text: // kernel BUG at net/rxrpc/local_object.c:LINE!
  // https://syzkaller.appspot.com/bug?id=c92aa0a33fd6b7bd312ad063d4d13d525417cb36
  // status:open
  // autogenerated by syzkaller (https://github.com/google/syzkaller)
  
  #define _GNU_SOURCE
  
  #include <dirent.h>
  #include <endian.h>
  #include <errno.h>
  #include <fcntl.h>
  #include <sched.h>
  #include <signal.h>
  #include <stdarg.h>
  #include <stdbool.h>
  #include <stdint.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <sys/ioctl.h>
  #include <sys/mount.h>
  #include <sys/prctl.h>
  #include <sys/resource.h>
  #include <sys/stat.h>
  #include <sys/syscall.h>
  #include <sys/time.h>
  #include <sys/types.h>
  #include <sys/wait.h>
  #include <time.h>
  #include <unistd.h>
  
  #include <linux/capability.h>
  
  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 void use_temporary_dir(void)
  {
    char tmpdir_template[] = "./syzkaller.XXXXXX";
    char* tmpdir = mkdtemp(tmpdir_template);
    if (!tmpdir)
      exit(1);
    if (chmod(tmpdir, 0777))
      exit(1);
    if (chdir(tmpdir))
      exit(1);
  }
  
  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 void setup_common()
  {
    if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) {
    }
  }
  
  static void loop();
  
  static void sandbox_common()
  {
    prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
    setpgrp();
    setsid();
    struct rlimit rlim;
    rlim.rlim_cur = rlim.rlim_max = (200 << 20);
    setrlimit(RLIMIT_AS, &rlim);
    rlim.rlim_cur = rlim.rlim_max = 32 << 20;
    setrlimit(RLIMIT_MEMLOCK, &rlim);
    rlim.rlim_cur = rlim.rlim_max = 136 << 20;
    setrlimit(RLIMIT_FSIZE, &rlim);
    rlim.rlim_cur = rlim.rlim_max = 1 << 20;
    setrlimit(RLIMIT_STACK, &rlim);
    rlim.rlim_cur = rlim.rlim_max = 0;
    setrlimit(RLIMIT_CORE, &rlim);
    rlim.rlim_cur = rlim.rlim_max = 256;
    setrlimit(RLIMIT_NOFILE, &rlim);
    if (unshare(CLONE_NEWNS)) {
    }
    if (unshare(CLONE_NEWIPC)) {
    }
    if (unshare(0x02000000)) {
    }
    if (unshare(CLONE_NEWUTS)) {
    }
    if (unshare(CLONE_SYSVSEM)) {
    }
    typedef struct {
      const char* name;
      const char* value;
    } sysctl_t;
    static const sysctl_t sysctls[] = {
        {"/proc/sys/kernel/shmmax", "16777216"},
        {"/proc/sys/kernel/shmall", "536870912"},
        {"/proc/sys/kernel/shmmni", "1024"},
        {"/proc/sys/kernel/msgmax", "8192"},
        {"/proc/sys/kernel/msgmni", "1024"},
        {"/proc/sys/kernel/msgmnb", "1024"},
        {"/proc/sys/kernel/sem", "1024 1048576 500 1024"},
    };
    unsigned i;
    for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++)
      write_file(sysctls[i].name, sysctls[i].value);
  }
  
  int wait_for_loop(int pid)
  {
    if (pid < 0)
      exit(1);
    int status = 0;
    while (waitpid(-1, &status, __WALL) != pid) {
    }
    return WEXITSTATUS(status);
  }
  
  static void drop_caps(void)
  {
    struct __user_cap_header_struct cap_hdr = {};
    struct __user_cap_data_struct cap_data[2] = {};
    cap_hdr.version = _LINUX_CAPABILITY_VERSION_3;
    cap_hdr.pid = getpid();
    if (syscall(SYS_capget, &cap_hdr, &cap_data))
      exit(1);
    const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE);
    cap_data[0].effective &= ~drop;
    cap_data[0].permitted &= ~drop;
    cap_data[0].inheritable &= ~drop;
    if (syscall(SYS_capset, &cap_hdr, &cap_data))
      exit(1);
  }
  
  static int do_sandbox_none(void)
  {
    if (unshare(CLONE_NEWPID)) {
    }
    int pid = fork();
    if (pid != 0)
      return wait_for_loop(pid);
    setup_common();
    sandbox_common();
    drop_caps();
    if (unshare(CLONE_NEWNET)) {
    }
    loop();
    exit(1);
  }
  
  #define FS_IOC_SETFLAGS _IOW('f', 2, long)
  static void remove_dir(const char* dir)
  {
    DIR* dp;
    struct dirent* ep;
    int iter = 0;
  retry:
    while (umount2(dir, MNT_DETACH) == 0) {
    }
    dp = opendir(dir);
    if (dp == NULL) {
      if (errno == EMFILE) {
        exit(1);
      }
      exit(1);
    }
    while ((ep = readdir(dp))) {
      if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0)
        continue;
      char filename[FILENAME_MAX];
      snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name);
      while (umount2(filename, MNT_DETACH) == 0) {
      }
      struct stat st;
      if (lstat(filename, &st))
        exit(1);
      if (S_ISDIR(st.st_mode)) {
        remove_dir(filename);
        continue;
      }
      int i;
      for (i = 0;; i++) {
        if (unlink(filename) == 0)
          break;
        if (errno == EPERM) {
          int fd = open(filename, O_RDONLY);
          if (fd != -1) {
            long flags = 0;
            if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0)
              close(fd);
            continue;
          }
        }
        if (errno == EROFS) {
          break;
        }
        if (errno != EBUSY || i > 100)
          exit(1);
        if (umount2(filename, MNT_DETACH))
          exit(1);
      }
    }
    closedir(dp);
    int i;
    for (i = 0;; i++) {
      if (rmdir(dir) == 0)
        break;
      if (i < 100) {
        if (errno == EPERM) {
          int fd = open(dir, O_RDONLY);
          if (fd != -1) {
            long flags = 0;
            if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0)
              close(fd);
            continue;
          }
        }
        if (errno == EROFS) {
          break;
        }
        if (errno == EBUSY) {
          if (umount2(dir, MNT_DETACH))
            exit(1);
          continue;
        }
        if (errno == ENOTEMPTY) {
          if (iter < 100) {
            iter++;
            goto retry;
          }
        }
      }
      exit(1);
    }
  }
  
  static void kill_and_wait(int pid, int* status)
  {
    kill(-pid, SIGKILL);
    kill(pid, SIGKILL);
    int i;
    for (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 close_fds()
  {
    int fd;
    for (fd = 3; fd < 30; fd++)
      close(fd);
  }
  
  static void execute_one(void);
  
  #define WAIT_FLAGS __WALL
  
  static void loop(void)
  {
    int iter;
    for (iter = 0;; iter++) {
      char cwdbuf[32];
      sprintf(cwdbuf, "./%d", iter);
      if (mkdir(cwdbuf, 0777))
        exit(1);
      int pid = fork();
      if (pid < 0)
        exit(1);
      if (pid == 0) {
        if (chdir(cwdbuf))
          exit(1);
        setup_test();
        execute_one();
        close_fds();
        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 < 5 * 1000)
          continue;
        kill_and_wait(pid, &status);
        break;
      }
      remove_dir(cwdbuf);
    }
  }
  
  uint64_t r[1] = {0xffffffffffffffff};
  
  void execute_one(void)
  {
    intptr_t res = 0;
    res = syscall(__NR_socket, 0x2000000000000021, 2, 2);
    if (res != -1)
      r[0] = res;
    *(uint16_t*)0x20000080 = 0x21;
    *(uint16_t*)0x20000082 = 0;
    *(uint16_t*)0x20000084 = 2;
    *(uint16_t*)0x20000086 = 0x10;
    *(uint16_t*)0x20000088 = 2;
    *(uint16_t*)0x2000008a = htobe16(0x4e24);
    *(uint8_t*)0x2000008c = 0xac;
    *(uint8_t*)0x2000008d = 0x14;
    *(uint8_t*)0x2000008e = 0x14;
    *(uint8_t*)0x2000008f = 0x1e;
    syscall(__NR_connect, r[0], 0x20000080, 0x24);
    *(uint64_t*)0x20005c00 = 0;
    *(uint32_t*)0x20005c08 = 0;
    *(uint64_t*)0x20005c10 = 0;
    *(uint64_t*)0x20005c18 = 0;
    *(uint64_t*)0x20005c20 = 0x20000000;
    *(uint64_t*)0x20000000 = 0x18;
    *(uint32_t*)0x20000008 = 0x110;
    *(uint32_t*)0x2000000c = 1;
    memcpy((void*)0x20000010, "w", 1);
    *(uint64_t*)0x20005c28 = 0x18;
    *(uint32_t*)0x20005c30 = 0;
    *(uint32_t*)0x20005c38 = 0;
    syscall(__NR_sendmmsg, r[0], 0x20005c00, 1, 0);
    memcpy((void*)0x20000000, "./file0\000", 8);
    syscall(__NR_mkdir, 0x20000000, 0);
    memcpy((void*)0x200000c0, "./file0\000", 8);
    syscall(__NR_mount, 0x20000000, 0x200000c0, 0, 0x2001001, 0);
    memcpy((void*)0x20000500, "./file0\000", 8);
    memcpy((void*)0x20000100, "./file0\000", 8);
    syscall(__NR_pivot_root, 0x20000500, 0x20000100);
  }
  int main(void)
  {
    syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
    for (procid = 0; procid < 6; procid++) {
      if (fork() == 0) {
        use_temporary_dir();
        do_sandbox_none();
      }
    }
    sleep(1000000);
    return 0;
  }
  