;
  uint32_t sq_thread_cpu;
  uint32_t sq_thread_idle;
  uint32_t features;
  uint32_t resv[4];
  struct io_sqring_offsets sq_off;
  struct io_cqring_offsets cq_off;
};

#define IORING_OFF_SQ_RING 0
#define IORING_OFF_SQES 0x10000000ULL
#define IORING_SETUP_SQE128 (1U << 10)
#define IORING_SETUP_CQE32 (1U << 11)

static long syz_io_uring_setup(volatile long a0, volatile long a1,
                               volatile long a2, volatile long a3)
{
  uint32_t entries = (uint32_t)a0;
  struct io_uring_params* setup_params = (struct io_uring_params*)a1;
  void** ring_ptr_out = (void**)a2;
  void** sqes_ptr_out = (void**)a3;
  setup_params->flags &= ~(IORING_SETUP_CQE32 | IORING_SETUP_SQE128);
  uint32_t fd_io_uring = syscall(__NR_io_uring_setup, entries, setup_params);
  uint32_t sq_ring_sz =
      setup_params->sq_off.array + setup_params->sq_entries * sizeof(uint32_t);
  uint32_t cq_ring_sz = setup_params->cq_off.cqes +
                        setup_params->cq_entries * SIZEOF_IO_URING_CQE;
  uint32_t ring_sz = sq_ring_sz > cq_ring_sz ? sq_ring_sz : cq_ring_sz;
  *ring_ptr_out =
      mmap(0, ring_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
           fd_io_uring, IORING_OFF_SQ_RING);
  uint32_t sqes_sz = setup_params->sq_entries * SIZEOF_IO_URING_SQE;
  *sqes_ptr_out = mmap(0, sqes_sz, PROT_READ | PROT_WRITE,
                       MAP_SHARED | MAP_POPULATE, fd_io_uring, IORING_OFF_SQES);
  uint32_t* array =
      (uint32_t*)((uintptr_t)*ring_ptr_out + setup_params->sq_off.array);
  for (uint32_t index = 0; index < entries; index++)
    array[index] = index;
  return fd_io_uring;
}

static long syz_memcpy_off(volatile long a0, volatile long a1, volatile long a2,
                           volatile long a3, volatile long a4)
{
  char* dest = (char*)a0;
  uint32_t dest_off = (uint32_t)a1;
  char* src = (char*)a2;
  uint32_t src_off = (uint32_t)a3;
  size_t n = (size_t)a4;
  return (long)memcpy(dest + dest_off, src + src_off, n);
}

static long syz_open_procfs(volatile long a0, volatile long a1)
{
  char buf[128];
  memset(buf, 0, sizeof(buf));
  if (a0 == 0) {
    snprintf(buf, sizeof(buf), "/proc/self/%s", (char*)a1);
  } else if (a0 == -1) {
    snprintf(buf, sizeof(buf), "/proc/thread-self/%s", (char*)a1);
  } else {
    snprintf(buf, sizeof(buf), "/proc/self/task/%d/%s", (int)a0, (char*)a1);
  }
  int fd = open(buf, O_RDWR);
  if (fd == -1)
    fd = open(buf, O_RDONLY);
  return fd;
}

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");
}

struct thread_t {
  int created, call;
  event_t ready, done;
};

static struct thread_t threads[16];
static void execute_call(int call);
static int running;

static void* thr(void* arg)
{
  struct thread_t* th = (struct thread_t*)arg;
  for (;;) {
    event_wait(&th->ready);
    event_reset(&th->ready);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    event_set(&th->done);
  }
  return 0;
}

static void execute_one(void)
{
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  int i, call, thread;
  for (call = 0; call < 5; call++) {
    for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0]));
         thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        event_init(&th->ready);
        event_init(&th->done);
        event_set(&th->done);
        thread_start(thr, th);
      }
      if (!event_isset(&th->done))
        continue;
      event_reset(&th->done);
      th->call = call;
      __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
      event_set(&th->ready);
      event_timedwait(&th->done, 50);
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
}

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 (;;) {
      sleep_ms(10);
      if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
        break;
      if (current_time_ms() - start < 5000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
  }
}

uint64_t r[2] = {0x0, 0xffffffffffffffff};

void execute_call(int call)
{
  intptr_t res = 0;
  switch (call) {
  case 0:
    //  syz_io_uring_setup arguments: [
    //    entries: int32 = 0x10a (4 bytes)
    //    params: ptr[inout, io_uring_params] {
    //      io_uring_params {
    //        sq_entries: int32 = 0x0 (4 bytes)
    //        cq_entries: int32 = 0x5883 (4 bytes)
    //        flags: io_uring_setup_flags = 0x8 (4 bytes)
    //        sq_thread_cpu: int32 = 0x1 (4 bytes)
    //        sq_thread_idle: int32 = 0xfffffdfc (4 bytes)
    //        features: int32 = 0x0 (4 bytes)
    //        wq_fd: fd_io_uring (resource)
    //        resv: buffer: {00 00 00 00 00 00 00 00 00 00 00 00} (length 0xc)
    //        sq_off: array[int32] {
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //        }
    //        cq_off: array[int32] {
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //          int32 = 0x0 (4 bytes)
    //        }
    //      }
    //    }
    //    ring_ptr: ptr[out, ring_ptr] {
    //      ring_ptr (resource)
    //    }
    //    sqes_ptr: ptr[out, sqes_ptr] {
    //      sqes_ptr (resource)
    //    }
    //  ]
    //  returns fd_io_uring
    *(uint32_t*)0x200000000144 = 0x5883;
    *(uint32_t*)0x200000000148 = 8;
    *(uint32_t*)0x20000000014c = 1;
    *(uint32_t*)0x200000000150 = 0xfffffdfc;
    *(uint32_t*)0x200000000158 = -1;
    memset((void*)0x20000000015c, 0, 12);
    res = -1;
    res = syz_io_uring_setup(/*entries=*/0x10a, /*params=*/0x200000000140,
                             /*ring_ptr=*/0x2000000000c0,
                             /*sqes_ptr=*/0x200000000000);
    if (res != -1)
      r[0] = *(uint64_t*)0x2000000000c0;
    break;
  case 1:
    //  pselect6 arguments: [
    //    n: len = 0x0 (8 bytes)
    //    inp: nil
    //    outp: nil
    //    exp: nil
    //    tvp: nil
    //    sig: nil
    //  ]
    syscall(__NR_pselect6, /*n=*/0ul, /*inp=*/0ul, /*outp=*/0ul, /*exp=*/0ul,
            /*tvp=*/0ul, /*sig=*/0ul);
    break;
  case 2:
    //  syz_memcpy_off$IO_URING_METADATA_GENERIC arguments: [
    //    ring_ptr: ring_ptr (resource)
    //    off: io_uring_offsets = 0x4 (8 bytes)
    //    src: ptr[in, int32] {
    //      int32 = 0xfffffffc (4 bytes)
    //    }
    //    src_off: const = 0x0 (8 bytes)
    //    nbytes: const = 0x4 (8 bytes)
    //  ]
    *(uint32_t*)0x200000000080 = 0xfffffffc;
    syz_memcpy_off(/*ring_ptr=*/r[0], /*off=*/4, /*src=*/0x200000000080,
                   /*src_off=*/0, /*nbytes=*/4);
    break;
  case 3:
    //  syz_open_procfs arguments: [
    //    pid: pid (resource)
    //    file: ptr[in, buffer] {
    //      buffer: {66 64 69 6e 66 6f 2f 33 00} (length 0x9)
    //    }
    //  ]
    //  returns fd
    memcpy((void*)0x2000000002c0, "fdinfo/3\000", 9);
    res = -1;
    res = syz_open_procfs(/*pid=*/0, /*file=*/0x2000000002c0);
    if (res != -1)
      r[1] = res;
    break;
  case 4:
    //  read$FUSE arguments: [
    //    fd: fd_fuse (resource)
    //    buf: ptr[out, fuse_in[read_buffer]] {
    //      fuse_in[read_buffer] {
    //        len: len = 0x2020 (4 bytes)
    //        opcode: int32 = 0x0 (4 bytes)
    //        unique: fuse_unique (resource)
    //        uid: uid (resource)
    //        gid: gid (resource)
    //        pid: pid (resource)
    //        padding: int32 = 0x0 (4 bytes)
    //        payload: buffer: (DirOut)
    //      }
    //    }
    //    len: bytesize = 0x2020 (8 bytes)
    //  ]
    syscall(__NR_read, /*fd=*/r[1], /*buf=*/0x2000000040c0ul, /*len=*/0x2020ul);
    break;
  }
}
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;
  loop();
  return 0;
}