syzkaller-repros/linux/6c1b04a3fa68d252d38ef6aa79993865d4124a88.c

// INFO: rcu detected stall (2)
// https://syzkaller.appspot.com/bug?id=6c1b04a3fa68d252d38ef6aa79993865d4124a88
// status:fixed
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <fcntl.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <unistd.h>

#include <stdint.h>
#include <string.h>

#define BITMASK_LEN(type, bf_len) (type)((1ull << (bf_len)) - 1)

#define BITMASK_LEN_OFF(type, bf_off, bf_len)                          \
  (type)(BITMASK_LEN(type, (bf_len)) << (bf_off))

#define STORE_BY_BITMASK(type, addr, val, bf_off, bf_len)              \
  if ((bf_off) == 0 && (bf_len) == 0) {                                \
    *(type*)(addr) = (type)(val);                                      \
  } else {                                                             \
    type new_val = *(type*)(addr);                                     \
    new_val &= ~BITMASK_LEN_OFF(type, (bf_off), (bf_len));             \
    new_val |= ((type)(val)&BITMASK_LEN(type, (bf_len))) << (bf_off);  \
    *(type*)(addr) = new_val;                                          \
  }

struct csum_inet {
  uint32_t acc;
};

static void csum_inet_init(struct csum_inet* csum)
{
  csum->acc = 0;
}

static void csum_inet_update(struct csum_inet* csum,
                             const uint8_t* data, size_t length)
{
  if (length == 0)
    return;

  size_t i;
  for (i = 0; i < length - 1; i += 2)
    csum->acc += *(uint16_t*)&data[i];

  if (length & 1)
    csum->acc += (uint16_t)data[length - 1];

  while (csum->acc > 0xffff)
    csum->acc = (csum->acc & 0xffff) + (csum->acc >> 16);
}

static uint16_t csum_inet_digest(struct csum_inet* csum)
{
  return ~csum->acc;
}

static uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t 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));
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(a1 % 10);
      a1 /= 10;
    }
    return open(buf, a2, 0);
  }
}

long r[70];
void loop()
{
  memset(r, -1, sizeof(r));
  r[0] = syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul,
                 0xfffffffffffffffful, 0x0ul);
  r[1] = syscall(__NR_socket, 0x2ul, 0x1ul, 0x0ul);
  memcpy((void*)0x2051fff3,
         "\x2f\x64\x65\x76\x2f\x6e\x65\x74\x2f\x74\x75\x6e\x00", 13);
  r[3] = syz_open_dev(0x2051fff3ul, 0x0ul, 0xaul);
  r[4] = syscall(__NR_fcntl, r[3], 0x0ul, r[3]);
  memcpy((void*)0x20a5afd8,
         "\x67\x72\x65\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
         "\x00",
         16);
  memcpy((void*)0x20a5afe8,
         "\x4f\x54\x00\x0c\xc0\xa1\xed\x4f\x3a\x0a\x1f\xdc\x22\x20\x73"
         "\xb5",
         16);
  r[7] = syscall(__NR_ioctl, r[3], 0x400454caul, 0x20a5afd8ul);
  memcpy((void*)0x2062ffe0,
         "\x67\x72\x65\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
         "\x00",
         16);
  *(uint16_t*)0x2062fff0 = (uint16_t)0x301;
  r[10] = syscall(__NR_ioctl, r[1], 0x8914ul, 0x2062ffe0ul);
  *(uint32_t*)0x20e9bffc = (uint32_t)0xfffffffffffffffc;
  r[12] = syscall(__NR_ioctl, r[3], 0x400454d4ul, 0x20e9bffcul);
  *(uint8_t*)0x20101000 = (uint8_t)0x0;
  *(uint8_t*)0x20101001 = (uint8_t)0x0;
  *(uint16_t*)0x20101002 = (uint16_t)0x0;
  *(uint16_t*)0x20101004 = (uint16_t)0x0;
  *(uint16_t*)0x20101006 = (uint16_t)0x0;
  *(uint16_t*)0x20101008 = (uint16_t)0x0;
  STORE_BY_BITMASK(uint8_t, 0x2010100a, 0x0, 0, 4);
  STORE_BY_BITMASK(uint8_t, 0x2010100a, 0x6, 4, 4);
  memcpy((void*)0x2010100b, "\x85\xb7\xe3", 3);
  *(uint16_t*)0x2010100e = (uint16_t)0x1400;
  *(uint8_t*)0x20101010 = (uint8_t)0x6;
  *(uint8_t*)0x20101011 = (uint8_t)0x0;
  *(uint8_t*)0x20101012 = (uint8_t)0xfe;
  *(uint8_t*)0x20101013 = (uint8_t)0x80;
  *(uint8_t*)0x20101014 = (uint8_t)0x0;
  *(uint8_t*)0x20101015 = (uint8_t)0x0;
  *(uint8_t*)0x20101016 = (uint8_t)0x0;
  *(uint8_t*)0x20101017 = (uint8_t)0x0;
  *(uint8_t*)0x20101018 = (uint8_t)0x0;
  *(uint8_t*)0x20101019 = (uint8_t)0x0;
  *(uint8_t*)0x2010101a = (uint8_t)0x0;
  *(uint8_t*)0x2010101b = (uint8_t)0x0;
  *(uint8_t*)0x2010101c = (uint8_t)0x0;
  *(uint8_t*)0x2010101d = (uint8_t)0x0;
  *(uint8_t*)0x2010101e = (uint8_t)0x0;
  *(uint8_t*)0x2010101f = (uint8_t)0x0;
  *(uint8_t*)0x20101020 = (uint8_t)0x0;
  *(uint8_t*)0x20101021 = (uint8_t)0xbb;
  *(uint8_t*)0x20101022 = (uint8_t)0xfe;
  *(uint8_t*)0x20101023 = (uint8_t)0x80;
  *(uint8_t*)0x20101024 = (uint8_t)0x0;
  *(uint8_t*)0x20101025 = (uint8_t)0x0;
  *(uint8_t*)0x20101026 = (uint8_t)0x0;
  *(uint8_t*)0x20101027 = (uint8_t)0x0;
  *(uint8_t*)0x20101028 = (uint8_t)0x0;
  *(uint8_t*)0x20101029 = (uint8_t)0x0;
  *(uint8_t*)0x2010102a = (uint8_t)0x0;
  *(uint8_t*)0x2010102b = (uint8_t)0x0;
  *(uint8_t*)0x2010102c = (uint8_t)0x0;
  *(uint8_t*)0x2010102d = (uint8_t)0x0;
  *(uint8_t*)0x2010102e = (uint8_t)0x0;
  *(uint8_t*)0x2010102f = (uint8_t)0x0;
  *(uint8_t*)0x20101030 = (uint8_t)0x0;
  *(uint8_t*)0x20101031 = (uint8_t)0xbb;
  *(uint16_t*)0x20101032 = (uint16_t)0x204e;
  *(uint16_t*)0x20101034 = (uint16_t)0x204e;
  *(uint32_t*)0x20101036 = (uint32_t)0x42424242;
  *(uint32_t*)0x2010103a = (uint32_t)0x42424242;
  STORE_BY_BITMASK(uint8_t, 0x2010103e, 0x0, 0, 1);
  STORE_BY_BITMASK(uint8_t, 0x2010103e, 0x0, 1, 3);
  STORE_BY_BITMASK(uint8_t, 0x2010103e, 0x5, 4, 4);
  *(uint8_t*)0x2010103f = (uint8_t)0x0;
  *(uint16_t*)0x20101040 = (uint16_t)0x0;
  *(uint16_t*)0x20101042 = (uint16_t)0x0;
  *(uint16_t*)0x20101044 = (uint16_t)0x0;
  struct csum_inet csum_68;
  csum_inet_init(&csum_68);
  csum_inet_update(&csum_68, (const uint8_t*)0x20101012, 16);
  csum_inet_update(&csum_68, (const uint8_t*)0x20101022, 16);
  uint32_t csum_68_chunk_2 = 0x14000000;
  csum_inet_update(&csum_68, (const uint8_t*)&csum_68_chunk_2, 4);
  uint32_t csum_68_chunk_3 = 0x6000000;
  csum_inet_update(&csum_68, (const uint8_t*)&csum_68_chunk_3, 4);
  csum_inet_update(&csum_68, (const uint8_t*)0x20101032, 20);
  *(uint16_t*)0x20101042 = csum_inet_digest(&csum_68);
  r[69] = syscall(__NR_write, r[4], 0x20101000ul, 0x46ul);
}

int main()
{
  loop();
  return 0;
}