What prevents `nobody` user from listing a directory that it owns?

foki

7/21/23, 8:43 PM

This is all in an LXC container and I'm logged in as nobody user.

$ whoami
nobody
$ ls /share
ls: cannot open directory '/share': Permission denied
$ ls -lha / | grep share
drwxrws---    9 nobody       4000  183 Mar 21 18:30 share

Now, it appears that the nobody user cannot list a directory it owns.

This /share is mounted from a NAS:

$ mount -l | grep share
a_nas:/share/a_nas/my_storage on /share type nfs (rw,nosuid,nodev,noatime,nodiratime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=SOME.IP,mountvers=3,mountport=20048,mountproto=udp,local_lock=none,addr=SOME.IP)

Importantly, I have no access to the NAS server.

0 + 0

linux

permissions

linux-networking

Tomek

7/21/23, 9:15 PM

What are the export options on the server? Is kerberos authentication used on this export? (this is unlikely) Are there any ip address restrictions on the nfs share? Is the user and group id for `nobody` user the same on both client and server? Is there a firewall which allows mountd but blocks nfs?

foki

7/21/23, 9:19 PM

@Tomek Unfortunately, I have no access to the NAS server. I've updated my question.

Tomek

7/21/23, 9:21 PM

`showmount -e <a_nas>` may be of some help here (usually it shows ip/netgroup restrictions). Can you cd to this directory?

Tomek

7/21/23, 9:23 PM

And can you possibly check if it works outside container?

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: What prevents `nobody` user from listing a directory that it owns?

TH: อะไรป้องกันไม่ให้ผู้ใช้ 'ไม่มีใคร' แสดงรายการไดเร็กทอรีที่เป็นเจ้าของ

RO: Ce împiedică utilizatorul „nimeni” să listeze un director pe care îl deține?

RU: Что мешает пользователю «никто» указать каталог, которым он владеет?

VI: Điều gì ngăn cản người dùng `nobody` liệt kê một thư mục mà nó sở hữu?

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