syzkaller-repros/linux/7ebea492de7521048355fc84210220e1038a7908.c

// possible deadlock in vfs_fallocate
// https://syzkaller.appspot.com/bug?id=7ebea492de7521048355fc84210220e1038a7908
// status:fixed
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <endian.h>
#include <stdint.h>
#include <string.h>
#include <sys/syscall.h>
#include <unistd.h>

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

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

uint64_t r[1] = {0xffffffffffffffff};
unsigned long long procid;
void execute_one()
{
  long res = 0;
  memcpy((void*)0x20b4508a, "/dev/ashmem", 12);
  res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20b4508a, 0, 0);
  if (res != -1)
    r[0] = res;
  syscall(__NR_ioctl, r[0], 0x40087703, 2);
  syscall(__NR_mmap, 0x206ff000, 0x3000, 0, 0x12, r[0], 0);
  syscall(__NR_ioctl, r[0], 0x770a, 0);
  memcpy((void*)0x20000080, "", 1);
  syscall(__NR_ioctl, r[0], 0x40087708, 0x20000080);
}

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;
}