syzkaller-repros/linux/b5d60ae88477b73357ff2221de8153a214956344.c

// KASAN: use-after-free Read in bpf_tcp_close
// https://syzkaller.appspot.com/bug?id=b5d60ae88477b73357ff2221de8153a214956344
// status:fixed
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <endian.h>
#include <errno.h>
#include <linux/futex.h>
#include <pthread.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/prctl.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

__attribute__((noreturn)) static void doexit(int status)
{
  volatile unsigned i;
  syscall(__NR_exit_group, status);
  for (i = 0;; i++) {
  }
}
#include <errno.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>

const int kFailStatus = 67;
const int kRetryStatus = 69;

static void fail(const char* msg, ...)
{
  int e = errno;
  va_list args;
  va_start(args, msg);
  vfprintf(stderr, msg, args);
  va_end(args);
  fprintf(stderr, " (errno %d)\n", e);
  doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus);
}

static uint64_t current_time_ms()
{
  struct timespec ts;

  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    fail("clock_gettime failed");
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

static void execute_one();
extern unsigned long long procid;

static void loop()
{
  int iter;
  for (iter = 0;; iter++) {
    int pid = fork();
    if (pid < 0)
      fail("clone failed");
    if (pid == 0) {
      prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
      setpgrp();
      execute_one();
      doexit(0);
    }

    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      int res = waitpid(-1, &status, __WALL | WNOHANG);
      if (res == pid) {
        break;
      }
      usleep(1000);
      if (current_time_ms() - start < 3 * 1000)
        continue;
      kill(-pid, SIGKILL);
      kill(pid, SIGKILL);
      while (waitpid(-1, &status, __WALL) != pid) {
      }
      break;
    }
  }
}

struct thread_t {
  int created, running, call;
  pthread_t th;
};

static struct thread_t threads[16];
static void execute_call(int call);
static int running;
static int collide;

static void* thr(void* arg)
{
  struct thread_t* th = (struct thread_t*)arg;
  for (;;) {
    while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE))
      syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE);
    syscall(SYS_futex, &th->running, FUTEX_WAKE);
  }
  return 0;
}

static void execute(int num_calls)
{
  int call, thread;
  running = 0;
  for (call = 0; call < num_calls; call++) {
    for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        pthread_attr_t attr;
        pthread_attr_init(&attr);
        pthread_attr_setstacksize(&attr, 128 << 10);
        pthread_create(&th->th, &attr, thr, th);
      }
      if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) {
        th->call = call;
        __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
        __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE);
        syscall(SYS_futex, &th->running, FUTEX_WAKE);
        if (collide && call % 2)
          break;
        struct timespec ts;
        ts.tv_sec = 0;
        ts.tv_nsec = 20 * 1000 * 1000;
        syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts);
        if (running)
          usleep((call == num_calls - 1) ? 10000 : 1000);
        break;
      }
    }
  }
}

#ifndef __NR_bpf
#define __NR_bpf 321
#endif

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};
unsigned long long procid;
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    res = syscall(__NR_socketpair, 0xfffffffffffffffe, 3, 0xf9, 0x20000140);
    if (res != -1)
      r[0] = *(uint32_t*)0x20000144;
    break;
  case 1:
    syscall(__NR_socket, 0xa, 1, 0);
    break;
  case 2:
    *(uint32_t*)0x20000100 = r[0];
    *(uint64_t*)0x20000108 = 0x20000000;
    *(uint64_t*)0x20000110 = 0x20000040;
    syscall(__NR_bpf, 1, 0x20000100, 0x18);
    break;
  case 3:
    *(uint32_t*)0x20000280 = 0x12;
    *(uint32_t*)0x20000284 = 0;
    *(uint32_t*)0x20000288 = 4;
    *(uint32_t*)0x2000028c = 7;
    *(uint32_t*)0x20000290 = 0;
    *(uint32_t*)0x20000294 = 1;
    *(uint32_t*)0x20000298 = 0;
    *(uint8_t*)0x2000029c = 0;
    *(uint8_t*)0x2000029d = 0;
    *(uint8_t*)0x2000029e = 0;
    *(uint8_t*)0x2000029f = 0;
    *(uint8_t*)0x200002a0 = 0;
    *(uint8_t*)0x200002a1 = 0;
    *(uint8_t*)0x200002a2 = 0;
    *(uint8_t*)0x200002a3 = 0;
    *(uint8_t*)0x200002a4 = 0;
    *(uint8_t*)0x200002a5 = 0;
    *(uint8_t*)0x200002a6 = 0;
    *(uint8_t*)0x200002a7 = 0;
    *(uint8_t*)0x200002a8 = 0;
    *(uint8_t*)0x200002a9 = 0;
    *(uint8_t*)0x200002aa = 0;
    *(uint8_t*)0x200002ab = 0;
    res = syscall(__NR_bpf, 0, 0x20000280, 0x2c);
    if (res != -1)
      r[1] = res;
    break;
  case 4:
    *(uint32_t*)0x20000180 = r[1];
    *(uint64_t*)0x20000188 = 0x20000000;
    *(uint64_t*)0x20000190 = 0x20000140;
    *(uint64_t*)0x20000198 = 0;
    syscall(__NR_bpf, 2, 0x20000180, 0x20);
    break;
  case 5:
    *(uint32_t*)0x20000200 = r[0];
    *(uint32_t*)0x20000204 = 0x28;
    *(uint64_t*)0x20000208 = 0x200001c0;
    syscall(__NR_bpf, 0xf, 0x20000200, 0x10);
    break;
  case 6:
    *(uint32_t*)0x20000180 = r[1];
    *(uint64_t*)0x20000188 = 0x20000080;
    *(uint64_t*)0x20000190 = 0x20000140;
    *(uint64_t*)0x20000198 = 0;
    syscall(__NR_bpf, 2, 0x20000180, 0x20);
    break;
  }
}

void execute_one()
{
  execute(7);
  collide = 1;
  execute(7);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  for (procid = 0; procid < 8; procid++) {
    if (fork() == 0) {
      for (;;) {
        loop();
      }
    }
  }
  sleep(1000000);
  return 0;
}