Linux Server / Networking, SSH & Web Services
Check path traversal and ownership during SSH public-key rejection
A valid public key can be ignored when ownership or permissions along the account's path violate the server's access rules.
Environment and inputs: Linux server baseline · Ubuntu 24.04 LTS / RHEL 9-style systems. Use the specified distribution, init system and installed tool; service names, privileges and supported options can differ.
Start with this check
Confirm the host, shell and access role. Replace sample names, paths, domains and interfaces with approved targets. These are diagnostic commands; assess policy and workload impact before making changes.
namei -l /home/app/.ssh/authorized_keysRead the result
On Linux with util-linux tools, this shows ownership and permissions for each path component. It does not print the key file or evaluate all sshd policy.
Resolve and verify
Compare the intended account home, AuthorizedKeysFile setting and authentication logs. Correct the smallest verified permission or path issue and test a new authorized session.
Before changing production
Do not make .ssh files world-writable or replace the account's keys without an identity-verified request.