Questions tagged [permissions]
Permissions are the Unix way of controlling access to resources such as files, directories and devices and may be specified for an owner, group, or all users.
4,597 questions
0 votes
1 answer
38 views
Give run0 privileges to user1 (an admin) as root?
I am very paranoid about security, trying to push the limits. I am curious about nosuid because I think it is very cool that we can prevent files from executing with elevated permissions by setting it ...
- 1
10 votes
1 answer
779 views
Why could a perfectly accessible file fail to be opened due to EACCES?
I made a custom ~/.asoundrc on Ubuntu 24.04, but when I run alsamixer I get an error: ALSA lib conf.c:4123:(config_file_open) cannot access file /home/ruslan/.asoundrc ALSA lib conf.c:4043:(...
- 3,670
0 votes
2 answers
81 views
What is /usr/sbin/authserver and the binary inside
When using the find command or any other recursive file searches, I always notice /usr/sbin/authserver in the context of a "permission denied" error. Just out of pure curiosity, what ...
3 votes
3 answers
216 views
unison permissions between machines
I have two linux computers: personal (arch, full root access) workplace (ubuntu, no root access). I am using "Unison" to sync some selected directories from one computer to an ext4 USB ...
- 31
0 votes
0 answers
53 views
Why does `chmod 640` prevent group read access on macos?
I'm a student learning UNIX permissions and scripting on macOS. I created a short script that makes a file and applies chmod 640. However, a user in the same group cannot read the file. Here is the ...
- 1
1 vote
0 answers
93 views
How to fix selinux error: avc: denied { write } because the source level (s0:c145,c256,c512,c768) and target level (s0) are different
My Android app is trying to write to the /dev/video0 file but is getting the following AVC denial: 10-31 08:31:42.987 4786 4786 W com.my.app: type=1400 audit(0.0:41): avc: denied { write } for name=&...
1 vote
1 answer
54 views
Permission denied with crontab -e program
I would like to run a custom script on startup. I added the script to my root crontab via sudo crontab -e and adding @reboot /path/to/my_custom_script.sh to the end. I made sure my_custom_script.sh ...
- 13
1 vote
1 answer
125 views
where is my umask value set?
I'm explicitly setting umask to the same value (0077) in two locations: ~/.profile & in /etc/systemd/system/[email protected]/umask.conf per this comment: [Service] UMask=0077 Yet in my shell ...
- 814
0 votes
2 answers
63 views
Unbind/re-bind usb device via systemctl service running as user (with a custom group)
Basically, without giving the user any new permissions, I am looking to be able to write to /sys/bus/usb/drivers/usb/unbind and /sys/bus/usb/drivers/usb/bind via a systemd service running as the ...
0 votes
0 answers
24 views
Unable to save program data that uses root authentication dialog
I'm running Gnome 48 using Ubuntu on TUXEDO Pulse 14 laptop. I have a program(Tuxedo Control Centre)that requires the root password to save any settings. The program works fine on another distro. When ...
3 votes
2 answers
512 views
Scheduling file permission changes
I'm new with Linux and I worked on permissions recently. I'd like to find out if it is possible to schedule permission changes and how can it be done? I mean if I want to give say a group, access to ...
3 votes
2 answers
396 views
Correct permissions for a LUKS key file
journalctl -b shows: systemd-cryptsetup[1807]: Key file /some-path/keys/sda1.luks is world-readable. This is not a good idea! … systemd-cryptsetup[1807]: /some-path/keys/sda1.luks has 0644 mode that ...
- 410
0 votes
0 answers
45 views
User can't execute a shell script based on shebang but ok when interpreter directly invoked [duplicate]
Context I have a system user caddy and a shell script placed under /run/caddy/caddy-cert-obtained-wrapper.sh. /run and /run/caddy are owned by root:root with permissions 0755. caddy-cert-obtained-...
5 votes
2 answers
748 views
Permission denied using pv for copying image to USB drive
I am attempting to copy an Arch Linux ISO image directly to a USB drive. Previously, I have simply used either cp or dd to do this, such as: sudo cp image.iso /dev/sdb where /dev/sdb is the USB ...
- 153
1 vote
1 answer
59 views
Killing a process with ruser root and euser user
I'm learning linux permissions and confused about the permissions for killing a process. First, from kill(2) manpage: For a process to have permission to send a signal it must either be privileged (...
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