ntfs: check for valid standard information attribute

Mounting a corrupted filesystem with NTFS resulted in a kernel crash.

We should check for valid STANDARD_INFORMATION attribute offset and length
before trying to access it

Link: https://lkml.kernel.org/r/20210217155930.1506815-1-rkovhaev@gmail.com
Link: https://syzkaller.appspot.com/bug?extid=c584225dabdea2f71969


Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com>
Reported-by:  <syzbot+c584225dabdea2f71969@syzkaller.appspotmail.com>
Tested-by:  <syzbot+c584225dabdea2f71969@syzkaller.appspotmail.com>
Acked-by: Anton Altaparmakov <anton@tuxera.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>