*   Fixes a lack of validation in `tf.raw_ops.DataFormatVecPermute` and
    `tf.raw_ops.DataFormatDimMap` which can cause uninitialized memory access,
    read outside bounds of arrays, data corruption and segmentation faults
    ([CVE-2020-26267](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26267))
*   Fixes a crash caused by writing to read only memory region

  auto posix_file = static_cast<PosixFile*>(file->plugin_file);
  char* dst = buffer;
  int64_t read = 0;

  while (n > 0) {
    // Some platforms, notably macs, throw `EINVAL` if `pread` is asked to read
    // more than fits in a 32-bit integer.
    size_t requested_read_length;
    if (n > INT32_MAX)
      requested_read_length = INT32_MAX;
    else
      requested_read_length = n;