Determining owner of a (fuse) mountpoint?

Determining owner of a (fuse) mountpoint?

[Nikolaus Rath]

Hello,

Given a (FUSE) mountpoint (potentially mounted without -o allow_root),
is there a way for root to determine its "owner" (i.e. the user who has
started the FUSE process and invoked fusermount) that does not depend on
cooperation of the user/filesystem?

Best,
-Nikolaus

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Re: Determining owner of a (fuse) mountpoint?

[Aleksa Sarai]

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On 2020-05-15, Nikolaus Rath <Nikolaus@rath.org> wrote:
> Given a (FUSE) mountpoint (potentially mounted without -o allow_root),
> is there a way for root to determine its "owner" (i.e. the user who has
> started the FUSE process and invoked fusermount) that does not depend on
> cooperation of the user/filesystem?

The mount options of a FUSE mount contain the entries "user_id=N" and
"group_id=M" which correspond to the "mount owner" and those entries are
filled by fusermount. Is that not sufficient?

-- 
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
<https://www.cyphar.com/>

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Re: [fuse-devel] Determining owner of a (fuse) mountpoint?

[Nikolaus Rath]

On Sun, 17 May 2020, at 09:09, Aleksa Sarai wrote:
> On 2020-05-15, Nikolaus Rath <Nikolaus@rath.org> wrote:
> > Given a (FUSE) mountpoint (potentially mounted without -o allow_root),
> > is there a way for root to determine its "owner" (i.e. the user who has
> > started the FUSE process and invoked fusermount) that does not depend on
> > cooperation of the user/filesystem?
> 
> The mount options of a FUSE mount contain the entries "user_id=N" and
> "group_id=M" which correspond to the "mount owner" and those entries are
> filled by fusermount. Is that not sufficient?

I think it is sufficient, I just never noticed it. Thanks!

Best,
-Nikolaus

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 »Time flies like an arrow, fruit flies like a Banana.«