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.

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External hard drive permissions - ext4

I have an external USB 3 disk drive (2TB capacity) that is most likely going to be moved from machine to machine. The disk has a GUID partition table and an ext4 partition. I am unable to write to the ...
3
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1answer
217 views

directory changes permission when mounted

I want to mount a samba sghare to a directory in my home dir. I have created it but mount the share as root. Upon mount, the owner of my dir changes to root and my user doesn't have permission tow ...
3
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1answer
268 views

fail2ban permission denied on script

I've just upgraded from RHEL 5 to 6.5 and setup fail2ban anew. I can't seem to get my custom action to work now, supposedly because of a permission issue. I wan't to know what am I doing wrong, and ...
3
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3answers
270 views

Convert the permissions in `ls -l` output to octal [duplicate]

I want to convert the output of ls to octal permission bits. I think of the shortest and clearest way to implement that excerise: Let's say that we have as input: total 1 drwxr----x 1 user2 workers ...
4
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4answers
925 views

Is making /var/log directory read only on debian linux safe?

I am installing a really small server which got a 512mb CF cars as HD. Not only I haven't plenty of space, but I would like to minimize the writes to disk. I would like to completely clear the ...
6
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1answer
685 views

Why cannot a user change group ownership of his own files? [duplicate]

Why cannot a user change the group permissions of files which he owns. Let's suppose I have user martin: $ ls -lAd /home/martin/ drwx------ 8 martin martin 4096 Apr 20 01:06 /home/martin/ For some ...
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0answers
305 views

Save motion output videos in USB Drive

I'm using a USB drive in my Raspberry to store my website. Now I want also save my videos made with motion. I wasn't able to save in a folder different from /tmp/motion so googling I found I had to ...
3
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2answers
259 views

modify file ownership for files inside tar archive

I am working as user, and I would like to create a tar archive, which when unpacked (by root) will extract its files with root ownership (otherwise root would have to change the ownership manually for ...
2
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0answers
2k views

fatal: bad ownership or modes for chroot directory component “/”

I used to be able to connect via ssh with the user I have created but now I keep getting: "Write Failed: Broken Pipe" and I can only connect as root In the ssh auth.log I get the following: ...
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2answers
164 views

UNIX ACL disadvantages [closed]

I have read a lot about how great UNIX ACLs are. For example, one good example can be viewed here. However, are there any disadvantages or configurations that cannot be expressed using ACL?
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2answers
144 views

mount changes directory permissions to admin:admin?

I'm mounting a samba share from one CentOS server to another using: mount -t cifs -o blarg,password //10.151.170.170/events /var/blarg/copy-to When I do this the permissions of /var/blarg/copy-to ...
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1answer
241 views

Mount image user-readable with udisks2

Loop devices, i.e. for mounting raw disk images, can be managed without root privileges using udisks. For testing purposes, an image can be created and formatted like so: dd if=/dev/urandom ...
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1answer
93 views

What can I do if I got locked out by cphulk?

Is there any way in Linux to create another user with root rights? I got locked out by cphulk and I need some other way to log in. Notice many ways to fix this involve logging in to root or whm. ...
5
votes
1answer
512 views

Writing raw images safely to USB sticks

Trying lots of different linux, on all kinds of hardware I find my self typing commands like this quite often: sudo dd if=xubuntu-13.10-desktop-amd64.iso of=/dev/sdc bs=10240 Needless to say, ...
4
votes
1answer
88 views

Sharing a local directory between local users with full permissions

How do you share a directory /home/shared between two users "eris" and "discordia" such that both can access the directory in their respective home directory, e.g. /home/eris/shared and ...
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2answers
526 views

How to edit /etc/hosts without sudo?

I have a machine that I can only access using SSH. I was messing with the hostnames, and now it says: ssh: unable to resolve hostname I know how to fix it in /etc/hosts. Problem is, I need sudo ...
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1answer
44 views

Mounting a device without read permissions

It is possible mount a flash drive without read permission?
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1answer
2k views

Operation not permitted. For root user?

In order to find a workaround for a problem I had yesterday (see the question here) I come out with another experiment. After inserting a flash drive (vfat) and mounting its only partition I ...
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0answers
2k views

Mounting NFS share from Linux client on Windows domain

I've got a client (Ubuntu 13.10) joined to a Windows domain through PBIS/Likewise, serving Samba shares and allowing domain users to login with domain credentials. Outside of the Windows domain, ...
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2answers
378 views

Can I change devices permissions with chmod?

Before read: I don't want to use any udev rule. I need to change (programmatically) the permissions of some device. But first in order to underestand what I have to do (in code) I want to make the ...
3
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1answer
609 views

While trying to open /dev/mtd2 for read/write access: Permission denied

Looks like my MTD2,and MTD3 partitions are write protected. The OS is booting from SD card on a ARM Cortex A 9 processor. root@Xilinx-ZC702-2013_3:~# mount /dev/mmcblk0p1 /mnt/ ...
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votes
2answers
78 views

Misuse of go-r *

I am working on a test server. Was logged in as root and issued cd / chmod go-r * I certainly revoked the write permissions for the users that I had created. Did I revoke the permissions (r/w/x) ...
9
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1answer
901 views

User permissions inside and outside of LXC containers?

I'm running some services inside of Docker LXC containers on my server and I'm beginning to actually do serious things with them. One thing I'm not clear on is how user permissions work inside and ...
9
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4answers
1k views

Sudoers for one day per week?

I have been volunteered by my boss to be the sysadmin for our production redhat server. He asked me to tighten the security to avoid mishaps like rm -f * that occured not long ago. Right now, we ...
0
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1answer
58 views

Cyrus create mail box gives error permissions denied

On freebsd91 64 bit i installed exim as mta and cyrus as imap server. I use saslpasswd2 root cyradmin -user root localhost localhost> cm INBOX.Sent It gives permissions denied error. In my ...
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1answer
413 views

chmod does not change permissions of certain directories

System file: ext4 I changed the owner of files to apache: with the command: chown -R apache: wp.localhost Then, I could not change the permissions of directories in wp.localhost nor the ...
3
votes
1answer
307 views

What is the relationship between root and kernel? [closed]

Based on part of the first answer of this questions: read from a file (the kernel must check that the permissions allow you to read from said file, and then the kernel carries out the actual ...
2
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1answer
211 views

How can I get write access to my usb drives?

I have trouble writing to external drives. They are monuted automatically in Nautilus, but I can not copy anything there ('Paste' and 'create Folder' are just greyed out). Does Anyone have ideas what ...
10
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3answers
2k views

How Do I check Permissions of Root Folder (/ Folder, not /root)?

Is there a way to check the permissions of the root folder, /? I mean the folder's permissions, not its content's (/var, /usr, etc.) permissions? Running ls /.. shows the content's permissions.
2
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1answer
371 views

Can not change permissions of files/directories in a chrooted filesystem

I am using Ubuntu 12.04 LTS 64 bits to chroot into a just extracted to my harddrive (with unsquashfs) Squash File System from a Kali Linux v1.0.5 32 bits pendrive for customizations: luis@Fujur:$ ...
4
votes
5answers
817 views

logic behind deleting files where user does not have right to write [duplicate]

When I create a file with no write permissions in my home directory: $ umask 777; touch testfile $ ls -ln testfile ---------- 1 1000 1000 0 2014-03-21 16:52 testfile $ ..then I'm still easily able ...
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0answers
131 views

Fixing permissions on a buffalo NAS (XFS via SMB)

I have a Buffalo dual harddrive NAS and plugged one of the drives directly to an SATA port to speed up the file transfer (100 MBit is a 'bit' slow when transfering 2 TB of files). I used a live Ubuntu ...
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0answers
952 views

Reading apache error logs from php

I have apache2 logs at :/var/log/apache2/error.log which has permission: -rw-r----- 1 root adm 127140 Mar 20 12:54 /var/log/apache2/error.log for the sake of accessing from php I changed the ...
3
votes
2answers
53 views

Which directories are writeable in a system following FHS?

I need to ensure that, when deleting a specific user from a system, all of his/her files are removed. User creation/deletion will happen a lot on this system, so I want to reuse UID's and want to ...
1
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1answer
65 views

Not allowed to read a file for some reason

I have these permissions on a file: -rw-r----- 1 root www-data 540 Mar 18 21:12 /etc/phpmyadmin/config-db.php User vagrant is a member of group www-data: vagrant@precise64:~$ cat /etc/group | grep ...
2
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2answers
51 views

Why does the root user have control over mysql directories but not show as a member of the mysql group?

Sorry if this is a duplicate. It seems somewhat similar to the question here but I think what I'm asking is a little different. I've got a CentOS 5.x box running with mysql on it. The root linux ...
5
votes
3answers
3k views

How can I create a udev rule to mount a USB drive read only?

I'm trying to set a particular USB drive to always mount read only. If I plug it in, it is seen as sdb with a single partition, sdb1. Here are some relevant udevadm lines (not the entire output of ...
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0answers
249 views

Netbeans on Linux Mint only starts when run with sudo

I've installed Netbeans directly from the oracle site (the 7.4 Release but also the 8.0 Release Candidate). I really want to install the least possible version, so the one in the apt repos's doesn't ...
6
votes
1answer
101 views

Expected behavior of `find -depth` if execute permission denied for subdirectory?

I'd like to know if I can rely on the behavior I am seeing when using find with -depth option and user does not have execute permission for a subdirectory. Assume the following directory structure: ...
2
votes
1answer
457 views

setfacl default --x on directories and r— on files for user

Having the following directory structure [sr@server directory]$ tree . ├── folder1 │   ├── fileA │   └── fileB └── folder2 └── fileC 2 directories, 3 files I want to set a default facl on ...
2
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2answers
765 views

Permissions with writing NTFS partition from Windows

I mounted my NTFS external hard disk to my Pi this afternoon, my /etc/fstab currently looks like this (I encourage any recommendations or queries made on the properties made, especially the umask - ...
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1answer
140 views

Not allowed to read a file with correct group permissions? ACL?

I just set up a basic nginx server on my Debian 7.0 server. The config file /etc/nginx/nginx.conf is barely modified, and begings with: user www-data; # nginx shall run as user `www-data` I then ...
2
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0answers
388 views

Give domain users permissions on cifs shares?

I am using CentOS 6.5 - users authenticate using winbind, all are domain users except for root. /home is mapped to a cifs share on a windows server in /etc/fstab with this line: \\server\home$ /home ...
2
votes
4answers
2k views

Ownership of etc folder is changed how to restore it using commandline?

I have a computer with Ubuntu 13.10 installed. The user (say Walesa) has changed the ownership of etc folder and all its subfolders from root to Welesa using a privileged file manager. As sudo was ...
0
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1answer
101 views

can not chown a file from my $user to another $user [duplicate]

I am on slackware64 v14.0 and I have file that belongs to me: -rwxrwxr-x+ 1 nass shares 137934 Mar 7 00:06 myfile.csv* I am a member of the "shares" group. The folder that contains myfile ...
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1answer
167 views

How can I prevent some users from deleting files in samba?

I have a sample directory shared out with Samba which all users should have read/write access to. I would like to prevent some of these users from deleting any files (even the ones they create). This ...
5
votes
2answers
479 views

Group memberships and setuid/setgid processes

Processes which de-escalate privileges via setuid() and setgid() do not seem to inherit the group memberships of the uid/gid they set. I have a server process that must be executed as root in order ...
3
votes
2answers
590 views

NFS partition mounted as read only

(Disclaimer: I've read "NFS sharing is read only" and I think it's not the same problem) I have just setup NFS on my raspberry (Raspbian) and I'm trying to access it from OSX. So far so good, I can ...
2
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1answer
108 views

setting default umask and user:group on directory

I have a directory data and I need to set default umask and ownership for all directories/files (both existing and future files). I want all files in data to have ownership root:martin ans ...
2
votes
4answers
1k views

Unable to write to a GPIO pin despite file permissions on /sys/class/gpio/gpio18/value

This is on a Raspberry Pi. Here's the output of sudo ls -lL /sys/class/gpio/gpio18: -rwxrwx--- 1 root gpio 4096 Mar 8 10:50 active_low -rwxrwx--- 1 root gpio 4096 Mar 8 10:52 ...