Q: A user complains they cannot execute a script (`./script.sh`), getting a "Permission denied" error. They own the file and have `rwx` permissions. What else could cause this?

Even if the file has chmod +x and the user owns it, execution can be blocked by:

• Mount options: The filesystem where the script resides might be mounted with the noexec flag (often used for /tmp or /var/tmp for security). You can check this by running mount | grep noexec.
• Interpreter path: The script's shebang (#!/bin/bash) might point to a missing interpreter, or the interpreter itself lacks execute permissions.
• SELinux/AppArmor: Mandatory Access Control policies might block the execution. Checking dmesg or /var/log/audit/audit.log will reveal SELinux denials.

• Improper ACLs: Extended ACLs (checked via getfacl script.sh) might have a deny rule superseding standard POSIX permissions.