syzkaller-repros/linux/483576ccee65fe1983c87f6518df79939853ca5f.c

// kernel BUG at net/core/skbuff.c:LINE!
// https://syzkaller.appspot.com/bug?id=483576ccee65fe1983c87f6518df79939853ca5f
// 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 <pthread.h>
#include <signal.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 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);
  if (pthread_create(&th, &attr, fn, arg))
    exit(1);
  pthread_attr_destroy(&attr);
}

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);
}

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_RELAXED))
      return 1;
    now = current_time_ms();
    if (now - start > timeout)
      return 0;
  }
}

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) {
  }
}

#define SYZ_HAVE_SETUP_TEST 1
static void setup_test()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
}

#define SYZ_HAVE_RESET_TEST 1
static void reset_test()
{
  int fd;
  for (fd = 3; fd < 30; fd++)
    close(fd);
}

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)
{
  int i, call, thread;
  int collide = 0;
again:
  for (call = 0; call < 6; 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);
      if (collide && (call % 2) == 0)
        break;
      event_timedwait(&th->done, 45);
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
  if (!collide) {
    collide = 1;
    goto again;
  }
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  int iter;
  for (iter = 0;; iter++) {
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      setup_test();
      execute_one();
      reset_test();
      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;
    }
  }
}

uint64_t r[1] = {0xffffffffffffffff};

void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    res = syscall(__NR_socket, 0xa, 3, 0x3c);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    *(uint16_t*)0x20000300 = 0xa;
    *(uint16_t*)0x20000302 = htobe16(0);
    *(uint32_t*)0x20000304 = 0;
    *(uint64_t*)0x20000308 = htobe64(0);
    *(uint64_t*)0x20000310 = htobe64(1);
    *(uint32_t*)0x20000318 = 0;
    syscall(__NR_connect, r[0], 0x20000300, 0x1c);
    break;
  case 2:
    *(uint64_t*)0x200000c0 = 0;
    *(uint32_t*)0x200000c8 = 0;
    *(uint64_t*)0x200000d0 = 0x20000200;
    *(uint64_t*)0x200000d8 = 0;
    *(uint64_t*)0x200000e0 = 0x20000140;
    *(uint64_t*)0x200000e8 = 0;
    *(uint32_t*)0x200000f0 = 0;
    syscall(__NR_sendmsg, r[0], 0x200000c0, 0xc100);
    break;
  case 3:
    *(uint64_t*)0x20000380 = 0;
    *(uint32_t*)0x20000388 = 0;
    *(uint64_t*)0x20000390 = 0x20000240;
    *(uint64_t*)0x20000240 = 0x20000140;
    memcpy((void*)0x20000140, "\xb1\x0b\x93\x86", 4);
    *(uint64_t*)0x20000248 = 4;
    *(uint64_t*)0x20000398 = 1;
    *(uint64_t*)0x200003a0 = 0x20000200;
    *(uint64_t*)0x200003a8 = 0;
    *(uint32_t*)0x200003b0 = 0;
    syscall(__NR_sendmsg, r[0], 0x20000380, 0);
    break;
  case 4:
    *(uint32_t*)0x20000280 = 0xe2e;
    syscall(__NR_setsockopt, r[0], 0x29, 0x4a, 0x20000280, 4);
    break;
  case 5:
    *(uint64_t*)0x20006780 = 0x20000000;
    *(uint32_t*)0x20006788 = 0x80;
    *(uint64_t*)0x20006790 = 0x20000080;
    *(uint64_t*)0x20000080 = 0x200006c0;
    *(uint64_t*)0x20000088 = 0x1000;
    *(uint64_t*)0x20000090 = 0x20000180;
    *(uint64_t*)0x20000098 = 0xb3;
    *(uint64_t*)0x20006798 = 2;
    *(uint64_t*)0x200067a0 = 0x200003c0;
    *(uint64_t*)0x200067a8 = 0x47;
    *(uint32_t*)0x200067b0 = 8;
    *(uint32_t*)0x200067b8 = 0x4f82;
    *(uint64_t*)0x200067c0 = 0x20000500;
    *(uint32_t*)0x200067c8 = 0x80;
    *(uint64_t*)0x200067d0 = 0x20001940;
    *(uint64_t*)0x20001940 = 0x200016c0;
    *(uint64_t*)0x20001948 = 0xfe;
    *(uint64_t*)0x20001950 = 0x20000580;
    *(uint64_t*)0x20001958 = 0x57;
    *(uint64_t*)0x20001960 = 0x200017c0;
    *(uint64_t*)0x20001968 = 0xfd;
    *(uint64_t*)0x20001970 = 0x200018c0;
    *(uint64_t*)0x20001978 = 0x7f;
    *(uint64_t*)0x20001980 = 0x20000100;
    *(uint64_t*)0x20001988 = 0x3d;
    *(uint64_t*)0x200067d8 = 5;
    *(uint64_t*)0x200067e0 = 0x200019c0;
    *(uint64_t*)0x200067e8 = 0xc6;
    *(uint32_t*)0x200067f0 = 2;
    *(uint32_t*)0x200067f8 = 0x7f;
    *(uint64_t*)0x20006800 = 0x20001ac0;
    *(uint32_t*)0x20006808 = 0x80;
    *(uint64_t*)0x20006810 = 0x20001d80;
    *(uint64_t*)0x20001d80 = 0x20001b40;
    *(uint64_t*)0x20001d88 = 0x69;
    *(uint64_t*)0x20001d90 = 0x20001bc0;
    *(uint64_t*)0x20001d98 = 0x88;
    *(uint64_t*)0x20001da0 = 0x20001c80;
    *(uint64_t*)0x20001da8 = 0x5c;
    *(uint64_t*)0x20001db0 = 0x200002c0;
    *(uint64_t*)0x20001db8 = 0x39;
    *(uint64_t*)0x20001dc0 = 0x20001d00;
    *(uint64_t*)0x20001dc8 = 0x74;
    *(uint64_t*)0x20001dd0 = 0x20000340;
    *(uint64_t*)0x20001dd8 = 0x27;
    *(uint64_t*)0x20001de0 = 0x20000440;
    *(uint64_t*)0x20001de8 = 0xf;
    *(uint64_t*)0x20006818 = 7;
    *(uint64_t*)0x20006820 = 0x20001e00;
    *(uint64_t*)0x20006828 = 0xc0;
    *(uint32_t*)0x20006830 = 0x80000001;
    *(uint32_t*)0x20006838 = 2;
    *(uint64_t*)0x20006840 = 0x20001ec0;
    *(uint32_t*)0x20006848 = 0x80;
    *(uint64_t*)0x20006850 = 0x200031c0;
    *(uint64_t*)0x200031c0 = 0x20000600;
    *(uint64_t*)0x200031c8 = 9;
    *(uint64_t*)0x200031d0 = 0x20001f40;
    *(uint64_t*)0x200031d8 = 0x8b;
    *(uint64_t*)0x200031e0 = 0x20002000;
    *(uint64_t*)0x200031e8 = 0x65;
    *(uint64_t*)0x200031f0 = 0x20002080;
    *(uint64_t*)0x200031f8 = 0x8e;
    *(uint64_t*)0x20003200 = 0x20002140;
    *(uint64_t*)0x20003208 = 0x5a;
    *(uint64_t*)0x20003210 = 0x200021c0;
    *(uint64_t*)0x20003218 = 0x1000;
    *(uint64_t*)0x20006858 = 6;
    *(uint64_t*)0x20006860 = 0x20003240;
    *(uint64_t*)0x20006868 = 0x24;
    *(uint32_t*)0x20006870 = 0x7fff;
    *(uint32_t*)0x20006878 = 1;
    *(uint64_t*)0x20006880 = 0x20003280;
    *(uint32_t*)0x20006888 = 0x80;
    *(uint64_t*)0x20006890 = 0x200033c0;
    *(uint64_t*)0x200033c0 = 0x20003300;
    *(uint64_t*)0x200033c8 = 0x94;
    *(uint64_t*)0x20006898 = 1;
    *(uint64_t*)0x200068a0 = 0x20003400;
    *(uint64_t*)0x200068a8 = 0x1000;
    *(uint32_t*)0x200068b0 = 0x200;
    *(uint32_t*)0x200068b8 = 0;
    *(uint64_t*)0x200068c0 = 0;
    *(uint32_t*)0x200068c8 = 0;
    *(uint64_t*)0x200068d0 = 0x20005700;
    *(uint64_t*)0x20005700 = 0x20004400;
    *(uint64_t*)0x20005708 = 8;
    *(uint64_t*)0x20005710 = 0x20004440;
    *(uint64_t*)0x20005718 = 0x1000;
    *(uint64_t*)0x20005720 = 0x20005440;
    *(uint64_t*)0x20005728 = 0x10;
    *(uint64_t*)0x20005730 = 0x20005480;
    *(uint64_t*)0x20005738 = 0x6f;
    *(uint64_t*)0x20005740 = 0x20005500;
    *(uint64_t*)0x20005748 = 0x8e;
    *(uint64_t*)0x20005750 = 0x200055c0;
    *(uint64_t*)0x20005758 = 0x31;
    *(uint64_t*)0x20005760 = 0x20005600;
    *(uint64_t*)0x20005768 = 0xe4;
    *(uint64_t*)0x200068d8 = 7;
    *(uint64_t*)0x200068e0 = 0x20005780;
    *(uint64_t*)0x200068e8 = 0x1000;
    *(uint32_t*)0x200068f0 = 1;
    *(uint32_t*)0x200068f8 = 1;
    *(uint64_t*)0x20006900 = 0;
    *(uint64_t*)0x20006908 = 0;
    syscall(__NR_recvmmsg, r[0], 0x20006780, 6, 2, 0x20006900);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  loop();
  return 0;
}