On Fri, Apr 11, 2025 at 14:41:04 +0200, Hans wrote: > Without any checks, my first thing would be, to check in both computers if > any > of the executables related to cups might have different rights settings. > > Especially the executable, which creates the file in /tmp. A file which is > created mostly gets the ownership and posessions of the creatorbinary (father- > child-principle).
Not exactly. A file inherits ownership from the effective UID under which the process is running, which is usually not the same as the owner of the process's on-disk executable file(s). Usually the file will be owned by root, but the effective UID of the running process will be set by the init configuration file (systemd unit or sysv-rc script). However, if an executable file has the setuid or setgid permission bit(s) set, then the effective UID and/or GID of the process will be set to match the file's owner and/or group. So, to add to the list of things that you can check: * Broken permissions (added or missing setuid or setgid) on any of the CUPS binaries. * Invalid UID or GID of a named system account under which any of these programs is executed, or a missing system account entry. * Broken systemd or sysv-rc init files. And, as I mentioned before: * Broken permissions on the /tmp directory (after mounting, if it's a separate file system). * Invalid file system type or mount options on the /tmp file system, if it's a separate file system.
