The attached file produces the following stacktrace when opened via `tarfile.open` and iterated with `TarFile.getmembers`, on Python 3.7.5rc1:

```
$ cat tarrepro.py 
import tarfile
import sys

with tarfile.open(sys.argv[1]) as t:
  for member in t.getmembers():
    pass
```

```
$ python3 tarrepro.py crash-462a00f845e737bff6df2fe6467fc7cdd4c39cd8e27ef1d3011ec68a9808ca8e
Traceback (most recent call last):
  File "tarrepro.py", line 5, in <module>
    for member in t.getmembers():
  File "/usr/lib/python3.7/tarfile.py", line 1763, in getmembers
    self._load()        # all members, we first have to
  File "/usr/lib/python3.7/tarfile.py", line 2350, in _load
    tarinfo = self.next()
  File "/usr/lib/python3.7/tarfile.py", line 2281, in next
    self.fileobj.seek(self.offset - 1)
  File "/usr/lib/python3.7/gzip.py", line 368, in seek
    return self._buffer.seek(offset, whence)
  File "/usr/lib/python3.7/_compression.py", line 143, in seek
    data = self.read(min(io.DEFAULT_BUFFER_SIZE, offset))
  File "/usr/lib/python3.7/gzip.py", line 454, in read
    self._read_eof()
  File "/usr/lib/python3.7/gzip.py", line 501, in _read_eof
    hex(self._crc)))
OSError: CRC check failed 0x21e25017 != 0x7c839e8b
```

The OSError exception isn't documented as a possible exception when using TarFile.getmembers ( https://docs.python.org/3/library/tarfile.html ).

Following Issue6584 it raises BadGzipFile.