I was a happy guy until when, accidentally, I did this command in my Mac Os X (Yosemite 10.10.5) a few moments a go:
$ sudo chown -R my.user:staff usr/
Then, terribly, when I try to use sudo a horrible error occurs:
$ sudo su -
sudo: effective uid is not 0, is sudo installed setuid root?
Any one have any idea about how to solve these and save my life, please?
Obs: I can't open new terminals but I still have two terminals opened, one logged with my.user and other with root.
Maybe if you changed the owner to actually used by you user, you can change without sudo the ownership to root by chown -R root:root /usr?
I found this tutorial and it saved me from ruin:
Open Disk Utility, which is in the Utilities folder of your Applications folder.
Select the startup disk from the list of volumes.
Click the First Aid tab.
To check permissions, click Verify Disk Permissions. To repair permissions, click Repair Disk Permissions.
https://support.apple.com/en-us/HT201560
Related
I have a normal Linux user say user1 , and it has sudo access to a command /usr/local/bin/command.sh .
/usr/local/bin/command.sh has 700 permission. So therefore the user1 is successfully able to run
sudo /usr/local/bin/command.sh
Now I was wondering that with sudo command the privilege escalation is happening. is there any possibility or even a remote possibility that he can read the contents of /usr/local/bin/command.sh ? Is sudo by design a very strict command based implementation?
The one word answer is: No.
(…) So therefore the user1 is successfully able to run (…)
Strictly speaking it is not user1 who is running that executable, but the user switched to using sudo (in your case root), who of course can also read that file. Now if there's a vulnerability in the executable executable run via sudo, you could piggyback on that to read an arbitrary. file, but that would be bad.
I am a trainee programmer and I have sometimes my head in the clouds..
My collegues were messing with my professional computer with ssh connections. One of them told me that the best way to prevent it was to secure my computer. In order to do this, I accidentally change the permissions on the /usr directory.
What I did just for testing was :
sudo chmod 644 /usr
Now I can't use my computer anymore! I can't change the permission back since I am not sudo anymore. On my desktop all my applications shutdown.
Is there a way to revert a chmod 644 on /usr?
There is some important work related stuff on this computer and my internship will probably be terminated if I can't recover the access to important files.
Please help !!
This command need a Sudoers password:
sudo chmod 644 /usr
So either you have a sudo password and can change the right to this file with:
sudo chmod 755 /usr
Or you friends messed with you...
You can do it by:
adding your self to sudoers on boot...
https://askubuntu.com/questions/70442/how-do-i-add-myself-back-as-a-sudo-user
I'm creating an install script for a Linux game. As part of the installation, I change the suid permissions of the game executable to the "games" group so that the game can update the highscore file even when its run by regular users.
Right now my Makefile.am looks like this:
AUTOMAKE_OPTIONS = foreign
SUBDIRS = src man
install-exec-hook:
chgrp games #bindir#/xjump
chmod +s #bindir#/xjump
mkdir -p #localstatedir#/xjump
touch #localstatedir#/xjump/record
chmod 660 #localstatedir#/xjump/record
chgrp games #localstatedir#/xjump/record
The problem I am having is that the chgrp command requires administrative privileges. If I am installing the game globally using sudo make install then its all works fine but if I change the prefix to somewhere in my home directory and try to do a regular make install it fails due to the chgrp
chgrp: changing group of ‘/home/hugo/Desktop/aaa/bin/xjump’: Operation not permitted
Since the locally installed version of the game only has a single player, I don't really need to do the chgrp thing. Is there a way to detect if the makefile is being run without root privileges and skip the permission changing? Or should I add a configuration flag to my configure script instead of trying to fix this permission issue automatically?
When the commands fail, you did not run as root. It seems nothing goes wrong, you just do not want the error messages.
You can see who you are, but the easiest solution is redirecting the output
Finish with true, so your step doesn't fail:
chgrp games #localstatedir#/xjump/record 2>/dev/null || true
If you run "whoami", you would be able to find out who the current user is.
runner=`whoami` ;
if test $$runner == "root" ;
then
chgrp games #localstatedir#/xjump/record
fi
I recently installed LAMP on my Ubuntu 14.04 laptop. But I didn't have full/root access to the files var/www and etc/apache2/sites-enabled/000-default.conf so I did some research to change permissions and admissions to the directory, using this command in the terminal:
sudo chown -R username:group directory
It worked perfectly. But now I can't do any sudo commands in the terminal. I wanted to restart the apache server but here is what it showed me:
sudo: /etc/sudoers is owned by uid 1000, should be 0
sudo: no valid sudoers sources found, quitting
sudo: impossible d'initialiser le greffon de règles
(my computer is in french btw).
What I want to know is how to set it back to sudo. I hope I explained myself good enough. If you need additional info that I didn't state please tell me. I will add it. Thnx.
Seems like you chown'd /etc/sudoers.
Try:
sudo chown root:root /etc/sudoers
Then if you want read/write privileges, see which group the folder /var/www belongs to (probably www-data)
To add yourself to the www-data group, try:
sudo useradd -a -G www-data yourUserName
Also, as a side note; be careful of recursive commands!!! If you're not sure what a command does, test it on a single file before making it recursive. For example:
DO NOT RUN THIS CODE, I DON'T INCLUDE SUDO ON PURPOSE SO YOU DONT HOSE EVERYTHING
rm -r /
Will delete everything inside / (a lot of stuff!)
I have problem with accessing the shared folder.
My host OS is Windows 7 Enterprise Edition SP1, and the guest OS is Ubuntu Linux 10.04 Desktop Version. I'm using Virtual Box 4.2.10, and I have installed VBox guest add-on and Oracle VM VirtualBox Extension Pack.
When I put commend:
mat#mat-desktop:~$ cd /media/sf_MAT/
bash: cd: /media/sf_MAT/: Permission denied
again with sudo:
sudo cd /media/sf_MAT/
sudo: cd: command not found
What could be the solution?
The issue is that your user "mat" is not in the same group as "vboxsf". This group "vboxsf" is the group which has read/write permissions to that folder. Also the root has permission to that folder because its in the group "vboxsf".
What you need is to add your user "mat" to the same group. Start your terminal and write the following line:
sudo usermod -aG vboxsf mat
sudo - because you need root permission
usermod - the command to change the user properties
-a means append to the group
-G means you will supply the group name now
vboxsf is the group name that you want your user to be in
mat is your username
A reboot, or a logout, may be required for changes to take affect.
After this operation you can verify that your user is indeed in the vboxsf group by doing this:
cat /etc/group | grep "vboxsf"
you will see your username there.
Now you shall be able to access that folder. If any issue, just comment here and I will tell you alternative methods.
Also, if all of this sounds too geeky, you can do the same thing using the graphical tools. One guide is here http://www.howtogeek.com/75705/access-shared-folders-in-a-virtualbox-ubuntu-11.04-virtual-machine/
Also, in new virtual box - 4.3.20 I guess, they have this new feature of drag and drop where you can just drag files and folders to your virtual machine just by dragging. Isn't that nice. :)
Open your Virtual Machine's Terminal. Type sudo su then enter your password.
Write the following commands
sudo usermod -a -G vboxsf your_account_name
sudo chown -R your_account_name:users /media/your_share_folder_name/
Example sudo usermod -a -G vboxsf mat
Example sudo chown -R mat:users /media/sf_MAT/
Now reboot your Virtual Machine and check the shared folder again
I have this problem to. The problem seems to be with your user account not having permission to use the folders. The only solution I have is to enter root using the su command. You can then read, write, and navigate freely. You might have to set a root password first using sudo passwd root.
Reason : sudo cd will not work as sudo works on program and not command. cd is an inbuilt command.
Soluiton: try sudo -i ..this will elevate you to super user.
Now you will be logged in as root and use any command you wish
eg.
sudo -i
cd folder/path
use exit to return back to normal user.
You only need to follow these steps:
in the terminal execute:
sudo adduser yourUserName vboxsf
enter your root password, expect the following message:
Adding user `yourUserName' to group `vboxsf' ...
Adding user yourUserName group vboxsf
Done.
Log out and back in.
You now can access your shared folders (with the limitations you set for them via VirtualBox)
For all other just add new optical drive in storage(Via setting) and add ISO manually(It is inside installed directory) in Host OS. Now click on mounted drive and install in Guest OS.
Reboot enjoy