fs/ntfs : use-after-free Read in ntfs_attr_find

[Manas Ghandat]

Hi,

I was looking at this syzbot issue : 
https://syzkaller.appspot.com/bug?extid=ef50f8eb00b54feb7ba2

While debugging I found that when we are traversing through the 
attribute list, there is case when the next attribute is null (most 
likely we are traversing out of the list) and thus there is this error. 
I was wondering if we could add a size field to this attribute list. 
This would fix this issue. Currently we are just parsing to the next 
attribute using the length field.