// https://syzkaller.appspot.com/bug?id=6046abc8536bc302324e07a6aeae6e6008053c18
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

#ifndef __NR_ioctl
#define __NR_ioctl 29
#endif
#ifndef __NR_mmap
#define __NR_mmap 222
#endif

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;
}

uint64_t r[1] = {0xffffffffffffffff};

int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x20000000ul, /*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=*/0x21000000ul, /*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)) {
  }
  //  syz_open_procfs$namespace arguments: [
  //    pid: pid (resource)
  //    file: ptr[in, buffer] {
  //      buffer: {6e 73 2f 75 73 65 72 00} (length 0x8)
  //    }
  //  ]
  //  returns fd_namespace
  memcpy((void*)0x20000040, "ns/user\000", 8);
  res = -1;
  res = syz_open_procfs(/*pid=*/0, /*file=*/0x20000040);
  if (res != -1)
    r[0] = res;
  //  ioctl$TUNSETFILTEREBPF arguments: [
  //    fd: fd_tun (resource)
  //    cmd: const = 0xb704 (4 bytes)
  //    arg: nil
  //  ]
  syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0xb704, /*arg=*/0ul);
  return 0;
}