// https://syzkaller.appspot.com/bug?id=833e9c2f24710d6ca275451770a7693aca5f7339
// 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 <setjmp.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/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>

static unsigned long long procid;

static __thread int clone_ongoing;
static __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* ctx)
{
  if (__atomic_load_n(&clone_ongoing, __ATOMIC_RELAXED) != 0) {
    exit(sig);
  }
  uintptr_t addr = (uintptr_t)info->si_addr;
  const uintptr_t prog_start = 1 << 20;
  const uintptr_t prog_end = 100 << 20;
  int skip = __atomic_load_n(&skip_segv, __ATOMIC_RELAXED) != 0;
  int valid = addr < prog_start || addr > prog_end;
  if (skip && valid) {
    _longjmp(segv_env, 1);
  }
  exit(sig);
}

static void install_segv_handler(void)
{
  struct sigaction sa;
  memset(&sa, 0, sizeof(sa));
  sa.sa_handler = SIG_IGN;
  syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8);
  syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8);
  memset(&sa, 0, sizeof(sa));
  sa.sa_sigaction = segv_handler;
  sa.sa_flags = SA_NODEFER | SA_SIGINFO;
  sigaction(SIGSEGV, &sa, NULL);
  sigaction(SIGBUS, &sa, NULL);
}

#define NONFAILING(...)                                                        \
  ({                                                                           \
    int ok = 1;                                                                \
    __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    if (_setjmp(segv_env) == 0) {                                              \
      __VA_ARGS__;                                                             \
    } else                                                                     \
      ok = 0;                                                                  \
    __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    ok;                                                                        \
  })

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;
}

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 {
    char buf[1024];
    char* hash;
    strncpy(buf, (char*)a0, sizeof(buf) - 1);
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(a1 % 10);
      a1 /= 10;
    }
    return open(buf, a2, 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");
}

#define FUSE_MIN_READ_BUFFER 8192
enum fuse_opcode {
  FUSE_LOOKUP = 1,
  FUSE_FORGET = 2,
  FUSE_GETATTR = 3,
  FUSE_SETATTR = 4,
  FUSE_READLINK = 5,
  FUSE_SYMLINK = 6,
  FUSE_MKNOD = 8,
  FUSE_MKDIR = 9,
  FUSE_UNLINK = 10,
  FUSE_RMDIR = 11,
  FUSE_RENAME = 12,
  FUSE_LINK = 13,
  FUSE_OPEN = 14,
  FUSE_READ = 15,
  FUSE_WRITE = 16,
  FUSE_STATFS = 17,
  FUSE_RELEASE = 18,
  FUSE_FSYNC = 20,
  FUSE_SETXATTR = 21,
  FUSE_GETXATTR = 22,
  FUSE_LISTXATTR = 23,
  FUSE_REMOVEXATTR = 24,
  FUSE_FLUSH = 25,
  FUSE_INIT = 26,
  FUSE_OPENDIR = 27,
  FUSE_READDIR = 28,
  FUSE_RELEASEDIR = 29,
  FUSE_FSYNCDIR = 30,
  FUSE_GETLK = 31,
  FUSE_SETLK = 32,
  FUSE_SETLKW = 33,
  FUSE_ACCESS = 34,
  FUSE_CREATE = 35,
  FUSE_INTERRUPT = 36,
  FUSE_BMAP = 37,
  FUSE_DESTROY = 38,
  FUSE_IOCTL = 39,
  FUSE_POLL = 40,
  FUSE_NOTIFY_REPLY = 41,
  FUSE_BATCH_FORGET = 42,
  FUSE_FALLOCATE = 43,
  FUSE_READDIRPLUS = 44,
  FUSE_RENAME2 = 45,
  FUSE_LSEEK = 46,
  FUSE_COPY_FILE_RANGE = 47,
  FUSE_SETUPMAPPING = 48,
  FUSE_REMOVEMAPPING = 49,
  FUSE_SYNCFS = 50,
  FUSE_TMPFILE = 51,
  FUSE_STATX = 52,
  CUSE_INIT = 4096,
  CUSE_INIT_BSWAP_RESERVED = 1048576,
  FUSE_INIT_BSWAP_RESERVED = 436207616,
};
struct fuse_in_header {
  uint32_t len;
  uint32_t opcode;
  uint64_t unique;
  uint64_t nodeid;
  uint32_t uid;
  uint32_t gid;
  uint32_t pid;
  uint32_t padding;
};
struct fuse_out_header {
  uint32_t len;
  uint32_t error;
  uint64_t unique;
};
struct syz_fuse_req_out {
  struct fuse_out_header* init;
  struct fuse_out_header* lseek;
  struct fuse_out_header* bmap;
  struct fuse_out_header* poll;
  struct fuse_out_header* getxattr;
  struct fuse_out_header* lk;
  struct fuse_out_header* statfs;
  struct fuse_out_header* write;
  struct fuse_out_header* read;
  struct fuse_out_header* open;
  struct fuse_out_header* attr;
  struct fuse_out_header* entry;
  struct fuse_out_header* dirent;
  struct fuse_out_header* direntplus;
  struct fuse_out_header* create_open;
  struct fuse_out_header* ioctl;
  struct fuse_out_header* statx;
};
static int fuse_send_response(int fd, const struct fuse_in_header* in_hdr,
                              struct fuse_out_header* out_hdr)
{
  if (!out_hdr) {
    return -1;
  }
  out_hdr->unique = in_hdr->unique;
  if (write(fd, out_hdr, out_hdr->len) == -1) {
    return -1;
  }
  return 0;
}
static volatile long syz_fuse_handle_req(volatile long a0, volatile long a1,
                                         volatile long a2, volatile long a3)
{
  struct syz_fuse_req_out* req_out = (struct syz_fuse_req_out*)a3;
  struct fuse_out_header* out_hdr = NULL;
  char* buf = (char*)a1;
  int buf_len = (int)a2;
  int fd = (int)a0;
  if (!req_out) {
    return -1;
  }
  if (buf_len < FUSE_MIN_READ_BUFFER) {
    return -1;
  }
  int ret = read(fd, buf, buf_len);
  if (ret == -1) {
    return -1;
  }
  if ((size_t)ret < sizeof(struct fuse_in_header)) {
    return -1;
  }
  const struct fuse_in_header* in_hdr = (const struct fuse_in_header*)buf;
  if (in_hdr->len > (uint32_t)ret) {
    return -1;
  }
  switch (in_hdr->opcode) {
  case FUSE_GETATTR:
  case FUSE_SETATTR:
    out_hdr = req_out->attr;
    break;
  case FUSE_LOOKUP:
  case FUSE_SYMLINK:
  case FUSE_LINK:
  case FUSE_MKNOD:
  case FUSE_MKDIR:
    out_hdr = req_out->entry;
    break;
  case FUSE_OPEN:
  case FUSE_OPENDIR:
    out_hdr = req_out->open;
    break;
  case FUSE_STATFS:
    out_hdr = req_out->statfs;
    break;
  case FUSE_RMDIR:
  case FUSE_RENAME:
  case FUSE_RENAME2:
  case FUSE_FALLOCATE:
  case FUSE_SETXATTR:
  case FUSE_REMOVEXATTR:
  case FUSE_FSYNCDIR:
  case FUSE_FSYNC:
  case FUSE_SETLKW:
  case FUSE_SETLK:
  case FUSE_ACCESS:
  case FUSE_FLUSH:
  case FUSE_RELEASE:
  case FUSE_RELEASEDIR:
  case FUSE_UNLINK:
  case FUSE_DESTROY:
    out_hdr = req_out->init;
    if (!out_hdr) {
      return -1;
    }
    out_hdr->len = sizeof(struct fuse_out_header);
    break;
  case FUSE_READ:
    out_hdr = req_out->read;
    break;
  case FUSE_READDIR:
    out_hdr = req_out->dirent;
    break;
  case FUSE_READDIRPLUS:
    out_hdr = req_out->direntplus;
    break;
  case FUSE_INIT:
    out_hdr = req_out->init;
    break;
  case FUSE_LSEEK:
    out_hdr = req_out->lseek;
    break;
  case FUSE_GETLK:
    out_hdr = req_out->lk;
    break;
  case FUSE_BMAP:
    out_hdr = req_out->bmap;
    break;
  case FUSE_POLL:
    out_hdr = req_out->poll;
    break;
  case FUSE_GETXATTR:
  case FUSE_LISTXATTR:
    out_hdr = req_out->getxattr;
    break;
  case FUSE_WRITE:
  case FUSE_COPY_FILE_RANGE:
    out_hdr = req_out->write;
    break;
  case FUSE_FORGET:
  case FUSE_BATCH_FORGET:
    return 0;
  case FUSE_CREATE:
    out_hdr = req_out->create_open;
    break;
  case FUSE_IOCTL:
    out_hdr = req_out->ioctl;
    break;
  case FUSE_STATX:
    out_hdr = req_out->statx;
    break;
  default:
    return -1;
  }
  return fuse_send_response(fd, in_hdr, out_hdr);
}

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 < 11; 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] = {0xffffffffffffffff, 0xffffffffffffffff};

void execute_call(int call)
{
  intptr_t res = 0;
  switch (call) {
  case 0:
    syscall(__NR_prctl, /*option=*/0x3eul, /*cmd=*/1ul, /*pid=*/0,
            /*type=PIDTYPE_PGID*/ 2ul, /*uaddr=*/0ul);
    break;
  case 1:
    NONFAILING(memcpy((void*)0x4000000001c0, "/dev/cpu/#/msr\000", 15));
    res = -1;
    NONFAILING(res =
                   syz_open_dev(/*dev=*/0x4000000001c0, /*id=*/0, /*flags=*/0));
    if (res != -1)
      r[0] = res;
    break;
  case 2:
    syscall(__NR_read, /*fd=*/r[0], /*buf=*/0x400000019680ul,
            /*count=*/0x18ff8ul);
    break;
  case 3:
    syscall(__NR_mmap, /*addr=*/0x400000000000ul, /*len=*/0xfbe000ul,
            /*prot=PROT_SEM|PROT_WRITE|PROT_READ*/ 0xbul,
            /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_SHARED*/ 0x31ul, /*fd=*/-1,
            /*offset=*/0ul);
    break;
  case 4:
    syscall(__NR_madvise, /*addr=*/0x400000000000ul, /*len=*/0x600003ul,
            /*advice=MADV_COLLAPSE*/ 0x19ul);
    break;
  case 5:
    syscall(__NR_mbind, /*addr=*/0x400000006000ul, /*len=*/0x3000ul,
            /*mode=*/4ul, /*nodemask=*/0ul, /*maxnode=*/0ul, /*flags=*/0ul);
    break;
  case 6:
    syscall(__NR_madvise, /*addr=*/0x400000000000ul, /*len=*/0x600000ul,
            /*advice=MADV_REMOVE*/ 9ul);
    break;
  case 7:
    syscall(__NR_mbind, /*addr=*/0x400000001000ul, /*len=*/0x800000ul,
            /*mode=*/0ul, /*nodemask=*/0ul, /*maxnode=*/0ul,
            /*flags=MPOL_MF_MOVE*/ 2ul);
    break;
  case 8:
    res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0ul,
                  /*flags=*/0x42, /*mode=*/0);
    if (res != -1)
      r[1] = res;
    break;
  case 9:
    syscall(__NR_mount, /*src=*/0ul, /*dst=*/0ul, /*type=*/0ul, /*flags=*/0ul,
            /*opts=*/0ul);
    break;
  case 10:
    NONFAILING(
        syz_fuse_handle_req(/*fd=*/r[1], /*buf=*/0, /*len=*/0, /*res=*/0));
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x3ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x400000000000ul, /*len=*/0x1000000ul,
          /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x400001000000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  const char* reason;
  (void)reason;
  install_segv_handler();
  for (procid = 0; procid < 5; procid++) {
    if (fork() == 0) {
      loop();
    }
  }
  sleep(1000000);
  return 0;
}