Ownership and permissions on /run/user/601/doc ???

John Conover

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Jun 1, 2021, 11:30:05 AM6/1/21

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Peculiar ownership and permissions on /run/user/601/doc:

d????????? ? ? ? ? ? doc/

and it can not be changed as root.

Logging out, then in, same thing.

Any help on fixing it would be greatly appreciated.

Thanks,

John

--

John Conover, con...@rahul.net, http://www.johncon.com/

Markus Schönhaber

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Jun 1, 2021, 12:10:04 PM6/1/21

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01.06.21, 17:28 +0200, John Conover:

> Peculiar ownership and permissions on /run/user/601/doc:
>
> d????????? ? ? ? ? ? doc/
>
> and it can not be changed as root.
>
> Logging out, then in, same thing.
>
> Any help on fixing it would be greatly appreciated.

There's likely nothing to fix. This is how the mount point of some FUSE
filesystems look when viewed from someone else as the owner.
In your case, try to look at it as the user with id 601.

BTW: findmnt will show what is mounted where.

--
Regards
mks

John Conover

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Jun 1, 2021, 12:30:05 PM6/1/21

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=?UTF-8?Q?Markus_Sch=c3=b6nhaber?= writes:
> 01.06.21, 17:28 +0200, John Conover:
>
> > Peculiar ownership and permissions on /run/user/601/doc:
> >
> > d????????? ? ? ? ? ? doc/
> >
> > and it can not be changed as root.
> >
> > Logging out, then in, same thing.
> >
> > Any help on fixing it would be greatly appreciated.
>
> There's likely nothing to fix. This is how the mount point of some FUSE
> filesystems look when viewed from someone else as the owner.
> In your case, try to look at it as the user with id 601.
>

This issue was found this AM from updatedb(1), (cron job.) All my
machines have changed the same way after after yesterday's apt-get
update, (xdg maybe?)

On another machine, (they are all the same, as close as I can make
them,) after booting and logging in, ls -al /run/user/601, the doc/
directory:

dr-x------ 2 theuser users 0 Dec 31 1969 doc/

Then running updatedb, and ls -al /run/user/601:

d????????? ? ? ? ? ? doc/

findmntl(8):

/run/user/601/doc /dev/fuse fuse rw,nosuid,nodev,relatim

Thomas Schmitt

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Jun 1, 2021, 12:30:05 PM6/1/21

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Hi,

John Conover wrote:
> Peculiar ownership and permissions on /run/user/601/doc:
> d????????? ? ? ? ? ? doc/

Are you already the user with id 601 ?
If not: Does it work better if you become that user ?

The web knows about problems of program df with /run/user/*/doc
https://bugs.launchpad.net/ubuntu/+source/xdg-desktop-portal/+bug/1905623

My understanding is that a flatpack component named xdg-document-portal
creates such /run/user/*/doc directories as fuse mountpoints, which only
the owner of the mounted filesystem can inspect.

https://askubuntu.com/questions/1227667/df-command-throws-error-on-run-user-1000-doc-folder
has the proposal to get rid of xdg-desktop-portal by executing:

systemctl --user stop xdg-document-portal.service

---------------------------------------------------------------------------

Ubuntu's proposal for a solution for df is to add "devtmpfs", "fuse.portal",
and "squashfs" to a list of dummy filesystems in gnulib.
https://bugs.launchpad.net/ubuntu/+source/xdg-desktop-portal/+bug/1905623/comments/14
where
https://launchpadlibrarian.net/510003931/coreutils_8.32-4ubuntu1_8.32-4ubuntu2.diff.gz
would hopefully apply to our
https://sources.debian.org/src/gnulib/20210102~ebaa53c-1/lib/mountlist.c/?hl=166#L166

This does not fix the acessability of the directory, but only hides it
from df's enumeration of mount points.
So i'd say that Ubuntu regards the problem as annoying but not as indication
of a serious filesystem problem.

Have a nice day :)

Thomas

John Conover

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Jun 1, 2021, 12:40:05 PM6/1/21

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Thomas Schmitt writes:
> Hi,
>
> John Conover wrote:
> > Peculiar ownership and permissions on /run/user/601/doc:
> > d????????? ? ? ? ? ? doc/
>
> Are you already the user with id 601 ?
> If not: Does it work better if you become that user ?
>

As the user, or as root.

Thomas Schmitt

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Jun 1, 2021, 12:50:04 PM6/1/21

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Hi,

i wrote:
> > Are you already the user with id 601 ?
> > If not: Does it work better if you become that user ?

John Conover wrote:
> As the user, or as root.

Then it could be owned by another user id.
(Hard to guess while stat(2) fails even for the boss.)

But you could at least verify that you suffer from the known problem
with xdg-desktop-portal by stopping it by the systemctl command.
Then look whether the .../doc directory vanished or changed its
accessability.

John Conover

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Jun 1, 2021, 1:20:04 PM6/1/21

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Thanks, Thomas.

findmnt:

/run/user/601/doc /dev/fuse fuse rw,nosuid,nodev,relatim

ls -al /dev/fuse:

crw-rw-rw- 1 root root 10, 229 Jun 1 08:16 /dev/fuse

I have no idea what kind of mount(1) command was used to make
/run/user/601/doc. It does respond to umount(8), and ls -al
/run/user/601/doc:

drwx------ 2 theuser users 40 Jun 1 10:01 doc/

Logging out, and in, ls -al /run/user/601/doc:

d????????? ? ? ? ? ? doc/

So, its in the mount command at login, (or whatever was used for the
fuse system-it could be a different type of file system that find(1),
updatedb(1), etc., stumbles into,) at login.

John Conover

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Jun 1, 2021, 2:40:04 PM6/1/21

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John Conover writes:

> Thomas Schmitt writes:
> >
> > > > Are you already the user with id 601 ?
> > > > If not: Does it work better if you become that user ?
> >

On Debian 10 Buster, both fvwm and xfce.

Odd, root can not access the /run/user/601/ directory, but the user
can:

ls -al /run/user/601/ | egrep doc/

dr-x------ 2 theuser users 0 Dec 31 1969 doc/

su
ls -al /run/user/601/ | egrep doc/
/bin/ls: cannot access '/run/user/601/doc': Permission denied

d????????? ? ? ? ? ? doc/

exit

ls -al /run/user/601/ | egrep doc/

dr-x------ 2 theuser users 0 Dec 31 1969 doc/

which accounts for the failure of updatedb(1), (running out of cron
with UID 0.) Might effect find(1), too.

Odd timestamp on /run/user/601/doc, with "Permission denied" to ls -al
/run/user/601 as root.

Thomas Schmitt

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Jun 1, 2021, 3:10:04 PM6/1/21

to

Hi,

John Conover wrote:
> Odd, root can not access the /run/user/601/ directory, but the user
> can

This is said to be a fuse filesystem feature. See e.g.
https://superuser.com/questions/169977/mount-point-permission-denied

> dr-x------ 2 theuser users 0 Dec 31 1969 doc/

> Odd timestamp on /run/user/601/doc,

Probably (time_t) 0 = 1 Jan 1970 UTC. In your timezone -0700 it's
new year's eve 1969, 5 pm.
The --time-style option of ls should be able show the integer time value.
With:

ls -l --time-style=+%s

i'd expect something like:
dr-x------ 2 theuser users 0 0 doc/

Thomas Schmitt

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Jun 1, 2021, 4:50:05 PM6/1/21

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Hi,

virtual private message to John Conover:

I answered to your private mail of 1 Jun 2021 12:51:26 -0700.
But my mail provider's server reports that your mail provider's server
refuses to take it:

From: GMX Mailer Daemon <mailer...@gmx.net>
...
con...@rahul.net:
SMTP error from remote server for TEXT command, host: aqua-new.rahul.net
(152.44.41.158) reason: 554 5.7.1 Spam message rejected
...
--- The header of the original message is following. ---
...
Date: Tue, 01 Jun 2021 22:31:02 +0200
From: "Thomas Schmitt" <scdb...@gmx.net>
Message-Id: <663933683...@scdbackup.webframe.org>

Please give me a note when i can make a new try.

(I tried again and got no rejection notice yet:
Date: Tue, 01 Jun 2021 22:43:54 +020
Message-Id: <693433683...@scdbackup.webframe.org>
)