Re: nfsd vurlerability submit

Chuck Lever
2021-01-14T18:36:30Z

> On Jan 14, 2021, at 1:29 PM, Linus Torvalds <torvalds@linuxfoundation.org> wrote:
>
> On Thu, Jan 14, 2021 at 10:08 AM bfields@fieldses.org
> <bfields@fieldses.org> wrote:
>>
>> I dug around a bit and couldn't find the idea of using filehandle
>> guessing plus mountd's following of symlinks to get access to other
>> filesystems. That's kind of interesting.
>
> [ Other people removed from cc, this is just a question about nfsd cleanliness ]
>
> I missed if Trond's suggestion to at least fix up ".." to have the
> same filehandle as "." for the top export directory was done.

If I understand your question correctly... there is a commit in
linux-next that simply doesn't return any filehandle for ".."
in the root directory.

https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/commit/?h=for-next&id=51b2ee7d006a736a9126e8111d1f24e4fd0afaa6

I intend to send you a PR after a few more days of soak time,
unless you'd like me to send it now.

--
Chuck Lever