Re: Grrrr fusermount.

[Andy Lutomirski]

On Wed, Oct 9, 2013 at 12:12 PM, Eric W. Biederman
<ebiederm@xxxxxxxxxxxx> wrote:
> ebiederm@xxxxxxxxxxxx (Eric W. Biederman) writes:
>
>> But I will go through and read the old fusermount code before I get too
>> much farther just so I understand what I am potentially breaking.
>
> Grr.
>
> So I have just read the fusermount umount code and the hack that it uses
> before there was UMOUNT_NOFOLLOW support in the vm.
>
> If I walk this path of lazy unmounts and detaching directories, anyone
> with a new kernel and an old copy of fusermount and a nfs mounted home
> directory will be able to exploit the fusermount umount symlink race.
>
> Unless we can declare that old fusermount binaries are buggy beyond
> supporting this patchset as it exists is dead.

What's the hack that it does?

--Andy
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