Guide: chmod Operation not permitted (Even as Root) in Linux

✨ Quick Answer

Encountering chmod: changing permissions of 'file': Operation not permitted or chown: changing ownership of 'file': Operation not permitted while executing commands as superuser root indicates the file is locked by Linux kernel extended filesystem attributes or the storage partition has degraded to Read-Only mode.

Quick Diagnostics

Cause

File protected by kernel immutable (+i) or append-only (+a) filesystem attribute

Solution

Check with lsattr <file> and clear attributes using sudo chattr -i <file>

Cause

Underlying filesystem mounted in Read-Only (ro) mode following disk I/O errors

Solution

Remount read-write via sudo mount -o remount,rw / or verify SELinux context

Encountering chmod: changing permissions of 'file': Operation not permitted or chown: changing ownership of 'file': Operation not permitted while executing commands as superuser root indicates the file is locked by Linux kernel extended filesystem attributes or the storage partition has degraded to Read-Only mode.

Step-by-Step Solution

1. 1

   Step 1: Inspect Extended Attributes with lsattr

   Standard ls -l commands only expose conventional POSIX permission bits. Extended kernel flags require lsattr:

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   # Inspect extended filesystem attributes
   lsattr /path/to/file
   
   # Typical output showing immutable bit:
   # ----i---------e---- /path/to/file  (Letter 'i' denotes immutable)
   

2. 2

   Step 2: Clear Immutable Flags with chattr

   As superuser, strip the immutable and append-only flags:

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   # Remove immutable (-i) and append-only (-a) flags
   sudo chattr -i /path/to/file
   sudo chattr -a /path/to/file
   
   # Recursively clear across an entire directory tree:
   sudo chattr -R -i /path/to/directory
   

3. 3

   Step 3: Apply Desired Permissions via chmod / chown

   With the kernel lock removed, mutate permissions normally:

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   # Grant standard file read/write permissions
   sudo chmod 644 /path/to/file
   
   # Update ownership
   sudo chown user:group /path/to/file
   

4. 4

   Step 4: Check Filesystem Mount Status

   If lsattr reports no flags yet modification is denied, verify partition write availability:

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   # Inspect root partition mount options
   mount | grep -i " / "
   
   # Remount filesystem read-write
   sudo mount -o remount,rw /
   

❓ Frequently Asked Questions (FAQ)

Does the immutable flag (+i) block root?

Yes. The immutable flag is enforced directly by the Linux kernel VFS layer. No process—even UID 0—can delete or mutate the file until chattr -i is issued.

Does chattr work on FAT32 or NTFS mounts?

No. Extended attributes are exclusive to native Linux filesystems such as ext4, XFS, and Btrfs.