Public bug reported: When I use ssh-keygen -R to remove a host from known_hosts it changes permissions on the file. This causes problems particularly when used on the global known hosts file (/etc/ssh/ssh_known_hosts), because then only root can read it. Programs running non-interactively as non-root users suddenly fail to SSH and it's not immediately obvious why.
To reproduce: $ ssh-keyscan github.com >test_known_hosts $ chmod 741 test_known_hosts $ ssh-keygen -R github.com -f test_known_hosts $ stat test_known_hosts ... Access: (0600/-rw-------) ... Expected behavior: file permissions remain unchanged (mode 0741 in this example). $ lsb_release -rd Description: Ubuntu 18.04.6 LTS Release: 18.04 $ apt-cache policy openssh-client openssh-client: Installed: 1:7.6p1-4ubuntu0.6 ** Affects: openssh (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to openssh in Ubuntu. https://bugs.launchpad.net/bugs/1966591 Title: ssh-keygen -R changes known_hosts file permissions (mode) Status in openssh package in Ubuntu: New Bug description: When I use ssh-keygen -R to remove a host from known_hosts it changes permissions on the file. This causes problems particularly when used on the global known hosts file (/etc/ssh/ssh_known_hosts), because then only root can read it. Programs running non-interactively as non- root users suddenly fail to SSH and it's not immediately obvious why. To reproduce: $ ssh-keyscan github.com >test_known_hosts $ chmod 741 test_known_hosts $ ssh-keygen -R github.com -f test_known_hosts $ stat test_known_hosts ... Access: (0600/-rw-------) ... Expected behavior: file permissions remain unchanged (mode 0741 in this example). $ lsb_release -rd Description: Ubuntu 18.04.6 LTS Release: 18.04 $ apt-cache policy openssh-client openssh-client: Installed: 1:7.6p1-4ubuntu0.6 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1966591/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp