syzkaller-repros/linux/5f31b30406d84a86d4b7a42c103f6eda07eed137.c

// KASAN: null-ptr-deref Read in refcount_sub_and_test_checked
// https://syzkaller.appspot.com/bug?id=5f31b30406d84a86d4b7a42c103f6eda07eed137
// status:fixed
// 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>

static long syz_open_dev(long a0, long a1, long a2)
{
  if (a0 == 0xc || a0 == 0xb) {
    char buf[128];
    sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1,
            (uint8_t)a2);
    return open(buf, O_RDWR, 0);
  } else {
    char buf[1024];
    char* hash;
    strncpy(buf, (char*)a0, sizeof(buf) - 1);
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(a1 % 10);
      a1 /= 10;
    }
    return open(buf, a2, 0);
  }
}

uint64_t r[1] = {0xffffffffffffffff};

int main(void)
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  long res = 0;
  memcpy((void*)0x20000000, "/dev/video#", 12);
  res = syz_open_dev(0x20000000, 0xe15, 0);
  if (res != -1)
    r[0] = res;
  *(uint32_t*)0x20000100 = 5;
  *(uint32_t*)0x20000104 = 2;
  *(uint32_t*)0x20000108 = 1;
  *(uint32_t*)0x2000010c = 0;
  *(uint32_t*)0x20000110 = 0;
  syscall(__NR_ioctl, r[0], 0xc0145608, 0x20000100);
  *(uint32_t*)0x20000140 = 0x5f56e7c2;
  *(uint32_t*)0x20000144 = 0xffff;
  *(uint32_t*)0x20000148 = 2;
  *(uint32_t*)0x20000150 = 2;
  *(uint16_t*)0x20000158 = 4;
  *(uint16_t*)0x2000015a = 0xfff;
  *(uint16_t*)0x2000015c = 0x400;
  *(uint16_t*)0x2000015e = 0x81;
  *(uint16_t*)0x20000160 = 5;
  *(uint16_t*)0x20000162 = 5;
  *(uint16_t*)0x20000164 = 0;
  *(uint16_t*)0x20000166 = 5;
  *(uint16_t*)0x20000168 = 0xfff8;
  *(uint16_t*)0x2000016a = 7;
  *(uint16_t*)0x2000016c = 0x40;
  *(uint16_t*)0x2000016e = 0x1f;
  *(uint16_t*)0x20000170 = 8;
  *(uint16_t*)0x20000172 = 1;
  *(uint16_t*)0x20000174 = 0xead8;
  *(uint16_t*)0x20000176 = 6;
  *(uint16_t*)0x20000178 = 9;
  *(uint16_t*)0x2000017a = 3;
  *(uint16_t*)0x2000017c = 0x7b;
  *(uint16_t*)0x2000017e = 5;
  *(uint16_t*)0x20000180 = 7;
  *(uint16_t*)0x20000182 = 0x645;
  *(uint16_t*)0x20000184 = 0x409;
  *(uint16_t*)0x20000186 = 3;
  *(uint16_t*)0x20000188 = 0x100;
  *(uint16_t*)0x2000018a = -1;
  *(uint16_t*)0x2000018c = 0xfff;
  *(uint16_t*)0x2000018e = 9;
  *(uint16_t*)0x20000190 = 0;
  *(uint16_t*)0x20000192 = 0x97fc;
  *(uint16_t*)0x20000194 = 0x7ff;
  *(uint16_t*)0x20000196 = 5;
  *(uint16_t*)0x20000198 = 5;
  *(uint16_t*)0x2000019a = 6;
  *(uint16_t*)0x2000019c = 0x100;
  *(uint16_t*)0x2000019e = 0xf413;
  *(uint16_t*)0x200001a0 = 3;
  *(uint16_t*)0x200001a2 = 0x1aef;
  *(uint16_t*)0x200001a4 = -1;
  *(uint16_t*)0x200001a6 = 8;
  *(uint16_t*)0x200001a8 = 0x80;
  *(uint16_t*)0x200001aa = 1;
  *(uint16_t*)0x200001ac = 7;
  *(uint16_t*)0x200001ae = 0xf870;
  *(uint16_t*)0x200001b0 = 7;
  *(uint16_t*)0x200001b2 = 4;
  *(uint16_t*)0x200001b4 = 1;
  *(uint16_t*)0x200001b6 = 6;
  *(uint16_t*)0x200001b8 = 0xd4a;
  *(uint32_t*)0x200001bc = 0x34;
  *(uint32_t*)0x200001c0 = 0;
  *(uint32_t*)0x200001c4 = 0;
  *(uint32_t*)0x20000220 = 0;
  *(uint32_t*)0x20000224 = 0;
  *(uint32_t*)0x20000228 = 0;
  *(uint32_t*)0x2000022c = 0;
  *(uint32_t*)0x20000230 = 0;
  *(uint32_t*)0x20000234 = 0;
  *(uint32_t*)0x20000238 = 0;
  *(uint32_t*)0x2000023c = 0;
  syscall(__NR_ioctl, r[0], 0xc100565c, 0x20000140);
  return 0;
}