syzkaller-repros/linux/19bbd7c80d8ae27cbdedd7679e839e4b482957d2.c

// KASAN: use-after-free Read in __queue_work
// https://syzkaller.appspot.com/bug?id=19bbd7c80d8ae27cbdedd7679e839e4b482957d2
// status:open
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <endian.h>
#include <stdio.h>
#include <sys/syscall.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 <setjmp.h>
#include <signal.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string.h>
#include <sys/stat.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 __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* uctx)
{
  uintptr_t addr = (uintptr_t)info->si_addr;
  const uintptr_t prog_start = 1 << 20;
  const uintptr_t prog_end = 100 << 20;
  if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) &&
      (addr < prog_start || addr > prog_end)) {
    _longjmp(segv_env, 1);
  }
  doexit(sig);
}

static void install_segv_handler()
{
  struct sigaction sa;

  memset(&sa, 0, sizeof(sa));
  sa.sa_handler = SIG_IGN;
  syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8);
  syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8);

  memset(&sa, 0, sizeof(sa));
  sa.sa_sigaction = segv_handler;
  sa.sa_flags = SA_NODEFER | SA_SIGINFO;
  sigaction(SIGSEGV, &sa, NULL);
  sigaction(SIGBUS, &sa, NULL);
}

#define NONFAILING(...)                                                        \
  {                                                                            \
    __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    if (_setjmp(segv_env) == 0) {                                              \
      __VA_ARGS__;                                                             \
    }                                                                          \
    __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
  }

static void use_temporary_dir()
{
  char tmpdir_template[] = "./syzkaller.XXXXXX";
  char* tmpdir = mkdtemp(tmpdir_template);
  if (!tmpdir)
    fail("failed to mkdtemp");
  if (chmod(tmpdir, 0777))
    fail("failed to chmod");
  if (chdir(tmpdir))
    fail("failed to chdir");
}

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

void loop()
{
  while (1) {
    execute_one();
  }
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};
unsigned long long procid;
void execute_one()
{
  long res = 0;
  res = syscall(__NR_pipe2, 0x20000100, 0);
  if (res != -1) {
    NONFAILING(r[0] = *(uint32_t*)0x20000100);
    NONFAILING(r[1] = *(uint32_t*)0x20000104);
  }
  NONFAILING(*(uint32_t*)0x20000040 = 7);
  NONFAILING(*(uint8_t*)0x20000044 = 0x4d);
  NONFAILING(*(uint16_t*)0x20000045 = 0);
  syscall(__NR_write, r[1], 0x20000040, 7);
  NONFAILING(memcpy((void*)0x20000300, "./file0", 8));
  syscall(__NR_mkdir, 0x20000300, 0);
  NONFAILING(memcpy((void*)0x200000c0, "./file0", 8));
  NONFAILING(memcpy((void*)0x20000340, "9p", 3));
  NONFAILING(memcpy((void*)0x20000740, "trans=fd,", 9));
  NONFAILING(memcpy((void*)0x20000749, "rfdno", 5));
  NONFAILING(*(uint8_t*)0x2000074e = 0x3d);
  NONFAILING(sprintf((char*)0x2000074f, "0x%016llx", (long long)r[0]));
  NONFAILING(*(uint8_t*)0x20000761 = 0x2c);
  NONFAILING(memcpy((void*)0x20000762, "wfdno", 5));
  NONFAILING(*(uint8_t*)0x20000767 = 0x3d);
  NONFAILING(sprintf((char*)0x20000768, "0x%016llx", (long long)r[1]));
  NONFAILING(*(uint8_t*)0x2000077a = 0x2c);
  NONFAILING(memcpy((void*)0x2000077b, "version=9p2000.u", 16));
  NONFAILING(*(uint8_t*)0x2000078b = 0x2c);
  NONFAILING(*(uint8_t*)0x2000078c = 0);
  syscall(__NR_mount, 0, 0x200000c0, 0x20000340, 0, 0x20000740);
  NONFAILING(*(uint32_t*)0x20000480 = 0x2a);
  NONFAILING(*(uint8_t*)0x20000484 = 0x29);
  NONFAILING(*(uint16_t*)0x20000485 = 1);
  NONFAILING(*(uint32_t*)0x20000487 = 0);
  NONFAILING(*(uint8_t*)0x2000048b = 0xc8);
  NONFAILING(*(uint32_t*)0x2000048c = 0);
  NONFAILING(*(uint64_t*)0x20000490 = 0);
  NONFAILING(*(uint64_t*)0x20000498 = 0);
  NONFAILING(*(uint8_t*)0x200004a0 = 0);
  NONFAILING(*(uint16_t*)0x200004a1 = 7);
  NONFAILING(memcpy((void*)0x200004a3, "./file0", 7));
  syscall(__NR_write, r[1], 0x20000480, 0x2a);
  NONFAILING(*(uint32_t*)0x20000200 = 0xa0);
  NONFAILING(*(uint8_t*)0x20000204 = 0x19);
  NONFAILING(*(uint16_t*)0x20000205 = 1);
  NONFAILING(*(uint64_t*)0x20000207 = 0);
  NONFAILING(*(uint8_t*)0x2000020f = 0);
  NONFAILING(*(uint32_t*)0x20000210 = 0);
  NONFAILING(*(uint64_t*)0x20000214 = 0);
  NONFAILING(*(uint32_t*)0x2000021c = 0);
  NONFAILING(*(uint32_t*)0x20000220 = 0);
  NONFAILING(*(uint32_t*)0x20000224 = 0);
  NONFAILING(*(uint64_t*)0x20000228 = 0);
  NONFAILING(*(uint64_t*)0x20000230 = 0);
  NONFAILING(*(uint64_t*)0x20000238 = 0);
  NONFAILING(*(uint64_t*)0x20000240 = 0);
  NONFAILING(*(uint64_t*)0x20000248 = 0);
  NONFAILING(*(uint64_t*)0x20000250 = 0);
  NONFAILING(*(uint64_t*)0x20000258 = 0);
  NONFAILING(*(uint64_t*)0x20000260 = 0);
  NONFAILING(*(uint64_t*)0x20000268 = 0);
  NONFAILING(*(uint64_t*)0x20000270 = 0);
  NONFAILING(*(uint64_t*)0x20000278 = 0);
  NONFAILING(*(uint64_t*)0x20000280 = 0);
  NONFAILING(*(uint64_t*)0x20000288 = 0);
  NONFAILING(*(uint64_t*)0x20000290 = 0);
  NONFAILING(*(uint64_t*)0x20000298 = 0);
  syscall(__NR_write, r[1], 0x20000200, 0xa0);
  NONFAILING(*(uint32_t*)0x20000140 = 0x23);
  NONFAILING(*(uint8_t*)0x20000144 = 0x6f);
  NONFAILING(*(uint16_t*)0x20000145 = 1);
  NONFAILING(*(uint16_t*)0x20000147 = 2);
  NONFAILING(*(uint8_t*)0x20000149 = 0);
  NONFAILING(*(uint32_t*)0x2000014a = 0);
  NONFAILING(*(uint64_t*)0x2000014e = 0);
  NONFAILING(*(uint8_t*)0x20000156 = 0);
  NONFAILING(*(uint32_t*)0x20000157 = 0);
  NONFAILING(*(uint64_t*)0x2000015b = 0);
  syscall(__NR_write, r[1], 0x20000140, 0x23);
  NONFAILING(memcpy((void*)0x200003c0,
                    "\xfa\x00\x00\x00\x29\x01\x00\x00\x00\x00\x00", 11));
  syscall(__NR_write, r[1], 0x200003c0, 0xb);
  NONFAILING(*(uint32_t*)0x20000600 = 0xb);
  NONFAILING(*(uint8_t*)0x20000604 = 0x29);
  NONFAILING(*(uint16_t*)0x20000605 = 1);
  NONFAILING(*(uint32_t*)0x20000607 = 0);
  syscall(__NR_write, r[1], 0x20000600, 0xb);
  NONFAILING(memcpy((void*)0x20000000, "./file0", 8));
  NONFAILING(memcpy((void*)0x20000900, "9p", 3));
  NONFAILING(memcpy((void*)0x20000840, "trans=fd,", 9));
  NONFAILING(memcpy((void*)0x20000849, "rfdno", 5));
  NONFAILING(*(uint8_t*)0x2000084e = 0x3d);
  NONFAILING(sprintf((char*)0x2000084f, "0x%016llx", (long long)r[0]));
  NONFAILING(*(uint8_t*)0x20000861 = 0x2c);
  NONFAILING(memcpy((void*)0x20000862, "wfdno", 5));
  NONFAILING(*(uint8_t*)0x20000867 = 0x3d);
  NONFAILING(sprintf((char*)0x20000868, "0x%016llx", (long long)r[1]));
  NONFAILING(*(uint8_t*)0x2000087a = 0x2c);
  NONFAILING(memcpy((void*)0x2000087b, "access", 6));
  NONFAILING(*(uint8_t*)0x20000881 = 0x3d);
  NONFAILING(sprintf((char*)0x20000882, "%020llu", (long long)0));
  NONFAILING(*(uint8_t*)0x20000896 = 0x2c);
  NONFAILING(*(uint8_t*)0x20000897 = 0);
  syscall(__NR_mount, 0, 0x20000000, 0x20000900, 0, 0x20000840);
  NONFAILING(memcpy((void*)0x20000540, "./file0", 8));
  NONFAILING(memcpy((void*)0x200005c0, "./file0", 8));
  syscall(__NR_symlinkat, 0x20000540, -1, 0x200005c0);
  NONFAILING(memcpy((void*)0x20000080, "./file0", 8));
  syscall(__NR_umount2, 0x20000080, 1);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  char* cwd = get_current_dir_name();
  for (procid = 0; procid < 8; procid++) {
    if (fork() == 0) {
      install_segv_handler();
      for (;;) {
        if (chdir(cwd))
          fail("failed to chdir");
        use_temporary_dir();
        loop();
      }
    }
  }
  sleep(1000000);
  return 0;
}