syzkaller-repros/linux/ec324fb855382395411b32d87a6eafd5da721ecc.c

// KASAN: slab-out-of-bounds Read in sctp_getsockopt
// https://syzkaller.appspot.com/bug?id=ec324fb855382395411b32d87a6eafd5da721ecc
// status:fixed
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/syscall.h>
#include <sys/types.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;
  }
}

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 loop(void)
{
  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, 45);
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
}

uint64_t r[1] = {0xffffffffffffffff};

void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    res = syscall(__NR_socket, 2, 1, 0x84);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    memcpy((void*)0x20a34fff, "H", 1);
    *(uint16_t*)0x20030ff0 = 2;
    *(uint16_t*)0x20030ff2 = htobe16(0);
    *(uint8_t*)0x20030ff4 = 0xac;
    *(uint8_t*)0x20030ff5 = 0x14;
    *(uint8_t*)0x20030ff6 = -1;
    *(uint8_t*)0x20030ff7 = 0xaa;
    *(uint8_t*)0x20030ff8 = 0;
    *(uint8_t*)0x20030ff9 = 0;
    *(uint8_t*)0x20030ffa = 0;
    *(uint8_t*)0x20030ffb = 0;
    *(uint8_t*)0x20030ffc = 0;
    *(uint8_t*)0x20030ffd = 0;
    *(uint8_t*)0x20030ffe = 0;
    *(uint8_t*)0x20030fff = 0;
    syscall(__NR_sendto, r[0], 0x20a34fff, 1, 0, 0x20030ff0, 0x10);
    break;
  case 2:
    memcpy((void*)0x20000000, "\xc6", 1);
    *(uint16_t*)0x20033ff0 = 2;
    *(uint16_t*)0x20033ff2 = htobe16(0);
    *(uint8_t*)0x20033ff4 = 0xac;
    *(uint8_t*)0x20033ff5 = 0x14;
    *(uint8_t*)0x20033ff6 = -1;
    *(uint8_t*)0x20033ff7 = 0xbb;
    *(uint8_t*)0x20033ff8 = 0;
    *(uint8_t*)0x20033ff9 = 0;
    *(uint8_t*)0x20033ffa = 0;
    *(uint8_t*)0x20033ffb = 0;
    *(uint8_t*)0x20033ffc = 0;
    *(uint8_t*)0x20033ffd = 0;
    *(uint8_t*)0x20033ffe = 0;
    *(uint8_t*)0x20033fff = 0;
    syscall(__NR_sendto, r[0], 0x20000000, 1, 0, 0x20033ff0, 0x10);
    break;
  case 3:
    syscall(__NR_shutdown, r[0], 1);
    break;
  case 4:
    *(uint32_t*)0x20000080 = 0;
    *(uint16_t*)0x20000084 = 0;
    *(uint16_t*)0x20000086 = 0xb0;
    *(uint64_t*)0x20000088 = 0;
    *(uint64_t*)0x20000090 = 0;
    *(uint32_t*)0x20000040 = 0x18;
    syscall(__NR_getsockopt, r[0], 0x84, 0x74, 0x20000080, 0x20000040);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  loop();
  return 0;
}