InformationYou should verify that the TLS CA certificate file (the file that is passed along with the --tlscacert parameter) is individually owned and group owned by root.
The TLS CA certificate file should be protected from any tampering. It is used to authenticate the Docker server based on a given CA certificate. It must be therefore be individually owned and group owned by root to ensure that it cannot be modified by less privileged users.
SolutionYou should execute the following command:
chown root:root <path to TLS CA certificate file>
This sets the individual ownership and group ownership for the TLS CA certificate file to root.
By default, the ownership and group-ownership for TLS CA certificate file is correctly set to root.