Fix Broken Sudo After Chown Disaster | Generated by AI

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Question: I ran sudo chown -R $USER:$(id -gn) $(npm -g config get prefix) and the prefix was /usr/, which changed ownership of many system files (including /usr/bin/sudo), and now sudo says “sudo must be owned by uid 0” and doesn’t work. How can I fix this?

Answer:

Your system is in a very dangerous state right now — many critical system files in /usr/ are probably owned by your normal user instead of root.
The most important file right now is /usr/bin/sudo (or sometimes /bin/sudo or /usr/local/bin/sudo depending on distribution).

Here are the realistic recovery options, ordered from safest → most desperate:

Option 1 – Best chance (if you still have any working root access)

Any method that still gives root (even temporarily):

• Recovery / single-user / rescue mode (most distributions)
  Reboot → hold Shift (GRUB) or Esc (some systemd) → choose Advanced options → Recovery mode → root shell
  or at boot menu select “(recovery mode)” or “Rescue”

  Once you have a root shell:

  # Most important fix first
  chown root:root /usr/bin/sudo
  chmod 4755 /usr/bin/sudo
  
  # Then try to fix the bigger damage (this takes time)
  chown -R root:root /usr/bin /usr/sbin /usr/lib /bin /sbin
  chmod -R u+s /usr/bin/sudo          # just in case
  

• Live USB (very reliable)
  Boot from Ubuntu / Fedora / Mint live USB
  Open terminal → mount your root filesystem:

  sudo mkdir /mnt/root
  sudo mount /dev/sdaX /mnt/root           # replace sdaX with your root partition
  sudo mount --bind /dev   /mnt/root/dev
  sudo mount --bind /proc  /mnt/root/proc
  sudo mount --bind /sys   /mnt/root/sys
  sudo mount --bind /run   /mnt/root/run
  
  sudo chroot /mnt/root
  

  Then inside chroot run:

  chown root:root /usr/bin/sudo
  chmod 4755      /usr/bin/sudo
  exit
  

  After exit → sudo reboot

Option 2 – Quick & dirty (if you only need sudo back and accept risk)

If you have pkexec (PolicyKit) still working (common on Ubuntu/Debian):

pkexec chown root:root /usr/bin/sudo
pkexec chmod 4755 /usr/bin/sudo

or if you have another sudo-like tool still working:

• doas (if installed)
• su - (if you know root password)
• sudoedit / sudo -e sometimes still works even when sudo is broken

Option 3 – Nuclear option (last resort)

If nothing gives root anymore:

1. Boot live USB
2. Mount root partition
3. Copy a known-good sudo binary from the live system:

sudo cp /usr/bin/sudo /mnt/root/usr/bin/sudo
sudo chown root:root /mnt/root/usr/bin/sudo
sudo chmod 4755      /mnt/root/usr/bin/sudo

This often works because live USB sudo is usually the same version.

Summary – fastest realistic recovery path most people use

1. Boot Ubuntu live USB (same version as your system if possible)
2. Mount your broken system
3. chroot into it
4. Fix sudo permissions
5. Reboot and pray the rest of the system still boots

Many people in this situation end up reinstalling the OS because the damage from chown -R on /usr/ is usually too widespread (broken packages, missing libraries, etc.).

Never run chown/chmod -R on any path you get from npm config get prefix unless you are 100% sure what folder it points to.

References:

• None (this is standard Linux permission recovery knowledge)

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