ssh returns "Bad owner or permissions on ~/.ssh/config"

When I try to ssh to another box, I get this strange error

$ ssh hostname
Bad owner or permissions on ~/.ssh/config

But I made sure that I own and have rw permissions on the file:

ls -la ~/.ssh/
total 40K
drwx------ 2 robert robert 4.0K Mar 29 11:04 ./
drwx------ 7 robert robert 4.0K Mar 29 11:04 ../
-rw-r--r-- 1 robert robert 2.0K Mar 17 20:47 authorized_keys
-rw-rw-r-- 1 robert robert   31 Mar 29 11:04 config
-rw------- 1 robert robert 1.7K Aug  4  2010 id_rsa
-rw-r--r-- 1 robert robert  406 Aug  4  2010 id_rsa.pub
-rw-r--r-- 1 robert robert 6.1K Mar 29 11:03 known_hosts

I needed to have rw for user only permissions on config. This fixed it.

chmod 600 ~/.ssh/config

As others have noted below, it could be the file owner. (upvote them!)

chown $USER ~/.ssh/config

If your whole folder has invalid permissions here's a table of possible permissions:

Sources:

• openssh check-perm.c
• openssh readconf.c
• openssh ssh_user_config fix_authorized_keys_perms

These commands should fix the permission problem:

chown $USER ~/.ssh/config
chmod 644 ~/.ssh/config

Prefix with sudo if the files are owned by different user (or you don't have access to them).

If more files are affected, replace config with *.

In man ssh we can read:

Because of the potential for abuse, this file must have strict permissions: read/write for the user, and not writable by others. It may be group-writable provided that the group in question contains only the user.