Duplicate SMB file_ids leading to Windows client cache poisoning

[Andrew Walker]

On Fri, Dec 10, 2021 at 11:39 AM Ralph Boehme <slow at samba.org> wrote:

> On 12/10/21 16:53, Andrew Walker wrote:
> > Do we know that there are still issues with MacOS when an inode is
> > reused during the lifetime of an SMB session? Do we have an easy way
> > to reproduce the MacOS issue? Perhaps if we can determine that the
> > issue only impacts legacy versions of MacOS we can go back to just
> > returning the inode and tell people with EOL MacOS to upgrade :)
>
> All I know is that "some applications" encompasses core stuff that uses
> the file-is a primary key to a key/value store that maps ids to
> filesystem objects. So reusing ids is (or was) a sure way to screw up
> Mac clients.
>

That's a good point, but if MacOS SMB client is faking up an inode number
based on a hash of the filename in the zero-id case, isn't it even more
likely to yield a collision at some point?