8.5. Changing Ownership



This step is not optional as some of the binaries in /tools are set u+s. leaving the permissions as is could cause some commands, mount in particular, to fail later.

Currently, the /tools and /cross-tools directories are owned by the user clfs, a user that exists only on the host system. Although the /tools and /cross-tools directories can be deleted once the CLFS system has been finished, they can be retained to build additional CLFS systems. If the /tools and /cross-tools directories are kept as is, the files are owned by a user ID without a corresponding account. This is dangerous because a user account created later could get this same user ID and would own the /tools directory and all the files therein, thus exposing these files to possible malicious manipulation.

To avoid this issue, add the clfs user to the new CLFS system later when creating the /etc/passwd file, taking care to assign it the same user and group IDs as on the host system. Alternatively, assign the contents of the /tools and /cross-tools directories to user root by running the following commands:

chown -Rv 0:0 /tools
chown -Rv 0:0 /cross-tools

The commands use 0:0 instead of root:root, because chown is unable to resolve the name “root” until the passwd file has been created.