Something went wrong after I run a wrong command about permissions

Ubuntu
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1

I have ran chmod -R +w / on my Edubuntu (a distribution of Ubuntu) laptop. Now I can’t open many apps (Firefox, App Center, etc). I can’t also connect to wifi (I have fixed wifi with the solutions in https:||linuxcommunity.io|t|a-problem-about-web-connection-of-my-linux-computer|10321
topic). I really don’t want to reinstall system. I don’t have USB drive. What should I do?

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@pavlos I’m so appreciate you. I’m so nervous about the problem. Can you help me? Thank you very much :blush:

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I am not an expert but you changed all your permissions under rooot. Here is Chat GPT 5.4 response:

The command chmod -R +w / recursively changes permissions on everything under / (the root directory on Linux/Unix) to add write permission for the “current permission class” implied by +w(i.e., it adds the write bit for *all* users where the+` operator applies in your chmod implementation).

In practice, this makes all files/directories under the entire filesystem writable, which is dangerous and usually not what you want.

  • chmod = change file mode (permissions)
  • -R = recursive (walks directories)
  • +w = add write permission
  • / = the filesystem root (so it affects the whole system)

If you tell me what you’re trying to write (e.g., a specific folder like /var/www/... or /home/user/... ), I can give a safer exact command.

I have no idea how to fix that, but it shows the danger or using commands you don’t understand. Hopefully someone here has an idea for you.

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@Zreamer

you should NEVER run as root on your laptop.

  • simple solution, re-install
  • complicated solution (need skills), build Edubuntu on a VM
find / -exec stat --format "chmod %a %n" {} \;     > /tmp/full_restore.sh

scp /tmp/full_restore.sh user@target-host:/tmp/

execute that .sh file from there and permissions will be reset.

find will collect the permissions of all files.
scp will copy that file to the target host
executing that file will reset permissions.

I repeat, you should NEVER run as root on your laptop.

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How did you install if you don’t have a USB drive?

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I have lost my USB drive :pensive_face:

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Could you borrow a USB drive from a relative or friend if you can’t afford a new one. I know the price of USB drives has increased dramatically as so much memory production is going to AI data centers.

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